GRINDING MACHINE

Abstract

A grinding machine enabling the easy maintenance and inspections of mechanisms arranged therein, an increase in visibility when the states of a workpiece and a grinding wheel are confirmed, and the easy loading/unloading of the workpiece and the easy replacement of the grinding wheel. The grinding machine comprises a workpiece supporting/driving device, a wheel work head, a wheel head feeder, a coolant supply unit, a cover covering internal devices such as the workpiece supporting/driving device, the wheel work head, the wheel head feeder, and the coolant supply unit, and an open/close door formed at a part of the working space side upper surface of the cover and allowing at least the loading/unloading of the workpiece and the replacement of the grinding wheel.

Description

TECHNICAL FIELD

This invention relates to a grinding machine to grind a workpiece by using a rotating grinding wheel and, in particular, to a grinding machine that allows easy maintenance and inspection of mechanisms arranged therein, enhancement in visibility required when confirming the state of a workpiece and a grinding wheel, easy loading/unloading of the workpiece, and easy replacement of the grinding wheel.

BACKGROUND ART

Conventionally, a grinding machine is known in which a grinding wheel head supporting a grinding wheel to be rotatably driven is mounted over a bed through a sliding mechanism to be movable toward a work head and a foot stock, and which is operable to grind, by using the grinding wheel, a workpiece supported between the work head and the foot stock to be rotatably driven while supplying a coolant over the workpiece from a coolant nozzle (e.g., Patent Literatures 1 and 2). Some of the grinding machines have a cover for preventing dispersal of a coolant, a grinding dust etc. and for protecting the machine from external dust etc.

Patent Literature 1 discloses a grinding machine that has a whole cover which covers the whole of the work head, the foot stock, the grinding wheel head and the sliding mechanism of the grinding wheel head, a sliding door is formed in the middle portion of the front face of the bed to open/close in loading/unloading of the workpiece, and double doors are formed on both sides of the whole cover to allow the maintenance and inspection of devices such as the sliding mechanism of the grinding wheel head.

Patent Literature 2 discloses a grinding machine that allows the replacement of a workpiece through a workpiece loading/unloading port by using a workpiece loading/unloading device when a protective cover is open.

Patent Literature 1: JP-2003-117828 (page 4—right column, page 5—right column to page 6—left column, FIG. 1, and FIG. 7)

Patent Literature 2: JP-2002-103216 (page 3—left column, FIG. 1, and FIG. 2)

DISCLOSURE OF INVENTION

Problems To Be Solved By The Invention

However, the conventional grinding machine in Patent Literatures 1 and 2 has problems that ergonomic data are not considered in design regarding to workability in loading/unloading a workpiece, in replacing a grinding wheel or in maintaining and inspecting mechanisms arranged therein, or to visibility in confirming the state of the workpiece and the grinding wheel. In particular, relationships between working efficiency etc. and the rotation center position of the workpiece, the position of the grinding wheel spindle, the height of the upper surface of the machine, the diameter of the grinding wheel, the material of the wheel, the dimensions and shape of the opening portion of the cover, the dimensions and shape of the open/close door formed on the cover and the like are not sufficiently considered. Therefore, in the conventional grinding machine, the loading/unloading of the workpiece, the replacement of the grinding wheel or the maintenance and inspection of mechanisms arranged therein are conducted by opening a door formed on the side surface of the whole cover, and the loading/unloading of the workpiece or the replacement of the workpiece is needed to conduct by using a workpiece loading/unloading device through a workpiece loading/unloading port. Thus, the working efficiency is low and, in particular, it is difficult for a worker to load/unload of the workpiece or to replace the grinding wheel without using a working step.

Therefore, it is an object of the invention to provide a grinding machine that allows easy maintenance and inspection thereof, enhancement invisibility required when confirming the state of the workpiece and the grinding wheel, easy loading/unloading of the workpiece and easy replacement of the grinding wheel. In particular, the invention provides a grinding machine with a structure considered to allow the worker to naturally take a posture based on ergonomic data.

Means For Solving The Problems

In order to achieve the object described above, the first invention provides a grinding machine comprising: a workpiece supporting/driving device anteriorly mounted on a bed, and supporting a workpiece to be rotatably driven; a grinding wheel head comprising a bearing portion supporting a wheel spindle to be rotatably driven on which a grinding wheel is mounted, and a base mounted over the bed to be relatively movable to the workpiece through a grinding wheel head sliding mechanism; a grinding wheel head feeder moving the grinding wheel head forward or backward to the workpiece supporting/driving device; a coolant supply unit supplying a coolant to a working area in which the grinding wheel grinding processing the workpiece; a cover covering internal devices such as the workpiece supporting/driving device, the grinding wheel head, the grinding wheel head feeder, the coolant supply unit; and an open/close door formed on a part of an upper surface in working space side of the cover, being capable of at least loading/unloading of the workpiece and replacing the grinding wheel.

In the invention described above, the cover can comprise an upward open/close door or a sliding open/close door at least a part of the upper surface.

Further, in the invention described above, the open/close door can be formed on the upward open/close door or the sliding open/close door.

Further, in the invention described above, the open/close door can comprise large size enough for a part of the workpiece to be visible in the workpiece supporting direction, and the open/close door can comprise large size as a length in a sliding direction of the grinding wheel head enough for a part of the grinding wheel to be visible from the open/close door in the sliding direction of the grinding wheel head at the stop of the grinding work.

Further, in the invention described above, the open/close door can comprise the size larger than the maximum length of the workpiece in the workpiece supporting direction and larger than the maximum diameter of the grinding wheel head in the sliding direction.

Further, in the invention described above, the workpiece can comprise a rotation center position at not less than 200 mm and not more than 400 mm from the front face of machine, and comprise a rotation center position at not less than 850 mm and not more than 1000 mm from the floor face.

Further, in the invention described above, the wheel spindle can comprise a center position thereof at not less than 250 mm and not more than 500 mm from the front face of machine, and at not less than 850 mm and not more than 1000 mm from the floor face.

Further, in the invention described above, the grinding machine can comprise a height of not less than 900 mm and not more than 1100 mm from the floor face.

Further, in the invention described above, the grinding wheel can comprise an outer diameter of not less than 100 mm and not more than 200 mm, and comprise CBN grinding wheel having aluminum or titanium disk as a core.

Further, in the invention described above, the open/close door can be formed within a region of not less than 200 mm and not more than 700 mm from the front face of machine, and not less than 1000 mm and not more than 1200 mm from a floor face.

Furthermore, in the invention described above, the open/close door can be formed on a region in which the workpiece or the grinding wheel head is replaceable in an open condition.

In order to achieve the object described above, the second invention provides a grinding machine comprising: a workpiece supporting/driving device anteriorly mounted on a bed, and supporting a workpiece to be rotatably driven; a grinding wheel head comprising a bearing portion supporting a wheel spindle to be rotatably driven on which a grinding wheel is mounted, and a base mounted over the bed to be relatively movable to the workpiece through a grinding wheel head sliding mechanism; a grinding wheel head feeder moving the grinding wheel head forward or backward to the workpiece supporting/driving device; a coolant supply unit supplying a coolant to a working area in which the grinding wheel grinding processing the workpiece; and a cover covering internal devices such as the workpiece supporting/driving device, the grinding wheel head, the grinding wheel head feeder, the coolant supply unit, and formed below a height of an arm turning portion just proximal to a handling portion of a working robot performing a lift up/down operation, so that a loading/unloading the internal portion of the workpiece and a replacement of the grinding wheel can be conducted from a working space in a front face, centering around the lift up/down operation.

Furthermore, in the invention described above, the cover can comprise an open/close door within a region in which the lift up/down operation can be performed.

Furthermore, in the invention described above, the loading/unloading of the workpiece, the replacement of the grinding wheel, and the lift up/down operation can be conducted by the robot.

Furthermore, in the invention described above, the cover can be formed below the height of the turning portion of the robot.

In order to achieve the object described above, the third invention provides a grinding machine comprising: a workpiece supporting portion supporting a workpiece to be processed on a first rotating shaft; a grinding wheel supporting portion supporting a grinding wheel to process the workpiece on a second rotating shaft; a side cover enclosing the workpiece supporting portion and the grinding wheel supporting portion from the side; a upper cover enclosing a first opening portion formed on the upper side by the side cover; and an open/close member formed on a working space side of the upper cover, to open/close a second opening portion for a loading/unloading of the workpiece, and a replacement of the grinding wheel; and the second opening portion is formed on the upper cover, so that a straight line perpendicular to the first and second turning shafts in a center position thereof comprises a certain inclined angle to a floor face.

Furthermore, in the invention described above, the second opening portion can be formed on the upper cover, so as to comprise an inclined angle of 45 degrees to 75 degrees as the certain inclined angle.

Advantages of the Invention

According to the invention, the opening portion is formed on the cover so that the loading/unloading of the workpiece and the replacement of the grinding wheel can be performed through at least an upper or front surface of the machine to facilitate the grinding work etc. This can enhance easy maintenance and inspection of the mechanisms arranged therein, visibility required when confirming the state of the workpiece and the grinding wheel, easy loading/unloading of the workpiece and easy replacement of the grinding wheel. Generally, it is usual that workers are each working in different postures even if they have knowledge about the ergonomic data. However, in the invention, since the opening portion of the cover is formed at a position determined by considering the ergonomic data, the workers can work naturally in posture based on the ergonomic data.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view showing a cylindrical grinding machine in a first preferred embodiment according to the invention,

FIG. 2 is a plan view showing the cylindrical grinding machine shown in FIG. 1 as an overhead view when an upper open/close cover is dismounted,

FIG. 3 is a plan view showing the grinding machine shown in FIG. 1 as an overhead view,

FIGS. 4A to 4E are schematic views showing the position and dimensions of each part in the first preferred embodiment,

FIG. 5 is a side view showing a cylindrical grinding machine in a second preferred embodiment according to the invention,

FIG. 6A is a schematic view showing a cylindrical grinding machine in a third preferred embodiment when an upper open/close door is closed,

FIG. 6B is a schematic view showing a cylindrical grinding machine in the third preferred embodiment when the upper open/close door is opened,

FIG. 7A is a schematic view showing a cylindrical grinding machine in a fourth preferred embodiment when an open/close door of sliding type is closed,

FIG. 7B is a schematic view showing a cylindrical grinding machine in the fourth preferred embodiment when the open/close door of sliding type is opened,

FIG. 8 is a side view showing a fifth preferred embodiment,

FIG. 9 is an explanatory view showing how an operating force of arm changes dependent on the directions, and

FIG. 10 is an explanatory view showing a front horizontal plane area to facilitate a working which is conducted near a height of body section.

EXPLANATION OF REFERENCE NUMERALS

• 10 cylindrical grinding machine
• 11 grinding machine body
• 12 bed
• 13 coolant chute
• 24, 26 left and right work head
• 27, 32 linear motor
• 30 grinding wheel head
• 33 slide
• 31, 35 linear guide
• 37 bearing portion
• 45 side enclosing cover
• 47 coolant supply nozzle
• 50 attachment device
• 51 coolant supply unit
• 52 open port
• 53 upper open/close cover
• 53s slide open/close cover
• 54 bracket
• 55 hinge
• 57, 57u, 57s open/close door
• 570 hinge
• 58 slide rail
• 59 gas cylinder
• 61 working area
• 62 sliding area
• 63 frame body
• 64a, 64b left and right accordion cover
• 65 passing hole accordion cover
• 66 separating cover
• 69 lever mechanism
• 73 rodless cylinder
• 100 handling robot
• 101 robot body
• 102 first arm turning portion
• 103 first arm
• 104 second arm turning portion
• 105 second arm
• 106 handling portion
• G grinding wheel
• Wh grinding wheel disk
• W workpiece
• B floor face
• P worker

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment

A grinding machine in a first preferred embodiment according to the invention will be explained below referring to the attached drawings.

FIG. 1 is a side view showing a cylindrical grinding machine in the first preferred embodiment, and FIG. 2 is a plan view showing the cylindrical grinding machine shown in FIG. 1 as an overhead view when an upper open/close cover is dismounted. The cylindrical grinding machine 10 comprises a grinding machine body 11 and an attachment device 50. In the FIGS. 1, 2 the attachment device 50 comprises a coolant supply unit 51, a mist collector 60, and a duct device 70 connecting the devices 51, 60 to the grinding machine body 11. The grinding machine body 11 comprises a bed 12, and the bed 12 mounts a workpiece supporting driving device 20 on an upper surface of the front portion in left side of FIG. 1 and a grinding wheel head 30 on an upper surface of the rear portion in right side of FIG. 1. The workpiece supporting driving device 20 comprises a left work head 24 and a right work head 26 which are respectively mounted and fixed on side surfaces of supports 22 mounted uprightly from the a work table 21 fixed on the bed 12, so as to be position-adjustable in up/down direction in FIG. 2 along with a pair of liner guides 25. A workpiece is supported between centers of the left and right work heads 24, 26 rotatably around a horizontal axis line, and the workpiece can rotate by a spindle motor (not shown) at a workpiece rotation center position departing from a front surface of the machine and a floor surface by a certain distance.

On the other hand, a pair of linear guides 31 extending in a Z-axis direction parallel to a horizontal axis line of the workpiece is fixed on an upper surface of a rear portion of the bed 12. The linear guide 31 guides a slide 33, and the slide 33 is moved by a Z-axis linear motor 32. A pair of linear guides 35 extending in a X-axis direction perpendicular to the Z-axis is fixed on an upper surface of the slide 33, and a base 34 of the grinding wheel head 30 is guided and supported on the linear guides 35 so as to move forward or backward to the workpiece W by a X-axis linear motor 27. The linear guides 31, 35, the slide 33, and the linear motors 27, 32 constitute a slide mechanism of the grinding wheel head 30 and a grinding wheel head feeder.

A bearing portion 37 is mounted on a front portion of the grinding wheel head 30, and a grinding wheel shaft 38 of the grinding wheel G having a disk as a core is supported on the bearing portion 37 rotatably at a certain position from the front surface of the machine and the floor surface B. A pulley 39 fixed to the grinding wheel shaft 38 is connected to a pulley 41 fixed to an output shaft of a driving motor 40 through a belt 42 to rotate simultaneously, so that rotation power of the driving motor 40 can be transmitted to the grinding wheel shaft 38 and the grinding wheel G. A coolant supply nozzle 47 is mounted on the bearing portion 37, so as to discharge the coolant supplied from a pipe line 47a installed in the grinding wheel head 30 toward a neighborhood of grinding point which is a contact point of the workpiece W and the grinding wheel G.

Further, the grinding machine body 11 comprises the side enclosing cover 45 covering and enclosing the workpiece supporting driving device 20 and the grinding wheel head 30 disposed on the bed 12, and a circumference of the slide mechanism. The side enclosing cover 45 is bent inside in the lower end portion thereof, and is fixed to a circumferential edge of the bed 12 by bolting. Further, the side enclosing cover 45 is formed to be higher than the workpiece supporting driving device 20 and the grinding wheel head 30, so as to enclose the side portions of the workpiece supporting driving device 20 and the grinding wheel head 30.

Furthermore, the inside of the side enclosing cover 45 is separated into a working area 61 where the workpiece supporting driving device 20, the grinding wheel G, and the bearing portion 37 of the grinding wheel head 30 are located, and a sliding area 62 where the base 34 of the grinding wheel head 30, the driving motor 40, the linear guides 31, 35, and the slide 33 etc. are located, and in an anteroposterior direction by a separating cover 66. That is, a frame body 63 of rectangular shape comprising a passing hole through which the bearing portion 37 passes for entering from the sliding area 62 to the working area 61 is fixed to a front portion of the slide 33 through a supporting pole. Upper and lower outer ends of the frame body 63 are disposed near to a lower surface of an upper open/close cover 53 described below and an upper surface of the bed 12, and left and right outer ends thereof are disposed as space is formed between left and right inner surfaces of the side enclosing cover 45, so as to allow the slide 33 to move in the Z-axis direction. The space formed at an outside of the left and right outer ends of the frame body 63 is fixed to the left and right outer ends of the frame body 63 at one end thereof, and the other end is obscured by left and right accordion covers 64a, 64b fixed to the left and right inner surfaces of the side enclosing cover 45. An interspace between an inner circumference of the passing hole of the bearing portion 37 formed in the frame body 63 by cutting and an outer circumference of the bearing portion 37 is fixed to the bearing portion 37 at one end thereof, and the other end is obscured by a passing hole accordion cover 65 fixed to an end portion of the passing hole of the frame body 63. By the left and right accordion covers 64a, 64b and the passing hole accordion cover 65, the separating cover 66 is formed, the cover 66 separating the inside of the side enclosing cover 45 into the working area 61 and the sliding area 62.

FIG. 3 is a plan view showing the grinding machine shown in FIG. 1 as an overhead view. An open port 52 to be an open portion capable of overlooking almost all of the working area 61 and the sliding area 62 is formed on an upper portion of the side enclosing cover 45, and the upper open/close cover 53 is disposed on the open port 52.

As shown in FIG. 3, the upper open/close cover 53 is formed to the size of covering the whole of the open port 52 and in the form of plates. A bracket 54 is mounted parallel to the linear guide 31, on an upper end of the side enclosing cover 45 formed uprightly at the rear portion of the sliding area 62, and by a pair of hinges 55 mounted on the bracket 54, the upper open/close cover 53 is pivoted on the upper end of the side enclosing cover 45 in a rear position of the machine so as to be openable and closable by a turning mechanism.

Further, a pair of gas cylinders 59 to assist an open/close operation is installed in both sides of the bracket 54 and the upper open/close cover 53. The gas cylinder 59 is installed in the upper open/close cover 53 at the rear portion thereof, and piston rods projecting from the top of cylinder are connected to the bracket 54, so as to assist the open/close operation to an open position A shown in FIG. 1 of the upper open/close cover 53. Furthermore, gas is encapsulated into the inside of gas cylinders 59, so as to bias the upper open/close cover 53 in an extending direction of the cylinder shaft, that is, in an opening direction of the upper open/close cover 53 by the effect of the gas.

Further, a lever mechanism 69 is installed in a front portion of the upper open/close cover 53, so as to be latched together with the side enclosing cover 45 and to prevent the upper open/close cover 53 from opening. When the lever mechanism 69 is released, the upper open/close cover 53 opens to the open position A by an effect of the cylinder, and if the upper open/close cover 53 is desired to be closed, a worker P moves the upper open/close cover 53 in a shrinking direction of the gas cylinder 59, so that the upper open/close cover 53 is latched together at the close position by the effect of the lever mechanism 69.

Then, the upper open/close cover 53 contacts the circumference edge of side enclosing cover 45, so as to be separated from the outside of machine, and approaches the separation cover 66, so as to separate the side enclosing cover 45 into the working area 61 and the sliding area 62.

Therefore, if the upper open/close cover 53 is closed, the coolant is prevented from scattering outside from the working area 61, and the coolant and the grinding dust are prevented from scattering from the working area 61 to the sliding area 62.

On the other hand, a workpiece taking out port 56 as an opening portion is formed in a site of the upper open/close cover 53 corresponding to the workpiece W, so as to take out the workpiece W when the upper open/close cover 53 is closed, and an open/close door 57 is installed in the workpiece taking out port 56, the door 57 being slidable in an anteroposterior direction so as to form an opening portion. Therefore, the taking out of workpiece W or the replacement of grinding wheel can be performed from the opening portion in an open condition of the open/close door 57.

The open/close door 57 comprises a window portion 57a formed of reinforced plastic, and a window frame 57b in which the window portion 57a is inserted, the frame 57b supported by slide rails 58 mounted on the upper open/close cover 53 at the both end portions thereof. Further, a rodless cylinder 73 to automatically open/close the open/close door 57 is mounted beside one of the slide rails 58.

Further, it is preferable that the length of open/close door 57 in the workpiece supporting direction is large enough for a part of the workpiece to be visible, and the length of open/close door 57 in the sliding direction of the grinding wheel head 30 is large enough for a part of the grinding wheel G to be visible from the open/close door 57 at the stop of the grinding work. At the grinding work, the workpiece W and the grinding wheel G contact each other, but at the stop of the grinding work, the workpiece W and the grinding wheel G depart from each other, therefore it is necessary to be visible from the open/close door 57 in order to confirm the state of the grinding wheel G and perform inspections etc. at the stop of the grinding work.

Further, it is preferable that the length of open/close door 57 in the workpiece supporting direction is larger than the maximum length of the workpiece W, and the length of open/close door 57 in the sliding direction of the grinding wheel head 30 is larger than the maximum diameter of the workpiece W. As described above, the function of open/close door 57 is to confirm the state of the grinding wheel G and perform inspection, but it is intended that the loading/unloading of the workpiece W can be also performed from the opening portion of the open/close door 57. Because the replacement of grinding wheel G is conducted at an appropriate time according to the working frequency, but the replacement of workpiece W must be conducted at every working time, and if this is accompanied by the open/close operation of the upper open/close cover 53 or the slide open/close cover 53s, a drastic decrease in the working efficiency or production efficiency is caused.

Again, referring to FIG. 1, a coolant chute 13 is installed in a part of the bed 12 forming a lower portion of the working area 61, so as to receive the coolant discharged from the coolant supply nozzle 47 to the grinding point. An exhaust conduit 71 of a duct device 70 is inserted into the bed 12 from an opening portion of the rear surface.

The outer surface of exhaust conduit 71 is closed over the entire length, so as to form a fluid passage of rectangular cross-sectional shape capable of substantially keeping an air sealing, and the cross-sectional shape comprises a sectional area large enough for the coolant to flow at the lower portion of the rectangular cross-sectional shape, and simultaneously for a certain volume of mist to pass at the upper portion. Further, the exhaust conduit 71 extends immediately below the working area 61, and the upper surface of top portion is opened, so as to enclose the outer circumference of lower end portion of the coolant chute 13 in an airtight condition, and to receive the fluid from an opening of lower end of the coolant chute 13. A mist recovery conduit 72 branches from an opening of upper surface just before the rear end portion of the exhaust conduit 71, and extends upward, so as to be connected to an inhalation port 60a of a mist collector 60 mounted on a mounting board 74. The mist collector 60 is publicly known, and operates to inhale the mist from the inhalation port 60a by a vacuum effect and to separate the mist into air components and liquid components, for example, by centrifugal separation, so as to exhaust the air components to air and to reflux the liquid components to a coolant storage tank 52 of the coolant supply unit 51.

The coolant supply unit 51 operates to store the coolant in the tank 52, to pump up the coolant in the tank 52 by a pump unit (not shown), to send the coolant from a discharging pipe 67 to a pipe line 47a through a flexible hose 68, and to supply the coolant from the coolant supply nozzle 47 mounted on the bearing portion 37 to a neighborhood of the grinding point at which the grinding wheel G grinds the workpiece W.

Next, a grinding work in the first preferred embodiment, and along with this, a loading/unloading of the workpiece and a replacement of the grinding wheel will be explained.

The workpiece W is loaded after opened by an open/close operation of the upper open/close cover 53 or the slide open/close cover 53s. Or, it is loaded from an opening portion after the open/close door 57 is opened. The worker P is located in a working space where the loading/unloading of the workpiece and the replacement of the grinding wheel can be conducted.

When the workpiece W is loaded between the left and right work heads 24, 26, left and right servomotors (not shown) are driven, the left and right work heads 24, 26 get closer to each other by a left and right work head moving device, the workpiece W is sandwiched between left and right centers 24a, 26a, the open/close door 57 is closed, and the grinding work is started. Left and right work head servomotors are rotated synchronously, the workpiece W is driven to rotate from both ends. The slide 33 is moved in the Z axis direction by a Z axis linear motor 32, so as to align the grinding wheel G with a working site in the Z axis direction. A X-axis linear motor 27 is driven, the grinding wheel head 30 is carried forward at a fast feeding speed, a rough grinding feeding speed, an accurate grinding feeding speed, the coolant is supplied from the coolant supply nozzle 47 to a working zone by the coolant supply unit 51, and the working site of the workpiece W is ground by the grinding wheel G driven to rotate by a driving motor 40 through a belt 42.

The coolant supplied in the working zone lubricates and cools the grinding point where the grinding wheel G grinds the workpiece W, and drops into the coolant chute 13 opened just below the working zone together with the grinding dust, and is recovered in the coolant storage tank 51a or the mist collector 60 through the exhaust conduit 71 together with the mist produced simultaneously.

The frame body 63 of the separating cover 66 is moved in the Z axis direction according to the movement of slide 33 in the Z axis direction, and the left and right accordion covers 64a, 64b fixed to left and right outer edges of the frame body 63 in one end thereof are elongated and contracted, so as to obscure a space formed between outsides of the left and right outer edges of the frame body 63 and left and right inner surfaces of the side enclosing cover 45. When the bearing portion 37 of grinding wheel head 30 moves forward or backward in the X axis direction, a passing hole accordion cover 65 fixed to the outer circumference of the bearing portion 37 in one end thereof is elongated and contracted, so as to obscure an interspace between the bearing portion 37 and the passing hole. Further, in the upper part, the upper open/close cover 53 seals the grinding machine body 11 together with the side enclosing cover 45.

Therefore, the separating cover 66 comprising the left and right accordion covers 64a, 64b and the passing hole accordion cover 65, the upper open/close cover 37, and the side enclosing cover 45 separate the inside of the side enclosing cover 45 into the working area 61 where the grinding wheel G grinds the workpiece W and the sliding area 62 where the grinding wheel head 30 is guided in the Z axis and X axis directions by the linear guides 31, 35, so that a decrease in a guide accuracy and feeding accuracy can be prevented, the decrease in the accuracies being caused by the penetration of grinding dust and coolant into the linear guides 31, 35 and the linear motor 27, 32.

When the grinding work of the workpiece W is completed, the grinding wheel head 30 is moved backward at a rapid feedrate, after the completion of backward movement of grinding wheel head 30 it is opened by the open operation of upper open/close cover 53, slide open/close cover 53s or open/close door 57, the workpiece W is taken out to the outside of machine, and then one grinding cycle is completed.

And, at the time of replacement of grinding wheel, the worker P operates the lever mechanism 69, so as to release the latched condition between the upper open/close cover 53 and the side enclosing cover 45. The upper open/close cover 53 is whirled to the opening position A by an effect of the gas cylinder 59, so that the upper open/close cover 53 is opened. When the upper open/close cover 53 is opened, the upper portions of working area 61 and sliding area 62 separated by the separating cover 66 are opened.

By this, the worker P can replace the grinding wheel G installed in the bearing unit 37 from the upside of grinding wheel head 30. Further, at the replacement of grinding wheel all of the devices in the side enclosing cover 45 are visible, so that for example, states of the belt 42, the linear guides 31, 35 etc. can be confirmed.

“Design Learning of Machine Tool (Basic Edition)” edited by Japan Machine Tool Builders' association (p. 64 to p. 66), describes below. That is, “Usability in view of ergonomics generally is determined by factors such as (1) compatibility of size, (2) operability, (3) information display characteristic, (4) safety, (5) environmental adaptability, (6) design characteristic, (7) functionality. The compatibility of size means for example, a matching between a grip size of lever and a size of human hand or machine tool. The operability means a matching between human motility characteristic or muscle strength and an operation characteristic of the product itself. The information display characteristic means for example, a relationship between size, brightness etc. of character, figure etc. shown in display screen of NC unit and human visual feature. The safety means existence or nonexistence of factors causing harm to operators at the operation, and the environmental adaptability means existence or nonexistence of adverse effects on human beings by ambient noise, vibration, inadequate illumination, working liquid etc. The design characteristic, which is dependent on cultures of the period and the region, means whether the formative sense is preferred by workers. The functionality means whether it can functionally provide an adequate satisfaction, based on the factors described above. To satisfy the factors is very important for maximizing mental and physical ability of human beings having a limitation of “fatigue”. Further, the fatigue decreases concentration power of workers, also becomes a source of accidents, and finally decreases the productivity of machine tool. It is generally difficult to satisfy all of the factors, so that consideration that priorities are set to each product is conducted. Recently, the safety, the environmental adaptability and the design characteristic have also been emphasized.”

FIG. 9 is disclosed in the literature described above, and shows an evaluation result of an upright position working point in view of muscle activity and energy metabolism. By this, it is recognized that the vicinity of elbow height is preferable as an operation position, and no keeping from body position not less than 300 mm is also preferable.

FIG. 10 is disclosed in the literature described above, and shows a front horizontal plane area to facilitate a working which is conducted near a height of body section. In case of M5PC (M5PC means a man having the 5^th-lowest body height out of 100 men, and similarly, W5PC means a woman having the 5^th-lowest body height out of 100 women, M95PC means a man having the 95^th-lowest body height out of 100 men), it is recognized that the front side within 450 mm is a distance for a comfortable operation. Further, it shows that a distance for easy reach of hands changes along with a line inclined at angle of about 60 degrees to a floor face.

In FIG. 9 and FIG. 10, the body heights of workers are based on the distribution shown in FIG. 2.7.1 in the literature described above.

When a position size of each part is ergonomically investigated based on the data described above, the results are shown below.

FIGS. 4A to 4E is a schematic view showing the position and dimensions of each part in the first preferred embodiment.

According to FIG. 9, if more than 1200 mm, a preferable result of the upright position working point in view of muscle activity and energy metabolism cannot be obtained. Therefore, in the first preferred embodiment, as shown in FIG. 4A, it is preferable that the height of machine upper face (Hh) is not more than 1200 mm from the floor face B.

Further, according to FIG. 10, if the workers P have body heights within the range of 90% eliminated each 5% in the upper and lower limits, when the workers P replace the workpiece W and the grinding wheel G, in a case that the height of machine upper face is 1000 mm, it is preferable that the opening portion is located within the range of 400 mm to 800 mm from the machine front face, and in a case that the height of machine upper face is 1200 mm, it is preferable that the opening portion is located within the range of 300 mm to 650 mm from the machine front face. Therefore, as shown in FIG. 4B, it is preferable that the position Lk of the opening portion from the machine front face is not less than 600 mm.

Similarly, based on the ergonomic data in FIG. 10, as shown in FIG. 4C, it is preferable that the rotation center position of the workpiece W is within a range of LW1 to LW2, and LW1 and LW2 are 200 mm and 400 mm respectively. Further, it is preferable that the position is within a range of H1 to H2 from the floor face B, and H1 and H2 are 850 mm and 1000 mm respectively.

Further, as shown in FIG. 4D, it is preferable that the rotation center position of the grinding wheel shaft 38 is within a range of LG1 to LG2, and LG1 and LG2 are 250 mm and 500 mm respectively. Further, it is preferable that the position is within a range of H3 to H4 from the floor face B, and H3 and H4 are 850 mm and 1000 mm respectively.

For the reason described above, in a case that the loading/unloading of the workpiece and the replacement of the grinding wheel are conducted, for example, from the opening portion of open/close door 57 shown in FIG. 3, it is preferable that the opening portion is formed within a range obtained by a calculation that based on the ergonomic data in FIG. 10, from numerical values of 300 mm to 800 mm from the machine front face, and 1000 mm to 1200 from the floor face, in consideration of workability of the workers of the M5PC and W5PC sides, adjusted values of 100 mm are reduced, that is, the range is 200 mm to 700 mm from the machine front face, and 900 mm to 1100 mm from the floor face.

Further, the rotation center position of the workpiece W is disposed within a range of 200 mm to 400 mm, and 850 mm to 1000 mm from the floor face B, and also the rotation center position of the grinding wheel shaft 38 is disposed within a range of 250 mm to 500 mm, and 850 mm and 1000 mm from the floor face B, so that the ergonomic data described above can be satisfied.

Simultaneously, it is preferable that the straight line extending from the center position of opening portion of open/close door 57 to the rotation axis of the workpiece W and the rotation axis of the grinding wheel shaft 38 perpendicularly is almost along with the line of about 60 degrees previously shown in FIG. 10, for example, lines within a range of 45 degrees to 75 degrees. Further, the center position of the opening portion of the open/close door 57 means an intersection of two diagonal lines of a rectangular opening portion of the open/close door 57 shown in FIG. 3.

FIG. 4E shows the lines l₁ and l₂. Further, the upper open/close cover 53 comprises the workpiece taking out port 56 formed as an opening portion, and the open/close door 57 is formed on the opening portion. It is preferable that the inclined angles O₁, O₂ of the lines l₁ and l₂ perpendicular to the center position C of the opening portion, the rotation axis O of the workpiece W and the rotation axis O₂ of the grinding wheel shaft 38 to the line H parallel to the floor face are within a range of 45 degrees to 75 degrees.

Further, it is preferable that the grinding wheel comprises CBN (Cubic Boron Nitride) grinding wheel, a disk for grinding wheel Wh comprises aluminum, titanium or those alloys, and the outer diameter of the grinding wheel G is not less than 100 mm and not more than 200 mm.

According to the first preferred embodiment described above, the easy maintenance and inspections of mechanisms arranged therein, an increase in visibility when the states of a workpiece and a grinding wheel are confirmed, and the easy loading/unloading of the workpiece and the easy replacement of the grinding wheel can be enhanced.

Further, the machine (grinding machine) comprising the height of the machine upper surface, the rotation center position of the workpiece W, and the position of the grinding wheel shaft 38, as shown by dotted lines in FIG. 4A and FIG. 4B, enables the workers P to load/unload the workpiece and replace the grinding wheel mainly by arm operation without motions putting stress on their waists such as stretch motion, bow motion, so that the working efficiency and the productivity can be enhanced, and also the safety of the workers can be enhanced. Further, the grinding wheel comprising CBN can be formed to be smaller in the outer diameter, and the disk Wh comprising aluminum, titanium or those alloys can be formed to be lighter in the weight, and also by this the working efficiency, the productivity, and also the safety of the workers can be enhanced.

Further, in the first preferred embodiment a structure that the hinge 55 is mounted in the rear position of side enclosing cover 45 so as to allow the upper open/close cover 53 to be openable and closable from the front portion to the rear portion has been explained, but the invention is not limited to such a structure, the other structure that the hinge 55 is mounted in the upper position on the side of side enclosing cover 45 so as to allow the upper open/close cover 53 to be openable and closable in the side portion of the grinding machine body 11 can be adopted. Furthermore, the mounting method is also not limited to a method using the hinge 55, but any mechanism that can swivel the upper open/close cover 53 can be adopted.

Second Embodiment

FIG. 5 is a side view showing a cylindrical grinding machine in a second preferred embodiment according to the invention.

The cylindrical grinding machine 10 comprises a slide open/close cover 53s to slide from the front portion to the rear portion based on a horizontal slide mechanism being public known, instead of swiveling the upper open/close cover 53.

In order to allow the slide open/close cover 53s to slide from the front portion to the rear portion, it is necessary that the height of attachment device 50 is installed lower than the sliding height of slide open/close cover 53s, so as to prevent the attachment device 50 installed in the rear portion of grinding machine body 11 from interfering.

Also in the second preferred embodiment, similarly to the first preferred embodiment, it is preferable that the values of the height of machine upper face (Hh), the rotation center position of the workpiece W (LW1, LW2, H1, H2), and the rotation center position of the grinding wheel shaft 38 (LG1, LG2, H3, H4) are similar to the values described in the first preferred embodiment.

Further, it is preferable that the grinding wheel comprises CBN (Cubic Boron Nitride) grinding wheel, a disk for grinding wheel Wh comprises aluminum, titanium or those alloys, and the outer diameter of the grinding wheel G is not less than 100 mm and not more than 200 mm.

According to the second preferred embodiment described above, similarly to the first preferred embodiment, the easy maintenance and inspections of mechanisms arranged therein, an increase in visibility when the states of the workpiece W and the grinding wheel G are confirmed, and the easy loading/unloading of the workpiece and the easy replacement of the grinding wheel can be enhanced. Further, the slide open/close cover 53s does not need an open/close space in the upper direction, and does not need a power against gravity at the open/close operation, so that the open/close operation can be realized by a simple slide mechanism, and can be easily performed by the workers P.

Third Embodiment

FIG. 6A is a schematic view showing a cylindrical grinding machine in a third preferred embodiment when an upper open/close door 57u is closed, and FIG. 6B is a schematic view showing a cylindrical grinding machine in the third preferred embodiment when the upper open/close door 57u is opened.

As shown in FIG. 6A, the cylindrical grinding machine 11 comprises an open/close door 57u as an opening portion in the upper open/close cover 53, by which the upper surface and/or the front surface of the machine can be opened/closed with a central focus on the hinge 570. As shown in FIG. 6B, the open/close door 57u is opened by the workers P with a central focus on the hinge 570 by hand, so that the workers P can contact the grinding wheel G and the workpiece W. In this case, it is preferable that the height (H_L) of the lower end of opening portion of machine front surface is not less than 1000 mm from the bottom surface.

Also, it is preferable that the values of the height of machine upper face (Hh), the rotation center position of the workpiece W (LW1, LW2, H1, H2), and the rotation center position of the grinding wheel shaft 38 (LG1, LG2, H3, H4) are similar to the values described in the first preferred embodiment.

Further, it is preferable that the grinding wheel comprises CBN (Cubic Boron Nitride) grinding wheel, a disk for grinding wheel Wh comprises aluminum, titanium or those alloys, and the outer diameter of the grinding wheel G is not less than 100 mm and not more than 200 mm.

According to the third preferred embodiment described above, as shown in FIG. 6B, with just the opening operation in the upper direction of open/close door 57u by the workers P, the easy loading/unloading of the workpiece W and the easy replacement of the grinding wheel and the increase in visibility when the states of the workpiece W and the grinding wheel G are confirmed can be enhanced. Further, as shown in FIGS. 6A, 6B, the workers can load/unload the workpiece and replace the grinding wheel mainly by arm operation without motions putting stress on their waists such as stretch motion, bow motion.

Fourth Embodiment

FIG. 7A is a schematic view showing a cylindrical grinding machine in a fourth preferred embodiment when an open/close door of sliding type is closed, and FIG. 7B is a schematic view showing a cylindrical grinding machine in the fourth preferred embodiment when the open/close door of sliding type is opened.

As shown in FIG. 7A, the cylindrical grinding machine 10 comprises an open/close door 57s to slide from the front portion to the rear portion on the machine upper surface so as to be openable and closable as an opening portion in the upper open/close cover 53. The open/close door 57s slides on the machine upper surface by hand of the workers P or an open/close mechanism (not shown), so that as shown in FIG. 7B the workers P can contact the grinding wheel G and the workpiece W. Further, also in the fourth preferred embodiment, it is preferable that the height (H_L) is not less than 1000 mm from the bottom surface.

According to the fourth preferred embodiment described above, in addition to the preferable advantages of the first preferred embodiment, as shown in FIG. 7B, with just the opening operation due to the sliding of open/close door 57s by the workers P, the easy loading/unloading of the workpiece W and the easy replacement of the grinding wheel and the increase in visibility when the states of the workpiece W and a grinding wheel G are confirmed can be enhanced. In this case, the workers P can conduct the opening operation more easily due to the sliding of open/close door 57s than the structure shown in FIG. 6A, and can also keep the open/close door 57s as it is.

Fifth Embodiment

FIG. 8 is a side view showing a fifth preferred embodiment. In the fifth preferred embodiment, a handling robot conducts the loading/unloading of the workpiece W and the replacement of the grinding wheel G.

The handling robot 100 comprises a robot body 101, a first arm 103 mounted on the robot body 101 through a first arm turning portion 102 being rotatable, a second arm 105 mounted through a second arm turning portion 104 being rotatable, and a handling portion 106 mounted on the end portion of second arm 105 apart from the robot body 101, the portion 106 being rotatable and capable of grasping. Further, the handling robot 100 comprises a control means and actuators at each part (not shown) based on public known technical means, so that for example, the handling robot 100 performs works, such as the loading/unloading of the workpiece W and the replacement of the grinding wheel G based on a remote control by an operator.

In the works of the loading/unloading of the workpiece W and the replacement of the grinding wheel G, first, the handling robot 100 is moved to such a position that the robot body 101 does not contact the machine front surface. Next, the first arm 103 and the second arm 105 are operated to allow the handling portion 106 to approach, and grasp or release the objective workpiece W or grinding wheel G, so that the workpiece W can be carried in/out or the grinding wheel G can be replaced.

Further, it is preferable that the height of the upper open/close cover 53, the slide open/close cover 53s, or the machine upper surface or the lower end of the opening portion is not higher than such a height that the loading/unloading of the workpiece W and the replacement of the grinding wheel G can be conducted from a working space, centering around the lift up/down operation. Alternatively, it is preferable that the height of the upper open/close cover 53, the slide open/close cover 53s, or the machine upper surface or the lower end of the opening portion is not higher than a height of the arm turning portion nearest to the handling portion 106 of the handling robot 100.

Since two arms are used in the preferred embodiment, so that the nearest arm turning portion corresponds to the second arm turning portion 104. Further, the handling robot 100 can be replaced with the workers P.

According to the structure described above, even if the loading/unloading of the workpiece W and the replacement of the grinding wheel G are conducted by the handling portion 106, the arm portion and the handling portion never contact the machine or the cover at the operation of the handling robot 100. Further, the loading/unloading of the workpiece W and the replacement of the grinding wheel G can be conducted from a working space, centering around the lift up/down operation, and also can be conducted mainly with a central focus on the operation of arm portion, so that the handling robot is not required to move up/down and can prevent vain consumption of energy.

The operation of the handling robot 100 described above is applicable to the operation of the worker P of a human being. The first arm turning portion 102 of the handling robot 100 corresponds to a human shoulder, the first arm corresponds to an upper arm, the second arm turning portion 104 corresponds to an elbow, the second arm 105 corresponds to a front arm, and the handling portion 106 corresponds to a hand including a wrist.

Therefore, if a human being or the handling robot equivalent to a human being is set as the workers P, similarly to the first preferred embodiment, it is preferable that the values of the height of machine upper face (Hh), the rotation center position of the workpiece W (LW1, LW2, H1, H2), and the rotation center position of the grinding wheel shaft 38 (LG1, LG2, H3, H4) are similar to the values described in the first preferred embodiment.

Further, it is preferable that the grinding wheel comprises CBN (Cubic Boron Nitride) grinding wheel, a disk for grinding wheel Wh comprises aluminum, titanium or those alloys, and the outer diameter of the grinding wheel G is not less than 100 mm and not more than 200 mm.

According to the fifth preferred embodiment, the easy loading/unloading of the workpiece and the easy replacement of the grinding wheel can be enhanced. Further, if a human being or the handling robot comprising an object recognition tool equivalent to a human being is set as the workers P, similarly to the other preferred embodiments, the easy maintenance and inspections of mechanisms arranged therein, and an increase in visibility when the states of the workpiece and the grinding wheel are confirmed can be enhanced, and the working efficiency, the productivity and the safety of the workers can be also enhanced.

Claims

1. A grinding machine, comprising:

a workpiece supporting/driving device anteriorly mounted on a bed, and supporting a workpiece to be rotatably driven;

a grinding wheel head comprising a bearing portion supporting a wheel spindle to be rotatably driven on which a grinding wheel is mounted, and a base mounted over the bed to be relatively movable to the workpiece through a grinding wheel head sliding mechanism;

a grinding wheel head feeder moving the grinding wheel head forward or backward to the workpiece supporting/driving device;

a coolant supply unit supplying a coolant to a working area in which the grinding wheel grinding processing the workpiece;

a cover covering internal devices such as the workpiece supporting/driving device, the grinding wheel head, the grinding wheel head feeder, the coolant supply unit; and

an open/close door formed on a part of an upper surface in working space side of the cover, being capable of at least loading/unloading of the workpiece and replacing the grinding wheel.

2. The grinding machine according to claim 1, wherein:

the cover comprises an upward open/close door or a sliding open/close door at least a part of the upper surface.

3. The grinding machine according to claim 2, wherein:

the open/close door is formed on the upward open/close door or the sliding open/close door.

4. The grinding machine according to claim 2, wherein:

the open/close door is formed within a region of not less than 200 mm and not more than 700 mm from the front face of machine, and not less than 900 mm and not more than 1100 mm from a floor face.

5. The grinding machine according to claim 1, wherein:

the open/close door comprises large size enough for a part of the workpiece to be visible in the workpiece supporting direction, and the open/close door comprises large size as a length in a sliding direction of the grinding wheel head enough for a part of the grinding wheel to be visible from the open/close door in the sliding direction of the grinding wheel head at the stop of the grinding work.

6. The grinding machine according to claim 1, wherein:

the open/close door comprises the size larger than the maximum length of the workpiece in the workpiece supporting direction and larger than the maximum diameter of the grinding wheel head in the sliding direction.

7. The grinding machine according to claim 1, wherein:

the workpiece comprises a rotation center position at not less than 200 mm and not more than 400 mm from the front face of machine, and comprises a rotation center position at not less than 850 mm and not more than 1000 mm from the floor face.

8. The grinding machine according to claim 1, wherein:

the wheel spindle comprises a center position thereof at not less than 250 mm and not more than 500 mm from the front face of machine, and at not less than 850 mm and not more than 1000 mm from the floor face.

9. The grinding machine according to claim 7, wherein:

the open/close door is formed on a region in which the workpiece or the grinding wheel head is replaceable in an open condition.

10. The grinding machine according to claim 1, wherein:

the grinding machine comprises a height of not less than 900 mm and not more than 1100 mm from the floor face.

11. The grinding machine according to claim 1, wherein:

the grinding wheel comprises an outer diameter of not less than 100 mm and not more than 200 mm, and comprises CBN grinding wheel having aluminum or titanium disk as a core.

12. A grinding machine, comprising:

a workpiece supporting/driving device anteriorly mounted on a bed, and supporting a workpiece to be rotatably driven;

a grinding wheel head comprising a bearing portion supporting a wheel spindle to be rotatably driven on which a grinding wheel is mounted, and a base mounted over the bed to be relatively movable to the workpiece through a grinding wheel head sliding mechanism;

a grinding wheel head feeder moving the grinding wheel head forward or backward to the workpiece supporting/driving device;

a coolant supply unit supplying a coolant to a working area in which the grinding wheel grinding processing the workpiece; and

a cover covering internal devices such as the workpiece supporting/driving device, the grinding wheel head, the grinding wheel head feeder, the coolant supply unit, and formed below a height of an arm turning portion just proximal to a handling portion of a working robot performing a lift up/down operation, so that a loading/unloading the workpiece and a replacement of the grinding wheel can be conducted from a working space in a front face, centering around the lift up/down operation in the internal portion of the grinding machine.

13. The grinding machine according to claim 12, wherein:

the cover comprises an open/close door within a region in which the lift up/down operation can be performed.

14. The grinding machine according to claim 12, wherein:

the loading/unloading of the workpiece, the replacement of the grinding wheel, and the lift up/down operation are conducted by the robot.

15. The grinding machine according to claim 14, wherein:

the cover is formed below the height of the turning portion of the robot.

16. A grinding machine, comprising:

a workpiece supporting portion supporting a workpiece to be processed on a first rotating shaft;

a grinding wheel supporting portion supporting a grinding wheel to process the workpiece on a second rotating shaft;

a side cover enclosing the workpiece supporting portion and the grinding wheel supporting portion from the side;

a upper cover enclosing a first opening portion formed on the upper side by the side cover; and

an open/close member formed on a working space side of the upper cover, to open/close a second opening portion for a loading/unloading of the workpiece, and a replacement of the grinding wheel; and

the second opening portion is formed on the upper cover, so that a straight line perpendicular to the first and second turning shafts in a center position thereof comprises a certain inclined angle to a floor face.

17. The grinding machine according to claim 16, wherein:

the second opening portion is formed on the upper cover, so as to comprise an inclined angle of 45 degrees to 75 degrees as the certain inclined angle.

18. The grinding machine according to claim 8, wherein:

the open/close door is formed on a region in which the workpiece or the grinding wheel head is replaceable in an open condition.