Machine and Method for Machining Workpieces of Wood, Plastic Material and the Like

With the machine, workpieces are machined as they pass through the machine. At least one of the spindles of the machine is coupled with an adjusting unit with which the spindle, for producing a contour on the workpiece, can be adjusted transverse to the throughfeed direction of the workpiece during workpiece throughfeed. The adjustment of the adjusting unit is realized as a function of the advancing speed of the workpiece and/or the workpiece position upon throughfeed of the workpiece. The adjusting unit has such a stiffness and/or low clearance and/or positioning precision that the end products machined from the workpieces after exiting from the machine can be used without further post-machining. The end products have such a geometry precision and surface quality that further post-machining is no longer required.

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Description
BACKGROUND OF THE INVENTION

The invention concerns a machine as well as a method for machining workpieces of wood, plastic material, and the like, wherein the machine has at least one transport path for the workpieces on which the workpieces are transported through the machine, and has tools that are fixedly seated on spindles with which the workpieces are machined as they pass through the machine.

It is known to manufacture end products from workpieces in several steps on stationary machining centers. Such end products are used, for example, in the furniture industry, for example, as arm rests, legs of furniture, cabinet parts, and the like. The manufacture of such end products is very machine-intensive and time-intensive. Each workpiece must be clamped on the machining center so that it can be machined by the corresponding tool. The machining quality, in particular the surface quality, is generally low so that post-machining is still required.

The invention has the object to configure the machine of the aforementioned kind and the method of the aforementioned kind in such a way that workpieces can be machined to end products in a simple way at high efficiency but still with high precision, in particular with high surface quality.

SUMMARY OF THE INVENTION

This object is solved for the machine of the aforementioned kind in accordance with the invention in that at least one of the spindles is coupled with an adjusting unit having at least one adjusting axis, wherein the spindle, for producing a contour on the workpiece, is adjustable by the adjusting unit transverse to the throughfeed direction of the workpiece during the workpiece throughfeed as a function of the advancing speed of the workpiece and/or the workpiece position as the workpiece passes through the machine, and wherein the adjusting unit has such a stiffness and/or low clearance and/or positioning precision that the end products machined from the workpieces, when exiting from the machine, can be used without further post-machining.

The object is solved for the method of the aforementioned kind in accordance with the invention in that, based on a desired and freely selectable geometry or contour, an NC (numerical control) program for the machine control unit is generated that upon throughfeed of the workpieces is executed and repeated for each workpiece, in that the travel or the position of the workpieces through the machine is detected, in that at least one contour producing tool is moved transverse to the transport direction of the workpieces by means of at least one adjusting unit as a function of the desired contour, of tool data, and of the workpiece position, and in that the adjusting unit has such a stiffness and/or low clearance and/or positioning precision that the finish machined workpieces, when exiting from the machine, have such a geometry precision (trueness) and surface quality that they can be used without further post-machining.

With the machine according to the invention, it is possible to machine the workpieces in a throughfeed method with high precision and in particular with high surface quality so that the end products can be used immediately for their intended purpose. Post-machining of the workpiece after exiting from the machine is not required. The machine comprises at least one spindle which is coupled with an adjusting unit so that the spindle with the tool seated thereon, as the workpiece travels through the machine, can be adjusted transverse to the travel direction of the workpiece in accordance with the contour to be produced. As an adjusting unit, a device is employed that is distinguished by a high positioning precision and/or stiffness and/or low clearance. A surface quality can be achieved which at least corresponds to the finish quality of the conventional surface machining of workpieces. Finish quality is to be understood as such a machining quality that post-machining of the end products is not required.

During milling of the workpiece with the rotating tool, a corrugation pattern is produced on the surface of the workpiece. The spacing of the corrugations results from the chip removal in cycloidal sections during circumferential face milling or profile milling and is referred to as knife mark or planing mark. The shorter this knife mark, the smoother and finer the workpiece surface. The length of the knife mark depends on the advancing speed vf of the workpiece, on the rotary speed n of the spindle, and on the number z of the surface-generating knives of the tool. When all cutting edges work on the same cutting circle, the knife impacts correspond to the pitch fz according to fz=vf/(n·z). Without special precautionary measures, even for multi-knife tools only one cutting edge is impressed on the machined surface due to the tolerances. In this so-called single-knife finish, z=1 is applied for calculating the knife impact with the equation for the pitch. Therefore, by adjusting these three parameters as the workpiece travels through the machine, an extremely small knife mark can be achieved which leads to the high surface quality of the end product. A good quality and a high quality surface result for planing/knife marks between 1 mm and 2 mm. The uniformity of the knife marks or of the corrugation pattern is also decisive for a high surface quality. Non-uniform knife marks can be the result of, for example, tool or workpiece vibrations, fluctuations of the advancing speed or rotary speed of the tool, and clearance-exhibiting adjusting movements of the tool and can lead to the workpieces not being useable or having to be post-machined. The rotary speed of the spindle and thus of the tool is adjusted to the advancing speed of the workpiece such that the desired high surface quality, i.e., uniformity of the knife mark and identical knife mark length, can be achieved on the end product.

Since the adjusting unit is embodied to at least have low clearance, advantageously however to be free of clearance, the change of the moving direction of the adjusting unit has no negative effect on the surface quality and the uniformity of the planing mark in workpiece machining. The great stiffness of the adjusting unit also contributes to this.

For a uniform advancing speed, depending on the contour and the feed speed of the tool, the relative advancing speed and thus the pitch of the tool changes. For a uniform pitch, i.e., uniform knife mark, upon increasing the relative advancing speed the rotary speed of the tool is to be increased. The travel speed or advancing speed of the workpiece through the machine and the feed speed of the tool is thus coupled to the rotary speed of the spindle in such a way that a very high surface quality results on the end product. For this reason, the rotary speed of the spindle supporting the tool is advantageously at all times adjustable during throughfeed action as a function of the travel speed or advancing speed and the contour of the workpiece such that the knife mark is kept constant. The rotary speed adjustment can be performed by a control unit or feedback control.

Advantageously, the adjusting unit is designed to be free of clearance which is especially advantageous for a high surface quality.

Advantageously, the adjusting unit is a linear drive. With it, it is possible to adjust the spindle with high precision and within a very short time relative to the workpiece such that the desired contour on the workpiece is produced with the desired high surface quality. Since the linear drive has no clearance and a high stiffness, the tool can be very precisely adjusted to the position that is required for contour milling.

The adjusting unit can also be embodied by a ball screw drive. With it, it is also possible to adjust the tool with great precision, free of clearance, and within a very short time to the desired working position in relation to the workpiece passing through. A ball screw drive can also be embodied free of clearance and with high stiffness so that a great positional precision of the spindle or of the tool seated thereon results.

The spindle with the tool is adjusted transverse to the advancing direction of the workpiece through the machine. Advantageously, there exists the possibility to provide the adjusting unit with at least one further adjusting axis. In this way, be means of the adjusting unit, the spindle or the tool can be adjusted within the plane that is defined by the two adjusting axes.

Advantageously, the adjusting axes of the adjusting unit in this case are positioned at a right angle to each other. This can be achieved very simply in that the adjusting unit is embodied in the form of a compound slide carriage whose two carriage parts independent of each other can be adjusted at a right angle to each other.

In order for the position of the workpiece in the machine to be precisely known as it passes through, the workpiece position is detected by at least one measuring device. In this way, the adjusting speed or adjusting movement as well as the rotary speed of the spindle can be adjusted optimally to the advancing movement of the workpiece as it is fed through the machine in order to obtain the desired contour with high contour trueness and surface quality.

In an advantageous embodiment, the measuring device has a measuring roller which is contacting a side of the workpiece that is not to be machined. The measuring roller is advantageously forced under pressure against the workpiece side so that, as the workpiece passes through, no slip between the workpiece and the measuring roller occurs. In this way, the workpiece position in the machine can be determined with high precision.

The measuring roller is seated advantageously on a shaft whose rotation is detected by a rotary encoder. The rotary encoder provides accordingly signals to the machine control unit that, in accordance with the rotary encoder signals, adjusts the moving speed or the moving travel of the adjusting unit as well as the rotary speed of the spindle with respect to high contour trueness and surface quality. The advancing speed or advancing movement of the workpiece in the machine is advantageously coupled by means of the machine control unit with the adjusting speed or adjusting movement of the adjusting unit, advantageously also with the rotary speed of the spindle.

The adjusting unit is preferably a device that can be simply connected to the machine. In this way, there is the possibility of retrofitting machines that are already at hand at the customer with such a device so that these machines are provided with an additional machining possibility for the workpieces.

It is preferred that the machine is a moulder. It enables machining of all four longitudinal sides of the workpiece as the workpiece passes through. In this context, the moulder can be adjusted such that, for example, only at one of the longitudinal sides of the workpiece a contour is produced while the remaining workpiece sides are not machined. However, it is also possible to combine contour milling with a straight planing process and/or profiling of at least one additional longitudinal side of the workpiece in the moulder. In this way, the workpiece can be machined at its different longitudinal sides in different ways in a single pass through the machine.

With the method according to the invention, the geometries or contours can be produced on workpieces with high precision and high surface quality. First, based on a desired and freely selectable geometry or contour, an NC (numerical control) program for the machine control unit is generated. Upon throughfeed of the workpieces through the machine, this NC program is then executed and repeated for each workpiece. The path or the position of the workpieces through the machine is detected. In this context, also the advancing speed can be determined with which the workpiece is transported through the machine. At least one contour-producing tool is moved transverse to the transport direction of the workpiece through the machine by means of at least one adjusting unit as a function of the desired geometry or contour, of tool data such as the tool diameter, and of the workpiece position. The adjusting unit exhibits in this context such a stiffness and/or low clearance and/or positioning precision that the finish machined workpieces (end products) when exiting from the machine have such a geometry precision (trueness) and surface quality that they can be used without further post-machining. After exiting from the machine, the finish machined workpieces have, aside from the high geometry precision, a high surface quality which at least corresponds to the finish quality of conventional surface machining of workpieces. Therefore, the end products which are exiting from the machine can be immediately applied to their intended use. Since the workpiece position, i.e., the leading end of the workpiece and the advancing speed or the advance of the workpieces, is detected in the machine, the high geometry precision and surface quality for machining the workpiece are ensured in a simple way.

With the method according to the invention, the workpieces can be machined such that the uniformity of the planer marks of the tool on the end products after exiting from the machine is not visibly impaired. In particular, at the reversing points of the adjusting unit or at the reversing areas of the contour, taking into account the high stiffness and/or minimal clearance, a high surface quality of the end products can be achieved. The high positioning precision of the adjusting unit moreover leads to a geometry precision of the contour and thus of the end product.

The subject matter of the invention results not only from the subject matter of the individual claims but also from the specifications and features disclosed in the drawings and in the description. Even if they are not subject matter of the claims, they are claimed as being important to the invention inasmuch as they are novel, individually or in combination, relative to the prior art.

Further features of the invention result from the further claims, the description, and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail with the aid of two embodiments illustrated in the drawings.

FIG. 1 shows in front view a machine of the invention in the form of a moulder.

FIG. 2 shows in enlarged illustration a part of the spindle arrangement of the machine according to FIG. 1.

FIG. 3 shows the detail III of FIG. 1 in an enlarged illustration.

FIG. 4 shows in an illustration corresponding to FIG. 2 a second embodiment of a machine according to the invention.

FIG. 5 shows a workpiece that has been produced on the machine according to FIG. 1 or FIG. 4.

FIG. 6 is a schematic of the machine control unit interaction with devices of the machine.

 DESCRIPTION OF PREFERRED EMBODIMENTS

With the moulder described in the following, workpieces of wood, plastic material, and the like are machined by contour milling. End products provided with the desired contour can be produced from the workpieces. Such contour-milled workpieces can be used, for example, in furniture production, for example, as a leg for a chair or table, as arm rests, and the like. The contours of the milled workpieces can have any desired shape and can be freely defined. The contour of the workpieces is produced as the workpiece passes through the machine. The machine has a CNC (computerized numerical control) control unit as well as CNC (computerized numerical control) controlled tool axes.

The moulder is a milling machine with which the workpieces 1 can be machined in a throughfeed process on all four longitudinal sides. Depending on the desired shape of the end product, the workpieces 1 can be machined only on one side but also on several or also on all sides. The workpieces 1 are elongate workpieces which in general have a quadrangular cross section.

For transport of the workpieces 1 through the machine, advancing and transporting rollers 2 are provided which are resting on the workpieces.

In the infeed area of the moulder, there is a straightening table 3 on which the workpieces 1 are supplied to the machine. On the right side of the straightening table 3 in the infeed direction, an edge jointing fence 4 is provided on which the workpiece 1 with its right longitudinal side in transport direction is resting during transport through the machine. The edge jointing fence 4 is adjustable transverse to the transport direction of the workpiece 1 in order to adjust the size of the chip removal on the right longitudinal side of the workpiece 1. The straightening table 3 can be adjusted in vertical direction so that the size of the chip removal at the bottom side of the workpiece 1 can be adjusted.

By means of an infeed opening 5, the workpiece 1 enters a machine chamber of the machine. In the machine chamber, a horizontal bottom planing spindle is provided on which a schematically illustrated planing tool 6 is fixedly seated. It machines by chip removal the bottom side of the workpiece 1 passing through the machine, preferably by planing. In transport direction of the workpiece 1 downstream of the planing tool 6, a vertical right spindle is provided on which a tool 7 is seated. It can machine the right longitudinal side of the workpiece 1 in transport direction. In the embodiment, the right longitudinal side is planed straight with the tool 7. In this case, the tool 7 is a planer head with straight knives. The tool 7 can however also be a profiling tool with which on the right workpiece side a profile is produced. In transport direction of the workpiece 1 downstream of the vertical right spindle, a vertical left spindle is provided on which a tool 8 is seated. It machines the left longitudinal side of the workpiece 1 in transport direction.

When passing through the machine, the workpieces 1 are resting on a machine table 9 which forms a transport path on which the workpieces 1 are transported through the machine by resting thereon. The machine table 9 is fixed on the machine and forms a horizontal support plane and reference plane for the workpieces 1.

In transport direction of the workpieces 1 downstream of the right tool 7, the workpiece 1 is further guided on a fence (not illustrated) through the machine. The workpiece 1 is contacting with its right machined longitudinal side this fence which is fixed on the machine and which forms the vertical contact plane and reference plane.

In transport direction downstream of the left vertical spindle, the machine is provided with a horizontal top spindle on which the tool 10 is seated. The top side of the workpiece 1 is machined by it as the workpiece 1 passes through the machine.

In the embodiment according to FIG. 1, a second top tool 11 is provided at a spacing downstream of the top tool 10 and is driven in rotation about a horizontal axis.

At a spacing downstream of the horizontal top tool 11 a horizontal bottom spindle is provided on which a tool 12 is fixedly seated with which the bottom side of the workpiece 1 can be machined.

The workpiece 1 after its machining exits through outlet opening 13 from the machine.

During machining of the workpieces 1, the machine chamber is closed by a machine cover 14.

In the illustrated exemplary moulder, in the area between the two top tools 10, 11 a horizontal bottom table roller 15 is provided. A further horizontal bottom table roller 16 is provided at the level of the outlet opening 13. The machine table 9 is interrupted for the two parallel oriented horizontal rollers 15, 16 as well as the bottom tools 6, 12 so that machining of the workpiece bottom side by means of the tools is possible.

Based on the illustrated embodiment, in the following it will be described how a contour is milled on the longitudinal side of the workpiece 1 to the left in transport direction. For this purpose, it is required that the position of the workpiece 1 in the machine can be detected at all times. For this purpose, in the transport direction of the workpiece 1 upstream of the left tool 8 a first measuring roller 17 is provided (FIG. 3) which is freely rotatably supported about vertical axis 18. The measuring roller 17 is located at the lower end of the vertical measuring roller support 19 which is received in a holder 20. The holder 20 is located at the free end of a support arm 21 which is supported so as to be slidable in its longitudinal direction in a holder tube 22. The latter is arranged in a suitable way fixedly on the machine. The support arm 21 is axially loaded by an axial force so that the measuring roller 17 is forced against the longitudinal side 23 of the workpiece 1 to the left in the transport direction. The support arm 21 can be subjected to a spring force or to pneumatic/hydraulic pressure. In this way, it is ensured that the measuring roller 17 is pressed reliably against the longitudinal side 23 of the workpiece 1. Upon movement of the workpiece 1, the measuring roller 17 is reliably rotated by the workpiece so that the position of the workpiece 1 is reliably detected.

A rotary encoder 24 is fixedly connected to the measuring roller 17 and is provided at the upper end of the measuring roller support 19 and supplies rotary encoder signals to the machine control unit by means of a data line 25.

Since with the left vertical tool 8 the contour is generated on the left longitudinal side 23 of the workpiece 1 and since the measuring roller 17 in transport direction is upstream of the tool 8, the position of the workpiece 1 can be properly detected.

In order to detect the leading end of the workpiece 1 and thus its exact position in the machine, a light barrier 26 is provided in transport direction upstream of the left vertical tool 8. It is located in the area between the tool 8 and the measuring roller 17. When the light barrier 26 is interrupted by the leading end of the workpiece 1, the sensor of the light barrier 26 sends a signal to the machine control unit. This represents the starting point of the positional measurement by means of the measuring roller 17.

The sensor for detecting the leading end of the workpiece is not limited to a light barrier 26 but can be any type of sensing means capable of detecting the leading end of the workpiece, in particular of a workpiece of wood, with the required precision and speed upon its transport through the machine.

The first measuring roller 17 and the light barrier 26 can also be arranged in transport direction of the workpiece 1 upstream of the right tool 7 or even upstream of the top tool 10 or 11, depending on which tool or tools are to be used for machining a contour on the workpiece. Then also, as soon as the leading end of the workpiece has interrupted the light barrier 26, a start signal is generated for the position measurement by means of the measuring roller 17.

FIGS. 1 and 2 show the possibility that a further measuring roller 17 is not contacting the longitudinal side 23 of the workpiece 1 that is to be contoured but is contacting its top side 27. Since in the embodiment the workpiece top side 27 is not to be provided with a contour, the position of the workpiece 1 in the machine can be precisely detected also by means of the measuring roller 17. The measuring roller 17 in this case is freely rotatable about a horizontal axis. It is forced by means of the force-loaded support arm 21 in the described way strongly against the workpiece top side 27. The configuration of the measuring arrangement corresponds to the described embodiment with the measuring roller 17 rotatable about the vertical axis 18.

For travel detection by means of measuring rollers, a measuring roller 17 must always contact the workpiece 1. First, this is done upstream of the tool 8 because a measuring roller downstream of the tool 8 can not yet detect the workpiece 1 and therefore no travel measurement is possible. Once the workpiece 1 has left the measuring roller 17 upstream of the tool 8, this measuring roller can no longer provide signals and the travel detection must be realized by means of the measuring roller 17 downstream of the tool 8.

By a sensor 38 on the measuring roller 17 it is detected when the measuring roller 17 is contacting the workpiece 1 because, when the measuring roller 17 contacts the workpiece 1, the support arm 21 in the holding tube 22 is axially adjusted and thereby the sensor 38 is actuated.

For travel detection, a measuring roller 17 which is contacting the workpiece 1 is thus always utilized, wherein by means of the control unit it is determined when which one of measuring rollers 17 is to be used for the travel detection. Therefore, essentially a cascading utilization of the measuring rollers 17 occurs wherein however the travel measurement of the downstream measuring roller 17 is based on that of the preceding one, respectively.

In the embodiment according to FIG. 1, the further measuring roller 17 in transport direction of the workpiece 1 is arranged downstream of the top tool 10. The arrangement of the measuring roller 17 depends on the machining tasks and on which tools are to be used for this purpose. In this context, it is necessary to flexibly bring into action and evaluate the measuring rollers 17 depending on the machining task.

In the illustrated example, the two measuring rollers 17 upstream and downstream of the tool 8 are used.

The travel detection of the workpieces 1 can of course be performed also by other known measures. For example, the travel detection of the workpiece 1 can be realized directly by means of the advancing drive of the machine. In this context, the rotary speed of the drive, of the drive shaft, or of the transport rollers is detected, based on the effective diameter of the transport rollers, is converted to the travel of the workpiece 1 through the machine.

Moreover, a travel detection is also possible by optical sensors which operate contactless and are used instead of the measuring rollers 17 and can be arranged in the same way as the latter in the machine.

The path of the workpieces 1 through the machine can also be detected by cameras in the machine chamber. The camera sends corresponding signals to the machine control unit which evaluates the camera signals and utilizes them for position detection of the workpieces.

The travel detection can also be realized by means of a distance measurement by means of laser on the end face of the workpiece 1.

Furthermore, for example, the use of a linear scale on magnetic basis parallel to the advancing direction is possible for the travel detection. In this case, in the workpiece 1 to be machined magnets are provided. Also, the use of transponders in the workpieces is possible. Also, a linear scale as an incremental scale with correlated transducer in the workpiece or the like can be employed.

A further possibility of travel detection resides in that the workpieces 1 are transported by means of chains. The use of chains has the advantage that no or hardly any slip between the workpiece 1 and the chain occurs. In this way, the chain travel or the chain speed is used for determining the position of the workpiece 1 in the machine.

Finally, it is also possible to transport the workpieces, for example, by means of chains, bands, belts, or linear units that have projecting fingers with which the workpieces are held with form fit or pushed with form fit through the machine. In this case, the travel of the fingers can be detected and can be utilized for positional determination of the workpiece 1 in the machine.

In the illustrated example, the workpiece 1 at its longitudinal side 23 is provided with a contour 28, as it is illustrated in FIG. 4. This contour 28 is produced by the tool 8 that is arranged on the vertical left spindle of the moulder. The top side 27, the bottom side 29, and the two end faces 30, 31 of the workpiece 1 remain free of contours. During throughfeed of the workpiece 1 through the machine, the workpiece is contacting with its longitudinal side 32 to the right in the transport direction the edge jointing fence 4, or the fence which is not illustrated.

The spindle supporting the tool 8 is adjustable in Y direction (FIG. 2) and thus perpendicular to the X direction. The X direction is the throughfeed direction (transport direction) of the workpiece 1 through the machine.

The spindle of the right tool 8 is connected with an adjusting unit 33 which is only schematically illustrated. The adjusting unit 33 is designed such that it can quickly and position-precisely adjust the tool 8 in Y direction into the position required for contour milling. Preferably, the adjusting unit 33 is embodied as a linear motor which is suitable particularly to move the tool 8 quickly and with high positioning precision into the desired position. The clearance-free design and high stiffness that distinguishes the linear motor contributes to this. It is therefore possible to adjust the tool 8 exactly into the position required for contour milling of the workpiece 1.

As an adjusting unit 33, also a ball screw drive is conceivable. The latter can also adjust the tool 8 with high precision and quickly into the desired position in Y direction.

In principle, all drive systems are conceivable that are at least low clearance, advantageously are free of clearance, and have such a stiffness that in particular for movement reversal of the adjusting unit the required precision and surface quality can be achieved. In this context, in particular also the dynamics and the masses to be moved of adjusting unit, spindle receptacle, spindle, and tool are to be taken into account. For the geometry precision or geometry trueness, the positioning precision of the adjusting unit 33 is decisive in essence. For the uniformity of the planer mark of the tool, the stiffness and the clearance of the adjusting unit are decisive. The stiffness influences in particular the hysteresis at the reversing points of the adjusting unit. The stiffness as well as low clearance or clearance-free design of the adjusting unit 33 are so good that the uniformity of the planing marks on the end product is not visibly impaired in particular at the reversing points or reversing areas of the adjusting unit 33. When it is assumed that the depth of the planer marks is within a single-digit micrometer range and a knife impact depth on the end product becomes noticeable from approximately 10 μm on, the hysteresis and the clearance of the adjusting unit 33 amount also to only a few micrometers.

The respective drive is linked by means of the machine control unit in such a way to the transport speed of the workpiece 1 through the machine that the adjustment of the adjusting unit 33 in Y direction is coupled to the advancing speed of the workpiece 1 through the machine or its advancing travel. Through the data line 25, the measuring rollers 17 provide the corresponding travel signals to the control unit of the machine where the signals are processed/evaluated.

The adjusting unit 33 can be used as an auxiliary attachment device with which it is possible to retrofit moulders with an adjusting unit so that contour milling of the workpieces is also possible with the moulders.

Since by means of the tool 8 the contour 28 is provided on the longitudinal side 23 of the workpiece 1 to the left in the throughfeed direction through the machine, the adjusting unit 33 is provided on the moulder such that the tool 8 can be adjusted in Y direction relative to the workpiece 1.

Depending on which side of the workpiece 1 is to be provided with the contour, the adjusting unit 33 can be arranged on the moulder such that the contour can be provided not only on the left longitudinal side 23 but also on the right longitudinal side 32 of the workpiece 1. It is even possible to provide at the same time both longitudinal sides 23, 32 of the workpiece 1 with a contour by means of the tools 7 and 8. In this case, the spindles of the two tools 7, 8 are coupled with one adjusting unit 33 each, respectively.

The contours on the workpiece can be provided not only at one or at both longitudinal sides 23, 32 of the workpiece 1 but also, for example, on its top side 27 and/or its bottom side 29. In this case, for example, the horizontal top tool 10 and the downstream horizontal bottom tool 15 are adjusted in Z direction by means of the adjusting unit 33. In this case, the Z adjustment is also coupled to the advance of the workpiece 1 in X direction so that the contour at the top side and/or bottom side of the workpiece 1 can be manufactured with the required high precision.

In this alternative embodiment, the measuring rollers 17 are always contacting the workpiece side that is not to be provided with a contour.

The adjusting unit 33 can also be designed such that it not only can adjust the corresponding tool in a linear direction but also within a plane. Thus, it is possible in the illustrated embodiment to design the adjusting unit 33 such that the tool 8 is adjustable in the X-Y plane. This can be achieved, for example, by designing the adjusting unit 33 in the form of a compound slide carriage whose two carriage parts independent of each other can be adjusted in X direction and in Y direction. With the two carriage parts, it is then possible to adjust the tool 8 within the X-Y plane in any desired direction.

Accordingly, the desired contours can be milled also on the end faces 30, 31 of the workpiece 1 with the tool 8. The adjusting speed can be synchronized in X direction with the advance wherein then, upon adjusting the tool 8 in Y direction, an end face machining at a right angle to the longitudinal side 23 is carried out. Other angle positions and end face contours are possible by a corresponding control of the X movement and Y movement of the tool 8 by means of the adjusting unit 33.

FIG. 4 shows a machine in which instead of the horizontal tool 10 a device 34 is provided. It has a vertical tool 35 with which bores 36 (FIG. 5) or slotted holes 37 can be produced in the workpiece 1. The device 34 is moved along during production of the bores 36 or the slotted holes 37 in X direction with the workpiece 1 at the same advancing speed. In other respects, the machine is of the same configuration as the preceding embodiment.

When producing the bore 36, the device 34 moves relative to the workpiece 1 in Z direction. When the slotted hole 37 is produced, the device 34 moves in addition also in X direction or Y direction relative to the workpiece 1. Since the slotted hole 37 in the embodiment is positioned at a slant to the X direction, the device 34, after feeding in Z direction, is moved within the X-Y plane.

The tool 35 of the device 34 can be a drill or an end mill tool. The device 34, for example, is a milling device that is acting from above on the workpiece 1. The device 34 can also be arranged in transport direction (X direction) on the left or right side. Then, the bores 36 and/or the slotted holes 37 not only can be provided at the top side 27 but also in the left and/or right longitudinal side of the workpiece 1.

As shown in FIG. 4, it is advantageously provided that the device 34 is also movable about the X axis and/or about the Y axis. Therefore, the slotted holes 37 as well as the bores 36 can be introduced at different angles into the workpiece 1.

It is furthermore possible to provide and arrange the adjusting unit 33 such that the corresponding tool is adjustable by it in an X-Z plane or in a Y-Z plane.

It is finally possible to designed the adjusting unit 33 such that the corresponding tool within the X-Y-Z space can be adjusted at will. In this case, the adjusting unit 33 also has an adjusting component in the Z direction.

The spindle for the tool 8 for milling the contour can also be pivotable about an axis B which is positioned in the X direction (FIG. 2). This corresponds to the function of a universal spindle of a conventional moulder. It is then possible to mill on the workpieces 1 contours that are not rectangular but are positioned at a slant to the top or bottom sides 27, 29 of the workpiece 1. In particular, in such a case a slant of the tool 8 can be changed as the workpiece 1 passes through the machine so that the angular position of the contour changes across the length of the workpiece.

Due to the adjustment of the tool 8 in radial direction (Y direction) and axial direction (Z direction) and pivoting about the X axis in combination with the advancing movement of the workpiece 1 (X direction), a four-axis machining in throughfeed is possible in a moulder for the first time.

In these variants, the adjusting unit 33 is also always embodied such that the corresponding tool can be adjusted quickly and with precise positioning in the required position relative to the workpiece 1.

In the described variants, it is also possible to provide more than one adjusting unit 33 so that the workpiece 1 can be processed at several sides.

With the respective adjusting unit 33, the corresponding tool can be adjusted into any position upon throughfeed of the workpiece 1. In this way, freely programmable contours can be provided on the workpiece. These contours can be provided on all sides of the workpiece 1. For this purpose, the corresponding tools are adjustable with an adjusting unit 33, respectively. Since the workpieces 1 are machined by a throughfeed process and the adjusting unit 33 enables a quick but still position-precise adjustment of the tool, very high productivity rates are realized. For contour milling of the workpieces 1 only one machine is required with which the workpieces 1 can be machined in different ways.

For example, the top and bottom sides 27, 29 and the longitudinal side 32 can be planed straight and the longitudinal side 23 can be provided with the contour 28. Furthermore it is possible to provide, for example, the longitudinal side 23 with the contour 28 and to introduce on at least one other side a profile into the workpiece 1. Accordingly, profiling tools are provided on the corresponding spindles. The contour as well as the profiles are then produced on the workpiece 1 in one pass through the machine. Therefore, a plurality of working processes are combined in a machine which enables very short throughfeed times. The space requirement is also minimal because it is not necessary to provide different processing machines for the different types of workpiece machining. Storage for intermediately storing workpieces between the individual machining steps is eliminated. Also, transport damages which can result from intermediate storage and removal and feeding of the workpieces to different processing machines are avoided.

With the adjustable tools with which the contour on the workpiece 1 is generated, high surface qualities can be achieved. With the machine, a surface in furniture quality, i.e., with so-called finish quality, is produced on the workpiece. In this way, post-machining of the contoured end products is not required. The machined end products which are leaving the machine can therefore be immediately applied to their intended use. With the adjusting units 33, the tools can be highly precisely adjusted in the described way so that on the finish machined workpiece a high geometry precision with high surface quality is ensured.

The workpieces can be positioned end-to-end, i.e., contacting each other in longitudinal direction, or can be conveyed individually through the machine and machined. In end-to-end machining, a sensor is advantageously employed which detects the respective leading end of the workpiece.

Not only workpieces 1 of wood but also workpieces of other materials can be machined. For example, the workpieces can be comprised of plastic material, aluminum, and the like.

With the machine it is possible for the first time to provide workpieces 1 with any contour in a throughfeed-operated profiling machine with the adjusting unit 33. In particular the use of a linear motor as an adjusting unit 33 makes it possible to mill with high precision the desired contours on the workpiece 1. The machine enables the user to produce such contoured workpieces with high surface quality in finish quality and high precision. Also, the machine enables a high efficiency. With the machine it is possible for the customer to optionally only plane straight the workpieces 1 on all four sides, wherein an adjustment of at least one of the tools during throughfeed is not performed. Furthermore, at least on one side of the workpiece 1, a contour can be milled while at least on one additional side only planing straight and/or profiling is performed.

For producing a contour on a workpiece, an NC program is first generated, based on a workpiece drawing with the desired contouring. The geometry of this contour can be freely programmed. The NC program generation or the NC code generation is advantageously performed in an automated process. The NC program is then transferred to the machine control unit of the machine and is executed when machining the workpieces 1, advantageously in a process that is repeated for each workpiece. The machine is a throughfeed machine in the form of a moulder which is provided with the auxiliary device in the form of the adjusting unit 33. The latter is provided for those spindles with which the contours 28 on the workpiece 1 are to be generated. The machine has also a detection system in order to detect the position of the workpieces 1 as the workpieces pass through the machine. Depending on the contour 28 to be produced, the machine has special guiding and holding elements in order to convey the workpieces 1 exactly, vibration-free, and free of clearance through the machine.

The specification incorporates by reference the entire disclosure of German priority document 10 2016 013 408.9 having a filing date of 4 Nov. 2016.

While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

1. A machine for machining workpieces of wood, plastic material, and the like, the machine comprising:

at least one transport path for workpieces on which the workpieces, during throughfeed of the workpieces through the machine, are transported in a throughfeed direction through the machine;
tools fixedly seated on spindles and configured to machine the workpieces during throughfeed of the workpieces through the machine on the at least one transport path;
an adjusting unit having a first adjusting axis;
wherein at least one of the spindles is coupled with the adjusting unit;
wherein the adjusting unit is configured to perform an adjustment of the at least one spindle, for producing a contour on the workpieces, in a direction transverse to the throughfeed direction during throughfeed of the workpieces through the machine, wherein the adjustment is carried out as function of an advancing speed of the workpieces and/or workpiece positions of the workpieces along the at least one transport path during throughfeed;
wherein the adjusting unit has such a stiffness and/or low clearance and/or positioning precision that end products machined from the workpieces, when exiting from the machine, can be used without further post-machining.

2. The machine according to claim 1, wherein a rotary speed of the at least one spindle is adjustable at all times during throughfeed of the workpieces through the machine as a function of the advancing speed and the contour of the workpieces such that a knife mark of the tool fixedly seated on the at least one spindle is maintained constant.

3. The machine according to claim 1, wherein the adjusting unit is free of clearance.

4. The machine according to claim 1, wherein the adjusting unit is a linear drive.

5. The machine according to claim 1, wherein the adjusting unit is a ball screw drive.

6. The machine according to claim 1, wherein the adjusting unit has a second adjusting axis.

7. The machine according to claim 6, wherein the first and second adjusting axes of the adjusting unit are positioned at a right angle relative to each other.

8. The machine according to claim 1, further comprising at least one measuring device configured to detect the workpiece positions in the machine

9. The machine according to claim 8, wherein the at least one measuring device comprises a measuring roller that is contacting a side of the workpieces not to be machined with a contour.

10. The machine according to claim 9, further comprising a machine control unit, wherein the at least one measuring device comprises a rotary encoder that detects a rotation of the measuring roller and sends corresponding detection signals to the machine control unit.

11. The machine according to claim 10, wherein an adjusting speed or an adjusting movement of the adjustment of the adjusting unit is coupled by the machine control unit with the advancing speed of the workpieces in the machine or the advancing travel of the workpieces in the machine and thereby with the workpiece positions in the machine during throughfeed of the workpieces.

12. The machine according to claim 1, wherein the adjusting unit is a device connectable to the machine.

13. The machine according to claim 1, wherein the machine is a moulder.

14. A method for machining workpieces of wood, plastic material, and the like, with a machine according to claim 1, the method comprising:

generating an NC program for a machine control unit of the machine based on a desired and freely selectable geometry or contour;
executing the NC program during throughfeed of the workpieces through the machine and repeating the NC program for each one of the workpieces;
detecting a travel or a position of the workpieces during throughfeed of the workpieces through the machine;
moving at least one contour producing tool transverse to a throughfeed direction of the workpieces through the machine with at least one adjusting unit as a function of a desired contour of the workpieces, of tool data, and of the workpiece positions;
wherein the adjusting unit has such a stiffness and/or low clearance and/or positioning precision that the finish machined workpieces, when exiting from the machine, have such a geometry precision and surface quality that the finish machined workpieces can be used without further post-machining.
Patent History
Publication number: 20180126511
Type: Application
Filed: Oct 12, 2017
Publication Date: May 10, 2018
Inventors: Albrecht Dawidziak (Großrinderfeld), Benjamin Frank (Boxberg), Christian Burger (Tauberbischofsheim)
Application Number: 15/730,786
Classifications
International Classification: B24B 9/00 (20060101); B24B 9/18 (20060101); B24B 9/20 (20060101); B24B 19/24 (20060101); B24B 41/04 (20060101); B24B 49/00 (20060101); B24B 35/00 (20060101);