LOADER WORK MACHINE

Abstract

A loader work machine has a base frame including a cabin; a loader work apparatus attached to the base frame; and two traveling apparatuses supporting the base frame, and including: a track frame connected to the base frame; a drive wheel driving a traveling belt; front and rear idlers arranged in a front-back direction below the drive wheel and supported by the track frame; and one or more track rollers arranged between the front and rear idlers and supported by the track frame, the traveling belt stretched around the drive wheel, idlers, and track rollers. The base frame includes: a lower frame connected to two track frames and interposed between the traveling apparatuses; an upper frame provided with the loader work apparatus; and a slewing apparatus connecting the upper and lower frames. The upper frame connected to the lower at an upper frame bottom surface being above the traveling belts.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a loader work machine.

Description of the Related Art

For example, as illustrated in FIG. 6, a known conventional loader work machine (track loader) includes: a pair of traveling apparatuses 201; a base frame 202 that is supported by the traveling apparatuses 201 and includes a cabin 202A and an engine room 202B in an upper part of the base frame 202; booms 203 that are each attached to the base frame 202 via a lift link 204 and have leading ends to which a bucket 206 is provided; and boom cylinders 205 that respectively move the booms 203 up/down with respect to the base frame 202.

Crawler traveling apparatuses each having a substantially triangular rice ball shape are frequently used for such a loader work machine in order to enhance the traveling performance. Moreover, the center of gravity of such a loader work machine is lowered in order to enhance the traveling performance. Hence, the base frame is sandwiched between the pair of traveling apparatuses,

Such a loader work machine as described above can insert a work tool such as the bucket located in a front part of the loader work machine, into a piled-up object such as piled-up earth, sand, and rubble or into the ground, using a thrust generated by forward movement of the traveling apparatuses, and thus can pick up a transportation target object such as earth and sand to be transported. Then, the loader work machine can move and unload the transportation target object to a desired unloading place, or can load the transportation target object onto a transporting vehicle such as a dump truck (see, for example, U.S. Pat. No. 8,342,789).

Because the loader work machine described in U.S. Pat. No. 8,342,789 has the above-mentioned configuration, the work tool is fixed to the direction in which the base frame faces. Hence, in the case where the transportation target object being transported by the work tool is unloaded to a desired place, it is necessary to change the direction of the loader work machine itself such that the front side of the loader work machine faces the place, while the loader work machine is caused to travel. Moreover, such a work process is normally repeated several times in many cases.

As a result, the operating time of the traveling apparatuses becomes longer, so that the product lifetime of the traveling apparatuses becomes shorter. Accordingly, there is a problem that the running cost of the loader work machine becomes higher.

The present invention, which has been made in view of the above-mentioned problem, has an object to provide a loader work machine that can improve the product lifetime of traveling apparatuses to thereby reduce running cost.

SUMMARY OF THE INVENTION

In order to achieve the above-mentioned object, a loader work machine reflecting one aspect of the present invention includes a base frame including a cabin; a loader work apparatus attached to the base frame; and a pair of traveling apparatuses that support the base frame. The traveling apparatuses each include: a track frame connected to the base frame; a drive wheel that rotationally drives a traveling belt; a front idler and a rear idler that are arranged in a front-back direction below the drive wheel and are rotatably supported by the track frame; and one or more track rollers that are arranged between the front idler and the rear idler and are rotatably supported by the track frame, the traveling belt being stretched around the drive wheel, the front idler, the rear idler, and the track rollers. The base frame includes: a lower frame that is connected to a pair of the track frames and is interposed between the pair of traveling apparatuses; an upper frame that is provided with the loader work apparatus and is arranged above the lower frame; and a slewing apparatus that slewably connects the upper frame to the lower frame. The upper frame is connected to the lower frame at a position at which a bottom surface of the upper frame is above the traveling belts.

More preferably, the slewing apparatus includes a slewing bearing, and is capable of slewing the upper frame 360 degrees with respect to the lower frame.

More preferably, the loader work apparatus includes: a pair of right and left booms supported by the base frame; a work tool provided to leading ends of the pair of booms; and a swinging apparatus capable of swinging the pair of booms in a top-bottom direction, and the loader work apparatus further includes a moving apparatus capable of moving the pair of booms forward.

More preferably, the moving apparatus includes: movement cylinders that are supported by the base frame and are each made of a hydraulic cylinder; and link members that are turnably supported by the base frame and each have one end connected to each of the movement cylinders and another end connected to each of the pair of booms, the swinging apparatus includes boom cylinders that are supported by the base frame and are each made of a hydraulic cylinder, and the pair of booms are made movable forward by respectively driving the link members by the movement cylinders in a state where the pair of booms are respectively supported by the boom cylinders.

According to the present invention, it is possible to provide a loader work machine that can improve the product lifetime of traveling apparatuses to thereby reduce running cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a track loader according to the present embodiment;

FIG. 2 is an enlarged cross-sectional view taken along A-A in FIG. 1;

FIG. 3 is a side view illustrating the state where the track loader according to the present embodiment is inclined;

FIG. 4A is a diagram for describing an operation of unloading a transportation target object by a conventional track loader;

FIG. 4B is a diagram for describing an operation of unloading a transportation target object by the track loader according to the present embodiment;

FIG. 5 is a partial enlarged view illustrating a modified example of a loader work apparatus; and

FIG. 6 is a side view illustrating an example conventional track loader.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, a track loader as a loader work machine according to an embodiment of the present invention is described with reference to the drawings. The scope of the present invention is not limited to examples illustrated in the drawings. Note that, in the following description, elements having the same functions and configurations are denoted by the same reference signs, and description thereof is omitted.

Before the track loader according to the present embodiment is described, an example conventional track loader is first described with reference to FIG. 6. FIG.. 6 is a side view illustrating the example conventional track loader. In the following description, the top-bottom, the right-left, and the front-back respectively mean the top-bottom, the right-left, and the front-back based on the direction of eyes of an operator who gets in and drives the track loader.

As illustrated in FIG. 6, a conventional track loader 200 includes, for example, traveling apparatuses 201, a base frame 202, booms 203, lift links 204, boom cylinders 205, and a bucket 206.

One traveling apparatus 201 is attached on each of the right and left sides of the base frame 202, and the two traveling apparatuses 201 support the base frame 202. Each traveling apparatus 201 includes, for example, a track frame 201a, a sprocket 201b, a front idler 201c, a rear idler 201d, four track rollers 201e, and a rubber track 201f.

The track frame 201a is a member having an inverted U shape in cross-section extending in the front-back direction, and is attached to the base frame 202. The track frame 201a rotatably supports the front idler 201c, the rear idler 201d, and the track rollers 201e. The sprocket 201b is arranged above the track frame 201a, and the sprocket 201b is rotatably supported by the track frame 201a via a support member 201g.

The sprocket 201b is formed in a discoid shape, and is attached to a slightly back part from the center of the base frame 202. Countless teeth are formed on the outer circumference of the sprocket 201b. The center of the sprocket 201h is borne by a drive shaft 201h that transmits driving force from an engine, whereby the sprocket 201h can rotate about the drive shaft 201h in accordance with the driving force from the engine. The sprocket 201b rotates while the countless teeth formed on the outer circumference thereof are meshed with sprocket holes that are formed at predetermined intervals on the inner circumference of the rubber track 201f, whereby the sprocket 201b can rotationally drive the rubber track 201f. That is, the sprocket 201b functions as a drive wheel that rotationally drives the rubber track 201f,

The front idler 201c is rotatably supported by a leading end portion of the track frame 201a via a tensioner (not illustrated). The tensioner gives pressing force to the front idler 201c, and adjusts the tension of the rubber track 201f to a constant value. The rear idler 201d is rotatably supported by a back end portion of the track frame 201a. The four track rollers 201e are arranged at regular intervals in the front-back direction between the front idler 201c and the rear idler 201d, and are rotatably supported by the track frame 201a. The front idler 201c, the rear idler 201d, and the track rollers 201e function as idler wheels. Note that, although the four track rollers 201e are provided in the present embodiment, the number of the track rollers 201e is not limited thereto, and can be set to an appropriate number. Moreover, the track rollers 201e may not be Provided.

The rubber track 201f is made of a plastic material such as rubber, and is a belt member formed in an endless belt shape. As described above, the sprocket holes are formed at predetermined intervals in the center of the inner circumference of the rubber track 201f, and the teeth of the sprocket 201b can be inserted into and removed from the sprocket holes. The intervals of the sprocket holes are coincident with pitches of the teeth of the sprocket 201b. The outer circumference of the rubber track 201f is a tread, and patterns for increasing driving force and braking force are formed on the outer circumference thereof. The rubber track 201f thus formed is rotatably attached by the sprocket 201b, the front idler 201c, the rear idler 201d, and the track rollers 201e.

Because each traveling apparatus 201 is configured as described above, the traveling apparatus 201 has a substantially triangular rice ball shape protruding upward. As a result, the sprocket 201b is at a position away from a ground contact surface, and hence a foreign substance such as a pebble can be prevented from being caught in the sprocket 201b to cause a trouble at the time of traveling,

The base frame 202 includes a cabin 202A and an engine room 202B in an upper part of the base frame 202. The cabin 202A. is surrounded by, for example, a front window, an entrance/exit door, side windows, and a rear window, and is provided with a driver's seat, a steering handle, a transmission, and the like inside thereof. The operator can get in the cabin 202A by opening/closing the entrance/exit, door. The engine room 202E houses, for example, the engine for driving the track loader 200 to travel.

The booms 203 are arranged in a pair on the right and left sides of the base frame 202 so as to sandwich the base frame 202, and each have a back end part that is attached to the base frame 202 via the lift link 204, whereby the booms 203 are swingable in the top-bottom direction. The bucket 206 as a work tool is attached to the leading ends of the pair of booms 203. The bucket 206 is formed in a concave shape so as to be capable of housing earth, sand, and rubble. The bucket 206 is made turnable by, for example, bucket cylinders (not illustrated) in the top-bottom direction in a range indicated by an arrow M2, and can unload (dump) a transportation target object such as earth, sand, and rubble housed in the bucket 206. Each lift link 204 has: a base end part turnably supported by a substantially central part of the base frame 202; and a leading end part turnably supported by a back end part of each boom 203. Each boom cylinder 205 is made of a hydraulic cylinder, and is capable of moving a rod forward/backward using a hydraulic pressure. The boom cylinders 205 are provided in a pair on the right and left sides of the base frame 202 so as to sandwich the base frame 202. The pair of boom cylinders 205 each include: a cylinder part having a base part turnably attached to a side surface of the base frame 202; and the rod having a leading end part turnably attached to each boom 203. The attachment position of the leading end part of the rod of each boom cylinder 205 is on the leading end side from the attachment position of each lift link 204 in each boom 203.

In the track loader 200 configured as described above, when each boom cylinder 205 is driven to be elongated, each lift link 204 turns about the base end part thereof supported by the base frame 202 as a turn supporting axis. Consequently, the leading end part of each lift link 204 (that is, the back end part of each boom 203) moves along a trajectory indicated by an alternate long and short dash line L. Then, each boom 203 can be swung upward along with the elongation of each boom cylinder 205 to be moved from a position indicated by X2 to a position indicated by Y2. In this way, the booms 203, the lift links 204, the boom cylinders 205, and the bucket 206 constitute a loader work apparatus.

While being moved forward by the traveling apparatuses 201, the track loader 200 configured as described above can insert the bucket 206 into a piled-up object such as piled-up earth, sand, and rubble or into the ground, using a thrust generated by the forward movement, and thus can pick up a transportation target object such as earth and sand to be transported. Then, the track loader 200 can travel with the transportation target object being housed in the bucket 206, can move and unload the transportation target object to a desired unloading place, or can load the transportation target object onto a transporting vehicle such as a dump truck. Moreover, the track loader 200 can perform ground leveling work by moving backward while bringing the bottom surface of the bucket 206 into contact with a ground surface to be leveled.

Because the track loader 200 is configured as described above, the track loader 200 has a low center of gravity, and is excellent in traveling stability. Moreover, because the track loader 200 includes the traveling apparatuses 201 configured as described above, the track loader 200 is excellent in traveling performance. In the track loader 200 described above, however, the base frame 202 is arranged so as to be sandwiched between the pair of traveling apparatuses 201, and hence, in the case of changing the direction of the bucket 206, it is necessary to drive the traveling apparatuses 201 and change the direction of the track loader 200 itself, so that wasting of the traveling apparatuses 201 is large.

In view of the above-mentioned problem, the track loader according to the present embodiment can reduce such wasting of the traveling apparatuses in the following manner,

Next, the track loader according to the present embodiment is described with reference to FIG. 1 to FIG. 3, FIG. 1 is a side view of a track loader 100 according to the present embodiment. FIG. 2 is a cross-sectional view that is taken in an arrow direction along a line A-A in FIG, 1, and is an enlarged cross-sectional view of a portion of a lower frame 103. FIG. 3 is a side view illustrating the state where the track loader 100 according to the present embodiment is inclined backward.

As illustrated in FIG. 1, the track loader 100 according to the present embodiment includes, for example, traveling apparatuses 101 and a base frame 102. The traveling apparatuses 101 have a configuration similar to that of the traveling apparatuses 201 in the conventional track loader 200 described with reference to FIG. 6. Accordingly, detailed description of the traveling apparatuses 101 is omitted.

The base frame 102 includes the lower frame 103 and an upper frame 104. The upper frame 104 is arranged above the lower frame 103, and is connected to the lower frame 103 via a slewing bearing 105. The upper frame 104 can be stewed by driving the slewing bearing 105.

As illustrated in FIG. 1 and FIG. 2, the lower frame 103 includes a link frame 103A, a support plate 103B, and a connection part 103C. The link frame 103A has both ends inclined downward, and is bent in a concave shape. Both the ends of the link frame 103A are respectively connected to track frames 101a of the traveling apparatuses 101. As illustrated in FIG. 1, the link frame 103A extends to a position at which the link frame 103A protrudes more forward than the leading ends of the traveling apparatuses 101. The connection part 103C is provided in a back center part of the link frame 103A, and the support plate 103B is connected to the back center part thereof via the connection part 103C.

The slewing bearing 105 is attached to the upper surface of the support plate 103B. More specifically, the slewing bearing 105 is a conventional slewing bearing including, for example, an outer ring 105a, an inner ring 105b, a pinion gear (not illustrated) that is meshed with a gear formed on the inner circumference of the inner ring, and a hydraulic swing motor (not illustrated) that rotates the pinion gear. Moreover, a swivel joint (not illustrated) is arranged in the center of the slewing bearing 105. The swing motor is connected to the swivel joint by a hydraulic hose, and operating oil is supplied to the swing motor via the swivel joint. The outer ring 105a and the swing motor are attached to the upper frame 104, and the inner ring 105b is attached to the support plate 103B. Accordingly, when the pinion gear is rotated by driving the swing motor, the outer ring 105a attached to the upper frame 104 slides on the inner ring 105b in accordance with the rotational movement of the pinion gear along the inner circumference of the inner ring 105b, and the upper frame 104 slews about an axis R. (that is, the center of rotation of the slewing bearing 105) as an axis of rotation. With this structure, the upper frame 104 can slew 360 degrees can do a full circle). Note that the slewable angle of the upper frame 104 may not be set to 360 degrees, and may be restricted to a given angle range (for example, 180 degrees). Moreover, although the slewing bearing 105 is used as means for stewing the upper frame 104, another apparatus may be adopted as long as the apparatus can slew the upper frame 104. A conceivable example of the other apparatus is an apparatus in which the upper frame 104 is connected to the axis of rotation and the upper frame 104 is slewed by rotations of the axis of rotation.

Here, the upper frame 104 is connected to the lower frame 103 via the stewing bearing 105, at a position at which the bottom surface of the upper frame 104 is above rubber tracks of the traveling apparatuses 101. In the present embodiment, for example, as illustrated in FIG. 2, a gap G is provided between the highest position of the rubber tracks and the bottom surface of the upper frame 104. Note that, in FIG. 1 and FIG. 2, the height from a ground contact surface of the rubber tracks to the highest position of the rubber tracks is indicated by an arrow H. In the present embodiment, the size of the gap G is set to, for example, 47 mm. The size of the gap G can be set as appropriate as long as the rubber tracks do not interfere with the upper frame 104 when the upper frame 104 slews. As the size of the gap G is set to be smaller, the total height can be suppressed to be smaller. Hence, the center of gravity becomes lower, and the traveling stability can be more enhanced, which is preferable.

As illustrated in FIG. 1 to FIG, 3, the connection part 103C is a structure having a predetermined height, and includes a tilting apparatus 106 and spacers 106a. In the present embodiment, the connection part 103C has the predetermined height in order to arrange the bottom surface of the upper frame 104 above the rubber tracks of the traveling apparatuses 101. Note that the height of the connection part 103C can be set as appropriate,

The spacers 106a are plate-like members that respectively extend downward from slightly inner positions from the right and left ends of the support plate 103B, and are formed integrally with the support plate 103B. A pair of the spacers 106a each have a back-end lower portion that is partially cut out in a substantially square shape. Lower end parts of the spacers 106a abut against the upper surface of the link frame 103A, whereby the spacers 106a can stably hold the upper frame 104 in a horizontal posture. The pair of spacers 106a each include a rod supporting part 106a1 in the vicinity of the leading end on the outer side surface.

The tilting apparatus 106 includes tilt cylinders 106b, cylinder supporting parts 106c, and spacer supporting parts 106d.

Each tilt cylinder 106b is made of a hydraulic cylinder, and is capable of moving a rod 106b2 forward/backward with respect to a cylinder part 106b1 using a hydraulic pressure. As illustrated in FIG, 2, two tilt cylinders 106b are provided at a predetermined interval on the right and left sides, and are respectively arranged on the outer sides of the spacers 106a. Note that the number of the tilt cylinders 106b may be one and may be three or more. Each cylinder supporting part 106c is a support member that is formed so as to stand from the upper surface in a slightly back part from the center of the link frame 103A, and turnably supports a base end part of the cylinder part 106b1 of each tilt cylinder 106b. The rod supporting part 106a1 of each spacer 106a turnably supports a leading end part of the rod 106b2 of each tilt cylinder 106b.

The spacer supporting parts 106d are provided so as to respectively correspond to the pair of spacers 106a, and are support members that are formed so as to stand from the upper surface in a back end portion of the link frame 103A. Each spacer supporting part 106d has a substantially triangular shape, and has an upper end portion that turnably supports a back end portion of each spacer 106a.

When the tilt cylinders 106h are driven to be elongated, the upper frame 104 turns and tilts about the spacer supporting parts 106d as a turn supporting axis. As a result, the upper frame 104 can turn up to a limit angle θ with respect to the ground contact surface. In the present embodiment, the angle θ is set to 10 degrees, but can be set to an appropriate angle.

In the present embodiment, the upper frame 104 is tilted using the tilt cylinders 106b made of hydraulic cylinders. Alternatively, the upper frame 104 may be tilted using other actuators such as electric motors.

In the upper frame 104, a cabin 104A and an engine room 104B are arranged continuously in the front-back direction. The cabin 104A is surrounded by, for example, a front window, an entrance/exit door, side windows, and a rear window, and is provided with a driver's seat 104f, a steering handle, a transmission, and the like inside thereof. Moreover, in the cabin 104A, a slewing operation and a tilting operation of the upper frame 104 can be performed.

The engine room 104B houses an engine 104a, a radiator 104b, an oil cooler 104c, and an air cleaner 104d, and a muffler 104e for discharging exhaust gas from the engine 104a is attached upward to the engine room 104B.

The engine 104a is an internal combustion engine that evaporates a fossil fuel such as gasoline, combusts the evaporated fuel while mixing the evaporated fuel with air taken in via the air cleaner 104d, and thus can obtain driving force for, for example, causing the track loader 100 to travel. The radiator 104b cools cooling water for cooling the engine 104a. Note that any of a water-cooled radiator and an air-cooled radiator can be adopted as the radiator 104b. The oil cooler 104c cools a lubricant of the engine and the like. Any of a water-cooled cooler and an air-cooled cooler can be adopted as the oil cooler 104c.

Moreover, a loader work apparatus including booms 107, a bucket 108, bucket cylinders 109, and boom cylinders 112 is attached to the upper frame 104 via support plates 113. The support plates 113 are respectively provided to the right and left side surfaces of the upper frame 104. Each support plate 113 has a substantially triangular shape, and has an upper end part in which a boom supporting part 113a is formed; and a front lower part in which a cylinder supporting part 113b is formed.

The booms 107 are arranged in a pair on the right and left sides of the upper frame 104 so as to sandwich the upper frame 104, and each have a base end part supported by the boom supporting part 113a of each support plate 113, whereby the booms 107 are attached turnably in the top-bottom direction. Each boom 107 is formed in a substantially L shape. A rod supporting part 107a is provided to a substantially center lower part of each boom 107. Each boom cylinder 112 is made of a hydraulic cylinder, and is capable of moving a rod 112b forward/backward with respect to a cylinder part 112a using a hydraulic pressure. The boom cylinders 112 are provided so as to respectively correspond to a pair of booms 107. A pair of the boom cylinders 112 each include: the cylinder part 112a having a base part turnably attached to the cylinder supporting part 113b of each support plate 113; and the rod 112b having a leading end part turnably attached to the rod supporting part 107a of each boom 107. Moreover, a cylinder supporting part 107b is provided to the inner side surface of a bent portion of each boom 107, and a bucket turning shaft 107d is provided to a leading end portion of each boom 107. Moreover, each boom 107 includes a stopper 107c at an appropriate position at which the boom 107 abuts against the leading end of the lower frame 103. The stopper 107c is made of, for example, a plastic material such as rubber, and is a member that absorbs a shock when each boom 107 and the lower frame 103 collide against each other.

The bucket 108 as a work tool is supported by the bucket turning shafts 107d respectively provided to the leading ends of the pair of booms 107, and is turnable in the top-bottom direction. The bucket 108 is formed in a concave shape, and is capable of housing earth, sand, rubble, and the like. Each bucket cylinder 109 is made of a hydraulic cylinder, and is capable of moving a rod 109b forward/backward with respect to a cylinder part 109a using a hydraulic pressure. The bucket cylinders 109 are provided so as to respectively correspond to the inner sides of the pair of booms 107. A pair of the bucket cylinders 109 each include: the cylinder part 109a having a base part that is attached to the cylinder supporting part 107b of each boom 107 so as to be turnably supported thereby; and the rod 109b having a leading end part that is attached to a rod supporting part 108a so as to be turnably supported thereby, the rod supporting part 108a being formed in a base part of each bucket 108. As illustrated in FIG. 3, the bucket 108 is made turnable in the top-bottom direction in a range indicated by an arrow M1 by driving the bucket cylinders 109, and can unload (dump) a transportation target object such as earth, sand, and rubble housed in the bucket 108,

In the track loader 100 configured as described above, when each boom cylinder 112 is driven to be elongated, each boom 107 turns about the boom supporting part 113a of each support plate 113 as a turn supporting axis, and can be moved from a position indicated by X1 to a position indicated by Y1 as illustrated in FIG, 3,

Because the track loader 100 according to the present embodiment is configured as described above, the upper frame 104 is slewed by the stewing bearing 105, whereby the direction of the bucket 108 can be changed without traveling using the traveling apparatuses 101. Hence, according to the present embodiment, the operating time of the traveling apparatuses 101 can be suppressed, and the product lifetime of underbody components such as the traveling apparatuses can be improved. Accordingly, the running cost of the track loader 100 can be reduced.

Moreover, because the track loader 100 according to the present embodiment includes the connection part 103C having the predetermined height, the cabin 104A can be positioned higher. As a result, the point of view of the operator can be made higher. Hence, the field of view of the operator can he widened, and the work safety can be enhanced.

Moreover, because the track loader 100 according to the present embodiment includes the connection part 103C having the predetermined height, the upper frame 104 can be positioned higher. Hence, support points of the booms 107 can also be made higher, and the height of the bucket 108 at the time of upward movement for dumping can be gained without adopting a complicated link mechanism. As a result, the product cost of the track loader 100 is reduced.

Further, in the track loader 100 according to the present embodiment, because the upper frame 104 can be tilted upward, the height of the bucket 108 at the time of upward movement for dumping can be made further larger.

Moreover, because the track loader 100 according to the present embodiment includes the connection part 103C having the predetermined height, the minimum ground clearance can be made higher. As a result, a bottom part of the track loader 100 can be suppressed from coming into contact with the ground in a morass, for example. Accordingly, favorable work is possible even in the morass.

Note that, in the present embodiment, in the case where the upper frame 104 faces in a direction other than the front side, a tilt restricting part that restricts a tilting operation by the tilting apparatus 106 may be provided. Moreover, in the case where the upper frame 104 is inclined, a slew restricting part that restricts a slewing operation by the slewing bearing 105 may be provided. In this case, the tilt restricting part and the slew restricting part may perform mechanical control, and may perform electronic control.

Moreover, the present embodiment has the function of slewing the upper frame 104 by the slewing bearing 105 and the function of tilting the upper frame 104 by the tilting apparatus 106, but may have a configuration without the tilting apparatus 106.

Next, with reference to FIG. 4A and FIG. 4B, an operation of unloading a transportation target object that can be performed by the track loader 100 according to the present embodiment is described in comparison with the conventional track loader 200. FIG. 4A is a diagram for describing the operation of unloading the transportation target object by the conventional track loader, and FIG. 4E is a diagram for describing the operation of unloading the transportation target object by the track loader according to the present embodiment,

As illustrated in FIG. 4A, the conventional track loader 200 performs an operation of from loading the transportation target object in a loading place P to unloading the transportation target object in an unloading place Q, according to the following work procedures.

That is, the track loader 200 first moves forward toward the loading place 2, and inserts the bucket 206 into a piled-up object piled up in the loading place P, using a thrust generated by the forward movement. Consequently, the piled-up object is housed as the transportation target object into the bucket 206. Subsequently, the track loader 200 moves backward while being largely steered so as to face the unloading place Q in order to change the direction of the track loader 200. After that, the track loader 200 moves forward toward the unloading place Q, and unloads the transportation target object in the unloading place Q.

In comparison, as illustrated in FIG. 4B, the track loader 100 according to the present embodiment can transport the transportation target object according to the following work procedures.

That is, the track loader 100 first moves forward toward the loading place P, and inserts the bucket 108 into a piled-up object piled up in the loading place P, using a thrust generated by the forward movement. Consequently, the piled-up object is housed as the transportation target object into the bucket 108. Subsequently, the track loader 100 moves backward while being slightly steered in order to move the track loader 100 to a position close to the unloading place Q. When the track loader 100 arrives at the position close to the unloading place Q, the track loader 100 stops the backward movement, and, in this state, the upper frame 104 is siewed in a counterclockwise direction. Consequently, the bucket 108 is opposed to the unloading place Q, and hence, in this state, the track loader 100 can unload the transportation target object to the unloading place Q.

In this way, according to the present embodiment, because it is not necessary to change the direction of the track loader itself, the amount of movement of the track loader can be reduced. As a result, the product lifetime of the traveling apparatuses is improved, and the running cost of the track loader is reduced.

Next, a modified example of the loader work apparatus applicable to the present embodiment is described with reference to FIG. 5. Here, FIG. 5 is a partial enlarged view illustrating a modified example of the loader work apparatus,

The loader work apparatus illustrated in FIG. 5 is provided to the upper frame 104, and includes, for example, booms 107A, boom cylinders 112A, moving cylinders 114, and moving links 115. Note that, although omitted from the illustration in FIG. 5, the bucket 108 described above is attached to the leading ends of the booms 107A. Support plates 113A that support the booms 107A are respectively provided to the right and left side surfaces of the upper frame 104. Each support plate 113A has a substantially triangular shape, and has an upper end part in which a link supporting part 116a is formed. Moreover, the upper frame 104 is provided with boom cylinder supporting plates 117 that respectively turnably support the boom cylinders 112A and moving cylinder supporting plates 115 that respectively turnably support the moving cylinders 114, and the plates 117 and 115 are arranged on the front side from the support plates 113A,

Each moving cylinder 114 is made of a hydraulic cylinder, and is capable of moving a rod 114h forward/backward with respect to a cylinder part 114a using a hydraulic pressure. As described later, the moving cylinders 114 are provided so as to respectively correspond to a pair of the booms 107A. A pair of the moving cylinders 114 each include: the cylinder part 114a having a base part that is attached so as to be turnably supported by a cylinder supporting part 115a of each moving cylinder supporting plate 115; and the rod 114h having a leading end part that is attached so as to be turnably supported by a rod supporting part 116b formed in a back end part of each moving link 116.

Each moving link 116 is formed in a substantially inverted V shape, and has a bent portion swingably supported by the link supporting part 116a. The moving link 116 is supported by the link supporting part 116a on its slightly back end side from the center. The moving link 116 has a leading end part in which a boom supporting part 116c is formed, and the boom supporting part 116c supports a base end part of each boom 107A. With this configuration, the boom 107A is swingable about the boom supporting part 116c as a support axis. In this way, in the present embodiment, the moving cylinders 114 and the moving links 116 constitute a moving apparatus.

The booms 107A are arranged in a pair on the right and left sides of the upper frame 104 so as to sandwich the upper frame 104, and are each formed in a substantially inverted V shape. A lower part of a bent portion of each boom 107A is provided with a rod supporting part 107Aa. Each boom cylinder 112A is made of a hydraulic cylinder, and is capable of moving a rod 112Ab forward/backward with respect to a cylinder part 112Aa using a hydraulic pressure. The boom cylinders 112A are provided so as to respectively correspond to the pair of booms 107A. A pair of the boom cylinders 112A each include; the cylinder part 112Aa having a base part turnably attached to a cylinder supporting part 117a of each boom cylinder supporting plate 117; and the rod 112Ab having a leading end part turnably attached to the rod supporting part 107Aa of each boom 107A. Note that, although not illustrated, a bucket cylinder for swinging the bucket 108 is also provided in an appropriate place.

In the loader work apparatus configured as described above, when each boom cylinder 112A is driven to be elongated, each boom 107A swings about the base end part of the boom 107A as a support axis, and moves upward together with the bucket 108. Moreover, when each moving cylinder 114 is driven to be elongated, each moving link 116 turns about the link supporting part 116a as a support axis in a counterclockwise direction. The moving link 116 can move along a trajectory indicated by an alternate long and short dash line Y1 between a position indicated by solid lines and a position indicated by alternate long and two short dashes lines in FIG. 5. Consequently, the boom 107A supported by the leading end part of the moving link 116 moves along a trajectory indicated by an alternate long and short dash line Y2 while being supported by the boom cylinder 112A, and the boom 107A (and the boom cylinder 112A) move between a position indicated by solid lines and a position indicated by alternate long and two short dashes lines in FIG. 5. With this configuration, the bucket 108 that may be unfavorably located backward in the case of moving the booms 107A upward can be shifted forward, and a transportation target object such as earth, sand, and rubble housed in the bucket 108 can be efficiently unloaded (dumped).

As described above, according to the present embodiment, each traveling apparatus 101 includes the track frame 101a, the sprocket, the front idler, the rear idler, and the one or more track rollers. The track frame 101a is connected to the base frame 102. The sprocket rotationally drives the rubber track. The front idler and the rear idler are arranged in the front-back direction below the sprocket, and are rotatably supported by the track frame 101a. The track rollers are arranged between the front idler and the rear idler, and are rotatably supported by the track frame 101a. The base frame 102 includes the lower frame 103, the upper frame 104, and the stewing apparatus. The lower frame 103 is interposed between the pair of track frames 101a. The upper frame 104 is provided with the loader work apparatus, and is arranged above the lower frame 103, The slewing apparatus slewably connects the upper frame 104 to the lower frame 103. The upper frame 104 is connected to the lower frame 103 at the position at which the bottom surface of the upper frame 104 is above the rubber tracks. As a result, the product lifetime of the traveling apparatuses can be improved, and the running cost of the loader work machine can be reduced. That is, the upper frame is siewed by the slewing apparatus without changing the direction of the loader work machine, whereby work by the loader work apparatus becomes possible in some cases. Hence, the driving amount of the traveling apparatuses for changing the direction of the loader work machine can be reduced, and the product lifetime of the traveling apparatuses can be improved.

Moreover, according to the present embodiment, the slewing apparatus includes the slewing bearing 105, and is capable of slewing the upper frame 104 360 degrees with respect to the lower frame 103. As a result, the work range can be widened, and the work efficiency can be improved.

Moreover, according to the present embodiment, the lower frame 103 includes the link frame 103A, the support plate 103B, and the connection part 103C. The link frame 103A connects the pair of track frames 101a to each other. The support plate 103E supports the slewing apparatus including the slewing bearing 105. The connection part 1030 connects the support plate 103B to the link frame 103A. The connection part 1030 includes the tilting apparatus 106 for lifting a front part of the support plate 103B and tilting the upper frame 104. As a result, the height of the bucket at the time of upward movement. for dumping can be made higher, and hence the work range can be widened.

Moreover, according to the present embodiment, because the tilting apparatus 106 includes the tilt cylinders 106b made of hydraulic cylinders, the operation stability and the quietness can be improved.

Moreover, according to the present embodiment, the loader work apparatus includes: the pair of right and left booms 107 (107A) supported by the base frame 102; the bucket 108 provided to the leading ends of the pair of booms 107 (107A) ; and the boom cylinders 112 (112A) capable of swinging the pair of booms 107 (107A) in the top-bottom direction. The loader work apparatus further includes the moving apparatus capable of moving the pair of booms 107 (107A) forward. As a result, a work tool that may be unfavorably located backward in the case of moving the boom upward can be shifted forward, and the work efficiency using the work tool can be improved.

Moreover, according to the present embodiment, the moving apparatus includes: the moving cylinders 114 that are supported by the base frame 102 and are each made of the hydraulic cylinder; and the moving links 116 that are turnably supported by the base frame 102 and each have one end connected to each of the moving cylinders 114 and another end connected to each of the pair of booms 107 (107A). The boom cylinders 112 (112A) are supported by the base frame 102. The pair of booms 107 (107A) are made movable forward by respectively driving the moving links 116 by the moving cylinders 114 in the state where the pair of booms 107 (107A) are respectively supported by the boom cylinders 112 (112A). As a result, the apparatus can be downsized.

Note that actions and effects described in the embodiment of the present invention are merely the most preferred actions and effects produced from the present invention, and actions and effects produced from the present invention are not limited to those described in the embodiment of the present invention.

• 100 track loader (loader work machine)
• 101 traveling apparatus
• 101a track frame
• 102 base frame
• 103 lower frame
• 103A link frame (link frame part)
• 103B support plate (support part)
• 103C connection part
• 104 upper frame
• 104A cabin
• 105 slewing bearing
• 106 tilting apparatus
• 106b tilt cylinder
• 107 boom
• 107A boom
• 108 bucket (work tool)
• 112 boom cylinder (swinging apparatus)
• 114 moving cylinder (movement cylinder)
• 116 moving link (link member)
• 201a track frame
• 201b sprocket (drive wheel)
• 201c front idler
• 201d rear idler
• 201e track roller
• 201f rubber track
• FIG. 1
• #1 TOP
• #2 BACK
• #3 BOTTOM
• #4 FRONT
• FIG. 2
• #1 TOP
• #2 RIGHT
• #3 BOTTOM
• #4 LEFT
• FIG. 3
• #1 TOP
• #2 BACK
• #3 BOTTOM
• #4 FRONT
• FIG. 5
• #1 TOP
• #2 BACK
• #3 BOTTOM
• #4 FRONT
• FIG. 6
• #1 TOP
• #2 BACK
• #3 BOTTOM
• #4 FRONT

Claims

1. A loader work machine comprising

a base frame including a cabin;

a loader work apparatus attached to the base frame; and

a pair of traveling apparatuses that support the base frame, wherein

the traveling apparatuses each include: a track frame connected to the base frame; a drive wheel that rotationally drives a traveling belt; a front idler and a rear idler that are arranged in a front--back direction below the drive wheel and are rotatably supported by the track frame; and one or more track rollers that are arranged between the front idler and the rear idler and are rotatably supported by the track frame, the traveling belt being stretched around the drive wheel, the front idler, the rear idler, and the track rollers,

the base frame includes: a lower frame that is connected to a pair of the track frames and is interposed between the pair of traveling apparatuses; an upper frame that is provided with the loader work apparatus and is arranged above the lower frame; and a stewing apparatus that slewably connects the upper frame to the lower frame, and

the upper frame is connected to the lower frame at a position at which a bottom surface of the upper frame is above the traveling belts.

2. The loader work machine according to claim 1, wherein

the slewing apparatus includes a slewing bearing, and is capable of slewing the upper frame 360 degrees with respect to the lower frame.

3. The loader work machine according to claim 1, wherein

the loader work apparatus includes a pair of right and left booms supported by the base frame; a work tool provided to leading ends of the pair of booms; and a swinging apparatus capable of swinging the pair of booms in a top-bottom direction, and

the loader work apparatus further includes a moving apparatus capable of moving the pair of booms forward,

4. The loader work machine according to claim 3, wherein

the moving apparatus includes movement cylinders that are supported by the base frame and are each made of a hydraulic cylinder; and link members that are turnably supported by the base frame and each have one end connected to each of the movement cylinders and another end connected to each of the pair of booms,

the swinging apparatus includes boom cylinders that are supported by the base frame and are each made of a hydraulic cylinder, and

the pair of booms are made movable forward by respectively driving the link members by the movement cylinders in a state where the pair of booms are respectively supported by the boom cylinders,