JP2014189224A - Crawler type travel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crawler type travel device for increasing an expansion-contraction stroke of a crawler, while maintaining even durability of a fitting part between a car body and a crawler frame, by maintaining frame rigidity of the car body.SOLUTION: A crawler frame 20 comprises an overhang part 13 of laterally projecting in front and in rear of a car body main body 11 and a fitting part 22 slidably fitting in the vehicle width direction, and thereby, the crawler frame 20 is movably connected in the vehicle width direction to a car body 10. A root part 14 of the overhang part 13 to the car body main body 11 is inclined so that the distant side from a turning center C of a swivel base 12 on the longitudinal direction in a plan view, becomes near to a central axis CL in the vehicle width direction of the car body main body 11. An outside end part 15 in the vehicle width direction of the overhang part 13 is parallel to the longitudinal direction. An opening end part 23 of the fitting part 22 is inclined as a whole in the same direction as the root part 14 of the corresponding overhang part 13 in a plan view.

Description

  The present invention relates to a crawler type traveling device, and more particularly to a crawler type traveling device capable of expanding and reducing a crawler width.

  A crawler such as a building demolition machine or a crawler crane is advantageous when it is wider for the purpose of gaining stability (falling fulcrum), while it needs to be small so that it can fit within the width of the transport carriage during transportation. is there. In addition, due to the recent increase in compliance awareness, these machines are required to have stricter compliance.

  For larger machines above a certain level, the crawler is removed to reduce the conveyance width. However, removing the crawler requires a lot of time, labor, and costs, and the mechanical mobility of the machine is impaired. Has been proposed. For example, a configuration has been proposed in which the car body has an H-type axle structure, two crawler frames (track frames) have a box structure at two front and rear positions, the axle is fitted therein, and the width of the crawler can be increased or decreased by a hydraulic cylinder. (See Patent Document 1).

  In order to further increase the expansion / contraction stroke of the crawler, a configuration has been proposed in which a separate block is attached to and removed from the front end of the axle of the car body, and when the crawler is contracted, the block is stored inside the outer edge of the shoe (Patent Document). 2).

Japanese Utility Model Application Publication No. 1-25753 Utility Model Application Publication No. 62-5429

  However, Patent Document 1 has a structure in which a car body and a crawler frame are fastened using a wedge and a fastening cylinder, which makes the structure complicated and disadvantageous in terms of cost and reliability.

  In general, in a relatively small model that is assumed to be transported with a crawler attached, the shoe width is often substantially equal to the width of each of the left and right crawler frames in order to reduce the transport width. Therefore, in reality, as disclosed in Patent Document 2, it is difficult to attach and detach a separate block to the front end of the axle so that the block fits within the shoe width when the crawler contracts. In addition, in a machine such as a building demolition machine that has a heavy load on the undercarriage, there is a demand to increase the cross-sectional strength by configuring the crawler frame to be as large as the shoe width.

  An example of a crawler type traveling device will be described with reference to FIGS. 7 and 8. The lower traveling body 302 includes a car body 310 and left and right crawler frames 320. The car body 310 is provided with axles 313 that protrude in the left-right direction on both front and rear sides of the car body main body 311. The left and right crawler frames 320 are provided with hollow axle boxes 322 on both front and rear sides, and the front and rear axles 313 are slidably fitted to the axle boxes 322 in the vehicle width direction, so that each crawler frame 320 has a car body. It is connected to 310 so as to be movable in the vehicle width direction.

  In this example, in order to expand the expansion / contraction width of the crawler frame 320 without adopting the configuration of Patent Document 2, the axle 313 is not extended to the distal end side (end portion 315 side), but the base side (swivel) It is necessary to extend to the center side. However, in order to extend the axle 313 to the base side, it is necessary to cut the car body main body 311 supporting the upper revolving body. Considering the strength and rigidity of the entire frame, it is not possible to extend the axle 313 beyond the current level. Have difficulty. In addition, the expansion / contraction stroke (L11 in FIG. 8) can be increased by shortening the insertion allowance (L12 in FIG. 8) of the axle 313 with respect to the axle box 322 when the vehicle width is widened. Increases, the contact pressure of the fitting part (insertion part) increases, and a problem arises in durability. In some machines that have become old, this part has sag, and the crawler has a letter C shape when viewed from the front.

  Therefore, the present invention provides a crawler type traveling device capable of increasing the expansion / contraction stroke of the crawler while maintaining the rigidity of the frame of the car body and maintaining the durability of the fitting portion between the car body and the crawler frame. For the purpose.

  In order to achieve the above object, the present invention is a crawler type traveling device in which a crawler frame is connected to both the left and right sides of a car body, and the car body is provided with a swivel base on which an upper turning body is mounted. The main body and overhanging portions protruding left and right on both front and rear sides of the car body main body, and the left and right crawler frames have front and rear fitting portions that are slidably fitted in the vehicle width direction. Thus, each crawler frame is connected to the car body so as to be movable in the vehicle width direction, and the base portion of the overhanging portion with respect to the car body body is far from the turning center of the swivel base in the front-rear direction. And the end of the overhanging portion on the outer side in the vehicle width direction is parallel to the front-rear direction, and the crawler frame Open end of the engagement portion, in a plan view, provides a crawler type traveling device configured to be inclined as a whole in the same direction as the base of the corresponding overhang.

  Here, it is preferable that the opening end part of the fitting part of the crawler frame has a parallel part extending in parallel with the front-rear direction on the side far from the turning center with respect to the front-rear direction.

  According to the crawler type traveling device of the first aspect, the base portion of the overhanging portion with respect to the car body main body is close to the center axis in the vehicle width direction of the car body main body in the front-rear direction and the side far from the turning center of the swivel base in the front-rear direction. The end of the overhanging portion in the vehicle width direction is parallel to the front-rear direction, and the opening of the fitting portion of the crawler frame is inclined in the same direction as the base portion of the corresponding overhanging portion as a whole. Is configured to do. According to this configuration, the rigidity of the frame is maintained by maintaining the cross-sectional size of the car body in the vicinity of the turntable, and the fitting length on the front and rear sides of the vehicle body (the side far from the turn center of the turntable in the front-rear direction). It is possible to increase the expansion / contraction stroke of the crawler while maintaining durability by ensuring the above.

  According to the crawler type traveling device of the second aspect, the opening of the fitting portion of the crawler frame has a parallel portion extending in parallel with the front-rear direction on the side far from the turning center with respect to the front-rear direction. The front and rear sides of the vehicle body (the side far from the turning center) of the fitting part is heavily responsible for receiving the load, but since this part is provided with a parallel part, stress concentration can be avoided and the load is received at a highly rigid part. Can do.

1 is a schematic side view showing a work machine according to an embodiment of the present invention. The top view which shows the crawler type traveling apparatus by this embodiment. III-III sectional view taken on the line of FIG. FIG. 3 is a partial cross-sectional view taken along a horizontal cross section passing through an axle in the lower traveling body of FIG. 2. The partial top view which shows the fitting part vicinity of an axle and a crawler frame in the lower traveling body of FIG. The fragmentary top view which shows the fitting part of the axle and crawler frame by another example. The top view which shows the crawler type traveling apparatus by a comparative example. VIII-VIII sectional view taken on the line of FIG.

  A crawler type traveling device according to an embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a hydraulic excavator is illustrated as an example of a work machine.

  As shown in FIG. 1, the hydraulic excavator 1 includes a crawler type lower traveling body 2 (crawler type traveling device), an upper revolving body 3 mounted on the lower traveling body 2 so as to be rotatable about a vertical axis, and an upper revolving body. It is comprised by the work attachment 4 with which the front part of the body 3 was mounted | worn.

  The lower traveling body 2 includes a car body 10 and left and right crawler frames 20 as shown in FIGS. 2 and 3. For convenience of explanation, the front-rear and left-right directions are defined as shown in FIG.

  The configuration of the car body 10 will be described. A cylindrical swivel bearing support 17 (FIG. 4) is attached to the car body main body (main body frame) 11, and a swivel bearing for supporting the swivel base 12 is accommodated inside the swivel bearing support 17. On the swivel base 12, the upper swivel body 3 is rotatably mounted.

  In addition, an axle (projecting portion) 13 protruding in the left-right direction on both the front and rear sides of the car body main body 11 is joined by welding or the like. This connecting portion is referred to as a base portion 14 of the axle 13. As shown in FIG. 4, the front, rear, left and right axles 13 are also joined to the outer peripheral surface of the swivel bearing support 17.

  The axle 13 is a member having a cross-sectional “mouth” shape. Further, as shown in FIGS. 2 and 3, the end 15 on the outer side in the vehicle width direction of the axle 13 is parallel to the front-rear direction.

  On the other hand, each base portion 14 of the axle 13 has a “C” shape in a plan view, that is, the side far from the turning center C of the turntable 12 in the front-rear direction is the vehicle width direction (left-right direction) of the car body main body 11. ) It is configured to incline so as to approach the central axis CL. That is, the cross section of the car body main body 11 is small on the side far from the turning center C, but the size of the cross section (for example, the cross section DD in FIG. 2) is maintained near the swivel bearing support 17. The rigidity of the frame is greatly reduced.

  As shown in FIG. 3, the cross-sectional height H <b> 1 of the car body main body 11 is configured to be larger than the cross-sectional height H <b> 2 of the axle 13. This also increases the rigidity of the frame of the car body main body 11. In the present embodiment, the base portion 14 of the axle 13 corresponds to a portion where the height of the axle 13 shifts from H2 to H1.

  Next, the crawler frame 20 will be described. A drive wheel 28 is provided at the rear end of the left and right crawler frames 20, and an idler wheel 29 is provided at the front end, and a shoe 21 (not shown in FIG. 2) is installed around the outer periphery of the crawler frame 20. Has been.

  Each crawler frame 20 is provided with hollow axle boxes 22 on both front and rear sides. When the front and rear axles 13 are slidably fitted in the axle box 22 in the vehicle width direction, the crawler frames 20 are connected to the car body 10 so as to be movable in the vehicle width direction.

  Further, the expansion / contraction cylinder 30 is provided in a horizontal posture between the car body 10 and both the crawler frames 20 at the center position in the front-rear direction of the car body 10. The expansion / contraction operation of the expansion / contraction cylinder 30 by hydraulic control moves the left and right crawler frames 20 in the vehicle width direction, and the vehicle width is expanded / contracted. 2 and 3 show a state in which the left crawler frame 20 has increased the vehicle width and a state in which the right crawler frame 20 has reduced the vehicle width.

  FIG. 5 is an enlarged view of the vicinity of the fitting portion (axle box 22) between the axle 13 and the crawler frame 20. As shown in FIG. As shown in FIG. 5, the opening end 23 of the axle box 22 has a first parallel portion 23A, an inclined portion 23B, and a second parallel portion 23C.

  In the axle box 22 of FIG. 5, the first parallel portion 23A extends in parallel to the front-rear direction on the front side of the inclined portion 23B, that is, the side farther from the turning center C with respect to the front-rear direction. The inclined portion 23B is inclined in the same direction as the base portion 14 of the corresponding axle 13, that is, substantially parallel. The second parallel portion 23C extends in parallel with the front-rear direction on the rear side of the inclined portion 23B, that is, the side closer to the turning center C with respect to the front-rear direction.

  As described above, the opening end portion 23 is configured to be inclined in the same direction as the base portion 14 of the corresponding axle 13 as a whole, that is, substantially in parallel. Accordingly, as can be seen from the crawler frame 20 on the right side of FIG. 2, the crawler frame 20 can be brought closer to the car body 10 side in the vehicle width reduced state. That is, the vehicle width when transporting the work machine can be further reduced. Compared with the position of the crawler frame 320 on the right side in FIG. 7, it can be seen that the crawler frame 20 in FIG. 2 is closer to the turntable 12.

  The fitting part of the axle 13 with respect to the axle box 22 in the vehicle width enlarged state will be described. As shown in FIG. 5, the fitting length L2 of the axle box 22 on the vehicle front-rear side (the side far from the turning center C with respect to the front-rear direction) is the fitting length L2 on the vehicle body center side (the side closer to the turning center C with respect to the front-rear direction). It is larger than the length L3.

  By the way, during the work of the work machine, a load that causes pitching (arrow A in FIG. 1) and rolling is applied to the upper swing body 3. As a result, this load is also transmitted to the lower traveling body 2 connected to the upper swing body 3, and accordingly, at the contact portion (fitting portion) between the axle 13 on the car body 10 side and the axle box 22 on the crawler frame 20 side. This load also works. In particular, considering the pitching indicated by the arrow A in FIG. 1, this load increases on the vehicle front-rear side (the side far from the turning center C).

  Therefore, from the viewpoint of durability of the fitting portion, the fitting length L2 on the side farther from the turning center C is more important than the fitting length L3 on the side closer to the turning center C. In the present embodiment, the durability is maintained by sufficiently securing the fitting length L2 on the side far from the turning center C.

  In an actual example, the fitting length L2 (FIGS. 3 and 5) on the side far from the turning center C in the present embodiment is larger than the fitting length L12 in the comparative example (FIG. 8) and close to the turning center C. The fitting length L3 (FIG. 5) on the side is smaller than the fitting length L12 according to the comparative example (FIG. 8). As described above, since the fitting length L2 on the side far from the turning center C is more important in terms of durability, it is possible to maintain the durability as a whole.

  Moreover, in this embodiment, the opening end part 23 of the axle box 22 has the 1st parallel part 23A extended in parallel with the front-back direction. Here, of the contact portion (fitting portion) between the axle 13 and the axle box 22 as described above, the portion that receives the load is large on the side far from the turning center C.

  For this reason, for example, as shown in FIG. 6, when the opening end portion 123 of the axle box 22 is linearly inclined, the front side (the side far from the turning center C) of the contact portion between the axle 13 and the axle box 22. Stress concentrates at the end (point B). In the present embodiment, since the first parallel portion 23A is provided in this portion, stress concentration can be avoided, and both the axle 13 and the axle box 22 can receive a load reliably at a portion having high rigidity.

  According to the embodiment described above, the frame rigidity of the car body 10 is maintained, and the fitting length of the axle 13 with respect to the axle box 22 is secured, thereby maintaining the durability and increasing the expansion / contraction stroke of the crawler. Is possible. Actually, the expansion / contraction stroke L1 (FIG. 3) of the lower traveling body according to the present embodiment is larger than the expansion / contraction stroke L11 in the comparative example (FIG. 8).

<Modification>
The crawler type traveling device according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims.

  In the above-described embodiment, the car body 10 is configured by joining the four front and rear axles 13 to the car body main body 11. The present invention is not limited to such a configuration. For example, the car body may be configured by joining a pair of front and rear axles to the car body main body.

  Further, the second parallel portion 23 </ b> C is not necessarily provided at the opening end portion 23 of the axle box 22.

  Moreover, in the said embodiment, although the base part 14 of the axle 13 was comprised so that it might incline linearly by planar view, one part or all may be comprised by the curve. Similarly, part or all of the opening end 23 of the axle box 22 may be configured in a curved line.

  As described above, the crawler type traveling device according to the present invention is useful as a crawler type traveling device used for work machines such as building demolition machines, crawler cranes, hydraulic excavators, and other various traveling vehicles.

1 hydraulic excavator, 2 lower traveling body, 3 upper turning body,
4 work attachments, 10 car bodies, 11 car body bodies,
12 swivel, 13 axle, 14 root, 15 axle end,
17 slewing bearing support, 20 crawler frame, 21 shoe,
22 axle box, 23 opening end, 23A first parallel part,
23B inclined part, 23C second parallel part, 28 driving wheel, 29 idler wheel,
30 Expansion / contraction cylinder.

Claims (2)

A crawler type traveling device in which a crawler frame is connected to both left and right sides of a car body,
The car body has a car body main body provided with a swivel base on which an upper revolving body is mounted, and an overhanging portion protruding left and right on both front and rear sides of the car body main body,
The left and right crawler frames have front and rear overhang portions and front and rear fitting portions that slidably fit in the vehicle width direction, so that each crawler frame can move in the vehicle width direction with respect to the car body. Are connected,
The base portion of the overhang portion with respect to the car body body is inclined so that a side far from the turning center of the swivel base in the front-rear direction is close to the vehicle axis direction center axis of the car body body, and The outer end of the part in the vehicle width direction is parallel to the front-rear direction,
The crawler type traveling device is configured such that an opening end portion of the fitting portion of the crawler frame is inclined as a whole in the same direction as a base portion of a corresponding overhang portion in a plan view. The crawler type traveling device according to claim 1, wherein an opening end portion of the fitting portion of the crawler frame has a parallel portion extending in parallel with the front-rear direction on a side far from the turning center with respect to the front-rear direction.

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