JP4259914B2 - Crawler belt adjustment device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a crawler belt tension adjusting device for a track-type construction machine such as a hydraulic excavator.
[0002]
[Prior art]
FIG. 3 is a side view showing a hydraulic excavator 1 as an example of a track-type construction machine. In FIG. 3, an upper swing body 3 is mounted on an upper portion of the lower traveling body 2 so as to be rotatable. An cab 4, an engine room 5, and a work implement 6 are mounted on the upper swing body 3. The lower traveling body 2 includes a pair of left and right track frames 10 and 10. An idler 14 is rotatably mounted on one side of the track frame 10 in the front-rear direction (usually the front side), and a sprocket 7 driven by a hydraulic motor (not shown) is mounted on the other side (usually the rear side) of the track frame 10. Has been. A crawler belt 8 is wound around the outer periphery of the sprocket 7 and the idler 14. Inside the track frame 10, a crawler belt tension adjusting device, which will be described later, is provided. In such a configuration, the hydraulic excavator 1 travels by driving the crawler belt 8 by rotating the sprocket 7 by rotating the hydraulic motor.
[0003]
4 is a partial side sectional view showing a configuration of an example of a crawler belt tension adjusting device 20a of a conventional hydraulic excavator, FIG. 5 is a partial plan sectional view thereof, and FIG. 6 is a front view thereof. 4 and 5, a guide portion 11 is provided along the front-rear direction at the end of the track frame 10 on the idler 14 side. In FIG. 6, the guide portion 11 is provided with a pair of left and right U-shaped frame members 10 a and 10 b on one side in the front-rear direction of the track frame 10 with the U-shaped openings facing each other. The angle members 11a, 11b and 11c, 11d are fixed to the upper and lower sides of the openings of the frame members 10a, 10b, respectively, and are formed in a groove shape in the front-rear direction. A stepped portion 13 provided at the left and right ends of the idler support member 12 is engaged with the guide portion 11, and the stepped portion 13 is slidable in the front-rear direction along the guide portion 11. ing. Between the guide part 11 and the stepped part 13 of the idler support member 12, gaps a and b are provided in the vertical and horizontal directions, respectively.
[0004]
4 and 5, an idler 14 is rotatably attached to one end portion of the idler support member 12. An urging device 25 having a recoil spring 21 is disposed between the idler support member 12 and the seat plate 15 attached to the track frame 10. The base end portion of the rod 22 penetrating substantially the center of the recoil direction of the recoil spring 21 is attached to the seat plate 15, and the guide plate 24 mounted on the base end side with respect to the distal end portion 23 of the rod 22 is attached to the distal end side by the recoil spring 21. By energizing (in the direction of the idler 14), the tip 23 of the rod 22 is urged toward the idler support member 12 side. The recoil spring 21 is set to a predetermined mounting length by the rod 22. The guide plate 24 is slidably engaged with the guide portion 11.
[0005]
A boss 16 is provided at an end of the idler support member 12 opposite to the idler 14, and a piston 32 is slidably fitted in a cylinder 31 provided in the boss 16 in the front-rear direction. The tip portion 23 of the rod 22 is in contact with the end surface 33 of the piston 32 opposite to the cylinder 31. A grease chamber 34 is formed by the bottom portion of the cylinder 31 and the tip end surface of the piston 32. The cylinder 31 and the piston 32 constitute a tension adjusting device 30. By injecting grease into the grease chamber 34, the piston 32 is provided. The recoil spring 21 is compressed via the tip 23 of the rod 22 and the tension of the crawler belt 8 is increased by the urging force of the recoil spring 21. That is, an idler support member 12 that rotatably supports the idler 14 and is movable in the longitudinal direction of the vehicle, and is provided between the idler support member 12 and the track frame 10, and the idler support member 12 is provided. An urging device 25 having a recoil spring 21 that urges the idler 14 toward the idler 14, and a tension adjusting device 30 that is provided between the idler support member 12 and the urging device 25 and adjusts the tension of the crawler belt 8. The crawler belt tension adjusting device 20a is configured, and the tension of the crawler belt 8 can be adjusted by the amount of grease filled in the grease chamber 34.
[0006]
FIG. 7 is a front view of the guide plate 24 taken along the line BB in FIG. In FIG. 7, four corners 24a, 24b, 24c, and 24d on the outer periphery of the guide plate 24 are slidably engaged with the left and right guide portions 11 and 11 of the track frame 10, and their positions are set in the left and right and up and down directions. It is regulated. Therefore, the axis XX of the rod 22 shown in FIG. 5 is always held at the normal position.
[0007]
By the way, in the crawler belt tension adjusting device for a large vehicle, each component is large and heavy. Therefore, in order to facilitate the assembly of the underbody device, the idler support member 12 and the recoil spring 21 are separated from each other as in the above example, and the urging force of the recoil spring 21 is transmitted by contacting each other in the front-rear direction. It is common to make it.
[0008]
However, as described above, predetermined gaps a and b are provided in the vertical direction and the horizontal direction between the engaging portions of the guide portions 11 and 11 and the idler support member 12, respectively. Therefore, when the vehicle travels on rough terrain, for example, an uneven load is applied to the idler 14, and the center line YY of the idler support member 12 is, as shown in the partial plan view of the plane of the idler support member 12 in FIG. Tilt left and right. As a result, the contact point P between the end surface 33 of the piston 32 and the distal end portion 23 of the rod 22 is displaced by c from the axis XX of the rod 22, and the alignment of the entire suspension is shifted. Further, since the idler support member 12 is inclined, there is a problem that the contact pressure of the contact portion with the guide portion 11 becomes large and wears and is damaged at an early stage, and the idler 14 cannot be stably supported.
[0009]
When an upward force is applied to the idler 14, the center line YY of the idler support member 12 is inclined as shown in the side sectional view of the idler support member 12 in FIG. 9, and the end surface 33 of the piston 32 is inclined. The contact point P between the rod 22 and the tip 23 of the rod 22 is displaced in the vertical direction by d from the axis XX of the rod 22. Therefore, the contact pressure of the contact part of the idler support member 12 and the guide part 11 becomes large, and there is a problem that these members are worn early.
[0010]
As means for solving the above problems, for example, Patent Document 1 describes an idler support structure for a construction machine, and Patent Document 2 describes a crawler belt tension adjusting device.
[0011]
FIG. 10 is a plan view showing the configuration of the idler support mechanism described in Patent Document 1 with the adjuster in cross section. In FIG. 10, a shaft portion 52 provided on the base end side of a yoke (corresponding to the idler support member) 51 that supports the idler 50 is connected and fixed to the distal end of the piston 62 that protrudes from the cylinder 61 that constitutes the adjuster 60. The joined member 63 is joined. A projection 65 is formed on the end surface of the joining member 63 at the center of the surrounding joining surface 64. The front end surface of the shaft portion 52 of the yoke 51 is a joining surface 53 formed in an annular shape, and a fitting recess 54 for fitting the projection 65 of the joining member 63 is formed in the center portion thereof. As described above, the yoke 51 and the joining member 63 provided on the piston 61 are concavo-convexly fitted so that relative movement is restricted except in the axial direction of the piston 62. Thus, the movement of the idler 50 and the yoke 51 connected to the idler 50 during traveling can be effectively restricted.
[0012]
In Patent Document 2, the yoke that supports the idler and the tension adjusting cylinder of the crawler belt are integrally connected by a quick joint. This prevents the yoke and the tension adjustment cylinder from being bent so that the idler can be bent over a long period of time even when a load in the vertical direction or the horizontal direction other than the front and rear directions is applied to the idler. It is said that it can be supported stably.
[0013]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-124067 (page 4, FIG. 1)
[Patent Document 2]
Japanese Unexamined Patent Publication No. 2000-85646 (page 4-5, FIG. 3)
[0014]
[Problems to be solved by the invention]
However, the above configuration has the following problems.
In the one described in Patent Document 1, the shaft portion 52 of the yoke 51 that supports the idler 50 is joined to the joining member 63 that is connected and fixed to the tip of the piston 62 that protrudes from the cylinder 61 that constitutes the adjuster 60. . In the joining configuration, the protrusion 65 formed at the center of the joining member 63 is concavo-convexly fitted into the fitting recess 54 provided on the tip surface of the shaft portion 52 of the yoke 51. For this reason, when an external force for tilting the yoke 51 is applied to the idler 50, a bending force is applied between the cylinder 61 and the piston 62 or between the fitting recess 54 and the protrusion 65, which may cause damage.
In the thing of patent document 2, the structure of a quick coupling is complicated and cost becomes high.
[0015]
The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a crawler belt tension adjusting device that is easy to assemble and has a simple structure without causing damage to components.
[0016]
[Means, actions and effects for solving the problems]
In order to achieve the above object, the first invention is a crawler type traveling in which a crawler belt is wound between an idler and a sprocket that are rotatably provided at one end and the other end of a track frame in the front-rear direction. In a crawler belt tension adjusting device comprising a device and biasing the idler to adjust the crawler belt tension, a guide portion provided on one side in the front-rear direction of the track frame, and a track frame engaged with the guide portion longitudinal direction movably mounted on the idler support member on which the idler is rotatably mounted on one side, a boss which is installed in the said idler opposite side of the idler support member, the idler of the boss a piston slidably fitted in the front-rear direction to the support member and formed on the opposite side in the cylinder, said piston and track frame And an urging device having a recoil spring for urging the idler support member toward the idler while being in contact with an end portion of the piston, and an end of the boss on the urging device side the section has a configuration in which a support plate for supporting the idler support member movably in the front-rear direction engages with the guide portion.
[0017]
According to the first invention, even when an external force is applied to the idler to incline the idler support member , the support plate provided at the end opposite to the idler of the boss attached to the idler support member is movable in the front-rear direction. Since the support member is supported, the end of the idler support member opposite to the idler is not displaced or tilted with respect to the axis of the recoil spring, so the idler support member and the guide are less worn. , No damage. Also, because the biasing device having a recoil spring and a tension adjusting device (consisting of the boss and a piston slidably fitted in a cylinder formed on the boss) are brought into contact with each other in the front-rear direction, An excessive force is not applied to each member of the crawler belt tension adjusting device. Therefore, there is no fear that the constituent members are damaged, and the crawler belt tension adjusting device is obtained that is easy to assemble, has a simple structure, and is low in cost.
[0018]
According to a second invention, in the first invention, the support plate is divided into a plurality of parts and is detachably attached.
[0019]
According to the second invention, the support plate is divided into a plurality of parts and is detachably attached to the other end portion of the idler support member. Therefore, the attachment and detachment becomes very easy and the number of assembling steps can be reduced.
[0020]
According to a third invention, in the second invention, a circumferential groove portion into which the support plate is fitted is provided at an end portion of the boss on the biasing device side .
[0021]
According to the third aspect of the present invention, the support plate is very easily positioned and attached by fitting the support plate into the groove provided in the circumferential direction at the end of the boss on the biasing device side. Since there is no possibility of shifting in the longitudinal direction of the support member, that is, in the front-rear direction, the crawler belt tension adjusting device can always be operated stably.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a crawler belt tension adjusting device according to the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 is a partial cross-sectional view of an idler support portion of the crawler belt tension adjusting device 20. In addition, the same code | symbol is attached | subjected to the member which has a function substantially the same as the conventional thing shown in FIG. 5, the description is abbreviate | omitted, and only a different part is demonstrated.
In FIG. 1, an annular groove portion 17 is formed on an outer peripheral portion of an end portion of a boss 16 attached to an end portion of the idler support member 12 opposite to the idler 14. A support plate 40 is fitted and attached to the groove portion 17, and a part of the outer surface portion of the support plate 40 is slidably engaged with the guide portion 11 of the track frame 10. In addition, although the figure shows the structural example which attached the idler support member 12 and the boss | hub 16 with the volt | bolt, it is good also as an integral structure.
[0024]
FIG. 2 is an AA arrow view of FIG. 1, and the detailed structure of the support plate portion will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the member which has a substantially the same function as the conventional thing shown in FIG. 6, the description is abbreviate | omitted, and only a different part is demonstrated.
In FIG. 2, the support plate 40 includes a first plate 41 and a second plate 42 each having a shape in which a plate having a through hole 40a formed in a substantially central portion thereof is divided into two vertically so as to pass through the through hole 40a. . Both the plates 41 and 42 are fastened so that they can be coupled and divided with bolts 43 by fitting the through holes 40 a into the grooves 17 on the outer peripheral surface of the boss 16. Further, substantially vertical swing surfaces 41a, 41b and 42a, 42b are formed on the upper left and right side portions and the lower left and right side portions of both plates 41, 42, respectively, and these swing surfaces 41a, 41b, 42a are formed. , 42b are slidably opposed to the inner end surface of the guide portion 11 in the left-right direction, and the support plate 40 is fitted between the left and right guide portions 11, 11. That is, the upper and lower portions of the support plate 40 are fitted and inserted into the angle members 11a, 11b, 11c, and 11d with a predetermined gap s in the left-right direction, and the lower left and right ends of the support plate 40 are angle members. It is in contact with the upper surfaces of 11b and 11d.
[0025]
Since the crawler belt tension adjusting device of the present invention is configured as described above, the following effects can be obtained.
In FIG. 1, when an external force to tilt the idler 14 in the left-right direction is applied, the support plate 40 is positioned in the vicinity of the piston 32, so the center P of the end surface 33 of the piston 32 is the axis of the rod 22. There is no significant deviation from the line XX in the left-right direction. Further, even when the idler 14 is pushed up from below and an upward external force is applied, the lower surface of the support plate 40 is in contact with the guide portion 11, so that the center P of the end surface 33 of the piston 32 is not shifted downward. . Furthermore, since the piston 32 and the rod 22 are only in contact with each other, an excessive force is not generated on each member of the crawler belt tension adjusting device such as the rod 22. Furthermore, since the idler support member portion and the recoil spring portion are separated from each other, the assembly parts can be miniaturized, and the parts can be handled and assembled very easily. Accordingly, there is obtained a crawler belt tension adjusting device which is free from damage to members, can be easily assembled, has a simple structure, and is inexpensive.
[0026]
In the present embodiment, the support plate 40 has a plate configuration divided into two parts, but the division method (the shape, position, number, etc. of the division) is not limited to this.
Further, the support plate 40 is fitted and fastened to the groove portion 17 on the outer peripheral surface of the boss portion opposite to the idler 14 of the idler support member 12, but the boss 16 and the support plate 40 are integrally configured (welding structure, The idler support member 12 and the support plate 40 may be integrated. Furthermore, the support plate 40 does not have to have a plurality of divided configurations.
[0027]
According to the present invention, the support plate for engaging the guide portion and slidably supporting the idler support member in the front-rear direction is provided at the end of the idler support member opposite to the idler. Even if an external force in the direction is applied, the idler support member is not inclined with respect to the front-rear direction, so that wear of the contact portion between the idler support member and the guide portion can be reduced. Further, the sliding structure of the idler support member can be configured with a simple structure, and the crawler belt tension adjusting device can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional plan view of an idler support portion of a crawler belt tension adjusting device of the present invention.
FIG. 2 is a view taken in the direction of arrows AA in FIG.
FIG. 3 is a side view of a hydraulic excavator.
FIG. 4 is a side sectional view of a conventional crawler belt tension adjusting device.
FIG. 5 is a partial cross-sectional view of the same plane.
FIG. 6 is a front view of the same.
7 is a view taken along arrow BB in FIG. 5;
FIG. 8 is a plan view showing a left-right misalignment between a conventional idler support member and a recoil spring.
FIG. 9 is a side view showing the vertical misalignment.
FIG. 10 is a plan view of a second example of a conventional crawler belt tension adjusting device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 8 ... Track, 10 ... Track frame, 11 ... Guide part, 11a, 11b, 11c, 11d ... Angle member, 12 ... Idler support member, 13 ... Stepped part, 14 ... Idler, 16 ... Boss, 17 ... Groove part, 20 , 20a ... crawler belt tension adjusting device, 21 ... recoil spring, 22 ... rod, 23 ... tip, 25 ... biasing device, 30 ... tension adjusting device, 31 ... cylinder, 32 ... piston, 33 ... end face, 40 ... support plate 41 ... 1st plate, 42 ... 2nd plate.

Claims (3)

A crawler type traveling device in which a crawler belt (8) is wound between an idler (14) and a sprocket (7) that are rotatably provided at one end and the other end of a track frame (10), respectively. A crawler belt tension adjusting device for biasing the idler (14) to adjust the tension of the crawler belt (8),
A guide portion (11) provided on one side in the front-rear direction of the track frame (10);
An idler support member (12) engaged with the guide portion (11) and provided movably in the front-rear direction of the track frame (10), and the idler (14) rotatably attached to one side;
A boss (16) which is installed in the opposite side of the idler (14) of the idler support member (12),
Wherein an idler support member (12) and slidably fitted in the longitudinal direction on the opposite side of the formed cylinder (31) within by a piston (32) of the boss (16),
Provided between the piston (32) and the track frame (10), and urges the idler support member (12) toward the idler (14) by contacting the end of the piston (32). An urging device (25) having a recoil spring (21) to be
An end portion of said biasing device (25) side of the boss (16), the support plate (40 supporting a movably said idler support member (12) engages in the longitudinal direction on the guide portion (11) Crawler belt tension adjusting device. The crawler belt tension adjusting device according to claim 1, wherein the support plate (40) is divided into a plurality of pieces and is detachably attached. The crawler belt tension adjusting device according to claim 2,
A crawler belt tension adjusting device, wherein a circumferential groove (17) into which the support plate (40) is fitted is provided at an end of the boss (16) on the biasing device side.

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