JP2000085646A - Crawler belt tension adjuster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent relative displacement or inclination between a yoke and a tension adjusting cylinder by loads acting on an idler wheel, and facilitate their installation. SOLUTION: A yoke 16 for supporting an idler wheel 9 and a tension adjusting cylinder 17 are integrally interconnected via a quick-disconnection coupling 26. Both yoke 16 and tension adjusting cylinder 17 are thus prevented from jackknifing to hold the idler wheel 9 supported stably for a longer period even when it receives vertical and horizontal loads in addition to back-and-forth loads. For appreciably improved assembly, both yoke 16 and tension adjusting cylinder 17 are also allowed to be integrally interconnected via the quick- disconnection coupling 26 within a side frame 3 even after they are individually installed in the side frame 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crawler belt tension adjusting device suitably used for a tracked vehicle such as a hydraulic shovel.

[0002]

2. Description of the Related Art In general, a tracked vehicle such as a hydraulic shovel has a floating wheel provided at one end of a side frame constituting a truck frame, a driving wheel provided at the other end of the side frame, and a floating wheel. A crawler belt wound between the wheel and the drive wheel, and a crawler belt tension adjusting device provided between the side frame and the idler wheel for adjusting the tension of the crawler belt.

Here, the crawler belt tension adjusting device is usually provided at one end of the side frame so as to be movable forward and backward, and is provided between a yoke for rotatably supporting the idler wheel and the side frame and the yoke. A tension adjusting cylinder for adjusting tension in front and rear directions of the crawler belt, and a compression spring provided between the side frame and the tension adjusting cylinder are provided. Cylinders and the like are arranged along the front and rear axes.

In the above-described crawler belt tension adjusting device, the crawler belt flexes according to the ups and downs of the ground when the hydraulic excavator travels, and a forward or rearward load acts on the idler wheel.
This load is transmitted to the compression spring via the yoke, the tension adjusting cylinder, and the like. And the compression spring expands and contracts according to the load,
By moving the tension adjusting cylinder forward and backward with the yoke in accordance with the expansion and contraction of the compression spring, the crawler belt provides an appropriate tension between the idler wheel and the drive wheel.

A crawler belt tension adjusting device according to the prior art includes a tension adjusting cylinder having a distal end abutted on a yoke by a spring force of a compression spring, and a tension adjusting cylinder having a distal end fixed to a yoke using bolts or the like. Some have done.

As another prior art, a yoke for supporting idler wheels and a cushion mechanism for adjusting crawler belt tension are connected via a lever which is swingably attached to a track frame. A crawler belt tension adjusting device is known (for example, Japanese Utility Model Laid-Open No. 1-81185).

[0007]

Here, since hydraulic excavators often travel on uneven terrain such as rough terrain, for example, when climbing over rocks or the like, crawler tracks are pushed up from the ground, By tilting left and right with respect to the horizontal direction,
Loads from various directions such as a downward direction, a left direction, and a right direction are applied.

For this reason, in the crawler belt tension adjusting device in which the tip of the tension adjusting cylinder is brought into contact with the yoke by the spring force of the compression spring, the crawler belt tension adjusting device moves upward and downward relative to the idler wheel.
When a load in the left or right direction is applied, the contact portion between the yoke and the tension adjusting cylinder is displaced, or the yoke and the tension adjusting cylinder are displaced from each other with respect to the front and rear axes. May be displaced relative to each other. This allows the yoke, tension adjusting cylinder or yoke to be
There is a problem in that a member or the like that is supported to be movable in the rearward direction is worn or damaged at an early stage, and the idler wheel cannot be stably supported.

On the other hand, in the crawler belt tension adjusting device in which the tip of the tension adjusting cylinder is fixed to the yoke by bolts or the like, even if a load in the upward, downward, left, or right direction acts on the idler wheel, The contact part with the tension adjustment cylinder is displaced, or the yoke and the tension adjustment cylinder are
It is possible to prevent relative displacement so as to be bent in a “C” shape with respect to the rearward axis, and prevent the yoke, the tension adjusting cylinder, and the like from being worn or damaged early.

However, in the crawler belt tension adjusting device in which the tip of the tension adjusting cylinder is fixed to the yoke with bolts or the like, the idler wheel, the yoke, the tension adjusting cylinder and the like are assembled as a subassembly, and the subassembly is assembled. You need to attach your body to the side frame. For this reason, there is a problem that the weight of the subassembly body increases, and the workability when assembling the idler wheel, the yoke, the tension adjusting cylinder, and the like to the side frame is reduced.

Further, in the above-described crawler belt tension adjusting device according to the related art, the operation of connecting the yoke and the cushion mechanism via the lever that is swingably attached to the track frame is performed in the narrow track frame. And the workability is poor. Further, providing a lever between the yoke and the cushion mechanism causes a problem that the crawler belt tension adjusting device is increased in size and cost is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and can prevent the yoke and the tension adjusting cylinder from being relatively displaced inclining due to a load acting on an idler wheel, and can be mounted on a track frame. It is an object of the present invention to provide a crawler belt tension adjusting device capable of improving workability at the time.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a yoke provided at one end of a side frame constituting a track frame and movable forward and backward. An idler wheel rotatably supported and having a crawler belt wound around a drive wheel provided at the other end of the side frame; and a front and rear direction of the crawler belt provided between the yoke and the side frame. Crawler belt tension adjustment comprising: a tension adjustment cylinder for adjusting the tension of the crawler belt; and a compression spring provided between the side frame and the tension adjustment cylinder to apply tension to the crawler belt between the idler wheel and the drive wheel. Applies to equipment.

The first aspect of the present invention is characterized in that a quick coupling is provided between the yoke and the tension adjusting cylinder to integrally connect the yoke and the tension adjusting cylinder. is there.

[0015] With this configuration, the yoke and the tension adjusting cylinder can be integrally connected via the quick coupling.
Even if a load other than the front and rear directions is applied, such as upward, downward, left, and right, the relative displacement of the yoke and the tension adjustment cylinder can be prevented, and the idler wheels can be stabilized for a long period of time. Can be supported.

After the yoke and the tension adjusting cylinder are individually assembled in the side frame, the yoke and the tension adjusting cylinder can be connected in the side frame by using a quick coupling, so that workability during the assembly can be improved. it can.

Further, in the invention according to claim 2, the quick joint is provided on a concave joint provided on one member of the yoke and the tension adjusting cylinder and on the other member of the yoke and the tension adjusting cylinder. It is composed of a convex joint fitted with the concave joint, and an engaging member removably engaging between the concave joint and the convex joint.

Thus, the concave joint provided on one of the yoke and the tension adjusting cylinder is fitted with the convex joint provided on the other member, and the engagement between the concave joint and the convex joint is established. The yoke and the tension adjusting cylinder can be integrally connected only by detachably engaging with the member.

Furthermore, the invention according to claim 3 is characterized in that the quick joint is provided on one of the yoke and the tension adjusting cylinder, and has a concave joint formed with a ball receiving hole penetrating from the outer peripheral side to the inner peripheral side. And a convex joint provided on the other member of the yoke and the tension adjusting cylinder, wherein an annular concave groove is provided at a position corresponding to the ball receiving hole when fitted to the concave joint; A ball engaged with the ball receiving hole and the annular groove of the convex joint, a sleeve fitted to the outer peripheral side of the concave joint, and retaining the ball between the annular groove and the sleeve; Provided on the inner peripheral side of the concave joint, and when the convex joint is not fitted to the concave joint, holds the ball between the sleeve and the sleeve,
And a ball holding sleeve that moves in the axial direction when the convex joint is fitted to the concave joint and allows the ball to engage with the annular groove.

Thus, the convex joint provided on one member of the yoke and the tension adjusting cylinder is fitted with the convex joint provided on the other member, and the ball receiving hole of the concave joint and the annular groove of the convex joint are fitted. The yoke and the tension adjusting cylinder can be integrally connected only by fitting the sleeve to the outer peripheral side of the concave joint and stopping the ball in a state where the ball is engaged with the yoke. In this case, when the convex joint is not fitted to the concave joint, the ball is held in the ball receiving hole of the concave joint by the ball holding sleeve, and when the convex joint is fitted to the concave joint, the ball holding sleeve Is pushed by this convex joint and moves in the axial direction,
Since the ball automatically engages the annular groove of the convex joint,
The yoke and the tension adjusting cylinder can be connected quickly and easily.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a crawler belt tensioning device according to the present invention will be described in detail below with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a track frame constituting a lower traveling body of a hydraulic excavator. The track frame 1 includes a center frame 2 on which an upper revolving body (not shown) is pivotably mounted, and Left of frame 2,
Side frames 3 (only one is shown) are provided on both right sides and extend in the front and rear directions.

Here, as shown in FIGS. 2 and 3, the side frame 3 is formed as a rectangular cylinder having a substantially quadrangular cross-sectional shape, and a cylindrical body 4 is provided therein via support plates 5 and 6. Fixed. An idle wheel bracket 7 is provided on one end side (front end side) of the side frame 3, and the idle wheel bracket 7 is connected to the front end of the side frame 3 by being fixedly connected thereto as shown in FIG. Plate 7A and left and right side plates 7B protruding forward from the connection end plate 7A.
7B and the like.

Numerals 8, 8 are concave groove-shaped guide portions provided on both the left and right sides in the idler wheel bracket 7, and these guide portions 8 are, as shown in FIG.
B, which is formed between an upper guide plate 8A and a lower guide plate 8B having an L-shaped cross section and extending forward and rearward along the idler wheel bracket 7, and having a yoke 16 to be described later moved forward and rearward. It is movably supported.

Reference numeral 9 denotes an idler wheel provided at one end of the side frame 3. The idler wheel 9 is rotatably supported by bearings 16C, which will be described later, of a yoke 16 via a rotating shaft 9A. Guide part 8 of idler bracket 7
Along the front and rear directions.

Reference numeral 10 denotes a drive wheel rotatably provided on the other end (rear end) of the side frame 3 by using a drive wheel side bracket 11, and the drive wheel 10 is a traveling wheel provided on a lower traveling body. Hydraulic motor (not shown).

Reference numeral 12 denotes a crawler belt wound around the idler wheel 9 and the drive wheel 10. The crawler belt 12 is guided by a plurality of upper rollers 13 and lower rollers 14 provided on the side frame 3. The crawler belt 12 is circulated between the driving wheel 10 and the idler wheel 9 via the driving wheel 10 by a traveling motor or the like, and causes the hydraulic shovel to travel.

Reference numeral 15 denotes a crawler belt tension adjusting device provided between the side frame 3 and the idler wheel 9. As shown in FIG. 3, the crawler belt tension adjuster 15 includes an idler wheel 9, a yoke 16, and a tension adjusting cylinder 17 as shown in FIG. , A compression spring 25, etc., for adjusting the tension of the crawler belt 12 between the idler wheel 9 and the drive wheel 10.

Reference numeral 16 denotes a yoke disposed in the idler wheel bracket 7. The yoke 16 includes a pair of left and right arms 16A, 16A extending forward and rearward with the idler wheel 9 interposed therebetween. A connecting portion 16B connecting the base ends of the arms 16A and each arm 1
It comprises bearing portions 16C, 16C provided on the tip side of 6A, and is formed in a substantially U-shape as a whole. And
Each bearing portion 16C is provided with an upper guide plate 8 of the idler wheel bracket 7.
A and the lower guide plate 8B are fitted to each other so that the yoke 16 can move forward and backward along the guide portion 8.

Reference numeral 17 denotes a tension adjusting cylinder disposed in the side frame 3. The tension adjusting cylinder 17 projects from the front end of the tube 18 having a tube 18 having a flange portion 18A for receiving a spring. Tube 1
A piston 20 defining a grease chamber 19 in the inside of the tube 8 and a rod 21 projecting from the rear end of the tube 18 toward the support plate 6
It is composed of Here, a disc-shaped spring receiving plate 22 is slidably inserted around the outer periphery of the protruding end of the rod 21,
The spring receiving plate 22 is a nut 2 screwed to the rod 21.
The outer peripheral side is in contact with the support plate 6 while being prevented from coming off in the axial direction by 3. A grease passage (not shown) for supplying grease to the grease chamber 19 of the tube 18 is bored in the rod 21 in the axial direction.
A grease nipple 24 is provided on the protruding end side of 1.

Then, the tension adjusting cylinder 17 is
When adjusting the tension of 2, the grease nipple 24 and the rod 21
Grease chamber 19 of tube 18 through the grease passage of
The idler 9 is moved forward and backward through the yoke 16 by supplying and discharging grease to and from the tube 18, and the crawler belt 12 is moved between the idler 9 and the drive wheel 10. The initial tension is adjusted.

Reference numeral 25 denotes a compression spring disposed between the flange portion 18A of the tube 18 and the spring receiving plate 22. The compression spring 25 is located in the cylindrical body 4 and has a tension adjusting cylinder 1
7, and urges the tension adjusting cylinder 17 toward the yoke 16. The compression spring 25 presses the idler wheel 9 in a direction away from the drive wheel 10, thereby giving the crawler belt 12 an appropriate tension.

26 is a yoke 16 and a tension adjusting cylinder 17
This quick coupling 26 is provided between
As shown in FIGS. 5 and 6, a concave joint 27 described below,
It comprises a convex joint 28, a plurality of balls 29, a locking sleeve 30, a ratchet sleeve 33, and the like. The concave joint 27 and the convex joint 28 are detachably engaged with each other using the balls 29 and the like. .

Reference numeral 27 denotes a cylindrical joint having a bottom and provided integrally with the connecting portion 16 B of the yoke 16 and projecting toward the tension adjusting cylinder 17. A convex joint 28 is fitted on the inner peripheral side of the concave joint 27. It is a fitting hole 27A that fits. Further, the concave joint 27 has a plurality of ball accommodation holes 27B formed to penetrate from the outer peripheral side to the inner peripheral side and accommodate the ball 29 therein.
(Only two are shown) are drilled at equal intervals in the circumferential direction.

28 is a piston 2 of the tension adjusting cylinder 17
0 A convex joint integrally provided on the distal end side, the convex joint 2
Numeral 8 is formed in a stepped cylindrical shape having a smaller diameter than the piston 20 and fits into the fitting hole 27A of the concave joint 27. Here, in the axially intermediate portion of the convex joint 28, an arc-shaped annular concave groove 28A is formed over the entire circumference at a position corresponding to each ball accommodation hole 27B when fitted to the concave joint 27, On the front side of the annular concave groove 28A, an annular convex portion 28B that engages with a ratchet sleeve 33 described later is formed over the entire circumference.

Numerals 29, 29 denote a plurality of (only two balls are shown) as engaging members accommodated in the respective ball accommodating holes 27B of the concave joint 27. As shown in FIG. The ball receiving hole 27B of the joint 27 and the convex joint 28
By engaging with the annular concave groove 28A of the
7 and the convex joint 28 are detachably connected to each other.

Numeral 30 denotes a locking sleeve fitted on the outer peripheral side of the concave joint 27. The locking sleeve 30 is formed in a cylindrical shape, and a ball 29 is provided on the inner peripheral side.
An annular projection 30A is provided to protrude over the entire circumference. Here, the locking sleeve 30 is provided with the concave joint 2.
7 is movably fitted to the outer peripheral side. The locking sleeve 30 is axially stopped by a stopper 31 provided on the protruding end side of the concave joint 27 and positioned by a locking ring 31A. Reference numeral 32 denotes a compression spring which is located on the outer peripheral side of the concave joint 27 and is provided between the locking sleeve 30 and the concave joint 27. The compression spring 32 constantly urges the locking sleeve 30 toward the stopper 31. It is.

Then, the locking sleeve 30 is used as shown in FIG.
When the convex joint 28 is fitted into the fitting hole 27A of the concave joint 27, the compression spring 32 holds the convex joint 28 at the position where it abuts against the stopper 31, as shown in FIG. The ball 2 between the annular groove 28A of the joint 28
9 is to be retained.

Reference numeral 33 denotes a ratchet sleeve as a ball holding sleeve which is movably inserted into the bottom of the fitting hole 27A of the concave joint 27. A stepped portion on the outer peripheral surface of the ratchet sleeve 33 is engaged with the ball 29. Are formed.

Numeral 34 designates the ratchet sleeve 33 with the ball 2
9, a compression spring biasing in a direction to engage with the compression spring 3.
4 is elastically provided between the bottom of the fitting hole 27A of the concave joint 27 and the ratchet sleeve 33.

When the convex joint 28 is not fitted in the fitting hole 27A of the concave joint 27, the ratchet sleeve 33 is moved toward the open end of the concave joint 27 by the compression spring 34 as shown in FIG. The ball 29 is pressed by the ratchet sleeve 33 in the direction in which the ball 29 protrudes from the ball receiving hole 27B. As a result, the ball 29 is engaged with the step of the annular convex portion 30A provided on the locking sleeve 30, and the compression spring 32 is contracted, and the inner peripheral surface of the locking sleeve 30 and the outer peripheral surface of the ratchet sleeve 33 are By sandwiching the ball 29 between the
Is held in the ball accommodation hole 27B of the concave joint 27.

On the other hand, when the convex joint 28 is fitted in the fitting hole 27A of the concave joint 27, the annular convex portion 28B of the convex joint 28 is fitted to the ratchet sleeve 33 as shown in FIG.
Are engaged, and the ratchet sleeve 33 is
To the bottom of the fitting hole 27A in the axial direction. As a result, the ball 29 engages with the annular groove 28A of the convex joint 28 while being held in the ball accommodation hole 27B of the concave joint 27.

The crawler belt tension adjusting device according to the present embodiment has the above-described configuration. Hereinafter, the operation of attaching this crawler belt tension adjusting device 15 to the side frame 3 will be described.

First, as shown in FIG. 7, the tension adjusting cylinder 17 and the compression spring 25 are inserted into the side frame 3 through the hole 7C formed in the connection end plate 7A of the idle wheel bracket 7, and Housed in

Next, the ball 29, the locking sleeve 30, the ratchet sleeve 33 and the like are attached to the concave joint 27 of the yoke 16, and the idler wheel 9 is attached to the bearing 16C of the yoke 16. Then, the yoke 16 is moved to the tension adjusting cylinder 17 side along the guide portion 8 of the idle wheel bracket 7, and as shown in FIG. 8, is inserted into the fitting hole 27 A of the concave joint 27 provided on the yoke 16 side. The tip of the convex joint 28 provided on the tension adjusting cylinder 17 side is inserted.

Then, the crawler belt 12 is wound between the idler wheel 9 and the drive wheel 10 with the tip of the convex joint 28 inserted into the fitting hole 27A of the concave joint 27. In this state, a grease gun (not shown) or the like is inserted into the side frame 3 through the working hole 3A provided in the side frame 3, and grease is injected from the grease nipple 24 into the grease chamber 19 of the tension adjusting cylinder 17.

As a result, the piston 20 protrudes from the tube 18 of the tension adjusting cylinder 17, and the annular convex portion 28 B of the convex joint 28 connects the ratchet sleeve 33 to the compression spring 3.
4 to the yoke 16 side. This allows
As shown in FIG. 5, the ball 29 is engaged with the annular groove 28A of the convex joint 28 while being held in the ball accommodation hole 27B of the concave joint 27.

When the ball 29 separates from the annular projection 30A of the locking sleeve 30, the compression spring 32 presses the locking sleeve 30 toward the stopper 31.
The locking sleeve 30 is held at a position where it abuts against the stopper 31, and the ball 29 is prevented from being removed between the annular convex portion 30A of the locking sleeve 30 and the annular concave groove 28A of the convex joint 28.

Thus, the ball receiving hole 2 of the concave joint 27 is
The ball 29 accommodated in the ball accommodation hole 2B
7B and the annular groove 28A of the convex joint 28 are detachably engaged, and the yoke 16 and the tension adjusting cylinder 17 can be integrally connected.

Then, the yoke 16 and the tension adjusting cylinder 1
7 and the tension adjusting cylinder 1
By injecting grease into the grease chamber 19 of the yoke 7, the piston 20 protruding from the tube 18 is
Press 6. Thereby, the idler wheel 9 supported by the yoke 16 moves in a direction away from the drive wheel 10, and the tension of the crawler belt 12 can be adjusted between the idler wheel 9 and the drive wheel 10.

Also, for example, during maintenance, the yoke 16
Is removed from the tension adjusting cylinder 17, first, after removing the crawler belt 12 from between the idler wheel 9 and the drive wheel 10,
While pressing the idler wheel 9 against the crawler tension adjusting device 15 side, loosen the bolt of the grease nipple 24, discharge the grease in the grease chamber 19, and push the piston 20 in.
The yoke 16 is pulled together with the idler wheel 9 in a direction away from the tension adjusting cylinder 17 while moving the locking sleeve 30 toward the base end of the concave joint 27 against the compression spring 32. As a result, the ball 29 is detached from the annular groove 28A of the convex joint 28, so that the concave joint 27 and the convex joint 28
Can be easily released, and the work of removing the yoke 16 during maintenance can be easily performed.

Next, the operation of the crawler belt tension adjusting device 15 according to the present embodiment will be described. First, the crawler belt 12 is bent according to the ups and downs of the ground when the hydraulic excavator is running. When a load acts on the yoke 16 and the tension adjusting cylinder 17, the load is received by the compression spring 25 via the yoke 16, the tension adjusting cylinder 17, and the like. Displace to. When the rearward load acting on the idler wheel 9 as the crawler belt 12 passes through the undulations and the like decreases, the compression spring 25 expands, and the idler wheel 9 is moved to the yoke 1.
6. Move forward together with the tension adjusting cylinder 17.

As described above, when a forward or backward load is applied to the idler wheel 9 due to the deflection of the crawler belt 12 during running of the hydraulic excavator, the compression spring 25 expands and contracts in accordance with the increase or decrease of the load. The crawler belt 12 maintains an appropriate tension between the idler wheel 9 and the drive wheel 10 by moving the tension adjusting cylinder 17 forward and backward with the yoke 16 and the idler wheel 9 according to the expansion and contraction of the spring 25. can do.

In this case, the yoke 16 for supporting the idler wheel 9
The tension adjusting cylinder 17 is connected to the tension adjusting cylinder 17 by a quick coupling 26 in a state close to a single rigid body. Even if loads such as upward, downward, left, and right are applied, the yoke 16 and the tension adjusting cylinder 17 are relatively displaced so as to be bent in a “C” shape with respect to the front and rear axes. Can be prevented.

For this reason, the yoke 16, the tension adjusting cylinder 17, or the idle wheel bracket 7 for supporting the yoke 16 movably in the front and rear directions can be prevented from being worn or damaged at an early stage. Since the idler wheel 9 can be stably supported for a long period against loads acting from above, below, left, right, etc. other than the rearward direction, the hydraulic excavator including the crawler belt tension adjusting device 15 can be supported. Overall durability,
Reliability can be improved.

Moreover, the yoke 16 and the tension adjusting cylinder 1
7 can be integrally connected to each other by the quick coupling 26 in the side frame 3 after being individually incorporated in the side frame 3.
Workability during assembling can be greatly improved as compared with a case where the yoke 16 and the tension adjusting cylinder 17 are assembled in advance as a sub-assembly body, and this sub-assembly body is assembled in the side frame 3.

Incidentally, for example, as in a modification shown in FIG.
When a plurality of hooks 41 are protruded on the outer peripheral side of the locking sleeve 30, the wire 42 hooked on the hook 41
By moving the yoke 16 in a direction away from the tension adjusting cylinder 17 while pulling the
The connection between the yoke 16 and the tension adjusting cylinder 17 can be released.
Can be performed more easily.

In the above-described embodiment, the crawler belt tension adjusting device 15 is connected to the concave joint 27 by the connecting portion 16 of the yoke 16.
B, and the case where the convex joint 28 is provided on the piston 20 of the tension adjusting cylinder 17 has been described as an example. However, the present invention is not limited to this. For example, as in another modification shown in FIG. The concave joint 27 is provided on the piston 20 of the tension adjusting cylinder 17, and the convex joint 28 is connected to the connecting portion 16 </ b> B of the yoke 16.
May be provided.

Further, in the above-described embodiment, the case where the crawler belt tension adjusting device 15 is applied to a hydraulic shovel is described as an example. However, the present invention is not limited to this, and for example, a hydraulic crane,
The present invention may be applied to other tracked vehicles such as bulldozers, and further to agricultural machines and industrial machines provided with crawler tracks.

[0060]

As described above in detail, according to the first aspect of the present invention, a quick joint for integrally connecting the yoke and the tension adjusting cylinder is provided between the yoke and the tension adjusting cylinder. , The yoke and the tension adjusting cylinder can be connected in a state close to a single rigid body via a quick coupling, and loads other than front and rear, such as up, down, left, and right, act on the idler wheel. Also, it is possible to prevent the yoke and the tension adjusting cylinder from being relatively displaced in a tilted manner. This allows
The yoke, the tension adjusting cylinder, and the members for supporting the yoke movably in the front and rear directions can be prevented from being worn or damaged early, and the idle wheel can be stably supported for a long period of time. Therefore, the durability and reliability of the crawler belt tension adjusting device can be improved.

Further, the yoke and the tension adjusting cylinder are
After individually assembled in the side frame, it can be connected in the side frame by using a quick coupling.For example, when assembling an integrated idler wheel, yoke, tension adjusting cylinder, etc. in the side frame In comparison, workability at the time of assembly can be greatly improved.

According to the second aspect of the present invention, the concave joint provided on one member of the yoke and the tension adjusting cylinder is fitted with the convex joint provided on the other member, and the concave joint and the convex joint are provided. The yoke and the tension adjusting cylinder can be integrally connected only by detachably engaging the shape joint with the engaging member, and the connecting operation can be performed quickly and easily.

Further, according to the third aspect of the present invention, the concave joint provided on one member of the yoke and the tension adjusting cylinder is fitted with the convex joint provided on the other member, and the ball receiving hole of the concave joint is provided. When the ball is engaged with the annular groove of the convex joint and the sleeve is fitted to the outer peripheral side of the concave joint and the ball is prevented from coming off, the yoke and tension adjusting cylinder are integrally connected. can do. In this case, when the convex joint is not fitted to the concave joint, the ball is held in the ball receiving hole of the concave joint by the ball holding sleeve, and when the convex joint is fitted to the concave joint, the ball is automatically moved. The yoke and the tension adjusting cylinder can be quickly and easily connected to each other because they are engaged with the annular groove.

[Brief description of the drawings]

FIG. 1 is a front view showing a lower traveling body of a hydraulic shovel to which a crawler belt tension adjusting device according to an embodiment of the present invention is applied.

FIG. 2 is an enlarged view of a main part showing an idler wheel, a crawler belt, a crawler belt tension adjusting device and the like in FIG. 1 which constitute one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a yoke, a tension adjusting cylinder, a quick coupling, and the like, which constitute one embodiment of the present invention, as viewed from the direction of arrows III-III in FIG.

4 is a longitudinal sectional view showing an idler wheel, an idler wheel bracket, and the like, which constitute one embodiment of the present invention, as viewed from a direction indicated by arrows IV-IV in FIG. 2;

FIG. 5 is an enlarged cross-sectional view showing an enlarged quick coupling constituting one embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view showing a state in which a concave joint and a convex joint of the quick joint constituting one embodiment of the present invention are separated from each other.

FIG. 7 is a cross-sectional view similar to FIG. 3, but showing a state before connecting a yoke and a tension adjusting cylinder.

FIG. 8 is an enlarged cross-sectional view similar to FIG. 5, showing a state in which the tip of the convex joint is being inserted into the concave joint of the quick joint.

FIG. 9 is a cross-sectional view similar to FIG. 3, showing a modification of the quick coupling having a hook provided on a locking sleeve.

FIG. 10 is an enlarged sectional view similar to FIG. 5, showing another modification of the quick coupling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Track frame 3 Side frame 9 Idling wheel 10 Driving wheel 12 Crawler belt 15 Crawler belt tension adjusting device 16 Yoke 17 Tension adjusting cylinder 25 Compression spring 26 Rapid joint 27 Concave joint 27B Ball accommodation hole 28 Convex joint 28A Annular concave groove 29 Ball 30) Locking sleeve (sleeve) 33 Ratchet sleeve (ball holding sleeve)

Claims (3)

[Claims] 1. A yoke provided at one end of a side frame constituting a track frame and movable forward and backward, and provided at the other end of the side frame rotatably supported by the yoke. An idler wheel around which a crawler belt is wound around a drive wheel; a tension adjusting cylinder provided between the yoke and a side frame for adjusting front and rear tensions of the crawler belt; A crawler belt tension adjusting device comprising a compression spring provided between the side frame and a tension adjusting cylinder to provide tension to the crawler belt between the yoke and the tension adjusting cylinder; A crawler belt tension adjusting device, wherein a quick joint for integrally connecting a yoke and a tension adjusting cylinder is provided. 2. The quick coupling, which fits into a concave joint provided on one of the yoke and the tension adjusting cylinder and a concave joint provided on the other of the yoke and the tension adjusting cylinder. The crawler belt tension adjusting device according to claim 1, comprising a convex joint and an engaging member that detachably engages between the concave joint and the convex joint. 3. The joint according to claim 1, wherein the quick joint is provided on one of the yoke and the tension adjusting cylinder, and the concave joint has a ball receiving hole penetrating from an outer peripheral side to an inner peripheral side. A convex joint provided on the other member of the cylinder, wherein an annular concave groove is provided at a position corresponding to the ball accommodating hole when fitted to the concave joint; a ball accommodating hole of the concave joint; A ball engaged with the annular groove of the concave joint, fitted on the outer peripheral side of the concave joint,
A sleeve for retaining the ball between the annular groove and a sleeve provided on the inner peripheral side of the concave joint, wherein the convex joint is not fitted to the concave joint; 2. A ball holding sleeve for holding a ball and axially moving when the convex joint engages the concave joint to allow the ball to engage the annular groove. Crawler tension adjustment device.