JP7578524B2 - Work Machine - Google Patents

Description

The present invention relates to a crawler-type work machine.

Conventionally, crawler devices mounted on work machines mainly comprise drive and driven wheels supported on side frames at positions spaced apart in the fore-and-aft direction, tracks stretched between the drive and driven wheels, and guide rollers that rotate in contact with the inner circumferential surface of the tracks between the drive and driven wheels.

In addition to metal iron crawlers, there are also rubber crawlers (see, for example, Patent Document 1) for tracks. In some cases, the work machine is used by switching between iron crawlers and rubber crawlers depending on the conditions at the work site and the type of work being done.

JP 2008-126977 A

Since iron crawlers and rubber crawlers are made of different materials and have different structures, the optimal arrangement of the guide rollers also differs depending on the type of track. However, the work machine in Patent Document 1 is not configured to allow the arrangement of the guide rollers to be changed, so it is only possible to optimally arrange either the iron crawlers or the rubber crawlers.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a work machine in which the arrangement of the guide rollers can be easily changed.

In order to achieve the above object, the present invention provides a working machine comprising a vehicle body having a center frame and a pair of side frames located at both left and right ends of the center frame, and a crawler device supported by each of the pair of side frames and rotating to move the vehicle body forward and backward, the crawler device including a traveling motor, drive wheels supported at rear ends of the side frames and rotated by the driving force of the traveling motor, driven wheels rotatably supported at front ends of the side frames, tracks stretched between the drive wheels and the driven wheels, and guide rollers located between the drive wheels and the driven wheels and rotating in contact with an inner circumferential surface of the tracks, the crawler device being configured to move the vehicle body forward and backward ... The frame is provided with a support hole extending in the fore-and-aft direction and selectively fixing the guide roller to a front end position or a rear end position, and when the guide roller is released , it is configured to be movable in the fore-and-aft direction along the support hole between the front end position and the rear end position, and the guide roller is composed of a spindle having a bolt hole formed therein and a roller that is rotatably supported on the spindle and abuts the inner surface of the track, and when a bolt inserted into the support hole is tightened into the bolt hole, the side frame is clamped and fixed by the spindle and the bolt head, and when the bolt is loosened, the guide roller is configured to be movable along the support hole .

According to the present invention, the arrangement of the guide rollers can be easily changed. Problems, configurations, and effects other than those described above will become clear from the description of the following embodiment.

FIG. 2 is a side view of the hydraulic excavator. FIG. 13 is a rear view of the middle guide roller supported by the side frame. FIG. FIG. 4 is a diagram showing the positional relationship between a rubber crawler and a guide roller. FIG.

An embodiment of a hydraulic excavator 1 (working machine) according to the present invention will be described with reference to the drawings. Note that specific examples of the working machine are not limited to the hydraulic excavator 1, and may be wheel loaders, cranes, dump trucks, etc. Furthermore, unless otherwise specified, the terms front, back, left, right, and front in this specification are based on the viewpoint of an operator who is riding on and operating the hydraulic excavator 1.

Figure 1 is a side view of a hydraulic excavator 1. Figure 2 is a perspective view of a lower traveling body 2. As shown in Figure 1, the hydraulic excavator 1 includes a lower traveling body 2 (vehicle body) and an upper rotating body 3 supported by the lower traveling body 2.

As shown in FIG. 2, the lower traveling body 2 is composed of a center frame 8 and a pair of left and right side frames 9L, 9R. The center frame 8 is located in the center of the lower traveling body 2. The center frame 8 supports the upper rotating body 3 so that it can rotate via a rotating ring 8a. The side frames 9L, 9R are disposed at the left and right ends of the center frame 8. The side frames 9L, 9R extend in the front-rear direction. Each of the side frames 9L, 9R rotatably supports a crawler device 10.

As shown in FIG. 1, the upper rotating body 3 is supported on the lower running body 2 so as to be rotatable by a rotating motor (not shown). The upper rotating body 3 mainly comprises a rotating frame 5 serving as a base, a front work machine 4 (working device) attached to the front center of the rotating frame 5 so as to be rotatable in the vertical direction, a cab (operator's seat) 7 located on the front left side of the rotating frame 5, and a counterweight 6 located at the rear of the rotating frame 5.

The front work implement 4 includes a boom 4a supported on the upper rotating body 3 so that it can be raised and lowered, an arm 4b supported rotatably at the end of the boom 4a, a bucket 4c supported rotatably at the end of the arm 4b, a boom cylinder 4d that drives the boom 4a, an arm cylinder 4e that drives the arm 4b, and a bucket cylinder 4f that drives the bucket 4c. The counterweight 6 is used to balance the weight of the front work implement 4, and is a heavy object that has an arc shape when viewed from above.

The cab 7 defines an internal space in which an operator who operates the hydraulic excavator 1 sits. In the internal space of the cab 7, a seat on which the operator sits and an operating device operated by the operator seated on the seat are arranged. Note that while FIG. 1 illustrates an open cab 7 whose entrance and exit are always open, a closed cab whose entrance and exit can be opened and closed with a door may also be used.

The operating device receives operations from an operator to operate the hydraulic excavator 1. When the operator operates the operating device, the lower traveling body 2 travels, the upper rotating body 3 rotates, and the front working machine 4 operates. Specific examples of the operating device include a lever, a steering wheel, an accelerator pedal, a brake pedal, a switch, etc.

The crawler device 10 is supported by a pair of left and right side frames 9L, 9R. The left and right crawler devices 10 rotate independently to move the hydraulic excavator 1 forward, backward, and turn. The left and right crawler devices 10 have the same configuration, so the crawler device 10 supported by the left side frame 9L will be described in detail below. As shown in FIG. 1, the crawler device 10 mainly includes a travel motor 11, drive wheels 12, driven wheels 13, tracks 14, a front guide roller 15a, a middle guide roller 15b (guide roller), and a rear guide roller 15c (hereinafter, these may be collectively referred to as "guide rollers 15a to 15c").

The travel motor 11 is supported at the rear end of the side frame 9L. The travel motor 11 rotates (generates driving force) when hydraulic oil stored in a hydraulic oil tank (not shown) is supplied from a hydraulic pump (not shown).

The drive wheels 12 are rotatably supported at the rear end of the side frame 9L. The drive wheels 12 rotate by the driving force of the travel motor 11. The driven wheels 13 are rotatably supported at the front end of the side frame 9L. That is, the drive wheels 12 and the driven wheels 13 are rotatably supported on the side frame 9L at positions spaced apart in the front-rear direction.

The crawler belt 14 is configured in an endless annular belt shape. The crawler belt 14 is stretched across the drive wheels 12 and the driven wheels 13. The lower side of the crawler belt 14 (the portion between the lower ends of the drive wheels 12 and the driven wheels 13) comes into contact with the ground. The rotation of the drive wheels 12 is transmitted to the crawler belt 14, causing it to rotate between the drive wheels 12 and the driven wheels 13. The rotation of the crawler belt 14 is also transmitted to the driven wheels 13, causing them to rotate.

The crawler device 10 can be selectively fitted with either an iron track 14 (hereinafter referred to as an "iron crawler 14F") or a rubber track 14 (hereinafter referred to as a "rubber crawler 14G") depending on the application of the hydraulic excavator 1.

The guide rollers 15a to 15c are disposed between the driving wheels 12 and the driven wheels 13. The guide rollers 15a to 15c are rotatably supported by the side frame 9L at positions spaced apart in the fore-and-aft direction. The guide rollers 15a to 15c abut against the inner peripheral surface of the lower side of the crawler belt 14, thereby pressing the crawler belt 14 against the ground. The guide rollers 15a to 15c rotate in conjunction with the rotation of the crawler belt 14.

The front guide roller 15a is disposed forward of the middle guide roller 15b and the rear guide roller 15c. The middle guide roller 15b is disposed rearward of the front guide roller 15a and forward of the rear guide roller 15c. The rear guide roller 15c is disposed rearward of the front guide roller 15a and the middle guide roller 15b. However, the number of guide rollers 15a to 15c is not limited to three.

Next, the structure of the side frame 9L and the middle guide roller 15b, and the method of fixing the middle guide roller 15b to the side frame 9L will be described with reference to Figures 3 and 4. Figure 3 is a rear view of the middle guide roller 15b supported by the side frame 9L. Figure 4 is a side view of the side frame 9L.

As shown in FIG. 3, the side frame 9L has a generally inverted U-shaped exterior. More specifically, the side frame 9L is composed of an upper plate 9a extending in the front-rear direction, a right plate 9b protruding downward from the right end of the upper plate 9a and extending in the front-rear direction, and a left plate 9c protruding downward from the left end of the upper plate 9a and extending in the front-rear direction.

As shown in Figures 3 and 4(A), the side frame 9L (more specifically, the right plate 9b and the left plate 9c) has a front support hole 20, a middle support hole 21 (support hole), and a rear support hole 22 (hereinafter, these may be collectively referred to as "support holes 21-22") formed therein, which penetrate the side frame 9L in the thickness direction. The support holes 20-22 are spaced apart in the front-rear direction. The front support hole 20 and the rear support hole 22 are vertical holes that extend in the up-down direction. Meanwhile, the middle support hole 21 has a roughly U-shaped outer shape.

More specifically, the middle support hole 21 is composed of a horizontal hole 21a extending in the front-rear direction, a first vertical hole 21b extending upward from the front end of the horizontal hole 21a, and a second vertical hole 21c extending upward from the rear end of the horizontal hole 21a. In the vertical direction, the upper end positions of the first vertical hole 21b and the second vertical hole 21c coincide with the upper end positions of the front support hole 20 and the rear support hole 22.

The first vertical hole 21b is formed in a position closer to the front support hole 20 than the rear support hole 22 in the front-rear direction. On the other hand, the second vertical hole 21c is formed in a position closer to the rear support hole 22 than the front support hole 20 in the front-rear direction. However, it is preferable that the first vertical hole 21b is formed in a position equidistant from the front support hole 20 and the rear support hole 22 in the front-rear direction.

As shown in FIG. 3, the middle guide roller 15b is composed of a support shaft 16 and a roller 17 rotatably supported on the outer circumferential surface of the support shaft 16. In addition, bolt holes 16a, 16b are formed at both the left and right ends of the support shaft 16. The front guide roller 15a and the rear guide roller 15c also have the same structure.

The middle guide roller 15b is disposed between the right plate 9b and the left plate 9c. This allows the bolt hole 16a to communicate with the middle support hole 21 of the right plate 9b, and the bolt hole 16b to communicate with the middle support hole 21 of the left plate 9c. Spacers 18a and 18b are disposed on the outside of the right plate 9b and the left plate 9c. Then, bolts 19a and 19b inserted through the spacers 18a and 18b and the middle support hole 21 from the outside of the right plate 9b and the left plate 9c are screwed into the bolt holes 16a and 16b.

When the bolts 19a and 19b are tightened into the bolt holes 16a and 16b, the side frame 9L (more specifically, the right plate 9b and the left plate 9c) is clamped between the end face of the support shaft 16 and the bolt heads of the bolts 19a and 19b (more specifically, the spacers 18a and 18b). This fixes the middle guide roller 15b to the side frame 9L while allowing the roller 17 to rotate.

As shown in FIG. 4B, the middle guide roller 15b according to this embodiment is rotatably fixed to the side frame 9L at the upper end position of the first vertical hole 21b (i.e., the front end position of the middle support hole 21) or the upper end position of the second vertical hole 21c (i.e., the rear end position of the middle support hole 21). The front guide roller 15a and the rear guide roller 15c according to this embodiment are rotatably fixed to the side frame 9L at the upper end positions of the front support hole 20 and the rear support hole 22. As a result, the guide rollers 15a to 15c fixed to the side frame 9L have the same height H from the ground.

On the other hand, when the bolts 19a, 19b screwed into the bolt holes 16a, 16b are loosened (i.e., released), the middle guide roller 15b becomes movable in the front-rear direction along the middle support hole 21. More specifically, the bolts 19a, 19b are guided by the middle support hole 21, and the middle guide roller 15b becomes movable between the upper end position of the first vertical hole 21b and the upper end position of the second vertical hole 21c (i.e., between the front end position and the rear end position of the middle support hole 21).

In this embodiment, as shown in FIG. 4(B), when the middle guide roller 15b is fixed at the upper end position of the first vertical hole 21b, the distance P1 between the front guide roller 15a and the middle guide roller 15b in the front-to-rear direction is smaller than the distance P2 between the middle guide roller 15b and the rear guide roller 15c in the front-to-rear direction. However, it is preferable that the guide rollers 15a to 15c are arranged at equal intervals in the front-to-rear direction (i.e., P1 = P2). As a result, when the iron crawler 14F is attached to the crawler device 10, fixing the guide roller 15b at the upper end position of the first vertical hole 21b allows the iron crawler 14F to be pressed evenly against the ground.

Figure 5 shows the positional relationship between the rubber crawler 14G and the guide rollers 15a to 15c. Note that Figure 5(A) shows the state in which the middle guide roller 15b is fixed at the upper end position of the first vertical hole 21b. Meanwhile, Figure 5(B) shows the state in which the middle guide roller 15b is fixed at the upper end position of the second vertical hole 21c.

As shown in FIG. 5, convex portions 14a and concave portions 14b are arranged alternately in the circumferential direction on the inner peripheral surface of the rubber crawler 14G. On the other hand, although not shown, the inner peripheral surface of the iron crawler 14F does not have any structure equivalent to the convex portions 14a and concave portions 14b. And, when the rubber crawler 14G rotates, the guide rollers 15a to 15c that come into contact with the inner peripheral surface of the rubber crawler 14G ride over the multiple convex portions 14a that are arranged at a predetermined interval in the circumferential direction.

As shown in FIG. 5(A), when the rubber crawler 14G is attached to the crawler device 10 and the guide roller 15b is fixed at the top end of the first vertical hole 21b, the guide rollers 15a to 15c simultaneously climb onto the convex portion 14a at one time (dashed line) and simultaneously drop into the concave portion 14b at another time (solid line). At this time, the guide rollers 15a to 15c repeatedly change position by a height ΔH as the rubber crawler 14G rotates. This causes large vibrations when the hydraulic excavator 1 is traveling.

On the other hand, as shown in FIG. 5(B), when the rubber crawler 14G is attached to the crawler device 10, if the guide roller 15b is fixed at the upper end position of the second vertical hole 21c, when the guide rollers 15a and 15c ride up on the convex portion 14a, the guide roller 15b falls into the concave portion 14b. On the other hand, when the guide rollers 15a and 15c fall into the concave portion 14b, the guide roller 15b rides up on the convex portion 14a. In other words, the position of the second vertical hole 21c is the position where the guide roller 15b abuts against the other of the convex portion 14a and the concave portion 14b at the timing when the guide rollers 15a and 15c abut against one of the convex portion 14a and the concave portion 14b.

According to the above embodiment, the guide roller 15b can move in the front-rear direction along the middle support hole 21, and the guide roller 15b is selectively fixed rotatably to the front end position and the front end position of the middle support hole 21, so the position of the guide roller 15b can be easily changed. As a result, the guide rollers 15a to 15c can be positioned in optimal positions according to the type of crawler belt 14.

As one example, when an iron crawler 14F is attached to the crawler device 10, the guide rollers 15a to 15c can be arranged at equal intervals to press the iron crawler 14F evenly. As another example, when a rubber crawler 14G is attached to the crawler device 10, the guide rollers 15a to 15c can be arranged so that they do not simultaneously climb onto the convex portion 14a or fall into the concave portion 14b, thereby suppressing vibrations while the hydraulic excavator 1 is traveling.

In addition, according to the above embodiment, by selectively fixing the guide roller 15b to the front end position and rear end position of the U-shaped middle support hole 21, the guide roller 15b can be appropriately supported against the upward force applied to the guide roller 15b from the crawler belt 14. Also, the same effect can be obtained by supporting the guide rollers 15a, 15c at the upper end positions of the front support hole 20 and the rear support hole 22.

The middle support hole 21 is not limited to a U-shape. As another example, the middle support hole 21 in FIG. 4(A) may be inverted 180 degrees to form a lowercase n-shape. As yet another example, the first vertical hole 21b and the second vertical hole 21c may be omitted, and the middle support hole 21 may be formed only by the horizontal hole 21a. In the above embodiment, only the central guide roller 15b is movable in the front-rear direction, but the guide rollers 15a and 15b may be configured to be movable in the front-rear direction.

The above-described embodiments are illustrative examples of the present invention, and are not intended to limit the scope of the present invention to these embodiments. Those skilled in the art may implement the present invention in various other forms without departing from the spirit of the present invention.

1 Hydraulic excavator 2 Lower travelling body 3 Upper rotating body 4 Front working machine 4a Boom 4b Arm 4c Bucket 4d Boom cylinder 4e Arm cylinder 4f Bucket cylinder 5 Swivel frame 6 Counterweight 7 Cab 8 Center frame 8a Swivel wheels 9L, 9R Side frame 9a Upper plate 9b Right plate 9c Left plate 10 Crawler device 11 Travel motor 12 Drive wheel 13 Driven wheel 14 Track 14F Iron crawler 14G Rubber crawler 14a Convex portion 14b Concave portion 15a Front guide roller 15b Middle guide roller (guide roller)
15c rear guide roller 16 support shaft 16a, 16b bolt hole 17 roller 18a, 18b spacer 19a, 19b bolt 20 front support hole 21 middle support hole (support hole)
21a: Horizontal hole 21b: First vertical hole 21c: Second vertical hole 22: Rear support hole

Claims (3)

A vehicle body having a center frame and a pair of side frames located on both left and right ends of the center frame;
a crawler device supported by each of the pair of side frames and rotating to move the vehicle body forward and backward;
The crawler device is a working machine including a travel motor, a drive wheel supported on a rear end of the side frame and rotated by a driving force of the travel motor, a driven wheel rotatably supported on a front end of the side frame, a track stretched between the drive wheel and the driven wheel, and a guide roller positioned between the drive wheel and the driven wheel and rotating in contact with an inner peripheral surface of the track,
The side frame is provided with a support hole extending in the front-rear direction and selectively fixing the guide roller at a front end position or a rear end position,
the guide roller is configured to be movable in a front-rear direction along the support hole between the front end position and the rear end position when the guide roller is released from the fixed state ,
a work machine characterized in that the guide roller is composed of a support shaft having a bolt hole formed therein, and a roller rotatably supported on the support shaft and abutting the inner circumferential surface of the crawler belt, and that when a bolt is inserted into the support hole and tightened into the bolt hole, the support shaft and bolt head clamp and fix the side frame, and when the bolt is loosened, the guide roller is movable along the support hole . A vehicle body having a center frame and a pair of side frames located on both left and right ends of the center frame;
a crawler device supported by each of the pair of side frames and rotating to move the vehicle body forward and backward;
The crawler device is a working machine including a travel motor, a drive wheel supported on a rear end of the side frame and rotated by a drive force of the travel motor, a driven wheel rotatably supported on a front end of the side frame, a track stretched between the drive wheel and the driven wheel, a guide roller positioned between the drive wheel and the driven wheel and rotating in contact with an inner peripheral surface of the track , a front guide roller positioned forward of the guide roller, and a rear guide roller positioned rearward of the guide roller ,
The side frame is provided with a support hole extending in the front-rear direction and selectively fixing the guide roller at a front end position or a rear end position,
the guide roller is configured to be movable in a front-rear direction along the support hole between the front end position and the rear end position when the guide roller is released from the fixed state ,
The inner circumferential surface of the crawler belt has convex portions and concave portions alternately arranged thereon,
one of the front end position and the rear end position of the support hole is formed at a position equidistant from the front guide roller and the rear guide roller,
the other of the front end position and the rear end position of the support hole is formed at a position where, when the front guide roller and the rear guide roller are in contact with the convex portion, the guide roller abuts against the concave portion, and, when the front guide roller and the rear guide roller are in contact with the concave portion, the guide roller abuts against the convex portion . 3. The working machine according to claim 1 or 2 ,
The support hole is composed of a horizontal hole extending in the front-rear direction, a first vertical hole extending upward from a front end of the horizontal hole, and a second vertical hole extending upward from a rear end of the horizontal hole,
A work machine characterized in that the guide rollers are fixed at upper end positions of the first vertical hole and the second vertical hole.

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