JP6689767B2 - Tracked vehicle - Google Patents

Description

  The present invention relates to a tracked vehicle equipped with a crawler track that is preferably used as a construction machine such as a hydraulic excavator and a hydraulic crane.

  In general, tracked vehicles such as hydraulic excavators and hydraulic cranes are equipped with a self-propelled track-type undercarriage, an upper revolving structure rotatably mounted on the lower traveling structure, and an upper revolving structure. It is composed of a work device that is provided so as to be possible.

  The track-type undercarriage has a track frame composed of a center frame and side frames extending in the front and rear directions on both left and right sides of the center frame, and front and rear side frames of the left and right side frames. The idler wheel provided on one end side in the direction, the drive wheel provided on the other end side in the front and rear directions of each side frame and driven by a hydraulic motor, etc., and wound between the idler wheel and the drive wheel. A crawler belt provided, partition walls provided in each side frame apart from the idler wheel to the drive wheel side, and a crawler belt tension adjusting device provided between the partition wall and the idler wheel to adjust the tension of the crawler belt. Has been.

  The crawler belt tension adjusting device includes a yoke movably mounted in a side frame in a front and rear direction and having a floating wheel attached thereto, a tension adjusting cylinder provided between the partition wall and the yoke, and a spring bearing of the tension adjusting cylinder. And a spring member provided between the spring receiving portion of the yoke and biasing the yoke in a direction away from the drive wheel (see, for example, Patent Document 1).

JP, 2006-088766, A

  By the way, when the crawler belt tension adjusting device is assembled in the side frame, the crawler belt tension adjusting device and the idler wheel are inserted from one side in the front or rear direction of the side frame with the bolts fastened. In this case, the tip end side (tension adjusting cylinder side) of the crawler belt tension adjusting device may be tilted downward by its own weight due to the manufacturing tolerance of the insertion part of the side frame into which the crawler belt tension adjusting device is inserted and the crawler belt tension adjusting device.

  Here, in the above-mentioned Patent Document 1, a spring support plate that supports the lower side of the spring member is provided in the side frame. Therefore, when the crawler belt tension adjusting device is assembled in the side frame, the spring member may come into contact with (interfere with) the spring support plate and the life of the spring member may be shortened. If the side frame is not provided with a spring support plate, the spring member may come into contact with a member in the side frame, a lower roller for guiding the crawler belt, etc., and the life of the spring member may be shortened.

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a tracked vehicle capable of suppressing a decrease in the life of the spring member of the crawler belt tension adjusting device. is there.

In order to solve the above-mentioned problems, the present invention provides a side frame that constitutes a track frame and extends in the front and rear directions, an idler wheel provided on one end side in the front and rear directions of the side frame, and the side frame. A drive wheel provided on the other end side in the front and rear directions, a crawler belt wound around the idler wheel and the drive wheel, and a side track in the side frame separated from the idler wheel to the drive wheel side. And a crawler belt tension adjusting device provided between the partition wall and the idler wheel for adjusting the tension of the crawler belt. And a tension adjustment cylinder provided between the partition wall and the yoke, a spring bearing portion of the tension adjustment cylinder, and a spring bearing portion of the yoke. Set between And a spring member that biases the yoke in a direction away from the drive wheel, the track tension adjusting device is provided with a spring protection cover that covers the spring member from below. The spring protection cover includes one side spring protection cover disposed on one end side in the front and rear directions of the spring member, and another side spring protection cover disposed on the other end side in the front and rear directions of the spring member. The one-side spring protection cover includes a one-side sandwiching plate sandwiched between one end of the spring member in the front and rear directions and a spring receiving portion of the yoke, and the one-side sandwiching plate. The one side spring cover plate that is fixed and curves in an arc shape along the outer peripheral surface of the spring member to cover the lower side of the spring member, and the other side spring protection cover is provided in front of and behind the spring member. Direction and the tension adjusting cylinder The other side holding plate sandwiched between the receiving part and the other side spring cover fixed to the other side holding plate and curved in an arc shape along the outer peripheral surface of the spring member while covering the lower side of the spring member. It is characterized in that it is composed of a plate .
Further, the present invention provides a side frame that constitutes a track frame and extends in the front and rear directions, an idler wheel provided on one end side in the front and rear directions of the side frame, and a front and rear direction other than the side frame. A drive wheel provided on an end side, a crawler belt wound around the idler wheel and the drive wheel, and a partition wall provided in the side frame apart from the idler wheel to the drive wheel side. A crawler belt tension adjusting device provided between the partition wall and the idler wheel for adjusting the tension of the crawler belt, the crawler belt tension adjusting device being provided in the side frame so as to be movable in the front and rear directions. And a tension adjusting cylinder provided between the partition wall and the yoke, and a spring receiving portion of the tension adjusting cylinder and a spring receiving portion of the yoke. York above In a tracked vehicle including a spring member biasing in a direction away from the driving wheel, the track tension adjusting device is provided with a spring protection cover that covers the spring member from below, and the spring protection cover. Is composed of one side spring protection cover arranged on one end side in the front and rear direction of the spring member, and another side spring protection cover arranged on the other end side in the front and rear direction of the spring member, The one-side spring protection cover includes a one-side mounting plate detachably attached to a spring receiving portion of the yoke by using a fastener, and a circle fixed along the one-side mounting plate along an outer peripheral surface of the spring member. The one side spring cover plate that curves in an arc shape and covers the lower side of the spring member, and the other side spring protection cover is detachably attached to the spring receiving portion of the tension adjusting cylinder by using a fastener. Other side mounting plate and the other side It is characterized in that is constituted by the other side spring cover plate for covering the lower side of the spring member is fixed to the biasing plate while curved in an arc shape along the outer peripheral surface of the spring member.

  According to the present invention, it is possible to prevent the life of the spring member of the crawler belt tension adjusting device from decreasing.

1 is a front view showing a hydraulic excavator according to a first embodiment of the present invention. It is a front view which expands and shows the lower traveling body in FIG. It is the perspective view which saw the track frame alone. FIG. 7 is a cross-sectional view showing the inside of the side frame with the crawler belt tension adjusting device tilted downward when the crawler belt tension adjusting device is assembled in the side frame. FIG. 5 is a cross-sectional view of the side frame, the lower roller, the crawler belt tension adjusting device, and the one-side spring cover plate as viewed in the direction of the arrow VV in FIG. 4. FIG. 6 is a cross-sectional view of a side frame, a lower roller, a crawler belt tension adjusting device, and a spring cover plate on the other side as viewed in the direction of arrows VI-VI in FIG. 4. It is a perspective view showing the state where one side spring cover board and the other side spring cover board were attached to a crawler belt tension adjusting device. FIG. 6 is an enlarged cross-sectional view of a main part showing a state where the bearing portion of the yoke is tilted downward with respect to the idle wheel bracket. FIG. 8 is a sectional view similar to FIG. 4, showing a crawler belt tension adjusting device, a one-side spring cover plate, and another-side spring cover plate according to a second embodiment of the present invention. It is a perspective view which shows the state which attached the one side spring cover board to the yoke. It is a perspective view showing the state where the other side spring cover plate was attached to the tension adjustment cylinder. FIG. 9 is a sectional view similar to FIG. 4, showing a crawler belt tension adjusting device, a one-side spring cover plate, and another-side spring cover plate according to a modified example of the present invention.

  Hereinafter, as a tracked vehicle according to an embodiment of the present invention, a hydraulic excavator provided with a track-type lower traveling body will be described as an example in detail with reference to the accompanying drawings.

  First, FIGS. 1 to 8 show a first embodiment of the present invention. In FIG. 1, a hydraulic excavator 1 includes a self-propelled track-type (crawler type) lower traveling body 2, an upper revolving body 3 rotatably mounted on the lower traveling body 2, and an upper revolving body. 3 and a working device 4 provided on the front side of the work unit 3 for excavating earth and sand and the like. As shown in FIG. 2, the undercarriage 2 is configured to include a track frame 5, an idler wheel 9, a drive wheel 10, a crawler belt 12, a crawler belt tension adjusting device 16 and the like, which will be described later. Note that, hereinafter, the right side (the side of the idler wheel 9 described below) in FIG. 2 is referred to as one side (one side) or the front side in the frontward and rearward direction, and the left side (the side of the drive wheel 10 described later) in FIG. 2 is the frontward and rearward direction. Will be described as the other end side (other side) or the rear side.

  The track frame 5 serves as a base of the lower traveling body 2. The track frame 5 is provided with a center frame 6 on which the upper revolving structure 3 is mounted, and is provided on both left and right sides of the center frame 6, It is composed of left and right side frames 7 extending rearward.

  As shown in FIG. 3, FIG. 5, etc., the side frame 7 is formed as a rectangular tubular body extending in the front and rear directions by the upper plate 7A, the lower plate 7B, the inner plate 7C, the outer plate 7D, and the like. Further, the outer plate 7D of the side frame 7 is formed with a working opening 7E located nearer to one side for connecting a grease gun (not shown) to a greasing valve 27 described later (FIG. 2). reference). Further, a partition wall 15 described later is provided inside the side frame 7.

  The idler wheel bracket 8 is provided on one end side of the side frame 7. The idler wheel bracket 8 includes a flange plate 8A having a through hole 8A1 formed at the center thereof, which is joined to the end portion of the side frame 7 by welding or the like, and which penetrates in the front and rear directions, and a front side (one side) of the flange plate 8A. ), The inner wall plate 8B and the outer wall plate 8C are opposed to each other in the left and right directions, and the upper connecting plate 8D integrally connecting the upper parts of the wall plates 8B and 8C. The through hole 8A1 is inserted by the crawler belt tension adjusting device 16 when the crawler belt tension adjusting device 16 described later is assembled in the side frame 7.

  Further, as shown in FIG. 3, guide frames 8E and 8F extending in the front and rear directions are fixed to the inner surface of the inner wall plate 8B at predetermined intervals in the upper and lower directions. On the other hand, on the inner surface side of the outer wall plate 8C, guide frames 8G and 8H are fixedly attached to the guide frames 8E and 8F at predetermined intervals in the left and right directions and at predetermined intervals in the up and down directions. Has been done. Each of the guide frames 8E, 8F, 8G, 8H guides a yoke 17, which will be described later, slidably in the front and rear directions in a cross-shaped gap formed therebetween.

  The idler wheel 9 is located in the front and rear ends of the side frame 7 and provided in the idler wheel bracket 8. The idler wheel 9 is rotatably supported via a yoke 17 described later. A support shaft 9A extending in the left and right directions is provided in the center of the idler wheel 9, and both end sides of the support shaft 9A are rotatably attached to the left and right shaft insertion holes 19C of the yoke 17. As a result, the idler wheel 9 can rotate about the support shaft 9A and can move forward and backward along the guides 8E, 8F, 8G, 8H of the idler wheel bracket 8 via the yoke 17. .

  The drive wheel 10 is located at the other end of the side frame 7 in the front and rear directions, and is provided via a drive wheel bracket 11. The drive wheel 10 is composed of a sprocket or the like, and is rotated by a traveling hydraulic motor (not shown) to rotate a crawler belt 12 described later.

  The crawler belt 12 is wound around the idler wheel 9 and the drive wheel 10. As shown in FIG. 2, the crawler belt 12 is guided in the circumferential direction by the upper rollers 13 on the upper side of the side frame 7 and by the lower rollers 14 on the lower side of the side frame 7. The crawler belt 12 rotates around the drive wheel 10 to rotate around the drive wheel 10 and the idler wheel 9 to stably drive the hydraulic excavator 1 even on rough terrain.

  The partition wall 15 is provided in the side frame 7 while being separated from the idler wheel 9 toward the drive wheel 10 side. The partition wall 15 is located on the idler wheel 9 side of the side frame 7 and supports the other side of the buffer mechanism 20 of the crawler belt tension adjusting device 16 described later. The partition wall 15 is formed of a strength plate that closes the inside of the side frame 7 in the front and rear directions, and the periphery thereof is welded to the inner surface of the side frame 7. Further, a fitting hole 15A is formed in the partition wall 15 at the same height position as the center height position of the idler wheel 9. Into the fitting hole 15A, a protrusion 26C that constitutes a holder 26 of the buffer mechanism 20 described later is inserted.

  Next, the crawler belt tension adjusting device 16 that adjusts the tension of the crawler belt 12 will be described.

  The crawler belt tension adjusting device 16 is located inside the side frame 7 and is provided between the partition wall 15 and the idler wheel 9. The crawler belt tension adjusting device 16 adjusts the tension of the crawler belt 12 between the idler wheel 9 and the drive wheel 10. The crawler belt tension adjusting device 16 is arranged between the partition wall 15 provided in the side frame 7 and the idler wheel 9 in a state in which a spring force is generated. The crawler belt tension adjusting device 16 is configured to include a yoke 17 and a cushioning mechanism 20 described later.

  The yoke 17 is provided in the side frame 7 and the idler wheel bracket 8 so as to be movable in the front and rear directions. The yoke 17 rotatably supports the idler wheel 9. The yoke 17 has a U-shaped main body portion 18 having a tip end side (one end side) straddling the idler wheel 9, and left and right bearing portions 19 (which are attached to the tip end portion of the body portion 18). (Only the right side is shown).

  The body portion 18 of the yoke 17 has a stepped cylindrical spring receiving portion 18A on the base end side (the other end side), and the spring receiving portion 18A is axially attached to the tip of a yoke side rod 22 of a buffer mechanism 20 described later. It is fitted so that it can move. Further, the spring receiving portion 18A is provided with a one side spring cover plate 31 via a one side holding plate 30 described later. On the other hand, the tip end side of the main body portion 18 branches leftward and rightward to form an arm portion 18B, and a bearing portion 19 is bolted to each arm portion 18B.

  Each bearing portion 19 is provided with a base block 19A provided facing the side surface portions of the guide frames 8E to 8H of the idler wheel bracket 8 and a tip block 19B protruding outward from the base block 19A in the left and right directions. It consists of A shaft insertion hole 19C that rotatably supports the support shaft 9A of the idler wheel 9 is formed near the front side of the tip block 19B. The tip block 19B is arranged between the upper and lower guide frames 8E, 8F (8G, 8H).

  The cushioning mechanism 20 is located in the side frame 7 and attached to the yoke 17. The buffer mechanism 20 expands and contracts between the idler wheel 9 and the partition wall 15 when an excessive load acts. The buffer mechanism 20 is composed of a tension adjusting cylinder 21, a yoke side rod 22, a frame side rod 24, a spring member 25, a holder 26 and the like.

  The tension adjusting cylinder 21 is located in the side frame 7 and is provided between the partition wall 15 and the yoke 17. The tension adjusting cylinder 21 is formed in a stepped cylindrical shape extending in the front and rear directions. The tension adjusting cylinder 21 includes a spring receiving portion 21A having a through hole through which a frame-side rod 24, which will be described later, passes, and an extending tubular portion extending from the spring receiving portion 21A toward one end side (front side). 21B and is comprised.

  The other side spring cover plate 34 is provided in the spring receiving portion 21A via another side holding plate 33 described later. A spring member 25, which will be described later, is wound around the outer peripheral side of the extending tubular portion 21B. A yoke-side rod 22 and a frame-side rod 24, which will be described later, are slidably fitted on the inner peripheral side of the extending tubular portion 21B.

  The yoke side rod 22 is provided on one side of the tension adjusting cylinder 21 (on the side of the idle wheel 9). The yoke side rod 22 is inserted (fixed) at the base end side (the other end side) in the extension cylindrical portion 21B of the tension adjusting cylinder 21 in a press-fitted state. On the other hand, the tip end side (one end side) of the yoke side rod 22 is movably inserted into the spring receiving portion 18A of the yoke 17. A nut 23 is screwed onto the tip of the yoke-side rod 22 (see FIG. 4). The nut 23 holds the yoke side rod 22 in a state where it is prevented from coming off from the main body portion 18 of the yoke 17.

  The frame side rod 24 is provided on the other side of the tension adjusting cylinder 21 (on the side of the partition wall 15). The frame-side rod 24 is slidably inserted into the extension cylinder portion 21B of the tension adjusting cylinder 21 at the tip end side (one end side). A holder 26, which will be described later, is integrally attached to the base end side (the other end side) of the frame side rod 24 by using a means such as press fitting.

  The spring member 25 is provided between the spring receiving portion 21A of the tension adjusting cylinder 21 and the spring receiving portion 18A of the yoke 17. The spring member 25 is composed of a coil-shaped compression spring, one end side of which is supported by the spring receiving portion 18A via a one-side sandwiching plate 30 described below, and the other end side of which is a spring receiving portion via another-side sandwiching plate 33 described below. It is supported by 21A. The spring member 25 is compressed between the spring receiving portion 18A of the main body portion 18 forming the yoke 17 and the spring receiving portion 21A of the tension adjusting cylinder 21. As a result, the spring member 25 biases the yoke 17 in the direction away from the drive wheel 10.

  The holder 26 is integrally attached to the base end side (the other end side) of the frame side rod 24 by means of press fitting or the like. This holder 26 is formed in a rectangular shape and has an abutting plate portion 26A that abuts against the partition wall 15, and a press-fitting portion that projects from the abutting plate portion 26A toward one side (tension adjusting cylinder 21 side) and into which the frame-side rod 24 is press-fitted. It is configured by a portion 26B and a protrusion portion 26C that protrudes from the contact plate portion 26A toward the other side (the partition wall 15 side).

  A greasing valve 27 is provided in the press-fitting portion 26B at a position corresponding to the working opening 7E of the side frame 7. This greasing valve 27 is generally called a grease nipple, and is connected with a grease gun (not shown) when supplying grease into the extension cylinder portion 21B of the tension adjusting cylinder 21. Further, the greasing valve 27 can discharge the grease in the tension adjusting cylinder 21 when loosened.

  On the other hand, the protrusion 26C is fitted into the fitting hole 15A of the partition wall 15 with the contact plate portion 26A in contact with the partition wall 15. The outer periphery of the protrusion 26C is formed as a tapered surface 26C1 that reduces in diameter toward the other end. Accordingly, when the idler wheel 9 and the crawler belt tension adjusting device 16 are assembled to the side frame 7, even if the holder 26 side is tilted downward due to the weight of the crawler belt tension adjusting device 16, the tapered surface 26C1 causes the holder 26 to move. It can be guided to the fitting hole 15A of the partition wall 15.

  That is, as shown in FIG. 8, the guide frames 8E, 8F (8G) of the idler wheel bracket 8 are provided between the tip end block 19B of the bearing portion 19 and the upper and lower guide frames 8E, 8F (8G, 8H). , 8H) and a manufacturing tolerance of the height dimension L1 of the bearing portion 19 and a manufacturing tolerance of the height dimension L2 of the tip block 19B of the bearing portion 19 may cause a gap S in the upward and downward directions. If such a gap S occurs, when the idler wheel 9 and the crawler belt tension adjusting device 16 are assembled to the side frame 7, the other end side of the crawler belt tension adjusting device 16 ( The holder 26 side) is inclined downward (see FIG. 4). In this case, since the outer peripheral surface of the protrusion 26C of the holder 26 is formed as the tapered surface 26C1, the fitting hole 15A of the partition wall 15 and the holder 26 can be easily aligned.

  Next, the spring protection cover 28 provided in the crawler belt tension adjusting device 16 will be described.

  The spring protection covers 28 are located on one end side and the other end side of the crawler belt tension adjusting device 16 in the front and rear directions, and cover the spring member 25 from below. These spring protection covers 28 protect the spring member 25 from the flange plate 8A of the idler wheel bracket 8 and the lower roller 14 when the crawler belt tension adjusting device 16 is assembled to the side frame 7. Further, the spring protection cover 28 protects the spring member 25 from flying stones and the like that are jumped up during traveling after the crawler belt tension adjusting device 16 is assembled. The spring protection cover 28 includes one side spring protection cover 29 arranged at one end side in the front and rear directions of the spring member 25 and another side spring arranged at the other end side in the front and rear directions of the spring member 25. It is composed of a protective cover 32.

  The one-side spring protection cover 29 is provided between the spring receiving portion 18A of the main body portion 18 forming the yoke 17 and the spring member 25. The one-side spring protection cover 29 covers the lower side of the spring member 25 at the high stress portion on the yoke 17 side (for example, one to three turns from the yoke 17 side) when the spring member 25 expands and contracts. That is, the one-side spring protection cover 29 protects the portion of the spring member 25 on the side of the yoke 17 that receives a large load as the spring member 25 expands and contracts. The one-side spring protection cover 29 is composed of the one-side holding plate 30 and the one-side spring cover plate 31.

  The one-side clamping plate 30 is clamped between the front and rear ends of the spring member 25 and the spring receiving portion 18A of the yoke 17. The one-side holding plate 30 is formed, for example, in an annular shape, and the yoke-side rod 22 penetrates the inner peripheral side in the front and rear directions. The radial dimension (diameter) of the one-side holding plate 30 is larger than the radial dimension of the spring member 25.

  The one-side spring cover plate 31 is fixed to the one-side holding plate 30 by welding or the like, and extends from the one-side holding plate 30 toward the rear side (the other side). The one side spring cover plate 31 covers the lower side of the spring member 25 while curving in an arc shape along the outer peripheral surface of the spring member 25. That is, the one-side spring cover plate 31 covers the lower side of the spring member 25 while being cantilevered by the one-side holding plate 30.

  Here, the radial dimension of the one-side holding plate 30 is larger than the radial dimension of the spring member 25. Therefore, the one-side spring cover plate 31 covers the lower side of the spring member 25 in a non-contact state with the spring member 25. Further, the one-side spring cover plate 31 covers, for example, the lower side of the spring member 25 for one to three turns (for example, 1.5 turns) from the one-side holding plate 30.

  Therefore, the one-side spring cover plate 31 protects the end of the spring member 25 on the side of the yoke 17 that receives a large load. As a result, when the crawler belt tension adjusting device 16 is assembled to the side frame 7, the one-side spring cover plate 31 causes the spring member 25 to contact the flange plate 8A of the idler wheel bracket 8 (the lower edge portion of the through hole 8A1). It is possible to suppress the contact with the lower roller 14 or the lower roller 14. Further, after the crawler belt tension adjusting device 16 is assembled, it is possible to prevent flying stones from traveling (contacting) with the yoke-side end of the spring member 25 during traveling.

  The other side spring protection cover 32 is provided between the spring receiving portion 21A of the tension adjusting cylinder 21 and the spring member 25. The other side spring protection cover 32 covers the lower side of the spring member 25 at the high stress portion on the tension adjusting cylinder 21 side (for example, 1 to 3 turns from the tension adjusting cylinder 21 side) when the spring member 25 expands and contracts. Is. That is, the other side spring protection cover 32 protects a portion of the spring member 25 on the side of the tension adjusting cylinder 21 which receives a large load as the spring member 25 expands and contracts. The other-side spring protection cover 32 is composed of the other-side holding plate 33 and the other-side spring cover plate 34.

  The other side holding plate 33 is held between the other front and rear ends of the spring member 25 and the spring receiving portion 21A of the tension adjusting cylinder 21. The other side holding plate 33 is formed, for example, in an annular shape, and the extension cylinder portion 21B of the tension adjusting cylinder 21 penetrates the inner peripheral side in the front and rear directions. The radial dimension (diameter) of the other side holding plate 33 is larger than the radial dimension of the spring member 25.

  The other side spring cover plate 34 is fixed to the other side holding plate 33 by welding or the like, and extends from the other side holding plate 33 toward the front side (one side). The other-side spring cover plate 34 covers the lower side of the spring member 25 while curving in an arc shape along the outer peripheral surface of the spring member 25. That is, the other side spring cover plate 34 covers the lower side of the spring member 25 while being cantilevered by the other side holding plate 33.

  Here, the radial dimension of the other side holding plate 33 is formed to be larger than the radial dimension of the spring member 25. Therefore, the other side spring cover plate 34 covers the lower side of the spring member 25 in a non-contact state with the spring member 25. The other-side spring cover plate 34 covers, for example, the lower side of the spring member 25 for two turns from the other-side holding plate 33.

  Therefore, the other side spring cover plate 34 protects the end of the spring member 25 on the side of the tension adjusting cylinder 21 that receives a large load. As a result, when the crawler belt tension adjusting device 16 is assembled to the side frame 7, the spring member 25 of the other side spring cover plate 34 contacts the flange plate 8A of the idler wheel bracket 8 (the lower edge portion of the through hole 8A). It is possible to suppress the contact with the lower roller 14 or the lower roller 14. Further, after the crawler belt tension adjusting device 16 is assembled, it is possible to suppress the stepping stones during traveling from contacting (colliding) with the end of the spring member 25 on the tension adjusting cylinder 21 side.

  The hydraulic excavator 1 equipped with the track-mounted vehicle according to the first embodiment has the above-described configuration. Next, the operation of attaching the crawler belt tension adjusting device 16 to the side frame 7 will be described.

  First, the idler wheel 9 and the crawler belt tension adjusting device 16 are assembled, lifted by a crane and moved to the track frame 5 side. Then, the other end of the buffer mechanism 20 is inserted into the idle wheel bracket 8 and the side frame 7, and the bearing portions 19 of the yoke 17 are inserted between the guide frames 8E to 8H of the idle wheel bracket 8. In this case, as shown in FIG. 8, between the tip block 19B of each bearing portion 19 and the upper and lower guide frames 8E, 8F (8G, 8H), an upward and downward gap S is produced due to manufacturing tolerances. Occurs.

  By the way, in the above-mentioned conventional technique, when the other end side of the buffer mechanism tilts downward due to its own weight due to the gap S, the spring member comes into contact (interference) with the spring support plate provided in the side frame, and the life of the spring member is shortened. It may decrease. Further, if the spring support plate is not provided in the side frame, the spring member may contact (interfere with) the idler wheel bracket or the lower roller, which may shorten the life of the spring member.

  Therefore, in the present embodiment, the crawler belt tension adjusting device 16 is provided with a spring protection cover 28 that covers the spring member 25 from below. The spring protection cover 28 includes one side spring protection cover 29 arranged at one end side in the front and rear direction of the spring member 25 and another side spring protection cover arranged at the other end side in the front and rear direction of the spring member 25. 32 and 32.

  As shown in FIG. 4, when the other end side (the holder 26 side) of the cushioning mechanism 20 is tilted downward by its own weight, for example, the one side spring cover plate 31 and the other which cover the spring member 25 from the lower side. The side spring cover plate 34 contacts the lower roller 14. Accordingly, the spring member 25 can be inserted into the side frame 7 without contacting other members such as the lower roller 14.

  Further, when the hydraulic excavator 1 is running, there is a risk that, for example, the crawler belt 12 will be repelled by soil or the like toward the spring member 25. In such a case, since the one side spring cover plate 31 and the other side spring cover plate 34 protect the spring member 25, flying stones collide with the one side spring cover plate 31 and the other side spring cover plate 34. . Therefore, the life of the spring member 25 can be extended, and the running stability and reliability of the track-type vehicle (hydraulic excavator 1) can be improved.

  Next, FIG. 9 to FIG. 11 show a second embodiment of the present invention. A feature of this embodiment is that the one side spring protection cover 45 and the other side spring protection cover 49 are detachably provided from the crawler belt tension adjusting device 16. In the second embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

  Similar to the yoke 17 according to the first embodiment, the yoke 41 is configured to include a main body portion 42 and left and right bearing portions 43 (only the right side is shown). The body portion 42 of the yoke 41 serves as a stepped cylindrical spring receiving portion 42A on the base end side (the other end side), and the spring receiving portion 42A is axially attached to the tip of the yoke side rod 22 of the buffer mechanism 20. It is fitted so that it can move. Further, the tip end side (one end side) of the main body portion 42 branches leftward and rightward to form an arm portion 42B, and a bearing portion 43 is bolted to each arm portion 42B. On the lower end side of the spring receiving portion 42A, a plurality of female screw holes (not shown) are formed in the front and rear directions at intervals in the circumferential direction of the spring receiving portion 42A. A bolt 47 for attaching a one-side spring protection cover 45 described later is screwed into these female screw holes.

  The tension adjusting cylinder 44, similarly to the tension adjusting cylinder 21 according to the first embodiment, includes a spring receiving portion 44A and an extending cylinder portion 44B. On the lower end side of the spring receiving portion 44A of the tension adjusting cylinder 44, a plurality of female screw holes (not shown) are formed in the front and rear directions at intervals in the circumferential direction of the spring receiving portion 44A. . Bolts 51 for attaching the other side spring protection cover 49 described later are screwed into these female screw holes.

  The one-side spring protection cover 45 is provided between the spring receiving portion 42 </ b> A of the main body portion 42 that constitutes the yoke 41 and the spring member 25. The one-side spring protection cover 45 covers the lower side of the spring member 25 in the high stress portion on the yoke 41 side (for example, 1 to 3 turns from the yoke 41 side) when the spring member 25 expands and contracts. That is, the one-side spring protection cover 45 protects the portion of the spring member 25 on the side of the yoke 41 that receives a large load as the spring member 25 expands and contracts. The one-side spring protection cover 45 includes a one-side mounting plate 46 and a one-side spring cover plate 48.

  The one-side mounting plate 46 is detachably attached to the spring receiving portion 42A of the yoke 41. As shown in FIG. 10, the one-side mounting plate 46 is curved in an arc shape along the spring receiving portion 42A of the yoke 41. The one-side spring protection cover 45 is mounted on the spring receiving portion 42A of the yoke 41 with the one-side mounting plate 46 in contact with the spring receiving portion 42A. It is detachably attached to the portion 42A. The bolt 47 constitutes the fastener of the present invention.

  The one-side spring cover plate 48 is fixed to the radially outer end of the one-side mounting plate 46 by welding or the like. The one-side spring cover plate 48 extends from the one-side mounting plate 46 toward the rear side (the other side), covers the lower side of the spring member 25 while curving in an arc shape along the outer peripheral surface of the spring member 25. There is. That is, the one-side spring cover plate 48 extends from the one-side mounting plate 46 toward the rear side while being cantilevered by the one-side mounting plate 46. Specifically, the one-side spring cover plate 48 extends, for example, from the spring receiving portion 42A of the yoke 41 to a position below the spring member 25 for one to three turns, and is below the spring member 25 in a non-contact state with the spring member 25. Covers. As a result, the one-side spring cover plate 48 protects the end of the spring member 25 on the side of the yoke 41 that receives a large load.

  The other side spring protection cover 49 is provided between the spring receiving portion 44A of the tension adjusting cylinder 44 and the spring member 25. The other-side spring protection cover 49 covers the lower side of the spring member 25 at the high stress portion (for example, 1 to 3 turns from the tension adjusting cylinder 44 side) on the tension adjusting cylinder 44 side when the spring member 25 expands and contracts. Is. That is, the other side spring protection cover 49 protects the portion of the spring member 25 on the side of the tension adjusting cylinder 44 that receives a large load as the spring member 25 expands and contracts. The other-side spring protection cover 49 is composed of the other-side mounting plate 50 and the other-side spring cover plate 52.

  The other side attachment plate 50 is detachably attached to the spring receiving portion 44A of the tension adjusting cylinder 44. As shown in FIG. 11, the other side mounting plate 50 is curved in an arc shape along the spring receiving portion 44A of the tension adjusting cylinder 44. Then, the other side spring protection cover 49 is screwed into the female screw hole of the spring receiving portion 44A while the other side mounting plate 50 is in contact with the spring receiving portion 44A of the tension adjusting cylinder 44. It is detachably attached to the spring receiving portion 44A. The bolt 51 constitutes the fastener of the present invention.

  The other side spring cover plate 52 is fixed to the radially outer end of the other side mounting plate 50 by welding or the like. The other-side spring cover plate 52 extends from the other-side mounting plate 50 toward the front side, covers the lower side of the spring member 25 while curving in an arc shape along the outer peripheral surface of the spring member 25. That is, the other side spring cover plate 52 extends from the other side mounting plate 50 toward the front side while being cantilevered by the other side mounting plate 50. Specifically, the other-side spring cover plate 52 extends, for example, from the spring receiving portion 44A of the tension adjusting cylinder 44 to a position below the spring member 25 for one to three turns and is in non-contact with the spring member 25. It covers the lower side. As a result, the other side spring cover plate 52 protects the end portion of the spring member 25 on the tension adjusting cylinder 44 side that receives a large load.

  Thus, also in the second embodiment configured in this way, the one-side spring protection cover 45 and the other-side spring protection cover 49 are the same as the first embodiment described above, and the crawler belt tension adjusting device 16 does not. It is possible to prevent the spring member 25 from coming into contact with the flange plate 8A of the idler wheel bracket 8 (the lower edge portion of the through hole 8A) or the lower roller 14 when the is assembled to the side frame 7. it can. Further, the one-side spring protection cover 45 and the other-side spring protection cover 49 can suppress contact (collision) of flying stones and the like with the spring member 25 during traveling after the crawler belt tension adjusting device 16 is assembled.

  In particular, in the second embodiment, the one-side spring protection cover 45 is detachably attached to the yoke 41 by the bolt 47, and the other-side spring protection cover 49 is detachably attached to the tension adjusting cylinder 44 by the bolt 51. ing. Therefore, if the one-side spring cover plate 48 and the other-side spring cover plate 52 are deformed, the one-side spring protection cover 45 and the other-side spring protection cover 49 can be easily replaced.

  In the above-described first embodiment, the case where the one side spring cover plate 31 and the other side spring cover plate 34 cover the lower sides of both ends of the spring member 25 of the spring member 25 that receives a large load is described. I explained using an example. However, the present invention is not limited to this, and for example, as in the modified example shown in FIG. 12, the one side spring cover plate 61 and the other side spring cover plate 62 are formed to be long in the front and rear directions and the spring member 25. You may cover the lower side of. This also applies to the second embodiment.

  Further, in the above-described first embodiment, the case where the one side spring protection cover 29 and the other side spring protection cover 32 are provided on both ends of the spring member 25 has been described as an example. However, the present invention is not limited to this, and for example, the spring protection cover may be provided only on one end of the spring member 25. This also applies to the second embodiment.

  Furthermore, in each of the embodiments, the hydraulic excavator 1 is described as an example of the tracked vehicle. However, the present invention is not limited to this, and can be widely applied to other tracked vehicles such as hydraulic cranes and bulldozers.

1 Hydraulic excavator (tracked vehicle)
5 track frame 7 side frame 9 idler wheel 10 drive wheel 12 crawler track 15 bulkhead 16 crawler belt tension adjusting device 17,41 yoke 18A, 42A spring receiving part 21,44 tension adjusting cylinder 21A, 44A spring receiving part 25 spring member 28 spring protection cover 29,45 One side spring protection cover 30 One side holding plate 31,48,61 One side spring cover plate 32,49 Other side spring protection cover 33 Other side holding plate 34,52,62 Other side spring cover plate 46 One side mounting Plate 47,51 bolt (fastener)
50 Other side mounting plate

Claims (2)

A side frame that constitutes a track frame and extends in the front and rear directions, an idle wheel provided on one end side in the front and rear directions of the side frame, and a side wheel provided on the other end side in the front and rear directions of the side frame. A drive wheel, a crawler belt wound around the idler wheel and the drive wheel, a partition wall provided in the side frame spaced from the idler wheel to the drive wheel side, the partition wall and the idle wheel A crawler belt tension adjusting device provided between the wheel and the crawler belt for adjusting the tension of the crawler belt,
The crawler belt tension adjusting device is provided in the side frame so as to be movable in the front and rear directions, and has a yoke to which the idler wheel is attached, a tension adjusting cylinder provided between the partition wall and the yoke, and In a tracked vehicle including a spring member provided between a spring receiving portion of a tension adjusting cylinder and a spring receiving portion of the yoke, the spring member biasing the yoke in a direction away from the drive wheel,
The crawler belt tension adjusting device is provided with a spring protection cover that covers the spring member from below ,
The spring protection cover includes a one-side spring protection cover arranged on one end side in the front and rear directions of the spring member, and another spring protection cover arranged on the other end side in the front and rear directions of the spring member. Consists of
The one-side spring protection cover includes a one-side holding plate sandwiched between one of front and rear ends of the spring member and a spring receiving portion of the yoke, and one side holding plate fixed to the one-side holding plate. And a one-side spring cover plate that covers the lower side of the spring member while curving in an arc shape along the outer peripheral surface,
The other-side spring protection cover is fixed to the other-side holding plate and the other-side holding plate sandwiched between the other front and rear ends of the spring member and the spring receiving portion of the tension adjusting cylinder. A track-mounted vehicle comprising a spring cover plate that is curved along an outer peripheral surface of the spring member and covers the underside of the spring member . A side frame that constitutes a track frame and extends in the front and rear directions, an idle wheel provided on one end side in the front and rear directions of the side frame, and a side wheel provided on the other end side in the front and rear directions of the side frame. A drive wheel, a crawler belt wound around the idler wheel and the drive wheel, a partition wall provided in the side frame spaced from the idler wheel to the drive wheel side, the partition wall and the idle wheel A crawler belt tension adjusting device provided between the wheel and the crawler belt for adjusting the tension of the crawler belt,
The crawler belt tension adjusting device is provided in the side frame so as to be movable in the front and rear directions, and has a yoke to which the idler wheel is attached, a tension adjusting cylinder provided between the partition wall and the yoke, and In a tracked vehicle including a spring member provided between a spring receiving portion of a tension adjusting cylinder and a spring receiving portion of the yoke, the spring member biasing the yoke in a direction away from the drive wheel,
The crawler belt tension adjusting device is provided with a spring protection cover that covers the spring member from below,
The spring protection cover includes a one-side spring protection cover arranged on one end side in the front and rear directions of the spring member, and another spring protection cover arranged on the other end side in the front and rear directions of the spring member. It is constituted by,
The one-side spring protection cover includes a one-side mounting plate detachably attached to a spring receiving portion of the yoke by using a fastener, and a circle fixed along the one-side mounting plate along an outer peripheral surface of the spring member. And a one-side spring cover plate that covers the lower side of the spring member while curving in an arc shape,
The other side spring protection cover is attached to the spring receiving portion of the tension adjusting cylinder detachably using a fastener, and the other side mounting plate is fixed to the other side mounting plate along the outer peripheral surface of the spring member. other side crawler type vehicle you characterized in that it is constituted by a spring cover plate for covering the lower side of the curved while the spring member in an arc Te.

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