JP6640770B2 - Tracked vehicles - Google Patents

Description

  The present invention relates to a tracked vehicle having a track such as a hydraulic shovel and a hydraulic crane, and more particularly to a tracked vehicle having a track tension adjusting device for adjusting the tension of the track.

  A hydraulic excavator as a representative example of a tracked vehicle is a crawler (crawler) type lower traveling body capable of self-propelling, an upper revolving body rotatably mounted on the lower traveling body, and an elevating motion on the upper revolving body. And a front device provided as possible.

  In this case, the lower traveling body of the excavator is provided with a track frame having left and right side frames extending in the front and rear directions, and at one end of the side frame via a yoke so as to be movable in the front and rear directions. Idler wheel, a drive wheel provided on the other end side of the side frame, a crawler belt wound and provided between the idler wheel and the drive wheel, and a side frame separated from the idler wheel toward the drive wheel side. A crawler belt tension adjusting device is provided between the partition wall and the idler wheel and adjusts the crawler belt tension.

  The crawler belt tension adjusting device includes a yoke provided at one end of the side frame so as to be movable forward and rearward and having an idler wheel attached thereto, a tension adjusting cylinder provided between the partition wall and the yoke, and a tension adjusting cylinder. A spring member is provided between the spring receiving portion and the spring receiving portion of the yoke and urges the yoke away from the drive wheels.

  The tension adjusting cylinder includes a tube provided in the side frame, a yoke-side rod having one end inserted into the yoke so as to be relatively movable and the other end inserted into the tube, and one end inserted into the tube at the other end. A grease chamber formed in the tube by the frame-side rod, the yoke-side rod and the frame-side rod, the end of which is provided in the frame-side rod in the axial direction and one end communicates with the grease chamber and the other end And an axial grease passage opened to the outside of the frame side rod. A greasing valve is attached to the other end of the axial grease passage, and grease is supplied to the grease chamber through the greasing valve.

  Therefore, the crawler belt tension adjusting device can adjust the tension of the crawler belt according to the amount of grease filled in the grease chamber. For example, when increasing the tension of the crawler belt, the amount of grease filled in the grease chamber is increased, and the frame-side rod is extended from the tube. Accordingly, the distance between the idler wheel and the drive wheel is increased by an amount corresponding to the extension of the frame-side rod, and the tension of the crawler belt can be increased. On the other hand, when the tension of the crawler belt is weakened, the filling amount of the grease into the grease chamber is reduced, and the rod on the frame side is reduced in the tube. As a result, the distance between the idler wheel and the drive wheel is reduced by the reduced size of the frame-side rod, and the tension of the crawler belt can be reduced.

  By the way, when the hydraulic shovel climbs on a rock or the like when traveling on uneven terrain, an external force acts on the idler wheel, and the external force is transmitted to the tension adjusting cylinder via the yoke. In this case, the external force acting on the idler wheel is often an upward or downward external force due to the lifting of the hydraulic shovel from the ground during traveling. On the other hand, since the yoke-side rod of the tension adjusting cylinder is pressed into the tube and fixed, the external force to the idler wheel mainly acts on one end of the frame-side rod slidably inserted into the tube. . As a result, a phenomenon (one contact) occurs in which one end of the frame-side rod comes into contact with the inner peripheral surface of the tube, and fretting wear occurs on the outer peripheral surface of one end of the frame-side rod. Will decrease.

  On the other hand, there has been proposed a crawler belt tension adjusting device provided with a greasing passage extending in the axial direction separately from a grease passage for injecting grease into a grease chamber with respect to a frame-side rod. According to this crawler belt tension adjusting device, by supplying lubricating grease between the outer peripheral surface of the frame-side rod and the inner peripheral surface of the tube through the greasing path, wear of the outer peripheral surface of the frame-side rod is suppressed. (See Patent Document 1).

JP 2015-155274 A

  However, the crawler belt tension adjusting device according to the prior art separates lubricating grease between the outer peripheral surface of the frame-side rod and the inner peripheral surface of the tube through a greasing passage, separately from an operation of supplying grease to the grease chamber through a grease passage. There is a problem that the work of supplying lubricating grease must be performed, and the work of supplying the lubricating grease is complicated. Further, in the crawler belt tension adjusting device according to the prior art, since two passages, that is, a grease passage and a greasing passage extending in the axial direction are formed in the frame-side rod, a greasing plug is individually provided in each passage. As a result, there is a problem that the configuration of the frame-side rod is complicated.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and provides a tracked vehicle capable of suppressing wear of a frame-side rod constituting a tension adjustment cylinder and increasing the durability of a crawler belt tension adjustment device. It is intended to provide.

  In order to solve the above-described problems, the present invention provides a track frame, a side frame extending forward and rearward, an idler wheel provided at one end of the side frame, and an idle wheel provided at the other end of the side frame. Drive wheel, crawler belt provided to be wound around the idler wheel and the drive wheel, a partition provided in the side frame separated from the idler wheel to the drive wheel side, the partition, A crawler belt tension adjusting device provided between the idler wheel and the crawler belt to adjust the tension of the crawler belt, wherein the crawler belt tension adjusting device is provided at one end of the side frame so as to be movable in a forward and rearward direction; A yoke to which a wheel is attached, a tension adjusting cylinder provided between the partition wall and the yoke, and the yoke provided between a spring receiving portion of the tension adjusting cylinder and a spring receiving portion of the yoke. The tension adjusting cylinder is constituted by a tube provided in the side frame, and one end is inserted into the yoke so as to be relatively movable and the other end is inserted in the tube. The yoke-side rod inserted, the frame-side rod having one end inserted into the tube and the other end contacting the partition wall, and the yoke-side rod and the frame-side rod are formed in the tube. A tracked vehicle comprising a grease chamber and an axial grease passage provided in the frame-side rod so as to extend in the axial direction and having one end communicating with the grease chamber and the other end opened to the outside of the frame-side rod. Applied.

The feature of the present invention, on the frame side rod at one end of the frame side rod, provided through downward, both ends the frame side rod with site halfway communicating with said axial grease passage A radial vertical grease passage opening on the outer peripheral surface of the frame rod; and a frame-side rod provided at one end side of the frame-side rod so as to penetrate the frame rod in the left and right directions. A radial horizontal grease passage that opens to the outer peripheral surface of the frame-side rod, and a portion of the outer peripheral surface of the frame-side rod where both ends of the radial vertical grease passage and the radial horizontal grease passage open at the entire circumference. over provided, seen including an annular groove for holding the grease between the inner peripheral surface of said tube, said radially Tategu from the end surface of the one end side of the frame side rod Over scan path and the axial dimension of up to hole the center of the radial side grease passage is in is 10% or less of the total axial length of the frame side rod.

  According to this configuration, in order to adjust the tension of the crawler belt, when the grease is filled in the grease chamber through the axial grease passage, a part of the grease is released through the radial grease passage communicating with the axial grease passage. Is supplied to an annular groove formed on the outer peripheral surface of the tube, and is held between the annular groove and the inner peripheral surface of the tube. Therefore, the sliding surface between the outer peripheral surface of the frame-side rod and the inner peripheral surface of the tube can be lubricated with grease, and the wear of the frame-side rod can be suppressed. Can be. In addition, since the grease can be supplied to the sliding surface between the outer peripheral surface of the frame side rod and the inner peripheral surface of the tube at the same time as the operation of filling the grease into the grease chamber, the workability can be improved.

1 is a front view showing a hydraulic excavator as a tracked vehicle according to an embodiment of the present invention. It is a front view which expands and shows the lower traveling body in FIG. FIG. 3 is a cross-sectional view showing the inside of a front portion of the side frame in FIG. 2. FIG. 4 is a cross-sectional view of the crawler belt tension adjusting device as viewed from a direction indicated by arrows IV-IV in FIG. 3. It is a perspective view which shows a frame side rod, an axial grease passage, a radial grease passage, etc. in a partial cross section. It is a principal part enlarged view which shows the axial grease passage provided in the one end side of the frame side rod, the radial longitudinal grease passage, the radial lateral grease passage, and an annular groove. FIG. 7 is a longitudinal sectional view of the axial grease passage, the radial longitudinal grease passage, the radial lateral grease passage, and the annular groove of the frame-side rod as viewed from the direction of arrows VII-VII in FIG. FIG. 7 is a cross-sectional view of the axial grease passage, the radial longitudinal grease passage, the radial lateral grease passage, and the annular groove of the frame-side rod as viewed from the direction of arrows VIII-VIII in FIG. 6. FIG. 9 is an enlarged cross-sectional view showing a radial horizontal grease passage, an annular groove, a rod-side tapered surface, and a groove-side tapered surface in FIG. 8 in an enlarged manner. It is a perspective view similar to FIG. 5 which shows the modification of a frame side rod.

  Hereinafter, an embodiment of a tracked vehicle according to the present invention will be described in detail with reference to the accompanying drawings, taking an example in which the embodiment is applied to a hydraulic shovel.

  In FIG. 1, a hydraulic excavator 1 which is a typical example of a tracked vehicle includes a self-propelled crawler (crawler) type lower traveling body 2 and an upper revolving body 3 rotatably mounted on the lower traveling body 2. And a front device 4 provided on the front side of the upper revolving unit 3 so as to be able to move up and down. The front device 4 is used for excavating earth and sand. As shown in FIG. 2, the lower traveling body 2 includes a track frame 5, idler wheels 10, drive wheels 11, a crawler belt 13, and a crawler belt tension adjusting device 16, which will be described later.

  The track frame 5 forms a base of the lower traveling body 2. The track frame 5 is provided on both the left and right sides of the center frame 6 on which the upper swing body 3 is rotatably mounted, and the left and right sides of the center frame 6 are extended forward and backward (only the right side is shown). And the side frame 7.

  As shown in FIG. 3, the side frame 7 is formed as a rectangular cylinder surrounded by an upper plate 7A, a lower plate 7B, an inner plate 7C, and an outer plate 7D, and extends forward and backward. A work opening 7E is formed in the outer plate 7D of the side frame 7 at a front side in the front and rear directions (hereinafter, referred to as a front side). The working opening 7E is an opening for performing a work of connecting a greasing tool (not shown) such as a grease gun to a greasing valve 28 described later.

  The partition 8 is provided in the side frame 7 so as to be separated from the idler wheel 10 toward the drive wheel 11. The partition 8 is made of a thick plate, and is fixed to the inner surface of the side frame 7 by means such as welding. The partition wall 8 defines a space for accommodating the crawler belt tension adjusting device 16 in the side frame 7. Further, a holder mounting hole 8A is provided at the center of the partition wall 8, and a holder 23 described later is fitted into the holder mounting hole 8A.

  The idler wheel bracket 9 is provided on the front side of the side frame 7. The idler wheel bracket 9 includes a flange plate 9A joined to the end of the side frame 7 by welding or the like, an inner support plate 9B and an outer support plate 9C protruding forward from the flange plate 9A and facing left and right. An upper connecting plate 9D is formed by integrally connecting the upper portions of the supporting plates 9B and 9C. The flange plate 9A is formed with a through hole 9E penetrating in the front and rear directions, and a yoke 17 described later is loosely inserted into the through hole 9E. On the inner surface side of the inner support plate 9B and the outer support plate 9C, an upper guide 9F and a lower guide 9G opposing in the upper and lower directions are provided extending in the front and rear directions, respectively. The upper guide 9F and the lower guide 9G guide the yoke 17 slidably forward and backward.

  The idler wheel 10 is provided at one end side (front end side) in the front and rear directions of the side frame 7, and is rotatably supported by the idler wheel bracket 9. A support shaft 10A extending leftward and rightward is provided at the center of the idler wheel 10, and both ends of the support shaft 10A are rotatably supported by a left bearing arm 10B and a right bearing arm 10C. The left bearing arm 10B and the right bearing arm 10C are respectively attached to the front ends of the left arm 17B and the right arm 17C of the yoke 17 using bolts. As a result, the idler wheel 10 is integrated with the yoke 17 and can move forward and backward along the upper guide 9F and the lower guide 9G of the idler bracket 9.

  The drive wheels 11 are rotatably provided via drive wheel brackets 12 on the rear end sides in the front and rear directions of the side frames 7. The drive wheel 11 is configured by a sprocket, and is driven to rotate by a traveling hydraulic motor (not shown), thereby driving a crawler belt 13 to be described later to orbit.

  The crawler belt 13 is provided to be wound around the idler wheel 10 and the drive wheel 11. The crawler belt 13 is guided by an upper roller 14 above the side frame 7 and is guided by a lower roller 15 below the side frame 7. The crawler belt 13 is driven to rotate by the drive wheels 11, and allows the hydraulic excavator 1 to run stably even on uneven terrain.

  The crawler belt tension adjusting device 16 is provided between the partition wall 8 and the idler wheel 10, and adjusts the tension of the crawler belt 13 wound around the idler wheel 10 and the drive wheel 11. Here, the crawler belt tension adjusting device 16 includes a yoke 17, a tension adjusting cylinder 18, a spring member 24, and the like.

  The yoke 17 is provided on the idler wheel bracket 9 arranged on one end side of the side frame 7 so as to be movable forward and backward. The yoke 17 supports the idler wheel 10 along the upper guide 9F and the lower guide 9G of the idler wheel bracket 9 so as to be movable forward and backward. Here, as shown in FIG. 4, the yoke 17 is formed by an annular spring receiving portion 17A that receives one end of the spring member 24, and a left arm 17B and a right arm 17C that bifurcate from the spring receiving portion 17A. The yoke 17 is formed in a V shape as a whole. The inner peripheral side of the spring receiving portion 17A is a rod insertion hole 17D through which a yoke-side rod 20 described later is slidably inserted. The left bearing arm 10B of the idle wheel 10 is attached to the front end of the left arm 17B, and the right bearing arm 10C of the idle wheel 10 is attached to the front end of the right arm 17C.

  The tension adjusting cylinder 18 is provided between the partition 8 and the yoke 17 in the side frame 7. As shown in FIG. 4, the tension adjusting cylinder 18 includes a tube 19, a yoke-side rod 20, a frame-side rod 22, a grease chamber 25, an axial grease passage 26, and a radial longitudinal grease passage 29, which will be described later. , A radial horizontal grease passage 30 and an annular groove 31. The tension adjusting cylinder 18 expands and contracts the frame-side rod 22 with respect to the tube 19 in accordance with the amount of grease filled in the grease chamber 25, and moves the yoke 17 forward and backward, so that the idle wheel The initial tension of the crawler belt 13 wound between the driving wheel 11 and the driving wheel 11 is adjusted.

  The tube 19 is provided in the side frame 7 so as to extend forward and backward. The tube 19 is formed in a stepped cylindrical shape as a whole. The inner peripheral side of the tube 19 is a rod sliding hole 19A, and the outer peripheral side of the tube 19 is integrally formed with a flange-shaped spring receiving portion 19B located on the partition 8 side. Further, a rod mounting hole 19C having a smaller diameter than the rod sliding hole 19A is formed at the end of the tube 19 on the yoke 17 side.

  The yoke-side rod 20 is provided between the tube 19 and the yoke 17. One end of the yoke-side rod 20 in the front and rear directions (the yoke 17 side) is slidably inserted into a rod insertion hole 17D formed in a spring receiving portion 17A of the yoke 17. The other end in the front and rear directions (the tube 19 side) of the yoke-side rod 20 is fixed to the rod mounting hole 19C of the tube 19 by using a press-fitting means. A rod male screw 20A is provided on the outer peripheral surface on one end side of the yoke-side rod 20, and a nut 21 is screwed to the rod male screw 20A. Thus, the spring receiving portion 17A of the yoke 17 is prevented from being pulled out in the axial direction by the nut 21 screwed into the male rod screw 20A. Further, the nut 21 is loosened by a locking member 21A provided on an end surface on one end side of the yoke-side rod 20. As described above, one end of the yoke-side rod 20 is relatively movably inserted into the rod insertion hole 17D of the yoke 17, and the yoke-side rod 20 and the yoke 17 are integrated.

  The frame side rod 22 is provided between the tube 19 and the partition wall 8. As shown in FIGS. 4 and 5, the frame-side rod 22 is formed of a columnar body extending in the front and rear directions, and the other end of the frame-side rod 22 in the front and rear directions (the partition 8 side) is provided with a holder described later. Reference numeral 23 is integrally fixed by means such as press fitting. One end (the tube 19 side) in the front and rear directions of the frame side rod 22 is slidably inserted into a rod sliding hole 19A of the tube 19, and the outer peripheral surface 22A of the frame side rod 22 is It is in sliding contact with the inner peripheral surface 19D of the rod sliding hole 19A. The frame-side rod 22 has an axial grease passage 26, a valve mounting hole 27, a radial vertical grease passage 29, a radial horizontal grease passage 30, and an annular groove 31, which will be described later.

  The holder 23 forms a part of the frame-side rod 22 by being integrally fixed to the other end of the frame-side rod 22. The holder 23 has a rectangular plate shape, a contact plate 23A that contacts the partition wall 8, a hollow tapered mounting protrusion 23B protruding from a surface of the contact plate 23A that contacts the partition wall 8, and a contact plate 23A. It has a bottomed cylindrical rod insertion tube 23C protruding from the surface of the contact plate 23A opposite to the partition wall 8. The other end of the frame-side rod 22 protruding from the tube 19 is press-fitted (fixed) into the rod insertion tube 23C of the holder 23, and the mounting protrusion 23B of the holder 23 is inserted into the holder mounting hole 8A of the partition wall 8. Mated. Thus, the holder 23 is positioned with respect to the side frame 7 in a state where the mounting protrusion 23B is supported by the partition wall 8.

  The spring member 24 is provided between a spring receiving portion 19B of the tube 19 constituting the tension adjusting cylinder 18 and a spring receiving portion 17A of the yoke 17. The spring member 24 is formed of a compression spring, and is mounted between the spring receiving portion 19B of the tube 19 and the spring receiving portion 17A of the yoke 17 in a compressed state. The spring member 24 presses the yoke 17 together with the idler wheel 10 in a direction away from the drive wheel 11.

  That is, the crawler belt tension adjusting device 16 constantly presses the idler wheel 10 in a direction away from the drive wheel 11 by the spring force of the spring member 24 to give the crawler belt 13 an appropriate tension. Therefore, when the crawler belt 13 is deformed in accordance with the ups and downs of the ground or the like during traveling of the hydraulic excavator 1, the distance between the idler wheel 10 and the drive wheel 11 is appropriately changed by the spring member 24 being bent and deformed, 13 is configured to be able to suppress an excessive load (tension) from acting.

  The grease chamber 25 is formed in the tube 19 by the yoke side rod 20 and the frame side rod 22. The grease chamber 25 is defined between the other end of the yoke-side rod 20 and one end of the frame-side rod 22. The grease chamber 25 is filled or discharged with grease through a greasing valve 28 and an axial grease passage 26, which will be described later, and the frame-side rod 22 with respect to the tube 19 is changed according to the amount of grease filled in the grease chamber 25. The protrusion amount is adjusted.

  The axial grease passage 26 is provided in the frame-side rod 22. As shown in FIGS. 4 and 5, the axial grease passage 26 extends in the axial direction at the center of the frame-side rod 22, and one end 26 </ b> A of the axial grease passage 26 is connected to an end surface 22 </ b> B on one end of the frame-side rod 22. It is open and communicates with the grease chamber 25. The other end 26B of the axial grease passage 26 is bent radially from the center of the frame-side rod 22 toward the rod insertion tube 23C of the holder 23, and opens to the outer peripheral surface of the rod insertion tube 23C. On the other end of the rod insertion tube 23C and the frame-side rod 22 inserted in the rod insertion tube 23C, a valve mounting hole 27 is formed coaxially with the other end 26B of the axial grease passage 26. . A female screw portion 27A is formed on the inner peripheral surface of the valve mounting hole 27, and a male screw portion 28A of a greasing valve 28 is screwed into the female screw portion 27A.

  The greasing valve 28 is mounted in a valve mounting hole 27 formed in the rod insertion tube 23 </ b> C of the holder 23 and the frame side rod 22. As shown in FIG. 4, a male screw portion 28 </ b> A is formed on the outer peripheral surface of the greasing valve 28, and the male screw portion 28 </ b> A is screwed into the female screw portion 27 </ b> A of the valve mounting hole 27 to lubricate the valve mounting hole 27. A valve 28 is mounted. The greasing valve 28 has a grease nipple 28B, and by connecting a greasing tool (not shown) such as a grease gun to the grease nipple 28B, the grease nipple 28B passes through the grease chamber 25 through the grease passage 26 in the axial direction. Is filled with grease. The greasing valve 28 has a check valve structure (not shown), and the grease filled in the grease chamber 25 is retained in the grease chamber 25 by the check valve structure.

  Next, the radial vertical grease passage 29, the radial horizontal grease passage 30, and the annular groove 31 provided in the frame-side rod 22 will be described with reference to FIGS.

  A radial vertical grease passage 29 and a radial horizontal grease passage 30 as radial grease passages are provided at one end of the frame-side rod 22 so as to radially penetrate therethrough. The radial vertical grease passage 29 and the radial horizontal grease passage 30 allow a part of the grease supplied to the grease chamber 25 through the axial grease passage 26 to slide between the outer peripheral surface 22 </ b> A of the frame side rod 22 and the tube 19. It is supplied to the sliding surface of the hole 19A with the inner peripheral surface 19D.

  Here, the radial vertical grease passage 29 penetrates the frame-side rod 22 upward and downward (vertically) in a state where the crawler belt 13 of the lower traveling body 2 is in contact with the ground (the state of FIG. 2). Are located in An intermediate portion of the radial vertical grease passage 29 communicates with the axial grease passage 26, and one end 29A and the other end 29B in the longitudinal direction of the radial vertical grease passage 29 are respectively formed on a groove bottom 31A of an annular groove 31 described later. It is open. On the other hand, the radial lateral grease passage 30 is disposed so as to penetrate the frame-side rod 22 in the left and right directions (horizontal direction) in a state where the crawler belt 13 of the lower traveling body 2 is in contact with the ground. An intermediate portion of the radial lateral grease passage 30 communicates with the axial grease passage 26, and one end 30A and the other end 30B of the radial lateral grease passage 30 in the longitudinal direction open to the groove bottom surface 31A of the annular groove 31, respectively. ing.

  Accordingly, the radial vertical grease passage 29 and the radial horizontal grease passage 30 intersect at a right angle (cross shape) with the axial grease passage 26 as a center, and one end 29A and the other end 29B of the radial vertical grease passage 29 and the radial One end 30A and the other end 30B of the directional lateral grease passage 30 are opened at a groove bottom surface 31A of the annular groove 31 at an angular interval of 90 ° from each other. Thus, when the grease is filled into the grease chamber 25 from the greasing valve 28 through the axial grease passage 26, a part of the grease is transferred to the annular groove 31 through the radial vertical grease passage 29 and the radial horizontal grease passage 30. It is supplied from the annular groove 31 to between the outer peripheral surface 22A of the frame side rod 22 and the inner peripheral surface 19D of the tube 19 (rod sliding hole 19A). That is, the grease can be supplied to the sliding surface between the outer peripheral surface 22A of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19 at the same time as the operation of filling the grease into the grease chamber 25.

  Here, as shown in FIG. 6, the axial dimension L from the end face 22 </ b> B on one end side of the frame-side rod 22 to the hole center of the radial vertical grease passage 29 and the radial horizontal grease passage 30 is equal to the frame-side rod 22. It is set to 10% or less of the total length in the axial direction. That is, the radial vertical grease passage 29 and the radial horizontal grease passage 30 are formed in a narrow range which is deviated toward the end face 22B at one end with respect to the entire length of the frame-side rod 22. Thus, the grease is directly supplied to the outer peripheral surface 22A on one end side of the frame-side rod 22 where fretting wear is likely to occur.

  The annular groove 31 is formed between both ends (one end 29A and the other end 29B) of the radial vertical grease passage 29 and both ends (one end 30A and the other end 30B) of the radial vertical grease passage 29 in the outer peripheral surface 22A of the frame-side rod 22. The opening is provided over the entire circumference. The annular groove 31 has a shape recessed in the radial direction with respect to the outer peripheral surface 22A of the frame-side rod 22, and holds grease between the annular groove 31 and the inner peripheral surface 19D of the tube 19 in which the frame-side rod 22 is inserted. Things.

  Here, the annular groove 31 has a groove width W larger than the diameter of the radial vertical grease passage 29 and the radial horizontal grease passage 30, and the groove bottom surface 31 </ b> A of the annular groove 31 is the outer peripheral surface 22 </ b> A of the frame side rod 22. Is part of. Accordingly, one end 29A and the other end 29B of the radial vertical grease passage 29 and one end 30A and the other end 30B of the radial horizontal grease passage 30 are open to the groove bottom 31A of the annular groove 31, respectively. The annular groove 31 holds the grease supplied to the outer peripheral side of the frame-side rod 22 through the radial vertical grease passage 29 and the radial lateral grease passage 30 between the grease and the inner peripheral surface 19 </ b> D of the tube 19. Thus, a configuration is provided in which the space between the outer peripheral surface 22A at one end of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19 can be appropriately lubricated.

  As shown in FIGS. 8 and 9, a rod-side tapered surface 22 </ b> C whose diameter gradually decreases toward the grease chamber 25 is formed on an outer peripheral surface 22 </ b> A at one end of the frame-side rod 22. Also, two portions of the groove bottom 31A of the annular groove 31 where both sides in the groove width direction and the outer peripheral surface 22A of the frame-side rod 22 intersect gradually from the outer peripheral surface 22A of the frame-side rod 22 toward the groove bottom 31A. They are formed as groove-side tapered surfaces 31B and 31C whose diameters are reduced. In this case, the inclination angle θ1 of the rod-side tapered surface 22C with respect to the outer peripheral surface 22A of the frame-side rod 22, the inclination angle θ2 of the groove-side tapered surface 31B with respect to the outer peripheral surface 22A of the frame-side rod 22, and the outer peripheral surface of the frame-side rod 22 The inclination angle θ3 of the groove-side tapered surface 31C with respect to 22A is set to the same value.

  Further, a corner 22D1 at which the end surface 22B of the frame-side rod 22 and the rod-side tapered surface 22C intersect, a corner 22D2 at which the outer peripheral surface 22A of the frame-side rod 22 intersects with the rod-side tapered surface 22C, A corner 22D3 at which the outer peripheral surface 22A intersects with the groove side taper surface 31B, a corner 22D4 at which the groove bottom 31A of the annular groove 31 intersects with the groove side taper surface 31B, a groove bottom 31A of the annular groove 31 and groove side taper surface. The corner 22D5 where the cross section 31C intersects and the corner 22D6 where the outer peripheral surface 22A of the frame side rod 22 intersects the groove side taper surface 31C are arc-shaped chamfers having the same radius R.

  As a result, a part of the grease filled in the grease chamber 25 through the axial grease passage 26 moves along the rod-side tapered surface 22C provided at one end of the frame-side rod 22 to the outer peripheral surface of the frame-side rod 22. It is guided smoothly between 22A and the inner peripheral surface 19D of the tube 19. The grease supplied from the axial grease passage 26 into the annular groove 31 through the radial vertical grease passage 29 and the radial horizontal grease passage 30 is provided on the groove side taper surfaces provided on both sides of the annular groove 31 in the groove width direction. It is smoothly guided between the outer peripheral surface 22A of the frame side rod 22 and the inner peripheral surface 19D of the tube 19 along 31B and 31C.

  In this case, the inclination angle θ1 of the rod-side tapered surface 22C, the inclination angle θ2 of the groove-side tapered surface 31B, and the inclination angle θ3 of the groove-side tapered surface 31C are set to be equal to each other, and the respective corners 22D1 ~ 22D6 are chamfered with a radius R equal to each other. Thus, the grease guided to the outer peripheral surface 22A of the frame side rod 22 along the rod side tapered surface 22C, the grease guided to the outer peripheral surface 22A of the frame side rod 22 along the groove side tapered surface 31B, and the groove side taper The grease guided to the outer peripheral surface 22A of the frame-side rod 22 along the surface 31C is equalized, and the entire circumference is provided between the outer peripheral surface 22A at one end of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19. Grease can be supplied without any excess or shortage.

  When air remains in the tube 19 in a state where the grease is filled in the grease chamber 25, for example, an external force acts on the idler wheel 10 when the hydraulic excavator 1 travels, so that the inside of the grease chamber 25 is reduced. Is pressurized between the yoke-side rod 20 and the frame-side rod 22. Thus, the grease in the grease chamber 25 is supplied from the axial grease passage 26 to the annular groove 31 through the radial longitudinal grease passage 29 and the radial lateral grease passage 30 by utilizing the external force acting on the idler wheel 10, The structure is such that the space between the outer peripheral surface 22A at one end of the frame side rod 22 and the inner peripheral surface 19D of the tube 19 can be constantly lubricated.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration, and its operation will be described below.

  The hydraulic excavator 1 drives the crawler belt 13 wound around the drive wheel 11 and the idler wheel 10 by rotating the drive wheel 11 of the lower traveling body 2, and travels to a work place. Then, the hydraulic excavator 1 can perform earth excavation work and the like by raising and lowering the front device 4 while rotating the upper swing body 3 at the work place.

  During traveling of the excavator 1, the crawler belt tension adjusting device 16 constantly presses the idler wheel 10 in a direction away from the drive wheel 11 by the spring force of the spring member 24, and gives the crawler belt 13 an appropriate tension. Therefore, when the crawler belt 13 is deformed according to the ups and downs of the ground or the like during traveling of the hydraulic excavator 1, the distance between the idler wheel 10 and the drive wheel 11 is appropriately changed by the spring member 24 being bent and deformed. As a result, the application of an excessive load to the crawler belt 13 can be suppressed, and the hydraulic excavator 1 can run stably even on uneven terrain.

  Here, the tension (tension) of the crawler belt 13 can be adjusted according to the amount of grease filled in the grease chamber 25 of the tension adjusting cylinder 18. That is, the tension of the crawler belt 13 can be increased by increasing the filling amount of the grease and extending the frame-side rod 22 from the tube 19. On the other hand, the tension of the crawler belt 13 can be reduced by reducing the filling amount of the grease and reducing the frame-side rod 22 into the tube 19.

  When filling the grease chamber 25 with grease, a greasing tool (not shown) such as a grease gun is inserted into the side frame 7 through a working opening 7E provided in the side frame 7 of the lower traveling body 2. And the grease nipple 28B of the greasing valve 28. By operating the greasing tool in this state, the grease can be filled into the grease chamber 25 from the greasing valve 28 through the axial grease passage 26 of the frame-side rod 22 and the like.

  At this time, a part of the grease filled in the grease chamber 25 through the axial grease passage 26 is supplied to the annular groove 31 through the radial vertical grease passage 29 and the radial horizontal grease passage 30, and from the annular groove 31 to the frame side. It is supplied to the sliding surface between the outer peripheral surface 22A of the rod 22 and the inner peripheral surface 19D of the tube 19. Thereby, the space between the outer peripheral surface 22A on one end side of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19 can be appropriately lubricated.

  Therefore, even when the external force acts on the idler wheel 10 when the hydraulic excavator 1 travels, the outer peripheral surface 22 </ b> A on one end side of the frame-side rod 22 hits one side against the inner peripheral surface 19 </ b> D of the tube 19. The occurrence of fretting wear on the outer peripheral surface 22A of the frame-side rod 22 can be suppressed. As a result, the durability and reliability of the crawler belt tension adjusting device 16 can be improved.

  In this case, a rod-side tapered surface 22C is formed on the outer peripheral surface 22A on one end side of the frame-side rod 22, and both sides in the groove width direction of the groove bottom surface 31A of the annular groove 31 and the outer peripheral surface 22A of the frame-side rod 22 are formed. The two intersecting portions are formed as groove-side tapered surfaces 31B and 31C, respectively. As a result, a part of the grease filled in the grease chamber 25 through the axial grease passage 26 is moved along the rod-side tapered surface 22C between the outer peripheral surface 22A of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19. You can lead between. Further, the grease supplied from the axial grease passage 26 into the annular groove 31 through the radial longitudinal grease passage 29 and the radial lateral grease passage 30 is moved along the groove-side tapered surfaces 31B and 31C to the outer periphery of the frame-side rod 22. It can be guided between the surface 22A and the inner peripheral surface 19D of the tube 19.

  In this case, the inclination angle θ1 of the rod-side tapered surface 22C, the inclination angle θ2 of the groove-side tapered surface 31B, and the inclination angle θ3 of the groove-side tapered surface 31C are set to the same value. Thus, the grease guided to the outer peripheral surface 22A of the frame side rod 22 along the rod side tapered surface 22C, the grease guided to the outer peripheral surface 22A of the frame side rod 22 along the groove side tapered surface 31B, and the groove side taper The grease guided to the outer peripheral surface 22A of the frame side rod 22 along the surface 31C can be equalized. As a result, grease can be supplied over the entire circumference between the outer peripheral surface 22A at one end of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19 without excess or shortage. Between the outer peripheral surface 22A and the inner peripheral surface 19D of the tube 19 can be efficiently lubricated.

  The radial vertical grease passage 29 is disposed so as to penetrate the frame-side rod 22 upward and downward with the crawler belt 13 of the excavator 1 grounded to the ground. Grease can be positively supplied to the upper surface side and the lower surface side of the frame side rod 22 through 29. Therefore, when the hydraulic excavator 1 travels on uneven terrain, the external force in the upward and downward directions repeatedly acts on the idler wheel 10 due to the lifting from the ground or the like, so that the upper surface side and the lower surface side of the frame side rod 22. Even if a local load acts on the inner peripheral surface 19 </ b> D of the tube 19, the grease is positively supplied to the upper surface side and the lower surface side of the frame side rod 22, so that the upper surface of the frame side rod 22 is Wear on the side and the lower surface side can be suppressed.

  Further, when air remains in the tube 19 in a state where the grease is filled in the grease chamber 25, for example, an external force acts on the idler wheel 10 when the hydraulic excavator 1 travels, so that the inside of the grease chamber 25 is reduced. Can be pressurized between the yoke-side rod 20 and the frame-side rod 22. Thereby, the grease in the grease chamber 25 is supplied from the axial grease passage 26 to the annular groove 31 through the radial longitudinal grease passage 29 and the radial lateral grease passage 30 by utilizing the external force acting on the idler wheel 10. Thus, it is possible to always lubricate between the outer peripheral surface 22A on one end side of the frame side rod 22 and the inner peripheral surface 19D of the tube 19.

  Thus, according to the present embodiment, one end of the frame-side rod 22 provided with the axial grease passage 26 is provided with a radial vertical grease passage 29 which penetrates in the radial direction and has an intermediate portion communicating with the axial grease passage 26. And a radial lateral grease passage 30. An inner peripheral surface 19 </ b> D of the tube 19 is provided at a portion of the outer peripheral surface 22 </ b> A of the frame side rod 22 where both ends of the radial vertical grease passage 29 and the radial lateral grease passage 30 are open. An annular groove 31 for holding grease is provided between them.

  Thus, when the grease is filled into the grease chamber 25 through the axial grease passage 26 in order to adjust the tension of the crawler belt 13, a part of the grease is annularly formed through the radial vertical grease passage 29 and the radial horizontal grease passage 30. It is supplied to the groove 31 and is held between the annular groove 31 and the inner peripheral surface 19 </ b> D of the tube 19. Therefore, the sliding surface between the outer peripheral surface 22A of the frame side rod 22 and the inner peripheral surface 19D of the tube 19 can be lubricated with grease. As a result, the wear of the frame-side rod 22 can be suppressed, and the durability of the crawler belt tension adjusting device 16 can be increased. Moreover, since the grease can be supplied to the sliding surface between the outer peripheral surface 22A of the frame side rod 22 and the inner peripheral surface 19D of the tube 19 at the same time as the operation of filling the grease into the grease chamber 25, the workability is improved. be able to.

  Further, the radial vertical grease passage 29 and the radial horizontal grease passage 30 are provided so as to penetrate the frame-side rod 22 in the radial direction, and an intermediate portion thereof communicates with the axial grease passage 26. One greasing valve 28 common to 26, 29, 30 can be used. For this reason, the grease passage and the greasing passage extending in the axial direction are separately provided in the frame-side rod as in the prior art, for example. Can be simplified.

  In the present embodiment, the radial vertical grease passage 29 is arranged so as to penetrate the frame-side rod 22 upward and downward with the crawler belt 13 of the excavator 1 being in contact with the ground. Thereby, grease can be positively supplied to the upper surface side and the lower surface side of the frame side rod 22 through the radial vertical grease passage 29. Therefore, when the hydraulic excavator 1 travels on uneven terrain, an external force in the upward and downward directions acts on the idler wheel 10, and the upper and lower sides of the frame-side rod 22 and the inner peripheral surface 19 </ b> D of the tube 19. On the other hand, even if a local load acts, the wear on the upper surface side and the lower surface side of the frame side rod 22 can be suppressed.

  In the present embodiment, a rod-side tapered surface 22 </ b> C whose diameter gradually decreases toward the grease chamber 25 is provided on an outer peripheral surface 22 </ b> A on one end side of the frame-side rod 22. The respective portions where both sides in the width direction intersect with the outer peripheral surface 22A of the frame-side rod 22 are groove-side tapered surfaces 31B whose diameter gradually decreases from the outer peripheral surface 22A of the frame-side rod 22 toward the groove bottom surface 31A of the annular groove 31, 31C.

  As a result, a part of the grease filled in the grease chamber 25 through the axial grease passage 26 is moved along the rod-side tapered surface 22C between the outer peripheral surface 22A of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19. You can lead between. Further, the grease supplied from the axial grease passage 26 into the annular groove 31 through the radial longitudinal grease passage 29 and the radial lateral grease passage 30 is moved along the groove-side tapered surfaces 31B and 31C to the outer periphery of the frame-side rod 22. It can be guided between the surface 22A and the inner peripheral surface 19D of the tube 19. As a result, the space between the outer peripheral surface 22A on one end side of the frame-side rod 22 and the inner peripheral surface 19D of the tube 19 can be efficiently lubricated with sufficient grease.

  In the embodiment, a case is illustrated in which two radial grease passages including a radial longitudinal grease passage 29 and a radial lateral grease passage 30 are provided in the frame-side rod 22. However, the present invention is not limited to this. For example, as in a modified example shown in FIG. 10, the radial grease passage is formed by one radial longitudinal grease passage 29 penetrating the frame side rod 22 upward and downward. You may comprise.

  Further, the embodiment exemplifies a case in which a holder 23 formed as a separate member from the frame-side rod 22 is integrally fixed to the frame-side rod 22 by press-fitting or the like. However, the present invention is not limited to this, and for example, a configuration using a frame-side rod integrally formed with a holder may be adopted.

  Furthermore, in the embodiment, the hydraulic excavator 1 is illustrated as a tracked vehicle, but the present invention is not limited to this, and can be widely applied to tracked vehicles having crawler tracks such as hydraulic cranes and bulldozers. it can.

1 hydraulic excavator (tracked vehicle)
Reference Signs List 5 track frame 7 side frame 8 partition wall 10 idle wheel 11 drive wheel 13 crawler belt 16 crawler belt tension adjusting device 17 yoke 18 tension adjusting cylinder 19 tube 20 yoke side rod 22 frame side rod 22C rod side taper surface 25 grease chamber 26 axial grease passage 29 Radial vertical grease passage (radial grease passage)
30 radial grease passage (radial grease passage)
31 annular groove 31A groove bottom surface 31B, 31C groove side taper surface

Claims (2)

A side frame that constitutes a track frame and extends forward and rearward, an idle wheel provided on one end of the side frame, a drive wheel provided on the other end of the side frame, the idle wheel and the drive A crawler belt wound around a wheel, a partition provided in the side frame away from the idler wheel toward the drive wheel, and a crawler belt provided between the partition and the idler wheel. With a crawler tension adjustment device to adjust the tension,
The crawler belt tension adjusting device is provided on one end side of the side frame so as to be movable forward and rearward, the yoke to which the idler wheel is attached, and a tension adjusting cylinder provided between the partition and the yoke. A spring member provided between a spring receiving portion of the tension adjusting cylinder and a spring receiving portion of the yoke to urge the yoke in a direction away from the drive wheels,
The tension adjusting cylinder includes a tube provided in the side frame, a yoke-side rod having one end inserted through the yoke so as to be relatively movable and the other end inserted into the tube, and one end inserted into the tube. A frame-side rod that is inserted and the other end of which abuts against the partition wall; a grease chamber formed in the tube by the yoke-side rod and the frame-side rod; A track-type vehicle comprising an axial grease passage having one end communicated with the grease chamber and the other end opened to the outside of the frame-side rod.
On the frame side rod at one end of the frame side rod, provided through in the downward direction, the radial direction in which the opposite ends with sites halfway in communication with the axial grease passage opening to the outer peripheral surface of the frame side rod A vertical grease passage,
The frame-side rod is provided on one end side of the frame-side rod so as to penetrate the frame-side rod in the left and right directions, and a radial direction in which an intermediate portion communicates with the axial grease passage and both ends open to the outer peripheral surface of the frame-side rod. A horizontal grease passage,
The outer circumferential surface of the frame-side rod is provided over the entire circumference in a portion where both ends of the radial vertical grease passage and the radial horizontal grease passage are open, and holds grease between the inner circumferential surface of the tube. and an annular groove seen including that,
The axial dimension from the end face of the one end side of the frame side rod to the hole center of the radial vertical grease passage and the radial horizontal grease passage is 10% or less with respect to the entire axial length of the frame side rod. A tracked vehicle characterized by the following. An outer peripheral surface on one end side of the frame-side rod is provided with a rod-side tapered surface that gradually decreases in diameter toward the grease chamber,
The respective portions of the groove bottom of the annular groove where both sides in the groove width direction intersect with the outer peripheral surface of the frame-side rod gradually decrease in diameter from the outer peripheral surface of the frame-side rod toward the groove bottom of the annular groove. The tracked vehicle according to claim 1, wherein the track-type vehicle is formed as a groove-side tapered surface.

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