Crawler connection device

Abstract

To provide a crawler connection device excellent in durability.SOLUTION: A crawler link 21 has a through hole 21a, and has a first notch 21b in an inner peripheral surface of the through hole 21a. A master pin 22 is inserted into the through hole 21a of the crawler link 21, and has a second notch 22b in an outer peripheral surface. A knock pin 25 is disposed with one end 25a on an opening side in a first concave part 24 constituted by the first notch 21b and the second notch 22b and having an opening at an end of the through hole 21a. A snap ring 26 has a C shape, and is disposed with a gap from the one end 25a of the knock pin 25 or abutted on the one end 25a. The crawler link 21 has a rotation limitation part RL that is disposed within a rotation trajectory RT in a circumferential direction of the snap ring 26 and limits a rotation range of the snap ring 26.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a track linkage. [Background technology]

[0002] Hydraulic excavators, bulldozers, and the like having tracks are known as working machines. The tracks include a track link chain to which a plurality of track links are connected. When the tracks are detached from the traveling device, the track link chain is released from the connection. One method for releasing the connection of the track link chain is to remove, for example, a master pin that connects the track links from the track link.

[0003] A technique for releasing the connection between track links using a master pin is described, for example, in JP 2013-244783 A (Patent Document 1). In Patent Document 1, a knock pin is inserted into a recess formed by a notch in the track link and a notch in the master pin to prevent the master pin from rotating along with the track link. A snap ring is attached to the outer periphery of the master pin to prevent the knock pin from slipping out of the recess. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-244783 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration described in Patent Document 1, the snap ring rotates in the circumferential direction relative to the master pin due to vibrations while the work machine is in operation (including while it is traveling). This rotation may cause the weaker part of the snap ring to move to a position where an unbalanced load is applied. For this reason, the track coupling device is required to have even greater durability.

[0006] An object of the present disclosure is to provide a crawler connection device having excellent durability.

Means for Solving the Problems

[0007] The crawler connection device of the present disclosure is a crawler connection device for connecting a plurality of crawler links to form an endless crawler, and includes a crawler link, a master pin, a knock pin, and a snap ring. The crawler link has a pin through-hole and a first notch on the inner peripheral surface of the pin through-hole. The master pin is inserted into the pin through-hole of the crawler link and has a second notch on the outer peripheral surface. The knock pin is disposed with one end face facing the opening side in a first recess formed by the first notch and the second notch and having an opening at the end of the pin through-hole. The snap ring has a C-shaped configuration and is disposed with a gap from or in contact with one end face of the knock pin. The crawler link is disposed within the circumferential rotation locus of the snap ring and has a rotation restricting portion for restricting the rotation range of the snap ring.

Advantages of the Invention

[0008] According to the present disclosure, a crawler connection device having excellent durability can be realized.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] In the specification and drawings, the same components or corresponding components are denoted by the same reference numerals, and duplicate explanations are not repeated. Also, in the drawings, for convenience of explanation, the configuration may be omitted or simplified in some cases. Further, at least a part of the embodiment and the modification may be arbitrarily combined with each other.

[0012] <Configuration of Working Machine>

[0013] The configuration of the working machine in one embodiment of the present disclosure will be described. Hereinafter, a hydraulic excavator will be described as an example of a working machine to which the idea of the present disclosure is applicable, but the present disclosure is applicable to working machines having crawlers such as bulldozers other than hydraulic excavators.

[0014] FIG. 1 is a diagram schematically showing the configuration of a working machine according to an embodiment of the present disclosure. As shown in FIG. 1, the working machine (hydraulic excavator) 1 of the present embodiment mainly includes a traveling body 2, a revolving body 3, and a working device 4. The traveling body 2 is configured such that the working machine (hydraulic excavator) 1 travels when a pair of left and right crawlers 10 are rotationally driven. The revolving body 3 is rotatably installed on the traveling body 2. The working device 4 is pivotally supported on the front side of the revolving body 3 so as to be rotatable. The working device 4 has, for example, a boom, an arm, a bucket, a hydraulic cylinder, and the like.

[0015] The traveling body 2 and the revolving body 3 mainly constitute the working machine body. The revolving body 3 has a cab 5 on the front left side (front side of the vehicle) and an engine room 6 for housing an engine and a counterweight 7 on the rear side (rear side of the vehicle). Here, the front and rear, left and right of the vehicle are based on the operator sitting in the cab 5.

[0016] As shown in FIG. 2, the traveling body 2 mainly includes a crawler 10, a slewing device 11, a track frame 12, an idler wheel (idler) 13, a drive wheel (sprocket) 14, an upper turning wheel 15, and a lower turning wheel 16.

[0017] The crawler 10 has a crawler link chain 20 and a track shoe 30 attached to the crawler link chain 20. The slewing device 11 is configured to enable the revolving body 3 (FIG. 1) to slew and is provided at the upper end of the traveling body 2. The track frame 12 is provided so as to extend in the vehicle front-rear direction on both sides of a center frame that serves as a mounting base for the slewing device 11.

[0018] The idler wheel 13 is rotatably provided at the front end of the track frame 12, and the drive wheel 14 is rotatably driven at the rear end of the track frame 12. A plurality of upper turning wheels 15 are provided on the upper surface side of the track frame 12, and a plurality of lower turning wheels 16 are provided on the lower surface side of the track frame 12. Further, a ladder 17 for lifting may be attached to the traveling body 2. Note that the ladder 17 for lifting is not shown in FIG. 1.

[0019] The crawler belt 10 is wound around the idler wheel 13 and the drive wheel 14. The crawler belt 10 is also supported by the upper turning wheel 15 and the lower turning wheel 16 arranged between the idler wheel 13 and the drive wheel 14. The crawler link chain 20 is engaged with the drive wheel 14 and driven, whereby the crawler plate 30 is rotationally driven. In this way, the crawler belt 10 is rotationally driven. Thereby, the traveling body 2 runs by itself.

[0020] <Configuration of Crawler Belt>

[0021] FIG. 3 is a partially exploded perspective view schematically showing the configuration of the crawler belt included in the traveling body of FIG. 2. As shown in FIG. 3, the crawler belt 10 has a crawler link chain 20 and a plurality of crawler plates 30. The crawler link chain 20 mainly has a crawler link 21, a master pin 22, a knock pin 25, a snap ring 26, a crawler pin 34, a crawler bushing 41, and a seal ring 42.

[0022] The crawler belt 10 is formed in a ring shape by connecting a plurality of crawler links 21 in an endless manner. The crawler plates 30 are fixed to the ground contact surface (outer surface) side of each of the plurality of crawler links 21. Bolts 43 are inserted through the through holes provided in the crawler plates 30 and the crawler links 21 from the outer surface side of the crawler plates 30. Nuts 44 are screwed onto the tip ends of the bolts 43 on the non-ground contact surface (inner surface) side of the crawler links 21. The crawler plates 30 are fixed to the ground contact surface of the crawler links 21 by the bolts 43 and the nuts 44.

[0023] The plurality of crawler links 21 included in the crawler link chain 20 have a pair of crawler links 21 (the first crawler link 211 and the second crawler link 212) facing each other in the crawler width direction X. The crawler width direction X is a direction orthogonal to the extending direction Y in which the crawler belt 10 extends in an endless manner and is the longitudinal direction of the crawler plate 30. The first crawler link 211 and the second crawler link 212 are arranged parallel to each other with a space therebetween in the crawler width direction X. The first crawler link 211 and the second crawler link 212 are formed symmetrically. A common crawler plate 30 is fixed to the first crawler link 211 and the second crawler link 212.

[0024] A plurality of first crawler links 211 are arranged in a row along the extending direction Y. Each of the plurality of first crawler links 211 arranged in a row has the same shape as each other. Also, a plurality of second crawler links 212 are arranged in a row along the extending direction Y. Each of the plurality of second crawler links 212 arranged in a row has the same shape as each other. Thus, the plurality of crawler links 21 are arranged in two rows, namely, a row composed of the plurality of first crawler links 211 and a row composed of the plurality of second crawler links 212.

[0025] One and the other crawler links 21 adjacent to each other in the same row are arranged such that the pin through-hole 21a of one crawler link 21 and the bush through-hole 21c of the other crawler link 21 communicate with each other. A cylindrical crawler bush 41 is press-fitted into the bush through-hole 21c of one crawler link 21. A crawler pin 34 is inserted into the crawler bush 41 and press-fitted into the pin through-hole 21a of the other crawler link 21. In this way, one and the other crawler links 21 arranged in the row direction are connected to each other.

[0026] A common crawler pin 34 is press-fitted into each of the pin through-holes 21a of the first crawler link 211 and the second crawler link 212 facing each other in the crawler width direction X. A common crawler bush 41 is press-fitted into each of the bush through-holes 21c of the first crawler link 211 and the second crawler link 212 facing each other in the crawler width direction X. In this way, the two rows of crawler links 21 are connected to each other by the crawler pins 34 and the crawler bushes 41.

[0027] As shown in FIG. 6, a seal ring 42 is arranged between the end of the crawler bush 41 into which the crawler pin 34 is inserted and the crawler link 21.

[0028] A plurality of crawler links 21 are pivotally supported by crawler pins 34 and are connected to each other so as to be rotatable relative to each other, forming a belt-shaped crawler link chain 20. This belt-shaped crawler link chain 20 is made endless and annular by connecting the crawler links 21 at both ends to each other. The crawler connection device includes the crawler links 21 at the ends of the belt-shaped crawler link chain 20 and is a device for making the crawler link chain 20 endless and annular by connecting the crawler links 21 at both ends to each other. Note that a pin for connecting the crawler links 21 at both ends of the belt-shaped crawler link chain 20 to form an endless chain is called a master pin 22.

[0029] <Crawler connection device>

[0030] Next, the crawler connection device in the present embodiment will be described with reference to FIGS. 3 to 7.

[0031] FIG. 4 is an enlarged view showing the crawler at the P1 portion in FIG. 2. FIG. 5 is an enlarged view around the master pin in FIG. 4. FIG. 6 is a partial cross-sectional view taken along line VI-VI in FIG. 4. FIG. 7 is an enlarged view showing the crawler link and the like at the P2 portion in FIG. 6.

[0032] As shown in FIG. 3, the crawler connection device of the present embodiment includes a crawler link 21, a master pin 22, a knock pin 25, and a snap ring 26.

[0033] As shown in FIG. 6, the crawler link 21 has one end portion E1, the other end portion E2, and an inclined portion IP. The inclined portion IP is disposed between the one end portion E1 and the other end portion E2 and connects the one end portion E1 and the other end portion E2. The crawler link 21 has a pin through hole 21a provided at the one end portion E1. The crawler link 21 has a bush through hole 21c provided at the other end portion E2.

[0034] One end portion E1 of one of the plurality of crawler links 21 arranged in the same column and the other end portion E2 of the other crawler link 21 are arranged so as to be aligned in the crawler width direction X. Thereby, the pin through hole 21a of one crawler link 21 and the bush through hole 21c of the other crawler link 21 communicate with each other.

[0035] A crawler bush 41 is press-fitted into the bush through hole 21c of the other crawler link 21. The crawler bush 41 is formed so as to mesh with the teeth of a drive wheel (sprocket) 14. A seal ring 42 is disposed between the end portion of the crawler bush 41 and one end portion E1 of one crawler link 21. The crawler bush 41 has a cylindrical shape. The seal ring 42 has an annular shape. The seal ring 42 is disposed in a circumferential groove 21f provided at one end portion E1 of the crawler link 21.

[0036] The master pin 22 is inserted into the crawler bush 41 and the seal ring 42. The master pin 22 is inserted into the pin through hole 21a of one crawler link 21 and the bush through hole 21c of the other crawler link 21.

[0037] As shown in FIG. 7, the crawler link 21 has a first notch 21b on the inner peripheral surface of the pin through hole 21a. The first notch 21b is formed so as to lead to a second recess 21e. The first notch 21b extends along the direction (axis A direction) in which the central axis A of the pin through hole 21a extends from the second recess 21e. The first notch 21b has a shape of a part of a substantially cylinder (for example, a semi-cylindrical shape).

[0038] The central axis A is an imaginary straight line that passes through the center of the cylindrical pin through hole 21a and extends in the axial direction of the pin through hole 21a. In a state where the master pin 22 is inserted into the pin through hole 21a, the central axis A passes through the center of the cylindrical master pin 22 and extends in the axial direction of the master pin 22.

[0039] The master pin 22 is a cylindrical component. The master pin 22 has a second notch 22b and a circumferential groove 22c on its outer peripheral surface 22a. The second notch 22b is formed at an end of the master pin 22 in the crawler width direction X. The second notch 22b extends along the direction of the axis A of the master pin 22 from the end of the master pin 22. The second notch 22b has a shape of a part of a substantially cylinder (for example, a semi-cylindrical shape).

[0040] In a state where the master pin 22 is inserted into the pin through-hole 21a, the first notch 21b and the second notch 22b face each other. The first recess 24 is formed from the first notch 21b and the second notch 22b. The first recess 24 has a cylindrical internal space. The first recess 24 has an opening at an end of the pin through-hole 21a in the crawler width direction X. The central axis B of the first recess 24 is parallel to the direction of the axis A of the pin through-hole 21a. The first recess 24 is a portion for inserting the knock pin 25.

[0041] The knock pin 25 prevents the master pin 22 from being dragged around with respect to the crawler link 21. The knock pin 25 has, for example, a cylindrical shape. The knock pin 25 is disposed within the first recess 24. The cross-sectional shape of the knock pin 25 perpendicular to the axis B direction is the same from one end to the other end in the axis B direction. The height of the knock pin 25 is larger than the diameter. That is, the longitudinal direction of the knock pin 25 is the axis B direction.

[0042] In a state where the knock pin 25 is disposed within the first recess 24, one end face 25a of the knock pin 25 is located on the opening side of the first recess 24. The length of the knock pin 25 is shorter than the depth (length in the axis A direction) of the first recess 24. Since the central axis B of the knock pin 25 is parallel to the central axis A, the insertion / extraction direction of the knock pin 25 with respect to the first recess 24 is the same as the insertion / extraction direction of the master pin 22 with respect to the pin through-hole 21a.

[0043] The circumferential groove 22c is provided annularly on the entire circumference of the outer peripheral surface 22a of the master pin 22. The circumferential groove 22c intersects with the second notch 22b. The circumferential groove 22c is a portion for fitting the snap ring 26. The snap ring 26 prevents the knock pin 25 from coming out of the second notch 22b.

[0044] As shown in FIG. 4, the snap ring 26 has a C-shaped configuration. The snap ring 26 is annular, and a notch is formed in a part thereof. When this notch is widened, for example, with pliers, the snap ring 26 is expanded in diameter. The snap ring 26 is fitted onto the outer peripheral surface of the master pin 22 in the expanded diameter state.

[0045] As shown in FIG. 7, the snap ring 26 is fitted in the circumferential groove 22c of the master pin 22 in a state of being attached to the outer peripheral surface of the master pin 22. The snap ring 26 is separated from one end surface 25a of the knock pin 25 with a gap therebetween, but may be in contact with one end surface 25a of the knock pin 25. The snap ring 26 is located in the direction of coming out of the first recess 24 of the knock pin 25. Thereby, as shown in FIGS. 4 and 5, in the viewpoint of viewing the crawler belt connecting device from the crawler belt width direction X (the viewpoint of viewing from the direction of the axis A), the snap ring 26 overlaps the knock pin 25. Thereby, the snap ring 26 prevents the knock pin 25 from coming out of the first recess 24.

[0046] Note that one snap ring 26 may be fitted in one circumferential groove 22c, or a plurality of snap rings 26 may be fitted.

[0047] The knock pin 25 is intermediate-fitted in the first recess 24. Thereby, since the knock pin 25 presses the inner peripheral surface of the first recess 24, it is difficult for the knock pin 25 to come out of the first recess 24. The outer peripheral surface of the knock pin 25 is continuously in contact with the first recess 24 over the entire circumference in the circumferential direction.

[0048] On the one hand, the snap ring 26 prevents the knock pin 25 from coming out of the first recess 24. Therefore, the fitting between the knock pin 25 and the first recess 24 may be a clearance fit. In this case, by removing the snap ring 26, the knock pin 25 can be easily removed from the first recess 24.

[0049] As shown in FIG. 6, the knock pin 25 is preferably arranged on the bushing through-hole 21c side with respect to the pin through-hole 21a in a single crawler link 21. On the bushing through-hole 21c side with respect to the pin through-hole 21a, the crawler link 21 can be formed thicker than the side opposite to the bushing through-hole 21c side. Therefore, by arranging the first notch 21b for inserting the knock pin 25 on the bushing through-hole 21c side with respect to the pin through-hole 21a, the stress acting on the first crawler link 21 can be suppressed. For the above reasons, the first notch 21b is preferably provided at the portion closest to the bushing through-hole 21c side with respect to the pin through-hole 21a.

[0050] The end of the crawler pin 34 is press-fitted into the pin through-hole 21a and firmly fixed by an interference fit. The crawler pin 34 is press-fitted into the pin through-hole 21a at, for example, 160 kN (kilo-newton). On the other hand, in the crawler connection device of the present embodiment, the end of the master pin 22 is press-fitted into the pin through-hole 21a with a force smaller than that of the crawler pin 34 and engaged by an intermediate fit rather than an interference fit. Here, the intermediate fit means a fit in which the maximum allowable dimension of the pin diameter of the master pin 22 is larger than the minimum allowable dimension of the hole diameter of the pin through-hole 21a, and the minimum allowable dimension of the pin diameter is smaller than the maximum allowable dimension of the hole diameter. The intermediate fit is also called a stop fit. That is, the master pin 22 is fixed to such an extent that it does not move by the fitting between the outer peripheral surface 22a and the inner peripheral surface of the pin through-hole 21a. The master pin 22 is press-fitted into the pin through-hole 21a at, for example, 16 kN. The end of the master pin 22 may be engaged with the pin through-hole 21a by a clearance fit. From the viewpoint of the detachability of the master pin 22, it is more preferable that the end of the master pin 22 is clearance-fitted in the pin through-hole 21a.

[0051] In addition, in the crawler connection device of the present embodiment, as shown in FIG. 6, the knock pin 25 and the snap ring 26 may be arranged only on one end side of the master pin 22 in the crawler width direction X. Further, the knock pin 25 and the snap ring 26 may be arranged on both one end side and the other end side of the master pin 22 in the crawler width direction X.

[0052] In addition, in the crawler connection device of the present embodiment, the shape of the knock pin 25 is not limited to a cylinder. The shape of the knock pin 25 may be, for example, a truncated conical shape. In that case, the first recess 24 formed by the first notch 21b of the crawler link 21 and the second notch 22b of the master pin 22 has a shape corresponding to the shape of the knock pin 25.

[0053] The crawler connection device of the present embodiment may be provided on at least one side (the side of the pin through hole 21a) in the extending direction Y of the crawler link 21, but may also be provided on both sides of the crawler link 21 (the side of the pin through hole 21a and the side of the bush through hole 21c). Further, the crawler connection device of the present embodiment may be provided on at least one crawler link 21, but may also be provided on a plurality of crawler links 21 constituting the crawler link chain 20.

[0054] <Rotation restricting portion>

[0055] Next, the rotation restricting portion of the crawler connection device of the present embodiment will be described with reference to FIGS. 5, 8 to 10.

[0056] FIG. 8 is a perspective view shown along the cross section taken along line VIII-VIII of FIG. 5. FIG. 9 is a perspective view of a crawler link and the like shown with the master pin, the snap ring, and the knock pin omitted from FIG. 8. FIG. 10 is a diagram for explaining the rotation restricting portion.

[0057] As shown in FIG. 5, the crawler connection device of the present embodiment has a rotation restricting portion RL. The rotation restricting portion RL is disposed within the circumferential rotation locus RT of the snap ring 26 and restricts the rotation range (rotation angle) of the snap ring 26. The rotation locus RT is a region sandwiched between the circumscribed circle RT1 and the inscribed circle RT2 of the snap ring 26 when viewed from the viewpoint in the direction of the axis A. The circumscribed circle RT1 is a circle that contacts the outermost diameter portion of the snap ring 26 with the central axis A as the center. The inscribed circle RT2 is a circle that contacts the innermost diameter portion of the snap ring 26 with the central axis A as the center.

[0058] The snap ring 26 has a ring portion 26a and a pair of flange portions 26b. The ring portion 26a has a C-shaped configuration. The ring portion 26a has an annular shape with a notch in a part thereof. The ring portion 26a has a first circumferential end portion and a second circumferential end portion in the circumferential direction.

[0059] The pair of flange portions 26b has a first flange portion 26b1 and a second flange portion 26b2. The first flange portion 26b1 is connected to the first circumferential end portion of the ring portion 26a. The first flange portion 26b1 protrudes from the first circumferential end portion of the ring portion 26a toward the outer peripheral side of the ring portion 26a. The second flange portion 26b2 is connected to the second circumferential end portion of the ring portion 26a. The second flange portion 26b2 protrudes from the second circumferential end portion of the ring portion 26a toward the outer peripheral side of the ring portion 26a.

[0060] Each of the first flange portion 26b1 and the second flange portion 26b2 has a plier engaging portion 26c. The plier engaging portion 26c is a portion where a plier is engaged with the snap ring 26 when the snap ring 26 is attached to and detached from the master pin 22. The plier is a tool having a tip shape that can be opened and closed. The plier engaging portion 26c is, for example, a through hole provided in each of the first flange portion 26b1 and the second flange portion 26b2. The through hole as the plier engaging portion 26c may be, for example, circular or polygonal such as rectangular.

[0061] The circumferential direction of the snap ring 26 is the rotational direction when the snap ring 26 is rotated about the central axis A in a state where it is attached to the master pin 22. Further, the rotational locus RT in the circumferential direction of the snap ring 26 is the locus traced by the ring portion 26a and the pair of flange portions 26b of the snap ring 26 when the snap ring 26 is rotated about the central axis A in a state where it is attached to the master pin 22.

[0062] In the viewpoint seen from the direction of the axis A, a second recess 21e is provided between the crawler link 21 and the master pin 22. In the present embodiment, the second recess 21e is formed in the crawler link 21. That is, the crawler link 21 has the second recess 21e. The second recess 21e has a small-diameter recess 21ea and a large-diameter recess 21eb. The rotation restricting portion RL is constituted by, for example, the wall surface of the large-diameter recess 21eb.

[0063] As shown in FIGS. 8 and 9, the small-diameter recess 21ea surrounds the periphery (for example, the entire circumference) of the pin through-hole 21a at the end of the pin through-hole 21a. The small-diameter recess 21ea is connected to the entire outer periphery of the pin through-hole 21a. The small-diameter recess 21ea has a bottom surface B1. The bottom surface B1 serves as the receiving surface of the snap ring 26.

[0064] As shown in FIG. 5, the large-diameter recess 21eb is connected to the small-diameter recess 21ea. The large-diameter recess 21eb is disposed on the outer periphery of the small-diameter recess 21ea. The large-diameter recess 21eb is located on the side of the shoe plate 30 with respect to the small-diameter recess 21ea. That is, the large-diameter recess 21eb is connected to the portion of the small-diameter recess 21ea closest to the shoe plate 30.

[0065] The portion of the master pin 22 on the side opposite to the tread plate 30 side is a portion that meshes with a drive wheel (sprocket) 14 or the like and is a location where a load is likely to be applied. Also, since the extending direction Y is the direction in which the crawler 10 is rotationally driven, a load is also likely to be applied to the portion of the master pin 22 in the extending direction Y. By arranging the large-diameter recess 21eb on the tread plate 30 side with respect to the small-diameter recess 21ea, the large-diameter recess 21eb can be arranged at a position where the load on the crawler link 21 is less likely to be applied.

[0066] The large-diameter recess 21eb has a first outer peripheral wall OW1. The first outer peripheral wall OW1 has a portion separated from the central axis A by a first distance Da. The first outer peripheral wall OW1 has an arc portion with a radius equal to the distance Da from the central axis A. The first distance Da is larger than the distance Dc from the central axis A to the outermost diameter portion of the snap ring 26. The outermost diameter portion of the snap ring 26 is, for example, the outer peripheral end of the flange portion 26b.

[0067] The small-diameter recess 21ea has a second outer peripheral wall OW2. The second outer peripheral wall OW2 has a portion separated from the central axis A by a second distance Db. The second outer peripheral wall OW2 has an arc portion with a radius equal to the distance Db from the central axis A. The second distance Db is smaller than the distance Dc from the central axis A to the outermost diameter portion of the snap ring 26.

[0068] The ring portion 26a of the snap ring 26 has a portion located within the small-diameter recess 26a and a portion located within the circumferential groove 22c when viewed from a perspective in the axial direction A. The pair of flange portions 26b of the snap ring 26 are located within the large-diameter recess 26b when viewed from a perspective in the axial direction A. Each of the plier engagement portions 26c provided on each of the pair of flange portions 26b has a portion located within the large-diameter recess 26b when viewed from a perspective in the axial direction A.

[0069] The rotation restricting portion RL is constituted by, for example, the wall surface of the large-diameter recess 21eb. When the snap ring 26 rotates by a predetermined angle in the circumferential direction about the central axis A, the flange portion 26b of the snap ring 26 interferes with the wall surface of the large-diameter recess 21eb. In this way, the rotation range (rotation angle) of the snap ring 26 is restricted by the wall surface of the large-diameter recess 21eb.

[0070] As shown in FIGS. 8 and 9, the large-diameter recess 21eb is formed deeper in the direction of the axis A than the small-diameter recess 21ea. For this reason, the bottom surface B2 of the large-diameter recess 21eb is located on the surface side opposite to the surface of the crawler link 21 where the second recess 21e is provided, with respect to the bottom surface B1 of the small-diameter recess 21ea.

[0071] A first notch 21b for inserting the knock pin 25 is provided in the bottom surface B1 of the small-diameter recess 21ea. For this reason, the end portion of the first notch 21b in the direction of the axis A opens to the bottom surface B1 of the small-diameter recess 21ea.

[0072] The bottom surface B1 of the small-diameter recess 21ea serves as the receiving surface of the ring portion 26a. The bottom surface B2 of the large-diameter recess 21eb is separated from the flange portion 26b of the snap ring 26 with a gap in the direction of the axis A.

[0073] In the above-described embodiment, the case where the rotation restricting portion RL is constituted by the wall surface of the large-diameter recess 21eb has been described. However, the rotation restricting portion RL is not limited thereto. As shown in FIG. 10, the rotation restricting portion RL may be of any form as long as it is arranged within the circumferential rotation locus RT of the snap ring 26 and restricts the rotation range of the snap ring 26.

[0074] The rotation restricting portion RL may be a recess or a protrusion. The rotation restricting portion RL may be integrally formed with the crawler link 21, or may be formed separately from the crawler link 21.

[0075] The rotation limiting portion RL may have a first rotation limiting portion RL1 located between the first flange portion 26b1 and the knock pin 25 in the rotation direction R1 of the snap ring 26 when viewed from the axis A direction. The rotation limiting portion RL may have a second rotation limiting portion RL2 located between the second flange portion 26b2 and the knock pin 25 in the rotation direction R2 of the snap ring 26 when viewed from the axis A direction. The rotation limiting portion RL may have a third rotation limiting portion RL3 located between the first flange portion 26b1 and the second flange portion 26b2 when viewed from the axis A direction. The rotation limiting portion RL may have the first rotation limiting portion RL1, the second rotation limiting portion RL2, and the third rotation limiting portion RL3, each of which may be independently included, or may be included in any combination.

[0076] In the case where the rotation limiting portion RL3 is provided, when the snap ring 26 rotates in the circumferential direction, the first flange portion 26b1 or the second flange portion 26b2 comes into contact with the rotation limiting portion RL3, thereby stopping the rotation of the snap ring 26. At this time, a force acts in the direction in which the snap ring 26 opens. Therefore, in terms of durability, it is more preferable to provide at least one of the rotation limiting portion RL1 and the rotation limiting portion RL2 on the outside of the C-shaped opening of the snap ring 20, rather than at the opening.

[0077] <Method of disconnecting the track link chain 20>

[0078] Next, a method for disconnecting the crawler belt 10 using the crawler belt connection device of this embodiment will be described.

[0079] 3 and 6, in the track belt connection device of this embodiment, the connection is released by pulling out master pin 22 from pin through hole 21a of each of first track belt link 211 and second track belt link 212 and from adjacent bushing through hole 21c of each of first track belt link 211 and second track belt link 212. As a result, endless annular track belt 10 becomes belt-like.

[0080] The crawler connection device of this embodiment is disconnected in the following procedure. First, the C-shaped notch of the snap ring 26 is expanded by, for example, pliers. As a result, the ring portion 26a of the snap ring 26 is expanded in diameter, and the snap ring 26 is removed from the circumferential groove 22c of the master pin 22 and removed from the master pin 22.

[0081] Subsequently, the knock pin 25 is taken out from the first recess 24. In this state, the master pin 22 is pulled out from either side of the first crawler link 211 and the second crawler link 212. Thereby, the connection of the crawler 10 by the crawler connection device is released.

[0082] Also, when reconnecting the crawler 10, it can be connected in the reverse procedure of the above. First, the master pin 22 is inserted into the pin through holes 21a of each of the first crawler link 211 and the second crawler link 212 and the bush through holes 21c of the first crawler link 211 and the second crawler link 212 adjacent thereto. At this time, the master pin 22 is inserted into the crawler bush 41 press-fitted into the bush through hole 21c. Also, a seal ring 42 is disposed between the end face of the crawler bush 41 and the crawler link 21. Also, the master pin 22 is positioned so that the second notch 22b of the master pin 22 and the first notch 21b of the crawler link 21 constitute the cylindrical first recess 24.

[0083] Subsequently, the knock pin 25 is inserted into the first recess 24. The knock pin 25 is inserted into the first recess 24 so as to be, for example, an intermediate fit or a clearance fit. After this, the snap ring 26 is expanded in diameter by, for example, pliers and fitted into the circumferential groove 22c of the master pin 22. Thereby, the snap ring 26 is attached to the master pin 22 and the crawler 10 is connected. Since the connection and disconnection of the crawler 10 can be performed without using a press, the workability of attaching and detaching the crawler 10 can be improved.

[0084] Even without removing the snap rings 26 on both the one - end side and the other - end side of a single master pin 22, it is possible to pull out the master pin 22 by removing only the snap ring 26 on one side. For this reason, by removing only the snap ring 26 on one side of a single master pin 22, the connection of the crawler belt 10 may be released.

[0085] <Modification Example>

[0086] Next, the configuration of a modification example of the present disclosure will be described with reference to FIGS. 11 and 12.

[0087] FIG. 11 is a view showing a configuration of a modification example in which a circumferential groove for snap - ring locking is provided on the inner peripheral surface of the pin through - hole of the crawler link. FIG. 12 is a cross - sectional view taken along line XII - XII of FIG. 11.

[0088] In the embodiment shown in FIGS. 1 to 10, the circumferential groove 22c for snap - ring locking is provided on the outer periphery of the master pin 22. However, as in the modification example shown in FIGS. 11 and 12, a circumferential groove 21d (FIG. 12) for snap - ring locking may be provided on the inner peripheral surface of the pin through - hole 21a of the crawler link 21. In this modification example, since there is no circumferential groove where stress may concentrate on the outer periphery of the master pin 22, the reliability of the master pin 22 is improved.

[0089] As shown in FIG. 11, also in this modification example, the crawler link 21 is disposed within the circumferential rotation locus RT of the snap ring 26 and has a rotation - limiting portion RL that limits the rotation range of the snap ring 26.

[0090] A second recess 21e is provided between the crawler link 21 and the master pin 22. The second recess 21e has a small-diameter recess 21ea and a large-diameter recess 21eb. The small-diameter recess 21ea is constituted by an annular notch 22d of the master pin 22 and a pin through-hole 21a of the crawler link 21. The annular notch 22d is annularly provided on the entire circumference of the master pin 22 at the end of the master pin 22. The inner circumferential surface of the small-diameter recess 21ea is formed by the outer circumferential surface of the master pin 22. The outer circumferential surface of the small-diameter recess 21ea is formed by the circumferential surface of the pin through-hole 21a. Therefore, the outer circumferential surface of the small-diameter recess 21ea has the same diameter as the circumferential surface of the pin through-hole 21a.

[0091] The large-diameter recess 21eb is connected to the small-diameter recess 21ea. The large-diameter recess 21eb is disposed on the outer peripheral side of a part of the small-diameter recess 21ea as viewed from the central axis A. The large-diameter recess 21eb is located on the side of the tread plate 30 with respect to the small-diameter recess 21ea. That is, the large-diameter recess 21eb is connected to the portion of the small-diameter recess 21ea closest to the tread plate 30.

[0092] The large-diameter recess 21eb has a first outer peripheral wall OW1. The first outer peripheral wall OW1 has a portion separated from the central axis A by a first distance Da. The first distance Da is larger than the distance Dc from the central axis A to the outermost diameter portion of the snap ring 26. The outermost diameter portion of the snap ring 26 is, for example, the outer peripheral end of the flange portion 26b.

[0093] The small-diameter recess 21ea has a second outer peripheral wall OW2. The second outer peripheral wall OW2 is separated from the central axis A by a second distance Db. The second distance Db is smaller than the distance Dc from the central axis A to the outermost diameter portion of the snap ring 26.

[0094] The ring portion 26a of the snap ring 26 has a portion located within the small-diameter recess 26a and a portion located within the circumferential groove 21d of the crawler link 21 when viewed from the perspective in the direction of the axis A. The pair of flange portions 26b of the snap ring 26 are located within the large-diameter recess 26b when viewed from the perspective in the direction of the axis A. Each of the plier engagement portions 26c provided on each of the pair of flange portions 26b has a portion located within the large-diameter recess 26b when viewed from the perspective in the direction of the axis A.

[0095] The rotation limiting portion RL is constituted by, for example, the wall surface of the large-diameter recess 21eb. When the snap ring 26 rotates by a predetermined angle in the circumferential direction about the central axis A, the flange portion 26b of the snap ring 26 interferes with the wall surface of the large-diameter recess 21eb. In this way, the rotation range (rotation angle) of the snap ring 26 is limited by the wall surface of the large-diameter recess 21eb.

[0096] As shown in FIG. 12, in this modification, the bottom surface of the annular notch 22d provided in the master pin 22 serves as the receiving surface of the snap ring 26.

[0097] Note that since the configurations of the modifications other than the above are substantially the same as the configurations of the embodiments shown in FIGS. 1 to 10, the same reference numerals are given to the same components as those of the embodiments among the components of the modifications, and the description thereof will not be repeated.

[0098] In the modification shown in FIG. 11, when the snap ring 26 rotates in the circumferential direction, the rotation of the snap ring 26 stops when the first flange portion 26b1 or the second flange portion 26b2 comes into contact with the rotation limiting portion RL1 or RL2. At this time, a force acts in the closing direction of the snap ring 26. Therefore, it is more preferable in terms of durability that the rotation limiting portion is provided at a position corresponding to the rotation limiting portion RL3 shown in FIG. 10 (the C-shaped opening of the snap ring 20) rather than providing at least one of the rotation limiting portion RL1 and the rotation limiting portion RL2 outside the C-shaped opening of the snap ring 20.

[0099] <Effect>

[0100] Next, the operation and effect of the crawler connection device of the present embodiment will be described.

[0101] FIG. 13 is a diagram for explaining problems in the crawler connection device of the comparative example. In the comparative example shown in FIG. 13, due to the vibration during the operation of the work machine 1, the snap ring 26 rotates circumferentially about the central axis A with respect to the master pin 22. Due to this rotation, the connection portion between the ring portion 26a and the flange portion 26b of the snap ring 26 may be located directly above the knock pin 25 (in the direction of the axis A of the knock pin 25). The knock pin 25 may move in the direction of the axis A. In this case, the knock pin 25 collides with the vicinity of the connection portion between the ring portion 26a and the flange portion 26b due to the movement of the knock pin 25 in the direction of the axis A. The connection portion between the ring portion 26a and the flange portion 26b is more likely to have a lower strength than other parts of the snap ring 26. Therefore, when the knock pin 25 collides with the vicinity of the connection portion between the ring portion 26a and the flange portion 26b, the snap ring 26 may be damaged. When the snap ring 26 is damaged, the snap ring 26 can no longer prevent the knock pin 25 from coming out, and the knock pin 25 falls off. Therefore, an improvement in durability is required for the crawler connection device.

[0102] On the other hand, according to the present embodiment, as shown in FIG. 5, the crawler link 21 is disposed within the circumferential rotation locus RT of the snap ring 26 and has a rotation restricting portion RL within the rotation range of the snap ring 26. As a result, the circumferential rotation of the snap ring 26 with respect to the master pin 22 is restricted, so that the low-strength portion of the snap ring 26 is suppressed from moving to a position where an uneven load is applied and being damaged. Thereby, a crawler connection device excellent in durability can be realized.

[0103] Also, according to the crawler connection device of the present embodiment, as shown in FIG. 3, since the snap ring 26 has a C-shaped configuration, the snap ring 26 can be easily attached to and detached from the master pin 22 or the crawler link 21. Further, unlike a normal crawler pin, the master pin 22 is not fixed to the crawler link 21 by interference fit. Therefore, by detaching the snap ring 26, the master pin 22 can be relatively easily detached from the crawler link 21. Accordingly, the master pin 22 can be detached from the crawler link 21 without using a press machine. Thus, the workability of detaching the crawler 10 is improved.

[0104] Also, a knock pin 25 is disposed in a first recess 24 formed by a first notch 21b of the crawler link 21 and a second notch 22b of the master pin 22. Thereby, the knock pin 25 can be in surface contact with the first notch 21b and the second notch 22b within the first recess 24. For this reason, although the fitting is an intermediate fit or a clearance fit, the master pin 22 is fixed so as not to be rotatable with respect to the crawler link 21. Also, it is possible to prevent the knock pin 25 from hitting only one of the first notch 21b and the second notch 22b. Therefore, it is possible to prevent the first recess 24 from being worn. Thus, since the generation of a gap between the knock pin 25 and the first recess 24 is suppressed, the detachment of the master pin 22 from the crawler link 21 is suppressed.

[0105] Also, the snap ring 26 is provided at a position that blocks the path for the knock pin 25 to come out of the first recess 24. For this reason, the snap ring 26 prevents the knock pin 25 from coming out of the first recess 24. Thus, it is possible to prevent the knock pin 25 from coming out of the first recess 24 and the master pin 22 from rotating relative to the crawler link 21.

[0106] Also, according to the present embodiment, as shown in FIG. 5, the rotation restricting portion RL has a first rotation restricting portion RL1 and a second rotation restricting portion RL2. The first rotation restricting portion RL1 is located between the first flange portion 26b1 and the knock pin 25 in the first direction R1 in the circumferential direction of the snap ring 26. The second rotation restricting portion RL2 is located between the second flange portion 26b2 and the knock pin 25 in the second direction R2 in the circumferential direction of the snap ring 26. Thereby, both the connection portion between the first flange portion 26b1 and the ring portion 26a and the connection portion between the second flange portion 26b2 and the ring portion 26a are prevented from being located directly above the knock pin 25 (in the direction of the axis A of the knock pin 25). For this reason, it is suppressed that the low-strength portion of the snap ring 26 moves to a position where an eccentric load is applied and is damaged.

[0107] Also, according to the present embodiment, as shown in FIG. 5, the second recess 21e has a large-diameter recess 21eb having a first outer peripheral wall OW1 that is farther from the central axis A than the distance Dc from the central axis A to the outermost diameter portion of the snap ring 26, and a small-diameter recess 21ea having a second outer peripheral wall OW2 that is closer to the central axis A than the distance Dc. The outermost diameter portion of the snap ring 26 is located within the large-diameter recess 21eb. Thereby, the outermost diameter portion of the snap ring 26 can move only within the large-diameter recess 21eb and cannot move into the small-diameter recess 21ea.

[0108] Also, according to the present embodiment, as shown in FIG. 5, at least a part of each of the first flange portion 26b1 and the second flange portion 26b2 of the snap ring 26 is disposed within the large-diameter recess 21eb. At least a part of the ring portion 26a is disposed within the small-diameter recess 21ea. Thereby, each of the first flange portion 26b1 and the second flange portion 26b2 can move only within the large-diameter recess 21eb and cannot move into the small-diameter recess 21ea. Since the rotation of the snap ring 26 with respect to the master pin 22 is restricted in this way, it is suppressed that the low-strength portion of the snap ring 26 moves to a position where an eccentric load is applied and is damaged.

[0109] Also, according to the present embodiment, as shown in FIGS. 8 and 9, each of the plier engaging portions 26c of the first flange portion 26b1 and the second flange portion 26b2 has a portion located in a large-diameter recess 21eb deeper than the small-diameter recess 21ea. This makes it easier to engage the pliers with the plier engaging portion 26c.

[0110] Also, according to the present embodiment, as shown in FIG. 5, the outer peripheral wall OW1 of the large-diameter recess 21eb restricts the movable range of the plier engaging portion 26c when the snap ring 26 is attached to and detached from the master pin 22. This can prevent the snap ring 26 from being excessively expanded and deformed when the snap ring 26 is attached to and detached from the master pin 22.

[0111] Also, according to the present embodiment, as shown in FIG. 8, the bottom surface B1 of the small-diameter recess 21ea is configured to be a receiving surface of the ring portion 26a of the snap ring 26 that deforms when the snap ring 26 is attached to and detached from the master pin 22. Since the ring portion 26a can be received by the bottom surface B1 of the small-diameter recess 21ea in this way, an uneven load is suppressed from being applied to the ring portion 26a.

[0112] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the scope of the claims, and it is intended that all modifications within the meaning and scope equivalent to the scope of the claims are included.

Explanation of Reference Numerals

[0113] 1 Working machine, 2 Traveling body, 3 Slewing body, 4 Working implement, 5 Cab, 6 Engine room, 7 Counterweight, 10 Crawler, 11 Slewing device, 12 Truck frame, 13 Idler wheel, 14 Driving wheel, 15 Upper turning wheel, 16 Lower turning wheel, 17 Ladder for lifting, 20 Crawler link chain, 21 Crawler link, 211 First crawler link, 212 Second crawler link, 21a Pin through-hole, 21b First notch, 21c Bush through-hole, 21d, 22c Circumferential groove, 21e Second recess, 21ea Small-diameter recess, 21eb Large-diameter recess, 22 Master pin, 22a Outer peripheral surface, 22b Second notch, 22d Annular notch, 24 First recess, 25 Knock pin, 25a One end face, 26 Snap ring, 26a Ring portion, 26b Flange portion, 26b1 First flange portion, 26b2 Second flange portion, 26c Plier engagement portion, 30 Track shoe, 34 Crawler pin, 41 Crawler bushing, 42 Seal ring, 43 Bolt, 44 Nut, A, B Central axis, B1, B2 Bottom surface, E1 One end portion, E2 The other end portion, IP Italic portion, OW1 First outer peripheral wall, OW2 Second outer peripheral wall, RL Rotation limiting portion, RL1 First rotation limiting portion, RL2 Second rotation limiting portion, RL3 Third rotation limiting portion, RT Rotation locus.

Claims

1. An endless crawler belt connecting device for connecting a plurality of crawler links, comprising: a crawler link having a pin through-hole and a first notch on an inner circumferential surface of the pin through-hole; a master pin inserted into the pin through-hole of the crawler link and having a second notch on an outer circumferential surface; a knock pin having one end face disposed on the opening side in a first recess formed by the first notch and the second notch and having an opening at an end of the pin through-hole; a snap ring having a C-shaped configuration and disposed with a gap from or in contact with the one end face of the knock pin; a rotation restricting portion disposed within a circumferential rotation locus of the snap ring for restricting a rotation range of the snap ring.

2. The snap ring has a C-shaped ring portion, and a first flange portion and a second flange portion protruding to the outer circumferential side from the ring portion at a first circumferential end and a second circumferential end of the ring portion, respectively. The rotation restricting portion has a first rotation restricting portion located between the first flange portion and the knock pin in a first direction in the circumferential direction of the snap ring, and a second rotation restricting portion located between the second flange portion and the knock pin in a second direction opposite to the first direction in the circumferential direction of the snap ring. The crawler belt connecting device according to Claim 1.

3. A second recess is provided between the crawler link and the master pin. The second recess has a large-diameter recess having a first outer peripheral wall farther from the central axis than a distance from the central axis of the pin through-hole to the outermost diameter portion of the snap ring, and a small-diameter recess having a second outer peripheral wall closer to the central axis than the distance. The outermost diameter portion of the snap ring is located within the large-diameter recess. The crawler belt connecting device according to Claim 1.

4. The snap ring has a C-shaped ring portion, and a first flange portion and a second flange portion protruding to the outer circumferential side from the ring portion at a first circumferential end and a second circumferential end of the ring portion, respectively. At least a part of the first flange portion and the second flange portion is disposed within the large-diameter recess, and at least a part of the ring portion is disposed within the small-diameter recess. The crawler belt connecting device according to Claim 3.

5. The large-diameter recess is formed deeper than the small-diameter recess. The snap ring has a plier engaging portion on each of the first flange portion and the second flange portion, and the plier engaging portion has a portion located within the large-diameter recess, the crawler connecting device according to claim 4.

6. The first outer peripheral wall of the large-diameter recess restricts the movable range of the plier engaging portion when the snap ring is detached from the master pin, the crawler connecting device according to claim 5.

7. The bottom surface of the small-diameter recess is configured to be a receiving surface of the ring portion of the snap ring that deforms when the snap ring is detached from the master pin, the crawler connecting device according to claim 5 or claim 6.

Images