Tooth board

Abstract

To provide a tooth board in which the abnormalities of an operation head can be easily detected.SOLUTION: A tooth board 1 comprises plural tooth pieces 10, 20, 30, 40, 50 connected in a longitudinal direction. The tooth pieces 10, 20, 30, 40, 50 comprise adapter connection parts 11, 21, 31, 41, 51 where adapters can be inserted. The adapter connection parts 11, 21, 31, 41, 51 comprise side wall parts 11a, 11b, 51a, 51b facing each other via the adapters. The side wall parts 11a, 51a are formed with head operation holes 11d, 51d where an operation head 71a provided at one end of a fitting pin unit 70 in an axial direction is located, and the side wall parts 11b, 51b are formed with detent holes 11g, 51g where a detent head 73a provided at the other end of the fitting pin unit 70 in an axial direction is located. The head operation holes 11d, 51d of the tooth pieces 10, 50 located at both ends in a longitudinal direction are located so as to expose to both of left and right sides.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tooth disk.

Background Art

[0002] For example, Patent Document 1 discloses a configuration in which teeth are fixed to respective ones of a plurality of adapters arranged at predetermined intervals in a bucket by an attachment pin assembly. This attachment pin assembly is integrated by rotating and fastening the head of a bolt (head 13b in FIGS. 3 to 5 of Patent Document 1) with a tool.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration described in Patent Document 1 above, since all of the plurality of attachment pin assemblies face the same direction, the head of the bolt (operation head) of either one of the two attachment pin assemblies at both ends among the plurality of attachment pin assemblies (the attachment pin assembly for fixing the upper left tooth in FIG. 1 of Patent Document 1) is arranged on the inner side facing the adjacent tooth. Therefore, the operation head cannot be visually recognized from the outside, and it is difficult to detect abnormalities such as loosening or breakage of the operation head.

[0005] The present invention has been made in view of the above actual situation, and an object thereof is to provide a tooth disk that can easily detect abnormalities in the operation head.

Means for Solving the Problems

[0006] To achieve the above object, the tool bit according to the present invention is a tool bit fixed to a plurality of adapters of a bucket by a mounting pin unit, and includes a plurality of tool bits arranged in a state of being connected in the left-right direction, which is the direction in which the plurality of adapters are arranged. Each of the plurality of tool bits includes an adapter connection portion into which the adapter can be inserted. The adapter connection portion includes first and second side wall portions facing each other in the left-right direction via the adapter. On the first side wall portion, a head operation hole in which an operation head rotated by a tool provided at one axial end of the mounting pin unit extending through the adapter in the left-right direction is located is formed. On the second side wall portion, a rotation prevention hole in which a rotation prevention head provided at the other axial end of the mounting pin unit is located is formed. The head operation holes of the left end tool bit and the right end tool bit located at both ends in the left-right direction among the plurality of tool bits are located so as to be exposed to both left and right outer sides.

Effects of the Invention

[0007] According to the present invention, it is possible to provide a tool bit that can easily detect abnormalities in the operation head.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0009] A description will be given of a two-tooth plate according to an embodiment of the present invention with reference to the drawings. As shown in FIG. 3, the two-tooth plate 1 can be attached to the adapters 5a to 5e on the tip side of the bucket 5, and is also called a flat claw. The bucket 5 is rotatably attached to the arm of an excavator, which is a type of construction machine. In the following description, the left-right direction, the up-down direction, and the front-back direction are directions based on the perspective of the driver when the two-tooth plate 1 of the bucket 5 is facing the driver of the excavator. The front direction refers to the forward direction, and the back direction refers to the depth direction.

[0010] The two-tooth plate 1 includes a left-end tooth piece 10, a plurality of intermediate tooth pieces 20, 30, 40, and a right-end tooth piece 50. The five tooth pieces 10, 20, 30, 40, 50 are provided in a state of being arranged and connected in the left-right direction. The left-end tooth piece 10 is located at the left end of the tooth pieces 10, 20, 30, 40, 50, and the right-end tooth piece 50 is located at the right end of the tooth pieces 10, 20, 30, 40, 50.

[0011] (Left-end tooth piece 10) As shown in FIG. 2(a), the left-end tooth piece 10 includes an adapter connection portion 11, a tooth plate portion 12, and an upper overlapping plate portion 13. The tooth plate portion 12 is a portion that functions as a tooth and is formed in a rectangular plate shape along the left-right direction and the front-back direction. The tooth plate portion 12 includes a thick portion 12a located at the left corner of the tooth plate portion 12. The thick portion 12a forms an L shape along the left corner of the tooth plate portion 12 and is formed thicker than the thickness of the tooth plate portion 12 other than the thick portion 12a.

[0012] The upper overlapping plate portion 13 overlaps so as to be in surface contact with the upper surface of a lower overlapping plate portion 25 (see FIGS. 1(a) and 1(b)) of an adjacent intermediate two-tooth piece 20 described later. The upper overlapping plate portion 13 is formed in a rectangular plate shape that is long in the front-rear direction on the same plane as the two-tooth plate portion 12. The lower surface of the upper overlapping plate portion 13 is formed with a step upward from the lower surface of the two-tooth plate portion 12 by the thickness of the lower overlapping plate portion 25 of the adjacent intermediate two-tooth piece 20. The upper overlapping plate portion 13 includes a thick portion 13a located on the front side of the upper overlapping plate portion 13. The front end portion of the upper overlapping plate portion 13 is at the same position as the front end portion of the two-tooth plate portion 12, and the rear end portion of the upper overlapping plate portion 13 is located on the rear side of the rear end portion of the two-tooth plate portion 12.

[0013] As shown in FIGS. 2(a) and 4, the adapter connection portion 11 is installed on the upper surface of the two-tooth plate portion 12 (specifically, the rear side at the center in the left-right direction of this upper surface). The adapter connection portion 11 has a shape having a cavity into which the adapter 5a fits. Specifically, the adapter connection portion 11 includes side wall portions 11a, 11b and an upper wall portion 11c. The side wall portions 11a, 11b stand on the upper surface of the two-tooth plate portion 12 and face each other in the left-right direction via the adapter 5a. The side wall portions 11a, 11b form a triangular shape in which the height decreases as it progresses forward when viewed from the left-right direction. The upper wall portion 11c is formed so as to connect the upper ends of the side wall portions 11a, 11b and is inclined so as to approach the upper surface of the two-tooth plate portion 12 as it progresses forward.

[0014] A head operation hole 11d, which is a circular through-hole penetrating in the thickness direction of the side wall portion 11a, is formed in the side wall portion 11a. The head operation hole 11d is a hole where an operation head 71a (see FIG. 4) of a mounting pin unit 70 described later is located. The head operation hole 11d is located at the rear lower side of the side wall portion 11a. The head operation hole 11d is formed at a position exposed to the left outside.

[0015] On the outer surface of the side wall portion 11a (the surface opposite to the intermediate two-piece 20, that is, the left side surface), a first convex portion 11f is formed. The first convex portion 11f protrudes from the outer surface of the side wall portion 11a and is formed so as to surround the periphery of the head operation hole 11d. The first convex portion 11f has a function of protecting the operation head 71a and a function of emphasizing the position of the operation head 71a to make it conspicuous to users such as drivers. The first convex portion 11f is formed in a shape that is smaller than the entire outer surface of the side wall portion 11a in the vertical and longitudinal directions. The lower end portion of the first convex portion 11f is along the upper surface of the two-piece plate portion 12, and the rear end portion of the first convex portion 11f is along the rear end portion of the side wall portion 11a. The front end 11j of the first convex portion 11f is formed in a curved shape that bulges upward and forward.

[0016] As shown in FIGS. 4 and 5, in the side wall portion 11b, a non-circular through hole 11g that penetrates in the thickness direction of the side wall portion 11b is formed. The anti-rotation hole 11g is a hole where the anti-rotation head 73a of the mounting pin unit 70 is located. The center position of the anti-rotation hole 11g is at the same position as the center position of the head operation hole 11d when viewed from the left-right direction. The anti-rotation hole 11g has a substantially polygonal shape that is long in a direction orthogonal to the left-right direction when viewed from the left-right direction. In this example, it has a rectangular shape with rounded corners that is long in the front-rear direction. The longitudinal direction of the rectangular anti-rotation hole 11g is inclined with respect to the front-rear direction. Specifically, as it progresses toward the rear side, this longitudinal direction is inclined so as to be away from the upper overlapping plate portion 13. The longitudinal length of the anti-rotation hole 11g is formed to be smaller than the diameter of the head operation hole 11d. As shown in FIG. 1(a), the anti-rotation hole 11g faces the right direction of the adapter connection portion 21 of the adjacent intermediate two-piece 20.

[0017] On the outer surface of the side wall portion 11b (the surface on the intermediate two-piece 20 side, that is, the right side surface), a second convex portion 11i is formed. The second convex portion 11i protrudes from the outer surface of the side wall portion 11b and is formed so as to surround the periphery of the anti-rotation hole 11g. The second convex portion 11i has the same shape as the first convex portion 11f when viewed from the left-right direction. The second convex portion 11i increases the area of the inner peripheral surface of the anti-rotation hole 11g and functions as a mark for the position of the anti-rotation head 73a. The height (thickness in the left-right direction) of the second convex portion 11i is formed lower than the height of the first convex portion 11f. The height of the second convex portion 11i is set to 3 / 4 to 1 / 4, for example, about 1 / 2 of the height of the first convex portion 11f. A user such as a driver can recognize the position of the operation head 71a by comparing the heights of the first convex portion 11f and the second convex portion 11i and using the first convex portion 11f with the higher height as a mark.

[0018] As shown in FIG. 4, the thickness Tb of the side wall portion 11b is formed thicker than the thickness Ta of the side wall portion 11a. Here, when the operation head 71a is rotationally operated, the anti-rotation head 73a comes into contact with the inner peripheral surfaces of the anti-rotation hole 11g and the second convex portion 11i, so that the anti-rotation head 73a is in an anti-rotation state within the anti-rotation hole 11g. Therefore, by forming the thickness Tb of the side wall portion 11b thick, deformation of the left-end two-piece 10 and thus the two-piece board 1 due to this contact is suppressed.

[0019] (Right-end two-piece 50) As shown in FIGS. 1(a), (b) and 2(b), the right-end two-piece 50 includes an adapter connection portion 51, a two-piece board portion 52, a lower overlapping plate portion 55, and upper pressing portions 54a, 54b. The adapter connection portion 51 and the two-piece board portion 52 of the right-end two-piece 50 are formed symmetrically about a symmetry axis extending in the front-rear direction with respect to the adapter connection portion 11 and the two-piece board portion 12 of the above-described left-end two-piece 10. The side wall portion 51a of the adapter connection portion 51 includes a head operation hole 51d and a first convex portion 51f. The head operation hole 51d, the first convex portion 51f, and the operation head 71a within the head operation hole 51d are formed at positions exposed to the right outside as shown in FIG. 3. As shown in FIG. 1(b), the side wall portion 51b of the adapter connection portion 51 includes a rotation prevention hole 51g and a second convex portion 51i. The rotation prevention hole 51g and the second convex portion 51i are positioned so as to face the left direction of the adapter connection portion 41 of the intermediate two-piece 40.

[0020] The lower overlapping plate portion 55 contacts the lower surface of the upper overlapping plate portion 43 of the adjacent intermediate two-piece 40 over the entire front-rear direction. The lower overlapping plate portion 55 is formed in a rectangular plate shape that is long in the front-rear direction and is connected to the tooth plate portion 52 with a step. The upper surface of the lower overlapping plate portion 55 is formed to be recessed with respect to the upper surface of the tooth plate portion 52 by the thickness of the upper overlapping plate portion 43.

[0021] The upper pressing portions 54a and 54b are positioned so as to sandwich the upper overlapping plate portion 43 from above and below between them and the lower overlapping plate portion 55. The upper pressing portions 54a and 54b are positioned above the lower overlapping plate portion 55 at positions separated in the front-rear direction. The upper pressing portions 54a and 54b are formed in a rectangular plate shape, specifically, a rectangular plate shape that is long in the left-right direction. The upper pressing portion 54a is positioned in front of the rotation prevention hole 51g, and the upper pressing portion 54b is positioned behind the rotation prevention hole 51g.

[0022] (Intermediate two-pieces 20, 30, 40) As shown in FIGS. 1(a) and 1(b), the three intermediate two-pieces 20, 30, and 40 have the same shape as each other. Hereinafter, the intermediate two-piece 20 will be described, but the other intermediate two-pieces 30 and 40 have the same configuration. The intermediate two-piece 20 has the same configuration as the left-end two-piece 10 except that on the left side of the tooth plate portion 22, it has a lower overlapping plate portion 25 and upper pressing portions 24a and 24b that have the same configuration as the lower overlapping plate portion 55 and the upper pressing portions 54a and 54b described above. That is, the intermediate two-piece 20 includes an adapter connection portion 21, a tooth plate portion 22, an upper overlapping plate portion 23, a lower overlapping plate portion 25, and upper pressing portions 24a and 24b. Since these configurations are the same as the above-described configurations, the description is omitted.

[0023] Next, the connection modes of each two-piece 10, 20, 30, 40, 50 will be described. As shown in FIGS. 1(a) and 1(b), the upper overlapping plate portion 13 of the left end two-piece 10 is inserted between the lower overlapping plate portion 25 of the middle two-piece 20 and the upper pressing portions 24a and 24b. The upper overlapping plate portion 23 of the middle two-piece 20 is inserted between the lower overlapping plate portion of the middle two-piece 30 and the upper pressing portion. The upper overlapping plate portion of the middle two-piece 30 is inserted between the lower overlapping plate portion of the middle two-piece 40 and the upper pressing portion. The upper overlapping plate portion 43 of the left end two-piece 40 is inserted between the lower overlapping plate portion 55 of the right end two-piece 50 and the upper pressing portions 54a and 54b.

[0024] (Mounting pin unit 70) As shown in FIG. 3, each mounting pin unit 70 fixes each two-piece 10, 20, 30, 40, 50 to each adapter 5a to 5e so as not to fall off. Hereinafter, the mounting pin unit 70 for fixing the left end two-piece 10 will be described, but the mounting pin units 70 for fixing the other two-pieces 20, 30, 40, 50 are also configured in the same manner. As shown in FIG. 4, the mounting pin unit 70 includes an operation pin 71, a housing cylinder portion 72, and a fixing pin 73, which are separate parts. The operation pin 71 includes an operation head portion 71a and a screw shaft 71b. The housing cylinder portion 72 includes a head cylinder portion 72a that houses the operation head portion 71a from the outer periphery and a shaft housing cylinder portion 72b that houses the base end portion of the screw shaft 71b.

[0025] The operation head portion 71a is configured to be rotatable by a tool (not shown). The operation head portion 71a has a cylindrical shape and has a hole into which the tool fits on the end face opposite to the screw shaft 71b. The operation head portion 71a is rotatably housed in the head cylinder portion 72a. The head cylinder portion 72a is located in the head operation hole 11d and the first convex portion 11f.

[0026] The fixing pin 73 includes a cylindrical portion 73b having a screw hole into which the screw shaft 71b is screwed, and a rotation prevention head portion 73a located at the base end portion of the cylindrical portion 73b. The anti-rotation head 73a has a non-circular plate shape, and in this example, it has a rectangular plate shape with rounded corners. The anti-rotation head 73a is located within the anti-rotation hole 11g, and a gap SK is formed between the outer peripheral surface of the anti-rotation head 73a and the inner peripheral surface of the anti-rotation hole 11g. As shown in FIG. 5, when the center position of the anti-rotation head 73a is located at the center position of the anti-rotation hole 11g, the gap SK between the inner peripheral surface of the anti-rotation hole 11g and the outer peripheral surface of the anti-rotation head 73a is set to 0.5 mm to 3.0 mm, more preferably 1.0 mm to 3.0 mm.

[0027] (Mounting method of the two-piece) Next, a method for attaching the left-end two-piece 10 to the adapter 5a with the mounting pin unit 70 will be described. First, insert the adapter connection portion 11 of the left-end two-piece 10 into the adapter 5a. Then, insert the fixing pin 73 so that its anti-rotation head 73a is located within the anti-rotation hole 11g. Next, insert the housing cylinder portion 72 so that the head cylinder portion 72a is located within the head operation hole 11d, and bring the tips of the cylindrical portion 73b and the shaft housing cylinder portion 72b into contact with each other. Then, with the screw shaft 71b aligned with the screw hole of the cylindrical portion 73b, rotate the operation head 71a with a tool. As a result, the screw shaft 71b is screwed into the screw hole of the cylindrical portion 73b, and the operation head 71a is positioned within the head cylinder portion 72a and the head operation hole 11d. At this time, since the anti-rotation head 73a is in an anti-rotation state within the anti-rotation hole 11g, the fixing pin 73 is prevented from rotating along. In this way, the mounting pin unit 70 is integrated in a state of passing through the through-hole 5h of the adapter 5a, and the left-end two-piece 10 is held by the adapter 5a. Thus, the attachment work of the left-end two-piece 10 is completed. The other two-pieces 20, 30, 40, 50 can also be attached to the adapters 5b to 5e with the mounting pin unit 70 in the same manner. The attachment order of the two-piece is, for example, attached in the order of two-piece 10 → 20 → 30 → 40 → 50, and removed in the reverse order. Note that the attachment order of the two-piece is not limited to this order, and it may be attached in the order of two-piece 50 → 40 → 30 → 20 → 10 and removed in the reverse order. That is, the attachment or removal starts from the leftmost two-piece 10 or the rightmost two-piece 50.

[0028] (Effect) According to the above-described embodiment, the following effects can be obtained. (1) When the two-tooth plate 1 is attached to the adapters 5a to 5e of the bucket 5, the operation heads 71a are located on both outer sides in the left-right direction of the two-tooth plate 1. As a result, the operation head 71a on the tightening side is easily visible from the outside, and the user can be made to detect early the loosening or breakage of the operation head 71a of the mounting pin unit 70. Also, since the tightening forces from both end sides in the left-right direction of the two-tooth plate 1 act in the direction of bringing the two-pieces 10, 20, 30, 40, 50 closer, the two-tooth plate 1 can be attached to the adapters 5a to 5e in a more integrated state, and the excavation ability of the two-tooth plate 1 is enhanced. Furthermore, since both end portions (especially the left end portion) in the left-right direction of the two-tooth plate 1 serve as reference positions for first contacting the excavation object, which is the target, stress due to the reaction force from the excavation object is likely to occur. Therefore, it is particularly beneficial to detect early the loosening or breakage of the operation head 71a corresponding to the leftmost two-piece 10 and the rightmost two-piece 50.

[0029] (2) The upper overlapping plate portions of each of the two-piece units 10, 20, 30, 40 overlap so as to ride on the lower overlapping plate portions of each of the two-piece units 20, 30, 40, 50 located on the right side of these two-piece units 10, 20, 30, 40. The driver usually aligns the viewpoint with the left end portion of the two-piece board 1 and first contacts the excavation object, which is the target object, with this left end portion as the reference position. At this time, the left end portion of the two-piece board 1 receives the reaction force F1 (Fig. 3) from the excavation object, and the stress generated along with the reaction force F1 can be dispersed and received by all the two-piece units 10, 20, 30, 40, 50 according to the overlapping mode of the above-described upper overlapping plate portion and the lower overlapping plate portion. Therefore, the stress concentration on only the left end two-piece unit 10 is suppressed, and the breakage of the two-piece unit 10 is suppressed. Also, although the stress concentration is dispersed in this way, since a relatively large stress is likely to be applied to the left end two-piece unit 10 relatively frequently, as described in (1) above, it is particularly beneficial to detect early the loosening or breakage of the tightening of the operation head 71a corresponding to the left end two-piece unit 10.

[0030] (3) The gap SK between the inner peripheral surface of the anti-rotation holes 11g, 51g and the outer peripheral surface of the anti-rotation head 73a is set to 0.5 mm to 3.0 mm. If the gap SK is set to less than this numerical range, when the two-piece board 1 moves, there is a risk that force will be transmitted from the two-piece board 1 to the mounting pin unit 70, which may cause damage to the mounting pin unit 70 or the two-piece board 1. On the other hand, if the gap SK is set to a value exceeding this numerical range, there is a concern about the trouble that foreign matters such as stones and gravel will enter the gap SK. From the above viewpoints, it is preferable to set the above numerical range. In the above numerical range, it is possible to suppress the transmission of force from the two-piece board 1 to the mounting pin unit 70 and also suppress the trouble of foreign matter entry.

[0031] (4) The thickness Tb of the side wall portion 11b having the anti-rotation hole 11g is formed to be thicker than the thickness Ta of the side wall portion 11a having the head operation hole 11d. Thereby, even if foreign matter enters the gap SK between the inner peripheral surface of the anti-rotation holes 11g, 51g and the outer peripheral surface of the anti-rotation head 73a by any chance, it is suppressed that this leads to breakage or dropping accident of the two-tooth disc 1.

[0032] (5) A first convex portion 11f surrounding the periphery of the operation head 71a is formed on the outer surface of the side wall portion 11a. Thereby, wear, breakage or loosening of the operation head 71a due to contact with the excavated material can be suppressed. Also, the position of the operation head 71a can be easily confirmed even from a distance by the first convex portion 11f. Even if earth and sand enters the head operation hole 11d so as to hide the operation head 71a, the position of the operation head 71a can be confirmed by the first convex portion 11f.

[0033] (6) The convex amount of the first convex portion 11f serving as a mark of the operation head 71a is larger than the convex amount of the second convex portion 11i serving as a mark of the anti-rotation head 73a. For this reason, the positions of the operation head 71a and the anti-rotation head 73a can be easily confirmed even from a distance. In particular, when the thickness Ta of the side wall portion 11a is formed to be thinner than the thickness Tb of the side wall portion 11b, it is easy to form the convex amount of the first convex portion 11f to be larger than the convex amount of the second convex portion 11i. Also, since the head operation hole 11d formed in the side wall portion 11a and the anti-rotation hole 11g formed in the side wall portion 11b are formed with different sizes and shapes, the positions of the operation head 71a and the anti-rotation head 73a can be easily confirmed even from a distance.

[0034] As described above, the following configurations are disclosed in the above-described embodiment. (A) The two-tooth plate 1 is fixed to a plurality of adapters 5a to 5e of the bucket 5 by a mounting pin unit 70. The two-tooth plate 1 includes a plurality of two-tooth pieces 10, 20, 30, 40, 50 arranged in a state of being connected in the left-right direction, which is the direction in which the plurality of adapters 5a to 5e are arranged. The plurality of two-tooth pieces 10, 20, 30, 40, 50 each include adapter connection portions 11, 21, 31, 41, 51 into which the adapters 5a to 5e can be inserted. The adapter connection portions 11, 21, 31, 41, 51 include side wall portions 11a, 11b, 51a, 51b, which are examples of first and second side wall portions facing each other in the left-right direction via the adapters 5a to 5e. Head operation holes 11d, 51d in which operation heads 71a located at one axial end of the mounting pin unit 70 and rotated by a tool extending in the left-right direction through the adapters 5a to 5e are formed are formed in the side wall portions 11a, 51a. Anti-rotation holes 11g, 51g in which anti-rotation heads 73a located at the other axial end of the mounting pin unit 70 are located are formed in the side wall portions 11b, 51b. The head operation holes 11d, 51d of the left end two-tooth piece 10 and the right end two-tooth piece 50 located at both ends in the left-right direction among the plurality of two-tooth pieces 10, 20, 30, 40, 50 are located so as to be exposed to both left and right outer sides. According to this configuration, the effect of the above (1) can be achieved.

[0035] (B) First convex portions 11f, 51f that are convex on the outer surface of the side wall portion 11a are formed in a region surrounding the periphery of the operation head 71a on the side wall portions 11a, 51a. According to this configuration, the effect of the above (5) can be achieved.

[0036] (C) Second convex portions 11i, 51i that are convex on the outer surfaces of the side wall portions 11b, 51b are formed in a region surrounding the periphery of the anti-rotation head 73a on the side wall portions 11b, 51b. The height of the first convex portions 11f, 51f with respect to the outer surfaces of the side wall portions 11a, 51a is formed higher than the height of the second convex portions 11i, 51i with respect to the outer surfaces of the side wall portions 11b, 51b. According to this configuration, the effect of the above (6) can be achieved.

[0037] (D) The thickness Tb of the side wall portions 11b and 51b is formed thicker than the thickness Ta of the side wall portions 11a and 51a. According to this configuration, the effect of (4) above can be achieved.

[0038] (E) Among the plurality of two-piece units 10, 20, 30, 40, 50, the two-piece units 10, 20, 30, 40 other than the rightmost two-piece unit 50 are provided with upper overlapping plate portions 13, 23, 43 formed in a plate shape in their respective right regions. Among the plurality of two-piece units 10, 20, 30, 40, 50, the two-piece units 20, 30, 40, 50 other than the leftmost two-piece unit 10 are formed in a plate shape in their respective left regions and are provided with lower overlapping plate portions 25, 55 that contact the lower surfaces of the upper overlapping plate portions 13, 23, 43 of adjacent two-piece units. According to this configuration, the effect of (2) above can be achieved.

[0039] (F) The anti-rotation head 73a has a shape that is long in a predetermined one direction (the front-rear direction in this example) orthogonal to the axial direction of the mounting pin unit 70, and is configured to be non-rotatable by contacting the inner peripheral surface of the anti-rotation holes 11g, 51g during the rotation operation of the operation head 71a. The gap SK between the inner peripheral surface of the anti-rotation holes 11g, 51g and the outer peripheral surface of the anti-rotation head 73a when the center position of the anti-rotation head 73a is located at the center position of the anti-rotation holes 11g, 51g is set to 0.5 mm to 3.0 mm. According to this configuration, the effect of (3) above can be achieved.

[0040] Note that the present invention is not limited to the above embodiments and drawings. Modifications (including deletion of components) can be appropriately made without changing the gist of the present invention.

[0041] (Modification example) The shapes of the anti-rotation head 73a and the anti-rotation holes 11g are not limited to the above embodiments and may be other polygonal shapes or elliptical shapes. At least one of the first convex portions 11f, 51f and the second convex portions 11i, 51i of the two-piece units 10, 20, 30, 40, 50 may be omitted. In the above embodiment, the orientation of the mounting pin unit 70 attached to the intermediate two-piece pieces 20, 30, 40 can be appropriately changed. The shapes of the first convex portions 11f, 51f and the second convex portions 11i, 51i as viewed from the left-right direction may be different from each other. Also, the heights of the first convex portions 11f, 51f and the second convex portions 11i, 51i may be the same. In the above embodiment, the first convex portions 11f, 51f and the second convex portions 11i, 51i may be formed so as to surround only the front side portion without surrounding the entire circumferences of the head operation holes 11d, 51d and the anti-rotation holes 11g, 51g. In the above embodiment, the thickness Tb and the thickness Ta may be the same thickness, or the thickness Ta may be formed thicker than the thickness Tb. In the above embodiment, the gap SK may be set to a value other than 0.5 mm to 3.0 mm. The number of the intermediate two-piece pieces 20, 30, 40 in the above embodiment may be two, or may be four or more. In the above embodiment, the overlapping modes of the upper overlapping plate portions and the lower overlapping plate portions of each of the two-piece pieces 10, 20, 30, 40, 50 can be appropriately changed. The mounting pin unit 70 is not limited to the structure of the above embodiment as long as the operation head 71a located at one end in the axial direction thereof is rotationally operated to tighten the anti-rotation head 73a located at the other end in the axial direction and in a non-rotating state. For example, it may be a mounting pin unit having a structure disclosed in Japanese Patent Application Laid-Open No. 2011-246974.

Explanation of Reference Numerals

[0042] 1... two-spindle board, 5... bucket, 5a~5e... adapter, 5h... through hole, 10... left-end two-spindle piece, 20, 30, 40... intermediate two-spindle pieces, 50... right-end two-spindle piece, 11, 21, 31, 41, 51... adapter connection part, 11a, 11b, 51a, 51b... side wall parts, 11c... upper wall part, 11d, 51d... head operation holes, 11f, 51f... first convex part, 11g, 51g... anti-rotation holes, 11i, 51i... second convex part, 11j... front end, 12, 52... two-spindle plate parts, 12a, 13a... thick parts, 13, 23, 43... upper overlapping plate parts, 25, 55... lower overlapping plate parts, 70... mounting pin unit, 71... operation pin, 71a... operation head, 71b... screw shaft, 72... housing cylinder part, 72a... head cylinder part, 72b... shaft housing cylinder part, 73... fixing pin, 73a... anti-rotation head, 73b... cylindrical part, F1... reaction force, SK... gap

Claims

1. A teeth disk fixed to a plurality of adapters of a bucket by a mounting pin unit, The tooth pieces are connected and arranged in a left-right direction, which is a direction in which the adapters are arranged, Each of the plurality of tooth pieces includes an adapter connection portion into which the adapter can be inserted, the adapter connection portion includes first and second sidewall portions that face each other in the left-right direction with the adapter interposed therebetween, A head operation hole is formed in the first side wall portion, in which an operation head is located that is rotated by a tool provided at one end of the mounting pin unit in the axial direction, the mounting pin unit extending through the adapter in the left-right direction, The second side wall portion is formed with a rotation prevention hole in which a rotation prevention head portion provided at the other axial end of the mounting pin unit is positioned, The head operation holes of the left end tooth piece and the right end tooth piece located at both ends in the left-right direction among the plurality of tooth pieces are positioned so as to be exposed to both left and right outer sides. Tooth board.

2. The first side wall portion has a first convex portion formed in a region surrounding the periphery of the operation head portion and having a convex shape on an outer surface of the first side wall portion. The tooth disc according to claim 1.

3. The second side wall portion has a second protrusion formed in a region surrounding the anti-rotation head portion and protruding from an outer surface of the second side wall portion, A height of the first protrusion with respect to an outer surface of the first side wall portion is greater than a height of the second protrusion with respect to an outer surface of the second side wall portion. A tooth disc as claimed in claim 2.

4. The second side wall portion is formed to have a thickness greater than a thickness of the first side wall portion. A tooth disc as claimed in any one of claims 1 to 3.

5. Among the plurality of tooth pieces, each tooth piece except the right end tooth piece includes an upper overlapping plate portion formed in a plate shape in a right side region thereof, Among the plurality of tooth pieces, each tooth piece other than the left end tooth piece is provided with a lower overlapping plate portion formed in a plate shape in a left side region thereof and contacting a lower surface of the upper overlapping plate portion of the adjacent tooth piece. A tooth disc as claimed in any one of claims 1 to 3.

6. the anti-rotation head has a shape that is elongated in one direction perpendicular to the axial direction of the mounting pin unit, and is configured to be non-rotatable by contacting an inner circumferential surface of the anti-rotation hole during a rotation operation of the operating head, When the center position of the anti-rotation head is located at the center position of the anti-rotation hole, a gap between the inner peripheral surface of the anti-rotation hole and the outer peripheral surface of the anti-rotation head is set to 0.5 mm to 3.0 mm. A tooth disc as claimed in any one of claims 1 to 3.

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