JP2023143020A - clamshell bucket - Google Patents

Abstract

To provide a clamshell bucket which facilitates the repair of an abutting member.SOLUTION: A clamshell bucket 11 has: a pair of buckets 17, 21 rotatably supported on a base member 12 via support pins 20, 24 and displacing between an open position and a closed position; a base side abutting member 27 provided in the base member 12; and bucket side abutting members 32, 36 provided in the pair of buckets 17, 21, respectively. The base side abutting member 27 is composed of: a base side fixing member 28 fixed to the base member 12; and base side exchange members 29, 30 exchangeably fitted to the base side fixing member 28. The bucket side abutting members 32, 36 are composed of: bucket side fixing members 33, 37 fixed to the buckets 17, 21; and bucket side exchange members 34, 38 exchangeably fitted to the bucket side fixing members 33, 37 and abutting on the base side exchange members 29, 30.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a clamshell bucket installed in a construction machine that excavates a shaft.

Generally, when excavating a shaft deep underground, a shaft excavator is preferably used. The shaft excavator includes a self-propelled lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, and a working device provided on the front side of the upper rotating body. The working device includes, for example, a multistage telescopic arm that can be extended and retracted in the vertical direction, and a clamshell bucket provided at the tip of the arm.

A clamshell bucket includes a base member attached to the tip side of an arm, and a pair of parts that are rotatably supported by the base member via a support pin and are displaced between an open position where they are separated from each other and a closed position where they are close to each other. Comes with a bucket. The clamshell buckets are lowered to the bottom of the shaft with the pair of buckets in the open position, and then moved to the closed position to excavate earth and sand. Then, the clamshell bucket rises from the shaft to the ground with the pair of buckets in the closed position, and moves the pair of buckets to the open position above the dump truck, etc. to remove excavated materials such as earth and sand. It is discharged onto the bed of a dump truck (Patent Document 1).

JP 2019-120087 Publication

Here, the clamshell bucket according to the prior art includes a hydraulic cylinder for opening and closing the pair of buckets, and displaces the pair of buckets between a closed position and an open position according to the operation of the hydraulic cylinder. For this reason, the base member and the pair of buckets that make up the clamshell bucket are usually provided with an abutting member to set the amount of displacement (maximum opening degree) when the bucket is displaced from the closed position to the open position. It is being This contact member is provided on the base member and the pair of buckets, and when the pair of buckets is opened to the maximum, they collide with each other and set the maximum opening, thereby preventing the hydraulic cylinder from exceeding the appropriate range. Regulate operation. This prevents excessive load from being applied to the hydraulic cylinder, and also makes it possible to discharge excavated materials such as earth and sand remaining in the pair of buckets by utilizing the impact when the contact members collide with each other. .

Incidentally, as the clamshell bucket opens and closes, the abutting members on the base member side and the abutting members on the pair of buckets repeatedly collide with each other, causing wear and deformation of these abutting members. Therefore, the maximum opening degree of the pair of buckets increases, and in order to prevent the hydraulic cylinder from operating beyond an appropriate range, the abutment member needs to be repaired depending on the degree of wear.

To repair a worn or deformed abutment member, generally, metal is added (overlayed) using means such as welding, and then formed by machining. However, when repairing such abutment members, the abutment member on the side of one of the buckets, the abutment member on the base member side, and the abutment member on the side of the other bucket of the pair of buckets. It is necessary to mold each abutting member so that the abutting member on the base member side and the abutting member on the base member side evenly abut each other when the pair of buckets are in the open position. For this reason, there is a problem in that repairing the abutment member requires a large number of man-hours and also requires a skilled repair technique.

An object of the present invention is to provide a clamshell bucket whose abutting member can be easily repaired.

The present invention includes a base member attached to the distal end side of an arm constituting a working device, and a base member rotatably supported by the base member via a support pin, and between an open position where they are separated from each other and a closed position where they are close to each other. a pair of buckets that are displaced at the same time, a base-side abutting member provided on the base member, and a base-side abutment member provided on each of the pair of buckets when the pair of buckets is displaced to the open position; a bucket-side abutting member that abuts on the clamshell bucket, wherein the base-side abutting member is replaceably attached to a base-side fixing member fixed to the base member and the base-side fixing member. the bucket-side contact member is configured to include a bucket-side fixing member fixed to the pair of buckets, and a base-side replacement member that is replaceably attached to the bucket-side fixing member; and a bucket-side exchange member that comes into contact with the bucket side.

According to the present invention, even if the base-side replacement member and the bucket-side replacement member repeatedly collide with each other due to the opening/closing operation of the pair of buckets and are worn out or deformed, the base-side replacement member can be easily attached to the base-side fixing member. or the bucket-side replacement member can be easily replaced with respect to the bucket-side fixing member.

FIG. 1 is a left side view showing a shaft excavator equipped with a clamshell bucket according to an embodiment of the present invention. It is a perspective view showing a clamshell bucket. FIG. 3 is a left side view showing the clamshell bucket in a closed position. FIG. 4 is a cross-sectional view of the clamshell bucket viewed from the direction of arrow IV-IV in FIG. 3. FIG. 3 is an enlarged view of main parts showing a base-side contact member and a bucket-side contact member. FIG. 3 is a perspective view showing a base-side fixing member and a base-side replacement member. FIG. 3 is a left side view showing the clamshell bucket in an open position. FIG. 8 is a cross-sectional view of a state in which the base-side contact member and the bucket-side contact member collide, as viewed from the direction of arrow VIII-VIII in FIG. 7; FIG. 9 is a sectional view similar to FIG. 8 showing a base-side abutting member and a bucket-side abutting member according to a modified example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A clamshell bucket according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings, taking as an example the case where it is mounted on a shaft excavator.

In the figure, a shaft excavator 1 includes a self-propelled crawler-type lower traveling body 2 and an upper revolving body 3 rotatably mounted on the lower traveling body 2. The lower traveling body 2 and the upper revolving body 3 constitute the body of the shaft excavator 1. A working device 4 is provided on the front side of the upper revolving body 3, and can be used to excavate a shaft deep underground.

The upper revolving body 3 includes a revolving frame 5 serving as a base, a counterweight 6 provided at the rear end of the revolving frame 5, and a cab 7 provided at the front left portion of the revolving frame 5. The counterweight 6 maintains a weight balance with the working device 4 provided on the front side of the revolving upper structure 3. The cab 7 defines a driver's cabin in which an operator rides, and inside the cab 7, a driver's seat, operating levers for work, operating levers/pedals for traveling, etc. (none of which are shown) are arranged. ing.

The working device 4 is provided on the front side of the upper revolving body 3 and excavates a shaft P deep underground. The working device 4 includes a boom 8 attached to the front end side of the revolving frame 5 so as to be rotatable in the vertical direction, and a multistage telescopic arm 9 rotatably attached to the tip of the boom 8. It is configured to include a clamshell bucket 11, which will be described later, which is rotatably attached to the tip of the arm 9. The arm 9 includes an outer cylinder 9A attached to the tip of the boom 8, a first inner cylinder 9B extendably provided inside the outer cylinder 9A, and an extendably provided inside the first inner cylinder 9B. A clamshell bucket 11 is attached to the tip of the second inner cylinder 9C.

Next, the clamshell bucket 11 according to this embodiment will be described with reference to FIGS. 2 to 8.

The clamshell bucket 11 is attached to the tip of the arm 9 (second inner cylinder 9C) that constitutes the working device 4. The clamshell bucket 11 includes a base member 12, a hydraulic cylinder 13, and a pair of buckets 17, 21. The clamshell bucket 11 excavates earth and sand by opening and closing the pair of buckets 17, 21 with the hydraulic cylinder 13. Excavate a vertical shaft P deep inside. For convenience of explanation, the direction in which the pair of buckets 17 and 21 open and close will be referred to as the opening and closing direction of the clamshell bucket 11, and the directions other than the vertical direction orthogonal to this opening and closing direction will be referred to as the width direction of the clamshell bucket 11.

The base member 12 is attached to the tip of the arm 9 (second inner cylinder 9C). The base member 12 is a member serving as the core (foundation) of the clamshell bucket 11, and includes a rod portion 12A extending in the vertical direction and a cross beam portion 12B provided at the lower end of the rod portion 12A. The cross beam portion 12B extends horizontally in the width direction orthogonal to the axial direction (vertical direction) of the rod portion 12A. As a result, the base member 12 is formed into an inverted T-shape as a whole.

The rod portion 12A of the base member 12 is made of a cylindrical body extending in the vertical direction, and also serves as a rod of a hydraulic cylinder 13, which will be described later. An arm attachment portion 12C is provided at the upper end of the rod portion 12A, and the arm attachment portion 12C is rotatably attached to the tip of the second inner cylinder 9C that constitutes the arm 9 via a support shaft.

The horizontal beam portion 12B of the base member 12 is formed of a rectangular cylinder extending in the width direction. The widthwise central portion of the cross beam portion 12B is fixed to the lower end of the rod portion 12A. Bucket mounting plates 12D extending in the opening/closing direction are provided at both ends of the cross beam portion 12B in the width direction, and a pair of buckets 17 and 21 are rotatable (opening/closing) at both ends of the bucket mounting plate 12D in the opening/closing direction. (possible).

The hydraulic cylinder 13 includes a rod portion 12A of the base member 12. That is, the hydraulic cylinder 13 includes a rod portion 12A of the base member 12, a piston (not shown) provided at an axially intermediate portion of the rod portion 12A, and a piston (not shown) provided on the outer peripheral side of the rod portion 12A surrounding the piston. It is formed by a double rod type hydraulic cylinder equipped with a tube 13A and a tube 13A. The tube 13A is attached to the rod portion 12A so as to be movable in the axial direction (vertical direction), and inside the tube 13A are an upper oil chamber located above the piston and a lower oil chamber located below the piston. is formed.

The tube 13A of the hydraulic cylinder 13 moves downward along the rod portion 12A when pressure oil is supplied to the upper oil chamber (see FIG. 3), and moves downward along the rod portion 12A when pressure oil is supplied to the lower oil chamber. (see Figure 7). A pair of link mounting brackets 13B that protrude radially outward from the tube 13A are attached to an axially intermediate portion of the tube 13A. One end of a link 14, which will be described later, is attached to each of these link attachment brackets 13B.

A pair of links 14 are provided between the tube 13A of the hydraulic cylinder 13 and the buckets 17 and 21, respectively. As shown in FIG. 2, the link 14 is formed in a triangular shape, with a narrow width on the tube 13A side (upper side) and a wider width on the bucket 17, 21 side (lower side) in the width direction. One end (upper end) 14A of the pair of links 14 is rotatably connected to a link mounting bracket 13B of the hydraulic cylinder 13 using an upper connecting pin 15. The other end (lower end) 14B of the pair of links 14 is rotatably connected to link connecting portions 18D and 22D of the buckets 17 and 21, which will be described later, using a lower connecting pin 16.

The pair of buckets 17 and 21 are rotatably attached to the base member 12 via support pins 20 and 24, which will be described later. The buckets 17 and 21 are arranged symmetrically in the opening/closing direction across the cross beam portion 12B of the base member 12, and have an open position where they are separated from each other (the position shown in FIG. 7) and a closed position where they are close to each other (the position shown in FIG. 3). ). The pair of buckets 17, 21 have openings 17A, 21A located on the bottom side of the shaft P, respectively, and scoop up dirt, etc. from the openings 17A, 21A by being displaced from the open position to the closed position. . Here, since the pair of buckets 17 and 21 have the same shape and configuration, one bucket 17 will be explained in detail, and the explanation about the other bucket 21 will be simplified.

The bucket 17 is rotatably supported by a pair of bucket mounting plates 12D provided at both widthwise ends of the cross beam portion 12B constituting the base member 12 using support pins 20, respectively. As shown in FIGS. 3 and 4, the bucket 17 includes a pair of side plates 18 that face each other with a gap in the width direction, and a bottom plate 19 that connects the pair of side plates 18. The space surrounded by is the earth and sand storage space S1 (see Fig. 4).

The side plate 18 of the bucket 17 includes a thick U-shaped thick plate portion 18A forming an outer frame portion of the side plate 18, and a thin thin plate portion 18B fixed to the thick plate portion 18A using means such as welding. It has The thick plate portion 18A reinforces a portion of the side plate 18 where stress is concentrated during excavation work using the bucket 17. The thick plate portion 18A is provided with a base member connecting portion 18C corresponding to the bucket attachment plate 12D of the base member 12 and a link connecting portion 18D corresponding to the other end 14B of the link 14. The base member connecting portion 18C of the side plate 18 is rotatably connected to the bucket attachment plate 12D of the base member 12 (cross beam portion 12B) using a support pin 20. Further, the link connecting portion 18D of the side plate 18 is rotatably connected to the other end 14B of the link 14 using a lower connecting pin 16.

A bottom plate 19 of the bucket 17 connects a pair of side plates 18. The bottom plate 19 is formed of a gently curved plate, and both widthwise ends of the bottom plate 19 are fixed to the pair of side plates 18 using means such as welding. A cutting edge 19A made of a thick plate is fixed to the edge of the bottom plate 19 located on the side of the opening 17A of the bucket 17 over the entire width direction. A plurality of (for example, three) digging claws 19B are attached to the cutting edge 19A at intervals in the width direction.

Like the bucket 17, the bucket 21 is composed of a pair of side plates 22 and a bottom plate 23 that connects the pair of side plates 22, and a space surrounded by the pair of side plates 22 and the bottom plate 23 is a sediment storage space S2. (See Figure 4).

The side plate 22 of the bucket 21 has a thick plate portion 22A and a thin plate portion 22B, and the thick plate portion 22A is provided with a base member connecting portion 22C and a link connecting portion 22D. The base member connecting portion 22C is rotatably connected to the bucket mounting plate 12D of the base member 12 using a support pin 24, and the link connecting portion 22D is connected to the other end 14B of the link 14 using a lower connecting pin 16. Rotatably connected. The bottom plate 23 of the bucket 21 connects the pair of side plates 22, and a cutting edge 23A is fixed to the edge of the bottom plate 23 located on the opening 21A side of the bucket 21. A plurality of digging claws 23B are attached to the cutting edge 23A at intervals in the width direction.

Therefore, when the tube 13A of the hydraulic cylinder 13 moves in the vertical direction along the rod portion 12A, the movement of the tube 13A is transmitted to the buckets 17 and 21 via the link 14. As a result, the bucket 17 rotates around the support pin 20, and the bucket 21 rotates around the support pin 24, so that the clamshell bucket 11 can be moved between the closed position shown in FIG. 3 and the open position shown in FIG. Displaced between.

The pair of earth removal devices 25 and 26 are provided on the horizontal beam portion 12B of the base member 12, respectively. One earth removal device 25 is arranged in the earth and sand storage space S1 of the bucket 17, and the other earth removal device 26 is arranged in the earth and sand storage space S2 of the bucket 21.

As shown in FIG. 4, the earth removal device 25 includes a pair of attachment members 25A fixed to the horizontal beam portion 12B of the base member 12, and a pair of attachment members 25A that are attached to the pair of attachment members 25A and extend toward the bottom plate 19 side of the bucket 17. It is formed into a frame shape by an L-shaped plate 25B and a scraping plate 25C that is fixed to the tips of the pair of L-shaped plates 25B and extends in the width direction between the pair of side plates 18 of the bucket 17. The scraping plate 25C is fixed at a position close to the inner surface of the bottom plate 19. Thereby, when the bucket 17 rotates (moves) from the closed position to the open position, the earth removal device 25 scrapes off earth and sand such as clay and mud stuck to the inner surface of the bottom plate 19 using the scraping plate 25C. be able to.

Similar to the earth removal device 25, the earth removal device 26 is also formed into a frame shape by a pair of mounting members 26A, a pair of L-shaped plates 26B, and a scraping plate 26C, and the scraping plate 26C is a bottom plate forming the bucket 21. It is fixed at a position close to the inner surface of 23. Thereby, when the bucket 21 rotates from the closed position to the open position, the earth removal device 26 can scrape off earth and sand such as clay and mud stuck to the inner surface of the bottom plate 23 using the scraping plate 26C. .

Next, the base side abutting member 27 and the bucket side abutting members 32 and 36 used in this embodiment will be explained.

The base-side contact members 27 are provided one each (two in total) at both ends in the width direction of the cross beam portion 12B that constitutes the base member 12 (see FIG. 4). When the clamshell bucket 11 is displaced from the closed position to the open position by the hydraulic cylinder 13, the bucket side contact members 32 and 36 provided on the buckets 17 and 21 come into contact with the base side contact member 27. This sets the open position (maximum opening degree) of the clamshell bucket 11, and prevents the tube 13A of the hydraulic cylinder 13 from moving beyond an appropriate range.

As shown in FIGS. 6 and 8, the base side abutting member 27 is replaceable with a base side fixing member 28 fixed to the cross beam portion 12B of the base member 12 using bolts 31 on the base side fixing member 28 ( The base side exchange members 29 and 30 are detachably attached to the base side exchange members 29 and 30.

The base side fixing member 28 has a rectangular parallelepiped block shape and is fixed to the upper surface of the cross beam portion 12B by means such as welding. A plurality (for example, four) of bolt holes (female threaded holes) 28C are formed in one side 28A of the base-side fixing member 28 located on the bucket 17 side and the other side 28B located on the bucket 21 side, respectively. . Moreover, notch grooves 28D as concave fitting portions are formed on one side 28A and the other side 28B of the base-side fixing member 28, respectively. The notch groove 28D is formed by cutting the center portion of the one side surface 28A and the other side surface 28B of the base side fixing member 28 in the width direction in a straight line in the vertical direction over the entire area from the top surface to the bottom surface of the base side fixing member 28. It is formed by

The base-side replacement member 29 is replaceably attached to one side 28A of the base-side fixing member 28 using four bolts 31, and the base-side replacement member 30 is attached to the other side 28B of the base-side fixing member 28 using four bolts 31. It is attached replaceably using a bolt 31.

The base-side replacement member 29 is formed of a thick plate having a rectangular shape that is equal to one side surface 28A of the base-side fixing member 28. The base-side replacement member 29 has four bolt insertion holes 29A that correspond to the bolt holes 28C formed in the one side surface 28A of the base-side fixing member 28. A counterbore hole 29B for accommodating the head of 31 is formed concentrically. Further, a fitting protrusion 29C as a convex fitting portion is provided on a surface of the base side replacement member 29 that comes into contact with one side surface 28A of the base side fixing member 28. The fitting protrusion 29C is formed by a linear protrusion extending vertically in the center of the base side replacement member 29 in the width direction, and fits into the notch groove 28D of the base side fixing member 28.

Then, by fitting the fitting protrusion 29C of the base side replacement member 29 into the notch groove 28D of the base side fixing member 28, the bolt hole 28C of the base side fixing member 28 and the bolt insertion hole 29A of the base side replacement member 29 are connected. and can be aligned. In this state, by inserting the bolt 31 into the bolt insertion hole 29A of the base-side replacement member 29 and screwing this bolt 31 into the bolt hole 28C of the base-side fixing member 28, one side 28A of the base-side fixing member 28 is inserted. The base side replacement member 29 can be attached to the base side replacement member 29.

In this case, as shown in FIG. 4, the gap A formed between the notch groove 28D and the fitting protrusion 29C is the diameter of the gap A formed between the bolt insertion hole 29A of the base side replacement member 29 and the bolt 31. It is set smaller than the gap B in the direction (A<B). As a result, even if a large load is applied to the base-side replacement member 29 due to a collision of the bucket-side replacement member 34 (described later), this load is transferred to the fitting portion between the notch groove 28D and the fitting protrusion 29C before the bolt 31. damage to the bolt 31 can be prevented.

On the other hand, the base-side replacement member 30 has the same shape and structure as the base-side replacement member 29. That is, the base-side replacement member 30 is formed with four bolt insertion holes 30A and counterbore holes 30B corresponding to the bolt holes 28C provided on the other side surface 28B of the base-side fixing member 28. Further, the base-side replacement member 30 is formed with a fitting protrusion 30C as a convex fitting portion that fits into a notch groove 28D provided on the other side surface 28B of the base-side fixing member 28.

The gap formed between the notch groove 28D and the fitting protrusion 30C is set smaller than the gap formed between the bolt insertion hole 30A of the base side replacement member 30 and the bolt 31. Then, with the fitting protrusion 30C of the base side replacement member 30 fitted into the notch groove 28D of the base side fixing member 28, the bolt 31 inserted into the bolt insertion hole 30A of the base side replacement member 30 is inserted into the base side Screw into the bolt hole 28C of the fixing member 28. Thereby, the base-side replacement member 30 can be attached to the other side surface 28B of the base-side fixing member 28.

One bucket-side contact member 32 is provided on each of the pair of side plates 18 that constitute the bucket 17 (two in total). The bucket-side contact member 32 sets the open position (maximum opening degree) of the bucket 17 by colliding with the base-side contact member 27 when the bucket 17 moves to the open position. The bucket-side contact member 32 includes a bucket-side fixing member 33 fixed to a pair of side plates 18 constituting the bucket 17, and a bucket that is replaceably (removably) attached to the bucket-side fixing member 33 using a bolt 35. and a side exchange member 34.

The bucket side fixing member 33 is formed of a thick rectangular plate, and is fixed to a position of the thick plate portion 18A of the side plate 18 close to the base member connecting portion 18C using means such as welding. . A plurality of (for example, four) bolt holes (femally threaded holes) 33B are formed on one side surface 33A of the bucket-side fixing member 33 facing the base-side contact member 27, and a notched groove as a concave fitting portion. 33C is formed. The cutout groove 33C is formed by cutting the widthwise central portion of the bucket-side fixing member 33 vertically linearly over the entire area from the top surface to the bottom surface of the bucket-side fixing member 33.

The bucket-side replacement member 34 is formed of a plate having the same square shape as the bucket-side fixing member 33. The bucket side replacement member 34 has four bolt insertion holes 34A corresponding to the bolt holes 33B formed in one side surface 33A of the bucket side fixing member 33, and a counterbore hole 34B for accommodating the head of the bolt 35. formed concentrically. Furthermore, a fitting protrusion 34C as a convex fitting portion is provided on a surface of the bucket-side replacement member 34 that comes into contact with one side surface 33A of the bucket-side fixing member 33. The fitting protrusion 34C is formed by a linear protrusion extending vertically in the widthwise center of the bucket-side replacement member 34, and fits into the notch groove 33C of the bucket-side fixing member 33.

In this case, the gap formed between the notch groove 33C and the fitting protrusion 34C is set smaller than the gap formed between the bolt insertion hole 34A of the bucket-side replacement member 34 and the bolt 35. Then, with the fitting protrusion 34C of the bucket side replacement member 34 fitted into the notch groove 33C of the bucket side fixing member 33, the bolt 35 inserted into the bolt insertion hole 34A of the bucket side replacement member 34 is inserted into the bucket side. It is screwed into the bolt hole 33B of the fixing member 33. Thereby, the bucket-side replacement member 34 can be replaceably attached to the one side surface 33A of the bucket-side fixing member 33.

One bucket-side contact member 36 is provided on each of the pair of side plates 22 that constitute the bucket 21 (two in total). The bucket-side contact member 36 sets the open position (maximum opening degree) of the bucket 21 by colliding with the base-side contact member 27 when the bucket 21 moves to the open position. The bucket-side contact member 36 includes a bucket-side fixing member 37 fixed to the pair of side plates 22 constituting the bucket 21, and a bucket-side replacement member 38 replaceably attached to the bucket-side fixing member 37 using bolts 35. It is composed of.

The bucket side fixing member 37 is formed of a thick rectangular plate, and is fixed to a position of the thick plate portion 22A of the side plate 22 close to the base member connecting portion 22C using means such as welding. . A plurality of bolt holes 37B are formed in one side surface 37A of the bucket-side fixing member 37 facing the base-side contact member 27, and a notch groove 37C as a concave fitting portion is formed.

The bucket-side replacement member 38 is formed of a plate having the same square shape as the bucket-side fixing member 37. The bucket side replacement member 38 has four bolt insertion holes 38A corresponding to the bolt holes 37B formed in one side surface 37A of the bucket side fixing member 37, and a counterbore hole 38B for accommodating the head of the bolt 35. formed concentrically. Further, a fitting projection 38C as a convex fitting portion is provided on a surface of the bucket side replacement member 38 that comes into contact with one side 37A of the bucket side fixing member 37. 37 into the notch groove 37C.

In this case, the gap formed between the notch groove 37C and the fitting protrusion 38C is set smaller than the gap formed between the bolt 35 and the bolt insertion hole 38A of the bucket side replacement member 38. Then, with the fitting protrusion 38C of the bucket side replacement member 38 fitted into the notch groove 37C of the bucket side fixing member 37, the bolt 35 inserted into the bolt insertion hole 38A of the bucket side replacement member 38 is inserted into the bucket side It is screwed into the bolt hole 37B of the fixing member 37. Thereby, the bucket-side replacement member 38 can be replaceably attached to the one side surface 37A of the bucket-side fixing member 37.

During the excavation work of the shaft P using the clamshell bucket 11, the bucket side replacement member 34 of the bucket side contact member 32 performs the base side replacement of the base side contact member 27 as the buckets 17 and 21 open and close. The bucket-side replacement member 38 of the bucket-side contact member 36 collides with the base-side replacement member 30 of the base-side contact member 27 . In this way, the bucket-side replacement members 34, 38 and the base-side replacement members 29, 30 gradually wear out, deform, etc. due to the impact caused by repeated collisions.

In contrast, in the present embodiment, the base-side replacement members 29 and 30 can be easily replaced with the base-side fixing member 28 fixed to the base member 12 using the bolts 31. Furthermore, the bucket-side replacement member 34 can be easily replaced with the bolt 35 for the bucket-side fixing member 33 fixed to the bucket 17, and the bucket-side fixing member 37 fixed to the bucket 21 can be easily replaced with the bolt 35. 35, the bucket side replacement member 38 can be easily replaced.

Here, if the bucket-side replacement members 34, 38 and the base-side replacement members 29, 30 are made of the same material, each will wear out, deform, etc. equally, and the bucket-side replacement members 34, 38 and the base-side replacement members 29, 30 will be replaced. It becomes necessary to frequently replace the members 34, 38 and the base side replacement members 29, 30.

In contrast, in the present embodiment, the base side replacement members 29 and 30 that constitute the base side contact member 27, the bucket side replacement member 34 that constitutes the bucket side contact member 32, and the bucket side contact member 36 are The constituent bucket-side exchange member 38 is formed using a material having a different hardness. Specifically, the base side replacement members 29 and 30 are formed using, for example, general structural rolled steel, and the bucket side replacement members 34 and 38 are made of a material having higher hardness and wear resistance than general structural rolled steel. Constructed using superior wear-resistant steel.

As a result, the base-side replacement members 29 and 30 that mainly constitute the base-side contact member 27 are worn out, so the bucket-side replacement member 34 of the bucket-side contact member 32 and the bucket-side replacement member of the bucket-side contact member 36 are worn out. 38 can be saved, and the workability of the replacement work can be improved. The reason for increasing the hardness of the material of the bucket-side replacement members 34 and 38 is as follows. That is, the bucket-side fixing member 33 to which the bucket-side exchange member 34 is attached and the bucket-side fixing member 37 to which the bucket-side exchange member 38 is attached are both formed of rectangular plates, and the side plate 18 of the bucket 17, Since the welded portion of the bucket 21 to the side plate 22 is small, it is more easily deformed than the block-shaped base side fixing member 28. Therefore, in order to prevent the bucket-side replacement members 34, 38 from being deformed by the impact when they collide with the base-side replacement members 29, 30, the bucket-side replacement members 34, 38 may be formed using wear-resistant steel. desirable.

The clamshell bucket 11 according to this embodiment has the above-described configuration, and the excavation work of the shaft P using the clamshell bucket 11 will be described below.

First, as shown in FIG. 1, after driving the shaft excavator 1 to the vicinity of the shaft P, the boom 8 of the working device 4 is extended forward, and the multi-stage telescoping arm 9 is extended in a direction perpendicular to the ground. let Then, while the buckets 17 and 21 of the clamshell bucket 11 are held in the open position, the first inner cylinder 9B and the second inner cylinder 9C are extended from the outer cylinder 9A of the arm 9. is grounded to the bottom of the shaft P (bottom of the hole). In this state, earth and sand at the bottom of the shaft P can be scooped out by rotating the buckets 17 and 21 from the open position to the closed position.

After scooping up the earth and sand with the clamshell bucket 11, the first inner cylinder 9B and the second inner cylinder 9C are accommodated in the outer cylinder 9A of the arm 9, and the arm 9 is contracted. In this state, the clamshell bucket 11 can be extracted upward from the shaft P by lifting the tip of the boom 8 upward and rotating the arm 9 on the tip side of the boom 8. After extracting the clamshell bucket 11 upward from the shaft P, the upper rotating body 3 is rotated to move the clamshell bucket 11 above a dump truck (not shown). Then, by rotating the buckets 17 and 21 from the closed position to the open position, the excavated earth and sand is discharged onto the loading platform of the dump truck.

After discharging the earth and sand in this manner, the upper revolving body 3 is rotated to place the clamshell bucket 11 above the shaft P, and the above-mentioned process is repeated to excavate the shaft P deep underground. I can do it.

Here, during the excavation work of the shaft P, the buckets 17 and 21 that constitute the clamshell bucket 11 repeat opening and closing operations. When the buckets 17 and 21 rotate from the closed position to the open position, the bucket-side contact members 32 and 36 provided on the bucket 17 collide with the base-side contact member 27 provided on the base member 12. This sets the open position (maximum opening degree) of the buckets 17 and 21, and prevents excessive load from acting on the hydraulic cylinder 13 due to the tube 13A of the hydraulic cylinder 13 moving beyond the appropriate range. .

In this case, as the buckets 17 and 21 repeatedly open and close, the bucket-side replacement member 34 of the bucket-side contact member 32 repeatedly collides with the base-side replacement member 29 of the base-side contact member 27, and The bucket-side replacement member 38 of the contact member 36 repeatedly collides with the base-side replacement member 30 of the base-side contact member 27 . Therefore, the bucket-side replacement members 34, 38 and the base-side replacement members 29, 30 gradually wear out, deform, etc. due to the impact upon collision.

In contrast, in the present embodiment, the base-side replacement members 29 and 30 can be easily replaced with the base-side fixing member 28 fixed to the base member 12 using the bolts 31. Furthermore, the bucket-side replacement member 34 can be easily replaced with the bolt 35 for the bucket-side fixing member 33 fixed to the bucket 17, and the bucket-side fixing member 37 fixed to the bucket 21 can be easily replaced with the bolt 35. 35, the bucket side replacement member 38 can be easily replaced. Thereby, work efficiency can be improved when replacing the base side replacement members 29, 30 and the bucket side replacement members 34, 38 that have been worn out, deformed, or the like.

Furthermore, in this embodiment, the base side replacement members 29 and 30 are formed using, for example, general structural rolled steel, and the bucket side replacement members 34 and 38 have higher hardness and wear resistance than general structural rolled steel. It is made of wear-resistant steel with excellent wear resistance. As a result, the base-side replacement members 29 and 30 that mainly constitute the base-side contact member 27 are worn out, so the bucket-side replacement member 34 of the bucket-side contact member 32 and the bucket-side replacement member of the bucket-side contact member 36 are worn out. 38 can be saved, and the workability of the replacement work can be further improved.

Furthermore, in this embodiment, when attaching the base-side replacement members 29 and 30 that constitute the base-side contact member 27 to the base-side fixing member 28 using the bolts 31, the notch groove provided in the base-side fixing member 28 is 28D can be fitted with fitting protrusions 29C and 30C provided on the base side replacement members 29 and 30. As a result, even if a large load is applied to the base side replacement member 29 due to a collision of the bucket side replacement member 34, this load is received by the fitting portion between the notch groove 28D and the fitting protrusion 29C before the bolt 31. be able to. Similarly, even if a large load is applied to the base side replacement member 30 due to a collision of the bucket side replacement member 38, this load is received by the fitting portion between the notch groove 28D and the fitting protrusion 30C before the bolt 31. be able to. As a result, the bolts 31 can be prevented from breaking, and the base-side replacement members 29, 30 can be reliably attached to the base-side fixing member 28 for a long period of time.

On the other hand, when attaching the bucket-side replacement member 34 constituting the bucket-side contact member 32 to the bucket-side fixing member 33 using the bolt 35, the bucket-side replacement member 34 is inserted into the notch groove 33C provided in the bucket-side fixing member 33. 34C of fitting protrusions provided in can be fitted. Furthermore, when attaching the bucket-side replacement member 38 that constitutes the bucket-side contact member 36 to the bucket-side fixing member 37 using the bolt 35, the bucket-side replacement member 38 is inserted into the notch groove 37C provided in the bucket-side fixing member 37. 38C of fitting protrusions provided in can be fitted. As a result, even if a large load is applied to the bucket-side replacement members 34, 38 due to a collision between the base-side replacement members 29, 30, this load is transferred to the fitting portion between the notch groove 33C and the fitting protrusion 34C, and the notch. It can be received by the fitting portion between the groove 37C and the fitting protrusion 38C. As a result, the bolts 35 can be prevented from breaking, and the bucket-side replacement members 34, 38 can be reliably attached to the bucket-side fixing members 33, 37 for a long period of time.

Thus, the clamshell bucket 11 according to the embodiment is rotatably supported by the base member 12 attached to the distal end side of the arm 9 constituting the working device 4 and by the base member 12 via the support pins 20 and 24. A pair of buckets 17 and 21 that are displaced between an open position where they are separated from each other and a closed position where they are close to each other, a base side contact member 27 that is provided on the base member 12, and a pair of buckets 17 and 21 that are respectively provided, Bucket-side abutting members 32 and 36 are provided that abut the base-side abutting member 27 when the buckets 17 and 21 are displaced to the open position.

The base-side abutting member 27 includes a base-side fixing member 28 fixed to the base member 12 and base-side exchange members 29 and 30 replaceably attached to the base-side fixing member 28. The abutting members 32 and 36 are bucket-side fixing members 33 and 37 fixed to the buckets 17 and 21, and bucket-side fixing members 33 and 37 that are replaceably attached to the bucket-side fixing members 33 and 37 and that abut the base-side replacement members 29 and 30. It is composed of side exchange members 34 and 38.

According to this configuration, even if the base-side replacement members 29, 30 and the bucket-side replacement members 34, 38 are worn out or deformed due to repeated collisions due to the opening and closing operations of the buckets 17, 21, the base-side fixing members 28 The base-side replacement members 29 and 30 can be easily replaced, or the bucket-side replacement members 34 and 38 can be easily replaced with respect to the bucket-side fixing members 33 and 37. This makes it possible to improve workability when repairing wear and deformation of the base-side contact member 27 and the bucket-side contact members 32 and 36.

In the embodiment, the base-side replacement members 29, 30 and the bucket-side replacement members 34, 38 are formed using materials with different hardnesses. According to this configuration, when the base side replacement members 29, 30 and the bucket side replacement members 34, 38 repeatedly collide, the material with lower hardness among the base side replacement members 29, 30 and the bucket side replacement members 34, 38 Components formed using these materials will preferentially experience wear and deformation. As a result, it is possible to save time and effort in replacing members formed using materials with high hardness, and it is possible to improve work efficiency when replacing the base side replacement members 29, 30 and the bucket side replacement members 34, 38. can.

In the embodiment, the base-side fixing member 28 is provided with a notch groove 28D, and the base-side replacement members 29, 30 are provided with a notch groove 28D with the base-side replacement members 29, 30 attached to the base-side fixing member 28. Fitting protrusions 29C and 30C that fit together are provided. The bucket side fixing members 33, 37 are provided with cutout grooves 33C, 37C, and the bucket side replacement members 34, 38 are provided with notch grooves 33C, 37C when the bucket side replacement members 34, 38 are attached to the bucket side fixation members 33, 37. Fitting protrusions 34C and 38C that fit into 33C and 37C are provided.

According to this configuration, even if a large load is applied to the base-side replacement members 29, 30 due to a collision between the bucket-side replacement members 34, 38, this load is transferred to the notch grooves 28D, 28D and the fitting protrusions 29C, 30C. This can prevent the base side replacement members 29, 30 from coming off due to breakage of the bolt 31 or the like. Similarly, even if a large load is applied to the bucket-side replacement members 34, 38 due to a collision between the base-side replacement members 29, 30, this load is transferred to the fitting portion between the notch groove 33C and the fitting protrusion 34C, and the notch. It can be received by the fitting portion between the groove 37C and the fitting protrusion 38C. This can prevent the bucket-side replacement members 34 and 38 from coming off due to breakage of the bolt 35 or the like.

In the embodiment described above, the notch groove 28D is formed in the base-side fixing member 28 constituting the base-side contact member 27, and the fitting protrusions 29C, 30C are formed in the base-side replacement members 29, 30. Moreover, notch grooves 33C, 37C are formed in the bucket side fixing members 33, 37 constituting the bucket side abutting members 32, 36, and fitting protrusions 34C, 38C are formed in the bucket side replacement members 34, 38. However, the present invention is not limited to this. For example, as in a modified example shown in FIG. The bucket-side abutting members 32', 36' constitute the abutting member 27', and the bucket-side fixing members 33', 37' without notched grooves and the bucket-side replacement members 34', 38' without engagement protrusions make up the abutting members 32', 36'. may be configured.

Furthermore, in the embodiment, a case is illustrated in which the notch groove 28D is formed in the base side fixing member 28 constituting the base side abutting member 27, and the fitting protrusions 29C, 30C are formed in the base side replacement members 29, 30. There is. However, the present invention is not limited to this, and for example, a fitting protrusion may be formed on the base-side fixing member, and a notch groove may be formed on the base-side replacement member. This also applies to the bucket side abutting member.

In the embodiment, the linear notch groove 28D formed in the base side fixing member 28 and the base side exchangeable member 29 and 30 are illustrated as linear fitting protrusions 29C and 30C. However, the present invention is not limited to this. For example, a circular hole may be formed in one of the base-side fixing member and the base-side replacement member, and a cylindrical projection that fits into the circular hole may be formed in the other member. It may also be a configuration. This also applies to the bucket side abutting member.

Furthermore, in the embodiment, a case is illustrated in which the hardness of the material forming the bucket-side exchange members 34 and 38 is higher than the hardness of the material forming the base-side exchange members 29 and 30. However, the present invention is not limited to this. For example, the hardness of the material forming the bucket-side replacement members 34 and 38 may be lower than the hardness of the material forming the base-side replacement members 29 and 30.

4 Working device 11 Clamshell bucket 12 Base member 17, 21 Bucket 20, 24 Support pin 27, 27' Base side contact member 28, 28' Base side fixing member 29, 30, 29', 30' Base side replacement member 32 , 36, 32', 36' Bucket side contact member 33, 37, 33', 37' Bucket side fixing member 34, 38, 34', 38' Bucket side replacement member 28D, 33C, 37C Notch groove (concave fitting Department)
29C, 30C, 34C, 38C Fitting protrusion (convex fitting part)

Claims (3)

a base member attached to the tip side of the arm that constitutes the working device;
a pair of buckets rotatably supported by the base member via support pins and displaced between an open position where they are separated from each other and a closed position where they are close to each other;
a base-side contact member provided on the base member;
A clamshell bucket comprising: a bucket-side abutting member provided on each of the pair of buckets and abutting the base-side abutting member when the pair of buckets is displaced to the open position;
The base-side abutting member includes a base-side fixing member fixed to the base member, and a base-side replacement member replaceably attached to the base-side fixing member,
The bucket-side abutting member includes a bucket-side fixing member fixed to the pair of buckets, and a bucket-side exchange member that is replaceably attached to the bucket-side fixing member and abuts the base-side exchange member. A clamshell bucket characterized by: The clamshell bucket according to claim 1, wherein the base side replacement member and the bucket side replacement member are formed using materials having different hardnesses. The base-side fixing member and the base-side replacement member are provided with concave-convex fitting portions that fit into each other when the base-side replacement member is attached to the base-side fixing member,
The bucket-side fixing member and the bucket-side exchange member are provided with a concave-convex fitting portion that fits into each other when the bucket-side exchange member is attached to the bucket-side fixing member. The clamshell bucket according to item 1.

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