JPH0750150Y2 - Rectangular Chisel Holder Bush for Hydraulic Breaker - Google Patents

Description

[Detailed description of the device]

[0001]

[Field of Industrial Application] The present invention relates to a technology related to a hydraulic breaker used for crushing rocks, roads and structures, crushing, and various other crushing work. The present invention relates to a rectangular chisel holder bush for a hydraulic breaker that allows a conventional chisel for a hydraulic breaker, which has a rectangular cross section to directly destroy and crush rocks and the like, to be mounted on a conventional hydraulic breaker as it is.

[0002]

2. Description of the Related Art Conventionally, hydraulic breakers have been used for various kinds of breaking and crushing work such as rock breaking, road and building breaking, and crushing. A hydraulic breaker is usually used by mounting it on the arm of a hydraulic excavator.The built-in piston uses hydraulic power to reciprocate up and down at high speed, and the falling piston strikes the rear end of the chisel and rocks the chisel. It has a structure that destroys and crushes.

A chisel holder for mounting and holding a chisel is provided below the hydraulic breaker, and the rear end of the chisel is inserted and held in the chisel holder. In addition, a chisel holder bush is attached to the opening at the lower end of the chisel holder in the gap between the opening and the inserted chisel to prevent the chisel from weakening in strength at the opening.

By the way, when rocks and the like are directly broken and crushed by a chisel of a hydraulic breaker, the chisel is used in a state in which its tip is slightly vertical to the hydraulic excavator side instead of being vertical. The chisel attached to the hydraulic breaker is shown in Fig. 7.
The cross section is circular as shown in FIG.

[0005]

[Problems to be Solved by the Invention] As described above, when directly breaking or crushing rocks etc. with the chisel of the hydraulic breaker, the chisel is used not in a vertical state but in a slightly inclined state. Bending stress is generated in addition to the stress, and the bending stress easily causes cracks.

Particularly, since the conventional chisel has a circular cross section, as shown in FIG. 6, a portion of the circular cross section having a distance y farthest from the neutral axis NN against bending stress of the circular cross section is circular green. The bending stress concentrates at one point P of this circular peripheral edge, and cracks easily occur. Then, there is a drawback that cracks generated by concentrating bending stress at one point are gradually expanded to damage the chisel e.

The present invention has been made in view of the above problems and was devised to solve the problems. The purpose is to insert and hold a conventional chisel having a circular cross section. Another object of the present invention is to provide a rectangular chisel holder bush for a hydraulic breaker, which allows a chisel having a rectangular cross section to be directly inserted and held in a chisel holder.

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 has an opening d formed at the lower end of a chisel holder c provided at a lower portion of a hydraulic breaker a, and In the gap with the chisel 1 inserted in the opening d,
The outer periphery of the chisel holder bush 2 to be inserted and attached is formed in a shape corresponding to the inner periphery of the opening d, and the inner periphery of the chisel holder bush 2 can be fixedly inserted and fixed by the chisel 1 having a rectangular cross section. It is configured to have a different shape.

[0010]

The present invention having the above-described structure operates as follows. That is, in the rectangular chisel holder bush for hydraulic breaker according to the first aspect, the chisel having the rectangular cross section can be inserted and held as it is in the chisel holder in which the conventional chisel having the circular cross section is inserted and held. Act on.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more concretely with reference to the embodiments shown in the drawings. Here, FIG. 1 is a cutaway perspective view in which a rectangular chisel is attached to a hydraulic breaker, and FIG.
2A is a front view of the rectangular chisel, FIG. 2B is a side view of the rectangular chisel, FIG. 2C is a view taken along the line AA of FIG. 2A, and FIG. 3A is a rectangular chisel holder. Bush front view, Figure 3
3B is a side view of the rectangular chisel holder bush, FIG.
3C is a sectional view taken along the line AA of FIG. 3A, FIG. 4 is a sectional view in which a rectangular chisel is attached to a hydraulic breaker, and FIG. 5 is a sectional view for explaining stress in the rectangular cross section of the rectangular chisel. .

In the figure, a hydraulic breaker a is usually used by being mounted on an arm of a hydraulic excavator (not shown), and a piston b which reciprocates up and down at high speed by using hydraulic power as a power source is built therein. Below the piston b, the rear end portion 1a side of the rectangular chisel 1 is inserted. The hydraulic breaker a reciprocates a built-in piston b with hydraulic power as a power at high speed up and down, hits the rear end 1a of the rectangular chisel 1 with the descending piston b, and rocks etc. with the rectangular chisel 1. It is designed to be destroyed and crushed.

The rectangular chisel 1 has a rectangular cross section of a portion projecting downward from the hydraulic breaker a and a portion held by a chisel holder bush 2 attached to an opening d at a lower portion of the hydraulic breaker a. There is. In this embodiment, the rectangle is in the shape of a rectangle close to a square. The cross section of the rectangular chisel 1 is formed in the same shape as the conventional chisel e having a circular cross section shown in FIG.

When the rectangular chisel 1 is divided into a rear end portion 1a, a rear portion 1b, a narrowed portion 1c, a protruding portion 1d, and a cutting edge 1e according to the shape, the protruding portion 1d has a rectangular cross section. The boundary between the protruding portion 1d and the narrowed portion 1c is formed such that the four corners of the rectangle gradually become circular toward the narrowed portion 1c side.

A bending stress is generated in the protruding portion 1d when the rock or the like is broken or crushed by the rectangular chisel 1, but since the cross section is rectangular, the bending stress of the rectangular cross section is as shown in FIG. Since the part of the distance y farthest from the neutral axis NN is not one point but the whole area of one side of the rectangle, it is possible to prevent the stress concentration due to the bending stress.

Further, the protruding portion 1d is formed with a cutting edge 1e in which both side surfaces of a rectangular shape on the tip side toward the cutting edge side are inclined inward toward each other toward the tip. On the other hand, the rear end portion 1 of the rectangular chisel 1 which is completely inserted into the hydraulic breaker a.
The cross sections of a and the rear portion 1b are circular as in the conventional chisel e.

A rectangular chisel 1 is provided below the hydraulic breaker a.
A chisel holder c for mounting and holding is provided, and a rear end portion 1a, a rear portion 1b, a narrowed portion 1c, and a part of a protruding portion 1d of the rectangular chisel 1 are inserted and held in the chisel holder c. Opening d at the lower end of this chisel holder c
A rectangular chisel holder bush 2 is attached to the space between the opening d and the inserted rectangular chisel 1 to prevent the rectangular chisel 1 from weakening in strength around the opening d.

The rectangular chisel holder bush 2 has an opening d formed at the lower end of the chisel holder c and the opening d.
The rectangular chisel 1 is inserted and attached in a gap with a part of the protruding portion 1d of the rectangular chisel 1. For this reason, the outer circumference of the rectangular chisel holder bush 2 is formed in a shape of the inner circumference of the opening d, that is, a circular shape corresponding to the circular shape. A pin groove 2a that engages with the stopper pin f is formed in a part of the outer circumference of the circle in a direction orthogonal to the direction of a hole 2b described later.

Further, a hole 2b is formed in the rectangular chisel holder bush 2 for inserting a part of the protruding portion 1d of the rectangular chisel 1, and the inner periphery of the hole 2b is the protruding portion of the rectangular chisel 1. The outer shape of 1d is formed into a shape that can be inserted. The rectangular chisel holder bush 2 has a protruding portion 1d.
The inner periphery of the hole 2b of the rectangular chisel holder bush 2 is illustrated in FIG. 3 (A) because the four corners of the protruding portion 1d near the boundary between the narrowed portion 1c and the narrowed portion 1c are attached to the portions that temporarily deform into a circular shape. As shown in the drawing, the upper and lower sides are formed in a straight line parallel to each other, and both ends of the upper and lower sides are rounded in a circular shape, and the continuous left and right sides are circular arcs larger than this. It has a shape that is partly formed.

Since the hole 2b of the rectangular chisel holder bush 2 is formed in the above-described shape, the rectangular chisel 1 is inserted into this hole 2b and fixedly restrained,
The rectangular chisel 1 is sufficiently prevented from vibrating laterally in this portion during the breaking and crushing of rocks, etc., and the rectangular chisel 1 is prevented from being damaged near the opening d of the hydraulic breaker a.

The present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0023]

As is clear from the above description, according to the rectangular chisel holder bush for hydraulic breaker according to the first aspect of the invention, the chisel having a rectangular cross section which can prolong the service life of the chisel has a conventional cross section. The circular chisel can be inserted and held in the chisel holder where it was held, and it can be used as it is without modifying the conventional hydraulic breaker. It is a thing.

[Brief description of drawings]

FIG. 1 is a cutaway perspective view of a rectangular chisel attached to a hydraulic breaker according to an embodiment of the present invention.

FIG. 2A is a front view of a rectangular chisel showing an embodiment of the present invention. (B) is a side view of a rectangular chisel showing an embodiment of the present invention. (C) is an AA arrow view of (A).

FIG. 3A is a front view of a rectangular chisel holder bush showing an embodiment of the present invention. (B) is a side view of a rectangular chisel holder bush showing an embodiment of the present invention. (C) is a sectional view taken along the line AA of (A).

FIG. 4 is a sectional view of a rectangular chisel mounted on a hydraulic breaker according to an embodiment of the present invention.

FIG. 5 is a sectional view for explaining stress in a rectangular section of a rectangular chisel showing an embodiment of the present invention.

FIG. 6 is a cross-sectional view for explaining stress in a circular cross section of a conventional chisel having a circular cross section.

FIG. 7A is a front view of a conventional chisel having a circular cross section. (B) is a side view of a conventional chisel having a circular cross section. (C) is an AA arrow view of (A).

[Explanation of symbols]

1: Rectangular Chisel 1a: Rear End 1b: Rear 1c: Drawing 1d: Projection 1e: Blade Edge 2: Rectangular Chisel Holder Bushing 2a: Pin Groove 2b: Hole a: Hydraulic Breaker b: Piston c: Chisel Holder d: Opening Part e: Chisel f: Stopper pin

Claims (1)

[Scope of utility model registration request] 1. An outer circumference of a chisel holder bush which is inserted and mounted in a gap between an opening formed at a lower end of a chisel holder provided in a lower portion of a hydraulic breaker and a chisel inserted in the opening. A rectangular shape for a hydraulic breaker, characterized in that it is formed in a shape corresponding to the shape of the inner circumference of the portion, and the chisel of the chisel holder bush is formed in a shape in which a chisel with a rectangular cross section can be inserted and fixedly restrained. Chisel holder bush.