JP2989481B2 - Impact excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a percussion type excavator such as a drilling machine and a rock drill.

[0002]

2. Description of the Related Art When excavating a pier or the like on the ground, a percussion excavator is often used.

FIG. 2 shows an example of such a percussion excavator. As shown in FIG. 2, on the ground 51, a rotating device 24 for rotating the drill rod 23 is installed. A hitting drill 22 is provided at the tip of the drill rod 23. The striking drill 22 supports the striking bit 21 for striking the ground 51 so as to be vertically movable. Drill rod 23
Is connected to one end of a hose 26 via a swivel joint 25. At the other end of the hose 26, a lubricating oil supply device 27 for supplying lubricating oil to the impact drill 22 and an air compressor 2 for sending compressed air to the impact drill 22
8 are connected to each other.

In such a percussion excavator, the rotating device 2
When the compressor 4 and the air compressor 28 are operated, the striking bit 21 strikes the ground 51 while rotating.
Thereby, the pier 52 is excavated in the ground 51.

[0005] The size of the diameter of the upright 52 depends on the diameter of the striking bit 21. For this reason, when excavating a pier having a diameter larger than the diameter of the impact bit (about 60 to 700 mm), it is necessary to bundle a plurality of impact drills each having a relatively small diameter (about 60 to 200 mm). In summary, a large diameter (approximately 700 to 2000 mm) is formed, or the impact drill is arranged so as to form an annular shape, so that a large diameter (outer diameter of approximately 1000 to 2000 mm, inner diameter of approximately 800 to 1 mm) is obtained.
(800 mm).

[0006]

However, in the case of excavating the ground with a percussion drill having a plurality of percussion drills as described above, if the hardness of the ground hit by each percussion bit varies, The vertical movement of each impact bit varies, so that not only the excavation efficiency is significantly reduced, but also excavation becomes impossible. That is,
If the ground struck by a given hitting bit is soft, the repulsive force received from the ground of the hitting bit is small, and the compressed air is biased to the hitting drill of the hitting bit so that the repulsive force received by each hitting bit is uniform. This is because the amount of compressed air to other striking drills decreases and the striking force of each striking bit decreases.

[0007]

[0008]

[Means for Solving the Problems ] To solve the above-mentioned problems.
A percussion excavator according to the present invention comprises: a casing;
A striking bit provided reciprocally at the distal end side of the inside of the casing and having a bit cutter for striking the excavated body at the tip, and reciprocating within the casing at the base end side of the striking bit. in provided and percussion drilling machine having a striking drill having a piston hammer strikes the base end of the striking bits, relative to the casing
And a tension coil spring for suspending and supporting the hitting bit .

Here, a plurality of impact drills are provided.

[0010]

[0011]

According to the striking excavator of the present invention, when the piston hammer striking the drill strikes the striking bit, bit cutter striking bit strikes the object to be excavated material, drilling the drilling member. At this time, if the body to be excavated is hard, the impact bit returns to its initial position by receiving a repulsive force from the body to be excavated, and is hit again by the piston hammer. On the other hand, when the excavated body is soft, the striking bit returns to the initial position by receiving the urging force from the extension coil spring instead of the repulsive force from the excavated body, and is again struck by the piston hammer. .

In the case of a percussion drill having a plurality of percussion drills, the reciprocation of the percussion bits does not vary even if the hardness of the excavated object varies for each percussion bit.

[0013]

1 shows an embodiment of a percussion excavator according to the present invention.
This will be described with reference to FIG. FIG. 1 is a sectional view of the main part.

As shown in FIG. 1, a cylindrical impact bit guide 3 is fitted into the tip of a cylindrical casing 2 of the impact drill 1. A striking bit 4 having a bit cutter 4a at its tip is inserted into the striking bit guide 3 so as to be vertically movable. Between the striking bit guide 3 and the striking bit 4, a tension coil spring 5 as a biasing means is provided so that the striking bit 4 is inserted inside. The tension coil spring 5 has an upper end fixed to the striking bit guide 3 and a lower end fixed to the striking bit 4. That is, the impact bit 4 is suspended and supported by the extension coil spring 5.

On the other hand, a piston hammer 6 for hitting the striking bit 4 is provided at the base end side of the striking bit 4 in the casing 2 so as to be vertically movable.
Is moved up and down by compressed air from an air compressor (not shown).

Such a percussion excavator operates as follows. When compressed air is supplied from the air compressor, the piston hammer 6 moves up and down and strikes the base end of the striking bit 4. The hitting bit 4 hits the ground as an excavated body, receives a repulsive force from the ground, returns upward, and is hit again by the piston hammer 6. By repeating these operations, the cutter bit 4a of the impact bit 4 excavates the ground.

If the ground during excavation changes in the middle and softens, the repulsive force of the impact bit 4 received from the ground becomes small. However, the tension coil spring 5 suspends and supports the striking bit 4, that is, the striking bit 4 is biased by the tension coil spring 5 in a direction opposite to the striking direction. Works to return the hit bit 4 in place of. Thus, the vertical movement of the impact bit 4 is continued.

Therefore, even if the hardness of the ground softens in the middle, excavation can be continued as it is.

Therefore, if a plurality of impact drills 1 as described above are provided to constitute an impact type excavator, a certain impact bit 4
Even if only the ground to be struck is soft, the striking bit 4 operates as described above, and the other striking bit 4
Therefore, the compressed air from the air compressor does not shift to the impact bit 4. Therefore, even if the hardness of the ground for each impact bit varies, the excavation efficiency does not decrease.

[0020]

[0021] In this embodiment, the compressed air from the air compressor, but the piston hammer 6 is moved up and down, by performing the hydraulic pressure regulation using a hydraulic device, even if the piston hammer 6 is moved up and down Good.

[0022]

As described above, according to the impact-type excavator of the present invention, the impact bit has the piston hammer of the impact drill.
Hit and the bit cutter of the hit bit hits the excavated body
When the excavated body is soft, the tension coil spring
Pulls the striking bit back to its original position,
Bit reciprocation can be continued without any problem
You. Therefore, even if the hardness of the body to be excavated softens halfway, excavation can be continued as it is.

Further, in the case of a percussion type excavator having a plurality of percussion drills, even if the repulsive force received from the excavated body for each percussion bit varies, the reciprocating motion of each percussion bit varies. Therefore, even if the hardness of the excavated object varies, not only excavation is possible but also the excavated object can be excavated without lowering the efficiency.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a percussion excavator according to the present invention.

FIG. 2 is a schematic configuration diagram of a percussion excavator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impact drill 2 Casing 3 Impact bit guide 4 Impact bit 5 Extension coil spring 6 Piston hammer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Showa 52-70101 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) E21B 4/14 E21B 4/04 E21B 10 / 36-10/40

Claims (2)

(57) [Claims] 1. A casing, and a casing inside the casing.
It is provided reciprocally at the tip end and strikes the excavated body at the tip.
A hitting bit provided with a hitting bit cutter;
Reciprocable inside the casing at the base end of the hammer bit
And a piston that strikes the base end of the impact bit
Percussion drilling machine equipped with a percussion drill having a hammer
Hang the hitting bit against the casing
A percussion type excavator, comprising a tension coil spring for lowering and supporting . 2. The method according to claim 1, wherein a plurality of said impact drills are provided.
The impact type excavator according to claim 1, characterized in that: