JPS62862Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a lock breaker that improves the sealing function of the top seal by making the pressure receiving area of the top seal of the striking piston smaller than the pressure receiving area of the damper chamber side.

As shown in FIG. 1, a conventional lock breaker is provided with a striking piston e having pressure receiving surfaces c and d having different pressure receiving areas in a pressure chamber a and a damper chamber b, respectively. Additionally, a top seal g and a small pressure receiving surface h are provided between the pressure chambers a and f, and the small pressure receiving surface h has a larger pressure receiving area than the pressure receiving surface d facing the damper chamber b. had been formed. Therefore, when the striking piston e reaches the upper limit position, the striking piston e is pushed downward due to the area difference between the pressure receiving surface d and the small pressure receiving surface h, and the sealing at the top seal portion g becomes uncertain and the pressure chamber f is Part of the pressure leaks into pressure chamber a, and then from a to outlet port j
This led to a decrease in volumetric efficiency.

This idea was made to improve this problem by making the area of the small pressure-receiving surface adjacent to the top seal smaller than the area of the pressure-receiving surface on the damper chamber side, so that the impact piston is pushed upward by the pressure inside the damper chamber. The present invention aims to improve the sealing function of the top seal portion and improve the volumetric efficiency by providing a lock breaker having the following structure.

This invention will be explained in detail below with reference to one embodiment shown in FIG. 2 and below. In the figure, 1 is the lock breaker body, which has a barrel 2 inside.
A striking piston 3 is slidably housed therein.

The striking piston 3 has a large diameter part 3a on the upper end side, and pressure receiving surfaces 3b and 3c having different pressure receiving areas are formed at both ends of this large diameter part 3a. A pressure receiving surface 3c having a small pressure receiving area faces the damper chamber 5, and a top seal portion 2a seals between the pressure chamber 4 and a port to be described later when the striking piston 3 reaches its upper limit. A small pressure receiving surface 3d having a smaller area than the pressure receiving surface 3c on the damper chamber 5 side is formed between the pressure receiving surfaces 3b.

In addition, a valve 6 is provided on the outer periphery of the upper end of the barrel 2.
is slidably inserted into the valve 6, and a first port ₆₁ to a fourth port ₆₄ are bored in the valve 6, and the lower end side of the valve 6 is a disc spring housed in the main body 1. 7.

On the other hand, among the ports ₆₁ to ₆₄ of the valve 6, when the valve 6 is in the raised position, the first port ₆₁ , which is a drilled hole, connects the pressure chamber 4 and the return port ₁₂ through the first port ₂₁ of the barrel 2. are communicated with each other.
The second port 6 ₂ communicates with the second port 2 ₂ of the barrel 2, and the third port 6 ₃ communicates with the third port 2 of the barrel 2.
It is connected to the damper chamber 5 via ₃ , and
The third port ₆₃ communicates with the pressure oil supply port ₁₁ through a passage 1a. Further, a drain hole ₂₄ communicating with the drain port ₁₅ of the main body 1 is opened at the lower end side of the barrel 2 _.
On the lower end side, a plurality of wear rings 8 are provided at intervals so as to be in sliding contact with the outer circumferential surface of the striking piston 3. The base end side of a chisel 9, which is struck by the striking piston 3, is housed in the lower end side of the main body 1 so as to be reciprocally movable.

However, when pressure oil is supplied to the pressure oil supply port ₁₁ of the main body 1, the valve 6 is pushed down by this pressure oil against the set pressure of the disc spring 7, and the second port ₆₂ of the valve 6 Pressure oil supply port ₁₁ and port ₂₂ are communicated with each other, and the oil pressure of port ₂₂ increases. When valve 6 is pushed down further,
The port ₁₀₁ of the spool 10, which is pushed down in contact with the valve 6, communicates with the cover 111 of the cover _{11, and the pressure oil supply port 11 communicates} with the pressure chamber 4, so that pressure oil flows into the pressure chamber 4. Ru. The pressure oil flowing into the pressure chamber 4 acts on the pressure receiving surface 3b of the striking piston 3 to fire the striking piston 3, and the tip of the striking piston 3 strikes the chisel 9. striking piston 3
At the same time as the valve 6 is lowered, the valve 6 is pushed up by the disc spring 7, and the pressure chamber 4 is opened to the first port 6 of the valve 6.
₁ communicates with the return port ₁₂ to drain the pressure oil, and at the same time, the pressure oil supplied to the damper chamber 5 through the third port ₆₃ of the valve 6 acts on the pressure receiving surface 3c of the striking piston 3. , the striking piston 3 is returned to its original position.

At this time, since the small pressure receiving surface 3d provided between the top seal portion 2a and the pressure receiving surface 3b is made smaller than the pressure receiving surface 3c on the damper chamber 5 side, the impact piston 3 is reliably pressed upward by the pressure of the damper chamber 5. In addition, since the area relationship of 3d<3c occurs when the pressure oil is rising, pressure oil generates a force that pushes the piston 3 upward, improving the sealing function _.
flow from port 4 to return port ₁₂ . Next, when the pressure in the pressure oil supply port ₁₁ rises again, the valve 6 is pushed down and the above-mentioned operation is repeated, causing the striking piston 3 to strike the chisel 9, thereby generating a force for crushing rocks, etc. on the chisel 9. It is something that makes you

As explained in detail above, this design makes the small pressure-receiving surface adjacent to the top seal that seals between the pressure chamber and the outlet port smaller than the pressure-receiving surface on the damper chamber side, so that when the striking piston reaches its upper limit, the damper chamber Since the impact piston is pressed upward with a pressure of Problems such as this can also be resolved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a part of a conventional lock breaker, and FIG. 2 is a sectional view of a lock breaker according to one embodiment of the present invention. 1 is the lock breaker body, 2 is the barrel, 2a is the top seal portion, 3 is the striking piston, 3b, 3c
is a pressure receiving surface, 3d is a small pressure receiving surface, 4 is a pressure chamber, 5 is a damper chamber, and ₆₂ is a port.

Claims (1)

[Scope of utility model registration request] A striking piston 3 having pressure receiving surfaces 3b and 3c having different pressure receiving areas is housed in a barrel 2 provided in the lock breaker body 1, facing the pressure chamber 4 and the damper chamber 5, and the outer circumference of the barrel 2 is provided with pressure oil. and a top seal for sealing between the pressure chamber 4 and the port 62, in which a valve 6 is provided which alternately supplies pressure oil to the pressure chamber 4 and the damper chamber ₅ by being reciprocated by a disc spring 7. Between the portion 2a and the pressure chamber 4 side pressure receiving surface 3b, the damper chamber 5 side pressure receiving surface 3
A lock breaker formed with a small pressure receiving surface 3d having a smaller area than c.