JPS5831649Y2 - Hydraulic impact tool impact piston reciprocating device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a striking piston reciprocating device for reciprocating a striking piston in a hydraulic striking tool.

Conventionally, hydraulic impact tools such as rock drills use hydraulic pressure to reciprocate the impact piston installed in the cylinder of the main body, and the supply and discharge of oil in the cylinder that makes the piston reciprocate depends on the reciprocating movement of the piston. It is controlled by an oil passage opening/closing valve that operates accordingly.

The control operation of the valve is also carried out by hydraulic pressure, and while the valve operation and piston operation are carried out by the same hydraulic pressure from the same hydraulic source, the pressure oil that operates the valve is returned to the oil tank.

Approximately 3 kl of pressure oil consumed in the pulp operation of the total pressure oil consumption
0%, and the amount of pressure oil used for piston operation is only about 70q of the total pressure oil consumption, so the efficiency of the reciprocating movement of the piston is poor compared to the capacity of the hydraulic power source, and the rock drilling efficiency is low. There was a problem with it being bad.

The present invention has been made in view of the above points, and the other end of the i-th oil passage, one end of which is connected to the rear chamber of the valve, is communicated with the annular port of the piston, and a part of the i-th oil passage is connected to the rear chamber of the cylinder. The other end of the valve oil drain passage is drawn near the retreating end of the piston so as to communicate with the annular port, and when the piston moves near the retreating end, the waste oil used for pulping is drained from the first oil passage.
By replenishing the rear chamber of the cylinder through an annular port and a valve drainage passage, the oil waste used for pulping is also used for piston operation, which significantly improves rock drilling efficiency. A striking piston reciprocating device for a tool is provided.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention will be explained about an Example based on drawing.

As shown in FIG. 1, a striking piston 3 is slidably fitted into a cylinder 2 provided in a main body 1 of the hydraulic striking tool, and the piston 3 reciprocates in the axial direction (back and forth direction). Hit Shankrondo 4 with the front end.

The cylinder 2 has a front medium diameter section 5, a central large diameter section 6, and a rear small diameter section 7.

Piston 3ri, front medium diameter section 8, front large diameter section 9, annular port 10, rear large diameter section 11. The rear small diameter portion 12 is formed in this order, and the outer diameter of the front large diameter portion 9 and the outer diameter of the rear large diameter portion 11 are formed to be the same diameter.

Further, the outer diameter of the rear small diameter portion 12 is formed to be smaller than the bottom diameter of the annular port 10, and the rear pressure surface 13 on the rear surface of the rear large diameter portion 11 is formed larger than the front pressure surface 14 on the front surface. There is.

The front medium diameter part 5V'i of the cylinder 2, the front medium diameter part 8 of the piston 3, the central large diameter part 6ri, the front part and the rear large diameter part 9.
11, the rear small diameter portion 7 and the rear small diameter portion 12 are brought into sliding contact with each other.

Additionally, inside the cylinder 2, a front chamber 15 and a rear chamber 16 are defined by the rear large diameter portion 11 of the piston 3.

In the front chamber 15, one end of the front chamber oil supply passage 17 is opened at the front part of the central large diameter part 6, and in the rear chamber 16, one end of the rear chamber oil supply passage 18 is opened at the rear end of the central large diameter part 6. At the same time, one end of the cylinder oil drain passage 20 is opened at the front outer peripheral edge of the rear small diameter portion 12 via the valve 19.

The other ends of the front and rear chamber oil supply passages 17, 18 are both connected to an oil chamber 21, and are provided with an oil chamber 21ri an accumulator 22 and connected to a hydraulic power source.

The curved end of the cylinder oil drain passage 20 is connected to an oil tank (not shown).

A ring-shaped valve body 23 is provided from the center large diameter part 6 to the rear small diameter part 7 of the PAL 7''19ri cylinder 2.
A rear chamber 24 is formed at the rear of the valve body 23 by being provided concentrically with the valve body 23 .

The valve body 23 has a large diameter portion 25 at the rear, a medium diameter portion 26 at the center, and a small diameter portion 27 at the front.

The rear pressurizing surface 28 of the rear surface buttoned to the large diameter part 25 is the middle diameter part 26.
A first front pressure surface 29 on the front surface (step surface between the medium diameter portion 26 and the small diameter portion 27) and a second front pressure surface 3 on the front surface of the small diameter portion 27.
It is formed thicker than 0.

The valve body 23ri moves in the front-back direction to open and close the opening of the rear chamber oil supply passage 18 using the medium diameter part 26 and the small diameter part 27, while opening and closing the cylinder oil drain passage 20 of the small diameter part 27ri, and opens and closes the opening of the rear chamber oil supply passage 18. The pressure surface 29 is always open to the rear chamber oil supply passage 18, and hydraulic pressure is always applied thereto.

One end of a first oil passage 31 is opened in the rear chamber 24 of the valve 19, and the other end of the first oil passage 31 is opened in the front part of the central large diameter portion 6 of the cylinder 2, and the front chamber oil supply passage 17 is opened. It is opened slightly rearward than the annular port 1o, and is always in communication with the annular port 1o.

Further, in the rear chamber 16 of the cylinder, a valve oil drain passage 3 is provided at the rear of the central large diameter portion 6 and slightly in front of the rear chamber oil supply passage 18.
2 is opened at one end, and the other end of the pulp oil drain passage 32 is opened at approximately the center of the central large diameter section 6.

The front opening is provided so as to communicate with the annular port 5 when the piston 3 moves near the retreating end, that is, the front end of the rear large diameter portion 11 of the piston 3 is located approximately at the center of the opening.

Although not shown, when the front end of the front large diameter portion 9 of the piston 3 moves forward from the opening of the front chamber oil supply passage 17, the front medium diameter portion 5 of the cylinder 2, the central large diameter portion 6, and the piston A buffer chamber is formed by the front medium diameter portion 8 and the front large diameter portion 9 of the piston 3, and the most advanced position of the piston 3 is regulated by sealed pressure oil.

Next, the operation will be explained.

FIG. 1 shows the state in which the shank rod 4 is struck when the piston 3 has moved forward. Pressure oil is supplied from the front chamber oil supply passage 17 to pressurize the front pressure surface 14 of the piston 3 and the rear chamber 24 of the valve 19 via the first oil passage 31.
The pressure is also supplied to the rear pressurizing surface 28 of the valve 19.

Therefore, since the rear pressure surface 28 of the valve body 23 is larger than the first and second front pressure surfaces 29.30, the valve body 23 is located at the most forward position and closes the rear chamber oil supply passage 18, while the cylinder oil discharge passage 2
0 is opened, and the rear chamber 16 of the cylinder 2 is communicated with the oil tank.

Therefore, since no hydraulic pressure is acting on the rear pressure surface 9 of the piston 3, the piston 3 begins to retreat.

When the piston 3 retreats and the rear end outer circumferential edge of the piston front large diameter section 9 moves rearward from the opening of the front chamber oil supply passage 17 and comes into contact with the inner circumferential surface of the cylinder center large diameter section 6, the 1 oil road 3
1 and the front chamber oil supply path 17 is cut off.

Subsequently, when the piston 3 retreats and moves near the rearmost end, as shown in FIG. , while communicating the first oil passage 31 and the pulp drainage oil passage 32 via the annular port 10, the valve body 23 is dynamically moved by the hydraulic action on the first front pressurizing surface 29, and the valve rear chamber 24 is opened. Pressure oil, that is, drained oil after operating the valve 19, is transferred to the first oil path 31. The oil is supplied to the rear chamber 16 of the cylinder 2 through the annular port 10 and the valve drain passage 32, and pressurizes the rear pressurizing surface 13 of the piston 3.

When the valve body 23 is moved rearward, the opening of the rear chamber oil supply passage 18 is opened, and at the same time, the cylinder oil drain passage 20 is opened.
The opening is closed, and pressure oil is supplied to the rear chamber 16 of the cylinder 2 from the rear chamber oil supply path 18.

The rear pressure surface 9 of the piston 3 is further pressurized by the supply of pressure oil, the piston 3v'i stops, and then begins to move forward.

When the piston 3 moves forward, the piston rear large diameter portion 11 closes the front opening of the valve oil drain path 32, and the valve oil drain path 3
2 and the first oil passage 31 is cut off.

When the piston 3 moves further forward and the rear end of the piston front large diameter section 9 moves forward from the rear end of the opening of the front chamber oil supply passage 17, the front chamber oil supply passage 17 and the first oil passage 31 are connected to each other. Annular port 1
0, pressure oil is supplied to the valve rear chamber 24,
The rear pressure surface 28 of the valve body 23 is pressurized.

Due to this forceful action, the valve body 23 moves forward against the pressurizing action of the first and second front pressurizing surfaces 29,30, and closes the rear chamber oil supply passage 18 again, and at the same time closes the cylinder oil drain passage 20.
Prepare to open the piston 3 and move the piston 3 backward.

On the other hand, the rear pressure surface 13 of the piston 3ri is connected to the front pressure surface 14.
Since it is thicker, it moves forward rapidly and hits the shank rod 4, returns to the state shown in FIG. 1, and repeats the above-mentioned operation.

In this embodiment, the valve oil drain path 32 is formed in the main body 1, but the openings at both ends of the valve oil drain path 32 may be connected by a pipe or the like.

As described above, according to the impact piston reciprocating device of the hydraulic impact tool of the present invention, the first end is connected to the rear chamber of the valve.
The curved end of the oil passage is connected to the annular port of the piston, and 5
The curved end of the valve oil drain path, one end of which is connected to the rear chamber of the cylinder, is placed near the retracting end of the piston so that it communicates with the annular port. Since oil is supplied to the rear chamber of the cylinder through the first oil passage, the annular port, and the pulp drainage oil passage, the waste oil used for valve operation can be used again for the forward movement of the piston. , the forward speed of the piston is improved compared to the conventional method, and rock drilling efficiency can be greatly improved.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the present invention, and FIG. 1 is a central vertical cross-sectional view of the main parts of the hydraulic impact tool when the shank rod is struck, and FIG. 2 is a central vertical cross-sectional view of the main part of the hydraulic impact tool when the piston is retracted. It is a diagram. 1...Body, 2...Cylinder, 3...Piston,
10... Annular port, 13... Rear pressure surface, 14...
... Front pressure surface, 15... Front chamber, 16... Rear chamber, 1
7...Front chamber oil supply path, 18...Rear chamber oil supply path, 19
...Valve, 20...Cylinder oil drain path, 23...
Valve body, 24... Rear chamber, 28... Rear pressure surface, 29.
...First front pressure surface, 30...Second front pressure surface, 31
... 1st oil passage, 32... Valve drain oil passage.

Claims (1)

[Scope of utility model registration request] A striking piston having an annular port formed on its outer periphery is slidably fitted into a cylinder within the striking tool body, one end of the front chamber oil supply passage is opened in a part of the front chamber of the cylinder, and one end of the front chamber oil supply passage is opened in a part of the front chamber of the cylinder. One end of the oil supply passage for the rear chamber is opened in a part of the chamber via an oil passage opening/closing valve, and the rear pressure surface of the piston is formed to be larger than the front pressure surface, and the rear pressure surface of the valve is set to the front side. A first cylinder is formed to be thicker than the pressurizing surface, and in the rear chamber of the valve, one end opens in a part of the cylinder slightly rearward of the opening of the oil supply passage for the front chamber, and communicates with the annular port of the piston.
The other end of the oil passage is connected, and a part of the front pressurizing surface of the valve is always open to the rear chamber oil supply passage, and the other part of the rear chamber of the cylinder is connected to the oil supply passage that is opened and closed by the valve. While connecting the cylinder oil drain passage, there is a valve oil drain passage in a part of the pond in the rear chamber of the cylinder that has one end open in a part of the cylinder so as to extend near the retreating end of the piston and communicate with the annular port. The other end is connected to the first oil passage for draining oil from the valve rear chamber near the retreating end of the piston, and the oil is supplied from the valve oil drain passage to the rear chamber of the cylinder via an annular port. A striking piston reciprocating device for a hydraulic striking tool, characterized by: