JPS5831650Y2 - 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 performed by hydraulic pressure, and the valve operation and piston operation are performed by hydraulic pressure from the same hydraulic power source, while the pressure oil that operates the valve is returned to the oil tank.

The amount of pressure oil consumed for valve operation is approximately 3 of the total pressure oil consumption.
Reach 0 and press the button.

The amount of pressure oil consumed for piston operation is approximately 70% of the total pressure oil consumption.
Because of this, there was a problem that the efficiency of the reciprocating movement of the piston was poor relative to the capacity of the hydraulic power source, and the rock drilling efficiency was poor.

The present invention has been made in view of the above points, and includes forming a valve oil drain chamber in the cylinder according to the reciprocating motion of the piston, communicating the valve oil drain chamber with the valve rear chamber, and creating a valve oil drain chamber that communicates with the valve rear chamber. The volume of the piston increases or decreases as the piston reciprocates,
By sucking the waste oil used for valve operation into the valve oil drain chamber, and supplying the sucked waste oil to the valve rear chamber again to operate the valve, the amount of oil used for pulp operation can be reduced. The present invention provides a reciprocating device for a striking piston of a hydraulic striking tool that significantly improves rock drilling efficiency.

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

<Example 1> As shown in FIG. 1, in this example, a percussion piston 3 is slidably fitted into a cylinder 2 formed in a main body 1 of a hydraulic percussion tool, and the piston 3 is axially It reciprocates in the front-rear direction and strikes the shank rod 4 with its front end.

The cylinder 2 has a front small diameter section 5, a front large diameter section 6, a rear large diameter section 7, and a rear small diameter section 8.

The piston 3 has a front small diameter section 9, a front large diameter section 10, an annular port 11, a rear large diameter section 12, and a rear small diameter section 13 formed in this order, and the outer diameter A of the rear large diameter section 12 is equal to the front large diameter section. It is formed to be thicker than the outer diameter of the portion 10.

The outer diameter of the rear small diameter portion 13 is smaller than the bottom diameter of the annular port 11, and the rear pressure surface 14 of the rear large diameter portion 12 is larger than the front pressure surface 15 of the front surface. .

The front small diameter part 5, the front large diameter part 6, the rear large diameter part 7, and the rear small diameter part 8 of the cylinder 2 have the front small diameter part 9, the front large diameter part 10, and the rear large diameter part of the piston 3, respectively. 12. The rear small diameter portion 13 is in sliding contact, and the inner diameter of the front large diameter portion 6 of the cylinder 2 is formed smaller than the inner diameter of the rear large diameter portion 7 corresponding to the front and rear large diameter portions 10.12 of the piston 3. ing.

It was a cabinet. Inside the cylinder 2, a front chamber 16 and a rear chamber 11 are defined by the rear large diameter portion 12 of the piston 3.

One end of a front chamber oil supply passage 18 is opened in the front chamber 16 at approximately the center of the front large diameter portion 6, and a rear chamber oil supply passage 19 is opened in the rear chamber 17.
One end is opened at the rear of the rear large diameter section 7 via the oil passage opening/closing valve 20, and one end of the cylinder oil drain passage 21 is opened at the front outer peripheral edge of the rear small diameter section 8 via the valve 20. 1. The rear large diameter portion 1 of the cylinder 2 is formed slightly behind the opening of the front chamber oil supply passage 18.

The other ends of the front and rear chamber oil supply passages 18 and 19 are both connected to an oil chamber 22, and the oil chamber 22 is provided with an accumulator 23 and is connected to a hydraulic pressure source.

The other end of the cylinder oil drain path 21 is connected to an oil tank (not shown).

The valve 20 is provided from the rear large diameter part 7 to the rear small diameter part 8 of the cylinder 2, and an annular valve body 24 is provided concentrically with the piston 3, so that a rear chamber 2 is provided behind the valve body 24.
5 is formed.

The valve body 24 has a large diameter portion 26 at the rear, a medium diameter portion 2γ at the center, and a small diameter portion 28 at the front.

The rear pressure surface 29 of the rear surface of the large diameter section 26 is located at the middle diameter section 27.
A first front pressure surface 30 on the front surface (step surface between the medium diameter section 27 and the small diameter section 28) and a second front pressure surface 3 on the front surface of the small diameter section 28.
It is formed thicker than 1.

The valve body 24 moves in the front-rear direction to open and close the opening of the rear chamber oil supply passage 19 with the medium diameter portion 2γ and the small diameter portion 28, while
The small diameter portion 28 opens and closes the cylinder oil drain path 21, and the first front pressurizing surface 30 is always open to the rear chamber oil supply path 19, and oil pressure is always applied thereto.

One end of a first oil passage 32 is opened in the rear chamber 25 of the valve 20, and the other end of the first oil passage 32 is opened in the front end of the rear large diameter portion 7 of the cylinder 2, and is in constant communication with the annular port 11. are doing.

Additionally, when the front large-diameter portion 10 of the piston 3 moves rearward from the opening of the front chamber oil supply passage 18 in the cylinder 2, as shown in FIGS. Large diameter portion 6, rear large diameter portion 7, and front large diameter portion 10 of piston 3
, annular port 11. A valve oil drain chamber 33 is formed by the rear large diameter portion 12, and the valve oil drain chamber 33, the first oil passage 32, and the valve rear chamber 25 are in communication with each other and are sealed.

Furthermore, although not shown, when the front end of the front large diameter portion 10 of the piston 3 moves forward from the opening of the front chamber oil supply passage 18,
A buffer chamber is formed by the front small diameter part 5 and the front large diameter part 6 of the cylinder 2 and the front small diameter part 9 and the front large diameter part 10 of the piston 3, and the sealed pressure oil is used to move the piston 3 to the most advanced position. is regulated.

Next, the operation will be explained.

FIG. 1 shows the shank rod 4 being struck when the piston 3 has moved forward. In this state, pressure oil is supplied to the front chamber 16 of the cylinder 2 from the front chamber oil supply passage 18, and the pressure oil is supplied to the front chamber 16 of the cylinder 2. It pressurizes the front pressure surface 15 and is also supplied to the rear chamber 25 of the valve 20 via the first oil passage 32, thereby pressurizing the rear pressure surface 29 of the valve 20.

Therefore, since the rear pressure surface 29 of the valve body 24 is thicker than the first and second front pressure surfaces 30.degree. Road 2
1 is opened, and the rear chamber 17 of the cylinder 2 is communicated with the oil tank.

Therefore, since no hydraulic pressure is acting on the rear pressure surface 14 of the piston 3, the piston 3 begins to retreat.

The piston 3 moves backward, and as shown in FIG. When it comes into contact with the inner peripheral surface, the valve oil drain chamber 33 is formed and the first oil passage 3
2 and the front chamber oil supply path 18 are cut off.

Subsequently, when the piston 3 retreats, the volume of the valve oil drain chamber 33 expands as the piston 3 retreats, and with this expansion, the oil in the first oil passage 32 and the valve rear chamber 25 flows into the valve drain oil. It is sucked into the chamber 33.

The valve body 24 moves rearward due to the suction action of oil into the valve oil drain chamber 33 and the hydraulic action on the first front pressurizing surface 30, and as the piston 3 retreats, the valve body 24 also retreats, and the piston 3 moves near the rearmost end, the valve body 24 opens the opening of the rear chamber oil supply passage 19 and simultaneously closes the opening of the cylinder oil drain passage 21, causing pressure oil to flow into the rear chamber 17 of the cylinder 2. Supplied.

The rear pressure surface 15 of the piston 3 is pressurized by the supply of pressure oil, the piston 3 stops, and then begins to move forward.

When the piston 3 moves forward, as shown in FIG. 3, the volume of the valve oil drain chamber 33 is reduced as the piston 3 moves forward, and as the piston 3 moves forward, the oil in the valve oil drain chamber 33 is transferred to the first oil path. 32 to the valve rear chamber 25, and the rear pressure surface 29 of the valve body 24 is pressurized.

Due to the pressurizing action, the valve body 24 moves forward against the pressurizing actions of the first and second front pressurizing surfaces 30.31.

As the piston 3 moves forward, the valve body 24 also moves forward, closing the rear chamber oil supply path 19 again, and at the same time closing the cylinder oil drain path 21.
to open.

On the other hand, since the rear pressure surface 14 of the piston 3 is larger than the front pressure surface 15, the piston 3 rapidly moves forward and strikes the shank rod 4, returns to the state shown in FIG. 1, and repeats the above-described operation thereafter.

<Example 2> In this example, a valve oil drain passage 34 is provided in the cylinder 2, and a part of the oil drain in the rear chamber 25 of the valve 20 is illustrated, as shown by the dashed line in FIGS. The volume (step difference) of the valve oil drain chamber 33 relative to the rear chamber 25 is made smaller than that of the first embodiment so that the valve oil drain chamber 33 is discharged into a tank that does not contain the oil.

That is, one end of the valve oil drain passage 34 is opened at the rear of the cylinder rear large diameter section 7, and when the piston 3 moves near the rearmost end, the front end of the piston rear large diameter section 12 moves rearward from the opening. , is provided so as to communicate with the valve oil drain chamber 33, and the other end is connected to an oil tank (not shown).

Therefore, while the piston 3 is retracting in the housing near the rearmost end, approximately 1/2 of the oil in the rear chamber 25 of the valve 20 is removed from the valve oil drain chamber 3.
3, and the valve 20 is retracted just before the rear chamber oil supply passage 19 is opened.

When the piston 3 further retreats, as shown in FIG.

The valve oil drain chamber 33 and the valve oil drain path 34 communicate with each other, and the remaining oil in the rear chamber 25 returns to the oil tank via the valve oil drain chamber 33, and as the valve 20 moves back, the oil supply for the rear chamber is completed. The passage 19 can be opened to allow the piston 3 to advance rapidly.

At this time, the opening/closing timing of the valve 20 matches the reciprocating motion of the piston 3, and the opening/closing operation of the valve is accurately performed near the forward end and near the backward end of the piston 3.

As described above, according to the impact piston reciprocating device of the hydraulic impact tool of the present invention, the valve oil drain chamber is formed in the cylinder in accordance with the reciprocating movement of the piston, and the valve oil drain chamber and the valve rear chamber are formed. Along with the communication, the volume of the valve oil drain chamber increases or decreases with the reciprocating movement of the piston, and the waste oil used for valve operation is sucked into the valve oil drain chamber, while the sucked waste oil is again supplied to the valve rear chamber. Since the valve is actuated by operating the valve, the amount of oil consumed for valve operation can be reduced, and almost all or most of the total pressure oil consumption can be used for piston operation. The efficiency of the reciprocating motion is significantly improved compared to the conventional method, and rock drilling efficiency can be greatly improved.

[Brief explanation of drawings]

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. FIG. 3 is a central vertical cross-sectional view of the same, showing the piston when it is moving forward. 1...Body, 2...Cylinder, 3...
...Piston, 10...Front large diameter part, 11
...Annular port, 12...Rear large diameter section, 14...Rear pressure surface, 15...Front pressure surface, 16... - Front chamber, 11... Rear chamber, 18... Front chamber oil supply path, 19... Rear chamber oil supply path, 20... Valve, 21・・・・・・
・Cylinder oil drain path, 24... Valve body, 25...
... Rear chamber, 29 ... Rear pressure surface, 30 ...
...First front pressure surface, 31...Second front pressure surface, 32...First oil passage, 33...Valve oil drain chamber, 34... ...Valve oil drain path.

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 closer than the front pressure surface, and the rear pressure surface of the valve is The rear chamber of the valve is larger in shape than the front pressurizing surface, and has one end opened 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 opened and closed by the valve. The cylinder oil drain passage is connected, and the outer diameter of the rear large diameter portion formed on the rear side of the annular port of the piston is made larger than the outer diameter of the front large diameter portion formed on the front side of the annular port. , the inner diameter of the cylinder slightly rearward of the opening of the front chamber oil supply passage is made larger than the inner diameter of the cylinder at the opening of the front chamber oil supply passage in accordance with the large diameter of the rear large diameter portion. A valve oil drain chamber is formed by each level difference between the cylinder p and the piston, and when the piston moves forward and backward, the drain oil in the valve rear chamber is transferred to the valve oil drain chamber and the valve rear chamber through the first oil passage. A blow piston reciprocating device for a hydraulic blow tool, characterized in that the blow pistons are exchanged alternately.