KR100569198B1 - Hydraulic percussion device - Google Patents

Abstract

The present invention relates to a hydraulic strike device, and more particularly to a hydraulic strike device that can prevent damage to the seal and leakage from the lower hydraulic chamber.

In the hydraulic striking device according to the present invention, the cylinder, the gas chamber of the upper cylinder, the head of the lower cylinder, the upper end and the lower end of the cylinder is accommodated in the gas chamber and the head, respectively, is installed to enable the reciprocating movement up and down inside the cylinder. A piston, a plurality of hydraulic chambers formed by the cylinder and the piston, a plurality of flow paths connected to each of the hydraulic chambers so that fluid flows in and out of the hydraulic chamber to move the pistons up and down, and connected to the hydraulic chambers in conjunction with the reciprocating motion of the pistons. A main control valve for switching the flow path and connecting the upper end part with a chisel installed in the lower part of the piston and connected to the low pressure part through a first return flow path and formed in an annular shape on the inner surface of the cylinder at the lower part of the high pressure chamber; In the hydraulic strike device comprising a return port and a plurality of first seals provided below the first return port, the first ear It is provided on the flow path, characterized by further comprising a first check valve, the pressure in the first return port which is open when the pressure is higher than the low-pressure portion.

Hydraulic Strike, Hydraulic Breaker, Hydraulic Drifter, Hydraulic Hammer

Description

Hydraulic Strike Device {HYDRAULIC PERCUSSION DEVICE}

1a to 1d is a cross-sectional view conceptually showing an embodiment of the conventional hydraulic hammer and its operation

Figure 2 is a cross-sectional view showing an embodiment of the hydraulic hammer according to the invention

3 is a cross-sectional view showing an embodiment of a poppet valve used as the first check valve in one embodiment of the hydraulic striking device according to the present invention.

4 is a cross-sectional view showing an embodiment of a poppet valve used as a second check valve in one embodiment of the hydraulic striking device according to the present invention.

<Short description of the major reference symbols>

11 body 11a cylinder

11 b Head 12 piston

12b, 12c Hydraulic Surface 13 Chisels

14 Main valve 15a High pressure part

15b low pressure part 16 gas chamber

17 Piston inverted hydraulic chamber 18 Low pressure chamber

18a Pilot Port 19 High Pressure Room

17 ', 18', 18a ', 19' Euro 23,25,27

24,26 Return Port 24 ', 26' Return Euro

30,40 Check valve 31,41 Poppet cylinder

31a, 41a Sheet 32,42 Poppet

32a, 32a Seat 33,43 Spring

The present invention relates to a hydraulic striker, and more particularly to a hydraulic striker to prevent damage of the seal and leakage from the lower hydraulic chamber.

The hydraulic strike device is mounted on the arm tip of a construction machine such as a shovel and is used to crush rocks, drill holes, or pile piles in crushing or drilling works. Such a hydraulic strike device is called a hydraulic breaker, a hydraulic drifter, a hydraulic hammer, etc. according to its use or function.

1A to 1D are perspective views illustrating an embodiment of a general hydraulic hammer and its operation.

Referring to the embodiment shown in the drawings, the hydraulic hammer is a cylinder 11a, the gas chamber 16, the head portion 11b, the piston 12, a plurality of hydraulic chambers (17, 18, 19) And a flow path 17 ', 18', 18a ', 19', a main control valve 14, and a chisel 13, which are integrally formed on or installed in the body 11; do.

The cylinder 11a is formed inside the body 11.

The gas chamber 16 is formed above the cylinder 11a, and the upper end of the piston 12 is accommodated therein. The gas chamber 16 is filled with a compressible gas such as nitrogen (N ₂ ). The gas filled in the gas chamber 16 is compressed when the piston 12 is raised to apply pressure to the gas pressure surface 12a of the piston 12 to cushion the rise of the piston 12. In addition, the piston 12 is accelerated downward by expanding when the piston 12 descends and applying pressure to the gas hydraulic pressure surface 12a of the piston 12.

The head portion 11b is formed to have through holes 21 and 22 coaxial with the cylinder 11a in the lower portion of the cylinder 11a. The lower end of the piston 12 and the upper end of the chisel 13 are accommodated in the through holes 21 and 22 of the head portion 11b.

The upper end of the piston 12 is accommodated in the gas chamber 16 and the lower end of the piston 12 is accommodated in the inlet of the upper portion of the through hole 22 of the head 11b, and reciprocates up and down inside the cylinder 11a. This is possibly installed.

The hydraulic chambers 17, 18 and 19 are divided into a plurality of cylinders 11a and the piston 12 so as to include at least a plurality of upper and lower piston reverse hydraulic chambers 17 and a lower high pressure chamber 19. Is formed. The plurality of hydraulic chambers 17, 18, and 19 as described above have a piston 12 having an outer circumferential surface having a plurality of outer diameter portions, and a large diameter outer surface is in close contact with an inner surface of the cylinder 11a, and a small diameter outer surface is the cylinder 11a. It is formed between the cylinder (11a) and the piston 12 by inserting the cylinder (11a) so as to be spaced apart from the inner surface of the. In the figure, a general embodiment is shown in which a low pressure chamber 18 is formed between the piston inversion hydraulic chamber 17 and the high pressure chamber 19 to have three hydraulic chambers. Each of the piston inversion hydraulic chamber 17 and the high pressure chamber 19 is a hydraulic chamber into which a fluid having pressure for accelerating the piston 12 upward and downward flows in and out, and the low pressure chamber 18 is the piston. Corresponds to the hydraulic chamber into which the fluid for operating the main control valve 14 for switching the flow path in order to reverse the vertical motion of (12) flows in and out. In particular, the low pressure chamber 18 can be omitted by changing the structure of the main control valve 14 or by using a separate auxiliary valve (not shown). However, hereinafter, the structure and operation of the hydraulic hammer will be described with reference to the embodiment shown in the drawings having three hydraulic chambers. The piston 12 has a hydraulic pressure surface 12b that is exposed to the interior of the piston inversion hydraulic chamber 17 and is pressurized downward by a fluid flowing in and out of the piston inversion hydraulic chamber 17. In addition, the piston 12 has a hydraulic pressure surface 12c which is exposed to the inside of the high pressure chamber 19 and is pressurized upward by the fluid flowing in and out of the high pressure chamber 19.

The flow paths 17 ', 18', 18a ', and 19' apply pressure to the hydraulic surfaces 12b and 12c of the piston 12 to move the piston 12 up and down and the main control valve ( 14 is connected to the hydraulic chambers 17, 18, and 19 so that fluid for inverting the movement of the piston 12 can flow into and out of the hydraulic chambers 17, 18, and 19. Referring to the drawing, the piston inversion hydraulic chamber 17 is provided with the main valve 14 for switching the connection between the high pressure part 15a for supplying the high pressure fluid and the low pressure part 15b for the low pressure fluid to flow out. The flow path 17 'is connected to a high pressure or a low pressure therein. In addition, the high pressure chamber 19 is connected to the flow path 19 'connected to the high pressure unit 15a, and the inside thereof is always at a high pressure, and the low pressure chamber 18 is connected to the low pressure unit 15b. ) Is always connected to a low pressure inside. On the other hand, a pilot port 18a is formed between the inlet of the flow path 18 'connected to the low pressure chamber 18 and the inlet of the flow path 19' connected to the high pressure chamber 19, which is formed through the flow path 18a '. It is connected to the signal receiving portion 14d of the main control valve 14. The pilot port 18a is connected to the low pressure chamber 18 or to the high pressure chamber 19 according to the position of the piston 12 reciprocating up and down. That is, the pilot port 18a is connected to the high pressure chamber 19 when the piston 12 is raised, and is connected to the low pressure chamber 18 when the piston 12 is lowered. Accordingly, a low pressure or high pressure fluid is supplied to the signal receiving portion 14d of the main control valve 14 in conjunction with the up and down reciprocating motion of the piston 12. Accordingly, the main control valve 14 is operated to The connection to the high pressure part 15a or the low pressure part 15b of the flow path 17 'connected to the piston inversion hydraulic chamber 17 is switched.

The main control valve 14 is connected to the reciprocating motion of the piston 12 to connect the flow path 17 ′ connected to the piston inversion hydraulic chamber 17 by switching between the high pressure part 15a and the low pressure part 15b. For the purpose, various types of pilot valves are mainly used. The figure conceptually shows the main valve 14 as a symbol. Referring to the drawings, the main control valve 14 is connected to the piston inverted hydraulic chamber 17 in a state in which the main control valve 14 is switched to the first switching position 14a as shown in FIGS. 1A and 1B. 15b), and the flow path 17 'connected to the piston inversion hydraulic chamber 17 is connected to the high pressure part 15a in the state of being switched to the second switching position 14b as shown in FIGS. 1C and 1D. . The switching of the main control valve 14 is performed by inflow and outflow of the low or high pressure fluid into the signal receiving portion 14d connected to the flow path 18a 'according to the position of the piston 12. Referring to the drawings in more detail, the main control valve 14 has a pressurizing portion 14c and the signal receiving portion 14d opposite thereto. The pressurizing portion 14c is a portion which receives the force for maintaining the main control valve 14 in the state of the first switching position 14a. The force is formed by a spring force or a fluid pressure. In the drawing, an embodiment in which the pressurizing portion 14c is connected to the high pressure portion 15a is applied to the pressurizing portion 14c by a high pressure hydraulic pressure. When the piston 12 descends and the low pressure is applied to the signal receiving portion 14d, the main control valve 14 has a magnitude of the force acting on the signal receiving portion 14d by the low pressure. It is set to be smaller than the force acting on the) to maintain the state converted to the first switching position (14a), when the piston 12 is raised and the high pressure is applied to the signal receiving portion (14d) the signal by the high pressure The magnitude of the force acting on the receiving portion 14d is larger than the force acting on the pressing portion 14c and is switched to the second switching position 14b. The operation of the main control valve 14 is simply implemented as a pilot valve in which the signal receiving portion 14d has a hydraulic pressure surface wider than that of the pressing portion 14c. Therefore, since the pilot port 18a to which the signal receiving portion 14d is connected is connected to the low pressure chamber 18 or the high pressure chamber 19 according to the position of the piston 12, the main control valve 14 is connected to the piston. It operates in conjunction with the reciprocating motion of (14) to switch the switching position.

The chisel 13 is hit by the lower end of the piston 12 with the upper end lowered so that the lower end penetrates the crushed object 1 or drills a hole in the crushed object 1. It is housed in the lower inlet 21 of the hole and installed in the lower part of the piston 12. Referring to the drawings, the chisel 13 is moved only within a predetermined range up and down by the chisel pin receiving portion 13a formed on one side is caught by the chisel pin 21a installed on the head portion 11b. The chisel 13 has the lower end of the piston 12 in contact with the to-be-crushed object 1 such as rock, and the piston 12 is lowered and the impact surface 12d of the piston 12 hits the upper end thereof. The crushed object 1 is crushed by the impact force. In addition, the chisel 13 is installed so as to rotate while being hit by the piston 12 to make a hole in the crushed object (1).

The operation of the hydraulic hammer will be described with reference to FIGS. 1A to 1D. FIG. 1A shows the moment when the piston 12 hits the chisel 13 and starts to rise, ie the moment when the piston 12 reaches bottom dead center. Referring to the drawing, since the pilot port 18a is connected to the low pressure chamber 18 and low pressure is applied to the signal receiving portion 14d of the main control valve 14, the main control valve 14 is in the first switching position. Switched to 14a. Accordingly, the piston inversion hydraulic chamber 17 is connected to the low pressure section 15b, the high pressure chamber 19 is connected to the high pressure section 15a, and a high pressure is applied to the high pressure chamber 19, and the piston inversion hydraulic pressure is applied. Low pressure is applied to the seal 17 so that the piston 12 starts to rise.

FIG. 1B shows a state in which the piston 12 is raised. Referring to the drawings, the main control valve 14 maintains the state of the first switching position 14a because the pilot port 18a is closed by the piston 12 during the ascending of the piston 12. Done. Thus, the rise of the piston 12 continues to be maintained. At this time, the gas in the gas chamber 16 is compressed to cushion the rise of the piston 12.

FIG. 1C shows the moment when the ascending of the piston 12 is completed and the piston 12 begins to descend, that is, the moment when the piston 12 reaches top dead center. Referring to the drawings, the piston 12 is raised to the pilot port (18a) is connected to the high pressure chamber 19, the high pressure is applied to the signal receiving portion (14d) of the main control valve 14, the main control valve 14 is switched to the second switching position 14b. Accordingly, the piston inversion hydraulic chamber 17 is connected to the high pressure portion 15a so that high pressure is applied therein. However, since the width of the lower hydraulic pressure surface 12b exposed to the piston inversion hydraulic chamber 17 is larger than the width of the upper hydraulic pressure surface 12c exposed to the high pressure chamber 19, the piston 12 moves downward. It is accelerated by force. At this time, the compressed gas of the gas chamber 16 is expanded to apply pressure to the gas pressure surface 12a of the piston 12 to further accelerate the piston 12.

1D shows a state where the piston 12 is lowered. Referring to the drawings, during the lowering of the piston 12, since the pilot port 18a is closed by the piston 12, the second switching position 14b of the main control valve 14 is continuously maintained. The piston 12 continues to descend.

On the other hand, the piston inverted hydraulic chamber 17 and the high pressure chamber 19 is supplied with a high pressure fluid. In addition, the piston 12 is the moment when the piston 12 is raised to connect the pilot port 18a to the high pressure chamber 19 and the piston 12 is lowered so that the pilot port 18a is the low pressure chamber At the moment of the connection to 18, the piston 12 stops immediately because of the inertia force, and the movement is not reversed, but overshooting is performed to some extent. Therefore, since the high pressure is formed in the piston inversion hydraulic chamber 17 and the high pressure chamber 19 by the inflow of the high pressure fluid and the compression of the fluid by overshooting, the gas chamber (from the piston inversion hydraulic chamber 17) 16 and the fluid leak from the high pressure chamber 19 to the through hole 22 of the head portion 11b. Such leakage may cause serious problems when the work is performed in a high temperature region or when the temperature of the fluid rises due to repetitive work and the viscosity of the fluid drops. In order to prevent such leakage, the cylinder 11a abuts between the piston inversion hydraulic chamber 17 and the gas chamber 16 and between the high pressure chamber 19 and the head portion 11b. Sealing means for sealing between the inner surface and the outer surface of the piston 12 is installed as shown. As described above, since the high pressure is applied to the piston inversion hydraulic chamber 17 and the high pressure chamber 18, seals 23 and 25 suitable for high pressure sealing are provided as the sealing means.

However, since the descending of the piston 12 is accelerated at a high speed by the high pressure oil pressure introduced into the piston inversion hydraulic chamber 17 and the gas pressure of the gas chamber 16, the chisel 13 is lowered like a ball. The piston 12 passes through the inlet of the flow path 19 'connected to the high pressure chamber 19 to block the inlet 19' while the striking surface 12d is at the upper end of the chisel 13. It is overshooted until the surface is hit, and thus the ultra high pressure is instantaneously generated in the high pressure chamber 19. The ultra high pressure is much greater than the fluid pressure flowing from the high pressure section 15a into the high pressure chamber 19. Therefore, a lot of fluid leakage from the high pressure chamber 19 is caused by overshooting during the downward movement of the piston 12. In addition, since the oil leakage from the high pressure chamber 19 has a very high pressure, the seal 25 installed under the high pressure chamber 19 is easily damaged.

The above problem is to form an annular return port 24 on the inner surface of the cylinder (11a) in contact with the outer surface of the piston 12 in the lower portion of the high pressure chamber 19, through the return flow path 24 ' It is eliminated to some extent by connecting to the low pressure part 15b. That is, since the feedback port 24 is connected to the low pressure part 15b, a high pressure instantaneously formed in the high pressure chamber 19 is directly applied to the seal 25 installed below the feedback port 24. You won't lose. In addition, the oil leakage from the high pressure chamber 19 is collected in the return port 24 and returned to the low pressure portion 15b through the return flow passage 24 '.

However, the low pressure part 15b is connected to the main control valve 14 or the pilot port 18a which is rapidly shut off and opened. For example, sudden shutoff and opening of the main control valve 14 generate shock waves having a high peak pressure in the low pressure section 15b. In addition, the peak pressure is transmitted to the feedback port 24 connected to the low pressure part 15b to eventually damage the seal 25 installed below the feedback port 24. That is, in the conventional hydraulic strike device, the seal 25 does not directly receive the leakage pressure from the high pressure chamber 19 due to the formation of the return port 24 connected to the low pressure part 15b. It still has the problem of being easily broken due to the peak pressure of the shock wave transmitted in).

In addition, in the conventional hydraulic hammer, the fluid leaked from the high pressure chamber 19 is returned to the low pressure part 15b, but the fluid leaked from the high pressure chamber 19 to the low pressure part 15b is still powered. It has the disadvantage of being lost.

The present invention is to solve the above problems, an object of the present invention is to provide a shock wave generated in the low pressure portion by installing a check valve in the return flow path connecting the return port and the low pressure returning fluid leaked from the high pressure chamber It is to provide a hydraulic impact device that can prevent the damage of the seal installed in the lower portion of the return port by preventing the peak pressure due to the return port.

In addition, another object of the present invention is to form a new return port connected to the high-pressure section between the high-pressure chamber and the return port and install a seal between the return port and the new return port leakage leakage from the high-pressure chamber to the low pressure section is a power loss It is to provide a hydraulic hammer to reduce the.

In order to achieve the above object, the hydraulic striking device according to the present invention includes a cylinder, a gas chamber formed in an upper portion of the cylinder and filled with a compressed gas therein, and a through hole coaxial with the cylinder in the lower portion of the cylinder. A head having a head portion formed therein, an upper end portion accommodated in the gas chamber, and a lower end portion accommodated in the through-hole of the head portion, the piston being installed to reciprocate up and down inside the cylinder, and a plurality of hydraulic pressures formed by the cylinder and the piston. A plurality of passages connected to the hydraulic chamber so that the seal, the fluid for moving the piston up and down into the hydraulic chamber, and all or part of the passage connected to the hydraulic chamber in conjunction with the reciprocating motion of the piston, the low pressure portion and the high pressure portion Main valve for switching and connecting each other, and lower part of the lowered piston The upper end is accommodated in the through hole of the head so that the lower end impacts the crushed object, and the chisel installed in the lower part of the piston is connected to the low pressure part through the first return flow path and the outer surface of the piston at the lower part of the high pressure chamber. A hydraulic strike device comprising a first return port formed in an annular shape on an inner surface of the cylinder in contact with a cylinder, and a plurality of first seals provided below the first return port, wherein the hydraulic strike device is provided on the first return flow path, And a first check valve opening when the pressure at the first return port of the fluid leaking from the seal is higher than the pressure at the low pressure portion.

The first check valve is opened only when the pressure acting on the first return port is higher than the fluid pressure of the low pressure section by the fluid leaked from the high pressure chamber to the first return port. Accordingly, the fluid leaked from the high pressure chamber to the first return port is returned to the low pressure portion from the first return port, and the pressure of the first return port drops so that the first seal directly receives the high pressure formed in the high pressure chamber. You will not receive it. In addition, since the peak pressure due to the shock wave generated by the sudden opening and closing of the main control valve or the pilot port and transmitted through the flow path to which the low pressure part is connected is greater than the pressure at the first precious port, the first check valve is kept closed. . Accordingly, the peak pressure is not directly transmitted from the low pressure portion to the first seal through the first return port.

In addition, the hydraulic striking device according to the present invention, the first check valve is installed on the first return flow path so that each of the inlet on both sides of the low pressure portion and the first return port, the first return port A poppet cylinder in which a sheet is formed at an inlet leading to the sheet, a sheet portion is formed at one end thereof, a poppet installed inside the poppet cylinder to allow the sheet portion to reciprocate against the sheet, and the sheet portion is in close contact with the sheet In order to apply elasticity to the poppet, one end is supported by the poppet and the other end is characterized in that the poppet valve including a spring supported on the inner surface of the poppet cylinder.

The poppet valve is easily installed inside the body of the hydraulic hammer, and operates stably without being damaged even when a strong impact is applied to the body.

In addition, the hydraulic strike device according to the present invention, the second return port is connected to the high pressure portion through the second return flow path, and formed in an annular shape on the inner surface of the cylinder in contact with the outer surface of the piston between the high pressure chamber and the first return port. A second check valve installed on the second return flow path and opened when the pressure at the second return port of the fluid leaking from the high pressure chamber is higher than the pressure of the high pressure section; and the second return port. And a second seal installed between the first return port.

Since the first return port and the second return port are sequentially connected to the high pressure part and the low pressure part, the oil leakage from the high pressure chamber is sequentially reduced and returned to the high pressure part and the low pressure part. On the other hand, since a second seal is installed between the first return port and the second return port, the fluid leaked from the high pressure chamber is mostly returned to the high pressure part through the second return port and the second return flow path. However, unlike the fluid returned to the low pressure part, the fluid returned to the high pressure part consumes less power to increase the pressure. In particular, since the second return port is connected to the high pressure part, the pressure difference between the second return port and the first return port is a pressure difference corresponding to the pressure difference between the high pressure part and the low pressure part. Therefore, the risk of damage is significantly reduced because the second seal provided between the first return port and the second return port is not subjected to the ultra high pressure generated instantaneously in the high pressure chamber and is subjected to the pressure according to the general use conditions. .

In addition, in the hydraulic striking device according to the present invention, the second check valve is installed on the second return flow path such that each of the inlets at both sides thereof leads to the second return port and the high pressure part, and the second return port is A poppet cylinder in which a sheet is formed at a subsequent inlet, a sheet portion is formed at one end thereof, a poppet installed inside the poppet cylinder to allow the sheet portion to reciprocate against the sheet, and the sheet portion is in close contact with the sheet. In order to apply elasticity to the poppet, one end is supported by the poppet, and the other end is a poppet valve including a spring supported on the inner surface of the poppet cylinder.

The poppet valve is easily installed inside the body of the hydraulic hammer, and operates stably without being damaged even when a strong impact is applied to the body.

Hereinafter, with reference to the embodiment shown in the drawings will be described in detail the hydraulic hammer according to the present invention.

2 is a cross-sectional view showing a hydraulic hammer according to an embodiment of the present invention.

Referring to the drawings, the hydraulic hammer according to the present invention includes all or part of the configuration of the conventional hydraulic hammer. That is, the hydraulic striking device according to the present invention includes a cylinder 11a, a gas chamber 16 formed at an upper portion of the cylinder 11a and filled with a compressed gas therein, and a lower portion of the cylinder 11a. The head portion 11b formed to have the through holes 21 and 22 coaxial with 11a, and the upper end portion is accommodated in the gas chamber 16 and the lower end portion is accommodated in the through hole 22 of the head portion 11b. The piston 12 is provided to allow the reciprocating movement up and down inside the cylinder 11a, and the cylinder 11a and the piston have at least a piston inversion hydraulic chamber 17 and a lower high pressure chamber 19. A plurality of hydraulic chambers 17, 18, 19 and a fluid that pressurizes the hydraulic pressure surfaces 12b, 12c of the piston to move the piston 12 up and down are provided in the hydraulic chambers 17, 18, 19. A plurality of flow paths 17 ', 18', 18a ', 19' connected to each of the hydraulic chambers 17, 18, 19 so as to flow in and out of the A main control valve 14 for connecting the flow path 17 'connected to the piston inversion hydraulic chamber 17 to the lower pressure part 15b and the high pressure part 15a in conjunction with the copper, and a piston having an upper end lowered ( The upper end is accommodated in the through hole 21 of the head portion 11b so that the lower end of the 11a) is struck by the lower end of the piston 11a so as to be crushed by the lower end of the piston 11a. And, they are similar in structure to the conventional hydraulic striker described above. Therefore, hereinafter, only features of the present invention will be described in detail.

The present invention is characterized in that it further comprises a first check valve (30) installed on the first return passage (24 '). The first check valve 30 is opened only when the pressure acting on the first return port 24 is higher than the pressure of the low pressure part 15b due to the fluid leaked from the high pressure chamber 19. Accordingly, the leakage oil is returned from the first return port 24 to the low pressure portion 15b. That is, the first check valve 30 is leaked when the pressure acting on the first return port 24 by the fluid leaked from the high pressure chamber 19 is higher than the fluid pressure of the low pressure section 15b. Is opened to return to the low pressure portion 15b from the first return port 24, but is generated in the low pressure portion 15b by opening and closing the main control valve 14 or the pilot port 18a, When the pressure is higher than the pressure at the first return port 24, the peak pressure is passed through the flow path 24 ′ connected to the low pressure portion 15b and the first return port 24 to the first seal 25. Is closed so that it is not delivered. Accordingly, high pressure is not applied to the first seal 25 so that the risk of damage to the first seal 25 is reduced.

On the other hand, in general, since the hydraulic strike device is subjected to a strong impact, it is desirable to ensure strong durability. In addition, the configuration formed or installed in the hydraulic hammer is preferably formed or installed in the body (11). For this purpose, FIG. 3 illustrates an embodiment in which a poppet valve is used as the check valve 30.

Referring to the drawings, the poppet valve includes a poppet cylinder 31, a poppet 32, and a spring 33.

The poppet cylinder 31 is installed on the first return passage 24 ′ so that each of the inlets at both sides thereof leads to the low pressure part 15b and the first return port 24, respectively, and the first return port ( A sheet 31a is formed at the inlet which leads to 24.

The poppet 32 has a sheet portion 32a formed at one end thereof, and is installed inside the poppet cylinder so that the sheet portion 32a can reciprocate against the sheet 31a. In the drawing, the poppet 32 has an outer surface in close contact with the inner surface of the poppet cylinder 31, and a hole 34 for communicating between one end of the seat portion 32a and the other end of which the one end of the spring 33 is supported. Although an embodiment in which the) is formed is shown, the present invention is not limited thereto. That is, the hole 34 is for forming the flow path in which the fluid flows from the one side inlet of the seat part 32a to the other inlet, which is the poppet cylinder 31 and the poppet ( It may be formed between the contact surface of the 32, or may be formed on the wall surface of the poppet cylinder 31, as well as by a gap between the outer surface of the poppet 32 and the inner surface of the poppet cylinder 31. .

The spring 33 has one end supported by the poppet 32 in order to apply elasticity to the poppet 31 in the direction in which the seat 32a is in close contact with the seat 31a, and the other end of the spring 33 15b) is supported on the inner surface of the poppet cylinder 31 on the inlet side. The spring 33 has a pressure applied to the first return port 24 by the fluid leaked from the high-pressure chamber 19 is greater than a fluid pressure of the low pressure portion 15b by a predetermined pressure difference to the pressure difference. When the force applied to the poppet 32 is greater than the spring force of the spring 33 is compressed, the sheet portion 32a is separated from the sheet 31a. Accordingly, the poppet valve is opened.

In addition, the present invention is characterized in that it further comprises a second return port 26, the second check valve 40, and the second seal (27).

The second return port 26 is connected to the high pressure part 15a through a second return flow path 26 ', and between the high pressure chamber 19 and the first return port 24 of the piston 12. The inner surface of the cylinder (11a) in contact with the outer surface is formed in an annular shape.

The second check valve 40 is opened when the pressure acting on the second return port 26 by the fluid leaked from the high pressure chamber 19 is higher than the pressure of the high pressure section 15a so that the leaked oil is discharged. It is provided on the second feedback flow path 26 'so as to be returned from the two feedback ports 26 to the high pressure portion 15a. The check valve 40 is closed when the pressure of the leaked oil drops and the pressure of the high pressure part 15a becomes greater than the pressure at the second return port 26. Therefore, the fluid flows back from the high pressure part 15a and the It does not leak to one return port 24.

The second seal 27 is for preventing leakage from the second return port 26 to the first return port 24. The second return port 26 and the first return port 24 are prevented from leaking. It is installed between. The seal will break well under high pressure. However, when the leakage pressure is higher in the second return port 26 than in the high pressure part 15a, the check valve 40 is opened, so that the second return port 26 is slightly lower than the pressure of the high pressure part 15a. High pressure is applied. Therefore, a pressure difference corresponding to the pressure difference between the high pressure part 15a and the low pressure part 15b is generated between the second return port 26 and the first return port 24. That is, in the case of a vacancy, the pressure acting on the second return port 26 due to the fluid leaking from the high pressure chamber 19 due to the ultra-high pressure generated instantaneously in the high pressure chamber 19 is the first pressure. By opening the two check valve 40, the second return port 26 is stepped down to a pressure slightly higher than the pressure of the fluid acting on the high pressure section 15a. Therefore, since a general pressure condition is formed between the second return port 26 and the first return port 24, a second seal 27 can be installed, and the second seal 27 is a low pressure part. Do not allow leakage to be returned to (15b). In addition, since the second check valve 40 blocks the flow of the fluid from the high pressure section 15a to the second return port 26, the high pressure of the high pressure section 15a and the main control valve 14 and the pilot port. The peak pressure due to the shock wave generated in the high pressure section 15a by the blocking of 18a is not transmitted to the second seal.

On the other hand, the present invention is characterized in that the poppet valve is used as the second check valve 40, which is similar to the reason for using the poppet valve as the first check valve (30).

Referring to the drawings, the second check valve 40 is a poppet valve, and the inlet on each side of the second return passage 26 ′ is connected to the second return port 26 and the high pressure part 15a. And a poppet cylinder 41 having a sheet 41a formed at an inlet leading to the second return port 26, and a sheet portion 42a formed at one end thereof, and the sheet portion 42a being the sheet ( A popping force in the poppet 41 in a direction in which the poppet 42 installed inside the poppet cylinder 41 and the sheet portion 42a are in close contact with the sheet 41a to enable reciprocating movement to face 42b). In order to apply, one end is supported by the poppet 42 and the other end includes a spring 43 supported on the inner surface of the poppet cylinder 41 at the inlet side connected to the high pressure part 15a. In the drawing, the outer surface of the poppet 42 is in close contact with the inner surface of the poppet cylinder 41 and the hole 44 for communicating between the one end portion formed with the seat portion 42a and the other end portion where the one end portion of the spring 43 is supported. Although the embodiment shown in FIG. 1 is illustrated, the present invention is not limited thereto as in the first check valve.

By the above configuration, the hydraulic striking device according to the present invention prevents the peak pressure due to the shock wave from being transmitted to the first return port by installing a check valve in the first return flow path connecting the first return port and the low pressure part. It has an advantage of preventing damage to the seal installed below the first precious port.

In addition, the hydraulic striking device according to the present invention forms a new second return port connected to the high-pressure section between the high-pressure chamber and the first return port and install a seal between the first return port and the new second return port. Not only can the power loss be reduced by reducing the leakage oil returned to the low pressure portion, but the peak pressure due to the high pressure and the shock wave of the high pressure portion is not transmitted to the seal, which has the advantage of preventing damage to the seal.

An embodiment of the present invention described above and illustrated in the drawings should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention as long as it will be apparent to those skilled in the art.

Claims (4)

A head, a gas chamber formed at an upper portion of the cylinder and filled with a compressed gas therein; a head portion formed to have a through hole coaxial with the cylinder at a lower portion of the cylinder; an upper end portion is accommodated in the gas chamber; A piston accommodated in the through hole and installed in the cylinder to reciprocate up and down, a plurality of hydraulic chambers formed by the cylinder and the piston, and a fluid for moving the piston up and down to the hydraulic chamber; A plurality of flow paths connected to the hydraulic chamber, a main control valve for connecting all or a part of the flow paths connected to the hydraulic chamber by interworking with the reciprocating motion of the piston to switch between the low pressure part and the high pressure part, and the lower end of the piston having the upper end lowered. Is hit by the upper end so that the lower end impacts the crushed object. A chisel installed in the through hole of the rod and connected to the low pressure portion through a first return flow path, and having a first return port formed in an annular shape on the inner surface of the cylinder which is in contact with the outer surface of the piston in the lower portion of the high pressure chamber; In the hydraulic strike device including a plurality of first seals provided below the first return port, And a first check valve installed on the first return flow path and opened when the pressure at the first return port of the fluid leaking from the high pressure chamber is higher than the pressure of the low pressure part. Strike device. The method of claim 1, The first check valve may include: a poppet cylinder having a seat formed at the inlet leading to the first return port and installed on the first return flow path such that both inlets respectively lead to the low pressure part and the first return port; A sheet portion formed at one end thereof and a poppet installed inside the poppet cylinder such that the sheet portion can reciprocate against the sheet; And a poppet valve having one end supported by the poppet and the other end supported by an inner surface of the poppet cylinder in order to apply elasticity to the poppet in a direction in which the seat portion is in close contact with the seat. The method according to claim 1 or 2, A second return port connected to the high pressure part through a second return flow path and formed in an annular shape on an inner surface of the cylinder which is in contact with the outer surface of the piston between the high pressure chamber and the first return port; A second check valve installed on the second return flow path and opened when the pressure at the second return port of the fluid leaking from the high pressure chamber is higher than the pressure of the high pressure part; And a second seal provided between the second return port and the first return port. The method of claim 3, The second check valve may include: a poppet cylinder having a seat formed at the inlet connected to the second return port so that both inlets respectively lead to the second return port and the high pressure part; A sheet portion formed at one end thereof and a poppet installed inside the poppet cylinder to allow the sheet portion to reciprocate against the sheet; And a poppet valve having one end supported by the poppet and the other end supported by an inner surface of the poppet cylinder in order to apply elasticity to the poppet in a direction in which the seat portion is in close contact with the seat.

Images