KR100985814B1

KR100985814B1 - That cavitation prevention equipment is equipped double pilot check valve

Info

Publication number: KR100985814B1
Application number: KR1020100014580A
Authority: KR
Inventors: 이재훈
Original assignee: 파카코리아 주식회사
Priority date: 2010-02-18
Filing date: 2010-02-18
Publication date: 2010-10-08

Abstract

The present invention relates to a double pilot check valve provided with a cavitation prevention device, comprising: a valve body; First and second poppet valves coupled to both sides of the main passage of the valve body; It is coupled to slide inside the main passage of the valve body, and opens and closes the first poppet valve or the second poppet valve while reciprocating along the main passage, and the cylinder having a free-falling structure is lowered by its own weight, so that the first port and the first When the oil pressure in the two ports temporarily drops, a piston is provided to supply the oil of the high pressure third and fourth port sides to the low pressure first and second port sides.
Therefore, even if the cylinder having the free-falling structure is lowered by its own weight, the first port and the second port maintain a high pressure, so that the piston is smoothly operated, thereby preventing the second poppet valve from being temporarily opened. Oil flows smoothly and continuously. Therefore, the present invention not only prevents the chattering and hunting phenomenon, which is a conventional problem, but also improves the operation speed of the doser blade and greatly reduces noise.

Description

That cavitation prevention equipment is equipped double pilot check valve}

The present invention relates to a double pilot check valve connected to an excavator dozer blade cylinder, and more particularly to a double pilot check valve equipped with a cavitation prevention device.

The double pilot check valve is installed to be connected to the cylinder for the dozer blade for excavator to prevent the cylinder from falling without manipulation.

In the double pilot check valve, a main control valve is connected to the first and fourth ports on the upper side of the valve body, and a dozer blade cylinder is connected to the second and third ports on the lower side of the valve body.

The main passage inside the valve body is installed to reciprocate the piston, and both sides of the valve body are provided with a first poppet valve and a second poppet valve to open and close sequentially when the piston is reciprocated.

In the conventional double pilot check valve, the hydraulic pressure flows into the first port and then is supplied to the third port through the second port, and the hydraulic pressure supplied to the third port is discharged to the fourth port, and the hydraulic pressure is thus routed. Flows to the dozer blade cylinder.

That is, high pressure is formed on one side of the main passage of the valve body while oil is supplied from the first port to the second port. The piston pushes the other side of the main passage by the high pressure, and the piston pushed to the other side of the main passage is Operate the second poppet valve to connect the third and fourth ports. Therefore, the high pressure hydraulic pressure in the first port and the second port is discharged to the fourth port through the third port.

However, the dozer blade cylinder is lowered by its own weight because it is installed vertically. When the dozer blade cylinder is lowered by its own weight, the high pressure existing in the first port and the second port is temporarily released by the lowering of the cylinder, and accordingly, the piston cannot be maintained at a high pressure on one side of the main passage. It cannot be pushed to the other side of the main passage, and as a result, the piston cannot operate the second poppet valve.

On the other hand, if the oil continues to be supplied through the first port even after the cylinder has been lowered by its own weight, the high pressure is immediately maintained in the first and second ports, and thus the piston is pushed to the other side of the main passage to open the second poppet valve. The oil in the first and second ports is circulated through the third and fourth ports.

The conventional double pilot check valve has a problem that the oil in the first port and the second port does not flow to the third port and the fourth port instantaneously because the second check valve part is not temporarily opened as the cylinder is lowered by its own weight. In this way, the flow of the oil is not smoothly instantaneously chattering (hunting) and hunting (hunting) phenomenon occurs. Such a problem causes the operation speed of the doser blade to decrease and the noise.

An object of the present invention for solving the above problems is to provide a double pilot check valve equipped with a cavitation prevention device to smoothly flow the oil even if the dozer blade cylinder is lowered by its own weight.

Double pilot check valve provided with a cavitation prevention device of the present invention for achieving the above object, the main passage is formed so as to pass through the inner center, the external oil is introduced to one side of the main passage to be discharged to one side. A valve body having a first port and a second port and having a third port and a fourth port formed so that oil passing through the first port and the second port on the other side flows into the other side of the main passage; A first poppet valve coupled to one side of the main passage of the valve body to open and close the first port and the second port; A second poppet valve coupled to the other main passage of the valve body to open and close the third and fourth ports; It is coupled to slide inside the main passage of the valve body, and opens and closes the first poppet valve or the second poppet valve while reciprocating along the main passage, and the cylinder having a free-falling structure is lowered by its own weight, so that the first port and the first And a piston for supplying oil of the high pressure third port and the fourth port side to the low pressure first port and the second port side when the oil pressure in the two ports temporarily drops.

Another feature of the double pilot check valve provided with a cavitation prevention device of the present invention, the piston, the outer peripheral surface is in close contact with the main passage slides along this, the female thread is formed on the inner peripheral surface and the first poppet valve to open and close the first poppet valve on one side A first piston having a first oil passage formed thereon so that the pressurizing portion protrudes and spaces on both sides of the main passage is formed, and a male screw portion is formed on the outer circumferential surface so as to be fastened to the female screw portion of the first piston, and a second side opposite to the first pressing portion. A second piston having a second pressure part protruding to open and close the poppet valve, a second oil passage formed to connect the other side space of the main passage to the first oil passage, and an opening and closing stepper formed at an inner circumference of the inner space; It is coupled to slide in the inner space of the second piston, and the oil passage is formed so that the first oil passage and the second oil passage are connected. A regeneration poppet having a tapered surface for attaching and detaching the opening and closing end of the second piston and clamping the second oil passage around one side thereof, and one end supported by the regeneration poppet and the other end supported by the first piston, thereby tapering the regeneration poppet. Compression coil spring for elastically supporting the surface on the opening and closing step.

Another feature of the double pilot check valve with a cavitation prevention device of the present invention, the piston, the outer peripheral surface is in close contact with the main passage slides along this, the female threaded portion is formed on the inner peripheral surface and the first poppet valve to open and close the first side The first piston has a first oil passage formed therein so that the first pressing portion protrudes and connects the spaces on both sides of the main passage, and a male screw portion is formed on the outer circumferential surface to be fastened to the female screw portion of the first piston. 2nd piston which protrudes the 2nd pressure part to open / close the poppet valve, the 2nd oil path is formed so that the other side space and the 1st oil path of the main passage may be connected, and the opening and closing step is formed in the inner periphery of the inner space. And a spherical shape provided in the inner space of the second piston and circumscribing the second oil passage while one side circumference is detached from the opening and closing step of the second piston. The regeneration check ball and a compression coil spring having one end supported by the regeneration check ball and the other end supported by the first piston to elastically support the regeneration check ball to the opening and closing end jaw.

Double pilot check valve provided with a cavitation prevention device of the present invention for achieving the same object as described above, the main passage is formed so as to pass through the inner center, so that the external oil flows into one side of the main passage on one side to be discharged A first port and a second port are formed, and the third port and the fourth port are formed so that the oil passing through the first port and the second port on the other side flows into the other side of the main passage and then discharges. A valve body having a connection port formed such that oil in the port is supplied to the first port side; A first poppet valve coupled to one side of the main passage of the valve body to open and close the first port and the second port; A second poppet valve coupled to the other main passage of the valve body to open and close the third and fourth ports; A piston which is coupled to slide in the main passage of the valve body and opens and closes the first poppet valve or the second poppet valve while reciprocating along the main passage; It is installed on one side of the connection port of the valve body to intercept the flow of oil supplied from the connection port to the first port, and the cylinder with the free-falling structure is lowered by its own weight, so the oil pressure inside the first and second ports is temporarily When the fall to the high pressure of the fourth port side oil regeneration poppet for supplying to the low pressure first port side; is provided.

Another feature of the double pilot check valve provided with a cavitation prevention device of the present invention, the regeneration poppet unit is coupled to slide in the valve body and the oil passage is supplied so that the oil is supplied to one side of the main passage through the first port It is formed and is connected to the valve body and the regeneration poppet formed with a tapered surface to remove the flow of oil supplied from the connecting port to the first port side while being detached around the connection port on one side, and prevents the separation of the regeneration poppet A spring pressure adjusting bolt for adjusting the spring pressure, and one end is supported by the regeneration poppet and the other end is supported by the spring pressure adjusting bolt so that the tapered surface of the regeneration poppet is elastically supported around the connection port.

Double pilot check valve provided with a cavitation prevention device of the present invention for achieving the same object as described above, the main passage is formed so as to pass through the inner center, so that the external oil flows into one side of the main passage on one side to be discharged A valve body having a first port and a second port and having a third port and a fourth port formed so that oil passing through the first port and the second port on the other side flows into the other side of the main passage; A first poppet valve coupled to one side of the main passage of the valve body to open and close the first port and the second port; A second poppet valve coupled to the other main passage of the valve body to open and close the third and fourth ports; A piston which is coupled to slide in the main passage of the valve body and opens and closes the first poppet valve or the second poppet valve while reciprocating along the main passage; It is coupled to the valve body so as to be connected to the first port and the fourth port, and the cylinder having the free-falling structure is lowered by its own weight so that the oil pressure inside the first port and the second port temporarily drops to the fourth port side Regeneration poppet assembly for supplying the oil to the first port side of the low pressure; characterized in that it is provided.

Another feature of the double pilot check valve provided with a cavitation prevention device of the present invention is that the regeneration poppet assembly has a first auxiliary port connected to the first port of the valve body so that external oil is supplied to the first port side. A second auxiliary port is formed to be connected to the fourth port of the valve body so that the oil passing through the first to fourth ports is formed. It is formed so that the assembly body is coupled to the inside of the assembly body slides, and the oil passage is formed so that the oil passes through the first auxiliary port to the first port of the valve body, and around one side of the auxiliary connection port A regeneration poppet having a tapered surface for detaching and removing a flow of oil supplied from the auxiliary connection port to the first auxiliary port, and an assembly body The spring pressure adjustment bolt is coupled to prevent the separation of the regeneration poppet and adjusts the spring pressure, and one end is supported by the regeneration poppet and the other end is supported by the spring pressure adjustment bolt so that the tapered surface of the regeneration poppet is elastic around the auxiliary connection port Compression coil spring to be supported by.

According to the present invention as described above, when the cylinder for the dozer blade is lowered by its own weight and the hydraulic pressure of the first port and the second port decreases momentarily, the high pressure oil in the third port and the fourth port is After operating the regeneration poppet by flowing into the second oil passage, it is supplied to the first oil passage of the first piston through the oil passage of the regeneration poppet, and the high pressure oil supplied to the first oil passage is the first port and the second port. While maintaining the high pressure in the first port and the second port while being filled in, the piston is pushed to the third port and the fourth port by the high pressure of the filled high pressure to open the second poppet valve. Therefore, even if the dozer blade cylinder is lowered by its own weight, the first port and the second port maintain a high pressure, and thus the piston is smoothly operated. Accordingly, the second poppet valve is prevented from being opened temporarily. The flow is continuous smoothly. Therefore, the present invention not only prevents the chattering and hunting phenomenon, which is a conventional problem, but also improves the operation speed of the doser blade and greatly reduces noise.

Figure 1 is a schematic cross-sectional view showing a double pilot check valve with a cavitation prevention device of the present invention
2 is a circuit diagram of FIG.
3 is a schematic cross-sectional view showing a state in which a regeneration check ball is built into a piston;
4 is a schematic cross-sectional view showing a state in which a regeneration poppet unit is built in a valve body;
Figure 5 is a schematic cross-sectional view showing a state in which the regeneration poppet assembly is coupled to one side of the valve body
6 is a circuit diagram of FIG.

Specific features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.

1 is a schematic cross-sectional view showing a double pilot check valve with a cavitation prevention device of the present invention, Figure 2 is a circuit diagram of Figure 1, the double pilot check valve of the present invention, the valve body 10, the first poppet The valve 20, the second poppet valve 40, and the piston 60 are formed.

The valve body 10 has a main passage 11 formed to penetrate the inner center, and the first port 13 and the second port so that external oil flows into one side of the main passage 11 at one side thereof and then discharged. 14 and the third port 15 and the fourth so that the oil passing through the first port 13 and the second port 14 on the other side flows into the other side of the main passage 11 and then discharged. The port 16 is formed. The female threaded portion 12 is coupled to both sides of the main passage 11 so that the first poppet guide 21 of the first poppet valve 20 and the second poppet guide 41 of the second poppet valve 40 are coupled to each other. Formed.

The main control valve (not shown) is connected to the first port 13 and the fourth port 16 on the upper side of the valve body 10, and the second port 14 and the third on the lower side of the valve body 10. The port 15 is connected to a cylinder for a dozer blade (not shown).

The first poppet valve 20 is coupled to one side of the main passage 11 of the valve body 10 to open and close the first port 13 and the second port 14. The first poppet valve 20 includes a first poppet guide 21, a first poppet 26, a first spring pressure adjusting bolt 30, and a first compression coil spring 31.

The first poppet guide 21 has a first male screw portion 22 formed around the female body 12 of the valve body 10 so that the first poppet 26 slides in the center thereof. The guide hole 23 is formed, and the first female screw portion 24 is formed at the inlet of the first guide hole 23 so that the first spring pressure adjusting bolt 30 is engaged. A first oil hole 25 is formed at one end of the first poppet guide 21, and oil introduced into the first port 13 by the first oil hole 25 flows into the main passage 11. After entering, it is supplied to the second port 14 through the first oil hole 25.

The first poppet 26 is inserted into the first guide hole 23 of the first poppet guide 21 and is formed to slide along the first guide portion 27. The first pressing part 28 is formed at one side to contact the first pressing part 63 of the first piston 61, and between the first guide part 27 and the first pressing part 28. The first tapered surface 29 is formed to be detached around the first guide hole 23 of the poppet guide 21 to interrupt the flow of oil between the main passage 11 and the first oil hole 25. have.

The first spring pressure adjusting bolt 30 is fastened to the first female threaded portion 24 of the first poppet guide 21 to prevent separation of the first poppet 26 and to adjust the spring pressure.

One end of the first compression coil spring 31 is supported by the first poppet 26 and the other end is supported by the first spring pressure adjusting bolt 30 so that the first tapered surface 29 of the first poppet 26 is The first poppet guide 21 is elastically supported around the first guide hole 23.

The second poppet valve 40 is coupled to the other side of the main passage 11 of the valve body 10 to open and close the third port 15 and the fourth port 16. The second poppet valve 40 includes a second poppet guide 41, a second poppet 46, a second spring pressure adjusting bolt 50, and a second compression coil spring 51.

The second poppet guide 41 has a second male thread portion 42 formed therein so as to be fastened to the female threaded portion 12 of the valve body 10, and the second poppet 46 slides in the center thereof. A guide hole 43 is formed, and a second female threaded portion 44 is formed at an inlet of the second guide hole 43 to fasten the second spring pressure adjusting bolt 50. A second oil hole 45 is formed at one end of the second poppet guide 41, and oil introduced into the third port 15 by the second oil hole 45 flows into the main passage 11. Then, it is supplied to the fourth port 16 through the second oil hole 45.

The second poppet 46 is inserted into the second guide hole 43 of the second poppet guide 41 so as to slide along the second guide portion 47, and the second guide portion 47 A second pressing portion 48 is formed at one side to contact the second pressing portion 67 of the second piston 65, and between the second guide portion 47 and the second pressing portion 48. The second tapered surface 49 is formed to be detached around the second guide hole 43 of the poppet guide 41 to control the flow of oil between the main passage 11 and the second oil hole 45. have.

The second spring pressure adjusting bolt 50 is fastened to the second female threaded portion 44 of the second poppet guide 41 to prevent separation of the second poppet 46 and to adjust the spring pressure.

One end of the second compression coil spring 51 is supported by the second poppet 46 and the other end is supported by the second spring pressure adjusting bolt 50 so that the second tapered surface 49 of the second poppet 46 is formed. The second poppet guide 41 is elastically supported around the second guide hole 43.

The piston 60 is coupled to slide in the main passage 11 of the valve body 10, and is reciprocated along the main passage 11 while the first poppet valve 20 or the second poppet valve 40 is moved. Open and close When the cylinder for the dozer blade is lowered by its own weight and the oil pressure in the first port 13 and the second port 14 drops temporarily, the piston 60 has a high-pressure third port 15 and a fourth port. The oil on the (16) side is supplied to the low pressure first port 13 and the second port 14 side.

The piston 60 is composed of a first piston 61, a second piston 65, a regeneration poppet 71, a compression coil spring (74).

The first piston 61, the outer peripheral surface is in close contact with the main passage 11 and slides along the female threaded portion 62 is formed on the inner peripheral surface, the first pressing portion to open and close the first poppet valve 20 on one side 63 protrudes. The first oil passage 64 is formed in the first piston 61 so that spaces on both sides of the main passage 11 are connected to each other.

The second piston 65 has a male thread portion 66 formed on an outer circumferential surface of the second piston 65 so as to be fastened to the female threaded portion 62 of the first piston 61, and a second poppet valve on the opposite side of the first pressure portion 63. The second pressing portion 67 protrudes so as to open and close 40. The second piston 65 has a second oil passage 69 formed so that the other side space of the main passage 11 and the first oil passage 64 are connected, and the opening and closing end is formed around the inner circumference of the inner space 68. The jaw 70 is formed.

The regeneration poppet 71 is coupled to slide in the inner space 68 of the second piston 65, and the oil passage 72 is connected so that the first oil passage 64 and the second oil passage 69 are connected. Formed. One side circumference of the regeneration poppet 71 is provided with a tapered surface 73 for attaching and detaching the opening and closing step 70 of the second piston 65 to control the second oil passage 69.

One end of the compression coil spring 74 is supported by the regeneration poppet 71 and the other end is supported by the first piston 61 so that the tapered surface 73 of the regeneration poppet 71 is elastic to the opening and closing step 70. Support.

The double pilot check valve equipped with the cavitation prevention device of the present invention having such a configuration has a high pressure oil flowing into the first passage 13 and then into one side of the main passage 11 of the valve body 10. As the high pressure is formed, as the first compression coil spring 31 of the first poppet valve 20 is compressed, the first poppet 26 is pushed down, and the main passage 11 is connected to the second port 14 so that Oil is supplied to the second port (14).

When oil is supplied to the first port 13 so that the high pressure oil is filled in the first port 13 and the second port 14, the piston 60 is pushed toward the second poppet valve 40. While the second poppet 46 of the two poppet valves 40 is pressed by the second pressing part of the second piston 65, the third port 15 and the fourth port 16 are connected to the other side of the main passage 11. Connected.

Therefore, the oil supplied to the first port 13 is supplied to the second port 14 through the one side space of the main passage 11 and the second port 14 is a separate line (not shown) to the third port 15. Since the oil is connected to the second port 14, the oil supplied from the second port 14 is supplied to the third port 15. The oil supplied to the third port 15 is introduced into the other space of the main passage 11 and then discharged to the fourth port 16, and the hydraulic pressure flows in such a path to operate the dozer blade cylinder.

The high pressure is formed at one side of the main passage 11 of the valve body 10 while the high pressure oil is supplied from the first port 13 to the second port 14, and the piston 60 is formed by the high pressure. The piston 60 pushed to the other side of the main passage 11 and pushed to the other side of the main passage 11 operates the second poppet valve 40 to open the third port 15 and the fourth port 16. Connect Therefore, the high pressure hydraulic pressure in the first port 13 and the second port 14 is discharged to the fourth port 16 through the third port 15.

On the other hand, the dozer blade cylinder (not shown) is lowered by its own weight because it is installed vertically. When the dozer blade cylinder is lowered by its own weight, the high pressure existing in the first port 13 and the second port 14 is temporarily released by the lowering of the cylinder, and thus the high pressure is applied to one side of the main passage 11. This is not maintained momentarily.

As described above, when the cylinder for the dozer blade is lowered by its own weight and the hydraulic pressure of the first port 13 and the second port 14 decreases momentarily, the first port 13 and the second port around the piston 60 A pressure difference is generated between one space of the main passage 11 to which the port 14 is connected, and the other space of the main passage 11 to which the third port 15 and the fourth port 16 are connected.

Due to this pressure difference, the high pressure oil on the other side of the main passage 11 is moved to one side of the main passage 11, so that the high pressure oil of the third port 15 and the fourth port 16 is transferred to the second piston. The first oil passage 64 of the first piston 61 is introduced into the second oil passage 69 of 65 to operate the regeneration poppet 71 and then through the oil passage 72 of the regeneration poppet 71. Is supplied. The high pressure oil supplied to the first oil passage 64 is filled in the first port 13 and the second port 14 while maintaining the high pressure in the first port 13 and the second port 14.

As such, although the low pressure is instantaneously formed in the first port 13 and the second port 14 due to the drop of the cylinder's own weight, the third port 15 and the fourth port ( The high pressure oil on the 16) side is immediately filled to the first port 13 and the second port 14 side, and high pressure is formed in the first port 13 and the second port 14.

As described above, as the high pressure is formed in the first port 13 and the second port 14 by the operation of the regeneration poppet 71 and the oil is supplied from the first port 13, the piston 60 The second poppet valve 40 is opened while being pushed toward the third port 15 and the fourth port 16.

Therefore, even if the dozer blade cylinder is lowered by its own weight, the first port 13 and the second port 14 maintain high pressure, so that the operation of the piston 60 is made smoothly, and accordingly, the second poppet valve 40 Is prevented from being temporarily opened, so the flow of oil is continuously smooth.

Therefore, the present invention not only prevents the chattering and hunting phenomenon, which is a conventional problem, but also improves the operation speed of the doser blade and greatly reduces noise.

3 is a schematic cross-sectional view showing a state in which the regeneration check ball 75 is built in the piston 60. The piston 60 includes a first piston 61, a second piston 65, and a regeneration check ball 75. ), The compression coil spring 74, the spring support bar 76.

The first piston 61 has an outer circumferential surface in close contact with the main passage 11 and slides along it, and an internal threaded portion 62 is formed on the inner circumferential surface thereof, and the first pressing part 20 opens and closes the first poppet valve 20 on one side thereof. The first oil passage 64 is formed to protrude 63 and both spaces of the main passage 11 are connected.

The second piston 65 has a male threaded portion 66 formed on an outer circumferential surface of the second piston 65 to be fastened to the female threaded portion 62 of the first piston 61, and has a second poppet valve 40 on the opposite side of the first pressurized portion 63. The second pressing portion 67 protrudes to open and close the second oil passage, and the second oil passage 69 is formed to connect the other space of the main passage 11 and the first oil passage 64 to the inner space 68. Opening and closing step 70 is formed in the inner circumference of the.

The regeneration check ball 75 is provided in the inner space 68 of the second piston 65 and the one side circumference is detached from the opening and closing step 70 of the second piston 65 so that the second oil passage 69 is provided. It is made in the shape of a sphere with a crackdown.

One end of the compressed coil spring 74 is supported by the regeneration check ball 75 and the other end thereof is supported by the first piston 61 to elastically support the regeneration check ball 75 at the opening and closing step 70.

The spring support bar 76 is supported by the first piston 61 and supported by the other end of the compression coil spring 74 to prevent the compression coil spring 74 from being separated.

The piston 60 of such a double pilot check valve is similar to the configuration of the piston 60 of FIGS. 1 and 2, and has the same operation and effect, and has a simple regeneration check instead of a complicated regeneration poppet 71. Only the point where the ball 75 is used is different.

4 is a schematic cross-sectional view showing a state in which the regeneration poppet unit 90 is embedded in the valve body 10 '. The double pilot check valve having the cavitation preventing device includes a valve body 10' and a first poppet valve ( 20), the second poppet valve 40, the piston 80, and the regeneration poppet unit 90.

The main body 11 is formed in the valve body 10 'so as to pass through the inner center thereof, and female threads 12 are formed at both ends of the main body 11 of the valve body 10'. One side of the valve body 10 ′ is provided with a first port 13 and a second port 14 so that external oil flows into one side of the main passage 11 and is discharged, and the other side of the first port 13. The third port 15 and the fourth port 16 are formed so that the oil passing through the 13 and the second port 14 flows into the other side of the main passage 11 and then discharges.

The valve body 10 'is provided with a connection port 17 in parallel with the main passage 11. The connection port 17 connects the fourth port 16 and the first port 13 so that oil in the fourth port 16 is supplied to the first port 13 side.

The first poppet valve 20 is coupled to one side of the main passage 11 of the valve body 10 'to open and close the first port 13 and the second port 14, the configuration and operation of which are shown in FIG. Since it is the same as described, duplicate description thereof will be omitted.

The second poppet valve 40 is coupled to the other side of the main passage 11 of the valve body 10 'to open and close the third port 15 and the fourth port 16, and its configuration and operation are shown in FIG. Since it is the same as described, duplicate description thereof will be omitted.

The piston 80 is coupled to slide in the main passage 11 of the valve body 10 '. One end of the piston 80 protrudes the first pressing part 81 to operate the first poppet valve 20, and the other end of the second pressing part 82 to operate the second poppet valve 40. Is protruded, while opening and closing the first poppet valve 20 or the second poppet valve 40 while reciprocating along the main passage (11).

The regeneration poppet unit 90 is installed at one side of the connection port 17 of the valve body 10 'and intercepts the flow of oil supplied from the connection port 17 to the first port 13, and the dozer blade cylinder. When the oil pressure is lowered due to its own weight and the oil pressure in the first port 13 and the second port 14 temporarily drops, the oil of the high pressure fourth port 16 side is supplied to the low pressure first port 13 side. .

The regeneration poppet unit 90 is composed of a regeneration poppet 91, a spring pressure adjusting bolt 94, a compression coil spring (95).

The regeneration poppet 91 is coupled to slide inside the valve body 10 ′, and an oil passage 92 is formed to supply oil to one side of the main passage 11 through the first port 13. And a tapered surface 93 is formed on the one side circumference detachable around the connection port 17 to control the flow of oil supplied from the connection port 17 to the first port 13 side.

The spring pressure adjusting bolt 94 is coupled to the valve body 10 ′ to prevent separation of the regeneration poppet 91 and to adjust the spring pressure.

One end of the compression coil spring (95) is supported by the regeneration poppet (91) and the other end is supported by the spring pressure adjusting bolt (94) so that the tapered surface (93) of the regeneration poppet (91) is around the connection port (17). Make it elastically supported.

The double pilot check valve equipped with the cavitation prevention device of the present invention having such a configuration is that when the cylinder for the dozer blade is lowered by its own weight, the hydraulic pressure of the first port 13 and the second port 14 is momentarily lowered. The high pressure oil of the other side of the main passage 11 is moved to one side of the main passage 11, so that the high pressure oil of the third port 15 and the fourth port 16 passes through the connecting port 17. After the regeneration poppet 91 of the pet part 90 is operated by pushing the first port 13 and the second port 14, the high pressure is maintained in the first port 13 and the second port 14.

As described above, as the high pressure is formed in the first port 13 and the second port 14 by the operation of the regeneration poppet 91 and the oil is supplied from the first port 13, the piston 80 The second poppet valve 40 is opened while being pushed toward the third port 15 and the fourth port 16.

Therefore, even when the dozer blade cylinder is lowered by its own weight, the first port 13 and the second port 14 maintain high pressure, so that the operation of the piston 80 is made smoothly, and accordingly, the second poppet valve 40 Is prevented from being temporarily opened, so the flow of oil is continuously smooth.

The double pilot check valve provided with the cavitation prevention device of the present invention is not provided with the regeneration poppet portion 90 inside the piston 80, but rather on the inside of the valve body 10 '. There is a characteristic.

The check valve of the present invention as described above is very easy to assemble and remove the regeneration poppet unit 90, loosening the spring pressure adjustment bolt 94 can easily separate the compression coil spring (95) and regeneration poppet (91) , After inserting the regeneration poppet 91 and the compression coil spring (95) to the connection port 17, the spring pressure adjustment bolt 94 is simply assembled. Therefore, the assembly and removal of the regeneration poppet unit 90 is very simple, so that the regeneration poppet unit 90, which is the main part of the check valve, can be easily repaired.

FIG. 5 is a schematic cross-sectional view showing a state where the regeneration poppet assembly 100 is coupled to one side of the valve body 10, and FIG. 6 is a circuit diagram of FIG. 5, wherein the double pilot check valve provided with the cavitation prevention device is a valve. The body 10, the first poppet valve 20, the second poppet valve 40, the piston 80, and the regeneration poppet assembly 100 are provided.

The main body 11 is formed in the valve body 10 so as to penetrate the inner center thereof, and female threads 12 are formed at both ends of the main body 11. One side of the valve body 10 is formed with a first port 13 and a second port 14 so that the external oil flows into one side of the main passage 11 and is discharged, the other side of the first port ( The third port 15 and the fourth port 16 are formed so that the oil passing through the 13 and the second port 14 flows into the other side of the main passage 11 and then discharges.

The first poppet valve 20 is coupled to one side of the main passage 11 of the valve body 10 to open and close the first port 13 and the second port 14, and the configuration and operation thereof are described in FIG. 2. Since it is the same as above, duplicate description thereof will be omitted.

The second poppet valve 40 is coupled to the other side of the main passage 11 of the valve body 10 to open and close the third port 15 and the fourth port 16, and the configuration and operation thereof are described in FIG. 2. Since it is the same as above, duplicate description thereof will be omitted.

The piston 80 is coupled to slide in the main passage 11 of the valve body 10. One end of the piston 80 protrudes the first pressing portion 81 to operate the first poppet valve 20, and the other end of the second pressing portion 82 to operate the second poppet valve 40. ) Protrudes and opens and closes the first poppet valve 20 or the second poppet valve 40 while reciprocating along the main passage 11.

The recycle poppet assembly 100 is coupled to the valve body 10 so as to be connected to the first port 13 and the fourth port 16, and the cylinder for the dozer blade is lowered by its own weight so that the first port 13 is closed. And when the oil pressure inside the second port 14 temporarily drops, the oil of the high pressure fourth port 16 side is supplied to the low pressure first port 13 side.

The regeneration poppet assembly 100 is composed of an assembly body 101, a regeneration poppet 105, a spring pressure adjusting bolt 108, a compression coil spring 109.

The assembly body 101 has a first auxiliary port 102 connected to the first port 13 of the valve body 10 so that external oil is supplied to the first port 13 side, and the first port ( 13) to the second auxiliary port 103 is connected to the fourth port 16 of the valve body 10 to discharge the oil via the fourth port 16, the first auxiliary port ( An auxiliary connection port 104 is formed to penetrate the 102 and the second auxiliary port 103.

The regeneration poppet 105 is coupled so as to slide inside the assembly body 101, and oil passes through the first auxiliary port 102 to be supplied to the first port 13 of the valve body 10. 106 is formed and a tapered surface 107 is formed to intercept the flow of oil supplied from the auxiliary connection port 104 to the first auxiliary port 102 side while being detached around the auxiliary connection port 104 on one side. It is.

The spring pressure adjusting bolt 108 is coupled to the assembly body 101 to prevent separation of the regeneration poppet 105 and to adjust the spring pressure.

One end of the compression coil spring 109 is supported by the regeneration poppet 105 and the other end is supported by the spring pressure adjusting bolt 108 so that the tapered surface 107 of the regeneration poppet 105 is circumferentially connected to the auxiliary connection port 104. To be elastically supported.

The double pilot check valve equipped with the cavitation prevention device of the present invention having such a configuration is that when the cylinder for the dozer blade is lowered by its own weight, the hydraulic pressure of the first port 13 and the second port 14 is momentarily lowered. The high pressure oil of the other side of the main passage 11 is moved to one side of the main passage 11, so that the high pressure oil of the third port 15 and the fourth port 16 is the second of the regeneration poppet assembly 100. After operating by pushing the regeneration poppet 105 through the auxiliary port 103, the auxiliary connection port 104 is supplied to the first auxiliary port 102, the high pressure oil is supplied to the first auxiliary port 102 The high pressure is maintained in the first port 13 and the second port 14 while being charged in the first port 13 and the second port 14.

As such, although the low pressure is instantaneously formed in the first port 13 and the second port 14 due to the lowering of the cylinder's own weight, the regeneration poppet 105 of the regeneration poppet assembly 100 is interlocked with the third port ( 15) and the high pressure oil of the fourth port 16 side are immediately filled to the first port 13 and the second port 14 side, and high pressure is formed in the first port 13 and the second port 14. .

Therefore, even when the dozer blade cylinder is lowered by its own weight, the first port 13 and the second port 14 maintain high pressure, so that the operation of the piston 80 is made smoothly, and accordingly, the second poppet valve 40 Is prevented from being opened temporarily.

Such a double pilot check valve with a cavitation prevention device of the present invention is characterized in that it can be recycled without discarding the conventional double pilot check valve. That is, when the regeneration poppet assembly 100 is assembled on the side of the valve body 10 of the conventional check valve by a bolt or welding method, a double pilot check valve having a cavitation prevention device is formed.

Therefore, since the valve body 10, the piston 80, the first poppet valve 20, the second poppet valve 40, which are components of the conventional check valve, can be recycled without being discarded, the compatibility is excellent and FIG. 1 Compared to the check valve of FIG. 4, the manufacturing cost can be greatly reduced.

10,10 ': Valve body 11: Main passage
12: female thread portion 13: first port
14: second port 15: third port
16: 4th port 17: connection port
20: 1st poppet valve 21: 1st poppet guide
22: first male threaded portion 23: first guide hole
24: 1st female thread part 25: 1st oil hole
26: first poppet 27: the first guide portion
28: first pressing portion 29: first tapered surface
30: first spring pressure adjusting bolt 31: first compression coil spring
40: 2nd poppet valve 41: 2nd poppet guide
42: second male thread 43: second guide hole
44: 2nd female thread part 45: 2nd oil hole
46: second poppet 47: second guide portion
48: second pressing portion 49: the second tapered surface
50: second spring pressure adjusting bolt 51: second compression coil spring
60, 80: piston 61: first piston
62: female thread portion 63,81: first pressing portion
64: first oil passage 65: first piston
66: male thread portion 67,82: second pressing portion
68: internal space 69: second oil passage
70: opening and closing step 71,91,105: regeneration poppet
72,92,106: Oil passage 73,93,107: Taper surface
74,95,109: Compression coil spring 75: Replay check ball
76: spring support 90: regeneration poppet
94,108: Spring pressure adjusting bolt 100: Recycled poppet assembly
101: assembly body 102: first auxiliary port
103: second auxiliary port 104: auxiliary connection port

Claims

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The main passage 11 is formed to penetrate the inner center, and the first port 13 and the second port 14 are formed on one side so that the external oil flows into one side of the main passage 11 and then discharged. The third port 15 and the fourth port 16 are formed such that oil passing through the first port 13 and the second port 14 on the other side flows into the other side of the main passage 11 and then discharges. Valve body 10;
A first poppet valve 20 coupled to one side of the main passage 11 of the valve body 10 to open and close the first port 13 and the second port 14;
A second poppet valve 40 coupled to the other side of the main passage 11 of the valve body 10 to open and close the third port 15 and the fourth port 16;
It is coupled to slide in the main passage 11 of the valve body 10, and opens and closes the first poppet valve 20 or the second poppet valve 40 while reciprocating along the main passage 11, free fall When the cylinder having the structure is lowered due to its own weight and the oil pressure in the first port 13 and the second port 14 drops temporarily, the oil at the high pressure of the third port 15 and the fourth port 16 is discharged. A piston 60 is provided to be supplied to the low pressure first port 13 and second port 14 side;
Piston 60,
The outer circumferential surface is in close contact with the main passage 11 and slides along it, and a female screw portion 62 is formed on the inner circumferential surface, and the first pressing portion 63 protrudes to open and close the first poppet valve 20 on one side thereof. Male thread portion 66 on the outer circumferential surface to be fastened to the first piston 61 in which the first oil passage 64 is formed to connect both sides of the 11 and the female screw portion 62 of the first piston 61. Is formed, and the second pressing part 67 protrudes to open and close the second poppet valve 40 on the opposite side of the first pressing part 63, and the other space of the main passage 11 and the first oil passage 64. The second piston 65 is formed so that the second oil passage (69) is connected, and the opening and closing step 70 is formed around the inner circumference of the inner space 68, and the inside of the second piston (65). It is coupled to slide in the space 68 and the oil passage 72 is formed so that the first oil passage 64 and the second oil passage 69 is connected, the second around one side The regeneration poppet 71 having a tapered surface 73 for attaching and detaching to the opening and closing step 70 of the stone 65 and controlling the second oil passage 69 and one end thereof is supported by the regeneration poppet 71. Cavitation preventing device, characterized in that the other end is supported by the first piston 61, the compression coil spring (74) for elastically supporting the tapered surface 73 of the regeneration poppet (71) to the opening and closing step (70). Double pilot check valve.

The main passage 11 is formed to penetrate the inner center, and the first port 13 and the second port 14 are formed on one side so that the external oil flows into one side of the main passage 11 and then discharged. The third port 15 and the fourth port 16 are formed such that oil passing through the first port 13 and the second port 14 on the other side flows into the other side of the main passage 11 and then discharges. Valve body 10;
A first poppet valve 20 coupled to one side of the main passage 11 of the valve body 10 to open and close the first port 13 and the second port 14;
A second poppet valve 40 coupled to the other side of the main passage 11 of the valve body 10 to open and close the third port 15 and the fourth port 16;
It is coupled to slide in the main passage 11 of the valve body 10, and opens and closes the first poppet valve 20 or the second poppet valve 40 while reciprocating along the main passage 11, free fall When the cylinder having the structure is lowered due to its own weight and the oil pressure in the first port 13 and the second port 14 drops temporarily, the oil at the high pressure of the third port 15 and the fourth port 16 is discharged. A piston 60 is provided to be supplied to the low pressure first port 13 and second port 14 side;
Piston 60,
The outer circumferential surface is in close contact with the main passage 11 and slides along it, and a female screw portion 62 is formed on the inner circumferential surface, and the first pressing portion 63 protrudes to open and close the first poppet valve 20 on one side thereof. Male thread portion 66 on the outer circumferential surface to be fastened to the first piston 61 in which the first oil passage 64 is formed to connect both sides of the 11 and the female screw portion 62 of the first piston 61. Is formed, and the second pressing part 67 protrudes to open and close the second poppet valve 40 on the opposite side of the first pressing part 63, and the other space of the main passage 11 and the first oil passage 64. The second piston 65 is formed so that the second oil passage (69) is connected, and the opening and closing step 70 is formed around the inner circumference of the inner space 68, and the inside of the second piston (65). And a spherical regenerated check ball 75 which is provided in the space 68 and whose one circumference is detached from the opening and closing step 70 of the second piston 65 and controls the second oil passage 69. It is supported by the regeneration check ball 75 and the other end is supported by the first piston (61) characterized in that the compression coil spring 74 for elastically supporting the regeneration check ball 75 to the opening and closing step 70 Double pilot check valve with cavitation prevention device.

The main passage 11 is formed to penetrate the inner center, and the first port 13 and the second port 14 are formed on one side so that the external oil flows into one side of the main passage 11 and then discharged. The third port 15 and the fourth port 16 are formed such that oil passing through the first port 13 and the second port 14 on the other side flows into the other side of the main passage 11 and then discharges. A valve body 10 'having a connection port 17 formed to supply oil in the fourth port 16 to the first port 13 side;
A first poppet valve 20 coupled to one side of the main passage 11 of the valve body 10 'to open and close the first port 13 and the second port 14;
A second poppet valve 40 coupled to the other side of the main passage 11 of the valve body 10 'to open and close the third port 15 and the fourth port 16;
The piston is coupled to slide in the main passage 11 of the valve body 10 ', and reciprocates along the main passage 11 to open and close the first poppet valve 20 or the second poppet valve 40 ( 80);
It is installed on one side of the connecting port 17 of the valve body 10 'to interrupt the flow of oil supplied from the connecting port 17 to the first port 13, and a cylinder having a free-falling structure is lowered by its own weight. When the oil pressure in the first port 13 and the second port 14 temporarily drops, the regeneration poppet unit 90 for supplying the high pressure oil on the fourth port 16 side to the low pressure first port 13 side Double pilot check valve provided with a cavitation prevention device characterized in that it is provided.

The method of claim 4, wherein the regeneration poppet unit 90,
It is coupled so as to slide inside the valve body 10 ', and an oil passage 92 is formed to supply oil to one side of the main passage 11 through the first port 13, and a connection port around one side ( 17, a regeneration poppet 91 and a valve body 10 'having a tapered surface 93 formed therein, which is detached around the periphery and intercepts the flow of oil supplied from the connection port 17 to the first port 13 side. It is coupled to the spring pressure control bolt 94 to prevent separation of the regeneration poppet (91) and to adjust the spring pressure, and one end is supported by the regeneration poppet (91) and the other end is supported by the spring pressure adjustment bolt (94) Double pilot check valve provided with a cavitation prevention device, characterized in that the tapered surface 93 of the poppet (91) is made of a compression coil spring (95) to be elastically supported around the connection port (17).

The main passage 11 is formed to penetrate the inner center, and the first port 13 and the second port 14 are formed on one side so that the external oil flows into one side of the main passage 11 and then discharged. The third port 15 and the fourth port 16 are formed such that oil passing through the first port 13 and the second port 14 on the other side flows into the other side of the main passage 11 and then discharges. Valve body 10;
A first poppet valve 20 coupled to one side of the main passage 11 of the valve body 10 to open and close the first port 13 and the second port 14;
A second poppet valve 40 coupled to the other side of the main passage 11 of the valve body 10 to open and close the third port 15 and the fourth port 16;
It is coupled to slide in the main passage 11 of the valve body 10, the piston 80 for opening and closing the first poppet valve 20 or the second poppet valve 40 while reciprocating along the main passage (11). );
Coupled to the valve body 10 so as to be connected to the first port 13 and the fourth port 16, the cylinder having a free-falling structure is lowered by its own weight, so that the first port 13 and the second port 14 Cavitation prevention device, characterized in that provided with; regeneration poppet assembly 100 for supplying the high pressure of the fourth port 16 side oil to the low pressure first port 13 side when the oil pressure temporarily drops inside Double pilot check valve provided.

The method of claim 6, wherein the regeneration poppet assembly 100,
A first auxiliary port 102 connected to the first port 13 of the valve body 10 is formed so that external oil is supplied to the first port 13 side, and the first port 13 to the fourth port ( A second auxiliary port 103 connected to the fourth port 16 of the valve body 10 is formed to discharge the oil via the 16, and the first auxiliary port 102 and the second auxiliary port 102 are formed in the middle portion thereof. An assembly body (101) having an auxiliary connection port (104) formed to penetrate (103) is coupled to slide in the assembly body (101), and oil passes through the first auxiliary port (102) to the valve body. An oil passage 106 is formed to be supplied to the first port 13 of the 10 and is detached around the auxiliary connection port 104 on one side thereof, while the first auxiliary port 102 is connected to the auxiliary connection port 104. It is coupled to the regeneration poppet 105 and the assembly body 101 in which a tapered surface 107 is formed to control the flow of oil supplied to the side. Spring pressure adjustment bolt 108 to prevent the departure of the poppet 105 and adjust the spring pressure, and one end is supported by the regeneration poppet 105 and the other end is supported by the spring pressure adjustment bolt 108 to play the regeneration poppet 105 Double pilot check valve provided with a cavitation prevention device, characterized in that the tapered surface 107 of the compression coil spring 109 to be elastically supported around the auxiliary connection port (104).