JPH11201309A - Bi-directional valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent leakage of liquid from a valve part at the time of valve opening. SOLUTION: A spool 47 and a spool 58 are housed in a first valve hole 38 and a second valve hole 40, respectively. The spool 47 is caused to abut on a stopper wall 57 between the two valve holes by a spring 48 of strong energizing force while the spool 58 is caused to abut on the spool 47 by a spring 59 of weak energizing force. A center hole 50 and a branch hole 51 are formed in the spool 47 while a radial hole 63 and an annular groove 62 in the spool 58. An annular groove 46 is formed in the first valve hole 38 for causing the annular groove 62 to communicate with the branch hole 51 when the spool 58 projects into the valve hole 38. When liquid flows from a passage A to a passage B, the two spools 47, 58 part from each other to open the center hole 50, and, when liquid flows from the passage B to the passage A, the two spools 47, 58 remain abutting on each other to cause the annular groove 62 to communicate with the branch hole 51. Leakage of liquid at the time of valve opening is checked by an abutting part between the spools 47, 58 and by an abutting part of the spool 47 on the stopper wall 57.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way valve which is interposed in a flow passage and permits only the flow of a liquid having a pressure equal to or higher than a set pressure. It relates to a two-way valve with possible improvements.

[0002]

2. Description of the Related Art A two-way valve of this type is disclosed in
The one shown in 149577 has conventionally been devised.

In this two-way valve, as shown in FIG. 6, an external first flow path 2 and an external second flow path 3 are electrically connected to a valve housing 1, and a two-way valve is provided in a valve hole 4 of the valve housing 1. 1
A spool 5 and a second spool 6 are slidably accommodated. The first spool 5 and the second spool 6 are urged by a first spring 7 and a second spring 8 in a direction where their ends come into contact with each other. The second spool 6 is formed with a center hole 9 communicating the first flow path 2 side and the second flow path 3 side, and the center hole 9 is provided in a state where the first spool 5 and the second spool 6 are in contact with each other. 9 is closed by the first spool 5. Further, flanges 5a, 6a are formed at the bases of the spools 5, 6, and these flanges 5a, 6a are formed.
a, 6a are stepped shoulders 10, 1 recessed in the valve hole 4.
1 to regulate the displacement of the spools 5 and 6 in the forward direction. The first spring 7 for urging the first spool 5 in the forward direction is set to a relatively strong urging force, and the second spring 8 for urging the second spool 6 in the forward direction is set to an extremely weak urging force. Have been.

Therefore, in this two-way valve, when the pressure of the liquid on the first flow path 2 side becomes larger than that on the second flow path 3 side, the displacement of the first spool 5 causes the contact between the flange 5a and the shoulder portion 10 to move. The second spool 6 retreats in a state where it is restricted by the contact, and at that time, the center hole 9 of the second spool 6 is opened, and the liquid flows from the first flow path 2 to the second flow path 3 side. Conversely, when the pressure of the liquid on the side of the second flow path 3 becomes larger than the pressure on the side of the first flow path 2 by a set value or more, the displacement of the second spool 6 is caused by the contact between the flange 6 a and the shoulder 11. The first spool 5 is retracted due to the regulation, and at that time, the center hole 9 of the first spool 5 is also opened and the liquid flows from the second flow path 3 to the first flow path 2 side. The valve opening pressure (first valve opening pressure) when the liquid flows in the direction from the first flow path 2 to the second flow path 3 is the pressure receiving area of the second spool 6 and the second pressure acting as the weak urging means. The valve opening pressure (second valve opening pressure) when the liquid flows in the direction from the second flow path 3 to the first flow path 2 is determined by the urging force of the spring 8, and the pressure receiving area of the first spool 5 It is determined by the urging force of the first spring 7 which is the strong urging means.

[0005]

In the above-mentioned conventional two-way valve, the center hole 9 of the second spool 6 is closed by bringing the end faces of the first spool 5 and the second spool 6 into contact with each other, and the first flow is thus prevented. The structure is such that the path 2 and the second flow path 3 are shut off. However, if there is a pressure difference between the second flow path 3 and the first flow path 2 in the valve-closed state where the first spool 5 and the second spool 6 are in contact with each other, the liquid is discharged from both spools 5 and 6.
Of the valve hole 4 and the outer peripheral surface of the second spool 6 as well as the abutting portion (closed portion of the center hole 9). It is conceivable that there is a possibility of leakage to the first flow path 2 side through the sliding gap between the hole 4 and the second spool 6.

In the two-way valve, the flanges 5a, 6a of the spools 5, 6 are connected to the shoulders 10, 1 of the valve hole 4.
Since the spools 5 and 6 are in contact with each other in the axial direction to restrict the displacement of the spools 5 and 6 in the forward direction, the flanges of the spools 5 and 6 are closed when the spools 5 and 6 are in contact with each other. By ensuring that the 5a, 6a is in close contact with the corresponding shoulders 10, 11, the outer peripheral surface of the second spool 6 and the valve hole 4
Although it is possible to prevent the liquid from leaking from the gap between the spools 5 and 6, it is practically necessary to simultaneously contact the flanges 5a and 6a of the spools 5 and 6 with the corresponding shoulders 10 and 11 due to processing accuracy and the like. Above is impossible.

In particular, when a two-way valve is used in a hydraulic pipe of an engine operating device of a vehicle, if the leakage of the liquid from the valve portion cannot be reliably prevented in the closed state, the engine has been stopped for a long time. In some cases, the liquid in the flow path escapes due to gravity, causing a problem that the engine cannot be restarted smoothly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a two-way valve capable of reliably preventing liquid from leaking from a valve portion when the valve is closed.

[0009]

Means for Solving the Problems As means for solving the above-mentioned problems, the invention according to claim 1 is provided between the first flow path and the second flow path, and When the flow of the liquid from the flow path to the second flow path exceeds the first valve opening pressure, the flow of the liquid from the second flow path to the first flow path exceeds the second valve opening pressure. In a two-way valve that sometimes permits the flow of liquid, a large-diameter first valve hole communicating with the first flow path and a small-diameter second valve hole communicating with the second flow path are provided in the valve housing. Are formed continuously, and a stopper wall perpendicular to both holes is formed at a connection portion of the first valve hole with the second valve hole, and a large-diameter second valve hole is formed in the first valve hole and the second valve hole. The first spool and the second spool having a small diameter are slidably accommodated, respectively, and the first spool is urged in the direction in which the first spool is brought into contact with the stopper wall. The energization means is provided, the second valve hole, the second
Weak urging means for urging the spool in a direction in which the spool comes into contact with the first spool is provided. The first spool has a center hole through which a contact end face with the second spool and the first flow path are connected. While forming a branch hole that connects the hole and the outer peripheral surface of the first spool, a conductive path that connects the outer circumference of the end of the second spool on the first spool side and the second flow path is formed in the second spool. A bypass groove is formed between the first spool and the first valve hole to connect the conduction path of the second spool and the branch hole of the first spool when the second spool projects into the first valve hole. I made it.

In the two-way valve of the present invention, when the hydraulic pressure in the first flow path is higher than the hydraulic pressure in the second flow path and the pressure difference is higher than the first valve opening pressure, While the first spool is in contact with the stopper wall, the second spool retreats against the force of the weak urging means. At this time, the center hole of the first spool is opened and the second spool is moved from the first flow path to the second spool. The liquid flows in the flow path. On the other hand, when the hydraulic pressure of the second flow path is higher than the hydraulic pressure of the first flow path and the pressure difference is higher than the second valve opening pressure, the second spool and the first spool are connected to each other. While the spools are in contact with each other, the spools are displaced against the force of the strong urging means. At this time, at the same time when the first spool is separated from the stopper wall, the second spool projects into the first valve hole, and the conduction path of the second spool and the branch hole of the first spool are conducted through the bypass groove. The liquid flows from the second flow path to the first flow path. Further, in the valve closed state, the first
Leakage of the liquid from the center hole portion of the spool is reliably prevented by contact between the end faces of the first spool and the second spool, and leakage of the liquid from the peripheral region of the first spool and the second spool is prevented. The contact between the end surface of the first spool and the stopper wall surely prevents the stopper.

According to a second aspect of the present invention, in the first aspect of the present invention, the valve housing comprises a housing body having a first valve hole and a plug having a second valve hole. A continuous screw hole is formed in the first valve hole, and a front end surface of the plug forms a stopper wall, and an outer peripheral surface forms a boss portion screwed into the screw hole of the housing body. When assembling the two-way valve, the housing body is assembled with the strong urging means and the first spool in the first valve hole of the housing body and the weak urging means and the second spool in the second valve hole of the plug, respectively. Screw the plug boss into the screw hole.

According to a third aspect of the present invention, in the second aspect of the present invention, a flange is provided on the boss portion so as to face a screw hole edge of the housing body, and the flange is provided between the flange and the screw hole edge. The shim can be interposed, and a restricting means for restricting a screwing depth of the plug into the housing body is formed between the end of the screw hole and the flange.

According to a fourth aspect of the present invention, in the second or third aspect, a small-diameter straight portion that does not cut a thread groove is provided on the outer periphery of the tip of the boss portion of the plug.
A fitting surface into which the straight portion is fitted is formed at the deepest portion of the screw hole of the housing body. When the boss portion of the plug is screwed into the screw hole of the housing body, the straight portion at the tip of the boss portion is finally fitted into the deepest fitting surface of the screw hole. Therefore, the burrs generated at the time of screwing are captured before the portion where the straight portion is fitted, and do not enter the valve hole.

According to a fifth aspect of the present invention, the invention according to any one of the first to fourth aspects is used for a hydraulic pipe of an engine operating device of a vehicle.

According to a sixth aspect of the present invention, in the fifth aspect, the valve housing is formed integrally with the engine operating device.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS.
A description will be given based on FIG.

FIGS. 1 to 3 show a two-way valve 2 according to the present invention.
FIG. 4 is a sectional view of an engine operating system using the two-way valve 20.

Before detailed description of the specific structure of the two-way valve 20 according to the present invention, the engine operating system shown in FIG. 4 will be briefly described.

This engine operation system is a system for directly injecting fuel pressurized to a high pressure into each cylinder (not shown) of the engine. An injector in which fuel in a fuel tank 21 is disposed in each cylinder is provided. A fuel supply circuit for supplying oil to the injectors 22 from the oil pan 24 to the injectors 22;

The fuel supply circuit 23 sends out the fuel in the fuel tank 21 to each injector 22 by a fuel pump 26, pressurizes the fuel to a high pressure with each injector 22 and injects the fuel into a cylinder. Is returned to the fuel tank 21. Reference numeral 27 denotes a filter interposed in the fuel supply circuit 23.

The oil supply circuit 25 supplies the oil stored in the oil pan 24 to a high-pressure pump 29 by a feed pump 28, and supplies the oil to the high-pressure pump 29.
And pressurized to a high pressure oil manifold 30 which communicates with the working chamber of each injector 22. A pressure control valve 31 is provided in the downstream passage 36 of the high-pressure pump 29, and the pressure control valve 31 is connected to the drain passage 3.
2 is opened and closed as appropriate, whereby the high pressure oil manifold 30
The internal fluid pressure is increased or decreased. The pressure control valve 31 is controlled by the controller 33 together with the injection mechanism of the injector 22, and adjusts the hydraulic pressure in the high-pressure oil manifold 30 to an optimum value according to the engine speed, load state, and the like. In the figure, 34 and 35 are oil supply circuits 2
5 is an oil cooler and an oil filter interposed respectively.

The two-way valve 20 according to the present invention is interposed between the pressure control valve 31 of the downstream passage 36 and the high-pressure oil manifold 30, and is connected to the high-pressure oil manifold 3 by the pressure control valve 31.
The flow of oil in the forward direction toward the zero side and the flow of oil in the reverse direction from the high-pressure oil manifold 30 toward the pressure control valve 31 are both allowed. However, the flow of oil in the forward direction is allowed when the differential pressure across the two-way valve 20 exceeds the first valve opening pressure (a very small value), and the flow of oil in the reverse direction is The differential pressure before and after the second
Above the valve opening pressure.
The first valve opening pressure and the second valve opening pressure are both set to values far smaller than the normal oil pressure when the engine is operating. The value is set to a value that can reliably prevent the outflow of oil from the flow path on the high-pressure oil manifold 30 side when the flow path on the control valve 31 side is at atmospheric pressure. In this embodiment, the pressure control valve 31 side of the downstream side passage 36 sandwiching the two-way valve 20 is the first flow path A in the present invention, and the high pressure oil manifold 30 side is the second flow path B in the present invention. It has become.

As shown in FIG. 1, the two-way valve 20 includes a housing body 39 in which a valve housing 37 has a first valve hole 38 having a large diameter, and a plug 4 having a second valve hole 40 having a small diameter.
A first port 42 is formed in the housing main body 39 to connect the first flow path A and the first valve hole 38, and a second flow path B and a second valve hole 40 are formed in the plug 41. Is formed.

In the housing body 39, the first port 42 is connected to one end of the first valve hole 38 via a step wall 44, and a screw hole 45 is formed continuously at the other end. An annular groove 46 is formed at the end of the first valve hole 38 on the screw hole 45 side as a bypass groove having substantially the same diameter as the screw hole 45. A large-diameter first spool 47 is slidably housed in the first valve hole 38, and the first spool 47 is connected to the distal end side of the housing body 39 (the screw hole 45).
First spring 48 as a strong urging means for urging the first spring 48)
Is housed. The first spring 48 is interposed between a concave portion 49 formed at the base end of the first spool 47 and the step wall 44 of the housing body 39. The first spool 47 is formed with a center hole 50 that connects the tip end surface to the first port 42 side, and connects a substantially middle portion of the center hole 50 to the outer peripheral surface of the first spool 47. A branch hole 51 is formed. The radially outer end of the branch hole 51 is always in communication with the annular groove 46 of the housing body 39.

On the other hand, the plug 41 has a boss 52 formed at the distal end thereof to be screwed into the screw hole 45 of the housing body 39, and a flange 53 formed on the outer periphery of the base end of the boss 52. The flange 53 is provided with the boss 52 in the screw hole 4.
When the boss portion 52 is screwed into the screw hole 45 by a predetermined amount at a portion where the screwing depth when screwed into the screw hole 5 is screwed, the boss portion 52 comes into contact with the front end surface 39a of the housing body 39 (the edge of the screw hole 45). ing. A tapered surface 54 is formed at the inner peripheral edge of the tip of the housing body 39,
A seal ring 56 is interposed between the tapered surface 54 and a base corner 55 of the flange 53. The second valve hole 40 is formed so as to open toward the distal end surface of the boss portion 52. The edge of the opening of the second valve hole 40, that is, the distal end surface of the boss portion 52 is the first, second, The stopper wall 5 is formed so as to be orthogonal to the valve holes 38 and 40, and contacts the distal end surface of the first spool 47 urged by the first spring 47.
It is 7.

In the second valve hole 40, a small-diameter second spool 58 is slidably accommodated, and a weak pressure is applied to bias the second spool 58 in a direction in which the second spool 58 comes into contact with the first spool 47. A second spring 59 as a biasing means is accommodated. The second spring 59 is interposed between a step wall 60 at the bottom of the second valve hole 40 and a concave portion 61 formed at the base end of the second spool 58. The distal end surface of the second spool 58 abuts against the distal end surface of the first spool 47 to close the center hole 50 of the first spool 47. The second spool 58 has an annular groove 62 formed on the outer periphery of the distal end portion thereof, and a radial hole 63 communicating between the annular groove 62 and the inside of the concave portion 61. The annular groove 62 and the radial hole 63 constitute a conduction path in the present invention for conducting the outer periphery of the end of the second spool 58 to the second flow path B.

In the two-way valve 20, the first spool 47 is urged by a first spring 48, which is a strong urging means, and the second spool 58 is urged by a second spring 59, which is a weak urging means. Therefore, in the initial state in which no hydraulic pressure acts on the first flow path A and the second flow path B, the distal end surface of the first spool 47 abuts against the stopper wall 57 and the distal end of the second spool 58 The surface is the first spool 47
Is in contact with the tip end surface.

In the above configuration, when the hydraulic pressure in the first flow path A becomes larger than the hydraulic pressure in the second flow path B and the pressure difference becomes larger than the first valve opening pressure, As shown in FIG. 2, the second spool 58 retreats against the force of the second spring 59 while the distal end surface of the first spool 47 is in contact with the stopper wall 57. 50 is opened. Therefore, at this time, the oil in the first flow path A passes through the center hole 50 to the outer peripheral side of the second spool 58, and further passes through the annular groove 62 and the radial hole 63 of the second spool 58, and the second flow It will flow to Road B.

On the other hand, the hydraulic pressure in the second flow path B becomes larger than the hydraulic pressure in the first flow path A, and the pressure difference becomes the second hydraulic pressure.
When the valve opening pressure becomes larger than the first valve opening pressure, as shown in FIG.
The spool 47 and the second spool 58 are displaced against the force of the first spring 48 while the tip surfaces contact each other. At this time, the tip surface of the first spool 47, which has been in contact with the first spool 47, separates from the stopper wall 57, and at the same time, the second spool 5
8 protrudes into the first valve hole 38, so that the annular groove 62 of the second spool 58 and the annular groove 46 of the first valve hole 38 communicate with each other. Therefore, at this time, the oil in the second flow path B passes through the radial hole 63 and the annular groove 62 of the second spool 58 to the annular groove 46 in the first valve hole 38, and further the branch hole of the first spool 47. The fluid flows to the first flow path A through the central hole 51 and the center hole 50.

Further, the second flow path B and the first flow path A
When the hydraulic pressure difference between the first flow path A and the second flow path B is equal to or less than the first valve opening pressure,
The two-way valve 20 is in a closed state as shown in FIG. 1. At this time, oil leaks from the center hole 50 of the first spool 47 due to the leading end surface of the second spool 58 and the first spool 47. Oil leakage from the outer peripheral areas of the first and second spools 47 and 58 is prevented by the contact between the outer peripheral area of the first spool 47 and the stopper wall 57. Blocked by contact. Therefore,
This two-way valve 20 can reliably prevent oil from leaking between the first flow path A and the second flow path B in the closed state, and is used for an engine operating system as shown in FIG. If so, the hydraulic pressure on the second flow path B side, that is, the hydraulic pressure on the high-pressure oil manifold 30 side can be maintained at least at the second valve opening pressure with respect to the minimum atmospheric pressure.

As a result, the engine stops for a long time,
Even if the oil in the pipe may escape to the outside through the high pressure pump 29 or the drain passage 32 of the pressure control valve 31 due to gravity, at least the two-way valve 20 and the high pressure oil manifold 3
The oil between zero is prevented from flowing out by the function of the two-way valve 20. Therefore, when the engine is restarted from this state, the pressure in the high-pressure oil manifold 30 is immediately increased to a predetermined pressure, and the engine can be restarted smoothly.

In the two-way valve 20, the valve housing 37 comprises a housing body 39 having a first valve hole 38 and a plug 41 having a second valve hole 40. The first spring 48 and the first spool 47 are accommodated in the hole 38, and the second spring 59 and the second spool 58 are accommodated in the second valve hole 40. In this state, the boss 52 of the plug 41 is inserted into the screw hole 45 of the valve body 39. Can be assembled simply by screwing in. Therefore, the assemblability is extremely good and the production at low cost is possible. Further, in the case of the two-way valve 20, the distal end surfaces of the first and second spools 47 and 58 and the distal end surface of the boss portion 52 of the plug 41 are in close contact with each other in a closed state. Since it is the end face of each component, it is possible to very easily perform a precise finishing process. In addition, since the housing body 39 and the plug 41 have a structure that does not have recess processing or long hole processing,
Since processing is easy and there is no intricate structural part, foreign matter removal processing by washing performed before assembly of parts can be easily and reliably performed.

Further, in the two-way valve 20, the flange 53 extending from the boss portion 52 of the plug 41 abuts against the front end surface 39 a of the housing body 39, so that the screwing depth of the boss portion 52 into the housing body 39 can be reduced. Although the structure is such that a proper number and thickness of shims are interposed between the distal end surface 39a of the housing body 39 and the flange 53, the screwing depth of the boss portion 52, that is, the strong urging means , The urging force of the first spring 48 can be easily adjusted.

If the valve housing 37 of the two-way valve 20 is formed integrally with any engine operating device such as the high-pressure pump 29, the number of parts including the number of pipes is greatly reduced, and the structure is simplified. Therefore, the weight and size of the device can be reduced, and the cost can be reduced.

The embodiment of the present invention is not limited to the above-described embodiment. For example, in the above embodiment, the outer periphery of the end of the second spool 58 on the first spool 47 side and the second flow Although the conduction path for conducting the path B is formed by the annular groove 62 and the radial hole 63, other path shapes may be used. In the above-described embodiment, the bypass groove (annular groove 46) that connects the annular groove 62 of the second spool 58 and the branch hole 51 of the first spool 47 is formed on the inner peripheral surface of the first valve hole 38. Alternatively, a bypass groove may be formed on the outer peripheral surface side of the first spool 47.

Further, as shown in FIG.
A small-diameter straight portion 65 that does not cut a screw groove is formed on the outer periphery of the tip of the boss portion 52.
5 is a fitting surface 66 into which the straight portion 65 is fitted.
May be provided. If you do this,
The fitting of the straight portion 65 and the fitting surface 66 reliably prevents the burrs 67 generated when the boss portion 52 is screwed into the screw holes 45 of the housing body 39 from entering the valve holes 38 and 40. Can be. That is, when the boss portion 52 is screwed into the screw hole 45 of the housing body 39, the generated burrs 67 are formed on the thread 52a of the boss portion 52.
However, when the screwing of the boss portion 52 is nearly completed, the straight portion 65 at the tip of the boss portion 52 is fitted into the fitting surface 67, and the deepest portion of the screw hole 45 closed by the screw portion 45 is closed. The burrs 66 are confined in the space 68 of the part, so that the burrs 67 do not enter the first and second valve holes 38 and 40.
Therefore, when such a structure is adopted, the intrusion of the burrs 67 into the circuit can be reliably prevented, and the failure of the equipment to be used due to the intrusion of the burrs 67 and the performance degradation can be reliably prevented.

[0037]

As described above, the invention according to claim 1 is
When flowing the liquid from the first flow path to the second flow path,
With the forward displacement of the first spool restricted by the stopper wall, the second spool is retracted to open the center hole of the first spool, and conversely, the liquid flows from the second flow path to the first flow path. In this case, the first spool protrudes into the first valve hole in a state where the first spool and the second spool are in contact with each other, so that the conduction path of the second spool and the branch path of the first spool are formed in the bypass groove. Can be conducted through
In addition, when the valve is closed, the center hole of the first spool is sealed with the end face of the second spool, so that leakage of liquid from the center hole portion can be reliably prevented, and the outer peripheral area of the end face of the first spool is connected to the stopper wall. The close contact can reliably prevent the liquid from leaking from the outer peripheral areas of the first and second spools.
Also, the part that closes when closing the valve to prevent leakage of liquid is
Since both the end faces of the first and second spools and the stopper wall are flat portions, these portions can be easily and precisely finished.

According to a second aspect of the present invention, in the first aspect of the present invention, the valve housing includes a housing body having a first valve hole and a plug having a second valve hole. The first valve hole is formed with a continuous screw hole, the plug has a front end surface forming a stopper wall, and the outer peripheral surface forms a boss portion which is screwed into the screw hole of the housing main body. Screwing the boss portion of the plug into the screw hole of the housing body with the strong urging means and the first spool installed in the first valve hole and the weak urging means and the second spool installed in the second valve hole of the plug, respectively. Thus, it is possible to easily assemble, and further, it is possible to easily exchange parts by loosening the screwing.
Further, since the tip surface of the boss formed on the plug is used as the stopper wall, the stopper wall can be easily and accurately processed.

According to a third aspect of the present invention, in the second aspect of the present invention, a flange is provided on the boss portion so as to face a screw hole edge of the housing body, and the flange is provided between the flange and the screw hole edge. And a restricting means for restricting the depth of screwing of the plug into the housing body is formed between the edge of the screw hole and the flange. By changing the number or thickness of the shims to be mounted, the urging force of the strong urging means can be easily changed.

According to a fourth aspect of the present invention, in the second or third aspect of the present invention, a small-diameter straight portion that does not cut a thread groove is provided on the outer periphery of the tip of the boss portion of the plug.
Since the fitting surface into which the straight portion is fitted is formed at the deepest portion of the screw hole of the housing body, the flash generated when the plug and the housing body are screwed into the valve hole is prevented from entering the valve hole. It can be reliably prevented by the fitting portion. Therefore, it is possible to eliminate the problem that the burrs are mixed into the liquid in the circuit at the time of actual use, and to prevent the failure of the equipment to be used or the performance degradation due to the burrs being mixed in beforehand.

According to a fifth aspect of the present invention, the invention according to any one of the first to fourth aspects is used for a hydraulic pipe of an engine operating device of a vehicle, so that the engine is stopped for a long time. Also, the fluid in the hydraulic pipe does not flow out due to gravity, and a smooth restart of the engine can be guaranteed.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, since the valve housing is formed integrally with the engine operating device, the number of parts including the number of pipes can be greatly reduced. It is possible to reduce the weight and cost of the apparatus by simplifying the structure.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the embodiment.

FIG. 3 is a sectional view showing the embodiment.

FIG. 4 is a piping diagram of an engine operation system showing the embodiment.

FIG. 5 is an enlarged sectional view corresponding to a portion D in FIG. 1 showing another embodiment of the present invention.

FIG. 6 is a sectional view showing a conventional technique.

[Explanation of symbols]

 Reference numeral 20: two-way valve, 37: valve housing, 38: first valve hole, 39: housing body, 39a: distal end surface (edge of screw hole), 40: second valve hole, 41: plug, 45: screw hole, 46 ... circular groove (bypass groove), 47 ... first spool, 48 ... first spring (strong urging means), 50 ... center hole, 51 ... branch hole, 52 ... boss, 53 ... flange, 57 ... stopper wall, 58: second spool, 59: second spring (weak urging means), 62: annular groove (conduction path), 63: radial hole (conduction path), 65: straight portion, 66: fitting surface, A: 1st flow path, B ... 2nd flow path.

Claims (6)

[Claims] 1. A method according to claim 1, wherein a flow of the liquid from the first flow path to the second flow path is interposed between the first flow path and the second flow path and exceeds a first valve opening pressure. A two-way valve that permits the flow of liquid when the flow of liquid from the second flow path to the first flow path exceeds the second valve opening pressure. A large-diameter first valve hole that conducts and a small-diameter second valve hole that communicates with the second flow path are continuously formed, and a connecting portion between the first valve hole and the second valve hole in the first valve hole is formed. A stopper wall orthogonal to both holes is formed, and a first spool having a large diameter and a second spool having a small diameter are slidably accommodated in the first valve hole and the second valve hole, respectively. A strong urging means is provided for urging the first spool in a direction in which the first spool comes into contact with the stopper wall, and is urged in the second valve hole in a direction in which the second spool comes into contact with the first spool. Weak biasing means provided in the first spool, the abutment end face of the second spool and the first
And a branch hole that connects the center hole to the outer peripheral surface of the first spool.
A conduction path is formed in the spool to connect the outer periphery of the end of the second spool on the first spool side to the second flow path, and the second spool is provided between the first spool and the first valve hole. A two-way valve, wherein a bypass groove is formed to connect the conduction path of the second spool and the branch hole of the first spool when protruding into the hole. 2. The valve housing comprises a housing body having a first valve hole, and a plug having a second valve hole, wherein a screw hole continuous with the first valve hole is formed in the housing body. 2. The two-way valve according to claim 1, wherein the distal end surface forms a stopper wall, and the outer peripheral surface forms a boss portion screwed into a screw hole of the housing body. 3. The boss portion is provided with a flange facing the edge of the screw hole of the housing body to enable the shim to be interposed between the flange and the edge of the screw hole. The two-way valve according to claim 2, wherein a restricting means for restricting a screwing depth of the plug with respect to the housing body is formed between the flanges. 4. A plug having a small-diameter straight portion which does not cut a thread groove on the outer periphery of a tip of a boss portion of a plug, and a fitting surface into which the straight portion is fitted is formed at a deepest portion of a screw hole of a housing body. A two-way valve according to claim 2 or 3, characterized in that: 5. The two-way valve according to claim 1, wherein the two-way valve is used in a hydraulic pipe of an engine operating device of a vehicle. 6. The two-way valve according to claim 5, wherein the valve housing is formed integrally with the engine operating device.