JP2005273555A - Regulator for high-pressure fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal structure of a valve shaft of a pressure control valve which ensures the sealing performance, improves the pressure regulation characteristic, enhances the pressure regulating reliability or the pressure regulation performance, and prevents a seal member from being pushed up to the high-pressure section which has been reduced in pressure by a semi-high pressure generated in the lower-pressure section when the pressure of the high-pressure section separated by the seal member as a border is decreased rapidly. <P>SOLUTION: The seal member 50 is mounted on the valve shaft of the pressure control valve. The seal member 50 is comprised of a seal main body 51 having a cross-section formed in a U-shaped configuration with a recess 53 at its central portion, and a metal spring 52 provided in the recess 53 of the seal main body 51 so as to urge both side pieces 51a, 51b of the seal main body 51 in such a direction that both the side pieces 51a, 51b are made to extend more apart from each other. The opening portion of the recess 53 of the seal main body 51 is arranged on the side of the high-pressure section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a regulator for high pressure fluid.

  Conventionally, in order to use compressed natural gas as a fuel for an automobile engine, a regulator for high pressure fluid as shown in FIGS. 5 and 6 is used as a regulator for reducing the compressed natural gas in a cylinder mounted on the automobile to a predetermined pressure. It is known (see Patent Document 1).

The high-pressure fluid regulator 1 shown in FIGS. 5 and 6 will be described.
The body 2 is formed with an inlet 3 and an outlet 4 for high-pressure fluid, and the high-pressure fluid flowing in from the inlet 3 is supplied to the valve housing chamber 6, the seat 7, the flow passage 8, and the pressure regulation formed in the housing 5. It flows through the chamber 9 and is supplied from the outlet 4 to the engine or the like.

  A pressure regulating valve 10 is provided in the valve storage chamber 6 of the housing 5 so as to be slidable in the axial direction, and the pressure regulating valve 10 contacts and separates from the seat 7. Furthermore, a rod 11 projects from one end of the pressure regulating valve 10, that is, the upper end in the figure so as to penetrate the flow passage 8, and the tip of the rod 11 is a diaphragm 12 provided in the pressure regulating chamber 9. It is connected to.

  A valve shaft 13 protrudes from the other end of the pressure regulating valve 10, that is, the lower end in the figure, and the valve shaft 13 is stored in the valve storage chamber 6. A ring 14 is fitted between the inner peripheral surface of the valve storage chamber 6 and the outer peripheral surface of the valve shaft 13, and a spring 15 is interposed between the ring 14 and the pressure regulating valve 10. The pressure regulating valve 10 is constantly urged toward the seat 7 by the urging force.

  Further, a rubber O-ring 16 is fitted on the outer peripheral surface of the valve shaft 13 in a crimped state, and the outer peripheral surface of the O-ring 16 is connected to the inner peripheral surface of the housing 5, that is, the inner peripheral surface of the valve storage chamber 6. Crimped. The O-ring 16 is supported by two types of backup rings 17 and 18. Further, an O-ring 19 and a backup ring 20 are attached to the lower portion of the valve shaft 13, that is, the low-pressure side portion.

  A stopper 21 is provided on the opposite side of the valve storage chamber 6 across the O-ring 16, and a gap 21 a is formed in the stopper 21. The gap 21 a is connected to the pressure regulating chamber 9 by a passage 22. Communicate.

  The diaphragm 12 divides the pressure regulating chamber 9 and the atmospheric pressure chamber 23 and is always urged downward by a predetermined load by a spring 24.

  With the above configuration, when the pressure in the pressure regulating chamber 9 decreases to a predetermined value or less in a state where the high-pressure fluid acts on the valve storage chamber 6 from the inlet 3, the diaphragm 12 is lowered by the load of the spring 24. The pressure regulating valve 10 is separated from the seat 7, and the high pressure fluid flows into the pressure regulating chamber 9 through the flow passage 8.

  When the pressure inside the pressure regulating chamber 10 is increased in the valve regulating state, the diaphragm 12 rises, and when the pressure reaches a predetermined value, the pressure regulating valve 10 comes into contact with the seat 7 and the pressure regulating chamber for high-pressure fluid. 9 to block the inflow. Thereby, the pressure in the pressure regulating chamber 9 is regulated to a predetermined low pressure value, and the regulated fluid is supplied from the outlet 4 to the engine or the like.

The low-pressure fluid in the pressure adjusting chamber 9 flows into the gap 21a through the passage 22, and the pressure in the gap 21a is reduced.
JP 2000-249001 A

  As in the prior art, in the pressure regulating valve 10 in which the rubber O-ring 16 is interposed between the valve shaft 13 and the housing 5 in a pressure-bonded manner and sealed, high-pressure fluid flows from the inlet 3 to the valve storage chamber 6. When the air gap 21a is at a low pressure in the atmospheric state when acting inside, the primary side pressure, which is the high pressure on the inlet 3 side, permeates the periphery of the O-ring 16 in the valve storage chamber 6, and the Applied to the gap 30 between the O-ring 16 and the lower O-ring 19, the pressure in the gap 30 rises, and the gap 30 is lower than the primary pressure but higher than atmospheric pressure. Become high pressure.

  As described above, when there is a mode in which the primary pressure is suddenly released after the inside of the gap 30 reaches a certain high pressure or more, the friction between the O-ring 16, the valve shaft 13 and the housing 5 as in the conventional structure. If the resistance is large, the quasi-high pressure in the gap portion 30 does not suddenly escape from the periphery of the O-ring 16, and the O-ring 16 is pushed up in the direction of the arrow X in FIG. The upper ring 14 of 16 may be pulled upward. Therefore, a structure that suppresses the push-up load is necessary, and there is a problem that the structure is complicated.

Furthermore, the following problems also occur in the conventional structure.
When the high pressure fluid flows in and the pressure regulating valve 10 moves up and down, the valve shaft 13 of the pressure regulating valve 10 moves up and down while rubbing the O ring 16, and the valve shaft 13 receives a large sliding resistance by the O ring 16. .

  Due to this large sliding resistance, when the valve shaft 13 descends, that is, when the pressure regulating valve 10 moves in the valve opening direction, a phenomenon occurs in which the O-ring 16 is compressed downward, and the pressure regulating valve 10 descends. In addition, when the valve shaft 13 is raised, that is, when the pressure regulating valve 10 is moved in the valve closing direction, it is adjusted by the restoring force accumulated in the compressed O-ring 16 as described above. The rise of the pressure valve 10 is promoted.

  Therefore, the pressure regulation characteristic with respect to the flow rate of the high-pressure fluid becomes the characteristic A in FIG. 7 when the pressure regulating valve 10 is lowered, and becomes the characteristic B when the pressure regulating valve 10 is raised, and a large hysteresis C is generated between them. There is a problem of deteriorating pressure characteristics.

  Further, when the valve shaft 13 is moved up and down, a large sliding resistance force is generated on the valve shaft 13 and the O-ring 16, so that the O-ring 16 is quickly worn and the durability is lowered.

  Furthermore, as described above, the rubber O-ring 16 requires the two types of backup rings 17 and 18 having different hardnesses to prevent the O-ring 16 from protruding, which increases the number of parts and the problem of cost. There is.

  Therefore, an object of the present invention is to provide a high-pressure fluid regulator that solves each of the above-mentioned problems.

In order to solve the above problems, the invention according to claim 1 is provided with a pressure regulating valve in a flow path from the high pressure side portion to the low pressure side portion, and the outer peripheral surface of the valve shaft of the pressure regulating valve and the valve shaft are connected to each other. A regulator for high pressure fluid in which a seal member is provided between the valve storage chamber and the inner peripheral surface of the valve storage chamber, and the side opposite to the high pressure side portion is configured as a low pressure side portion with the seal member as a boundary;
A seal body having a transverse cross-sectional shape formed in a U shape having a groove inside, and a metal spring provided in the groove of the seal body and biasing both side pieces of the seal body in an opening direction; The seal member is provided such that the opening of the groove in the seal body opens to the high-pressure part side.

  In the present invention, the seal member is mounted between the outer peripheral surface of the valve shaft and the inner peripheral surface of the valve storage chamber by incorporating a metal spring in the U-shaped seal main body and urging both side pieces of the seal main body in the opening direction. Therefore, even when the valve shaft slides, the sealing performance with the seal member can be ensured.

  Further, when the high-pressure fluid on the high-pressure side acts on the seal member, both side pieces of the seal body in the seal member are urged in the opening direction by the pressure of the high-pressure fluid to further ensure the sealing performance. When the pressure on the high-pressure side suddenly drops while the pressure is in the quasi-high pressure state, the quasi-high-pressure fluid on the low-pressure side presses in the direction to close both side pieces of the seal body in the seal member, resulting in a low pressure. Immediately flows to the high pressure side. Therefore, it is possible to prevent the seal member from being pushed up to the high pressure side portion having a low pressure due to the load of the semi-high pressure fluid in the low pressure side portion.

The invention according to claim 2 is the invention according to claim 1, wherein the seal body is formed of a low sliding resistance material.
The invention according to claim 3 is the invention according to claim 1, wherein the seal body is formed of a fluororesin.

  In the inventions according to claims 2 and 3, the sliding resistance between the valve shaft and the seal body is extremely small when the valve shaft slides. Therefore, the hysteresis of the pressure regulation characteristic between the opening operation and the closing operation of the pressure regulating valve can be reduced, and the pressure regulation characteristic due to the opening / closing operation of the pressure regulating valve is smaller than that of a conventional seal member made of an O-ring. Can be improved.

  Further, since the sliding resistance is small as described above, the wear of the seal member is reduced, the durability is improved, and only one type of backup ring for the seal member is required.

  As described above, according to the first aspect of the present invention, it is possible to prevent the seal member from being pushed up when the fluid on the high-pressure side portion is rapidly lowered. Therefore, in order to prevent the seal member from being pushed up, a structure for pressing the load from the low pressure side portion toward the high pressure side portion becomes unnecessary, which is very effective for cost reduction.

  According to the second and third aspects of the present invention, it is possible to further improve the pressure regulation characteristics and improve the pressure regulation reliability and the pressure regulation performance as compared to the conventional O-ring seal member.

  Further, the wear of the seal member can be reduced to improve the durability, and only one type of backup ring for the seal member is required, so that the number of parts can be reduced and the cost can be reduced.

The best mode for carrying out the present invention will be described based on the embodiment shown in FIGS.
1 is a longitudinal sectional view of a regulator for a high-pressure fluid, FIG. 2 is an enlarged longitudinal sectional view of a main part in FIG. 1, FIG. 3 is an enlarged transverse sectional view of a sealing member, and FIG. 4 is a planar sectional view of the sealing member in FIG. is there.

  In the present invention, since the structure other than the seal structure shown in FIG. 2 is substantially the same as the structure shown in FIGS. 5 and 6, the same parts as those in FIGS. To explain.

  The body 2 of the regulator 1 for high-pressure fluid is formed with an inlet 3 for high-pressure fluid that is a high-pressure side and an outlet 4 that is for a low-pressure side. The valve storage chamber 6, the seat 7, the flow passage 8, and the pressure regulation chamber 9 are circulated and supplied from the outlet 4 to the engine or the like.

  A pressure regulating valve 10 is slidable in the axial direction in the valve storage chamber 6, which is the high pressure side portion of the housing 5, and the pressure regulating valve 10 contacts and separates from the seat 7. Furthermore, a rod 11 protrudes from one end of the pressure regulating valve 10, that is, the upper end in the figure so as to penetrate the flow passage 8, and the tip of the rod 11 is provided in the pressure regulating chamber 9 which is the low pressure side portion. The diaphragm 12 is connected.

  A valve shaft 13 protrudes from the other end of the pressure regulating valve 10, that is, the lower end in the drawing, and the valve shaft 13 is stored in the valve storage chamber 6. A ring 14 is fitted between the inner peripheral surface of the valve storage chamber 6 and the outer peripheral surface of the valve shaft 13, and a spring 15 is interposed between the ring 14 and the pressure regulating valve 10 to attach the spring 15. The pressure regulating valve 10 is constantly urged toward the seat 7 by the force.

  A stopper 21 is provided at the lower part of the housing 5, and a gap 21 a is formed in the stopper 21 so that the lower end of the valve shaft 13 is slidably fitted. The gap portion 21a communicates with the outlet 4 and the low pressure side of the pressure regulating chamber 9 through the passage 22, and the gap portion 21a is a low pressure side portion.

  Between the valve storage chamber 6 that is the high-pressure side and the gap 21a that is the low-pressure side, an O-ring 19 is disposed on the gap 21a side, and is positioned on the valve storage chamber 6 side. A seal member 50 is provided.

  Therefore, the low pressure side portion including the gap portion 21a is formed on the side opposite to the high pressure side portion including the valve storage chamber 6 with the seal member 50 as a boundary.

  The O-ring 19 is provided in close contact with the outer peripheral surface of the valve shaft 13 and the inner peripheral surface of the housing 5.

The seal member 50 will be described in detail with reference to FIGS.
The seal member 50 includes a seal body 51 and a metal spring 52 provided in the seal body 51. As shown in FIG. 4, the seal body 51 has an endless ring shape as shown in FIG. 4, and the cross-sectional shape is formed in a U shape with a groove 53 having an upper opening at the center as shown in FIG. Further, the seal body 51 is formed so that its outer diameter is slightly larger than the inner diameter R1 of the housing 5 and its inner diameter is slightly smaller than the outer diameter of the valve shaft 13 in a normal state before the mounting. Further, the seal body 51 is formed of rubber, resin, or the like, but is preferably formed of a low sliding resistance material having a very small sliding resistance (friction coefficient). In addition, it is made of a fluororesin such as PTFE which is excellent in heat resistance, cold resistance, chemical resistance, wear resistance and the like.

  The metal spring 52 has an endless ring shape as shown in FIG. 4 and a U-shape in which a cross-sectional shape is formed with a groove 54 having an upper opening at the center as shown in FIG. The both side pieces 52a and 52b have elasticity in the radial direction. Further, the metal spring 52 is fitted in the groove 53 of the seal body 51. In the normal state before the seal member 50 is mounted, the outer diameter of the seal body 51 is reduced by the side pieces 52a and 52b. The outer piece 51a and the inner piece 51b are pushed open so that the inner diameter R1 is slightly larger than the inner diameter R1 and the inner diameter of the seal body 5 is slightly smaller than the outer diameter of the valve shaft 13. Further, the metal spring 52 is made of stainless steel.

  Therefore, when the seal member 50 is mounted between the inner peripheral surface of the housing 5 and the outer peripheral surface of the valve shaft 13 as shown in FIGS. 1 and 2, both the pieces 51 a and 51 b of the seal body 51 and the two pieces of the metal spring 52. 52 a and 52 b are in a closed state from the normal state, the outer piece 51 a of the seal body 51 is in pressure contact with the housing 5, and the inner piece 51 b is in pressure contact with the valve shaft 13.

  A small-diameter step portion 5a is formed in the lower portion of the seal member 50, that is, the housing 5 side on the O-ring 19 side, and one resin backup ring 55 is disposed on the step portion 5a. The seal member 50 is provided on the backup ring 55.

  With the above-described configuration, the high-pressure fluid inlet 3 and the valve storage chamber 6 side become the primary high-pressure portion, the gap 21 a side becomes the secondary low-pressure portion, and these are separated by the seal member 50.

Next, the operation will be described.
With the above configuration, when the pressure in the pressure regulating chamber 9 decreases to a predetermined value or less in a state where the high-pressure fluid acts on the valve storage chamber 6 from the inlet 3, the diaphragm 12 is lowered by the load of the spring 24. The pressure regulating valve 10 is separated from the seat 7, and the high pressure fluid flows into the pressure regulating chamber 9 through the flow passage 8.

  When the pressure inside the pressure regulating chamber 10 is increased in the valve regulating state, the diaphragm 12 rises, and when the pressure reaches a predetermined value, the pressure regulating valve 10 comes into contact with the seat 7 and the pressure regulating chamber for high-pressure fluid. 9 to block the inflow. Thereby, the pressure in the pressure regulating chamber 9 is regulated to a predetermined low pressure value, and the regulated fluid is supplied from the outlet 4 to the engine or the like.

  The secondary low-pressure fluid in the pressure regulating chamber 9 and the outlet 4 acts on the gap 21 a through the flow path 22.

  In the above operation, when the pressure on the primary side, that is, the pressure on the valve storage chamber 6 side is low, both side pieces 51 a and 51 b of the seal body 51 in the seal member 50 are moved to the housing by the biasing force in the opening direction of the metal spring 52. When the pressure on the primary side, that is, the pressure on the valve storage chamber 6 side is higher than the secondary pressure on the gap 21a side, The high-pressure fluid acts in the grooves 53 and 54 of the seal member 50, and the both-side pieces 51a and 51b of the seal body 51 are spread toward the housing 5 and the valve shaft 13 side by the pressure of the high-pressure fluid itself to perform a sealing action.

  If the gap 21a is low when the high-pressure fluid flows in from the inlet 3, the primary pressure, which is high on the inlet 3, passes through the periphery of the seat member 50 in the valve storage chamber 6, and the seat Applied to the gap 30 between the member 50 and the O-ring 19, the pressure of the gap 30 rises, and the gap 30 becomes a quasi-high pressure portion that is lower than the primary side pressure but higher than the atmospheric pressure. .

  As described above, when there is a mode in which the primary side pressure is suddenly released after the inside of the gap portion 30 reaches a certain high pressure or more, the fluid in the gap portion 30 that has become a quasi-high pressure portion as described above, Due to the pressure difference from the pressure, it passes through the inner and outer peripheral parts of the seat member 50 to the valve housing chamber 6 side. At this time, both side pieces 51a and 51b of the seat body 51 in the seat member 50 are bent toward the groove 53 side by the permeating high pressure fluid pressure, and the flow of fluid from the gap portion 21a to the valve housing chamber 6 side is smooth. This prevents the seat member 50 from being pushed up toward the valve storage chamber 6 by the semi-high pressure in the gap 30. Even in the evaluation in which the primary side was depressurized after leaving the primary side pressure high for a long time, the conventional O-ring 16 pulled the ring 14 upward, whereas in the sealing member 50 of the present invention, The ring 14 did not come off. Therefore, the present invention eliminates the need for a conventional structure for suppressing the thrust load, and has a feature that the structure can be simplified as compared with the conventional structure.

  Further, in the sealing state as described above, when the valve shaft 13 moves up and down by the pressure regulating action of the pressure regulating valve 10, the seal body 51 in the seal member 50 is formed of a fluororesin having an extremely small sliding resistance. Therefore, the valve shaft 13 does not receive a large sliding resistance even when it is raised and lowered. Therefore, unlike the conventional O-ring 16, the lowering of the valve shaft 13 is not suppressed, and the rising is not promoted when the valve shaft 13 is raised.

  Therefore, the pressure regulation characteristic with respect to the flow rate of the high-pressure fluid becomes the characteristic D shown in FIG. 7 when the pressure regulating valve 10 is lowered, and becomes the characteristic E shown in FIG. Is smaller than the hysteresis C of the conventional structure.

  As a result of the experiment, the hysteresis F of the present invention was reduced by about 30% compared to the hysteresis C of the conventional structure.

  Therefore, deterioration of the pressure regulation characteristics can be improved, and durability against wear of the seal member 50 can be improved as compared with the conventional O-ring 16.

  Further, by using the seal member 50 as described above, one type of backup ring 55 may be used, compared to the case where two types of backup rings 17 and 18 are provided as in the conventional structure. The number of parts of the backup ring could be reduced. That is, in the conventional O-ring 16, two types of backup rings 17 and 18 having different hardnesses are required to prevent the O-ring 16 from protruding, but this is not necessary in the present invention. It was confirmed from the actual measurement results that the single backup ring 55 is sufficient.

The longitudinal cross-sectional view of the regulator for high pressure fluid which shows the Example of this invention. FIG. 2 is an enlarged longitudinal sectional view of a main part in FIG. 1. The expanded cross-sectional view of the sealing member in FIG. FIG. 3 is a plan sectional view of the seal member shown in FIG. 2. The longitudinal cross-sectional view which shows the conventional high voltage | pressure regulator. The expanded longitudinal cross-sectional view of the principal part in FIG. The figure which shows the hysteresis of the pressure regulation characteristic of this invention and a conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Inlet of high pressure fluid 4 Outlet 6 Valve storage chamber which is a high pressure side part 7 Sheet | seat 10 Pressure regulation valve 13 Valve shaft 50 Seal member 51 Seal main body 51a, 51b Both-side piece 52 Metal spring 53 Groove

Claims (3)

A pressure regulating valve is provided in the flow path from the high pressure side portion to the low pressure side portion, and a seal member is provided between the outer peripheral surface of the valve shaft of the pressure regulating valve and the inner peripheral surface of the valve storage chamber for storing the valve shaft. , A high-pressure fluid regulator in which the side opposite to the high-pressure side is configured as a low-pressure side with the seal member as a boundary,
A seal body having a transverse cross-sectional shape formed in a U shape having a groove inside, and a metal spring provided in the groove of the seal body and biasing both side pieces of the seal body in an opening direction; The high-pressure fluid regulator is characterized in that the seal member is provided so that the opening of the groove in the seal body opens to the high-pressure part side.   The high-pressure fluid regulator according to claim 1, wherein the seal body is formed of a low sliding resistance material.   The high-pressure fluid regulator according to claim 1, wherein the seal body is formed of a fluororesin.

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