JPH11270718A - Pressure reducing valve for gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an offset load from occurring when a diaphragm is assembled by providing a storage hole opened with an outer end where a coil spring can be inserted or removed on a cover fastened to a body, and providing a recess for receiving the end section of the coil spring on an adjusting screw screwed to an opening section at the outer end of the storage hole. SOLUTION: A storage hole 118 opened with an outer end where a coil spring 117 can be inserted or removed on a cover 91 is provided coaxially with the axis of a valve hole 104. An adjusting screw 132 screwed to the outer end opening section of the storage hole 118 is provided with a recess 132 a receiving the whole end section of the coil spring 117 on the opposite side to a diaphragm 93, and the coil spring 117 is not required to be received by a retainer. When the peripheral edge section of the diaphragm 93 is pinched between a body 34 and the cover 91, the coil spring 117 can be extracted from the cover 91, and the diaphragm 93 can be prevented from being applied with an offset load. The diaphragm 93 can be surely seated without generating a drift, and a defective pressure adjustment can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas pressure reducing valve, and more particularly, to a gas pressure reducing valve having a diaphragm which can be seated on a valve seat having a valve hole formed at the center thereof, which communicates with a pressure reducing chamber formed between a body and a diaphragm. And a gas pressure reducing valve in which a coil spring is housed in a spring chamber formed between the cover and the diaphragm, and an adjusting screw for adjusting the spring load of the coil spring is threadably engaged with the cover. .

[0002]

2. Description of the Related Art Conventionally, such a gas pressure reducing valve is known, for example, from Japanese Patent Application Laid-Open No. 6-249076.

[0003]

However, in the prior art described above, the outer end of the cylindrical portion provided in the cover for accommodating the coil spring is closed by an end wall, and the end portion can freely move back and forth on the end wall. The retainer against which the inner end of the threaded adjustment screw abuts receives the end of the coil spring opposite to the diaphragm, so the cover is attached to the body so that the peripheral edge of the diaphragm is sandwiched between the body and the cover. At the time of fastening, the coil spring, the retainer, and the adjusting screw must be incorporated at the same time, and the fastening operation needs to be performed while applying a force overcoming the spring force of the coil spring to the cover. In addition, when fastening the cover to the body, it is necessary to tighten the bolts at multiple locations in the circumferential direction of the cover, but it is impossible to tighten multiple bolts at the same time. Eccentric load is likely to be applied, and the diaphragm may not be properly sandwiched between the cover and the body, and may shift.
Due to the displacement of the diaphragm, the seating of the valve body on the valve seat becomes incomplete, and there is a possibility that poor pressure regulation occurs. In addition, since it is necessary to interpose a retainer between the adjusting screw and the coil spring, the number of parts increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and prevents an eccentric load from acting on a diaphragm when the diaphragm is assembled so that the diaphragm is not displaced and assembled, and the number of parts is reduced. It is an object of the present invention to provide a pressure reducing valve for a gas which enables the above.

[0005]

To achieve the above object, according to the first aspect of the present invention, a peripheral portion of a diaphragm is sandwiched between a body and a cover fastened to the body, and the diaphragm and the cover are fixed to the body. A valve body, which can be seated on a valve seat having a valve hole opened at a central portion communicating with a pressure reducing chamber formed between the bodies, is connected to a central portion of the diaphragm, and is formed between the cover and the diaphragm. A coil spring for urging the diaphragm in a direction to reduce the volume of the decompression chamber is housed, and an adjusting screw for adjusting the spring load of the coil spring in accordance with the axially advanced / retracted position is capable of moving forward and backward to the cover. In the gas pressure reducing valve to be screwed, the cover is provided with a storage hole having an outer end opened so that the coil spring can be inserted and removed, and is provided coaxially with the axis of the valve hole. The adjustment screw to be screwed into the opening,
An end of the coil spring opposite the diaphragm is received.

[0006] According to such a configuration, the end of the coil spring opposite to the diaphragm is directly received by the recess provided in the adjusting screw, so that the number of parts can be reduced by eliminating the need for a retainer. . And the adjusting screw is
Since the coil spring can be stored and screwed into the outer end opening of the storage hole provided in the cover, when the peripheral edge of the diaphragm is sandwiched between the body and the cover, the coil spring is taken out from the cover. The cover can be fastened to the body by avoiding the application of an eccentric load to the diaphragm, so that the diaphragm is prevented from being displaced and the valve body can be securely seated on the valve seat. It is possible to prevent the occurrence of poor pressure regulation.

[0007] The invention according to claim 2 provides the above-described claim 1.
In addition to the configuration of the invention described in the above, the adjusting screw is provided with a guide portion for fitting an end of the coil spring opposite to the diaphragm, and according to this configuration, the coil spring is covered. When the coil spring is housed in the housing and compressed by the adjusting screw, the end of the coil spring opposite to the diaphragm can be guided by the guide portion, and the inclination of the coil spring can be prevented.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIGS. 1 to 15 show an embodiment of the present invention. FIG. 1 is a view schematically showing the structure of a fuel supply device for a vehicle, FIG. 2 is a side view of a regulator, and FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, FIG.
FIG. 6 is a sectional view taken along line 5-5 of FIG. 4, FIG. 6 is an enlarged longitudinal sectional view of the solenoid shut-off valve, FIG. 7 is a view showing suction characteristics of the electromagnetic shut-off valve, FIG. 8 is an enlarged sectional view taken along line 9-9 of FIG. 8, FIG. 10 is an enlarged view of a main part of FIG. 8, FIG. 11 is a view showing a pressure reducing characteristic of the primary pressure reducing valve according to the environmental temperature, and FIG. FIG. 13 is a diagram showing hysteresis characteristics depending on the number of rings, FIG. 13 is an enlarged longitudinal sectional view of a secondary pressure reducing valve,
14 is a sectional view taken along line 14-14 of FIG. 13, and FIG.
FIG. 15 is a vertical sectional side view showing only a cap cut along line 15-15 of FIG.

Referring first to FIG. 1, compressed natural gas (Compre
ssed Natural Gas (hereinafter referred to as CNG) is stored in one or more CNG tanks 20.
/ Cm ² are stored at a high pressure, and the container shut-off valves 21... Provided in the CNG tanks 20... Are commonly connected to the filling port 22 via a check valve 23.
Commonly connected to the manual shut-off valve 24, each container shut-off valve 21 ...
And a line 25 between the manual shutoff valve 24 and the pressure sensor 2
6 and a temperature sensor 27 are additionally provided.

When the container shut-off valves 21 and the manual shut-off valves 24 are opened, the CNG from the CNG tanks 20
The regulator R is connected via a line 28 provided with an oil filter 41 for removing oil that may be mixed in when filling the CNG into the G tanks 20 by the compressor.
CNG, which has been reduced to a pressure of ² to 3 kg / cm ² by the regulator R, is guided to the injector 29 of the engine E via the pipe 30. Thus, a temperature sensor 31 and a pressure sensor 32 are attached to the conduit 30.

Referring to FIGS. 2 to 5 together, the regulator R includes a common body 34 having a hot water passage 33.
, A filter 35, an electromagnetic shut-off valve 36, a primary pressure reducing valve 37,
A secondary pressure reducing valve 38, a relief valve 39 and a thermostat 40 are provided.

The filter 35 removes impurities contained in CNG introduced through the pipe 28 from the manual shut-off valve 24. The electromagnetic shut-off valve 36 turns off the filter 35 and the engine 35 when the operation of the engine E is stopped. It functions to shut off the primary pressure reducing valve 37 to stop the supply of CNG.

The primary pressure reducing valve 37 operates to reduce the pressure of CNG from 250 to 10 kg / cm ² from the CNG tank 20 to, for example, 6 to 7 kg / cm ² , and the secondary pressure reducing valve 38 The CNG from the pressure reducing valve 37 is operated to reduce the pressure to, for example, ² to 3 kg / cm ² , and the CNG from the secondary pressure reducing valve 38 is guided to the injector 29 via the pipe 30.

The relief valve 39 is connected between the primary pressure reducing valve 37 and the secondary pressure reducing valve 38, and the CNG that is reduced in pressure by the primary pressure reducing valve 37 and guided to the secondary pressure reducing valve 38 is:
For example, a preset valve opening pressure, for example, 16.5 kg /
Acts to open and release CNG to atmosphere when it rises above cm ² .

Further, in order to prevent the temperature of the body 34 from excessively lowering due to the pressure reducing action of the primary and secondary pressure reducing valves 37 and 38, the engine E coolant is supplied to the hot water passage 33 of the body 34. Is introduced,
The thermostat 40 is disposed in the body 34 on the return side of the engine cooling water from the hot water passage 33 to the engine E side, and closes when the engine cooling water flowing through the hot water passage 33 exceeds, for example, 80 degrees. Body 34
Works to prevent the temperature from rising too high.

Hereinafter, the configurations and operations of the filter 35, the electromagnetic shutoff valve 36, the primary pressure reducing valve 37, the secondary pressure reducing valve 38, the relief valve 39 and the thermostat 40 will be sequentially described.

[Filter 35]; Paying particular attention to FIG.
A concave portion 43 is formed on a side portion of the body 34 at a middle portion in the vertical direction.
Is provided at the outer end opening of the recess 43.
4 is an annular sealing member 4 between its inner end and body 34
5 is connected to the outer end of the pipe joint 44 by being screwed in such a manner as to sandwich C5 and guiding CNG from the manual shutoff valve 24. The filter 35 is fitted in the recess 43 so as to leave a space between the recess 43 and the inner end of the pipe joint 44.
A filter 35 is provided between the filter 35 and the pipe fitting 44.
A spring 46 is provided that exerts an elastic force to press the inner surface of the recess 43 against the inner end closing portion.

Between the outer periphery of the filter 35 fitted in the recess 43 and the body 34, an annular unpurified chamber 47 communicating with the inside of the pipe fitting 44 is formed. A passage 49 leading to the purification chamber 48 is provided. Thus, impurities contained in CNG guided through the conduit 28 pass through the filter 35 from the unpurified chamber 47, flow into the purification chamber 48, and are further guided to the passage 49.

[Electromagnetic shut-off valve];
The body 3 is positioned at an upper and lower position corresponding to the filter 35 at a position circumferentially spaced from the screwed position of the pipe joint 44.
The electromagnetic shut-off valve 36 is attached to the side of 4.

The electromagnetic shut-off valve 36 includes a coil assembly 50
And a guide cylinder 51 made of a nonmagnetic material, one end of which is inserted into the coil assembly 50 and the other end of which is fixed to the body 34, and is fixed to the guide cylinder 51 so as to close one end of the guide cylinder 51. A fixed core 52, a plunger 53 slidably fitted in the guide cylinder 51 facing the fixed core 52, a return spring 54 provided between the fixed core 52 and the plunger 53, and a coil assembly 50. A magnetic metal-made solenoid housing 55 fastened to the fixed core 52 so as to cover it; a magnetic support frame 56 screwed to the body 34 so as to sandwich the coil assembly 50 between the solenoid housing 55; And a valve member 57 held by the plunger 53 on the side opposite to the first side.

The coil assembly 50 is made up of a synthetic resin bobbin 59 having a center hole 58 and a coil 60 wound around the bobbin 59 covered by a coating portion 61 made of synthetic resin. A coupler 61a facing a pair of connection terminals 62 connected to the coil 60 is integrally provided on the body 34 side of the covering 61 so as to protrude outward. Is connected to a conducting wire (not shown).

The body 34 has a small-diameter hole 63 with an inner end closed.
And a large-diameter hole 64 which is larger in diameter than the small-diameter hole 63 and coaxially communicates with the outer end of the small-diameter hole 63.
Are formed between each other. On the outer surface of the other end side of the guide cylinder 51 for inserting one end side into the center hole 58 of the bobbin 59, a flange portion 51a for making the outer peripheral surface close to and facing the inner surface of the large-diameter hole 64 projects radially outward. The other end of the guide tube 51 is inserted into the large-diameter hole 64 so as to sandwich the annular seal member 66 between the flange portion 51a and the step portion 65.

The magnetic support frame 56 surrounds a portion of the guide cylinder 51 protruding from the coil assembly 50 toward the body 34 and abuts against the end surface of the coil assembly 50 on the body 34 side; A cylindrical portion 56b which is integrally connected to the inner periphery of the portion 56a and surrounds the guide cylinder 51. When the cylindrical portion 56b is screwed into the large-diameter hole 64, the magnetic support frame 56 is attached to the body 34. Assembled. In addition, the seal member 66 and the flange 51a are sandwiched between the step 65 and the distal end of the cylindrical portion 56b.
The guide cylinder 51 is also fixed to the body 34.

The fixed core 52 is formed of a magnetic metal in the shape of a rod having a circular cross section, and its inner end is fitted to one end of the guide tube 51 so that its outer end protrudes from one end of the guide tube 51. In this state, it is fixed to the guide cylinder 51 by welding or the like. At this time, the flange portion 51 protruding radially outward
Since a is provided on the other end side of the guide cylinder 51,
Guide tube 51 of magnetic support frame 56 and coil assembly 50
The guide tube 51 must be attached from one end side of the guide tube 51, that is, from the fixed core 52 side. In order to prevent the fixing portion of the guide tube 51 and the fixed core 52 from protruding from the outer surface of the guide tube 51, the fixed The outer diameter of the projecting portion of the core 52 from the guide cylinder 51 is set smaller than the outer diameter of the guide cylinder 51. Therefore, the center hole 5 in the coil assembly 50 is
An annular gap 67 is formed between the inner surface on one end side of 8 and the outer peripheral surface of the fixed core 52. Fixed core 5
The outer end surface of the coil assembly 50 is disposed at substantially the same position as the one end surface of the coil assembly 50 along the axis of the guide cylinder 51.

The solenoid housing 55 is integrally formed with a cylindrical portion 55a surrounding the coil assembly 50 and an end plate portion 55b connected to one end of the cylindrical portion 55a, and is formed in a bottomed cylindrical shape. The central portion of the end plate portion 55b is in contact with the outer end surface of the fixed core 52. Moreover, fixed core 5
2 has a screw shaft portion 52a projecting outward from the outer end face thereof.
Are coaxially and integrally connected, and the end plate portion 55b
The insertion hole 68 through which the screw shaft portion 52a is inserted
Is provided. The end plate portion 55 of the screw shaft portion 52a
A cap nut 70 is screwed into the protruding portion from the end portion 55b through a washer 69 between the protruding portion and the outer surface of the end plate portion 55b.
By tightening the cap nut 70, the end plate 55 b, that is, the center of the closed end of the solenoid housing 55 is fastened to the fixed core 52.

By fastening the solenoid housing 55 to the fixed core 52, the coil assembly 50 is sandwiched between the end plate 55b of the solenoid housing 55 and the ring plate 56a of the magnetic support frame 56. However, in order to prevent an excessive load from acting on the coil assembly 50 due to the fastening of the solenoid housing 55, one end surface of the coil assembly 50 has an annular shape that resiliently contacts the inner surface of the end plate portion 55b. The elastic member 71 is mounted, and the coil assembly 50 is mounted.
An annular elastic member 72 is sandwiched between the inner periphery of the other end of the magnetic member and the magnetic support frame 56.

On the inner surface of the end plate portion 55b of the solenoid housing 55, a magnetic path forming member 73 made of magnetic metal is provided.
It is fixed by spot welding or the like. This magnetic path forming member 7
3 includes a ring plate portion 73a surrounding the fixed core 52 and abutting against the inner surface of the end plate portion 55b, and a cylindrical portion 73b having one end coaxially and integrally connected to the inner periphery of the ring plate portion 73a. Prepare. The cylindrical portion 73b surrounds the fixed core 52 by enabling magnetic coupling with the fixed core 52, and the other end of the cylindrical portion 73b is formed between the coil assembly 50 and the fixed core 52. It is inserted into the annular gap 67.

At the other end of the cylindrical portion 55a of the solenoid housing 55, a notch 74 is provided for projecting the coupler portion 61a provided integrally with the covering portion 61 of the coil assembly 50 to the outside. By the way, a disk-shaped flange portion 77 for mounting the secondary pressure reducing valve 38 is integrally provided on the body 34 above the electromagnetic shut-off valve 36 so as to project outward.
A surface on the side of the electromagnetic shut-off valve 36 forms a flat regulating wall 76 facing the other end of the cylindrical portion 55a in the solenoid housing 55 of the electromagnetic shut-off valve 36. On the other hand, the cylindrical portion 5
At the other end of 5a, a pair of engaging claws 75, 75 protruding toward the regulating wall 76 side are provided integrally, and when the engaging claws 75, 75 are engaged with the regulating wall 76, The rotation of the solenoid housing 55 around the axis of the screw shaft portion 52a of the fixed core 52 is prevented.

The other end of the guide cylinder 51 is fixed to the body 34 in a state of being inserted into the large-diameter hole 64, and the guide cylinder 5
1, the main valve chamber 78 is formed between the inner end closed portion of the small-diameter hole 63 of the body 34 and the other end of the guide cylinder 51 and the plunger 53. Is done. Further, a passage 49 communicating with the purification chamber 48 of the filter 35 is communicated with the main valve chamber 78, and CNG purified by the filter 35 is supplied to the main valve chamber 7
8 is introduced.

A passage 79 is provided in the body 34 so as to open at the center of the small-diameter hole 63 at the inner end closing portion. The main passage is provided so as to surround the opening end of the passage 79 to the main valve chamber 78. An annular valve seat 80 slightly protruding toward the valve chamber 78 is provided on the body 34.

The valve member 57 includes a pilot valve portion 57 a at one end formed in a disk shape having a tapered surface having a smaller diameter toward the plunger 53 at one end, and an inner end closing portion of the small diameter hole 63. A main valve portion 57b on the other end, which is formed in a disk shape and faces the opposite side, is integrally connected via a connecting cylinder portion 57c that forms a step between the two valve portions 57a and 57b. The diameter of the pilot valve portion 57a is the same as that of the main valve portion 57b.
Is set smaller than the diameter of. In the center of the valve member 57, a first passage 81 that is always in communication with the passage 79,
A second passage 82 that opens at the center of one end face of the pilot valve portion 57 a through the passage 81 is provided coaxially, and the second passage 82 is formed to have a smaller diameter than the first passage 81.

At the end of the plunger 53 facing the main valve chamber 78, a recess 83 into which the pilot valve portion 57a is inserted is provided. The pilot valve portion 57a is a C-shaped fixed to the other end of the plunger 53. Pilot valve chamber 85 is loosely inserted into concave section 83 so as to be prevented from being detached from concave section 83 by retaining ring 84, and is provided between pilot valve section 57 a and plunger 53 to communicate with main valve chamber 78.
Is formed. Further, a rubber seal 86 for closing the opening of the second passage 82 to the pilot valve chamber 85 when the central portion of the one end face of the pilot valve portion 57a is seated is embedded in the central portion of the closed end of the concave portion 83. Thus, the retaining ring 84
The pilot valve portion 57a is fixed to the plunger 53 at a position where the pilot valve portion 57a can move relative to the plunger 53 between the closed end of the concave portion 83 and the retaining ring 84 in the axial direction.

In the main valve portion 57b, a small-diameter hole 63 is formed.
An annular rubber seal 87 that sits on the valve seat 80 and blocks the space between the main valve chamber 78 and the passage 79 is buried in the surface facing the closed end.

In such an electromagnetic shut-off valve 36, when the engine E is stopped, the degaussing of the coil 60 causes the plunger 5 to move.
3 moves in a direction away from the fixed core 52 by the spring force of the return spring 54, and the rubber seal 87 of the main valve portion 57b is moved.
Is seated on the valve seat 80 to shut off the space between the main valve chamber 78 and the passage 79, and the pilot valve portion 57 a is seated on the rubber seal 86 and the pilot valve chamber 85 and the passage 79.
The supply of high-pressure CNG to the passage 79 is stopped.

On the other hand, when the coil 60 is excited when the operation of the engine E is started, first, the plunger 53 moves to the fixed core 52 side by moving the pilot valve portion 57 a away from the rubber seal 86, and through the first passage 81. The second passage 82 communicating with the passage 79 communicates with the pilot valve chamber 85. As a result, CNG gradually flows from the main valve chamber 78 to the passage 79 through the pilot valve chamber 85, the second passage 82, and the first passage 81, whereby the main valve chamber 78 and the passage 79 The difference in pressure acting from the side is reduced. When the electromagnetic force of the coil 60 overcomes the differential pressure acting on the main valve portion 57b, the plunger 53
Side to the rubber seal 8 of the main valve portion 57b.
7 is separated from the valve seat 80 and the passage 79 from the main valve chamber 78.
CNG will flow to.

Further, in the electromagnetic shut-off valve 36, the center of the end plate 55b of the solenoid housing 55 is fixed to the fixed core 52.
, But the solenoid housing 5
5, an engagement claw 7 provided integrally with the cylindrical portion 55a
5 and 75 are engaged with the regulating wall 76 of the body 34, so that even if the solenoid housing 55 rotates about the fastening portion of the end plate portion 55b to the fixed core 52, the engagement claws 75 and 75 are The engagement with the regulating wall 76 prevents the rotation of the solenoid housing 55. Therefore, the rotation of the solenoid housing 55 can be prevented with a simple structure that does not require increasing the tightening strength of the solenoid housing 55 to the fixed core 52, and the cutting provided on the cylindrical portion 55 a of the solenoid housing 55 can be prevented. The circumferential position of the coupler portion 61a protruding outward from the notch 74 is prevented from being deviated from the normal position, and an undesired external force does not act on the conductor connected to the coupler portion 61a. Further, the regulating wall 76 is a surface of the disc-shaped flange portion 77 on the electromagnetic shut-off valve 36 side for attaching the secondary pressure reducing valve 38 to the body 34, and it is not necessary to form the regulating wall 76 in particular. Connect the solenoid housing 55 to the body 3
4 can be arranged as close to the center as possible, which can contribute to downsizing of the regulator R.

An annular gap 67 is formed between the outer surface of the fixed core 52 and the inner surface of the center hole 58 of the coil assembly 50. The annular gap 67 is formed at the closed end of the solenoid housing 55, that is, at the inner surface of the end plate 55b. Ring plate 73a to be in contact
And one end is coaxially and integrally connected to the inner periphery of the ring plate portion 73a, and the fixed core 5
Path forming member 73 having a cylindrical portion 73b surrounding
Is fixed to the solenoid housing 55 such that the other end of the cylindrical portion 73b is inserted into the gap 67. By disposing such a magnetic path forming member 73 between the solenoid housing 55 and the fixed core 52,
The magnetic path area between the solenoid housing 55 and the fixed core 52 is the area corresponding to the outer end face of the fixed core 52, and the area of the outer peripheral surface of the fixed core 52 surrounded by the cylindrical portion 73b of the magnetic path forming member 73. Is added, and the magnetic path area between the solenoid housing 55 and the fixed core 52 can be made sufficiently large.

As a result, the one with the annular gap 67 left shows the suction force characteristic shown by the broken line in FIG.
When the magnetic path forming member 73 is inserted into the gap 67,
As shown by the solid line in FIG. 7, excellent suction characteristics can be obtained.

[Primary pressure reducing valve 37]; In FIG. 8, the valve housing 90 of the primary pressure reducing valve 37 is composed of a lower portion of the body 34 and a cover 91 fastened to the lower surface of the body 34 with a plurality of bolts 92. The body 34
A peripheral portion of the diaphragm 93 is sandwiched between the lower surface of the diaphragm 93 and the cover 91.

On the lower surface of the body 34, a diaphragm 93 is provided.
A concave portion 95 forming a decompression chamber 94 is provided between the diaphragm 9 and the diaphragm 9.
A circular raised portion 96 protruding to the third side is provided.

The body 34 is provided with a bottomed mounting hole 97 having a lower end opened toward the decompression chamber 94 and having a closed upper end so as to extend up and down. 1st opening of lower end at the center of lower end
The hole 97a and a second hole 97b having a diameter smaller than that of the first hole 97a and having a lower end coaxially connected to an upper end of the first hole 97a.
A third hole 97c having a diameter smaller than that of the second hole 97b and having a lower end coaxially connected to an upper end of the second hole 97b; and a third hole 97c having a diameter smaller than that of the third hole 97c. Fourth hole 97d whose lower end is coaxially connected and whose upper end is closed
And a passage 7 for guiding CNG from the electromagnetic shut-off valve 36.
9 is opened in the inner surface of the second hole 97b.

In the first hole 97a of the mounting hole 97, a cylindrical valve seat member 98 is provided with an annular seal member 99 between the first and second holes 97a and 97b.
Are screwed together. That is, a female screw 100 is formed on the inner surface of the lower part of the first hole portion 97 a in the mounting hole 97, and the valve seat member 98 is screwed into the female screw 100.

Further, on the end face of the valve seat member 98 on the side of the pressure reducing chamber 94, a plurality of, for example, four grooves 101 extending in the radial direction of the valve seat member 98 in a plane perpendicular to the axis of the mounting hole 97.
Are protruded from each other, and the grooves 101 are arranged in a cross shape. When the valve seat member 98 is screwed into the female screw 100, a tool (not shown) can be engaged with the grooves 101 arranged in a cross shape to rotate the valve seat member 98. The member 98 can be easily attached to the body 34.

A valve chamber 103 communicating with the passage 79 is formed between the valve seat member 98 and the upper end closing portion of the mounting hole 97. Further, the valve seat member 98 integrally includes an inward flange 98a that protrudes radially inward at an end portion on the decompression chamber 94 side, and a valve that communicates with the decompression chamber 94 on the inner periphery of the inward flange 98a. A hole 104 is formed, and a tapered valve seat 105 facing the valve chamber 103 with the valve hole 104 opened at the center is formed on the inner surface of the inward flange 98a.

Referring also to FIG. 9, a valve body 106 made of synthetic resin that can be seated on the valve seat 105 is housed in the valve chamber 103, and the valve body 106 is disposed coaxially with the valve hole 104. Is fixed to the valve shaft 107.

The valve body 106 has a tapered valve seat 105.
One end face facing the valve seat 105 is formed in a cylindrical shape with a tapered shape so as to be seated on the valve shaft 105.
Fixed to In addition, a pair of O-rings 108, 108 that resiliently come into contact with the inner surface of the valve body 106 are mounted on the outer surface of the valve shaft 107 at positions spaced apart in the axial direction.

One end of the valve shaft 107 is provided between the bearing 1 and the inner surface of the third hole 97c of the mounting hole 97.
09 allows the body 34 to move in the axial direction and is supported by the body 34. Further, on the outer surface of the valve body 106, there are provided guide portions 110, which are in sliding contact with the inner surface of the valve seat member 98 at a plurality of positions, for example, four positions, at equal intervals in the circumferential direction. Flow passages 111 extending along the axial direction of the valve shaft 107 are formed between the body 106 and the valve seat member 98.

A retainer 112 for holding the bearing 109 between the mounting hole 97 and the step between the third and fourth holes 97c and 97d is provided with the second and third holes 97.
b, 97c, and the retainer 1
A spring 113 is contracted between the valve body 12 and the valve body 106.

A spring chamber 116 is formed between the cover 91 and the diaphragm 93, and a coil spring 117 for urging the diaphragm 93 toward the pressure reducing chamber 94 is formed in the spring chamber 116.
Is stored.

The cover 91 is provided with a storage hole 118 extending coaxially with the valve hole 104 so as to open the outer end. The storage hole 118 is formed in the screw hole 11 on the axially outward side.
8a and a sliding hole 118 on the inner side in the axial direction which has a larger diameter than the screw hole 118a and is coaxial with the screw hole 118a.
b. Moreover, the inner diameter of the storage hole 118 is set to such an extent that the coil spring 117 can be inserted and removed.

Referring also to FIG. 10, the diaphragm 9
A first diaphragm retainer 1 integrally having a cylindrical portion 119a that penetrates the center of the diaphragm 93 and protrudes toward the spring chamber 116 on a surface facing the decompression chamber 94 at the center of the third.
19 abuts on the spring chamber 1 at the center of the diaphragm 93.
On the surface facing the 16 side, the inner periphery is engaged with an annular step portion 121 provided on the outer surface of the cylindrical portion 119a, and the diaphragm 9 is
The second diaphragm retainer 120 that sandwiches the center of the third diaphragm 3 with the first diaphragm 119 is in contact with the first diaphragm 119.

On the other hand, a cylindrically formed piston 123 is fitted in the sliding hole 118b of the storage hole 118 so as to be able to slide in the axial direction within a limited range. At the end on the 93 side, a ring plate-shaped contact plate 123a that contacts the annular step portion 122 and the second diaphragm retainer 120 provided on the outer surface of the cylindrical portion 119a, and the cylindrical portion 119a are surrounded. Cylindrical portion 12 continuing to the inner periphery of the contact plate portion 123a
3b. Moreover, the cylindrical portion 1 of the piston 123
The distal end of 23b is set to be located outside the distal end of the cylindrical portion 119a of the first diaphragm retainer 119.

A diaphragm rod 124 is inserted into the center of the first diaphragm retainer 119 from the decompression chamber 94 side, and the inner surface of the cylindrical portion 119a of the first diaphragm retainer 119 has an annular step facing the decompression chamber 94 side. A portion 125 is provided, and a diaphragm rod 124 is engaged with the annular step 125. Further, the screw shaft 1 is attached to the diaphragm rod 124 at a portion protruding from the cylindrical portion 119a.
24a is provided, and a nut 127 is screwed into the screw shaft portion 124a with a washer 126 interposed between the tip of the cylindrical portion 123b and the nut 127 is tightened. While being sandwiched between the diaphragm retainers 119 and 120, a diaphragm rod 124 is fixed to the center of the diaphragm 93,
Further, the piston 123 is connected to the central portion of the diaphragm 93. Moreover, the decompression chamber 94 and the spring chamber 1
16 to seal between the diaphragm rods 124
The annular seal member 128 mounted on the outer periphery of the cylindrical portion 1
Resiliently contacts the inner surface of 19a.

The other end of the valve shaft 107, that is, the end on the diaphragm 93 side, is coaxially fastened to the diaphragm rod 124. The diaphragm rod 124 has a fitting hole 130 with one end opened on the valve shaft 107 side. And a screw hole 131 having a diameter smaller than that of the fitting hole 130 and having the bottom coaxially connected to the other end of the fitting hole 130. On the other hand, the valve shaft 107 has a fitting shaft portion 107a fitted into the fitting hole 130, and a male screw portion 107b coaxially connected to the fitting shaft portion 107a so as to be capable of being screwed into the screw hole 131.
Are provided, and the axial length L of the male screw portion 107b is provided.
₁ is shorter than the axial length L ₂ of the fitting hole 130 (L ₁ <
L ₂ ) is set.

Further, the seal member 128 which resiliently contacts the inner surface of the cylindrical portion 119a is attached to the outer periphery of the diaphragm rod 124 at a portion corresponding to the outside of the screw hole 131 having a smaller diameter than the fitting hole 130. Accordingly, the diameter of the diaphragm rod 124 can be reduced as much as possible.

Incidentally, the diaphragm 93 is connected to the valve shaft 10.
The thickness of the connecting portion, that is, the central portion, and the portion sandwiched between the body 34 and the cover 91, that is, the thickness of the peripheral portion are relatively large, and the portion connecting the central portion and the peripheral portion is compared. The diaphragm 93 is formed in a substantially thin curved surface shape. According to such a diaphragm 93, the pressure resistance of the diaphragm 93 can be improved, and the responsiveness at a low temperature can be improved.

The second diaphragm retainer 120 is integrally provided on the outer peripheral side with a bending restricting portion 120a for restricting the bending of the diaphragm 93 toward the spring chamber 116. The flexure restricting portion 120 a is formed in a curved shape bulging toward the spring chamber 116, and the outer peripheral edge of the flexure restricting portion 120 a is made to approach and face the inner surface of the cover 91. In addition, the thickness of the diaphragm 93 is formed to be larger than the gap at a portion corresponding to the gap between the outer edge of the deflection regulating portion 120a and the inner peripheral surface of the cover 91.

An adjusting screw 132 is screwed into the opening at the outer end of the storage hole 118, that is, the screw hole 118 a so as to be able to advance and retreat, and the adjusting screw 132 and a piston 123 connected to the center of the diaphragm 93. Contact plate part 123
A coil spring 117 is contracted between the coil spring 117 and the coil spring 117. Therefore, the spring load of the coil spring 117 can be adjusted by adjusting the advance / retreat position of the adjustment screw 132. In addition, a concave portion 132a is provided at the inner end of the adjusting screw 132 as a guide portion that receives the entire end of the coil spring 117 on the side opposite to the diaphragm 93.

A lock nut 133 is screwed into a protruding portion of the adjusting screw 132 from the cover 91. The adjusting screw 132 has an opening 134 for opening the spring chamber 116 to the atmosphere.

The piston 123 is connected to the diaphragm 9
On the outer surface of the piston 123, a plurality of, for example, a pair of O-rings 135, 135 that resiliently slidably contact the inner surface of the cover 91 are provided on the outer surface of the piston 123.
The grease 136 is provided between the O-rings 135 and 135 and between the outer surface of the piston 123 and the cover 91 between the O-rings 135 and 135. And piston 1
When the two O-rings 135 and 135 are mounted on one of the two O-rings 135 and 135 from one side in the axial direction,
5 may be damaged by the O-ring groove,
Curved chamfers 123c and 123d are provided on the outer surfaces of both ends in the axial direction of the piston 123, and the O-rings 135 and 135 are attached to the piston 123 from both ends in the axial direction to avoid being damaged by the O-ring groove. Can be easily mounted. In order to prevent the O-rings 135 and 135 from being damaged when the piston 123 with the O-rings 135 and 135 is inserted into the storage hole 118, a tapered chamfer is formed at the inner end opening of the storage hole 118. A portion 118c is provided.

In order to prevent the space between the piston 123 and the diaphragm 93 in the spring chamber 116 from being sealed by the O-rings 135 and 135, the cylindrical portion 123b of the piston 123 extends over the inner and outer surfaces thereof. A communication hole 129 is provided.

The body 34 has a plurality of, for example, four passages 137, 137,.
Are provided at intervals around the mounting hole 97. Further, a plurality of, for example, four projections 138 that can contact the first diaphragm retainer 119 at the center of the diaphragm 93 in order to restrict the deflection of the diaphragm 93 toward the decompression chamber 94 on the raised portion 96 of the body 34.
Are formed so as to form grooves 139 between each other, and each protrusion 13 of the first diaphragm retainer 119 is formed.
When the CNG passes through the valve hole 104 from the valve chamber 103 at the time of contact with the pressure chambers 8, the CNG passes through the grooves 101 formed at the end of the valve seat member 98 on the pressure reducing chamber 94 side and the grooves 139. To the side.

In such a primary pressure reducing valve 37, when high-pressure CNG does not flow into the valve chamber 103, the diaphragm 93 is bent toward the pressure reducing chamber 94 by the spring force of the coil spring 117, and the valve body 106 The valve hole 104 is opened away from the valve seat 105. Thus, the valve chamber 103
When the high-pressure CNG flows into the pressure reducing chamber 94 through the valve hole 104 and the pressure in the pressure reducing chamber 94 increases to the extent that the diaphragm 93 is bent toward the spring chamber 116 against the spring force of the coil spring 117, The valve element 106 is seated on the valve seat 105 to close the valve hole 104, and the opening and closing of the valve hole 104 are repeated, so that the valve chamber 103 has, for example, 250 to 10 kg / cm ^2. CNG that has flowed in at a high pressure is decompressed to, for example, 6 to 7 kg / cm ² and flows from the decompression chamber 94 to the passages 137, 137.

The body 34 has a bottomed mounting hole 97 that is open to the decompression chamber 94 side coaxially with the axis of the valve shaft 107.
And a valve chamber 10 for accommodating the valve element 106.
3 is screwed into the mounting hole 97, and the valve seat 105 facing the valve chamber 103 is the end of the valve seat member 98 on the decompression chamber 94 side. It is formed on the inner surface of the part. Therefore, compared with a configuration in which a valve seat is formed at an inner end of a storage hole provided in a body for storing a valve body and a lid member for sealing an outer end of the storage hole is attached to the body. There is no need to attach a member such as a lid member, and the number of components can be reduced, and the degree of freedom in arranging the primary pressure reducing valve 37 on the body 34 can be increased. Moreover, since the valve seat 105 is formed on the inner surface of the end of the valve seat member 98 on the side of the pressure reducing chamber 94,
The valve body 106 can be arranged as close as possible to the decompression chamber 94 side, which can contribute to downsizing of the body 34.

Further, one end of the valve shaft 107 is supported by the body 34 via a bearing 109, and has a plurality of guide portions 110 slidingly contacting the inner surface of the valve seat member 98 at a plurality of circumferentially spaced locations. Flow passages 111 provided on the outer surface of the valve body 106 and extending along the axial direction of the valve shaft 107 between the guide parts 110 and between the valve body 106 and the valve seat member 98.
Are formed. Therefore, one end of the valve shaft 107 is supported by the body 34 so as to be movable in the axial direction, and the valve shaft 107 is axially moved to the body 34 via the valve body 106 and the valve seat member 98 at a portion where the valve body 106 is fixed. The valve is supported so as to be movable and prevents the valve shaft 107 from falling over even if a lateral load due to the coil spring 117 acts on the valve shaft 107 or the diaphragm 93 is misaligned. The axis of the seat 105 and the axis of the valve body 106 can be accurately matched, and the valve body 106 can be reliably seated on the valve seat 105 over the entire circumference.

By the way, since the valve body 106 is made of a synthetic resin, the valve body 106 is hardened by lowering the environmental temperature, and the sealing ability is reduced. Therefore, the poor pressure regulation due to the inclination of the valve body 106 with respect to the valve seat 105 appears more remarkably as the environmental temperature decreases. However, as shown by the broken line in FIG. In the bearing supported by the valve 34, pressure adjustment failure occurs on the low temperature side due to the inclination of the valve body, and the degree of pressure reduction is reduced. On the other hand, as described above, the valve shaft 107 is connected at one end thereof and the valve body 106. As shown by a solid line in FIG. 11, the valve body 106 is supported by the body 34 and the valve seat member 98.
Can always be properly seated on the valve seat 105 without inclining, so that poor pressure regulation can be prevented and a higher degree of pressure reduction can be obtained.

Further, the sliding resistance caused by each of the guide portions 110 provided on the valve body 106 made of synthetic resin slidingly contacting the inner surface of the valve seat member 98 is generated against the vibration of the coil spring 117. Generation of self-excited vibration can be prevented as much as possible.

The valve seat member 98 is screwed into the mounting hole 97. The end face of the valve seat member 98 on the decompression chamber 94 side has a radius of the valve shaft 107 in a plane orthogonal to the axis of the valve shaft 107. A plurality of protrusions 102 are formed so as to form a plurality of grooves 101 extending in the direction between the protrusions.
The tool is engaged with the groove 101 between the two and the valve seat member 98.
Can be rotated, and attachment of the valve seat member 98 to the body 34 becomes easy.

The valve shaft 107 is located at the center of the diaphragm 93.
Fastened to the fixed diaphragm rod 124
However, the diaphragm rod 124 has a fitting hole 1
30 and a bottomed screw hole 1 coaxially connected to the fitting hole 130.
31 are provided, and the fitting hole 13 is formed in the valve shaft 107.
0, and the screw shaft 131 is screwed into the screw hole 131.
And coaxially connected to the fitting shaft 107a.
Male threaded portion 107b is provided.
Axial length L₁Is the axial length L of the fitting hole 130. _Twothan
It is set short. For this reason, the male screw portion 107b
At the start of screwing into the insertion hole 131, the fitting shaft 107a
A part is already fitted in the fitting hole 130.
You. Therefore, the male screw 107b
Even if chips are generated due to intrusion, the chips are
Enclosed between the shaft 107 and the diaphragm rod 124
This eliminates the need to remove chips, and
Work efficiency can be improved.

The cover 91 is provided with a housing hole 118 having an outer end opened so that the coil spring 117 can be inserted and removed, and is provided coaxially with the axis of the valve hole 104. Since the adjusting screw 132 to be fitted is provided with a concave portion 132a for receiving the entire end of the coil spring 117 on the side opposite to the diaphragm 93, the diaphragm 9
It is not necessary to receive the coil spring 117 with the retainer on the side opposite to the side 3, and the number of parts can be reduced. Moreover, when the peripheral portion of the diaphragm 93 is sandwiched between the body 34 and the cover 91, the coil spring 117 can be taken out of the cover 91, and the diaphragm 93 can be removed.
The cover 91 can be fastened to the body 34 by avoiding the application of an eccentric load on the valve body 105, so that the displacement of the diaphragm 93 can be prevented and the valve seat 105 of the valve body 106 can be prevented.
The seating can be reliably performed, and poor pressure adjustment can be prevented. Further, when the coil spring 117 is compressed by the adjusting screw 132, the concave portion 132a of the adjusting screw 132 performs the guide function of the end of the coil spring 117, and the inclination of the coil spring 117 can be prevented from occurring.

Further, a plurality of, for example, a pair of O-ring members 135 and 135, which resiliently contact the inner surface of the cover 91, are mounted on the outer surface of the piston 123 which reciprocates in the axial direction of the valve shaft 107 in response to the bending of the diaphragm 93. Therefore, sliding resistance against self-excited vibration of the coil spring 117 can be obtained.

The above sliding resistance can be obtained by mounting a single O-ring 135 on the outer surface of the piston 123. However, when the single O-ring 135 is mounted, the sliding resistance shown in FIG. When the pair of O-rings 135 and 135 is mounted, the hysteresis indicated by the broken line is shown, and as shown by the solid line in FIG. 12, the hysteresis is larger, and the self-excitation of the coil spring 117 is performed. A pair of O-rings 13 is used to provide greater sliding resistance against vibration.
5,135.

Further, since the grease 136 is filled between the two O-rings 135 and 135, the outflow of the grease 136 is avoided as much as possible even during long-term operation, so that each of the O-rings 135 and 135 can be prevented.
135 can be suppressed, and the oil components contained in the air that has entered the spring chamber 116 from the outside can be reduced by each O.
Even if it adheres to the rings 135 and 135, the sliding resistance is set in consideration of the grease 136 in the initial state, so that the sliding resistance does not decrease. Further, since the necessary sliding resistance is obtained by the pair of O-rings 135 and 135, even if the compression ratio is set in consideration of the permanent strain of each of the O-rings 135 and 135 in order to obtain an appropriate sliding resistance, each of the O-rings 135 and 135 is set. The diameter of the O-rings 135 and 135 is not increased, and the degree of freedom in arrangement of the O-rings 135 and 135 can be increased.

The piston 123 can be moved in a limited range in the axial direction of the valve shaft 107 so that the cover 91 can move.
The piston 123 is slidably fitted to the piston 93 and is connected to the central portion of the diaphragm 93. Therefore, the piston 123 may be provided with a centering function to make the bending direction of the diaphragm 93 coincide with the axis of the valve hole 104. it can. That is, the diaphragm 93 has a coil spring 11 having a relatively large spring force.
7, a spring force in the direction of reducing the volume of the decompression chamber 94 is acting. However, when the coil spring 117 falls down, the bending direction of the diaphragm 93, that is, the valve shaft 107
May also fall, and the seating of the valve body 106 on the valve seat 105 may be incomplete, resulting in poor pressure regulation. However, since the piston 123 is slidably fitted to the cover 91, it is possible to prevent the axial line of the valve shaft 107 from falling down and to prevent poor pressure regulation.

Further, the piston 123 is provided with a communication hole 129 for communicating the inside and the outside thereof, so that the back pressure of the diaphragm 93 is prevented from undesirably increasing or decreasing according to the reciprocating movement of the diaphragm 93 and the piston 123. Is done.

Further, the diaphragm 9 is located on the spring chamber 116 side.
The third diaphragm retainer 120, which is in contact with and fixed to the central portion of the third, has a flexure restricting portion 120a formed in a curved shape bulging toward the spring chamber 116 with the outer peripheral edge approaching and facing the inner surface of the cover 91. ing. Therefore, the decompression chamber 9
Even when a pressure higher than the specified pressure acts on the diaphragm 4, the diaphragm 93 can be smoothly curved from the second diaphragm retainer 120 to the inner surface of the cover 91 as shown by a chain line in FIG. Of the diaphragm 93 is prevented from bending toward the spring chamber 116 at the outer edge of the diaphragm 93, and the life of the diaphragm 93 is prevented from being shortened by the bending, so that the durability of the diaphragm 93 can be improved.

[Secondary pressure reducing valve 38] Referring to FIG. 13 together, the valve housing 140 of the secondary pressure reducing valve 38 includes an upper portion of the body 34 and an upper surface of a flange portion 77 provided on the upper portion of the body 34. The cover 141 is fastened by a plurality of bolts 142. A peripheral portion of the diaphragm 143 is sandwiched between the upper surface of the body 34 and the cover 141.

On the upper surface of the body 34, the diaphragm 14
A concave portion 145 for forming a decompression chamber 144 is provided between the bottom portion 3 and the body 34. The body 34 has a bottomed bottom having an upper end opened toward the decompression chamber 144 at the center of the closed end of the concave portion 145 and a lower end closed. A mounting hole 147 is provided to extend vertically. Further, a protruding portion 146 protruding toward the decompression chamber 144 is provided at the inner end closing portion of the mounting hole 147.

A female screw 150 is formed in the inner surface of the end of the mounting hole 147 on the side of the decompression chamber 144, and a cylindrical valve seat member 148 is screwed into the female screw 150, and
An annular seal member 149 that resiliently contacts the inner surface of the mounting hole 147 on the outer surface of the female screw 150 on the outer surface of the female screw 150 is mounted.

Further, a plurality of, for example, four grooves 151 extending in the radial direction of the valve seat member 148 in a plane perpendicular to the axis of the mounting hole 147 are formed between the end surfaces of the valve seat member 148 on the pressure reducing chamber 144 side. A plurality of, for example, four projections 1
52 are protruded, and the grooves 151 are arranged in a cross shape. When the valve seat member 148 is screwed into the female screw 150, a tool (not shown) can be engaged with the grooves 151 arranged in a cross shape to rotate the valve seat member 148. The member 148 can be easily attached to the body 34.

A valve chamber 153 is formed between the valve seat member 148 and the lower end closing portion of the mounting hole 147.
Has a plurality of passages 1 for guiding CNG from the primary pressure reducing valve 37.
Are communicated. Also, the valve seat member 148
An inward flange 148a extending radially inward at the end of the decompression chamber 144 is integrally provided.
A valve hole 154 communicating with the decompression chamber 144 is formed on the inner periphery of the valve chamber 148, and an annular valve seat 155 facing the valve chamber 153 with the valve hole 154 opened at the center at the inner surface of the inward flange 148a.
Are formed so as to protrude toward the valve chamber 153.

The raised portion 146 is provided with a bottomed sliding hole 157 which is open to the valve hole 154 side and is coaxial with the valve hole 154. The valve body 156 is slidably fitted in the sliding hole 157. Are combined. Moreover, an annular rubber seal 158 that can be seated on the valve seat 155 is fixed to the valve body 156.

The valve body 156 is provided coaxially with a screw hole 159 extending between both ends in the axial direction. One end of a valve shaft 160 coaxial with the valve hole 154 is screwed into the screw hole 159. That is, the valve body 156 is fixed to one end of the valve shaft 160.

A back pressure chamber 161 is formed between the valve body 156 and the closed end of the sliding hole 157, and the outer surface of the valve body 156 is elastically slidably in contact with the inner surface of the sliding hole 157. A plurality of, for example, a pair of O-rings 162, 162 are mounted at intervals in the axial direction of the valve body 156,
Grease (not shown) is filled between the outer surface of the valve body 156 and the inner surface of the sliding hole 157 between the second and second 162.

A spring chamber 166 is formed between the cover 141 and the diaphragm 143. The spring chamber 166 accommodates a coil spring 167 for urging the diaphragm 143 toward the decompression chamber 144.

At the center of the diaphragm 143, an insertion hole 168 is provided, and an annular seal portion 143a surrounding the insertion hole 168 is provided. The surface of the diaphragm 143 facing the decompression chamber 144 has the above-mentioned structure. A first diaphragm retainer 169 in the shape of a ring plate surrounding the seal portion 143a is abutted, and a second diaphragm retainer 170 having an insertion hole 171 at the center is formed on the surface facing the spring chamber 166 at the center of the diaphragm 143. The diaphragm 143 is brought into contact with the one diaphragm 169 so as to sandwich the diaphragm 143 therebetween.

On the other hand, a piston 173 formed in a cylindrical shape is fitted to the cover 141 in the spring chamber 166 so as to be able to slide in the axial direction within a limited range. Is provided with a ring-shaped contact plate portion 173a having an insertion hole 172 corresponding to the insertion hole 171 at the center thereof and in contact with the second diaphragm retainer 170.

A valve shaft 160 having a valve body 156 fixed at one end.
Extends coaxially through the valve hole 154 toward the spring chamber 166, and engages with the inner peripheral edge of the first diaphragm retainer 169 and the annular step portion 174 and the seal portion 143.
An annular step 175 is provided on the valve shaft 160 so as to pinch a with the second diaphragm retainer 170. Insertion hole 16
A screw shaft 160a is provided at the other end of the valve shaft 160 that protrudes into the spring chamber 166 through the holes 8,171,172.
Washer 17 between second diaphragm retainer 170
6, a nut 177 is screwed into the screw shaft 160a. By tightening this nut 177,
The central portion of the diaphragm 143 is sandwiched between the two diaphragm retainers 169 and 170, and the valve shaft 160 is connected to the central portion of the diaphragm 143. In addition, the valve shaft 160 is provided with a communication path 163 that allows the pressure reduction chamber 144 to communicate with the back pressure chamber 161.

The second diaphragm retainer 170 is integrally provided on the outer peripheral side with a deflection restricting portion 170a for restricting the deflection of the diaphragm 143 toward the spring chamber 166. The flexure restricting portion 170 a is formed in a curved shape bulging toward the spring chamber 166, and the outer peripheral edge of the flexure restricting portion 170 a is made to approach and face the inner surface of the cover 141.

By the way, at the outer end closed portion of the cover 141, a support cylinder 178 having both ends opened is integrally provided.
79 is engraved. The adjusting screw 180 is inserted into the support cylinder 178.
A male screw portion 180a provided on the inner end side in the axial direction is screwed into the female screw 179 and protrudes into the spring chamber 166. The adjusting screw 180 is also provided on the outer side in the axial direction.
0b, and the externally threaded portion 180b projects outside the cover 141. Further, an annular seal member 181 is mounted on the outer surface of the adjusting screw 180 at the axially intermediate portion, and the seal member 181 resiliently contacts the inner surface of the support cylinder 178.

A retainer 182 abuts and is supported on the inner end of the adjusting screw 180 in the spring chamber 166. The abutment plate 173 a of the piston 173 connected to the retainer 182 and the center of the diaphragm 143. And a coil spring 167 is contracted. Therefore adjustment screw 1
By adjusting the advance / retreat position of the coil spring 16,
7, the spring load can be adjusted.

A nut 184 is screwed into the protrusion of the adjusting screw 180 from the cover 141, that is, the male screw portion 180b, with a washer 183 interposed between the adjusting screw 180 and the cover 141. By loosening the nut 184,
The advance / retreat position of the adjusting screw 180 can be adjusted.

Referring to FIGS. 14 and 15, the outer end of the adjusting screw 180 and the nut 184 are covered with a cap 185 made of synthetic resin. Moreover, the nut 1
Reference numeral 84 denotes an outer peripheral surface composed of four flat surfaces 184a... Arranged at equal intervals in the circumferential direction parallel to the axis of the adjusting screw 180, and four curved surfaces 184b connecting the flat surfaces 184a. Is configured to have
An annular engaging projection 18 projecting from the inner surface of the cap 185
6 are provided on each of the curved surfaces 184b.

By the way, the piston 173 slides integrally with the diaphragm 143.
O-rings 188, 188 which are resiliently slidably in contact with the inner surface of the cover 141 are attached to a plurality of, for example, two, locations on the outer surface of the outer surface 3 spaced apart in the axial direction.
8,188 between the outer surface of the piston 173 and the cover 14
Grease (not shown) is filled between the inner surfaces of the first member 1. In addition, the piston 173 has two O-rings 18 on one side in the axial direction.
When the 8, 188 is mounted, one of the O-rings 188, 188 may be damaged by the O-ring groove, but curved outer chamfers 173b, 173c are provided on the outer surfaces of both ends of the piston 173 in the axial direction. The O-ring 13 is provided so as not to be damaged by the O-ring groove.
5, 135 can be easily attached to the piston 173 from both ends in the axial direction. O-ring 18
The cover 141 covers the piston 173 with the 8,188 attached.
In order to prevent the O-rings 188 and 188 from being damaged when inserted into the
A tapered chamfered portion 141a is provided at the inner end of the portion where the 73 is fitted.

In order to prevent the space between the piston 173 and the diaphragm 143 in the spring chamber 166 from being sealed by the O-rings 188, 188,
The piston 173 has a communication hole 129 extending between the inner and outer surfaces thereof.
Is provided.

The body 34 is provided with a passage 189 communicating with the decompression chamber 144, and the passage 189 is connected to the conduit 30 connected to the injector 29 of the engine E. Further, a connection pipe 190 is connected to the cover 141, and the intake negative pressure of the engine E is introduced into the spring chamber 166 via the connection pipe 190 and a pipe (not shown) connected to the connection pipe. Is done.

In such a secondary pressure reducing valve 38, when CNG does not flow into the valve chamber 153, the diaphragm 143 is moved by the spring force of the coil spring 167.
The valve body 156 is separated from the valve seat 155 to open the valve hole 154. The CNG that has flowed into the valve chamber 153 flows into the decompression chamber 144 through the valve hole 154, and the pressure difference between the decompression chamber 144 and the spring chamber 166 causes the diaphragm 143 to spring against the spring force of the coil spring 167. When the valve body 156 increases to the extent that it is bent toward the chamber 166,
Is seated on the valve seat 155, and the valve hole 154 is closed. By repeatedly opening and closing the valve hole 154, the valve chamber 153 has, for example, 6 to 7 kg / cm.
² is reduced to, for example, ² to 3 kg / cm ^2, and is passed from the decompression chamber 144 to the passage 189 and the conduit 30.
Through the injector 29.

The body 34 has a bottomed mounting hole 1 which is coaxial with the axis of the valve shaft 160 and opens toward the decompression chamber 144.
A cylindrical valve seat member 148 that forms a valve chamber 153 for accommodating the valve element 156 with the closed end of the mounting hole 147 is screwed into the mounting hole 147 and faces the valve chamber 153. The valve seat 155 is the pressure reducing chamber 14 of the valve seat member 148.
It is formed on the inner surface of the end on the four side. Therefore, compared with a configuration in which a valve seat is formed at an inner end of a storage hole provided in a body for storing a valve body and a lid member for sealing an outer end of the storage hole is attached to the body.
There is no need to attach a member such as a lid member, and the number of components can be reduced, and the degree of freedom in arranging the secondary pressure reducing valve 38 on the body 34 can be increased. In addition, since the valve seat 155 is formed on the inner surface of the end of the valve seat member 148 on the side of the decompression chamber 144, the valve body 156 can be arranged as close as possible to the decompression chamber 144, and the body 34 can be downsized. Can also contribute.

The valve seat member 148 is screwed into the mounting hole 147. The valve shaft 160 is attached to the end surface of the valve seat member 148 on the side of the decompression chamber 144 in a plane perpendicular to the axis of the valve shaft 160.
Are formed so as to protrude from each other to form a plurality of grooves 151 extending in the radial direction.
The tool is engaged with the groove 151 between the 52.
48 can be rotated, and the valve seat member 148 can be rotated.
Can be easily attached to the body 34. Moreover, the deflection of the diaphragm 143 toward the decompression chamber 144 is caused by the protrusions 152.
Is regulated by contact with the projections 152. However, even when the diaphragm 143 is in contact with each of the projections 152,.
The communication between the valve hole 154 and the decompression chamber 144 can be made through the respective grooves 151.

Further, a plurality of, for example, a pair of O-rings 162 and 162 resiliently slidingly contacting the body 34 are mounted on the outer surface of the valve body 156 which reciprocates in the axial direction of the valve shaft 160 in response to the bending of the diaphragm 143, and the diaphragm is mounted. Since a plurality of, for example, a pair of O-rings 188, 188 that resiliently slide on the inner surface of the cover 141 are mounted on the outer surface of the piston 173 that reciprocates in the axial direction of the valve shaft 160 in accordance with the bending of the 143, the coil A high sliding resistance against self-excited vibration of the spring 167 can be obtained.

Further, since grease is filled between the O-rings 162 and 162 and between the O-rings 188 and 188, the outflow of grease can be avoided as much as possible even by long-term operation, so that the O-rings 162 and 162; The oil component contained in CNG adheres to the O-rings 162 and 162, and the oil component contained in the intake air introduced into the spring chamber 166 becomes the O-ring 1
Even if it adheres to 88 and 188, the sliding resistance is set in consideration of the grease in the initial state, so that the sliding resistance does not decrease. Further, a pair of O-rings 16
2, 162; 188, 188, the necessary sliding resistance is obtained.
Even if the compression ratio is set in consideration of the permanent distortion of the rings 162 and 188, the diameters of the O rings 162 and 188 do not increase, and the O rings 162 and 162;
Can be increased in arrangement flexibility.

The piston 173 can be moved within a limited range in the axial direction of the valve shaft 160 so that the cover
The piston 173 has a centering function of making the bending direction of the diaphragm 143 coincide with the axis of the valve hole 154 because the piston 173 is fitted to the center of the diaphragm 143 in a slidable manner. Can be. That is,
The spring 167 having a relatively large spring force acts on the diaphragm 143 in the direction of reducing the volume of the decompression chamber 144. However, when the coil spring 167 falls down, the diaphragm 143 bends. The direction, that is, the axis of the valve shaft 160 also falls down, and the seating of the valve body 156 on the valve seat 155 may be incomplete, resulting in poor pressure regulation. However, piston 173 covers 14
By being slidably fitted to 1, it is possible to prevent the axial line of the valve shaft 160 from falling down and to prevent poor pressure regulation.

Further, the piston 173 is provided with a communication hole 192 for connecting the inside and the outside thereof, so that the back pressure of the diaphragm 143 is prevented from undesirably increasing or decreasing according to the reciprocating movement of the diaphragm 143 and the piston 173. Is done.

Further, the diaphragm 1 is located on the spring chamber 166 side.
The second diaphragm retainer 170, which abuts and is fixed to the central portion of the cover 43, has a flexure restricting portion 170a provided on the outer peripheral portion.
It is formed in a curved shape bulging to the 66 side. Therefore, even when a pressure higher than the specified pressure acts on the decompression chamber 144, the diaphragm 14 is moved from the second diaphragm retainer 170 to the inner surface of the cover 141 as shown by a chain line in FIG.
3 can be smoothly curved, the diaphragm 143 is prevented from bending toward the spring chamber 166 at the outer edge of the second diaphragm retainer 170, and the life of the diaphragm 143 is prevented from being shortened due to the bending. 143 can be improved in durability.

A nut 184 screwed to the outer end of the adjustment screw 180 to fix the advance / retreat position of the adjustment screw 180
Are arranged parallel to the axis of the adjusting screw 180 at equal intervals in the circumferential direction and four curved surfaces 184b connecting between the flat surfaces 184a are formed. Each of the curved surfaces 184b has an engagement groove 187 for engaging an annular engagement protrusion 186 projecting from the inner surface of the cap 185. That is, since the cap 185 is mounted on the nut 184, the size of the cap 185 can be reduced, and since the nut 184 has an outer peripheral surface with four chamfers, the number of processing steps for the nut 184 can be reduced. In addition, since the engagement grooves 187 are provided on each of the curved surfaces 184b, the engagement grooves 187 are formed to be relatively long, and the amount of engagement of the engagement protrusions 186 of the cap 185 with the engagement grooves 187 is reduced. It can be relatively large so that the cap 185 does not come off easily.

[Relief valve 39]; paying particular attention to FIG. 4, the relief valve 39 is connected to one of a plurality of passages 137, 137,... Connecting the primary pressure reducing valve 37 and the secondary pressure reducing valve 38. A rubber seal 197 capable of closing the valve hole 195 is provided in a valve housing 196 having a valve hole 195 at the front end, which is connected to the passage 137, and fixed to the body 34. And a spring 199 for urging the valve 198 in a direction to close the valve hole 195 with the rubber seal 197 are housed.
Is formed such that CNG from the passage 137 can be opened to the outside when the valve hole 195 is opened.

According to the relief valve 39, the spring 199
When the pressure in the passage 137 rises above the valve opening pressure, for example, 16.5 kg / cm ² , the valve is opened to release CNG to the atmosphere.

[Thermostat 40] With particular attention to FIG. 5, the body 34 has a filter 35, an electromagnetic shut-off valve 36, a primary pressure reducing valve 37, a secondary pressure reducing valve 38, and a relief valve disposed on the body 34. A hot water passage 33 is provided so as not to hinder the arrangement of the hot water passage 39.
A connection pipe 201 communicating with the inlet of the third water heater 3 is attached to the body 34, and the thermostat 40 is attached to the body 34 on the outlet side of the hot water passage 33.

The thermostat 40 has a conventionally well-known configuration. The thermostat 40 expands a valve body 204 capable of opening and closing a valve hole 203 provided at an outer end of a housing 202 fixed to the body 34 by the temperature of the wax 205. It is configured to operate according to the degree. And the water temperature
For example, when the temperature exceeds 80 degrees, the wax 205 drives the valve body 204 to close the valve hole 203 so that the temperature of the body 34 is adjusted so as not to rise above 80 degrees.

By the way, the filter 35,
In a regulator R including an electromagnetic cutoff valve 36, a primary pressure reducing valve 37, a secondary pressure reducing valve 38, a relief valve 39, and a thermostat 40, a primary pressure reducing valve 37 and a secondary pressure reducing valve 38 are provided below and above a body 34. Since the valve bodies 96 and 156 are coaxially arranged and mounted, and the filter 35, the electromagnetic shut-off valve 36, the relief valve 39 and the thermostat 40 are disposed on the side of the body 34, the regulator R is It can be made compact. Moreover, the electromagnetic shut-off valve 36 and the relief valve 3
Numeral 9 is arranged in a space formed below the flange portion 77 provided on the body 34 to fasten the cover 141 of the secondary pressure reducing valve 38, and can further contribute to downsizing of the regulator R.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, a protrusion may be provided on the adjusting screw 132 as a guide for guiding the end on the opposite side of the coil spring 117.

[0114]

As described above, according to the first aspect of the present invention, the end of the coil spring opposite to the diaphragm is directly received by the concave portion provided in the adjusting screw, thereby eliminating the need for a retainer. The number of parts can be reduced. Moreover, the coil spring can be taken out of the cover when the peripheral portion of the diaphragm is sandwiched between the body and the cover, and the cover can be fastened to the body by avoiding the application of an eccentric load to the diaphragm. , The valve body can be securely seated on the valve seat, and poor pressure regulation can be prevented. Since the end opposite to the diaphragm is guided by the guide portion, it is possible to prevent the coil spring from tilting.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a fuel supply device for a vehicle.

FIG. 2 is a side view of the regulator.

FIG. 3 is a plan view of the regulator.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is an enlarged vertical sectional view of an electromagnetic shut-off valve.

FIG. 7 is a diagram showing a suction characteristic of an electromagnetic shut-off valve.

FIG. 8 is an enlarged vertical sectional view of a primary pressure reducing valve.

FIG. 9 is an enlarged sectional view taken along line 9-9 of FIG.

FIG. 10 is an enlarged view of a main part of FIG. 8;

FIG. 11 is a diagram showing a pressure reducing characteristic of the primary pressure reducing valve according to the environmental temperature.

FIG. 12 is a diagram illustrating hysteresis characteristics according to the number of O-rings mounted on a piston.

FIG. 13 is an enlarged vertical sectional view of a secondary pressure reducing valve.

FIG. 14 is a sectional view taken along line 14-14 of FIG.

FIG. 15 is a vertical sectional side view showing only a cap taken along a line 15-15 in FIG. 14;

[Explanation of symbols]

 34 ... body 37 ... pressure reducing valve 91 ... cover 93 ... diaphragm 94 ... pressure reducing chamber 104 ... valve hole 105 ... valve seat 106 ... valve element 116 ... spring Chamber 117: coil spring 118: storage hole 132: adjusting screw 132a: concave portion as a guide portion

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[Procedure amendment]

[Submission date] March 8, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction contents]

Referring also to FIG. 10, the diaphragm 9
A first diaphragm retainer 1 integrally having a cylindrical portion 119a that penetrates the center of the diaphragm 93 and protrudes toward the spring chamber 116 on a surface facing the decompression chamber 94 at the center of the third.
19 abuts on the spring chamber 1 at the center of the diaphragm 93.
On the surface facing the 16 side, the inner periphery is engaged with an annular step portion 121 provided on the outer surface of the cylindrical portion 119a, and the diaphragm 9 is
The second diaphragm retainer 120 that sandwiches the central portion of the third between the first diaphragm retainer 119 and the first diaphragm retainer 119 is in contact with the first diaphragm retainer 119.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0072

[Correction method] Change

[Correction contents]

[0072] Further the outer surface of the piston 123 which reciprocates in the axial direction of the valve shaft 107 in response to deflection of the diaphragm 93, O-ring 1 35,135 inner surface a plurality of, for example, a pair elastically sliding contact with the cover 91 Since it is installed,
Sliding resistance against self-excited vibration of the coil spring 117 can be obtained.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0087

[Correction method] Change

[Correction contents]

At the center of the diaphragm 143, an insertion hole 168 is provided and an annular seal portion 143a surrounding the insertion hole 168 is provided. The surface of the diaphragm 143 facing the decompression chamber 144 has the above-mentioned structure. A first diaphragm retainer 169 in the shape of a ring plate surrounding the seal portion 143a is abutted, and a second diaphragm retainer 170 having an insertion hole 171 at the center is formed on the surface facing the spring chamber 166 at the center of the diaphragm 143. 1 diaphragm
The diaphragm 143 is in contact with the retainer 169 so as to sandwich the diaphragm 143 therebetween.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0095

[Correction method] Change

[Correction contents]

By the way, the piston 173 slides integrally with the diaphragm 143.
O-rings 188, 188 which are resiliently slidably in contact with the inner surface of the cover 141 are attached to a plurality of, for example, two, locations on the outer surface of the outer surface 3 spaced apart in the axial direction.
8,188 between the outer surface of the piston 173 and the cover 14
Grease (not shown) is filled between the inner surfaces of the first member 1. In addition, the piston 173 has two O-rings 18 on one side in the axial direction.
8 and 188, one of the two O-rings 188 and 188 may be damaged by the O-ring groove, but curved outer chamfers 173b and 173c are provided on the outer surfaces of both ends of the piston 173 in the axial direction. The O-ring 18 is provided to avoid being damaged by the O-ring groove.
8, 1 88 can be a respectively easily mounted from the axial end side to the piston 173. O-ring 18
The cover 141 covers the piston 173 with the 8,188 attached.
In order to prevent the O-rings 188 and 188 from being damaged when inserted into the
A tapered chamfered portion 141a is provided at the inner end of the portion where the 73 is fitted.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0096

[Correction method] Change

[Correction contents]

In order to prevent the space between the piston 173 and the diaphragm 143 in the spring chamber 166 from being sealed by the O-rings 188, 188,
The piston 173, the communication hole 1 92 extending between its inner and outer surfaces
Is provided.

[Procedure amendment 7]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 8]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

[Procedure amendment 9]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 13

Claims (2)

[Claims] A diaphragm (9) is provided between a body (34) and a cover (91) fastened to the body (34).
The valve seat (10) in which the peripheral portion of (3) is sandwiched, and a valve hole (104) communicating with the pressure reducing chamber (94) formed between the diaphragm (93) and the body (34) is opened in the center.
A valve body (106) that can be seated on 5) is connected to the center of the diaphragm (93), and a spring chamber (11) formed between the cover (91) and the diaphragm (34).
6) houses a coil spring (117) for urging the diaphragm (93) in a direction to reduce the volume of the decompression chamber (94), and the coil spring (117) is moved in accordance with the axially advanced / retracted position. In a gas pressure reducing valve in which an adjusting screw (132) for adjusting a spring load is screwed to the cover (91) so as to be able to advance and retreat, the coil spring (117) can be inserted into and removed from the cover (91). A storage hole (118) having an outer end opened is provided coaxially with the axis of the valve hole (104), and an adjusting screw (132) screwed into the outer end opening of the storage hole (118) is provided. A pressure reducing valve for gas, wherein an end of the coil spring (117) opposite to the diaphragm (93) is received. 2. The adjusting screw (132) is provided with a guide portion (132a) for guiding an end of the coil spring (117) on the side opposite to the diaphragm (93). The pressure reducing valve for gas as described in the above.