JPH0710466U - Pressure control valve - Google Patents

Abstract

(57) [Summary] [Purpose] To increase the fuel resistance of the diaphragm while suppressing cost increase. [Structure] A housing 11 forming a control valve chamber 16, and
The outer peripheral portion of the diaphragm 12 is sandwiched between the case 21 and the case 21 forming the negative pressure chamber 20 and is stretched. The diaphragm 12 is formed by stacking an upper diaphragm member 12a made of NBR and a lower diaphragm member 12b made of fluororubber. The lower diaphragm member 12b is formed to have a smaller diameter than the upper diaphragm member 12a, and the annular rib 12c is bulged on the upper diaphragm member 12a.
Is fitted in an annular groove 11c formed in the housing 11. [Effect] Since the lower diaphragm that comes into contact with fuel is made of fluororubber, it has high fuel resistance. Since only the lower diaphragm member is formed of fluororubber and the annular rib is formed on the upper diaphragm, cost increase can be suppressed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pressure control valve, and more particularly to improvement of a diaphragm used for the pressure control valve and an assembling structure thereof. For example, the present invention is effective for controlling the fuel supply amount according to the fuel pressure. Regarding

[0002]

[Prior art]

 Generally, in a vehicle such as an automobile, a fuel pressure control valve having a rubber diaphragm is used in a fuel supply passage for supplying fuel in a fuel tank to an engine.

As a conventional fuel pressure control valve of this type, there is one described in Japanese Utility Model Laid-Open No. 4-32265. That is, in this pressure control valve, a housing that forms a control valve chamber together with the diaphragm has a fuel introduction passage and a fuel discharge passage that communicate with the control valve chamber, and forms a negative pressure chamber together with the diaphragm. Is fixed to the housing. The outer peripheral portion of the diaphragm is sandwiched between the case and the housing and fastened together. On the inlet side of the fuel outlet of the housing, there is formed a spherical valve body mounting part with a spherical valve body that works in conjunction with the diaphragm, and the spherical valve body is attached to the diaphragm side at the position adjacent to the spherical valve body mounting part. The spring mounting portion is formed with a spring mounting portion, and the pipe mounting portion with the pipe press-fitted is formed on the outlet side of the fluid outlet path.

Further, in this fuel pressure control valve, the diaphragm is made of a rubber member having an upper and lower two-layer structure. In this case, the upper and lower two diaphragm members are each formed in a disk shape, and the diaphragm rib on the control valve chamber side is formed with an annular rib that is bulged and fitted into the annular groove of the housing, so that the position is improved. A rule and a seal are secured.

[0005]

[Problems to be solved by the device]

 However, in the fuel pressure control valve as described above, even if the diaphragm is composed of a two-layer rubber member, when alcohol-containing gasoline is used as fuel, the diaphragm member on the control valve chamber side is There is a risk of deterioration due to contact with alcohol.

A first object of the present invention is to provide a pressure control valve capable of preventing deterioration of a lower diaphragm member due to fuel.

In order to achieve this first object, the use of fluororubber having extremely high fuel resistance and chemical resistance as the lower diaphragm member on the side of the control valve chamber that comes into contact with fuel is proposed. The inventor thought. When fluorine rubber is used for the lower diaphragm member, deterioration due to fuel can be prevented because the fluorine rubber itself has extremely high fuel resistance and chemical resistance.

However, when fluororubber is used for the lower diaphragm member and the annular rib is bulged and formed on the lower diaphragm member, the fluororubber is extremely expensive. The present inventor has revealed that there is a problem that the cost is increased.

A second object of the present invention is to provide a pressure control valve capable of suppressing an increase in cost even if fluorine rubber is used for the lower diaphragm member on the control valve chamber side. .

[0010]

[Means for Solving the Problems]

 In the pressure control valve according to the present invention, a housing that forms a fluid pressure chamber together with the diaphragm is fixed to a housing that forms a control valve chamber together with the diaphragm, and the periphery of the diaphragm is sandwiched between the case and the housing. In this pressure control valve, the diaphragm is made of a rubber member with a two-layer structure, and the annular rib bulged on the diaphragm is inserted into the annular groove provided in the diaphragm mounting part of the housing. Of the two-layer structure diaphragm, the lower diaphragm member on the control valve chamber side is formed of fluororubber, and the lower diaphragm member is formed to have a smaller diameter than the upper diaphragm member on the fluid pressure chamber side. There is an annular rib in the area surrounding the outer peripheral side of the lower diaphragm member of the upper diaphragm member. It is output form, characterized in that is.

[0011]

[Action]

 According to the above-mentioned means, since the lower diaphragm member, which is in contact with the fluid in the control valve chamber, is formed of fluororubber among the diaphragm composed of the two-layer rubber member, the fuel resistance of the diaphragm is reduced. It is possible to improve performance and chemical resistance. Further, since only the lower diaphragm member is made of fluororubber, the cost increase can be suppressed as compared with the case where the entire diaphragm is made of fluororubber.

On the other hand, since the annular rib is formed to bulge on the upper diaphragm member, the lower diaphragm member using expensive fluororubber may be formed in a simple disc shape. As a result, it is possible to avoid a decrease in yield when the annular rib is formed on the lower diaphragm member made of expensive fluororubber, and it is possible to further suppress the cost increase.

[0013]

【Example】

 FIG. 1 shows a fuel pressure control valve according to an embodiment of the present invention. (A) is a side sectional view and (b) is an enlarged partial sectional view.

In this embodiment, the pressure control valve according to the present invention is configured as a fuel pressure control valve 10 provided in a fuel supply system of an automobile, and the fuel pressure control valve 10 is a die-cast housing. 11, a diaphragm 12, and a spherical valve body 13. The housing 11 is provided with a fuel introduction passage 14 and a fuel discharge passage 15, and a control valve chamber 16 is formed between the passages 14 and 15. A pipe pressure inlet 15a is formed on the outlet side of the fuel outlet passage 15 and a spherical valve body mounting portion 15b is formed on the inlet side of the fuel outlet passage 15 between the pipe pressure inlet 15a and the spherical valve body mounting portion 15b. The valve spring mounting portions 15c are formed adjacent to each other. The inner diameter of the valve spring mounting portion 15c is smaller than the inner diameters of the pipe pressure inlet 15a and the spherical valve body mounting portion 15b.

A return pipe 17 connected to the fuel tank is press-fitted into the pipe pressure inlet 15a, a valve spring 18 made of a coil spring is fitted into the valve spring mounting portion 15c, and a spherical valve body mounting portion 15b. A spherical valve element 13 that is linked to the diaphragm 12 is inserted in the valve. The spherical valve body 13 is configured by using a hard sphere, and is seated on and off a valve seat surface formed on the bottom of the spherical valve body mounting portion 15b.

The diaphragm 12 constitutes a part of the wall surface of the control valve chamber 16 and is fastened to a flange portion 19 of the housing 11 together with a case 21 constituting a negative pressure chamber 20. A holding hole 22 is opened in the center of the diaphragm 12, and a holder 23 is mounted in the holding hole 22. One end of the receiver 23 is in contact with the spherical valve body 13, and the other end of the receiver 23 is fixed to a support plate 24 in contact with the diaphragm 12. A return spring 25, which is a coil spring, is interposed between the support plate 24 and the end wall of the case 21 in a stored state, and the receiving member 23 is moved toward the spherical valve body 13 by the urging force of the return spring 25. The spherical valve element 13 is constantly urged by the urging force of the return spring 25 to always close the inlet side of the fuel outlet passage 15.

When fuel is supplied into the control valve chamber 16 and the pressure inside the control valve chamber 16 increases, the diaphragm 12 moves toward the negative pressure chamber 20 side against the urging force of the return spring 25. It is supposed to do. At this time, the spherical valve body 13 is moved toward the diaphragm 12 by the urging force of the valve spring 18 and moves away from the valve seat surface, so that the inlet side of the fuel discharge passage 15 is opened. That is, the fuel introduction path 14 and the fuel derivation path 15 are in a valve open state in which they are communicated with each other through the control valve chamber 16.

In this embodiment, the diaphragm 12 has a two-layer structure of upper and lower layers, and the upper diaphragm member 12a on the negative pressure chamber 20 side and the lower diaphragm member 12b on the control valve chamber 16 side are overlapped with each other. Is formed. The upper diaphragm member 12a is made of acrylonitrile-butadiene rubber (NBR) and has a circular ring shape, and the lower diaphragm member 12b is made of fluororubber and has a circular ring shape. Furthermore, the outer diameter of the lower diaphragm member 12b is smaller than the outer diameter of the upper diaphragm member 12a.

In addition, a circular ring-shaped annular rib 12c is formed in a concentric circle so as to surround the outer peripheral side of the lower diaphragm member 12b on the end surface of the lower diaphragm member 12b on the upper diaphragm member 12a side. The annular rib 12c is formed by vulcanization molding, and its inner diameter is set to be slightly smaller than the outer diameter of the lower diaphragm 12b. The annular rib 12c is fitted in the annular groove 11c that is recessed in the upper surface of the flange portion 19 of the housing 11. Further, a thick portion 12d is formed in a portion outside the annular rib 12c of the upper diaphragm member 12a, and has a circular ring shape with a thickness obtained by adding the thickness of the lower diaphragm member 12b.

Next, the operation of the two-layer structure diaphragm will be described. When the lower diaphragm member 12b is fitted into and abuts against the end face of the upper diaphragm member 12a on the annular rib 12c side, the lower diaphragm member 12b is concentrically overlapped with the upper diaphragm member 12a. become.

In this state, the annular rib 12c is fitted in the annular groove 11c so that the lower surfaces of the thick portions 12d of the lower diaphragm member 12b and the upper diaphragm member 12a abut on the upper surface of the flange portion 19. Thus, the diaphragm 12, which is an assembly of the upper diaphragm member 12a and the lower diaphragm member 12b, is set on the housing 11. By fitting the annular rib 12c into the annular groove 11c, the diaphragm 12 is properly set concentrically in the housing 11. At this time, since the lower diaphragm member 12b and the upper diaphragm member 12a are concentrically overlapped with each other, the lower diaphragm member 12b is also properly set in the housing 11.

After that, the case 12 is put on the diaphragm 12, and the outer peripheral side of the case 21 is wound and crimped on the flange portion 19, so that the diaphragm 12 is fastened to the housing 11 together with the case 21. In this fastening state, the annular rib 12c of the upper diaphragm member 12a is inserted into the annular groove 11c, and the thick portion 12d is sandwiched between the case 21 and the flange portion 19. The sealed state by the ear diaphragm 12 is a reliable state.

As described above, in the diaphragm 12 stretched between the case 21 and the housing 11, the lower diaphragm member 12b of the two-layer structure that comes into contact with fuel has extremely high fuel resistance and Since it is made of fluororubber having chemical resistance, the fuel resistance and alcohol resistance of the diaphragm 12 can be improved. Further, although fluororubber is much more expensive than NBR, since only the lower diaphragm member 12b is made of fluororubber, the cost is higher than when the entire diaphragm 12 is made of fluororubber. Can be suppressed.

On the other hand, since the annular rib 12c is bulged on the upper diaphragm member 12a made of NBR, the lower diaphragm member 12b made of expensive fluororubber is formed in a simple disc circular shape. Just do it. As a result, it is possible to avoid a decrease in yield when the annular rib 12c is formed on the diaphragm member 12b made of expensive fluororubber, and it is possible to prevent an increase in cost due to the decrease in yield. The cost increase can be further suppressed.

[0025]

[Effect of device]

 As described above, according to the present invention, of the two-layer structure diaphragm, only the lower diaphragm member on the control valve chamber side is made of fluororubber, and the lower diaphragm member is the upper diaphragm on the fluid pressure chamber side. Since the diameter is smaller than that of the member and the annular rib is formed to bulge on the upper diaphragm member, it is possible to improve fuel resistance and chemical resistance while suppressing an increase in manufacturing cost.

[Brief description of drawings]

1 shows a fuel pressure control valve according to an embodiment of the present invention, (a) is a side sectional view and (b) is an enlarged partial sectional view.

[Explanation of symbols]

10 ... Fuel pressure control valve, 11 ... Housing, 11c ... Annular groove, 12 ... Diaphragm, 12a ... Upper diaphragm member, 12b ... Lower diaphragm member, 12c ... Annular rib, 12d ... Thick part, 13 ... Spherical valve body, 14 ... Fuel introduction path, 15 ... Fuel discharge path, 15a ... Pipe press-fitting hole, 16 ...
Control valve chamber, 17 ... Return pipe, 18 ... Valve spring, 19 ... Flange portion, 20 ... Negative pressure chamber, 21 ... Case, 22 ... Holding hole, 23 ... Receptor, 24 ... Support plate, 25
… Return spring.

Claims (1)

[Scope of utility model registration request] 1. A case that forms a fluid pressure chamber together with a diaphragm is fixed to a housing that forms a control valve chamber together with the diaphragm, and the periphery of the diaphragm is sandwiched between the case and the housing. A pressure control valve, which is formed of a rubber member having a two-layer structure, and in which an annular rib bulgingly formed on a diaphragm is inserted into an annular groove formed in a diaphragm mounting portion of a housing. Among the diaphragms, the lower diaphragm member on the control valve chamber side is made of fluororubber, and the lower diaphragm member is formed to have a smaller diameter than the upper diaphragm member on the fluid pressure chamber side. An annular rib is formed to bulge in a region surrounding the outer peripheral side of the side diaphragm member. The pressure control valve, wherein the door.