GAS FUEL SUPPLY REGULATOR

Abstract

In a gas fuel supply regulator, a valve lever a base end of which is firmly fixed to a valve body by a pin arranged on a side of a valve seat of a valve, a rear surface at a leading end of which is supported by a control pressure set spring, and on a surface of which a rod holding recessed part that holds a rod of a diaphragm is formed is slidably arranged, a valve body is opened by fuel of before pressure reduction which fuel is introduced from a fuel inlet to a pressure regulation chamber through the valve, the valve lever is slid, the diaphragm is operated through a coupling mechanism between the rod holding recessed part of the valve lever and the rod of the diaphragm, and pressure of the fuel in the pressure regulation chamber is reduced.

Claims

1. A gas fuel supply regulator comprising: a valve being provided in a fuel inlet to a pressure regulation chamber comparted by a diaphragm from a side of a back pressure chamber that communicates with an atmosphere side; and a valve lever including a base end that is firmly fixed to a valve body by a pin arranged on a side of a valve seat of the valve, a rear surface at a leading end of which is supported by a control pressure set spring provided according to atmospheric pressure on the side of the back pressure chamber, and a surface having a rod holding recessed part slidably arranged thereon and that holds a rod protruded to a side of the pressure regulation chamber of the diaphragm, wherein the valve body is opened by fuel of before pressure reduction which fuel is introduced from the fuel inlet to the pressure regulation chamber through the valve, the valve lever is slid, the diaphragm is operated through a coupling mechanism between the rod holding recessed part of the valve lever and the rod of the diaphragm, and pressure of the fuel in the pressure regulation chamber is reduced, and wherein a cross section of the rod holding recessed part of the valve lever is V-shaped.

2. The gas fuel supply regulator according to claim 1, wherein a tip part of the rod of the diaphragm, which rod is supported by the rod holding recessed part, is formed to have an inclined surface converging toward a center.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0014] FIG. 1 is a schematic sectional view illustrating a preferred embodiment of the present invention;

[0015] FIG. 2 is a view for describing a main part in the embodiment illustrated in FIG. 1;

[0016] FIGS. 3A to 3C are views for describing an initial state and an operating state of the embodiment illustrated in FIG. 1;

[0017] FIG. 4 is a view for describing a contact part between a rod of a diaphragm and a valve lever in a very low flow rate region (state in which valve is not opened much) in the embodiment illustrated in FIG. 1;

[0018] FIG. 5 is a pressure regulation characteristic graph illustrating a relationship between negative pressure and a flow rate in a pressure regulation chamber in the embodiment illustrated in FIG. 1 and that in an example of a related art;

[0019] FIG. 6 is a schematic sectional view illustrating an example of a related art;

[0020] FIG. 7 is a view for describing a main part in the example of the related art illustrated in FIG. 6;

[0021] FIGS. 8A to 8C are views for describing an initial state and an operating state of the example of the related art illustrated in FIG. 6; and

[0022] FIG. 9 is a view for describing a contact part between a rod of a diaphragm and a valve lever in a very low flow rate region (state in which valve is not opened much) in the example of the related art illustrated in FIG. 6.

DETAILED DESCRIPTION

[0023] In the following, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

[0024] FIG. 1 is a view illustrating a preferred embodiment of the present invention and is basically similar to an example of a related art illustrated in FIG. 6, a detailed description thereof being omitted. In particular, as illustrated in FIG. 2, a point that a cross section of a rod holding recessed part 91 of a valve lever 9 which part supports a rod 21 of a diaphragm 2 is formed in a conical shape a cross section of which is V-shaped is different.

[0025] More specifically, as illustrated in FIG. 7, in a gas fuel supply regulator in the related art, with a rod holding recessed part 91 that is a contact part between a valve lever 9 and a rod 21 of a diaphragm 2 being formed in a spherical surface shape or a round surface shape in order to reduce a positional deviation generated in conversion of a linear motion of the rod 21 of the diaphragm 2 into an arc motion of the valve lever 9 as much as possible, the contact part of the valve lever 9 and the rod 21 of the diaphragm 2 has a shape with which it is expected that the rod 21 of the diaphragm 2 slides on a spherical surface part (or round surface part) and goes back to an original position. On the other hand, since a cross section of a rod holding recessed part 91 of a valve lever 9 is formed in a conical shape a cross section of which is V-shaped in the present embodiment, a rod 21 is constantly arranged at a center position of the rod holding recessed part 91 even when an arc motion of the valve lever 9 during pressure regulation is converted into a linear motion of the rod 21 of a diaphragm 2.

[0026] Thus, according to the present embodiment, as illustrated in FIG. 3B, a contact point is not moved from an initial state illustrated in each of FIG. 3A and FIG. 3C (free behavior in rod 21 of diaphragm 2 is controlled) even when the diaphragm 2 is operated, while a contact point with the rod 21 of the diaphragm 2 is deviated in the example of the related art in which the rod holding recessed part 91 with a spherical surface (or round surface) is included and which is illustrated in FIGS. 8A to 8C.

[0027] As illustrated in FIG. 4, in a very low flow rate region (state in which valve 5 is not opened much), even when a lever ratio varies, a contact position between the rod 21 of the diaphragm 2 and the valve lever 9 does not vary and a diaphragm load effort point does not vary with respect to a supplied pressure point a, and a load point b of a control pressure set spring 6 unlike the example of the related art illustrated in FIG. 9. Thus, a balance is not lost and a difference from an initial set value is not generated, and there is not a problem of deterioration in controllability/reproducibility of slight pressure.

[0028] That is, with respect to a contact part that forms a coupling mechanism between the valve lever 9 and the rod 21 of the diaphragm 2 of when the valve is opened, a variation in a contact point due to a relative positional deviation generated during a linear motion of the rod of the diaphragm and an arc motion of the valve lever can be controlled and controllability/reproducibility can be improved.

[0029] In particular, even when a diaphragm 2 of a thin film thickness is used, an expected effect can be acquired since the rod 21 of the diaphragm 2 is arranged at a position of the rod holding recessed part 91 of the valve lever 9.

[0030] Also, FIG. 5 is a graph illustrating a pressure regulation characteristic relationship indicating a relationship between magnitude of a flow rate and magnitude of negative pressure in a pressure regulation chamber 3 in each of the present embodiment and the example of the related art. It is understood that there is a reproduction variation in negative pressure in the pressure regulation chamber and reproducibility is low in a stationary test when a flow rate varies from an increase to a decrease in the example of the related art in which the valve lever 9 including the rod holding recessed part 91 with a spherical surface or round surface shape is included and which is illustrated in FIG. 6 to FIG. 9 but there is no reproduction variation in the present embodiment.

[0031] Also, in the present embodiment, a tip part of the rod 21 in the diaphragm 2 which rod is supported by the rod holding recessed part 91 is formed in a conical shape converging toward a center. Thus, when being supported by the rod holding recessed part 91 formed in a conical shape a cross section of which is V-shaped, a leading end of the rod 21 fits to a center at a bottom part of the rod holding recessed part 91 and is supported in such a manner that central axes of the two are overlapped. For example, the rod 21 is arranged at a position of the rod holding recessed part 91 of the valve lever 9 without being further deviated compared to a case where a rod 21 a leading end of which is columnar is used (not illustrated). Thus, it is possible to more securely acquire a beneficial effect.