JPS62162767A - Fuel pressure control valve - Google Patents

Abstract

PURPOSE:To control the fuel in a fuel chamber to a prescribed pressure state by arranging fulcrum members so as to be opposed each other onto the both surfaces of the outer part of a metal diaphragm and providing the sufficient durability for the diaphragm, independently of the characteristics of the fuel. CONSTITUTION:When the fuel pressure increases over the prescribed pressure determined according to the pressure in a back pressure chamber 6 and the urging force of a spring 16, a diaphragm 4 made of stainless steel shifts to the back pressure chamber 6 side, and a movable valve 12 shifts and is opened, and fuel flows out through an effluence pipe 8. Since the diaphragm 4 is held onto the housings 2 and 3, in the state where O-rings 18 and 19 are installed so as to be opposed each other onto the both surfaces along the outer peripheral surface part of the diaphragm 4, the center part of the diaphragm 4 can be shifted sufficiently, having the O-rings 18 and 19 as fulcrums. Therefor, the fuel in a fuel chamber can be controlled sufficiently to a prescribed pressure state.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a fuel pressure control valve.

[Conventional technology]

Conventionally, for example, in the fuel piping system of a vehicle internal combustion engine equipped with an electronically controlled fuel injection device, in order to maintain a predetermined pressure difference between the pressure of the fuel injected from the fuel injection valve and the pressure in the intake pipe. A fuel pressure control valve is provided (for example, Utility Model Application No. 60-143159).

The diaphragm included in the fuel pressure control valve currently in use is generally made of a resin woven fabric coated on both sides with rubber.

[Problem that the invention seeks to solve]

However, the rubber layer of the diaphragm can deteriorate significantly depending on the nature of the fuel used. For example, with alcohol-mixed fuel or inferior materials containing many impurities, the rubber layer deteriorates and peels off, causing the diaphragm to become airtight. The problem is that there is a risk that people will lose their sexuality.

Therefore, an object of the present invention is to provide a fuel pressure control valve that exhibits sufficient resistance to any type of fuel and that can operate satisfactorily.

[Means for solving problems]

In order to solve the above problems, in the present invention, a back pressure chamber partitioned by a diaphragm and having a spring inside, an inflow pipe through which fuel flows, and an outflow pipe through which fuel flows out are provided in the housing. a fuel chamber that faces the opening of the outflow pipe and has a valve therein that adjusts the outflow amount of fuel by cooperating with the diaphragm, and controls the pressure of the fuel in the fuel chamber into the back pressure chamber. In the fuel pressure control valve, the diaphragm is made of a thin metal disc, and the fuel pressure control valve is controlled to be in equilibrium with the pressure determined by the pressure of the spring and the biasing force of the spring provided in the back pressure chamber.
The outer peripheral portion of the diaphragm is connected to the housing,
The fuel pressure control valve is characterized in that annular fulcrum members are disposed on both sides of the outer portion of the diaphragm so as to face each other, and are held by being sandwiched together with the fulcrum members.

[Effect]

According to the above configuration, by using a metal diaphragm, sufficient resistance can be provided regardless of the fuel properties, and furthermore, the diaphragm has a disk center that flexibly moves with the fulcrum member as a fulcrum. The pressure of fuel within the fuel chamber is controlled.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the fuel pressure control valve 1 shown in FIG. 1, reference numerals 2 and 3 are metal housings each having a substantially cup shape,
A thin disc-shaped metal diaphragm 4 made of stainless steel, for example, is provided inside the diaphragm 4.
The diaphragm 4 divides the inside of the housing 2.3 into two chambers. In the figure, the fuel chamber 5 is formed by the housing 2 and the diaphragm 4.
, a back pressure chamber 6 is formed by the housing 3 and the diaphragm 4.

The housing 2 includes an inflow pipe 7 for allowing fuel pumped by a fuel pump (not shown) to flow into the fuel chamber 5, and an outflow pipe for flowing fuel out of the fuel chamber 5 and returning it to a fuel tank (not shown). 8 are each fixed together with a reinforcing plate 9.10. One end of the outflow pipe 8 protrudes into the fuel chamber 5, and a pipe 11 is press-fitted into the tip thereof. Note that the tip of the pipe 11 is fixed so as to protrude from the end of the outflow pipe 8. Furthermore, a movable valve 12 is provided between the diaphragm 4 and the end surface of the pipe 11.
The movable valve 12 has one end in contact with a step 13 formed on the outer periphery of the outflow pipe 8, is arranged along the outer periphery of the outflow pipe 8, and the other end is in contact with the movable valve 12. It is urged in a direction away from the end surface of the pipe 11 by the abutting spring 14 . The movable valve 12 is pressed against the diaphragm 4 by the urging force of a spring 14.

A pressure guiding pipe 15 to which a rubber pipe or the like for transmitting pressure on the downstream side of the throttle of an intake pipe (not shown) to the back pressure chamber 6 is connected to the housing 3 is welded and fixed. Further, a spring 16 is provided in the back pressure chamber 6, and the diaphragm 4
A receiver plate 17 is disposed between the diaphragm 4 and the spring 16 so as to be in contact with the diaphragm 4. Therefore, the diaphragm 4 is pressed toward the fuel chamber s by the urging force of the spring 16. Note that the urging force of the spring 16 is adjusted by deforming the end portion 3a of the housing 3. Further, the biasing force of the spring 14 is smaller than the biasing force of the spring 16, and is set to the minimum biasing force that allows the movable valve 12 to follow the movement of the diaphragm 4.

Incidentally, the diaphragm 4 is held by the housing 2.degree. 3, and FIG. 2 shows the holding structure thereof. In FIG. 2, two O-rings 18 and 19 are arranged on the outer periphery of the diaphragm 4 so as to sandwich the diaphragm 4 on both sides of the diaphragm 4, and protrude toward the outer periphery of the housing 2 via an auxiliary plate 20. Fold back the flange portion 2a and attach the auxiliary plate 20.0 ring 18.
, diaphragm 4, and O-ring 19 are fixed in layers. Further, the flange portion 3b of the housing 3 is folded back along the flange portion 2a of the housing 2. Note that a gasket is provided between the flange portion 3b of the housing 3 and the folded portion of the flange portion 2a of the housing 2. Further, a raised portion 20a is formed on the outer peripheral edge of the auxiliary plate 20, and an O-ring 18 is formed on the outer peripheral edge of the auxiliary plate 20.
．． 19 and a layered space in which the diaphragm 4 is arranged. Further, the O-rings 18 and 19 ensure sealing between the fuel chamber 5 and the back pressure chamber 6.

In the above configuration, the inside of the fuel chamber 5 is filled with fuel from the inflow pipe 7, and the pressure acts on the diaphragm 4.

Then, the pressure of the fuel is equal to the pressure inside the back pressure chamber 6 and the spring 16.
When the pressure exceeds a predetermined pressure determined by the biasing force of
Fuel flows out via the outflow pipe 8. The pressure of the fuel is maintained at the predetermined pressure by causing the fuel in the fuel chamber 5 to flow out while being throttled by the movable valve 12.

By the way, the diaphragm 4 has an O ring of 18.1 at the outer circumference.
Since the O-rings 18 and 19 are held as fulcrums, the center of the diaphragm 4 is displaced according to the fuel pressure, the pressure inside the back pressure chamber 6, and the biasing force of the spring 16. .

Therefore, according to the above configuration, the metal diaphragm 4 provides sufficient resistance against any kind of fuel.

Furthermore, since the diaphragm 4 is held in the housing 2°3 with O-rings 18.19 provided on both sides along the outer circumference of the diaphragm 4 so as to face each other, the O-rings 18.19 are used as fulcrums. As a result, the center portion of the diaphragm 4 can be sufficiently displaced.

Incidentally, in the above embodiment, the movable valve 12 and the receiver plate 17 were provided in contact with the diaphragm 4, but each may be fixed to the diaphragm 4 by tightening or welding or other means. I don't mind if you do. Note that when the movable valve 12 is fixed to the diaphragm 4, the spring 14 is not needed.

Further, in the above embodiment, the O-rings 18 and 19 are used to both ensure the sealing performance between the fuel chamber 5 and the back pressure chamber 6 and to function as a fulcrum when the diaphragm 4 is displaced. However, the sealing performance between the fuel chamber 5 and the back pressure chamber 6 is ensured in other parts (for example, a sealing member is provided between the auxiliary plate 20 and the re-inserted part of the flange part 2 of the housing 2 a). ), the members provided on both sides of the outer circumferential portion of the diaphragm 4 that act as fulcrums for the displacement of the diaphragm 4 may have other structures. An annular raised portion may be formed on both the opposing portion and the portion of the auxiliary plate 20 that opposes the diaphragm 4, and this raised portion may function as a fulcrum for displacement of the diaphragm 4.

(Effects of the Invention) As described above, according to the present invention, a back pressure chamber partitioned by a diaphragm and having a spring inside, an inflow pipe through which fuel flows, and an outflow pipe through which fuel flows out are provided in the housing. a fuel chamber having therein a valve that is provided and faces the opening of the outflow pipe and that adjusts the outflow stage of the fuel by cooperating with the diaphragm; In a fuel pressure control valve that controls the pressure in a back pressure chamber to be in equilibrium with the pressure determined by the biasing force of the spring provided in the back pressure chamber, the diaphragm is made of a thin metal disc and ,
The outer peripheral portion of the diaphragm is connected to the housing,
The fuel pressure control valve is characterized in that annular fulcrum members are disposed on both surfaces of the external portion of the diaphragm so as to face each other, and are held by being sandwiched together with the fulcrum members. It is possible to realize a fuel pressure control valve that has sufficient resistance regardless of the fuel properties of the diaphragm, and the central part of the diaphragm can be sufficiently displaced using the fulcrum member provided on the outer peripheral part of the diaphragm as a fulcrum. This has the advantageous effect that the fuel in the fuel chamber can be sufficiently controlled to a predetermined pressure state.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
FIG. 3 is a partial cross-sectional view showing the main part of the figure. 1...Fuel pressure control valve, 2.3...Housing, 4
... diaphragm, 5 ... fuel chamber, 6 ... back pressure chamber, 7 ... inflow pipe, 8 ... outflow pipe, 12 ... movable valve, 16 ... spring, 18.19 ...O-ring,
20... Auxiliary board.

Claims (1)

[Scope of Claims] A back pressure chamber partitioned by a diaphragm and having a spring inside, an inflow pipe through which fuel flows, and an outflow pipe through which fuel flows out are provided in the housing, and are opposed to the opening of the outflow pipe. and a fuel chamber having a valve therein which adjusts the outflow amount of fuel by cooperating with the diaphragm, and controls the pressure of the fuel in the fuel chamber to the pressure in the back pressure chamber and the back pressure chamber. In the fuel pressure control valve, the diaphragm is made of a thin metal disk, and the diaphragm is made of a thin metal disc, and
The outer peripheral portion of the diaphragm is connected to the housing,
A fuel pressure control valve characterized in that annular fulcrum members are disposed on both sides of an external portion of the diaphragm so as to face each other, and are held by being sandwiched together with the fulcrum members.