JP2531136B2 - Fuel pressure regulator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel pressure regulator.

[Conventional technology]

Conventionally, for example, in a fuel piping system of a vehicle internal combustion engine equipped with an electronically controlled fuel injection device, in order to maintain the pressure of fuel injected from a fuel injection valve at a predetermined pressure difference with respect to the pressure in the intake pipe. Is equipped with a fuel pressure regulator.
In such a fuel pressure regulator, in order to adjust the pressure in the fuel chamber, a valve for adjusting the amount of fuel flowing out is provided at the outflow pipe inlet. In addition, in order to improve the restartability of the internal combustion engine, it is necessary to maintain the pressure in the fuel chamber even after the internal combustion engine is stopped. It was designed to be held at the same time (for example, No. 57-99959, No. 56, No. 56, No.
-143565).

[Problems to be solved by the invention]

However, since this closed state is achieved by abutting the seal surfaces made of metal surfaces, the surface finish of these seal surfaces is made with extremely high accuracy in order to improve the sealing performance. There was a problem that had to be done.

There is also a configuration in which the valve is made of an elastic material to improve the sealing property (for example, Japanese Patent Laid-Open No. 58-214077). However, when the elastic member is exposed to high temperature fuel, the elastic member is liable to change its shape due to swelling. Therefore, there is a problem in that the amount of outflowing fuel is affected and the pressure in the fuel chamber is not properly adjusted.

Also, as in Japanese Patent Laid-Open No. 60-240863, there is known one in which an auxiliary sheet is provided to bring rigid materials into contact with each other in order to prevent deformation of the elastic material (material). In order to maintain the above value, the elastic material is repeatedly deformed each time the valve is opened and closed, so that the deformation of the elastic material cannot be prevented. Further, if the elastic material is deformed, a gap may be created in the contact portion of the elastic materials due to the auxiliary sheets in which the rigid materials are brought into contact with each other, which may deteriorate the sealing performance. In such a configuration in which the elastic material is used for the valve portion, accurate pressure adjustment may not be realized due to the easiness of deformation of the elastic material with an emphasis on the sealing property.
It was difficult to achieve both accurate pressure adjustment and excellent sealing performance over a long period of time.

Therefore, in view of the problems of the above-mentioned conventional techniques, the present invention provides a fuel pressure regulator that can achieve an excellent sealing property for a long period of time without using precision processing while realizing accurate pressure adjustment. To aim.

[Means for solving problems]

Therefore, in the present invention, in the fuel pressure regulator for adjusting the pressure of the fuel to a predetermined pressure, the pressure regulator is provided in the fuel chamber into which the pressurized fuel is introduced, receives the pressure of the fuel, and is displaced in accordance with this pressure. A member, an outflow passage that opens into the fuel chamber and allows the fuel in the fuel chamber to flow out, and an elastic member that is provided in the outflow passage and that is provided in the opening / closing portion for fuel sealing, and that is used for displacement of the pressure receiving member. A valve that opens and closes the outflow passage in response to the opening pressure when the fuel pressure in the fuel chamber is equal to or higher than the opening pressure that is lower than the predetermined pressure; and a valve that is provided in the outflow passage in series with the on-off valve. A valve that also opens and closes the outflow passage according to the displacement of the pressure receiving member, and is closed until the pressure in the fuel chamber becomes equal to or higher than the predetermined pressure, and the pressure of fuel in the fuel chamber is equal to or higher than the predetermined pressure. Then the valve opens Has a configuration that and a metering valve to maintain the pressure of fuel in the fuel chamber to the predetermined pressure.

[Action]

In the present invention, the pressure receiving member is displaced according to the fuel pressure, and the on-off valve and the metering valve, which are provided in series in the outflow passage, open and close the outflow passage according to the displacement amount of the pressure receiving member.

Particularly in the present invention, a difference is given to the pressure at which the on-off valve opens and the pressure at which the metering valve opens, and the on-off valve is opened at an opening pressure lower than the predetermined pressure to be maintained as the fuel pressure regulator. The valve is opened, and the metering valve is opened at a pressure equal to or higher than a predetermined pressure that should be maintained as the fuel pressure regulator. Therefore, when the fuel pressure in the fuel chamber rises and reaches the valve opening pressure, the on-off valve opens first, and when the fuel pressure further rises and reaches the predetermined pressure, the metering valve opens and the fuel in the fuel chamber The fuel pressure is prevented from rising from the outflow passage. When the fuel pressure in the fuel chamber is about to drop below the predetermined pressure, the metering valve is closed again, and the opening / closing operation of the metering valve maintains the fuel pressure in the fuel chamber at the predetermined pressure.

Moreover, in the present invention, since the elastic member is interposed in the opening / closing portion of the on-off valve, the fuel is surely prevented from flowing out of the outflow passage when the on-off valve is closed, and the on-off valve ensures a reliable sealing property. In addition, since the opening pressure of this on-off valve is lower than the predetermined pressure that should be maintained as a fuel pressure regulator, the elastic member is deformed more than a metering valve that repeats opening and closing to adjust the fuel pressure to a predetermined pressure. Frequency is reduced.

As described above, in the present invention, the fuel is mainly sealed by the on-off valve, the fuel pressure is mainly adjusted by the metering valve, and the valve opening pressure at which the on-off valve opens is the predetermined pressure at which the metering valve opens. By adopting the configuration of lowering the pressure, it is possible to obtain accurate sealing of the fuel over a long period of time by suppressing the deformation of the elastic member used for the on-off valve while realizing accurate fuel pressure adjustment by the metering valve. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

A fuel pressure regulator 1 shown in FIG. 1 is mounted on an internal combustion engine for a vehicle equipped with an electronically controlled fuel injection device, 2 is a fuel chamber housing, 3 is a back pressure chamber housing, and each has a cup shape. It is made of metal. Reference numeral 4 denotes a thin disk-shaped, for example, a diaphragm having a double structure of a fuel resistant rubber and a base cloth. The peripheral edges of both housings 2 and 3 are sandwiched by the peripheral edge of the diaphragm 4 and the outside air is exposed to the housing 2. The fuel in the fuel chamber 5 does not enter the back pressure chamber 6 and the air in the back pressure chamber 6 does not enter the fuel chamber 5.

In the housing 2, a substantially cylindrical inflow pipe 7 for inflowing the fuel pumped into the fuel chamber 5 by a fuel pump (not shown), and a fuel flowing out from the fuel chamber 5 and returned to a fuel tank (not shown). A substantially cylindrical outflow pipe 8 for welding is fixed by welding together with a mounting plate 9 and a reinforcing plate 10. Further, one end of the outflow pipe 8 projects into the fuel chamber 5.

By the way, in the back pressure chamber 6, a tray 11 is provided in the substantial center of the diaphragm 4, and a spring 12 is provided to urge the diaphragm 4 toward the fuel chamber 5 side.
And the saucer 11 are arranged between them. Housing 3
Is a dynamic pressure pipe to which a rubber pipe or the like for transmitting a negative pressure from a throttle downstream side of an intake pipe (not shown) into the back pressure chamber 6 is connected.
13 is fixed by welding. The end 3a of the housing 3
By deforming, the biasing force of the spring 12 is adjusted. The tray 11 is provided with the diaphragm 4 from the fuel chamber 4.
It is fixed to the diaphragm 4 by a seal valve 14 which penetrates through substantially the center of the diaphragm. That is, the diaphragm 4 is held between the tray 11 and the seal valve 14.

Now, in the fuel chamber 5, an elastic member 15 such as fluororubber is baked and fixed in an annular groove formed on the end face of the seal valve 14 so as to face the end face 8a of the outflow pipe 8. This elastic member 15 is in contact with the end face 8a as shown in the figure by the urging force of the spring 12 when the internal combustion engine is at rest. In this case, the opening of the outflow pipe 8 is about 6 to 7 kg weight due to the spring force. Blocked 8b.

Further, description will be given also with reference to FIG. 2 showing a cross section of a main part of the outflow pipe 8 at different angles.

A substantially cylindrical metering valve 16 is inserted into the outflow pipe 8, and comes into contact with a spring 18 provided between a spring receiver 17 fixed to the outflow pipe 8 and the sealing valve 14. It is pressed in the axial direction. This metering valve 16 has a spherical surface formed on a head portion 16a which is a contact portion with the seal valve 14, and an edge 16b of the spherical surface.
The side surface connected to is a cylindrical surface, which is a valve portion 16c for sliding the metering valve 16 without generating strong friction while keeping the inner peripheral surface of the outflow pipe 8 liquid-tight. The edge of this valve portion 16c
Two chamfered portions 16d and 16e having a rectangular shape are formed parallel to each other from a distance l away from 16b, and reach the contact portion with the spring 18. And this chamfer 16d, 16
The gap between e and the inner wall surface of the outflow pipe 8 is the fuel passage 19, and when the metering valve 16 is lifted by l, the chamfered portion 16 of the valve portion 16c.
When d and 16e come out from the end surface 8a of the outflow pipe 8, the fuel chamber 5
Is communicated with.

Here, the urging force of the spring 12 takes into consideration the internal pressure of the back pressure chamber 5 and the pressure receiving area of the diaphragm 4, and the metering valve 16
Is set so that the fuel pressure in the fuel chamber 5 becomes a predetermined pressure at a position lifted by l, the biasing force of the spring 18 is smaller than the biasing force of the spring 12, and the metering valve 16
Is sufficient to follow the movement of the sealing valve 14 in cooperation with the diaphragm 4.

In the fuel pressure regulator 1 having the above-described structure, when the fuel flowing into the fuel chamber 5 from the inflow pipe 7 is filled, the pressure in the fuel chamber 5 acts on the diaphragm 4, and the pressure increases to some extent. When the valve opening pressure becomes lower than the predetermined pressure to be maintained as the pressure regulator, the diaphragm 4 is displaced toward the back pressure chamber 6 side against the pressure determined by the urging force of the spring 12 and the pressure inside the back pressure chamber 6. When the elastic member 15 of the seal valve 14 that cooperates with the displacement of the diaphragm 4 is separated from the end surface 8a of the outflow pipe 8, the opening 8b is opened.
Then, the metering valve 16 which is interlocked with the seal valve 14 while maintaining contact with the head portion 16a by the urging force of the spring 18 slides the valve portion 16c against the inner wall surface of the outflow pipe 8 without causing strong friction. However, if the chamfered portions 16d and 16e are in the outflow pipe 8, the fuel passage 19 is closed by the valve portion 16c and is not in communication with the fuel chamber 5. At the time when the pressure in the fuel chamber 5 further rises to reach the predetermined pressure to be maintained as the fuel pressure regulator described above, the metering valve 16 is displaced by 1 from the position shown in conjunction with the diaphragm 4, Valve
The fuel passage 19 is opened by the chamfered portions 16d and 16e of 16c projecting out of the outflow pipe 8. Then, in order to maintain the predetermined pressure in the fuel chamber 5, the surplus fuel is returned to the fuel tank (not shown) through the fuel passage 19 and the outflow pipe 8. On the other hand, when the internal pressure of the fuel chamber 5 is about to fall below a predetermined pressure, the diaphragm 4 is urged toward the fuel chamber 5 side by the spring 12, and in conjunction with this, the valve portion 16c of the metering valve 16 causes the fuel passage 19 to flow. The closing prevents the fuel pressure in the fuel chamber 5 from dropping. In this way, in the fuel pressure regulator 1, the metering valve 16 repeats the operation in accordance with the pressure in the fuel chamber 5, and the operation stroke of the metering valve 16 causes the flow passage to flow.
The outflow amount of the fuel flowing through 19 is adjusted so that the predetermined pressure in the fuel chamber 5 is maintained.

According to such an embodiment, when the internal combustion engine is stopped, that is, when the fuel pressure regulator 1 is in the non-operating state, the elastic member 15 quickly moves to the end face 8a of the outflow pipe 8 by the urging force of the spring 12. It is possible to sit down, close the opening 8b as shown in the figure, and reliably seal with the elastic sealing surface.
As a result, fuel is prevented from leaking into the outflow pipe 8 and the fuel chamber 5
Since the internal pressure can be maintained, the restartability of the internal combustion engine becomes very good. Further, since the sealing performance is ensured by the elastic member 15 in this manner, the sealing valve 14 and the end surface 8a of the outflow pipe 8 are not required to be processed with high precision, so that the processing labor can be reduced and the cost can be reduced. You can

In addition, a seal valve to prevent such fuel outflow
14 and a metering valve 16 for controlling the amount of outflowing fuel to maintain a predetermined pressure in the fuel chamber 5, the elastic member 15 swells when exposed to high temperature and high pressure fuel. Even if a shape change such as a sag occurs, it does not affect the metering of the outflow fuel at all.

Even better, the seal valve 14 is activated
Even if 8b is opened, the metering valve 16 does not open the fuel passage 19 for a constant stroke l. Therefore, the elastic member 15 is operated during operation of the internal combustion engine.
Does not collide with the end surface 8a of the outflow pipe 8, and the elastic member 15
Since it does not hurt, it is possible to secure outstanding sealing properties over a long period of time.

Further, since the seal valve 14 and the metering valve 16 are formed as separate members, even if the mounting position of the seal valve 14 with respect to the diaphragm 4 is deviated, the metering valve 16 is strong in the outflow pipe 8. Can slide without causing friction. Further, since the head portion 16a of the metering valve 16 is formed with a spherical surface, even if the urging force of the spring 18 does not necessarily press the metering valve 16 in an accurate axial direction due to a machining assembly error or the like, a seal is provided. The valve 14 and the metering valve 16 can be interlocked while surely contacting each other, and the movement of the diaphragm 4 corresponding to the pressure of the fuel chamber 5 can be accurately corresponded.

The present invention is not limited to the above embodiment.

For example, the metering valve and the seal valve may not be provided in separate members, but both may be formed in one member.

Further, in this configuration, a member provided with the metering valve and the seal valve may be configured to cooperate with a fixed pair newly fixed to the diaphragm while being in contact with the fixed pair.

〔The invention's effect〕

As described above, according to the configuration and operation of the present invention,
The fuel is sealed mainly by the on-off valve, and the fuel pressure is adjusted mainly by the metering valve. Therefore, while achieving accurate fuel pressure adjustment by the metering valve, an elastic member is used for the on-off valve to achieve a high seal. And the fuel pressure in the fuel chamber can be reliably maintained when the valve is closed, and the elastic member can be prevented from being deformed to obtain a reliable sealing property for a long period of time.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a fuel pressure regulator according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a main portion of the fuel pressure regulator shown in FIG. 1 ... Fuel pressure regulator, 4 ... Diaphragm, 5 ... Fuel chamber, 7 ...
… Inflow pipe, 8 …… Outflow pipe, 8b …… Opening, 14 …… Seal valve, 1
5: Elastic member, 16: Metering valve.

Claims (3)

(57) [Claims] 1. A fuel pressure regulator for adjusting a pressure of fuel to a predetermined pressure, the pressure receiving member being provided in a fuel chamber into which pressurized fuel is introduced, and which receives the pressure of the fuel and is displaced in accordance with the pressure. An outflow passage that opens into the fuel chamber and allows the fuel in the fuel chamber to flow out; and an elastic member for fuel sealing, which is provided in the outflow passage and is provided in the opening / closing portion, according to the displacement of the pressure receiving member. A valve for opening and closing the outflow passage, the valve being opened and closed when the fuel pressure in the fuel chamber is equal to or higher than the opening pressure lower than the predetermined pressure; and the inflow passage provided in series with the on-off valve. A valve that also opens and closes the outflow passage according to the displacement of the pressure receiving member, and is closed until the pressure in the fuel chamber becomes equal to or higher than the predetermined pressure, and the pressure of fuel in the fuel chamber becomes equal to or higher than the predetermined pressure. Then the valve opens and the fuel chamber A pressure regulator for maintaining the pressure of the fuel at the predetermined pressure. 2. The opening / closing valve is supported by the pressure receiving member facing the opening of the outflow pipe in which the outflow passage is formed, and the opening of the opening / closing valve via rubber as the elastic member. The fuel pressure regulator according to claim 1, further comprising: a seal valve that is in contact with the pressure receiving member and opens and closes the opening according to the displacement of the pressure receiving member. 3. The metering valve is provided inside the outflow passage so as to be movable according to the displacement of the pressure receiving member, and the displacement of the pressure receiving member is greater than a predetermined stroke which is larger than the valve opening displacement of the on-off valve. A valve portion (16c) that slides in contact with the inner wall of the outflow passage to close the outflow passage, and opens the outflow passage when the displacement amount of the pressure receiving member exceeds the predetermined stroke. 2. The fuel pressure regulator according to claim 1.