JPH0953545A - Fuel pressure control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel pressure control valve to reduce the number of parts, the number of assembly processes, and reduce cost by a method wherein a fuel pressure in a fuel piping is made constant to an intake pipe pressure in an injection position. SOLUTION: A diaphragm 20 by which a housing H is partitioned into a fuel chamber 2 and a spring chamber 3 is formed of a rubber material, and an on-off valve 22 to open and close a valve seat 21 is formed of a rubber material integrally with the diaphragm 20. A retainer 23 is arranged on the surface 20B on the spring chamber side of the diaphragm 20 in such a state to make contact therewith, and the spring force of a spring 24 arranged in a compression state in the spring chamber 3 is transmitted to the diaphragm 20 and the on-off valve 22 through the retainer 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pressure control valve used in a fuel injection device of an internal combustion engine, and this fuel pressure control valve outputs an amount of fuel injected from the fuel injection valve from an ECU. To make it proportional to the energizing time
The fuel pressure in the fuel pipe is compared with the intake pipe pressure at the injection position.
It is a pressure regulator that keeps it constant.

[0002]

2. Description of the Related Art A conventional fuel pressure control valve is shown in FIG. Reference numeral 1 is a diaphragm that divides the housing H into a fuel chamber 2 and a spring chamber 3. A fuel inflow passage 4 and a fuel return passage 5 are opened in the fuel chamber 2, and the spring chamber 3 is connected to the intake pipe. The negative pressure introducing passage 6 is opened.
The lower retainer 7 is provided on the fuel chamber side surface 1A of the diaphragm 1.
And the upper retainer 8 is disposed on the spring chamber side surface 1B of the diaphragm 1, and the upper end 7A of the lower retainer 7 extends through the diaphragm 1 and the upper retainer 8 toward the upper side, and the upper retainer 8 The lower retainer 7, the diaphragm 1, and the upper retainer 8 are integrally fixed to each other by expanding and crimping the protruding upper end 7A toward the upper retainer 8 to the side. On the lower surface of the lower retainer 7, an on-off valve 9 made of a rubber material is caulked and integrally fixed, and a valve seat disposed at the open end of the fuel return passage 5 into the fuel chamber 2. 10 is
The opening / closing valve 9 controls opening / closing. Reference numeral 11 denotes a spring that is compressed within the spring chamber 3 and presses the diaphragm 1 toward the fuel chamber 2 side via the upper retainer 8. To block.

[0003]

The conventional fuel pressure control valve has the following problems. (1) It is necessary to provide the diaphragm 1 with the lower retainer 7, the on-off valve 9, and the upper retainer 8, and the number of parts increases, which increases the cost of parts, so that an inexpensive fuel pressure control valve cannot be provided. (2) The on-off valve 9 is caulked and fixedly arranged in the lower retainer 7, and the upper end 7A of the lower retainer 7 is inserted into the diaphragm 1 and the upper retainer 8, and then the upper end 7A of the lower retainer 7. Are enlarged and crimped toward the upper retainer 8. According to the above, the caulking work and the work of attaching the lower retainer 7 and the upper retainer 8 to the diaphragm are required twice, which increases the number of assembling steps, increases the manufacturing cost, and reduces the fuel pressure. Cannot provide control valve.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an inexpensive fuel pressure control valve having a small number of parts and a small number of assembling steps.

[0005]

To achieve the above object, the fuel pressure control valve according to the present invention has a housing in which a diaphragm is divided into a spring chamber and a fuel chamber, and a fuel inflow passage is opened in the fuel chamber. At the same time, a valve seat that connects to the fuel return passage that is opened and closed by an on-off valve that moves integrally with the diaphragm is opened.On the other hand, a spring that presses the diaphragm toward the fuel chamber is contracted in the spring chamber and connects with the intake pipe In the fuel pressure control valve having the negative pressure introduction passage opened, the diaphragm is made of a rubber material, and the side surface of the diaphragm of the fuel chamber is made of a rubber material. The first feature is that one end of the spring compressed in the spring chamber is brought into contact with the side face of the diaphragm spring chamber through the retainer. .

Further, in the fuel pressure control valve of the present invention, the spring is a conical coil spring whose conical diameter becomes smaller toward the retainer, while the valve seat is made of a synthetic resin material. It is a feature of.

According to the first feature, since the on-off valve is integrally formed with the diaphragm and a single retainer is prepared, the number of parts can be reduced, and the retainer is in contact with the side surface of the diaphragm spring chamber. Since the fuel pressure control valve can be arranged, the number of assembling steps can be reduced and an inexpensive fuel pressure control valve can be provided. Further, according to the second feature, since the spring is a conical coil spring, the spring force can be directed toward the center of the on-off valve including the diaphragm,
The opening of the valve seat can be controlled accurately. Further, since the valve seat is made of the synthetic resin material, it is possible to prevent the on-off valve and the valve seat from being elastic.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the fuel pressure control valve of the present invention will be described below with reference to FIG. The same reference numerals are used for the same structural parts as in FIG. The housing H is divided into a fuel chamber 2 and a spring chamber 3 by a diaphragm 20, a fuel inflow passage 4 and a fuel return passage 5 are opened in the fuel chamber 2, and a negative pressure connected to the intake pipe is provided in the spring chamber 3. The introduction path 6 is opened and arranged. The fuel return passage 5 is formed in the bottom portion of the bottomed tubular portion H1 having a relatively small diameter, and the valve seat 21 is inserted and arranged in the bottomed tubular portion H1.
The valve seat 21 is made of a synthetic resin material such as nylon, and has an upper end opened substantially at the center of the fuel chamber 2 and a lower end connected to the fuel return passage 5. Further, the diaphragm is made of a rubber material, and an opening / closing valve 22 for opening / closing the valve seat 21 is integrally formed with the diaphragm on the side surface 20A of the fuel chamber. That is, the opening / closing valve 22 is simultaneously formed integrally with the rubber material when forming the diaphragm 20. Reference numeral 23 denotes a bottomed cup-shaped retainer disposed on the spring chamber side surface 20B of the diaphragm 20, and between the retainer 23 and the upper bottom portion H2 of the housing H, the cone diameter A thereof moves toward the retainer 23. The cone spring 24 having a small diameter is contracted.

The fuel pressure control valve having the above structure is assembled as follows. Bottomed cylindrical portion H of the lower housing H
After inserting and arranging the valve seat 21 in 1, the on-off valve 22 integrally formed with the diaphragm 20 is arranged on the valve seat 21 so as to face each other, and then the spring chamber side surface 2 of the diaphragm 20 is arranged.
0B, the retainer 23 is arranged, and the upper housing and the lower housing are caulked and fixed in a state where the cone coil spring is contracted between the retainer 23 and the upper bottom portion H2.

According to the above, the outer peripheral end of the diaphragm 20 is sandwiched between the upper housing and the lower housing, the opening / closing valve 22 is arranged so as to face the opening of the valve seat 21 to the fuel chamber 2, and the fuel chamber of the diaphragm 20 is arranged. The retainer 23 arranged on the side surface 20A is a conical coil spring 24.
The diaphragm 20 including the on-off valve 22 is elastically biased toward the fuel chamber 2 by the spring force of.

When the fuel pressure in the fuel pipe acting in the fuel chamber 2 via the fuel inflow passage 4 and the negative pressure in the intake pipe acting in the spring chamber 3 via the negative pressure introducing passage 6 are changed, The diaphragm 20 moves in response to the pressure change to open / close the valve 22 to control the opening of the valve seat 21 to control the amount of fuel returned to the fuel return passage 5, thereby keeping the fuel pressure in the fuel pipe constant. It was held in.

According to the fuel pressure control valve of the present invention, since the opening / closing valve 22 and the retainer 23, which are integrally formed with the diaphragm 20, may be prepared as the components related to the diaphragm 20, the conventional fuel pressure control valve is provided. The number of parts can be greatly reduced as compared with, and the cost of parts can be reduced. Also, the assembly is simply the diaphragm 20, the retainer 23, the cone spring 2
4 need only be arranged, and since it is not necessary to fix those parts by caulking or the like, the assembly can be performed very easily. Further, the conical coil spring 24 is used as the spring for pressing the diaphragm 20 including the on-off valve 22 toward the fuel chamber 2 side.
Since 2 can be directed toward the center and pressed against the valve seat 21,
Since the relative positional relationship between the valve seat 21 and the opening / closing valve 22 and the closing position of the opening / closing valve 22 with respect to the valve seat 21 can be accurately controlled, the opening control and the fully closing control of the valve seat 21 can be performed extremely accurately. Furthermore, since the valve seat 21 is made of a synthetic resin material, it is possible to reduce the tension between the on-off valve 22 made of a rubber material and the valve seat 21.

[0013]

As described above, according to the fuel pressure control valve of the present invention, the number of parts and the number of assembling steps can be reduced, so that the manufacturing cost can be reduced, and thus the inexpensive fuel pressure control valve can be provided. Furthermore, the controllability of the valve seat by the on-off valve and the slackness between the valve seat and the on-off valve can be suppressed, and good fuel pressure control can be performed against pressure changes, and a highly reliable fuel pressure control valve can be provided.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a fuel pressure control valve according to the present invention.

FIG. 2 is a vertical sectional view showing a conventional fuel pressure control valve.

[Explanation of symbols]

 3 Spring Chamber 20 Diaphragm 20A Fuel Chamber Side 20B Spring Chamber Side 21 Valve Seat 22 Open / Close Valve 23 Retainer 24 Conical Coil Spring

Claims (2)

[Claims] 1. A housing is divided into a spring chamber and a fuel chamber by a diaphragm, and a fuel inflow passage is opened in the fuel chamber and is connected to a fuel return passage opened and closed by an opening / closing valve that moves integrally with the diaphragm. Open the valve seat,
On the other hand, in the fuel pressure control valve in which a spring for pressing the diaphragm toward the fuel chamber is contracted in the spring chamber and the negative pressure introducing passage communicating with the intake pipe is opened, the diaphragm is formed of a rubber material and the diaphragm is formed. An on-off valve 22 that is made of a rubber material and opens and closes the valve seat 21 is integrally formed on the fuel chamber side surface 20A of the valve 20. The fuel pressure control valve which is in contact with the side surface 20B of the spring chamber. 2. The fuel according to claim 1, wherein the spring is a conical coil spring whose conical diameter A is smaller toward the retainer 23, while the valve seat is made of a synthetic resin material. Pressure control valve.