JPH11351094A - Fuel supply system and method of assembling same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel supply system that can be manufactured at fewer working and assembling man-hours. SOLUTION: A housing 11 is fitted with a fixed C-shaped snap ring 57, which can be placed in butt contact with a flange part 51a on a holder 51 of a pressure regulator 50, so that, the pressure regulator 50 is prevented from slipping off the housing 11 even under at least a preset pressure of fuel that a high- pressure fuel pump 1 sucks up. This expedient dispenses with threaded portions and the like in the holder 51 of the pressure regulator 50 to thus reduce its working man-hour in manufacture. The C-shaped snap ring 57 is also fixed, through elastic deformation, on the interior wall of a groove cut in the housing 11. This arrangement facilitates the fixation of the C-shaped snap ring 57 on the groove interior wall of the housing 11 to thus reduce the assembling man- hour in manufacture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel supply device for supplying high-pressure fuel to a fuel injection device of an internal combustion engine, and a method for assembling the same.

[0002]

2. Description of the Related Art Conventionally, an electromagnetic valve is disposed on a fuel suction side of a fuel pressurizing chamber, and when a solenoid valve is opened, a plunger descends to draw fuel into the fuel pressurizing chamber and close the electromagnetic valve. 2. Description of the Related Art A fuel supply device that pressurizes fuel by raising a plunger at the time of a valve is known. In such a high-pressure fuel pump as a fuel supply device, a screw portion is provided on an outer peripheral surface of a holder of a pressure regulator that regulates a fuel pressure sucked into the high-pressure fuel pump to a predetermined pressure or less. It is common practice to attach a pressure regulator to the housing of a high pressure fuel pump by coupling.

[0003]

However, in the above-mentioned conventional high-pressure fuel pump, it takes time to machine the threaded portion on the outer peripheral surface of the holder of the pressure regulator, which increases the number of machining steps during manufacturing. was there. Further, there is a problem that it takes time to perform the screw connection of the above-mentioned screw portion, and the number of assembling steps at the time of manufacturing increases.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a fuel supply device capable of reducing the number of processing steps in manufacturing.
Another object of the present invention is to provide a fuel supply device and a method for assembling the same, which can reduce the number of assembling steps during manufacturing.

[0005]

According to the fuel supply device of the first aspect of the present invention, the detachment prevention member is fixed to the housing, and the pressure regulator is set at least at a predetermined pressure of the fuel pressure sucked into the fuel supply device. Prevent it from falling out of the housing. For this reason, it is not necessary to provide a screw portion on the holder or the like of the pressure regulator. Therefore, it is possible to reduce the number of processing steps in manufacturing the pressure regulator.

Further, the pressure regulator can be firmly and easily assembled to the housing by fixing the escape prevention member to the housing, for example, by fitting or deformation of the removal prevention member. Therefore, it is possible to reduce the number of assembling steps during manufacturing.

According to the fuel supply device of the second aspect of the present invention, since the detachment preventing member is C-shaped, the detachment preventing member can be easily fixed to the housing by, for example, deformation of the detachment preventing member. . Therefore, it is possible to reduce the number of assembling steps during manufacturing.

According to the fuel supply device of the third aspect of the present invention, since the detachment preventing member has a pin shape, the detachment preventing member can be easily fixed to the housing by, for example, fitting. Therefore, it is possible to reduce the number of assembling steps during manufacturing.

According to the method of assembling the fuel supply device according to the fourth aspect of the present invention, the detachment preventing member is easily fixed to the housing by fixing the detachment preventing member to the housing by fitting or deformation of the detachment preventing member. Can be fixed.
Therefore, it is possible to further reduce the number of assembling steps during manufacturing.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIGS. 1 to 3 show a high-pressure fuel pump as a fuel supply device according to a first embodiment of the present invention. The high-pressure fuel pump 1 sucks low-pressure fuel pumped from a fuel tank (not shown) by a low-pressure fuel pump (not shown), and supplies the high-pressure fuel pressurized by the high-pressure fuel pump 1 to a distribution pipe (not shown). An injector as a fuel injection device is attached to the distribution pipe for each cylinder.

As shown in FIG. 1, a cylinder 12 as a cylinder portion is fixed in a housing 11 of the high-pressure fuel pump 1. The cylinder 12 supports the plunger 13 in a reciprocating manner, and slides on the plunger 13 on an inner peripheral surface 12a as a sliding surface. Head 13 of plunger 13
“a” is fixed to the tappet 14, and the plunger 13 reciprocates with the tappet 14. The outer peripheral wall of the plunger 13 is sealed by a rubber sealing member 16 outside the cylinder 12.

The bottomed cylindrical tappet 14 transmits the driving force of an engine (not shown) as an internal combustion engine to the plunger 13, and is capable of reciprocating in the housing 11. The tappet 14 is urged downward in FIG. 1 by a spring 15 via a spring seat 18,
The plunger 13 and the tappet 14 are reciprocated by the cam 100.

A plunger 13 is formed by the inner wall of the cylinder 12.
A fuel pressurizing chamber 17 is formed at an end of the fuel pressurizing chamber. The low-pressure fuel sucked into the fuel pressurizing chamber 17 by the lowering of the plunger 13 is pressurized by the raising of the plunger 13.

The solenoid valve 20 is mounted above the housing 11 by a retaining nut 27. Valve member 2
Numeral 1 is supported by the valve body 22 so as to be able to reciprocate, and is urged in the valve opening direction by a spring (not shown). A valve seat 23 is provided in the valve body 22, and a plurality of communication holes 22a are formed in the radial direction. Communication hole 22
a is a housing hole for housing the valve member 21 and the valve body 22;
And an annular fuel chamber 25 formed outside.
The annular fuel chamber 25 communicates with a fuel inlet (not shown) via a fuel intake passage (not shown), and a pressure regulator 5 (described later) via a fuel intake passage 31.
It communicates with the inside of 0. The movement of the valve member 21 in the valve opening direction is regulated by the seat plate 24. The sheet plate 24 is formed with a communication hole 24a penetrating the sheet plate 24.

A control current is supplied from a not-shown electronic control unit (ECU) to a solenoid (not shown) of the solenoid valve 20 via a connector 26, and the solenoid valve 20 is opened and closed by turning on and off the control current. When the solenoid valve 20 is opened when the power to the solenoid is turned off, the annular fuel chamber 25 is opened with the communication hole 22a, the opening between the valve member 21 and the valve seat 23, and the communication hole 24.
It communicates with the fuel pressurizing chamber 17 via a. When power is supplied to a solenoid (not shown), the valve member 21 is sucked against the urging force of the spring and seated on the valve seat 23. Thus, communication between the annular fuel chamber 25 and the fuel pressurizing chamber 17 is cut off.

As shown in FIG. 2, the pressure regulator 50 is mounted in a mounting hole 11a formed in the housing 11. The pressure regulator 50 includes a cylindrical holder 51, a valve body 52, a valve member 53, a spring 54, an adjusting pipe 55, and an O-ring 56. The outer diameter of the holder 51 is slightly smaller than the inner diameter of the mounting hole 11 a, and a flange portion 51 a having a larger diameter than the outer diameter of the holder 51 is provided on the outer peripheral portion of the holder 51. The outer diameter of the flange portion 51a is
1a is slightly smaller than the inner diameter of the inner peripheral wall of the step portion 11b formed on the inner peripheral wall. Contact part 5 provided on valve member 53
When the valve 3a moves away from the valve seat 52a formed in the valve body 52, the pressure regulator 50 opens and the contact portion 53
a is seated on the valve seat 52a.
0 closes the valve. When the pressure of the fuel introduced into the annular fuel chamber 25 shown in FIG. 1 becomes equal to or higher than a predetermined pressure, the pressure regulator 50 opens to return excess fuel to a fuel tank (not shown), and the fuel pressure in the annular fuel chamber 25 becomes a predetermined value. Prevent pressure over.

Groove 1 formed on the inner peripheral wall of step 11b
On the inner peripheral wall of 1c, a C-shaped retaining ring 5
7 is fixed and can contact the flange portion 51a. The C-shaped retaining ring 57 is made of, for example, carbon steel that can withstand a shear load of 4 kN, and has a C-shaped shape having both ends 58 and 59 as shown in FIG. Ends 58 and 5
9 is formed with holes 58a and 59a,
The C-shaped retaining ring 57 can be easily elastically deformed by hooking the tip of the special tool on the holes 58a and 59a.

As shown in FIG. 1, the delivery valve 41 is screwed to the housing 11. The delivery valve 41 is provided with a check valve 42, and the fuel discharge passage 32 connects the fuel pressurizing chamber 17 and the delivery valve 41. When the fuel pressure in the fuel pressurizing chamber 17 becomes equal to or higher than a predetermined pressure, the check valve 42 is opened, and high-pressure fuel is pumped to a distribution pipe (not shown).

Next, a method of assembling the high-pressure fuel pump 1 having the above configuration will be described. The cylinder 12 is mounted in the housing 11, and the solenoid valve 20 is mounted on the upper part of the housing 11. Plunger, spring 15, spring seat 18
Then, the tappet 14 is assembled into the housing 11 from below the housing 11.

The pressure regulator 50 is mounted in the mounting hole 11a of the housing 11, and the flange portion 51a of the holder 51 is brought into contact with the inner peripheral wall of the step portion 11b. By elastically deforming the C-shaped retaining ring 57, the C-shaped retaining ring 57 is fixed to the inner peripheral wall of the groove 11c. At this time,
The C-shaped retaining ring 57 can contact the flange portion 51a.

According to the above-mentioned assembling method and the assembling method, the pressure regulator 50 can be easily assembled to the housing 11. Here, for example, assuming that the outer diameter of the holder 51 is about 18 mm and the predetermined pressure of the fuel pressure introduced into the annular fuel chamber 25 is about 0.3 MPa, the holder 5 is moved in the direction in which the pressure regulator 50 comes out of the housing 11.
The load applied to 1 is about 76N. Therefore, a shear load of about 76N is applied to the C-shaped retaining ring 57. However, since the C-shaped retaining ring 57 can withstand a shear load of 4 kN,
The pressure regulator 50 can be prevented from falling out of the housing 11. That is, the C-shaped retaining ring 5
Reference numeral 7 denotes at least a predetermined pressure of the fuel pressure sucked by the high-pressure fuel pump 1 and prevents the pressure regulator 50 from falling out of the housing 11.

Next, the operation of the high-pressure fuel pump 1 will be described. (1) Suction stroke

During energization of the solenoid portion, the valve member 21
Is separated from the valve seat 23 and the solenoid valve 20 is opened. In this state, when the plunger 13 descends toward the bottom dead center, the volume of the fuel pressurizing chamber 17 increases, so that the communication hole 22a from the annular fuel chamber 25, the opening between the valve member 21 and the valve seat 23, and the communication hole 24a Then, the low-pressure fuel is sucked into the fuel pressurizing chamber 17.

(2) Pressurizing / Pressure Feeding Process After the plunger 13 reaches the bottom dead center, when the plunger 13 reaches a position corresponding to a desired fuel discharge amount in a stroke rising toward the top dead center, the solenoid unit Turn on the power supply to. When the valve member 21 is seated on the valve seat 23 against the urging force of the spring and the solenoid valve 20 is closed by the magnetic force generated by turning on the power supply to the solenoid, the annular fuel chamber 2 is closed.
The communication between 5 and the fuel pressurizing chamber 17 is cut off. When the plunger 13 further rises, the fuel in the fuel pressurizing chamber 17 is pressurized. When the fuel pressure in the fuel pressurizing chamber 17 becomes equal to or higher than a predetermined pressure, the check valve 42 of the delivery valve 41 is opened, and high-pressure fuel is discharged from the fuel discharge passage 32 and sent to the distribution pipe by pressure. The high-pressure fuel pressure-fed to the distribution pipe is injected from the injector at a predetermined timing.

Next, a comparative example in which a thread portion is provided on the outer peripheral surface of the holder 51 without using the C-shaped retaining ring 57 of the first embodiment will be described with reference to FIG. The same components as those in the first embodiment shown in FIG.

In the comparative example, as shown in FIG. 6, a screw portion 112 is provided on the outer peripheral surface of the holder 111 of the pressure regulator 110, and the pressure regulator 110 is attached to the housing 101 by the screw connection of the screw portion 112. It is assembled.

For this reason, in the comparative example, the screw portion 1 is formed on the outer peripheral surface of the holder 111 of the pressure regulator 110.
It takes a long time to process No. 12, and there is a possibility that the number of processing steps during manufacturing increases. Further, it takes time to perform the screw connection of the screw portion 112, which may increase the number of assembling steps during manufacturing.

On the other hand, in the first embodiment, a C-shaped retaining ring 57 is fixed to the inner peripheral wall of the groove 11b of the housing 11, and the C-shaped retaining ring 57 is fixed to the flange 51a of the holder 51 of the pressure regulator 50. Can be abutted. Therefore, the pressure regulator 50 can be prevented from falling out of the housing 11 at least at a predetermined pressure of the fuel pressure sucked by the high-pressure fuel pump 1. Therefore, since it is not necessary to provide a screw portion or the like in the holder 51 of the pressure regulator 50, the number of processing steps in manufacturing the pressure regulator 50 can be reduced.

Further, the C-shaped retaining ring 57 is fixed to the inner peripheral wall of the groove 11c of the housing 11 by elastic deformation. Therefore, the C-shaped retaining ring 57 can be easily fixed to the housing 11, and the number of assembly steps during manufacturing can be reduced.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
And FIG. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals. As shown in FIGS. 4 and 5, a step portion 61b is formed on the inner peripheral wall of the mounting hole 61a of the housing 61, and holes 61c and 61d communicating with the outer peripheral wall are formed on the inner peripheral wall of the step portion 61b. Have been. Pin-shaped pin members 62 and 63 are fitted in the holes 61c and 61d as slip-off preventing members. The pin members 62 and 63 have outer diameters slightly smaller than the inner diameters of the holes 61c and 61d, and have ends 62a and 63a.

In the second embodiment, the pin members 62 and 63 are fixed to the housing 61 by fitting the pin members 62 and 63 into the holes 61c and 61d, and the ends 62a and 63a It is possible to abut on the portion 51a. With such a configuration, the pressure regulator 50 can be prevented from falling out of the housing 11 at least at a predetermined pressure of the fuel pressure sucked by the high-pressure fuel pump 1.
Therefore, since it is not necessary to provide a screw portion or the like in the holder 51, the number of processing steps in manufacturing the pressure regulator 50 can be reduced.

Further, the pin members 62 and 63 are fitted into the holes 61c and 61d, so that the housing 1
Fixed to 1. Therefore, the pin members 62 and 63 can be easily fixed to the housing 11, and the number of assembly steps during manufacturing can be reduced.

In the above-described embodiments showing the embodiment of the present invention, the detachment preventing member is fixed to the housing, and the pressure regulator 50 is connected to the housing by at least a predetermined pressure of the fuel pressure sucked by the high-pressure fuel pump. It is possible to prevent slipping off. Therefore, since it is not necessary to provide a screw portion or the like in the holder 51,
It is possible to reduce the number of processing steps in manufacturing the pressure regulator 50.

Further, in the above embodiments, the detachment preventing member is fixed to the housing by swaging, fitting or deformation of the detachment preventing member. Therefore, the detachment preventing member can be easily fixed to the housing, and the number of assembling steps during manufacturing can be reduced.

In the above embodiments, the housing 11 and the cylinder 12 are formed as separate members. However, the housing and the cylinder may be formed integrally.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a high-pressure fuel pump according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a plan view showing a C-shaped retaining ring according to the first embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a high-pressure fuel pump according to a second embodiment of the present invention.

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is a longitudinal sectional view showing a high-pressure fuel pump according to a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High-pressure fuel pump (fuel supply device) 11 Housing 11a Mounting hole 11b Step 11c Groove 12 Cylinder (cylinder) 13 Plunger 14 Tappet 17 Fuel pressurization chamber 50 Pressure regulator 51 Holder 51a Flange 57 C-shaped retaining ring 61) Housing 61a Mounting hole 61b Step 61c, 61d Hole 62, 63 Pin member (prevention member) 62a, 63b End

Claims (4)

[Claims] 1. A fuel supply device for supplying high-pressure fuel to a fuel injection device of an internal combustion engine, comprising: a housing; a cylinder portion provided in the housing; A plunger that pressurizes the fuel sucked into the pressure chamber; a pressure regulator that is mounted on the housing and regulates a pressure of the fuel sucked into the fuel supply device to a predetermined pressure or less. A detachment preventing member for preventing the pressure regulator from being detached from the housing. 2. The fuel supply device according to claim 1, wherein the detachment prevention member has a C shape. 3. The fuel supply device according to claim 1, wherein the detachment prevention member has a pin shape. 4. A method of assembling the fuel supply device according to claim 1, wherein the pressure regulator is mounted on the housing, and the pressure regulator is fitted or deformed by the deformation of the prevention member. Fixing the prevention member to the housing.