JPH11257174A - Fuel pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve discharging efficiency of a pump and pressure controllability of pressure as well as to miniaturize a fuel pump device. SOLUTION: A fuel discharging path boss 20 is provided on an upper cover 4 of a pump housing 1 along the longitudinal axis X-X of the pump housing 1. A secondary side fuel discharging path 21B having a main valve seat 22 is provided on the fuel discharging path boss 20 while being opened toward the upper end 20A of the fuel discharging path boss 20. A main valve for opening and closing the main valve seat 22 is arranged on the secondary side fuel discharging path 91B. A relief passage 23D opened through a sub valve seat 25 toward the rear end 23A of the main valve and toward the bottom part 24A of a main valve part 24 on the tip is provided in the main valve, and a sub valve 26 to be backed up by a spring and for opening and closing the sub valve seat 25 is arranged in the relief passage 23D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for an internal combustion engine, and more particularly to a fuel supply system for a fuel injection system.
The present invention relates to a fuel pump device that is controlled by adjusting a discharge amount of a fuel pump.

[0002]

2. Description of the Related Art A conventional fuel pump device is disclosed in Japanese Unexamined Patent Publication No. 8-32.
No. 6616. According to this, a fuel supply device is described which detects a fuel pressure supplied to a delivery pipe with a pressure sensor and adjusts a fuel discharge amount of a fuel pump to maintain a supplied fuel pressure at a set value. I have. The fuel supply device includes a pump control unit that stops the fuel pump after the pressure has decreased to a predetermined value when the fuel injection is stopped, in order to prevent an excessive increase in the fuel supply pressure,
Moving speed control means for controlling the moving speed of the check valve in the closing direction when the fuel pump is stopped is provided.

[0003]

According to this conventional example,
When the fuel injection is stopped or the fuel pump is stopped, the pressure is constantly reduced irrespective of the fuel temperature, so that the followability of the fuel pressure during the next driving of the fuel pump is not good. Further, there is no means for reducing the fuel pressure when the pressure rises more than expected. Furthermore, it is difficult to set the amount of pressure decrease and the moving speed control means of the check valve. It is also conceivable to simply provide a relief valve to discharge fuel when the pressure rises.However, since the conventional relief valve has a structure in which fuel is simply discharged into the fuel tank, noise is generated by the discharged fuel. I will.

[0004] The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to prevent a rise in fuel pressure by a simple method without unnecessarily lowering the fuel pressure, and to prevent noise due to relief fuel. It is an object of the present invention to provide a fuel pump device that can perform the following.

[0005]

In order to achieve the above object, a fuel pump device according to the present invention has a pump unit in which a motor unit and a pump unit are housed and arranged in a pump housing, and is driven to rotate by the motor unit. In the fuel pump that sucks fuel from the fuel suction passage and discharges fuel from the fuel discharge passage through the inside of the pump housing, the fuel pump projects from the upper cover closing one end of the pump housing along the longitudinal axis of the pump housing. A fuel discharge passage boss is provided, and the fuel discharge passage boss is provided with a secondary fuel discharge passage having an opening toward an upper end of the fuel discharge passage boss and having a main valve seat facing the upper end; A main valve having a main valve portion that opens and closes a main valve seat at the tip thereof is movably arranged in the fuel discharge passage, and one end of the main valve is directed toward the rear end of the main valve inside the main valve. A relief passage is opened through the valve seat, and the other end is opened at the bottom of the main valve portion in an inner portion of the main valve seat. The relief passage is further backed up by a spring to open and close the sub-valve seat. When the fuel pump is driven, the main valve seat is opened at the main valve portion of the main valve, and the fuel in the pump housing is discharged toward the secondary side fuel discharge passage. When the fuel pressure applied to the sub-valve seat rises beyond a certain value at the time of stop, the sub-valve seat is opened by the sub-valve due to the pressure change, and the primary side fuel discharge passage is formed via the relief passage and the main valve seat. The first feature is that the pressure is released inward.

Further, the present invention is characterized in that a main valve portion and a sub-valve seat formed in the main valve are arranged to face each other on a longitudinal axis of a fuel discharge passage boss.

Further, in the present invention, it is preferable that the sub-valve seat is screwed into a relief passage opening at the rear end of the main valve, and the sub-valve seat is adjusted to be screwed from the upper end of the fuel discharge passage boss. 3.

[0008]

According to the first feature, the fuel discharge passage boss is formed by discharging from the upper cover in the longitudinal axis direction of the pump housing, and the fuel discharge passage boss is provided with the main valve seat.
A secondary fuel discharge passage is provided, and a main valve having a main valve portion for opening and closing a main valve seat and a relief passage having a sub-valve for opening and closing a sub-valve seat is arranged in the secondary fuel discharge passage. Therefore, an increase in fuel pressure can be prevented by a very simple method, and the structure of the fuel pump device does not increase in size only by improving the check valve portion. Further, since the relief fuel is discharged into the fuel pump, generation of noise due to the relief fuel can be prevented.

According to a second feature, the second valve including the main valve seat is provided.
The relief passage including the secondary fuel discharge passage and the auxiliary valve seat can be arranged in the fuel discharge passage boss without increasing the size of the discharge side end of the fuel pump device.

According to the third feature, the spring force of the spring pressing the sub-valve can be adjusted in the assembled state of the fuel pump device, whereby the fuel pressure can be set and adjusted very accurately.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel pump device according to the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a fuel pump device according to the present invention. FIG. 2 is a detailed view of a portion A in FIG. FIG. 3 is an upper plan view of FIG. 2. FIG. 4 is a cross-sectional view taken along line BB of FIG.

Reference numeral 1 denotes a cylindrical pump housing whose upper and lower ends are open. The lower opening is closed by a lower cover 2, and the upper opening is closed by a support cover 3 and an upper cover 4. The pump unit P and the motor unit M are arranged in the pump housing 1 closed as described above. The pump section P has an impeller 7 disposed in a pump chamber 6 formed by the lower cover 2 and the pump cover 5 in contact with the lower cover 2.
The pump chamber 6 and the inside of the pump housing 1 are connected via a fuel discharge path 9 provided in the pump cover 5. The motor unit M includes an armature core 11 arranged on the outer periphery of the shaft 10, a commutator 12 electrically connected to the armature core 11, a brush (not shown) connected to the commutator 12, and an armature. It is constituted by permanent magnets 13 arranged on the outer periphery of the iron core 11 with a gap. Both ends of the shaft 10 are rotatably supported by a bearing 14 of the support cover 3 and a bearing 14 of the pump cover 5.
The impeller 7 is inserted and disposed at the lower end of the shaft 0, and the rotation of the shaft 10 is transmitted to the impeller 7 in synchronization with the impeller. In addition, 15
This terminal is electrically connected to the brush and connected to an external power supply.

The above is the known pump unit P and motor unit M. When the motor unit M is rotated by supplying power to the motor unit M from the terminal 15, this rotation is transmitted to the impeller 7 via the shaft 10 and 7, the fuel in a fuel source (not shown) is sucked into the pump chamber 6 from the fuel suction passage 8, the fuel is pressurized in the pump chamber 6, and the pressurized fuel is supplied to the fuel discharge passage 9. It is further discharged into the pump housing 1.

Here, the fuel pump device according to the present invention comprises:
In order to achieve the above object, the following configuration was adopted. Reference numeral 20 denotes a fuel discharge passage boss provided on the upper cover 4 that closes one end of the pump housing 1 and protrudes upward along the longitudinal axis XX of the pump housing 1 on the upper cover 4. And has an upper end 20A above it. The fuel discharge passage 21 connects the inside of the pump housing 1 and the upper end 20A of the fuel discharge passage boss 20. The fuel discharge passage 21 is substantially linear along the longitudinal axis XX of the pump housing 1. It is formed in a shape. That is, the lower part of the fuel discharge passage 21 is opened inside the pump housing 1, and the upper part thereof is opened at the upper end 20 </ b> A of the fuel discharge passage boss 20. More specifically, the lower part of the fuel discharge path 21 is mainly the primary side fuel discharge path 21 formed in the support cover 3.
A is opened inside the pump housing 1 through A, and the upper part thereof is the main valve seat 2 facing the upper end 20A of the fuel discharge passage boss 20.
2 is opened at the upper end 20 </ b> A of the fuel discharge passage boss 20 via a secondary fuel discharge passage 21 </ b> B provided with a fuel injection passage 2. Pump housing 1
The fuel in the inside is the primary side fuel discharge passage 21A, the main valve seats 22,
The fuel is discharged toward the upper end 20A of the fuel discharge passage boss 20 via the secondary fuel discharge passage 21B.
1A, the main valve seat 22, and the secondary side fuel discharge passage 21B are formed substantially linearly along the longitudinal axis XX of the pump housing 1.

In the secondary side fuel discharge passage 21B having the main valve seat 22, the main valve seat 22 is made movable vertically.
Is disposed. The main valve 23 has the following configuration. The outer shape of the main valve 23 has a cylindrical shape so as to be in sliding contact with the secondary fuel discharge passage 21B, and has a notch 23C formed from the rear end 23A toward the front end 23B. In this example, two opposing notches 23C were formed. The notch 23C is understood from FIG. 4, and is formed by the notch 23C.
Is secured. Also, at the tip 23B of the main valve 23,
A main valve portion 24 for opening and closing the main valve seat 22 is formed integrally.

A relief passage 23D is formed inside the main valve 23. One end of the relief passage 23D is open to the rear end 23A of the main valve 23, and the other end is connected to the main valve seat 22.
It is located at the inner portion E and opens at the bottom 24A of the main valve portion 24. The auxiliary valve seat 25 is screwed and disposed on the rear end 23A side of the relief passage 23D. This sub valve seat 2
5 has an operation groove 25A such as a minus groove. That is, the upper part of the relief passage 23D formed in the main valve 23 opens to the rear end 23A of the main valve 23 through the sub-valve seat 25, and the lower part of the relief passage 23D is the bottom 24 of the main valve part 24.
Open to A According to the above, the main valve portion 24 and the sub-valve seat 25 formed in the main valve 23 are arranged to face each other on the longitudinal axis YY of the fuel discharge passage boss 20. A sub-valve 26 is movably disposed in the relief passage 23D. The sub-valve 26 is backed up by a spring 27 to close and hold the sub-valve seat 25. In addition, 23E is
A notch recess formed in the rear end 23A of the main valve 23.

The main valve 23 is assembled as follows. From the rear end 23A of the main valve 23, a spring 27 and an auxiliary valve 26 are arranged in a relief passage 23D,
Next, the relief passage 2 that opens to the rear end 23A of the main valve 23
The sub-valve seat 25 is screwed into 3D. According to the above, the spring 27, the auxiliary valve 26, and the auxiliary valve seat 2 are provided in the relief passage 23D.
5 is disposed, and the sub-valve 26 is pressed by the spring force of the spring 27 to close and hold the sub-valve seat 25.

The main valve 23 assembled as described above is disposed from the upper end 20A of the fuel discharge passage boss 20 into the secondary fuel discharge passage boss 21B, and then opens to the upper end 20A of the fuel discharge passage boss 20. Secondary side fuel discharge path 21B
The pressing member 28 is press-fitted. A through hole 28A is formed in the locking member 28 so that the operation groove 25A of the auxiliary valve seat 25 can be rotated from the upper end 20A of the fuel discharge passage boss 20. In this state, the rear end 23A of the main valve 23
A gap G that allows the movement of the main valve 23 is formed between the main valve 23 and the lower surface of the locking member 28.

The fuel pump device of the present invention having the above-described structure operates as follows. First, when the motor unit M of the fuel pump device is stopped when no current is supplied, the pump unit P does not act as a pump, and the main valve 23 is connected to the main valve seat 2.
2 is closed. This state is shown in FIGS. According to the above description, the fuel is already supplied and remains in the fuel pipe (not shown) that connects the secondary fuel discharge path 21B and the fuel supply system such as the fuel distribution pipe and the carburetor arranged downstream thereof. The fuel does not flow back into the fuel pump device and the fuel in the fuel pipe does not become empty. On the other hand, the sub-valve 26 is pressed by the spring 27 to close and hold the sub-valve seat 25, so that the fuel in the fuel pipe including the secondary-side fuel discharge passage 21B passes through the relief passage 23D and the primary valve seat 22 through the primary valve. It is not discharged into the side fuel discharge passage 21A. Therefore, when the fuel pump device is driven again, the fuel can be immediately supplied to the fuel supply system.

Here, when the fuel pump device is stopped, if the fuel pipe is heated by the heat of the engine or the like, the fuel in the fuel pipe expands and the fuel pressure rises greatly, and this pressure is Relief passage 23D opening near upper end 20A of road boss 20 (specifically, sub-valve seat 25)
Act on. Here, in the fuel pump device according to the present invention, the greatly increased fuel pressure is applied to the relief passage 2.
When acting on one end of the 3D, this pressure acts on the sub-valve 26 via the sub-valve seat 25, and at this time, the sub-valve 26 opens the sub-valve seat 25 against the spring force of the spring 27. According to the above description, the greatly increased fuel pressure is introduced into the relief passage 23D via the sub-valve seat 25, and is released from the bottom 24A of the main valve portion 24 into the primary fuel discharge passage 21A and the pump housing 1. Thus, the fuel pressure in the fuel pipe including the secondary fuel discharge passage 21B can be maintained at a desired pressure again. This state is shown in FIG.

Here, in the above, the relief passage 23
The relief passage 23 </ b> D including the sub valve seat 25 of D is formed along the longitudinal axis Y-Y of the fuel discharge passage boss 20.
And opening the upper part of the relief passage 23 to the rear end 23A of the main valve 23. Thereby, the fuel pressure in the fuel pipe can act on the sub-valve 26 in the vertical direction S, so that the operation of the sub-valve 26 can be promptly performed in response to the increase in the fuel pressure, and the fuel pressure can be accurately adjusted. Control and its responsiveness can be accelerated. Further, since the fuel whose pressure has been increased is released into the pump housing 1, noise generation due to this fuel can be effectively prevented.

Next, when a current is supplied to the motor section M of the fuel pump apparatus to drive the pump section P, the fuel pressurized by the pump section P is discharged into the pump housing 1 and the fuel is supplied to the primary side. Acting on the main valve 25 via the fuel discharge passage 21A and the main valve seat 22, the main valve 23 is moved upward to open the main valve seat 22, and the fuel discharged into the pump housing 1 is discharged to the secondary side. The fuel flows into the fuel discharge passage 21B, and is then supplied from the upper end 20A of the fuel discharge passage boss 20 to a fuel supply system via a fuel pipe (not shown).

Here, paying attention to the fuel discharge passage 21 in the fuel pump device, in particular, the secondary fuel discharge passage 21
B and the main valve 23 including the relief passage 23D are formed along the longitudinal axis YY of the fuel discharge passage boss 20 and are formed in the fuel discharge passage boss 20, so that the discharge-side end of the fuel pump device is provided. Can be reduced in size, and the degree of freedom in mounting on an engine can be increased.

When attention is paid to the fuel discharge passage 21 in the fuel pump device, the primary fuel discharge passage 21A, the main valve seat 22, and the secondary fuel discharge passage 21B are arranged along the longitudinal axis XX of the pump housing 1. Therefore, the fuel can be supplied to the fuel pipe in a substantially straight line without significantly bending the flow of the fuel. According to the above, at least the fuel flow in the fuel pump device can be approximated to a linear flow, which is effective in that the fuel flow can be smoothed and the discharge efficiency of the pump is increased.

The main valve portion 24 formed on the main valve 23 has
Disposed on the longitudinal axis Y-Y of the fuel discharge passage boss 20,
The sub-valve seat 25 disposed on the main valve 23 also has the longitudinal axis Y
-Y and their main valve portion 24, sub-valve seat 2
5, the secondary fuel discharge passage 21B having the main valve seat 22 is connected to the primary fuel discharge passage 21A.
The secondary-side fuel discharge path 21B and the sub-valve seat 25 having the main valve seat 22
Can be easily arranged in the fuel discharge passage boss 20.

Here, the opening characteristic of the sub-valve 26 with respect to the sub-valve seat 25 is appropriately selected depending on the fuel supply system to be used or the engine to be mounted. When the assembly of the fuel pump device is completed, the auxiliary valve seat 25 is screwed from the upper end 20A of the fuel discharge passage boss 20 through the through hole 28A of the locking member 28,
Thereby, the spring force of the spring 27 with respect to the sub-valve 26 can be variably adjusted. That is, if the set length of the spring 27 is set short by tightening the sub-valve seat 25, the control pressure can be increased. On the other hand, if the set length of the spring 27 is set long by squeezing the sub-valve seat 25, , The control pressure can be lowered.

Further, the spring force of the spring 27 has an error during the manufacture of the spring 27. The error is corrected by screwing the sub-valve seat 25 to accurately adjust the spring force to the sub-valve 26. In this manner, accurate and highly uniform fuel pressure control can be performed. Since the adjustment of the spring force can be performed in a state in which the fuel pump device is completely assembled, the adjustment can be performed in an actual fuel discharge state, and the accuracy of the control pressure can be further improved.

[0028]

According to the fuel pump device of the present invention, the following special effects can be obtained. A fuel discharge passage boss 20 is provided that protrudes from the upper cover 4 that closes one end of the pump housing 1 along the longitudinal axis XX of the pump housing 1, and the fuel discharge passage boss 20 is provided on the fuel discharge passage boss 20. A secondary side fuel discharge passage 21B having a main valve seat 22 facing the upper end and opening toward the upper end 20A of the
A main valve 23 having a main valve portion 24 for opening and closing the main valve seat 22 at the tip thereof is movably disposed in the secondary fuel discharge passage 21B, and one end of the main valve 23 is provided inside the main valve. Rear end 2
3A, a relief passage 23D is opened through the sub-valve seat 25, and the other end is opened at the bottom 24A of the main valve portion 24 inside the main valve seat 22. Backed up at 27 and auxiliary valve seat 25
First, the discharge-side end of the fuel pump device can be miniaturized, and the degree of freedom of mounting on the engine can be increased. A terminal is generally arranged at the end on the discharge side, and a coupler housing is formed on the outer periphery of the terminal. This is convenient without interfering with the provision of the coupler housing. Second, it is preferable in improving the discharge efficiency of the fuel pump device. This is because the secondary-side fuel discharge passage is formed in a straight line, and the fuel flow from the pump housing to the fuel pipe can be flowed substantially linearly without largely bending the fuel flow, so that the fuel flow is not hindered. Third, the responsiveness of the sub-valve having the relief valve function for maintaining the fuel pressure in the fuel pipe at a constant pressure can be improved. Fourth, by releasing the increased fuel pressure into the pump housing 1, noise due to this fuel can be effectively prevented.

Further, the main valve portion 24 and the sub-valve seat 25 formed in the main valve 23 are opposed to each other on the longitudinal axis Y-Y of the fuel discharge passage boss 20. It is convenient to arrange the relief passage including the secondary fuel discharge passage and the sub-valve seat in the fuel discharge passage boss, and the discharge end of the fuel pump device can be reduced in size.

According to the fact that the sub-valve seat 25 is screwed into the relief passage 23D opening to the rear end 23A of the main valve 23, and the sub-valve seat is adjusted by screwing from the upper end 20A of the fuel discharge passage boss 20, the fuel When the assembly of the pump device is completed, the setting of the fuel pressure in the fuel piping system can be arbitrarily changed, so that a highly versatile fuel pump device can be provided. Furthermore, the spring force of the spring pressing the sub-valve can be provided. Thus, the manufacturing error can be adjusted by this, so that pressure control with high accuracy can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a fuel pump device according to the present invention.

FIG. 2 is a detailed view of a portion A in FIG.

FIG. 3 is an upper plan view of the fuel discharge passage boss of FIG. 2;

FIG. 4 is a transverse sectional view taken along line BB of FIG. 2;

FIG. 5 is a longitudinal sectional view of a main part showing a state in which a sub-valve opens a sub-valve seat when the fuel pump device is stopped.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump housing 4 Upper cover 20 Fuel discharge passage boss 20A Upper end of fuel discharge passage boss 21B Secondary fuel discharge passage 22 Main valve seat 23 Main valve 24 Main valve part 25 Sub-valve seat 26 Sub-valve 27 Spring

Claims (3)

[Claims] 1. A motor housing and a pump unit are housed and arranged in a pump housing, and a pump unit rotatably driven by the motor unit draws fuel from a fuel suction passage and from a fuel discharge passage through the pump housing. In a fuel pump for discharging fuel, a pump housing 1
A fuel discharge passage boss 20 protruding from the upper cover 4 closing one end of the pump housing 1 along the longitudinal axis XX of the pump housing 1 is provided. The upper end 20A of the fuel discharge passage boss 20 is provided on the fuel discharge passage boss 20. And a main valve that opens and closes the main valve seat 22 at the tip of the secondary fuel discharge passage 21B in the secondary fuel discharge passage 21B. A main valve 23 having a portion 24 is movably disposed, and one end of the main valve 23 is provided inside the main valve 23.
3 is opened through the sub-valve seat 25 toward the rear end 23A, and the other end is the bottom 24A of the main valve portion 24 inside the main valve seat 22.
A relief valve 23D that opens and closes the relief valve 23, and a relief valve 23D that opens and closes a relief valve seat 25 that is backed up by a spring 27 is disposed in the relief passage 23D. 24, the main valve seat 22 is opened, and the fuel in the pump housing 1 is discharged to the secondary side fuel discharge passage 2.
When the fuel pressure applied to the sub-valve seat 25 rises beyond a certain value when the fuel pump is stopped, the sub-valve 26 is opened by the sub-valve 26 due to the pressure change, A fuel pump device characterized in that pressure is released toward the inside of a primary fuel discharge passage (21A) through a relief passage (23D) and a main valve seat (22). 2. A main valve portion 24 and a sub-valve seat 25 formed on the main valve 23 are connected to a longitudinal axis YY of a fuel discharge passage boss 20.
2. The fuel pump device according to claim 1, wherein the fuel pump device is disposed to face upward. 3. The sub-valve seat 25 is connected to a rear end 23A of the main valve 23.
The fuel pump device according to claim 1, wherein the auxiliary valve seat is screw-adjusted from an upper end (20A) of the fuel discharge passage boss (20).