JPH0732938Y2 - Fuel pump - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is provided in a fuel tank of an automobile, for example.
The present invention relates to a fuel pump which is preferably used for pressure-feeding and supplying the fuel in the fuel tank to an injection valve or the like.

[Conventional technology]

FIG. 3 shows a turbine type fuel pump as an example of a conventional small-sized fuel pump.

In the figure, 1 is a cylindrical casing body with both axial ends open, 2 is a pump housing fitted to one end side of the casing body 1, in the figure the lower end side, and the pump housing 2 is a suction port 3 An outer housing 2A having
It is composed of an inner housing 2B having a discharge port 4. A pump chamber 5 communicating with the suction port 3 and the discharge port 4 is formed in the pump housing 2, and a closed vane type turbine vane 6 as a pump rotor rotates in the pump chamber 5. It can be accommodated.

Reference numeral 7 denotes a cylindrical end cover with a lid fitted to the other end of the casing body 1. A cylindrical bush insertion portion 7A is provided at the center of the inner surface of the end cover 7, and a diameter of the bush insertion portion 7A. A pair of cylindrical brush holding portions 7B, 7B (one of which is not shown) located on both sides in the direction are formed.

Reference numeral 8 denotes a cylindrical discharge port formed on the outer surface of the end cover 7 so as to project. The discharge port 8 is composed of a small-diameter cylindrical portion 8A and a large-diameter cylindrical portion 8B. Zodiac 9
It has become. A discharge pipe 10 for supplying fuel to the fuel injection valve (not shown) side is attached to the discharge port 8.

Reference numeral 11 is a check valve for holding the residual pressure provided in the discharge port 8, and the check valve 11 is made of a resin material or the like, and has a valve body 11A that separates from and seats on the valve seat 9, and the valve body 11A. The valve shaft 11B protrudes, and the valve shaft 11B is slidably supported by a valve shaft holder 12 fitted in the discharge port 8. The check valve 11 is closed when the electric motor 16 described later is stopped to maintain the inside of the discharge pipe 10 at a predetermined residual pressure.

Reference numeral 13 is a rotary shaft that is installed between the pump housing 2 and the end cover 7 via bushes 14 and 15. One end side of the rotary shaft 13 is inserted into the turbine vane 6 in the pump housing 2 to integrally rotate. It is supposed to do. 16 is the rotary shaft
2 shows an electric motor provided in the casing body 1 for rotationally driving the rotor 13. The electric motor 16 is inserted into the rotating shaft 13 and rotates integrally with the rotor 16A and the flat commutator 16B.
And the brush holding part 7A of the end cover 7,
A pair of brushes 16C, 16C (one of which is not shown), which is constantly pressed against the commutator 16B by 17 and a rotor 16A.
And a stator 16D that is supported on the yoke 18 and is located on the outer peripheral side.

The fuel pump of the prior art is generally configured as described above. When the turbine vane 6 is rotated by the electric motor 16, the fuel sucked from the suction port 3 into the pump chamber 5 is pumped by the turbine vane 6 and discharged. It is discharged from the outlet 4 into the casing body 1. Then, the fuel pressure-fed into the casing body 1 pushes up the check valve 11 to open it, and is supplied from the discharge port 8 to the fuel injection valve and the pressure regulator (neither is shown) via the discharge pipe 10 or the like. The pressure inside the discharge pipe is adjusted by a pressure regulator.

Then, when the electric motor 16 stops and the fuel pressure in the casing body 1 falls below the set pressure of the pressure regulator, the check valve 11 causes the back pressure from the pressure regulator to cause the valve seat 9 to move.
By seating on and closing the valve, the inside of the discharge pipe 10 is maintained at a predetermined residual pressure.

[Problems to be solved by the device]

By the way, in the above-mentioned conventional technique, the discharge port 8
A valve seat 9 having a tapered diameter is coaxially provided midway in the axial direction, and the check valve 11 is seated on the valve seat 9. Therefore, the electric motor 16 is stopped and the check valve 11 is stopped.
Every time when is seated on the valve seat 9 due to the back pressure of the pressure regulator, foreign matter in the fuel flowing in the discharge port 8 from the discharge pipe 10 side to the casing body 1 side is concentrated on the valve seat 9.

Therefore, according to the conventional technique, the check valve 11 comes to sandwich the foreign matter between the check valve 11 and the valve seat 9 while the fuel pump is being used for a long period of time, and the sealing property of the check valve 11 is deteriorated, so that the discharge pipe 10 It is a cause of defective residual pressure.

Particularly, in a low-pressure specification vehicle in which the back pressure of the pressure regulator with respect to the check valve 11 is low, there is a problem that the sealability of the check valve is significantly deteriorated. In addition, since the valve body 11A of the check valve 11 is made of a resin material, it tends to be hard when the fuel temperature is low, and when the fuel temperature is low, foreign matter reduces the sealability of the check valve 11. .

The present invention has been made in view of the above-mentioned drawbacks of the prior art. By collecting the foreign matter in the fuel in the foreign matter reservoir in the discharge port, the foreign matter is prevented from adhering between the valve body and the valve seat. The present invention provides a fuel pump capable of improving the sealability of the residual pressure retention valve.

[Means for Solving the Problems]

A feature of the means of the present invention configured to solve the above-mentioned problems is that a foreign matter reservoir for collecting foreign matter mixed in fuel is provided in the axially inner portion of the discharge port. .

[Action]

With the above configuration, when the electric motor of the fuel pump is stopped, the back pressure of the pressure regulator causes foreign matter in the fuel that flows backward in the discharge pipe to flow axially in the discharge port and is collected in the foreign matter reservoir. It is possible to suppress the flow toward the space between the valve body and the valve seat of the residual pressure holding valve.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. It should be noted that the same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a first embodiment of the present invention.

In the figure, 21 is an end cover fitted to the other end of the casing body 1, and 22 is a pipe for discharging the fuel inside the casing body 1.
Discharge port for discharging to the side, the discharge port 22 is a hollow outer cylindrical portion 22A protruding to the outer surface of the end cover 21,
It is formed in the outer tubular portion 22A with a small-diameter inner tubular portion 22B that coaxially projects from the end cover 21. A valve seat 23 is formed at the tip of the inner cylinder portion 22B located in the middle of the discharge port 22, and the valve seat 23 has a valve shaft holder 12 fitted to the outer cylinder portion 22A. The supported check valve 11 is seated on and off.

Reference numeral 24 denotes an outer cylinder portion located at the axially inner portion of the discharge port 22.
22A shows a foreign matter reservoir formed between the inner cylindrical portion 22B and
The foreign matter reservoir 24 is formed in a bottomed annular shape having an inflow port 24A located on the outer peripheral side of the valve seat 23 and opening upward in the figure, and a bottom surface 24B located axially below the valve seat 23. Has been done.

The fuel pump of this embodiment has the above-mentioned configuration, and the basic operation of discharging the fuel sucked into the casing main body 1 to the discharge pipe 10 side through the discharge port 22 is significantly different from that of the prior art. There is no.

However, the present embodiment is characterized in that the foreign matter reservoir 24 for collecting the foreign matters A, A, ... In the fuel is provided in the discharge port 22, and this characteristic will be described below.

When the electric motor 16 stops and the fuel pressure in the casing body 1 drops, the discharge pipe is set by the pressure set by the pressure regulator.
The fuel pressure on the 10 side becomes high, and the back pressure acts on the check valve 11 so that the check valve 11 is seated on the valve seat 23. At this time, the foreign matter A mixed in the fuel in the discharge port 22 flows in the discharge port 22 in the axial direction in a substantially slate state, and the valve seat
From the inflow port 24A located on the outer peripheral side of 23, the foreign matter pool 24 flows into the bottom surface 24B side and is collected in the foreign matter pool 24. Since the foreign matter reservoir 24 is formed in the discharge port 22 along the axial direction, the foreign matter A enters between the check valve 11 and the valve seat 23 so as to wrap around and adheres to the valve seat 23. Can be prevented.

Thus, when the check valve 11 is closed, it is possible to prevent the foreign substance A from being sandwiched between the valve body 11A and the valve seat 23 so that the sealing performance is deteriorated, and the discharge pipe 10 side can be maintained at a predetermined residual pressure. .

Next, FIG. 2 shows a second embodiment of the present invention. In the drawing, 31 is an end cover, 32 is a discharge port formed on the outer surface of the end cover 31, and the discharge port 32 is connected to the discharge port main body 33 communicating with the casing main body 1 and a connection port portion 35 described later. It is composed of a pair of communication passages 37 and 38.

Here, the discharge port main body 33 is composed of a hollow cylindrical body 33A whose upper end side is open, and a tapered valve seat 34 is formed inside. The check valve 11 is provided in the discharge port body 33 via a valve shaft holder 40 described later.

Reference numeral 35 denotes a connection port portion to which the discharge pipe 10 is connected, and the connection port portion 35 is formed by a long bottomed cylindrical body arranged parallel to the side of the discharge port body 33.
A thick connecting portion 36 is integrally formed between the discharge port body 33 and the discharge port body 33. 37 and 38 are a pair of upper and lower communication passages formed in the connecting portion 36 for communicating the inside of the discharge port body 33 and the inside of the connection port portion 35, and one side opening of the lower communication passage 38.
38A is opened at a position above the valve seat 34, and the other side opening 38B is opened midway in the axial direction of the connection port portion 35,
The axially inner part of the connection port part 35 is a concave foreign material reservoir 39 having a bottom surface 39A.

Reference numeral 40 in the drawing denotes a valve shaft holder fitted in the discharge port body 33, and the valve shaft holder 40 is integrally formed with a lid plate 41 for closing the upper opening of the discharge port body 33. There is.

This embodiment has the above-described structure, and when the electric motor 16 is stopped and the back pressure of the pressure regulator acts on the fuel on the side of the discharge pipe 10, the foreign matter A in the fuel is connected to the connection port portion 35.
It flows straight in the axial direction inside and is collected in the foreign substance reservoir 39. Therefore, it is possible to reliably prevent the foreign matter A in the fuel from flowing from the connection port portion 35 into the discharge port body 33 through the communication passages 37 and 38 and being caught between the valve seat 34 and the check valve 11. Therefore, the discharge pipe 10 side can be maintained at a predetermined residual pressure as in the first embodiment.

In each of the above embodiments, the turbine type fuel pump has been described as an example, but the present invention is not limited to this, and can be applied to various fuel pumps such as a roller vane type and a trochoid type fuel pump.

[Effect of device]

The present invention is as described above in detail, and a foreign matter reservoir for collecting foreign matter in fuel is provided in the discharge port to prevent the foreign matter from being concentrated on the valve seat and sandwiched between the residual pressure holding valve and the foreign matter. Since it is configured to prevent it, it is based on the reduction of the residual pressure due to the poor sealing performance that is noticeable in low-pressure specification vehicles with low back pressure due to the pressure regulator, or the hardening of the valve element of the residual pressure retention valve at low fuel temperature. Problems such as poor sealability can be solved.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a turbine type fuel pump according to a first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a turbine type fuel pump according to a second embodiment of the present invention. FIG. 3 is a vertical cross-sectional view of a turbine fuel pump according to a conventional technique. 1 ... Casing body, 2 ... Pump housing, 10 ...
… Discharge pipe, 11 …… Check valve (residual pressure retention valve), 16 ……
Electric motor, 21,31 …… End cover, 22,32 …… Discharge pump, 23,34 …… Valve seat, 24,39 …… Foreign matter reservoir, A …… Foreign matter.

Claims (1)

[Scope of utility model registration request] 1. A casing main body having a pump housing provided on one side, an end cover provided on the other side of the casing main body, and a discharge provided on the end cover and connected to a discharge pipe. A port, a residual pressure holding valve for holding a residual pressure on the side of the discharge pipe by seating on and off a valve seat provided in the discharge port, and a pump in the pump housing provided in the casing body. A fuel pump comprising an electric motor that discharges the fuel sucked into the casing main body to the discharge pipe side through the discharge port by rotationally driving the rotor, in which the fuel inside the discharge port is located in the axial direction. A fuel pump having a foreign matter reservoir for collecting foreign matter mixed in the fuel pump.