JPH0115918Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is used in automobiles, etc., and is used in in-tank fuel pumps installed in fuel tanks, in particular to remove air bubbles generated by the rotation of the impeller. It is related to.

[Conventional technology]

4 and 5 show a conventional in-tank fuel pump. 1 is a main body forming the outer shell of the pump, 2 is a cylindrical yoke, 3 is a cover-out fitted to one side of this yoke 2, and 3A is a part that protrudes outside of this cover-out 3 to drain the fuel in the fuel chamber 4. A discharge cylinder 5 for discharging to the outside of the main body 1, a bracket 5 fitted onto the yoke 2 and positioned by the stepped portion 2A, 5A a first through hole provided in the bracket 5 and into which the commutator 14 is inserted; 5B; 6 is a second through hole for sending the fuel sent by the impeller 16 to the fuel chamber 4; 6 is a pump cover fitted into the bracket 5 and fitted onto the yoke 2; 6A is the outside of this pump cover 6; 8 is a first metal bearing fitted into a recess in the cover out 3 and fixed by a metal retainer 9; 10 is a first metal bearing fitted into a recess in the pump cover 6; A metal bearing 2, 11 is a motor, and both ends are connected to a first metal bearing 8 and a second metal bearing 1, respectively.
A main shaft 12 supported on the main shaft 12, an armature 13 and a commutator 14 fitted on the main shaft 12, and
3 and a magnet 15 fixed inside the yoke 2. 14A are a plurality of protrusions projecting from the commutator 14 substantially parallel to the main axis 12. The impeller 16 is the main shaft 1
2 and the protrusion 14A of the commutator 14,
The outer periphery is shaped like a feather. 17 is commutator 1
4 is a brush device that supplies power; 18 is a terminal that is connected to the brush device 17 and supplies power from the outside; 19 is a fixing member that is made of an elastic member and is formed into a substantially U-shape and fixes the magnet 15 within the yoke 2; It is.

Next, the operation configured in this way will be explained.

First, when external power is supplied to the brush device 17 via the terminal 18, the motor 1 is activated by electromagnetic action to rotate the armature 13. Therefore, the impeller 16 fitted into the main shaft 12 is rotated by the rotational force transmitted through the protrusion 14A of the commutator 14. As a result, the fuel is transferred to the suction cylinder 6A.
The fuel flows into the pump chamber 7, is transferred by the blade-like unevenness formed on the outer periphery of the impeller 16, and is pumped into the fuel chamber 4 via the first through hole 5A. When the fuel chamber 4 is filled with the fuel, the fuel is pressurized by the pressure of the fuel pumped from the impeller 16, and is pumped from the discharge tube 3A to a carburetor of an automobile (not shown), for example.

[Problem that the invention attempts to solve]

In the in-tank fuel pump as described above, air bubbles are generated when the impeller 16 rotates and the blade-like irregularities formed on the outer periphery agitate the fuel. Since these bubbles float upward in FIG. 4, they are pumped together with fuel from the discharge tube 3A to, for example, a carburetor of an automobile. This lowers the combustion pressure of fuel in the engine, impairing performance. In some cases, there were problems such as the engine stopping.

This idea was made to eliminate these problems, and even if bubbles are generated, the purpose is to release the bubbles outside of the main body 1 so that the equipment in the next process of the fuel pump can operate normally. This is what I did. In addition to the above objects, the embodiments of this invention also aim to provide an in-tank fuel pump that can effectively position the magnet.

[Means to solve the problem]

In the in-tank fuel pump according to this invention, an injection cylinder is provided at a position where fuel is injected from the pump chamber into the fuel chamber, and a discharge cylinder is provided at a position where fuel is discharged from the fuel chamber to the outside of the main body. In addition to ensuring that the fuel chambers do not face each other,
A release hole is provided to release air bubbles to the outside of the main body. Further, in the embodiment of this invention, the inlet of the discharge cylinder is arranged lower than the outlet of the injection cylinder, and the discharge cylinder is further provided to extend into the fuel chamber.

[Effect]

In this invention, even when the impeller rotates and bubbles are generated in the pump chamber, the bubbles float up through the fuel in the fuel chamber from the injection tube and are smoothly discharged from the discharge hole to the outside of the main body.

Furthermore, in the embodiment of this invention, the inlet of the discharge tube is located lower than the outlet of the injection tube, so that air bubbles entering the fuel chamber from the injection tube are suppressed as much as possible from entering the discharge tube. Furthermore, since the discharge tube extends into the fuel chamber and contacts the circumferential end surface of the magnet, the magnet can be effectively positioned by the discharge tube.

〔Example〕

1, 2 and 3 show an embodiment of this invention.

In FIG. 1, 20 is a discharge tube extending from the cover-out 3 into the fuel chamber 4, 21 is an injection tube formed continuously in the second through hole 5B of the bracket 5, and 22 is a discharge tube extending from the cover-out 3 into the fuel chamber 4. This is a discharge hole that is provided at the upper part of the fuel chamber and discharges air bubbles in the fuel chamber 4 to the outside. The inlet of the discharge tube 20 and the outlet of the injection tube 21 are arranged at positions that do not face each other, and the inlet of the discharge tube 20 is formed below the outlet of the injection tube 21. There is. The discharge tube 20 extends inside the main body 1. For this reason, as shown in FIG.
Both side surfaces of magnet 15 are connected to circumferential end surfaces 15a of magnet 15.
The magnet 15 is fixed in cooperation with the U-shaped fixing member 19.

In the in-tank fuel pump configured as described above, when the impeller 16 rotates and air bubbles are generated in the pump chamber 7, these air bubbles flow from the injection cylinder 21 into the fuel chamber 4, as shown in FIG. Float and surface. However, the outlet of the injection cylinder 21 is
Since it does not face the inlet of 0, it rises and is discharged from the discharge hole 22 of the cover out 3 to the outside of the main body 1.

Furthermore, when the bubbles are injected into the fuel chamber 4 together with the fuel from the injection tube 21, they are located above the lower surface of the discharge tube 21 in FIG.
from the discharge hole 22 to the main body 1.
released outside. At this time, a part of the fuel leaks out from the discharge hole 22, that is, into the fuel tank, together with the bubbles, but the amount is very small, so there is little loss in pump work.

Further, since the discharge tube 20 extends inside the main body 1, the discharge tube 20 comes into contact with the circumferential end surface of the magnet 15 of the motor as shown in FIG. 2, and the magnet 15 can be positioned.

[Effect of idea]

As explained above, this idea has the outlet of the injection tube in the part where fuel is injected into the fuel chamber and the inlet of the discharge cylinder in the part where fuel is discharged not facing each other, and the upper part of the fuel chamber is Since the bubble discharge hole is provided, the bubbles generated by the rotation of the impeller are smoothly discharged to the outside from the discharge hole, so that the bubbles are not forced into the discharge tube and degrade the performance of the equipment in the next process. There is no.

Furthermore, in the embodiment of this invention, the inlet of the discharge tube is located below the outlet of the injection tube, which effectively prevents air bubbles entering the fuel chamber from the injection tube from being sent into the discharge tube. As a result, air bubbles are reliably released from the main body through the release holes.

Furthermore, in the embodiment of this invention, the above-mentioned discharge cylinder is extended into the fuel chamber, and both sides of the discharge cylinder are brought into contact with the circumferential end surface of the motor's magnet, thereby eliminating displacement in the circumferential direction of the magnet and positioning it. This has various effects, such as improving the performance of the in-tank fuel pump by preventing position changes.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of this invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is a partially cutaway perspective view showing the same embodiment. FIG. 4 is a longitudinal sectional view showing a conventional example, and FIG. 5 is a sectional view taken along the - direction in FIG. 4. 4... Fuel chamber, 7... Pump chamber, 11... Motor, 15... Magnet, 16... Impeller, 2
0...Discharge cylinder, 21...Injection cylinder, 22...Discharge hole. Note that the same reference numerals in the figures indicate the same parts.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In an in-tank fuel pump that rotates an impeller in the pump chamber by a motor disposed in the fuel chamber in the main body and discharges fuel, the fuel from the impeller in the pump chamber is an injection tube for injecting fuel into the fuel chamber, a discharge tube for discharging fuel from the fuel chamber and having an inlet located at a position not facing the outlet of the injection tube, and a discharge tube for discharging fuel from the fuel chamber; An in-tank fuel pump comprising: a discharge hole for discharging fuel to the outside of the main body. (2) The in-tank fuel pump according to claim 1, wherein the inlet of the discharge cylinder is located lower than the outlet of the injection cylinder. (3) The in-tank fuel pump according to claim 1 or 2, wherein the discharge cylinder extends into the fuel chamber and comes into contact with the circumferential end surface of the magnet of the motor.