JPH0551070B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an electric fuel pump used in an internal combustion engine for an automobile.

<Conventional technology> As a conventional fuel pump for an internal combustion engine, for example,
There is one shown in FIGS. 4 and 5 (see Japanese Utility Model Application Publication No. 17292/1983).

This is a roller vane type positive displacement pump, which includes a pump housing consisting of a pump head 1, a pump ring 2, and a pump plate 3, and a rotor that rotates around a fixed shaft 4 that is located inside the pump housing and passes through its eccentric position. 5, and a roller 7 housed in a plurality of grooves 6 provided at equal intervals on the outer peripheral surface of the rotor 5. 8 is a suction port, and 9 is a discharge port.

In addition, the armature 1 of the rotor 5 and the motor 10
1 through joints 12 and 13.

<Problems to be Solved by the Invention> Conventionally, in this type of roller vane fuel pump, pump operation has been affected due to variations in the position of the minimum clearance between the inner peripheral surface of the pump ring 2 and the outer peripheral surface of the rotor 5. There were cases where the noise increased and the discharge efficiency decreased.

For example, if the minimum clearance part is too far away from the suction port 8, each pump chamber 14 defined between two adjacent rollers 7, 7 will be relatively disconnected from the suction port 8 (suction stroke is completed). be late. For this reason, the volume of the pump chamber 14 decreases greatly until it communicates with the discharge port 9 and discharge starts, and the contact pressure between the roller 7 and the groove 6 increases, causing sliding noise (gurgling noise). increase

Conversely, if the minimum clearance portion is too close to the suction port 8, the volume of the pump chamber 14 increases between the end of the suction stroke and the start of the discharge stroke, causing the pressure inside the pump chamber 14 to become negative. Therefore, vapor is more likely to be generated, the sound of vapor being trapped (squeezing sound) is increased, and the discharge efficiency is considerably reduced.

The present invention has been made in view of these conventional problems, and provides a fuel fuel that allows the position adjustment of the minimum clearance between the pump chamber circumferential wall and the rotor outer circumferential wall to be performed easily and with high reliability. The purpose is to provide pumps.

<Means for Solving the Problems> For this reason, the present invention provides a protrusion on one of the overlapping end faces of the pump head and the pump ring, and a protrusion on the other end at least within a predetermined rotational angle range about the shaft. A radial groove that can be freely engaged is provided, and the mounting position of the pump head and pump ring around the shaft can be adjusted by adjusting the engagement position of these protrusions and the groove.

<Function> With this configuration, by adjusting the mounting position of the pump head and pump ring around the shaft, the minimum clearance between the pump ring inner circumferential surface and the rotor outer circumferential surface can be adjusted to the optimum position, and as a result,
Discharge efficiency can be improved as much as possible while reducing operating noise of the fuel pump as much as possible.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

In these figures, the same elements as in FIG. 3 are designated by the same reference numerals. In the figure, the end surface of the pump ring 2 that overlaps with the pump head 1 has one or two small protrusions 21 in a sawtooth shape near the minimum clearance between the inner circumferential surface of the pump ring 1 and the outer circumferential surface of the rotor 5. At the same time, the bolt through hole 22 formed in this portion is formed into an elongated hole that is long in the circumferential direction.

On the other hand, in a portion of the end face of the pump head 1 facing the protrusion 21, a radial groove 23 is provided which can freely engage with the protrusion 21 within a predetermined rotation angle range about the shaft 4.

With such a configuration, by adjusting the engagement position between the protrusion 21 and the groove 23 while gradually shifting it in the circumferential direction while the pump ring 2 is superimposed on the pump head 1, the outer peripheral surface of the rotor 5 and the pump ring 2 can be adjusted. The minimum clearance between the pump head 1, pump ring 2, and pump plate 3 can be easily fine-adjusted to the optimum position, and the pump head 1, pump ring 2, and pump plate 3 can be joined together and fastened together. There will be no misalignment when doing so.

Through such adjustment, it is possible to suppress as much as possible the occurrence of sliding noise caused by contact between the roller 7 and the groove 6, vapor biting noise, etc., and to maintain good discharge efficiency.

<Effects of the Invention> As explained above, according to the present invention, the minimum clearance between the outer circumferential surface of the rotor and the inner circumferential surface of the pump ring can be reduced by adjusting the engagement position between the protrusion and the groove provided on the pump ring and the pump head. The pump can be easily adjusted to the optimum position, thereby reducing pump operation noise as much as possible and maintaining good discharge efficiency.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the main structure of the present invention;
3 is a sectional view of a conventional fuel pump, and FIG. 4 is a sectional view taken along the - arrow in FIG. 3. 1...Pump head, 2...Pump ring, 3
...Pump plate, 4...Fixed shaft, 5...
...Rotor, 7...Roller, 8...Suction port, 9
...Discharge port, 21...Protrusion, 23...Groove.

Claims (1)

[Claims] 1 A pump head forming a fuel intake port,
A pump ring having a cylindrical pump chamber formed therein is overlaid and fastened between the pump plate in which the fuel discharge port is formed, and one end is inserted through the pump plate through the eccentric position of the pump chamber. A shaft fixed to the pump head, a hollow drive shaft that also penetrates the pump plate and is fitted into the shaft to freely rotate around the axis, and a circular drive shaft that is fixedly attached to the drive shaft with its central shaft part fixed in the pump chamber. In a roller vane fuel pump comprising a plate-shaped rotor and rollers disposed in a plurality of grooves formed on the outer peripheral surface of the rotor, a protrusion is provided on one end surface where the pump head and the pump ring overlap. and a radial groove that can be freely engaged within at least a predetermined rotational angle range about the protrusion and the shaft, and by adjusting the engagement position between the protrusion and the groove, the pump head and pump ring can be connected. A fuel pump characterized in that the fuel pump is configured to adjust the mounting position around the shaft.