JPH08200175A - Filter for fuel pump - Google Patents

Abstract

PURPOSE: To provide a filter for a fuel pump which is constituted to reduce the generation of impeller noise in a wide frequency area. CONSTITUTION: A filter 11 for a fuel pump has one end forming a filter part 31 and the other end part forming a pump coupling outlet 14 connected to a pump suction port. The filter part 31 comprises a filter frame 32 and a filter mesh 35, and a suction port member 25 is arranged therein. A partition plate having a communication port communicated in the direction of the thickness of a plate is arranged in a suction pipe part 13 and a suction port member 25. A first damper chamber 41 is formed on the suction pipe 13 side partitioned by the partition plate and a second damper chamber 43 is formed on the suction port member 25 side of the partition plate. Since a plurality of damper chambers 41 and 43 having a cross-sectional area greater than the sectional area of an ordinary fuel passage are arranged in series, this constitution relaxes the primary sound pressure generated from the fuel pump side, and reduces the generation of noise in a wide frequency area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter mounted on the suction port side of a fuel pump.

[0002]

2. Description of the Related Art As a conventional technique, the Japanese Utility Model Laid-Open No. 60-371
As disclosed in Japanese Patent No. 76, the lower portion of the fuel pump installed in the fuel tank is brought close to the bottom surface of the fuel tank,
A suction pipe extending horizontally from the lower part of the fuel tank is attached, and a diffusion portion is provided on the base side of the suction pipe.
It is known that a contraction portion is formed on the suction side of the diffusion portion. In this structure, a diffusion portion is formed in which the cross-sectional area of the suction pipe is at least 10 times larger than that of the fuel inlet of the fuel pump, and the noise of the fuel pump is reduced by the enlarged area of the suction pipe.

[0003]

However, this conventional fuel pump has a noise reducing effect at a specific frequency, but the noise reducing effect is small depending on the number of revolutions of the fuel pump or the type of the fuel pump. Or, conversely, noise may be amplified. The purpose of the present invention is to
It is to provide a filter for a fuel pump that reduces noise in a wide frequency range.

[0004]

A fuel pump filter according to claim 1 of the present invention for achieving the above object is a filter mounted on a pump suction port side of a fuel pump, wherein A configuration is adopted in which a first damper chamber and a second damper chamber whose passage cross-sectional areas are expanded in two stages are provided in the middle of a communication passage formed between the pump suction port and the pump.

A fuel pump filter according to claim 2 is
The structure according to claim 1, characterized in that the first damper chamber and the second damper chamber are integrally molded by a component forming a filter. In the fuel pump filter according to a third aspect of the present invention, the first damper chamber and the second damper chamber are partitioned by a partition plate having a communication port.

A filter for a fuel pump according to claim 4 is
The first damper chamber and the second damper chamber have different volumes. A filter for a fuel pump according to claim 5 is a filter attached to a pump suction port side of a fuel pump, and has three or more stages in the middle of a communication passage formed between a filtering portion of the filter and the pump suction port. It is characterized in that three or more damper chambers having an enlarged passage cross-sectional area are provided.

A fuel pump filter according to claim 6 is
One end is connected to the pump suction port, the other end is a suction pipe connected to the filter unit, and a suction port member housed inside the filter unit, having a suction port at one end, A partition plate that is provided between the suction pipe and the suction port member and has a communication hole that communicates in the plate thickness direction; and a first side on the suction pipe side that is partitioned by the partition plate.
A damper chamber is provided, and a second damper chamber is provided on the side of the suction port member of the partition plate.

[0008]

According to the fuel pump filter of the present invention, a plurality of damper chambers having a larger cross-sectional area than the normal fuel passage cross-sectional area are provided in series in the filter portion attached to the suction port side of the fuel pump. Therefore, it is possible to reduce the sound pressure generated from the fuel pump side and reduce the noise in a wide frequency range.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the present invention applied to an in-tank type fuel pump for pumping fuel to an internal combustion engine for a vehicle. As shown in FIG. 1, the fuel pump 1 is a small pump having an outer diameter of 38 mm, which includes a pump unit 2, a DC motor unit 3, and a discharge unit 4. Since this pump has a small outer diameter and a small discharge amount per one rotation, the number of rotations is increased to discharge the required discharge amount.

The pump unit 2 sucks fuel into the pump chamber from the pump suction port 6 by the rotation of the impeller having 47 blades which is rotated by receiving the driving force of the DC motor unit 3, and the impeller (not shown) causes the pump chamber to move to the pump housing. It is discharged from the pump discharge port 8 through the inside of 7. DC motor unit 3
Rotates the armature by the drive current supplied through the terminal of the electrical connector 9 and rotates the impeller fixed to the end of the shaft fixing the armature.

The discharge portion 4 has a pump discharge port 8 connected to a fuel pipe (not shown) and supplies fuel to the internal combustion engine. The fuel discharged from the pump discharge port 8 is injected and supplied from the fuel injection valve toward the intake port of the internal combustion engine through, for example, the fuel pipe. Filter 11 connected to pump inlet 6
As shown in FIGS. 1 to 4, (1) the suction pipe portion 13
And (2) the filter section 31 connected to the inlet side of the suction pipe section 13.

(1) The suction pipe portion 13 has a pump suction port 6
Has a pump connecting outlet 14 connected to it, and a pump mounting flange 15 for attaching to the pump cover 17 extends from a side wall of the pump connecting outlet 14. The pump mounting flange 15 has an insertion hole 15a through which the filter fixing pin 18 formed in the pump cover 17 is inserted. As shown in FIG. 1, when the filter 11 is attached to the pump cover 17, the pump fixing pin 18 is inserted into the insertion hole 15a and the clip 16 is attached to the tip thereof.
Are elastically coupled. Communication passage 21 in the suction pipe 13
The inlet portion 19 thereof projects into the first damper chamber 41, and the first damper chamber 41 is formed by the first damper housing 20. A filter portion mounting flange 18 extends at an opening end of the first damper housing 20 in a direction orthogonal to the communication direction of the communication passage 21. The opening side of the first damper chamber 41 is separated from the second damper chamber 43 by the partition plate 23.

(2) The filter part 31 is composed of a filter frame 32 and a filter mesh 35, inside of which a filter part mounting flange 18 on the inlet side of the suction pipe part 13 is provided.
The suction port member 25 is joined to the end face of the partition plate 23 by sandwiching it. The suction port member 25 includes a member suction port 27, a second damper housing 26, and a pipe portion mounting flange 28. A second damper chamber 43 is formed inside the second damper housing 26 so as to be partitioned by the first damper chamber 41 and the partition plate 23. The second damper chamber 43 communicates with the first damper chamber 41 via the communication port 24 of the partition plate 23. The second damper chamber 43 extends to both blades as shown in FIG. 2, and the member suction port 27 is formed so as to be narrowed from both blades. The member suction port 27 projects from the second damper housing 26 toward the inlet side, and the upper wall 29 has a longer projecting length than the lower wall 30 thereof. This is to make it easier to suck the fuel from the member suction port 27 from the vicinity of the bottom of the fuel tank.

The filter section 31 comprises a filter frame 32 and a filter mesh 35 which covers the cavity of the filter frame. The filter frame 32 is formed in a tubular shape with a filter mesh 35 sandwiched between an inner frame 33 of the filter body and an outer frame 34 of the filter body, and the inner frame 37 of the filter end face portion on the end side and the filter end face portion of the filter frame 32. Similarly, the filter mesh 35 is sandwiched between the outer frame 38 and the outer frame 38 to be integrally molded.

When fuel passes from the outside of the filter mesh 35 to the inside of the filter portion 31, foreign matter in the fuel is filtered by the filter mesh 35, and the fuel from which the foreign matter is removed enters the inside of the filter portion 31. The fuel inside the filter portion 31 is supplied to the member suction port 27 of the suction port member 25.
1 enters in the direction of arrow A shown in FIG. 1, passes through the communication port 24 and the communication passage 21, and is sucked into the pump suction port 6 from the pump coupling outlet 14.

The filter 11 includes a suction pipe portion 13, a partition plate 23, a suction port member 25, and a filter frame flange portion 39.
And are joined by ultrasonic welding. As shown in FIG. 2, the first damper chamber 41 and the second damper chamber 43 have a communication port 24.
Are formed in series. The first damper chamber 41 is
When viewed from the communication passage 21, the passage sectional area is formed to be enlarged, and the second damper chamber 43 is formed to be larger than the passage sectional area of the member suction port 27.

Next, the operation will be described. The high frequency sound radiated from the pump suction port 6 of the pump unit 2 is mainly an impeller sound generated between the impeller and the fuel when the impeller rotates in the pump chamber, and is determined by the product of the number of blades and the rotation speed. It
Therefore, the difference in the number of blades, the fuel pressure to the pump,
The frequency changes as the applied voltage changes. High frequency sound,
When passing through the communication passage 21 inside the suction pipe portion 13 and the first damper chamber 41, the communication port 24, and the second damper chamber 43, the first damper chamber 41 and the second damper chamber 43 are damped in two stages. The damping effect of the high frequency sound at this time has a greater damping effect than the conventional damper filter. This will be explained based on experimental data.

(Experimental data) Experimental data of the sound pressure in liquid of the high frequency sound radiated from the pump suction port of this embodiment are shown in FIGS. 5 and 6. FIG. 5 shows experimental data comparing the case with one damper chamber and the case without a damper chamber. FIG. 6 shows experimental data comparing the case with two damper chambers and the case without a damper chamber.

As shown in FIG. 5, it can be seen that in the case of one damper chamber as a comparative example, the sound pressure in the liquid is larger when the primary frequency of the impeller is relatively lower than in the case without the damper chamber. On the other hand, as shown in FIG. 6, the damper chamber 2
It can be seen that the sound pressure in the liquid is low in all the wide frequency ranges from the region where the primary frequency of the impeller is low to the region where the primary frequency is high, when there is one, as compared with the case without the damper chamber. It has been found that a noise reduction effect can be obtained in a wider frequency range.

In the present embodiment, experiments have shown that the combination of the first damper chamber 41 and the second damper chamber 43 has a noise reducing effect in a wide frequency range.
In the present invention, the volumes and volume ratios of the first damper chamber and the second damper chamber can be appropriately set according to the rotational speed of the pump and the type of pump used. Further, the number of damper chambers is not limited to two, but three damper chambers may be provided in series.

When a small electric fuel pump having an outer diameter of 38 mm used in this experiment is used for a vehicle, the degree of discomfort of the primary noise of the impeller changes depending on the driving state of the vehicle, and the internal combustion engine of the vehicle is used during idling. Since the noise and running noise are low, the primary noise of the impeller tends to be noticeable and unpleasant. Even when the idling state is the same, the electric load of the vehicle such as an air conditioner, a lamp, and a radio is high due to the electric load state of the vehicle, and when the applied voltage to the fuel pump becomes low, the rotation speed of the fuel pump decreases.
When the electric load is low, the applied voltage of the fuel pump is high and the rotational speed of the fuel pump is high, so that the frequency is increased to approximately 7600 Hz.

When comparing FIG. 5 and FIG. 6 and examining it in more detail, the sound pressure in the liquid in the two damper chambers is lower than that in the one damper chamber at 5600 to 6400 Hz, and in this frequency band, that is, in the idling state. In addition, it can be seen that it is particularly effective in reducing noise when the electric load is high. Further, as described above, the small electric fuel pump discharges a necessary discharge amount at high fuel pressure by increasing the rotation speed. Therefore, even when idling, that is, when the fuel pressure is low, the rotation speed increases as noise of a high frequency of 5600 to 7600 Hz is generated. That is, it is particularly effective in reducing the noise of such a small electric fuel pump.

The noise generating source may be another boosting means instead of the impeller as in this embodiment. That is, it may be a positive displacement pump such as a roller pump or a trochoid pump. Further, instead of the noise from the pump chamber, the high frequency sound from other parts such as the brush portion and the bearing portion may be used.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a fuel pump filter to which the present invention is applied.

FIG. 2 is a plan view of the filter seen from the II direction shown in FIG.

3 is a sectional view taken along line III-III shown in FIG.

FIG. 4 is a sectional view taken along line IV-IV shown in FIG.

FIG. 5 is a data diagram showing the relationship between the frequency and the sound pressure in liquid when there is one damper chamber and when there is no damper chamber.

FIG. 6 is a data diagram showing the relationship between the frequency and the sound pressure in liquid when there are two damper chambers and when there is no damper chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel pump 2 Pump part 3 DC motor part 4 Discharge part 6 Pump intake port 7 Pump housing 11 Filter 13 Suction pipe part 19 Guide 20 First damper housing 21 Communication passage 23 Partition plate 24 Communication port 25 Suction port member 26 Second damper Housing 27 Member suction port 31 Filter part 33 Inner frame of filter body 34 Outer frame of filter body 35 Filter mesh 37 Inner frame of filter end face 38 Outer frame of filter end face 41 First damper chamber 43 Second damper chamber

Claims (6)

[Claims] 1. A filter mounted on a pump suction port side of a fuel pump, wherein a passage cross-sectional area is enlarged in two stages in the middle of a communication passage formed between a filter portion of the filter and the pump suction port. First
A fuel pump filter comprising a damper chamber and a second damper chamber. 2. The filter for a fuel pump according to claim 1, wherein the first damper chamber and the second damper chamber are integrally molded by a component forming a filter. 3. The fuel pump filter according to claim 1, wherein the first damper chamber and the second damper chamber are partitioned by a partition plate having a communication port. 4. The fuel pump filter according to claim 1, wherein the first damper chamber and the second damper chamber have different volumes. 5. A filter mounted on the pump suction port side of a fuel pump, wherein the passage cross-sectional area is expanded in three or more stages in the middle of a communication passage formed between a filter portion of the filter and the pump suction port. A filter for a fuel pump, which is provided with three or more damper chambers. 6. One end is connected to a pump suction port,
A suction pipe whose other end is connected to the filter part, a suction port member that is housed inside the filter part and has a suction port at one end, and between the suction pipe and the suction port member. A partition plate provided with a communication hole communicating in the plate thickness direction, having a first damper chamber on the suction pipe side partitioned by the partition plate, and a second damper on the suction port member side of the partition plate. A fuel pump filter having a chamber.