JP3207713B2 - Fuel pump device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pump mainly used for automobiles.

[0002]

2. Description of the Related Art A conventional fuel pump device will be described with reference to FIGS. In FIG. 5 showing a side sectional view of the fuel pump device and FIG. 6 showing a bottom view thereof, a fuel pump device 2 includes a cylindrical metal housing 8 and a motor unit 10 disposed on the upper part of the housing 8. And a pump unit 14 arranged via an aluminum die-cast cover member 12 attached to a lower portion of the housing 8. The fuel pump device 2 is attached to a fuel tank (not shown) via a metal bracket 6 in a substantially vertical shape.

[0003] The pump section 14 will be described in detail. A drive shaft 18 of a rotor 16 of an electric motor constituting the motor section 10 is inserted into a hole formed in the center of the cover member 12. The drive shaft 18 is connected to the drive shaft 1.
First impeller 20 and second impeller 2 rotating with
2 are installed. These impellers 20, 22
Is made of synthetic resin and has a plurality of cutouts (symbols omitted) as blade grooves along the outer peripheral edge. Further, a cover member 12 for accommodating the impellers 20 and 22, a fixing plate 28 made of aluminum die-cast, and a housing body 26 are fixed to a lower portion of the housing 8 by caulking a lower end edge of the housing 8.

[0004] As is apparent from the drawing, the cover member 12,
The fixed plate 28 and the housing body 26 form a substantially C-shaped first pump chamber 42 and a second pump chamber 44 along the outer peripheral portions of the impellers 20 and 22, respectively.
The pump chambers 42 and 44 are communicated with each other through a through hole (not shown) formed in the fixed plate 28.
Further, the second pump chamber 44 is communicated into the housing 8 through an outlet port 46 formed in the cover member 12, and the first pump chamber 42 is communicated into the fuel tank through an inlet port 48 formed in the housing body 26. I have. The fuel filter 31 is connected to the inlet port 48.

In FIG. 7 showing a partially cutaway bottom view of the fuel pump device 2 and FIG. 8 showing a side sectional view of the housing body 26, the housing body 26 has a small diameter communicating with the first pump chamber 42. A vapor discharge hole 50 is formed. The vapor discharge hole 50 is for removing a vapor in the fuel flowing in the first pump chamber 42, and is formed by a drill or the like at a position away from the inlet port 48 by a predetermined angle. A chamber 62 is formed on the exit side of the housing body 26 where the vapor discharge hole 50 is formed. This chamber 62
Is closed by a cover plate 53 made of metal or resin fitted into the recess 52 by press-fitting or the like at the lower end opening of the recess 52 drilled with a hole diameter larger than the diameter of the vapor discharge hole 50 by a drill or the like. It is formed by.

Further, on the side surface of the housing body 26, a small-diameter throttle hole 60 which penetrates the wall surface of the chamber 62 in the radial direction, that is, is substantially perpendicular to the vapor discharge hole 50, is formed by drilling with a drill or the like. I have.
Therefore, the chamber 62 opens into the fuel tank through the throttle hole 60. The vapor discharge hole 50 and the chamber 6
2 and the throttle hole 60 form a vapor discharge passage 63 communicating from the first pump chamber 42 to the internal space of the fuel tank. The fuel pump device 2 is attached to the bracket 6 with a rubber cushion 54 interposed under the housing body 26 as shown in FIG. The cushion member 54 prevents the vibration of the fuel pump device 2 from being transmitted to the bracket 6.

Next, the operation of the fuel pump device 2 configured as described above will be described. First, impeller 20,2
When the fuel pump 2 rotates, the fuel in the first pump chamber 42 is pressurized and passes through the through-hole formed in the fixed plate 28 so that
It is led to the pump chamber 44. This fuel is supplied to the second pump chamber 44
It is further boosted within. The fuel is supplied to the inlet port 4 by the two-stage pressure increasing action by the impellers 20, 22 described above.
8 and is pumped into the housing 8 from the outlet port 46 via both pump chambers 42 and 44.

In this case, the vapor generated by the temperature rise in the fuel tank or the vapor generated by the fuel suction action passes through the vapor discharge hole 50 of the housing body 26 as the fuel mixed with the vapor, and passes through the chamber 62.
After being guided into the fuel tank, it is discharged through the throttle hole 60 into the fuel tank. As a result, the vapor content of the fuel sent from the housing 8 to the engine (not shown) is inevitably reduced, and the so-called vapor lock phenomenon is prevented. As the fuel pump device as described above, for example, there is one disclosed in Japanese Utility Model Publication No. 6-14073 previously proposed by the same applicant. The description of the installation of the fuel pump device 2 in the fuel tank is described in Japanese Utility Model Publication No. 6-14.
The description is omitted because it is the same as that of JP-A No. 073.

[0009]

In the fuel pump device constructed as described above, the fuel mixed with the vapor is discharged into the fuel in the fuel tank through the throttle hole 60 through the vapor discharge passage 63. (In FIGS. 7 and 8,
Arrow)). This is because the pressure difference between the inside of the high-pressure pump chamber 42 and the inside of the low-pressure fuel tank is large.
It is considered that because 0 is open to the inside of the fuel tank, the high-pressure vapor-mixed fuel is directly discharged into the low-pressure fuel tank. Another possible reason is that the pressure of the discharged fuel mixed with the vapor fluctuates due to the fluctuation of the pressure inside the pump chamber 42 caused by the fluctuation of the operating voltage of the pump.

The fuel mixed into the fuel tank vigorously discharged into the fuel tank impinges on the bracket 6 or on the wall surface of the sub-tank containing the fuel pump device 2 and the fuel filter 31 to cause vibration and noise. It may be.

The technical problems to be solved by the present invention are as follows:
By lowering the release rate of fuel mixed with vapor,
It is an object of the present invention to provide a fuel pump device capable of reducing vibration and noise.

[0012]

According to a first aspect of the present invention, there is provided a fuel pump apparatus having a vapor discharge passage communicating from a pump chamber to an internal space of a fuel tank. A vapor discharge passage provided between the internal space and the vapor discharge passage for discharging the vapor-mixed fuel discharged through the vapor discharge passage; one end of the vapor discharge passage is merged in the middle of the vapor discharge passage, and the other end is connected to the internal space of the fuel tank; A fuel pump device, comprising: a fuel suction passage which is opened and through which fuel sucked from inside the fuel tank by fuel mixed with vapor passing through the vapor outlet passage.

[0013]

According to the first aspect of the present invention, the fuel mixed with the vapor including the vapor is discharged from the pump chamber through the vapor discharge passage, and then discharged into the fuel tank through the vapor discharge passage. . At this time, the fuel mixed with the vapor sucks the fuel in the fuel tank from the fuel suction passage when passing through the vapor outlet passage, and slowly flows out into the fuel tank while mixing with the sucked fuel.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 to 3 of the present invention will be described in order. Embodiment 1 Embodiment 1 will be described with reference to FIGS. 1A is a side view of the housing body, FIG. 1B is a partially cutaway bottom view thereof, and FIG.
FIG. 3A is a sectional view taken along line AA of FIG. Since the fuel pump device of the present embodiment is a modification of the conventional example, the changed portion will be described in detail. Is omitted. 1 and 2, the housing body 26 has a vapor outlet passage 65 on a straight line L1 perpendicular to the axis C1 of the chamber 62 of the vapor discharge passage 63 and extending in a direction other than the radial direction of the housing body 26.
Are formed by drilling with a drill or the like. One end of the vapor outlet passage 65 communicates with the chamber 62 via the throttle hole 60, and the other end is open to the internal space of the fuel tank. Therefore, unlike the conventional device, the throttle hole 60 does not directly open into the internal space of the fuel tank. The vapor outlet passage 65 is formed with a passage diameter d4 larger than the diameter d3 of the throttle hole 60. The vapor discharge hole 50 and the chamber 62 are formed on the same axis C1.

In the housing body 26, a fuel suction passage 67 is formed by drilling or the like on a straight line L2 intersecting the straight line L1 at an angle θ. One end of the fuel suction passage 67 is open to the internal space of the fuel tank, and the other end thereof is exchanged in the middle of the vapor outlet passage 65, specifically, at a position near the throttle hole 60. The fuel suction passage 67 has a passage diameter d5 smaller than the passage diameter d4 of the vapor outlet passage 65.

In the present embodiment, the diameter d1 of the vapor discharge hole 50 is 1.2 mm, the diameter d2 of the chamber 62 is 4.4 mm, and the diameter d3 of the throttle hole 60 is 1.0.
mm, the passage diameter d4 of the vapor outlet passage 65 is 4.0 mm.
The passage diameter d5 of the fuel intake passage 67 is 3.0 mm;
The angle θ is set to 60 °, and the volume of the chamber 62 is set to 28 mm ³ .

According to the fuel pump device, the fuel mixed with the vapor including the vapor is discharged from the pump chamber 42 through the vapor discharge hole 50, the chamber 62 and the throttle hole 60 of the vapor discharge passage 63, and then into the vapor outlet passage 65.
Through the fuel tank. At this time, the fuel mixed with the vapor sucks the fuel in the fuel tank from the fuel suction passage 67 when passing through the vapor outlet passage 65, and slowly flows out into the fuel tank while mixing with the sucked fuel. As described above, since the vapor-mixed fuel sucks the fuel from the inside of the fuel tank into the vapor outlet passage 65 through the fuel suction passage 67, the release speed of the vapor-mixed fuel is reduced. 6 or the collision with the tank wall can be mitigated, so that the vibration and noise caused by the collision are reduced. When the release rate of the fuel mixed with the vapor between the conventional product and the present embodiment was measured, it was found that the conventional product was 30 c
At m / sec, this product was 10 cm / sec, indicating that the release rate was low.

Embodiment 2 Embodiment 2 will be described with reference to FIG. FIG. 3A is a side view of the housing body, and FIG. 3B is a bottom view thereof. In this embodiment, when the housing body 26 is die-cast, passage grooves 65a, 67a corresponding to the vapor outlet passage 65 and the fuel suction passage 67 are formed in advance on the bottom surface of the housing body 26, and the step formed on the groove wall is formed. A vapor outlet passage 65 and a fuel suction passage 67 are formed by fitting a substantially L-shaped cover plate 71 made of metal or resin into the 69 by press fitting or the like so as to close the openings of the grooves 65a and 67a. It is. According to this example, although the number of parts and the number of assembling steps of the cover plate 71 are increased as compared with the case where the vapor outlet passage 65 and the fuel suction passage 67 are formed by drilling, the grooves 65a and 67a are simultaneously formed with the die casting of the housing body 26. The groove can be formed easily.

Embodiment 3 Embodiment 3 will be described with reference to FIG. 4A is a side view of the housing body, and FIG. 4B is a bottom view thereof. In the present embodiment, the cushion member 54 interposed below the housing body 26 when the fuel pump device 2 is attached to the bracket 6 is used without using the cover plate 71 of the second embodiment. That is, the groove openings of the passage grooves 65 a and 67 a formed on the bottom surface of the housing body 26 are closed by the cushion material 54. In FIG. 4B, the cushion member 54 is omitted. According to this example, the cover plate 71 in the second embodiment can be eliminated, and the number of parts and the number of assembling steps related to the lid plate 71 can be reduced. In addition, the passage groove 65
The steps 69a, 67a can also be eliminated, and the groove shape can be simplified.

In the above embodiment, the vapor discharge hole 5
Although the passage formed by the chamber 0, the chamber 62, and the throttle hole 60 is treated as the vapor discharge passage 63, when the vapor discharge passage 63 is formed only by the vapor discharge hole 50, the vapor discharge passage 65 is connected to the vapor discharge hole 50. And the configuration of the vapor discharge passage 63 is not limited.

[0021]

According to the fuel pump device of the present invention, the fuel mixed with the vapor sucks the fuel from the fuel tank through the fuel suction passage into the vapor outlet passage, so that the release speed of the fuel mixed with the vapor is reduced. Therefore, the collision with the bracket or the tank wall surface at the time of discharging the fuel mixed with the vapor can be reduced, and the vibration and noise caused by the collision can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a housing body of a fuel pump device according to a first embodiment.

FIG. 2 is a sectional view of a housing body.

FIG. 3 is an explanatory view showing a housing body of a fuel pump device according to a second embodiment.

FIG. 4 is an explanatory diagram illustrating a housing body of a fuel pump device according to a third embodiment.

FIG. 5 is a cross-sectional view of a fuel pump device showing a conventional example.

FIG. 6 is a bottom view of FIG. 5;

FIG. 7 is a partially cutaway bottom view of FIG. 5;

FIG. 8 is a sectional view of a housing body.

[Explanation of symbols]

 42 Pump room 63 Vapor discharge passage 65 Vapor outlet passage 67 Fuel intake passage

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02M 37/20 F02M 37/10

Claims (1)

(57) [Claims] 1. A fuel pump device having a vapor discharge passage communicating from a pump chamber to an internal space of a fuel tank, wherein the fuel pump device is provided between the vapor discharge passage and the internal space of the fuel tank, and is discharged through the vapor discharge passage. A vapor outlet passage for discharging the fuel mixed with the vapor, one end of which is joined in the middle of the vapor outlet passage and the other end is opened to the internal space of the fuel tank; A fuel suction passage through which fuel sucked from inside passes;
A fuel pump device comprising: