JP2009127471A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small fuel supply device operating silently. <P>SOLUTION: This fuel supply device 10 has a cover 20 blocking up an opening 100a of an upper surface of a fuel tank 100, a shaft 30 extending in the fuel tank 100 from the cover 20, and a fuel pump unit 92 supported by the shaft 30. The fuel pump unit 92 has a pump bracket 40 having a shaft storage hole 46a for inserting the shaft 30, and a fuel pump 60 fixed to the pump bracket 40. A first elastic member 48 for locking the pump bracket 40 on the shaft 30, is interposed between the shaft 30 and the shaft storage hole 46a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel supply device that supplies fuel in a fuel tank to the outside.

Patent Document 1 discloses a fuel supply device that supplies fuel in a fuel tank to the outside. This fuel supply device has a shaft extending in the fuel tank and a fuel pump unit fixed to the shaft. The fuel pump unit includes a cylindrical housing and a fuel pump accommodated in an inner hole of the housing. A plurality of leaf springs are installed in the inner hole of the housing. The leaf spring is interposed between the inner hole of the housing and the fuel pump, and locks the fuel pump with respect to the housing.
When the fuel supply device supplies the fuel in the fuel tank to the outside, the fuel pump is operated. When the fuel pump is activated, the fuel pump vibrates. The vibration of the fuel pump is absorbed by the leaf spring. This suppresses the vibration of the fuel pump from being transmitted to the fuel tank through the shaft. Therefore, this fuel supply device can operate silently.

JP-A-2-286864

  In the fuel supply apparatus described above, a leaf spring is installed between the fuel pump and the housing. The fuel pump has a relatively large diameter. In the above-described fuel supply apparatus, it is necessary to dispose a leaf spring around the fuel pump having a large diameter, so that the housing becomes large. That is, the above-described fuel supply apparatus has a problem that the apparatus itself becomes large.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel supply device that is small in size and operates silently.

The fuel supply device of the present invention is attached to a fuel tank and supplies the fuel in the fuel tank to the outside. This fuel supply apparatus has a lid, a shaft, and a fuel pump unit. The lid closes the opening on the upper surface of the fuel tank. The shaft extends from the lid into the fuel tank. The fuel pump unit is supported by the shaft. The fuel pump unit has a pump bracket and a fuel pump. The pump bracket includes a shaft receiving hole into which the shaft is inserted. The fuel pump is fixed to the pump bracket. A first elastic member is interposed between the shaft and the shaft housing hole. The pump bracket is locked to the shaft by the first elastic member.
In this fuel supply device, the pump bracket is locked to the shaft via the first elastic member. Therefore, when the fuel pump is operated, the fuel pump and the pump bracket vibrate, but the vibration is hardly transmitted from the pump bracket to the shaft. Therefore, the vibration is suppressed from being transmitted to the fuel tank. This fuel supply device can operate silently. Also, the shaft for fixing the pump is usually much thinner than the pump. Therefore, even if the first elastic member is interposed between the shaft and the shaft housing hole, the fuel supply device is hardly increased in size. That is, a small fuel supply device can be provided.

A fuel pump having a rotating impeller can be used in the fuel supply device described above. In this case, it is preferable that the position of the center of gravity of the fuel pump unit is included in the presence of the first elastic member in the direction of the impeller rotation axis.
The “fuel pump unit” means a structure constituted by a fuel pump, a bracket, and an object fixed so as not to move relative to other fuel pumps. Therefore, an object (for example, a filter attached to the fuel pump via an elastic member or a tube connected to the fuel pump) attached so as to be movable relative to the fuel pump is referred to as “fuel pump unit”. Is not included in the fuel pump unit.
The fuel pump unit normally vibrates by a plowing motion (precession motion) centering on the impeller rotating shaft when the fuel pump is stopped and having the center of gravity of the fuel pump unit as a vibration node. Therefore, vibration is minimized at the position of the center of gravity of the fuel pump unit in the impeller rotation axis direction. In the fuel supply device described above, the position of the center of gravity of the fuel pump unit is included in the presence range of the first elastic member in the impeller rotation axis direction. That is, the bracket and the shaft are locked at a position where vibration is smallest. Therefore, vibration is not easily transmitted to the shaft. This fuel supply device can operate more silently.

In the fuel supply device described above, one end of the shaft accommodation hole extends to the position of the center of gravity of the fuel pump unit in the direction of the impeller rotation axis, and the second end interposed between the shaft and the shaft accommodation hole at the other end of the shaft accommodation hole. It is preferable to further have an elastic member.
According to such a structure, a pump bracket can be more reliably latched with respect to a shaft. Moreover, since the both ends of the shaft accommodation hole are being fixed to the shaft via the elastic member (a 1st elastic member and a 2nd elastic member), it is suppressed that a vibration is transmitted to a shaft.

  ADVANTAGE OF THE INVENTION According to this invention, while being small, the fuel supply apparatus which operate | moves silently can be provided.

The main features of the embodiments described in detail below are listed first.
(Feature 1) In the fuel supply device of the first embodiment, only the first elastic member is interposed between the shaft housing hole and the shaft.
(Characteristic 2) In the fuel supply device of the first embodiment, the first elastic member exists only in the vicinity of the center of gravity of the fuel pump unit in the impeller rotational axis direction. More specifically, in the fuel supply device of the first embodiment, in the impeller rotational axis direction, the first elastic member is within a distance range of 20% of the axial length of the fuel pump unit from the position of the center of gravity of the fuel pump unit. Only exists.
(Characteristic 3) The fuel supply devices of the first and second embodiments have only one shaft.

  The fuel supply device of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic side view of a fuel supply device 10 of the first embodiment. The fuel supply device 10 is used by being attached to the fuel tank 100. The fuel supply device 10 includes a lid 20, a shaft 30, a pump bracket 40, a fuel pump 60, a sender gauge 80, and a fuel filter 88.

As shown in FIG. 1, an opening 100 a is formed on the upper surface of the fuel tank 100. The lid 20 is fixed to the fuel tank 100 with the opening 100a closed. The lid 20 is provided with a flange 22, a fuel port 24, and a pressure regulator 27.
The flange 22 extends downward from the lid 20. The flange 22 supports the upper end of the shaft 30.
The upper end of the fuel port 24 is connected to an external device such as an engine by a fuel supply path (not shown). One end of a fuel tube 26 is connected to the lower end of the fuel port 24. As will be described later, the other end of the fuel tube 26 is connected to the fuel pump 60. The fuel discharged from the fuel pump 60 passes through the fuel tube 26 and the fuel port 24 and is sent to an external device such as an engine.
The pressure regulator 27 discharges part of the fuel that passes through the fuel port 24 into the fuel tank 100. Thereby, the pressure of the fuel in the fuel port 24 is adjusted to a predetermined pressure.

  An upper end of the shaft 30 is fixed to the flange 22 of the lid 20. The shaft 30 extends vertically downward from the lid 20. The lower end of the shaft 30 is inserted into the shaft housing portion 46 of the pump bracket 40.

  The pump bracket 40 includes a lower bracket 42 and an upper bracket 52.

The lower bracket 42 includes a substantially cylindrical pump housing portion 44 and a substantially tubular shaft housing portion 46. The pump housing portion 44 and the shaft housing portion 46 are integrally formed.
FIG. 2 shows a cross-sectional view taken along the line II-II in FIG. As shown in FIG. 2, the shaft 30 is inserted into the inner hole 46 a (hereinafter referred to as the shaft accommodation hole 46 a) of the shaft accommodation portion 46. A protruding portion 32 is formed on the outer peripheral surface of the shaft 30. An engaging portion 46 b that engages with the protruding portion 32 is formed in the shaft accommodating hole 46 a in a range corresponding to the protruding portion 32. This prevents the lower bracket 42 from rotating relative to the shaft 30. A clearance is provided over the entire region between the shaft 30 and the shaft housing hole 46a (including between the protruding portion 32 and the engaging portion 46b). At the lower end of the shaft accommodation hole 46a, a rubber bush accommodation portion 46c having an enlarged diameter is formed. A cylindrical rubber bush 48 is press-fitted into the rubber bush housing 46c. That is, the outer peripheral surface of the rubber bush 48 is in pressure contact with the rubber bush housing portion 46c. The shaft 30 is press-fitted into the inner hole 48 a of the rubber bush 48. Accordingly, the lower bracket 42 is locked to the shaft 30 via the rubber bush 48. The rubber bush 48 is formed of rubber (that is, an elastic body). Therefore, the lower bracket 42 can move relative to the shaft 30 within a range in which the rubber bush 48 is elastically deformed. Rings 34 and 36 are fixed to the shaft 30 at the positions of the upper end and the lower end of the shaft accommodation hole 46a. The rings 34 and 36 prevent the lower bracket 42 from moving greatly in the axial direction of the shaft 30 relative to the shaft 30.
FIG. 3 shows a schematic longitudinal sectional view of the fuel pump 60 and the pump bracket 40. As shown in FIG. 3, the fuel pump 60 is inserted into the inner hole 44 a of the pump housing portion 44. The upper bracket 52 has a shape corresponding to the upper part of the fuel pump 60. The upper bracket 52 is fixed to the lower bracket 42 in a state where the upper portion of the fuel pump 60 is accommodated. As a result, the fuel pump 60 is fixed to the pump bracket 40.

  As shown in FIG. 1, the upper bracket 52 is provided with a sender gauge 80 that measures the fuel water level in the fuel tank 100. The sender gauge 80 includes a fixed portion 82, a shaft 84, and a float 86. The fixing portion 82 is fixed to the upper bracket 52. A shaft 84 is attached to the fixed portion 82 so as to be rotatable about a rotation portion 84a. A float 86 is fixed to the tip of the shaft 84. The float 86 floats on the fuel stored in the fuel tank 100. Therefore, the shaft 84 rotates around the rotating portion 84 a according to the fuel water level in the fuel tank 100. The fixing unit 82 detects the fuel water level in the fuel tank 100 by detecting the rotation angle of the shaft 84. The fixing portion 82 is electrically connected to a control device outside the fuel tank 100, and the fuel level detected by the fixing portion 82 is read by the control device.

As shown in FIG. 3, the fuel pump 60 includes a pump casing 62. A motor chamber 62a and an impeller chamber 62b are formed in the pump casing 62.
A rotor 64 is accommodated in the motor chamber 62a. The rotor 64 includes a shaft 64a, an armature 64b, a coil (not shown), and the like. Electric power can be supplied to the coil of the rotor 64 from the outside. The rotor 64 is rotatably supported in the motor chamber 62a. A permanent magnet 62e is disposed around the rotor 64. The permanent magnet 62e is fixed to the pump casing 62. The lower end of the shaft 64a extends into the impeller chamber 62b.
A substantially disk-shaped impeller 66 is accommodated in the impeller chamber 62b. The lower end of the shaft 64 a is engaged with the shaft hole of the impeller 66. Therefore, the impeller 66 rotates with the shaft 64a. The impeller chamber 62b and the motor chamber 62a communicate with each other through a fuel discharge port 62g. The impeller chamber 62b communicates with the outside of the pump casing 62 through a fuel suction port 62f.
A fuel discharge port 62 h that communicates with the outside is formed in the upper portion of the pump casing 62. The fuel tube 26 is connected to the fuel discharge port 62h.

  As shown in FIGS. 1 and 3, a fuel filter 88 is connected to the fuel inlet 62 f of the fuel pump 60. The fuel filter 88 includes a filter portion 88a and a connection tube 88b. The filter portion 88a is a mesh-like filter that allows fuel to flow inside. The connection tube 88b connects the fuel inlet 62f of the fuel pump 60 and the filter portion 88a. Therefore, the fuel in the fuel tank 100 can flow into the fuel inlet 62f through the filter portion 88a and the connection tube 88b. The connection tube 88b is formed of an elastic member such as rubber. Therefore, the fuel filter 88 can move relative to the fuel pump 60.

  Next, an operation of supplying the fuel in the fuel tank 100 to an external device such as an engine by the fuel supply device 10 will be described. When the fuel supply device 10 is operated, the fuel pump 60 is operated. That is, power is supplied to the coil of the rotor 64. When power is supplied to the coil, the rotor 64 rotates. As a result, the impeller 66 rotates in the impeller chamber 62b. When the impeller 66 rotates, the fuel in the fuel tank 100 passes through the fuel filter 88 and the fuel suction port 62f and is sucked into the impeller chamber 62b. When the fuel passes through the fuel filter 88, foreign matters in the fuel are removed. The fuel sucked into the impeller chamber 62b passes through the fuel discharge port 62g, the motor chamber 62a, and the fuel discharge port 62h and is discharged to the fuel tube 26. The fuel discharged to the fuel tube 26 passes through the fuel port 24 and is supplied to an external device such as an engine. When the fuel passes through the fuel port 24, a part of the fuel in the fuel port 24 is discharged by the pressure regulator 27. Thereby, the pressure of the fuel in the fuel port 24 is adjusted. Therefore, fuel whose pressure is adjusted is supplied to an external device such as an engine.

  When the fuel pump 60 is operated, the fuel pump 60 vibrates. More specifically, the fuel pump 60 vibrates integrally with a member fixed so as not to move relative to the fuel pump 60. Hereinafter, a member (including the fuel pump 60) that vibrates integrally with the fuel pump 60 when the fuel pump 60 is operated is referred to as a fuel pump unit 92. Specifically, the fuel pump unit 92 includes a fuel pump 60, a pump bracket 40, and a fixing part 82 of the sender gauge 80. The fuel filter 88 is connected to the fuel pump 60 by a connection tube 88b, which is an elastic member, and does not vibrate integrally with the fuel pump 60. Therefore, the fuel filter 88 is not included in the fuel pump unit 92. Further, the shaft 84 and the float 86 of the sender gauge 80 are rotatable with respect to the fixed portion 82 and do not vibrate integrally with the fuel pump 60 and thus are not included in the fuel pump unit 92. Further, the fuel tube 26 and the electrical wiring connected to the fuel pump 60 are not included in the fuel pump unit 92 because they do not vibrate integrally with the fuel pump 60. Further, the shaft 30 is fixed to the pump bracket 40 via the rubber bush 48 and does not vibrate integrally with the fuel pump 60, so that the shaft 30 is not included in the fuel pump unit 92.

Before describing the vibration of the fuel pump unit 92, the position of the center of gravity of the fuel pump unit 92 will be described. FIG. 4 is a schematic diagram for explaining the position of the center of gravity of the fuel pump unit 92. Note that reference numeral 94 in FIG. 4 indicates the center of gravity of the fuel pump unit 92. Reference numeral 96 indicates a rotation shaft of the impeller 66 of the fuel pump 60. As shown in the drawing, the position of the center of gravity 94 in the height direction (rotation shaft 96 direction) of the fuel pump unit 92 is substantially equal to the position of the rubber bush 48 in the height direction. That is, the center of gravity position 94 is included in the existence range of the rubber bush 48 in the direction of the rotation shaft 96.
A symbol L1 in FIG. 4 indicates the height of the fuel pump unit 92 (the length in the direction of the rotating shaft 96). A symbol L2 in FIG. 4 indicates a distance that is 20% of the distance L1. As shown in the figure, the rubber bush 48 exists only within a range within a distance L2 from the position of the center of gravity 94 of the fuel pump unit 92 in the direction of the rotation shaft 96.

Next, the vibration of the fuel pump unit 92 will be described. FIG. 5 schematically shows the vibration of the fuel pump unit 92 when the fuel pump 60 is in operation. In FIG. 5, only the outline of the fuel pump unit 92 is shown in consideration of easy viewing. Further, in FIG. 5, the vibration amplitude of the fuel pump unit 92 is shown larger than the actual amplitude in consideration of easy viewing. 5 indicates the position of the center of gravity 94 of the fuel pump unit 92 when it is stationary (when the fuel pump 60 is stopped). Reference numeral 96 indicates the position of the rotating shaft of the impeller 66 when stationary (when the fuel pump 60 is stopped). As shown in the figure, when the fuel pump 60 is operated, the fuel pump unit 92 performs a plowing motion (precession motion) around the direction of the rotating shaft 96 when stationary. At this time, a position that substantially coincides with the center of gravity 94 of the fuel pump unit 92 (a position in the direction of the rotating shaft 96) is a node of the pruning motion (that is, a position having the smallest amplitude).
As described above, the fuel pump unit 92 is locked to the shaft 30 via the rubber bush 48 that is an elastic body. Therefore, the fuel pump unit 92 can move relative to the shaft 30 within a range in which the rubber bush 48 is elastically deformed. Therefore, vibration of the shaft 30 together with the fuel pump unit 92 is suppressed. That is, the vibration of the fuel pump unit 92 is suppressed from being transmitted to the shaft 30.
The fuel pump unit 92 is locked to the shaft 30 by the rubber bush 48 at substantially the same position as the position of the center of gravity 94 of the fuel pump unit 92 (position in the direction of the rotating shaft 96) (see FIG. 4). That is, the fuel pump unit 92 is locked to the shaft 30 at a position where the amplitude of the plowing motion is the smallest. Therefore, the vibration of the fuel pump unit 92 is more difficult to be transmitted to the shaft 30. In particular, since the rubber bush exists only within the range within the distance L2 from the position of the center of gravity 94 of the fuel pump unit 92 (that is, the rubber bush exists only within the range where the amplitude of the plowing motion is small). The effect of suppressing vibration transmission to the shaft 30 is enhanced.
Thus, in the fuel supply device 10 of the first embodiment, the vibration of the fuel pump unit 92 is difficult to be transmitted to the shaft 30. Therefore, the vibration of the fuel pump unit 92 is suppressed from being transmitted to the lid 20 and the fuel tank 100 via the shaft 30. Therefore, the fuel supply device 10 can operate more silently. Further, since the rubber bush 48 need only be disposed around the shaft 30, the fuel supply device 10 does not increase in size. A small fuel supply device 10 can be provided.

  Next, a fuel supply apparatus according to a second embodiment will be described. The fuel supply device of the second embodiment is different from the fuel supply device 10 of the first embodiment in the locking portion between the lower bracket 42 and the shaft 30, and the other configuration is the fuel supply device of the first embodiment. 10 has the same configuration. Therefore, hereinafter, only the engaging portion between the lower bracket 42 of the fuel supply device of the second embodiment and the shaft 30 will be described.

FIG. 6 shows a cross-sectional view of the engaging portion between the lower bracket 42 and the shaft 30 of the fuel supply device of the second embodiment. As shown in FIG. 6, in the fuel supply device of the second embodiment, a rubber bush 48 is installed at the lower end of the shaft housing hole 46a in the same manner as the fuel supply device 10 of the first embodiment (that is, the rubber bush). 48 is installed at substantially the same height as the center of gravity of the fuel pump unit 92). Furthermore, in the fuel supply device of the second embodiment, a rubber bush 49, which is an elastic body, is installed at the upper end of the shaft housing hole 46a. That is, a rubber bush housing portion 46d is formed at the upper end of the shaft housing hole 46a, and the rubber bush 49 is press-fitted into the rubber bush housing portion 46d. The shaft 30 is press-fitted into the inner hole 49 a of the rubber bush 49. As a result, the lower bracket 42 is locked to the shaft 30 via the rubber bush 48 and the rubber bush 49.
Thus, the lower bracket 42 can be locked to the shaft 30 more firmly by locking the lower bracket 42 to the shaft 30 at both upper and lower ends of the shaft accommodation hole 46a. Further, since the rubber bush 49 is an elastic body, the vibration of the fuel pump unit is suppressed from being transmitted to the shaft 30 on the upper end side of the shaft housing hole 46a. Therefore, the fuel supply device of the second embodiment can be operated silently.
Note that the amplitude of the fuel pump unit is larger at the position where the rubber bush 49 is installed than at the position where the rubber bush 48 is installed (see FIG. 5). Therefore, the rubber bush 49 may be formed of a material that is easier to deform (soft) than the rubber bush 48. By forming the rubber bush 49 in this way, vibration transmission on the upper end side of the shaft housing hole 46a can be further suppressed.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

1 is a schematic side view of a fuel supply device 10. FIG. II-II sectional view taken on the line of FIG. FIG. 2 is a schematic cross-sectional view of a fuel pump 60 and a pump bracket 40. Explanatory drawing of the gravity center 94 of the fuel pump unit 92. FIG. Explanatory drawing of the vibration of the fuel pump unit 92. FIG. Sectional drawing corresponding to FIG. 2 of the fuel supply apparatus of 2nd Example.

Explanation of symbols

10: Fuel supply device 20: Lid 30: Shaft 40: Pump bracket 44: Pump housing portion 46: Shaft housing portion 48: Rubber bush 60: Fuel pump 62: Pump casing 64: Rotor 66: Impeller 80: Sender gauge 88: Fuel filter 92: Fuel pump unit 94: Center of gravity 96: Rotating shaft

Claims (3)

A fuel supply device attached to the fuel tank and supplying the fuel in the fuel tank to the outside,
A lid that closes the opening on the upper surface of the fuel tank;
A shaft extending from the lid into the fuel tank;
A fuel pump unit supported by a shaft;
The fuel pump unit
A pump bracket having a shaft receiving hole into which the shaft is inserted;
Has a fuel pump fixed to the pump bracket,
A fuel supply device comprising a first elastic member interposed between the shaft and the shaft housing hole and locking the pump bracket to the shaft. The fuel pump has a rotating impeller,
2. The fuel supply device according to claim 1, wherein the center of gravity of the fuel pump unit is included in the presence of the first elastic member in the direction of the impeller rotational axis. One end of the shaft housing hole extends to the center of gravity of the fuel pump unit in the direction of the impeller rotation axis,
The fuel supply device according to claim 2, further comprising a second elastic member interposed between the shaft and the shaft accommodation hole at the other end of the shaft accommodation hole.

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