Fuel pump vibration-damping structure and vapor separator tank

Abstract

This vibration-damping structure for a fuel pump (20) comprises: the fuel pump (20); a tank body (14) that supports the fuel pump (20); and a rubber cushion (30) that is interposed between the fuel pump (20) and the tank body (14), and attenuates fuel pump (20) vibrations. The rubber cushion (30) is provided with: a body section (31) having a cutout groove (32) which makes space for a fuel pipe (25) of a fuel filter (24) connected to the fuel pump (20); and a mating part (40) which is mated to the fuel pump (20) and has a split groove that is contiguous with the cutout groove (32).

Description

Vibration Isolation Structure of Fuel Pump and Vapor Separator Tank

[0001] The technology disclosed in this specification relates to a vibration isolation structure of a fuel pump and a vapor separator tank.

[0002] Japanese Patent Application Laid-Open No. 2000-45900 describes a vibration isolation structure of a fuel pump, which includes a fuel pump, a bracket (corresponding to the "pump support member" in this specification) for supporting the fuel pump, and a vibration isolation rubber interposed between the fuel pump to attenuate the vibration of the fuel pump.

[0003] According to Japanese Patent Application Laid-Open No. 2000-45900, although the vibration isolation rubber is formed in a fan shape to avoid a filter connected to the fuel pump, it does not have a cylindrical fitting portion that fits into the fuel pump. Therefore, when assembling the bracket (including re-assembling) after attaching the vibration isolation rubber to the fuel pump, there is a problem that the vibration isolation rubber is likely to be displaced due to interference (contact) of the bracket with the vibration isolation rubber, and is likely to fall off due to the displacement.

[0004] Conventionally, it has been desired to suppress the displacement of the vibration isolation rubber and its falling off due to the displacement that occur when assembling the pump support member after attaching the vibration isolation rubber to the fuel pump.

[0005] According to the first disclosure, the vibration isolation structure of the fuel pump includes a fuel pump, a pump support member for supporting the fuel pump, and a vibration isolation rubber interposed between the fuel pump and the pump support member to attenuate the vibration of the fuel pump. The vibration isolation rubber includes a main body portion having a notch groove for avoiding a fuel pipe of a fuel filter connected to the fuel pump, and a fitting portion having a split groove continuous with the notch groove and fitting into the fuel pump.

[0006] According to the first disclosure, when attaching the vibration-damping rubber to the fuel pump, the fuel pipe of the fuel filter is fitted to the fuel pump by passing the fuel pipe through the split groove of the fitting portion, thereby positioning the fuel pipe within the notched groove of the main body. Subsequently, by assembling the pump support member, the main body is interposed between the fuel pump and the pump support member. Therefore, by fitting the fitting portion of the vibration-damping rubber to the fuel pump, it is possible to suppress misalignment of the vibration-damping rubber and its detachment due to such misalignment that may occur when assembling the pump support member.

[0007] According to the second disclosure, the groove wall surface of the groove is provided with a protruding portion that reduces the groove width.

[0008] According to the second disclosure, when passing the fuel pipe of the fuel filter along the groove of the fitting portion, the protruding portion elastically deforms, thereby allowing the passage of the fuel pipe. Furthermore, when reassembling the pump support member and moving the pump support member in the opposite direction of assembly, the protruding portion comes into contact with the fuel pipe, thereby preventing the vibration-damping rubber from coming loose.

[0009] According to the third disclosure, the main body is provided with a bridging portion that straddles the notched groove.

[0010] According to the third disclosure, the bridging portion can suppress elastic deformation of the notched groove of the main body in the direction of expansion due to interference from the pump support member. This is effective in suppressing displacement of the vibration-damping rubber.

[0011] According to the fourth disclosure, the vapor separator tank comprises a tank body with an opening at the top and a lid that closes the opening at the top of the tank body. The tank body is the pump support member with the vibration-damping rubber interposed between it and the fuel pump.

[0012] According to the fourth disclosure, it is possible to suppress misalignment of the vibration-damping rubber and its subsequent detachment when assembling the tank body after attaching the vibration-damping rubber to the fuel pump.

[0013] This is a cross-sectional view showing a vapor separator according to one embodiment. This is a plan view of a fuel pump with a rubber cushion attached. This is a cross-sectional view taken along the line III-III in Figure 2. This is a cross-sectional view taken along the line IV-IV in Figure 2. This is an exploded perspective view of the fuel pump and rubber cushion. This is a top view of the rubber cushion. This is a bottom view of the rubber cushion. This is an exploded perspective view of the fuel piping of the fuel pump and fuel filter.

[0014] Embodiments for carrying out the technology disclosed herein will be described below with reference to the drawings. The vibration isolation structure of the fuel pump of this embodiment is applied to the vapor separator tank of a vapor separator for an outboard motor such as a motorboat. A vapor separator separates vapor (fuel vapor gas) from liquid fuel.

[0015] (Overview of the vapor separator) The vertical direction in Figure 1 corresponds to the vertical direction in the operating state of the vapor separator. As shown in Figure 1, the vapor separator 10 houses a float valve 18, a fuel pump 20, etc., within a vapor separator tank 12 that stores fuel. Various pipes, electrical wiring, etc., are connected to the vapor separator tank 12.

[0016] The vapor separator tank 12 comprises a cup-shaped tank body 14 with an open top and an inverted cup-shaped tank cover 16 that closes the top opening of the tank body 14. The tank body 14 and the tank cover 16 are joined by fastening means such as screws and snap-fits. The tank cover 16 corresponds to the "lid" as used herein.

[0017] The fuel pump 20 is a Wesco-type electric fuel pump with a cylindrical shape. The fuel pump 20 is positioned upright inside the vapor separator tank 12. The fuel pump 20 has a hollow cylindrical intake port 21 that protrudes from one end face (the lower end face) and draws in fuel. The intake port 21 is positioned eccentrically with respect to the axis of the fuel pump 20.

[0018] The fuel pump 20 has a hollow cylindrical discharge port 22 that protrudes from its other end face (upper end face) and discharges fuel. The discharge port 22 is fitted and connected to the fuel passage 16a of the tank cover 16. A cylindrical projection 23 protrudes from the lower end face of the fuel pump 20 (see Figure 8). The projection 23 is positioned eccentrically to the opposite side of the intake port 21 from the axis of the fuel pump 20.

[0019] A straight fuel pipe 25 is connected to the intake port 21, which is connected to the internal space of the bag-shaped filter material 24a of the fuel filter 24. At the tip of the fuel pipe 25, a bottomed cylindrical connection port 26 is formed, which has an axis perpendicular to its axis and has an open top.

[0020] Figure 8 shows the fuel pump inverted, with the intake port 21 facing upwards. As shown in Figure 8, a horizontal mounting piece 27 is formed on the outer surface of the connection port 26, projecting diagonally in the opposite direction from the fuel piping 25. A mounting hole 27a is formed in the mounting piece 27.

[0021] To attach the fuel filter 24 to the fuel pump 20, the connection port 26 is fitted into the intake port 21, the mounting hole 27a of the mounting piece 27 is fitted into the projection 23, and then the retaining washer 28 is attached to the projection 23 (see Figure 5).

[0022] As shown in Figure 1, an elastic, cap-shaped rubber cushion 30 is interposed between the fuel pump 20 and the tank body 14. The rubber cushion 30 is a component that dampens vibrations of the fuel pump 20 and is molded from a rubber-like elastic material made of resin. The tank body 14 corresponds to the "pump support member" as defined herein. The rubber cushion 30 corresponds to the "vibration-damping rubber" as defined herein. The rubber cushion 30 will be described in detail later.

[0023] (Installation of rubber cushion 30 on vapor separator tank 12) When installing the rubber cushion 30, the tank cover 16 is turned upside down, that is, with the opening facing upwards. The float valve 18, fuel pump 20, etc. are assembled to the tank cover 16. The discharge port 22 of the fuel pump 20 is fitted and connected to the fuel passage 16a of the tank cover 16. A fuel filter 24 is also pre-installed on the fuel pump 20.

[0024] In this state, after the rubber cushion 30 is attached to the fuel pump 20, the tank body 14 is connected to the tank cover 16. As a result, the rubber cushion 30 is interposed between the tank body 14 and the fuel pump 20. The completed vapor separator 10 is used upside down compared to when the rubber cushion 30 was attached (see Figure 1).

[0025] (Rubber cushion 30) Figures 2 to 4 show the state in which the rubber cushion 30 is attached to the fuel pump 20, that is, the state in which the intake port 21 of the fuel pump 20 is facing upward. The rubber cushion 30 will be explained based on the vertical direction in the state in which the rubber cushion 30 is attached to the fuel pump 20.

[0026] As shown in Figures 6 and 7, the rubber cushion 30 comprises a disc-shaped main body 31 and a cylindrical fitting portion 40 whose one end face (upper end face) is closed by the main body 31. The main body 31 has a U-shaped notch groove 32 (see Figure 5). The notch groove 32 is an opening groove that avoids the fuel pipe 25 (see Figures 2 to 4). On both opposing groove walls of the notch groove 32, concave portions 32a that form an arc shape in plan view are formed. The concave portions 32a abut or are close to the outer surface of the connection port 26 of the fuel pipe 25 in surface contact (see Figure 2). The main body 31 abuts the upper end face (the end face on the intake port 21 side) of the fuel pump 20 in surface contact.

[0027] Multiple body-side contact portions 33 (three shown in Figure 6) are formed intermittently along the periphery of the notched groove 32 and protrude from the upper surface of the main body portion 31. The upper end surfaces of the body-side contact portions 33 are in surface contact with the tank body 14. Of the three body-side contact portions 33, one is called body-side contact portion 33(a), and the remaining two are called body-side contact portions 33(b); otherwise, they are simply called body-side contact portions 33. Body-side contact portion 33(a) is formed in a semicircular shape along the inner end of the notched groove 32. Body-side contact portions 33(b) are formed along both sides of the notched groove 32.

[0028] The main body portion 31 is provided with a bridging portion 34 that straddles the notched groove 32 (see Figure 5). Both ends of the bridging portion 34 are connected to the ends of the main body side contact portions 33(b) that are not on the opening side. The bridging portion 34 is formed in a curved shape so as to contact or be in close proximity to the outer surface of the connection port 26 of the fuel pipe 25 (see Figure 2).

[0029] The fitting portion 40 is formed in a cylindrical shape that can be fitted onto the fuel pump 20 (specifically the axial end) (see Figure 4). The fitting portion 40 has a split groove 41 that is continuous with the notched groove 32 of the main body portion 31. When fitting the fitting portion 40 onto the fuel pump 20, the fuel pipe 25 can be passed along the split groove 41 (from bottom to top in Figure 4).

[0030] As shown in Figure 4, a pair of strip-shaped protruding pieces 42 that reduce the groove width are formed on both groove walls of the split groove 41 of the fitting portion 40. The protruding pieces 42 are positioned in the axial middle part of the fitting portion 40. The protruding pieces 42 are formed in an arc shape that follows the outer surface of the fuel pump 20 (see Figure 2). The protruding lengths of the two protruding pieces 42 are different. In addition, the lower edges 42a of both protruding pieces 42 are inclined surfaces that slope upward from the base end to the tip end. The protruding pieces 42 correspond to the "protruding portion" as referred to in this specification.

[0031] (Attachment of the rubber cushion 30 to the fuel pump 20) When attaching the rubber cushion 30 to the fuel pump 20 from the state shown in Figure 5, the fitting part 40 is fitted to the fuel pump 20 so that the fuel pipe 25 passes through the split groove 41 of the fitting part 40, thereby positioning the fuel pipe 25 within the notched groove 32 of the main body part 31 (see Figure 4). Also, as the fuel pipe 25 passes along the split groove 41, the protruding pieces 42 elastically deform, allowing the passage of the fuel pipe 25. After the passage of the fuel pipe 25, the protruding pieces 42 return to their original state by elastic recovery.

[0032] (Advantages of this embodiment) According to this embodiment, by fitting the fitting portion 40 of the rubber cushion 30 to the fuel pump 20, it is possible to suppress misalignment of the rubber cushion 30 and detachment due to such misalignment that occurs when assembling the tank body 14 (including reassembly). In turn, the ease of assembling the tank body 14 can be improved.

[0033] Furthermore, by fitting the fitting portion 40 to the fuel pump 20, it is possible to suppress misalignment of the rubber cushion 30 in the direction of dislodgement and detachment due to such misalignment when the tank body 14 is moved in the opposite direction of assembly (upward) when the tank body 14 is reassembled.

[0034] Furthermore, when passing the fuel pipe 25 of the fuel filter 24 along the split groove 41 of the fitting portion 40, the protruding pieces 42 elastically deform, allowing the passage of the fuel pipe 25. Also, when reassembling the tank body 14 and moving the tank body 14 in the opposite direction of assembly (upward), the protruding pieces 42 come into contact with the fuel pipe 25, further suppressing the rubber cushion 30 from coming off.

[0035] Furthermore, the upper edges of both protruding pieces 42 are in a plane perpendicular to the axis of the fitting portion 40, and the fuel pipe 25 has a D-shaped cross-section, with its plane (bottom surface) facing parallel to the upper edges of both protruding pieces 42. Therefore, the rubber cushion 30 can be effectively prevented from coming loose.

[0036] Furthermore, since the lower edges 42a of both protruding pieces 42 are inclined surfaces and the upper surface of the fuel pipe 25 has a semicircular cross-section, both protruding pieces 42 can be easily elastically deformed when passing the fuel pipe 25 along the split groove 41 of the fitting portion 40.

[0037] Furthermore, the bridging portion 34 can suppress elastic deformation of the notched groove 32 of the main body portion 31 in the expanding direction due to interference with the tank body 14. This is effective in suppressing displacement of the rubber cushion 30. In addition, since the bridging portion 34 is positioned to straddle the base end of the mounting piece 27 of the fuel pipe 25 and a part of the retaining washer 28, it can suppress the detachment of the fuel pipe 25 from the fuel pump 20 due to vibrations of the outboard motor, etc.

[0038] Furthermore, the vapor separator tank 12 can suppress misalignment of the rubber cushion 30 and its subsequent detachment when assembling the tank body 14 (including reassembly) after attaching the rubber cushion 30 to the fuel pump 20.

[0039] [Other Embodiments] The technology disclosed herein is not limited to the embodiments described above, and can be implemented in various other forms. For example, the technology disclosed herein may be applied not only to the vapor separator tank 12, but also to a vibration-damping structure for the support structure of the fuel pump 20. The pump support member may be a member other than the tank body 14. At least one of the pair of overhanging pieces 42 and / or the bridging portion 34 may be omitted. The number of body-side contact portions 33 may be increased or decreased as appropriate.

Claims

1. A vibration-damping structure for a fuel pump, comprising: a fuel pump; a pump support member for supporting the fuel pump; and a vibration-damping rubber interposed between the fuel pump and the pump support member to dampen vibrations of the fuel pump, wherein the vibration-damping rubber comprises: a main body portion having a notched groove to avoid fuel piping of a fuel filter connected to the fuel pump; and a fitting portion having a split groove continuous with the notched groove and fitting onto the fuel pump.

2. A vibration-damping structure for a fuel pump according to claim 1, wherein the groove wall surface of the split groove is provided with an overhang that reduces the groove width.

3. A vibration-damping structure for a fuel pump according to claim 1, wherein the main body portion is provided with a bridging portion that straddles the notched groove.

4. A vapor separator tank having a vibration-damping structure for a fuel pump as described in any one of claims 1 to 3, comprising a tank body having an open top surface and a lid that closes the top opening of the tank body, wherein the tank body is the pump support member with the vibration-damping rubber interposed between it and the fuel pump.

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