JP2011026962A - Fuel feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel feeder capable of reducing the number of fuel flow pipes required for delivering and receiving fuel when mounted to a vehicle body, and capable of avoiding a vapor lock. <P>SOLUTION: The fuel feeder 10A includes a housing 11 in which a high-pressure fuel passage 17 is formed, a fuel pump 30, and a pressure regulating device 70 which comprises a relief port 71c for feeding fuel in the high-pressure fuel passage 17 to the outside of the high-pressure fuel passage 17 and regulates pressure in the high-pressure fuel passage 17. The housing 11 includes a housing body 11A having a supply port 15B and a tank insertion part 11B which integrally projects from the housing body 11A and in which a suction port 24B and a discharge port 24d are formed. A return passage 60A is formed in the housing 11 so as to make the pressure regulating device 70 communicate with the discharge port 24d. The tank insertion part 11B is inserted into the fuel tank 2, and the housing 11 is attached directly to the fuel tank 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel supply device having a built-in pressure adjusting device for adjusting the pressure of fuel supplied to an engine such as a small motorcycle.

  Due to environmental problems such as global warming, regulations on fuel consumption and exhaust gas for gasoline engines are becoming stricter. In recent years, regulations on small displacement engines such as small two-wheeled vehicles are also being enforced. Against this background, fuel supply systems for engines of four-wheeled vehicles and two-wheeled vehicles are replaced by conventional mechanical systems using carburetors. In order to reduce the fuel consumption of the engine and clean the exhaust gas, electronic control, that is, FI (Fuel Injection) is required.

An in-tank type fuel supply device installed in a fuel tank is employed in automobiles, medium and large-sized motorcycles, and the like. However, in the case of an engine with a small displacement, the capacity of the fuel tank is small. Therefore, in order to mount the in-tank type fuel supply device, it is necessary to significantly review the layout of the fuel tank. Therefore, in order to make the small displacement engine FI, an in-line type fuel supply device that can be mounted on a piping path between the fuel tank and the engine is required.
Here, the fuel supply device generally has a pressure regulator for supplying a stable fuel pressure to the engine.
And if the pressure regulator is mounted separately from the inline fuel supply device, the mounting space will be large, so the inline fuel supply device has a built-in pressure regulator for the purpose of reducing the mounting space. A conventional fuel pump device has been proposed (see, for example, Patent Document 1).

  The conventional fuel pump device includes a first fuel chamber having an inflow port into which fuel from a fuel tank is introduced, a fuel chamber partitioned into a second fuel chamber having a fuel supply port, and a main portion of the first fuel chamber. And a fuel pump that is disposed in the two fuel chambers and pressurizes the fuel sucked from the suction portion inserted into the first fuel chamber and discharges the fuel from the discharge hole connected to the supply port. Further, the conventional fuel pump device is provided in a fuel discharge passage that opens into the second fuel chamber, and a regulator passage that has an upstream end that opens to the supply port and a downstream end that opens to the second fuel passage, and flows through the supply port. A pressure control valve as a pressure regulator that adjusts the pressure of the fuel flowing through the supply port by allowing the regulator passage and the second fuel chamber to communicate with each other when the pressure of the fuel exceeds a certain pressure; Have

  When the conventional fuel pump device configured as described above is mounted in-line between the fuel tank and the engine, the suction pipe that connects the fuel tank and the inlet of the fuel chamber, and the supply port and the engine are connected. In addition to the discharge pipe to be connected, a discharge pipe for connecting the fuel discharge path and the fuel tank is required. In other words, when a conventional fuel pump is mounted in-line, three fuel flow path tubes, that is, a suction pipe, a discharge pipe, and a discharge pipe are required, so that the piping layout of the fuel flow path pipe is complicated. Further, in a small two-wheeled vehicle, a space for mounting a conventional fuel pump device is small, and a fuel flow path pipe having a complicated piping layout must be stored in a small space. It is not easy to design a complicated piping layout and bend the fuel flow path pipe to fit in a small space, and there is a problem that the cost for mounting the conventional fuel pump device on a small two-wheeled vehicle increases.

In view of the above problems, there has been proposed a conventional fuel supply apparatus that can be mounted inline between a fuel tank and an engine while omitting a discharge pipe.
A conventional fuel supply apparatus includes a housing provided with a suction port and a supply port, a fuel reservoir chamber provided in the housing and connected to the suction port, a fuel reservoir chamber provided in the housing, and discharging fuel in the fuel reservoir chamber. A pump, a high-pressure passage provided in the housing, connected to the supply port and discharged from the fuel pressurized by the pump, and provided in the housing, when the pressure in the high-pressure passage exceeds a predetermined value And a pressure regulator for adjusting the pressure in the high-pressure passage by communicating between the high-pressure passage and the fuel reservoir (see, for example, Patent Document 2).
In the conventional fuel supply device, the fuel discharged from the pressure regulator is configured to be guided to the fuel reservoir chamber in the housing. Therefore, when the conventional fuel supply device is mounted on the vehicle body, the conventional fuel pump There is no need to provide a discharge pipe as in the apparatus. As a result, the complexity of the layout of the fuel flow pipe has been reduced.

JP-A-11-303704 JP 2008-255846 A

  However, since the distance between the engine and the fuel tank is short as in a small motorcycle and the space for mounting the pump is limited, the pump is located near the engine when the conventional fuel supply device is mounted on the body of a small motorcycle. Will be placed. When the engine is stopped after warming up, or when the cooling effect of the engine cannot be expected due to running wind, fuel vapor (vapor bubbles) is likely to be generated especially in the low-pressure pipe due to heat from the engine. . Further, in the pressure adjusting device, the fuel on the high pressure fuel passage side is suddenly decompressed and discharged into the fuel reservoir chamber. However, vapor is likely to occur even when the fuel pressure is suddenly decompressed. Are known. That is, the vapor is likely to be generated in the fuel passing through the pressure adjusting device. When the fuel containing the vapor discharged into the high-pressure fuel passage is returned to the fuel reservoir chamber again via the pressure regulator as in the conventional fuel supply device, a large amount of vapor is accumulated in the fuel reservoir chamber. There was a problem that vapor lock occurred in the pump.

  The present invention has been made to solve the above-described problems, and enables the piping layout to be simplified by reducing the number of fuel passage pipes required for delivery of fuel when mounted on the vehicle body, It is an object of the present invention to provide a fuel supply device that can avoid the occurrence of vapor lock.

  The present invention has a suction port and a supply port, and is formed with a fuel reservoir chamber connected to the suction port, a high-pressure fuel passage connected to the supply port, and a pressure adjusting device insertion hole connected to the high-pressure fuel passage. A housing, a fuel pump that pressurizes fuel in the fuel reservoir chamber and discharges the fuel into a high-pressure fuel passage, and a high-pressure fuel passage when the pressure in the high-pressure fuel passage exceeds a predetermined pressure. A fuel supply device comprising: a pressure adjusting device that has a relief port for sending the fuel inside the high pressure fuel passage to the outside and adjusts the pressure in the high pressure fuel passage to a predetermined pressure. The housing has a supply port The main body of the housing and the tank main body that protrudes integrally with the main body of the housing and has a suction port and a discharge port are formed. Is formed in the housing so as to communicate with the discharge port, the tank insertion portion is inserted into the fuel tank, the housing is directly attached to the fuel tank, and the fuel pump pressurizes the fuel in the fuel tank to a predetermined pressure. Discharging from the supply port.

According to the fuel supply device of the present invention, the tank insertion portion in which the intake port and the discharge port are formed is inserted into the fuel tank so that the housing can be directly attached to the fuel tank. And a return path communicating with the discharge port.
Therefore, the low pressure pipe connecting the intake port and the inside of the fuel tank and the exhaust pipe connecting the exhaust port and the inside of the fuel tank can be omitted, and can be mounted on the vehicle body without complicating the piping layout. Thereby, the cost concerning mounting to a vehicle body of a fuel supply device can be reduced. In addition, the fuel sent out from the relief port of the pressure regulator is discharged directly into the fuel tank via the return path, so that the vapor is sequentially discharged without accumulating in the fuel reservoir chamber, and the vapor lock is activated by the fuel pump. It can be avoided.

It is a block diagram of a fuel supply system provided with the fuel supply apparatus which concerns on Embodiment 1 of this invention. It is a partially broken sectional view of the fuel supply apparatus according to Embodiment 1 of the present invention. It is a top view of the fuel supply apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is an enlarged view of a main part around the valve unit in FIG. 2, showing a state in which a suction valve body is closed and a discharge valve body is opened. FIG. 3 is an enlarged view around a pressure adjusting device in FIG. 2. FIG. 3 is an enlarged view of the periphery of a cylinder and a piston in FIG. 2, showing a state where the piston is at top dead center. FIG. 2 is an enlarged view of the periphery of a cylinder and a piston according to the first embodiment of the present invention, showing a state where the piston is at bottom dead center. It is a perspective view of the bush of the fuel supply apparatus which concerns on Embodiment 1 of this invention. It is a principal part enlarged view of the valve unit periphery of the fuel supply apparatus which concerns on Embodiment 1 of this invention, and the state which the intake valve body opened and the discharge valve body was closed is shown. It is a partially broken sectional view of the fuel supply apparatus which concerns on Embodiment 2 of this invention. It is an enlarged view of the pressure regulator periphery of FIG. It is the side view which saw through the inside of a fuel tank in the state where the fuel supply apparatus which concerns on Embodiment 3 of this invention was attached to the fuel tank. It is principal part sectional drawing around the discharge port of the fuel supply apparatus which concerns on Embodiment 4 of this invention, and the discharge port valve has shown the state which open | released the obstruction | occlusion of the discharge port. It is principal part sectional drawing of the surroundings of the discharge port of the fuel supply apparatus which concerns on Embodiment 4 of this invention, The discharge port valve has shown the state which plugged up the discharge port.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

Embodiment 1 FIG.
1 is a configuration diagram of a fuel supply system including a fuel supply apparatus according to Embodiment 1 of the present invention, FIG. 2 is a partially cutaway sectional view of the fuel supply apparatus according to Embodiment 1 of the present invention, and FIG. 4 is a top view of the fuel supply device according to the first embodiment of the invention, and FIG. 4 is an enlarged view of a main part around the valve unit of FIG. 2, showing a state where the intake valve body is closed and the discharge valve body is opened. . 5 is an enlarged view of the periphery of the pressure adjusting device of FIG. 2, and FIG. 6 is an enlarged view of the periphery of the cylinder and piston of FIG. 2, showing a state where the piston is at top dead center. FIG. 7 is an enlarged view around the cylinder and the piston according to the first embodiment of the present invention, and shows a state where the piston is at the bottom dead center. FIG. 8 is a perspective view of the bush of the fuel supply device according to Embodiment 1 of the present invention, and FIG. 9 is an enlarged view of a main part around the valve unit of the fuel supply device according to Embodiment 1 of the present invention. The body is opened and the discharge valve body is closed.

A main configuration of the fuel supply system 1 will be described.
In FIG. 1, a fuel supply system 1 is connected to a fuel tank 2, a fuel supply device 10 </ b> A directly attached to the outer surface of the fuel tank 2, and a fuel supply device 10 </ b> A via a high-pressure pipe 4. A fuel injection valve 6 for injecting the supplied fuel into a fuel chamber of an engine (not shown), a drive control for controlling the fuel supply from the fuel supply device 10A to the fuel injection valve 6 and the fuel injection timing from the fuel injection valve 6 Part 7.

The fuel supply device 10A includes a housing main body 11A having a supply port 15B connected to the high-pressure pipe 4, and a tank insertion portion 11B having a suction port 24B and a discharge port 24d that are integrally provided on the housing main body 11A. A fuel pump 30 which is installed in the housing 11 and pressurizes the fuel taken in from the suction port 24B to a high pressure and discharges it from the supply port 15B. Pressure adjusting device 70 for adjusting the fuel pressure of the fuel to a predetermined value, a return path 60A from the relief port 71c to the discharge port 24d of the pressure adjusting device 70, and a fuel attached to the suction port 24B and sucked from the suction port 24B And a filter 68a for removing impurities.
The drive control unit 7 controls the supply of fuel to the fuel injection valve 6 by performing drive control of the fuel pump 30.

Next, details of the fuel supply device 10A will be described with reference to FIG.
First, the housing 11 will be described.
The housing main body 11A is constituted by a body main body 12A, a second body 15 and a third body 21 constituting the first body 12 described below, and the tank insertion part 11B is described below. It is comprised by the fuel delivery part 12B of 1 body part 12, and the adapter 23A.

The first body portion 12 includes a cylindrical body main body portion 12A and a cylindrical fuel delivery portion 12B protruding from the outer peripheral surface of the body main body portion 12A.
The second body portion 15 includes a columnar fitting projection 15A fitted inside the one end side of the body main body portion 12A, and a supply port 15B protruding from one surface of the fitting projection 15A.

  The fitting protrusion 15A is formed with a holding valve arrangement hole 16 that opens to the other surface. Further, the fitting protrusion 15A has a high pressure fuel passage 17 extending from the holding valve arrangement hole 16 to the supply port 15a of the supply port 15B, a branch high pressure fuel passage 18 branched from the high pressure fuel passage 17, and a branch high pressure fuel passage. A drain hole 19 is formed from the branch end side portion of 18 to the other surface of the fitting projection 15A. At this time, the hole directions of the holding valve disposing hole 16 and the drain hole 19 coincide with the axial direction of the fitting protrusion 15A.

The third body portion 21 has a bottomed cylindrical shape, is fitted from the opening side to the other end side of the body main body portion 12A, and a shaft hole (not shown) is provided coaxially at the bottom portion.
As described above, the housing main body 11 </ b> A is configured by integrating the body main body 12 </ b> A, the second body 15, and the third body 21.

Further, the adapter 23A has a disk shape, and is provided on the other surface of the closing portion 24A and the closing portion 24A connected to the fuel passing portion 12B so as to cover the opening of the fuel passing portion 12B on one surface thereof. A suction port 24B is provided. The fuel introduction hole 25 is formed so as to penetrate from the suction port 24a of the suction port 24B through the plug portion 24A to one surface of the plug portion 24A. A circular recess 24b is formed on one surface of the closing portion 24A. A return hole 24c is formed so as to penetrate a portion of the closing portion 24A corresponding to the recess 24b in the axial direction of the closing portion 24A. Hereinafter, the opening of the return hole 24c on the other surface side of the closing portion 24A is referred to as a discharge port 24d. The adapter 23A and the fuel delivery part 12B are connected so that the peripheral edge on the one surface side of the adapter 23A and the end face on the protruding side of the fuel delivery part 12B are opposed to each other via the seal member 27.
As described above, the tank insertion portion 11B is configured by integrating the adapter 23A and the fuel delivery portion 12B.

  Further, as shown in FIG. 3, the mounting flange 29 extends from a portion around the fuel delivery portion 12B in a direction approximately perpendicular to the axial direction of the fuel delivery portion 12B. The attachment flange 29 is used for attaching the fuel supply device 10A to the fuel tank 2 of the vehicle body.

The fuel pump 30 is a positive displacement axial piston pump similar to that disclosed in Japanese Patent Laid-Open No. 2008-255846.
Hereinafter, the main configuration of the fuel pump 30 will be described.
In FIG. 2, the fuel pump 30 is inserted into the housing 11 from the shaft hole at the bottom of the third body portion 21 and is rotatably supported by the third body portion 21 via a bearing (not shown). And a swash plate 32 connected to one end of the shaft 31, and a motor 33 for rotating the shaft 31 about its axis. The fuel pump 30 is fitted coaxially to the body main body 12A between the fitting protrusion 15A and the swash plate 32, and is slidable in the cylinder 41 having a cylindrical shape and a cylinder block 40A having a cylinder 41. The piston 47 is disposed, and the valve unit 50 is disposed between the cylinder block 40A and the fitting protrusion 15A. The axial direction of the shaft 31 and the body main body portion 12A are the same.

  A plurality of cylinders 41 are formed in the cylinder block 40A at equiangular pitches on a concentric circle with the hole direction aligned with the axial direction. In FIG. 2, only one cylinder 41 is shown. Further, a plurality of suction holes 42 parallel to the cylinder 41 are formed in the cylinder block 40 </ b> A so as to correspond one-to-one with each of the cylinders 41.

  The fuel reservoir chamber 13 connected to the suction port 24a is formed in a region surrounded by the tank insertion portion 11B, the valve unit 50, and the third body portion 21.

  As shown in FIGS. 4 and 5, the valve unit 50 includes a plate 51, and a suction valve plate 52 and a discharge valve plate 53 that are arranged so as to sandwich the plate 51. The valve unit 50 is fitted into the inner peripheral surface of the body main body 12A with the intake valve plate 52 facing the cylinder block 40A. At this time, as shown in FIG. 2, the cylinder block 40 </ b> A and the valve unit 50 are arranged so as to block the passage from the opening of the fuel delivery part 12 </ b> B to the fitting protrusion 15 </ b> A.

As shown in FIG. 4, the plate 51 has a suction groove 51 a that is recessed on the surface facing the cylinder block 40 </ b> A and the suction valve plate 52 so as to communicate the cylinder 41 and the suction hole 42. 41 has a discharge hole 51b drilled in a portion opposite to 41.
The suction valve plate 52 has a suction valve body 52a configured at a position facing the suction hole 42, and a cylinder connection hole 52b formed so as to communicate the cylinder 41 and the suction groove 51a. .

  The discharge valve plate 53 has a discharge valve body 53a disposed at a position facing the discharge hole 51b. The discharge groove 53b is formed in the fitting protrusion 15A so as to reach the holding valve disposing hole 16 from the portion of the fitting protrusion 15A facing the discharge valve body 53a.

  The suction valve body 52a contacts and separates from the end face of the cylinder block 40A according to the pressure difference between the pressure increasing chamber 55 and the suction hole 42 described below, and opens and closes the suction hole 42. The pressure increasing chamber 55 is a space defined by the piston 47 and the cylinder 41, a space including the suction groove 51a, the discharge hole 51b, and the cylinder connection hole 52b.

  Further, the discharge valve body 53a opens and closes the discharge hole 51b by making contact with and separating from the end surface of the plate 51 according to the pressure difference between the pressure increasing chamber 55 and the discharge groove 53b.

  Moreover, the swash plate 32 is comprised by the inclined surface in which the one surface was inclined with respect to the other surface. The swash plate 32 is fixed to one end of the shaft 31 such that the other surface is orthogonal to the axial direction of the shaft 31 and the inclined surface is opposed to the cylinder block 40A.

  Further, as shown in FIG. 6, one end side of the piston 47 is inserted into the cylinder 41 and is slidable along the hole direction of the cylinder 41. A piston urging spring 49 is disposed between the piston 47 and the cylinder block 40 </ b> A, and the urging force of the piston urging spring 49 acts in the direction of extracting the piston 47 from the cylinder 41. Thus, the other end side of the piston 47 is in contact with the inclined surface of the swash plate 32 in a pressed state.

  When the swash plate 32 rotates in conjunction with the rotation around the axis of the shaft 31, each piston 47 has a top dead center where the piston 47 is inserted into the cylinder 41 as shown in FIG. The piston 47 reciprocates between the bottom dead center that protrudes most from the cylinder 41.

Next, the pressure adjusting device 70 will be described.
As shown in FIG. 5, the pressure adjusting device 70 has a pressure adjusting device insertion hole 65a formed by coaxially connecting the drain hole 19 and a through hole 66A formed through the valve unit 50 and the cylinder block 40A. It is arranged. At this time, the pressure adjusting device insertion hole 65 a is connected to the high pressure fuel passage 17 via the branch high pressure fuel passage 18. The diameter of the through hole 66A is smaller than the diameter of the drain hole 19 in a step shape.

The pressure adjusting device 70 is disposed in the casing 71 and a cylindrical casing 71 disposed coaxially with the pressure adjusting device insertion hole 65a with one axial end of the pressure adjusting device 70 directed toward the branch high-pressure fuel passage 18. A poppet valve 80 is provided.
Hereinafter, one end and the other end of the casing 71 in the axial direction are simply referred to as one end and the other end.

  The poppet valve 80 includes a cylindrical valve seat 82 in which one end side opening is coaxially pressed and fixed toward the branch high-pressure fuel passage 18 inside the casing 71 in the axial direction, and the other end of the valve seat 82. The valve seat 82 and the sliding member 83 can be seated on the other end of the sliding member 83 and the valve seat 82 which are arranged coaxially with the casing 71 so as to be slidable in the axial direction of the casing 71 on the side. And a urging means for urging the valve body 85 in the direction in which the valve body 85 is seated on the valve seat 82, and the valve body 85 closing the opening on the other end side of the valve seat 82 when seated on the valve seat 82. The spring 87 is provided. Hereinafter, the opening on the other end side of the valve seat 82 is referred to as a valve port 82a. The opening on the other end side of the casing 71 is a relief port 71 c of the pressure adjusting device 70.

And the casing 71 has a pair of flange parts 71a and 71b which protrude in the radial direction from the outer peripheral surface at a predetermined interval in the axial direction on one end side thereof.
At this time, the outer diameter of the flange portions 71a and 71b is larger than the diameter of the through hole 66A, and the outer diameter of the casing 71 excluding the flange portions 71a and 71b is slightly smaller than the diameter of the through hole 66A.
The casing 71 is disposed coaxially with the pressure adjusting device insertion hole 65a so that the flange portions 71a and 71b are disposed in the drain hole 19 and the other end portion of the casing 71 is disposed in the through hole 66A. Yes.

  Further, an annular seal member 73 is mounted on the casing 71 between the flange portions 71 a and 71 b so as to be fitted onto the casing 71, and the seal member 73 is in close contact with the inner wall of the drain hole 19.

  The sliding member 83 is formed in a cylindrical shape having an outer diameter on one end side smaller than that on the other end side. Two cylindrical inflow holes 83 a serving as communication passages communicating between the inside and outside of one end side in the axial direction of the sliding member 83 are formed at a 180 ° equiangular pitch in the circumferential direction of the sliding member 83. The sliding member 83 is slidable in the casing 71 in the axial direction of the casing 71 while the outer peripheral surface on the large diameter side is in sliding contact with the inner peripheral surface of the casing 71.

  Further, a fuel flow path 84 is formed in the casing 71 so as to reach the sliding member 83 from the valve port 82a of the valve seat 82 through the cylindrical portion inflow hole 83a.

  The valve body 85 has a spherical shape, and is disposed between the valve seat 82 and the sliding member 83 as described above. Further, the spring 87 is contracted between the other end of the casing 71 and the other end of the sliding member 83, and presses the valve body 85 with a predetermined pressure in a direction in which the valve body 85 is seated on the valve seat 82. When the valve body 85 is seated on the valve seat 82, the valve body 85 comes into contact with the entire circumferential direction of the valve port 82a to close the valve port 82a.

  When the pressure that pushes the valve body 85 from the branch high-pressure fuel passage 18 side, which has substantially the same pressure as the high-pressure fuel passage 17, is equal to or less than a predetermined value, the valve body 85 and the valve seat 82 are Each of the sliding members 83 is held in contact with the pressed state. When the pressure pushing the valve body 85 from the branch high-pressure fuel passage 18 side becomes larger than a predetermined value, the valve body 85 is displaced so as to open the valve port 82 a against the urging force of the spring 87.

Next, the return path 60A will be described.
The return path 60 </ b> A is configured by a return path constituent member 60. The return path constituting member 60 includes a return path forming block 61B of the bush 61 disposed between the cylinder block 40A and the third body portion 21, a return pipe 62 connected to the bush 61, and an adapter 23A. Has been.
As shown in FIG. 8, the bush 61 includes a cylindrical base 61A in which rectangular fuel passage openings 61a are formed at a predetermined pitch in the circumferential direction, and a return path protruding in the radial direction from the inner peripheral surface of the base 61A. Forming block 61B.
A fuel discharge hole 61b is formed through the return path forming block 61B. At this time, one end side of the fuel discharge hole 61b is opened so as to face one side in the axial direction of the base 61A inside the base 61A in the radial direction, and the other end of the fuel discharge hole 61b is the outer peripheral side of the base 61A. The base 61A is opened so as to face the outside in the radial direction. The fuel discharge hole 61b is separated from the fuel passage port 61a. Hereinafter, the opening on the one end side and the opening on the other end side of the fuel discharge hole 61b are referred to as an inflow side opening 61c and an outflow side opening 61d.

  As shown in FIGS. 2 and 5, the bush 61 aligns the axial direction of the base 61 </ b> A with the axial direction of the body main body 12 </ b> A, and the inflow side opening 61 c is liquid-tightly connected to the relief port 71 c of the casing 71. It is fixed between the cylinder block 40A and the opening side end surface of the third body portion 21 so as to be connected while maintaining the property and airtightness. At this time, the outflow side opening 61d is opposed to the opening of the fuel delivery part 12B. In addition, a path is secured from the fuel delivery part 12B through the fuel passage port 61a of the bush 61 to the suction hole of the cylinder block 40A.

  As shown in FIG. 2, the return pipe 62 has one end inserted into the outflow opening 61d and the other end inserted into the recess 24b of the closing portion 24A. 61B is connected. At this time, the return pipe 62 and the recess 24b, and the return pipe 62 and the return path forming block 61B are connected while maintaining liquid tightness and air tightness. Thereby, in the fuel reservoir chamber 13, the fuel in the fuel reservoir chamber 13 and the fuel in the return path 60A are separated without mixing. The return path 60A is configured by a path from the relief port 71c of the pressure adjusting device 70 to the discharge port 24d of the return hole 24c that opens to the adapter 23A.

  Further, as shown in FIGS. 2 and 3, the filter 68a is formed in a rectangular flat plate shape, and is attached to the end of the suction port 24B so as to cover the suction port 24a. The filter 68a extends around the suction port 24B and is opposed to the discharge port 24d.

  The hole shape of the return path constituting member 60 constituting the return path 60A is such that the fuel is returned to the return path by pressure loss when the fuel passes through the suction path from the filter 68a to the fuel reservoir chamber 13 via the suction port 24B. The pressure loss when passing through 60A is set to be larger.

Here, the pressure loss when the fuel passes through the path from the valve outlet 82a of the pressure regulator 70 to the relief port 71c of the casing 71, in other words, the fuel regulates the pressure inside the pressure regulator 70. The pressure loss when it flows to the relief port 71c of the casing 71 after that is defined as the pressure loss of the pressure adjusting device 70 after pressure adjustment. The hole shape of the return path component 60 is set so that the pressure loss when the fuel passes through the return path 60A is smaller than the pressure loss of the pressure adjusting device 70 after pressure adjustment.
In summary, the pressure loss when the fuel passes through the suction path <the pressure loss when the fuel passes through the return path 60A <the pressure loss until the fuel is sent out from the pressure regulator 70 after the pressure adjustment, and It has become.

Next, a structure for attaching the fuel supply device 10A to the fuel tank 2 will be described.
In FIG. 2, a mounting hole 2 a is formed in the lower part of the fuel tank 2. The fuel supply device 10A is attached to the fuel tank 2 via a mounted body 90 described below.
The mounted body 90 is formed in a cylindrical shape and has a flange portion 90a that extends radially outward from one end in the axial direction. The mounted body 90 is inserted into the fuel tank 2 from the other end side, and is mounted on the fuel tank 2 so that the flange portion 90a is in close contact with the outer surface of the fuel tank 2. Note that the mounted body 90 is mounted on the fuel tank 2 so that the liquid-tightness and air-tightness inside and outside the fuel tank 2 are maintained.

The fuel supply device 10A then attaches the adapter 23A to the fuel delivery part 12B, and further attaches the filter 68a to the suction port 24B, and then inserts the tank insertion part 11B into the fuel tank 2 and attaches the fuel delivery part 12B. By fitting in the body 90, it is directly attached to the fuel tank 2 via the mounted body 90.
At this time, the axial direction of the body body portion 12A of the first body portion 12 coincides with the substantially horizontal direction, and the filter 68a is disposed so as to cover the discharge port 24d when viewed from above in the vertical direction. Further, the seal member 27 between the one end surface of the fuel delivery portion 12B and the outer peripheral edge portion of the adapter 23A is in close contact with the inner peripheral surface of the mounted body 90, and the fuel in the fuel tank 2 is transferred to the mounted body. There is no leakage outside the fuel tank 2 between 90 and the fuel delivery part 12B.

  The motor 33 is integrally attached to the housing 11 in advance. And although not shown in figure, the above-mentioned high-pressure pipe 4 which connects the edge part of the supply port 15B and the fuel injection valve 6 is piped, and the fuel supply system 1 is comprised.

Next, the operation of the fuel supply system 1 configured as described above will be described.
First, the fuel supply operation to the fuel injection valve 6 will be described.
When the swash plate 32 rotates in conjunction with the rotation of the shaft 31 by the motor 33, each piston 47 has a top dead center shown in FIG. 6 and a bottom dead center shown in FIG. 7 according to the rotation angle of the swash plate. Move back and forth between points.

  When the piston 47 goes to the position of the bottom dead center, the inside of the pressure increasing chamber 55 is depressurized, and when the piston 47 goes to the top dead center, the inside of the pressure increasing chamber 55 is increased.

  Then, when the pressure in the pressure increasing chamber 55 becomes higher than the pressure in the fuel reservoir chamber 13 while the piston 47 is displaced in the direction from the bottom dead center toward the top dead center, as shown in FIG. 52 a is displaced toward the cylinder block 40 </ b> A and closes the suction hole 42. Further, when the pressure in the pressure increasing chamber 55 becomes larger than a predetermined value, the discharge valve body 53a is displaced to the bottom side of the discharge groove 53b and the discharge hole 51b is opened. As a result, high-pressure fuel is discharged to the high-pressure fuel passage 17 via the discharge groove 53 b and the fuel pressure holding valve 9, and further supplied to the fuel injection valve 6 via the high-pressure pipe 4.

  Next, when the piston 47 is displaced in the direction from the bottom dead center to the top dead center and the pressure in the pressure increasing chamber 55 becomes a predetermined value or less, as shown in FIG. 9, the discharge valve body 53a is inserted into the discharge hole 51b. When the opening is closed and the discharge of fuel into the high-pressure fuel passage 17 is stopped and the pressure in the pressure increasing chamber 55 becomes lower than the pressure in the fuel reservoir chamber 13, the suction valve body 52 a is moved to the bottom side of the suction groove 44. The suction hole 42 is opened, and the fuel is supplied into the pressure increasing chamber 55.

Next, fuel pressure adjustment to the fuel injection valve 6 by the pressure adjusting device 70 will be described.
In the initial state, it is assumed that the pressure in the high-pressure fuel passage 17 is smaller than a predetermined value, and the valve body 85 closes the valve port 82a.
The fuel pressure in the drain hole 19 connected to the high pressure fuel passage 17 via the branch high pressure fuel passage 18 is substantially the same as that of the high pressure fuel passage 17.

  In FIG. 2, when the pressure in the high-pressure fuel passage 17 becomes larger than a predetermined value, the valve body 85 is displaced so as to release the closing of the valve port 82a against the urging force of the spring 87. That is, when the fuel pressure in the high pressure fuel passage 17 becomes larger than a predetermined value, the differential pressure between the fuel in the high pressure fuel passage 17 and the fuel in the return path 60A communicating with the fuel tank 2 becomes larger than the urging force of the spring 87. Then, the valve body 85 is displaced against the urging force of the spring 87, and the closing of the valve port 82a is released. Then, the fuel on the high pressure fuel passage 17 side is discharged from the valve port 82a.

The fuel discharged from the valve port 82a is guided to the relief port 71c through the inside of the sliding member 83. Next, the fuel flows through the return path 60A constituted by the fuel discharge hole 61b of the return path forming block 61B, the return pipe 62, and the return hole 24c of the adapter 23A, and is discharged into the fuel tank 2 from the discharge port 24d. .
As described above, the fuel discharged from the high-pressure fuel passage 17 to the pressure adjusting device 70 via the branch high-pressure fuel passage 18 is returned to the fuel tank 2 without being returned to the fuel reservoir chamber 13.

For this reason, even if vapor is generated in the fuel in the fuel reservoir 13 and the fuel containing the vapor is discharged to the high-pressure fuel passage 17, it is sent to the fuel injection valve 6 and discharged, or the pressure adjusting device 70, it is returned into the fuel tank 2 via the return path 60A.
As described above, since the fuel sent out from the pressure adjusting device 70 is not returned to the fuel reservoir chamber 13, it occurs when passing through the vapor previously generated in the fuel in the fuel reservoir chamber 13 or the pressure adjusting device 70. The vapor is not accumulated in the fuel reservoir 13.

  According to the first embodiment, the fuel supply apparatus 10A includes a fuel reservoir chamber 13 connected to the suction port 24B, a high pressure fuel passage 17 connected to the supply port 15B, and a pressure adjustment connected to the high pressure fuel passage 17. The housing 11 in which the device insertion hole 65a is formed, the fuel pump 30 that pressurizes the fuel in the fuel reservoir chamber 13 and discharges it to the high pressure fuel passage 17, and the pressure adjustment that adjusts the pressure in the high pressure fuel passage 17 to a predetermined pressure. Device 70. The housing 11 includes a housing main body 11A having a supply port 15B, and a tank insertion part 11B that protrudes integrally with the housing main body 11A and has a suction port 24B and a discharge port 24d. The housing 11 can be directly attached to the fuel tank 2 by inserting the portion 11B into the fuel tank 2. A return path 60A is formed in the housing 11 so as to communicate the pressure adjusting device 70 and the discharge port 24d.

  Therefore, the fuel supply device 10A can directly attach the housing 11 to the fuel tank 2 by opening the suction port 24a and the discharge port 24d of the suction port 24B in the fuel tank 2, so that the suction port 24a and the fuel tank 2 The fuel supply device 10 </ b> A can be mounted on the vehicle body while omitting the low-pressure pipe that connects the two and the discharge pipe that connects the discharge port 24 d and the inside of the fuel tank 2. That is, when the fuel supply device 10A is mounted on the vehicle body, there is no need to route the low-pressure pipe or the discharge tube as in the conventional case, and the number of fuel supply tubes routed for the delivery of fuel to the fuel supply device 10A. Therefore, the fuel supply device 10A can be mounted on the vehicle body without complicating the piping layout of the fuel passage pipe.

  The fuel sent out from the pressure adjusting device 70 flows through the return path 60A and is discharged into the fuel tank 2 from the discharge port 24d. That is, the fuel that is guided and discharged from the high-pressure fuel passage 17 to the pressure adjusting device 70 is returned to the fuel tank 2 without being returned to the fuel pump 30. For this reason, even if vapor is generated in the fuel in the fuel reservoir chamber 13 and the fuel containing vapor is discharged into the high-pressure fuel passage 17, it is discharged from the supply port 15a, or the pressure adjusting device 70 and the return. It returns to the fuel tank 2 through the path 60A. As described above, since the fuel discharged from the pressure adjusting device 70 is not returned to the fuel reservoir chamber 13, it is generated when passing through the vapor previously generated in the fuel in the fuel reservoir chamber 13 or the pressure adjusting device 70. The vapor to be accumulated is not accumulated in the fuel reservoir chamber 13. Accordingly, since the vapor in the fuel reservoir chamber 13 is sequentially discharged, it is possible to avoid the occurrence of vapor lock in the fuel pump 30.

  Further, since the filter 68a is attached to the suction port 24B, impurities in the fuel sucked from the suction port 24B are removed and supplied to the fuel pump 30. Thereby, clean fuel can be supplied to the fuel injection valve 6.

  Further, since the hole shape of the return path component 60 is set so that the pressure loss when the fuel passes through the return path 60A is larger than the pressure loss when the fuel passes through the suction path, the discharge port Backflow in the return path 60 </ b> A from 24 d toward the pressure adjustment device 70 is avoided. Thereby, it can prevent that the foreign material of the fuel in a fuel tank penetrate | invades into the pressure regulator 70 from the discharge port 24d.

  Further, the hole shape of the return path component 60 is set so that the pressure loss when the fuel passes through the return path 60A is smaller than the pressure loss until the fuel is sent out from the pressure regulator 70 after the pressure adjustment. Therefore, when the pressure adjusting device 70 adjusts the pressure in the high-pressure fuel passage 17, the influence exerted by the return path constituting member 60 can be reduced. For example, in order to adjust the pressure of the fuel in the high-pressure fuel passage 17 to a predetermined value, it is necessary to adjust the urging force of the spring 87, but the spring does not take into account the pressure loss of the fuel in the return path 60A. Even when the urging force 87 is adjusted, the pressure adjustment accuracy in the high-pressure fuel passage 17 of the pressure adjusting device 70 can be secured.

  Further, since the filter 68a is configured to cover the discharge port 24d when viewed from above in the fuel tank 2, the foreign matter in the fuel tank 2 can be prevented from entering the discharge port 24d. .

Embodiment 2. FIG.
FIG. 10 is a partially cutaway sectional view of a fuel supply device according to Embodiment 2 of the present invention, and FIG. 11 is an enlarged view of the periphery of the pressure adjustment device of FIG.
10 and 11, the same reference numerals are given to the same portions as those in the first embodiment, and the description thereof is omitted.

  10 and 11, the fuel supply device 10B is similar to the fuel supply device 10A except that a bush 69 is used instead of the bush 61, a cylinder block 40B is used instead of the cylinder block 40A, and an adapter 23B is used instead of the adapter 23A. It is constituted similarly.

The bush 69 is configured by omitting the return path forming block 61B of the bush 61. That is, the bush 69 is composed only of the base 61A.
Further, as shown in FIG. 11, the pressure adjusting device 70 is a cross section formed so as to extend from the drain hole 19 and the drain hole 19 side of the valve unit 50 to the vicinity of the end surface of the cylinder block 40B on the fuel reservoir chamber 13 side. It is disposed in a pressure adjusting device insertion hole 65b formed by coaxially connecting a circular concave hole 66B. The diameter of the recessed hole 66B is smaller than the diameter of the drain hole 19 in a step shape.

  A gap 72a is formed between the end of the casing 71 on the relief port 71c side and the bottom of the recessed hole 66B, and a gap 72b is formed between the outer peripheral surface of the casing 71 and the inner peripheral surface of the recessed hole 66B. ing. The flow path gap 72 includes a gap 72a and a gap 72b connected to the gap 72a. Further, the cylinder block 40B is formed with a feed hole 40a that opens to the outer peripheral surface thereof so that the gap 72b and the fuel reservoir chamber 13 communicate with each other.

  The adapter 23B has a cylindrical return pipe portion 24C that protrudes from the one surface of the closing portion 24A toward the fuel reservoir chamber 13 side. At this time, the tip of the return pipe portion 24C is opposed to the feed hole 40a in the vicinity of the feed hole 40a. The adapter 23B is provided with a return hole 24e that is connected to the return pipe portion 24C and opens to the other surface of the closing portion 24A. The opening on the other surface side of the closing portion 24A of the return hole 24e constitutes the discharge port 24d.

  A rubber tube 75 is fitted at the tip of the return tube portion 24C. One end of the rubber tube 75 is pressed against the outer peripheral surface of the cylinder block 40B so as to surround the feed hole 40a. The rubber pipe 75 connects the return pipe portion 24C and the cylinder block 40B while maintaining liquid tightness and air tightness. A return path 60B from the relief port 71c to the discharge port 24d is constituted by a flow path gap 72, a feed hole 40a, a hole in the rubber tube 75, a hole in the return tube portion 24C, and the return hole 24e. Further, in the fuel reservoir chamber 13, the fuel in the fuel reservoir chamber 13 and the fuel in the return path 60B are separated without being mixed.

  According to the second embodiment, the fuel sent from the pressure adjusting device 70 flows through the return path 60B and is discharged into the fuel tank 2 from the discharge port 24d. That is, the fuel that is guided and discharged from the high-pressure fuel passage 17 to the pressure adjusting device 70 is returned to the fuel tank 2 without being returned to the fuel pump 30. Therefore, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
FIG. 12 is a side view of the fuel supply device according to the third embodiment of the present invention as seen through the fuel tank in a state where the fuel supply device is attached to the fuel tank.
In FIG. 12, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In FIG. 12, the filter 68 b of the fuel supply device 10 </ b> C is connected to the end of the suction port (not shown) on the suction port side and is disposed in the fuel tank 2. However, the filter 68b is not opposed to the opening of the return hole 24c of the closing portion 24A.
The extension return pipe 91 is attached to the closing portion 24A with an opening at one end thereof connected to the return hole 24c. At this time, the opening on one end side is connected to the return hole 24c, and the opening on the other end side is disposed in the atmospheric space 92 of the fuel tank 2 and attached to the closing portion 24A. The atmospheric space 92 is a space formed above the fuel level even when the fuel tank 2 is fully filled. The opening on the other end side of the extension return pipe 91 is a discharge port 91a.
The other configuration of the fuel supply device 10C is the same as that of the first embodiment.

  According to the third embodiment, in addition to the effects of the first embodiment, the discharge port 91a always opens above the fuel level even when the fuel tank 2 is fully filled. Even if foreign matter is mixed in the fuel in the fuel tank 2, the foreign matter in the fuel in the fuel tank 2 moves from the discharge port 91a to the pressure regulator 70 side when the supply of fuel to the fuel pump (not shown) is stopped. We can prevent going.

Embodiment 4 FIG.
FIG. 13 is a cross-sectional view of a main part around the discharge port of the fuel supply apparatus according to Embodiment 4 of the present invention, and shows a state in which the discharge port valve opens the closing port of the discharge port. FIG. 14 is a cross-sectional view of a main part around the discharge port of the fuel supply apparatus according to Embodiment 4 of the present invention, and shows a state in which the discharge port valve closes the discharge port.
In FIG. 13 and FIG. 14, the same reference numerals are given to the same parts as those in the first embodiment, and the description thereof is omitted.

In FIG. 13, the filter 68 c of the fuel supply device 10 </ b> D is connected to the end of the suction port 24 </ b> B on the suction port 24 a side and is disposed in the fuel tank 2. However, the filter 68b is not opposed to the opening of the discharge port 24d of the closing portion 24A. The discharge port valve 93 is supported so as to be rotatable about a horizontal axis fixed to a portion of the closing portion 24A in the vicinity of the discharge port 24d so that the discharge port 24d can be opened and closed.
Other configurations of the fuel supply device 10D are the same as those in the first embodiment.

Hereinafter, the operation of the discharge port valve 93 will be described with reference to FIGS. 5, 13, and 14.
When the differential pressure between the fuel in the high-pressure fuel passage 17 and the fuel in the return path 60A becomes larger than the urging force of the spring 87, and the valve body 85 opens the valve port 82a, the discharge port valve 93 is shown in FIG. As shown in FIG. 5, the fuel flows into the fuel tank 2 so as to open the discharge port 24d. Further, when the valve port 82a is closed by the valve body 85, the pressure of the fuel for opening the discharge port 24d disappears. Therefore, as shown in FIG. 14, the discharge port valve 93 is discharged by its own weight. It rotates in the direction to close the opening.

  According to the fourth embodiment, the discharge port valve 93 opens the discharge port 24d by the pressure of the fuel sent from the relief port 71c of the pressure adjusting device 70, and discharges when the fuel delivery from the relief port 71c stops. Since the outlet 24d is closed, it is possible to prevent the fuel in the fuel tank 2 from entering the return pipe 62 and heading to the pressure adjusting device 70 even when the discharge of the fuel into the fuel tank 2 is stopped.

  In the first, third, and fourth embodiments, the return path 60A is described as being configured by the return path constituent member 60. For example, the return path 60A is a return path forming block of the return path constituent member 60. 61B may be abbreviate | omitted and it may be comprised by the return pipe | tube connected to the relief port 71c of the pressure regulator 70 directly.

  2 Fuel tank, 10A to 10D Fuel supply device, 11 Housing, 13 Fuel reservoir, 15B Supply port, 17 High pressure fuel passage, 24B Suction port, 24d Discharge port, 30 Fuel pump, 60A, 60B Return path, 65a, 65b Pressure Adjustment device insertion hole, 68a filter, 70 pressure adjustment device, 71c relief port, 91a discharge port, 93 discharge port valve.

Claims (7)

A fuel reservoir chamber connected to the intake port, a high pressure fuel passage connected to the supply port, and a pressure adjusting device insertion hole connected to the high pressure fuel passage are formed. A housing;
A fuel pump that pressurizes the fuel in the fuel sump chamber and discharges the fuel into the high-pressure fuel passage;
A relief port disposed in the pressure adjusting device insertion hole for delivering the fuel in the high pressure fuel passage to the outside of the high pressure fuel passage when the pressure in the high pressure fuel passage exceeds a predetermined pressure; A fuel supply device comprising: a pressure adjusting device for adjusting the pressure in the high-pressure fuel passage to a predetermined pressure;
The housing is composed of a housing main body having the supply port, and a tank insertion portion formed integrally with the housing main body to form the suction port and the discharge port.
A return path is formed in the housing so as to communicate the pressure adjusting device and the discharge port,
A fuel supply device in which the tank insertion portion is inserted into a fuel tank, the housing is directly attached to the fuel tank, the fuel in the fuel tank is pressurized to a predetermined pressure and discharged from the supply port.   2. The fuel supply device according to claim 1, further comprising a filter attached to the suction port and configured to remove impurities in the fuel sucked from the suction port.   The pressure loss when the fuel passes through the return path is larger than the pressure loss when the fuel passes through the suction path from the filter to the fuel reservoir chamber through the suction port. The fuel supply device according to claim 2.   The fuel supply device according to claim 2 or 3, wherein the filter is configured to cover the discharge port when viewed from above in the vertical direction in the fuel tank.   The pressure loss when the fuel passes through the return path is smaller than the pressure loss when the fuel passes through the path leading to the relief port after the pressure is adjusted inside the pressure regulator. The fuel supply device according to any one of claims 1 to 4.   6. The discharge port according to claim 1, wherein the discharge port is opened above a liquid level of the fuel when the fuel tank is fully filled. The fuel supply apparatus as described.   A discharge port valve is provided that opens the discharge port by the pressure of the fuel fed from the relief port of the pressure adjusting device and closes the discharge port when the fuel feed from the relief port stops. The fuel supply device according to any one of claims 1 to 5.

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