JP4512152B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a fuel supply device that supplies fuel in a fuel tank to a fuel injection device using a piston pump.

  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 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, since the capacity of the fuel tank is small, it is necessary to review the layout of the fuel tank significantly in order to mount the in-tank fuel supply device. Therefore, in order to make the small displacement engine FI, a small and lightweight in-line fuel supply device that can be mounted on a pipe between the fuel tank and the fuel injection device is desired.

  And since the in-line type fuel supply apparatus needs to self-prime the fuel in the fuel tank, a piston type pump excellent in self-priming performance has been proposed.

  A conventional high-pressure fuel supply pump that employs a piston-type pump includes a driving body that is rotationally driven by an engine, a piston that reciprocates driven by the driving body, and a pump chamber that supports the piston in a reciprocating manner. A first plate having a first suction hole and a first discharge hole, and a reed valve sandwiched between the first plate and the second plate; A second plate having a suction hole and a second discharge hole. The reed valve includes a suction valve that displaces the first suction hole so that the first suction hole can be opened and closed, and a discharge valve that displaces the first discharge hole so that the first discharge hole can be opened and closed. Further, the first suction hole and the second suction hole are opposed to each other via the suction valve, and the first discharge hole and the second discharge hole are opposed to each other via the discharge hole valve (see, for example, Patent Document 1).

  The pressure in the pump chamber fluctuates due to the reciprocating motion of the piston. When the piston moves in one direction, the discharge valve closes the first discharge hole, the suction valve opens the first suction hole, and connects the first suction hole and the second suction hole. At this time, fuel is sucked into the pump chamber from the first suction hole. Further, when the piston moves in the other direction, the suction valve closes the first suction hole, the discharge valve opens the first discharge hole, and connects the first discharge hole and the second discharge hole. At this time, the fuel that has passed through the first discharge hole and the second discharge hole is discharged from the pump chamber.

  Here, in a high-pressure fuel pump that employs this type of piston-type pump, depending on the size and shape of the housing in which the pump is disposed, the location where the pump chamber is formed, the first suction hole, and the pump chamber Proposals have been made in which the shape of the flow path of the communicating fuel is devised.

A conventional fuel supply device 80 that employs a piston-type pump that has been devised in terms of the location where the pump chamber is formed and the flow path of the fuel that communicates between the first suction hole and the pump chamber will be briefly described.
14 is a cross-sectional view of a conventional fuel supply apparatus, FIG. 15 is an enlarged view of a portion B in FIG. 14, and FIG. 16 is a front view taken along arrow XVI-XVI in FIG.

14 to 16, the conventional fuel supply device 80 includes a housing 11 and a fuel pump 84 disposed in the housing 11.
The housing 11 includes a first body portion 12 having a hole portion 13, a high-pressure fuel passage 21, and a second body portion 20 having a protrusion 23 fitted into the hole portion 13.

  The fuel pump 84 has one end inserted coaxially into the hole 13 and is connected to one end of the shaft 31 in the hole 13 by the shaft 31 rotatably supported by the first body 12 via the bearing 38. A swash plate 32 and a motor 33 for rotating the shaft 31 around the axis are provided. Further, the fuel pump 84 is coaxially fitted into the hole 13 and has a cylindrical cylinder block 40 in which the cylinder 41 and the suction hole 42 are formed, and the hole so as to be sandwiched between the protrusion 23 and the cylinder block 40. 13 is provided with a valve ASSY 85 inserted into the cylinder 13 and a piston 47 slidably disposed on the cylinder 41.

The cylinder 41 and the suction hole 42 are formed in the cylinder block 40 such that the respective hole directions coincide with the axial direction of the cylinder block 40.
A spring 49 is disposed between the piston 47 and the cylinder block 40 so as to bias the piston 47 toward the swash plate 32. The piston 47 reciprocates in the cylinder 41 in conjunction with the rotation of the swash plate 32 that is rotated by driving the motor 33.

  Further, the cylinder block 40 and the first body portion 13 cooperate to constitute a fuel reservoir chamber 15. Further, the holding valve disposing hole 26 is formed in the projecting portion 23 so as to open on a surface on the high pressure fuel passage 21 side and a surface facing the valve ASSY 85.

  As shown in FIGS. 15 and 16, the valve ASSY 85 includes a plate 86 formed at a portion where the discharge hole 87 faces the opening of the cylinder 41, and a suction valve plate 90 arranged so as to sandwich the plate 86. And a discharge valve plate 98.

The plate 86 has a suction groove 89 that is recessed so that the cylinder 41 and the suction hole 42 communicate with each other on a surface facing the cylinder block 40 and the suction valve plate 90, and an inside of the suction groove 89 that faces the cylinder 41. It has a discharge hole 87 drilled in this part.
The suction valve plate 90 has a suction valve body (suction valve) 91 configured at a position facing the suction hole 42, and a cylinder connection hole 92 formed so as to communicate the cylinder 41 and the discharge hole 87. is doing.
In FIG. 16, an arrangement position when the suction hole 42 is projected from the hole direction onto the bottom of the suction groove 89 is added by a one-dot chain line.
The depth direction of the suction groove 89 coincides with the thickness direction of the plate 86. At this time, the suction groove 89 is formed to have a constant depth and a substantially constant width throughout the extending direction.

The discharge valve plate 98 has a discharge valve body (discharge valve) 99 that is disposed at a position opposite to the discharge hole 87 and is configured to be displaceable in the thickness direction of the discharge valve plate 98.
A discharge groove 27 is formed at a portion of the projection 23 facing the discharge valve body 99 from the opening on the valve ASSY 85 side of the holding valve arrangement hole 26.

  The suction valve body 91 contacts and separates from the end surface on the suction hole 42 side of the cylinder block 40 according to the pressure difference between the pressure increasing chamber (pump chamber) 95 and the suction hole 42 described below, and the suction hole 42. Open and close. The pressure increasing chamber 95 is a space defined by the piston 47 and the cylinder 41, a cylinder connecting hole 92, a discharge hole 87, and a suction groove 89.

Further, the discharge valve body 99 opens and closes the discharge hole 87 by making contact with and separating from the end surface on the discharge hole 87 side of the plate 86 according to the pressure difference between the pressure increasing chamber 95 and the discharge groove 27. .
That is, while the motor 33 is driven and the piston 47 reciprocates once, a suction process for sucking fuel from the fuel reservoir chamber 15 into the pressure increasing chamber 95 through the suction hole 42 and a discharge groove 27 from the pressure increasing chamber 95. And the discharge process which discharges a fuel to the high pressure fuel passage 21 through the holding valve arrangement | positioning hole 26 is performed.

Japanese Unexamined Patent Publication No. 2000-8998

In the conventional fuel supply device 80, when the suction valve body 91 is displaced so as to release the closing of the suction hole 42 during the suction process, the fuel in the suction hole 42 moves toward the cylinder 41 so that the fuel in the pressure increasing chamber 95 faces. Flow into. At this time, the fuel at the back surface of the suction valve body 91 in the suction groove 89 also moves toward the cylinder 41.
The fuel that passes through the back surface of the suction valve body 91 presses the suction valve body 91 from the back side of the suction valve body 91, thereby preventing the suction valve body 91 from being displaced in the direction of releasing the closing of the suction hole 42. Thereby, the opening degree of the suction valve body 91 is reduced, and the flow of fuel from the suction hole 42 toward the cylinder 41 is inhibited.

Further, part of the fuel colliding with the suction valve body 91 spreads in the opposite direction to the cylinder 41, flows into the suction groove 89, and then flows again in the direction of the cylinder 41.
The fuel once directed in the direction opposite to the cylinder 41 in the suction groove 89 makes a U-turn and moves toward the cylinder 41, so that a vortex is likely to be generated in the fuel flow in the suction groove 89. That is, the flow of fuel from the suction hole 42 toward the cylinder 41 is hindered by the generated vortex.

Here, FIG. 17 is a diagram showing a saturated vapor pressure curve of gasoline as fuel.
In FIG. 17, the horizontal axis represents the fuel pressure in gauge pressure [MPaG], and the vertical axis represents the temperature.
It can be seen from FIG. 17 that vapor is more likely to be generated as the fuel pressure in the pressure increasing chamber 95 is smaller and as the temperature in the pressure increasing chamber 95 is higher.

When the conventional fuel supply device 80 is used, for example, connected in-line between a fuel tank (not shown) of a small motorcycle and a fuel injection device (not shown), the pressure of the fuel in the suction hole 42 is the fuel pressure. It is determined by the positional relationship between the tank and the conventional fuel supply device 80, the piping layout between the fuel tank and the fuel supply device 80, the ambient temperature of the small motorcycle, and the like.
In the case of a general use environment of a small two-wheeled vehicle, the fuel in the pressure increasing chamber 95 is approximately in the hatched region in FIG.

From FIG. 17, when the fuel is sucked into the pressure increasing chamber 95, vapor is generated when the fuel pressure in the pressure increasing chamber 95 decreases.
In the discharge process, when the volume in the pressure increasing chamber 95 decreases, the generated vapor is pressurized and discharged outside the pressure increasing chamber 95. At this time, in order to increase the vapor by a predetermined value, it is necessary to extremely increase the amount of decrease in the volume in the pressure increasing chamber 95 rather than increasing the liquid fuel by a predetermined value. As a result, when vapor is generated in the pressure increasing chamber 95, the volumetric efficiency of the fuel supply device 80 represented by the following expression (1) is remarkably lowered as compared with the case where vapor is not in the pressure increasing chamber 95.

Volumetric efficiency = actual discharge amount / theoretical displacement volume of the piston 47 × 100 [%] (1)
The theoretical displacement volume of the piston 47 corresponds to the volume in the pressure increasing chamber 95 that is reduced by the movement of the piston 47 located at the bottom dead center. Further, the actual discharge amount corresponds to the volume of fuel actually discharged from the discharge hole 87 when the volume in the pressure increasing chamber 95 decreases.
When the vapor is generated in the pressure increasing chamber 95, the volumetric efficiency is lowered. However, in order to avoid the shortage of the fuel discharge amount from the fuel pump 84, the movement amount of the piston 47 is increased or the piston 47 is moved. It is necessary to increase the diameter. That is, the conventional fuel supply device 80 needs to use a large fuel pump 84, and the device cannot be reduced in size.

  The present invention has been made to solve the above-described problem, and provides a fuel supply device that can prevent a decrease in volumetric efficiency by suppressing the amount of vapor generated in a pressure-increasing chamber. The purpose is to obtain.

  The fuel supply device according to the present invention includes a first body portion having a hole opening in one surface and a suction port for sucking fuel into a fuel reservoir chamber formed on the bottom side of the hole portion, and one end inserted into the fuel reservoir chamber. The shaft is supported by the first body portion so as to be rotatable about the axis, the swash plate is fixed to one end of the shaft and rotates in conjunction with the rotation of the shaft, and the hole portion is arranged so as to face the swash plate. A cylinder block in which a fuel reservoir chamber is formed in cooperation with the first body portion, the cylinder and the suction hole are formed so that the hole direction coincides with the axial direction of the shaft, and the biasing force of the biasing means The piston is supported by the swash plate and disposed in the cylinder. The piston slides and moves in the cylinder in conjunction with the rotation of the swash plate, and is disposed on the opening side of the hole of the cylinder block and is opposed to the cylinder block. Communicate the cylinder and suction hole to the surface And a plate having a discharge hole formed in a portion in the suction groove opposite to the cylinder, and a cylinder block and the plate, and held between the cylinder block and the suction groove. Cylinder connection hole that communicates, intake valve plate having an intake valve body that opens and closes the intake hole by contacting and leaving the cylinder block, a high-pressure fuel passage, a discharge port that discharges fuel from the high-pressure fuel passage, and the opening side of the plate hole A protrusion groove that is inserted into the surface of the plate and includes a portion that faces the discharge hole, and a holding valve disposition hole that is formed so as to communicate with the high-pressure fuel passage and the discharge groove. Between the plate and the second body part, and a second body part provided with a fuel pressure holding valve disposed in the holding part and the holding valve disposing hole to open and close the flow of fuel between the discharge groove and the high pressure fuel passage Nipped, held and played And a discharge valve plate having a discharge valve body that opens and closes the discharge hole in contact with and away from the valve, the suction valve body from the part of the valve portion that opens and closes the suction hole and the outer edge of the valve portion to the side opposite to the cylinder connection hole A groove passage portion extending from the portion facing the valve portion to the portion facing the cylinder connection hole, and the valve portion supporting portion, the groove depth being the groove passage. The groove is shallower than the groove.

According to the present invention, since the suction groove is configured to be shallow on the side facing the valve portion support portion, the back side of the suction valve body is released when the suction hole is closed by the suction valve body. There is little fuel flowing to the cylinder side while pressing the suction valve body. Thereby, the opening degree with respect to the suction hole of a suction valve body is ensured. In addition, since the amount of fuel flowing into the suction groove after colliding with the suction valve body and spreading in the direction opposite to the cylinder is suppressed, vortices are less likely to occur in the fuel flow in the suction groove.
That is, since the fuel that has flowed into the pressure increasing chamber from the suction hole flows smoothly to the cylinder side, the generation of vapor in the pressure increasing chamber is suppressed as much as possible. That is, since the volumetric efficiency of the fuel supply device is prevented from being lowered, the fuel supply device can be reduced in size.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a block diagram of a fuel supply system having a fuel supply apparatus according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view of the fuel supply apparatus according to Embodiment 1 of the present invention, and FIG. 4 is an exploded perspective view of main parts of a cylinder block and a valve assembly of the fuel supply device according to the first embodiment, and FIG. 4 is an enlarged cross-sectional view of a main part of the valve assembly of the fuel supply device according to the first embodiment of the present invention. 2 shows a state in which the suction hole is closed and the discharge valve body closes the discharge hole, which corresponds to an enlarged view of part A in FIG. FIG. 5 is an enlarged cross-sectional view of a main part of the valve ASSY of the fuel supply apparatus according to Embodiment 1 of the present invention, in which the valve portion closes the suction hole and the discharge valve body releases the blockage of the discharge hole. It shows the state. 6 is a front view taken along arrow VI-VI in FIG. FIG. 7 shows the plate in the section taken along the line VII-VII in FIG. FIG. 8 shows the plate in the section taken along the line VIII-VIII in FIG. FIG. 9 is a cross-sectional view of the main part showing a state where the piston of the fuel supply apparatus according to Embodiment 1 of the present invention is located at bottom dead center, and FIG. 10 shows the piston of the fuel supply apparatus according to Embodiment 1 of the present invention. It is principal part sectional drawing which shows the state located in the top dead center. FIG. 11 is a diagram showing the relationship between the pump rotation speed of the fuel supply device according to Embodiment 1 of the present invention and the volumetric efficiency of the fuel supply device, using the groove cross-sectional area ratio of the plate as a parameter.
The same parts as those of the conventional fuel supply apparatus will be described with the same reference numerals.

First, the 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 connected to the fuel tank 2 via a low-pressure pipe 3 outside the fuel tank 2, and a fuel supply device 10 via a high-pressure pipe 4. The fuel injection device 6 for injecting the fuel supplied from the fuel supply device 10, the fuel pressure adjusting device 9 disposed in the line of the connecting piping 8 connecting the high pressure pipe 4 and the fuel tank 2, and the fuel supply device 10 To the fuel injection device 6 and a drive control unit 7 for controlling the fuel injection timing from the fuel injection device 6.

  The fuel supply device 10 is configured such that a fuel pump 30 for supplying high-pressure fuel to the fuel injection device 6, a fuel pressure holding valve 29, and the like are provided integrally with the housing 11. The drive control unit 7 controls the supply of fuel to the fuel injection device 6 by performing drive control of the fuel pump 30.

  Further, when the difference between the fuel pressure in the high-pressure pipe 4 and the fuel pressure in the fuel tank 2 becomes larger than a specified value, the fuel pressure adjusting device 9 communicates between the high-pressure pipe 4 and the fuel tank 2 and The fuel is returned to the fuel tank 2. That is, the fuel pressure supplied to the fuel injection device 6 is adjusted to a predetermined value by the fuel pressure adjustment device 9.

Next, details of the fuel supply device 10 will be described.
In FIG. 2, the housing 11 includes a first body portion 12 and a second body portion 20.
The first body portion 12 is opened to a hole 13 having a predetermined depth, and the fuel in the fuel tank 2 (see FIG. 1) is supplied to a fuel reservoir chamber 15 formed on the bottom side of the hole 13. A cylindrical suction port 14 for suction is provided. The hole shape of the hole 13 is a circle. The suction port 14 protrudes from the outer peripheral surface near the bottom of the hole 13 of the first body portion 12 and is connected to the fuel tank 2 via the low-pressure pipe 3 (not shown). At this time, the hole of the suction port 14 is connected to the hole 13 via a communication hole 70 a of a bush 70 described later fitted into the hole 13. In addition, a foreign matter inflow prevention filter 16 is disposed in the suction port 14.
Further, the shaft hole 37 is formed coaxially with the hole 13 so as to open to the bottom of the hole 13.

  The second body portion 20 includes a high-pressure fuel passage 21, a cylindrical discharge port 22 that discharges fuel from the high-pressure fuel passage 21, and a protrusion 23 that is fitted in the hole 13 of the first body portion 12. ing. The protrusion 23 is inserted into a region having a predetermined depth from the opening on one surface of the hole 13. An annular seal member 24 is mounted in a groove 25 that is recessed over the entire circumference in the circumferential direction of the outer peripheral surface of the protrusion 23, and the seal member 24 is pressed against the inner wall of the hole 13. It touches. Although not shown, the discharge port 22 is connected to the fuel injection device 6 via the high-pressure pipe 4.

  Further, a holding valve disposing hole 26 whose hole direction coincides with the depth direction of the hole portion 13 is formed so as to communicate between the high-pressure fuel passage 21 and a discharge groove 27 described later. The fuel pressure holding valve 29 opens and closes the flow of fuel between the discharge groove 27 and the high-pressure fuel passage 21 in accordance with the pressure of the fuel pressurized by the fuel pump 30 and discharged into the discharge groove 27. At this time, when the fuel pump 30 is stopped, the fuel pressure holding valve 29 closes the fuel flow between the discharge groove 27 and the high-pressure fuel passage 21 and holds the fuel pressure in the high-pressure fuel passage 21.

The fuel pump 30 is a positive displacement axial piston pump that is excellent in fuel self-priming performance.
2 to 6, the fuel pump 30 has a shaft 31 having one end inserted into the fuel reservoir chamber 15 and rotatably supported around the shaft through a bearing 38 in the shaft hole 37 of the first body portion 12. A swash plate 32 that is fixed to one end of the shaft 31 in the hole 13 and rotates in conjunction with the rotation of the shaft 31 and a motor 33 that rotates the shaft 31 around the axis are provided.

  Further, the fuel pump 30 is coaxially fitted in the position of the hole 13 between the protrusion 23 and the swash plate 32 in the first body portion 12, and a cylindrical cylinder block 40 in which a cylinder 41 and a suction hole 42 are formed. The valve ASSY 50 sandwiched between the protrusion 13 and the cylinder block 40, the cylindrical bush 70 disposed between the cylinder block 40 and the bottom of the hole 13, and the cylinder 41 are slidably disposed. The piston 47 is provided.

  The cylinder block 40 has an outer peripheral shape that matches the inner peripheral wall surface of the hole 13. The cylinder block 40 and the first body portion 13 cooperate to constitute a fuel reservoir chamber 15. At this time, the fuel reservoir chamber 15 is constituted by a space formed between the cylinder block 40 and the bottom of the hole portion 13. Further, the cylinder 41 and the suction hole 42 are formed in the cylinder block 40 with their respective hole directions aligned with the axial direction of the shaft 31.

  The valve assembly 50 is formed in a disc shape having an outer peripheral shape that matches the inner peripheral wall surface of the hole portion 13, and is fitted into the hole portion 13 so as to be sandwiched between the cylinder block 40 and the protrusion 23. The valve assembly 50 includes a plate 51 disposed on the opening side of the hole 13 of the cylinder block 40, a suction valve plate 55 sandwiched and held between the cylinder block 40 and the plate 51, 2 and a discharge valve plate 66 sandwiched and held between the projecting portion 23 of the body portion 20. In FIG. 3, the discharge valve plate 66 is not shown.

  The plate 51 has a suction groove 53 that is recessed so as to communicate the cylinder 41 and the suction hole 42 on a surface facing the cylinder block 40 and the suction valve plate 55, and a suction groove 53 that faces the cylinder 41. It has a discharge hole 52 drilled in the site. The depth direction of the suction groove 53 coincides with the thickness direction of the plate 51.

  The suction valve plate 55 includes a disk-shaped base portion 56 formed by using a thin metal plate having elasticity, a suction valve body 57 formed at a position facing the suction hole 42 inside the base portion 56, and the base portion 56 and the suction portion. A notch 60 that separates the valve body 57 except for a part thereof, and a cylinder connection hole 61 that is formed in a portion of the base portion 56 facing the cylinder 41 and communicates the cylinder 41 and the suction groove 53. .

  The suction valve body 57 includes a disc-shaped valve portion 58 and a valve portion support portion 59 that extends from a part of the outer edge of the valve portion 58 with a predetermined width in the radial direction of the valve portion 58. Note that the width direction of the valve portion support portion 59 is a direction perpendicular to the extending direction of the valve portion support portion 59 and the thickness direction of the valve portion support portion 59.

At this time, the valve portion support portion 59 extends from the valve portion 58 to the opposite side of the cylinder connection hole 61 in a direction connecting the center of the cylinder connection hole 61 and the center of the valve portion 58.
The suction valve plate 55 is disposed such that the center of the valve portion 58 is located on the axis of the suction hole 42 and the center of the cylinder connection hole 61 is located on the axis of the cylinder 41.

  The suction groove 53 faces the groove passage portion 53b from the portion facing the valve portion 58 to the portion facing the cylinder connection hole 61 and the valve portion support portion 59 side, and the groove depth is larger than that of the groove passage portion 53b. It is constituted by a shallow groove shallow portion 53a.

  The suction groove 53 is arranged so that the cylinder connection hole 61 and the valve portion 58 are positioned inside the suction groove 53 when the suction groove 53, the cylinder connection hole 61 and the valve portion 58 are viewed from the depth direction of the groove. The plate 51 is recessed. In FIG. 6, an arrangement position when the suction hole 42 is projected on the bottom of the suction groove 53 in the depth direction of the groove is added by a one-dot chain line.

At this time, the boundary between the shallow groove portion 53a and the groove passage portion 53b substantially coincides with a portion of the suction hole 42 on the side opposite to the cylinder connection hole 61.
And the bottom face of the groove channel | path part 53b is comprised by the plane which makes groove depth uniform.
Further, the bottom surface of the shallow groove portion 53a is constituted by a flat surface parallel to the bottom surface of the groove passage portion 53b that changes in a step shape with respect to the bottom surface of the groove passage portion 53b.

  The width of the groove passage portion 53b is the same as the diameter of the cylinder 41 between the suction hole 42 and the cylinder connection hole 61 in the extending direction. The groove width direction of the groove passage portion 53 b is a direction perpendicular to the extending direction of the suction groove 53 and the depth direction of the suction groove 53. Hereinafter, the shallow groove portion 53a side of the suction groove 53 is defined as one end side, and the cylinder connection hole 61 side is defined as the other end side.

  Further, the end of the shallow groove portion 53a (one end portion of the suction groove 53) is formed to open in an R shape as shown in FIG. The width of the suction groove 53 is configured to gradually increase from one end thereof toward a position corresponding to the hole center of the suction hole 42.

  Here, FIG. 7 shows two intersections of the edge on both sides in the width direction of the valve portion support portion 59 and the edge of the shallow groove portion 53a when the suction valve body 57 and the suction groove 53 are viewed from the depth direction of the groove. 8 is a cross-sectional view perpendicular to the extending direction of the suction groove 53, and FIG. 8 is a cross-sectional view including the center of the valve portion 58 and perpendicular to the extending direction of the suction groove 53. The cross-sectional areas of the suction grooves 53 in FIGS. 7 and 8 are S1 and S2.

  The suction valve body 57 contacts and separates from the end face on the suction hole 42 side of the cylinder block 40 in accordance with the pressure difference between the pressure increasing chamber 48 and the suction hole 42 described below, and the valve portion 58 opens the suction hole 42. It opens and closes. The pressure increasing chamber 48 includes a space defined by the piston 47 and the cylinder 41, a cylinder connection hole 61, a discharge hole 52, and a suction groove 53.

  The discharge valve plate 66 is formed in a disk shape using a metal material having elasticity, and is interposed between the plate 51 and the protrusion 23 of the second body portion 20. The discharge valve plate 66 includes a discharge valve body 67 that is disposed at a position facing the discharge hole 52 and that is configured to be displaceable in the thickness direction of the discharge valve plate 66.

Here, the discharge groove 27 includes a portion facing the discharge hole 52, and is recessed in the protrusion 23 so as to communicate the holding valve disposition hole 26 and the discharge hole 52.
The discharge valve body 67 contacts and separates from the end surface of the plate 51 on the discharge hole 52 side according to the pressure difference between the pressure increasing chamber 48 and the discharge groove 27 to open and close the discharge hole 52. .

  Further, as shown in FIG. 2, the bush 70 is formed in an outer peripheral cylindrical shape adapted to the inner peripheral surface of the hole 13 with, for example, an iron-based material having elasticity, and the cylinder block in the first body portion 12. It is inserted into a portion between 40 and the bottom of the hole 13. At this time, the urging force of the bush 70 works so that the cylinder block 40 and the valve ASSY 50 are directed in the axial direction of the shaft 31 and toward the protrusion 23.

  Further, as described above, the communication hole 70a is formed in the bush 70 so as to communicate the hole of the suction port 14 and the fuel reservoir chamber 15. That is, the fuel sucked from the suction port 14 flows into the fuel reservoir chamber 15.

  The swash plate 32 is fixed to one end of the shaft 31, and the surface opposite to the mounting surface to the shaft 31 forms an inclined surface 32 a having a predetermined inclination with respect to a plane orthogonal to the axial direction of the shaft 31. is doing.

  One end of the piston 47 is inserted into the cylinder 41 and is slidable along the hole direction of the cylinder 41. The other end of the piston 47 is formed of a hemispherical portion 47a. At this time, the curved surface side of the hemispherical portion 47 a is directed to the swash plate 32. Further, a spring 49 as an urging means is disposed between the hemispherical portion 47 a side of the piston 47 and the cylinder 41. At this time, the urging force of the spring 49 acts in the direction of extracting the piston 47 from the cylinder 41, and the curved surface portion of the hemispherical portion 47 a is in contact with the swash plate 32 in a pressed state.

  The piston 47 arranged as described above is supported on the swash plate 32 by the urging force of the spring 49, and slides and moves in the cylinder 41 in conjunction with the rotation of the swash plate 32. When the swash plate 32 rotates in conjunction with the rotation around the axis of the shaft 31, the piston 47, as shown in FIG. 9, is the bottom dead center where the piston 47 protrudes most from the cylinder 41, and FIG. As shown, the piston 47 reciprocates between the top dead center inserted into the cylinder 41 most.

The fuel supply operation to the fuel injection device 6 in the fuel supply system 1 configured as described above will be described.
Assume that the fuel reservoir 15 is filled with fuel as an initial state.
When the swash plate 32 rotates in conjunction with the rotation of the shaft 31 by the motor 33, the piston 47 reciprocates between the top dead center and the bottom dead center according to the rotation angle of the swash plate 32.

When the piston 47 goes to the position of the bottom dead center, the inside of the pressure increasing chamber 48 is depressurized, and when the piston 47 goes to the top dead center, the inside of the pressure increasing chamber 48 is increased.
At this time, the pressure in the pressure increasing chamber 48 becomes larger or smaller than the pressure in the fuel reservoir chamber 15 due to the reciprocating movement of the piston 47.

  When the pressure in the pressure increasing chamber 48 is lower than the pressure in the fuel reservoir 15, the valve portion 58 is displaced toward the suction groove 53 and the suction hole 42 and the pressure increasing chamber 48 communicate with each other. . When the pressure in the pressure increasing chamber 48 is higher than the pressure in the fuel reservoir 15, the valve portion 58 is displaced toward the cylinder block 40 and closes the suction hole 42. Communication with the chamber 48 is blocked.

  That is, when the piston 47 is displaced in the direction from the top dead center to the bottom dead center, the fuel in the pressure increasing chamber 48 is depressurized, and the suction valve body 57 closes the suction hole 42 by the valve portion 58. Displace to release. At this time, since the pressure in the pressure increasing chamber 48 is low, the discharge valve body 67 is displaced to the plate 51 side to close the discharge hole 52 as shown in FIG.

  The shallow groove portion 53a contacts the suction valve body 57 when the inside of the pressure increasing chamber 48 is depressurized by the displacement of the piston 47 to the bottom dead center and the valve portion 58 releases the closing of the suction hole 42. It is formed to be as shallow as possible without touching it.

  When the suction of the suction hole 42 by the valve part 58 is released, the valve part 58 is inclined with respect to the opening surface of the suction hole 42 so that the cross-sectional area of the fuel flow path becomes wider toward the cylinder 41. is doing. Therefore, the fuel in the suction hole 42 tends to flow toward the cylinder 41 along the inclination of the front surface of the valve portion 58.

When the closing of the suction hole 42 by the valve portion 58 is released, the fuel flows into the pressure increasing chamber 48 from the suction hole 42 toward the cylinder 41, and at this time, the suction valve body in the suction groove 53 is used. The fuel in the rear portion 57 also moves toward the cylinder 41 side.
However, since the back surface side of the valve portion support portion 59 is constituted by the shallow groove portion 53a, the amount of fuel from the back surface of the intake valve body 57 toward the cylinder 41 is small. That is, there is little fuel that presses the suction valve body 57 from the back side of the suction valve body 57.

Here, in FIG. 6, the flow of the fuel that has collided with the valve portion 58 is illustrated by a dotted line with an arrow. The length of the dotted line is proportional to the fuel flow rate.
As shown in FIG. 6, the fuel that collides with the valve portion 58 collides with the valve portion 58 and spreads in the radial direction of the valve portion 58. At this time, since the volume of the shallow groove portion 53a is small, the amount of fuel that goes around the shallow groove portion 53a located on the back surface of the valve portion support portion 59 via the notch 60 is limited.

  Further, the piston 47 is displaced in a direction from the bottom dead center toward the top dead center, so that the inside of the pressure increasing chamber 48 is pressurized. When the inside of the pressure increasing chamber 48 is pressurized, as shown in FIG. 5, the suction hole 42 is closed, the discharge valve body 67 is displaced toward the discharge groove 27, and the plugging of the discharge hole 52 is released. The Then, the high-pressure fuel in the pressure increasing chamber 48 is discharged to the high-pressure fuel passage 21 through the discharge hole 52, the discharge groove 27, and the fuel pressure holding valve 29. The fuel discharged into the high-pressure fuel passage 21 is supplied to the fuel injection device 6 through the discharge port 22 and the high-pressure pipe 4.

Here, if the environment is used for a general small two-wheeled vehicle, the fuel (gasoline) in the pressure-increasing chamber 48 in the suction process is hatched in FIG. 17 as described in the conventional fuel supply device. It is placed under the conditions.
When the inside of the pressure increasing chamber 48 is filled with fuel, the state equation of the pressure inside the pressure increasing chamber 48 is expressed by the following equation (2).
P = K · ΔV / V (2)
P: Fuel pressure K: Fuel bulk modulus (1GPa for gasoline)
ΔV: Volume change amount of the pressure increasing chamber 48 V: Volume when the piston 47 is at the bottom dead center

Further, since the state equation of the pressure in the pressure increasing chamber 48 when vapor is generated in the pressure increasing chamber 48 can be considered that the volume of the pressure increasing chamber 48 changes in an adiabatic state, (3) It can be expressed as an expression.
p · v ^k = p ′ · (v−Δv) ^k (3)
p: pressure in the pressure increasing chamber 48 before the volume change v: volume of the pressure increasing chamber 48 before the volume change p ′: pressure in the pressure increasing chamber 48 after the volume change v−Δv: pressure increasing chamber after the volume change 48 volume Δv: Volume change amount of pressure increasing chamber 48 k: Gas constant (in the case of air, 1.402)

If the adjustment pressure of the fuel pressure adjustment device 9 is set so that the fuel pressure supplied to the fuel injection device 6 is 300 kPaG, the volume change rate reaching 300 kPaG or more is approximately during normal operation when no vapor is generated. 0.06% and very small amount.
The volume change rate represents the volume decrease in the pressure increasing chamber 48 necessary for boosting the fuel to a predetermined pressure as a ratio to the displacement volume.

On the other hand, if vapor is generated and the pressure increasing chamber 48 is filled with vapor, the volume change rate reaching 300 kPaG or more is approximately 88%.
As described above, the volume change rate for increasing the pressure in the pressure increasing chamber 48 to a predetermined pressure is that vapor is generated in the pressure increasing chamber 48 as compared with the case where the pressure increasing chamber 48 is filled with fuel. If so, it will increase rapidly.

  According to the fuel supply device 10 of the first embodiment, since the suction groove 53 is shallow on the back surface of the suction valve body 57 on the valve portion support portion 59 side, the suction hole 42 is blocked by the suction valve body 57. When the is released, the amount of fuel passing through the back surface of the intake valve body 57 is small. That is, since the amount of fuel that presses the suction valve body 57 from the back side of the suction valve body 57 is small, the opening of the valve portion 58 with respect to the suction hole 42 is ensured, and the fuel flow path from the suction hole 42 to the suction groove 53 is ensured. Sufficiently secured. Accordingly, the fuel that has flowed into the pressure increasing chamber 48 from the suction hole 42 flows smoothly to the cylinder 41 side, and the time during which the pressure increasing chamber 48 is in a low pressure state is shortened, so that generation of vapor is suppressed as much as possible. Can do.

  Further, as shown in FIGS. 4 and 6, when the closing of the suction hole 42 by the valve portion 58 is released, the fuel that collided with the valve portion 58 is grooved from the notch 60 on the valve portion support portion 59 side. The flow into the shallow portion 53a is limited. That is, since there is little fuel that once turns in the direction opposite to the cylinder 41 and then makes a U-turn again to the cylinder 41 side, generation of vortices in the fuel flow is suppressed. Thereby, since a small amount of fuel in the shallow groove portion 53a also smoothly moves toward the cylinder 41, the generation of vapor in the pressure increasing chamber 48 can be further suppressed.

  Since the volumetric efficiency of the fuel supply device 10 is improved by suppressing the generation of vapor in the pressure increasing chamber 48, the amount of movement of the piston 47 is reduced in order to avoid a shortage of fuel discharge from the fuel pump 30. There is no need to increase the size or increase the diameter of the piston 47. That is, the fuel supply device 10 can be reduced in size. Further, since it is not necessary to increase the movement amount of the piston 47 or increase the diameter of the piston 47, it is possible to reduce the power consumption of the motor 33 that is a power source for moving the piston 47.

  Further, when the suction groove 53 is formed in the plate 51, when the R shape is formed on one end side, it is only necessary to perform the groove processing on the plate 51 with a drill having a large radius. This is easier than the case where the suction groove 89 shown in FIG. 16 is formed.

Next, a change in the volumetric efficiency of the fuel supply device 10 when the ratio of the cross-sectional area S1 and the cross-sectional area S2 of the suction groove 53 is changed is confirmed by a test, and the content thereof will be specifically described below.
Here, the above-described ratio S1 / S2 between the cross-sectional area S1 and the cross-sectional area S2 is defined as a groove cross-sectional area ratio γ.

In the test, each of the fuel supply devices 10 in which the plates 51 having the groove cross-sectional area ratios γ of 1/2, 1/3, 1/4, and 1/5 are incorporated is prepared. In contrast, FIG. 11 shows the results of measuring the volumetric efficiency variation while varying the pump rotation speed.
One reciprocation of the piston 47 corresponds to one rotation of the pump.

In each fuel supply device 10, when the pump rotation speed is in a range of about 1000 (r / min) or less, the volume efficiency is improved at a substantially constant rate with respect to the increase rate of the pump rotation speed, and the pump rotation speed is 1000 When it was larger than (r / min), the volumetric efficiency was changed at substantially the same value.
At this time, it was confirmed that the volumetric efficiency was improved as the groove cross-sectional area ratio γ was smaller at the same pump rotation speed. Further, it was confirmed that when the groove cross-sectional area ratio γ is ¼ or less, the degree of improvement in volumetric efficiency with respect to the decrease in the groove cross-sectional area ratio γ is saturated.

The above results will be considered below.
As the groove cross-sectional area ratio γ is smaller, the ratio of the area of the valve portion support portion 59 to the area of the valve portion 58 decreases. Therefore, as the groove cross-sectional area ratio γ is smaller, the flow of fuel that presses the valve portion support portion 59 from the back side against the flow of fuel that attempts to displace the valve portion 58 from the suction hole 42 side to the suction groove 53 side. The effect of. As a result, when the piston 47 moves to the bottom dead center, the valve portion 58 is displaced so as to smoothly release the closing of the suction hole 42 against the decompression in the pressure increasing chamber 48 and the valve portion 58 is opened. The degree is secured.

  That is, the smaller the groove cross-sectional area ratio γ, the more smoothly the fuel flows from the suction hole 42 toward the cylinder 41 and the time during which the pressure increasing chamber 48 is in a low pressure state is shortened. Thereby, it is judged that the volumetric efficiency is improved as the groove cross-sectional area ratio γ is smaller.

  Note that when the groove cross-sectional area ratio γ is ¼ or less, among the elements affecting the volume efficiency, any element other than the influence caused by the fuel traveling toward the cylinder 41 through the back surface of the valve portion 58 is Be dominant in determining efficiency. Therefore, when the groove cross-sectional area ratio γ is ¼ or less, it is determined that the degree of improvement in volumetric efficiency with respect to the decrease in the groove cross-sectional area ratio γ is saturated.

  In the first embodiment, the bottom surface of the shallow groove portion 53a is described as being configured by a flat surface parallel to the bottom surface of the groove passage portion 53b that changes stepwise with respect to the bottom surface of the groove passage portion 53b. However, the bottom surface of the shallow groove portion is not limited to a flat surface, and the inclined surface is a flat surface in which the groove depth gradually decreases from the boundary between the shallow groove portion and the groove passage portion toward the shallow groove portion, Alternatively, an inclined surface such as an inclined curved surface formed of a convex or concave curved surface may be used. Even if the bottom surface of the shallow groove portion is an inclined surface, it was confirmed that when the groove cross-sectional area ratio γ was ¼ or less, the degree of improvement in volume efficiency against the decrease in the groove cross-sectional area ratio γ was saturated. .

  In addition, it has been described that the end of the shallow groove portion 53a is formed so as to open in an R shape, but the end portion of the shallow groove portion is not limited to the one opened in an R shape, and the groove What is necessary is just to be comprised so that a width | variety may become narrow gradually at an edge part side.

Embodiment 2. FIG.
FIG. 12 shows the relationship between the pump rotational speed and the volumetric efficiency in the fuel supply apparatus according to Embodiment 2 of the present invention, and the ratio of the groove width and groove depth at the portion between the suction hole of the groove passage portion and the cylinder. It is a figure shown as a parameter.

The configuration of the fuel supply device according to the second embodiment is the same as that of the first embodiment.
Hereinafter, a cross section perpendicular to the extending direction of the suction groove 53 at a portion between the suction hole 42 and the cylinder 41 of the groove passage portion 53b will be described as a cross section of the groove passage portion 53b.
If the sectional area of the groove passage portion 53b is the same, the smaller the difference between the groove width L and the depth H in the section of the groove passage portion 53b, in other words, the closer the L / H ratio is to 1, the groove passage portion 53b. It is known that the pressure loss of the fuel passing through the fuel cell decreases.

  A large pressure loss of the fuel passing through the groove passage portion 53b means that the fuel hardly flows in the groove passage portion 53b. That is, when the pressure in the pressure increasing chamber 48 is reduced and the valve portion 58 of the suction valve body 57 releases the closing of the suction hole 42, the fuel is less likely to flow into the pressure increasing chamber 48. As a result, it takes a long time for the fuel in the pressure increasing chamber 48 to be depressurized, so that vapor is likely to be generated in the pressure increasing chamber 48.

And the volumetric efficiency of the fuel supply apparatus 10 when the cross-sectional area of the groove channel | path part 53b is the same and the ratio (width-depth ratio L / H) of the groove width L and the depth H of the cross section of the groove channel | path part 53b is changed. A test was conducted to confirm the above.
Each of the fuel supply devices 10 in which each of the plates 51 having the suction grooves 53 with the width / depth ratio L / H of 20, 10, 5 is incorporated is prepared, and the pump rotation is performed with respect to each of the fuel supply devices 10. The result of measuring the change in volumetric efficiency while varying the speed is shown in FIG. The groove cross-sectional area ratio γ of the suction groove 53 in each plate 51 is unified to ¼.

In each fuel supply device 10, when the pump rotation speed is in the range of about 700 (r / min) or less, the volume efficiency is improved at a substantially constant rate with respect to the increase rate of the pump rotation speed, and the pump rotation speed is 1000 When it was larger than (r / min), the volumetric efficiency was changed at substantially the same value.
It was confirmed that the volume efficiency improved as the width-depth ratio L / H approached 1 at the same pump rotation speed. When the width / depth ratio L / H is 10 and the width / depth ratio L / H5 are compared, the degree of improvement in volumetric efficiency is slight, and the width / depth ratio L / H is 10 or less. Then, it was confirmed that the degree of improvement in volumetric efficiency with respect to the decrease in the width / depth ratio L / H was saturated.

  Here, for example, the suction groove 53 when the width / depth ratio L / H is 1/10 and the suction groove 53 when the width / depth ratio L / H is 10 are merely reversed in width and depth. is there. That is, the volume efficiency characteristic of the fuel supply device 10 when the width / depth ratio L / H is m is the same as the volume efficiency characteristic of the fuel pump when the width / depth ratio L / H is 1 / m. Become.

Consider the above results.
As described above, as the width / depth ratio L / H becomes closer to 1, the pressure loss of the fuel passing through the groove passage portion 53b decreases, so that the generation of vapor in the pressure increasing chamber 48 is suppressed and the volume efficiency is reduced. However, when the width-to-depth ratio is 1/10 or more and 10 or less, among the factors affecting the volumetric efficiency, factors other than the fluctuation of the fuel pressure loss passing through the groove passage determine the volumetric efficiency. Become dominant. Therefore, even if the width / depth ratio L / H is further closer to 1 from a value of 10 or less, or even when the width / depth ratio L / H is further closer to 1 from a value of 1/10 or more, the width / depth ratio L / H It is determined that the degree of improvement in volumetric efficiency with respect to fluctuation is small.

  As described above, regarding the shape of the groove passage portion 53b, the volume efficiency is effectively improved if the width-depth ratio L / H is in the range of 1/10 or more and 10 or less. In the fuel supply device of the second embodiment, a plate 51 that satisfies this condition is incorporated.

When the width / depth ratio L / H is 1/10 or more and 10 or less, the following effects can also be obtained.
When the cross-sectional area of the groove passage portion 53b is increased, the volume of the pressure increasing chamber 48 is increased. When vapor is generated, the maximum amount of movement of the piston 47 (in order to discharge the vapor from the pressure increasing chamber 48) The lift amount must be increased. That is, it is preferable that the cross-sectional area of the groove passage portion 53b is as small as possible.

  When the width / depth ratio L / H is close to 1, in the cross section of the groove passage portion 53b, the difference in flow velocity between the wall side and the center side of the groove passage portion 53b becomes small, and the fuel generated in the groove passage portion 53b. Therefore, it is determined that the pressure loss of the fuel flowing through the groove passage portion 53b is reduced. If the width-to-depth ratio L / H is in the range of 1/10 or more and 10 or less, the vortex of the fuel generated in the groove passage portion 53b is small, and the decrease in pressure loss is also suppressed. Accordingly, since it is not necessary to enlarge the cross-sectional area of the groove passage portion 53b in order to facilitate the flow of fuel, an effect of suppressing the increase in the volume of the pressure increasing chamber 48 can be obtained.

Embodiment 3 FIG.
FIG. 13 shows a fuel supply apparatus according to Embodiment 3 of the present invention, in which the volume ratio of the pressure increasing chamber and the vapor in the pressure increasing chamber when the volume of the vapor in the pressure increasing chamber is 70% of the volume of the pressure increasing chamber. It is a figure which shows the relationship with the ultimate pressure.
The configuration of the fuel supply device according to the second embodiment is the same as that of the first embodiment.

The functions required of the in-line fuel supply device 10 include a vapor lock avoidance function as well as excellent self-priming performance of fuel from the fuel tank 2.
Here, the fuel supply device 10 is disposed inline between the fuel tank 2 and the fuel injection device 6 below the fuel tank 2, and fuel under atmospheric pressure environment enters the fuel reservoir chamber 15 from the suction port 14. Inhaled. When the fuel pump 30 is stopped, the fuel that has once flown into the pressure increasing chamber 48 falls to the lowermost surface in the pressure increasing chamber 48 due to its own weight. It is never filled with vapor.
When the fuel supply device 10 is arranged in-line in this way, the volume occupied by the vapor may be about 70% at the maximum with respect to the volume of the pressure increasing chamber 48 when the piston 47 is at the bottom dead center. Are known.

Here, the maximum volume that can be taken by the vapor in the pressure increasing chamber 48 when the piston 47 is at the bottom dead center is defined as the maximum occupied volume. The volume of the pressure increasing chamber 48 when the piston 47 is at the bottom dead center is defined as the bottom dead center volume V, and the volume change amount of the pressure increasing chamber 48 with respect to the bottom dead center volume V when the piston 47 is at the top dead center. Is defined as ΔV, and the pressure increase chamber volume ratio is defined as V / (V−ΔV).
Then, when the piston 47 is at the bottom dead center, the pressure increase chamber volume ratio when the ratio of the vapor volume to the bottom dead center volume V is 70% and the pressure increase chamber volume ratio were measured. FIG. 13 shows the relationship with the pressure (attainment pressure) taken by the vapor in the pressure increasing chamber 48. The ultimate pressure is expressed as a gauge pressure.

In FIG. 13, the ultimate pressure has a characteristic of increasing in a quadratic curve as the pressure increasing chamber volume ratio increases.
It should be noted that the volume change rate of the pressure increasing chamber 48 required to boost the vapor in the pressure increasing chamber 48 by a predetermined amount is compared with the volume change rate of the pressure increasing chamber 48 required to boost the liquid fuel by a predetermined amount. Therefore, the influence of the fuel in the pressure increasing chamber 48 on the vapor pressure can be ignored.

For example, it is assumed that the adjustment pressure of the fuel pressure adjustment device 9 is set so that the fuel pressure supplied to the fuel injection device 6 is 300 kPaG. In other words, the fuel supply device 10 is disposed under conditions where the fuel discharged from the discharge port 22 is adjusted to a predetermined pressure (300 kPaG).
From FIG. 13, the pressure increase chamber volume ratio when the ultimate pressure of the vapor is 300 (kPaG) is 1.8.

  Therefore, if the bottom dead center volume V and the volume change amount ΔV are set so that the pressure increasing chamber volume ratio when the piston 47 reciprocates is 1.8 or more, the inside of the pressure increasing chamber 48 is surely obtained. The vapor can be discharged to the fuel injection device 6 side.

Further, when the adjustment pressure of the fuel pressure adjustment device 9 is set so that the fuel pressure supplied to the fuel injection device 6 is 1000 kPa, the pressure increase chamber volume ratio when the piston 47 reciprocates is If the pressure is 2.4 or more, the ultimate pressure of the vapor can be set to 1000 kPaG.
In the fuel supply device 10 in which the pressure increase chamber volume ratio is set to 2.4 or more, the vapor in the pressure increase chamber 48 can be reliably discharged to the fuel injection device 6 side.

For example, when the diameter of the piston 47 is 6 mm and the lift amount of the piston 47 is 3 mm, if the bottom dead center volume V is 191 mm ³ or less, the pressure increasing chamber volume ratio can be 1.8 or more.
Similarly, when the diameter of the piston 47 is 6 mm and the lift amount of the piston 47 is 3 mm, the pressure increasing chamber volume ratio can be 2.4 or more if the bottom dead center volume is 145 mm ³ or less.

In summary, the vapor occupies the maximum volume possible in the pressure increasing chamber 48.
The pressure increasing chamber volume ratio so that the pressure reached by the vapor in the pressure increasing chamber 48 when the piston 47 moves from the bottom dead center to the top dead center is equal to or higher than the adjustment pressure (predetermined pressure) of the fuel pressure adjusting device 9. Therefore, the vapor in the pressure increasing chamber 48 can be reliably discharged to the fuel injection device 6 side.
In other words, even when the fuel in the fuel tank 2 runs out and the amount of vapor in the pressure increasing chamber 48 increases, when the fuel is supplied again into the fuel tank 2, the vapor smoothly increases in the pressure increasing chamber 48. It is discharged from the inside. That is, since the vapor lock is avoided, the fuel supply device 10 can resume the supply of fuel to the fuel injection device 6.

  In each of the above embodiments, the shallow groove portion 53a has been described as being configured such that the groove width gradually narrows on the end side. However, the groove width portion has a groove width on the end side. For example, the groove width may be constant or may be changed stepwise.

1 is a configuration diagram of a fuel supply system having a fuel supply apparatus according to Embodiment 1 of the present invention. FIG. It is sectional drawing of the fuel supply apparatus which concerns on Embodiment 1 of this invention. It is a disassembled perspective view of the principal part of the cylinder block and valve | bulb ASSY of the fuel supply apparatus which concerns on Embodiment 1 of this invention. It is a principal part expanded sectional view of valve | bulb ASSY of the fuel supply apparatus which concerns on Embodiment 1 of this invention. It is a principal part expanded sectional view of valve | bulb ASSY of the fuel supply apparatus which concerns on Embodiment 1 of this invention. It is the VI-VI arrow front view of FIG. The plate in the VII-VII arrow cross section of FIG. 6 is shown. The plate in the VIII-VIII arrow cross section of FIG. 6 is shown. It is principal part sectional drawing which shows the state which the piston of the fuel supply apparatus which concerns on Embodiment 1 of this invention located in the bottom dead center. It is principal part sectional drawing which shows the state which the piston of the fuel supply apparatus which concerns on Embodiment 1 of this invention located in the top dead center. It is a figure which shows the relationship between the pump rotational speed of the fuel supply apparatus which concerns on Embodiment 1 of this invention, and the volumetric efficiency of a fuel supply apparatus by using the groove cross-sectional area ratio of a plate as a parameter. In the fuel supply device according to Embodiment 2 of the present invention, the relationship between the pump rotation speed and the volumetric efficiency is shown by using the ratio of the groove width and the groove depth at the portion between the suction hole of the groove passage portion and the cylinder as a parameter. FIG. In the fuel supply device according to Embodiment 3 of the present invention, the pressure increase chamber volume ratio and the vapor pressure reached in the pressure increase chamber when the volume of the vapor in the pressure increase chamber is 70% of the volume of the pressure increase chamber. It is a figure which shows the relationship. It is sectional drawing of the conventional fuel supply apparatus. It is the B section enlarged view of FIG. It is a XVI-XVI arrow front view of FIG. It is a figure which shows the saturated vapor pressure curve of gasoline as a fuel.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Fuel supply apparatus, 12 1st body part, 13 hole part, 14 suction port, 15 Fuel reservoir chamber, 20 2nd body part, 21 High pressure fuel passage, 22 Discharge port, 23 Protrusion part, 26 Holding valve arrangement | positioning hole, 27 Discharge groove, 29 Fuel pressure holding valve, 31 Shaft, 32 Swash plate, 40 Cylinder block, 41 Cylinder, 42 Suction hole, 47 Piston, 49 Spring (biasing means), 51 Plate, 52 Discharge hole, 53 Suction groove, 53a Shallow groove portion, 53b groove passage portion, 55 suction valve plate, 57 suction valve body, 58 valve portion, 59 valve portion support portion, 61 cylinder connection hole, 66 discharge valve plate, 67 discharge valve body.

Claims (4)

A first body portion having a hole opening in one surface and a suction port for sucking fuel into a fuel reservoir chamber formed on the bottom side of the hole;
A shaft having one end inserted into the fuel sump chamber and rotatably supported by the first body portion about an axis;
A swash plate fixed to one end of the shaft and rotating in conjunction with the rotation of the shaft;
The fuel reservoir chamber is formed in cooperation with the first body portion so as to face the swash plate, and the cylinder and the suction hole are arranged in the axial direction of the shaft. A cylinder block formed to match,
A piston supported by the swash plate by the urging force of the urging means and disposed in the cylinder, and slidably moving in the cylinder in conjunction with the rotation of the swash plate;
A suction groove disposed on the opening side of the hole of the cylinder block and recessed in a surface facing the cylinder block so as to communicate the cylinder and the suction hole; and the suction facing the cylinder A plate having a discharge hole drilled in a site in the groove;
A suction valve having a cylinder connection hole that is sandwiched and held between the cylinder block and the plate and communicates the cylinder and the suction groove, and a suction valve body that opens and closes the suction hole in contact with and away from the cylinder block. The board,
A high-pressure fuel passage, a discharge port for discharging fuel from the high-pressure fuel passage, and is fitted into the opening side of the hole of the plate, and is recessed on the surface facing the plate including a portion facing the discharge hole. A discharge groove, a protrusion having a holding valve disposition hole formed to communicate the high pressure fuel passage and the discharge groove, and the discharge groove and the high pressure fuel disposed in the retention valve disposition hole; A second body part provided with a fuel pressure holding valve for opening and closing the flow of fuel to and from the passage;
A discharge valve plate that is sandwiched and held between the plate and the second body part and has a discharge valve body that opens and closes the discharge hole in contact with and away from the plate;
The suction valve body has a valve portion that opens and closes the suction hole, and a valve portion support portion that extends from a part of the outer edge of the valve portion to the side opposite to the cylinder connection hole,
A groove passage portion where the suction groove extends from a portion facing the valve portion to a portion facing the cylinder connection hole, and a groove shallow portion facing the valve portion support portion and having a groove depth shallower than the groove passage portion. It is comprised by these. The fuel supply apparatus characterized by the above-mentioned. The boundary between the shallow groove portion and the groove passage portion is disposed at a position facing the portion of the suction hole opposite to the cylinder connection hole,
The bottom surface of the groove passage portion is constituted by a plane having a uniform groove depth,
The groove width of the shallow groove portion is configured to be gradually narrowed on the end side, and the bottom surface of the shallow groove portion is parallel to the bottom surface of the groove passage portion that changes stepwise with respect to the groove passage portion. A flat surface or an inclined surface in which the groove depth gradually decreases from the boundary between the groove shallow portion and the groove passage portion toward the end of the groove shallow portion,
The intersection of the edge portion on both sides in the width direction of the valve portion support portion and the shallow groove portion when the valve portion support portion and the suction groove are viewed from the depth direction of the suction groove. The cross-sectional area S1 of the shallow groove portion in the cross section perpendicular to the current direction and the cross-sectional area S2 of the groove passage portion in the cross section that includes the center of the cylinder connection hole and is perpendicular to the extending direction of the suction groove are S1 / 2. The fuel supply apparatus according to claim 1, wherein S2 ≦ 1/4 is satisfied.   The groove passage portion is formed so as to satisfy 1/10 ≦ L / H ≦ 10 when the width of the portion between the suction hole and the cylinder of the groove passage portion is L and the depth is H. The fuel supply device according to claim 1 or 2, wherein the fuel supply device is provided. 4. The fuel according to claim 1, wherein fuel under atmospheric pressure is sucked into the fuel reservoir chamber from the suction port, and the fuel discharged from the discharge port is disposed under a condition in which the fuel is adjusted to a predetermined pressure. A fuel supply device according to any one of the preceding claims,
A pressure increasing chamber is constituted by a space defined by the piston and the cylinder, the cylinder connection hole, the discharge hole, and the suction groove;
The volume of the pressure increasing chamber when the piston is at the bottom dead center is defined as a bottom dead center volume V, and the volume change amount of the pressure increasing chamber with respect to the bottom dead center volume V when the piston is at the top dead center is As ΔV, the volume ratio of the pressure increasing chamber is defined as V / (V−ΔV),
Under the condition that the vapor occupies the maximum possible volume in the pressure increasing chamber, the ultimate pressure of the vapor in the pressure increasing chamber when the piston moves from the bottom dead center to the top dead center is equal to or higher than the predetermined pressure. The fuel supply device is characterized in that the pressure increasing chamber volume ratio is set so that

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