JP2015098849A - High pressure pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure pump capable of connecting a plurality of fuel pipes to a low-pressure fuel passage communicating with a pressurization chamber with a simple constitution.SOLUTION: A high pressure pump 10 includes a union bolt 71 on a cover 30 forming a fuel chamber 31 communicating with a pressurization chamber 18 for pressurizing a fuel. The union bolt 71 has an axial passage 74 axially extended and opened to the fuel chamber 31, and a radial passage 75 communicating with the axial passage 74 and opened in the radial direction of the union bolt 71. An eye connector 80 disposed between a head portion 72 of the union bolt 71 and the cover 30 has a first pipe mounting port 81 and a second pipe mounting port 82 communicating with the radial passage 75 of the union bolt 71. Thus the plurality of fuel pipes 110, 120 are connected to the fuel chamber 31 only at one processing part of the high pressure pump 10.

Description

  The present invention relates to a high pressure pump.

Conventionally, a high-pressure pump that pressurizes fuel by reciprocating movement of a plunger is known. The high-pressure pump pressurizes the fuel pumped from the fuel tank and pumps the fuel to a high-pressure fuel rail provided with a plurality of injectors that directly inject the fuel into the cylinders of the internal combustion engine.
The high-pressure pump described in Patent Document 1 includes a first low-pressure fuel port in a pump body that forms a fuel passage to which fuel is supplied, and a second cover that forms a fuel chamber that communicates with the fuel passage together with the pump body. It has a low-pressure fuel port.
The first low-pressure fuel port supplies the fuel pumped up from the fuel tank by the low-pressure fuel pump to the fuel passage. On the other hand, the second low-pressure fuel port supplies fuel from the fuel chamber to a low-pressure fuel rail provided with a plurality of injectors that inject fuel into a port of the internal combustion engine.

JP 2011-179319 A

However, since the high-pressure pump described in Patent Document 1 includes two low-pressure fuel ports in the pump body and the cover, there is a concern that the manufacturing process becomes complicated and the manufacturing cost increases.
In the high-pressure pump described in Patent Document 1, a second low-pressure fuel port provided in the cover extends upward from the cover. For this reason, the body height of the high-pressure pump becomes high, and it may be difficult to attach it to the engine room. Furthermore, since the direction of the two low-pressure fuel ports is fixed in this high-pressure pump, there is a concern that it is difficult to route the fuel pipe attached thereto in the engine room.

  The present invention has been made in view of the above problems, and provides a high-pressure pump capable of connecting a plurality of fuel pipes with a simple configuration to a low-pressure fuel passage communicating with a pressurizing chamber in which fuel is pressurized. For the purpose.

  The present invention relates to a high-pressure pump in which a union bolt is attached to a low-pressure fuel passage formed in a housing, and a first pipe attachment port in which an eye connector provided between the head of the union bolt and the housing communicates with the low-pressure fuel passage; It has the 2nd piping attachment port, It is characterized by the above-mentioned.

  Thereby, by providing one union bolt in the housing, it is possible to connect the first pipe mounting port and the second pipe mounting port of the eye connector to different fuel pipes. Therefore, there is only one processing portion of the housing for connecting a plurality of fuel pipes to the low pressure fuel passage. Therefore, this high-pressure pump can connect a plurality of fuel pipes to the low-pressure fuel passage with a simple configuration.

Moreover, since this high pressure pump can install fuel piping in the radial direction of a union bolt, it can reduce a physique compared with the high pressure pump of patent document 1 mentioned above.
Furthermore, since this high-pressure pump can set the first pipe attachment port and the second pipe attachment port of the eye connector at an arbitrary angle, the degree of freedom in handling the fuel pipe can be increased.

1 is a configuration diagram of a fuel supply system provided with a high-pressure pump according to a first embodiment of the present invention. It is sectional drawing of the high pressure pump by 1st Embodiment. It is a principal part expanded sectional view of the high pressure pump by a 1st embodiment. It is a top view of the high pressure pump by a 1st embodiment. It is sectional drawing of the high pressure pump by 2nd Embodiment of this invention. It is sectional drawing of the high pressure pump by 3rd Embodiment of this invention. It is sectional drawing of the VII-O-VII line of FIG. It is sectional drawing of the high pressure pump by 4th Embodiment of this invention. It is sectional drawing of the high pressure pump by 5th Embodiment of this invention. It is an expanded sectional view of the union bolt of the high pressure pump by a 5th embodiment. It is sectional drawing of the high pressure pump by 6th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A fuel supply system provided with the high-pressure pump of the first embodiment of the present invention is shown in FIG. In the fuel supply system 1, the fuel pumped from the fuel tank 2 by the low pressure fuel pump 3 is supplied to the high pressure pump 10 through the first fuel pipe 110.
The high-pressure pump 10 includes fuel branching means 70 that branches the fuel supplied from the first fuel pipe 110 into a fuel chamber 31 that communicates with the pressurizing chamber 18 of the high-pressure pump 10 and a second fuel pipe 120. .

  The fuel that has flowed into the fuel chamber 31 from the fuel branching means 70 is sucked into the pressurizing chamber 18 by the lowering of the plunger 12 that reciprocates along the profile of the camshaft 4, and is driven by the raising of the plunger 12 and the electromagnetic drive unit 50. The metering and pressurization are performed by controlling the closing time of the suction valve 43. The fuel pressurized in the pressurizing chamber 18 is pumped from the high pressure fuel pipe 5 to the high pressure fuel rail 6 by opening the discharge valve 63. The high-pressure fuel accumulated in the high-pressure fuel rail 6 is directly injected into a cylinder of an internal combustion engine (not shown) from a plurality of injectors 7 attached thereto.

On the other hand, the fuel that has flowed from the fuel branching means 70 to the second fuel pipe 120 is supplied to the low-pressure fuel rail 8. The low pressure fuel stored in the low pressure fuel rail 8 is injected into a port of an internal combustion engine (not shown) from a plurality of injectors 9 attached thereto.
The low-pressure fuel rail 8 and the injector 9 according to the present embodiment correspond to an example of a “fuel injection device” recited in the claims.

Next, the configuration of the high-pressure pump 10 will be described with reference to FIGS.
As shown in FIG. 1, the high-pressure pump 10 includes a cylinder 11, a plunger 12, a lower pump body 13, an upper pump body 14, a cover 30, a fuel supply unit 40, an electromagnetic drive unit 50, a fuel discharge unit 60, and a fuel branching unit. 70 and the like.
The cylinder 11, the lower pump body 13, the upper pump body 14, and the cover 30 according to the present embodiment correspond to an example of a “housing” described in the claims.
Further, the cylinder 11 and the upper pump body 14 of the present embodiment correspond to an example of “a pump body having a pressurizing chamber” described in the claims.

The cylinder 11 is formed in a cylindrical shape, and a plunger 12 is accommodated therein so as to be able to reciprocate. The lower pump body 13 and the upper pump body 14 are fixed to the outer wall of the cylinder 11 in the radially outward direction. The lower pump body 13 can be mounted in a high-pressure pump mounting hole provided in an internal combustion engine (not shown).
The cover 30 is formed in a bottomed cylindrical shape, and an opening end thereof is liquid-tightly fixed to the lower pump body 13 by welding or the like. A fuel chamber 31 filled with fuel is formed inside the cover 30.
The fuel chamber 31 of the present embodiment corresponds to an example of a “low pressure fuel passage” recited in the claims.

  A pulsation damper 32 is provided inside the cover 30. The outer edge of the pulsation damper 32 is sandwiched between the upper fixing member 33 and the lower fixing member 34, and is installed between the upper pump body 14 and the cover 30. In the pulsation damper 32, the outer edges of the two diaphragms 35 and 36 are joined, and a gas having a predetermined pressure is sealed in an inner sealed space. The pulsation damper 32 reduces the fuel pressure pulsation in the fuel chamber 31 by elastically deforming the two diaphragms 35 and 36 in the thickness direction with the center portion at the center according to the change in the fuel pressure in the fuel chamber 31. .

  A first spring 17 is provided between an oil seal holder 15 fixed to the lower pump body 13 and a spring seat 16 fixed to the lower end portion of the plunger 12. The first spring 17 biases the plunger 12 toward the camshaft 4 of the internal combustion engine. Therefore, the plunger 12 reciprocates in the axial direction along the profile of the camshaft 4.

A pressurizing chamber 18 is formed between the upper end portion of the plunger 12 and the inner wall of the cylinder 11. The pressurizing chamber 18 is open on both sides of the cylinder 11 in the radial direction.
The upper pump body 14 is formed in a substantially rectangular parallelepiped shape, and a hole 141 provided in the center is oil-tightly fastened to the cylinder 11 and fixed to the upper side of the lower pump body 13. The upper pump body 14 has a fuel supply portion mounting hole 142 and a fuel discharge portion mounting hole 143 communicating with the pressurizing chamber 18 of the cylinder 11.

The fuel supply unit 40 includes an intake valve body 41, an intake valve seat member 42, an intake valve 43, a stopper member 44, and the like.
The intake valve body 41 is formed in a cylindrical shape and is fixed to a fuel supply portion mounting hole 142 of the upper pump body 14.
A cylindrical intake valve seat member 42 is provided inside the intake valve body 41. The suction chamber 45 formed inside the suction valve seat member 42 communicates with the fuel chamber 31 outside the upper pump body 14 through a hole 46 provided in the upper pump body 14. The suction valve seat member 42 has a suction valve valve seat 47 at the opening of the suction chamber 45 on the pressurizing chamber side.
The suction valve 43 is provided on the pressurizing chamber side of the suction valve valve seat 47, and can be seated or separated from the suction valve valve seat 47. The suction valve 43 contacts the stopper member 44 when the valve is opened.
A second spring 48 is provided between the stopper member 44 and the suction valve 43. The second spring 48 biases the suction valve 43 toward the valve seat.

The electromagnetic drive unit 50 includes a flange 51, a fixed core 52, a movable core 53, a rod 54, a coil 55, a third spring 56, and the like.
The flange 51 is fixed to the outer wall of the intake valve body 41. A movable core 53 is provided inside the suction valve body 41 so as to be reciprocally movable. A rod 54 is fixed at the center of the movable core 53. A guide member 57 fixed to the inside of the suction valve body 41 supports the rod 54 so as to be capable of reciprocating in the axial direction. The third spring 56 biases the movable core 53 and the rod 54 toward the pressurizing chamber. The rod 54 can press the suction valve 43 toward the pressurizing chamber.

A fixed core 52 is provided on the side of the movable core 53 opposite to the pressure chamber, and a coil 55 is provided on the radially outer side of the fixed core 52. When the coil 55 is energized through the terminal 581 of the connector 58, magnetic flux flows through a magnetic circuit constituted by the movable core 53, the fixed core 52, the flange 51, the yoke 59, etc., and the movable core 53 and the rod 54 are connected to the third spring. It is magnetically attracted to the fixed core side against the urging force of 56.
On the other hand, when the energization to the coil 55 is stopped, the magnetic flux flowing through the magnetic circuit described above disappears, and the movable core 53 and the rod 54 are urged toward the pressurizing chamber by the third spring 56.

The fuel discharge unit 60 includes a fuel discharge housing 61, a discharge valve body 62, a discharge valve 63, a relief valve 64, and the like.
The fuel discharge housing 61 is formed in a substantially cylindrical shape and is press-fitted into a fuel discharge portion mounting hole 143 of the upper pump body 14. A discharge valve body 62 is provided inside the fuel discharge housing 61. The discharge valve body 62 has a discharge valve valve seat 66 on the fuel outlet 65 side.
The discharge valve 63 is provided on the fuel outlet 65 side of the discharge valve body 62, and can be seated and separated from the discharge valve valve seat 66. The discharge valve spring 67 urges the discharge valve 63 to the discharge valve valve seat 66.
The discharge valve body 62 has a relief valve valve seat 68 on the pressurizing chamber side. The relief valve 64 is provided on the pressure chamber side of the relief valve seat 68, and can be seated and separated from the relief valve seat 68. The relief valve spring 69 biases the relief valve 64 toward the relief valve valve seat 68. A relief passage 621 formed inside the relief valve valve seat 68 communicates with the fuel outlet 65.

As shown in FIGS. 3 and 4, the fuel branch means 70 includes a union bolt 71 and an eye connector 80.
The union bolt 71 is attached to a cylindrical member 85 that is welded and fixed to the upper side of the cover 30 in the gravity direction. The cylindrical member 85 has a female screw formed on the inner diameter side. Note that the cylindrical member 85 and the cover 30 may be integrally formed.
The union bolt 71 has a head portion 72 formed in a hexagonal shape when viewed from the axial direction, and a shaft portion 73 extending from the head portion 72 in a columnar shape. The male screw formed on the outer diameter side of the shaft portion 73 is screwed into the female screw of the cylindrical member 85.
The shaft portion 73 of the union bolt 71 has an axial passage 74 that extends in the axial direction and opens into the fuel chamber 31, and a radial passage 75 that opens in the radial direction. The shaft passage 74 and the diameter passage 75 communicate with each other.

The eye connector 80 is provided between the head 72 of the union bolt 71 and the cylindrical member 85. A ring-shaped gasket 86 is provided between the eye connector 80 and the union bolt 71 to prevent fuel leakage. The eye connector 80 has a cylindrical space 83 that is recessed radially outward from the inner wall of the central hole through which the union bolt 71 is inserted. This cylindrical space 83 communicates with the diameter passage 75 of the union bolt 71.
Further, the eye connector 80 has a first pipe mounting port 81 and a second pipe mounting port 82 that open in the radial direction from the cylindrical space 83. Therefore, the first pipe attachment port 81 and the second pipe attachment port 82 communicate with the diameter passage 75 and the shaft passage 74 of the union bolt 71. As shown in FIG. 4, the angle formed by the first pipe mounting port 81 and the second pipe mounting port 82, or the direction thereof, is the first fuel pipe 110 and the second fuel pipe 120 that are routed in the engine room. Is set to conform to. FIG. 4 shows an example of the first pipe attachment port 81 and the second pipe attachment port 82, and the angle and direction formed by these can be arbitrarily set.

As described above, the first fuel pipe 110 is a pipe through which the fuel pumped up from the fuel tank 2 flows. The second fuel pipe 120 is a pipe that supplies fuel to the low-pressure fuel rail 8.
The first fuel pipe 110 is connected to the first pipe attachment port 81 of the eye connector 80 by a quick connector system or brazing. The second fuel pipe 120 is connected to the second pipe attachment port 82 of the eye connector 80 by a quick connector system or brazing.

Next, an operation in which the high pressure pump 10 pumps fuel to the high pressure fuel rail 6 will be described.
(1) Suction stroke When the plunger 12 is lowered from the top dead center toward the bottom dead center by the rotation of the camshaft 4, the volume of the pressurizing chamber 18 increases and the fuel is depressurized. The discharge valve 63 is seated on the valve seat 66 and closes the discharge passage 600.
On the other hand, the suction valve 43 moves to the pressurization chamber side against the urging force of the second spring 48 due to the differential pressure between the pressurization chamber 18 and the suction chamber 45 and is opened.
By opening the suction valve 43, the fuel in the fuel chamber 31 passes through the suction chamber 45 and flows into the pressurization chamber 18.

(2) Metering stroke When the plunger 12 rises from the bottom dead center toward the top dead center due to the rotation of the camshaft 4, the volume of the pressurizing chamber 18 decreases. At this time, since energization to the coil 55 is stopped until a predetermined time, the rod 54 presses the suction valve 43 to the pressurizing chamber side by the urging force of the third spring 56. Therefore, the intake valve 43 maintains the valve open state.
By opening the intake valve 43, the pressurized chamber 18 and the fuel chamber 31 are maintained in communication with each other. For this reason, the low-pressure fuel once sucked into the pressurizing chamber 18 is returned to the fuel chamber 31, and the fuel pressure in the fuel chamber 31 increases. On the other hand, the pressure in the pressurizing chamber 18 does not increase.

When the coil 12 is energized at a predetermined time while the plunger 12 is rising from the bottom dead center toward the top dead center, the magnetic attraction between the fixed core 52 and the movable core 53 is caused by the magnetic field generated in the coil 55. Force is generated. When this magnetic attractive force becomes larger than the difference between the elastic force of the second spring 48 and the elastic force of the third spring 56, the movable core 53 moves to the fixed core side. Thereby, the pressing force of the rod 54 against the suction valve 43 is released.
Then, the suction valve 43 moves in the valve closing direction following the operation of the rod 54 by the elastic force of the second spring 48 and the dynamic pressure of the low-pressure fuel discharged from the pressurizing chamber 18 toward the suction chamber. It sits on the valve seat 47 for the intake valve. Thereby, the pressurizing chamber 18 and the suction chamber 45 are shut off.

(3) Discharge stroke After the suction valve 43 is closed, the fuel pressure in the pressurizing chamber 18 increases as the plunger 12 rises. When the force that the fuel pressure in the pressurizing chamber 18 acts on the discharge valve 63 becomes larger than the sum of the force that the fuel pressure on the fuel outlet side acts on the discharge valve 63 and the biasing force of the discharge valve spring 67, the discharge valve 63. Opens. Thereby, the high-pressure fuel pressurized in the pressurizing chamber 18 is discharged from the fuel outlet 65.

Note that energization of the coil 55 is stopped in the middle of the discharge stroke. Since the force that the fuel pressure in the pressurizing chamber 18 acts on the suction valve 43 is larger than the urging force of the third spring 56, the suction valve 43 maintains the closed state.
The high-pressure pump 10 repeats an intake stroke, a metering stroke, and a discharge stroke, pressurizes and discharges an amount of fuel necessary for the internal combustion engine. This high-pressure fuel is pumped from the high-pressure fuel pipe 5 connected to the fuel outlet 65 to the high-pressure fuel rail 6.

Next, the operation of the high pressure pump 10 when the fuel injection from the injector 7 of the high pressure fuel rail 6 is stopped and the fuel is injected from the injector 9 of the low pressure fuel rail 8 will be described.
Also in this case, the plunger 12 reciprocates in the axial direction by the rotation of the camshaft 4. However, since the high-pressure pump 10 does not discharge fuel to the high-pressure fuel rail 6, the discharge valve 63 closes the discharge passage 600 and the suction valve 43 remains open. Therefore, the fuel goes back and forth between the pressurizing chamber 18 and the fuel chamber 31. At this time, in the pulsation damper 32, the two diaphragms 35 and 36 are elastically deformed according to the change in the fuel pressure in the fuel chamber 31, and the fuel pressure pulsation in the fuel chamber 31 is reduced.

The fuel that has flowed from the fuel tank 2 into the first pipe attachment port 81 of the eye connector 80 through the first fuel pipe 110 passes from the second pipe attachment port 82 through the second fuel pipe 120 to the low pressure fuel rail 8. Supplied.
When the fuel temperature in the high-pressure pump rises due to heat received from the internal combustion engine and vapor is generated in the fuel in the high-pressure pump, the vapor rises upward in the direction of gravity, and the shaft passage 74 and the radial passage of the union bolt 71 75 flows to the first fuel pipe 110 or the second fuel pipe 120. Since the fuel flowing there is relatively cold, the vapor disappears.

The high-pressure pump 10 of the first embodiment has the following operational effects.
(1) In the first embodiment, the eye connector 80 provided with the union bolt 71 on the cover 30 of the high-pressure pump 10 has a first pipe attachment port 81 and a second pipe attachment port 82.
Thereby, it is possible to connect the plurality of fuel pipes 110 and 120 to the eye connector 80 by attaching one union bolt 71 to the cover 30 of the high-pressure pump 10. Therefore, there is only one machining point for connecting the first fuel pipe 110 and the second fuel pipe 120 to the fuel chamber 31 of the high-pressure pump 10. Therefore, the high-pressure pump 10 can connect the plurality of fuel pipes 110 and 120 to the fuel chamber 31 with a simple configuration.
Moreover, since the high pressure pump 10 of 1st Embodiment can install the 1st fuel piping 110 and the 2nd fuel piping 120 in the radial direction of the union bolt 71, it can reduce the physique of an axial direction. Is possible.
Furthermore, since the high-pressure pump 10 of the first embodiment can set the first pipe mounting port 81 and the second pipe mounting port 82 of the eye connector 80 at arbitrary angles, The degree of freedom in handling the first fuel pipe 110 and the second fuel pipe 120 can be increased.

(2) In the first embodiment, the first fuel pipe 110 that supplies the fuel pumped up from the fuel tank 2 can be connected to the first pipe attachment port 81 of the eye connector 80. A second fuel pipe 120 that supplies fuel to the low-pressure fuel rail 8 can be connected to the second pipe attachment port 82 of the eye connector 80.
Thereby, it is possible to connect the fuel tank 2 to the high pressure pump 10 only by the first fuel pipe 110. Therefore, the fuel supply system 1 of the internal combustion engine can be simplified.

(3) In the first embodiment, the union bolt 71 is attached to the upper side of the cover 30 in the gravity direction.
Thus, when vapor is generated in the fuel in the high-pressure pump due to the heat of the internal combustion engine, the vapor can be released to the first fuel pipe 110 or the second fuel pipe 120.

Hereinafter, in a plurality of embodiments, the same numerals are given to the composition substantially the same as composition of a 1st embodiment mentioned above, and explanation is omitted.
(Second Embodiment)
FIG. 5 shows a cross-sectional view of the high-pressure pump 10 according to the second embodiment of the present invention. FIG. 5 is a cross section perpendicular to the axis of the plunger 12.
In the second embodiment, the union bolt 71 constituting the fuel branching means 70 is screwed into a cylindrical member 85 that is welded and fixed to the side surface of the cover 30. Note that the cylindrical member 85 and the cover 30 may be integrally formed. An eye connector 80 is provided between the head 72 of the union bolt 71 and the cylindrical member 85. The first fuel pipe 110 and the second fuel pipe 120 attached to the first pipe attachment port 81 and the second pipe attachment port 82 of the eye connector 80 are disposed on the side surface of the high-pressure pump 10.
In the second embodiment, it is possible to reduce the size of the high-pressure pump 10 in the axial direction as compared with the first embodiment.

(Third embodiment)
Sectional views of the high-pressure pump 10 according to the third embodiment of the present invention are shown in FIGS.
In the third embodiment, the union bolt 71 that constitutes the fuel branching means 70 is formed in the pump body 19 and is therefore screwed into the screw 191. An eye connector 80 is provided between the head 72 of the union bolt 71 and the pump body 19.
The pump body 19 of the present embodiment corresponds to an example of a “housing” described in the claims.
The first fuel pipe 110 and the second fuel pipe 120 attached to the first pipe attachment port 81 and the second pipe attachment port 82 of the eye connector 80 are disposed on the side surface of the high-pressure pump 10.

The shaft passage 74 of the union bolt 71 communicates with the fuel passage 192 of the pump body 19 that supplies fuel to the fuel chamber 31 where the pulsation damper 32 is installed. The fuel passage 192 of the present embodiment corresponds to an example of a “low pressure fuel passage” recited in the claims.
In the third embodiment, the union bolt 71 can be firmly fixed to the pump body 19.

(Fourth embodiment)
FIG. 8 shows a cross-sectional view of the high-pressure pump 10 according to the fourth embodiment of the present invention.
In the fourth embodiment, the eye connector 80 constituting the fuel branching means 70 includes an orifice 84 in the second pipe attachment port 82. The orifice 84 has such a size that the fuel pressure of the low-pressure fuel rail 8 can be maintained at the target pressure.
In the fourth embodiment, the orifice 84 can suppress the pressure pulsation of the fuel due to the reciprocating movement of the plunger 12 from being transmitted to the low pressure fuel rail 8 through the second fuel pipe 120.

(Fifth embodiment)
9 and 10 are sectional views of the high-pressure pump 10 according to the fifth embodiment of the present invention.
In the fifth embodiment, a check valve 90 is provided in the shaft passage 74 of the union bolt 71 that constitutes the fuel branching means 70. The check valve 90 includes a spherical valve body 91, a spring 92 as an urging means, a spring stopper 93, and the like. The valve body 91 can be seated and separated from a valve seat 94 provided on the inner wall of the shaft passage 74. The spring 92 biases the valve body 91 toward the head side of the union bolt 71. The spring stopper 93 adjusts the load of the spring 92 based on the amount of press-fitting, and prevents the spring 92 from coming out of the shaft passage 74.
When the valve body 91 of the check valve 90 is separated from the valve seat 94, the flow of fuel from the first fuel pipe 110 and the second fuel pipe 120 to the fuel chamber 31 is allowed. On the other hand, when the valve body 91 is seated on the valve seat 94, the fuel flow from the fuel chamber 31 to the first fuel pipe 110 and the second fuel pipe 120 is interrupted.

  In the fifth embodiment, when the fuel is discharged from the high-pressure pump 10 to the high-pressure fuel rail 6, the valve body 91 of the check valve 90 is separated from the valve seat 94 in the intake stroke in which the plunger 12 descends, and the first fuel Fuel is supplied from the pipe 110 to the fuel chamber 31. Further, in the metering stroke until the plunger 12 is raised, the valve body 91 of the check valve 90 is seated on the valve seat 94 and the fuel from the fuel chamber 31 to the first fuel pipe 110 and the second fuel pipe 120 is transferred. The flow is interrupted. Therefore, the fuel pressure pulsation is prevented from being transmitted from the fuel chamber 31 to the first fuel pipe 110 and the second fuel pipe 120.

  On the other hand, in the fifth embodiment, when the fuel discharge from the high-pressure pump 10 to the high-pressure fuel rail 6 is stopped, when the plunger 12 is raised, the check valve 90 is seated on the valve seat 94 and the fuel chamber 31 The flow of fuel to the first fuel pipe 110 and the second fuel pipe 120 is interrupted. Therefore, the fuel pressure pulsation is prevented from being transmitted from the fuel chamber 31 to the first fuel pipe 110 and the second fuel pipe 120. At this time, the pulsation damper 32 is elastically deformed in a direction in which the two diaphragms 35 and 36 approach each other, and the volume of the fuel chamber 31 is increased. Therefore, when the plunger 12 is next lowered, the two diaphragms 35 and 36 are greatly elastically deformed in the direction away from each other by the reaction, and the volume of the fuel chamber 31 is reduced. Accordingly, since sufficient fuel that fills the pressurizing chamber 18 is supplied from the fuel chamber 31, the valve body 91 of the check valve 90 does not move away from the valve seat 94 and the first fuel pipe 110 and the second fuel pipe. The fuel is prevented from being supplied from 120 to the fuel chamber 31. Therefore, the pressure increase in the fuel chamber 31 is prevented.

In the fifth embodiment, the check valve 90 provided in the shaft passage 74 of the union bolt 71 prevents the fuel pressure pulsation due to the reciprocating movement of the plunger 12 from being transmitted to the low pressure fuel rail 8 through the second fuel pipe 120. Can do. Further, the check valve 90 can suppress the pressure pulsation of the fuel from being transmitted to the low pressure fuel pump 3 through the first fuel pipe 110. That is, in the fifth embodiment, transmission of pressure pulsation to the first fuel pipe 110 and the second fuel pipe 120 can be prevented.
In the fifth embodiment, when the high-pressure pump 10 is not discharging fuel, the operation of the two diaphragms 35 and 36 of the pulsation damper 32 is increased so that the first fuel pipe 110 and the second fuel pipe It is possible to prevent the fuel from flowing into the fuel chamber 31 from 120. Therefore, an increase in pressure in the fuel chamber 31 can be prevented.

(Sixth embodiment)
A cross-sectional view of a high-pressure pump 10 according to a sixth embodiment of the present invention is shown in FIG.
In the sixth embodiment, the union bolt 71 that constitutes the fuel branching means 70 is formed on the cover 30 and is therefore screwed into the screw 301. An eye connector 80 is provided with a gasket 87 between the head 72 of the union bolt 71 and the cover 30.
In the sixth embodiment, the cylindrical member 85 for attaching the union bolt 71 to the cover 30 can be eliminated. Therefore, the manufacturing cost of the high pressure pump 10 can be reduced.

(Other embodiments)
In the fifth embodiment described above, the check valve is a ball type composed of a spherical valve body, a spring, a spring stopper, and the like.
On the other hand, in other embodiments, various check valves such as a poppet type, a swing type, a wafer type, a lift type or a foot type can be applied.

In the fifth embodiment described above, a check valve is provided in the shaft passage of the union bolt. Moreover, in 4th Embodiment, the orifice was provided in the 2nd piping attachment port of the eye connector.
On the other hand, in other embodiments, a groove having a function of an orifice may be provided in the valve body or the valve seat of the check valve. Thereby, the vapor generated in the high-pressure pump can be released to the first fuel pipe and the second fuel distribution through the groove. It is also possible to prevent an increase in pressure in the fuel chamber at high temperatures.
The present invention is not limited to the above-described plurality of embodiments. In addition to combining the above-described plurality of embodiments, the present invention can be implemented in various forms without departing from the spirit of the invention.

10: High pressure pump 31: Fuel chamber (low pressure fuel passage)
71 ... Union bolt 72 ... Head 74 ... Shaft passage 75 ... Diameter passage 81 ... First pipe attachment port 82 ... Second pipe attachment port 80 ... Eye connector 192 ..Fuel passage (low pressure fuel passage)

Claims (8)

A plunger (12);
A housing (11, 13, 14, 19, 30) having a pressurizing chamber (18) in which fuel is pressurized by the reciprocating movement of the plunger and a low-pressure fuel passage (31, 192) for supplying fuel to the pressurizing chamber. )When,
A union bolt (71) attached to the housing;
An axial passage (74) extending in the axial direction of the union bolt and opening to the low-pressure fuel passage of the housing; and a radial passage (75) communicating with the axial passage and opening in the radial direction of the union bolt;
An eye provided between the housing (72) of the union bolt and the housing, having a first pipe mounting port (81) and a second pipe mounting port (82) communicating with the radial passage of the union bolt. A high-pressure pump (10) comprising a connector (80). A first fuel pipe (110) for supplying fuel pumped up from a fuel tank can be connected to the first pipe attachment port of the eye connector,
2. The high-pressure pump according to claim 1, wherein a second fuel pipe (120) for supplying fuel to the fuel injection device is connectable to the second pipe attachment port of the eye connector.   Provided in the shaft passage of the union bolt, allowing a flow of fuel from the first pipe attachment port and the second pipe attachment port to the low pressure fuel passage, and from the low pressure fuel passage to the first pipe attachment port; The high-pressure pump according to claim 1 or 2, further comprising a check valve (90) for blocking fuel flow to the second pipe attachment port.   The check valve includes a valve body (91) that can be seated and separated from a valve seat (94) provided on an inner wall of the shaft passage of the union bolt, and the valve body to the head side of the union bolt. The high-pressure pump according to claim 3, further comprising a biasing means (92) for biasing.   The high-pressure pump according to claim 1 or 2, further comprising an orifice (84) provided in the second pipe attachment port of the eye connector. The housing includes a pump body (11, 14) having the pressurizing chamber, and a cover (30) provided outside the pump body and forming the low pressure fuel passage (31) together with the pump body,
The high pressure pump according to any one of claims 1 to 5, wherein the union bolt is attached to an upper side of the cover in the direction of gravity. The housing includes a pump body having the pressurizing chamber, and a cover that is provided outside the pump body and forms the low-pressure fuel passage together with the pump body,
The high pressure pump according to any one of claims 1 to 5, wherein the union bolt is attached to a side surface of the cover. The housing includes a pump body (19) having the low pressure fuel passage (192) communicating with the pressurizing chamber,
The high pressure pump according to any one of claims 1 to 5, wherein the union bolt is attached to the low pressure fuel passage of the pump body.

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