JP5673284B2 - High pressure pump - Google Patents

Description

  The present invention relates to a high pressure pump.

  2. Description of the Related Art Conventionally, a high-pressure pump that is provided in a fuel supply system that supplies fuel to an internal combustion engine and that feeds the fuel under pressure is known. The high pressure pump sucks fuel from the supply passage into the pressurizing chamber and pressurizes it by the reciprocating motion of the plunger accommodated in the cylinder. A seal member is provided on the radially outer wall of the plunger exposed from the side opposite to the pressurizing chamber of the cylinder. The seal member regulates fuel leakage from the clearance between the plunger and the cylinder to the internal combustion engine, and restricts intrusion of engine oil from the internal combustion engine into the high-pressure pump.

  The high-pressure pump of Patent Literature 1 is provided with an insertion portion (“connection short pipe portion 50” in Patent Literature 1) that extends in a cylindrical shape toward the opposite side of the pressurizing chamber on the end surface opposite to the pressurizing chamber of the housing. Yes. The insertion portion is inserted into a mounting hole of a high pressure pump provided in the internal combustion engine, and positions the high pressure pump. The seal member includes a fuel seal element (“Piston seal member 62” in Patent Document 1) and a plunger stopper (“Stopper 78” in Patent Document 1) having a substantially cylindrical shape (“Stopper element 60” in Patent Document 1). It is composed by being assembled to. The holding member has an outer wall in the radially outward direction (“fixed section 76” or “outer section 76” in Patent Document 1) fixed to an inner wall in the radially inward direction of the insertion portion (paragraph of the specification of Patent Document 1). “0038” “0041”, see FIGS. 2 and 3.

The high-pressure pump described in FIGS. 1 to 4 of Patent Document 2 has a configuration in which fuel leaked from the gap between the cylinder and the plunger returns to the fuel tank through the leak passage 51. The seal member (“annular seal member 40” in Patent Document 2) is provided inside the cylinder.
In the high-pressure pump of Patent Document 3, a seal member is provided inside the cylinder.

In FIG. 5 and FIG. 6 of Patent Document 2 and Patent Document 4, the seal member (“Mechanical Seals 64, 65, 68” in Patent Document 2 and “Lip 74” in Patent Document 4) is in the radial direction of the seal member. The area where the plunger and the seal member are in contact with each other is smaller than the area of the inner wall.
In FIG. 7 and FIG. 8 of Patent Document 2, an annular groove is provided on the side opposite to the pressurizing chamber of the cylinder and is recessed toward the pressurizing chamber, and a seal member (“annular seal member 40” in Patent Document 2) is provided in the annular groove. Is inserted. The sealing member has both the sealing performance between the radially inner wall and the plunger outer wall and the sealing performance between the radially outer wall and the annular groove inner wall.

JP 2008-525713 A JP-A-4-353262 JP-A-11-82226 Japanese Patent No. 3199105

By the way, since the high-pressure pump regulates fuel leakage from the high-pressure pump to the internal combustion engine and regulates the intrusion of engine oil into the high-pressure pump, the seal member and the plunger are highly required to be coaxial. If the coaxiality between the seal member and the plunger is not ensured, abnormal wear may occur in the fuel seal element constituting the seal member, which may reduce the pressure resistance of the seal member. Thus, when fuel leaks from the high-pressure pump to the internal combustion engine, the fuel is mixed into the engine oil, and there is a concern that the internal combustion engine may deteriorate in lubrication. Moreover, there is a concern that the fuel consumption will deteriorate. On the other hand, when engine oil is mixed into the high-pressure pump from the internal combustion engine, deposits may accumulate on the injector supplied with fuel from the high-pressure pump. In addition, there is a concern about the deterioration of lubrication of the internal combustion engine due to a decrease in engine oil. There is also a concern that the consumption of engine oil will increase.
In Patent Document 1, the outer diameter of the plunger, the inner diameter and the outer diameter of the cylinder, the inner diameter of the insertion portion provided in the housing, the outer diameter of the holding member, the inner diameter of the fuel seal element attachment position of the holding member, and the inner diameter of the fuel seal element And, regarding the outer diameter, the coaxiality between the seal member and the plunger is maintained by ensuring the processing accuracy. As described above, when the processing accuracy of many members is required, it is difficult to make the seal member and the plunger coaxial, and there is a concern that the manufacturing cost increases.

  In FIGS. 1 to 4 of Patent Document 2 and Patent Document 3, it is difficult to incorporate a seal member into a small-diameter cylinder of a high-pressure pump. For this reason, as shown in FIGS. 7 and 8 of Patent Document 2, an annular groove 66 that is recessed toward the pressurizing chamber is provided on the end surface of the cylinder opposite to the pressurizing chamber, and a seal member is provided in the annular groove 66. It can be considered to fit. However, if the push plate 73 or the C ring 74 that closes the annular groove is installed after the sealing member is fitted, there is a concern that the manufacturing cost increases due to an increase in the number of parts.

In FIG. 5 and FIG. 6 of Patent Document 2 and Patent Document 4, when the pressure of the fuel leaking from the gap between the plunger and the cylinder is substantially equivalent to the atmospheric pressure as the fuel tank, the seal member leaks fuel from the high-pressure pump. It is possible to regulate the intrusion of engine oil into the high-pressure pump. However, in recent years, the high pressure pump employs a leak returnless system configured to return the fuel leaked from the gap between the plunger and the cylinder to the supply passage of the high pressure pump without returning the fuel to the fuel tank. For this reason, the fuel pressure leaked from the gap between the plunger and the cylinder is equivalent to the fuel pressure in the supply passage higher than the atmospheric pressure. In this case, there is a concern that the seal member opens in the radially outward direction due to the fuel pressure, and the pressure resistance deteriorates. On the other hand, when the fuel enters the outside of the diameter of the seal member, the tightening force of the seal member increases. For this reason, abnormal wear of the seal member or the plunger may occur.
In FIGS. 7 and 8 of Patent Document 2, the sealing force between the inner wall in the radial direction of the seal member and the outer wall of the plunger and the outer wall in the radial direction and the inner wall of the annular groove are increased by increasing the tightening force of the seal member. Sealability is maintained. However, when the tightening force of the seal member is increased, abnormal wear of the seal member or the plunger may occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-pressure pump capable of enhancing the pressure resistance of a seal member that prevents fuel leakage from a gap between a plunger and a cylinder.

In order to solve the above-described problem, according to the first aspect of the present invention, the high-pressure pump driven by the camshaft of the internal combustion engine includes a plunger, a housing, a suction valve portion, a discharge valve portion, a cylinder, and a seal member.
The plunger reciprocates in the axial direction by the rotation of the camshaft. The housing has a pressurizing chamber in which fuel is pressurized by the plunger. A suction valve portion provided in a supply passage for supplying fuel to the pressurizing chamber opens and closes the supply passage. A discharge valve portion provided in a discharge passage for discharging fuel pressurized in the pressurizing chamber opens and closes the discharge passage. The cylinder includes a housing portion that reciprocally moves the plunger in the housing, an annular portion that extends radially outward from a side opposite to the pressurizing chamber of the housing portion, and a side opposite to the axial pressure chamber from the outer edge of the annular portion. And an insertion portion that can be inserted into a high-pressure pump mounting hole provided with a camshaft of the internal combustion engine. The seal member formed in a substantially annular shape is a plunger whose outer wall in the radially outer direction is liquid-tightly connected to the inner wall of the insertion portion of the cylinder, and the inner wall in the radially inner direction is exposed from the accommodating portion of the cylinder to the side opposite to the pressure chamber. It is in fluid-tight sliding contact with the outer wall in the radial direction.

Thereby, it becomes possible to form the accommodating part of a cylinder, an annular part, and an insertion part coaxially by cutting, for example. For this reason, the coaxiality of the plunger accommodated in an accommodating part and the sealing member connected to an insertion part increases. Therefore, wear of the seal member or the plunger is suppressed, and the pressure resistance of the seal member can be increased.
The high-pressure pump includes an annular plunger stopper that is provided between the accommodating portion of the cylinder and the seal member and has an insertion hole through which the plunger is inserted. A sub pressurizing chamber is provided between the plunger stopper and the plunger.
The high-pressure pump includes a flange and a housing cover. The flange can be attached to the outside of the diameter of the high-pressure pump attachment hole of the internal combustion engine. The annular housing cover has a cylindrical first heat-insulating space that connects the housing and the flange and can suppress heat transfer from the internal combustion engine to the cylinder on the radially inner side.
Thereby, it becomes possible to reduce the loss of the material by the cutting process of the housing at the time of forming the 1st heat insulation space. Therefore, the manufacturing cost of the housing can be reduced.
Further, the supply passage is provided with a first fuel chamber for reducing fuel pressure pulsation caused by fuel sucked into the pressurizing chamber and fuel discharged from the pressurizing chamber. The first heat insulation space communicates with the first fuel chamber and the sub pressurization chamber.
Thereby, the fuel of a 1st fuel chamber and a sub pressurization chamber distribute | circulates to a 1st heat insulation space. Accordingly, since the volume for storing fuel in communication with the supply passage is increased, fuel pressure pulsation generated in the supply passage can be reduced, and the suction efficiency can be improved.

According to the invention described in claim 2, the seal member includes the fuel seal element, the holding member, and the oil seal.
The fuel seal element is formed in a cylindrical shape, and is in fluid-tight sliding contact with the outer wall in the radially outward direction of the plunger exposed on the opposite side of the pressurizing chamber from the cylinder accommodating portion.
In the holding member, the outer wall in the radially outer direction is liquid-tightly connected to the inner wall of the insertion portion of the cylinder, and the inner wall in the radially inner direction holds the fuel seal element.
The oil seal has one axial side connected to the holding member, and the other side is in liquid-tight sliding contact with the outer radial wall of the plunger on the side opposite to the pressurizing chamber of the holding member.
Thereby, the fuel seal element can enhance pressure resistance without increasing the tightening force.

According to the third aspect of the invention, the auxiliary pressurizing chamber communicates with the gap between the cylinder accommodating portion and the plunger, and communicates with the supply passage through the communicating passage.

According to the fourth aspect of the present invention, the plunger has a large-diameter portion provided on the pressurizing chamber side, and a plunger stopper formed on the opposite side of the large-diameter portion to the pressurizing chamber and having an outer diameter smaller than that of the large-diameter portion. A small diameter portion through which the insertion hole is inserted. The auxiliary pressurizing chamber sucks and discharges the fuel in the supply passage through the communication passage by the reciprocating movement of the plunger.
Thereby, when the fuel is discharged from the pressurizing chamber to the supply passage, the fuel is sucked into the sub pressurization chamber from the supply passage. Further, when the fuel is sucked from the supply passage into the pressurization chamber, the fuel is discharged from the sub pressurization chamber to the supply passage. Therefore, the fuel pressure pulsation generated in the supply passage is reduced, and the suction efficiency can be improved.

According to the fifth aspect of the present invention, the communication passage communicates between the intake fuel reservoir formed in the intake valve portion and constituting a part of the supply passage and the auxiliary pressurizing chamber.
As a result, the flow rate of the supply passage that communicates the first fuel chamber and the suction valve portion is reduced compared to the configuration in which the fuel in the auxiliary pressurization chamber flows through the first fuel chamber to the intake fuel reservoir. It is possible to reduce the volume of. For this reason, the internal diameter of a supply passage can be made small and the physique of a high pressure pump can be made small.

According to the invention described in claim 6 , the oil seal has an oil seal element and an oil seal outer ring. The oil seal element is in fluid-tight contact with the outer wall of the plunger in the radially outward direction on the opposite side of the pressurizing chamber from the holding member. The oil seal outer ring is formed in a substantially cylindrical shape, and one side in the axial direction is connected to the holding member, and the other side holds the oil seal element.
The high-pressure pump has a cylindrical second heat insulating space between the oil seal outer ring and the holding member that can suppress heat transfer from the internal combustion engine to the sub pressurizing chamber.
When the high-pressure pump is installed in the high-pressure pump mounting hole of the internal combustion engine, the oil of the internal combustion engine is applied to the oil seal. Further, the heat of the internal combustion engine is transferred to the oil seal. Here, the heat transfer coefficient of air is much smaller than the heat transfer coefficient of metal. For this reason, if air etc. are enclosed in the 2nd heat insulation space, the heat transfer from an oil seal to a sub pressurization room can be controlled by the 2nd heat insulation space. Thereby, the temperature rise of the fuel flowing from the auxiliary pressurizing chamber to the supply passage is suppressed, and the generation of vapor in the supply passage can be suppressed. Therefore, it is possible to suppress the vapor lock from occurring in the high-pressure pump, and it is possible to suppress problems such as deterioration in startability.

1 is a cross-sectional view of a high pressure pump according to a first embodiment of the present invention. The principal part sectional view of the high-pressure pump by a 1st embodiment of the present invention. III-III sectional view taken on the line of FIG. Sectional drawing of the high pressure pump by 2nd Embodiment of this invention. Sectional drawing of the high pressure pump by 3rd Embodiment of this invention. Sectional drawing of the high pressure pump by 4th Embodiment of this invention. Sectional drawing of the high pressure pump by 5th Embodiment of this invention. Sectional drawing of the high pressure pump by 6th Embodiment of this invention. Sectional drawing of the high pressure pump by 7th Embodiment of this invention. Sectional drawing of the principal part of the high pressure pump by 7th Embodiment of this invention. XI-XI sectional view taken on the line of FIG. XII-XII sectional view taken on the line of FIG. XIII-XIII sectional view taken on the line of FIG. Sectional drawing of the high pressure pump by 8th Embodiment of this invention. Sectional drawing of the principal part of the high-pressure pump by 9th Embodiment of this invention. XVI-XVI sectional view taken on the line of FIG. Sectional drawing of the high pressure pump by 10th Embodiment of this invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A high-pressure pump according to a first embodiment of the present invention is shown in FIGS. The high-pressure pump 10 is attached to a cylinder head of the internal combustion engine 200 or the like. The high-pressure pump 10 pressurizes the fuel pumped up by a low-pressure pump from a fuel tank (not shown) and discharges it to the delivery pipe. The high-pressure fuel stored in the delivery pipe is injected from the injector into the cylinder of the internal combustion engine.

The high-pressure pump 10 includes a housing 11, a cylinder 14, a plunger 13, a seal member 50, a damper device 5, a suction valve unit 30, an electromagnetic drive unit 70, a discharge valve unit 90, and the like.
The plunger 13 has a large-diameter portion 133 provided on the pressurizing chamber 121 side, and a small-diameter portion 131 having an outer diameter smaller than that of the large-diameter portion 133 on the opposite side of the large-diameter portion 133 from the pressurizing chamber 121. ing. A step surface 132 is formed at a connection portion between the small diameter portion 131 and the large diameter portion 133.
The housing 11 is provided with a cylinder 14. The cylinder 14 has a housing portion 15, an annular portion 16, and an insertion portion 17 as a unit. The accommodating part 15 is formed in a substantially cylindrical shape, and accommodates the large-diameter part 133 of the plunger 13 in the housing 11 so as to be capable of reciprocating. The plunger 13 is provided so that the large-diameter portion 133 faces the pressurizing chamber 121 formed on one side of the accommodating portion 15.
The annular portion 16 extends annularly in the radially outward direction from the opposite side of the accommodating portion 15 to the pressurizing chamber 121. A step 161 that is recessed in the radially inward direction is provided on the radially outer wall of the annular portion 16. A fitting portion 113 that extends in a cylindrical shape from the end surface of the housing 11 on the internal combustion engine 200 side is fitted to the step 161.
The insertion portion 17 extends from the outer edge of the annular portion 16 in the axial direction to the side opposite to the pressurizing chamber 121. The insertion portion 17 is inserted into the high-pressure pump mounting hole 201 provided with the camshaft 7 of the internal combustion engine 200. An O-ring 171 is fitted in a groove formed in the outer wall of the insertion portion 17 in the radially outward direction. The O-ring 171 prevents engine oil from leaking from the space between the high pressure pump mounting hole 201 and the insertion portion 17 to the outside air, and prevents water and the like from entering the internal combustion engine 200 from the outside air side.

A substantially annular sealing member 50 is provided between the small diameter portion 131 of the plunger and the insertion portion 17 of the cylinder 14. The seal member 50 includes a fuel seal element 51, a holding member 52, and an oil seal 60.
The fuel seal element 51 includes an inner circumferential Teflon ring 53 (“Teflon” is a registered trademark) and an outer circumferential O-ring 54. The Teflon ring 53 is in fluid-tight sliding contact with the radially outer wall of the small diameter portion 131 exposed from the accommodating portion 15 of the cylinder 14 of the plunger 13. The fuel seal element 51 regulates the thickness of the fuel oil film around the small diameter portion 131 and suppresses fuel leakage to the internal combustion engine 200 due to the sliding of the plunger 13.
The holding member 52 includes a fixing portion 55, a connection portion 56, and a holding portion 57, and is formed integrally in a substantially annular shape. The outer wall in the radially outward direction of the fixing portion 55 is liquid-tightly connected to the inner wall of the insertion portion 17 of the cylinder 14. The connection part 56 connects the axial direction pressurization chamber 121 side of the fixing part 55 and the axial direction pressurization chamber 121 side of the holding part 57. The holding portion 57 holds the fuel seal element 51 on the inner wall in the radial inner direction.
The oil seal 60 has an oil seal element 61 formed in a substantially cylindrical shape and an oil seal outer ring 62. The oil seal element 61 is in fluid-tight sliding contact with the outer wall of the small-diameter portion 131 of the plunger 13 on the side opposite to the pressurizing chamber 121 of the holding member 57. The oil seal element 61 restricts the thickness of the oil oil film around the small diameter portion 131 and prevents the engine oil from entering the housing 11. The oil seal outer ring 62 is formed in a substantially cylindrical shape, and one side in the axial direction is connected to the holding member 52, and the other side holds the oil seal element 61.

  A spring 19 is provided between the connecting portion 56 of the holding member 52 and the spring seat 18 provided at the end of the plunger 13 opposite to the pressurizing chamber 121. The spring seat 18 is biased toward the camshaft 7 by the force of the spring 19 extending in the axial direction. The plunger 13 reciprocates in the axial direction along the cam profile of the camshaft 7 to change the volumes of the pressurizing chamber 121 and the sub-pressurizing chamber 122 described later.

  A plunger stopper 80 is provided between the fuel seal element 51 and the cylinder 14. The plunger stopper 80 is formed in an annular shape, and has an annular base portion 81 and a plurality of protruding portions 82. The small diameter portion 131 of the plunger 13 is inserted into the insertion hole 83 provided in the base portion 81. The plurality of projecting portions 82 extend from the base portion 81 toward the axial cylinder 14 side. Grooves 84 are radially formed between the protrusions 82 and the protrusions 82. An end surface of the protruding portion 82 on the axial pressure chamber 121 side is in contact with the cylinder 14.

  A sub pressurizing chamber 122 is formed by the inner wall of the accommodating portion 15 of the cylinder 14, the stepped surface 132 of the plunger 13 and the outer wall of the small diameter portion 131, and the plunger stopper 80. The auxiliary pressurizing chamber 122 communicates with a gap of several μm provided between the cylinder 14 and the plunger 13 for sliding and cooling the plunger 13. The auxiliary pressurizing chamber 122 communicates with the annular fuel passage 123 formed between the connecting portion 56 of the holding member 52 and the annular portion 16 of the cylinder 14 through the groove 84 of the plunger stopper 80. The annular fuel passage 123 passes through a hole 162 communicating with the annular portion 16 in the axial direction, and communicates with a housing fuel reservoir 124 formed between the annular portion 16 and the housing 11. The housing fuel reservoir 124 communicates with the first fuel chamber 110 provided in the supply passage 100 via the communication passage 106 formed in the housing 11. As a result, the fuel pressure in the auxiliary pressurizing chamber 122 becomes substantially equal to the fuel pressure in the supply passage 100.

  A flange 40 is provided on the internal combustion engine 200 side of the housing 11. The high pressure pump 10 is attached to the internal combustion engine 200 by inserting a screw (not shown) into the hole 45 provided in the attachment portion 42 of the flange 40 and screwing the screw into the internal combustion engine 200.

Next, the damper device 5 will be described.
As shown in FIG. 1, the housing 11 is provided with a damper housing 111 that is recessed toward the cylinder 14 on the opposite side of the cylinder 14. The damper housing 111 opens to the outside of the housing 11. The lid member 12 closes the opening of the damper housing 111. A first fuel chamber 110 is formed between the damper housing 111 and the lid member 12.
The first fuel chamber 110 communicates with the sub pressurization chamber 122 through the communication passage 106. The first fuel chamber 110 communicates with the pressurizing chamber 121 through the supply passage 100. The first fuel chamber 110 communicates with a fuel inlet (not shown) through a passage (not shown).
Fuel pressure pulsation is generated in the supply passage 100 by the fuel sucked from the supply passage 100 to the pressurization chamber 121 side by the reciprocating movement of the plunger 13 and the fuel discharged from the pressurization chamber 121 to the supply passage 100 side.

A pulsation damper 210 is accommodated in the first fuel chamber 110.
The pulsation damper 210 is composed of two metal diaphragms and a cover member 211, and a gas having a predetermined pressure is sealed inside. The pulsation damper 210 reduces the fuel pressure pulsation in the first fuel chamber 110 by elastically deforming the two metal diaphragms according to the pressure change in the first fuel chamber 110.
The cover member 211 restricts the displacement of the two metal diaphragms in the direction away from each other, and reduces the stress amplitude of the metal diaphragm. A plurality of mounting portions 212 extending radially outward from the cover member 211 are connected to the inner wall of the damper housing 111. Thereby, the pulsation damper 210 is installed in the first fuel chamber 110.

Next, the suction valve unit 30 will be described.
The suction valve unit 30 is provided in the radially outward direction of the pressurizing chamber 121. The supply passage 100 formed in the intake valve portion 30 is referred to as an intake fuel reservoir 101.
The valve body 31 is accommodated on the pressurized chamber 121 side of the intake fuel reservoir 101. A tapered valve seat 34 is formed inside the valve body 31.
The suction valve 35 is disposed on the pressure chamber 121 side of the valve seat 34. The suction valve 35 reciprocates while being guided by an inner wall of a hole provided in the valve body 31. The valve seat formed on the valve seat 34 side of the intake valve 35 can be seated on and separated from the valve seat 34 of the valve body 31.

A stopper 39 is fixed to the pressure chamber 121 side of the suction valve 35. This stopper 39 restricts the movement of the intake valve 35 in the valve opening direction (right direction in FIG. 1). A first spring 21 is provided between the inside of the stopper 39 and the suction valve 35. The first spring 21 biases the suction valve 35 in the direction in which the suction valve 35 is seated on the valve seat 34, that is, in the valve closing direction.
The stopper 39 is formed with a plurality of inclined passages 104 that are inclined with respect to the axis of the stopper 39 in the circumferential direction.

Next, the electromagnetic drive unit 70 will be described.
The electromagnetic drive unit 70 includes a coil 71, a fixed core 72, a movable core 73, a connection member 75, and the like.
The connection member 75 is made of a magnetic material and closes the intake fuel reservoir 101 of the intake valve unit 30. The connection member 75 holds the fixed core 72 and the connector 77.
A fixed core 72 made of a magnetic material is provided on the side of the connecting member 75 opposite to the pressurizing chamber 121. A cylindrical member 79 made of a non-magnetic material prevents a magnetic short circuit between the fixed core 72 and the connection member 75.
A resin spool 78 is provided on the radially outer side of the fixed core 72. A coil 71 is wound around the outer diameter of the spool 78.

The movable core 73 is made of a magnetic material, and is accommodated in an accommodation chamber provided on the fixed core 72 side of the connection member 75 so as to be capable of reciprocating in the axial direction.
A guide tube is attached to the inner wall of the hole provided in the center of the connecting member 75.
The needle 38 is formed in a substantially cylindrical shape and reciprocates while being guided by the inner wall of the guide cylinder. The needle 38 is installed so that one end thereof is assembled integrally with the movable core 73 and the other end is in contact with the end surface of the suction valve 35 on the electromagnetic drive unit 70 side.

A second spring 22 is provided between the fixed core 72 and the movable core 73. The second spring 22 biases the movable core 73 toward the suction valve 35 with a force stronger than the force that the first spring 21 on the stopper 39 side biases the suction valve 35 in the valve closing direction.
When the coil 71 is not energized, the movable core 73 is not attracted to the fixed core 72 and is separated from each other by the elastic force of the second spring 22. For this reason, the needle 38 integral with the movable core 73 moves to the suction valve 35 side, and the suction valve 35 is opened when the end surface of the needle 38 presses the suction valve 35.
When the coil 71 is energized, magnetic flux flows through a magnetic circuit formed by the fixed core 72, the movable core 73, the connection member 75, and the like, and the movable core 73 is attracted to the fixed core 72. The needle 38 integral with the movable core 73 moves to the fixed core 72 side, and the needle 38 releases the pressing force on the suction valve 35. Therefore, the suction valve 35 can be closed by the elastic force of the first spring 21.

Next, the discharge valve unit 90 will be described.
A discharge passage 105 communicates the pressurizing chamber 121 and the fuel outlet 91.
The discharge valve 92 is formed in a bottomed cylindrical shape and is accommodated in the discharge passage 105 so as to be reciprocally movable. The discharge valve 92 closes the discharge passage 105 by sitting on a valve seat 95 formed on the inner wall of the discharge passage 105, and opens the discharge passage 105 by separating from the valve seat 95.
A cylindrical regulating member 93 is provided on the fuel outlet 91 side of the discharge valve 92. The restricting member 93 restricts the movement of the discharge valve 92 toward the fuel outlet 91.
One end of the spring 94 is in contact with the regulating member 93 and the other end is in contact with the discharge valve 92. The spring 94 urges the discharge valve 92 to the valve seat 95 side. Depending on the installation position of the restricting member 93, the spring load of the spring 94 can be set and the valve opening pressure of the discharge valve 92 can be adjusted.

The pressure of the fuel in the pressurizing chamber 121 rises, and the force received by the discharge valve 92 from the fuel on the pressurizing chamber 121 side is greater than the sum of the spring force of the spring 94 and the force received from the fuel on the downstream side of the valve seat 95. As a result, the discharge valve 92 is separated from the valve seat 95. As a result, the fuel is discharged from the fuel outlet 91 through the discharge passage 105 from the pressurizing chamber 121.
On the other hand, the pressure of the fuel in the pressurizing chamber 121 decreases, and the force received by the discharge valve 92 from the fuel on the pressurizing chamber 121 side is the sum of the spring force of the spring 94 and the force received from the fuel on the downstream side of the valve seat 95. When the pressure becomes smaller, the discharge valve 92 is seated on the valve seat 95. This prevents fuel on the downstream side of the valve seat 95 from flowing back into the pressurizing chamber 121.

Next, the operation of the high-pressure pump 10 will be described.
(1) Suction stroke When the plunger 13 is lowered from the top dead center toward the bottom dead center by the rotation of the camshaft 7, the volume of the pressurizing chamber 121 increases and the fuel is depressurized. The discharge valve 92 is seated on the valve seat 95 and closes the discharge passage 105.
On the other hand, the suction valve 35 moves to the pressurizing chamber 121 side against the urging force of the first spring 21 due to the pressure difference between the pressurizing chamber 121 and the supply passage 100 and is opened. At this time, since energization to the coil 71 is stopped, the movable core 73 and the needle 38 move to the pressurizing chamber 121 side by the urging force of the second spring 22. Accordingly, the needle 38 and the suction valve 35 come into contact with each other, and the suction valve 35 maintains the valve open state. As a result, fuel is sucked into the pressurizing chamber 121 from the first fuel chamber 110 through the supply passage 100.

In the suction stroke, the volume of the auxiliary pressurizing chamber 122 decreases due to the lowering of the plunger 13. Therefore, the fuel in the auxiliary pressurizing chamber 122 passes through the groove 84 of the plunger stopper 80, the annular fuel passage 123, the hole 162 of the annular portion 16 of the cylinder 14, the housing fuel reservoir 124, and the communication passage 106, and then the first fuel chamber. 110 is sent out.
Here, the cross-sectional area ratio between the large diameter portion 133 and the stepped surface 132 is approximately 1: 0.6. Therefore, the ratio of the increase in the volume of the pressurization chamber 121 to the decrease in the volume of the sub pressurization chamber 122 is also 1: 0.6. Therefore, about 60% of the fuel sucked into the pressurizing chamber 121 is supplied from the sub pressurizing chamber 122, and the remaining about 40% is sucked from the fuel inlet. Thereby, the suction efficiency of the fuel into the pressurizing chamber 121 is improved and the fuel pressure pulsation is reduced.

(2) Metering stroke When the plunger 13 rises from the bottom dead center toward the top dead center due to the rotation of the camshaft 7, the volume of the pressurizing chamber 121 decreases. At this time, since energization to the coil 71 is stopped until a predetermined time, the needle 38 and the suction valve 35 are in the open position by the urging force of the second spring 22. Thereby, the supply passage 100 is maintained in an open state. For this reason, the low-pressure fuel once sucked into the pressurizing chamber 121 is returned to the first fuel chamber 110 via the supply passage 100. Therefore, the pressure in the pressurizing chamber 121 does not increase.

In the metering stroke, the volume of the auxiliary pressurizing chamber 122 increases due to the rise of the plunger 13. Therefore, the fuel in the first fuel chamber 110 passes through the communication passage 106, the housing fuel reservoir 124, the hole 162 in the annular portion 16 of the cylinder 14, the annular fuel passage 123, and the groove 84 in the plunger stopper 80, and the sub pressurizing chamber. It flows into 122.
At this time, about 60% of the volume of the low-pressure fuel discharged from the pressurizing chamber 121 to the first fuel chamber 110 side is sucked into the sub pressurizing chamber 122 from the first fuel chamber 110. This reduces about 60% of the fuel pressure pulsation.

(3) Pressurization stroke The coil 71 is energized at a predetermined time while the plunger 13 rises from the bottom dead center toward the top dead center. Then, a magnetic attractive force is generated between the fixed core 72 and the movable core 73 by the magnetic field generated in the coil 71. When the magnetic attractive force becomes larger than the difference between the elastic force of the second spring 22 and the elastic force of the first spring 21, the movable core 73 and the needle 38 move to the fixed core 72 side (left direction in FIG. 1). As a result, the pressing force of the needle 38 against the suction valve 35 is released. The intake valve 35 moves to the valve seat 34 side by the elastic force of the first spring 21 and the force generated by the flow of low-pressure fuel discharged from the pressurizing chamber 121 to the first fuel chamber 110 side. Therefore, the suction valve 35 is seated on the valve seat 34 and the supply passage 100 is closed.

From the time when the intake valve 35 is seated on the valve seat 34, the fuel pressure in the pressurizing chamber 121 increases as the plunger 13 rises toward the top dead center. When the force that the fuel pressure in the pressurizing chamber 121 acts on the discharge valve 92 becomes larger than the force that the fuel pressure in the discharge passage 105 acts on the discharge valve 92 and the biasing force of the spring 94, the discharge valve 92 opens. Thereby, the high-pressure fuel pressurized in the pressurizing chamber 121 is discharged from the fuel outlet 91 via the discharge passage 105.
Note that energization of the coil 71 is stopped during the pressurization stroke. Since the force that the fuel pressure in the pressurizing chamber 121 acts on the suction valve 35 is larger than the urging force of the second spring 22, the suction valve 35 maintains the closed state.

The high-pressure pump 10 repeats the steps (1) to (3) to pressurize and discharge a necessary amount of fuel to the internal combustion engine 200.
If the timing of energizing the coil 71 is advanced, the time of the metering stroke is shortened and the time of the pressurizing stroke is lengthened. As a result, the amount of fuel returned from the pressurizing chamber 121 to the supply passage 100 decreases, and the amount of fuel discharged from the discharge passage 105 increases.
On the other hand, if the timing of energizing the coil 71 is delayed, the time of the metering stroke becomes longer and the time of the discharge stroke becomes shorter. Thereby, the fuel returned from the pressurizing chamber 121 to the supply passage 100 increases, and the fuel discharged from the discharge passage 105 decreases.
Thus, by controlling the timing of energizing the coil 71, the amount of fuel discharged from the high-pressure pump 10 can be controlled to the amount required by the internal combustion engine 200.

In the present embodiment, the following effects are obtained.
(1) In the present embodiment, the cylinder 14 integrally forms the accommodating portion 15, the annular portion 16 and the insertion portion 17. Thereby, it becomes possible to form the accommodating part 15 and the insertion part 17 coaxially by cutting, for example. For this reason, the plunger 13 accommodated in the accommodating portion 15 and the seal member 50 connected to the insertion portion 17 can be provided coaxially. Therefore, wear of the seal member 50 or the plunger 13 is suppressed, and the pressure resistance of the seal member 50 can be increased.
(2) In the present embodiment, in the fuel seal element 51, the Teflon ring 53 on the inner diameter side held by the holding portion 57 is in fluid-tight sliding contact with the outer wall in the radially outer direction of the plunger 13. In the fuel seal element 51, the sealing performance of the inner wall in the radial direction is highly maintained by the Teflon ring 53, and the sealing performance of the outer wall in the radial direction is maintained by the O-ring 54. Also, the plunger stopper 80 prevents the O-ring 54 from swelling due to the influence of alcohol-added fuel or the like and affecting the tightening force of the fuel seal element 51. This is because the space when the O-ring swells can be regulated by the plunger stopper 80, and therefore the swelling amount can be suppressed to a predetermined value. Therefore, the wear of the fuel seal element 51 or the plunger 13 is suppressed without increasing the tightening force of the fuel seal element 51, and the pressure resistance of the fuel seal element 51 can be increased.

(Second Embodiment)
A high-pressure pump according to a second embodiment of the present invention is shown in FIG. Hereinafter, in a plurality of embodiments, the same numerals are given to the composition substantially the same as a 1st embodiment mentioned above, and explanation is omitted. In the present embodiment, the communication passage 107 communicates between the housing fuel reservoir 124 and the intake fuel reservoir 101 of the intake valve portion 30. As a result, the fuel in the auxiliary pressurizing chamber 122 circulates with the intake fuel reservoir 101 without passing through the first fuel chamber 110. For this reason, it is possible to reduce the fuel flowing through the supply passage 100 communicating between the first fuel chamber 110 and the intake fuel reservoir 101 by the volume of the sub-pressurization chamber 122. Therefore, the inner diameter of the supply passage 100 can be reduced and the size of the high-pressure pump can be reduced.

(Third embodiment)
A high-pressure pump according to a third embodiment of the present invention is shown in FIG. In the present embodiment, an annular housing cover 112 that extends substantially parallel to the axis of the cylinder 14 is provided between the housing 11 and the flange 40. The housing cover 112 is made of metal, for example. The housing cover 112 includes a cylindrical portion 114 joined to a step 117 provided on the housing 11, a stepped portion 115 extending radially inward from an edge on the axial flange side of the cylindrical portion 114, and an inner edge of the stepped portion 115. To the axial direction internal combustion engine 200 side. The joint 116 is fitted to the step 161 of the cylinder 14. The flange 40 is joined in the radially outward direction of the joining portion 116.
A first heat insulating space 150 is formed between the annular portion 16 of the cylinder 14 and the housing 11 on the radially inner side of the housing cover 112. For example, air is sealed in the first heat insulating space 150. A fuel pipe 108 connects the annular portion 16 of the cylinder 14 and the communication passage 106 of the housing 11.
A resin coating may be applied to the housing cover 112. Thereby, it can suppress that the operation sound of a high pressure pump resonates with the housing cover 112, and can reduce an operation sound. Moreover, the heat insulation effect of the 1st heat insulation space 150 can be improved.
In the present embodiment, the first heat insulating space 150 can suppress the heat of the internal combustion engine 200 from being transferred to the fuel in the housing 11 via the flange 40 or the housing cover 112.
In the present embodiment, it is possible to reduce material loss due to cutting of the housing 11 when forming the first heat insulation space 150. Therefore, the manufacturing cost of the housing 11 can be reduced.

(Fourth embodiment)
A high-pressure pump according to a fourth embodiment of the present invention is shown in FIG. In the present embodiment, the housing cover 112 includes a cylindrical tube portion 114 and does not have the step portion 115 and the joint portion 116. The housing cover 112 is made of, for example, resin.
One side of the housing cover 112 is joined to a step 117 provided on the housing 11, and the other side is joined to a protrusion 47 extending from the flange 40 toward the axial housing 11 side.
In the present embodiment, the cost of the housing cover 112 can be reduced and the heat insulating effect of the first heat insulating space 150 can be enhanced.

(Fifth embodiment)
A high-pressure pump according to a fifth embodiment of the present invention is shown in FIG. In the present embodiment, the fuel pipe 108 that connects the annular portion 16 of the cylinder 14 and the communication path 106 of the housing 11 is not provided. The first heat insulation space 150 communicates with the first fuel chamber 110 and the sub pressurization chamber 122. Thereby, the fuel flows into the first heat insulation space 150 in the first fuel chamber 110 and the sub pressurization chamber 122.
In the present embodiment, the first fuel chamber 110, the first heat insulation space 150, and the sub-pressurization chamber 122 communicate with each other, so that the volume for storing the fuel that communicates with the supply passage 100 is increased. Therefore, the fuel pressure pulsation generated in the supply passage 100 can be reduced, and the suction efficiency can be improved.
The housing 11 may be formed with a communication passage 107 that allows the first fuel chamber 110 and the intake fuel reservoir 101 to communicate with each other.

(Sixth embodiment)
A high-pressure pump according to a sixth embodiment of the present invention is shown in FIG. In the present embodiment, the holding member 52 of the seal member 50 is configured such that the fixing portion 55, the connecting portion 56, and the holding portion 57 have substantially the same plate thickness. The holding member 52 is formed with a fixing portion 55, a connection portion 56, and a holding portion 57, for example, by pressing. A second heat insulating space 140 is formed between the holding portion 57 of the holding member 52 and the oil seal outer ring 62. For example, air is sealed in the second heat insulation space 140.
When the high pressure pump is installed in the high pressure pump mounting hole 201 of the internal combustion engine 200, the oil of the internal combustion engine 200 is applied to the oil seal 60. Further, the heat of the internal combustion engine 200 is transferred to the oil seal 60. In this case, heat transfer from the internal combustion engine 200 from the oil seal 60 to the fuel in the sub pressurization chamber 122 is suppressed by the second heat insulation space 140. Therefore, the temperature rise of the fuel flowing from the sub pressurization chamber 122 to the supply passage 100 is suppressed, and the generation of vapor in the supply passage 100 can be suppressed. As a result, the occurrence of vapor lock in the high-pressure pump is suppressed, and problems such as poor startability can be suppressed.
In the present embodiment, since the holding member 52 can be formed by press working, the processing cost of the holding member 52 can be reduced.

(Seventh embodiment)
A high-pressure pump according to a seventh embodiment of the present invention is shown in FIGS. In the present embodiment, the cylinder 14 includes a thick part 141 provided on the pressurizing chamber 121 side, a middle part 142 having an outer diameter smaller than the outer diameter of the thick part 141, and an outer part than the middle part 142. The thin portion 143 has a small diameter. The outer wall of the thick portion 141 is press-fitted into the housing 11.
The holding member 52 constituting the seal member 50 is formed in a substantially bottomed cylindrical shape, and the small diameter portion 131 of the plunger 13 is inserted into the bottom portion thereof. One side of the holding member 52 in the axial direction is connected to the outer wall of the inner portion 142 of the cylinder 14, and the other side holds the fuel seal element 51.
A second heat insulating space 140 is formed between the holding member 52 and the oil seal outer ring 62. For example, air is sealed in the second heat insulation space 140. The second heat insulation space 140 suppresses heat from the internal combustion engine 200 from being transferred from the oil seal 60 to the sub pressurization chamber 122.

The flange 40 includes a second insertion portion 41 that is inserted into a high-pressure pump attachment hole 201 provided in the internal combustion engine 200, and an attachment portion 42 that extends radially outward from the axial housing 11 side of the second insertion portion 41. Have. The housing 11 is fixed to a cylindrical fitting portion 43 that protrudes from the attachment portion 42 of the flange 40 toward the pressurizing chamber 121.
An O-ring 44 is fitted in a groove provided on the radial outer wall of the second insertion portion 41 of the flange 40. This O-ring 44 prevents engine oil from leaking from between the high-pressure pump mounting hole 201 and the second insertion portion to the outside air side, and prevents water and the like from entering the internal combustion engine 200 from the outside air side.
A holding member 52 is inserted into a circular hole 48 provided in the plate thickness direction of the attachment portion of the flange 40. An O-ring 49 is fitted in a groove provided on the inner wall of the circular hole 48 of the flange 40. The O-ring 49 prevents the fuel from leaking from the housing fuel reservoir 124 formed between the flange 40 and the housing 11 to the internal combustion engine 200 side, and the engine oil of the internal combustion engine 200 enters the housing fuel reservoir 124. Prevent intrusion.

  A sub pressurizing chamber 122 is formed by the thin wall portion 143 of the cylinder 14, the stepped surface 132 of the plunger 13, the outer wall of the small diameter portion 131, the plunger stopper 80, and the inner wall of the holding member 52. The sub pressurizing chamber 122 communicates with a gap provided between the cylinder 14 and the plunger 13. The auxiliary pressurizing chamber 122 passes through a hole 144 communicating with the thin portion 143 of the cylinder 14 in the radial direction, and is a cylindrical cylinder external fuel formed between the thin portion 143 of the cylinder 14 and the inner wall of the holding member 52. It communicates with the passage 126. The cylinder external fuel passage 126 passes through a hole 58 communicating in the radial direction of the holding member 52, and communicates with a housing fuel reservoir 124 formed between the attachment portion of the flange 40 and the housing 11. The housing fuel reservoir 124 passes through the communication passage 106 formed in the housing 11 and communicates with the first fuel chamber 110 provided in the supply passage 100. As a result, the fuel pressure in the auxiliary pressurizing chamber 122 becomes substantially equal to the fuel pressure in the supply passage 100.

In the present embodiment, the holding member 52 constituting the seal member 50 has one side in the axial direction connected to the outer wall of the inner wall 142 of the cylinder 14 and the other side holding the fuel seal element 51. Thereby, the plunger 13 accommodated in the accommodating portion 15 and the fuel seal element 51 retained by the retaining member 52 can be provided coaxially. Therefore, wear of the fuel seal element 51 and the plunger 13 is suppressed, and the pressure resistance of the seal member 50 can be increased.
In the present embodiment, in the fuel seal element 51, the sealing performance of the inner wall in the radially inner direction is highly maintained by the Teflon ring 53, and the sealing performance of the outer wall in the radially outer direction is maintained by the O-ring 54. Also, the plunger stopper 80 prevents the O-ring 54 from swelling due to the influence of alcohol-added fuel or the like and affecting the tightening force of the fuel seal element 51. Therefore, the wear of the fuel seal element 51 or the plunger 13 is suppressed without increasing the tightening force of the fuel seal element 51, and the pressure resistance of the fuel seal element 51 can be increased.
In the present embodiment, the heat of the internal combustion engine 200 is suppressed from being transferred from the oil seal 60 to the sub pressurizing chamber 122 by the second heat insulating space 140. Therefore, the temperature rise of the fuel flowing from the sub pressurization chamber 122 to the supply passage 100 is suppressed, and the generation of vapor in the supply passage 100 can be suppressed. As a result, it is possible to suppress the vapor lock from occurring in the high pressure pump.
Moreover, in this embodiment, the processing cost of the cylinder 14 can be reduced compared with the 1st-6th embodiment mentioned above.

(Eighth embodiment)
FIG. 14 shows a high-pressure pump according to the eighth embodiment of the present invention. In the present embodiment, the communication passage 107 communicates between the housing fuel reservoir 124 and the intake fuel reservoir 101 of the intake valve portion 30. As a result, the fuel in the auxiliary pressurizing chamber 122 circulates with the intake fuel reservoir 101 without passing through the first fuel chamber 110. For this reason, it is possible to reduce the fuel flowing through the supply passage 100 communicating between the first fuel chamber 110 and the intake fuel reservoir 101 by the volume of the sub-pressurization chamber 122. Therefore, the inner diameter of the supply passage 100 can be reduced and the size of the high-pressure pump can be reduced.

(Ninth embodiment)
A high-pressure pump according to a ninth embodiment of the present invention is shown in FIGS. In the present embodiment, an annular housing cover 112 that extends substantially parallel to the axis of the cylinder 14 is provided between the housing 11 and the flange 40. The housing cover 112 is made of, for example, resin. One side of the housing cover 112 is joined to a step 117 provided on the housing 11, and the other side is joined to a protrusion 47 extending from the flange 40 toward the axial housing 11 side.
A first heat insulating space 150 is formed between the flange 40 and the housing 11 on the radially inner side of the housing cover 112. For example, air is sealed in the first heat insulating space 150.

A fuel pipe 108 connects the hole 58 communicating in the radial direction of the holding member 52 and the communication path 106 of the housing 11. As a result, the cylinder external fuel passage 126 and the communication passage 106 communicate with each other. Therefore, the fuel flows between the sub pressurization chamber 122 and the first fuel chamber 110, and the fuel pressure in the sub pressurization chamber 122 is substantially equal to the fuel pressure in the supply passage 100.
In the present embodiment, the first heat insulating space 150 can suppress the heat of the internal combustion engine 200 from being transferred to the fuel in the housing 11 via the flange 40 or the housing cover 112.
In the present embodiment, heat transfer of the internal combustion engine 200 from the oil seal 60 to the fuel in the sub pressurization chamber 122 can be suppressed by the second heat insulating space 140.
In the present embodiment, it is possible to reduce material loss due to cutting of the housing 11 when forming the first heat insulation space 150. Therefore, the manufacturing cost of the housing 11 can be reduced.

(10th Embodiment)
FIG. 17 shows a high-pressure pump according to the tenth embodiment of the present invention. In the present embodiment, the cylinder 14 is formed shorter in the axial direction than in the first to ninth embodiments described above. The plunger 13 is also formed short in the axial direction. Further, the spring locking portion 46 of the flange 40 is provided closer to the pressurizing chamber 121 than the mounting portion 42.
In the present embodiment, the physique in the axial direction of the high-pressure pump can be made smaller than in the first to ninth embodiments described above.
Moreover, in this embodiment, the mass of the plunger 13 becomes small. Therefore, since the elastic force of the spring can be reduced, the driving force of the camshaft 7 that drives the plunger 13 can be reduced.

(Other embodiments)
In the above embodiments, the plunger 13 is formed with the large-diameter portion 133 and the small-diameter portion 131 so that the volume of the auxiliary pressurizing chamber 122 can be varied by the reciprocating movement of the plunger 13. On the other hand, in the present invention, the plunger may have the same outer diameter in the axial direction, and the auxiliary pressurizing chamber may be configured as a leak return chamber that stores fuel leaking from the gap between the cylinder and the plunger.
The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... Fuel supply system 7 ... Camshaft 10 ... High pressure pump 11 ... Housing 13 ... Plunger 14 ... Cylinder 15 ... Storage part 16 ... Annular part 17 ... Insertion section 30 ... Suction valve section 40 ... Flange 50 ... Seal member 51 ... Fuel seal element (seal member)
52 ... Holding member (seal member)
60 ... Oil seal (seal member)
61 ... Oil seal element (seal member)
62 ・ ・ ・ Oil seal outer ring (seal member)
80 ... Plunger stopper 90 ... Discharge valve portion 100 ... Supply passage 106 ... Communication passage 114 ... Discharge passage 121 ... Pressurization chamber 122 ... Sub pressurization chamber 131 ... Small diameter portion 133 ... large diameter portion 200 ... internal combustion engine 201 high pressure pump mounting hole

Claims (6)

A high pressure pump driven by a camshaft of an internal combustion engine,
A plunger that reciprocates in the axial direction by rotation of the camshaft;
A housing having a pressurizing chamber in which fuel is pressurized by the plunger;
A suction valve portion that is provided in a supply passage for supplying fuel to the pressurizing chamber and opens and closes the supply passage;
A discharge valve portion that is provided in a discharge passage for discharging fuel pressurized in the pressurizing chamber and opens and closes the discharge passage;
An accommodating portion for accommodating the plunger in the housing so as to be capable of reciprocating; an annular portion extending radially outward from a side opposite to the pressurizing chamber of the accommodating portion; and an axial pressure chamber from an outer edge of the annular portion A cylinder that integrally has an insertion portion that extends to the opposite side and can be inserted into a high-pressure pump mounting hole provided with the camshaft of the internal combustion engine;
It is formed in a substantially annular shape, and the outer wall in the radially outward direction is liquid-tightly connected to the inner wall of the insertion portion of the cylinder, and the inner wall in the radially inward direction is exposed from the accommodating portion of the cylinder to the side opposite to the pressurizing chamber. A seal member that is in fluid-tight sliding contact with the outer wall of the plunger in the radially outward direction;
A flange that can be attached to an outer wall of the internal combustion engine located outside the diameter of the high-pressure pump attachment hole;
An annular housing cover that connects the housing and the flange and has a cylindrical first heat insulating space capable of suppressing heat transfer from the internal combustion engine to the cylinder radially inward;
An annular plunger stopper provided between the accommodating portion of the cylinder and the seal member, and having an insertion hole through which the plunger is inserted;
With
A sub-pressurization chamber is provided between the plunger stopper and the plunger,
The supply passage is provided with a first fuel chamber for reducing fuel pressure pulsation caused by fuel sucked into the pressurizing chamber and fuel discharged from the pressurizing chamber,
The high-pressure pump, wherein the first heat insulation space communicates with the first fuel chamber and the sub pressurization chamber . The sealing member is
A fuel seal element formed in a cylindrical shape and in fluid-tight sliding contact with an outer wall in a radially outward direction of the plunger exposed on the opposite side of the pressurizing chamber from the accommodating portion of the cylinder;
An outer wall in a radially outward direction is liquid-tightly connected to an inner wall of the insertion portion of the cylinder, and a holding member in which the inner wall in the radially inward direction holds the fuel seal element;
Oil that is formed in a substantially cylindrical shape, one side in the axial direction is connected to the holding member, and the other side is in fluid-tight sliding contact with the outer wall in the radially outward direction of the plunger on the side opposite to the pressurizing chamber of the holding member The high-pressure pump according to claim 1, further comprising a seal. The secondary pressure chamber is communicated with the gap between the plunger and the housing portion of the cylinder, a high pressure pump according to claim 2, wherein the benzalkonium through communication with the supply passage through the communication passage. The plunger, the large-diameter portion provided on the pressurizing chamber side, and the insertion hole of the plunger stopper outside diameter is smaller than the large diameter portion at the side opposite to the pressure chamber of the large diameter portion Having a small diameter part to be inserted,
4. The high-pressure pump according to claim 3, wherein the sub-pressurization chamber sucks and discharges fuel in the supply passage through the communication passage by reciprocating movement of the plunger. The communication passage, high pressure pump according to claim 3 or 4, characterized in that communicating the auxiliary pressure chamber and the intake fuel reservoir that is formed in the suction valve unit constituting a part of the supply passage. The oil seal is
An oil seal element that is in fluid-tight sliding contact with the outer wall in the radially outward direction of the plunger on the opposite side of the pressurizing chamber from the holding member;
An oil seal outer ring that is formed in a substantially cylindrical shape, one side in the axial direction is connected to the holding member, and the other side holds the oil seal element;
The cylindrical second heat insulating space capable of suppressing heat transfer from the internal combustion engine to the auxiliary pressurizing chamber is provided between the oil seal outer ring and the holding member. The high pressure pump according to any one of 2 to 5 .

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