JP5892397B2 - Pulsation damper - Google Patents

Description

  The present invention relates to a pulsation damper that reduces pressure pulsation of fuel.

In recent years, a variable fuel pressure system that variably controls fuel pressure pumped from a fuel tank by a low-pressure pump and supplied to the high-pressure pump is employed in a fuel supply system that supplies fuel to an internal combustion engine. In this variable fuel pressure system, when the rotation speed or load of the internal combustion engine is lower than that during normal operation, the fuel pressure supplied from the low pressure pump to the high pressure pump is lowered, and the power consumption of the low pressure pump is reduced. On the other hand, when the internal combustion engine is started, the fuel pressure supplied from the low pressure pump to the high pressure pump is increased to prevent the occurrence of problems such as a start failure due to vapor in the fuel.
In the fuel supply system, a damper device that reduces fuel pressure pulsation generated in the fuel passage is provided. The damper device is provided with a pulsation damper composed of two diaphragms.
In Patent Document 1, a pressure receiving chamber through which fuel flows is provided between two diaphragms. The two diaphragms repeat the operation of moving the two diaphragms toward and away from each other by the fuel pressure pulsation of the pressure receiving chamber (hereinafter, the operation of the diaphragm is referred to as “amplitude operation”), and the pressure is received by the volume change of the pressure receiving chamber at that time. The fuel pressure pulsation of the chamber is reduced. In this damper device, two gas sealing chambers are provided on the side opposite to the pressure receiving chambers of the two diaphragms. The damper device responds to the pressure change of the fuel flowing through the pressure receiving chamber by setting the gas sealing pressures of the two gas sealing chambers to different values.
In Patent Document 2, two metal diaphragms are accommodated in the fuel chamber of the damper device (“Work Chamber 66” in Patent Document 2). In this damper device, a gas having a constant pressure is sealed between two metal diaphragms.
In patent document 3, the plate is provided between the two diaphragms which comprise a pulsation damper. The plate extends outward in the radial direction of the diaphragm and is sandwiched between a housing and a lid member that form a fuel chamber.

JP 1998-299609 A JP 2004-138071 A JP 2007-309118 A

However, in Patent Document 1, when the fuel pressure in the pressure receiving chamber is lower than the sealing pressures of the two gas sealing chambers, the amplitude operation of one or both diaphragms is small or does not operate. Further, when the fuel pressure in the pressure receiving chamber is between the sealing pressure in one gas sealing chamber and the sealing pressure in the other gas sealing chamber, the amplitude operation of one diaphragm is large, but the amplitude operation of the other diaphragm is small. Or the amplitude does not work. For this reason, we are anxious about the low pulsation suppression effect. Furthermore, when the fuel pressure in the pressure receiving chamber is higher than the sealing pressures of the two gas sealing chambers, both diaphragms are greatly displaced toward the gas sealing chamber, and there is a risk that the diaphragms will fatigue early.
In Patent Document 2, since the gas filling pressure between two diaphragms is a constant pressure, when the fuel pressure in the fuel chamber is lower than the gas filling pressure, the amplitude operation of both diaphragms is small or does not operate. Further, when the fuel pressure in the fuel chamber is higher than the gas charging pressure, the two diaphragms may be displaced in a direction approaching each other, and the insides of the center portions of the two diaphragms may come into contact with each other. At this time, there is a possibility that minute scratches may occur on the diaphragm. For this reason, stress is concentrated starting from the scratches and the metal inclusions contained in the diaphragm material, and there is a concern that the diaphragm may be damaged early because of its fatigue strength.
In Patent Document 3, there is a concern that the pulsation damper may be enlarged if the distance between the diaphragm and the plate is increased in order to avoid contact between the diaphragm and the plate when the two diaphragms are displaced in the approaching direction. Is done.
The present invention has been made in view of the above problems, and provides a pulsation damper capable of obtaining a high pulsation reduction effect in response to an environment in which the fuel pressure supplied to the fuel chamber changes greatly. With the goal.

In order to solve the above problems, a pulsation damper according to the present invention includes a first diaphragm, a second diaphragm, and an elastic member.
The first diaphragm has a first movable part that can be elastically deformed by the fuel pressure pulsation of the fuel chamber, and an annular first outer edge part provided at the outer edge of the first movable part.
The second diaphragm forms a sealed space in which a gas of a predetermined pressure is sealed together with the first movable portion, and is elastically deformable by the fuel pressure pulsation of the fuel chamber, and an annular provided at the outer edge of the second movable portion. Having a second outer edge.
The cylindrical elastic member provided in the sealed space and having a hole at a position corresponding to the central portion of the first movable portion and the second movable portion has the first movable portion and the second movable portion formed by the fuel pressure in the fuel chamber. When displacing in the direction approaching each other, one or the other of both ends in the axial direction of the elastic member is in contact with the outer edge of the first movable part or the second movable part, thereby regulating the displacement of the outer edge, and the first movable part And the displacement of the center part of the 2nd movable part is permitted.

Thereby, when a 1st movable part and a 2nd movable part displace to the direction which mutually approaches, it can prevent that a 1st movable part and a 2nd movable part contact.
In addition, the first movable portion and the second movable portion can exhibit a pulsation suppressing effect by the amplitude operation of the central portion on the inner side of the outer edge.

Sectional drawing which shows the pulsation damper by 1st Embodiment of this invention. FIG. 2 is a plan view from the direction of the arrow II in FIG. 1 excluding the first diaphragm. The schematic diagram of the fuel supply system of the internal combustion engine in which the pulsation damper by 1st Embodiment of this invention is used. Sectional drawing of a high-pressure pump provided with the pulsation damper by 1st Embodiment of this invention. Explanatory drawing of operation | movement of the pulsation damper by 1st Embodiment of this invention. Sectional drawing which shows the pulsation damper by 2nd Embodiment of this invention. Sectional drawing which shows the pulsation damper by 3rd Embodiment of this invention. FIG. 8 is an arrow view in the VIII direction in FIG. 7 and is a plan view excluding the first diaphragm. Sectional drawing which shows the pulsation damper by 4th Embodiment of this invention. FIG. 10 is a plan view from the direction of the arrow X in FIG. 9 excluding the first diaphragm. Sectional drawing which shows the pulsation damper by 5th Embodiment of this invention. FIG. 12 is a plan view from the direction of the arrow XII in FIG. 11 excluding the first diaphragm. Sectional drawing which shows the pulsation damper by 6th Embodiment of this invention. FIG. 14 is a plan view from the direction of the arrow XIV in FIG. 13 excluding the first diaphragm. Sectional drawing which shows the pulsation damper by 7th Embodiment of this invention. Explanatory drawing of operation | movement of the pulsation damper by 7th Embodiment of this invention. Sectional drawing which shows the pulsation damper by 8th Embodiment of this invention. Sectional drawing which shows the pulsation damper by 9th Embodiment of this invention. Sectional drawing which shows the pulsation damper by 10th Embodiment of this invention. The arrow view of the XX direction of FIG. Sectional drawing of a high pressure pump provided with the pulsation damper by 10th Embodiment of this invention. Explanatory drawing of operation | movement of the pulsation damper by 10th Embodiment of this invention. The characteristic view of the pulsation damper by 10th Embodiment of this invention. The characteristic view of the pulsation damper of a comparative example. Sectional drawing which shows the pulsation damper by 11th Embodiment of this invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 3 shows a fuel supply system for an internal combustion engine using the pulsation damper according to the first embodiment of the present invention. The fuel supply system 1 includes a fuel tank 2, a low pressure pump 3, a high pressure pump 10, a delivery pipe 4, a damper device 5, and the like.
In the fuel supply system, the fuel in the fuel tank 2 is pumped up by the low pressure pump 3, passes through the low pressure fuel pipe 101, and is supplied to the high pressure pump 10. In the fuel supply system 1 of the present embodiment, a variable fuel pressure system that variably controls the fuel pressure supplied to the high-pressure pump 10 is employed. This variable fuel pressure system controls the current supplied from the controller 8 to the low pressure pump 3 when the rotational speed or load of the internal combustion engine is lower than that during normal operation, and the fuel pressure supplied from the low pressure pump 3 to the high pressure pump 10 is controlled. It is low. On the other hand, when the internal combustion engine is started, the fuel pressure supplied from the low pressure pump 3 to the high pressure pump 10 is increased.

The high pressure pump 10 pressurizes the fuel supplied from the low pressure fuel pipe 101 and pumps it to the delivery pipe 4. The high-pressure fuel stored in the delivery pipe 4 is injected into a cylinder of an internal combustion engine (not shown) by an injector 6 connected to the delivery pipe 4.
The high-pressure pump 10 includes a plunger 13 that changes the volume of the pressurizing chamber 121. The plunger 13 is driven by the camshaft 7 via the tappet 9 and pressurizes the fuel in the pressurizing chamber 121 by reciprocating in the axial direction.
The high pressure pump 10 opens the suction valve portion 30 until a predetermined time during which the plunger 13 moves from the bottom dead center to the top dead center, and discharges the fuel in the pressurizing chamber 121 to the supply passage 100 on the low pressure pump 3 side. . When the electromagnetic drive unit 70 is energized from the controller 8 at a predetermined time, the intake valve unit 30 is closed. Thereby, the amount of fuel pressure-fed from the pressurizing chamber 121 to the delivery pipe 4 via the discharge valve portion 90 is determined.
The damper device 5 is provided on the low pressure pump 3 side of the suction valve unit 30. A pulsation damper 50 is installed in the fuel chamber 110 of the damper device 5. The pulsation damper 50 reduces fuel pressure pulsation caused by the fuel sucked into the pressurization chamber 121 from the supply passage 100 in the suction process and the fuel discharged from the pressurization chamber 121 into the supply passage 100 in the metering process.

Next, the configuration and operation of the high-pressure pump 10 including the pulsation damper 50 will be described with reference to FIG.
The high-pressure pump 10 includes a pump housing 11, a plunger 13, a damper device 5, a suction valve unit 30, an electromagnetic drive unit 70, a discharge valve unit 90, and the like.
The pump housing 11 and the plunger 13 will be described.
A cylindrical cylinder 14 is provided in the pump housing 11. A plunger 13 is accommodated in the cylinder 14 so as to be capable of reciprocating in the axial direction. One end of the plunger 13 is provided so as to face the pressurizing chamber 121 formed in the deep part of the cylinder 14. A spring seat 18 is attached to the other end of the plunger 13. A spring 19 is provided between the spring seat 18 and the oil seal holder 25. The spring seat 18 is urged toward the camshaft 7 by the spring 19. Thereby, when the tappet 9 contacts the cam of the camshaft 7, the plunger 13 reciprocates in the axial direction. By the reciprocating movement of the plunger 13, the volume of the pressurizing chamber 121 is changed to suck and pressurize the fuel.

Next, the damper device 5 will be described.
The damper device 5 includes a damper housing 111, a lid member 12, and a pulsation damper 50.
The pump housing 11 is provided with a damper housing 111 recessed on the cylinder side on the opposite side of the cylinder 14. The damper housing 111 and the pump housing 11 are integrally formed. The damper housing 111 opens to the outside of the pump housing 11. The lid member 12 closes the opening of the damper housing 111. A fuel chamber 110 is formed between the damper housing 111 and the lid member 12.

  The fuel chamber 110 communicates with a fuel inlet (not shown) of a high pressure pump to which fuel is supplied from the low pressure fuel pipe 101. Further, the fuel chamber 110 communicates with the pressurizing chamber 121 through the supply passage 100. For this reason, when fuel is sucked from the supply passage 100 to the pressurizing chamber 121 side by the reciprocating movement of the plunger 13 and discharged from the pressurizing chamber 121 to the supply passage 100 side, fuel pressure pulsation occurs in the fuel chamber 110.

The pulsation damper 50 accommodated in the fuel chamber 110 reduces fuel pressure pulsations in the fuel chamber 110. As shown in FIGS. 1 and 2, the pulsation damper 50 includes a first diaphragm 51, a second diaphragm 61, a plate 80 as an intermediate member, and an elastic member 40.
The first diaphragm 51 and the second diaphragm 61 are formed in a dish shape by pressing a metal plate having a high yield strength and fatigue limit, such as stainless steel.
The first diaphragm 51 includes a first movable part 52 that can be elastically deformed by the fuel pressure pulsation of the fuel chamber 110, and an annular first outer edge part 53 that is provided on the outer edge of the first movable part 52. The second diaphragm 61 also has a second movable portion 62 and a second outer edge portion 63 formed in the same thickness and shape as the first diaphragm 51.
In FIG. 2, the position of the first outer edge portion 53 is indicated by a broken line except for the first diaphragm 51.
The disc-shaped region at the center of the first movable portion 52 is referred to as a first disc portion 54, and the curved region outside the first movable portion 52 is referred to as a first curved surface portion 55. A disc-shaped region at the center of the second movable portion 62 is referred to as a second disc portion 64, and a curved region outside the second movable portion 62 is referred to as a second curved portion 65.

A plate 80 is provided between the first diaphragm 51 and the second diaphragm 61. The plate 80 is formed in a disk shape from stainless steel, for example. The plate 80 is sandwiched between the first outer edge portion 53 and the second outer edge portion 63.
The first outer edge portion 53, the second outer edge portion 63, and the plate 80 are continuously welded in the circumferential direction from the plate thickness direction. Alternatively, the outer periphery of the first outer edge portion 53 and the plate 80 are continuously welded from the radial direction to the circumferential direction, and the outer periphery of the second outer edge portion 63 and the plate 80 are continuously welded from the radial direction to the circumferential direction. . As a result, a sealed space 60 is formed between the first diaphragm 51 and the second diaphragm 61. The plate 80 extends to the sealed space 60 and extends radially outward from the first outer edge portion 53 and the second outer edge portion 63.

The air pressure in the sealed space 60 is an air pressure capable of suppressing vapor generated in the fuel above the minimum fuel pressure necessary for the operation of the internal combustion engine. By appropriately setting the plate thickness, material, outer diameter, and gas filling pressure enclosed in the sealed space 60 according to the durability or other required performances of the two diaphragms 51 and 61, the pulsation damper 50 A spring constant is set. And the pulsation frequency and pulsation damping performance which the pulsation damper 50 reduces are determined by this spring constant.
In the present embodiment, the gas filling pressure of the sealed space 60 is set corresponding to the fuel pressure in the fuel chamber 110 when the variable fuel pressure system is at a low pressure.
The first movable portion 52 and the second movable portion 62 perform an amplitude motion due to the pressure pulsation of the fuel chamber 110. As a result, the volume of the fuel chamber 110 changes, and the pressure pulsation of the fuel flowing through the fuel chamber 110 is attenuated.

The plate 80 has an annular mounting portion 81 that extends radially outward from the first outer edge portion 53 and the second outer edge portion 63. The attachment portion 81 is sandwiched and fixed between the damper housing 111 and the lid member 12. Thereby, the pulsation damper 50 is installed in the fuel chamber 110.
The attachment portion 81 of the plate 80 is provided with a flow path 82 that communicates with the plate thickness direction. Three passages 82 are provided approximately equally in the circumferential direction of the pulsation damper 50. The fuel flows through the flow path 82 through the upper and lower fuel chambers 110 of the pulsation damper 50.

  The plate 80 is provided with a circular hole that extends in the thickness direction about the axis of the pulsation damper 50. A first elastic member 41 is attached to the hole of the plate 80 from the first diaphragm 51 side, and a second elastic member 42 is attached from the second diaphragm 61 side. The first elastic member 41 and the second elastic member 42 are provided on the central axis of the pulsation damper 50. In this embodiment, the 1st elastic member 41 and the 2nd elastic member 42 are equivalent to the "elastic member" as described in a claim.

The first elastic member 41 includes a first cylindrical portion 43 and a first flange portion 44 that extends radially outward from the axial first movable portion 52 side of the first cylindrical portion 43.
The second elastic member 42 includes a second cylindrical portion 45 and a second flange portion 46 extending radially outward from the axial second movable portion 62 side of the second cylindrical portion 45.
In the assembly of the first elastic member 41, the second elastic member 42, and the plate 80, the outer wall in the radially outer direction of the first cylindrical portion 43 and the inner wall in the radially inner direction of the second cylindrical portion 45 are fitted. The first flange portion 44 contacts the surface of the plate 80 on the first diaphragm 51 side, and the second flange portion 46 contacts the surface of the plate 80 on the second diaphragm 61 side. Further, the end surface of the second cylindrical portion 45 on the first movable portion 52 side in the axial direction comes into contact with the first flange portion 44. As a result, the first elastic member 41 and the second elastic member 42 are attached to the plate 80.
The first elastic member 41 and the second elastic member 42 may be attached to the plate 80 by adhesion, pressure bonding, baking, or the like.
The 1st cylinder part 43 has the communicating hole 47 connected to an axial direction. The communication hole 47 communicates the first sealed space 601 defined by the plate 80 and the first diaphragm 51 and the second sealed space 602 defined by the plate 80 and the second diaphragm 61. Thereby, the gas sealing pressure of the 1st sealed space 601 and the 2nd sealed space 602 becomes substantially the same.

Next, the suction valve unit 30 will be described with reference to FIG.
The pump housing 11 is provided with a cylindrical portion 15 substantially perpendicular to the central axis of the cylinder 14. A supply passage 100 is formed inside the cylindrical portion 15. The supply passage 100 communicates the fuel chamber 110 and the pressurizing chamber 121.
The valve body 31 is accommodated in the supply passage 100. The valve body 31 has a small diameter cylindrical portion 32 and a large diameter cylindrical portion 33. A concave tapered valve seat 34 is formed at the bottom of the large diameter cylindrical portion 33.
The suction valve 35 is disposed inside the large diameter cylindrical portion 33 of the valve body 31. The suction valve 35 reciprocates while being guided by the inner wall of the hole 36 provided in the small diameter cylindrical portion 32. A convex tapered valve seat 37 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 inner wall of the large diameter cylindrical portion 33 of the valve body 31. The stopper 39 restricts the movement of the suction valve 35 in the valve opening direction (right direction in FIG. 4). 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 flange 75, and the like.
The flange 75 is made of a magnetic material and closes the end of the cylindrical portion 15 of the pump housing 11. The flange 75 holds the fixed core 72 and the connector 77.
A fixed core 72 made of a magnetic material is provided on the opposite side of the flange 75 from the pressurizing chamber 121. A cylindrical member 79 made of a nonmagnetic material prevents a magnetic short circuit between the fixed core 72 and the flange 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 housed in a housing chamber 74 provided on the fixed core 72 side of the flange 75 so as to be capable of reciprocating in the axial direction.
A cylindrical guide cylinder 76 is attached to the inner wall of the hole provided in the center of the flange 75.
The needle 38 is formed in a substantially cylindrical shape and reciprocates while being guided by the inner wall of the guide cylinder 76. 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 flange 75, etc., 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.

Next, the discharge valve unit 90 will be described.
A discharge passage 114 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 114 so as to be reciprocally movable. The discharge valve 92 closes the discharge passage 114 by sitting on a valve seat 95 formed on the inner wall of the discharge passage 114, and opens the discharge passage 114 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 114 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 variable volume chamber 122 will be described.
The plunger 13 has a small diameter part 131 and a large diameter part 133. A step surface 132 is formed at a connection portion between the small diameter portion 131 and the large diameter portion 133. A substantially annular plunger stopper 23 is provided so as to face the step surface 132.
The plunger stopper 23 is in contact with the pump housing 11 at the end surface on the pressurizing chamber 121 side. The plunger 13 is inserted through the central hole of the plunger stopper 23. The plunger stopper 23 has a plurality of grooves 28 extending radially outward from the center hole.
A variable volume chamber 122 is formed by a substantially annular space surrounded by the step surface 132 of the plunger 13, the outer wall of the small diameter portion 131, the inner wall of the cylinder 14, the plunger stopper 23 and the seal member 24.

  The pump housing 11 is provided with a recess 105 that is recessed in a substantially annular shape toward the pressurizing chamber 121 on the outer wall on the side where the cylinder 14 opens. An oil seal holder 25 is fitted in the recess 105. The oil seal holder 25 is fixed to the pump housing 11 with a seal member 24 interposed between the plunger stopper 23 and the oil seal holder 25. The seal member 24 includes an inner peripheral Teflon ring (“Teflon” is a registered trademark) and an outer peripheral O-ring. The seal member 24 regulates the thickness of the fuel oil film around the small diameter portion 131 and suppresses fuel leakage to the engine due to the sliding of the plunger 13. An oil seal 26 is mounted on the end of the oil seal holder 25 opposite to the pressurizing chamber 121. The oil seal 26 regulates the thickness of the oil film around the small-diameter portion 131 and suppresses oil leakage due to the sliding of the plunger 13.

  Between the oil seal holder 25 and the pump housing 11, a tubular passage 106 and an annular passage 107 communicating with the tubular passage 106 are formed. The cylindrical passage 106 communicates with the groove 28 of the plunger stopper 23. The annular passage 107 communicates with the fuel chamber 110 via a return passage 108 formed in the pump housing 11. As described above, the groove 28, the cylindrical passage 106, the annular passage 107, and the return passage 108 communicate with each other in order, so that the variable volume chamber 122 and the fuel chamber 110 communicate with each other.

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 114.
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 fuel chamber 110 via the supply passage 100.

In the suction stroke, the volume of the variable volume chamber 122 decreases due to the lowering of the plunger 13. Therefore, the fuel in the variable volume chamber 122 is sent out to the fuel chamber 110 via the cylindrical passage 106, the annular passage 107 and the return passage 108.
Here, the cross-sectional area ratio between the large diameter portion 133 and the variable volume chamber 122 is approximately 1: 0.6. Therefore, the ratio of the increase in the volume of the pressurizing chamber 121 to the decrease in the volume of the variable volume chamber 122 is also 1: 0.6. Therefore, about 60% of the fuel sucked into the pressurizing chamber 121 is supplied from the variable volume 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.
In the intake stroke, the fuel pressure in the fuel chamber 110 decreases, so the first movable portion 52 of the first diaphragm 51 and the second movable portion 62 of the second diaphragm 61 are deformed in directions away from each other.

(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 fuel chamber 110 through the supply passage 100. Therefore, the pressure in the pressurizing chamber 121 does not increase.

In the metering stroke, the volume of the variable volume chamber 122 increases as the plunger 13 moves up. Therefore, the fuel in the fuel chamber 110 flows into the variable volume chamber 122 via the return passage 108, the annular passage 107 and the cylindrical passage 106.
At this time, about 60% of the volume of the low-pressure fuel discharged from the pressurizing chamber 121 toward the fuel chamber 110 is sucked from the fuel chamber 110 into the variable volume chamber 122. This reduces about 60% of the fuel pressure pulsation.
In the metering stroke, the fuel pressure in the fuel chamber 110 increases, so the first movable portion 52 of the first diaphragm 51 and the second movable portion 62 of the second diaphragm 61 are deformed in a direction approaching each other.

(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. 3). As a result, the pressing force of the needle 38 against the suction valve 35 is released. The suction 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 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 114 acts on the discharge valve 92 and the urging 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 114.
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 steps (1) to (3) to pressurize and discharge a necessary amount of fuel to the internal combustion engine.
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 114 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 114 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 an amount required by the internal combustion engine.

Next, the operation of the pulsation damper 50 of this embodiment will be described with reference to FIG.
In the present embodiment, the pulsation damper 50 is set such that the gas filling pressure in the sealed space 60 is equal to or slightly lower than the fuel pressure in the fuel chamber 110 when the variable fuel pressure system is low.
FIG. 5A shows the state of the pulsation damper 50 when the high-pressure pump 10 is not operating, such as when the vehicle engine is stopped. At this time, since the fuel pressure in the fuel chamber 110 is substantially equal to the atmospheric pressure, the first movable portion 52 of the first diaphragm 51 and the second movable portion 62 of the second diaphragm 61 are displaced in directions away from each other. ing.

  FIG. 5B shows the operation of the pulsation damper 50 when the variable fuel pressure system is at a low pressure. The first movable portion 52 and the second movable portion 62 perform an amplitude operation with a parallel position or a state slightly closer to each other as a reference position. In FIG. 5 (B), the wave heights of the amplitude operations of the first movable part 52 and the second movable part 62 at the time of low pressure are respectively indicated by H1 and H2.

  FIG. 5C shows the operation of the pulsation damper 50 at the normal pressure of the variable fuel pressure system. The 1st movable part 52 and the 2nd movable part 62 are displaced to the direction which mutually approaches rather than the time of a low voltage | pressure. The first movable part 52 and the second movable part 62 operate in amplitude with the state as a reference position. In FIG. 5C, the wave heights of the amplitude operations of the first movable portion 52 and the second movable portion 62 at the normal pressure are shown as H3 and H4, respectively.

FIG. 5D shows the operation of the pulsation damper 50 when the variable fuel pressure system is at a high pressure. The first movable part 52 and the second movable part 62 are displaced in a direction closer to each other than during normal pressure. The first movable part 52 and the second movable part 62 are in contact with the elastic member 40. The end surface of the elastic member 40 on the first diaphragm 51 side is elastically deformed into a curved surface along the shape of the inner wall of the first diaphragm 51. The end surface of the elastic member 40 on the second diaphragm 61 side is also elastically deformed into a curved surface along the shape of the inner wall of the second diaphragm 61.
Here, the elastic member 40 has such a small elastic coefficient as to be able to perform an amplitude operation together with the first diaphragm 51 and the second diaphragm 61. For this reason, the first diaphragm 51 and the second diaphragm 61 perform an amplitude operation together with the elastic member 40 on the basis of the state in contact with the elastic member 40. In FIG. 5D, the amplitude heights of the amplitude operations of the first movable portion 52 and the second movable portion 62 at the time of high pressure are indicated by H5 and H6, respectively. The spring constant k at this time is k = k1 + k2, where the spring constant of the first diaphragm 51 or the second diaphragm 61 is k1, and the spring constant of the elastic member 40 is k2.

In the present embodiment, the following effects are obtained.
(1) In the present embodiment, the first movable part 52 and the elastic member 40 and the second movable part 62 and the elastic member 40 abut when the variable fuel pressure system is at a high pressure. Thereby, contact with the 1st movable part 52 and the 2nd movable part 62 can be avoided. Therefore, the fall of the fatigue strength of the 1st, 2nd diaphragms 51 and 61 can be suppressed, and a lifetime can be lengthened.
(2) The central portions of the first movable portion 52 and the second movable portion 62 are displaced most. Therefore, the elastic member 40 is provided on the central axes of the first diaphragm 51 and the second diaphragm 61. Therefore, the elastic member 40 can reliably prevent contact between the first movable portion 52 and the second movable portion 62.

(3) In this embodiment, the gas filling pressure in the sealed space 60 of the pulsation damper 50 is set to a value corresponding to the fuel pressure in the fuel chamber 110 when the variable fuel pressure system is low. Thereby, the pulsation damper 50 can exhibit a high pulsation reduction effect at the time of low pressure and normal pressure.
(4) In this embodiment, the elastic coefficient of the elastic member 40 is set to a small value. Accordingly, the first diaphragm 51 and the second diaphragm 61 that are in contact with the elastic member 40 perform an amplitude operation together with the elastic member 40. For this reason, the pulsation damper 50 can exhibit a high pulsation reducing effect at high pressure. Therefore, the pulsation damper 50 can obtain a high pulsation reducing effect while dealing with an environment in which the difference in fuel pressure supplied to the fuel chamber changes greatly.

(5) In this embodiment, by providing the elastic member 40 on the plate 80 without providing the elastic member 40 on the first diaphragm 51 or the second diaphragm 61, the resonance frequency of the first diaphragm 51 and the second diaphragm 61 can be reduced. The resonance frequency can be set to substantially the same value. Therefore, the pulsation damper 50 can obtain a high pulsation reduction effect by the amplitude operation of the two diaphragms 51 and 61.
(6) In this embodiment, the gas sealing pressures of the first sealed space 601 and the second sealed space 602 become substantially the same value due to the communication hole 47 of the elastic member 40. Thereby, the resonant frequency of the 1st diaphragm 51 and the resonant frequency of the 2nd diaphragm 61 can be made into the substantially same value. Accordingly, the fuel pressure pulsation effect of the two diaphragms 51 and 61 is added, so that the pulsation damper 50 can exhibit a high pulsation reduction effect.

(7) In this embodiment, when the pulsation damper 50 is installed in the fuel chamber 110, the mounting portion 81 is sandwiched between the damper housing 111 and the lid member 12, so that the first and second diaphragms 51 and 61 Excessive stress can be prevented from acting. Thereby, the pulsation reduction effect of the pulsation damper 50 can be improved.

(Second Embodiment)
A pulsation damper 50 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 elastic member 40 does not have the communication hole 47. However, for example, by welding the plate 80, the first diaphragm 51, and the second diaphragm 61 in a working chamber of the same atmospheric pressure, the gas sealing pressure of the first sealed space 601 and the gas sealing of the second sealed space 602 are performed. The pressure can be set to substantially the same value.
Also in this embodiment, the same operational effects as those of the first embodiment described above can be achieved.

(Third embodiment)
A pulsation damper 50 according to a third embodiment of the present invention is shown in FIGS.
In the present embodiment, the plate 80 is provided with a plurality of elastic members.
The elastic members are a central elastic member 410 provided on the central axis of the first diaphragm 51 and the second diaphragm 61, six annular elastic member groups 420 provided outside the diameter of the central elastic member 410, and an annular elastic member group. It consists of six outer annular elastic member groups 430 provided outside the diameter of 420. In the present embodiment, the plurality of elastic members correspond to “elastic members” recited in the claims.
The central elastic member 410, the annular elastic member group 420, and the outer annular elastic member group 430 are individually provided concentrically around the axis of the pulsation damper 50. The elastic member is attached to the plate 80 by a method such as adhesion, pressure bonding, baking, or being inserted into a hole provided in the plate 80. The elastic member on the first diaphragm 51 side of the plate 80 and the elastic member on the second diaphragm 61 side are provided at substantially the same position.

The ends of the plurality of elastic members on the first movable portion 52 side are formed along the shape of the inner wall of the first movable portion 52 when the first movable portion 52 is displaced in a direction approaching the plate 80. That is, the central elastic member 410 is formed lowest, the annular elastic member group 420 is formed higher from the plate 80, and the outer annular elastic member group 430 is formed higher from the plate 80. Accordingly, when the first movable portion 52 is displaced in a direction approaching the plate 80, the plurality of elastic members abut on the inner wall of the first movable portion 52 substantially simultaneously. Then, an elastic force is applied to the first movable portion 52 substantially evenly.
Further, the end portions of the plurality of elastic members on the second movable portion 62 side are also formed along the shape of the inner wall of the second movable portion 62 when the second movable portion 62 is displaced in the direction approaching the plate 80. Yes. Accordingly, when the second movable portion 62 is displaced in a direction approaching the plate 80, the plurality of elastic members abut on the inner wall of the second movable portion 62 almost simultaneously. Then, an elastic force is applied to the second movable portion 62 substantially evenly.
In the present embodiment, the elastic coefficient of the elastic member can be set smaller than in the first and second embodiments where the number of elastic members is single. Thereby, the pulsation reduction effect when the plurality of elastic members, the first movable part 52, and the second movable part 62 are operated in amplitude can be enhanced.
Further, in this embodiment, the contact displacement between the elastic member and the first movable portion and the second movable portion can be adjusted by appropriately setting the heights of the elastic members 410, 420, and 430. Thereby, the elastic coefficient with respect to the displacement of the first movable part and the second movable part can be arbitrarily set. Thus, the pulsation damper pulsation suppression characteristics can be set arbitrarily using factors other than the diaphragm material, plate thickness, movable part diameter, and gas pressure, and can be used in a wide range of use.

(Fourth embodiment)
A pulsation damper 50 according to a fourth embodiment of the present invention is shown in FIGS. Also in this embodiment, the central elastic member 410, the six annular elastic member groups 420, and the six outer annular elastic member groups 430 correspond to “elastic members” described in the claims.
In the present embodiment, the six annular elastic member groups 420 have a middle step 421 and an upper step 422 having a smaller diameter than the middle step 421.
The six outer annular elastic member groups 430 include a lower step portion 431, a middle step portion 432 having a smaller diameter than the lower step portion 431, and an upper step portion 433 having a smaller diameter than the middle step portion 432.
9 and 10, the middle step portion 421 and the upper step portion 422 of the annular elastic member group 420 described above have substantially the same configuration in the annular elastic member group 420, and the lower step portion 431 of the outer annular elastic member group 430. Since the middle step 432 and the upper step 433 have substantially the same configuration in the outer annular elastic member group 430, the reference numerals are omitted.
The elastic member is attached to the plate 80 by a method such as adhesion, pressure bonding, baking, or being inserted into a hole provided in the plate 80. The elastic member on the first diaphragm 51 side of the plate 80 and the elastic member on the second diaphragm 61 side are provided at substantially the same position.
In the present embodiment, the upper stage portions 422 and 433 or the middle stage portions 421 and 432 of the annular elastic member group 420 and the outer annular elastic member group 430 are formed to have a small diameter, so that a plurality of elastic members on the first movable portion 52 side are formed. It is possible to set the spring constant of the end portion and the end portion on the second movable portion 62 side small. Thereby, the pulsation reduction effect when the plurality of elastic members, the first movable part 52, and the second movable part 62 are operated in amplitude can be enhanced.
Further, by appropriately setting the heights of the central elastic member 410 and the annular elastic members 420 and 430, the pulsation damper pulsation suppression characteristics can be arbitrarily set as described above.

(Fifth embodiment)
11 and 12 show a pulsation damper 50 according to a fifth embodiment of the present invention. Also in this embodiment, the central elastic member 410, the six annular elastic member groups 420, and the six outer annular elastic member groups 430 correspond to “elastic members” described in the claims.
In the present embodiment, in the annular elastic member group 420 and the outer annular elastic member group 430, the end portion on the first diaphragm 51 side and the end portion on the second diaphragm 61 side are bent in the radially inward direction. Thereby, the spring constants of the annular elastic member group 420 and the outer annular elastic member group 430 can be set small. Therefore, the pulsation reduction effect of the pulsation damper 50 can be enhanced.
In the present embodiment, the annular elastic member group 420 and the outer annular elastic member group 430 are formed such that the end portion on the first movable portion 52 side and the end portion on the second movable portion 62 side are curved. Thereby, the surface pressure when the first movable part 52 or the second movable part 62 contacts the elastic member is reduced, and it is possible to suppress the stress concentration from occurring in the first and second diaphragms 51 and 61. it can.
Further, by appropriately setting the heights of the central elastic member 410, the annular elastic member 420, and the outer annular elastic member group 430, the pulsation damper pulsation suppression characteristics can be arbitrarily set as described above.

(Sixth embodiment)
A pulsation damper 50 according to a sixth embodiment of the present invention is shown in FIGS.
In the present embodiment, the elastic members are a central elastic member 410 provided on the central axis of the first diaphragm 51 and the second diaphragm 61, an annular elastic member 440 provided in an annular shape outside the diameter of the central elastic member 410, and an annular shape. The outer annular elastic member 450 is annularly provided on the outer diameter side of the elastic member 440. In the present embodiment, these elastic members correspond to “elastic members” recited in the claims.
The central elastic member 410, the annular elastic member 440, and the outer annular elastic member 450 are individually provided concentrically around the axes of the first diaphragm 51 and the second diaphragm 61. The elastic member is attached to the plate 80 by a method such as adhesion, pressure bonding, baking, or being inserted into a hole provided in the plate 80. The elastic member on the first diaphragm 51 side of the plate 80 and the elastic member on the second diaphragm 61 side are provided at substantially the same position.

Also in the present embodiment, the end portions of the plurality of elastic members on the first movable portion 52 side are along the shape of the inner wall of the first movable portion 52 when the first movable portion 52 is displaced in the direction approaching the plate 80. Is formed. Accordingly, when the first movable portion 52 is displaced in a direction approaching the plate 80, the plurality of elastic members abut on the inner wall of the first movable portion 52 substantially simultaneously. In addition, the elastic force can be applied to the first movable portion 52 substantially evenly.
Further, the end of the elastic member on the second movable portion 62 side is also formed along the shape of the inner wall of the second movable portion 62 when the second movable portion 62 is displaced in a direction approaching the plate 80. Accordingly, when the second movable portion 62 is displaced in a direction approaching the plate 80, the plurality of elastic members abut on the inner wall of the second movable portion 62 almost simultaneously. In addition, the elastic force can be applied to the second movable portion 62 substantially evenly.
Therefore, the surface pressure when the first and second movable parts 52 and 62 and the plurality of elastic members come into contact with each other is reduced, and the concentration of stress on the first and second diaphragms 51 and 61 is suppressed. Can do.
Further, by appropriately setting the heights of the central elastic member 410, the annular elastic member 440, and the outer annular elastic member 450, the pulsation damper pulsation suppression characteristics can be arbitrarily set as described above.

(Seventh embodiment)
A pulsation damper 50 according to a seventh embodiment of the present invention is shown in FIGS.
In the present embodiment, the elastic member includes a first elastic member 460 provided on the first diaphragm 51 side of the plate 80 and a second elastic member 470 provided on the second diaphragm 61 side of the plate 80. In the present embodiment, the first elastic member 460 and the second elastic member 470 correspond to “elastic members” recited in the claims.
The first elastic member 460 and the second elastic member 470 are formed in an annular shape by pressing a plate material made of, for example, stainless steel.
The first elastic member 460 includes a first support part 461, a first connection part 462, and a first clamping part 463.
The first support portion 461 is formed so that the end surface on the first movable portion 52 side is inclined toward the second movable portion 62 from the radially outer direction toward the radially inner direction. The first support portion 461 supports the outer edge of the first movable portion 52 when the first movable portion 52 and the second movable portion 62 are displaced in a direction in which they approach each other. A hole is provided in the radially inward direction of the first support portion 461.
The first connection portion 462 extends from the outer edge of the first support portion 461 to the first outer edge portion 53 side.
The first clamping portion 463 extends between the first outer edge portion 53 and the second outer edge portion 63 from the outer edge of the first connection portion 462.
The second elastic member 470 also has a second support part 471, a second connection part 472, and a second clamping part 473. The configurations of the second support portion 471, the second connection portion 472, and the second sandwiching portion 473 are substantially the same as the configurations of the first support portion 461, the first connection portion 462, and the first sandwiching portion 463. Omitted.
The 1st outer edge part 53, the 1st clamping part 463, the plate 80, the 2nd clamping part 473, and the 2nd outer edge part 63 overlap in this order, and are continuously welded from the plate | board thickness direction to the circumferential direction. Alternatively, the outer periphery of the first outer edge portion 53 and the first holding portion 463 and the plate 80 are continuously welded in the circumferential direction from the radial direction, and the outer periphery of the second outer edge portion 63 and the second holding portion 473 and the plate 80 are connected. It is welded continuously from the radial direction to the circumferential direction.

Next, the operation of the pulsation damper 50 of this embodiment will be described with reference to FIG.
Also in the present embodiment, in the pulsation damper 50, the gas filling pressure of the sealed space 60 is set corresponding to the fuel pressure of the fuel chamber 110 when the variable fuel pressure system is low.
FIG. 16A shows the state of the pulsation damper 50 when the high-pressure pump 10 is not operating, such as when the vehicle engine is stopped. At this time, since the fuel pressure in the fuel chamber 110 is substantially equal to the atmospheric pressure, the first movable portion 52 and the second movable portion 62 are displaced away from each other.

  FIG. 16B shows the operation of the pulsation damper 50 when the variable fuel pressure system is at a low pressure. The first movable part 52 and the second movable part 62 perform an amplitude operation based on a parallel state or a state slightly closer to each other than the parallel state. In FIG. 16B, the wave heights of the amplitude operations of the first movable part 52 and the second movable part 62 at the time of low pressure are indicated by H1 and H2, respectively.

FIG. 16C shows the operation of the pulsation damper 50 when the variable fuel pressure system is at a high pressure. The 1st movable part 52 and the 2nd movable part 62 are displaced to the direction which mutually approaches. The outer edge of the first movable part 52 is supported by the first support part 461. The outer edge of the second movable part 62 is supported by the second support part 471. The first support portion 461 and the second support portion 471 prevent contact between the central portion of the first movable portion 52 and the central portion of the second movable portion 62.
The first movable portion 52 and the second movable portion 62 can freely perform an amplitude operation without being supported by the first and second support portions 461 and 471 on the inner side of the outer edge of the first movable portion 52 and the second movable portion 62.
Further, the first support part 461 and the second support part 471 operate in amplitude together with the first movable part 52 and the second movable part 62. In FIG. 16C, the wave heights of the amplitude operations of the first movable portion 52 and the second movable portion 62 at the time of high pressure are indicated by H5 and H6, respectively. The spring constant k at this time is k = k1 + k2, where the spring constant of the first diaphragm 51 or the second diaphragm 61 is k1, and the spring constant of the first support portion 461 or the second support portion 471 is k2.

In the present embodiment, the first movable part 52 and the first support part 461, and the second movable part 62 and the second support part 471 come into contact with each other when the variable fuel pressure system is at a high pressure. Thereby, contact with the 1st movable part 52 and the 2nd movable part 62 can be avoided. Therefore, a decrease in fatigue strength of the first and second diaphragms 51 and 61 can be suppressed, and the service life of the pulsation damper 50 can be extended.
In the present embodiment, the first movable part 52 and the second movable part 62 freely perform amplitude operation on the inner side of the outer edge supported by the first and second support parts 461 and 471. For this reason, the pulsation damper 50 can obtain a high pulsation reduction effect.
Further, in the present embodiment, by setting the elastic coefficient of the elastic member to a small value, the first and second support portions 461 and 471, the first movable portion 52, and the second movable portion 62 are operated in amplitude. Thereby, the pulsation damper 50 can exhibit a high pulsation reduction effect at high pressure.
Further, by appropriately setting the shapes of the support members 461 and 471, the pulsation damper pulsation suppression characteristics can be arbitrarily set as described above.

(Eighth embodiment)
A pulsation damper 50 according to an eighth embodiment of the present invention is shown in FIG.
In this embodiment, the plate 80 is not provided. However, even in this configuration, the first clamping part 463 and the second clamping part 473 are sandwiched between the first outer edge part 53 and the second outer edge part 63 and welded together, so that the first, The second elastic members 460 and 470 are installed in the sealed space 60.
In the present embodiment, the axial distance of the pulsation damper 50 is reduced by reducing the distance between the first movable part 52 and the second movable part 62 by an amount corresponding to the plate thickness of the plate 80 as compared with the seventh embodiment. The physique can be reduced.

(Ninth embodiment)
A pulsation damper 50 according to a ninth embodiment of the present invention is shown in FIG.
In the present embodiment, the elastic member is made of, for example, rubber or resin. Also in this embodiment, the 1st elastic member 480 and the 2nd elastic member 490 are equivalent to the "elastic member" as described in a claim. The plate 80 is provided with a hole that communicates in the thickness direction. A first elastic member 480 and a second elastic member 490 are integrally formed through a hole in the plate 80.
The first elastic member 480 has a first support portion 481 and the second elastic member 490 has a second support portion 491.
The first support portion 481 is formed such that the end surface on the first diaphragm 51 side is inclined toward the second movable portion 62 side from the radially outer direction toward the radially inner direction. The first support portion 481 supports the outer edge of the first movable portion 52 when the first movable portion 52 and the second movable portion 62 are displaced in a direction in which they approach each other. A hole is provided in the radially inward direction of the first support portion 481.
The configuration of the second support portion 491 is substantially the same as the configuration of the first support portion 481.

Also in this embodiment, when the variable fuel pressure system is at a high pressure, when the first movable portion 52 and the second movable portion 62 are displaced in a direction approaching each other, the outer edge of the first movable portion 52 is supported by the first support portion 481. The outer edge of the second movable part 62 is supported by the second support part 491. Thereby, contact with the 1st movable part 52 and the 2nd movable part 62 is prevented.
The first movable part 52 and the second movable part 62 are freely oscillated on the inner diameter side of the outer edges supported by the first and second support parts 481 and 491. For this reason, a high pulsation reduction effect can be obtained.
Further, in the present embodiment, by setting the elastic coefficient of the elastic member to a small value, the first and second support portions 481 and 491 and the first and second movable portions 52 and 62 both perform an amplitude operation. Thereby, the pulsation damper 50 can exhibit a high pulsation reduction effect at high pressure.

(10th Embodiment)
A pulsation damper 50 according to a tenth embodiment of the present invention is shown in FIGS.
In the present embodiment, a first cover member 210 is provided on the opposite side of the first diaphragm 51 from the second diaphragm 61, and a second cover member 220 is provided on the opposite side of the second diaphragm 61 from the first diaphragm 51. . The first cover member 210 and the second cover member 220 are formed by, for example, pressing a metal having a predetermined rigidity such as stainless steel.
The first cover member 210 has a first annular portion 211 and a first restricting portion 212. The first annular portion 211 is formed in an annular shape and is provided on the opposite side of the first outer edge portion 53 from the second outer edge portion 63. The first restricting portion 212 includes a first arm portion 213 extending from the inner edge of the first annular portion 211 to the outside of the first curved surface portion 55 of the first diaphragm 51, and the opposite side of the first annular portion 211 of the first arm portion 213. And a first abutting portion 214 extending in the radially inward direction from the end of the first portion. A plurality of first restricting portions 212 are provided in the circumferential direction of the first annular portion 211.

Here, a plane including the contact surface between the first outer edge portion 53 and the plate 80 is defined as a virtual plane S. Further, the distance d between the virtual plane S and the center O of the outer end face of the first movable portion 52 when the air pressure between the sealed space 60 of the pulsation damper 50 and the outside of the pulsation damper 50 is equal.
The first cover member 210 is formed such that the distance between the end surface of the first contact portion 214 on the first diaphragm 51 side and the virtual plane S is the distance d1. Here, there is a relationship of d1> d. Thereby, the first restricting portion 212 can restrict the bulge of the first movable portion 52 to the opposite side of the second movable portion 62.

  The second cover member 220 also has a second annular portion 221 and a second restricting portion 222 having the same shape as the first cover member 210. The second cover member 220 is formed such that the distance between the end surface of the second contact portion 224 on the second diaphragm 61 side and the end surface of the plate 80 on the second diaphragm 61 side is the distance d1. Here, there is a relationship of d1> d. Thereby, the second restricting portion 222 can restrict the bulge of the second movable portion 62 to the opposite side of the first movable portion 52.

Next, the operation of the pulsation damper 50 of this embodiment will be described with reference to FIG.
In the present embodiment, in the pulsation damper 50, the gas filling pressure of the sealed space 60 is set corresponding to the fuel pressure of the fuel chamber 110 when the variable fuel pressure system is low.
FIG. 22A shows the operation of the pulsation damper 50 when the variable fuel pressure system is at a low pressure. The first movable part 52 and the second movable part 62 perform an amplitude operation with a state where they are close to each other as a reference position. In FIG. 22A, the wave heights of the amplitude operations of the first movable portion 52 and the second movable portion 62 at the time of low pressure are indicated by H1 and H2, respectively.

  FIG. 22B shows the operation of the pulsation damper 50 at the normal pressure of the variable fuel pressure system. The 1st movable part 52 and the 2nd movable part 62 are displaced to the direction which mutually approaches rather than the time of a low voltage | pressure. The first movable part 52 and the second movable part 62 operate in amplitude with the state as a reference position. In FIG. 22B, the wave heights of the amplitude operations of the first movable portion 52 and the second movable portion 62 at the normal pressure are indicated as H3 and H4, respectively.

FIG. 22C shows the operation of the pulsation damper 50 when the variable fuel pressure system is at a high pressure. The first movable part 52 and the second movable part 62 are displaced in a direction closer to each other than during normal pressure. The first movable part 52 and the second movable part 62 are in contact with the elastic member 40. The end surface of the elastic member 40 on the first diaphragm 51 side is elastically deformed into a curved surface along the shape of the inner wall of the first diaphragm 51. The end surface of the elastic member 40 on the second diaphragm 61 side is also elastically deformed into a curved surface along the shape of the inner wall of the second diaphragm 61.
Here, the elastic member 40 has such a small elastic coefficient as to be able to perform an amplitude operation together with the first diaphragm 51 and the second diaphragm 61. For this reason, the first diaphragm 51 and the second diaphragm 61 perform an amplitude operation together with the elastic member 40 on the basis of the state in contact with the elastic member 40. In FIG. 22C, the wave heights of the amplitude operations of the first movable portion 52 and the second movable portion 62 at the time of high pressure are indicated by H5 and H6, respectively. The spring constant k at this time is k = k1 + k2, where the spring constant of the first diaphragm 51 or the second diaphragm 61 is k1, and the spring constant of the elastic member 40 is k2.

Next, the stress generated in the pulsation damper 50 when the high-pressure pump 10 is operated will be described.
FIG. 23A shows the displacement of the first diaphragm 51 of the pulsation damper 50 of this embodiment, and FIG. 23B shows the stress generated in the first diaphragm 51 at that time.
The left side of time t0 in FIG. 23A is a state where the high-pressure pump 10 is not operating (hereinafter referred to as “non-operating state”) when the vehicle engine is stopped. From time t0 to time t1, the high-pressure pump 10 shifts from the non-operation state to the operation start state. After time t1, the high-pressure pump 10 is in an operating state.
Since the swelling of the first diaphragm 51 is restricted by the first restricting portion 212, the distance between the center O of the outer end surface of the first movable portion 52 and the virtual plane S is d1 in the non-operating state. When the operation state is shifted from the non-operation state to the operation start state, the fuel pressure in the fuel chamber 110 increases, so that the first movable portion 52 and the second movable portion 62 are displaced toward each other. The distance is reduced to d. When in the operating state, the first movable portion 52 and the second movable portion 62 repeat the amplitude operation due to the fuel pressure pulsation in the fuel chamber 110. For this reason, the distance between the center O of the first diaphragm 51 and the virtual plane S varies within a certain range.

In FIG. 23B, the stress generated in the first diaphragm 51 when the distance between the center O and the virtual plane S is larger than d is shown on the positive side (+) of the vertical axis, and the center O and the virtual plane S are The stress generated in the first diaphragm 51 when the distance is smaller than d is shown on the negative side (−) of the vertical axis.
Since the swelling of the first diaphragm 51 is restricted to d1 by the first restricting portion 212, the stress generated in the first diaphragm 51 in the non-operating state is σ1. When shifting from the non-operating state to the operation starting state, the stress generated in the first diaphragm 51 becomes zero. When the operating state is reached, the stress generated in the first diaphragm 51 varies within a certain range.
The displacement of the second diaphragm 61 and the stress generated in the second diaphragm 61 are generated in the same manner as the displacement and stress of the first diaphragm 51.

Here, the stress which arises in the pulsation damper of a comparative example is demonstrated.
The pulsation damper (not shown) of the comparative example does not include the first cover member and the second cover member. The air pressure in the sealed space of the pulsation damper of the comparative example is the same as that in the present embodiment. In the state where the pulsation damper is placed at atmospheric pressure, the first movable portion and the second movable portion are moved away from each other and swelled.

FIG. 24 (A) shows the displacement of the first diaphragm of the pulsation damper of the comparative example, and FIG. 24 (B) shows the stress generated in the first diaphragm at that time.
The left side of time t0 in FIG. 24 (A) is the non-operating state of the high-pressure pump. From time t0 to time t1, the high-pressure pump shifts from the non-operating state to the operating start state. After time t1, the high-pressure pump is in operation.
In the comparative example, the distance between the center O of the first diaphragm and the virtual plane S is expressed as d + Δd in the non-operating state. When the operation state is shifted from the non-operation state to the operation start state, the first movable portion and the second movable portion are displaced in a direction approaching each other, whereby the distance between the center O and the virtual plane S is reduced to d. When the operating state is reached, the first movable part and the second movable part perform amplitude operation. For this reason, the distance between the center O of the first diaphragm and the virtual plane S varies within a certain range.
As shown in FIG. 24B, the stress generated in the first diaphragm in the non-operating state shows a very large value on the positive side. When shifting from the non-operating state to the operation starting state, the stress generated in the first diaphragm becomes zero. When in the operating state, the stress generated in the first diaphragm varies within a certain range.
In the comparative example, the width of the displacement of the first diaphragm when the high-pressure pump shifts from the non-operating state to the starting state is large. At this time, the fluctuation range (stress amplitude) of the stress generated in the first diaphragm also becomes large.

  On the other hand, in the pulsation damper 50 according to the present embodiment, the first and second cover members 210 and 220 restrict the swelling of the first and second diaphragms 51 and 61. For this reason, the width of the displacement of the first diaphragm 51 when the high-pressure pump 10 shifts from the non-operating state to the starting state is smaller by Δd−d1 than the damper device of the comparative example. For this reason, the fluctuation range of the stress which arises in the 1st diaphragm 51 when the high pressure pump 10 transfers to the operation start state from a non-operation state can be reduced. As a result, the service life of the pulsation damper 50 can be extended, and reliability can be ensured even with a diaphragm having a thinner plate thickness, so that the pulsation suppressing effect can be improved.

  In the present embodiment, when the first movable portion 52 and the second movable portion 62 perform an amplitude operation in the operating state of the high-pressure pump 10, the first restricting portion 212 and the second restricting portion 222 are the first movable portion 52. And d2-d away from the second movable part 62. Thereby, abrasion with the 1st, 2nd control parts 212 and 222 and the 1st and 2nd movable parts 52 and 62 can be reduced.

(Eleventh embodiment)
A pulsation damper 50 according to an eleventh embodiment of the present invention is shown in FIG.
In the present embodiment, the pulsation damper 50 does not include the elastic member 40.
The plate 80 has a hole 83 communicating with the first sealed space 601 and the second sealed space 602 at the axial centers of the first diaphragm 51 and the second diaphragm 61.
Thereby, when the 1st movable part and the 2nd movable part approach, contact of the 1st movable part 52 and the 2nd movable part can be prevented by the thickness of plate 80. Further, the contact between the plate 80 and the first movable part 52 and the contact between the plate 80 and the second movable part 62 can be prevented.
Further, the gas sealing pressures of the first sealed space 601 and the second sealed space 602 are substantially the same. For this reason, the resonance frequency of the first diaphragm 51 and the resonance frequency of the second diaphragm 61 can be set to substantially the same value. Accordingly, the fuel pressure pulsation effect of the two diaphragms 51 and 61 is added, so that the pulsation damper 50 can exhibit a high pulsation reduction effect.

(Other embodiments)
In the above-described embodiment, the pulsation damper that reduces the pressure pulsation caused by the fuel discharged from the pressurizing chamber of the high-pressure pump to the supply passage side has been described. On the other hand, the pulsation damper of the present invention may reduce fuel pressure pulsation caused by fuel discharged from the pressurizing chamber of the high-pressure pump to the supply passage, and may be an injector installed in the fuel supply system. The fuel pressure pulsation due to the fuel injection may be reduced.
In the above-described embodiment, the gas filling pressure in the sealed space of the pulsation damper is set corresponding to the fuel pressure in the fuel chamber when the variable fuel pressure system is low. On the other hand, the pulsation damper according to the present invention has the durability of the pulsation damper with the gas filling pressure in the sealed space being an air pressure capable of suppressing the vapor generated in the fuel at the minimum fuel pressure required for the operation of the internal combustion engine. Alternatively, it can be appropriately set according to other required performance.
In another embodiment of the present invention, the first movable portion and the second movable portion are not limited to a flat plate shape, but may be formed so as to have a corrugated cross section by forming concentric folds. Good.
In the above-described embodiment, the damper device provided integrally with the high-pressure pump has been described. On the other hand, in another embodiment of the present invention, the damper device may be configured separately from the high-pressure pump, and may be applied to various devices that are required to attenuate fluid pulsation.
Thus, 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 10 ... High pressure pump 11 ... Pump housing (housing)
12 ... Lid member 13 ... Plunger 40 ... Elastic members 41, 460, 480 ... First elastic member (elastic member)
42,470,490 ... 2nd elastic member (elastic member)
47 ... Communication hole 50 ... Pulsation damper 51 ... First diaphragm 52 ... First movable part 53 ... First outer edge part 60 ... Sealed space 61 ... Second diaphragm 62 ... 2nd movable part 63 ... 2nd outer edge part 80 ... Plate (intermediate member)
110: Fuel chamber 111: Damper housing (housing)
121 ... Pressurizing chamber 210 ... 1st cover member 211 ... 1st annular part 212 ... 1st control part 220 ... 2nd cover member 221 ... 2nd annular part 222 ... -2nd control part 410 ... Central elastic member (elastic member)
420 ... Annular elastic member group (elastic member)
430 ... Outer annular elastic member group (elastic member)
440 ... Annular elastic member (elastic member)
450 ... Outer annular elastic member (elastic member)
461, 481 ... 1st support part 462 ... 1st connection part 463 ... 1st clamping part 471, 491 ... 2nd support part 472 ... 2nd connection part 473 ... 2nd Clamping part 601 ... 1st sealed space 602 ... 2nd sealed space

Claims (4)

A pulsation damper that is provided in a fuel chamber through which fuel of a fuel supply system flows and reduces pressure pulsation of fuel generated in the fuel supply system,
A first movable part having a first movable part elastically deformable by fuel pressure pulsation in the fuel chamber, and an annular first outer edge part provided at an outer edge of the first movable part;
A second movable part that forms a sealed space in which a gas of a predetermined pressure is sealed together with the first movable part and is elastically deformable by a fuel pressure pulsation in the fuel chamber, and an annular second provided at the outer edge of the second movable part. A second diaphragm having an outer edge;
A cylindrical elastic member provided in the sealed space and having a hole at a position corresponding to a central portion of the first movable portion and the second movable portion, and the first movable portion by a fuel pressure in the fuel chamber And the second movable part are displaced in a direction approaching each other, one or the other of the axial end portions of the elastic member is brought into contact with the outer edge of the first movable part or the second movable part. A pulsation damper comprising: an elastic member that restricts displacement of the first movable portion and the central portion of the second movable portion while restricting displacement of the first movable portion.   2. The pulsation damper according to claim 1, further comprising an intermediate member that is formed so as to extend in a radially outward direction of the elastic member and is sandwiched between the first outer edge portion and the second outer edge portion.   The elastic member has an end surface on the first movable portion side inclined from the radially outward direction to the radially inward direction toward the second movable portion side, and the end surface on the second movable portion side has a diameter from the radially outward direction. 3. The pulsation damper according to claim 1, wherein the pulsation damper is inclined toward the first movable portion in an inward direction. The first movable part of the first diaphragm has a disk-shaped first disk part, and a first curved surface part provided in a curved shape outside the first disk part,
The second movable part of the second diaphragm has a disk-shaped second disk part, and a second curved surface part provided in a curved shape outside the second disk part,
The first disc portion is a smooth curved surface or a planar shape,
The pulsation damper according to any one of claims 1 to 3, wherein the second disk portion has a smooth curved surface shape or a planar shape.

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