JP2015017584A - Pulsation damper and high-pressure pump including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulsation damper capable of suppressing resonance of a diaphragm and maintaining a pressure pulsation damping performance of fuel.SOLUTION: A pulsation damper 70 for damping pressure pulsation of fuel includes a first inscribed member 80 and a second inscribed member 90 that are combined in a radial direction of the pulsation damper 70 in a sealed space 73 formed by two diaphragms 71 and 72. The first inscribed member 80 has a first elastic part 81 making contact with an inner wall of the first diaphragm 71, a second elastic part 82 making contact with an inner wall of the second diaphragm 82, and a first support part 83 supporting an outer periphery of the first elastic part 81 and an outer periphery of the second elastic part 82. The second inscribed member 90 has a third elastic part 91 making contact with the inner wall of the first diaphragm 71, a fourth elastic part 92 making contact with the inner wall of the second diaphragm 72, and a second support part 93 supporting an outer periphery of the third elastic part 91 and an outer periphery of the fourth elastic part 92.

Description

  The present invention relates to a pulsation damper that reduces fuel pressure pulsation and a high-pressure pump including the pulsation damper.

Conventionally, a high-pressure pump that pressurizes fuel by reciprocating movement of a plunger is known.
The high-pressure pump includes a pulsation damper in a fuel chamber that communicates with a pump chamber in which fuel is pressurized. The pulsation damper is formed by joining the outer peripheries of two diaphragms, and has a sealed space in which a gas of a predetermined pressure is sealed. The pulsation damper reduces the pressure pulsation of the fuel in the fuel supply system including the fuel chamber and the fuel piping communicating therewith by displacing the two diaphragms so as to approach or separate from each other according to the pressure of the fuel.

  In the pulsation damper described in Patent Document 1, a resin film as a weight addition member is attached to only the inner wall of one diaphragm with an adhesive. As a result, the natural frequency of one diaphragm and the natural frequency of the other diaphragm are different. Therefore, the vibration transmitted from the internal combustion engine, the vibration transmitted from the electromagnetic drive part of the high-pressure pump, the high-frequency pulsation of the fuel in the fuel chamber, and the natural frequency of the diaphragm do not coincide with each other at the same time. Therefore, the pulsation damper can suppress resonance between these vibrations and the diaphragm.

Japanese Patent No. 4530053

However, in the pulsation damper described in Patent Document 1, since the resin film is attached to the diaphragm with an adhesive, if the resin film is peeled off due to deterioration of the adhesive over time, it is difficult to suppress the above-described resonance. There is.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a pulsation damper and a high-pressure pump capable of suppressing diaphragm resonance and maintaining fuel pressure pulsation damping performance.

According to a first aspect of the present invention, in the pulsation damper having a sealed space between two diaphragms, the first inscribed member and the second inscribed member combined in the radial direction of the pulsation damper are 2 in the sealed space. It is characterized by abutting against the inner wall of a single diaphragm.
The first inscribed member supports the first elastic part that contacts the first diaphragm, the second elastic part that contacts the second diaphragm, and the outer peripheral part of the first elastic part and the outer peripheral part of the second elastic part. It has a 1st support part.
The second inscribed member supports a third elastic portion that contacts the first diaphragm, a fourth elastic portion that contacts the second diaphragm, and an outer peripheral portion of the third elastic portion and an outer peripheral portion of the fourth elastic portion. It has a 2nd support part.

The first to fourth elastic parts abut against the two diaphragms, thereby suppressing the vibrations transmitted from the internal combustion engine, the vibrations transmitted from the electromagnetic drive part of the high-pressure pump, or the high-frequency pulsation of the fuel, and the diaphragm. Can do.
Moreover, since the outer peripheral part of the 1st-4th elastic part is supported by the 1st, 2nd support part, the location contact | abutted to the center part of a diaphragm is easy to bend. Moreover, since the 1st inscribed member and the 2nd inscribed member are combined in the radial direction of the pulsation damper, the location which contact | abuts to the center part of a diaphragm is easy to bend. Therefore, the pulsation damper can maintain the pressure pulsation damping performance without hindering deformation of the central portion of the diaphragm due to the pressure pulsation of the fuel.
Furthermore, since the first to fourth elastic portions are supported by the first support portion and the second support portion and are not attached to the diaphragm by an adhesive as in the technique described in Patent Document 1, the deterioration over time is caused. Can be prevented.

The second invention is a high-pressure pump provided with the pulsation damper of the first invention described above.
The high-pressure pump can suppress the resonance of the pulsation damper and reduce the pressure pulsation in the fuel chamber by the pulsation damper.

It is sectional drawing of the high pressure pump by 1st Embodiment of this invention. It is sectional drawing of the pulsation damper with which the high pressure pump of 1st Embodiment is provided. It is sectional drawing of the III-III line of FIG. It is an exploded view of the 1st inscribed member and the 2nd inscribed member with which the pulsation damper of a 1st embodiment is provided. It is a schematic diagram which shows the state which the pulsation damper of the comparative example resonated. It is sectional drawing of the pulsation damper of 2nd Embodiment. It is sectional drawing of the VII-VII line of FIG. It is an exploded view of the 1st inscribed member and the 2nd inscribed member with which the pulsation damper of a 2nd embodiment is provided. It is sectional drawing of the pulsation damper of 3rd Embodiment. It is sectional drawing of the XX line of FIG. It is an exploded view of the 1st inscribed member with which the pulsation damper of a 3rd embodiment is provided, the 2nd inscribed member, and the 3rd inscribed member. It is sectional drawing of the pulsation damper of 4th Embodiment. It is sectional drawing of the XIII-XIII line | wire of FIG. It is an exploded view of the 1st inscribed member and the 2nd inscribed member with which the pulsation damper of a 4th embodiment is provided. It is a disassembled perspective view of the 1st inscribed member and the 2nd inscribed member in the XV-XV line | wire of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A first embodiment of the present invention is shown in FIGS. The high-pressure pump 1 of the first embodiment pressurizes fuel pumped up from a fuel tank (not shown) by a low-pressure pump and discharges it to a delivery pipe (not shown). The fuel accumulated in the delivery pipe is injected into each cylinder of the internal combustion engine from an injector connected to the delivery pipe.

As shown in FIG. 1, the high-pressure pump 1 includes a cylinder 10, a plunger 11, a lower housing 12, an upper housing 13, a fuel supply unit 30, an electromagnetic drive unit 40, a fuel discharge unit 50, a cover 60, a pulsation damper 70, and the like. I have.
The cylinder 10, the lower housing 12, the upper housing 13, and the cover 60 of the present embodiment correspond to an example of a “pump body” described in the claims.

The cylinder 10 is formed in a cylindrical shape, and a plunger 11 is accommodated therein so as to be able to reciprocate. The lower housing 12 and the upper housing 13 are fixed to the outer wall of the cylinder 10 in the radially outward direction. The lower housing 12 can be attached to a mounting hole provided in an internal combustion engine (not shown).
A first spring 16 is provided between an oil seal holder 14 fixed to the lower housing 12 and a spring seat 15 fixed to the lower end portion of the plunger 11. The first spring 16 biases the plunger 11 to a camshaft of an internal combustion engine (not shown). Therefore, the plunger 11 can reciprocate in the axial direction according to the profile of the camshaft.

A pump chamber 17 is formed between the upper end of the plunger 11 and the inner wall of the cylinder 10. The cylinder 10 has a suction hole 18 that opens from the pump chamber 17 to one side in the radial direction, and a discharge hole 19 that opens to the other side.
The upper housing 13 is formed in a substantially rectangular parallelepiped, and a hole 20 provided in the center is oil-tightly fastened to the cylinder 10 and fixed to the upper side of the lower housing 12. The upper housing 13 has a fuel supply portion mounting hole 21 that communicates with the suction hole 18 of the cylinder 10 and a fuel discharge portion mounting hole 22 that communicates with the discharge hole 19 of the cylinder 10.

The fuel supply unit 30 includes an intake valve body 31, an intake valve seat member 32, an intake valve 33, a stopper member 34, and the like.
The intake valve body 31 is formed in a cylindrical shape and is fixed to the fuel supply portion mounting hole 21 of the upper housing 13.
A cylindrical intake valve seat member 32 is provided on the cylinder side of the intake valve body 31. The suction valve seat member 32 has a suction chamber 35 inside. The suction chamber 35 communicates with a fuel chamber 61 outside the upper housing through a hole 36 provided in the upper housing 13. The suction valve seat member 32 has a valve seat 37 at the opening on the pump chamber side of the suction chamber 35.
The suction valve 33 is provided on the pump chamber side of the valve seat 37, and can be seated or separated from the valve seat 37. The suction valve 33 contacts the stopper member 34 when the valve is opened.
A second spring 38 is provided between the stopper member 34 and the suction valve 33. The second spring 38 biases the suction valve 33 toward the valve seat.

The electromagnetic drive unit 40 includes a flange 41, a fixed core 42, a movable core 43, a rod 44, a coil 45, a third spring 46, and the like.
The flange 41 is fixed to the outer wall of the intake valve body 31. A movable core 43 is provided inside the suction valve body 31 so as to be able to reciprocate. A rod 44 is fixed at the center of the movable core 43. A guide member 47 fixed to the inside of the suction valve body 31 supports the rod 44 so as to be capable of reciprocating in the axial direction. The third spring 46 biases the movable core 43 and the rod 44 toward the pump chamber. The rod 44 can press the suction valve 33 toward the pump chamber.

A fixed core 42 is provided on the side of the movable core 43 opposite to the pump chamber, and a coil 45 is provided on the radially outer side of the fixed core 42. When the coil 45 is energized through the terminal 481 of the connector 48, magnetic flux flows through a magnetic circuit constituted by the movable core 43, the fixed core 42, the flange 41, the yoke 49, etc., and the movable core 43 and the rod 44 are connected to the third spring. It is magnetically attracted toward the fixed core against the urging force of 46.
On the other hand, when the energization to the coil 45 is stopped, the magnetic flux flowing through the magnetic circuit described above disappears, and the movable core 43 and the rod 44 are urged toward the pump chamber by the third spring 46.

The fuel discharge unit 50 includes a discharge valve body 51, a discharge valve seat member 52, a discharge valve 53, a fourth spring 54, and the like.
The discharge valve body 51 is formed in a cylindrical shape and is fixed to the fuel discharge portion mounting hole 22. A discharge valve seat member 52 is fixed inside the discharge valve body 51. The discharge valve seat member 52 has a flow path 55 and a discharge valve valve seat 57 at the opening of the flow path 55 on the fuel outlet 56 side. The discharge valve 53 can be seated and separated from the valve seat 57 for the discharge valve. The fourth spring 54 urges the discharge valve 53 toward the discharge valve valve seat 57.

The cover 60 is formed in a bottomed cylindrical shape, and the opening end thereof is fixed to the lower housing 12 in a liquid-tight manner. A fuel chamber 61 filled with fuel is formed inside the cover 60. The cover 60 is provided with a fuel inlet (not shown). Fuel pumped up from a fuel tank (not shown) is supplied to the fuel inlet. Therefore, fuel is supplied from the fuel inlet to the fuel chamber 61.
When the plunger 11 reciprocates, fuel is sucked from the fuel chamber 61 into the pump chamber 17, and when fuel is discharged from the pump chamber 17 into the fuel chamber 61, fuel pressure pulsation is generated in the fuel chamber 61. In this specification, the pressure pulsation of fuel is referred to as fuel pressure pulsation.

A pulsation damper 70 is provided inside the cover 60. The outer edge of the pulsation damper 70 is sandwiched between the upper fixing member 62 and the lower fixing member 63 and is installed between the upper housing 13 and the cover 60.
As shown in FIG. 2, the pulsation damper 70 includes a first diaphragm 71, a second diaphragm 72, a first inscribed member 80, and a second inscribed member 90.
The first diaphragm 71 and the second diaphragm 72 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 71 integrally includes a first outer edge portion 711, a first curved surface portion 712, and a first damper portion 713. In FIG. 2, the ranges of the first outer edge portion 711, the first curved surface portion 712, and the first damper portion 713 are indicated by A, B, and C, respectively.
The first outer edge portion 711 is formed in an annular shape. The first curved surface portion 712 extends from the first outer edge portion 711 to the side opposite to the second diaphragm 72 and bends inward in the radial direction.
The first damper portion 713 is provided on the radially inner side of the first curved surface portion 712. The first damper portion 713 has a larger radius of curvature than the first curved surface portion 712 and is formed in a substantially planar shape.

The second diaphragm 72 integrally includes a second outer edge portion 721, a second curved surface portion 722, and a second damper portion 723. Since the configuration of the second diaphragm 72 is substantially the same as the configuration of the first diaphragm 71, description thereof is omitted.
In addition, the 1st damper part 713 and the 2nd damper part 723 are not restricted to planar shape, For example, it is good also as a waveform.
The first diaphragm 71 and the second diaphragm 72 may have different shapes.

In the pulsation damper 70, the first outer edge 711 of the first diaphragm 71 and the second outer edge 721 of the second diaphragm 72 are joined, and a gas having a predetermined pressure is sealed in the inner sealed space 73. The pulsation damper 70 reduces the fuel pressure pulsation in the fuel chamber 61 by the two diaphragms 71 and 72 elastically deforming in the plate thickness direction centering on the central portion thereof according to the change in the fuel pressure in the fuel chamber 61. To do.
The spring constant of the pulsation damper 70 is set by appropriately setting the plate thickness, material, outer diameter, air pressure enclosed in the sealed space 73, etc. according to durability or other required performance. Is set. The frequency of the fuel pressure pulsation and the pulsation damping performance that can be reduced by the pulsation damper 70 are determined by the spring constant.

As shown in FIGS. 2 to 4, the first inscribed member 80 and the second inscribed member 90 are combined in the radial direction of the pulsation damper 70 so that the outer shape becomes a columnar shape and is provided in the sealed space 73. It is done. The first inscribed member 80 and the second inscribed member 90 are made of, for example, rubber, urethane, elastomer, or the like.
The first inscribed member 80 includes a first elastic part 81, a second elastic part 82, and a first support part 83.
The first elastic portion 81 is formed in a flat plate shape and abuts against the inner wall of the first diaphragm 71. The second elastic part 82 is formed in a flat plate shape and abuts against the inner wall of the second diaphragm 72.
The first support portion 83 supports the outer peripheral portion of the first elastic portion 81 and the outer peripheral portion of the second elastic portion 82.

The second inscribed member 90 includes a third elastic part 91, a fourth elastic part 92, and a second support part 93.
The third elastic portion 91 is formed in a flat plate shape and abuts on the inner wall of the first diaphragm 71. The fourth elastic portion 92 is formed in a flat plate shape and abuts against the inner wall of the second diaphragm 72.
The second support portion 93 supports the outer peripheral portion of the third elastic portion 91 and the outer peripheral portion of the fourth elastic portion 92.
Here, “the outer peripheral portion of the first elastic portion 81”, “the outer peripheral portion of the second elastic portion 82”, “the outer peripheral portion of the third elastic portion 91”, and “the outer peripheral portion of the fourth elastic portion 92” are When the first inscribed member 80 and the second inscribed member 90 are combined to form a columnar shape, a portion located on the outer periphery thereof is assumed.

As shown in FIGS. 3 and 4, the first elastic portion 81 and the second elastic portion 82 of the first inscribed member 80 include a first convex portion 84 extending toward the second inscribed member side and an anti-second inscribed portion. And a first recess 85 that is recessed toward the member side. Further, the third elastic portion 91 and the fourth elastic portion 92 of the second inscribed member 90 include a second convex portion 94 extending toward the first inscribed member side and a second concave portion 95 recessed toward the anti-first inscribed member side. And have. The first convex portion 84, the first concave portion 85, the second convex portion 94, and the second concave portion 95 are semicircular when viewed from the axial direction of the pulsation damper 70.
The first convex portion 84 of the first inscribed member 80 and the second concave portion 95 of the second inscribed member 90 have a corresponding shape, and when combined with each other, their end faces come into contact with each other. Moreover, the 1st recessed part 85 of the 1st inscribed member 80 and the 2nd convex part 94 of the 2nd inscribed member 90 are shapes corresponding, and when it mutually combines, those end surfaces will contact | abut. Thereby, the position shift of the 1st inscribed member 80 and the 2nd inscribed member 90 is prevented.

A virtual plane α that connects one end surface in the circumferential direction of the first inscribed member 80 and the other end surface is shown by a one-dot chain line in FIG. The distance that the first convex portion 84 extends from the virtual plane α to the second inscribed member side is L1, and the distance that the first concave portion 85 is recessed from the virtual plane α to the anti-second inscribed member side is L2.
In FIG. 3, the virtual plane α also connects one end surface and the other end surface in the circumferential direction for the second inscribed member 90. The distance that the second convex portion 94 extends from the virtual plane α toward the first inscribed member side is L2, and the distance that the first concave portion 85 is recessed from the virtual plane α toward the anti-first inscribed member side is L1.
The larger L1 and L2 are, the lower the rigidity of the first convex portion 84 of the first inscribed member 80 and the second convex portion 94 of the second inscribed member 90 is. Therefore, it is possible to adjust the ease of bending of the first to fourth elastic portions 81, 82, 91, 92 by setting L1 and L2.

The first support portion 83 and the second support portion 93 have passages 86 and 96 that communicate with each other in the radial direction. In the sealed space 73, the passages 86 and 96 are a space radially inward of the first support portion 83 and the second support portion 93, and a space radially outward of the first support portion 83 and the second support portion 93. Communicate with.
The larger the opening area of the passages 86 and 96, the lower the rigidity of the first support part 83 and the second support part 93. Therefore, by setting the opening area of the passages 86 and 96, the first support portion 83 and the second support portion 93 exert a force to press the first to fourth elastic portions 81, 82, 91 and 92 against the diaphragms 71 and 72. It is possible to adjust.
Further, since the first support portion 83 and the second support portion 93 have the passages 86 and 96, the deformation of the central portion of the two diaphragms 71 and 72 in the plate pressure direction is caused by the first support portion 83 and the second support portion 93. It is not hindered by the atmospheric pressure in the space radially inward of the portion 93. Therefore, the pulsation damper 70 can maintain the pressure pulsation damping performance.

The first elastic part 81 and the third elastic part 91 are in contact with substantially the entire area of the first damper part 713 from the vicinity of the connection portion between the first curved surface part 712 and the first damper part 713. In addition, the connection location is the boundary between B and C shown in FIG.
The first elastic portion 81 and the third elastic portion 91 may be in contact with most regions of the first damper portion 713 from the vicinity of the connection portion between the first curved surface portion 712 and the first damper portion 713. Here, “in the vicinity of the connection location” is a region that is larger or smaller than the diameter of the connection location, and refers to a range in which a decrease in resonance suppression performance by the elastic portions 81 and 91 is allowed.

When the outer diameters of the first elastic part 81 and the third elastic part 91 are smaller than the diameter of the connection location, even when the positions of the first elastic part 81 and the third elastic part 91 are shifted due to tolerance during assembly, It is possible to prevent the first curved portion 712 of the first diaphragm 71 from pressing the outer peripheral portion of the first elastic portion 81 or the third elastic portion 91 and causing unintended deformation there.
However, if the outer diameters of the first elastic part 81 and the third elastic part 91 are smaller than the diameter of the connection portion, the resonance suppression performance is reduced. Therefore, it is preferable that the first elastic part 81 and the third elastic part 91 abut on a range of 80% or more of the area of the first damper part 713.

On the other hand, when the shape of the outer peripheral portion of the first diaphragm side end surface of the first elastic portion 81 and the third elastic portion 91 is made to correspond to the shape of the first curved surface portion 712 of the first diaphragm 71, the first elastic portion 81 and the first elastic portion 81 The outer diameter of the 3 elastic part 91 can be made larger than the diameter of the connection part.
In the first diaphragm 71, the radius of curvature of the first curved surface portion 712 and the radius of curvature of the first damper portion 713 are different. Therefore, after the first elastic member 81 and the third elastic member 91 are in contact with the vicinity of the connection portion, the first internal member 80 and the second internal member 90 are attached to the sealed space 73, and then the first internal portion It is possible to prevent the contact member 80 and the second inscribed member 90 from moving in the radial direction in the sealed space.

The second elastic portion 82 and the fourth elastic portion 92 abut on the substantially entire area of the second damper portion 723 from the vicinity of the connection portion between the second damper portion 723 and the second curved surface portion 722.
Since the configurations of the second elastic portion 82 and the fourth elastic portion 92 are substantially the same as the configurations of the first elastic portion 81 and the third elastic portion 91 described above, the second elastic portion 82 and the fourth elastic portion 92 are provided. Description of is omitted.

The first support portion 83 presses the first elastic portion 81 against the first damper portion 713 and presses the second elastic portion 82 against the second damper portion 723. The second support portion 93 presses the third elastic portion 91 against the first damper portion 713 and presses the fourth elastic portion 92 against the second damper portion 723. Therefore, the first elastic part 81 and the third elastic part 91 can suppress the resonance of the first diaphragm 71, and the second elastic part 82 and the fourth elastic part 92 can suppress the resonance of the second diaphragm 72.
In addition, the first to fourth elastic portions 81, 82, 91, 92 are not supported by the first support portion 83 or the second support portion 93 at the center position of the pulsation damper 70. Therefore, the central portion of the pulsation damper 70 can be easily deformed in the plate thickness direction.

Next, the operation of the high-pressure pump 1 will be described.
(1) Suction stroke When the plunger 11 descends from the top dead center toward the bottom dead center due to the rotation of the camshaft, the volume of the pump chamber 17 increases and the fuel is depressurized. The discharge valve 53 is seated on the discharge valve valve seat 57 and closes the flow path 55.
On the other hand, the suction valve 33 moves to the pump chamber side against the urging force of the second spring 38 due to the pressure difference between the pump chamber 17 and the suction chamber 35 and is opened.
By opening the suction valve 33, the fuel in the fuel chamber 61 flows through the suction chamber 35 and flows into the pump chamber 17.

When the fuel pressure in the fuel chamber 61 decreases during the intake stroke, the pulsation damper 70 is displaced in a direction in which the two diaphragms 71 and 72 are separated from each other. That is, the two diaphragms 71 and 72 swell in the thickness direction with the central portion of the damper portions 713 and 723 as the center. As a result, the volume of the fuel chamber 61 is reduced, and a decrease in the fuel pressure in the fuel chamber 61 is suppressed.
At this time, the first to fourth elastic portions 81, 82, 91, 92 are deformed following the displacement of the diaphragms 71, 72 while being in contact with the inner walls of the two diaphragms 71, 72.

(2) Metering stroke When the plunger 11 rises from the bottom dead center toward the top dead center due to the rotation of the camshaft, the volume of the pump chamber 17 decreases. At this time, since energization to the coil 45 is stopped until a predetermined time, the rod 44 presses the suction valve 33 toward the pump chamber by the urging force of the third spring 46. Therefore, the intake valve 33 maintains the valve open state.
By opening the intake valve 33, the pump chamber 17 and the fuel chamber 61 are maintained in communication with each other. For this reason, the low-pressure fuel once sucked into the pump chamber 17 is returned to the fuel chamber 61, and the fuel pressure in the fuel chamber 61 increases. On the other hand, the pressure in the pump chamber 17 does not increase.

In the metering stroke, when the fuel pressure in the fuel chamber 61 increases, the pulsation damper 70 is displaced in a direction in which the two diaphragms 71 and 72 approach each other. That is, the two diaphragms 71 and 72 are recessed in the plate thickness direction with the central portion of the damper portions 713 and 723 as the center. As a result, the volume of the fuel chamber 61 is increased, and an increase in fuel pressure in the fuel chamber 61 is suppressed.
At this time, the first to fourth elastic portions 81, 82, 91, 92 are deformed following the displacement of the diaphragms 71, 72 while being in contact with the inner walls of the two diaphragms 71, 72.

When the coil 11 is energized at a predetermined time while the plunger 11 is rising from the bottom dead center toward the top dead center, a magnetic attraction is generated between the fixed core 42 and the movable core 43 by the magnetic field generated in the coil 45. Force is generated. When this magnetic attractive force becomes larger than the difference between the elastic force of the second spring 38 and the elastic force of the third spring 46, the movable core 43 moves to the fixed core side. Thereby, the pressing force of the rod 44 against the suction valve 33 is released.
Then, the suction valve 33 moves in the valve closing direction following the operation of the rod 44 by the elastic force of the second spring 38 and the dynamic pressure of the low pressure fuel discharged from the pump chamber 17 to the suction chamber side. Sit on the seat. Thereby, the pump chamber 17 and the suction chamber 35 are shut off.

(3) Discharge stroke After the intake valve 33 is closed, the fuel pressure in the pump chamber 17 increases as the plunger 11 rises. When the force of the fuel pressure in the pump chamber 17 acting on the discharge valve 53 becomes larger than the force of the fuel pressure on the fuel outlet 56 side acting on the discharge valve 53 and the biasing force of the fourth spring 54, the discharge valve 53 opens. To do. Thereby, the high-pressure fuel pressurized in the pump chamber 17 is discharged from the fuel outlet 56.
Note that energization of the coil 45 is stopped in the middle of the discharge stroke. Since the force that the fuel pressure in the pump chamber 17 acts on the suction valve 33 is larger than the urging force of the third spring 46, the suction valve 33 maintains the closed state.

The high-pressure pump 1 repeats an intake stroke, a metering stroke, and a discharge stroke, pressurizes and discharges an amount of fuel necessary for the internal combustion engine.
The pulsation damper 70 suppresses the fuel pressure pulsation because the two diaphragms 71 and 72 are elastically deformed around the central portions of the damper portions 713 and 723 along with the fuel pressure pulsation of the fuel chamber 61. Further, the first to fourth elastic portions 81, 82, 91, 92 abut against the inner walls of the two diaphragms 71, 72 and suppress the resonance of the diaphragms 71, 72.

Here, a pulsation damper 700 of a comparative example will be described with reference to FIG.
The pulsation damper 700 of the comparative example does not include the first inscribed member and the second inscribed member.
FIG. 5 schematically shows an example of a state in which the pulsation damper 700 of the comparative example resonates with the surrounding vibration. The ambient vibration includes vibration transmitted from the internal combustion engine, vibration transmitted from the electromagnetic drive unit 40 of the high-pressure pump 1, or high-frequency pulsation of fuel in the fuel chamber 61. When these vibrations coincide with the natural frequencies of the diaphragms 710 and 720, as shown in FIG. 5A, the diaphragms 710 and 720 vibrate finely due to resonance. As shown in FIG. 5B, this resonance is not limited to that indicated by the concentric circles of the broken line, but may occur simultaneously at a plurality of locations of the diaphragms 710 and 720, and the vibrations may overlap.
When resonance occurs in the pulsation damper 700, the vibration is transmitted to the cover 60 of the high-pressure pump 1, and there is a concern that noise may be generated. Further, there is a risk that noise may be generated in the passenger compartment or the like through a fuel pipe or the like connected to the fuel inlet.

On the other hand, the high-pressure pump 1 of the first embodiment has the following operational effects.
(1) In the first embodiment, the first inscribed member 80 and the second inscribed member 90 combined in the radial direction of the pulsation damper 70 are in contact with the inner walls of the two diaphragms 71 and 72 in the sealed space. Touch. In the first inscribed member 80, the first support portion 83 supports the outer peripheral portion of the first elastic portion 81 that contacts the first diaphragm 71 and the outer peripheral portion of the second elastic portion 82 that contacts the second diaphragm 72. . In the second inscribed member 90, the second support portion 93 supports the outer peripheral portion of the third elastic portion 91 that contacts the first diaphragm 71 and the outer peripheral portion of the fourth elastic portion 92 that contacts the second diaphragm 72. .
When the first to fourth elastic portions 81, 82, 91, 92 are in contact with the two diaphragms 71, 72, vibrations transmitted from the internal combustion engine, vibrations transmitted from the electromagnetic drive unit 40 of the high-pressure pump 1, or high frequency of the fuel Resonance between the pulsation and the like and the diaphragms 71 and 72 can be suppressed. Therefore, generation of noise from the pulsation damper 70 and generation of noise from the cover 60 of the high-pressure pump 1 can be suppressed.
The first to fourth elastic portions 81, 82, 91, 92 are supported by the first and second support portions 83, 93 at the outer peripheral portions thereof, so that they are in contact with the central portions of the diaphragms 71, 72. Is easy to bend. In addition, since the first inscribed member 80 and the second inscribed member 90 are combined in the radial direction of the pulsation damper 70, the portion that comes into contact with the central portions of the diaphragms 71 and 72 is easily bent. Therefore, the pulsation damper 70 can maintain the pressure pulsation damping performance without hindering deformation of the central portions of the diaphragms 71 and 72.
Furthermore, since the first to fourth elastic portions 81, 82, 91, 92 are supported by the first and second support portions 83, 93 and are not attached to the diaphragms 71, 72 by the adhesive, Deterioration can be prevented.

(2) In the first embodiment, the first convex portion 84 of the first inscribed member 80 and the second concave portion 95 of the second inscribed member 90 are combined, and the first inscribed member 80 has the first. The concave portion 85 and the second convex portion 94 of the second inscribed member 90 are combined.
Thereby, the position shift of the 1st inscribed member 80 and the 2nd inscribed member 90 can be prevented.
Further, by setting a distance L1 that the first convex portion 84 extends from the virtual plane α to the second inscribed member side and a distance L2 that the second convex portion 94 extends from the virtual plane α to the first inscribed member side, It is possible to adjust the ease of bending of the central part of the first to fourth elastic parts 81, 82, 91, 92.

(3) In the first embodiment, the first elastic portion 81 and the third elastic portion 91 contact the substantially entire area of the first damper portion 713 from the vicinity of the connection portion between the first damper portion 713 and the first curved surface portion 712. Touch. The second elastic portion 82 and the fourth elastic portion 92 abut on the substantially entire area of the second damper portion 723 from the vicinity of the connection portion between the second damper portion 723 and the second curved surface portion 722.
As a result, the first to fourth elastic portions 81, 82, 91, 92 are in contact with most of the movable regions of the two diaphragms 71, 72, thereby reliably suppressing the resonance of the diaphragms 71, 72. Can do.

(4) In the first embodiment, the first support portion 83 and the second support portion 93 have passages 86 and 96 that communicate in the radial direction.
The force of pressing the first to fourth elastic portions 81, 82, 91, 92 against the diaphragms 71, 72 by adjusting the rigidity of the first support portion 83 and the second support portion 93 by setting the opening areas of the passages 86, 96. Can be adjusted.
The deformation in the plate pressure direction at the center of the two diaphragms 71 and 72 is not hindered by the atmospheric pressure in the space radially inward of the first support portion 83 and the second support portion 93, and the pulsation damper. 70 can maintain the pressure pulsation damping performance.

(5) In the first embodiment, the first inscribed member 80 and the second inscribed member 90 have the same shape.
Thereby, the kind of components can be decreased and manufacturing cost can be reduced.

(Second Embodiment)
A second embodiment of the present invention is shown in FIGS. Hereinafter, in a plurality of embodiments, the same numerals are given to the composition substantially the same as composition of a 1st embodiment mentioned above, and explanation is omitted.
In the second embodiment, the first inscribed member 80 has one first concave portion 85 in the first elastic portion 81 and one first convex portion 84 in the second elastic portion 82. Further, the second inscribed member 90 has one second convex portion 94 in the third elastic portion 91 and one second concave portion 95 in the fourth elastic portion 92. The first concave portion 85 and the second convex portion 94 have a corresponding shape, and the first convex portion 84 and the second concave portion 95 have a corresponding shape.
The first convex portion 84 and the second convex portion 94 are semicircular when viewed from the axial direction of the pulsation damper 70, and the center of the circle substantially coincides with the center of the pulsation damper 70.
The distance that the first convex portion 84 extends from the virtual plane α to the second inscribed member side is L1, and the distance that the second convex portion 94 extends from the virtual plane α to the first inscribed member side is L2. The larger L1 and L2 are, the lower the rigidity of the first convex portion 84 of the first inscribed member 80 and the second convex portion 94 of the second inscribed member 90 is. Therefore, the ease of bending of the first to fourth elastic portions 81, 82, 91, 92 can be adjusted by setting L1 and L2.

In addition, the first inscribed member 80 has a third convex portion 87 projecting toward the second inscribed member side and a third concave portion 88 recessed toward the second inscribed member side in the first support portion 83. The second inscribed member 90 has a fourth convex portion 97 projecting toward the first inscribed member side and a fourth concave portion 98 recessed toward the anti-first inscribed member side in the second support portion 93. The 3rd convex part 87 and the 4th recessed part 98 are shapes corresponding, and are mutually combined. The third concave portion 88 and the fourth convex portion 97 have corresponding shapes and are combined with each other. Thereby, the position shift of the axial direction of the 1st inscribed member 80 and the 2nd inscribed member 90 can be prevented.
Further, the first inscribed member 80 and the second inscribed member 90 can be assembled together so that the pulsation damper 70 can be easily assembled in the sealed space.
The second embodiment can achieve the same effects as the first embodiment.

(Third embodiment)
A third embodiment of the present invention is shown in FIGS. In the third embodiment, the pulsation damper 70 includes a first inscribed member 110, a second inscribed member 120, and a third inscribed member 130.
The first to third inscribed members 110, 120, and 130 are fan-shaped when viewed from the axial direction of the pulsation damper 70. The first to third inscribed members 110, 120, and 130 are provided in the sealed space 73, with the end faces in the circumferential direction coming into contact with each other with the center of the pulsation damper 70 as a boundary.

The first inscribed member 110 includes a first elastic part 111, a second elastic part 112, and a first support part 113. The second inscribed member 120 includes a third elastic part 121, a fourth elastic part 122, and a second support part 123. The third inscribed member 130 includes a fifth elastic part 131, a sixth elastic part 132, and a third support part 133.
The first elastic part 111, the third elastic part 121, and the fifth elastic part 131 are in contact with the inner wall of the first diaphragm 71. The second elastic part 112, the fourth elastic part 122, and the sixth elastic part 132 are in contact with the inner wall of the second diaphragm 72.
The first to third inscribed members 110, 120, and 130 have passages 114, 124, and 134 that communicate with each other in the radial direction.

  In the third embodiment, the first to third inscribed members 110, 120, and 130 are combined with the center of the pulsation damper 70 as a boundary. Therefore, as shown in FIG. 10, in the first inscribed member 110, the pulsation damper in the first elastic portion 111 is taken from a virtual plane β that connects one end surface in the circumferential direction of the first support portion 113 and the other end surface. The vertical distance L3 to the position corresponding to the center of 70 becomes longer. The same applies to the second inscribed member 120 and the third inscribed member 130. Therefore, the first to third inscribed members 110, 120, and 130 are likely to bend at locations where they contact the central portions of the diaphragms 71 and 72. Therefore, the pulsation damper 70 can maintain its pulsation damping performance without the first to third inscribed members 110, 120, 130 hindering the operation of the diaphragms 71, 72.

(Fourth embodiment)
A fourth embodiment of the present invention is shown in FIGS. In the fourth embodiment, the first inscribed member 80 does not have the first convex portion 84 and the first concave portion 85. The second inscribed member 90 also does not have the second convex portion 94 and the second concave portion 95.
Instead, the first inscribed member 80 includes a first rib 89 that extends radially inward from the first support portion 83 and supports the first elastic portion 81 and the second elastic portion 82. The second inscribed member 90 includes a second rib 99 that extends radially inward from the second support portion 93 and supports the third elastic portion 91 and the fourth elastic portion 92.

  In the fourth embodiment, the rigidity of the first elastic part 81 and the second elastic part 82 can be adjusted by setting the length, width, or number of the first ribs 89. Further, the rigidity of the third elastic portion 91 and the fourth elastic portion 92 can be adjusted by setting the length, width, or number of the second ribs 99. Therefore, the pulsation damper 70 can both maintain its pulsation damping performance and suppress resonance.

(Other embodiments)
In the embodiment described above, the damper portion of the pulsation damper is planar. On the other hand, in other embodiments, the damper portion of the pulsation damper may have a wave shape or the like.
In the embodiment described above, the first inscribed member and the second inscribed member are made of the same shape and the same material. On the other hand, in other embodiments, the first inscribed member and the second inscribed member may be made of different shapes and different materials.
In the first, third, and fourth embodiments described above, all the inscribed members have passages. On the other hand, in another embodiment, one inscribed member may have a passage, or the passage may be eliminated.
In the first, second, and fourth embodiments described above, two inscribed members are combined, and in the fourth embodiment, three inscribed members are combined. On the other hand, in another embodiment, four or more inscribed members may be combined in the radial direction and / or the circumferential direction of the pulsation damper.
The present invention is not limited to the above-described plurality of embodiments. In addition to combining the above-described plurality of embodiments, the present invention can be implemented in various forms without departing from the spirit of the invention.

70 ... pulsation dampers 80, 110 ... first inscribed members 81, 111 ... first elastic parts 82, 112 ... second elastic parts 83, 113 ... first support parts 90, 120 ... second inscribed members 91, 121 ... third elastic parts 92, 122 ... fourth elastic parts 93, 123 ... second support parts

Claims (8)

A pulsation damper (70) for reducing pressure pulsation of fuel flowing through the fuel chamber (61),
A first diaphragm (71) elastically deformable by pressure pulsation of fuel in the fuel chamber;
A second diaphragm (72) that forms a sealed space (73) filled with a gas of a predetermined pressure together with the first diaphragm and is elastically deformable by pressure pulsation of fuel in the fuel chamber;
A first elastic part (81, 111) contacting the inner wall of the first diaphragm; a second elastic part (82, 112) contacting the inner wall of the second diaphragm; and an outer peripheral part of the first elastic part and the A first support member (80, 110) that has a first support portion (83, 113) that supports the outer peripheral portion of the second elastic portion, and is provided in the sealed space;
A third elastic portion (91, 121) that contacts the inner wall of the first diaphragm, a fourth elastic portion (92, 122) that contacts the inner wall of the second diaphragm, and an outer peripheral portion of the third elastic portion; A second support portion (93, 123) that supports the outer peripheral portion of the fourth elastic portion, and is combined with the first inscribed member in the radial direction of the pulsation damper, and is provided in the sealed space. A pulsation damper comprising an inscribed member (90, 120). The first inscribed member has a first convex portion (84) extending toward the second inscribed member side, and a first concave portion (85) recessed toward the anti-second inscribed member side,
The second inscribed member extends to the first inscribed member side and is combined with the first recessed portion, and the second protruded portion (94) is recessed toward the anti-first inscribed member side and combined with the first raised portion. The pulsation damper according to claim 1, further comprising a second recess (95). The first diaphragm includes an annular first outer edge portion (711) joined to an outer edge of the second diaphragm, a first curved surface portion (712) extending from the first outer edge portion toward the second diaphragm side, and a first thereof. A first damper portion (713) provided radially inside the curved surface portion;
The second diaphragm includes an annular second outer edge portion (721) joined to an outer edge of the first diaphragm, a second curved surface portion (722) extending from the second outer edge portion to the side opposite to the first diaphragm, and a second thereof. A second damper portion (723) provided radially inward of the curved surface portion;
The first elastic part and the third elastic part are in contact with substantially the entire area of the first damper part from the vicinity of the connection portion between the first damper part and the first curved surface part,
The said 2nd elastic part and the said 4th elastic part are contact | abutted to the substantially whole area of the said 2nd damper part from the vicinity of the connection location of the said 2nd damper part and the said 2nd curved surface part. Or the pulsation damper as described in 2.   4. At least one of the first support part and the second support part has a passage (86, 96, 114, 124) that communicates in the radial direction. The listed pulsation damper.   The pulsation damper according to any one of claims 1 to 4, wherein the first inscribed member and the second inscribed member have the same shape. A fifth elastic portion (131) that contacts the inner wall of the first diaphragm, a sixth elastic portion (132) that contacts the inner wall of the second diaphragm, and an outer peripheral portion and the sixth elastic portion of the fifth elastic portion A third support portion (133) that supports the outer peripheral portion of the pulsation damper and abuts against the first inscribed member (110) and the second inscribed member (120) in the circumferential direction of the pulsation damper, and the sealed space A third inscribed member (130) provided in the
2. The pulsation damper according to claim 1, wherein the first inscribed member, the second inscribed member, and the third inscribed member are combined with a center of the pulsation damper as a boundary. The first inscribed member has a first rib (89) extending radially inward from the first support portion and supporting the first elastic portion and the second elastic portion,
The second inscribed member has a second rib (99) extending radially inward from the second support portion and supporting the third elastic portion and the fourth elastic portion. The pulsation damper as described in any one of 1 to 6. A plunger (11);
A pump chamber (17) in which fuel is pressurized by the reciprocating movement of the plunger, and a pump body (10, 12, 13, 60) having a fuel chamber communicating with the pump chamber;
A high pressure pump (1) comprising: the pulsation damper according to claim 1, wherein pressure pulsation of fuel discharged from the pump chamber to the fuel chamber can be reduced.

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