JP2006291838A - High pressure fuel pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize the operation of an overflow control valve by preventing the effect of operating pressure of fuel when overflowing, on the control valve for the overflowing fuel. <P>SOLUTION: An intake valve is isolated from a fluid passage to prevent the effect of the fluid force (dynamic pressure) of fuel overflowing through the fluid passage on the back face of the intake valve arranged in the fluid passage between a suction port and a pressure chamber. This reduces the effect of the fluid force on the intake valve with the fuel flowing back in a return process (an overflow process). A load on an actuator is reduced, leading to a higher rotating speed and a greater flow amount. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high-pressure fuel pump that supplies high-pressure fuel to, for example, a fuel injection valve of an automobile engine. In particular, the discharge amount is controlled by overflowing part of the fuel sucked into a pressurizing chamber through the valve. The present invention relates to a high-pressure fuel pump.

  In the high-pressure fuel pump described in International Publication No. WO 00/47888, the actuator is driven for each discharge process, and the opening / closing timing of the intake valve is operated to adjust the amount of fuel overflowing from the intake valve to the low-pressure passage. The discharge flow rate is controlled.

  In another method, an opening communicating with the pressurizing chamber is provided separately from the suction port, and an opening / closing valve for opening / closing the opening is provided on the pressurizing chamber side. Some control the discharge amount by overflowing part of the sucked fuel. In this case, the on-off valve is called an overflow valve.

International Publication No. WO00 / 47888 Pamphlet

  In the above-described conventional high-pressure fuel pump, when fuel overflows from the pressurizing chamber to the low-pressure passage or other fluid passage through the suction port or the overflow port, the fuel is not moved behind the suction valve or the overflow valve. Since the pressure acts, the actuator needs to produce an operating force larger than the dynamic pressure of the fuel acting on the back surface of the intake valve or the overflow valve, or needs to be opened and closed at a control timing in consideration of the dynamic pressure of the fuel.

  For this reason, there is a problem that the actuator must be large. In addition, since the dynamic pressure changes depending on the operating state of the engine, there is also a problem that it is difficult to carry out the control considering the dynamic pressure in the control of the opening / closing timing.

  An object of the present invention is to prevent the operating pressure of the fuel during overflow from acting on the control valve of the overflow fuel, thereby stabilizing the operation of the overflow control valve.

  The overflow control valve referred to in the present invention includes an intake valve or a dedicated overflow valve for controlling overflow fuel provided separately from the intake valve.

  In order to achieve the above object, according to the present invention, between the pressurizing chamber and the intake valve of the variable flow type high-pressure fuel pump, a shielding portion that prevents the fuel escaping from the pressurizing chamber from directly hitting the intake valve, that is, the movement of fluid. An isolation member for isolating the back surface of the valve on which the pressure acts from the fluid flow path is provided. By doing so, it is possible to reduce the fluid force due to the dynamic pressure at the time of overflow of the fuel acting on the suction valve and the overflow valve.

  Thus, according to the present invention, the back surface of the suction valve is protected from the dynamic pressure of the fluid flowing from the pressurizing chamber to the suction port, and the static pressure acts appropriately. It was possible to prevent the opening and closing operation from becoming unstable under the influence of

  An embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing the entire high-pressure fuel supply pump in which the present invention is implemented. FIG. 2 is an overall system diagram of a fuel supply system for an internal combustion engine, and shows a high-pressure fuel supply system used in a direct injection internal combustion engine.

  A suction joint 10 that forms a fuel suction port and a discharge joint 11 that forms a fuel discharge port are fixed to the pump body 1 by screwing, and fuel is pressurized in the middle of a fuel passage from the suction joint 10 to the discharge joint 11. A pressurizing chamber 12 is formed.

  A suction valve 5 is provided at the inlet of the pressurizing chamber 12, and a discharge valve 6 is provided at the discharge joint 11. The suction valve 5 and the discharge valve 6 are urged by springs 5a and 6a, respectively, to close the suction port and the discharge port of the pressurizing chamber 12, thereby constituting a check valve that restricts the direction of fuel flow.

A solenoid 200 as an actuator is held in the pump body 1 in the suction chamber 10a, and a plunger rod 201 and a spring 202 as an engaging member are arranged on the solenoid 200. When the solenoid 200 is OFF, the plunger rod 201 as the engaging member is biased by a spring 202 in a direction to open the suction valve 5. Since the biasing force of the spring 202 is larger than the biasing force of the suction valve spring 5a, when the solenoid 200 is OFF, the suction valve 5 is in an open state as shown in FIG. The fuel is led from the tank 50 to the fuel inlet of the pump body 1 by the low-pressure pump 51, adjusted to a constant pressure by the pressure regulator 52. After that, the pump body 1 is pressurized and is pumped from the fuel discharge port to the common rail 53. An injector 54, a relief valve 55, and a pressure sensor 56 are attached to the common rail 53. The injectors 54 are mounted according to the number of cylinders of the engine, and inject with signals from an engine control unit (ECU) 40. The relief valve 55 opens when the pressure in the common rail 53 exceeds a predetermined value, and prevents damage to the piping system.

  The lifter 3 provided at the lower end of the plunger 2 is pressed against the cam 100 by a spring 4. The plunger 2 is slidably held in the cylinder 20 and reciprocates by the cam 100 rotated by an engine cam shaft or the like to change the volume in the pressurizing chamber 12.

  Therefore, the capacity of the high-pressure fuel pump is determined by the reciprocating stroke amount of the plunger 2 determined by the cam 100 and the diameter of the plunger.

  The outer periphery of the cylinder 20 is held by a holder 21 and is fixed to the pump body 1 by screwing a screw threaded on the outer periphery of the holder 21 into a screw threaded on the pump body 1.

  A plunger seal 30 is provided at the lower end of the cylinder 20 in the figure, and shields fuel and cam lubricating oil.

  The outer periphery of the plunger seal 30 is held by the inner periphery of the lower end of the holder 21.

  When the suction valve 5 is closed during the ascending process of the plunger 2, the pressure in the pressurizing chamber 12 rises, whereby the discharge valve 6 is automatically opened and the fuel is pumped to the common rail 53.

  The suction valve 5 is automatically opened when the pressure in the pressurizing chamber 12 becomes lower than the fuel inlet, but the closing is determined by the operation of the solenoid 200.

  When the solenoid 200 is kept in the ON (energized) state, an electromagnetic force greater than the urging force of the spring 202 is generated and the plunger rod 201 as the engaging member is drawn toward the solenoid 200 side. 201 and the intake valve 5 are separated. In this state, the intake valve 5 is an automatic valve that opens and closes in synchronization with the reciprocating motion of the plunger 2. Therefore, during the compression process, the suction valve 5 is closed, and the fuel corresponding to the volume reduction of the pressurizing chamber 12 pushes the discharge valve 6 and is pumped to the common rail 53.

  On the other hand, when the solenoid 200 is kept OFF (non-energized), the plunger rod 201 as the engaging member is engaged with the intake valve 5 by the urging force of the spring 202, and the intake valve 5 is opened. Hold. Accordingly, even during the compression process, the pressure in the pressurizing chamber 12 is maintained at a low pressure that is substantially equal to that of the fuel introduction port, so that the discharge valve 6 cannot be opened, and the volume reduction of the pressurizing chamber 12 is reduced. The fuel is returned to the fuel inlet side through the intake valve 5. In other words, it overflows.

  Further, if the solenoid 200 is turned on during the compression process, the fuel is fed to the common rail 53 from this time. In addition, once the pressure feeding is started, the pressure in the pressurizing chamber 12 is increased. Thereafter, even if the solenoid 200 is turned off, the suction valve 5 is maintained in the closed state, and the suction process is automatically performed in synchronization with the start. Open the valve. Thereby, the discharge amount is controlled.

Accordingly, as the plunger 2 reciprocates, the fuel is sucked from the fuel suction joint 10 into the pressurizing chamber 12, the return process from the pressurizing chamber 12 to the suction chamber 10a (overflow process), and the common rail from the pressurizing chamber 12 to the common rail. The three steps of discharging to 53 are repeated.

  The ratio of the return process (overflow process) and the discharge process is changed at the solenoid ON timing, and only the amount of fuel required by the internal combustion engine is discharged at high pressure.

  Next, FIG. 3 shows an enlarged view around the suction valve 5 in the embodiment of the present invention, and FIG. 4 shows a view seen from the direction of the white arrow with respect to the sectional line AA in FIG.

  During the return process (overflow process), the fuel flows back from the pressurizing chamber 12 to the suction chamber 10a. Two fluid forces act on the intake valve 5 due to the backflowing fuel: dynamic pressure caused by the fuel hitting the back surface of the intake valve and valve closing force caused by pressure loss caused by the fuel passing through the intake valve 5. The biasing force of the spring 202 must be set to be greater than this fluid force. In some cases, the operation timing of the actuator must be adjusted depending on the magnitude of the fluid force.

  During the return process (overflow process), dynamic pressure is generated in the fuel passage between the opening 12a and the suction port 220. In particular, when the flow of the fuel that flows backward is fast, the fluid force (dynamic pressure) increases. If this dynamic pressure acts on the back surface of the intake valve 5, the urging force of the spring 202 must be increased accordingly.

  When the internal combustion engine is operated at a high speed, the cam 100 also rotates at a high speed, so that the speed of the backflowing fuel increases, the fluid force (dynamic pressure) increases, and the biasing force of the spring 202 increases accordingly. Must.

  Further, when the reciprocating stroke amount of the plunger 2 determined by the cam 100 or the diameter of the plunger is increased in order to increase the capacity of the high-pressure fuel pump, the speed of the backflowing fuel increases and the fluid force also increases. Therefore, the biasing force of the spring 202 must be increased.

  If the biasing force of the spring 202 is smaller than the fluid force, the intake valve 5 is closed without turning on the solenoid, and the fuel required by the injector is discharged to the common rail 53 at a high pressure.

  However, if the urging force of the spring 202 is large, a magnetic force greater than the urging force cannot be generated by the solenoid 200, and the flow rate cannot be controlled.

  For this reason, the magnetic force generated by the solenoid 200 must be greater than the biasing force of the spring 202.

  As a specific method, there is a method of increasing the driving power of the solenoid 200. However, in such a case, the power consumed by the solenoid 200 increases, and problems such as disconnection of the solenoid 200 due to heat generation occur.

  Although there is a method of increasing the magnetic force by increasing the number of turns of the solenoid 200, in this case, the responsiveness of the plunger rod 201 as an engaging member becomes slow, and the flow rate cannot be controlled.

  In this way, when the fluid force generated by the fuel flow during the return process (overflow process) generates dynamic pressure that acts on the back of the intake valve, the dynamic pressure changes in a complex manner depending on the engine speed and the like. If this happens, various problems as described above will occur.

Example 1
Next, a first embodiment of a specific configuration of the suction valve mechanism according to the present invention will be described.

  FIG. 3 is an enlarged view of the periphery of the suction valve 5 in the present invention, and FIG. 4 is a cross-sectional view taken along a cross-sectional line AA in FIG.

  The intake valve mechanism (5, 7) is configured as follows.

  A cylindrical portion 5g of the suction valve 5 formed in a bottomed cylindrical shape is slidably guided in a cylindrical space of an isolation member (shielding portion) 7 as a storage member forming an isolation member (shielding portion). And stored.

  In this sense, it can be said that the separating member (shielding portion) 7 constitutes a storage portion for the intake valve.

  In the cylindrical space of the separating member (shielding portion) 7 as a storage member, a spiral spring 5a is provided between the suction valve 5 and the bottomed cylindrical shape. The suction valve 5 is urged in a direction away from the isolation member (shielding portion) 7 as a storage member.

Thus, when the partition member 221 in which the suction port 220 is formed is combined so as to close the opening end of the cylindrical portion of the isolation member (shielding portion) 7 as a storage member, the seat surface 5h of the suction valve 5 is It is pressed against the partition member 221 in a state where a predetermined set load is applied in the direction of closing the suction port 220.

  An annular bottom plate portion 7b of a separating member (shielding portion) 7 as a storage member of the suction valve 5 has an area that can completely hide the annular projection portion viewed from the back side (pressure chamber side) of the suction valve 5.

  A side passage 5 b as a fuel passage from the opening 12 a to the suction port 220 is formed along the cylindrical side wall of the suction valve 5 in the isolation member (shielding portion) 7.

  This side passage 5b prevents the flow of fuel from the opening 12a of the pressurizing chamber 12 toward the suction port 220 of the suction chamber 10a from entering the inside of the cylindrical side wall of the suction valve 5, and by doing so, Since the separating member (shielding portion) 7 blocks the fuel that flows back during the returning process (overflow process), the suction valve 5 acting on the back surface 5f of the suction valve 5, that is, the surface on the pressurizing chamber side is pressed in the closing direction. The fluid force (dynamic pressure) can be reduced, and the biasing force of the spring 202 can be set low.

  The member 7 forming the isolation member (shielding portion) can be made of an aluminum alloy or a resin material. The seat surface 5h of the suction valve 5 is formed on the surface (surface) opposite to the back surface 5f of the suction valve 5 formed in a bottomed cylindrical shape.

  In addition, by providing the chamfer 5c at the annular peripheral edge of the intake valve 5, the flow of fuel becomes smooth, the pressure loss before and after the intake valve is reduced, and the fluid force can be further reduced.

  This chamfering is effective when it is an R-shaped chamfering or a C-shaped chamfering.

  Further, in the embodiment shown in FIG. 5, a fuel passage 5d for moving the fuel corresponding to the volume change generated in the inside 5e of the suction valve by opening and closing the suction valve 5 is provided. Thus, the suction valve 5 can be closed by the biasing force of the spring 5a.

  That is, in this embodiment, the pump body 1 is provided with a pressurizing chamber 12 for pressurizing fuel, and has an opening 12a formed at the inlet of the pressurizing chamber 12, and the pump body 1 has an intake chamber upstream of the opening 12a. 10a is formed, and the suction chamber 10a is partitioned into an upstream side and a downstream side by a partition member 221 in which a suction port 220 is formed. The suction chamber 10a is inhaled in a partition on the downstream side (pressure chamber side) of the suction chamber 10a. A valve mechanism (5, 7) is attached, and the suction valve mechanism (5, 7) is a cylindrical part that slidably guides the bottomed cylindrical suction valve 5 and the cylindrical part 5g of the suction valve 5. 70 is provided with a separating member (shielding portion) 7 as a valve housing member provided with 70, and a spring 5a that is located between the two and biases in a direction to separate them, and is provided on a surface opposite to the back surface 5f of the intake valve 5. The pressing force of the spring 5a is such that the formed sheet surface 5h closes the suction port 220. The pressure introduction port (fuel passage 5d) for allowing the static pressure of the fluid passage to act on the back surface 5f of the suction valve 5 is sucked in between the partition member 221 and the pump body 1 as used. It is provided in the valve mechanism (5, 7).

  Eventually, the fuel passage 5d serves as a pressure introduction passage for transmitting the static pressure of the fuel in the fuel flow path from the pressurizing chamber to the suction port to the suction valve interior 5e.

  By providing this pressure introduction passage, the pressure inside and outside the cylindrical suction valve 5 can be maintained during the opening / closing operation even when the suction valve 5 is stored in the isolation member (shielding portion) 7 as a cylindrical storage member. 5 The pressure inside 5e is smoothly balanced with the pressure in the external fuel flow path so as not to hinder the movement of the valve.

  When the internal combustion engine is operated at a high rotation speed, the cam 100 also rotates at a high rotation speed, so that the speed of the fuel that flows backward increases, but the fluid force is kept low.

  Therefore, the urging force of the spring 202 can be kept low, an electromagnetic force greater than the urging force of the spring 202 can be generated by the solenoid 200, and the flow rate can be controlled even when the internal combustion engine is operated at a high speed. .

  Also, when the reciprocating stroke amount of the plunger 2 determined by the cam 100 or the diameter of the plunger is increased in order to increase the capacity of the high-pressure fuel pump, the speed of the backflowing fuel is increased. The physical strength can be kept low, and the biasing force of the spring 202 can also be kept low.

  As a result, an electromagnetic force greater than the urging force of the spring 202 can be generated by the solenoid 200, and in order to increase the capacity of the pressure fuel pump, the reciprocating stroke amount of the plunger 2 determined by the cam 100, or the diameter of the plunger Even when the value is increased, the flow rate can be controlled.

  Furthermore, since the biasing force of the spring 202 is low, the load on the solenoid 200 can be reduced, so that the drive current of the solenoid 200 can be reduced and the power consumed by the solenoid 200 can be kept low.

  As a result, the solenoid 200 can be prevented from being burned out due to the heat generated by the solenoid 200 itself.

  Further, since the solenoid 200 can be reduced in size, it is possible to reduce the size and cost.

  The above effect is also effective in a pump in which the intake valve 5 and the plunger rod 201 as an engaging member are integrated by welding or the like.

(Example 2)
Next, another embodiment according to the present invention will be described.

  FIG. 5 is a longitudinal sectional view of a pump according to another embodiment.

  A separating member (shielding portion) 7 as a housing member for the intake valve 5 that prevents the flow of fuel is formed by a part of the pump body 1. As a result, no dynamic pressure is generated in the suction valve interior 5e, and the same effect as in the first embodiment can be obtained.

  Further, by providing the chamfer 5c on the suction valve 5, the fuel flow is smooth as in the first embodiment, the pressure loss before and after the suction valve 5 is reduced, and the fluid force can be reduced.

  It is also effective in a pump in which the suction valve 5 and the plunger rod 201 as an engaging member are integrated by welding or the like.

  In the above embodiment, the high-pressure fuel pump of the type that causes the fuel to overflow from the suction port has been described, but this technique can also be applied to a high-pressure pump provided with an overflow valve in addition to the suction valve.

  In other words, the suction valve itself is configured as a check valve, and an overflow port that communicates with the pressurizing chamber is provided separately, and this overflow port can be applied to an opening / closing control by an overflow valve driven by an actuator. .

  In the case of this type, the overflow control valve can be configured with the same configuration as the suction valve of the above embodiment.

  According to the present embodiment, the load on the solenoid can be reduced, and it is possible to cope with high rotation and a large flow rate.

  The embodiments of this example are summarized as follows.

(Embodiment 1)
A pressure chamber (12) communicating with the fuel intake joint (10) and the discharge joint (11);
A pressurizing member (plunger 2) for pumping fuel in the pressurizing chamber (12) to the discharge joint (11);
A suction valve (5) provided in the suction joint (10);
A discharge valve (6) provided in the discharge joint (11);
An engagement member (plunger rod 201) for controlling the valve closing operation of the suction valve (5) by engaging with the suction valve (5);
A variable flow type high pressure fuel pump provided with an actuator (solenoid 200) for applying a driving force to the engaging member (plunger rod 201),
Isolation member (shielding portion) (7, 7b) that prevents the flow of fuel flowing from the pressurizing chamber (12) from directly hitting the suction valve (5) between the suction valve (5) and the pressurizing chamber (12) And a projecting area of the separating member (shielding portion) (7, 7b) in the fuel flow direction is larger than a projected area of the suction valve (5) in the flow direction.

(Embodiment 2)
The variable flow rate high-pressure fuel pump according to Embodiment 1 is provided with a flow path (5d) in a member inside (5e) of a separating member (shielding portion) (7, 7b), and the flow path (5d) is a suction valve. (5) A variable flow type high-pressure fuel pump configured not to contact.

(Embodiment 3)
A part of the high-pressure fuel pump main body forms a separating member (shielding portion) (7) (see FIG. 7).

(Embodiment 4)
A pressure chamber (12) communicating with the fuel suction joint (10) and the discharge joint (11), a pressure member (plunger 2) for pumping fuel in the pressure chamber (12) to the discharge joint (11), and suction A suction valve (5) provided in the joint (10), a discharge valve (6) provided in the discharge joint (11), a plunger (plunger rod 201) formed integrally with the suction valve (5), a plunger (plunger A variable flow high pressure fuel pump including an actuator (solenoid 200) for applying a driving force to the rod 201),
Isolation member (shielding portion) (7, 7b) that prevents the flow of fuel flowing from the pressurizing chamber (12) from directly hitting the suction valve (5) between the suction valve (5) and the pressurizing chamber (12) And a projecting area of the separating member (shielding portion) (7, 7b) in the fuel flow direction is larger than a projected area of the suction valve (5) in the flow direction.

(Embodiment 5)
A variable flow type high-pressure fuel pump in which a side passage (5b) is provided in the inside (5e) of the separating member (shielding portion) (7, 7b), and the fluid passage does not contact the intake valve and the overflow valve.

(Embodiment 6)
A variable flow high pressure fuel pump in which a part of the high pressure fuel pump forms a separating member (shielding portion).

(Embodiment 7)
A variable flow type high-pressure fuel pump in which a chamfering is applied to a peripheral corner portion of an annular valve seat portion of a cylindrical suction valve or overflow valve so that the fuel flow is not separated.

(Embodiment 8)
A variable flow type high-pressure fuel pump in which a rounded chamfer is provided at a peripheral corner portion of a cylindrical valve seat portion of a cylindrical suction valve or overflow valve so that the fuel flow is not separated.

  According to such an embodiment, the following problems found in the prior art can be solved.

  The pump of the prior art has a structure that allows fuel to escape from the pressurizing chamber to the low-pressure pipe side in the flow rate control process. In this structure, since the intake valve is disposed between the pressurizing chamber and the low-pressure pipe, a dynamic pressure due to the fuel hitting the intake valve and a pressure loss due to the fuel passing through the intake valve are generated. Pressure loss including these dynamic pressures acts as a closing force on the intake valve. The valve closing force of the intake valve is large when the fuel flow rate is high, particularly when the pump volume is large or when the pump drive speed is high.

  If the closing force by the intake valve exceeds the operating force by the actuator, the actuator becomes inoperable and the pump cannot control the flow rate. From another point of view, there is a problem that the pump volume and the driving rotational speed are limited by the operating force of the actuator.

  As a means for increasing the operating force of the actuator, there is a method of increasing the drive current in the case of an electric actuator. However, in this case, the heat generation amount of the actuator increases, the power consumption increases, and the cost of the control device increases. There is. Furthermore, there is a concern that the responsiveness may decrease when the operating force of the actuator is increased. In this case, the energization time of the actuator increases, and as a result, the amount of heat generated by the actuator further increases.

  On the other hand, since it is comprised like the said embodiment in an Example, there can exist the following effects.

  A separating member (shielding portion) is provided between the pressurizing chamber and the suction valve of the variable flow type high-pressure fuel pump to prevent the fuel escaping from the pressurizing chamber from directly hitting the suction valve. In order to sufficiently cover the intake valve, the separating member (shielding portion) has a projected area in the fuel flow direction larger than the projected area in the flow direction of the intake valve. By doing so, dynamic pressure is generated at the isolation member (shielding portion), and no dynamic pressure is generated at the suction valve, so that the fluid force acting on the suction valve can be reduced.

  Specifically, the pump body is provided with a pressurizing chamber for pressurizing fuel, and has an opening formed at the inlet of the pressurizing chamber. The pump body has a suction chamber formed upstream of the opening. Is divided into an upstream side and a downstream side by a suction valve mechanism attached to the pump body, and the suction valve mechanism has an overall shape that slidably guides the bottomed cylindrical suction valve and the cylindrical portion of the suction valve. A partition member in which a suction port is formed closes the opening end of the tubular portion of the valve storage member. The seat surface formed on the surface opposite to the bottom surface of the suction valve is assembled between the partition member and the pump body so that the pressing force of the spring acts in the direction of closing the suction port. In order to apply the static pressure of the pressurizing chamber to the bottom of the suction valve A plurality of pressure inlets are provided along the axial direction of the suction valve of the suction valve mechanism or the cylindrical portion of the valve storage member, and the inside and outside of the suction valve communicate with each other through this groove, so The pressure is balanced smoothly and does not support the movement of the valve.

  Desirably, a flow path is provided in a part of the member forming the isolation member (shielding portion), and the flow path does not contact the suction valve. By doing so, the fuel escaping from the pressurizing chamber passes through the flow path formed in the isolation member (shielding portion), and it is completely impossible to generate dynamic pressure in the suction valve.

  More preferably, the isolation member (shielding portion) is formed by a part of the pump body. By doing so, the same effect as the above embodiment can be realized with a small number of parts.

  More preferably, the corner portion of the intake valve is C-chamfered or R-chamfered so as not to separate the fuel flow. By doing so, the fuel flow passing through the intake valve is less likely to be peeled off. As a result, pressure loss before and after the intake valve is reduced, and the acting force of the fluid acting on the intake valve can be reduced.

  Further, the above embodiment can be similarly applied to a high-pressure fuel pump in which a suction valve and a plunger rod as an engaging member are integrally formed.

  By doing so, it is possible to reduce the fluid force due to the dynamic pressure at the time of overflow of the fuel acting on the suction valve and the overflow valve.

  Thus, according to the present embodiment, the back surface of the suction valve and the overflow valve is protected from the dynamic pressure of the fluid from the pressurizing chamber toward the suction port. It was possible to prevent the opening and closing operation from becoming unstable under the influence of In addition, a pressure introduction port is provided in the storage part and the isolation member (shielding part) so that the static pressure of the fuel acts properly on the back surface of the intake valve and the overflow valve, so that these valves are isolated from the flow path. Therefore, the problem that the movement of these valves is alienated when stored in the storage section or surrounded by the isolation member (shielding section) can be prevented.

1 is a vertical sectional view of a first embodiment according to the present invention. The fuel-injection system block diagram. The enlarged view of the suction valve periphery in a 1st Example. Sectional drawing with respect to sectional line AA in FIG. The vertical sectional view of the second embodiment having the same cross section as FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pump main body, 2 ... Plunger, 3 ... Lifter, 4, 5a, 6a, 202 ... Spring, 5 ... Suction valve, 5b ... Side passage, 5c ... Chamfering, 6 ... Discharge valve, 7 ... Isolation member (shielding part) DESCRIPTION OF SYMBOLS 10 ... Suction joint, 11 ... Discharge joint, 12 ... Pressure chamber, 50 ... Fuel tank, 51 ... Low pressure pump, 52 ... Low pressure regulator, 53 ... Common rail, 54 ... Injector, 100 ... Cam, 200 ... Solenoid, 201 ... plunger rod.

Claims (13)

A pressurizing chamber for pressurizing the fluid;
In the pressurization chamber side of the suction port to open and close the suction port formed at the inlet of the pressurization chamber, provided with a suction valve biased in a direction to close the suction port by a spring,
A high-pressure fuel pump provided with an isolation member in a fluid passage between the pressurizing chamber and the suction port and isolating a back surface portion of the suction valve from the fluid passage. 2. The high-pressure fuel pump according to claim 1, wherein the isolation member is provided with a pressure introduction passage for applying a static pressure of the fluid passage to a back surface of the suction valve. The pump body has a pressurizing chamber that pressurizes fuel,
An opening formed at the inlet of the pressurizing chamber;
The pump body is formed with a suction chamber upstream of the opening,
The suction chamber is divided into an upstream side and a downstream side by a suction valve mechanism attached to the pump body,
The suction valve mechanism has a bottomed cylindrical suction valve, a cylindrical valve storage member that slidably guides the cylindrical portion of the suction valve, and is biased in a direction that is positioned between the two and separating them. With springs,
The partition member formed with the suction port is combined so as to close the opening end of the tubular portion of the valve storage member,
The seat surface of the suction valve is pressed against the partition member in a state in which a predetermined set load is applied in a direction of closing the suction port;
A high-pressure fuel pump in which an outer periphery of the valve housing member is secretly fixed to the pump body. 4. The high-pressure fuel pump according to claim 3, wherein the suction valve mechanism is provided with a pressure inlet for applying a static pressure of the pressurizing chamber to the bottom surface of the suction valve. In one of claims 1 and 3,
The high-pressure fuel pump in which the valve opening force of the intake valve is determined by the pressure difference between the upstream and downstream fuel of the intake port and the pressing force of the spring. In one of claims 1 and 3,
The intake valve is a high-pressure fuel pump configured such that the opening / closing timing is controlled by an electromagnetic plunger that is electromagnetically operated from a downstream side of the intake port. In what is described in claim 3,
The intake valve is configured such that the opening and closing timing is controlled by an electromagnetic plunger that is electromagnetically operated from the downstream side of the intake port,
A partition member formed with the suction port is provided integrally with the electromagnetic plunger mechanism,
A high-pressure fuel pump in which a suction valve mechanism is formed in the suction chamber by fixing the electromagnetic plunger mechanism to the pump body, and the suction chamber is partitioned into an upstream side and a downstream side by the suction valve mechanism. What is described in claim 4,
The high-pressure fuel pump, wherein the pressure introduction passage is formed by a groove extending in the axial direction between the cylindrical portion of the intake valve and the valve storage member. In any one of claims 1 and 2,
A high-pressure fuel pump in which a part of the high-pressure fuel pump body forms the isolation member. In any of claims 3 or 4,
A high-pressure fuel pump in which a part of the high-pressure fuel pump main body forms the valve housing member. 4. The high-pressure fuel pump according to claim 1, wherein the intake valve has an annular shape, and a peripheral corner portion of the annular intake valve is chamfered. A pressurizing chamber for pressurizing the fluid;
An overflow valve is provided on the pressurizing chamber side of the opening to open and close the opening communicating with the pressurizing chamber. The overflow valve opens the opening by moving to the pressurizing chamber side and causes the fuel to overflow from the opening. In
A high-pressure fuel pump provided with a separating member in a fluid passage between the pressurizing chamber and the opening and isolating a back surface portion of the overflow valve from a dynamic pressure of fuel flowing through the fluid passage. 13. The high-pressure fuel pump according to claim 12, wherein the isolation member is provided with a pressure introducing passage for applying a static pressure in the pressurizing chamber to a back surface of the overflow valve.

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