JP5178618B2 - High pressure fuel supply pump - Google Patents

Description

  The present invention relates to a high-pressure fuel supply pump that pumps high-pressure fuel to a fuel injection valve of an in-cylinder direct fuel injection internal combustion engine, and more particularly, to an electromagnetically driven valve mechanism that opens and closes a fluid passage (for example, a variable capacity electromagnetic that controls a fuel supply amount). The present invention relates to a high-pressure fuel supply pump provided with a drive valve mechanism.

  An electromagnetically driven valve mechanism such as an electromagnetically driven variable displacement valve mechanism of a conventional high-pressure fuel supply pump described in the pamphlet of International Publication No. WO00 / 47888 includes a valve mechanism operated by an electromagnetic plunger, An electromagnetic drive mechanism having a cylindrical electromagnetic coil for magnetically driving the electromagnetic plunger is integrally combined in the mounting holder to form a unit, and this unitized electromagnetic drive type valve mechanism is molded into the pump housing. It is inserted into the cylindrical case part and fixed to the pump housing by the force of fastening the screw of the mounting holder.

  The body and the unit are sealed by a sealing mechanism such as an O-ring.

International Publication WO00 / 47888 Pamphlet

  In the above prior art configuration, the connector for supplying power to the electromagnetic coil is integrally attached to the outer periphery of the electromagnetic drive device by resin molding. When the electromagnetically driven valve mechanism is screwed to the pump housing, the position of the connector is determined by the screwing end point position, and there is a problem that the connector cannot be disposed at an arbitrary position with respect to the screwing end point position.

  An object of the present invention is to make it possible to freely set the position of the connector.

  The above object of the present invention is to provide an electromagnetically driven valve mechanism and a pump housing having a fitting portion that can be assembled to the pump housing at any position in the rotational direction of the energizing connector. Furthermore, this is achieved by providing a seal portion that maintains the airtightness between the fuel passage and the atmosphere.

  The valve mechanism part of the electromagnetically driven valve mechanism and the electromagnetic mechanism part provided with the connector are formed separately, and the valve mechanism part is fixed to the body in an airtight manner, and then the electromagnetic mechanism part provided with the connector is This is achieved by press-fitting to the mechanism.

  According to the present invention, when the electromagnetically driven valve mechanism provided with the connector is fixed to the pump housing, an effect that the positions of the pump housing and the connector can be freely set is obtained.

It is a system diagram showing an example of a fuel supply system of an internal combustion engine in which a high-pressure fuel supply pump is used. 1 is a longitudinal sectional view of a first embodiment of a high-pressure fuel supply pump in which the present invention is implemented. It is a longitudinal cross-sectional enlarged view of 1st Example of the high-pressure fuel supply pump with which this invention was implemented. It is a disassembled perspective view of 1st Example of the high-pressure fuel supply pump with which this invention was implemented. It is a longitudinal cross-sectional view of 2nd Example of the high pressure fuel supply pump with which this invention was implemented. It is a cross-sectional view of the third embodiment of the high-pressure fuel supply pump in which the present invention is implemented.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

(First embodiment)
The first embodiment of the present invention will be described in detail with reference to FIGS. First, the configuration and operation of the high-pressure fuel supply pump will be described with reference to FIGS.

  A portion surrounded by a broken line indicates a high-pressure pump housing, and the mechanism and components shown in the broken line indicate that the pump housing 1 is integrated.

  The fuel in the fuel tank 20 is pumped up by the feed pump 21 and sent to the suction joint 10 a of the pump housing 1 through the suction pipe 28. At that time, the intake fuel to the pump housing 1 is adjusted to a constant pressure by the pressure regulator 22.

  The fuel that has passed through the suction joint 10a reaches the suction port 30a of the electromagnetically driven valve mechanism 30 that constitutes a variable capacity mechanism via the pressure pulsation reducing mechanism 9 and the suction passage 10d.

  The electromagnetically driven valve mechanism 30 includes a solenoid 30b formed of an annular or cylindrical electromagnetic coil. When the solenoid 30b is energized, the electromagnetic plunger 30c moves to the right in FIG. The state where 33 is compressed is maintained. A suction valve body 31 attached to the tip of the electromagnetic plunger 30c opens a suction port 32 connected to the pressurizing chamber 11 of the high-pressure pump. The suction valve body 31 is configured separately from the electromagnetic plunger 30c, and is located on the opposite side of the electromagnetic plunger 30c with respect to the suction valve body 31, and the suction valve body is formed on the valve seat formed on the end surface of the suction port 32. Another spring for pressing 31 may be provided.

  When the solenoid 30b is not energized and there is no fluid differential pressure between the suction passage 10d (suction port 30a) and the pressurizing chamber 11, the urging force of the spring 33 (or the suction valve body 31 is applied). On the other hand, the suction valve body 31 is biased in the valve closing direction by another spring which is located on the opposite side of the electromagnetic plunger 30c and presses the suction valve body 31 against the valve seat formed on the end face of the suction port 32). The suction port 32 is closed by being pressed against the valve seat formed on the end surface of the suction port 32.

  Specifically, it operates as follows.

  When the piston plunger 2 is displaced downward in FIG. 1 due to the rotation of the cam and is in the suction process state, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. When the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction passage 10d (suction port 30a) in this step, the valve opening force (suction valve body 31 shown in FIG. Force to displace to the right).

  By the valve opening force due to this fluid differential pressure, the suction valve body 31 is set to open over the biasing force of the spring 33 and open the suction port 32.

  In this state, when a control signal from the engine control unit 27 (hereinafter referred to as ECU) is applied to the electromagnetically driven valve mechanism 30, a current flows through the solenoid 30 b of the electromagnetically driven valve mechanism 30, and magnetism is applied. The electromagnetic plunger 30c moves to the right in FIG. 1 by the force, and the state where the spring 33 is compressed is maintained. As a result, the state in which the suction valve body 31 opens the suction port 32 is maintained.

  When the piston plunger 2 finishes the suction process and shifts to the compression process while maintaining the application state of the input voltage to the electromagnetically driven valve mechanism 30, the piston plunger 2 moves to the compression process (upward in FIG. 1). In the state), the energizing state of the solenoid 30b is maintained, so that the magnetic biasing force is maintained, and the suction valve body 31 is still open.

  The volume of the pressurizing chamber 11 decreases with the compression movement of the piston plunger 2. In this state, the fuel once sucked into the pressurizing chamber 11 passes through the suction valve body 31 that is opened again, and the suction passage 10 d ( Since the pressure is returned to the suction port 30a), the pressure in the pressurizing chamber does not increase. This process is called a return process.

  In this state, when the control signal from the ECU 27 is released and the energization to the solenoid 30b is cut off, the magnetic biasing force acting on the electromagnetic plunger 30c is erased after a certain time (after magnetic and mechanical delay time). Is done. Since the biasing force by the spring 33 is acting on the suction valve body 31, the suction valve body 31 closes the suction port 32 by the biasing force by the spring 33 when the electromagnetic force acting on the electromagnetic plunger 30 c disappears. When the suction port 32 is closed, the fuel pressure in the pressurizing chamber 11 increases with the upward movement of the piston plunger 2 from this time. When the pressure in the fuel discharge port 12 or higher is reached, high pressure discharge of the fuel remaining in the pressurizing chamber 11 is performed via the discharge valve unit 8 and supplied to the common rail 23. This process is called a discharge process. That is, the compression process of the piston plunger 2 (the ascending process from the lower start point to the upper start point) includes a return process and a discharge process.

  And the quantity of the high-pressure fuel discharged can be controlled by controlling the timing which cancels | releases electricity supply to the solenoid 30b of the electromagnetically driven valve mechanism 30. FIG. If the timing for releasing the energization of the solenoid 30b is advanced, the ratio of the return process in the compression process is small and the ratio of the discharge process is large. That is, the amount of fuel returned to the suction passage 10d (suction port 30a) is small, and the amount of fuel discharged at high pressure is large. On the other hand, if the timing for releasing the input voltage is delayed, the ratio of the return process in the compression process is large and the ratio of the discharge process is small. That is, the amount of fuel returned to the suction passage 10d is large, and the amount of fuel discharged at high pressure is small. The timing for releasing the energization of the solenoid 30b is controlled by a command from the ECU.

  With the configuration described above, the amount of fuel discharged at high pressure can be controlled to the amount required by the internal combustion engine by controlling the timing at which the energization of the solenoid 30b is released.

  A discharge valve unit 8 is provided at the outlet of the pressurizing chamber 11. The discharge valve unit 8 includes a seat member 8a, a discharge valve 8b, and a discharge valve spring 8c. When there is no fuel differential pressure in the pressurizing chamber 11 and the fuel discharge port 12, the discharge valve 8b is urged by the discharge valve spring 8c. The valve is pressed against the seat member 8a and is in a closed state. Only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure in the fuel discharge port 12, the discharge valve 8 b opens against the discharge valve spring 8 c, and the fuel in the pressurization chamber 11 is discharged from the fuel discharge port. 12 is discharged to the common rail 23 through a high pressure.

  Thus, the fuel guided to the suction joint 10 a is pressurized to a high pressure by the reciprocating motion of the piston plunger 2 in the pressurizing chamber 11 of the pump housing 1, and is pumped from the fuel discharge port 12 to the common rail 23.

  An injector 24 and a pressure sensor 26 are attached to the common rail 23. The injectors 24 are mounted in accordance with the number of cylinders of the internal combustion engine, and are opened and closed according to a control signal from an engine control unit (ECU) 27 to inject fuel into the cylinders.

  The pump housing 1 is further provided with a relief channel 210 that communicates the downstream side of the discharge valve 8b and the suction passage 10c.

  The relief flow path 210 is provided with a relief valve 202 that restricts the flow of fuel in only one direction from the discharge flow path to the suction passage 10c. The relief valve 202 is pressed against the relief valve seat 201 by a relief spring 203 that generates a pressing force. When the pressure difference between the suction chamber and the relief passage 211 exceeds a specified pressure, the relief valve 202 is It is set so as to open the valve away from the seat 201. The orifice plate 214 is provided in the middle of the relief passage 210, and prevents the relief valve 202 from opening sensitively due to a sudden change in pressure in the relief passage 210.

  When an abnormally high pressure is generated in the common rail 23 or the like due to a failure of the injector 24 or the like, if the differential pressure between the relief flow path 210 and the suction passage becomes equal to or higher than the opening pressure of the relief valve 202, the relief valve 202 is opened and The resulting fuel is returned from the relief flow path 210 to the suction passage, and the high-pressure section piping such as the common rail 23 is protected.

  Hereinafter, the configuration and assembly method of the electromagnetically driven valve mechanism 30 will be described in detail with reference to FIGS.

  The electromagnetically driven valve mechanism 30 is configured as follows.

  The electromagnetically driven valve mechanism 30 includes an electromagnetic mechanism part 310 having a solenoid 30b, a valve mechanism part 320 operated by an electromagnetic plunger 30c, and the valve mechanism part 320 fixed to the pump housing 1 to seal fuel and electromagnetically. The outer peripheral yoke 330 has a function of press-fitting and fixing the mechanism portion 310.

  The electromagnetic mechanism 310 includes a solenoid 30b, a connector 312 for passing a current through the solenoid 30b, and an upper yoke 311 having a press-fitting portion with the outer yoke 330.

  The valve mechanism 320 includes an electromagnetic plunger 30c, a valve body 31 attached to the tip of the electromagnetic plunger 30c, a suction port 32 having a seat surface in contact with the valve body 31, and the valve body 31 in the right direction in FIG. A spring (33) that always applies a force (valve closing force) to be displaced, a core (A) 321 having a mechanism that contacts the pump housing 1 and seals the fuel by the screw fastening force of the outer peripheral yoke 330, and a core (A) 321 An anchor 322 that sets the stroke amount of the electromagnetic plunger 30c by contact, a rod guide 323 that guides the electromagnetic plunger 30c, and a core (B) that covers the electromagnetic plunger 30c, the anchor 322, and the rod guide 323 324, and a seal ring 325 that is welded to the core (A) 321 and the core (B) 324 to maintain airtightness.

  The electromagnetically driven valve mechanism 30 is assembled as follows.

  The valve mechanism 320 is press-fitted into the pump housing 1. Thereafter, screws are fastened by using the internal thread portion of the cylindrical case portion 340 formed or connected to the body and the external thread portion of the outer peripheral yoke 330. By screw fastening, the valve mechanism 320 is fixed and the seal mechanism functions to seal the fuel. Thereafter, the electromagnetic mechanism part 310 provided with the connector 312 is press-fitted and fixed to the valve mechanism part 320. At that time, the connector 312 can be arranged in an arbitrary direction.

  The magnetic path after the assembly is secured by the outer peripheral yoke 330, the upper yoke 311, the core (B) 324, the anchor 322, and the core (A) 321 which are magnetic parts.

(Second embodiment)
Next, a second embodiment will be described.

  FIG. 5 shows that the tubular case portion 340 is removed from the embodiment of FIG. 2 and the pump housing 1 and the core (A) 321 of the valve mechanism portion 320 are laser-welded to fix the valve mechanism portion 320 and fuel. It is the 2nd Example which is sealing. The outer yoke 330 is also fixed to the core (A) 321 by laser welding.

  The magnetic path after the assembly is secured by the outer peripheral yoke 330, the upper yoke 311, the core (B) 324, the anchor 322, and the core (A) 321 which are magnetic parts.

(Third embodiment)
Next, a third embodiment will be described.

  FIG. 6 shows a third embodiment in which the outer yoke 330 is replaced with a flange-shaped outer yoke 330a and an electromagnetically driven valve mechanism is bolted to the pump housing 1 in the embodiment of FIG.

  In the prior art, when the pump housing and the flange-shaped outer yoke are fixed with bolts, the connector and the outer yoke are integrated, and the connector cannot be set at an arbitrary position. However, in the case of the third embodiment shown in FIG. 6, the position of the connector 312 can be arbitrarily set because the electromagnetic drive device 310 provided with the outer yoke 330a and the connector 312 is separate.

  In the above embodiment, the valve mechanism portion and the electromagnetic mechanism portion have been described separately. However, the valve mechanism portion and the electromagnetic mechanism portion are configured as a unit, and the mounting hole on the pump housing side for mounting this unit is provided. A cylindrical shape and an outer peripheral wall surface that fits into the hole may be provided on the unit side.

  In this case, the gap of the fitting part between the pump housing and the unit is sealed by welding the entire circumference.

  Although the present invention has been described with respect to an intake valve of a high-pressure fuel supply pump of an internal combustion engine configured as an electromagnetically driven discharge capacity variable mechanism configured by an electromagnetically driven valve mechanism, an electromagnetic relief valve mechanism, an electromagnetic discharge valve mechanism, or It can also be used for a spill fuel control valve mechanism.

DESCRIPTION OF SYMBOLS 1 Pump housing 2 Piston plunger 5 Cam 8 Discharge valve unit 8a Seat member 8b Discharge valve 8c Discharge valve spring 9 Pressure pulsation reduction mechanism 10a Suction joint 10d Suction passage 11 Pressurization chamber 12 Fuel discharge port 20 Fuel tank 21 Feed pump 22 Pressure regulator 23 Common rail 24 Injector 26 Pressure sensor 27 Engine control unit 30 Electromagnetic drive type valve mechanism 30a Suction port 30b Solenoid 30c Electromagnetic plunger 31 Valve body 32 Suction port 33 Spring 201 Relief valve seat 202 Relief valve 210 Relief flow path 211 Relief flow path 214 Orifice plate 310 Electromagnetic mechanism 311 Upper yoke 312 Connector 320 Valve mechanism 321 Core (A)
322 Anchor 323 Rod guide 324 Core (B)
325 Seal ring 330 Outer yoke 330a Flange outer yoke 340 Cylindrical case

Claims (5)

A fuel passage formed in the pump housing,
An electromagnetically driven valve mechanism fixed to the pump housing and blocking and communicating with the fuel passage, and a high pressure fuel pump provided with an energizing connector provided in the electromagnetically driven valve mechanism,
The electromagnetically driven valve mechanism and the pump housing are:
The pump housing includes a fitting portion configured to be assembled at an arbitrary position in the rotation direction of the energizing connector,
Furthermore, it has a seal portion that maintains an airtightness between the fuel passage and the atmosphere,
The electromagnetically driven valve mechanism includes an electromagnetic mechanism unit including a cylindrical electromagnetic coil and the connector, and a valve mechanism unit that is magnetically driven by the electromagnetic mechanism unit. The high pressure is fixed to the pump housing in an airtight manner, and the electromagnetic mechanism portion includes the fitting portion configured to be assembled at an arbitrary position in the rotation direction with respect to the valve mechanism portion. Fuel supply pump. The high-pressure fuel supply pump according to claim 1,
The valve mechanism is
A valve element that sits on and separates from a valve seat disposed in the fluid passage to shut off and open the fluid passage;
A housing part constituting a magnetic path together with the electromagnetic mechanism part;
An electromagnetic plunger housed in the housing and electromagnetically driven by the electromagnetic mechanism ,
A high pressure fuel supply pump configured to operate the valve element by the electromagnetic plunger. In claim 2 ,
The electromagnetic plunger is a high-pressure fuel supply pump having one end provided with an anchor made of a magnetic material and the other end configured to operate the valve element. The fitting portion according to claim 1, wherein the fitting portion fits a cylindrical outer peripheral wall surface provided on an outer periphery of the electromagnetically driven valve mechanism in a cylindrical hole formed in the pump housing. Consists of
The seal portion is a high-pressure fuel supply pump configured by a joint portion in which the entire circumference of the fitting portion between the pump housing and the electromagnetically driven valve mechanism is joined by welding. The method for assembling the high-pressure fuel supply pump according to claim 1,
A method for assembling a high-pressure fuel supply pump, wherein after fixing the valve mechanism portion to the pump housing, the electromagnetic mechanism portion provided with the connector is fixed to the valve mechanism portion.

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