JP2010236573A - Flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow control valve attaining good flow controllability by forming a valve seat on a conical surface. <P>SOLUTION: A supply pump, which pressurizes fuel supplied to a common rail provided with a common rail fuel injection system, has a feed pump, which pumps up the fuel from a fuel tank, and a high-pressure pump, which pressurizes the fuel pumped up by the feed pump. An intake regulation valve 50, which controls a fuel amount supplied to a pressurizing chamber, is provided between the feed pump and the high-pressure pump. The intake regulation valve 50 has a valve part 51, which controls a flow rate. The valve part 51 is made up of a valve body 52, a diaphragm 61, etc. The valve body 52 has the conical surface 57 between the inlet side passage 55 and the valve chamber 54. The valve seat 58, on which the contact part 62 of the diaphragm 61 is seated, is formed on the conical surface 57. A rod 80, which is driven and controlled by an electromagnetic actuator 63 that seats the contact part 62 on the valve seat 58, is provided at the side opposite to the valve seat 58 of the diaphragm 61. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a flow control valve.

  A valve body, an inlet side passage connected to the valve chamber, an outlet side passage connected to the valve chamber, a valve body having a valve seat at a connection portion between the inlet side passage and the valve chamber, and an elastic material It is installed opposite the valve seat, and the flow of fluid from the inlet side passage to the outlet side passage is blocked by seating on the valve seat, and from the inlet side passage to the outlet side passage by separating from the valve seat A flow control valve having a diaphragm that permits fluid flow, a rod that is installed on the opposite side of the valve seat of the diaphragm, and that moves the diaphragm in the seating direction, and driving means that moves the rod in the seating direction is known. (See Patent Document 1).

JP 2003-83462 A

  According to the above-mentioned Patent Document 1, the connecting portion is a flat surface, and the valve seat is formed on this flat surface. In this document, the diaphragm controls the flow rate of the fluid from the inlet side passage to the outlet side passage by being seated on the plane described above. However, if the surface on which the diaphragm is seated / separated is a plane, the cross-sectional area of the gap through which the fluid formed between the diaphragm and the plane on which the valve seat is formed with respect to the diaphragm seating direction is the rod's cross-sectional area. It is abrupt with respect to displacement in the take-off and seating direction, and the flow rate controllability is very poor.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a flow rate control valve with good flow rate controllability.

  The invention according to claim 1 is a valve body having a valve chamber, an inlet-side passage connected to the valve chamber, and an outlet-side passage connected to the valve chamber, and is any one of the inlet-side passage and the outlet-side passage. The wall surface of the connection part between the specific passage and the valve chamber is a conical surface, the valve body is formed with a valve seat on the conical surface, and is made of an elastic material so as to face the valve seat. A contact portion that is seated on the valve seat, and elastically deforms. When the contact portion is seated on the valve seat, the flow of fluid from the inlet-side passage to the outlet-side passage is interrupted, and the restoring force of the elastic material When the abutment part is separated from the valve seat by the elastic thin film body that permits the flow of fluid from the inlet side passage to the outlet side passage, the elastic thin film body is installed on the opposite side of the valve seat of the elastic thin film body. The contact portion of the elastic thin film body is moved along the direction of seating on the seat and the direction of seating away from the valve seat. Between the state where the contact portion is seated on the valve seat and the maximum displacement in the direction of separation of the rod member. Drive means for controlling the position to a predetermined position.

  According to this invention, the valve seat on which the elastic thin film body is detached and formed is formed on the connection portion between the valve chamber and any one of the inlet-side passage and the outlet-side passage having a conical surface. The elastic thin film body is disposed so as to face the valve seat so that the contact portion can be seated on the valve seat. When the valve seat is thus formed on the conical surface, the amount of change in the cross-sectional area of the gap through which the fluid formed between the elastic thin film body and the conical surface per unit displacement of the rod member is Compared to the case where the valve seat is formed on a flat surface, it can be made smaller. Since the amount of change in cross-sectional area is relatively small, the amount of change in flow rate to be controlled is also small. Therefore, the controllability of the flow rate can be improved compared to the case where the valve seat is formed on the plane.

  The invention according to claim 2 is characterized in that the elastic thin film body is installed so as to define a valve chamber. According to this invention, since the elastic thin film body is installed so as to delimit the valve chamber, it is possible to suppress the fluid that has flowed into the valve chamber from entering the driving means. For this reason, generation | occurrence | production of the malfunction of the drive means by the fluid invading can be suppressed.

  The invention according to claim 3 is characterized in that the elastic thin film body is made of rubber. According to this invention, since the elastic thin film body is made of rubber, even if pulsation occurs in the fluid flowing into the valve chamber via the inlet side passage, the elastic thin film body can reduce the pulsation of the fluid. it can.

  The invention described in claim 4 is characterized in that the outer diameter of the rod member is smaller than the inner diameter of the conical surface on the valve chamber side and larger than the inner diameter of the conical surface on the specific passage side. According to this invention, the outer diameter of the rod member is smaller than the inner diameter of the conical surface on the valve chamber side and larger than the inner diameter of the conical surface on the specific passage side. According to this configuration, the contact portion of the elastic thin film body can be reliably seated on the valve seat formed on the conical surface.

  The invention according to claim 5 is characterized in that the end of the bar member in contact with the elastic thin film body is a spherical surface. According to the present invention, since the load on the elastic thin film body can be reduced, the life of the elastic thin film body can be extended.

It is the block diagram which showed the common rail type fuel injection system to which the flow control valve by one Embodiment of this invention is applied. It is the block diagram which showed the fuel system in the supply pump provided in a common rail type fuel injection system. It is sectional drawing which shows the structure of the intake metering valve (flow control valve) shown in FIG. It is sectional drawing which shows the principal part of the intake metering valve shown in FIG. 2, and is sectional drawing which shows the state at the time of valve closing and valve opening. It is sectional drawing which shows the principal part of the suction metering valve by a comparative example, and is sectional drawing which shows the state at the time of valve closing and valve opening. It is the graph which compared the relationship between the displacement amount of each rod of the suction metering valve by this embodiment, and the suction metering valve by a comparative example, and the opening area of the clearance gap formed with a valve seat and a diaphragm.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a common rail fuel injection system to which a flow control valve according to an embodiment of the present invention is applied. FIG. 2 is a configuration diagram showing a fuel system in a supply pump provided in the common rail fuel injection system.

  The fuel injection system to which the flow control valve according to the present embodiment is applied is a fuel injection system for an internal combustion engine (hereinafter simply referred to as an engine) such as a multi-cylinder diesel engine, and has a common rail type having a common rail for accumulating high-pressure fuel. It is a fuel injection system.

  The common rail fuel injection system of this embodiment injects fuel into a four-cylinder engine. In this fuel injection system, as shown in FIG. 1, pressure is accumulated in a supply pump 10 that pressurizes fuel pumped from a fuel tank 30, a common rail 21 that accumulates high-pressure fuel pressurized by the supply pump 10, and a common rail 21. It comprises an injector 23 for injecting the high-pressure fuel being injected into the combustion chamber of each cylinder, a supply pump 10, a control device 40 for controlling the injector 23, and the like.

  The supply pump 10 sucks up the fuel in the fuel tank 30 with a built-in feed pump, pressurizes the fuel sucked up with a built-in high-pressure pump, and pressurizes the pressurized fuel via the fuel pipe 33 to the common rail 21. Send to. The supply pump 10 has a pump drive shaft 11 that drives the pump. The pump drive shaft 11 is rotationally driven by an engine crankshaft or camshaft.

  A filter 31 that captures foreign matter contained in the fuel sucked up by the feed pump is provided in the middle of the fuel pipe 32 connecting the suction port of the feed pump of the supply pump 10 and the fuel tank 30. The control device 40 controls the amount of fuel delivered from the high-pressure pump so that the fuel pressure in the common rail 21 becomes an optimum pressure for engine operation.

  The common rail 21 is a pressure accumulation container that accumulates high-pressure fuel sent from the supply pump 10 via the fuel pipe 33. The common rail 21 distributes the high-pressure fuel accumulated through the fuel pipe 34 to the injectors 23 installed in each cylinder.

  The common rail 21 is provided with a pressure limiter 22. The pressure limiter 22 is connected to a return pipe 35 that leads to the fuel tank 30, and operates when the pressure in the common rail 21 becomes abnormally high, and releases the pressure in the common rail 21 through the return pipe 35.

  The injector 23 is mounted corresponding to each cylinder of the engine, and injects high-pressure fuel accumulated in the common rail 21 in a mist form into the combustion chamber. The injector 23 includes an electromagnetic valve 26 that controls fuel injection from a nozzle hole provided at the tip. The control device 40 controls the electromagnetic valve 26 so that the injection timing, the injection amount, and the injection rate of the fuel injected from the nozzle hole are in accordance with the operating state of the engine.

  As an example, the injector 23 includes an injection nozzle portion 24 that incorporates a valve body that opens and closes an injection hole, and a drive portion 25 that drives the valve body to open and close. The electromagnetic valve 26 is built in the drive unit 25. The injection nozzle portion 24 accumulates high-pressure fuel sent from the fuel pipe 34 and has a fuel reservoir portion communicating with the injection hole. The end of the valve body on the nozzle hole side is accommodated in the fuel reservoir. The valve body is urged in the valve opening direction by the fuel pressure in the fuel reservoir.

  The drive unit 25 has a command piston that controls opening and closing of the valve body. The drive unit 25 is provided with a pressure control chamber for accumulating fuel pressure for energizing the valve body in the valve closing direction via the command piston at the end opposite to the valve body of the command piston. High pressure fuel is sent from the fuel pipe 34 to the pressure control chamber. The electromagnetic valve 26 provided in the drive unit 25 increases or decreases the fuel pressure accumulated in the pressure control chamber by opening and closing.

  When the electromagnetic valve 26 is closed and the fuel pressure in the pressure control chamber is substantially the same as the fuel pressure in the common rail 21, the command piston is urged in the direction to close the valve body. At this time, since the valve body closes the nozzle hole, fuel is not injected from the nozzle hole.

  When the solenoid valve 26 opens and the fuel pressure in the pressure control chamber decreases, the force that the command piston urges the valve body weakens, so the valve body moves in the valve opening direction together with the command piston. Thereby, fuel is injected from a nozzle hole. When the solenoid valve 26 is closed again, the fuel pressure in the pressure control chamber recovers to substantially the same pressure as the fuel pressure in the common rail 21, so that the command piston urges the valve body in the valve closing direction. Thereby, the fuel injection from the nozzle hole stops.

  The injector 23 is connected to a return pipe 36 for returning the fuel discharged from the pressure control chamber to the fuel tank 30 when the electromagnetic valve 26 is opened. The supply pump 10 is also connected to a return pipe 37 for returning surplus fuel that has not been sent to the common rail 21 to the fuel tank 30. These return pipes 36 and 37 merge with the return pipe 35 connected to the pressure limiter 22 described above.

  The control device 40 calculates the injection timing, the injection amount, the injection rate, and the fuel pressure in the common rail 21 that are optimal for engine operation based on signals from various sensors that detect the operating state of the engine, and based on the calculated results. The engine control unit (hereinafter referred to as ECU) that generates a control signal for controlling the electromagnetic valve 26 of the supply pump 10 and the injector 23, and the electromagnetic signal corresponding to the control signal generated by the ECU to the electromagnetic valve 26 of the injector 23 A drive unit (hereinafter referred to as EDU) that generates a high voltage for driving the valve 26 at a high speed is provided.

  The ECU is configured to include functions such as a central processing unit (CPU) that performs control processing and arithmetic processing, a storage device (memory such as ROM and RAM) that stores various programs and control data, an input circuit, and an output circuit. A microcomputer having a known structure and a drive circuit connected to the output circuit, generating an electrical signal corresponding to the generated control signal for controlling the supply pump 10, and sending the electrical signal to the supply pump 10 are provided. .

  The input circuit of the ECU includes a cam position sensor that detects the cam angle of the cam shaft, a crank position sensor that detects the crank angle of the crankshaft of the engine, an air flow meter that detects the air flow rate sucked into the engine, Intake air temperature sensor that detects the temperature of the air to be taken, intake air pressure sensor that detects the pressure of the air sucked into the engine, water temperature sensor that detects the temperature of engine cooling water, accelerator position sensor that detects the opening of the accelerator pedal, common rail Various sensors such as the pressure sensor 38 are electrically connected, and the ECU receives electrical signals from these sensors, and calculates the injection timing, the injection amount, the injection rate, and the fuel pressure in the common rail 21.

  The EDU has a high voltage generator that is connected to an output circuit of the ECU and operates in accordance with a control signal that controls the electromagnetic valve 26 of the injector 23 generated by the ECU. The EDU generates a high voltage with a high voltage generator, and causes a large current to flow through the electromagnetic valve 26 in a short time. The EDU drives the injector 23 at a high speed by applying a high voltage to the electromagnetic valve 26.

  In the present embodiment, an example in which the ECU and the EDU are mounted in one control device 40 is shown, but the ECU and the EDU may be mounted separately.

  The overall configuration of the common rail fuel injection system has been described with reference to FIG. Next, the fuel system in the supply pump 10 will be described with reference to FIG.

  As shown in FIG. 2, the supply pump 10 includes a feed pump 12, a high-pressure pump 15, a flow rate control valve 50 (hereinafter referred to as an intake metering valve), and the like. These elements 12, 15, 50 are integrated in one pump housing.

  The feed pump 12 sucks up the fuel in the fuel tank 30 and discharges the fuel toward the high pressure pump 15 at a predetermined pressure. This feed pump 12 is a trochoid pump. The feed pump 12 is provided on the outer peripheral side of the inner rotor 13 having a plurality of external teeth protruding toward the outer peripheral side, and is engaged with the outer teeth on the inner peripheral side and between the outer teeth. The outer rotor 14 has a plurality of internal teeth that form a volume chamber.

  When the feed pump 12 is driven by the pump drive shaft 11, the inner rotor 13 and the outer rotor 14 are rotationally driven, and the volume of the volume chamber described above is increased or decreased. Using the increase / decrease of the volume chamber, the fuel is sucked from the suction portion, and the fuel is sent from the discharge portion toward the pressurizing chamber 16 of the high-pressure pump 15.

  The feed pump 12 is provided with a regulating valve 90 that stabilizes the fuel pressure sent to the pressurizing chamber 16. With this regulating valve 90, the pulsation of the fuel sent out from the discharge part of the feed pump 12 can be reduced. In this embodiment, the pressure of the fuel sent out from the feed pump 12 is about 0.7 MPa.

  The high-pressure pump 15 pressurizes the fuel sent from the feed pump 12 and sends the pressurized fuel toward the common rail 21. The high-pressure pump 15 is a cylindrical eccentric cam 17 that is eccentrically attached to the rotation shaft of the pump drive shaft 11, is slidably supported on the outer peripheral wall of the eccentric cam 17, and follows the rotation of the eccentric cam 17. A cam ring 18 whose outer diameter revolves around the rotation shaft of the drive shaft 11 is a substantially square shape, a plunger 19 that reciprocates following the revolving motion of the cam ring 18, and a plunger 19 that supports the reciprocating motion. It consists of a cylinder 20 or the like.

  In the present embodiment, the supply pump 10 has two plungers 19 with the cam ring 18 interposed therebetween. The plunger 19 is always pressed against the outer peripheral wall of the cam ring 18 by a biasing means (not shown). The two plungers 19 are respectively accommodated in two cylinders 20 formed in the pump housing. One pressurizing chamber 16 is defined by the end of each plunger 19 opposite to the cam ring 18 and the inner peripheral wall of each cylinder 20.

  Connected to each pressurizing chamber 16 is a fuel intake passage 93 that guides the fuel sent from the discharge portion of the feed pump 12 to each pressurizing chamber 16. In addition, a suction valve 91 that prevents the backflow of fuel from the pressurization chamber 16 to the fuel suction passage 93 is provided at a connection portion between each pressurization chamber 16 and the fuel suction passage 93.

  Each pressurizing chamber 16 is connected to a fuel discharge passage 94 connected to the fuel pipe 33. A discharge valve 92 for preventing a back flow from the fuel discharge flow path 94 to the pressurization chamber 16 is provided at a connection portion between each pressurization chamber 16 and the fuel discharge flow path 94.

  When the pump drive shaft 11 rotates and the eccentric cam 17 rotates, the cam ring 18 revolves around the rotation shaft of the pump drive shaft 11. Then, the plunger 19 reciprocates in the cylinder 20 following the revolving motion of the cam ring 18 to change the volume of the pressurizing chamber 16.

  During the intake stroke in which the plunger 19 increases the volume of the pressurizing chamber 16, the fuel pressure in the pressurizing chamber 16 is lower than the fuel pressure in the fuel intake passage 93 and the fuel discharge passage 94. Then, fuel is sucked into the pressurizing chamber 16.

  When the plunger 19 reduces the volume of the pressurizing chamber 16, the fuel pressure in the pressurizing chamber 16 is higher than the fuel pressure in the fuel intake passage 93. Backflow is blocked by the intake valve 91. When the fuel pressure in the pressurizing chamber 16 exceeds a predetermined pressure, the discharge valve 92 is opened, and fuel is discharged from the pressurizing chamber 16 to the fuel discharge passage 94. Thereafter, the fuel discharged to the fuel discharge passage 94 is sent to the common rail 21 through the fuel pipe 33.

  Here, as shown in FIG. 2, an intake metering valve 50 is provided in the middle of the fuel intake passage 93. The intake metering valve 50 is a valve that controls the amount of fuel sucked into the pressurizing chamber 16, and is controlled by an electrical signal from the control device 40. The intake metering valve 50 controls the amount of fuel drawn into the pressurizing chamber 16, whereby the amount of fuel delivered from the high pressure pump 15 to the common rail 21 is controlled.

  In the present embodiment, the fuel pressure in the common rail 21 is controlled by controlling the amount of fuel delivered to the common rail 21. The intake metering valve 50 is configured to be able to control the amount of fuel sucked into the pressurizing chamber 16 in accordance with the current amount of the electric signal sent from the control device 40.

  In this embodiment, the feed pump 12 and the high-pressure pump 15 are incorporated in one pump housing. However, the feed pump 12 and the high-pressure pump 15 may be incorporated in separate pump housings. good. At this time, the intake metering valve 50 may be incorporated in either the pump housing of the feed pump 12 or the pump housing of the high-pressure pump 15.

  The fuel system in the supply pump 10 has been described above with reference to FIG. Next, the structure of the intake metering valve 50 will be described in detail with reference to FIG. FIG. 3 is a cross-sectional view showing the overall structure of the intake metering valve 50. As shown in FIG. 3, the intake metering valve 50 includes a valve unit 51 and an electromagnetic actuator unit 63 that drives the valve unit 51.

  The valve portion 51 is provided in the middle of the fuel intake flow path, and controls the flow rate of fuel passing through a passage formed inside. The electromagnetic actuator unit 63 is an actuator that is attached to the valve unit 51 and that changes the power generated according to the amount of current supplied. The electromagnetic actuator unit 63 changes the passage cross-sectional area in the valve unit 51 with the changed power. The valve unit 51 includes a valve body 52, a diaphragm 61, and the like.

  The valve body 52 supports the diaphragm 61 and includes a valve chamber 54, an inlet-side passage 55 connected to the valve chamber 54, and an outlet-side passage 56 connected to the valve chamber 54. The valve body 52 is attached to the pump housing such that the inlet-side passage 55 communicates with the fuel suction passage 93 on the feed pump 12 side and the outlet-side passage 56 communicates with the fuel suction passage 93 on the pressurizing chamber 16 side. ing.

  The valve body 52 is made of a metal material and formed in a cylindrical shape. The valve body 52 is made of a metal material and is formed in a cylindrical shape, and is installed coaxially with the body portion 53. The outer peripheral edge of the diaphragm 61 is connected to the body portion 53. And a support portion 59 sandwiched between the two.

  An inlet-side passage 55 and a valve chamber 54 are formed in the main body 53 along the axis of the main body 53. The outlet-side passage 56 is formed so as to penetrate the opposing side wall of the main body 53 in a direction perpendicular to the axis of the main body 53. An O-ring 60 that seals a gap with the fuel suction passage 93 is mounted around the inlet-side passage 55 of the main body 53.

  A connecting portion that connects the inlet-side passage 55 and the valve chamber 54 is a conical surface 57 whose inner diameter gradually increases toward the valve chamber 54. A valve seat 58 on which the diaphragm 61 is seated is formed on the conical surface 57.

  The diaphragm 61 is an elastic thin film body that is formed in a disk shape from an elastic material and delimits the valve chamber 54. In the present embodiment, the diaphragm 61 is made of rubber. The diaphragm 61 is installed to face the conical surface 57.

  On the surface of the diaphragm 61 on the valve seat 58 side, an abutting portion 62 that is seated on the valve seat 58 when the diaphragm 61 is elastically deformed and bent toward the valve seat 58 side is formed. The contact part 62 is formed in an annular shape.

  When the diaphragm 61 is displaced in the direction of the valve seat 58 and the contact portion 62 is seated on the valve seat 58, the communication between the inlet side passage 55 and the outlet side passage 56 is blocked. When the diaphragm 61 bends toward the electromagnetic actuator portion 63 and the contact portion 62 moves away from the valve seat 58, the inlet side passage 55 and the outlet side passage 56 communicate with each other, and fuel flows from the inlet side passage 55 to the outlet side passage 56. Circulate.

  Note that the flow rate of the fuel from the inlet side passage 55 to the outlet side passage 56 changes according to the distance between the contact portion 62 and the valve seat 58. In a state where the contact portion 62 of the diaphragm 61 is seated on the valve seat 58, a restoring force is generated in the diaphragm 61 in a direction away from the valve seat 58, that is, in a direction toward the electromagnetic actuator portion 63 side.

  The electromagnetic actuator unit 63 includes a coil 64, a stator 65, a housing 78, an armature 79, a rod 80, and the like.

  The coil 64 is formed by winding a conductive electric wire around a resin bobbin formed in a cylindrical shape. The coil 64 is provided with a terminal 83 for supplying current to the electric wire. The coil 64 generates a magnetic flux corresponding to the amount of current supplied to the electric wire of the coil 64 via the terminal 83.

  The stator 65 is formed in a cylindrical shape from a magnetic material such as stainless steel, for example, and a part thereof is installed on the inner peripheral side of the coil 64. A housing portion 66 extending in the direction along the axis is formed inside the stator 65. The accommodating portion 66 accommodates the armature 79 and the rod 80 so as to be capable of reciprocating along the axial direction, and supports the support portion 59 of the valve body 52.

  The stator 65 includes a first stator portion 67 installed on the valve body 52 side and a second stator portion 74 installed on the opposite side of the first stator portion 67 from the valve body 52. The first stator portion 67 is formed in a cylindrical shape, and supports the armature 79 so as to be reciprocally movable in the axial direction on the inner peripheral wall surface and supports the support portion 59 of the valve body 52. A through hole 68 communicating with the outlet side passage 56 of the valve body 52 is formed at the end of the first stator 67 on the valve body 52 side.

  A caulking portion 69 is formed at the end of the first stator portion 67 on the valve body 52 side. After a part of the valve body 52 is inserted into the first stator portion 67, the caulking portion 69 and the main body portion 53 The valve body 52 is assembled to the first stator portion 67 by caulking the step portion.

  Further, a flange portion 70 protruding in the radial direction is formed at the center portion of the first stator portion 67. A fastening hole 71 is formed in the flange portion 70 and is fastened to the pump housing by inserting fastening means such as a bolt (not shown).

  The second stator portion 74 is formed in a cylindrical shape, and supports the end portions of the armature 79 and the rod 80 opposite to the valve body 52 so as to be reciprocally movable in the axial direction. The second stator portion 74 has a stopper portion 75 that restricts the movement of the rod 80 when the end portion 82 of the rod 80 opposite to the valve body 52 abuts.

  The first stator portion 67 and the second stator portion 74 are installed such that a predetermined gap is formed between the end portions 72 and 76 of the opposing stator portions 67 and 74. This gap prevents the first stator portion 67 and the second stator portion 74 from being magnetically short-circuited. A tapered surface that is inclined toward the central axis of the first stator portion 67 is formed on the outer periphery of the end portion 72 of the first stator portion 67.

  A housing 78 that is formed in a cylindrical shape from a magnetic material such as stainless steel and that magnetically connects the first stator portion 67 and the second stator portion 74 is installed on the outer peripheral side of the coil 64. The electromagnetic actuator 63 is provided with a resin housing 84 that covers a gap between the housing 78 and the coil 64 and a part of the terminal 83.

  The armature 79 housed in the housing portion 66 of the stator 65 is formed in a cylindrical shape from a magnetic material such as stainless steel, and supports the rod 80 on the inner peripheral side. The outer peripheral wall of the rod 80 closer to the valve body 52 than the armature 79 is supported by the inner peripheral wall of the support portion 59 through a bush 73 made of Teflon (registered trademark) so as to be able to reciprocate. Further, the outer peripheral wall of the rod 80 on the opposite side of the valve body 52 from the armature 79 is supported by the inner peripheral wall of the second stator portion 74 through a Teflon (registered trademark) bush 77 so as to be reciprocally movable. .

  The surface of the end portion 81 on the valve body 52 side of the rod 80 is a spherical surface and can come into contact with the diaphragm 61. The outer diameter of the rod 80 is smaller than the inner diameter of the conical surface 57 on the valve chamber 54 side and larger than the inner diameter of the conical surface 57 on the inlet side passage 55 side.

  The diaphragm 61 is bent in a state where the other end 82 of the rod 80 is in contact with the stopper portion 75 of the second stator portion 74, and urges the rod 80 to the side opposite to the valve body 52. The urging force of the diaphragm 61 increases as the rod 80 is displaced toward the valve body 52 side. As shown in FIG. 3, the urging force is greatest when the contact portion 62 of the diaphragm 61 is in contact with the valve seat 58. As shown in FIG. 3, when the contact portion 62 is in contact with the valve seat 58, the support portion 59 and the armature 79 are separated.

  In the electromagnetic actuator unit 63 configured as described above, when a current is supplied to the electric wire of the coil 64 from the control device 40, the coil 64 generates a magnetic flux according to the supplied amount of current. The generated magnetic flux circulates through the first stator portion 67, the housing 78, the second stator portion 74, the armature 79, and the end portion 72 of the first stator portion 67. Each of these elements 67, 78, 74, 79 forms a magnetic circuit. By forming such a magnetic circuit, a magnetic attraction force that attracts the armature 79 to the end portion 72 is generated between the end portion 72 of the first stator portion 67 and the armature 79. This magnetic attractive force is a force corresponding to the amount of current supplied.

  Next, the operation of the intake metering valve 50 will be described.

  In a state where no current is supplied to the coil 64 from the control device 40, the rod 80 is displaced to a position where the end portion 82 abuts against the stopper portion 75 by the urging force of the diaphragm 61. At this time, the contact portion 62 of the diaphragm 61 is separated from the valve seat 58. For this reason, the fuel that has flowed into the valve chamber 54 from the inlet-side passage 55 flows through the outlet-side passage 56 and the through hole 68 to the fuel intake passage 93. The flow rate of the fuel at this time is a flow rate according to the size of the gap between the conical surface 57 and the surface of the diaphragm 61.

  When a current is supplied to the coil 64 from the control device 40, a magnetic circuit is formed by the first stator portion 67, the housing 78, the second stator portion 74, and the armature 79, and the end 72 and the armature of the first stator portion 67 are formed. 79 generates a magnetic attraction force corresponding to the amount of current supplied to the terminal 79.

  For this reason, the rod 80 tends to be displaced to the valve body 52 side together with the armature 79. The rod 80 stops when the magnetic attractive force generated between the two 67 and 79 and the urging force by which the diaphragm 61 urges the rod 80 are balanced. Thereby, the clearance gap between the conical surface 57 and the surface of the diaphragm 61 becomes narrow compared with the state before electricity supply. For this reason, the flow rate of the fuel passing through this gap is reduced.

  When the amount of current supplied to the coil 64 is further increased, the magnetic attractive force is further increased, and the rod 80 is further displaced toward the valve body 52 side. For this reason, the gap between the conical surface 57 and the surface of the diaphragm 61 is further narrowed, and the flow rate passing therethrough is further reduced.

  When the amount of current supplied to the coil 64 exceeds a predetermined amount, the contact portion 62 of the diaphragm 61 is seated on the valve seat 58. At this time, the communication between the inlet-side passage 55 and the outlet-side passage 56 is blocked, and no fuel passes through the intake metering valve 50.

  Next, the features of the intake metering valve 50 of the present embodiment will be described in comparison with the comparative example shown in FIG. FIG. 4 is a cross-sectional view showing the structure of the characteristic part of the intake metering valve 50. FIG. 5 is a cross-sectional view showing a structure corresponding to the characteristic portion shown in FIG. 4 according to a comparative example compared with the suction metering valve 50 of the present embodiment. FIG. 6 shows the amount of displacement of each rod of the suction metering valve 50 according to the present embodiment and the suction metering valve 50a according to the comparative example, and the area (opening area) of the gap formed between the valve seat and the diaphragm. It is the graph which compared these relationships. 5 and 6 show the state when the valve is closed on the left side of the center line and the state when the rod is displaced by a predetermined amount on the right side of the center line.

  As shown in FIG. 4, the surface on which the valve seat 58 is provided is a conical surface 57 in which the inner diameter that is difficult to move from the inlet-side passage 55 toward the valve chamber 54 gradually increases. In the present embodiment, the communication between the inlet side passage 55 and the outlet side passage 56 is blocked by elastically deforming the diaphragm 61 with the rod 80 and seating the contact portion 62 of the diaphragm 61 on the valve seat 58. . Further, by adjusting the amount of current supplied to the coil 64 to adjust the amount of displacement of the rod 80, the gap between the conical surface 57 and the surface of the diaphragm 61 is adjusted, and the flow rate is controlled.

  On the other hand, the valve seat 58 a of the suction metering valve 50 a according to the comparative example shown in FIG. 5 is formed on a plane that intersects perpendicularly to the axis of the inlet side passage 55. 4 differs from the structure shown in FIG. 4 in that a valve seat 58a is formed on a plane. Since the other parts are the same as those shown in FIG. 4, the same reference numerals as those in this embodiment are used.

  As in FIG. 4, the diaphragm 61a is installed facing the valve seat 58a, and a contact portion 62a seated on the valve seat 58a is formed on the surface of the diaphragm 61a. As in FIG. 4, the rod 80a is configured to be displaced in the axial direction so that the diaphragm 61 is pushed toward the valve body 52, and the contact portion 62a is separated from the seat 58a.

  Also with this structure, by adjusting the amount of current supplied to the coil 64 and adjusting the amount of displacement of the rod 80a, the gap between the plane and the surface of the diaphragm 61a is adjusted, and the flow rate is controlled.

  Differences between the present embodiment and the comparative example will be described in more detail. The conical surfaces that oppose the surfaces of the diaphragms 61 and 61a when the displacements of the rods 80 and 80a from the state in which the contact portions 62 and 62a of the diaphragms 61 and 61a are in contact with the valve seats 58 and 58a are changed. 57 or the change in the gap with the flat surface 57a.

  The diameter of the inlet side passage 55 of the intake metering valves 50 and 50a shown in FIGS. 4 and 5 is D1 (mm), and the angle of the conical surface 57 of the intake metering valve 50 shown in FIG. 4 is α (°) and When the diameter of the valve seat 58 is D2 (mm), the displacement of the rods 80 and 80a from the seating state is H (mm), and the valve seats 58 and 58a and the diaphragms 61 and 61a Compare the gaps that are formed.

  In the case of the valve seat 58a configured as shown in FIG. 5, the cross-sectional area (opening area) of the gap through which the fuel formed between the valve seat 58a and the diaphragm 61a flows is a cylinder with the inlet-side passage 55 as the bottom surface. It is almost the same as the area of the side. When the displacement amount of the rod 80a is H (mm), the area of the side surface of the cylinder with the height H (mm) with the circle having the diameter D1 (mm) as the bottom surface is the opening area.

  On the other hand, in the case of the valve seat 58 having a configuration as shown in FIG. 4, the sectional area (opening area) of the gap through which the fuel formed between the valve seat 58 and the diaphragm 61 flows is the bottom surface of the valve seat 58. The area of a part of the side surface of the cone having an apex angle of 180−α (°) is substantially the same. When the displacement amount of the rod 80 is H (mm), a circle having a diameter D2 (mm) is used as the bottom surface, and the side of the side of the height H (mm) portion from the bottom surface of the cone whose apex angle is 180-α (°). The area is the opening area.

  As described above, when the rods 80 and 80a of the intake metering valves 50 and 50a shown in FIGS. 4 and 5 are displaced from the seating state, the opening area with respect to the unit displacement of the rods 80 and 80a as shown in FIG. The amount of change is different.

  According to FIG. 6, the change amount of the opening area with respect to the unit displacement amount of the rod 80 of the suction metering valve 50 according to the present embodiment shown in FIG. 4 is smaller than that in the comparative example shown in FIG. The opening area changes gently relative to the suction metering valve 50a according to the comparative example of FIG. Since the change amount of the opening area is relatively small, the change amount of the flow rate to be controlled is also small. Therefore, the controllability of the flow rate is better when the valve seat 58 is provided on the conical surface 57 as in this embodiment than when the valve seat 58a is formed on the flat surface 57a. .

  Further, in this embodiment, the diaphragm 61 is elastically deformed to constantly urge the rod 80 to the side opposite to the valve body 52 side. Therefore, it is necessary to separately install a urging means for urging the rod 80. The structure of the intake metering valve 50 can be simplified. Further, since the number of parts can be reduced, an increase in the price of the intake metering valve 50 can be suppressed.

  Moreover, since the diaphragm 61 is installed in the valve body 52 so as to define the valve chamber 54, it is possible to suppress the intrusion of fuel from the valve chamber 54 to the electromagnetic actuator unit 63. For this reason, even if foreign matter is mixed in the fuel, it is possible to prevent foreign matter from entering between the rod 80 and the bushes 73 and 77 or between the armature 79 and the accommodating portion 66 of the stator 65. Therefore, it is possible to suppress the performance deterioration of the intake metering valve 50.

  Furthermore, in this embodiment, since the diaphragm 61 is made of rubber, the diaphragm 61 can effectively reduce the pulsation even if the fuel flowing through the fuel intake passage 93 is pulsating.

  The outer diameter of the rod 80 is smaller than the inner diameter of the conical surface 57 on the valve chamber 54 side and larger than the inner diameter of the conical surface 57 on the inlet side passage 55 side. For this reason, the contact part 62 of the diaphragm 61 can be reliably seated on the valve seat 58 formed on the conical surface 57. Further, since the end portion 81 of the rod 80 is spherical, the load on the diaphragm 61 can be reduced, and the life of the diaphragm 61 can be extended.

  In this embodiment, the diaphragm 61 corresponds to the “elastic thin film body” described in the claims, the rod 80 corresponds to the “bar member” described in the claims, and the electromagnetic actuator portion 63 corresponds to the patent. This corresponds to “driving means” recited in the claims. Further, the entrance-side passage 55 corresponds to a “specific passage” described in the claims.

(Other embodiments)
The embodiment of the present invention has been described above. The present invention is not construed as being limited to the above-described embodiments, and can be applied to various embodiments without departing from the scope of the invention.

  For example, the connecting portion between the outlet side passage 56 and the valve chamber 54 may be a conical surface 57, and the valve seat 58 may be formed on the conical surface 57. At this time, the diaphragm 61 is provided to face the conical surface 57, and the rod 80 needs to be installed so that the contact portion 62 of the diaphragm 61 can be seated on the valve seat 58.

  In the above embodiment, the displacement amount of the rod 80 is controlled, but the displacement amount of the rod 80 is controlled by a linear solenoid including the coil 64, the stator 65, the housing 78, the armature 79, and the like. Even if the suction metering valve is configured to control the displacement amount of the rod 80 by means of a rotating machine constituted by a rotor and the like and a conversion mechanism for converting the rotary motion of the rotary machine into a linear motion. good.

  10 Supply pump, 11 Pump drive shaft, 12 Feed pump, 15 High pressure pump, 16 Pressurizing chamber, 17 Eccentric cam, 18 Cam ring, 19 Plunger, 20 Cylinder, 21 Common rail, 23 Injector, 30 Fuel tank, 31 Filter, 40 Control Device, 50 Suction metering valve (flow control valve), 51 Valve part, 52 Valve body, 53 Main body part, 54 Valve chamber, 55 Inlet side passage, 56 Outlet side passage, 57 Conical surface, 58 Valve seat, 59 Support part , 61 Diaphragm (elastic thin film), 62 Contact portion, 63 Electromagnetic actuator portion, 64 Coil, 65 Stator, 78 Housing, 79 Armature, 80 Rod (bar member), 81 End portion, 83 Terminal, 84 Resin housing, 91 Suction valve, 92 Discharge valve, 93 Fuel intake flow path, 94 Fuel Izuru road

Claims (5)

A valve body having a valve chamber, an inlet-side passage connected to the valve chamber, and an outlet-side passage connected to the valve chamber, the specific passage of either the inlet-side passage or the outlet-side passage and the The wall of the connecting portion with the valve chamber is a conical surface, and the valve body has a valve seat formed on the conical surface;
When the contact portion is made of an elastic material and is opposed to the valve seat, has a contact portion that sits on the valve seat on the surface of the valve seat, and elastically deforms, the contact portion is seated on the valve seat. When the flow of fluid from the inlet side passage to the outlet side passage is blocked and the contact portion is separated from the valve seat by the restoring force of the elastic material, the fluid from the inlet side passage to the outlet side passage is removed. An elastic thin film that permits distribution;
The elastic thin film body is installed on a side opposite to the valve seat, and the elastic thin film body moves along a direction in which the elastic thin film body is seated on the valve seat and a direction in which the elastic thin film body is separated from the valve seat. A rod member for separating and seating the contact portion on the valve seat;
Position of the rod member between the state in which the elastic thin film body is opposite to the valve seat and the contact portion is seated on the valve seat until the maximum displacement of the rod member in the separating direction A flow control valve comprising: drive means for controlling the position to a predetermined position.   The flow control valve according to claim 1, wherein the elastic thin film body is installed so as to define the valve chamber.   The flow rate control valve according to claim 1 or 2, wherein the elastic thin film body is made of rubber.   4. The outer diameter of the rod member is smaller than an inner diameter of the conical surface on the valve chamber side and larger than an inner diameter of the conical surface on the specific passage side. 5. The flow control valve described in 1.   The flow rate control valve according to any one of claims 1 to 4, wherein an end portion of the rod member in contact with the elastic thin film body is a spherical surface.

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