JP2006299855A - Fluid control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain seat contact pressure necessary for sealing a communication hole 23 with the minimum load while keeping receiving pressure at the minimum. <P>SOLUTION: Since the communication hole 23 and a ball storage hole 24 are concentrically formed and a valve seat 25 is flattened, receiving pressure which a ball valve 6 receives from high pressure fuel in the communication hole 23 can be reduced. Since contact area of the valve seat 25 adhering on a seal part 27 of the ball valve 6 becomes very small and linear, seat contact pressure necessary for sealing can be obtained with the minimum load. Since a ball guide 26 is formed with the ball storage hole 24 of a valve body 5 as one unit, concentricity of the communication hole 23 and the ball guide 26 is improved. Consequently, the ball valve 6 can be adhered on the valve seat 25 without the ball valve 6 shifting from a center line of the valve seat 25 to outer diameter side in a radial direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fluid control valve such as a fluid pressure control valve or a fluid flow rate control valve, and more particularly to a fluid control valve such as an injector solenoid valve, a pressure reducing adjustment valve, or a fuel pressure adjusting valve incorporated in a fuel injection device for an internal combustion engine. Related to.

[Conventional technology]
In recent years, for example, regulations on exhaust gas purification of diesel engines have become stricter. Along with this, in order to make the exhaust gas exhausted from the engine cleaner, especially in order to reduce diesel particulates typified by black smoke (smoke), the sprayed fuel injected from the injection hole of the injector is used. It is important to atomize to the limit. In order to promote atomization of the atomized fuel, it is effective to increase the fuel injection pressure. As such a fuel injection system for a diesel engine, a common rail fuel that accumulates high pressure fuel discharged from a supply pump in a common rail and injects the high pressure fuel accumulated in the common rail into an engine cylinder via an injector. Injection systems are known.

  This common rail fuel injection system includes an injector solenoid valve that drives the nozzle needle in the valve opening direction by causing the high pressure fuel in the control chamber to overflow to the low pressure side of the fuel system by being driven to open the valve. Pressure reducing valve to reduce the fuel pressure in the engine to the target value, pressure limiter that opens when the fuel pressure in the common rail exceeds the set value, overflow valve that opens when the fuel pressure in the supply pump exceeds the set value, etc. The fluid control valve is used. These fluid control valves have a discharge function that allows high pressure fuel to escape to the low pressure side of the fuel system when necessary, and high pressure from the high pressure chamber to the low pressure chamber so that the high pressure fuel does not overflow to the low pressure side of the fuel system when not necessary. It also has a sealing function for sealing (sealing) an inflow hole (for example, an orifice or the like) through which fuel flows.

  As a fluid control valve that realizes both of the above functions, an electromagnetic pressure regulating valve used in a common rail fuel injection system has been proposed (see, for example, Patent Document 1). This is because when a solenoid coil is energized, a valve member integrated with the armature is sucked to one side in the axial direction, and a sphere formed at the tip of the valve member is formed into a valve body having a tapered valve seat (valve seat). Is pressed against the orifice to seal the high pressure chamber and the low pressure chamber. In addition, by stopping energization of the solenoid coil and reducing the pressing force acting in the direction of pressing the sphere against the valve seat, the valve member receives the pressure received by the valve member in the direction away from the fuel pressure in the orifice from the valve seat. The member is separated from the valve seat to open the orifice so that the high-pressure fuel in the high-pressure chamber is released to the low-pressure chamber. Thereby, the fuel pressure in the high pressure chamber can be reduced.

[Conventional technical problems]
However, in the conventional electromagnetic pressure regulating valve, the seat diameter is determined by the taper angle and the sphere diameter. Therefore, even if the orifice diameter is reduced, the pressure receiving force acting in the direction of separating the sphere from the valve seat can be reduced. There is a problem that you can not. Therefore, in order to reduce the receiving pressure, it is necessary to reduce the sphere diameter or increase the taper angle. When the sphere diameter is reduced, there is a problem that the sphere is difficult to handle and the manufacture becomes difficult. On the other hand, when the taper angle is increased, it becomes difficult to maintain the sphere at the center of the orifice, and there is a problem that the sealing performance is lowered.

  In order to solve this problem, it is necessary to provide a separate member for holding the spherical valve body (ball valve) or to provide a mechanism for holding the ball valve around the armature (for example, Patent Documents). 2 and 3). When a mechanism that holds the ball valve in a separate member with respect to the orifice member as described above is provided, there is a problem that the position shift occurs depending on the accuracy of the coaxiality between the parts. There is a possibility that the inflow hole (for example, an orifice) cannot be sealed. As a method of reducing the load applied to the valve member in the direction of pressing against the valve seat, there is a method of increasing the seat pressure by reducing the contact area between the ball valve and the valve seat. If it is a taper sheet | seat, a valve seat will become linear, However As mentioned above, there exists a problem that it is difficult to reduce a receiving pressure.

On the other hand, a fuel hole is opened at the bottom surface of the enlarged diameter hole whose inner diameter is larger than the diameter of the fuel hole, and a spring is applied to a valve seat provided at an edge portion (opening peripheral edge portion of the fuel hole) of the fuel hole. There has been proposed a pressure valve in which a ball valve is seated by using the urging force to close the fuel hole (see, for example, Patent Document 4). This can increase the seat pressure while minimizing the receiving pressure, but when the seat diameter is very small relative to the ball diameter, the structure in which the ball valve is positioned with a spring is the fuel when the pressure valve is closed. There is a problem that it becomes difficult to hold the ball valve at the center of the edge portion at the mouth of the hole, making it impossible to seal the fuel hole.
JP 2001-132578 A (page 1-4, FIG. 1 to FIG. 3) JP 2002-317726 A (page 1-8, FIG. 2 to FIG. 5) JP 2003-172232 A (page 1-4, FIGS. 1-2) Japanese Patent Laid-Open No. 05-223028 (page 1-4, FIGS. 1 to 4)

  An object of the present invention is to provide a fluid control valve capable of obtaining a seat surface pressure necessary for sealing an inflow hole with a minimum load while suppressing a receiving pressure to a minimum.

  According to the first aspect of the present invention, the load is applied to the opening peripheral portion of the inflow hole from the load applying force rather than the pressure received by the ball valve in the direction away from the opening peripheral portion of the inflow hole from the high pressure fluid in the inflow hole. When the load received by the ball valve in the direction is large, the ball valve is seated on the opening peripheral edge portion of the inflow hole, thereby closing the inflow hole. As a result, even if the load received by the ball valve from the load applying means against the opening peripheral edge of the inflow hole is small, the contact area between the ball valve and the opening peripheral edge of the inflow hole is small. Since the required sheet surface pressure can be increased, the gap between the inflow hole and the recess can be reliably sealed. In addition, the load received by the ball valve in the direction of pressing from the load applying means to the opening peripheral portion of the inflow hole is smaller than the receiving pressure received by the ball valve in the direction away from the opening peripheral portion of the inflow hole from the high-pressure fluid in the inflow hole. Then, the ball valve is separated from the opening peripheral edge of the inflow hole, so that the inflow hole is opened.

  And the inflow hole for making a high pressure fluid flow in into a recessed part is formed coaxially with a recessed part, and the opening peripheral part of an inflow hole is substantially made with respect to the axial direction of a recessed part or an inflow hole. By adopting a vertical flat surface, the opening peripheral edge of the inflow hole (the valve seat of the valve body (valve seat)) becomes a flat sheet, so that the high-pressure fluid in the inflow hole is separated from the opening peripheral edge of the inflow hole. The pressure received by the ball valve can be reduced. In addition, since the contact area of the opening periphery of the inflow hole on which the ball valve is seated becomes smaller and linear, the minimum load (the load that the ball valve receives in the direction of pressing from the load applying means to the opening periphery of the inflow hole) ), The sheet surface pressure required for closing (sealing) the inflow hole can be obtained.

  According to the second aspect of the present invention, the bottom surface of the recess is used as a restriction surface for restricting the movement range of the ball valve in the axial direction, so that when the ball valve is seated on the opening peripheral edge of the inflow hole, Further movement of the valve in the axial direction (valve closing direction) is restricted. According to the third aspect of the present invention, the ball body (valve guide) for guiding the ball valve in the direction of the central axis of the recess or the inflow hole is integrally formed on the valve body, whereby the inflow hole and the ball are formed. Since the coaxiality with the guide is improved, the ball valve can be easily maintained on the central axis of the inflow hole or the central axis of the recess. Accordingly, the ball valve is seated on the central axis of the opening peripheral edge of the inflow hole without being displaced from the opening peripheral edge of the inflow hole, so that the gap between the inflow hole and the recess is surely sealed. be able to.

  According to the fourth aspect of the present invention, when the wall surface of the ball guide is used as a restricting surface for restricting the radial movement range of the ball valve, the ball valve is separated from the opening peripheral edge of the inflow hole. Further, the movement of the ball valve toward the outer diameter side in the radial direction is restricted. According to the fifth aspect of the present invention, since the clearance is formed between the ball guide of the valve body and the ball valve, the inflow hole is separated when the ball valve is separated from the opening peripheral edge of the inflow hole. The high-pressure fluid inside is guided through the clearance, that is, through the periphery of the ball valve to the downstream side in the fluid flow direction.

  According to the sixth aspect of the present invention, when the flow rate of the high-pressure fluid passing through the clearance between the ball guide and the ball valve increases as the ratio of the hole diameter of the inflow hole to the ball valve increases, Since the resistance increases, the flow rate of the high-pressure fluid is difficult to increase, and the pressure received from the high-pressure fluid in the inflow hole when the ball valve is separated from the opening peripheral edge of the inflow hole is increased. Therefore, by providing a fluid passage on the outer diameter side in the radial direction with respect to the ball guide of the valve body, the high-pressure fluid that has flowed into the recess through the inflow hole flows smoothly downstream in the fluid flow direction through the fluid passage. become. As a result, even when the flow rate of the high-pressure fluid flowing from the inflow hole into the recess increases, it is possible to obtain the seat surface pressure necessary for closing the inflow hole with the minimum load while suppressing the pressure receiving pressure to the minimum. .

  According to the seventh aspect of the present invention, when the coil is energized, a magnetic attractive force that attracts the load applying member in the direction separating the ball valve from the ball valve is generated in the coil. Then, for example, the load applying member is separated from the ball valve against the urging force of ball urging means (valve urging means) such as a spring, a leaf spring, a rubber-based elastic body, a wave washer, and an air cushion. Then, compared to the pressure received by the ball valve in the direction away from the peripheral edge of the inflow hole from the high-pressure fluid in the inflow hole, the load received by the ball valve in the direction of pressing from the load applying member to the peripheral edge of the inflow hole is smaller. Weakened. As a result, the ball valve is separated from the opening peripheral edge of the inflow hole by the fluid pressure of the high pressure fluid in the inflow hole, so that the high pressure fluid in the inflow hole flows into the recess from the inflow hole and passes around the ball valve. As a result, the fluid flows out downstream in the fluid flow direction.

  Further, when the energization to the coil is stopped, the ball valve is pressed against the opening peripheral portion of the inflow hole through the load applying member by the urging force of the ball urging means. And the space between the inflow hole and the recess is sealed. This makes it possible to minimize the force for bringing the ball valve into close contact (sealing) with the peripheral edge of the opening of the inflow hole, so that the urging force of the ball urging means can be set to a low value. Thereby, since the magnetic attraction force of the coil for opening the ball valve using the fluid pressure can be reduced, the number of turns of the coil and the magnetic path area can be reduced. Therefore, it is possible to reduce the size and cost of the electromagnetic drive unit constituted by the load applying member, the coil and the like.

  According to the eighth aspect of the present invention, when the coil is energized, a magnetic attraction force that attracts the load applying member in the direction of pressing the ball valve is generated in the coil. Since the ball valve is pressed against the opening peripheral edge of the inflow hole through the load applying member by the magnetic attractive force of the coil, the ball valve is in close contact with the opening peripheral edge of the inflow hole and the inflow hole and the recess are The gap is sealed. This makes it possible to minimize the force for bringing the ball valve into close contact with the opening peripheral edge of the inflow hole, thereby reducing the number of turns of the coil and the magnetic path area. Therefore, it is possible to reduce the size and cost of the electromagnetic drive unit constituted by the load applying member, the coil and the like.

  According to the ninth aspect of the present invention, a spring, a leaf spring, a rubber-based elastic body, a wave washer, which directly contacts the ball valve and applies a load to the opening peripheral portion of the inflow hole. By providing ball urging means (valve urging means) such as an air cushion, it is possible to minimize the load received by the ball valve in the direction of pressing from the ball urging means to the peripheral edge of the opening of the inflow hole. Therefore, the ball urging means can be reduced, and the fluid control valve can be reduced in size and cost.

  According to the invention of claim 10, a spring, a leaf spring, a rubber-based elastic body, a wave washer, which directly contacts the ball valve and applies a load to the opening peripheral portion of the inflow hole. By providing ball urging means (valve urging means) such as an air cushion, it is possible to minimize the load received by the ball valve in the direction of pressing from the ball urging means to the peripheral edge of the opening of the inflow hole. Therefore, the ball urging means can be reduced, and the fluid control valve can be reduced in size and cost. Furthermore, by arbitrarily changing the axial thickness of the urging force adjusting member (for example, plate), the load received by the ball valve in the direction of pressing from the ball urging means to the peripheral edge of the opening of the inflow hole is arbitrarily adjusted. be able to.

  According to the eleventh aspect of the present invention, a spring, a leaf spring, which applies a load to the ball valve in a direction to contact the ball valve indirectly and press against the peripheral edge of the opening of the inflow hole via the biasing force transmitting member. By providing ball urging means (valve urging means) such as rubber-based elastic bodies, wave washers, air cushions, etc., even if the ball valve has a small diameter (spherical diameter), it is easy to handle the ball valve. Thus, it becomes easy to press the ball valve against the opening peripheral edge of the inflow hole using the ball urging means.

  The best mode for carrying out the present invention is to provide a sheet surface pressure necessary for sealing the inflow hole with a minimum load while keeping the pressure receiving pressure to a minimum. An inflow hole for allowing a high-pressure fluid to flow in is formed coaxially with the recess, and the opening peripheral edge of the inflow hole is formed as a flat surface perpendicular to the axial direction of the recess or the inflow hole.

[Configuration of Example 1]
FIG. 1 and FIG. 2 show Example 1 of the present invention, FIG. 1 is a view showing a peripheral structure of a ball valve, and FIG. 2 is a view showing an overall structure of a normally closed pressure reducing regulating valve. is there.

  A fuel injection device for an internal combustion engine according to the present embodiment is a common rail fuel injection system (accumulated pressure) known as a fuel injection system for an internal combustion engine (hereinafter referred to as an engine) such as a multi-cylinder diesel engine mounted on a vehicle such as an automobile. The high-pressure fuel accumulated in the common rail 11 is injected and supplied into the combustion chamber of each cylinder of the engine. This common rail fuel injection system includes a common rail 11 that accumulates high-pressure fuel corresponding to the fuel injection pressure, a supply pump (fuel supply pump: not shown) that pumps high-pressure fuel into the common rail 11, and an engine A plurality of injectors (fuel injection valves: not shown) for injecting fuel into the combustion chambers of the cylinders, and an engine control unit (hereinafter referred to as ECU) that electronically controls the electromagnetic suction metering valves of the supply pump and the electromagnetic valves of the injectors : Not shown).

  The high-pressure fuel accumulated in the common rail 11 is supplied from a supply pump. The fuel pressure in the common rail 11 (common rail pressure) is measured by a common rail pressure sensor (not shown) as fuel pressure detecting means. The common rail 11 is connected to a leak pipe 13 for returning fuel from the common rail 11 to the low pressure side (fuel tank) of the fuel system. The fuel return path 14 of the leak pipe 13 is opened and closed by electronic control between the common rail 11 and the leak pipe 13 by a pressure reduction valve drive signal applied from the ECU via a pressure reduction valve drive circuit (not shown). A normally closed type (normally closed type) decompression regulating valve 1 that can be controlled is mounted.

  The injector is mounted corresponding to each cylinder of the engine, and is a fuel injection nozzle composed of a nozzle body and a nozzle needle, an electromagnetic valve that drives the nozzle needle in the valve opening direction, and biases the nozzle needle in the valve closing direction. It is composed of a spring. The fuel injection from the injector into the combustion chamber of each cylinder of the engine is performed by energizing and stopping energization of the solenoid valve that controls increase / decrease of the fuel pressure in the control chamber that controls the back pressure of the command piston provided coaxially with the nozzle needle. Electronically controlled. This solenoid valve is electronically controlled by an injector drive signal applied from the ECU via an injector drive circuit (not shown), thereby controlling the fuel injection amount and fuel injection timing of the injector. That is, since the high-pressure fuel supplied from the common rail 11 into the control chamber overflows to the low-pressure side (fuel tank) of the fuel system through the orifice (inflow hole) while the solenoid valve of the injector is driven to open, the nozzle The needle and the command piston are lifted, and high-pressure fuel is injected and supplied into the combustion chamber of each cylinder of the engine.

  The supply pump is a high-pressure supply pump that is driven to rotate by the crankshaft of the engine, pressurizes the sucked fuel, and discharges the high-pressure fuel from the discharge port to the common rail 11. In the fuel supply path from the fuel tank to the pressurization chamber of the supply pump, an electromagnetic suction metering for controlling the fuel discharge amount to the common rail 11 by adjusting the fuel suction amount sucked into the pressurization chamber. A valve is installed. This electromagnetic suction metering valve changes the common rail pressure by being electronically controlled by a pump drive signal applied from the ECU via a pump drive circuit (not shown).

  The pressure reducing adjustment valve 1 of the present embodiment corresponds to a fluid control valve (fluid pressure control valve) of the present invention. A cylindrical adapter 3 that is liquid-tightly fixed to a common rail 11 is fixed in the adapter 3. A valve body 5 that is held and fixed, and a ball valve (spherical valve) that is a spherical body that controls opening and closing of the fuel return path 14 of the leak pipe 13 by being seated and separated from the valve seat (valve seat) of the valve body 5 Body) 6 and load applying means for applying a load to the ball valve 6 in a direction in which the ball valve 6 is pressed against the valve seat of the valve body 5. The valve body 5 and the ball valve 6 constitute a ball valve (ball valve device).

  As shown in FIG. 2, the adapter 3 has a reduced-diameter portion that forms a high-pressure chamber (upstream in the fluid flow direction from the inflow hole) 15 inside, and a low-pressure chamber (downstream in the fluid flow direction from the recess) inside. Side) 16 is a cylindrical metal part having an enlarged-diameter portion, and the high-pressure chamber 15 and the low-pressure chamber 16 are liquid-tightly defined by a valve body 5 press-fitted into the enlarged-diameter portion. . An outer peripheral screw portion (male screw portion) that is screwed into an inner peripheral screw portion (female screw portion) of the cylindrical portion 17 of the common rail 11 is formed on the outer periphery of the reduced diameter portion.

  The adapter 3 has a high pressure in which the contact surface of the tip flat portion of the reduced diameter portion and the contact surface of the step portion 18 of the common rail 11 are in close contact with each other by the axial force of the decompression regulating valve 1 generated by screw tightening. It is sealed (metal seal). In the high pressure chamber 15, a fuel filter 19 that captures foreign matters in the fuel is installed. The high pressure chamber 15 communicates with the pressure accumulation chamber 12 of the common rail 11. Further, the cylinder 20 is screwed to the inner peripheral portion of the enlarged diameter portion of the adapter 3. On the outer periphery of the cylinder 20, an outer peripheral screw portion (male screw portion) that is screwed into an inner peripheral screw portion (female screw portion) of the enlarged diameter portion of the adapter 3 is formed. A fuel flow path 21 that forms the low pressure chamber 16 is formed inside the cylinder 20.

  The valve body 5 is an annular plate-shaped metal part having a front end flat portion that is in close contact with the close contact surface of the stepped portion 22 of the adapter 3 and a rear end flat portion that is in close contact with the close contact surface of the front end flat portion of the cylinder described later. In addition, a communication hole (reduced diameter hole) 23 communicating with the high pressure chamber 15 and a concave ball housing hole (ball pocket, expanded diameter hole) 24 having a bottom surface are formed. The communication hole 23 is a circular inflow hole for allowing the high pressure fuel in the pressure accumulating chamber 12 and the high pressure fuel in the high pressure chamber 15 to flow into the ball accommodation hole 24, and has a diameter smaller than the inner diameter of the ball accommodation hole 24. Has been. In addition, the communication hole 23 opens at the flat end portion of the valve body 5 and opens at the bottom surface of the ball receiving hole 24 and is formed substantially coaxially with the ball receiving hole 24. The open end of the communication hole 23 opened at the front end flat portion of the valve body 5 is a truncated cone-shaped tapered surface that gradually increases in diameter toward the high-pressure chamber 15. Further, the communication hole 23 may be an orifice (fixed throttle) having a channel cross-sectional area that is extremely smaller than the channel cross-sectional area of the high-pressure chamber 15 or the ball housing hole 24.

  A cylindrical space for accommodating the ball valve 6 so as to be movable in the axial direction is formed in the ball receiving hole 24. Further, on the bottom surface of the ball receiving hole 24, the opening peripheral edge of the communication hole 23 (the opening peripheral edge of the inflow hole, the valve seat of the valve body: hereinafter referred to as valve seat), which is in close contact with the ball valve 6 when the pressure reducing regulator 1 is closed. 25) is provided. Further, the bottom surface of the ball receiving hole 24 including the valve seat 25 is used as a restricting surface for restricting the movement range of the ball valve 6 in the axial direction. As a result, when the ball valve 6 comes into close contact with the valve seat 25, the further movement of the ball valve 6 in the axial direction (the valve closing direction) is restricted.

  The bottom surface of the ball receiving hole 24 including the valve seat 25 is a flat surface perpendicular to the axial direction of the communication hole 23 and the ball receiving hole 24. Further, the inner wall surface of the ball accommodation hole 24 functions as a ball guide 26 that guides the ball valve 6 in the direction of the central axis of the communication hole 23 and the ball accommodation hole 24. Further, the inner wall surface of the ball guide 26 is used as a regulating surface that regulates the radial movement range of the ball valve 6. Thereby, when the ball valve 6 is separated from the valve seat 25, the further movement of the ball valve 6 toward the outer diameter side in the radial direction is restricted.

  The ball valve 6 is a metal body such as steel having a spherical surface. The ball valve 6 linearly moves in the axial direction in the ball receiving hole 24 of the valve body 5, and has an annular seal portion 27 that is in close contact with the valve seat 25. A pressure receiving portion (pressure receiving portion) 28 that receives the fuel pressure in the hole 23 and a load receiving portion 29 that receives a load from the load applying means are provided. The ball valve 6 is housed in a cylindrical space of the ball housing hole 24 so as to be reciprocally movable in the axial direction. The ball valve 6 is seated and separated from a valve seat provided integrally with the valve seat 25 to communicate with each other. The hole 23 is closed and opened.

  As a result, when the seal portion 27 of the ball valve 6 is in close contact with the valve seat 25, the high-pressure fuel on the high-pressure chamber side does not overflow into the low-pressure side (fuel tank) of the fuel system and the ball is accommodated in the communication hole 23. The communication state with the hole 24 is blocked (seal function). Further, when the ball valve 6 is separated (lifted) from the valve seat, the communication hole 23 and the ball receiving hole 24 are provided so that the high pressure fuel on the high pressure chamber side can overflow to the low pressure side (fuel tank) of the fuel system. Are in communication with each other (discharge function). Further, high-pressure fuel can flow from the high-pressure chamber 15 toward the low-pressure chamber 16 between the inner peripheral surface of the ball guide 26 of the valve body 5 and the radial side surface orthogonal to the axial direction of the ball valve 6. A clearance 30 is formed. Note that the diameter (spherical diameter) of the ball valve 6 is extremely larger than the inner diameter (hole diameter) of the communication hole 23 and smaller than the inner diameter of the ball receiving hole 24 by a clearance of 30 minutes.

Next, the configuration of the load applying means of this embodiment will be briefly described with reference to FIG.
The load applying means of the present embodiment is constituted by an electromagnetic drive unit (solenoid unit) 7 that generates a magnetic attractive force (magnetomotive force) by supplying an exciting current. The electromagnetic drive unit 7 applies a load to the ball valve 6 in a direction in which the solenoid coil 31 that generates magnetic flux when energized, the stator core 32 excited by the solenoid coil 31, and the ball valve 6 are pressed against the valve seat 25. A coil spring (ball urging means) 34 that urges the armature 33 toward one side in the axial direction (the valve closing direction of the ball valve 6 (side where the communication hole 23 is closed)), And a housing 35 or the like that is screwed to the outer peripheral portion of the expanded diameter portion of the adapter 3.

  The solenoid coil 31 is a coil in which a conductive wire with an insulating coating is wound around the outer periphery of a coil bobbin (not shown) housed in the coil housing portion 40 of the stator core 32 a plurality of times. The solenoid coil 31 has a coil portion wound around the outer periphery of the coil bobbin and a pair of terminal lead wires taken out from the coil portion. The pair of terminal lead wires are electrically connected to a terminal (external connection terminal) 41. The terminal 41 is electrically connected to an ECU and a power source (battery) via a pressure reducing valve drive circuit.

  When an exciting current is supplied to the solenoid coil 31 of this embodiment, the armature 33 is moved in the stroke direction (the other side in the axial direction) against the spring force (spring constant) of the coil spring 34, that is, the armature 33 is moved to the ball valve. A magnetic attraction force that attracts in a direction away from 6 is generated. As a result, the load applied to the ball valve 6 in the direction in which the ball valve 6 is pressed against the valve seat 25 from the armature 33 is weakened, so that the ball valve 6 is pushed up by the fuel pressure of the high-pressure fuel and is more easily lifted than the valve seat 25. . That is, the valve opening response is improved.

  The stator core 32 is a magnetic body formed of, for example, a soft magnetic material, and has a predetermined gap between the solenoid coil 31 and the cylindrical coil storage portion 40 that stores the coil bobbin and the stator side end surface of the armature 33. The tip pole face 42 is disposed opposite to each other. A cylindrical stopper (not shown) is mounted inside the stator core 32. This stopper functions as a restricting portion that locks the armature 33 and restricts further movement of the armature 33 when the armature 33 is fully lifted.

  The armature 33 is a magnetic body made of, for example, a soft magnetic material. The armature 33 forms a magnetic circuit with the solenoid coil 31 and the stator core 32 and is excited by the magnetomotive force of the solenoid coil 31. It is a moving body that is attracted to the magnetic pole surface 42 and moves to the other side in the axial direction (the valve opening direction of the ball valve 6 (the side that opens the communication hole 23)). The armature 33 can be displaced in the axial direction within a predetermined range of movement, and has an annular flange portion (annular portion) 43 disposed opposite to the tip magnetic pole surface 42 of the stator core 32, and the axial direction from the flange portion 43. It has a shaft portion (axial portion) 44 that protrudes on the opposite side (one side) to the stator side and is movably accommodated in the axial hole of the cylinder 20.

  The flange portion 43 is accommodated in an armature chamber 46 that forms the most downstream side in the fuel flow direction in the low pressure chamber 16. The armature chamber 46 includes an inner wall surface at the open end of the enlarged diameter portion of the adapter 3, an illustrated upper end surface of the cylinder 20 (stator side end surface opposite to the body side end surface in the axial direction), and a tip magnetic pole surface 42 of the stator core 32. Is formed between. The shaft portion 44 has a lower end surface (circular flat surface) in direct contact with the load receiving portion 29 of the ball valve 6 and presses the ball valve 6 against the valve seat 25 in a direction to press the ball valve 6. A load is applied to 29. That is, the armature 33 has a function of pressing the ball valve 6 in the direction of closing the communication hole 23 by the spring force (biasing force, spring constant) of the coil spring 34.

  The coil spring 34 is formed of a metal material such as carbon steel having excellent elasticity, and is accommodated in the axial hole 45 of the stopper, and an equal pitch coil (or an unequal pitch coil) is used. One end of the coil spring 34 in the axial direction is locked to the stator side end surface of the flange portion 43 of the armature 33, and the other end in the axial direction is locked to the top wall surface of the housing 35.

  On the inner periphery of the housing 35, an inner peripheral screw portion (female screw portion) that is screwed into an outer peripheral screw portion (male screw portion) of the enlarged diameter portion of the adapter 3 is formed. In addition, the housing 35 is formed with a leak port 47 communicating with the fuel return path 14 of the leak pipe 13 and a cylindrical connector portion 48 that holds the terminal 41. The internal space of the axial hole 45 of the stopper functions as a fuel passage that connects the low pressure chamber 16 including the fuel flow path 21 and the armature chamber 46 and the leak port 47. The stopper is preferably formed of a non-magnetic material in order to prevent a poor response due to residual magnetism after the exciting current flowing through the solenoid coil 31 is cut off.

[Operation of Example 1]
Next, the operation of the pressure reducing control valve 1 of this embodiment will be briefly described with reference to FIGS.

  When it is necessary to overflow the high pressure fuel in the pressure accumulation chamber 12 to the low pressure side of the fuel system for the purpose of lowering the fuel pressure in the pressure accumulation chamber 12 of the common rail 11, a solenoid coil is connected from the ECU via the pressure reducing valve drive circuit. An exciting current is supplied to 31. When an exciting current flows through the solenoid coil 31, a magnetic flux is generated around the solenoid coil 31. The magnetic flux generated around the solenoid coil 31 passes through the stator core 32 and the armature 33. As a result, the stator core 32 and the armature 33 are excited (magnetized), so that an attractive force is exerted on the armature 33 in the direction closer to the other side in the axial direction, that is, the tip magnetic pole surface 42 of the stator core 32. Accordingly, the armature 33 starts to move in a direction approaching the tip magnetic pole surface 42 of the stator core 32 from a state in which the ball valve 6 is pressed against the valve seat 25 by the spring force of the coil spring 34.

  When the armature 33 moves in a direction approaching the tip magnetic pole surface 42 of the stator core 32, the pressure received by the pressure receiving portion 28 of the ball valve 6 in a direction away from the high pressure fuel in the communication hole 23 of the valve body 5 from the valve seat 25. In comparison, the load applied to the load receiving portion 29 of the ball valve 6 in the direction of pressing from the armature 33 to the valve seat 25 is weakened, and the load received by the ball valve 6 in the direction of pressing from the armature 33 to the valve seat 25 (coil spring). 34 spring force) is lost. At this time, in the high pressure chamber 15 of the adapter 3 upstream of the pressure receiving portion 28 of the ball valve 6 in the fuel flow direction and in the communication hole 23 of the valve body 5, the fuel pressure in the pressure accumulation chamber 12 of the common rail 11 is equal. High-pressure fuel is introduced, and the inside of the ball housing hole 24 of the valve body 5 on the downstream side of the pressure receiving portion 28 of the ball valve 6 in the fuel flow direction is in the low-pressure chamber 16 (the fuel flow path 21 and the armature chamber 46 of the adapter 3. ), And communicates with the low pressure side (fuel tank) of the fuel system through the axial hole 45 and the leak port 47 of the stopper.

  Therefore, the fuel pressure in the upstream side of the ball valve 6 in the fuel flow direction is much higher than the pressure receiving portion 28 in the ball valve 6 than the downstream side in the fuel flow direction, so the axial direction of the armature 33 The ball valve 6 is pushed up in the lift direction by the fuel pressure as the valve moves to the other side, so that the seal portion 27 of the ball valve 6 is separated from the valve seat 25. As a result, the communication hole 23 provided in the valve body 5 is opened, so that the high-pressure fuel in the pressure accumulating chamber 12 of the common rail 11 passes through the high-pressure chamber 15 of the adapter 3 → the communication hole 23 of the valve body 5. It flows into the ball receiving hole 24 of the valve body 5 from the opening end.

  The high-pressure fuel that has flowed into the ball housing hole 24 is formed between the inner peripheral surface of the ball guide 26 of the valve body 5 and the radial side surface orthogonal to the axial direction of the ball valve 6. Flows through the circumference of the ball valve 6 to the low pressure chamber 16 of the adapter 3. At this time, the area of the flow path formed in the clearance 30 between the inner peripheral surface of the ball guide 26 and the side surface of the ball valve 6 increases substantially in proportion to the ratio of the hole diameter of the communication hole 23 to the diameter of the ball valve 6. The high-pressure fuel can flow smoothly to the low-pressure chamber. The high pressure fuel that has flowed into the low pressure chamber 16 passes through the fuel flow path 21 → the armature chamber 46 → the axial hole 45 of the stopper → the leak port 47 → the fuel return path 14 of the leak pipe 13, and the low pressure side of the fuel system. Overflows into (fuel tank). As a result, the fuel pressure in the accumulator chamber 12 of the common rail 11 quickly decreases to a target value (target common rail pressure) set corresponding to the operating state of the engine, and is supplied from the injector into the combustion chamber of each cylinder of the engine. The fuel injection pressure is optimized by optimizing the fuel injection pressure.

  Further, when the supply of the excitation current to the solenoid coil 31 is stopped, the stator core 32 and the armature 33 are demagnetized, so that the armature 33 is one side in the axial direction by the spring force of the coil spring 34, that is, the tip magnetic pole surface 42 of the stator core 32. Move further away. As a result, one end surface (tip surface) in the axial direction of the shaft portion 44 of the armature 33 abuts on the load receiving portion 29 of the ball valve 6 and presses the seal portion 27 of the ball valve 6 against the valve seat 25. At this time, since the seal portion 27 of the ball valve 6 is in close contact with the valve seat 25 without being displaced, it is possible to prevent leakage of high-pressure fuel from the communication hole side to the ball housing hole side.

  Here, since the communication hole 23 and the ball receiving hole 24 or the ball guide 26 are formed integrally with the valve body 5 which is the same part, cutting and grinding can be performed with high accuracy. For this reason, the clearance 30 between the ball valve 6 and the ball receiving hole 24 or the ball guide 26 is processed to have a radius (φd / 2) of the communication hole 23, and then the communication hole 23 and the ball receiving hole 24 or the ball guide 26. If the center of the ball valve 6 is processed to be less than the radius of the communication hole 23, the center of the ball valve 6 is not shifted outward from the hole diameter of the communication hole 23. Since it moves so as to follow the diameter of the valve seat 25 and the communication hole 23 can be reliably closed, the space between the communication hole 23 and the ball receiving hole 24 can be reliably sealed. As a result, the high pressure fuel in the pressure accumulation chamber 12 of the common rail 11 can be sealed so as not to overflow to the low pressure side of the fuel system, so the fuel pressure in the pressure accumulation chamber 12 of the common rail 11 is lower than the target value (target common rail pressure). Can be prevented.

[Effect of Example 1]
As described above, in the pressure reducing adjustment valve 1 of the present embodiment, the communication hole 23 and the ball accommodation hole 24 are formed coaxially, and the round communication hole is opened at the center of the bottom surface of the ball accommodation hole 24. Since the opening peripheral edge portion (valve seat) 25 of FIG. 23 is a flat surface perpendicular to the axial direction of the communication hole 23 and the ball receiving hole 24, it becomes a flat sheet. The pressure receiving pressure received by the pressure receiving portion 28 of the ball valve 6 in the direction away from the valve seat 25 from the fuel can be reduced. In addition, since the contact area of the valve seat 25 that is in close contact with the seal portion 27 of the ball valve 6 becomes extremely small and linear, the minimum load (the ball in the direction of pressing against the valve seat 25 from the armature 33 of the electromagnetic drive portion 7). The seat pressure required for sealing can be obtained by the load received by the load receiving portion 29 of the valve 6.

  Further, the ball body 26 is integrally formed on the inner wall surface of the ball receiving hole 24 of the valve body 5 to guide the ball valve 6 in the direction of the central axis of the communication hole 23 and the ball receiving hole 24. Compared with the prior art in which a mechanism for holding the ball valve 6 as a separate part is provided, the coaxiality between the communication hole 23 and the ball guide 26 is improved, so that the ball valve 6 is placed on the central axis of the communication hole 23 or in the ball housing. It becomes easy to maintain on the central axis of the hole 24. Thereby, the ball valve 6 that is a spherical body is in close contact with the valve seat 25 on the central axis of the valve seat 25 without being displaced in the radial direction from the central axis of the valve seat 25. That is, the ball valve 6 is in close contact with the opening peripheral portion (valve seat) 25 of the round hole-like communication hole 23 opened at the center of the bottom surface of the ball receiving hole 24 without being displaced in the radial direction. Therefore, it is possible to obtain the sheet surface pressure necessary for sealing with the minimum load while suppressing the pressure receiving pressure to the minimum.

  Further, in the pressure reducing adjustment valve 1 of this embodiment, the load applied to the load receiving portion 29 of the ball valve 6 in the direction in which the seal portion 27 of the ball valve 6 is pressed against the valve seat 25 as it moves to one side in the axial direction. The electromagnetic drive unit 7 includes an armature 33 that increases, a coil spring 34 that urges the armature 33 toward one side in the axial direction, and a solenoid coil 31 that attracts the armature 33 toward the other side in the axial direction. For this reason, an exciting current is supplied to the solenoid coil 31 to generate a magnetic attractive force to the solenoid coil 31, and the armature 33 is attracted to the other side in the axial direction against the spring force of the coil spring 34. The load receiving portion 29 of the ball valve 6 receives in the direction of pressing against the valve seat 25 from the armature 33 as compared to the receiving pressure received by the pressure receiving portion 28 of the ball valve 6 in the direction away from the valve seat 25 from the high pressure fuel in the hole 23. The load can be weakened. As a result, the ball valve 6 is separated from the valve seat 25 by the fuel pressure of the high-pressure fuel in the communication hole 23, so that high-pressure fuel flows into the ball receiving hole 24 from the communication hole 23 and passes around the ball valve 6. Will flow out to the low pressure chamber side.

  Further, in the case of the pressure reducing adjustment valve 1 of the present embodiment, the force for bringing the ball valve 6 into close contact with the valve seat 25 can be minimized, so that the spring force (spring constant) of the coil spring 34 is reduced. Can be set to a low value. That is, the hardness of the coil spring 34 can be softened (the elasticity of the coil spring 34 can be reduced), and the coil outer diameter and coil wire diameter of the coil spring 34 can be reduced. Since the magnetic attractive force of the solenoid coil 31 for opening the valve using pressure can be reduced, the number of turns of the solenoid coil 31 and the magnetic path area of the magnetic circuit can be reduced. Therefore, the physique of the electromagnetic drive unit 7 can be reduced in size and cost, and the physique of the entire pressure reducing valve 1 can be reduced in size and cost.

FIG. 3 shows a second embodiment of the present invention and is a diagram showing the entire structure of a normally open pressure reducing valve.
The pressure reducing adjustment valve 1 of the present embodiment is a normally open type (normally open type) pressure reducing adjusting valve. When no exciting current is supplied to the solenoid coil 31, the ball valve is controlled only by the spring force of the coil spring 34. A load is applied to the ball valve 6 in a direction in which the valve 6 is pressed against the valve seat 25. For this reason, when the fuel pressure in the high-pressure chamber 15 and the fuel pressure in the communication hole 23 exceed the spring force of the coil spring 34, the ball valve 6 opens.

  The electromagnetic drive unit 7 of the present embodiment has a solenoid coil 31 that generates a magnetic flux when energized, a stator core 32 excited by the solenoid coil 31, and a ball valve 6 in a direction in which the ball valve 6 is pressed against the valve seat 25. An armature (load applying member) 33 that applies a load (spring force) to the coil, and a coil spring 34 that urges the armature 33 in one axial direction (the valve closing direction of the ball valve 6 (the side that closes the communication hole 23)). Etc. When an excitation current is supplied to the solenoid coil 31 of this embodiment, a magnetic attractive force is generated that attracts the armature 33 in the stroke direction (one side in the axial direction), that is, in the direction of pressing the armature 33 against the ball valve 6. As a result, the load (spring force + magnetic attraction force) applied to the ball valve 6 in the direction in which the ball valve 6 is pressed against the valve seat 25 from the armature 33 is increased. That is, since the spring force of the coil spring 34 is assisted by the magnetic attractive force of the solenoid coil 31, the ball valve 6 is brought into close contact with the valve seat 25.

  According to the pressure reducing adjustment valve 1 of the present embodiment, when the supply of the excitation current to the solenoid coil 31 is stopped, the fuel pressure on the high pressure chamber side communicating with the pressure accumulation chamber 12 of the common rail 11 and the fuel pressure in the communication hole 23 are opened. If the valve pressure exceeds the valve pressure (the valve opening pressure determined by the set load of the coil spring 34), the ball valve 6 is separated from the valve seat 25 by the fuel pressure of the high-pressure fuel in the communication hole 23. The high pressure fuel flows into the hole 24 and flows out to the low pressure chamber side through the periphery of the ball valve 6.

  Further, when an exciting current is supplied to the solenoid coil 31, the armature 33 is attracted in the stroke direction by the magnetic attraction force of the solenoid coil 31 so as to assist the spring force of the coil spring 34. Then, compared to the pressure received by the ball valve 6 in the direction away from the high-pressure fuel in the communication hole 23 from the valve seat 25, the load received by the ball valve 6 in the direction pressed against the valve seat 25 from the shaft portion 44 of the armature 33 ( (Spring force + magnetic attraction force) increases.

  Thereby, even if the fuel pressure in the pressure accumulation chamber 12 of the common rail 11, the high pressure chamber 15 of the adapter 3, and the communication hole 23 of the valve body 5 is high, the ball valve 6 is brought into close contact with the valve seat 25 with a minimum load. It is possible to obtain the sheet surface pressure necessary for making it happen. In this case, the force for bringing the ball valve 6 into close contact with the valve seat 25 can be minimized, so that the number of turns of the solenoid coil 31 and the magnetic path area of the magnetic circuit can be reduced. Therefore, the physique of the electromagnetic drive unit 7 can be reduced in size and cost, and the physique of the entire pressure reducing valve 1 can be reduced in size and cost.

  FIG. 4 shows a third embodiment of the present invention, and FIGS. 4 (a) and 4 (b) show the entire structure of the pressure regulating valve.

  The pressure regulating valve 2 of this embodiment corresponds to the fluid control valve (fluid pressure control valve) of the present invention, and opens when the fuel pressure in the pressure accumulation chamber 12 of the common rail 11 exceeds the limit set pressure. The pressure limiter suppresses the fuel pressure in the pressure accumulating chamber 12 of the common rail 11 to a limit set pressure or less. The pressure regulating valve 2 includes a cylindrical housing 4 that is liquid-tightly fixed to the common rail 11, a valve body 5 that is held and fixed in the housing 4, and a bottom surface of the ball receiving hole 24 of the valve body 5. A ball (spherical) that opens and closes the fuel return path 14 of the leak pipe 13 by being seated and separated from the opening peripheral edge (valve seat) 25 of the round hole-like communication hole 23 that opens at the center of the pipe. Valve body) 6 and load applying means for applying a load to the ball valve 6 in a direction in which the ball valve 6 is pressed against the valve seat 25. The valve body 5 and the ball valve 6 constitute a ball valve (ball valve device).

  In the housing 4, a high-pressure chamber 15 and a low-pressure chamber 16 communicating with the pressure accumulation chamber 12 of the common rail 11 are partitioned in a liquid-tight manner by a valve body 5 press-fitted and fitted therein. On the outer periphery of the housing 4, an outer peripheral screw portion (male screw portion) 50 that is screwed into an inner peripheral screw portion (female screw portion) of the cylindrical portion 17 of the common rail 11 is formed. In addition, a leak port 47 that communicates with the fuel return path 14 of the leak pipe 13 is formed in the housing 4. Note that the leak port 47 is smaller in diameter than the inner diameter of the low pressure chamber 16. Here, the ball receiving hole 24 of the valve body 5 shown in FIG. 4A has an extremely larger inner diameter than the ball receiving hole 24 of the valve body 5 shown in FIG. The illustrated ball valve 6 has an extremely larger diameter (spherical diameter) than the ball valve 6 illustrated in FIG.

  The load applying means of this embodiment generates a spring force (spring constant) that urges the ball valve 6 against the valve seat 25 and is elastically deformable in the axial direction of the communication hole 23 and the ball receiving hole 24. A coil spring 9 and spring seats 51 and 52 for adjusting the spring force (strength of spring elasticity) received by the ball valve 6 in the direction in which the ball valve 6 is pressed against the valve seat 25 from the coil spring 9. It is configured.

  The coil spring 9 shown in FIG. 4 (a) is made of a metal material such as carbon steel having excellent elasticity, and uses an equal pitch coil (or an unequal pitch coil). A ball urging means that contacts and presses the ball valve 6 against the valve seat 25 and applies a spring force to the ball valve 6. The ball urging means is housed in the low pressure chamber 16 of the housing 4 and has one end in the axial direction. The ball valve 6 is locked to the load receiving portion 29, and the other end in the axial direction is locked to the spring seat 51 located on the top wall surface side of the housing 4. The spring seat 51 is an urging force adjusting member (annular plate-like plate) for adjusting the spring force (set load) of the coil spring 9. A through hole 53 that connects the low pressure chamber 16 and the leak port 47 is formed at the center of the spring seat 51. Note that the spring seat 51 illustrated in FIG. 4A may not be provided.

  On the other hand, the coil spring 9 shown in FIG. 4B is made of a metal material such as carbon steel having excellent elasticity, and uses an equal pitch coil (or an unequal pitch coil). Is a ball urging means for applying a spring force to the ball valve 6 in a direction in which the ball valve 6 is pressed against the valve seat 25 and is accommodated in the low pressure chamber 16 of the housing 4 and is axially One end is locked to the spring seat 52 that is in contact with the load receiving portion 29 of the ball valve 6, and the other end in the axial direction is locked to the top wall surface of the housing 4. The spring seat 52 is an urging force transmission member (disc-shaped plate) for adjusting the spring force (set load) of the coil spring 9 and transmitting the spring force of the coil spring 9 to the ball valve 6. A through hole 54 is formed in a portion that is dislocated from the center portion of the spring seat 52 to the outer diameter side in the radial direction. The through hole 54 is formed to discharge unnecessary fuel sandwiched between the illustrated upper end surface of the valve body 5 and the illustrated lower end surface of the spring seat 52.

  Pressure adjustment when the fuel pressure on the high-pressure chamber side communicating with the pressure accumulation chamber 12 of the common rail 11 and the fuel pressure in the communication hole 23 are lower than the valve opening pressure (the limit set pressure determined by the set load of the coil spring 9). The ball valve 6 of the valve 2 is pressed against the valve seat 25 by the spring force of the coil spring 9. At this time, since the ball guide 26 is integrally formed on the inner wall surface of the ball housing hole 24 of the valve body 5, the coaxiality between the communication hole 23 and the ball guide 26 is improved. 23 or on the central axis of the ball receiving hole 24. Thereby, the ball valve 6 can be brought into close contact with the valve seat 25 on the central axis of the valve seat 25 without the ball valve 6 being displaced in the radial direction from the central axis of the valve seat 25. Therefore, it is possible to obtain the seat surface pressure necessary for sealing with the minimum load (spring force of the coil spring 9) while suppressing the pressure receiving pressure to the minimum.

  When the fuel pressure on the high pressure chamber side communicating with the pressure accumulation chamber 12 of the common rail 11 and the fuel pressure in the communication hole 23 exceed the valve opening pressure (the limit set pressure determined by the set load of the coil spring 9), the ball valve 6 Is separated from the valve seat 25 by the fuel pressure of the high-pressure fuel in the communication hole 23, so that the high-pressure fuel flows into the ball receiving hole 24 from the communication hole 23 and flows out to the low-pressure chamber side through the periphery of the ball valve 6. It becomes like this. Thereby, the fuel pressure in the pressure accumulating chamber 12 of the common rail 11 can be suppressed below the limit set pressure.

  According to the pressure regulating valve 2 of the present embodiment, the spring force of the coil spring 9 can be suppressed to a minimum force for bringing the ball valve 6 into close contact with the valve seat 25. Thereby, since the hardness of the coil spring 9 can be softened or the coil outer diameter and the coil wire diameter of the coil spring 9 can be reduced, the size of the pressure regulating valve 2 can be reduced and the cost can be reduced. be able to. Further, when the ball valve 6 has a small diameter (spherical diameter), it is difficult to press the ball valve 6 with the coil spring 9, but as shown in FIG. If the ball valve 6 having a small ball diameter is pressed against the valve seat 25 via the valve 52, the ball valve 6 can be easily brought into close contact with the valve seat 25 using the spring force of the coil spring 9. Can be made.

  FIG. 5 shows a fourth embodiment of the present invention, FIG. 5 (a) shows a peripheral structure of the ball valve, and FIG. 5 (b) shows a valve body.

  In the first to third embodiments, when the force pressing the ball valve 6 against the valve seat 25 is weakened or eliminated, the round hole-like communication that opens at the center of the bottom surface of the ball receiving hole 24 of the valve body 5 The high-pressure fuel that has flowed into the ball receiving hole 24 from the opening end of the hole 23 is pushed in the lift direction by this fuel pressure and lifted from the valve seat 25 in the radial direction perpendicular to the axial direction of the ball valve 6. A fuel discharge path (fluid path) that flows out to the low pressure chamber side through a clearance 30 formed between the side surface and the inner peripheral surface of the ball guide 26 of the valve body 5 is employed.

  However, as the ratio of the hole diameter (inner diameter) of the communication hole 23 to the diameter (ball diameter) of the ball valve 6 increases, the high pressure passing through the clearance 30 between the ball valve 6 and the ball housing hole 24 and the inner peripheral surface of the ball guide 26. Since the flow rate of the fuel increases and becomes a flow resistance, the flow rate of the high pressure fuel does not increase, and the fuel pressure (received pressure) received from the high pressure fuel when the ball valve 6 is opened increases. Therefore, in this embodiment, as shown in FIGS. 5A and 5B, a fuel passage (fluid passage) 55 is formed inside the ball receiving hole 24 and the ball guide 26 on the outer diameter side in the radial direction. A concave groove 56 is provided so that the high-pressure fuel that has flowed into the ball receiving hole 24 from the open end of the communication hole 23 smoothly flows out to the low-pressure chamber side. As a result, even when the flow rate of the high-pressure fuel is increased, the seat surface pressure necessary for sealing can be obtained with the minimum load while suppressing the receiving pressure to a minimum as in the first to third embodiments.

[Modification]
In the present embodiment, the fluid control valve of the present invention is a pressure reducing valve 1 that recirculates or overflows the high pressure fuel in the accumulator 12 of the common rail 11 to the low pressure side (fuel tank) of the fuel system when the ball valve 6 is opened. Alternatively, although applied to the pressure regulating valve (pressure limiter) 2, the fluid control valve of the present invention is used for an injector that opens the nozzle needle by overflowing the high pressure fuel in the control chamber to the low pressure side of the fuel system. When the fuel pressure in the pressurization chamber rises above a predetermined value, the solenoid valve opens when the fuel pressure in the pressurization chamber rises above a predetermined value, and the discharge valve for the supply pump pressurizes the high-pressure fuel in the pressurization chamber to the common rail. The present invention may be applied to an overflow valve for a fuel injection pump that suppresses an abnormal increase in fuel pressure by opening the valve and overflowing to the low pressure side of the fuel system. The fluid control valve of the present invention may be applied not only to a fluid pressure control valve but also to a fluid flow rate control valve. Moreover, you may apply the fluid control valve of this invention to the fluid control valve which controls fluids, such as water, fuel, hydraulic fluid, and air.

  In the present embodiment, when the ball valve 6 is closed (fully closed), the ball valve 6 that is a spherical valve body is integrally formed on the bottom surface of the ball receiving hole 24 by the load applying means ( The ball valve 6 is separately provided on the bottom surface of the ball receiving hole 24 by the load applying means when the ball valve 6 is closed (when the ball valve 6 is fully closed). You may comprise so that it may closely_contact | adhere to the produced annular plate-shaped valve seat (opening peripheral part of an inflow hole). In this case, the valve seat may be formed of a metal material different from the material of the valve body 5.

  In the present embodiment, the ball valve 6 is made to be an annular valve by urging the armature (load applying member) 33 having the flange portion 43 and the shaft portion 44 against the ball valve 6 by the spring force of the coil spring 34. Although the load is applied to the ball valve 6 in the direction in which it is pressed against the seat (opening peripheral edge portion of the communication hole 23), the coil spring 34 is eliminated, and only the magnetic attractive force of the solenoid coil 31 of the electromagnetic drive unit 7 is eliminated. The armature (load applying member) 33 is sucked in a direction to press against the ball valve 6, thereby loading the ball valve 6 in a direction to press the ball valve 6 against the annular valve seat (opening peripheral edge portion of the communication hole 23). You may make it give. Further, the ball valve 6 is moved to the annular valve seat (opening peripheral edge portion of the communication hole 23) 25 by urging the piston or the needle (load applying member) in the direction of pressing the ball valve 6 only by the spring force of the spring. A load may be applied to the ball valve 6 in the pressing direction.

  The shaft portion 44 of the armature 33 may be slidably supported in a sliding hole provided on the central axis of the cylinder 20. Further, one end surface in the axial direction of the shaft portion 44 (the contact surface with the ball valve 6) is a flat surface, but a tapered groove that partially fits the ball valve 6 on one end surface in the axial direction of the shaft portion 44. A fitting recess such as a shape, a semicircular groove shape, or a polygonal groove shape may be provided. Further, the flange portion 43 and the shaft portion 44 may be configured as separate parts, and both may be coupled by press-fitting or welding. In this case, the flange portion 43 of the armature 33 or a separate moving core (movable core, moving body) and a valve shaft (load applying member) are used. In addition, when a cylindrical moving core is employed, the stator core is also formed in a cylindrical shape, and the moving core reciprocates in a sliding hole of the stator core so as to be slidable.

It is sectional drawing which showed the surrounding structure of a ball valve (Example 1). It is sectional drawing which showed the whole structure of the normally closed pressure-reduction control valve (Example 1). (Example 2) which is sectional drawing which showed the whole structure of the normally open type pressure-reducing control valve. (A), (b) is sectional drawing which showed the whole structure of the pressure regulation valve (Example 3). (A) is sectional drawing which showed the periphery structure of a ball valve, (b) is the top view which showed the valve body (Example 4).

Explanation of symbols

1 Depressurization regulating valve (fluid control valve, fluid pressure control valve)
2 Pressure regulating valve (fluid control valve, fluid pressure control valve)
4 Housing for pressure regulating valve 5 Valve body (valve seat)
6 Ball valve (spherical valve body)
7 Electromagnetic drive (loading means)
9 Pressure regulating valve coil spring (loading means, ball biasing means)
DESCRIPTION OF SYMBOLS 11 Common rail 12 Accumulation chamber 13 Leak piping 14 Fuel return path 15 High pressure chamber 16 Low pressure chamber 23 Communication hole (inflow hole)
24 Ball hole (recess)
25 Valve seat (opening edge of inflow hole, valve body valve seat)
26 Ball guide (valve guide, regulating surface)
27 Ball sealing part 28 Ball pressure receiving part (pressure receiving part)
29 Ball load receiving portion 30 Clearance 31 Solenoid coil 33 Armature (loading member)
34 Coil spring of pressure reducing valve (ball urging means, valve urging means)
35 Housing for pressure reducing adjustment valve 47 Leak port for housing 51 Spring seat (biasing force adjusting member)
52 Spring seat (biasing force transmission member)
55 Fuel passage (fluid passage)

Claims (11)

A concave body having a bottom surface, and a valve body having an inflow hole for opening a high-pressure fluid into the concave portion, which opens at the bottom surface of the concave portion;
A ball valve that is movably accommodated in the recess, and is seated and separated from the opening peripheral edge of the inflow hole to close and open the inflow hole;
Load applying means for applying a load to the ball valve in a direction in which the ball valve is pressed against the peripheral edge of the opening of the inflow hole,
When the load is larger than the pressure received from the high-pressure fluid, the ball valve is seated on the peripheral edge of the inflow hole to close the inflow hole, and when the load is smaller than the pressure, In the fluid control valve that opens from the peripheral edge of the inflow hole and opens the inflow hole,
The inflow hole is formed coaxially with the recess,
The fluid control valve according to claim 1, wherein an opening peripheral edge portion of the inflow hole is a flat surface substantially perpendicular to an axial direction of the recess or the inflow hole. The fluid control valve according to claim 1,
The fluid control valve according to claim 1, wherein the bottom surface of the recess is a restriction surface that restricts a movement range of the ball valve in the axial direction. The fluid control valve according to claim 1 or 2,
The valve body is integrally formed with a ball guide for guiding the ball valve in a direction of a central axis of the recess or the inflow hole. The fluid control valve according to claim 3,
The fluid control valve according to claim 1, wherein the wall surface of the ball guide is a restricting surface that restricts a radial movement range of the ball valve. In the fluid control valve according to claim 3 or 4,
The fluid guide valve, wherein the ball guide has a clearance through which a high-pressure fluid can flow between the ball guide and the ball valve. The fluid control valve according to claim 5,
The fluid control valve according to claim 1, wherein the valve body has a fluid passage through which a high-pressure fluid can circulate on a radially outer side of the ball guide. The fluid control valve according to any one of claims 1 to 6,
The load applying means includes a load applying member that applies a load to the ball valve in a direction in which the ball valve is pressed against the peripheral edge of the opening of the inflow hole, and a ball that urges the load applying member in a direction in which the load applying member is pressed against the ball valve. A fluid control valve comprising: a biasing means; and a coil that generates a magnetic attraction force that attracts the load applying member in a direction away from the ball valve when energized. The fluid control valve according to any one of claims 1 to 6,
The load applying means includes a load applying member that applies a load to the ball valve in a direction in which the ball valve is pressed against the peripheral edge of the opening of the inflow hole, and a magnetic attraction that attracts the load applying member in a direction to press the ball valve. A fluid control valve comprising a coil for generating a force. The fluid control valve according to any one of claims 1 to 6,
The fluid control valve according to claim 1, wherein the load applying means includes ball urging means that urges the ball valve in a direction in which the ball valve is pressed against an opening peripheral edge of the inflow hole. The fluid control valve according to any one of claims 1 to 6,
The load applying means includes ball urging means for urging the ball valve in a direction in which the ball valve is pressed against the peripheral edge of the opening of the inflow hole, and an urging force adjusting member for adjusting the urging force of the ball urging means. A fluid control valve characterized by The fluid control valve according to any one of claims 1 to 6,
The load applying means includes a ball urging means for urging the ball valve in a direction to press the ball valve against the peripheral edge of the opening of the inflow hole, and an urging force transmitting member for transmitting the urging force of the ball urging means to the ball valve. A fluid control valve characterized by comprising:

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