JP4858464B2 - Solenoid valve and fuel injection valve - Google Patents

Description

  The present invention relates to a solenoid valve and a fuel injection valve including the solenoid valve.

  Conventionally, a fuel injection valve provided with an electromagnetic valve has been known (see Patent Document 1).

  In this fuel injection valve, the back pressure of the piston interlocked with the nozzle needle is controlled by opening and closing the electromagnetic valve, thereby moving the nozzle needle up and down. The nozzle hole is closed by moving the nozzle needle downward, and the nozzle hole is opened by moving the nozzle needle upward to inject fuel from the nozzle hole.

The electromagnetic valve includes a movable core that can reciprocate, a valve member that reciprocates in cooperation with the movable core, an electromagnetic coil, a fixed core that is excited when the electromagnetic coil is energized and sucks the movable core, and this suction A biasing member that biases the movable core in a direction opposite to the direction. When the electromagnetic coil is energized, the fixed core attracts the movable core, the valve member is separated from the valve seat, and when the energization to the electromagnetic coil is stopped, the spring of the biasing member pushes the movable core, and the valve member Sit on the seat. Accordingly, by alternately energizing and de-energizing the electromagnetic coil, the electromagnetic valve opens and closes, whereby the fuel injection valve opens and closes the injection hole to control fuel injection from the injection hole.
JP-A-9-42106

  In the solenoid valve of Patent Document 1, the receiving seat that receives the pushing force of the spring is formed on the movable core. Therefore, the receiving seat is placed against the spring due to dimensional errors of each component, assembly errors, and the like. Tilt. Since the spring is seated and assembled to the inclined seat, a force in a direction deviating from the moving direction of the movable core acts on the seat from the spring, and this force acts on the movable core. For this reason, when this inclination is large, the force acting in a direction deviating from the moving direction of the movable core increases, and the responsiveness of opening and closing of the electromagnetic valve is deteriorated, or the sliding portion of the movable core is worn. This may cause the durability of the solenoid valve to deteriorate.

  As a counter-action, a force in a direction deviating from the direction in which the spring is pushed acts on the spring from the inclined seat, so that the spring chamber in which the spring is housed and the spring are worn, resulting in the durability of the solenoid valve. May get worse.

  The present invention has been made in view of such circumstances, and includes a solenoid valve capable of suppressing the inclination of the receiving seat of the biasing member with respect to the biasing member, and a fuel injection valve including the solenoid valve. The purpose is to provide.

  In order to achieve the above object, the present invention employs the following technical means.

According to a first aspect of the present invention, there is provided a solenoid valve having a movable core capable of reciprocating movement, a valve seat having a valve hole formed therein, reciprocating in cooperation with the movable core, and being seated on the valve seat and separated from the valve seat. A valve member that sits and opens and closes the valve hole, an electromagnetic coil, a fixed core that is excited when the electromagnetic coil is energized and attracts the movable core in a direction in which the valve member is separated, and a movable core in a direction in which the valve member is seated An urging member that urges the urging member, and a transmission portion that is interposed between the movable core and the urging member, and that transmits the urging force of the urging member received from the urging member to the movable core. and a guide member having bets, the transmitting portion, formed by a curved surface of the recess, the abutting portion, to face the transmitting unit as a curved recess formed in the movable core, the movable core and the guide Spherical or oval spherical intermediate member interposed between members, both of the transmission part and the contact part Characterized Rukoto includes a slidably contacting the intermediate member.

  According to the first aspect of the present invention, the guide member that is separate from the movable core and the biasing member is interposed between the movable core and the biasing member, and the seat for the biasing member is provided on the guide member. Yes. For this reason, the inclination of the receiving seat with respect to the urging member can be suppressed by adjusting the relative positional relationship of the guide member with respect to the movable core and the urging member.

In addition , according to the invention described in claim 1, since the sliding structure is provided between the movable core and the intermediate member and between the intermediate member and the guide member, the guide member for the movable core and the biasing member is provided. Can be adjusted smoothly.

According to the invention described in claim 2, a conical recess, the intermediate member which abut slidably in the recess, the sphere-shaped or formed into elliptic spherical slidable by the recess and the intermediate member It has a simple structure. Since the contact portion between the recess and the intermediate member is circular and linear, the force acting on the contact portion is easily uniformed in the circumferential direction. For this reason, between the guide member and the movable core, a force acting in a direction deviating from the moving direction of the movable core is suppressed. Therefore, the deterioration of the responsiveness of opening and closing of the electromagnetic valve and the deterioration of the durability of the electromagnetic valve can be further suppressed.

According to the invention of claim 3 , since the electromagnetic valve according to claim 1 or 2 can obtain the above-described effect, the back pressure of the piston can be controlled with high accuracy. For this reason, the fuel injection valve using this solenoid valve can control fuel injection with high precision.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the mutually same or equivalent part in a figure.

  A fuel injection valve 10 shown in FIG. 1 is inserted and mounted in an engine head of an engine (not shown), and is configured to directly inject fuel into each cylinder of the engine. The fuel injection valve 10 includes an electromagnetic valve 1 that controls the pressure in the back pressure control chamber 21, a nozzle body 11 having an injection hole 111 formed at the tip thereof, and a nozzle needle 12 that opens and closes the injection hole 111. And a piston 13 that reciprocates by pressure control of the back pressure control chamber 21.

  The piston 13 is configured to be able to reciprocate in the lower body 14 in the vertical direction in FIG. 1 and to be interlocked with the nozzle needle 12. When the piston 13 moves upward in FIG. 1, the nozzle needle 12 also moves upward. When the piston 13 moves downward in FIG. 1, the nozzle needle 12 also moves downward.

  The high-pressure fuel flows from the fuel inflow passage 141 formed in the lower body 14, and the nozzle needle 12 moves upward to open the nozzle hole 111, and then from the nozzle hole 111 through the fuel passage 142 and the fuel reservoir 112. Be injected. The high-pressure fuel that has flowed in from the fuel inflow passage 141 reaches the back pressure control chamber 21 through the fuel passage 143.

  In a state in which the nozzle needle 12 moves downward and the nozzle hole 111 is closed, the fuel reservoir 112 is at a high pressure due to the high-pressure fuel that has flowed from the fuel inflow passage 141. On the other hand, even in the state where the nozzle hole 111 is closed, the pressure in the back pressure control chamber 21 is reduced by the pressure control of the back pressure control chamber 21 by the solenoid valve 1 described later. For this reason, the nozzle needle 12 moves upward in conjunction with the piston 13 due to the differential pressure between the high-pressure fuel reservoir 112 and the low-pressure back pressure control chamber 21. As a result, the injection hole 111 is opened and high-pressure fuel is injected from the injection hole 111.

  On the other hand, when the pressure of the back pressure control chamber 21 is controlled to a high pressure by the pressure control of the back pressure control chamber 21 by the solenoid valve 1, the differential pressure between the high pressure fuel reservoir 112 and the high pressure back pressure control chamber 21 disappears. For this reason, the nozzle needle 12 moves downward in conjunction with the piston 13 to close the nozzle hole 111. As described above, the injection hole 111 is controlled to be opened and closed by the pressure control of the back pressure control chamber 21 by the electromagnetic valve 1.

  Next, the solenoid valve 1 will be described with a focus on the pressure control configuration of the back pressure control chamber 21.

  As shown in FIG. 2, the electromagnetic valve 1 includes a plate 2, a valve body 4 in which a sliding hole 41 is formed, an armature 3 that can reciprocate in the sliding hole 41, and an armature 3 in the sliding hole 41. The valve member 33, the electromagnetic coil 51, the stator 5, the spring 6, and the spring guide 7 that reciprocally slide in cooperation with the motor are provided.

  A valve hole 23 and a valve seat 22 are formed in the plate 2, and the plate 2 is positioned and fixed inside the lower body 14 with a pin. The back pressure control chamber 21 is formed by the outer end wall of the piston 13, the inner wall 144 of the lower body 14, and the inner wall 24 of the plate 2.

  As shown in FIGS. 2 and 3, the valve member 33 formed in a substantially spherical shape is formed with a flat surface portion 34 that is seated on the valve seat 22 and separated from the valve seat 22 to open and close the valve hole 23. The valve member 33 is slidably engaged with the armature 3 on the side opposite to the flat portion 34.

  In FIG. 2, the armature 3 is provided with a substantially disc-like wing 31 and is biased by the spring 6 through the spring guide 7 in the direction in which the valve member 33 is seated (downward in FIG. 2). The stator 5 which is energized and excited is attracted in the direction in which the valve member 33 is separated (upward in FIG. 2). The electromagnetic coil 51 is energized by the terminal 52, and when not energized, the armature 3 is not attracted to the stator 5, so the valve member 33 is biased toward the valve hole 23 by the spring 6 via the spring guide 7 and the armature 3. Is done.

  The spring 6 is accommodated in a spring chamber 611 formed in the cylindrical body 61 and the like, and a biasing force (so-called set load) by which the spring 6 biases the armature 3 is adjusted by a shim 62.

  The spring guide 7 is interposed between the armature 3 and the spring 6, and receives a seat 71 that receives the urging force of the spring 6, a hemispherical convex portion 72, and a press-fit portion that is lightly press-fitted inside the spring 6. 73. The convex portion 72 slidably contacts the conical and concave sliding surface 32 formed on the armature 3 and transmits the urging force of the spring 6 received from the receiving seat 71 to the armature 3.

  The armature 3 corresponds to the movable core described in the claims, the sliding surface 32 corresponds to the contact portion described in the claims, and the stator 5 corresponds to the fixed core described in the claims. The spring 6 corresponds to the urging member described in the claims, the spring guide 7 corresponds to the guide member described in the claims, and the convex portion 72 corresponds to the transmission portion described in the claims.

  Back pressure acts on the flat surface portion 34 from the back pressure control chamber 21 through the valve hole 23, but the biasing force of the spring 6 resists this back pressure and causes the flat surface portion 34 of the valve member 33 to act on the valve seat 22. Set to sit down. Thereby, when the electromagnetic coil 51 is not energized, the flat portion 34 is seated on the valve seat 22 and closes the valve hole 23, and thus the back pressure control chamber 21 is maintained at a high pressure.

  On the other hand, when the electromagnetic coil 51 is energized, the excited stator 5 attracts the armature 3. The suction force and the back pressure in the back pressure control chamber 21 are set so that the flat portion 34 of the valve member 33 is separated from the valve seat 22 against the biasing force of the spring 6. As a result, when the electromagnetic coil 51 is energized, the flat portion 34 is separated from the valve seat 22 and opens the valve hole 23, so that the back pressure in the back pressure control chamber 21 is reduced to a low pressure.

  Even when the valve hole 23 is open, the high-pressure fuel flows into the back pressure control chamber 21 through the fuel passage 143, but the amount of outflow from the valve hole 23 is larger than the amount of inflow. For this reason, even when the valve hole 23 is opened and the back pressure control chamber 21 is controlled to a low pressure, when the energization to the electromagnetic coil 51 is stopped, the flat portion 34 is seated on the valve seat 22 and the valve hole 23 is opened. Block. For this reason, when the high pressure fuel flows into the back pressure control chamber 21 through the fuel passage 143, the back pressure control chamber 21 is controlled to a high pressure.

  Therefore, the back pressure of the back pressure control chamber 21 is controlled by turning on / off the energization of the coil 6, thereby controlling the opening / closing of the nozzle hole 111.

  With the above configuration, the armature 3 and the spring 6 are separated from the spring guide 7 between the armature 3 and the spring 6, and the receiving seat 71 of the spring 6 is provided in the spring guide 7. For this reason, the inclination of the receiving seat 71 with respect to the spring 6 can be suppressed by adjusting the relative positional relationship of the spring guide 7 with respect to the armature 3 and the spring 6.

  Specifically, the armature 3 and the spring guide 7 are configured to be slidable from a conical sliding surface 32 and a hemispherical convex portion 72 that slidably contacts the sliding surface 32, thereby The relative positional relationship of the spring guide 7 with respect to the armature 3 and the spring 6 can be adjusted smoothly. Therefore, the inclination of the receiving seat 71 with respect to the spring 6 can be suppressed.

  For example, as shown in FIG. 4, even when the inclination of the spring 6 including the spring chamber 611 with respect to the armature 3 is large due to the dimensional error of each component or the assembly error thereof, the sliding surface 32 and the convex portion By sliding 72, the inclination of the receiving seat 71 with respect to the spring 6 can be suppressed. In FIG. 4, the inclination of the spring 6 with respect to the armature 3 is highlighted for easy understanding.

  On the other hand, in the comparative example shown in FIG. 5, the armature 30 is formed with a receiving seat 301 that receives the urging force of the spring 6 and a press-fit portion 302 that is lightly press-fitted inside the spring 6. Since the spring 6 is seated and assembled to the receiving seat 301 inclined with respect to the spring 6, a force in a direction deviating from the moving direction of the armature 30 (vertical direction in FIG. 5) acts on the receiving seat 301 from the spring 6. This force acts on the armature 30. As this reaction, a force in a direction shifted from the biasing direction of the spring 6 (longitudinal direction of the spring 6) acts on the spring 6 from the inclined receiving seat 301.

  As shown in FIG. 5, when the inclination of the spring 6 with respect to the armature 30 is large, when the press-fitting portion 302 is lightly press-fitted inside the spring 6 in order to assemble the spring 6 to the armature 30, the spring 6 is Deform as shown. The spring force generated in the spring 6 by this deformation acts on the armature 30 in a direction (left and right direction in FIG. 5) that is shifted from the moving direction of the armature 30. For this reason, the slidability of the armature 30 deteriorates in the sliding hole 41, and the responsiveness of opening and closing the valve hole 23 deteriorates. Further, the armature 30 and the sliding hole 41 are worn, and the durability of the solenoid valve 1 may be deteriorated.

  Due to the deformation of the spring 6 due to the inclination, the spring chamber 611 and the spring 6 are worn, and the durability of the solenoid valve 1 may be deteriorated. In FIG. 5, for easy understanding, the inclination of the spring 6 with respect to the armature 30 is emphasized, and the spring chamber 611 is worn and deformed by the deformation of the spring 6.

  On the other hand, as shown in FIGS. 1-4, in this invention, since the inclination of the receiving seat 71 with respect to the spring 6 can be suppressed, the problem which arises in the comparative example shown in FIG. 5 can be eliminated.

  As described above, since the hemispherical convex portion 72 is slidably brought into contact with the conical and concave sliding surface 32, the contact portion between the sliding surface 32 and the convex portion 72 is against the armature 30. Regardless of the degree of inclination of the spring 6, it is circular and linear. For this reason, the force acting on the contact portion is easily uniformed in the circumferential direction. It can be suppressed. Therefore, the deterioration of the responsiveness of opening and closing of the valve hole 23 and the deterioration of the durability of the electromagnetic valve 1 can be suppressed.

  As described above, the fuel injection valve 10 using the electromagnetic valve 1 capable of controlling the back pressure in the back pressure control chamber 21 with high accuracy can control the fuel injection from the injection hole 111 with high accuracy.

(Modification)
The convex portion 72 can be formed in a semi-elliptical spherical shape, and the sliding surface 32 can be formed in a curved concave shape that can slide with the semi-elliptical spherical convex portion.

  In the armature 3A and the spring guide 7A shown in FIG. 6, a conical and concave sliding surface 72A is formed on the spring guide 7A, and a hemispherical convex portion 32A that slidably contacts the sliding surface 72A is formed on the armature 3A. It is possible to form.

  In FIG. 7, a spherical ball joint 35 can be slidably brought into contact with the sliding surfaces 32 and 72A by being interposed between the armature 3 and the spring guide 7A.

(Reference example)
In the armature 3B and the spring guide 7B shown in FIG. 8, the flat plane portion 72B is formed in the spring guide 7B, the flat plane portion 32B is formed in the armature 3B, and the plane portions 32B and 72B are brought into contact with each other. It is possible to

In the present reference example, the plane portions 32B and 72B are not structured to contact each other so as to be slidable, but the armature 3B and the spring 6 and a separate spring guide 7B are interposed between the armature 3B and the spring 6, A receiving seat 71 for the spring 6 is provided on the spring guide 7B. For this reason, the inclination of the receiving seat 71 with respect to the spring 6 can be suppressed by adjusting the relative positional relationship of the spring guide 7B with respect to the armature 3B and the spring 6.

  As shown in FIG. 9, even when the inclination of the spring 6 with respect to the armature 30 is large, the inclination of the receiving seat 71 with respect to the spring 6 can be suppressed by the arrangement in which the flat part 72B is inclined with respect to the flat part 32B. For this reason, the problem which arises in the comparative example shown in FIG. 5 can be solved.

  The armatures 3A and 3B correspond to the movable core according to the claims, the convex portions 32A and the flat surface portion 32B correspond to the contact portions according to the claims, and the ball joint 35 includes the intermediate member according to the claims. It corresponds to. The spring guides 7A and 7B correspond to the guide member described in the claims, and the sliding surface 72A and the flat portion 72B correspond to the transmission portion described in the claims.

  In FIG. 9, the inclination of the spring 6 with respect to the armature 3 </ b> B is emphasized for easy understanding.

It is a longitudinal cross-sectional view of the fuel injection valve provided with the solenoid valve by one Embodiment of this invention. It is an expanded sectional view of the II section in FIG. It is an expanded sectional view of the III section in FIG. It is typical sectional drawing for demonstrating this invention. It is a typical sectional view for explaining a comparative example. It is an expanded sectional view which shows the 1st modification of FIG. It is an expanded sectional view which shows the 2nd modification of FIG. It is an expanded sectional view which shows the reference example of FIG. It is a typical sectional view for explaining a reference example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel injection valve, 11 Nozzle body, 111 Injection hole, 112 Fuel pool 12 Nozzle needle, 13 Piston, 14 Lower body 141 Fuel inflow path, 142, 143 Fuel path, 144 Inner wall, 1 Solenoid valve 2 Plate, 21 Back pressure control chamber, 22 valve seat, 23 valve hole, 24 inner wall 3, 3A, 3B armature (movable core), 31 wings, 32 sliding surface (contact part, recess)
32A Convex part (contact part), 32B Flat part (contact part), 33 Valve member, 34 Flat part 35 Ball joint (intermediate member), 30 Armature (comparative example)
301 receiving seat, 302 press-fitting part, 4 valve body, 41 sliding hole 5 stator (fixed core), 51 electromagnetic coil, 52 terminal 6 spring (biasing member), 61 cylinder, 611 spring chamber, 62 shim 7 spring guide (Guide member), 71 receiving seat, 72 convex part (transmission part)
72A Sliding surface (transmission part, recess), 72B Flat part (transmission part), 73 Press-fit part

Claims (3)

A movable core capable of reciprocal movement;
A valve seat formed with a valve hole;
A valve member that reciprocally moves in cooperation with the movable core, and that opens and closes the valve hole by being seated on the valve seat and separated from the valve seat;
An electromagnetic coil;
A fixed core that is excited when the electromagnetic coil is energized and attracts the movable core in a direction in which the valve member is separated; and
A biasing member that biases the movable core in a direction in which the valve member is seated;
It is interposed between the movable core and the urging member, and has a receiving seat for the urging member, and a transmission portion for transmitting the urging force of the urging member received from the receiving seat to the movable core. A guide member,
Said transmission portion, formed by a curved surface of the recess,
A contact portion is formed on the movable core as a curved concave portion so as to face the transmission portion,
An intermediate member of spherical or ellipsoidal shape are interposed between the guide member and the movable core, and wherein Rukoto includes a slidably contacting the intermediate member on both the contact portion and the transmitting portion Solenoid valve. Solenoid valve according to claim 1, the recess, characterized that you have formed a concave conical. A fuel injection valve comprising the electromagnetic valve according to claim 1 or 2, wherein an injection hole into which fuel is injected is formed at a tip portion,
A nozzle needle for opening and closing the nozzle hole;
By controlling the back pressure by opening and closing the valve hole, a fuel injection valve, characterized in Rukoto and a piston which reciprocates in association with the nozzle needle.

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