JP2006194351A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plunger type solenoid valve having reduced cost and size by using a plunger for sliding along a shaft to move a spool in the axial direction so that a valve port is controlled to be opened/closed with the movement of the spool. <P>SOLUTION: The solenoid valve comprises the spool slidably inserted into a housing having a plurality of ports for opening/closing the ports, an energizing member for energizing the spool in one direction, and a boss fixed into a case forming a magnetic circuit arranged on one axial end side of the spool for supporting the spool passing therethrough. The plunger is supported on the shaft fixed into the case on the same axial line as that of the spool movably in the axial direction, and the end face of the spool is thrust against the front end face on one end side thereof. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plunger type electromagnetic valve applied to, for example, a hydraulic control system of a valve timing device of an internal combustion engine.

  In a general plunger type solenoid valve, as shown in Patent Document 1, a shaft press-fitted and fixed to the plunger is slidably supported by two bearing members, and the shaft and the spool are brought into contact with each other to transmit the operation. As disclosed in Patent Document 2, there is a type in which a plunger is slidably supported by a shaft fixedly supported by a fixing member, and a ball valve body is directly pressed and moved by the sliding plunger.

Japanese Patent Laid-Open No. 10-122404 ([0013], FIG. 1) Japanese Patent Laying-Open No. 2003-49963 ([0015], [0016], FIGS. 1 and 2)

  Since the conventional solenoid valve is configured as described above, the one described in Patent Document 1 uses two bearing members, so that the number of parts is large, the assembly is complicated, and the cost is low. Take it. In addition, a space for the bearing portion equivalent to the plunger is required, and it is difficult to reduce the size of the solenoid valve. Further, since it is difficult to secure the coaxial between the bearing members, it causes a sliding abnormality. Then, since the shaft is press-fitted and fixed to the plunger and the operation of the plunger is transmitted by the shaft and the spool coming into contact with each other, tilting the shaft and complicating the structure are problematic during the operation transmission.

  On the other hand, what is described in Patent Document 2 is such that the ball valve body (fluid port portion) and the plunger operation transmitting portion are the same place, that is, the ball valve body is directly pressed and moved by the plunger. The structure (spool valve type) is completely different.

  The present invention has been made to solve the above-described problems. The spool is moved in the axial direction by a plunger that slides along a fixed shaft, and the opening and closing of the valve port is controlled by the movement of the spool. Thus, it is an object of the present invention to obtain a solenoid valve that is effective for cost reduction and miniaturization.

  An electromagnetic valve according to the present invention includes a housing having a plurality of ports, a nonmagnetic spool that is slidably inserted into the housing to open and close the ports, and a biasing member that biases the spool in one direction. A case forming a magnetic circuit disposed on one end side of the spool in the axial direction, a boss that is fixed in the case and supports the spool, and is fixed in the case on the same axis as the spool. And a magnetic plunger that is supported by the shaft so as to be movable in the axial direction and that moves by pressing the end face of the spool at the end face on the magnetic attraction side.

  In the solenoid valve according to the present invention, the spool is penetrated and supported by a boss fixed in the case, and the end surface of the spool is pressed to the shaft fixed in the case on the same axis as the spool by the end surface on the magnetic attraction side. Since the plunger for moving the spool is supported so as to be movable in the axial direction, the bearing member can be eliminated, and the structure can be greatly simplified (the axial length is shortened) and the cost can be reduced. . In addition, the plunger operation can be directly transmitted to the spool, so that it is possible to prevent inconveniences and adverse effects such as eccentricity, inclination, or part cost increase when the plunger is pressed into the shaft, which can occur in the conventional structure. Furthermore, by contacting the spool at the outer periphery of the shaft sliding hole of the plunger, the contact area can be larger than the conventional shaft cross-sectional area. There is an effect that can be prevented.

Embodiment 1 FIG.
The drawings show a sectional view in the axial direction of the solenoid valve according to Embodiment 1 of the present invention. FIG. 1 is an OFF state diagram for energization of the solenoid valve, FIG. 2 is an ON status diagram for the solenoid valve, and FIG. Is a cross-sectional view taken along line AA in FIG. 1, and FIG. 4 is a cross-sectional view taken along line BB in FIG.

  The electromagnetic valve shown in the figure is a housing 1 having a plurality of ports 51 to 57 for fluid passage connection, and a nonmagnetic member that is slidably inserted in the housing 1 in the axial direction to open and close the ports 51 to 57. A spool 2, a spring 3 that biases the spool 2 in one axial direction, and a case 4 that forms a cylindrical magnetic circuit connected to one axial end of the housing 1 are provided.

  The housing 1 is open to a substantially cylindrical outer peripheral sleeve surface, and is a supply port 51 that receives supply of hydraulic oil from an oil pump (not shown), for supplying hydraulic oil to an advance side hydraulic chamber of a hydraulic actuator (not shown). The advance side supply port 52, the retard side supply port 53 for supplying hydraulic oil to the retard side hydraulic chamber of the hydraulic actuator, the advance side drain port 54 for discharging the hydraulic oil from the advance side hydraulic chamber, the retard A retarded-side drain port 55 that discharges hydraulic oil from the angle-side hydraulic chamber, and two end drain ports 56 that release pressure due to leaked oil generated at both ends of the spool 2 described later and air pressure during spool movement to the atmosphere. , 57 are formed. In addition, a plurality of thresholds 58 for forming respective oil passages are formed on the inner diameter side. Further, one end portion has a larger diameter base end portion 59 that has a larger diameter than the outer peripheral sleeve surface and to which the end portion 4b of the case 4 is caulked when the housing is fixed.

  The spool 2 can move a predetermined amount in the axial direction within the housing 1 and has a plurality of land portions 60 and a plurality of recesses 61, and the amount of oil supplied to the hydraulic actuator and the amount of discharged oil can be adjusted by the amount of movement. It is. Here, since one end surface of the spool 2 comes into contact with the plunger as will be described later, the spool 2 penetrates the inner diameter portion of the boss 13 and enters the solenoid valve, that is, the solenoid. For this reason, the spool 2 is made of aluminum (non-magnetic) in order to prevent the spool 2 from affecting the magnetic circuit when energized, or adsorbing foreign matter by magnetizing the spool 2 and affecting the slidability. Material). In addition, by doing so, there is a merit that the spool 2 is lightened and the seismic resistance of the movable part is improved.

  The spring 3 is inserted into the end of the spool inside the housing, and always urges the spool 2 in the direction of arrow A. The washer 20 is installed on the bottom surface of the housing 1 and constitutes the seating surface of the spring 3.

  The case 4 has a bottomed substantially cylindrical shape having a bottom portion 4a, and all circumferential step portions 4b and 4c are formed on inner peripheral surfaces of both end portions in the axial direction. In addition, a notch 4d for installing a connector 6 described later is formed in the opening opposite to the bottom 4a. A bracket 18 that is fastened by a bottle or the like is fixed to the outer periphery of the case 4 by means of welding or the like when the electromagnetic valve is attached to a cylinder head or the like of the engine.

  A coil body 5 is provided in the case 4. The coil body 5 is integrally formed with a connector part 6 at one end and a coil exterior part 5b on the other side by resin molding. The connector portion 6 is formed so as to protrude outward from the outer peripheral surface of the coil body 5, and protrudes from the notch portion 4 d of the case 4 to the outside of the case when the coil body 5 is stored in the case 4.

A bobbin 7, a coil 8, and a terminal 9 are insert-molded in the coil body 5, respectively. The core 10 is a magnetic circuit component and includes a flange portion 10a and a cylinder portion 10b. The outer peripheral surface of the flange portion 10a is held by the step portion 4c of the case 4, and is fixed by caulking the step portion 4c. Moreover, the cylinder part 10b accommodates the plunger 12 mentioned later in the inner peripheral side, The several recessed part 10c for oil draining is formed in the plunger accommodating part. Further, a hole 10d for fixing a shaft 11 to be described later is formed on the bottom surface of the cylindrical portion 10b. A boss (fixed iron core) 13 made of a magnetic material and having a substantially cylindrical shape is press-fitted and fixed in a hole 4e formed at the center of the bottom 4a of the case 4. The boss 13 is generally composed of a magnetic attraction portion 13a, a plunger facing surface 13b, and a cylindrical portion 13c. In addition, the operation | movement regulation is performed because the plunger 12 mentioned later contact | abuts to the inner peripheral bottom part of the cylinder part 10b of a core (fixed iron core), and the plunger opposing surface 13b of the boss | hub 13.
In addition, since the plunger 12 is directly slidably supported by a shaft press-fitted and fixed to the core 10, the coaxiality between the plunger 12 and the plunger accommodating portion (cylinder portion 10b) of the core 10 is greatly improved as compared with the conventional structure. Since it is possible, the clearance between the plunger and the plunger accommodating portion can be reduced. Thereby, magnetic efficiency can be improved.

  The shaft 11 is made of a nonmagnetic material and has a straight shape. One end of the shaft 11 is fixed by press-fitting into a hole 10d formed in the bottom surface of the cylindrical portion 10b of the core 10. The plunger 12 as a mover is formed by powder metallurgy or forging from a magnetic metal, and has a simple cylindrical shape. The plunger 12 has a sliding hole 12a penetrating in the axial direction, and is supported by the sliding hole 12a so as to be movable in the axial direction by a predetermined amount on the free end side of the shaft 11. One end surface (magnetic attraction side) of the plunger 12 is in contact with the end surface of the spool 2 around the sliding hole 12a, so that the operation of the plunger 12 can be transmitted to the spool 2. Further, as shown in FIG. 2, the spool abutting portion of the plunger 12 is provided with a sliding hole 12a to prevent air pressure due to the plunger sliding in the space of the sliding hole 12a due to the spool abutting. A plurality of notched grooves 12b communicating with the internal space of the solenoid part are formed. The groove 12b is formed at the same time as the plunger 12 is molded, and processing or the like is not necessary. In addition, by this groove 12b, foreign matter (friction powder or the like) that enters from the outside or is generated inside flows out from the sliding portion of the shaft 11 and the plunger 12, thereby preventing accumulation on the sliding portion, It is also effective against foreign matter.

  On both axial end surfaces of the plunger 12, rubber portions 12c and 12d functioning as a magnetic stopper when the plunger 12 abuts against the core 10 and the boss 13 are installed. The rubber portions 12c and 12d are formed by nonmagnetic rubber baking. That is, a rubber portion 12d is formed to protrude from one end surface where the spool contact portion is present so as to have an inner diameter larger than the outer diameter of the spool contact portion. The shaft 11 and the plunger 12 are configured so that the edge of the sliding hole 12a and the edge of the shaft 11 do not interfere (do not overlap) when the plunger 12 is in any operating state.

  The shaft 11 is usually made of a non-magnetic high-hardness stainless steel material, but there is a large difference in surface hardness with the plunger 12 that often uses pure iron-based non-quenched material. Wear and may affect durability. In such a case, a hard surface treatment may be applied to the shaft sliding portion of the plunger 12.

Next, the operation will be described.
When the energization of the coil 8 is turned off, the spool 2 is held in the state shown in FIG. 1 in which the end portion on the counter suction side is pressed against the plunger 12 by the biasing force of the spring 3. In this state, when the coil 8 is energized, the plunger 12 pushes the spool 2 in a direction against the urging force of the spring 3 by the magnetic attractive force generated on the boss 13 side. Thereby, the ports 51 to 57 of the housing 1 are switched to a predetermined fluid flow path by the spool 2. Then, at the full stroke position of the plunger 12 by the magnetic attraction force, as shown in FIG. 2, the rubber portion 12c protruding from the attraction side end portion of the plunger 12 contacts the plunger facing surface 13b of the boss 13. Is held in the state. In this way, at the full stroke position of the plunger 12, the nonmagnetic rubber portion 12 c blocks between the magnetic suction side end of the plunger 12 and the plunger facing surface 13 b of the boss 13, so that the coil 8 is energized. At the time of OFF, the plunger 12 can be quickly responsive to the initial position shown in FIG.

  As described above, according to the first embodiment, the spool 2 is penetrated and supported by the boss 13 fixed in the case 4, and the shaft 11 fixed in the case on the same axis as the spool 2 is magnetically connected. Since the magnetic plunger 12 that presses and moves the end surface of the spool 2 at the suction side end surface is supported so as to be movable in the axial direction, the bearing member can be eliminated, and the structure can be greatly simplified. (Reduced direction length) and cost reduction. In addition, since the plunger operation that moves along the fixed shaft is directly transmitted to the spool 2, there is a problem that may occur in the conventional structure such as eccentricity, inclination, or increase in parts cost when the plunger 12 is axially press-fitted, It can prevent harmful effects. Further, since the outer periphery of the shaft 12 of the plunger 12 is in contact with the spool 2, the area of the contact portion can be larger than the conventional shaft cross-sectional area, and the inclination and contact during plunger operation transmission can be increased. There is an effect that it is possible to prevent the wear of the portion.

Embodiment 2. FIG.
FIG. 5 is an axial sectional view showing the vicinity of the magnetic attraction portion of the solenoid valve according to the second embodiment of the present invention, and the same components as those in the first embodiment are denoted by the same reference numerals and redundant description is omitted. .
In this second embodiment, the rubber portion 12c provided on the end surface of the magnetic attraction side of the plunger 12 in the first embodiment is arranged on the plunger facing surface 13b of the boss 13 as a rubber portion 13d. This is the same as the first embodiment. Thus, by forming the rubber portion 13d so as to protrude from the plunger-facing surface 13b of the boss 13 so as to have an inner diameter larger than the outer diameter of the cylindrical portion of the spool 2, when the plunger 12 is operated, The movement of the plunger 12 can be regulated by coming into contact with the rubber portion 13d, and the same effect as that of the first embodiment can be obtained.

Embodiment 3 FIG.
FIG. 6 is an axial sectional view showing the vicinity of the magnetic attraction portion of the electromagnetic valve according to Embodiment 3 of the present invention. The same components as those in Embodiment 1 are given the same reference numerals and redundant description is omitted. .
In the third embodiment, a stopper 14 formed of a nonmagnetic metal plate is installed on the end surface of the plunger 12 on the magnetic attraction side instead of the rubber portion 12c. Is fixed to the plunger outer peripheral surface by means such as press-fitting or welding so that a predetermined positional relationship is established with the plunger 12. The tip end portion of the stopper 14 has a bent portion 14b along the spool 2 in order to prevent deformation due to an impact at the time of contact. According to the third embodiment, there is an effect that the nonmagnetic member can be easily arranged.

Embodiment 4 FIG.
FIGS. 7 and 8 are axial sectional views of a solenoid valve according to Embodiment 4 of the present invention, showing the energization OFF state and the energization ON state, respectively. The duplicate explanation is omitted.
In the fourth embodiment, a non-magnetic member is not provided on one end face (magnetic attraction side) of the plunger 12, the position is restricted when the energization is turned on by the spool 2 and the housing 1, and the operation of the connected plunger 12 is restricted. The one end portion 2a of the spool 2 and the washer 20 installed on the bottom surface of the housing 1 come into contact with each other, thereby restricting the operation of the spool 2. According to this Embodiment 4, the nonmagnetic member installed in the plunger 12 or the boss | hub 13 becomes unnecessary. Further, since the movement amount is regulated by the housing 1 and the spool 2 that form the fluid ports 51 to 57, there is an effect that flow control with higher accuracy is possible.

Embodiment 5. FIG.
FIGS. 9 and 10 are axial sectional views of a solenoid valve according to Embodiment 5 of the present invention, which show the energization OFF state and the energization ON state, respectively. The duplicate explanation is omitted.
In the fifth embodiment, the rubber portion installed on one end surface of the plunger 12 is eliminated, and the plunger position restriction on the energization OFF side is realized by the bottom portion 12e and the end surface of the shaft 11 contacting each other. As with the first embodiment, the energization ON side position restriction is provided with a rubber portion 12c. A through hole 12f is formed at the center of the bottom 12e of the plunger 12, and communicates with a plurality of grooves 12b formed on the end surface of the plunger 12 on the magnetic attraction side. In this structure, the residual air pressure in the space formed by the shaft 11 is released into the solenoid. According to the fifth embodiment, there is an effect that it is possible to regulate the operation on the energization OFF side with an easy structure without installing a nonmagnetic member.

It is an axial sectional view of the solenoid valve by Embodiment 1 of this invention, and is a state part at the time of energization OFF. It is an axial sectional view of the solenoid valve by Embodiment 1 of this invention, and is an electricity supply ON state figure. It is a cross-sectional view which follows the AA line in FIG. It is a cross-sectional view which follows the BB line in FIG. It is the axial direction sectional view which showed the magnetic attraction part periphery of the solenoid valve by Embodiment 2 of this invention. It is the axial sectional view which expanded and showed the magnetic attraction part periphery of the solenoid valve by Embodiment 3 of this invention. It is an axial sectional view of the solenoid valve by Embodiment 4 of this invention, and is a state part at the time of energization OFF. It is an axial sectional view of the solenoid valve by Embodiment 4 of this invention, and is a state part at the time of energization ON. It is an axial sectional view of a solenoid valve according to Embodiment 5 of the present invention, and is a state portion when energization is OFF. It is axial sectional drawing of the solenoid valve by Embodiment 5 of this invention, and is a state part at the time of energization ON.

Explanation of symbols

  1 housing, 2 spool, 3 spring, 4 case, 5 coil body, 6 linear coil, 7 bobbin, 8 coil, 9 terminal, 10 core (fixed iron core), 11 shaft, 12 plunger, 13 boss (fixed iron core).

Claims (7)

  A housing having a plurality of ports; a nonmagnetic spool that is slidably inserted into the housing to open and close the ports; a biasing member that biases the spool in one direction; and one axial end of the spool A case forming a magnetic circuit arranged on the side, a boss fixed in the case and penetrating and supporting the spool, a shaft fixed in the case on the same axis as the spool, and an axis line on the shaft And a magnetic plunger which is supported so as to be movable in a direction and moves by pressing the end face of the spool at the end face on the magnetic attraction side.   2. The solenoid valve according to claim 1, wherein a nonmagnetic member as a stopper is disposed on the outer peripheral end surface or the plunger-facing surface of the boss from the spool contact portion of the plunger.   3. The solenoid valve according to claim 2, wherein the nonmagnetic member as the stopper is formed by baking rubber.   3. The solenoid valve according to claim 2, wherein the nonmagnetic member as the stopper is formed by pressing a nonmagnetic metal plate and fixed to the outer periphery of the end of the plunger on the spool contact side.   The plunger is formed by magnetic metal powder metallurgy or forging, and a plurality of grooves communicating the plunger hole, which is a sliding portion with the shaft, and the solenoid valve internal space are formed in the spool contact portion of the end surface of the plunger on the magnetic attraction side. The solenoid valve according to claim 1, wherein the solenoid valve is provided.   2. The solenoid valve according to claim 1, wherein the operation of the plunger is regulated by contacting the spool and the housing.   2. The solenoid valve according to claim 1, wherein a bottom portion that covers the end face of the magnetic attraction side is formed on the plunger, and the operation of the plunger on the non-magnetic attraction side is regulated by contacting the bottom face of the plunger with the end face of the shaft.

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