JP2006183754A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve improving flow rate controllability, and capable of reducing the number of parts, assembly man hour, and costs by arranging a non-magnetic sleeve bearing without enlarging an air gap and deteriorating magnetic efficiency, preventing applying of large moment due to magnetic side force to a plunger, and stably operating the plunger at all times. <P>SOLUTION: A pair of coaxially opposing fixed cores 7 and 8 is arranged on an axial one end side of a spool 2 slidably inserted into a valve housing 1 and opening and closing ports a-e. The non-magnetic sleeve bearing 10 covering an outer circumference of the plunger 12 is arranged between the fixed cores 7 and 8. An inner diameter contracting part 10a bent in an inner diameter direction between the fixed core 7 of a plunger attraction side and the plunger 12 is integrally formed on an axial one end of the sleeve bearing 10. <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 a means for supporting the plunger, both ends of a plunger rod, which is fixedly penetrated to the axial center of the plunger, are coaxially opposed to a pair of fixed iron cores (the plunger is attracted by magnetic force). Side boss and anti-suction side core) are supported by two thrust bearings, which increases the number of parts, complicates the structure, increases costs, and requires centering accuracy during assembly. Therefore, there was a problem that assembly workability was poor.

  Therefore, as a conventional solenoid valve that solves the above problems, a sleeve bearing made of a non-magnetic member is coaxially connected between a pair of fixed iron cores instead of the thrust bearing, and a plunger can slide within the sleeve bearing. It is known that a plunger rod and a thrust bearing are made unnecessary by inserting them into a shaft to reduce the number of parts, reduce costs, and improve assembly workability (see, for example, Patent Document 1).

  In such a conventional solenoid valve, a sleeve bearing having an axial length shorter than that of the plunger is connected between a pair of fixed iron cores, and the plunger slides over the inner peripheral surface of the fixed iron core in the sleeve bearing. By inserting so as to contact, the outer peripheral surface of the plunger is partially covered by the sleeve bearing. In addition, an elastic stopper (elastic ring member), which is a separate member, is joined to both ends of the plunger so as not to be directly attracted to the fixed iron core by a magnetic attraction force. It is separated from the stationary iron core on the opposite side by the suction force, and is easily separated from the stationary iron core on the suction side by the biasing force of the spring when the power is cut off.

JP 2003-83464 A ([0051] to [0055], FIGS. 1 to 3)

  Since the conventional solenoid valve is configured as described above, the number of parts can be reduced, the cost can be reduced, and the assembly workability can be improved as compared with the case where the plunger is supported by a thrust bearing. The non-magnetic sleeve bearing connected between the opposite ends of the iron core does not cover the entire outer periphery of the plunger, and when the linear coil is energized, the plunger receives a large moment force due to the magnetic side force, which increases the sliding resistance. There has been a problem that the flow rate controllability of the solenoid valve is reduced.

  Furthermore, in the conventional solenoid valve, the stopper of another member must be joined to the end of the plunger so as not to be directly attracted to the fixed iron core as described above, which increases the number of parts and the number of assembling steps and costs. There was a problem of becoming high.

  Furthermore, the sleeve bearing of the conventional solenoid valve is in a state in which an appropriate gap is secured between the pair of fixed iron cores (between the boss portion and the core) in consideration of variations in component dimensions so as not to receive compressive stress. Therefore, when the sleeve bearing is moved or tilted, there is a problem that the operation of the plunger is not stable. Further, the spool of the conventional solenoid valve is in contact with the end face on the suction side of the plunger, and when the plunger is magnetically attracted to the boss portion, the magnetic side force acting on the plunger is increased, and the suction side of the plunger is increased. When the corner contacts the inner peripheral surface of the sleeve bearing and the plunger slide resistance (hook) occurs, the plunger moves easily with the contact part between the suction side end surface and the spool shaft as a fulcrum. Since it was not possible, there was a problem that it was difficult to return from the catch.

  The present invention has been made to solve the above-described problems, and it is possible to dispose a non-magnetic sleeve bearing without reducing the magnetic efficiency without expanding the air gap between the fixed iron core and the plunger. The plunger does not receive a large moment force due to the magnetic side force, the plunger can always be stably operated, the flow rate controllability is improved, and the number of parts and the number of assembly steps are reduced, thereby reducing the cost. The purpose is to obtain a solenoid valve.

  In addition, the present invention provides a solenoid valve that can absorb variations in component dimensions and fix the sleeve bearing so that it does not tilt or move, and can improve the operability and durability of the plunger. For the purpose.

  An electromagnetic valve according to the present invention includes a valve housing having a plurality of ports, a spool that is slidably inserted into the valve housing to open and close the ports, and is disposed coaxially on one end side in the axial direction of the spool. A pair of fixed iron cores facing each other, a non-magnetic sleeve bearing connected between the fixed iron cores, and a plunger slidably inserted into the sleeve bearing and interlocked with the spool. An inner diameter restricting portion that bends in the inner diameter direction between the fixed iron core on the plunger suction side by electromagnetic force and the plunger is integrally formed at one axial end portion of the bearing.

  An electromagnetic valve according to the present invention includes a valve housing having a plurality of ports, a spool that is slidably inserted into the valve housing to open and close the ports, and is disposed coaxially on one end side in the axial direction of the spool. A pair of fixed iron cores facing each other, a non-magnetic sleeve bearing connected between the fixed iron cores, and a plunger slidably inserted into the sleeve bearing and interlocked with the spool. A spacer having an elastic function is disposed at at least one end of the bearing, and the sleeve bearing is fixed by sandwiching the spacer between the end of the sleeve bearing and the fixed iron core.

  According to this invention, an inner diameter restricting portion that bends in the inner diameter direction between the fixed iron core on the plunger suction side and the plunger is integrally formed at one end in the axial direction of the sleeve bearing connected and disposed between the pair of fixed iron cores. Because it is configured, the inner diameter throttle part of the sleeve bearing can function as a stopper for the plunger during magnetic attraction, so there is no need to join a stopper of another member to the fixed iron core or plunger by press-fitting or bonding, There is an effect that the number of parts and the number of assembly steps can be reduced and the cost can be reduced. In addition, as described above, the non-magnetic sleeve bearing having the inner diameter narrowed portion at one end can be easily formed by press working and can be thinned, so that the air gap is not enlarged and the magnetic efficiency is improved. The sleeve bearing can be disposed between a pair of fixed iron cores without being lowered, and therefore, the magnetic side force acting on the plunger can be directly received by the sleeve bearing of the air gap portion. This has the effect of reducing the momentum force generated in the plunger and reducing the sliding resistance of the plunger.

  In addition, at the full stroke position of the plunger due to magnetic attraction, the end surface of the plunger is in contact with the inner diameter throttle of the non-magnetic sleeve bearing and does not contact the fixed core on the plunger suction side. Sometimes, the plunger can be quickly responsive to the initial position by the urging force of the spool.

  According to the present invention, a spacer having an elastic function is disposed at least at one end of a sleeve bearing connected between a pair of fixed iron cores, and the spacer is sandwiched between the end portion of the sleeve bearing and the fixed iron core. Since the sleeve bearing is fixed, it is possible to fix the sleeve bearing by absorbing the variation in component dimensions during the assembly of the solenoid valve by the elastic function of the spacer. There is an effect that the movement and the durability of the plunger can be improved by suppressing the movement and the like. Further, the sleeve bearing can be easily assembled and set to a pair of fixed iron cores without applying means such as press-fitting and plastic deformation, and the number of assembling steps can be reduced and the cost can be reduced. is there. Further, the spacer can also function as a stopper for the plunger, so that it is not necessary to join a stopper of a separate member to the plunger, the number of parts and the number of parts assembling steps can be reduced, and contact during plunger operation is possible. There is an effect that the sound can be reduced.

Embodiment 1 FIG.
1 is a cross-sectional view showing a solenoid valve according to Embodiment 1 of the present invention, FIG. 2 (A) is an enlarged cross-sectional view of a main part in a state where the plunger in FIG. 1 is in an initial position, and FIG. It is a principal part expanded sectional view in the state in which the plunger in 1 exists in a full stroke position.
The solenoid valve shown in FIG. 1 has a valve housing 1 having a plurality of ports a to e for fluid passage connection, and is inserted into the valve housing 1 so as to be slidable in the axial direction to open and close the ports a to e. A nonmagnetic spool 2, a spring 3 that urges the spool 2 in one axial direction, and a cylindrical yoke 4 connected to one axial end of the valve housing 1 are provided. Although a cylindrical yoke is described here, a hexagonal columnar yoke, a yoke formed by bending a sheet metal into a U-shape, or the like can also be used. A coil bobbin 5 around which a linear coil 6 is wound is fitted in the yoke 4. A pair of fixed iron cores 7 and 8 that are coaxially spaced apart from each other on one end side in the axial direction of the spool 2 are fitted inside the both ends of the coil bobbin 5. Further, a resin member 9 in which a terminal 9 a electrically connected to the linear coil 6 is molded is fitted to an end portion of the yoke 4 opposite to the valve housing 1.

  In the fixed iron cores 7 and 8, the fixed iron core (hereinafter referred to as the boss portion) 7 on the plunger suction side by magnetic force is made of a cylindrical magnetic body having an annular inner step portion 7a. On the other hand, the fixed iron core (hereinafter referred to as a core) 8 on the side opposite to the plunger is made of a magnetic body having a cylindrical portion 8a that is open on the opposite end side to the boss portion 7, and is formed in the inner portion of the cylindrical portion 8a. The elastic spacer 11 is fitted. The elastic spacer 11 is made of, for example, fluorine-based rubber or a leaf spring. A sleeve bearing 10 straddling the inner peripheral surface of the boss 7 and the core 8 is coaxially connected. The sleeve bearing 10 is made of a cylindrical nonmagnetic material (for example, nonmagnetic stainless steel) formed to have substantially the same outer diameter as the inner diameter of each of the boss 7 and the core 8. One end of the sleeve bearing 10 in the axial direction is integrally formed with an inner diameter restricting portion 10a that is bent substantially perpendicularly to the inner diameter direction of the sleeve bearing 10.

  The sleeve bearing 10 has an end on the inner diameter throttle portion 10a side fitted into the boss portion 7 so that the inner diameter throttle portion 10a is brought into contact with the inner step portion 7a of the boss portion 7 and the inner diameter throttle portion 10a. The mounting structure is such that the end opposite to the portion 10 a is fitted into the cylindrical portion 8 a of the core 8 and pressed against the elastic spacer 11. A plunger 12 interlocking with the spool 2 is slidably inserted into the sleeve bearing 10.

  Here, the sleeve bearing 10 is formed to be longer in the axial direction than the plunger 12 and is fitted to the inner peripheral surfaces of the boss portion 7 and the core 8 as described above. For this reason, the sleeve bearing 10 covers the entire outer periphery of the plunger 12. Further, as described above, the inner diameter restricting portion 10a of the sleeve bearing 10 that is in contact with the inner step portion 7a of the boss portion 7 blocks between the suction side end of the plunger 12 and the inner step portion 7a of the boss portion 7. ing. For this reason, at the full stroke position by the magnetic attraction force of the plunger 12, the suction side end of the plunger 12 comes into contact with the inner diameter restricting portion 10a. Therefore, the inner diameter throttle portion 10a of the sleeve bearing 10 serves as a stopper for the suction side end of the plunger 12.

  On the other hand, the plunger 12 has recesses 12a and 12b formed at both ends thereof, and an axial through hole (air or oil flow passage) 12c communicating with the recesses 12a and 12b. A tapered surface 12d is formed on the outer periphery of the end of the plunger 12 on the suction side. The spool shaft 2 a is always in contact with the inner end surface of the suction side recess 12 a of the plunger 12 by the urging force of the spring 3.

  Here, as shown in FIG. 1, components such as a coil bobbin 5 around which a linear coil 6 is wound, a boss 7, a core 8, and a sleeve bearing 10 incorporating a plunger 12 are assembled and set inside the yoke 4. In this state, when the both ends 4a and 4b of the yoke 4 are crimped to the flange 1a of the valve housing 1 and the outer peripheral edge of the resin member 9, the inner diameter restricting portion 10a of the sleeve bearing 10 is bossed by the caulking force. The elastic spacer 11 is sandwiched between the end of the sleeve bearing 10 opposite to the inner diameter restricting portion 10 a and the inner wall of the cylindrical portion 8 a of the core 8 while being pressed against the inner step portion 7 a of the portion 7. In this state, the sleeve bearing 10 is fixed.

Next, the operation will be described.
When the linear coil 6 is not energized, the plunger 12 in the sleeve bearing 10 is held in the state shown in FIG. 2A in which the end on the opposite side to the elastic spacer 11 is pressed against the elastic spacer 11 by the urging force of the spring 3. When the linear coil 6 is energized in this state, the plunger 12 moves in the sleeve bearing 10 in a direction against the urging force of the spring 3 by the magnetic attractive force generated on the boss portion 7 side, and the spool 2 is moved. Push. Thereby, the ports a to e of the valve housing 1 are switched to a predetermined fluid flow path by the spool 2. At the full stroke position of the plunger 12 by the magnetic attraction force, as shown in FIG. 2 (B), the end of the plunger 12 on the attraction side contacts the inner diameter restricting portion 10a of the sleeve bearing 10 made of a nonmagnetic material. It is kept in contact. Thus, at the full stroke position of the plunger 12, the suction side end portion of the plunger 12 and the inner step portion 7 a of the boss portion 7 are blocked by the inner diameter restricting portion 10 a of the nonmagnetic sleeve bearing 10. When the energization of the linear coil 6 is interrupted, the plunger 12 can be swiftly responded to the initial position shown in FIG.

  According to the first embodiment described above, a non-magnetic sleeve that is connected and disposed between the boss portion 7 and the core 8 that are coaxially opposed to each other on one end side of the spool shaft 2a and covers the entire outer periphery of the plunger 12. Since the annular inner diameter throttle portion 10a that allows the axial movement of the spool shaft 2a is integrally formed at the suction side end portion of the plunger 12 in the bearing 10, the inner diameter throttle portion 10a of the sleeve bearing 10 is magnetically attracted. It can function as a stopper for the plunger 12 at the time. This eliminates the need for separate stopper parts that have been conventionally joined to the ends of the boss 7 and the plunger 12 by press-fitting or bonding, thereby reducing the number of parts and the number of assembling steps and reducing costs. There is an effect that can be.

  Further, as described above, the non-magnetic sleeve bearing 10 having the inner diameter narrowed portion 10a at one end can be easily formed by press working and can be thinned. There is an effect that the sleeve bearing 10 can be fitted and disposed across the boss portion 7 and the cylindrical portion 8a of the core 8 without reducing the efficiency. Further, since the sleeve bearing 10 is formed longer in the axial direction than the plunger 12 and covers the entire outer periphery of the plunger 12, the sleeve bearing 10 directly receives the side force when the plunger 12 is magnetically attracted. Therefore, there is an effect that the moment force acting on the plunger 12 can be reduced and the slidability of the plunger 12 is improved.

  Furthermore, both end portions of the sleeve bearing 10 are fitted and supported on the respective inner peripheral surfaces of the boss portion 7 and the cylindrical portion 8a of the core 8, and in this state, due to the caulking force of both end portions 4a and 4b of the yoke 4, the sleeve Since the bearing 10 is pressed and fixed to the elastic spacer 11, variations in the component dimensions of the sleeve bearing 10, the boss portion 7, and the core 8 can be absorbed by the elastic spacer 11, thereby making the sleeve bearing 10 large. There is an effect that it is possible to fix so as not to generate compressive stress. Further, the elastic spacer 11 can regulate the inclination, movement, etc. of the plunger 12 whose one end in the axial direction is pressed against the elastic spacer 11, so that the operation resistance of the plunger 12 is increased (the operation current is increased) and the operation durability is increased. There is an effect that it is possible to avoid a decrease in the above.

  Further, the sleeve bearing 10 can be easily fixed only by the caulking force at both end portions 4a and 4b of the yoke 4 as described above without requiring press-fitting, plastic deformation or the like with respect to the boss portion 7 and the core 8. There is an effect that the processing accuracy of parts and the assembly process can be omitted. Further, since the elastic spacer 11 also functions as a stopper for the plunger 12 that is moved by the urging force of the spring 3, there is an effect that the elastic spacer 11 can absorb the impact sound when the plunger 12 abuts. Further, since the plunger 12 is provided with through holes 12c communicating with the recesses 12a and 12b at both ends, the operation resistance of the plunger 12 can be greatly reduced, and the plunger 12 can be operated smoothly at all times. There is.

Embodiment 2. FIG.
FIG. 3 is a cross-sectional view showing a main part of an electromagnetic valve according to Embodiment 2 of the present invention. The same or corresponding parts as those in FIGS.
In the second embodiment, the sleeve bearing 10 made of a straight pipe-like nonmagnetic material without the inner diameter throttle portion 10a in the first embodiment is applied, and both the inside of the boss portion 7 and the inside of the cylindrical portion 8a of the core 8 are applied. Further, elastic spacers 11A and 11B made of, for example, fluorine rubber or leaf springs are accommodated and arranged, and both end portions of the sleeve bearing 10 are pressed and fixed to these elastic spacers 11A and 11B. That is, the elastic spacers 11A and 11B and both ends of the sleeve bearing 10 are sequentially fitted into the boss 7 and the cylindrical portion 8a of the core 8, and in this state, the both ends 4a and 4b of the yoke 4 in FIG. By attaching one elastic spacer 11A between the inner step portion 7a of the boss portion 7 and one end portion of the sleeve bearing 10, the inner back wall of the cylindrical portion 8a of the core 8 and the other end of the sleeve bearing 10 are provided. The sleeve bearing 10 is fixed by sandwiching the other elastic spacer 11B between the two portions.

  According to the second embodiment configured as described above, variations in component dimensions during assembly of the solenoid valve are absorbed by the elastic functions of the elastic spacers 11A and 11B that hold the sleeve bearing 10 in the state where both ends thereof are bitten. Thus, the sleeve bearing 10 can be fixed, and the operation and durability of the plunger 12 can be improved by suppressing the inclination and movement of the sleeve bearing 10. Further, the sleeve bearing 10 can be easily assembled and set without applying means such as press fitting or plastic deformation to the boss portion 7 and the core 8, and the number of assembling steps can be reduced. This has the effect of reducing costs. Furthermore, the elastic spacers 11A and 11B can also function as a stopper for the plunger 12, so that it is not necessary to join a stopper for a separate member of the plunger 12, and the number of parts and parts assembly man-hours can be reduced. There is an effect that the contact noise at the time of the plunger operation can be reduced.

Embodiment 3 FIG.
FIG. 4 is a cross-sectional view showing the main part of a solenoid valve according to Embodiment 3 of the present invention. The same parts as those in FIGS.
In the third embodiment, the sleeve bearing 10 and the elastic spacer 11 in the first embodiment are reversed and connected between the boss portion 7 and the core 8. That is, the inner diameter throttle part 10a side of the sleeve bearing 10 is fitted into the cylindrical part 8a of the core 8, and the elastic spacer 11 is fitted into the boss part 7. In this state, what is the inner diameter throttle part 10a of the sleeve bearing 10? The end on the opposite side (plunger suction side) is fitted into the boss 7. As in the case of the second embodiment, the end portion on the boss portion 7 side of the sleeve bearing 10 is pressed against the elastic spacer 11 by the caulking force of both end portions 4a and 4b of the yoke 4 in FIG. The sleeve bearing 10 is fixed between the boss portion 7 and the core 8.

  Also in the third embodiment configured as described above, the single elastic spacer 11 fitted in the boss portion 7 absorbs the variation in the component dimensions at the time of assembling the electromagnetic valve so that the sleeve bearing 10 is connected to the boss portion 7. It can be fixed between the core 8 and other effects similar to those of the second embodiment can be obtained.

Embodiment 4 FIG.
5 is a cross-sectional view showing the main part of a solenoid valve according to Embodiment 4 of the present invention.
In the fourth embodiment, the plunger 12 in the first embodiment is formed into a bottomed cylindrical shape (cup shape), and a through hole (air or oil flow passage) 12e is provided at the bottom. The plunger 12 is slidably inserted into the sleeve bearing 10 with the open end of the plunger 12 facing the boss portion 7, and the spool shaft 2 a is inserted into the center of the plunger 12. The end of the shaft 2a is brought into contact with the inner bottom surface of the plunger 12 by the urging force of the spring 3 (see FIG. 1). Here, the inner diameter of the cylindrical portion of the plunger 12 is set larger than the outer diameter of the spool shaft 2a, and a gap is formed between the outer peripheral surface of the spool shaft 2a and the inner peripheral surface of the plunger 12. The through hole (air or oil flow passage) 12e communicates with the gap. Other configurations are the same as those in the first embodiment.

According to the fourth embodiment configured as described above, the magnetic attraction side (the boss portion 7 side) of the plunger 12 is arbitrarily set within the set clearance with the contact portion between the spool shaft 2a and the inner bottom surface of the plunger 12 as a fulcrum. For this reason, even if the suction side corner of the plunger 12 and the sleeve bearing 10 are caught by the magnetic side force during the operation of the plunger 12, the plunger 12 can be easily returned. The sliding resistance (hanging) of the plunger 12 can be suppressed, and there is an effect that the operation resistance of the plunger 12 can be reduced (operation current reduction) and the operation durability can be improved. The plunger 12 according to the fourth embodiment is also applicable to the electromagnetic valve according to the second and third embodiments.
In the first to fourth embodiments, the plunger 12 is provided with through holes (air or oil flow passages) 12c, 12e in the axial direction. Instead of the through holes 12c, 12e, the plunger 12 An air or oil flow passage may be provided by providing grooves on the surface in the axial direction.

Embodiment 5. FIG.
6A is an end view of the sleeve bearing of the solenoid valve according to Embodiment 5 of the present invention, and FIG. 6B is an axial sectional view of the sleeve bearing of FIG. 6A.
In the fifth embodiment, the inner diameter restricting portion 10a formed at one end of the sleeve bearing 10 in the first and fourth embodiments at a substantially right angle in the inner diameter direction is formed inside the sleeve bearing 10 in the axial direction. A plurality of projecting radial ribs 10b projecting from the radial rib are integrally formed, and end portions on the magnetic attraction side of the plunger 12 are brought into contact with these axial projecting parts 10b.

  According to the fifth embodiment configured as described above, the plunger 12 and the boss 7 at the full stroke position are brought into contact with the axial protrusion 10b of the sleeve bearing 10 at the full stroke position when the plunger 12 is magnetically attracted. The distance between the inner step portion 7a (see FIGS. 1 and 2) can be increased (the plunger 12 is greatly separated from the inner step portion 7a of the boss portion 7 at the full stroke position). There is an effect that it is possible to prevent an excessive magnetic attractive force from acting on the plunger 12 from the boss portion 7.

Embodiment 6 FIG.
7A is an end view of the sleeve bearing of the solenoid valve according to Embodiment 6 of the present invention, and FIG. 7B is an axial sectional view of the sleeve bearing of FIG. 7A.
In the sixth embodiment, the inner diameter restricting portion 10a of the sleeve bearing 10 in the first and fourth embodiments is replaced with the radial rib-shaped axial projecting portion 10b in the fifth embodiment in a semicircular section. A plurality of arc-shaped projecting portions 10c having an arc shape are integrally formed, and end portions on the magnetic attraction side of the plunger 12 are brought into contact with these axial projecting portions 10c. Therefore, in the case of the sixth embodiment, the same effect as in the fifth embodiment can be obtained.

Embodiment 7 FIG.
8A is an end view of the sleeve bearing of the solenoid valve according to Embodiment 7 of the present invention, and FIG. 8B is an axial sectional view of the sleeve bearing of FIG. 8A.
In the seventh embodiment, the corner portion of the sleeve bearing 10 of the first embodiment and the fourth embodiment is locally indented and inclined to the inside of the corner portion by locally pressing and molding. A plurality of axial protrusions 10d are formed, and the end portions on the magnetic attraction side of the plunger 12 are brought into contact with these axial protrusions 10d. Therefore, in the case of the seventh embodiment, the same effect as in the fifth embodiment can be obtained.

Embodiment 8 FIG.
FIG. 9A is an end view of a sleeve bearing of an electromagnetic valve according to Embodiment 8 of the present invention, and FIG. 9B is an axial sectional view of the sleeve bearing of FIG. 9A.
In the eighth embodiment, a semicircular cross section is used instead of the radial rib-shaped axial protruding portion 10b of the fifth embodiment instead of the inner diameter restricting portion 10a of the sleeve bearing 10 in the first and fourth embodiments. A plurality of arc-shaped projecting portions 10e having an arc shape are integrally formed on the outer surface of the inner diameter restricting portion 10a, and the end portion on the magnetic attraction side of the plunger 12 is brought into contact with a portion other than the projecting portions 10e in the axial direction. Is. Therefore, in the case of the eighth embodiment, the same effect as in the fifth embodiment can be obtained.

It is sectional drawing which shows the solenoid valve by Embodiment 1 of this invention. 2A is an enlarged cross-sectional view of the main part when the plunger in FIG. 1 is in the initial position, and FIG. 2B is an enlarged cross-sectional view of the main part when the plunger in FIG. 1 is at the full stroke position. It is. It is sectional drawing which shows the principal part of the solenoid valve by Embodiment 2 of this invention. It is sectional drawing which shows the principal part of the solenoid valve by Embodiment 3 of this invention. It is sectional drawing which shows the principal part of the solenoid valve by Embodiment 4 of this invention. 6A is an end view showing a sleeve bearing of a solenoid valve according to Embodiment 5 of the present invention, and FIG. 6B is an axial sectional view of the sleeve bearing of FIG. 6A. FIG. 7A is an end view showing a sleeve bearing of an electromagnetic valve according to Embodiment 6 of the present invention, and FIG. 7B is an axial sectional view of the sleeve bearing of FIG. 7A. FIG. 8A is an end view showing a sleeve bearing of an electromagnetic valve according to Embodiment 7 of the present invention, and FIG. 8B is an axial sectional view of the sleeve bearing of FIG. 8A. 9A is an end view showing a sleeve bearing of an electromagnetic valve according to Embodiment 8 of the present invention, and FIG. 9B is an axial sectional view of the sleeve bearing of FIG. 9A.

Explanation of symbols

  1 Valve housing, 1a flange, 2 spool, 2a spool shaft, 3 spring, 4 yoke, 4a, 4b crimping on both ends, 5 coil bobbin, 6 linear coil, 7 boss (fixed iron core), 7a inner step, 8 core ( Fixed iron core), 8a cylindrical portion, 9 resin member, 9a terminal, 10 sleeve bearing, 10a inner diameter restricting portion, 10b to 10e axial protruding portion, 11, 11A, 11B spacer, 12 plunger, 12a, 12b concave portion, 12c, 12e Through hole (air or oil flow passage), 12d tapered surface, a to e ports.

Claims (8)

A valve housing having a plurality of ports; a spool that is slidably inserted into the valve housing to open and close the ports; and a pair of fixed iron cores that are disposed on one axial end side of the spool and are coaxially opposed to each other. In a solenoid valve comprising a non-magnetic sleeve bearing connected between these fixed iron cores, and a plunger slidably inserted into the sleeve bearing and interlocked with the spool,
The solenoid valve according to claim 1, wherein an inner diameter restricting portion that is bent in an inner diameter direction is integrally formed between one end portion in the axial direction of the sleeve bearing and a fixed iron core on the plunger suction side by electromagnetic force and the plunger.   2. The solenoid valve according to claim 1, wherein the sleeve bearing is formed longer in the axial direction than the plunger and covers the entire outer periphery of the plunger.   The solenoid valve according to claim 1 or 2, wherein the sleeve bearing is fitted over the inner peripheral surfaces of the pair of fixed iron cores.   The axially narrowed portion of the sleeve bearing is formed with an axially projecting portion that projects inward in the axial direction of the sleeve bearing from the narrowed inner diameter portion and abuts the end portion on the magnetic attraction side of the plunger. The electromagnetic valve according to any one of claims 1 to 3.   Inside the sleeve bearing, a plunger with a bottomed cylindrical shape and an air vent hole at the bottom is slidably inserted with its open end as the magnetic attraction side, and the spool shaft is coaxial with the plunger. The solenoid valve according to claim 1, wherein the end of the spool shaft is in contact with the inner bottom surface of the plunger.   6. The plunger according to any one of claims 1 to 5, wherein the plunger is provided with at least one through passage which communicates with the front and rear of the plunger in a position excluding the spool contact range. The solenoid valve described. A valve housing having a plurality of ports; a spool that is slidably inserted into the valve housing to open and close the ports; and a pair of fixed iron cores that are disposed on one axial end side of the spool and are coaxially opposed to each other. In a solenoid valve comprising a non-magnetic sleeve bearing connected between these fixed iron cores, and a plunger slidably inserted into the sleeve bearing and interlocked with the spool,
An electromagnetic valve characterized in that a spacer having an elastic function is disposed at at least one end of the sleeve bearing, and the sleeve bearing is fixed by sandwiching the spacer between the end of the sleeve bearing and the fixed iron core.   It is arranged on one end side of the valve housing in the axial direction, and a linear coil, a pair of fixed iron cores, and a sleeve bearing that connects between the fixed iron cores are built in. The solenoid valve according to claim 6, wherein at least one end of the sleeve bearing is pressed against a spacer to fix the sleeve bearing coaxially between the pair of fixed iron cores.

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