JP2000097361A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve to realize an improvement in assembly ability at a low cost. SOLUTION: A nozzle 12 and a solenoid 13 are contained in the casing 11 of a solenoid valve 1, and a plunger 18 having a rod 19 is contained in the internal space 16 of the bobbin 14 of the solenoid 13. A magnetic passage constituting member 21 is arranged at the upper end part of the bobbin 14 and a core 22 is fitted in and internally of the lower end part thereof. A magnetic passage constituting member 21 comprises a cylindrical yoke 31; and an internally fitting-in member 32 fitted in and internally of the yoke 31. The internally fitting-in member 32 comprises an internally fitting-in part 33; and a flange part 35 making surface contact with the upper end face 34 of the bobbin 14. The bobbin 14 is molded by using resin integrally with the yoke 31 and the core 2, and a filling part 36 filled with resin is formed between the yoke 31 and the core 22. A mounting groove 37 to surround the yoke 31 is formed in the upper end surface 34 of the bobbin 14, and an O-ring 38 is disposed in the mounting groove 37. The O-ring 38 is forced into pressure contact by the flange part 35 of the internally fitting-in member 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve used for a hydraulic circuit in an automatic transmission of an automobile, for example.

[0002]

2. Description of the Related Art Conventionally, an electromagnetic valve 101 as shown in FIG. 3 has been used in a hydraulic circuit in an automatic transmission of an automobile or the like (see Japanese Utility Model Laid-Open No. 7-27113).

The solenoid valve 101 includes a solenoid 107 including a bobbin 105 and a coil 106 wound around the bobbin 105, a core 108 as a magnetic path constituting member fitted inside a tip end of the solenoid 107, and the solenoid 10.
7 is a yoke 109 which is a magnetic path constituting member fitted inside the base end of the yoke 109.
And The core 108 includes a nozzle portion 112 inserted into a mounting hole 111 of a hydraulic circuit, a disk portion 113 abutting on a distal end surface of the solenoid 107, and an inner fitting portion 114 fitted inside the solenoid 107. Are integrally formed, and the solenoid 107 is provided on the core 108.
An insertion hole 117 through which a rod 116 extending from the tip of a plunger 115 housed therein is inserted is provided. The inner fitting portion 114 of the core 108 has a concave portion 118 into which the tip of the plunger 115 is movably fitted. The insertion hole 117 has a rod 116 of the plunger 115. Is provided with a front end bearing 119 that supports the front end.

[0004] The yoke 109 is connected to the solenoid 10.
7, a base 122 that abuts on a base end face of the solenoid 107,
An extension portion 123 extending inward is formed integrally with the extension portion 123, and the extension portion 123 is provided with a housing hole 124 for movably housing the plunger 115. An insertion hole 125 into which the rod 116 extending from the base end of the plunger 115 is inserted is provided at a base end of the extension portion 123.
6 is provided.

The bobbin 1 of the solenoid 107
In FIG. 05, grooves 131 and 132 are formed on the distal end surface and the proximal end surface.
Are formed, and the O-rings 133, 133 are fitted in the two concave grooves 132, 131. Thereby, the core 108 and the yoke 10 are attached to the solenoid 107.
When the core 9 is fixed to the core 10, the O-ring 133 is fitted in the groove 131 at the tip of the bobbin 105.
8 and the O-ring 133 fitted in the concave groove 132 at the base end of the bobbin 105 comes into close contact with the base 122 of the yoke 109 and flows into the internal space 141 of the solenoid 107. It is configured such that the drained oil is prevented from flowing out. Thereby, the flow of oil in the internal space 141 in which the plunger 115 is accommodated is prevented, and contaminants such as iron powder mixed in oil can be prevented from entering the internal space 141, Plunger 1 due to contamination
15 is configured to be able to prevent adverse effects.

FIG. 4 is a view showing another solenoid valve 201, and the suction unit 20 sucked by the solenoid 107 is shown in FIG.
A diaphragm 203 for preventing the inflow of oil is provided at the tip of 2. Thus, the suction unit 202 can be prevented from being adversely affected by contamination mixed in the oil.

[0007]

However, in the former solenoid valve 101, the tip of the inner fitting portion 114 of the core 108 fitted inside the solenoid 107 and the tip of the extending portion 123 of the yoke 109 are different from each other. A gap is formed between the solenoid 107 and the solenoid 107 through the gap.
When the oil in the internal space 141 flows out, the contamination mixed in the oil easily enters the internal space 141. For this reason, it is necessary to ensure the sealing property between the front end surface and the base end surface of the bobbin 105 of the solenoid 107, and the O-ring 13 is provided on both the front end and the base end of the bobbin 105.
3,133 had to be provided. This allows
The number of assembling man-hours increased, which was a factor of deteriorating the assemblability.

In the latter solenoid valve 201, the diaphragm 203 provided at the end of the suction portion 202 prevents the oil from flowing into the solenoid 107, thereby preventing the oil from contaminating the oil. Although it is possible to prevent the suction unit 202 from being adversely affected, the cost is increased because the expensive diaphragm 203 is used.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an electromagnetic valve capable of improving the assemblability without increasing the cost.

[0010]

According to a first aspect of the present invention, there is provided a solenoid valve which is inserted from one end of a bobbin of a solenoid into an internal space of the bobbin, and is connected to one end of the internal space. A magnetic path constituting member that closes the hole, a core that is fitted inside the other end of the bobbin, and has an insertion hole in the center, and an insertion bar that is movably provided in the internal space and that passes through the insertion hole. With a plunger provided with
In a solenoid valve having a gap provided between the magnetic path constituting member and the core, the magnetic path constituting member is fitted in a cylindrical yoke in which the plunger is movably fitted, and is fitted in the yoke. An inner fitting member having a flange portion protruding laterally from an outer peripheral portion of the inner fitting portion and being in contact with one end surface of the bobbin, while the bobbin is formed by the yoke and the core. Together with a resin to form a filling portion filled with the resin in the gap between the yoke and the core, and between the one end surface of the bobbin and the flange portion of the inner fitting member, A seal member surrounding the yoke was provided.

That is, the magnetic path component inserted from one end of the bobbin of the solenoid into the internal space of the bobbin is:
The bobbin is formed of a cylindrical yoke and an inner fitting member fitted inside the yoke, and the bobbin is integrally molded with a resin together with a core fitted inside the other end of the bobbin. A filling portion formed by filling the resin is formed in a gap between the yoke and the core. This ensures a sealed state in the gap between the yoke and the core constituting the magnetic path constituting member, so that the communication path communicating with the outside via the internal space of the bobbin in which the plunger is accommodated is It is limited to only a gap formed between the yoke integrally formed on the bobbin and an inner fitting member internally fitted in the yoke.

The inner fitting member has an inner fitting portion fitted into the yoke, and a flange projecting laterally from an outer peripheral portion of the inner fitting portion and in contact with one end surface of the bobbin. A seal member surrounding the yoke is provided between the one end surface of the bobbin and the flange of the inner fitting member. Therefore, the airtightness between the one end surface of the bobbin and the flange portion of the inner fitting member is ensured, so that the yoke integrally formed with the bobbin and the inner fitting member internally fitted to the yoke are provided. Is also prevented from flowing through the communication path.

[0013] In the solenoid valve of the second aspect, a bearing for supporting the insertion bar of the plunger is provided in the insertion hole of the core.

That is, since the bearing for supporting the insertion bar provided on the plunger is provided in the insertion hole of the core formed integrally with the bobbin for movably housing the plunger, the bearing is integrated with the bobbin. Management of the coaxiality between the formed yoke and the bearing is performed during bobbin molding.

Further, in the solenoid valve according to the third aspect, the core is provided with an immersion portion immersed in the inner wall surface of the bobbin, and the core projects from the immersion portion toward the center and is provided with the insertion hole. The inner diameter of the recessed portion was made to match the inner diameter of the yoke and the filling portion.

Accordingly, the inner wall surface of the bobbin is formed without forming irregularities on the inner mold that forms the inner wall surface of the bobbin.

In addition, in the solenoid valve according to a fourth aspect of the present invention, the step portion of the core is provided with a communication hole communicating the internal space on one side and the other side with the core as a boundary.

[0018] This allows the internal space on one side and the other side of the core to communicate with each other through the communication hole, thereby facilitating discharge of the oil flowing into the internal space.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a normally open solenoid valve 1 according to the present embodiment. The solenoid valve 1 is used in a hydraulic circuit in an automatic transmission of an automobile as in the conventional example.

A nozzle 12 that projects downward and is inserted into an insertion hole provided in a block of a hydraulic circuit, inside a cylindrical casing 11 that constitutes the solenoid valve 1,
2 and the solenoid 13 disposed on the
The solenoid 13 includes a bobbin 14 and a coil 15 wound around the bobbin 14. A plunger 18 having a vertical groove 17 formed in a side portion is movably accommodated in an internal space 16 of the bobbin 14, and the plunger 18 has an insertion bar extending to an upper end side and a lower end side. Is provided. Bobbin 1
A magnetic path constituting member 21 that forms a magnetic circuit together with the casing 11 is provided at an upper end of the bobbin 4, and a core 22 is fitted inside a lower end of the bobbin 14.

The magnetic path constituting member 21 is composed of a cylindrical yoke 31 into which the plunger 18 is movably fitted, and an inner fitting member 32 fitted into the yoke 31. The fitting member 32 includes an inner fitting portion 33 that is fitted inside the yoke 31, and a flange portion 35 that protrudes laterally from an outer peripheral portion of the inner fitting portion 33 and is in contact with the upper end surface 34 of the bobbin 14.
And are formed integrally. The bobbin 14 is formed integrally with the yoke 31 and the core 22 by a resin, and a filling portion 36 filled with the resin is provided in a gap set between the yoke 31 and the core 22. It is formed so as to maintain the gap between the yoke 31 and the core 22. An annular mounting groove 37 is formed on the upper end face 34 of the bobbin 14 along the outer peripheral portion of the yoke 31, and an O-ring 38 as a sealing member is provided in the mounting groove 37. . And, the inner fitting member 32 is connected to the casing 11.
The O-ring 38 provided on the upper end surface 34 of the bobbin 14 is fixed to the flange 35 of the inner fitting member 32 by caulking the upper edge of the flange 35. It is configured to be pressed against.

The core 22 includes an immersion portion 42 immersed in the inner wall surface 41 of the bobbin 14 and a step portion 44 protruding from the immersion portion 42 toward the center line 43 of the solenoid valve 1. An insertion hole 45 is provided in the center of the portion 44, and the periphery of the insertion hole 45 forms a suction surface 46 of the plunger 18. A rod 19 extending downward from the plunger 18 is inserted into the insertion hole 45, and a lower bearing 47 that supports the rod 19 from the periphery is fixed in a state of being fitted inside. Further, the inner fitting portion 33 of the inner fitting member 32
A concave portion 48 is provided at the center of the rod, and a rod 19 extending upward from the plunger 18 is inserted into the concave portion 48, and an upper bearing 49 for supporting the rod 19 from the periphery is provided. , And is fixed in an internally fitted state. Thus, the rod 19 extending upward and downward from the plunger 18 is connected to the upper bearing 49 and the lower bearing 47.
By being supported by the actuator, it is configured such that the lateral movement during operation is prevented.

The inner diameter H1 of the core 22 at the immersion portion 42 is set so as to coincide with the inner diameter H2 of the yoke 31 and the inner diameter H3 of the filling portion 36, and the plunger 18 comes into sliding contact. The inner wall surface 41 of the bobbin 14 is configured to have a smooth curved surface without unevenness. At the lower end of the core 22, a bracket 51 for fixing the solenoid valve 1 is integrally formed so as to protrude leftward, and the solenoid 1
A terminal portion 53 from which a terminal 52 connected to the third coil 15 extends is integrally formed with the terminal portion 53 protruding rightward.

The step portion 44 of the core 22 has an internal space 16 on the upper side of the core 22,
There are provided communication holes 61, 61 communicating with the lower space, and the internal space 16 defines the communication holes 61, 61.
Through this, it communicates with a valve chamber 62 formed in the nozzle 12 below the core 22.

That is, the valve chamber 62 into which the rod 19 extending from the plunger 18 is inserted into the nozzle 12 and the inflow extending downward from the valve chamber 62 along the center line 43. A passage 65 and an outflow passage 66 extending rightward from the valve chamber 62 are formed. A small-diameter hole 67 having a small inner diameter is formed in the inflow passage 66 in the vicinity of the valve chamber 62, and the rod 19 is detachably seated around the small-diameter hole 67 on the valve chamber 62 side. The valve seat 68 is constituted.

As a result, the rod 19 receives the pressure of the oil flowing into the valve chamber 62 from the inflow passage 65, and the rod 19 and the plunger 18 are pushed upward as shown by the arrow A in FIG. When the small-diameter hole 67 is opened, the oil from the inflow passage 65 is discharged from the outflow passage 66 through the valve chamber 62. When the solenoid 13 is energized, the plunger 18 is attracted to the suction surface 46 of the core 22 as shown by the arrow B in FIG. It is closed by the rod 19 and is configured to prevent the inflow of oil from the inflow path 65 and the outflow of oil from the outflow path 66.

In the present embodiment according to the above configuration, the magnetic path constituting member 21 inserted into the internal space 16 of the bobbin 14 from the upper end of the bobbin 14 of the solenoid 13 is
The bobbin 14 includes a cylindrical yoke 31 and an inner fitting member 32 fitted inside the yoke 31. The bobbin 14 is provided together with the core 22 fitted inside the other end of the bobbin 14. The yoke 3 is integrally formed of resin.
In the gap between the core 1 and the core 22, a filling portion 36 formed by filling the resin is formed. Thereby, the yoke 31 and the core 2 constituting the magnetic path constituting member 21 are formed.
Since the airtight state in the gap with the plunger 18 can be ensured, a communication path that communicates with the outside via the internal space 16 of the bobbin 14 in which the plunger 18 is accommodated is connected to the yoke 31 formed integrally with the bobbin 14. And the yoke 31
It can be limited to only the gap formed between the inner fitting member 32 and the inner fitting member 32.

For this reason, the inner fitting member 32 is brought into face contact with an inner fitting portion 33 fitted inside the yoke 31 and an upper end surface 34 of the bobbin 14 by projecting laterally from an outer peripheral portion of the inner fitting portion 33. And an upper end surface 34 of the bobbin 14 and a flange 35 of the inner fitting member 32.
By arranging the O-ring 38 surrounding the yoke 31, the communication path can be closed, so that the airtightness of the internal space can be ensured.

Therefore, in order to ensure the airtightness of the internal space 16 in the solenoid 13, the O-rings as seal members must be provided on both end surfaces of the bobbin 14 of the solenoid 13, as compared with the prior art. Is reduced, assemblability is improved, and O
As compared with the case where a ring is provided, the height of the bobbin 14 can be reduced, and the size can be reduced.
Further, the cost can be reduced as compared with a solenoid valve that uses a diaphragm to prevent oil from flowing into the solenoid 13. Further, since the yoke 31 and the core 22 are integrally formed with the bobbin 14, the yoke 31 and the core 22 are provided for improving the performance as compared with a case where the yoke 31 and the core 22 are formed separately from the bobbin 14. Dimension management becomes easy, and cost reduction can be achieved.

In the solenoid valve 1, a lower bearing 47 for supporting the rod 19 provided on the plunger 18 is formed integrally with the bobbin 14 in which the plunger 18 is movably accommodated. Insertion hole 45 of core 22
Therefore, the coaxiality between the yoke 31 and the lower bearing 47 formed integrally with the bobbin 14 can be managed at the time of bobbin molding. Thus, the coaxiality can be easily managed and the operating characteristics of the plunger 18 can be easily improved as compared with the case where the core 22 provided with the lower bearing 47 and the bobbin 14 are formed separately. be able to.

Further, in the solenoid valve 1, communication holes 61, 61 are provided in a step portion 44 of the core 22 protruding from the immersion portion 42, so that the internal space 16 above the core 22 as a boundary is provided. And the lower valve chamber 62 can be communicated through the communication holes 61, 61. As a result, it is possible to promote the discharge of the oil flowing into the internal space 16, so that it is possible to enhance the discharge of contamination such as iron powder contained in the oil in the solenoid 13. In addition, the movement of the plunger 18 can be improved as compared with the case where the oil discharge is delayed. In particular, when the plunger 18 is moved to the step portion 44 side, The force applied in the direction to push back the jar 18 can be suppressed, and the damping of the plunger 18 can be prevented.

Further, in the solenoid valve 1 of the present embodiment, the inner diameter H1 of the immersion portion 42 of the core 22 immersed in the inner wall surface 41 of the bobbin 14, the inner diameter H2 of the yoke 31 and the filling portion Inner dimension H3 at 36
Is set so as to match, so that the inner wall surface 41 of the bobbin 14 can be formed without forming irregularities on the inner mold. Since the inner wall surface 41 of the bobbin 14 can be formed by an inner mold having no unevenness, the inner diameter dimension H1 of the core 22 at the immersion portion 42 is equal to the inner diameter dimension of the yoke 31 and the filling portion 36. Compared to the case where the diameter is formed larger than the dimensions H2 and H3, even when the length dimension of the immersion portion 42 of the core 22 is changed, that is, when the immersion portion 42 and the yoke 31 Even when the opposing position is changed, the yoke 3 can be used without changing the inner mold.
1 and the core 22 can be formed integrally with the bobbin 14.

That is, FIG. 2 is a view showing a solenoid valve 71 according to the second embodiment, and only parts different from those of the first embodiment will be described.

The solenoid valve 71 is of a normally-closed type, and is configured so that the recess 48 provided in the inner fitting member 32 of the magnetic path constituting member 21 penetrates upward. The upper end of the concave portion 48 is closed by the cap member 72, and the sealed state is maintained. On the lower surface of the cap member 72, an upper convex portion 73 protruding downward is formed, and on the upper end of the rod 19 facing the upper convex portion 73, a lower convex portion 74 is formed. The upper convex portion 7
3, the upper end of the coil spring 75 is fitted on the lower convex part 74, and the lower end of the coil spring 75 is fitted on the lower convex part 74.
The rod 19 and the plunger 18 are configured to be constantly urged downward.

The immersed portion 42 of the core 22 integrally formed at the lower end of the bobbin 14 of the solenoid 13 has a length dimension in the height direction longer than that of the first embodiment. The yoke 31 integrally formed on the upper end of the bobbin 14 has a length in the height direction set to be shorter than that of the first embodiment. The opposing position where the immersion part 42 and the yoke 31 oppose each other is set at a higher position than in the first embodiment.

As a result, in the solenoid valve 71 according to the present embodiment, the valve chamber 62 is moved by the rod 19 urged downward by the coil spring 75, as shown on the arrow B side in FIG. Is closed so that the inflow of oil from the inflow path 65 and the outflow of oil from the outflow path 66 are prevented.
When the solenoid 13 is energized, the plunger 18 is attracted to the lower surface of the inner fitting portion 33 of the inner fitting member 32, as shown on the arrow A side in FIG.
The plunger 18 and the rod 19 are moved up,
The opening of the small-diameter hole 67 allows oil from the inflow passage 65 to flow through the outflow passage 6 through the valve chamber 62.
6 so as to flow out.

As described above, even when the facing position where the immersion portion 42 and the yoke 31 face each other is changed to form the normally closed solenoid valve 71, the bobbin 14 is formed as described above. The yoke 31 and the core 22 can be formed integrally with the bobbin 14 without changing the inner mold to be used.

[0038]

As described above, in the solenoid valve according to the first aspect of the present invention, the magnetic path constituting member inserted into the internal space of the bobbin from one end of the bobbin of the solenoid is formed into a cylindrical yoke. And an inner fitting member fitted inside the yoke, and the bobbin is integrally formed of resin with a core fitted inside the yoke and the other end of the bobbin, so that the yoke and the Since a sealed state in the gap with the core can be ensured, a communication path that communicates with the outside through the internal space of the bobbin in which the plunger is accommodated, the yoke integrally formed with the bobbin, and the yoke It is possible to limit only to a gap formed between the inner fitting member to be internally fitted. For this reason, the inner fitting member is formed by an inner fitting portion fitted inside the yoke, and a flange portion projecting laterally from an outer peripheral portion of the inner fitting portion and in contact with one end surface of the bobbin. By disposing a seal member surrounding the yoke between the one end surface of the bobbin and the flange of the inner fitting member, the communication path can be closed, and the internal space is airtight. Nature can be secured.

Therefore, in order to ensure airtightness inside the solenoid, O-rings as seal members must be provided on both end surfaces of the bobbin of the solenoid, and the number of assembling steps is reduced. And the size of the bobbin can be reduced as compared with the case where O-rings are provided at both ends, and downsizing can be achieved. Further, the cost can be reduced as compared with a solenoid valve that uses a diaphragm to prevent oil from flowing into the solenoid. Further, the yoke and the core are:
Since the yoke and the core are integrally formed with the bobbin, dimensional control for improving performance is easier and cost reduction can be achieved as compared with the case where the yoke and the core are formed separately from the bobbin.

In the solenoid valve according to the present invention, the bearing for supporting the insertion bar provided on the plunger is inserted into the insertion hole of the core formed integrally with the bobbin in which the plunger is movably accommodated. With this arrangement, the coaxiality between the yoke and the bearing formed integrally with the bobbin can be managed during bobbin molding. This makes it easier to manage the coaxiality than when the core on which the bearing is provided and the bobbin are formed separately, and can easily improve the operating characteristics of the plunger.

Further, in the solenoid valve according to the third aspect, since the inner diameter of the immersion portion of the core immersed in the inner wall surface of the bobbin is configured to match the inner diameter of the yoke and the filling portion. The inner wall surface of the bobbin can be formed without forming irregularities on the inner mold. Then, since the inner wall surface of the bobbin can be formed by an inner mold having no irregularities, the inner diameter of the core at the immersion portion is formed to be larger than the inner diameter of the yoke and the filling portion. In comparison with the case, even when changing the length dimension of the immersion portion of the core, that is, even when changing the opposing position where the immersion portion and the yoke oppose each other, A bobbin in which the yoke and the core are integrally formed can be formed without changing the inner mold.

In addition, in the solenoid valve according to the fourth aspect, by providing a communication hole in a step portion of the core protruding from the recessed portion, the internal space on one side and the other side with the core as a boundary can be formed. The communication can be performed through the communication hole. Accordingly, the discharge of the oil flowing into the internal space can be promoted, so that the discharge property of the contamination contained in the oil in the solenoid can be enhanced. In addition, the movement of the plunger can be improved as compared with the case where the discharge of the oil is delayed. In particular, when the plunger is moved to the step portion side, the plunger is pushed back. The force applied in the direction can be suppressed, and damping of the plunger can be prevented.

[0043]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional solenoid valve.

FIG. 4 is a cross-sectional view showing another conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 solenoid valve 13 solenoid 14 bobbin 15 coil 16 internal space 18 plunger 19 rod (insertion bar) 21 magnetic path constituent member 22 core 31 yoke 32 inner fitting member 33 inner fitting portion 34 upper end surface 35 flange portion 36 filling portion 38 O-ring (Seal member) 41 Inner wall surface 42 Immersion part 44 Step part 45 Insertion hole 46 Suction surface 47 Lower bearing 61 Communication hole 71 Solenoid valve

Claims (4)

[Claims] 1. A magnetic path forming member inserted into one end of a bobbin of a solenoid from one end of a bobbin to close one end of the inner space, and an inner hole is fitted into the other end of the bobbin and inserted into a center part. And a plunger movably provided in the internal space and provided with an insertion bar for inserting the insertion hole, and a gap is secured between the magnetic path constituting member and the core. In the solenoid valve described above, the magnetic path constituting member is formed such that a cylindrical yoke in which the plunger is movably fitted, an inner fitting portion fitted in the yoke, and an outer peripheral portion of the inner fitting portion. The bobbin is integrally formed with a resin together with the yoke and the core, and the bobbin is integrally formed with a resin. The resin was filled in the gap To form a Hama portion, between the flange portion of the inner fitting member and the end surface of the bobbin,
An electromagnetic valve, comprising a seal member surrounding the yoke. 2. The solenoid valve according to claim 1, wherein a bearing for supporting the insertion bar of the plunger is provided in the insertion hole of the core. 3. The core according to claim 1, wherein the core includes a recessed portion that is immersed in the inner wall surface of the bobbin, and a stepped portion that projects toward the center from the recessed portion and is provided with the insertion hole. 3. The solenoid valve according to claim 1, wherein an inner diameter of the portion is made to match an inner diameter of the yoke and the filling portion. 4. The solenoid valve according to claim 3, wherein a communication hole is provided in the step portion of the core, the communication hole communicating the internal space on one side of the core with the other side.