JP2012047283A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excellently maintain airtightness by securing a plane state of a seal surface of a bobbin even when a die structure for resin molding is restricted.SOLUTION: When an outer package resin part 5 and a connector part 6 are integrally resin-molded, a resin flowing in a gap of a die forming the outer package resin part 5 is stopped at a projection part forming a groove part 20 and does not project to a bobbin step part 1a ahead thereof. Consequently, the occurrence of resin burrs at the bobbin step part 1a which is a seal surface of an O-ring 12 can be prevented.

Description

  The present invention relates to an electromagnetic valve in which a bobbin around which a coil is wound is inserted, and a connector portion and an exterior resin portion of the coil are integrally molded.

  A conventional solenoid valve (see, for example, Patent Document 1) axially drives a flow rate regulating portion in which a spool valve is slidably disposed in a valve housing having a plurality of fluid ports, and a plunger connected to the spool valve. And a solenoid portion. Of the solenoid portion, the coil molded body is integrally molded with a resin member using a coil bobbin wound with a linear coil, a core as a stator, and a terminal electrically connected to the linear coil as insert parts. At this time, the resin member embeds a part of the terminal, and a connector portion having a shape opening in a direction orthogonal to the axial direction of the bobbin (that is, the axial direction of the spool valve) is also formed. Further, a boss (stator) is inserted into the end portion of the coil bobbin opposite to the core arrangement side with the O-ring sandwiched, and airtightness inside and outside the coil molded body is secured by the O-ring.

JP 2006-183754 A

  Here, at the time of resin molding of the coil molded body, molding is performed using a mold that matches the shape of the part to be inserted, but since a gap for forming the connector part is formed on one side in the axial direction, It is impossible to apply pressure by fastening the mold in the axial direction. Due to this restriction, a gap is generated between the end face of the coil bobbin that is in contact with the O-ring and serves as a seal surface, and the mold due to variations in component dimensions. Then, the resin member enters the gap during molding, and appears as a resin burr (resin overhang) on the end face of the coil bobbin after molding. When a resin burr | flash generate | occur | produces on the sealing surface, there exists a concern that the normal seal | sticker by an O-ring will become impossible and an airtight abnormality will arise as a result.

  The present invention has been made to solve the above-described problems, and even if there is a restriction on the mold structure of the resin molding, the flat state of the sealing surface of the bobbin is ensured and the airtightness is favorably maintained. For the purpose.

  The electromagnetic valve according to the present invention is wound around the outer periphery of the bobbin, a cylindrical bobbin having a through-hole through which the mover is inserted, a stator including a core and a boss disposed at both ends of the bobbin through-hole. A coil, a bobbin around which the core is disposed and the coil is wound are packaged by resin molding, and an exterior resin part that integrates the core and the bobbin is integrated on an end surface of the exterior resin part on the side where the core is disposed A connector part that is resin-molded and opens in a direction perpendicular to the axial direction of the bobbin, a seal member that is installed between the boss with the end face of the bobbin as a seal face, and the bobbin end face and exterior resin part that become the seal face And a solenoid part provided with a groove part formed at the boundary part.

  According to the present invention, the groove portion is formed at the boundary portion with the exterior resin portion so as to surround the outer surface of the sealing surface of the bobbin end surface, and therefore flows into the mold gap forming the exterior resin portion during resin molding. It is possible to prevent the resin burr from being generated because the resin is stopped by the convex portion of the mold that forms the groove and does not protrude from the sealing surface of the bobbin end face. Therefore, even if there is a restriction on the mold structure of the resin molding, the flat state of the sealing surface can be ensured and the airtightness can be maintained well.

It is a longitudinal cross-sectional view which shows the structure of the solenoid valve which concerns on Embodiment 1 of this invention. It is an enlarged view of the part enclosed with the broken line in FIG. It is a longitudinal cross-sectional view which shows the structure of the metal mold | die which shape | molds the coil molded object of the solenoid valve which concerns on Embodiment 1. FIG. It is an enlarged view of the part which shape | molds a groove part among the metal mold | dies shown in FIG. It is an enlarged view which shows the metal mold | die when not forming a groove part (conventional).

Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view of a solenoid valve according to Embodiment 1, and an enlarged view of a portion surrounded by a broken line is shown in FIG. Here, for convenience of explanation, the direction in which the connector portion 6 of the electromagnetic valve is disposed is up, and the direction in which the spring 17 is disposed is down.

  In this electromagnetic valve, the bobbin 1 is formed in a substantially cylindrical shape by resin molding, and a coil 2 is wound around the outer periphery. Further, flanges are formed at both end portions of the bobbin 1, a terminal 3 is provided at the upper flange, and a bobbin step portion serving as a sealing surface of the O-ring 12 at the lower flange (bobbin flange 1b). 1a and a groove 20 (shown in FIG. 2) are provided. The starting end and the terminating end of the coil 2 are connected to the corresponding terminals 3, and a current is applied from an external power source (not shown). A core 4 and a boss 8 as a pair of stators are inserted into a through hole formed in the center of the bobbin 1. The core 4 which is one stator is a bottomed cylindrical metal member, the core cylinder portion 4a is inserted into the through hole of the bobbin 1, the core collar portion 4b is attached to the upper end portion of the bobbin 1, The bottom 4c closes the through hole of the bobbin 1. The boss 8 as the other stator is a cylindrical metal member provided with a boss flange 8b at one end, and the magnetic attracting part 8a is inserted into the through-hole of the bobbin 1 from below. Furthermore, O-rings 11 and 12 are installed in the inside and end of the coil molded body 7 as seal members for securing airtightness, respectively.

  The coil molded body 7 is formed by integrally molding the bobbin 1, the coil 2, the terminal 3, the core 4, and the O-ring 11 with the exterior resin portion 5 as insert parts. On the end surface of the exterior resin portion 5 on the side where the core 4 is disposed, a connector portion 6 that is open in a direction orthogonal to the axial direction of the bobbin 1 is integrally formed.

  As shown in FIG. 2, the O-ring 12 is in a space surrounded by a bobbin step 1a projecting from the lower end surface of the bobbin collar 1b, the inner peripheral surface of the exterior resin part 5, and the boss collar 8b. It is installed and seals each abutment surface. A groove portion 20 is provided on the outer side in the radial direction of the bobbin collar 1 b, that is, on the boundary portion between the lower end surface of the bobbin 1 and the exterior resin portion 5. The groove 20 has a role of preventing the resin from sticking out to the bobbin step portion 1a which is the sealing surface when the exterior resin portion 5 is molded. In addition, since the groove part 20 is not the sealing surface which contact | abuts to the O-ring 12, even if the groove part 20 has produced the burr | flash, it is accept | permitted.

Here, a method for forming the coil molded body 7 will be described.
FIG. 3 is a cross-sectional view showing a structure of a mold for forming the coil molded body 7, and an enlarged view of a mold part for forming the groove 20 is shown in FIG. 4. The coil molded body 7 has a connector portion 6 formed on the end surface of the exterior resin portion 5 on the side where the core 4 is disposed, and the connector portion 6 has a shape that opens in a direction perpendicular to the axial direction of the bobbin 1. The mold for molding the molded body 7 includes upper molds 30 and 31 and a lower mold 32. The upper mold 30 and 31 and the lower mold 32 are opened and closed in the vertical direction, and the upper mold 30 and the upper mold 31 are opened and closed in the horizontal direction. In addition, the mold mainly includes a gap for forming the exterior resin portion 5 and a gap for forming the connector portion 6.

  First, the coil 2 is wound around the outer peripheral surface of the resin-molded bobbin 1, and the core 4 is press-fitted and fixed to the bobbin 1 with the O-ring 11 sandwiched therebetween. Subsequently, the terminal 3 is attached to the bobbin 1, and the start end and the end end of the coil 2 are connected to the terminal 3. When the bobbin 1, the coil 2, the terminal 3, the core 4, and the O-ring 11 are arranged as insert parts in the lower mold 32, the lower surface of the core flange 4b is hooked on the upper edge of the lower mold 32 and positioned. Is done. Accordingly, since the bobbin 1 is also positioned with the hook portion 33 as a base point, the dimensions of the bobbin 1, the core 4 and the lower die 32 are provided between the gap bottom surface 32a of the lower die 32 and the bobbin step portion 1a. Due to tolerances, a predetermined gap exists. However, even if the upper mold 30, 31 and the lower mold 32 are fastened and axial pressure is applied to the lower mold 32, the bobbin step portion 1a is pressed by the gap bottom surface 32a due to the structure of the mold. Therefore, the gap existing between the gap bottom surface 32a and the bobbin step portion 1a is not blocked. This is the same as described in the background art.

  Subsequently, the upper molds 30 and 31 are joined to the lower mold 32, and the resin is injected from the resin injection gate 31 a of the upper mold 31. The injected resin flows into the gap forming the connector portion 6 and is molded in a state where the bent portion of the terminal 3 is embedded. Further, the injected resin passes through the hole opened in the core flange 4b and flows out to the gap of the lower mold 32, particularly to the bulge portion represented by the broken line on the side where the terminal 3 is attached, and to the exterior resin portion 5 The coil 2 and the core 4 are formed in a state where the bobbin 1 is sheathed.

  As shown by the arrows in FIG. 4, the resin that flows in the gap forming the exterior resin portion 5 and reaches the gap bottom surface 32a hits the convex portion 32b protruding from the gap bottom surface 32a. The convex portion 32 b has a shape corresponding to the groove portion 20. By forming the convex portion 32b, the boundary portion between the bobbin 1 and the exterior resin portion 5 has a labyrinth structure, the resin is stopped in the labyrinth, and a resin burr is generated in the bobbin step portion 1a as a sealing surface. Can be prevented. Accordingly, even if there is a gap between the bobbin step portion 1a and the gap bottom surface 32a due to the structure of the mold, the plane of the bobbin step portion 1a with which the O-ring 12 abuts is maintained, and good sealing performance can be ensured. it can.

  On the other hand, as shown in FIG. 5, when the convex portion 32b is not provided on the gap bottom surface 32a of the lower mold 32, the resin that has reached the gap forming the exterior resin portion 5 is formed between the bobbin collar 1b and the gap bottom surface 32a. It tends to flow into the gap and protrudes into a burr. Then, a resin burr | flash generate | occur | produces in the lower end surface of the bobbin 1 which is a sealing surface which O-ring 12 contact | abuts, and there exists a problem which a sealing function is impaired.

Further, as shown in FIG. 4, since the tip of the bobbin collar 1b arranged in the lower mold 32 protrudes into the gap forming the exterior resin part 5, the exterior resin part 5 is recessed outward in the radial direction. Is formed into a shape for gripping the bobbin collar 1b. Therefore, after molding, deformation of the bobbin collar 1b and the bobbin step 1a as the sealing surface can be prevented, and the airtightness of this part can be further stabilized.
Similarly, the exterior resin portion 5 is configured to grip the upper edge side of the bobbin 1.

  Note that an O-ring 12 is suitable as a seal member for sealing a gap between the bobbin step portion 1a and the boss 8. For example, when a liquid sealant is used as the seal member, it is possible to ensure airtightness between the bobbin step 1a and the boss 8 by applying the sealant on the plane of the bobbin step 1a. It is difficult to apply it to the surface, and it takes time to dry the sealant, so that problems such as retention in the manufacturing process remain, which is not preferable.

  A case 9 as shown in FIG. 1 is provided around the outer periphery of the coil molded body 7 formed as described above. The case 9 is a cylindrical metal member and constitutes a magnetic circuit. The upper end portion of the case 9 is a case bent portion 9a that is bent inward, and the outer peripheral portion of the core flange portion 4b is fitted to the inner peripheral portion thereof to form a magnetic path and the core 4 and the case. Nine coaxials are formed. The lower end portion of the case 9 is formed with a case staircase portion 9b with a reduced thickness, and the stepped portion is fitted to the boss flange portion 8b. Further, the valve housing 15 is inserted into the case stepped portion 9b after the boss flange portion 8b, and the end portions thereof are caulked to hold the respective parts integrally and coaxially. A substantially L-shaped bracket 10 is fixed to the outer peripheral surface of the case 9 by welding or the like.

The cup member 13 is formed from a non-magnetic thin plate, and is inserted into the cylinder of the core 4 to function as a bearing. Inside the cup member 13, a plunger 14, which is a mover, is accommodated with a predetermined clearance so as to be slidable back and forth in the vertical axis direction. A cup bottom 13a is formed on the upper side of the cup member 13, and a hole is formed in the center of the cup bottom 13a. The cup bottom part 13a functions as a stopper for restricting the movement of the plunger 14 when no power is supplied by contacting the upper end surface of the plunger 14. The lower end portion of the cup member 13 is expanded in diameter to accommodate the magnetic attraction portion 8a of the boss 8 therein, and further reaches the lower end surface of the bobbin 1, and a cup collar 13b (shown in FIG. 2) is provided at the periphery of the opening. Is formed. The cup collar 13b is hooked on the lower end surface of the bobbin 1, whereby the axial position of the cup member 13 is determined, whereby the cup bottom 13a is separated from the core bottom 4c. Then, by forming a hole portion (not shown) that penetrates in the vertical axis direction and functions as a breathing hole in the center of the plunger 14, a space that can be moved up and down in the axial direction of the plunger 14 when the plunger 14 reciprocates. Therefore, the plunger 14 can operate normally.
The above is the solenoid part of the solenoid valve.

Next, the flow regulating part of the solenoid valve will be described.
The flow rate restricting unit always includes one substantially cylindrical valve housing 15 having a plurality of ports 15a, a spool valve (valve) 16 accommodated in the valve housing 15 so as to be slidable in the axial direction, and one spool valve 16. And a spring 17 biasing in the direction. By connecting the spool valve 16 and the plunger 14 on the same axis, the spool valve 16 moves according to the movement amount of the plunger 14. When no power is supplied as shown in FIG. 1, the plunger 14 moves upward by the urging force of the spring 17. The movement range of the plunger 14 at this time is up to a position where the upper end surface of the plunger 14 comes into contact with the cup bottom 13a. During one energization, the plunger 14 receives the magnetic attractive force of the magnetic attractive portion 8a and moves downward against the urging force of the spring 17. The moving range at this time is up to a position where the lower end portion of the spool valve 16 contacts the bottom portion of the valve housing 15. The movement of the spool valve 16 controls the flow direction of the fluid by controlling the direction and amount of the plurality of land portions having a diameter expanded from the spool valve 16 to open each port 15a.

  The fluid to be controlled by this electromagnetic valve may be liquid or gas. For example, when used as an electromagnetic valve for controlling the hydraulic pressure supplied to the hydraulic actuator of the internal combustion engine, the flow rate of oil supplied from the pump to the hydraulic actuator by controlling the opening direction and the opening amount of each port 15a of the valve housing 15 It suffices if the configuration controls the above.

  The fluid flowing through the valve housing 15 may enter the inside of the coil molded body 7, particularly the coil 2, through the magnetic attraction portion 8 a of the boss 8. Therefore, in order to prevent the fluid leaking from the gap between the core 4 and the cup member 13 from entering the inside of the coil molded body 7 through the gap between the core 4 and the bobbin 1, an O is interposed between the core 4 and the bobbin 1. The gap is closed by sandwiching the ring 11 to ensure the airtightness inside the coil molded body 7. Further, in order to prevent the fluid leaking from the gap between the boss 8 and the cup member 13 from entering the inside of the coil molded body 7 through the gap between the boss 8 and the bobbin 1, the gap between the bobbin 1 and the boss 8 is The gap is closed by sandwiching the O-ring 12 to ensure the airtightness of the end of the coil molded body 7.

Furthermore, by crimping the case step 9b with the O-ring 18 sandwiched between the boss 8 and the valve housing 15, the gap between the boss 8 and the valve housing 15 is closed to ensure airtightness. Further, when the solenoid valve is used with the valve housing 15 inserted into a mounting hole (not shown), an O-ring 19 is installed on the outer peripheral surface of the valve housing 15 to close the gap between the valve housing 15 and the mounting hole. Ensure airtightness.
For example, acrylic rubber or fluororubber is used as a constituent member of the O-rings 11, 12, 18, and 19.

  As described above, the electromagnetic valve according to the first embodiment is a stator including the cylindrical bobbin 1 having a through hole through which the plunger 14 is inserted, and the core 4 and the boss 8 disposed at both ends of the through hole of the bobbin 1. And a coil 2 wound around the outer periphery of the bobbin 1 and a bobbin 1 on which the core 4 is disposed and the coil 2 is wound is packaged by resin molding, and the core 4 and the bobbin 1 are integrated. 5 and a resin part integrally molded on the end surface of the exterior resin part 5 on the side where the core 4 is disposed, and a connector part 6 that opens in a direction perpendicular to the axial direction of the bobbin 1, and the end face of the bobbin 1 as a sealing surface, It has a solenoid portion configured to include an O-ring 12 installed between the boss 8 and a groove portion 20 formed in a boundary portion with the exterior resin portion 5 so as to surround the outside of the seal surface. For this reason, the resin that has flowed into the gap that forms the exterior resin portion 5 of the lower mold 32 during resin molding is stopped by the convex portion 32b that forms the groove portion 20 and does not protrude to the bobbin step portion 1a. Generation of burrs can be prevented. Therefore, even if there is a restriction on the mold structure for resin molding of the coil molded body 7, it is possible to ensure a flat state of the bobbin stepped portion 1 a serving as the seal surface of the O-ring 12 and to maintain good airtightness. it can.

  Further, according to the first embodiment, the bobbin collar 1b protruding radially outward is provided at the end of the bobbin 1, and the exterior resin part 5 is shaped to grip the bobbin collar 1b. Deformation of the bobbin step 1a serving as the sealing surface can be prevented, and the airtightness can be further stabilized.

In the illustrated example, the flow restricting portion is configured by a spool valve, but is not limited to this, and may be a valve other than the spool valve.
In the present invention, the embodiments can be appropriately changed or omitted within the scope of the invention.

  1 bobbin, 1a bobbin step part, 1b bobbin collar part, 2 coil, 3 terminal, 4 core, 4a core cylinder part, 4b core collar part, 4c core bottom part, 5 exterior resin part, 6 connector part, 7 coil molded body, 8 Boss, 8a Magnetic attracting part, 8b Boss collar part, 9 Case, 9a Case bent part, 9b Case step part, 10 Bracket, 11, 12, 18, 19 O-ring, 13 Cup member, 13a Cup bottom part, 14 Plunger, 15 valve housing, 15a port, 16 spool valve, 17 spring, 20 groove, 30, 31 upper mold, 31a resin injection gate, 32 lower mold, 32a gap bottom, 32b convex.

Claims (2)

In a solenoid valve having a valve that opens and closes a port formed in the valve housing, and a solenoid unit that drives a mover connected to the valve,
The solenoid part is
A cylindrical bobbin having a through hole through which the mover is inserted;
A stator composed of a core and a boss disposed at both ends of the bobbin through-hole,
A coil wound around the outer periphery of the bobbin;
The bobbin around which the core is disposed and the coil is wound is packaged by resin molding, and an exterior resin part that integrates the core and the bobbin;
A connector part integrally molded on the end surface of the exterior resin part on the core arrangement side, and opened in a direction orthogonal to the axial direction of the bobbin;
A seal member installed between the boss and the end surface of the bobbin as a seal surface;
An electromagnetic valve comprising: a groove portion formed at a boundary portion with the exterior resin portion so as to surround the outside of the seal surface. Providing a flange projecting radially outward at the end of the bobbin,
The solenoid valve according to claim 1, wherein the exterior resin portion has a shape for gripping the flange portion.

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