JP6249285B2 - solenoid valve - Google Patents

Description

  In the present invention, a yoke is constituted by a bottomed cylindrical main yoke having a ceiling wall integrally formed at one end and the other end being opened, and an auxiliary yoke that closes the open end of the main yoke. A coil assembly in which a coil is wound is housed, a fixed core is disposed in a hollow portion of the bobbin, and a flange formed at one end of the fixed core is sandwiched between the ceiling wall and the bobbin, and the auxiliary yoke A movable core penetrating the fixed core in the hollow portion of the bobbin, a valve body is attached to the tip of the movable core, and the control base to which the yoke is fixed is not energized with the coil. The present invention relates to an improvement in an electromagnetic valve in which a valve seat member on which a valve body is seated is provided and the movable core is urged by a coil spring in a seating direction with the valve seat member of the valve body.

  Such a solenoid valve is already known as disclosed in Patent Document 1.

JP-A-9-242916

  In the solenoid valve described in the above publication, a sealing member surrounding the fixed core is interposed between the flange of the fixed core and the bobbin in order to block communication with the outside of the hollow portion of the bobbin. The seal member has a drawback that the length in the axial direction of the solenoid valve is somewhat increased by overlapping with the flange in the axial direction. In addition, a lower spring constant of the coil spring that biases the movable core in the valve closing direction is more advantageous for improving the valve opening response of the movable core. Since the coil spring is contracted in a narrow space between the fixed core and the movable core, there is also a drawback that it is difficult to set the spring constant low while securing a predetermined set load because the coil spring cannot be made long enough.

  The present invention has been made in view of such circumstances, and a seal member can be installed without increasing the length in the axial direction to block communication with the outside of the hollow portion of the bobbin. It is an object of the present invention to provide an electromagnetic valve that can be installed with a long coil spring and can set a low spring constant while ensuring a predetermined set load.

  To achieve the above object, the present invention comprises a yoke having a bottomed cylindrical main yoke integrally having a ceiling wall at one end and the other end being opened, and an auxiliary yoke closing the open end of the main yoke. A coil assembly formed by winding a coil around a bobbin is accommodated in the yoke, a fixed core is disposed in the hollow portion of the bobbin, and a flange formed at one end of the fixed core is connected to the ceiling wall and A movable core sandwiched by a bobbin and penetrating the auxiliary yoke is disposed opposite to the fixed core in the hollow portion of the bobbin, a valve body is provided at the tip of the movable core, and a control base to which the yoke is fixed, A solenoid valve comprising a valve seat member on which the valve body is seated when the coil is not energized, and the movable core is urged in a seating direction with the valve seat member of the valve body by a coil spring. Have The yoke is made of a press, the hollow portion that communicates between both end faces is formed in the fixed core, and the coil spring that is contracted between the ceiling wall and the movable core is disposed in the hollow portion, A seal groove surrounding the flange is formed on an end surface of the bobbin or a coating layer covering the bobbin facing the ceiling wall, and a seal member that is in close contact with the ceiling wall is attached to the seal groove. Is the first feature. The seal member corresponds to a second seal member 16 in an embodiment of the present invention described later.

  In addition to the first feature, the present invention has a second feature in that a leaf spring for biasing the flange and the bobbin apart from each other along the axial direction is interposed between the flange and the bobbin. And

  In addition to the first feature of the present invention, the movable core is solidly formed, the inner end thereof is provided with a short shaft that supports the movable end of the coil spring, and the outer end thereof is provided with the valve element. The third feature is that they are integrally formed.

  Furthermore, the present invention is characterized in that, in addition to the first or second feature, the fixed core having the flange at one end is made of a press.

  According to the first feature of the present invention, the seal member that blocks communication with the outside of the hollow portion of the bobbin is attached to the seal groove that surrounds the flange of the fixed core. Therefore, the length of the solenoid valve in the axial direction is not increased, which can contribute to the compactness of the solenoid valve.

  In addition, the smooth inner surface of the ceiling wall of the press-made main yoke itself becomes the surface where the flange comes into contact and the surface where the seal member comes into close contact, so that the flange can be applied without any special cutting work on the inner surface of the ceiling wall. The surface to be in contact with and the surface to which the seal member is in close contact can be obtained, and the manufacture becomes easy.

  Furthermore, the coil spring penetrates the hollow portion of the fixed core and is contracted between the ceiling wall and the movable core, so that the total length thereof can be set longer than the axial length of the fixed core. Accordingly, the spring constant can be set sufficiently low while applying a predetermined set load to the coil spring, and the suction response of the movable core, that is, the valve opening response of the valve element can be enhanced.

  According to the second feature of the present invention, since the leaf spring between the flange and the bobbin is urged in the direction away from each other along the axial direction, the play between the flange and the bobbin is prevented. It can be eliminated, and it can be prevented from being damaged by avoiding axial overload on the synthetic resin bobbin during assembly.

  According to the third feature of the present invention, the movable core is solidly formed, the short shaft supporting the movable end of the coil spring is formed at the inner end thereof, and the valve body is integrally formed at the outer end thereof. Therefore, the coil spring can be supported and the valve body can be coupled without adding a special member to the movable core, and the number of parts can be reduced.

  According to the fourth feature of the present invention, since the fixed core with the flange is made of press, the main yoke is made of press, so that the fixed core is fixed to the smooth inner surface of the ceiling wall of the main yoke. By assembling a smooth flange, the assembly accuracy can be increased. Moreover, in the fixed core, the flange and the hollow portion can be formed at once by press working, and the manufacture becomes easier.

The top view of the solenoid valve which concerns on embodiment of this invention. FIG. 2 is an enlarged sectional view taken along line 2-2 in FIG. 1.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 and 2, a bracket 2 of an electromagnetic valve S that opens and closes the oil passage 1 is fastened to a control base B having the oil passage 1 by a bolt 3.

  As clearly shown in FIG. 2, the yoke 4 of the electromagnetic valve S includes a bottomed cylindrical main yoke 5 integrally having a ceiling wall 5 a at one end and an open end, and an open end portion of the main yoke 5. The bracket 2 is formed integrally with the lower end of the main yoke 5. The main yoke 5 is made of press.

  A coil assembly 9 formed by winding a coil 8 around a bobbin 7 is accommodated in the yoke 4, and a synthetic resin coating layer 10 is formed on the outer periphery of the coil assembly 9 by injection molding. . At this time, the coupler 12 is formed integrally with the coating layer 10 so as to protrude to one side of the coil assembly 9, and the power feeding terminal 11 connected to the coil 8 is held by the coupler 12. The main yoke 5 is provided with a notch 13 through which the neck of the coupler 12 passes. A first seal member 14 is interposed between the auxiliary yoke 6 and the bobbin 7.

  A flange 15a sandwiched between the inner surface of the ceiling wall 5a and the upper end surface of the bobbin 7 is integrally formed at the upper end of the fixed core 15 disposed in the hollow portion 7a of the bobbin 7, and the flange 15a and A leaf spring 21 such as a wave washer is interposed between the bobbins 7, thereby eliminating backlash between the flange 15a and the bobbin 7, and an axial overload is applied to the synthetic resin bobbin 7 during assembly. Can be avoided and the damage can be prevented.

  An annular seal groove 24 surrounding the flange 15a is provided on the upper end surface of the bobbin 7 or the covering layer 10 covering the bobbin 7, and the seal groove 24 is in close contact with the inner surface of the ceiling wall 5a. Two seal members 16 are mounted.

  A movable core 17 facing the fixed core 15 in the hollow portion 7a of the bobbin 7 is disposed so as to pass through the through hole 18 of the auxiliary yoke 6, and a nonmagnetic set collar 19 that holds the movable core 17 is transparent. Attached to the hole 18. The set collar 19 has a mounting flange 19a disposed between the bobbin 7 and the auxiliary yoke 6 at the inner end (upper end), and an inward flange 19b at the outer end (lower end) to prevent the movable core 17 from falling off. have. The set collar 19 prevents the movable core 17 from being detached from the through hole 18 before the bracket 2 of the yoke 4 is attached to the control base B. After the bracket 2 is attached to the control base B, the movable core 17 is prevented. So as not to interfere with the reciprocal operation of the.

  The fixed core 15 has a hollow portion 15b communicating between both end faces thereof, and a coil spring 20 that is contracted between the ceiling wall 5a and the movable core 17 is accommodated in the hollow portion 15b. As described above, the fixed core 15 having the flange 15a and the hollow portion 15b is made of press.

  On the other hand, the movable core 17 is solid, and a short shaft 17a for positioning and holding the movable end of the coil spring 20 is formed on the suction surface (upper end surface) of the movable core 17, and the outer end surface (lower end surface) thereof. The conical valve elements 25 are integrally formed. In addition, a plurality of grooves 28 communicating between both end surfaces of the movable core 17 are provided on the outer peripheral surface of the movable core 17. A nonmagnetic washer 23 held by the coil spring 20 is disposed on the suction surface of the movable core 17.

  A valve seat member 26 on which the valve body 25 is seated is interposed in the oil passage 1 of the control base B. Thus, the oil passage 1 is opened and closed by the separation and seating of the valve body 25 with respect to the valve seat member 26.

  A third seal member 27 surrounding the set collar 19 is interposed between the auxiliary yoke 6 and the control base B.

  Next, the operation of this embodiment will be described.

  When the coil 8 is not energized, the movable core 17 is separated from the fixed core 15 by the set load of the coil spring 20 to seat the valve body 25 on the valve seat member 26 and close the oil passage 1. When the coil 8 is energized, the magnetic flux generated thereby flows sequentially to the fixed core 15, the main yoke 5, the auxiliary yoke 6, the movable core 17 and the fixed core 15, and is generated by the magnetic force generated between the fixed core 15 and the movable core 17. The movable core 17 is attracted to the fixed core 15 against the set load of the coil spring 20 and is attracted through the non-magnetic washer 23, and the valve body 25 is opened, that is, separated from the valve seat member 18. As a result, the oil passage 1 is opened.

  By the way, the hollow portion 7 a of the bobbin 7 is always filled with the hydraulic oil of the oil passage 1, but the hollow portion 7 a is interposed between the bobbin 7 and the ceiling wall 5 a of the main yoke 5. Since the communication with the outside is blocked by the cooperation of the seal member 16 and the first seal member 14 and the third seal member 27, the hydraulic oil in the bobbin 7 is prevented from leaking to the outside. It is also possible to prevent dust from entering the bobbin from the outside.

  In addition, since the second seal member 16 is mounted in the seal groove 24 surrounding the flange 15a of the fixed core 15, the second seal member 16 is aligned with the flange 15a in the circumferential direction. The directional length is not increased, and the solenoid valve S can be made compact.

  Further, the smooth inner surface itself of the ceiling wall 5a of the press-made main yoke 5 becomes a surface against which the smooth flange 15a of the fixed core 15 made of press comes into contact, and the second seal member 16 also comes into close contact with the ceiling wall 5a. A smooth abutting surface between the ceiling wall 5a and the flange 15a and a surface where the second seal member 16 is brought into close contact with each other can be obtained without performing special cutting on the inner surface of the flange 5a and the flange 15a. At the same time, production becomes easier. In particular, in the fixed core 15, the flange 15 a and the hollow portion 15 b can be formed at a stroke by pressing, and the manufacture becomes easier.

  The coil spring 20 passes through the hollow portion 15b of the fixed core 15 and is contracted between the ceiling wall 5a and the movable core 17, so that the entire length thereof is longer than the axial length of the fixed core 15. Can be set. Therefore, the spring constant can be set sufficiently low while applying a predetermined set load to the coil spring 20. The low spring constant of the coil spring 20 means that when the movable core 17 operates in the valve opening direction of the valve body 25, the increase in the repulsive force of the coil spring 20 is small. That is, the valve opening response of the valve body 25 can be improved.

  When the coil 8 is de-energized, the movable core 17 is separated from the fixed core 15 by the repulsive force of the coil spring 20 and the valve body 25 is returned to the closed state. At this time, the nonmagnetic washer 23 provided on the attracting surface of the movable core 17 eliminates the residual magnetism between the cores 15 and 17 and improves the return response of the movable core 17. Moreover, since the washer 23 is held on the suction surface of the movable core 17 using the coil spring 20, the holding structure is simple.

  In addition, the movable core 17 is formed solid, and a short shaft 17a for supporting the movable end of the coil spring 20 is integrally formed at the inner end thereof, and a valve body 25 is integrally formed at the outer end thereof. Without adding a special member to 17, the coil spring 20 can be supported and the valve body 25 can be coupled, and the number of parts can be reduced. In addition, since the outer peripheral surface of the solid movable core 17 is provided with a plurality of grooves 28 communicating between the both end faces, when the movable core 17 reciprocates, the hydraulic oil flows through the grooves 28. The reciprocal operation is not hindered.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, in order to communicate between both end surfaces of the solid movable core 17, a plurality of flat surfaces instead of the plurality of grooves 28 can be formed on the outer periphery of the movable core 17.

B ... Control body S ... Solenoid valve 4 ... Yoke 5 ... Main yoke 5a ... Ceiling wall 6 ... Auxiliary yoke 7 ... Bobbin 7a ... Bobbin hollow portion 8 ... Coil 9 ... Coil assembly 10 ... Cover layer 15 ... Fixed core 15a ... Fixed core flange 15b ... Fixed core hollow portion 16 ... Seal Member (second seal member)
17 ... movable core 17a ... short shaft 20 ... coil spring 21 ... leaf spring 24 ... seal groove 25 ... valve element 26 ... valve seat member

Claims (4)

A yoke (4) includes a bottomed cylindrical main yoke (5) having a ceiling wall (5a) integrally at one end and the other end opened, and an auxiliary yoke (6) closing the open end of the main yoke (5). The coil assembly (9) formed by winding the coil (8) around the bobbin (7) is accommodated in the yoke (4), and the hollow portion (7a) of the bobbin (7) is accommodated in the yoke (4). A fixed core (15) is disposed, and a flange (15a) formed at one end of the fixed core (15) is sandwiched between the ceiling wall (5a) and the bobbin (7), and penetrates through the auxiliary yoke (6). The movable core (17) is disposed opposite the fixed core (15) in the hollow portion (7a) of the bobbin (7), a valve body (25) is attached to the tip of the movable core (17), and the yoke ( 4) When the coil (8) is not energized to the control base (B) to which the coil is fixed A valve seat member (26) on which the valve body (25) is seated is provided, and the movable core (17) is attached to the valve seat member (26) of the valve body (25) by a coil spring (20). In a solenoid valve
The main yoke (5) having the ceiling wall (5a) is made of press, and a hollow portion (15b) communicating between both end surfaces is formed in the fixed core (15), and the hollow portion (15b) The coil spring (20) which is contracted between the ceiling wall (5a) and the movable core (17) is disposed on the bobbin (7) or the covering layer (10) covering the bobbin (7). A seal groove (24) surrounding the flange (15a) is formed on an end surface facing the ceiling wall (5a), and the seal member is in close contact with the ceiling wall (5a) in the seal groove (24) (16) A solenoid valve characterized by being mounted. The solenoid valve according to claim 1,
A plate spring (21) is provided between the flange (15a) and the bobbin (7) to bias the flange (15a) and the bobbin (7) away from each other along the axial direction. Solenoid valve. The solenoid valve according to claim 1,
The movable core (17) is solidly formed, the inner end thereof is provided with a short shaft (17a) for supporting the movable end of the coil spring (20), and the outer end thereof is provided with the valve body (25). A solenoid valve characterized by being integrally formed. The solenoid valve according to claim 1 or 2,
A solenoid valve characterized in that the fixed core (15) having the flange (15a) at one end is made of a press.

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