JP2008306123A - Electromagnetic actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve magnetic efficiency in a magnetic circuit by suppressing the leakage of magnetic flux in the magnetic circuit. <P>SOLUTION: The electromagnetic actuator 10 has first and second solenoids 18a, 18b composing a solenoid section 18 inside first and second housings 12, 14, respectively. Between the first and second housings 12, 14, a separation holder 22 made of a non-magnetic material is arranged. A first coil 24 of the first solenoid 18a is excited, thus displacing a first plunger 26 axially, and displacing a second plunger 30 via a shaft 32 inserted into the first plunger 26. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic actuator capable of displacing a moving element by attracting a movable core to a fixed core by electromagnetic force generated under the excitation action of a solenoid coil.

  2. Description of the Related Art Conventionally, there has been known an electromagnetic actuator that displaces a shaft connected to a movable iron core along an axial direction by attracting the movable iron core to a fixed iron core by an electromagnetic force generated under the excitation action of a solenoid coil.

  For example, as shown in FIG. 4, such an electromagnetic actuator has a first fixed magnetic pole 1 provided at one end thereof, and a first plunger 3 is provided on the outer peripheral side of the first fixed magnetic pole 1 via a sleeve 2. A first coil 4 a is provided on the outer peripheral side of the first plunger 3 while being disposed so as to be freely displaceable. A second fixed magnetic pole 5 is provided below the first coil 4 a and the first plunger 3, and a second plunger 6 is movably provided inside the second fixed magnetic pole 5. A third fixed magnetic pole 7 is provided at the other end of the electromagnetic actuator (see, for example, Patent Document 1).

  Then, by exciting the first coil 4a, a magnetic circuit 8 is generated around the first coil 4a, the first plunger 3, the first fixed magnetic pole 1 and the second fixed magnetic pole 5, and the first and second plungers 3 are generated. , 6 is attracted to the third fixed magnetic pole 7 side and in addition to exciting the second coil 4b, in addition to the magnetic circuit 8, the second coil 4b, the second plunger 6, the second fixed magnetic pole 5 and a magnetic circuit 9 around the third fixed magnetic pole 7 are newly generated.

JP 2004-63825 A

  By the way, in the prior art according to Patent Document 1, when both the first and second plungers 3 and 6 are displaced under the excitation action of the first and second coils 4a and 4b, the first plunger 3 is biased. The magnetic circuit 8 and the magnetic circuit 9 that urges the second plunger 6 are configured to go around the second fixed magnetic pole 5. For this reason, the magnetic fluxes of the two magnetic circuits 8 and 9 leak to the respective magnetic circuits 9 and 8 side, respectively, and there is a problem that the magnetic efficiency is lowered.

  The present invention has been made in consideration of the above-described problems, and an electromagnetic wave capable of improving the magnetic efficiency of the magnetic circuit by suppressing the leakage of magnetic flux of the magnetic circuit that occurs in a set of solenoid parts. An object is to provide an actuator.

In order to achieve the above-mentioned object, the present invention provides an electromagnetic actuator having a set of solenoid parts and capable of displacing a moving element along an axial direction under the excitation action of the solenoid parts.
A first solenoid having a first housing, a first coil disposed inside the first housing, and a first movable core that is displaced under the excitation action of the first coil;
A second housing disposed coaxially with the first housing; a second coil disposed within the second housing; and a second movable core that is displaced under the excitation action of the second coil. A second solenoid having;
A separation portion disposed between the first solenoid and the second solenoid and made of a non-magnetic material;
It is characterized by providing.

  According to the present invention, in the electromagnetic actuator in which the solenoid portion is constituted by the first solenoid and the second solenoid, the separation portion made of a nonmagnetic material is provided between the first solenoid and the second solenoid. Therefore, the magnetic flux generated by the magnetic circuit generated by the first coil in the first solenoid is prevented from leaking to the second solenoid side by the separation unit, and similarly, the second solenoid that constitutes the second solenoid. Leakage of magnetic flux generated in the magnetic circuit under the energization action of the coil to the first solenoid side is suppressed. As a result, it is possible to increase the magnetic efficiency of the magnetic circuit generated by each of the first and second solenoids.

  According to the present invention, the following effects can be obtained.

  That is, by providing a separation part made of a non-magnetic material between the first solenoid and the second solenoid that constitute the solenoid part, the magnetic flux generated by the first solenoid under the energization action can be applied to the first solenoid. 2 is suppressed from leaking to the solenoid side, and magnetic flux generated by the second solenoid is suppressed from leaking to the first solenoid side. Therefore, the magnetism in the first and second solenoids is suppressed. The magnetic efficiency of the circuit can be increased.

  Preferred embodiments of the electromagnetic actuator according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates an electromagnetic actuator according to an embodiment of the present invention.

  As shown in FIGS. 1 to 3, the electromagnetic actuator 10 is disposed inside a casing 16 composed of first and second housings 12 and 14 and the first and second housings 12 and 14. A solenoid part 18, an end cover 20 that closes the opening end of the casing 16, and a separation holder (separation part) 22 disposed between the first housing 12 and the second housing 14 are included.

  The first and second housings 12 and 14 are formed in a bottomed cylindrical shape having a substantially U-shaped cross section, and each has a predetermined length along the axial direction (directions of arrows A and B).

  The first housing 12 is formed in a cylindrical shape having the same diameter, and a first coil 24 that constitutes the solenoid portion 18 is disposed in the first housing 12. The bottom portion 12a is provided. The first housing 12 is disposed such that the bottom 12a is on the second housing 14 side (arrow A direction).

  Further, a first hole portion 28 through which a first plunger (first movable core) 26 constituting the solenoid portion 18 is inserted is formed in the center portion of the bottom portion 12a.

  On the other hand, the other end of the first housing 12 opens in a direction away from the second housing 14 (arrow B direction) and is closed by a disc-shaped end cover 20. An insertion hole 34 is formed in the center portion of the end cover 20 so as to penetrate along the axial direction and insert a shaft 32 of the solenoid portion 18 described later.

  The second housing 14 is formed in a cylindrical shape having the same diameter, and a second coil 36 constituting the solenoid portion 18 is disposed inside the second housing 14. It has a bottom 14a extending in the direction. A second hole portion 40 through which a part of the fixed core 52 of the solenoid portion 18 is inserted is formed in the center portion of the bottom portion 14a.

  On the other hand, the other end of the second housing 14 opens toward the first housing 12 (in the direction of arrow B).

  The solenoid part 18 is provided inside the first housing 12, and a synthetic resin first bobbin 42 around which the first coil 24 is wound and a synthetic resin surrounding the outside of the first bobbin 42. A first solenoid 18a having a first cover 44 made of metal, a first plunger 26 that is displaceable in the axial direction inside the first bobbin 42, and an inner part of the second housing 14, A second bobbin 46 made of synthetic resin with the second coil 36 wound around the outer peripheral surface, a second cover 48 made of synthetic resin surrounding the outside of the second bobbin 46, and the inside of the second bobbin 46 A second solenoid 18b having a second plunger (second movable core) 30 provided so as to be displaceable along the axial direction is connected to the bottom 14a of the second housing 14 via a cap nut 50. A fixed core 52, a guide body 54 that is disposed on the inner peripheral side of the first and second bobbins 42, 46 and guides the first and second plungers 26, 30 to be displaceable, and the first plunger 26 And a shaft 32 connected to the second plunger 30.

  The first and second bobbins 42 and 46 are formed with first enlarged diameter portions 56a and 56b and second enlarged diameter portions 58a and 58b, respectively, which are radially expanded at both ends thereof. The diameter portions 56a, 56b and the second enlarged diameter portions 58a, 58b are covered with the overhang portions 60a, 60b of the first and second covers 44, 48.

  Further, through holes 64a and 64b penetrating along the axial direction are formed at substantially central portions of the first and second bobbins 42 and 46, respectively. A cylindrical guide body 54 is disposed in the through hole 64 a in the first bobbin 42, and a part of the guide body 54 and the guide body 54 are disposed in the through hole 64 b in the second bobbin 46. A fixed core 52 connected to the end of each is disposed.

  An elastic member 66 such as an O-ring is provided on the projecting portions 60a and 60b of the first and second covers 44 and 48 through annular grooves on the side surfaces facing the bottom portions 12a and 14a of the first and second housings 12 and 14. The elastic members 66 are respectively attached to the bottom portions 12a and 14a.

  Further, elastic members 68 such as O-rings are mounted on the inner peripheral sides of the overhang portions 60a and 60b, and are in contact with the outer peripheral surface of the guide body 54.

  As a result, the first bobbin 42 is elastically sandwiched between the bottom 12a of the first housing 12 and the enlarged diameter portion 72 of the guide body 54 described later, and the second bobbin 46 is connected to the bottom 14a of the second housing 14. Since it is elastically held between the ring-shaped second holder 104 described later, it is possible to prevent the first and second bobbins 42 and 46 from rattling in the axial direction and to be positioned. It becomes.

  The guide body 54 has a substantially constant diameter, and is formed at a cylindrical guide portion 70 into which the first and second plungers 26 and 30 are inserted, and an end portion of the guide portion 70. And an enlarged diameter portion 72 having an enlarged diameter. The guide body 54 is disposed such that the guide portion 70 is on the second housing 14 side (in the direction of arrow A) and the enlarged diameter portion 72 is on the first housing 12 side (in the direction of arrow B). Is fixed to the fixed core 52. Further, the enlarged diameter portion 72 is formed to be approximately the same as the outer diameter of the first cover 44 and is disposed between the end portion of the first cover 44 and the end cover 20.

  The first plunger 26 is formed in a cylindrical shape from a magnetic metal material, and is displaceably provided inside a guide body 54 facing the first coil 24. The first plunger 26 extends along the axial direction, and includes a main body 76 having a shaft hole 74 through which a shaft 32 to be described later is inserted, and the main body 76 on the end cover 20 side (arrow B direction). And a flange portion 78 formed with an enlarged diameter at the end portion. The shaft hole 74 penetrates the inside of the main body portion 76 along the axial direction and is formed with substantially the same diameter.

  The flange portion 78 is disposed so as to be between the enlarged diameter portion 72 of the guide body 54 and the end cover 20, and the flange portion 78 and the enlarged diameter portion 72 are arranged with a guide groove therebetween. 1 Return spring 82 is interposed. The first return spring 82 biases the first plunger 26 in a direction away from the fixed core 52 (arrow B direction) via the flange portion 78.

  The second plunger 30 is made of a magnetic metal material, and is provided inside the guide body 54 facing the second coil 36 so as to be displaceable. The second plunger 30 is formed with a screw hole 84 at one end facing the first plunger 26, and a threaded portion 86 of the shaft 32 inserted through the first plunger 26 is screwed together. Thereby, the 2nd plunger 30 and the shaft 32 are connected so that it may become coaxial. Further, the other end portion of the second plunger 30 is disposed so as to face the fixed core 52, and a tapered portion 88 having a diameter gradually reduced toward the fixed core 52 side (arrow A direction) is formed. The tapered portion 88 is formed in a tapered shape, and a second return spring 90 is interposed between the tapered portion 88 and the fixed core 52 at its end.

  The second plunger 30 is formed to have substantially the same diameter as the first plunger 26 and is guided along the guide portion 70 of the guide body 54 together with the first plunger 26 so as to be displaceable.

  The fixed core 52 is formed in a columnar shape made of a magnetic metal material, and has a threaded portion 92 protruding from a substantially central portion at one end thereof, and a tapered portion 88 of the second plunger 30 at the other end. Correspondingly, a concave portion 94 that is recessed in a tapered shape is formed.

  The concave portion 94 is formed so as to gradually increase in diameter toward the second plunger 30 side (arrow B direction), and the second return spring 90 interposed between the end portion of the second plunger 30 is: The second plunger 30 is biased in a direction (arrow B direction) in which the second plunger 30 is separated from the fixed core 52.

  Further, the outer diameter of the fixed core 52 is formed by slightly reducing the diameter of the other end portion of the fixed core 52, and the guide portion 70 of the guide body 54 is formed in the reduced diameter portion 96 that is recessed inward in the radial direction. Installed and fixed. That is, one end of the guide body 54 is closed by the fixed core 52 that is fixed. As a result, the outer peripheral surface of the fixed core 52 to which the guide body 54 is fixed is held in contact with the inner peripheral surface of the second bobbin 46.

  The fixed core 52 is inserted into the second hole 40 of the second housing 14 through the threaded portion 92, and a washer 98 is inserted into the threaded portion 92 from the outside of the second housing 14. The nut 50 is fixed to the bottom portion 14a of the second housing 14 by screwing.

  The shaft 32 is made of a nonmagnetic material, is inserted into the shaft hole 74 of the first plunger 26, and is connected to the second plunger 30 side (in the direction of arrow A) via a screw portion 86 formed at one end. Connected to the second plunger 30. Further, on one end portion side of the shaft 32, a flange portion 100 having a radially increased diameter is provided in the vicinity of the screw portion 86, and the diameter of the flange portion 100 is the outer diameter of the first and second plungers 26 and 30. And the flange portion 100 is disposed between the first plunger 26 and the second plunger 30.

  On the other hand, the other end of the shaft 32 is inserted into the insertion hole 34 of the end cover 20 and protrudes from the end surface of the end cover 20 to the outside.

  The separation holder 22 is formed in a disk shape having a predetermined thickness from a nonmagnetic material, and is disposed between the first housing 12 and the second housing 14. The inner peripheral surface of the separation holder 22 abuts on the guide portion 70 of the guide body 54 and is disposed coaxially with the first and second housings 12 and 14.

  In addition, a ring-shaped first holder 102 whose outer diameter is substantially the same as the inner diameter of the first housing 12 is fitted and inserted coaxially with the first housing 12 at the other end of the first housing 12. A ring-shaped second holder 104 whose outer diameter is substantially the same as the inner diameter of the second housing 14 is fitted into the other end of the second housing 14 coaxially with the second housing 14. At this time, the first holder 102 is disposed between the enlarged diameter portion 72 of the guide body 54 and the end cover 20, and one end face thereof is adjacent to the end face of the enlarged diameter portion 72 and is fixed, for example. The second holder 104 is sandwiched between the overhanging portion 60 b of the second cover 48 and the separation holder 22.

  The electromagnetic actuator 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and action and effects thereof will be described.

  In the off state where both the first and second coils 24 and 36 constituting the solenoid unit 18 are not energized, the elastic force of the first and second return springs 82 and 90 is shown in FIG. The first and second plungers 26 and 30 are biased in the direction away from the fixed core 52 (in the direction of arrow B) (the tip position of the shaft 32 is the first position).

  First, by energizing a power source (not shown) and energizing the first coil 24, the first solenoid 18a constituting the solenoid unit 18 is excited and turned on, and the first magnetic circuit C as shown in FIG. appear. The first magnetic circuit C has a magnetic flux that returns to the first housing 12 through the first housing 12, the first holder 102, and the first plunger 26 in this order.

  The first plunger 26 is attracted toward the fixed core 52 (in the direction of arrow A) against the elastic force of the first return spring 82 by the electromagnetic force generated by the first magnetic circuit C. Accordingly, the flange portion 100 of the shaft 32 is pressed toward the fixed core 52 side (in the direction of arrow A) under the displacement action of the first plunger 26, and the second plunger 30 is moved together with the flange portion 100 to the second return spring. It is displaced toward the fixed core 52 (in the direction of arrow A) against the elastic force of 90. At this time, the first and second plungers 26 and 30 are guided so as to be displaced in a straight line along the guide portion 70 of the guide body 54 disposed on the outer peripheral side thereof.

  The first plunger 26 is displaced to a position where the flange portion 78 of the first plunger 26 comes into contact with the enlarged diameter portion 72 of the guide body 54 and stops (the tip position of the shaft 32 becomes the second position) ( (See FIG. 2).

  Further, by energizing the second coil 36 of the second solenoid 18b in addition to the first coil 24 of the first solenoid 18a, as shown in FIG. 3, the second housing 14, the second holder 104, the second coil 2 A second magnetic circuit D having a magnetic flux returning to the second housing 14 through the plunger 30 and the fixed core 52 in sequence is newly generated.

  As a result, the second plunger 30 is sucked by a suction force generated between the second plunger 30 and the taper portion 88 is displaced toward the concave portion 94 of the fixed core 52 and comes into contact with the inner wall surface of the concave portion 94. (See FIG. 3). In this case, since the flange portion 78 of the first plunger 26 abuts against the enlarged diameter portion 72 of the guide body 54 and the displacement toward the fixed core 52 is restricted, only the second plunger 30 together with the shaft 32 is restricted. Displacement toward the fixed core 52 side (direction of arrow A).

  That is, the flange portion 100 of the shaft 32 is separated from the end surface of the first plunger 26, and a clearance is formed between the flange portion 100 and the end surface of the first plunger 26 (the tip position of the shaft 32 is the first position). 3).

  Next, when the supply of current to the second coil 36 is stopped, the attractive force toward the fixed core 52 (in the direction of the arrow A) by the second magnetic circuit D is extinguished, and the second return spring 90 generates the first force. 2 The plunger 30 is displaced in a direction away from the fixed core 52 (arrow B direction). As a result, the second plunger 30 is displaced together with the shaft 32 toward the first plunger 26 (in the direction of arrow B), and the flange portion 100 of the shaft 32 comes into contact with the end surface of the first plunger 26 and stops (the shaft 32 is the second position). In this case, since the first plunger 26 is urged toward the fixed core 52 (in the direction of arrow A) under the excitation action of the first coil 24, the first plunger 26 is displaced toward the end cover 20 side. There is nothing.

  Further, when the supply of current to the first coil 24 is stopped, the attractive force of the first plunger 26 toward the fixed core 52 by the first magnetic circuit C is also extinguished, and the first return spring 82 generates the first force. The plunger 26 is further displaced toward the end cover 20 side (arrow B direction). As a result, the flange portion 78 of the first plunger 26 comes into contact with the end cover 20 and stops (the tip position of the shaft 32 becomes the first position).

  As described above, it is possible to obtain three positions of the tip end of the shaft 32. As a result, the operating stroke of the shaft 32 can be set to a long stroke. For example, when the flow rate is controlled at the tip of the shaft 32, the flow rate can be controlled in two stages. It becomes possible to control with high accuracy.

  Here, in the present embodiment, a separation holder 22 made of a nonmagnetic material is interposed between the first housing 12 provided with the first solenoid 18a and the second housing 14 provided with the second solenoid 18b. Therefore, the magnetic flux of the first magnetic circuit C generated by the first solenoid 18a is prevented from leaking to the second solenoid 18b (in the direction of arrow A), and similarly generated by the second solenoid 18b. Thus, the magnetic flux of the second magnetic circuit D is prevented from leaking toward the first solenoid 18a (in the direction of arrow B).

  As described above, in the present embodiment, the first solenoid 18a and the second solenoid 18b constituting the solenoid unit 18 are magnetically separated from each other by the separation holder 22 made of a nonmagnetic material, whereby the first and second solenoids 18a and 18b are separated from each other. The magnetic flux of the first and second magnetic circuits C, D generated by the second solenoids 18a, 18b is prevented from leaking to the first and second magnetic circuits C, D side by the separation holder 22. Therefore, it is possible to increase the magnetic efficiency in the first and second magnetic circuits C and D, respectively.

  Note that the electromagnetic actuator according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

It is a whole longitudinal cross-sectional view which shows the structure of the electromagnetic actuator which concerns on embodiment of this invention. FIG. 2 is a longitudinal sectional view showing a state in which the first coil is excited and the first and second plungers are displaced toward the fixed core side in the electromagnetic actuator of FIG. 1. FIG. 3 is a longitudinal sectional view showing a state where the second coil is excited in addition to the first coil and the first and second plungers are further displaced toward the fixed core side in the electromagnetic actuator of FIG. 2. It is sectional drawing which shows the structure of the electromagnetic actuator which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electromagnetic actuator 12 ... 1st housing 14 ... 2nd housing 16 ... Casing 18 ... Solenoid part 18a ... 1st solenoid 18b ... 2nd solenoid 20 ... End cover 22 ... Separation holder 24 ... 1st coil 26 ... 1st plunger 30 2nd plunger 32 ... shaft 36 ... 2nd coil 42 ... 1st bobbin 44 ... 1st cover 46 ... 2nd bobbin 48 ... 2nd cover 52 ... fixed core 54 ... guide body 70 ... guide part 72 ... enlarged diameter part 74 ... shaft hole 76 ... main body 78 ... flange 82 ... first return spring 88 ... taper 90 ... second return spring 94 ... recess 102 ... first holder 104 ... second holder

Claims (1)

In an electromagnetic actuator having a set of solenoid parts and capable of displacing the moving element along the axial direction under the excitation action of the solenoid parts,
A first solenoid having a first housing, a first coil disposed inside the first housing, and a first movable core that is displaced under the excitation action of the first coil;
A second housing disposed coaxially with the first housing; a second coil disposed within the second housing; and a second movable core that is displaced under the excitation action of the second coil. A second solenoid having;
A separation portion disposed between the first solenoid and the second solenoid and made of a non-magnetic material;
An electromagnetic actuator comprising:

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