KR20070006601A - Electromagnetic actuator - Google Patents

Abstract

An electronic actuator is provided to maintain a movable shaft in a protruding state or retracting state, without supplying an electric current to a coil, by installing a permanent magnet around a flange. An electronic actuator includes a movable shaft(21) made of a magnetic material and coaxially reciprocating in both directions, and a coil(28) installed around the movable shaft. A flange(26) is formed on one end of the movable shaft, and a permanent magnet(36) is installed to an outside of the flange. The movable shaft is moved in either of directions by a magnet force of the permanent magnet. The permanent magnet is formed in a circular shape, and magnetic poles of the permanent magnet are formed in a moving direction of the movable shaft.

Description

Electronic actuator {ELECTROMAGNETIC ACTUATOR}

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the principal part in the retracted state of the movable shaft of embodiment of the electromagnetic actuator which concerns on this invention.

FIG. 2 is a view similar to FIG. 1 showing a main portion in a protruding state of the movable shaft of FIG. 1. FIG.

Explanation of the sign

3 Electronic Actuator

21 movable shaft

26 Sunshade

27 coil retaining member

28 coil

33 Back York

35 York

35a inner edge

36 permanent magnets

Japanese Patent Application Laid-Open No. 08-128556

The present invention relates to an electronic actuator that is compact and desirable for magnetic retention.

Background Art Conventionally, it is known to apply an electromagnetic valve using an electromagnetic actuator that opens and closes a flow path by turning on and off energization of a coil (see Patent Document 1, for example).

In such a solenoid valve, for example, in the non-energized state in which the coil of an electromagnetic actuator is not energized, it is formed so that a valve body may seat on a valve seat and block a flow path by the elastic force of an elastic support spring, When the current is energized, the valve body can resist the elastic force of the elastic support spring so that the valve body can be separated from the valve seat by the suction force of the electromagnet to open the flow path.

However, in the conventional solenoid valve, in order to maintain the open state of the valve which opened the flow path, there existed a problem that the energized state with respect to a coil must be maintained.

In addition, in response to such a problem, the movable shaft (plunger) is reciprocated in both directions along the axial direction by switching the direction of the current passing through the coil, and the suction force by the magnetic force of the permanent magnet is not applied to the coil. By using, it is possible to think of a configuration in which both the open state and the closed state of the valve by the movable shaft, that is, the self-maintaining both of the open state and the shutoff state of the flow path, are maintained. There is a problem in that permanent magnets must be provided on both sides of the movable shaft in the axial direction, and the electromagnetic actuator, and further the solenoid valve, becomes large.

This invention is made | formed in view of this point, Comprising: It aims at providing the compact and self-sustainable electronic actuator.

In order to achieve the above-described object, a characteristic of the electromagnetic actuator according to the present invention is an electromagnetic actuator having a movable shaft formed by a magnetic body and installed reciprocally in both directions along the axial direction, and a coil provided outside the movable shaft. As a shading portion is formed at one end side of the movable shaft, a permanent magnet is provided outside the shading portion, and the movable shaft is sucked in one of the moving directions of the movable shaft by the magnetic force of the permanent magnet. It is in a point.

In the electromagnetic actuator according to the present invention, it is preferable that the permanent magnet is formed in an annular shape, and the magnetic poles are arranged along the moving direction of the movable shaft, and the pair of yokes formed in the annular shape is the permanent. While the magnets are arranged to face each other, it is preferable that the inner circumferential edges of these yokes are arranged to face each other with the outer circumferential edges of the shade portion interposed therebetween. Moreover, it is preferable that the base end of the said shading part is formed thicker than the outer peripheral part.

Moreover, in the electromagnetic actuator which concerns on this invention, it is preferable that a back yoke is provided in the outer side of the said coil, and this back yoke is formed so that the outer side of the permanent magnet may be enclosed.

To practice the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, embodiment which shows this invention on drawing is demonstrated.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the principal part of embodiment of the electromagnetic actuator which concerns on this invention.

As shown in detail in FIG. 1, the electromagnetic actuator 3 has a movable shaft (plunger) 21 formed of a magnetic material, for example, a workpiece of free cutting pure iron.

As shown in FIG. 1, the movable shaft 21 has the axial body 21a formed on the circumference, and is formed in diameter lower than the outer diameter of the axial body 21a in the lower end shown below this axial body 21a. The valve operating portion 22 is integrally formed. In addition, the end surface of the valve operation part 22, that is, the lower end surface of the movable shaft 21 is the valve contact surface 24.

In the vicinity of the valve actuating portion 22 of the shaft main body 21a, and in a substantially central portion in the axial direction, an almost annular sliding moving portion 25 is formed. The outer diameter of these sliding moving parts 25 is formed to be equal to or slightly larger than the outer diameter of the valve operating part 22.

In the vicinity of the upper end part shown above of FIG. 1 of the said shaft main body 21a, the annular shading part 26 formed in larger diameter than the outer diameter of the sliding movement part 25 is formed. The base end portion 26a located at the connection portion with the movable shaft 21 of the shade portion 26 is formed so that its size in the axial direction is larger than the size in the axial direction of the shade portion 26. That is, the base end 26a of the shading part 26 is formed thicker than the outer peripheral part.

On the outer side of the movable shaft 21, a coil holding member 27 formed integrally with a nonmagnetic material, for example, a resin molded article such as PPS is provided. This coil holding member 27 is for arranging the coil 28 for reciprocating the movable shaft 21 in the vertical direction shown in the up and down direction of FIG. 1 which is bidirectional along the axial direction. The outer circumferential surface of 25 has a normal holding body 29 having a sliding movement hole in sliding contact. And the lower end part of the axial direction shown below of FIG. 1 of the holding | maintenance main body 29 is formed integrally with the annular lower flange 30 extended radially outward, and the axial direction of the holding main body 29 is carried out. At the upper end shown in FIG. 1, an annular upper flange 31 extending radially outward is integrally formed. In addition, the outer diameter of each of the lower flange 30 and the upper flange 31 is formed larger than the outer diameter of the coil 28, and the space | interval between the opposing surface of the lower flange 30 and the upper flange 31 is carried out. Silver is slightly larger than the length of the coil 28 in the axial direction. And in the recess space formed by each opposing surface of the lower flange 30 and the upper flange 31 which oppose each other, and the outer peripheral surface of the holding body 29 located between these opposing surfaces, 2 of FIG. The coil 28 shown by a dashed-dotted line is wound so that it may be substantially cylindrical as a whole.

On the outer periphery of the upper end surface located in the axially outer side of the upper flange 31, a large diameter ordinary portion 32 is integrally formed upward along the axial direction. This large diameter normal part 32 is extended toward the upper part of FIG. 1 which is one end side of an axial direction from the upper end part of the upper flange 31 so that it may become coaxial with the holding main body 29. As shown in FIG. And the upper end part of the cylindrical back yoke 33 provided in the outer side of the coil 28 is fixed to the most part except the upper end side of the outer periphery of the large diameter normal part 32. In addition, the lower end of the back yoke 33 is fixed to the mounting groove 34 formed near the outer periphery of the inner end surface of the lower flange 30.

The back yoke 33 is formed of a magnetic material, for example, a workpiece of free cutting pure iron, similarly to the movable shaft 21.

Inside the large diameter normal part 32 of the said coil holding member 27, the upper and lower pair of yokes which consist of the upper yoke 35A arrange | positioned above FIG. 1, and the lower yoke 35B arrange | positioned below FIG. (35) (35 denotes the upper yoke 35A and the lower yoke 35B.) Are provided at intervals. These yoke 35 is formed almost entirely annularly by the workpiece of the free cutting pure iron similarly to the magnetic body, for example, the back yoke 33. Moreover, the both ends of the axial direction of the permanent magnet 36 formed in the substantially annular form are sandwiched between the opposing surfaces of both yoke 35. As shown in FIG.

In other words, the pair of yokes 35 formed in an annular shape are disposed to face each other with the permanent magnet 36 interposed therebetween.

Each of the inner circumferential edge portions 35a of the both yoke 35 extends toward the inside of the both yoke 35 along the axial direction, and is disposed to face each other with the outer circumferential edge portion of the shade portion 26 interposed therebetween. have.

Therefore, the permanent magnet 36 is provided on the outer side of the shade 26, and by the magnetic force of the permanent magnet 36, the shade 26, and further, the movable shaft 21 in any one direction of movement. Suction, that is, it can suck in the direction which protrudes shown in the downward direction of FIG. 1, or the direction which pulls in upper direction of FIG.

The permanent magnet 36 sandwiched between the yokes 35 is a direction in which the shading portion 26 and the movable shaft 21 are projected in the axial direction below the one shown in FIG. 1 by the magnetic force. Or it sucks and hold | maintains in the drawing direction shown above of FIG. 1, and is formed in substantially annular as a whole. And the permanent magnet 36 is magnetized in the axial direction, and the magnetic pole is provided along the up-down direction of FIG. 1 which is the moving direction of the movable shaft 21. As shown in FIG. For example, the upper end side of the permanent magnet 36 is formed as the S pole, and the lower end side is formed as the N pole. In addition, the permanent magnet 36 is arranged such that its inner circumference faces the outer circumference of the shade 26.

An upper case 37 integrally formed with a non-magnetic material, for example, a resin molded article such as PPS, is fixed to an upper end portion of the outer circumference of the large diameter portion 32. In addition, the upper case 37 is formed by the double bottom which has a substantially bottom which opened the lower end side shown below in FIG. 1, and the inner surface of the outer cylinder part 37a located in the radial direction outer side of the large diameter normal part 32 is shown. It is stuck to the upper part of the outer circumference. In addition, the lower end surface of the inner cylinder part 37b located in the radially inner side of the upper case 37 abuts on the upper end surface of the upper yoke 35A located above FIG. 1 in the upper and lower pair of yokes 35. The upper surface of the movable shaft 21 is in contact with the inner surface of the inner cylinder portion 37b while restricting the maximum movement position above the movable shaft 21 when the movable shaft 21 moves upward. An annular cushion 38 formed by a cushioning material such as anti-vibration rubber for absorbing the shock when it is used is mounted. In addition, a through hole 39 having a size substantially the same as the inner diameter of the cushion 38 is formed at the center of the upper case 37, and the through hole 39 is movable with the movable shaft 21 downward. In a state, it is an air vent which can enter outside air.

Therefore, in the electromagnetic actuator 3 of this embodiment, the coil 28 is provided in the lower inner side of the back yoke 33 formed by the magnetic body, and the movable shaft 21 formed by the magnetic body inside this coil 28 is provided. ) Is provided on the lower side. Further, a pair of yokes 35 are provided inside the back yoke 33 so as to be located above the coil 28 in the axial direction, and the permanent magnets 36 are provided between the pair of yokes 35. Is installed. And the sunshade 26 of the movable shaft 21 is provided inside the permanent magnet 36, and the inner circumferential edges of the pair of yokes 35 on both sides of the outer circumferential edge of the sunshade 26 35a) is installed. In other words, the inner circumferential edge portions 35a of the pair of yokes 35 are provided to face each other with the outer circumferential edge portions of the sun shade portion 26 interposed therebetween.

In addition, the electromagnetic actuator 3 of this embodiment changes the direction of the electric current supplied to the coil 28, and changes the polarity of the upper end part of the movable shaft 21 to S pole, N pole, S pole, N pole. The polarity of the lower end of the movable shaft 21 is synchronized with the switching of the polarity of the upper end in order of N pole, S pole, N pole, S pole. It can be switched in the order of. As a result, the movable shaft 21 can be reciprocated in both directions of the direction which protrudes downward of FIG. 1 along the axial direction, and the direction which draws upward of FIG.

Next, the effect | action of this embodiment which consists of a structure mentioned above is demonstrated.

According to the electromagnetic actuator 3 of this embodiment, by changing the direction of the electric current supplied to the coil 28, the direction which protrudes below the FIG. 1 along the axial direction, and the upper direction of FIG. As a simple configuration which can reciprocate in both directions of the drawing-in direction and arrange | position the permanent magnet 36 outside the shading part 26 in the non-energization state which does not energize the coil 28, By the magnetic force of the permanent magnet 36, the movable shaft 21 can be self-held in any one of the moving directions of the movable shaft 21, ie, the direction in which it protrudes or the direction in which it pulls in.

Therefore, according to the electromagnetic actuator 3 of this embodiment, a compact and self-holding thing can be obtained easily.

In addition, FIG. 1 has shown the pulling-in state of the movable shaft 21. As shown in FIG. In addition, the protrusion state of the movable shaft 21 is shown in FIG.

Moreover, according to the electromagnetic actuator 3 of this embodiment, since the permanent magnet 36 is annularly formed and the magnetic pole is provided along the moving direction of the said movable shaft 21, the movable shaft ( It is possible to easily and surely hold the magnet 21 in the protruding direction or the pulling direction.

In addition, according to the electromagnetic actuator 3 of the present embodiment, the pair of yokes 35 formed in an annular shape are disposed to face each other with the permanent magnet 36 interposed therebetween, and the inner circumferential edge portion of these yokes 35. Since 35a is arrange | positioned facing the outer peripheral edge part of the shading part 26, it can suction efficiently in the direction which protrudes or draws in the direction which moves the movable shaft 21 by the magnetic force of the permanent magnet 36. As shown in FIG. have.

Moreover, according to the electromagnetic actuator 3 of this embodiment, since the base end part 26a of the shade part 26 is formed thick, the distance of the inner peripheral edge part 35a of the yoke 35 and the shade part 26 is Since is shortened, the suction force at the time of suctioning in the direction which protrudes or pulls in the shading part 26 and further the movable shaft 21 by the magnetic force of the permanent magnet 36 can be made strong.

Moreover, according to the electromagnetic actuator 3 of this embodiment, the back yoke 33 is provided in the outer side of the coil 28, and this back yoke 33 is formed so that the outer side of the permanent magnet 36 may be enclosed. As a result, the missing magnetic flux can be reduced, and the magnetic force of the permanent magnet 36 can be reduced by the magnetic field formed by the back yoke 33. As a result, when the movable shaft 21 is reciprocated along the axial direction, the magnetic force of the permanent magnet 36 which acts in the direction which hinders the movement of the movable shaft 21 can be made small. That is, the shading | molding part 26 of the movable shaft 21 with respect to the inner peripheral edge part 35a of a pair of yoke 35 can be made into the balanced state which is easy to space apart, and is easy to adsorb | suck.

According to the electromagnetic actuator 3 of this embodiment, the movement and the downward direction of the movable shaft 21 to the up direction (retraction direction) by switching the energization direction with respect to the coil 28 of the electromagnetic actuator 3 is performed. The movement in the direction of protruding can be easily and reliably switched selectively, and the holding in the upper position (retracted state) of the movable shaft 21 is not performed while energizing the coil 28. , Selectively enabling any one state of holding in the lower position (protrusion state).

The electronic actuator of the present invention can be used in various kinds of controllers.

In addition, this invention is not limited to embodiment mentioned above, Various changes are possible as needed.

According to the electromagnetic actuator according to the present invention, the electromagnetic actuator is provided with a shading portion at one end of the movable shaft and a permanent magnet is provided outside the shading portion. You can keep yourself sleeping. Therefore, according to the electromagnetic actuator of the present invention, it is possible to easily and reliably obtain a compact and self-maintainable.

Claims (5)

An electromagnetic actuator having a movable shaft formed by a magnetic body and installed to reciprocate in both directions along the axial direction, and a coil provided outside the movable shaft, A shading portion is formed at one end side of the movable shaft, and a permanent magnet is provided outside the shading portion. And the movable shaft is formed so as to be attracted in any one direction of movement of the movable shaft by the magnetic force of the permanent magnet. The method of claim 1, The permanent magnet is formed in an annular shape, and its magnetic poles are arranged along the moving direction of the movable shaft. The method of claim 2, A pair of yokes formed in an annular shape are disposed to face each other with the permanent magnet interposed therebetween, and the inner circumferential edge portions of these yoke are disposed to face each other with an outer circumferential edge portion of the shade portion. The method of claim 3, wherein The proximal end of the sunshade is formed thicker than the outer peripheral portion. The method of claim 4, wherein A back yoke is provided outside the coil, and the back yoke is formed to surround the outside of the permanent magnet.

Images