JPH07335434A - Solenoid plunger actuator - Google Patents

Abstract

PURPOSE:To provide a plunger solenoid actuator having a simple latch structure consuming no power in the latch time and hardly making failure. CONSTITUTION:Within a solenoid plunger actuator provided with a protrusion 12 in the axial direction in the inner diametrical side of a stator having covering parts on both ends, the other protrusions 13, 14 in the axial direction protruding from the central part in the axial direction of the covering parts, permanent magnets 15, 16 magnetized in the axial direction provided on these axial directional protrusions 13, 14, a movable piece 2 is driven by exciting coils 31, 32 arranged in a stator through the intermediary of the protrusion 12 in the axial direction so as to latch up the movable piece 2 by magnetic attraction using the magnetic flux generated by the permanent magnets 15, 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid actuator in which the mover reciprocates by an electromagnetic force and the mover is latched at positions at both ends of a moving range, such as the structure of a movable part of an electromagnetic switch. Concerning the structure of.

[0002]

2. Description of the Related Art A solenoid actuator is a device for passing a current through an exciting coil wound like a solenoid to excite a magnetic circuit to generate a magnetic flux and linearly move a mover by the generated magnetic attraction force. It has a so-called latch structure for fixing the mover at the positions of both ends thereof.

[0003]

As a structure for latching the mover, there is a structure in which a current is continuously passed through the exciting coil and fixed by a magnetic attraction force, or a structure in which a mechanical latch mechanism is provided. However, in the case of the former magnetic attraction, if the latch period is long, the power consumed cannot be ignored,
In particular, when the exciting coil is excited by a battery, there is a problem that the battery is consumed quickly. In addition, since the mechanical latch mechanism requires a complicated mechanical structure, the solenoid actuator becomes large in size, and there is a problem that it is likely to cause a failure.

An object of the present invention is to solve the above-mentioned problems, to have a simple structure and to consume no power during the latch period,
Another object of the present invention is to provide a solenoid actuator having a latch structure that is resistant to failure.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a solenoid actuator has a cylindrical frame having a lid portion at both ends and a cylindrical portion connected to the lid portion. A cylinder provided with a radial projecting portion projecting toward the inner diameter side in the axial center portion, and a permanent magnet axially projecting from the center of the lid portions at both ends toward the inner side of the cylindrical portion and magnetized in the axial direction. -Shaped stator made of a ferromagnetic material consisting of two axial projections, a rod-shaped shaft of a non-magnetic material that movably penetrates the center of the lids at both ends of the frame and the axial projections, and the central part of this shaft A movable element composed of a cylindrical movable element iron core fixedly attached to the first movable element, and a first movable element accommodated in the fixed element and provided in a space in the frame between one lid portion of the frame and the radial protrusion. Excitation coil of the frame It shall have an excitation coil of a second excitation coil provided in the space between the square of the lid and the radial projecting portion.

Further, the radial projections of the solenoid actuator may be arranged at intervals in the axial direction, and the magnetic circuits in the stator may be separately formed in two. In addition, an axially magnetized permanent magnet is provided between the axially protruding portion and the lid portion. In this case, it is preferable that a non-magnetic material is provided in close contact with the permanent magnet in the radial direction, and the axial projection supported by the magnetic material is arranged with a gap in the axial direction from the permanent magnet. .

Further, a permanent magnet magnetized in the axial direction is partially embedded in an end of the axially projecting portion facing the movable iron core, and a cross-sectional area of both ends of the movable iron core in the axial direction is centered in the axial direction. It should be larger than the section.

[0008]

According to the present invention, the stator has a tubular frame composed of lid portions at both ends and a cylindrical portion connecting the lid portions,
The movable part is composed of a radial protrusion that protrudes toward the inner diameter side at the axial center of the cylindrical portion and two axial protrusions that protrude axially inward from the lid portion. A rod-shaped shaft made of a non-magnetic material that movably penetrates through the center and the radial projecting portion, and a cylindrical movable iron core attached to the axially central portion of this shaft allows one axial projecting Magnetic circuit composed of a gap between the core and the movable core and a radial protrusion, and second magnetic circuit composed of a gap between the other axial protrusion and the movable core and a radial protrusion A circuit is formed. Further, by providing the first and second exciting coils in the stator in the axial direction, it becomes possible to excite each of the exciting coils forming the first and second magnetic circuits. .

Further, by forming a part of the axially protruding portion by a permanent magnet magnetized in the axial direction, a current is passed through the exciting coil to move the mover to one end of the axially protruding portion. When in the latched state, the magnetic flux generated by the permanent magnets is increased in the magnetic circuit having the smaller gap length of the gap between the mover and the axial protruding portion. As a result, a large magnetic attraction force acts on the gap to generate the latch force required to fix the position of the mover.

Further, when the latch is released, a magnetic flux in the opposite direction to the magnetic flux generated by the permanent magnet provided on the axially protruding portion is generated in the one exciting coil located on the side where the mover is latched. A current is passed to reduce the magnetic flux in the gap between the mover and the axially protruding portion, and to generate a magnetic flux in the same direction as the magnetic flux of the permanent magnet located on the non-latching side, current is applied to the other exciting coil. The magnetic flux in the air gap between the unlatched side mover and the axial projection increases and the magnetic attraction increases, and the mover moves to the other axial projection side. To be achieved.

Further, by providing two radial projections at intervals in the axial direction, the magnetic circuit on the side of the stator is completely separated.
Since it can be separated into two, the magnetic attraction force by the permanent magnet on the latched side of the mover is erased by one exciting coil, and the magnetic flux generated by the one exciting coil is influenced by the other exciting coil. Without this, the mover can be driven in the opposite direction.

Further, by disposing the permanent magnet between the lid portion and the axially protruding portion, since the mover is latched by receiving the magnetic flux of the permanent magnet through the axially protruding portion, it is arranged directly opposite to the movable element. The magnetomotive force to be generated by the exciting coil for releasing the latch can be smaller than that of the configuration described above. Furthermore, by providing the permanent magnet with a non-magnetic material and arranging the axially projecting portion through the air gap with the permanent magnet, the impact force applied to the axially projecting portion end of the movable iron core due to the movement of the mover during latching Since the non-magnetic material is relaxed and can be prevented from being directly received by the permanent magnet, damage to the permanent magnet can be prevented.

Further, since the permanent magnet is partially provided at the end of the axial protrusion, the magnetic flux generated between the permanent magnet and the movable core passes through the end surface of the axial protrusion where the permanent magnet is not provided. Since a local magnetic circuit that revolves around is formed, the magnetic attraction force becomes smaller than the configuration in which a permanent magnet is provided on the entire end portion of the axial protruding portion, and it can be applied to a solenoid actuator that does not require a large latching force. . Furthermore, by making the cross-sectional area of the central portion of the movable iron core in the axial direction smaller than the cross-sectional area of both end portions facing the axial protruding portion,
The weight of the solenoid actuator can be reduced.

[0014]

EXAMPLES The present invention will be described below based on examples.
1 and 2 are sectional views of a solenoid actuator according to a first embodiment of the present invention. The solenoid actuator shown in FIG. 1 includes a stator 1 made of a ferromagnetic material, a mover 2 and an exciting coil 3 wound in a solenoid shape. The stator 1 is a tubular frame 11 that also serves as a yoke, a radial projection 12 provided on the axially central portion of the frame 11 so as to project toward the inner diameter side, and axially attached to the lids at both ends of the frame 11. Axial protrusion 1 that protrudes
3 and 14, and axially magnetized permanent magnets 15 and 16 provided on the axial protrusions 13 and 14, respectively.

The mover 2 has a rod-shaped shaft 21 made of a non-magnetic material that penetrates through the centers of the lids at both ends of the frame 11.
A cylindrical iron core 22 coaxially fixed to the outer diameter side of the central portion of the shaft 21 in the axial direction and considerably the stator 1 and the mover 2
Both have a symmetrical structure in the axial direction. The exciting coil 3 is
It is composed of two solenoid-shaped exciting coils 31 and 32, and is provided in the space between the stator 1 and the mover 2 in the frame 11 in the axial direction via the radial protrusion 12.

A gap 41 is formed between the axial protrusion 13 and the movable iron core 22, and a gap 42 is formed between the axial protrusion 14 and the movable iron core 22. In FIG. 1, the mover 2 is in a position where the mover 2 has moved toward the left axially protruding portion 13 and stopped, and the gap 41 is small and the gap 42 is large. That is, the state is shown in which the mover 2 is fixed and latched at the left position, and the gap 41 is formed by a mechanism not shown.
The latch position is set so as to maintain a predetermined gap length.

The magnetic flux generated by the permanent magnets 15 and 16 is
Permanent magnet 1 as indicated by dashed lines 51 and 52 with arrows
5, a magnetic circuit that circulates from the axial projection 13, the gap 14, the movable core 22, the radial projection 12, the frame 11 to the permanent magnet 15, and the axial projection 1 from the permanent magnet 16.
4, a gap 42, the movable iron core 22, the radial protrusion 12, and a magnetic circuit that passes through the frame 11 and circulates to the permanent magnet 16 to form two magnetic circuits. In FIG. 1, the void 42
The magnetic flux 51 of the former magnetic circuit is larger than the magnetic flux 52 of the latter magnetic circuit because the air gap 41 has a smaller air gap length than the magnetic flux. Therefore, the mover 2 is latched and fixed on the left side. In this state, no current is flowing through any of the exciting coils 3, and no power is consumed during the latch period of the mover.

In order to release the latch and move the mover 2 to the right, a current is passed through the exciting coil 3 so that the mover 2 is given a magnetic attraction force to generate a driving force to the right. FIG. 2 is an explanatory diagram showing a magnetic flux generated by a magnetomotive force generated by passing a current through the exciting coil 3, and by passing a current through the exciting coils 31 and 32 in the directions shown in the left side of the drawing. Magnetic flux in magnetic circuit 5
3, magnetic flux 54 is generated in the right magnetic circuit. Here, the magnetic flux 53 of the left magnetic circuit is in the opposite direction to the magnetic flux 51 generated by the permanent magnet of FIG. 1, and the magnetic flux 5 of the right magnetic circuit 5
Since 4 is in the same direction as the magnetic flux generated by the permanent magnet of FIG. 1, the magnetic flux is reduced in the air gap 41 and the magnetic attraction force is reduced, and the magnetic flux is increased in the air gap 42, so the magnetic attraction force is also increased. Therefore, as shown in FIG. 2, by applying a magnetomotive force to each exciting coil 3 so that the magnetic attraction force of the air gap 42 becomes larger than the magnetic attraction force of the air gap 41, the latch of the mover 2 is released, and The mover 2 receives the driving force in the right direction in FIG. 2 and moves. By cutting off the current flowing through the exciting coil 3 at the time when the mover 2 has finished moving to the right, the mover 2 can be fixed and latched at the position on the axially protruding portion 14 side in the right direction. it can. FIG. 3 shows a sectional view of a solenoid actuator according to a second embodiment of the present invention. The difference from the first embodiment of the present invention is that the radial protrusions 12 in the first embodiment are arranged with two axial protrusions 12A and 12B spaced apart from each other. As a result, the magnetic circuits generated by the excitation coils 31 and 32 can be separated from each other, so that the magnetic flux generated by one of the excitation coils in the first embodiment including the one radial protrusion 12 is generated. It is possible to eliminate the influence of the magnetic flux generated by the other exciting coil on the magnetic circuit. Therefore, when the movable element 2 in which the left axial projection 13 is located is released from the latch and is moved to the right, the exciting coil 31 for canceling the magnetic flux of the air gap 41 by the permanent magnet 15 is cancelled. A magnetomotive force that gives a necessary driving force to the mover 2 can be arbitrarily set in the exciting coil 32 without affecting the magnetomotive force.

By the way, in the present invention, the axial protruding portion 1
The permanent magnets 15 and 16 provided on 3 and 14 are
As shown in FIGS. 1 and 3, it is located between the axial protrusions 13 and 14 and the lid of the frame 11. That is, in the configuration in which the permanent magnet 15 is arranged at the tip of the axial protruding portion 13 so as to directly face the movable element core 22 of the movable element 2, the axial protruding portion 1 is released when the movable element 2 is unlatched.
This is because a large magnetomotive force is required for the exciting coil 31 in order to eliminate the magnetic flux in the gap between the movable core 22 and the movable core 22.
In the configuration of FIG. 3 of the present invention shown in FIG. 4 and the configuration of FIG. 3 in which a permanent magnet is provided at the tip of the axially projecting portion so as to face the mover iron core, the magnetomotive force applied to the exciting coil 31 is increased. And the relation between the magnetic attraction force applied to the mover and the magnetic attraction force are shown by a solid line and a broken line, respectively. The shape of the solenoid actuator used for the calculation is 100 mm in the axial direction of the stator,
The outer diameter of the stator is 100 mm, the outer diameter of the mover iron core is 50 mm, the inner diameter of the stator and the inner diameter of the mover are 30 mm, respectively. The stator and the mover iron core are assumed to be solid iron for general structure, and the permanent magnet is a praseodymium magnet. It was done. The magnetomotive force of the exciting coil required to release the latch of the mover, that is, to reduce the magnetic attraction force, which is the force applied to the mover, to the tip of the above-mentioned axial protrusion is opposite to the mover core. In the configuration in which the permanent magnet is provided, the value is 2.2 KAT as shown by the broken line, but in the configuration in FIG. 3, it is 1.2 KAT as shown by the solid line, which is a much smaller value.

FIG. 5 is a sectional view of a solenoid actuator according to the third embodiment of the present invention. In FIG. 5, the non-magnetic members 17 and 18 made of stainless steel are coaxially fixed to the inner diameter sides of the permanent magnets 15A and 15B, and the axial protrusions 13A and 14A are axially supported by the non-magnetic members 17 and 18, and Minute gap 4 between magnets 15A and 15B
3 and 44 are provided and arranged. Mover 2 from this
Since the mechanical impact force exerted on the axial protrusions 13A and 14A due to the movement of the can be alleviated by the non-magnetic bodies 17 and 18, the permanent magnets 15A and 15B can be prevented from being damaged.

FIG. 6 is a sectional view of a solenoid actuator according to the fourth embodiment of the present invention. FIG. 7 shows A of FIG.
8A and 8B are cross-sectional views of the shaft 21 and the axial protruding portion 13B. FIG. 6 shows a solenoid actuator having a structure in which axially magnetized permanent magnets 15B and 16B are embedded at positions facing the mover iron cores 22 of the axial protrusions 13B and 14B, and are movable by a magnetic attraction force of the magnetic flux 55. The child 2 has a leftward axial projection 13
It is latched in the B position. As shown in FIG. 7, the permanent magnet 15B is arranged in a ring shape at the radial center of the end of the axial protrusion 13B, and has a structure for generating a local magnetic flux between the shaft 21 and the movable iron core 22. ing.

To release the latch, a current is passed only through the exciting coil 32 to give a magnetomotive force to generate a magnetic flux 56 in the air gap 42, and a magnetic attraction force larger than the magnetic attraction force by the permanent magnet 15B of the axial protruding portion 13B is applied. This can be done by moving the mover 2 to the right by generating it. When the mover 2 moves to the right end, by cutting off the current of the exciting coil 32, the axial protrusion 14
The mover 2 is latched by the magnetic attraction force by the magnetic flux generated by the permanent magnet 16B provided in B. In this configuration, since the magnetic circuit of the magnetic flux 55 that generates the latching force is local as described above, the magnetic attraction force is smaller than the configuration in which the permanent magnet is provided on the entire end portion of the axial protruding portion, and therefore the latching force is reduced. The magnetomotive force of the exciting coil 32 for elimination may be small.

The permanent magnet embedded in the end of the axially protruding portion may have a structure that locally circulates a magnetic flux like the magnetic flux 55 of FIG. 6 between the mover core and the axially protruding portion. Therefore, as shown in FIGS. 8 (a) and 8 (b), the axial protrusion 1
A configuration in which rectangular permanent magnets 15B are radially arranged at the end of 3B and a configuration in which they are arranged circumferentially may be used.
The shape of B is not particularly limited.

FIG. 9 is a sectional view of a solenoid actuator according to the fifth embodiment of the present invention. In FIG. 9, the outer diameter of the central portion of the movable iron core 22A is smaller than that of both ends. The magnetic attraction force generated in the gap 41 at the time of latching the shaft 21 depends on the size of the cross-sectional area of the end portion of the movable iron core 22A facing the axial protruding portions 13 and 14, so that the shaft center portion is generated. It is possible to reduce the magnetic flux to the extent that it is not affected by magnetic saturation. This makes it possible to achieve weight reduction without degrading the performance of the solenoid actuator. Further, in the present invention, the stator, the axial protruding portion and the exciting coil have a cylindrical cross section, but the cross sectional shape may be polygonal.

[0025]

As described above, according to the present invention, a part of the axial projecting portion is formed of an axially magnetized permanent magnet, and the magnetic flux generated by the permanent magnet latches the mover. In order to obtain a magnetic attraction force and release the latch to drive the mover in the opposite direction,
This is achieved by passing an electric current through the exciting coil so as to generate a magnetic flux in the direction opposite to that of the permanent magnet, so that the exciting coil is not energized during the latch period as in the conventional case, and the latching force is not applied. You don't need power to get. Further, since it does not have a complicated latch mechanism, a solenoid actuator having a simple structure can be obtained. Further, since the magnetic circuit on the side of the stator can be completely separated into two by providing two radial protrusions at intervals in the axial direction, there is no influence on the magnetic flux generated by each exciting coil. The effect that the magnitude of the driving force of the mover can be freely controlled is obtained.

Further, since the permanent magnet provided on the axially projecting portion is provided on the lid side so as not to directly face the mover core, the magnetomotive force to be generated by the exciting coil for releasing the latch is Since it is small and there is no need to generate a large magnetomotive force in the direction opposite to the magnetization direction of the permanent magnet, the fear of demagnetization and demagnetization of the permanent magnet can be avoided. Further, by providing a non-magnetic material for the permanent magnet, it is possible to mitigate the mechanical impact force of the movable iron core at the time of latching and prevent the permanent magnet from being damaged.

Further, since the permanent magnet is partially provided at the end of the axially protruding portion, the magnetomotive force applied to the exciting coil for eliminating the latch can be small, and the drive control of the mover is easy. Therefore, it can be applied to a solenoid actuator that does not require a large latching force. Furthermore, by making the cross-sectional area of the axial center portion of the movable iron core smaller than the cross-sectional area of both end portions facing the axial protrusion portion, it is possible to reduce the weight of the solenoid actuator.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram of magnetic flux generated by passing a current through the exciting coil of FIG.

FIG. 3 is a sectional view of a solenoid actuator showing a second embodiment of the present invention.

FIG. 4 is a graph showing a relationship between a magnetomotive force applied to an exciting coil of a solenoid actuator and a magnetic attraction force applied to a mover.

FIG. 5 is a sectional view of a solenoid actuator showing a third embodiment of the present invention.

FIG. 6 is a sectional view of a solenoid actuator showing a fourth embodiment of the present invention.

7 is a cross-sectional view taken along the line AA of FIG.

8 is a cross-sectional view of a shaft and an axial protruding portion of a mover showing another embodiment different from FIG. 6, where FIG. 8A shows a rectangular permanent magnet in a radial pattern and FIG. It is arranged in a circle.

FIG. 9 is a sectional view of a solenoid actuator showing a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 11 Frame 12 Radial protrusion 13 Axial protrusion 14 Axial protrusion 15 Permanent magnet 16 Permanent magnet 2 Mover 21 Axes 22 Mover core 41 Gap 42 Gap

Claims (6)

[Claims] 1. A stator composed of an axially symmetric ferromagnetic material, an axially symmetric mover movably penetrating the axial center of the stator, and a solenoid-like exciting coil arranged around the mover. In a solenoid actuator in which a current is passed through an exciting coil to excite a magnetic circuit formed by a mover and a stator, and the mover is driven in the axial direction by a magnetic attraction force, the stator has lid parts at both ends. A cylindrical frame composed of a cylindrical portion that is connected to this, a radial direction protruding portion that protrudes toward the inner diameter side at the axial center portion of this cylindrical portion, and from the center of the lid portions at both ends toward the inside of the cylindrical portion. And a cylindrical two axial projections provided with axially magnetized permanent magnets projecting in the axial direction, wherein the mover movably penetrates the center of the lids at both ends of the frame and the axial projections. With a rod-shaped shaft of magnetic material, A cylindrical mover iron core fixedly attached to the center of the frame, and an exciting coil is housed in the stator and provided in a space in the frame between one lid part of the frame and the radial protrusion. The first exciting coil,
A solenoid actuator comprising: a second exciting coil provided in a space between the other lid portion of the frame and the radial protruding portion. 2. The solenoid actuator according to claim 1, wherein the radial projections are axially spaced from each other and are generated by the first and second exciting coils housed in the stator. A solenoid actuator characterized in that each of the two is formed separately. 3. The solenoid actuator according to claim 1, wherein a permanent magnet magnetized in the axial direction is provided between the axial protruding portion and the lid portion. 4. The solenoid actuator according to claim 1 or 2, wherein a permanent magnet magnetized in the axial direction is partially embedded in an end portion of the axial projecting portion facing the movable iron core. And solenoid actuator. 5. The solenoid actuator according to claim 3, wherein a non-magnetic material is provided in close contact with the permanent magnet in the radial direction, and the axial projection supported by the non-magnetic material is in the axial direction with the permanent magnet. A solenoid actuator characterized in that it is provided with a space provided between the solenoid actuators. 6. A solenoid actuator according to any one of claims 1 to 5, wherein the movable iron core has a cross-sectional area of both axial end portions larger than a central portion in the axial direction.