JPH08237930A - Actuator - Google Patents

Abstract

PURPOSE: To make it possible to increase holding power against external force at a specified driving position without increasing power consumption nor cost. CONSTITUTION: An actuator is so structured that magnetic flux of permanent magnets 13, 14 which are installed on a fixed-side member A may flow in only two magnetic paths D1 , D2 which are formed with the permanent magnets 13 and 14, magnetic path forming means (a body yoke 1, a stator yoke 2), a stator 15, and rotor yokes 31 and 32 which are installed on a driven-side member B and there may be no other short-circuit which might cause magnetic energy loss.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator used for driving an idle speed control electromagnetic valve, for example.

[0002]

2. Description of the Related Art Conventionally, as an actuator, for example, Japanese Patent Publication No. 64-2023, page 5, pages 1-5.
There is a "rotational drive" as shown in the figure.

This "rotary driving device" (hereinafter referred to as an actuator) is a member (first device) that forms a first magnetic path.
Yoke), coil means for generating a magnetic flux in the axial direction of the first magnetic path, and the first magnetic path having a large axial width and being provided in the first magnetic path. A space in which a narrowed portion having a narrow width in the orthogonal direction is formed, a rotary permanent magnet rotatably arranged in the space and magnetized in two poles in the radial direction, and a member forming the first magnetic path are substantially Contact each other,
A ferromagnetic yoke member (second yoke) which is provided in a direction orthogonal to the rotational axis direction of the rotating permanent magnet and the axial direction of the first magnetic path to form a second magnetic path. Met.

That is, in this conventional example, a rotating permanent magnet having two poles magnetized on the rotor side is used, and the rotating permanent magnet is used as the first permanent magnet.
The magnetic resistance of the magnetic path of the rotating permanent magnet is changed by rotating in a space (long in the axial direction of the first magnetic path) formed in the magnetic path of, and the neutral stable position (both narrowed portions are A torque that returns in the connecting direction, that is, the direction in which the magnetic flux of the rotating permanent magnet is orthogonal to the axial direction of the first magnetic path) is exerted. Then, by energizing the coil means in this state, a magnetic flux is generated in the axial direction of the first magnetic path, which is a direction orthogonal to the magnetic flux of the rotating permanent magnet, and the strength of this magnetic flux (energization to the coil means is applied. The rotating permanent magnet can be rotated from the neutral stable position to an arbitrary rotation angle position and held at that position according to the magnitude of the electric current.

Further, in this conventional example, by the ferromagnetic yoke member (second yoke) forming the second magnetic path,
The magnetic resistance of the magnetic path of the rotating permanent magnet in the neutral stable position is reduced to increase the torque that returns the rotating permanent magnet to the neutral stable position, thereby increasing the torque change rate (gradient) with respect to the rotation angle of the rotating permanent magnet. That is, the holding force at a predetermined rotational position is increased.

[0006]

However, the above-mentioned conventional actuator has the following problems. That is, in the actuator of the conventional example, as described above, the rotation provided with the two-pole magnetization in the space provided in the member (first yoke) forming the first magnetic path formed of the ferromagnetic material. The permanent magnet is arranged, that is, the magnetic field formed around the rotating permanent magnet is short-circuited all around by the member (first yoke) forming the first magnetic path, and Part of the generated magnetic flux is shunted to the side of the first magnetic path having the coil means,
Since the magnetic flux applied in the direction orthogonal to the magnetic flux of the rotating permanent magnet is reduced, the change in the magnetic resistance of the magnetic field due to the rotation of the rotating permanent magnet becomes gradual, which reduces the torque change rate (gradient) with respect to the rotation angle. The holding force against the disturbance torque at the predetermined rotation position becomes small.

Therefore, the rotational position fluctuates greatly depending on the magnitude of the disturbance torque acting on the rotating permanent magnet. For example, when a valve provided in a part of the intake passage of the engine is directly driven by this actuator, a rotational torque as a disturbance acts on the rotating permanent magnet on the rotor side due to a flow force generated in the valve. By changing the rotational position, the valve opening changes, which causes a problem that hunting occurs in the engine speed.

Even if the second magnetic path is formed by the ferromagnetic yoke member, the entire circumference is short-circuited by the member (first yoke) forming the first magnetic path. No significant improvement effect can be obtained. Further, in the conventional example, instead of forming the narrowed portion, the member (first yoke) forming the first magnetic path is divided into two with some slits, so that the magnetic field around the rotating permanent magnet is divided. Although a proposal to eliminate the physical short circuit has been proposed, the first yoke divided into two by the slit is connected by the first magnetic path, so that the first magnetic path itself is magnetic to the rotating permanent magnet. Since the short-circuit path is formed, the large improvement effect cannot be obtained.

Therefore, either the coil magnetomotive force required to rotate the rotating permanent magnet is increased by increasing the value of the current passed through the coil, or a rare earth magnet having a strong magnetic force is used as the rotating permanent magnet to solve the above problems. Although it is possible to improve the point, in the former case, power consumption increases, and in the latter case, rare earth magnets are much more expensive than ferrite magnets, which leads to cost increase. Will cause problems. It should be noted that it is difficult to form a cylindrical ferrite magnet into a substantially cylindrical shape because cracks occur during the manufacturing process.

The present invention has been made by paying attention to the above-mentioned conventional problems, and enhances the holding force against external force at a predetermined drive position without increasing power consumption and cost. It is an object of the present invention to provide an actuator capable of

[0011]

In order to achieve the above object, an actuator according to claim 1 of the present invention comprises a fixed side member and a drive side member which can be driven along the fixed side member. The side member is provided with a pair of magnetic flux shunting means composed of magnetic members magnetically separated from each other along the driving direction, and each magnetic flux shunting member is provided on a surface of the fixed side member facing the magnetic flux shunting means. A stator is provided in which one end of the means faces each other with a predetermined small gap, and both magnetic flux shunting means are provided on both sides of the stator of the fixed side member in a direction substantially orthogonal to the driving direction of the drive side member. A pair of permanent magnets are provided which are magnetized in two directions such that the sides facing each other are opposite to each other and one end of each magnetic flux shunting means faces each other with a predetermined small gap, and the stator is provided with the permanent magnets. Drive side Is provided with coil means capable of generating a magnetic flux in a direction substantially orthogonal to the driving direction and controlling the magnetomotive force thereof, and the fixed side member is opposite to the side facing the respective magnetic flux shunting means in the drive side member. On the side, the magnetic path forming means that magnetically communicates between both permanent magnets and the stator is provided.

Further, in the actuator according to a second aspect of the invention, the coil means can switch the direction of the magnetic flux generated in the stator between normal and reverse directions and can control the magnetomotive force in each of the forward and reverse magnetic flux directions.

Further, in the actuator according to a third aspect, the coil means has two coils for generating magnetic flux in opposite directions in the stator, and only one coil is energized at the time of on-duty based on the duty signal. In the off-duty mode, only the other coil is energized and the duty ratio of the duty signal is variably controlled so that the magnetomotive forces in the forward and reverse magnetic flux directions generated in the stator can be controlled.

Further, in the actuator according to claim 4, the fixed side member is formed in an annular shape with both permanent magnets and the stator inside, and the drive side member is a rotatable rotor provided with both magnetic flux shunting means on the outside. The opposing surfaces of the permanent magnets of the fixed member and the stator and the magnetic flux diverting means of the driving member are formed in an arc shape concentric with the rotation axis of the rotor.

Further, in the actuator according to the fifth aspect of the invention, the opposing surfaces of the permanent magnets and the stator of the fixed side member and the magnetic flux shunting means of the drive side member are linearly formed.

[0016]

In the actuator according to claim 1 of the present invention,
With the configuration described above, when the coil means is not energized, the magnetic flux of one permanent magnet passes through the magnetic path forming means and the stator, passes through the small gap, and flows into the one magnetic flux shunting means. After that, a magnetic path is formed such that it passes through the small gap and returns to the permanent magnet, and the magnetic flux of the other permanent magnet passes through the small gap and flows into the other magnetic flux shunting means. After passing through the gap and flowing into the stator, it returns to the permanent magnet via the magnetic path forming means, which is a state in which a magnetic path is formed. Therefore, the flow directions of both magnetic paths in the stator portion are opposite to each other.

At this time, if the areas of the two small gaps formed on the facing surfaces between the magnetic flux shunting means and the stator, that is, if the cross-sectional areas of the two magnetic paths are not the same, the one with the larger magnetic path cross-sectional area is used. A magnetic resistance difference occurs in which the magnetic resistance on the side of the smaller magnetic path is larger than that on the side of the magnetic path, but the drive-side member is placed in the direction of decreasing the magnetic resistance in each of the small gaps (increasing the area). The driving force (torque or thrust) acts in the directions opposite to each other, so that both forces are evenly balanced, that is, both small forces formed on the facing surfaces between the magnetic flux shunting means and the stator. The force (return torque or return thrust) for returning the drive-side member to the neutral stable position where the area of the gap is the same is always working.

Therefore, when the coil means is not energized, the driving side member can be held at the neutral stable position. When the driving side member moves in either direction from the neutral stable position. In this case, a return force to the neutral stable position is generated in proportion to the amount of change in the magnetic resistance due to the movement, and the strength of the return force becomes the magnitude of the holding force of the drive side member against the disturbance at the predetermined drive position.

Next, when a magnetic flux in one of the directions is generated in the stator by energizing the coil means, the magnetic flux strength increases on the magnetic path side where the magnetic flux and the magnetic flux are in the same direction, while the magnetic flux is increased. Since the magnetic flux strength decreases on the side of the magnetic path in which the directions are opposite to each other, and the strength of both magnetic fluxes in both magnetic paths becomes non-uniform, the magnetic fields in both magnetic paths are the same when the small gap areas are the same. Since the resistance balance is lost, a driving force is generated to drive the driving side member to the position where the magnetic resistance is balanced again, and this driving force drives the driving side member from the neutral stable position to the predetermined position. Can be held at that position.

The magnetic fluxes of both permanent magnets flow only through the magnetic passages composed of both permanent magnets, both magnetic flux shunting means, the stator and both magnetic passage forming means, and cause magnetic energy loss as in the conventional example. Since there is no other short-circuit path, the magnetic energy of both permanent magnets can be efficiently used. Therefore, it is possible to increase the holding force against the external force at the predetermined driving position without increasing the power consumption and the cost.

Further, in the actuator according to the second aspect, when the magnetic flux is generated by the coil means in one of the forward and reverse directions with respect to the stator, the drive side member is driven in a predetermined direction from the neutral stable position, and When the magnetic flux is generated in the opposite direction to the above, the drive side member can be driven from the neutral stable position in the opposite direction to the above.

Further, in the actuator according to the third aspect of the invention, based on the duty signal, only one coil is energized during the on-duty and only the other coil is energized during the off-duty to variably control the duty ratio of the duty signal. By doing so, it is possible to control the magnetomotive forces in the forward and reverse magnetic flux directions generated in the stator, that is, the duty ratio is 50%, the drive side member is held in the neutral stable position, and the duty ratio is increased or decreased from 50%. By doing so, it is possible to drive the drive side members in mutually opposite directions about the neutral stable position.

Further, in the actuator according to the fourth aspect, the driving side member is driven in the rotation direction, and the rotation angle of the rotor can be controlled. Further, in the actuator according to the fifth aspect, the driving side member is driven in the linear direction, and the linear movement amount can be controlled.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIG. 1 is a sectional view (II line in FIG. 2) showing a rotary actuator of a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. In the figure,
A is a fixed member, and B is a driving member.

First, the fixed side member A will be described. The body yoke 1 is formed of a ferromagnetic material and has a notched cylindrical shape with a notched upper surface side and upward vertical walls extending from both end edges. And a plate-shaped stator yoke 2 which is provided in a state where both vertical wall portions of the body yoke 1 are connected at the upper end portion thereof, a substantially cylindrical yoke portion is formed, and both end openings of the cylindrical yoke portion are formed. Aluminum caps 9 and 10 made of non-magnetic material are attached to the parts,
At the center of both caps 9 and 10, the bearing 1
1, 12 are press-fitted and fixed. In addition, 8 is a screw for connecting the respective members.

On the inner peripheral side of the cylindrical portion of the body yoke 1, permanent magnets 13 and 14 having two poles magnetized in the radial direction of the cylindrical portion are adhered and fixed. Ferrite magnets are used as the permanent magnets 13 and 14, and the inner peripheral surface is formed in an arc shape centered on the axial center portion of the cylindrical portion of the body yoke 1.
The left permanent magnet 13 so that the inner circumferences have different polarities.
Has an S pole on the inner circumference side and an N pole on the outer circumference side, and the right permanent magnet 14 has an N pole on the inner circumference side and an S pole on the outer circumference side.
Each is magnetized in two poles in the radial direction.

On the inner surface side of the stator yoke 2, a stator 15 made of a ferromagnetic material is fastened and fixed with screws 17. The inner peripheral surface of the stator 15 is formed in an arc shape centering on the axial center portion of the cylindrical portion of the body yoke 1 like the permanent magnets 13 and 14, and the insulating bobbin 18 on the outer peripheral side is formed. Two coils 19 and 20 for generating radial magnetic flux are wound around the stator 15 at the same time.

Next, the drive side member B will be described.
The drive side member B includes a rotor rotating shaft 30 and a pair of rotor yokes 3 adhered and fixed to the outer periphery of the rotor rotating shaft 30.
1 and 32.

The rotor rotating shaft 30 is made of stainless steel (SUS304) which is a non-magnetic material, and both ends thereof are rotatably supported by the bearings 11 and 12.

The rotor yokes 31 and 32 compose the magnetic flux shunting means in the claims, and are formed of a ferromagnetic material in an arc shape. In FIG. 1, between the upper end surfaces in the circumferential direction, A gap a having a magnetically separable width is formed, and a large gap is formed between the lower end surfaces in the circumferential direction. More specifically, the outer peripheral surfaces of the ends of the rotor yokes 31 and 32 on the side of the air gap a face the arc-shaped inner peripheral surfaces of the stator 15 with small gaps b ₁ and b ₂ , respectively, and the rotor yokes 31 and 32 are formed.
The outer peripheral surfaces of the other ends of the _two are small gaps c ₁ and c ₂ respectively.
And facing a part of the arc-shaped inner peripheral surfaces of both permanent magnets 13, 14.

Therefore, in FIG. 1, the left permanent magnet 1
The magnetic flux of 3 flows into the body yoke 1, then passes through the stator yoke 2 and the stator 15, passes through the small gap b ₁ , flows into the left rotor yoke 31, and further passes through the small gap c ₁ to the permanent magnet. A magnetic path D ₁ that returns to 13 is formed, and the magnetic flux of the permanent magnet 14 on the right side is
After passing through the small gap c ₂ and flowing into the rotor yoke 32 on the right side, further passing through the small gap b ₂ and flowing into the stator 15, the magnetic flux is returned to the permanent magnet 14 via the stator yoke 2 and the body yoke 1. The passage D ₂ is formed. Therefore, the flow directions of the magnetic paths D ₁ and D ₂ in the stator 15 portion are opposite to each other.

Next, the coil drive circuit shown in FIG. 3 will be described. One winding start and the other winding end of the coils 19 and 20 are connected to the positive pole of the battery Ba through the terminal 21, and , Coils 19, 20
The other ends of the NPN transistors 24 and 25 are connected to the collector sides of the NPN transistors 24 and 25 through terminals 22 and 23, respectively, and the emitter sides of the NPN transistors 24 and 25 are both grounded. In the figure, 2
Reference numerals 6 and 27 are surge absorbing diodes incorporated in parallel with the coils 19 and 20, respectively.

The duty signal S (D) is input to the base side of the NPN transistor 25 on the coil 20 side, and the duty signal S (D) is input to the base side of the NPN transistor 24 on the coil 19 side via the inverter 28.
(D) is input, the duty signal S (D) is turned on for a period of time Ta so that only the NPN transistor 25 is turned on to allow the current of the battery Ba to flow to the coil 20 side, and the duty signal S (D) is turned off. Tb allows only the NPN transistor 24 to conduct so that the current of the battery Ba flows to the coil 19 side. As described above, the coils 19 and 20 are wired so that the energization directions thereof are opposite to each other, so that the energization of the coils 19 and 20 causes the stator 15 to generate magnetic fluxes φ ₁ , φ ₂ is generated.
As described above, the coils 19 and 20 and the coil drive circuit constitute the coil means in the claims.

Next, the operation of the embodiment will be described. (B) When the coil is de-energized Since there are many leakage circuits in the magnetic circuit and it is difficult to analyze the flow of the magnetic flux accurately, the main flow of the magnetic flux will be explained here. In the state, the magnetic fluxes of the permanent magnets 13 and 14 are in the state of flowing in the _two magnetic paths D ₁ and D _{2 in} which the directions of the magnetic fluxes are opposite to each other in the stator 15 portion as described above.

At this time, from the state shown in FIG.
Rotating in either direction, both rotor yokes 3
The areas of the small gaps b ₁ and b ₂ respectively formed on the facing surfaces between the stators 1 and 32 and the stator 15, that is, the cross-sectional areas of the _two magnetic paths D ₁ and D ₂ are not the same, and thus the cross-sectional areas The magnetic reluctance difference that the magnetic reluctance on the smaller magnetic path side becomes larger than the magnetic reluctance on the smaller magnetic path side, but the magnetic reluctance in both small gap parts b ₁ and b ₂ decreases respectively (the area increases respectively). ) Both rotor yokes 3
The torques for rotating the rotors 1 and 32 act in the directions opposite to each other, so that the torques that are opposed to each other are equally balanced, that is, are formed at the opposed surfaces between the rotor yokes 31 and 32 and the stator 15. Both small gaps b ₁ , b ₂
The return torque for returning the rotor rotation shaft 30 to the neutral stable position (state of FIG. 1) where the areas of the two are the same is always in operation.

Further, in this embodiment, when the rotor rotary shaft 30 is rotated in either direction from the state shown in FIG. 1, it is formed on the facing surface between each rotor yoke 31, 32 and both permanent magnets 13, 14. Area of both small gaps c ₁ and c ₂ ,
Since the cross-sectional areas of the _two magnetic paths D ₁ and D ₂ increase on the one hand and decrease on the other hand, a magnetic resistance difference occurs,
Similar to the above, also in this portion, both small gaps c ₁ , c ₂
The return torque for returning the rotor rotation shaft 30 to the neutral stable position (state of FIG. 1) where the areas of the two are the same is always in operation.

Therefore, when the coils 19 and 20 are not energized, the rotor rotary shaft 30 can be held at the neutral stable position, and the neutral stable position is set to the rotor rotation angle θ = 0 °. When the rotor rotation shaft 30 rotates in either direction from this position, a return torque to the neutral stable position is generated in proportion to the amount of change in the magnetic resistance due to the rotation, and the intensity of this return torque depends on the rotor rotation. It becomes the magnitude of the holding force against the disturbance at the predetermined rotor rotation angle θ of the shaft 30.

FIG. 4 shows a restoring torque T characteristic with respect to the rotor rotation angle θ. As shown in FIG. 4, when the counterclockwise rotation of the rotor rotation shaft 30 is a minus angle and the clockwise rotation is a plus angle, the coil is The return torque T characteristic when the rotor rotary shaft 30 is rotated in the non-energized state is as shown in [I]. Note that the rotor rotation angle θ and the return torque T are in the same direction, that is, when the return torque T is positive, the rotor rotation angle θ is increased, and when the return torque T is negative, the rotor rotation angle θ is decreased. , Therefore R in FIG.
The position of the rotor rotation angle θ = 0 ° shown in ₂ is the rotor rotation shaft 3
The neutral position is 0. Then, the rate of change (gradient) of the return torque T with respect to the rotor rotation angle θ of the rotor rotation shaft 30.
The larger is the magnetic resistance change rate in both magnetic paths D ₁ and D _2, the larger is the holding force against disturbance.

Therefore, by concentrating the magnetic fluxes of the permanent magnets 13 and 14 in the magnetic paths D ₁ and D ₂ , the magnetic energy possessed by the permanent magnets 13 and 14 can be utilized as the return torque T to the maximum efficiency. You will be able to

(B) When the coil is energized Next, when the coils 19 and 20 are energized with the duty signal S (D) as shown in FIG. 3, the duty signal S (D) is supplied.
During the on-time Ta of, the coil 15 is energized only on the side of the coil 20, so that the stator 15 is magnetized by the magnetic flux of the permanent magnet 14 in the direction of φ ₂ (the same direction as the flow direction of the magnetic path D ₁ by the magnetic flux of the permanent magnet 13). A magnetic flux is generated in a direction opposite to the flow direction of the passage D ₂ , and the coil 19 side is energized only during the off time Tb, whereby the stator 15 is magnetized by the direction of φ ₁ (magnetic force of the permanent magnet 14). A magnetic flux is generated in the same direction as the flow direction of the passage D _{2 and in} a direction opposite to the flow direction of the magnetic passage D ₁ by the magnetic flux of the permanent magnet 13. However, in reality, the driving frequency of 1 / (Ta + Tb) is about 100 to 500 Hz, and the time constants of the coils 19 and 20 are sufficiently larger than that.
Off-duty ratio (= Tb × 100 /
(Ta + Tb)%) or on-duty ratio (= T
It can be considered that an average current corresponding to a × 100 / (Ta + Tb)% flows and an average magnetic flux for each average current is generated in the stator 15.

As described above, when the coil 19 is energized, the magnetic flux in the φ ₁ direction generated in the stator 15 weakens the magnetic flux in the magnetic path D ₁ on the permanent magnet 13 side, while the magnetic flux on the permanent magnet 14 side is reduced. The magnetic flux in the passage D ₂ is strengthened,
Further, when the coil 20 is energized, the magnetic flux in the φ ₂ direction generated in the stator 15 weakens the magnetic flux in the magnetic path D ₂ on the permanent magnet 14 side, while the magnetic flux in the magnetic path D ₁ on the permanent magnet 14 side decreases. Be strengthened.

Therefore, when the on-duty ratio is 50% (the off-duty ratio is also 50%) and the strengths of both magnetic fluxes φ ₁ and φ ₂ in the stator 15 which are opposite to each other are uniform, both magnetic paths D ₁ and D ₂ are generated. _Since the balance of both magnetic fluxes in ₂ is also maintained in a uniform state, the rotor rotation shaft 30 is held in the neutral stable position of the rotor rotation angle θ = 0 ° shown by R ₂ in FIG.

Next, when the on-duty ratio is 100% (the off-duty ratio is 0%), the magnetic flux φ generated by the coil 19 is
_{Since 1} is 0% and the magnetic flux φ ₂ due to the coil 20 is 100%, the magnetic flux in the magnetic path D ₁ passing through the stator 16 is strengthened by the retrograde magnetic flux φ ₂ while the magnetic flux on the magnetic path D ₂ side is weakened. As a result, both magnetic paths D ₁ , D ₂
Since the strength of the magnetic flux becomes nonuniform in, in both the small gap b _1, b ₂ parts of an area and both small clearance c _1, both magnetic path D ₁ is the area of the c ₂ parts of the same state, D ₂ Since the balance of the magnetic resistance becomes unbalanced, a positive torque that rotates the rotor rotating shaft 30 in the clockwise direction is generated again. This positive torque causes the rotor rotating shaft 30 to rotate. It is possible to rotate to the position of the rotor rotation angle θ = + 20 ° shown by R ₃ in FIG. 4 and hold it at the rotor rotation angle θ position by the return torque T characteristic shown in [II] of FIG.

Further, when the on-duty ratio is 0% (the off-duty ratio is 100%), contrary to the above, the coil 1
Since the retrograde magnetic flux φ ₁ due to 9 is 100% and the retrograde magnetic flux φ ₂ due to the coil 20 is 0%, a negative torque for rotating the rotor rotating shaft 30 in the counterclockwise direction is generated, and this negative torque causes the rotor to rotate. The rotary shaft 30 is rotated to the position of the rotor rotation angle θ = −20 ° shown by R ₁ in FIG.
Due to the return torque T characteristic shown in [I], it can be held at the rotor rotation angle θ position. This is because the rotor rotation angle θ is -20 ° to + 20 ° by the on-duty ratio control.
It means that it can be controlled at any position within the range.

Although FIG. 5 shows the variable characteristic of the rotor rotation angle θ with respect to the on-duty ratio, a linear variable characteristic can be obtained as shown in this figure. this is,
The direction of the magnetic flux generated in the stator 15 by energizing the coils 19 and 20 is set to the opposite direction, whereby _one of the magnetic fluxes of the two permanent magnets 13 and 14 in each magnetic path D ₁ and D ₂ is strengthened, but Correspondingly, the other one variably controls the rotor rotation angle θ by changing it in the weakening direction, so that magnetic saturation due to insufficient magnetic passage cross-sectional area does not occur in each magnetic passage D ₁ , D ₂ . Is.

As described above, the rotary actuator of the first embodiment has the following effects. The magnetic flux of both permanent magnets 13 and 14 is mainly the permanent magnets 13 and 14, the stator 15, and both rotor yokes 3.
Both permanent magnets 13, 1 have a structure in which there is no other short circuit path that causes magnetic energy loss as in the conventional example, flowing through the respective magnetic paths D ₁ , D ₂ passing through ₁ and 32.
The magnetic energy of 4 can be used efficiently,
Therefore, it becomes possible to increase the holding force for the disturbance torque at the predetermined rotation angle θ position without increasing the power consumption due to the increase of the energizing current and the cost due to the adoption of the expensive permanent magnet.

Since the stator 15 is provided with the two coils 19 and 20 that generate magnetic flux in mutually opposite directions, a wide rotor rotation angle range θ ₀ can be obtained.

Since the energization of the coils 19 and 20 is controlled by the duty signal, the rotor rotation angle θ can be variably controlled by changing the on-duty ratio.

The directions of the two magnetic fluxes generated in the stator 15 when the coils 19 and 20 are energized are made opposite to each other, whereby the magnetic fluxes of the permanent magnets 13 and 14 in the magnetic paths D ₁ and D ₂ are reversed. By variably controlling the rotor rotation angle θ by changing the direction in which one is strengthened and the other is weakened, each magnetic path D ₁ , D _{2 is controlled.}
In this case, magnetic saturation due to insufficient magnetic path cross-sectional area does not occur, and as a result, the variable characteristic of the rotor rotation angle θ becomes linear with respect to the on-duty ratio.

Next, another embodiment of the present invention will be described. In addition, in the other embodiments, the same reference numerals are given to substantially the same components in principle as those of the first embodiment, the description thereof will be omitted, and only the differences will be described.

(Second Embodiment) In the actuator of the second embodiment shown in FIG. 6, the drive direction of the drive side member in the first embodiment is the rotation direction, whereas the drive direction of the drive side member is the rotation direction. It shows an example in which the present invention is applied to a linear actuator having a linear direction.

First, the fixed member A will be described.
In the figure, reference numeral 40 denotes a cylindrical body yoke that constitutes a magnetic path forming means formed of a ferromagnetic material in a cylindrical shape, and has caps 41 and 4 made of a non-magnetic material at openings at both ends thereof.
2 are screwed and fixed. The bushes 43, 44 are provided in the shaft center holes of the both caps 41, 42.
Are press-fitted and fixed.

Regarding the inner diameter of the cylindrical body yoke 40, the axial center portion is formed into a small diameter hole having the smallest diameter, both ends thereof are formed into intermediate diameter holes having a larger diameter, and further, both end sides thereof are the largest. An annular stator 45 is press-fitted and fixed in the small-diameter hole in the central portion, and is formed in an annular shape around bobbins 46 and 47 in both intermediate-diameter holes at both ends thereof. Coils 19 and 20 (see FIG. 3) are press-fitted and fixed, and further, annular permanent magnets 50 and 51 are press-fitted and fixed to both large-diameter holes at both ends.
The coils 19 and 20 are controlled by the coil drive circuit shown in FIG. 3 so as to carry out energization in the same manner as in the first embodiment.

The outer peripheral side of the left permanent magnet 50 is N
While the two poles are magnetized in the radial direction so that the inner circumference side becomes the S pole, the right permanent magnet 51 is magnetized in the radial direction so that the outer circumference side becomes the S pole and the inner circumference side becomes the N pole. It is magnetized.

Next, the drive side member B will be described.
The driving member B is a cylindrical shaft member 5 made of a non-magnetic material.
A pair of left and right annular plunger yokes (magnetic flux shunting means) 53 and 54 made of a ferromagnetic material are attached and fixed to the outer periphery of the magnetic fluxes 2, and the inner facing surfaces of the plunger yokes 53 and 54 are magnetically separable. An annular space a is formed, and annular stopper members 55 and 56 made of a non-magnetic material are press-fitted and fixed to both ends of both plunger yokes 53 and 54.

The plunger yokes 52, 5 are
The outer peripheral surface of the inner end portion of _No. 3 faces the inner peripheral surface of the stator 45 with predetermined small gaps b ₁ and b ₂ , and the outer peripheral surfaces of the outer end portions of both the plunger yokes 52 and 53 are the same. The permanent magnets 50 and 51 face the inner end portions of the inner peripheral surfaces with predetermined small gaps c ₁ and c ₂ , and both ends of the shaft member 52 slide axially with respect to the bushes 43 and 44. Freely supported.

Therefore, after the magnetic flux of the left permanent magnet 50 flows into the body yoke 40, it passes through the stator 45, passes through the small gap b _1, and passes through the left plunger yoke 52.
Into the permanent magnet 5 through the small gap c _1.
A magnetic path D ₁ that returns to 0 is formed, and the magnetic flux of the permanent magnet 51 on the right side passes through the small gap c ₂ and flows into the plunger yoke 54 on the right side, and further, the small gap b ₂
After passing through the magnetic flux D to the stator 45, it returns to the permanent magnet 51 via the body yoke 40.
₂ has been formed. That is, the stator 45
The flow directions of both magnetic passages D ₁ and D _{2 in} the portion are opposite to each other.

Therefore, both the plunger yokes 53, 5 are
4 and the stator 45, the areas of the small gaps b ₁ and b ₂ formed on the opposing surfaces (and the small gap c formed between the permanent magnets 50 and 51 and the plunger yokes 53 and 54).
_The return thrust force for returning the drive side member B to the neutral stable position (state of FIG. 6) where ₁ , ₁ and c ₂ ) are the same is always working.

Therefore, by controlling the duty ratio of the energizing current to both coils 19 and 20 by the duty signal S (D), the magnetic flux φ _{1 in} one direction to the stator 45,
When φ ₂ is generated, the magnetic flux strength increases on the magnetic path side where the magnetic fluxes of both magnetic paths D ₁ and D ₂ are in the same direction with respect to these magnetic fluxes φ ₁ and φ _2, while the magnetic flux On the magnetic path side in the opposite direction, the strength of the magnetic flux decreases and both magnetic paths D
_Since the strengths of both magnetic fluxes at ₁ and D ₂ are not uniform, both small gap portions b ₁ and b ₂ (and small gaps c ₁ and c ₂ )
In the state where the area is the same, the magnetic resistances in both magnetic paths D ₁ and D ₂ are out of balance, so that thrust force for driving the driving member B in the axial direction is generated again until the magnetic resistances are balanced. , The driving side member B by this thrust
Can be driven from the neutral stable position to a predetermined position and held at that position.

That is, in the linear actuator of this embodiment, the same effect as that of the above-mentioned embodiment can be obtained, except that the driving direction is different from that of the above-mentioned embodiment.

The permanent magnet 50 may be divided into a plurality of parts in the circumferential direction, or may be partially provided in a part of the permanent magnet 50 without extending over the entire circumference. In this case, the manufacture is easy. Therefore, the cost can be reduced.

FIG. 7 shows another embodiment of the coil means in the linear actuator of the second embodiment. Two coils 19a, 19b (20a, 20a, 20a, 20a, 20a, 20a, 20b) wound around the bobbins 46 (47) are shown in FIG. 20b) one winding start and the other winding end are connected to the terminal 21a (21b).
b) is connected to the positive pole of the battery Ba, and the other ends of the coils 19a, 19b (20a, 20b) are connected to the NPN via terminals 22 and 23, respectively.
The collectors of the transistors 24 and 25 are respectively connected.

That is, in this other embodiment, each bobbin 4
Two coils 19a and 19 wound around 6 and 47, respectively
b, 20a and 20b are used to generate magnetic flux in opposite directions to the stator 45.

The embodiment has been described above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the present invention is applicable even if there are design changes and the like within the scope not departing from the gist of the present invention. include.

For example, in the embodiment, the small gaps (c ₁ , c ₂ ) formed on the facing surfaces of both permanent magnets and both magnetic flux shunting means.
Although the area of one is increased and the area of the other is decreased at the same time, a structure in which only one area is decreased or a structure in which neither area is changed as shown in FIG. 8 may be adopted. it can.

Further, in the embodiment, two coils for generating magnetic flux in opposite directions are provided as the coil means,
Only one of them may be used. However, in this case, the driving range of the driving member is halved.

Further, in the embodiment, the magnetic flux shunting means are magnetically separated from each other by the air gap (a), but they may be magnetically separated by interposing a non-magnetic member.

[0068]

As described above, in the actuator according to claim 1 of the present invention, as described above, the magnetic fluxes of the two permanent magnets are the two permanent magnets, the two magnetic flux shunting means, the stator and the two magnetic fields. By adopting a structure in which only two magnetic paths constituted by the path forming means flow, and there is no other short circuit path that causes magnetic energy loss as in the conventional example,
The magnetic energy of both permanent magnets can be efficiently used, and therefore, the holding force against external force at a predetermined rotational position can be increased without increasing power consumption and cost. The effect is obtained.

Further, both permanent magnets provided on both sides of the stator are magnetized into two poles in a direction in which the sides facing the magnetic flux shunting means have mutually different polarities, so that the two permanent magnets are formed.
The directions of the magnetic fluxes in one magnetic path are opposite to each other in the stator, and the magnetic flux generated in the stator by the coil means acts to strengthen the magnetic flux on the side of one magnetic path and weaken the magnetic flux on the side of the other magnetic path. As a result, magnetic saturation due to insufficient cross-sectional area of the magnetic path is eliminated, and an effect that linear drive characteristics with respect to the applied current can be obtained is obtained.

Further, in the actuator according to the second aspect, the coil means is configured such that the direction of the magnetic flux generated in the stator can be switched between normal and reverse directions, and the magnetomotive force in each of the forward and reverse magnetic flux directions can be controlled. The effect that the driving range of the member can be widened is obtained.

Further, in the actuator according to the third aspect, the coil means has two coils for generating magnetic flux in opposite directions in the stator, and only one coil is energized at the time of on-duty based on the duty signal. During off-duty, only the other coil is energized and the duty ratio of the duty signal is variably controlled to control the magnetomotive force in each of the forward and reverse magnetic flux directions generated in the stator. The driving position of the side member can be variably controlled.

In the actuator according to the fourth aspect, the driving side member is driven in the rotation direction, and the rotation angle of the rotor can be controlled.

Further, in the actuator according to the fifth aspect, the driving side member is driven in the linear direction, and the linear movement amount can be controlled.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line I-I of FIG. 2 showing a rotary actuator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG. 1 showing the rotary actuator of the first embodiment of the present invention.

FIG. 3 is a diagram showing a coil drive circuit in the rotary actuator of the first embodiment of the present invention.

FIG. 4 is a characteristic diagram of return torque with respect to a rotor rotation angle in the rotary actuator of the first embodiment of the present invention.

FIG. 5 is a variable characteristic diagram of the rotor rotation angle with respect to the on-duty ratio in the rotary actuator of the first embodiment of the present invention.

FIG. 6 is a sectional view showing a linear actuator of a second embodiment of the present invention.

FIG. 7 is a diagram showing another embodiment of the coil drive circuit in the linear actuator of the second embodiment of the present invention.

FIG. 8 is a sectional view showing a modification of the rotary actuator of the first embodiment of the present invention.

[Explanation of symbols]

A fixed member B drive member D ₁ magnetic passage D ₂ magnetic passage b ₁ small gap b ₂ small gap c ₁ small gap c ₂ small gap 1 body yoke (magnetic passage forming means) 2 stator yoke (magnetic passage forming means) 13 permanent magnet 14 permanent magnet 15 stator 19 coil (coil means) 19a coil (coil means) 19b coil (coil means) 20 coil (coil means) 20a coil (coil means) 20b coil (coil means) 31 rotor yoke (magnetic flux shunting means) ) 32 rotor yoke (magnetic flux shunting means) 40 body yoke (magnetic path forming means) 45 stator 50 permanent magnet 51 permanent magnet 53 plunger yoke (magnetic flux shunting means) 54 plunger yoke (magnetic flux shunting means)

Claims (5)

[Claims] 1. A fixed-side member and a driving-side member that can be driven along the fixed-side member, wherein the driving-side member includes a magnetic member that is magnetically separated from each other along the driving direction. A pair of magnetic flux shunting means is provided, and a stator is provided on the surface of the fixed-side member facing each of the magnetic flux shunting means, with one end of each of the magnetic flux shunting means facing each other with a predetermined small gap. Both sides of the stator of the fixed member are two-pole magnetized in a direction substantially orthogonal to the driving direction of the driving member so that the sides facing both magnetic flux diverting means have different polarities. A pair of permanent magnets, each of which has one end portion of the means facing each other with a predetermined small gap, is provided, and the stator generates a magnetic flux in a direction substantially orthogonal to the driving direction of the driving-side member, and generates the magnetic flux. Magnetic force control A coil means capable of forming a magnetic path is formed in the fixed member so as to magnetically communicate between the permanent magnets and the stator on a side opposite to a side of the driving side member facing the magnetic flux shunting means. An actuator comprising means. 2. The coil means is configured so that the direction of the magnetic flux generated in the stator can be switched between normal and reverse directions, and the magnetomotive force in each of the forward and reverse magnetic flux directions can be controlled. Actuator. 3. The coil means has two coils for generating magnetic flux in opposite directions in the stator, and based on the duty signal, only one coil is energized during on-duty and only the other coil during off-duty. 3. The actuator according to claim 2, wherein the magnetomotive force in each of the forward and reverse magnetic flux directions generated in the stator is controllable by energizing the actuator and variably controlling the duty ratio of the duty signal. 4. The fixed side member is formed in an annular shape with both permanent magnets and a stator inside, and the drive side member is composed of a rotatable rotor provided with both magnetic flux shunting means on the outside. The opposing surfaces of the permanent magnets and the stator and the magnetic flux shunting means of the driving side member are formed in an arc shape concentric with the rotation axis of the rotor.
The actuator according to any one of 3 above. 5. The surface of each of the permanent magnets of the fixed member and the stator facing the magnetic flux shunting member of the driving member is formed in a straight line. Actuator described.