JPH08237928A - Actuator - Google Patents

Abstract

PURPOSE: To provide an actuator which can increase its holding power against external force at a specified driving position without increasing the power consumption nor cost. CONSTITUTION: An actuator has such a structure that magnetic flux of a permanent magnet 14 which is installed on a fixed-side member A may flow only in two magnetic paths D1 , D2 , which are formed with the permanent magnet 14, magnetic path forming means (a body yoke 1, connection yokes 5, 6, and stator yokes 3, 4), stators 15, 16, and rotor yokes 31, 32 which are installed on a driven-side member B and thereby there may be no other short-circuit which might cause 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 thereof, and the drive side member is provided on the surface of the fixed side member facing the magnetic flux shunting means. Is provided with a permanent magnet that is magnetized in a direction perpendicular to the driving direction of the magnetic field and has one end of each magnetic flux shunting means facing each other with a predetermined small gap. On both sides, a pair of stators, in which the other ends of the magnetic flux shunting means in the drive side member face each other with a predetermined small gap, are provided, and at least one stator of the pair of stators, Drive Coil means for generating a magnetic flux in a direction orthogonal to the driving direction of the member and controlling the magnetomotive force thereof are provided, and the fixed side member is opposite to the side facing the respective magnetic flux shunting means in the driving side member. On the side, a magnetic path forming means that magnetically communicates between each stator and the permanent magnet is provided.

In the actuator of the second aspect, the coil means is provided on both of the pair of stators.
Further, in the actuator according to claim 3, based on the duty signal, only one coil means is energized during on-duty and only the other coil means is energized during off-duty to variably control the duty ratio of the duty signal. By this, the magnetomotive force generated in both stators is controlled.

In the actuator according to the fourth aspect, the direction of the magnetic flux generated by the coil means is the same as the flow direction of the magnetic path by the magnetic flux of the permanent magnet.
Further, in the actuator according to the fifth aspect, the direction of the magnetic flux generated by the coil means is opposite to the flow direction of the magnetic path due to the magnetic flux of the permanent magnet.

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

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

[0016]

In the actuator according to claim 1 of the present invention,
With the above-described structure, when the coil means is in the non-energized state, the magnetic flux of the permanent magnet passes through the small gaps formed between the surfaces facing the both magnetic flux shunting means and passes through the two magnetic flux shunting means. After the magnetic flux is split and further flows through the small gaps formed between the facing surfaces of the magnetic flux shunting means and the stators to flow into the stators, the magnetic fluxes are passed through the magnetic path forming means (or It is a state in which two shunted magnetic paths are formed to return to the permanent magnet (in the opposite direction).

At this time, if the areas of both small gaps formed on the facing surfaces between the magnetic flux shunting means and the permanent magnet, that is, if the cross-sectional areas of the two magnetic paths are not the same, the magnetic path cross-sectional area is large. A magnetic resistance difference occurs that the magnetic resistance on the side of the smaller magnetic passage is larger than that on the side of the smaller magnetic passage. However, the drive-side member is reduced in the direction of increasing the magnetic resistance in each of the small gaps (increasing the area). The forces (torques or thrusts) that drive the magnets act in directions opposite to each other, so that they are formed at a position where both forces are evenly balanced, that is, at the facing surface between the magnetic flux shunting means and the permanent magnet. The force (return torque or return thrust) for returning the drive-side member to the neutral stable position where the areas of both small gaps are the same is always in a state of acting.

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 is generated in one of the stators by energizing the coil means, the magnetic fluxes in both magnetic paths become non-uniform in strength, so that when the areas of both small gap portions are the same. Since the magnetic resistances in both magnetic paths are out of balance, a driving force is generated to drive the driving member to a position where the magnetic resistances are balanced again, and this driving force moves the driving member from the neutral stable position. It can be driven to a predetermined position and held at that position.

The magnetic flux of the permanent magnet flows only through the magnetic path formed by the permanent magnet, both magnetic flux shunting means, both stators and both magnetic path forming means, and causes magnetic energy loss as in the conventional example. Since there is no short-circuit path, the magnetic energy of the permanent magnet 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.

In the actuator according to the second aspect of the invention, by energizing one of the coil means provided in both of the pair of stators, the driving side member is driven in a predetermined direction from the neutral stable position, and By energizing the other side of the coil means, the drive side member can be driven from the neutral stable position in the opposite direction.

In the actuator according to the third aspect, based on the duty signal, only one coil means is energized during on-duty and only the other coil means is energized during off-duty, and the duty ratio of the duty signal is varied. It is possible to control the magnetomotive force generated in both stators by controlling, that is, the duty ratio is 50%, the drive side member is held in the neutral stable position, and the duty ratio can be increased or decreased from 50%. Thereby, the drive side member can be driven in mutually opposite directions about the neutral stable position.

Further, in the actuator according to the fifth aspect, when the direction of the magnetic flux generated by the coil means is opposite to the flow direction of the magnetic path due to the magnetic flux of the permanent magnet,
Compared to the actuator according to claim 4 in which the magnetic flux of the permanent magnet is in the same direction as the flow direction of the magnetic path, magnetic saturation due to insufficient cross-sectional area of the magnetic path is eliminated, so that a linear drive characteristic with respect to the applied current can be obtained.

Further, in the actuator according to the sixth aspect, the driving side member is driven in the rotational direction, and the rotational angle of the rotor can be controlled. Further, in the actuator according to the seventh aspect, the drive side member is driven in the linear direction, and the linear movement amount can be controlled.

[0025]

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 member A will be described. A pair of upper and lower arc-shaped body yokes 1 and 2 each made of a ferromagnetic material, and a pair of left and right stator yokes 3 and 4, respectively.
A substantially cylindrical yoke portion is formed by the connecting yokes 5, 6, 7, and 8 that connect the end portions of the respective yokes 1, 2, 3, and 4, and the opening portions at both ends of the cylindrical yoke portion are not connected. Aluminum caps 9 and 10 made of magnetic material are attached,
At the center of both caps 9 and 10, the bearing 1
1, 12 are press-fitted and fixed. In addition, 13 is a screw for connecting the respective members.

On the inner peripheral side of the upper arc-shaped body yoke 1, a permanent magnet 14 having two poles magnetized in the radial direction of the cylindrical yoke portion is adhered and fixed. A ferrite magnet is used as the permanent magnet 14, and the inner peripheral surface is formed in an arc shape centered on the axial center portion of the cylindrical yoke portion, and the outer peripheral side has a N pole and the inner peripheral side has a S pole. It is magnetized in two directions.

On the inner surfaces of the left and right stator yokes 3 and 4, stators 15 and 16 made of a ferromagnetic material are fastened and fixed by screws 17 and 18, respectively. The inner peripheral surfaces of both the stators 15 and 16 are formed in an arc shape with the axial center of the cylindrical yoke portion as the center, similarly to the permanent magnet 14, and an insulating coating (not shown) is provided on the outer peripheral side. The coils 19 and 20 for generating magnetic flux in the radial direction are wound around the stators 15 and 16 via the.

Next, the driving 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 rotary shaft 30 is made of stainless steel (SUS304) which is a non-magnetic material, and both ends of the rotor rotary shaft 30 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 surface of the permanent magnet 14 with small gaps b ₁ and b ₂ , respectively, and the rotor yokes 31 and 32 32
The outer peripheral surfaces of the other ends of the _two are small gaps c ₁ and c ₂ respectively.
To face a part of the arcuate inner peripheral surfaces of both stators 15 and 16.

Therefore, in FIG. 1, the magnetic flux of the permanent magnet 14 is split into the left and right in the upper body yoke 1 and then the connecting yokes 5 and 6 and the stator yokes 3 and 4, respectively.
(The above is the magnetic path forming means in the claims), the stators 15 and 16, the small gaps c ₁ and c ₂ , respectively, to flow into the rotor yokes 31 and 32, and further, the small gap b ₁ , B ₂ respectively to pass through the permanent magnet 14
The two divided magnetic paths D ₁ and D ₂ called “return to” are formed.

Next, the coil drive circuit shown in FIG. 3 will be described. One ends of the coils 19 and 20 are connected to the positive pole of the battery Ba through the terminal 21,
The other ends of the coils 19 and 20 are connected to the terminal 2
NPN transistors 24 and 2 via 2 and 23 respectively
5 and the emitter sides of the NPN transistors 24 and 25 are both grounded. In the figure, 26 and 27 are coils 19 and 20, respectively.
On the other hand, it is a surge absorbing diode that is installed in parallel.

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. The coils 19 and 20 are wired so as to generate a magnetic flux in a direction opposite to the flow direction of the magnetic paths D ₁ and D ₂ shunted by the magnetic flux of the permanent magnet.

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 flux of the permanent magnet 14 is in the state of flowing through the _two magnetic paths D ₁ and D ₂ as described above.

At this time, from the state of FIG.
Rotating in either direction, both rotor yokes 3
Areas of the small gaps b ₁ and b ₂ formed on the facing surfaces between the ₁ , 32 and the permanent magnet 14, that is, the two magnetic paths D ₁ and
Since the cross-sectional areas of D ₂ are not the same, a magnetic resistance difference occurs that the magnetic resistance on the side of the smaller magnetic passage is larger than that on the side of the larger magnetic passage, but both small gap portions b ₁ , The torques that rotate the rotor yokes 31 and 32 in the directions in which the magnetic resistance in b ₂ is decreased (the areas are increased respectively) act in the directions opposite to each other, and therefore, the positions where the opposing torques are evenly balanced, That is, the rotor rotary shaft 30 is placed in the neutral stable position (state of FIG. 1) where the areas of the small gaps b ₁ and b ₂ formed on the facing surfaces between the rotor yokes 31 and 32 and the permanent magnet 14 are the same. The return torque to return is always working.

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 each stator 15, 16. Area of both small gaps c ₁ and c ₂ , that is,
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, in the non-energized state of the coils 19 and 20, the rotor rotation shaft 30 can be held at the neutral stable position, and the neutral stable position is 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 the return 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 negative angle and the clockwise rotation is a positive angle, the coil 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 flux of the permanent magnet 14 in both the magnetic paths D ₁ and D ₂ , the magnetic energy possessed by the permanent magnet 14 can be utilized as the return torque T to the maximum efficiency.

(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 20 is energized only on the coil 20 side, and thereby, the magnetic flux in the direction of φ ₂ (direction opposite to the flow direction of the magnetic path D ₂ due to the magnetic flux of the permanent magnet 14) is generated on the stator 16 side, Further, during the off-time Tb, the coil 19 is energized only to generate a magnetic flux in the direction of φ ₁ (direction opposite to the flow direction of the magnetic path D ₁ due to the magnetic flux of the permanent magnet 14) on the stator 15 side. . However, in reality, the drive frequency of 1 / (Ta + Tb) is 100 to 5
At about 00 Hz, the time constants of the coils 19 and 20 are sufficiently larger than that, so
Off duty ratio (= Tb × 100 / (Ta + Tb)
%) Or on-duty ratio (= Ta × 100 /
It can be considered that an average current corresponding to (Ta + Tb)% flows and an average magnetic flux for each average current is generated in the stators 15 and 16.

As described above, by energizing both the coils 19 and 20, the permanent magnet 14 is applied to both the stators 15 and 16.
When a magnetic flux in a direction opposite to the flow direction of the magnetic paths D ₁ and D ₂ shunted by the magnetic flux of is generated, the retrograde magnetic flux weakens the magnetic flux of the magnetic paths D ₁ and D ₂ by the permanent magnet 14. It will be.

Therefore, when the on-duty ratio is 50% (the off-duty ratio is also 50%) and the strengths of both retrograde magnetic fluxes in both stators 15 and 16 are uniform, both magnetic paths D are generated.
_Since the strengths of both magnetic fluxes at ₁ and D ₂ are also maintained in a uniform state, the rotor rotation shaft 30 is in a state in which it is held in the neutral stable position of the rotor rotation angle θ = 0 ° shown by R ₂ in FIG. Become.

Next, when the on-duty ratio is 100% (the off-duty ratio is 0%), the retrograde magnetic flux on the side of the stator 15 around which the coil 19 is wound is 0%, and on the side of the stator 16 around which the coil 20 is wound. Since the retrograde magnetic flux of the magnetic flux is 100%, only the magnetic flux on the magnetic path D ₂ side passing through the stator 16 is weakened by the retrograde magnetic flux, whereby both magnetic paths D ₁ , D
_Since the strength of the magnetic flux in ₂ is non-uniform, both magnetic paths D ₁ and D ₂ are in the state where the area of both small gaps b ₁ and b ₂ and the area of both small gaps c ₁ and c ₂ are the same. In the state where the magnetic resistance in the rotor is 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. Is rotated to the position of the rotor rotation angle θ = + 20 ° shown by R ₃ in FIG. 4, and can be held at the rotor rotation angle θ position by the return torque T characteristic shown in [II] of FIG.

When the on-duty ratio is 0% (the off-duty ratio is 100%), contrary to the above, the coil 1
The retrograde magnetic flux on the side of the stator 15 around which 9 is wound is 100%,
The retrograde magnetic flux on the side of the stator 16 around which the coil 20 is wound is 0%
Therefore, a negative torque for rotating the rotor rotation shaft 30 in the counterclockwise direction is generated, and the negative torque causes the rotor rotation shaft 30 to rotate at the rotor rotation angle θ = −20 shown by R ₁ in FIG.
The rotor can be rotated to the position of .degree. And held at the rotor rotation angle .theta. Position by the return torque T characteristic shown in [III] of FIG. This means that the rotor rotation angle θ can be controlled to an arbitrary position within the range of −20 ° to + 20 ° by the on-duty ratio control.

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 stators 15 and 16 by energizing the coils 19 and 20 is set to the opposite direction, whereby the magnetic flux of the permanent magnets 14 in the magnetic paths D ₁ and D ₂ is varied to weaken the rotor rotation. Since the angle θ is variably controlled, magnetic saturation due to insufficient magnetic path cross-sectional area does not occur in each of the magnetic paths D ₁ and D ₂ .

Further, FIG. 6 shows small gaps b ₁ and b ₂ and
FIG. 6 is an explanatory view showing a ratio of a length in a rotation direction of a gap a by a rotation angle of a rotor rotation shaft 30, and as shown in this figure,
When in the neutral stable position, the angle of the rotor rotation shaft 30 is θ ₀ , and the angle of the arc portion on the inner diameter side of the permanent magnet 14 is θ.
_m , the angle of the void a is θ _s , and the angle of the small gap b ₂ is θ _r (= θ _m / 2-θ _s / 2), the angle θ _s of the void a is 10 ° to 20 °. It is desirable to set the range in order to separate the magnetic flux of the permanent magnet 14 into _two parts, and the difference between the rotation angle θ _r of the small gap b ₂ and the half of the rotation angle range θ ₀ of the rotor rotation shaft 30. (Θ _r −θ _O / 2) is 5 ° to
Setting within a range of 10 ° is desirable in order to obtain linear torque variable characteristics within the rotation angle range θ ₀ of the rotor rotation shaft 30 and linear variable characteristics of the rotor rotation angle θ with respect to the duty ratio.

As described above, the rotary actuator of the first embodiment has the following effects. The magnetic flux of the permanent magnet 14 is mainly
And both stators 15 and 16 and both rotor yokes 31 and 3
Since there is no other short circuit path that causes magnetic energy loss as in the conventional example, it flows through the magnetic paths D ₁ and D ₂ passing through 2 and ₂ , so that the magnetic energy of the permanent magnet 14 can be efficiently Therefore, it is possible to increase the holding force against 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 use of the expensive permanent magnet. Will be able to.

Since the pair of left and right stators 15 and 16 are provided with the coils 19 and 20, respectively, a wide rotor rotation angle range θ ₀ can be obtained.

By setting the directions of the magnetic fluxes generated in the stators 15 and 16 by energizing the coils 19 and 20 in opposite directions, it is possible to eliminate magnetic saturation.
As the variable characteristic of the rotor rotation angle θ, a linear variable characteristic with respect to the on-duty ratio can be obtained.

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 rotary actuator of the second embodiment shown in FIG. 7, the connecting yokes 5, 6, 7, 8 are formed by forming the body yokes 1, 2 in a flat plate shape.
This is a modified example in which is omitted, and substantially the same operational effect as that of the first embodiment can be obtained.

(Third Embodiment) A third embodiment shown in FIGS. 8 and 9.
In the rotary actuator of the embodiment, the ratio of the circumferential lengths of the upper and lower body yokes 1 and 2 is set to the upper body yoke 1.
Shows a modified example in which the stator is changed to be longer, and the positions of both stators 15 and 16 with respect to the permanent magnet 14 are
It shows that there is no need for the 90 ° position as in the example.

Therefore, in addition to the effects substantially the same as those of the first embodiment, the distance between the two stators 15 and 16 with the permanent magnet 14 sandwiched therebetween widens. It is possible to widen the rotation angle range θ ₀ of 30.

(Fourth Embodiment) In the actuator of the fourth embodiment shown in FIG. 10, the drive direction of the drive side member in the first to third embodiments is the rotation direction, whereas the drive side member is It shows an example in which the present invention is applied to a linear actuator whose driving direction is a linear direction.

First, the fixed member A will be described.
In the figure, reference numerals 40 and 41 denote a pair of left and right cylindrical body yokes which are formed of a ferromagnetic material in a cylindrical shape and are formed separately so as to be axially engageable with each other. The inside of the portion is formed in the large-diameter hole 42 to form a thin magnetic passage forming means 43, and the both ends are formed in the small-diameter holes 44, 45 to form thick stators 46, 47. Are configured.

A coil 48 is provided at both ends of the large diameter hole 42.
An annular permanent magnet 50 is attached to the center of the large-diameter hole 42 which is attached with 49 and which is sandwiched between the coils 48 and 49, and whose inner circumference is S pole and the outer circumference is N pole. .

Next, the drive side member B will be described.
A pair of left and right plunger yokes (magnetic flux shunting means) 52 made of a ferromagnetic material are integrally connected and fixed to both ends of the plunger center yoke 51 made of a non-magnetic material, and further outside each of the plunger yokes 52, 53. Plunger side yoke 5 made of non-magnetic material at each end
The columnar movable side member B is configured by integrally connecting and fixing 4, 55.

Then, both the plunger yokes 52, 5
3, the outer peripheral surface of the inner end of the permanent magnet 50 faces the inner peripheral surface of the permanent magnet 50 with predetermined small gaps b ₁ and b ₂ , and the outer peripheral surfaces of the outer ends of the plunger yokes 52 and 53 are Small diameter holes 44, 45 on the inner surface of the stators 46, 47
With respect to the inner end face with a predetermined small clearance c _1, c _2, the plunger side yoke 5 by bushes 56, 57 mounted on the outer end of the small-diameter hole 44, 45
4, 55 are provided so as to be slidably supported in the axial direction.

That is, the magnetic flux of the permanent magnet 50 is split into the left and right in the magnetic path forming means 43, then passes through the left and right stators 46 and 47, respectively, and passes through the small gaps c ₁ and c ₂ , respectively. The two divided magnetic paths D flow into the plunger yokes 52 and 53, pass through the small gaps b ₁ and b ₂ and return to the permanent magnet 50.
₁ and D ₂ are formed.

Therefore, the two plunger yokes 52, 5 are
3 and the area of small gaps b ₁ and b ₂ formed on the facing surface between the permanent magnet 50 (and the small gap c formed between the stators 46 and 47 and the plunger yokes 52 and 53).
Neutral stable position where ₁ and c ₂ ) are the same (state in Fig. 10)
Since the return thrust for returning the drive side member B is always operating, the duty ratio of the energizing current to the coils 48 and 49 is controlled by the duty signal S (D), so that the flux is shunted by the magnetic flux of the permanent magnet 50. By controlling the strength of the magnetic flux that is opposite to the direction of the magnetic flux in the _two magnetic paths D ₁ and D ₂ , the driving-side member B can be linearly driven in the axial direction and held at that driving position. . That is, with 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.

As shown in FIG. 11, the drive side member B includes a shaft member 61 made of a non-magnetic material, a pair of left and right plunger yokes (magnetic flux shunting means) 62 fixed to the outer circumference of the shaft member, It may be configured with 63. Further, the permanent magnet 50 may be divided into a plurality of pieces in the circumferential direction, or may be partially provided in a part of the circumferential magnet without extending over the entire circumference. In this case, FIG.
Since it is easier to manufacture than the structure of the fourth embodiment shown in, the cost can be reduced.

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 the stators and the magnetic flux shunting means.
Although the structure is such that one area increases while the other area decreases at the same time, a structure in which only one area decreases or a structure in which neither area changes can be adopted.

Further, in the embodiment, the coil means is provided on both of the pair of stators, but only one of them may be provided. 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.

Further, the lower body yoke 2 and the lower left and right connecting yokes 7 and 8 in the first to third embodiments may be made of a non-magnetic material.

[0069]

As described above, in the actuator according to the first aspect of the present invention, as described above, the magnetic flux of the permanent magnet is the permanent magnet, both magnetic flux shunting means, both stators, and both magnetic paths. The magnetic energy possessed by the permanent magnets can be used efficiently by adopting a structure in which only the two magnetic paths formed by the forming means flow and there is no other short circuit path that causes magnetic energy loss as in the conventional example. Therefore, it is possible to obtain an effect that it is possible to increase the holding force against the external force at the predetermined rotation position without increasing the power consumption and the cost.

Further, in the actuator according to the second aspect of the present invention, the coil means is provided on both of the pair of stators, so that the driving range of the driving side member can be widened. .

Further, in the actuator according to the third aspect, based on the duty signal, only one coil means is energized at the on-duty and only the other coil means is energized at the off-duty to change the duty ratio of the duty signal. By controlling the magnetomotive force generated in both stators by controlling, the driving position of the driving member can be variably controlled by changing the duty ratio.

Further, in the actuator according to the fifth aspect of the invention, the direction of the magnetic flux generated by the coil means is opposite to the flow direction of the magnetic path due to the magnetic flux of the permanent magnet, whereby the magnetic path due to the magnetic flux of the permanent magnet flows. Compared with the actuator according to claim 4 in which the direction is the same as the direction, magnetic saturation due to insufficient cross-sectional area of the magnetic path is eliminated, so that linear drive characteristics with respect to the applied current can be obtained.

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

In the actuator according to the seventh 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 an explanatory view showing the ratio of the lengths in the rotation direction of the small gap portion and the gap portion in the rotary actuator of the first embodiment of the present invention in angle.

FIG. 7 is a sectional view taken along the line II of FIG. 8 showing a rotary actuator of a second embodiment of the present invention.

FIG. 8 is a sectional view taken along line I-I of FIG. 9 showing a rotary actuator according to a third embodiment of the present invention.

FIG. 9 is a sectional view taken along line II-II in FIG. 8 showing a rotary actuator according to a third embodiment of the present invention.

FIG. 10 is a sectional view showing a linear actuator of a fourth embodiment of the present invention.

FIG. 11 is a diagram showing another example of the driving side member in the linear actuator of the fourth embodiment of the present invention.

[Explanation of symbols]

A fixed side member B drive side 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) 3 stator yoke (magnetic passage forming means) 4 stator yoke (magnetic path forming means) 5 connecting yoke (magnetic path forming means) 6 connecting yoke (magnetic path forming means) 14 permanent magnet 15 stator 16 stator 19 coil (coil means) 20 coil (coil means) 31 rotor yoke (magnetic flux) 32 shunting means) 32 rotor yoke (magnetic flux shunting means) 43 magnetic path forming means 46 stator 47 stator 48 coil 49 coil 50 permanent magnet 52 plunger yoke (magnetic flux shunting means) 53 plunger yoke (magnetic flux shunting means) 62 plunger yoke (magnetic flux shunting means) 63 Plunger yoke (magnetic flux diversion means)

Claims (7)

[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 one surface of each of the magnetic flux shunting means is magnetized in a direction orthogonal to the driving direction of the driving side member on a surface of the fixed side member facing the respective magnetic flux shunting means. Are provided with permanent magnets facing each other with a predetermined small gap, and the other ends of the magnetic flux shunting means of the driving side member are respectively provided on both sides of the permanent magnet of the fixed side member. Is provided with a pair of stators facing each other with a small gap between them, and at least one of the pair of stators generates a magnetic flux in a direction orthogonal to the driving direction of the driving-side member and its magnetomotive force is controlled. And a magnetic path that magnetically communicates between each stator and the permanent magnet on the fixed side member on the side opposite to the side facing each magnetic flux shunting means in the drive side member. An actuator comprising a forming means. 2. The actuator according to claim 1, wherein coil means is provided on both of the pair of stators. 3. Based on the duty signal, only one coil means is energized during on-duty and only the other coil means is energized during off-duty, and the duty ratio of the duty signal is variably controlled to generate in both stators. The actuator according to claim 2, wherein the magnetomotive force to be generated is controlled. 4. The actuator according to claim 1, wherein the direction of the magnetic flux generated by the coil means is the same as the flow direction of the magnetic path by the magnetic flux of the permanent magnet. 5. The actuator according to claim 1, wherein the direction of the magnetic flux generated by the coil means is opposite to the flow direction of the magnetic path due to the magnetic flux of the permanent magnet. 6. The fixed side member is formed in an annular shape with the permanent magnet and both stators inside, and the drive side member is composed of a rotatable rotor provided with both magnetic flux shunting means on the outside. The facing surfaces of the permanent magnet and both stators and both magnetic flux shunting means of the driving side member are formed in an arc shape concentric with the rotation axis of the rotor.
5. The actuator according to any one of 5 above. 7. The permanent magnet of the fixed side member and the opposing surfaces of both stators and both magnetic flux shunting means of the drive side member are formed in a linear shape. Actuator described.