JP3383339B2 - Polarized linear actuator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarized linear actuator which is highly efficient and has a substantially constant suction force over the entire stroke.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Non-polar or polar solenoids that perform linear motion are very often used, but in both cases, the suction force suddenly decreases at a large stroke, in other words, at a large operating gap, and on the contrary, the operating gap is small. However, there was a problem that the suction power suddenly increased. Further, generally, a solenoid having a large stroke consumes a large amount of power. In addition, it is difficult to control the magnitude of the attraction force at the middle part of the path of the movable iron core, and since the attraction direction during energization is fixed, the movement of the movable iron core to other directions will cause a return. It was done by the spring force of the spring. Furthermore, it was relatively difficult to hold and release the movable core at the end after energization.

In view of the above facts, an object of the present invention is to obtain a polarized linear actuator which can generate a substantially uniform suction force in all strokes with low power consumption.

[0004]

In order to achieve the above-mentioned object, a polarized linear actuator according to a first aspect of the present invention has a pair of magnetic bodies each having a hollow portion penetrating therethrough and each generating a magnetic pole. Each of the two in the direction of penetration of the hollow part
A part is inserted into each of the hollow portions so as to have a gap between each of the magnetic members and the suction means disposed opposite to each other, and the movably held linearly. The length in the moving direction is the distance between the outer ends of the pair of magnetic bodies.
The movable iron core, which is shorter and longer than the space between the inner ends, and the permanent magnet, which is provided between the facing magnetic body of the attraction means and passes the first magnetic flux through each of the gaps, and the attraction means. magnetic said permanent in width in the direction along the moving direction is not shorter than the length a length of the movable core of the movable iron core between
A second magnetic flux is provided adjacent to the permanent magnet and passes through the one gap in a direction to be added with the first magnetic flux and passes through the other gap in a direction to be subtracted from the magnetic flux. And an exciting coil.

The invention described in claim 2 is characterized in that, in the polarized linear actuator described in claim 1, a non-magnetic material having a small friction coefficient is disposed in the gap.

According to a third aspect of the present invention, in the polarized linear actuator according to the first or second aspect, a rotating body that rotates with the movement of the movable iron core is provided in the gap.

According to a fourth aspect of the present invention, in the polarized linear actuator according to any one of the first to third aspects, at least one of the hollow portions of the magnetic body is
Whether the gap gradually decreases from the vicinity of the center of the moving direction of the movable core toward the end and becomes the minimum on the end side,
Whether the gap gradually increases from near the center of the moving direction of the movable iron core toward the end and reaches the maximum on the end side,
It is characterized in that it is formed to be either one.

According to a fifth aspect of the present invention, in the polarized linear actuator according to any one of the first to fourth aspects, the front end side or the rear end of the magnetic body in the moving direction of the movable iron core. A holding magnetic pole generating means for mechanically stopping the movement of the movable iron core and magnetically generating a holding magnetic pole for holding the movable iron core is further provided on the part side.

According to a sixth aspect of the present invention, in the polarized linear actuator according to any one of the first to fifth aspects, a front end portion side or a rear end portion of the suction means in the moving direction of the movable iron core is provided. It is characterized in that the magnetic body of the suction means is provided with a protruding portion facing the movable iron core with a small gap so that the movable iron core can be magnetically held on the part side.

[0010]

[Working] polar linear actuator of the present invention according to claim 1, who each magnetic pair for generating a and each pole through the hollow portion penetrates the hollow portion
The suction means are arranged so as to face each other at opposite ends . A part of the movable iron core, which is linearly movably held, is inserted into each of the hollow portions provided in the pair of magnetic bodies of the suction means so as to have a gap between each of the magnetic bodies. There is. This movable iron core has a length in the moving direction shorter than the distance between the pair of magnetic bodies , that is, the distance between the outer end portions, and
Rather it is configured length than the distance between the inner end portion. By making the gap (hereinafter referred to as a gap) between the magnetic pole and the movable iron core in each magnetic body of the suction means substantially uniform, the polarized linear actuator can exert a uniform suction force. Further, if the movable iron core is formed to have substantially the same cross section with respect to the attraction direction and the end faces of the attraction magnetic poles and the peripheral face of the movable iron core are arranged at equal intervals, when the movable iron core is drawn into the attraction means, the gap is formed over the entire stroke. Becomes almost uniform, and a uniform suction force can be exhibited. A magnetic flux from a permanent magnet is passed through the gap, and a magnetic flux from the exciting coil is superposed on the magnetic flux. Excitation coil is next to the permanent magnet width in the direction along the moving direction of the movable iron core is at not shorter than the length length of the movable core
It is provided to fit . This polarized linear actuator constitutes a magnetic circuit by the magnetic fluxes of the permanent magnet and the exciting coil. In the gap in one magnetic body of the attracting means, the first magnetic flux of the permanent magnet and the second magnetic flux of the exciting coil are formed. The magnetic circuit is configured such that the first magnetic flux of the permanent magnet and the second magnetic flux of the exciting coil are subtracted from each other in the gap of the other magnetic body so that and are added. In this magnetic circuit, the permanent magnet is not included in the magnetic path through which the magnetic flux of the exciting coil passes. As a result, the permeance of the circuit of the exciting coil can be reduced, the magnetic flux generated by the exciting coil can be increased with a small amount of electric power, and a large attractive force can be obtained with a small amount of electric power.
Also, the gap between the magnetic members facing the suction means, that is, the outer end
Since the length has a movable iron core from short and spacing of the inner end portion than the distance between the parts is inserted into the hollow portion, the magnetic flux by the magnetic circuit formed is reliably provided to the movable iron core, between the confronting magnetic body suction means permanent magnets, and the width acting on the magnetic flux by the magnetic flux and the exciting coil by the permanent magnet because the excitation coil is provided so as to be adjacent to the permanent magnet with a length shorter than the length reliably movable core of the movable iron core.

When the magnetic flux passes at a right angle to the boundary surface (the surface along the gap direction) between the magnetic pole and the movable iron core, the force (attracting force F) that the movable iron core is drawn in the direction perpendicular to the magnetic flux. , As shown in the following equation (1), the gap δ, the circumference b of the movable iron core (where the diameter is d, b = π ·
d) and the magnetic flux density B.

F ∝ (B ² · δ · b) / (2 · μ) --- (1) If the excitation of the magnetic body of the attracting means is performed only by the exciting coil, the rating of the polarized actuator is Once determined, the magnetic flux density B is determined in proportion to the excitation ampere-turn. That is, the magnetic flux density B is proportional to the square of the exciting power. For example,
If the magnetic flux density obtained with the excitation power of 1 W is 0.5 Tesla, 9 W is required to obtain 1.5 Tesla. Here, when the magnetic flux from the exciting coil is superposed on the gap through which the magnetic flux from the permanent magnet passes, assuming that the magnetic flux density from the permanent magnet is B ₀ and the magnetic flux density from the exciting coil is B ₁ , the attractive force is (B ₀ ± B ₁ ) Determined by ² . That is, by setting the magnetic flux density B ₀ of the permanent magnet, the power of the exciting coil can be saved by B ₀ . For example, assuming that the magnetic flux density B ₀ is 1 Tesla, the electric power that can generate a magnetic flux of 0.5 Tesla,
That is, a magnetic flux of 1.5 Tesla can be obtained with 1 W of electric power. That is, it is possible to obtain a suction force of 9 W with a power of 1 W. At this time, the suction force F of 1 tesla remains even when there is no power, but this solution will be described later.

Therefore, the circuit of the magnetic flux of the permanent magnet and the circuit of the magnetic flux of the exciting coil overlap each other at the gap and do not overlap each other, so that the permanent magnet having a high magnetic resistance does not enter the circuit of the exciting coil. With this configuration, the magnetic flux generated by the exciting coil efficiently passes through the gap and is polarized to obtain a large attractive force with less electric power.

According to the present invention, a pair of magnetic bodies each having a hollow portion are opposed to each other, and the difference in the attraction force between the hollow portions of the magnetic bodies serves as an operating force to the outside. Since the magnetic flux density of the permanent magnets of both magnetic materials is basically the same anywhere in the stroke, the attraction force of the permanent magnets is balanced by both magnetic materials, and the attraction force is generated outside. do not do. That is, the movable iron core receives no force anywhere in the entire stroke.

The magnetic flux generated by the exciting coil is added to the magnetic flux of the permanent magnet in one magnetic body and subtracted in the other magnetic body. Therefore, the magnetic flux density of the exciting coil in the magnetic body on one side (for example, the right side) is increased. the magnetic flux density B _1, when the magnetic flux density generated by the excitation coil in the magnetic on the other side (e.g., left side) and the magnetic flux density B _2, the suction force F when the excitation coil is activated, the following equation (2) Can be represented.

F∝ (B ₀ + B ₁ ) ² − (B ₀ −B ₂ ) ² (2) This equation (1) is converted into the following equation (2).

F∝2 · B ₀ · (B ₁ + B ₂ ) + (B ₁ ² −B ₂ ² ) ... (3)

At this time, B ₀ >> B ₁ , B _{0 for} each magnetic flux density
>> When there is a relation of B ₂ , that is, when the magnetic flux density by the exciting coil is sufficiently smaller than the magnetic flux density of the permanent magnet, the second term of the equation (2) is ignored and the attractive force is determined by the first term.
In this case, a much larger attraction force can be obtained than with the exciting coil alone. Further, the attractive force in this case is linearly proportional to the magnetic flux of the exciting coil. And the suction force is almost the same over the entire stroke. When the magnetic flux of the exciting coil is large, the second term of equation (2) cannot be ignored, so the attraction force changes with stroke and is usually strong at the beginning of pulling and weak at the end of pulling. There is no big change. Further, to cope with this, the change can be further reduced by considering the shape of the magnetic body so that the gap between the iron core and the magnetic pole of the magnetic body changes as the iron core moves. When B ₀ is increased, a larger force can be exerted than the conventional solenoid with the same electric power.

Conventionally, there is a magnetic speaker or the like in which B ₀ >> B ₁ is obtained with high efficiency by using this principle. The present invention utilizes this principle to form a polarized actuator having a linear motion with the above structure, and obtains a substantially uniform suction force and high efficiency over the entire stroke.

In the above-mentioned polarized actuator, the force that causes the attracting means and the movable iron core to be eccentric by the generation of magnetic flux is
As described in claim 2, this can be solved by inserting a non-magnetic material having a small friction coefficient and having a thickness substantially equal to the gap between the magnetic pole and the movable iron core in each magnetic material. Further, as described in claim 3, a rotating body that rotates with the movement of the movable core may be further provided in this gap.

Here, when the second magnetic flux of the exciting coil becomes larger than the first magnetic flux of the permanent magnet, it becomes difficult to obtain a constant attractive force under a constant gap and becomes weak at the end. . This is because the suction force can be made substantially uniform by changing the gap according to the movement of the movable iron core.

That is, as described in claim 4, in at least one of the magnetic bodies facing the suction means, the gap gradually decreases from the vicinity of the center in the moving direction of the movable iron core toward the end portion, and the end portion. It is formed so that it becomes the minimum on the side.
Therefore, at least one of the magnetic bodies has a wedge shape in which the gap gradually decreases from the center of the suction means toward the end. In this way, the gap is large at the initial stage of suction and becomes small at the final stage, so that the suction force is corrected to be constant. Further, by doing so, the magnetic flux density due to the permanent magnet in the minimum portion where the gap is reduced increases when there is no energization, and this portion (end portion)
The movable iron core can be stopped with. On the contrary, at least one of the magnetic bodies facing the suction means is
By forming the gap so that it gradually increases from near the center of the moving direction of the movable core toward the end and reaches the maximum on the side of the end, the movable core can be stably placed near the center of the stroke when no power is supplied. Can be stopped. That is, by forming each magnetic body so that the gap gradually decreases toward the center of the suction means, the gap is minimized at the central portion of the suction means, the magnetic flux density is increased, and the movable iron core is stopped at the center. be able to.

Further, in order to maintain the movable iron core at the position of one end thereof, as described in claim 5, the magnetic core is provided on the front end side or the rear end side in the moving direction of the movable iron core. A holding magnetic pole generating means may be further provided for mechanically stopping the movement of the movable iron core and magnetically generating a holding magnetic pole for holding the movable iron core. As a result, the holding magnetic pole generator can stop the movement of the movable core while the magnetic flux passes to generate the magnetic pole, and the movable core can be maintained at the position of the attracted end. As another means for holding the movable iron core at the end, as described in claim 6, the movable iron core is magnetically held at the front end side or the rear end side in the moving direction of the movable iron core of the suction means. The magnetic body of the suction means may be provided with a protruding portion that faces the movable iron core with a small gap so as to be possible. By doing so, the gap at the end on the suction side becomes narrower than the gaps at other locations. As a result, when the magnetic flux concentrates on a portion having a narrow gap and the movable iron core moves, the movable iron core can be stopped at the end of the movable iron core on which the magnetic flux is concentrated.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings.

A polarized linear actuator Ac which is a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
Polarized linear actuator Ac of the present embodiment includes a plate-shaped external yoke 8 _U, 8 _D vertically, the external yoke 8 _U
In the lower part of the inner surface of the plate, a plate-shaped permanent magnet 1 magnetized in the thickness direction
_U is attached, and a plate-like permanent magnet 1 _D magnetized in the thickness direction is attached to the upper portion of the inner surface of the outer yoke 8 _D. A yoke 5 for passing magnetic flux is attached to the permanent magnets 1 _U and 1 _D. In addition, on the left and right side surfaces of the yoke 5,
Permanent magnets 1 _R and 1 _L are attached to increase the magnetic flux passing through the yoke. Therefore, magnetic poles are generated on the inner surface of the hollow portion of the yoke 5.

Further, at both ends of the outer yokes 8 _U and 8 _D ,
Magnetic bodies 9 _R and 9 _L having low magnetic resistance are attached. The magnetic bodies 9 _R and 9 _L are formed in a plate shape having a through hole near the center. The inner surfaces of the through holes of the magnetic bodies 9 _R and 9 _L become magnetic poles 18 _R and 18 _{L due} to the magnetic flux passing through the magnetic bodies.

Bearings 7 _R and 7 _L are attached to the outsides of the magnetic bodies 9 _R and 9 _L , respectively.
_The support rod 6 is passed through _R and 7 _L. A cylindrical movable iron core 3 is attached to the support rod 6, and the movable iron core 3 can be moved to the left and right (the arrow A direction and the counter arrow A direction in FIG. 1A). The movable iron core 3 may have a plate shape or a round bar shape.

In the space between the magnetic body 9 _R and the permanent magnets 1 _U and 1 _D and in the direction along the peripheral surface of the movable core 3, the exciting coils 4 _R are wound. Therefore, the direction of the magnetic flux generated by the coil 4 _R is the same as the moving direction of the movable iron core 3. Similarly, in the space between the magnetic body 9 _L and the permanent magnets 1 _U and 1 _D and in the direction along the circumferential surface of the movable iron core 3, the excitation coils 4 _L are wound and movable by the coils 4 _L. A magnetic flux in the same direction as the movement of the iron core 3 is generated. These are external yokes 8 _U and 8 _D and magnetic material 9 _R ,
9 _L constitutes the suction means.

Next, the operation of the polarized linear actuator Ac of this embodiment will be described with reference to the magnetic flux passing inside. The magnetic flux generated by the permanent magnets 1 _U and 1 _D has a solid arrow 1
2 (see FIG. 1A). That is, the magnetic fluxes flowing into the left and right magnetic poles 18 _R and 18 _L are in the same direction. In this case, the outer circumference of the movable iron core 3 becomes an N pole, and the magnetic poles 18 _R , 1 generated on the inner surfaces of the hollow portions of the magnetic bodies 9 _R , 9 _L.
8 _L becomes the south pole.

The magnetic flux generated by exciting the left and right coils 4 _R and 4 _L in the same direction is directed in the direction of the dotted arrow 14. At this time, the magnetic flux of the permanent magnet and the magnetic flux generated by the coil are generated by the outer peripheral surface of the movable iron core 3 and the magnetic poles 18 _R , 1 which are the inner surfaces of the hollow portions of the magnetic bodies 9 _R , 9 _L.
It passes through the gaps 16 _R and 16 _L between 8 _L , but is radiated together from the movable core 3 to the magnetic body 9 _{L in} the left gap 16 _L (see FIG. 3 (1)), and the two magnetic fluxes are added. is, concentrated flux magnetic flux generated by the right permanent magnets in the gap 16 _R of is generated by the emitted and the coil toward the movable iron core 3 to the magnetic 9 _R is toward the magnetic body 9 _R to the movable iron core 3 As a result (see FIG. 3B), the two magnetic fluxes flow in the direction in which they are subtracted.

Therefore, in the left and right gaps between the movable iron core 3 and the magnetic bodies 9 _R and 9 _L , the magnetic flux density of the left gap 16 _L becomes larger than the magnetic flux density of the right gap 16 _R , and the movable iron core 3 becomes It is sucked in the left direction (direction opposite to arrow A in FIG. 1A).

When the direction of the coil current is made to flow in the opposite direction to the above case, the magnetic flux density in the gap is reversed right and left and the movable iron core moves to the right (the direction of arrow A in FIG. 1 (a)). As described in the section of action, the force received by the movable iron core 3 is a function of the magnetic flux density B by the permanent magnet, the magnetic flux by the magnetomotive force by the coil (electromagnet), and the width in the direction perpendicular to the moving direction of the movable iron core 3. become.

Here, the magnetic flux from the coil does not pass through the permanent magnets 1 _U and 1 _D having a large magnetic resistance, but the magnetic bodies 9 _R and 9 _{L having} a small magnetic resistance, the outer yokes 8 _U and 8 _D, and the movable iron core. Three
Since it passes through, the magnetic circuit can be easily formed, and a desired magnetic flux can be obtained with less electric power.

Next, a second embodiment will be described with reference to FIG. The polarized linear actuator Ac of the present embodiment is an example in which each member has a cylindrical shape. Since the present embodiment has substantially the same configuration as the above-mentioned embodiment, the same reference numerals are given to the same portions, and detailed description thereof will be omitted.

The outer yoke 8 of this embodiment has a cylindrical shape, and a cylindrical permanent magnet 1 magnetized in the radial direction is attached to the inner surface of the outer yoke 8. Inside the permanent magnet 1, a yoke 5 that allows magnetic flux to pass is attached. Therefore, as in the above embodiment, magnetic poles are generated on the inner surface of the hollow portion of the yoke 5.

At both ends of the outer yoke 8, cylindrical magnetic bodies 9 _R and 9 _L having a small magnetic resistance are attached. The inner surfaces of the magnetic bodies 9 _R and 9 _L become magnetic poles 18 _R and 18 _{L due} to the magnetic flux passing through the magnetic bodies.

In the space between the magnetic body 9 _R and the permanent magnet 1 and in the direction along the peripheral surface of the movable iron core 3, the exciting coil 4 is provided.
Each _R is wrapped around. Therefore, the direction of the magnetic flux generated by the coil 4 _R is the moving direction of the movable iron core 3 according to the direction of the flowing current (the direction of arrow A in FIG.
Direction). Similarly, in the space between the magnetic body 9 _L and the permanent magnet 1 and in the direction along the peripheral surface of the movable iron core 3, the exciting coils 4 _L are wound respectively.
A magnetic flux in the same direction as the movement of the movable iron core 3 is generated by _L.

As described above, in the present embodiment, by forming each member into a cylindrical shape, the shape of the parts can be simplified, and the cost and the size can be further reduced. The description of the operation of the present embodiment is the same as that of the above-mentioned embodiment, and will be omitted.

Next, a third embodiment will be described with reference to FIG. In this embodiment, the coil on the right side of the above embodiment is omitted. Since the third embodiment has substantially the same configuration as the above-mentioned embodiments, the same parts are designated by the same reference numerals and detailed description thereof will be omitted.

The first permanent magnet to the inner surface lower portion of the outer yoke 8 _U is _U
Is attached, and the permanent magnet 1 _D is attached to the upper portion of the inner surface of the outer yoke 8 _D. A yoke 5 for passing magnetic flux is attached to the permanent magnets 1 _U and 1 _D. Magnetic bodies 9 _R and 9 _L are attached to both ends of the outer yokes 8 _U and 8 _D. In the space between the magnetic body 9 _R and the permanent magnets 1 _U and 1 _D and in the direction along the peripheral surface of the movable iron core 3, the exciting coils 41 are wound. Therefore, the direction of the magnetic flux generated by the coil 41 is
It becomes the same direction as the moving direction of.

Next, the operation of this embodiment will be described. The magnetic flux generated by the permanent magnets flows in the same direction as the solid arrow 12 as in the above embodiment (see FIG. 5A). In addition, the magnetic flux generated by being excited by passing a current in a predetermined direction through the coil 41 is in the direction of the dotted arrow 14. At this time, the magnetic flux of the permanent magnet and the magnetic flux of the coil pass through the left and right gaps 16 _R and 16 _L , but the left gap 16 _L
Then these two magnetic fluxes are added and the right gap 16 _R
Then, it flows in the direction of subtraction. Therefore, the magnetic flux density of the left gap 16 _L becomes larger than the magnetic flux density of the right gap 16 _R , and the movable iron core 3 moves to the left (see the arrow A in FIG. 5A).
Direction). When a current is applied to the coil 41 in the opposite direction to the above, the magnetic flux density in the gap is reversed right and left, and the movable iron core moves to the right (the direction of arrow A in FIG. 5A).

As described above, the magnetic flux generated by the coil 41 forms a magnetic circuit through the movable iron core 3 without passing through the permanent magnet having a large magnetic resistance. In this embodiment, the efficiency deteriorates due to the decrease in the number of coils, but the shape of the polarized actuator can be made smaller than that in the above embodiments.

Next, a fourth embodiment will be described with reference to FIG. The polarized linear actuator Ac of the present embodiment shows a simple configuration example for smoothly moving the movable iron core. Since the present embodiment has substantially the same configuration as the above embodiment, only the main parts are shown, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

In this embodiment, the inner surface of the magnetic body and the movable iron core 3 are
A bearing 51 is provided in the gap between the outer peripheral surface of the bearing. The movable iron core 3 is always attracted by the left and right magnetic bodies 9 _R and 9 _L , and when the movable iron core 3 is a plate-shaped member, it rotates clockwise (counterclockwise) or in a counterclockwise direction (arrow A in FIG. 6A, FIG.
(B) Refer to the direction of arrow B) and receive the force of being attracted to the magnetic body. Further, when the movable iron core 3 is in the shape of a round bar, it does not receive the rotational force (see the arrow C direction in FIG. 6C), but in the longitudinal direction of the movable iron core 3, the rotational force (arrow A in FIG. Direction).

As described above, when the movable iron core 3 is attracted to the magnetic bodies 9 _R and 9 _L , the movable iron core 3 cannot be moved due to friction at the end faces of the magnetic bodies, so that the movable iron core 3 is supported in the above embodiment. The support bar 6 is passed through the bearing 7 to allow the movable iron core to move. In the present embodiment, instead of the support rod 6 and the bearing 7, the thickness of the gap is approximately equal to the gap,
A bearing 51 made of a material having wear resistance and a low coefficient of friction is attached. Thus, the same effect as that of the above-described embodiment can be obtained by disposing the bearing 51 only on the moving portion of the movable iron core 3 without providing the bearing 7 for moving the movable iron core 3 outside. The support by the bearing 51 is simpler in manufacturing and assembling than the support by the bearing of the above-mentioned embodiment.

As another example of the bearing 51, FIG.
As shown in, a bearing 61 for rotating the movable iron core 3 with a small movement resistance while rotating by itself and appropriately maintaining the left and right gaps between the magnetic body and the movable iron core 3 may be provided. . The bearing 61 is arranged, for example, in a groove formed on the magnetic body or the movable iron core 3 or both so as to maintain an appropriate gap. The bearing 61 is composed of a rotating body such as a ball, a round bar, a ball bearing, or a thrust bearing. Although the structure using this rotating body is slightly more complicated than the above structure, it is possible to reduce the friction loss between the bearing and the movable iron core, and to reduce the movement resistance of the movable iron core. Therefore, the polarized linear actuator Ac can be moved with less electric power.

Next, a fifth embodiment will be described with reference to FIGS. Polarized linear actuator Ac of the present embodiment
Indicates that the gap is changed along the direction in which the movable iron core 3 moves. Since the fifth embodiment has substantially the same configuration as the above-mentioned embodiments, only the main parts are shown, the same parts are designated by the same reference numerals, and detailed description thereof will be omitted.

When it is desired to stop the movable iron core 3 at the end of the polarized linear actuator Ac, the magnetic body is formed so that the gap gradually increases from one end to the other end, as shown in FIG. To do. That is, the magnetic materials 9 _R , 9
_A truncated cone-shaped through hole is formed in _{L so} that the end surface on the movable iron core side is inclined with respect to the movable iron core 3. In addition, magnetic substances 9 _R , 9
_L is arranged to the left and right ends of the external iron core 8 _U (FIG. 7 antiferromagnetic arrow A direction of the distal end portion, and FIG arrow A direction of the distal end portion) of the gap at a minimum. As a result, when power is off,
The attraction force at the left and right ends of the magnetic bodies 9 _R and 9 _L becomes maximum, and the unstable balance point becomes near the middle of the moving direction of the external yoke. Therefore, the movable iron core 3 is stable and stationary at either one of the left and right end portions, and does not stand still at the middle portion.

In the above description, the case where the gap is changed by making the end face of the magnetic pole an inclined face has been described, but the end face of this magnetic body may be an inclined face which changes linearly.
Further, it may be a curved inclined surface that continuously changes according to the suction force characteristic formed by the gap.

Here, as described in the above operation,
When the magnetic flux due to the coil becomes substantially the same as the magnetic flux due to the permanent magnet, when the movable core 3 moves from one end of the magnetic body to the other end by the excitation of the coil, when the gap is constant, The force of pulling is strong and the force of pulling is weak. In this embodiment, the gap changes as the movable iron core 3 moves. Therefore, with the above configuration, the difference between the pulling start force and the pulling end force can be changed, and this difference can be set freely by selectively determining the amount of change in this gap. it can. That is,
If the difference between the pulling start force and pulling end force of the movable iron core is determined, the rate of changing the gap can be determined.

As described above, according to this embodiment, since the difference between the pulling start force and the pulling end force can be changed, it is possible to obtain a polarized linear actuator that holds the suction force according to the stroke. You can

Next, a case where the movable iron core is made to be stable and stationary near the center when no power is supplied will be described with reference to FIG. The magnetic bodies 9 _R and 9 _L are arranged symmetrically via an external yoke so that the gaps between the left and right ends and the inner end are compared to minimize the inner end. This maximizes the attraction force at the central ends of the magnetic bodies 9 _R and 9 _{L when} the power is off.
External yoke 5 _U, 5 balance in near the middle and _D, will be stationary. Therefore, the movable iron core 3 stably stands still at the midpoint of the moving stroke when there is no energization, and is excited in either the left or right direction (direction of arrow A or counter arrow A in FIG. 9) by the excitation depending on the direction of the current supplied to the coil. Moving. In this way, the movable iron core can be stopped at the intermediate point of the polarized linear actuator, so that a polarized linear actuator that can move in both directions can be obtained.

Next, a sixth embodiment will be described with reference to FIG. The present embodiment is intended to hold the movable iron core 3 that has finished operating at that position without electricity.
Since the present embodiment has substantially the same configuration as the above-mentioned embodiment, the same reference numerals are given to the same portions, and detailed description thereof will be omitted.

A holding magnetic body 91 is provided at the left end of the magnetic body 9 _L so that a part of the end of the movable iron core 3 is in contact with the magnetic body 9 _L. Therefore, when the movable core 3 moves and reaches the left end, the magnetic flux of the permanent magnet mainly flows as shown by the solid line 95. That is, since the gap between the holding magnetic body 91 and the movable iron core 3 is made smaller than the gap between the magnetic body and the movable iron core 3, the permeance of this gap is large and a large holding force is exerted. Movable iron core 3
Can be held. The holding magnetic body 91 also serves as a stopper for the movable iron core 3.

In this embodiment, the movable iron core 3 that has finished operating
Can be held at that position without power supply, but this holding is released by a coil that applies an excitation opposite to that when this operation is performed. However, even at this time, since the permeance of the magnetic circuit is large, the holding of the movable iron core 3 can be released with a small amount of electric power.

Next, a seventh embodiment will be described with reference to FIG. The present embodiment shows another example of holding the movable iron core 3 at a position where the movable iron core 3 has finished operating in the above-described embodiment with no power supply, without being energized.

A protrusion 101 is formed on the magnetic body 9 _L of the present embodiment, and the gap at the tip of the protrusion 101 with respect to the movable core 3 is narrower than the portion other than the protrusion 101. Therefore, in this embodiment, the movable iron core 3
The gap rapidly narrows at the position where the magnet has been pulled to the end on the left side and has finished moving, and the magnetic flux flowing between the magnetic body 9 _L and the movable iron core 3 is concentrated in this narrow portion and the magnetic flux flows in this portion. Since the density increases, the suction force at this portion increases and holds the end of the movable iron core 3. That is, the portion of the magnetic material having the narrow gap has a function as a holding magnetic pole. As described above, in the present embodiment, since the movable core 3 can be held at a predetermined position without the movable core 3 colliding with other members, no collision noise is generated and the operation is quiet.
A polarized linear actuator having a long life can be provided.

Next, an eighth embodiment will be described with reference to FIG. The present embodiment shows a configuration for returning the movable core without using a spring force such as a spring. Since the present embodiment has substantially the same configuration as the above-mentioned embodiment, the same reference numerals are given to the same portions, and detailed description thereof will be omitted.

In this embodiment, the left and right magnetic bodies 9 _R and 9 _L have different shapes. That is, the magnetic body 9 _L is formed so that the end surface changes so that the gap is minimized at the left end of the figure, and the magnetic body 9 _R has an inner surface of the hollow portion with respect to the movable iron core 3. It is formed to be parallel and attached to the external yoke. That is, the gap 111 between the magnetic pole 18 _L and the movable iron core 3 generated in the magnetic body 9 _L and the gap 112 between the magnetic pole 18 _R and the movable iron core 3 generated in the magnetic body 9 _R are The gap 111 on the left side is the same width, and the gap 11 on the right side is at the end near the center.
It has the same width as 2, and the gap becomes narrower toward the left end. Thus, the gaps 111 and 112 in the left and right magnetic bodies do not match. As described above, since the gap 111 is gradually narrowed, the suction force of the gap 111 is larger than that of the gap 112, so that the movable core 3 stops at the left end portion.

[0060] In order to move the movable iron core 3 to the right, when energized exciting current to the coil, the magnetic flux and the coil of the permanent magnet flux, the magnetic body 9 _L pole 18 _L and the movable iron core 3 of the left In the interval, the two magnetic fluxes of the permanent magnet and the coil are subtracted, and the magnetic flux flows in the addition direction between the magnetic pole 18 _R of the magnetic body 9 _{R on} the right side and the movable iron core 3. As a result, the magnetic flux density of the right gap 112 becomes higher than the magnetic flux density of the left gap 111, and the movable iron core 3 moves in the right direction (arrow A in FIG. 12).
Direction). When the supply of the exciting current to the coil is cut off, the relationship between the addition and subtraction of the magnetic flux on the left and right of the magnetic body is broken, the magnetic flux density of the left gap 111 increases, and the movable iron core 3 stops at the left end.

Therefore, the attraction force of the permanent magnet is always strong on the left side (the portion with respect to the gap 111) and weaker on the right side (the portion with respect to the gap 112) when there is no energization. The movable iron core 3 is attracted to the right by the excitation of the coil. When this excitation is stopped, the movable core returns to the left again. As described above, in this embodiment, since the movable iron core 3 can be moved to the right and returned to the left and then stopped, the movable iron core 3 can be moved to one end of the polarized actuator without using a spring force such as a spring. The iron core 3 can be returned and made to stand still.

[0062]

As described above, according to the present invention, the magnetic flux is set and generated so as to intersect with the moving direction of the movable iron core, and the magnetic flux is generated in the adding direction and the subtracting direction of the magnetic flux. Therefore, it is possible to obtain an efficient polarized linear actuator that can obtain a large suction force with a small amount of electric power, and obtain a large suction force even with a large stroke.

Further, by changing the gap between the magnetic body and the movable iron core, it is possible to change the attraction force characteristic showing the relationship between the stroke and the attraction force according to the application and the direction of the magnetic flux generated in the coil. The effect that the movable iron core can be moved in both directions by changing is obtained.

[Brief description of drawings]

1 shows a schematic structure of a polarized linear actuator of a first embodiment, (a) is a sectional view taken along the axial direction of the movable core of FIG. 2, and (b) is a movable core of FIG. It is sectional drawing cut | disconnected along the direction orthogonal to the axial direction of.

FIG. 2 is an external view including a partial cross section of the polarized linear actuator of the first embodiment.

FIG. 3 is an image diagram corresponding to the I-I line cross section and the II-II line cross section of FIG. 1A, for explaining the magnetic flux flowing in and out of the magnetic body of the first embodiment.

FIG. 4A shows a polarized linear actuator of a second embodiment, FIG. 4A is a view corresponding to FIG. 1A, and FIG.
[Fig. 4] is a sectional view taken along line I-I of Fig. 4 (a).

FIG. 5 shows a polarized linear actuator of a third embodiment, (a) is a diagram corresponding to FIG. 1 (a), and (b) is a diagram.
FIG. 3 is a diagram corresponding to FIG.

FIG. 6 is a diagram showing a main part of a polarized linear actuator of a fourth embodiment, (a) is a front view, (b) is a side view of a plate-shaped movable iron core, and (c) is a cylindrical shape. It is a side view of a movable iron core.

FIG. 7 is a diagram showing a modification of the polarized linear actuator of the fourth embodiment.

FIG. 8 is a diagram showing a main part of a polarized linear actuator according to a fifth embodiment.

FIG. 9 is a diagram showing a main part of another example of the polarized linear actuator of the fifth embodiment.

FIG. 10 is a diagram showing a main part of a polarized linear actuator according to a sixth embodiment.

FIG. 11 is a diagram showing a main part of a polarized linear actuator according to a seventh embodiment.

FIG. 12 is a diagram showing a main part of a polarized linear actuator according to an eighth embodiment.

[Explanation of symbols]

Ac Actuator 3 Movable iron core 1 _R , 1 _L , 1 _U , 1 _D Permanent magnet 5 _U , 5 _D Yoke 4 _R , 4 _L coil (excitation coil) 8 _U , 8 _D External yoke 9 _R , 9 _L Magnetic material 18 _R , 18 _L magnetic pole

Claims (6)

(57) [Claims] 1. A pair of magnetic bodies each having a hollow portion penetrating therethrough , each of which is used to generate a magnetic pole , penetrates the hollow portion.
A part of which is inserted into each of the hollow portions so as to have a gap between each of the magnetic bodies and a suction means which is disposed so as to face each other in the opposite direction, and which is held so as to be linearly movable. In addition, between the movable iron core whose length in the moving direction is shorter than the distance between the outer ends of the pair of magnetic bodies and longer than the distance between the inner ends , and the magnetic body facing the suction means. a permanent magnet passing the first magnetic flux in each of the gap provided, the direction of the width along the moving direction of the movable iron core between the confronting magnetic body of said suction means is not shorter than the length of the movable core Long
And a second magnet that is provided so as to be adjacent to the permanent magnet and that passes through the one gap in a direction in which the first magnetic flux is added and passes through in the other gap in a direction that is subtracted from the magnetic flux. A polarized linear actuator having an exciting coil that forms a magnetic flux. 2. The polarized linear actuator according to claim 1, wherein a non-magnetic material having a small friction coefficient is arranged in the gap. 3. A rotating body which rotates with the movement of a movable iron core is provided in the gap.
Polarized linear actuator described in. 4. In at least one of the hollow portions of the magnetic body, the gap gradually decreases from the vicinity of the center of the moving direction of the movable iron core toward the end portion and becomes minimum on the end portion side, or The gap is formed so as to gradually increase from the vicinity of the center of the moving direction of the movable iron core toward the end portion and become the maximum on the end portion side, or either one of them. The polar linear actuator according to claim 3. 5. A holding magnetic pole that mechanically stops the movement of the movable iron core and magnetically holds the movable iron core on the front end side or the rear end side of the magnetic body in the moving direction of the movable iron core. The polarized linear actuator according to any one of claims 1 to 4, further comprising holding magnetic pole generation means. 6. The suction means is provided with a protrusion portion facing the movable iron core with a small gap so that the movable iron core can be magnetically held on the front end side or the rear end side in the moving direction of the movable iron core of the suction means. The polar linear actuator according to any one of claims 1 to 5, wherein the polar linear actuator is provided on the magnetic body.