JP2003235231A - Linear actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear actuator in which magnetic flux generated from a permanent magnet can be used effectively for moving a mover and the mover can generate a thrust sufficiently and stably. <P>SOLUTION: The linear actuator comprises a stator 12, a mover 13 having iron pieces 32 provided reciprocally with respect to the stator 12, permanent magnets 14 provided oppositely to the iron pieces 32 in the stator 12 while arranging the magnetic poles along the reciprocating direction, a pair of magnetic pole members 22 and 23 provided on the opposite sides of the permanent magnet 14 in the reciprocating direction, and a coil 15 provided in the stator 12 wherein the iron piece 32 has tapered faces 51 and 52 inclining against the reciprocating direction on the side facing the magnetic pole members 22 and 23. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear actuator, and more particularly to improvement of reliability and performance thereof.

[0002]

2. Description of the Related Art A linear actuator is used as a compressor motor or the like because it can be driven with a small loss by resonating with a spring. Since a compressor using this linear actuator can exhibit excellent performance such as high efficiency, it is expected to be used as a refrigerator, a freezer, or an air conditioner.

As a linear actuator, there is a voice coil motor. This voice coil motor is driven by a force generated in a coil by passing a current through the coil in a magnetic field created by a permanent magnet, and is also called a movable coil type in which a mover including the coil moves.

As another linear actuator,
There is also a structure in which a permanent magnet and a coil are exchanged with respect to the above-mentioned movable coil type, and a movable element including a permanent magnet is called a movable magnet type.

[0005]

By the way, in the above-mentioned movable coil type, since a coil is included in the mover, it is necessary to pass an electric current through the mover. Movement may cause disconnection,
There was a problem of poor reliability.

Further, in the above-mentioned movable magnet type, the weight of the permanent magnet is increased when trying to obtain a high magnetic flux density in order to improve the performance, and as a result, the weight of the mover is increased. Therefore, there is a problem that the performance cannot be improved as desired.

Therefore, the applicant of the present invention, the stator, the mover provided with an iron piece so as to reciprocate with respect to the stator, the permanent magnet provided on the stator in a state of facing the iron piece, A linear actuator that includes a coil provided on the stator and moves the magnetic flux passing through the iron piece with the coil on the stator side where the current direction changes and the permanent magnet to reciprocate the iron piece, that is, the mover has been developed. An application has been filed (Japanese Patent Application No. 2001-369378). In this linear actuator, since the coil and the permanent magnet are both provided on the stator, it is not necessary to feed power to the mover side, and the moving mover does not cause a disconnection in the feed line to the coil. At the same time, even if the weight of the permanent magnet increases when trying to obtain a high magnetic flux density in order to improve the performance, the weight of the mover does not increase, and further, since the mover has no magnet, Magnetization of the mover is extremely excellent because it eliminates the need for work.

However, in this linear actuator, unless the magnetic flux generated by the permanent magnet is effectively used for the movement of the mover, the mover cannot sufficiently and stably generate thrust. There was room for further improvement.

Therefore, according to the present invention, the magnetic flux generated by the permanent magnet can be effectively used for the movement of the mover,
An object of the present invention is to provide a linear actuator that can generate thrust in a mover sufficiently and stably.

[0010]

In order to achieve the above object, a linear actuator according to claim 1 of the present invention comprises:
A stator, a mover having an iron piece that is provided so as to reciprocate with respect to the stator, and a stator provided with the magnetic poles facing the iron piece and aligned in the reciprocating direction. A permanent magnet, a pair of magnetic pole members provided on both sides in the reciprocating direction of the permanent magnet, and a coil provided on the stator, wherein the iron piece is provided on the magnetic pole member. It is characterized in that it has an iron piece side taper surface that is inclined with respect to the reciprocating direction on the opposite side.

As described above, since the iron piece has the iron piece side tapered surface on the side facing the magnetic pole member, the magnetic flux generated by the permanent magnet and guided between the magnetic pole member and the iron piece is guided by the iron piece side tapered surface. As a result, the number of magnetic fluxes generated by the permanent magnet and guided between the magnetic pole member and the iron piece can be increased.

According to a second aspect of the present invention, there is provided a linear actuator, a stator, a movable element which has an iron piece and is provided so as to be capable of reciprocating with respect to the stator, and a direction of the reciprocating movement which faces the iron piece. A permanent magnet provided on the stator in a state where magnetic poles are arranged along the magnetic pole, a pair of magnetic pole members provided on both sides in the reciprocating direction of the permanent magnet, and a coil provided on the stator. The magnetic pole member is characterized in that it has a magnetic pole member side taper surface that is inclined with respect to the reciprocating direction on the side facing the iron piece.

As described above, since the magnetic pole member has the magnetic pole member side tapered surface on the side facing the iron piece, the magnetic flux generated by the permanent magnet and guided between the magnetic pole member and the iron piece is formed by the magnetic pole member side tapered surface. As a result, the number of magnetic fluxes generated by the permanent magnet and guided between the magnetic pole member and the iron piece can be increased.

A linear actuator according to a third aspect of the present invention is the linear actuator according to the second aspect, wherein the iron piece has an iron piece side taper surface inclined on the side facing the magnetic pole member with respect to the reciprocating direction. It is characterized by having.

As described above, since the iron piece also has the iron piece side tapered surface on the side facing the magnetic pole member, the magnetic flux generated by the permanent magnet and guided between the magnetic pole member and the iron piece is guided by the iron piece side tapered surface. As a result, the number of magnetic fluxes generated by the permanent magnets and guided between the magnetic pole member and the iron piece can be further increased.

According to a fourth aspect of the present invention, in the linear actuator according to the first or third aspect, the iron piece side tapered surfaces are provided on both sides of the iron piece in the reciprocating direction. It has a feature.

Since the iron piece side tapered surfaces are provided on both sides of the iron piece in the reciprocating direction, the number of magnetic fluxes generated by the permanent magnets and guided between the magnetic pole member and the iron piece is surely increased. Can be made.

A linear actuator according to a fifth aspect of the present invention is the linear actuator according to the second or third aspect, wherein the magnetic pole member side taper surface is provided on both of the pair of magnetic pole members. There is.

As described above, since the magnetic pole member side tapered surface is provided on each of the pair of magnetic pole members, the number of magnetic fluxes generated by the permanent magnet and guided between the magnetic pole member and the iron piece can be reliably increased. You can

According to a sixth aspect of the present invention, in the linear actuator according to any one of the first to fifth aspects, the set of the permanent magnet and the pair of magnetic pole members is reciprocated in the stator. Are provided in the direction of,
A plurality of iron pieces are provided in the mover in the reciprocating direction.

As described above, since the stator is provided with a plurality of sets of permanent magnets and a pair of magnetic pole members in the reciprocating direction, and the mover is provided with a plurality of iron pieces in the reciprocating direction, It is possible to generate a larger thrust on the mover.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION A linear actuator according to a first embodiment of the present invention will be described below with reference to FIGS.

The linear actuator 11 of the first embodiment
Is a yoke (stator) 12, a movable element 13 reciprocally provided on the yoke 12, a permanent magnet 14 fixed to the yoke 12, and a coil 15 fixed to the yoke 12.
It has and.

The yoke 12 has a cylindrical outer cylindrical portion 17
And a thin plate ring-shaped bottom plate portion 18 provided on one end side in the axial direction of the outer cylindrical portion 17, and a ring projecting to the same side as the outer cylindrical portion 17 in the inner portion of the bottom plate portion 18 along the axial direction. And a cylindrical inner magnetic pole 19 provided coaxially with the outer cylindrical portion 17 on the connecting portion 20.

The yoke 12 having the outer cylindrical portion 17, the bottom plate portion 18, the connecting portion 20 and the inner magnetic pole 19 is integrally formed by sintering using a sintered material which is a common magnetic material.

The coil 15 has a ring shape, and is fixed coaxially with the yoke 12 inside the corner of the boundary between the bottom plate portion 18 and the outer cylindrical portion 17 of the yoke 12.

The permanent magnet 14 is a thin plate ring having a constant thickness in which both magnetic poles, that is, the N pole 14a and the S pole 14b are arranged in the axial direction, and is made of a ferrite magnet. On both sides of the permanent magnet 14 in the axial direction,
An annular outer magnetic pole (magnetic pole member) 22 and an outer magnetic pole (magnetic pole member) 23 having a constant thickness are arranged so as to sandwich the permanent magnet 14. The pair of outer magnetic poles 22 and 23 are also made of a sintered material.

Here, the outer diameter of the permanent magnet 14 is the yoke 12
The outer diameter of the pair of outer magnetic poles 22 and 23 is smaller than the inner diameter of the outer cylindrical portion 17 of the yoke 12. .

Then, the permanent magnet 14 and the outer magnetic pole 22
The outer magnetic poles 23 are coaxially arranged and integrally fixed by sandwiching the outer magnetic poles 22 and 23 on both sides in the direction of the arrangement of the magnetic poles 14a and 14b of the permanent magnet 14.

The thus integrated structure is press-fitted inside the outer cylindrical portion 17 of the yoke 12 on the outer diameter side of the permanent magnet 14, whereby the permanent magnet 14 and the pair of outer magnetic poles 22, 23 are formed. , Is fixed coaxially with the yoke 12.

As a result, in this fixed state, the yoke 12 is provided between the outer magnetic pole 22 and the outer cylindrical portion 17 of the yoke 12 and between the outer magnetic pole 23 and the outer cylindrical portion 17 of the yoke 12, respectively. An annular gap (magnetic gap) 5 serving as a magnetic resistance means that serves as a magnetic resistance against a magnetic flux loop formed by the magnetic force of the permanent magnet 14 on the outer cylindrical portion 17, the permanent magnet 14, and the pair of outer magnetic poles 22, 23.
0 will be formed.

Further, in this fixed state, the permanent magnet 14 has N
The pole 14a is arranged on the bottom plate portion 18 side, and one outer magnetic pole 22 is adjacent to the coil 15 in the axial direction.

Furthermore, in this fixed state, the permanent magnet 14 and the pair of outer magnetic poles 22 and 23 are coaxial with the cylindrical inner magnetic pole 19 of the yoke 12 as a whole, and the inner magnetic pole 19 and the axis line. By arranging the positions and the lengths in the same direction, an annular gap 25 is formed between the inner magnetic pole 19 and the inner magnetic pole 19.

A bush 27 is provided on the inner peripheral side of the inner magnetic pole 19 of the yoke 12 so as to move the shaft 26 in the axial direction.
The ball bush 28 supported by
Fixed coaxially at. The mover 13 is fixed to a shaft 26 movably held by the bush 27. Then, the shaft 26 and the mover 13 reciprocate integrally with the bush 27 fixed to the yoke 12 along the axial direction.

The mover 13 has a substantially disk-shaped base portion 30 fixed to the shaft 26, and a cylindrical portion 31 provided so as to enter the annular gap 25 in a state of being fixed to the shaft 26 by the base portion 30. The cylindrical portion 31 has an iron piece 32 as a cylindrical movable magnetic pole that is fixed on the opposite side of the base portion 30 with the same coaxial diameter. As a result, the iron piece 32 of the mover 13 becomes
It is arranged coaxially inside, but is arranged so that the central position in the axial direction thereof is substantially aligned with the central position in the axial direction of the permanent magnet 14.

Here, the iron piece 32 is on the outer diameter side facing the outer magnetic pole 22, and is further on the one end side close to the outer magnetic pole 22 in the reciprocating direction, that is, in the axial direction, on the central side in the reciprocating direction. A taper surface (iron-side taper surface) 51 inclined so as to come closer to the permanent magnet 14
Are formed. In addition, the iron piece 32 is used as the outer magnetic pole 2.
3 on the outer diameter side, which is opposite to the outer diameter side of the permanent magnet 1 in the reciprocating direction, that is, in the axial direction, the permanent magnet 1 is located closer to the center in the reciprocating direction.
4, a taper surface (iron-side taper surface) 52 is formed so as to be close to No. 4.

The mover 13 has a base portion 30 and a cylindrical portion 31.
Are made of synthetic resin such as engineering plastic which is a non-magnetic material, and the iron piece 32 is made of a magnetic material that is not magnetized and is made of a sintered material. The mover 13 is formed by insert molding of synthetic resin having the iron piece 32 as a nest.

As a result of the above, the mover 13 has the iron piece 32 and is supported by the yoke 12 so as to be capable of reciprocating along the axial direction (the left-right direction in each drawing), and the permanent magnet. 14 is fixed to the yoke 12 in a state of facing the outer diameter side of the iron piece 32 of the mover 13, and in a state of arranging the magnetic poles 14a and 14b along the reciprocating direction of the mover 13. Then, a pair of outer magnetic poles 22 and 23 are provided on both sides of the permanent magnet 14 in the reciprocating direction of the mover 13, and the yoke 12 includes
This means that the iron piece 32 is integrally formed with the inner magnetic pole 19 facing the opposite side of the permanent magnet 14. Furthermore, the set of the permanent magnet 14 and the pair of outer magnetic poles 22 and 23 is
It is provided only on one side with respect to the iron piece 32, and specifically, is provided only on the outer side in the radial direction with respect to the cylindrical iron piece 32.

In the linear actuator 11 having the above-mentioned structure, when an alternating current (sine wave current, rectangular wave current) is passed through the coil 15, the current flows in the coil 15 in a predetermined direction. As described above, the magnetic flux is guided from the S pole 14b to the N pole 14a side by the permanent magnet 14, so that the outer cylindrical portion 17 of the yoke 12, the outer magnetic pole 23,
Permanent magnet 14, outer magnetic pole 22, iron piece 3 of mover 13
2, the inner magnetic pole 19 of the yoke 12, the connecting portion 20, the bottom plate portion 18, and the outer cylindrical portion 17 form a magnetic flux loop in this order. As a result, the mover 13 moves in the direction of moving to the outer magnetic pole 22 side. A force F is applied to move in this direction.
On the other hand, in a state in which a current flows in the coil 15 in a direction opposite to the predetermined direction, as shown by the chain double-dashed line in FIG.
By being guided from the S pole 14b to the N pole 14a side by the permanent magnet 14, the outer cylindrical portion 17, the bottom plate portion 18, and
Connecting part 20, inner magnetic pole 19, iron piece 3 of mover 13
2, outer magnetic pole 23, permanent magnet 14, outer magnetic pole 2
2, a magnetic flux loop is formed in the order of the outer cylindrical portion 17, and as a result, the mover 13 is moved in this direction by the force F being applied in the opposite direction to the outer magnetic pole 23 side.

By alternately changing the direction of the current flow to the coil 15 due to the alternating current, the above operation is repeated and the mover 13 reciprocates in the axial direction with respect to the yoke 12.

Since the iron piece 32 of the mover 13 has tapered surfaces 51 and 52 at both ends on the outer diameter side facing the outer magnetic poles 22 and 23, respectively, the outer magnetic pole 22 and the outer magnetic pole 22 generated by the permanent magnet 14 are generated. The magnetic flux guided between 23 and the iron piece 32 is easily guided by these tapered surfaces 51, 52, and the number of magnetic fluxes generated by the permanent magnet 14 and guided between the outer magnetic poles 22, 23 and the iron piece 32 increases.

Moreover, since the gap 50 serves as a magnetic resistance against the magnetic flux loop formed by the magnetic force of the permanent magnet 14 on the outer cylindrical portion 17 of the yoke 12, the permanent magnet 14, and the pair of outer magnetic poles 22, 23, Also in this respect, the outer magnetic poles 22, 23 caused by the permanent magnet 14 are generated.
The number of magnetic flux guided between the iron piece 32 and the iron piece 32 increases.

According to the linear actuator 11 of the first embodiment described above, the iron piece 32 is the outer magnetic pole 2.
The outer magnetic poles 22, which are generated by the permanent magnets 14 have the tapered surfaces 51, 52 on the outer diameter side that opposes 2, 2, 23.
The magnetic flux guided between the metal piece 23 and the iron piece 32 is easily guided by the tapered surfaces 51, 52, and as a result, the number of magnetic fluxes generated by the permanent magnet 14 and guided between the outer magnetic poles 22, 23 and the iron piece 32 is reduced. Can be increased. Therefore, the magnetic flux generated by the permanent magnet 14 can be effectively used for the movement of the mover 13, and the mover 13
The thrust can be generated sufficiently and stably.

Moreover, the tapered surfaces 51 and 52 are formed on the iron piece 32.
Are provided on both sides in the direction of reciprocation of
It is possible to reliably increase the number of magnetic fluxes that are guided between the No. 3 and the iron piece 32. Therefore, the magnetic flux generated by the permanent magnet 14 can be effectively used for the movement of the mover 13, and the effect that the thrust can be sufficiently and stably generated in the mover is further enhanced.

The base portion 30 and the cylindrical portion 31 of the mover 13 may be made of aluminum die-cast or non-magnetic stainless steel instead of synthetic resin as long as they are non-magnetic materials. In this case, there is an advantage that rigidity can be improved. is there. However, it is more preferable to use a synthetic resin in terms of weight reduction.

As the permanent magnet 14, other than the above-mentioned ferrite magnet, it is also possible to use a rare earth material such as neodymium or samarium cobalt, or a plastic magnet, but a ferrite magnet is used. It is more preferable from the viewpoint of cost reduction.

In addition to the ball bush, the bearing of the mover 13 may be an air bearing (gas bearing), a sliding bearing, or the like. However, it is more preferable to use the ball bush 28 because the mover 13 can reciprocate more accurately.

Further, this linear actuator 11
Is generally used by incorporating a spring in the movable part or by resonating with a spring placed outside,
Of course, it can be used as it is.

Further, the linear actuator 11 can be used as a linear servo actuator capable of controlling the speed and position by providing a sensor for detecting the position, speed and the like and performing closed loop control.

Further, in order to improve the performance such as the displacement characteristics, the inner magnetic pole 19 and the outer magnetic poles 22, 23 may be chamfered or the like.

In addition to the sintered material, the inner magnetic pole 19, the outer magnetic poles 22 and 23, and the iron piece 32 may have a laminated structure of electric iron plates for reducing iron loss during high-speed operation.

Further, it is possible to adopt a structure in which the mover 14 is not supported on the yoke 12 by the ball bush 28 or the like.

Further, the gap 50 is formed by the outer magnetic pole 2
An air gap or a non-magnetic spacer may be used because a magnetic gap may be provided between the second and the second cylinders 23 and the outer cylindrical portion 17 of the yoke 12. If a non-magnetic spacer is interposed as a magnetic gap between the outer magnetic poles 22 and 23 and the outer cylindrical portion 17, the outer magnetic poles 22 and 23 are formed by the spacers.
Can be mechanically fixed to. This spacer can be formed of plastic, aluminum, stainless steel, copper, or the like.

Next, the linear actuator of the second embodiment of the present invention will be described below with reference to FIG. 4 focusing on the difference from the first embodiment. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Linear actuator 11 of the second embodiment
In the above, the iron piece 32 of the mover 13 does not have a taper surface, but has a simple cylindrical shape.

On the other hand, in the linear actuator 11 of the second embodiment, on the inner diameter side of the outer magnetic pole 22 facing the iron piece 32, the side closer to the permanent magnet 14 in the reciprocating direction of the mover 13, that is, the axial direction. Iron piece 32
A taper surface (taper surface on the magnetic pole member side) inclined so as to come close to is formed over the entire length in the axial direction. Further, on the inner diameter side of the outer magnetic pole 23 facing the iron piece 32, a taper surface (on the side of the magnetic pole member) inclined so as to be closer to the iron piece 32 on the side closer to the permanent magnet 14 in the reciprocating direction of the mover 13, that is, the axial direction. Tapered surface) 55
Are formed over the entire length in the axial direction.

According to the linear actuator 11 of the second embodiment, the outer magnetic poles 22 and 23 are tapered surfaces 54 and 55 on the inner diameter side facing the iron piece 32, respectively.
Therefore, the magnetic flux generated by the permanent magnet 14 and guided between the outer magnetic poles 22, 23 and the iron piece 32 is easily guided by these tapered surfaces 54, 55, and the outer magnetic pole 22, generated by the permanent magnet 14 is generated. It is possible to increase the number of magnetic fluxes guided between the 23 and the iron piece 32. Therefore, the magnetic flux generated by the permanent magnet 14 can be effectively used for the movement of the mover 13, and the mover 13
The thrust can be generated sufficiently and stably.

Next, the linear actuator of the third embodiment of the present invention will be described below with reference to FIG. 5 focusing on the differences from the second embodiment. The same parts as those in the second embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Linear actuator 11 of the third embodiment
, The both end surfaces in the axial direction of the permanent magnet 14 are inclined so that the inner diameter side is closer to each other, and the outer magnetic poles 22, 23 arranged on both sides in the axial direction of the permanent magnet 14 are the permanent magnets, respectively. It has a shape that inclines according to the inclination of the end surface of 14.

As a result, on the inner diameter side of the outer magnetic pole 22 facing the iron piece 32, the iron piece 3 becomes closer to the opposite side to the permanent magnet 14 in the reciprocating direction of the mover 13, that is, the axial direction.
A tapered surface (tapered surface on the magnetic pole member side) 54 that is inclined so as to approach 2 is formed. In addition, the outer magnetic pole 23
On the inner diameter side facing the iron piece 32, there is provided a taper surface (taper surface on the magnetic pole member side) 55 that is inclined so as to come closer to the iron piece 32 toward the opposite side to the permanent magnet 14 in the reciprocating direction of the mover 13, that is, the axial direction. Has been formed.

According to the linear actuator 11 of the third embodiment, the outer magnetic poles 22, 23 are tapered surfaces 54, 55 on the inner diameter side facing the iron piece 32, respectively.
Since it has, the same effect as the second embodiment can be obtained.

Next, the linear actuator of the fourth embodiment of the present invention will be described below with reference to FIG. 6 focusing on the differences from the third embodiment. The same parts as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

Linear actuator 11 of the fourth embodiment
In the above, the notch 56 is formed on the outer diameter side which is the opposite side to the iron piece 32 of the outer magnetic pole 22 and the opposite side to the permanent magnet 14, and the iron piece 32 of the outer magnetic pole 23 is formed.
A cutout 57 is also formed on the outer diameter side, which is the opposite side to the opposite side, and on the opposite side to the permanent magnet 14.

According to the linear actuator 11 of the fourth embodiment as described above, the same effect as that of the third embodiment is obtained, and the notches 56, 5 are formed in the outer magnetic poles 22, 23.
Since 7 is formed, the outer magnetic poles 22 and 23 can be downsized.

Next, a linear actuator according to a fifth embodiment of the present invention will be described below with reference to FIG. 7, focusing on differences from the first embodiment. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the fifth embodiment, the permanent magnet 14 and the pair of outer magnetic poles 22 and 23 similar to those in the first embodiment are provided in the outer cylindrical portion 17 of the yoke 14 in the reciprocating direction of the mover 13. A plurality of sets, specifically two sets, are provided, and the mover 13 is provided with a plurality of iron pieces 32 in the reciprocating direction, specifically two pieces. However, the adjacent permanent magnets 14 have different magnetic pole directions.

Specifically, the permanent magnet 14 on the bottom plate 18 side
Places the N pole 14a on the side of the bottom plate 18 and the S pole 1
4b is arranged on the opposite side to the bottom plate portion 18, and the permanent magnet 14 on the opposite side to the bottom plate portion 18 arranges the N pole 14a on the opposite side to the bottom plate portion 18 and the S pole 14b.
It is placed on the side.

One iron piece 32 is provided so as to face one set of the permanent magnet 14 and the pair of outer magnetic poles 22, 23, and the other iron piece 32 is the other of the permanent magnet 14 and the pair of outer magnetic poles 22, 23. Are provided facing each other.

In accordance with this, the inner side of the outer cylindrical portion 17 between one permanent magnet 14 and a pair of outer magnetic poles 22 and 23 and the other permanent magnet 14 and a pair of outer magnetic poles 22 and 23. , The coil 15 is arranged, and the ball bush 28 includes a plurality of bushes 27.
Specifically, it has two.

According to the fifth embodiment, the yoke 14 has a permanent magnet 14 and a pair of outer magnetic poles 22,
Since a plurality of sets of 23 are provided in the reciprocating direction and a plurality of iron pieces 32 are provided in the moving element 13 in the reciprocating direction, a larger thrust can be generated in the moving element 13.

Here, in the fifth embodiment, a plurality of sets of the permanent magnet 14 and the pair of outer magnetic poles 22 and 23 of the first embodiment are provided in the reciprocating direction of the mover 13, and
The case where a plurality of iron pieces 32 are provided on the mover 13 in the reciprocating direction has been described as an example, but the set of the permanent magnet 14 and the pair of outer magnetic poles 22 and 23 of the second embodiment is used as the mover 13.
A plurality of iron pieces 32 are provided in the mover 13 in the reciprocating direction, and the permanent magnet 14 and the pair of outer magnetic poles 22 and 23 of the third embodiment are provided in the mover 13. In addition to providing multiple in the direction of reciprocation,
A plurality of iron pieces 32 are provided on the mover 13 in the reciprocating direction,
Providing a plurality of sets of the permanent magnet 14 and the pair of outer magnetic poles 22 and 23 of the fourth embodiment in the reciprocating direction of the mover 13, and providing a plurality of iron pieces 32 in the mover 13 in the reciprocating direction. Of course, it is possible.

Further, the tapered surface 5 of the first embodiment described above.
It is also possible to combine the iron piece 32 having 1,52 with any of the second to fourth embodiments. With this combination, the iron piece 32 is provided with the tapered surfaces 51 and 52, and the outer magnetic poles 22 and 23 are also provided with the tapered surfaces 54 and 55, so that the effect is further enhanced.

[0073]

As described in detail above, the first aspect of the present invention
According to the described linear actuator, since the iron piece has the iron piece side tapered surface on the side facing the magnetic pole member, the magnetic flux generated by the permanent magnet and guided between the magnetic pole member and the iron piece is guided by the iron piece side tapered surface. As a result, the number of magnetic fluxes generated by the permanent magnets and guided between the magnetic pole member and the iron piece can be increased. Therefore, the magnetic flux generated by the permanent magnet can be effectively used for the movement of the mover, and the thrust can be sufficiently and stably generated in the mover.

According to the linear actuator of the second aspect of the present invention, since the magnetic pole member has the magnetic pole member side tapered surface on the side facing the iron piece, it is guided between the magnetic pole member and the iron piece by the permanent magnet. The magnetic flux is easily guided by the magnetic pole member side tapered surface, and as a result, the number of magnetic fluxes generated by the permanent magnet and guided between the magnetic pole member and the iron piece can be increased. Therefore, the magnetic flux generated by the permanent magnet can be effectively used for the movement of the mover, and the thrust can be sufficiently and stably generated in the mover.

According to the linear actuator of the third aspect of the present invention, since the iron piece also has the iron piece side tapered surface on the side facing the magnetic pole member, the magnetic flux generated by the permanent magnet is introduced between the magnetic pole member and the iron piece. However, this iron piece side taper surface facilitates guiding to the iron piece, and as a result, the number of magnetic fluxes generated by the permanent magnet and guided between the magnetic pole member and the iron piece can be increased. Therefore, the magnetic flux generated by the permanent magnet can be effectively used for moving the mover,
The effect that the thrust can be generated in the mover sufficiently and stably is further enhanced.

According to the linear actuator of claim 4 of the present invention, since the iron piece side tapered surfaces are provided on both sides in the reciprocating direction of the iron piece, respectively, the magnetic pieces are generated by the permanent magnets and the magnetic pole member and the iron piece are formed. It is possible to surely increase the number of magnetic fluxes guided between. Therefore, the magnetic flux generated by the permanent magnet can be effectively used for the movement of the mover, and the effect that the thrust can be sufficiently and stably generated in the mover is further enhanced.

According to the linear actuator of the fifth aspect of the present invention, since the magnetic pole member side tapered surface is provided on each of the pair of magnetic pole members, it is generated by the permanent magnet and is generated between the magnetic pole member and the iron piece. The number of magnetic fluxes to be guided can be reliably increased. Therefore, the magnetic flux generated by the permanent magnet can be effectively used for the movement of the mover, and the effect that the thrust can be sufficiently and stably generated in the mover is further enhanced.

According to the linear actuator of claim 6 of the present invention, the stator is provided with a plurality of sets of permanent magnets and a pair of magnetic pole members in the direction of reciprocation, and the mover is reciprocated with iron pieces. Since a plurality of them are provided in the direction of, it is possible to generate a larger thrust on the mover.

[Brief description of drawings]

FIG. 1 is a side cross-sectional view showing a linear actuator of a first embodiment of the present invention, showing a state of magnetic flux in a state where no current flows in a coil by a chain double-dashed line.

FIG. 2 is a side sectional view showing the linear actuator according to the first embodiment of the present invention, and shows a state of magnetic flux in a state where a current flows in one direction in a coil by a two-dot chain line.

FIG. 3 is a side sectional view showing the linear actuator according to the first embodiment of the present invention, and shows a state of magnetic flux in a state where current flows in the coil in the opposite direction by a two-dot chain line.

FIG. 4 is a side sectional view showing a linear actuator according to a second embodiment of the present invention, and shows a state of magnetic flux in a state where no current flows through the coil by a chain double-dashed line.

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

FIG. 6 is a side sectional view showing a linear actuator according to a fourth embodiment of the present invention.

FIG. 7 is a side sectional view showing a linear actuator according to a fifth embodiment of the present invention, and shows a state of magnetic flux in a state where no current flows through the coil by a chain double-dashed line.

[Explanation of symbols]

11 Linear actuator 12 yoke (stator) 13 mover 14 permanent magnet 14a N pole (magnetic pole) 14b S pole (magnetic pole) 15 coils 22, 23 Outer magnetic pole (magnetic member) 32 iron pieces 51, 52 Tapered surface (iron side taper surface) 54,55 Tapered surface (tapered surface on magnetic member side)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Maeda             100, Takegahana Town, Ise City, Mie Prefecture             Ise Manufacturing Co., Ltd. F-term (reference) 5H633 BB07 BB10 GG02 GG04 GG09                       HH02 HH24 JB05

Claims (6)

[Claims] 1. A stator, a mover having an iron piece that is provided so as to reciprocate with respect to the stator, and a state in which magnetic poles are arranged facing the iron piece and along the reciprocating direction. A linear actuator comprising a permanent magnet provided on a stator, a pair of magnetic pole members provided on both sides of the permanent magnet in the reciprocating direction, and a coil provided on the stator, wherein the iron piece Is an iron piece side taper surface inclined to the reciprocating direction on the side facing the magnetic pole member. 2. A stator, a mover that has an iron piece and is provided so as to reciprocate with respect to the stator, and a state in which magnetic poles are arranged opposite to the iron piece and along the reciprocating direction. A linear actuator having a permanent magnet provided on a stator, a pair of magnetic pole members provided on both sides of the permanent magnet in the reciprocating direction, and a coil provided on the stator, The linear actuator, wherein the member has a magnetic pole member side tapered surface that is inclined with respect to the reciprocating direction on the side facing the iron piece. 3. The linear actuator according to claim 2, wherein the iron piece has an iron piece side taper surface that is inclined with respect to the reciprocating direction on the side facing the magnetic pole member. 4. The linear actuator according to claim 1, wherein the iron piece side taper surface is provided on each side of the iron piece in the reciprocating direction. 5. The linear actuator according to claim 2, wherein the magnetic pole member side tapered surface is provided on both of the pair of magnetic pole members. 6. The stator is provided with a plurality of sets of the permanent magnet and the pair of magnetic pole members in the reciprocating direction, and the mover is provided with a plurality of iron pieces in the reciprocating direction. The linear actuator according to any one of claims 1 to 5, wherein: