JP2003244924A - Linear actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear actuator having a feeding structure which obviates cables. <P>SOLUTION: A linear actuator R has a stator 1 comprising magnet rows wherein a plurality of permanent magnets are so arranged that magnetic poles thereof alternate; and a mover 2 which can be freely moved along the stator 1. The mover 2 has a plurality of exciting blocks 4 comprising cores 4 wherein a pair of opposite portions 52 and 53 opposed to each with the stator 1 between are made eccentric relative to the center thereof; and coils 7 wound on a plurality of core rows 6 arranged so that directions of lines of magnetic forces between opposite portions 52 and 53 alternate. With respect to the coils 7 respectively installed on the exciting blocks 4, their one-side ends are jointed together, and their other ends are made to be into direct or into indirect contact with a power supply line 3 which is stationarily installed along the direction of the movement of the mover 2 and through which alternating currents are passed. <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 a structure for feeding power to a coil provided on a mover.

[0002]

2. Description of the Related Art Conventionally, a linear actuator is provided at a magnet array piece in which a plurality of permanent magnets are arranged so that their magnetic poles are alternately arranged, and an open end of a core wound with a coil and having a substantially U-shaped cross section. And an armature in which a plurality of magnetic pole teeth are arranged so that the magnetic poles are alternately arranged. In this linear actuator, an alternating current is passed through a coil provided on the armature to alternate the direction of magnetic force lines generated from each magnetic pole tooth,
The magnet array piece and the armature move relative to each other. That is, the linear actuator has a structure in which, when one of the magnet array piece and the armature is fixed as a stator, the other moves as a mover.

[0003]

However, in the case where the magnet array pieces are used as the stator, a cable or the like for supplying an alternating current to the coil of the armature, which is the mover, is an obstacle when the mover moves. . In particular, when the moving distance of the mover becomes long, a long cable is required, and the force for pulling the long cable acts in the direction of hindering the move of the mover.

Therefore, an object of the present invention is to provide a linear actuator having a power supply structure that does not require a cable.

[0005]

SUMMARY OF THE INVENTION A linear actuator according to the present invention, which has solved the above-mentioned problems, comprises a stator composed of a magnet array piece in which a plurality of permanent magnets are arranged so that their magnetic poles alternate, and a stator along the stator. And a movable element that is freely movable, wherein the movable element includes a core in which a pair of facing portions facing each other with the magnet array piece interposed therebetween is biased toward the center of the core, and the core is provided between the facing portions. Has a plurality of excitation blocks each consisting of a coil wound around a plurality of core rows arranged so that the directions of the magnetic force lines of the coils are alternately arranged, and the coils respectively provided on the excitation blocks have their one ends joined to each other, and The other end directly or indirectly contacts a power supply line fixedly installed along the moving direction of the mover. According to this linear actuator, the moving movable element is supplied with electric power by directly or indirectly contacting the other end of each coil of the moving movable element with the electric power supply line. Therefore, it is not necessary to provide a cable to the mover, and the mover can move smoothly without pulling the cable.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] The details of a linear actuator according to the present invention will be described below with reference to the drawings. In the drawings to be referred to, FIG. 1 is a perspective view showing a stator and a mover of a linear actuator according to a first embodiment, FIG. 2 is an enlarged perspective view of an essential part showing a configuration of an excitation block of FIG. 1, and FIG. It is a perspective view which shows the electric power supply line in the linear actuator of 1.

As shown in FIG. 1, the linear actuator R has a stator 1 whose both ends are fixed to a wall or the like, a mover 2 movable along the stator 1, and an alternating current to the mover 2. The power supply device 3 includes a rail (power supply line) 31 that supplies a current. This stator 1
A plurality of permanent magnets M, ... Are composed of magnet row pieces in which magnetic poles are arranged alternately.

The mover 2 is formed by integrally connecting three exciting blocks 4, ... Arranged at predetermined intervals along the moving direction of the mover 2. The excitation block 4 has a core 5 that forms a magnetic path and a coil 7 that is wound around a core row 6 in which six cores 5 are arranged.

As shown in FIG. 2, the core 5 is arranged side by side along a core portion 51 having a substantially U-shaped cross section, and along the opening direction of the core portion 51 (hereinafter referred to as "upper"). It has a pair of upper facing portions 52 and lower facing portions 53 facing each other with the stator (magnet array piece) 1 sandwiched therebetween. The core portion 51 includes a base portion 51a around which the coil 7 is wound and first and second side portions 51 formed at both ends thereof and having different heights.
b and 51c have a substantially U-shaped cross section. An upper extension portion 54 extending toward the second side portion 51c is formed at the upper end (opening end) of the first side portion 51b,
The upper facing portion 52 is formed at the tip of the upper extending portion 54. In addition, a lower extension portion 55 extending toward the first side portion 51b is formed at the upper end (opening end) of the second side portion 51c, and the lower facing portion 53 is provided at the tip of the lower extension portion 55. Are formed. That is, in this core 5, the upper side,
The lower facing portions 52 and 53 are biased toward the center side of themselves. Here, "the center side of itself" means the position of the center of the base portion 51a in the core 5, and includes a slight deviation from that position.

The core 5 is composed of the adjacent cores 5, 5.
5, the positions of the first and second side portions 51b and 51c are arranged so as to be opposite to each other, and
The lower facing portions 52 and 53 are arranged along the stator 1 and are integrally coupled to each other to form the core row 6 (see FIG. 1). When a current flowing in one direction is supplied to the coil 7 wound around the core row 6, magnetic force lines are generated from the upper facing portion 52 to the lower facing portion 53 in one of the adjacent cores 5 and 5. And the other core 5
At, a magnetic force line is generated from the lower facing portion 53 toward the upper facing portion 52. That is, the cores 5 constituting the core row 6 are arranged so that the directions of the magnetic lines of force between the upper and lower facing portions 52, 53 are alternated.

The coils 7 provided in the three excitation blocks 4, ... Shown in FIG. 1, respectively, have their one ends connected to each other, and their other ends fixed to the lower surface of each excitation block 4. The wheels 41 are respectively connected to each other. The wheels 41 are arranged so as to be displaced from each other along the longitudinal direction of the base portion 51a of the core 5, and have a function of receiving an alternating current from the rail 31 and a function of supporting the entire mover 2. There is.

As shown in FIG. 3, the power supply device 3 includes three conductive rails 31 fixedly installed on a fixed base B along the moving direction of the mover 2, and each of these rails. It has an inverter 32 that supplies an alternating current to the rail 31. Then, the wheels 41 are movably engaged with the rails 31 and are constantly in contact with the rails 31, so that a current is supplied from the rails 31 to the moving mover 2.

Next, the operation of the linear actuator R will be described with reference to FIG. First, when a switch (not shown) is operated, a direct current is supplied to the inverter 32, and the inverter 32 converts the direct current into an alternating current. This alternating current is appropriately controlled by a control device (not shown) provided in the inverter 32,
It is supplied to each rail 31. When an alternating current flows through the rail 31, the excitation block 4 is excited to move the mover 2 to the stator 1.
Move along. At this time, since the rail 31 is fixedly installed along the moving direction of the mover 2, the other end of each coil 7 of the moving mover 2 is indirectly attached to the rail 31 via the wheel 41. It is always in contact and the power is always supplied.

According to the above, the following effects can be obtained in the first embodiment. (1) Since electric power is supplied to the mover 2 via the wheels 41 that are always in contact with the rail 31, it is not necessary to provide a cable to the mover 2, and the mover 2 can move smoothly without pulling the cable. You can (2) Opposing portion 5 formed on core portion 51 having a substantially U-shaped cross section
Since the stators 2 and 53 face each other with the stator 1 in between, the degree of freedom in designing the wiring structure when using the linear actuator R is increased. For example, when the linear actuator R is used as a conveyance actuator, the core portion 51 having a substantially U-shaped cross section is arranged so that its opening faces upward, and the upper facing portion 52 on the upper side of the stator 1 is provided. The upper surface is joined to the lower surface of the vehicle body, and the other end of the coil 7 wound around the base 51a of the core row 6 on the lower side of the stator 1 is brought into contact with the rail 31 arranged on the ground directly thereunder via the wheel 41. You can With this configuration, the mover 2
The wiring from the rail to the rail 31 can be shortened, and the structure can be simplified and the cost can be reduced.

The present invention is not limited to the first embodiment, but can be implemented in various forms. (I) In the present embodiment, the other end of each coil 7 is in contact with each rail 31 indirectly via the wheel 41.
The present invention is not limited to this. For example, the structure may be such that the other end of the coil 7 in the present embodiment directly contacts the rail 31. However, in this structure, it is necessary to separately provide the wheel 41 that supports the mover 2, whereas in the present embodiment, the wheel 4 that supports the mover 2 is provided.
Since 1 is also used for power supply, it is not necessary to separately provide wheels, and cost can be reduced.

(Ii) It goes without saying that the linear actuator R of this embodiment can be applied as a wide variety of actuators. In particular, when the linear actuator R of the present embodiment has a particular effect when used as a transport actuator, it will be described below in comparison with the prior art. For example, in a conventional linear actuator having a structure in which one side of a stator and one side of a mover face each other,
Since it is necessary to install a stator on the ground just below the mover,
It is necessary to dispose the power supply line so as to be displaced from the stator, and to route the wiring of the mover up to the shifted power supply line. If the mover is provided on the side of the vehicle body and the stator is provided on the wall facing the mover, the power supply line can be provided directly below the mover, but the mover and the like are provided only on one side of the vehicle body. Since a lateral load may be applied to the vehicle body, it is necessary to provide these movers and the like on both sides of the vehicle body, and it is considered that the cost will increase accordingly.

On the other hand, in the linear actuator R of this embodiment, since the other end of the coil 7 can be brought into contact with the rail 31 arranged on the ground directly below it through the wheel 41, as described above, The wiring from the mover 2 to the rail 31 can be shortened, and the structure can be simplified and the cost can be reduced.

[Second Embodiment] A second embodiment of the linear actuator according to the present invention will be described below. Since this embodiment is a modification of the linear actuator R according to the first embodiment, the same components as those in the first embodiment are designated by the same reference numerals,
The description is omitted. In the drawings to be referred to, FIG. 4 is a perspective view showing a linear actuator according to a second embodiment.

As shown in FIG. 4, in the linear actuator R'according to the present embodiment, an inverter 32 connected to the other end of each coil 7 is integrally provided on the lower surface of the mover 2. . This inverter 32 has two terminals (not shown) on its lower surface for taking in a direct current internally.
Are provided, and wheels 41 having conductivity are connected to the terminals.

The power supply device 3'provides two conductive rails 31, ... Fixedly installed on the fixed base B along the moving direction of the mover 2, and supplies a direct current to the rails 31. DC power supply 33 for Then, the wheels 41 of the mover 2 are movably engaged with the rails 31 and are constantly in contact with the rails 31, so that a direct current is always supplied from the rails 31 to the inverter 32 of the moving mover 2. ing.

Next, the operation of the linear actuator R'will be described with reference to FIG. First, when a switch (not shown) is operated, a DC current is supplied from the DC power supply 33 to the inverter 32 via the rail 31, and the inverter 32 converts the DC current into an AC current. When this alternating current is supplied to each coil 7, each excitation block 4 is excited and the mover 2 moves along the stator 1. At this time, since the rail 31 is fixedly installed along the moving direction of the mover 2, the moving mover 2 has terminals of the inverter 32 on the rail 31 and the wheels 41.
Electric power is always supplied by always contacting indirectly through the.

According to the above, the following effects can be obtained in this embodiment. (3) Since the structure is such that power is supplied from the two terminals of the inverter 32, the rail 3 is designed to correspond to these two terminals.
Since only two 1's are required, the cost can be reduced as compared with the first embodiment.

[Third Embodiment] The third embodiment of the linear actuator according to the present invention will be described below. Since this embodiment is a modification of a part of the linear actuator R ′ according to the second embodiment,
The same components as those in the embodiment are given the same reference numerals, and the description thereof will be omitted. In the drawings referred to, FIG.
[Fig. 6] is a perspective view showing a linear actuator according to a third embodiment.

As shown in FIG. 5, in the linear actuator R ″ according to this embodiment, an inverter 32 connected to each other end of each coil 7 is provided on the lower surface of the mover 2 and adjacent to the inverter 32. The storage battery 34 is integrally provided with a storage battery 34. The storage battery 34 has a structure that can be charged by a charger 35 provided at a predetermined position in the moving path of the mover 2, and has a charging terminal. 34a
Are provided so as to project along the moving direction of the mover 2. Further, the width of the stator 1 ″ is the same as that of the terminal 34a.
Is formed larger than the width of the terminal 34a.
Covers.

The wheel 41 in this embodiment does not need to have conductivity, and is provided to support the mover 2. In addition, for example, if the lower surfaces of the inverter 32 and the storage battery 34 are slid with respect to the fixed base, or if the movable element 2 is supported only by the stator 1, the wheels 41 need not be provided.

Next, the operation of the linear actuator R ″ will be described with reference to FIG. 5. First, when the storage battery 34 is operated by a remote controller (not shown), a direct current is supplied from the storage battery 34 to the inverter 32. The DC current is converted into an AC current by the inverter 32.
When this alternating current is supplied to each coil 7, each excitation block 4 is excited and the mover 2 moves along the stator 1. When the amount of electricity stored in the storage battery 34 decreases due to the operation of the mover 2 for a long time, the mover 2 is moved to the position of the charger 35, and the storage battery 34 is charged by the charger 35.

According to the above, the following effects can be obtained in the third embodiment. (4) Since the coil 7 is energized by the storage battery 34 and the inverter 32 provided in the mover 2, it is not necessary to provide the mover 2 with a cable, and the mover 2 by the cable is used.
The inhibition of the migration of the is prevented. (5) Since the terminal 34a of the storage battery 34 is covered by the stator 1 ″, it is possible to prevent a failure due to water or the like on the terminal 34a without providing a special cover member. For example, the linear actuator R When "" is used for a carrier truck that is used in a factory by fixing the table to the upper surface of the mover 2, even if an operator puts a workpiece with cutting water on the table, cutting that flows down from the workpiece Water can be received by the stator 1 ″. Therefore, it is possible to prevent a failure due to water or the like being applied to the terminals 34a.

As described above, the present invention is not limited to the above embodiment, but can be implemented in various forms. (Iii) In the present embodiment, the core 5 has a structure in which the extending portions 54 and 55 and the facing portions 52 and 53 are integrally formed on the core portion 51 having a substantially U-shaped cross section. The structure is not limited, and the core may be formed by joining the independent core portion, the extended portion, and the facing portion to each other. (Iv) Further, it goes without saying that the number of excitation blocks, cores, etc. can be set arbitrarily. Here, when one exciting block is provided, the linear actuator is used as a vibration actuator, but even in this case, the same effect as that of the present embodiment can be obtained.

(V) In this embodiment, the base portion 51 of the core 5 is
Although the coil 7 is wound around the coil a, the present invention is not limited to this, and the side portions 51b and 51c of the core 5 and the extended portion 5 are not limited to this.
It may be wound around either 4, 55. Furthermore, when the coil 7 is wound around at least two of the side portions 51b and 51c and the extended portions 54 and 55, the effect of stabilizing the magnetic force is obtained. (Vi) The position of the terminal 34a in the third embodiment can be set arbitrarily. For example, by locating the terminal 34a in the vicinity of the stator 1 ″, a failure caused by water or the like being applied to the terminal 34a is more reliable. The shape of the stator 1 ″ can be set arbitrarily. For example, the stator 1 ″ is formed in a substantially U-shaped cross section that opens toward the storage battery 34 side, and the terminal 3 of the rechargeable battery 34 is formed in this U-shaped cross section.
By arranging 4a, it is possible to prevent water or the like from laterally contacting this terminal 34a. Further, by applying the structure for widening the width of the stator to the structures of the first and second embodiments, the rail can be protected from water and the like. That is, by laying the rail within the range where the wide stator is projected onto the installation surface of the rail, the rail is covered with the stator, so that the rail can be protected from water and the like. (Vii) Further, the mover 2 in the third embodiment may be provided with a generator that generates electric power by electromagnetic induction using magnetic flux generated from the stator 1. As this generator, there is, for example, one in which a conductor is arranged in the magnetic field of a stator and a closed circuit is connected to this conductor. That is, in this generator, the conductor moves in the magnetic field of the stator as the mover moves, and a current flows in the closed circuit. By providing such a generator on the mover, the power can be supplementarily charged by the generator even if power is consumed by the movement of the mover.

[0030]

According to the present invention, power is supplied to a movable element that moves when the other end of the coil directly or indirectly contacts a fixedly installed power supply line. The mover can be moved smoothly without the need for installation.

[Brief description of drawings]

FIG. 1 is a perspective view showing a stator and a mover of a linear actuator according to a first embodiment.

FIG. 2 is an enlarged perspective view of an essential part showing the structure of the excitation block of FIG.

FIG. 3 is a perspective view showing a power supply line in the linear actuator of FIG.

FIG. 4 is a perspective view showing a linear actuator according to a second embodiment.

FIG. 5 is a perspective view showing a linear actuator according to a third embodiment.

[Explanation of symbols]

R, R ', R "linear actuator M permanent magnet 1,1 'stator 2 mover 3 power supply lines 31 rails 32 inverter 33 DC power supply 34 storage battery 4 excitation block 5 cores 6 core rows 7 coils 51 core 51a base 51b, 51c First and second side portions 52 upper facing part 53 Lower facing part 54,55 upper and lower extension parts

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kim Hironaka             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Koji Maki             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Isamu Numata             Hitachi 9-2, Aise-cho, Hitachi City, Ibaraki Prefecture             Equipment Engineering Co., Ltd. (72) Inventor Hisao Tadokoro             Hitachi 9-2, Aise-cho, Hitachi City, Ibaraki Prefecture             Equipment Engineering Co., Ltd. (72) Inventor Kenro Morimoto             4-6 Kanda Surugadai, Chiyoda-ku, Tokyo             Within Hitachi, Ltd. (72) Inventor Yasuchi Mito             4-6 Kanda Surugadai, Chiyoda-ku, Tokyo             Within Hitachi, Ltd. (72) Inventor Hiroshi Ueno             Hitachi 9-2, Aise-cho, Hitachi City, Ibaraki Prefecture             Equipment Engineering Co., Ltd. (72) Inventor Hideki Shimane             Hitachi 9-2, Aise-cho, Hitachi City, Ibaraki Prefecture             Equipment Engineering Co., Ltd. F-term (reference) 5H633 BB02 GG03 GG04 GG07 GG17                       GG21 GG26 HH02 HH05 HH13                       JA10                 5H641 BB03 BB06 GG03 GG04 GG06                       GG15 HH02 JA09

Claims (4)

[Claims] 1. A linear actuator having a stator composed of a magnet array piece in which a plurality of permanent magnets are arranged so that magnetic poles are alternately arranged, and a mover movable along the stator. The child is wound around a core in which a pair of facing portions facing each other with the magnet row piece sandwiched therebetween are biased toward the center side of the core, and a plurality of core rows in which the cores are arranged so that the directions of magnetic force lines between the facing portions alternate. A plurality of exciting blocks each including a coil, and the coils respectively provided in the exciting blocks have their one ends joined to each other and their other ends fixedly installed along the moving direction of the mover. A linear actuator characterized by making direct or indirect contact with a supply line. 2. An inverter connected to each of the other ends of the coil is provided on the mover, and a terminal for taking a current into the inverter directly or indirectly contacts the power supply line. The linear actuator according to claim 1, wherein: 3. A linear actuator, wherein the power supply line of the linear actuator according to claim 1 or 2 is installed within a range of an installation surface on which a stator is projected. 4. A linear actuator having a stator composed of a magnet array piece in which a plurality of permanent magnets are arranged so that magnetic poles are alternately arranged, and a mover movable along the stator, The child is wound around a core in which a pair of opposing portions facing each other with the magnet row piece sandwiched therebetween is biased toward the center side of the core, and a plurality of core rows in which the cores are arranged so that the directions of magnetic force lines between the opposing portions alternate. A linear actuator comprising a plurality of excitation blocks each including a coil, an inverter connected to the coil, and a rechargeable storage battery connected to the inverter.