JPH0819244A - Actuator - Google Patents

Abstract

PURPOSE:To provide an actuator whose sliding part can be attached to another member easily. CONSTITUTION:A linear actuator 10 has a rectangular parallelepiped housing 12, a sliding rod 14 which is relatively displaced in the longitudinal direction of the housing 12 and a plurality of rectangular attaching planes 19 formed on both ends of the sliding rod 14.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an actuator,
More specifically, the present invention relates to an actuator capable of controlling a moving speed in a linear direction and controlling a distance by an alternating current having a U phase, a V phase, and a W phase and having a variable frequency.

[0002]

2. Description of the Related Art In recent years, in the technological development of automatic machines represented by robots, the importance of linear actuators that perform accurate linear movements has been increasingly recognized and realized. In particular, linear actuators for work transfer of assembly robots, which require high-precision positioning accuracy, are being widely used.

As described above, in these linear actuators, not only the accuracy of position accuracy but also reliability, longevity, compactness, uniform operation force, easy conversion in the moving direction, and high bending rigidity. It is required to have various characteristics such as.

In order to meet these demands, various linear actuators have been conventionally proposed. An example thereof is the device disclosed in Japanese Patent Publication No. 56-14883. In this prior art linear actuator,
A linear ball bearing is arranged in the longitudinal direction of the inner circumference of the housing, and a slide rod which is engaged with the bearing and in which the cylinder is incorporated is arranged. The slide rod is slid in the axial direction. A plurality of orifices are provided in the above, and an operating force is applied to the slide rod by hydraulic pressure or air pressure to achieve positional accuracy and smoothness of sliding.

[0005]

However, the linear ball bearing provided in the linear actuator according to the prior art has a function of smoothly sliding the slide rod in the axial direction, and thus the slide rod can be reliably operated. It does not exert the function of braking.

Further, since the linear actuator requires a braking device separately from the linear actuator, there are various inconveniences such as an increase in size of the entire device and a difficulty in economy.

Further, since the position accuracy of the linear actuator is maintained by the operating force related to the hydraulic pressure or the pneumatic pressure, the slide rod cannot be braked when the power source of the braking device related to the hydraulic pressure or the pneumatic pressure is cut off. And especially,
Various difficulties have been pointed out, such as it is difficult to ensure safety when the power supply is momentarily cut off, and there is a possibility of causing a malfunction.

The present invention has been made in order to overcome the above inconvenience, and in an actuator for driving a slide portion by an alternating current, the slide portion is controlled and stopped without separately providing a braking device. It is an object of the present invention to provide an actuator that is capable of easily attaching the slide portion to another member.

[0009]

In order to achieve the above object, the present invention controls the linear moving speed of a slide portion by a frequency variable alternating current having a U phase, a V phase and a W phase. And in the actuator that controls the distance,
The same electromagnetic force generating coil is used to brake and stop the slide portion, maintain the stopped state, the housing has a linear bearing and a cap member, and the housing has a rectangular parallelepiped shape and has an end of the slide portion. The part is characterized by having a plurality of rectangular mounting surfaces.

[0010]

By the same electromagnetic force generating coil, the sliding portion can be braked and stopped, and the stopped state can be maintained. Therefore, it is not necessary to provide a braking device separately from the actuator.

Further, the slide portion is easily attached to another member via a rectangular mounting surface.

[0012]

The preferred embodiments of the actuator according to the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention and is a perspective view of a linear actuator having one slide rod. That is, in FIG. 1, reference numeral 10 indicates a linear actuator, and the linear actuator 1
Reference numeral 0 basically includes a rectangular parallelepiped housing 12 and a slide rod 14 made of a conductor such as aluminum or copper. Further, contacts 16a to 16c for inputting an electric signal are attached to the housing 12 on a terminal block 18. A plurality of rectangular mounting surfaces 19 are formed at both ends of the slide rod 14 in the longitudinal direction.

On the other hand, FIG. 2 shows the linear actuator 1
0 shows a side sectional view of FIG. In FIG. 2, the same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

Therefore, in FIG. 2, reference numerals 20a to 20n are brake shoes made of a magnetic material, and the brake shoes 20a to 20n are respectively springs 2.
The springs 22a to 22n are engaged with one ends of the springs 22a to 22n, and the other ends of the springs 22a to 22n are locked to an iron core 24 made of a magnetic material. Then, the doughnut-shaped coils 26 a to 26 f are embedded in the iron core 24 and are housed in the housing 12.

Next, rectangular cap members 28 are attached to both ends of the housing 12, and ring members 29 are fitted in circular holes defined in the central portion of the cap members 28. The slide rod 14 is fitted into the hole defined by the ring member 29. Here, a linear ball bearing may be arranged in the hole of the ring member 29 into which the slide rod 14 is fitted, if necessary. Although not shown, the donut coils 26a to 26f are connected to the electric signal input contacts 16a to 16c after being connected in a predetermined connection mode described later.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG. In this figure, the brake shoe 20 in this embodiment is shown.
It is understood that is a four-sided structure having a fan-shaped cross section.

The linear actuator according to the embodiment of the present invention is basically constructed as described above. Next, its operation and effect will be described.

As can be easily understood from FIGS. 1 to 3, in the linear actuator 10 according to this embodiment, the slide rod 14 and the housing 12 are slidable with respect to each other. That is, in this embodiment, the housing 1
Whether to fix 2 or the slide rod 14 can be appropriately selected according to the needs of the user. In that case, the other component can be used as a moving body with respect to the fixed component. Is. Here, for convenience of description, it is assumed that the housing 12 is fixed to a fixed body (not shown).

By the way, in the structure shown in FIG. 2 in which the donut coils 26a to 26f are arranged on the inner circumference of the housing 12, electromagnetic force may be applied to the slide rod 14 in order to move the slide rod 14 left and right. This is possible by passing an appropriate alternating current through the donut coils 26a-26f. Therefore, next, the action direction of the electromagnetic force induced by passing an appropriate alternating current through the donut coils 26a to 26f will be considered.

First, the donut type coil 26a shown in FIG.
26 to 26f are connected as shown in FIG. 4a. In the circuit connection diagram of FIG. 4a, reference numerals 40a to 40l are fuses that melt at a predetermined temperature and protect the linear actuator 10 from burning of the coil.
Since these are not the gist of the present invention, they will not be described in detail.

Here, in order to facilitate understanding of the above wiring, the circuit connection diagram is rearranged and arranged as shown in FIG. 4b.
As can be easily understood from the circuit connection diagram of FIG. 4b,
The circuit is equivalent to a Δ connection load in three-phase AC. Thus, as shown in FIG. 4a, the contacts 16a through 1
A symmetrical three-phase AC power supply 36 is connected to 6c. Here, the reference symbol E represents the grounding of the symmetrical three-phase AC power supply 36.

Next, the direction of the magnetic flux interlinking with the slide rod 14 when the current from the symmetrical three-phase AC power source 36 is applied to the donut type coils 26a to 26f, similarly to the first slide rod 14. Direction of generated eddy current and electromagnetic force generated by these magnetic flux and eddy current, so-called
The direction of the Lorentz force will be described.

In the symmetrical three-phase alternating current, if the cycle of the power of any one phase is T, the electromotive force of the other phase has the same waveform and is temporally T
The same process is repeated with a delay of / 3, 2T / 3. Therefore, now, assuming that T = 3t ₁ , the times t ₁ , 2t ₁ ,
The direction of the magnetic field generated by the doughnut-shaped coils 26a to 26f at 3t ₁ can be macroscopically represented by the direction of the magnetic force lines drawn on the upper side of FIG. 4a. In the direction diagram of the magnetic field drawn on the upper side of FIG. 4A, the symbol S represents the south pole of the magnet and the symbol N represents the north pole of the magnet. The arrow drawn between the S pole and the N pole indicates the direction of the magnetic force line.

At this time, first, the magnetic poles forming the magnetic lines of force appear on the iron core 24, so that the brake shoes 20a to 20n and the like made of the magnetic material are attracted to the iron core 24 by the magnetic poles. By this suction action, the brake shoes 20a to 20n and the like are separated from the slide rod 14, so that the slide rod 14 can slide.

On the other hand, as easily understood from the direction of the magnetic field lines drawn on the upper side of FIG.
4, the eddy current is generated in the slide rod 14 in a substantially spiral shape. In this case, the slide rod 14 receives an electromagnetic force in the axial direction, and as a result, performs a linear movement in the axial direction. In addition, the moving direction of the slide rod 14, the moving speed,
The movement distance and the like can be easily controlled by preparing a three-phase power reversing switch and a power supply device with variable voltage and frequency.
When the power is not supplied, the brake shoe 20a is pressed by the spring 22a and the slide rod 1
Brake 4

FIG. 5 is a sectional view of a linear actuator according to another embodiment of the present invention, in which reference numeral 52 is a moving member made of a magnetic material, and the Kumadori coil 50 is embedded in the moving member 52. At the same time, the spring 22 makes contact with the iron core 24.

Therefore, when not energized, the repulsive force of the spring 22 causes the moving member 52 to move in the direction of arrow A while sliding on the ball bearings 58a and 58b. Then, the roller member 54 slidably arranged on the brake shoe 56.
When the projection member 28c of the cap member 28c contacts, the roller member 54 moves from the moving member 52 to the slide rod 14
A normal force is applied to the brake shoe 56 and the brake shoe 56 abuts on the slide rod 14 due to the pressure in the normal direction. As a result, the slide rod 14 is braked by the frictional force.

When energized, the moving member 52 receives a force attracted by the iron core 24, and at this time, the slide rod 14 becomes slidable.

[0030]

As described above, according to the present invention, the sliding portion can be braked by the same electromagnetic force generating coil. Therefore, it is not necessary to provide a braking device separately from the actuator, which suppresses the manufacturing cost and reduces the size and size.
The weight can be reduced.

Further, the rectangular mounting surface allows the slide portion to be easily attached to another member.

[Brief description of drawings]

FIG. 1 is a perspective view of a linear actuator according to an embodiment of the present invention.

FIG. 2 is a side sectional view of the near actuator shown in FIG.

3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a schematic electric circuit diagram for driving a linear actuator.

FIG. 5 is a vertical sectional view of another embodiment of the linear actuator.

[Explanation of symbols]

10 ... Linear actuator 12 ... Housing 14 ... Slide rod 16a-16c ...
Contact points 20 ... Brake shoes 22a-22n ...
Spring 24 ... Iron core 26a-26f ...
Coil 36 ... Symmetrical three-phase AC power supply

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[Procedure amendment]

[Submission date] June 28, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

In order to achieve the above object, the present invention controls the linear moving speed of a slide portion by a frequency variable alternating current having a U phase, a V phase and a W phase. And in the actuator that controls the distance,
With operating a current to electromagnetic force generating coil the braking and stopping of the slide portion, holding the stopped state,
The housing has a linear bearing and a cap member, and further, the housing has a rectangular parallelepiped shape, and has a plurality of rectangular mounting surfaces at an end of the slide portion.

Claims (1)

[Claims] 1. An actuator for controlling a moving speed of a slide portion in a linear direction by a frequency-variable alternating current having a U-phase, a V-phase and a W-phase and for controlling a distance, wherein the slide portion is formed by the same electromagnetic force generating coil While holding and holding the stopped state, the housing has a linear bearing and a cap member, and the housing has a rectangular parallelepiped shape, and a plurality of rectangular attachments are attached to the end of the slide portion. An actuator having a surface.