JPS635984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a moving coil type actuator that can move in two axes using one linear motor.

Conventionally, this type of device had a structure in which one coil was wound on one bobbin, so it had only one axis in the transfer direction. Therefore, in order to enable two-axis transfer, it is necessary to combine two magnetic circuits and two moving coil actuators, and one actuator is separated from the other actuator, a relatively heavy yoke, a permanent magnet, etc. This required an output capable of driving the magnetic circuit consisting of the magnetic circuit, which not only made the structure complex, but also had many drawbacks in terms of motion efficiency.

The present invention is characterized in that two coils are wound on one bobbin, and its purpose is to obtain high motion efficiency with a simple structure and to enable biaxial transfer.

According to the present invention, the movable directions in two axial directions are
-Y axis and the direction perpendicular to the X-Y axis is Z
an inner yoke having a long axis in the Y-axis direction and arranged parallel to the Y-axis, and a small gap in the Z-axis direction and a large gap in the X-axis direction with respect to the inner yoke; A bobbin is arranged to surround the inner yoke, and a Y is formed on the outer periphery of the bobbin.
a Y-axis feed coil wound around an axis; an X-axis feed coil wound orthogonally to the Y-axis feed coil in a region where the Y-axis feed coil is parallel to the X-axis on the bobbin; two outer yokes having long axes in the axial direction, parallel to the Y-axis, and arranged so that the X-axis sending coil and the Y-axis sending coil are sandwiched between the inner yokes; A two-axis transfer type linear motor is obtained, which is comprised of two permanent magnets that are attached to the inner yoke between them and have a magnetic field in the Z-axis direction.

The two-axis transfer type linear motor according to the present invention will be explained below with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of the present invention.
The orthogonal coordinates of the dimensions, X, Y, and Z axes, are determined as shown in the figure. However, the transport directions are the X and Y axes.

In FIG. 1, the inner yoke 1 has a long axis in the Y-axis direction, is parallel to the Y-axis, and is widened at both ends to facilitate the construction of a magnetic circuit, and is made of metal with a high saturation magnetic flux density.

The bobbin 2 is constructed around the inner yoke 1 as shown in FIG. 1, and has a small gap with the inner yoke 1 in the Z-axis direction, and an
They are arranged so as to surround the inner yoke 1 with a relatively large gap having a length corresponding to the axial transfer distance.

The Y-axis feed coil 3 drives in the Y-axis direction and
Axial feed coils 4a and 4b perform drive in the X-axis direction.

FIG. 2 is a diagram showing how the X-axis sending coils 4a, 4b and the Y-axis sending coil 3 are wound. As shown in FIG. 2, the Y-axis feed coil 3 is wound around the outer periphery of the bobbin 2 with the Y-axis as the center.

The X-axis feed coils 4a and 4b are the Y-axis feed coil 3
is wound perpendicularly to the Y-axis feeding coil 3 in a region parallel to the X-axis on the outer periphery of the bobbin 2. In other words, it is wound parallel to the X-axis at the end of the bobbin 2 in the Y-axis direction. In the central part of the direction, it is wound parallel to the Y axis. In this case, the X-axis feed coils 4a and 4b wound around the ends of the bobbin 2 in the Y-axis direction become overcrowded, so the X-axis feed coils 4a and 4b are shown in FIG. As shown, it is wrapped in two parts.

In FIG. 1, the outer yokes 5a and 5b each have their long axes in the Y-axis direction, and are attached to both sides of the inner yoke 1 via spacers 6 made of a non-magnetic material so as to maintain a distance parallel to the inner yoke 1. .

The permanent magnets 7a and 7b are attached to the outer yokes 5a and 5b, respectively, and the inner yoke 1 and the permanent magnets 7a and 7b move around the X-axis feed coils 4a and 4b, the Y-axis feed coil 3, and the bobbin 2 so that they can move. The permanent magnet 6
A magnetic circuit is constituted by the inner yoke 1 and the outer yokes 5a and 5b.

FIG. 3 is a sectional view showing the flow of magnetic flux inside the magnetic circuit.

In FIG. 3, the magnetic flux emitted from the permanent magnet 7a is directed to the coil 4 as shown by arrow B indicating the flow of magnetic flux.
a, the coil 3, and the bobbin 2 to reach the inner yoke 1. The magnetic flux within the inner yoke 1 passes through the inner yoke 1, toward the end face of the inner yoke 1, and enters the outer yoke 5a. The magnetic flux that has entered the outer yoke 5a passes through the outer yoke 5a and reaches the permanent magnet 7a, forming one magnetic circuit.

Similarly, a total of four magnetic circuits are constructed as indicated by arrows C, D, and E indicating the flow of magnetic flux. Therefore, a uniform magnetic flux perpendicularly passes through the coils 4a, 4b and the coil 3 from the permanent magnets 7a, 7b toward the inner yoke 1.

FIG. 4 is a diagram for explaining the operation of the two-axis transfer type linear motor according to the present invention, and is a plan view of FIG. 2 viewed from the direction of arrow A. In FIG. 4, the magnetic flux is directed from top to bottom perpendicular to the plane of the paper. In order to obtain movement in the X-axis direction, if you apply current to the coils 4a and 4b from bottom to top toward the plane of the paper in the part where the coils 4a and 4b are perpendicular to the coil 3, they will operate according to Fleming's left-hand rule. The coils 4a, 4 can be driven in the direction of the arrow F indicating the direction.
If a current is passed through b from top to bottom toward the plane of the paper, it can be driven in the direction of arrow G.

Therefore, by movement in the direction of arrow F or G, movement in the X axis can be obtained. To move in the Y-axis direction, if you apply current 3 to coil 3 from left to right toward the page, you can drive it in the direction of arrow H according to Fleming's left-hand rule, and similarly, by applying current 3 to coil 3 toward the page If it flows from right to left, it can be driven in the direction of arrow I. Therefore, movement in the direction of arrow H or I can provide movement in the Y axis. However, in this case, the range in which the two axes can be moved is within a region where magnetic flux does not act on the portion where the coil 4a or 4b is wound on the bobbin 2 in parallel to the X-axis when moving in the Y-axis direction. Further, in the movement in the X-axis direction, the inner yoke 1 and the bobbin 2 shown in FIG. 1 are within a region where they do not interfere.

As described above, since the two-axis transfer linear motor according to the present invention has two coils wound perpendicularly to each other around one bobbin, it is possible to obtain two-axis movement with a simple structure, and the motion efficiency of each axis is also improved. Since it can be applied evenly, it can be applied as a drive device for highly accurate two-dimensional positioning, etc., and exhibits excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a cross-sectional view showing how to wind a coil, Figure 3 is a cross-sectional view showing the flow of magnetic flux inside the magnetic circuit, and Figure 4 is a diagram for explaining the method of driving a two-axis transfer type linear motor according to the present invention. be. 1...Inner yoke, 2...Bobbin, 3, 4a,
4b...Coil, 5a, 5b...Outer yoke, 6
...Spacer, 7a, 7b...Permanent magnet, A...
Arrows indicating the viewing direction; B, C, D, E...Arrows indicating the direction in which the magnetic field flows; F, G, H, I...Arrows indicating the operating direction; X, Y, Z...Coordinate axes. Area K
...A region where the Y-axis feed coil is parallel to the X-axis on the bobbin.

Claims (1)

[Claims] 1 When the movable directions of the two axes are respectively the X-Y axes and the direction perpendicular to the X-Y axes is the Z-axis, then the Y
An inner yoke having a long axis in the axial direction and arranged parallel to the Y axis, and a small gap in the Z axis direction with respect to the inner yoke and a large gap in the X axis direction surrounding the inner yoke. A Y-axis feeding coil is wound around the Y-axis on the outer periphery of the bobbin, and a Y-axis feeding coil is wound parallel to the X-axis at the end of the bobbin in the Y-axis direction and the
An X-axis feed coil wound parallel to the axis, and a long axis in the Y-axis direction, parallel to the Y-axis, and arranged so as to sandwich the X-axis feed coil and the Y-axis feed coil between inner yokes. A two-axis transfer type linear motor comprising two outer yokes, and two permanent magnets that are attached to the inner yoke between the inner yoke and the outer yoke and have a magnetic field in the Z-axis direction. .