JPS60204253A - Magnetic circuit structure of linear pulse motor - Google Patents

Abstract

PURPOSE:To reduce the irregularity of a thrust in a linear pulse motor by winding coils on a pair of cores disposed in parallel, and disposing a pair of permanent magnets perpendicularly to the pair of cores, thereby shortening the size of a slider in the moving direction. CONSTITUTION:A pair of cores 4, 5 are disposed in parallel along the longitudinal or lateral direction of a scale 1, and coils 2, 3 are respectively wound on the cores 4, 5. A pair of permanent magnets 6a, 6b are disposed perpendicularly to the pair of cores 4, 5, and the both ends of the magnets 6a, 6b are mounted at both ends of the pair of cores 4, 5.

Description

[Detailed Description of the Invention] This invention relates to a primary side magnetic flux generator (hereinafter referred to as a slider).
The present invention relates to a magnetic circuit structure for a linear pulse motor that aims to shorten the dimensions in the direction of movement and reduce variations in thrust force.

As is well known, a linear pulse motor operates on a slider or quadratic scale (
The magnetic circuit (hereinafter simply referred to as a scale) is moved in a stepwise manner, and its magnetic circuit has the configuration shown in FIG. In this figure, 1 is a scale composed of a long plate, and its upper surface has uneven teeth.
a, 1a, . . . are formed at equal intervals in the longitudinal direction.

On the upper surface of this scale 1, there is a support structure consisting of rollers, etc., U-shaped cores 4 and 5 around which coils 2 and 3 are wound, and magnetized between the cores 4 and 5 with the polarity shown in the figure. A slider 7 consisting of a permanent magnet 6 is mounted. In this case, the slider 7 is movable in the longitudinal direction of the scale 1 due to the horizontal support structure, and the magnetic poles 4 of the cores 4 and 5 are
Predetermined gaps are formed between the lower surfaces of the teeth a, 4b, and 5a15b and the upper surface of the toothed portion 1a. In addition, the magnetic pole 4a
and 4b and the magnetic poles 5a and 5b are toothed part 1 of scale 1, respectively.
With respect to the pitch of a, cores 4 and 5 are arranged at intervals of 1/2 pitch shifted in phase (rearranged), and cores 4 and 5 are arranged at intervals of 1/4 pitch shifted from each other. By sequentially supplying signals, the magnetic flux generated by the coil 2.3 and the magnetic flux generated by the permanent magnetic flux 6 are distributed to each magnetic pole 4.
a + 4 b + 5 a + 5 b, the magnetically stable position of the slider 7 relative to the scale 1 moves sequentially, and as a result, the slider 7 is adjusted to the scale 1.
move along the longitudinal direction. That is, to explain using the -phase excitation method as an example, ■ When a predetermined current is passed through the coil 2 from the terminals 2a to 2b, the magnetic flux generated by the coil 2 (dotted line A shown in the figure) and the permanent magnet 6 are generated. The magnetic flux (solid line B shown in the figure) is the magnetic pole 4a.
, and cancel each other out at the magnetic pole 4b, so that the position where the magnetic pole 4a and the tooth portion 1a vertically face each other becomes a magnetically stable position.

(2) Similarly, when a predetermined current is passed through the coil 3 from the terminals 3b to 3a, the position where the magnetic pole 5a and the toothed portion 1a are vertically opposed becomes a magnetically stable position.

(2) Similarly, when a predetermined current is passed through the coil 2 from the terminal 2b to the terminal 2a, the position where the magnetic pole 4b and the tooth portion 1a are vertically opposed becomes a magnetically stable position.

(2) Similarly, the position where the meshing magnetic pole 5b, in which a predetermined current is passed through the coil 3 from the terminals 3a to 3b, and the tooth portion 1a vertically face each other becomes a magnetically stable position.

By sequentially repeating the pulse excitation in the order of the above excitation modes ■, ■, ■, ■, the slider 7 moves to the right in the drawing, and also in the order of the excitation modes ■, ■, ■, ■. By sequentially repeating the pulse excitation, the slider 7 moves to the left in the drawing. Note that the slider 7 may be fixed and the scale 1 may be moved.

By the way, the magnetic circuit structure of the conventional linear pulse motor is such that both the magnetic flux generated by the coils 2 and 3 and the magnetic flux generated by the permanent magnet 6 pass through the scale 1 along its longitudinal direction. Therefore, core 4. Permanent magnet 6
(If the permanent magnet 6 is magnetized on the upper surface of the core 4.5, it is a non-magnetic member) and the core 5 must be arranged in parallel in the direction of movement of the slider 7. There was a drawback that the dimensions were long. Furthermore, since the length of the magnetic path from the permanent magnet 6 to the magnetic pole 4 a r 5 b is different from the length of the magnetic path at the magnetic pole 4 b + 5 ai, the magnetic flux passing through the magnetic poles 4 a, 5 b and the magnetic pole 4 b + 5 a However, there was a drawback that the thrust force varied among the excitation modes (1) to (2) described above.

In view of the above-mentioned circumstances, the present invention provides a magnetic circuit structure for a linear pulse motor that aims to shorten the dimensions of the required rider in the moving direction and reduce variations in thrust. a pair of cores arranged parallel to the tile wall along the tile, a coil wound around each of the pair of cores, and a coil arranged perpendicularly to the pair of cores, both ends of which It is characterized by comprising a pair of permanent magnets respectively attached to both ends of the pair of cores.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a magnetic circuit structure including a linear pulse according to an embodiment of the present invention, and parts corresponding to those in FIG. 1 are given the same reference numerals. In this figure, tooth portion 1 a+1 a r... on the top surface of scale 1.
is divided into two parts at the central part of the scale 1 in the horizontal direction, and tooth parts 1 &/ , 1 a/, . . . and tooth parts 1 tL
Z 1 &Z..., and the tooth portion 1a'.

1a', . . . are formed in a manner shifted by 1/4 pitch (C shown in the figure) with respect to the tooth portions 1a'tia'', . The magnetic fields i. of the core 4 are arranged parallel to each other along the longitudinal direction of the core 4.

Each lower surface of pole 4a * 4b is toothed part 1 &'+ 1 a',・
The magnetic poles 5aj of the core 5 are vertically opposed to each upper surface of the core 5.
The lower surfaces of the cores sb are arranged so as to vertically face the upper surfaces of the toothed portions 1a', la'', . . . .
At one end of each of cores 4 and 5, both ends of a permanent magnet 6a are magnetized with the polarity shown in the figure, and at each other end of cores 4 and 5, both ends of a permanent magnet 6b are magnetized in parallel with the permanent magnet 6a. and are magnetized with the same polarity. These 4 pairs, permanent magnets 6a and 6
b are both arranged at right angles to the longitudinal direction of the scale 1. As a result, the magnetic fluxes generated by the coils 2 and 3 pass through the scale 1 along its longitudinal direction as in the conventional case, but the magnetic fluxes generated by the permanent magnets 6a and 5h pass in the direction perpendicular to the longitudinal direction of the scale 1, that is. scale 10
It penetrates along the width direction.

In the above configuration, magnetic poles 4a+4b and 5a.

By sequentially supplying a predetermined pulse signal to the coil 2.3, the slider 7
moves along the longitudinal direction of scale 1 in 1/4 pitch increments.

Next, another embodiment of the present invention will be explained with reference to FIG. 1
a′.

1a', ..., by 1/2 pitch (D shown in the figure). The points are arranged in the longitudinal direction. Thereby, the magnetic flux generated by the coils 2 and 3 warms the scale 1 along its width direction, and the magnetic flux generated by the permanent magnets 6a and 6b penetrates the scale 1 along its longitudinal direction.

According to the embodiment described above, since the cores 4 and 5 are arranged in parallel, the dimension in the moving direction can be shortened compared to the conventional slider 7, and the permanent magnet 6a
to the magnetic poles 4a and 5a, and the length of the magnetic path from the permanent magnet 6 to the magnetic poles 4a and 5a.
The lengths of the magnetic paths from b to the magnetic poles 4b I 5b are all the same, and the magnetic flux of the permanent magnets 6 a + 6 b passing through each magnetic pole 4 a + 4 b + 5 a + 5 b is uniform, so that variations in thrust force are reduced.

In addition, in the embodiment described above, the teeth m on the scale 1
Although the teeth 1a' were formed to be shifted by a predetermined pitch from 1a', these teeth 1a' and 1a' were formed without shifting,
The core 5 may be shifted from the core 4 by a predetermined pitch.

As explained above, according to the present invention, the scales are arranged parallel to each other along the longitudinal direction or the width direction of the scale.
a pair of cores, a coil wound respectively around the pair of cores described in LII, and a coil arranged perpendicularly to the pair of cores described in III, each end being connected to each end of the pair of cores. Since a pair of permanently attached permanent magnets are provided, it is possible to shorten the dimension of the slider in the moving direction and to obtain a ladle point that can reduce variations in thrust force.

[Brief Description of the Drawings] Fig. 1 is a schematic diagram showing the configuration of the magnetic circuit structure of a conventional linear pulse motor, and Fig. 2 is a perspective view showing the configuration of the magnetic circuit structure of a linear pulse motor according to an embodiment of the present invention. 3 are perspective views showing the structure of another embodiment of the present invention. 1...Scale, la', la'...
Teeth al, 2, 3... Coil, 4, 5...
・Core s6&+6b...Permanent magnet, 7...
··Slider. Figure 1 Figure 2

Claims (1)

[Claims] By generating magnetic flux in the gap formed between the primary magnetic flux generator and the elongated secondary scale, the -
In the linear pulse motor that moves the magnetic flux generation position or the secondary scale along the longitudinal direction of the secondary scale, the secondary scale is parallel to each other along the longitudinal direction or 1 direction. a pair of cores, a coil wound around each of the pair of cores, and a coil arranged perpendicularly to the pair of cores, each end of which is connected to each of the pair of cores; A magnetic circuit structure for a linear pulse motor characterized by comprising a pair of permanent magnets attached to each end.