JPS6295959A - Linear motor - Google Patents

Abstract

PURPOSE:To reduce the abrasion of a guide means, lighten the weight of the titled device, and reduce its cost, by arranging coils in the direction crossing the field magnetic flux of a magnetic circuit, and by eliminating a magnetic suction force between a stator and a mover. CONSTITUTION:A linear motor is organized with a stator 1 extended linearly and fixed on the central section of a base 2, a guide means 5 consisting of guide bars 3 set at both ends of the base 2 and rollers 4 mounted on the bars 3, and a mover 6. The stator 1 is organized with a plurality of flattened air-core coils 7 arranged in a line in adjacent contact with each other, and the coil bearing units 8a, 8b of non-magnetic substance, and is provided with a hole element 9 for detecting the position of the mover 6. Beside, the mover 6 is organized with 'square'-formed yoke bearing units 12, permanent magnets 13, and the like. Then, the widths of the coils 7 are made larger than the widths of the permanent magnets 13, and coil bearing sections 8 are arranged outside the space between the upper and lower permanent magnets 13, and so a great thrust can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a linear motor, and particularly to the configuration of a stator and a movable element.

[Prior art]

Figures 23 and 24 are from Japanese Patent Application Laid-Open No. 58-63074.
1 is a sectional view of the linear motor described in the publication, viewed from the side and a sectional view viewed from the front.

This linear motor has a stator 101 extending in a predetermined direction.
, a movable element 102 that moves along the longitudinal direction of the stator 101, and a guide means 103 (see FIG. 24) that guides the movement of the movable element 102.

The stator 101 includes a rectangular yoke plate 104, and a predetermined conductive pattern (not shown) arranged on the upper and lower surfaces of the rectangular yoke plate 104.
a printed circuit board 105 having a
5 and a large number of air-core coils 106 arranged along the longitudinal direction of the yoke plate 104. As shown in FIG. 24, grooves are formed on both sides of the yoke plate 104 over the entire length of the movement area of the movable element 102.
07 is formed. In addition, the upper printed circuit board 105
Above, inside each coil 106, a position detection element 108 of the movable element 102 is attached.

On the other hand, as shown in FIG. 24, the movable element 102 includes a yoke member 109 having a mouth-shaped front cross-sectional shape and a predetermined length, and permanent magnets located above and below the inside of the yoke member 109. 110 is attached. As shown in FIG. 24, a plurality of magnets 110 are arranged along the longitudinal direction of the stator 101.

As shown in FIG. 24, the groove 107 of the yoke plate 104
A vertical portion 109a of the yoke member 109 is movably inserted into the yoke member 109. Both ends of the yoke plate 104 protrude outward from the mover 102, and the ends are held between the fixed members 111.
Fixed. Vertical portion 1 in yoke member 109
A pair of upper and lower rollers 112 are respectively protruded from both outer sides of the yoke plate 09a, and the protruding portion of the yoke plate 104 is held between the rollers 112 from above and below. The protruding portion of this yoke plate 104 and the plurality of rollers 11
2 constitutes the guide means 103, and the gap between the coil 106 and the magnet 110 is maintained by the roller 112 coming into contact with the yoke plate 104.

By sequentially switching the energization to the coil 106 according to the facing state of the coil 106 and the magnet 110, the mover 10
2 moves in a desired direction along the longitudinal direction of the stator 101.

By the way, in this conventional linear motor, a yoke plate 104 is provided on the stator 101 side, and a yoke member 109 and a magnet 110 are provided on the movable element 102 side.
Since a magnetic circuit is formed by these yoke plate 104, yoke member 109, and magnet 110, the stator 10
A magnetic attraction force is generated between the movable element 1 and the movable element 102.

This suction force ultimately becomes a pressing force of the roller 112 against the protruding portion of the yoke plate 104, so for example, the shafts and bearings of the yoke plate 104 and the roller 112 should be designed to sufficiently withstand the pressing force for a long period of time. Therefore, the linear motor becomes heavier and costs increase. In addition, the above-mentioned pressing force causes severe wear on the yoke plate 104 and the rollers 112, which shortens the useful life of the guide means, and generates a large amount of abrasion powder, which causes problems.

〔the purpose〕

The purpose of the present invention is to overcome the drawbacks of the prior art described above, and
The objective is to provide a linear motor that is lightweight, inexpensive, and has little wear.

〔composition〕

In order to achieve the above object, the present invention includes a stator extending in a predetermined direction, a movable element that moves along the longitudinal direction of the stator, and a guide means that guides the movement of the movable element. There is.

The stator includes a coil support made of a non-magnetic material made of synthetic resin, for example, extending in the longitudinal direction of the stator;
It is composed of a plurality of coils arranged and supported at predetermined intervals along the longitudinal direction of the coil support. Further, the movable element is a yoke extending in the longitudinal direction of the coil support.

It is composed of a plurality of magnets attached to the inner surface of the yoke along the longitudinal direction of the yoke, and a magnetic circuit is formed by the yoke and the magnets.

At least the coil of the movable element is arranged in a direction interlinking with the field magnetic flux formed by the magnetic circuit.

Next, embodiments of the present invention will be described with reference to the drawings. 1st
2 and 2 are a plan view and a side view of the linear motor according to the embodiment, FIG. 3 is an enlarged sectional view of the linear motor seen from the front, and FIG. 4 is a perspective view of a stator used in the linear motor. It is a diagram.

The linear motor consists of a stator 1 that extends linearly and is fixed at the center of a base 2, a guide bar 3 installed at both ends of the base 2, and a roller 4 placed on the guide bar 3. The movable member 6 is mainly composed of a guide means 5 which is shaped like a guide member 5, and a movable member 6 that moves along the longitudinal direction of the stator 1. Next, stator 1
, the configuration of each member of the guide means 5 and the movable element 6 will be explained.

The stator 1 includes a plurality of flat air-core coils 7 arranged in a line so as to be adjacent to each other, and a coil support 8a made of a non-magnetic material such as phenol resin.

8b. One coil support 8a has an L-shaped cross section, and as shown in FIGS. 3 and 4, both ends of each coil 7 are placed on the stepped portion of the coil support 8a, and the other coil The coil 7 is fixed by being pressed from above by the support 8b and pinching both ends of the coil 7.

Fig. 5 is a wiring diagram of the coil 7. As shown in the figure, 12 coils 7 are arranged in a straight line, and 4 coils 7 are connected in series at every second, making up one phase. U phase,
This is a 3-phase star-connected system consisting of phase (2) and phase W.

As shown in FIGS. 3 and 5, there is a hole below the coil 7 for detecting the position of the movable element 6, in other words, for switching the energization to the coil 7 according to the traveling position of the movable element 6. An element 9 is attached corresponding to each coil 7. On the other hand, a position detection magnet 10 is supported on the lower surface of the movable element 6 so as to face the Hall element 9 . Further, as shown in FIG. 3, a linear potentiometer 11 for controlling the speed of the movable element 6 is installed between the base 2 and the movable element 6.

Next, the configuration of the guide means 5 will be explained. As shown in FIG. 3, the two guide bars 3 mounted on the base 2 both have a circular cross-sectional shape. As shown in FIG. 1, three rollers 4 project horizontally from both sides of the movable element 6, and two of the rollers 4 have triangular grooves on their curved surfaces, allowing them to move. This prevents the child 6 from shifting in the horizontal direction.

As shown in FIG. 3, the movable element 6 includes a yoke support 12 having a mouth-shaped front view, and a rectangular yoke 1 attached to the lower and upper surfaces of the inside of the yoke support 12, respectively.
3, and a permanent magnet 13 supported by the yoke 13 and made of, for example, a rare earth plastic magnet.

FIG. 6 is an explanatory diagram showing the arrangement of the yoke 12 and the permanent magnet 13, as well as the magnetic circuit. As shown in the same figure,
Four permanent magnets 13 are supported on each of the lower yokes 12 so that their different polarities face each other, and the upper and lower yokes 12 and the upper and lower permanent magnets 13 create a field magnetic flux as shown by the broken line. 15 is formed.

As shown in FIG. 3, the width of the coil 7 is designed to be longer than the width of the permanent magnet 13, and both ends of the coil 7 are supported by the coil support 8 as described above.

The center portion of the coil 7 is inserted into the gap between the upper and lower permanent magnets 13, and the coil support 8 is arranged outside the gap between the upper and lower permanent magnets 13. If the configuration is such that only the coil 7 is inserted into the gap between the upper and lower permanent magnets 13, the gap between the upper and lower permanent magnets 13 can be made as narrow as possible, and therefore a large thrust can be obtained. It will be done.

FIG. 7 is an explanatory diagram showing the positional relationship between 7 rows of coils and 13 rows of permanent magnets. Pitch CP of coil 7 and permanent magnet 1
In the case of n-phase connection, between the pitch Mp of 3 and
There is a relationship p = (n + 1) x M p.

It is necessary to energize each phase of the coil 7 in an appropriate direction depending on the position of the movable element 6, and a Hall element 9 is installed to detect the position of the movable element 6. To achieve this, a gap Mb is provided between the permanent magnets 13 arranged as shown in the figure. This gap M
When b is 5m phase excitation (m≦n), Mp: (Mp
Mb)=n: determined by m. Moreover, the vertical field magnetic flux formed by the permanent magnet 13 can be effectively used by this gap MP. Furthermore, the field magnetic flux in the vertical direction changes continuously and almost linearly at adjacent boundary points, and becomes zero at the boundary points, so it can be detected by the Hall element 9 and used as a position signal. .

FIG. 8 is an excitation circuit diagram of the coil 7. In the figure, 16 is the linear motor body, and 17 is the waveform shaping circuit.

18 is an inverting circuit, and 19 is an analog multiplexer.

20 is a direction designation circuit, and 21 is an amplification degree designation circuit.

22 is an automatic gain control circuit, and 23 is a current amplification circuit.

As can be seen from this figure, it has a relatively simple circuit configuration that shapes and amplifies the output of the Hall element 9.

9 to 20 are diagrams showing various modifications of the movable element 6. FIG.

FIG. 9 and FIG. 10 are a sectional view as seen from the side and a sectional view as seen from the front, showing the first modification. In this example, the front shape of the yoke 12 is in the shape of an opening.
Permanent magnets 13 are attached in pairs on the top and bottom of the inner surface.

FIG. 11 and FIG. 12 are a sectional view as seen from the side and a sectional view as seen from the front, showing a second modification, and are they different from the first modification. Point ° is a point where the permanent magnet 13 is attached only to the upper side of the inner surface of the yoke 12.

FIGS. 13 and 14 are a sectional view seen from the side and a sectional view seen from the front, showing a third modification. The difference from the first modification is that the upper and lower yokes 12 are connected. The two side plates 24 are made of a non-magnetic material such as synthetic resin.

FIG. 15 and FIG. 16 are sectional views seen from the side and front showing the fourth modification, and the only difference from the third modification is that the upper yoke 12 has a permanent magnet. This is the point where 13 was attached.

FIG. 17 and FIG. 18 are a side view and a cross-sectional view seen from the front showing the fifth modification, and the difference from the first modification is that the front shape of the yoke 12 is U-shaped. It is a point.

19 and 20 are cross-sectional views of the sixth modification as seen from the side and front. The difference from the fifth modification is that the permanent magnet 13 is attached only to the upper side of the yoke 12. The point is that

FIG. 21 is a perspective view showing a first modified example of the stator 1. In the case of this modification, a plurality of M portions are provided on the side edges of a coil support 8 made of a non-magnetic material such as phenol resin, corresponding to the coil pitch, and the coil 7 is positioned by the U portions. The stator 1 is formed by winding.

FIG. 22 is a perspective view showing a second modification of the stator 1. In the case of this modification, both ends of each of the plurality of linearly arranged coils 7 are supported and fixed by an insert mold of a coil support 8 made of synthetic resin such as polyamide resin to form the stator 1. There is.

In this modification as well, the central portion of the coil 7 is inserted into the field magnetic flux formed by the yoke 12 and the permanent magnet 13, as in the embodiment shown in FIG.

By arranging the coil support 8 outside the field magnetic flux, it is possible to narrow the air gap in the magnetic circuit as much as possible and obtain a large thrust.

〔effect〕

This is because the present invention has the configuration described above.

Since no magnetic attractive force is generated between the stator and the mover, the mechanical strength of the guide means, such as the guide bar or the shaft of the roller, is smaller than that of conventional guide means, resulting in a reduction in weight and cost. It is possible to reduce the Further, wear of the rolling contact portion of the guide means, for example, is reduced.

Therefore, even after long-term use, the amount of wear particles generated is small.
It has the advantage of eliminating problems caused by wear particles.

[Brief explanation of drawings]

1st rI! 1 and 2 are a plan view and a side view of a linear motor according to an embodiment of the present invention, FIG. 3 is an enlarged sectional view of the linear motor seen from the front, and FIG. 4 is a stator used in the linear motor. Fig. 5 is a wiring diagram of the stator coil, Fig. 6 is an explanatory diagram showing the arrangement of the yoke and permanent magnets as well as the magnetic circuit, and Fig. 7 shows the positional relationship between the coil row and the permanent magnet row. 8 is a coil excitation circuit diagram, FIGS. 9 and 10 are side sectional views and front sectional views showing the first modification of the mover, and FIGS. 11 and 10 are explanatory diagrams. FIG. 12 is a cross-sectional view of a second modification of the mover seen from the side and a cross-sectional view seen from the front, and FIGS. 13 and 14 are cross-sections of the third modification of the mover seen from the side. 15 and 16 are a sectional view seen from the side and a sectional view seen from the front, showing a fourth modification of the movable element. 17 and 18 are a side view and a front sectional view showing a fifth modification of the mover, and FIGS. 19 and 20 are a side view and a front view showing a sixth modification of the mover. 21 is a perspective view showing a first modified example of the stator, FIG. 22 is a perspective view showing a second modified example of the stator, and FIGS. 23 and 24 are conventional 1 is a sectional view of the proposed linear motor as seen from the side and a sectional view as seen from the front. 1... Stator, 3... Guide bar, 4
...Roller, 5...Guide means, 6...
...Mover, 7...Coil, 8...Coil support, 13...Yoke, 14...Permanent magnet, 15...Field magnetic flux. Sai 1 figure sai 2 eyes 73 eyes 5 eyes o 6 figures t'7 eyes l? Sai q Mouth Sai 10 years old 11 years old 12th review 15th year old 161EI years old
17th 2 l8EI'71
9 Figure Length 20 i years old 2E
Ill bu 24 times

Claims (2)

[Claims] (1) A linear motor comprising a stator extending in a predetermined direction, a movable element that moves along the longitudinal direction of the stator, and a guide means that guides the movement of the movable element, wherein the stator is , a coil support made of a non-magnetic material extending in the longitudinal direction of the stator, and a plurality of coils arranged at predetermined intervals along the longitudinal direction of the coil support, the movable element comprising: It consists of a yoke extending in the longitudinal direction of the coil support, and a plurality of magnets attached to the inner surface of the yoke along the longitudinal direction of the yoke, and a magnetic circuit is constituted by the yoke and the magnets. A linear motor characterized in that a coil of a mover is arranged in a direction interlinking with a field magnetic flux formed by a magnetic circuit thereof. (2) In claim (1), only the end portions of the coil are supported by the coil support, and the center portion of the coil is disposed in a formed field magnetic flux, and the coil support A linear motor characterized in that its body is placed outside the field magnetic flux.