JPS5932986B2 - linear motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a linear motor, and particularly to a drive mechanism in a movable magnet type linear motor.

The linear motor includes a linear guide rail, a moving member that can freely move linearly along the guide rail, and a driving means that drives the moving member using electromagnetic force.
Because it has the advantage of generating extremely little vibration, it is used as a moving member to drive the arm of a linear tracking player, for example, by supporting the tone arm so that it can rotate freely in the horizontal and vertical directions. ing.

Further, the linear motor has a driving means that includes a movable element including a magnet fixed to a moving member, and a fixed 5T element including a coil provided over the moving range of the moving member with a predetermined gap between the movable element and the movable element. There is a movable magnet type linear motor with the following configuration.

In a conventional movable magnet type linear motor, a coil is continuously wound around a yoke extending parallel to a guide rail and extending over the movement range of a moving member.

Therefore, when the movable member is driven, the drive current is supplied to the entire coil, and the current flows through the portions of the coil that do not apply force to the magnet, resulting in considerable power loss and being uneconomical.

An object of the present invention is to provide a drive mechanism or a near motor with low power consumption.

In the linear motor according to the present invention, the driving section has a movable element including a pair of magnets fixed to the movable member at a predetermined distance in the moving direction of the movable member, and a movable element that has a predetermined gap between the movable element and the movable element and a predetermined gap in the moving direction. and a stator including a plurality of coils arranged at intervals, and when one of the pair of magnets is located between adjacent coils of the plurality of coils, the other always faces one of the plurality of coils. and configured to supply a drive current only to the coils opposed to the other of the pair of magnets in accordance with the output of the means for detecting the moving position opposed to each of the plurality of coils of the movable element. It is characterized by

Hereinafter, the present invention will be explained in detail with reference to the drawings.

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

In FIG. 1, a pair of linear guide rails 1a and 1
b are provided horizontally and substantially parallel to each other, and a moving member 2 is engaged with the pair of guide rails 1a and 1b so as to be capable of linear movement.

That is, the structure is such that rollers 3 and 4 rotatably attached to the moving member 2 are engaged with guide rails 1a and 1b, respectively.

Furthermore, it is also possible to configure a braking mechanism that can apply appropriate viscous braking to the moving member 2 by filling a braking material such as silicone grease between the roller 3 and its central axis.

Two pairs of magnets 5a, sb and 5c, 5d as movers are additionally attached to the lower end of the moving member 2.

The magnets 5a, 5b, 5c, and 5d face each other with the same magnetic poles (for example, N poles) with a predetermined gap, and the two pairs of magnets 5a, 5b, 5c, and 5d are connected to the moving member 2.
are provided at a predetermined distance in the direction of movement.

In the gaps between the magnets 5a and 5b and between the magnets 5C and 5d, a yoke 6 wound with a plurality of coils T constituting a stator is provided parallel to the guide rails 1a and 1b and over the range of movement of the moving member 2. There is.

The plurality of coils T each have approximately the same coil length and are arranged at a predetermined interval L (distance between the centers of each coil).

Further, the two pairs of magnets 5a, 5b, 5c, and 5d are preferably nI, /2 (n: odd number 9
There is a distance between them.

Magnetic flux generated from the N poles of magnets 5a, 5b, 5c, and 5d interlinks with coil γ.

Therefore, Ma. By supplying a current of a predetermined direction and a predetermined value to the coil γ facing the magnet 5a, 5b or 5c, 5d, a boat force acts between the magnet 5a, 5b or 5c, 5d and the coil T, and this force causes movement. The movable member 2 is driven in a predetermined horizontal direction.

Current supply control to the coil 1 to which this driving current is to be supplied, that is, the coil 1 facing the magnets 5a, sb or 5c, 5d, will be described later.
This is carried out in a control circuit (shown in the second figure) in response to the output of the position detection means for detecting the movement positions of points c and 5d.

On the other hand, the position detecting means for detecting the moving positions of the magnets 5a, 5b, 5c, and 5d are arranged so that the magnets 5a, 5b, 5c, and 5d are positioned near the intermediate position of each coil of the plurality of coils γ. A plurality of photocouplers 8 provided on the side and two pairs of magnets 5a, 5b and 5c, 5 to block light between the photocouplers 8 and the light receiving elements.
Compatible with d? It includes a pair of shielding plates 9a and 9b attached to the moving member 2.

The pair of shielding plates 9a and 9b extend in the moving direction of the movable member 2 by a length of L/2 with respect to the spacing between the photocouplers 8 so as to alternately block the light from the photocouplers 8. .

In such a configuration, for example, the magnet pair 5a.

5b faces the coil γ, and the photocoupler 8 corresponding to this coil 1 is shielded by the shielding plate 9a, so the control circuit 10 supplies a driving current to the coil γ according to the output of the photocoupler 8. do.

This drive current causes the coil γ and the magnet pairs 5a, 5
A force acts between (b) and the moving member 2 is driven by this force.

At this time, since the magnet pairs 5c and 5d are located between adjacent coils and the shielding plate 9b is in a position not shielding the photocoupler 8, no driving force is generated in the magnet pairs 5c and sct.

As the movable member 2 continues to move, the magnet pair 5c
, 5d are opposed to the coil 1, and the shielding plate 9b shields the photocoupler 8 corresponding to the coil γ, whereby a drive current is supplied to the coil 1.

At this time, since the magnet pair 5a and 5b are located between adjacent coils and the shielding plate 9a is in a position not shielding the photocoupler 8, no driving force is generated in the magnet pair 5a and 5b.

In this way, by controlling the current supply to the coil γ facing the magnet pair according to the movement position of the mover, that is, the magnet pairs 5a, 5b, 5c, and 5d, the coil 1 in the region where driving force is required is controlled. Because only the drive current is supplied (this is economical as it consumes less power).

Moreover, as shown in FIG. 3, one of the magnet pairs 5a,
Even if 5b (or 5c, 5d) is located between adjacent coils, the other magnet pair 5c, 5d (father is 5a).

sb) always faces the coil γ (this is the position where the current to the coil is switched in a state where almost the entirety of the other magnet pair 5c, 5d (or 5a, 5b) faces the coil 1, so the moving member A substantially constant driving force always acts on the magnet pair 5a, 5b.
Or, even if 5c and 5d are located between adjacent coils, so-called coking will not occur.

As detailed above, according to the linear motor of the present invention, the driving current is only supplied to the coils in the area where driving force is required when moving the moving member 2, that is, the coils facing the movable element (magnet). Since the movable member 2 can be driven, power consumption is low and it is economical.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of one embodiment of a linear motor according to the present invention, and FIGS. 2 and 3 are diagrams for explaining the operation of FIG. 1. Explanation of symbols of main parts, 1a , 1b... Guide rail, 2... Moving member, 5 a m 5 b
*5 c *5d...Magnet, γ...
...Coil, 8...Photocoupler, 9.9
a, 9b... Shielding plate.

Claims (1)

[Scope of Claims] 1. A linear guide rail, a moving member capable of linear movement along the guide rail, and a pair of magnets fixed to the moving member at a predetermined distance in the moving direction of the moving member. and a stator including a plurality of coils arranged with a predetermined gap in the moving direction and at predetermined intervals in the moving direction; position detection means for detecting the corresponding movement position, and when one of the pair of magnets is located between adjacent coils of the plurality of coils, the other always faces one of the plurality of coils. 1. A linear near motor, characterized in that the other of the pair of magnets supplies a drive current only to the opposing coil in accordance with the output of the position detection means. 2. The position detecting means includes a plurality of photocouplers provided corresponding to the plurality of coils, and a coil in which the pair of magnets are opposed to each other (the pair of magnets are arranged to block the light of the corresponding photocouplers). 2. The linear motor according to claim 1, further comprising a pair of shielding plates correspondingly attached to said moving member.