JPH05231068A - Linear motor for opening/closing of door - Google Patents

Abstract

PURPOSE:To enhance accuracy of the stopping position of a door in which magnetic field of a permanent magnet is mounted on its top and that its opening/closing is driven by a travelling magnetic field generated by an armature mounted on the bottom of the upper frame of a door frame. CONSTITUTION:The gap (A) between the projecting magnetic poles of armatures and permanent magnets 11 used as magnetic poles within the width of a door in a specified section in the position of the door that requirs accuracy of its position at the stopping time is made larger than the gap (B) in the remaining section, and cogging force that acts on the door in its moving direction is reduced by constructing the projecting magnetic poles of respective phase armatures in this section with plural small projecting magnetic poles, and coiling small winding round respective small projecting magnetic poles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor for generating a driving force for opening and closing an automatic door which automatically opens and closes when a person approaches.

[0002]

2. Description of the Related Art As a conventional automatic door using a linear synchronous motor (hereinafter abbreviated as LSM) using a permanent magnet as a field, one having a structure shown in FIGS. 10 and 11 is known. Here, FIG. 11 shows a cross section taken along line BB in FIG. The armature 2 including the yoke 22 and the winding wire 21 is attached to the lower surface of the upper frame of the door frame 6, and the field 1 including the yoke 12 and the permanent magnet 11 thereon is attached to the upper surface of the door 3. A linear synchronous motor composed of these armature 2 and field 1 is configured. The permanent magnets 11 are arranged so as to alternately reverse the direction and generate a magnetic flux in the vertical direction, and the pitch thereof is the pole pitch of the armature.
It is 1.5 times. The yoke 12 to which the permanent magnet 11 is attached has an L-shaped cross section, and the L-shaped horizontal surface is the door 3
Is fixed to the upper surface of the vehicle, and the shaft of the wheel 4 of the door 3 is fixed to the vertical plane. Two rails 5 of the wheel 4 are provided above and below with the wheel 4 sandwiched therebetween, the lower rail has a strength to withstand the total weight of the field 1 and the door 3, and the upper rail is between the armature 2 and the rail 5. It is prevented that the magnetic field 1 is attracted together with the door 3 by the acting attractive force and the gap between the permanent magnet 11 of the magnetic field 1 and the convex magnetic pole of the armature winding is reduced, and the two rails keep the gap constant. Retained.

In the SLM of the automatic door constructed as described above, a three-phase alternating current is sequentially supplied to the armature windings 21 arranged in the door moving direction, or the phase order is switched to the left direction in the figure. Alternatively, a traveling magnetic field in the right direction is generated.
When the door 3 moves at a synchronous speed that is the same speed as the traveling magnetic field and the phase of the permanent magnet 11 and the traveling magnetic field is in a constant relationship, a propulsive force that coincides with the traveling direction works, and the wheels 4 and the rails 5 Thus, the synchronous speed of the door 3 described above is maintained by overcoming the drag force such as the frictional resistance. Further, in order to generate an effective propulsive force in the direction in which the door 3 moves, the position of the permanent magnet 11 is detected, and the armature winding 21 is arranged in such a phase that the propulsive force is generated in the predetermined direction at that position. Generally, a method of applying an electric current to is adopted.

[0004]

FIG. 7 shows an enlarged view of the essential parts of FIG. The figure shows a state in which the permanent magnet with the N pole on the upper surface is directly below the U-phase winding of the armature, and the permanent magnet with the S pole on the upper surface is located in the middle of the V-phase and W-phase windings of the armature. ing. In an LSM that uses a permanent magnet for the field, an attractive force acts between the armature yoke having a convex magnetic pole and the field, and this attractive force in the vertical direction changes depending on the horizontal position of the permanent magnet. It consists of component force and component force in the horizontal direction (x direction in the figure). The distribution f in the x direction (hereinafter referred to as the “gogging force”) f changes as shown in FIG. 9 when the center position of the permanent magnet whose upper surface in FIG. 7 is the N pole is the origin of the moving distance in the x direction. As described above, since there are stable positions where the gogging force f becomes zero for every 1/2 of the armature pole pitch, there is a drawback that the stop position accuracy becomes poor at the stop position of the door where the armature current is interrupted. was there.

An object of the present invention is to provide a structure for a door opening / closing SLM in which a gogging force is weakened only at a door position where a stop position accuracy is required, whereby a door opening / closing SLM having a good stop position accuracy can be obtained at low cost. It is to be.

[0006]

In order to solve the above problems, in the present invention, a permanent magnet field is attached to the upper surface of the door, and an armature is provided on the lower surface of the upper frame of the door frame to cover the entire moving range of the door. A linear motor for opening and closing the door that is installed over the door to form a linear synchronous motor, and the gap between the armature convex magnetic pole and the permanent magnet for field magnet within a predetermined range within the door width at the door position that requires positional accuracy when stopped. Is a motor in which the gap between the armature convex magnetic poles and the field permanent magnets outside the predetermined range is larger, or each phase within a predetermined range within the door width at the door position that requires positional accuracy when stopped Each of the armature windings is composed of a plurality of small windings, and each phase armature convex magnetic pole has a center interval smaller than the center interval of each phase armature winding. The same number of small convex magnetic poles A motor said plurality of Komaki lines were wound respectively on the small convex pole.

In a linear motor in which each phase armature winding is composed of a plurality of small windings, one or a plurality of windings extending from the armature yoke is provided between each phase armature winding. It is preferable to form a convex magnetic pole in which is not wound.

[0008]

As described above, the gap between the armature convex magnetic pole and the field permanent magnet within the predetermined range within the door width at the door position where the position accuracy at the time of stop is required is set to the armature convex outside the predetermined range. If the gap is larger than the gap between the magnetic pole and the field permanent magnet, the magnetic flux density passing through the gap between the armature convex magnetic pole and the field permanent magnet becomes small within this range, and the armature yoke including the convex magnetic pole is reduced. The attractive force between the field and the field becomes smaller. As a result, the gogging force across the entire width of the door is reduced, so by expanding the gap within the above range so that the reduced gogging force is less than the friction resistance between the door wheel and the rail, the door is Stop at the moment of current interruption,
The door stop position accuracy can be improved.

Further, each phase armature winding within a predetermined range within the door width at the door position which requires positional accuracy at the time of stop is constituted by a plurality of small windings, and each phase electric machine is The sub-convex magnetic poles are formed of the same number of small convex magnetic poles as the plurality of small windings and have a center distance smaller than the center distance of each phase armature winding. When each is wound, the gogging force generated within the predetermined range becomes smaller, and the size is smaller than the gogging force generated between the armature yoke and the field outside the predetermined range. Therefore, the door stop position accuracy can be improved by setting the gogging force in the entire door width at the door position requiring the stop position accuracy to be equal to or less than the friction resistance between the wheel and the rail.

In the SLM in which each phase armature winding within the predetermined range is composed of a plurality of small windings, one or more extending from the armature yoke is provided between each phase armature winding. By forming a convex magnetic pole with no winding,
The change in the gogging force occurring within this range becomes smoother, and the effect of smoother movement of the door when opening and closing the door is added.

[0011]

1 and 2 show a first embodiment of the present invention. FIG. 1 shows an elevation view of the main part of the linear motor, and FIG. 2 shows a cross-sectional view at the CC position in FIG. In these figures, the same members as those in FIGS. 7, 8, 10 and 11 are designated by the same reference numerals and the description thereof will be omitted. Only in the section I in the door width at the door closed position where the stop position accuracy is required, as compared with the remaining section II, the convex magnetic poles of the armature 2 and the field permanent magnet 11 are compared.
The convex magnetic poles in the section I are formed so that the gap A between them and the gap B is larger than the gap B in the remaining section II.
If the gap is increased, the magnetic flux density passing through the gap is decreased, and the gogging force in the x direction is decreased as shown in FIG. Therefore, by selecting the gap A so that the gogging force in the entire door width is smaller than the frictional resistance between the wheels 4 and the rails 5, the door 3 is stopped when the door is stopped at the position where the stop position accuracy is required. It will not move and the position accuracy will not deteriorate. In addition, since the section I is usually smaller than the length of the door frame 6 by about 1/5,
Even if the loss in the coil increases due to the increase in the number of turns of the armature winding 21 or the flowing current in order to compensate for the decrease in the propulsive force in the x direction due to the increase in the gap A, this loss increase is slight. Therefore, the accuracy of the stop position can be improved without substantially increasing the power consumption.

In this embodiment, the section I is set with the door frame as one end of this section. However, the right end of the door width within the door width at the door position where positional accuracy is required. If set to the side, at the door position where this section is within the door width,
The stop position accuracy becomes high at any position, and the width of the stop position with high position accuracy is expanded. 2 and 3 of the present invention
An example of is shown. In order to reduce the gogging force and improve the stop position accuracy, in this embodiment, each phase armature winding is configured by a plurality of small windings only in the section I in FIG. The armature convex magnetic poles are configured with the same number of small convex magnetic poles as those of the plurality of small windings, having a center distance smaller than the center distance of each phase armature winding. Each wire is wound and a plurality of small windings are connected in series. As a result, the gogging force within the section I becomes smaller as shown in FIG. 6 and the gogging force itself becomes smaller, so that the stop position accuracy of the door 3 can be increased as in the first embodiment. It should be noted that the small convex magnetic poles in which the windings are not wound between the small convex magnetic pole groups of each phase in the section I in FIG. 4 are for smoothing the change of the gogging force depending on the position of the permanent magnet in the x direction. This allows the door 3 to move more smoothly when opening and closing.

[0013]

As described above, in the present invention, the permanent magnet field is attached to the upper surface of the door, and the armature is attached to the lower surface of the upper frame of the door frame over the entire moving range of the door to perform linear synchronization. In a door opening / closing linear motor that constitutes a motor, the gap between the armature convex magnetic pole and the field permanent magnet within a predetermined range within the door width at a door position that requires positional accuracy when stopped is outside the predetermined range. Larger than the gap between the armature convex magnetic pole and the field permanent magnet, or
Each phase armature winding within a predetermined range within the door width at the door position that requires position accuracy at stop is configured with a plurality of small windings, and each phase armature convex magnetic pole is Has a center spacing smaller than the center spacing of each phase armature winding,
It is composed of the same number of small convex magnetic poles as the plurality of small windings, and the plurality of small windings are respectively wound around the plurality of small convex magnetic poles, and acts on the door at the door position where stop position accuracy is required. Since the gogging force to be used is reduced, the door opening / closing linear motor can be inexpensive and has a high door stop position accuracy. Further, since the door is vertically immovably supported by rails sandwiching wheels whose shafts are fixed to the door from above and below, the gap between the once set armature convex magnetic pole and the field permanent magnet does not change. , The stop position accuracy of the door is maintained unchanged.

Further, a linear motor having a plurality of small convex magnetic poles for each phase armature convex magnetic pole within a predetermined range within the door width at a door position requiring positional accuracy when stopped, and a small convex magnetic pole group for each phase In a linear motor that has a non-winding convex pole between each other, the change in the gogging force due to the movement of the field permanent magnet is small, and the effect of smoother door movement when opening and closing the door is added. To be done.

[Brief description of drawings]

FIG. 1 is an elevation view of a main portion of a linear motor showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line CC in FIG.

FIG. 3 is an explanatory diagram showing changes in the gogging force depending on the position in the moving direction of the field permanent magnet of the linear motor according to the embodiment of FIG. 1 for each section of the door width at the door stop position.

FIG. 4 is an elevation view of a main portion of a linear motor showing a second embodiment of the present invention.

5 is a sectional view taken along the line CC in FIG.

FIG. 6 is an explanatory view showing changes in the gogging force depending on the position in the moving direction of the field permanent magnet of the linear motor according to the embodiment of FIG. 4 for each section of the door width at the door stop position.

FIG. 7 is an elevation view of a main part of a conventional linear motor for opening and closing a door.

FIG. 8 is a sectional view taken along the line CC in FIG.

9 is an explanatory diagram showing a change in the gogging force depending on the position in the moving direction of the field permanent magnet of the linear motor shown in FIG.

FIG. 10 is an elevation view of an automatic door using a conventional linear synchronous motor of permanent magnet field.

11 is a sectional view of the automatic door shown in FIG. 10 taken along the line BB.

[Explanation of symbols]

 1 Field 2 Armature 3 Door 11 Permanent Magnet 12 Yoke 21 Winding 21 'Small Winding 22 Yoke A Gap B Gap

Claims (3)

[Claims] 1. A door opening / closing linear motor having a permanent magnet field attached to the upper surface of the door and an armature attached to the lower surface of the upper frame of the door frame over the entire moving range of the door to form a linear synchronous motor. The gap between the armature convex magnetic pole and the field permanent magnet within a predetermined range within the door width at the door position requiring the time positional accuracy is set to the armature convex magnetic pole and the field permanent magnet outside the predetermined range. A linear motor for opening and closing doors, which is characterized by making it larger than the gap. 2. A door opening / closing linear motor which constitutes a linear synchronous motor by mounting a permanent magnet field on the upper surface of the door and mounting an armature on the lower surface of the upper frame of the door frame over the entire moving range of the door. Each phase armature winding within a predetermined range within the door width at the door position that requires time position accuracy is configured by a plurality of small windings, and each phase armature convex magnetic pole is Having a center spacing smaller than the center spacing of the phase armature windings, comprising the same number of small convex magnetic poles as the plurality of small windings, and winding the plurality of small windings on each of the plurality of small convex magnetic poles. A linear motor for opening and closing the door. 3. The door opening / closing linear motor according to claim 2, wherein one or a plurality of armature yokes extending from the armature yoke are provided between the respective phase armature windings each of which is composed of a plurality of small windings. , A door opening / closing linear motor characterized by forming a convex magnetic pole without winding.