JPS5959063A - Straight pulse motor - Google Patents

Abstract

PURPOSE:To obtain a smoothly moving operation of a pulse motor with less friction by detecting the interval difference between a drive tooth from and a driven tooth form and controlling the current to a coil to move the drive tooth form in a direction for eliminating the difference. CONSTITUTION:The interval differences between drive tooth forms 6, 6' and a driven tooth form 7 are respectively detected by distance sensors 10, 10'. Thus, the displacement of the central position between the form 7 and the forms 6, 6' can be identified, and magnetically attracting force is controlled to drive in a direction for eliminating the interval difference between the forms 6, 6' and the form 7' by altering the intensity of the currents of the opposing coils 5, 5' on the basis of the displacement.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a polarized pulse motor, and more particularly to an improvement of a linear pulse motor based on Sawyer's principle.

(2) Background of the technology The straight-travel Norkulsmoke, which is based on Mr. N'Yar's principle, has a drive tooth profile made of a ferromagnetic material that has multiple teeth wrapped around coils and is magnetically coupled to a permanent magnet. The drive tooth profile is composed of a driven tooth profile made of a ferromagnetic material and has a plurality of teeth facing the drive tooth profile.The drive tooth profile and the driven tooth profile have different spacing between the teeth, and the teeth face each other when the coil is energized. The difference in the magnetic flux density of both O1u of the tooth part of the co-driving tooth profile is used to generate a force that moves relatively between the two tooth parts by the slope of the cloth groove, and fixes one of the tooth profiles. It is configured so that it can be moved in the direction shown in FIG.

In such a linear pulse motor, a magnetic attraction force that attracts both tooth profiles to each other is exerted by the action of the permanent magnet.

This magnetic q attraction force is much larger than the driving force in the direction of movement, and in order to prevent the magnetic pole gap between the two tooth parts from changing due to the magnetic attraction force, the two tooth parts are supported at a distance of 2 by bearings, etc. ing.

Since such a bearing generates frictional resistance in the direction of motion and has a problem of shortening its wear life, there is a demand for a linear pulse motor that has a weakened magnetic attraction force.

(3) Prior art and problems In order to deal with the problem of magnetic attraction force, conventionally, a pair of driving tooth profiles are distributed on both sides of the driven tooth profile.
A linear pulse motor configured to match two tooth-shaped magnetic suction blades is used.

However, even in such double-sided linear pulse motors, if there is a difference in the spacing between the magnetic pole gaps on both sides due to mechanical errors during manufacturing and assembly or shocks and vibrations during operation, the difference between the magnetic poles will be exacerbated. As the force is generated, the bearing will eventually wear out, and as the difference increases, a larger force will act on the bearing link, making it impossible to sufficiently cancel out the increase in time caused by the magnetic attraction force.

(4) Purpose of the Invention The present invention does not take into account the problems of the prior art described above, and provides a double-sided linear pulse motor in which one driving tooth profile is arranged on both sides of the driven tooth profile. An object of the present invention is to provide a linear pulse motor configured to almost eliminate magnetic force and adhesion perpendicular to the moving direction of a driven tooth profile and to float the driven tooth profile between two drive tooth profiles.

(5) In order to achieve the object of the present invention, the attraction force of the ferromagnetic rotor is non-linear with respect to the air gap distance and the applied ampere-turn in a normal barrier pull reluctance type pulse motor. To control the intermediate floating state, the control method based on the air gap distance was difficult to implement, but with a linear pulse motor based on Mr. Sawyer's principle, the adsorption force is linear with respect to the air gap distance within a certain range. A linear control theory based on air gap spacing is applied by focusing on the fact that the air gap becomes closer. Therefore, in the present invention, l pairs of drive tooth profiles made of a ferromagnetic material and magnetically coupled to a permanent magnet and having a plurality of tooth parts around which coils are wound are arranged with their respective front surfaces facing each other. A driven tooth profile made of a ferromagnetic material and having a plurality of teeth facing both tooth profiles is disposed between a pair of driving tooth profiles so as to be movable in the direction of tooth arrangement.
-In the evening.

What is the gap difference between each driving tooth profile and the driven tooth profile? The coil is equipped with a gap measuring means for detecting the gap, and is configured to perform Il[IJ sub-control of the coil according to the output of the gap 1111 determining means. FIG. 2 is a cross-sectional view of a linear pulse motor. A driven tooth profile 7 is arranged between a pair of drive tooth profiles 6,6'. Each driving tooth profile 6.6' has a similar configuration, and tooth profiles 2.3 made of a ferromagnetic material each having two teeth 4 in parallel are magnetically coupled to both sides of the permanent magnet l. Fixed. A coil 5 is wound around each tooth 4. Both coils in each tooth profile 3 constitute a set of coils connected in reverse to each other. The driven tooth profile 7 is made of ferromagnetic material,
It has a plurality of tooth portions 9 facing the double-movement tooth profile 6.6′,
The space between each tooth portion is filled with a non-magnetic material 8. , the distance between the teeth of the driving tooth profile and the distance between the teeth of the driven tooth profile are different, and the magnetic flux density on both sides of the tooth part 9 of the driven tooth profile is at a position where the facing teeth are shifted due to the excitation of the coil. A difference is created between the two teeth, and this gradient generates a force that moves the two tooth portions relative to each other, and the driven tooth profile 7 moves in the direction of the tooth arrangement. Each drive tooth profile 6.6'
are each equipped with an ill sensor 10.10' for measuring the distance between the toothing 4.4' of the respective driving toothing 6.6' and the facing toothing 9 of the driven toothing 7. Distance sensor 1
0.1σ is used, for example, in a type that detects distance by measuring capacitance, or in a type that irradiates light and detects distance 1411'<< based on the intensity of the reflected light.

Such a distance sensor lO,iσ detects the difference in the interval between the surface drive tooth profile 6.6' and the driven tooth profile 7, and the distance between the driven tooth profile 7 and the center position between the surface drive tooth profile 6.6' and the driven tooth profile 7 is detected. Based on this, the strength of the current in the facing coils 5, 5' can be changed to control the drive of the coils so that the magnetic attraction force is applied in a direction that eliminates the difference in the distance. In this way, each drive tooth profile 6. Instead of ff having a separate distance sensor 10.10', an electronic circuit comprising coils Fi, 5'i enables the surface drive tooth profile 6.6' and the cover! lI
A circuit can be formed that automatically controls the current to the coil to sense the inductance of the air gap between the teeth 7 and modify the position of the driven teeth 7 based thereon. An example of such a circuit is shown in FIG.

A bridge circuit is formed by the facing coils 5.5',
A high frequency voltage 11 is applied to this circuit to detect the difference in inductance that varies depending on the air gap, and the current to the coil can be controlled accordingly.

(7) As described in detail, the present invention provides a double-sided linear pulse motor in which driving tooth profiles are arranged on both sides of the driven tooth profile.
Internal shape and covering for both parts! By detecting the interval between the IJ tooth profiles and controlling the current to the coil so that the internal shape of the covered lIJ moves in the direction that eliminates the difference, the covered vJ tooth profile can be changed to the tooth profile for surface drive. It is held floating in the middle of nM, resulting in smooth movement with little friction.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the linear pulse motor according to the present invention, Figure 2 is
The diagram is that drive! FIG. 3 is a circuit diagram of an example of an IJ INJl path. 1... Permanent magnet, 4.4', 9... Teeth, 5.5'... Coil, 6.6'...
・Driving tooth profile, 7... Driven tooth profile, 10.1 (
y... Distance sensor. Patent applicant Fujitsu Ltd. Patent agent Akira Aoki Patent attorney Kazuyuki Nishidate 1) Yukio Patent attorney Akiyuki Deme

Claims (1)

[Claims] ■. A pair of driving tooth profiles made of a ferromagnetic material magnetically coupled to a permanent magnet, with the tooth surfaces facing each other. A linear pulse motor in which a driven tooth profile made of a ferromagnetic material and having a plurality of teeth facing the two tooth profiles is disposed between the l pairs of drive tooth profiles so as to be movable in the tooth arrangement direction. It is equipped with a gap measuring means for detecting the difference in the gap between each of the driving tooth profiles and the driven tooth profile, and in accordance with the output of the gap measuring means, the current of the coil wound around the tooth profile with the wider gap is increased to increase the gap. A linear pulse motor characterized in that it is configured to perform drive control to weaken the current in a coil wound around the narrower tooth profile. 2. In the linear pulse motor according to claim 1, each driving tooth profile is provided with a distance sensor for measuring the distance between the tooth profile and the driven tooth profile, and the gap measuring means is constituted by: 1. A linear pulse motor featuring the following. 3. In the linear pulse motor according to claim 1, the entire bridge circuit is formed by the coils having toothed shapes for opposing both parts, and by applying a sieve frequency %'1 pressure to this circuit, the inductance and the inductance which change due to the air gap are generated. A straight-travel motor, characterized in that the air gap measuring means is constituted by a circuit DI capable of detecting a difference between the two.