JPH0360357A - Low inductance actuator - Google Patents

Abstract

PURPOSE:To reduce the inductance of a coil by a method wherein a compensating winding is provided in an actuator and the compensating winding is connected to an armature winding in series. CONSTITUTION:An armature winding 1 is moved reciprocally to the directions shown by arrows 5 and 6 in the figure by a flux obtained by a magnetic circuit composed of a magnet 3 and yoke 4 and a current applied to the armature winding 1. At that time, the directions of the currents applied to the armature winding 1 and a compensating winding 2 are opposite to each other as shown by arrows 7 and 8 in the figure and the windings 1 and 2 are connected to each other with lead wires 11 in series so as to have the directions of induced voltages produced by mutual inductances 9 and 10 as shown by reference numerals 12 and 13 in the figure, so that the induced voltage produced by the armature current is cancelled by the induced voltage produced by the compensating current. With this constitution, the inductance of the coil can be reduced and, when a current is applied to the armature winding, the induced voltage is small. Therefore, a high voltage source is not necessary and the current rising time of the armature winding can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to actuators such as rotating machines and linear motors.

[Conventional technology] OA4! Many small motors are used in 'i3 and FA equipment, but these motors are rarely used alone, and are often used in connection with a control circuit. When the motor is controlled and used in this manner, a high voltage is required due to the inductance of the armature coil of the motor, and current responsiveness is also reduced. In particular, when a closed magnetic circuit core passes through the electric machine f coil, the inductance of the armature coil becomes quite large, which has a large influence on control.

Furthermore, when the inductance of the armature coil is large, the magnetic field generated by the armature coil current also becomes large, which also affects the magnetic circuit.

Methods for reducing the inductance of the armature coil include a method of compensating the inductance of the armature coil using a control circuit, a method of reducing the inductance by optimizing the magnetic circuit, and a short ring method. There are limits to compensation methods using control circuits and methods using optimization of magnetic circuits. Currently, the method that is relatively easily used is the short ring method, but in the case of the responsiveness of the armature coil current, the rise characteristics of the armature current are compromised, but the time required to reach a steady value is There are problems such as the length of the

From the above, the methods of reducing inductance of armature coils currently used are not sufficient.

[Problem to be solved by the invention] This invention was made to solve the above problems, and by providing a compensation coil in the actuator,
The present invention provides an actuator with reduced inductance of an armature coil.

[Means for Solving the Problems] The present invention provides an actuator that is driven by a current flowing through an armature coil. This actuator is characterized in that the inductance of the armature coil is reduced by providing a compensation coil that is connected in series with the child coil and cancels the magnetic flux generated by the armature coil. Here, the actuator refers to a general rotating motor, linear motor or near motor, or one that repeatedly moves, and may also be a device that primarily generates force or rotational force.

When a current flows through the armature coil of the actuator, an induced voltage is generated due to the armature coil's self-inductance, and current responsiveness etc. are reduced. Therefore, in order to reduce the self-inductance L of the 7E armature coil, a compensation coil is provided in series with the armature coil, and the armature coil and the compensation coil are arranged so that they cancel each other's magnetic flux. Reduce the overall inductance LT when connected in series. The compensation coil must be placed on the fixed side if the armature coil is on the movable side, and on the movable side if the armature coil is on the fixed side. If the self-inductance of the compensation coil is Lc, the mutual inductance M between the armature coil and the compensation coil is set to cancel each other, and the armature coil and the compensation coil are connected in series, the overall inductance LT is LT=L+Lc-2M becomes. Since the mutual inductance M is M≦(LLc)l/2, it is possible to make M=(1,l,c)l/2 and L=L
If a compensation coil is installed so that c is obtained, LT becomes close to O. That is, by installing the armature coil and the compensation coil as close as possible, and by setting the number of turns of the compensation coil to be the same as that of the armature coil, or 0.8 to 1.2 times, the inductance T can be reduced.

When the iron core passes through the armature coil, the inductance increases, and by arranging the compensation coil and connecting it in series so that the iron core exists along with the armature coil, the effect of reducing inductance becomes greater. In particular, if the magnetic path through which the magnetic flux from the armature coil current passes is a closed magnetic path consisting entirely of iron cores, the inductance will be extremely large.

Needless to say, the reduction effect is significant. Here, the iron core refers to a yoke or magnetic material installed for other purposes that distributes the magnetic field appropriately to drive the actuator, and the closed magnetic path refers to the magnetic flux created by the armature coil current. 95 of the length of the iron core through which all paths or magnetic flux passes
shall mean more than a book.

Here, the compensation coil does not need to be one coil and may be composed of two or more, but the number of turns of the compensation coil is the number of turns of the compensation coil relative to the magnetic path of the magnetic flux created by the armature coil. It means the total number of turns. In this case, if the number of turns of the compensation coil is different in two or more magnetic paths created by the armature coil, the number of turns for each is 0.9 to 1.1.
Preferably, it is twice as large. Here, the magnetic path created by the armature means the magnetic path through which the magnetic flux generated by the armature coil current flows, and is often mainly composed of magnetic materials.
It does not have to be made of magnetic material. in this way? +
The inductance can be reduced by placing the compensation coil on the side other than the armature coil side between the moving side and the fixed side and connecting it in series with the armature coil.

Since the actuator of the present invention has the armature coils and compensation coils of the movable part and fixed part wired in series, it can be applied to an actuator that makes one repetitive motion.

Furthermore, if the armature coil or compensation coil of the movable part is connected in series with the fixed part using a brush or the like, it can be applied even to non-repetitive motions. It goes without saying that if the compensation coil installed in the present invention is placed as close as possible to the armature coil and has the same shape, the inductance LT can be reduced and the effect will be great.

Further, this compensation coil may be wound around a magnetic material such as a yoke or an iron core, or may be placed on the surface of the magnetic material.

[Example] The present invention will be explained with reference to figures of embodiments.

Figure 1 shows an actuator in which the fixed side is a field consisting of a magnet 3, the movable side is equipped with an armature coil 1, and the compensation coil 2 is wound around the center yoke on the fixed side with the same number of turns as the armature coil L. FIG. 2 is a side view taken from ab in FIG. 1. The armature coil 1 is moved in the direction indicated by the arrow 5 in FIG.
It makes repeated movements in the direction of 6°, which in Figure 2 is perpendicular to the plane of the paper. At this time, the current directions in the armature coil 1 and the compensation coil 2 are opposite to each other as shown by arrows 7 and 8 in Figure 2, and the direction of the induced voltage due to mutual inductance is shown in Figure 3. Connect the conductor 11 so that marks 12 and 13
are connected in series, and the induced voltage caused by the current is canceled out. In FIG. 3, symbols 9 and 1
0 represents the inductance of the armature coil and the compensation coil, respectively. Therefore, the inductance is reduced, the induced voltage is reduced, and the current responsiveness is improved. In FIG. 1, the yoke 4 constitutes a closed magnetic path, which is highly effective in reducing inductance.

4 and 5 show a movable magnet type actuator consisting of an armature coil 14 attached to a yoke 17 on the fixed side, and a field magnet 16 and a compensation coil 15 attached to a yoke 18 on the movable side. The figure is a view from the CD of FIG. The magnet 16 is bipolar magnetized, and the armature coil 14
The current flows in the direction 22 and makes a repetitive motion in the direction 19.20. At this time, the number of turns of the armature coil 14 and the compensation coil 15 are the same, and the armature coil I4 and the compensation coil 15 are connected in series as shown in FIG. 3, so that the inductance is low and the current response etc. Get better.

FIG. 7 shows, as in FIG. 1, a field consisting of a magnet 24 on the fixed side, a movable field (III') equipped with an armature coil 22, and a voice coil with a compensation coil 23 wound around a yoke 25 on the fixed side. 1 is a sectional view of a coil motor.Different from FIG. 1, this is an example in which two magnetic paths formed by an armature coil 22 are each provided with compensation coils 23 each having the same number of turns as the armature coil 22. Arrows 26 and 27 indicate the direction of repetitive motion of the armature coil 22. The connections between the armature coil 22 and the compensation coil 23 are illustrated in FIG.

FIG. 8 shows the ratio of turns of the compensation coil to the number of turns of the armature coil -r, and the ratio of the total inductance when the armature coil and the compensation coil are connected in series to the self-inductance L of the armature coil /L' It is a figure showing the relationship of r. It is clear that the inductance is low when the turns ratio is from 0.8 to 1.2, especially from 0.9 to 1.1.

[Effects of the Invention] According to the present invention, by providing a compensation coil in the actuator and connecting it in series with the armature coil, the inductance of the coil can be reduced, and even when current is passed through the armature coil, there is no induced voltage. small. Therefore, a high voltage is not required for the power supply, and the current rise time of the armature coil can be shortened. Furthermore, if the inductance can be lowered, the influence of the magnetic field generated by the armature coil current will be reduced.

It can show good control performance.

Since the actuator of the present invention wires the armature coils and compensation coils of the movable part and the fixed part in series, it can be applied to actuators that perform repetitive motion. If connected in series, it can be applied even to objects that cannot be repeatedly operated. It goes without saying that if the compensation coil installed in the present invention is placed as close as possible to the armature coil and has the same shape, the inductance LT can be reduced and the effect is great.

Further, this compensation coil may be wound around a magnetic material such as a yoke or an iron core, or may be placed on the surface of the magnetic material.

The present invention can be applied to motors used in 03 equipment and FAfi equipment, and can reduce power supply voltage, improve current response,
Although it is possible and effective to prevent the armature current from adversely affecting the other parts, it can also be applied to other applications when low inductance of the actuator is required.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an actuator in which a compensation coil is wound around a center yoke on the fixed side, and FIG. 2 is a side view of the actuator as seen from ab in FIG. 1. FIG. 3 is a wiring diagram of the armature coil and compensation coil. Figures 4 and 5 show a movable magnet type actuator whose movable side consists of a field magnet and a compensation coil, and Figure 6 shows a
It is a view seen from the CD in the figure. FIG. 7 shows a case where compensation coils are provided in the yokes of two magnetic paths formed by the armature coils. Figure 8 shows the relationship between the ratio of the number of turns of the compensation coil to the number of turns of the armature coil and the ratio L/L of the total inductance when the armature coil and the compensation coil are connected in series with respect to the self-inductance of the armature coil. 1. Eye, 22... Armature coil, 3.16.23-.
・Field magnet, 2.15.24... Compensation coil, 4.
18.25... Yoke for flowing magnet magnetic flux, 5.6.19
．． 20.26.27...actuator driving direction,
7, 8, 21.22-0° direction of armature coil current, 9. lO...inductance of the armature coil and compensation coil, respectively, II...conducting wire, 12.13...direction of complementary inductance.

Claims (1)

[Claims] 1. In an actuator that is driven by a current flowing through an armature coil provided on a movable side, a magnetic flux that is wired in series with the armature coil on the fixed side of the actuator, and that is generated by the armature coil. A low inductance actuator characterized in that the inductance of an armature coil is reduced by providing a compensation coil that cancels out the inductance of the armature coil. 2. In an actuator driven by a current flowing through an armature coil provided on a fixed side, a compensation coil is provided on a movable side of the actuator, the compensation coil being wired in series with the armature coil and canceling the magnetic flux generated by the armature coil. A low-inductance actuator characterized by reducing the inductance of an armature coil. 3. The low inductance actuator according to claim 1 or 2, wherein the number of turns of the compensation coil is between 0.8 and 1.2 times the number of turns of the armature coil in each magnetic path formed by the armature coil. . 4. The low inductance actuator according to claim 1, 2 or 3, wherein both the armature coil and the compensation coil have closed magnetic circuit iron cores.