JPH03293959A - Compound driving device - Google Patents

Abstract

PURPOSE:To rotate or shift a needle straight at a higher speed with every fixed step angle by driving it with the resultant force of the thrust generated by a stepping motor and the thrust generated by a voice coil motor. CONSTITUTION:A linear shift-type stepping motor comprises a stator 2, a needle 3, and ball bearings 4a and 4b. A voice coil motor comprises a needle, a coil 5a, and a stator 6. And the needles 3 and 5 of each motor are connected by a connecting material 7, and constitute a needle 8. That is, the needle 8 is driven by the composite force of the thrust generated by the stepping motor and the thrust generated by the voice coil motor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a composite power device constructed by combining a linear moving stepping motor and a voice coil motor.

[Conventional technology]

Conventionally, this type of power device includes a rotary type or a linear movement type stepping motor. As is well known, a stepping motor consists of a plurality of stepping motors (usually two).
Thrust is generated by passing current through the coils, the mover stops at a certain stable point, and by sequentially switching the direction of the current flowing through the multiple coils, the movable element is moved at a certain step angle. The movable element rotates or moves straight. In addition, as is well known, a voice coil motor generates a thrust according to the left-hand rule of the seven lemmings, rather than passing a current through the coil.

[Problem to be solved by the invention]

However, although it is easy for a stepping motor to stop at a stable point at each fixed step angle, when the direction of the current flowing through the coil is switched, the current changes depending on the time constant determined by the inductance and resistance of the coil. There was a problem in that the increase/decrease in the amount of power was exponential, so that sufficient thrust was not generated immediately after switching, resulting in the device not functioning as a power generating device. This is even more so when the switching period of the current is shorter than the time constant. In other words, there was a problem in that it was not possible to rotate or move straight at a faster speed. Further, although the voice coil motor can easily generate thrust, there is a problem in that it cannot be stopped at a stable position.

Note that the time constant determined by the inductance and resistance of the coil of the voice coil motor is generally smaller than the time constant determined by the inductance and resistance of the coil of the stepping motor.

[Means to solve the problem]

In order to solve such problems, the composite power device according to the present invention includes a linear moving stepping motor, a voice coil motor, and a movable element of the voice coil motor connected to a movable element of the stepping motor through an engaging member. and a movable body to be engaged.

[Effect]

In the present invention, the movable body is driven by the combined force of the thrust generated by the stepping motor and the thrust generated by the voice coil motor.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a composite power plant according to an embodiment of the present invention. In the figure, 1 is a support base, and 2 is a stator of a stepping motor, which has two coils and magnetic pole teeth (not shown). Reference numeral 3 denotes a movable element of a stepping motor which, although not shown, has magnetic pole teeth and is movable in the left and right directions in the figure. The principle of movement is the same as a conventional stepping motor. The stator 2, movable element 3, and ball bearings 4m and 4b constitute a linear moving stepping motor. Reference numeral 5 denotes a cylindrical mover that supports the coil 51 of the voice coil motor and is movable in the left-right direction in the figure, and its cross section is shown in the figure. Reference numeral 6 denotes a stator of the voice coil motor, which is composed of a shimagnet. The movable element 5, coil 5&, and stator 6 constitute a voice coil motor. Reference numeral 7 denotes a member for engaging the movable element 3 and the movable element 5, and these engaging members T, the movable element 3, and the movable element 5 constitute a movable body 8.

FIG. 2 is a diagram showing the operation timing of the current flowing through each coil and the thrust force during operation of the embodiment of FIG. 1. In the same figure, the figure (,) shows the current flowing through one of the two coils of the stepping motor (this is taken as the human phase), and the figure (b) shows the current flowing through the other of the two coils of the stepping motor (this is assumed to be the human phase). (C) is a diagram showing the current flowing in the coil 5 of the voice coil motor. FIG. Note that 111 to 11e are lines with zero current. Further, in the figure, 10 & to 1 oh indicate the timing at which the direction of the current flowing through each coil of the stepping motor is switched, and the horizontal axis indicates time.

Figure (d) shows the thrust generated in the moving element 3 of the stepping motor, Figure (,) shows the thrust generated in the voice coil motor's moving element 5, and Figure (f) shows the thrust generated in the moving element 5 of the stepping motor. 11a to 11f are lines of zero thrust. FIG.

The composite power device constructed in this way is first constructed by connecting two coils in the stator 2 of the stepping motor (see Fig. 2).
By supplying the coil human-phase current and the coil B-phase current shown in ) and (b), respectively, a thrust as shown in FIG. 3(d) can be obtained in the movable element 3 of the stepping motor. In addition, by supplying the coil current shown in FIG. 5C to the coil 5a of the voice coil motor, thrust as shown in FIG. Therefore, the movable body 8 has the same figure (Figure 1) which combines both thrust forces.
The thrust shown in f) will be obtained.

Then, at the timing 10 in the figure, the direction of the current flowing through the coil of the stepping motor is switched.
By passing current through the coil of the voice coil motor for a certain period of time from 10 hours after the start, the movable element 5 of the voice coil motor generates thrust only during that period. Sufficient thrust is obtained for the body 8. Note that the current value and time of the current flowing through the coil 5 of the voice coil motor do not need to be constant values, and can be changed according to the cycle from the switching timing 10 breaths to 10 hours.

〔Effect of the invention〕

As explained above, according to the present invention, the motor is driven by the combined force of the thrust generated by the linear moving stepping motor and the thrust generated by the voice coil motor.
An extremely excellent effect can be obtained in that the mover can rotate or move straight at a higher speed at each fixed step angle.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the composite power plant according to the present invention, and FIGS. 2(f) to 2(f) are diagrams showing the timing of operations in the embodiment of FIG. 1. 1φ...Support stand, 2...Fist e stepping motor stator, 3...Stepping motor mover, 4.4
m, 4b--pot/ball bearing, 5--ψ-voice coil motor mover, 5a-amon voice coil motor coil, 6--voice coil motor stator, 7--conflict/engagement Member, 8φ--movable body.

Claims (1)

[Claims] A composite power device comprising a linear moving stepping motor, a voice coil motor, and a movable body that engages the movable element of the voice coil motor with the movable element of the stepping motor via an engagement member. .