JPS62225198A - Stopping device for stepping motor - Google Patents

Abstract

PURPOSE:To lesson the torque and to stop a stepping motor to the specified position accurately, by interrupting the drive pulse when the motor is to be stopped to the specified position mechanically by a stopper mechanism. CONSTITUTION:When a stepping motor 1 is moved to the position of original point, 'O' is outputted from a port P0. From an OR gate 32 the pulses. from an oscillator 31 are inputted to an AND gates 33, 34, 35 and 36. Thus the drive pulse impressed to each winding is interrupted in high rrequency corresponding to the frequency of the oscillator 31. The current flowing to the stepping motor 1 is reduced and the torque generated to the stepping motor l is decreased. The mechanical repulsive force by a stopper mechanism is so weakened that the bouncing is eliminated and the stepping motor 1 surely stops at the position of original point.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a stepping motor stopping device used, for example, to stop a stepping motor in a power steering device for an automobile at a predetermined position at the time of starting.

<Prior art> Conventionally, there is a stopping device for this type of stepping motor as shown in Figs.
No. 38658). In this stepping motor stopping device, the stepping motor 1 drives the valve 5 of the power steering hydraulic circuit via the gear 2.3. And the pin 7 provided in the gear 3 and the pin 7
A stopper 15110 consisting of an arcuate groove 8 into which the
A position (hereinafter referred to as the origin) determined mechanically by the engagement between the end surface 9 of the arcuate groove 8 and the pin 7 shown in FIG. 7 is provided.
The stepping motor 1 is stopped at the same time.

When the power is turned on, since the stopping position of the stepping motor 1 is unknown, the stepping motor 1 receives rotational drive pulses equal to or more than the number of steps required to rotate the stepping motor 1 to the origin.
the stepping motor 1 to the stopper mechanism IO
The stepping motor I is caused to step out at the origin, and the stepping motor I is stopped at the origin in a state where no rotation signal is sent.

<Problems to be Solved by the Invention> However, in the conventional stepping motor stopping device described above, when the rotational torque of the stepping motor l is large, the pin 7 of the stopper mechanism 10 collides with the end surface 9 of the arcuate groove 8, resulting in There is a problem that rebound occurs and the stepping motor l cannot be accurately stopped at the origin position.

Therefore, an object of the present invention is to reduce the torque of the stepping motor when stopping the stepping motor at a predetermined position using a stopper mechanism, thereby eliminating bounce in the stopper mechanism and accurately stopping the stepping motor at a predetermined position. The purpose is to do so.

Means for Solving the Problems In order to achieve the above object, a stepping motor stopping device of the present invention includes a stepping motor, a stopper mechanism for mechanically stopping the stepping motor at a predetermined position, and a stopper mechanism for mechanically stopping the stepping motor at a predetermined position. The present invention is characterized by comprising a chopper control circuit that chopper-controls drive pulses sent to the stepping motor when the stopper mechanism stops the stepping motor at a predetermined position.

Function> When stopping the stepping motor at a predetermined position,
The chopper control circuit performs chopper control on the drive pulses that drive the stepping motor, thereby reducing the current flowing through the stepping motor. Therefore, the rotational torque of the stepping motor is reduced, and there is almost no mechanical repulsion in the stopper mechanism, so that the stepping motor is accurately and reliably stopped at a predetermined position.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

In FIG. 1, reference numeral 1 denotes a stepping motor, which is mechanically stopped at the original position by a stopper mechanism that is exactly the same as the stopper mechanism 10 shown in FIG. The stepping motor 1 receives drive pulses φ1.0 from the driver 21 as shown in FIG. φ2. φ3. φ4 is input to each winding and driven by stepping. The drive pulses are applied to the ports PI and P2 of the microcomputer 20.
, P3, and P4. Further, a chopper control circuit 30 is provided for chopper-controlling the drive pulse when moving the stepping motor l to the origin position. This chopper control circuit 3
0 is the oscillator 31, OR gate 32, and AND gate 33
, 34, 35.36. The output of the oscillator 31 is input to one input terminal of the OR gate 32, and the output from the boat PO of the microcomputer 20 is input to the other input terminal.

In addition, the output of the OR gate 32 is connected to each amplifier gate 3.
3, 34, 35, and 36, and the microcomputer boats PI, P2. The outputs of P3 and P4 are input to the other input terminals of AND gates 33, 34, 35, and 36, respectively. And this and gate 3
3, 34, 35, and 36 outputs from the driver 21, respectively.
The drive pulses applied to the windings of the stepping motor 1 are chopper-controlled.

In the above configuration, the stepping motor 1 is used as the original/& 1. - ft, fnh6) Toss wind spring 1jf dried flute') T
i711-Senju Toshi outputs "0" from the boat PO. That is, the signal from the ignition switch is input to the microcomputer 20, and the signal from the boat PO is input to the microcomputer 20.
A 0° signal is output to the OR gate 32. On the other hand, since the oscillator 31 outputs pulses as shown in the upper part of FIG. 5, the OR gate 32 outputs pulses as shown in the upper part of FIG.
6 will be man-powered. On the other hand, the outputs from the microcomputer boats P l , P2, P3, and P4 are as shown in FIG. Therefore, and gates 33, 34,
The outputs of 35 and 36 are chopper controlled as shown in the lower part of FIG. 5 (only those for the first winding are shown). In this way, the drive pulse applied to each winding is
The current flowing through the stepping motor 1 is reduced, and the torque generated by the stepping motor 1 is reduced.

Therefore, the mechanical repulsive force by the stopper mechanism is weakened, there is no rebound, and the stepping motor l is reliably stopped at the original position.

On the other hand, when the stepping motor l is rotated by a predetermined amount, as shown in FIG. 3, the boat PO of the microcomputer 20 outputs "bi".

As a result, the output of the OR gate 32 is always at a high level, so the output of the AND gates 33, 34, 35° 36 becomes as shown in FIG. φI,
φ2. φ3. φ4 is input. As a result, the stepping motor 1 rotates with a normal large torque.

In the above embodiment, the chopper control circuit 30 is composed of an oscillator 3I, an OR gate 32, and an ant gate (33, 34, 35, 36).
However, it goes without saying that the configuration is not limited to this, and that various configurations are possible. Further, the stopper mechanism is not limited to the one shown in FIG. 6, but may have any structure as long as it can mechanically stop the stopper mechanism.

<Effects of the Invention> As is clear from the above description, the stepping motor stopping device of the present invention performs chopper control on the drive pulses sent to the stepping motor when the stepping motor is mechanically stopped at a predetermined position by the stopper mechanism. Intermittent at a high frequency in a circuit.

Since the torque of the stepping motor is reduced, the repulsion in the stopper mechanism can be reduced, and therefore,
The stepping motor can be accurately stopped at a predetermined position.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a stepping motor stopping device according to an embodiment of the present invention, Figs. 2 and 3 are flowcharts of the above embodiment, Fig. 4 is a waveform diagram of drive pulses, and Fig. 5 is an oscillator. FIG. 6 is a cross-sectional view of a conventional stepping motor stopping device, and FIG. 7 is a view taken in the direction of the ■ arrow in FIG. 6. ■...Stepping motor, 5...Valve, 7...
Pin, tail... arcuate groove, 10... stopper mechanism, 20
...Microcomputer, 21...Driver,
30... Chopper control circuit, 31... Oscillator, 32
...or gate, 33, 34, 35. 36... and gate. Patent applicant: Koyo Seiko Co., Ltd. Agent
Patent Attorney Blue and White (Yome 12 people 1st!! 1 121! I @ 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] (1) A stepping motor, a stopper mechanism for mechanically stopping the stepping motor at a predetermined position, and chopper control of drive pulses sent to the stepping motor when the stepping motor is stopped at the predetermined position by the stopper mechanism. A stepping motor stopping device characterized by comprising a chopper control circuit.