JP3248085B2 - Actuator drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for moving an actuator such as a solenoid or a shape memory alloy.

[0002]

2. Description of the Related Art Conventionally, as a driving device for driving an actuator such as a solenoid biased to one side by a spring against a spring force and controlling the position of a mechanism member such as a lever at a fixed position, There is one as shown in FIG.

A voltage v1 corresponding to the operating position of the actuator 101 is generated by a potentiometer vr1 linked to the actuator 101, and a setting means vr2
The voltage v2 corresponding to the set position of the setting means vr2
The two voltages are compared and amplified by a comparison amplifier 102 composed of an operational amplifier or the like, and the transistor TR101 is turned on / off according to the output to control the current flowing through the actuator 101.

In a normal state, since the voltage v1 is set to be lower than the voltage v2, the output of the comparison amplifier 102 is low, the transistor TR101 is turned off, and the actuator 101 does not move. When the voltage v2 is made lower than the voltage v1 by changing the setting means vr2, the comparison amplifier 10
2 output voltage rises and turns on the transistor TR101
Then, a current is supplied to the actuator 101 to move the actuator.

[0005] In conjunction with the movement, the potentiometer vr
1 is made to decrease, and the voltage v1
Is slightly lower than the voltage v2, the current stops, and the output voltage v1 of the potentiometer vr1 increases, and the voltage v
2 becomes lower than the voltage v1 again, and a current flows. By repeating this, the actuator 101 is held at a desired position determined by the setting position of the setting means. Here, TR101 and R101 are overcurrent prevention circuits.

[0006]

According to the prior art, since the current flowing through the actuator 101 when the setting means vr2 is changed is constant, depending on the type of the actuator used, a sudden change in the setting means vr2 is prevented. There was a problem that the response speed of the actuator was slow.

For example, since the shape memory alloy actuator changes its shape due to a rise in temperature due to self-heating due to energization, there is a disadvantage that the response time from the start of energization to the change in shape is long.

If the current flowing through the actuator 101 is increased from the beginning in order to speed up the response time, the large amount of current flows even in a steady state, so that the pulsation of the movement amount of the actuator 101 is large and the power consumption is large. Will happen.

An object of the present invention is to provide an actuator drive device which can increase the response speed of the actuator when the operation position of the actuator is set by the setting means.

[0010]

In order to solve the above problems, the present invention provides an actuator driving device for controlling the energization of an actuator to operate the actuator, wherein a first current is supplied to the actuator. First energization control means for energizing and holding the actuator at a desired position, state setting means for setting an operation position of the actuator, detection means for detecting a speed change when the state of the setting means changes, possess the first current based on the output of the detection means when the state change of the setting means and a second power supply control means for adding the second current, said second current control
The means comprises an adjusting means capable of adjusting a period during which the second current flows.
It has a configuration with a step . As the setting means, a potentiometer is applicable.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the embodiments shown in the accompanying drawings.

FIG. 3 shows an actuator 1 used in the present invention.
The following shows an example. The lever 13 slidable in the hole 20 a of the case 20 is provided with a wall surface 20 b and a slider holding portion 13.
a is urged to the left by a tension spring 14 fixed to a. The pulley 15 is provided on the pulley holding portion 13a of the lever 13.
Is held rotatably, and the pulley has a linear shape memory alloy 1
7 has the other end fixed to the terminals 18a and 18b, and is hung in a stretched state. Reference numeral 4 denotes a potentiometer for detecting the operating position of the lever 13 in the left-right direction. The slider 4a is fitted in a groove 13c of the slider holding portion 13a. Output leads 4b and 4c of the potentiometer 4 are connected to terminals 19a and 19b, respectively.

When a voltage is applied to the terminals 18a and 18b to cause a current to flow, the shape memory alloy 17 contracts in length due to self-heating caused by its own resistance, and moves the lever 13 to the right. Is also moved to increase its resistance value. Terminal 18
a, when the voltage application to 18b is stopped, the shape memory alloy 1
7 is naturally cooled and stretched by a tension spring 14,
The lever 13 is moved to the left.

FIG. 1 is a circuit diagram showing an embodiment of an actuator driving device used in the present invention, and FIG. 2 is a timing chart. Block 5 is a circuit using the conventional technology, and is a first energization control unit. A voltage V2 generated by the potentiometer VR2 as the setting means 2 and corresponding to the set position of the potentiometer VR2, and a potentiometer 4 (V
R1) is compared with a voltage V1 corresponding to the operating position of the actuator 1 by the comparator IC1.
Resistors R5, R6, R7, R8, R9, R10, R11,
The transistor Q1, Q2, and the capacitor C3 constitute a comparison amplifier. As shown in FIG. 2, if the voltage V2 is higher than the voltage V1, the transistor Q1 turns on and the first current I1 flows through the actuator 1. . C3 is a capacitor for preventing oscillation, and C1 and C2 are capacitors for preventing noise.

Block 3 is an additional second energization control means for implementing the present invention. At time t1 in FIG.
Connect potentiometer VR2 to lever 1 of actuator 1.
When the voltage V3 is changed so as to move to the right, that is, to energize the shape memory alloy 17, the voltage V2 sharply increases. Only this voltage change ΔV is applied to the capacitor C4 and the resistor R.
14 to obtain an amplifier IC2 and a resistor R
12, R13, R15, a variable resistor VR3, capacitors C6 and C8, and the voltage is amplified by an amplifier circuit to generate a voltage V3. VR3 is a variable resistor for adjusting the amplification factor, and C5 is a capacitor for preventing oscillation.

Amplifier IC3, resistors R16, R17 and R
A second comparison amplifier is constituted by 18, and when the voltage V3 becomes equal to or lower than the voltage V4 determined by the variable resistor VR4 as the adjusting means at the time t2 in FIG. 2, the transistor Q3 is turned on. I have. As a result, the resistance R21
Also turns on the transistor Q5, and the voltage V3 becomes the voltage V
The second current I2 flows until t3, which becomes 4 or more. The resistor R19 and the transistor Q4 in FIG. 1 are a current limiting circuit. Therefore, during the period from t2 to t3, the current I corresponding to the first current I1 + the second current I2 flows through the actuator 1, so that the shape memory alloy is heated more rapidly than before, and the response time becomes longer. Be shortened.

When the potential of the potentiometer VR2 is largely changed or the change speed is high, the change of the voltage V3 is large, so that the time required for the second current I2 to flow is prolonged and the responsiveness is further improved. become.

The voltage V is adjusted by adjusting the variable resistor VR4.
By changing 4, the point between t2 and t3, that is, the period during which the current I2 flows can be adjusted according to the characteristics of the actuator.

[0019]

According to the structure of the present invention, when the operating position of the actuator is set by the setting means, the amount of power to the actuator is increased based on the speed change when the state of the setting means changes, and the response speed of the actuator is increased. Can be faster. In addition, in the steady state, the operation of the actuator is stabilized because no excess current flows, so that the power consumption can be reduced. Also, a period in which the second current is caused to flow by the adjusting means.
Can be adjusted according to the characteristics of the actuator.
Suitable for individual actuators with different characteristics
The response speed can be controlled.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the embodiment of the present invention.

FIG. 3 is a sectional view of an embodiment of the present invention.

FIG. 4 is a circuit block diagram showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Actuator 2 Potentiometer (setting means) IC3 Comparator (detecting means) 3 Block (second energizing control means) 5 Block (first energizing control means) I1 First current I2 Second current VR4 adjusting means

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G05D 3/00-3/20 H01F 7/18

Claims (2)

(57) [Claims] 1. An actuator driving device for operating an actuator by controlling energization of the actuator, wherein a first current is applied to the actuator to hold the actuator at a desired position. Control means; state-variable setting means for setting the operating position of the actuator; detecting means for detecting a speed change when the setting means changes in state; based on an output of the detecting means when the setting means changes in state. Te have a second power supply control means for adding the second current to the first current, the second current control means, the period to flow the second current
A driving device for an actuator, comprising: an adjusting unit capable of adjusting the distance. 2. The actuator driving device according to claim 1, wherein said setting means is a potentiometer.