JPS5933047Y2 - electric positioner - Google Patents

Description

[Detailed explanation of the invention] This invention converts an electrical input signal into an electrical driving force,
This is an electric positioner that uses this driving force to control the position of a controlled object according to an input signal.It eliminates the effects of noise and surges on electronic circuits, and also changes the potentiometer-based feedbank mechanism to a mechanical feedbank mechanism. This improves reliability.

In general, an electroelectric positioner includes a deviation detector that compares an input electrical signal and a feedback electrical signal, a deviation signal amplifier, a motor having a forward and reverse direction of the amplified signal, a motor drive circuit that changes the driving force, and a reversible motor and
It consists of a speed reducer and a potentiometer rotated by the speed reducer output, and the feedback voltage from the potentiometer is fed back to the deviation detector.

However, since the signal transmission processing circuit is composed of electronic circuits, it is easily affected by noise and surges (for example, surge voltages caused by electric shocks) in the electrical signal transmission path, and malfunctions of the electronic circuits can cause the motor to This may lead to destruction and burnout of mechanical parts such as reducers.

Additionally, potentiometers with sliding parts are prone to wear and poor connections, requiring frequent inspection and repair.

This idea solves the above problems by using force smoke in the receiving section to make it resistant to noise and surges in the electronic signal transmission path, and by making the feedback mechanism mechanical, it improves performance and lifespan. This is an attempt to make major improvements.

The following questions will be asked regarding the drawings.

1 is a permanent magnet, 2 is a magnetic pole, 3 is an input signal coil, 4 is a leaf spring, 5 is an armature, 6 is an input signal, 7 is a flag, 8
, 8' is a photosensor, 92g is a flip-flop circuit, 10, 1σ is a timer, 11, 11' is an amplifier, 1
2.12' is the output relay, 13 is the motor 1 drive circuit, 1
4 is a reversible motor, 15 is a speed reducer, 16 is a load, 17 is a feed bank lever, 18 is a span adjustment pin, 19 is a span adjustment lever, 20 is a feedback spring, 2
1 is a zero adjustment spring, 22 is a comparator, 23 is a potentiometer, and 24 is a holding amplifier circuit.

The configuration of this electro-electric positioner is as shown in Fig. 1, and includes an input signal receiving section that uses electromagnetic force, that is, a force smoke, and a fixed amount of positive and negative displacement of this force smoke, that is, a force change from the equilibrium position of the armature in the force smoke. two photosensors that respectively detect the deflection direction; a holding means that stores and holds the ±I+111 output of the photosensors using a flip-flop circuit or the like;
It is comprised of a motor 1 drive circuit that determines the rotational direction of the motor that drives the controlled object according to the positive or negative sign of the held signal, and drives the motor 1, and a mechanical feedback mechanism that is interlocked with the operation of this motor.

There is hysteresis in the forward and reverse displacement detection of the photosensor, and the dead zone in the forward and reverse directions due to hysteresis is the second
As shown in Figure a, if two photosensors are placed in perfect alignment, hunting will occur in the entire control system, so as shown in Figure 2, c, and d, the dead zones may overlap partially or completely. They should be arranged so that they do not overlap.

In the case of C2d in FIG. 2, if an RS type flip-flop circuit is used, only one flip-flop circuit is required.

Note that the hysteresis of the photosensor is commercially available, with a nominal hysteresis of 0.02 mm or less, and a measured value of about 0.01 to 0.015 mm.

Next, this electric positioner is attached to a motor-driven valve actuator that performs two-position stop control (open and close).
The effects of positioning the valve stem for opening and closing the valve will be explained.

Now, assuming that the relative position between the photosensor 8 and the flag 7 at the tip of the armature 5 is as shown in Figure 2, the armature 5 at the neutral point moves in the direction () due to the increase in the input signal 6, and the photosensor 8 turns ON. becomes.

Then, the flip-flop circuit 9, timer 10, amplifier 11, and output relay 12 are operated in sequence, the motor is driven once, and the feedback lever 17 is moved upward.

As a result, the feedback spring 20 is pulled downward, and the flag 7 at the tip of the armature 5 is returned to the position where the photosensor 8 is turned off, thereby achieving balance.

In Figure 2, photosensor 8. When either &' is activated, the motor 14 is driven, and when either of the same photosensors 8, 8' is turned off, the motor 14 is stopped.
In FIG. 2C2d, when both photosensors 8 and 8' are activated, the motor 14 is stopped and 8 and 8'
The motor 14 is driven when the photosensor turns off due to the fall of the motor.

To summarize these effects, the positive f+ 111 signal from the photosensor 8 can be made to Except when switching to negative +1111 by photosensor 8' or vice versa,
Even if noise or surges generated in the electrical input signal transmission path are superimposed on the input signal, the valve stem will not be affected by them, so the valve stem will not suddenly stop or reverse during normal movement, or if it does not move as expected. There is no possibility of breaking through the stopping position.

Furthermore, since the feedback mechanism is a mechanical type with a long life, the valve stem (load 16) always stops smoothly and accurately at the valve open and valve closed positions.

In addition to the above, force smoke 1 to γ is used in the input receiving section, and the low impedance of the coil and the high voltage resistance of the coil material provide strong noise and surge resistance.Furthermore, the electrical amplification circuit is also used as the optical sensor's second Since the position output is output through each logic, the operation check can be easily carried out using a measurement device similar to a circuit tester (circuit desk), which has many useful effects in practical terms. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram and drawings showing the configuration of the present invention, FIG. 2 is a diagram showing hysteresis in displacement detection of a photosensor, and FIG. 3 is a block diagram showing the configuration of a conventional electro-electric positioner. Explanation of symbols, 1: Permanent magnet, 3: Coil, 5: Amateur, 8: Photo sensor, 9: Flip-flop circuit,
17: Feedback lever, 19 Nispan adjustment lever, 2
0: Feedback spring, 21: Zero adjustment spring.

Claims (1)

[Scope of utility model registration request] A device that converts an electrical input signal into an electrical driving force and controls the position of a controlled object according to the electrical input signal, which includes a firing magnet, an input signal coil, and an armature, and a force smoke that receives the electrical input signal. , two photosensors for respectively detecting the direction of deviation of the armature from the equilibrium position in the force smoke, a memory holding means for holding and storing the outputs of these photosensors, and a memory holding means according to the output of the memory holding means. A motor that drives a controlled object in forward or reverse rotation, a drive circuit, and a drive circuit that is linked to the rotational operation of the motor and whose displacement is negatively fed back to the displacement caused by the armature's electric input signal in the force smoke. An electrical positioner characterized by being equipped with a mechanical feedback mechanism.