JPS6022488A - Speed regulating device - Google Patents

Abstract

PURPOSE:To enable to independently set the accelerating time, decelerating time and a normal speed by providing acceleration/deceleration setters, an integrator with a limiter for integrating the outputs of the setters, a normal speed setter to form a speed regulating controller. CONSTITUTION:A power source 2 is connected through a bidirectional SCRs 31- 33 to an induction motor 1, the output of a governoring controller 4 is inputted to a trigger circuit 5 to control the SCRs 31-33, thereby controlling the rotating speed of the motor 1. A speed regulating controller 4 is formed of a normal speed setter VR1, an acceleration setter VR2, a deceleration setter VR3 and an integrator OP2 with a limiter. A relay 45 is operated by the operation of a switch S2 at the accelerating time, the voltage of the VR2 is applied to an OP2 to lower the output at the constant gradient to the constant value, outputted through an operational amplifier OP4, and operated similarly at the decelerating time. Accordingly, the controllability can be improved individually at the accelerating, decelerating, normal speed time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed governor for controlling the speed of an induction motor.

In devices configured to use electric motors to drive various movable bodies, it is necessary to gradually accelerate the motor when starting up and gradually decelerate when stopping, in order to avoid applying unnecessary shock to the movable body. Ru. FIG. 1 shows acceleration characteristics at startup when a conventional induction motor speed governor is used. If the set rotational speed (speed) is set to N+, the rotational speed will gradually increase exponentially over time and will eventually reach N1. This is configured such that a speed regulating control signal having a voltage level corresponding to the rotation speed is obtained by a CR charging circuit.
This is because the charging terminal voltage of this CR charging circuit shows a radial change as shown in FIG. If the rotational speed is set to N2, which is higher than N1, the rotational speed increases exponentially with a steeper slope.

Conventional speed governors exhibiting such acceleration characteristics have the following disadvantages. That is, as is clear from the comparison of both curves in Fig. 1, the acceleration differs depending on the set speed, and the acceleration time (the time from startup to reaching steady speed) is determined depending on the set speed. , the boundary between the transient period during acceleration and the steady period of constant speed is not clear;
These points also apply during deceleration.

The present invention has been made to eliminate such inconveniences.Acceleration time, deceleration time, and steady speed can be set independently, and in the deceleration process, a second speed slower than the steady speed can be set independently. It is an object of the present invention to provide a speed governor that can independently set the steady speed of the motor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 2 schematically shows the entire circuit for driving the three-phase induction electric motor Ia1.

A bidirectional SCR3L32°33 is interposed in the middle of the three-phase line of T, and the neutral point of the induction motor 1 and S
A braking S is connected between the phase terminal and the cathode on the neutral point side.
CR34 is connected.

A speed governor control circuit 4, which is a main part of the present invention, outputs a speed control signal having a voltage level corresponding to the number of revolutions (speed) of the induction motor 1, and supplies this to a speed governor trigger circuit 5. The speed regulator trigger circuit 5 controls the SCR 31, at a phase according to the input voltage.
Trigger pulses are issued to gates 32 and 33. In other words, when the input voltage from the speed governor control circuit 4 is high (low), the conduction phase is set earlier (lower) to increase (lower) the effective value of the voltage supplied to the induction motor 1, thereby increasing (lowering) its rotational speed. )
let When the rotation of the induction motor 1 is to be stopped, the brake trigger circuit 6 applies a trigger pulse to the 5CR 34 to short-circuit the S-phase winding, thereby shortening the time until the rotation of the induction motor 1 is stopped.

Next, the configuration of the speed governor control circuit 4 will be explained based on FIG.

Reference numeral 41 denotes a power supply circuit which rectifies the three-phase power supply 2 to create a DC constant voltage, supplies +vcc to the positive line 42, and supplies +vcc to the negative line 4.
-VBB is output to 3.

The switch S1 is a switch to be operated according to the frequency of the three-phase power supply 2, and its common terminal is connected to one end of a variable resistor VR+ for setting the steady speed. One switching side terminal is a variable resistor v11.0 for setting a steady speed of 60Hz. 1.1, the switching side terminals of the external power are each connected to one end of a variable resistor J:I VR5 for setting a constant speed for 50 tlz. The steady speed setting is mainly performed by adjusting the variable resistors VR, and the variable resistors V11. .

VR5 is set to compensate for the difference between 6011z and 5011z, and switches 'ζ switch S1 according to the frequency.
can be switched. The other ends of the variable resistors VR+ and Vll are connected to their respective intermediate terminals, and are also connected to the output 1yg1 of the operational amplifier OP2, which will be collectively described later, and the operational amplifier O.
It is connected to one input terminal of P3. Variable resistor VR+
The other end is connected to a ground line 44. Further, its intermediate terminal is connected to the input terminal of the operational amplifier OP4.

The switch S2 is an acceleration/deceleration changeover switch, and the common terminal is connected to the positive line 42 via the coil 45C of the electromagnetic relay 45.
It is connected to One switching side terminal to be turned on during acceleration is connected to the negative electrode line 43.

The other switching terminal, which should be turned on during deceleration, is left empty.

The low speed rotation command switch S3 is a switch for commanding temporary constant speed rotation at a low second constant speed during deceleration, and is closed when this command is issued, and is opened when continuous deceleration is required. . One terminal is diode 46
The other terminal is connected to the intermediate terminal of a variable resistor VI+6 for setting a second steady speed. The anode of the diode 46 is connected to the input terminal of the operational amplifier OP.

The variable resistor v1?6 is connected to the ground line 44. Negative electrode line 43
It is interposed in between.

A series circuit of a plurality of resistors including a variable resistor VR2 for setting acceleration time or acceleration is connected between the positive electrode line 42 and the ground line 44, and the intermediate terminal of the variable resistor VR2 is connected to an electromagnetic relay 45. Connect to the normally open terminal of the contact part. On the other hand, a variable resistor V for setting the deceleration time or deceleration (i.e., negative acceleration) is connected between the negative electrode line 43 and the ground line.
A series circuit of a plurality of resistors including R3 and a 1-transistor 47 is connected, and the intermediate terminal of the variable resistor &R3 is connected to the normally closed contact of the contact portion of the electromagnetic relay 45. The common terminal of this contact part is connected to the operational amplifier O through a resistor 50.
It is connected to one input terminal of P2.

The operational amplifier 2 constitutes an integrating circuit together with a 21 capacitor 48 and a Zener diode 49 connected in parallel between its one input terminal and its output terminal, and the Zener diode 49 has its cathode connected to one input terminal. I'm on your side. The →-input terminal of the operational amplifier OP2 is connected to the ground line 44 via a resistor.

The output of this integrator circuit, that is, the output terminal voltage of operational amplifier OP2, is directed (linearly with However, when the voltage applied to the - input terminal becomes -1- higher than the Zener voltage of the Zener diode 49, the output voltage does not rise any further.

That is, this integrating circuit operates as an integrating circuit with a limiter.

The operational amplifier OP3 is used to configure a zero-volt switch circuit together with the I/transistor 47, and its input terminal is connected to the ground line 44 through the Y-AJ resistor, and the output terminal is connected to the ground line 44 through the resistor. It is connected to The →-input terminal of operational amplifier oP3 is at ground level (zero volts), but when the -input terminal voltage rises from a negative voltage and reaches zero volts, its output terminal changes from high level to low level, and then The transistor 47, which had been on until now, is turned off.

The operational amplifier 4 is an output circuit that connects one input terminal and an output terminal to operate as a voltage follower. The intermediate terminal voltage of the variable resistor VRI is directly connected to the ten input terminals.
In addition, the variable resistor VR6 is connected via the forward diode 46.
Since the intermediate terminal voltages of the input terminals are respectively applied, the voltage of the ten input terminals becomes the lower voltage of the inner input terminal. The amplified output of such an input voltage is given to the speed regulating trigger circuit 5.

The apparatus of the present invention, which has several dozen configurations, is used and operated as follows. First, the switching position of the switch S1 is selected depending on the power supply frequency. The values of the variable resistors VR4°VB5 are adjusted in advance as necessary.

Next, accelerate by adjusting variable resistors VR2 and VB2.

The deceleration time is set, and the steady speed is set by adjusting the variable resistor VRIO. If the rotation is to be performed at the second steady speed during deceleration, the speed can be set using the variable resistor VR.
, 6. Set by adjusting.

After doing this, a switch (not shown) between the power source 2 and the electric motor 1 is closed, and the switch s2 is turned on to the acceleration side. Then, the coil 45C of the electromagnetic relay 45 is energized and its contact is switched to the normally open terminal side. As a result, one input terminal of the operational amplifier blade 2 is given the intermediate terminal voltage of the variable resistor νR2.

Then, the integrating circuit including the operational amplifiers 01 and 2 integrates with a time constant determined by the resistance value of the resistor 50 and the capacitance of the capacitor 48, and the output of the operational amplifier oP2 decreases at a constant slope as shown in FIG. . and capacitor 48
When the voltage reaches the Zener voltage of the Zener diode 49, the output of the operational amplifier OP2 becomes Vz as shown in FIG.
becomes constant. At this time, the switch S3 is open, so the voltage Vz becomes a voltage according to the setting values of the variable resistor v1 or VRs and VRI, and is applied to the ten input terminals of the operational amplifier, and the voltage Vz becomes a voltage according to the input voltage. is the operational amplifier o
He will be removed from P4. FIG. 5 shows the change in the rotational speed (speed) of the electric motor 1 following the output of the operational amplifier blade 4, and the slope of the acceleration period is linear, that is, the acceleration is constant. Furthermore, the time point at which the acceleration period changes from the steady speed period (the time point when the voltage of the capacitor 48 reaches the Zener voltage) is also clear.

When the electric motor 1 is to be decelerated and stopped after being rotated at a constant speed in this manner, the switch S2 is switched to the deceleration side. This demagnetizes the coil 45C.

Then, the contact of the electromagnetic relay 45 is switched to the normally closed contact side shown, and a negative voltage determined by the variable resistor νR3 is applied to one input terminal of the operational amplifier OP2.

However, the negative operational amplifier OP2 output is operational amplifier oP3.
This is because the output of the operational amplifier OP3 turns on the transistor 47.

When a negative voltage is applied to the operational amplifier OP2 by switching the switch S2, its output increases at a constant slope according to a time constant determined by the capacitance of the capacitor 48 and the resistance value of the resistor 50. Eventually, the output becomes O. Then, the output of the operational amplifier OP3 is inverted from positive to negative, which turns off the transistor 47.

Then operational amplifier OP2.011. The output becomes 0 and the power supply to the electric motor 1 is stopped.

Even in such a deceleration process, the gradient of the deceleration period is constant as shown in FIG. 5, and the time point at which the steady speed period changes to the deceleration period is also clear.

Therefore, the electric motor] Stop 1. If it is desired to avoid movement of the movable body driven by the electric motor 1 due to later inertia, the switch S2 is switched to the deceleration side and when the deceleration has been reduced to the required extent, the switch S3 is operated to close the circuit.

Then, the voltage at the intermediate terminal of the variable resistor ν1?1 becomes negative as before. Then, when the ζ switch S3 is closed, its voltage becomes higher than the intermediate terminal voltage of the variable resistor VR6. Then, the voltage at the input terminal of the operational amplifier Oh becomes the lower output voltage of the variable resistor VR6, and the output of the operational amplifier OP4 becomes constant as shown by the two-dot chain line in Fig. 4, and the motor 1 becomes as shown in Fig. 5. As shown, it rotates at a slow second steady speed.

1 If switch S3 is opened at any time, the voltage corresponding to the output of operational amplifier OP2 at that time will be applied to the operational amplifier OP.
, and decelerated rotation or stop is performed at a corresponding speed. In the illustrated example, the output of the operational amplifier OP2 is already 0 when the switch S3 is opened, so that the current supply to the motor 1 is immediately stopped when the switch S3 is closed.

As described above, in the case of the device of the present invention, the variable resistor VR2
, Vl? 3, the acceleration (deceleration) speed or acceleration (deceleration) time can be independently set, and the steady speed can be independently set using the variable resistor VRl, etc. Furthermore, by providing an integrating circuit with a limiter, the time point at which the acceleration period changes from the steady speed period becomes clear. In addition, in this embodiment, the electromagnetic relay 45 is switched by switching the switch S2, and the polarity of the voltage for generating the speed control voltage is reversed, so that the change point between the steady speed period and the acceleration period is also clear. Become.

Furthermore, in the apparatus of the present invention, rotation can be performed at a low second steady speed before stopping, and this speed can also be set independently of other speeds and deceleration.

In this implementation 1111, the normally closed contact of the electromagnetic relay 45 is used for the deceleration side, so even if the electromagnetic relay 45 does not operate due to some kind of circuit failure, the motor will be decelerated, providing a failsafe. .

As described above, the speed governor according to the present invention is a speed governor for a motor that uses a voltage related to the speed of the motor as a speed control signal, and includes: an acceleration setter that outputs a voltage corresponding to acceleration; an integrating circuit with a limiter that integrates the voltage output by the integrating circuit; a steady speed setting device that outputs a voltage related to the output voltage of the integrating circuit; the integrating circuit output is compared with a predetermined voltage, and if the comparison results match; and a switch circuit that sets the output of the acceleration setter to a voltage corresponding to rotation stop +1-, and is configured to use the voltage related to the output of the fixed seat speed setter as a speed regulating control signal. It has excellent effects such as being able to independently set each element during deceleration and steady rotation.

[Brief explanation of the drawing]

Figure 1 is a graph showing the acceleration characteristics of a conventional speed governor.
Fig. 2 is a circuit diagram showing the relationship between the device of the present invention, an electric motor, and a power source; Fig. 3 is a circuit diagram showing one embodiment of the device of the present invention;
5 are time charts for explaining the operation of the apparatus of the present invention. OF2, OF2, O20... operational amplifier S
I+S2+S3...Switch νR+, VR2...
・VR6...Variable resistor 45...Electromagnetic relay 4
6...Diode 47...Transistor 48...
・Capacitor 49... Zener diode patent Applicant Tsubakimoto Chain Co., Ltd. Agent Patent attorney Noboru Kono 5 469-'44 Former 81st Section No. 5 Figure procedural amendment (voluntary) November 1, 1981 Blind patent Mr. Commissioner of the Agency/Display of the case 1981 Patent Book No. 129915 2 Name of Issue 811 Speed governor 3 Relationship with the case of the person making the amendment Details of the invention of the patent applicant Da-jji 11-use Tsumugi-kutsu Figure 2 and Supplementary Contents 6-1 ``Detailed Description of the Invention'' Column ``Radial change'' on page 3, line 14 of the specification has been replaced with ``exponential change''. ``Changes in ``. 6-2 Drawing

Claims (1)

[Scope of Claims] (1) A speed governor for a motor that uses a voltage related to the speed of the motor as a speed control signal, comprising: an acceleration setter that outputs a voltage corresponding to acceleration; and a voltage output by the acceleration setter. an integrating circuit with a limiter that integrates the output voltage of the integrating circuit; a steady speed setting device that outputs a voltage related to the output voltage of the integrating circuit; and comparing the output of the integrating circuit with a predetermined voltage, and when the comparison results match, setting the acceleration. 1. A speed governor, comprising: a switch circuit that sets the output of the steady speed setting device to a voltage corresponding to stopping rotation, and is configured to use a voltage related to the output of the steady speed setting device as a speed governor control signal. 2. In a motor speed regulating device that uses a voltage related to the speed of the motor as a speed regulating control signal, there is an acceleration setter that outputs a voltage corresponding to acceleration, and a limiter that integrates the voltage output by the acceleration setter. an integrating circuit; a first steady-state speed setter that outputs a voltage related to the output voltage of the integrating circuit; a first steady-state speed setting device that compares the output of the integrating circuit with a predetermined voltage; and when the comparison results match, the output of the acceleration setting device; a switch circuit that outputs a voltage corresponding to rotation stop; a second steady speed setter that outputs a voltage that can be set appropriately; and a switch circuit that outputs a voltage that corresponds to stopping rotation; A speed governor, comprising: a circuit for selectively outputting one of the two, and configured to use a voltage related to the output of the circuit as a speed governor control signal.