JPS62185577A - Speed instructing circuit - Google Patents

Abstract

PURPOSE:To gradually decelerate and stop a load without applying an excess impact force to the mechanism of a rotor at stopping time by providing a time constant circuit in the output circuit of a speed setter. CONSTITUTION:When a stop switch 1 is closed, it signal is supplied to a noise filter 2, and an output signal is supplied from the output of an FF circuit having NAND gates 11, 12 through an inverter 3 to a transistor switch 4 to turn OFF a transistor switch 9. The charge of a capacitor 13 is gradually discharged by a specific time constant through a resistor 6 and a speed setter 5. Accordingly, an output pulse is not abruptly eliminated, and it can avoid the stop of the rotation of a load.

Description

[Detailed Description of the Invention] "Field of Industrial Application" The present invention provides deceleration and stopping to protect mechanisms from collisions that occur when stopping high-speed equipment, and restarting to prevent danger. This invention relates to a speed command circuit equipped with an interlock.

[Prior Art] FIG. 3 shows an example of this type of speed command circuit that has been used in the past. Here, 1 is a stop command manual switch, 2 is a noise filter, 3 is an inverter, 4 is a transistor switch, 5 is a speed setting device using a variable resistor, 6 is a resistor, 7 is a buffer, and 8 is a V/F converter. be.

Here, normally switch 1 is left open and variable resistor 5
A constant voltage VP15 is applied to both ends of , and a desired speed command voltage e1 is taken out as a speed setting output from the speed setting device 5, and is supplied from the buffer 7 to the V/F converter 8 via the resistor 6, where The pulse train Pout obtained in step 1 is supplied to a servo motor (not shown) or the like.

Here, when the stop command input switch 1 is closed, the transistor switch 4 is turned off and the speed command voltage e1 becomes zero instantaneously, so that the pulse train also immediately disappears and the rotating equipment suddenly stops. As a result, an excessive impact force may be applied to the mechanical part of the rotating equipment during a sudden stop, which is undesirable. If you open the door to release the stoppage, the equipment will immediately start rotating at high speed, which is dangerous. Particularly when such equipment is a pulse motor, a step-out phenomenon may occur. A reliable waveform diagram of the above operation is shown in FIG.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks and to
- If you do so, gradually slow down and stop.
When restarting, stop 1 - To prevent the engine from starting by simply operating the command input switch, release the interlock function and restart the engine, so that it gradually accelerates and rotates normally. The object of the present invention is to provide a speed command circuit with a

[Means for Solving the Problem] In order to achieve such an object, the invention sets the rotation speed of the device in a speed command circuit that temporarily stops the rotating device and then restarts the device. means for instructing the device to stop; means for controlling the rotation speed by gradually changing the output from the rotation speed setting means in response to the stop command; and storing the stop command; A means for prohibiting reception of a second stop command while the stop command is stored, and a switch means that operates in conjunction with the rotation speed setting means and in response to the setting of the minimum setting value. , and means for clearing the memory of the stop command in accordance with the operational output of the switch means.

[Function] In the wooden invention, a time constant circuit is set in the voltage circuit of the speed command section.
This allows the stop operation to gradually decelerate and then stop, and by memorizing the stop operation, when restarting, the output of the speed potentiometer will be adjusted regardless of the stop command switch operation. After the voltage e□ is once adjusted to zero, the device is restarted by operating the cell 1 to obtain the desired output voltage e1 again. Therefore, even if you only perform the stop release operation, the system will not restart.

[Example] The wooden invention will be described in detail below with reference to the drawings.

Figure 1 shows an embodiment of the wooden invention, in which 1 is a stop switch, 2.15 is a noise filter, and 9.11.1
2 is a Nant gate, 3 and 10 are inverters, 4 is a transistor switch, 5 is a speed setting device using a variable resistor, 14
is an interlocking switch that is closed in response to bringing the variable resistor 5 to the minimum (zero) state; 6 is a resistor; 13 is a capacitor;
7 is a buffer, 8 is a V/F converter 16 is an initial reset circuit.

The output from the stop switch 1 (rl ``f S l passes through the noise filter 2 and is applied to one side of the Nantes gate 9, and the output from the initial resetting circuit 16 is applied to the other side. The output of the Nandts gate 9 is connected so that the output signal GE can be applied to one input of the Nandts gate 11 via the inverter 10.

Further, the output signal Si4 from the switch 14 for the restart operation passes through the noise filter 15 to the Nantes gate 12.
Connect to be added to human power on one side. Nando game
1-11 and 12 are connected to each other so that the output of 11 is applied to the other human power of 12, and the output of 12 is applied to the other human power of 11, thereby forming a flip-flop circuit.

The output from this flip-flop circuit is the inverter 3
The signal is inputted to the transistor switch 4 via. Further, a capacitor 13 is connected between the connection point between the resistor 6 and the inverter 7 and the ground, and the resistor 6 and the capacitor 13 constitute a time constant circuit.

Next, the operation of the circuit shown in FIG. 1 will be explained with reference to FIG. 2.

First, to explain the case of stop F and operation, when the stop switch 1 is closed, the signal S1 is supplied to the noise filter 2, and the signal CE as shown in FIG. 2 is supplied from the inverter 10 to the Nantes gate 11. 11. Inverter 3 from the output of the flip-flop circuit configured in 12
The output signal co is supplied to the transistor switch 4 through the transistor switch 4, the transistor switch 9 is turned off, and the charge on the capacitor 13 is transferred to the resistor 6. Via the speed setter 5, it is gradually discharged with a specific time constant. C2 has this specific time constant and gradually attenuates without changing abruptly, so the output pulse Pout also does not disappear rapidly.

Therefore, it is possible to avoid suddenly stopping the rotation of the load.

Furthermore, to explain the restart interlock function, when deceleration and stop are applied, that is, the speed setting device attached switch 14 is open, so the stop switch 1
Even if the circuit is opened, the state of the memory (flip-flop) circuit composed of the Nant gates 11 and 12 does not change, and the transistor switch 9 is not turned on, so no pulse output is generated.

To enable restart, adjust the speed setter 5 to zero and close the switch 14 attached to the speed setter to reduce the signal s1.
4 is applied to the noise filter 15, and its output C9 is supplied to the Nant gate 12, which inverts the state of the memory (flip-flop) circuit. Turn on switch 9. Thereafter, by setting the speed setting device 5 from the zero state to the steady state, the motor is restarted and rotated at the normal speed.

[Effects of the Invention] As is clear from the above, according to the present invention, by providing a time constant circuit in the output circuit of the speed setting device, it is possible to prevent excessive impact force from being applied to the mechanical part of the rotating body during a stop operation. It is possible to gradually decelerate and stop. Moreover, since the speed command circuit is provided with an interlock function so that the lock is released and the engine is activated by a restart operation, dangers such as restart due to erroneous operation can be prevented.

In addition, although this embodiment described above has been explained using a V/F converter, it is also possible to use an output voltage whose rising and falling edges do not change rapidly during start and stop as it is as a command output, or to use a phase angle It can also be used by converting it into a control output.

Furthermore, in this embodiment, the operation of the time constant circuit has been described when the engine is stopped, but the time constant circuit is operated in the same way when the engine is started, so that smooth acceleration can be performed even in response to sudden operations.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, and Fig. 2 is a circuit diagram showing an embodiment of the present invention.
FIG. 3 is a circuit diagram showing a conventional example, and FIG. 4 is a signal waveform diagram for explaining the operation of FIG. 1...Stop command manual switch, 2...Noise filter, 3.10...Inverter, 4...l transistor switch, 5...Speed setter using variable resistance, 6...Resistance , 7...Buffer, 8...V/F converter, 9.11.12...Nant gate, 13...Capacitor, 14...Variable resistance of speed setting device 5 to minimum (zero) An interlocking switch that is closed in response to the state, 16... Initial reset circuit.

Claims (1)

[Scope of Claims] A speed command circuit for temporarily stopping a rotating device and then restarting the device, comprising means for setting the rotational speed of the device, means for commanding the stop of the device, and a means for commanding the stop command. means for controlling the rotation speed to gradually decrease by gradually changing the output from the rotation speed setting means in response to the rotation speed setting means; means for prohibiting reception of a stop command; a switch means interlocked with the rotational speed setting means and operated in response to the setting of the minimum setting value; A speed command circuit comprising: means for clearing.