JPH10292877A - Electric driving device for valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain stable performance for a long period without adding excessive load to a deceleration device and a braking device by providing a delay device in which a motor power source is inputted after the brake actuation of an electromagnetic brake is released in a power source input circuit to an electric motor. SOLUTION: A braking device 3 is provided with a projecting element 37 moving in the vertical direction by synchronizing with the movement of a plunger 32 and a switch 6 for starting motor which is actuated by the projecting element 37. The starting switch 6 interlocks with a relay 8, the contact 81 of the relay 8 is inputted by the actuation of the switch 6 and a motor 1 is revolved and started. Power is not supplied to the motor 1 till the relay 8 is actuated and a starting signal to the motor 1 is inputted after the brake release of the braking device 3 is confirmed by the switch 6. Thus, the input of the starting signal is prevented during the brake actuation and excessive load is not generated in a deceleration device and the motor 1. Therefore, the deceleration device and the braking device are not damaged and opening and closing performance can be held for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric drive for a valve having an electromagnetic brake for regulating the rotation at a predetermined position in an actuator for opening and closing a rotary valve such as a ball valve or a butterfly valve by the rotational force of an electric motor. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, there is a valve actuator provided with an electromagnetic brake shown in FIG. This device controls the rotation of the electric motor 1 by the gears 21, 22, 23, 2 of the reduction gear device 2.
The output shaft 4 is rotated through 4 and 25, and the valve stem of the valve provided at the lower portion is rotationally driven. The electromagnetic brake 3 is connected to the gear 21 so that the output shaft 4 stops at a predetermined rotation position. The brake 3 is interlocked with the electric motor 1 via the gear 21. When a start signal is input to the motor 1, a signal for applying a current is also input to the electromagnetic brake 3, and the plunger 32 is moved to the spring 33 by the magnetic force of the solenoid 31. The brake shoe 34 on the lower surface is
5, the brake shaft 36 becomes free, so that the gear 21 becomes free to release the brake operation, the motor shaft becomes rotatable, and the rotation of the motor 1 starts. When the current to the solenoid 31 of the electromagnetic brake 3 is cut off,
The plunger 32 is pressed down by the spring force of the spring 33, the brake shoe 34 on the lower surface presses the pad 35, and the brake shaft 36 is fixed.
1 rotation is fixed.

The circuit diagram of this actuator is shown in FIG. 5, in which limit switches OLS and SLS are
It operates by rotation of a cam fixed on the upper part of the output shaft 4 which is rotated by the rotation of. The power to the limit switches OLS and SLS is switched by the operation of the select switch. At the select switch position in the fully closed state of the valve in FIG. 5, both the motor 1 and the brake 3 are turned off.
The brake 3 is in a cutoff state. When the select switch is pressed from the fully closed position of FIG. 5 to switch the power, the OLS is input to the limit switch, and the R
The power is supplied to the motor 1 by the input of one contact, and the power is supplied to the brake 3 by the input of the R1 contact of the relay 5, and the operation of the brake is released. The output shaft 4 is rotated by the rotation of the motor 1, the limit switch SLS is input by a cam fixed to the output shaft 4, the rotation is further performed, and the limit switch OLS is turned off at the valve fully open position. As a result of the OLS being cut off, the R1 contact of the relay 5 is cut off, the power of the motor 1 and the brake 3 is turned off, and the brake 3 is put into the operating state. Further, when the select switch is switched to the SLS side as shown in FIG. 5 from this state, the power is turned on to the motor 1 and the brake 3 while the SLS is being input, and the motor 1 is rotated. The OLS is input by the rotation of the motor 1, and the SLS is turned off by the cam at the fully closed position of the valve, so that the power of the motor 1 and the brake 3 is turned off and the rotation is stopped immediately. Thus, the open / close position of the rotary valve connected to the lower portion of the output shaft 4 is regulated at a predetermined rotational position. As another actuator, there is a motor with a brake in which the electric motor 1 and the electromagnetic brake 3 are integrated, and a valve actuator using the motor with a brake is also known.

[0004]

In the above-mentioned conventional actuator, the operation of the electric motor 1 and the electromagnetic brake 3 is performed electrically in conjunction with each other as shown in FIG. First, when the motor 1 is started, since the OLS for switching the select switch to the OLS side of the limit switch is in the input state, the contact R1 of the relay 5 operates to turn on the power to the brake 3 and the motor 1 and release the brake. In contrast to the case where the signal of the motor 1 is directly inputted and the rotation is started, the electromagnetic brake 3 is applied to the internal solenoid 31 and then the plunger 32 is moved up by the mechanical operating speed of the brake 3 against the spring 33. Only 0.005 to 0, one second is slightly delayed. Therefore, when the motor 1 is started, the rotation of the motor 1 is started while the brake is in operation for a short time, and in the former conventional example, an excessive load is applied to the motor 1 and the gear 21 of the reduction gear 2. Further, in the conventional example using the latter motor with a brake,
And an excessive load is applied to the brake device 3 and the brake shoes 34 and the brake pads 35 are worn. Therefore, in any of the above cases, there is a problem that the gears and the brake 3 of the speed reducer 2 are worn out early in a use state in which the opening and closing of the valve are frequently repeated.

Next, when the rotation of the motor 1 is stopped, the contacts R1 and R2 of the relay 5 are cut off by the operation of the limit switches OLS and SLS by the select switch and the cam.
Immediately after the power of the brake 3 is turned off, the rotation restricting operation state is set. However, the rotating motor 1 and the reduction gear device 2 and the valve interlocked with the rotating motor 1 have the rotating inertia force remaining. The brake operates. As a result of the rapid closing in this inertial rotation state, a large load is applied to the gear 21 of the speed reducer 2 and the shoe 34 and the pad 3 of the brake device 3
5 wears out early. This problem is the same even when an electric motor with an electromagnetic brake is used.Brake release and operation delay occurs due to the mechanical operation delay of the electromagnetic brake, and the brake operates with inertial rotation of the motor with the brake. . SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides an electric drive device for a valve that maintains stable performance for a long period of time without applying an excessive load to a speed reducer or a brake device linked to a motor. .

[0006]

SUMMARY OF THE INVENTION The gist of the present invention comprises an electric motor, an electromagnetic brake for regulating rotation in conjunction with the operation of the electric motor, and a reduction gear device for reducing the rotation of the electric motor. An electric drive device that opens and closes a rotary valve with an output shaft of the reduction gear device, wherein a power input circuit to the electric motor is provided with a delay device to which a motor power is input after the brake operation of the electromagnetic brake is released. An electric drive device for a valve. This delay time is suitably within 1 second, preferably within 0 and 5 seconds. Further, the present invention includes an electric motor, an electromagnetic brake that operates to regulate the rotation in conjunction with the operation of the electric motor, and a reduction gear device that reduces the rotation of the electric motor, and rotates with an output shaft of the reduction gear device. An electric drive device for opening and closing a valve, wherein a power supply input circuit of the electric brake is provided with a delay circuit for performing a brake operation of the electromagnetic brake after a power supply of the electric motor is shut off. It is an electric drive device. This delay time is 1
Within seconds is appropriate.

Further, the present invention provides an electric motor, an electromagnetic brake which operates to restrict rotation in conjunction with the operation of the electric motor,
A reduction gear device for reducing the rotation of the electric motor, and an electric drive device for opening and closing a rotary valve with an output shaft of the reduction gear device. And a delay circuit for inputting a motor power supply after the release is provided, and a power supply input circuit of the electric brake is provided with a delay circuit for performing a brake operation of the electromagnetic brake after the power supply of the electric motor is cut off. An electric drive device for a valve characterized by the following. In the above, the delay device may use a timer to turn on the power of the electric motor within one second after the operation of the electromagnetic brake is released. In the above, the delay circuit may use a capacitor or a timer so that the brake operation of the electromagnetic brake is performed within one second after the power of the electric motor is shut off. This delay time is 0,3
A suitable time is about 0 to 9 seconds.

[0008]

According to the present invention, when the electric motor is started, a start signal of the motor is input after the brake of the electromagnetic brake is released by the delay device. Therefore, the motor is started in response to the release of the brake, and the motor is started in a free state in the gears of the reduction gear linked to the brake, so that an excessive load is not applied to the motor, the gears, the brakes, etc. The rotation of the motor is started smoothly. When the motor stops, the delay circuit operates the brake later than the motor stop signal. As a result, the inertial rotation of the motor and gears is reduced, and the brake is activated when the rotation is stopped, and the inertial rotation state of the reduction gear and the motor is not suddenly closed. Rotation is regulated. Therefore, even in a use state in which the opening and closing of the valve is frequently repeated, an excessive load is not applied to the reduction gear and the brake device, and stable opening and closing operation performance can be maintained for a long period of time.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 are main partial circuit diagrams for explaining an embodiment of the present invention, and the same parts as those described in the conventional diagram of FIG. 4 are denoted by the same reference numerals. First, FIG. 1 shows a first embodiment, in which the electric motor 1 is connected to the electromagnetic brake device 3 via the gear 21 of the speed reducer 2 in the same manner as described with reference to FIG. The brake device 3 applies the electric signal to the solenoid 31 so that the plunger 3
2 rises against the spring 33 and the brake shoe 3
The pressing force of the pad 35 of No. 4 is released, and the brake is released so that the brake shaft 36 can rotate freely. When the electric signal to the solenoid 31 stops, the brake shaft 36 is fixed by the pressing force of the spring 33, and the brake operation of the gear 21 is performed.

On the upper part of the brake device 3, there are provided a projection 37 which can move up and down in synchronization with the movement of the plunger 32, and a motor start switch 6 operated by the projection 37.
The start switch 6 is interlocked with a relay 8 provided on a circuit to the motor 1, and when the switch 6 is operated, a contact 81 of the relay 8 is actuated.
Is input, and the motor 1 starts rotating. That is, the power is not turned on to the motor 1 until the relay 8 is operated, and the activation signal is input to the motor 1 after confirming the release of the brake of the brake device 3 by the switch 6. For this reason, the start signal is prevented from being input to the motor 1 during the braking operation due to the delay of the brake device 3 although it is a short time in the related art, so that an excessive load is not applied to the speed reducer 2 and the motor 1. This delay time may be 0 or 1 second.

On the other hand, a DC rectifying circuit bridge for supplying power to the solenoid 31 of the brake 3 and a power supply relay to the capacitor 7 operated by the control circuit A by the relay 5 are provided in the AC power input circuit B for the brake device 3 at all times. 9, a capacitor 7 and a discharge relay 10 for consuming power of the capacitor 7 to turn on and off a circuit to a solenoid 31.
Circuit is provided. The circuit B to the brake solenoid 31 is always in an input state, and when the control circuit A is shut off by a select switch or a limit switch OLS or SLS when stopping the motor, the contact 91 of the relay 9 is shut off and the power to the capacitor 7 is cut off. Cut off. Even if the power of the capacitor 7 is cut off by the relay 9, the stored holding power is supplied to the discharging relay 10. When the discharging relay 10 finishes consuming the holding power of the capacitor 7, the contact of the discharging relay 10 opens and the brake is released. The DC circuit to the solenoid 31 is cut off, and the brake 3 enters the rotation restricting operation state. Therefore, motor 1
Is stopped at the same time as the contact R1 of the relay 5 is performed.
Discharge relay 10 for holding power of capacitor 7 rather than signal
And the contact of the discharge relay 10 is cut off, so that the power cutoff of the brake device 3 is performed later than the power cutoff of the motor 1, and the brake device 3 is stopped in a state where the rotation of the motor 1 and the like due to the inertial force is stopped. Can be activated. For this reason, the rotation can be restricted without causing an excessive load on the reduction gear 2 or the motor 1 due to the sudden closing. This delay time can be freely selected depending on the capacity of the condenser 7. In a normal valve opening / closing actuator, the time until the inertial rotation stops is about 0 to 3 to 0, 9 seconds within 1 second, preferably 0 to 5 to 0 seconds. , About 7 seconds, and the brake operates when the inertia rotation of the motor shaft is almost completed.

FIG. 2 is a main part circuit diagram showing a second embodiment for delaying a motor start signal from a brake signal at the time of start of rotation. In this case, the rotary drive source uses a motor with a brake in which the motor of the embodiment and the electromagnetic brake are integrated.
A motor having a structure in which the rotation shaft of the motor is directly regulated by an electromagnetic brake without being connected via the motor 1 is used. FIG.
, A timer 11 is provided in the rotation start circuit of the motor 1, and the timer relay 11 is operated by an input signal (brake release signal) to the electromagnetic brake 3 by the relay 5 contact R 1, the timer relay contact 12 is input, and the motor 1 starts. On the other hand, the power supply circuit to the electromagnetic brake 3 is the same as that of the first embodiment shown in FIG.
Is input, power is supplied to the solenoid 31 of the brake device 3, and the brake is released. The setting of this timer 10 is 1
The power is turned on to the motor 1 with a delay of 0, 1 to 0, and 3 seconds within the second, which is delayed by the mechanical operation time of the electromagnetic brake device 3.
Further, the delay circuit when the motor 1 is stopped may delay the power cutoff of the brake-equipped motor to the electromagnetic brake by the holding power of the capacitor 7 as in the first embodiment.
Alternatively, as shown in FIG. 3, instead of providing the capacitor 7 and the discharge relay 10 of the first embodiment, the discharge relay 10 is replaced by a timer relay 13,
It is possible to provide a delay circuit in which the rotation restricting operation to the brake 3 is performed when the inertial rotation of the motor stops.
When a timer is used, there is an advantage that a set delay time can be freely selected, and reliability is improved as compared with a capacitor.

[0013]

As described above, according to the present invention, when the electric motor is started, a motor start signal is input after the brake is released by a delay device such as a limit switch or a timer, and after the brake is released. The motor is started. Therefore, the rotation is smoothly started without applying an excessive load to the gears and the motor of the reduction gear. When the electric motor is stopped, the brake is activated later than the power cutoff of the motor by a delay circuit using a capacitor or a timer provided in a power supply circuit of the brake device. Therefore, the brake is operated while the inertial rotation of the motor and the gears is stopped, so that an excessive load caused by suddenly closing the reduction gear and the motor is prevented, and the rotation of the actuator output shaft can be restricted. Therefore, even in a use state in which the valve is frequently opened and closed, an electric drive device that does not damage the reduction gear or the brake device and maintains stable opening and closing performance for a long period of time can be obtained.

[Brief description of the drawings]

FIG. 1 is a main partial circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a partial circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a partial circuit diagram showing a third embodiment of the present invention.

FIG. 4 is a partial sectional view showing a conventional valve opening / closing actuator.

FIG. 5 is a partial circuit diagram of the conventional valve opening / closing actuator of FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Reduction gear 3 Brake device 4 Output shaft 5 Relay 6 Motor start limit switch 7 Capacitor 8 Relay 9 Power supply relay 10 Discharge relay 11, 13 Timer relay 12 Timer contact 31 Solenoid 32 Plunger 33 Spring 34 Brake shoe 35 Brake pad

Claims (5)

[Claims] 1. An electric motor, an electromagnetic brake for controlling rotation of the electric motor in conjunction with the operation of the electric motor, and a reduction gear device for reducing the rotation of the electric motor. An electric drive device for opening and closing a valve, wherein a power input circuit for the electric motor is provided with a delay device for inputting a motor power after the electromagnetic brake is released from a brake operation. apparatus. 2. An electric motor, an electromagnetic brake for restricting rotation of the electric motor in conjunction with the operation of the electric motor, and a reduction gear device for reducing the rotation of the electric motor. An electric drive device for opening and closing a valve, wherein a power supply input circuit of the electric brake is provided with a delay circuit for performing a brake operation of the electromagnetic brake after a power supply of the electric motor is cut off. Electric drive. 3. An electric motor, an electromagnetic brake for restricting rotation of the electric motor in conjunction with the operation of the electric motor, and a reduction gear device for reducing the rotation of the electric motor. In an electric drive device that opens and closes a valve, a power input circuit to the electric motor is provided with a delay device that inputs a motor power after the brake operation of the electromagnetic brake is released, and a power input circuit of the electric brake is provided. And a delay circuit for performing a brake operation of the electromagnetic brake after a power supply of the electric motor is cut off. 4. The valve according to claim 1, wherein the delay device uses a timer to supply power to the electric motor within one second after the operation of the electromagnetic brake is released. For electric drive. 5. The brake circuit of claim 1, wherein the delay circuit uses a capacitor or a timer to perform a brake operation of the electromagnetic brake within one second after power of the electric motor is shut off. An electric drive device for a valve according to the above.