JPS5813282A - Valve operating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to valve actuators and, more particularly, to the control aspects of such valve actuators.

More specifically, it is possible to generate a valve operating torque of 3 o'clock mII) 9 degrees as a typical value even at the smaller end of its operating range, and at the larger end of its operating range. The present invention relates to a relatively large valve actuation device that can generate a valve actuation torque of 9.ml/degree. Such valve actuators have a wide range of uses, for example in the thermal power generation, gas storage and oil storage industries, and also have special uses in ships, sluices, and others. When such actuators are used, the operating speed and torque requirements for which they are designed are critical, as are their auxiliary controls, to ensure safe and reliable operation.

Such valve actuators have an output shaft driven by an electric motor through a gearing arrangement, such as a worm and a worm gear, and the electric motor opens and closes a valve connected in driving relation to the output shaft. The output shaft can be rotated in either direction to rotate. Seven, top;
In order to obtain specific speed and torque envelope characteristics, a constant electric motor and a specific gear ratio must be used and designed into the actuator by the manufacturer, and these characteristics are then determined by its It is not possible to change the actuator without disassembly, so that it is not possible to provide an off-the-shelf actuator that is suitable for valves with an operating range that requires different speed-torque characteristics. I couldn't do it before.

One object of the invention is to provide a valve with an operating range of
The purpose of the present invention is to provide a ready-made actuating device.

According to the invention, there is provided a variable speed electric motor, a speed control circuit for controlling the electric motor speed including a speed control mechanism by means of which the motor speed can be set to various values, and a preset nine torque control circuit. stopping the predistributor when the limit is exceeded; and providing a set value of torque from one or more electrical nocerameters arranged for at least one direction of rotation of the predistributor and related to the torque of the motor; Torque calibration and its torque limit control circuit □ arranged as follows.

, 82□-1, J6#) 1111m11, and torque limit control 111I are provided.

In accordance with the present invention, a variable speed motor and an adjustable torque limit control circuit are provided, the resistance of which can be set to different values.Therefore, a single motor with a suitably high rating is provided; The single gear ratio of the motor shaft and the actuator output shaft can be adapted for use with the valve in its operating range.

Preferably, the actuator motor is of a type whose speed can be adjusted by varying the input voltage to the motor. In this way, the actuator can be varied in a manner that changes the average input voltage and thus the speed of the motor. It may be equipped with an electric motor that is supplied with power from a c-channel power source. The motor may be, for example, a DC motor; The control range for this/cellsized power supply is such that the same range of average input voltage to the motor can be obtained from a wide range of values of the AC supply voltage, and therefore the same speed range. For example, the control may be such that an AC line voltage of any value between 250 and 500 volts to an average DC input of the same range can be obtained without virtually affecting the motor speed-torque characteristics. It's like getting a voltage.

With this control of the operating range for the paddle voltage, the same terminal can be used for both the three-phase power supply and the single-phase power supply, without making any changes to the line internal circuitry in the latter case. It is possible to use any two of the three terminals without need.

If you control the operating range like this, even if one of the three phases is missing when operating on a three-phase power supply, the operation will continue! It is possible to do so.

Normally, the torque limit control is only applied in the closing direction of the valve actuator. Another novelty of the present invention is that the torque limit control is also performed in the opening direction of the valve actuating device, and the torque limit control is automatically set at the same time as the torque limit control in the closing direction. ing.

The opening torque limit must always be greater than the closing torque limit. These two torque limits may differ by a constant ratio over the entire range of torque limits. Alternatively, they may be different in varying proportions. For example, if the closing torque limit is set near the bottom of the torque limit range, the value of the opening torque limit is set near the top of the torque limit range. Yoshi will also have a relatively high value.

The speed control circuit is arranged to automatically reduce the motor speed at predetermined points during travel of either the unidirectional or bidirectional actuator. In this way, the speed is reduced when the valve driven by the actuator is about to be seated.

The invention will now be described by way of example and with particular reference to the accompanying drawings, in which: FIG. ,,',l ,',l,',,',l; In this embodiment, the valve actuating device comprises a variable speed DC motor 1 and a gear box 2, and the output shaft of the gear box is designated as 6. It is connected in driving relationship in the conventional manner with the main shaft of the valve, which is shown in the form of a screw.

The electric motor 1 is supplied with power from a three-phase power supply through a line 4 leading to a motor control unit 5. As will be explained below, the output from the engine 5 is a pulsed (intermittent) DC power supply voltage whose pulse width can be varied to provide a variable average DC input voltage to the motor 1. This DC power supply voltage is supplied to the motor by line 6.

The motor control unit 5 has control inputs 10, 11, 12 and 15. Input 10 is derived from a speed setting potentiometer 15 with a manual regulator 16. In this way, a reference signal ``r set speed'' is supplied to the control unit 5, which reference signal can be rounded to set the desired motor speed to different values by adjusting the l tensionometer 15. Input 11 is motor speed detector unit 17
derived from. 'In this way an input signal representative of the actual speed of the motor is provided for comparison with the r setting mode J signal, and if this comparison indicates a deviation from the set speed, then the average DC input voltage to the motor 1 is varied to compensate for the motor speed. The detector unit 17 is adapted to detect the back emf generated by the motor rotor in successive pulses of the DC power source [by 19*
a and thus generates a signal representative of the motor speed, which signal is supplied to unit 5 via a synchronizing switch in unit 17. Alternatively, the human power 11 may be derived from a tachometer generator 18, as shown in dashed lines in FIG. 1, driven by the electric motor 1.

Input 12 is derived from one of the switches of intermediate switch unit 21 through a "slow close" link 22. Link 22 may be permanently open or permanently closed, depending on the user's wishes. When it's closed,
The link 22 completes the input line 12 to the intermediate switch unit 21 and produces the "slow close" function as explained below, which function does not occur when open.

Two sets of intermediate switches are provided in the unit 21, one set containing the above-mentioned intermediate switches being actuated at a predetermined point near the end of the travel of the valve actuator in the closing direction; The sets are actuated at nine predetermined points during travel of the valve actuator in the opening direction. The actuation of the intermediate switch is carried out by a counter mechanism 2'5, which counter mechanism 23 is driven in the usual way by an electric motor 10 shaft, so that the position of the counter mechanism at any moment,
The point at which the two sets of intermediate switches are actuated can be adjusted by the manual regulator 24, ie the count represents the rotation of the actuator output shaft and therefore the position of the valve.

Assuming that the slow closing link 22 is closed, it controls the unit 5 via the input 12 when the above-mentioned intermediate switch is actuated near the end of the actuator travel in the closing direction. A signal is generated for this purpose. This input signal ignores the "r set speed" signal from the potentiometer 15 and causes the motor of the remaining actuator in the closing direction to rotate at a predetermined low speed.

Input 13 is derived from reversing switch circuit 25 and essentially controls the direction of rotation of motor 1. This reversing switch circuit 25 receives two control inputs through lines 26 and 27. Line 26 is led from the ``keep closed'' unit 28 and line 27 is led from the ``keep open'' unit 29. This r
Closing embroidery holder) 28a Manually actuable "closing"
It has an input [30] from switch 31. rrIR
When the close switch 61 is actuated, the input signal is connected to the close close circuit 28, the reverse switch circuit 25 and the input 15.
is supplied to the control unit 5 via the electric motor *i to rotate the valve actuating device in the closing direction IIC.

This "keep closed" unit 28 maintains the input circuit to the unit 5 even after the "r closed" switch 31 is restored by the operator. Similarly, the Kr open holding unit 29 has an input 11132 from the "r open" switch 33.

Thus, when the r open j switch is momentarily actuated, the IVII control input is supplied to the control unit 5 via the units 29 and 25 and the input 15 to control the motor 1.
Rotate in the direction of opening the valve actuator. To the operator
Even after the "open" switch 66 is restored, the rotation of the electric motor 1 is maintained by the second unit 29.

An interlock connection, indicated by line 54, is provided between the ``keep closed'' unit 28 and the ``keep open'' unit 29 to prevent these units from being activated at the same time. The r-stop switch 35 is connected through 11136 to the r** hold unit 28 and the r-release hold unit 29, and the unit 28 and 2
It is illustrated as being connected to the 90-way line 37. In this way, when the "r-stop" switch 36 is actuated, one of the units 28 and 29, which is then in the active state, is rendered inactive, thereby stopping the electric motor 1.

r Closed Keeping 1 Unit 28 and r Open Keeping” Unit 2
9 each have a further input line 1, 39 and 40 from the limit switch unit 41.

One.

A 2m limit switch is installed in the unit 41,
The first set is actuated in the limit position of the actuating device in the closing direction, and the second group is actuated in the limit position K of the actuating device in the opening direction. The actuation of these limit switches is effected by a one-counter mechanism as well as the intermediate switch of the unit 21.

Adjustment can be made by means of a point manual regulator 42 in which two sets of limit switches are actuated.

Assuming that the ``Keep Closed'' unit 28 is in the operating state 11, when the first set of limit switches is activated, one of these switches will cause the ``Keep Closed'' unit 28 to be in the inactive state. to stop the electric motor 1. Similarly, assuming that the "kr open maintenance" unit 29 is in the operating state, the second
When the limit switches of the set are activated, one of these switches disables the "keep open" unit 29 and stops the motor 1.

Lines 45 and 44 are shown leading from intermediate switch unit 21 and limit switch unit 41. It is used to send a monitoring signal to a remote control station for these welfare valve controllers.

Further inputs to the R-Keep Closed 28 and R-Keep Releasing units 29 are sent from the Dortar Control and Latch unit 46 via connections 51 and 37. The input 47 to the unit 46 provides a constant value of the torque on which the electric motor 1 is acting. A power input 47 is derived from the power line 4 and provides a constant value of the current that the motor 1 is drawing and therefore a measure of the torque that the motor 1 is acting on.

Torque limit control and latching unit 46 receives input from a torque limit membrane system consisting of nine tensile meters 49 and 50, which in this embodiment are coupled together. I have 48. A manual adjuster 52 is provided at the ninth position for simultaneously adjusting the setting states of the I-tension meters 49 and 50.

One of the potentiometers 49 and 50 generates a "torque setting" signal for the closing direction of the valve actuator;
The other tension meter generates a "torque set" signal for the opening direction of the valve actuator. If the motor torque exceeds the l-lux limit set in the closing direction or the opening direction of the valve actuating device, the operating state of the r-closing maintenance unit 28 and the r-opening maintenance unit 28 is rendered inoperative, stopping the electric motor 1.

Another input is applied from the reversing switch unit 25 through the sleeve 53 to the torque limit control and latch unit 46 so that a roaring torque limit can be applied.
An indication of the direction in which the electric motor 1 is rotating is supplied to the encoder 46.

In FIG. 2, the actual relationship between the torque limits of the valve actuation device in the closing direction and in the opening direction is shown graphically. The horizontal axis represents the setting of regulator 52 and the vertical axis represents the actual torque that can be generated by the actuator before the torque limit is reached.

For example, at a selected torque of 654 of the rated torque, the actuator will provide the selected torque of 65 To in the closing direction (point m), but 85 To of the rated torque in the opening direction. Another feature of torque control with is illustrated in FIG. At low torques: 1 torque, it is desirable to provide a ratio greater than the typical value of 100/300, which for small valves is the r-friction required to release the valve from its seat. This is because the ability to overcome adhesion is relatively large even when the valve is large. Therefore, regardless of the setting state of the regulator 52, the opening torque will never fall below the line (Ox, Ox or C).
It was proposed to have an adjustable r cut-off point for the opening torque illustrated by sK. Line Os
, Ox, and especially Os may not be horizontal as shown, but may be inclined.

r Closing torque selection J dunk 54'# is provided, which is K as in the case of the "low speed closing" link 22.

Permanently open or permanently closed, depending on the user's wishes. When the link 54 is closed (or opened, depending on the logic used), the motor 1 is stopped in the closing direction of the valve actuator.
The internal corrugation of the unit 46 is determined by the torque exerted (by the electric motor) and thus by the force with which the valve is pressed onto its valve seat, rather than by the limit switch 41. Connect the circuit to be connected.

When the link 54 is opened, the stopping of the motor 1 is placed under the control of the limit switch.

Since the torque exerted by the motor in the open direction 1411 during starting is likely to exceed the set limits, a slow starting unit 55 is provided in the power supply line 4. This slow start unit 55 is activated to limit current, as explained below.

Another optional feature is the "set rotation" switch 59 which provides an input to the reversing switch unit 25. The "r set rotation" switch 59 reverses the effect of the operation of the "r close" switch 31 and the r open j switch 35. Thus, in one state of the switch 59, actuation of the ``close'' switch '51 rotates the motor 1 in the clockwise direction, and thus actuation of the ``rim release'' switch 33 rotates the motor 1 in the counterclockwise direction Ki1. Turn around. Therefore, in the other state of switch 59, actuation of switch 61 rotates motor 1 in a counterclockwise direction. What the user wants is for the electric motor 1 to rotate in the hour hand rotation direction KWA for closing.
If the user wants the motor 1 to rotate 11 times counterclockwise to the closing round, the switch 59 is set to its one state; Switch 59 is set to the other state. Therefore,
In response to the request, there is no need to change the full display of the "r closed" switch and the "open" switch.

FIG. 3 shows the essential elements of the power supply circuit. The feeder line 4 is connected in the usual manner in a circular manner as shown in FIG.
It consists of 5 phase wiring leading to a 3 phase full liquid rectifier +50 using 61. Output from rectifier @60 is #15 diagram (a) lI
It takes the form indicated by c62. This output may be passed through a filter 63 to produce a smoothed DC output as shown at K64 in FIG. 5(C). The smooth DC output is then sent to a chisel 65 with control inputs 66, 67 and 6B. Chiso Tsuno 65
0 action is shown in Figure 5 (c) K6? The purpose is to generate a round or cellus-like rectangular wave as shown in the figure. The final average DC voltage of the voltage applied to the electric motor 1, marked as K2O in FIG.・
determined by the swiss ratio.

When using this power supply device, the 3-phase input is, for example, 25
During a change in the range Kb9 from 0 volts to 500 volts (phase voltage), the average DC voltage at the motor rotor can be applied and maintained at a maximum value or reduced from this maximum value by means of a speed controller. The control parameters are selected so that the

If one of the phases is missing in a five-phase power supply to a rectifier, the rectifier becomes a single-phase full-wave rectifier), and the voltage waveform is shown in Figure 5 (b) as 71. Take the waveform shown. The resulting smoothed direct current voltage typically drops to about a6 times its previous value, as indicated by K72 in FIG. 5(a). The voltage drop between 1 and 1 is within the range that can be corrected by the chopper circuit:
b) It has been changed as shown in the diagram marked K2S,
The average DC voltage at the motor terminals, marked 70 in FIG. 5(d), is maintained at the same value.

A low voltage source, typically 12 to 24 VDC, for the control circuit shown in FIG. 1 can be obtained from the three-phase compressor/rectifier circuit 81 (FIG. 4). ,
The primary windings of these transformers are star-wired. each"
In order to ensure that the control circuit power is not lost even if one of the phases is defective, the output from the secondary winding is 3 as shown in Figure 4.
After rectification, they are connected in parallel in such a way that the low voltage DC control circuit is maintained even if any of the two input phase wires are in an open circuit state Kfk.

As shown in FIG. 1, torque limit control operates by sensing the total current flowing through the motor □ through line 47, which is suitable for motors with permanent magnet fields. Minutes
It will be appreciated that in the case of an electric motor, the device can be operated by separately connecting the field tool to a power source KII to sense the armature current in the motor.

A slow start unit 55 is provided to limit current surges to the motor 1 when the motor starts rotating. This unit 55 prevents current surges that occur between the time the motor exceeds the limit set by the torque limit control unit 46 and the build-up of the back emf. The unit 55 also serves to slowly accelerate the electric motor 1 from rest, thereby controlling the valve system when the device is used in a regulating system.

The motor control unit) 5 operates to vary the average voltage supplied to the armature and/or field coil of the motor and/or to adjust the mark-to-sweet ratio of the lasing DC power supply.The speed of the motor is The speed is measured by the speed detector 17 and compared to the set speed reference voltage. Deviations in the motor speed due to changes in load change the back emf generated, causing The circuit 5 operates to adjust the motor speed so that it effectively remains at the set point.

The reversing switches 25 may include an electromechanical set of switches or gates or a set of solid state devices arranged to change the polarity of the armature current relative to the polarity of the field.

Units 28 and 29 are internally relays or contactors or equivalent integrated devices) and are provided with a front interlock 34 so that it is impossible for them to be operated together at the same time. This interlook may take an electrical or mechanical form. Each of these units 28 and 29 is configured such that once the closing button 31 or the opening button 33 is actuated,
The motor is arranged to continue rotating until the stop button 35 or limit switch 41 or torque limit control and latch 46 is actuated.

The intermediate switch unit 21 and the limit switch unit 41 are, for example, as described in GB 114I Patent Specification No. 1.005,7.
The device described in No. 61 and operated by a nine-switch mechanism may be used. Alternatively, a signal may be sent from an analog or digital device which describes the rotation of the actuator output shaft and which controls the operation of units 2 and 41. may be fired from the job.

Although the motor 1 has been described as being speed-controlled by changing the average DC input voltage to it, according to the inventive concept of the present invention, a single-phase or multi-phase crocodile conduction motor is used. It is understood that it is not possible to use an enclosure rectifier to convert the applied AC voltage to a DC voltage, and then pass that DC voltage through an inverter to create a variable frequency AC to control the speed of the motor. It will be.

Previously mentioned actuating device KFi several manually operable control devices 16, 22, 24, 31, 55° 55.42.
It will be seen that 52 and 59 are provided.

These control devices are schematically indicated by a dotted line 71 so that the parameters of the actuating device can be adjusted without having to remove the cover by 1 m, for example with a watertight cover or an explosion protection cover. 4, which is located outside the housing.

[Brief explanation of the drawing]

@ Figure 1 is a schematic diagram of the valve actuation device according to the invention, Figure 2 is a graph illustrating the possibility of adjusting the torque limit control in both the opening and closing directions of the valve actuation device, and the fss diagram is a diagram illustrating the possibility of adjusting the torque limit control in both the opening and closing directions of the valve actuation device. FIG. 4 is a schematic diagram of a part of the power supply of FIG. 3, and FIG. is derived and shown in a graph in relation to the rectified AC voltage of the power supply. DESCRIPTION OF SYMBOLS 1...Electric motor, 4...AC power feeder line, 5...Motor control unit, 15...Moderate setting potentiometer, 17...Motor speed detector, 18...-plate needle power generation Machine, 21... Intermediate switch unit, 22...
Low speed closing link, 23... Counter and cam, 25
. . . Reversing switch circuit, 28 . . . Closing maintenance unit, 29. ...Open maintenance unit, 41...Limit switch, 46...Torque limit control and latch unit, 55...Low speed S dynamic ETS F. Three agents: Patent attorney Terumichi Ito

Claims (1)

Claims: (1) a variable speed motor; a rounded speed control circuit for controlling the motor speed, including a speed selector mechanism (through a first adjustment mechanism) that allows the desired motor speed to be set to various values; , as well as a preset torque limit for stopping the front distribution motor when a preset torque limit is exceeded; a torque limit control circuit including a nine-torque detector arranged to provide a measurement of torque from an electrical nocerameter and a rounded second adjustment mechanism for setting the torque limit control circuit to various torque limit values; A valve operating device comprising: (2) The valve actuation system of paragraph (1), wherein the torque sensor is arranged to provide a measurement of torque from a current related to torque flowing through the motor. (3) The valve actuating device according to item (1) or item (2), wherein the speed control circuit is arranged to control the input voltage to the electric motor and thus the speed of the electric motor. (4) A power supply circuit is provided for supplying a pulsed voltage to the motor; The motor speed is controlled by the speed control circuit and is related to the average value of the voltage.
3) The valve actuation device described in item 3). (5) The speed selector mechanism is arranged to provide a ``set speed'' signal and a rounding mechanism is provided for generating an ``actual speed'' signal representative of the actual motor speed, and the speed control circuit is configured to The valve actuating device according to item (4) is arranged to change the average value of the pulsed voltage when the motor speed deviates from a set speed. (61 Power supply @ The Ayu includes a full-wave rectifier that produces a continuous DC voltage from an AC power supply, and the pulsed voltage is derived from the continuous DC voltage.
) The valve actuating device described in item ). (7) The speed control circuit line has a control effect on the A pulse voltage over an operating range, such that the same average DC voltage can be supplied to the motor even for different AC input voltages. The valve operating device according to item (6). (8) The above-mentioned range of control effects on the normalizing voltage can also be operated satisfactorily with a single phase of the same power supply if the actuating device is designed to be operated with a three-phase power supply. The control effect is as follows.
The valve operating device according to item (1). (9) The voltage source for the control circuit of the actuator is derived from a three-phase power supply in such a way that the voltage source is maintained when any one of the phases of the AC power source is absent. A valve actuating device according to any of the preceding clauses and arranged to be operated by a three-phase power supply. - the voltage source for the control circuit of the actuator is such that the secondary windings and their associated rectifiers are connected in parallel so that a DC voltage source is maintained when running without any one of the phases of the AC power source; No. 9, which is a DC voltage source arranged to be generated from a three-phase power supply through a multi-phase transformer installed
Valve actuating device as described in section. ao The torque-related I4 meter is compared with a reference Nora meter in the torque limit control circuit so that the motor is switched off when the torque-related I4 meter value reaches its reference value. Furthermore, the valve actuation device according to any one of the preceding items, wherein the reference parameter is set by the adjustment mechanism. I The torque limit control operates in both directions of motor rotation,
The valve actuating device according to any of the preceding items, wherein the value of the torque limit is greater in the valve opening direction of the actuating device than in the valve closing direction. I. The valve operating device according to item n, wherein the torque limit of the valve operating device in the valve closing direction and the valve opening direction can be set in seven directions simultaneously by the second adjustment mechanism. a◆ The valve operating device according to item (11), wherein the torque limit for opening and closing the valve is adjusted such that the difference between the opening torque limit and the closing torque limit changes when adjustment is performed.Q !9 Regardless of the setting of the second adjustment mechanism, the torque limit for opening the valve is predetermined, and the torque limit for opening the valve is controlled so as not to fall below the 9th value. The valve actuating device according to any one of the preceding paragraphs, wherein the torque limit control is not activated while the electric motor is started. Paragraphs (1) to 3, where the current limiting device is arranged to operate at the start of the motor, preventing the torque limit control from reaching the activated value and disabling the torque limit control. The valve actuation device according to item (c).(l sleep) The 1111 and the second adjustment mechanism are disposed outside a housing that self-adjusts the electric motor, the moderate control circuit, and the torque limit control circuit. The valve operating device according to any of the preceding items.The rotation direction of the electric motor is set by a first switch, and the rotation direction of the electric motor is set by a second switch, and the rotation direction of the electric motor is set by a second switch. The valve actuation device according to any of the preceding paragraphs, wherein the third switch is operable to reverse the action of the switches 111 and mII2 when setting. The speed of the electric motor at nine predetermined positions during travel of the valve operating device is changed to a predetermined lower value, regardless of the setting state of the speed selector mechanism, and the speed of the electric motor at nine predetermined positions during travel of the valve actuator is changed to a predetermined lower value, and the speed of the electric motor is changed to a predetermined lower value, regardless of the setting state of the speed selector mechanism. where it continues to have its predetermined round value until the end of the run,
The valve actuation device according to any of the preceding items.