JPH0781564B2 - Torque detection system for valve drive actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applicable to a water purification plant, a wastewater treatment system, a temperature control system, a continuous carburizing furnace control system, a dam introduction channel, a gas supply facility for city gas, etc. The present invention relates to a torque detection system for a valve drive actuator that operates a valve body that controls the flow of fluid in a flow path.

[Conventional technology]

At present, maintenance of a plurality of actuators in various plants such as water purification plants and power plants is largely a human task. In order to determine whether or not the actuators will operate normally even in an emergency such as an earthquake, a person checks the systems one by one during maintenance.

The actuator inspection operation performed by such an operation will be described with reference to the flowchart shown in FIG. 7. It is determined whether or not the actuator inspection is necessary (step 71), and if it is not necessary, the processing is not performed. If it is finished and needs to be inspected, the labor is distributed according to the maintenance plan (step 72). Next, the actuators are checked one by one (step 73). As a result of the check, it is judged whether or not the operation of the actuator is good (step 74). If the operation of the actuator is good, the process is ended. If the operation is bad, the manufacturer is requested to perform maintenance and inspection ( Step 75).

Further, recently, in a water purification plant, a wastewater treatment plant, etc., it is necessary to maintain and manage a complicated pipe line as one system, and therefore, it is being adapted to a central information system using a computer.

The basic factor of pipeline control is the opening of various valves installed in the pipeline, and as a driving means for controlling the opening of the valves, many types of electric valve drive Actuators are known.

As an example of the valve driving actuator, an analog control signal from the outside is input to the opening control section.
The opening control section outputs a predetermined signal to a plurality of electromagnetic relays, the motor rotates in accordance with the output, and controls the opening of the valve body via the speed reducer. During that time, a signal indicating the state of the speed reducer is fed back to the opening control section via a sensor such as a valve position detector, and the operation of the motor is set to stop when a predetermined valve opening is obtained. ing.

An analog control signal indicating the valve opening is transmitted from the control board. When the signal from the control board is a digital signal, a D / A converter is interposed in the middle of the signal to convert it into an analog signal, which is then input to the opening control section.

[Problems to be solved by the invention]

However, as described above, in the case of manually inspecting the actuator, one person checks each one at the time of maintenance, and the maintenance cost, the accuracy of the maintenance, the ease of maintenance, etc. are expensive, and the maintenance itself Is inaccurate, requires a lot of labor, is difficult, and has a problem.

In addition, the above-described valve drive actuator that has been conventionally used has a simple structure because it has a control mechanism centered on an electromagnetic relay, and it is not possible to operate the valve drive actuator as a single unit. Although there is an advantage that it is easy, on the other hand, because it is a control unit consisting of a combination of limit switch, torque switch, etc. and an electromagnetic relay,
It simply has the function of setting the valve opening in response to a given input signal.

Further, even when trying to quickly adjust the valve opening according to the environment in which the valve drive actuator is placed, all environmental signals are sent to a host computer, that is, a central control unit, which is placed separately outside. It is necessary to control the valve opening degree by receiving a command from it, and since it is transmission and reception by analog control signal, the number of signal lines increases as the number of controls increases, and furthermore, the central control unit If the actuator for driving the valve and the actuator for driving the valve are far apart from each other, a miscellaneous signal may be mixed during signal transmission / reception, resulting in malfunction.

Further, since all the control commands are transmitted from the separate central control unit, the central control unit is stopped even if one of the valve drive actuators is stopped for maintenance of the valve drive actuator. It was necessary, and as a result, all valve driving actuators had to be stopped. Further, since all the relay switches used are mechanical ones, the control unit becomes large, and as a result, the valve driving actuator itself becomes large.

Therefore, an object of the present invention is to solve the above problems, and relates to a torque detection system for a valve drive actuator that drives a valve installed in a flow path, and a central control using a serial data transmission system. A valve driving actuator with a built-in electronic control device that directly connects to a (central information processing system) computer to exchange information and enables distributed processing, in other words, has an arithmetic circuit, that is, an arithmetic controller inside. , Observing the change over time in the load of the torque value of the valve based on the torque value transferred from the valve drive actuator to the external computer, and performing maintenance depending on how much the change in the load exceeds the steady-state load of the valve torque value. Because you can predict when
It is an object of the present invention to provide a torque detection system for a valve drive actuator, which can perform maintenance very easily and accurately and can perform maintenance at low cost.

[Means for solving problems]

The present invention is configured as follows to achieve the above object. That is, the present invention provides a valve drive actuator having a speed reducer section connected to an actuator output shaft for driving a valve installed in a flow path, and a torque detecting mechanism provided in the speed reducer section. An accurate torque of the valve driving actuator is calculated by correcting the torque value detected by the controller according to the valve diameter of the valve and the model of the speed reducer of the speed reducer unit by an arithmetic controller provided in the valve driving actuator. Find the value,
The present invention relates to a torque detection system for a valve driving actuator, wherein a torque value signal of the torque value corrected and calculated by the arithmetic controller is transferred to an external computer.

Further, in the torque detection system for the valve driving actuator, the torques of a plurality of the valve driving actuators are coupled by connecting the one computing controller with the other computing controllers of the respective valve driving actuators by a digital serial line. The value is detected.

[Action]

The present invention is configured as described above and operates as follows. That is, in this torque detection system for a valve drive actuator, a torque detection mechanism is provided in the speed reducer portion of the valve drive actuator, and a torque value is corrected and calculated by the arithmetic controller for the valve drive actuator to perform the valve drive. Since the torque value of the actuator is detected and the torque value signal is data-transferred to the external computer, it is possible to easily detect whether the valve driving actuator is functioning normally by the Tokule value applied to the valve body, that is, the load. It is possible, moreover, by the arithmetic controller, accurately for each of the valve driving actuators
The torque value can be corrected and detected inexpensively and easily.

Moreover, the valve can be directly controlled by the serial data signal (digital signal) of the computer on the side of the central control unit, and the arithmetic controller can change the environment such as the flow rate and the temperature in the vicinity of the installation location of the valve driving actuator. The control associated with (1) can be processed and controlled by the arithmetic circuit in the valve driving actuator without transmitting a signal to the center side, if necessary. Further, in addition to the reduction in size and weight of the valve driving actuator main body, it is possible to perform systematic control of the valve opening degree and the like by a configuration in which the burden on the host computer, that is, the central control unit side is also reduced. Regarding the maintenance of the drive actuator, the torque value detected by the torque detection mechanism can be corrected and calculated for each valve drive actuator by the arithmetic controller, and self-check can be performed. Can be detected through, and the time and effort of maintenance can be greatly improved.

Further, the torque detection system for the valve driving actuator is configured such that the arithmetic controller of each of the valve driving actuators is coupled to one arithmetic controller by a digital serial line, and the torques of the plurality of valve driving actuators are combined. Can also be detected.

〔Example〕

An embodiment of a torque detection system for a valve driving actuator according to the present invention will be described below in detail with reference to the drawings.

In FIG. 1, a valve driving actuator having a built-in electronic control unit according to the present invention is indicated by reference numeral 1 as a whole. A serial data signal from a host computer (central controller) such as a general-purpose computer (not shown) is input to a serial interface unit which is an external data receiving unit, and the arithmetic controller 3 performs predetermined data processing.

The arithmetic controller 3 is shown in FIG.
An output signal from the arithmetic controller 3 is sent to a solid state relay, and the motor 4 rotates a required amount according to the signal and a valve 6 installed in a pipe 8 which is a flow path via a speed reducer 5 is transmitted. The opening of the valve body can be controlled. The valve opening degree, that is, the movement amount by driving the valve 6 is fed back to the arithmetic controller 3 via a sensor 7 such as a valve position detector provided in the speed reducer 5. The sensor 7 such as a valve position detector takes out the position of the valve 6 from the fully closed position to the fully opened position as a mechanism from inside the actuator, and operates by adding a detector.

The torque detection mechanism 2 is provided inside the speed reducer 5. The torque detection mechanism 2 includes a potentiometer attached to an actuator output shaft, that is, a torque detection shaft (that is, one that continuously detects a torque value by a detector whose rotation angle and sensor output value are proportional), a rotary encoder, a differential encoder. Such as a transformer. Generally, for the torque detection mechanism 2, the valve 6
When a load is applied to the worm gear, the worm gear in the reduction gear unit moves in the axial direction, the amount of movement is converted into a rotational movement using the torque switch mechanism, and this is detected by the torque detector.

By the way, as shown in FIG. 2, the absolute value of the torque value, that is, the torque value curve is different depending on the type of the speed reducer incorporated in the actuator, that is, the model of the speed reducer main body, the diameter of each valve, and the like. That is, when the output P of the opening sensor such as a valve position detector is plotted on the horizontal axis and the torque T is plotted on the vertical axis, the torque value curve is a sign depending on the diameter of each valve, the type of reducer, etc.
As shown by a, b, and c, the characteristics, that is, the basic characteristics to be managed are different.

Therefore, the torque value of the sensor 7 such as the valve position detector obtained from the actuator output shaft 22 is A / A of the arithmetic controller 3.
It is fed back to the D converter (analog-digital converter) 17, and then the CPU of the arithmetic controller 3, that is, the arithmetic unit 15 automatically corrects the error of the actuator itself for each reducer main body model based on the torque value to obtain the official torque value. That is, the accurate torque value is output or transferred to the external computer.

This accurate torque value is transferred from the serial input / output of the arithmetic controller 3, that is, the SIO section 14 to a host computer (central control unit) (not shown), that is, an external computer (in other words, the computer) through a digital serial line. . In addition, the display 2 via the parallel input output or PIO20
Displayed in 1. Here, the motor 4, the speed reducer 5,
Mechanical parts such as the valve 6 are the same as those used in a known valve driving actuator, and therefore will not be described in particular. In the one shown in FIG. 1, a flow meter is provided in the pipe line 8, and a signal from the flow meter is fed back to the arithmetic controller 3 via the A / D converter (not shown).

3 and 4 show an example of a system in the case where a plurality of valve driving actuators are present. First, the third
In the example shown in the figure, the valve driving actuators 1A, 1B, 1C for driving the respective valves 6A, 6B, 6C are sequentially connected by the digital serial line 9, and one of the valve driving actuators 1A among them is connected. The data is collected in the arithmetic controller, connected to the general-purpose computer 10 through the digital serial line 11, and is analyzed by the general-purpose computer 10.

In the example shown in FIG. 4, one valve controller is used to manage a plurality of valve driving actuators, and valve driving actuators 1D, 1E, 1F for driving the respective valves 6D, 6E, 6F , Valve drive actuators 1D, 1E,
The arithmetic controller 3A of 1F is placed separately, and the torque value from the torque detection mechanism of the valve driving actuators 1D, 1E, 1F is input to the arithmetic controller 3A, and a plurality of arithmetic controllers 3G of different valve driving actuators ... Are connected by a digital serial line 12, sent to a general-purpose computer 10, and analyzed by the general-purpose computer 10.

Further, regarding the self-diagnosis of the valve driving actuator 1, the system is configured so that a command can be issued from either the actuator side or the general-purpose computer side for analysis processing. Further, regarding the self-diagnosis of the valve driving actuator 1, not only the torque value but also the actuator opening state, the motor operating state, etc. can be output in the same manner as the torque value.

FIG. 5 shows a block diagram of the serial interface unit and the arithmetic controller 3 in FIG. The signal from the central controller is input to the parallel input output or PIO20. Further, various information in the vicinity of the valve driving actuator 1 side is input to an analog-digital converter, that is, an A / D converter 17 (in the example shown in FIG. 1, a signal from the torque detection mechanism 2). These signals are stored in the RAM 19 and the CPU 15 performs a required operation corresponding to a predetermined program in the ROM 16. As a result, while changing the value of the RAM 19, the SIO, that is, the digital serial line from the output port 14. The data is transferred to the central control unit through.

Next, an outline of the operation of the torque detection system for a valve driving actuator according to the present invention will be described with reference to the flow chart shown in FIG.

When the operation of the torque detection system for a valve driving actuator according to the present invention is started, it is first determined whether or not the valve driving actuator 1 needs to be inspected (step 61).
If it is not necessary, the processing is terminated, and if necessary, an inspection command is issued to the valve driving actuator 1 (step 6
2). Based on the command, the valve driving actuator 1 itself, that is, the built-in (in some cases, a separate type) operation controller 3 in the valve driving actuator 1 operates to perform a check operation (step 63). The result is data-transferred as an accurate torque value of the valve driving actuator 1 through a digital serial circuit and analyzed by a host computer such as a general-purpose computer.

Therefore, it is judged whether or not it is within a predetermined normal torque value range (step 64), and in the case of normal or good operation, the process ends, and the operation abnormality of the valve driving actuator 1 or the torque value abnormality. In the case of, an abnormal output is issued (step 64). This abnormal output becomes an abnormal signal and is sent from the SIO 14 of the valve driving actuator to the host computer through the digital serial line (step 66). The abnormal data from the valve driving actuator 1 is recorded (step 67), and depending on the abnormality, the manufacturer is requested to perform maintenance and inspection of the valve driving actuator 1 on site.

〔The invention's effect〕

Since the torque detection system for the valve driving actuator according to the present invention is configured as described above, it has the following effects. That is, in this torque detection system for a valve drive actuator, a torque detection mechanism is provided in the speed reducer portion of the valve drive actuator, and a torque value is corrected and calculated by the arithmetic controller for the valve drive actuator to perform the valve drive. Since the torque value of the actuator is detected and the torque value signal is transferred to the external computer, it is possible to easily detect whether the valve driving actuator is functioning normally by the torque value applied to the valve body. The arithmetic controller can correct and detect the torque value accurately, inexpensively, and easily for each valve driving actuator.

Moreover, the system itself can be made extremely compact by providing a torque detection mechanism in the reduction gear unit, and further, for the valve drive used in various pipeline control systems under a central information processing system using a computer. It can be effectively used as an actuator and can self-check whether or not the valve drive actuator itself is in a normal operation state, and is particularly suitable for maintenance, centralization of information, decentralization of control, etc. Is.

Further, in addition to enabling direct valve control by a serial data signal (digital signal) from a computer of the central control unit, it is necessary to perform control due to environmental changes such as flow rate and temperature near the installation location of the valve drive actuator. In accordance with the above, it becomes possible to process and control by an arithmetic circuit in the valve driving actuator, that is, the arithmetic controller without transmitting a signal to the central side. With the configuration that reduces the load on the device side, it becomes possible to perform systematic control of the valve opening.

In particular, regarding the maintenance of the valve driving actuator, the torque value detected by the torque detecting mechanism can be corrected and calculated for each valve driving actuator by the arithmetic controller, and self-check can be performed. Since the data is transferred to the central control unit through the digital serial line and detected, the time and labor for maintenance of the valve driving actuator can be greatly shortened, the labor can be saved, and the maintenance cost can be greatly reduced.

Further, the valve driving actuator torque detection system detects the torque of a plurality of valve driving actuators by connecting one computing controller to another valve driving actuator computing controller through a digital serial line. It also has the advantage that

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a torque detection system for a valve drive actuator according to the present invention, FIG. 2 is a graph showing a relationship between sensor output and torque of a valve position detector or the like of a reduction gear main body, FIG. FIG. 4 is a block diagram showing an example of a system in the case where the valve driving actuator of the present invention is present in a complex table, and FIG. 4 is a block diagram showing another example of the system in the case where a plurality of valve driving actuators of the present invention are present. 5 is a block diagram showing an example of an arithmetic controller, FIG. 6 is a flow chart showing the operation of the torque detection system for a valve drive actuator according to the present invention, and FIG. 7 is a conventional torque detection system for a valve drive actuator. 3 is a flowchart showing an example of the operation of FIG. 1,1A, 1B, 1C, 1D, 1E, 1F …… Valve drive actuator, 2
...... Torque detection mechanism, 3,3A, 3B …… Computational controller, 4 …… Motor, 5 …… Reducer, 6,6A, 6B, 6C, 6D, 6
E, 6F …… Valve, 7 …… Sensor such as valve position detector, 8 ……
Pipeline, 9,11,12 ... Digital serial line, 1
0 …… General purpose computer, 22 …… Actuator output shaft.

Claims (2)

[Claims] 1. A valve driving actuator having a speed reducer unit connected to an actuator output shaft for driving a valve installed in a flow path, and a torque detecting mechanism provided in the speed reducer unit, wherein the torque detecting mechanism is used. Accurate torque value of the valve driving actuator by correcting and calculating the detected torque value in accordance with the valve diameter of the valve and the model of the speed reducer of the speed reducer unit by an arithmetic controller provided in the valve driving actuator. Is detected and the torque value signal of the accurate torque value corrected and calculated by the operation controller is transferred to an external computer as a data transfer. 2. A torque value of a plurality of the valve driving actuators is detected by connecting one of the valve driving actuators to another of the valve driving actuators by a digital serial line. A torque detection system for a valve drive actuator according to claim 1.