JP4974226B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator that drives a flow rate regulating mechanism that regulates the flow rate of a fluid, such as a rotary valve or a direct acting valve.

  Conventionally, this type of actuator is used by being assembled in a flow rate regulating mechanism such as a flow rate control valve or an air flow rate control damper. In this actuator, the rotational force of the motor is transmitted to the drive shaft via the speed reduction mechanism, thereby increasing the torque and controlling the opening degree of the flow rate regulating mechanism such as a valve or a damper. There are two types of actuators: a type in which a return spring is provided on the drive shaft (spring return type actuator) and a type without a return spring (non-spring return type actuator). In the spring return type actuator, when the power to the actuator is cut off due to a power failure etc., the electromagnetic clutch provided between the motor and the speed reduction mechanism is disconnected, and the drive shaft is forcibly rotated by the return force of the return spring, The flow regulating mechanism is fully closed or fully opened.

  FIG. 8 shows an example of a motor-operated valve provided with a conventional spring return type actuator (for example, see Patent Document 1). In the figure, 1 is a drive shaft, 2 is a return spring attached to the drive shaft 1, 3 is a speed reduction mechanism, 4 is an electromagnetic clutch, 5 is a motor, 6 'is a control unit, and 7 is an operating position of the drive shaft 1. Accordingly, a valve body (flow rate regulating mechanism) that regulates the flow rate of the fluid, and 8 is an opening degree sensor that detects the operating position of the drive shaft 1 as the current opening degree θpv of the valve body 7.

  In the motor-operated valve 100 ′, the control unit 6 ′ operates by receiving a power supply (for example, AC 24 V) and sends a forward rotation command and a reverse rotation command to the motor 5. In addition, the electromagnetic clutch 4 is constantly supplied with power branched to the control unit 6 ′, is in clutch engagement, and the output shaft of the motor 5 is always rotationally coupled to the drive shaft 1 via the speed reduction mechanism 3.

  Thereby, the rotational force of the motor 5 is transmitted to the drive shaft 1 via the electromagnetic clutch 4 and the speed reduction mechanism 3, and the opening degree control of the valve body 7 is performed. In this case, the control unit 6 ′ sends a forward rotation command and a reverse rotation command to the motor 5 so that the current opening degree θpv of the valve body 7 matches the instructed opening degree command value (set opening degree) θsp. When the motor 5 stops after receiving a forward rotation command or a reverse rotation command, the drive shaft 1 maintains the current operating position by the holding torque of the motor 5.

When the power supply to the electric valve 100 ′ is cut off due to a power failure or the like, the power supply to the electromagnetic clutch 4 is also cut off. For this reason, the electromagnetic clutch 4 is disconnected, the torque of the motor 5 is not transmitted to the drive shaft 1, the drive shaft 1 operates in the closing direction or the opening direction by the return force of the return spring 2, and the valve body 7 is forcibly forced. Fully closed (θ0 ) Or fully open (θ100). This function is called a spring return function.

  In the motor-operated valve 100 ′, a phenomenon may occur in which the actual opening θpv does not reach the opening command value θsp even after a predetermined time has elapsed after instructing the set opening. Hereinafter, this phenomenon is referred to as “opening disagreement”. Possible causes of the opening mismatch are “foreign object biting”, “valve sticking”, “motor drive failure”, and the like.

For example, when “foreign matter biting” occurs, it moves halfway, but the actual opening θpv does not reach the opening command value θsp in either the closing direction or the opening direction. Such a phenomenon is referred to as “failure A (first failure)”. Further, when the valve is stuck, the operation becomes impossible and the actual opening θpv does not reach the opening command value θsp in both the closing direction and the opening direction. Such a phenomenon is referred to as “failure B (second failure)”. Failure A and failure B may be caused by motor drive failure .

  For such “opening disagreement”, for example, in Patent Document 2, a case where the valve body is not in the fully closed position or the fully open position is detected as abnormal. Further, in Patent Document 3, foreign matter biting in the electric valve is detected by an overtorque detection switch. Further, in Patent Document 4, the opening adjustment operation is urgently stopped after detecting an abnormal operation similar to “opening disagreement”.

JP 2002-174269 A JP 2003-307280 A JP-A-5-106754 Japanese Patent Laid-Open No. 09-159047

  However, in Patent Document 2, only full-closed full-open control can be applied, and an abnormality in the intermediate opening of proportional control cannot be detected. Moreover, in patent document 3, only the abnormality when overtorque arises like biting can be detected. As described above, in Patent Document 2 and Patent Document 3, it is possible to distinguish between the above-described failure A (first failure) and failure B (second failure) only by determining that an abnormal state is not normal. The failure type could not be specified without going to the site. Moreover, as a first-aid treatment from the occurrence of an abnormality to a full-fledged countermeasure, only a uniform emergency treatment can be taken for all abnormalities.

  Further, in Patent Document 4, when an abnormal operation is detected, the opening adjustment operation is urgently stopped. There are various types of abnormalities, and in spite of different desired countermeasures depending on the types of abnormalities, in Patent Document 4, the valve opening is uniformly maintained and the control is stopped. It may interfere with safe control.

  The present invention has been made to solve such a problem, and the object of the present invention is not to diagnose an abnormal state uniformly as an abnormality, but to distinguish and diagnose a failure type. An object of the present invention is to provide an actuator capable of stopping valve opening control while ensuring safety in the case of a serious failure.

In order to achieve such an object, a first invention (invention according to claim 1) includes a flow rate regulating mechanism for regulating the flow rate of fluid, and an actual opening degree detecting means for detecting the actual opening degree of the flow rate regulating mechanism. A control unit for controlling the opening degree of the flow rate regulating mechanism so that the actual opening degree detected by the actual opening degree detecting means coincides with the opening degree command value, and a predetermined opening position at which the flow rate regulating mechanism is set in advance. In the actuator provided with the forced drive means to forcibly reach the control unit, after the elapse of a predetermined time more than the required operation time from the start to the end of the opening degree control of the flow rate regulating mechanism to the opening degree command value, The current actual opening of the flow regulating mechanism is checked as the failure diagnosis operation opening, and if this failure diagnosis operation opening reaches the allowable range of the opening command value, it is diagnosed as normal and the opening command value The opening at the start of opening control is not reached. When the opening difference between the disability diagnosis operation opening exceeds the predetermined opening width, the failure diagnosis operation before state or operating speed does not move before the opening reaches slows down opening command value When the first failure defined as the state where the predetermined time has passed is diagnosed and the predetermined opening width is not exceeded, it is defined as a state in which neither the closed direction nor the open direction is operated from the present time. that a failure diagnosis means for diagnosing a second failure, the forced failure diagnosis means actuates the forced driving means to forcibly reach the flow regulating mechanism in a predetermined opening position when diagnosed second fault drive Means actuating means are provided.

According to the present invention, for example, when the set opening degree θsp is changed, the control unit starts the opening degree control of the flow regulating mechanism to the opening degree command value θspnew instructed to change, and from the start of the opening degree control. After the elapse of a predetermined time TX that is longer than the required operation time (the operation time required to adjust the opening degree θST of the flow restriction mechanism before the change to the opening instruction value θspnew), the current flow restriction mechanism The actual opening θpv is checked as the failure diagnosis operation opening θX. Here, if the failure diagnosis operation opening degree θX has reached the allowable range of the opening degree command value θsp, it is diagnosed as normal. The opening degree difference Δθ (Δθ = | θX−θST |) between the opening degree θST at the start of the opening degree control and the failure diagnosis operation opening degree θX does not reach the allowable range of the opening degree command value θsp. Is defined as a state that does not move before the failure diagnosis operation opening, or a state in which a predetermined time TX has elapsed before the opening speed command value is reached because the operation speed becomes slow. If the predetermined opening width θw is not exceeded, the second failure (defined as a state that does not operate in the closing direction or the opening direction from the present time) Diagnose fault B) .

When diagnosing the second failure (failure B), the control unit activates the forcible drive means and attempts to force the flow rate regulating mechanism to reach a predetermined opening position. For example, a spring return operation is forcibly performed. In the case of the second failure (failure B), the flow restricting mechanism can be forcibly moved to the spring return position by forcibly performing the spring return operation, for example, by crushing foreign matter.

  According to a second invention (invention according to claim 2), in the first invention, the control unit detects that the flow regulating mechanism has been forced to reach the predetermined opening position by the operation of the forced drive means. And means for shutting off the supply of power to the motor that drives the flow rate regulating mechanism. According to the present invention, when the forcible drive means is activated and the flow rate regulating mechanism forcibly reaches the predetermined opening position, the supply of power to the motor that drives the flow rate regulating mechanism is cut off.

  In the present invention, in normal opening control, a failure diagnosis result may be obtained every time the set opening of the flow rate regulating mechanism is changed, or a failure diagnosis command is given from the outside, and the opening at that time is opened. The above-described diagnosis result may be obtained by setting the degree command value to 100% or 0%.

According to the first aspect of the present invention, the current actual opening of the flow restriction mechanism is determined as a failure diagnosis operation after a predetermined time has elapsed from the start to the end of the opening control of the flow restriction mechanism to the opening command value. Check as the opening, and if this failure diagnosis operation opening reaches the allowable range of the opening command value, it is diagnosed as normal, and does not reach the allowable range of the opening command value, and the opening control If the opening difference between the opening at the start of the operation and the failure diagnosis operation opening exceeds a predetermined opening width, the state that does not move before the failure diagnosis operation opening or the operation speed slows down and opens. When the first failure defined as a state in which the predetermined time has elapsed before reaching the degree command value is determined, and the predetermined opening width is not exceeded, the closing direction is opened in the closing direction from the present time. diagnosis of second failure also be defined as a state in which no operation, when a diagnosis of second failure Since the forcible drive means is operated to force the flow rate regulating mechanism to reach a predetermined opening position that is determined in advance, abnormal conditions are not diagnosed uniformly, but the type of failure is defined. Diagnosis can be made separately, and in the case of a serious failure, it is possible to stop the valve opening control after ensuring safety.

  According to the second aspect of the present invention, when the forcible drive means is activated and the flow rate regulation mechanism forcibly reaches the predetermined opening position, the supply of power to the motor that drives the flow rate regulation mechanism is interrupted, and safety is ensured. In addition, the power supply to the motor can be cut off to prevent wasteful consumption of power.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an outline of a motor-operated valve failure diagnosis system including an embodiment of an actuator according to the present invention. In FIG. 8, the same reference numerals as those in FIG. 8 denote the same or equivalent components as those described with reference to FIG.

  In this embodiment, the control unit 6 of the motor-operated valve 100 provided with the actuator is partially different in function from the control unit 6 ′ of the conventional motor-operated valve 100 ′ shown in FIG. Communication function with the remote monitoring device 300 connected in this manner.

  In this embodiment, the normal opening control range of the valve body 7 which is a flow rate regulating mechanism of the motor-operated valve 100 is an opening range from fully closed (θ0) to fully open (θ100), and the fail safe direction is set. The fully-closed direction is set, and the fully-closed position θ0 is the fail-safe position θFS. Further, the fully closed position θ0 is defined as the return operation end position θSR.

  The return operation end position θSR is set at a position lower than the fully closed position θ0, the fully open position θ100 is set as the fail safe position θFS, the fully open position θ100 is set as the return operation end position θSR, or the fully open position θ100 is set. The return operation end point position θSR may be set at a higher position than that.

  In the present embodiment, a limit switch LS1 for detecting the arrival of the valve element 7 at the fail safe position θFS (return operation end position θSR) is provided, and a detection signal of the limit switch LS1 is sent to the control unit 6. Yes. When the fully open position θ100 is set as the return operation end position θSR or the fail safe position θFS, a limit switch (not shown) for detecting that the valve element 7 has reached the fully closed position θ100 is provided.

  FIG. 2 shows an outline of the hardware configuration of the control unit 6 in the motor-operated valve 100. In the figure, 6-1 is a CPU, 6-2 is a RAM, 6-3 is a ROM, 6-4 is an AC / DC converter, 6-5 to 6-8 is an interface, and 6-9 is an EEPROM. This is a writable nonvolatile memory. The AC / DC converter 6-4 receives the power supply (AC 24V) to the electromagnetic clutch 4 and the motor 5 as a branch input, converts this power supply into a DC voltage, and converts the CPU 6-1, RAM 6-2, ROM 6-3, and interface. 6-5 to 6-8 and supplied to the non-volatile memory 6-9.

  The CPU 6-1 operates in accordance with a program stored in the ROM 6-3 while accessing the RAM 6-2 and the nonvolatile memory 6-9, sends a forward rotation command and a reverse rotation command to the motor 5, and turns on the electromagnetic clutch 4. Send commands and OFF commands. The ROM 6-3 stores a failure diagnosis program as a program unique to the present embodiment.

[Embodiment 1]
Hereinafter, a first example (first embodiment) of the failure diagnosis processing operation according to the failure diagnosis program will be described with reference to the flowcharts shown in FIG. 3 and FIG. As a state before entering the failure diagnosis processing operation, the CPU 6-1 sets the electromagnetic clutch 4 in the clutch engaged state and sets the opening degree θpv of the valve body 7 to the set opening degree (previous opening degree command value) θsp. Assume that they match.

  When the set opening degree θsp is changed by a predetermined width or more (YES in step 101 shown in FIG. 3), the CPU 6-1 sets the current opening degree θpv of the valve body 7 as the opening degree θST before the change (step 102). Further, the opening command value θsp instructed to change is set to θspnew (step 103), and the opening of the valve body 7 to the opening command value θspnew is established from the relationship between the opening θST before the change and the opening command value θspnew instructed to change. A predetermined time TX equal to or longer than a required operation time TS from the start to the end of the degree control is determined (step 104). In this example, a predetermined time TX is a time obtained by adding a predetermined time α to a required operation time TS.

  Next, the CPU 6-1 sends a forward rotation command or a reverse rotation command to the motor 5 so that the current opening degree θpv of the valve body 7 is matched with the opening degree command value θspnew (step 105). Thereby, the rotational force of the motor 5 is transmitted to the drive shaft 1 through the electromagnetic clutch 4 and the speed reduction mechanism 3, and the opening degree control of the valve body 7 to the opening degree command value θspnew is started.

  Further, the CPU 6-1 starts measuring the timer simultaneously with the start of the opening degree control to the opening degree command value θspnew of the valve body 7 (step 106). When the timer time TM of the timer exceeds the predetermined time TX determined in step 104 (YES in step 107), that is, the predetermined time TX from the start of the opening control to the opening command value θspnew of the valve body 7. After the passage, the opening degree θpv of the valve body 7 at that time is read as the failure diagnosis operation opening degree θX (step 108).

  Then, it is compared whether the absolute value of the difference between the read failure diagnosis operation opening degree θX and the opening degree command value θspnew is equal to or smaller than an allowable range β in the opening direction and the closing direction around the opening degree command value θspnew (step 109) If this condition is satisfied (YES in step 109, see arrow (1) shown in FIG. 5), “normal” is diagnosed (step 110), and the failure diagnosis process is terminated.

  On the other hand, if the condition of step 109 is not satisfied (NO in step 109), it is compared if the opening command value θspnew is larger than the opening θST before the change (step 111), and if this condition is satisfied (YES in step 111) ), The process proceeds to step 112 to compare whether θspnew−θX exceeds the allowable range β.

  The case where the condition of step 112 is not satisfied (NO in step 112) is a case where the failure diagnosis operation opening degree θX overshoots exceeding the allowable range β in the opening direction centered on the opening degree command value θspnew (see FIG. 5 (see arrow (4) shown in FIG. 5), “overshoot” is diagnosed in distinction from “normal” (step 113), and the failure diagnosis processing is terminated. However, this “overshoot” is caused by inappropriate control parameters, etc., and can be easily restored to “normal” by appropriately adjusting the control parameters. Since the value θspnew has been reached, it is not necessary to treat it as a failure.

  On the other hand, if the condition of step 112 is satisfied, the CPU 6-1 determines “opening disagreement” and proceeds to step 116 described later.

  Going back to step 111, if the condition of step 111 is not satisfied (NO in step 111), the process proceeds to step 114 to compare whether θX−θspnew exceeds the allowable range β.

  The case where the condition of step 114 is not satisfied (NO in step 114) is a case where the failure diagnosis operation opening θX overshoots beyond the allowable range β in the closing direction centered on the opening command value θspnew. Differentiating from “normal”, “overshoot” is diagnosed (step 115), and the failure diagnosis processing is terminated. However, this “overshoot” is caused by inappropriate control parameters, etc., and can be easily restored to “normal” by appropriately adjusting the control parameters. Since the value θspnew has been reached, it is not necessary to treat it as a failure.

  On the other hand, if the condition of step 114 is satisfied, the CPU 6-1 determines “opening disagreement” and proceeds to step 116 described later.

  Note that the causes of the “opening disagreement” may be “foreign object biting”, “valve stuck”, “motor drive failure”, etc., and the types of failure are “failure A (first failure)” and “ Failure B (second failure) ”. In failure A, the valve body 7 moves halfway, but the actual opening θpv does not reach the opening command value θspnew. In failure B, the valve body 7 hardly moves.

  Therefore, in the present embodiment, a predetermined opening width θw for distinguishing between the failure A and the failure B is determined, the opening width θw, the opening θST at the start of the opening control, and the failure diagnosis operation opening By comparing the opening difference Δθ (Δθ = | θX−θST |) with θX (step 116), it is determined whether the state of “opening mismatch” is failure A or failure B. To.

  In this case, if the opening degree difference Δθ exceeds the predetermined opening width θw (YES in step 116, see the arrow (2) shown in FIG. 5), the CPU 6-1 diagnoses “failure A”, and The diagnosis result is notified to the remote monitoring device 300 via the interface 6-8 and the network 200 (step 117).

  On the other hand, if the opening degree difference Δθ does not exceed the predetermined opening width θw (NO in step 116, see the arrow (3) shown in FIG. 5), the CPU 6-1 diagnoses “failure B”, The diagnosis result is notified to the remote monitoring apparatus 300 via the interface 6-8 and the network 200 (step 118).

  As a result, the remote monitoring device 300 side can know the state of “opening degree mismatch” of the motor-operated valve 100 by distinguishing between the failure A and the failure B, and can take measures according to the situation.

[If diagnosed as fault A]
When the CPU 6-1 diagnoses the failure A (YES in step 116), it notifies the remote monitoring device 300 of the diagnosis result (step 117) and sets the failure diagnosis operation opening θX at that time in the direction of the opening command value θspnew. The opening control range of the valve body 7 is changed as a limit value to (step 119 shown in FIG. 4).

  For example, when the opening command value θspnew is a command value in the opening direction, the CPU 6-1 sets the failure diagnosis operation opening θX at that time as a limit value in the opening direction, and starts the failure diagnosis operation from the fully closed position θ0. The opening range up to the degree θX is set as the opening control range of the valve body 7 (see FIG. 6A). When the opening command value θspnew is a command value in the closing direction, the CPU 6-1 sets the failure diagnosis operation opening θX at that time as a limit value in the closing direction, and from the fully open position θ100 to the failure diagnosis operation opening θX. Is set as the opening control range of the valve body 7 (see FIG. 6B).

  When the failure A is diagnosed in both the opening direction and the closing direction, as shown in FIG. 6C, the failure diagnosis operation opening degree θX1 in the opening direction and the failure diagnosis operation opening degree θX2 in the closing direction are The opening control range of the valve body 7 is restricted.

  When the opening degree control range is changed, the CPU 6-1 controls the opening degree of the valve body 7 as usual for the designation of the set opening degree within the opening degree control range. On the other hand, regarding the designation of the set opening outside the opening control range, the power consumption of the motor 5 is suppressed by not operating the valve body 7.

In the present embodiment, there are the following two cases as the state diagnosed as the failure A.
(1) The case does not move at all before the failure diagnosis operation opening θX due to a foreign object and does not reach the opening command value θspnew.
(2) When moving, but the operating speed is slowed down by a foreign object, and the predetermined time TX has passed before the opening command value θspnew is reached.

  In any of the above states (1) and (2), the operating range that can withstand the operation is left, so that an emergency stop or forced fully closed / fully opened operation has not been reached. In the present embodiment, when a failure A is diagnosed, an emergency stop or forced full closing / full opening is not performed immediately, but by changing the opening control range, the remaining operable operating range , Make full use of the ability to maintain the status quo.

  After changing the opening control range, the CPU 6-1 reads out the number of occurrences NA of the failure A from the non-volatile memory 6-9, and increments the number of occurrences NA of the failure A by 1 (step 120). The number NA of occurrences of the failure A that has been updated is updated and held in the nonvolatile memory 6-9 (step 121). In this case, it is assumed that 0 is stored in the nonvolatile memory 6-9 as the number of occurrences NA of the failure A at the factory shipment stage. As a result, the number of occurrences NA of the failure A can be handled quantitatively as maintenance information.

[Failure A elimination operation]
3 and FIG. 4, the failure diagnosis operation opening θX is read after a predetermined time TX has elapsed from the start of the opening control to the opening command value θspnew, and the read failure diagnosis operation opening θX is read. Does not reach the opening command value θspnew (YES in step 112 or YES in step 114), and the opening difference Δθ at that time exceeds a predetermined opening width θw (YES in step 116), a failure occurs. Diagnose A and immediately notify the remote monitoring apparatus 300 of the diagnosis result.

  However, in the case of the failure A, for example, the abnormal state may be eliminated by removing foreign matter. Therefore, as another method, when a failure A is diagnosed, it is conceivable to try to solve the failure A by once operating in the direction opposite to the control operation direction and again in the control direction.

  For example, as shown by the arrow (0) in FIG. 7, when the failure is diagnosed by the first control operation, the valve body 7 is returned by a certain amount in the direction opposite to the direction to the opening command value θspnew (arrow (1)). Thereafter, the control operation is started again toward the opening command value θspnew. When the failure A is diagnosed again, the valve element 7 is returned by a certain amount in the direction opposite to the direction to the opening command value θspnew (arrow (2)). Such an operation is repeated up to n times.

  Here, when the operation of the valve body 7 in the direction opposite to the direction of the opening command value θspnew is defined as “resolving operation”, the resolving operation time in the maximum n resolving operations (time for operating in the reverse direction) Are settable, and n types of resolution operations are tried according to the situation of the failure A. By this canceling operation, the foreign matter may move or the foreign matter may be crushed, and the failure A may be resolved. When failure A is eliminated by this elimination operation, the effect is recorded in the nonvolatile memory 6-9. When the effect does not appear and the state of the failure A continues, the opening control range of the valve body 7 is changed.

[If diagnosed as failure B]
In the present embodiment , failure B is diagnosed when there is no operation in the closing direction or the opening direction from the present time due to foreign object biting, valve sticking, motor drive inability (disconnection), or the like.

In this case , if the actuator is a spring return type, it may be possible to move the valve body 7 by performing a spring return operation. When the actuator is a non-spring return type, a separate drive device may be prepared and the valve body 7 may be moved by forcibly operating the drive device .

When CPU 6-1 diagnoses failure B (NO in step 116), it notifies the remote monitoring device 300 of the diagnosis result (step 118), and first drives motor 5 in the fail-safe direction (step 122).

By this drive, the motor 5 rotates, the valve body 7 moves, and when the fail safe position θFS is reached, the limit switch LS1 is turned on. In this case, when the limit switch LS1 is turned on (YES in step 123), the CPU 6-1 cuts off the power supply to the motor 5 (step 128). Thereby, the drive of the motor 5 is stopped and the subsequent wasteful consumption of electric power is prevented.

On the other hand, even if the motor 5 is driven in step 122, if the valve body 7 does not move, it is confirmed that the limit switch LS1 is not turned on even after the predetermined time T1 has elapsed (YES in step 124). The electromagnetic clutch 4 is disconnected (step 125). In this case, the actuator is assumed to be a spring return type. Thereby, the torque of the motor 5 is not transmitted to the drive shaft 1, and the spring return operation is started.

The valve body 7 is forcibly moved by this spring return operation, and when the return operation end position θSR (fail safe position θFS) is reached, the limit switch LS1 is turned ON. In this case, when the limit switch LS1 is turned on (YES in step 126), the CPU 6-1 shuts off the power supply to the motor 5 (step 128). Thereby, the drive of the motor 5 is stopped and the subsequent wasteful consumption of electric power is prevented.

  If the limit switch LS1 is not turned on after the predetermined time T2 has elapsed after the start of the spring return operation (YES in step 127), the CPU 6-1 determines that it is difficult to move the valve body 7, and the motor 5 is cut off (step 128). Thereby, the drive of the motor 5 is stopped and the subsequent wasteful consumption of electric power is prevented.

  In this embodiment, the return operation end point position θSR and the fail safe position θFS are the same. However, the return operation end point position θSR and the fail safe position θFS may be different. In this case, the respective positions are detected. A limit switch is provided to perform the same processing operation as described above.

  Further, when a failure A or a failure B is diagnosed, the failure diagnosis operation opening θX and the opening command value θspnew at that time may be recorded in the nonvolatile memory 6-9 in a corresponding manner. As a result, it is possible to grasp the operation direction when diagnosing the failure A and to check the history of the failure A and the failure B.

  In Embodiment 1 described above, failure diagnosis is performed each time the set opening θsp is changed by a predetermined width or more. However, a failure diagnosis command is given from the remote monitoring device 300 to the motor-operated valve 100, and the opening at that time is opened. The failure diagnosis result may be obtained by setting the degree command value to 100% or 0%.

  In Embodiment 1 described above, the time obtained by adding the predetermined time α to the required operation time TS is set as the predetermined time TX. However, the required operation time TS may be set as the predetermined time TX. The maximum operation time required to change the opening of the body 7 from the fully closed position θ0 to the fully open position θ100 may be determined as the predetermined time TX.

  Further, in the first embodiment described above, the electromagnetic clutch 4 is disengaged and the valve body 7 is returned to the return operation end position θSR by the return force of the return spring 2, but not the return force of the return spring 2, For example, the valve body 7 may be returned to the return operation end position θSR by hydraulic pressure or air pressure.

  Further, in the first embodiment described above, the failure diagnosis of the motor-operated valve 100 has been described. However, a hydraulic valve that drives the valve body by hydraulic pressure, a pneumatic valve that drives the valve body by air pressure, a rotary valve, and a direct acting valve It is possible to perform failure diagnosis in the same manner for a wide variety of actuators that drive valve bodies that regulate the flow rate of fluid.

  Moreover, in Embodiment 1 mentioned above, it was set as the structure which connected the motor operated valve 100 with the remote monitoring apparatus 300 via the network 200, However, A display part is provided in the motor operated valve 100, and a failure diagnosis result is displayed on this display part. You may do it.

It is a figure which shows the outline of the electrically operated valve failure diagnostic system containing one Embodiment of the actuator which concerns on this invention. It is a figure which shows the outline of the hardware constitutions of the control part of the motor operated valve in this motor operated valve failure diagnosis system. It is a flowchart which shows the 1st example (Embodiment 1) of the failure diagnosis processing operation according to the failure diagnosis program which the control part of this motor operated valve performs. FIG. 4 is a flowchart showing a failure diagnosis processing operation following FIG. 3. FIG. FIG. 6 is a diagram illustrating a state in which a failure A and a failure B are distinguished and diagnosed in the failure diagnosis processing operation of the first embodiment. It is a figure which shows the example of a change of the opening degree control range at the time of being diagnosed with the failure A. It is a figure explaining failure A cancellation operation at the time of being diagnosed with failure A. It is a figure which shows an example of the conventional motor operated valve.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Drive shaft, 2 ... Return spring, 3 ... Deceleration mechanism, 4 ... Electromagnetic clutch, 5 ... Motor, 6 ... Control part, 6-1 ... CPU, 6-2 ... RAM, 6-3 ... ROM, 6-4 ... AC / DC converter, 6-5-6-8 ... interface, 6-9 ... nonvolatile memory, 7 ... valve, 8 ... opening sensor, 100 ... motor valve, 200 ... network, 300 ... remote Monitoring device.

Claims (2)

A flow rate regulating mechanism that regulates the flow rate of fluid, an actual opening degree detecting unit that detects an actual opening degree of the flow rate regulating mechanism, and an actual opening degree that is detected by the actual opening degree detecting unit is made to coincide with the opening degree command value. In an actuator comprising: a controller for controlling the opening degree of the flow rate regulating mechanism; and a forcible drive means for forcibly reaching the predetermined opening degree position of the flow rate regulating mechanism,
The controller is
After the elapse of a predetermined time longer than the required operation time from the start to the end of the opening control of the flow rate regulating mechanism to the opening command value, the current actual opening of the flow rate regulating mechanism is checked as a failure diagnosis operation opening If the opening position of the failure diagnosis operation is within the allowable range of the opening command value, it is diagnosed as normal, has not reached the allowable range of the opening command value, and If the opening difference between the opening at the start and the failure diagnosis operation opening exceeds a predetermined opening width, the state that does not move or the operation speed becomes slower than the failure diagnosis operation opening. When the first failure defined as the state where the predetermined time has passed before reaching the opening command value is diagnosed and the predetermined opening width is not exceeded, the first opening is also opened in the closing direction from the present time. diagnosis fault diagnoses that second failure, defined as a state that does not work in the direction And means,
Forcibly driving means actuating means for actuating the forcible driving means to forcibly reach the predetermined opening position when the failure diagnosing means diagnoses the second failure. Actuator. The actuator according to claim 1, wherein
The controller is
And means for detecting that the flow restricting mechanism has been forced to reach the predetermined opening position by the operation of the forcible driving means, and shutting off the supply of power to the motor that drives the flow restricting mechanism. An actuator characterized by that.

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