JP7663026B2 - Actuator drive device, solenoid valve device, electromagnetic contactor, and electromagnetic brake device - Google Patents

Description

The present disclosure provides an actuator drive device, an electromagnetic valve device, an electromagnetic contactor, and an electromagnetic brake device.

There are known devices equipped with actuator elements that move a movable element between two predetermined points using magnetic force generated by a current flowing through a coil, such as solenoid valve devices, electromagnetic contactors, and electromagnetic brake devices. Actuator elements can sometimes stop functioning normally due to wear or foreign matter, and it is necessary to automatically determine whether their operation is abnormal.

For example, Patent Document 1 discloses a device that diagnoses signs of failure in an electromagnetic brake device that includes a brake disc, an armature, and an electromagnetic coil. The device in Patent Document 1 detects the current fluctuation component based on the back electromotive force caused by changes in the sliding of the armature, out of the changes in the current flowing through the electromagnetic coil, and observes abnormal sliding of the armature from the current fluctuation component based on the back electromotive force.

Patent No. 6368007

The device of Patent Document 1 measures the number of drops or the current value of the current flowing through the electromagnetic coil in order to observe the sliding abnormality of the armature. In this case, it is necessary to predefine conditions for determining whether an abnormality in the sliding of the armature has occurred according to various numbers of drops and various current values of the current flowing through the electromagnetic coil, which is very time-consuming. Therefore, it is desired to be able to more easily determine abnormalities in the actuator element.

The object of the present disclosure is to provide an actuator drive device that can determine abnormalities in actuator elements more simply and reliably than conventional devices. It is also an object of the present disclosure to provide an electromagnetic valve device, an electromagnetic contactor, and an electromagnetic brake device that are equipped with such an actuator drive device.

An actuator driving device according to one aspect of the present disclosure,
an actuator element including a coil and a movable element, the actuator element moving the movable element between two predetermined points by a magnetic force generated by a current flowing through the coil;
a current detector that measures a first current waveform signal that indicates a change over time of a current flowing through the coil;
a storage device that prestores a second current waveform signal that indicates a change over time in a current flowing through the coil when the actuator element is operating normally;
a comparison circuit for calculating a difference between the first and second current waveform signals;
and a control circuit that outputs a control signal indicating that the actuator element is not operating normally when the absolute value of the difference between the first and second current waveform signals exceeds a predetermined threshold value.

This makes it possible to determine abnormalities in actuator elements more easily and reliably than ever before.

An actuator driving device according to one aspect of the present disclosure,
the current detector measures the first current waveform signal over a predetermined length of time that includes an instant at which a voltage applied to the coil transitions between zero and a non-zero value;
The memory device pre-stores the second current waveform signal measured over the predetermined length of time including the instant at which the voltage applied to the coil transitions between zero and non-zero values when the actuator element is operating normally.

This allows deterioration of the actuator element to be properly detected.

An actuator driving device according to one aspect of the present disclosure,
The device further includes an alarm device that generates a visual or audio alarm signal in response to the control signal.

This allows the user to be notified of any abnormalities in the actuator element.

An actuator driving device according to one aspect of the present disclosure,
the actuator driving device further includes a switch circuit for controlling the supply of current to the coil;
The current detector is integrated into the switch circuit.

This allows the overall size of the device to be reduced.

An electromagnetic valve device according to one aspect of the present disclosure,
The actuator driving device;
and a conduit that is opened and closed by a movable element of the actuator drive.

This makes it easier and more reliable than ever to determine whether an actuator element is abnormal, and also whether an electromagnetic valve device is abnormal.

An electromagnetic contactor according to one aspect of the present disclosure includes:
The actuator driving device;
and at least a pair of contacts that are opened and closed by a movable element of the actuator drive.

This makes it easier and more reliable than ever to determine abnormalities in the actuator element and also in the electromagnetic contactor.

An electromagnetic brake device according to one aspect of the present disclosure includes:
The actuator driving device;
and a brake device actuated by a movable element of the actuator drive device.

This makes it easier and more reliable than ever to determine abnormalities in the actuator element and in the electromagnetic brake device.

According to an actuator driving device according to one aspect of the present disclosure, it is possible to determine an abnormality in an actuator element more simply and reliably than in the past. Furthermore, according to an actuator driving device according to one aspect of the present disclosure, it is possible to provide a solenoid valve device, an electromagnetic contactor, and an electromagnetic brake device that are capable of determining an abnormality in an actuator element more simply and reliably than in the past.

1 is a block diagram showing a configuration of an actuator driving device according to a first embodiment. 2 is a graph showing an example of a voltage applied to a coil 2 in FIG. 1 and a current flowing through the coil 2. 2 is a graph illustrating the operation of the actuator driving device when the actuator element 10 in FIG. 1 is operating normally. 4 is a graph illustrating the operation of the actuator driving device when an abnormality occurs in the actuator element 10 of FIG. 1. FIG. 6 is a schematic diagram showing a part of the configuration of a solenoid valve device 20 according to a second embodiment. FIG. 11 is a schematic diagram showing a part of the configuration of an electromagnetic contactor 30 according to a third embodiment. FIG. 13 is a schematic diagram showing a part of the configuration of an electromagnetic brake device 40 according to a fourth embodiment, and is a cross-sectional view showing a state in which the electromagnetic brake device 40 is in operation. 8 is a cross-sectional view showing a state in which the electromagnetic brake device 40 in FIG. 7 is released. FIG. 13 is a block diagram showing a configuration of an actuator driving device according to a fifth embodiment.

Below, an embodiment of one aspect of the present disclosure will be described with reference to the drawings. In each drawing, the same reference numerals indicate similar components.

[First embodiment]
In the first embodiment, a basic actuator driving device will be described.

[Configuration Example of First Embodiment]
Fig. 1 is a block diagram showing the configuration of an actuator driving device according to the first embodiment. The actuator driving device in Fig. 1 includes an actuator element 10, a current detector 11, a memory device 12, a comparison circuit 13, a control circuit 14, a driving circuit 15, and an alarm device 16.

The actuator element 10 comprises a movable element 1, a coil 2, a spring 3, and a housing 4. At least a portion of the movable element 1 is made of a ferromagnetic material and is held so as to move between two predetermined points (in the example of FIG. 1, the solid line position and the dashed line position). In the example of FIG. 1, the movable element 1 is a rod-shaped plunger. The coil 2 moves the movable element 1 to the solid line position when a current flows through it. In the example of FIG. 1, the coil 2 is a solenoid coil. The spring 3 moves the movable element 1 to the dashed line position when no current flows through the coil 2. The housing 4 accommodates the movable element 1 and the coil 2 inside. As a result, the actuator element 10 moves the movable element 1 between the two predetermined points by a magnetic force generated by a current flowing through the coil 2.

The current detector 11 is connected to the conductor that supplies current to the coil 2 via the current transformer 11a, and measures the current waveform signal I1 that indicates the change over time in the current flowing through the coil 2.

The memory device 12 pre-stores a current waveform signal I0 that indicates the temporal change in the current flowing through the coil 2 when the actuator element 10 is operating normally. In this specification, the current waveform signal I0 pre-stored in the memory device 12 is also referred to as the "reference waveform signal I0."

The comparison circuit 13 calculates the difference between the measured current waveform signal I1 and the reference waveform signal I0.

When the absolute value of the difference between the measured current waveform signal I1 and the reference waveform signal I0 exceeds a predetermined threshold, the control circuit 14 outputs a control signal indicating that the actuator element 10 is not operating normally.

The drive circuit 15 includes a power supply circuit and a switch circuit, and supplies current to the coil 2 under the control of the control circuit 14. The drive circuit 15 stops the operation of the actuator element 10 according to the control signal output from the control circuit 14 if the actuator element 10 is not operating normally.

The alarm device 16 generates a visual or audible alarm signal indicating that the actuator element 10 is not operating normally in accordance with the control signal output from the control circuit 14. This notifies the user of the abnormality in the actuator element 10.

[Operation Example of First Embodiment]
Fig. 2 is a graph showing an example of the voltage applied to the coil 2 and the current flowing through the coil 2 in Fig. 1. The first row in Fig. 2 shows the voltage applied to the coil 2. The second row in Fig. 2 shows the current flowing through the coil 2 when the actuator element 10 is operating correctly. The third row in Fig. 2 shows the current flowing through the coil 2 when an abnormality occurs in the actuator element 10 (for example, when the movable element 1 is fixed in the solid line position or the dashed line position in Fig. 1).

2, a predetermined voltage is applied to coil 2 at time t0 to move movable element 1 from the broken line position to the solid line position in FIG. 1. The current flowing through coil 2 gradually increases after the application of the voltage starts. When movable element 1 is in the broken line position in FIG. 1, coil 2 does not have a core, so its inductance is small. On the other hand, when movable element 1 is in the solid line position in FIG. 1, the magnetic flux of coil 2 passes through movable element 1, so its inductance is large. Therefore, if actuator element 10 operates correctly, as shown in the second row of FIG. 2, the current flowing through coil 2 temporarily decreases when the movement of movable element 1 is completed at time t1 (i.e., when movable element 1 reaches the solid line position in FIG. 1). In contrast, when movable element 1 is fixed in the solid line position or the broken line position in FIG. 1, the current flowing through coil 2 increases monotonically without decreasing, as shown in the third row of FIG. 2.

In this way, by utilizing the characteristics of a solenoid coil, whose inductance changes depending on the position of the movable element 1, the stroke state of the movable element 1 can be monitored based on the current flowing through coil 2.

Fig. 3 is a graph explaining the operation of the actuator driving device when the actuator element 10 of Fig. 1 is operating normally. Fig. 4 is a graph explaining the operation of the actuator driving device when an abnormality occurs in the actuator element 10 of Fig. 1. The first row of Fig. 3 and Fig. 4 shows the voltage applied to the coil 2. The second row of Fig. 3 and Fig. 4 shows the current waveform signal I1 measured by the current detector 11. The third row of Fig. 3 and Fig. 4 shows the inverted signal of the reference waveform signal I0 stored in the memory device 12. The fourth row of Fig. 3 and Fig. 4 shows the difference between the measured current waveform signal I1 and the reference waveform signal I0.

When the actuator element 10 is operating normally, the difference between the measured current waveform signal I1 and the reference waveform signal I0 is approximately zero, as shown in FIG. 3. On the other hand, when an abnormality occurs in the actuator element 10, the absolute value of the difference between the measured current waveform signal I1 and the reference waveform signal I0 becomes a non-zero predetermined value, as shown in FIG. 4. Therefore, the control circuit 14 can determine that the actuator element 10 is not operating normally when the absolute value of the difference between the measured current waveform signal I1 and the reference waveform signal I0 exceeds a predetermined threshold value Th.

The current detector 11 measures the current waveform signal I1 over a predetermined length of time including the instant t11 at which the voltage applied to the coil 2 transitions between zero and a non-zero value. The memory device 12 pre-stores, as a reference waveform signal I0, the current waveform signal measured over a predetermined length of time including the instant t11 at which the voltage applied to the coil 2 transitions between zero and a non-zero value when the actuator element 10 is operating normally. The time period for measuring the current waveform signal I1 or I0 may be set, for example, from t10 to t12, or from t11 to t12.

[Effects of the First Embodiment]
The solenoid element 10 may experience increased sliding resistance, an increased gap between contacts, or abnormal stroke due to wear or foreign matter, etc. According to the actuator driving device of the first embodiment, by calculating the difference between the measured current waveform signal I1 and the reference waveform signal I0, it is possible to determine an abnormality in the actuator element 10 more simply and reliably than in the past.

The characteristic rise in the current flowing through coil 2 described with reference to Figures 2 to 4 can also be observed in any device equipped with an actuator drive device. Therefore, as described in the second to fourth embodiments, the actuator drive device according to the first embodiment can be applied to solenoid valve devices, electromagnetic contactors, electromagnetic brake devices, and the like.

Second Embodiment
In the second embodiment, a solenoid valve device including the actuator drive device according to the first embodiment will be described.

[Configuration Example of Second Embodiment]
Fig. 5 is a schematic diagram showing a part of the configuration of a solenoid valve device 20 according to a second embodiment. The solenoid valve device 20 includes an actuator element 10A shown in Fig. 5 instead of the actuator element 10 in Fig. 1, and further includes a pipe 21. The actuator element 10A includes a movable element 1A, a coil 2, a spring 3, and a housing 4. The solenoid valve device 20 includes a current detector 11, a memory device 12, a comparison circuit 13, a control circuit 14, a drive circuit 15, and an alarm device 16, as in the case of Fig. 1, but these are omitted in Fig. 5. The coil 2 in Fig. 5 is connected to the current detector 11 and the drive circuit 15, as in the case of Fig. 1.

Fluid 24 flows inside conduit 21. Fluid 24 may be a gas such as air, or a liquid such as water. Conduit 21 has a wall 22 with a small opening 23 in part of its flow path to prevent the flow of fluid 24. Movable element 1A is positioned to close opening 23 at the dashed line position in FIG. 5. Coil 2 moves movable element 1A to the solid line position when current is flowing through it. Spring 3 moves movable element 1A to the dashed line position when no current is flowing through coil 2.

In general, in solenoid valve devices, wear of parts or clogging of foreign matter can cause the movable element to be unable to operate within the range and speed of the design values, which can result in an abnormality in the operation of the actuator element and make it impossible to control the flow rate of the flowing fluid to the desired value. According to the solenoid valve device 20 of the second embodiment, as with the actuator driving device of the first embodiment, by calculating the difference between the measured current waveform signal I1 and the reference waveform signal I0, it is possible to determine an abnormality in the actuator element 10A more simply and reliably than in the past.

[Effects of the second embodiment]
According to the solenoid valve device 20 of the second embodiment, by calculating the difference between the measured current waveform signal I1 and the reference waveform signal I0, it is possible to determine an abnormality in the actuator element 10A and also an abnormality in the solenoid valve device 20 more simply and reliably than in the conventional art.

The solenoid valve device 20 according to the second embodiment can be applied to, for example, a cooling device that supplies air or a coolant to a machining device, a welding device, and a control panel. The solenoid valve device 20 according to the second embodiment can also be applied to, for example, a painting device that sprays paint onto an object.

[Third embodiment]
In the third embodiment, an electromagnetic contactor including the actuator driving device according to the first embodiment will be described.

[Configuration Example of the Third Embodiment]
Fig. 6 is a schematic diagram showing a part of the configuration of an electromagnetic contactor 30 according to a third embodiment. The electromagnetic contactor 30 includes an actuator element 10B shown in Fig. 6 instead of the actuator element 10 in Fig. 1, and further includes contacts 31 and 32. The actuator element 10B includes a movable element 1B, a coil 2, a spring 3, and a housing 4. The electromagnetic contactor 30 includes a current detector 11, a storage device 12, a comparison circuit 13, a control circuit 14, a drive circuit 15, and an alarm device 16, as in the case of Fig. 1, but these are omitted in Fig. 6. The coil 2 in Fig. 6 is connected to the current detector 11 and the drive circuit 15, as in the case of Fig. 1.

Contact 31 is fixed to the tip of movable element 1B, and contact 32 is provided at a fixed position relative to the housing 4 of actuator element 10B. Contacts 31 and 32 are connected to an external circuit and are arranged to contact each other when movable element 1B is in the solid line position. Coil 2 moves movable element 1B to the solid line position when current is flowing. Spring 3 moves movable element 1B to the dashed line position when no current is flowing through coil 2.

In general, in electromagnetic contactors, wear of parts or clogging of foreign matter can cause the movable element to be unable to operate within the range and speed of the design values, which can result in abnormal operation of the actuator element and make it impossible to control the on and off as desired. With the electromagnetic contactor 30 according to the third embodiment, as with the actuator driving device according to the first embodiment, it is possible to determine an abnormality in the actuator element 10B more simply and reliably than in the past by calculating the difference between the measured current waveform signal I1 and the reference waveform signal I0.

[Effects of the third embodiment]
According to the electromagnetic contactor 30 of the third embodiment, by calculating the difference between the measured current waveform signal I1 and the reference waveform signal I0, it is possible to determine an abnormality in the actuator element 10B more easily and reliably than in the past, and also to determine an abnormality in the electromagnetic contactor 30.

The electromagnetic contactor 30 according to the third embodiment can be applied to, for example, a belt conveyor. In this case, the electromagnetic contactor 30 can be used to control the on/off of the belt conveyor motor.

[Fourth embodiment]
In the fourth embodiment, an electromagnetic brake device including the actuator drive device according to the first embodiment will be described.

[Configuration Example of Fourth Embodiment]
Fig. 7 is a schematic diagram showing a part of the configuration of an electromagnetic brake device 40 according to a fourth embodiment, and is a cross-sectional view showing a state in which the electromagnetic brake device 40 is in operation. Fig. 8 is a cross-sectional view showing a state in which the electromagnetic brake device 40 of Fig. 7 is released. The electromagnetic brake device 40 includes a movable element 41, a coil 42, a spring 43, a rotating shaft 44, a brake disc 45, a receiving plate 46, a core 47, a substrate 48, and a bolt 49.

The backing plate 46, the core 47, and the substrate 48 are fixed to each other by bolts 49. The movable element 41 is held by the bolts 49 between the backing plate 46 and the core 47 so as to be slidable in the longitudinal direction of the bolts 49. The rotating shaft 44 is rotatably held by the backing plate 46 and the core 47. The brake disc 45 is fixed to the rotating shaft 44 and inserted between the movable element 41 and the backing plate 46. The movable element 41, the coil 42, and the spring 43 correspond to the movable element 1, the coil 2, and the spring 3 in FIG. 1, respectively, and operate in the same manner as the actuator element 10 in FIG. 1.

The electromagnetic brake device 40 includes a current detector 11, a memory device 12, a comparison circuit 13, a control circuit 14, a drive circuit 15, and an alarm device 16, as in the case of FIG. 1, but these are omitted from FIG. 7 and FIG. 8. The coil 42 in FIG. 7 and FIG. 8 is connected to the current detector 11 and the drive circuit 15, as in the case of FIG. 1.

When no current flows through the coil 42, the spring 43 moves the movable element 41 to the position shown in Fig. 7. As a result, the movable element 41 urges the brake disc 45 against the backing plate 46, preventing rotation of the rotating shaft 44. On the other hand, when a current flows through the coil 42, the spring 43 moves the movable element 41 to the position shown in Fig. 8. As a result, the brake disc 45 is released between the movable element 41 and the backing plate 46, allowing the rotating shaft 44 to rotate freely.

In this specification, the movable element 41, the brake disc 45, and the receiving plate 46 are collectively referred to as the "brake device."

In general, in electromagnetic brake devices, the movable element may not be able to operate within the range and speed of the design values due to wear of parts or clogging of foreign matter, which may result in an abnormality in the operation of the actuator element and an inability to stop the object as desired. According to the electromagnetic brake device 40 of the fourth embodiment, as with the actuator drive device of the first embodiment, by calculating the difference between the measured current waveform signal I1 and the reference waveform signal I0, it is possible to determine an abnormality in the electromagnetic brake device 40 more simply and reliably than in the past.

[Effects of the Fourth Embodiment]
According to the electromagnetic brake device 40 of the fourth embodiment, by calculating the difference between the measured current waveform signal I1 and the reference waveform signal I0, it is possible to determine an abnormality in the electromagnetic brake device 40 more simply and reliably than in the conventional art.

The electromagnetic brake device 40 according to the fourth embodiment can be applied to devices such as elevators, robot arms, and automated guided vehicles (AGVs). The electromagnetic brake device 40 according to the fourth embodiment may be configured to stop the motors included in these devices.

[Fifth embodiment]
9 is a block diagram showing the configuration of an actuator driving device according to a fifth embodiment of the present invention, which includes a driving circuit 15A instead of the current detector 11 and driving circuit 15 in FIG.

The drive circuit 15A includes a power supply circuit 51 and a switch circuit 52. Under the control of the control circuit 14, the switch circuit 52 selectively supplies the current supplied from the power supply circuit 51 to the coil 2. The switch circuit 52 includes, for example, a solid-state relay. The switch circuit 52 also includes a current detector 53 integrated therein, which measures a current waveform signal I1 that indicates the temporal change in the current flowing through the coil 2. The control circuit 14 acquires the measured current waveform signal I1 from the current detector 53.

[Effects of the Fifth Embodiment]
According to the actuator driving device of the fifth embodiment, the size of the entire device can be reduced more than that of the actuator driving device of the first embodiment by integrating the current detector 53 into the switch circuit 52. Furthermore, according to the actuator driving device of the fifth embodiment, retrofitting of the actuator driving device can be effectively carried out.

[Other Modifications]
Although the embodiment of the present disclosure has been described in detail above, the above description is merely an example of the present disclosure in every respect. It goes without saying that various improvements and modifications can be made without departing from the scope of the present disclosure. For example, the following modifications are possible. In the following, the same reference numerals are used for the same components as in the above embodiment, and the description of the same points as in the above embodiment is omitted as appropriate. The following modifications can be combined as appropriate.

Figures 2 to 4 explain the case where the voltage applied to coil 2 transitions from zero to a non-zero value, but an abnormality in actuator element 10 can also be determined in the same way when the voltage applied to coil 2 transitions from a non-zero value to zero.

In the second embodiment, a solenoid valve device 20 was described that closes the flow path when no current flows through the coil 2 and opens the flow path when current flows through the coil 2. However, the actuator drive device according to the embodiment can also be applied to a solenoid valve device that closes the flow path when current flows through the coil 2 and opens the flow path when no current flows through the coil 2.

In the third embodiment, an electromagnetic contactor 30 is described that is off when no current flows through the coil 2 and is on when current flows through the coil 2, but the actuator driving device according to the embodiment can also be applied to an electromagnetic contactor that is off when current flows through the coil 2 and is on when no current flows through the coil 2.

In the fourth embodiment, an electromagnetic brake device 40 was described that stops the rotation of the rotating shaft 44 when no current flows through the coil 2 and rotates the rotating shaft 44 when current flows through the coil 2. However, the actuator drive device according to the embodiment can also be applied to an electromagnetic brake device that stops the rotation of the rotating shaft 44 when current flows through the coil 2 and rotates the rotating shaft 44 when no current flows through the coil 2.

[summary]
The actuator driving device, the solenoid valve device, the electromagnetic contactor, and the electromagnetic brake device according to each aspect of the present disclosure may be expressed as follows.

An actuator driving device according to one aspect of the present disclosure includes an actuator element 10, a current detector 11, a memory device 12, a comparison circuit 13, and a control circuit 14. The actuator element 10 includes a coil 2 and a movable element 1, and moves the movable element 1 between two predetermined points by a magnetic force generated by a current flowing through the coil 2. The current detector 11 measures a first current waveform signal indicating a temporal change in the current flowing through the coil 2. The memory device 12 prestores a second current waveform signal indicating a temporal change in the current flowing through the coil 2 when the actuator element 10 is operating normally. The comparison circuit 13 calculates the difference between the first and second current waveform signals. The control circuit 14 outputs a control signal indicating that the actuator element 10 is not operating normally when the absolute value of the difference between the first and second current waveform signals exceeds a predetermined threshold value.

In an actuator driving device according to one aspect of the present disclosure, the current detector 11 measures a first current waveform signal over a predetermined length of time including the moment when the voltage applied to the coil 2 transitions between zero and non-zero values. The memory device 12 pre-stores a second current waveform signal measured over a predetermined length of time including the moment when the voltage applied to the coil 2 transitions between zero and non-zero values when the actuator element 10 is operating normally.

The actuator driver according to one aspect of the present disclosure further includes an alarm device 16 that generates a visual or audible alarm signal in accordance with the control signal.

The actuator driving device according to one aspect of the present disclosure further includes a switch circuit 52 that controls the supply of current to the coil 2. In this case, the actuator driving device includes a current detector 53 integrated into the switch circuit 52.

The solenoid valve device according to one aspect of the present disclosure includes the actuator drive device described above and a pipeline 21 that is opened and closed by a movable element 1A of the actuator drive device.

An electromagnetic contactor according to one aspect of the present disclosure includes the actuator driving device described above and at least a pair of contacts 31, 32 that are opened and closed by a movable element 1B of the actuator driving device.

An electromagnetic brake device according to one aspect of the present disclosure includes the actuator drive device described above and a brake device driven by a movable element 41 of the actuator drive device.

An actuator driving device according to one aspect of the present disclosure can be applied to any device equipped with an actuator element. It is possible to determine the deterioration of the device by determining the deterioration of the actuator element, which has the effect of reducing opportunity loss.

Reference Signs List 1, 1A, 1B Movable element 2 Coil 3 Spring 4 Housing 10, 10A, 10B Actuator element 11 Current detector 12 Memory device 13 Comparison circuit 14 Control circuit 15, 15A Drive circuit 16 Alarm device 20 Solenoid valve device 21 Pipe 22 Wall 23 Opening 24 Fluid 30 Electromagnetic contactors 31, 32 Contacts 40 Electromagnetic brake device 41 Movable element 42 Coil 43 Spring 44 Rotating shaft 45 Brake disc 46 Support plate 47 Core 48 Board 49 Bolt 51 Power supply circuit 52 Switch circuit 53 Current detector

Claims (7)

A control device for an actuator element comprising a coil and a movable element, the actuator element moving the movable element between two predetermined points by a magnetic force generated by a current flowing through the coil, the two points including a first point and a second point, the movable element moving to the first point when a current flows through the coil, and the movable element moving to the second point when no current flows through the coil, the control device comprising:
a current detector that measures a first current waveform signal that indicates a change over time of a current flowing through the coil;
a storage device that prestores a second current waveform signal that indicates a change over time in a current flowing through the coil when the actuator element is operating normally;
a comparison circuit that calculates a difference between a current value of the first current waveform signal at a time when the movable element is supposed to reach the first point and a current value of the second current waveform signal when the movable element reaches the first point;
a control circuit which outputs a control signal indicating that the actuator element is not operating normally when the movable element is fixed at the first point or the second point and an absolute value of a difference between a current value of the first current waveform signal at a time when the movable element is supposed to reach the first point and a current value of the second current waveform signal when the movable element reaches the first point exceeds a predetermined threshold value.
Control device. the current detector measures the first current waveform signal over a predetermined length of time that includes an instant at which a voltage applied to the coil transitions between zero and a non-zero value;
the memory device pre-stores the second current waveform signal measured over the predetermined length of time including an instant at which a voltage applied to the coil transitions between zero and a non-zero value when the actuator element is operating normally;
The control device according to claim 1. and an alarm device that generates a visual or audio alarm signal in response to the control signal.
The control device according to claim 1 or 2. The control device further includes a switch circuit that controls the supply of current to the coil,
The current detector is integrated into the switch circuit.
A control device according to one of claims 1 to 3. an actuator element including a coil and a movable element, the actuator element moving the movable element between two predetermined points by a magnetic force generated by a current flowing through the coil;
A control device according to any one of claims 1 to 4;
A conduit that is opened and closed by the movable element.
Solenoid valve device. an actuator element including a coil and a movable element, the actuator element moving the movable element between two predetermined points by a magnetic force generated by a current flowing through the coil;
A control device according to any one of claims 1 to 4;
At least a pair of contacts opened and closed by the movable element.
Electromagnetic contactor. an actuator element including a coil and a movable element, the actuator element moving the movable element between two predetermined points by a magnetic force generated by a current flowing through the coil;
A control device according to any one of claims 1 to 4;
a brake device actuated by the movable element.
Electromagnetic brake device.

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