JP2023039605A - relay protection system - Google Patents

Abstract

To provide a relay protection system and a robot arm controller which can shut down the power supply connected to the relay and ensure safety when the relay is used when an abnormality occurs at the relay's contact point.SOLUTION: A relay protection system 10 includes a relay 11, an emergency stop device 13, a trigger detection circuit 15, a sticking detection circuit 17, and a power off circuit 19. The emergency stop device emits an emergency stop signal. The trigger detection circuit is connected to the relay and the emergency stop device to convert the emergency stop signal into a trigger signal. The sticking detection circuit is connected to the trigger detection circuit and the relay, detects a sticking signal from the relay, and issues a power off signal based on the trigger signal and the sticking signal. The power off circuit is connected to the emergency stop device, the relay, and the sticking detection circuit to catch the power off signal, and subsequently cut off the power of the relay based on the power off signal.SELECTED DRAWING: Figure 1

Description

The present invention relates to controllers for electromechanical equipment, and more particularly to relay protection systems.

Relays find wide application in automated control areas such as robot arms, mechanical equipment or other electro-mechanical equipment. However, in the mechanical contacts of the relay, a phenomenon occurs in which the NO contact and the COM contact (common contact) are in a sticking state or stick to each other and cannot be peeled off, depending on factors such as operating temperature and electricity.

A contact failure detection system for a relay disclosed in Patent Document 1 triggers a control system by a control circuit unit to issue a warning and shut off the control system at the same time. Another embodiment of Patent Document 1 cuts off the power controlling the internal low voltage by a protection circuit unit. In summary, Patent Document 1 not only needs to constantly detect the state of the relay, but also adopts a method of controlling and interrupting the internal low voltage transmission when interrupting the operation of the high voltage power supply, so that the internal The transmission paths of low voltage and high voltage sources cannot be cut off independently. Also, when an abnormality occurs in either contact of the two relays, the power to the relay cannot be cut off directly, and a warning is issued to prevent the next activation. was not specifically disclosed.

The power supply control device and the method for detecting an abnormality in the relay disclosed in Patent Document 2 determine the state of the relay based on the charging mechanism of the capacitor.

The relay device disclosed in Patent Document 3 is to perform failure detection and switching control by a control unit arranged inside the relay. However, in Patent Document 3, since the structure of the relay must be redesigned in order to add a control unit, the volume is larger than the volume of a general relay, and it is difficult to deal with a controller that is limited in space.

Taiwan Utility Model No. M472196 China CN101427335 Chinese publication CN109216113A

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a relay protection system capable of shutting off the power supply associated with a relay when an abnormality occurs in the contacts of the relay to ensure safety when using the relay, and its application. The main purpose is to provide a robot arm controller that

To solve the above problems, a relay protection system comprises a relay, an emergency stop device, a trigger detection circuit, a sticking detection circuit and a power off circuit. The emergency stop device emits an emergency stop signal. A trigger detection circuit is connected to the relay and the emergency stop device and converts the emergency stop signal into a trigger signal. The sticking detection circuit is connected to the trigger detection circuit and the relay, detects a sticking signal from the relay, and issues a power off signal based on the trigger signal and the sticking signal. The power-off circuit is connected to the emergency stop device, the relay and the sticking detection circuit, and cuts off power to the relay based on the power-off signal received.

To solve the above problems, the robot arm controller applies a relay protection system.

According to the above-described technical characteristics, the relay protection system according to the present invention and the robot arm to which it is applied operate the sticking detection circuit through the trigger detection circuit based on the emergency stop signal from the emergency stop device, and the sticking phenomenon, That is, the sticking detection circuit determines whether or not an abnormality has occurred. When a sticking phenomenon occurs in the relay, the power off circuit cuts off the power associated with the relay to ensure safety when using the relay. In addition, the emergency stop device can detect whether or not a sticking phenomenon has occurred in the relay, thereby improving the reliability of using the relay.

The detailed structure, features, assembly or method of use of the relay protection system according to the present invention will be made clear through the detailed description of the embodiments below. It should be noted that the following detailed description and the embodiments disclosed by the present invention are merely examples for explaining the present invention, and that the scope of the claims of the present invention cannot be limited. Then you should be able to understand.

1 is a schematic diagram showing construction of a relay protection system according to an embodiment of the present invention; FIG. 1 is a hardware diagram showing a relay protection system according to one embodiment of the present invention; FIG.

A relay protection system according to the present invention will be described below with reference to the drawings. In this specification, terms relating to conduction such as connection and electrical connection and terms relating to power signals or potential signals such as high output and low output do not limit the scope of the claims of the present invention. It is mentioned according to the description of.

(one embodiment)
As shown in FIG. 1, the relay protection system 10 is applied to robot arms or environments where relays are required.

The relay protection system 10 comprises a relay 11 , an emergency stop device 13 , a trigger detection circuit 15 , a sticking detection circuit 17 and a power off circuit 19 . Relay 11 has coil 111 , NO contact 113 , NC contact 115 and COM contact 117 . The emergency stop device 13 issues an emergency stop signal. The trigger detection circuit 15, sticking detection circuit 17 and power off circuit 19 are arranged on a circuit board (not shown in the figure).

A trigger detection circuit 15 is connected to the coil 111 of the relay 11 and the emergency stop device 13 to catch the emergency stop signal. The sticking detection circuit 17 is connected to the trigger detection circuit 15 and the NC contact 115 of the relay 11 and issues a power off signal based on the emergency stop signal and the contact signal of the relay 11 . The power off circuit 19 is connected to the sticking detection circuit 17, the relay 11 and the emergency stop device 13, and cuts off the power of the relay 11 based on the power off signal.

When supplying electricity under normal conditions, the relay 11 supplies power to the load 30 by conducting the NO contact 113 and the COM contact 117 . At this time, the NC contact 115 and the COM contact 117 do not conduct and are cut off.
When the power is cut off under normal conditions, the NC contact 115 and the COM contact 117 of the relay 11 are conductive, and the NO contact 113 and the COM contact 117 are not conductive and cut off. It cannot power a load 30, such as a circuit or motor.

When an abnormality occurs in the relay 11, the NC contact 115 and the COM contact 117 of the relay 11 are brought into conduction. In other words, the NO contact 113 and the COM contact 117 stick to each other and are in a sticking state. Alternatively, since the relay 11 does not conduct the NC contact 115 and the COM contact 117, the power supplied to the load cannot be effectively cut off.

Under abnormal conditions, the present invention detects the content of the emergency stop signal by the trigger detection circuit 15 . At this time, the trigger detection circuit 15 converts the caught emergency stop signal into a trigger signal and then transmits the trigger signal to the sticking detection circuit 17 . A sticking detection circuit 17 detects the contact state of the relay 11 based on the trigger signal.

In this embodiment, the sticking detection circuit 17 detects the operating state of the NC contact 115 . After the emergency stop signal is generated, it is detected that the NC contact 115 and the COM contact 117 are cut off, that is, the NO contacts 113 of the relay are stuck to each other and cannot be peeled off, or are in a sticking state. For example, the sticking detection circuit 17 issues a power off signal to the power off circuit 19 . Subsequently, the power-off circuit 19 cuts off the power of the relay 11 based on the power-off signal, and the maintenance work proceeds.

If the NC contact 115 and the COM contact 117 are connected when the emergency stop signal is generated, the relay 11 is in a normal state.

In this embodiment, the power off circuit 19 has a first switch unit 191 and a second switch unit 193 . The first switch unit 191 is connected to the first power supply VS1 and the emergency stop device 13, and cuts off the power supply to the emergency stop device 13 based on the power off signal. The second switch unit 193 is connected to the second power supply VS2 and the NO contact 113, and cuts off the power supply to the NO contact 113 of the relay 11 based on the power off signal. Due to the above technical features, power off can be achieved by cutting off the power associated with the relay 11 .

If the sticking detection circuit 17 detects that the NC contact 115 and the COM contact 117 are cut off under normal conditions, the sticking state is canceled and the relay 11 returns to its normal state. does not occur.

In FIG. 2, the difference from FIG. 1 is that two relays 11 are arranged. In other words, in other embodiments, the number of relays 11 is not limited to this embodiment and may be increased to three or more.

Emergency stop device 13 has fuse 131 and emergency stop switch unit 133 . The emergency stop device 13 issues an emergency stop signal by operating or activating the emergency stop switch unit 133 . In another embodiment, the emergency stop device 13 can issue the emergency stop signal by another unit or electronic circuit.

The trigger detection circuit 15 has an input protection unit 151, a first operational amplifier OPA1 and a second operational amplifier OPA2. The sticking detection circuit 17 operates based on a trigger signal and has a first N-channel transistor (N-MOSFET) Q1. The power off circuit 19 has a photocoupler 195, a second N-channel transistor Q2, a first P-channel transistor (P-MOSFET) Q3, a second P-channel transistor Q4 and an output protection unit 197. The first switch unit 191 consists of a first P-channel transistor Q3. The second switch unit 193 consists of a second P-channel transistor Q4.

The input protection unit 151 is electrically connected to the output terminal VD of the emergency stop device 13 (ie the emergency stop switch unit 133 of the emergency stop device 13) and the negative phase input end of the first operational amplifier OPA1. The first operational amplifier OPA1 has a positive phase input terminal electrically connected to the first power supply VS1 and an output terminal electrically connected to the negative phase input terminal of the second operational amplifier OPA2. The second operational amplifier OPA2 has a positive input terminal electrically connected to the first power supply VS1 and an output terminal electrically connected to the gate of the first N-channel transistor Q1.
The first N-channel transistor Q1 has a source connected to ground and a drain connected to the NC contact 115 of the relay 11, the first power supply VS1, the gate of the second N-channel transistor Q2 and the first P-channel transistor Q3. is electrically connected to the gate of The source of the second N-channel transistor Q2 is electrically connected to ground. The source of the first P-channel transistor Q3 is electrically connected to the first power supply VS1. The output protection unit 197 is electrically connected to the drain of the first P-channel transistor Q3 and the input of the emergency stop device 13, i.e. the fuse 131 of the emergency stop device 13.
The photocoupler 195 has a primary side electrically connected to the first power supply VS1 and the drain of the second N-channel transistor Q2, and a secondary side electrically connected to the second power supply VS2 and the gate of the second P-channel transistor Q4. The second P-channel transistor Q4 has a source electrically connected to the second power supply VS2 and a drain electrically connected to the NO contact 113 of the relay 11 . The output terminal VD of the emergency stop device 13 is electrically connected to the coil 111 of the relay 11 .

In this embodiment, the input protection unit 151 and the output protection unit 197 are identical in configuration and include diodes and transient voltage diodes. Since the present invention arranges the input protection unit 151 and the output protection unit 197, the wrong wiring of the second power supply VS2 and the first power supply VS1 may cause the power supply system (that is, the power supply environment by the second power supply VS2 and the first power supply VS1). damage can be avoided.

NO contact 113 of relay 11 is connected to COM contact 117 under normal or normal power supply conditions. NC contact 115 allows the load to be powered under open conditions. At this time, if the emergency stop device 13 does not operate or is not activated, the emergency stop device 13 produces a high output at the negative phase input terminal of the first operational amplifier OPA1 and a low output at the output terminal of the first operational amplifier OPA1. output is produced. The output of the second operational amplifier OPA2 is high.
Due to the features of the structure described above, the first N-channel transistor Q1 remains conductive. That is, the first N-channel transistor Q1 conducts between the drain and the source, and the drain has a low output. In contrast, the gates of second N-channel transistor Q2, first P-channel transistor Q3 and second P-channel transistor Q4 are low inputs. If the first N-channel transistor Q2 is turned off and the first P-channel transistor Q3 and the second P-channel transistor Q4 are turned on, the power supply to the relay 11 continues.

When the emergency stop device 13 is activated or activated, the emergency stop device 13 produces a low output at the negative phase input of the first operational amplifier OPA1, a high output at the output of the first operational amplifier OPA1, and a high output at the output of the first operational amplifier OPA1. The output of the two operational amplifier OPA2 is low. At this time, if the first N-channel transistor Q1 is cut off and the NC contact 115 and the COM contact 117 of the relay 11 are connected, that is, if the relay 11 is maintained in a normal state, the first P-channel transistor Q3 and the second P-channel Transistor Q4 becomes conductive and keeps the relay 11 powered.

When the emergency stop device 13 is activated or activated, the emergency stop device 13 produces a low output at the negative phase input of the first operational amplifier OPA1, a high output at the output of the first operational amplifier OPA1, and a high output at the output of the first operational amplifier OPA1. The output of the two operational amplifier OPA2 is low. While the first N-channel transistor Q1 is cut off, the NC contact 115 of the relay 11 is not connected to the COM contact 117, and the NO contact 113 and the COM contact 117 are in a sticking state, that is, the relay 11 has an abnormality. In this case, when a high input is generated at the gates of the first P-channel transistor Q3 and the second N-channel transistor Q2, and the second N-channel transistor Q2 is turned on, the operation of the photocoupler 195 causes the gate of the second P-channel transistor Q4 to A high input occurs. At this time, the first P-channel transistor Q3 and the second P-channel transistor Q4 are not turned on but cut off, cutting off the transmission paths of the second power supply VS2 and the first power supply VS1.

The power-off circuit 19 controls the gate voltage of the second P-channel transistor Q4 through the first power supply VS1 of the optocoupler 195, so that the switching of the first P-channel transistor Q3 and the second P-channel transistor Q4 is synchronized. can be done. Since the first power supply VS1 and the second power supply VS2 are separated by the photocoupler 195, mutual influence can be avoided.

To summarize the above, the relay protection system according to the present invention instructs emergency stop via the emergency stop signal from the emergency stop device, and determines whether the sticking phenomenon, that is, abnormality has occurred in the relay through the trigger detection circuit and the sticking detection circuit. detect whether or not In the event of a relay failure, the power off circuit cuts power associated with all relays. The robot arm controller can de-energize the relays by means of the relay protection system to allow maintenance work on the robot arm or replacement of the relays to be performed. From the above, safety is ensured when using relays. In addition, the emergency stop device can detect whether or not a sticking phenomenon has occurred in the relay, thereby improving the reliability of using the relay.

In this specification, the number and placement positions of operational amplifiers and transistors (N-channel transistors or P-channel transistors) are not limited to those described above, and may be logically changed. In other words, the present invention is by no means limited to the above embodiments, and can be embodied in various forms without departing from the scope of the invention.

10 relay protection system 11 relay 111 coil 113 NO contact 115 NC contact 117 COM contact 13 emergency stop device 131 fuse 133 emergency stop switch unit 15 trigger detection circuit 151 input protection unit 17 sticking detection circuit 19 power off circuit 191 first switch unit 193 Second switch unit 195 Photocoupler 197 Output protection unit 30 Load OPA1 First operational amplifier OPA2 Second operational amplifier Q1 First N-channel transistor
Q2 second N-channel transistor Q3 first P-channel transistor Q4 second P-channel transistor VS1 first power supply VS2 second power supply VD output terminal

Claims (5)

Equipped with relay, emergency stop device, trigger detection circuit, sticking detection circuit and power off circuit,
The emergency stop device emits an emergency stop signal,
the trigger detection circuit is connected to the relay and the emergency stop device and converts the emergency stop signal into a trigger signal;
the sticking detection circuit is connected to the trigger detection circuit and the relay, detects a sticking signal from the relay, and generates a power off signal based on the trigger signal and the sticking signal;
The power-off circuit is connected to the emergency stop device, the relay and the sticking detection circuit to catch the power-off signal, and then cut off the power of the relay based on the power-off signal. ,
Relay protection system. The power off circuit has a first switch unit and a second switch unit, the first switch unit is connected to the emergency stop device and the first power supply, the second switch unit is connected to the NO contact of the relay and the second switch unit. 2. The relay protection according to claim 1, wherein the relay protection circuit is connected to a power supply, and the power-off circuit controls the first switch unit and the second switch unit based on the power-off signal to maintain a cut-off state. system. The power off circuit has a photocoupler and a transistor, the photocoupler has a primary side electrically connected to the first power supply and the transistor of the power off circuit, and a secondary side of the photocoupler to the second power supply and the second switch. 3. A relay protection system according to claim 2, electrically connected to a unit, wherein said power off circuit controls conduction of said transistor of said power off circuit based on said power off signal. The sticking detection circuit has a transistor, the transistor is connected to the NC contact of the relay, the trigger detection circuit and the power off circuit, and is cut off based on the trigger signal, and the sticking detection circuit detects the trigger signal. 4. The relay protection system of claim 3, wherein if not caught, the transistor of the sticking detection circuit is conductive. The trigger detection circuit has a first operational amplifier and a second operational amplifier, wherein the first operational amplifier has a negative phase input terminal electrically connected to the emergency stop device and a positive phase input terminal electrically connected to the first power supply. an output terminal is electrically connected to the negative phase input terminal of the second operational amplifier, the positive phase input terminal of the second operational amplifier is electrically connected to the first power supply, and an output terminal is the sticking detection circuit; 3. The relay protection system according to claim 2, wherein the relay protection system is electrically connected to the .

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