A malfunction monitoring device for relay contacts of a mechanical press

Abstract

The utility model discloses a kind of fault monitoring devices of relay contact for mechanical press, characterized in that including voltage stabilizing module, current sensor, voltage amplification module, voltage comparison module, voltage setting module and alarm output module, voltage stabilizing module is connected in parallel on the winding of measured relay, current sensor is connected in series with the output contact of measured relay, current sensor, voltage amplification module, voltage comparison module and alarm output module are sequentially electrically connected, voltage setting module is electrically connected with voltage comparison module, and current sensor, voltage amplification module, voltage setting module, voltage comparison module and alarm output module are all electrically connected with voltage stabilizing module;Advantages are that the fault monitoring device can carry out online real-time monitoring to the health state of relay contact when relay works, and timely early warning is carried out, to avoid the loss of press caused by sudden damage of relay.

Description

Technical Field

[0001] This utility model relates to the field of relay fault monitoring technology for presses, and in particular to a fault monitoring device for relay contacts in mechanical presses. Background Technology

[0002] Mechanical presses utilize numerous mechanical relays, some of which are extremely critical, such as those controlling the air jet. Damage to these relays can prevent the timely removal of stamping waste or finished products by compressed air, potentially damaging expensive molds. Especially in stamping production lines, the downtime of one mechanical press can halt the entire line, resulting in significant economic losses. Generally, relay contact damage is caused by contact arcing and oxidation, leading to a gradual increase in contact resistance until it reaches a certain value and causes failure. Therefore, monitoring the health status of relay contacts and providing timely warning signals for relays nearing failure is crucial. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a fault monitoring device for relay contacts of a mechanical press, which can monitor the relay contacts online in real time and provide timely warnings when the relay is working.

[0004] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a fault monitoring device for relay contacts of a mechanical press, comprising a voltage stabilizing module, a current sensor, a voltage amplifying module, a voltage comparison module, a voltage setting module, and an alarm output module. The voltage stabilizing module is connected in parallel to the winding of the relay under test. The current sensor is connected in series with the output contact of the relay under test. The current sensor, voltage amplifying module, voltage comparison module, and alarm output module are electrically connected in sequence. The voltage setting module is electrically connected to the voltage comparison module. Furthermore, the current sensor, voltage amplifying module, voltage setting module, voltage comparison module, and alarm output module are all electrically connected to the voltage stabilizing module.

[0005] Furthermore, the voltage regulator module includes a first resistor, a rectifier diode, a Zener diode, a first capacitor, a second capacitor, a third capacitor, a three-terminal voltage regulator integrated chip, and a first terminal block. The three-terminal voltage regulator integrated chip is model 78M05. One end of the first resistor is electrically connected to one terminal block of the first terminal block, and the other end of the first resistor is electrically connected to the anode of the rectifier diode. The cathode of the rectifier diode, one end of the first capacitor, the cathode of the Zener diode, and one end of the second capacitor are connected and then electrically connected to the IN pin of the three-terminal voltage regulator integrated chip. The OUT pin of the three-terminal voltage regulator integrated chip is connected to one end of the third capacitor and then connected to the power supply. The other end of the third capacitor, the GND pin of the three-terminal voltage regulator integrated chip, the other end of the second capacitor, the anode of the Zener diode, the other end of the first capacitor, and the other terminal block of the first terminal block are connected and then grounded. The first terminal block is connected in parallel with the winding of the relay under test.

[0006] Furthermore, the current sensor is model ACS712ELCTR-05B, and it is connected in series with the output contact of the relay under test through the second terminal block. The VCC pin of the current sensor is electrically connected to the power supply, and the GND pin is grounded.

[0007] Furthermore, the voltage amplification module includes a second resistor, a third resistor, a fourth resistor, a fifth resistor, a fourth capacitor, a fifth capacitor, and a first operational amplifier. One end of the second resistor is electrically connected to the OUT pin of the current sensor. The other end of the second resistor, one end of the fifth resistor, and one end of the fifth capacitor are connected and then electrically connected to the inverting input terminal of the first operational amplifier. The other end of the fifth resistor and the other end of the fifth capacitor are connected and then electrically connected to the output terminal of the first operational amplifier. The output terminal of the first operational amplifier is electrically connected to the voltage comparison module. One end of the third resistor, one end of the fourth resistor, and one end of the fourth capacitor are connected and then electrically connected to the non-inverting input terminal of the first operational amplifier. The other end of the third resistor is electrically connected to the power supply. The other end of the fourth resistor and the other end of the fourth capacitor are connected and then grounded.

[0008] Furthermore, the voltage comparison module includes an eighth resistor, a second operational amplifier, and a third operational amplifier. One end of the eighth resistor is electrically connected to the output terminal of the first operational amplifier, and the other end of the eighth resistor is electrically connected to the non-inverting input terminal of the second operational amplifier. The inverting input terminal of the second operational amplifier is electrically connected to the voltage setting module, and the output terminal of the second operational amplifier is electrically connected to the non-inverting input terminal of the third operational amplifier. The inverting input terminal and the output terminal of the third operational amplifier are connected to the alarm output module.

[0009] Furthermore, the voltage setting module includes a sixth resistor, a seventh resistor, a potentiometer, and a sixth capacitor. One end of the seventh resistor is connected to the power supply, and the other end of the seventh resistor is electrically connected to one end of the potentiometer. The other end of the potentiometer is electrically connected to one end of the sixth resistor. The other end of the sixth resistor is connected to one end of the sixth capacitor and then grounded. The other end of the sixth capacitor is connected to the sliding terminal of the potentiometer and then electrically connected to the inverting input terminal of the second operational amplifier.

[0010] Furthermore, the alarm output module includes a twelfth resistor, an indicator light, and an optocoupler. One end of the twelfth resistor is electrically connected to the output terminal of the third operational amplifier, and the other end of the twelfth resistor is electrically connected to the indicator light. The optocoupler is electrically connected to the power supply and the indicator light, respectively.

[0011] Furthermore, the alarm output module also includes a third terminal block, the optocoupler is electrically connected to the third terminal block, and the third terminal block is electrically connected to the existing controller of the press.

[0012] Furthermore, a delay module is connected in series between the voltage comparison module and the alarm output module.

[0013] Furthermore, the delay module includes a ninth resistor, a tenth resistor, an eleventh resistor, a diode, a seventh capacitor, an eighth capacitor, and a fourth operational amplifier. One end of the ninth resistor is connected to the cathode of the diode and then electrically connected to the output terminal of the third operational amplifier. The other end of the ninth resistor, the anode of the diode, and one end of the seventh capacitor are connected and then electrically connected to the inverting input terminal of the fourth operational amplifier. The other end of the seventh capacitor, one end of the tenth resistor, and one end of the eighth capacitor are connected and then grounded. The other end of the tenth resistor, the other end of the eighth capacitor, and one end of the eleventh resistor are connected and then electrically connected to the non-inverting input terminal of the fourth operational amplifier. The other end of the eleventh resistor is connected to a power supply. The output terminal of the fourth operational amplifier is electrically connected to one end of the twelfth resistor.

[0014] Compared with the prior art, the advantage of this utility model is that the fault monitoring device can monitor the health status of the relay contacts online in real time when the relay is working, and provide timely early warning to avoid press losses caused by sudden relay failure. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the present invention; Figure 2 This is a circuit diagram of the voltage regulator module of this utility model; Figure 3 This is a schematic diagram of the circuit connections of the remaining modules of this utility model. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0017] like Figure 1 As shown, a fault monitoring device for relay contacts in a mechanical press includes a voltage stabilizing module, a current sensor U2, a voltage amplifying module 1, a voltage comparison module 2, a voltage setting module 3, and an alarm output module 4. The voltage stabilizing module is connected in parallel to the winding of the relay under test. The current sensor U2 is connected in series with the output contact of the relay under test. The current sensor U2, voltage amplifying module 1, voltage comparison module 2, and alarm output module 4 are electrically connected in sequence. The voltage setting module 3 is electrically connected to the voltage comparison module 2. Furthermore, the current sensor U2, voltage amplifying module 1, voltage setting module 3, voltage comparison module 2, and alarm output module 4 are all electrically connected to the voltage stabilizing module.

[0018] To prevent voltage fluctuations and interference, a delay module 5 is connected in series between the voltage comparison module 2 and the alarm output module 4. This ensures that the signal output by the voltage comparison module 2 is delayed by the delay module 5 before being output to the alarm output module 4, thus avoiding false alarms.

[0019] The most common cause of relay contact damage is increased contact resistance, which leads to a decrease in the current of the entire circuit. However, in a mechanical press, the load of each relay is basically fixed, and the normal current does not change much. Therefore, as long as the current decreases to a certain extent, an alarm signal can be output.

[0020] When the relay is working, the winding is energized, which also energizes the fault monitoring device. The voltage regulator circuit provides a 5V regulated power supply to each module. The load current carried by the output contact of the relay is collected by the current sensor U2, and the current sensor U2 outputs an analog voltage corresponding to the current proportionally. To measure the current more accurately, the voltage signal output by the current sensor U2 is amplified by the voltage amplification module 1 and then output to the voltage comparison module 2. The voltage comparison module 2 compares the voltage signal representing the current magnitude with a preset voltage threshold in the voltage setting module 3. This voltage threshold is greater than the voltage corresponding to the current when the relay contact is damaged. When the relay is normal, the voltage threshold is lower than the output voltage of the voltage amplification module 1, and the voltage comparison module 2 outputs a low level. If the load current decreases, the output voltage of the voltage amplification module 1 decreases accordingly. When the load current decreases to a certain extent, causing the output voltage of the voltage amplification module 1 to fall below the set voltage threshold, the voltage comparison module 2 outputs a high level, and the alarm output module 4 issues an alarm. At this time, the mechanical press can still operate normally and has not yet reached the point where it needs to be stopped immediately. The relay is replaced when the mechanical press is idle. Therefore, this fault monitoring device can play an early warning role.

[0021] like Figure 2 , 3 As shown, the specific circuit structure of the above-mentioned fault monitoring device is as follows: The voltage regulator module includes a first resistor R1, a rectifier diode D1, a Zener diode D2, a first capacitor C1, a second capacitor C2, a third capacitor C3, a three-terminal voltage regulator integrated chip U1, and a first terminal block 6. The three-terminal voltage regulator integrated chip U1 is a 78M05. One end of the first resistor R1 is electrically connected to one terminal of the first terminal block 6, and the other end of the first resistor R1 is electrically connected to the anode of the rectifier diode D1. The cathode of the rectifier diode D1, one end of the first capacitor C1, the cathode of the Zener diode D2, and one end of the second capacitor C2 are connected and then electrically connected to the IN pin of the three-terminal voltage regulator integrated chip U1. The OUT pin of chip U1 is connected to one end of the third capacitor C3 and then to the power supply. The other end of the third capacitor C3, the GND pin of the three-terminal voltage regulator integrated chip U1, the other end of the second capacitor C2, the anode of the Zener diode D2, the other end of the first capacitor C1, and the other terminal of the first terminal 6 are connected to ground, so that the voltage regulator module is connected in parallel with the winding of the relay under test through the first terminal 6. The current sensor U2 is model ACS712ELCTR-05B, and it is connected in series with the output contact of the relay under test through the second terminal 7. The VCC pin of the current sensor U2 is electrically connected to the power supply, and the GND pin is grounded. The voltage amplification module 1 includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a fourth capacitor C4, a fifth capacitor C5, and a first operational amplifier U3. One end of the second resistor R2 is electrically connected to the OUT pin of the current sensor U2. The other end of the second resistor R2, one end of the fifth resistor R5, and one end of the fifth capacitor C5 are connected and then electrically connected to the inverting input terminal of the first operational amplifier U3. The other end of the fifth resistor R5 and the other end of the fifth capacitor C5 are connected and then electrically connected to the output terminal of the first operational amplifier U3. One end of the third resistor R3, one end of the fourth resistor R4, and one end of the fourth capacitor C4 are connected and then connected to the non-inverting input terminal of the first operational amplifier U3. Electrically connected, the other end of the third resistor R3 is electrically connected to the power supply, and the other end of the fourth resistor R4 and the other end of the fourth capacitor C4 are connected to ground; the voltage comparison module 2 includes an eighth resistor R8, a second operational amplifier U4 and a third operational amplifier U5. One end of the eighth resistor R8 is electrically connected to the output terminal of the first operational amplifier U3, and the other end of the eighth resistor R8 is electrically connected to the non-inverting input terminal of the second operational amplifier U4. The inverting input terminal of the second operational amplifier U4 is electrically connected to the voltage setting module 3, and the output terminal of the second operational amplifier U4 is electrically connected to the non-inverting input terminal of the third operational amplifier U5. The inverting input terminal and the output terminal of the third operational amplifier U5 are connected and then electrically connected to the delay module 5; The voltage setting module 3 includes a sixth resistor R6, a seventh resistor R7, a potentiometer RP, and a sixth capacitor C6. One end of the seventh resistor R7 is connected to the power supply, and the other end of the seventh resistor R7 is electrically connected to one end of the potentiometer RP. The other end of the potentiometer RP is electrically connected to one end of the sixth resistor R6. The other end of the sixth resistor R6 is connected to one end of the sixth capacitor C6 and then grounded. The other end of the sixth capacitor C6 is connected to the sliding end of the potentiometer RP and then electrically connected to the inverting input terminal of the second operational amplifier U4. Delay module 5 includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a diode D3, a seventh capacitor C7, an eighth capacitor C8, and a fourth operational amplifier U6. One end of the ninth resistor R9 is connected to the cathode of the diode D3 and then electrically connected to the output terminal of the third operational amplifier U5. The other end of the ninth resistor R9, the anode of the diode D3, and one end of the seventh capacitor C7 are connected and then electrically connected to the inverting input terminal of the fourth operational amplifier U6. The other end of the seventh capacitor C7, one end of the tenth resistor R10, and one end of the eighth capacitor C8 are connected... The circuit is grounded. The other end of the tenth resistor R10, the other end of the eighth capacitor C8, and one end of the eleventh resistor R11 are connected to the non-inverting input of the fourth operational amplifier U6. The other end of the eleventh resistor R11 is connected to the power supply. The alarm output module 4 includes a twelfth resistor R12, an indicator LED, and an optocoupler U7. One end of the twelfth resistor R12 is connected to the output of the fourth operational amplifier U6. The other end of the twelfth resistor R12 is connected to the indicator LED. The optocoupler U7 is connected to both the power supply and the indicator LED.

[0022] Of course, a third terminal 8 can also be connected to the optocoupler U7 of the alarm output module 4 as needed. The third terminal 8 is electrically connected to the existing controller of the press. The signal output by the alarm output module 4 is sent to the controller to control the press to stop and directly replace the relay.

[0023] In the above embodiments, the first operational amplifier U3, the second operational amplifier U4, the third operational amplifier U5, and the fourth operational amplifier U6 are all of the LM324 type.

[0024] The scope of protection of this utility model includes, but is not limited to, the above embodiments. The scope of protection is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art shall fall within the scope of protection of this utility model.

Claims

1. A fault monitoring device for relay contacts in a mechanical press, characterized in that... The device includes a voltage regulator module, a current sensor (U2), a voltage amplifier module, a voltage comparator module, a voltage setting module, and an alarm output module. The voltage regulator module is connected in parallel to the winding of the relay under test. The current sensor (U2) is connected in series with the output contact of the relay under test. The current sensor (U2), the voltage amplifier module, the voltage comparator module, and the alarm output module are electrically connected in sequence. The voltage setting module is electrically connected to the voltage comparator module. Furthermore, the current sensor (U2), the voltage amplifier module, the voltage setting module, the voltage comparator module, and the alarm output module are all electrically connected to the voltage regulator module.

2. The fault monitoring device for relay contacts of a mechanical press as described in claim 1, characterized in that: The voltage regulator module includes a first resistor (R1), a rectifier diode (D1), a Zener diode (D2), a first capacitor (C1), a second capacitor (C2), a third capacitor (C3), a three-terminal voltage regulator integrated chip (U1), and a first terminal block. The three-terminal voltage regulator integrated chip (U1) is a 78M05. One end of the first resistor (R1) is electrically connected to one terminal of the first terminal block, and the other end of the first resistor (R1) is electrically connected to the anode of the rectifier diode (D1). The cathode of the rectifier diode (D1), one end of the first capacitor (C1), and the Zener diode (D2) are connected to the first terminal block. The cathode of the Zener diode (D2) and one end of the second capacitor (C2) are connected to the IN pin of the three-terminal voltage regulator integrated chip (U1). The OUT pin of the three-terminal voltage regulator integrated chip (U1) is connected to one end of the third capacitor (C3) and then connected to the power supply. The other end of the third capacitor (C3), the GND pin of the three-terminal voltage regulator integrated chip (U1), the other end of the second capacitor (C2), the anode of the Zener diode (D2), the other end of the first capacitor (C1), and the other terminal of the first terminal are connected to ground. The first terminal is connected in parallel with the winding of the relay under test.

3. The fault monitoring device for relay contacts of a mechanical press as described in claim 2, characterized in that: The current sensor (U2) is model ACS712ELCTR-05B, and is connected in series with the output contact of the relay under test through the second terminal. The VCC pin of the current sensor (U2) is electrically connected to the power supply, and the GND pin is grounded.

4. The fault monitoring device for relay contacts of a mechanical press as described in claim 3, characterized in that: The voltage amplification module includes a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), a fourth capacitor (C4), a fifth capacitor (C5), and a first operational amplifier (U3). One end of the second resistor (R2) is electrically connected to the OUT pin of the current sensor (U2). The other end of the second resistor (R2), one end of the fifth resistor (R5), and one end of the fifth capacitor (C5) are connected and then electrically connected to the inverting input terminal of the first operational amplifier (U3). The other end of the fifth resistor (R5)... One end of the first operational amplifier (U3) is connected to the output terminal of the first operational amplifier (U3), and the output terminal of the first operational amplifier (U3) is connected to the voltage comparison module. One end of the third resistor (R3), one end of the fourth resistor (R4), and one end of the fourth capacitor (C4) are connected to the non-inverting input terminal of the first operational amplifier (U3). The other end of the third resistor (R3) is connected to the power supply. The other end of the fourth resistor (R4) and the other end of the fourth capacitor (C4) are connected to the ground.

5. The fault monitoring device for relay contacts of a mechanical press as described in claim 4, characterized in that: The voltage comparison module includes an eighth resistor (R8), a second operational amplifier (U4), and a third operational amplifier (U5). One end of the eighth resistor (R8) is electrically connected to the output terminal of the first operational amplifier (U3), and the other end of the eighth resistor (R8) is electrically connected to the non-inverting input terminal of the second operational amplifier (U4). The inverting input terminal of the second operational amplifier (U4) is electrically connected to the voltage setting module. The output terminal of the second operational amplifier (U4) is electrically connected to the non-inverting input terminal of the third operational amplifier (U5). The inverting input terminal and output terminal of the third operational amplifier (U5) are connected to the alarm output module.

6. The fault monitoring device for relay contacts of a mechanical press as described in claim 5, characterized in that: The voltage setting module includes a sixth resistor (R6), a seventh resistor (R7), a potentiometer (RP), and a sixth capacitor (C6). One end of the seventh resistor (R7) is connected to the power supply, and the other end of the seventh resistor (R7) is electrically connected to one end of the potentiometer (RP). The other end of the potentiometer (RP) is electrically connected to one end of the sixth resistor (R6). The other end of the sixth resistor (R6) is connected to one end of the sixth capacitor (C6) and then grounded. The other end of the sixth capacitor (C6) is connected to the sliding terminal of the potentiometer (RP) and then electrically connected to the inverting input terminal of the second operational amplifier (U4).

7. The fault monitoring device for relay contacts of a mechanical press as described in claim 5, characterized in that: The alarm output module includes a twelfth resistor (R12), an indicator light (LED), and an optocoupler (U7). One end of the twelfth resistor (R12) is electrically connected to the output of the third operational amplifier (U5), and the other end of the twelfth resistor (R12) is electrically connected to the indicator light (LED). The optocoupler (U7) is electrically connected to both the power supply and the indicator light (LED).

8. The fault monitoring device for relay contacts of a mechanical press as described in claim 7, characterized in that: The alarm output module also includes a third terminal block, the optocoupler (U7) is electrically connected to the third terminal block, and the third terminal block is electrically connected to the existing controller of the press.

9. The fault monitoring device for relay contacts of a mechanical press as described in claim 7, characterized in that: A delay module is connected in series between the voltage comparison module and the alarm output module.

10. The fault monitoring device for relay contacts of a mechanical press as described in claim 9, characterized in that: The delay module includes a ninth resistor (R9), a tenth resistor (R10), an eleventh resistor (R11), a diode (D3), a seventh capacitor (C7), an eighth capacitor (C8), and a fourth operational amplifier (U6). One end of the ninth resistor (R9) is connected to the cathode of the diode (D3) and then electrically connected to the output terminal of the third operational amplifier (U5). The other end of the ninth resistor (R9), the anode of the diode (D3), and one end of the seventh capacitor (C7) are connected to the output terminal of the fourth operational amplifier (U6). The inverting input terminal is electrically connected. The other end of the seventh capacitor (C7), one end of the tenth resistor (R10), and one end of the eighth capacitor (C8) are connected to ground. The other end of the tenth resistor (R10), the other end of the eighth capacitor (C8), and one end of the eleventh resistor (R11) are connected to the non-inverting input terminal of the fourth operational amplifier (U6). The other end of the eleventh resistor (R11) is connected to the power supply. The output terminal of the fourth operational amplifier (U6) is electrically connected to one end of the twelfth resistor (R12).

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