Safety chain loop fault diagnosis circuit, PCB and diagnosis system

Abstract

The utility model discloses a safety chain loop fault diagnosis circuit, a PCB and a diagnosis system, the circuit comprises a safety relay MS, a trigger unit, a reset unit, a signal acquisition unit and a plurality of safety limit switches, first normally closed contact groups of the plurality of safety limit switches are connected in series with a pin S11 and a pin S12 of the safety relay MS; the normally closed end of the trigger unit is connected with a pin S12 of the safety relay MS and one end of the reset unit, and the other end of the reset unit is connected with a pin S34 of the safety relay MS; one end and the other end of a second normally closed contact group of the plurality of safety limit switches are respectively connected with a pin COM and a pin X of the signal acquisition unit; according to the circuit disclosed by the utility model, a loop formed by the safety limit switches and the safety relay can ensure that the working state of the escalator can be quickly switched when any safety limit switch acts, and the loop formed by the signal acquisition unit and the safety limit switches can realize quick positioning of a fault point.

Description

Technical Field

[0001] The utility model relates to the technical field of fault diagnosis, and in particular to a safety chain loop fault diagnosis circuit, a PCB board and a diagnosis system. Background Art

[0002] As an important supporting facility of modern rail transit stations, escalators can effectively improve the comfort of passengers riding rail transit and greatly facilitate people's travel. Now they have become an indispensable means of transportation in people's daily life.

[0003] Since there is zero-distance contact between the escalator and the passengers, the design and protection related to the personal safety of the passengers cannot be ignored; in accordance with the relevant international and domestic standards for the installation and manufacturing of escalators, many safety limit switches are installed around the escalator to detect various faults that may occur on the escalator to ensure the safe operation of the escalator. All safety switches are connected into a safety chain loop. When any safety switch is activated, the escalator will stop running or be prevented from starting. The escalator can only be restarted after pressing the reset button when the fault is eliminated.

[0004] The existing partial safety chain loop design simply connects a group of normally closed contacts of all safety limit switches installed on the escalator in series to form a safety chain loop, one end of the safety chain loop is connected to one end of a contactor coil, and the other end is connected to the control power supply of the contactor. When any safety limit switch on the safety chain is actuated, the control power supply of the contactor is cut off, and the contactor contacts then cut off the power supply of the escalator drive motor, thereby stopping the escalator. However, this design cannot determine which specific safety limit switch in the safety chain loop caused the escalator stop fault, resulting in difficulties for on-site maintenance personnel to troubleshoot the fault, reducing the efficiency of fault maintenance.

[0005] In the existing partial safety chain loop design, at each safety limit switch node in the entire safety chain loop, a separate line is led out to connect to the escalator control system to collect whether the high-level signal of this node of the safety chain is missing, so as to diagnose the action of the safety limit switch closest to the node; but when multiple safety limit switches on the safety chain are actuated at the same time, the diagnostic scheme can only diagnose the node closest to the missing high-level signal, but cannot diagnose the action status of all other actuated safety limit switches between the node and the power supply, resulting in incomplete detection and difficulty in confirming whether the fault points include multiple ones.

[0006] The existing partial safety chain loop design connects all safety limit switches in the safety chain loop back to the escalator control system. The escalator control system makes a separate signal judgment on each safety limit switch to determine the operating status of the safety limit switch. This has the problems of numerous cables and messy on-site wiring, and increases the cost of cable laying.

[0007] It can be seen that the existing technology still needs to be improved and enhanced. Utility Model Content

[0008] In view of the above-mentioned deficiencies in the prior art, the purpose of the utility model is to provide a safety chain loop fault diagnosis circuit, which can quickly switch the operating state of the escalator to a stopped state when a fault occurs, and can quickly confirm the location of the fault point, thereby improving operation and maintenance efficiency.

[0009] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0010] A safety chain loop fault diagnosis circuit comprises a safety relay MS, a trigger unit, a reset unit, a signal acquisition unit and a plurality of safety limit switches, wherein the safety limit switch comprises a first normally closed contact group and a second normally closed contact group, wherein the first normally closed contact groups of the plurality of safety limit switches, the pin S11 of the safety relay MS and the pin S12 of the safety relay MS are connected in series; the normally closed end of the trigger unit is respectively connected to the pin S12 of the safety relay MS and one end of the reset unit, the other end of the reset unit is connected to the pin S34 of the safety relay MS, the coil end of the trigger unit is respectively connected to the pin 14 and the pin 24 of the safety relay MS, and the normally open end of the trigger unit is used to connect to the driving motor of the escalator; one end of the second normally closed contact group of the plurality of safety limit switches is respectively connected to the pin COM of the signal acquisition unit, and the other end of the second normally closed contact group of the plurality of safety limit switches is respectively connected to the pin X of the signal acquisition unit.

[0011] In the safety chain loop fault diagnosis circuit, the pin S21 and the pin S22 of the safety relay MS are grounded respectively; the pin 13, the pin 23 and the pin A1 of the safety relay MS are used to connect to the power supply unit respectively.

[0012] In the safety chain loop fault diagnosis circuit, the trigger unit includes a first contactor CM1 and a second contactor CM2, the coil of the first contactor CM1 is connected to pin 14 of the safety relay MS, and the coil of the second contactor CM2 is connected to pin 24 of the safety relay MS; the pin 22 of the normally closed contact of the second contactor CM2 is connected to pin 12 of the safety relay MS, the pin 21 of the normally closed contact of the second contactor CM2 is connected to pin 21 of the normally closed contact of the first contactor CM1, and the pin 21 of the normally closed contact of the first contactor CM1 is connected to the reset unit; the normally open end of the first contactor CM1 and the normally open end of the second contactor CM2 are respectively used to connect the drive motor of the escalator.

[0013] In the safety chain loop fault diagnosis circuit, the reset unit includes a reset switch SW1, pin 2 of the reset switch SW1 is connected to pin 21 of the normally closed contact of the first contactor CM1, and pin 1 of the reset switch SW1 is connected to pin S34 of the safety relay MS.

[0014] In the safety chain loop fault diagnosis circuit, the safety limit switches include N, N is greater than or equal to 3 and is an integer, the pin X of the signal acquisition unit includes N, and the other ends of the second normally closed contact groups of the N safety limit switches are respectively connected to the N pins X of the signal acquisition unit; the 485 pin of the signal acquisition unit is used to connect the control system of the escalator.

[0015] The safety chain loop fault diagnosis circuit also includes a fuse FUO, and the first normally closed contact group of multiple safety limit switches, the pin S11 of the safety relay MS, the pin S12 of the safety relay MS and the fuse FUO are connected in series.

[0016] The present application also provides a PCB board accordingly, on which is printed any of the safety chain loop fault diagnosis circuits described above.

[0017] The present application also correspondingly provides a safety chain loop fault diagnosis system, including a fault detection device, a control system and a drive motor; the fault detection device adopts any of the above-described safety chain loop fault diagnosis circuits to achieve working control; the normally open end of the fault detection device is connected to the drive motor, and the digital signal end of the fault detection device is connected to the control system.

[0018] Beneficial effects:

[0019] The utility model provides a safety chain loop fault diagnosis circuit. The loop formed by the safety limit switch and the safety relay can ensure that when any safety limit switch is actuated, the working state of the escalator can be quickly switched to a shutdown state; the loop formed by the signal acquisition unit and the safety limit switch can realize the rapid positioning of the fault point and improve the operation and maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A first circuit structure diagram of a safety chain loop fault diagnosis circuit provided by the utility model;

[0021] Figure 2 This is a second circuit structure diagram of the safety chain loop fault diagnosis circuit provided by the utility model.

[0022] Explanation of main component symbols: 1- drive motor, 2- signal acquisition unit, 3- control system. DETAILED DESCRIPTION

[0023] The utility model provides a safety chain loop fault diagnosis circuit, a PCB board and a diagnosis system. In order to make the purpose, technical scheme and effect of the utility model clearer and more specific, the utility model is further described in detail with reference to the accompanying drawings and examples.

[0024] In the description of the present invention, it should be understood that the terms "installation", "connection" and the like should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] See also Figure 1 and Figure 2 The utility model provides a safety chain loop fault diagnosis circuit, comprising a safety relay MS, a trigger unit, a reset unit, a signal acquisition unit 2 and a plurality of safety limit switches, wherein the safety limit switch comprises a first normally closed contact group and a second normally closed contact group, wherein the first normally closed contact group of the plurality of safety limit switches, the pin S11 of the safety relay MS and the pin S12 of the safety relay MS are connected in series; the normally closed end of the trigger unit is respectively connected to the pin S12 of the safety relay MS and one end of the reset unit, the other end of the reset unit is connected to the pin S34 of the safety relay MS, the coil end of the trigger unit is respectively connected to the pin 14 and the pin 24 of the safety relay MS, and the normally open end of the trigger unit is used to connect the driving motor 1 of the escalator; one end of the second normally closed contact group of the plurality of safety limit switches is respectively connected to the pin COM of the signal acquisition unit 2, and the other end of the second normally closed contact group of the plurality of safety limit switches is respectively connected to the pin X of the signal acquisition unit 2.

[0026] The present application discloses a safety chain loop fault diagnosis circuit, in which a plurality of safety limit switches and a safety relay are connected in series. When any safety limit switch is actuated, the safety relay can control a trigger unit to stop working, so as to control a drive motor 1 of the escalator to stop working, so as to quickly switch the working state of the escalator to a shutdown state; a plurality of the safety limit switches are connected to a signal acquisition unit 2, so that it can quickly confirm which safety limit switch is actuated, thereby realizing rapid location of the fault point and improving operation and maintenance efficiency; further, the signal acquisition unit 2 is a distributed digital signal acquisition module in an escalator junction box close to the safety limit switch, which can greatly shorten the connection distance, reduce the complexity of on-site wiring, and reduce wiring costs.

[0027] In this embodiment, the first normally closed contact group 11-12 of each safety limit switch in the safety chain loop is connected in series through the nearest escalator junction box to form a safety chain loop, and is finally connected to pins S11 and S12 of the dedicated safety relay MS of the control cabinet. This safety relay MS adopts dual-channel monitoring, so that the safety level of the safety chain loop can reach EN954-1 level 4 at the highest.

[0028] For further information, see Figure 1 , pin S21 and pin S22 of the safety relay MS are grounded respectively; pin 13, pin 23 and pin A1 of the safety relay MS are used to connect to the power supply unit respectively.

[0029] In the safety chain composed of multiple safety limit switches, if any point or safety limit switch in the safety chain is connected to the ground, the safety relay will immediately disconnect all safety output circuits for self-protection to stop the operation of the escalator; in this embodiment, by grounding pins S21 and S22 of the safety relay MS, it can be prevented that two or several points in the safety chain loop are connected to the ground due to special circumstances, and the safety limit switches between these two or several points are bypassed by relying on the conductive properties of the earth, making their safety protection function invalid, that is, by grounding pins S21 and S22 of the safety relay MS, the stability and reliability of the safety link fault diagnosis circuit during operation can be greatly improved.

[0030] In this embodiment, the power supply unit may be a power supply circuit of an escalator, and the power supply unit provides a 24V DC working voltage for the safety relay.

[0031] For further information, see Figure 1The trigger unit includes a first contactor CM1 and a second contactor CM2, the coil of the first contactor CM1 is connected to the pin 14 of the safety relay MS, and the coil of the second contactor CM2 is connected to the pin 24 of the safety relay MS; the pin 22 of the normally closed contact of the second contactor CM2 is connected to the pin 12 of the safety relay MS, the pin 21 of the normally closed contact of the second contactor CM2 is connected to the pin 21 of the normally closed contact of the first contactor CM1, and the pin 21 of the normally closed contact of the first contactor CM1 is connected to the reset unit; the normally open end of the first contactor CM1 and the normally open end of the second contactor CM2 are respectively used to connect the drive motor 1 of the escalator.

[0032] For further information, see Figure 1 The reset unit includes a reset switch SW1, a pin 2 of the reset switch SW1 is connected to a pin 21 of a normally closed contact of the first contactor CM1, and a pin 1 of the reset switch SW1 is connected to a pin S34 of the safety relay MS.

[0033] In this embodiment, the pin 13 and the pin 14 of the safety relay MS are connected through a first switch, and the pin 23 and the pin 24 of the safety relay MS are connected through a second switch.

[0034] In actual operation, when all safety limit switches are not actuated, the safety chain circuit is closed. At this time, the safety relay will close the safety output circuit to energize the coils of the first contactor CM1 and the second contactor CM2 and control the operation of the drive motor 1; when any safety limit switch is actuated, the safety output circuit of the safety relay MS immediately disconnects the power supply of the coils of the first contactor CM1 and the second contactor CM2, that is, cuts off the power supply circuit of the escalator drive motor 1, and stops the escalator immediately to ensure the safety of personnel and equipment; the fault reset button SW1 of the safety relay MS is connected in series with the normally closed end of the first contactor CM1 and the normally closed end of the second contactor CM2, that is, only when the first contactor CM1 and the second contactor CM2 are both powered off, that is, when the drive motor 1 is ensured to have stopped, pressing the fault reset button SW1 can effectively reset the safety relay MS to restore the drive motor 1 to the operating state.

[0035] For further information, see Figure 2, the second normally closed contact group 21-22 of the safety limit switch is connected to the signal acquisition unit 2; the safety limit switch includes N, N is greater than or equal to 3 and is an integer, the pin X of the signal acquisition unit 2 includes N, and the other ends of the second normally closed contact groups of the N safety limit switches are respectively connected to the N pins X of the signal acquisition unit 2; the 485 pin of the signal acquisition unit 2 is used to connect the control system 3 of the escalator.

[0036] In this embodiment, the safety limit switch includes S1, S2...Sn, the signal acquisition unit 2 includes pin X1, pin X2...pin Xn, the other end of the second normally closed contact group of the safety limit switch S1 is connected to the pin X1 of the signal acquisition unit 2, the other end of the second normally closed contact group of the safety limit switch S2 is connected to the pin X2 of the signal acquisition unit 2, and the other end of the second normally closed contact group of the safety limit switch Sn is connected to the pin Xn of the signal acquisition unit 2.

[0037] In this embodiment, the 485 pin of the signal acquisition unit 2 is used to connect to the control system 3 of the escalator, and the state of each safety limit switch in the safety chain loop is transmitted to the control system 3 of the escalator through the 485 communication method; the control system 3 controls the escalator in a software manner to cut off the control power supply of the power supply circuit of the drive motor 1 in a fault state, so that the escalator stops running immediately, and outputs fault information to the fault display screen to facilitate the diagnosis of the specific fault point in the safety chain loop; further, a heartbeat detection diagnosis with a period of 1 second is adopted between the control system 3 of the escalator and the signal acquisition unit 2, that is, the control system 3 of the escalator sends a pulse signal to the signal acquisition unit 2 every second. If the control system 3 does not receive a response signal from the signal acquisition unit 2 within the set 1 second, it is determined that the signal acquisition unit 2 and the control system 3 of the escalator have interrupted communication, and the escalator will stop and display a communication interruption fault code to inform the maintenance personnel to handle and solve it, so as to prevent the specific fault point diagnosis function of the safety chain from failing.

[0038] For further information, see Figure 1 The safety chain loop fault diagnosis circuit also includes a fuse FUO, and the first normally closed contact group of multiple safety limit switches, the pin S11 of the safety relay MS, the pin S12 of the safety relay MS and the fuse FUO are connected in series.

[0039] In this embodiment, a fuse FUO is added to the safety chain loop to protect the circuit. When the current exceeds its preset rated value, the fuse will generate heat to melt the fuse, thereby disconnecting the circuit to prevent circuit overload or short circuit, thereby avoiding equipment damage or fire.

[0040] The present application also provides a PCB board accordingly, on which is printed any of the safety chain loop fault diagnosis circuits described above.

[0041] The present application also correspondingly provides a safety chain loop fault diagnosis system, including a fault detection device, a control system 3 and a drive motor 1; the fault detection device adopts any of the above-described safety chain loop fault diagnosis circuits to achieve working control; the normally open end of the fault detection device is connected to the drive motor 1, and the digital signal end of the fault detection device is connected to the control system 3.

[0042] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and the utility model concept of the utility model, and all these changes or substitutions should fall within the protection scope of the utility model.

Claims

1. A safety chain loop fault diagnosis circuit, characterized in that: It includes a safety relay MS, a trigger unit, a reset unit, a signal acquisition unit and multiple safety limit switches, the safety limit switches include a first normally closed contact group and a second normally closed contact group, the first normally closed contact groups of multiple safety limit switches, the pin S11 of the safety relay MS and the pin S12 of the safety relay MS are connected in series; the normally closed end of the trigger unit is respectively connected to the pin S12 of the safety relay MS and one end of the reset unit, the other end of the reset unit is connected to the pin S34 of the safety relay MS, the coil end of the trigger unit is respectively connected to the pin 14 and pin 24 of the safety relay MS, and the normally open end of the trigger unit is used to connect the drive motor of the escalator; one end of the second normally closed contact group of multiple safety limit switches is respectively connected to the pin COM of the signal acquisition unit, and the other end of the second normally closed contact group of multiple safety limit switches is respectively connected to the pin X of the signal acquisition unit.

2. A safety chain loop fault diagnosis circuit according to claim 1, characterized in that: Pin S21 and pin S22 of the safety relay MS are grounded respectively; pin 13, pin 23 and pin A1 of the safety relay MS are used to connect to a power supply unit respectively.

3. A safety chain loop fault diagnosis circuit according to claim 2, characterized in that: The trigger unit includes a first contactor CM1 and a second contactor CM2, the coil of the first contactor CM1 is connected to the pin 14 of the safety relay MS, and the coil of the second contactor CM2 is connected to the pin 24 of the safety relay MS; the pin 22 of the normally closed contact of the second contactor CM2 is connected to the pin 12 of the safety relay MS, the pin 21 of the normally closed contact of the second contactor CM2 is connected to the pin 21 of the normally closed contact of the first contactor CM1, and the pin 21 of the normally closed contact of the first contactor CM1 is connected to the reset unit; the normally open end of the first contactor CM1 and the normally open end of the second contactor CM2 are respectively used to connect the drive motor of the escalator.

4. A safety chain loop fault diagnosis circuit according to claim 3, characterized in that: The reset unit comprises a reset switch SW1 , a pin 2 of the reset switch SW1 is connected to a pin 21 of a normally closed contact of the first contactor CM1 , and a pin 1 of the reset switch SW1 is connected to a pin S34 of the safety relay MS.

5. A safety chain loop fault diagnosis circuit according to claim 1, characterized in that: The safety limit switches include N, N is greater than or equal to 3 and is an integer, the pin X of the signal acquisition unit includes N, and the other ends of the second normally closed contact groups of the N safety limit switches are respectively connected to the N pins X of the signal acquisition unit; the 485 pin of the signal acquisition unit is used to connect the control system of the escalator.

6. A safety chain loop fault diagnosis circuit according to claim 1, characterized in that: It also includes a fuse FUO, and the first normally closed contact group of the plurality of safety limit switches, the pin S11 of the safety relay MS, the pin S12 of the safety relay MS and the fuse FUO are connected in series.

7. A PCB board, characterized in that: The PCB board is printed with the safety chain loop fault diagnosis circuit as described in any one of claims 1-6.

8. A safety chain loop fault diagnosis system, characterized in that: It includes a fault detection device, a control system and a drive motor; the fault detection device adopts the safety chain loop fault diagnosis circuit as described in any one of claims 1 to 6 to realize working control; the normally open end of the fault detection device is connected to the drive motor, and the digital signal end of the fault detection device is connected to the control system.

Images