Contact resistance testing device for relay / contactor of motor train unit

Abstract

A contact resistance value testing device for a relay / contactor of a motor train unit comprises a digital display resistance meter power supply circuit and a relay / contactor contact resistance value measuring circuit, and the digital display resistance meter power supply circuit is used for providing a working power supply for a digital display resistance meter and providing a measuring power supply for the relay / contactor contact resistance value measuring circuit; the relay / contactor contact resistance value measuring circuit is characterized in that resistance values of different contacts can be measured in a switching manner by operating a measuring selection switch through contact wiring connected to a relay / contactor. According to the utility model, the relay / contactor contact feedback wiring harness is connected for measurement, errors caused by contact measurement by using a universal meter are avoided, and meanwhile, different contact resistance values are respectively switched and measured through the measurement change-over switch for comparison and verification, so that the accuracy of fault judgment is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of rail vehicle control circuits, and in particular relates to a device for measuring the resistance of a contact line of a relay / contactor of a motor vehicle unit. Background Art

[0002] The relays and contactors of EMUs are the most commonly used electronic components on the vehicle. Each relay and contactor has 3 or 4 control contacts for the EMU loop control and feedback monitoring circuit. In recent years, the resistance of the control contacts of relays and contactors has often been abnormal during the operation of EMUs, resulting in vehicle driving failures. The reasons are mostly due to the oxidation of the relay and contactor contacts, which leads to increased impedance of the conduction contacts or the thermal expansion and burning of the coils themselves. Due to occasional failures of relays and contactors, there is an error of poor contact surface when using a multimeter to measure the contact surface during the current vehicle fault judgment process, resulting in inaccurate measurement. Therefore, a relay and contactor contact resistance measuring device is manufactured. The external wiring harness can be connected to the relay and contactor contacts and then to the relay / contactor contact resistance testing device. The resistance of all relevant contacts can be measured by operating the three-position selection switch, which improves the efficiency and accuracy of relay and contactor contact fault troubleshooting. Utility Model Content

[0003] The utility model aims to provide a contact resistance test device for a relay / contactor of a multiple unit train. When handling a contact fault of a relay or contactor control loop, the device can measure the resistance of different contacts of the relay / contactor and compare the resistance of different contacts, thereby improving the efficiency and accuracy of fault handling.

[0004] In order to achieve the above-mentioned utility model object, the utility model provides a device for testing the contact resistance of a relay / contactor of a train, comprising a digital resistance meter power supply circuit, a relay / contactor contact resistance measurement circuit, and a digital resistance meter, wherein:

[0005] The power supply circuit of the digital display resistance meter includes a rechargeable battery, a start switch, and an LED digital display resistance meter. The positive electrode of the rechargeable battery is connected to the input point contact of the start switch, and then connected to the positive power electrode of the LED digital display resistance meter from the output point of the start switch; the negative electrode of the rechargeable battery is directly connected to the negative power electrode of the LED digital display resistance meter.

[0006] The relay / contactor contact resistance measurement circuit comprises a first three-gear selection switch, a second three-gear selection switch, a third three-gear selection switch and a terminal strip; the signal detection positive pole of the LED digital display resistance meter is connected to the a contact of the first three-gear selection switch, the b contact and the c contact of the first three-gear selection switch are respectively connected to the a contact of the second three-gear selection switch and the third three-gear selection switch, and then the b contact and the c contact of the second three-gear selection switch and the third three-gear selection switch are respectively connected to the positive contact holes 1, 2, 3 and 4 of the terminal strip, and the signal detection negative pole of the LED digital display resistance meter is directly connected to the negative contact hole 5 of the terminal strip. By operating the first three-gear selection switch, the second three-gear selection switch and the third three-gear selection switch, four groups of different contact conduction performance states of the measuring relay / contactor can be controlled and switched.

[0007] Furthermore, the a contact of the first three-gear selection switch is connected to the signal detection positive pole of the LED digital display resistance meter, the b contact is connected to the a contact of the second three-gear selection switch, the b contact of the second three-gear selection switch is connected to hole 1 of the terminal strip, and the c contact of the second three-gear selection switch is connected to hole 2 of the terminal strip; the c contact of the first three-gear selection switch is connected to the a contact of the third three-gear selection switch, the b contact of the third three-gear selection switch is connected to hole 3 of the terminal strip, and the c contact of the third three-gear selection switch is connected to hole 4 of the terminal strip.

[0008] Furthermore, the rechargeable battery is a constant voltage lithium battery, and the interface voltage is DC5V.

[0009] Furthermore, the starting switch model is a boat-type switch KCD1.

[0010] Furthermore, the LED digital display resistance meter is a YB5135R three-and-a-half-digit LED digital ohmmeter.

[0011] The advantages and progress of the utility model over the background technology are as follows:

[0012] When the control loop fails due to abnormal contacts of relays and contactors in existing EMUs, the original inspection method can only measure the contact resistance of the relevant contacts through a multimeter. Since the multimeter probe cannot fully contact the contact surface of the relay and contactor contacts, there is a certain error in the measured resistance value. Therefore, a EMU relay / contactor contact resistance test device is designed and manufactured, which can realize the measurement function of different contact resistance values ​​of relays and contactors. The advantages are as follows:

[0013] The contact measurement is reliable, simulating the working environment of the existing vehicle relays and contactors. The external wiring harness is connected to the relevant contacts of the relay / contactor under test and then connected to the relay / contactor contact resistance test device, which can ensure that the contact measurement conditions of the relay / contactor under test are consistent with those of the existing vehicle, and ensure the accuracy of the measured contact resistance.

[0014] (2) Different contact measurements can be switched. The three-position selection switch installed on the EMU relay / contactor contact resistance test device can switch to four different contact resistances of the relay and contactor. This is used to measure and compare the resistance of different contacts, which is convenient for fault diagnosis.

[0015] (3) The measuring device has a built-in rechargeable battery, which can be used to charge the EMU relay / contactor contact resistance test device through a data cable, thereby reducing energy consumption and achieving recycling function. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the internal schematic diagram of the EMU relay / contactor contact resistance test device;

[0017] Among them: 1-first three gear selection switch, 2-second three gear selection switch, 3-third three gear selection switch, 4-rechargeable battery, 5-start switch, 6-LED digital resistance meter, 7-terminal block; among them, 1-first three gear selection switch, 2-second three gear selection switch and 3-third three gear selection switch are three gear contacts respectively, the middle gear contact is a, and the other two gear contacts are b and c. DETAILED DESCRIPTION

[0018] In order to better understand the purpose, structure and function of the utility model, the following is a further detailed description of the EMU line alignment measurement device of the utility model in conjunction with the accompanying drawings.

[0019] Reference Figure 1 The EMU relay / contactor contact resistance test device includes a digital display resistance meter power supply circuit and a relay / contactor contact resistance measurement circuit. The digital display resistance meter power supply circuit includes a DC5V rechargeable battery 4 and a start switch 5. After the positive electrode of the DC5V rechargeable battery 4 enters the input contact of the start switch 5, it is connected to the positive electrode of the power supply of the LED digital display resistance meter 6 from the output contact of the start switch 5; the negative electrode of the rechargeable battery 4 is directly connected to the negative electrode of the power supply of the LED digital display resistance meter 6. The specific wiring assembly process is as follows:

[0020] 1. Positive pole of power supply: positive pole of DC5V rechargeable battery 4 (constant voltage lithium battery) → input contact of start switch 5 (boat switch KCD1) → output contact of start switch 5 → positive pole of power supply of LED digital display resistance meter 6;

[0021] 2. Negative pole of power supply: negative pole of DC5V rechargeable battery 4 (constant voltage lithium battery) → negative pole of power supply of LED digital display resistance meter 6.

[0022] The relay / contactor contact resistance measurement circuit includes three three-position selection switches (rocker toggle switch three-position triangle) and a terminal strip 7 (wall panel fixed terminal 5P); the three three-position selection switches are the first three-position selection switch 1, the second three-position selection switch 2, and the third three-position selection switch 3, and the positive pole of the signal detection of the LED digital resistance meter 6 is connected to the a contact of the first three-position selection switch 1, and then the b contact and c contact of the second three-position selection switch 2 and the third three-position selection switch 3 are respectively connected to the positive contact holes 1, 2, 3, and 4 of the terminal strip 7 (a total of four wires), and the negative pole of the signal detection of the LED digital resistance meter 6 is directly connected to the negative contact hole 5 of the terminal strip 7. By operating the three three-position selection switches, the four groups of different contact conduction performance states of the relay / contactor can be controlled and switched to be measured. The specific wiring method is:

[0023] 1. The positive pole of the test line of LED digital resistance meter 6 (YB5135R three-and-a-half-digit LED digital ohmmeter) → the a contact of the first three-position selection switch 1, the b contact is connected to the a contact of the second three-position selection switch 2, and then the b contact and c contact of the second three-position selection switch 2 are respectively connected to the 1st and 2nd holes of the terminal strip 7;

[0024] The c contact of the first three-gear selection switch 1 is connected to the a contact of the third three-gear selection switch 3, and the b contact and c contact of the third three-gear selection switch 3 are connected to the 3rd hole and the 4th hole of the terminal block 7 respectively.

[0025] 2. LED digital display resistance meter 6 (YB5135R three-and-a-half-digit LED digital ohmmeter) detects the negative pole of the wire → the negative contact 5 hole of the terminal strip 7.

[0026] The control contacts of EMU relays and contactors are divided into 3 or 4 groups for EMU loop control and feedback monitoring circuits. Based on this, an EMU relay / contactor contact resistance test device is made to ensure that the measured resistance of the relay / contactor contacts is consistent with the wiring conditions of the actual vehicle, and to ensure effective contact of the contact surfaces of the contacts under test. At the same time, by operating the three-position selection switch for contact measurement, four groups of different contact resistances of the relay / contactor can be switched to compare the resistances, ensuring measurement reliability and practicality.

Claims

1. A contact resistance test device for a train relay / contactor, characterized in that: The digital resistance meter power supply circuit is composed of a digital resistance meter power supply circuit and a relay / contactor contact resistance measurement circuit, wherein: the digital resistance meter power supply circuit includes a rechargeable battery, a start switch, and an LED digital resistance meter. After the positive electrode of the rechargeable battery is connected to the input point of the start switch, the positive electrode of the power supply of the LED digital resistance meter is connected from the output point of the start switch; the negative electrode of the rechargeable battery is directly connected to the negative electrode of the power supply of the LED digital resistance meter; The relay / contactor contact resistance measurement circuit comprises a first three-gear selection switch, a second three-gear selection switch, a third three-gear selection switch and a terminal strip; the signal detection positive pole of the LED digital display resistance meter is connected to the a contact of the first three-gear selection switch, the b contact and the c contact of the first three-gear selection switch are respectively connected to the a contact of the second three-gear selection switch and the third three-gear selection switch, and then the b contact and the c contact of the second three-gear selection switch and the third three-gear selection switch are respectively connected to the positive contact holes 1, 2, 3 and 4 of the terminal strip, and the signal detection negative pole of the LED digital display resistance meter is directly connected to the negative contact hole 5 of the terminal strip. By operating the first three-gear selection switch, the second three-gear selection switch and the third three-gear selection switch, four groups of different contact conduction performance states of the measuring relay / contactor can be controlled and switched.

2. A contact resistance test device for a relay / contactor of a train set according to claim 1, characterized in that: The a contact of the first three-gear selection switch is connected to the signal detection positive pole of the LED digital display resistance meter, the b contact is connected to the a contact of the second three-gear selection switch, the b contact of the second three-gear selection switch is connected to the 1 hole of the wiring terminal plug row, and the c contact of the second three-gear selection switch is connected to the 2 hole of the wiring terminal plug row; the c contact of the first three-gear selection switch is connected to the a contact of the third three-gear selection switch, the b contact of the third three-gear selection switch is connected to the 3 hole of the wiring terminal plug row, and the c contact of the third three-gear selection switch is connected to the 4 hole of the wiring terminal plug row.

3. The device for testing the contact resistance of a relay / contactor for a train set according to claim 1, characterized in that: The rechargeable battery is a constant voltage lithium battery, and the interface voltage is DC5V.

4. The device for testing the contact resistance of a relay / contactor for a train set according to claim 1, characterized in that: The starting switch model is a rocker switch KCD1.

5. The device for testing the contact resistance of a relay / contactor for a train set according to claim 1, characterized in that: The LED digital display resistance meter is a YB5135R three and a half digit LED digital ohmmeter.

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