Measurement equipment for drift value of pressure switch of metro vehicle

Abstract

The specification provides a device for measuring the drift value of a pressure switch of a metro vehicle, and the device comprises a pressure gauge which displays the air pressure value of a detection air flow inputted from an air inlet and outputted from an air outlet; one end of the wiring port is connected with a tested pressure switch, and the other end of the wiring port is connected with one ends of second, third, fifth and sixth female holes of the seven-hole plug; the first indicating lamp, the second indicating lamp, the third indicating lamp and the fourth indicating lamp are connected in parallel, the first indicating lamp is connected with the other end of the second female hole of the seven-hole plug, the second indicating lamp is connected with the other end of the third female hole of the seven-hole plug, the third indicating lamp is connected with the other end of the fifth female hole of the seven-hole plug, and the fourth indicating lamp is connected with the fifth female hole of the seven-hole plug. The fourth indicating lamp is connected with the other end of the sixth female hole of the seven-hole plug. And the pressure regulating valve is used for regulating the air pressure value of the detection airflow. Pressure switch drift value detection which can be operated by a single person is realized, and temporary assembly of related detection instruments is not needed, so that the problem of low measurement precision caused by manual assembly is avoided.

Description

Technical Field

[0001] The present specification relates to the field of air pressure detection technology, and in particular to a device for measuring drift values ​​of pressure switches in subway vehicles. Background Art

[0002] The drift value detection of subway vehicle pressure switches is an important project in subway vehicle maintenance. The "pressure switch" is a device that controls the circuit through pressure. The start and stop control of the train air compressor and the feedback of the control signal are closely related to the "air pressure value" of this pressure switch. The traditional method of testing the drift value of the pressure switch is to use a pressure regulating valve and a multimeter to measure, adjust the test air pressure through the pressure regulating valve, and measure the conduction of the corresponding contacts through the multimeter. This method has the disadvantages of requiring two operators to cooperate with each other, requiring temporary assembly, and low measurement accuracy. Utility Model Content

[0003] In view of this, the embodiments of this specification provide a device for measuring the drift value of a pressure switch in a subway vehicle to solve the technical defects existing in the prior art.

[0004] According to a first aspect of an embodiment of this specification, a device for measuring drift value of a pressure switch of a subway vehicle is provided, comprising:

[0005] A pressure gauge 1 displays the pressure value of the detected air flow input from the air inlet 2 and output from the air outlet 3;

[0006] Wiring port 4, one end of which is connected to the pressure switch to be measured, and the other end is connected to one end of the 2nd, 3rd, 5th, and 6th female holes of the seven-hole plug;

[0007] The first indicator light 5, the second indicator light 6, the third indicator light 7 and the fourth indicator light 8 are connected in parallel, and the first indicator light 5 is connected to the other end of the second female hole of the seven-hole plug, the second indicator light 6 is connected to the other end of the third female hole of the seven-hole plug, the third indicator light 7 is connected to the other end of the fifth female hole of the seven-hole plug, and the fourth indicator light 8 is connected to the other end of the sixth female hole of the seven-hole plug;

[0008] The pressure regulating valve 9 is used to adjust the pressure value of the detected airflow.

[0009] Optionally, the device for measuring drift value of subway vehicle pressure switch further comprises a detection interface 10, wherein the detection interface 10 receives a corrected airflow of a preset air pressure value and corrects the pressure gauge 1 according to the preset air pressure value.

[0010] Optionally, the drift value measuring device for the subway vehicle pressure switch further comprises a power switch 11, one end of the power switch 11 is connected to the power module, and the other end is connected to one end of the 1st and 4th female holes of the seven-hole plug.

[0011] Optionally, the device for measuring the drift value of a subway vehicle pressure switch further includes a charging port 12, and the charging port 12 is connected to the power module to charge the power module.

[0012] Optionally, the power supply module is a direct current power supply with constant voltage and constant current output.

[0013] Optionally, the device for measuring drift value of a subway vehicle pressure switch comprises:

[0014] The other end of the first female hole of the seven-hole plug is connected to the pressure switch to be measured, and forms a first circuit with the first indicator light 5, and forms a second circuit with the second indicator light 6;

[0015] The other end of the fourth female hole of the seven-hole plug is connected to the pressure switch to be measured, and forms a third circuit with the third indicator light 7, and forms a fourth circuit with the fourth indicator light 8.

[0016] Optionally, the drift value measuring device for the subway vehicle pressure switch also includes a test light button 13, one end of the test light button 13 is connected to the connection point between the power switch 11 and the 1st and 4th female holes of the seven-hole plug, and the other end is connected to the first indicator light 5 and the 2nd female hole of the seven-hole plug, the second indicator light 6 and the 3rd female hole of the seven-hole plug, the third indicator light 7 and the 5th female hole of the seven-hole plug, and the fourth indicator light 8 and the 6th female hole of the seven-hole plug.

[0017] Optionally, the device for measuring drift value of a subway vehicle pressure switch further comprises:

[0018] In the parallel circuit formed by the first indicator light 5 , the second indicator light 6 , the third indicator light 7 and the fourth indicator light 8 , a unidirectional conducting diode is arranged on each branch.

[0019] The drift value measuring device for the pressure switch of a subway vehicle provided in the embodiment of this specification includes: a pressure gauge 1, which displays the air pressure value of the detected airflow input from the air inlet 2 and output from the air outlet 3; a wiring port 4, one end of which is connected to the pressure switch to be measured, and the other end is connected to one end of the second, third, fifth, and sixth female holes of the seven-hole plug; a first indicator light 5, a second indicator light 6, a third indicator light 7, and a fourth indicator light 8 are connected in parallel, and the first indicator light 5 is connected to the other end of the second female hole of the seven-hole plug, the second indicator light 6 is connected to the other end of the third female hole of the seven-hole plug, the third indicator light 7 is connected to the other end of the fifth female hole of the seven-hole plug, and the fourth indicator light 8 is connected to the other end of the sixth female hole of the seven-hole plug; a pressure regulating valve 9 is used to adjust the air pressure value of the detected airflow. The relevant equipment for detecting the drift value of the pressure switch is integrated. A single-person-operable pressure switch drift value detection is realized. Compared with the traditional pressure switch detection method in which a multimeter is used to measure the conduction status of corresponding contacts, the subway vehicle pressure switch drift value measurement device does not require temporary assembly of related detection instruments, is easy to use, has improved dust and drop resistance, and avoids the problem of low measurement accuracy caused by manual assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of this specification, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of a device for measuring drift value of a pressure switch of a subway vehicle provided in an embodiment of this specification;

[0022] Figure 2 This is a circuit diagram of a device for measuring drift value of a pressure switch in a subway vehicle provided in an embodiment of this specification. DETAILED DESCRIPTION

[0023] Many specific details are described in the following description to facilitate a full understanding of this specification. However, this specification can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of this specification, so this specification is not limited to the specific implementation disclosed below.

[0024] The terms used in one or more embodiments of this specification are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of this specification. The singular forms of "a", "said" and "the" used in one or more embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0025] It should be understood that although the terms first, second, etc. may be used to describe various information in one or more embodiments of this specification, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of this specification, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0026] First, the terms involved in one or more embodiments of this specification are explained.

[0027] Pressure switch: It uses high-precision and high-stability pressure sensors and transmission circuits, and then uses dedicated CPU modular signal processing technology to achieve detection, display, alarm and control signal output of medium pressure signals.

[0028] Drift value: The phenomenon that the output value of the instrument deviates from the fixed standard when there is no gas input. This may be due to factors such as temperature changes and unstable power supply voltage. The drift value of the gas detector can be divided into zero drift and range drift. Zero drift refers to the drift of the output value of the instrument when no gas is detected, while range drift refers to the drift of the output value of the instrument when gas is detected.

[0029] In this specification, a device for measuring drift value of a pressure switch for a subway vehicle is provided, which is described in detail one by one in the following embodiments.

[0030] See also Figure 1 , Figure 1 A schematic diagram of a device for measuring drift value of a pressure switch of a subway vehicle according to an embodiment of the present specification is shown. Figure 1 As shown, the device for measuring drift value of pressure switch for subway vehicles comprises:

[0031] A pressure gauge 1 displays the pressure value of the detected air flow input from the air inlet 2 and output from the air outlet 3;

[0032] Wiring port 4, one end of which is connected to the pressure switch to be measured, and the other end is connected to one end of the 2nd, 3rd, 5th, and 6th female holes of the seven-hole plug;

[0033] The first indicator light 5, the second indicator light 6, the third indicator light 7 and the fourth indicator light 8 are connected in parallel, and the first indicator light 5 is connected to the other end of the second female hole of the seven-hole plug, the second indicator light 6 is connected to the other end of the third female hole of the seven-hole plug, the third indicator light 7 is connected to the other end of the fifth female hole of the seven-hole plug, and the fourth indicator light 8 is connected to the other end of the sixth female hole of the seven-hole plug;

[0034] The pressure regulating valve 9 is used to adjust the pressure value of the detected airflow.

[0035] Among them, the gas source of the device under test is connected to the air inlet 2 to provide a test airflow. It should be noted that the device under test can be an air compressor or other device that can compress or expand the gas to achieve a change in the air pressure value. The specific type of the device under test is determined by the actual usage scenario and is not limited in this embodiment.

[0036] In addition, there is a passage between the air inlet 2 and the air outlet 3, through which the detection air flow flows from the air inlet 2 to the air outlet 3, and is discharged through the air outlet 3. The device for measuring the drift value of the pressure switch of a subway vehicle in this embodiment can adjust the air pressure value of the detection air flow in the passage, such as by controlling the cross-sectional area of ​​the passage, or by driving a compressor through a preset motor, etc. The specific adjustment method is determined by the actual usage scenario and is not limited in this embodiment.

[0037] In addition, the pressure gauge 1 detects the air pressure value of the airflow in the passage between the air inlet 2 and the air outlet 3 in real time, and displays the detection result. The wiring port 4 is responsible for connecting the pressure switch to be tested, and forms a circuit with the first indicator light 5, the second indicator light 6, the third indicator light 7 and the fourth indicator light 8 through a seven-hole plug.

[0038] Based on this, during the pressure switch drift value detection process, the tester connects the contacts of the pressure switch under test to the wiring port 4, wherein the wiring port 4 has multiple different wiring points, each wiring point is respectively connected to one end of the 2nd, 3rd, 5th, and 6th female holes of the seven-hole plug. If the pressure switch under test is connected to a wiring point of the wiring port 4, the wiring point is connected to one end of the 2nd female hole of the seven-hole plug, and the other end of the 2nd female hole of the seven-hole plug is connected to the first indicator light 5.

[0039] In this case, the air pressure value of the detected airflow is adjusted by the pressure regulating valve 9 so that the air pressure value of the detected airflow changes from small to large. When the air pressure value of the detected airflow meets the trigger threshold of the pressure switch under test, the pressure switch is turned on. At this time, the first indicator light 5 connected to the pressure switch under test changes from an original non-conducting circuit to a conducting circuit. At this time, the first indicator light 5 that was originally off will light up. The tester knows that the pressure switch under test is turned on at this time based on the on and off status of the first indicator light 5. The air pressure value of the detected airflow at this time is further known through the pressure gauge 1. The actual working parameters of the pressure switch under test are known through the pressure value, and the drift value detection of the pressure switch is completed.

[0040] The above-tested pressure switch is a normally closed pressure switch, that is, it is turned on when the air pressure rises to the set value. In addition, there is also a normally open pressure switch, that is, it is turned on when the air pressure drops to the set value. In this case, it is similar to the above-mentioned pressure switch drift value detection method, except that the first indicator light 5 will remain on at the beginning of the test until the air pressure value of the detected airflow reaches the set value of the pressure switch under test. The pressure switch under test changes from on to off, and the first indicator light 5 will go out at this time. The tester determines the actual working parameters of the pressure switch under test based on the data displayed on the barometer 2 of the on and off change time of the first indicator light 5, and completes the pressure switch drift value detection.

[0041] It should be noted that Figure 1 It is only a schematic diagram of the drift value measuring device for the pressure switch of a subway vehicle, wherein the position of each component is not limited, and the user can adjust the position of each component based on his own needs. In addition, the shape of each component is not limited, and the user can set the shape of each component based on his own needs. In addition, by setting four groups of indicator lights, the drift value of multiple pressure switches under test can be detected at the same time, or the drift value of the same pressure switch under test with multiple contacts can be detected.

[0042] In a specific implementation, the device for measuring the drift value of the subway vehicle pressure switch further comprises a detection interface 10, wherein the detection interface 10 receives a corrected air flow of a preset air pressure value and corrects the pressure gauge 1 according to the preset air pressure value.

[0043] In an actual usage scenario, the detection interface 10 is connected to an air source, and the air source inputs a corrective airflow into the detection interface 10 , and the air pressure value of the corrective airflow is known.

[0044] Based on this, there may be a passage between the detection interface 10 and the air outlet 3, or there may be a passage between the detection interface 10 and a separately arranged air outlet, and the passage is for the corrected airflow to pass through. The specific form of the passage is determined by the actual usage scenario and is not limited in this embodiment. The barometer 2 can detect the air pressure value of the corrected airflow in the passage and display the detection result. By comparing the air pressure value displayed by the barometer 2 with the actual known air pressure value of the corrected airflow, the barometer is calibrated through a pre-set adjustment component to ensure the detection accuracy of the barometer 2. It should be noted that the adjustment component may be a button, a knob, a dial, an adjustment screw, etc. The specific type of adjustment component is determined by the actual usage scenario and is not limited in this embodiment.

[0045] In a specific implementation, the drift value measuring device for the subway vehicle pressure switch also includes a power switch 11, one end of which is connected to the power module, and the other end is connected to one end of the 1st and 4th female holes of the seven-hole plug.

[0046] Among them, Figure 2 As shown in the circuit diagram of a subway vehicle pressure switch drift value measuring device, KEY1 power switch, i.e., power switch 11, has one end connected to the power module, i.e., B1 in the figure, and the other end connected to one end of the 1st and 4th female holes of the seven-hole plug, wherein X1-1 represents the 1st female hole of the seven-hole plug, and X1-4 represents the 4th female hole of the seven-hole plug.

[0047] In a specific implementation, the device for measuring the drift value of the subway vehicle pressure switch further includes a charging port 12, and the charging port 12 is connected to the power module to charge the power module.

[0048] Among them, the charging port 12 can be connected to a voltage stabilizing module, an AC / DC conversion module, and a transformer module. The voltage stabilizing module stabilizes the voltage of the external power input; the AC / DC conversion module converts the voltage of the external power input from AC to DC, or converts DC to AC, to meet the charging requirements of the power module; the transformer module adjusts the voltage of the external power input to meet the rated voltage conditions of the power module. It should be noted that the module selection connected to the charging port 12 is determined by the actual usage scenario and the actual usage requirements of the user, and this embodiment does not limit it.

[0049] During specific implementation, the power supply module is a DC power supply with constant voltage and constant current output.

[0050] Among them, Figure 2As shown in the circuit diagram of a subway vehicle pressure switch drift value measuring device, the power supply module can be selected as B1, a power supply of two 18650s connected in series, or other DC power supplies can be selected. The specific power supply type is selected based on the requirements for the output power, volume, weight and other factors of the DC power supply in the actual use scenario, and this embodiment does not limit it.

[0051] During specific implementation, the other end of the first female hole of the seven-hole plug is connected to the pressure switch under test, and forms a first circuit with the first indicator light 5, and a second circuit with the second indicator light 6; the other end of the fourth female hole of the seven-hole plug is connected to the pressure switch under test, and forms a third circuit with the third indicator light 7, and a fourth circuit with the fourth indicator light 8.

[0052] Among them, one end of the first indicator light 5 is connected to the second female hole of the seven-hole plug, the second female hole is connected to the pressure switch to be measured through the wiring port 4, and the pressure switch to be measured is connected to the first female hole of the seven-hole plug to form a first circuit; similarly, one end of the second indicator light 6 is connected to the third female hole of the seven-hole plug, the third female hole is connected to the pressure switch to be measured through the wiring port 4, and the pressure switch to be measured is connected to the first female hole of the seven-hole plug to form a second circuit; similarly, one end of the third indicator light 7 is connected to the fifth female hole of the seven-hole plug, the fifth female hole is connected to the pressure switch to be measured through the wiring port 4, and the pressure switch to be measured is connected to the fourth female hole of the seven-hole plug to form a third circuit; similarly, one end of the fourth indicator light 8 is connected to the sixth female hole of the seven-hole plug, the sixth female hole is connected to the pressure switch to be measured through the wiring port 4, and the pressure switch to be measured is connected to the fourth female hole of the seven-hole plug to form a fourth circuit.

[0053] Specifically, Figure 2 A circuit diagram of a subway vehicle pressure switch drift value measuring device is provided, wherein bulb L2 is the first indicator light 5, bulb L3 is the second indicator light 6, bulb L5 is the third indicator light 7, and bulb L6 is the fourth indicator light 8; X1-2 represents the second female hole of the seven-hole plug, X1-3 represents the third female hole of the seven-hole plug, X1-5 represents the fifth female hole of the seven-hole plug, and X1-6 represents the sixth female hole of the seven-hole plug; in addition, (1 / 2) represents the first circuit including the first and second female holes of the seven-hole plug, (1 / 3) represents the second circuit including the first and third female holes of the seven-hole plug, (4 / 5) represents the third circuit including the fourth and fifth female holes of the seven-hole plug, and (4 / 6) represents the fourth circuit including the fourth and sixth female holes of the seven-hole plug.

[0054] It should be noted that the first indicator light 5, the second indicator light 6, the third indicator light 7 and the fourth indicator light 8 can be conventional incandescent bulbs, light-emitting diodes, or LED lamps. The specific type selection is not unique and is determined by the actual usage scenario, and this embodiment does not limit it.

[0055] In a specific implementation, the drift value measuring device for the subway vehicle pressure switch also includes a test light button 13, one end of which is connected to the connection point between the power switch 11 and the 1st and 4th female holes of the seven-hole plug, and the other end is connected to the first indicator light 5 and the 2nd female hole of the seven-hole plug, the second indicator light 6 and the 3rd female hole of the seven-hole plug, the third indicator light 7 and the 5th female hole of the seven-hole plug, and the fourth indicator light 8 and the 6th female hole of the seven-hole plug.

[0056] Among them, Figure 2 As shown in the circuit diagram of a subway vehicle pressure switch drift value measuring device provided, the KEY2 test light button is the test light button 13. Before the tester performs the pressure switch drift value detection, after closing the power switch 11, the test light button 13 is closed. At this time, the first indicator light 5, the second indicator light 6, the third indicator light 7 and the fourth indicator light 8 all form a passage, and the four indicator lights will be lit from the off state. The tester determines whether the indicator light or the circuit branch where the indicator light is located has a fault based on the actual changes in the indicator light. If the first indicator light 5 changes from off to on, it proves that the first indicator light 5 and the circuit branch where it is located have no fault. If the first indicator light 5 remains off, it proves that the first indicator light 5 or the circuit branch where it is located is open circuited. If the first indicator light 5 remains on, it proves that the first indicator light 5 or the circuit branch where it is located is short circuited.

[0057] Based on this, the tester judges the conditions of each indicator light and the circuit branch to which it belongs according to the on and off conditions of each indicator light. If some of the indicator lights and the circuit branches to which they belong are faulty, other indicator lights can be selected to detect the drift value of the pressure switch to avoid erroneous test results caused by circuit faults.

[0058] In a specific implementation, in the parallel circuit formed by the first indicator light 5, the second indicator light 6, the third indicator light 7 and the fourth indicator light 8, a unidirectional conducting diode is arranged on each branch.

[0059] Among them, Figure 2 As shown in a circuit schematic diagram of a subway vehicle pressure switch drift value measuring device, a unidirectional conducting diode D1 is arranged on a circuit branch of a first indicator light 5, a unidirectional conducting diode D2 is arranged on a circuit branch of a second indicator light 6, a unidirectional conducting diode D3 is arranged on a circuit branch of a third indicator light 7, and a unidirectional conducting diode D4 is arranged on a circuit branch of a fourth indicator light 8.

[0060] Based on this, the unidirectional conducting diode is used to limit the current flow direction in the circuit branch where each indicator light is located, thereby avoiding the problem of false lighting of each indicator light due to circuit backflow, thereby avoiding interference with the drift value detection result of the pressure switch.

[0061] It should be noted that, the pressure gauge 1, air inlet 2, air outlet 3, wiring port 4, first indicator light 5, second indicator light 6, third indicator light 7, fourth indicator light 8, pressure regulating valve 9, detection interface 10, power switch 11, charging port 12 and test light button 13 are integrated on the device display shell surface of the housing shell of the subway vehicle pressure switch drift value measuring device, ensuring that the volume of the subway vehicle pressure switch drift value measuring device is controllable and meets the portability, and the housing shell realizes a sealed package to meet the use requirements of dustproof and drop-resistant. In addition, the above seven-hole plug meets the access requirements of relevant equipment of subway trains, and is used for the subway vehicle pressure switch drift value measuring device to adapt to the subway train pressure switch drift value detection process.

[0062] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0063] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of this specification are not limited by the order of the actions described, because according to the embodiments of this specification, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the embodiments of this specification.

[0064] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] The preferred embodiments of this specification disclosed above are only used to help explain this specification. The optional embodiments do not describe all the details in detail, nor do they limit the invention to only the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the embodiments of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the embodiments of this specification, so that technicians in the relevant technical field can well understand and use this specification. This specification is only limited by the claims and their full scope and equivalents.

Claims

1. A device for measuring drift value of pressure switch for subway vehicles, characterized in that: The device for measuring drift value of pressure switch for subway vehicles comprises: A pressure gauge (1) displays the pressure value of the detected air flow input from the air inlet (2) and output from the air outlet (3); A wiring port (4), one end of which is connected to the pressure switch to be measured, and the other end of which is connected to one end of the second, third, fifth, and sixth female holes of the seven-hole plug; The first indicator light (5), the second indicator light (6), the third indicator light (7) and the fourth indicator light (8) are connected in parallel, and the first indicator light (5) is connected to the other end of the second female hole of the seven-hole plug, the second indicator light (6) is connected to the other end of the third female hole of the seven-hole plug, the third indicator light (7) is connected to the other end of the fifth female hole of the seven-hole plug, and the fourth indicator light (8) is connected to the other end of the sixth female hole of the seven-hole plug; The pressure regulating valve (9) is used to adjust the pressure value of the detected air flow.

2. The device according to claim 1, characterized in that The device for measuring drift value of a subway vehicle pressure switch also includes a detection interface (10), wherein the detection interface (10) receives a corrected air flow of a preset air pressure value and corrects the pressure gauge (1) according to the preset air pressure value.

3. The device according to claim 1, characterized in that The device for measuring drift value of a subway vehicle pressure switch further comprises a power switch (11), one end of the power switch (11) being connected to a power module and the other end of the power switch (11) being connected to one end of the first and fourth female holes of the seven-hole plug.

4. The device according to claim 3, characterized in that The device for measuring drift value of a subway vehicle pressure switch further comprises a charging port (12), wherein the charging port (12) is connected to the power module to charge the power module.

5. The device according to claim 3, characterized in that The power supply module is a direct current power supply with constant voltage and constant current output.

6. The device according to claim 3, characterized in that The device for measuring drift value of pressure switch for subway vehicles comprises: The other end of the first female hole of the seven-hole plug is connected to the pressure switch to be measured, and forms a first circuit with the first indicator light (5), and forms a second circuit with the second indicator light (6); The other end of the fourth female hole of the seven-hole plug is connected to the pressure switch to be measured, and forms a third circuit with the third indicator light (7), and forms a fourth circuit with the fourth indicator light (8).

7. The device according to claim 6, characterized in that The drift value measuring device for the subway vehicle pressure switch also includes a test light button (13), one end of which is connected to the connection points between the power switch (11) and the first and fourth female holes of the seven-hole plug, and the other end is connected to the connection points between the first indicator light (5) and the second female hole of the seven-hole plug, the second indicator light (6) and the third female hole of the seven-hole plug, the third indicator light (7) and the fifth female hole of the seven-hole plug, and the fourth indicator light (8) and the sixth female hole of the seven-hole plug.

8. The device according to claim 1, characterized in that The device for measuring drift value of pressure switch for subway vehicles also includes: In the parallel circuit formed by the first indicator light (5), the second indicator light (6), the third indicator light (7) and the fourth indicator light (8), a unidirectional conducting diode is arranged on each branch.

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