Wiring harness airtightness test unit

Abstract

The utility model discloses a wire harness airtightness test unit, which is used on a wire harness connector airtightness test device and comprises a pressure sensor, an AD (analog-to-digital) conversion module, an MCU (microprogrammed control unit) and an external computer. The pressure sensor is arranged at a part communicated with the test cavity or in the test cavity so as to output an air pressure analog signal according to the air pressure in the test cavity; the AD conversion module is connected with the pressure sensor so as to receive the air pressure analog signal of the pressure sensor and convert the air pressure analog signal into an air pressure digital signal for output; the MCU is provided with a serial communication module, and the serial communication module is connected with the AD conversion module so as to receive an air pressure digital signal output by the AD conversion module; and an external computer is in communication connection with the MCU so as to receive the air pressure digital signal. According to the utility model, with the cost as low as possible, convenient acquisition of wire harness airtightness test data is realized, thereby facilitating production quality control and analysis of wire harnesses.

Description

Technical Field

[0001] This utility model relates to the technical field of wire harness testing devices, and in particular to a wire harness airtightness testing unit. Background Technology

[0002] Wiring harness connectors used in vehicles, medical devices, and other equipment typically need to be able to isolate a certain amount of moisture. Therefore, during the production process of such wiring harness connectors, an airtightness test is required. This involves creating a test fixture with a test chamber, in which the wiring harness connector is embedded. The test chamber is then sealed, and the area to be tested for airtightness is positioned at the connection point between the test chamber and the outside. Nitrogen or other gases are then injected into the test chamber to pressurize it. A pressure sensor is installed inside the test chamber, or is connected to a pressure sensor via a gas tube. The pressure sensor collects the changes in air pressure within the test chamber. If the preset air pressure threshold is reached, it indicates that the airtightness of the test location meets the predetermined requirements.

[0003] Currently, in most air tightness tests, the air tightness of the wiring harness is determined solely by whether the set air pressure threshold is reached during the test. The real-time data from the pressure sensor is not collected during the test, meaning that the testers cannot obtain the air pressure change data during the test, which is not conducive to quality control.

[0004] The problem of how to conveniently collect wire harness airtightness test data at the lowest possible cost remains to be solved. Utility Model Content

[0005] The purpose of this invention is to provide a wire harness airtightness testing unit, and the technical problem to be solved is to achieve convenient acquisition of wire harness airtightness test data at the lowest possible cost.

[0006] To achieve the above objectives, the solution of this utility model is: a wire harness airtightness testing unit, used on a wire harness connector airtightness testing device, including a pressure sensor, an AD conversion module, an MCU and an external computer;

[0007] The pressure sensor is installed at a location connected to the test chamber or inside the test chamber to output a simulated air pressure signal based on the air pressure inside the test chamber.

[0008] The AD conversion module connects to the pressure sensor to receive the analog air pressure signal from the pressure sensor and converts it into a digital air pressure signal for output.

[0009] The MCU is equipped with a serial communication module, which is connected to the AD conversion module to receive the air pressure digital signal output by the AD conversion module;

[0010] An external computer communicates with the MCU to receive digital air pressure signals.

[0011] Furthermore, an analog switch is provided. The test chamber is provided with multiple chambers, and a pressure sensor is provided for each chamber. Each test chamber can be used to perform airtightness testing on a wire harness connector. The multiple pressure sensors are connected to the analog switch, which is connected to the AD conversion module to form a test unit. The analog switch is used to switch one of the pressure sensors connected to the AD conversion module.

[0012] Furthermore, the test unit has multiple units, and the multiple test units are cascaded to communicate with an external computer. The cascading method is serial port, 485, CAN, or SPI.

[0013] Furthermore, the AD conversion module is integrated into the MCU.

[0014] Furthermore, an operational amplifier is provided between the pressure sensor and the AD conversion module.

[0015] Furthermore, the HX710 chip is used as the aforementioned AD conversion module.

[0016] Furthermore, the airtightness testing device also includes a testing fixture and a pressure device;

[0017] The test cavity is formed on the test fixture. The shape of the test cavity allows the wire harness connector to be partially embedded. After embedding, the test cavity is sealed, and the test part of the wire harness connector is located at the connection between the test cavity and the outside.

[0018] The pressure device is connected to the test chamber and is used to pressurize or evacuate the test chamber by supplying gas into it.

[0019] Furthermore, the external computer is a personal computer.

[0020] The beneficial effects of this utility model after adopting the above solution are as follows: the air pressure in the test chamber is monitored by a pressure sensor, and the air pressure change in the test chamber causes the pressure sensor to generate an air pressure analog signal. The air pressure analog signal is converted into an air pressure digital signal by an AD conversion module, and then transmitted to an external computer by a serial communication module on the MCU. The air pressure change data during the test can then be read and stored by the external computer. This allows for convenient acquisition of wire harness air tightness test data at the lowest possible cost, which is more conducive to the production quality control and analysis of wire harnesses. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the circuit connection of the operational amplifier in this utility model;

[0022] Figure 2 This is a schematic diagram of the pressure sensor connected to the analog switch in this utility model;

[0023] Figure 3 This is a schematic diagram of the pressure sensor connected to the HX710 chip in this utility model;

[0024] Figure 4 This is a schematic diagram of the cascaded test units in this utility model;

[0025] Figure 5 This is a schematic diagram of the communication connection of this utility model.

[0026] Labeling explanation: 1-Pressure sensor, 2-AD conversion module, 3-MCU, 4-Test unit, 5-Analog switch, 6-Operating amplifier. Detailed Implementation

[0027] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] The embodiments of the present invention will be fully described below with reference to the accompanying drawings. It should be noted that the present invention can be implemented in different forms and is not limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0029] A wire harness airtightness testing unit, such as Figure 1-5 As shown, the airtightness testing device for wire harness connectors includes a pressure sensor 1, an AD conversion module 2, an MCU 3, and an external computer.

[0030] The airtightness testing device includes a test fixture and a pressure device. The test fixture is determined according to the specific shape of the wire harness connector and the position to be tested. The test cavity is formed on the test fixture. The shape of the test cavity allows the wire harness connector to be partially inserted. After insertion, the test cavity is sealed, and the part of the wire harness connector to be tested is located at the connection between the test cavity and the outside. The pressure device is connected to the test cavity and is used to supply air to pressurize or evacuate the test cavity. This is a conventional technical means in the field of wire harness airtightness testing.

[0031] The pressure sensor 1 is located in a part that communicates with the test chamber or is located inside the test chamber. The part that communicates means that the pressure sensor 1 can be located in a sealed chamber. The sealed chamber is connected to the test chamber through an air tube. Thus, the pressure sensor 1 can output a simulated air pressure signal according to the air pressure in the test chamber. The model of the pressure sensor 1 is not specifically limited. It can be any type of pressure sensor that can achieve the above function. Specifically, in this embodiment, a piezoresistive pressure sensor with model number XGZP101SB1 is used.

[0032] AD conversion module 2 is connected to pressure sensor 1 to receive the air pressure analog signal from pressure sensor 1 and convert it into an air pressure digital signal for output; the AD conversion module 2 can be integrated into the MCU 3, or an HX710 chip independent of the MCU can be used as the AD conversion module 2.

[0033] The MCU3 is equipped with a serial communication module, which is connected to the AD conversion module 2 to receive the air pressure digital signal output by the AD conversion module 2. An external computer is connected to the serial communication module of the MCU3 to receive the air pressure digital signal. The external computer is a personal computer, and the specific communication protocol between the serial communication module and the external computer is not limited. For example, it can be USB protocol, I2C protocol or SPI protocol, etc.

[0034] To reduce costs in scenarios with multiple test stations, a preferred embodiment also includes an analog switch 5. The type of analog switch 5 is not limited; specifically, a 74HC4067PW analog switch is used in this embodiment. Multiple test chambers are provided, each equipped with a pressure sensor 1. Each test chamber can be used for airtightness testing of one wire harness connector. Multiple pressure sensors 1 are connected to the analog switch 5, which is connected to the AD conversion module 2, forming a test unit 4. The analog switch 5 is used to switch the connection of one of the pressure sensors 1 to the AD conversion module. More preferably, multiple test units 4 are cascaded and communicate with an external computer. Cascading is a conventional technique in the art; signals are transmitted sequentially between the test units 4 and finally to an external computer. During cascading, serial ports, RS-485, CAN, or SPI can be used to achieve communication between the test units, allowing an external computer to process the test data from all test stations.

[0035] In the preferred embodiments, an operational amplifier 6 is provided between the pressure sensor 1 and the AD conversion module 2. The operational amplifier can amplify the weak electrical signal output by the pressure sensor to a sufficient amplitude so that the AD conversion module can accurately perform analog-to-digital conversion. The operational amplifier can also perform signal conditioning operations such as filtering and noise reduction to improve signal quality and ensure that the AD conversion module can receive a clean and accurate signal.

[0036] The above description is only a preferred embodiment of this utility model and is not a limitation on the design of this case. All equivalent changes made based on the key design of this case shall fall within the protection scope of this case.

Claims

1. A wire harness airtightness testing unit, used in a wire harness connector airtightness testing device, characterized in that: It includes a pressure sensor (1), an AD conversion module (2), an MCU (3), and an external computer; The pressure sensor (1) is located in a part that communicates with the test chamber or is located inside the test chamber, so as to output a simulated air pressure signal according to the air pressure inside the test chamber; The AD conversion module (2) is connected to the pressure sensor (1) to receive the air pressure analog signal from the pressure sensor (1) and convert it into an air pressure digital signal for output; The MCU (3) is equipped with a serial communication module, which is connected to the AD conversion module (2) to receive the air pressure digital signal output by the AD conversion module (2); An external computer communicates with the MCU (3) to receive digital air pressure signals.

2. The wire harness airtightness testing unit as described in claim 1, characterized in that: An analog switch (5) is also provided. Multiple test chambers are provided, and a pressure sensor (1) is provided for each test chamber. Each test chamber can be used for airtight testing of a wire harness connector. Multiple pressure sensors (1) are connected to the analog switch (5). The analog switch (5) is connected to the AD conversion module (2) to form a test unit. The analog switch (5) is used to switch one of the pressure sensors (1) to be connected to the AD conversion module.

3. The wire harness airtightness testing unit as described in claim 2, characterized in that: The test unit has multiple units, and the multiple test units (4) are cascaded and communicate with an external computer. The cascading method is serial port, 485, CAN or SPI.

4. The wire harness airtightness testing unit as described in claim 1, characterized in that: The AD conversion module (2) is integrated into the MCU (3).

5. The wire harness airtightness testing unit as described in claim 1, characterized in that: An operational amplifier (6) is provided between the pressure sensor (1) and the AD conversion module (2).

6. The wire harness airtightness testing unit as described in claim 1, characterized in that: The HX710 chip is used as the AD conversion module (2).

7. The wire harness airtightness testing unit as described in claim 1, characterized in that: The airtightness testing device also includes a testing fixture and a pressure device; The test cavity is formed on the test fixture. The shape of the test cavity allows the wire harness connector to be partially embedded. After embedding, the test cavity is sealed, and the test part of the wire harness connector is located at the connection between the test cavity and the outside. The pressure device is connected to the test chamber and is used to pressurize or evacuate the test chamber by supplying gas into it.

8. The wire harness airtightness testing unit as described in claim 1, characterized in that: The external computer is a personal computer.

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