Air tightness testerThe application of power supply in automotive electronics industry
Generally speaking, the process requirements for the sealing test of automobile connectors by auto parts companies are as follows:
1. Tightness test: it is required to test the tightness of the connector under vacuum or positive pressure. Generally, it is required to test the tightness of the connector under 10KPA to 50kPa positive pressure or negative pressure. The leakage rate of the test product shall not exceed 1cc / min or 0.5cc/min if higher requirements are required. It is a qualified product
2. Withstand voltage test: withstand voltage test is divided into negative pressure test and positive pressure test. It is required to select an accurate proportional control valve group and vacuum the product according to a certain vacuum rate from the initial pressure value of 0. The vacuum time and the proportion of vacuum degree can be adjusted. For example, set the vacuum extraction to - 50kPa, and the extraction rate is 10KPA / min. The difficulty of this test lies in the requirementsAir tightness testerOr the leak detector can set the initial pressure of negative pressure value, such as starting from 0. Of course, it can also be required, such as starting from - 10KPA, and the extraction rate can also be set and changed. As we all know, the sealing tester or air tightness tester is equipped with manual or electronic pressure regulating valve. The pressure can only be adjusted according to the set pressure. The starting pressure starts from 0. The ability of vacuumizing depends on the vacuum source (vacuum generator or vacuum pump). The speed of vacuumizing after the vacuum source passes through the pressure regulating valve is fixed, That is to say, it can only extract from 0 pressure to the fixed pressure set by the pressure regulating valve instantaneously, and it does not have the ability to control the ratio of extraction pressure and time. The principle of positive pressure withstand test is similar to that of negative pressure withstand test, that is, to set the initial pressure of positive pressure at any pressure, such as 0 pressure or 10 kPa, the gradient of pressure rise, that is, the slope can be set, such as 10 kPa / min: the test requires that the pressure rise is proportional to the time and can be adjusted.
3. Burst test (burst test): it can be divided into negative pressure burst test or positive pressure burst test. The product is required to break instantly when it is vacuumed or pressurized to a certain pressure range, and the breaking pressure needs to be recorded. The difficulties are as follows气密性测试仪The negative pressure of extraction should meet the second test requirement, the pressure rate can be adjusted, and the pressure blasting should be completed within the set range. That is to say, blasting below or above this range does not meet the product test requirements, and the test pressure at this blasting point needs to be recorded. In the actual test, this measurement needs to have an anti riot device. The usual anti riot device is to place the test workpiece in a pressure resistant stainless steel cylinder, the test workpiece needs to be sealed, and the stainless steel cylinder of the outer cover needs to be set with a high pressure relief valve to ensure safety. When the explosion occurs, the fragments of the connector are scattered inside the pressure resistant stainless steel cylinder, which will not cause injury to personnel. As you can see from the above analysis,气密性测试仪Generally, it is necessary to design three different devices to complete the seal leakage test, which needs to be completed with the forming leak detector and fixture system. The pressure test needs to increase the proportional control valve group, and accurately set the proportional relationship between pressure value and time. The burst test requires that the product burst within a certain range, and the burst value should also be recorded. If the three systems are integrated, it is a more complex system engineering. Of course, the three tests often require comprehensive completion. The initial pressure value can be set arbitrarily, and the rate of pressure increase or decrease can be adjusted. When the pressure increases or decreases to a certain value and reaches the set range of blasting, the product will explode, and the blasting pressure will be recorded. If the pressure increases or decreases to a certain value, the seal leakage test will be conducted if the product does not explode, and the leakage rate or pressure change per unit time of the seal test will be recorded. After the test, the test results need to be able to be stored for quality traceability. It is required that all test data can be traced and stored and uploaded according to the format of test requirements, so as to facilitate quality analysis and quality control. For the sealing leakage detection industry, these European and American automobile companies have specific requirements for the leakage test: before the test, the barcode of the workpiece needs to be scanned and recorded, and after the test, the barcode should correspond to the specific date and time and other test results.
4. Quantitative test analysis of air tightness tester for products without air filling hole
For products without holes, a profiling cavity can be made on the outside of the product, and the quantitative air tightness detection instrument can be used to detect the size leakage of the product end.气密性测试仪The internal principle of the device is to open the charging valve first, and charge the compressed air with fixed pressure into the reference volume of the instrument. After the reference volume of the instrument is filled with a certain amount of pressure, the charging valve is closed, the test valve group is opened, and the pressure of the reference volume is released into the test chamber. If there is a big leak in the product, then the pressure of the reference volume of the instrument will drop quickly. If it exceeds the limit value set by us, it will give an alarm. If the product has a small leak, then the air pressure of the reference chamber of the instrument will drop very slowly. After maintaining the pressure, the small leak of the product can be detected in the test process, and the accuracy of 0.1cc/min can be measured (the display resolution of the instrument is 0.01cc/min).
This article is based on the ten years of hiruisi Automation Technology Co., Ltd. (www.hairuisi. CN), focusing on IP protection level test equipment; R & D, production and sales of waterproof testing equipment, air tightness testing equipment and sealing testing equipment