The rapid development of the automotive industry has led to the development of intelligent test equipment and testing services for automotive powertrains. The global market size of engine test equipment is expected to be 15.413 billion yuan in 2025 (CAGR ≈ 7.54% in 21-25 years), and 5.539 billion yuan in China, with considerable market size space. Among them, cold testing, as an important means of engine quality testing, has attracted more and more attention from major OEMs and capitals, and is becoming a research hotspot in the automobile industry at home and abroad.
1. The principle of cold test
Engine cold testing is a method used to test the assembly quality of an internal combustion engine, as the name suggests, the engine is tested under the premise that the engine is not ignited. The cold test bench drags the engine's flywheel or crankshaft through the motor to reach the test speed, and then the engine is quantitatively measured and compared with the standard through various sensors in the cold test bench, and the test results are output.
Specifically, when an engine is inspected using cold test technology, the engine does not require fuel to operate and no coolant to cool. The engine under test enters the test bench and clamps the engine's intakes, exhausts and electrical adaptation interfaces through a cylinder or hydraulic cylinder drive clamp. With claws or other clamping mechanism automatically clamp the engine's flywheel or adapter, the test bench's servo motor drives the engine to rotate at different speeds, at the same time, the test system through the data acquisition card simultaneously from the engine intake, exhaust port, clamping mechanism torque sensor and the main oil outlet pressure sensor to collect data, the collected test data through the test bench special software analysis, and then the analysis results and the test bench has been set to compare the limit value, so as to determine whether the engine is correctly assembled.
Figure 1 Cold test detection process
Fig. 2 Cold test bench (Florich bench)
2. Comparison of cold test and hot test
The essence of engine testing stems from the appeal to the quality of the whole machine assembly, which is to detect the real working conditions of the engine as much as possible. According to the test principle, that is, whether the engine is ignited most intuitively, the engine test is divided into cold test and hot test. It is worth noting that cold test and hot test technology is mainly for the engine off-line test in the field of fuel vehicles, excluding the test of the whole vehicle, transmission and other objects, in the field of new energy, especially in the battery production process, there is no cold test and hot test, but there is also an offline test EOL (End of Line testing).
▲Figure 3 Comparison between cold test and hot test of engine
Compared with the traditional engine hot test equipment, the engine cold test equipment has advantages in terms of cost, environmental protection, safety, efficiency, accuracy and other indicators.
(1) Through the comparison of Figure 3, it can be seen that the cold test time is short, there is no pollution, and the coverage test of the five major systems of the two major engine mechanisms can be realized, and the advantages are obvious.
(2) There is no cooling water medium in the cold test process, and the engine cooling system (waterway leakage, pump working status, etc.) cannot be monitored under cold test conditions. The cold test cannot monitor the engine problems in some hot engine cases, such as power output, crankcase pressure, crankcase gas series and other issues; the cold test cannot monitor the tiny leakage of the oil circuit. For spark plug gaps, ceramic cracking, etc., it is impossible to accurately monitor, and it is necessary to strengthen the quality control of part quality.
3. The current development trend of cold testing
(1) The development of cold test technology relies on the sensor detection accuracy and DAQ data acquisition board accuracy to improve, the current mainstream torque sensor production plant is HBM T10f series non-contact sensor, pressure sensor is DL-system GmbH manufacturing, temperature sensor is PT100 resistance temperature rise sensor and Optis/IFM, vibration sensor for PCB company manufacturing. The improvement of sensor accuracy will greatly improve the accuracy of defect capture. THE DAQ data acquisition card comes from NI.
(2) With the development of big data technology, the cold test process not only needs to pay attention to the test process but also pays attention to data processing and diagnostic analysis, and the data curve collected by the test combined with big data technology for trend estimation and judgment will be the core key to the next stage of development.
4. Investment analysis for cold test enterprises
Foreign mainstream automobile countries have widely used cold test equipment, domestic cold test still has a lot of space, the reason is: compared with overseas mainstream auto countries domestic cold test accounted for small + master the cold test technology of the company less domestic cold test popularization is limited. Specifically:
●Cold test with high efficiency and environmental protection and other advantages, gradually become the mainstream;
●The domestic hot test is mainly limited by the lack of cold test technology, and with the technological breakthrough of domestic enterprises such as Huayi Technology and Lianji Technology, the domestic alternative space for cold test is promising.
The market size of automotive powertrain test equipment is 3.831 billion yuan in 2021 and 5.539 billion yuan in 2025, according to the proportion of China's automobile sales in the world, the market size of automotive powertrain testing services will be 4.09 billion yuan in 2021 and 6.14 billion yuan by 2025.
If domestic test equipment enterprises want to completely break the monopoly, they need to carry out from the following aspects:
1) Give full play to the advantages of local suppliers, adopt the strategy of test equipment suppliers + test equipment service providers, consider the equipment life cycle curve (generally seven years), and realize the management services of the whole life cycle.
2) In-depth cooperation with domestic OEMs, combine equipment testing + big data evaluation, fully tap the potential value of test data, feed back the quality inspection process, and ensure the stability and data accuracy of the equipment in the test process in an all-round way.
3) Strengthen cooperation with parts suppliers, in view of the bottleneck of cold testing technology, can discuss the cooperation mechanism with suppliers, can intercept in the upstream, and provide a full range of testing solutions for vehicle OEMs. Strengthen cooperation with OEMs, explore unified quality inspection standards, and open up testing services for the whole industry chain.
4) Expand the test service business, with the development of new energy electric vehicles, further explore pure electric vehicle powertrain testing services, battery pack testing services, provide testing services for downstream customers powertrain product development and design, and provide engineering testing and analysis verification for the design, development and improvement of automotive powertrain performance, function and quality.
About the Author: Nuts
Senior engineers in luxury car companies switched from engine testing to battery testing.
At present, he focuses on the research of battery testing technology.
I hope to work with you to "electrify, to the future"!