1. Overview of Background Technology
The creep performance of weighing sensors directly affects the measurement accuracy and precision of the whole scale. Therefore, the detection of creep performance is an important indicator that must be strictly controlled in the manufacturing process of all weighing sensor manufacturers. In the actual production process, the detection of creep performance should actually include the minimum static load output recovery, referred to as instantaneous return to zero. Since these two indicators can be completed in one creep test process, the creep test includes the creep and instantaneous return to zero performance tests. In the past ten years, the creep test process has not changed much in the manufacturing of weighing sensors. The small-scale aluminum alloy weighing sensors and the micro weighing sensors used on the human scale mostly use a system composed of portable weights combined with multi-channel acquisition instruments, and manually record data to complete the creep and instantaneous return to zero tests; the large-scale stainless steel and alloy steel weighing sensors have always used comparison, lever, and superposition force measuring machines combined with single-channel acquisition instruments and computers to complete the creep and instantaneous return to zero tests. The above methods have the following disadvantages:
1. The workload of workers is large. Assuming that each person tests 300 20kg weighing sensors per day, and loads and unloads weights once each time, the total weight of the weights moved per day is 1.2t.
2. Low production efficiency. The main reason is that the number of products tested at one time is small, the number of personnel is large, and the waiting time is obvious.
3. Poor test accuracy. The use of multi-channel instruments, manual counting, and comparison force measuring machines will introduce greater errors to the test system, and the accuracy of the test is not easy to guarantee.
4. Difficulty in archiving test data. If the manually recorded data needs to be entered into the computer for archiving and calling, the workload is very large.
5. Slow data collection speed. The instrument is used to collect the data of the weighing sensor. The data collection speed of the test system is slow due to the communication speed limit between the computer and the instrument, the channel switching time, or the backward software used by the computer. Due to the above reasons, all manufacturing companies want to realize the automatic creep test of weighing sensors, and have invested a large number of technical personnel in development. AVIC Electronic Instrument Co., Ltd. finally realized this dream in 2011, and developed a complete set of creep automatic test system and applied it to the production line of aluminum alloy sensors. The system solves the above problems well, and improves the accuracy and efficiency of product creep and zero return tests.
2. Composition of creep automatic test system
The creep automatic test system consists of four parts: load generation equipment, digital acquisition module, computer and control hardware, and acquisition and control software. Creep test automation has been the technical pursuit of enterprises for many years, and it has now been realized. Through this article, we hope to provide a reference for enterprises that are developing the system. With the development of the economy, people continue to pursue high-quality life, which also promotes the rapid development of the weighing industry. The number of weighing sensors supplied has increased year by year. Through the automated production line, the production efficiency and quality of weighing sensors have been improved simultaneously, which has become the common wish of weighing sensor suppliers. The realization of creep test automation is an inevitable trend in the weighing sensor manufacturing industry. In the later stage, there are also automation projects in various processes such as automatic placement machines, automatic angle difference adjustment machines, and intelligent temperature compensation technologies that require all practitioners to work together to overcome.