General principles of hydraulic system fault diagnosis for paper cutter manufacturers
        Correct analysis of failures is the prerequisite for troubleshooting. Most system failures do not occur suddenly. There are always warning signs before they occur. When the warning signs develop to a certain degree, a fault occurs. The causes of failure are various and there are no fixed rules to find. Statistics show that about 90% of the failures in hydraulic systems are caused by poor management. In order to diagnose faults quickly, accurately, and conveniently, it is necessary to fully understand the characteristics and rules of hydraulic faults, which is the basis of fault diagnosis.
        The following principles are worth following in troubleshooting:
      (1) First, determine whether the working conditions and peripheral environment of the hydraulic system are normal. First, it is necessary to find out whether the mechanical part of the equipment or the electrical control part is faulty, or whether the hydraulic system itself is faulty. Claim.
       (2) Area judgment Determine the area related to the failure based on the failure phenomenon and characteristics, gradually narrow down the scope of the failure, detect the components in this area, analyze the cause of the failure, and finally find out the specific location of the failure.
      (3) Grasp the types of failures for comprehensive analysis According to the final phenomenon of the failure, gradually find out a variety of direct or indirect possible causes. In order to avoid blindness, comprehensive analysis and logical judgment must be performed according to the basic principles of the system to reduce the number of suspects Gradually approach, and finally find the fault.
      (4) When verifying the possible cause of failure, generally start from the most likely cause of the failure or the easiest place to test, which can reduce the workload of assembly and disassembly and improve the speed of diagnosis.
      (5) Fault diagnosis is based on operating records and certain system parameters. Establish a system operation record, which is the scientific basis for preventing, discovering, and handling faults. Establish a device operation fault analysis table, which is a high-level summary of experience and helps to quickly judge the fault phenomenon. Make accurate quantitative analysis of failures.
        2.Troubleshooting methods for paper cutter manufacturers
        The traditional method of finding hydraulic system failures on a daily basis is to gradually approach the fault by logical analysis.
        The basic idea is comprehensive analysis and condition judgment. That is, the maintenance personnel judge the cause of the failure based on experience through observation, listening, touch and simple tests and understanding of the hydraulic system. When the hydraulic system fails, there are many possible causes for the failure. The logical algebra method is used to list the possible failure causes, and then make logical judgments one by one based on the principle of easy-to-fail, and then approach each item one by one, and finally find out the cause of the failure and the specific conditions that caused it.
        In the process of fault diagnosis, maintenance personnel are required to have basic knowledge of hydraulic system and strong analysis ability to ensure the efficiency and accuracy of diagnosis. However, the diagnosis process is cumbersome and requires a large number of inspections and verifications, and it can only be analyzed qualitatively. The cause of the diagnosis is not accurate enough. In order to reduce the blindness and experience of system fault detection and the workload of disassembly, the traditional fault diagnosis methods are far from meeting the requirements of modern hydraulic systems. With the development of hydraulic systems toward large-scale, continuous production, and automatic control, a variety of modern fault diagnosis methods have emerged. Such as the iron spectrum technique, the number, shape, size, composition and distribution of various abrasive particles that can be separated from the oil can be used to timely and accurately determine the wear position, form, and degree of components in the system. In addition, quantitative pollution analysis and evaluation of hydraulic oil can be performed to achieve online detection and fault prevention.

        Expert diagnosis based on artificial intelligence, which uses computer to imitate the methods used by experienced experts in a certain field to solve problems. The failure phenomenon is input into the computer through the man-machine interface. The computer can infer the cause of the failure based on the input phenomenon and the knowledge in the knowledge base, and then output the cause through the man-machine interface, and propose a maintenance plan or preventive measures. These methods bring broad prospects to hydraulic system fault diagnosis and lay the foundation for hydraulic system fault diagnosis automation. However, most of these methods require expensive detection equipment and complex sensor control systems and computer processing systems. Some methods are difficult to study and are generally not suitable for field promotion.