To effectively analyze and maintain hydraulic press malfunctions, it's crucial to first understand the working principle of the hydraulic press. This allows for quick and effective judgment of the press's issues when they arise. Below is a detailed explanation of the working principle and structure of the hydraulic press.

Hydraulic presses are composed of mechanical, hydraulic, and electrical components, thus their malfunctions can be quite varied. A single fault may be caused by numerous factors, so analyzing hydraulic system failures in hydraulic presses requires an understanding of the hydraulic system schematics. One must have a general grasp of the functions of each component in the schematics, then analyze and judge based on the fault phenomena. For faults caused by many factors, it is necessary to analyze each cause individually, grasp the main contradiction, and only then can the issue be effectively resolved and eliminated.

Understanding the flow of hydraulic components and piping within a hydraulic system of a hydraulic press is challenging for outsiders, thus posing significant difficulties for analysis and diagnosis. Consequently, technicians must possess strong analytical and fault-judging skills. They must identify the root causes and locations of malfunctions within the complex relationships of mechanics, hydraulics, and electronics, and promptly and accurately rectify them.

A. Simplified Fault Diagnosis Method:

The Simplified Fault Diagnosis Method is currently the most widely adopted approach. It relies on the repair personnel's personal experience, using simple instruments to objectively understand the system's operation by employing methods such as asking, observing, listening, touching, and smelling, based on the faults that arise in the hydraulic mechanical system. This involves analysis, diagnosis, and identification of the cause and location of the fault. The specific practices are as follows:

(1) Inquire with the equipment operator to understand the operational status of the equipment. This includes: whether the hydraulic mechanical system of the oil press is functioning properly; if there are any abnormal phenomena in the hydraulic pump; the timing and results of hydraulic oil cleanliness testing; the cleaning and replacement status of the filter cores; whether the hydraulic components were adjusted before the failure occurred; if any sealing elements were replaced; the abnormal phenomena that occurred in the oil press system before and after the failure; what previous failures the system had experienced and how they were resolved, etc., which should be investigated one by one.

(2) Observe the actual operation of the hydraulic press system, checking for any issues with system pressure, speed, oil, leaks, and vibration.

Listen to the sound of the hydraulic press system, such as impact noises; pump noise and abnormal sounds; to determine whether the hydraulic mechanical system is operating normally.

(4) Determine the working condition of moving parts by feeling the oil temperature, listening to vibrations, and observing the tightness of the crawling and connection areas.

In summary, the Simplified Diagnostic Method is merely a simple qualitative analysis, which is highly practical for rapid judgment and fault elimination.

Hydraulic Press System Schematic Analysis Method:

Analyze the hydraulic transmission system's failures based on the hydraulic press system diagram, identify the location and cause of the failures, and propose methods to eliminate them. The hydraulic press system diagram analysis method is widely used by engineering technicians. It requires technicians to have a basic understanding of hydraulic knowledge, be able to interpret hydraulic mechanical system diagrams, and know the names and functions of the components represented by various symbols. They should also have a certain understanding of the principles, structures, and performance of the components.

With such a foundation, it's easy to analyze and judge malfunctions by referring to the action cycle table. Therefore, thoroughly studying hydraulic fundamentals and mastering the hydraulic schematic is a powerful assistant for fault diagnosis and elimination, as well as the basis for other fault analysis methods. It is essential to grasp them diligently.