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Cylinder test method

Source:Jiangyin Eternal Heavy Industry Co.,Ltd. Release time:2021-08-30 15:02:13 Author:803

1. Trial operation of hydraulic cylinder:

The hydraulic cylinders of each station are in place, the hydraulic cylinders to be tested are connected, the ball valve is opened, the oil pump is started, the condition of each key part is checked, the electro-hydraulic reversing valve is operated to change the direction, and the hydraulic cylinder starts pre-operation.

2. Starting pressure of hydraulic cylinder:

Pre-connect the pressure gauge to the working chamber to be tested, manually visually inspect the digital display electronic pressure gauge. After operating the electro-hydraulic reversing valve, slowly adjust the control handle of the relief valve until the hydraulic cylinder starts to start. Then observe and record the pressure. Let the cylinder run for 2-3 cycles to exhaust. The number of cycles can be adjusted. It is mainly to observe whether the cylinder has long-stroke crawling, severe jitter, and whether the short-stroke hydraulic cylinder is stuck in parallel operation and other abnormal conditions.

3. Pressure test of hydraulic cylinder:

The pressure test also includes a static pressure holding test. After the tested hydraulic cylinder reaches the end of its stroke, the medium and high pressure are automatically switched. The ultra-high pressure pump automatically continues to pressurize the working chamber, and supplies oil smoothly and effectively through the pre-adjusted relief valve. At this time, the position of the electro-hydraulic valve is maintained after reversing, and the high-pressure plunger pump continues to pressurize 1 -2min (The pressure is 1.25 or 1.5 times the working pressure).

4. Leakage test of hydraulic cylinder:

1. External leakage: During the first, second, and third tests, check the welding points on the outside of the hydraulic cylinder, the piston rod and the guide sleeve, the guide sleeve and the cylinder liner, the joints and flange connections on the cylinder block, etc. Whether there is leakage at the seal.

2. Internal leakage: The test method focuses on the third item (pressure holding test in the pressure test): it must be combined with the pressure test, that is, after the continuous pressure stops, the high-pressure system is unloaded and the hydraulic oil is directly returned to the tank. The hydraulic control check valve automatically locks the oil circuit, and the hydraulic cylinder oil cavity maintains pressure. After confirming that there is no leakage in the system oil circuit of the test bench or the natural leakage value of the system, check the pressure drop per unit time for indirect feedback. Eligibility should be based on the actual situation.

5. Hydraulic cylinder buffer test:

Observe the buffer effect when the hydraulic cylinder reaches the two ends, adjust the buffer throttle rod of the cylinder, watch the buffer speed change, manually monitor the impact of the piston and the cylinder end cover, and analyze whether the product needs to be adjusted to be qualified.

6. Hydraulic stroke detection test:

During the above test of the hydraulic cylinder, the effective extension length (longest and shortest) of the piston rod can be measured manually or mechanically during the static pressure holding period. At this time, the results should be recorded and compared with the original design data. To find out whether the stroke of the hydraulic cylinder meets the regulations, and at the same time, the speed of the stroke of the hydraulic cylinder under a certain flow rate can be calculated, and the maximum accuracy per unit time can reach 1mm/sec.

7. Drain the oil after the hydraulic cylinder test:

1)1) After the hydraulic cylinder test is completed, the qualified products are recorded in sequence, and the unqualified products are manually compared with the test results, and necessary processing is made to correct the data or retest.

2) After the test, the hydraulic cylinder must be drained and reset regardless of whether it is qualified or not. After confirming that there is no high pressure, manually switch the hydraulic cylinder oil discharge control button. At this time, no matter where the piston rod is, it will be moved back and forth several times without load. After confirming that the hydraulic oil in the cylinder is basically drained, the piston rod is reduced to the shortest dimension, and the hydraulic cylinder test is ended.