The working and mechanical structure principle of universal testing machine

The working and mechanical structure principle of universal testing machine:

The motor drives the oil pump and sends the hydraulic oil in the oil tank to the oil delivery valve through the oil pump, and then enters the oil cylinder through the oil valve. The main part of the equipment is supported by an adjustable height bracket [frame, screw and moving beam (lower jaw seat) Composition] and working frame [composed of working cylinder, piston, table, bracket and upper beam (upper jaw seat)]. Its working principle is: the high-pressure oil pump supplies oil to the working oil cylinder, and the piston moves to push the platen and the upper beam (upper jaw seat) upward to perform the tensile or compression test of the sample. The tensile test is performed between the upper beam and the moving beam of the main machine, and the compression test is performed between the table and the moving beam of the main machine. The adjustment of the test space is achieved by the driving mechanism (elevating motor, sprocket, chain, etc.) driving the double-screw synchronous rotation to move the moving beam up and down.

The force measuring mechanism is designed according to the Pascal principle. The force-measuring cylinder connected to the working cylinder is equipped with a force-measuring piston. The ratio of the force-measuring piston to the working piston cross-section has become a fixed value after verification by the testing machine. The test force acting on the force-measuring piston is proportional to the two cross-sectional areas of. When the oil pressure acts on the force measuring piston, the force measuring piston moves down through the transmission mechanism to cause the force measuring shaft to drive the swing rod and thallium to generate displacement. The magnitude of the angular displacement is proportional to the magnitude of the test force applied to the force measuring piston And push the push rod to make the dial pointer act on the test force value of the test piece.
The installation method of the test machine: set out the samples according to the instructions, lay the foundation, maintain it for about 7 days, then put the test machine in place, wear the anchor screws, grouting, etc. After the grouting is dry, use the random delivery Oblique iron adjusts the level of the machine. Generally, the level of the main machine is relatively low. If it is as large as possible, remove all parts of the binding. The force machine requires high, especially the left and right level. The specific method is: turn the rubber at the swing rod back to swing the swing rod, lift the force measuring piston to see if the lever swings left and right, adjust it with a diagonal iron until the lever does not swing vertically, and the swing amplitude can not be too large. If it is too large, you should adjust the same method. The next step is to connect the oil pipe. According to the number of the pipe joint at the factory, connect the oil pipes one by one. When connecting, pay attention to whether the O-ring is installed in place, plus hydraulic oil to three-thirds of the oil gauge Do not use too much in the two places. Unscrew the inner hexagon plug at the rear of the oil pump to drain the air of the oil pump (the plunger pump produced by the new Shanghai high-pressure oil pump does not need to exhaust air), and connect it to the power See if the motor is working normally and whether the direction is wrong, then start the oil pump, raise and lower the cylinder two to three times, and drain the air in the oil pipe. If it is a hydraulic clamp type, the jaws should be clamped and loosened many times. Part of the air is also exhausted. Lower the crossbeam and press it to see if there is any oil leakage at the tubing interface.

* Note: Pay attention to the oil level height when refueling. The amount of oil is too small. The device cannot work normally. Too much oil will cause hydraulic oil leakage from the working cylinder port.