1. The working principle of hydraulic jacks
The working process of the lifting jack is mainly to absorb oil, discharge oil, and maintain pressure. The advanced hydraulic jack has a safety valve, which can protect it from overloaded work, so that the equipment will not be damaged or hurt people. When the control handle moves upward and drives the piston to work, the volume inside the manual pump increases and a small range of vacuum occurs, which prompts the oil discharge check valve to close. At this time, the hydraulic oil in the oil tank will pass through the pipeline and the oil suction check valve after being subjected to atmospheric pressure. Flow to the hand pump, this process is oil suction. When the control handle moves down and drives the piston to work, the oil suction check valve is closed, and the hydraulic oil in the manual pump opens the oil discharge check valve through the pipeline to the hydraulic cylinder, so that the piston overcomes the external force and moves upwards. The process is to drain the oil. When the piston in the hand pump is repeatedly moved up and down by the handle, the hydraulic oil in the hydraulic cylinder increases continuously, thereby pushing the heavy object to rise. When the piston of the hydraulic cylinder rises to the highest, the excess hydraulic oil will return to the oil tank through the overflow channel, and can no longer push the weight to rise. During the lifter jack working process, the shut-off valve is in the closed state. When the piston in the hydraulic cylinder is lowered, the valve is opened, and the hydraulic oil will flow to the oil tank through the shut-off valve under the action of gravity.
2. Advantages of hydraulic jacks
(1) The entire hydraulic transmission equipment of the jack lifter is small in size and compact in structure, the force is balanced evenly, and the internal load curve changes relatively smoothly.
(2) Hydraulic jacks are relatively easy to achieve overload protection, that is, to achieve protection by setting safety valves during the working process. At the same time, the hydraulic equipment can automatically lubricate, which ensures that the equipment has a long service life.
(3) This kind of hydraulic transmission does not require separate energy during use, and can be used repeatedly until the hydraulic oil reaches the specified replacement work cycle, which generally has a long working cycle.
3. Disadvantages of hydraulic jacks
(1) There are relatively high requirements for the temperature of the oil in the process of hydraulic jacks. When the temperature changes, the overall viscosity of the liquid changes, and the equipment cannot be used in places with frequent temperature changes. During use should be avoided as much as possible.
(2) In order to prevent oil leakage, the relevant performance can reach the index, the workmanship of hydraulic components has very strict requirements, and the manufacturing process is relatively complicated.