(lifting hydraulic cylinder,produced by Hebei Hengyu company）

lifting hydraulic cylinder are widely used ，because of powerful torque，clever hydraulic energy conversion，simple structure and reliable operation.So our company has designed lifting hydraulic cylinder for our customers.

Introduction to lifting hydraulic cylinder:

If the lifting hydraulic cylinder operation failure, you can start from these aspects to troubleshoot: (1) the hydraulic system control pressure is too low. The throttling resistance in the control line may be too large, the flow valve is improperly adjusted, the control pressure is inappropriate, and the pressure source is disturbed. At this time, the control pressure source should be checked to ensure that the pressure is adjusted to the specified value of the system; (2) Air enters the hydraulic system. Mainly because there is a leak in the system. At this time, check the liquid level of the hydraulic tank, the seals and fittings on the oil suction side of the hydraulic pump, and whether the oil suction filter is too dirty. If so, the hydraulic oil should be replenished, seals and fittings should be treated, and the coarse filter element should be cleaned or replaced. (3) The initial action of the lifting hydraulic cylinder is slow. In the case of low temperature, the hydraulic oil viscosity is large, poor flow, resulting in slow lifting hydraulic cylinder action. The improvement method is to replace the hydraulic oil with better viscosity and temperature performance If the lifting hydraulic cylinder is weak and cannot push the load, please check the internal leakage problem. The internal leakage of the lifting hydraulic cylinder includes the leakage caused by excessive wear of the lifting hydraulic cylinder block seal, the piston rod and the seal cover seal and the piston seal. The cause of sealing leakage between the piston rod and the seal cover is that the seal is wrinkled, squeezed, torn, worn, aging, deterioration, deformation, etc., and a new seal should be replaced at this time. The main cause of excessive piston seal wear is improper adjustment of the speed control valve, resulting in excessive back pressure and improper seal installation or hydraulic oil contamination. The second is that foreign bodies enter the assembly and the quality of sealing materials is not good. The result is that the action is slow and weak, and in serious cases, it will cause damage to the piston and lifting hydraulic cylinder, and the phenomenon of "pulling the lifting hydraulic cylinder" appears. The treatment method is to adjust the speed control valve, and the necessary operations should be done according to the installation instructions.

The repair method of the lifting hydraulic cylinder: the repair of the lifting hydraulic cylinder must use brush plating. This is because this repair method can be carried out on site, and the repair effect is good. In this way, loading and transportation can be eliminated to shorten the repair time and improve work efficiency. In addition, the coating obtained by brush plating has good binding force and will not have obvious boundaries. Moreover, the repair surface has high hardness and good wear resistance.

When the hydraulic oil is not pumped into the lifting hydraulic cylinder, it is necessary to check whether the tubing, oil circuit, especially the hose joint has been blocked, and the relevant oil circuit from the lifting hydraulic cylinder to the pump should be checked in turn and blocked; Check whether the seal between the taper valve and the seat of the relief valve is good; Check whether the solenoid valve spring is damaged or whether the solenoid coil is burned out; Whether the oil circuit is switched is insensitive.

lifting hydraulic cylinder piston rod material selection and technical requirements: (I), because there is no special requirements, so use 45 steel as the piston rod material, the design of the piston rod only withstand pressure stress, so no modulation processing; (ii) The coaxial tolerance of the shaft journal and the outer circle of the mounting piston is not greater than 0.01mm, so as to ensure the coaxial degree of the outer circle of the piston rod and the outer circle of the piston, and avoid the stuck phenomenon of the piston and the lifting hydraulic cylinder, the piston rod and the guide. The vertical tolerance between the end face of the mounting piston and the axis of the piston rod is not more than 0.04mm/100mm to ensure that the piston installation does not produce skew; (iii) The outer circle of the piston rod should pay attention to the roughness; (iv) Because it is operated under low load conditions, surface treatment is omitted.

Answers to some questions about lifting hydraulic cylinder:

Why the cylinder cannot operate normally after the explosion-proof valve is installed?
The pipeline explosion-proof valve is specially designed to prevent pipeline damage and free fall of the cylinder, so there must be back pressure to open. If there is no oil return pressure, or the oil return pressure is too small, and can not adjust the oil return pressure, such a system with explosion-proof valves is more troublesome, it is recommended to add a one-way throttle valve between the cylinder and the tank to establish back pressure. If you understand the explosion-proof valve, you can also try to adjust the opening of the valve (that is, the flow of the regulating valve), and adjust the opening to help the valve to open.

How to deal with the surface degreasing process before spraying paint after cylinder assembly, and what degreasing agent is used?
Cylinder painting, generally using the following process (note: the cylinder is best painted, do not spray powder coating, because the powder coating curing temperature is high, will lead to sealing defects and oil leakage) : Pre-degreasing - degreasing - washing - washing - pickling - washing - washing - table adjustment - phosphating - washing - washing - drying - polishing - spray primer - spray paint degreasing agent generally use neutral or weak alkaline degreasing agent, phosphating liquid generally use zinc phosphating liquid.