Hydraulic cylinder mainly includes cylinder, piston rod, cylinder head, piston, which cylinder head used materials will vary depending on the pressure, generally using low pressure castings, low pressure castings using HT300 gray iron, 35.45 steel for high pressure. When the cylinder head itself is the guide sleeve of the piston rod, the cylinder head is cast iron. At the same time, the brass should be melted on the guide surface. Bronze or other wear-resistant material. If the guide sleeve is pressed into the cylinder head, the guide sleeve should be wear-resistant cast iron, bronze or brass.
Wear-resistant cast iron is the common material of cylinder piston, gray cast iron (HT300.HT350), steel, aluminum alloy, piston, piston rod coaxial tolerance should be 0.03mm. The common material of the cylinder is 20.35.45 seamless steel pipe, which has been honed or rolled to reach 00.4μm roughness requirements. No. 20 steel pipe can be used for low pressure cylinder, No. 45 steel pipe for high pressure cylinder.
There are two types of piston rod: solid rod and hollow rod. The solid piston rod material used in welding and heat treatment is 35.45 steel, and the hollow piston rod material is 35.45 seamless steel pipe. After roughing, the quality of the piston rod is adjusted to 229~285HB, and the hardness reaches 45~55HRC after high-frequency quenching.
For hydraulic cylinders, hydraulic oil is also very important. Hydraulic oil is the hydraulic medium in which hydraulic energy is used in hydraulic system. If the cylinder wants to work properly, the hydraulic oil is essential, so the use of the oil is very important. However, it should be noted that before starting, check the oil level and check that the oil circuit is in the correct standby state.
The machine runs at idle speed for 5 minutes to check whether there are bubbles in the oil of the level gauge. If it is a new car or newly replaced hydraulic oil, the bubbles in the oil label are normal at idle. Only after the bubble disappears can the machine work. At the same time, pay close attention to the oil temperature. When the hydraulic cylinder works for a period of time, if the oil temperature is too high, it is recommended to stop the machine to rest, and work again after the oil temperature is normal to improve the service life of the system and oil.
