Hydraulic cylinder processing products of the main components
Cylinder is the main component of hydraulic cylinder, single pillar, hydraulic support, gun tube and other products, and its processing quality directly affects the life and reliability of the whole product. Cylinder processing requirements are high, the internal surface roughness requirements are Ra0.4 ~ 0.8&um, the coaxiality, wear resistance requirements are strict. The basic feature of cylinder is deep hole processing, which has always troubled the processing personnel.
Due to the residual compressive stress on the surface of the surface layer, the rolling machining is helpful to seal the small cracks on the surface and prevent the expansion of erosion. Thus, the corrosion resistance of the surface can be improved, and the fatigue crack can be delayed or expanded, and the fatigue strength of the cylinder can be improved. By rolling forming, a cold working hardening layer is formed on the rolling surface, which reduces the elastic and plastic deformation of the contact surface of the grinding pair, thereby improving the wear resistance of the inner wall of the cylinder and avoiding the burn caused by grinding. After rolling, the reduction of surface roughness value can improve the matching property.
Hydraulic cylinder is the most important part of construction machinery, the traditional processing method is: broaching cylinder block - fine boring cylinder block - grinding cylinder block. The rolling method is: broaching cylinder block - fine boring cylinder block - rolling cylinder block, the process is 3 parts, but the time is compared: grinding 1 meter of the cylinder block is about 1-2 days, rolling 1 meter of the cylinder block is about 10-30 minutes. Input comparison: grinding machine or quilting machine (tens of thousands - millions), rolling knife (ten thousand - tens of thousands). After rolling, the surface roughness of the hole decreases from RA3.2-6.3um before rolling to RA0.4-0.8&um, the surface hardness of the hole increases by about 30%, and the fatigue strength of the inner surface of the cylinder increases by 25%. If the service life of the cylinder is only considered, it is increased by 2 to 3 times, and the efficiency of the boring and rolling process is about 3 times higher than that of the grinding process. The above data show that the rolling process is efficient and can greatly improve the surface quality of the cylinder.
After the cylinder is rolled, there is no sharp tiny edge on the surface, and long-term motion friction will not damage the seal ring or seal, which is particularly important in the hydraulic industry.
Hydraulic cylinder is an executive element that converts hydraulic energy into mechanical energy in hydraulic system. The fault can be basically summarized as hydraulic cylinder misoperation, inability to push the load and piston slip or crawl. Due to the failure of the hydraulic cylinder, the phenomenon of equipment shutdown is not uncommon, so we should pay attention to the fault diagnosis and maintenance of the hydraulic cylinder.
1, forklift fork drop speed is too fast
Fault check: Throttle stuck in open position or inverted
Troubleshooting: Reinstall throttle valve
2. The free slide of the lifting cylinder of the forklift is too large or the inclination Angle of the tilting cylinder is too large
Fault check: the leakage in the reversing valve stem is too large, and the tilting cylinder piston seal ring fails and leaks
Troubleshooting: Replace the stem or replace the seal ring
3, hydraulic cylinder rod with oil
Fault check: The oil seal is damaged
Troubleshooting: Replace the oil seal
4, hydraulic system noise (cylinder movement is not smooth)
Fault check 1: The intake pipe is blocked
Troubleshooting: dredge the tubing and replace the oil
Fault check 2: There is air in the system
Troubleshooting: Remove from vent hole
Fault check 3: gear pump bearing wear or gear pump side plate wear
Troubleshooting: Replace gear pump bearings or side plates
Air discharge method in the hydraulic system of forklift truck: lift the lifting cylinder, inject the hydraulic oil to the oil level specified in the scale, make the forklift load rated load about 1/10, loosen the air release bolt on the lifting cylinder, operate the lift cylinder to lift and drop several times, until there is no air bubble at the air release plug, and then tighten the air release plug.
