News

the dynamic pictures of Yangzhou Yinhe Machinery Co,. Ltd.

1) Before the hydraulic cylinder is disassembled, the hydraulic circuit should be depressurized. Otherwise, the high-pressure oil in the circuit will be quickly sprayed when the tubing connection with the cylinder is loosened. When the hydraulic circuit is depressurized, loosen the handwheel or pressure adjusting screw at the overflow valve to unload the pressure oil, then cut off the power or cut off the power source to stop the hydraulic device. 2)When disassembling, damage to the top of the piston rod, the threads of the piston rod, the surface of the piston rod, and the inner wall of the cylinder liner should be prevented. In order to prevent bending or deformation of the elongate member such as the piston rod, a balance of wood support is applied when placing. 3)Disassemble it in order. Because the structure and size of various hydraulic cylinders are not the same, the disassembly sequence is slightly different. Generally, the two-chamber oil should be drained, then the cylinder head removed, and finally the piston and piston rod removed. When disassembling the cylinder head of a hydraulic cylinder, special tools are used for the card key or snap ring of the internal card key type connection. The use of a flat spatula is prohibited. For the flange type end cap, it must be screwed out. Hammering or hard hammering is not allowed. When pistons and piston rods are difficult to withdraw, they must not be forcibly ejected. They should be identified and disassembled. 4)Before and after unloading, try to create conditions to prevent the parts of the hydraulic cylinder from being contaminated by dust and impurities around it. For example, it should be done in a clean environment as far as possible; all parts should be covered with plastic cloth after disassembly, and do not cover with cotton cloth or other working cloths. 5) After the cylinder is disassembled, it must be checked carefully to determine which parts can be used continuously, which parts can be used after repairs, and which parts must be replaced. 6)The parts must be carefully cleaned before assembly. 7) Properly install the seals throughout. ① When installing the O-ring, do not pull it to the degree of permanent deformation, do not roll the edge of the package, or it may leak due to the formation of a twist. ② When installing the Y-shaped and V-shaped sealing rings, pay attention to the installation direction to avoid oil leakage due to the installation. For Y-ring seals, the lip of the Y-ring seals against the pressure of the oil chamber. In addition, the Yx-ring seal must also be used to distinguish between the shaft and the hole. Do not install the wrong seal. The V-shaped seal ring is composed of a support ring, a seal ring and a pressure ring which are different in shape. When the pressure ring presses the seal ring, the support ring can cause the seal ring to come into shape and seal. When installing, the opening of the seal ring should face Pressure oil chamber; when adjusting the pressure ring, it should be limited to no leakage, and it must not be too tight to prevent excessive seal resistance. ③ If the sealing device is fitted with a sliding surface, it should be coated with an appropriate amount of hydraulic oil. ④ After the removal of the O-ring and dust ring should be completely replaced. 8) Special wrenches should be used when the threaded couplings are tightened, and the torque should meet the standard requirements. 9) After the piston is assembled with the piston rod, it is necessary to measure whether the coaxiality and the straightness over the entire length are excessive. 10)After assembly, the piston assembly should be free from blockage and uneven resistance. 11)When the hydraulic cylinder is installed on the mainframe, a seal ring must be added between the inlet and outlet port joints and fastened to prevent oil leakage. 12) After assembling as required, several reciprocating motions should be performed under low pressure to eliminate the gas in the cylinder.

10 steps introductions of the hydraulic cylinder design are as the following: 1. Select the structure of the cylinder head and calculate the connection strength between the cylinder head and the cylinder. 2. The type and structure of the hydraulic cylinder are selected according to the motion requirements of the host. 3. Design buffers, exhaust, and dust-proof devices if necessary. 4. The piston and piston rod diameters are determined based on the hydraulic cylinder's working load and the selected working fluid pressure. 5. According to the speed of the hydraulic cylinder, the diameter of the piston and piston rod, determine the flow of the hydraulic pump. 6. Select the cylinder material and calculate the outside diameter. 7. Draw hydraulic cylinder assembly drawings and part drawings. 8. According to the working stroke requirements, determine the maximum working length L of the hydraulic cylinder, usually L>=D, D is the diameter of the piston rod. As the piston rod is slender, the longitudinal bending strength check and the stability calculation of the hydraulic cylinder should be performed. 9. To master the general design steps of the hydraulic cylinder, first of all, to master the original data and design basis, including: the use of the host and working conditions; structural characteristics of the working mechanism, load conditions, stroke size and motion requirements; selected hydraulic system pressure and flow; the current state of materials, accessories and processing; relevant national standards and technical specifications, etc. 10. According to the external load acting on the hydraulic cylinder, such as gravity, the frictional force of the external mechanism, the inertial force and the working load, the change law of the load of the hydraulic cylinder at each stage of the stroke and the power value that must be provided are determined.

The rolling steel tubes are mainly used in cutting and rolling, and a wide range of tools are used in machining. Most of these cutters can hold two to eight indexable inserts. At the rear of the cutters are rolling tools with four to fifty rollers. The rolling tube and polyurethane cushions are shock-resistant. In the actual processing, it can be divided into two types, one is boring, mirror rolling one feed to complete the processing; the other is to carry out boring first, and then the next processing. If we want to use rolling processing, we mainly use cold plasticity of metal at room temperature to perform pressure finishing. The rolling tool will exert a certain pressure on the surface of the workpiece, so that the surface metal of the workpiece will generate a plastic flow and fill in the valley of the original residual trough, and the surface roughness of the workpiece will be reduced. The use of roller barrels is mainly based on the method of rolling, mainly through the process of broaching cylinders, boring cylinders, and rolling cylinders. Of course, this non-cutting process can not only improve the roughness of the workpiece surface, correct roundness, but also improve the hardness of the workpiece surface and eliminate the force deformation. This process can also provide residual stress layers after processing, increasing fatigue strength by 30%.

Nowadays, the 45 steel pipes commonly used in the domestic construction machinery industry have a high carbon content, and the carbon equivalent reflecting the welding performance is relatively high. In the welding process, measures such as preheating, post-weld insulation and post-weld heat treatment must be adopted to eliminate welding defects [ 1]. In the actual production process, due to the limitations of the structure and processing technology of the hydraulic cylinder barrel, many times these heat treatment requirements cannot be met, and inevitably, more welding defects are generated in the welded portion of the hydraulic cylinder barrel. Many of the failures of the construction machinery and the quality feedback of the user feedback are all related to the welding position of the cylinder of the hydraulic cylinder. With the rapid development of China's construction machinery industry, heavy-duty truck cranes, pump trucks and other construction machinery have become increasingly demanding on the strength, toughness, and welding performance of cylinders of hydraulic cylinders. The 45-steel pipe is a general structural steel and belongs to medium carbon steel. Compared with the 35-steel pipe, the purpose of increasing the strength of the steel pipe is simply by increasing the carbon content. However, due to the increased carbon content of this material, the welding performance is also reduced. The yield strength of Q345B alloy steel pipe, the chemical composition (mass fraction) of Q345B steel pipe and 45 steel pipe after breaking 0.26~0.35017~0.37 Si Mn PS 1.12~1.330.004~0.0100.009~0.012~0.035≤0.035 Q345B45 material C0.16 ~ 0.190.42 ~ 0.50 elongation and impact absorption work, are close to the 45 steel, fully able to meet the car crane using the Q345B alloy steel pipe to replace 45 steel production truck crane hydraulic cylinder cylinder test validation. Through theoretical analysis and tests, the mechanical properties and welding performance of the material were compared with that of the 45-steel pipe; and the material was used to produce a batch product, which was mounted on a truck crane and subjected to a working condition test. The verification results show that the use of Q345B alloy steel pipe instead of 45 steel pipe production truck crane hydraulic cylinder, can fully meet the requirements of the use of truck cranes, it reduces the hydraulic cylinder welding defects by more than 50%, improve the cylinder tube off the long rate guarantees the toughness of the cylinder and reduces the risk of brittle fracture of the cylinder, thus greatly improving the safety and reliability of the hydraulic cylinder. Note: In China, Q345 can also be called 16MN, which is the same material as ST52 in German Standard.

We have attended the 2013 PTC exhibition in Shanghai during 28th to 31th Oct. Our booth is located at E1 L16.