What are the reasons for the damage caused when assembling the hydraulic cylinder?

Installed parts of the scars occurred in the installation of hydraulic cylinder, piston and cylinder head and other parts of high quality, large size, inertia, even if the lifting equipment auxiliary installation, with the provisions of the gap are small, no matter how they will Bijin input , So the end of the piston or cylinder head bump in the cylinder wall when the inner surface, easily cause scars. To solve this problem: for the number of small quantities of small products, the installation of the use of autocratic assembly-oriented tools; heavy, coarse, large hydraulic cylinders, only careful and prudent operation in order to avoid.

Measuring instrument contact caused by the scars are usually used to measure the internal diameter of the cylinder diameter dial gauge, the measuring contact is inserted into the friction side of the cylinder bore wall, the measurement of contact hardness is mostly high wear-resistant hard alloy. In general, the measurement results in small depths of the elongated scratches is minor, does not affect the operational accuracy, but if the measurement head size improper adjustment, measurement of hard-line embedded in the contact will cause more severe scars. The solution to this problem is to measure the length of the adjusted measuring head. In addition, a tapered tape, which is punched only in the measuring position, is attached to the inner surface of the cylinder wall, . Measurement of minor scratches caused by the general use of the old Shabu the back of the horse manure or paper can be wiped away.

On the single piston rod hydraulic cylinder, the left and right chambers of the two chambers are connected to each other, and at the same time are connected with the oil pipeline connected to the hydraulic cylinder is called the differential connection. Which is characterized by reduced thrust, speed increased. When the effective working area of the rod rod cavity is twice the rod cavity, that is, the piston diameter D = d (d is the diameter of the piston rod), the differential connection speed is no difference than the differential connection speed doubled, While the thrust is reduced by half.

On the hydraulic cylinder cushioning, its role and the specific working principle of the buffer device is not difficult to understand. The difficulty is mainly the buffer pressure, especially the maximum buffer pressure calculation. In fact, the hydraulic cylinder in the buffer when there are three kinds of energy in the buffer, after braking by the back pressure chamber (buffer chamber) absorption: ① is the hydraulic energy Ep, its value Ep = p1 A1 Lc (where P1 is the high-pressure chamber Pressure, A1 for the high pressure chamber of the effective pressure area, Lc for the back pressure chamber buffer length). ② is the kinetic energy Em, its value is Em = mv2 / 2 (where m is the quality of all moving parts, v for moving parts of the speed). ③ is the reverse of the friction energy Ef, its value is Ef = FfLc (where Ff for the reverse friction). At this point, three kinds of energy, especially kinetic energy in a very short period of time all the pressure into the back pressure chamber liquid E2, resulting in back pressure chamber pressure, the formation of buffer pressure. E1 = Ep + Em-Ef = E2 = Pc · Ac · Lc (E1 is the total mechanical energy of the high-pressure chamber, that is, the sum of the three kinds of energy), so that the effective pressure bearing area of the back pressure chamber is human, the buffer pressure is pc, So the buffer pressure is pc = E1 / AcLc. In the use of throttle adjustable buffer device, the buffering process of the buffer damping is fixed, and in the buffer, the beginning of braking the speed of moving parts is the highest (only then gradually reduced), so the brake The initial impact is also the largest (later gradually weakened). That is, in the buffer, the process of braking buffer pressure is large to small changes, non-fixed value. The pc value is converted from the energy conversion point of view of the theoretical value, the average, known as the average buffer pressure. The maximum buffer pressure occurs at the highest speed at which braking is initiated. The maximum impact pressure (buffer pressure), Pcmax, is approximated by the assumption that the part of the pressure converted by the kinetic energy of the moving part decreases linearly. That is, the maximum impact pressure can be approximately equal to the sum of the average cushion pressure and the pressure converted by the kinetic energy of the moving part. In the cylinder strength check, must meet the maximum impact force is less than the cylinder material test pressure conditions.