FESTO cylinder piston knocking cylinder judgment assembly description

Judging method of piston knocking cylinder of FESTO cylinder and processing link assembly

   First, the FESTO cylinder presses the connecting rod copper sleeve. It is best to use a press when installing the connecting rod copper sleeve, or by means of a vise. Do not use a hammer to strike it; the oil hole or oil groove on the copper sleeve should be aligned with the oil hole on the connecting rod to ensure lubrication.

  Second, the assembly of pistons and connecting rods. When assembling pistons and connecting rods, pay attention to their relative position and orientation.
   
  Third, cleverly installed piston pin. The piston pin and the pin hole are in an interference fit. When installing, the piston should be evenly heated to 90 °C ~ 100 °C in water or oil. After taking out, put the tie rod in the proper position between the piston pin hole, and then install the piston pin coated with organic oil in the given direction. Into the piston pin hole and the connecting rod copper sleeve

Fourth, the installation of the piston ring. When installing the piston ring, pay attention to the position and sequence of each ring.
   
5. Install the connecting rod set.
    Handling the piston knocking cylinder can be handled in the following ways:
    (1) After the engine is started, there is a knocking sound when the engine is running at a low temperature. After the temperature is normal, the sound disappears and can be temporarily processed without further processing.
    (2) When the engine temperature is normal, there is obvious knocking sound. Try to avoid high-speed operation and disassemble and repair as soon as possible.
    (3) After removing the cylinder head and extracting the piston, it is found that the cylinder is seriously out of roundness or strain, or the clearance between the piston and the cylinder is too large, and should be replaced to replace the cylinder liner, piston and piston ring.
    (4) If the link is found to be deformed, it should be replaced as much as possible.

    (1) Oil is cut off by cylinder. Take the method of cylinder-by-cylinder oil cut to determine the position of the knocking cylinder. If the oil is cut to a certain cylinder, the sound will obviously decrease or disappear, and when the oil supply is restored, a clear "click" sound will be heard, indicating that the cylinder The piston knocks on the cylinder.
    (2) In order to further confirm that the cylinder piston is knocked, the injector of the cylinder can be removed, a small amount of CD-grade supercharged oil is added to the cylinder (to seal), the injector is installed, and the engine is started. The knocking sound disappears or weakens. After the operation, the knocking sound reappears, and the piston of the cylinder is undoubtedly knocked.
   

    The main reasons why FESTO produces piston knocking cylinders are as follows:
    (1) The clearance between the piston and the cylinder wall is too large. The standard clearance of the piston skirt and cylinder of the WD615 series engine is 0.143-0.182, and the maximum wear limit is 0.35-0.40.
    (2) After the engine runs for a period of time, the cylinder piston wears out, and the lubrication is not good. The matching clearance between the piston and the cylinder increases due to wear, and a serious step appears in the first gas ring slightly, causing the piston to knock. The cylinder hits an abnormal sound.
    (3) After the piston skirt and the cylinder are running for a period of time, the wear is severe, causing serious rounding and knocking on the cylinder.