Cylinder liners are divided into two categories: dry cylinder liners and wet cylinder liners. The cylinder liner that does not come into contact with cooling water on the back is called a dry cylinder liner, while the cylinder liner that comes into contact with cooling water on the back is a wet cylinder liner. The dry cylinder liner has a thin thickness, simple structure, and convenient processing. The wet cylinder liner is directly in contact with cooling water, which is beneficial for engine cooling and lightweight.

Processing process flow

Cylinder barrel: cutting - rough turning - heat treatment (quenching and tempering) - turning (flat head chamfering) - rough pushing inner hole - rolling inner hole - turning (outer circle opening socket) - car inner hole sealing - welding cylinder bottom - car (outer circle) - internal galvanizing or chromium plating as needed

Executive standards

The production execution standard for wet cylinder liners is GB/T1150-2010. This standard is applicable to wet cast iron cylinder liners of reciprocating piston internal combustion engines with cylinder liner diameters less than or equal to 200mm.

The national standard for dry cylinder liners is still JB/NQ 56.1~56.3-87, with a wall thickness of 4mm for general use.

The symptoms of cylinder knocking during operation of diesel generator are: from medium speed to low speed, a heavy cylinder knocking sound will be made, black smoke will be emitted from the exhaust pipe of diesel generator set, and there will be sound of gunfire or fire shooting from time to time, and the engine body will overheat. The main reasons for cylinder knocking are:

1. The fuel supply time is too early

When the piston of the diesel generator set moves upward and does not reach the specified injection position, the fuel injector starts to inject fuel, so that the fuel combustion is advanced. The high-pressure gas in the cylinder impacts the piston, making a rhythmic "click, click" sound, reducing the throttle, and the knock is obvious.

The elimination method is to adjust the fuel supply advance angle, that is, increase the gasket between the fuel injection pump and the gearbox to delay the fuel supply time until it meets the specified fuel injection time. For every 0.1mm increase in the gasket, the fuel supply advance angle can be delayed by 1.3-1.7.