Hydraulic cylinders are actuators that are used to enable linear movements in machines. In automotive hydraulic cylinders, the working substance is liquid (like oil), unlike pneumatic cylinder where air is the working substance. One kind of the hydraulic cylinder is the automotive hydraulic cylinder. The automotive hydraulic cylinders are used in automotive devices like municipality garbage vans, agricultural instruments, dump trucks, tow trucks, tractors and cranes. The various applications of automotive hydraulic cylinders are sky lifts, car carriers and damper placers. The bore of automotive hydraulic cylinders is in the range of 40 mm to 150 mm. The stroke of automotive hydraulic cylinders is generally large with stroke length of 3000 mm to 4500 mm. One kind of automotive cylinder that is used in municipality garbage trucks is the tipping cylinder. These kinds of cylinders are used for the purpose of lifting heavy weight of the tailgate of the truck and tilt it, in order to dispose the contents onto the ground. Tipping cylinders are, in general, like the telescopic hydraulic cylinders. The rod end of these cylinders has a series of rods that consecutively decrease in size. These rods collapse one into another when the cylinder is contracted.
The Tipping cylinders can be used either as the under body tipping cylinders or the front end tipping cylinders. The under body tipping cylinders are the cylinders that contract to a very small length when the tailgate is not tipped. The rod end of this type of tipping cylinder is attached to the bottom of the tailgate. The front end tipping cylinders are also telescopic in nature. But these are longer than the under body tipping cylinders when fully contracted. The rod end of the front end tipping cylinders is attached to the front end of the tailgate of the truck. Comparatively, the front end tipping cylinders are more economical than the under body tipping cylinders. This is because the front end tipping cylinders provide a larger torque than the under body tipping cylinders for the same applied force because of the larger distance between the pivot and the point of action of force.
There are two types of tipping cylinders or automotive cylinders in terms of the mechanism of working of the cylinders. They are: two stage hydraulic cylinders, multi two stage hydraulic cylinders. The two stage hydraulic cylinders, as the name suggests, has only two stages, with only two consecutive telescopic rods, at the rod end of the cylinders. The multi stage telescopic cylinders, there are more than two stages. There are two kinds of telescopic cylinder designs: single action cylinders where the stoke acts only in one direction, and double action cylinders where the hydraulic power acts in both extension and contraction of the cylinders.