DK456181A - EXHAUST SLIDES FOR A STAMP COMBUSTION ENGINE - Google Patents

Abstract

The exhaust valve has a slide valve member 2 which opens away from the combustion chamber 3 of the engine cylinder and which is biased for opening by the gas pressure prevailing in the combustion chamber. The valve is kept closed by an opposed hydraulic pressure which in a holding chamber 12 acts on a holding piston 11 secured to the spindle of the valve member. When the valve is to be opened, the pressure in the holding chamber is relieved and one or more valve controlled flow passages 35, 36 are opened, through which hydraulic liquid flows from the holding chamber to a reservoir 14 defined by a piston 13 secured to the spindle 10. The two pistons, 11 and 13, are preferably of substantially equal size. When the exhaust valve is to be closed, a hydraulic pressure is applied to a substantially smaller closing piston 17 which is also secured to the spindle 10. During the closing movement hydraulic liquid flows from the reservoir back to the holding chamber and after the closing, the flow passages 35, 36 are cut off between the holding chamber and the reservoir. The increasing gas pressure in the combustion chamber 3 creates a hydraulic counter pressure in the now closed holding chamber 12 which ensures that the valve member is maintained in its closed position. The exhaust slide valve excels in a low consumption of high pressure hydraulic fluid and a low power consumption for opening and closing. <IMAGE>