GB689706A - - Google Patents

Abstract

689,706. Fuel-injection pumps. BRONZAVIA SOC. ANON. Sept. 25, 1950 [June 23, 1950], No. 23388/50. Class 102 (i). In a fuel-injection pump, a number of injection pumps comprising pistons 34 are arranged parallel around a piston valve 20 and the pistons are actuated by a cam 5. The piston valve 20 is arranged within a sleeve 15 and is driven by the camshaft 4 through a spindle 9 and sleeve 27 which has slots 30 to receive a pin 31 connected to the piston valve. The sleeve 15 has ports 16 which align with the inlet passages 33 of the injection pumps and also with a recess on the piston valve that is bounded by a helical edge 23 and a straight edge 22. The fuel is supplied to the inside of the piston valve and through port 26 and port 16 to the injection pump. When port 16 is closed by the raised portion 24 of the valve, the pump delivers through the valve 40. The ports 16 are connected by grooves 18 to diametrically opposite ports 17 the total area of which equals the area of port 16 so that the piston valve is balanced. The piston valve is moved axially to vary the pump output by fluid pressure supplied through connection 19 to act against the spring 32 and the pressure within the valve. The cam 5 also actuates several lubricating pumps comprising pistons 56 operating in cylinders having inlet ports 55. The oil trapped in pumping space 55a is forced past valve 63 and flows through the bores in the valve and the piston to port 57 and thence to ports 36 in the injection pump cylinders. Excess pressure in the bore in the piston is relieved by the valve 68.