New or improved automatic control means for a forced lubricating oil system of a fuel injection pump for an internal combustion engine

摘要

836,321. Lubricating. DAIMLER-BENZ A.G. May 28, 1958 [July 2, 1957], No. 17065/58. Class 12 (3). An automatic control means for a forced lubricating oil system of a fuel injection pump, e.g. a petrol injection pump 11 of an I.C. engine, comprises a lubricating oil feed pump 12 which is driven by the shaft 10 of the injection pump 11 and sucks oil through a pipe 13 from an oil sump 14 and delivers it, through a pipe 15, to the lubrication points of the injection pump. The suction pipe 13 is also connected, by a pipe 16 and a valve 17, to the forced lubricating oil circulation system of the I.C. engine to ensure that sufficient oil is always maintained in the injection pump oil system. The valve 17 comprises a hollow piston 18 slidable within a cylinder 19, chambers 21, 22 at the right- and left-hand ends respectively of which are connected by pipes 20, 16 to the delivery side of the pump 12 and the lubricating system of the I.C. engine. The port opening in the cylinder 19 for the upper portion of the pipe 16 corresponds with a slot in the piston 18 so that engine lubricant constantly, with the aid of a spring 23, urges the piston 18 toward the left against the pressure of the oil from the pump 12 in the chamber 21. When the pump 12 supplies oil at normal pressure, the piston 18 is located toward the right to close the port opening for the lower part of the pipe 16. If the pressure from the pipe 12 falls below a certain value, the engine oil pressure predominates and pushes the piston 18 to the left so that engine oil flows through the lower part of the pipe 16 to the suction side of the pump 12. Subsequent rise in pressure on the output side of the pump 12 will displace the piston 18 to the right to shut off the lower part of the pipe 16. A check valve may be incorporated in the pipe and the piston valve 17 may be replaced by a diaphragm device. In a modification, Fig. 3, two piston elements 31, 32 of a piston valve 30 working in a cylinder 29 are acted upon by the pressures from the pump 12 and the engine respectively. The elements 31, 32 control three ports in the cylinder 29 so that the suction side of the pump 12 is either connected with oil from the sump 14 of the pump 11 or from the engine. A spring 34 is situated in the left-hand compartment of the cylinder. The pump 12 and the valve structures may be combined with the housing of the injection pump.