Abstract: Device for stopping a fuel injection internal combustion engine by turning a key in a stopping box into the STOP position. In hitherto known devices, when turning the key into the said position, current feeding the coil of the electromagnetic valve during the operation of the engine is cut off, and this valve is closed then by means of a prestressed spring. This makes impossible a free outflow of fuel leaving the reducing valve of a low pressure circuit of the injection device, and directs all fuel delivered by a delivery pump into a hydraulic member, the piston of which, by means of fuel pressure, shifts the control bar into the position STOP; in this way the engine is stopped. Such known arrangement requires too much power, since the coil of the electromagnetic valve is energized by current all during the operation of the engine. In accordance with the invention the coil of the electromagnetic valve is deenergized current during the operation of the engine.

Abstract: A piston-type injection pump for supplying a nozzle-type injector in a diesel engine is provided with integral facilities for effecting the controlled expansion of the discharge conduit between the pump and the injector and with additional facilities for limiting the rate of pressure drop in the discharge conduit during the volume expansion step. A cylindrical member disposed in a chamber that is in fluid communication with the working chamber defined by the piston-cylinder portion of the pump slidably receives an elongated cylindrical valve that is normally biased into a flow-blocking condition. Such cylindrical member has associated therewith suitable relief elements, such as a separate relief valve carried axially therein, to permit expansion of the space above the cylindrical member and to thereby accommodate an expansion of fluid downstream of the pump at the conclusion of the pressure stroke of the piston.

Abstract: A piston-type injection pump for supplying fuel through a discharge conduit to an injector of an internal combustion engine. The injection pump has a relief piston movable between an upstream and a downstream position in a sleeve. This relief piston limits the rate of pressure drop in the discharge conduit. The sleeve has an annular groove and the relief piston is formed by at least one annular recess. A channel extends transversely through the relief piston at said annular groove. An axial blind channel terminates at said transverse channel. These two channels form part of the flow path for the fuel. The upper edge of either the annular groove or annular recess and the lower edge of the other define therebetween a maximum flow-through area for the fuel when the relief piston is in the upstream position. This maximum flow-through area is substantially equal to the cross-sectional flow-through area of the discharge conduit.

Abstract: An improved, pressure-sealed mounting arrangement for a cylinder head of a diesel-type fuel injection assembly is described. The working cylinder of the pump assembly has an upward axial projection which tightly receives the lower end of a hollow cylinder head along an extended interface to define a pressure-sealed zone, such zone being disposed above the position of maximum upward travel of the cylinder piston. The head exhibits a lateral projection intermediate its ends for contacting the upper surface of the axial extension of the cylinder. Both the cylinder head and the cylinder extension are tightly secured to the upper portion of the pump body that surrounds the cylinder with the use of a threaded arrangement that tightly secures the lateral extension on the cylinder head to the axial extension on the cylinder and which also secures one of such members to the upper portion of the pump body.

Abstract: An improved assembly of the working cylinder and cylinder head in a casing of a diesel-type fuel injection pump is described. A lower portion of the cylinder head, which houses a discharge valve, is inserted into the upper portion of the cylinder. A piston reciprocable within the lower portion of the cylinder carries a flange on its lower end for supporting a spring, whose upper end bears, via an intermediate member, on the cylinder to urge the cylinder-cylinder head sub-assembly upward in the casing until a flange disposed intermediate the ends of the cylinder head abuts an upper, centrally apertured end plate of the casing. In the assembled position, an upper threaded end of the cylinder head extends outwardly from the aperture in the end plate to receive a conventional pressure fitting. Suitable facilities are provided for inhibiting rotation of the cylinder-cylinder head sub-assembly in the casing.