GB925979A

GB925979A - Liquid fuel injection pumps

Info

Publication number: GB925979A
Application number: GB29830/60A
Authority: GB
Inventors: Kenneth Albert Walters Kemp
Original assignee: CAV Ltd
Current assignee: CAV Ltd
Priority date: 1960-08-30
Filing date: 1960-08-30
Publication date: 1963-05-15
Also published as: DE1155290B; US3051154A; FR1304748A; ES270429A1

Abstract

925,979. Fuel injection pumps. C. A. V. Ltd. Aug. 17, 1961 [Aug. 30, 1960], No; 29830/60. Class 102(1). [Also in Group XXIX] A fuel injection pump of the kind comprising a rotary disc distributer, driven from the engine, having a head 15 formed with a bore 17 which houses pump pistons 18, the pistons being moved outwards by the delivery of a feed pump and inwards by lobes on a cam 20 to deliver fuel in turn to the engine cylinders, characterised in that means are provided to rotate the cam in response to engine speed to vary the timing of injection. The pump housing is formed with a cylindrical chamber 29, parallel to the tangent to the cam, which houses a movable piston member 32. A cylindrical valve member 36 is housed in a bore of the piston 32 and extends into an extension chamber 31 in the manner of a piston or plunger to seal this chamber from the chamber 29. An axial bore 45 in the valve member 36 leads to a groove 48 and includes a non-return valve 46. The piston 32 and valve member 36 are loaded by separate springs 34, 37 and the piston receives an arm 33 secured to the cam. In operation, fuel pressure from the feed pump is fed through passage 42 to chamber 31 and acts on the end of the valve member 36. When this pressure overcomes the spring 37 the valve moves to connect groove 48 with a passage 49 in the piston and fuel is fed to a chamber surrounding the valve to act on the left-hand side of piston 32. The piston 32 moves until the passage 49 is closed to the groove 48 and thus rotates the cam. If the pressure in chamber 31 drops, the valve member 36 is moved to the left by the spring 37 and the passage 49 is opened to drain causing corresponding movement of the piston 32 to the left. In a modification, the valve 36 is replaced by a piston valve without the axial passage, a branch from the passage 42 or separate fluid supply being provided which, under the control of movements of the piston valve, is admitted to or exhausted from the left-hand face of the piston, the supply passage includes the non-return valve. As shown, the piston valve extends into the chamber 31 through a sleeve member 36 which is capable of slight transverse movement to allow for misalignment. When a piston valve is used, this may be formed in two parts.