GB1458518A - Carburettor assemblies for precombustion chamber internal combustion engines - Google Patents

Abstract

1458518 Spray carburetters HONDA GIKEN KOGYO KK 14 Dec 1973 [30 July 1973] 58112/73 Heading F1H A carburetter assembly comprises a main passage for supplying a first mixture to a main combustion chamber of an engine, an auxiliary passage for supplying a second mixture to an auxiliary combustion chamber of the engine, each passage having a throttle valve mounted on a rotatable shaft, means 12, 13, 14 for transmitting turning movements between the shafts, a choke valve 16 mounted in the primary passage upstream of the primary throttle valve 5, means for actuating the choke valve 16 and means for moving the primary throttle valve in response to operation of the choke valve actuating means, whereby actuation of the choke valve brings about movement of both the throttle valves 5 and 9. Choke valve 16 is unbalance mounted on shaft 17 which projects through stationary sleeve 19 and carries an angled lever 43. Choke operating knob 32, through cable 23 rotates actuator 20 in a clockwise direction, as seen in Fig. 1, against torsion spring 25, when the cable is pulled. Actuator 20 runs on sleeve 19 and through torsion spring 44 turns crank member 37 which has an arm 41 which engages lever 43 and turns choke valve 16 in a closing direction. Crank member 37 is also connected by rod 40 to vacuum motor 64, which turns the choke valve in the opening direction when the engine is running under its own power and the intake manifold vacuum acting in chamber 67 overcomes spring 72. The amount by which the choke valve is turned in the opening direction is determined by limiter member 52 which is rotatably mounted on pin 53 and includes a follower member 51 which also runs on cam surface 49. As limiter member 52 is rotated anti-clockwise by the cam surface, a stop member 54 moves to a position which is dependent on the extent to which the actuator 20 has been turned by using the operators control knob 32. Stop member 54 is engaged by projection 55 on crank member 37 when this is rotated by movement of the rod 40. Actuator 20 also includes a cam surface 49 which engages a cam follower 57 on lever 58 and rotates the lever about pivot 59 so that end 60 of the lever engages tab 61 on lever 7 and rotates main throttle valve shaft 6. Link 14 transmits the movement to lever 13 and thus rotates auxiliary throttle valve 9. In a modification, Fig. 6, (not shown), the choke valve is moved to the closed position by a conventional bimetal coiled spring 92, when the accelerator pedal is fully depressed prior to starting the engine. The linked throttle valves open to an extent determined by a stepped cam 107. The limiter member 52 is replaced by a second stepped cam 102 which is rotated to a position dependent on the ambient temperature by a bi-metal spring.