Means for starting the engines of electric generating plant in which the prime mover is a compression ignition engine

摘要

352,591. Starting prime movers. LISTER & CO., Ltd., R. A. and ATTWOOD, F. A., 55, Garden Suburb, both in Dursley, Gloucestershire. April 26, 1930, No. 12905. [Class 38 (iv).] In an electric generating plant in which the prime mover is a compression-ignition engine, the engine is provided with electrically controlled means for reducing the normal compression space to facilitate compression ignition when starting. The engine is turned by an electric motor, the compression being (1) relieved by opening the exhaust valve, (2) increased by closing the exhaust valve and shutting off part of the compression space in order to start ignition, and (3) restored to normal by connecting the cylinder to the additional compression space. As shown in Fig. 2, the engine cylinder 12 is provided with compression spaces 32, 33 normally in communication, and the space 32 can be shut off by a valve 31 such as that described in Specification 322,097, [Class 7 (ii), Internalcombustion engines, Arrangement &c. of]. The valve 31 is connected by links 29, 30 normally held in the position shown by a spring 34, and actuated by the armature 28 of a solenoid 27. The exhaust valve 11 is actuated through a tappet 13, push rod 14, and rocker 15, and is lifted at starting by a rotatable member 16 having an arm 17 engaging a flange 25 on the tappet 13 ; the member 16 is connected by a rod 19 to a bell-crank lever 20 held by a spring 24 in engagement with a member 23 actuated by a solenoid 8, which may be controlled by a dashpot. The solenoids 27, 8 are controlled from the generating plant as indicated in Fig. 1. An electromagnetic switch 2 closes its contacts 5 when the load supplied by the battery 6 reaches a certain percentage of the capacity of the plant, and the contacts 5 control a circuit including three electromagnets 7, 8, 9. The electromagnet 7 closes the circuits of the generator 10, a series winding 26, and the solenoid 27, and the exhaust valve is held open by the member 16, so that the generator acts as a starting motor and the engine is turned over without compression, while the compression space 32 is cut off by the valve 31. After an interval determined by a dashpot 80, the solenoid 8 releases the member 17 from the tappet 13 and allows the exhaust valve to close, establishing high compression to ensure firing. After a further interval, determined by a dashpot 37, the electromagnet 9 closes contacts 38, cutting out the series winding 26 and the solenoid 27, so that normal compression is established by the opening of the valve 31, and the machine 10 is driven as a generator. The engine may be stopped by the fuel cut-off means described in Specification 352,524, which may be operated by a solenoid in the circuit of the switch 7.