Cold starting devices for diesel engines with compensated supercharging

Claim 1

A device for cold starting a diesel engine having a compensated supercharging device with a turbosupercharger, a heat exchanger in the duct connecting said turbosupercharger to the engine, a volumetric supercharger inserted between said turbosupercharger and the induction manifold of said engine and having a driving shaft connected to the engine crankshaft via a variable-speed transmission comprising a belt and a pair of pulleys having axially movable flanges, clutch means interposed between said shaft and said transMission for disconnecting said volumetric supercharger from said transmission, and an electric starter motor of the engine, the device for cold starting comprising a separate electromotor coupled to said shaft directly for driving it only during the cold starting of said engine with a speed higher than the variable speed transmission pulley driving said shaft under normal operating conditions, said device further comprising a pipe having one end connected permanently to said induction manifold of the engine and having its other end open and connected to the free atmosphere, a solenoid-operated valve mounted in said pipe, and means for energizing said valve when said electromotor is starting by very cold weather, to open it and to vent said manifold to the free atmosphere in conjunction with timing means for a delayed energization of said starter motor, whereby said valve is deenergized for closing said vent pipe before de-energizing said starter motor.

Claim 2

A device for cold starting a diesel engine having a compensated supercharging device with a turbosupercharger, a heat exchanger in the duct connecting said turbosupercharger to the engine, a volumetric supercharger inserted between said turbosupercharger and the induction manifold of said engine and having a driving shaft connected to the engine crankshaft via a variable-speed transmission comprising a belt and a pair of pulleys having axially movable flanges, clutch means interposed between said shaft and said transMission for disconnecting said volumetric supercharger from said transmission, and an electric starter motor of the engine, the device for cold starting comprising a separate electromotor coupled to said shaft directly for driving it only during the cold starting of said engine with a speed higher than the variable speed transmission pulley driving said shaft under normal operating conditions, said device further comprising a pipe having one end connected permanently to said induction manifold of the engine and having its other end open and connected to the free atmosphere, a solenoid-operated valve mounted in said pipe, and means for energizing said valve when said electromotor is starting by very cold weather, to open it and to vent said manifold to the free atmosphere in conjunction with timing means for a delayed energization of said starter motor, whereby said valve is deenergized for closing said vent pipe before de-energizing said starter motor.