Patent GB-1380472-A (GB)
Title: Internal combustion engine
IPC: F02M1/14
Filed: 1972-10-19
Abstract: 1380472 Spray carburetters; starting devices NISSAN MOTOR CO Ltd 19 Oct 1972 [20 Oct 1971] 48237/72 Heading F1B An internal combustion engine has an intake manifold 13 and a carburetter having a choke valve 15 and comprises a vacuum responsive actuator 21 for controlling the degree of opening of said choke valve, said vacuum responsive actuator including a diaphragm member 25 mechanically connected to the choke valve, a diaphragm chamber 23 communicating with the intake manifold and a spring 26 disposed in the diaphragm chamber for urging the diaphragm member 25 in a direction to close said choke valve, said diaphragm member being responsive to a vacuum prevailing in the intake manifold to move in a direction against the spring to open the choke valve, and a thermostatically controlled device 27 associated with the vacuum responsive actuator for controlling the level of vacuum acting on the diaphragm member thereby to control the degree of opening of said choke valve, said thermostatically controlled device being responsive to the temperature of the engine. The device 27 includes a housing 28 enclosing a chamber 29 connected by a passage to the inlet manifold 13 and by a duct 24 to the diaphragm chamber 23. The chamber 29 is separated by a partition 32 from a second chamber which communicates with atmosphere by a vent 34. An aperture 33 in the partition is controlled by a valve member 35 which is actuated by a thermostat 36 mounted in a cooling water passage 19. When the engine is cold, the thermostat moves the valve member 35 so that the aperture 33 is fully open, and atmospheric air enters the chamber 29. The lock of depression in the chamber 23 allows the diaphragm to be moved by the spring 26 to close the choke valve. A further linkage connects the choke valve to the throttle valve operating mechanism so that as the throttle valve approaches the fully open position the choke valve is moved to the fully open position. In a first modification the thermostat 36 is situated in the intake manifold and is subject to the temperature of the air/fuel mixture. In a second modification Fig. 4 (not shown) the vacuum control chamber (29') is located inside the air cleaner 12. Fig. 5 (not shown) shows an embodiment in which an electrical heater 53 is positioned in the air inlet 12a. The heater is energized from a battery 51, through solenoid-operated switch contacts 52a, the coil 55 of the solenoid being energized from the battery 51 through an ignition switch 54 and a thermostatic switch 56, responsive to the cooling water temperature. Fig. 6 (not shown) shows an embodiment including an electrical heater 53 in the intake manifold 13 and also a device for heating the air drawn into the air cleaner. A pipe 61 has an inlet 62 adjacent the exhaust manifold and an outlet leading to the air cleaner inlet 12a. A valve 64 controlling flow through the outlet is actuated by a diaphragm 68 subject to the depression in the intake manifold. The degree of depression communicated to the diaphragm is controlled by a thermostatic valve 74, responsive to the temperature in the air cleaner, to allow atmospheric air to enter the passage between the intake manifold and the diaphragm chamber.