GB647028A - An improved apparatus for testing the boost-control unit of carburetters for supercharged internal combustion engines - Google Patents

Abstract

647,028. Regulating. BRISTOL AEROPLANE CO., Ltd. July 15, 1948, No. 19066. [Class 7(vi)] An apparatus for checking whether a boost control unit 1 maintains a selected supercharge pressure comprises a chamber 9 with a compressed air pipe 10 leading to a valve 12 connected at 15 for rotation by the throttle valve 5 and delivering to an adjustable bleed outlet 17, the rotation of the valve 12 adjusting the pressure downstream thereof, the pressure being transmitted through a pipe 11 to the boost control 1, so that for any throttle setting it is equal to the supercharge pressure which would be obtained at that setting when in operation with an engine. 'The thottle valve 5 is moved by a servomotor 4 controlled by a valve 3 actuated by a pressure-responsive capsule 2 normally subject to the engine supercharge pressure, the capsule datum being adjusted by a throttle control lever 8. For a test the valve 12 is coupled to the throttle valve spindle and the lever 8 is moved to select a certain supercharge pressure. The valve 5 is thereby rotated to a certain position and the pressure in chamber 1 is adjusted by the valve 12 to be equal to the supercharge pressure corresponding to the said throttle valve position. If the boost control unit is operating correctly, the angular position of the valve 5, indicated by the pointer 16, will remain constant at the value set by the lever 8.