GB1172623A - Improvements in Measuring Apparatus for Measuring the Delivery Quantity of a Fuel Injection Pump. - Google Patents

Abstract

1,172,623. Testing fuel injection pumps. ROBERT BOSCH G. m. b. H. Jan. 10, 1967 [Jan. 11, 1966], No.1316/67. Heading F1A. [Also in Division G1] Apparatus for measuring the delivery of a fuel injection pump 26 comprises a generator 10 producing electrical pulses whose amplitudes represent the delivery quantities of the individual pump strokes, an amplitude memory 47, an erasure generator 37 producing an erasure pulse just before the start of each pump delivery stroke and an integrating circuit 53 connecting the amplitude memory to a delivery quantity indicator 54. The delivery of the pump 26 through an injector 24 actuates the piston 11 of a sensor 17 in the solenoid 19 to provide variations in solenoid inductance. The solenoid and a capacitor form a resonant circuit having an output which is amplified and rectified by a device 43 connected to a low-ohmic output impedance transformer 44. The memory 47 comprises a capacitor 56, serving as a memory cell and connected in parallel with a transistor 58. A second transistor 60, which acts as an amplifier and impedance transformer, is rendered conductive with the first transistor 58 to erase the charge on the capacitor 56 by a pulse from the generator 37 comprising a contact spring 38 and a rotating contact 40. The contact 40, the injection pump 26, a tachogenerator 36 and a cam 32 controlling the bias of a spring 31 acting on a piston 27 controlling the drain 28 from the actuating chamber 13 of the piston 11 are driven by an electric motor 35. The Y input of the indicator 54 is connected to the tachogenerator 36 and the X input to the memory 47 to provide a curve corresponding to the delivery quantity speed characteristic of the pump. The indicator 54 may be replaced by a dial indicator, e. g. a voltmeter, which indicates directly for a given speed the pump delivery.