Patent GB-1459236-A (GB)
Title: Centrifugal speed governors for fuel injection internal com bustion engines
IPC: F02D1/04
Filed: 1974-03-06
Abstract: 1459236 Centrifugal governors ROBERT BOSCH GmbH 6 March 1974 [6 March 1973]  9989/74 Heading G3B A centrifugal speed governor for fuel injection internal combustion engines comprises a sleeve 16 displaceable by centrifugal weights 12 against the force of idling and maximum speed governing springs 31, 36, and transmitting its governing movements by a double-armed lever 45, whose pivot point 52 is dependent upon the pivot point 56 of a control lever 53, to a fuel supply adjusting member 54 whose travel in the fuel increasing direction V is limited by a maximum supply stop 66, adjustable in dependence of engine speed, the stop having a cam plate 65, and being pivoted about a fixed axis 71, and connected to sleeve 16 by a lever 74, sleeve 16 comprising a transmission member 17 separated from an adjusting member 18 by a spring 21, member 18 after completing an idling stroke a striking against a stroke limiter 28a which is urged by spring 36, an accumulator 57 which is tensioned as soon as, and for as long as lever 45 attempts to move members 54, 64, beyond stop 66, stroke limiter 28a being an unyielding part of a lever 29 pivoted about point 32 and urged against a stop 41 by spring 36, spring 31 abutting an adjustable stop 33, in lever 29, the pre-tensioning of spring 21 being greater than the maximum force of spring 31, and the pre-tension force and rigidity being less than the pre-tension force and rigidity of a tuning spring 81 which acts on a yielding tuning stop 78, against which member 17 is supported at the end of the idling stroke a. In operation, in the idling governing range of stroke a, members 18 and 17 act as a rigid part; and the governing movements are transmitted to rod 54 from centrifugal weights 12 by sleeve 16, and levers 44, 45, the idling speed being controlled by pivoting levers 53 and 55 in an anti-clockwise direction, which cause anti-clockwise pivoting of lever 45 and movements in the fuel-increasing direction V of rod 54. When operating the maximum speed condition lever 53 is pivoted anti-clockwise against a full load stop so that rod 54 moves in direction V until a lug 64 on lever 63 strikes against stop 66 and accumulator 57 is pre-tensioned. When sleeve 16 has travelled through idling stroke a against the force of spring 31 face 89 of the sleeve engages face 88 of tuning stop 78 and the tension in accumulator 57 is relieved. After further increase of speed the cross pin 25 of member 18 is held securely against the face 28a of lever 29 and thus limits the stroke so that the forces on sleeve 16 are only transmitted from member 17 to the tuning stop 78. It is possible between the idling speed and the maximum speed to provide an arbitrary partial load position of the governor rod 54 independent of the prevailing speed by pivoting lever 53, since lever 44 and therefore pivot 49, are fixed. If the speed increases further after completion of stroke a member 17 moves and rotates stop 66 by lever 74 and according to the shape of cam 67, rod 54 can be moved in either the increased supply V, or the decreasing supply S directions. When member 17 moves further along the tuning stroke b spring 21 is compressed, and spring 81 is deflected by the same amount. If the maximum speed determined by spring 36 is exceeded i.e. the sleeve path is equal to a + b, lever 29 is pivoted by sleeve 16 against spring 36 anti-clockwise about point 34, lever 44 is pivoted about axis 46, through a lever 42 connected to cross pin 25, so that rod 54 is moved in the decreasing supply direction S. The tuning course may be varied by adjusting or exchanging tuning stop 78.