Abstract:
A fuel injected internal combustion engine which drives a device such as a vehicle which is susceptible to sudden undesirable acceleration or deceleration is provided with injection pumps having fuel quantity control members which are coupled to an activator which in turn effects simultaneous adjustment of the control members under the control of an operator. At least one mass is coupled to the activator and prevents or compensates for undesired forces tending to effect movement of the control members as a result of accidental acceleration or deceleration of the device.

Description:
FIELD OF THE INVENTION 
     This invention relates to a fuel injected internal combusion engine and, more specifically, to such an engine which is used in devices such as a vehicle and which has a plurality of injection pumps with fuel quantity governing members controlled by an activator, the activator facilitating simultaneous control of the control members by an operator. 
     BACKGROUND OF THE INVENTION 
     It is well known that, during sudden acceleration or deceleration of a vehicle, internal forces are induced in the governor mechanism of the engine and can upset the appropriate setting thereof in an undesired manner. Depending upon the manner of installation of the engine in the vehicle, an undesired effect can, for example, occur during sudden braking of the vehicle and during disengagement of the vehicle drive, resulting in a reduction of the speed of the engine to a point where the engine stalls. In other cases, the engine may be caused to race and to exceed the setting if the governor mechanism is moved in a direction toward maximum fuel quantity injection by a sudden braking of the vehicle. 
     SUMMARY OF THE INVENTION 
     An object of this invention is to obviate these disadvantages. According to the invention, this is achieved by coupling at least one weight to the activator, the weight compensating for the undesired effect upon members of the governor mechanism produced by sudden acceleration or deceleration of the vehicle. The weight may be a pendulum member supported on the vehicle and subject to the force of gravity. Alternatively, the weight may be a slidable balancing member supported for movement parallel to the direction of movement of the activator and coupled to the activator so as to move in a direction opposite to the direction of movement of the activator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There will now be described, with reference to the drawings, two embodiments of the invention. It will be understood that the particular embodiments described are given by way of example only. 
     In the drawings: 
     FIG. 1 is a longitudinal sectional view of a piston operated injection pump and a drive cam therefor; 
     FIG. 2 is a side view of a counter-balance mechanism for controlling several injection pumps of the type shown in FIG. 1; 
     FIG. 3 is a top view, partly in section, of the counter-balance mechanism of FIG. 2; and 
     FIG. 4 is a view similar to FIG. 2 of a second embodiment of the counter-balance mechanism of FIG. 2. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows a fuel injection pump 10 which is secured from the outside, by means of a flange 10a thereon, on the casing 12 of an engine. Positioned in the interior of the engine is a drive shaft 14 which has a drive cam 14a thereon and which is coupled in a conventional manner with a not illustrated control element of the engine which effects rotation of the shaft 14. The drive cam 14a works in a conventional manner in conjuction with an end 16a of a pump piston 16. The piston 16 is axially slidable in a sleeve 18 and can be rotated around its longitudinal axis by a rotatable control bush 20. In particular, a carrier pin 16b is secured in the piston 16 and slides in longitudinal slots 20a provided in the control bush 20. A longitudinally movable operating rod 22 has teeth which mesh with circumferential teeth 20b provided on the control bush 20 and can thus rotate the elements 16 and 20 to effect a regulation of the fuel quantity injected. The piston 16 has a control edge 16 s and an end face edge 16t which operate in a conventional manner in conjunction with an inlet port 18b in the piston sleeve 18 which communicates with an operating chamber 18a for the piston so as to effect fuel quantity regulation. A threaded opening 10g is used to connect the pump 10 to a suction line (not shown), which is in turn connected to a conventional and not illustrated fuel tank and carries fuel to the suction chamber 10s of the pump 10. A further threaded opening 10r is provided to connect the pump 10 to a return flow line (not shown) which carries excess unburned fuel back to the tank. A spring-biased pressure valve 24 adjoins the piston operating chamber 18a, the valve 24 lying within a pressure line union connection 26. The pressure line itself is identified with reference numeral 27. Each of the operating rods 22 has thereon a coupling pin 22a which projects away from the pump 10 and slidably engages a respective carrier slot 28a provided in a common engine control rod 28. The control rod 28 is guided by a plurality of guide pins 30 slidably received in slots in the control rod 28 for movement parallel to the individual pump operating rods 22. The control rod 28 is operated directly or indirectly by a gas pedal controlled by the vehicle driver, so that all pump operating rods 22 are moved the same distance at the same time. 
     In order to obviate the disadvantages explained in detail in the introduction, the following balancing mechanism according to the invention is provided. The control rod 28 has a guide slot 28b in which a coupling pin 32a is received, the pin 32a being rigidly secured to one end of a double arm pivot lever 32. The pivot lever 32 is pivotally supported by an axle 32b in a bearing 34 provided on the vehicle chassis. The other arm of the pivot lever 32 carries an axle 32c on which a pendulum disc 36, which serves as a counterbalance, is supported so as to be freely rotatable. If an unintended and sudden movement of the parts 22-28 of governor mechanism of the engine were to take place, for example in the direction of the arrow A, then the pivot lever 32 will execute a rotational movement in a clockwise direction. The pendulum disc 36 suspended on its axle 32c is carried in the direction of the arrow B and produces, as a result of its weight and the force of gravity, an inertial function which inhibits or compensates for the undesired adjusting movement of the governor mechanism. Conversely, the pendulum disc 36 will move in the opposite direction to that of the arrow B during a sudden movement of the control rod 28 in a direction opposite to the arrow A and, in a similar manner, achieve compensation. 
     FIG. 4 shows a balancing mechanism which is similar in many respects to the embodiment of FIG. 2. Therefore, the same parts are referred to in each case with identical reference numerals. However, the pivot lever 132 of FIG. 4 does not carry a pendulum disc, but instead is coupled to a balancing element 136 by a pin 132c thereon which engages a guide slot 136a provided in the balancing element 136. The balancing element 136 is slidable on a guide rod 138 which extends parallel to the directions of movement of the control rod 28. During an undesired and sudden shifting movement of the control parts in the direction of the arrow A, the pivot lever 132 rotates in a clockwise direction and its pin 132c moves the balancing member 136 in direction C. 
     The sum of all masses in the governor mechanism which act upon the control rod 28 is to be equalized with respect to the mass of the balancing member 136 (with due regard to the leverage of the pivot lever 132). Since the mass of the governor mechanism, the mass of the member 36, and the fulcrum defined by bearing 34 and axle 132b all experience the same acceleration or deceleration during sudden changes in movement of the vehicle, full balancing of the forces occurs. As a result, inhibiting of or compensation for the undesired shifting movements of the governor mechanism in this example is achieved. 
     The balancing mechanism in accord with the invention is not solely restricted to use on vehicles, but can also be used on other systems which are subjected to sudden and undesired acceleration or deceleration, for example ship drive motors, where severe wave motion can create such undesired movements. 
     Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.