Electrical generators are used in a wide variety of applications. Typically, an individual electrical generator operates in a stand-by mode wherein the electrical power provided by a utility is monitored such that if the commercial electrical power from the utility fails, the engine of the electrical generator is automatically started causing the alternator to generate electrical power. When the electrical power generated by the alternator reaches a predetermined voltage and frequency desired by the customer, a transfer switch transfers the load imposed by the customer from the commercial power lines to the electrical generator.
As is known, engine-driven, electrical generators are often exercised to insure proper operation when their use is required. In order to exercise the engine-driven, electrical generator, the engine is either automatically or manually started and runs for a predetermined time period at its full operating speed. It can be appreciated that any operation of the engine-driven, electrical generator can produce unwanted noise. This, in turn, may discourage a user from exercising their electrical generator in a timely manner. Further, due to various local ordinances, it has become highly desirable to reduce the noise associated with exercising a stand-by electrical generator.
One option for reducing the noise associated with exercising a stand-by electrical generator is to operate the electrical generator at a lower engine speed. It can be appreciated that there are certain inherent problems associated with operating an engine at speeds below the normal operating speed. Typically, the speed of the engine is slowed by reducing the air-fuel mixture supplied to the cylinders of the engine. However, it is difficult to balance the air-fuel mixture provided to each cylinder of the engine. As a result, the performance of the engine suffers. Further, there may be additional emissions associated with operation of the engine at a low speed.
Therefore, it is a primary object and feature of the present invention to provide a fuel mixer box incorporating a control device for regulating the air-fuel mixture provided to a stand-by electrical generator during the exercise thereof.
It is a further object and feature of the present invention to provide a fuel mixer box incorporating a control device for regulating the air-fuel mixture provided to a stand-by electrical generator during the exercise thereof such that the stand-by electrical generator generates less noise than during prior exercise methods.
It is a still further object and feature of the present invention to provide a fuel mixer box incorporating a control device for regulating the air-fuel mixture provided to a stand-by electrical generator during the exercise thereof that is simple to operate and inexpensive to manufacture.
In accordance with the present invention, a device is provided for balancing a fuel mixture provided to each cylinder of an engine during the exercise of the engine. The device includes first and second input conduits. Each input conduit has an input connectable to a fuel source for receiving fuel therefrom and an output. First and second output conduits have inputs communicating with the outputs of corresponding first and second input conduits and outputs connectable to corresponding cylinders of the engine. A housing has an interior and an opening therein for allowing air to enter the housing. The housing includes a first fuel mixture chamber interconnecting the output of the first input conduit and the input of the first output conduit. The first fuel mixture chamber has an input communicating with the interior of the housing. The housing also includes a second fuel mixture chamber interconnecting the output of the second input conduit and the input of the second output conduit. The second fuel mixture chamber has an input communicating with the interior of the housing. A balancing device is positioned in the housing for selectively controlling the flow of air from the interior of the housing into the first fuel mixture chamber.
The balancing device may also selectively control the fuel flowing in at least one of the first and second input conduits. The balancing device includes a valve plate pivotably mounted within the housing. The valve plate is movable between a first open position and a second exercise position wherein the valve plate overlaps at least a portion of the input of the first fuel mixture chamber. The balancing device may also include a rotatable shaft operatively connected to the valve plate and extending into the first input conduit. The shaft is movable between a first open position for allowing a first volume of fuel to flow therepast and a second exercise position for allowing a second volume of fuel to therepast. It is contemplated for the first volume to be greater than the second volume. The shaft includes an aperture therethrough. The fuel flows around the shaft with shaft in the open position and through the aperture in the shaft with the shaft in the exercise position.
The fuel mixer box may also include a solenoid having an extendable plunger operatively connected to the valve plate for moving the valve plate. The solenoid is movable between a first retracted position to maintain the valve plate in the open position and an extended position for maintaining the valve plate in the exercise position. An adjustment device is operatively connected to the valve plate for setting the exercise position of valve device. A stop plate projects into the interior of the housing. The adjustment device includes a support projecting from the valve plate. The support has a threaded aperture therethrough. A screw extends through the threaded aperture. The screw includes a shaft having a terminal end that engages the stop plate so as to define the exercise position of the valve plate.
In accordance with a further aspect of the present invention, a fuel mixer box is provided for balancing a fuel mixture provided to each cylinder of an engine during the exercise of the engine. The fuel mixer box includes a first input conduit having an input connectable to a fuel source for receiving fuel therefrom and an output. A first output conduit has an input communicating with the output of the first input conduit and an output connectable to a first cylinder of the engine. A second input conduit has an input connectable to the fuel source for receiving fuel therefrom and an output. A second output conduit has an input communicating with the output of the second input conduit and an output connectable to a second cylinder of the engine. A housing defines an inner chamber and an opening therein for receiving air. The housing includes first and second fuel mixture chambers. The first fuel mixture chamber interconnects the output of the first input conduit and the input of the first output conduit. The first fuel mixture chamber has an input communicating with the inner chamber of the housing. The second fuel mixture chamber interconnects the output of the second input conduit and the input of the second output conduit. The second fuel mixture chamber has an input communicating with the inner chamber of the housing. A valve plate is pivotably mounted within the housing. The valve plate is movable between a first open position and a second exercise position wherein the valve plate overlaps at least a portion of the input of the first fuel mixture chamber. A fuel control element extends into the first input conduit. The fuel control element is movable between a first open position for allowing a first volume of fuel to flow therepast and a second exercise position for allowing a second volume of fuel to therepast.
The fuel control element is operatively connected to the valve plate for pivotable movement therewith. The fuel control element includes a rotatable shaft operatively connected to the valve plate and having an aperture therethrough. The fuel flows around the shaft with the fuel control element in the open position and the fuel flows through the aperture in the shaft with the fuel control element in the exercise position.
The fuel mixer box may also include a solenoid having an extendable plunger operatively connected to the valve plate for pivoting the valve plate. The solenoid is movable between a first retracted position to maintain the valve plate in the open position and an extended position for maintaining the valve plate in the exercise position. An adjustment device is operatively connected to the valve plate for defining the exercise position of the valve device. A stop plate projects into the interior of the housing. The adjustment device includes a support projecting from the valve plate and a screw. The support has a threaded aperture therethrough. The screw extends through the threaded aperture and includes a shaft having a terminal end. The terminal end of the shaft engages the stop plate so as to define the exercise position of the valve plate.
In accordance with a still further aspect of the present invention, a method is provided for exercising an engine having a plurality of cylinders at a predetermined speed less than the normal operating speed of the engine. Each cylinder receives an air-fuel mixture having an air component and a fuel component. The method includes the step of reducing the air component and the fuel component in the air-fuel mixture. Thereafter, the volume of the air-fuel mixture provided to each cylinder of the engine is balanced.
The step of reducing the air component includes steps of providing an input having a cross-sectional area for receiving the air component of the air-fuel mixture and reducing the cross-sectional area of the input. The step of reducing the cross-sectional area of the input includes the step of providing a valve plate. The valve plate is in a non-interfering relationship with the input of the engine. The valve plate is pivoted to an exercise position wherein the valve plate overlaps at least a portion of the input.
It is contemplated for the method to include the additional step of adjusting the exercise position of the valve plate and for the step of reducing the fuel component to include the steps of providing an input having a cross-sectional area for receiving the fuel component of the air-fuel mixture and reducing the cross-sectional area of the input. The input for the fuel is defined by a fuel conduit having a passageway with a cross-sectional area. The step of reducing the cross-sectional area of the input includes the steps of providing a fuel control element in the fuel conduit and rotating the fuel control element to an exercising position to reduce the cross-sectional area of the passageway.