Patent Application
20120323464
This invention relates to a throttle control for a utility vehicle, and more specifically to a throttle control with multiple modes of operation to set the vehicle engine speed at a desired speed for operating a sprayer or other engine powered auxiliary device mounted on the utility vehicle.
Some utility vehicles may be equipped with a tank and pump for spraying liquids such as pesticides or herbicides on trees or other vegetation, or applying other materials in agricultural applications using auxiliary devices such as spreaders or top dressers. The sprayer pump or auxiliary device may be powered directly or indirectly by the utility vehicle's internal combustion engine. The spray volume or operation of an auxiliary device may change in accordance with changes in engine speed, but it may be desirable to maintain a consistent spray volume or constant vehicle and/or auxiliary pump speed. To maintain a constant engine speed while the vehicle is stopped or moving, the utility vehicle operator may try to hold the throttle pedal at a set position. Alternatively, a utility vehicle may be equipped with a mechanical linkage (or throttle governor control), that an operator may use to lock or fix the throttle pedal in a desired position to run the equipment at a constant or fixed engine speed.
However, known devices such as mechanical pedal interlock linkages have not been very satisfactory to maintain fixed engine speed for utility vehicles with sprayer pumps or other auxiliary devices. For example, mechanical pedal interlocks do not interact with the service or park brake, operator presence switch or transmission neutral position switch. As a result, there is a risk that an operator may try to set engine speed using a mechanical linkage while at least one of the interlocks is in the wrong position. Additionally, known devices such as mechanical pedal interlocks are not easy to use, install or operate.
A throttle control is needed for use with a utility vehicle having a sprayer pump or other auxiliary device powered by the utility vehicle engine that can function if the vehicle is stationary or moving. A throttle control is needed that interacts with safety interlocks on a utility vehicle such as a service or park brake, operator presence switch or transmission neutral position. A throttle control is needed for a utility vehicle with engine powered auxiliary devices such as a sprayer pump that is easy to use and relatively simple to operate.
A multiple mode throttle control for a utility vehicle includes an operator control to set engine speed with an electronically controlled throttle. The modes include a normal mode having a variable speed based on a throttle pedal position; a stationary mode with a fixed speed regardless of the throttle pedal position; and a mobile mode with a variable speed based on throttle pedal position but not higher than a set maximum speed.
The operator controls may include a mode switch that may be actuated to run the engine at the fixed speed regardless of throttle pedal position, or to run the engine at a variable speed based on the throttle pedal position but not higher than the maximum speed. The multiple mode throttle control is intended for use with utility vehicles equipped with sprayers or other auxiliary devices powered by the engine and PTO, and provides ease of use and simplicity to operate the equipment at fixed engine speeds.
In a preferred embodiment shown in
In one embodiment, multiple mode throttle control 110 may include electronic engine control unit 112 having programmed logic shown in the state diagram of
In one embodiment, the electronic engine control unit also may receive electronic inputs from interlock switches through the vehicle electrical system. For example, operator seat 122 may have interlock switch 124 indicating if the operator is seated or not; park brake or service brake 126 with park brake interlock switch 128 indicating if the park brake is engaged or disengaged; and the utility vehicle transmission or shift lever 129 may have neutral sensor 130 indicating if the transmission is in neutral.
In one embodiment, the electronic engine control unit also may receive electronic input from position sensor 132 based on the position of accelerator or throttle pedal 134. The electronic engine control unit may command engine speed using electronically controlled throttle 136 as a proportional function of throttle pedal position in the first or “Normal” mode, and until the set maximum speed is reached in the “Mobile” mode. Additionally, the electronic engine control unit may use throttle pedal position to set the fixed or maximum speeds through the electronically controlled throttle in the “Stationary” and “Mobile” modes.
In one embodiment, the multiple mode throttle control may provide three distinct operational modes. The first or Normal mode (shown as Mode 0 in
In one embodiment, as shown by reference number 202 in
In one embodiment, a second or “Stationary” mode 206 is represented as Mode 1 in
In one embodiment, the multiple mode throttle control may include stationary speed control 135 that the operator may use to set a fixed engine speed in the Stationary mode. The stationary speed control may be an adjustable secondary throttle such as a rotary potentiometer that provides an electrical signal to the electronic control unit to run the engine at the setting specified by the operator.
Alternatively, the operator may set the engine speed at a fixed speed in the Stationary mode by depressing throttle pedal 134 to a desired position, and then momentarily moving the clear and set switch 120 to the set position. The electronic engine control unit will command the engine to run at this fixed speed regardless of throttle pedal position. The operator may discontinue the fixed engine speed in the Stationary mode by momentarily moving the clear and set switch to the clear position, returning the engine speed to low idle.
In one embodiment, as shown by reference number 210 in
In one embodiment, a third or “Mobile” mode 214 is shown as Mode 2 in
In one embodiment, to set the maximum engine speed in the Mobile mode, the operator may move the throttle pedal to the desired maximum speed and then momentarily move clear and set switch 120 to the set position. This causes the electronic engine control unit to set and store the current engine speed as the setting for the maximum engine speed in the Mobile mode.
In one embodiment, in the Mobile mode, the electronic engine controller may command the engine speed to track the position of the foot throttle pedal up to the set maximum speed and no higher, as shown in the diagram of
In one embodiment, the electronic engine control unit may continue to store the set maximum engine speed in the Mobile mode even after shutdown or discontinued operation of the utility vehicle. Thus, when vehicle operation resumes in the Mobile mode, the electronic engine control unit may again prevent the engine from exceeding this set maximum engine speed. Additionally, the electronic engine control unit may command the engine to slow down to the set maximum engine speed if the operator moves the mode switch to the Mobile mode position while the vehicle is exceeding the set maximum engine speed.
In one embodiment, the operator may cancel or clear the set maximum engine speed in the Mobile mode by momentarily moving the clear and set switch to the clear position. However, to prevent the engine from speeding up unexpectedly in the Mobile mode, the electronic engine control unit may not recognize the clear command from the clear and set switch unless the foot or throttle pedal is in the low idle position.
In one embodiment, as shown by reference number 218 in
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
