Motors: expansible chamber type – With motive fluid valve – To provide unequal inlet and exhaust flow rates to single...
Reexamination Certificate
2001-04-30
2003-05-13
Rivell, John (Department: 3753)
Motors: expansible chamber type
With motive fluid valve
To provide unequal inlet and exhaust flow rates to single...
C060S386000, C701S050000
Reexamination Certificate
active
06561076
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to work vehicles. More particularly, it relates to auxiliary hydraulic valves and controllers for work vehicles. Even more particularly, it relates to automated methods and structures for adjusting separate extend and retract flow rates.
BACKGROUND OF THE INVENTION
This invention provides a way to adjust electronically controlled remote hydraulic valves. It is adaptable for use on all agricultural and construction vehicles equipped with electronically controlled remote hydraulic valves.
Remote hydraulic valves provide auxiliary hydraulic flows to implements that are coupled to vehicles for performing various tasks. Typically, such a vehicle will have several such valves, commonly varying between two and eight. These valves are controlled in an operator station typically in the cab of the vehicle, most commonly by manipulating a lever or knob that provides a signal proportional to the movement of the lever or knob and indicates a desired flow rate to or from an auxiliary hydraulic valve. The hydraulic valves are typically connected to a manifold or manifolds, most commonly located at the rear of the vehicle, to which hydraulic actuators are mounted. These hydraulic actuators include such things as hydraulic motors and cylinders. By varying the position of the lever or knob, the operator can vary the flow direction and the flow rate to the manifold, and thence to the hydraulic actuators located on the implement.
Another common user input device located at the operator station is a flow rate control. The flow rate control is typically a small dial or knob that is set by the operator and indicates a maximum flow rate through the valve. Thus, by rotating the flow rate control, the operator can limit the operating range of the lever or knob from a flow rate of zero (0) to a positive maximum flow rate indicated by the flow rate control, and a negative maximum flow rate, also indicated by the flow rate control.
The flow rate controls typically provide the same maximum flow rates in both extend and retract modes of operation. In other words, when the proportional control lever is moved to one extreme limit, it will give a set flow rate of “X” through the hydraulic valve, based upon the position of the flow rate control. If the proportional control lever is moved to the opposite extreme, indicating a flow rate in the reverse direction through the valve, the operator will get the same flow rate of “X” through the valve, but in the opposite direction. This assumes, of course, that the operator has not moved the flow rate control knob.
Assume that the flow rate control is moved to a position that reduces the maximum flow rate by half. With the flow rate control in this position, moving the proportional control lever to one extreme will cause a flow rate of X/2 and moving the proportional control lever to the other extreme position will cause a flow rate of X/2 in the opposite direction through the valve.
For hydraulic flows that are changed often in the field, such as the hydraulic flows to lift cylinders on plows that rise and lower the plows at the end of each row, operators like to set up a desired flow rate using the flow rate control such that they can merely flick the proportional control lever from one extreme position or limit to the other in order to go from raise to lower, or extend to retract or the like. It is for this reason that the flow rate control is provided. By adjusting the flow rate control, the operator can reduce or increase the maximum flow (i.e. the flow corresponding to full deflection of the proportional control lever) until he can push the lever to its limit, and the implement will move at the desired speed. If he could not adjust the maximum flow rate, he would be forced to twiddle with the lever moving it back and forth in the intermediate region away from either lever limit until he gets the flow rate he desires. This diddling with the lever might also require that he look backward behind the vehicle at the implement to see how fast it is actually raising or lowering. This is dangerous. In addition, and particularly for tractors engaged in cultivating fields, the operator may already have several tasks to perform when he reaches the headlands. For example, instead of a single auxiliary hydraulic valve, he might have several auxiliary hydraulic valves that would all require substantially simultaneous operation, such as shutting off a fertilizer flow with one valve and proportional control lever, lifting a plow with another hydraulic valve and proportional control lever, and raising marker arms with yet another hydraulic valve and corresponding proportional control lever. All of these activities might be required every time the tractor enters a headland at the end of each row. All of the reverse activities of lowering the markers, lowering the plow and starting the fertilizer flow would be required once the farmer turns in the headlands and begins his new row.
The time required to individually set each of these devices to operate at the proper speed (i.e. at the proper flow rate) would be prohibitive if the operator had to carefully position each lever at some intermediate point in the range of each proportional control lever. For that reason a flow rate control is provided for each proportional control lever and hence for each auxiliary valve.
With one of these controls provided for each auxiliary hydraulic valve, the operator can individually adjust each maximum flow rate while he is safely stopped and setting up for cultivating the field. Once the flow rates are adjusted properly, he can merely flick each proportional control lever to one limit (to raise the plow or the markers, for example) and thence flick it to the other limit (to lower the plow or the markers, for example). In order to perform the three separate operations shown above, all he would have to do would be to reach down and flick three levers in a split second from one extreme lever position to the other extreme lever position. This could be done without even looking at the levers or the implement.
As explained above, the flow rate controls adjust the maximum flow rate at each limit. (As an aside, they also adjust all the intermediate flow rates corresponding to all the intermediate positions of the lever since the lever provides flow rates that are proportional to its degree of deflection from a central position toward either lever limit.) For a given position of the flow rate control, the flow rates at either of the proportional control lever limits is going to be the same, but differ in direction. By direction, I mean that flow will proceed out of a first port toward the implement and will be received back from the implement in a second port in a first direction, and will proceed out of the second port toward the implement and will be received back from the implement in the first port when the lever is moved in the other direction. The directions are indicated herein as “retract” and “extend”, or “raise” and “lower”. This does not mean that they are actually retracting or extending a cylinder, or raising or lowering an implement but are used for convenience to indicate the reversal of flow through the ports as described above.
In most cases, a single maximum flow rate in both the extend direction and the retract direction is sufficient. In some cases, however, it is not.
For example, a farmer may wish to raise a plow rapidly when he reaches the end of a row. By raising it rapidly, he can plow to the very end of the row at full depth. As the plow is lifted, the load on the tractor is reduced. The faster the plow is lifted, the faster the load is reduced.
Lowering the plow is not as easy. If the plow is lowered quite rapidly, the sudden increase in load may stall the tractor. Thus, many farmers are compelled to set a maximum flow rate that will raise the plow rapidly, and must then diddle with either the proportional control lever or the flow rate control in order to lower the plow more gently.
Since conventional systems set both the ma
Halgrimson Curtis A.
Hou Yanming
Case Corporation
Rivell John
Trausch A. N.
LandOfFree
Differential configuration of remote hydraulic valve flow... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Differential configuration of remote hydraulic valve flow..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Differential configuration of remote hydraulic valve flow... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3045733