MXPA00007840A - Bypass system for electronically controlled implement lift - Google Patents

Abstract

An implement lift with a plurality of individual electrohydraulically controlled lift cylinders spaced on a tool frame includes a bypass system for facilitating continued implement operation in the event of a failure of the electronics or wiring. The system includes an electrically controlled valve at each cylinder normally operated by an electronic controller but manually lockable in an open position if there is a circuit failure so the operator can control the implement from the tractor selective control valve (SCV). Hydraulic hoses with quick disconnects compatible with both the tractor SCV connections and the main electrohydraulic valve on the tractor are connected to the tractor valve for normal automatic operation but can be easily rerouted to the SCV connections for control by the SCV when the cylinder valves are manually locked in the open position.

Description

DEVIATION SYSTEM FOR ELECTRONICALLY CONTROLLED IMPLEMENT ELEVATOR BACKGROUND OF THE INVENTION 1) Field of the Invention The present invention relates generally to agricultural implements and more specifically to control the hydraulic depth control cylinders for such implements. 2) Related Art Multi-frame implements available such as field cultivators and chisel plows use a hydraulic cylinder system to provide depth control during field work operations and proper ground clearance during transportation. The depth control systems as shown in U.S. Patent No. 3,663 / 032 use reflow cylinders connected in series to raise and lower the frames in unison. Other systems rely on mechanical depth stops to control the operating height, but do not allow the operator to change that height from the cab or easily vary the depth for different conditions of transport, with lathes of land and soil conditions. In addition, both the cylinder in series and the mechanical depth stop systems require a mechanical adjustment outside the cab to adjust the height of the wing frames in relation to the central or main frame. The level control suitable for leveling the longitudinal frame or the inclination for leveling from side to side has presented problems.

In the co-pending and commonly assigned United States of America patent application no. of series 08 / 972,925 filed on November 18, 1997 and entitled "Electrohydraulic Control of Implement Lift Cylinders", we describe an improved lifting system that includes a plurality of electrohydraulically controlled individual cylinders spaced on a tool frame and connected to the structure of frame suspension such as lift wheel assemblies. An implement control unit (ICU) in the tow vehicle cab is connected to feedback potentiometers or similar transducers which provide signals that correspond to the stroke length of the cylinder or to the suspension position. The feedback signals are compared in the implement control unit to control the signal obtained by the rotation of a lever or knob in an operator control unit in the cab. Depending on the position of the cylinder in relation to the selected position of the operator. the implement control unit provides an output signal to the electro-hydraulic valve to achieve a proportional amount of flow for the desired cylinder position. The implement control unit also compares the feedback signals from the transducers and adjusts the output voltage to each of the valves so that the frame can be raised and lowered evenly. In conditions where independent adjustment of the different frame parts is desired, the operator control unit can be adjusted to provide the required off-center signal for each section. The lifting system provides uniform depth control and a level of elevation even with dissimilar cylinders with different capacities and different stroke lengths. The depth control and the elevation level can be achieved, in relation to both the longitudinal and transverse directions.

A problem with an implement that uses electronic controls is the lack of capacity to continue operations or to raise the implement for transport without a time consuming repair or extensive re-tubing of the hydraulic hoses if there is a failure in the electronics, in the Wiring frame or electro-hydraulic valves. It is desirable to have a simple structure and an efficient and direct method for the continued operation of the implement in the event of a failure.

BRIEF SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a depth control or implement lift system. It is a further object to provide such an improved system which overcomes most or all of the aforementioned problems.

It is a further object of the present invention to provide a depth control or implement lift system which includes a structure that facilitates continued attachment operation in the event of a failure of an electronic component, wiring or valve electrohydraulics It is yet another object to provide such a system which is relatively simple in construction and easy to convert to a manual deviation mode of operation in the case of component failure. It is still another object to provide such a system where the conversion to the deviation mode allows the continuous field operation of the implement; it is a further object to provide such a system when the depth control and choice functions are provided in the deviation mode.

It is still another object of the invention to provide an improved implement lift system having automatic electronic control of the lift cylinders, in where the system can be easily converted to a manual control mode if electronic control fails. It is another object to provide such a system which uses the electro-hydraulic control valves, the control valves have a deviation for the operation of the cylinders from the tractor selective control valve (SCV).

A implement depth and lift control system with a plurality of individual electrohydraulically controlled lift cylinders spaced over a tool frame includes a deflection system to facilitate continued attachment operation in the event of a failure of the electronics or the wiring. The system includes electrically controlled cylinder valves normally operated by an electronic controller and manually fixed in an open position if there is a circuit failure so that the operator can control the implement from the tractor selective control valve. In systems that have an added electrohydraulic valve controlled by the implement control unit, hydraulic hoses with quick disconnects compatible with both the tractor selective control valve and the aggregate valve connections can be easily redirected to the valve connections. Selective control of the tractor for control by the selective control valve when the cylinder valves are manually fixed in the open position. Low bumpers such as Cylinder donuts or other mechanical structures are provided in the implement for conventional depth control when automatic control is bypassed. The operator simply activates a manual control on each valve which sets the valve in the open position. A mechanical stop arrangement, such as the donuts placed on the cylinder rod, determines the depth of operation. The failure of the electronics, the wiring or the control valve no longer dictates that the farmer immediately stop field operations for repairs.

These and other objects, features and advantages of the present invention will be apparent to one skilled in the art of reading the following detailed description in relation to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic representation of an electronically controlled depth and elevation control system on an agricultural implement.

Figure 2 is a schematic diagram of a valve with a manually operated deviation used with the system of Figure 1.

Figure 3 is a side view of an electro-hydraulic valve with a manually operated bypass fastener.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to Figure 1, there is shown generally at point 8 an implement with ground working tools (not shown) supported from a transversely extending frame 12. Frame 12 includes a central section or frame 16 and the wing sections 18 and 20 pivotally connected to the central section 16 for pivoting in relation to the central section around the longitudinal extending axes. The first and second central frame elevator assemblies 22 and 24 are connected to the section 16. The wing sections 18 and 20 include the wing elevator assemblies 30 and 32. The latch structure (not shown) is pivotally supported from the front part of the frame 16 for connection to a tractor for pulling the implement 10 forward on a field.

The electrohydraulically controlled individual cylinders 42 and 44 are spaced on the frame 12 and connected to the lifting wheel assemblies 22 and 24. The cylinders 50 and 52 located on the wing sections 18 and 20 are connected to the wing lifting assemblies. 30 and 32.

As shown in Figure 1, the cylinders are controlled by the individual electrohydraulic control valves 62, 64, 70 and 72. Valves 62 and 72 are shown as proportional valves of two positions and four-way valves connected between the base ends of the cylinders and a source of hydraulic fluid under pressure on the tractor 78 through the selective control valve (SCV) 79. The cylinders 45-52 are connected through the implement valve structure 80 through the pipes hydraulic 81 and 82. The implement valve structure 80 is shown as a separate valve added in Figure 1 but it should be understood that the structure may also be integral with the tractor, as exemplified by the John Deere 8000 series tractors. and 9000 commercially available.

An implement control unit (ICU) 90 is connected to feedback potentiometers 92 or similar transducers which provide signals through lines 94 that correspond to the cylinder stroke length or suspension position. An operator control unit (OCU) 100 is connected through the control lines 102a-102g to the implement control unit 90. A remote vane potentiometer 106 provides an up / down signal path pipe 108. On tractors such as the John Deere 8000 and 9000 series tractors with an integral 80 implement valve structure, the necessary signals are transmitted through the tractor bus before being interpreted by an exhibitor and sent to the implement control unit 90 without the need for the potentiometer 106. The operator control unit 100 has the inputs set by the standard operator and provides the following outputs (which are indicated as lines 102a to 102g in figure 1) the indicated lines depend on the adjusted inputs: 102 (a) Intermediate depth control voltage signal; 102 (b) Depth voltage signal; 102 (c) Depth of left wing depth; 102 (d) Depth of right wing depth, - 102 (e) Main frame level; 102 (f) Disable off-center; 102 (g) Power source; The implement control unit 90 compares the voltage on line 94 for each elevator assembly with a desired signal voltage for the elevator assembly. The implement control unit 90 also compares the signal voltage for each survey set with the signal voltages of the other survey sets to raise and lower the machine evenly and to provide any desired tilt and leveling functions.

The operator control unit 100 includes a level reference control and a zero reference control. A depth control and an intermediate depth control set the working depth in the work positions in the field. A right wing off-center control and a left wing control facilitate adjustment of the wings 18 and 20 relative to the center frame 16. A main frame level control adjusts the height of the left side of the center frame relative to the right side of the frame 16. An enabling / disabling switch facilitates repositioning of the positions. The operator control unit 100 includes a digital reading of the selected working depth. The depth controls may include several resistors with rotary knobs that have detents for various operating conditions and for a convenient return to a pre-selected level placed after the off-center control feature has been used. Alternatively, buttons or membrane switches to provide an increase signal for the off-center control feature can be used.

The intermediate control position can be set to any desired level between the working depth and the completely elevated position. The intermediate depth control position, for example, can be set to maintain the frame 12 in a position where the tools 10 barely engage the ground when the tire bands are removed without a deep threshing or when they are overturned when the tools 10 do not have to be lifted completely off the ground. The intermediate control is also useful when the implement is moving on irregularities in the terrain such as waterways and so on.

The control output lines 114 of the implement control unit 90 selectively activate the electrohydraulic valves 62-72 to operate the cylinders 42-50 and provide the desired depth and lift control functions. A control line output 118 provides automatic control of the implement control unit 100 for the valve structure 80 to pressurize the hydraulic line 82 so that one or more of the valves 62-72 extends to the corresponding cylinder or cylinders. when the elevation is required. Line 82 is returned to the sump when the descent of the implement is required. Alternatively, the four-way and four-way valves can be used so that the steering control is provided directly by the valves 62-72 without requiring a pressure reversal in the pipes 81 and 82. The two-way valves and Two positions can also be used with the system. Further, On-off type valves can be replaced by proportional valves.

The feedback signals from the pipes 94 are compared in the implement control unit 90 for a control signal obtained by the button operation or the rotation of a lever or knob on the operator control unit 100. Depending on the position of the cylinder in relation to the position selected by the operator, the implement control unit 90 provides an output signal to the electrohydraulic valve to achieve a proportional amount of flow for the desired cylinder position. The implement control unit 90 also compares the feedback signals from the transducers and adjusts the output voltage for each of the valves so that the frame 12 can be raised and lowered evenly. In the conditions where the independent adjustment of the different frame parts is desired, the operator control unit 100 can be adjusted to provide the required off-centering signal for each section. The lifting system provides uniform depth control and a level survey, even with dissimilar cylinders with different capacities and stroke lengths. The additional wheel assemblies can be decentered in the longitudinal direction from the assemblies 22 and 24 and controlled by the implement control unit and the operator control unit to provide leveling in front of the back part.

The lifting assemblies move the frame 12 between a raised transport position where the tools 10 are offset by a substantial distance above the ground and a working position in the lowered field where the tools 10 penetrate the ground. In the work position in the field, the cylinders of the wheel assembly can be extended or retracted to adjust the depth of penetration of the tools 10 from a sparse scraping position to a lower deep threshing position. The cylinders of the wheel assembly can be adjusted in any frame position to vary the positions of the wing in relation to the position of the center section 16 and to level the frame or to vary the height of the section from side to side and from the in front of the back.

The implement control unit 90 reads the analog inputs from the transducers 92 to control the individual lifting cylinders. Also, a control valve signal is provided through line 118 from the implement control unit to add the implement control valve 80 (or directly to the selective control valve unit integrated in the newer tractors) . The source 78 includes a standard manually operated selective control valve 200. On the newer tractors. the source 78 is controlled from the implement control unit and from the conventional positioning controls 200 and the standard selective control valve lever located in the tractor cab.

The electrohydraulic valves 62-72 are generally identical and only the valve 62 will be described in detail. Referring to Figures 2 and 3, the valve 62 includes a body with an inlet port 161 and an outlet port 162 which are connected to the base end of the corresponding cylinder. A bleed screw 164 is located on the outlet side of the valve. A solenoid 166 with a connector 168 controls the four-way, two-way valve to connect the base end of the cylinder to the line 82 and to adjust the flow through the valve. A shut-off valve 170 that includes a knob 172 is located on the top of the solenoid. To close the valve 62 in the fully open position, the operator presses the closure and then turns the knob 172 by a quarter turn in the left to right direction. Alternatively, any type of mechanical closure arrangement, such as a lever or a threaded screw can be used to keep the valve in the fully open position. The valve will remain in the fully open position maintained by latch 170 regardless of the signal on line 94. To return to automatic operation, the operator simply turns the knob a quarter of a second. turn in the right to left direction and release the knob 172 so that the valve spool can be moved from the closed position to a position dependent on the signal in the pipe 94. Therefore, if an electrical fault occurs, the operator can close all valves 62-72 in the open position and control the lifting and lowering functions directly with the selective control valve of the tractor 79. The donuts 180 for the cylinder rods or other mechanical stops on or associated with the sets of lift provide depth control. If the implement control 80 is used, the control is diverted by disconnecting the lines 81 and 82 from the control at the locations of the connector 182 and reconnecting them to the connectors at the locations 184 at the output of the selective control valve from the source 78. Identical connectors are provided at both places 182 and 184 to facilitate changes to and from the operation deviation mode.

In operation, after the operator has attached the implement 8 to the tractor and has connected the hydraulic lines 81 and 82 between the implement and the tractor, the positioning of the selective control valve is activated and the implement moves to a surface of the tractor. level . The selective control valve lever is moved to raise the wheels from the ground and then the lever is placed in the float position so that the wheel assemblies make contact with the level surface. The operator then pushes the level reference control to establish the voltage reference levels from the transducers 92 that correspond to the level reference position. The implement is then raised and dragged to the field where the frame 12 is lowered until the tools make contact with the surface. The zero reference control is pressed to establish a zero level reference for the particular field conditions. The operator then lowers the machine to the desired depth of work and presses a button to establish a working depth setting. Alternatively, a knob can be used which the operator turns until the desired operating depth is indicated in the digital reading. Initially, the left and right wing offsets and the central level control are set for the level operation. The lever of the selective control valve is activated and the implement wheel assemblies lower the frame 12 under the control of the implement control unit 90. The implement control unit receives the transducer voltage signals and controls the electrohydraulic valves individual to retract the cylinders to ensure the descent of the level. Once the implement 8 is operating in the field, the controls of al can move from its detent positions to provide an off-center voltage to raise or lower a wing section 18 or 20 independently of the center section 16 for better control of level. If for any reason a Since the central section 16 is operating at a different level from the opposite side, the level control can be moved to provide an off-center voltage to change the positions of the wheel assemblies 22 and 30 relative to the assemblies 24 and 32 in the direction of the section level.

If intermediate depth control is desired, for example, during turns or when passing over a waterway, the operator simply activates the intermediate depth control. Multiple seals can also be provided to establish the work depths easily selectable for different conditions.

To raise the implement 8, the operator selects the lift function at the selective control valve 200, and the feedback system ensures that the cylinders extend generally in unison to raise the implement in a level condition. Off-center control provides a reference level reset and an override for normal selective control valve operation without depth and offset controls.

If a fault occurs in the controllers, the electro-hydraulic valves or the wiring, the operator can continue the operation by pivoting the valves 62-72 in the open position by holding or activating the mechanical stops. 180, and bypassing the added implement valve 80, if used, by disconnecting the lines 81 and 82 from location 182 and disconnecting them at location 184 for direct control of the cylinders from the selective control valve 79.

Having described the preferred embodiment it will be apparent that various modifications can be made without departing from the scope of the invention as defined in the appended claims.

Claims (20)

R E I V I ND I C A C I O N S

1. In an agricultural implement having a tool support frame that extends transversely with the front and rear portions and adapted for forward movement on the ground by means of a towing vehicle and supported by a plurality of transversely spaced lifting assemblies to raise and lower the frame in relation to the ground, a survey control system comprising: hydraulic cylinders connected to the lifting assemblies; a control valve structure connected to the hydraulic cylinders and to a source of hydraulic fluid under selectively operable pressure to extend and retract the hydraulic cylinder to operate the lifting assemblies to raise and lower the frame; transducer members that respond to the operation of the lifting assemblies and provide output signals that depend on the position of the frame; an electronic control unit connected to the control valve structure and to the transducers and that responds to the output signals of the transducer to operate the hydraulic cylinders individually for the positioning of the frame in a preselected position relative to the ground; a deflection structure that facilitates the operation of the cylinders independently of the electronic control unit.

2. The survey control system as claimed in clause 1 characterized in that the control valve structure comprises an electrohydraulic valve connected between the source and each of the cylinders and the deflection structure includes a manual control of the electrohydraulic valve .

3. The lifting control system as claimed in clause 2 characterized in that the electrohydraulic valve proportional to provide a fluid flow that depends on the output signals of the transducers.

4. The survey control system as claimed in clause 1 characterized in that the transducer members include a transducer that provides a voltage that depends on the extension of the cylinders.

5. In an implement adapted for a forward movement on the ground and that includes a frame that extends transversely and that supports the tools of work in the land, the lifting assemblies supported by the frame and selectively placeable to raise and lower the tools between the elevated transport positions and the lowered work positions in the field and to vary the location of the work tools of the earth when the tools are in the work position in the field, the lifting assemblies include the individual hydraulic cylinders, A survey control system comprising: an electrohydraulic valve structure connected to the hydraulic cylinders; a source of hydraulic fluid under pressure; a selective control valve (SCV) that connects the electrohydraulic valve structure source, - transducers that provide transducer signals that depend on the position of each of the lift assemblies; an operator control unit (OCU) for provide the desired position signals; an implement control unit (ICU) having inputs connected to the transducers and to the operator control unit, and outputs connected to the electrohydraulic valve structure, wherein the implement control unit responds to the signals of the transducer and to the desired position signals for the automatic control of the valve structure for individually controlling the hydraulic cylinders and keeping the tools in the desired positions relative to the ground; wherein the electrohydraulic valve structure includes a closure for the operation of the hydraulic cylinders independently of the implement control unit so that the lifting control can be operated by the selective control valve if the automatic control is interrupted by a fault electrical in the lifting control system.

6. The lifting control system as claimed in clause 5, characterized in that the valve structure comprises a four-position and two-way valve.

7. The lifting control system such and as claimed in clause 6, characterized in that the closure includes a manually movable control for fixing the valve in an open position.

8. The survey control system as claimed in clause 6, characterized in that the valve structure comprises a proportional valve.

9. The survey control system as claimed in clause 5, characterized in that it includes an electrically controlled implement valve connected to the implement control unit and located between the source and the electrohydraulic valve structure, and also includes a structure of connector to bypass the implement valve for direct operation of the hydraulic cylinders by the selective control valve.

10. In an implement adapted for a forward movement on the ground and that includes a cross-sectional framework that holds the work tools in the ground, the lifting assemblies supported by the frame and selectively positionable to raise and lower the tools between high positions of transport and the positions of work in the field descended, and to vary the location of the tools of work in the ground when the tools are in the position of work in the field, the Lifting sets include the individual hydraulic cylinders, a lifting control system comprising: an electrohydraulic valve structure connected to the hydraulic cylinders; a source of hydraulic fluid under pressure; a control valve structure that connects the source of the electrohydraulic valve structure; a transducer structure that provides transducer signals that depend on the position of each of the lift assemblies; an implement control that responds to the transducer signals and that is connected to the electrohydraulic valve structure and that provides automatic control of the valve structure to control the hydraulic cylinders and maintain the tools in the desired positions relative to the ground; a deviation structure connected to the electrohydraulic valve structure and having a first position that facilitates automatic control and a second position that facilitates manual control of the cylinders from the control valve structure.

11. The lifting control system as claimed in clause 10 characterized in that the electrohydraulic valve structure comprises a valve body supporting a valve tool having an open position and a closed position, the deflection includes a fixing member that Secure the spool in the open position.

12. The lifting control system as claimed in clause 10 characterized in that the electrohydraulic valve structure includes a proportional valve and the fixing member secures the valve spool in a fully open position.

13. The lifting control system as claimed in clause 10, characterized in that the electrohydraulic valve structure comprises a proportional two-way and two-way valve.

14. The lifting control system as claimed in clause 10, characterized in that the electrohydraulic valve structure comprises a four-way, four-way valve.

15. The lifting control system as claimed in clause 10, characterized in that the electrohydraulic valve structure comprises a four-way valve with two positions.

16. The lifting control system as claimed in clause 10, characterized in that the electrohydraulic valve structure comprises a valve of the on-off type.

17. The lifting control system as claimed in clause 10 characterized in that the electrohydraulic valve structure includes a solenoid supported by the valve body, and the fixing member moves the solenoid to a position corresponding to the open position of the valve. valve spool.

18. The survey control system as claimed in clause 10 characterized in that the control valve structure comprises an implement control valve operably connected to the implement control and a selective control valve connected to the implement control valve , the survey control system further comprises a hydraulic line structure that provides a deviation of the implement control valve when manual control of the cylinders is facilitated.

19. In an implement adapted for forward movement on the ground and that includes a frame that extends transversely and that supports the tools of work on the ground, the lifting assemblies supported from the frame and selectively placeable to raise and lower the tools between the elevated transport positions and the lowered work positions in the field and to vary the location of the work tools of the earth when the tools are in the work position in the field,, the lifting assemblies include the individual hydraulic cylinders , a survey control system comprising: a source of hydraulic fluid under pressure; a valve structure connected to the hydraulic cylinders and to the source of hydraulic fluid under pressure; an implement control connected to the valve structure to automatically control the hydraulic cylinders; wherein the valve structure includes a closure that selectively secures the valve structure in an open position in an open position so that the Hydraulic cylinders can be operated from the source independently of the implement.

20. The lifting control system as claimed in clause 19 characterized in that the valve structure includes a solenoid operated valve having an open position and a closed position, the closure keeps the valve in the open position regardless of the condition of the solenoid. SUMMARY An implement lift with a plurality of individual electrohydraulically controlled lifting cylinders spaced over a tool frame including a deflection system to facilitate continued implement operation in the event of a wiring or electronics failure. The system includes an electrically controlled valve in each cylinder normally operated by an electronic controller but which can be manually fixed in an open position if there is a circuit failure so that the operator can control the implement from the tractor's selective control valve (SCV ). The hydraulic hoses are quickly disconnected, compatible with both the selective control valve of the tractor and the main electrohydraulic valve on the tractor are connected to the valve of the tractor for normal automatic operation but can easily be redirected to the valve connections of selective control for the control of the selective control valve when the cylinder valves are manually fixed in the open position.