Toolbar with hydraulic height control

Abstract

An agricultural toolbar has a center section and opposite wings which are horizontally foldable between transport and field positions. The toolbar has a hydraulic system which is very adaptable to many different hydraulically controlled features and options, without sacrificing the primary purpose of the system, which is accurately controlling the operating height of the toolbar, to achieve optimal planting depth of modern precision seed and fertilizer application systems.

1 . A hydraulic system for raising and lowering wings of an agricultural tool bar, each wing being supported by a wheel, comprising:
 a plurality of fluidly connected non-rephase hydraulic cylinders, with one of the cylinders connected to each wheel;   a control system operatively connected to the cylinders so as to control fluid flow to and from the cylinders; and   the wheels being independently raised and lowered relative to one another.   
     
     
         2 . The hydraulic system of  claim 1  further comprising a position sensor on each wing to sense a position of each wing and send a signal to the control system. 
     
     
         3 . The hydraulic system of  claim 1  further comprising a sensor to sense fluid flow direction to and from the cylinders. 
     
     
         4 . The hydraulic system of  claim 3  wherein the sensor is a pressure sensor. 
     
     
         5 . The hydraulic system of  claim 1  further comprising a position sensor on each wheel. 
     
     
         6 . The hydraulic system of  claim 5  further comprising a scale to determine payload weight based on signals from the position sensors and hydraulic pressure. 
     
     
         7 . The hydraulic system of  claim 1  further comprising a rail to supply oil to all the cylinders. 
     
     
         8 . The hydraulic system of  claim 1  further comprising a human machine interface (HMI) in communication with the control system. 
     
     
         9 . The hydraulic system of  claim 1  wherein fluid flow to and from the cylinders is controllable manually and electronically. 
     
     
         10 . The hydraulic system of  claim 1  wherein the fluid flow is automatically adjusted to raise and lower the wheels. 
     
     
         11 . The hydraulic system of  claim 1  wherein the control system is adapted to monitor a case drain pressure and alert an operator if the drain pressure is out of a normal range. 
     
     
         12 . A method of raising and lowering wings on an agricultural tool bar having wheels for each wing, comprising:
 controlling oil flow through non-rephase cylinders in a hydraulic system connected to the wheels to raise and lower the wheels independently of one another.   
     
     
         13 . The method of  claim 12  further comprising actuating the hydraulic system in response to signals from position sensors associated with each of the wheels. 
     
     
         14 . The method of  claim 12  further comprising determining fluid flow direction in each cylinder. 
     
     
         15 . The method of  claim 12  further comprising providing oil to the cylinders through a common rail. 
     
     
         16 . The method of  claim 12  further comprising controlling positions of the wheels with a human machine interface (HMI) in communication with a control system operatively connected to the cylinders. 
     
     
         17 . A hydraulic system for raising and lowering wings of an agricultural tool bar, each wing being supported by a wheel, comprising:
 a plurality of fluidly connected non-rephase hydraulic cylinders, with one of the cylinders connected to each of the wheels;   a control system operatively connected to the cylinders so as to control fluid flow to and from the cylinders; and   a sensor to sense fluid flow direction to and from the cylinders.   
     
     
         18 . The hydraulic system of  claim 17  wherein the wheels are raised and lowered independently of one another by controlled flow of fluid to the hydraulic cylinders. 
     
     
         19 . The hydraulic system of  claim 17  further comprising a position sensor on each wheel to sense a position of each wing and send a signal to the control system. 
     
     
         20 . The hydraulic system of  claim 17  further comprising a common rail to supply fluid to all the hydraulic cylinders.