Auxiliary flow valve system and method for managing load flow requirements for auxiliary functions on a tractor hydraulic system

Abstract

A system and method for managing hydraulic fluid load flow requirements for a tractor having a single pump hydraulic system. The system and method controls an implement hydraulic system and an auxiliary implement hydraulic system using a single hydraulic pump. The auxiliary flow valve system and method of the present disclosure gives precedence to the auxiliary functions so as to maintain full function of the auxiliary device. It also may supply a reduced flow, less than the maximum available from the system hydraulic pump to the auxiliary device. The remaining flow is available to the implement hydraulic system, with full flow being available to the implement when no auxiliary function is used. It also provides the ability to use a closed center valve in a load sensing system by bleeding flow pressure from the auxiliary hydraulic system.

What is claimed is: 
     
         1 . A process for managing fluid flow requirements for a tractor auxiliary hydraulic system and an implement hydraulic system connected in parallel to a single pump hydraulic system, comprising:
 obtaining an implement (pipelayer) fluid pressure requirement from the implement (pipelayer) hydraulic system;   obtaining an auxiliary implement fluid pressure requirement;   determining a greatest system pressure requirement;   transmitting the greatest system pressure requirement to the single pump hydraulic system;   obtaining fluid flow from the single pump hydraulic system to maintain the greatest system pressure requirement; and   maintaining fluid flow to satisfy the auxiliary implement fluid pressure requirement independent of the implement (pipelayer) system fluid pressure requirement.   
     
     
         2 . The process of  claim 1  further restricting the auxiliary fluid flow to the auxiliary hydraulic system to a predetermined valve. 
     
     
         3 . The process of  claim 2  wherein the single pump hydraulic system includes a maximum pump capacity and wherein said predetermined valve is less than said maximum pump capacity. 
     
     
         4 . The process of  claim 3  wherein the maximum pump capacity minus the predetermined valve of the restricted fluid flow to the auxiliary hydraulic system is greater than or equal to the fluid pressure requirement of the implement hydraulic system. 
     
     
         5 . The process of  claim 1  wherein fluid flow is provided to the implement hydraulic system necessary to satisfy the implement hydraulic system fluid pressure requirement. 
     
     
         6 . The process of  claim 5  wherein when the auxiliary hydraulic system is not in use the greatest system pressure requirement will be equal to the implement fluid pressure requirement. 
     
     
         7 . The process of  claim 1  wherein fluid flow is bled from the auxiliary hydraulic system. 
     
     
         8 . The process of  claim 2  wherein fluid flow is bled from the auxiliary hydraulic system. 
     
     
         9 . The process of  claim 8  wherein the fluid flow bled from the auxiliary hydraulic system is less than said predetermined valve. 
     
     
         11 . A process for managing fluid flow requirements for an auxiliary implement hydraulic system and an implement hydraulic system connected in parallel to a single pump hydraulic system, comprising:
 obtaining an implement fluid pressure requirement from the implement hydraulic system;   obtaining an auxiliary implement fluid pressure requirement from the auxiliary implement hydraulic system;   determining a greatest system pressure requirement;   transmitting said greatest system pressure requirement to the single hydraulic pump;   obtaining fluid flow from said single hydraulic pump to maintain said greatest system pressure requirement;   maintaining an essential operation fluid flow to satisfy said essential operation fluid pressure requirement independent of said implement fluid pressure requirement; and   restricting the auxiliary fluid flow to the auxiliary hydraulic system to a predetermined valve.   
     
     
         11 . The process of claim  10  wherein the single pump hydraulic system includes a maximum pump capacity and wherein said predetermined valve is less than said maximum pump capacity. 
     
     
         12 . The process of  claim 11  wherein the maximum pump capacity minus the predetermined valve of the restricted fluid flow to the auxiliary hydraulic system is greater than or equal to the fluid pressure requirement of the implement hydraulic system. 
     
     
         13 . The process of claim  10  wherein fluid flow is provided to the implement hydraulic system necessary to satisfy the implement hydraulic system fluid pressure requirement. 
     
     
         14 . The process of claim  10  wherein fluid flow is bled from the auxiliary hydraulic system. 
     
     
         15 . The process of  claim 14  wherein the fluid flow bled from the auxiliary hydraulic system is less than said predetermined valve.