阅读说明：本技术 开中位到开中位负载敏感转换阀和具有所述转换阀的液压系统 (Open to open neutral load sensitive shift valve and hydraulic system having the same ) 是由 杰西·奈特 加布里埃尔·斯托弗 于 2020-03-02 设计创作，主要内容包括：一种被配置成控制从液压泵到多个液压功能件的流动的开中位(OC)–开中位负载敏感(OCLS)转换阀和具有所述转换阀的液压回路。所述转换阀包括插装阀安装口、负载敏感端口、泵端口、第一功能件供应端口、第一功能件返回端口和下游端口。当OC阀筒插入所述插装阀安装口中时,无论负载敏感如何,所述泵端口和所述第一功能件供应端口都被连接,并且所述第一功能件返回端口和所述下游端口被连接。当OCLS阀筒插入所述插装阀安装口中并且检测到负载敏感时,所述泵端口和所述第一功能件供应端口被连接,并且所述第一功能件返回端口和所述下游端口被连接。当OCLS阀筒插入所述插装阀安装口中并且未检测到负载敏感时,所述泵端口、所述第一功能件返回端口和所述下游端口被连接。(An Open Center (OC) -Open Center Load Sensitive (OCLS) shift valve configured to control flow from a hydraulic pump to a plurality of hydraulic functions and a hydraulic circuit having the shift valve. The shift valve includes a cartridge mounting port, a load-sensitive port, a pump port, a first function supply port, a first function return port, and a downstream port. When an OC valve cartridge is inserted into the cartridge valve mounting port, the pump port and the first function supply port are connected, and the first function return port and the downstream port are connected, regardless of load sensitivity. When an OCLS valve cartridge is inserted into the cartridge mounting port and a load sensitivity is detected, the pump port and the first function supply port are connected, and the first function return port and the downstream port are connected. When an OCLS valve cartridge is inserted into the cartridge mounting port and no load sensitivity is detected, the pump port, the first function return port and the downstream port are connected.)

1. An Open Center (OC) -Open Center Load Sensitive (OCLS) shift valve configured to control flow from a hydraulic pump to first and second hydraulic functions, the OC-OCLS shift valve comprising:

a cartridge mounting port configured to retain one of an OC valve cartridge and an OCLS valve cartridge;

a load-sensitive port;

a pump supply port configured to connect to the hydraulic pump;

a first function supply port configured to connect to a supply line connected to the first hydraulic function;

a first function return port configured to connect to a return line connected to the first hydraulic function;

a first downstream port configured to connect to the second hydraulic function;

wherein when the OC valve cartridge is inserted into the cartridge mounting port, flow entering the OC-OCLS shift valve through the pump supply port is directed to the first function supply port and flow entering the OC-OCLS shift valve through the first function return port is directed to the first downstream port regardless of flow through the load sensitive port;

when the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is indicative of demand from the first hydraulic function, flow entering the OC-OCLS shift valve through the pump supply port is directed to the first function supply port and flow entering the OC-OCLS shift valve through the first function return port is directed to the first downstream port; and is

When the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is not indicative of demand from the first hydraulic function, flow into the OC-OCLS shift valve through the pump supply port and flow into the OC-OCLS shift valve through the first function return port are directed to the first downstream port.

2. An OC-OCLS switching valve as set forth in claim 1, further comprising: at least one additional downstream port, wherein any flow directed to the first downstream port is also directed to the at least one additional downstream port.

3. The OC-OCLS shift valve of claim 1, further comprising an internal load-sensitive flow path hydraulically connected to the load-sensitive port and the first function supply port.

4. An OC-OCLS shift valve as in claim 1, wherein the OC-OCLS shift valve acts as a priority valve when the OCLS valve cartridge is inserted into the cartridge valve mounting port.

5. An OC-OCLS shift valve as in claim 1, wherein the OC-OCLS shift valve functions as an unloader valve when the OCLS valve cartridge is inserted into the cartridge valve mounting port.

6. An OC-OCLS switching valve as set forth in claim 1, wherein:

the OC-OCLS switch valve acts as a priority valve when a first OCLS valve cartridge is inserted into the cartridge mounting port; and is

When a second OCLS valve cartridge is inserted into the cartridge valve mounting opening, the OC-OCLS switch valve acts as an unloader valve.

7. An OC-OCLS shift valve as claimed in claim 6, wherein the first hydraulic function is a steering circuit and the second hydraulic function is a transmission control circuit.

8. An OC-OCLS switching valve as set forth in claim 7, further comprising: an internal load-sensitive flow path hydraulically connected to the load-sensitive port and the first function supply port.

9. An OC-OCLS switching valve as set forth in claim 8, further comprising: at least one additional downstream port, wherein any flow directed to the first downstream port is also directed to the at least one additional downstream port.

10. A hydraulic circuit, comprising:

a hydraulic pump;

a first hydraulic function;

a second hydraulic function; and

an Open Center (OC) -Open Center Load Sensitive (OCLS) shift valve configured to control flow from the hydraulic pump to the first and second hydraulic functions, the OC-OCLS shift valve comprising:

a cartridge mounting port configured to retain one of an OC valve cartridge and an OCLS valve cartridge;

a load-sensitive port configured to connect to a load-sensitive line for the first hydraulic function;

a pump supply port configured to connect to the hydraulic pump;

a first function supply port configured to be connected to a supply line for the first hydraulic function;

a first function return port configured to connect to a return line for the first hydraulic function; and

a downstream port configured to connect to a supply line for the second hydraulic function;

wherein when the OC valve cartridge is inserted into the cartridge mounting port, flow entering the OC-OCLS shift valve through the pump supply port is directed to the first function supply port and flow entering the OC-OCLS shift valve through the first function return port is directed to the downstream port, regardless of flow through the load sensitive port;

when the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is indicative of demand from the first hydraulic function, flow entering the OC-OCLS shift valve through the pump supply port is directed to the first function supply port and flow entering the OC-OCLS shift valve through the first function return port is directed to the downstream port; and is

When the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is not indicative of demand from the first hydraulic function, flow into the OC-OCLS shift valve through the pump supply port and flow into the OC-OCLS shift valve through the first function return port are directed to the downstream port.

11. The hydraulic circuit of claim 10, wherein the first hydraulic function is a steering circuit and the second hydraulic function is a transmission control circuit.

12. The hydraulic circuit of claim 11, wherein the steering circuit comprises:

a manual steering circuit; and

an automatic drive system.

13. The hydraulic circuit of claim 12, wherein the steering circuit further comprises:

a steering cylinder;

wherein the manual steering circuit and the automatic drive system are coupled in parallel and hydraulically between the OC-OCLS switch valve and the steering cylinder.

14. The hydraulic circuit of claim 13, wherein the manual steering circuit includes a hydro-mechanical steering valve and the automatic drive system includes an electro-hydraulic steering valve, and the hydro-mechanical steering valve and the electro-hydraulic steering valve are coupled in parallel and hydraulically between the OC-OCLS shift valve and the steering cylinder.

15. The hydraulic circuit of claim 13, wherein the OC-OCLS shift valve further includes at least one additional downstream port, and any flow directed to the first downstream port is also directed to the at least one additional downstream port.

16. The hydraulic circuit of claim 13, wherein the OC-OCLS shift valve further includes an internal load-sensitive flow path hydraulically connected to the load-sensitive port and the first function supply port.

17. The hydraulic circuit of claim 13, wherein the OC-OCLS shift valve functions as a priority valve when the OCLS valve cartridge is inserted into the cartridge mounting port of the OC-OCLS shift valve.

18. The hydraulic circuit of claim 13, wherein the OC-OCLS shift valve functions as an unloader valve when the OCLS valve cartridge is inserted into the cartridge mounting port of the OC-OCLS shift valve.

19. The hydraulic circuit of claim 13, wherein:

when a first OCLS valve cartridge is inserted into the cartridge mounting port of the OC-OCLS switch valve, the OC-OCLS switch valve acts as a priority valve; and is

When a second OCLS valve cartridge is inserted into the cartridge valve mounting port of the OC-OCLS switch valve, the OC-OCLS switch valve acts as an unloader valve.

20. The hydraulic circuit of claim 19, wherein the OC-OCLS shift valve further includes an internal load-sensitive flow path hydraulically connected to the load-sensitive port and the first function supply port.

Technical Field

The present disclosure relates to hydraulic systems and, more particularly, to switching valves capable of switching hydraulic circuits between open center and open center load sensitive circuit types.

Background

Both open neutral (OC) and open neutral load sensitive (OCLS) circuits (also known as pressure compensation circuits) are established circuit types that are each established with a dedicated valve for one circuit type or the other. The switching of the hydraulic circuit between the OC and OCLS configurations currently requires significant hardware changes.

It would be desirable to be able to convert a hydraulic circuit from an OC configuration to an OCLS configuration, or vice versa, without requiring significant hardware changes. This may also enable a general tractor with a conventional on-center hydraulic system to be retrofitted to a steering system that allows for integrated vehicle guidance with less manpower and expense.

Disclosure of Invention

An Open Center (OC) -Open Center Load Sensitive (OCLS) shift valve configured to control flow from a hydraulic pump to a first hydraulic function and a second hydraulic function is disclosed. The OC-OCLS shift valve includes a cartridge valve mounting port, a load-sensitive port, a pump supply port, a first function return port, and a first downstream port. The cartridge mounting port is configured to retain one of an OC valve cartridge and an OCLS valve cartridge. The pump supply port is configured to be connected to the hydraulic pump. The first function supply port is configured to be connected to a supply line connected to the first hydraulic function, and the first function return port is configured to be connected to a return line connected to the first hydraulic function. The first downstream port is configured to connect to the second hydraulic function. When the OC valve cartridge is inserted into the cartridge mounting port, flow entering the OC-OCLS shift valve through the pump supply port is directed to the first function supply port and flow entering the OC-OCLS shift valve through the first function return port is directed to the first downstream port regardless of flow through the load sensitive port. When the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is indicative of demand from the first hydraulic function, flow through the pump supply port into the OC-OCLS shift valve is directed to the first function supply port and flow through the first function return port into the OC-OCLS shift valve is directed to the first downstream port. When the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is not indicative of demand from the first hydraulic function, flow through the pump supply port into the OC-OCLS shift valve and flow through the first function return port into the OC-OCLS shift valve are directed to the first downstream port. The first hydraulic function may be a steering circuit and the second hydraulic function may be a transmission control circuit.

The OC-OCLS shift valve may also include one or more additional downstream ports, wherein any flow directed to the first downstream port is also directed to the additional downstream ports. The OC-OCLS shift valve may further include an internal load-sensitive flow path hydraulically connected to the load-sensitive port and the first function supply port.

When inserted into the cartridge mounting port, the OCLS valve cartridge may cause the OC-OCLS switching valve to function as a priority valve, or an unloader valve, or another type of valve that supports load sensitive operation. When the first OCLS valve cartridge is inserted into the cartridge valve mounting port, the OC-OCLS switch valve can be used as a priority valve; and the OC-OCLS switching valve acts as an unloader valve when a second OCLS valve cartridge is inserted into the cartridge valve mounting port.

A hydraulic circuit is disclosed that includes a hydraulic pump, a first hydraulic function, a second hydraulic function, and an OC-OCLS shift valve configured to control flow from the hydraulic pump to the first and second hydraulic functions. The OC-OCLS shift valve includes a cartridge valve mounting port, a load-sensitive port, a pump supply port, a first function return port, and a downstream port. The cartridge mounting port is configured to retain one of an OC valve cartridge and an OCLS valve cartridge. The load sensitive port is configured to connect to a load sensitive line for the first hydraulic function. The pump supply port is configured to be connected to the hydraulic pump. The first function supply port is configured to be connected to a supply line for the first hydraulic function. The first function return port is configured to connect to a return line for the first hydraulic function. The downstream port is configured to be connected to a supply line for the second hydraulic function. When the OC valve cartridge is inserted into the cartridge mounting port, flow entering the OC-OCLS shift valve through the pump supply port is directed to the first function supply port and flow entering the OC-OCLS shift valve through the first function return port is directed to the downstream port regardless of flow through the load sensitive port. When the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is indicative of demand from the first hydraulic function, flow entering the OC-OCLS shift valve through the pump supply port is directed to the first function supply port and flow entering the OC-OCLS shift valve through the first function return port is directed to the downstream port. When the OCLS valve cartridge is inserted into the cartridge mounting port and flow through the load sensitive port is not indicative of demand from the first hydraulic function, flow through the pump supply port into the OC-OCLS shift valve and flow through the first function return port into the OC-OCLS shift valve are directed to the downstream port.

The first hydraulic function may be a steering circuit and the second hydraulic function may be a transmission control circuit. The steering circuit may include a manual steering circuit and an automatic drive system. The steering circuit may further include a steering cylinder, wherein the manual steering circuit and the automatic drive system are hydraulically coupled in parallel between the OC-OCLS shift valve and the steering cylinder. The manual steering circuit may include a hydro-mechanical steering valve, and the automatic drive system may include an electro-hydraulic steering valve, wherein the hydro-mechanical steering valve and the electro-hydraulic steering valve are hydraulically coupled in parallel between the OC-OCLS shift valve and the steering cylinder.

Drawings

The above-mentioned aspects of the present disclosure and the manner of attaining them will become more apparent, and the disclosure itself will be better understood by reference to the following description of embodiments of the disclosure taken in conjunction with the accompanying drawings, wherein:

FIG. 1 illustrates an exemplary embodiment of a vehicle including an OC-OCLS shift valve.

FIG. 2 illustrates an exemplary transaxle including an OC-OCLS shift valve;

FIGS. 3A and 3B illustrate left and right side views of an exemplary OC-OCLS shift valve manifold;

FIG. 4 illustrates an exemplary Open Center (OC) valve cartridge;

FIG. 5 illustrates an exemplary OC-OCLS shift valve in an OC configuration;

FIG. 6 illustrates an exemplary steering circuit for a vehicle with an OC valve cartridge inserted into an OC-OCLS shift valve;

FIG. 7 illustrates an exemplary Open Center Load Sensitive (OCLS) valve cartridge;

FIG. 8 illustrates an exemplary OC-OCLS switch valve in an OCLS configuration;

FIG. 9 illustrates an exemplary steering circuit for a vehicle in which an OCLS valve cartridge is inserted into an OC-OCLS shift valve using a priority valve type valve cartridge; and is

FIG. 10 illustrates an exemplary steering circuit for a vehicle in which an OCLS valve cartridge is inserted into an OC-OCLS shift valve using an unloader valve style valve cartridge.

Corresponding reference characters indicate corresponding parts throughout the several views.

Detailed Description

The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.

Both open neutral (OC) and open neutral load sensitive (OCLS) circuits (also known as pressure compensation circuits) are established circuit types that are each established with a dedicated valve for one circuit type or the other, and therefore they are not configurable without significant hardware changes. An open center-open center load sensitive switching valve would allow the hydraulic circuit to be configured as an Open Center (OC) or an Open Center Load Sensitive (OCLS) with significantly less hardware changes. The OC-OCLS switchover valve can be configured as an OC or OCLS circuit type, depending on the type of valve cartridge installed in the switchover valve manifold.

The open neutral-open neutral load sensitive switching valve may be used in many different hydraulic circuits (e.g., steering hydraulic circuits, suspension hydraulic circuits, etc.) that use a closed center valve. The OCLS steering circuit allows the closed center steering valve to be configurable with a fixed displacement hydraulic pump that allows the integrated tractor guidance system to be installed on the tractor.

In today's distributed and specialized manufacturing environment, vehicles and other large systems may have subsystems that are manufactured at different locations and then assembled at another location. For example, the transmission may be assembled in a transmission factory at one location and then shipped to a vehicle assembly factory at another location. The hydraulic pump for the steering circuit is typically installed at the transmission factory and has an OC or OCLS configuration. This requires the vehicle assembly plant to maintain an inventory of two different types of transmissions (OC configured transmissions and OCLS configured transmissions). This dual inventory increases costs and also places greater emphasis on accurate predictions of the demand for each configuration of tractor. The OC-OCLS shift valve will allow either hydraulic pump configuration to be installed at the transmission factory, and then the vehicle assembly factory can configure the hydraulic circuit of the transmission for the desired steering circuit option during vehicle assembly. This would allow for fewer transmission configurations at the transmission plant, fewer transmission inventories at the vehicle assembly plant, less emphasis on accurate predictions, while still providing the desired alternatives at the vehicle assembly plant.

In addition, by replacing the open center type valve cartridge with an open center load sensitive type valve cartridge, the open center-open center load sensitive switching valve will allow for simplified field switching of the hydraulic circuit. Changing the steering circuit may also require updating the steering valve to a closed-center steering valve.

The open neutral-open neutral load sensitive switch valve concept can be used to switch any open neutral hydraulic circuit to an open neutral load sensitive circuit. For example, a GPS controlled steering system may require an OCLS loop, while a standard manual steering system may use an OC loop. The OC-OCLS crossover valve can be packaged in any manifold design and used on any open center tractor where it is desired to add an integrated GPS controlled steering system. Additionally, the concepts may be applied to open neutral steering circuits for other vehicle types.

Fig. 1 illustrates an exemplary embodiment of a vehicle 100, in this example a tractor, that includes an engine compartment 110 holding an engine, an operator cab 120, front and rear wheels 130, and a tool 150. Wheels 130 support engine compartment 110 and operator cab 120 above the ground. In an alternative tractor embodiment, tracks may be used in place of wheels 130. The tool 150 is hydraulically powered and controlled by the tractor 100. Operator cab 120 includes controls for an operator to control tractor 100 (including engine, wheels 130, and other components of tractor 100), and may include controls for an operator to control tool 150. The engine provides power to turn the wheels 130 and propel the tractor 100. At least the front wheels 130 may be steerable to steer the tractor 100, and alternatively, both the front and rear wheels 130 may be steerable to steer the tractor 100. The operator cab 120 provides the operator with a view of the area being worked on by the tractor 100.

Fig. 2 illustrates an exemplary transaxle 200, with transaxle 200 including transmission and axle components, and typically in engine compartment 110 of vehicle 100. The transaxle 200 includes a rear wheel shaft 210, a power take-off unit (PTO)220, and an OC-OCLS shift valve 230. The rear wheels 130 are coupled to a rear axle 210. The hydraulic tool 150 may be coupled to the PTO 220.

FIG. 3A illustrates a left side view and FIG. 3B illustrates a right side view of an exemplary OC-OCLS shift valve 230. The OC-OCLS switching valve 230 includes a plurality of hydraulic coupling positions and a valve barrel plug 302 that can be replaced by a desired valve barrel. The plurality of hydraulic coupling positions include a steering load sense port 310, a transmission system pressure port 320, a diagnostic port 330, a pump supply port 340, a steering supply port 350, a transmission shift valve supply port 360, a transmission pressure transducer port 370, and a steering return port 390. The port may be a standard metric O ring port according to ISO 6149-1.

Fig. 4 illustrates an exemplary Open Center (OC) valve cartridge 400, and fig. 5 illustrates the OC-OCLS shift valve 230 in an OC configuration, wherein the OC valve cartridge 400 is inserted in place of the valve cartridge plug 302. In the OC configuration, the transmission system pressure port 320 connects flow from the steering return to the transmission control circuit 660. The diagnostic port 330 provides transmission pressure. The pump supply port 340 connects supply oil from the steering pump to the OCLS shift valve 230. In the OC configuration, the steering supply port 350 connects supply oil to the steering valve. The shift valve supply port 360 connects the supply oil from downstream of the priority valve to the transmission shift valve. The divert return port 390 connects the return flow from the divert valve.

The OC-OCLS shift valve 230 with the OC valve cylinder 400 installed can be described as a blanking valve (blanking valve) creating a single flow path such that oil entering the OC-OCLS shift valve 230 through the pump supply port 340 is directed to exit the OC-OCLS shift valve 230 through the diverter supply port 350 to supply the diverter valve, and oil returning from the diverter valve to the OC-OCLS shift valve 230 through the diverter return port 390 is directed to various downstream consumers through the transmission system pressure port 320 and the shift valve supply port 360.

FIG. 6 illustrates an exemplary steering and transmission hydraulic circuit 600 for the vehicle 100, wherein the OC valve cartridge 400 is inserted into the OC-OCLS shift valve 230, thereby placing it in the OC configuration. The OC-OCLS switching valve 230 in the OC configuration is represented by valve assembly 610. The steering and transmission hydraulic circuit 600 includes a steering pump 602, an OC-OCLS shift valve 610 (in an OC configuration), a steering valve supply line 612, a steering valve return line 614, a manual steering circuit 620, a steering valve 630, a steering cylinder 640, and a transmission control circuit 660. The steering pump 602 provides flow to the pump supply port 340 of the OC-OCLS manifold 610, and the pump supply port 340 directs flow to the steering valve supply line 612 through the steering supply port 350 of the OC-OCLS manifold 610. The steering valve supply line 612 provides flow to a steering circuit 620, the steering circuit 620 including an open center steering valve 630 and a steering cylinder 640. The steering valve 630 controls flow to the steering cylinder 640 if there is operator input to the steering valve. Otherwise, the flow passes through the neutral path of the diverter valve 630 and returns to the diverter return port 390 of the OC-OCLS valve 610 through the diverter valve return line 614. The return flow through the steering return port 390 is directed to the transmission system pressure port 320 and the shift valve supply port 360, which provides flow to the transmission control circuit 660, the transmission shift valve, and possibly other downstream consumers.

A typical manual steering system may use an open center hydraulic circuit 600 with a hydro-mechanical steering valve 630, where all hydraulic steering components are in-line. The automatic drive system may have an electro-hydraulic steering valve piped in parallel with the manual hydro-mechanical steering valve 630, which cannot be achieved by means of the open-center hydraulic circuit 600, but can be achieved by the open-center load-sensitive hydraulic circuit 700. The OC-OCLS shift manifold 230 enables the installation of a priority valve 500 to shift the hydraulic circuit from open-center to open-center load-sensitive, which enables the vehicle to be configured for OC or OCLS when the transmission is assembled to the vehicle. The assembly facility may install the appropriate valve cartridge 400 or 500 to configure the tractor to the desired hydraulic system. This enables manufacturing flexibility of the automatic drive system. Additionally, OC-OCLS conversion manifold 230 simplifies the service solution to update tractors from the OC system to the OCLS system to add an automated drive system after a customer purchases a tractor.

The OC-OCLS crossover manifold 230 may also reduce the preparation time for transmission production testing, which may require temporary plumbing to connect the steering pump 602 to the transmission circuit 660. The OC-OCLS crossover manifold 230 may be designed such that when the valve spool plug 302 is installed, oil is routed to the transmission circuit 660 at the transmission plant without the use of temporary tubing.

Fig. 7 illustrates an example Open Center Load Sensitive (OCLS) valve cartridge 500, and fig. 8 illustrates the OC-OCLS shift valve 230 in an OCLS configuration with an OCLS valve cartridge 500 inserted in place of the valve cartridge plug 302. In the OCLS configuration, the steering load sensing port 310 couples the load sensing of the steering valve and the automatic steering valve to the priority valve. In the OCLS configuration, the transmission system pressure port 320 connects flow from the priority valve to the transmission control circuit 660. The diagnostic port 330 provides transmission pressure. The pump supply port 340 connects supply oil from the steering pump to the OCLS shift valve 230. In the OCLS configuration, the steering supply port 350 connects the supply oil to both the steering valve and the automatic steering valve. The shift valve supply port 360 connects the supply oil from the priority valve to the transmission shift valve. In the OCLS configuration, the steering return port 390 connects return flows from the steering valve and the automatic steering valve.

The OC-OCLS shift valve 230, to which the OCLS valve cartridge 500 is mounted, is configured as a priority valve that meters oil from the pump supply port 340 to the steering supply port 350 or to various downstream consumers through the steering load sensitive port 310, the transmission pressure port 320, and the shift valve supply port 360 based on a load sensitive signal communicated from the steering valve through the steering load sensitive port 310. When there is demand from the steering system, the priority valve 230 will switch to route oil through the steering supply port 350 to the closed center steering valve or the automatic steering valve, otherwise the oil is directed to the steering load sense port 310, the transmission pressure port 320, and the shift valve supply port 360.

FIG. 9 illustrates an exemplary steering and transmission hydraulic circuit 700 for the vehicle 100, wherein the OCLS valve cartridge 500 is inserted into the OC-OCLS shift valve 230 so that it is in an OCLS configuration. The OC-OCLS switching valve 230 in an OCLS configuration is represented by a two position priority valve assembly 710, the two position priority valve assembly 710 also including an internal load sensitive flow path 720. The steering and transmission hydraulic circuit 700 also includes an automatic actuation system 730, the automatic actuation system 730 hydraulically coupled in parallel with a spool steering valve 630 between the OC-OCLS manifold 710 and the steering cylinder 640. In this configuration, the steering and transmission hydraulic circuit 700 is using the closed-center steering valve 630 and the closed-center EH steering valve 738 in parallel.

The steering and transmission hydraulic circuit 700 includes a steering pump 602, a manual steering circuit 620, a steering valve 630, a steering cylinder 640, and a transmission control circuit 660. The steering and transmission hydraulic circuit 700 also includes an OC-OCLS shift valve 710, an automatic drive system 730, a steering valve supply line 712, a steering valve return line 714, a load sense line 722, an automatic steering supply line 732, and an automatic steering return line 734 in an OCLS configuration. In this configuration, the OC-OCLS manifold 710 acts as a priority valve between the steering circuit 620, 730 and the transmission circuit 660.

When steering is used, the internal load sense line 720 positions the OC-OCLS priority valve 710 in the first position (shown). This directs flow from the steering pump 602 entering through the pump supply port 340 to the steering valve supply line 712 connected to the steering supply port 350. The steering valve supply line 712 provides flow to the steering valve 630 of the manual steering circuit 620 and also provides flow to the automatic drive system 730 through the automatic steering supply line 732. The steering valve 630 or the automatic drive system 730 controls the flow to the steering cylinder 640. The priority valve in the OC-OCLS valve assembly 710 may receive a dynamic load sensitive signal from either the manual steering circuit 620 or the automatic drive system 730. The dynamic load-sensitive signal from the manual steering circuit 620 may come from the connection point in the manifold between the internal load-sensitive line 720 and the steering valve supply line 712. The dynamic load sense signal from the automatic drive system 730 may be obtained through the load sense line 722. The priority valve 710 does not care which valve it receives the load sensitive signal from. The sensors on the steering column may detect operator inputs to the hydro-mechanical steering valve 630 of the manual steering circuit 620, which may override any inputs to the EH steering valve 738 of the automatic drive system 730. The dynamic load sense may flow at a substantially constant rate (e.g., about 1 Liter Per Minute (LPM)) through the internal load sense passage 720, via the load sense port 310, through the load sense line 722, to the EH steering valve 738, then to the tandem hydro-mechanical steering valve 630, and then back through the steering return 714. When there is no input from either of the steering valves 630 or 738, the pressure increase in the steering valve supply line 712 due to both steering valves 630, 738 being in the closed position switches the priority valve in the OC-OCLS manifold 710 to a second position that bypasses the manual steering circuit 620 and the automatic drive system 730. Blocking the dynamic load sensitive flow path in the hydro-mechanical steering valve 630 of the manual steering circuit 620 or the EH steering valve 738 of the automatic drive system 730 causes the priority valve 710 to switch back to the first position. From the steering cylinder 640, the flow is returned to the manual steering circuit 620 or the automatic drive system 730. The return flow through the manual steering circuit 620 is returned to the steering valve return line 714 and the return flow from the automatic drive system 730 is returned to the steering return port 390 of the OC-OCLS switching valve 710 through the automatic steering return line 734 and the steering valve return line 714. The return flow through the steering return port 390 is directed to the transmission system pressure port 320 and the shift valve supply port 360, which provides flow to the transmission control circuit 660, the transmission shift valve, and possibly other downstream consumers.

When steering is not used, the load sense line 722 passes dynamic load sense flow through both steering valves 630, 738 and back to the steering return line 714. When there is no input from either of steering valves 630 or 738, the priority valve in OC-OCLS manifold 710 moves to a second position that directs flow from steering pump 602, entering through pump supply port 340, through transmission system pressure port 320 and shift valve supply port 360 to transmission control circuit 660 and transmission shift valve. When both steering valves 630, 738 are in the closed position, flow through the steering return line 714 and the steering supply line 712 will stagnate on the closed steering valves 630, 738, so flow from the steering pump 602 will be directed toward the transmission control circuit 660 and the transmission shift valve only through the transmission system pressure port 320 and the shift valve supply port 360.

Dynamic load sensitivity (e.g., 1LPM flow) may be used in the steering system to control the priority valve. With the steering valve in the neutral position, the dynamic load sensitivity is routed to the tank through both the EH steering valve 738 and the hydro-mechanical steering valve 630, allowing the priority valve 710 to shift toward the second position. When the dynamic load sensitivity is blocked by a shut-off valve in the autopilot system 730 or by turning a steering wheel connected to the steering valve 630, the dynamic load sensitivity pressure moves the priority valve 710 back toward the first position as the pressure in the manual steering circuit 620 increases.

FIG. 10 illustrates another exemplary steering and transmission hydraulic circuit 1000 for the vehicle 100 in an OCLS configuration. The OC-OCLS switching valve 230 in this OCLS configuration is represented by a dump valve assembly 1010, the dump valve assembly 1010 also including an internal load sensitive flow path 1020. An alternate spool is used in the OC-OCLS switching valve 230 to provide the flow path described below for the unloader valve assembly 1010. The steering and transmission hydraulic circuit 1000 also includes an automatic actuation system 730, the automatic actuation system 730 being hydraulically coupled in parallel to the spool valve steering valve 630 between the OC-OCLS unloader valve 1010 and the steering cylinder 640. In this configuration, the steering and transmission hydraulic circuit 1000 is using the closed-center steering valve 630 and the closed-center EH steering valve 738 in parallel. The steering and transmission hydraulic circuit 1000 also includes a steering pump 602, a manual steering circuit 620, a steering valve 630, a steering cylinder 640, and a transmission control circuit 660. The steering and transmission hydraulic circuit 1000 further includes an OC-OCLS shift valve 1010, an automatic drive system 730, a steering valve supply line 712, a steering valve return line 714, a load-sense line 722, an automatic steering supply line 732, and an automatic steering return line 734 in this OCLS configuration. The OC-OCLS manifold 230 in this unloader valve configuration 1010 conceptually provides the same functionality as the priority valve configuration 710, allowing for manufacturing flexibility. The unloader valve mechanism to route oil to either the transmission system pressure port 320 or the steering supply port 350 is somewhat simplified, but by using a threaded cartridge valve, the ability to switch hydraulic circuits for the automatic drive system remains the same.

When steering is used, the internal load sense line 1020 positions the OC-OCLS unloader valve 1010 in a first position (shown). This directs flow from the steering pump 602 entering through the pump supply port 340 to the steering valve supply line 712 connected to the steering supply port 350. The steering valve supply line 712 provides flow to the manual steering circuit 620 and also provides flow to the automatic drive system 730 through an automatic steering supply line 732. The steering valve 630 or the automatic drive system 730 controls the flow to the steering cylinder 640. The OC-OCLS unloader valve 1010 can receive a dynamic load sense signal from the diverter valve 630 of the manual diverter circuit 620 or the automatic drive system 730. The dynamic load-sensitive signal from the manual steering circuit 620 may come from a connection point in the manifold between the internal load-sensitive line 1020 and the steering valve supply line 712. The dynamic load sense signal from the automatic drive system 730 may be obtained through the load sense line 722. The unloader valve 1010 does not care which valve it receives a load sensitive signal from. The sensors on the steering column may detect operator inputs to the hydro-mechanical steering valve 630 of the manual steering circuit 620, which may override any inputs to the EH steering valve 738 of the automatic drive system 730. The dynamic load sense may flow at a substantially constant rate (e.g., about 1LPM) through the internal load sense passage 1020, via the load sense port 310, through the load sense line 722, to the EH steering valve 738, then to the tandem hydro-mechanical steering valve 630, then back through the steering return 714. When there is no input from either of the steering valves 630 or 738, the pressure increase in the steering valve supply line 712 due to both steering valves 630, 738 being in the closed position switches the unloader valve 1010 to a second position that bypasses the manual steering circuit 620 and the automatic drive system 730. Blocking the dynamic load sensitive flow path in the hydro-mechanical steering valve 630 of the manual steering circuit 620 or the EH steering valve 738 of the automatic drive system 730 causes the priority valve 710 to switch back to the first position. From the steering cylinder 640, the flow is returned to the manual steering circuit 620 or the automatic drive system 730. The return flow through the manual steering circuit 620 is returned to the steering valve return line 714 and the return flow from the automatic drive system 730 is returned to the steering return port 390 of the unloader valve 1010 through the automatic steering return line 734 and the steering valve return line 714. The return flow through the steering return port 390 is directed to the transmission system pressure port 320 and the shift valve supply port 360, which provides flow to the transmission control circuit 660, the transmission shift valve, and possibly other downstream consumers.

When steering is not used, the load sense line 722 passes dynamic load sense flow through both steering valves 630, 738 and back to the steering return line 714. When there is no input from the steering valves 630 or 738, the unloader valve 1010 moves to a second position that directs flow from the steering pump 602, entering through the pump supply port 340, through the transmission system pressure port 320 and the shift valve supply port 360 to the transmission control circuit 660 and the transmission shift valve. When both steering valves 630, 738 are in the closed position, flow through the steering return line 714 and the steering supply line 712 will stagnate on the closed steering valves 630, 738, so flow from the steering pump 602 will be directed toward the transmission control circuit 660 and the transmission shift valve only through the transmission system pressure port 320 and the shift valve supply port 360.

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered as exemplary and not restrictive in character, it being understood that the illustrative embodiment(s) have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. It will be noted that alternative embodiments of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the invention as defined by the appended claims.