# US 7,610,989 B2 · Control system and a vehicle comprising the control system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,610,989 B2 - Document ID: US7610989B2 - Status: Granted - Kind: B2 - Application number: 10/904,788 - Filed: 2004-11-29 - Published: 2005-07-07 - Granted: 2009-11-03 - Earliest claimed: 2002-05-29 - Assignees: Volvo Construction Equipment AB - Inventors: Bo Vigholm; Lennart Strandberg - Web page: https://patentgrep.com/patent/US7610989B2 ## CPC - F15B 20/002: {Electrical failure} - B62D 1/22: Alternative steering-control elements, e.g. for teaching purposes - B62D 5/09: characterised by means for actuating valves - F15B 20/008: {Valve failure} - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract System for controlling at least one hydraulic cylinder (2, 3) having a first control valve unit (4) connected to the hydraulic cylinder for regulation thereof. A first operable control means (5) is included and which is adapted for controlling the first control valve unit. A second control valve unit (6) is also included that is connected to the hydraulic cylinder for regulation thereof, and a second operable control means (7) is further provided and which is adapted for controlling the second control valve unit. The system also includes means (23) for prioritizing the first control means. The prioritizing means (23) is controlled via hydraulics in such a way that the effect of the second control means (6) on the regulation of the hydraulic cylinder (2, 3) is at least substantially reduced as soon as the first control means (5) is operated. ## Claims ### Claim 1 A system for controlling at least one hydraulic steering cylinder, said system comprising: a first control valve unit connected to said hydraulic steering cylinder for regulation thereof, a first manually operable control means for controlling the first control valve unit; a second control valve unit connected to said hydraulic steering cylinder for regulation thereof, a second manually operable control means for controlling the second control valve unit; a hydraulic prioritization circuit for prioritizing said first control means over said second control means, said hydraulic prioritization circuit being controlled via hydraulics in such a way that the effect of the second control means on the regulation of the hydraulic steering cylinder is prevented by and during actuation of said first control means. ### Claim 2 (depends on 1) The system as recited in claim 1, wherein the second control valve unit comprises a directional valve that is connected to the hydraulic steering cylinder for said regulation thereof. ### Claim 3 (depends on 2) The system as recited in claim 2, wherein the prioritization circuit is configured to bring the directional valve of the second control valve unit into a position that has an effect on the regulation of the hydraulic steering cylinder that is at least substantially reduced regardless of the position of the second control means. ### Claim 4 (depends on 1) The system as recited in claim 1, wherein the prioritization circuit is connected to the first control valve unit in such a way that prioritization is initiated when the first control valve unit is moved from a neutral position. ### Claim 5 (depends on 1) The system as recited in claim 1, wherein the first and second control valve units are hydraulically interconnected via said prioritization circuit in parallel with said hydraulic steering cylinder. ### Claim 6 (depends on 1) The system as recited in claim 1, further comprising a pump that is adapted to deliver a pressure depending on a load to which the system is subjected. ### Claim 7 (depends on 1) The system as recited in claim 1, wherein the prioritization circuit comprises a prioritizing valve which is hydraulically connected to the second control valve unit for regulation of the latter. ### Claim 8 (depends on 7) The system as recited in claim 7, wherein the prioritization valve is hydraulically connected to the first control valve unit in such a way that the prioritizing valve is regulated when control of the first control valve unit takes place. ### Claim 9 (depends on 1) The system as recited in claim 1, wherein the prioritization circuit comprises a flow-sensing element which is connected to one of (a) a main line between the first control valve unit and a pump of the system and (b) a main line between the first control valve unit and a tank of the system for initiation of prioritization when there is a flow in the first control valve unit. ### Claim 10 (depends on 9) The system as recited in claim 9, wherein the flow-sensing element is configured to bring about a pressure difference on different sides of the prioritizing valve for moving the prioritizing valve and thereby constitutes a pressure-difference-generating element. ### Claim 11 (depends on 10) The system as recited in claim 10, wherein the pressure-difference-generating element comprises a throttle (36, 37) adapted for throttling the flow in the main line (38, 39) for bringing about a pressure difference upstream of the throttle relative to downstream of the throttle. ### Claim 12 (depends on 10) The system as recited in claim 10, wherein the pressure-difference-generating element comprises a spring-loaded back-up valve arranged on the main line. ### Claim 13 (depends on 12) The system as recited in claim 12, wherein the pressure-difference-generating element further comprises a throttle configured to equalize the pressure on the two sides of the back-up valve when there is no flow therethrough. ### Claim 14 (depends on 7) The system as recited in claim 7, wherein the prioritizing valve is connected to a line which is connected to a pump for controlling the prioritizing valve depending on the load. ### Claim 15 (depends on 1) The system as recited in claim 1, wherein the system comprises two hydraulic steering cylinders wherein a piston side of a first of the two hydraulic steering cylinders and a piston-rod side of a second of the two hydraulic steering cylinders are connected to a pump when one of the control valve units is arranged in a first position, and a piston-rod side of the first hydraulic steering cylinder and a piston side of the second hydraulic steering cylinder are connected to the pump when said one of the control valve units is arranged in a second position. ### Claim 16 A vehicle comprising: a front part and a rear part interconnected in an articulated manner, the parts being rotatable relative to one another around an articulation via two hydraulic steering cylinders arranged between the two parts; a control system for controlling the relative movement of the parts, the control system comprising a first control valve unit connected to said hydraulic steering cylinders for regulation thereof, a first operable control means for controlling the first control valve unit; a second control valve unit connected to said hydraulic steering cylinders for regulation thereof, a second operable control means for controlling the second control valve unit; a hydraulic prioritization circuit for prioritizing said first control means over said second control means, said hydraulic prioritization circuit being controlled via hydraulics in such a way that the effect of the second control means on the regulation of the hydraulic steering cylinder is prevented by and during actuation of said first control means. ### Claim 17 (depends on 16) The vehicle as recited in claim 16, wherein the vehicle is configured as a loading machine. ### Claim 18 A system for controlling at least one hydraulic steering cylinder, comprising: a first control valve unit which is connected to said hydraulic steering cylinder for regulation of the latter; a first operable control means which is adapted for controlling the first control valve unit; a second control valve unit which is also connected to said hydraulic steering cylinder for regulation of the latter; a second operable control means which is adapted for controlling the second control valve unit; means for prioritizing the first control means; wherein the second control valve unit comprises a directional valve which is connected to the hydraulic steering cylinder for regulation of the latter; and wherein the prioritizing means is controlled via hydraulics in such a way that the effect of the second control means on the regulation of the hydraulic steering cylinder is prevented by and during actuation of said first control means and wherein the prioritizing means is adapted, for prioritization, to bring the directional valve of the second control valve unit into a position in which its effect on the regulation of the hydraulic steering cylinder is at least substantially reduced, irrespective of the position of the second control means. ### Claim 19 A system for controlling at least one hydraulic steering cylinder to provide steering to an articulated vehicle, comprising: a first control valve unit which is connected to said hydraulic steering cylinder for regulation of the latter; a first manually operable control means which is adapted for controlling the first control valve unit; a second control valve unit which is also connected to said hydraulic steering cylinder for regulation of the latter; a second manually operable control means which is adapted for controlling the second control valve unit; and means for prioritizing the first manually operable control means; wherein the second control valve unit comprises a directional valve which is connected to the hydraulic steering cylinder for regulation of the latter; and wherein the prioritizing means is controlled via hydraulics in such a way that the effect of the second manually operable control means on the regulation of the hydraulic steering cylinder is prevented by and during actuation of said first manually operable control means and wherein the prioritizing means is adapted, for prioritization, to bring the directional valve of the second control valve unit into a position in which its effect on the regulation of the hydraulic cylinder is at least substantially reduced, irrespective of the position of the second control means. ### Claim 20 A system for controlling at least one hydraulic steering cylinder, comprising: a first control valve unit which is connected to said hydraulic steering cylinder for regulation of the latter; a first operable control means which is adapted for controlling the first control valve unit; a second control valve unit which is also connected to said hydraulic steering cylinder for regulation of the latter; a second operable control means which is adapted for controlling the second control valve unit; means for prioritizing the first control means; wherein the second control valve unit comprises a pilot-controlled directional valve which is connected to the hydraulic steering cylinder for regulation of the latter; and wherein the prioritizing means is controlled via hydraulics in such a way that the effect of the second control means on the regulation of the hydraulic steering cylinder is prevented by and during actuation of said first control means and wherein the prioritizing means is adapted, for prioritization, to at least equalize the pressure on opposite sides of the directional valve and thereby bring the directional valve of the second control valve unit into a position in which its effect on the regulation of the hydraulic steering cylinder is at least substantially reduced, irrespective of the position of the second control means. ### Claim 21 A system for controlling at least one hydraulic steering cylinder comprising: a first control valve unit which is connected to said hydraulic cylinder for regulation of the latter; a first operable control means which is adapted for controlling the first control valve unit; a second control valve unit which is also connected to said hydraulic steering cylinder for regulation of the latter; a second operable control means which is adapted for controlling the second control valve unit; and means for prioritizing the first control means; wherein the prioritizing means is controlled via hydraulics in such a way that the effect of the second control means on the regulation of the hydraulic steering cylinder is prevented by and during actuation of said first control means; and wherein the prioritizing means for this purpose comprises a flow sensing means connected to a main line between the first control valve unit and a pump which is adapted to provide the hydraulic steering cylinder with pressurized oil, or a main line between the first control valve unit and a tank which comprises the oil, in order to initiate the prioritization upon detection of a flow in the first control valve unit.