# US 10,309,272 B2 · Control method and system for stability of intermediate phase continuously variable valve timing system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,272 B2 - Document ID: US10309272B2 - Status: Granted - Kind: B2 - Application number: 15/622,257 - Filed: 2017-06-14 - Published: 2018-01-18 - Granted: 2019-06-04 - Earliest claimed: 2016-07-13 - Assignees: Hyundai Motor Company; Kia Motors Corporation - Applicants: Hyundai Motor Company; Kia Motors Corporation - Inventors: Bon-Chang Koo - Web page: https://patentgrep.com/patent/US10309272B2 ## CPC - F01L 1/3442: {using hydraulic chambers with variable volume to transmit the rotating force} - F01L 1/04: by means of cams, camshafts, cam discs, eccentrics or the like (F01L1/10 takes precedence) - F01L 13/00: Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations - F02D 41/1401: {characterised by the control or regulation method (F02D41/1473, F02D41/1477 take precedence)} - F02D 41/22: Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} - F01L 2800/00: Methods of operation using a variable valve timing mechanism - F01L 2800/11: Fault detection, diagnosis - F01L 2800/18: Testing or simulation - F02D 2041/001: {for engines with variable valve actuation} - F02D 2200/021: Engine temperature - F02D 2200/101: Engine speed - Y02T 10/40: Engine management systems - F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A control method for stability of an intermediate phase Continuously Variable Valve Timing (CVVT) system may include comparing an oil temperature of the intermediate phase CVVT system with a predetermined value, and interrupting an operation of controlling the CVVT system when the oil temperature is lower than the predetermined value, comparing an engine RPM with a predetermined value, and interrupting the operation of controlling the CVVT system when the engine RPM is lower than the predetermined value, and comparing an operating current of the CVVT system with a predetermined management value A when the operation of controlling the CVVT system is not interrupted. ## Claims ### Claim 1 A control method for stability of an intermediate phase Continuously Variable Valve Timing (CVVT) system, comprising: comparing an oil temperature of the intermediate phase CVVT system with a predetermined oil temperature value, and interrupting an operation of controlling the CVVT system when the oil temperature is lower than the predetermined oil temperature value; comparing an engine RPM with a predetermined RPM value, and interrupting the operation of controlling the CVVT system when the engine RPM is lower than the predetermined RPM value; and comparing an operating current of the CVVT system with a predetermined management value A when the operation of controlling the CVVT system is not interrupted. ### Claim 2 (depends on 1) The control method of claim 1, wherein, when the operating current of the CVVT system is lower than the predetermined management value A, a target Pulse Width Modulation (PWM) duty signal corresponding to an intermediate phase CVVT error value is outputted. ### Claim 3 (depends on 2) The control method of claim 2, wherein the intermediate phase CVVT error value is a difference between a target intermediate phase CVVT value and a current intermediate CVVT value. ### Claim 4 (depends on 1) The control method of claim 1, wherein, when the operating current of the CVVT system is greater than the predetermined management value A, the operating current of the CVVT system is compared with a predetermined management value B. ### Claim 5 (depends on 4) The control method of claim 4, wherein, when the operating current of the CVVT system is lower than the predetermined management value B, a target Pulse Width Modulation (PWM) duty signal corresponding to the oil temperature and the operating current of the CVVT system is outputted. ### Claim 6 (depends on 4) The control method of claim 4, wherein, when the operating current of the CVVT system is greater than the predetermined management value B, it is configured to be determined that a failure has occurred, and the operation of controlling the CVVT system is interrupted. ### Claim 7 A control system for stability of an intermediate phase Continuously Variable Valve Timing (CVVT) system, comprising: an RPM measurement device configured to measure an engine RPM; an oil temperature detecting device configured to detect an oil temperature of the intermediate phase CVVT system; an operating current detecting device configured to detect an operating current of the intermediate phase CVVT system; and a CVVT controller configured to compare the engine RPM measured by the RPM measurement device with a predetermined RPM value, compare the oil temperature detected by the oil temperature detecting device with a predetermined oil temperature value, and compare the operating current of the CVVT system with a predetermined management value of current. ### Claim 8 (depends on 7) The control system of claim 7, wherein, when the engine RPM and the oil temperature respectively exceeds the predetermined RPM value and the predetermined oil temperature value, the CVVT controller is configured to compare the operating current of the CVVT system measured by the operating current detecting device with a management value A. ### Claim 9 (depends on 8) The control system of claim 8, wherein, when the operating current of the CVVT system is lower than the management value A, the CVVT controller outputs a target Pulse Width Modulation (PWM) duty signal corresponding to an intermediate phase CVVT error value. ### Claim 10 (depends on 9) The control system of claim 9, wherein the intermediate phase CVVT error value is a difference between a target intermediate phase CVVT value and a current intermediate phase CVVT value. ### Claim 11 (depends on 8) The control system of claim 8, wherein, when the operating current of the CVVT system is greater than the predetermined management value A, the CVVT controller is configured to compare the operating current of the CVVT system with a predetermined management value B. ### Claim 12 (depends on 11) The control system of claim 11, wherein, when the operating current of the CVVT system is lower than the predetermined, management value B, a target Pulse Width Modulation (PWM) duty signal corresponding to the oil temperature and the operating current of the CVVT system is outputted. ### Claim 13 (depends on 11) The control system of claim 11, wherein, when the operating current of the CVVT system is greater than the predetermined management value B, it is configured to be determined that a failure has occurred, and an operation of controlling the CVVT system is interrupted. ### Claim 14 (depends on 11) The control system of claim 11, wherein, when the operating current of the CVVT system is greater than the predetermined management value B, the CVVT controller is configured to compare the operating current of the CVVT system with a predetermined management value C, is configured to determine that a failure has occurred, when the operating current is lower than the predetermined management value C, and interrupts an operation of controlling the CVVT system.