KR-102962265-B1 - CONTINUOUSLY VARIABLE VALVE DURATION CONTROL METHOD AND SYSTEM THEREOF

KR102962265B1KR 102962265 B1KR102962265 B1KR 102962265B1KR-102962265-B1

Abstract

A method for controlling the duration of a continuously variable valve and a system thereof are disclosed. A control method for a Continuously Variable Valve Duration (CVVD) system of a vehicle according to an embodiment of the present invention comprises: a) a step of predicting entry into a sleep mode according to the ignition off (IG OFF) of the vehicle; b) a step of determining whether to enter a memory location update logic that stores a current position in memory by monitoring the CVVD position and the amount of voltage drop of the actuator per reference time according to the operation of the actuator controlling the valve duration of the CVVD; c) a step of entering the sleep mode after performing the memory location update logic that deletes the previous position stored in memory and stores the current position if the amount of voltage drop does not exceed a set reference value; or d) a step of restricting entry into the memory location update logic and entering the sleep mode if the amount of voltage drop exceeds the reference value.

Inventors

김영민

Assignees

현대자동차 주식회사
기아 주식회사

Dates

Publication Date: 20260507
Application Date: 20210527

Claims (11)

A method for controlling a Continuously Variable Valve Duration (CVVD) system of a vehicle, a) A step of predicting entry into sleep mode based on the vehicle's ignition being turned off (IG OFF); b) a step of determining whether to enter a memory position update logic that stores the current position in memory by monitoring the CVVD position and the amount of voltage drop of the actuator per reference time according to the operation of the actuator controlling the valve duration of the above CVVD; c) a step of entering the sleep mode after performing the memory location update logic, which deletes the previous location stored in the memory and stores the current location, if the above voltage drop amount does not exceed a set threshold; or d) a step of restricting entry into the memory location update logic and entering the sleep mode if the above voltage drop amount exceeds the above reference value; A continuous variable valve duration control method including
In paragraph 1, Step a) above is, A continuous variable valve duration control method comprising the step of predicting entry into the sleep mode when the voltage of the actuator is 9 volts or less.
In paragraph 1, The above standard value A continuous variable valve duration control method in which the voltage drop time secured according to the above voltage drop amount is set to a value greater than the sum of the position deletion time required to delete the previous position stored in the memory and the position storage time required to store the current position.
In any one of paragraphs 1 through 3, Step d) above is, A continuous variable valve duration control method comprising the step of storing the previous position stored in the memory as is, and then transmitting the previous position to an upper engine controller upon the next start.
In paragraph 1, A continuous variable valve duration control method that identifies the operating status of the CCVD during the above monitoring and restricts entry into the memory location update logic when entering the above sleep mode if the operating status is non-operating.
In paragraph 1 or 5, A continuous variable valve duration control method that identifies the operating status of the CCVD during the above monitoring and, if it is in an operating state, deletes the previous position stored in memory in advance to secure the storage time of the current position.
In paragraph 1, Step d) above is, A continuous variable valve duration control method comprising the step of further determining whether the ambient temperature measured by a temperature sensor satisfies the vehicle standard low temperature condition below a set value, and if satisfied, restricting entry into the memory location update logic and entering the sleep mode.
In a vehicle's Continuously Variable Valve Duration (CVVD) system, Actuator for controlling the valve duration of CVVD (Continuously Variable Valve Duration); A position detection sensor for detecting a CVVD position according to the operation of the above actuator; and A CVVD controller that predicts entry into sleep mode following the vehicle's ignition off, monitors the CVVD position and the amount of voltage drop of the actuator per reference time according to the operation of the actuator, determines whether to enter a memory position update logic that stores the results in memory, and if the amount of voltage drop does not exceed a set threshold, performs the memory position update logic that deletes the previous position stored in memory and stores the current position, and then enters the sleep mode; wherein if the amount of voltage drop exceeds the threshold, it restricts entry into the memory position update logic and enters the sleep mode. A continuously variable valve duration system including
In paragraph 8, The above standard value A continuously variable valve duration system that is variably set according to the slope based on the voltage drop amount.
In Paragraph 9, The above standard value A continuous variable valve duration system in which the voltage drop time increases as the slope is gentler and the voltage drop time decreases as the slope is steeper.
In paragraph 8, The above CVVD controller A continuous variable valve duration system that further determines whether the ambient temperature measured by a temperature sensor satisfies the vehicle standard low temperature condition below a set value, and if satisfied, restricts entry into the memory location update logic and enters the sleep mode.

Description

Continuously Variable Valve Duration Control Method and System Thereof The present invention relates to a method and system for controlling a continuously variable valve duration, and more specifically, to a method and system for controlling the position of a continuously variable valve duration at low temperatures. Generally, internal combustion engines generate power by taking fuel and air into the combustion chamber and burning them. These engines control intake and exhaust valves to obtain maximum output at a specific rotational speed range (rpm). Conventional intake and exhaust valve control includes Continuously Variable Valve Timing (CVVT) technology, which controls the valve opening timing according to the generation sequence; Continuously Variable Valve Lift (CVVL) technology, which controls the valve opening amount; and Continuously Variable Valve Duration (CVVD) technology, which controls the valve opening period. Among these, the CVVD (Continuously Variable Valve Duration) system, which is applied to meet recent stricter fuel efficiency regulations, utilizes an actuator (or motor) and a valve lift. Therefore, unlike CVVT, which changes the timing of valve opening and closing while keeping the valve duration fixed, the valve duration can be varied according to the engine's operating state. Here, the position of the actuator controlling the valve duration can be defined as a short-side and a long-side, and appropriate engine start control is performed by referring to the position of the actuator when starting the vehicle. Accordingly, the CVVD system ensures starting performance during the next engine start by performing a logic (hereinafter referred to as "memory location update logic") that deletes the previous location previously stored in the non-volatile memory (EEPROM) and saves the current location when the engine is turned off (IGNITION OFF, hereinafter IG_OFF). However, cases have been raised where, when identifying the CVVD operating status in a vehicle's low-temperature environment (e.g., below -19 degrees) and entering sleep mode due to B+ OFF in a non-operating state, the above memory location update logic is not completed in time and the warning light illuminates. Since the illumination of such a warning light is a factor that causes unnecessary customer quality complaints, a solution for improvement is required. The matters described in this background technology section are written to enhance understanding of the background of the invention and may include matters that are not prior art already known to those skilled in the art to which this technology belongs. Figure 1 schematically shows the configuration of a CVVD system according to an embodiment of the present invention. FIG. 2 shows the operating state of a CVVD actuator according to a short position and a long position according to an embodiment of the present invention. FIG. 3 is a flowchart schematically illustrating a CVVD system control method according to an embodiment of the present invention. FIG. 4 shows a control situation referenced in the explanation of a CVVD system control method according to an embodiment of the present invention. Below, with reference to the attached drawings, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the invention. As used herein, singular forms are intended to include plural forms as well, unless explicitly otherwise indicated in the context. It will also be understood that the terms “include” and/or “include,” as used herein, specify the presence of the mentioned features, integers, steps, operations, components and/or components, but do not exclude the presence or addition of one or more of other features, integers, steps, operations, components, components and/or groups thereof. As used herein, the term “and/or” includes any one or all combinations of the associated items listed. Terms such as "vehicle" or "of a vehicle" as used herein, or other similar terms, are understood to include not only railway vehicles but also passenger cars, buses, trucks, and various commercial vehicles, including sports utility vehicles (SUVs). Throughout the specification, terms such as first, second, A, B, (a), (b), etc., may be used to describe various components, but said components shall not be limited by said terms. These terms are intended only to distinguish a component from other components, and the nature, order, or sequence of said component is not limited by said terms. Throughout the specification, when it is stated that one component is 'connected' or 'joined' to another component, it should be understood that it may be directly connected or joined to that other component, or that there may be other components in between. On the other hand, when it is stated that one component is 'directly connected