KR20110116542A - Dual-variable valve timing system and intake efficiency extracting method thereof - Google Patents

Abstract

Dual-Variable Valve / Timing System and Dual Dual-Variable Intake / Exhaust Valve Timing System to Deliver More Accurate Intake Efficiency in Dual-Variable Intake / Exhaust Valve Timing System with Engine Using Variable Intake Valve and Exhaust Valve Timing A method for deriving the intake efficiency of a variable intake / exhaust valve timing system is disclosed. The method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system of the present invention includes determining a current exhaust cam position corresponding to the exhaust valve, and corresponding to each of a plurality of preset exhaust cam positions. And selecting at least one intake efficiency basic table corresponding to the identified current exhaust cam position among a plurality of intake efficiency basic tables for deriving an intake efficiency default value according to the engine speed, and a current corresponding to the intake valve. Determining an intake cam position and a current engine speed, and deriving at least one intake efficiency default value according to the identified current intake cam position and the current engine speed based on the selected at least one intake efficiency basic table And deriving the intake efficiency according to the interpolation operation based on the derived at least one intake efficiency default value. It includes.

Description

Induction efficiency of dual-variable intake / exhaust valve timing system and dual-variable intake / exhaust valve timing system {DUAL-VARIABLE VALVE TIMING SYSTEM AND INTAKE EFFICIENCY EXTRACTING METHOD THEREOF}

The present invention relates to a method for deriving the intake efficiency of a dual-variable intake / exhaust valve timing system, and more particularly, to a variable in the dual-variable intake / exhaust valve timing system employing an engine using variable intake valve and exhaust valve timing. The present invention relates to a dual-variable intake / exhaust valve timing system and a dual-variable intake / exhaust valve timing system capable of deriving more accurate intake efficiency in consideration of various states of the intake valve and exhaust valve.

In recent years, internal combustion engines (engines) mounted in automobiles and the like have been proposed for variable valve timing devices that variably control the opening and closing timings of intake valves and exhaust valves according to driving conditions for the purpose of improving engine output, reducing exhaust gas and fuel economy. . Conventional dual-variable intake / exhaust valve timing systems employing an engine using a variable valve (intake and exhaust) timing system, according to engine speed and engine load, close the valve quickly at low rpm and slowly close the valve at rpm. By controlling the opening and closing timing of the intake and exhaust valves so as to control the ignition timing of the engine.

In this conventional dual-variable intake / exhaust valve timing system, the basic fuel injection amount is proportional to the intake air flow into the cylinder of the engine, and the intake air flow into the cylinder is obtained from a sensor measuring the internal pressure of the intake manifold. It can be calculated based on the intake efficiency based on the manifold pressure and the engine speed.

Therefore, the process of calculating the intake air amount in the conventional dual-variable intake / exhaust valve timing system is briefly described as follows.

First, the intake efficiency according to the engine speed and the position of the intake valve is derived based on the preset intake efficiency table, and the valve overlap between the intake valve and the exhaust valve and the correction amount according to the engine speed based on the preset intake efficiency correction table. Calculate the basic intake efficiency by adding the correction amount to the intake efficiency, and calculate the basic intake efficiency slice according to the engine speed and valve overlap based on the preset intake efficiency slice table.

Basic Intake Efficiency = Intake Efficiency + Correction Amount

Basic Intake Efficiency

And, the final intake efficiency and final intake effect intercept section are derived through the following basic equations.

Final Intake Efficiency = Basic Intake Efficiency * Atmospheric Pressure Correction * Temperature Correction

Final Intake Effect Section = Basic Intake Efficiency Section * Atmospheric Pressure Correction * Temperature Correction

Accordingly, the conventional dual-variable intake / exhaust valve timing system can calculate the intake air amount based on the intake efficiency according to the manifold pressure and the engine speed through the following equation.

Intake air volume = final intake efficiency * intake manifold pressure + final intake effect

However, the conventional dual-variable intake / exhaust valve timing system as described above has a predetermined two-dimensional one in consideration of the engine speed and the intake valve in deriving the intake efficiency based on calculating the basic intake efficiency. Use only the intake efficiency table. Therefore, since various opening and closing states of the exhaust valve as well as the intake valve cannot be considered, various valve overlaps cannot be corrected, and as a result, it is difficult to derive accurate intake efficiency. Therefore, the conventional dual-variable intake / exhaust valve timing system as described above is difficult to derive the accurate intake efficiency, and as a result, it is impossible to calculate the accurate intake air amount, so that the fuel injection amount, which is a very important factor for engine control, is accurately determined. It can cause problems that cannot be calculated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to determine a current exhaust cam position corresponding to the exhaust valve, and to intake air corresponding to each of a plurality of preset different exhaust cam positions. Selecting at least one intake efficiency basic table corresponding to the identified current exhaust cam position among a plurality of intake efficiency basic tables for deriving intake efficiency default values according to cam position and engine speed, and corresponding to the intake valve Determining a current intake cam position and a current engine speed, and deriving at least one intake efficiency default value according to the identified current intake cam position and the current engine speed based on the selected at least one intake efficiency basic table. And the intake efficiency according to the interpolation operation based on the derived at least one default value of the intake efficiency. By providing a method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system comprising the step of deriving, it is possible to derive more accurate intake efficiency in consideration of the various opening and closing state of the exhaust valve as well as the intake valve.

The present invention has been made in view of the above circumstances, and another object to be achieved in the present invention is to derive an intake efficiency default value according to an intake cam position and an engine speed corresponding to each of a plurality of preset different exhaust cam positions. A memory unit for storing a plurality of intake efficiency basic tables, and a current exhaust cam position corresponding to the exhaust valves to determine at least one intake efficiency basic table corresponding to the current exhaust cam position among the plurality of intake efficiency basic tables; Select at least one intake efficiency default value according to the current intake cam position and the current engine speed based on the selected at least one intake efficiency basic table, and interpolate the calculation based on the derived at least one intake efficiency default value. The dual variable intake / exhaust valve including a control device for deriving the intake efficiency according to Providing a priming system, it is to allow not only the intake valve can derive the correct intake efficiency than using a variety of opening and closing state of the exhaust valve.

A method for deriving the intake efficiency of a dual-variable valve timing system according to a first aspect of the present invention for achieving the above object is to determine a current exhaust cam position corresponding to the exhaust valve. step; At least one intake efficiency corresponding to the identified current exhaust cam position among the plurality of intake efficiency basic tables for deriving a default value of the intake efficiency according to the intake cam position and the engine speed corresponding to each of a plurality of preset exhaust cam positions Selecting a base table; Determining a current intake cam position and a current engine speed corresponding to the intake valve; Deriving at least one intake efficiency default value according to the identified current intake cam position and current engine speed based on the selected at least one intake efficiency basic table; And deriving the intake efficiency according to the interpolation operation based on the derived at least one intake efficiency default value.

Preferably, the selecting of the at least one intake efficiency base table corresponds to a transfer of the identified current exhaust cam position from among the plurality of intake efficiency base tables corresponding to each of a plurality of preset different exhaust cam positions. A first intake efficiency basic table corresponding to the preset exhaust cam position and a second intake efficiency basic table corresponding to the preset exhaust cam position corresponding to the current exhaust cam position identified after the selection may be selected.

The deriving of the at least one intake efficiency default value may include deriving a first intake efficiency default value according to the current intake cam position and a current engine speed determined in the selected first intake efficiency basic table, and selecting the selected intake efficiency default value. It is preferable to derive a second intake efficiency default value according to the current intake cam position and the current engine speed identified above in the intake efficiency basic table.

In the deriving of the intake efficiency, it is preferable to derive the intake efficiency according to the interpolation operation based on the derived first intake efficiency default value and the second intake efficiency default value.

Preferably, deriving the correction amount according to the current valve overlap and the engine speed based on the intake efficiency correction table for deriving the correction amount according to the valve overlap and the engine speed between the intake valve and the exhaust valve; And deriving a basic intake efficiency which is a basis for calculating the amount of intake air flowing into the cylinder of the engine based on the derived correction amount and the derived intake efficiency.

The dual-variable valve timing system according to the second aspect of the present invention for achieving the above object, the intake cam position and the engine rotation corresponding to each of a plurality of preset different exhaust cam position A memory unit for storing a plurality of intake efficiency basic tables for deriving intake efficiency default values according to numbers; And determining a current exhaust cam position corresponding to the exhaust valve, selecting at least one intake efficiency basic table corresponding to the current exhaust cam position from the plurality of intake efficiency basic tables, and selecting the at least one intake efficiency basic table. And a control device for deriving at least one intake efficiency default value according to a current intake cam position and a current engine speed, and deriving the intake efficiency according to interpolation operation based on the derived at least one intake efficiency default value. .

Accordingly, according to the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system and the dual-variable intake / exhaust valve timing system, at least one intake efficiency basic table selected in consideration of the current position of the exhaust valve is used. By deriving at least one default value of intake efficiency according to the engine speed and the current position of the intake valve, and interpolating the derived at least one intake efficiency default value to derive the intake efficiency, It is possible to derive a more accurate intake efficiency considering the valve overlap.

Therefore, according to the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system and the dual-variable intake / exhaust valve timing system of the present invention, the valve overlap according to various opening and closing states of the exhaust valve as well as the intake valve is more accurate. As the intake efficiency can be calculated, the accurate intake air amount can be calculated, and as a result, it is possible to provide the effect of accurately calculating the fuel injection amount, which is a very important factor for engine control.

1 is a schematic control block diagram of a dual-variable intake / exhaust valve timing system in accordance with a preferred embodiment of the present invention.
2 is a control flowchart of a method for deriving an intake efficiency of a dual-variable intake / exhaust valve timing system according to a preferred embodiment of the present invention.
3 is an exemplary view illustrating a plurality of different exhaust cam positions and current exhaust cam positions preset according to the present invention.

Hereinafter, with reference to Figure 1 will be described a preferred embodiment of a dual-variable intake / exhaust valve timing (Dual-Variable Valve Timing) system according to the present invention.

As shown in FIG. 1, the dual-variable intake / exhaust valve timing system of the present invention includes a cam signal corresponding to an engine load, an intake valve 25, and an exhaust valve 27 derived due to engine speed and various information. The control apparatus 10 which receives a back etc., the variable valve timing apparatus 20 which controls opening and closing of the intake valve 25 and the exhaust valve 27 with which the engine is equipped, and the memory part 30 are included.

The variable valve timing device 20 controls the opening and closing of the intake valve 25 and the exhaust valve 27 under the control of the control device 10.

The memory unit 30 stores a plurality of intake efficiency basic tables for deriving an intake efficiency default value according to the intake cam position and the engine speed in correspondence with each of a plurality of preset exhaust cam positions.

Here, the plurality of intake efficiency basic tables may be tested to calculate a preferred intake efficiency default value for each intake cam position and each engine speed at the corresponding exhaust cam position, respectively, corresponding to each of a plurality of preset exhaust cam positions. The table obtained through The format of each of the plurality of intake efficiency basic tables may correspond to the format of the table used to derive the intake efficiency in the conventional dual-variable intake / exhaust valve timing system.

Here, as shown in FIG. 3, a plurality of different exhaust cam positions (exhaust cam position 1 to exhaust cam position 5) are set in advance on the exhaust cam position ranging from the basic initial position of the exhaust valve 27 to the maximum advance angle. In addition, five intake efficiency basic tables corresponding to each of several different exhaust cam positions (exhaust cam position 1 to exhaust cam position 5) may be stored in the memory unit 30.

Of course, in addition to the plurality of intake efficiency basic tables, the memory unit 30 may store an intake efficiency correction table for deriving a correction amount according to the valve overlap between the intake valve 25 and the exhaust valve 27 and the engine speed. have. The intake efficiency correction table may also be a table obtained through experiments to calculate a correction amount for desirably correcting the intake efficiency default value for each valve overlap and engine speed. The format of the intake efficiency correction table may correspond to the format of the table used to derive the correction amount in the conventional dual-variable intake / exhaust valve timing system.

The control device 10 receives the engine load derived from the outside and the cam signal corresponding to the intake valve 25 and the exhaust valve 27 derived from the outside, and is suitable for the current state based on these. The engine is controlled by controlling the variable valve timing device 20 so as to control the opening and closing timing of the intake valve 25 and the exhaust valve 27. The control device 10 may be an engine control unit (ECU) which is an engine control device.

Referring to the control device 10 in more detail, the control device 10 receives the engine speed and the engine load periodically or continuously from the outside, or as a specific event occurs. In addition, the control device 10 also receives a cam signal from an external cam position sensor. Accordingly, the control device 10 can recognize the positions of the intake valve 25 and the exhaust valve 27 by determining the intake cam position corresponding to the intake valve 25 and the exhaust cam position of the exhaust valve 27. have.

The control device 10 first derives the intake efficiency in order to calculate the intake air amount which is the basis for calculating the fuel injection amount. The control apparatus 10 for this purpose grasps the current exhaust cam position corresponding to the exhaust valve 27 based on the cam signal, and selects the current exhaust cam position among the plurality of intake efficiency basic tables previously stored in the memory unit 30. Select at least one corresponding intake efficiency base table.

For example, as shown in FIG. 3, the current exhaust cam position corresponding to the exhaust valve 27 is determined based on the cam signal, and as a result, the current exhaust cam position is between the preset exhaust cam position 2 and the exhaust cam position 3. If it is determined that the position, the control device 10 corresponds to the current exhaust cam position identified from the plurality of intake efficiency basic tables corresponding to each of the plurality of different exhaust cam positions previously stored in the memory unit 30. Select at least one intake efficiency base table. That is, the control device 10 corresponds to the transfer of the current exhaust cam position identified from the plurality of intake efficiency basic tables corresponding to each of the plurality of different exhaust cam positions previously stored in the memory unit 30. The intake efficiency basic table 2 corresponding to the preset exhaust cam position 2 is selected as the first intake efficiency basic table, and the intake efficiency basic table 3 corresponding to the preset exhaust cam position 3 corresponding to the current exhaust cam position identified after Can be selected as the second intake efficiency basic table.

And the control apparatus 10 is based on the selected at least one intake efficiency base table, and at least according to the current intake cam position and the current engine speed corresponding to the intake valve 25 grasped | ascertained based on a cam signal. Deriving one intake efficiency default.

For example, according to the current exhaust cam position as shown in FIG. 3, the intake efficiency basic table 2 corresponding to the exhaust cam position 2 is designated as the first intake efficiency basic table. When selected as the second intake efficiency basic table, the control device 10 derives a first intake efficiency default value according to the current intake cam position and the current engine speed using the intake efficiency basic table 2, and calculates the intake efficiency basic value. Table 3 will be used to derive a second default intake efficiency based on the current intake cam position and current engine speed. Here, the derivation of the first intake efficiency default value according to the current intake cam position and the current engine speed using the intake efficiency basic table 2 is performed by the control device 10 using the intake efficiency table in the existing system. Corresponding to the method of deriving efficiency, detailed description thereof will be omitted. Of course, the same will be true of deriving the second intake efficiency default value using the intake efficiency basic table 3.

As such, the control device 10 that derives at least one intake efficiency default value (the first intake efficiency default value and the second intake efficiency default value) derives the intake efficiency according to the interpolation operation based on the derived at least one intake efficiency default value. .

That is, the control device 10 derives the intake efficiency according to the interpolation operation based on the derived first and second intake efficiency default values, and the interpolation operation used by the control device 10 is the following interpolation formula It is preferable to follow 1.

수식1

Equation 1

Accordingly, the control device 10 may derive the intake efficiency through the following calculation by substituting the first intake efficiency default value, the second intake efficiency default value, the exhaust cam position 2 and the exhaust cam position 3 according to the above-described interpolation formula (1). Can be.

Accordingly, the control device 10 uses the at least one intake efficiency basic table selected in consideration of the current position of the exhaust valve 27 to set the default value of the intake efficiency according to the engine speed and the current position of the intake valve 25. By deriving at least one and interpolating the derived at least one intake efficiency default value to derive the intake efficiency, the dual-variable intake / exhaust valve timing system according to the present invention is not only an intake valve 25 but also an exhaust valve 27. It is possible to derive more accurate intake efficiency considering valve overlap according to various open / close states.

Furthermore, after deriving the intake efficiency, the control device 10 calculates the valve overlap between the intake valve 25 and the exhaust valve 27 and the engine speed based on the intake efficiency correction table previously stored in the memory unit 30. Based on the derived correction amount and the derived intake efficiency, the basic intake efficiency based on the calculation of the intake air amount flowing into the cylinder of the engine can be derived. Here, the derivation of the correction amount corresponds to a method of deriving the correction amount according to the valve overlap and the engine speed in the existing system, and thus a detailed description thereof will be omitted.

Accordingly, the dual-variable intake / exhaust valve timing system according to the present invention is more accurate considering the valve overlap according to various opening and closing states of the exhaust valve 27 as well as the intake valve 25 derived by the control device 10. The basic intake efficiency derived based on the intake efficiency and the basic intake efficiency intercept calculated based on the preset intake efficiency intercept table according to the existing method for calculating the existing intake efficiency intercept, Intake efficiency and final intake effect intercept can be derived.

Final Intake Efficiency = Basic Intake Efficiency * Atmospheric Pressure Correction * Temperature Correction

Final Intake Effect Section = Basic Intake Efficiency Section * Atmospheric Pressure Correction * Temperature Correction

Intake air volume = final intake efficiency * intake manifold pressure + final intake effect

Of course, the final intake efficiency derived through calculation in the dual-variable intake / exhaust valve timing system according to the present invention was derived through the same calculation as the existing derivation calculation method, but the basic intake efficiency as a parameter is derived according to the present invention. Since the value depends on more accurate intake efficiency, the final intake efficiency derived from the dual-variable intake / exhaust valve timing system according to the present invention will also be more accurate intake efficiency considering the valve overlap compared to the conventional one. Since the intake air amount calculated accordingly is also improved in accuracy, according to the dual-variable intake / exhaust valve timing system according to the present invention, the accurate intake air amount can be calculated as a result of obtaining an accurate intake efficiency, resulting in an engine control. It can provide the effect of accurately calculating fuel injection amount, which is a very important factor.

Hereinafter, the control flow of the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system according to the present invention configured as described above will be described with reference to FIG. 2. Here, for the convenience of description, the configuration shown in FIG. 1 described above will be described with reference to the corresponding reference numerals.

Firstly, according to the present invention, the dual-variable intake / exhaust valve timing system is configured to obtain a plurality of default values for deriving intake efficiency default values according to the intake cam position and the engine speed corresponding to each of a plurality of preset different exhaust cam positions. Save the intake efficiency base table.

Here, the plurality of intake efficiency basic tables may be tested to calculate a preferred intake efficiency default value for each intake cam position and each engine speed at the corresponding exhaust cam position, respectively, corresponding to each of a plurality of preset exhaust cam positions. The table obtained through The format of each of the plurality of intake efficiency basic tables may correspond to the format of the table used to derive the intake efficiency in the conventional dual-variable intake / exhaust valve timing system. Here, as shown in Fig. 3, the dual-variable intake / exhaust valve timing system includes a plurality of different exhaust cam positions (exhaust cam position 1) on exhaust cam positions ranging from the basic initial position of the exhaust valve 27 to the maximum advance angle. -Exhaust cam position 5) can be preset, and five intake efficiency basic tables corresponding to each of several different exhaust cam positions (exhaust cam position 1 to exhaust cam position 5) can be stored in advance.

The dual-variable intake / exhaust valve timing system of the present invention is characterized in that the engine load and the intake valve 25 derived from the engine speed and various information from the outside periodically or continuously or as a specific event occurs. A cam signal or the like corresponding to the exhaust valve 27 is received. Accordingly, the dual-variable intake / exhaust valve timing system determines the positions of the intake valve 25 and the exhaust valve 27 by determining the intake cam position corresponding to the intake valve 25 and the exhaust cam position of the exhaust valve 27. It can be recognized.

Thus, according to the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system of the present invention, the intake efficiency is first derived to calculate the intake air amount based on the fuel injection amount. In the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system for this purpose, the current exhaust cam position corresponding to the exhaust valve 27 is determined based on the cam signal (S10). For example, the controller 10 determines the current exhaust cam position corresponding to the exhaust valve 27 based on the cam signal, and as shown in FIG. 3, the exhaust cam position at which the current exhaust cam position is preset is set. It can be seen that it is located between 2 and the exhaust cam position 3.

As such, when the current exhaust cam position is determined, the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system of the present invention includes at least one intake efficiency basic table corresponding to the current exhaust cam position among a plurality of stored intake efficiency basic tables. Select (S20). For example, as shown in FIG. 3, when it is determined that the current exhaust cam position is located between the preset exhaust cam position 2 and the exhaust cam position 3, the control device 10 may each store a plurality of different stored exhaust cam positions. Select the intake efficiency base table 2 corresponding to the preset exhaust cam position 2 corresponding to the previous of the current exhaust cam position identified from among the plurality of intake efficiency base tables corresponding to (eg, five) as the first intake efficiency base table. Then, the intake efficiency basic table 3 corresponding to the preset exhaust cam position 3 corresponding to the identified current exhaust cam position can be selected as the second intake efficiency basic table.

And, the method of deriving the intake efficiency of the dual-variable intake / exhaust valve timing system of the present invention grasps the current intake cam position and the current engine speed corresponding to the intake valve 25 grasped based on the cam signal ( S30), based on the at least one intake efficiency basic table selected in step S20, at least one intake efficiency default value is derived according to the current intake cam position and the current engine speed (S40). That is, for example, the intake efficiency basic table corresponding to the exhaust cam position 3 is the intake efficiency basic table 2 corresponding to the exhaust cam position 2 according to the current exhaust cam position as shown in FIG. 3 as the first intake efficiency basic table. When 3 is selected as the second intake efficiency basic table, the control device 10 derives the first intake efficiency default value according to the current intake cam position and the current engine speed using the intake efficiency basic table 2, The efficiency base table 3 will be used to derive a second default intake efficiency based on the current intake cam position and the current engine speed.

As such, when the at least one intake efficiency default value (the first intake efficiency default value and the second intake efficiency default value) is derived, the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system of the present invention is derived from at least one intake rate. Based on the efficiency default value, the intake efficiency is derived according to the interpolation operation (S50). That is, the control apparatus 10 may derive the intake efficiency through the following calculation by substituting the first intake efficiency default value, the second intake efficiency default value, the exhaust cam position 2 and the exhaust cam position 3 according to the above-described interpolation formula (1). Can be.

As described above, the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing method of the present invention uses the engine speed using at least one intake efficiency basic table selected in consideration of the current position of the exhaust valve 27. And deriving at least one intake efficiency default value according to the current position of the intake valve 25, and deriving the intake efficiency by interpolating the derived at least one intake efficiency default value, thereby not only the intake valve 25 but also the exhaust valve 27. It is possible to derive a more accurate intake efficiency considering the valve overlap according to the various open and close states.

Furthermore, the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system of the present invention, after deriving the intake efficiency, between the intake valve 25 and the exhaust valve 27 based on the pre-stored intake efficiency correction table. A correction amount according to the valve overlap and the engine speed may be derived (S60), and the basic intake efficiency based on the derived correction amount and the derived intake efficiency may be derived (S70). ). Here, the derivation of the correction amount corresponds to a method of deriving the correction amount according to the valve overlap and the engine speed in the existing system, and thus a detailed description thereof will be omitted.

Therefore, according to the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system of the present invention, a method of calculating the basic intake efficiency derived from the more accurate intake efficiency derived in step S50 and the existing basic intake efficiency intercept By using the basic intake efficiency intercept calculated based on the preset intake efficiency intercept table, it is possible to derive the final intake efficiency and the final intake efficiency section according to the existing method as follows.

Final Intake Efficiency = Basic Intake Efficiency * Atmospheric Pressure Correction * Temperature Correction

Final Intake Effect Section = Basic Intake Efficiency Section * Atmospheric Pressure Correction * Temperature Correction

Intake air volume = final intake efficiency * intake manifold pressure + final intake effect

Of course, the final intake efficiency derived through calculation in the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system according to the present invention was derived through the same calculation as the existing derivation calculation method, but the basic intake efficiency is a parameter. Since the value according to the more accurate intake efficiency derived according to the invention, the final intake efficiency derived from the present invention will also be a more accurate final intake efficiency considering the valve overlap than the conventional. Since the intake air amount calculated accordingly improves accuracy, according to the method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system according to the present invention, it is possible to calculate the accurate intake air amount as a result of deriving the accurate intake efficiency. Therefore, it is possible to provide the effect of accurately calculating the fuel injection amount, which is a very important factor in engine control.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above-described embodiments, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the following claims. Anyone skilled in the art will have the technical idea of the present invention to the extent that various modifications or changes are possible.

Deriving at least one intake efficiency default value according to the engine speed and the current position of the intake valve using the at least one intake efficiency basic table selected in consideration of the current position of the exhaust valve, and interpolating the derived at least one intake efficiency default value By deriving the intake efficiency of the present invention, the dual-variable intake / exhaust valve timing system and the dual-variable intake / valuation of the present invention can derive more accurate intake efficiency considering the valve overlap according to various opening and closing states of the exhaust valve as well as the intake valve. Applying the method for deriving the intake efficiency of the exhaust valve timing system can make a tremendous advance in the accuracy and reliability of the operation of vehicles and systems adopting the dual-variable intake / exhaust valve timing system and furthermore in terms of performance efficiency. Not only is there a sufficient likelihood of marketing or sales of the vehicle being applied, It is an invention with industrial applicability, since it can be clarified.

10: control device 20: variable valve timing device
25: intake valve 27: exhaust valve
30: memory

Claims (6)

In the method of deriving the intake efficiency of the dual-variable valve timing system,
Determining a current exhaust cam position corresponding to the exhaust valve;
At least one intake efficiency corresponding to the identified current exhaust cam position among the plurality of intake efficiency basic tables for deriving a default value of intake efficiency according to the intake cam position and the engine speed corresponding to each of a plurality of preset exhaust cam positions Selecting a base table;
Determining a current intake cam position and a current engine speed corresponding to the intake valve;
Deriving at least one intake efficiency default value according to the identified current intake cam position and current engine speed based on the selected at least one intake efficiency basic table; And
And deriving the intake efficiency according to the interpolation operation based on the derived at least one intake efficiency default value. The method of claim 1,
Selecting the at least one intake efficiency basic table,
A first intake efficiency basic table corresponding to a preset exhaust cam position corresponding to a previous of the identified current exhaust cam position among the plurality of intake efficiency basic tables corresponding to each of a plurality of preset different exhaust cam positions and the identified And selecting a second intake efficiency basic table corresponding to a preset exhaust cam position corresponding to the current exhaust cam position. The method of claim 2,
Deriving the at least one intake efficiency default value,
Deriving the first intake efficiency default value according to the current intake cam position and the current engine speed determined in the selected first intake efficiency basic table, and the current intake cam position and current identified in the selected second intake efficiency basic table A method for deriving the intake efficiency of the dual-variable intake / exhaust valve timing system, comprising deriving a default value of the second intake efficiency according to the engine speed. The method of claim 3, wherein
Deriving the intake efficiency,
The intake efficiency deriving method of the dual-variable intake / exhaust valve timing system, characterized in that to derive the intake efficiency according to the interpolation operation based on the derived first intake efficiency default value and the second intake efficiency default value. The method according to any one of claims 1 to 4,
Deriving a correction amount according to a current valve overlap and an engine speed based on an intake efficiency correction table for deriving a correction amount according to a valve overlap and an engine speed between the intake valve and the exhaust valve; And
And deriving a basic intake efficiency, which is a basis for calculating the amount of intake air flowing into the cylinder of the engine, based on the derived correction amount and the derived intake efficiency. Method of deriving intake efficiency. In a dual-variable valve timing system,
A memory unit for storing a plurality of intake efficiency basic tables for deriving intake efficiency default values according to intake cam positions and engine speeds corresponding to each of a plurality of preset exhaust cam positions; And
Grasp the current exhaust cam position corresponding to the exhaust valve, select at least one intake efficiency basic table corresponding to the current exhaust cam position from the plurality of intake efficiency basic tables, and select the at least one intake efficiency basic table. And a control device for deriving at least one intake efficiency default value according to the current intake cam position and the current engine speed, and deriving the intake efficiency according to the interpolation operation based on the derived at least one intake efficiency default value. Dual-Adjustable Intake / Exhaust Valve Timing System.

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