JP5668581B2 - Valve opening / closing control device - Google Patents

Description

  The present invention relates to a valve opening / closing control device for a camless engine in which a camshaft is abolished and an intake valve and an exhaust valve are electronically controlled, and a valve that prevents an engine cycle from being completed without opening the valve. The present invention relates to an open / close control device.

  In recent years, engine combustion control has become more sophisticated as the exhaust gas regulations on engines have been tightened and fuel efficiency has been increasing. As one type of combustion control, there is variable valve control that changes the opening / closing timing of the intake valve and the exhaust valve and the lift amount according to the operating state of the engine. In an engine having a camshaft, variable valve control for changing the opening / closing timing determined by the camshaft and the lift amount has already become widespread.

  On the other hand, the present inventor does not use a camshaft, but uses a hydraulic pressure controlled by a solenoid valve to operate an intake valve and an exhaust valve with an opening / closing timing and a lift amount that are not mechanically fixed to the crank angle. Research and development of less engine.

  FIG. 4 shows a valve opening / closing control device 401 used for the camless engine under research and development by the inventor. In the valve opening / closing control device 401, both the intake valve and the exhaust valve are the same.

  The valve body 402 inserted through the cylinder head is urged in the valve closing direction by a spring 403. A camless block attached to the cylinder head is provided with a hydraulic control chamber 404 for pressing the upper end side of the valve body 402 with operating oil to push down the valve body 402. Connected to the hydraulic control chamber 404 is a line 406 into which hydraulic oil from the valve opening solenoid valve 405 is introduced. Connected to the valve opening solenoid valve 405 is a line 408 through which hydraulic oil from a high-pressure hydraulic pump 407 that supplies high-pressure hydraulic oil is introduced. When a valve opening pulse signal, which will be described later, is input to the valve opening solenoid valve 405, the plunger 409 closing the line 406, 408 in the valve opening solenoid valve 405 retreats so that the high-pressure operating oil is hydraulically controlled. It is introduced into the chamber 404, and the valve body 402 is pushed down to open the valve. When the valve opening pulse signal disappears, the plunger 409 advances to close the line 406, 408, and the introduction of the working oil into the hydraulic control chamber 404 is stopped.

  Connected to the hydraulic control chamber 404 is a line 411 from a low-pressure supply unit 410 that stores low-pressure operating oil. The connection port is closed by an oil drain valve 414 attached to the plunger 413 of the valve closing solenoid valve 412. When a valve closing pulse signal to be described later is input to the valve closing solenoid valve 412, the oil drain valve 414 that has blocked the connection port is opened by the plunger 413, and the operating oil in the hydraulic control chamber 404 is released to the low pressure supply unit 410. Therefore, the valve body 402 is pushed up by the spring 403 so that the valve is closed.

  The high pressure hydraulic pump 407 is driven by the crankshaft 415. A crank angle pulley 416 for detecting a crank angle is attached to the crankshaft 415.

  A crank angle sensor 417 is provided facing the crank angle pulley 416. The cylinder head is provided with a lift amount sensor 418 that detects a lift amount (a protrusion amount into the cylinder) that is a displacement amount of the valve body 402. A hydraulic pressure sensor 419 for detecting the hydraulic pressure is provided on the hydraulic pressure line 408 from the high-pressure hydraulic pump 407.

  For valve opening / closing control, a program (software) is executed in a programmable digital arithmetic circuit (hereinafter referred to as ECM) 420 called an ECM (Engine Control Module), CPU (Central Processing Unit), or MPU (Micro Processor Unit). Done in The output of each sensor is input to the IO port of the ECM 420. In addition, a signal that the ECM 420 instructs to each unit from the IO port is output to each unit via the driver 421.

  There is one solenoid valve for opening 405 and one solenoid valve for closing 412 for one valve. Since there are two intake valves and two exhaust valves in one cylinder, the six-cylinder engine has 24 valves in total, and 48 solenoid valves.

  As shown in FIG. 5, the valve body 402 includes a shaft portion 422 provided through a cylinder head (not shown) from the inside of the hydraulic control chamber 404, and the diameter of the valve body 402 is increased at the tip of the shaft portion 422. It comprises an umbrella part 423 that blocks an intake / exhaust port (not shown) and a cotter 424 whose diameter is enlarged in the middle of the shaft part 422. An upper sheet 425 that covers the rear end of the spring 403 is in contact with the cotter 424. The tip of the spring 403 is supported by the cylinder head. As a result, when operating oil is introduced into the hydraulic control chamber 404, the valve body 402 moves (lifts) into the cylinder, and the umbrella portion 423 opens the cylinder and the port. When the oil drain valve 414 attached to the plunger 413 of the solenoid valve 412 for closing the valve opens the connection port between the hydraulic control chamber 404 and the line 411 from the low pressure supply unit 410, the valve body 402 is restored to the original by the force of the spring 403. Return. A magnet 426 is provided in accordance with a return position of the valve body 402 (a position where the umbrella portion 423 is completely blocked). The magnet 426 is for securing the valve body 402 stably at the return position by attracting the upper seat 425.

  As shown in FIG. 6A, the lift amount can be controlled. That is, by increasing or decreasing the amount of oil introduced into the hydraulic control chamber 404 according to the time width of the valve opening pulse signal applied to the valve opening electromagnetic valve 405, the distance by which the valve body 402 is pushed down, that is, the lift amount can be controlled. The valve closing operation is basically performed until the valve is fully closed (the umbrella portion 423 is completely shut off), and is not held halfway, so the time width of the valve closing pulse signal is the lift at the time of valve opening. It is preferable to set a long time with a sufficient margin for the amount.

  As shown in FIG. 6B, the valve opening timing can be changed. Further, as shown in FIG. 6C, the valve closing timing can be changed. The timing for opening and closing the valve is determined by how many crank angles the valve opening pulse signal and the valve closing pulse signal are output.

  Thus, in the camless engine, the opening / closing timing and the lift amount do not mechanically depend on the crank angle, but the opening / closing timing and the lift amount can be freely controlled by the pulse signal from the ECM 420. Actually, the ECM 420 obtains an appropriate opening / closing timing and lift amount based on engine parameters (for example, engine speed, intake / exhaust amount, exhaust gas concentration, output torque, fuel consumption) representing the engine state, and based on this. A valve opening pulse signal and a valve closing pulse signal are generated.

  In order for the valve body 402 to move at the opening / closing timing and lift amount calculated in the ECM 420, the electrical delay of the driver 421 and the valve opening solenoid valve 405 after the signal is output, the machine of the plunger 409 Multiple response delays, such as a delay in the movement of hydraulic oil from the line 408 to the hydraulic control chamber 404 via the line 408, a delay in the movement of the valve body 402 by the action of hydraulic pressure against the combustion chamber pressure and the spring 403, etc. The valve opening pulse signal and the valve closing pulse signal must be calculated according to the delay relational expression related to the delay factor. Such a delay relational expression with many factors complicates the calculation procedure, and therefore takes time when executed in an inexpensive ECM 420 having a general processing speed. Accordingly, it is desirable that the calculation of the opening / closing timing and the lift amount be started at a time sufficiently earlier than the output of the signal.

No. 02/079614

  In the valve opening / closing control device 401 of FIG. 4, the target lift given as the time width of the valve opening pulse signal when the intake / exhaust valve is opened due to fluctuations in the pressure of the operating oil, variations in the force of the spring 403, and the like. An error occurs between the amount and the actual lift amount detected by the lift amount sensor 418. When there is such an error, the valve cannot be opened as intended as shown in FIG. In order to obtain the actual lift amount according to the target lift amount, it is desirable to perform feedback control in which the target lift amount is corrected based on an error from the actual lift amount.

  However, since the various delays described above occur after the valve opening pulse signal is output until the valve starts to open (the valve body 402 starts to lift), the actual lift amount is set to the target lift amount within the engine cycle. Cannot be matched in real time. Therefore, the present inventor performs feedback control (PID control) in which the target lift amount (valve opening pulse signal width) of the next and subsequent engine cycles is increased or decreased by the correction amount calculated in the engine cycle.

  However, when the engine is in a high load operation, the pressure in the combustion chamber is higher in the exhaust stroke from the combustion process than in the low load operation. Since the valve body 402 is lifted against the combustion chamber pressure, it may not be lifted well if the pressure in the combustion chamber is high. Specifically, when the exhaust valve opens during the exhaust stroke, the exhaust valve is delayed in opening, the actual lift amount is insufficient, the opening is insufficient, or the valve does not open (hereinafter, valve opening failure) ) Occurs.

  Thus, when the above-described feedback control is performed when the actual lift amount is insufficient, the target lift amount is increased by the correction in the next and subsequent engine cycles, and the valve opening pulse signal width is expanded. Therefore, it can be expected that the actual lift amount will reach the target lift amount (hereinafter referred to as valve opening success) if the combustion chamber pressure is approximately the same as the previous time in the engine cycle after the next time. However, when the engine state is changing, for example, when the engine load is increasing, the combustion chamber pressure becomes higher than the previous time in the engine cycle after the next time, so the valve opening may fail again. .

  In the experiment, such a shortage of the actual lift amount sometimes occurred over a plurality of engine cycles, and valve opening failures continued during this time. However, if the exhaust valve fails to open continuously during engine operation, it leads to performance deterioration and engine damage, which is not preferable.

  In this experiment, since the actual lift amount continued to be insufficient over a plurality of engine cycles, the above-described feedback control was repeated and the integral term (or target lift amount) was considerably increased. For this reason, when the combustion chamber pressure started to decrease and the exhaust valve was successfully opened, the actual lift amount became excessive.

  Therefore, an object of the present invention is to provide a valve opening / closing control device that solves the above-described problems and prevents the engine cycle from being terminated while the valve opening has failed.

  In order to achieve the above object, the present invention provides a valve main body inserted into a cylinder head of an engine, a spring that urges the valve main body in a valve closing direction, and the valve main body from outside the cylinder head with working oil. A hydraulic control chamber that lifts the valve body into the cylinder against the spring and the cylinder pressure, a lift amount sensor that detects an actual lift amount of the valve body, and an operating oil in the hydraulic control chamber. A solenoid valve for opening the valve, a solenoid valve for closing the operating oil from the hydraulic control chamber, and a driver for operating each of the solenoid valve for opening and the solenoid valve for closing the valve. In the valve opening / closing control device, the target opening / closing timing and opening degree generation for generating the valve opening timing, the target lift amount and the valve closing timing for each engine cycle based on the engine state A positive drive start timing calculation unit that calculates a positive drive start timing, with the lift operation performed before the operation delay time from the driver to the valve body from the valve opening timing of the engine cycle as a positive drive, A positive drive time width calculation unit that calculates the time width of the positive drive so that the valve body is lifted to the target lift amount of the engine cycle (hereinafter referred to as the positive time width), and the lift operation that is performed when the valve opening fails is the secondary drive A secondary drive start timing calculation unit that calculates the start timing of the secondary drive, a secondary drive time width calculation unit that calculates a time width of the secondary drive (hereinafter referred to as a secondary time width), and the positive drive start timing The valve opening pulse signal is output to the driver until the time width, and then the operation delay time has elapsed When the actual lift amount detected by the lift amount sensor is less than the threshold value, it is determined that the valve has failed to open, and the sub-valve opening pulse from the sub-drive start timing of the engine cycle to the sub-time width is determined. When the actual lift amount detected by the lift amount sensor is greater than or equal to the threshold value, the valve opening pulse signal output unit that determines that the valve opening has succeeded and does not output the auxiliary valve opening pulse signal, and the engine A valve closing pulse signal output unit for outputting a valve closing pulse signal having a predetermined time width at a valve closing drive start timing which is before an operation delay time from the driver to the valve body from a valve closing timing of a cycle. .

  For the primary drive start timing calculation unit, the primary drive time width calculation unit, the secondary drive start timing calculation unit, and the secondary drive time width calculation unit, each calculation ends in advance earlier than the primary drive start timing. You may provide the calculation start part which starts a calculation with the set calculation start timing.

  And a threshold value setting unit that sets a threshold value for valve opening success / failure based on the target lift amount of the engine cycle.

  The present invention exhibits the following excellent effects.

  (1) The engine cycle is prevented from ending with the valve opening failure.

It is a block diagram of the valve opening / closing control apparatus which shows one Embodiment of this invention. 6 is a timing chart showing profiles of various amounts obtained when the valve opening / closing control device of the present invention is successfully opened. 6 is a timing chart showing profiles of various amounts obtained when the valve opening / closing control device of the present invention fails to open. It is a block diagram of the valve opening / closing control apparatus under research and development. It is an enlarged view of a valve body. (A) is a figure explaining variable lift amount, (b) is a figure explaining valve-opening timing variable, (c) is a figure explaining valve-closing timing variable.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the valve opening / closing control apparatus 1 according to the present invention is obtained by improving the software while keeping the hardware the same as the valve opening / closing control apparatus 401 of FIG. 4.

  That is, the valve opening / closing control apparatus 1 of the present invention generates a valve opening timing A1 (hereinafter, refer to FIG. 2 for variables and constants), a target lift amount S1, and a valve closing timing A2 for each engine cycle based on the engine state. The lift operation performed before the operation delay time D1 + Δ from the driver 421 to the valve body 402 from the target opening / closing timing and opening generation unit 2 and the valve opening timing A1 of the engine cycle is defined as the positive drive, and the timing tmain for starting the positive drive is A positive drive start timing calculation unit 3 to calculate, a positive drive time width calculation unit 4 to calculate a time width wmain of the positive drive so that the valve body 402 is lifted to the target lift amount of the engine cycle, and a valve opening failure The lift operation is the secondary drive, and the secondary drive start timing tsub The secondary drive start timing calculation unit 5 to be output, the secondary drive time width calculation unit 6 that calculates the time width wsub of the secondary drive, the primary drive start timing calculation unit 3, the primary drive time width calculation unit 4, and the secondary drive start timing calculation A calculation start unit 7 for causing the unit 5 and the sub drive time width calculation unit 6 to start calculation at a preset calculation start timing tcal so that each calculation ends earlier than the primary drive start timing tmain; and the engine cycle A threshold value setting unit 8 for setting a threshold value S2 of the valve opening success / failure based on the target lift amount S1, and a valve opening pulse signal from the positive drive start timing tmain to the positive time width wmain. Thereafter, when the operation delay time D1 + Δ elapses, the actual amount detected by the lift amount sensor 418 is detected. When the stroke amount is less than the threshold value S2, it is determined that the valve has failed to open, and a secondary valve opening pulse signal is output from the secondary drive start timing tsub of the engine cycle to the secondary time width wsub, which is detected by the lift amount sensor 418. When the actual lift amount is greater than or equal to the threshold value S2, it is determined that the valve has been successfully opened, and the valve opening pulse signal output unit 9 that does not output the auxiliary valve opening pulse signal is output from the driver 421 from the valve closing timing A2 of the engine cycle. A valve-closing pulse signal output unit 10 that outputs a valve-closing pulse signal having a predetermined time width at a valve-closing drive start timing tclose that is before the operation delay time D3 until the main body 402.

  Target opening / closing timing and opening generation unit 2, primary drive start timing calculation unit 3, primary drive time width calculation unit 4, secondary drive start timing calculation unit 5, secondary drive time width calculation unit 6, calculation start unit 7, threshold value The setting unit 8, the valve opening pulse signal output unit 9, and the valve closing pulse signal output unit 10 are provided as software in the ECM 420. The ECM 420 obtains an optimum value of the opening / closing timing and the lift amount optimum for the engine state according to a program written in advance, and generates a valve opening pulse signal and a valve closing pulse signal based on the optimum values. The engine parameters representing the engine state are known parameters that are used in common with other ECMs, such as a fuel injection ECM that performs engine fuel injection control, a gear shift ECM that performs shift control, and a vehicle ECM that controls various parts of the vehicle. is there. The optimum values of the opening / closing timing and the lift amount are the opening / closing timing and the lift amount that can maximize the engine performance such as the exhaust gas performance, the fuel consumption performance, and the torque performance in each engine state.

  In parallel with the control of the present invention, the ECM 420 uses the correction amount calculated based on the error between the target lift amount and the actual lift amount in the engine cycle, and the target lift amount (valve opening pulse signal for the next and subsequent engine cycles). It is preferable to perform feedback control in which the width is increased or decreased.

  The operation of the valve opening / closing control device 1 of the present invention will be described below with reference to FIGS.

  FIG. 2 is a timing chart at the time of valve opening success, and FIG. 3 is a timing chart at the time of valve opening failure. The waveform of the valve closing pulse signal output from the valve closing pulse signal output unit 10 of the ECM 420 to the driver 421 is shown in the lower stage, and the waveform of the valve opening pulse signal output from the valve opening pulse signal output unit 9 to the driver 421 is shown in the middle stage. The upper stage shows waveforms of the actual lift amount detected by the lift amount sensor 418, respectively.

  In the valve opening / closing control device 1, the target opening / closing timing and opening generation unit 2 generates a valve opening timing A1, a target lift amount S1, and a valve closing timing A2 for each engine cycle based on the engine state.

  Next, the calculation start unit 7 performs the calculation on the primary drive start timing tmain with respect to the primary drive start timing calculation unit 3, the primary drive time width calculation unit 4, the secondary drive start timing calculation unit 5, and the secondary drive time width calculation unit 6. The calculation is started at a preset calculation start timing tcal so as to end earlier. The calculation start timing tcal is set to a sufficiently early time by an experiment or the like so that the calculation is in time even in an engine state in which the positive drive start timing tmain is an early time.

  Next, the primary drive start timing calculation unit 3, the primary drive time width calculation unit 4, the secondary drive start timing calculation unit 5, and the secondary drive time width calculation unit 6 start their respective calculations. The calculation of the threshold setting unit 8 may be performed at this time.

  That is, the positive drive start timing calculation unit 3 calculates the positive drive start timing tmain that is before the operation delay time D1 + Δ from the driver 421 to the valve body 402 from the valve opening timing A1 of the engine cycle. Here, D1 is the time from when the valve opening pulse signal input to the driver 421 rises until the valve main body 402 starts to lift, and Δ is the time to lift the valve main body 402 from the start of the lift until it can be considered that the valve has been opened successfully. It's a margin. In the primary drive start timing calculation unit 3, these D1 and Δ are calculated by the delay relational expression described above.

  At the same time, the positive drive time width calculator 4 calculates the positive drive time width wmain so that the valve body 402 is lifted to the target lift amount S1 of the engine cycle. The calculation method follows the principle described in FIGS. 6 (a) to 6 (c).

  The secondary drive start timing calculation unit 5 calculates the secondary drive start timing tsub using the lift operation performed at the time of valve opening failure, and the secondary drive time width calculation unit 6 calculates the secondary drive time width wsub. . The start timing tsub of the secondary drive is preferably immediately after the timing for determining success / failure of valve opening. The time width wsub of the secondary drive is preferably smaller than the time width wmain of the primary drive. The method for calculating the time width wsub of the secondary drive follows the principle described with reference to FIGS. 6A to 6C, similarly to the method of calculating the time width wmain of the primary drive. Since it is desirable that the working oil is introduced into the hydraulic control chamber 404 and that the actual lift amount by the secondary drive is not larger than the target lift amount S1, the secondary time width wsub is shorter than the normal time width wmain. It is adjusted by experiment etc.

  The threshold value setting unit 8 sets a threshold value S2 of the valve opening success / failure based on the target lift amount S1 of the engine cycle. The threshold value S2 is, for example, a value that is smaller than the target lift amount S1 by a ratio set by experiment or the like. Alternatively, the threshold value S2 may be a fixed value that can be reliably regarded as a valve opening success.

  Since each of these calculations starts at the calculation start timing tcal, the calculation ends earlier than the main drive start timing tmain.

  When the time reaches the positive drive start timing tmain after the completion of each calculation, the valve-opening pulse signal output unit 9 outputs the valve-opening pulse signal to the driver 421 from the positive drive start timing tmain to the positive time width wmain. The valve-opening pulse signal amplified by the driver 421 is input to the valve-opening electromagnetic valve 405, and the plunger 409 closing the line 406, 408 in the valve-opening electromagnetic valve 405 is retracted, so that high-pressure operating oil is discharged. The valve body 402 is introduced into the hydraulic control chamber 404 and begins to lift.

  Thereafter, the valve opening pulse signal output unit 9 compares the actual lift amount detected by the lift amount sensor 418 with the threshold value S2 when the operation delay time D1 + Δ has elapsed from the positive drive start timing tmain. As shown in FIG. 2, when the actual lift amount is greater than or equal to the threshold value S2 at this time, the valve opening pulse signal output unit 9 determines that the valve opening is successful and does not output the auxiliary valve opening pulse signal. As shown in FIG. 3, when the actual lift amount is less than the threshold value S2 at this time, the valve opening pulse signal output unit 9 determines that the valve opening has failed and starts the sub time from the sub drive start timing tsub of the engine cycle. The auxiliary valve opening pulse signal is output up to the width wsub.

  Next, the valve closing pulse signal output unit 10 closes the valve for a predetermined time width wclose at the valve closing drive start timing tclose that is before the operation delay time D3 from the driver 421 to the valve body 402 from the valve closing timing A2 of the engine cycle. Outputs a pulse signal. The operation delay time D3 is calculated by the delay relational expression described above. The predetermined time width wclose may be a sufficiently long time, and a fixed value may be set by experiment or the like. The valve closing pulse signal amplified by the driver 421 is input to the valve closing solenoid valve 412, and the oil drain valve 414 that has blocked the connection port between the low pressure supply unit 410 and the line 411 is opened by the plunger 413, thereby controlling the hydraulic pressure. Since the working oil in the chamber 404 is released to the low pressure supply unit 410, the valve body 402 starts to return.

  Here, the effect of the secondary drive will be considered while comparing FIG. 2 and FIG.

  In the example of the valve opening success in FIG. 2, when the operation delay time D1 + Δ elapses from the positive drive start timing tmain, the actual lift amount becomes equal to or greater than the threshold value S2, and the actual lift amount increases to reach the target lift amount S1. Has reached. This is because, for example, when the engine is operating at a low load, the pressure in the combustion chamber is lower in the exhaust stroke from the combustion process than when operating at a high load, and the valve main body 402 is easily lifted by the force of the hydraulic control chamber 404. It depends on what was done. As described above, when the actual lift amount is equal to or greater than the threshold value S2, it is determined that the valve has been successfully opened, and therefore the auxiliary valve opening pulse signal is not output.

  When the profile of the actual lift amount shown in FIG. 2 is seen, it can be seen that the valve opening timing A1, the target lift amount S1, and the valve closing timing A2 generated by the target opening / closing timing and opening degree generation unit 2 are all achieved.

  In the example of the valve opening failure in FIG. 3, the actual lift amount is less than the threshold value S2 when the operation delay time D1 + Δ has elapsed from the positive drive start timing tmain. This is because, for example, when the engine is operating at a high load, the pressure in the combustion chamber is higher in the exhaust stroke from the combustion process than when operating at a low load, and the hydraulic control chamber 404 is intended to lift the valve body 402. Due to lack of power. Alternatively, when the engine load is increasing, the engine load will not increase even if the target lift amount in the current engine cycle is increased due to the actual lift amount in the previous engine cycle being insufficient due to the feedback control described above. The valve opening failure can occur even when the follow-up is impossible due to the suddenness.

  In this way, when the actual lift amount is less than the threshold value S2, it is determined that the valve has failed to open, so that the sub valve opening pulse signal is output from the sub drive start timing tsub to the sub time width wsub. At this time, since the operating oil has already been introduced into the hydraulic control chamber 404 by the valve opening pulse signal of the positive drive, the operating oil is additionally introduced by the valve opening pulse signal of the sub drive. Thereby, when the operation delay time D2 elapses from the sub drive start timing tsub, the valve body 402 starts to be lifted, and then the valve opening is successful. When the secondary drive is performed, the crank angle is more advanced than when the primary drive is performed, and thus the combustion chamber pressure may be reduced. In this case, the valve opening is likely to be successful. Further, when the positive drive is performed, the combustion chamber pressure gradually decreases if the valve is slightly opened (= the actual lift amount is less than the threshold value S2 but the exhaust leaks). Valve opening tends to succeed in the secondary drive.

  The actual lift amount profile (solid line) shown in FIG. 3 does not match the ideal profile (one-dot chain line), but the valve opening succeeded after the initial valve opening timing A1. I understand that.

  It should be noted that the time width differs between the valve opening pulse signal for the positive drive and the valve opening pulse signal for the auxiliary drive. This is because the hydraulic oil is introduced into the hydraulic control chamber 404 by the primary drive during the secondary drive. The amount of operating oil introduced in the secondary drive is preferably smaller than that in the primary drive, and the secondary time width wsub is preferably shorter than the primary time width wmain.

  In addition, in the secondary drive, since the lift is performed in a situation where the valve opening in the primary drive has failed, it is considered that the lift cannot be performed exactly as intended. In order to prevent the actual lift amount from becoming excessive at this time, it is desirable that the actual lift amount in the secondary drive is smaller than the target lift amount S1, as shown in FIG. From this point, it is preferable that the sub time width wsub is shorter than the main time width wmain.

  At this time, since the actual lift amount in the secondary drive is smaller than the target lift amount S1, when the lift amount feedback control is applied, the target lift amount S1 after the next time becomes larger, and the actual lift amount becomes excessive when the combustion chamber pressure decreases. There is a risk of becoming. In order to avoid this, when the secondary drive is executed, the feedback control is suspended or the coefficient is changed to keep the previous integral term so that the target lift amount S1 does not become too large. desirable.

  Next, the effect of starting the calculation of the start timing and time width of the primary drive and the secondary drive at the calculation start timing tcal will be considered.

  Since the calculation of the start timing and the time width is performed by calculating a delay relational expression related to a plurality of delay factors, the calculation procedure is complicated, and it takes time when executed in an inexpensive ECM 420 having a general processing speed. . If the calculation of the secondary drive is performed after the valve opening failure of the primary drive is recognized, the start timing of the secondary drive is delayed. In this respect, in the present invention, the start timing and time width of the secondary drive are calculated at the same time as the start timing and time width of the primary drive. It becomes possible to start. If the valve is successfully opened in the primary drive, the load on the ECM 420 does not increase because the secondary drive is not executed.

  The calculation start timing tcal is set so that the calculation of the primary drive and the secondary drive ends earlier than the start timing of the primary drive. The calculation start timing tcal is preferably, for example, several tens of degrees CA (crank angle) before the valve body 402 starts to lift.

  As described above, according to the valve opening / closing control device 1 of the present invention, even if the valve opening fails in the normal drive, the sub-drive is performed in the engine cycle. It is prevented from being terminated, and deterioration of engine performance and engine damage due to failure to open the exhaust valve are avoided.

  According to the valve opening / closing control apparatus 1 of the present invention, the calculation of the start timing and time width of the primary drive and the secondary drive is started at the calculation start timing tcal sufficiently earlier than the primary drive start timing tmain. Since all calculations have been completed, the calculation can be omitted when the valve opening fails, and the sub drive can be started more quickly than when the sub drive is calculated after recognizing the valve opening failure.

  According to the valve opening / closing control apparatus 1 of the present invention, each calculation is started at the calculation start timing tcal, so that each calculation can be executed in an inexpensive ECM 420 having a general processing speed. Therefore, an expensive ECM for high speed processing is not necessary.

  The valve opening / closing control device 1 of the present invention is preferably applied to an exhaust valve. This is because the exhaust valve is opened when the combustion chamber pressure is high. The present invention is effective when the intake valve is opened at a time when the combustion chamber pressure is high due to some auxiliary operation.

DESCRIPTION OF SYMBOLS 1 Valve opening / closing control apparatus 2 Target opening / closing timing and opening generation part 3 Positive drive start timing calculation part 4 Positive drive time width calculation part 5 Sub drive start timing calculation part 6 Sub drive time width calculation part 7 Calculation start part 8 Threshold value Setting unit 9 Valve opening pulse signal output unit 10 Valve closing pulse signal output unit

Claims (3)

A valve body inserted into the cylinder head of the engine;
A spring for urging the valve body in the valve closing direction;
A hydraulic control chamber that lifts the valve body into the cylinder against the spring and the pressure in the cylinder by pressing the valve body with operating oil from the outside of the cylinder head;
A lift amount sensor for detecting an actual lift amount of the valve body;
A solenoid valve for valve opening for introducing working oil into the hydraulic control chamber;
A solenoid valve for valve closing that discharges the operating oil from the hydraulic control chamber;
Drivers for operating the solenoid valve for opening and the solenoid valve for closing,
In the valve opening and closing control device comprising
A target opening / closing timing and opening generation unit for generating a valve opening timing, a target lift amount and a valve closing timing for each engine cycle based on the engine state;
A positive drive start timing calculation unit that calculates a positive drive start timing, with a lift operation performed before the operation delay time from the driver to the valve body from the valve opening timing of the engine cycle,
A positive drive time width calculation unit that calculates a time width of a positive drive (hereinafter referred to as a positive time width) so that the valve body is lifted to a target lift amount of the engine cycle;
A sub-drive start timing calculation unit that calculates the start timing of the sub-drive with the lift operation performed when the valve opening failure is set as the sub-drive,
A secondary drive time width calculation unit for calculating a time width of the secondary drive (hereinafter referred to as a secondary time width);
The valve opening pulse signal is output to the driver from the positive drive start timing to the positive time width, and then the actual lift amount detected by the lift amount sensor becomes the threshold value when the operation delay time has elapsed. If not, it is determined that the valve opening has failed, and a sub-valve opening pulse signal is output from the sub-drive start timing of the engine cycle to the sub-time width, and the actual lift amount detected by the lift amount sensor is the threshold value. When the value is greater than or equal to the value, it is determined that the valve has been successfully opened, and the valve opening pulse signal output unit that does not output the auxiliary valve opening pulse signal;
A valve closing pulse signal output unit that outputs a valve closing pulse signal having a predetermined time width at a valve closing drive start timing that is before an operation delay time from the driver to the valve body from the valve closing timing of the engine cycle. A valve opening / closing control device characterized by the above.   For the primary drive start timing calculation unit, the primary drive time width calculation unit, the secondary drive start timing calculation unit, and the secondary drive time width calculation unit, each calculation ends in advance earlier than the primary drive start timing. The valve opening / closing control device according to claim 1, further comprising a calculation start unit that starts calculation at a set calculation start timing.   The valve opening / closing control device according to claim 1 or 2, further comprising a threshold value setting unit that sets a threshold value of success or failure of valve opening based on a target lift amount of the engine cycle.