JPH11117778A - Engine control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control device for a vehicle capable of shortening a braking distance vehicle in decelerating the and improving driving ability. SOLUTION: An engine control device has a decelerating condition detecting means 53 to detect the decelerating operation of a vehicle during running and to detect the decelerating condition of the vehicle, an engine operating condition detecting means 50 to detect an engine operating condition and a valve control means to shorten at least one of valve opening periods for suction and exhaust valves 34, 42 in accordance with the detected decelerating condition and engine operating condition. The braking force of the engine can be controlled in accordance with the decelerating condition of the vehicle and the smooth deceleration of the vehicle can be provided. In this way, a braking distance is shortened and driving ability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for a vehicle engine, and more particularly to a control apparatus for a vehicle engine having an electromagnetic intake / exhaust valve control system for electrically automatically controlling the intake / exhaust valves of the vehicle engine. It relates to a control device.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 55-87835 discloses a three-dimensional three-dimensional cam capable of changing the opening / closing timing of an intake / exhaust valve and the valve lift according to the operating state of an internal combustion engine. There is a description that the intake / exhaust valve is sometimes fully closed by restricting or stopping the operation of the intake / exhaust valve, and deceleration is improved by the effect of the engine brake.

Japanese Patent Application Laid-Open No. Hei 2-5718 discloses that in a multi-cylinder internal combustion engine, the operation of intake / exhaust valves is stopped and closed during engine braking to produce a stronger engine braking effect. The description has been made.

[0004]

However, when the above-mentioned conventional technique is applied to a vehicle, the intake and exhaust valves are controlled to be fully closed at the time of deceleration regardless of the engine operating state and the vehicle speed. Sudden braking is applied when the vehicle enters a deceleration state, such as when the pedal is released or brakes are applied, and sudden acceleration is applied when the accelerator pedal is depressed to enter an acceleration state.

[0005] Therefore, in a driving state in which acceleration and deceleration are repeated, the driving becomes jerky, giving an uncomfortable feeling to the operator of the vehicle, and lacks drivability.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a vehicle engine control device capable of shortening a braking distance at the time of deceleration of a vehicle and improving drivability. Is to do.

[0007]

The present invention is based on the premise of a system in which opening and closing of intake and exhaust valves is controlled by an actuator using electromagnetic means, instead of a conventional valve operating mechanism including a camshaft and the like. That is, attention is paid to the fact that the intake / exhaust valve using this electromagnetic actuator can freely set the opening / closing timing.

In a conventional valve train using a camshaft or the like, the opening and closing operations of the intake and exhaust valves are linked with the crankshaft of the engine, and the opening and closing timing is always constant with respect to the position of the piston of the engine. , Could not be set freely. Also, in recent years, a variable valve actuation mechanism capable of changing the opening / closing timing by shifting the phase of the camshaft or changing the lift amount according to the operating conditions has been developed, but the changing of the opening / closing timing has structural limitations. In addition, it was impossible to change the operation cycle by operating the engine without being linked to the crankshaft.

However, the opening and closing timing can be easily set arbitrarily by driving the intake / exhaust valve using the electromagnetic actuator. Therefore, in the present invention, an electromagnetic actuator capable of arbitrarily setting the opening / closing timing of the intake / exhaust valve in accordance with the operating state of the engine or the like is used.

The vehicle engine control device according to the first to third aspects of the present invention, when detecting a deceleration operation for decelerating a running vehicle, the amount of depression of a brake pedal or the amount of return of an accelerator pedal. Deceleration status detection means for detecting the deceleration status of the vehicle, engine operation status detection means for detecting the engine operation status based on the engine speed, etc. Valve control means for performing control to shorten at least one of the valve opening periods from a normal valve opening period. Then, when the vehicle enters the deceleration operation state, the valve opening period is shortened according to the deceleration state and the engine operation state.

Accordingly, the amount of intake and exhaust of the engine is reduced in accordance with the deceleration state of the vehicle and the operating state of the engine, and the vehicle is braked by the engine, that is, the so-called engine brake is applied in consideration of the deceleration state and the operating state of the engine. Will be done. As a result, the vehicle can be smoothly decelerated, and drivability can be improved. Further, in combination with the brake operated by the operator, the braking force can be appropriately increased, and the braking distance can be shortened.

According to a fourth aspect of the present invention, when the deceleration state is detected, the valve control means sets the opening period of the intake valve in the intake stroke of the engine in accordance with the deceleration state and the engine operating state. Control is performed such that the intake valve is opened and the intake valve is opened immediately after the start of the intake stroke.

According to a fifth aspect of the present invention, when the deceleration state is detected, the valve control means changes the opening period of the exhaust valve in the exhaust stroke of the engine between the deceleration state and the engine operating state. The exhaust valve is controlled so that the opening timing of the exhaust valve is set to just before the end of the exhaust stroke.

As a result, the fuel vaporization and combustion of the engine during deceleration can be promoted to the utmost, and the compression period during the exhaust stroke can be lengthened to make the engine brake most effective. Therefore, the engine brake in the deceleration state can be effectively used, the vehicle can be smoothly decelerated, and the drivability can be improved.

According to a sixth aspect of the present invention, the valve control means controls the valve opening period so as to gradually reduce the valve opening period as time elapses from the start of the deceleration operation state. As a result, the braking force by the engine brake is small at the start of the control, and gradually increases as the control time increases. Therefore, the initial braking force can be reduced, and the shock due to deceleration can be reduced.

According to a seventh aspect of the present invention, there is provided a control system for a vehicle engine, wherein the vehicle has an automatic transmission, wherein the automatic transmission directly connects or releases an output shaft of the engine and an input shaft of the transmission under a predetermined condition. Is provided.

When the deceleration operation is detected, the lock-up mechanism is controlled to be directly connected together with the opening and closing control of the intake and exhaust valves. Therefore, the braking force of the engine brake can be directly transmitted to the road surface via the driving wheels, and the braking distance can be reduced.

According to the present invention, there is provided an automatic switching system for a vehicle engine, wherein the vehicle has two types of drive systems, two-wheel drive and four-wheel drive, and the drive system is automatically switched according to the driving state. Has a mechanism. When the deceleration operation is detected, the automatic switching mechanism forcibly switches the drive system to the four-wheel drive system together with the opening / closing control of the intake and exhaust valves.

Therefore, the braking force by the engine brake can be distributed to the four driving wheels, so that the braking force can be transmitted to the road surface in a well-balanced manner. This can reduce tire slip and the like, so that the braking distance of the vehicle can be reduced with a stronger braking force.

According to a ninth aspect of the present invention, there is provided a vehicle engine control device, comprising: a forward monitoring mechanism for monitoring the front of the vehicle in a running state; a dangerous element determining means for determining the presence or absence of a forward dangerous element by the forward monitoring mechanism; A vehicle state detecting means for detecting a distance to the dangerous element and a driving state of the vehicle when the element determining means determines that there is a dangerous element; and at least one of an intake valve and an exhaust valve according to the detected vehicle state. Valve control means for performing control to shorten the valve opening period.

Therefore, when a danger element is detected by the forward monitoring mechanism, the control for shortening the valve opening period is performed according to the vehicle condition, so that the braking is performed very quickly and safely.
Collision can be avoided and the vehicle can be safely stopped.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic overall configuration diagram of an automobile engine, for example, a horizontally opposed engine, to which a vehicle engine control device according to the present invention is applied. As shown, the engine body 10 includes a plurality of cylinders 1.
1 and a cylinder head 14 having a plurality of combustion chambers 32. Each combustion chamber 32 communicates with the intake passage 16 and the exhaust passage 18, respectively.

In the intake passage 16, in order from the upstream side,
An intake chamber 20, an air cleaner 22 for removing dust from the air, and a throttle valve 26 for controlling an intake air amount Q in accordance with a depression amount of an accelerator pedal (not shown) are provided.

The downstream side of the intake passage 16 is connected to an intake manifold 17. The intake manifold 17 is branched from the surge tank 13 and connected to each cylinder 11, and communicates with the combustion chamber 32 via an intake port 30 provided in each cylinder 11. Also, the intake manifold 17 is provided with the injector 2
8 is provided, and performs fuel injection toward the intake port 30.

On the other hand, an upstream side of the exhaust passage 18 has an exhaust pipe 38, and the exhaust port 4 of each cylinder 11
It is in communication with the combustion chamber 32 through 0. A muffler 3 attached to a rear portion (not shown) of the vehicle body is located downstream of the exhaust passage 18.
6 is connected. A catalyst 39 such as a three-way catalyst is interposed downstream of the exhaust pipe 38, and an O2 sensor 55 for detecting the air-fuel ratio by detecting the oxygen concentration in the exhaust gas is provided upstream of the catalyst 39. Have been.

The intake port 30 is provided with an intake valve 34 which can be opened and closed at a predetermined timing.
At 0, an exhaust valve 42 is provided which can be opened and closed at a predetermined timing. The intake valve 34 and the exhaust valve 42 are connected to the combustion chamber 32.
The valve opens by moving in a direction protruding from the valve, and closes by moving in a returning direction, and communicates or shuts off between the combustion chamber 32 and the intake port 30 or the exhaust port 40.

The cylinder head 14 has an electromagnetic actuator 44 for each of the intake valve 34 and the exhaust valve 42.
Is provided. The actuator 44 is electrically connected to the O
It is a solenoid type that performs an N-OFF operation, and is energized by a valve operating unit 45 to operate the intake valve 34 and the exhaust valve 4.
2 is driven to open and close.

In addition, as sensors for detecting the operating state of the engine, an air flow meter 24 for detecting an intake air amount Q drawn into the engine 10 and a throttle opening for detecting a throttle opening θ of a throttle valve 26 are provided in the intake passage 16. A degree sensor 54 is provided, and a cylinder angle sensor 50 for detecting the position of the piston 46 (crank rotation angle position) and the engine speed Ne, and a water temperature sensor 52 for detecting the cooling water temperature of the engine 10 are provided in the cylinder section 12. Have been.

Further, an accelerator sensor 51 for detecting an accelerator return amount θb of an accelerator pedal (not shown), a brake stroke sensor 53 for detecting a brake depression amount Sb of a brake pedal (not shown), and a vehicle (not shown) A vehicle speed sensor 57 for detecting the traveling speed is provided. An electronic control unit (hereinafter, simply referred to as "ECU") 56 is provided for inputting detection signals from these sensors and outputting control signals to the control means to control the engine operation.

FIG. 2 is a structural explanatory view showing the internal structure of the ECU 56 shown in FIG. As shown, the ECU 56
Are an input interface 56a for inputting a detection signal from each sensor, an output interface 56b for outputting a control signal to each control means, and a CPU 56 as a main processing unit.
c, a ROM 56d in which a control program and preset fixed data are stored, a RAM 56e in which data obtained by processing signals from the respective sensors and data processed by the CPU 56c are stored, and learning data are stored. The microcomputer is configured as a microcomputer system in which a backup RAM 56f, a timer 56g, and the like are mutually connected by a bus line 56h.

FIG. 3 is a schematic structural explanatory view functionally showing the internal structure of the exhaust valve 42 shown in FIG. 1 and the actuator 44 for driving the same. Since the intake valve 34 has the same structure, a detailed description thereof will be omitted. As shown in the figure, the exhaust valve 42 provided on the cylinder head portion 14 so as to be movable in the up-down direction includes a valve portion 42a and a valve stem portion 42b.

The valve portion 42a is formed in such a shape that it can be in close contact with a valve seat portion 61 provided on the opening peripheral edge 40a of the exhaust port 40 that opens to the cylinder head portion 14 when the exhaust valve 42 is pulled up. ing. A mover 64 made of a magnetic material is connected to the top of the valve stem 42b. The mover 64 is housed in a casing 62 of the actuator 44 provided above the cylinder head 14.

In the casing 62, a valve-opening coil 66 and a valve-closing coil 68 are provided so as to sandwich the mover 64 from above and below, and to allow the mover 64 to move vertically between them. A valve closing spring 7 that constantly urges the exhaust valve 42 in the valve closing direction (upward in the figure) inside the valve opening coil 66 and on the outer periphery of the valve stem portion 42b.
0 is provided.

A valve-opening spring 72 for biasing the exhaust valve 42 in the valve-opening direction (downward in the figure) is provided inside the valve-closing coil 68 on the opposite side of the movable element 64. Is provided. FIG. 3 shows an open state of the exhaust valve 42, in which the valve opening coil 66 is energized and the mover 64 is attracted.

Next, a first embodiment of the present invention will be described below. FIG. 4 is a control block diagram according to the control system of the first embodiment. As illustrated, the control block according to the present embodiment includes a deceleration state detection unit 80,
It comprises an engine operating state detecting section 81, a valve control section 82, and an actuator driving section 83.

The deceleration state detecting section 80 is provided with the accelerator sensor 5
1 and a brake stroke sensor 53. The accelerator sensor 51 determines the amount of return θ of the accelerator pedal.
b, the brake stroke sensor 53 detects the depression amount Sb of the brake pedal. Therefore, the return amount θ
The deceleration operation of the vehicle is detected based on b or the increase in the stepping amount Sb, and the deceleration state of the vehicle is detected and output to the valve control unit 82.

The engine operating state detecting section 81 comprises a crank angle sensor 50, an air flow meter 24, and a throttle opening sensor 54.
e, the intake, compression, explosion, and exhaust strokes of the engine, the intake air amount Q, and the throttle opening θ to detect the valve control unit 8
Output to 2.

The valve control unit 82 includes a deceleration state detection unit 80
When the deceleration operation is detected, the accelerator pedal return amount θ
b or the depression amount Sb of the brake pedal, and the pulse width of the pulse signal is calculated based on the engine speed Ne detected by the engine operation state detection unit 81, and the valve drive unit 4
5 is output. The valve drive unit 45 energizes the actuator 44 based on the input pulse width, and the intake valve 34
Then, the valve opening / closing operation of the exhaust valve 42 is performed.

Next, the operation and effects of the control device for a vehicle engine having the above configuration will be described with reference to FIG. FIG. 5 is a flowchart illustrating an opening / closing control method according to the present embodiment. First, in S101,
The brake depression amount S is determined by the brake stroke sensor 53.
and the accelerator sensor 51 detects the accelerator return amount θb. Here, the deceleration operation of the vehicle is detected.

Next, at S102, the crank angle sensor 5
By 0, the engine speed Ne is detected, and the engine operating state is detected. Then, in S103, the brake depression amount Sb and the engine speed Ne are determined by the RO of the ECU 56.
A determination is made as to whether the value is equal to or greater than a set value preset in M56d.

Here, whether the opening / closing control of the intake valve 34 and the exhaust valve 42 is performed based on the valve opening timing and period during normal vehicle running (hereinafter, simply referred to as normal mode),
Alternatively, it is determined whether the operation is performed based on a valve opening timing and a period during deceleration (hereinafter, simply referred to as a deceleration mode).

Here, if the engine speed Ne and the brake depression amount Sb are equal to or larger than the set values (YES), S1 is performed to perform opening / closing control of the intake / exhaust valves in the deceleration mode.
Move to 04. Also, does not exceed the set value (NO)
In this case, the process proceeds to S105 to perform the opening / closing control of the intake / exhaust valve in the normal mode.

FIG. 6 is an explanatory diagram showing the operating state of the intake valve 34 and the exhaust valve 42 by the above-described vehicle engine control device for each stroke of the engine. (A) in the figure is S1
The operation state of the intake valve 34 and the exhaust valve 42 by the opening / closing control in the normal mode at 05 is shown in FIG.
The operation states of the intake valve 32 and the exhaust valve 42 driven by the opening / closing control in the deceleration mode are shown.

As shown in (a) of the figure, the opening and closing of the intake valve 34 and the exhaust valve 42 are controlled in a predetermined time period t _in and t _ex at normal times.
Then, as shown in (b) in the figure, during the deceleration operation, the intake valve 34 and the exhaust valve 42 are opened for a certain valve-opening period t _in , t
_The valve is opened and closed by a valve opening period t _iin and t _iex shorter than _ex . During the deceleration operation, the intake valve 34 is controlled to open immediately after the start of the intake stroke, and the exhaust valve 42 is controlled to open immediately before the end of the exhaust stroke.

The predetermined valve opening period in the intake stroke and the exhaust stroke is stored in the ROM 56d of the ECU 56 in the valve opening period t.
It is set by referring to a data map set in advance according to iin and tiex.

Therefore, since the intake and exhaust amount of the engine is reduced according to the brake depression amount Sb and the engine speed Ne, the braking force of the vehicle by the engine brake can be adjusted. Further, by controlling the valve opening at the valve opening timing as described above in each stroke of the engine, fuel vaporization and combustion during deceleration are maximized, and the compression period during the exhaust stroke is lengthened. In this case, the engine brake can be set to the best condition.

As a result, the vehicle can be smoothly decelerated according to the driver's intention during deceleration, and drivability can be improved.

Hereinafter, a method of calculating the valve opening times t _iin and t _iex reduced during the deceleration operation will be described. By controlling the opening and closing of the intake and exhaust valves based on the flowchart of FIG.
The intake valve 34 and the exhaust valve 42 are operated during a normal opening period t _in ,
brake depression and t _ex during detection of the deceleration amount Sb and the engine speed the opening period of time of deceleration operation calculated based on the Ne t _iin, are opened and closed controlled by reducing the t _iex.

The valve opening time t _iin of the intake valve 34 is set by the pulse width Pwi of the pulse signal output from the valve control unit 82 to the actuator driving unit 83, and the exhaust valve 4
The valve opening time t _iex of _No. 2 is set by the pulse width Pwe. Then, the pulse widths Pwi and Pwe are calculated by the following equations (1) and (2).

Pwi = G (1−Kb1) / Kb2 (1) Pwe = H × G (1−Kb1) / Kb2 (2) (where 0 <H <1) where G is H is a coefficient dedicated to the exhaust valve 42. Kb1 is a pulse width coefficient set corresponding to the brake depression amount Sb, and Kb2 is a pulse width coefficient set corresponding to the engine speed Ne. FIG. 7 is an explanatory diagram showing the relationship between the brake depression amount Sb and the pulse width coefficient Kb1, and FIG. 8 is an explanatory diagram showing the relationship between the engine speed Ne and the pulse width coefficient Kb2.

Therefore, as shown in FIGS. 7 and 8, when the brake depression amount Sb is large and the engine speed Ne is high, for example, an obstacle is found ahead during high-speed driving, When the operator of the vehicle applies a sudden brake, the pulse widths Pwi and Pwe output to the actuator driving unit 45 are set to be significantly smaller than the pulse widths in the normal state according to the above equations (1) and (2). , Intake valve 34
And the exhaust valve 42 has a greatly shortened valve opening period t.
_{Opening /} closing operation is performed by _iin and _tiex .

As a result, the amount of intake and exhaust of the engine is greatly reduced, and the vehicle is in a state where a strong braking force is applied by the engine brake. Therefore, the braking force of the vehicle can be increased, and the vehicle can be decelerated or stopped according to the operator's intention of the brake operation, and safety can be improved.

When the brake depression amount Sb is small and the engine speed Ne is low, the operator determines that, for example, while traveling on a highway in a cruising state at a constant speed, the vehicle is too close to a vehicle running ahead. When the accelerator pedal is released and the brake is depressed lightly, the pulse widths Pwi and Pw output to the actuator drive unit 45 are reduced.
e is set to a pulse width slightly smaller than the pulse width in the normal state by the above equations (1) and (2). Therefore, the intake valve 34 and the exhaust valve 42 are slightly shortened in the valve opening period t.
_{Opening /} closing operation is performed by _iin and _tiex .

As a result, the intake / exhaust amount of the engine is slightly reduced, and the vehicle is under a state in which a weak braking force is applied by the engine brake, and the vehicle is slightly decelerated according to the intention of the operator to operate the brake. Therefore, smooth deceleration according to the driver's will can be realized during deceleration, and drivability can be improved.

After performing the above control, the process exits the flow of FIG. 5 (return). When the deceleration operation is released,
That is, when the depression of the brake pedal is stopped and the pedal is completely released, or when the accelerator pedal is depressed, this routine is immediately canceled, and the opening / closing control based on the normal valve opening period is performed. Also, when the engine speed Ne drops below a certain value, this routine is automatically canceled and stopped.

The present embodiment is not limited to the above configuration. For example, when the pulse widths Pwi and Pwe are set, the same operation and operation can be performed by using the accelerator return amount θb instead of the brake depression amount Sb. The operation and effect can be obtained. The same _applies to the _{case where} the valve opening periods t _iin and t _iex are calculated based on the accelerator return amount θb and the engine speed Ne.

Next, a second embodiment will be described below. What is characteristic in the present embodiment is that the above-described control for shortening the valve opening period is performed as time elapses after detecting the deceleration operation.

That is, in the first embodiment, when a deceleration operation is detected, the pulse widths Pwi and Pwe are immediately calculated based on the brake depression amount Sb and the engine speed Ne at the time of detection, and these pulse widths are calculated. opening period t _iin set by, but opening and closing control by the deceleration mode to the deceleration operation by t _iex is released is performed, in the present embodiment, deceleration valve opening period t _in, t _ex in the normal Is controlled so as to be gradually shortened in accordance with the elapsed time Tg after the detection of.

As a result, the braking force in the initial stage of deceleration is reduced, the deceleration shock due to the control for shortening the valve opening period is eliminated, and the vehicle can be smoothly braked. Can be eliminated.

Hereinafter, the intake valve 34 of this embodiment will be described.
A method for setting the valve opening periods t _iin and t _iex of the exhaust valve 42 will be described. The pulse widths Pwii and Pwix are calculated by the following equations (3) to (5).

Pwii = D × G (1-Kb1) / Kb2 (3) Pwix = D × H × G (1-Kb1) / Kb2 (4) D = exp (−Tg / B)... (5) Here, D is a valve opening time coefficient, and B is a deceleration request level parameter. Deceleration request level parameter B
Can be determined, for example, from the force of depressing the brake pedal, the speed of depressing the brake, or the accelerator opening speed of depressing the accelerator pedal. Further, the valve opening time coefficient D is calculated by a function of the deceleration request level parameter B and the elapsed time Tg. FIG. 9 is a characteristic diagram showing a relationship between the valve opening time coefficient D and the elapsed time Tg.

Therefore, when the elapsed time Tg is short,
As shown in FIG. 9, the valve opening time coefficient D takes a large value, so that the pulse widths Pwii and Pwix are as described in (3) above.
A smaller value is set in the expression (4), and the intake valve 34 and the exhaust valve 42 perform opening and closing operations during the valve opening periods t _iin and t _iex which are set slightly shorter than the normal times.

Accordingly, the amount of intake and exhaust of the engine is slightly reduced, and the vehicle is in a state where a weak braking force is applied by the engine brake. When the elapsed time Tg becomes longer, the valve opening time coefficient D takes a smaller value, so that the pulse widths Pwii and Pwix become the above (3) and (4).
A larger value is set in the equation, and the intake valve 34 and the exhaust valve 4
2 is a valve opening period t that is set to be significantly shorter than the normal time.
_{Opening /} closing operation is performed by _iin and _tiex .

Therefore, as the time of the deceleration operation becomes longer, the intake and exhaust amount of the engine is greatly reduced, and the vehicle is in a state where a stronger braking force is applied by the engine brake. This reduces the initial braking force during deceleration, gradually increases the braking force over time,
The initial shock due to the control for shortening the valve opening period can be eliminated, the vehicle can be decelerated smoothly and safely, and the braking distance can be shortened.

Next, a third embodiment will be described below. A feature of the present embodiment is that a vehicle including the control device according to the second embodiment includes an automatic transmission (hereinafter, simply referred to as “AT”) as a driving device, and opens and closes the AT in a deceleration mode. Simultaneously with the control, the output shaft of the engine 10 and the input shaft of the AT are controlled to be directly connected (lock-up state).

In the following, the configuration and operation and effect of the apparatus according to the present embodiment will be described. The same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 10 is a control block diagram of a control system according to the third embodiment. As shown, in the present embodiment, in addition to the first and second embodiments, a lock-up instruction unit 85, an AT control unit 86, and a lock-up solenoid 87 are provided.

The AT control unit 86 controls an AT (not shown) having a mechanism (hereinafter, simply referred to as a lock-up mechanism) capable of directly connecting and releasing the output shaft of the engine and the input shaft of the AT, and locks up. The instruction unit 85 outputs a lock-up instruction signal for operating the lock-up mechanism to the AT control unit 86. Also, lock-up solenoid 8
Reference numeral 7 drives the lock-up mechanism according to a control signal from the AT control unit 86.

The vehicle speed v measured by the vehicle speed sensor 57 and the AT
Neutral switch 5 for detecting the neutral state of
8 and a lockup state signal k indicating the state of the lockup mechanism from the lockup detection sensor 59. And the AT control unit 86
Outputs a control signal to a lock-up solenoid 87 that drives a lock-up mechanism.

Therefore, when the deceleration operation of the vehicle is detected, the AT is controlled to a lock-up state, that is, a state directly connected to the output shaft of the engine by the lock-up mechanism almost simultaneously with the opening / closing control in the deceleration mode. As a result, the braking force generated by the opening / closing control in the deceleration mode can be directly transmitted to the drive wheels, and the engine brake of the AT vehicle can be improved. Therefore, the braking distance of the vehicle can be further reduced.

Next, a fourth embodiment will be described below. What is characteristic in the present embodiment is that the vehicle including the control device in the first and second embodiments has two types of drive systems, four-wheel drive and two-wheel drive. It has a drive system switching mechanism that automatically switches according to the driving state of the vehicle, and when it detects a deceleration operation, performs control to forcibly switch the drive system to the four-wheel drive system at the same time as opening and closing control in the deceleration mode. is there.

Hereinafter, the configuration and operation and effect of the apparatus according to the present embodiment will be described. The same components as those in the first to third embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 11 is a control block diagram according to a control system of the fourth embodiment. As shown, in the present embodiment, in addition to the first and second embodiments, a four-wheel drive instructing unit 88, a drive system switching control unit 89, and a switching solenoid 90 are provided.

The drive system switching control unit 89 performs control to switch the drive system between a four-wheel drive system and a two-wheel drive system in accordance with the driving state of the vehicle. A four-wheel drive instruction signal is output. Further, the switching solenoid 90 forcibly switches the driving method to the four-wheel driving method according to a control signal from the driving method switching control unit 89.

The driving system switching control unit 89 has a vehicle running speed v measured by the vehicle speed sensor 57.
, A neutral signal c from a neutral switch 58 for detecting the neutral state of the AT, and a drive state signal d indicating the current drive state of the drive from the drive state detection sensor 60. And the drive system control unit 8
Reference numeral 9 outputs a control signal to a switching solenoid 90 for switching between a two-wheel / four-wheel drive system. Then, when the deceleration operation of the vehicle is detected, almost simultaneously with the opening / closing control in the deceleration mode,
The drive system is switched to the four-wheel drive system by the drive system switching mechanism.

Therefore, the engine brake generated by the opening / closing control in the deceleration mode can be distributed to all the drive wheels, so that the braking force can be transmitted to the road surface in a well-balanced manner. This can reduce tire slip and the like, so that the braking distance of the vehicle can be reduced with a stronger braking force.

Next, a fifth embodiment will be described below. What is characteristic in the present embodiment is that a vehicle including the control device according to the first and second embodiments has a forward monitoring mechanism that monitors the front in a running state,
Automatic mechanical brake (operated brake)
When the forward monitoring mechanism recognizes a danger element based on a preset condition, the automatic braking mechanism is controlled together with the opening / closing control in the deceleration mode.

Hereinafter, the configuration and operation and effect of the apparatus according to the present embodiment will be described. The same components as those in the first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 12 is a control block diagram relating to a control system according to the fifth embodiment. As shown, in the present embodiment, in addition to the first and second embodiments, a forward monitoring unit 91, a control signal output unit 92, an automatic brake control unit 93, and a brake drive solenoid 94 are provided. .

The forward monitoring unit 91 includes an external monitoring sensor 91
a, an image processing unit 91b, the external monitoring sensor 91a is configured by, for example, a CCD camera, and the image processing unit 91b is configured by, for example, a microcomputer. Then, the image processing data obtained by converting the image information from the CCD camera is output from the forward monitoring unit 91 and is input to the control signal output unit 92.

The control signal output unit 92 is constituted by a computer, and converts the input image processing data into the ECU 5
And outputs the result of the comparison to the valve control unit 82 and the automatic brake control unit 93. Here, the conditions to be compared are for determining a risk factor.

The automatic brake control unit 93 is provided with the vehicle speed sensor 5
7, a wheel rotation speed detection sensor 47 for detecting the rotation speed Nw of the wheel (not shown), a detection signal from each sensor of the brake sensor 48 for detecting the operation state of the brake device 95, and a signal from the control signal output unit 92. A brake solenoid 9 that inputs a control signal and drives a brake device 95
4 to output a control signal.

Therefore, when a dangerous element is recognized ahead of the vehicle by the forward monitoring unit 91, a control signal is output to the valve control unit 82 and the automatic brake control unit 93 by the control signal output unit 92.

When the control signal of the control signal output unit 92 is input, the valve control section 82 determines that the vehicle needs to perform a deceleration operation, and performs opening / closing control in a deceleration mode. The automatic brake control unit 93 inputs the vehicle speed v, the wheel rotation speed Nw, and the operation state of the brake device 95 as data, and controls the brake device 95 based on the data so that an optimum braking force can be applied.

Therefore, the vehicle can be prevented from colliding by performing the braking of the vehicle by the two controls at the initial stage when the dangerous element is found, and the vehicle is safely decelerated or stopped by avoiding the dangerous element. be able to.

Further, in combination with the opening / closing control (shortening control) in the deceleration mode described in the second embodiment, the signal from the forward monitoring unit 91 is processed, and the time is determined according to the distance from a dangerous element, for example, an obstacle. As control is performed over time, a stronger braking force and a wider braking force control width can be secured.
The deceleration can be set arbitrarily.

The present invention is not limited to the configurations of the above embodiments, and various modifications can be made within the scope of the invention. For example, in each of the above embodiments, a case where the present invention is applied to a horizontally opposed engine is illustrated. However, the present invention is not limited to this, and it is needless to say that the present invention can be applied to other engines. It is also possible to provide all of the forms.

[0087]

As described above, according to the vehicle engine control apparatus of the present invention, when the deceleration operation of the vehicle is detected, the opening period of at least one of the intake valve and the exhaust valve is reduced. By shortening according to the deceleration state,
The vehicle can be smoothly decelerated, the drivability can be improved, and the braking distance can be reduced by a stronger braking force.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an automobile engine to which a vehicle engine control device according to the present invention is applied.

FIG. 2 is a configuration explanatory diagram showing an internal configuration of an ECU shown in FIG. 1;

FIG. 3 is a schematic structural explanatory view functionally showing an internal structure of an exhaust valve shown in FIG. 1 and an actuator for driving the exhaust valve.

FIG. 4 is a control block diagram according to a control system of the first embodiment.

FIG. 5 is a flowchart illustrating an opening / closing control method according to the present embodiment.

FIG. 6 is an explanatory diagram showing the behavior of an intake valve and an exhaust valve for each stroke of the engine.

FIG. 7 is an explanatory diagram showing a relationship between a brake depression amount Sb and a pulse width coefficient Kb1.

FIG. 8 is an explanatory diagram showing a relationship between an engine speed Ne and a pulse width coefficient Kb2.

FIG. 9 is a characteristic diagram showing a relationship between a valve opening time coefficient D and an elapsed time Tg.

FIG. 10 is a control block diagram according to a control system of a third embodiment.

FIG. 11 is a control block diagram according to a control system of a fourth embodiment.

FIG. 12 is a control block diagram according to a control system of a fifth embodiment.

[Explanation of symbols]

10 Engine Body 34 Intake Valve 42 Exhaust Valve 44 Actuator 45 Actuator Drive Unit 50 Crank Angle Sensor (Engine Operating State Detecting Means) 51 Accelerator Sensor 53 Brake Stroke Sensor (Decelerating State Detecting Means) 82 Valve Control Unit (Valve Control Means) t _in normal opening period at the time of normal operation of the valve opening period t _ex exhaust valve of the intake valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/12 320 F02D 41/12 320 45/00 312 45/00 312F

Claims (9)

[Claims] 1. A control device for a vehicle engine having an electromagnetic intake / exhaust valve control system for electrically automatically opening and closing intake / exhaust valves of a vehicle engine, wherein the vehicle is decelerated while the vehicle is running. A deceleration state detecting means for detecting a deceleration state when detecting a deceleration operation for detecting an operation state of the engine; a deceleration state and an engine operation state when detecting the deceleration operation And a valve control unit for performing control to shorten at least one of the intake / exhaust valve opening periods from a normal valve opening period. 2. The deceleration condition detecting means detects the deceleration operation by detecting a depression operation of a brake pedal, and detects the deceleration condition based on an amount of depression of the brake pedal. Item 2. A control device for a vehicle engine according to item 1. 3. The deceleration state detection means detects the deceleration operation by detecting a return operation of an accelerator pedal, and detects the deceleration state based on a return amount of the accelerator pedal. Item 3. The control device for a vehicle engine according to item 1 or 2. 4. The valve control means, when detecting the deceleration state, shortens an opening period of the intake valve in an intake stroke of the engine in accordance with the deceleration state and an engine operating state, and The control device for a vehicle engine according to any one of claims 1 to 3, wherein the valve opening timing is controlled so as to be immediately after the start of the intake stroke. 5. The valve control means, when detecting the deceleration state, shortens an opening period of the exhaust valve in an exhaust stroke of the engine according to the deceleration state and an engine operating state, and The control device for a vehicle engine according to any one of claims 1 to 4, wherein the valve opening timing is controlled to be immediately before the end of the exhaust stroke. 6. The valve control device according to claim 1, wherein the valve control means performs opening / closing control so as to shorten the valve opening period in accordance with the elapse of time after detecting the deceleration operation. Control system for vehicle engine. 7. The vehicle according to claim 1, wherein the vehicle has an automatic transmission, the automatic transmission has a lockup mechanism, and performs the lockup when detecting the deceleration operation. Engine control device. 8. The vehicle has two types of drive systems, two-wheel drive and four-wheel drive, and has an automatic switching mechanism that automatically switches between these drive systems according to the driving state of the vehicle. 8. The control device according to claim 1, wherein the automatic switching mechanism forcibly switches the driving system of the vehicle to four-wheel drive when the deceleration operation is detected. 9. A control device for a vehicle engine having an electromagnetic intake / exhaust valve control system for electrically automatically opening / closing an intake / exhaust valve of a vehicle engine, wherein a front of the vehicle is monitored in a running state. A monitoring mechanism, a danger element determining means for determining the presence or absence of a forward danger element by the forward monitoring mechanism, and when the danger determination means determines that there is a danger element,
Vehicle condition detecting means for detecting the distance to the dangerous element and the driving state of the vehicle; valve control for performing control to shorten at least one of the intake and exhaust valve opening periods in accordance with the detected vehicle condition And a control unit for a vehicle engine.