JPH0617674A - Control device for engine - Google Patents

Abstract

PURPOSE:To improve the traveling stability of a vehicle by prohibiting the switching of the torque assist state increasing the generated torque of an engine when adjusting the generated torque of the engine for the traction control so that the slip value of a driving wheel becomes the objective. CONSTITUTION:An engine control unit 81 controls three-way valves 75, 76 respectively based on various detection signals from various sensors 78-80 detecting the operation state of an engine 2. The negative pressure of a vacuum chamber 72 is guided into actuators 68, 69, and intake selector valves VA, VB are opened or closed respectively. The length of the intake path including the intake pipes 61a, 61b of the engine 2 is changed, and the torque assist state increasing the generated torque of the engine 2 is switched. The switching of the torque assist state is prohibited during the traction control. The vehicle control taken with a serious view of the traveling stability is attained during the traction control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device having a traction control function and torque assist means.

[0002]

2. Description of the Related Art Recently, when the vehicle starts on a slippery road surface, accelerates, or corners, the slip ratio of the drive wheels to the road surface is prevented from becoming excessive (idling state) to improve the startability and acceleration. Various types of so-called traction control devices have been proposed that are capable of satisfying the characteristics and vehicle stability during cornering.

The above-mentioned traction control is basically performed by reducing the torque (traction) applied to the drive wheels, and therefore engine control (fuel cut, retard of ignition timing) or the like for reducing the torque (output) generated by the engine. Is performed. In both cases of this engine control, feedback control is generally performed so that the actual slip value of the drive wheels on the road surface becomes a predetermined target value.

A conventional example of such a traction control device is disclosed in, for example, Japanese Patent Publication No. 58-20051.

On the other hand, in recent engines, there is a strong demand for higher output, and in particular, it is desired to improve intake charging efficiency and obtain high torque in the entire operating region of the engine.

In order to meet such demands, a variable intake inertia supercharging means disclosed in Japanese Utility Model Publication No. 60-8117 and a variable intake resonance supercharging means disclosed in Japanese Utility Model Laid-Open No. 1-159126 are conventionally used. A variable intake type torque assist system having the above has been proposed.

In such a variable intake type torque assist system, generally, the intake pipe negative pressure of the engine is used as a power source, and the intake switching valve is switched by the intake pipe negative pressure to set the intake pipe capacity and intake pipe length to a predetermined value of the engine. The setting is controlled so that it becomes the best for each operating area.

The switching of the intake switching valve is performed by an engine control unit composed of, for example, a microcomputer, and the engine speed Ne is changed.
Further, the throttle opening TVO is sequentially monitored, and this is executed by ON / OFF controlling an electromagnetic opening / closing valve provided midway in the negative pressure introducing passage from the engine intake system to the intake switching valve.

[0009]

However, in the case of the torque assist system as described above, the intake switching valve cannot be operated when there is no intake pipe negative pressure as a power source such as when the throttle is fully opened. There is no choice but to adopt a method of providing a negative pressure chamber for storing negative pressure in the middle of the negative pressure introducing passage and realizing the switching force by the negative pressure component stored in the negative pressure chamber.

As a result, for example, when shifting up from the time of starting acceleration of the vehicle, there occurs a case where the desired switching cannot be performed if the set rotational speed for switching the intake air is high.

On the other hand, considering the combination of the torque assisting means and the above-mentioned traction control means, the following problems will occur.

That is, the state in which the engine output is reduced by the traction control is basically when the wheel is idling, and the output is equal to or higher than the engine speed required for the vehicle to run. Originally, the switching (operation) of the torque assisting means for the purpose of improving the output is unnecessary. Rather, in that case, it is better to intentionally switch to the output lower side and reduce the retard of the ignition advance and the fuel cut region (number of cylinders and time) to reduce the burden on the engine body (exhaust temperature and catalyst temperature). You can also think that you can reduce it. Moreover, the negative pressure in the negative pressure chamber is only consumed each time the switching point of the output improving means is passed due to an unnecessary change in the engine speed, and as a result, the engine torque after the operation of the traction control means is stopped. There is a problem in that the output performance is deteriorated due to the decrease of the engine and the commercialability of the engine itself is impaired.

[0013]

The invention described in each of claims 1 to 4 of the present application has been made for the purpose of solving the above problems. For example, when the traction control means is operated, the intake air Each of them has the basic feature of prohibiting the switching operation of the torque assisting means using a negative pressure as a drive source, and is configured as follows.

(1) Structure of the Invention According to Claim 1 The engine control device according to the invention described in claim 1 is a traction adjusting means for adjusting the torque generated by the engine, and a slip for detecting the slip value of the drive wheels with respect to the road surface. Detection means, traction control means for controlling the traction adjustment means so that the slip value detected by the slip detection means becomes a predetermined target value, torque assist means for increasing the torque generated by the engine, and the engine In a vehicle having a torque assist state switching means for switching the torque assist state of the torque assist means in accordance with the operating region of the above, the switching operation of the torque assist state switching means is prohibited when the traction control means is operating. It is characterized in that a switching prohibition means is provided.

(2) Configuration of the invention according to claim 2 The engine control device according to the invention according to claim 2 is the control device according to claim 1.
The configuration of the invention described above is characterized in that even if the operation of the traction control means is stopped, the switching prohibition operation of the switching prohibition means is maintained within a predetermined period after the stop.

(3) Structure of the invention according to claim 3 In the engine control device according to claim 3 of the present invention, in the structure of the invention according to claim 1 or 2, the traction adjusting means is a combustion state of the engine. Is a torque adjusting means for adjusting the engine torque by changing the engine torque, and the torque assisting means includes an intake pipe length variable valve for switching the intake pipe length of the engine, a negative pressure actuator for operating the intake pipe length variable valve, and an engine intake An intake resonance supercharging means comprising: a negative pressure chamber for introducing a negative pressure of the system and supplying the negative pressure to the negative pressure actuator.

(4) Structure of the invention according to claim 4 In the engine control device according to claim 4 of the present invention, in the structure of the invention according to claim 1 or 2, the traction adjusting means is a combustion state of the engine. Is a torque adjusting means for adjusting the engine torque by varying the engine torque. The torque assisting means comprises an intake capacity variable valve for switching the intake capacity of the engine, a negative pressure actuator for operating the intake capacity variable valve, and an engine intake It is an intake inertia supercharging means provided with a negative pressure chamber for introducing a negative pressure of the system and supplying the negative pressure to the negative pressure actuator.

[0018]

The engine control device according to the first to fourth aspects of the present invention is configured as described above.
Corresponding to the respective configurations, the following effects are achieved.

(1) Operation of the invention of claim 1 In the engine control device of the invention of claim 1, first, the rotation speed of each wheel of the automobile is read, and the slip of the vehicle itself or the wheel's slippage is detected by the difference in each rotation. Engines are detected by detecting the spin etc. and reducing the engine output according to the rotation difference, and by changing the actuator mainly for improving the engine output and changing the intake system pipe length, capacity, etc. It has both control functions of torque assist control that keeps the output always high,
Achieves high vehicle running performance with high running stability and good output performance.

Moreover, a prohibition system for prohibiting the switching of the torque assisting means when the traction control means is activated is added to the basic control system to ensure the effectiveness of the traction control effect. ing.

(2) Operation of the invention according to claim 2 In the configuration of the engine control device of the invention according to claim 2,
In the configuration of the invention described in claim 1, even if the operation of the traction control means is stopped, the switching prohibiting operation of the switching prohibiting means is maintained as it is for a predetermined period after the operation is stopped.

Therefore, even if the operation of the traction control means is once stopped, for example, in the case of a road surface condition where slip is likely to occur, the engine output is immediately increased by the operation of the torque assist means, and slip occurs again. Therefore, it is possible to prevent the occurrence of the hunting state of the traction control.

(3) Operation of the invention according to claim 3 In the configuration of the engine control device of the invention according to claim 3,
In the structure of the invention according to claim 1 or 2, the traction adjusting means is composed of a torque adjusting means for adjusting the engine torque by varying the combustion state of the engine, and the torque assisting means is An intake pipe length variable valve that switches the intake pipe length of the engine, a negative pressure actuator that operates the intake pipe length variable valve, and a negative pressure chamber that introduces a negative pressure of an engine intake system and supplies the introduced negative pressure to the negative pressure actuator. And an intake resonance supercharging means including.

Therefore, in the control device for the engine, similarly to the above, first, the rotation speed of each wheel of the automobile is read, the slip of the vehicle itself, the spin of the wheel, etc. are detected from the rotation difference of each, and the engine is detected according to the rotation difference. The engine output is always maintained at a high level by changing the intake system pipe length by switching the traction control control that reduces the output of the engine and the actuator that uses the intake negative pressure as the power source, mainly for improving the engine output. It has both control functions of torque assist control and realizes vehicle running performance with high running stability and good output performance.

Moreover, a prohibition system for prohibiting the switching of the torque assisting means when the traction control means is in operation is added to the basic control system, thereby ensuring the effectiveness of the traction control. The reduction of the negative pressure in the negative pressure chamber is prevented, and the output improving action of the torque assist means after the operation of the traction control means is stopped is ensured.

(4) Operation of the invention according to claim 4 In the engine control device according to claim 4, in the configuration of the invention according to claim 1 or 2, the traction adjusting means changes the combustion state of the engine. The torque assisting means adjusts the engine torque by adjusting the intake torque of the engine, and the torque assisting means changes the intake capacity of the engine by an intake capacity variable valve and a negative pressure actuator that operates the intake capacity variable valve. ,
The intake inertia supercharging means is provided with a negative pressure chamber for introducing a negative pressure of the engine intake system and supplying the introduced negative pressure to a negative pressure actuator.

That is, in the engine control device, similarly to the above, first, the rotation speed of each wheel of the automobile is read, the slip of the vehicle itself, the spin of the wheel, etc. are detected from the respective rotation differences, and the engine is detected according to the rotation difference. The traction control control that reduces the output of the engine and the actuator that uses the intake negative pressure as the power source mainly for improving the output of the engine are switched, and the engine output is always maintained at a high state by changing the capacity of the intake system. It has both control functions of torque assist control and realizes vehicle running performance with high running stability and good output performance.

Moreover, a prohibition system for prohibiting the switching of the torque assisting means when the traction control means is activated is added to the basic control system, thereby ensuring the effectiveness of the traction control. The reduction of the negative pressure in the negative pressure chamber is prevented, and the output improving action of the torque assist means after the operation of the traction control means is stopped is ensured.

[0029]

Therefore, first, according to the engine control device of the invention of claim 1, the engine output is originally
During traction control in which (torque) is reduced to prioritize traveling stability, the action of the torque assisting means for increasing the engine output is reliably released, and vehicle control with emphasis on traveling stability is realized.

According to the engine control apparatus of the second aspect of the present invention, when the effect of the first aspect of the invention is realized, the torque assist inhibition effect is maintained for a predetermined period even after the traction control is completed. Therefore, on a slippery road surface or the like, the torque suddenly rises immediately after the traction control is finished, slipping occurs again, and discomfort such as repeated traction control is eliminated.

Further, according to the engine control device of the present invention, the intake resonance supercharging means and the intake inertia supercharging means are used as the torque assisting means, in addition to the same effects as the above. In this case, the effect of preventing a decrease in intake negative pressure in the negative pressure chamber for operating each actuator is enhanced. As a result, the torque improving action after the end of the traction control can be ensured.

[0032]

2 to 9 show the configuration and operation of each part of an engine control apparatus according to an embodiment of the present invention, which has both traction and torque assist control means.

First, FIGS. 2 and 3 show the construction of a traction control device portion having both means for adjusting engine torque and braking force of the same apparatus. In FIG. 2, 1FL is the left front wheel, 1FR is the right front wheel, 1R
L is the left rear wheel, and 1RR is the right rear wheel. A V-type 6-cylinder engine 2 equipped with a variable intake resonance supercharging means, which will be described later, as a torque assisting means is laterally mounted on the front portion of the vehicle body. The torque generated by the engine 2 is the clutch 3 and the transmission 4. After being transmitted to the differential gear 5, they are transmitted to the left front wheel 1FL via the left drive shaft 6L and to the right front wheel 1FR via the right drive shaft 6R. As described above, the vehicle in this embodiment is a front-wheel drive vehicle in which the front wheels 1FL and 1FR are the driving wheels and the rear wheels 1RL and 1RR are the driven wheels.

Then, the brakes 7F equipped on each wheel
R to 7RR are hydraulic disc brakes. Further, the master cylinder 8 as a brake fluid pressure generation source is a tandem type having two discharge ports 8a and 8b. The brake pipe 13 extending from one discharge port 8a of the master cylinder 8 is branched into two in the middle,
One branch pipe 13F is the front left wheel brake 7FL.
(Wheel cylinder mounted in the caliper) is connected to the other branch pipe 13R and the rear right wheel brake 7R
It is connected to R. The branch pipe 14 is also branched into two from the other discharge port 8b of the master cylinder 8, one branch pipe 14F is connected to the right front wheel brake 7FR, and the other branch pipe 14R is the left rear wheel brake 7RL.
Connected to each.

Branch pipe 13 for front wheels, that is, for drive wheels
Electromagnetic hydraulic pressure adjusting valve 15L or 1 for F and 14F
5R is connected, and an electromagnetic opening / closing valve 16L or 16R is connected to the branch pipes 13R, 14R for the rear wheels. The hydraulic pressure adjusting valves 15L and 15R are used for the brakes 7FL and 7L.
Brake fluid pressure from the master cylinder 8 to FR,
Brake fluid pressure for the brakes 7FL, 7FR is pipe 21L, 2
The mode of opening to the reservoir tanks 22L and 22R via 1R is switched. The brake fluid in the reservoir tank 21L is returned to the pipe 13 by the pump 23L via the pipe 25L to which the check valve 24L is connected. Similarly, the brake fluid in the reservoir tank 21R is pumped by the pump 23R to the check valve 24R. Is returned to the pipe 14 via the pipe 25R connected to.

The stepping force on the brake pedal 12 is
It is transmitted to the master cylinder 8 via a booster or brake booster 11. This booster 11 is basically the same as a known vacuum booster, but during traction control, as will be described later, it performs a boosting action even if the brake pedal is not depressed. Is configured.

As shown in detail in FIG. 3, the booster 11 has a case 31 fixed to the vehicle body and the master cylinder 8, and the inside of the case 31 includes a diaphragm 32 and a valve body 33 fixed to the diaphragm 32. Is defined by a first chamber 34 and a second chamber 35. Negative pressure (for example, intake negative pressure of the engine 2) is always supplied to the first chamber 34, and when the brake pedal is not depressed, the second chamber 35 communicates with the first chamber 34 and the booster 11 Is deactivated. Then, when the brake pedal 12 is depressed, atmospheric pressure is supplied to the second chamber 35, whereby the diaphragm 32 is displaced forward together with the valve body 33, and a boosting action is performed.

The switching between the negative pressure supply and the atmospheric pressure supply to the second chamber 35 is basically performed by the valve device mounted inside the valve body 33. This valve body 33
The part will be described with reference to FIG.

First, the valve body 33 has a power piston 41 fixed to a diaphragm, and a reaction disc 42 and a base end portion of the output shaft 43 are fitted in a recess 41a formed in the power piston 41. Have been combined. The output shaft 43 serves as an input shaft of the master cylinder 8. A valve plunger 45 is attached to the tip of the input shaft 44 connected to the brake pedal 12 inside the valve body 33. A vacuum valve 46 is arranged behind the valve plunger 45.

The power piston 41 has a pressure introducing passage 50.
The pressure introducing passage 50 is always communicated with the space X formed around the valve plunger 45. This space X is always communicated with the second chamber 35. A valve seat 47, on which the vacuum valve 46 is seated, is formed at the end of the pressure introducing passage 50 that opens toward the space X. In addition, the vacuum valve 46 is a valve plunger 45.
The valve seat 45a formed at the rear end is also seated on and off.

In the above structure, it is assumed that a negative pressure is being introduced into the pressure introducing passage 50. In this state, when the brake pedal 12 is not depressed, in the state of FIG. 3, the vacuum valve 46 is seated on the valve seat 45a by the urging force of the springs 48 and 49, but is separated from the valve seat 47. There is. Therefore, the pressure introducing passage 5
The negative pressure from 0 is introduced into the second chamber 35 through the space X, and the boosting action is not performed.

When the brake pedal 12 is depressed,
The input shaft 44 and therefore the valve plunger 45 move forward.
(Moved to the left in the figure). During this forward movement, the vacuum valve 46
First, the valve seat 47 is seated to block the communication between the space X and the pressure introducing passage 50, and then the valve seat 45a is separated from the vacuum valve 46. By separating the vacuum valve 46 and the valve seat 45a, the atmospheric pressure from the rear of the valve body 33 is introduced into the space X, and the second chamber 35 becomes the atmospheric pressure. As a result, the diaphragm 32 is displaced forward together with the valve body 33, and as a result, the output shaft 43 moves forward and a boosting action is performed. The brake reaction force from the master cylinder 8 is transmitted via the reaction disc 42 to the valve plunger 4
5, and thus transmitted to the brake pedal 12. When the depression operation force of the brake pedal 12 is released, the return spring 36 (see FIG. 2) returns to the state of FIG. 3 to prepare for the next boosting action.

The part described above is the same as the known vacuum booster, but in this embodiment, the negative pressure of the first chamber 34 is introduced into the pressure introducing passage 50 for slip control. The state is switched to the state where the atmospheric pressure is introduced. That is, the first chamber 34 and the pressure introducing passage 5
0 is connected via a pipe 37, and a three-way electromagnetic switching valve 38 (see FIG. 2) is connected to the pipe 37. The switching valve 38 communicates the pressure introducing passage 50 with the first chamber 34 during demagnetization, and introduces atmospheric pressure into the pressure introducing passage 50 during excitation. When the switching valve 38 is excited and atmospheric pressure is introduced into the pressure introducing passage 50, the space X, and thus the second chamber 35.
Becomes atmospheric pressure even when the brake pedal 12 is not depressed, and as a result, a boosting action is performed to generate brake fluid pressure in the master cylinder 8.

Next, FIG. 4 schematically shows the control system. In the figure, UTR is a traction control unit constructed by using a microcomputer. ON / OFF signals from sensors or switches S1 to S9 are input to the traction control unit UTR. The sensors S1 to S4 detect the rotation speeds of the wheels 1FL to 1RR. The switch S5 is an accelerator switch that is turned on when the accelerator pedal 10 is fully closed. The switches S6 and S7 are respectively operated when the brake pedal 12 is depressed, and for example, one switch is a normally open type and the other is a normally closed type. The sensor S8 detects the accelerator opening. The sensor S9 detects the steering angle of the steering wheel.

Further, as shown in FIG. 4, the traction control unit UTR outputs a control signal to each device. Reference numeral 9 in the control signal is torque adjusting means for adjusting the torque generated by the engine 2. is there. The torque adjusting means 9 adjusts the torque generated by the engine, for example, by adjusting the intake air amount, or by combining the number of each fuel cut cylinder and the ignition timing adjustment.

That is, the control unit UTR has, in addition to the brake control system described above, an input interface for receiving signals from the sensor switches and a CPU.
And a microcomputer comprising a ROM and a RAM,
An output interface and a drive circuit for driving the igniter and the fuel injection device are provided. The ROM is provided with a control program necessary for slip control, various maps or tables, and the RAM is used to execute the control. Various memories required for the operation are provided. And
The central control unit includes a slip determination threshold value setting unit, a slip amount calculating unit, a slip determining unit, a control target value setting unit, a control level calculating unit, and a torque adjusting unit for the engine, which will be described later. It is provided with control means and the like.

The limit of the fuel injection amount is based on the control level FC determined by adding the previous value and the initial value in consideration of the deviation of the average slip amount from the control target amount and the change rate of the deviation. This is performed by selecting the next fuel cut table pattern (the pattern having a higher numerical value is selected as the control level FC becomes higher). In this case, a fuel cut prohibition condition is set for each control level FC so that the fuel cut is limited in a region where the engine speed is low.

Regarding the ignition timing, the retard amount is determined according to the control level and is output. In this case, the maximum retard amount is limited in the region where the engine speed is high.

Next, FIG. 5 shows the construction of the torque assist control unit of the engine in the above embodiment. In the engine 2, the first (No1) to the sixth (No6) six cylinders are the first and second cylinder groups 2a, 2 whose operation order is not continuous.
The above-mentioned V-type 6-cylinder engine is configured by grouping into b and arranging both cylinder groups 2a and 2b so as to face each other in a V shape.

The engine 2 is provided with first and second surge tanks 60a, 60b extending in the cylinder arrangement direction above the first and second cylinder groups 2a, 2b. The tanks 60a and 60b are connected to each cylinder by an intake manifold (not shown), and the surge tanks 60a and 60b are connected to one ends of intake pipes 61a and 61b, respectively.

The upstream sides of the intake pipes 61a and 61b are assembled and connected to a throttle body 62, and inside the throttle body 62, a throttle valve 63 which is opened and closed by depressing an accelerator pedal is arranged. An intake pipe 64 is connected to the throttle body 62, and an air cleaner 65 is connected to the upstream side of the intake pipe 64.

Between the surge tanks 60a and 60b, a first communication passage 66 having a short dimension is connected substantially at the center in the longitudinal direction, and a second communication passage 67 having a long dimension is connected at one end in the longitudinal direction. The first and second communication passages 66 and 67 are provided with first and second intake switching valves VA and VB for opening and closing them.

Diaphragm type first and second actuators 68, 69 for driving the intake switching valves VA, VB are connected to the rotary shafts of the intake switching valves VA, VB, respectively. The intake switching valves VA and VB are opened by introducing pressure.

A negative pressure introducing passage 70 is connected to the intake pipe collecting portion 61 on the downstream side of the throttle valve 63, and a check valve 71 is provided in the middle of the negative pressure introducing passage 70. The other end of the negative pressure introducing passage 70 has a vacuum chamber.
(Negative pressure chamber) 72 is connected to the vacuum chamber 72 via the negative pressure introducing passage 70.
A negative pressure of 1 is introduced and stored.

One end of a negative pressure supply passage 73 is connected to the vacuum chamber 72, and the negative pressure supply passage 73 is connected to the vacuum chamber 72.
A first negative pressure supply passage 74 is connected in the middle of the
A three-way valve 75, which is an electromagnetic solenoid valve, is interposed in the negative pressure supply passage 74.

One output port of the three-way valve 75 is open to the atmosphere, and the other end of the first negative pressure supply passage 74 is connected to the first actuator 68. And
When the three-way valve 75 receives the control signal and shuts off the output port from the atmosphere, the vacuum chamber 72 is introduced into the negative pressure chamber of the first actuator 68 via the negative pressure supply passages 73 and 74.

The other end of the negative pressure supply passage 73 is connected to a three-way valve 76 which is an electromagnetic solenoid valve, and the three-way valve 7
One output port of 6 is opened to the atmosphere, and the second negative pressure supply passage 77 is connected to the other output port. The other end of the second negative pressure supply passage 77 is connected to the second actuator 69, and when the three-way valve 76 receives a control signal to shut off the output port from the atmosphere, the negative pressure of the vacuum chamber 72 is reduced. Are introduced into the negative pressure chamber of the second actuator 69 via the negative pressure supply passages 73 and 77.

In FIG. 5, reference numeral 78 is a rotation speed sensor for detecting the rotation speed Ne of the engine, and 79 is a throttle valve 6.
3, a throttle sensor for detecting the opening degree of 3, a brake sensor (brake operation detecting means) 80 for detecting the operation of the brake, and a torque 81 for switching control of the intake path length (substantial path length of the intake path). It is an engine control unit for assist.

The engine control unit 81 is
Control signals are input to the first and second three-way valves 75, 76 on the basis of the engine speed Ne and on condition that the traction control is not executed by inputting the signals from the sensors 78 to 80. Is output, the negative pressure of the vacuum chamber 72 is introduced into the first and second actuators 68 and 69, and the intake path length is switched and controlled in the pattern B shown in FIG. 6B. Further, the engine control unit 81 prohibits switching of the intake path length based on the engine speed when the brake is operating and the engine load is equal to or higher than a predetermined value even if the traction control is not performed. Then, the pattern A is controlled by the pattern A shown in FIG.

During normal operation of the engine 2, the intake switching valves VA and VB are controlled to switch in the pattern B shown in FIG. 6 (b) based on the engine speed Ne. That is,
When the engine speed Ne is less than the first set value Ne ₁ which is about the idle speed, the engine control unit 81
Does not output a control signal, the negative pressure is not introduced into the first and second actuators 68, 69, and the intake switching valves VA, V
B is closed.

Next, the engine speed Ne is the first set value Ne.
_When it becomes ₁ or more, a control signal is output from the engine control unit 81 to the three-way valves 75 and 76, and the first and second
The actuators 68, 69 of the intake valve V
A and VB are opened. After that, when the engine speed Ne increases and exceeds the second set value Ne ₂ , the output of the control signal is stopped and the intake switching valves VA, VB are closed.

The engine speed Ne further increases, and the third
When the set value Ne ₃ is exceeded, the control signal is sent to the second three-way valve 76,
If the fourth set value Ne ₄ is exceeded, the first three-way valve 75
The control signals are output and the intake switching valves VA and VB are sequentially opened. Further, when the engine speed Ne exceeds the fifth set value Ne ₅ , the output of the control signal is stopped and the intake switching valves VA, VB are closed.

As described above, during the normal operation of the engine 2, the intake switching valves VA and VB are controlled to be opened / closed in accordance with the engine speed Ne to appropriately adjust the intake passage length.
As shown in (4), the intake resonance supercharging effect is secured in the entire rotation range, and the charging efficiency (torque) is increased.

By the way, the traction control unit UTR executes a control operation as shown in the flowchart of FIG. 7, for example.

That is, first, in step S ₁ , the wheel speeds of the front and rear wheels are read, and in step S ₂ , the rotation difference ΔNw between the front and rear wheels is calculated.

Next, in step S ₃ , it is determined whether the calculated rotation difference ΔNw is greater than or equal to the determination reference value ΔNTR for operating the traction control device described above.

As a result, when YES, the traction control flag FTRC indicating the execution state of traction control is set to FTRC = 1 (execution), and when NO, it is set to FTRC = 0 (non-execution).

[0068] Then, if it is set to FTRC = 1 as traction control execution, first, in step S ₆ in the engine speed Ne, reads each engine load Ce, after having determined the operating region of the engine in step S _7, each determines the ignition timing retard amount and fuel-cut (number) for the engine torque reduction, executes a reduction control of the engine output (torque) at the step S ₈ based on it. As a result, the engine torque is reduced by a predetermined amount, the slip ratio of the drive wheels is reduced, and stable vehicle running characteristics can be maintained.

Next, the engine control unit 8 is linked with the traction control.
The contents of the torque assist control for improving the engine output according to No. 1 will be described in detail with reference to the flowchart of FIG.

That is, first, in step S ₁ , each engine data such as the engine speed Ne and the throttle opening TVO is read.

Next, in step S ₂ , the current engine operating range determined from the engine data is, for example, as shown in FIG.
It is determined whether or not it is the intake switching region shown in the pattern B of (b).

If the result of this judgment is YES, step S
Proceeding to ₃ , the traction control flag FT set in the traction control routine of FIG. 7 above.
It is determined whether the value of RC is 0.

As a result, when YES, the first and second three-way valves 75 and 76 are turned ON (atmosphere side closed) and the vacuum chamber 72 side and the negative pressure actuator 6 are turned on.
8 and 69 are communicated with each other, and the intake switching valves VA and VB are opened by the intake negative pressure of the engine to increase the intake pipe length and enhance the resonance supercharging effect. As a result, the engine torque is improved.

On the other hand, the traction control is performed and the traction control flag FTRC is set when the intake switching region determined to be NO in step S ₂ is not reached or even in the intake switching region determined to be NO in step S _3. When FTRC = 1 is set, the routine proceeds to step S ₅ , where the intake switching valves VA, VB are closed to prohibit the torque assist control.

As a result, as described above, when the engine torque is reduced by the traction control to ensure the running stability of the vehicle, the action of increasing the engine torque by the torque assist means is stopped. Since the effectiveness of the traction control can be ensured and unnecessary negative pressure consumption in the vacuum chamber 72 is eliminated, the certainty of the operation of the torque assisting means after the end of the traction control is guaranteed. become.

In the above structure, after the traction control is completed, if the operating region of the engine shifts to the intake switching region or originally exists in the same switching region, the torque assisting means will be activated immediately, but the road surface condition will change. When the vehicle is extremely slippery, the traction control may be restarted again in a short time. In that case, for example, as shown in the flowchart (step S ₄ ) of FIG. 10, the traction control is once completed. Even so, a configuration is adopted in which the above-mentioned prohibited state of the torque assisting means is maintained by a timer within a predetermined time to ensure the stability of control.

Further, in the above embodiment, the torque assisting means is constituted by the variable intake resonance supercharging system, but this can be realized in exactly the same manner as the constitution by the variable intake inertia supercharging system.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to claims of the present invention.

FIG. 2 is a control system diagram of a traction control unit of an engine control device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a configuration of a brake unit of a traction control unit of the control device for the engine.

FIG. 4 is a schematic diagram showing a signal system of a control unit of a traction control unit of the engine control device.

FIG. 5 is a schematic diagram showing a configuration of a torque assist control system of a torque assist control unit of the engine control device.

FIG. 6 is a time chart showing a control pattern of the torque assist control system.

FIG. 7 is a flowchart showing control contents of the traction control system.

FIG. 8 is a flowchart showing the content of torque assist control of the torque assist control system.

FIG. 9 is a control characteristic diagram that is the basis of the torque assist control system.

FIG. 10 shows a modification of the flowchart of FIG.

[Explanation of symbols]

2 is an engine, 8 is a master cylinder, 60a is a first surge tank, 60b is a second surge tank, 81 is an engine control unit, VA and VB are intake switching valves,
UTR is a traction control unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location F02D 43/00 Z 7536-3G F02M 35/10 102 X 9247-3G Y 9247-3G U 9247-3G 301 S 9247-3G

Claims (4)

[Claims] 1. A traction adjusting means for adjusting a torque generated by an engine, a slip detecting means for detecting a slip value of a driving wheel with respect to a road surface, and a slip value detected by the slip detecting means to be a predetermined target value. A traction control means for controlling the traction adjusting means, a torque assist means for increasing the generated torque of the engine, and a torque assist state switching means for switching the torque assist state of the torque assist means according to an operating region of the engine. In a vehicle comprising
A control device for an engine, comprising: a switching prohibiting means for prohibiting a switching operation of the torque assist state switching means when the traction control means is operating. 2. The engine control according to claim 1, wherein even if the operation of the traction control means is stopped, the switching prohibiting operation of the switching prohibiting means is maintained within a predetermined period after the stop. apparatus. 3. The traction adjusting means is torque adjusting means for adjusting the engine torque by changing the combustion state of the engine, and the torque assisting means includes an intake pipe length variable valve for switching the intake pipe length of the engine. It is an intake resonance supercharging means comprising a negative pressure actuator for operating the variable intake pipe length valve and a negative pressure chamber for introducing a negative pressure of an engine intake system and supplying the introduced negative pressure to the negative pressure actuator. The engine control device according to claim 1 or 2, which is characterized in that. 4. The traction adjusting means is torque adjusting means for adjusting the engine torque by changing the combustion state of the engine, and the torque assisting means is an intake capacity variable valve for switching the intake capacity of the engine. It is an intake inertia supercharging means comprising a negative pressure actuator for operating the variable intake capacity valve and a negative pressure chamber for introducing a negative pressure of an engine intake system and supplying the introduced negative pressure to the negative pressure actuator. The engine control device according to claim 1 or 2, which is characterized in that.