JPS6153418A - Variable intake valve device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To provide always proper torque characteristics when the diameter of an intake pipe is controlled by an intake pipe diameter controlling valve, by controllably driving said valve according to optimum opening and closing period determined from load information and intake temperature information. CONSTITUTION:An intake system of an internal-combustion engine provided with a throttle valve for controlling intake air amount and an intake pipe diameter controlling valve provided at the downstream side thereof for controlling the diameter of an intake pipe is also provided with a temperature detecting means 1 for detecting directly internal temperature in the intake pipe and a rotational speed detecting means 4 for detecting the rotational speed of the engine. The output signals of said detecting means 1, 4 are sent to the input of a control means 3 provided in a microcomputer 2 where the optimum opening and closing period of said valve is judged from engine load information and temperature information based upon said rotational speed signal to send the opening and closing signal output to a valve driving means 5. And by said means 5 is opened and closed said valve to control intake air amount.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a variable intake valve device for an internal combustion engine, and more particularly, to a variable intake valve device for an internal combustion engine. The present invention relates to an intake variable valve device for an internal combustion engine that determines the amount of air and supplies a large amount of air to the internal combustion engine.

(Prior art) For example, an internal combustion engine installed in a vehicle such as a four-wheeled vehicle is equipped with an intake system, and this intake system includes a throttle valve that controls the amount of intake air and a valve that controls the diameter of the intake pipe. An intake pipe diameter control valve is installed, and by opening and closing these valves a predetermined amount of air is supplied to the internal combustion engine.The opening and closing timing of this intake pipe diameter control valve depends on the inner diameter of the intake pipe. , its overall length, the number of cylinders of the internal combustion engine, and the speed.

Conventionally, changes in the speed of sound have been ignored when setting the opening and closing timing. However, if the engine speed is varied over a wide range,
The engine's own air suction force reaches its maximum value at a certain rotational speed. This phenomenon is called the dynamic effect of the intake pipe, and it has two types: pulsation effect and inertial effect. The pulsation effect is the positive or negative influence of the pulsating waves that remain in the intake pipe after the intake valve is closed on the next intake process. In addition, the inertia effect is due to the inertia of the air column in the intake pipe, and is mainly influenced by the angle of the intake valve closing timing and the flow resistance coefficient in the air passage.

The pulsation effect and the inertial effect are largely influenced by the speed of sound, and the speed of sound changes depending on the temperature.

FIG. 5 shows the relationship between engine rotational speed and torque when switching control 91 is activated by the intake pipe diameter control valve.

In the figure, when the AI closes the intake pipe diameter control valve,
A2 shows the engine torque curve when opened. B1 shows the torque curve when the intake pipe diameter control valve is closed when the temperature is high, and B2 shows the torque curve when it is opened.

As is clear from these torque curves, with temperature changes,
The switching timing x1 from torque curve A1 to A2 moves to x2 when the temperature rises. However, as described above, this movement amount a is not taken into account when setting the opening and closing timing of the intake pipe diameter control valve.

(Problem to be solved by the invention) In this way, the opening/closing timing of the intake pipe diameter control valve does not take into account changes in the internal temperature of the intake pipe, so the setting of the intake pipe The difference between the opening and closing timing of the diameter control valve becomes large. Therefore, optimal opening/closing control is no longer performed, and the amount of air supplied to the cylinder is small, which affects the output of the engine.

This statement 11 was made against the background of this situation.
The system takes into account the internal temperature of the intake pipe and changes the opening and closing timing of the intake pipe diameter control valve according to this temperature change, supplying the internal combustion engine with the largest amount of air. It is something to do.

(Means for Solving the Problems) In order to solve the problems described in +iiij, the present invention provides a throttle/help for controlling the amount of intake air in the intake system of an internal combustion engine, and controlling the pipe diameter of the intake pipe. an internal combustion engine that opens and closes these valves;
In the open variable intake valve device, a rotation speed detection means detects a rotation speed of the internal combustion engine and outputs a rotation signal; a temperature detection means detects an internal temperature of the intake system and outputs a temperature signal; The optimum opening/closing timing of the intake pipe diameter control valve is determined from the load information based on the rotation signal and the temperature signal or the temperature information based on the temperature signal and the air amount signal from the intake air amount detection means, and the valve driving means and a control means for outputting an opening/closing signal.

(Function) In the present invention, the rotation speed detection means outputs a rotation signal of the internal combustion engine, and the temperature detection means outputs a temperature signal of the intake pipe. Then, the control means calculates the intake air from load information based on the rotation signal and temperature information based on the temperature signal, or from the load information and temperature information based on the temperature signal and the air amount signal of the intake air amount detection means. The optimal opening/closing timing of the pipe diameter control valve is determined by taking into account temperature changes inside the intake pipe.

This provides the largest amount of air to the internal combustion engine,
To reduce the effect of engine torque on temperature.

(Example) The following is an example of this 921J1 based on the attached drawings.
Explain in detail 1.

The ft51 diagram shows an embodiment in which the internal temperature of the intake system is directly detected. 1 is a temperature detection means that directly detects the internal temperature of the intake pipe that constitutes the intake system provided in the internal combustion engine;
A temperature signal is output to control means 3 provided in microcomputer 2. Reference numeral 4 denotes rotational speed detection means, which is disposed, for example, in a distributor, detects the rotational speed, and outputs a rotational signal to the control means 3. The control means 3 determines the optimum opening/closing timing of the intake pipe diameter control valve from the load information of the internal combustion engine based on the rotation signal and the intake pipe temperature information +lJ based on the temperature signal, and outputs an opening/closing signal to the valve driving means 5. do. The valve drive means 5 uses this opening/closing signal to open and close an intake pipe diameter control valve disposed in the intake pipe, thereby adjusting the amount of intake air.

FIG. 2 shows an embodiment in which the internal temperature of the intake system is indirectly detected. In this embodiment, the temperature detection means 1 is provided, for example, at the intake port of an intake pipe, detects the intake air temperature, and outputs an intake temperature signal to the calculation means 6. Similarly, an intake air amount detection means 7 is provided at the intake port to detect the amount of intake air and output it to the calculation means 6 as an air amount signal. The calculating means 6 indirectly detects the internal temperature of the suction pipe based on the suction temperature signal and the air amount signal, and outputs it to the control means 3 as a temperature signal.

FIG. 3 shows a more specific embodiment of the invention.

In the figure, symbol A is a 4-cycle internal combustion engine, B is an ignition device, C is an intake system, D is a fuel supply device, 5 is a valve driving means for driving the intake pipe diameter control valve E, and 2 is a microcontroller that controls each of the above. It's a computer.

A piston 32 is installed in the cylinder 31 of the four-stroke internal combustion engine A.
is arranged to be able to move up and down, and a mixture of fuel and air obtained by the operation of the fuel supply device is supplied to the combustion chamber 33 above the piston 32. At the end of the compression stroke, this air-fuel mixture is transferred to the spark plug 34, which forms part of the 2 tB ignition system.
The explosion causes the piston 32 to move up and down, producing rotational output. The combustion gases are exhausted to the atmosphere through the exhaust system 35.

The ignition device J] is of a non-contact type and is composed of the spark plug 34, an igniter 36, an ignition coil 37, and a distributor 38. The igniter 36 detects the ignition signal from the microcomputer 2 and determines the ignition timing and the energization time on the primary side of the ignition coil 37. The distributor 38 transfers the high voltage generated on the secondary side of the ignition coil 37 to the spark plugs 3 disposed in each cylinder.
Supply to 4. The distributor 38 is provided with a rotational speed detecting means 4 and outputs a one-rotation light signal to the microcomputer 2.

The intake system C includes an intake pipe 39, a surge tank 40 provided in the intake pipe 39, and an air cleaner 42 connected upstream of the surge tank 40 via an air flow meter 41. The air cleaner 42 removes dust from the inhaled air. Further, the air 70 meter 41 measures the intake air amount and outputs the measured air amount to the microcomputer 2 as an air amount signal. Air flow meter 4
Temperature detection means 1 is disposed upstream of 1, and outputs intake temperature information to the microcomputer 2 as a temperature signal.

The surge tank 40 is provided with a throttle valve 43 for controlling the intake amount of air, and an intake pipe diameter control valve E is provided on the downstream side of the surge tank 40 and on the upper Ii side of the fuel supply device.

The fuel supply device injects fuel into the intake pipe 39 according to the load of the internal combustion engine A based on a control signal from the microcomputer 2, thereby obtaining an appropriate air-fuel mixture.

The intake pipe diameter control valve E is opened and closed by a valve driving means 5, and this valve driving means 5 includes an actuator 44,
It is composed of a drive valve 45 and a vacuum tank 46. A diaphragm 47 built into the actuator 44 always biases the intake pipe diameter control valve E in the direction of closing with the tension of the spring 48.
It is moved by pressure fluctuations controlled by 5. Drive valve 4
A solenoid valve 50 biased by a spring 49 is disposed at 5 . When an opening/closing signal is input from the microcomputer 2, the solenoid valve 50 moves against the spring 49 and closes the communication pipe 51 with the vacuum tank 46. A one-way valve 52 is installed in the vacuum tank 46, and when the surge tank 40 is in a reduced pressure state, the diaphragm 47 of the actuator 44 is pulled through the drive valve 45, and the intake pipe diameter control valve E is closed.

The microcomputer 2 includes an A/D converter 53.
Input interface circuit 54, constant voltage voltage [55, CP
It consists of U56, memories 57 and 58, and output interface circuit 59. Battery 60 provides a predetermined voltage to A/D converter 53 and constant voltage power supply 55. Furthermore, the A/D converter 53 has temperature detection means l.
A temperature signal from the air flow meter 41 and an air strain signal from the air flow meter 41 are input, and these analog signals are converted into digital signals. The input interface circuit 54 is a circuit that inputs the rotation signal from the distributor 38. A
/D converter 53 and input interface circuit 5
The detection information input to 4 is transferred to the CPU 56,
or stored in memory 57,58. When the CPU 56 issues an output command, it is compared with the setting information value previously stored in the memory 57, 58, and when they match, the valve driving means 5
An opening/closing signal for driving is output from the output interface circuit 59.

In this embodiment, the internal temperature of the intake pipe 39 is estimated by comparing the temperature signal and the air amount signal with the temperature information value in the memory 57.58 set in advance, and the rotation signal is further stored in the memory 57.58. Compare with speed information value. Then, an opening/closing signal is output at a predetermined time.

In addition, the surge tank 40 is shown as an imaginary line in Figure 3.
A temperature detection means l may be provided inside to directly detect the internal temperature, input the temperature signal to the A/D converter 53, and output the opening/closing signal from this temperature information and rotational speed information. .

Next, the operation of this embodiment will be explained based on FIGS. 3 and 4. The intake pipe diameter control valve E in FIG. 3 shows the opening state during low and medium speed rotation, and FIG. 4 shows the opening state during high speed rotation.

At the time of low-medium speed rotation shown in Fig. t53, the throttle valve 43 disposed on the upstream side of the surge tank 40 is opened half way, and the amount of air sucked into the surge tank 40 is small and the pressure is reduced. As a result, the one-way valve 5 of the vacuum tank 46
2 opens, and the actuator 44 is activated via the drive valve 45.
diaphragm 47 is pulled, and the intake pipe diameter control valve E on the downstream side is closed.

In this way, the amount of air in the intake pipe 39 is restricted, and therefore the amount of air-fuel mixture supplied to the combustion chamber 33 is controlled, and the torque generated in the internal combustion engine A becomes as shown by curve A1 in FIG. 5. At this time, if the temperature of the intake air is high, a torque as shown by the curve Bl is obtained due to the pulsation effect and inertia effect of the intake pipe 39.

Then, when the rotation speed of the internal combustion engine A increases and becomes a high speed rotation, the slow/torque valve 43 is in an open state as shown in FIG. Therefore, the pressure inside the surge tank 40 becomes high, and the one-way valve 52 of the vacuum tank 46 is closed. Therefore, the diaphragm 47 of the actuator 44 is pushed by the spring 48 to open the intake pipe diameter control valve E, and the torque at that time is generated at the intersection Xl with the curve A1 as shown in FIG.
The switching occurs as shown by curve A2.

On the other hand, when the internal temperature of the intake pipe 39 increases during this high speed rotation, the torque becomes as shown by curve B2 in FIG. 5. By the way, the temperature detection means 1 constantly inputs temperature information to the microcomputer 2, and this temperature information and the internal combustion engine A
The optimum opening/closing timing is calculated from the rotation speed information of the valve 45, and an opening/closing signal is output from the output interface circuit 59 to the drive valve 45. As a result, the electromagnetic valve 50 of the drive valve 45 closes the communication pipe 51 with the vacuum tank 46, actuates the actuator 44, and as shown in FIG. It will open at this time, and the amount of intake air will increase.

In this way, the torque curve switches to curve B2 at rotational speed ■1, and the switching timing at this time is point x3, and the intersection point Xi
It is possible to obtain torque that is unaffected by temperature changes at a switching point that is approximately the same.

The opening/closing timing of this intake pipe diameter control valve E is internal combustion engine I3! J
It opens when the rotational speed of A is, for example, 5000 rpm, and 45
The opening/closing operation may have hysteresis so that it closes when the speed reaches 00 rpm.

Additionally, this statement 151 can be similarly applied to an internal combustion engine A equipped with a turbocharger or a supercharger. By changing the internal temperature of the intake pipe, even more precise control becomes possible.

(Effects of the Invention) As described above, the present invention provides load information based on the rotation signal of the rotation speed detection means and temperature signal of the internal temperature of the intake pipe of the temperature detection means, or temperature based on the temperature 0 inch and the air amount signal. Since the optimal opening/closing timing of the intake pipe diameter control valve is determined from the information and the valve driving means is operated, the opening/closing timing of the intake pipe diameter control valve is determined by taking into account temperature changes inside the intake pipe. Ru. Therefore, the control of the intake pipe diameter control valve becomes more precise, a large amount of air is supplied most effectively, the engine torque is less affected by the temperature of the intake air, and the appropriate amount of air is supplied. Obtaining torque characteristics is the turning point.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment in which the internal temperature of the intake system is directly detected to which the present invention is applied, and Fig. 2 is a block diagram showing an embodiment in which the internal temperature of the intake system is indirectly detected to which the present invention is applied. Fig. 3 is a block diagram showing a more specific embodiment to which the present invention is applied, Fig. 4 is a schematic block diagram showing the opening state at high speed rotation, and Fig. 5 is a block diagram showing the opening state at high speed rotation. FIG. 3 is a characteristic diagram showing the relationship between engine rotational speed and torque when controlled. l...Temperature measurement [stage 3...M control means 4...
・Rotational speed detection means 5...Valve drive means 6...Calculation means 7...
Intake air 11f detection means A...Internal combustion engine B...Ignition device C...
Intake system D...Fuel supply device E...Intake pipe diameter control valve

Claims (1)

[Claims] In an intake variable valve device for an internal combustion engine, the intake system of the internal combustion engine is equipped with a throttle valve for controlling the amount of intake air, and an intake pipe diameter control valve for controlling the diameter of the intake pipe, and for opening and closing these valves. , rotation speed detection means for detecting the rotation speed of the internal combustion engine and outputting a rotation signal;
temperature detection means for detecting the internal temperature of the intake system and outputting a temperature signal; and a temperature based on load information based on the rotation signal and the temperature signal, or the temperature signal and an air amount signal from the intake air amount detection means. A variable intake valve device for an internal combustion engine, comprising: control means for determining the optimum opening/closing timing of the intake pipe diameter control valve from the information and outputting an opening/closing signal to a valve driving means.