JP2566144B2 - Throttle valve control device for internal combustion engine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve control device for an internal combustion engine, and more specifically to a vehicle in which a target opening of a throttle valve is corrected according to an engine speed change rate. The present invention relates to a throttle valve control device for an internal combustion engine that prevents a decrease in fuel consumption rate during operation.

(Prior Art) A technique for controlling opening / closing of a throttle valve via an actuator independently of a depression operation of an accelerator pedal has been conventionally known, and an example thereof is a technique described in JP-A-59-99045. Can be done. In this conventional example, the throttle valve is opened / closed to a target opening at an opening / closing speed that does not exceed the control value so that the engine speed can be smoothly increased even during acceleration to eliminate inconveniences such as engine misfire. Is configured.

(Problems to be Solved by the Invention) In such a throttle valve control device, however, there may occur a case where the engine speed rapidly increases during vehicle operation due to a decrease in electric load regardless of the opening / closing operation of the accelerator pedal. In such a case, in the conventional device, since the accelerator pedal is not changed in the depressed position, the target opening of the throttle valve is not changed. Occurred, resulting in a decrease in fuel consumption. In particular, in the case of the control technique for controlling the throttle valve opening for the best fuel efficiency with the intention of improving the fuel efficiency, the throttle valve is controlled to the required minimum opening, and this inconvenience becomes remarkable.

Therefore, an object of the present invention is to eliminate such inconvenience in the prior art, and even if a sudden change in the engine speed occurs due to a reason that is not caused by the depression operation of the accelerator pedal such as an increase or decrease in the electric load, immediately. It is an object of the present invention to provide a throttle valve control device for an internal combustion engine, which makes it possible to correct the target opening degree and thereby avoids a reduction in fuel consumption.

(Means and Actions for Solving Problems) In order to achieve the above-mentioned target, the present invention, as shown in FIG. 1, detects an accelerator opening degree for detecting an opening degree of an accelerator pedal provided on a floor of a driver's seat. Means 10, input of the output of the accelerator opening detection means, the throttle valve drive control value calculation means 14 for calculating the target throttle valve opening based on the accelerator opening detection value and the output of the throttle valve drive control value calculation means In the throttle valve control device for an internal combustion engine, which comprises a throttle valve driving means 16 for driving the throttle valve by inputting, the engine speed detecting means 18 for detecting the engine speed is provided near the rotating part of the internal combustion engine. The throttle valve drive control value calculation means is configured to input the output of the engine rotation speed detection means to calculate the engine rotation speed change rate and to correct the target according to the change rate. .

(Example) Hereinafter, an example of the present invention will be described with reference to FIG.

FIG. 2 shows the overall configuration of the throttle valve control device according to the present invention. In the figure, the accelerator pedal 20 is connected to one end of an arm 22 having a V-shaped cross section, and
A shaft 26 is rotatably installed on the shaft 24. A return spring 28 is mounted on the other end of the arm 22 to urge the accelerator pedal 20 toward the idle position. The shaft 26 is provided with an accelerator opening sensor 32 which is the above-described accelerator opening detecting means including a potentiometer,
It outputs a voltage value according to the rotation angle from the depressed position of the accelerator pedal 20, that is, the idle position around the shaft 26. A throttle valve 40 is provided in the engine intake pipe 34, and a throttle valve opening sensor 44, which is also a potentiometer, is provided on the shaft 42 of the engine intake pipe 34 to output a voltage value according to the opening of the throttle valve 40. A rotary shaft (not shown) of a pulse motor 46 is connected to the shaft 42, and the throttle valve 40 is configured to open and close according to the rotation thereof.

An intake pressure sensor 48 for detecting the intake pressure in the engine intake pipe 34 is provided downstream of the throttle valve, and the crank angle position of the engine is provided in the engine distributor (not shown). A crank angle sensor 50 for detecting the vehicle speed is provided, and a vehicle speed sensor for detecting the speed of the vehicle is provided in the vicinity of a rotating portion of a transmission (not shown) installed behind the engine.
52 and a shift position sensor 54 for detecting the shift position of the transmission. This shift position sensor 54
Is configured to output a digital signal of a binary code corresponding to the shift position by a plurality of switch groups that generate a high level output in conjunction with a shift lever (not shown) of the transmission.

The outputs of the sensors 32, 44, 48, 50, 52, 54 are input to the control unit 60. FIG. 3 shows the details of the control unit 60, and the outputs of the accelerator opening sensor 32, the throttle valve opening sensor 44 and the intake pressure sensor 48 are the control unit 60.
After being input to the microcomputer 64, the level conversion circuit 62 appropriately converts the level to a predetermined level and inputs the level to the microcomputer 64.
The microcomputer 64 comprises an A / D conversion circuit 64a with a multiplexer, an input I / O 64b, a CPU 64c, a ROM 64d, a RAM 64e and an output I / O 64f, and the input value is sequentially converted into a digital value via the A / D conversion circuit 64a. Convert and store temporarily in RAM64e.
The outputs of the crank angle sensor 50, the vehicle speed sensor 52, and the shift position sensor 54 are waveform-shaped by the waveform shaping circuit 66 in the control unit 60 and then input into the microcomputer 64 via the input I / O 64b. Similarly, it is stored in the RAM 64e. The CPU 64c calculates a control value from the input value as will be described later and outputs it to the pulse motor control circuit 68 to drive the pulse motor 46 to open / close the throttle valve 40.
In the above structure, the microcomputer 64 corresponds to the above-mentioned throttle valve drive control value calculating means, and the pulse motor control circuit 68 and the pulse motor 46 correspond to the above-mentioned driving means.

Next, the operation of the throttle valve control device according to the present invention will be described with reference to the flow chart of FIG. It should be noted that this program is started every predetermined period.

First, at step 100, the accelerator angle θACC, throttle valve opening θth, vehicle speed V, engine speed Ne, shift position
Pshifts are read out respectively, and then, in step 102, the accelerator opening change amount ΔθACC is calculated from the difference between the accelerator angle θACC detected this time and the accelerator angle θACC-1 detected last time, and the engine speed Ne detected this time and the engine speed Ne detected last time are calculated. The engine speed change rate ΔNe is calculated from the difference from the engine speed Ne−1. Next, in step 104, the throttle valve 40
The reference opening θth-ref of the accelerator opening θA
Search from ROM64d according to CC. It is assumed that the θACC-θth-ref table is experimentally obtained and stored in advance in the ROM 64d based on proper characteristics.

Then, in step 106, the engine speed change rate ΔNe
The opening correction amount θth-cor is retrieved from the ROM 64d according to
FIG. 5 shows the opening correction amount θ stored in the ROM 64d.
It is a characteristic curve showing th-cor. In the figure, the horizontal axis shows the positive / negative engine speed change rate ΔNe centering on zero, where + ΔNe indicates an increase in engine speed and −ΔNe indicates a decrease in engine speed. . Also, the vertical axis shows the positive and negative opening correction amount θth-cor centering on zero, + θth-cor indicates the correction in the valve opening direction, and -θth-cor indicates the correction in the valve opening direction. . As illustrated, the correction amount increases in proportion to the engine speed change rate, and the larger the change rate, the larger the correction value. Then, in step 108, the reference opening θth-ref
Then, the target opening degree θtho is calculated by adding and subtracting the correction value θth-cor obtained in the previous step. As a result, the target opening degree is increased or decreased by the correction value. Then, step 110
In step 112, the correction coefficient ko is further determined according to the driving condition of the vehicle, and in step 112, the target opening degree θtho is multiplied by the correction coefficient ko to correct the target opening degree θtho. Correction factor k
For example, o is appropriately determined according to operating conditions such as idle operation, high altitude operation, transmission state of the engine power transmission system, vehicle speed V, engine speed Ne, and warm-up.

Subsequently, at step 114, the throttle valve reference drive speed Δθth-ref for the accelerator opening change amount ΔθACC calculated at step 102 is searched from the table in the ROM 64d. FIG. 6 shows such a characteristic, and the characteristic is obtained in advance by an experiment and stored in the ROM 64d. continue,
In step 116, the correction coefficient k1 corresponding to the shift position Pshift of the transmission is retrieved from the ROM 64d. It is assumed that the characteristics shown in FIG. 7 have been previously obtained by experiments and stored therein. Subsequently, at step 118, the correction coefficient k2 corresponding to the vehicle speed V is retrieved from the ROM 64d. FIG. 8 shows this correction characteristic. Next, at step 120, the reference drive speed Δθth-ref is multiplied by the above-mentioned correction coefficients k1 and k2 to calculate the target drive speed Δθtho.

Next, at step 122, the ROM 64d is searched for the upper limit opening θth-max and the lower limit opening θth-min of the throttle valve 40 according to the accelerator angle θACC. A characteristic curve as shown in FIG. 9 is stored in advance in the ROM 64d as a table value.

Subsequently, in steps 124 to 130, the target opening degree θtho is compared with the upper and lower limit opening degree, and if it is exceeded, the limit is limited to that limit, and then in step 132, the actual throttle valve opening degree θth read in step 100 is Target opening θtho
If it is equal, it is not necessary to open and close the throttle valve, so a pulse motor drive stop command is issued to the pulse motor control circuit 68 (step 134). θth
If ≠ θtho, then in step 136, it is determined whether or not the actual opening θth is larger than the target opening θtho, and if it is larger, a pulse motor valve drive command is output to the pulse motor control circuit 68 (step 138), if θth <θtho, a pulse motor valve drive command is output to the pulse motor control circuit 68 (step 140). In the commands of steps 138 and 140, not only the opening but also the speed is specified based on the target drive speed Δθtho calculated in step 120. The command is composed of, for example, 8 bits, and 2 of them is used.
Bits represent drive / stop and drive direction, and the remaining 6 bits are configured to represent drive speed. Further, the pulse motor control circuit 68 is, for example, a frequency synthesizer PLL circuit that generates an oscillation signal at a frequency according to the drive speed information,
A waveform shaping circuit that shapes the oscillation signal into a pulse signal, and a pulse motor that changes the pulse signal according to the drive command information.
It is composed of a logic circuit for supplying / stopping to / from. The pulse motor control circuit 68 supplies a first drive pulse to the pulse motor 46 in response to the pulse motor valve opening drive command, and causes the pulse motor 46 to rotate forward by making the generation cycle of the first drive pulse correspond to the drive speed. The throttle valve 40 is driven in the opening direction to the target opening degree at the target drive speed. Further, the pulse motor 46 is supplied with a second drive pulse having a phase opposite to that of the first drive pulse in response to the pulse motor valve closing drive command, and the generation cycle of the second drive pulse is made to correspond to the drive speed. Is rotated in the reverse direction to drive the throttle valve 40 in the closing direction at the target drive speed up to the target opening. Further, by stopping the supply of the drive pulse in response to the pulse motor drive stop command, the rotation of the pulse motor 46 is stopped and the throttle valve opening at that time is maintained.

In the case of the present embodiment, as described above, even if the accelerator opening is unchanged, if the engine speed changes, the target opening is corrected accordingly, and the target opening is corrected at a predetermined cycle by the program. As a result, the opening degree correction is performed each time. Further, since the correction amount is increased in proportion to the value of the engine speed change rate, when the engine speed suddenly increases, the intake air amount is increased in proportion to the sudden increase amount. The control followability is improved to prevent the intake air amount from becoming insufficient, or at least the insufficiency time can be shortened to prevent the fuel consumption rate from decreasing. In the above embodiment, the correction characteristic of the engine speed change rate is linear as shown in FIG. 5, but may be stepwise as shown in FIG.

(Advantages of the Invention) Since the present invention is configured to correct the target opening of the throttle valve in accordance with the engine speed change rate in the throttle valve control device for an internal combustion engine, it is possible to increase or decrease the electric load regardless of the accelerator operation. Therefore, even if the engine speed suddenly changes, the target opening of the throttle valve can be corrected without delay, and as a result, the optimum intake air amount can be secured and the reduction of the fuel consumption rate can be prevented. It has the advantage of being able to.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a schematic configuration diagram showing an embodiment of a throttle valve control device for an internal combustion engine according to the present invention, and FIG. 3 is a specific configuration of a control unit in FIG. FIG. 4 is a flow chart showing the operation of the control device, FIG. 5 is an explanatory graph showing the correction characteristic of the throttle valve opening corresponding to the engine speed change rate, and FIG. 6 is the accelerator opening. 7 is an explanatory graph showing the reference drive speed characteristic of the throttle valve with respect to the degree change degree, FIG. 7 is an explanatory graph showing the correction characteristic of the throttle valve drive speed with respect to the transmission shift position, and FIG. 8 is a correction characteristic of the throttle valve drive speed with respect to the vehicle speed. FIG. 9 is an explanatory graph showing the upper and lower limit values of the throttle valve opening with respect to the accelerator opening and FIG.
FIG. 10 is an explanatory graph showing another example of the correction characteristic of engine speed change-throttle valve opening degree shown in FIG. 10: Accelerator position detection means (accelerator position sensor 3
2), 14 ... Throttle valve drive control value calculation means (microcomputer 64), 16 ... Throttle valve drive means (pulse motor control circuit 68, pulse motor 46), 18 ...
Engine speed detection means (crank angle sensor 50), 44 ... Throttle valve opening sensor, 60 ... Control unit

Claims (2)

(57) [Claims] Claims: 1. a. Accelerator opening detecting means for detecting the opening of an accelerator pedal provided on the floor of the driver's seat; b. Inputting the output of the accelerator opening detecting means to obtain an accelerator opening detection value. A throttle valve drive control value calculation means for calculating the target throttle valve opening based on the above; and c. A throttle valve drive means for driving the throttle valve by inputting the output of the throttle valve drive control value calculation means. In the throttle valve control device, d. Is provided in the vicinity of the rotating portion of the internal combustion engine, and is provided with engine speed detecting means for detecting the engine speed, and the throttle valve drive control value calculating means is the engine speed detecting means. The throttle valve control device for an internal combustion engine, which is configured to calculate the engine speed change rate by inputting the output of the above and to correct the target opening degree according to the change rate. 2. The throttle valve control device for an internal combustion engine according to claim 1, wherein the target opening degree correction value is increased / decreased in proportion to an increase / decrease in an engine speed change rate.