JP2730771B2 - Engine intake air control system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an engine intake air amount control device that controls an engine intake air amount when shifting to an idle operation state.

(Prior Art) Conventionally, as an intake air amount control device for this type of engine, for example, as disclosed in Japanese Patent Application Laid-Open No. 55-60636, a passage that bypasses a throttle valve is provided in an intake passage of an engine. When shifting to idle operation due to deceleration operation of the engine, the amount of intake air flowing through the bypass passage is increased to suppress a sudden decrease in engine speed due to deceleration operation, reduce shocks and enable so-called stalls It is known to prevent it.

(Problems to be Solved by the Invention) However, during the deceleration operation of the engine, a downshift may be performed in a transmission connected to the engine. For this reason, in the above-described conventional vehicle, the increase control of the intake air amount and the downshift occur during the deceleration operation, and as a result, the engine speed increases as well as gradually decreasing, and the engine speed increases. A drawback results in a temporary blow-up of the number.

The present invention has been made in view of such a point, and an object of the present invention is to temporarily reduce the rotation speed even when a downshift is performed in the transmission during the increase control of the intake air amount during the deceleration operation. The point is that the engine speed is gradually reduced without generating blow-up.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, the amount of increase in the intake air amount during the deceleration operation is set to a different value depending on whether the downshift is performed or not. And

That is, as shown in FIG. 1, a specific solution of the present invention includes an air amount adjusting means 30 for adjusting the intake air amount of the engine, a deceleration detecting means 35 for detecting the time of the deceleration operation of the engine, and Increase control means 36 for controlling the air amount adjusting means 30 to increase the intake air amount of the engine so as to reduce the shock during the deceleration operation detected by the deceleration detecting means 35.
It is assumed that an intake air amount control device for an engine having: A shift detecting means 29 for detecting a shift state of the transmission connected to the engine, and a downshift in which the gear ratio is reduced by the shift detecting means 29 during the increase control of the intake air amount by the increase control means 36. When time is detected, a limiting means 37 for limiting the increase in the amount of intake air to a small amount is provided.

(Operation) According to the above configuration, according to the present invention, during the deceleration operation of the engine, the intake air amount is basically increased by a predetermined amount by the increase control means 36, so that the sudden decrease in the engine speed is suppressed, and the shock is reduced. Reduced.

At this time, if a downshift occurs in the transmission, the increase in the intake air amount is limited to a smaller amount by the limiting means 37 than when there is no downshift, so that the degree of suppressing a sudden decrease in the engine speed is reduced. Since the engine speed is moderate, the engine speed is not temporarily increased, and the temporary increase in the engine speed is effectively prevented.

(Effects of the Invention) As described above, according to the engine intake air amount control device of the present invention, even if a downshift is performed in the state where the intake air amount increase control is performed during the deceleration operation, the engine speed is reduced. Since the degree of suppression of the sudden decrease in the number can be appropriately adjusted, the engine speed can be gradually reduced,
It is possible to prevent a temporary increase in the engine speed.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 shows the overall configuration of the engine intake air amount control device according to the present invention. In FIG. 1, reference numeral 1 denotes an engine, 2 denotes a combustion chamber variably formed by a piston 4 slidably fitted into a cylinder 3 of the engine 1, and 5 has one end communicating with the atmosphere via an air cleaner 6. An intake passage 7 whose other end communicates with the combustion chamber 2 and supplies intake air to the engine 1;
Is an exhaust passage having one end communicating with the combustion chamber 2 and the other end communicating with the atmosphere to discharge exhaust gas. A throttle valve 8 for controlling the amount of intake air and a fuel injection valve 9 for injecting fuel to the engine 1 downstream of the throttle valve 8 are arranged in the middle of the intake passage 5. An intake valve 10 is provided at an opening of the intake passage 5 to the combustion chamber 2, and an exhaust valve 11 is provided at an opening of the exhaust passage 7 to the combustion chamber 2.

A bypass passage 15 for bypassing the throttle valve 8 is provided upstream and downstream of the throttle valve 8 in the intake passage 5. A bypass passage 15 is provided in the middle of the bypass passage 15.
Control valve 16 for increasing or decreasing the passage area of
By adjusting the passage area of the bypass passage 15 by the control valve 16, the amount of bypass air flowing through the bypass passage 15 is increased / decreased and corrected to adjust the amount of intake air to the engine 1. ing. And engine 1
During the deceleration operation, the amount of bypass air is increased and corrected (hereinafter, referred to as a dashpot) to suppress a rapid decrease in the engine speed.

Further, reference numeral 17 denotes an automatic transmission connected to the output shaft 1a of the engine 1. The automatic transmission 17 includes a torque converter 18 having a pump 18a, a stator 18b, and a turbine 18c therein, and an output shaft (turbine shaft 18) of the converter 18.
For example, there is provided a speed change gear mechanism 19 connected to d), for example, four forward steps and one reverse step.

In addition, reference numeral 20 denotes an air flow sensor for measuring the amount of intake air upstream of the throttle valve 8 in the intake passage 5 of the engine 1;
Is an intake air temperature sensor that detects the intake air temperature near the air flow sensor 20, 22 is an opening sensor that detects the opening of the throttle valve 8, 23 is an idle switch that detects when the throttle valve 8 is fully closed, and 24 is A crank angle sensor for detecting a crank angle of the engine 1, a cooling water temperature sensor 25 for detecting a temperature of an engine cooling water, and a sensor 26 for detecting an engine speed from an operating state of a distributor for supplying a high voltage to a cylinder in an explosion stroke. It is a rotation speed sensor. Thus, the detection signals of the sensors 20 to 26 are input to an engine controller 27 having a CPU and the like inside, and the controller 27 controls the control valve 16 to control the passage area of the bypass passage 15, that is, The amount of bypass air is controlled.

In addition, in the figure, reference numeral 28 denotes an automatic transmission controller for controlling the automatic transmission 17;
Is a hydraulic control circuit (not shown) of the transmission mechanism 19
Has a function of controlling the plurality of solenoid valves SOL to perform automatic shifting according to the vehicle speed and the opening of the throttle valve 8. The controller 28 is provided with a shift detecting means for detecting a shift state of the transmission mechanism 19 by a shift control performed internally.
It has a function as 29, and also has a function to transmit the shift state signal to the engine controller 27.

Next, the control valve 16 by the engine controller 27 is used.
Will be described based on the control flow of FIG.

After starting, the engine speed at step S _1, then is loaded the shifting state signal from the idle switch status and the automatic transmission controller 28, dashpot executable flag FIDP (originally FIDP = 0 in step S ₂ the value of the initial setting) to determine, since initially is FIDP = 0, respectively determine the state of the engine rotational speed Ne and the idle switch 23 in step S ₃ and S _4, Ne <a (a dashpot a setting rotational speed for starting), and when the idle switch 23 is switched to the oN start this time, the throttle valve opening is determined to be the deceleration operation of the fully closed, dashpot in step S ₅ Set the executable flag FIDP = 1.

Thereafter, again to determine the engine speed Ne at step S _6, when it becomes A> Ne by the rotation speed decreases, further shifting state signal from the automatic transmission controller 28 in step S ₇ the second gear only when (shift execution flag FAT = 0) is a signal indicating that it is not a time downshift to the first speed, after setting the dashpot execution flag FDP to FDP = 1 in step S _8, the dash in step S ₉ The pot amount (the increase in the amount of air flowing through the bypass passage 15) is initially set to a predetermined value x.

Then, only when the idle switch 23 is the throttle valve opening to maintain the ON state is fully closed in step S _10, if not during a shift of the shift execution flag FAT = 0 in step S _11, the dash in Step S ₁₂ pot amount from the initial value x by subtracting the attenuation amount KIDGDP of fine, after dashpot amount x was repeated steps S ₁₀ to S ₁₃ until x = 0 in step S _13, dashpot in step S ₁₄ Set the executable flag FIDP and the dashpot execution flag FDP to FIDP = 0, FDP
= Returns to the step S ₁ is returned to 0.

On the other hand, a dashpot amount in step S _9, even when set to x value, the idle switch 23 in step S ₁₀ is O
When the throttle valve opening is no longer fully closed at FF, or when the shift execution flag FAT = 1 and the transmission 17
When the down-shift to speed is performed, it resets the dashpot volume to zero value in step S _15.

Therefore, in the control flow of FIG.
The S ₃ and S _4, the engine rotational speed is determined that and throttle valve opening in Ne> A is fully closed, constitute a deceleration detecting means 35 for detecting a deceleration operation of the engine.
Further, in step _{S 6, S 8 ~S 10,} S 12, S 13, the deceleration operation is detected by the deceleration detecting means 35 the amount of bypass air in the bypass passage 15 by controlling the control valve 16 of the air control means 30 An increase control means 36 is configured to increase the intake air amount of the engine by increasing the amount. Further, in step S ₁₁ and S ₁₅ of the control flow, during which initializes the dashpot volume to a predetermined value x at increasing control means 36 has increase control the intake air amount, by the shift detection means 29 When the downshift from the second speed to the first speed at which the gear ratio is on the deceleration side is detected and the shift execution flag FAT becomes FAT = 1, the dashpot amount is forcibly set to zero value, The limiting means 37 is configured to limit the increase in the amount of intake air to a small amount.

Therefore, in the above embodiment, as shown in FIG. 4, the engine speed Ne is changed to the dashpot execution speed A.
In the deceleration operation in which the throttle valve is fully closed and the idle switch 23 is turned off in a situation where the engine speed Ne exceeds the engine speed Ne to the dashpot execution speed A, the dashpot amount becomes the predetermined value x. Initialized. Then, as long as the automatic transmission 17 does not shift while the throttle valve opening is kept fully closed as it is,
The dashpot amount attenuates from the initial value x by the amount of attenuation KIDGDP. As a result, even if the throttle valve opening is fully closed, the engine speed Ne is suppressed from abrupt decrease by the increase in the amount of bypass air, and smoothly drops.

Now, during the above-described deceleration operation, a downshift is performed by the automatic transmission 17 according to the deceleration, and when the dashpot amount is attenuated, for example, when there is a downshift from the second speed to the first speed. Conventionally, the dashpot amount continues to be gradually attenuated as shown by the broken line in the figure, so that both the presence of the dashpot amount and the downshift cause the engine speed to temporarily decrease as shown by the broken line in the figure. However, in this embodiment, the dashpot amount after the downshift to the first speed is forcibly set to zero value, so that even if there is a downshift to the first speed, the engine speed increases. The number of revolutions smoothly drops as shown by the solid line in the figure without causing a temporary blow-up.

In the above-described embodiment, the dashpot amount is forcibly set to the zero value during the downshift, but the present invention is not limited to this, and the point is to limit the increase in the intake air amount during the deceleration operation to a small amount. What should I do?

Further, in the above embodiment, the case where the transmission is the automatic transmission 17 has been described. However, it goes without saying that the transmission may be a manual transmission.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 4 show an embodiment of the present invention, FIG. 2 is an overall configuration diagram, FIG. 3 is a flowchart showing control of a bypass air amount by a controller, and FIG. 4 is an operation explanatory diagram. DESCRIPTION OF SYMBOLS 1 ... Engine, 8 ... Throttle valve, 15 ... Bypass passage, 16 ... Control valve, 17 ... Automatic transmission, 19 ... Transmission mechanism, 23 ... Idle switch, 27 ... Engine controller, 28 ... automatic transmission controller, 29 ... shift detecting means, 30 ... air amount adjusting means, 35 ... deceleration detecting means, 36 ... increase control means, 37 ... limiting means.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-200026 (JP, A) JP-A-62-223431 (JP, A) JP-A-62-247139 (JP, A) JP-A 62-223139 271946 (JP, A) JP-A-63-29034 (JP, A) JP-A-63-65145 (JP, A) JP-A-63-268947 (JP, A)

Claims (1)

(57) [Claims] 1. An air amount adjusting means for adjusting an intake air amount of an engine, a deceleration detecting means for detecting a time of deceleration operation of the engine, and an engine for reducing a shock at the time of deceleration operation detected by the deceleration detection means. Increase control means for controlling the air amount adjusting means to increase the intake air amount of the engine, shift detection means for detecting a shift state of a transmission connected to the engine, and increase control of the intake air amount by the increase control means An intake air amount control device for an engine, further comprising: limiting means for limiting the increase in the amount of intake air to a small amount when a downshift in which the gear ratio is reduced is detected by the shift detecting means. .