JPH0650191A - Intake air quantity controller during of deceleration of internal combustion engine - Google Patents

Abstract

PURPOSE:To provide an intake air quantity controller during deceleration of an internal combustion engine which can exhibit a brake servo effect of a brake assistor even if air pressure becomes low. CONSTITUTION:An AIC control valve 108 is controlled in its closure by an ECU 109 at the time of detecting a low air pressure of an atmospheric pressure sensor 120, and supply of auxiliary to an engine is shut out from the time of detecting the deceleration condition of an engine 100 for a specified time. Consequently, negative pressure in the negative pressure 2 of a brake booster 1 communicated to the intake side of the engine 100 is raised, and differential pressure between an atmospheric pressure chamber 3 and a negative pressure chamber 2 of the brake booster 1 is generated sufficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deceleration intake air amount control device for an internal combustion engine, and more particularly to a deceleration intake air amount control device that operates to sufficiently exert a brake boosting effect of a brake booster. Is.

[0002]

2. Description of the Related Art Conventionally, a bypass passage for bypassing a throttle valve in an intake passage of an internal combustion engine, a control valve provided in the bypass passage for adjusting the amount of auxiliary air supplied to the engine, and a target idle speed of the engine Intake at idle of an internal combustion engine for a vehicle, which is provided with a control means for obtaining a deviation from an actual rotation speed and feedback-controlling the control valve according to the deviation so that the actual rotation speed becomes equal to the target idle rotation speed. An air amount control device (hereinafter referred to as EACV) is known, for example, from Japanese Patent Laid-Open No. 62-3147. This intake air control device is configured to supply a required amount of auxiliary air to the engine even in the deceleration state toward the idle state to improve the convergence to the idle speed and prevent the engine speed from dropping and the engine stall. ing.

Further, although a hydraulic brake is generally used as a braking device for a vehicle, such a hydraulic brake is generally connected integrally with a master cylinder for supplying braking pressure oil to a wheel cylinder of each wheel of the vehicle. A brake force multiplying device (hereinafter, referred to as “brake booster”) that amplifies the pedaling force and transmits it to the master cylinder is provided. As shown in FIG. 7, this brake booster 1 takes in a negative pressure from an intake pipe of an internal combustion engine of a vehicle into a negative pressure chamber (master bag) 2 through a check valve and depresses the atmospheric pressure when the brake pedal is depressed. The output rod 5 presses the piston 7 of the master cylinder 6 against the elastic force of the spring 4 and operates the piston 7 in response to the pressure difference between the two chambers.

More specifically, in a normal condition in which the vehicle is running with the accelerator pedal depressed (the brake petal is not depressed).
The throttle valve in the intake pipe of the engine is open.
Further, the valve 1b and the valve 1c are closed, the negative pressure chamber is held by the check valve 1a-1 at the pressure in the intake pipe at the time of idling, and the atmospheric pressure chamber 3 has the spring 4 from the pressure of the negative pressure chamber 2.
There is a slightly higher pressure to counter. After that, when the brake pedal is stepped on, the valve 1b is opened, and the atmosphere is introduced into the atmosphere chamber 3 so that the pressure rises, so that the differential pressure between the negative pressure chamber 2 and the atmosphere chamber 3 increases, and the elastic force of the spring 4 is counteracted. Then, the output rod 5 presses the piston 7 of the master cylinder 6 to boost the braking force. When the brake petal returns to its original state, the valve 1b is closed and the introduction of the atmosphere into the atmosphere chamber is stopped.
, The air in the atmosphere chamber 3 is sucked into the intake pipe of the engine through the valve 1b and the negative pressure chamber 2, and the pressure in the atmosphere chamber 3 is lowered to return to the state before the brake pedal is depressed.

An example of the boosting characteristic of the brake booster 1 is shown in FIG. This characteristic diagram shows negative pressure chamber 2 and atmosphere chamber 3.
The characteristics in the case where the pressure difference between and is 0 mmHg and 500 mmHg are shown. The input in the figure shows the stepping force of the brake petal, and the output shows the multiplied stepping force output from the master cylinder 6, respectively.

As the intake system of the engine to which the brake booster 1 is connected, there are generally a single bore throttle system and a multiple throttle system.

FIG. 9 is a diagram showing a configuration example of the intake pipe of the single-bore throttle system in a vehicle equipped with the EACV, and FIG. 10 is a diagram showing an example of a negative pressure waveform of the intake pipe in the single-bore throttle system. Is. In the waveform diagram of FIG. 10, the engine speed Ne = 4500 rpm and the opening of the throttle valve 14 is 20 °, 24 °, 32 °, 34.
Change to °, 41 °, 64 °, 90 ° and measure point P in Fig. 9
This is a measurement of negative pressure at one point, where the horizontal axis represents the crank angle and the vertical axis represents the pressure. Further, A to D in the figure represent the top dead center at the start of the intake stroke of each cylinder.

In FIG. 9, an intake pipe 11 connected to, for example, a three-cylinder internal combustion engine 10 has branch passages 11a, 11b and 11c communicating with each cylinder of the engine 10, a chamber 12 for accumulating a negative pressure, and the above-mentioned drawing. The negative pressure passage 1a and the EACV communicating with the negative pressure chamber 2 of the brake booster 1 shown in FIG.
And a negative pressure passage 13 communicating with the chamber 1.
A throttle valve 14 is attached near the atmosphere supply port 2.

The intake wave generated by each stroke of intake, compression, explosion, and exhaust in each cylinder of the engine 10 is combined in the three branch passages 11a to 11c, and the pulsating standing as shown in FIG. Forming a wave, negative pressure passage 1
The negative pressures taken out from a and 13 have almost the median values of the respective waveforms at each opening of the throttle valve 14. The median values are -350, -250, -1 in FIG.
40, -100, -60, -30, -22 mmHg are shown.

FIGS. 11 (a) and 11 (b) are views showing a schematic configuration example of an intake pipe of a triple throttle system in a vehicle equipped with the EACV, and FIG. 11 (a) is a plan view of the intake pipe. 2B is a sectional view taken along line A, A'of FIG. FIG. 12 is a diagram showing a negative pressure waveform of the intake pipe in the triple throttle system. In the waveform diagram of FIG. 12, the engine speed Ne = 4500 rpm, the opening of the throttle valve 14 is 16.5 °, 18.5 °, 21 °,
Change to 23 °, 25 °, 32 °, and 52 °, as shown in FIG.
The negative pressure is measured at the measurement point P2 in FIG.
Similarly, the horizontal axis represents the crank angle, the vertical axis represents the pressure, and A to D in the figure represent the top dead center at the start of the intake stroke of each cylinder.

In FIGS. 11 (a) and 11 (b), an intake pipe 21 connected to a three-cylinder internal combustion engine 20 has branch passages 21a, 21b, 21 communicating with each cylinder of the engine 20.
c and the chamber 22. Throttle valves 22a, 22b, 22c are provided near the chamber openings of the respective branch passages 21a, 21b, 21c. Further, the branch passages 21a, 21b, between the throttle valves 22a, 22b, 22c and the engine 20.
21c has holes formed therein, and a communication passage 23 that connects the respective branch passages 21a, 21b, 21c through the holes is attached. The communication passage 23 has a negative pressure passage 1a communicating with the negative pressure chamber 2 of the brake booster 1 shown in FIG. 7 and a negative pressure passage 24 communicating with the EACV.

Since the chamber 22 is provided on the upstream side of the throttle valves 22a, 22b, 22c, unlike the above-mentioned single bore throttle system, the pressure inside the chamber 22 is almost equal to the atmospheric pressure and the pulsating standing wave is generated. Is not formed. Further, the pressure change in each branch passage 21a, 21b, 21c shifts to the atmospheric pressure side except the intake stroke as shown in the negative pressure waveform shown in FIG. 12, as compared with the single bore throttle system. This is because, for example, when the cylinder on the side of the branch passage 21a is in the intake stroke (the intake valve of the engine opens and the piston lowers), the air in the chamber 22 flows only through the throttle passage 22a toward the branch passage 21a, Other branch passage 21
There is almost no air flow to b and 21c. Therefore, even if the intake stroke ends in the cylinder on the side of the branch passage 21a and the intake stroke shifts to another branch passage, for example, the cylinder on the side of the branch passage 21b, the intake stroke affects the air flow in the branch passage 21a. The pressure at the measurement point P2 in the branch passage 21a after the intake stroke is close to the atmospheric pressure of the chamber 22.

[0013]

However, if the atmospheric pressure is lowered while traveling in a highland, the differential pressure between the negative pressure chamber 2 and the atmospheric pressure chamber 3 when the brake pedal is depressed is reduced, and the brake boosting force is sufficient. There was a problem that could not occur. This phenomenon is particularly remarkable in the multiple throttle engine.

That is, in FIG. 13, assuming that the engine at the time of idling is a negative pressure pump, the pump efficiency is constant regardless of the atmospheric pressure, so that an engine generating a differential pressure of -450 mmHg on the brake booster 1 on a level ground is , At an altitude of 2700 m, the pressure difference becomes -320 mmHg, and the obtained differential pressure is 130 mmHg lower than the level ground. In the case of the multiple throttle system, as described above, the negative pressure supplied to the negative pressure chamber 2 shifts to a value smaller than 130 mmHg to the atmospheric pressure side and becomes a small value.
The pressure inside is also low. Therefore, the differential pressure between the negative pressure chamber 2 and the atmospheric chamber 3 becomes small, so that the necessary differential pressure between the negative pressure chamber 2 and the atmospheric chamber 3 cannot be obtained, and the boosting characteristic described in FIG. There was a problem that the effectiveness of the.

In view of the above-mentioned conventional problems, the present invention provides an intake air amount control device for deceleration of an internal combustion engine, which is capable of sufficiently exerting the brake boosting effect of the brake booster even when the atmospheric pressure becomes low. To aim.

[0016]

In order to achieve the above object, the present invention provides deceleration detection means for detecting that an internal combustion engine is in a deceleration state, and a valve for adjusting the amount of auxiliary air supplied to the engine. In the deceleration intake air amount control device for an internal combustion engine, comprising: a means for controlling the valve means when detecting the deceleration state to supply auxiliary air, an atmospheric pressure detection means for detecting the atmospheric pressure, Auxiliary air supply prohibiting means for controlling the control means to shut off the supply of auxiliary air from the valve means to the engine when the atmospheric pressure is lower than a predetermined value is provided.

The auxiliary air supply prohibiting means may be configured to interrupt the supply of the auxiliary air for a predetermined time after the deceleration state of the engine is detected.

Further, when the brake switch is turned on or the degree of decrease of the engine speed becomes larger than a predetermined value within the predetermined time, the supply of the auxiliary air by the auxiliary air supply prohibiting means is cut off. Prohibition cancellation means for canceling may be provided. Further, the engine is preferably a multiple throttle system.

[0019]

According to the present invention, when the low atmospheric pressure is detected by the atmospheric pressure detecting means, the auxiliary air supply prohibiting means controls the control means to close the valve means, and when the deceleration detecting means detects the deceleration state of the engine. Preferably, the supply of auxiliary air to the engine is shut off for a predetermined time period from the time of detection. As a result, when the negative pressure chamber of the brake booster communicates with the intake side of the engine, the negative pressure of this negative pressure chamber rises, and the differential pressure between the atmospheric pressure chamber and the negative pressure chamber of the brake booster increases. Can be obtained enough.

Further, the prohibition canceling means cancels the interruption of the supply of the auxiliary air by the auxiliary air supply prohibiting means when the brake is operated within the predetermined time or the engine speed is drastically reduced. Thereafter, the valve means is controlled by the control means, which prevents stalling.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an embodiment of a deceleration intake air amount control device according to the present invention.

Reference numeral 100 in FIG. 1 denotes an internal combustion engine of, for example, three cylinders mounted on a vehicle (not shown).
An intake pipe 102 and an exhaust pipe 103 to which a chamber 101 having a predetermined capacity is attached are connected to 0. The chamber 101 is connected to the upstream end of the intake pipe 102.
The intake pipe 102 has branch passages 102a, 102b, 102c corresponding to respective cylinders of the engine.
Throttle valves 104, 105 housed in a throttle body (not shown) in the middle of 2a, 102b, 102c,
106 are arranged respectively. This throttle valve 1
Reference numerals 04, 105, and 106 are attached to a common support shaft, and the support shaft is rotationally driven in association with a depression operation of an accelerator pedal (not shown) to cause the throttle valves 104, 1 to rotate.
The openings of 05 and 106 are changed. Note that the valve opening degree (θTH) of the throttle valves 104 to 106 is the throttle valve opening sensor 104A provided on the support shaft.
Detected by. An auxiliary air passage 107 that bypasses the throttle valves 104, 105, and 106 communicates with the chamber 101.

An auxiliary air amount control valve (hereinafter simply referred to as "AIC control valve") 108 is arranged in the middle of the auxiliary air passage 107 and forms an EACV together with the passage 107. The AIC control valve 108 cooperates with an electronic control unit (hereinafter referred to as “ECU”) 109, which will be described later, to control the idle speed of the engine, and the valve opening (the opening area of the passage 107) of the AIC control valve 108 is the ECU 109. Controlled by the drive current from the. In this embodiment, as the AIC control valve 108, a solenoid 108a connected to the ECU 109 and the auxiliary air passage 1 by an opening degree (valve lift amount) corresponding to the drive current ICMD when the solenoid 108a is energized.
A so-called linear solenoid type electromagnetic valve including a valve body 108b that opens 07 is used.

On the other hand, each throttle valve 104, 105, 1
Each branch passage 1 between the engine 06 and the engine 100.
02a, 102b, 102c are perforated,
Each branch passage 102a, 102b, 102 is passed through the hole.
A communication passage 110 communicating with c is attached. The communication passage 110 communicates with the downstream end of the auxiliary air passage 107 with the AIC control valve 108 interposed, and the catch valve is provided in the negative pressure passage 1a leading to the negative pressure chamber 2 of the brake booster 1 similar to that shown in FIG. It communicates via 1a-1. Fuel injection valves 111, 112, 113 are provided in each branch passage between the communication passage 110 and the engine 100. The fuel injection valves 111 to 113 are connected to a fuel pump (not shown) and electrically connected to the ECU 109. Connected to each other.

Further, the intake pipe absolute pressure sensors 114, 115 and 116 for detecting the absolute pressure (PBA) in the respective branch passages 102a to 103c are respectively provided in the respective branch passages 102a to 1c.
It is attached to 03c.

An engine cooling water temperature (Tw) sensor 117 is mounted in each cylinder peripheral wall filled with the cooling water of the engine 100, and each sensor is electrically connected to the ECU 109 to supply the detection signal to the ECU 109. To do.

An engine speed (Ne) sensor 1 is provided around a cam shaft or crank shaft (not shown) of the engine 100.
18 is attached. The Ne sensor 118 sequentially generates a crank angle position signal (hereinafter referred to as "TDC signal") at a crank angle position that is a predetermined crank angle before the top dead center at the start of the intake stroke of each cylinder. It is supplied to the ECU 109.

Further, a brake switch 119 is connected to the ECU 109, and the switch is connected to a brake pedal of a hydraulic brake mechanism of a vehicle (not shown), and is turned on when the pedal is depressed, and turned off when the pedal is returned. The on / off signal of the switch 119 is the ECU
109 is supplied. The hydraulic brake mechanism is equipped with a brake booster 1 integrally connected to a master cylinder 6 similar to that shown in FIG.
The negative pressure within 0 is introduced into the atmospheric pressure chamber 3 respectively.

Further, the ECU 109 includes an atmospheric pressure sensor 1
20 and other required sensors and switches (not shown)
Are connected and electric signals are supplied from them.

The ECU 109 constitutes deceleration detecting means, control means, auxiliary air supply prohibiting means, and prohibiting canceling means.

The ECU 109 shapes the waveforms of the detection signals from the various sensors and switches described above, corrects the voltage level to a predetermined level, and converts the analog signal value into a digital signal value. , Central processing circuit (hereinafter referred to as "CPU") 109b, CPU1
Storage means 109c for storing various calculation programs executed in 09b and calculation results, and the fuel injection valve 111.
˜113 and an output circuit 109d for supplying a drive signal to the AIC control valve 108 and the like. And ECU
Reference numeral 109 determines the operating state of the engine based on the engine operating parameter signal values from the various sensors, calculates the valve opening time of the fuel injection valves 111 to 113 according to the operating state by a known method, and Air amount, that is, the valve opening command value I of the linear solenoid type AIC control valve 108
CMD is determined based on a predetermined program, and drive signals corresponding to the calculated values are supplied to the fuel injection valves 111 to 113 and the AIC control valve 108 via the output circuit 109d.

Next, the operation of this embodiment will be described with reference to FIGS.
Will be described with reference to.

First, the main routine of the EACV control in this embodiment will be described with reference to the flow charts of FIGS. The programs shown in FIGS. 2 and 3 and later-described FIGS. 5 and 6 are executed in synchronization with each generation of the TDC signal.

In step S1 in FIG. 2, the valve opening correction value IDEC of the AIC control valve 108 is determined based on the IDEC table shown in FIG. This valve opening correction value IDEC is
It is applied in the deceleration mode described later,
The intake pipe 102 is provided in order to prevent a sudden decrease in the engine speed during engine deceleration toward the idle speed to prevent engine speed overshoot and engine stall.
It corresponds to the amount of auxiliary air that flows into the. According to the IDEC table of FIG. 4, the valve opening correction value IDEC decreases as the engine speed decreases, and the predetermined value (1500 r
It is set to zero below pm).

In a succeeding step S2, a valve opening correction value IPS corresponding to the amount of auxiliary air to be introduced into the intake pipe 102 in response to the operation of the power steering is determined, and the step S2 is further executed.
In 3, the valve opening degree correction value IHAC corresponding to the amount of auxiliary air that flows into the intake pipe 102 when the air conditioner is operated is determined by a predetermined subroutine. In step S4, it is determined whether or not the flag FISTP that cuts the auxiliary air flowing into the intake pipe 102 when the engine is decelerated is 1, and if the answer is negative (NO), that is, FISTP = 0, then the process proceeds to step S5. move on. The setting of the flag FISTP in step S4 is determined by a subroutine described later.

In step S5, it is determined whether the engine 100 is in the fuel cutoff (fuel cut) state. If the answer is affirmative (YES), the valve opening of each throttle valve 104-106 is determined in step S6. Whether θTH is smaller than a predetermined value θFC (for example, 2 °), that is, the throttle valve 10
It is determined whether all of 4 to 106 are fully closed. If the answer is affirmative (YES), the process proceeds to step S7, and it is determined whether the engine cooling water temperature TW is higher than a predetermined value TWM1 (for example, 40 °), that is, whether it is a high temperature. When the answer is affirmative (YES), that is, engine 100
Is in the fuel cut state, and the throttle valves 104 to 1
When 06 is fully closed and the engine coolant temperature TW is high, it is determined that the engine 100 is in the deceleration state and the deceleration mode of step S8 is entered. In the deceleration mode, the valve opening correction value IDEC determined in step S1 is applied to the calculation of the valve opening command value ICMD described later.

If the determination result of any of steps S5, S6, S7 is negative (NO), the process proceeds to step S9, where the engine speed NE is a predetermined speed NLASTP (for example, 5).
000 to 6000 rpm), that is, whether or not the rotation speed is high. If the answer is affirmative (YES), in step S10, the sleep mode in which the EACV function is stopped is entered. As a result, the engine vibration at high rotation is E
It is possible to prevent the failure of the EACV transmitted to the ACV. Further, in the present invention, when the determination result of the step S4 is affirmative (YES), that is, when FISTP = 1, the sleep mode of the step S11 is entered and the main routine is ended. Note that this point will be described in detail in a subroutine described later. In the rest mode, the valve opening command value ICMD
Becomes zero and the supply of auxiliary air is stopped.

On the other hand, the determination result of step S9 is negative (N
O), that is, when the engine speed is not high, the feedback control mode of step S11 is entered to increase / decrease the auxiliary air amount according to the deviation between the target idle speed and the actual engine speed. Value I
Determine FB.

The valve opening correction value IDE determined as described above
C, IPS, IHAC and the feedback control value IFB are added to calculate the valve opening command value ICMD (opening area) of the AIC control valve 108 (step S12), and the main routine ends.

The valve opening command value I calculated in this way
The solenoid 108a of the AIC control valve 108 is energized with a current value according to CMD to control the opening of the valve element 108b. A required amount of auxiliary air corresponding to the opening area of the auxiliary air passage 107 determined by the control position of the valve body 108b is supplied to the auxiliary air passage 107, the communication passage 110, and the intake pipe 10.
2 to the engine 100. When the valve opening command value ICMD is increased to increase the opening area to increase the auxiliary air, the supply amount of the air-fuel mixture to the engine 100 increases, the engine output increases, and the engine speed increases. On the contrary, if the valve opening command value ICMD is reduced to decrease the opening area, the supply amount of the air-fuel mixture is decreased and the engine speed is decreased.

Next, with reference to the flow charts of FIGS. 5 and 6, the FI which is a subroutine of the EACV process.
The STP determination process will be described.

First, in step S20 in FIG. 5, it is determined whether the atmospheric pressure PA detected by the atmospheric pressure sensor 120 is smaller than a predetermined value PABK (for example, 600 mmHg), and the answer is affirmative (YES). That is, when the atmospheric pressure is low, the process proceeds to step S21. In step S21, the engine cooling water temperature TW is set to a predetermined value TWBKL (for example, 0
Angle) and a predetermined value TWBKH (for example, 40 °), and if the answer is affirmative (YES), the engine speed NE is further set to a predetermined value NBK (for example, 2000 rpm) in step S22. It is determined whether or not the above. And
If the answer to step S22 is affirmative (YES), the process proceeds to step S23, where the vehicle speed W is a predetermined value WBK (for example, 8 KM).
/ H) or more, and if the answer is affirmative (YES), the process proceeds to step S24 in FIG. That is, when it is determined that the vehicle is traveling in the highland of low pressure at the normal speed in the determination process of steps S20 to S23,
I will proceed to 24.

In step S24, the throttle valve 104
It is determined whether or not the current value θTHn of the throttle valve opening of ~ 105 is smaller than the previous value θTHn-1. That is, it is determined whether the engine is decelerating, and the answer is affirmative (Y
If ES), the process proceeds to step S25, and the throttle valve 1
It is determined whether or not the degree of change ΔTH of the throttle valve opening of 04 to 105 is larger than a predetermined value ΔTHG (for example, 0.6d). That is, it is determined whether or not the throttle valves 104 to 105 are closing with an appropriate degree of change, and if the answer is negative (NO), the process proceeds to step S26. Step S
At 26, it is determined whether or not the valve opening degree θTH of the throttle valves 104 to 106 is smaller than a predetermined value θFC (for example, 2 °).

If the determination result of any of steps S20 to S24 is negative (NO), or the determination results of steps S25 and S26 are negative (NO),
In step S27, the timer is reset to a predetermined value TIBK (for example, 0.3 sec) and down counting is started. The predetermined value TIBK is the time until the negative pressure inside the negative pressure chamber 2 of the brake booster 1 becomes negative. At the same time, the flag FISTP = 0 in step S28.
And Therefore, at this time, the sleep mode of step S11 shown in FIG. 3 is not established.

On the other hand, step S25 or step S2
When the determination result of 6 is affirmative (YES), that is, when the throttle valve 104 is closing or fully closed,
The accelerator is returned and it is determined that the engine has entered the deceleration state, and the routine proceeds to step S29. Whether the remaining count of the timer is zero in step S29, that is, in step S2
5 or step S26, it is determined whether or not 0.3 sec of the predetermined value TIBK has elapsed since the engine deceleration was detected. If the answer is affirmative (YES), that is, if 0.3 sec has elapsed, the flag FISTP = 0 is set in step S28, and the sleep mode is not established.

The answer to step S29 is negative (NO).
If 0.3 sec has not elapsed, it is determined in step S30 whether or not the brake switch 119 is turned on. If the answer is (NO), the engine is determined in steps S31 and S32. Determine the degree of decrease in the number of rotations. In step S31, it is determined whether or not the current value NEn of the engine speed is smaller than the previous value NEn-1. If the answer is affirmative (YES), that is, if the engine speed is decelerated, the process proceeds to step S32. In step S32, it is determined whether or not the degree of decrease ΔNE in engine speed is larger than a predetermined value ΔNE1. If the answer to step S32 is negative (NO), step S3
3, the flag FISTP = 1 is set, and the sleep mode of step S11 shown in FIG. 3 is established. Further, the answer is affirmative in the determination processing of steps S30 and S31 (Y
ES), flag FIS in step S28
TP = 0 is set to prohibit establishment of the sleep mode. this is,
If the brake is stepped on or the engine speed is rapidly decreased during the period from when the engine deceleration is detected to when 0.3 sec of the predetermined value TIBK has elapsed, the engine is stopped when the rest mode is established. Therefore, the discrimination processing of steps S30 and S31 prevents it.

In the above FISTP discrimination processing, when it is detected that the driver has decelerated the engine by returning the accelerator petal while the vehicle is traveling at high speed in a low pressure area at high speed, for example, 0 is detected after the deceleration is detected. E for only 3 seconds
Put the ACV in sleep mode. As a result, the valve body 108b of the AIC control valve 108 is fully closed, and the intake pipe 102
The auxiliary air that flows into is shut off. Therefore, the intake pipe 2
Since the value of the negative pressure in the inside increases and the negative pressure in the negative pressure chamber 2 in the brake booster 1 also increases, a necessary differential pressure between the negative pressure chamber 2 and the atmospheric chamber 3 can be obtained even when traveling in a high altitude. Therefore, the boosting characteristic of the brake booster 1 can be favorably maintained.

Further, the air conditioner switch may be turned off during deceleration under low atmospheric pressure. As a result, the amount of auxiliary air is further reduced, and the negative pressure in the intake pipe 2 can be increased.

[0050]

As described above, according to the present invention, the deceleration detecting means for detecting that the internal combustion engine is in the decelerating state, and the valve means for adjusting the amount of the auxiliary air supplied to the engine. In the deceleration intake air amount control device for an internal combustion engine, comprising: a valve control unit that controls the valve unit to supply auxiliary air during the deceleration state, an atmospheric pressure detection unit that detects atmospheric pressure, and the atmospheric pressure are The negative pressure chamber of the brake booster is communicated with the intake side of the engine because the air prohibiting means is provided to control the valve means to shut off the supply of the auxiliary air to the engine when the value is lower than the predetermined value. In this case, the negative pressure of the negative pressure chamber is increased, and a necessary differential pressure between the atmospheric pressure chamber and the negative pressure chamber of the brake booster is sufficiently obtained.
As a result, even if the vehicle is traveling in a high place of low pressure, the brake boosting effect of the brake booster can be sufficiently exerted.

Further, when the brake switch is turned on within the predetermined time period or when the degree of decrease in the number of revolutions of the engine becomes larger than a predetermined value, the interruption of the supply of the auxiliary air by the auxiliary air supply prohibiting means is released. Since the prohibition releasing means is provided, the engine stall can be prevented.

Further, when the present invention is applied to a multiple throttle type engine, the above-mentioned effect of the brake booster becomes more remarkable.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of a deceleration intake air amount control device according to the present invention.

FIG. 2 is a flowchart of a main routine of EACV processing in this embodiment.

FIG. 3 is a flowchart of a main routine of EACV processing in this embodiment.

FIG. 4 is a diagram showing a table of valve opening correction values IDEC.

FIG. 5 is a flowchart of flag FISTP determination processing in the EACV processing.

FIG. 6 is a flowchart of flag FISTP determination processing in the EACV processing.

FIG. 7 is a schematic configuration diagram of a brake booster.

FIG. 8 is a diagram showing an example of a boosting characteristic of a brake booster.

FIG. 9 is a diagram showing a configuration example of a single-bore throttle type intake pipe.

FIG. 10 is a diagram showing an example of a negative pressure waveform of an intake pipe in a single bore throttle system.

FIG. 11 is a diagram showing a schematic configuration example of an intake pipe of a triple throttle system.

FIG. 12 is a diagram showing a negative pressure waveform of an intake pipe in a triple throttle system.

FIG. 13 is a diagram showing the difference in the negative pressure values obtained in the intake pipes of the single bore throttle system and the multiple throttle system together with the fluctuation of the atmospheric pressure.

[Explanation of symbols]

1 brake booster 100 engine 102 intake pipe 104-106 throttle valve 107 auxiliary air passage 108 AIC control valve (valve means) 120 atmospheric pressure sensor (atmospheric pressure detection means) 109 ECU (deceleration detection means, control means, auxiliary air supply prohibition means) , First and second prohibition releasing means)

Claims (4)

[Claims] 1. A deceleration detecting means for detecting that an internal combustion engine is in a decelerating state, a valve means for adjusting an amount of auxiliary air supplied to the engine, and a valve means for controlling the valve means when the decelerating state is detected. In a deceleration intake air amount control device for an internal combustion engine, comprising: a control unit for supplying auxiliary air by means of: an atmospheric pressure detecting unit for detecting atmospheric pressure; and controlling the control unit when the atmospheric pressure is lower than a predetermined value. And an auxiliary air supply prohibiting means for interrupting the supply of auxiliary air from the valve means to the engine. 2. The deceleration of the internal combustion engine according to claim 1, wherein the auxiliary air supply prohibiting means cuts off the supply of the auxiliary air for a predetermined time after the deceleration state of the engine is detected. Intake air amount control device. 3. When the brake switch is turned on within the predetermined time or when the degree of decrease in the engine speed becomes larger than a predetermined value, the interruption of the auxiliary air supply by the auxiliary air supply prohibiting means is released. 3. The deceleration intake air amount control device for an internal combustion engine according to claim 1, further comprising a prohibition canceling means. 4. The deceleration intake air amount control device for an internal combustion engine according to claim 1, wherein the engine is a multiple throttle system.