JPH04140436A - Intake air quantity controller of engine - Google Patents

Abstract

PURPOSE:To improve startability while securing acceleratability by setting opening characteristic of a throttle valve to nonlinear characteristic by which throttle valve opening becomes lower than the acceleration opening, while interposing a control valve which adjusts a bypass air quantity at the time of idling in a bypass air passage of the throttle valve. CONSTITUTION:A control valve 16 is interposed in a bypass air passage 15 which connects to upper and lower parts of the intake passage 8 by bypassing a throttle valve 12. An ignition plug 17 is arranged facing to a combustion chamber 3, and discharge voltage is applied to the plug via an ignition coil 18 and a distributor 19. A control signal is outputted from a controller 20 in the control valve 16, and control of an intake air quantity is performed during the idling time or the like. An ignition signal is outputted also to the ignition coil 18. In the case, opening of the control valve 16 is increasingly compensated so as to increase intake air quantity in an engine rotational speed range on the lower rotation speed side than that in the vicinity of the stall rotational speed where driving force of the vehicle for increasing engine rotational speed starts to be transferred to vehicle wheels via an automatic transmission provided with a torque converter.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an engine intake air amount control device that sets the throttle opening characteristic to be non-linear and also supplies bypass air by bypassing the throttle valve. It is something.

(Prior Art) Conventionally, the opening characteristic of an engine throttle valve, that is, the change in throttle opening with respect to the amount of accelerator operation (accelerator opening), has been set in response to various demands, and generally, The throttle opening increases linearly with the accelerator opening, but in order to improve acceleration, the throttle opening is increased relative to the accelerator opening at low throttle openings. In addition, there is a known technique in which the relationship between the accelerator opening and the throttle opening is set to a nonlinear characteristic that does not change linearly (for example,
(See Japanese Patent Publication No. 52-39978).

In addition, in a throttle valve with a relatively large diameter, most of the intake air amount control, that is, changes in torque characteristics, are performed in the low throttle region, and in the region above a certain opening degree, there is no torque change corresponding to accelerator operation, and the operation feels In this case, by making the throttle opening characteristic non-linear and making the throttle opening smaller than the accelerator opening as described above, the torque characteristic becomes linear with respect to the accelerator opening. It is conceivable to set the target so that the torque changes at a high throttle opening and ensure operability.

On the other hand, in order to control the idle speed of the engine to a predetermined state, a bypass air passage is provided that bypasses the throttle valve of the intake passage, and the amount of bypass air is adjusted by a control valve installed in this bypass air passage. A technique is also known in which the idle rotation speed is controlled to a target rotation speed.

(Problem to be Solved by the Invention) Therefore, as described above, the throttle opening characteristic is set to be non-linear and the throttle opening is made smaller than the accelerator opening.
If driving performance is improved by obtaining a feeling of acceleration at a high throttle opening, there is a problem in that the starting performance deteriorates when the vehicle is driven through an automatic transmission equipped with a torque converter.

In other words, if the throttle opening is set to a non-linear characteristic in order to obtain a feeling of acceleration at a high throttle opening, the torque at a low throttle opening will become smaller, and as a result, in a vehicle equipped with an automatic transmission, it will be difficult to start. This will reduce the sense of acceleration.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an intake air amount control device for an engine that uses a non-linear characteristic of the throttle opening to improve starting performance while ensuring acceleration performance at a high throttle opening. That is.

(Means for Solving the Problems) In order to achieve the above object, the intake air amount control device of the present invention changes the throttle valve opening characteristic to a nonlinear characteristic in which the throttle valve opening is lower than the accelerator opening. On the other hand, a bypass air passage is provided to bypass the throttle valve and supply bypass air, and a control valve is interposed in the bypass air passage to adjust the amount of bypass air during idling. Increase the opening degree of the control valve of the bypass air passage in an engine rotation region lower than near the stall rotation speed, where the driving force of the vehicle for upward movement begins to be transmitted to the wheels via an automatic transmission equipped with a torque converter. This configuration includes a control means for increasing the amount of intake air.

(Functions and Effects) In the engine intake air amount control device as described above, the throttle valve opening characteristic is set to a non-linear characteristic that is lower than the accelerator opening, so that accelerator operation in the high throttle opening range is controlled. It is possible to secure torque change characteristics corresponding to the engine speed and obtain acceleration driving performance due to the increase in torque, such as when the engine is fully opened at low speeds. In addition, due to this non-linear characteristic, the torque in the low throttle region tends to decrease and the starting performance deteriorates.
By correcting the amount of throttle bypass air using the bypass air control valve and increasing the amount of bypass air on the low rotation side near the stall rotation speed, the amount of intake air in the region where driving force is transmitted to the wheels when starting is reduced. By increasing the torque, the starting performance can be improved by increasing the torque, and both the running performance at a high throttle opening and the starting performance at a low throttle opening can be improved.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall configuration diagram of an engine equipped with an intake air amount control device according to an embodiment.

An intake boat 4 and an exhaust boat 5 communicate with a combustion chamber 3 formed above the piston 2 of the engine body 1 with a variable volume, and the openings are opened and closed at predetermined timings by an intake valve 6 and an exhaust valve 7. be done.

The intake passage 8 connected to the intake boat 4 is provided with an air flow sensor 11 that detects the amount of intake air from the upstream side, and a throttle valve 12, and the downstream portion of the surge tank 13 is branched into each cylinder. An injector 14 is disposed to inject and supply fuel to the engine.

Further, a bypass air passage 15 is formed in the intake passage 8, which bypasses the throttle valve 12 and connects to the intake passage 8 above and below the intake passage 8, and the amount of bypass air can be controlled by adjusting the opening degree of the bypass air passage 15. A control valve 16 for adjustment is interposed. Further, an ignition plug 17 is disposed facing the combustion chamber 3, and a discharge voltage is applied to the ignition plug 17 via an ignition coil 18 and a distributor 19.

A control signal is output from the controller 20 to the control valve 16 of the bypass air passage 15 to control the amount of intake air during idling and other areas.

An ignition signal is also output to the ignition coil 18.

The controller 20 receives signals from various sensors, and in bypass air control, it receives a throttle opening signal T including an engine speed signal R5 and an idle signal.
V, external load signal, etc. are manually input.

Further, as shown in FIG. 3, the opening characteristic of the throttle valve 12 is set to be a nonlinear characteristic such that the throttle opening TV is lower than the accelerator opening. In other words, when the accelerator opening is fully closed, the throttle opening is also fully closed.
The throttle opening is linked so that when the accelerator opening is fully open, the throttle opening is also fully open, but at intermediate openings, the throttle opening is smaller than the accelerator opening, for example, when the accelerator opening is 1/2. Throttle opening is 1/4
It is set to be about.

The accelerator mechanism and the opening/closing mechanism of the throttle valve 12 may be mechanically linked to obtain the throttle opening characteristics described above, or the throttle opening may be electrically adjusted by detecting the accelerator opening. They may be linked together to control them.

The opening degree control of the bypass air control valve 16 by the controller 20 (control means) is basically based on the throttle valve 12.
During idling when the valve is closed, the amount of bypass air is calculated according to the difference between the two so that the actual idle speed matches the target idle speed depending on the water temperature, etc., and feedback control is performed to a predetermined opening degree. Furthermore, if an external load such as an electrical load or a cooler load is applied during idle, the load is corrected.

Further, when the engine speed is in a region lower than near the stall speed when the engine is not idling, throttle correction is performed with a characteristic set to increase the amount of bypass air in the low throttle opening region. The stall rotational speed is the rotational speed at which the vehicle actually starts to be driven in response to an increase in engine rotational speed at the time of starting in an automatic transmission having a torque converter. In other words, in the case of this automatic transmission, there is slippage in the torque converter even when the accelerator is operated, and the vehicle is not driven immediately even when a starting operation is performed, but after the engine speed has increased to a certain extent, the driving force is lost. This is the engine rotation speed when transmitted to the wheels. and,
The above-mentioned throttle correction is performed in order to increase the amount of intake air for the throttle opening that reaches the stall rotational speed, thereby speeding up the increase in engine rotational speed and improving starting performance. This stall rotation speed varies depending on engine displacement, torque converter characteristics, etc., but for example, 250
It is set to 0rp11.

Next, the processing of the controller 2o will be explained according to the flowchart shown in FIG. This flowchart shows only the bypass air control routine. After the control starts, a throttle opening signal, an engine rotation speed signal, an external load signal (electrical load, cooler load, etc.), etc. are read in step s1. Then, in step s2, it is determined whether or not the throttle opening degree TV is idling below a predetermined value TVa.

If the determination in step S2 is YES and the vehicle is idling, it is determined in step s3 whether or not the vehicle is in a no-load state in which the external load is not operating. In the case of no-load state, the bypass air amount QB is calculated in step S4. The amount of bypass air QB in this idle no-load state is determined by the base flow rate QBst set corresponding to the engine water temperature and the feedback correction amount QBf based on the difference between the target rotation speed and the detected rotation speed.
b.

In addition, if the determination in step S3 is No and in an idling state where an external load is acting, the process proceeds to step S5 and the load correction amount QBd is determined according to the magnitude of the external load that is operating.
+ is read, and the bypass air amount QB in this state is calculated in step S6. The amount of bypass air QB in this case is
The base flow rate QBst and the feedback correction amount QB
It is calculated by adding the load correction amount QBdl to fb.

Next, if the determination in step S2 is No, the throttle opening T
During off-idle when V is opened to the idle opening degree TVa or more, the process proceeds to step S7, where it is determined whether the engine rotation speed R is a low rotation speed below a set value Rst corresponding to the stall rotation speed. This set value Rst is set to a predetermined value (for example, 500 rpm) to the stall rotation speed (for example, 25 (tOrpg)).
It is set to the added rotation speed.

If the determination in step S7 is NO, the set value Rst
When the rotation speed exceeds 1, the amount of bypass air QB in this state is calculated in step S8. Bypass air amount QB in this case
is set only by the base flow rate QBst.

Further, if the determination in step S7 is YES, the set value Rst
During the following low rotation, the throttle/sotol correction amount QBtv corresponding to the throttle opening is read in step S9, and the bypass air amount QB in this state is calculated in step SIO.

The bypass air amount QB in this case is the base flow rate QB
It is set by adding st and throttle correction amount QBtv.

As shown in FIG. 4, the throttle correction amount QBtv is set in the low throttle/sottle opening range with respect to the throttle opening, and is used to increase the starting range as described above.

As mentioned above, step S4. S6. S8 and Sl[+
Based on the bypass air amount QB set in step 511, the control valve 16 is driven to the opening degree corresponding to the bypass air amount QB.

According to the embodiment described above, the relationship between the accelerator opening TV and the intake air amount Qa is determined by the throttle opening characteristic shown in FIG. 3 and the base flow rate QB of the bino square control, as shown in FIG. The basic flow rate is such that the intake air amount Qa increases linearly as the accelerator opening increases, and the throttle correction amount Qa increases in the low opening accelerator region, which is the starting region.
This increases the amount of intake air corresponding to Btv.

In other words, the throttle opening characteristic shown in FIG. It is designed to give a feeling of acceleration depending on the opening degree.

In the above embodiment, the bypass air increase correction for improving starting performance is performed by setting the throttle correction amount according to the throttle opening, but it is also set according to the accelerator opening. Alternatively, the table may be set in stages.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an engine equipped with an intake air amount control device in one embodiment, Fig. 2 is a flowchart showing a bypass air control routine, Fig. 3 is a characteristic diagram showing throttle opening characteristics, and Fig. 4 is a diagram showing a flowchart showing a bypass air control routine. The figure is a characteristic diagram showing an example of setting the throttle correction amount, and FIG. 5 is a characteristic diagram showing the relationship between the accelerator opening and the intake air amount. 1...Engine body, 8...Intake passage, 12...Throttle valve, 15...Bypass air passage, 16...Control valve , 20...
...Controller (control means).

Claims (1)

[Claims] (1) The opening characteristic of the throttle valve in the intake passage is set to a nonlinear characteristic in which the throttle valve opening is lower than the accelerator opening, while the bypass air passage bypasses the throttle valve and supplies bypass air. An intake air amount control device for an engine, comprising: a control valve for adjusting an amount of bypass air during idling in the bypass air passage;
The bypass air passage control valve is opened in an engine rotation region lower than near the stall rotation speed, where the vehicle's driving force in response to an increase in engine speed begins to be transmitted to the wheels via an automatic transmission equipped with a torque converter. 1. An intake air amount control device for an engine, comprising a control means for increasing the intake air amount by increasing the intake air amount.