Vehicle drive force control device

Abstract

The object of the present invention is to prevent the retardation of the ignition timing or the reduction of the fuel supply amount from being performed for a long time when it is necessary to reduce the driving force of the vehicle, and to avoid The temperature rise of the exhaust gas and the resulting deterioration of the exhaust gas purification catalyst and effectively reduce the driving force of the vehicle. When the driving force of the vehicle is too large, the target driving force Fxt is calculated, and when the index value SAa indicating the necessary degree of driving force reduction is greater than or equal to the first reference value SAa1, the throttle opening is reduced so that the driving force of the vehicle is lower than the target value. The driving force Fxt decreases steadily, and when the index value SAa is greater than or equal to the second reference value SAa2 that is greater than the first reference value SAa1, the ignition timing is retarded in addition to reducing the throttle opening, so that the driving force of the vehicle Descent more quickly than just lowering the throttle opening.

Description

technical field [0001] The present invention relates to a driving force control device for a vehicle, and more specifically relates to a driving force control device for controlling the driving force of a vehicle by controlling the throttle opening of an engine and controlling the ignition timing. Background technique [0002] In a vehicle such as an automobile equipped with a spark ignition engine, as one of the driving force control devices that control the driving force of the vehicle by controlling the throttle opening of the engine and the ignition timing, a drive with the following configuration is known: Force control device, that is, when the driving slip of the driving wheels increases, the output of the engine is reduced through the full closing control of the throttle valve and the delay control of the ignition timing, thereby reducing the driving force of the vehicle. When the shift is lowered, the delay control of the ignition timing is ended first, and then the...

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Problems solved by technology

However, the full-close control of the throttle valve cannot reduce the output of the engine with good responsiveness, so the driving force of the vehicle cannot be reduced with good responsiveness.

[0005] In this way, in the driving force control device described in the above-mentioned Japanese Patent Publication No. 7-84850, the execution time of the delay control of the ignition timing is not considered, so it may cause the temperature of the exhaust gas of the engine to rise and the resulting Deterioration of the exhaust gas purification catalyst has led to the problem that the driving force control device described in the above-mentioned Japanese Patent Publication No. 7-84850 cannot satisfy the stringent exhaust gas regulation standards in recent years.

[0006] In addition, Japanese Patent Laid-Open No. 10-264801 discloses a driving force control device in which the execution time of delay control of ignition timing is limited.

However, the delay control of the ignition timing is limited to a fixed time from the moment when the engine output is reduced by the reduction control of the throttle opening. Therefore, in all driving conditions of the vehicle, in order to prevent There is a problem that the effect of reducing the driving force of the vehicle by the delay control of the ignition timing is also limited

For example, when driving slip of the drive wheels occurs immediately after the vehicle starts, the throttle opening reduction control and ignition timing retardation control are started to deal with this situation, and the ignition timing is stopped when a certain time has elapsed. If the delay control is used, then even if the driving slip of the drive wheels continues to occur, the delay control of the ignition timing cannot be performed, so that the drive slip cannot be effectively reduced by reducing the engine output through the delay control of the ignition timing.

[0007] Also, even by reducing the amount of fuel supplied to the engine, the output of the engine can be reduced more responsively than the throttle opening reduction control, as in the case of retardation control of the ignition timing, but once the amount of fuel supplied to the engine is reduced, The amount of fuel supplied, as in the case of delay control of the ignition timing, will cause the temperature rise of the exhaust gas of the engine and the deterioration of the exhaust gas purification catalyst caused by this, so the execution time of the reduction of the fuel supply amount must also be limited to an extremely short time. time

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