JPH03225077A - Longitudinal vibration reducing method and device for automobile body - Google Patents

Abstract

PURPOSE:To reduce the longitudinal vibration of a body by providing an automobile body with longitudinal vibration reducing device with sensors for detecting throttle opening speed, engine speed variation, and the like, as well as with a means for foreseeing the generation of body longitudinal vibration. CONSTITUTION:In an automobile body longitudinal vibration reducing device, the value inputted from a sensor 1 for detecting the throttle opening speed, a sensor 2 for detecting the throttle opening speed, a sensor 2 for detecting engine speed variation, a sensor 3 for detecting the speed change stages of a hand-operated transmission, and the like is compared with the preset value to foresee the generation of the longitudinal vibration of a body by a foreseeing means 4, and a command is outputted to an output means 6. After the sudden acceleration of an engine upon receiving this command, the output means 6 delays the ignition timing of the engine during the time corresponding at least two initial peaks of the engine speed variation. As the result, the engine speed variation, driving torque variation and the longitudinal vibration of the body can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method and apparatus for reducing longitudinal vibration of a vehicle body in an automobile equipped with a four-stroke engine.

In a car, when the accelerator is suddenly operated for acceleration while driving at low speed due to traffic congestion, etc., the car body vibrates in the longitudinal direction, giving the occupants a jerky feeling four to five times.

This vibration is called shakuri vibration, and its vibration period is low at about 3 to 5 Hz, which is the same as the primary frequency of engine rotational speed fluctuations and drive system torsional vibration, and its vibration waveform is similar to engine rotational speed fluctuation i waveform and drive system. It is similar to the torque fluctuation waveform.

When this jerky vibration occurs, it impairs the smooth acceleration and ride comfort of the vehicle.

Attempts were made to improve the engine mount to address this problem, but these improvements to the power transmission system did not produce sufficient results.

(Means for Solving the Problems) The present invention was invented to solve the above problems, and the gist of the first invention is that the front and rear G aJ+ of the vehicle body is increased by rapid acceleration of the 4-cycle engine. A method for reducing longitudinal vibration of an automobile body, which is characterized by delaying the ignition time of the engine during a period corresponding to at least two initial peaks of its rotational speed fluctuation after a sudden acceleration of the engine, when predicted. In automobiles, a sensor that detects the opening speed of the throttle is used to compare values input from each of the above sensors with a value preset in a storage means, and a value that predicts the occurrence of longitudinal vibration of the vehicle body is compared. It is characterized by comprising an output means for outputting a signal for delaying the ignition time of the engine at at least two peaks at the beginning of the rotational speed fluctuation after sudden acceleration of the engine when receiving a command for longitudinal vibration of the vehicle body. This is a longitudinal vibration reduction device for automatic BI car bodies.

(Function) Since the present invention has the above configuration, the above 1 &
When vibration is predicted, the ignition timing of the engine is delayed at at least two peaks at the beginning of the rotational speed fluctuation after the engine is suddenly accelerated, and the engine output is reduced to reduce the engine rotational speed fluctuation and drive torque. Reduces fluctuations and longitudinal vibration of the vehicle body.

(Example) Hereinafter, one example of the present invention will be specifically described with reference to the drawings.

FIG. 1 shows a control block diagram, and FIG. 2 shows a flowchart.

The sensor 11 which detects the opening speed of the throttle is input to the jerk vibration prediction means 4, where it is compared with the value input from the storage means 5.

The gear position S is set to 2nd speed, the throttle opening speed TH is equal to or higher than the set value A, and the engine rotational speed change ΔNe
When is equal to or higher than the set value 8, the prediction means 4 predicts the chipping vibration and outputs a command to the tensioning means 6. When the I-force means 6 receives this command, the sensor I
After rapid acceleration of the engine in accordance with the output of the sensor 2, a signal is output to the ignition pulse generator 7 for delaying the ignition timing of the engine during a period corresponding to at least two peaks of engine speed fluctuation.

In automobiles equipped with automatic transmissions, fluctuations in engine speed are absorbed by the automatic transmission, so no jerking vibrations occur.

In addition, when the gear position of a manual transmission is determined, the frequency of torsional vibration is determined accordingly. Therefore, when a series of gear positions are set, the primary frequency of torsional vibration is higher than the frequency of the shakuri vibration of the vehicle body. In addition, when the gear position of the manual transmission is set to third speed or higher, the primary frequency of torsional vibration is higher than the frequency of hiccup vibration, so no hiccup vibration occurs in either case.

When the throttle opening speed Tll is less than or equal to A, that is, when the accelerator is depressed slowly, no jerking vibration occurs.

When the change in engine speed ΔNe is 8 or more, the fluctuation in torsional vibration is small, so no hiccup vibration occurs.

In addition, when the engine suddenly accelerates, shakuri vibration appears as a transient phenomenon based on vibrations in the drive shaft torque due to fluctuations in engine speed, so the engine must generate a torque with the same period and opposite phase as the torque vibration during this period. If so, this can be reduced.

However, since it is not possible to further increase the engine torque when the engine speed decreases, the engine torque is reduced by delaying the engine ignition timing when the engine speed is at its peak. at least two peaks of MIIIlal
e, A, c, 2 Vehicle body longitudinal vibration, drive shaft torque, engine rotation speed, cylinder effective pressure (engine (which can be equated with output), and temporal changes in ignition timing are shown, with the solid line showing the one according to the present invention and the broken line showing the conventional one.

As is clear from Figure 3, when the throttle opening is rapidly increased, the cylinder effective pressure increases rapidly, and the engine speed, drive shaft torque, and body longitudinal vibration remain the same, although there is a slight phase lag. Varies with frequency. Therefore, if the ignition timing is delayed by about 17deg during the period corresponding to at least two peaks of the initial engine rotational speed fluctuation after the sudden increase in throttle opening, that is, after sudden engine acceleration, the in-cylinder effective The pressure decreases and forms two valleys,
i'i? The after-vibrations are respectively lower than in the conventional case, that is, in the case where the ignition timing is not retarded.

(Effects of the Invention) In the present invention, when longitudinal vibration of the vehicle body is predicted due to sudden acceleration of the engine, the ignition timing of the engine is determined during the period corresponding to at least two peaks at the beginning of the rotational speed fluctuation after the sudden acceleration of the engine. This delay effectively reduces the longitudinal vibration of the vehicle body, resulting in the smooth acceleration and ride comfort of an automatic vehicle.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 show a first embodiment of the present invention.
The figure is a control block diagram, and FIG. 2 is a flowchart. Figure 3 shows longitudinal vibration of the vehicle body, drive shaft torque, engine rotational speed, dynamic pressure in the cylinder, temporal changes in 1 knot opening and ignition timing during sudden engine acceleration in the present invention and the conventional engine. 1 Figure 2 Guan Figure 3 Zhaokai CC

Claims (2)

[Claims] (1) When longitudinal vibration of the vehicle body is predicted due to sudden acceleration of a 4-cycle engine, the ignition timing of the engine is delayed for a period of time corresponding to at least two peaks at the beginning of the rotational speed fluctuation after the sudden acceleration of the engine. A method for reducing longitudinal vibration of an automobile body, characterized by: (2) In an automobile that transmits the output of a four-cycle engine mounted on the vehicle body to the wheels via a manual transmission, a sensor that detects throttle opening speed, a sensor that detects fluctuations in engine speed, and the manual transmission a sensor for detecting the gear position of the vehicle, a prediction means for predicting the occurrence of longitudinal vibration of the vehicle body by comparing the values inputted from each of the above-mentioned sensors with a value preset in the storage means, and a command from the prediction means. and output means for outputting a signal for delaying the ignition timing of the engine at at least two peaks at the beginning of the rotational speed fluctuation after sudden acceleration of the engine when the engine is suddenly accelerated. Device.