Method of and apparatus for reducing vibrations of car body

Claim 2

Method according to claim 1, characterized by detecting the engine angular velocity and its changes for determining the occurrence of roughness.

Claim 3

Method according to claim 2, characterized in that the temporarily exerted external force is the force of reaction caused by a rapid increase in torque generated by a rotary machine mounted on the engine (11) so that the rotating axis of the rotary machine is in parallel to the rolling axis of the engine (11).

Claim 4

Method according to claim 3, characterized in that the rotary machine is an alternator (10) and the alternator (10) is controlled so as to increase the output torque thereof in a pulse-like form.

Claim 5

Method according to claim 3, characterized in that the rotary machine is an alternator (10) which is controlled so as to satisfy the quantity of the rapid increase in torque and timing of the torque increase which are determined according to the degree of roughness and the angular velocity of the engine immediately before the occurrence of the roughness.

Claim 6

Method according to claim 2, characterized in that the roughness is detected during idling of the engine (11) and the exerting of the external force comprises the steps of: setting the output of an electric machine driven by the engine as a controlled variable determined on the basis of a degree of roughness and an angular velocity of the engine to be suitable for reducing the vibrations of the engine (11) caused by the roughness, determining upon the detection of the occurrence of roughness, an optimum output to reduce the vibrations of the engine (11) caused by the roughness in accordance with a degree of the occurred roughness and the angular velocity detected immediately before the occurrence of the roughness, and controlling the electric machine to increase temporarily the output thereof with a timing after the occurrence of the roughness so that the output reaches the optimum value whereby the vibrations of the engine (11) and the car body is reduced.

Claim 7

Method according to claim 2, characterized in that the roughness is detected during idling of the engine (11) and the exerting of the external force comprises the steps of: setting an increased output of an electric machine driven by the engine (11) and timing this increase on the basis of the degree of roughness and the angular velocity, determining an optimum increase in the output of the engine (11) and an optimum timing of the output increase in accordance with the detected degree of roughness and the angular velocity detected immediately before the occurrence of the roughness, and controlling the electric machine to increase temporarily the output thereof with the optimum timing so as to reach the optimum output, whereby vibrations of the engine (11) and the car body caused by roughness are reduced.

Claim 8

Method according to claim 7, characterized in that the electric machine consists of an automobile battery charging alternator (10), a field current in the alternator (10) is controlled so that the alternator (10) output is the optimum torque.

Claim 9

Method according to claim 8, characterized in that the torque is varied by varying the pulse width of an electric signal applied to the alternator (10).

Claim 10

Method according to claim 9, characterized in that a variable control pulse is applied to the alternator (10) so as to suppress the vibration of the engine (11) ascribed to the occurrence of roughness is set so that the center of the pulse width is positioned at 1/2 of the cycle of natural frequency of rolling vibrations of the engine (11).

Claim 11

Method according to claim 10, characterized in that the alternator (10) is controlled so as to reach the optimum output in the range of 1/4-3/4 cycles of the natural frequency value of rolling vibration of the engine (11) which are ascribed to roughness.

Claim 12

Method according to claim 11, characterized in that the torque is made variable by varying a boosting voltage of an electric signal applied to the alternator (10).

Claim 13

Method according to claim 12, characterized in that the detection of roughness is made by taking in detected data on the angular velocity of the engine (11) at every crank angle of 720°/n, wherein n is the number of cylinders in the engine, and by determining a difference between a detected value of the angular velocity of the engine currently taken and that of the angular velocity of the engine taken in a preceding time.

Claim 14

Method according to claim 12, characterized in that the detection of roughness is performed by determining a difference α between a peak value N TOP of rotational speed of the engine (11) and a peak value N BOT where the rotational speed decreases, which appear at every crank angle of 720°/n, wherein n is the number of cylinders in the engine (11), or a difference Δα(2) between a current difference α(2) and the preceding difference α(1).

Claim 15

Method according to claim 7, characterized in that the detection of roughness is performed by determining the vibration acceleration in the direction of the rolling occurring in the engine (11).

Claim 16

Method according to claim 15, characterized in that after the torque of the electric machine is increased when roughness is detected, while the influence of the torque control operation appears as a decrease in the angular velocity of the engine (11), the updating only of the detected data on the angular velocity of the engine is made without carrying out the detection of roughness again.

Claim 17

Apparatus for reducing vibrations of a car body (13) of an automobile having an internal combustion engine (11) comprising means (10, 113, 112, 120) for exerting an external force to the engine block of the engine (11) in a direction to cancel the engine roll vibrations caused by the roughness, characterized in that means (1, 2, 6, 7, 8) are provided for detecting the occurrence of roughness caused by irregular combustion of the engine (11) at idling speed and the means for exerting an external force (10, 113, 112, 120) temporarily exert the external force in a time range of about 1/2 cycle of the natural frequency of the roll vibration of the engine (11) after the top dead center (TDC) around which roughness is detected.

Claim 18

Apparatus according to claim 17, characterized in that the means (1, 2, 6, 7, 8) for detecting the occurrence of roughness comprises a crank angle sensor (6) mounted on the engine (11) to output angular velocity signals and means (1) monitoring the detected angular velocity and determining the occurrence of roughness from a change in the detected angular velocity, and the means (10, 112, 113, 120) for exerting force comprises a rotary machine (10) secured to the engine (11) and a control means (112, 113) for controlling the rotary machine so as to provide a rapid increase in output torque temporarily at an appropriate time after the occurrence of roughness.

Claim 19

Apparatus according to claim 17, characterized in that the means (1, 2, 6, 7, 8) for detecting the occurrence of roughness detects roughness on the basis of change in operation condition of an engine (11) during idling thereof, and the means for exerting a force comprises: means (1, 6) for detecting the angular velocity of the engine (11), means (4, 5) for storing the torque values of an electric machine (10), which are engine loads, as control variables suitable for suppressing the vibration of the engine (11) ascribed to the occurrence of roughness in a data map or in the form of a calculation formula on the basis of the relation between the degree of roughness and the number of revolutions of the engine, means (3) for determining, when roughness is detected, an optimum torque corresponding to an actual detected value of the roughness and a value detected immediately before the occurrence of the roughness of the angular velocity of the engine (11) on the basis of the retrieval of the data map or on the basis of the calculation formula, and means (9) for controlling a value of voltage applied to the electric machine (10) or the pulse width thereof according to a retrieved or calculated torque.

Claim 20

Apparatus according to claim 17, characterized in that the means (1, 2, 6, 7, 8) for detecting the occurrence of roughness detects roughness on the basis of change in operating condition of an engine (11) during the idling thereof and the means (10, 112, 113, 120) for exerting force comprises: means (3, 7, 8) for detecting the number of revolutions of the engine, means (4, 5) for storing the torque values of an electric machine (10), which are engine loads, as control variables suitable for suppressing the vibration of the engine (11) ascribed to the occurrence of roughness, and a timing at which an electric signal concerning this control operation is applied to the electric machine (10), as variable timing, in a data map for retrieval or in the form of a calculation formula from the relation between the degree of roughness and the angular velocity of the engine (11); means (3) for determing, when roughness is detected, an optimum torque value and the timing thereof corresponding to a detected value of the roughness and a value, detected immediately before the occurrence of the roughness, of angular velocity of the engine (11), on the basis of the retrieval of the data map or on the basis of the calculation formula, and means (9) for variably controlling a value of voltage applied or calculated to the electric machine (10) on the basis of a retrieved control variable of torque and the timing, or the pulse width thereof.