JPH1144231A - Torque fluctuation control device - Google Patents

Abstract

(57) [Problem] To reduce a torque fluctuation caused by a combustion pressure fluctuation of an internal combustion engine such as an automobile engine and an engine roll vibration accompanying the torque fluctuation. SOLUTION: In an internal combustion engine such as an automobile engine having a main flywheel 3 on a rotating shaft, means for detecting or estimating a fluctuating torque generated by the internal combustion engine, and a reverse direction having a fixed ratio to a rotation speed of the internal combustion engine. And a control means for controlling the torque generated by the sub flywheel 4 in accordance with the fluctuation torque. The control means changes the torque generated by the sub flywheel 3. Thereby reduce the fluctuation torque.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque fluctuation control device for reducing a torque fluctuation caused by a combustion pressure fluctuation of an internal combustion engine such as an automobile engine, and an engine roll vibration caused thereby.

[0002]

2. Description of the Related Art Conventionally, as this kind of torque fluctuation control device, one described in Japanese Patent Application Laid-Open No. 6-42591 is known. As shown in FIG. 4, it has a main flywheel 3 and a sub flywheel 4 which rotates in the opposite direction. The roll moment of the engine is generated by the roll moment generated by the reaction force acting on the bearings of the two flywheels. This is to cancel the vibration.

[0003]

However, in the above-mentioned prior art, the conditions for completely canceling the engine roll vibration are as follows: I ₁ = ρI ₂ (1) where I _{1 is} the inertial mass of the main flywheel I ₂ : Inertial mass of sub flywheel ρ: Speed increase ratio In the vicinity of this condition, a large roll vibration reduction effect can be obtained, but in order not to sacrifice the acceleration performance, the main flywheel represented by formula (2) equivalent inertia mass I ₀ the combined sub flywheel is necessary not to change significantly in the case of primary flywheel only. I ₀ = I ₁ + ρ ² I ₂ (2) For this purpose, the relationship between the inertial masses of the main flywheel and the sub flywheel must be set in the hatched area in FIG. Is much smaller. However, since the flywheel also has a role as a friction surface of the clutch, its diameter cannot be reduced so much.In order to reduce the inertial mass, it is necessary to reduce the plate thickness or change to a material with low density. It was necessary to take countermeasures, and there was a problem that the strength was insufficient and the maximum rotation speed of the engine had to be reduced.

[0004] Further, in the above-mentioned prior art, although an effect is obtained with respect to engine roll vibration, there is a problem that torque fluctuation of an engine output shaft cannot be reduced unless the equivalent inertial mass is changed.

[0005] The present invention has been made in view of the above problems, and can maintain a large inertial mass of the main flywheel without changing the equivalent inertial mass of the main flywheel and the sub flywheel. An object of the present invention is to provide a torque fluctuation control device capable of sufficiently maintaining the strength of a wheel and simultaneously reducing a torque fluctuation of an engine output shaft.

[0006]

To achieve the above object, according to the present invention, there is provided a torque fluctuation control apparatus according to the present invention, wherein a fluctuation torque generated by an internal combustion engine is provided in an internal combustion engine having a main flywheel on a rotating shaft. Means for detecting or estimating, a sub-flywheel rotating in the opposite direction at a fixed ratio to the rotational speed of the internal combustion engine, and control means for controlling the torque generated from the sub-flywheel in accordance with the fluctuating torque. The control means changes the torque generated by the sub flywheel to reduce the fluctuation torque.

According to this, the inertial mass of the main flywheel does not need to be reduced more than necessary without changing the equivalent inertial mass of the main flywheel and the sub flywheel.

In this case, it is preferable that a motor generator having both a power generation mechanism and a drive mechanism is used as the control means.

Further, as described in claim 3, it is preferable that the motor generator doubles as an engine starting device and a power generating device.

In these cases, the product of the inertial mass of the sub flywheel and the ratio of the rotational speed of the internal combustion engine to the rotational speed of the sub flywheel is obtained from the inertial mass of the main flywheel. Is preferably larger than 1/2 of the equivalent inertial mass of the main flywheel and the sub flywheel.

[0011]

According to the present invention, since the inertial mass of the main flywheel can be kept large without changing the equivalent inertial mass of the main flywheel and the sub flywheel, the strength of the main flywheel can be sufficiently increased. Can keep
At the same time, torque fluctuations of the engine output shaft can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a torque fluctuation control device according to the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

(Embodiment 1)

FIG. 1A is a front view of an engine provided with a torque fluctuation control device, and FIG. 1B is a side view thereof.
(C) is an enlarged view showing a motor generator and a flywheel. As shown in FIGS.
A motor generator 2 shown in FIG. 1C is attached to the cylinder engine 1. The motor generator 2 has a sub flywheel 4 which is coaxial with the motor generator 2 and has gears on the outer periphery.
Is mounted on the main flywheel 3, and the sub flywheel 4 of the motor generator 2 is driven by the main flywheel 3.
In the opposite direction, it rotates at a constant rotation speed ratio.

The main flywheel 3 is provided with an engine rotational speed sensor 5 for detecting a rotational angular velocity, and the throttle chamber 6 is provided with a throttle opening sensor 7. Further, since the motor generator 2 can be used for both power generation and driving, one motor generator 2 also serves as a starter and an alternator.

In general, an internal combustion engine such as an automobile engine is
Since the torque is generated by the intermittent explosion of the air-fuel mixture in the cylinder, the generated torque fluctuates in synchronization with the explosion cycle. Therefore, when the torque fluctuation reducing means is not used at all, engine roll vibration as shown in FIG. 2A occurs.

The roll motion of the engine and the rotational motion of the engine output shaft (main flywheel) caused by the torque generated by the explosion and the torque generated by the motor generator 2 are as follows:

(Equation 1) Becomes

From the equation (3), the condition for reducing the roll vibration of the engine to zero by the effect of the sub-flywheel 4 is the same as that of the equation (1). Strength cannot be secured. Therefore, to reduce the inertial mass I ₁ to the extent that the intensity of the main flywheel 3 can be secured. For example, when the speed increase ratio is 2.5 and the equivalent inertial mass is not changed, the coefficient of the equation (3) is

(Equation 2) When I ₁ is determined so as to satisfy I ₁ > 0.64I ₀ , the roll vibration is reduced to a certain extent within this range without significantly impairing the strength of the main flywheel 3 as shown in FIG. The effect is obtained.

The reduced effect is compensated for by generating a torque from the motor generator 2 to cancel the fluctuation. Here, in order to generate a torque that cancels the fluctuation, the fluctuation torque must be detected. In the present embodiment, however, the torque fluctuation of the engine rotation secondary, quaternary, and cubic with respect to the engine rotational speed and the throttle opening is previously determined. Is stored in the memory of the arithmetic unit as a map, and the fluctuating torque is estimated from the engine rotation speed detected by the engine rotation speed sensor 5 and the throttle opening detected by the throttle opening sensor 7.

By doing so, a sufficient effect of reducing the engine roll vibration is obtained as shown in FIG. 2 (c), and the torque fluctuation of the output shaft which cannot be obtained when only the sub flywheel 4 is used is obtained. The effect is obtained. Also, since there is no need to make the main flywheel 3 smaller than necessary,
The strength can be sufficiently ensured, and a small motor generator 2 can be used because it is used as an auxiliary role. Also, since the motor generator 2 can also function as a starter and an alternator,
They become unnecessary and the number of parts can be reduced.

(Embodiment 2)

FIG. 3A is a front view of an engine provided with the torque fluctuation control device, and FIG. 3B is a side view thereof.
(C) is an enlarged view showing a motor generator and a flywheel. As shown in the figure, this embodiment uses a belt drive as a drive mechanism of the motor generator 2 of the first embodiment. That is, a pulley 10 of the motor generator 2 is pulled from a crank pulley 8 attached to a crankshaft to a surface opposite to a surface in contact with the crank pulley 8 via an idler pulley 11 using a belt 9 having V-ribs formed on both surfaces. , The motor generator 2 is rotated in a direction opposite to the engine rotation.

In this manner, the use of the belt 9 having lower noise than the gears can reduce noise.

As a means for detecting torque fluctuation, a signal from a rotational angular velocity sensor 5 attached to the main flywheel is converted into a rotational angular velocity through a differentiation circuit, and the torque is calculated by multiplying the angular velocity by an inertial mass. Thereby, control closer to the actual torque fluctuation can be performed. Further, an effect can be obtained even for higher-order torque fluctuations that cannot be obtained in the first embodiment.

[Brief description of the drawings]

FIG. 1A is a front view, FIG. 1B is a side view of an engine including a torque fluctuation control device according to a first embodiment of the present invention,
(C) It is a principal part enlarged view.

FIG. 2 (a) is a roll vibration of a conventional engine, and (b)
6 is a graph showing engine roll vibration when the sub flywheel according to the first embodiment is used, and (c) is a graph showing engine roll vibration when the sub flywheel and the motor generator according to the first embodiment are used.

FIG. 3A is a front view, FIG. 3B is a side view of an engine including a torque fluctuation control device according to a second embodiment of the present invention,
(C) It is a principal part enlarged view.

FIG. 4 is a diagram illustrating a torque fluctuation reduction mechanism of an internal combustion engine according to a conventional technique.

FIG. 5 is a graph showing the relationship between the inertial masses of the main and sub flywheels of the conventional torque fluctuation reduction mechanism.

[Explanation of symbols]

 Reference Signs List 1 engine 2 motor generator 3 main flywheel 4 sub flywheel 5 engine rotation speed sensor 6 throttle chamber 7 throttle opening sensor 8 crank pulley 9 belt 10 pulley 11 idler pulley

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoichi Uraki 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd.

Claims (4)

[Claims] 1. An internal combustion engine having a main flywheel on a rotating shaft, means for detecting or estimating a fluctuating torque generated by the internal combustion engine, and a sub-fly rotating in a reverse direction at a fixed ratio to a rotation speed of the internal combustion engine. A wheel, and control means for controlling the torque generated by the sub flywheel in accordance with the fluctuating torque, wherein the control means changes the torque generated by the sub flywheel to reduce the fluctuating torque. A torque fluctuation control device, characterized in that: 2. The torque fluctuation control device according to claim 1, wherein a motor generator having both a power generation mechanism and a drive mechanism is used as said control means. 3. The torque fluctuation control device according to claim 2, wherein the motor generator also serves as an engine starting device and a power generation device. 4. The difference between the inertial mass of the main flywheel and the product of the ratio of the rotational speed of the internal combustion engine to the rotational speed of the sub-flywheel, which is obtained by subtracting the product of the inertial mass of the sub-flywheel and the rotational speed of the sub-flywheel. The torque fluctuation control device according to any one of claims 1 to 3, wherein the torque fluctuation control device is larger than 1/2 of an equivalent inertial mass including a wheel.