JPH11351332A - Roll vibration reducing device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll vibration reducing device for internal combustion engine capable of ensuring a high roll vibration reducing effect up to a high frequency area while minimizing the increase in weight. SOLUTION: The crank shaft 1 of an engine is connected to the internal gear 4 of a first epicyclic gear mechanism to fix the revolution of the first planetary gear 13 of the first epicyclic gear mechanism, and the second planetary gear 15 of a second epicyclic gear mechanism is connected to a first sun gear 14, and a second sun gear 17 is arranged on the inside of the second planetary gear 15 by rotating fixation, whereby the second planetary gear 15 is rotated in the opposite direction to the crank shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reduction of roll vibration of an internal combustion engine applied to an automobile or the like.

[0002]

2. Description of the Related Art Direct-injection gasoline engines and direct-injection diesel engines have been in the limelight due to the increasing interest in improving fuel efficiency of automobiles in response to recent environmental problems. Due to the large excitation force, the roll vibration accompanying the torque fluctuation is also large,
Accordingly, there is a problem that a muffled sound and a floor vibration at the time of idling are deteriorated. As a method for solving such a problem, for example, as disclosed in Japanese Patent Application Laid-Open No. 6-42591 (FIG. 5) and Japanese Patent Application Laid-Open No. 6-50388 (FIG. 6), a sub-flywheel that rotates in reverse to the flywheel is added. Then, there is a method in which a moment in the opposite direction to the moment acting on the engine body is generated as a reaction to the generation of the torque, and the roll vibration of the engine body is reduced. However, this method causes an increase in engine weight and a problem of securing a space for arranging a sub flywheel, which has been a factor that hinders practical use. As one method for solving such a problem, as disclosed in Japanese Patent Application Laid-Open No. 7-35199 (FIG. 7) and Japanese Patent Application Laid-Open No. 9-242824 (FIG. 8), a crank pulley is cranked using a planetary gear mechanism. Reverse rotation with respect to the shaft, using the moment of inertia of the engine accessories driven by the crank pulley to generate a moment in the opposite direction to the moment acting on the engine body as a reaction to torque generation, and roll vibration of the engine body Can be reduced. This method effectively utilizes the existing inertial body called engine accessories,
There is an advantage that the roll vibration of the engine can be reduced without adding a new heavy object such as a sub flywheel.

[0003]

However, in a mechanism in which the above-described planetary gear mechanism is used to increase the speed of the crank pulley and the auxiliary devices with respect to the crankshaft in a reverse direction, inertia for generating a cancel torque is provided by the engine. There is a problem that the roll vibration is rather deteriorated in a band equal to or higher than the expansion / contraction resonance frequency of the accessory drive belt because of relying on the accessory. Further, in order to avoid these problems, when the roll vibration is reduced only by the inertia connected to the sun gear like a crank pulley, there is a problem that it is difficult to obtain a large reduction effect. The present invention has been made by focusing on the unresolved problems of the conventional technology, and while minimizing the weight increase,
An object is to secure a large roll vibration reduction effect up to a high frequency region.

[0004]

In order to achieve the above object, according to the present invention, a crankshaft of an engine is connected to an internal gear of a first planetary gear mechanism.
After fixing the revolution of the planetary gear of the first planetary gear mechanism, the planetary carrier of the second planetary gear mechanism is coupled to the first sun gear, and the second sun gear is fixedly arranged inside the second planetary carrier. The second planetary carrier is rotated in the direction opposite to the crankshaft. According to a second aspect of the present invention, the crankshaft of the engine is connected to the internal gear of the first planetary gear mechanism, the planetary gear of the first planetary gear mechanism is fixed in revolution, and the second sun gear is connected to the first sun gear. By connecting a planetary carrier of a planetary gear mechanism, arranging a second sun gear in rotation inside the second planetary carrier, and arranging a second internal gear outside the second planetary carrier, the second planetary The carrier and the second internal gear are rotated in a direction opposite to the crankshaft.

[0005]

According to the first aspect of the present invention, the second planetary carrier is configured to rotate in a direction opposite to the crankshaft, so that the revolution of the second planetary carrier and the rotation of the second planetary gear are performed. Thus, a higher equivalent moment of inertia can be obtained, and a large roll vibration reduction effect can be secured up to a high frequency band with a relatively small weight. In the invention according to claim 2, the second
Because the planetary carrier and the second internal gear are configured to rotate in the opposite direction of the crankshaft,
Due to the revolution of the second planetary carrier, the rotation of the second planetary gear, and the second internal gear rotated at a higher speed than the second planetary carrier, a larger equivalent inertia moment is obtained, and as a result, the weight is further reduced with a relatively small weight. A large roll vibration reduction effect can be secured in a high frequency band.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. First, Embodiment 1 of the present invention will be described with reference to FIG. In the present embodiment, an auxiliary machine is electrically driven by a separately provided motor generator, such as an engine for a hybrid vehicle, and it is not necessary to drive the auxiliary machine by the engine. FIG. 1 is a configuration diagram (longitudinal sectional view) of a roll vibration reduction device according to the present embodiment, and shows an enlarged view of an engine front end portion. In this embodiment, a chain sprocket 2, a spacer 3, and an internal gear 4 are fixed to a front end of a crankshaft 1 of an engine (not shown) with bolts 5. These three members are restrained from rotating with respect to the crankshaft 1 by a key 6 fitted on the crankshaft 1. An oil pump including an inner rotor 9 and an outer rotor 10 is configured between the front cover 7 and the case 8, and the oil pump is driven by the spacer 3. An oil seal 11 is provided between the front cover 7 and the planetary gear mechanism. The internal gear 4 meshes with a first planetary gear 13 held by a first planetary carrier 12. 1st planetary carrier 1
2 is fixed to the front cover 7. The first planetary gear 13 meshes with the first sun gear 14. First
A second planetary carrier 15 is connected to the sun gear 14. The second planetary gear 16 on the second planetary carrier 15 meshes with the second sun gear 17. The second sun gear 17 covers the entire device and covers the front cover 7.
Is mounted on a cover 18 which is fixed to the camera and does not rotate. An extension shaft 19 is provided coaxially with the second sun gear 17, and the first sun gear 14 is supported by a needle bearing 20 disposed on the extension shaft 19.

The mechanism for reducing the roll vibration by the above mechanism will be described with reference to FIG. Assuming that the engine generates a torque T (T is a function of time) by combustion, the internal gear connected to the crankshaft has the torque T and the drag N from the planetary gear as shown in FIG. , And a reaction force N acting as a result of supporting the reaction force N on the shaft portion acts. Assuming that the moment of inertia of the planetary gear is sufficiently small, a driving force N from the ring gear, a drag N from the sun gear, and a reaction force 2N resulting from supporting the driving force and the drag on the shaft portion act on the planetary gear. The driving force N from the planetary gear and the reaction force N generated as a result of supporting the driving force N on the shaft portion act on the sun gear and the auxiliary flywheel.

On the other hand, a reaction torque T of the generated torque and a force acting as a reaction of the reaction force generated on the shaft of each gear act on the engine body. As shown in FIG. 2B, the force is 2N, the moment arm length rs + rp (where rs is the sun gear, rp is the pitch circle radius of the planetary gear. When the reduction ratio of the planetary gear mechanism is 3, rs = rp. )
Acts as the opposite couple of the anti-torque of the engine. This couple acts as a cancel torque that cancels the torque reaction force, and as a result, roll vibration of the engine is reduced.
Here, I is the moment of inertia about the roll axis of the entire engine, φ is the roll angle displacement of the engine, and the engine rotation system (flywheel or drive plate, crankshaft, connecting rod rotation equivalent part, and internal gear)
Assuming that the inertia moment of the engine is I ₁ , the inertia moment of the sun gear and the auxiliary flywheel is I ₂ , and the speed increase ratio between the internal gear and the sun gear is ρ, the equation of motion for the roll vibration of the engine body is given by the following equation.

[0009]

(Equation 1)

[0010] As the coefficient relating to T on the right side of the equation approaches 0, the amount of reduction in roll vibration increases. In the present embodiment, the moment of inertia of the second planetary carrier 15 and the second planetary gear 16 serves as a sub flywheel.

Next, the equivalent moment of inertia when the second planetary carrier 15 rotates will be discussed using a simplified model with one planetary gear as shown in FIG. The moment of inertia of the planetary carrier is I _c ,
The angular displacement is θ _c , the weight of the planetary gear is m, the moment of inertia is Ig, the angular displacement is θg, and the displacement in the translation direction is x,
When the torque T acts on the planetary carrier, the equation of motion is described as follows.

(Equation 2)

[0012]

(Equation 3)

[0013]

(Equation 4) From the geometric relationship, the following relationship holds between the above equations.

(Equation 5)

[0014]

(Equation 6) The following equation is obtained by solving Equations 2 to 6 and organizing them.

(Equation 7) In the above equation, the second term in [] represents an increase in the inertia moment due to the revolution of the planetary gear, and the third term represents an increase in the inertia moment due to the rotation of the planetary gear. When there are n planetary gears, Equation 7 is expressed as follows.

(Equation 8)

From the above equation, it can be seen that as the number of planetary gears increases, the effect of increasing the equivalent moment of inertia during rotation of the planetary carrier due to the revolution and rotation of the planetary gears increases.

This embodiment is different from a conventional mechanism in which a planetary gear mechanism is used to increase the speed of a crank pulley and accessories to the crankshaft and reversely rotates the second planetary carrier as an inertia for generating a cancel torque. Since the equivalent moment of inertia at the time of 15 rotations is used, a large equivalent moment of inertia can be obtained with a small and lightweight structure, and a large roll vibration reduction effect can be obtained. Also, the second
Since the planetary carrier 15 is gear-driven, the roll vibration can be reduced to a high frequency.

Next, a second embodiment will be described with reference to FIG. FIG. 4 is a configuration diagram (longitudinal sectional view) of the roll vibration reduction device according to the second embodiment, and shows an enlarged view of the front end portion of the engine. The basic structure is almost the same as that of the first embodiment, except that a second internal gear 21 is provided outside the second planetary carrier 15.

In such a configuration, the effective radius of the second sun gear 17 is rs', the second internal gear 21
Is the effective radius of ri 'and the moment of inertia is I _i ,
Since the second internal gear 21 to rotate is ρ = (1 + rs '/ ri') double speed relative to the second sun gear 17, increasing by more [rho ² I _i the equivalent inertia moment about the second sun gear 17 Thus, the effect of reducing the roll vibration can be further increased.

[0019]

As described above, according to the first aspect of the present invention, the crankshaft of the engine and the internal gear of the first planetary gear mechanism are connected to each other to revolve the planetary gear of the first planetary gear mechanism. Is fixed, the planetary carrier of the second planetary gear mechanism is connected to the first sun gear, and the second sun gear is rotationally fixed inside the second planetary carrier. Since the rotation is performed in the opposite direction, a high equivalent moment of inertia can be obtained by the revolution of the second planetary carrier and the rotation of the second planetary gear, and a large roll vibration reduction effect can be obtained with a relatively small weight. The effect of securing up to the frequency band can be obtained. According to the invention described in claim 2, the crankshaft of the engine and the internal gear of the first planetary gear mechanism are connected to each other, and the planetary gear of the first planetary gear mechanism is fixed in revolution, and then the first sun gear is connected to the first sun gear. The second planetary gear mechanism is coupled with a planetary carrier, a second sun gear is fixedly arranged inside the second planetary carrier, and a second internal gear is arranged outside the second planetary carrier. Planetary carrier and the second
Since the internal gear and the internal gear are configured to rotate in a direction opposite to the crankshaft, the rotation of the second planetary carrier, the rotation of the second planetary gear, and the second internal gear that is further rotated at a higher speed than the second planetary carrier. As a result, a larger equivalent moment of inertia can be obtained, and as a result, an effect of securing a larger roll vibration reduction effect in a high frequency band with a relatively small weight can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a roll vibration reduction device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating a mechanism for reducing roll vibration by a planetary gear mechanism.

FIG. 3 is a diagram for explaining an increase in equivalent moment of inertia during rotation of a planetary carrier.

FIG. 4 is a schematic diagram of a roll vibration reduction device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a conventional technique.

FIG. 6 is a diagram showing a conventional technique.

FIG. 7 is a diagram showing a conventional technique.

FIG. 8 is a diagram showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Chain sprocket 3 Spacer 4 Internal gear 5 Bolt 6 Key 7 Front cover 8 Case 9 Inner rotor 10 Outer rotor 11 Oil seal 12 1st planetary carrier 13 1st planetary gear 14 1st sun gear 15 2nd planetary carrier 16 2nd planetary gear 17 second sun gear 18 cover 19 extension shaft 20 needle bearing 21 second internal gear

Claims (2)

[Claims] 1. A crankshaft of an engine and an internal gear of a first planetary gear mechanism are connected to each other, and after a planetary gear of the first planetary gear mechanism is fixed in revolution, a second sun gear of a second planetary gear mechanism is fixed to a first sun gear. The second planetary carrier is coupled to the second planetary carrier, and the second sun gear is fixedly arranged inside the second planetary carrier so that the second planetary carrier is rotated in the opposite direction to the crankshaft. Roll vibration reducing device for an internal combustion engine. 2. The planetary gear of the second planetary gear mechanism is fixed to the first sun gear after the crankshaft of the engine and the internal gear of the first planetary gear mechanism are connected to each other and the revolution of the planetary gear of the first planetary gear mechanism is fixed. A second sun gear is fixedly arranged inside the second planetary carrier, and a second internal gear is arranged outside the second planetary carrier.
A roll vibration reduction device for an internal combustion engine, wherein the planetary carrier and the second internal gear are configured to rotate in a direction opposite to a crankshaft.