JPH024269Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a flywheel for an internal combustion engine, and in particular, the flywheel is divided into two parts and connected by a spring member to absorb torque fluctuations. It concerns an absorption flywheel.

[Conventional technology]

Vehicle body vibration caused by vehicle engine vibration,
In order to reduce cabin noise, especially ride comfort and muffled noise at low speeds, it is necessary to reduce engine torque fluctuations (rotation fluctuations). Conventionally, in order to reduce engine torque fluctuations, the flywheel was divided into two parts, one flywheel was connected to the engine crankshaft, the other flywheel was connected to the power train system, and these two flywheels were connected using a spiral spring. Two-part flywheels connected via a 2-split flywheel are already known (for example, Japanese Utility Model Publication No. 19218/1983, Japanese Patent Application Laid-open No. 66542/1983,
(Japanese Unexamined Patent Publication No. 1989-89000).

[The problem that the idea aims to solve]

However, in a conventional two-part flywheel having a spiral spring, the connecting portion of one end of the spiral spring to the driving side flywheel and the connecting portion of the other end of the spiral spring to the driven side flywheel are connected to the flywheel axis. Since they were not provided at symmetrical positions with respect to the plane perpendicular to the core, bending moments in the plane including the flywheel axis were likely to occur in the flywheel assembly.
For this reason, it is not enough to balance the drive-side flywheel and the driven-side flywheel individually; it is important to balance the assembly including the spiral spring, which makes balancing difficult.

The present invention provides a torque fluctuation absorbing flywheel consisting of a two-part flywheel having a spiral spring, which requires only the driving side flywheel and the driven side flywheel to be balanced individually. With the goal.

[Means to solve the problem]

According to the present invention, the above object is achieved by the following torque fluctuation absorbing flywheel. That is, a driving side flywheel and a driven side flywheel that can rotate relative to each other around the same axis, and a spiral shape around the axis that connects the driving side flywheel and the driven side flywheel. In the torque fluctuation absorbing flywheel, the spiral spring has a two-stage spiral shape that is formed in a spiral shape on the driving side flywheel side and then in a spiral shape on the driven side flywheel side. A torque fluctuation absorbing flywheel characterized in that the spiral spring is a spring, and both ends of the spiral spring are provided symmetrically with respect to the flywheel surface.

[Effect]

The torque fluctuation absorbing flywheel of this invention has
When a radial force is applied from the end of the spiral spring to the driving and driven flywheels due to the centrifugal force acting on the spiral spring, both ends of the spiral spring
Since they are at symmetrical positions with respect to a plane perpendicular to the flywheel axis, the force applied from the spiral spring applies moments in opposite directions to the driving flywheel and driven flywheel, and
Balance is maintained as a flywheel assembly. Therefore, when balancing in the in-plane direction including the flywheel axis, it is sufficient to balance only the drive-side flywheel and the driven-side flywheel separately.

〔Example〕

Preferred embodiments of the torque fluctuation absorbing flywheel according to the present invention will be described below with reference to the drawings.

1 and 2 relate to one embodiment of the present invention. The torque fluctuation absorbing flywheel is shown, and the flywheel is the drive side flywheel 1.
It has a two-part structure including a driven side flywheel 2 and a driven side flywheel 2. The drive-side flywheel 1 is attached to a flywheel bolt 4 to the crankshaft 3 of the engine.
Fixed by Although not shown, the driven flywheel 2 is connected to a power train system via a clutch. The drive side flywheel 1 and the driven side flywheel 2 are arranged on the same flywheel axis 5, and the driven side flywheel 2
is supported around the bearing portion 6 of the drive-side flywheel 1 so as to be relatively rotatable.

A space 7 is formed between the side surfaces of the drive side flywheel 1 and the driven side flywheel 2.
A spiral spring 8 is provided in the space 7. As shown in FIG. 3, the spiral spring 8 is formed in a spiral shape around the flywheel axis 5, and is formed in a spiral shape such that the diameter of the spiral becomes larger on the drive side flywheel 1 side. The spring is configured as a two-stage spiral spring formed so that the diameter of the spiral becomes smaller on the driven side flywheel 2 side.

At both ends of the spiral spring 8, bent portions 8a are bent toward the driving flywheel 1 side and the driven flywheel 2 side, respectively.
8b. The bent portions 8a and 8b at both ends of the spiral spring 8 are provided at symmetrical positions with respect to a plane perpendicular to the flywheel axis 5 in a neutral state where torque fluctuation is zero. The bent portions 8a and 8b are inserted and fixed into the corresponding holes 9 of the drive-side flywheel 1 and holes 10 of the driven-side flywheel 2, respectively. Therefore, the driving side flywheel 1 and the driven side flywheel 2 are connected via the spiral spring 8 in the relative rotation direction. Further, the spring constant of the spiral spring 8 in the torsional direction is set to be sufficiently low.

Next, the effect will be explained.

Bent portions 8a, 8 at both ends of the spiral spring 8
b are at symmetrical positions with respect to the plane perpendicular to the flywheel axis 5, so the radius applied from the spiral spring 8 to the drive side and driven side flywheels 1 and 2 due to the centrifugal force acting on the spiral spring 8 The force directed in the direction generates a bending moment in the drive side flywheel 1 and the driven side flywheel 2 in opposite directions. Therefore, the bending moments in opposite directions cancel each other out, and the flywheel assembly does not generate any bending moment in the in-plane direction including the flywheel axis 5 when the torque fluctuation is zero or near zero. Become. Therefore, the bending moment can be balanced for each of the drive-side flywheel 1 and the driven-side flywheel 2, making it extremely easy to balance the bending moment.

In addition, since the spiral spring 8 is composed of a single spiral spring arranged in two stages in series, the spring constant can be easily lowered and the spring can be freely adjusted compared to a single stage spiral spring or a plurality of spiral springs arranged in parallel in multiple stages. The resonant frequency of the flywheel vibration system, in which the two inertial masses of the driving flywheel 1 and the driven flywheel 2 are connected by a low spring constant spiral spring 8, can be set to It can be easily removed from the 0.5th order frequency. For example, in a two-part flywheel using a single-stage spiral spring, the resonant frequency (approximately 600 rpm) of a two-part flywheel using a conventional coil spring
The resonance frequency will be lower (approximately 400 rpm), and the vibration will be at the 0.5th order of engine rotation (in the case of a 4-cylinder engine, the explosion stroke of one cylinder will occur once every two revolutions of the engine, so if uneven combustion pressure occurs in one cylinder) It causes torque fluctuation of rotation 0.5 order and reduces idle speed.
800 rpm, the frequency of torque fluctuation of the 0.5th order of rotation is 400 rpm), and since the resonance frequency becomes large with a two-part flywheel using multi-stage parallel spiral springs, the engine pulls in as it approaches idle rotation. However, in the case of a single spiral spring 8 with two stages in series as in the present invention, the resonant frequency can be set much more freely than with single-stage or multi-stage parallel springs. The resonance frequency is set apart from the engine's first-order and 0.5th-order vibration frequencies.

[Effect of idea]

According to the torque fluctuation absorbing device according to the present invention, since both ends of the spiral spring are provided in symmetrical positions with respect to a plane perpendicular to the flywheel axis, the bending moment in the plane including the flywheel axis can be balanced. This can be achieved by balancing the drive side flywheel and driven side flywheel individually.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a torque fluctuation absorbing flywheel according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the device shown in FIG. 1 viewed from direction A, and FIG. 3 is a perspective view of a spiral spring. It is. 1... Drive side flywheel, 2... Driven side flywheel, 5... Flywheel axis, 8
...Spiral spring, 8a, 8b...Bend portion (both ends of the spiral spring).

Claims (1)

[Claims for Utility Model Registration] A driving flywheel and a driven flywheel that are rotatable relative to each other about the same axis, and a shaft center that connects the driving flywheel and the driven flywheel. In the torque fluctuation absorbing flywheel, the spiral spring has a spiral shape, and the spiral spring is formed into a spiral shape on the driving side flywheel side, and then formed into a spiral shape on the driven side flywheel side. A torque fluctuation absorbing flywheel characterized in that it is a two-stage spiral spring, and both ends of the spiral spring are provided symmetrically with respect to the flywheel surface.