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Flywheel assembly for internal combustion engine

a technology of internal combustion engine and crankshaft, which is applied in the direction of process and machine control, mechanical control devices, instruments, etc., can solve the problems of clutch disengagement failure, thick sound or noise, delay in the response of the clutch engaging and disengaging,

Inactive Publication Date: 2007-02-13
HITACHI LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides a crankshaft assembly for an internal combustion engine that can eliminate defects in the background art. It effectively shifts a resonance frequency of a flexural or bending vibration out of a target frequency band of a forced vibration, preventing occurrence of a thick sound or noise in an engine room. It also prevents occurrence of a fore and aft vibration of a vehicle floor at the time of engagement of the clutch. The crankshaft assembly includes a crankshaft, an elastic member fixed to the crankshaft, and a flywheel fixed to the elastic member. The flywheel has an engageable surface that is engageable with an associated member of the clutch to receive a load therefrom in the axial direction. The elastic member has a first predetermined rigidity in its rotating direction and a second predetermined rigidity in the axial direction. The engageable surface is designed to have an axial run-out of no more than 0.1 mm for ensuring a smooth engagement with the associated member of the clutch.

Problems solved by technology

However, the mass of the flywheel tends to generate a flexural or bending vibration in an axial direction of the crankshaft which causes a thick sound or noise in an engine room and thus in a vehicle compartment for an automotive vehicle, particularly at the time of the acceleration of the vehicle.
However, the background art as mentioned above has the following problems.
When the rigidity of the elastic plate in the axial direction (hereinafter referred to as “the axial rigidity”) is too small, a clutch stroke for engaging and disengaging the clutch is likely to become larger, resulting in a delayed response of the clutch engaging and disengaging operations leading particularly to failure of the clutch disengagement which is likely to cause such as an engine stall.
On the other hand, when the axial rigidity of the elastic plate is too large, the deviation of the resonance frequency of the bending vibration from the target frequency band of the forced vibration can not be ensured.
Further, in the background art, when the flywheel is rotated, an axial run-out occurs on an engaging surface of the flywheel with a clutch facing of a clutch disc provided adjacent to the flywheel, due to a processing error and an assembling error of the elastic plate and the flywheel.
Such vibration is uncomfortable for the driver and passengers in the vehicle compartment.

Method used

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  • Flywheel assembly for internal combustion engine
  • Flywheel assembly for internal combustion engine
  • Flywheel assembly for internal combustion engine

Examples

Experimental program
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Effect test

first embodiment

[0041]As understood from the above description, this first embodiment, when the crankshaft 1 is rotated, the flywheel body 5 is ensured to rotate with the crankshaft 1 by means of the large circumferential rigidity of the elastic plate 2. When the clutch is engaged and the engine is accelerated, the driving power is transmitted to the transmission with a very low bending vibration level by means of the axial rigidity of the elastic plate being no more than 2200 kg / mm, so that the vehicle compartment can be kept quiet. On the other hand, when the clutch is disengaged, since the axial displacement of the flywheel is no more than 5% of the normal clutch stroke by means of the axial rigidity of the elastic plate being no less than 600 kg / mm, the failure of the disengagement of the clutch is effectively prevented.

second embodiment

[0042]FIG. 3 shows a crankshaftflywheel assembly for an internal combustion engine according to the present invention. In FIG. 3, the same or like parts or members are denoted by the same reference numerals. In the following description, explanations of those same or like members will be omitted to avoid redundant description. Further, though the clutch assembly is not shown in FIG. 3, the same clutch assembly including the clutch disc 9 and the clutch facing 8 is provided in the same manner as in FIG. 1.

[0043]In FIG. 3, the crankshaft 1 includes a stepped end surface having a first section 1a extending radially inward from its outer peripheral edge, a second section 1b extending axially from the inward end of the first section 1a toward the clutch disc 9, and a third circular section 1c extending radially from the second section 1b. The elastic plate 2 is of an annular shape having a mounting opening at its center for receiving the second section 1b therethrough. The elastic plate ...

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Abstract

A crankshaft assembly for an internal combustion engine includes a crankshaft, an elastic member fixed to the crankshaft, and a flywheel fixed to the elastic member such that the flywheel is supported in an elastic relationship with the crankshaft. The elastic member has a rigidity in its rotating direction large enough to effectively transmit a driving power to a transmission through a clutch. On the other hand, the elastic member has a rigidity in an axial direction of the crankshaft small enough to shift a resonance frequency of a bending vibration out of a target frequency band of a forced vibration, while ensuring to prevent a failure of disengagement of the clutch.

Description

[0001]This application is a continuation of application Ser. No. 07 / 485,659 filed Feb. 27, 1990 now abandoned.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a crankshaft assembly including a flywheel, for an internal combustion engine. More specifically, the present invention relates to a crankshaft assembly for an internal combustion engine, which can effectively shift a resonance frequency of a flexural or bending vibration of the crankshaft assembly out of a target frequency band of a forced vibration which results such as during acceleration of a vehicle so as to effectively prevent occurrence of a thick sound or noise in an engine room, while ensuring a quick response for clutch engaging and disengaging operations, and / or which can prevent occurrence of a fore and aft vibration of a vehicle floor at the time of engagement of the clutch.[0004]2. Description of the Background Art[0005]In a known crankshaft assembly for an internal...

Claims

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Application Information

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Patent Type & Authority Patents(United States)
IPC IPC(8): F16C3/04G05G1/00F16D13/70F16F15/12F16F15/131
CPCF16D13/70F16F15/12F16F15/1315Y10T74/2184Y10T74/2131Y10T74/2173
Inventor KONO, SATOSHIHIDAKA, SHIZUAKITAKAHASHI, TETSU
Owner HITACHI LTD