JP2501764Y2 - Crankshaft sound absorption structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a sound absorbing structure of a crankshaft for reducing noise generated from the inside of a pulley fixed to a crankshaft of an automobile engine. .

(Prior Art) A diesel engine and a gasoline engine are configured as shown in FIG. That is, 1a is an engine body, 1b is a radiator, and 1c is a cooling fan connected to a crankshaft 1 described later. As shown in FIG. 4, the front end portion of the crankshaft 1 projects to the outside from the opening hole 3 of the front cover 2. An oil seal 4 that seals the crankshaft 1 is attached to the inner peripheral surface of the opening hole 3, and a crank gear 5 is fitted to the crankshaft 1 located inside the front cover 2 to provide a front cover. A pulley 6 is fixed to a tip end portion of the crankshaft 1 which projects outward from the shaft 2.

The pulley 6 is for driving auxiliary equipment such as a water pump, an alternator and an air conditioner / compressor. The outer peripheral wall portion 7 is provided with a plurality of V grooves 8 and the end surface portion 9 of the pulley 6 is fixed by a bolt 10. It is fixed to the crankshaft 1. Further, a torsional damper 11 is fixed to the pulley 6 by a bolt 12 so that the crankshaft 1 absorbs inherent torsional vibration and noise when the explosion pressure from the piston or a sudden change in the rotation speed is received. Has become.

(Problems to be solved by the invention) However, the pulley 6 provided at the tip of the crankshaft 1 configured as described above has a plurality of V grooves for driving auxiliary equipment such as a water pump, an alternator and an air conditioner / compressor. 8 must be provided, and the outer peripheral wall portion 7 of the pulley 6 is formed wide. And the pulley 6
The front end surface of the outer peripheral wall portion 7 is close to the outer surface of the front cover 2, and an annular space 13 surrounded by the pulley 7, the front cover 2 and the crankshaft 1 is formed.

Therefore, when the pulley 6 and the torsional damper 11 rotate integrally with the rotation of the crankshaft 1, a standing wave is generated in the annular space 13, which causes noise and leaks to the outside.

The present invention has been made in view of the above circumstances, and its purpose is to absorb a standing wave generated in an annular space surrounded by a pulley, a front cover, and a crankshaft with a simple structure. It is to provide a sound absorbing structure for a crankshaft.

[Structure of the Invention] (Means and Actions for Solving the Problem) In order to achieve the above-mentioned object, the present invention uses a ring-shaped porous member fitted to the crankshaft on the inner surface of the outer peripheral wall of the pulley. To fix the sound absorbing material.

The sound absorbing material absorbs a standing wave generated in an annular space surrounded by the pulley, the front cover and the crankshaft, and reduces noise leaking to the outside.

(Embodiment) Hereinafter, each embodiment of the present invention will be described with reference to the drawings. However, the same components as those of the related art will be denoted by the same reference numerals and description thereof will be omitted.

FIG. 1 shows a first embodiment, in which a sound absorbing material 20 is fixed to an outer peripheral wall portion 7 of a pulley 6 fixed to a tip end portion of a crankshaft 1. The sound absorbing member 20 is a ring-shaped member made of a porous metal plate, the outer peripheral edge portion of which is press-fitted inside the outer peripheral wall portion 7 of the pulley 6 and further fixed by a fixing ring 21. The through hole 22 of the sound absorbing material 20 is fitted into the crankshaft 1 so as to rotate integrally with the pulley 6.

By thus providing the sound absorbing material 20 in the annular space 13 surrounded by the pulley 6, the front cover 2 and the crankshaft 1, it is possible to absorb the standing wave generated in the annular space 13 and reduce the noise leaking to the outside. it can.

FIG. 2 shows a second embodiment, in which a sound absorbing material 23 is fixed to the outer peripheral wall portion 7 of the pulley 6 fixed to the tip portion of the crankshaft 1. The sound absorbing material 23 is a ring-shaped member made of porous rubber, resin, or ceramic, and its outer peripheral edge portion is fixed to the annular member 24 press-fitted inside the outer peripheral wall portion 7 of the pulley 6 by adhesion or the like. The through hole 25 of the sound absorbing material 23 is fitted to the crankshaft 1 so as to rotate integrally with the pulley 6.

By thus providing the sound absorbing material 23 in the annular space 13 surrounded by the pulley 6, the front cover 2 and the crankshaft 1, it is possible to absorb a standing wave generated in the annular space 13 and reduce noise leaking to the outside. it can.

[Advantages of the Invention] As described above, according to the present invention, a sound absorbing member made of a ring-shaped porous member that fits with the crankshaft is fixed to the inner surface of the outer peripheral wall of the pulley, and the pulley, the front cover, and Since it has a structure that absorbs the standing waves generated in the annular space surrounded by the crankshaft, it has a simple structure.
There is an effect that noise leaking to the outside can be reduced.

[Brief description of drawings]

1 is a vertical sectional side view of a crankshaft sound absorbing structure showing a first embodiment of the present invention, and FIG. 2 is a vertical sectional side view of a crankshaft sound absorbing structure showing a second embodiment of the present invention. FIG. 4 is a schematic configuration diagram of a general engine, and FIG. 4 is a vertical sectional side view showing a relationship between a conventional crankshaft and a pulley. 1 ... Crank shaft, 2 ... Front cover, 6 ...
… Pulley, 13 …… annular space, 20,23 …… sound absorbing material.

Claims (1)

(57) [Scope of utility model registration request] 1. A crankshaft having a crankshaft of an engine protruding outward from a front cover, a pulley fixed to the protruding portion, and a torsional damper provided on the pulley, and an inner surface of an outer peripheral wall of the pulley. A sound absorbing member made of a ring-shaped porous member that fits with the crankshaft is fixed to the structure, and a standing wave generated in an annular space surrounded by the pulley, the front cover and the crankshaft is absorbed. Sound absorption structure of the crankshaft.