JPH0720442U - Torsional damper - Google Patents

Abstract

(57) [Summary] [Object] To suppress noise emitted from the cast window 11b of the hub 11 to improve quietness when the engine is driven, and to effectively prevent dust from entering the engine. [Structure] A plurality of casting windows 11b at predetermined intervals in the circumferential direction
Of the skeleton type hub 11 in which the hub 11 is opened, the annular mass body 12 arranged in proximity to the hub 11, and the elastomer member 13 elastically connecting the hub 11 and the annular mass body 12 to each other. The cover plate 15 fixed to the cylindrical portion 11c and surrounding the space on the front side of the hub 11 over the entire circumference, and the cover plate 1
5 and the hub 11 and a dust seal member 16 that seals between the hub 5 and the hub 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a torsional damper which is attached to an axial end of a crankshaft of an engine and which mainly suppresses vibration in a torsion direction thereof, and particularly to a torsional damper in which a hub has a skeleton shape.

[0002]

[Prior art]

 As shown in the conventional example in FIG. 4, this type of torsional damper is basically a hub 1 fixed to the shaft end of a crankshaft of an engine, and an annular mass body arranged near the hub 1. It has a structure in which 2 and 2 are elastically connected via an elastomer member 3, and a resonance system composed of the annular mass body 2 and the elastomer member 3 resonates so as to cancel out the vibration of the crankshaft, and is mainly twisted. It has a significant damping function against vibration (vibration in the direction of rotation). Further, in this conventional example, the hub 1 is made to have a skeleton shape in which a plurality of cast-out windows 1a are formed at a predetermined interval in the circumferential direction in the radial middle portion of the hub 1 for weight reduction.

[0003]

[Problems to be solved by the device]

 However, in the torsional damper having the skeleton-shaped hub 1 as described above, the noise from the engine on the right side of the drawing passes through the casting window 1a of the hub 1 and is emitted to the front side as it is. Moreover, since the cast window 1a itself produces wind noise due to rotation, it may cause a problem in terms of quietness. It is also pointed out that the presence of the casting window 1a makes it easier for dust such as muddy water from the front side to enter the crankshaft penetration portion of the engine.

Therefore, the main object of the present invention is to suppress the sound emitted from the cast window of the skeleton type hub to improve the quietness when the engine is driven and to effectively prevent the dust from entering the engine side. Especially.

[0005]

[Means for Solving the Problems]

 The above technical problems can be effectively solved by the present invention. That is, the torsional damper according to the present invention comprises a skeleton hub fixed to a crankshaft and having a plurality of cast-out windows at predetermined intervals in the circumferential direction, an annular mass body arranged in proximity to the hub, and the hub. And an elastic member that elastically connects the annular mass body with a metal cover plate that is fixed to the outer diameter cylindrical portion of the hub and surrounds the front side space of the hub over the entire circumference, A dust seal member for sealing between the cover plate and the hub is provided.

[0006]

[Action]

 The cover plate blocks the engine sound passing through the cast window of the skeleton hub and the wind noise generated by the cast window itself from radiating to the front side of the torsional damper, and the dust seal member from the front side. Prevents dust such as muddy water from entering the engine's crankshaft penetration through the non-impingement area between the cover plate and the hub and through the hub cast window. This cover plate is formed integrally with the sheet metal pulley in the case where the sheet metal pulley is attached to the hub, and a metal sleeve in which an elastomer member is fitted on the outer peripheral surface of the outer diameter cylindrical portion of the hub and its In the case of a bush type that is molded and bonded with the annular mass body on the outer peripheral side, by forming it integrally with this metal sleeve, the cover plate does not increase the number of parts.

[0007]

【Example】

 FIG. 1 shows a first preferred embodiment of a torsional damper according to the present invention. That is, reference numeral 11 is fixed to a shaft end of a crankshaft (not shown) of an engine by a cylindrical boss portion 11a formed on the inner circumference, and a plurality of castings are formed at a predetermined interval in the circumferential direction on a radial middle portion. A skeleton-shaped hub whose weight is reduced by opening a window 11b, 12 is an annular mass body which is arranged on the outer peripheral side of the hub 11 and has a pulley groove 12a formed on the outer peripheral surface, and 13 is the hub 11 and the annular mass body. It is an annular elastomer member that elastically connects 12 together. This torsional damper is of a so-called bush type, in which the elastomer member 13 is fitted to the outer peripheral surface of the outer diameter cylindrical portion 11c of the hub 11 and the annular mass body radially opposed to the sleeve 14. It is vulcanized and bonded in an annular shape with the inner peripheral surface of 12.

On the front side of the hub 11 (on the side opposite to the engine), a disk-shaped metal cover that covers the entire circumference of the front-side space in the radial middle part of the hub 11 and blocks sound from the cast window 11b. The bar plate 15 is arranged, and its outer diameter edge 15a is fitted on the inner peripheral surface of the front end of the outer diameter cylindrical portion 11c of the hub 11. At the inner diameter end 15b of the cover plate 15 which reaches the vicinity of the outer periphery of the boss portion 11a of the hub 11, a dust seal member 16 is fixed to prevent dust such as muddy water from entering the casting window 11b from the front side. The inner diameter of the dust seal member 16 is in close contact with the outer peripheral surface of the boss portion 11a. As the dust seal member 16, typically, a lip-shaped packing or another elastic packing is used.

Next, FIG. 2 shows a second preferred embodiment of the present invention. This torsional damper is of a so-called fitting type, and the elastomer member 13 is provided between the outer peripheral surface of the outer diameter cylindrical portion 11c of the hub 11 and the inner peripheral surface of the annular mass body 12 radially opposed thereto. It is press-fitted into. In the cross-sectional shape shown in the drawing cut along a plane passing through the axis O, the outer peripheral surface of the outer diameter tubular portion 11c of the hub 11 is formed in a curved shape in which the central portion in the axial direction is partially raised. Since the inner peripheral surface of the annular mass body 12 on the outer peripheral side is formed in a curved shape in which the axial center portion is partially recessed correspondingly, the press-fitted elastomer member 13 is also curved, whereby the hub. 11 has a so-called convolution-shaped fitting structure in which the fitting surfaces of the elastomeric member 13 and the annular mass body 12 are prevented from shifting in the axial direction.

A sheet metal pulley 17 is provided on the front side of the hub 11, and the cover plate 15 is integrally extended from an inner diameter portion 17 a of the sheet metal pulley 17. Therefore, according to this embodiment, it is not necessary to separately manufacture the sheet metal pulley 17 and the cover plate 15, and it is not necessary to attach the hub 11 to the hub 11 in separate steps. In this case, the outer diameter edge 15a of the cover plate 15 fitted to the inner peripheral surface of the end of the outer diameter cylindrical portion 11c of the hub 11 also serves as the fixing means of the sheet metal pulley 17 to the hub 11. The fitting area is larger than that of the first embodiment in FIG.

Next, FIG. 3 shows a third preferred embodiment of the present invention. That is, this torsional damper has a bush type structure similar to that of the first embodiment in FIG. 1, but the cover plate 15 is fitted on the outer peripheral surface of the outer diameter cylindrical portion 11c of the hub 11. An elastomer member 13 between the inner peripheral surface of the annular mass body 12 and the outer peripheral surface of the annular mass body 12 integrally extends from the front end of the vulcanized sleeve 14 to the inner diameter side. Therefore, according to this embodiment, it is not necessary to separately manufacture the sleeve 14 and the cover plate 15, and it is not necessary to attach the sleeve 14 and the cover plate 15 to the hub 11 in separate steps. It is possible to reduce the number of parts and the number of assembling steps in comparison.

[0012]

[Effect of device]

 According to the present invention, in a torsional damper having a skeleton hub for weight reduction, it is possible to effectively reduce radiation noise and wind noise from the cast window of the hub, and to improve quietness. The front side dust can also be prevented from entering the crankshaft penetration part of the engine through the casting window, and the cover plate is a metal plate pulley attached to the hub or a metal sleeve to which the elastomer member is vulcanized. By integrally forming with the above, the above effect can be achieved without increasing the number of parts and the assembly process.

[Brief description of drawings]

FIG. 1 is a half sectional view of a first preferred embodiment of a torsional damper according to the present invention, taken along a plane passing through an axis.

FIG. 2 is a half sectional view of a second preferred embodiment of the torsional damper according to the present invention, taken along a plane passing through an axis.

FIG. 3 is a half sectional view of a third preferred embodiment of the torsional damper according to the present invention, taken along a plane passing through an axis.

FIG. 4 is a half sectional view of a conventional torsional damper taken along a plane passing through an axis.

[Explanation of symbols]

 11 Hub 11a Boss 11b Casting Window 11c Outer Diameter Cylindrical Part 12 Annular Mass 12a Pulley Groove 13 Elastomer Member 14 Metal Sleeve 15 Cover Plate 15a Outer Edge 15b Inner Diameter End 16 Dust Seal Member 17 Sheet Metal Pulley

Claims (3)

[Scope of utility model registration request] 1. A skeleton-shaped hub (11) fixed to a crankshaft and having a plurality of cast-out windows (11b) opened at predetermined intervals in a circumferential direction, and an annular mass body arranged in proximity to the hub (11) (12)
An elastomer member (13) for elastically connecting the hub (11) and the annular mass body (12), and the hub (11) fixed to the outer diameter tubular portion (11c) of the hub (11). And a dust cover member (16) for sealing between the cover plate (15) and the hub (11). . 2. The torsion damper according to claim 1, wherein the cover plate (15) is integral with a sheet metal pulley (17) fixed to the outer diameter cylindrical portion (11c) of the hub (11). 3. A cover plate (15) is fitted on the outer peripheral surface of the outer diameter cylindrical portion (11c) of the hub (11) and is provided between the outer peripheral side annular mass body (12) and an elastomer member ( 13) Metal sleeve (1) to be molded and bonded
The torsional damper according to claim 1, which is integral with 4).