JP2816380B2 - Viscous damper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous damper mounted on a rotary shaft such as a crankshaft of a diesel engine for a vehicle to reduce torsional vibration of the rotary shaft.

[0002]

2. Description of the Related Art A plate-shaped damper plate which is fixed to a rotating shaft such as a crankshaft of a vehicle diesel engine which generates torsional vibration and rotates integrally with the rotating shaft. A hollow annular casing concentrically disposed, an annular inertial body accommodated in the casing with an appropriate small gap between its inner wall surface, and an inner wall surface of the casing and the inertial body A viscous damper having a viscous liquid such as silicon oil filled in a gap between the viscous damper and the viscous damper is conventionally known.

In the conventional viscous damper, since the damper plate, the annular casing, and the inertial body are all made of a steel material or an iron-based material such as cast iron, the weight is essentially large, and particularly the crankshaft of a vehicle engine. In the case of a viscous damper mounted on a vehicle, a reduction in weight is required.

On the other hand, regarding the vibration damping action of the viscous damper,
It is advantageous that the weight of the inertial body is as large as possible within a design allowable range. However, it is advantageous that the annular casing and the damper plate are lightweight within an allowable range of strength. For this reason, when trying to reduce the weight of the viscous damper,
It is desirable that the annular casing and the damper plate are made of an aluminum alloy.

Generally, the annular casing has a casing body having a U-shaped cross section provided with an annular opening for inserting the inertial body on one side in the axial direction of the damper,
And a cover member for closing the opening after the inertial body is inserted. The cover member is provided with a small-diameter hole for filling a viscous liquid such as silicone oil inside the casing. Is closed by the plug member after the injection of the viscous liquid. Further, the plug member is usually attached to the cover member and then welded to the cover member in order to reliably prevent the leakage of the viscous liquid filled in the casing.

When the annular casing having the above structure is made of an aluminum alloy to reduce the weight and at the same time to improve the vibration damping function, the same aluminum alloy is usually used for both the casing body and the cover member. used. However, if a high-strength aluminum alloy is used to secure the necessary strength for the annular casing and the damper plate, the weldability of the plug member mounted in the small-diameter hole of the cover member after filling the casing with a viscous liquid is reduced. It is inferior and easily produces welding defects, and has disadvantages of lack of durability and reliability. Therefore, if an aluminum alloy material having good weldability is used in order to prevent the occurrence of the above welding defects, the strength of the annular casing and the damper plate is insufficient, so that sufficient durability and reliability can also be ensured. There is a problem that disappears.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a viscous damper having excellent durability and reliability, light weight, and excellent vibration damping performance. It is.

[0008]

In order to solve the above-mentioned problems, the present invention provides a plate-shaped damper plate which is fixed to a rotating shaft and rotates integrally with the rotating shaft, and wherein the outer peripheral portion of the damper plate has the above-mentioned rotating member. A hollow annular casing disposed concentrically with respect to the shaft, an annular inertial body accommodated in the casing with an appropriate small gap between its inner wall surface, The annular casing is provided with a viscous liquid such as silicon oil filled in a gap between the inertial body and the casing body having an opening for inserting the inertial body, and the opening is closed after the inertial body is inserted. And a cover for forming the cover, the damper plate and the casing body are subjected to heat treatment after hot forging a high strength aluminum alloy having a large tensile strength.
A viscous damper characterized in that the cover member is formed by annularly punching or cutting an aluminum alloy having a lower tensile strength than the high-strength aluminum alloy and a lower weld strength than the high-strength aluminum alloy. It is.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. In the figure, reference numeral 10 generally indicates a viscous damper, which is fixed to a rotary shaft such as a crankshaft of a diesel engine (only the center line OO is shown) and integrated with the rotary shaft. It comprises a rotating plate-shaped damper plate 12 and a hollow annular casing 14 disposed concentrically with respect to the rotation shaft on the outer peripheral portion of the damper plate.

The annular casing 14 is formed integrally with the damper plate 12 and has an annular casing main body 16 having a U-shaped cross section open at one side in the axial direction, and is mounted on the open end of the casing main body 16. Thereafter, the outer peripheral edge and the inner peripheral edge thereof are caulked and fixed, and the cover member 18 is formed of an annular plate material.

The casing body 16 and the damper plate 12 are formed by hot rolling an aluminum alloy for wrought material having a large tensile strength and a large elongation, for example, JIS A6061 or an aluminum alloy plate having a tensile strength and an elongation equivalent thereto. Forged and molded, 100 ° C ~ 2 after quenching
Tempering treatment was performed at an appropriate temperature of 00 ° C. for an appropriate time (T
₆ ) Manufactured by performing necessary machining on forged blanks.

On the other hand, the cover member 18 is made of an aluminum alloy for wrought material having relatively low tensile strength but excellent weldability, for example, JIS A5454 or an aluminum alloy having tensile strength and weldability equivalent thereto. It is manufactured by punching or cutting a plate into a ring. Cover member 18
One or more, usually at least two small diameter holes 20 are drilled. A screw is cut into each small-diameter hole 20. As will be described later, for example, a plug member 22 made of the above-mentioned JIS 5454 or an aluminum alloy for wrought material having excellent weldability equivalent thereto is screwed. Blocked by

An appropriate small gap, for example, 0.3 to 0.5 m, is formed between the inside of the annular casing 14 and the inner wall surface thereof.
inertia body 2 having a substantially rectangular cross section with a gap of m
4 are accommodated. The inertial body 24 includes the viscous damper 10
From the viewpoints of vibration damping function and strength, the steel is usually made of an iron-based material, for example, ductile cast iron or steel, and subjected to necessary machining. The inertial body 24 and the annular casing 14
Between the inner wall surface and a viscous liquid having an appropriate viscosity, for example,
100,000 to 300,000 CSt (at 25 ° C) silicone oil 2
6 are filled.

A plurality of ring-shaped bearings 28 made of Teflon resin are disposed on two side surfaces of the inertial body 24 perpendicular to the axis at appropriate intervals in the circumferential direction. An annular bearing 30 made of Teflon resin is arranged on the inner peripheral surface of the annular body 24. Further, the damper plate 12 is provided with a plurality of bolt holes 34 for fixing the damper plate to the rotating shaft at regular intervals in the circumferential direction.

In manufacturing the viscous damper 10,
The inertial body 24 and the bearing 2 are provided inside the annular casing 14.
8 and 30, the annular cover member 18 is mounted in the opening of the casing body 16, and the thin edges 36 and 38 of the opening edge of the casing body 16 are interposed with a suitable sealing material (not shown). The cover member 18 is fixed by swaging.

Next, a viscous liquid such as silicone oil is injected and filled into the inside of the annular casing 14 from the small-diameter hole 20 formed in the cover member 18, and the plug member 22 is screwed into the small-diameter hole 20. . Further, the annular casing 14
The viscous liquid filled in the plug member 22 expands and contracts due to a change in temperature.
The outer peripheral surface of the plug member 22 is welded to the cover member 18 in order to prevent the viscous liquid from leaking outside or the outside air into the annular casing through the zero screw groove. .

In the viscous damper 10, when a torsional vibration occurs on a rotating shaft such as an engine crankshaft, a relative rotational displacement is generated between the inner wall surface of the annular casing 14 and the outer peripheral surface of the inertia body 24, and the silicon oil Shear resistance is generated based on the viscosity of the isotropic liquid, and a vibration damping effect is achieved. . At this time, the damper plate 12, the annular casing 14, and the cover member 1 fixed to a rotating shaft such as a crankshaft.
8 can be made of an aluminum alloy in place of the conventional iron-based material to reduce the weight, and reduce the mass of the rotating shaft system to improve the vibration damping function of the viscous damper 10.

During operation of the viscous damper 10, not only a large radial force due to centrifugal force acts on the annular casing 14 and the damper plate 12, but also when the rotating shaft is an engine crankshaft or the like, the same crankshaft is used. When bending vibration occurs in the shaft, the viscous damper 10 causes a displacement of reciprocating tilting back and forth in the direction of the crank axis, and a large bending force acts on the damper plate 12 and the joint between the damper plate and the annular casing 14. . In response to these large acting forces, the casing body 16 of the annular casing 14 and the damper plate 12
Sufficient strength can be ensured by hot forging and forming a high strength aluminum alloy plate material such as A6061 and performing an annealing treatment. In addition, since the high-strength aluminum alloy has excellent elongation, when the thin-walled edges 36 and 38 on the inner and outer circumferences of the cover member 18 are swaged, the soundness of the swaged portion can be ensured.

Next, since the cover member 18 for closing the opening of the annular casing 14 is made of an aluminum alloy plate material such as JIS A5454 which has a relatively small tensile strength but excellent weldability, the plug member 18 is used. Member 22
When the outer peripheral surface is welded after the mounting, sound welding that does not cause welding defects can be easily performed. As a result, the durability and reliability of the entire viscous damper 10 can be ensured.

[0020]

As described above, the viscous damper according to the present invention includes a plate-shaped damper plate fixed to a rotating shaft and rotating integrally with the rotating shaft, and the rotating shaft attached to an outer peripheral portion of the damper plate. A hollow annular casing concentrically disposed with respect to the casing, an annular inertia body accommodated in the casing with an appropriate small gap between its inner wall surface, Comprising a viscous liquid such as silicone oil filled in the gap between the body and the annular casing,
In the case where the casing body having an opening for inserting the inertial body and a cover for closing the opening after the inertial body is inserted, the damper plate and the casing body have a high tensile strength. Formed by heat treatment after hot forging of high strength aluminum alloy
And, the cover member is characterized by being formed by annularly punching or cutting an aluminum alloy having a smaller tensile strength than the high-strength aluminum alloy and a good weldability, and is lightweight and excellent in vibration damping function, There is an advantage that a viscous damper having excellent durability and reliability can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a partial front view as viewed from the direction of arrow II in FIG. 1;

[Explanation of symbols]

 Reference Signs List 10 viscous damper 12 damper plate 14 annular casing 18 cover member 24 inertia body 26 viscous liquid

Claims (1)

(57) [Claims] A damper plate fixed to a rotating shaft and rotating integrally with the rotating shaft; a hollow annular casing disposed concentrically with the rotating shaft on an outer peripheral portion of the damper plate; An annular inertial body accommodated in the casing with an appropriate small gap between the casing and an inner wall surface thereof, and a silicone oil or the like filled in a gap between the casing inner wall surface and the inertial body. A viscous liquid, wherein the annular casing is formed from a casing body having an opening for inserting the inertial body, and a cover for closing the opening after the inertial body is inserted, wherein the damper plate And the casing body is subjected to heat treatment after hot forging a high strength aluminum alloy with high tensile strength
A viscous damper, wherein the cover member is formed by annularly punching or cutting an aluminum alloy having a lower tensile strength and a better weldability than the high-strength aluminum alloy.