JPS62180131A - Torsional damper and its manufacture - Google Patents

Abstract

PURPOSE:To make a torsional damper of a crank shaft of an internal combustion engine with an appropriate mass when manufacturing the damper by forming a damper pulley with plastic material injection molding and at the same time providing a circumferential elastic body with effective contractive function. CONSTITUTION:A torsional damper 10 consists of a damper pulley 12, a boss part 16 of a small-diametered cylindrical shape in which a metallic sleeve 14 is integrally arranged, a cylindrical part 18, and a connection part 20. When manufacturing the damper pulley 12, an elastic body 30 made of an elastic material such as rubber of a specified thickness is sulfurized and glued on the inner circumference of a damper mass 26 of a ring- or cylindrical shape. Then the mass and the sulfurized and glued elastic body are set in a specified injection mold die, and a specified plastic material is injected inside the mass and sulfurized and glued elastic body 30 to form the damper pulley 12 by injection molding. Simultaneously, it is made so that a specified contractive function is given to the elastic body 30 by means of the injection molding pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a torsional damper and a method for manufacturing the same, and in particular, by being attached to a rotating shaft such as a crankshaft of an internal combustion engine, a torsional damper is used to reduce vibrations in the torsional direction of the rotating shaft. The present invention relates to a torsional damper that absorbs vibrations and reduces vibration and noise in a rotating shaft and engine, and a method for manufacturing the same.

(Prior Art) Generally, when a rotating shaft such as the crankshaft of an internal combustion engine rotates, complex vibrations and noise are generated in the rotating shaft and the engine due to torque fluctuations in the engine, and furthermore, the rotating shaft This can lead to problems such as fatigue damage.

Therefore, in the past, in vehicle engines, etc., in addition to attaching a flywheel to the rotating shaft to smooth the torque,
As shown in Japanese Patent No. 15050, etc., a cylindrical torsional damper having a sub-vibration system (vibration absorber) is attached to the rotating shaft, and the natural angular frequency of the sub-vibration system is
By matching the angular frequency of the main vibration system (rotating shaft), the sub-vibration system resonates and the resonance amplitude in the torsional direction of the main vibration system is reduced, thereby reducing vibrations in the rotating shaft and engine.
So-called dynamic vibration absorbers have been used to try to absorb and reduce noise.

By the way, such a torsional damper generally includes a steel damper pulley with a boss fixed to a rotating shaft such as a crankshaft, and a steel damper pulley radially outward with respect to the damper pulley. and a cylindrical damper mass arranged concentrically, and a cylindrical elastic body made of an elastic material such as rubber as a buffer is interposed between the damper pulley and the damper mass. , will be realized.

And a torsional damper with this structure
By attaching, to a predetermined rotating shaft, an elastic body functioning as a sub-vibration system and a damper mass whose natural angular frequency matches the resonant frequency of the rotating shaft to which the damper is attached, Such a damper mass can effectively act as a damper (vibration absorber) against torsional vibrations generated on the rotating shaft, thereby reducing vibrations on the rotating shaft.

(Problem) However, since the damper pulley in a conventional torsional damper is made of steel, its weight is unavoidable.On the other hand, the rotating shaft of such a crankshaft is usually Since not only vibration in the bending direction (direction perpendicular to the axis) but also vibration in the bending direction (direction perpendicular to the axis) is generated at the same time, attaching such a damper to the rotating shaft greatly increases the weight of the rotating part. This increases the vibration of the rotating shaft in the direction perpendicular to the axis, and therefore, the rotating shaft and engine have a problem in that the vibration and noise caused by the vibration in the bending direction of the rotating shaft are significantly increased. In extreme cases, there was a risk that damage could occur.

(Solution Means) Here, the present invention has been made to solve such problems, and its features include a damper pulley attached to a predetermined rotating shaft, and a radius relative to the damper pulley. The above-mentioned damper mass includes a ring-shaped or cylindrical damper mass disposed concentrically outward in the direction, and an elastic body made of an elastic material such as rubber, interposed between the damper pulley and the damper mass. In such a torsional damper, the damper pulley is constructed from a resin molded product integrally provided inside the elastic body.

Furthermore, when manufacturing a damper pulley having such a structure, an elastic body made of an elastic material such as rubber is vulcanized and bonded to a predetermined thickness on the inner peripheral surface of a ring-shaped or cylindrical damper mass. After that, this mass/elastic body vulcanized adhesive is set in a prescribed injection mold, and the mass/elastic body is vulcanized.
A manufacturing method in which a damper pulley is injection molded by injecting a predetermined resin material inside an elastic body of an elastic body vulcanized adhesive, and a predetermined squeezing action is applied to the elastic body by injection pressure. It will be suitably adopted.

(Effect of the invention) Therefore, in the torsional damper having the structure according to the present invention as described above, since the damper pulley is formed of a resin material, the weight of the damper can be extremely effectively reduced. Therefore, when such a damper is attached to a predetermined rotating shaft, the increase in the vibration amplitude in the bending direction of the rotating shaft can be effectively suppressed, and the increase in the vibration amplitude on the rotating shaft is that large. This will not cause any problems, and the occurrence of breakage of the rotating shaft due to such vibrations can be extremely effectively prevented.

Furthermore, by manufacturing a torsional damper having such a structure according to the manufacturing method according to the present invention,
The manufacturing thereof can be carried out extremely well and easily. That is, according to the manufacturing method of the present invention, as the damper pulley is injection molded, effective squeezing action (pre-compression) is simultaneously applied to the elastic body disposed on the outer circumferential surface of the damper pulley, and the outer circumference of the damper pulley is Since the damper mass is integrally attached to the surface via the elastic body, the bonding strength of the elastic body can be improved, and its durability can be effectively improved.
There is no need for preliminary compression or installation processes such as press-fitting the damper mass into the damper pulley via an elastic body.
Therefore, the manufacturing process can be simplified, and a torsional damper with excellent performance can be easily manufactured.

(Example) Hereinafter, in order to clarify the present invention more specifically,
An embodiment of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show a longitudinal cross-sectional view and a front view of a torsional damper 10 which is constructed in accordance with the present invention and which also serves as a multi-pulley.

In these figures, 12 is a thermoplastic resin or thermosetting resin, glass fiber, carbon fiber, potassium titanate whiskers, etc., which is attached to a predetermined rotating shaft such as the crankshaft of an internal combustion engine and rotated therewith. The damper pulley is a resin molded product made of fiber-reinforced resin with the addition of fibers. A small-diameter cylindrical boss portion 1 that is integrally arranged with
6, a cylindrical portion 18 concentrically located on the outside of the boss portion 16 in the radial direction with a predetermined distance apart, and the boss portion 16.
1 for connecting the outer circumferential surface and the inner circumferential surface of the cylindrical portion 18; and a connecting portion 20 formed in the shape of a flange radially outward from the outer circumferential surface near one end in the axial direction of the boss portion 16. .

On both axial surfaces of the connecting portion 20 of the damper pulley 12, on the side from which the boss portion 16 projects (the right side in FIG. 1), the connecting portion 20 is connected to the outer peripheral surface of the boss portion 16 and the cylindrical portion. A substantially rectangular reinforcing rib 22 connected to the inner circumferential surface of
On the left side in the figure, a substantially triangular reinforcing rib 24 that connects the connecting portion 20 to the inner circumferential surface of the cylindrical portion 18 is
Multiple pieces on each surface (in this example,
9 pieces each) are formed. Note that these reinforcing ribs 22 and 24 are arranged alternately and at equal intervals on each surface of the connecting portion 20. In other words, the reinforcing ribs 22, 24 provided on different side surfaces are
They are alternately formed at positions shifted by a predetermined angle from each other so that they are not located at the same location in the circumferential direction of the connecting portion 20.

Also, arranged concentrically on the inner circumference of the boss portion 16,
A plurality of engagement grooves 32 (four in this embodiment) extending in the axial direction are formed on the outer peripheral surface of the metal sleeve 14 to be fixed. Each time the engaging convex portion 34 provided on the portion 16 is engaged, the metal sleeve 16 can be firmly fixed to the boss portion 16 and cannot be rotated relative to the boss portion 16.

Further, a steel damper mass 26 is concentrically arranged on the radially outer side of such a damper pulley 12.

This damper mass 26 has a substantially cylindrical shape having substantially the same length as the cylindrical portion 18 of the damper boot +712, and has a large number of grooves 28 formed on its outer peripheral surface. By winding a predetermined belt having a cross-sectional shape corresponding to the V-grooves 28 around the outer circumferential surface, the torsional damper 10 transfers the rotational driving force on the rotary shaft to which it is attached to a predetermined succeeding force. It is configured to function as a belt drive pulley for transmitting power to a member.

A rubber elastic body 30 having a cylindrical shape with a predetermined thickness is disposed between the damper mass 26 and the cylindrical portion 18 of the damper pulley 12, and by integrating them, a torsional A damper 10 is formed.

Therefore, a torsional damper with such a structure
10 is attached to a predetermined rotating shaft by a metal sleeve 14 and rotated together with the rotating shaft, and the elastic body 3 of the torsional damper 10
0 and the damper mass 26 function as a sub-vibration system, thereby absorbing and reducing the torsional vibration of the rotating shaft in the natural angular frequency range set in the sub-vibration system.

Furthermore, in this torsional damper 10, the damper pulley 12, which constitutes the main body of the mounting part, is made of a resin material, and therefore, compared to the conventional steel ones as described above, Its weight can be significantly reduced. Therefore, an increase in the rotational mass of the rotating shaft due to the installation of the torsional damper can be reduced, and thereby an increase in vibration amplitude in the bending direction of the rotating shaft can be effectively suppressed. The resulting damage to the rotating shaft can also be extremely effectively prevented.

Furthermore, in the torsional damper 10 in this embodiment, a large number of reinforcing ribs 2 are provided in the connecting portion 20.
4.26, there will be no strength problems even when applied to a relatively large damper, and in addition, these reinforcing ribs 24.2
6 are formed alternately at a predetermined distance from each other and are not located at the same location on both side surfaces of the connecting portion 20, so that deformation due to heat shrinkage of the resin after molding of the damper pulley 12 is avoided. Distortion can be effectively prevented, and variations in the injection speed of the resin within the mold can be suppressed, so that the desired damper pulley can be manufactured with good precision and quality.

By the way, when manufacturing a torsional damper having such a structure, for example, the following manufacturing method is preferably employed.

That is, as shown in FIG. 3, first, in the cavity formed by the fixed mold 36 and the movable mold 38 that constitute the injection mold, a mold is formed in advance by a vulcanization molding method or a post-adhesive method. , an elastic body 30 of a predetermined thickness is integrally vulcanized and adhered to the inner peripheral surface of the damper mass 26, in other words, a mass/elastic body vulcanized adhesive, and a metal sleeve 1.
4 are arranged and set concentrically at predetermined positions.

In addition, the elastic body 3 in such a mass/elastic body vulcanized adhesive
0 has annular grooves 40 on both end faces in the axial direction, and in the radially inner portion of the grooves 40, as shown in an enlarged view in FIG. A seal portion 42 having a predetermined width is formed around the entire circumference and seals by contacting the inner surface of the mold.

Annular convex portions 44 are formed on the fixed mold 36 and the movable mold 38 at positions corresponding to the grooves 40, respectively. Therefore, as described above, when the mass/elastic body vulcanized adhesive is set in the mold, the seal portion 42 of the elastic body 30 wraps around the convex portions 44 of the fixed mold 36 and the movable mold 38. It will come into contact with the mold surface.

Next, in this way, the elastic body 30 is placed at a predetermined position inside the elastic body 30.
As shown in FIG. 5, a predetermined resin material, particularly the above-mentioned fiber-reinforced resin material, is injected into a mold in which a damper mass 26 and a metal sleeve 14 are disposed. As a result, the desired damper pulley 12 is injection molded. At this time, due to the injection pressure of the resin material, pressure acts radially outward on the inner circumferential surface of the elastic body 30, so that a predetermined narrowing action is effective on the elastic body 30. As a result, the durability of the vulcanized adhesive surface of the elastic body 30 and its bondability to the damper pulley 12 can be improved. Note that when molding the damper pulley 12, the resin material is injected into the mold with a predetermined pressure.
Even when injection pressure is applied, the seal portions 42 and 42 formed at both ends of the elastic body 30 are in contact with the inner surface of the mold due to the annular convex portion 44 provided on the inner surface of the mold. The concave grooves 4 formed at both end portions of the elastic body 30 can be maintained well by the action of
Intrusion of resin material into the seal portions 42, 42
can be effectively prevented by

Therefore, according to such a manufacturing method, as the damper pulley 12 is injection molded, the elastic body 30 and the damper mass 26 are simultaneously disposed on the outer circumferential surface of the damper pulley 12, and the metal sleeve 14 is disposed on the inner circumferential surface of the damper pulley 12. Therefore, the conventional pre-compression and mounting process of press-fitting the damper mass into the damper pulley via an elastic body can be omitted.

Additionally, in conventional torsional dampers,
A metal sleeve is further vulcanized and bonded on the inner peripheral surface of the elastic body vulcanized and bonded to the damper mass, and the elastic body is press-fitted into the damper pulley through the metal sleeve, thereby exerting a squeezing action on the elastic body. However, if the manufacturing method of this embodiment is followed, the damper pulley 12 can be injection molded as described above. Sometimes, a predetermined squeezing action is applied to the elastic body 30 disposed on the outer circumferential surface of the elastic body 30, thereby improving durability and bondability. The number of parts can be effectively reduced without the need to use.

Therefore, by manufacturing the torsional damper 10 according to the manufacturing method according to the present invention, the manufacturing process can be effectively simplified, and a torsional damper with excellent performance can be easily manufactured. It can be said that

As described above, the torsional damper has a structure according to the present invention.
Although one embodiment and an example of the manufacturing method according to the present invention for manufacturing such a damper have been described in detail, these are literal illustrations, and the present invention
It is not intended to be construed as being limited to these specific examples.

For example, a torsional damper having a structure according to the present invention can be manufactured by a method other than the illustrative manufacturing method. A cylindrical elastic body is formed in advance, and the elastic body is press-fitted between the press-fit surfaces of a damper pulley and a damper mass coated with a suitable adhesive, and then they are bonded together by heating. It is also possible to manufacture by Especially 1. In a damper manufactured by such a manufacturing method, it is difficult to apply an effective squeezing action to the elastic body, but since the joining is done by vulcanization adhesive, the joining is difficult. The credibility of this can be sufficiently achieved, and the effects of the present invention as described above can be effectively achieved.

In addition, when injection molding the damper pulley with a specified resin material, in order to further improve the bonding properties, adhesive is attached to the contact surface of the elastic body and metal sleeve arranged in the mold to the resin. Applying agents etc.
This is effective in improving the effects of the present invention.

Furthermore, the torsional damper according to the present invention has a major feature in that the damper pulley is made of a resin molded product. The specific shape or structure is not limited to the above embodiments. For example, the shape and number of reinforcing ribs provided in the connecting portion are appropriately set depending on the shape and size of the damper, and it is also possible to form the damper without providing the reinforcing ribs. Further, a metal sleeve disposed on the inner circumferential surface of the boss portion of the damper pulley is not necessarily required.

Furthermore, in the above embodiments, the present invention was applied to a torsional damper that was also formed as a multiple V-pulley, but the present invention is not limited to such a structure. The present invention can also be effectively applied to a damper that is formed so as to function only as a vibration absorber on a rotating shaft to which it is attached, without providing such a groove.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. added based on the knowledge of those skilled in the art, and such embodiments are not limited to the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not depart from the spirit of the above.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view (corresponding to the I-1 cross section in FIG. 2) showing an embodiment of a torsional damper having a structure according to the present invention. FIG. 3 is a plan view of the torsional damper. Furthermore, FIG. 3 shows the mass/elastic body vulcanized adhesive and metal sleeve, which is one step in manufacturing the torsional damper shown in FIG. 1 using the manufacturing method according to the present invention. It is a vertical cross-sectional explanatory view showing a state set in an injection mold,
Figure 4 is an enlarged view of section A in Figure 3, and Figure 5 is an enlarged view of section A in Figure 3.
FIG. 3 is a vertical cross-sectional explanatory view corresponding to FIG. 3 for explaining a resin injection process when manufacturing the torsional damper shown in FIG. 1 using the manufacturing method according to the present invention. 10: Torsion damper 12: Damper pulley 14: Metal sleeve 16: Boss portion 18: Cylindrical portion 2 (l connection portion 22.24: Reinforcement rib 26: Dambar mass 30: Elastic body 36: Fixed type 38: Movable type Applicant Tokai Rubber Industry Co., Ltd. 21!1

Claims (6)

[Claims] (1) A damper pulley attached to a predetermined rotating shaft, a ring-shaped or cylindrical damper mass arranged radially outward and concentrically with respect to the damper pulley, and a combination of the damper pulley and the damper mass. The torsional damper includes an elastic body made of an elastic material such as rubber interposed therebetween, and the damper pulley is configured with a resin molded product integrally provided inside the elastic body. Features a torsional damper. (2) the damper pulley includes a boss portion to which the rotary shaft is attached, a cylindrical portion located on the radially outer side of the boss portion, and an annular plate-shaped connecting portion connecting the boss portion and the cylindrical portion; A suitable number of rib portions are arranged radially upright on at least one surface of the plate-like connecting portion and are connected to the plate-like connecting portion and the cylindrical portion and/or the boss portion. A torsional damper according to claim 1. (3) The damper pulley has a boss portion that is attached to the rotating shaft, and a predetermined metal cylindrical body is integrally provided on the inner circumference of the boss portion, and the rotating shaft is inserted into the metal cylindrical body. The torsional damper according to claim 1 or 2, wherein the torsional damper is fixed in place. (4) The torsional damper according to any one of claims 1 to 3, wherein the damper pulley is made of a resin molded product made of a fiber-reinforced resin material. (5) After vulcanizing and adhering an elastic body made of an elastic material such as rubber to a predetermined thickness on the inner circumferential surface of a ring-shaped or cylindrical damper mass, the mass/elastic body vulcanized adhesive is bonded to a predetermined thickness. The damper pulley is injection molded by setting the mass/elastic body in an injection mold and injecting a predetermined resin material inside the elastic body of the mass/elastic body vulcanized adhesive. A method for manufacturing a torsional damper, characterized by providing a predetermined throttling action. (6) The method for manufacturing a torsional damper according to claim 5, wherein the resin material is a fiber-reinforced resin.