JPH08135736A - Manufacture of torsional damper - Google Patents

Abstract

PURPOSE: To reduce cost by eliminating the need for a sleeve, and improve the durability of a torsional damper by applying an even precompression to an elastomer. CONSTITUTION: On press-working of a hub 1, an axially folded back and projected bent part 13 is formed between the outer diameter-cylindrical part 11 and the diametrical part 12 of the hub. After an elastomer 3 is vulcanized and adhesive bonded to between the outer diameter-cylindrical part 11 and a ring-like mass body 2, the bent part 13 is deformed so that it is spread toward the outer peripheral side by pressing a punch 6 into the outer diameter-cylindrical part 11 from the inner periphery of an open end part 11a while an axial load is applied to the bent part 13, and the outer diameter-cylindrical part 11 is evenly diametrically deformed and enlarged to give an even precompression to the elastomer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a torsional damper that absorbs torsional vibrations of a crankshaft of an engine, and more particularly to a method of manufacturing a torsional damper having a hub formed by pressing a metal plate.

[0002]

2. Description of the Related Art A torsional damper that effectively absorbs torsional vibrations (rotational vibrations) caused by rotation of an engine crankshaft is basically provided at the axial end of the crankshaft protruding from the crankcase of the engine. A hub to be mounted and an annular mass body arranged in proximity to this hub have a structure in which they are elastically connected via an elastomer,
The resonance system composed of the annular mass and the elastomer resonates in a phase opposite to the phase of the vibration displacement of the torsional vibration of the crankshaft input via the hub, thereby exerting a remarkable dynamic vibration absorbing effect. . 3 and 4 show a torsional damper manufactured by a conventional method. First, the torsional damper shown in FIG. 3 has an elastomer between a metal sleeve 102 and an annular mass body 103 arranged on the outer periphery thereof. After vulcanizing and bonding 104, the outer diameter tubular portion 101a of the hub 101 formed by press-molding a metal plate and the metal sleeve 102 are press-fitted to each other with an appropriate tightening margin, thereby pre-compressing the elastomer 104. The torsional damper shown in FIG. 4 directly vulcanizes the elastomer 113 between the outer diameter cylindrical portion 111a of the hub 111 formed by press-molding a metal plate and the annular mass body 112 arranged on the outer periphery thereof. After bonding, the radial portion 1 of the hub 111
While supporting 11b in the axial direction by a jig 114, the outer diameter tubular portion 1
Elastomer 113 is pre-compressed by squeezing 11a with punch 115 to expand and deform it.

[0003]

According to the above conventional manufacturing method, the following problems are pointed out. First, in the torsional damper shown in FIG. 3, the sleeve 102 is required to pre-compress the elastomer 104, which is high in cost. Further, in the torsional damper of FIG. 4, the punch 115 is used to form the outer diameter cylindrical portion 11 of the hub 111.
Even if the iron 1a is ironed, the outer diameter tubular portion 111a is larger than the end portion on the open side (left end in the figure) of the radial portion 111a.
Since the end portion on the b side is difficult to be deformed and the diameter is not uniformly expanded and deformed as shown by the broken line in the figure, the elastomer 113 cannot be given a required precompression for improving the durability, and the outer diameter cylindrical portion is not provided. As the diameter of 111a is expanded and deformed, the mounting surface of the radial portion 111b, which serves as a mounting surface for the crankshaft, is also subject to deformation.

The present invention has been made under the above circumstances, and its technical problems are to reduce the cost by reducing the number of parts and to improve the durability by uniformly pre-compressing the elastomer. To obtain a torsional damper that satisfies both of the improvements.

[0005]

As a means for effectively solving the above-mentioned technical problems, the present invention is concentrically arranged near the outer diameter cylindrical portion of a hub formed by press-molding a metal plate and its outer peripheral side. In the production of the torsional damper in which the elastomer is vulcanized and bonded between the arranged annular mass body, the outer diameter tubular portion and the radial portion extending from one end thereof to the inner periphery during press molding of the hub, A bent portion that is folded back in a protruding shape in the axial direction is formed between the outer diameter tubular portion and the open end portion on the opposite side to the radial portion while applying a load in the axial direction to the bent portion. The jig is press-fitted from the inner circumference to expand and deform the outer diameter tubular portion.

[0006]

According to the present invention, since the bent portion formed between the outer cylindrical portion and the radial portion of the hub made of a metal plate has a shape that is folded back into a protruding shape in the axial direction, By pressing the jig into the inner periphery of the outer diameter tubular portion while applying an axial load to the bending portion, the bending portion is deformed to extend to the outer peripheral side, and the outer diameter tube is pressed by the jig. The diametrical expansion of the shaped portion can be easily performed even on the radial direction side.
Therefore, the elastomer is pre-compressed uniformly between the outer diameter cylindrical portion of the hub and the annular mass body. Further, since the bent portion effectively absorbs the stress due to the radially expanded deformation of the outer diameter tubular portion,
The deformation of the radial portion of the hub due to this stress is prevented.

[0007]

1 shows a preferred embodiment of a method of manufacturing a torsional damper according to the present invention. Reference numeral 1 is a hub formed by press-molding a metal plate, and 2 is an outer diameter cylindrical portion 11 of the hub 1. Is a ring-shaped mass body that is concentrically arranged on the outer peripheral side and has a pulley groove 21 formed on the outer peripheral surface thereof. The elastomer 3 is vulcanized and adhered between the outer peripheral surfaces of the outer diameter tubular portion 11 of the hub 1 and the annular mass body 2 that face each other. When the hub 1 is press-molded, a bent portion 13 that is folded back into an axially protruding shape is formed between the outer diameter cylindrical portion 11 and the radial portion 12 that extends from one end to the inner periphery. To be done.

After the elastomer 3 is vulcanized and bonded, a pair of an open end portion (an end portion on the opposite side of the bending portion 13) of the outer diameter tubular portion 11 of the hub 1 and a tip portion of the bending portion 13 are provided. It is supported so as to be sandwiched by cylindrical pressing jigs 4 and 5, and while applying a required load in the axial direction by these pressing jigs 4 and 5, the open end portion 11a of the outer diameter tubular portion 11 is provided on the inner periphery thereof. Press in the punch 6 from. The punch 6 is an outer cylindrical portion 1 of the hub 1.
A jig for squeezing 1 from the inner peripheral side to expand and deform it,
Needless to say, the outer diameter thereof is appropriately larger than the inner diameter of the outer cylindrical portion 11.

That is, by press-fitting the punch 6, the outer diameter tubular portion 11 of the hub 1 is expanded and deformed, and a required compressive load is applied in the axial direction by the pressing jigs 4 and 5. As a result, since the bent portion 13 having the shape folded back in the axial direction is deformed so as to extend to the outer peripheral side, the end portion 11b of the outer diameter tubular portion 11 on the radial direction portion 12 side is unlikely to be expanded and deformed. Absent. Therefore, FIG.
As indicated by the chain double-dashed line, the outer diameter cylindrical portion 11 is expanded and deformed into a cylindrical shape having a uniform diameter dimension, and the elastomer 3 existing on the outer periphery thereof is uniformly pre-compressed with the annular mass body 2. Is
The tensile stress caused by the molding shrinkage after vulcanization is eliminated and the durability is enhanced. In addition, the stress generated by the expanded deformation of the outer diameter tubular portion 11 is absorbed by the expanded deformation of the bent portion 13, and the influence of the deformation on the radial direction portion 12 side due to this stress is slightly suppressed, so that it is illustrated. The deformation of the inner diameter portion of the radial portion 12, which serves as a mounting portion for the crankshaft that is not formed, is effectively prevented.

According to this embodiment, required precompression can be applied to the elastomer 3 without using the sleeve 102 as shown in the conventional example of FIG. 3, and the bent portion 13 is used when the hub 1 is press-molded. Which is formed into
Since a separate process for forming the bent portion 13 is not required,
Manufacturing costs can be reduced.

[0011]

According to the method of manufacturing the torsional damper of the present invention, the following effects are realized. (1) Since the bent portion between the outer cylindrical portion and the radial portion of the hub is deformed so as to extend to the outer peripheral side when the outer cylindrical portion is expanded and deformed by press fitting of the jig. The expansion deformation of the outer diameter tubular portion is not hindered on the radial direction side, and the elastomer can be uniformly pre-compressed to improve the durability. (2) Since the bent portion effectively absorbs the stress caused by the expanded deformation of the outer diameter tubular portion, the deformation of the radial portion of the hub, which is the attachment portion to the crankshaft, is prevented. (3) Since the sleeve is unnecessary, the number of parts is reduced, and no separate process is required for forming the bent portion, so that the manufacturing cost is reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a preferred embodiment of a method of manufacturing a torsional damper according to the present invention.

FIG. 2 is an explanatory view showing deformation of an outer diameter tubular portion and a bent portion of the hub according to the above embodiment.

FIG. 3 is an explanatory view showing a conventional method of manufacturing a torsional damper using a sleeve.

FIG. 4 is an explanatory view showing a conventional method for manufacturing a torsional damper in which the outer diameter cylindrical portion of the hub is expanded and deformed by a punch.

[Explanation of symbols]

 1 Hub 11 Outer Diameter Cylindrical Section 11a Open End 11b Radial Side End 12 Radial Section 13 Bend 2 Annular Mass 21 Pulley Groove 3 Elastomer 4,5 Pressing Jig 6 Punch (Jig)

Claims (1)

[Claims] 1. An elastomer (3) is provided between an outer diameter tubular portion (11) of a hub (1) formed by press-molding a metal plate and an annular mass body (2) concentrically arranged on the outer peripheral side thereof. In the production of a torsional damper having vulcanization bonded thereto, in the press molding of the hub (1), the outer diameter tubular portion (11) and a radial portion (1) extending from one end thereof to an inner periphery thereof.
A bent portion (13) folded back in an axially protruding shape is formed between the bent portion (2) and 2), and an axial load is applied to the bent portion (13) while the outer diameter tubular portion (11) is provided with the above-mentioned bent portion (13). The torsion is characterized in that the jig (6) is press-fitted from the inner circumference of the open end portion (11a) on the side opposite to the radial portion (12) to expand and deform the outer diameter tubular portion (11). Damper manufacturing method.