JP2001355711A - Resin pulley - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin pulley having high radiating effect for the heat inside of a rolling bearing and hardly producing a weld on its resin part. SOLUTION: A cylindrical part 31 of a heat radiation metallic plate 3 is exposed to an inner peripheral face of a boss part 21 of a resin pulley body 2, an inner flange part 31a is formed over the cylindrical part 31, and at least a part of a flange part 32 of the heat radiation metallic plate 3 is exposed to the external at a web part 23 of the pulley main body 2 in a state that it is closely kept into contact with both of an outer peripheral face 12a and an end face 12b of an outer ring 12 of a rolling bearing 1 at the cylindrical part 31 and the inner flange part 31a, whereby the heat radiation metallic plate 3 is brought into contact with the outer ring 12 with a large area to efficiently radiate the heat in the rolling bearing 1, and further the possibility of the occurrence of the weld can be reduced in injection molding by applying a structure that the boss part 21 and a rim part 22 of the pulley body 2 is connected to the web part 23 at its whole face without forming a discontinuous part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin pulley, for example, a resin pulley suitable for use as a tensioner or idler for a timing belt of an automobile engine.

[0002]

2. Description of the Related Art Pulleys used as tensioners and idlers for timing belts of automobile engines are known as:
In recent years, iron pulleys have been gradually shifted to resin pulleys for the purpose of weight reduction, reduction of sliding resistance with a belt, and cost reduction.

In this type of conventional resin pulley,
Basically, a structure is adopted in which a pulley body made of synthetic resin is directly integrated by injection molding so that the inner peripheral surface of the boss portion is in close contact with the outer peripheral surface of the outer ring of the rolling bearing. In such a structure, the heat generated by the rotation of the rolling bearing is difficult to escape due to the poor heat dissipation of the synthetic resin, and the temperature rise of the rolling bearing becomes large, and the life may be shortened. there were.

In order to solve such a problem, conventionally,
A resin pulley in which a metal plate for heat dissipation is inserted into a pulley body made of synthetic resin has been proposed (for example, Japanese Utility Model Application Publication No.
-32814).

In this proposed technique, the heat-dissipating metal plate inserted into the pulley body is exposed on the inner periphery of the boss portion of the pulley body and is in contact with a part of the outer peripheral surface of the outer ring of the rolling bearing. By providing a cutout portion of a molding resin layer between a plurality of reinforcing ribs on a web portion connecting a boss portion of the pulley body and a rim portion on the outer periphery, a metal plate for heat radiation is provided between the reinforcing ribs. It is exposed to the outside.

[0006]

In a resin pulley using a heat-dissipating metal plate based on the above conventional proposal, the heat-dissipating metal plate is formed on a part of the outer peripheral surface of the outer ring of the rolling bearing. However, there is a problem that the effect of radiating heat inside the rolling bearing is poor because the contact area is small and the contact area is small.

Further, in the above-mentioned proposed technology, a cutout portion is provided between the reinforcing ribs of the pulley body to expose the metal plate for heat radiation to the outside. The boss portion and the outer peripheral rim portion are substantially connected only by the respective reinforcing ribs. Therefore, regardless of whether the gate position is set to the boss portion side or the rim portion side during the injection molding, the mold is As a result, the molten resin poured into the rim portion or the boss portion flows through only the reinforcing ribs to the rim portion or the boss portion, so that a plurality of welds are generated in the rim portion and / or the boss portion, and the strength of the resin portion is weakened. is there.

The present invention has been made in view of such circumstances, and a main object of the present invention is to provide a resin pulley having a large effect of dissipating heat inside a rolling bearing. An object of the present invention is to provide a resin pulley having a structure in which the strength of a resin portion can be increased as compared with the related art while obtaining a large heat radiation effect by inserting a metal plate for heat radiation.

[0009]

In order to achieve the above-mentioned main object, a resin pulley according to the present invention integrates a resin pulley main body with an outer peripheral surface of an outer ring of a rolling bearing by injection molding. In the resin pulley, in which a metal plate for heat radiation is inserted into the pulley body, the metal plate for heat radiation is exposed on the inner peripheral surface of the boss portion of the pulley body, and the outer ring of the rolling bearing While being pressed into contact with the outer peripheral surface and the end surface, the part integrated with the web part of the pulley main body reaches the vicinity of the rim part of the pulley main body in a state where it is partially exposed to the outside. (Claim 1).

Further, the invention according to claims 2 and 3 achieves the above-mentioned other object in addition to the above.
In the invention according to claim 2, the portion of the heat-dissipating metal plate integrated with the web portion is bent into a corrugated plate, one side of which is in close contact with the web portion, and the other surface is It is characterized by being exposed to the outside.

According to a third aspect of the present invention, a plurality of arms project radially from a portion where the heat-dissipating metal plate is press-fitted into the outer race, and each arm has a thickness direction. Twisted in the direction perpendicular to the axial direction of the pulley,
In addition, it is characterized by being integrated with the web portion of the pulley body in a state where a through hole is formed in the center portion thereof, and having both edges of each arm portion exposed to the outside.

The present invention is intended to effectively radiate the heat generated by the rotation of the rolling bearing by increasing the contact area of the metal plate for heat dissipation inserted into the resin pulley body with the rolling bearing.

In other words, in the present invention, the heat-dissipating metal plate, which is inserted into the resin-made pulley body and at least a part of which is exposed to the outside at the web portion, is provided on the inner peripheral surface of the boss portion of the pulley body. Since it is press-fitted into the outer ring of the rolling bearing while being exposed and in contact with both the outer peripheral surface and the end surface of the outer ring, the contact area between the outer ring and the metal plate for heat dissipation is large, and the heat inside the rolling bearing is reduced. Heat can be dissipated efficiently.

Further, as in the invention according to claim 2, one side of the heat-dissipating metal plate is brought into close contact with the web portion of the pulley body, and the other surface is exposed to the outside. By having a structure bent into a corrugated plate, the strength of the metal plate can be improved to increase the strength of the pulley as a whole, and the resin pulley main body can be improperly mounted on the web as in the above-mentioned proposal. Since there is no continuous portion and the entire boss and rim are connected, weld is unlikely to occur during injection molding, and the metal plate is exposed almost entirely to the outside on one side of the web portion of the pulley body, and the heat is dissipated. The effect can be increased.

On the other hand, as in the invention according to claim 3, a plurality of arms are radially extended from a portion in which a metal plate for heat dissipation is pressed into contact with the outer ring at the outer peripheral surface and the end surface. Each arm portion of the metal plate is inserted into the pulley body so that the arm portion has a shape in which the plate thickness direction is orthogonal to the axial direction, that is, a shape in which a through hole is formed at the center portion by being twisted by about 90 °, so that each arm portion of the metal plate is pulled out. Since the strength of the pulley main body can be improved by playing the role of the reinforcing rib of the main body, the resin of the pulley main body enters the holes formed in the respective arm portions and is integrated with the respective arm portions, While the metal plate and the resin are firmly integrated,
As described above, since there is no discontinuous portion in the web portion, weld is unlikely to occur during injection molding.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along line AA, and FIG. 3 is an enlarged sectional view taken along line BB of FIG. This embodiment shows an example in which the invention according to claim 2 is applied.

The rolling bearing 1 is disposed in an inner ring 11 and an outer ring 12, and in an annular space formed therebetween, and mainly includes a plurality of rolling elements 13, each of which is held by a retainer (not shown). It is held at regular intervals in the circumferential direction.
Both ends in the axial direction of the annular space between the inner ring 11 and the outer ring 12 are sealed by a seal member (not shown), and grease is sealed therein.

The pulley body 2 is made of synthetic resin and has a structure in which a central boss portion 21 and an outer rim portion 22 are connected by a web portion 23. A metal plate 3 for heat radiation is inserted into the pulley body 2. It is integrated by molding.

The heat-dissipating metal plate 3 includes a cylindrical portion 31 exposed on the inner peripheral surface of the boss portion 21 of the pulley body 2 and a cylindrical portion 31 thereof.
Of the pulley body 2
The inner portion 31a is formed on the other end of the cylindrical portion 31 so as to bend inward and bend. The flange portion 32 is bent into a corrugated plate shape as shown in FIG.

The metal plate 3 for heat radiation has an inner peripheral surface of the cylindrical portion 31 and an outer peripheral surface 12 of the outer ring 12 of the rolling bearing 1.
a, and the inner flange portion 31a is press-fitted into the outer ring 12 in a state in which the inner flange portion 31a is also in close contact with one end surface 12b of the outer ring 12. Further, with respect to the pulley body 2, the outer peripheral surface of the cylindrical portion 31 is in close contact with the boss portion 21, and one surface of the corrugated flange portion 32 is in close contact with the web portion 23. The other surface of the portion 32 is entirely exposed to the outside. The pulley body 2
In the web portion 23, reinforcing ribs 24 are formed on the surface opposite to the side on which the heat-dissipating metal plate 3 is arranged at regular intervals in the circumferential direction as necessary.

In the above-described embodiment, the heat-dissipating metal plate 3 formed into the above-mentioned shape by press molding or the like is pressed into the outer ring 12 of the rolling bearing 1 and the whole is injected into the pulley body 2. It can be obtained by injecting a resin into the mold while positioning it in the mold.

According to this embodiment, the heat dissipating metal plate 3
Are the outer peripheral surface 12a of the outer race 12 of the rolling bearing 1 and the one end surface 1
2b, the contact area with the outer ring 12 is large, and the flange portion 32 is exposed to the outside over substantially the entire surface of one side of the web portion 23 of the pulley body 2. Rolling bearing 1
The heat inside can be radiated with high efficiency.

Further, since the flange portion 32 is bent in a corrugated shape, the strength of the metal plate 3 for heat radiation itself is high, and the synthetic resin of the pulley body 2 adheres to the metal plate 3 for heat radiation over a large area. As a result, the two are firmly integrated with each other, and the overall strength is high. Then, the synthetic resin of the pulley body 2 includes the boss 21 and the rim 2
2 is entirely connected at the web portion 23, so that a plurality of welds do not occur at the time of injection molding as in the resin pulley based on the above-mentioned proposal which is connected only by a plurality of reinforcing ribs. Can greatly reduce the possibility of the occurrence of weak points.

Although the above embodiment shows an example in which the invention according to claim 2 is applied to a flat pulley, the invention according to claim 2 is equally applicable to a V pulley. FIG. 4 shows an axially parallel sectional view of FIG. The example of FIG. 4 is different only in that a plurality of V-grooves are formed in the rim portion 22 of the pulley body 2 and in that the shape of the web portion 23 connecting the rim portion 22 and the boss portion 21 is different. Unlike the embodiment, the cylindrical portion 31 and the inner flange portion 31a of the heat-dissipating metal plate 3 bent into a corrugated plate are press-fitted in a state of being in close contact with the outer peripheral surface and one end surface of the outer ring 12 of the rolling bearing 1. In addition, the structure of the other essential parts, including the fact that the flange part 32 is exposed to the outside on one side of the web part 22, is completely the same as the previous example, and the operation and effect are also the same as the previous example. is there.

Next, an embodiment of the invention according to claim 3 will be described. FIG. 5 shows a front view thereof, and FIG. 6 shows an AA enlarged sectional view thereof.

The feature of this embodiment lies in the metal plate 30 for heat radiation.
The cylindrical portion 301 exposed on the inner peripheral surface of the boss portion 201 and the inner flange portion 3 inwardly bent at one end thereof.
01a and a plurality of arm portions 302 extending radially outward from the cylindrical portion 301. Each arm 302
Are formed to project from the periphery of the cylindrical portion 301 at a constant angle in the circumferential direction, and each of these arm portions 30 is formed.
Numeral 2 is twisted at a base portion with respect to the cylindrical portion 301, and its thickness direction is along a direction orthogonal to the axial direction of the pulley. That is, as shown in FIG. 7, a main part front view of a semi-molded product of the heat-dissipating metal plate 30, the metal plate
After being press-formed into a shape as shown in FIG. 7 having a plurality of arm portions 302, each arm portion 302 is twisted by 90 ° as indicated by an arrow in the figure. Each arm 302 has a through-hole 302a formed at the center thereof.

In the metal plate 30 for heat dissipation, the cylindrical portion 301 and the inner flange portion 301a are in close contact with the outer peripheral surface 12a and the one end surface 12b of the outer ring 12 of the rolling bearing 1 as in the previous embodiment. In this state, the outer ring 12 is press-fitted. The boss portion 201 and the rim portion 20 of the pulley main body 20 are connected to the pulley main body 20 in a state in which the vicinity of both edges of each arm portion 302 is exposed to the outside.
2 are integrated with each other while being inserted into the web portion 203 connecting the pulleys 2 and the synthetic resin of the pulley main body 20 has entered the through holes 302 a formed in each arm portion 302.

Also in the embodiment having the above structure, the heat-dissipating metal plate 30 is formed into a required shape including the torsion bending of each arm portion 302 thereof, and is then pressed into the outer ring 12 of the rolling bearing 1 and pressed. It can be manufactured by positioning in a mold and molding the pulley body 20 by injection molding of a synthetic resin.

According to the above embodiment, similarly to the previous embodiment, the heat radiating metal plate 30 is connected to the outer ring 1 of the rolling bearing 1.
2 is press-fitted into each of the outer peripheral surface 12a and the one end surface 12b in close contact with each other, so that the contact area is large, so that the heat inside the rolling bearing 1 can be effectively radiated.

Each of the arm portions 3 of the metal plate 30 for heat radiation is
02 are inserted into the web 203 of the pulley body 20 at a certain angle, and are integrated with each other in a state where the synthetic resin enters the through holes 302a formed in the respective arm portions 302. At the same time as the synthetic resin forming the heat sink 20 and the metal plate 30 for heat radiation are firmly integrated, the strength at the position where each arm portion 302 is disposed increases, and this portion substantially serves as a reinforcing rib. ,
In particular, there is no need to separately form a reinforcing rib. Also in this embodiment, the boss 201 of the pulley body 20 is also provided.
And the rim 202 are connected through the entire web 203, so that there is no possibility that a plurality of welds are generated in the boss 201 and / or the rim 202 during the injection molding and the resin strength is reduced.

The invention according to claim 3 can of course be applied not only to the above-described V pulley but also to a flat pulley.

[0032]

As described above, according to the present invention, the heat-dissipating metal plate inserted into the resin-made pulley body is brought into close contact with both the outer peripheral surface and the end surface of the outer ring of the rolling bearing. The heat inside the rolling bearing can be efficiently guided to the metal plate for heat dissipation, and the heat can be effectively dissipated from the portion of the web portion of the pulley body that is exposed to the outside.

Further, as in the second aspect of the present invention, the heat-dissipating metal plate is protruded in a flange shape from a cylindrical portion which is press-fitted into the outer ring of the rolling bearing so as to be substantially entirely formed on one surface of the web portion of the pulley body. In addition to the above effects, in addition to the above effects, the strength of the heat dissipating metal plate itself is increased, and a high-strength resin pulley is obtained. Since the boss portion and the rim portion are entirely connected by the web portion, it is possible to greatly reduce the possibility that a plurality of welds are generated on the boss portion and / or the rim portion as in the related art.

Further, as in the invention according to claim 3, the heat-dissipating metal plate has a plurality of arms projecting radially from a cylindrical portion which is pressed into the outer ring of the rolling bearing, and each arm portion has a plate thickness. By adopting a structure in which the direction is orthogonal to the pulley axis direction and a through hole is formed in the center of each arm, the degree of adhesion between the metal plate for heat dissipation and the synthetic resin is improved, The arrangement position of the part substantially serves as a reinforcing rib, eliminating the need for forming a separate reinforcing rib on the pulley body, and at the same time greatly increasing the possibility of welding occurring during injection molding as described above. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment to which the invention according to claim 2 is applied.

FIG. 2 is an enlarged sectional view taken along line AA of FIG.

FIG. 3 is an enlarged sectional view taken along line BB of FIG. 1;

FIG. 4 is an axially parallel sectional view of another embodiment of the invention according to claim 2;

FIG. 5 is a front view of an embodiment to which the invention according to claim 3 is applied.

FIG. 6 is an enlarged sectional view taken along line AA of FIG. 5;

7 is a main part front view of the semi-molded product before the arm portion 302 of the metal plate 30 for heat radiation in the embodiment of FIG. 5 is twisted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling bearing 11 Inner ring 12 Outer ring 12a Outer peripheral surface 12b End surface 13 Rolling element 2,20 Pulley body 21,201 Boss 22,202 Rim 23,203 Web 24 Reinforcing rib 3,30 Heat dissipating metal plate 31,301 Cylindrical Part 31a, 301a Inner flange part 32 Flange part 302 Arm part 302a Through hole

Claims (3)

[Claims] 1. A resin pulley in which a resin pulley body is integrated with an outer peripheral surface of an outer ring of a rolling bearing by injection molding, and a metal plate for heat radiation is inserted into the pulley body. Metal plate is exposed on the inner peripheral surface of the boss portion of the pulley main body, is pressed into the outer ring of the rolling bearing in contact with the outer peripheral surface and the end surface thereof, and A resin pulley extending to a vicinity of a rim portion of the pulley body in a state where at least a part of a portion integrated with the web portion is exposed to the outside. 2. A portion of the heat-dissipating metal plate integrated with the web portion is bent into a corrugated plate, one surface of which is in close contact with the web portion, and the other surface is exposed to the outside. The resin pulley according to claim 1, wherein 3. A plurality of arms project radially from a portion of the heat-dissipating metal plate pressed into the outer race, and each arm has a plate thickness direction orthogonal to the axial direction of the pulley. To be integrated with the web of the pulley body with a through hole formed in the center of the pulley, and both edges of each arm are exposed to the outside. The resin pulley according to claim 1, wherein: