JPH0740115Y2 - Rotating body made of resin for power transmission - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotating body for power transmission such as gears and pulleys, and more specifically, to a ring-shaped resin molding portion integrally provided with a power transmission portion on an outer peripheral portion. The present invention relates to a resin-made rotating body having a structure in which a metal bush is integrally fixed to a peripheral portion.

(Background Art) In recent years, attempts have been made to change the constituent material from metal to resin in a power transmission rotating body such as a gear and a pulley in order to reduce vibration and noise and reduce weight. There is. However, if the rotating body is made entirely of resin, defects such as chipping are likely to occur in the inner peripheral portion where stress is concentrated. Therefore, in general, in order to avoid such a defect, the outer peripheral side where the power transmission unit is provided is It is practiced that only the part is made of fiber reinforced resin and the part on the inner peripheral side is made of a metal bush.

By the way, in the case of a resin rotating body whose inner peripheral part is composed of a metal bush, when the operating environment is severe and the environmental temperature changes greatly, the thermal expansion of the metal bush and the resin molding part Due to the difference in the coefficient, the metal bush and the resin molding part are separated, a gap is created between the metal bush and the resin molding part, and the resin molding part falls off the metal bush or There is a risk that the formed part will idle around the metal bush.

Therefore, in this type of resin-made rotating body, a predetermined protrusion is provided on the outer peripheral surface of the metal bush, and the protrusion is inserted into the resin molding portion, and even if the metal bush and the resin molding portion are Even if there is a gap between them, the resin molded part does not fall off from the metal bush or the resin molded part does not run idle with respect to the metal bush due to the protrusion engaging with the resin molded part. It is generally done.

However, conventionally, the above-mentioned projection provided on the outer peripheral surface of the metal bush has a function of preventing relative rotation between the resin molded portion and the metal bush, and the axial direction of the resin molded portion and the metal bush. However, it was not provided with the function of suppressing the generation of the gap between the metal bush and the resin molding portion. And therefore, in this type of conventional resin-made rotating body, there is still a problem that a gap easily occurs between the metal bush and the resin molded portion, and the metal bush and the resin molded portion Due to the gap between them,
The problem that the mechanical strength of the resin-molded portion is lowered and the durability of the rotating body is lowered is still inherent.

Further, in JP-A-58-128563, in a double-molded resin gear, by providing a projecting portion projecting from one resin portion into the other resin portion, a gap or a gap generated between the two resin portions is provided. A method for solving the problem caused by the occurrence of the problem has been clarified. Further, in Japanese Utility Model Publication No. 35-14623, it is necessary to fill the resin forming the peripheral portion into a plurality of holes provided in the protruding portion from the vehicle body. Although a pulley structure in which the bondability between the vehicle body and the resin peripheral portion is improved has been clarified, it has been difficult to say that even with these measures, it is still sufficient.

(Problem to be Solved) Here, the present invention has been made in view of such circumstances, and the problem to be solved is that the metal bush is provided on the inner peripheral portion of the resin molding portion as described above. In a resin-made rotating body having a structure in which are integrally fixed to each other, it is possible to more favorably prevent peeling between the resin-molded portion and the metal bush, and consequently the occurrence of a gap between the resin-molded portion and the metal bush. Then, it is an object of the present invention to provide a technique for more effectively suppressing a decrease in mechanical strength of a resin molded portion due to the occurrence of such a gap, and thereby more advantageously suppressing a decrease in durability of a rotating body.

(Solution) In order to solve such a problem, in the present invention, an annular resin molding portion integrally provided with a power transmission portion on the outer peripheral portion and an inner peripheral portion of the resin molding portion are integrally formed. A metal bush fixedly provided, and is embedded in the resin molded portion at an axially intermediate portion of an outer peripheral surface portion of the metal bush covered by the resin molded portion. In a resin-made rotating body for power transmission, which has a structure in which a plurality of annular protrusions are provided and a plurality of predetermined protrusions are provided on the outer peripheral surface of the annular protrusion at predetermined intervals in the circumferential direction. , With respect to the annular convex portion of the metal bush, an annular groove opening on at least one of the side surfaces of the convex portion, and a side portion of the convex portion penetrating in the axial direction, mutually predetermined in the circumferential direction. Form at least one of a plurality of through holes located at intervals. In addition to the tightening, the projection formed on the outer peripheral surface of the annular convex portion is formed into a fan-shaped cross-sectional shape whose circumferential dimension increases toward the tip side.

(Operation) In such a power transmission resin rotary body, in the case where the annular groove is formed in the annular convex portion on the outer peripheral surface of the metal bush, in the resin molded portion filled in the annular groove, In the case where the resin portion or the through hole in the axial direction is formed in the annular convex portion, the resin portion of the resin molding portion filled in the through hole is further formed into the annular groove on the annular convex portion. In the case where both the through hole in the axial direction and the through hole in the axial direction are formed together, the resin portion of the filling molding portion filled in the annular groove and the through hole respectively has a radial direction from the metal bush of the resin molding portion. In addition to having an undercut shape with respect to the outward peeling direction, the resin portion filled between the projections of the fan-shaped cross section protruding on the outer peripheral surface of the annular convex portion also has an effective undercut shape. . Therefore, in addition to the resin portion filled in at least one of the annular groove and the through hole, the resin portion filled between the projections of the fan-shaped cross section has a biting action on the metal bush, and thus the resin formed portion is made of metal. Peeling from the bush is suppressed even better, and in turn, the formation of a gap between the resin molded portion and the metal bush is further suppressed.

And, in such a resin-made rotating body according to the present invention,
Even if the resin molded part is separated from the metal bush and a gap is created between the resin molded part and the metal bush, the relative distance between the resin molded part and the metal bush in the axial direction. The movement, and hence the detachment of the resin molded part from the metal bush, can be prevented satisfactorily based on the presence of the circumferential annular projection protruding on the outer peripheral surface of the metal bush. Relative movement in the circumferential direction of the metal bush with the metal bush, the occurrence of the idling phenomenon of the resin molding and the metal bush, based on the existence of the projection of the fan-shaped cross-section protruding on the outer peripheral surface of the annular convex portion,
It can be prevented even better.

(Example) In order to clarify the present invention more concretely,
Several examples (including embodiments of the present invention) of a driven V-ribbed pulley for power steering, which is used by being attached to a drive shaft of a vane pump of a power steering of an automobile, will be described in detail with reference to the drawings.

First, FIG. 1 is a vertical cross-sectional view showing a reference example of a driven V-ribbed pulley for power steering for facilitating the understanding of the present invention, and FIG. 2 is a front view thereof. As is clear from the above, the V-ribbed pulley of this reference example has a V-ribbed groove 2 as a power transmission portion on the outer peripheral portion.
A V-ribbed pulley main body 4 made of resin integrally provided with a metal bush 6 integrally fixed to the inner peripheral portion of the V-ribbed pulley main body 4. The V-ribbed pulley of this reference example is attached to the drive shaft of the vane pump of the power steering in the inner hole of the metal bush 6, while the V-ribbed belt is hung on the V-ribbed groove 2 on the outer periphery of the V-ribbed pulley body 4. It has been handed over and used. Here, the V-ribbed pulley main body portion 4 constitutes an annular resin molding portion.

Here, the V-ribbed pulley main body 4 is made of a fiber-reinforced resin material such as phenol resin mixed with a short fiber filler. Here, the V-ribbed pulley main body 4 is composed of four or more split molds. By molding using a molding die, the V-ribbed groove 2 on the outer peripheral portion is integrally formed by molding. Then, the connecting resin portion 9 between the formation portion 5 of the V-ribbed groove 2 and the embedded portion 7 of the bush 6 is made thinner than those portions, so that the molding material can be reduced and the weight thereof can be reduced. In addition, in order to compensate for the reduction in mechanical strength due to the thinning of the connecting resin portion 9, the pump side surface of the connecting resin portion 9 located on the vane pump side of the power steering is connected to the embedded portion 7 of the push 6 from the embedded portion 7. A plurality of (8 in this case) reinforcing ribs 8 are integrally formed in a state of radially extending toward the formation portion 5 of the ribbed groove 2.

On the other hand, the metal bush 6 integrally fixed to the inner peripheral portion of the V-ribbed pulley main body 4 is provided on the vane pump side of the inner peripheral surface thereof as shown in FIGS. 1 to 3. A half length portion is a smooth cylindrical surface, and an involute spline 12 is formed on the remaining substantially half length portion. And such a bush 6
The involute spline formed on the drive shaft of the vane pump is fitted and attached by the involute spline 12, and the rotational force transmitted from the engine via the V-ribbed belt is transferred to the involute spline. It is adapted to be transmitted to the drive shaft of the vane pump by fitting.

Further, as shown in FIG. 1 and FIG. 3, on the outer peripheral surface of the bush 6, the bush 6 is located at an intermediate portion in the axial direction of the attachment portion to which the V-ribbed pulley body portion 4 is attached. , An annular convex portion 14 extending in the circumferential direction is integrally projected, and a large number of gear teeth 16 are integrally projected on the outer peripheral surface of the convex portion 14 at a constant pitch in the circumferential direction. Has been. Further, here, a pair of annular grooves 18, 18 having a predetermined depth are formed in a state of opening on both side surfaces of the annular convex portion 14 formed on the outer peripheral surface of the bush 6, respectively. In a state in which the annular convex portion 14 having the annular grooves 18, 18 and the gear teeth 16 is projected into the V-ribbed pulley main body portion 4 and embedded integrally, the bush 6 is formed on the inner peripheral portion of the V-ribbed pulley main body portion 4. It is fixedly attached to one body.

In the V-ribbed pulley having such a structure, the V-shaped pulley is formed in a pair of annular grooves 18, 18 formed in the annular convex portion 14 on the outer peripheral surface of the metal bush 6 with a part of the constituent resin filled in the V-shaped pulley.
The ribbed pulley main body 4 is configured. Therefore, the resin portion filled in the annular grooves 18, 18 is V
The ribbed pulley main body 4 has an undercut shape in the direction of radial outward separation from the metal bush 6,
Moreover, as shown in FIG. 4, a part of the reinforced short fibers 19 is arranged so as to extend over the resin in the undercut-shaped portion (the resin in the annular groove 18) and the resin located outside thereof. Therefore, the V-ribbed pulley main body 4 and the metal bush 6 are separated from each other due to the difference in thermal expansion coefficient due to the biting action of the resin portion filled in the annular grooves 18, 18 with respect to the metal bush 6. Is suppressed,
As a result, it is possible to suppress the formation of a gap between the V-ribbed pulley body 4 and the metal bush 6.

Further, here, the gear teeth 16 are formed on the outer peripheral surface of the annular convex portion 14 projectingly provided on the outer peripheral surface of the bush 6.
Of the V-ribbed pulley main body 4 are filled with resin that forms the valleys 22 between adjacent ones of the two, so that the resin and the gear teeth 16 filled in the valleys 22 The relative rotation between the V-ribbed pulley body 4 and the metal bush 16 is prevented to some extent based on the engagement with the.

Another example of the V-ribbed pulley similar to the above reference example will be described in detail with reference to FIGS. 5 to 7.

That is, in these drawings, reference numeral 26 denotes a metal bush, which corresponds to the metal bush 6 of the reference example, and has an annular convex portion 14 similar to the metal bush 6 of the reference example and a pair. The annular grooves 18 and 18 are provided. But,
In the metal bush 26 of the present reference example, unlike the metal bush 6 of the above reference example, the gear teeth 16 as protrusions provided on the outer peripheral surface of the annular convex portion 14 are provided in the axial direction in the axial direction. The gear teeth 16 are divided and arranged in two rows, and an annular valley portion 28 extending in the circumferential direction is formed between the gear teeth 16 arranged and formed in the two rows. And those gear teeth
Twill knurls 30 are formed so as to be inclined with respect to the tip end surface of the shaft 16 by a predetermined angle in the axial direction.

Further, in the metal bush 26 of the present reference example, also on the bush outer peripheral surface sandwiching the annular convex portion 14 in the axial direction, respectively,
The knurls 32, 32 are formed in a state parallel to the axial direction. And, here, the annular groove 18, 1 of the annular convex portion 14
A plurality of (here, eight) through-holes 20 are formed so as to penetrate the annular convex portion 14 in the axial direction at a predetermined distance in the circumferential direction at the formation site of 8. ,
With respect to the outer peripheral surface of the metal bush 26 having such a structure,
As shown in FIG. 7, in a state in which only the minute width dimension portion of the end portion on the vane pump side is exposed, the resin molding is performed so as to include the annular convex portion 14 in the same manner as the reference example. The V-ribbed pulley main body 4 as a portion is attached to form a V-ribbed pulley.

Therefore, in such a V-ribbed pulley, the same effect as that of the V-ribbed pulley of the above-described reference example can be obtained based on the existence of the annular convex portion 14, the two gear teeth 16, 16 and the pair of annular grooves 18, 18. Of course, since the resin filled in the through hole 20 of the annular convex portion 14 also has an undercut shape in the peeling direction, the presence of the through hole 20 also causes the V-ribbed pulley main body 4 and the metal bush. The peeling from 26 and the formation of gaps between them can be suppressed to some extent.

Moreover, in the present reference example, the resin filled in the annular valley portion 28 between the gear teeth 16 and 16 is engaged with the side surface of the gear teeth 16 and 16, so that the metal of the V-ribbed pulley main body 4 is Since the pulling resistance from the bush 26 made in the axial direction is further improved, there is an advantage that the V-ribbed pulley body 4 is prevented from coming off the bush 26 made of metal, and the existence of the knurls 30, 32, 32 is provided. Thus, there is an advantage that the adhesiveness or affinity of the resin of the V-ribbed pulley main body 4 to the metal bush 26 is improved.

The present invention enjoys the advantages shown in these reference examples,
By changing the shape of the protrusion that is provided on the outer peripheral surface of the annular convex portion 14, it is intended to further suppress the peeling from the metal bush of the resin molded portion, and the like.
It is shown in FIGS.

That is, the metal bush 34 shown in those figures.
In that, in that it has the annular convex portion 14, a pair of annular grooves 18, 18 and a plurality of through holes 20, although it has a structure similar to the metal bush 26 of the reference example, On the outer peripheral surface of the annular convex portion 14, unlike the metal bush 26 of the reference example, there are a plurality of (here, eight) projections 38 having a fan-shaped cross section whose circumferential dimension is larger toward the tip side. In, they are projected from each other at a constant interval. Then, cross knurls 40 that intersect diagonally with respect to the tip surfaces of the protrusions 38 are formed.
In addition, knurls 32, 32 similar to the metal bush 26 of the reference example are formed on the outer peripheral surface of the bush sandwiching the annular convex portion 14.

Therefore, if the V-ribbed pulley main body 4 is attached to the outer peripheral surface of the metal bush 34 having such a structure to form the V-ribbed pulley as in the reference example, the annular grooves 18, 18, the through holes 20, and the The resin portion of the V-ribbed pulley main body portion 4 filled in the valley portion 42 between the adjacent protrusions 38, 38 is below the peeling direction of the V-ribbed pulley main body portion 4 from the metal bush 34 in the radial outward direction. Because of the cut shape, as compared with the V-ribbed pulley that employs the metal bush 26, it has a biting effect on the protrusions 38, 38 of the resin portion filled in the valleys 42 between the adjacent protrusions 38, 38. Of the V-ribbed pulley main body 4 from the metal bush 34, and thus the V-ribbed pulley main body 4 and the metal bush 34.
The generation of a gap between the V-ribbed pulley main body 4 and the V-ribbed pulley main body 4 is suppressed more effectively.
It is possible to prevent the mechanical strength of the V-ribbed pulley main body 4 and the durability of the V-ribbed pulley from being reduced due to the gap between the metal bush 34 and the metal bush 34.

In the metal bush 34, as in the case of the metal bush 26, due to the existence of the knurls 40, 32, 32, the adhesion or affinity between the V-ribbed pulley body 4 and the metal bush 34 is improved. Therefore, V
Peeling of the ribbed pulley body 4 from the metal bush 34 can be effectively suppressed.

Further, when such a metal bush 34 is used,
The V-ribbed pulley main body 4 rotates in the circumferential direction relative to the metal bush 34 solely based on the resin located in the valley portion 42 between the adjacent protrusions 38, 38 engaging with the protrusion 38. Will be prevented.

The representative embodiment of the present invention has been described in detail above in comparison with the reference example. However, this is a literal example, and the scope of the present invention is not limited to such a specific example. Within the scope of not departing from, various changes, modifications,
It goes without saying that the invention can be carried out in an improved manner.

For example, in the above-described embodiment, with respect to the annular convex portion 14 provided on the outer peripheral surface of the metal bush, a pair of annular grooves is provided.
Although 18,18 are formed, only one of the annular grooves 18,18 may be provided, and when a plurality of through holes 20 are formed in the annular convex portion 14, such Annular groove 18
Can be omitted.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the V-ribbed pulley in which the V-ribbed groove 2 is provided on the outer peripheral portion of the resin molded portion has been described. However, gear teeth are integrally provided on the outer peripheral portion of the resin molded portion. The present invention can also be applied to other resin-made rotating bodies such as gears.

(Effect of the Invention) As is apparent from the above description, according to the resin rotating body according to the present invention, the presence of the annular groove or the through hole formed in the annular convex portion of the metal bush, or the presence of both of them. In addition, on the outer peripheral surface of the annular convex portion, due to the existence of the projections of the fan-shaped cross section, which are formed at a predetermined interval in the circumferential direction and whose circumferential dimension is larger toward the tip side, the coefficient of thermal expansion varies. Peeling of the resin molded portion from the metal bush, and hence the occurrence of a gap between the resin molded portion and the metal bush, can be suppressed even better, therefore, those resin molded portion and the metal bush and The mechanical strength of the resin-molded portion is further suppressed from being reduced due to the gap between the two, and the durability of the rotating body is significantly improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a V-ribbed pulley according to a reference example for facilitating the understanding of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a front view thereof. FIG. 7 is a front view showing the metal bush of the V-ribbed pulley of FIG.
FIG. 4 is a cross-sectional explanatory view of a main part showing a distribution state of reinforcing short fibers of the V-ribbed pulley of FIG. 1. FIG. 5 is a perspective view showing another example of a metal bush that can be used in a V-ribbed pulley according to the same reference example as described above, FIG. 6 is a front view thereof, and FIG. FIG. 6 is a view corresponding to FIG. 4 of a V-ribbed pulley that employs the metal bush of FIG. 5. FIG. 8 is a perspective view showing an example of a metal bush that can be used in the V-ribbed pulley according to the present invention.
FIG. 10 is a vertical sectional view and a front view, respectively. 2: V-ribbed groove (power transmission part) 4: V-ribbed pulley main body part (resin molding part) 6, 26, 34: Metal bush 14: Annular convex part, 16: Gear tooth (projection) 18: Annular groove, 20: Through holes 30,32,40: Knurl, 38: Protrusion

Claims (1)

[Scope of utility model registration request] 1. A metal bush including an annular resin molding portion integrally provided with a power transmission portion on an outer peripheral portion, and a metal bush integrally fixed to an inner peripheral portion of the resin molding portion. An annular convex portion embedded in the resin molded portion is provided at an intermediate position in the axial direction of an outer peripheral surface portion of the bush made of resin and is covered with the resin molded portion. On the outer peripheral surface of the power transmission resin rotating body having a structure in which a plurality of predetermined protrusions are provided at predetermined intervals in the circumferential direction, the convex portion is provided with respect to the annular convex portion of the metal bush. At least one of an annular groove opening on at least one of the side surfaces of the portion and a plurality of through-holes penetrating the side portion of the convex portion in the axial direction and located at predetermined intervals in the circumferential direction. One of them is formed, and a protrusion protruding from the outer peripheral surface of the annular convex portion is formed. , A rotating body made of resin for power transmission, which is configured to have a fan-shaped cross-sectional shape whose circumferential dimension increases toward the tip side.