JP2992700B2 - Resin pulley - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin pulley in which an outer cylindrical portion and an inner cylindrical portion are connected by a disk having radial ribs.

<Prior Art> FIG. 8 shows a conventional resin pulley attached to an auto-tensioner for an auxiliary drive V-ribbed belt for an automobile engine. This resin pulley 50
Has an outer cylindrical portion 2 and an inner cylindrical portion 3. The inner and outer cylindrical portions 2, 3 are connected by a disk portion 4, and the disk portion 4 is provided with a large number of radial ribs 5 for reinforcement.

The resin pulley 50 is manufactured by so-called resin integral molding in which a molding die is press-filled with a molten resin.

<Problems to be Solved by the Invention> The conventional resin pulley 50 has a problem that vibration and abnormal noise are generated. This is because, in the case of integral molding with a resin, the amount of sink marks tends to differ depending on the resin filling location. In particular, in the resin pulley 50, there is a considerable difference in the amount of resin filling in the radial direction between the location where the radial rib 5 is provided and the location where the radial rib 5 is not provided. For this reason, the sink amount at a position where the radial rib 5 is present becomes larger than the sink amount at a position where the radial rib 5 is not present, and minute irregularities (not shown) are formed on the outer peripheral portion 2 a of the outer diameter cylindrical portion 2. I will. As for this unevenness, the formation phase in the circumferential direction is aligned in the axial direction, that is, since the unevenness is formed by waving at the same phase in the circumferential direction,
The state of contact between the belt and the suspended belt becomes unstable, causing vibration and causing abnormal noise.

Therefore, by removing the irregularities, the outer diameter cylindrical portion 2
If the roundness is increased, vibration and abnormal noise can be prevented, but this is difficult in manufacturing.

The present invention has been made in view of such circumstances, and a resin material that does not generate vibration or abnormal noise by positively utilizing unevenness on the surface that is inevitably generated during integral molding. It is intended to provide pulleys.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides an outer diameter cylindrical portion, an inner diameter cylindrical portion, and a disk portion connecting the inner and outer cylindrical portions,
A resin pulley having a number of radial ribs provided on a disk portion, wherein the outer diameter cylindrical portion has a plurality of minute wavy bands on its outer peripheral surface, and the minute wavy bands are Each was formed over the entire circumference of the outer diameter cylindrical portion, and provided in parallel in the axial direction with each other, and the top portions were continuous in the circumferential direction. Thus, a resin pulley was formed from the above.

In the present invention, the apex refers to a portion at or above the central diameter between the maximum diameter and the minimum diameter of the minute wavy band. Further, that the tops are continuous in the circumferential direction means that each top is continuous in the circumferential direction when viewed from the side.

<Operation> According to the above configuration, the top of the minute wavy band provided on the outer peripheral surface of the outer diameter cylindrical portion becomes a contact point at the time of meshing with the belt, but since the top is continuous in the circumferential direction, the resin The degree of contact of the belt with the pulley made of resin is made constant, and the engagement between the pulley made of resin and the belt is stabilized.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

The basic structure of the resin pulley 1 is the same as that of the conventional example. That is, the resin pulley 1 has an outer cylindrical portion 2 and an inner cylindrical portion 3, and the inner and outer cylindrical portions 2 and 3 are connected by the disk portion 4. The disk portion 4 is provided with a plurality of radial ribs 5 for reinforcement on the front and rear surfaces in the axial direction at regular intervals. These components are formed by resin integral molding.

The feature of the present invention is that the outer peripheral surface 2a of the outer cylindrical portion 2 is formed.
This is the structure above. That is, on the outer peripheral surface 2a of the outer cylindrical portion 2 of the resin pulley 1, two minute wavy bands A and B are formed in parallel in the axial direction as shown in FIG. 1 (c).
The minute wavy strips A and B have a width obtained by dividing the resin pulley 1 into two in the axial direction, and are formed continuously in the circumferential direction. Further, the minute wavy strips A and B are formed at the same pitch as each other, but the phases thereof are formed exactly opposite to each other. That is, when one wavy band A (B) is located at the top 10 (the formation position of the top 10 is shown by hatching in FIG. 1B), the other wavy band B (A) is It is located on the bottom 11. The minute wavy bands A and B are formed over the entire outer peripheral surface 2 a of the outer cylindrical portion 2. The tops 10 of the minute wavy strips A and B formed in this way are continuous in the circumferential direction.

When this resin pulley 1 is used for an auto tensioner,
Since the minute wavy bands A and B are continuously provided on the outer peripheral surface 2a of the outer diameter cylindrical portion 2, the contact of the belt (not shown) to be bridged becomes constant, and the resin pulley 1 and the belt And the meshing with is stabilized. Therefore, vibration does not occur between the belt and the resin pulley 1, and noise does not occur.

Next, the production of the resin pulley 1 will be described with reference to FIG.

The resin pulley 1 can be manufactured using a molding die 11 shown in FIGS. 2 (a) and 2 (b). That is, a mold 11 having an inner surface shape 12 corresponding to the minute wavy band portions A and B is created by correcting sink marks during molding, and the resin pulley 1 is manufactured using the mold 11. According to this manufacturing method, it is possible to manufacture the resin pulley 1 having the minute wavy belt portions A and B shown in FIGS. 1 (a), (b) and (c). Further, the present invention is not limited to the method shown in FIG. 1, and it is possible to manufacture any shape of minute wavy band. In addition, according to this manufacturing method, the outer shape of the outer cylindrical portion 2 is corrected. It is also conceivable to manufacture resin pulleys with high roundness.

Further, the resin pulley 1 can be manufactured by the manufacturing method shown in FIG. That is, as described in the conventional example, when a resin pulley having the radial ribs 5 is manufactured by integral molding, irregularities are necessarily formed on the outer peripheral surface 2a of the outer diameter cylindrical portion 2. Therefore, in this method, the minute wavy band portions A and B are formed using the formed unevenness. This will be described below.

In the integral molding, a large amount of sink is formed in a portion of the outer diameter cylindrical portion 2 where the radial rib 5 is formed, and the surface 2a is depressed to form irregularities on the surface. Therefore, the mold is formed so that the formation positions of the radial ribs 5 are alternately arranged before and after in the axial direction with the disk portion 4 interposed therebetween. Then, as shown in the figure, a gate hole g serving as a resin injection port is provided at a position facing the radial rib 5 on one side, and the resin is injected therefrom to form the resin pulley 1.

When the resin pulley 1 is formed in this manner, two minute wavy strips A and B are formed in parallel in the axial direction. The small wavy strips A and B formed have a bottom 11 on the radial rib 5 and a radial rib adjacent in the circumferential direction, because the amount of sink in the radial rib 5 forming place is larger than in other places. The middle position between 5, 5 is the top 10. In addition, the radial rib 5
Are formed alternately before and after in the axial direction, so that the minute wavy strips A and B are formed at the same pitch and with phases opposite to each other. That is, FIGS. 1 (a), (b), (c)
The resin pulley 1 having the surface shape shown in FIG. However, in this case, the pitch of the concavo-convex formed is the radial rib 5.
Are coarser than those shown in FIG. 1 (c).

Although the minute wavy bands A and B in the above-described embodiment have a width obtained by bisecting the resin pulley 1 in the axial direction, a minute wavy band having a width divided more finely in the axial direction may be used. Resin pulleys 20 and 30 shown in FIGS. 4 and 5, respectively.
Has a small wavy strip C, D, having a width divided into three in the axial direction.
E, F, G, H are formed.

The phases of the minute wavy strips C, D, and E of the resin pulley 20 shown in FIG. 4 are different from each other, but the adjacent fine wavy strip tops 10 are in contact with each other and regularly form their positions in the circumferential direction. It is meandering, and the top 10 is generally continuous in the circumferential direction.

Also, each of the minute wavy bands F, G,
H is irregularly formed, but overall each apex 10 is circumferentially continuous.

These resin pulleys 20 and 30 are shown in FIGS. 2 (a) and 2 (b).
Can be manufactured by using a modified mold 11 shown in FIG.

In addition, as shown in FIG.
An embodiment is also conceivable in which a plurality of J, K, and L are formed to make the top 10 continuous in the circumferential direction. This will be described below.

In the conventional example, the phase in the circumferential direction of the unevenness formed on the outer peripheral surface of the resin pulley is the same in the axial direction of the pulley. The meshing of the gears fluctuated, causing vibration and abnormal noise. On the other hand, the outer cylindrical portion 2
If a plurality of wavy bands I, J, K, L are arranged along the axial direction on the outer peripheral surface 2a of the As shown in the figure, the probability that the top 10 of any one of the wavy bands I, J, K, and L exists in each region that continues along the outer peripheral surface 2a increases. Furthermore, by increasing the number of wavy strips I, J, K, L, this probability can be made as close to 100% as possible. Therefore, in the present embodiment, by forming a plurality of completely irregular wavy bands I, J, K, and L, the top 10 can be regarded as being substantially continuous in the circumferential direction.

In manufacturing such a resin pulley 40, the second
This can be dealt with by improving the shape of the mold 11 shown in the figure.
Furthermore, as shown in FIG. 7, it can also be manufactured by changing the position of the gate hole g which is the resin injection point.

In general, the gate hole g, which is a resin injection point, is provided at a position (for example, a center position between the radial ribs 5 adjacent in the circumferential direction) at which the resin wraps around in the mold and, as a result, the resin mixes uniformly. I have. Therefore, in the present embodiment, the position of the gate hole g is set at one radial rib 5 as shown in FIG. Then, the wraparound and mixing of the resin become uneven, the surface shape of the outer diameter cylindrical portion 2 is disturbed, and quite irregular minute wavy bands I, J, K, L are formed. Although not shown, the similar minute wavy band portions I, J, K, and L can be formed by providing the positions of the gate holes g at irregular positions.

<Effects of the Invention> As described above, according to the present invention, since the top of the minute wavy band provided on the outer peripheral surface of the outer diameter cylindrical portion is continuously provided on the outer peripheral surface of the outer diameter cylindrical portion, the resin The degree of contact of the belt with the pulley is stabilized, the meshing between the resin pulley and the belt is stabilized, and inconveniences such as vibrations and abnormal noise during operation of the resin pulley are eliminated.

[Brief description of the drawings]

1 (a), (b), (c), FIG. 2 (a),
FIG. 3 (b) and FIG. 3 relate to an embodiment of the present invention. FIG. 1 (a) is a partially cutaway perspective view showing its external shape, FIG. 1 (b) is a developed view thereof, and FIG. c) is II in FIG. 1 (b).
FIG. 2 is a sectional view taken along line II. FIG. 2 (a) is a cross-sectional view of a mold provided for the first manufacturing method, and FIG. 2 (b) is a III-I thereof.
FIG. 2 is a sectional view taken along line II. FIG. 3 is a development view of a resin pulley manufactured by the second manufacturing method. FIG. 4 and FIG. 5 are development views showing other embodiments. FIG. 6 is a development view showing still another embodiment, and FIG. 7 is a development view of a resin pulley showing a manufacturing process of the embodiment of FIG. FIG. 8 is a partially cutaway perspective view showing the appearance of a conventional example. 2 ... outer diameter cylindrical part 3 ... inner diameter cylindrical part 4 ... disk part 5 ... radial ribs A to L ... minute wavy band 10 ... top of minute wavy band

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 55/48 F16H 55/38

Claims (1)

(57) [Claims] 1. A resin pulley having an outer diameter cylindrical portion, an inner diameter cylindrical portion, a disk portion connecting the inner and outer cylindrical portions, and a number of radial ribs provided on the disk portion, The outer diameter cylindrical portion has a plurality of minute wavy bands on the outer peripheral surface thereof, and the minute wavy bands are respectively formed over the entire circumference of the outer diameter cylindrical portion, and are provided in parallel with each other in the axial direction. A resin pulley, the top of which is continuous in the circumferential direction.