JP2001234992A - Weight roller for belt transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a resin weight roller into a compact size and out of mixing of a lubricant. SOLUTION: This weight roller 21 used for a drive pulley for a belt transmission is provided by injection molding a material formed by mixing metal powder with resin having self-lubrication. The weight roller 21 has a columnar shape, has its outer circumferential face 22 set to a rolling face, and is provided with gate marks 24 and a through hole 25 in its end face 23. The external dimension and the weight of the weight roller 21 can be formed into similar to the conventional one by the metal powder, and the weight of the weight roller 21 is adjusted by the specific gravity and the mixing rate of the metal powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel structure of a weight roller used for a drive pulley of a belt transmission.

[0002]

2. Description of the Related Art As a weight roller for moving a movable face constituting a drive pulley of a belt transmission in the direction of a drive axis, a self-lubricating resin is integrally laminated on a surface of a metal ring (hereinafter, referred to as a "weight roller"). Is known as a laminated weight roller (for example, JP-A-3-61748). Japanese Patent Publication No. 8-16506 discloses that a weight roller itself is made of a fiber reinforced resin mixed with a lubricant (hereinafter, this is referred to as a fiber reinforced resin weight roller).

[0003]

However, the above-mentioned laminated weight roller uses a metal ring as the weight adjusting means, so that the metal ring must be machined in order to achieve high weight accuracy. Moreover, in order to laminate the resin on the surface of the metal ring, complicated insert molding is required. As a result, the number of manufacturing steps is increased as a whole, and the cost is increased.

On the other hand, if a fiber reinforced resin weight roller is used, the metal ring can be omitted, so that the production becomes easy and the cost can be reduced. However, in order to obtain a predetermined weight only with a resin material having a small specific gravity, the weight roller itself must be considerably large, and as a result, the belt transmission becomes large, and compactness is required. It was difficult to adopt it for belt transmissions for applications.

SUMMARY OF THE INVENTION An object of the present invention is to provide a weight controller which can be easily manufactured and made compact, and has a required self-lubricating property sufficient for greaseless.

[0006]

In order to solve the above-mentioned problems, a weight roller for a belt transmission according to the present invention is a weight roller provided for moving a movable face constituting a driving pulley of the belt transmission in a driving shaft direction. In addition, a resin having self-lubricating properties and a metal powder are mixed and molded.

[0007]

According to the present invention, a weight roller can be obtained by mixing a metal powder into a resin having a self-lubricating property and molding. At this time, by adjusting the specific gravity and the filling amount of the metal powder, a weight roller having a predetermined weight with high weight accuracy can be obtained. In addition, since machining after molding can be omitted, the device can be made small, easy to manufacture, and reduced in cost. In addition, since the self-lubricating resin and the metal powder are mixed, the required self-lubricating property sufficient for greaseless can be obtained, and the mixing of the lubricant as in the conventional example can be unnecessary.

Further, when the weight roller is formed in a columnar shape, the surface pressure at the contact portion with the movable face can be further reduced to reduce wear. Moreover, by providing a through-hole or the like on the shaft center side and removing the thickness, it becomes easy to adjust the weight or change the diameter of the hole to improve the discriminability. Further, by making the density or specific gravity of the metal powder different between the outer peripheral side and the inner peripheral side of the molded body, the rolling characteristics can be arbitrarily set with respect to the rotation of the engine.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to the drawings. FIG. 1 is a perspective view of a weight roller according to the present embodiment, FIG. 2 is a view showing an entire belt transmission using the weight roller, and FIG. 3 is a sectional view of a drive pulley portion thereof.

First, in FIG. 2, this belt transmission 1
Is a belt transmission used for a swing type power unit of a small motorcycle, and is disposed long in the front-rear direction in a transmission case 2 constituting the power unit.

The belt transmission 1 includes a driving pulley 3 disposed in the front and a driven pulley 5 disposed in the rear connected via a V-belt 4, and the driving pulley 3 and the driven pulley 5 are fixed faces, respectively. 6 and 7 and movable faces 8 and 9.

The drive pulley 3 has a fixed face 6 rotatably connected to a shaft end of a crankshaft 10 (drive shaft) of an engine (not shown) and a movable face 8 to be movable on the crankshaft 10 in the axial direction. Idler supported. The movable face 8 contains a weight roller described later inside.

The driven pulley 5 has a fixed face 7 connected to a driven shaft 11 so as to be rotatable integrally therewith, and a movable face 9.
Are freely rotatably supported on the driven shaft 11 so as to be movable in the axial direction, and are urged by a set spring 12 which is a compression coil spring so as to be constantly pressed against the fixed face 7 side. The driven shaft 11 rotates the rear axle via a reduction gear (not shown).

In the belt transmission 1, when the rotation of the crankshaft 10 increases, the winding radius of the V-belt 4 increases on the drive pulley 3 side due to the action of a weight roller described later on the drive pulley 3 side. On the other hand, when the rotation decreases, the drive pulley 3 side decreases and the driven pulley 5 side increases, so that the speed reduction ratio is continuously changed and the automatic transmission is changed.

FIG. 3 shows the details of the drive pulley 3, and as can be seen in FIG.
A boss 15 fixed to a screw portion 13 formed at the shaft end of the crankshaft 10 with a nut 14 and formed integrally with the center of the fixed face 6 in the direction of the rotation axis is fitted to the outer periphery of the crankshaft 10 and its tip Abuts on a lamp plate 16 fixed on the crankshaft 10.

The movable face 8 is supported on a boss 15 via a bearing 17 so as to be freely rotatable and movable in the axial direction. The outer peripheral portion of the lamp plate 16 also has a guide slope 19 inclined in the opposite direction, and the movable face 8 and the lamp plate 1
6, a roller chamber 20 is formed.

A plurality of roller chambers 20 are provided radially in the radial direction of the crankshaft 10, and the cross-sectional shape of each roller chamber 20 is defined by guide slopes 18 and 19, as shown in FIG. It is provided in a substantially V-shaped cross section whose width gradually decreases toward the side, and a weight roller 21 is accommodated therein.

The weight roller 21 is movable in the radial direction of rotation of the movable face 8, rotates together with the movable face 8, moves radially outward by centrifugal force when the rotation increases, and fixes the movable face 8. Face 6
Side, thereby changing the winding radius of the V-belt 4. When the weight roller 21 moves in the radial direction, it rotates in contact with the guide surfaces 18 and 19.

FIG. 1 shows the outer shape of a weight roller 21. The weight roller 21 has a columnar shape and is formed by injection molding a resin having a self-lubricating property mixed with metal powder. The size and weight are adjusted to a certain degree.

The outer peripheral surface 22 of the weight roller 21 forms a rolling surface when rotating while being in contact with the guide inclined surfaces 18 and 19, and is formed smoothly by the injection molding die surface. In addition, a gate mark 24 of injection molding is formed on the end face 23 in the central axis direction.
Are formed. Further, a through hole 25 is formed at the center. In addition, since uneven wear does not cause much problem on the end face 23, even if the gate mark 24 remains, machining such as polishing is not particularly necessary. In addition, since the gate mark 24 is not formed on the outer peripheral surface 22, the outer peripheral surface 2
2 is maintained.

The resin constituting the weight roller 21 can be any suitable general-purpose resin known to have good self-lubricating properties, such as polyamide 66, polyamide 46, polypropylene, and polyethylene terephthalate. Those having excellent moldability suitable for injection molding are suitable.

Further, as the metal powder, those made of various ferrous metals and non-ferrous metals such as tungsten can be appropriately selected and used. Of these, generally, if an iron-based material is used, the cost can be reduced, and if stainless steel is particularly used, rust prevention is improved. If tungsten is used, its specific gravity is large, so that the amount used can be reduced.

Further, if necessary, a lubricant is mixed. The lubricant is used to increase the self-lubricating property of the resin molded product. Graphite, molybdenum and the like are known, but the lubricant is not limited to these and can be appropriately selected from various known materials.

Using these materials, a weight roller 2
In order to mold 1, the resin, metal powder and, if necessary, powdery lubricant are weighed so that the product weight after molding becomes a predetermined amount,
Mix these. The mixing ratio at this time is arbitrary,
For example, resin: metal powder is set to about 6: 4.

If the mixture is kneaded and injection-molded, the weight roller 21 can be manufactured with high efficiency. In addition, since the outer peripheral portion 22 is pressed against the molding surface of the mold by a high injection pressure, the outer peripheral portion 22 is densely and smoothly molded, and can be used as it is without any mechanical processing such as polishing. As the molding method, not only injection molding but also various known methods such as compression molding and casting can be adopted. Further, it can be extruded into a round bar shape and cut into a predetermined size.

Next, the operation of this embodiment will be described. The weight roller 21 is entirely made of self-lubricating resin, and since the metal material mixed to obtain a predetermined weight is metal powder, the required self-lubricating property sufficient for greaseless can be obtained. It is not necessary to mix the lubricant as in the example.

When the belt transmission 1 is constructed by using the weight roller 21, as shown in FIG. 3, as the rotation of the movable face 8 increases, the weight roller 21 moves outward in the rotational radius direction by centrifugal force, and To the fixed face 6 side. At this time, the weight roller 21 can rotate with good self-lubricating properties while smoothly contacting the guide slope 18 of the movable face 8 and the guide slope 19 of the lamp plate 11, thereby preventing uneven wear of the weight roller 21. Moreover, it is not necessary to fill the roller chamber 20 with grease.

Further, since the metal powder is mixed, the outer dimensions and weight of the weight roller 21 itself can be made the same as those of the conventional laminated weight roller, and can be much more compact than the fiber reinforced resin weight roller. Therefore,
For a drive pulley 3 designed to use a conventional laminated weight roller, a new roller chamber 20 can be used as it is without using a new design change of the roller chamber 20, and a fiber reinforced resin weight roller can be used. The belt transmission 1 can be made more compact as compared with the case of FIG. Therefore, the present invention is suitable for a device requiring compactness, such as a belt transmission for a motorcycle.

In addition, the weight of the weight roller 21 can be adjusted by selecting the specific gravity of the metal powder and adjusting the mixing ratio, and by changing the mixing ratio of the resin and the metal powder between the surface portion and the interior portion. Can be formed in a multi-layered structure using a highly lubricating resin of metal powder as compared to the interior part, whereby the rolling characteristics can be set arbitrarily with respect to the rotation of the engine. Further, the density or specific gravity of the metal powder on the outer peripheral side and the inner peripheral side of the molded body can be made different. In addition, injection molding makes molding relatively easy, and no subsequent machining is required, making production easier.
Significant cost reduction becomes possible.

Further, for example, even in the case where the extrusion molding is employed, post-processing of a cut of a predetermined size is sufficient, and since this mechanical processing is basically processing for resin, it is easier than metal. In addition, since the uneven wear of the cut surface is not a problem unlike the outer peripheral surface 22, the cut surface can be left uncut.

In addition, when the weight roller 21 is formed in a cylindrical shape, the surface pressure at the contact portion of the movable face 8 with the guide inclined surface 18 can be further reduced, and the wear can be reduced. In addition, it is easy to adjust the weight by providing the through-holes 25 and the like on the axial center side and reducing the thickness, and it is expected that the discriminating property can be improved by changing the hole diameter.

The present invention is not limited to the above-described embodiment, but can be appropriately modified and applied within the principle of the present invention. For example, the weight can be adjusted by changing the size and number of the through holes 25. Also, the present invention can be applied to a belt transmission of a vehicle other than a motorcycle or a general machine. Further, since the resin is molded, coloring is easy, and the coloring can improve the discriminability in applications such as a model. This coloring can also be formed only on the surface layer side.

[Brief description of the drawings]

FIG. 1 is a perspective view of a weight roller according to the present embodiment.

FIG. 2 is a diagram showing an entire belt transmission using the weight roller.

FIG. 3 is a sectional view of the drive pulley part.

[Explanation of symbols]

1: belt transmission, 3: drive pulley, 4: V belt,
5: driven pulley, 6: fixed face, 8: movable face, 10: crankshaft, 16: lamp plate, 18:
Guide slope, 19: guide slope, 21: weight roller, 22: outer peripheral surface

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J050 AA02 BA03 BB08 CA02 CA09 CC02 3J103 AA02 AA12 AA41 BA46 CA52 EA02 FA14 FA15 FA19 FA25 GA02 GA52 HA03 HA11 HA15 HA32 HA33 HA35 HA42 HA46 HA60

Claims (3)

[Claims] 1. A weight roller provided for moving a movable face constituting a drive pulley of a belt transmission in a drive axis direction, wherein a resin having self-lubricating properties and a metal powder are mixed and molded. Weight roller for belt transmission. 2. The weight roller for a belt transmission according to claim 1, wherein the formed body has a cylindrical shape. 3. The weight roller for a belt transmission according to claim 1, wherein the density or the specific gravity of the metal powder on the outer peripheral side and the inner peripheral side of the molded body are different.