JPH11315898A - Weight roller for v-belt type automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the temperature in kneading of a whisker with a solid lubricating material and in molding by forming a synthetic resin part for covering the circumferential part of a cylindrical metallic roller body by mixing the whisker and the solid lubricating material to an aliphatic polyamide resin. SOLUTION: A weight roller consists of a cylindrical metallic roller body and a rigid resin part 22 covering the circumferential part thereof. The synthetic resin part 22 is formed by mixing a reinforcing whisker 24 and a solid lubricating material 25 to an aliphatic polyamide resin 23. The whisker 24 is finely and homogeneously dispersed in the whole area of the aliphatic polyamide resin 23 by kneading together with the solid lubricating material 25. The temperature can be reduced in kneading of the solid lubricating material 25 to semi- aromatic polyamide resin and in molding. The whisker 24 keeps the needle form, whereby the solid lubricating material 25 can be prevented from falling from the aliphatic polyamide resin 23. Thus, the surface treatment agent of the whisker or the solid lubricating material can be prevented from deterioration or being decomposed by heat, and the load can be minimized in the kneading of the whisker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight roller for a V-belt type automatic transmission used for a scooter type motorcycle, a snowmobile and the like.

[0002]

2. Description of the Related Art Conventionally, in a V-belt type automatic transmission used for a scooter type motorcycle, a V-belt is wound around a driving pulley on an engine side and a driven pulley on a rear wheel side, and the two pulleys are driven in accordance with the rotation speed. The speed is changed by changing the winding diameter of the V-belt steplessly. The two pulleys form a belt groove by a fixed pulley plate fixed to a rotating shaft and a movable pulley plate configured to be able to move forward and backward with respect to the fixed pulley plate.

In the drive pulley, a weight roller is interposed between a back surface of a movable pulley plate and a cam plate fixed to the rotating shaft so as to face the back surface, and the weight roller is driven by centrifugal force. By moving inward or outward in the radial direction, the movable pulley plate advances and retreats with respect to the fixed pulley plate, so that the winding diameter of the V-belt changes.

The weight roller is formed in a cylindrical shape from a roller body made of a metal cylinder and a synthetic resin portion covering the outer peripheral portion of the roller body. The back surface of the movable pulley plate and the cam surface of the cam plate with which the weight roller contacts are flat surfaces, and locally high stress is generated in the synthetic resin portion during operation. While reinforcing by mixing reinforcing fibers such as
E) and the like, and a self-lubricating property is provided by mixing a solid lubricant.

[0005] However, even if the reinforcing fibers are mixed in such a manner, partial deformation, breakage or wear cannot be prevented. This is considered to be because, although stress occurs in a minute area on the surface of the weight roller, the reinforcing fiber cannot uniformly reinforce the entire area of the area as shown in FIG. .

FIG. 6 is an enlarged sectional view showing a synthetic resin portion of a conventional weight roller. FIG. 6 shows a state in which the weight roller is in contact with a movable pulley plate or a cam plate. In FIG. 6, reference symbol A indicates a contacted member such as a movable pulley plate or a cam plate,
B indicates a synthetic resin portion of the weight roller. Also, the code C
Is a reinforcing fiber mixed in the synthetic resin part, and D is a solid lubricant. As shown in the figure, when the reinforcing fiber C is used, a portion that is not reinforced by the reinforcing fiber C occurs in a range where the synthetic resin portion B contacts the contacted member A. This non-reinforced part is indicated by the symbol S. Since the wear proceeds in the non-reinforced portion S, the above-described problem occurs.

In order to solve such a problem, the applicant has proposed a weight roller in which reinforcement is carried out by whiskers as disclosed in Japanese Patent Application Laid-Open No. Hei. This weight roller employs a semi-aromatic polyamide resin as a synthetic resin forming a synthetic resin portion, and mixes a whisker (needle-shaped crystal) as a reinforcing material into the semi-aromatic polyamide resin and a solid lubricant. I have.

Since whiskers can be densely and homogeneously filled in the synthetic resin portion as compared with the reinforcing fibers, the use of whiskers instead of reinforcing fibers has an effect on local stress. Can be reinforced. Moreover, since the whiskers are dispersed to the surface of the synthetic resin portion, the wear resistance is significantly improved.

[0009]

However, when the synthetic resin portion of the weight roller is formed of a semi-aromatic polyamide resin as described above, the whisker or the solid lubricant is formed on the whisker or the solid lubricant according to the properties of the semi-aromatic polyamide resin as described below. May have a negative effect. That is, since the semi-aromatic polyamide resin has high heat resistance, the temperature at the time of kneading and molding the whisker or solid lubricant must be relatively high, and the adhesiveness with the synthetic resin material provided on the whisker is improved. In some cases, the surface treatment agent for enhancing the solid lubricant or the solid lubricant may be deteriorated or decomposed by heat.

Further, since the semi-aromatic polyamide resin has a benzene ring in the main chain, the viscosity at the time of melting hardly decreases, and when kneading whiskers and a solid lubricant, so-called kneading is carried out strongly. The pressure during molding must be set high. As a result, the whisker is easily broken, and the degree of reinforcement is reduced even if the whisker is mixed.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a synthetic resin material which does not cause deterioration or decomposition of a whisker surface treatment agent or a solid lubricant and which is hard to break whiskers. V with synthetic resin part formed
An object of the present invention is to provide a weight roller for a belt-type automatic transmission.

[0012]

SUMMARY OF THE INVENTION In order to solve this object, a weight roller for a V-belt type automatic transmission according to the present invention comprises a cylindrical metal roller body and a synthetic resin covering an outer peripheral portion of the roller body. The synthetic resin portion is formed by mixing a whisker and a solid lubricant into an aliphatic polyamide resin.

According to the present invention, since the melting temperature of the aliphatic polyamide resin is lower than that of the semi-aromatic polyamide resin, the whisker and the solid lubricant are compared with the case where the synthetic resin portion of the weight roller is formed of the semi-aromatic polyamide resin. Can be lowered during kneading and during molding. Moreover, since the aliphatic polyamide resin does not have a benzene ring in the main chain, the viscosity at the time of melting is lower than that of the semi-aromatic polyamide resin, and the load applied to the whisker when kneading the whisker is small.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a weight roller for a V-belt type automatic transmission according to the present invention will be described below in detail with reference to FIGS. FIG. 1 is a plan view showing a drive pulley portion of a V-belt type automatic transmission employing a weight roller according to the present invention, FIG. 2 is a cross-sectional view showing an enlarged drive pulley portion, and FIG. 3 is a rear view of a movable pulley plate. , FIG.
FIG. 5 is a cross-sectional view of the weight roller, and FIG.

In these figures, reference numeral 1 denotes a V-belt type automatic transmission according to this embodiment. This V-belt type automatic transmission 1 is mounted on a unit type power unit 2 of a scooter type motorcycle and transfers power of an engine 3 to a rear wheel 4.
To communicate. In FIG. 1, reference numeral 5 denotes a cylinder of the engine 3, 6 denotes a piston, 7 denotes a crankshaft, and 8 denotes a unit case of the power unit 2. The crankshaft 7 constitutes a rotating shaft according to the present invention. The unit case 8 includes the V-belt type automatic transmission 1 and the V-belt type automatic transmission 1.
The centrifugal clutch (not shown) and the reduction mechanism (not shown) interposed between the belt-type automatic transmission 1 and the rear wheel 4 are held in a state of covering them.

The V-belt type automatic transmission 1 comprises a drive pulley 11 supported on the crankshaft 7 and a drive pulley 1
1 is provided with a driven pulley (not shown) connected via a V-belt 12. A driven shaft (not shown) that rotates together with the driven pulley is connected to the axle of the rear wheel 4 via the centrifugal clutch and the speed reduction mechanism.

As shown in FIG. 2, the drive pulley 11 has a fixed pulley plate 13 fixed to the shaft end of the crankshaft 7 and a belt groove together with the fixed pulley plate 13 facing the fixed pulley plate 13. The movable pulley plate 14 to be formed and the movable pulley plate 14
And a weight roller 16 interposed between the cam plate 15 and the movable pulley plate 14.

The movable pulley plate 14 is supported by the crankshaft 7 so as to be movable in the axial direction, and the cam plate 15 is fixed to the crankshaft 7. The fixed pulley plate 13 and the movable pulley plate 15 are formed in an umbrella shape from an aluminum alloy, and the cam plate 15 is formed in an umbrella shape from a steel material. FIG. 2 illustrates a state where the movable pulley plate 14 is farthest from the fixed pulley plate 13 above the crankshaft 7, and a state where the movable pulley plate 14 is closest to the fixed pulley plate 13 below the crankshaft 7. It is drawn in.

As shown in FIGS. 2 and 3, a plurality of guides 17 extending in the axial direction of the crankshaft 7 are formed on the rear surface of the movable pulley plate 14 facing the cam plate 15 at intervals in the circumferential direction. A structure is adopted in which the slider 18 on the cam plate 15 side is slidably fitted to rotate integrally with the cam plate 15. On the surfaces of the movable pulley plate 14 and the cam plate 15 that face each other, cam surfaces 14a and 15a that gradually approach toward the outside in the radial direction are formed. The weight roller 16 is sandwiched between the movable pulley plate 14 and the cam plate 15 in a state where the outer peripheral surface is in contact with the cam surfaces 14a and 15a. As shown in FIG. 3, guide walls 18 and 1 are provided on the rear surface of the movable pulley plate 14.
The guide walls 18 and 19 restrict the movement of the weight roller 16 in the axial direction (the radial direction of the movable pulley plate 14).

As shown in FIG. 4, the weight roller 16 is composed of a cylindrical metal roller body 21 and a synthetic resin portion 22 that covers the outer periphery of the roller body 21. The roller body 21 is formed of brass, iron, or the like. As shown in FIG. 5, the synthetic resin portion 22 includes a whisker 24 for reinforcement and a solid lubricant 2 on an aliphatic polyamide resin 23.
5 is mixed. Since the whisker 24 has a smaller outer shape than conventional reinforcing fibers,
By being kneaded together with the solid lubricant 25, it is dispersed so as to be dense and homogeneous throughout the aliphatic polyamide resin 23.

As the aliphatic polyamide resin 23, PA4
6 or PA66, and the whisker 24 in this embodiment uses aluminum borate whose surface is covered with a surface treatment agent. The surface treatment agent is for firmly bonding the whisker 24 to the aliphatic polyamide resin 23. The solid lubricant 25 uses polytetrafluoroethylene resin (PTFE). The whisker and the solid lubricant are not limited to those described above. For example, silicon carbide, silicon nitride, potassium titanate, alumina, etc. can be used as the whisker. , Molybdenum disulfide,
Solid wax such as graphite and olefin resin, olefin resin and the like can be employed.

Since the aliphatic polyamide resin 23 has a lower melting temperature than the semi-aromatic polyamide resin forming the synthetic resin portion of the conventional weight roller, it is compared with the case where the synthetic resin portion 22 is formed of the semi-aromatic polyamide resin. Thus, the temperature at the time of kneading the whisker 24 and the solid lubricant 25 and at the time of molding can be lowered. Further, since the aliphatic polyamide resin 23 has no benzene ring in the main chain and has a lower viscosity at the time of melting than the semi-aromatic polyamide resin, the load applied to the whisker 24 when kneading the whisker 24 is small. , The whiskers 24 maintain a needle-like form.

Since the solid lubricant 25 can be prevented from falling off from the aliphatic polyamide resin 23 by maintaining the needle-like shape of the whiskers 24, the degree of reinforcement by the whiskers 24 can be increased. In addition to
The lubricity by the solid lubricant 25 is improved, and the wear resistance is further enhanced. Since the solid lubricant 25 has low adhesion to the aliphatic polyamide resin 23, if the abrasion progresses and the solid lubricant 25 is not in a state of being engaged with the aliphatic polyamide resin 23, in other words, if the so-called anchor effect is lost, the aliphatic polyamide resin It drops off from 23. However, when the aliphatic polyamide resin 23 is used, the whisker 24 keeps the needle shape during kneading and molding as described above, so that the whisker 24 sticks into the solid lubricant 25 as shown in FIG. , It is difficult for the solid lubricant 25 to fall off.

Since the weight roller 16 used in the V-belt type automatic transmission 1 for a motorcycle locally generates stress while being exposed to a high temperature, the synthetic resin material forming the synthetic resin portion 22 of the weight roller 16 is It must have both heat resistance and toughness. In general, it is known that the toughness of synthetic resin decreases as the heat resistance increases. However, the aliphatic polyamide resin 23 has a property of absorbing moisture, and the toughness is improved by absorbing moisture. For this reason, by using this aliphatic polyamide resin 23 for the weight roller 16 of the V-belt type automatic transmission 1 for a motorcycle, the weight roller 16 is made of a synthetic resin material having the same heat resistance as the aliphatic polyamide resin 23. It is possible to manufacture the weight roller 16 having high heat resistance and high toughness as compared with the case of forming. In addition, the aliphatic polyamide resin 23
Expands when it absorbs moisture, but the whiskers 24 are mixed into the aliphatic polyamide resin 23 so as to be dense and homogeneous, and the expansion of the aliphatic polyamide resin 23 is suppressed. The weight roller 16 in which the occurrence of the wrinkles does not occur can be formed.

The whisker 24 has a smaller outer shape than the conventional reinforcing fiber, and easily falls off with the wear of the aliphatic polyamide resin 23. Therefore, the weight roller 16 using the whisker 24 is liable to generate abrasion powder. However, since the aliphatic polyamide resin 23 has hygroscopicity as described above, the aliphatic polyamide resin in the wear powder absorbs moisture, so that the weight increases and the sediment easily occurs. Therefore, it is possible to prevent the V-belt from slipping due to the abrasion powder adhering to the V-belt 12.

Further, a solid lubricant 25 made of PTFE is used.
Generates a transfer film on the mating material (movable pulley plate 14 and cam plate 15) in the initial stage of sliding, so that the whisker 24 that has fallen off due to the wear of the aliphatic polyamide resin 23 is taken into the transfer film. Become like As a result, the transfer film is reinforced by the whiskers 24 and the wear resistance of the movable pulley plate 14 and the cam plate 15 is improved, and the whiskers 24 that are scattered are reduced. It becomes difficult.

[0027]

EXAMPLE In this embodiment, a synthetic resin portion 22 was formed by mixing aliphatic polyamide resin 23, whiskers 24 and solid lubricant 25 at a weight ratio of 6: 2: 2. By employing this mixing ratio, the weight roller 16 excellent in heat resistance and wear resistance could be formed.

[0028]

As described above, according to the present invention, since the melting temperature of the aliphatic polyamide resin is lower than that of the semi-aromatic polyamide resin, the whisker and the solid lubricant are compared with the case where the semi-aromatic polyamide resin is used. Can be lowered during kneading and during molding.

Therefore, the surface treatment agent of the whisker and the solid lubricant can be prevented from being deteriorated or decomposed by heat, and a high quality weight roller can be provided.

Further, since the aliphatic polyamide resin does not have a benzene ring in the main chain, the viscosity at the time of melting is lower than that of the semi-aromatic polyamide resin, and the load applied to the whisker when kneading the whisker is reduced. Therefore, the whiskers maintain a needle-like shape. Therefore, it is possible to provide a weight roller that is less likely to be deformed or damaged and has high wear resistance.

[Brief description of the drawings]

FIG. 1 is a plan view showing a drive pulley portion of a V-belt type automatic transmission employing a weight roller according to the present invention.

FIG. 2 is an enlarged sectional view showing a driving pulley portion.

FIG. 3 is a rear view of a movable pulley plate.

FIG. 4 is a sectional view of a weight roller.

FIG. 5 is an enlarged schematic view showing a main part.

FIG. 6 is an enlarged sectional view showing a synthetic resin portion of a conventional weight roller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... V belt type automatic transmission, 7 ... crankshaft, 11 ... drive pulley, 12 ... V belt, 13 ... fixed pulley plate, 14 ... movable pulley plate, 15 ... cam plate,
16: weight roller, 22: synthetic resin part, 23: aliphatic polyamide resin, 24: whisker, 25: solid lubricant.

Claims (1)

[Claims] 1. A movable pulley plate which is provided so as to be able to advance and retreat with respect to a fixed pulley plate fixed to a rotating shaft and forms a belt groove together with the fixed pulley plate, and a cam fixed to the rotating shaft on the back side of the movable pulley plate. The weight roller for the V-belt type automatic transmission interposed between the plate and the V-belt type automatic transmission is composed of a cylindrical metal roller main body and a synthetic resin portion covering the outer peripheral portion of the roller main body. A weight roller for a V-belt type automatic transmission, which is formed by mixing a reinforcing material made of whiskers and a solid lubricant into an aliphatic polyamide resin.