JPS61157863A - V-belt type automatic transmission - Google Patents

Abstract

PURPOSE:To diminish the ordinary or partial wear of a V-belt by making the outer periphery of a weight for the V-belt of resin which has the prescribed value of bending elastic modulus and is mixed with solid lubricant. CONSTITUTION:A V-belt type automatic transmission 10 is comprised of a crank side pulley 12 supported on a crankshaft 4, a rear wheel side pulley 14 supported on a rear wheel side pulley shaft 5 through a rotatable collar 13, and a V-belt 15 etc.. A weight 16 being circular in section makes contact with the back surface of a movable pulley plate 12b and a cam surface on the inner surface of its peripheral wall. A cam member is shaped into bevel form, and holds the weight 16 slidably in radial direction between the movable pulley plate 12b and itself. The inside of the weight 16 is made of metallic material such as iron etc., and its outer periphery is made of resin which has the bending elastic modulus of 3-13X10kg/cm, and is mixed with solid lubricant, or resin composite materials composed of nucleus resin filled with fiber.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a belt-type automatic transmission used in motorcycles, snowmobiles, etc.

[Conventional technology]

■In a belt type automatic transmission, a belt is passed between a driving pulley and a driven pulley, and each of the driving pulley and driven pulley is fixed to the rotating shaft. It has a pulley plate and a movable pulley plate which forms a belt groove opposite to the fixed pulley plate and is movable back and forth in the axial direction. Then, by pushing the movable pulley plate of the driving pulley by the centrifugal force of a weight that engages the back surface and peripheral wall of the movable pulley plate and rotates with the driving pulley, is configured to change continuously.

In particular, this belt-type automatic transmission has been widely used in scooters, family bikes, practical bikes, and snowmobiles in recent years because it provides a stepless and smooth gear ratio and has a simple structure. It is used.

By the way, in this type of belt-type automatic transmission, the weight is constantly sliding on the back of the movable pulley plate in response to fluctuations in the rotational speed of the rotating shaft, so the wear of these parts becomes a problem. . For this reason, conventionally,
As disclosed in Japanese Patent No. 52900, a grease reservoir is formed on the back side of the movable pulley plate, and a lubricant such as grease is used to suppress wear of the weight when sliding on the back side of the movable pulley plate. ing.

[Problems to be solved by invention C] However, in conventional belt-type automatic transmissions of this type, there is a problem in that even if the weights are lubricated with grease, the life of the weights cannot necessarily be extended. Ta. This is thought to be because when lubricated with grease, the viscosity of the grease is relatively high and the weight cannot be rotated. As a result, there is a problem in that the impact load due to vibrations and the like at the top is concentrated in one part, causing uneven wear on the weight and preventing smooth movement of the movable pulley plate.

[Means for solving problems]

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a V-belt type automatic transmission in which the life of the weight can be extended. The V-belt type automatic transmission according to the present invention has a bending elastic modulus of 3 to 13 x 10' kg /
cI11, preferably 4.5-9 x 10' kg/
cni, and is made of resin or resin-based composite material mixed with a solid lubricant.

[Effect]

In the present invention, the elastic force of the resin or resin-based composite material buffers the impact, reduces wear caused by the impact of the weight, and reduces uneven wear.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing the main parts of a V-belt automatic transmission according to the present invention, and FIG. 2 is a cross-sectional view showing a unit swing type engine such as a scooter equipped with a V-belt automatic transmission. In the figure, the reference numeral 1 indicates a unit swing type engine, and in order to function as a component of the suspension system that suspends the rear wheels 2, this engine 1 is mounted on a pivot at the rear of the vehicle body (not shown) so as to be able to swing vertically. supported.

The unit swing type engine 1 includes an engine body 3, a power transmission mechanism 6 that transmits the power of the engine body 3 to a rear wheel pulley shaft 5 via a crankshaft 4, and a power transmission mechanism 6 that decelerates the rotation of the rear wheel pulley shaft 5. A rear wheel shaft 8 connected to a reduction gear 7 is integrally held by a transmission case 9.

Reference numeral 10 denotes a V-belt type automatic transmission that constitutes the power transmission mechanism 6 together with a centrifugal clutch 11. a rear wheel pulley 14 supported on the rear wheel pulley shaft 5 via a collar 13;
A V-belt 15 or the like extends between these pulleys, and transmits the rotation of the crankshaft 4 to the rear wheel side pulley shaft 5 via the centrifugal clutch 11. This rear wheel side pulley shaft 5
The rotation is further reduced in speed by a reduction gear 7 and then transmitted to the rear wheel shaft 8.

The crank side pulley 12 and the rear wheel side pulley 14 are
Fixed pulley plates 12a and 14a are fixed to the crankshaft 4 and collar 13, respectively, and movable pulley plates 12b and 14b which form belt grooves opposite to the fixed pulley plates 12a and 14a and can move forward and backward in the axial direction. have.

The fixed pulley plate 12a and the movable pulley plate 12b of the crank-side pulley 12 are formed into an umbrella shape from, for example, aluminum, iron, or stainless steel. In the embodiment, one made of aluminum die-casting is used. The movable pulley plate 12b is integrally formed with a peripheral wall projecting rearward in the axial direction on the outer peripheral edge.

Reference numeral 16 denotes a weight having a circular cross section, and is engaged with a cam surface formed on the front surface of the movable pulley plate 12b and the inner surface of the peripheral wall. A cam member 17 is located behind the movable pulley plate 12b and is fixed to the crankshaft 4. The cam member 17 is formed into an umbrella shape from a pressed material such as a steel plate, and is connected to the movable pulley plate 12b. A weight 16 is held between them so as to be slidable and removable in the radial direction. In other words, the weight 16 is the movable pulley plate 1
It is stored in a weight storage space S formed between the movable pulley plate 12b and the cam member 17, and is engaged with both cam surfaces of the movable pulley plate 12b and the cam member 17. These cam surfaces extend in the radial direction, and the spacing between them is determined by the centrifugal force of the weight 16 accompanying the rotation of the crank-side pulley 12, which pushes the movable pulley plate 12b.
It is set to become gradually narrower toward the outer diameter direction so as to change the engagement radius with 5.

That is, the cam surface of the movable pulley plate 12b is formed to gradually bulge rearward, and the cam surface of the cam member 17 is formed so as to gradually bulge forward.

The weight 16 is provided with a cylindrical weight adjustment member 18 made of a metal material such as iron or brass inside, as shown in an enlarged vertical section in FIG.

Moreover, the weight is set to such a weight that a centrifugal force for pushing the movable pulley plate 2b is obtained when the crankshaft 4 reaches a predetermined rotational speed. Here, weight adjustment member 1
Since 8 has an inner hole, it is possible to circulate air and increase the contact area with the air, and furthermore, by changing the inner diameter, the weight can be adjusted to a desired value. Weight adjustment member 1
8 is fixed by using the weight adjusting member 18 when molding the weight 16.
This is done by inserting or press-fitting after molding.

The material forming at least the outer peripheral portion of the weight 16 has a bending elastic modulus of 3 to 13X10'kg/cJ.
, preferably 4.5 to 9 x 10' kg/cd, and a resin mixed with a solid lubricant or a fiber-reinforced resin as a resin composite material in which the resin is filled with fibers is used.

To be more specific, the resin in this case is nylon resin.

Polyacecool resin (POM), polytetrafluoroethylene resin (PTFE), polybutylene thirefthal resin (PBT), polypropylene resin (PP),
It is said to be polyethylene resin (PE), phenol resin, polyimide resin, etc. The fiber is glass fiber,
It is said to be carbon fiber or aramid fiber (for example, Kevlar fiber manufactured by DuPont). The solid lubricant is polytetrafluoroethylene resin (PTFE).

Examples include graphite and molybdenum disulfide (MoSz). However, the above-mentioned PTFE is not used when the base material is PTFE.

Specifically, the materials shown in the following table are used, for example.

The outer diameter of the cam member 17 is the movable pulley plate 12b.
The cam member 1 is formed smaller than the inner diameter of the peripheral wall of the cam member 1.
The weight storage space S is provided between the outer circumferential edge of the crank-side pulley 12 and the inner circumferential edge of the movable pulley plate 12b.
A gap g communicating with the outside is provided. This gap g
is set so that the cam member 17 and the movable pulley plate 12b are spaced apart from each other in the axial direction to a maximum at the top position shown by the chain line in FIG.

A guide member 19 is interposed between the movable pulley plate 12b and the cam member 17 and guides the cam member 17. Note that the movable pulley plate 12b and the cam member 17
Since the weight 16 has self-lubricating properties, the cam surface of
The surface finishing accuracy may be somewhat rough, and although it is not necessary, a plated finish such as hard plating may be used.

In the V-belt type automatic transmission configured in this way, since a solid lubricant is mixed into the weight 16, it has self-lubricating properties, and wear due to sliding with the cam surface is suppressed without supplying lubricant. can. Further, the weight 16 has a bending elastic modulus of at least 3 to 13 x 10' kg at the outer circumference.
/cn! Since it is made of this material, it can be elastically deformed when it is hit by the movable pulley plate 12b or the cam member 17 due to vibration or the like. Here, since the upper and lower limits of the bending elastic modulus are set, the weight 16 has a surface hardness that causes plastic deformation that impairs the smooth movement of the movable pulley plate 12b or wears out the mating material. It has been adjusted so that this does not occur.

Therefore, by absorbing and buffering the energy of the impact through the elastic deformation, the members are not hit against each other as in the conventional case, so that wear due to impacts such as vibrations can be reduced.

Furthermore, since the above-mentioned wear can proceed approximately uniformly over the entire outer circumferential surface, uneven wear can also be reduced.

This is thought to be because the weight 16 rotates, albeit slightly, due to the vibrations in the top part and the elastic force accompanying these vibrations. The amount of wear is determined by a bending modulus of elasticity of 4.5.
~9 XIO' kg/an (When a material is used, the buffering effect acts effectively, so it becomes the smallest.

As described above, the content of the present invention is to reduce abrasion and uneven wear due to the impact by buffering the impact of vibration with the elastic force of the weight 16, so the explanation is given in the above embodiment. The present invention is not limited to those in which a gap g is formed between the cam member 17 and the movable pulley plate 12b, but can also be implemented in a V-belt type automatic transmission equipped with a sealed pulley filled with grease. be able to.

According to experiments, the amount of wear was extremely small in the first to third examples shown in the table, and it was smaller in the fourth example. In addition, the flexural modulus of elasticity 2.0 XIO'k[/6 of cd filled with 10 wt% Teflon
Nylon undergoes plastic deformation and sag, resulting in 30wt
% carbon fiber filled flexural modulus 19.0 X10'
In the Bolifu Enylencer/L/7 fluid with a weight of kg/cIlt, the amount of wear on mating members such as the movable pulley plate 12b is large.

〔Effect of the invention〕

As explained above, according to the present invention, at least the outer peripheral portion of the weight that pushes the movable pulley plate is made of resin or resin-based composite material having a bending elastic modulus within a predetermined range and mixed with a solid lubricant. Because of the shape, the weight can absorb impact through its elastic force.

Therefore, the wear and uneven wear of the weight due to impact can be reduced, and the life of the weight can be extended.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main parts of a V-belt automatic transmission according to the present invention, FIG. 2 is a cross-sectional view showing a unit swing type engine such as a scooter equipped with the V-belt automatic transmission, and FIG. The figure is a vertical sectional view showing an enlarged weight. 4...Crankshaft, 10...V-belt type automatic transmission, 12...Crank side pulley, 12a...
Fixed pulley plate, 12b... Movable pulley plate, 15... V-belt, 16... Weight, 1
7...Cam member. 18... Weight adjustment member. Procedural amendment export) 1. Display of the case 1982 Patent Application No. 276807 2, Name of the invention ■ Belt type automatic transmission 3, Person making the amendment Relationship to the case Patent Applicant name (name) (AO7) Yamaha Motor Co., Ltd. 5. Target of correction (1) "Polybutylene terephthal resin" on page 8, lines 18 to 19 of the specification is corrected to "polybutylene terephthalate resin." (2) The table on page 9 of the same book is amended as follows. that's all

Claims (1)

[Claims] A pulley having a fixed pulley plate fixed to a rotating shaft, a movable pulley plate that forms a belt groove opposite to the fixed pulley plate and can move forward and backward in the axial direction, and a pulley that engages with the back surface and peripheral wall of the movable pulley plate. In a V-belt type automatic transmission equipped with a weight that pushes a movable pulley plate by centrifugal force generated by the rotation of the V-belt type automatic transmission, and a cam member that clamps the weight between the movable pulley plate and the Rate is 3~13×10^
A V-belt type automatic transmission comprising a weight of 4 kg/cm^2 and made of resin or resin-based composite material mixed with a solid lubricant.