JP2002070966A - Belt type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering down of transmitting torque, which is generated by providing a part of non-conformity between a sheave angle and a flank angle of a V-belt in the conventional flange fixing its sheave angle, relating to a trouble generating deflection in the flange of a pulley due to a load of the V-belt. SOLUTION: A sheave angle formed by sheave surfaces 11a, 2a of a flange 1, 2 formed with a V-groove 5 is set to an angle α1 equal to a flank angle βof a V-belt B in a small diametric side, and set to an angle α2 smaller than the flank angle β in a large diametric side, so as to make the V-belt B and the sheave surfaces 1a, 2a come into proper contact in both the small/large diametric sides even by generating deflection between both the flanges 1, 2, improvement of transmitting torque is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt-type continuously variable transmission used for, for example, a power transmission of an automobile.

[0002]

2. Description of the Related Art In general, a belt-type continuously variable transmission has an input side and an output side provided with an input shaft and an output shaft arranged in parallel, a fixed flange fixed in an axial direction and a movable flange reciprocated in an axial direction. And a variable width V-groove between both flanges on each pulley,
The pulleys on the input and output sides are connected by a V-belt. At this time, both flanges of each pulley
A sheave surface that contacts the side surface of the belt is tapered, and a V-groove is formed between the sheave surfaces. And
The belt-type continuously variable transmission transmits the rotation of the input-side rotary shaft to the output-side rotary shaft via both the pulleys and the V-belt, and at this time, the widths of the V-grooves of both the pulleys change in inverse proportion. By reciprocating the movable flange, the winding position of the V-belt is slid in the radial direction of the pulley between the input side and the output side to change the speed ratio steplessly.

In the above belt-type continuously variable transmission, the V-belt is located on the large-diameter side (outer-peripheral side) when a load is applied.
In the IGH state, the large-diameter portions of both flanges of the input pulley may bend in the direction of being separated from each other due to the load of the V-belt. In this case, the V-groove is expanded and the V-belt is biased toward the small diameter side, and the transmission torque is reduced.

In view of the above-mentioned problems, a conventional belt-type continuously variable transmission employs a pulley with each pulley.
In some cases, the angle formed by both side surfaces of the V-belt is set to be larger than the angle formed by the sheave surfaces of both flanges. In this belt type continuously variable transmission, when the V-belt slides to the large-diameter side and the two flanges are bent in a direction away from each other, the angle of the sheave surface of the flange is enlarged, and the angle of the side surface of the V-belt is increased. In this state, the V-belt is brought into correct contact with the sheave surface to obtain good transmission torque. Such a belt-type continuously variable transmission is described in, for example, JP-A-7-83315.

[0005]

However, in the conventional belt type continuously variable transmission as described above, the angle formed by both side surfaces of the V-belt is set to be larger than the angle formed by the sheave surfaces of both flanges. Indeed, when loading, V
In the pulley where the belt is located on the large diameter side, it can cope with the bending of both flanges. Conversely, in the pulley where the V-belt is located on the small diameter side (center side) at the time of load, that is, in the LOW state, On the input pulley, in the HIGH state, on the output pulley, the V-belt is biased toward the large diameter side due to the mismatch between the angle of the side surface of the V-belt and the angle of the sheave surface of the flange, and as a result, the transmission torque is reduced. There was a point, and it was an issue to solve such problems.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a belt-type continuously variable transmission in which input and output pulleys having variable width V-grooves are connected by V-belts. In this case, even if both flanges are bent in the pulley where the V-belt is located on the large-diameter side at the time of load, the V-belt and the sheave surface of both flanges can be correctly contacted, and the V-belt has a small diameter at the time of load. It is an object of the present invention to provide a belt-type continuously variable transmission in which a V-belt and a sheave surface of both flanges can be brought into correct contact with each other even on a pulley located on the side, and a good transmission torque can always be obtained. .

[0007]

SUMMARY OF THE INVENTION A belt-type continuously variable transmission according to the present invention has a variable width between a fixed flange that is immovable in the axial direction and a movable flange that reciprocates in the axial direction. In a belt-type continuously variable transmission in which each pulley on the input side and the output side forming a V-groove is provided and both pulleys are connected by a V-belt, a sheave angle (an axis of the pulley shaft) formed by a sheave surface of a flange forming a V-groove is provided. Is set to be the same as the flank angle formed by the side surface of the V-belt (the angle formed by the center line and the side surface of the element of the V-belt) on the small-diameter side.
The difference between the sheave angle and the flank angle on the large-diameter side is set at an angle smaller than the flank angle. And a configuration in which the sheave angle is changed stepwise from the small-diameter side to the large-diameter side.
Claim 4 is a configuration in which the change portion of the sheave angle is continuous in a curved line. Claim 5 is a configuration in which the sheave angle is continuously changed from the small diameter side to the large diameter side.
The above configuration is used as means for solving the conventional problem.

[0008]

In the belt-type continuously variable transmission according to the first aspect of the present invention, the rotation of the input pulley is transmitted to the output pulley via the V-belt. By reciprocating each of the movable flanges so as to change in inverse proportion, the winding position of the V-belt is slid in the radial direction of the pulley between the input side and the output side to change the speed ratio steplessly. .

Under such a load, in the belt type continuously variable transmission, in the pulley where the V-belt is located on the large-diameter side, the large-diameter-side portions of both flanges are separated from each other by the load of the V-belt. When bent, the sheave angle formed by the sheave surface of the flange forming the V-groove is preset to a smaller angle than the flank angle formed by the side surface of the V-belt on the large-diameter side. The sheave angle is enlarged so that the sheave angle becomes close to or the same as the flank angle, whereby the V-belt and the sheave surfaces of both flanges are correctly contacted on the large diameter side of the pulley.

In the belt-type continuously variable transmission, in the pulley in which the V-belt is located on the small-diameter side, the deflection on the small-diameter side of both flanges is equal to zero or zero as compared with the large-diameter side; On the other hand, the sheave angle formed by the sheave surface of the flange forming the V groove is set in advance to be the same as the flank angle formed by the side surface of the V belt on the small diameter side.
Even on the small diameter side of the pulley, the V-belt and the sheave surfaces of both flanges come into correct contact.

In the belt-type continuously variable transmission according to the second aspect of the present invention, the difference between the sheave angle and the flank angle on the large-diameter side is determined by separating the two flanges from each other when the V-belt is loaded on the large-diameter side. In the pulley in which the V-belt is located on the large-diameter side, when the large-diameter-side portions of both flanges are deflected in a direction away from each other due to the load of the V-belt, The sheave angle is enlarged along with the bending of the flange, and this sheave angle becomes equal to the flank angle, whereby the V-belt and the sheave surfaces of both flanges are correctly contacted on the large diameter side of the pulley.

In the belt-type continuously variable transmission according to the third aspect of the present invention, the bending of both flanges caused by the load of the V-belt increases from the small diameter side to the large diameter side. Since the sheave angle is changed so as to gradually decrease from the side to the large diameter side, even if both flanges bend in the direction away from each other, the entire sheave surface from the small diameter side to the large diameter side has a V-belt. Is obtained in a stepwise manner.

In the belt-type continuously variable transmission according to a fourth aspect of the present invention, in the flange in which the sheave angle is changed stepwise from the small-diameter side to the large-diameter side, a portion where the sheave angle changes is defined. Since the V-belt is continuous in a curved line, the sliding of the V-belt in contact with the sheave surface in the radial direction of the pulley becomes smoother.

In the belt-type continuously variable transmission according to the fifth aspect of the present invention, the bending of the two flanges caused by the load of the V-belt increases from the small diameter side to the large diameter side. Since the sheave angle is changed so as to continuously decrease from the side to the large diameter side, even if both flanges bend in the direction away from each other, the entire sheave surface from the small diameter side to the large diameter side has a V-belt. Is continuously obtained, and the sliding of the V-belt in contact with the sheave surface in the radial direction of the pulley becomes smoother.

[0015]

According to the belt type continuously variable transmission according to the first aspect of the present invention, the input side and the output side pulleys having variable width V-grooves are connected by V-belts. In this case, even if both flanges are bent in the pulley where the V-belt is located on the large-diameter side at the time of load, the V-belt and the sheave surface of both flanges can be correctly contacted, and the V-belt has a small diameter at the time of load. The V-belt and the sheave surfaces of both flanges can be brought into correct contact with each other even on the pulley located on the side, and thus the contact between the V-belt and the sheave surfaces of both flanges can be made on both the large diameter side and the small diameter side. , The transmission torque can always be obtained, and the transmission torque can be improved as compared with a conventional continuously variable transmission having a pulley having a constant sheave angle. It can be. Further, as described above, it is possible to cope with bending of both flanges of the pulley,
This is extremely effective for application to a pulley whose flange is easily bent, that is, a pulley in which the flange is subjected to lightening or the like for the purpose of weight reduction.

According to the belt-type continuously variable transmission according to the second aspect of the present invention, the same effect as that of the first aspect can be obtained. In particular, the pulley in which the V-belt is located on the large diameter side under load is provided. In this case, even if the two flanges are bent, the sheave angle and the flank angle can be surely matched, and the contact state between the V-belt and the sheave surfaces of the two flanges can be made more accurate.

According to the belt-type continuously variable transmission according to the third aspect of the present invention, the same effects as those of the first and second aspects can be obtained. In particular, the entire sheave surface from the small diameter side to the large diameter side can be obtained. A correct contact state with the V-belt can be obtained in a stepwise manner, which can contribute to further improvement of the transmission torque.

According to the belt-type continuously variable transmission according to a fourth aspect of the present invention, the same effect as that of the third aspect can be obtained, and the portion where the sheave angle changes is made continuous by a curve. The V-belt can be smoothly slid in the pulley radial direction, and the smoothness of the speed change operation can be further improved.

According to the belt-type continuously variable transmission according to the fifth aspect of the present invention, the same effects as those of the first and second aspects can be obtained. In particular, the entire sheave surface from the small diameter side to the large diameter side can be obtained. A correct contact state with the V-belt can be continuously obtained, which can contribute to further improvement of the transmission torque, and also allows the V-belt to slide smoothly in the radial direction of the pulley, thereby improving the smoothness of the shifting operation. Can be further increased.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a belt-type continuously variable transmission according to the present invention will be described below with reference to the drawings.

A belt-type continuously variable transmission schematically shown in FIG. 1A has an input-side rotating shaft S1 connected to the engine side of an automobile.
And an output-side rotating shaft S2 connected to the axle side in parallel, fixed flanges 1, 3 which are immovable in the axial direction by integral molding with each of the rotating shafts S1, S2, and movable which can reciprocate in the axial direction. It has pulleys P1 and P2 on the input side and output side composed of flanges 2 and 4, and both pulleys P1 and P2
P2 is connected by a power transmission V-belt B.

Each of the pulleys P1, P2 has a fixed flange 1,
3 and sheave surfaces 1a to 4 of movable flanges 2 and 4 facing each other
a has a tapered shape, and forms V-grooves 5 and 6 of variable width whose intervals gradually increase outward between the sheave surfaces 1a to 4a. In addition, both pulleys P1 and P2 are
6 so that the width of each movable flange 2 changes inversely proportionally.
4 is driven to move the V-belt B to the sheave surfaces 1a,
In order to slide in the same direction along 3a, the arrangement of the fixed flanges 1, 3 and the movable flanges 2, 4 on the input side and the output side is opposite to each other. The V belt B is
As shown in FIGS. 1 (b) and 1 (c), this is a well-known type in which a large number of elements E are provided along with two endless rings C, C made of metal.

Here, in the belt-type continuously variable transmission, the pulley whose V-belt B is located on the large-diameter side (outer-peripheral side) at the time of load, that is, the output pulleys P2 and HI in the LOW state.
In the state of GH, at the input side pulley P1, FIG.
As indicated by the imaginary line in the upper half of the figure, the large-diameter portions of the opposed flanges 1 and 2 are bent in a direction away from each other due to the load of the V-belt B. When such bending occurs, the V-groove 5 is pushed and spread, and the V-belt B is biased toward the small diameter side (center side), so that the transmission torque is reduced. Although the amount of deflection Q of each of the flanges 1 and 2 shown in FIG. 1B may be slightly different due to a difference in the structure or the like, it is described as being the same for convenience.
The actual amount of deflection Q is about 50 μm.

In response to the above-described bending of the flanges 1 and 2, the belt-type continuously variable transmission has a small diameter side of both flanges 1 and 2 as shown in the lower half of FIG. d1
And the large-diameter side d2, the sheave angles α1, α2 formed by the sheave surfaces 1a, 2a and the perpendicular to the axis of the pulley P1 are different.

That is, the sheave angles α1 and α2 are set based on the flank angle β formed by the center line and the side surface of the element E of the V-belt B shown in FIG. The sheave angle α1 is set equal to the flank angle β (α1 = β), and the sheave angle α2 on the large diameter side is set smaller than the flank angle β (α2 <β).
At this time, the difference θ between the sheave angle α1 on the small-diameter side d1 and the sheave angle α2 on the large-diameter side d2 is equal to the difference between the flanges 1 and 2 described above.
Are angles corresponding to the respective deflection amounts Q. In other words, based on the sheave angle α1 of the small diameter side d1, the sheave angle α2 of the large diameter side d2 is set so that the interval between the outer peripheral ends of the flanges 1 and 2 is reduced by the amount of bending Q. It is.

As described above, each sheave angle α1, α
When 2 is set, the small-diameter side d which is the portion where the sheave angle changes
1 and the large-diameter side d2 can be configured to be continuous with a curve R. In this case, the sliding of the V-belt B in the pulley radial direction becomes even smoother.

[0027] The belt-type continuously variable transmission having the above-described structure includes:
The rotation of the input-side rotary shaft S1 is transmitted to the output-side rotary shaft S2 via the pulleys P1, P2 and the V-belt B. At this time, the widths of the V-grooves 5, 6 of the pulleys P1, P2 are inversely proportional. By reciprocating each of the movable flanges 2 and 4 so as to change, the winding position of the V-belt B is slid in the radial direction of the pulley between the input side and the output side, and the speed ratio is steplessly changed. .

Under such a load, if the belt-type continuously variable transmission is in a LOW state, the V-belt B is located on the small-diameter side d1 of the input-side pulley P1, and the V-belt B is located on the small-diameter side d1. The deflection is equal to zero as compared with the large diameter side d2, whereas the sheave angle α1 formed by the sheave surfaces 1a, 2a of the flanges 1, 2 forming the V groove 5 is determined by the flank formed by each side surface of the V belt B. Since the angle β is set to be the same, the sheave surfaces 1a, 2 of the V belt B and the flanges 1, 2
a comes into contact correctly, and the V-belt B is never biased toward the large-diameter side d2.

On the other hand, in the output side pulley P2, the large diameter side d2
The large-diameter portions of the flanges 3 and 4 are bent in a direction away from each other due to the load of the V-belt B, while the flanges 3 and 4 forming the V-groove 6 are formed.
The sheave angle α2 formed by the sheave surfaces 3a and 4a is set to an angle smaller than the flank angle β formed by each side surface of the V-belt B, so that the sheave angle α2 increases with the bending of the flanges 3 and 4. Then, the sheave angle α2 becomes substantially the same angle as the flank angle β, so that the V-belt B and the sheave surfaces 3a, 4a of both flanges 3, 4 come into correct contact.

When the speed is changed from the LOW state to the HIGH state, the V-belt B
Slides from the small-diameter side d1 to the large-diameter side d2, and at the same time, in the output-side pulley P2, the V-belt B slides from the large-diameter side d2 to the small-diameter side d1.
2, the sheave angles α1 and α2 are set in the same manner, so that the V-belt B and the sheave surfaces 1a to 4a of the flanges 1 to 4 are correctly contacted on the input side and the output side.

As described above, the belt-type continuously variable transmission is
Since the contact between the V-belt B and the sheave surfaces 1a to 4a can be correctly maintained on both the small diameter side d1 and the large diameter side d2, a good transmission torque can always be obtained.

FIGS. 2 and 3 are views for explaining another embodiment of the belt-type continuously variable transmission according to the present invention.

FIG. 2 shows a flange 1 constituting each pulley.
In the sheave surface 1a of (2-4), the sheave angles α3 to α5 are set so as to gradually decrease from the small diameter side to the large diameter side (α3>α4> α5). These sheave angles α3 to α5 are set based on the flank angle β of the V-belt (see FIG. 1) as in the previous embodiment. As a specific example, the correction amount on the small diameter side is set to 0, The correction amount at the outer peripheral end of the intermediate portion is 10 μm, and the correction amount at the outer peripheral end of the large diameter portion is 50 μm. In this case, in order to further enhance the smoothness of the slide of the V-belt B, it is more desirable to adopt a configuration in which the portion where the sheave angle changes is continuous with the curve R.

FIG. 3 shows a flange 1 constituting each pulley.
In the sheave surface 1a of (2-4), the sheave angle on the small diameter side
Sheave in the range from degree α1 to sheave angle α2 on the large diameter side
Set so that the angle becomes smaller continuously (α1> α2)
It is a thing. These sheave angles α1 and α2 are
As in the embodiment, the flank angle β of the V-belt (see FIG. 1)
)), And as a specific example, the smaller diameter side
The amount of correction in the middle part is 0, the amount of correction in the middle part is 10 μm, and the large diameter part
Is 50 μm at the outer peripheral edge of. like this
The curved sheave surface 1a has a predetermined curvature R (y²+ X
²= R) or y = x² Formed by a curve based on a function such as
can do.

In the belt type continuously variable transmission of each of the above embodiments,
Finer and more accurate correction of the deflection generated on the flange of the pulley under load becomes possible. That is, the bending of both flanges is continuous from the small diameter side to the large diameter side, and increases from the small diameter side to the large diameter side. Thus, as in the above embodiments, the sheave angles α1 to α5 are changed stepwise or continuously from the small diameter side to the large diameter side of the flange 1 so as to be gradually or continuously reduced, so that the sheave surface 1a as a whole has a V-belt. Will be obtained.

The shape of the sheave surface can be selected from straight lines, curved lines, or a combination of straight lines and curved lines according to the degree of bending of the flange and the like, and is not limited to the above embodiments. In the belt-type continuously variable transmission according to the present invention, for example, due to the material and structure of the flange, when one flange is easily bent and the other flange hardly bends, only the sheave surface of the one easily bent flange is provided. It is also possible to adopt a configuration in which a predetermined sheave angle is set.

[Brief description of the drawings]

FIG. 1 is a view for explaining an embodiment of a belt-type continuously variable transmission according to the present invention, and is a cross-sectional view schematically showing the continuously variable transmission, in which a flange is bent to an upper half. FIG. 4B is a cross-sectional view of the pulley showing a state where each sheave angle is set in the lower half, and FIG.

FIG. 2 is a sectional view of a main part of a flange showing a case where a sheave angle is changed stepwise as another embodiment of the belt-type continuously variable transmission according to the present invention.

FIG. 3 is a sectional view of a main part of a flange showing a case where a sheave angle is continuously changed as another embodiment of the belt-type continuously variable transmission according to the present invention.

[Explanation of symbols]

 B V belt P1 Input side pulley P2 Output side pulley 13 Fixed flange 1a 3a Sheave surface 24 Movable flange 2a 4a Sheave surface 5 6V groove α1-α5 Sheave angle β Frank angle

Claims (5)

[Claims] An input-side pulley and an output-side pulley forming a variable width V-groove between a fixed flange that is immovable in the axial direction and a movable flange that reciprocates in the axial direction. In a belt-type continuously variable transmission connected by a belt, the sheave angle formed by the sheave surface of the flange forming the V-groove is set to be the same as the flank angle formed by the side surface of the V-belt on the small diameter side. Wherein the belt-type continuously variable transmission is set at an angle smaller than the flank angle. 2. The difference between the sheave angle and the flank angle on the large-diameter side is an angle corresponding to the amount by which the two flanges bend in directions separating from each other when the V-belt is loaded on the large-diameter side. The belt-type continuously variable transmission according to claim 1, wherein: 3. The sheave angle is changed stepwise from a small diameter side to a large diameter side.
2. The belt-type continuously variable transmission according to 1. 4. The belt-type continuously variable transmission according to claim 3, wherein the portion where the sheave angle changes is continuous with a curve. 5. The sheave angle is continuously changed from a small diameter side to a large diameter side.
2. The belt-type continuously variable transmission according to 1.