JPH06272737A - V-belt for continuously variable transmission - Google Patents

Abstract

PURPOSE:To enlarge a pulley ratio width and decrease any shift of the core, without changing circumferential length of v-belt, inter-shaft distance and sheave angle at all. CONSTITUTION:Tip edge part of an element is formed, as tapered off to a main face 3, by a tapered face 5 of taper angle theta and a convex circular arc face 6 which makes contact with both these tapered face 5 and the main face 3 and continues smoothly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-belt for a continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, as a V belt for a continuously variable transmission,
For example, the one described in JP-A-55-100443 is known.

In the above-mentioned conventional publication, as shown in FIGS. 10 to 12, one endless ring 01 and a large number of endless rings 01 movably attached to each other have their main surfaces 02a in contact with each other. A V-belt composed of the element 02 is shown, and the tip end of the element is tapered by the tapered surface 02b so that the V-belt can be bent at the pulley winding portion.

[0004]

However, in the above-mentioned conventional V belt for continuously variable transmission, the element 02 is used.
The front side of the main surface 02a, the tapered surface 02b, and the boundary line 02
Since the element 02 has a shape having c, the boundary line 02c between the main surface 02a and the tapered surface 02b is set to a fixed rotation pitch radius R, and the element 02 is used because power is always transmitted by the rotation pitch radius R. When the circumference of the V-belt, the distance between the axes, and the sheave angle are determined, the pulley ratio width and the misalignment characteristics are geometrically determined, and it is difficult to change or improve them.

The present invention has been made in view of the above problems, and an object thereof is to provide a V belt for a continuously variable transmission which is wound around a pulley to transmit power. The objective is to increase the pulley ratio width and reduce misalignment without changing the circumference, shaft distance, and sheave angle.

[0006]

In order to achieve the above object, in the V-belt for a continuously variable transmission of the present invention, the tip of the element has a tapered shape having a convex arc surface smoothly continuous from the main surface.

That is, a V-belt for a continuously variable transmission which is wound around a pulley to transmit power, is attached to one or a plurality of endless rings and is movably attached to the endless rings, and has main surfaces mutually connected. In a V-belt for a continuously variable transmission, the V-belt for a continuously variable transmission is composed of a large number of elements that are in contact with each other. It is characterized in that it has a tapered shape having a convex arc surface smoothly continuing from the main surface.

[0008]

When the V-belt for the continuously variable transmission is wound around the two sets of pulleys and the power is transmitted, the elements contact each other on the main surfaces to transmit the power at the straight portions and the elements are relatively opposed at the pulley winding portions. The elements are in contact with each other on the main surface and the convex arc surface, and the diameter of this contact portion serves as a rotation pitch radius that determines the pulley ratio, and transmits power.

Specifically, when the pulley diameter becomes large, the relative inclination between the elements becomes small, so that the contact portion of the adjacent element moves to the pulley outer diameter side of the convex arc surface,
The rotation pitch radius determined by the contact part becomes large, but when the pulley diameter becomes small, the relative inclination of the elements becomes large, so the contact part of the adjacent element moves to the pulley inner diameter side of the convex arc surface, and the contact part The rotation pitch radius that determines the pulley ratio changes according to the pulley diameter such that the rotation pitch radius that is determined by

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

First, the structure will be described.

1 to 3 are views showing a V-belt for a continuously variable transmission according to an embodiment of the present invention.

A V-belt for a continuously variable transmission according to an embodiment is shown in FIGS.
As shown in FIG. 3, a large number of elements 1, endless rings 2
It consists of and.

The elements 1 are formed so as to make frictional contact with the inner peripheral surface of the endless ring 2, and are arranged in the longitudinal direction of the endless ring 2 without any gap while keeping the main surfaces 3 in contact with each other. It is mounted so that it can be moved to.

The endless ring 2 is formed by stacking a plurality of endless ring elements 2a in layers.

The tip of the element is formed to be tapered with respect to the main surface 3, and is formed so as to be in contact with both the taper surface 5 having a taper angle θ and the taper surface 5 and the main surface 3 and to be smoothly continuous. It is composed of a convex arc surface 6. The boundary line between the main surface 3 and the tapered surface 5 is located at the rotation pitch radius R of the conventional element.

Reference numeral 7 denotes a protrusion formed on the main surface 3 on the belt traveling direction side, which engages with a recess (not shown) in the adjacent element 1.

Next, the operation will be described.

[Power Transmission Function] When the V belt for a continuously variable transmission is wound around two sets of pulleys to transmit power, the elements 1 contact each other on the main surface 3 in the straight line portion to transmit power, and Since the element 1 is relatively inclined at the winding portion, the element 1 contacts each other on the main surface 3 and the convex arc surface 6, and the diameter of this contact portion serves as a rotation pitch radius that determines the pulley ratio, and power introduce.

When the pulley ratio changes, the relative inclination between the elements 1 of the pulley winding part also changes,
The contact portion between the main surface 3 and the convex arc surface 6 also changes according to the pulley ratio.

[Pulley Ratio Width Increasing Action] The change in the contact portion will be described in detail. As the pulley diameter becomes larger, the relative inclination between the elements 1 becomes smaller. Therefore, as shown in FIG. As the convex arc surface 6 moves to the outer diameter side of the pulley, the rotation pitch radius RL becomes larger than the conventional rotation pitch radius R. When the pulley diameter becomes small, the element 1
Since the relative inclination between them becomes large, as shown in FIG.
The contact portion moves to the inner diameter side of the pulley of the convex arc surface 6, and the rotation pitch radius RS becomes smaller than the conventional rotation pitch radius R.

As described above, the radius of rotation pitch is equal to that of the element 1.
Since it changes depending on the relative inclination between the pulleys, the low pulley ratio can be further reduced, the high pulley ratio can be further increased, and the pulley ratio width can be increased, as compared with the conventional example.

Incidentally, the result of the experiment conducted by the present inventor is shown in FIG.

* Experimental specifications Belt circumference: 600 mm Axial distance: 150 mm Element thickness: 2.2 mm Convex arc surface radius: 71.5 mm Taper angle: 4.8 ° * Experimental results As shown in FIG. When both the secondary pulley strokes are 0 to 16 mm, the pulley ratio is 2.
It increased from 5 to about 2.9. That is, the pulley specific width is improved by about 30% as compared with the conventional example.

[Misalignment reduction action] Under the same conditions as above, when the pulley ratio width is set to a predetermined width, the secondary pulley stroke required to secure this pulley ratio width is the same as that of the conventional example. Compared with less. Therefore, the misalignment of the pulley can be reduced over the entire area.

Incidentally, the result of the experiment conducted by the present inventor is shown in FIG.

* Experimental specifications Belt circumference: 600 mm Inter-axis distance: 150 mm Element thickness: 2.2 mm Convex arc surface radius: 71.5 mm Taper angle: 4.8 ° Pulley ratio width: 0.4-2 .5 * Experimental results As shown in FIG. 7, the pulley misalignment was smaller over the entire pulley ratio range in the example than in the conventional example.

Particularly, when the primary pulley and the secondary pulley are both stroked, the misalignment is reduced by about 0.15 mm in the vicinity of the pulley ratio of 1.0 where the misalignment is maximized.

As described above, in the continuously variable transmission V-belt of the embodiment, the element tip portion is tapered at the continuously variable transmission V-belt wound around the pulley to transmit power. Since the taper surface 5 having the angle θ and the convex arc surface 6 that is in contact with both the taper surface 5 and the main surface 3 and is smoothly continuous are formed to be tapered with respect to the main surface 3, the circumference of the V-belt, the axis It is possible to increase the pulley ratio width and reduce the misalignment without changing the distance between the sheave and the sheave angle.

Although the embodiments have been described above with reference to the drawings, the specific structure is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

For example, in the embodiment, the convex arc surface 6 is formed on the front side of the element 1, but as shown in FIG. 8, both the main surface 13 and the tapered surface 15 are formed on the back side of the element 11. It is also possible to form a convex arcuate surface 16 in contact with the main surface 2 on both sides of the element 21 as shown in FIG.
It is also possible to form a convex arc surface 26 that is in contact with both 3 and the tapered surface 25. Here, 17 and 27 are protrusions that engage with the recesses (not shown) of the adjacent elements 11 and 21.

Further, in the embodiment, the element tip portion shape is shown to have the tapered surface 5, but the element tip portion shape may be formed only by the main surface and the convex arc surface smoothly continuous from the main surface.

[0033]

As described above, according to the present invention, in the V-belt for a continuously variable transmission which is wound around a pulley to transmit power, the element tip portion is smoothly continuous from the main surface. Since it has a tapered shape with a convex arc surface,
It is possible to obtain the effect that the pulley specific width can be increased and the misalignment can be reduced without changing the circumferential length of the V-belt, the axial distance, and the sheave angle.

[Brief description of drawings]

FIG. 1 is a front view showing a V-belt for a continuously variable transmission according to a first embodiment.

FIG. 2 is a side view showing a V-belt for a continuously variable transmission according to the first embodiment.

FIG. 3 is an enlarged view of portion A of FIG. 2 showing the shape of the tip of the element.

FIG. 4 is a diagram showing a rotation pitch radius of the V belt for a continuously variable transmission according to the first embodiment when the pulley has a large diameter.

FIG. 5 is a diagram showing a rotation pitch radius of the continuously variable transmission V-belt according to the first embodiment when the pulley has a small diameter.

FIG. 6 is a pulley ratio characteristic comparison diagram with respect to a secondary pulley stroke in the first embodiment and the conventional V belt for continuously variable transmission.

FIG. 7 is a comparison diagram of misalignment characteristics with respect to the pulley ratio in the first embodiment and the conventional V belt for continuously variable transmission.

FIG. 8 is a side view showing elements of a V belt for a continuously variable transmission according to a second embodiment.

FIG. 9 is a side view showing elements of a V-belt for a continuously variable transmission according to a third embodiment.

FIG. 10 is a front view showing a conventional V-belt for a continuously variable transmission.

FIG. 11 is a side view showing a conventional V-belt for a continuously variable transmission.

FIG. 12 is an enlarged view of part A ′ of FIG. 11 showing the shape of the tip of the conventional element.

[Explanation of symbols]

 1,11,21 Element 2 Endless ring 3,13,23 Main surface 5,15,25 Tapered surface 6,16,26 Convex arc surface 7,17,27 Projection

Claims (1)

[Claims] 1. A V-belt for a continuously variable transmission wound around a pulley to transmit power, the V-belt being one or more endless rings and movably attached to the endless rings.
A V-belt for a continuously variable transmission, comprising a number of elements whose main surfaces are in contact with each other, and the tip end of the element is tapered so that the V-belt can be bent at a pulley winding portion. A V-belt for a continuously variable transmission, characterized in that the portion has a tapered shape having a convex arc surface smoothly continuous from the main surface.