JPS60109661A - Disc for belt-drive type continuously variable transmission - Google Patents

Abstract

PURPOSE:To aim at enhancing the efficiency of transmission and as well to prolong the lives of belts and discs, by forming a surface having a surface roughness of more than 20mu on the drive surface of a conical plate-like disc, and as well by setting the ratio of a flat surface area in the tip end of the surface convex section of the disc at a value from 20 to 70%. CONSTITUTION:The drive surface of a conical plate-like disc has a surface roughness of more than 20mu, and the ratio of a flat surface area in the tip end of the surface convex section of the disc is set at a value from 20 to 70%. With this arrangement the belt is prevented from slipping so that the efficiency of transmission may be enhanced and as well the seizing and abrasion thereof may be reduced, thereby the lives of belts and discs may be prolonged.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a disc for a heald-driven continuously variable transmission;
In detail, the belt-driven continuously variable transmission is designed to prevent slippage of the heald and improve transmission efficiency by providing unevenness on the drive surfaces of the opposing conical disks. It takes a long time to use the disc.

The conventional continuously variable transmission is capable of continuously controlling the gear ratio of the transmission, making full use of the characteristics of the engine and improving exhaust gas and fuel efficiency.

In general, continuously variable transmissions are classified into fluid type, mechanical type, and electric type, but for vehicles, most of them are fluid type and mechanical type, and among these, hydraulic drive, held drive, and fluid torque converters are the main ones.

The belt-driven continuously variable transmission is shown in Figures 1 and 2.
As shown in the figure, the opposing circles εIL plate-shaped disks 1 are suspended between the two sets of disks 1 in a heald shape, and are formed by stacking a plurality of endless metal bands in a hoop 2,
It has a hoop groove, is slidable in the width direction of the hoop 2 through the five-groove groove, and is composed of a large number of blocks 3 arranged in succession.

Random surface irregularities of 20 to 30 microns are formed on the contact surface 4 of the block 3 used in the belt with the disk 1 in order to adjust the coefficient of friction between the block 3 and the disk 1.

One of the two sets of disks 1 has a movable side and a fixed side, and the movable side is moved in the opposite direction with respect to the fixed side by a clutch (not shown) to change the gear ratio. be.

By the way, in a belt-type continuously variable transmission, the block 3 used as a heald is pressed against the disk l on the opposing conical plate and transmits torque. However, if the relative coefficient of friction between the block 3 and the disk 1 is low, the belt It has the disadvantage of causing slippage.

Belt slip not only reduces transmission efficiency but also has the disadvantage of causing damage to the belt and disk I, such as scuffing.

On the other hand, if the relative coefficient of friction between the block 3 and the disk 1 is too high, smooth gear changes may not be possible, resulting in the generation of vehicle vibrations or field noise.

Further, there is a drawback that the life of the belt and the disk 1 is shortened.

From the above, it is necessary to set the relative coefficient of friction between the block 3 and the disk I within an appropriate range, and as a countermeasure for this, conventionally, the block end face 3a is roughened by blasting the end face 3a. , attempts have been made to adjust the relative friction coefficients.

C. Purpose of the Invention The present invention prevents belt slippage, improves transmission efficiency, and extends the life of belts and disks by forming surface irregularities on opposing drive surfaces in the shape of conical plates. It is an object of the present invention to provide a disc for a heald-driven continuously variable transmission that can improve the dimensional accuracy and productivity of a belt-driven continuously variable transmission compared to a case where surface irregularities are formed on the end face of the block. The purpose is

2. Structure of the Invention According to the present invention, two sets of conical plate-shaped disks facing each other and a plurality of endless metal bands hung like a belt between the two sets of disks are provided. The hoops formed in a laminated manner have a T-shaped cross section, and a hoop groove for inserting the hoop is formed between the thin protrusion part and the thick protrusion part, and the hoop is inserted into the hoop groove. The thick-walled protruding portion is configured of a plurality of blocks that are continuously arranged so as to be slidably movable in the width direction of the hoop, and the tapered side surface that contacts the drive surface of the disk is arranged in a straight line. A disc for a belt-driven continuously variable transmission in a continuously variable transmission, in which surface irregularities of 20μ or more are formed on the aforementioned opposing conical plate-shaped disc drive surfaces, and a flat part area at the tip of the surface convexity is formed. This is achieved by a disc for a belt-driven continuously variable transmission characterized in that the ratio is 20 to 70%.

E, Example Hereinafter, the present invention will be described in detail based on the accompanying drawings.

In the description of the embodiments below, parts that are the same as or equivalent to those of the conventional example shown in FIGS.
Explanation will be omitted by assigning the same reference numerals as those in the figure and FIG. 2.

FIGS. 3 and 4 show an embodiment in which surface irregularities are formed on the drive surface of the disk 1 according to the present invention.

FIG. 3 shows a cross-sectional shape of the drive surface of the disk 1, and the drive surface of the disk 1 has surface irregularities of 20 μm or more.

In addition, when a high load is applied between the block 3 and the disk 1, as shown in Fig. 4, a flat part with an area ratio of 20 to 70% is formed at the tip of the surface convex part. ,
The durability of the block 3 and the disk 1 can be further improved.

FIG. 5 shows a photograph of the surface appearance of the drive surface of the disk in the case where a flat portion is formed at the tip of the surface convex portion.

In this photograph, the fair-skinned part is the flat part at the tip of the surface convex part, and the black part is the four parts (troughs) of the surface.

In this example, the flat portion area ratio is 35%.

The uneven surface shape shown in Figure 3 can be achieved by means such as shot blasting, liquid honing, and etching, and the flat portion at the tip of the surface convexity shown in Figure 4 can be achieved by light machining or breaking-in. It can be formed by et al.

As described above, disks with various flat area ratios at the tip of the convex portion of the drive surface were manufactured, each was incorporated into an automobile belt-driven continuously variable transmission, and an endurance test was conducted at a constant gear ratio. went.

For the evaluation, the disk 1 material was carburized and quenched to JIS standard SCM30 and then shot blasted, and the block 3 material was quenched and tempered to JIS standard SUJ 2 and the end surface polished.The test conditions were as follows. Input rotation speed: 3
500rpm, gear ratio: 2, output torque H15kg-m
, test time: 150 hours.

The test results are shown in FIG.

From this result, when the area ratio of the flat part at the tip of the surface convex part of the drive surface of the disk 1 is 20 to 70%, the block 3 has less wear and has excellent durability, but when it is less than 20%, the block end face 3a It has become clear that excessive wear occurs due to fatigue, and when it exceeds 70%, slip occurs between the disk 1 and the block 3, resulting in excessive wear due to seizure.

F. Effects of the Invention As is clear from the above, according to the disc for a heald drive type continuously variable transmission according to the present invention, by forming surface irregularities on the opposing conical drive surfaces, the belt In addition to preventing slippage, improving transmission efficiency, and extending the life of the belt and disk, it also improves the dimensional accuracy and productivity of belt-driven continuously variable transmissions compared to the case where surface irregularities are formed on the block end face. It has the advantage of being able to improve

[Brief explanation of drawings]

Figure 1 is a schematic perspective view of the main parts of a conventional belt-driven continuously variable transmission. Figure 2 is a perspective view showing how the hoop and block are assembled. Figure 3 is a disc with an uneven surface. FIG. 4 is a diagram showing the cross-sectional shape of the disk drive surface of the present invention. FIG. 5 is a schematic diagram showing the surface state of the disk drive surface of the present invention. FIG. 6 is a graph showing changes in the wear amount of the block depending on the area ratio of the flat part at the tip of the convex part of the driving surface of the disc. Block 3a -------Block end applicant Toyota Motor Cup type cold gear 1, 2, and 2 drawings: (no change in content) March) 2nd, 2nd, Title of the invention: Disk 3 for Held Drive Continuously Variable Transmission, Relationship with the case of the person making the amendment Patent Applicant Address: 1 Toyota-cho, Toyota City, Aichi Prefecture Address: 1971, Toyota City, Aichi Prefecture
February 28, 2015 5. Subject of amendment (1) Full text of specification (2) Drawing 6. Contents of amendment

Claims (1)

[Scope of Claims] (1) Two sets of opposing conical plate-shaped discs, and a hoop formed by stacking a plurality of endless metal bands suspended like a belt between the two sets of discs; , has a T-shaped cross section, and a hoop groove into which the hoop is inserted is formed between the thin protrusion and the thick protrusion.By inserting the hoop into the hoop groove, the hoop can slide in the width direction of the hoop. The belt drive in a continuously variable transmission is movable, and the thick-walled protrusion has a tapered side surface that contacts the drive surface of the disk, and is composed of a plurality of continuously arranged blocks. A disc for a continuously variable transmission, in which surface irregularities of 20μ or more are formed on the above-mentioned opposing conical plate-shaped disc drive surfaces, and the area ratio of the flat part at the tip of the surface convexity is 20 to 70%. A disc for a heald-driven continuously variable transmission, which is characterized by: