APPARATUS FOR PRODUCING ENDLESS METAL HOOPS OF A DRIVE BELT IN A CONTINUOUSLY VARIABLE TRANSMISSION

Abstract: Apparatus for producing endless metal hoops (W) of a drive belt in a continuously variable transmission comprising a base (2), a rotary shaft rotatably supported above the base and provided with a stepped member having different outer diameters corresponding to a predetermined difference in the circular lengths of a plurality of endless metal hoops constituting a carrier of the drive belt and being formed continuously in the axial direction thereof, a fixed shaft mounted above the base and arranged in parallel relation with the rotary shaft and rotatably suporting a suitable number of rollers opposed to the stepped member of the rotary shaft and having identical diameters, a slide base (14) mounted on the base and supporting the fixed shaft above the base in parallel relation with the rotary shaft and being adapted to slide on the base in such a manner as to move toward and apart from the rotary shaft, and means for moving the slide base in such a direction as to stretch the endless metal hoops wound around the stepped member of the rotary shaft and the rollers of the fixed shaft.

Description: APPARATUS FOR PRODUCING ENDLESS METAL HOOPS OF A DRIVE BELT IN A CONTINUOUSLY VARIABLE TRANSMISSION BACKGROUND OF THE IM5ENTICN This invention relates to an apparatus for producing endless metal hoops constituting a carrier of a drive belt in a continuously variable transmission of a belt driving type. In the continuously variable transmission of a belt driving type, a carrier is constituted of a multiple layer of endless metal hoops and V-shaped metal blocks are slidably and continuously attached to one or two carriers so as to form a drive belt. The drive belt is wound around two V-shaped belt pulleys to transmit torque from one belt pulley to another During operation of the continuously variable transmission, the V-shaped metal blocks are abutted against the partially conical drive surface forming a V-shaped groove of the V-shaped belt pulleys and are moved together with the carrier, in which the carrier is designed not to abut against the drive surface of the V-shaped belt pulleys, wherein the carrier is subject to a tensile force of the V-shaped blocks fitted into the V-shaped groove of the belt pulleys. Accordingly, it is necessary to uniformly distribute the tensile force applied to the endless metal hoops in order to endure a long-time use of the drive belt. For this necessity, the difference in the circular length of each endless metal hoops of the carrier is required to be within a predetermined value. Conventionally, for the above requirement, any suitable endless metal hoops having the predetermined value of the difference in the circular length thereof are selected from many produced endless metal hoops, which results in increased productive step of the endless metal hoops and their material cost. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an apparatus for producing endless metal hoops of a drive belt in a continuously variable transmission which may produce endless metal hoops having predetermined difference in their circular lengths. It is another object of the present invention to provide an apparatus for producing endless metal hoops of a drive belt in a continuously variable transmission which may eliminate production of excess endless metal hoops for a carrier, thereby reducing the material cost and the productive step of the endless metal hoops. The present invention provides an apparatus for producing endless metal hoops of a drive belt in a continuously variable transmission comprising a base, a rotary shaft rotatably supported above the base and provided with a stepped member having different outer diameters corresponding to a predetermined difference in the circular lengths of a plurality of endless metal hoops constituting a carrier of the drive belt and being formed continuously in the axial direction thereof, a fixed shaft mounted above the base and arranged in parallel relation with the rotary shaft and rotatably supporting a suitable number of rollers opposed to the stepped member of the rotary shaft and having identical diameters, a slide base mounted on the base and supporting the fixed shaft above the base in parallel relation with the rotary shaft and being adapted to slide on the base in such a manner as to move toward and apart from the rotary shaft, and means for moving the slide base in such a direction as to stretch the endless metal hoops wound around the stepped member of the rotary shaft and the rollers of the fixed shaft. Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an elevational view of the apparatus, partly broken away, according to the invention, and Figure 2 is a cross-sectional view taken along the line lI-Il of Figure 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to Figures 1 and 2, reference numeral 1 generally designates an apparatus for producing endless metal hoops which is provided with a rectangular base 2 having a predetermined thickness. A pair of slide guides 3 and 3A are mounted on the base 2 along both sides thereof. A fixed plate 4 is mounted on the upper surface of both the slide guides 3 and 3A at their one end or on their left-hand side as viewed in Figure l and is secured by a suitable number of bolts 5. A pair of stays 6 and 6A for fixedly supporting a rotary shaft 9 are secured to both ends of the fixed plate 4 by bolts 7 and are positioned by a pair of knock pins 8. The shaft member 9a of the rotary shaft 9 is rotatably supported at its one end by a bearing 11 mounted to the stay 6. The bearing 11 is removably fitted to the shaft member 9a. Another shaft member 9b of the rotary shaft 9 is rotatably supported at its other end by bearings 12 mounted to the stay UA. The end portion 9c of the rotary shaft 9 axially extends from the shaft member 9b and a nut 13 is screwed into the threaded portion of the end portion 9c for fixing the bearings 12, thereby preventing the movement of the rotary shaft 9 relative to the bearings 12 in the direction of the axis C1. As will be apparent from Figure 2, the axis C1 of the rotary shaft 9 is in right angles to the center line C as is drawn in the longitudinal direction of the base 2 and is in parallel relatic with the upper surface of the base 2. The rotary shaft 9 is formed with stepped members 10a --- 10h between both the stays 6 and 6A. In this embodiment, eight stepped members are provided so as to match with eight endless metal hoops WI --- W8 which constitute a carrier (not shown) of a drive belt in a continuously variable transmission. The stepped members 10a --- 10h have the same width as with each other and the outer diameters of the stepped members are determined in such a manner as to achieve a predetermined difference in the circular lengths of each endless metal hoop to be carried on each of the stepped members 10a --- 10h. The steppes member 10e positioned at the center of the rotary shaft 9 has the maximum diameter and the stepped member 10d adjacent to one side of the stepped member 10e has the diameter slightly smaller than that of the stepped member 10e. Further, the stepped member 10f adjacent to the other side of the stepped member 10e has the dames slightly smaller than that of the stepped member 10d. In this manner, the diameters of the stepped members decrease in the order of 10e, 10d, 10f, 10c, lOg, lob, 10h and 10a. A slide base 14 is supported by the slide guides 3 and 3A and is adapted to move in the direction right angles to the axis C1 of the rotary shaft 9, being guided by each side surface of the slide guides 3 and 3a. A pair of Stays 16 and 17 for mounting a fixed shaft 15 are provided on both sides of the slide base 14. Both of the stays 16 and 17 are secured to the side surfaces of the slide base 14 at its lower portion by bolts 19, and the stay 16 is adapted to be positioned by two knock pins 18. The fixed shaft 15 is provided with a collar 15a at its one end and the other end portion 15b of the fixed shaft 15 is inserted into the axial hole 16a of the stay 16. In the same way, one end portion on the collar side is inserted into the axial hole 17a of the stay 17. When the collar 15a is in contact with the end surface of the stay 17, the end portion 15b is slightly projected from the end. surface of the stay 16. A fixing plate 20 for fixing the fixed shaft 15 to the stay 16 has a concave portion 20a at its central portion to be formed into a hat-like shape. The concave portion 20a is adapted to receive the end portion 15b and the outer circumferential portion of the fixing plate 20 is fixed to the stay 16 by -four bolts 21. The central portion of the fixing plate 20 is fixed to the end portion lSb by two bolts 22. In this way, the fixed shaft 15 is secured through the fixing plate 20 to the stay 16. As is apparent from the drawings, the axis C2 of the fixed shaft 15 is parallel to the axis C1 of the rotary shaft 9 and the height from the upper surface 2a of the base 2 to the axis C2 is identical with that from the upper surface 2a of the base 2 to the axis C1. Disk-like rollers 23A --- 23H are carried on the fixed shaft 15 through radial bearings 24 and are arranged in opposed relation with the stepped members 10a --- .10h of the rotary shaft 9, respectively. The width of each roller 23A ---- 23H is smaller than that of each stepped member, and thrust bearings 25 are interposed between each roller. A thrust plate 26 is located between the stay 16 and the roller 23A, being fitted to the fixed shaft 15, and one end of the thrust plate 26 is attached to the stay 16. The thrust bearing 25 is also interposed between the thrust plate 26 and the roller 23A. In the same way, a thrust plate 26A is fitted to the fixed shaft 15 between the stay 17 and the roller 23H, and one end of the thrust plate 26A is attached to the stay 17. There is also provided the thrust bearing 25 between the thrust plate 26A and the roller 23H.* A rectangular support plate 27 for supporting a hydraulic cylinder 29 is fixed to the right-hand end surface of the base 2 as viewed in the drawings by a suitable number of bolts 28. The hydraulic cylinder 29 is mounted to the support plate 27 on the opposite side to the fixed shaft 15 through four rods 30. A connecting bolt 31 is provided on the tip of the rod 29a of the hydraulic cylinder 29 and is screwed into the slide base 14 at the central upper portion of the end surface 14a thereof. Thus, upon activation of the hydraulic cylinder 29, the slide base 14 is guided by the slide guides 3 and 3A and moves toward or away from the rotary shaft 9. In Figures 1 and 2, means for rotating the rotary shaft 9 such as a motor is not illustrated. In operation, on the first stage, the hydraulic cylinder 29 is activated and the slide base 14 is moved closely to the fixed plate 4 to the position where a circular metal band W for producing endless metal hoops is to be wound around the stepped members 10a 10h 10h of the rotary shaft 9 and the rollers 23A --- 23H of the fixed shaft 15. Then, the bolts 7 screwed into the stay 6 are loosened to remove the stay 6 from the fixed plate 4. In the same way, the bolts 19 screwed into the stay 16 and the bolts 22 screwed into the fixed shaft 15 are loosened to remove the stay 16 from the slide base 14. Then, circular metal bands W1 --- W8 having the same diameter and width are wound around the stepped members 10o --- 10h of the rotary shaft 9 and the rollers 23A --- 23H of the fixed shaft 15. Then, the stay 6 is positioned to the fixed plate 4 by means of the knock pins 8 and is secured to the fixed plate 4 by means of the bolts 7. In the same way, the stay 16 is positioned to the slide base 14 by means of the knock pins 18 to support the fixed shaft 15 and is secured to the slide base 14 by tightening the bolts 19 and to the fixed shaft 15 by tightening the bolts 22. After the slide base 14 is moved rightwardly as viewed in the drawings until each circular band W reaches its tensile condition, the rotary shaft 9 is rotated in the direction as depicted by an arrow in Figure 2 and a hydraulic pressure is gradually applied to the hydraulic cylinder 29 to further move the slide base 14 away from the fixed plate 4 and stretch each of the circular bands W to the extent that they will be yielded to cause a plastic deformation, in which since the circular band W is rotated with the stepped members of the rotary shaft 9 and the rollers of the fixed shaft 15, it may be uniformly stretched. In such a manner as is above-described, the stretched circular band W is formed into the endless metal hoops W1 - -- W8 having the difference in their circular lengths corresponding to the difference in the diameters of the stepped members 10a --- 10h of the rotary shaft 9. After the endless metal hoops are produced, the rotation of the rotary shaft 9 is stopped and then the hydraulic pressure of the hydraulic cylinder 29 is removed so as to eliminate the stretching force from the endless metal hoops W1 --- 8 Then, the stays 6 and 16 are detached from the apparatus 1 and the endless metal hoops W1 --- W8 are removed from the apparatus 1. Finally, the endless metal hoops are arranged and assembled in the order of their circular lengths to constitute a carrier for a drive belt. In a modified arrangement of the stepped members of the rotary shaft 9, the stepped member having the minimum diameter may be arranged in the central position of the rotary shaft and other stepped members are arranged adjacent to the central stepped member in the order of their diameters. In another arrangement of the stepped members of the rotary shaft 9, the stepped members may be arranged from one end of the rotary shaft to the other end thereof in the order of their diameters. It should be noted that the number of the stepped member are not limited to eight, and the number of the roller is not necessary to match with that of the stepped member. Moreover, the circular lengths of the circular bands W are not required to be equalized. While the invention has been shown and described in its preferre embodiment, it will be clear to those skilled in the arts to which it pertains that many changes and modifications may be made thereto without departing from the scope of the invention.

Claims: WHAT IS CLAIMED IS: 1. Apparatus for producing endless metal hoops of a drive belt in a continuously variable transmission comprising: a base; a rotary shaft rotatably supported above said base, said rotary shaft including a stepped member having different outer diameters corresponding to a predetermined difference in the circular lengths of a plurality of endless metal hoops constituting a carrier of the drive belt and being formed continuously in the axial direction thereof, a fixed shaft mounted above said base and arranged in parallel relation with said rotary shaft, said fixed shaft rotatably supporting a suitable number of rollers opposed to said stepped member of said rotary shaft and having identical diameters; ; a slide base mounted on said base and supporting said fixed shaft above said base in parallel relation with said rotary shaft, said slide base being adapted to slide on said base in such a manner as to move toward and apart from said rotary shaft; and means for moving said slide base in such a direction as to stretch said endless metal hoops wound around said stepped member of said rotary shaft and said-rollers of said fixed shaft. 2. The apparatus as defined in claim 1, wherein the first axis of said fixed shaft is parallel to the second axis of said rotary shaft and the height from the upper surface of said base to the first axis is identical with that from the upper surface of said base to the second axis. 3. The apparatus as defined in claim 1, wherein the width of said rollers of said fixed shaft is smaller than that of said stepped member, and further comprising a thrust bearing interposed between each of said rollers. 4. The apparatus as defined in claim 1, wherein said means for moving said slide base is a hydraulic cylinder. 5. The apparatus as defined in claim 5, wherein said hydraulic cylinder is attached through a support plate to the end surface of said base. 6. The apparatus as defined in claim 1, wherein said stepped member is arranged in such a manner that its diameter is in maximum at the central position of said rotary shaft and gradually decreases toward both ends of said rotary shaft. 7. The apparatus as defined in claim 1, wherein said endless metal hoops are circular and have identical diameters.

Inventors: KAKO, HIROYOSHI, KAMIMAE, HAJIME DAI-2-SEISHIN-SEIFU-HIGASHI-RYO, SUGIYAMA, HITOSHI
Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA
Application year: 1983
Main classification: B21D53
IPC codes: B21D25, B21D53