JP2009022990A - Method and device for correcting circumferential length of metallic ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for correcting the circumferential length of a metallic ring, capable of reliably correcting the circumferential length of a thin-plate endless metallic ring formed of maraging steel which is used for a belt for a continuously variable transmission, and providing the arc shape of the ring in one action. <P>SOLUTION: A metallic ring circumferential length device 1 comprises a driving roller 2 and a driven roller 3 which are relatively separated from each other and shiftable in the horizontal direction, and a straightening roller 4 which is located between the driving roller 2 and the driven roller 3, provided inward of a metallic ring W stretched around the driving roller 2 and the driven roller 3, across the displacement direction of the driving roller 2 and the driven roller 3, shiftable in the upwardly vertical direction extending the metallic ring W, and having the diameter of 15-30 mm. By displacing the straightening roller 4 in the upwardly vertical direction to extend the metallic ring W, the metallic ring W is corrected to the desired circumferential length, and the desired arc shape Wa in which the center part is outwardly projecting in sectional view in the width direction can be provided on an outer circumferential surface of the metallic ring W. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a metal ring circumference correction method and apparatus for correcting the circumference of a thin plate-like endless metal ring made of maraging steel used for a continuously variable transmission belt.

  A continuously variable transmission belt used for power transmission of a continuously variable transmission (CVT) is formed in a ring shape by a metal ring laminate formed by laminating a plurality of thin plate-like endless metal rings. A plurality of metal elements are bundled together. Each metal ring is formed to have a slightly different circumference in order to be able to be laminated in the radial direction.

  This type of metal ring laminate is manufactured as follows. First, end portions of maraging steel thin plates are welded to form a cylindrical drum. Next, a first solution treatment is performed on the drum in order to homogenize the hardness that is partially hardened by the heat during the welding. Next, the drum subjected to the first solution treatment is cut into a predetermined width and rolled to form a metal ring having a desired circumference. This desired circumferential length is a design value of the circumferential length that allows a plurality of metal rings to be laminated in the radial direction, and is set to a slightly different circumferential length in accordance with the order of lamination.

  Next, in order to restore the shape of the metal structure deformed by rolling, a second solution treatment is performed on the rolled metal ring. However, since the circumference of the metal ring that has been subjected to the second solution treatment is no longer coincident with the desired circumference, the circumference is corrected to the desired circumference by the circumference correction process. Therefore, this circumference correction process is extremely important for laminating the plurality of metal rings without interfering with each other when the metal ring laminate is formed.

  Next, the metal ring whose circumference has been corrected is subjected to an aging treatment and a nitriding treatment, thereby imparting a required hardness to the metal ring. Next, a metal ring laminated body is formed by laminating a plurality of metal rings having slightly different circumferential lengths in the radial direction.

  The circumference correction process is performed, for example, by a metal ring circumference correction device described in Patent Document 1 below. The metal ring circumferential length correcting device includes a driving roller and a driven roller around which a metal ring subjected to the second solution treatment is wound, and a correction roller that extends the metal ring. The drive roller and the driven roller can be wound around the metal ring in a relatively close state, and can be displaced in a relatively separated direction, for example, a horizontal direction. The correction roller is provided at a position between the driving roller and the driven roller and inside the metal ring wound around the driving roller and the driven roller, and intersects the displacement direction of the driving roller and the driven roller; The metal ring can be displaced in the extending direction, for example, in the vertically upward direction.

  When the circumference correction processing is performed by the metal ring circumference correction device, first, a second solution treatment is performed on the driving roller and the driven roller in a state where the driving roller and the driven roller are relatively close to each other. Hung around the metal ring. Next, the metal ring is tensioned by keeping the driving roller and the driven roller relatively apart from each other and holding them at a predetermined interval. Next, the metal ring is stretched and corrected to a desired peripheral length by displacing the correction roller vertically upward while the metal ring is in tension.

  By the way, the metal ring has a cross-sectional view in the width direction in order to facilitate the maintenance of the laminated state when a plurality of the metal rings are laminated in the radial direction to form a metal ring laminate. Thus, it is desirable that the central portion has an arc shape that is convex outward.

  Therefore, it is conceivable to use a metal ring circumferential length correcting device in which the outer peripheral surface of the correction roller has an arc shape in which the central portion is convex outward in a cross-sectional view in the width direction. When the circumference correction processing is performed by the metal ring circumference correction device, the circumference of the metal ring is corrected and the metal ring is corrected by displacing the correcting roller in the vertical upward direction and pulling and extending the metal ring. It is anticipated that the arc shape will be given to the outer peripheral surface.

However, in this metal ring circumferential length correction device, there are cases where a desired arc shape cannot be imparted to the metal ring, so that the metal ring circumferential length can reliably perform both the circumferential length compensation and the arc shape imparting. A correction method and apparatus are desired.
Japanese Patent Laid-Open No. 11-290971

  In view of the above, the present invention provides a metal ring capable of reliably performing circumferential correction and arc shape application of a thin plate-like endless metal ring made of maraging steel used for a continuously variable transmission belt. It is an object of the present invention to provide a circumference correction method and an apparatus therefor.

  The inventor of the present application has intensively studied the reason why the metal ring circumference correcting device cannot give a desired arc shape to the metal ring. It has been found that the contribution of the diameter is greater than the surface shape and that the straightening roller needs to have a specific range of diameters.

  Therefore, in order to achieve the above object, the metal ring circumference correction method of the present invention is a metal ring circumference correction for correcting the circumference of a thin plate-like endless metal ring made of maraging steel used for a continuously variable transmission belt. In the method, the metal ring is wound around the drive roller and the driven roller relatively close to each other, and the drive roller and the dependent roller are displaced in a relatively separated direction so that the drive roller and the driven roller are spaced apart from each other. And a correction roller provided on the inner side of the metal ring wound around the driving roller and the driven roller and having a diameter in a predetermined range is defined as a displacement direction of the driving roller and the driven roller. The metal ring is displaced in the direction of crossing and extending, and the metal ring is pulled and stretched.

  According to the present invention, the metal ring can be corrected to a desired circumference by displacing the correction roller in the direction and pulling and stretching the metal ring, and at the same time, the correction roller is in a specific range. By providing this diameter, it is possible to give a desired arc shape in which the central portion is convex outward in a cross-sectional view in the width direction on the outer peripheral surface of the metal ring. That is, the circumference correction of the metal ring and the provision of the arc shape can be reliably performed with one behavior. Further, when the metal ring is stretched by displacing the correction roller in the direction, since the residual stress in the ring circumferential direction is applied to the metal ring, the metal when the continuously variable transmission belt B rotates. The fatigue strength of the ring is improved.

  As the diameter of the straightening roller is smaller, the outer peripheral surface of the metal ring can be provided with an arc shape having a larger protrusion amount toward the outer peripheral side, and as the diameter is larger, an arc shape having a smaller protrusion amount can be provided. it can. Therefore, in the metal ring circumference correction method of the present invention, it is preferable that the operation of pulling and stretching the metal ring is performed by the correction roller having a diameter in the range of 15 to 30 mm. Since the straightening roller has a diameter in the above range, the peripheral length of the metal ring can be corrected and the arc shape can be imparted more reliably with one behavior.

  When the operation is performed by the straightening roller having a diameter of less than 15 mm, the amount of protrusion of the obtained circular arc shape to the outer peripheral side becomes excessive, and thus a plurality of the metal rings are laminated in the radial direction. When a plurality of metal elements arranged in an annular shape are to be bundled together by the metal ring laminate formed in this way, the metal ring laminate cannot interfere with the metal elements and be bundled together. Sometimes. In addition, when the operation is performed by the correction roller having a diameter exceeding 30 mm, the protrusion amount is excessively small, and the stacked state is maintained when the plurality of metal rings are stacked in the radial direction. It may not be possible.

  A smaller residual stress is applied to the metal ring as the diameter of the correction roller is smaller, and a smaller residual stress is applied as the diameter is larger. By applying a residual stress in the ring circumferential direction with an appropriate range of size to the metal ring, when the continuously variable transmission belt formed by laminating the metal rings is rotated, The fatigue resistance can be improved. However, it should be noted that depending on the diameter of the straightening roller, excessive residual stress is applied to the metal ring, and this excessive residual stress may reduce the fatigue strength of the metal ring.

  The metal ring circumference correction method of the present invention is a metal ring circumference correction device for correcting the circumference of a thin plate-like endless metal ring made of maraging steel used for a continuously variable transmission belt. The drive ring and the driven roller that can be wound around the metal ring in a state and can be displaced in a relatively separated direction, and a position between the drive roller and the driven roller, and the drive roller and the driven roller A straightening roller provided on the inner side of the metal ring wound around the roller, the straightening roller being displaceable in a direction crossing a displacement direction of the driving roller and the driven roller and extending the metal ring; Can be implemented by a device characterized by having a predetermined range of diameters.

  The straightening roller preferably has a diameter in the range of 15 to 30 mm.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a part of a continuously variable transmission belt. FIG. 2 is an explanatory view schematically showing a metal ring circumferential length correcting apparatus according to an embodiment of the present invention.

  A continuously variable transmission belt B shown in FIG. 1 is formed by integrally bundling a metal element laminate composed of a plurality of metal elements E by a metal ring laminate R formed by laminating a plurality of metal rings W. It is a thing. This metal element laminate is formed by laminating plate-like metal elements E each having a pair of recesses in the thickness direction, and is inserted into the recesses Ea of the metal element laminate. It is bundled together via the metal ring laminate R.

  The metal ring laminate R is formed by laminating a plurality of metal rings W having different circumferential lengths in the radial direction. The metal ring W is a thin plate-like endless metal ring made of maraging steel, and has an arcuate shape Wa whose outer peripheral surface is convex in the cross-sectional view in the width direction. Thereby, when the metal ring laminated body R is formed by laminating a plurality of metal rings W, the arc shapes Wa of the metal rings W are engaged with each other and the laminated state is easily maintained.

  In the present embodiment, the metal ring W is formed as follows. First, a cylindrical drum is formed by welding the ends of thin sheets of maraging steel. Since the drum is partially hardened by heat during the welding, the drum is first subjected to a first solution treatment to homogenize the hardness. This first solution treatment is performed, for example, by holding the drum in a vacuum furnace at a temperature of 760 to 850 ° C. for 0.5 to 4 hours.

  Next, the drum subjected to the first solution treatment is taken out of the vacuum furnace, cut into a predetermined width, and rolled at a reduction ratio of 40 to 50%, whereby a metal ring W having a desired circumference is obtained. It is formed. The desired circumferential length is a design value of the circumferential length that allows a plurality of metal rings W to be stacked in the radial direction, and is set to a slightly different circumferential length in accordance with the stacking order. Since the metal ring W whose circumference has been corrected has a deformed metal structure due to the rolling, the metal ring W is then subjected to a second solution treatment to recrystallize the rolled crystal, and the rolling The shape of the deformed metal structure is restored. This second solution treatment is performed, for example, by holding the metal ring W in a vacuum furnace at a temperature of 760 to 850 ° C. for 0.5 to 4 hours.

  Since the circumference of the metal ring W that has been subjected to the second solution treatment does not match the desired circumference, the metal ring W is next carried out of the vacuum furnace, and the circumference is corrected. In addition, in order to easily maintain the laminated state when the metal rings W are laminated in the radial direction as the metal ring laminated body R, the metal ring W is centered on the outer circumferential surface of the metal ring W in a cross-sectional view in the width direction. A circular arc shape Wa is imparted so that the portion is convex outward.

  Therefore, in the present embodiment, the circumference correction and the arc shape imparting to the metal ring W are performed by the metal ring circumference correction apparatus 1 shown in FIG.

  2A corrects the circumference of the metal ring W constituting the metal ring laminated body R shown in FIG. 1 and applies an arc shape Wa to the outer circumferential surface of the metal ring W. The metal ring circumference correction apparatus 1 shown in FIG. It is a device to give. The metal ring circumference correction device 1 includes a drive roller 2 and a driven roller 3 around which the metal ring W is wound, and a correction roller 4 that extends the metal ring W.

  The drive roller 2 and the driven roller 3 can be wound around the metal ring W in a relatively close state, and can be displaced in a relatively separated direction. The drive roller 2 is configured to be rotatable by a drive unit (not shown) such as a motor. Further, the driven roller 3 is freely displaceable in the horizontal direction away from the driving roller 2.

  The correction roller 4 is provided at a position between the driving roller 2 and the driven roller 3 and inside the metal ring W wound around the driving roller 2 and the driven roller 3. Further, the correction roller 4 is displaceable in a vertically upward direction that intersects the displacement direction (horizontal direction) of the driving roller 2 and the driven roller 3 and extends the metal ring W. The diameter D of the correction roller 4 is in a range where an arc shape Wa can be imparted to the outer peripheral surface of the metal ring W when displaced, and is preferably in the range of 15 to 30 mm, for example 30 mm.

  The correction roller 4 may have a cylindrical shape, or as shown in FIG. 2B, which is a cross-sectional view taken along line AA in FIG. The central part may be formed in an arc shape that is convex outward.

  Next, the operation of the metal ring circumference correction device 1 will be described with reference to FIG. First, in a state where the driven roller 3 is displaced in the horizontal direction and is brought close to the driving roller 2, the metal ring W subjected to the second solution treatment is hung around the driving roller 2 and the driven roller 3. Next, the driven roller 3 is displaced in the horizontal direction so as to be separated from the driving roller 2, and the metal ring W is tensioned by holding the driving roller 2 and the driven roller 3 at a predetermined interval.

  Next, by rotating the drive roller 2 while the metal ring W is in tension, the metal ring W is rotated around the drive roller 2 and the driven roller 3. Next, the actual circumference of the metal ring W is calculated based on the inter-axis distance between the driving roller 2 and the driven roller 3 while the metal ring W is circulated. Next, the difference between the desired circumference of the metal ring W and the calculated actual circumference of the metal ring W is obtained, and the displacement amount x of the correction roller 4 is determined from this difference.

  Next, the correction roller 4 is urged vertically upward. Thereby, the metal ring W is pulled and stretched by the correction roller 4 and is plastically deformed. As a result, the correction roller 4 gradually displaces vertically upward in response to the plastic deformation from the state indicated by the phantom line in FIG.

  Next, when the displacement amount of the correction roller 4 reaches the displacement amount x determined by the difference between the desired circumference of the metal ring W and the calculated actual circumference of the metal ring W, the displacement amount x is set to After holding for a predetermined time, the correction roller 4 is displaced vertically downward. Then, when the correction roller 4 returns to the initial position, the rotational driving of the driving roller 2 is stopped. Next, the tension of the metal ring W is released by bringing the driven roller 3 close to the drive roller 2. Next, with the tension of the metal ring W relaxed, the metal ring W is removed from the drive roller 2 and the driven roller 3 to complete the operation.

  According to the metal ring circumferential length correcting apparatus 1 of the present embodiment, the correcting roller 4 is displaced by the displacement amount x to extend the metal ring W, thereby correcting the metal ring W to a desired circumferential length and simultaneously correcting the roller. When 4 has a diameter D of, for example, 30 mm, a desired arc shape Wa having a central portion protruding outward in a cross-sectional view in the width direction can be provided on the outer peripheral surface of the metal ring W. That is, the peripheral length correction of the metal ring W and the circular arc shape can be reliably performed with one behavior. In addition, when the metal roller is pulled and stretched by displacing the correction roller in the direction, a residual stress in the ring circumferential direction having an appropriate range of magnitude is applied to the metal ring.

  Next, the metal ring W, which has been corrected to a desired circumference by the metal ring circumference correction device 1 and has a desired arc shape, is subjected to an aging treatment and a nitriding treatment to give a required hardness. The aging treatment is performed, for example, by holding the metal ring W in a vacuum furnace at a temperature of 400 to 500 ° C. for 2 to 3 hours. The nitriding treatment is performed, for example, by holding the aging-treated metal ring W at a temperature of 400 to 500 ° C. for 0.5 to 10 hours in an inert gas atmosphere containing ammonia gas.

  Since the metal ring W formed as described above is provided with a desired arc shape Wa on the outer peripheral surface by the metal ring peripheral length correcting device 1, a plurality of metal rings W having slightly different peripheral lengths are mutually connected in the radial direction. When the metal ring laminated body R is formed by laminating, the arcuate shapes Wa can be engaged with each other so that the laminated state of the metal rings W can be easily maintained.

The perspective view which shows a part of belt for continuously variable transmission. Explanatory drawing which shows typically the metal ring periphery correction | amendment apparatus of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Metal ring circumference correction device, 2 ... Drive roller, 3 ... Driven roller, 4 ... Straightening roller, D ... Diameter of straightening roller, B ... Belt for continuously variable transmission, W ... Metal ring.

Claims (4)

In the metal ring circumference correction method for correcting the circumference of a thin plate-like endless metal ring made of maraging steel used for a continuously variable transmission belt,
The metal ring is wound around the drive roller and the driven roller relatively close to each other, and the drive roller and the dependent roller are displaced in a relatively separated direction,
A correction roller provided at a position between the driving roller and the driven roller and inward of the metal ring wound around the driving roller and the driven roller, and having a predetermined range of diameters, is driven. A metal ring circumferential length correction method comprising: displacing the metal ring in a direction extending and intersecting a displacement direction of the roller and the driven roller, and pulling and extending the metal ring.   2. The metal ring circumferential length correction method according to claim 1, wherein the operation of pulling and stretching the metal ring is performed by the straightening roller having a diameter in a range of 15 to 30 mm. In a metal ring circumference correction device for correcting the circumference of a thin plate-like endless metal ring made of maraging steel used for a continuously variable transmission belt,
A driving roller and a driven roller that can be wound around the metal ring in a relatively close state and are displaceable in a relatively separated direction;
A position between the driving roller and the driven roller and inward of the metal ring wound around the driving roller and the driven roller, and intersects a displacement direction of the driving roller and the driven roller. And a straightening roller displaceable in the direction of extending the metal ring,
The metal ring circumferential length correcting device, wherein the straightening roller has a diameter in a predetermined range.   4. The metal ring circumferential length correcting device according to claim 3, wherein the straightening roller has a diameter in a range of 15 to 30 mm.

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