JP5621685B2 - Manufacturing method of thin plate-like endless metal ring - Google Patents

Description

  The present invention relates to a method of manufacturing a thin plate-like endless metal ring.

  Conventionally, this kind of endless metal ring is used for a transmission belt for power transmission of a continuously variable transmission (CVT). A continuously variable transmission belt is composed of a ring laminate formed by laminating a plurality of endless metal rings with slightly different circumferential lengths in the radial direction, and a plurality of ring-shaped bundles bound together by the ring laminate. It is composed of the elements. The continuously variable transmission belt is wound around the driving pulley and the driven pulley, and rotates along the driving pulley and the driven pulley by a pressing force between the elements in contact with each other, and the driving force is transferred from the driving pulley to the driven pulley. To communicate. As a manufacturing apparatus for such an endless metal ring, for example, a circumferential length correcting apparatus described in Patent Document 1 is known.

  The circumferential length correcting device described in this Patent Document 1 is such that a driving roller and a driven roller and a part of the circumferential direction of an endless metal ring wound between these rollers are locally directed from the inside to the outside. It is comprised from the correction | amendment roller for pressing. By using this circumference correction device, the endless metal ring is given an arc shape that is convex on the outer circumference side in the cross section in the width direction. The endless metal ring is easily held in a laminated state when a plurality of endless metal rings are laminated.

However, in the endless metal ring manufactured by the peripheral length correcting device described in Patent Document 1, the inner peripheral surface side of the endless metal ring is locally pressed toward the outer peripheral side, whereby the endless metal ring Since tensile residual stress is applied to the inner peripheral portion, there is a problem that the strength of the inner peripheral portion has no margin with respect to the required strength, and durability is lowered.
Therefore, the present applicant has proposed a method for manufacturing a laminated ring that solves this problem in the application of Japanese Patent Application No. 2010-048250.
FIG. 19A shows a manufacturing method of this laminated ring. In the residual stress applying step performed after the peripheral length adjusting step of adjusting the peripheral length of the band-shaped metal member 120, the gap between the two fixed rollers 680 is shown. The belt-shaped metal member 120 wound is pressed with a pressing force F from the outer peripheral surface side to the inner peripheral surface side of the belt-shaped metal member 120 using the moving roller 700, thereby The compressive residual stress is applied to the peripheral portion to improve the durability of the band-shaped metal member 120.
FIG. 20 is a diagram illustrating a distribution of stress generated in the band-shaped metal member 120 in the fixed roller 680 portion in a state where the moving roller 700 is retracted from the band-shaped metal member 120 as illustrated in FIG. In this state, the stress generated in the band-shaped metal member 120 in the fixed roller 680 portion is within the range of yield points −σy to σy of the band-shaped metal member 120.

JP 2009-22991 A

However, the previously proposed laminated ring manufacturing method has the following problems.
That is, as shown in FIG. 21A, the tensile force T by the two fixed rollers 680 is released from the state shown in FIG. 19B, and the band-shaped metal member 120 is removed from the two fixed rollers 680. Then, since the stress generated by the tensile force T is eliminated, as shown in FIG. 21B, the stress generated in the band-shaped metal member 120 on the inner peripheral surface side of the band-shaped metal member 120 is the yield point −σy. The part that exceeds is generated. As a result, as shown in FIG. 21 (c), the band-shaped metal member 120 portion wound around the two fixed rollers 680 is plastically deformed, causing distortion such as constriction, and the durability of the band-shaped metal member 120. There was a problem such as a significant drop.

  In order to solve such a problem, it can be solved by increasing the radius of the two fixed rollers 680 or decreasing the pressing force F by the moving roller 700, but when the radius of the two fixed rollers 680 is increased. In this case, an ideal residual stress cannot be applied to the outer peripheral surface side of the band-shaped metal member 120, and if the pressing force F by the moving roller 700 is reduced, an ideal residual stress is applied to the inner peripheral surface side of the band-shaped metal member 120. Thus, there is a problem that the durability of the band-shaped metal member 120 is significantly lowered.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for manufacturing a thin plate-like endless metal ring that can provide a metal ring having excellent durability.

In order to solve the above problems, the method for manufacturing a thin plate-like endless metal ring of the present invention has the following configuration.
(1) A method for manufacturing a thin plate-like endless metal ring, wherein an adjustment step of adjusting a peripheral length of the metal ring by a peripheral length adjusting roller disposed on an inner peripheral side of the metal ring, and an outer periphery of the metal ring An outer roller arranged on the side, applying a residual stress to the metal ring, and in a state in which a constant tension is applied in the circumferential direction of the metal ring, the diameter is larger than the diameter of the circumferential length adjusting roller And a replacement process for replacing the large-diameter roller.

(2) In the manufacturing method of a thin plate-like endless metal ring described in (1), the circumferential length adjusting roller is configured by two rollers arranged at intervals, and the large-diameter roller is the 2 It is arranged on the inner peripheral side of the metal ring between the peripheral length adjusting rollers.
(3) In the method for manufacturing a thin plate-like endless metal ring described in (1), the large-diameter roller includes a large-diameter portion, a small-diameter portion having a smaller diameter, and gradually from the small-diameter portion toward the large-diameter portion. And a spiral guide portion having an enlarged diameter.

The operation and effect of the manufacturing method of the thin plate-like endless metal ring of the present invention having the above-described configuration will be described.
(1) A method for manufacturing a thin plate-like endless metal ring, wherein an adjustment step of adjusting a peripheral length of the metal ring by a peripheral length adjusting roller disposed on an inner peripheral side of the metal ring, and an outer periphery of the metal ring An outer roller arranged on the side, applying a residual stress to the metal ring, and in a state in which a constant tension is applied in the circumferential direction of the metal ring, the diameter is larger than the diameter of the circumferential length adjusting roller Therefore, it is possible to provide a metal ring with improved durability.

(2) In the manufacturing method of a thin plate-like endless metal ring described in (1), the circumferential length adjusting roller is configured by two rollers arranged at intervals, and the large-diameter roller is the 2 Since the metal ring is disposed on the inner peripheral side between the peripheral length adjusting rollers, it is possible to provide a metal ring with improved durability using a simple mechanism.

(3) In the method for manufacturing a thin plate-like endless metal ring described in (1), the large-diameter roller includes a large-diameter portion, a small-diameter portion having a smaller diameter, and gradually from the small-diameter portion toward the large-diameter portion. Therefore, the metal ring with improved durability can be provided using a simple mechanism.

FIG. 3 is a perspective view showing a part of the transmission belt in the circumferential direction of the vehicle belt-type continuously variable transmission according to the first embodiment. It is a perspective view which shows it with a cross section of the width direction about a strip | belt-shaped metal member. It is a figure which shows distribution of the thickness direction of the residual stress of the direction perpendicular | vertical to the cross section of a strip | belt-shaped metal member. It is process drawing for demonstrating the manufacturing process of a lamination | stacking ring. It is a figure which shows notionally the circumference adjustment apparatus used at the circumference adjustment process of FIG. It is a figure which shows distribution of the thickness direction of the total stress which added the tensile stress and bending stress just before completion | finish of the circumference adjustment process of FIG. It is a figure which shows distribution of the thickness direction of the residual stress which remains in the strip | belt-shaped metal member made into the free state. It is a figure which shows notionally the residual stress provision apparatus used in the residual stress provision process P9 of FIG. It is a figure which shows the II sectional expanded sectional view in FIG. It is a figure which shows distribution of the thickness direction of the total stress given to a strip | belt-shaped metal member in the residual stress provision process of FIG. It is a figure explaining the change of the yield stress of a strip | belt-shaped metal member after the residual stress provision process of FIG. (A) is a figure which shows notionally the initial state of a replacement process, (b) is a figure which shows notionally the completion | finish state of a replacement process. (A) is a figure which shows the tensile stress which has arisen in the strip | belt-shaped metal member after completion | finish of a replacement | exchange, and the bending stress by a replacement | exchange roller, (b) is the total which has arisen in the strip | belt-shaped metal member after a replacement | exchange completion | finish The figure which shows stress, (c) is a figure which shows the total stress which arises in the strip | belt-shaped metal member after cancelling | releasing provision of tension | tensile_strength. It is a figure which shows a replacement processing apparatus concretely. Of the residual stress remaining in the band-shaped metal member in the free state after the residual stress applying step in FIG. 4, due to the stress excluding the residual stress applied to the band-shaped metal member in the circumferential length adjusting step in FIG. 4. It is a figure which shows distribution of the thickness direction of the residual stress. It is a figure which shows distribution of the thickness direction of the stress which remains in the strip | belt-shaped metal member made into the free state after the residual stress provision process of FIG. It is a figure which shows distribution of the thickness direction of the residual stress provided to a strip | belt-shaped metal member by the nitriding process of FIG. It is explanatory drawing which shows the replacement processing apparatus which concerns on another Example. (A) Explanatory drawing which shows the residual stress provision apparatus which concerns on a previous application, (b) is explanatory drawing explaining operation | movement of a residual stress provision apparatus. FIG. 20 is a distribution diagram of stress generated in the band-shaped metal member of the fixed roller portion in the state of FIG. (A) is explanatory drawing which shows the residual stress provision apparatus in the state which cancelled | released the tension | tensile_strength provided to the strip | belt-shaped metal member, (b) is distribution of the stress which arises in the strip | belt-shaped metal member of the fixed roller part in the state of (a). FIG. 4C is a diagram showing the band-shaped metal member removed from the residual stress applying device.

(Embodiment 1)
Hereinafter, embodiments of a method for producing a thin plate-like endless metal ring according to the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are drawn with simplified or modified exaggeration as appropriate, and the dimensional ratios and shapes of the respective parts are not necessarily the same as those in the embodiments.

  FIG. 1 is a perspective view showing a part in the circumferential direction of a transmission belt 10 of a belt-type continuously variable transmission for a vehicle using a thin plate-like endless metal ring manufactured by a method for manufacturing a thin plate-like endless metal ring according to the present invention. It is. In FIG. 1, a transmission belt 10 includes a pair of endless annular band-like metal members (corresponding to the thin plate-like endless metal rings of the present invention) 12 that are laminated in close contact with each other. A laminated ring 14 and a plurality of metal elements 18 each made of a plate-like metal continuously connected in the thickness direction along the laminated ring 14 are provided.

  A pair of ring holding grooves 20 extending substantially horizontally toward the center in the width direction are formed on both side surfaces of the metal element 18 in the width direction. The pair of laminated rings 14 are respectively inserted into a pair of ring holding grooves 20 formed in the plurality of metal elements 18 in order to support the plurality of metal elements 18. The laminated ring 14 is formed by, for example, laminating a plurality of strip-shaped metal members 12 that are adjusted so that the circumferential length gradually increases from the inner circumferential side toward the outer circumferential side, in order from the inner circumferential side. In FIG. 1, for convenience, the laminated ring 14 including the three strip-shaped metal members 12 is illustrated, but may be configured by six or ten strip-shaped metal members 12.

  FIG. 2 is a perspective view showing one band-shaped metal member 12 of the plurality of band-shaped metal members 12 constituting the laminated ring 14 together with a cross section in the width direction. In FIG. 2, the strip-shaped metal member 12 is made of, for example, steel such as maraging steel or stainless steel. And the strip | belt-shaped metal member 12 is formed so that the cross section of the width direction may become circular arc shape (crowning) which forms convex shape on the outer peripheral side (upper side in FIG. 2). Thereby, when a plurality of the band-shaped metal members 12 are laminated, the inner peripheral surface 22 and the outer peripheral surface 24 are respectively engaged with the outer peripheral surface and the inner peripheral surface of the band-shaped metal member provided on the inner peripheral side and the outer peripheral side, respectively. By doing so, the stacked state of each other can be easily maintained.

  FIG. 3 is a diagram showing the distribution in the thickness direction of the residual stress σ (MPa or N / mm 2) in the direction perpendicular to the cross section of the band-shaped metal member 12 in the free state. The strip-shaped metal member 12 has a thickness t as shown in FIG. 2, and t in FIG. 3 corresponds to this. As shown in FIG. 3, the compressive residual stress shown on the negative side (left side) from the broken line indicating σ = 0 remains on the outer peripheral surface 24 side and the inner peripheral surface 22 side in the thickness direction of the band-shaped metal member 12. doing. And the tensile residual stress shown by the positive side (right side) rather than the broken line which shows (sigma) = 0 remains in the center part of the thickness direction of the strip | belt-shaped metal member 12. FIG. The two-dot chain line in FIG. 3 indicates the distribution in the thickness direction of the residual stress required on the compression side at the minimum when the laminated ring 14 of the transmission belt 10 is composed of, for example, six belt-shaped metal members 12. If the residual stress of the metal member 12 is on the compression side, that is, the left side of FIG. 3 with respect to the residual stress distribution indicated by the two-dot chain line, the band-like metal member 12 has the necessary strength. In the band-shaped metal member 12 of the present embodiment, the residual stress is distributed on the compression side from the residual stress indicated by the two-dot chain line at any position in the thickness direction, so the laminated ring 14 of the transmission belt 10 shown in FIG. For example, it has a preset strength required when it is composed of six strip-shaped metal members 12.

  FIG. 4 is a process diagram for explaining a manufacturing process of the laminated ring 14 shown in FIG. Hereinafter, a method for manufacturing the laminated ring 14 will be described with reference to the process diagram of FIG.

  In FIG. 4, first, in the steel strip cutting step P1, a steel strip 30 such as maraging steel or stainless steel is cut into a predetermined length, and a flat plate 32 is formed.

  Next, in the welding process P <b> 2, one and the other cut surfaces of the flat plate 32 are welded together to form the cylindrical member 34.

  Next, in the first solution heat treatment step P3, in order to homogenize the hardness of the cylindrical member 34 in which the vicinity of the welded portion is partially hardened by the heat during welding in the welding step P2, the first cylindrical member 34 is subjected to the first solution treatment step P3. The solution treatment of is performed.

  Next, in the cylindrical member cutting step P4, the cylindrical member 34 is cut in a direction orthogonal to the axial center every predetermined length in the axial direction, and a plurality of short cylindrical members 36 are formed.

  Next, in the barrel polishing step P5, all or a part of the short cylindrical member 36 is put into a predetermined container that rotates or vibrates together with an abrasive and is polished.

Next, in the rolling process P6, the polished short cylindrical member 36 is rolled to a predetermined thickness, and the annular member 38 is formed.

Next, in the second solution treatment step P7, in order to restore the metal structure of the annular member 38 deformed by rolling in the rolling step P6, the annular member 38 is subjected to a second solution treatment. The

Next, in the circumference adjusting step P8, the annular member 38 subjected to the second solution treatment is adjusted to a predetermined circumference. FIG. 5 is a diagram conceptually showing the peripheral length adjusting device used in the peripheral length adjusting step P8 of FIG. In FIG. 5, the circumferential length adjusting device 40 is fixed to a fixed roller 42 that is fixed around the axis C <b> 1 and rotatable around the axis C <b> 2 parallel to the axis C <b> 1. And a moving opening 44 provided so as to be able to approach and separate. The outer peripheral surfaces of the fixed roller 42 and the moving port holder 44 are each formed in an arc shape having a convex shape on the outer peripheral side in a cross section passing through the shaft centers C1 and C2.

  In the circumferential length adjusting step P8, the circumferential length adjusting device 40 configured as described above is used, and the belt-shaped metal member 12 is wound around the fixed roller 42 and the moving roller 44 without slack, and the electric motor (FIG. 14). When the moving roller 44 is driven to rotate by the servo motor 443), the belt-shaped metal member 12 is rotated in the circumferential direction as indicated by an arrow c, while the moving roller 44 is fixed to the fixed roller 42 as indicated by an arrow b. The band-shaped metal member 12 is stretched in the circumferential direction by being separated from the belt. In the present embodiment, based on a relationship obtained experimentally in advance, based on the displacement Y from the original position of the moving roller 44 indicated by a one-dot chain line in FIG. Adjusted to the value. The belt-shaped metal member 12 is formed in an arc shape in which the cross section in the width direction is convex on the outer peripheral side by transferring the shape of the outer peripheral surface of the fixed roller 42 and the moving roller 44 when adjusting the peripheral length. .

FIG. 6 is a diagram showing a distribution in the thickness direction of the total stress σ1 obtained by adding the tensile stress σTA and the bending stress σbA immediately before the end of the circumference adjusting step P8 of the band-shaped metal member 12. Immediately before the end of the circumferential length adjusting step P8, the belt-shaped metal member 12 is subjected to a tensile stress σTA by the moving roller 44 shown by a one-dot chain line in FIG. 6 and a bending by the moving roller 44 shown by a two-dot chain line in FIG. Stress σbA is applied.
The bending stress σbA is expressed by the following formula (1). In Equation (1), E is the Young's modulus of the band-shaped metal member 12, t is the thickness immediately before the end of the circumferential length adjusting process P 8 of the band-shaped metal member 12, and rA is the radius of the moving roller 44.
σbA = E * (t / 2) / (rA + (t / 2)) (1)

  In FIG. 6, the yield region S1 in which the total stress σ1 exceeds the yield stress σy0 of the strip-shaped metal member 12 is a region where strain remains even if the total stress σ1 is removed. The yield stress σy0 is an eigenvalue determined by the material of the band-shaped metal member 12. Immediately before the end of the circumferential length adjusting step P8, the band-shaped metal member 12 is plastically deformed in the circumferential direction so that the outer peripheral side is closer to the outer peripheral side than the neutral surface N, and the inner peripheral side is elastically deformed from the neutral surface N. Is done.

  When the belt-like metal member 12 is brought into a free state by removing the tension from the above state, the belt-like metal member 12 is deformed so as to restore the strain, but the strain remains on the outer peripheral side of the neutral surface N. And in the case of the said deformation | transformation, the outer peripheral part of the strip | belt-shaped metal member 12 is compressed to the circumferential direction, so that the outer peripheral side with larger residual strain is large. FIG. 7 is a diagram showing the distribution in the thickness direction of the stress remaining on the band-shaped metal member 12 in the free state, that is, the residual stress σrA. As shown in FIG. 7, a large compressive residual stress remains on the outer peripheral portion of the band-shaped metal member 12 toward the outer peripheral side, and a predetermined tensile residual stress σrA1 remains on the inner peripheral portion.

  As described above, in this embodiment, the bending stress σbA applied to the band-shaped metal member 12 can be adjusted by changing the radius rA of the moving roller 44, and the relatively small diameter fixed roller 42 and moving roller 44 are used. By doing so, an ideal bending stress σbA can be applied to the outer peripheral side of the band-shaped metal member 12. Thereby, a compressive residual stress that is larger on the outer peripheral side ideally remains on the outer peripheral portion of the band-shaped metal member 12, and the durability of the band-shaped metal member 12 is improved.

  Returning to FIG. 4, after the circumferential length adjusting step P <b> 8, in the residual stress applying step P <b> 9, compressive residual stress is applied to the inner peripheral portion of the band-shaped metal member 12 whose peripheral length is adjusted. FIG. 8 is a diagram conceptually showing the residual stress applying device 66 used in the residual stress applying step P9. In FIG. 8, the residual stress applying device 66 includes an outer peripheral surface of the band-shaped metal member 12 that is wound around the peripheral length adjusting device 40 shown in FIG. The moving roller 70 is provided so as to be able to move in a direction in which 24 is locally pressed toward the inner peripheral side and in a direction away from the band-shaped metal member 12 opposite thereto. The moving roller 70 is rotatable about an axis C1 parallel to the axis C1 of the fixed roller 42 and the axis C2 of the fixed roller 42.

FIG. 9 is a cross-sectional view showing a cross section taken along line II of the residual stress applying device 66 of FIG. As shown in FIG. 9, the residual stress applying device 66 is fixed to the hydraulic actuator 74 fixed to the support wall 72 and the distal end portion of the output rod 76 of the hydraulic actuator 74, and the rotation of the moving port 1. By measuring the axial force acting on the support member 80 that rotatably supports both ends of the shaft 78 and the output rod 76 of the hydraulic actuator 74, the second acting on the band-shaped metal member 12 from the moving roller 70. And a load cell 82 for indirectly measuring the load F2. When the hydraulic actuator 74 is supplied with hydraulic pressure to the first hydraulic chamber 84, the output rod 76 and the moving roller 70 connected thereto are moved to the outer periphery of the band-shaped metal member 12 indicated by an arrow d in FIGS. The surface 24 is moved in the direction of pressing toward the inner peripheral surface 22 side, and the hydraulic pressure is supplied to the second hydraulic chamber 86, whereby the output rod 76 and the moving roller 70 connected thereto are moved as shown in FIGS. Is moved away from the band-shaped metal member 12 indicated by an arrow e. Further, the hydraulic actuator 74 is based on a signal representing the second load F2 supplied from the load cell 82 and is more than the neutral plane N (see FIG. 10) of the bending stress σbc caused by the moving roller 70 in the band-shaped metal member 12. In order to apply a stress to the band-shaped metal member 12 in advance so that only the inner peripheral side is plastically deformed and the plastic roller is deformed only by the moving roller 70 without being plastically deformed by the fixed roller 42 and the moving port 1. The second load F <b> 2 is controlled so as to satisfy the following two conditions that have been obtained automatically.

The first of the two conditions is that the tensile stress σTC applied to the band-shaped metal member 12 by the moving roller 70 on the outer peripheral side of the neutral surface N of the band-shaped metal member 12, the fixed roller 42, and the moving port The sum of the bending stress σbA applied to the band-shaped metal member 12 by the roller 44 and the residual stress σrA applied to the band-shaped metal member 12 in the circumferential length adjusting step P8 is smaller than the yield stress σy0 of the band-shaped metal member 12. To make it as large as possible in the range. The second of the above two conditions is that, on the outer peripheral side of the neutral surface N of the band-shaped metal member 12, the tensile stress σTC applied to the band-shaped metal member 12 by the moving roller 70 and the band-shaped metal by the moving roller 70. The sum of the bending stress σbC applied to the member 12 and the residual stress σrA applied to the band-shaped metal member 12 in the circumferential length adjusting step P8 is as small as possible within a range smaller than the yield stress σy0 of the band-shaped metal member 12. To make it bigger. The tensile stress σTC, bending stress σbC, and bending stress σbA are expressed by the following equations (2) to (4). In Formula (2), T2 is the tension in the circumferential direction of the band-shaped metal member 12, and is calculated based on, for example, the second load F2 and the moving amount of the moving roller 70 from a predetermined relationship. FIG. 6 is a cross-sectional area immediately before the end of the circumferential length adjusting step P8 of the belt-shaped metal member 12. FIG. In Expression (3), rC is the radius of the moving roller 70. In Expression (4), rA is the radius of the moving port 44, and the radius rB of the fixed roller 42 is the same. .
σTC = T2 / A1 (2)
σbC = E * (t / 2) / (rC + (t / 2)) (3)
σbA = E * (t / 2) / (rA + (t / 2)) (4)

  Returning to FIG. 8, in the residual stress applying step P <b> 9, the residual stress applying device 66 configured as described above is used, and the deflection between the fixed roller 42 and the moving roller 44 is completed even after the peripheral length adjusting step P <b> 8 is completed. It is wound in the state without. Then, when the moving roller 44 is driven to rotate by an electric motor (not shown), the band-shaped metal member 12 is rotated in the circumferential direction as indicated by an arrow f. In this state, as indicated by an arrow d, the moving roller 70 is moved in the direction of pressing the outer peripheral surface 24 of the band-shaped metal member 12 toward the inner peripheral surface 22 with the force of the second load F2, thereby moving the moving roller. 70 gives a predetermined stress to the band-shaped metal member 12 so that only the inner peripheral side of the neutral surface N (see FIG. 10) of the band-shaped metal member 12 is plastically deformed.

  FIG. 10 is a diagram showing a distribution in the thickness direction of the total stress σ2 obtained by adding a plurality of stresses applied to the band-shaped metal member 12 in the residual stress applying step P9 of FIG. In the residual stress applying step P9, the band-shaped metal member 12 has a tensile stress σTC by the moving roller 70 shown by a one-dot chain line in FIG. 10 and a bending stress σbC by the moving roller 70 shown by a two-dot chain line in FIG. Is granted. Further, what is indicated by a long broken line is the residual stress σrA applied to the band-shaped metal member 12 in the circumferential length adjusting step P8. Here, the yield stress of the band-shaped metal member 12 during the execution of the residual stress applying process P9 is increased from the yield stress σy0 to the yield stress σy1 as indicated by an arrow g in FIG. 11 due to work hardening in the previous process.

  In FIG. 10, the yield region S2 in which the total stress σ2 exceeds the yield stress σy1 of the strip-shaped metal member 12 is a region where strain remains even if the total stress σ2 is removed. In the residual stress applying step P9, the band-shaped metal member 12 is plastically deformed in the circumferential direction so that a part of the inner peripheral side from the neutral surface N is directed toward the inner peripheral side, and the outer peripheral side is elastically deformed from the part. It is said.

Returning to FIG. 4, after the residual stress applying step P9, P10 is a replacement processing step. After the residual stress applying step P9 is finished, the belt-like metal member 12 is applied with a certain tension T3, The metal member 12 is replaced from the fixed roller 42 and the moving roller 44 to the replacement rollers 92 and 94. FIG. 12 shows a replacement processing device 90 used in the replacement processing step P10. FIG. 12A is a diagram conceptually showing an initial state of the replacement process, and FIG. 12B is a diagram conceptually showing an end state of the replacement process. In the following description, description will be made using the XY directions shown in FIG.
In FIG. 12A, after the residual stress applying step P9 is completed, the replacement rollers 92 and 94 having a semi-cylindrical shape are disposed between the belt-like metal members 12 supported between the fixed roller 42 and the moving roller 44. Inserted. Thereafter, the replacement roller 92 is moved in the X direction, and the replacement roller 94 is moved in the -X direction. In conjunction with the movement of the replacement rollers 92 and 94, the fixed roller 42 moves in the -Y direction and the moving roller 44 moves in the Y direction so that the tension T3 applied to the band-shaped metal member 12 is constant. In the final state shown in FIG. 12B, the replacement from the fixed roller 42 and the moving roller 44 to the replacement rollers 92 and 94 is completed.

At this time, the radius rD of the replacement rollers 92 and 94 is configured to be larger than the radius rB of the fixed roller 42 and the radius rA of the moving roller 44. The bending stress generated in the replacement rollers 92 and 94 is expressed by Expression (5).
σbD = E * (t / 2) / (rD + (t / 2)) (5)
Therefore, the bending stress σbD generated in the replacement rollers 92 and 94 is smaller than the bending stress σbA generated in the fixed roller 42 and the moving roller 44.

  That is, when the replacement from the fixed roller 42 and the moving roller 44 to the replacement rollers 92 and 94 is completed, as shown in FIG. 13A, the band-shaped metal member 12 has a tensile stress σTD due to the tension T3. A bending stress σbD applied to the band-shaped metal member 12 is generated by the replacement rollers 92 and 94. Further, as will be described later, residual stress as shown in FIG. 16 is generated by the peripheral length adjusting step P8 and the residual stress applying step P9, as will be described later. A total stress σ3 as shown in FIG. 13B is generated in the replacement rollers 92 and 94 of the band-shaped metal member 12.

  Here, when the application of the tension T3 is canceled after the replacement to the replacement rollers 92 and 94 is completed, the tensile stress σTD generated by the tension T3 disappears. The total stress σ3 generated in the 94 portion is as shown in FIG. At this time, since the total stress σ3 does not exceed the yield stress σy1 of the band-shaped metal member 12 on the inner peripheral side of the band-shaped metal member 12, there is no roller strain remaining on the band-shaped metal member 12 as in the prior art. The durability of the band-shaped metal member 12 is remarkably improved.

FIG. 14 is a diagram specifically showing the replacement processing device 90.
The moving roller 44 is movable in the Y direction, the −Y direction, the X direction, and the −X direction by the servo motor 442 while being guided by the linear guide 441. The moving roller 44 is rotated by a servo motor 443. The fixed roller 42 is movable in the −Y direction and the Y direction by a servo motor (not shown) while being guided by a linear guide (not shown). The replacement roller 92 is movable in the X direction and the −X direction by the servo motor 922 while being guided by the linear guide 921. The replacement roller 94 is movable in the −Y direction and the Y direction by the servo motor 942 while being guided by the linear guide 941. Further, the replacement rollers 92 and 94 are supported so as to be movable in the front-rear direction in FIG. 14 (perpendicular to the paper surface in FIG. 14), so that the fixed roller 42 and the moving port 44 can be moved from the standby position. It is possible to enter between the band-shaped metal members 12 supported by the metal.
Each servo motor 442, 922, 942 is controlled by control means (not shown) so that the tension σT applied to the band-shaped metal member 12 is constant based on a signal from a load cell provided on the band-shaped metal member 12, for example. The

  After the replacement to the replacement rollers 92 and 94 is completed, the strip-shaped metal member 12 is deformed to return the strain to the original state when the load is removed and the free state is set. Strain remains in a part of the inner periphery. During the deformation, the inner peripheral portion of the band-shaped metal member 12 is compressed in the circumferential direction toward the inner peripheral side where the residual strain is larger. FIG. 15 shows the distribution in the thickness direction of the residual stress, ie, residual stress σrC, resulting from the stress excluding the residual stress σrA among the residual stress, ie, residual stress σr, in the strip-shaped metal member 12 in the free state. FIG. As shown in FIG. 15, a compressive residual stress is applied to the inner peripheral portion of the strip-shaped metal member 12 toward the inner peripheral side. FIG. 16 is a diagram showing the distribution in the thickness direction of the residual stress σr remaining on the band-shaped metal member 12 in the free state. As shown in FIG. 16, the compressive residual stress remains on the inner peripheral portion and the outer peripheral portion of the band-shaped metal member 12 toward the inner peripheral side and the outer peripheral side, respectively, and the tensile residual stress remains in the central portion. . In particular, when the residual stress is applied to the inner peripheral portion of the band-shaped metal member 12 by the residual stress applying step P9, the replacement processing step P10 is effective.

  Returning to FIG. 4, the aging treatment is performed on the band-shaped metal member 12 in the aging treatment step P11 after the replacement treatment step P10. In the present embodiment, as the aging treatment, the strip metal member 12 is tempered by heating the strip metal member 12 to a predetermined temperature and holding it for a sufficient time before cooling.

Next, in the nitriding process P12, the band-shaped metal member 12 is subjected to nitriding. In this embodiment, as the nitriding treatment, nitrogen is applied to the surface layer of the band-shaped metal member 12 by heating the band-shaped metal member 12 and holding it in an atmosphere containing a nitriding gas having a predetermined concentration, for example, ammonia decomposition gas, for a predetermined time. Is diffused. FIG. 17 is a diagram showing a distribution in the thickness direction of the residual stress σrN applied to the band-shaped metal member 12 by the nitriding treatment. As shown in FIG. 17, by the nitriding treatment, a large compressive residual stress is left in the inner peripheral portion and the outer peripheral portion of the band-shaped metal member 12 toward the inner peripheral side and the outer peripheral side, respectively. A tensile residual stress is left. Then, the residual stress σrN shown in FIG. 17 is applied in addition to the residual stress σr applied up to the previous step, so that the distribution of the residual stress in the band-shaped metal member 12 in the thickness direction is as shown in FIG. Distribution.

  Next, in the stacking step P13, a plurality of strip-shaped metal members 12 having different peripheral lengths are stacked in close contact with each other so that the peripheral lengths increase in order from the inner peripheral side toward the outer peripheral side, thereby forming the stacked ring 14. Is done.

  According to the manufacturing method of the laminated ring 14 of the present embodiment, the band-shaped metal member 12 wound around the fixed roller 42 and the moving roller 44 is rotated in the circumferential direction while applying tension by the moving roller 70, and the band-shaped metal member The belt-shaped metal member 12 is moved by the movable port 70 by locally pressing the outer circumferential surface 24 of the band-shaped metal member 12 toward the inner circumferential side by using the movable port layer 70 provided on the outer circumferential side of the belt 12. Since the residual stress applying step P9 for applying the compressive residual stress σrC to the inner peripheral portion of the belt-shaped metal member 12 is included, the inner peripheral surface 22 of the band-shaped metal member 12 is locally pressed toward the outer peripheral side in the peripheral length adjusting step P8. Even if the tensile residual stress σrAl remains in the inner peripheral portion of the band-shaped metal member 12, the compressive residual stress σrC is applied to the inner peripheral portion of the band-shaped metal member 12 in the residual stress applying step P9. When the metal member 12 is used as a component of the laminated ring 14 of the transmission belt 10, the strength margin of the inner peripheral portion of the belt-like metal member 12 is increased (large) with respect to the residual stress required on the compression side at the minimum. Therefore, durability of the strip-shaped metal member 12 can be improved.

  Moreover, according to the manufacturing method of the laminated ring 14 of a present Example, after the residual stress provision process P9 is complete | finished, in the state to which the fixed tension | tensile_strength was provided to the said strip-shaped metal member 12, the strip-shaped metal member 12 and the fixed roller 42 and Since the replacement from the moving roller 44 to the replacement rollers 92 and 94 is performed, the bending stress σbD generated in the replacement rollers 92 and 94 is smaller than the bending stress σbA generated in the fixed roller 42 and the moving roller 44 and remains. The stress σrC does not exceed the yield stress −σy1 of the band-shaped metal member 12 on the inner peripheral surface side. Therefore, the band-shaped metal member is plastically deformed at the fixed roller 42 and moving roller 44 portions as in the conventional case, and the band-shaped metal member. There is no risk of lowering the durability.

  Moreover, according to the manufacturing apparatus of the laminated ring 14 of a present Example, since a comparatively small diameter roller can be used for the fixed roller 42 and the moving roller 44, the neutral surface N of the strip | belt-shaped metal member 12 (refer FIG. 10). Only the outer peripheral side can be plastically deformed, and the durability of the strip-shaped metal member 12 is improved.

As mentioned above, although one Example of this invention was described in detail with reference to drawings, this invention is not limited to this Example, It can implement in another aspect.

For example, the band-shaped metal member 12 may be formed from a steel material other than maraging steel and stainless steel.

  In addition, the mechanical configurations of the residual stress applying device 66 and the replacement processing device 90 are disclosed as examples, and can be realized even with other known mechanical configurations. For example, as the electric actuator used for moving the fixed roller 42, the moving roller 44, and the replacement rollers 92 and 94, other types of actuators such as a hydraulic type or a pneumatic type may be used instead.

FIG. 18 discloses another embodiment of the processing apparatus that can be used for the peripheral length adjusting step P8, the residual stress applying step P9, and the reassigning processing step P10. Here, only the function as the replacement processing device 900 used in the replacement processing step P10 will be described in detail. In addition, in the description, the same code | symbol is attached | subjected and demonstrated to what has the same effect.
That is, the replacement processing apparatus 900 includes a first roller 910 including a small diameter portion 911, a large diameter portion 912, and a guide portion 913 that spirally guides from the small diameter portion 911 toward the large diameter portion 912, and the first roller. A second roller that is rotatable about a rotation axis parallel to the rotation axis of 910 and includes a small diameter portion 921, a large diameter portion 922, and a guide portion 923 that spirally guides from the small diameter portion 921 toward the large diameter portion 922. 920, and the band-shaped metal member 12 wound between the small-diameter portion 911 of the first roller 910 and the small-diameter portion 921 of the second roller 920 has a large diameter from the small-diameter portions 911 and 921 through the guide portions 913 and 923. It is comprised from the guidance device 930 which guides to the part 912,922 side.

  The first roller 910 is provided so as to be able to approach and separate from the second roller 920. Therefore, when the first roller 910 is moved leftward in FIG. A tension T4 can be applied to the band-shaped metal member 12 wound between the second roller 920 and the second roller 920. The first roller 910 is driven to rotate by a motor (not shown). The guide device 930 includes two rollers 931 positioned with the band-shaped metal member 12 interposed therebetween, and a frame 932 that supports the two rollers 931, respectively, along the rotation axis of the first roller 910. Can be moved.

In the replacement processing device 900 configured as described above, the small diameter portion of the first roller 910 is in a state where the belt-like metal member 12 is applied with a constant tension T4 at the time when the residual stress applying step P9 is completed. 911 and a small diameter portion 921 of the second roller 920 are wound. When the guide device 930 is moved downward in FIG. 18 while rotating the first roller 910 in this state, the band-shaped metal member 12 is guided by the guide portions 912 and 923 and the large size of the first roller 910 is reached. It moves to the diameter part 912 and the large diameter part 922 of the 2nd roller 920, and a replacement process is completed.
At this time, the first roller 910 is gradually moved toward the second roller 920 so that the tension T4 of the band-shaped metal member 12 becomes constant. Such control can be controlled based on a signal from a load cell provided in the belt-shaped metal member 12.

  When the band-shaped metal member 12 is wound between the large-diameter portion 912 of the first roller 910 and the large-diameter portion 922 of the second roller 920, the replacement process is completed, and the first roller 910 is moved in this state. When the second roller 920 is further approached, the tension T4 applied to the band-shaped metal member 12 is released, and the next aging treatment process P11 can be entered.

  As described above, the replacement processing device 900 according to the present embodiment can perform the replacement processing with a relatively simple configuration as compared with the replacement processing device 90 described above.

It should be noted that the above description is merely an embodiment, and other examples are not illustrated. However, the present invention is implemented in variously modified and improved modes based on the knowledge of those skilled in the art without departing from the gist of the present invention. Can do.

DESCRIPTION OF SYMBOLS 10 ... Transmission belt 12 ... Strip | belt-shaped metal member 66 ... Residual stress imparting apparatus 42 ... Fixed roller 44 ... Moving roller 70 ... Moving roller 90 ... Replacement processing apparatus 92, 94 ... Replacement rollers

Claims (3)

A method for producing a thin plate-like endless metal ring,
An adjusting step of adjusting the peripheral length of the metal ring by a peripheral length adjusting roller disposed on the inner peripheral side of the metal ring;
An applying step of applying residual stress to the metal ring by an outer roller disposed on the outer peripheral side of the metal ring;
In a state in which a constant tension is applied in the circumferential direction of the metal ring, a replacement step of replacing with a large-diameter roller having a diameter larger than the diameter of the circumferential length adjusting roller;
A method for producing a thin plate-like endless metal ring. In the manufacturing method of the sheet-like endless metal ring according to claim 1,
The circumferential length adjusting roller is composed of two rollers arranged at intervals, and the large-diameter roller is disposed on the inner circumferential side of the metal ring between the two circumferential length adjusting rollers. A method for producing a thin plate-like endless metal ring. In the manufacturing method of the sheet-like endless metal ring according to claim 1,
The large-diameter roller has a large-diameter portion, a small-diameter portion having a smaller diameter, and a spiral guide portion whose diameter gradually increases from the small-diameter portion toward the large-diameter portion. Method for manufacturing an endless metal ring.

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