JP5494025B2 - Manufacturing method of laminated ring - Google Patents

Description

  The present invention relates to a method for manufacturing a laminated ring used for a transmission belt of a belt type continuously variable transmission for a vehicle, and more particularly to a technique for increasing the durability of a band-shaped metal member constituting the laminated ring.

  A multi-layer ring used for a transmission belt of a vehicular belt type continuously variable transmission for supporting a plurality of elements connected in a ring is known. Yes. This laminated ring is manufactured as follows, for example. First, a steel plate such as maraging steel or stainless steel is welded at both ends to form a cylindrical member. Next, the cylindrical member is divided at a predetermined interval in the axial direction to form a plurality of short cylindrical members. Next, by adjusting the circumference while the plurality of short cylindrical members are stretched in the circumferential direction, a plurality of endless annular band-like metal members having different circumferences are obtained. Next, the plurality of strip-shaped metal members are subjected to a surface treatment such as nitriding treatment or shot peening and an aging treatment, thereby improving their hardness and fatigue strength, for example. And a lamination | stacking ring is formed by laminating | stacking these several strip | belt-shaped metal members in a mutually close contact state. As a manufacturing method of such a laminated ring, for example, a manufacturing method described in Patent Document 1 is known.

  Patent Document 1 describes a circumference correction device used for adjusting the circumference. This circumferential length correcting device is configured to press the belt-shaped metal member by locally pressing a part of the belt-shaped metal member wound around the driving roller and the driven roller from the inner circumferential side toward the outer circumferential side. And a straightening roller extending in the circumferential direction. By using this circumference correction device, the belt-like metal member is given an arc shape that is convex on the outer circumference side in the cross section in the width direction. The strip-shaped metal member is provided with the arc shape described above, so that when the plurality of the strip-shaped metal members are stacked, the stacked state can be easily maintained.

JP 2009-22991 A

  However, in the conventional method for manufacturing a laminated ring, a tensile residual stress is applied to the inner peripheral portion of the band-shaped metal member by locally pressing the inner peripheral surface of the band-shaped metal member toward the outer peripheral side. For this reason, there is a problem that the strength of the inner peripheral portion is less than the required strength and the durability is lowered. On the other hand, conventionally, it has been dealt with by increasing the number of strip-shaped metal members used in one laminated ring, but according to this, the number of parts of the laminated ring increases and the manufacturing cost increases. There was a drawback that the weight of the laminated ring was increased.

  The present invention has been made against the background described above, and an object of the present invention is to provide a method for manufacturing a laminated ring capable of enhancing the durability of a strip-shaped metal member.

To achieve this object, the gist of the invention according to claim 1 is that: (a) a plurality of endless annular belt-like metal members are stacked in close contact, and support a plurality of elements connected in an annular shape; A manufacturing method of a laminated ring used for a transmission belt of a belt type continuously variable transmission for a vehicle, comprising: (b) using at least two first rotating rollers around which the belt-shaped metal member is wound. A circumferential length adjusting step of extending the circumferential length of the band-shaped metal member by relatively separating the at least two first rotating rollers while rotating the metal member in the circumferential direction; and (c) the band-shaped metal member is While rotating the band-shaped metal member in the circumferential direction using at least two wound second rotating rollers, the band-shaped metal member is rotated using a third rotating roller provided on the outer peripheral side of the band-shaped metal member. By bending the belt-shaped metal member along the outer circumferential surface of the third rotating roller by locally presses the peripheral surface to the inner peripheral side, the residual stress of imparting compressive residual stress on the inner peripheral portion of the belt-shaped metal member and applying step, seen including, (d) the residual stress imparting step is only the inner peripheral side from the neutral plane of the belt-shaped metal member to be plastically deformed.

Further, the gist of the invention according to claim 2 is that, in the invention according to claim 1 , the residual stress applying step is performed by the third rotating roller on the outer peripheral side of the neutral surface of the band-shaped metal member. The sum of the tensile stress applied to the strip metal member, the bending stress applied to the strip metal member by the second rotating roller, and the residual stress applied to the strip metal member in the circumference adjustment step is: The purpose is to locally press the outer peripheral surface of the band-shaped metal member toward the inner peripheral side so as to be smaller than the yield stress of the band-shaped metal member.

Further, the gist of the invention according to claim 3 is that, in the invention according to claim 1 or 2 , in the residual stress applying step, the third rotation is performed on the outer peripheral side of the neutral surface of the band-shaped metal member. The sum of the tensile stress applied to the band-shaped metal member by the roller, the bending stress applied to the band-shaped metal member by the third rotating roller, and the residual stress applied to the band-shaped metal member in the circumferential length adjusting step. Then, the outer peripheral surface of the band-shaped metal member is locally pressed toward the inner peripheral side so as to be smaller than the yield stress of the band-shaped metal member.

The gist of the invention according to claim 4 is that, in the invention according to any one of claims 1 to 3 , the residual stress applying step includes: (a) the strip metal immediately before the end of the circumference adjusting step; Based on the circumferential tension and cross-sectional area of the member, the yield stress at the end of the circumferential length adjustment process of the band-shaped metal member is calculated. (B) On the neutral surface of the band-shaped metal member, the third rotating roller So that the sum of the tensile stress applied to the band-shaped metal member by the above and the residual stress applied to the band-shaped metal member in the circumference adjustment step is equal to the yield stress at the end of the circumference adjustment step. There exists in pressing locally the outer peripheral surface of a strip | belt-shaped metal member toward an inner peripheral side.

A gist of the invention according to claim 5 is that, in the invention according to any one of claims 1 to 4 , (a) the band-shaped metal member is made of steel, and (b) the residue. Before the stress applying step, there is a residual stress removing step of removing the residual stress by heating the band-shaped metal member to the _AC1 transformation point or higher.

According to the manufacturing method of the laminated ring of the invention according to claim 1, the at least two first rotating rollers around which the band-shaped metal member is wound are used to rotate the band-shaped metal member in the circumferential direction, and A circumferential length adjusting step for extending the circumferential length of the band-shaped metal member by relatively separating the first rotation roller, and the band-shaped metal member using at least two second rotation rollers around which the band-shaped metal member is wound. The belt-shaped metal member is pressed by locally pressing the outer circumferential surface of the band-shaped metal member toward the inner circumferential side using a third rotating roller provided on the outer circumferential side of the belt-shaped metal member. third by bending along the outer circumferential surface of the rotating roller, since it contains a residual stress applying step of applying the compressive residual stress on the inner peripheral portion of the belt-shaped metal member, the metal band member in the circumferential length adjusting step Even if tensile residual stress is applied to the inner peripheral portion of the band-shaped metal member by locally pressing the inner peripheral surface toward the outer peripheral side, compression residual is applied to the inner peripheral portion of the band-shaped metal member in the residual stress applying step. Since the stress is applied, the strength of the inner peripheral portion has a large margin with respect to the required strength, so that the durability of the band-shaped metal member can be enhanced. Further, since the residual stress applying step plastically deforms only the inner peripheral side from the neutral surface of the band-shaped metal member, the plastic deformation region (yield region) of the band-shaped metal member in the residual stress applying step is one in the thickness direction. Since the circumferential length of the band-shaped metal member is not changed, the compressive residual stress is applied to the inner circumferential portion of the band-shaped metal member without changing the circumferential length of the band-shaped metal member adjusted in the circumferential length adjusting step. be able to.

Moreover, according to the manufacturing method of the lamination | stacking ring of the invention concerning Claim 2 , the said residual stress provision process is the tension | tensile_strength added to a strip | belt-shaped metal member by a 3rd rotating roller in the outer peripheral side rather than the neutral surface of a strip | belt-shaped metal member. The sum of the stress, the bending stress applied to the band-shaped metal member by the second rotating roller, and the residual stress applied to the band-shaped metal member in the circumference adjusting step is smaller than the yield stress of the band-shaped metal member. Thus, since the outer peripheral surface of the band-shaped metal member is locally pressed toward the inner peripheral side, the plastic deformation region (yield region) of the band-shaped metal member in the residual stress application step becomes a part in the thickness direction. The circumferential length of the band-shaped metal member is not changed, so that the compressive residual stress can be applied to the inner circumferential portion of the band-shaped metal member without changing the circumferential length of the band-shaped metal member adjusted in the circumferential length adjusting step. That.

Moreover, according to the manufacturing method of the lamination | stacking ring of invention concerning Claim 3 , the said residual stress provision process is the tension | tensile_strength added to a strip | belt-shaped metal member by a 3rd rotating roller in the outer peripheral side rather than the neutral surface of a strip | belt-shaped metal member. The outer peripheral surface of the band-shaped metal member is set so that the sum of the stress and bending stress and the residual stress applied to the band-shaped metal member in the circumference adjusting step is smaller than the yield stress of the band-shaped metal member. Since the band-shaped metal member is pressed locally toward the peripheral side, the band-shaped metal member is not plastically deformed by the second rotating roller, and a part of the thickness direction is plastically deformed only by the third rotating roller. It is possible to prevent the residual stress distribution from varying in the circumferential direction.

Moreover, according to the manufacturing method of the laminated ring of the invention concerning Claim 4 , the said residual stress provision process is the strip | belt shape based on the tension | tensile_strength of the circumferential direction and cross-sectional area of the strip | belt-shaped metal member just before completion | finish of the said circumference adjustment process. The yield stress at the end of the circumference adjustment process of the metal member is calculated, the tensile stress applied to the band metal member by the third rotating roller on the neutral surface of the band metal member, and the band metal in the circumference adjustment process Since the sum of the residual stress applied to the member is equal to the yield stress at the end of the circumference adjustment step, the outer peripheral surface of the band-shaped metal member is locally pressed toward the inner peripheral side, Even if the yield stress of the band-shaped metal member increases due to work hardening caused by stretching the band-shaped metal member in the circumferential direction in the circumferential length adjusting process, the residual stress is applied based on the increased yield stress. Stress applied to the genus member can be adjusted. Therefore, in the residual stress applying step, compressive residual stress can be applied to the widest possible region of the inner peripheral portion of the band-shaped metal member within a range in which the circumference of the band-shaped metal member is not changed.

Moreover, according to the manufacturing method of the lamination | stacking ring of the invention concerning Claim 5 , a strip | belt-shaped metal member consists of steel, and before the said residual stress provision process, the said strip | belt-shaped metal member is more than _AC1 transformation point. Since it includes a residual stress removing step of removing residual stress by heating, it is applied to the band metal member in the residual stress applying step by removing the residual stress applied to the band metal member before the residual stress applying step. The accuracy of residual stress can be improved.

  In this specification, the neutral surface is a surface in which no bending stress is generated inside the band-shaped metal member when the band-shaped metal member is bent in a direction perpendicular to the outer peripheral surface. is there.

  Here, preferably, in the band-shaped metal member, a ratio of a distance from the outer peripheral surface to the acting position of the maximum tensile residual stress with respect to a distance from the outer peripheral surface to the neutral surface is 40% or more and Residual stress is applied such that the ratio of the distance from the inner peripheral surface to the position where the maximum tensile residual stress is applied to the distance from the surface to the neutral surface is 40% or more. Residual stress required when the band-shaped metal member is used as a component part of the transmission belt becomes the compression side as it goes from the neutral surface to the outer peripheral side and the inner peripheral side. If it does as mentioned above, since the residual stress of the outer peripheral part and inner peripheral part of a strip | belt-shaped metal member becomes a compression side suitably, the intensity | strength of a strip | belt-shaped metal member can be raised suitably.

It is a perspective view which shows a part of the circumferential direction of the transmission belt of the belt type continuously variable transmission for vehicles which concerns on this invention. It is sectional drawing which shows it with the cross section of the width direction about one strip | belt-shaped metal member of the some strip | belt-shaped metal members which comprise the lamination | stacking ring of FIG. It is a figure which shows distribution of the thickness direction of a residual stress when the strip | belt-shaped metal member of FIG. 1 is a free state. It is process drawing for demonstrating the manufacturing process of the lamination | stacking ring shown in FIG. It is a figure which shows notionally the circumference adjustment apparatus used in the circumference adjustment process of FIG. It is sectional drawing which shows the VI-VI arrow part cross section of the circumference adjusting device of FIG. FIG. 5 is a diagram showing the relationship between the circumferential tension acting on the belt-shaped metal member, the displacement of the moving roller, and the elapsed time in the circumferential length adjusting step of FIG. 4. It is a figure which shows distribution of the thickness direction of the total stress just before completion | finish of the circumference adjustment process of the strip | belt-shaped metal member of FIG. It is a figure which shows the distribution of the thickness direction of the stress which remains in the strip | belt-shaped metal member made into the free state, ie, a residual stress. It is a figure which shows notionally the residual stress provision apparatus used at the residual stress provision process of FIG. It is sectional drawing which shows the XI-XI arrow part cross section of the residual stress provision apparatus of 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 yield stress of a strip | belt-shaped metal member increasing by work hardening after the residual stress provision process of FIG. Of the residual stress remaining in the band-shaped metal member in the free state in the residual stress applying step in FIG. 4, the residual stress distribution in the thickness direction due to the stress excluding the residual stress remaining in the circumferential length adjusting step 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 in 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 a figure which shows distribution of the thickness direction of the residual stress of the strip | belt-shaped metal member in the other Example of this invention. It is a figure which shows notionally the circumference adjustment apparatus used at a circumference adjustment process among the manufacturing processes of the strip | belt-shaped metal member of the other Example of this invention shown in FIG. It is sectional drawing which shows the XIX-XIX arrow part cross section of the circumference adjusting device of 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 a residual stress provision process among the manufacturing processes of the strip | belt-shaped metal member of the other Example of this invention shown in FIG. In the residual stress imparting step of the band metal member manufacturing process of another embodiment of the present invention shown in FIG. 4, the residual stress remaining in the circumferential length adjusting step among the residual stress remaining in the band metal member in a free state It is a figure which shows distribution of the thickness direction of the residual stress which originates in the stress remove | excluding. It is process drawing for demonstrating the manufacturing process of the lamination | stacking ring of the other Example of this invention. It is a figure which shows notionally the residual stress provision apparatus used in a residual stress provision process among the manufacturing processes of the strip | belt-shaped metal member of the other Example of this invention shown in FIG. It is sectional drawing which shows the XXIV-XXIV arrow part cross section of the residual stress provision apparatus of FIG. It is sectional drawing which shows the XXV-XXV arrow part cross section of the residual stress provision apparatus of FIG. When the conventional strip | belt-shaped metal member is a free state, it is a figure which shows distribution of the thickness direction of the residual stress of the strip | belt-shaped metal member.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  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 according to the present invention. In FIG. 1, a transmission belt 10 includes a pair of laminated rings 14 each of which is formed by laminating a plurality of endless annular belt-like metal members 12 in close contact with each other, and along the laminated rings 14. And a plurality of elements 18 each made of a plate-like metal connected in a ring shape in the thickness direction. A pair of ring holding grooves 20 drilled toward the center in the width direction are formed on both side surfaces of the element 18 in the width direction. In order to support the plurality of elements 18, the pair of laminated rings 14 are inserted into one and the other of a pair of ring holding grooves 20 formed in the plurality of elements 18, respectively. The laminated ring 14 is formed by, for example, laminating six strip-shaped metal members 12 whose circumferential lengths are adjusted in order 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 composed of the six strip-shaped metal members 12 is not necessarily shown in six layers as described above.

  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 which forms convex shape on the outer peripheral side. 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 in the outer peripheral portion and the inner peripheral portion in the thickness direction of the band-shaped metal member 12. 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.

  Further, the band-shaped metal member 12 has a thickness direction distance from the inner peripheral surface 22 to the position of the maximum tensile residual stress with respect to a distance A in the thickness direction from the inner peripheral surface 22 to the neutral surface N indicated by a one-dot chain line. Residual stress is applied so that the ratio of the distance B is about 75%. The neutral surface N is located at a distance of half the thickness t from the outer peripheral surface 24 in the thickness direction. Further, in the band-shaped metal member 12, the ratio of the distance D in the thickness direction from the outer peripheral surface 24 to the position where the maximum tensile residual stress is applied to the distance C in the thickness direction from the outer peripheral surface 24 to the neutral surface N is about Residual stress is applied so as to be 100%.

  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 at the time of welding in the welding step P2, the first cylindrical member 34 is subjected to the first solution. 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 40 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 roller 44 provided so as to be able to approach and separate. The outer peripheral surfaces of the fixed roller 42 and the moving roller 44 are each formed in a circular arc shape having a convex shape on the outer peripheral side in a cross section passing through the shaft centers C1 and C2. The fixed roller 42 and the moving roller 44 correspond to the first rotating roller in the present invention.

  FIG. 6 is a cross-sectional view showing a cross section taken along the line VI-VI of the circumferential length adjusting device 40 of FIG. As shown in FIG. 6, the peripheral length adjusting device 40 is fixed to the hydraulic actuator 50 fixed to the support wall 48 and the tip of the output rod 52 of the hydraulic actuator 50, and the rotation shaft 54 of the moving roller 44. A support member 56 that rotatably supports both end portions of the moving roller 44, and an electric motor 58 that rotationally drives the rotating shaft 54 of the moving roller 44. When the hydraulic pressure is supplied to the first hydraulic chamber 62, the hydraulic actuator 50 causes the output rod 52 and the moving roller 44 connected thereto to approach the fixed roller 42 indicated by the arrow a in FIGS. When the hydraulic pressure is supplied to the second hydraulic chamber 64, the output rod 52 and the moving roller 44 connected thereto are separated from the fixed roller 42 indicated by the arrow b in FIGS. It moves in the direction.

  Returning to FIG. 5, in the circumferential length adjusting step P <b> 8, the circumferential length adjusting device 40 configured as described above is used, and the band-shaped metal member 12 is wound around the fixed roller 42 and the moving roller 44 without slack. As the moving roller 44 is rotated by the electric motor 58, the belt-like metal member 12 is rotated in the circumferential direction as indicated by an arrow c, and the moving roller 44 is separated from the fixed roller 42 as indicated by an arrow b. By doing so, the band-shaped metal member 12 is stretched in the circumferential direction. In this embodiment, based on a relationship obtained experimentally in advance, the circumference of the band-shaped metal member 12 is determined in advance based on the displacement Y from the original position of the moving roller 44 indicated by a two-dotted 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. 7 is a diagram showing the relationship between the circumferential tension T acting on the band-shaped metal member 12 and the displacement Y of the moving roller 44 and the elapsed time s in the circumferential length adjusting step P8 of FIG. As shown in FIG. 7, the displacement Y is increased at a constant rate from the start of movement of the moving roller 44 to time s1, and is held at a predetermined value from the time s1 to the end time s2 of the circumferential length adjusting step P8. On the other hand, the tension T rapidly increases from zero to a value exceeding the predetermined tension T1 from the start of movement to the time s1, and then gradually decreases toward the predetermined tension T1, and from the time s1. The predetermined tension T1 is maintained until time s2.

Figure 8 is a diagram showing the circumferential length distribution in the thickness direction of the adjustment process P8 immediately before the end of the tensile stress sigma _TA and bending total stress obtained by adding the stress sigma _bA .sigma.1 of the belt-shaped metal member 12. Immediately before the end of the circumferential length adjusting step P8, the belt-like metal member 12 is subjected to the tensile stress σ _TA by the moving roller 44 shown by a one-dot chain line in FIG. 8 and by the moving roller 44 shown by a two-dot chain line in FIG. Bending stress σ _bA is applied. The tensile stress σ _TA and the bending stress σ _bA are expressed by the following formulas (1) and (2). In Formula (1), A1 is a cross-sectional area immediately before the end of the circumferential length adjusting step P8 of the belt-shaped metal member 12. In Equation (2), 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 <b> 8 of the band-shaped metal member 12, and r _A is the radius of the moving roller 44.
σ _TA = T1 / A1 (1)
σ _bA = E * (t / 2) / (r _A + (t / 2)) (2)

In FIG. 8, the yield region S1 in which the total stress σ1 exceeds the yield stress σ _y0 of the strip-shaped metal member 12 is a region where strain remains even if the total stress σ1 is removed. The yield stress σ _y0 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 tension T1 is removed from the state as described above and the belt-shaped metal member 12 is brought into a free state, the band-shaped metal member 12 is deformed so as to return the strain to the original state, but the strain remains on the outer peripheral side from 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. 9 is a diagram showing a distribution in the thickness direction of the stress remaining in the band-shaped metal member 12 in the free state, that is, the residual stress _σrA . As shown in FIG. 9, a large compressive residual stress remains on the outer peripheral portion of the belt-shaped metal member 12 toward the outer peripheral side, and a predetermined tensile residual stress _σrA1 remains on the inner peripheral portion. The predetermined tensile residual stress σ _rA1 is a value _represented by the following formula (3).
σ _rA1 = σ _bA / 4 (1)

  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. 10 is a diagram conceptually showing the residual stress applying device 66 used in the residual stress applying step P9. In FIG. 10, the residual stress applying device 66 includes a pair of position-fixing fixed rollers 68 that are rotatably provided around the shaft centers C3 and C4, and rotations about the shaft center C5 parallel to the shaft centers C3 and C4, respectively. The belt-shaped metal member 12 wound around the pair of fixed rollers 68 is provided in such a manner that the outer peripheral surface 24 of the band-shaped metal member 12 is locally pressed toward the inner peripheral side, and is separated from the band-shaped metal member 12 opposite thereto. And a moving roller 70 provided to be movable in each direction. An electric motor (not shown) for rotating the fixed roller 68 is connected to one end of the fixed roller 68. The fixed roller 68 corresponds to the second rotating roller in the present invention, and the moving roller 70 corresponds to the third rotating roller in the present invention.

FIG. 11 is a cross-sectional view showing a cross-section of the residual stress applying device 66 in FIG. As shown in FIG. 11, the residual stress applying device 66 is fixed to the hydraulic actuator 74 fixed to the support wall 72 and the tip of the output rod 76 of the hydraulic actuator 74, and the rotation shaft 78 of the moving roller 70. The second load F2 acting on the band-shaped metal member 12 from the moving roller 70 by measuring the axial force acting on the support member 80 that rotatably supports both ends of the shaft and the output rod 76 of the hydraulic actuator 74. And a load cell 82 for indirectly measuring. 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 connected to the outer periphery of the band-shaped metal member 12 indicated by an arrow d in FIGS. 10 and 11. The surface 24 is moved in the direction of pressing the inner peripheral 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 to the arrows shown in FIGS. It is moved in a direction away from the band-shaped metal member 12 indicated by e. Further, the hydraulic actuator 74 is based on a neutral surface N (see FIG. 12) of the bending stress σ _bC due to the moving roller 70 of the band-shaped metal member 12 based on a signal representing the second load F2 supplied from the load cell 82. In order to apply the stress to the band-shaped metal member 12 in such a manner that only the inner peripheral side is plastically deformed and the fixed roller 68 is not plastically deformed but only the moving roller 70 is plastically determined. The second load F2 is controlled so as to satisfy the following two conditions.

The first of the two conditions is that, on the outer peripheral side of the neutral surface N of the band-shaped metal member 12, the tensile stress σ _TC applied to the band-shaped metal member 12 by the moving roller 70 and the band-shaped metal by the fixed roller 68. Range in which the sum of the bending stress σ _{bA ′} applied to the member 12 and the residual stress σ _{rA applied} to the band-shaped metal member 12 in the circumferential length adjusting step P8 is smaller than the yield stress σ _y0 of the band-shaped metal member 12 To make it as large as possible. The second of the above two conditions is that the tensile stress σ _TC 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 and the band-shaped by the moving roller 70 A _{range in} which the _{sum of the} bending stress σ _bC applied to the metal member 12 and the residual stress σ _{rA applied} to the band-shaped metal member 12 in the circumferential length adjusting step P8 is smaller than the yield stress σ _y0 of the band-shaped metal member 12 To make it as large as possible. The tensile stress σ _TC , bending stress σ _bC , and bending stress σ _{bA ′} are represented by the following formulas (3) to (5). In Expression (3), T2 is the circumferential tension of the band-shaped metal member 12, and is calculated based on the second load F2 and the moving amount of the moving roller 70 from a predetermined relationship, for example. In Expression (2), r _C is the radius of the moving roller 70, and r _{A ′} is the radius of the fixed roller 68.
σ _TC = T2 / A1 (3)
σ _bC = E * (t / 2) / (r _C + (t / 2)) (4)
σ _{bA ′} = E * (t / 2) / (r _{A ′} + (t / 2)) (5)

  Returning to FIG. 10, in the residual stress applying step P <b> 9, the residual stress applying device 66 configured as described above is used, and the band-shaped metal members 12 are respectively wound around the pair of fixed rollers 68 in a slack state. Then, one of the fixed rollers 68 is driven to rotate by the electric motor so that the belt-shaped metal member 12 is rotated in the circumferential direction as indicated by an arrow f, while the moving roller 70 is rotated as indicated by an arrow d. When the outer peripheral surface 24 of the belt-shaped metal member 12 is moved in the direction to press the inner peripheral side, a predetermined stress that causes plastic deformation only on the inner peripheral side of the neutral surface N (see FIG. 12) of the band-shaped metal member 12 is belt-shaped. The metal member 12 is provided.

FIG. 12 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 belt-like metal member 12 is subjected to tensile stress σ _TC by the moving roller 70 shown by a one-dot chain line in FIG. 12 and bending stress σ _bC by the moving roller 70 shown by a two-dot chain line in FIG. And are given. Further, what is indicated by a long broken line is the residual stress σ _{rA 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 step P9 is increased from the yield stress σ _y0 to the yield stress σ _y1 as indicated by an arrow g in FIG. 13 due to work hardening in the previous step. .

In FIG. 12, the yield region S2 in which the total stress σ2 exceeds the yield stress σ _y1 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.

When the second load F2 is removed from the state as described above and the belt-shaped metal member 12 is brought into a free state, the band-shaped metal member 12 is deformed so as to return the strain to the original state. Remains strained. 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. 14 _shows the thickness direction of the residual stress σ _rC remaining due to the stress excluding the residual stress σ _rA among the residual stress σ _r remaining on the band-shaped metal member 12 in the free state. FIG. As shown in FIG. 14, a compressive residual stress is applied to the inner peripheral portion of the band-shaped metal member 12 toward the inner peripheral side. FIG. 15 is a view showing the distribution in the thickness direction of the residual stress σ _r remaining in the free-form strip-shaped metal member 12. As shown in FIG. 15, a 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 portion and the outer peripheral portion, and a tensile residual stress remains in the central portion. .

  Returning to FIG. 4, after the residual stress applying step P9, in the aging treatment step P10, the strip metal member 12 is subjected to an aging treatment. 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 step P11, the band-shaped metal member 12 is subjected to nitriding treatment. 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. 16 is a diagram showing the distribution in the thickness direction of the residual stress σ _{rN applied} to the band-shaped metal member 12 by the nitriding treatment. As shown in FIG. 16, by the nitriding treatment, compressive residual stresses that are larger toward the inner peripheral side and the outer peripheral side are left on the inner peripheral portion and the outer peripheral portion of the band-shaped metal member 12, respectively. A tensile residual stress is left. Then, the residual stress σ _rN shown in FIG. 16 is applied in addition to the residual stress σ _r applied up to the previous step, whereby the distribution in the thickness direction of the residual stress of the band-shaped metal member 12 is shown in FIG. The distribution is as follows.

  Next, in the stacking step P12, the nine band-shaped metal members 12 having different peripheral lengths are stacked in close contact with each other so that the peripheral length increases 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 moving roller 44 is fixed to the fixed roller 42 and the moving roller 44 (first rotating roller) while rotating the belt-shaped metal member 12 in the circumferential direction. 42, the circumferential length adjusting step P8 for extending the circumferential length of the band-shaped metal member 12 and the band-shaped metal member 12 wound around the pair of fixed rollers (second rotating rollers) 68 are rotated in the circumferential direction. Meanwhile, by locally pressing the outer peripheral surface 24 of the band-shaped metal member 12 toward the inner peripheral side using the moving roller (third rotating roller) 70 provided on the outer peripheral side of the band-shaped metal member 12, since it contains a residual stress application step P9 to impart compressive residual stress sigma _rC the inner periphery of the belt-shaped metal member 12, the inner circumferential surface 22 of the belt-shaped metal member 12 in the circumferential length adjusting step P8 outer peripheral Locally it is tensile residual stress sigma _rA1 the inner periphery of the belt-shaped metal member 12 by being pressed remains, compressive residual stress on the inner peripheral portion of the belt-shaped metal member 12 in the residual stress application step P9 towards Since σ _rC is applied, the inner circumference of the band-shaped metal member 12 against the minimum residual stress required on the compression side when the band-shaped metal member 12 is used as a component of the laminated ring 14 of the transmission belt 10. Since the strength margin of the portion is large (large), the durability of the band-shaped metal member 12 can be improved.

  Incidentally, FIG. 26 is a diagram showing the distribution in the thickness direction of the residual stress of a conventional band-shaped metal member manufactured without performing the residual stress applying step P9. As indicated by an arrow k in FIG. 26, the residual stress in the inner peripheral portion of the conventional belt-shaped metal member is required on the compression side as a minimum when the laminated ring 14 of the transmission belt 10 is composed of six belt-shaped metal members. There is a problem that the residual stress is distributed on the tension side rather than the residual stress indicated by the two-dot chain line. For this reason, the strength of the laminated ring 14 is not sufficient to form the six strip-shaped metal members, and it is composed of nine strip-shaped metal members. The residual stress distribution indicated by the long broken line on the right side of the residual stress distribution of the two-point difference line is required at least on the compression side when the laminated ring 14 of the transmission belt 10 is composed of nine strip metal members. This shows the residual stress. In contrast, as shown in FIG. 3, the residual stress of the band-shaped metal member 12 of the present embodiment is at least on the compression side when the laminated ring 14 of the transmission belt 10 is composed of six band-shaped metal members. Since it is distributed on the compression side, that is, on the left side from the required residual stress indicated by a two-dot chain line, the strength of the laminated ring 14 is sufficiently ensured even if the laminated ring 14 is composed of six strip-shaped metal members. . Therefore, it is possible to reduce the weight of the laminated ring 14 as compared with the case where the laminated ring 14 is composed of nine strip-shaped metal members, and the manufacturing cost of the transmission belt 10 can be reduced.

Moreover, according to the manufacturing method of the laminated ring 14 of a present Example, in the residual stress provision process P9, in order to plastically deform only a part of the inner peripheral side rather than the neutral surface N of the strip | belt-shaped metal member 12, strip | belt-shaped metal On the outer peripheral side of the neutral surface N of the member 12, the tensile stress σ _TC applied to the band-shaped metal member 12 by the moving roller 70, the bending stress σ _{bA ′} applied to the band-shaped metal member 12 by the fixed roller 68, The second acting on the band-shaped metal member 12 from the moving roller 70 so that the sum of the residual stress σ _{rA applied} to the band-shaped metal member 12 in the adjustment step P8 is smaller than the yield stress σ _{y0 of the} band-shaped metal member 12. Since the load F2 is controlled, the plastic deformation region (yield region) of the band-shaped metal member 12 in the residual stress applying step P9 becomes a part in the thickness direction and the peripheral length of the band-shaped metal member 12 is changed. Therefore, the compressive residual stress can be applied to the inner peripheral portion of the strip-shaped metal member 12 without changing the peripheral length of the strip-shaped metal member 12 adjusted in the peripheral length adjusting step P8.

Moreover, according to the manufacturing method of the laminated ring 14 of a present Example, in the residual stress provision process P9, in the outer peripheral side rather than the neutral surface N of the strip | belt-shaped metal member 12, the tension | tensile_strength added to the strip | belt-shaped metal member 12 by the moving roller 70. The _{sum of the} stress σ _TC , the bending stress σ _bC applied to the band-shaped metal member 12 by the moving roller 70, and the residual stress σ _{rA applied} to the band-shaped metal member 12 in the circumferential length adjusting step P8 is the band-shaped metal member 12. Since the outer peripheral surface 24 of the band-shaped metal member 12 is locally pressed toward the inner peripheral side by the moving roller 70 so that the yield stress σ _y0 of the band-shaped metal member 12 becomes smaller, the band-shaped metal member 12 is plastically deformed by the fixed roller 68. Without being limited to this, only a part of the thickness direction is plastically deformed only by the moving roller 70, so that the residual stress distribution of the band-shaped metal member 12 is prevented from varying in the circumferential direction. It is possible.

  Next, another embodiment of the present invention will be described. In the following description of the embodiments, portions that overlap each other are denoted by the same reference numerals and description thereof is omitted.

  FIG. 17 is a diagram showing the distribution of the residual stress in the thickness direction of the band-shaped metal member 100 (see FIG. 2) according to another embodiment of the present invention. As shown in FIG. 17, compressive residual stress remains in the outer peripheral portion and the inner peripheral portion in the thickness direction of the band-shaped metal member 100. And the tensile residual stress remains in the center part of the thickness direction of the strip | belt-shaped metal member 100. FIG. The residual stress of the belt-shaped metal member 100 of the present embodiment is greater than the residual stress indicated by the two-dot chain line required on the compression side at the minimum when the laminated ring 14 of the transmission belt 10 is composed of six belt-shaped metal members. The compression side, that is, the left side. Furthermore, the band-shaped metal member 100 has a large margin for the residual stress distribution indicated by the two-dot chain line as compared with the band-shaped metal member 12 of Example 1 described above.

  Further, the strip-shaped metal member 100 has a thickness direction distance from the inner peripheral surface 22 to the position where the maximum tensile residual stress acts, with respect to a distance A in the thickness direction from the inner peripheral surface 22 to the neutral surface N indicated by a one-dot chain line. Residual stress is applied so that the ratio of the distance B is about 100%. Further, in the band-shaped metal member 100, the ratio of the distance D in the thickness direction from the outer peripheral surface 24 to the position where the maximum tensile residual stress is applied to the distance C in the thickness direction from the outer peripheral surface 24 to the neutral surface N is about Residual stress is applied so as to be 100%.

  In FIG. 4, in the circumference adjusting step P20, the annular member 38 subjected to the second solution treatment is adjusted to a predetermined circumference. FIG. 18 is a diagram conceptually showing the circumference adjusting device 102 used in the circumference adjusting step P20. FIG. 19 is a cross-sectional view showing a cross section taken along the line XIX-XIX of the circumferential length adjusting device 102 of FIG. 18 and 19, the circumferential length adjusting device 102 is part of the circumferential direction of the band-shaped metal member 100 wound around the fixed roller 42 and the moving roller 44, as compared with the circumferential length adjusting device 40 of the first embodiment. In FIG. 4, the measuring machine 104 for measuring the thickness t and the width W of the band-shaped metal member 100 and the axial force acting on the output rod 52 of the hydraulic actuator 50 are measured to move the belt-shaped metal member 100 from the moving roller 44. The configuration is the same except that a load cell 106 that indirectly measures the acting first load F1 is added.

In the circumference adjustment step P20, the circumference adjustment device 102 configured as described above is used, and in the same manner as the circumference adjustment step P8 of the first embodiment, the relationship obtained experimentally in advance is shown in FIG. Based on the displacement Y from the original position of the moving roller 44 indicated by the two-point difference line, the circumferential length of the band-shaped metal member 100 is adjusted to a predetermined value, and as shown in FIG. A larger compressive residual stress is applied to the outer periphery of the belt-shaped metal member 100, and a predetermined tensile residual stress _σrA1 is _applied to the inner periphery of the band-shaped metal member 100. Further, in the circumferential length adjusting step P20, the thickness t and the width W of the band-shaped metal member 100 immediately before the end of the circumferential length adjusting step P20 and the first load F1 acting on the band-shaped metal member 100 from the moving roller 44 are detected. .

  Returning to FIG. 4, following the circumference adjusting step P20, in the residual stress applying step P21, the same residual stress applying device 66 as that used in the residual stress applying step P9 of Example 1 is used, and the peripheral length is set. A compressive residual stress is applied to the inner peripheral portion of the adjusted band-shaped metal member 100. The residual stress applying step P21 of the present embodiment is different from the residual stress applying step P9 of the first embodiment in the following points.

In the residual stress applying step P21 of the present embodiment, the thickness t and the width W of the band-shaped metal member 100 immediately before the end of the circumferential length adjusting step P20, and the relationship expressed by the following equations (6) and (7) determined in advance: Based on the first load F1 immediately before the end of the circumferential length adjusting step P20, the circumferential tension T1 and the cross-sectional area A1 of the band-shaped metal member 100 immediately before the end of the circumferential length adjusting step P20 are calculated, and the following equation (8 ), The yield stress σ _y1 when the residual stress applying step P21 of the band-shaped metal member 100 is executed is calculated based on the calculated tension T1 and cross-sectional area A1.
T1 = F1 / 2 (6)
A = t * W (7)
σ _y1 = T1 / A (8)

Further, in the residual stress applying step P21, the hydraulic actuator 74 _causes the neutral surface of the belt-shaped metal member 100 to be based on the calculated yield stress σ _y1 and a signal representing the second load F2 supplied from the load cell 82. N (see FIG. 20), a predetermined stress that causes plastic deformation in a region as wide as possible on the inner circumference side, and plastic deformation only by the moving roller 70 without plastic deformation by the fixed roller 68. In order to give to the metal member 100, the second load F2 is controlled so as to satisfy the following two theoretically obtained conditions.

The first of the two conditions is that the tensile stress σ _TC applied to the band-shaped metal member 100 by the moving roller 70 on the neutral surface N of the band-shaped metal member 100 and the outer peripheral side thereof, and the fixed roller 68 The sum of the bending stress σ _{bA ′} applied to the band-shaped metal member 100 by the above and the residual stress σ _rA applied to the band-shaped metal member 100 in the circumferential length adjusting step P8 is less than the yield stress σ _y1 of the band-shaped metal member 100. In addition, the sum of the tensile stress σ _TC and the residual stress σ _rA is made equal to the yield stress σ _{y1 of} the strip metal member 100 on the neutral plane N of the strip metal member 100. The second of the above two conditions is that the tensile stress σ _TC applied to the band-shaped metal member 100 by the moving roller 70 on the neutral surface N of the band-shaped metal member 100 and the outer peripheral side thereof, and the moving roller The _{sum of the} bending stress σ _bC applied to the band-shaped metal member 100 by 70 and the residual stress σ _rA applied to the band-shaped metal member 100 in the circumferential length adjusting step P8 is less than the yield stress σ _y1 of the band-shaped metal member 100. It is to be.

FIG. 20 is a diagram showing a distribution in the thickness direction of the total stress σ3 obtained by adding a plurality of stresses applied to the band-shaped metal member 100 in the residual stress applying step P21. As shown in FIG. 20, in the residual stress applying step P21, a yield region S3 in which the total stress σ3 exceeds the yield stress σ _y1 of the band-shaped metal member 100 is allowed on the inner peripheral side of the neutral surface N of the band-shaped metal member 100. As much as possible. The band-shaped metal member 100 is plastically deformed in the circumferential direction as the entire inner circumferential side from the neutral surface N is directed toward the inner circumferential side, and the outer circumferential side is elastically deformed.

When the second load F2 is removed from the state as described above and the belt-shaped metal member 100 is brought into a free state, the band-shaped metal member 100 is deformed so as to return the strain to the original state. Remains. During the deformation, the inner peripheral portion of the band-shaped metal member 100 is compressed in the circumferential direction toward the inner peripheral side where the residual strain is larger. FIG. 21 shows the distribution of the residual stress σ _{rC in} the thickness direction of the residual stress remaining in the free-form band-like metal member 100 except for the residual stress σ _rA, that is, the residual stress σ _rC. FIG. As shown in FIG. 21, a compressive residual stress is applied to the inner peripheral portion of the band-shaped metal member 100 toward the inner peripheral side. Compared to the case of the first embodiment shown in FIG. 14, a larger residual stress σ _rC is applied to a wider region of the inner peripheral portion of the band-shaped metal member 100 in the case of the present embodiment.

  According to the manufacturing method of the laminated ring 14 of the present embodiment, the moving roller 44 is fixed to the fixed roller 42 and the moving roller 44 (first rotating roller) while rotating the belt-shaped metal member 100 in the circumferential direction. 42, the circumferential length adjusting step P20 for extending the circumferential length of the band-shaped metal member 100 and the band-shaped metal member 100 wound around the pair of fixed rollers (second rotating rollers) 68 are rotated in the circumferential direction. However, by locally pressing the outer peripheral surface 24 of the band-shaped metal member 100 toward the inner peripheral side using the moving roller (third rotating roller) 70 provided on the outer peripheral side of the band-shaped metal member 100, And a residual stress applying step P21 for applying a compressive residual stress to the inner peripheral portion of the band-shaped metal member 100. Even if a tensile residual stress remains in the inner peripheral portion of the band-shaped metal member 100 by locally pressing the surface 22 toward the outer peripheral side, the inner surface of the band-shaped metal member 100 is applied in the residual stress applying step P21. Since the compressive residual stress is applied, the strength of the inner peripheral portion of the strip-shaped metal member 100 against the minimum residual stress required on the compression side when the strip-shaped metal member 100 is used as a component of the transmission belt 10. Since the margin is large (large), the durability of the band-shaped metal member 100 can be improved as in the first embodiment.

Moreover, according to the manufacturing method of the lamination | stacking ring 14 of a present Example, the residual stress provision process P21 is based on the tension | tensile_strength T1 and the cross-sectional area A1 of the circumferential direction of the strip | belt-shaped metal member 100 just before completion | finish of the circumferential length adjustment process P20. The yield stress σ _y1 at the end of the circumferential length adjusting process P20 of the band-shaped metal member 100 is calculated, and the tensile stress σ _TC applied to the band-shaped metal member 100 by the moving roller 70 on the neutral surface N of the band-shaped metal member 100; The outer peripheral surface 24 of the band-shaped metal member 100 is set to the inner circumference so that the sum of the residual stress σ _{rA applied} to the band-shaped metal member 100 in the circumferential length adjusting step P8 is equal to the yield stress σ _y1 of the band-shaped metal member 100. Compressive residual stress is applied to the widest possible region of the inner peripheral portion of the band-shaped metal member 100 as long as the peripheral length of the band-shaped metal member 100 is not changed. It can be imparted. Therefore, the band-shaped metal member 100 has a strength margin with respect to the minimum required strength on the compression side in order to form the laminated ring 14 of the transmission belt 10 as compared with the band-shaped metal member 12 of the first embodiment. Can be much (larger).

FIG. 22 is a process diagram for explaining a manufacturing process of the laminated ring 14 (see FIG. 1) according to another embodiment of the present invention. In addition, the strip | belt-shaped metal member 12 (refer FIG. 1) which comprises the laminated ring 14 of a present Example has the residual stress as shown in FIG. In FIG. 22, in the residual stress removal process P30, the band-shaped metal member 12 is heated to a temperature equal to or higher than the _AC1 transformation point and held at that temperature, and then gradually cooled, whereby the band-shaped metal member 12 is formed by the previous process. Residual residual stress is removed.

Next, in the residual stress applying step P31, the same peripheral length adjusting device 40 as that used in the peripheral length adjusting step P8 is used, and the compressive residual stress σ is applied to the outer peripheral portion of the band-shaped metal member 12 as shown in FIG. _rA is given. In the residual stress applying step P31, the same residual stress applying apparatus 66 as that used in the residual stress applying process P9 of FIG. 4 of Example 1 is used, and as shown in FIG. A larger compressive residual stress is applied to the inner peripheral portion toward the inner peripheral side. As a result, the distribution of the residual stress in the thickness direction of the band-shaped metal member 12 is as shown in FIG.

  The configuration other than the above is the same as that of the first embodiment, and according to the method for manufacturing the laminated ring 14 of the present embodiment, the durability of the band-shaped metal member 12 can be improved as in the first embodiment.

Moreover, according to the manufacturing method of the lamination | stacking ring 14 of a present Example, the strip | belt-shaped metal member 12 consists of steel, and before the residual stress provision process P31, the strip | belt-shaped metal member 12 is made into temperature more than _AC1 transformation point. Since it includes a residual stress removing step P30 for removing the residual stress of the band-shaped metal member 12 by heating and holding it at that temperature, it is attached to the band-shaped metal member 12 before the residual stress applying step P31. By removing the residual stress, the accuracy of the residual stress applied to the band-shaped metal member 12 in the residual stress applying step P31 can be 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.

  Further, the mechanical configuration of the residual stress applying device 66 is disclosed as an example, and can be realized even with other known mechanical configurations. For example, the hydraulic actuator used to move the moving roller 70 may be replaced with another type of actuator such as an electric type or a pneumatic type. Further, three or more fixed rollers 68 may be provided.

  Further, in place of the residual stress applying device 66, a residual stress applying device 200 shown in FIG. 23 may be used. 24 is a view showing a cross section taken along the line XXIV-XXIV in FIG. 23, and FIG. 25 is a view showing a cross section taken along the line XXV-XXV in FIG. The residual stress applying device 200 includes a fixed roller 68 and a moving roller 202 provided on the inner peripheral side of the band-shaped metal member 12, and an outer peripheral surface 24 of the band-shaped metal member 12 wound around the fixed roller 68 and the moving roller 202. A fixed roller 204 that presses locally on the inner peripheral side is provided. As shown in FIG. 24, the support member 80 that rotatably supports the fixed roller 204 is fixed to the support wall 72 via a support member 206. As shown in FIG. 25, the moving roller 202 is selectively moved in either the direction approaching the fixed roller 68 indicated by the arrow h by the hydraulic actuator 50 or the direction separating from the fixed roller 68 indicated by the arrow i. Moved. In the residual stress applying device 200 configured as described above, the band-shaped metal member 12 is wound around the fixed roller 68 and the moving roller 202 in a slack state, and the moving roller 202 is rotationally driven by the electric motor 58. While the belt-shaped metal member 12 is rotated in the circumferential direction as indicated by j, the moving roller 202 is separated from the fixed roller 68 as indicated by an arrow i, whereby the outer peripheral surface 24 of the belt-shaped metal member 12 is fixed by the fixed roller 204. Is pressed to the inner peripheral side.

  Further, the circumferential length adjusting device 40 (102) is disclosed as an example of a mechanical configuration for extending the strip-shaped metal member 12 (100) in the circumferential direction, and may have other known mechanical configurations. Realized. For example, a plurality of fixed rollers 42 may be provided. Further, the moving roller 44 is not limited to one that moves in a direction away from the fixed roller 42 in order to extend the band-shaped metal member 12 (100) in the circumferential direction, and is provided, for example, between a pair of fixed rollers 42. You may press the inner peripheral surface of the strip | belt-shaped metal member 12 toward an outer peripheral side.

  Further, the outer peripheral surfaces of the fixed roller 42 and the moving roller 44 do not necessarily have an arc shape that is convex on the outer peripheral side in a cross section passing through the shaft centers C1 and C2. For example, it may be formed in a cylindrical surface shape.

  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.

10: Transmission belt 12: Band-shaped metal member 14: Laminated ring 18: Element 24: Outer peripheral surface 42: Fixed roller (first rotating roller)
44: Moving roller (first rotating roller)
68: Fixed roller (second rotating roller)
70: Moving roller (third rotating roller)
A1: Cross-sectional area N1, N2: Neutral line P8, P20: Peripheral length adjusting process P9, P21, P31: Residual stress applying process P30: Residual stress removing process T, T1, T2: Tension σ _TC : Tensile stress by moving roller 70 (Tensile stress by the third rotating roller)
σ _bC : bending stress due to the moving roller 70 (bending stress due to the third rotating roller)
σ _{bA ′} : Bending stress by the fixed roller 68 (bending stress by the second rotating roller)
σ _rA : Residual stress (residual stress applied to the band-shaped metal member in the circumference adjustment step)
σ _y0 , σ _y0 : yield stress

Claims (5)

A method of manufacturing a laminated ring, which is formed by laminating a plurality of endless annular band-shaped metal members in close contact with each other and used for a transmission belt of a belt type continuously variable transmission for a vehicle to support a plurality of elements linked in an annular shape. There,
By rotating at least two first rotating rollers in a circumferential direction using at least two first rotating rollers around which the band-shaped metal members are wound, the at least two first rotating rollers are relatively separated from each other. A circumferential length adjusting step for extending the circumferential length of the metal member;
Using the third rotating roller provided on the outer peripheral side of the band-shaped metal member while rotating the band-shaped metal member in the circumferential direction using at least two second rotating rollers around which the band-shaped metal member is wound. By pressing the outer peripheral surface of the band-shaped metal member locally toward the inner peripheral side and bending the band-shaped metal member along the outer peripheral surface of the third rotating roller , compressive residual stress is applied to the inner peripheral portion of the band-shaped metal member. Including a residual stress applying step to be applied ,
The method for manufacturing a laminated ring, wherein the residual stress applying step plastically deforms only the inner peripheral side of the neutral surface of the band-shaped metal member . In the residual stress applying step, the tensile stress applied to the band-shaped metal member by the third rotating roller on the outer peripheral side of the neutral surface of the band-shaped metal member, and the band-shaped metal member by the second rotating roller are applied to the band-shaped metal member. The outer peripheral surface of the band-shaped metal member is adjusted to be smaller than the yield stress of the band-shaped metal member so that the sum of the bending stress generated and the residual stress applied to the band-shaped metal member in the circumferential length adjusting step is smaller than the yield stress of the band-shaped metal member. method for manufacturing a laminated ring according to claim 1, characterized in that locally pressed towards the side. The residual stress applying step includes applying a tensile stress applied to the band-shaped metal member by the third rotating roller on the outer peripheral side of the neutral surface of the band-shaped metal member, and applying to the band-shaped metal member by the third rotating roller. The outer peripheral surface of the band-shaped metal member is adjusted to be smaller than the yield stress of the band-shaped metal member so that the sum of the bending stress generated and the residual stress applied to the band-shaped metal member in the circumferential length adjusting step is smaller than the yield stress of the band-shaped metal member. method for manufacturing a laminated ring according to claim 1 or 2, characterized in that locally pressed towards the side. The residual stress applying step includes
Based on the circumferential tension and cross-sectional area of the band-shaped metal member immediately before the end of the circumference adjustment process, the yield stress at the end of the circumference adjustment process of the band-shaped metal member is calculated,
On the neutral surface of the strip metal member, the sum of the tensile stress applied to the strip metal member by the third rotating roller and the residual stress applied to the strip metal member in the circumference adjustment step is The lamination according to any one of claims 1 to 3 , wherein the outer peripheral surface of the band-shaped metal member is locally pressed toward the inner peripheral side so as to be equal to the yield stress at the end of the peripheral length adjusting step. Ring manufacturing method. The band-shaped metal member is made of steel,
The lamination according to any one of claims 1 to 4 , further comprising a residual stress removing step of removing the residual stress by heating the band-shaped metal member to an _AC1 transformation point or higher before the residual stress applying step. Ring manufacturing method.

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