JP5488416B2 - Manufacturing method of outer ring for toroidal type continuously variable transmission - Google Patents

Description

  The present invention relates to an improvement in a method for manufacturing an outer ring incorporated in a toroidal type continuously variable transmission used as an automatic transmission for an automobile. Specifically, a manufacturing method that can efficiently manufacture an outer ring for realizing a structure that can smoothly displace the power roller with respect to the trunnion to ensure high transmission efficiency and ensure excellent durability. It is to provide.

[Description of prior art]
The use of toroidal continuously variable transmissions as automotive transmissions has been described in many publications and is partly implemented and well known. In particular, Patent Document 1 describes a toroidal continuously variable transmission having various structures. FIG. 12 shows a basic configuration of a toroidal type continuously variable transmission which is described in Patent Document 1 and is currently being implemented. First, the first example of this conventional structure will be briefly described. A pair of input disks 1a and 1b are concentric with each other with the input side inner surfaces 3 and 3 facing each other with respect to the input rotating shaft 2 and the input side inner surfaces 3 and 3 being toroidal curved surfaces (concave arc-shaped concave surfaces). In addition, it supports the synchronized rotation freely.

  An output cylinder 5 having an output gear 4 fixed on the outer peripheral surface of the intermediate portion is supported around the intermediate portion of the input rotary shaft 2 so as to freely rotate with respect to the input rotary shaft 2. Further, output disks 6 and 6 are supported at both ends of the output cylinder 5 so as to be rotatable in synchronization with the output cylinder 5 by spline engagement. In this state, the output-side inner surfaces 7 of the output disks 6 and 6, each of which is a toroidal curved surface, face the input-side inner surfaces 3 and 3.

  In addition, two power rollers 8 and 8 each having a spherical convex surface in the peripheral portion (cavity) between the input side and output side inner side surfaces 3 and 7 around the input rotation shaft 2 are provided. It is arranged. The power rollers 8 and 8 are respectively connected to the inner surfaces of the trunnions 9 and 9 via support shafts 10 and 10 whose base half and tip half are eccentric and a plurality of rolling bearings. 10 is supported so as to be freely rotatable and slightly displaceable around the base half of each of the support shafts 10 and 10.

  The trunnions 9 and 9 are swingable and displaceable about the tilting shafts provided concentrically for each trunnion 9 and 9 at both ends in the length direction (front and back direction in FIG. 12). is there. The operation of swinging (tilting) each of the trunnions 9 and 9 is performed by displacing each of the trunnions 9 and 9 in the axial direction of each of the tilting shafts by a hydraulic actuator. At the time of shifting, the trunnions 9 and 9 are displaced in the axial direction of the tilt shafts by supplying and discharging pressure oil to and from the actuators. As a result, the direction of the force acting in the tangential direction of the contact portion (traction portion) between the peripheral surface of each of the power rollers 8 and 8 and each of the input side and output side inner surfaces 3 and 7 changes (side slip occurs). Therefore, the trunnions 9 are oscillated and displaced about the tilt axes.

  During operation of the toroidal type continuously variable transmission as described above, one input disk 1a (left side in FIG. 12) is rotationally driven by the drive shaft 11 via the loading cam type pressing device 12. As a result, the pair of input disks 1a and 1b supported at both ends of the input rotation shaft 2 rotate synchronously while being pressed toward each other. This rotation is transmitted to the output disks 6 and 6 through the power rollers 8 and 8 and is taken out from the output gear 4.

  When the ratio of the rotational speeds of the input rotary shaft 2 and the output gear 4 is changed, and when the deceleration is first performed between the input rotary shaft 2 and the output gear 4, the respective trunnions 9, 9 are shown in FIG. The peripheral surfaces of the power rollers 8 and 8 are swung to the positions shown in FIG. 4 and the portions near the center of the input side inner surfaces 3 and 3 of the input disks 1a and 1b and the output sides of the output disks 6 and 6, respectively. The inner side surfaces 7 and 7 are brought into contact with the outer peripheral portion. On the other hand, when increasing the speed, the trunnions 9 and 9 are swung in the direction opposite to that shown in FIG. 12, and the peripheral surfaces of the power rollers 8 and 8 are moved to the input sides of the input disks 1a and 1b. It is made to contact | abut to the outer peripheral part of the inner side surfaces 3 and 3 and the center side part of the output side inner side surfaces 7 and 7 of the said output discs 6 and 6, respectively. An intermediate speed ratio (transmission ratio) can be obtained between the input rotary shaft 2 and the output gear 4 by setting the swing angles of the trunnions 9 and 9 to an intermediate position.

  During operation of the toroidal type continuously variable transmission as described above, the members used for power transmission, that is, the input side and output side disks 1a, 1b, 6 and the power rollers 8, 8 are It is elastically deformed based on the pressing force (thrust) generated by the pressing device 12. Then, along with this elastic deformation, the disks 1a, 1b, 6 are displaced in the axial direction. Further, the pressing force generated by the pressing device 12 increases as the torque transmitted by the toroidal continuously variable transmission increases, and the amount of elastic deformation of each member increases accordingly. Accordingly, in order to properly maintain the contact state between the side surfaces 3 and 7 on the input side and the output side and the peripheral surfaces of the power rollers 8 and 8 regardless of the fluctuation of the torque, 8 is required to displace the disc 8 in the axial direction of the discs 1a, 1b, 6 with respect to the trunnions 9, 9. In the case of the first example of the conventional structure shown in FIG. 12, the tip half of each of the support shafts 10 and 10 that support the power rollers 8 and 8 is similarly oscillated and displaced about the base half. Thus, the power rollers 8, 8 are displaced in the axial direction.

  In the case of the first example of such a conventional structure, the structure for displacing each of the power rollers 8 and 8 in the axial direction is complicated, and parts production, parts management, and assembly work are both troublesome and costly. It is inevitable that it is bulky. As a technique for solving such a problem, Patent Document 1 describes a structure as shown in FIGS. A feature of the second example of this conventional structure is that the power roller 8a is supported on the trunnion 9a so that the input side and output side disks 1a, 1b, 6 (see FIG. 12) can be displaced in the axial direction. The overall structure and operation of the toroidal-type continuously variable transmission are the same as those of the first example of the conventional structure shown in FIG.

  The trunnion 9a constituting the second example of the conventional structure exists between a pair of tilting shafts 13 and 13 provided concentrically with each other at both ends, and between these tilting shafts 13 and 13, and at least A support beam 15 having a cylindrical convex surface 14 on the inner side (upper side in FIGS. 14 to 16) in the radial direction (up and down direction in FIGS. 14 to 16) of both the input side and output side disks 1a, 1b, 6; Is provided. The tilting shafts 13 and 13 are respectively connected to yokes (not shown because of a well-known structure) or swinging frame support plate portions (FIGS. 71 and 72 of Patent Document 1) via radial needle bearings 16 and 16, respectively. Are supported so as to be able to swing.

Further, as shown in FIGS. 14 and 15, the central axis A of the cylindrical convex surface 14 is parallel to the central axis B of the both tilting shafts 13, 13, and the central axis B of the both tilting shafts 13, 13 is. Rather than the outer side (the lower side of FIGS. 14 to 16) in the radial direction of each of the disks 1 a, 1 b, 6. Further, a concave portion 19 having a partial cylindrical surface is formed on the outer surface of the outer ring 18 constituting the thrust ball bearing 17 provided between the support beam portion 15 and the outer surface of the power roller 8a. It is provided in a crossing state. And this recessed part 19 and the cylindrical convex surface 14 of the said support beam part 15 are engaged, The rocking | fluctuation displacement regarding the axial direction of each said disk 1a, 1b, 6 is made for the said outer ring 18 with respect to the said trunnion 9a. I support it as possible. Examples curvature radius r ₁₉ of the cross-sectional shape of the recess 19 the radius of curvature r ₁₄ or more of the cross-sectional shape of the cylindrical convex surface 14 (r ₁₉ ≧ r _14), the recesses 19 and the cylindrical convex surfaces 14, the entire surface or the recess It is made to contact | abut directly in the bottom vicinity part of 19. FIG.

  A support shaft 10a is fixed to the center of the inner surface of the outer ring 18 integrally with the outer ring 18, and the power roller 8a is rotatable around the support shaft 10a via a radial needle bearing 20. I support it. Further, a downstream oil supply passage 21 for supplying lubricating oil to the thrust ball bearing 17 and the radial needle bearing 20 is provided inside the outer ring 18 and the support shaft 10a. An upstream oil supply passage 22 connected to the downstream oil supply passage 21 is provided. The downstream spherical oil passage 21 corresponds to the center hole described in the claims. These oil supply passages 21 and 22 communicate with each other regardless of the rocking displacement of the outer ring 18 through a recessed hole 31 formed in the central portion of the recessed portion 19, and further, the outside of the support beam portion 15. In addition, an oil supply pipe 23 connected to the upstream oil supply path 22 is provided. The upstream end of the oil supply pipe 23 is opened to the inner diameter side of the pulley 24 provided at the end of the trunnion 9 a for bridging the synchronous cable, and the lubricating oil is supplied through the inner diameter side of the pulley 24. It is possible.

  Further, a pair of stepped surfaces 25 and 25 facing each other are provided on the inner surface of the trunnion 9a at a continuous portion between both end portions of the support beam portion 15 and the tilting shafts 13 and 13. Then, these stepped surfaces 25, 25 and the outer peripheral surface of the outer ring 18 constituting the thrust ball bearing 17 are brought into contact with or in close proximity to each other, and the traction force applied from the power roller 8a to the outer ring 18 is It can be supported by either of the step surfaces 25, 25.

According to the toroidal type continuously variable transmission of the second example of the conventional structure configured as described above, the power roller 8a is displaced in the axial direction of each of the disks 1a, 1b, 6 so as to elastically deform the constituent members. A structure that can properly maintain the contact state between the peripheral surface of the power roller 8a and each of the disks 1a, 1b, 6 regardless of the amount can be configured easily and at low cost.
That is, during operation of the toroidal type continuously variable transmission, each of the power rollers 8a is connected to each of the disks 1a, 1b, 6 based on the elastic deformation of the input side, output side disks 1a, 1b, 6, and each power roller 8a. When it is necessary to displace axially, the outer ring 18 of the thrust ball bearing 17 that rotatably supports each of the power rollers 8a is provided with a concave portion 19 having a partially cylindrical surface provided on the outer surface and the supporting beam portion. While sliding the contact surface with the 15 cylindrical convex surface 14, the cylindrical convex surface 14 is oscillated and displaced about the central axis a. Based on this oscillating displacement, a portion of the peripheral surface of each power roller 8a that is in rolling contact with one axial side surface of each disk 1a, 1b, 6 is the axial direction of each disk 1a, 1b, 6. To maintain the contact state appropriately.

  As described above, the central axis (a) of the cylindrical convex surface (14) is greater than the central axes (B) of the two tilting shafts (13, 13) that are the swing centers of the trunnions (9a) during the shifting operation. It exists outside in the radial direction of 1b and 6. Therefore, the rocking radius of the rocking displacement centered on the central axis A of the cylindrical convex surface 14 is larger than the rocking radius at the time of the speed change operation, and the input disks 1a and 1b and the output disk 6 There is little effect on the change in the transmission ratio during this period (it can be ignored or can be easily corrected).

When the second example of the conventional structure as described above is implemented, as shown in FIG. 16A, the curvature radius r ₁₉ of the cross-sectional shape of the concave portion 19 is set to the curvature of the cross-sectional shape of the cylindrical convex surface 14. Generally, it is larger than the radius r ₁₄ (r ₁₉ > r ₁₄ ). The reason for this is that when both the radii of curvature r ₁₉ and r ₁₄ are equal to each other (r ₁₉ = r ₁₄ ), the inner surface of the concave portion 19 and the cylindrical convex surface 14 come into contact with the entire surface of the portions facing each other, This is because it becomes difficult to feed the lubricating oil into the contact portion. The inner surface of the concave portion 19 and the cylindrical convex surface 14 are oscillated and displaced while being in contact with each other with a large surface pressure. It becomes easy to generate excessive wear based on it.

However, when larger than the radius of curvature r ₁₄ of the cross-sectional shape of the cylindrical convex surface ₁₄ (r _19> r 14) also produces the following (1) such problem (2).
(1) The inner surface of the concave portion 19 and the cylindrical convex surface 14 are likely to be locally worn.
(2) It is difficult to ensure the durability of the thrust ball bearing 17.
Of these, the problem (1) occurs because the inner surface of the concave portion 19 and the cylindrical convex surface 14 are almost only at the bottom or near the bottom of the concave portion 19 as shown in FIG. This is because the contact is made in a state close to line contact, and the contact surface pressure becomes high.

  The reason for the occurrence of the problem (2) is that the outer ring 18 is elastically deformed in a direction in which the inner side surface thereof is a partially convex cylinder based on a large thrust load applied to the thrust ball bearing 17 from the power roller 8a. It is to do. As is well known in the technical field of toroidal-type continuously variable transmissions, a large thrust load is applied to the thrust ball bearing 17 from the power roller 8a when the half-toroidal toroidal-type continuously variable transmission subject to the present invention is operated. Will be added. Based on this thrust load, the outer ring 18 constituting the thrust ball bearing 17 causes the inner surface of the concave portion 19 to follow the cylindrical convex surface 14 as shown exaggeratedly in FIG. These two surfaces are elastically deformed in a direction in which both surfaces are almost entirely contacted. With this elastic deformation, the distance between the outer ring raceway 28 provided on the inner side surface of the outer ring 18 and the inner ring raceway 27 provided on the outer side surface of the power roller 8a is not the same in the circumferential direction of the outer ring 18. become. As the distance between the two tracks 28 and 27 is different, the surface pressure of the rolling contact portion between the tracks 28 and 27 and the rolling surfaces of the balls 26 and 26 (see FIG. 12) is changed to the outer ring 18. It becomes remarkably different with respect to the circumferential direction. Specifically, at two positions opposite to the length direction of the trunnion 9a (the axial direction of the support beam portion 15), the rolling contact between the raceways 28 and 27 and the rolling surfaces of the balls 26 and 26 occurs. The surface pressure of the part becomes excessive. As a result, the rolling fatigue life of both the tracks 28 and 27 is remarkably shortened at two positions on the opposite side in the length direction, which is an obstacle to ensuring the durability of the toroidal continuously variable transmission.

[Description of Prior Invention]
In view of the circumstances as described above, the contact area between the inner surface of the concave portion formed on the outer surface of the outer ring constituting the thrust ball bearing and the cylindrical convex surface provided on the support beam portion constituting the trunnion is secured, and these Japanese Patent Application No. 2009-267177 is a structure that suppresses wear on both sides and suppresses elastic deformation of the outer ring to ensure the durability of the thrust ball bearing and improve the durability of the entire toroidal continuously variable transmission. There is an invention disclosed in. Since the manufacturing method of the present invention relates to a method for manufacturing an outer ring incorporated in the toroidal type continuously variable transmission according to the previous invention, first, regarding the structure and operation of the toroidal type continuously variable transmission according to the previous invention, This will be described with reference to FIGS.

In the structure according to the previous invention, the concave portion 19a formed in a state of penetrating the outer surface of the outer ring 18a in the radial direction of the outer ring 18a (both ends open at positions radially opposite to the outer peripheral surface of the outer ring 18a). The inner surface is not a single cylindrical surface, but has a Gothic arch-like cross-sectional shape in which a pair of side concave curved surface portions 29, 29 and a central concave curved surface portion 30 are smoothly continuous. Of these, the two sides concave surface portion 29 and 29, wherein is provided in the width direction both side portions of the recess 19a, the radius of curvature r ₂₉ of the cross-sectional shape, a cylindrical convex surface of the supporting beam portion 15 constituting the trunnions 9a larger than the radius of curvature r ₁₄ of the outer peripheral surface of _{14 (r 29> r 14)} . In contrast, the central concave surface portion 30 is provided in the widthwise central portion of the concave portion 19a, the radius of curvature r ₃₀ of the cross-sectional shape, than the radius of curvature r ₁₄ of the outer circumferential surface of the cylindrical convex surface 14 Is also small (r ₃₀ <r ₁₄ ). The both side concave curved surface portions 29 and 29 and the central concave curved surface portion 30, each having the curvature radii r ₂₉ and r ₃₀ as described above, are the center side edges of the both side concave curved surface portions 29 and 29. And the both side edges 30 of the central concave curved surface portion share a tangent line with each other so that they are smoothly continuous.

The outer ring 18a and the trunnion 9a are combined in a state in which the support beam portion 15 on the trunnion 9a side is fitted in the recess 19a on the outer ring 18a side. In such a combined state, the cylindrical convex surface 14 of the support beam portion 15 and the both side concave curved surface portions 29 and 29 abut at two positions in the circumferential direction with respect to the outer peripheral surface of the support beam portion 15. The central angle θ relating to both the abutting portions can be arbitrarily adjusted based on the ratio of the respective curvature radii r ₂₉ , r ₃₀ , r ₁₄ . As the central angle θ increases, the effect of preventing the outer ring 18a from elastically deforming as shown in FIG. However, the greater the central angle θ, the greater the force applied in the direction of widening the gap between the two side concave curved surface portions 29, 29, and the greater the tensile stress applied to the bottom of the recess 19a or the vicinity thereof. . Conversely, the smaller the central angle θ, the smaller the force applied in the direction of widening the gap between the both side concave curved surface portions 29, 29, and the smaller the tensile stress applied to the bottom portion of the concave portion 19a or the vicinity thereof. . However, the smaller the central angle θ, the smaller the effect of preventing the outer ring 18a from elastically deforming as shown in FIG. Therefore, the central angle θ is appropriately regulated within a range in which the elastic deformation of the outer ring 18a is suppressed and the tensile stress applied to the bottom portion or the vicinity thereof is not excessive. Specifically, the ratios of the respective radii of curvature r ₂₉ , r ₃₀ , r ₁₄ are determined so that the central angle θ falls within the range of 90 ° ± 30 °.

With the structure according to the prior invention configured as described above, a toroidal continuously variable transmission having sufficient durability can be realized.
That is, in the case of the toroidal type continuously variable transmission of the previous invention, the inner surface of the concave portion 19a formed on the outer surface of the outer ring 18a constituting the thrust ball bearing 17a and the cylindrical convex surface 14 provided on the support beam portion 15; Are brought into contact with each other at two positions in the circumferential direction of both surfaces. For this reason, the contact area of the inner surface of the concave portion 19a and the cylindrical convex surface 14 can be secured, the surface pressure of the contact portions on both surfaces can be kept low, and wear on both surfaces can be suppressed.

  Further, since the inner surface of the concave portion 19a and the cylindrical convex surface 14 are brought into contact with each other at two positions separated in the circumferential direction of the support beam portion 15, a large thrust load is applied to the outer ring 18a. In addition, it is possible to suppress the outer ring 18a from being elastically deformed so that the inner side becomes a convex cylindrical surface as shown in FIG. In other words, the height of the inner surface of the outer ring 18a can be kept unchanged in the circumferential direction. Therefore, the distance between the outer ring raceway 28 provided on the inner side surface of the outer ring 18a and the inner ring raceway 27 provided on the outer side surface of the power roller 8a is substantially constant with respect to the circumferential direction of the both raceways 28 and 27. Can be reduced (the degree of disagreement can be suppressed). For this reason, it can prevent that the surface pressure of the rolling contact part of both the said tracks 28 and 27 and the rolling surface of each said balls 26 and 26 becomes partially excessive. As a result, it is possible to ensure the durability of the thrust ball bearing 17a, and thus the durability of the toroidal type continuously variable transmission incorporating the thrust ball bearing 17a.

  Further, in the case of the structure according to the previous invention, the center side edge of the both side concave curved surface portions 29, 29 and the both side edges of the central concave curved surface portion 30 are smoothly continuous. Even when a large force in a direction away from each other is applied between the both side concave curved surface portions 29, 29 in accordance with the pressing with the 15 cylindrical convex surfaces 14, the tensile force applied to the bottom portion of the concave portion 19a or the vicinity thereof Stress can be reduced. As a result, it is possible to prevent the outer ring 18a from being damaged such as a crack. Further, by providing the central concave curved surface portion 30, the central angle θ can be increased when the damage prevention performance of the outer ring 18a is the same as the tensile stress applied to the bottom of the concave portion 19a or the vicinity thereof can be reduced. It becomes possible to do. And the effect which suppresses the elastic deformation of the said outer ring | wheel 18a can be enlarged by enlarging this center angle (theta).

  As described above, the structure according to the previous invention has a great effect in terms of ensuring high transmission efficiency by smoothly displacing the power roller with respect to the trunnion and ensuring excellent durability. However, there is a problem in terms of reducing the manufacturing cost of the outer ring 18a constituting the structure for this purpose. That is, as in the conventional structure shown in FIG. 16A, the concave portion 19 having a constant radius of curvature over the entire width and a partially concave cylindrical surface is formed on the outer surface of the outer ring 18. If it forms, this recessed part 19 can be easily formed by an industrial method by using a general rotary tool. On the other hand, the concave portion 19a having a Gothic arch-like cross-sectional shape is formed by grinding with a grindstone in which the cross-sectional shape of the outer peripheral surface is the same shape (the bus bar shape is the same and the concavities and convexities are reversed), or As a general method, wire-cut electric discharge machining is considered. However, any of these methods has a low processing efficiency, which increases the manufacturing cost of the outer ring 18a.

  In particular, the outer ring 18a needs to quench and harden the outer ring raceway 28 formed in a portion of the inner surface surrounding the support shaft 10a. Then, with the heat treatment for quench hardening, the portion near the outer diameter of the outer ring 18a tends to be deformed in the directions indicated by arrows α and α in FIG. The direction and amount of this deformation vary depending on various conditions such as quenching conditions, and the variation in the machining allowance during finishing processing increases. Decreasing and, in turn, manufacturing costs are likely to increase significantly.

JP 2008-25821 A

  In view of the circumstances as described above, the present invention provides an outer ring for realizing a structure capable of smoothly performing displacement of the power roller with respect to the trunnion, ensuring high transmission efficiency, and ensuring excellent durability. Invented to realize a production method capable of producing efficiently.

  The outer ring for the toroidal type continuously variable transmission, which is the object of the manufacturing method of the present invention, supports the trunnion so as to be able to swing and displace the power roller while being engaged with the cylindrical convex surface of the support beam. In order to support, a concave portion penetrating in the radial direction is provided on the outer side surface, a support shaft is provided in the central portion of the inner side surface, and a central hole opening on the outer side side is provided in the central portion of the support shaft. The concave portion is provided on both sides in the width direction and has a Gothic arch-shaped cross-sectional shape including a pair of side concave curved surface portions having a radius of curvature of the cross-sectional shape larger than that of the cylindrical convex surface. And a state in which a plurality of rolling elements are installed between the thrust inner ring raceway formed on the inner side surface of the power roller disposed around the support shaft via the radial bearing and the thrust outer ring raceway formed on the inner side surface Used in.

The manufacturing method of the present invention for producing such an outer ring for a toroidal-type continuously variable transmission includes a portion of the concave portion in contact with the cylindrical convex surface of the support beam portion and having a cross-sectional shape of a Gothic arch-shaped portion. At least a portion of the support beam that contacts the cylindrical convex surface is formed by plastic processing that transfers the surface shape of the processing surface of the mold.
At the same time, the central part reference surface is formed in the opening of the central hole and the other part of the mold for processing the Gothic arch-shaped part is located at the inner surface of the recess and becomes the center of the outer surface. It is formed by plastic working that presses the second working surface provided on the surface and transfers the shape of the second working surface.
Thereafter, the outer ring raceway and the outer peripheral surface of the support shaft are finished with reference to the Gothic arch-shaped portion and the center reference surface.

  Preferably, when the outer ring for a toroidal-type continuously variable transmission according to the present invention as described above is carried out, among the inner surfaces of the recess, the support beam portion is preferably formed as in the invention described in claim 2. After forming the intermediate material in which the portion that contacts the cylindrical convex surface is protruded from the other portion, only the portion protruding from the other portion and the opening of the center hole are processed surfaces of the mold Press.

According to the method for manufacturing an outer ring for a toroidal continuously variable transmission of the present invention configured as described above, the power roller can be smoothly displaced with respect to the trunnion to ensure high transmission efficiency, and excellent durability. The outer ring for realizing the structure that can secure the efficiency can be efficiently manufactured.
That is, the plastic working of the concave portion of the support beam portion that contacts the cylindrical convex surface and the center reference surface of the opening of the center hole should be performed on the die working surface of the intermediate material. By pressing against the part and transferring the shape of the processed surface to the part to be processed, this can be done easily and quickly. The processing surface of the mold needs to be processed with high precision, but if one mold is made, a large number of outer rings can be processed, so even if the processing of the processing surface is troublesome, the toroidal type steplessly The efficiency relating to the production of the outer ring for the transmission is reduced, and the production cost of the outer ring for the toroidal type continuously variable transmission does not increase.

Further, in a state where the portion of the concave portion that contacts the cylindrical convex surface of the support beam portion and the central reference surface portion of the opening portion of the center hole are finished by plastic working, the surface accuracy of these both portions and the mutual accuracy of each portion are determined. The positional relationship accuracy is sufficiently high. For this reason, if the outer ring surface of the outer ring raceway and the support shaft are finished with these two parts as a reference, the outer ring raceway and the outer circumference surface of the support shaft can be finished with sufficient accuracy and efficiency.
In addition, as described in claim 2, if the processing surface of the mold is pressed only to the portion of the inner surface of the recess that protrudes from the other portion, the processing area can be kept small, Not only can the load on the mold and the pressing device be reduced, but also the residual stress in the outer ring as the workpiece can be reduced.

The perspective view shown in the state which looked at the outer ring | wheel from the outer surface in order to demonstrate the 1st example of embodiment of this invention. Sectional drawing similarly shown with a single outer ring. Sectional drawing shown in the state similarly combined with the trunnion. In order to finish the outer ring raceway and the outer peripheral surface of the support shaft after plastic working the portion of the concave portion that contacts the cylindrical convex surface of the support beam portion and the central portion reference surface portion of the opening of the center hole, The perspective view which shows the state in the middle of mounting | wearing with the holding | maintenance part of a processing apparatus. Sectional drawing which shows the state mounted | worn similarly. The perspective view which shows the state which finishes the outer peripheral surface of a support shaft after mounting | wearing. The perspective view which shows the state which similarly finishes an outer ring track. Sectional drawing for demonstrating the dimension which should be considered in order to perform these finishing processes accurately. The perspective view which shows the state which assembled | attached the outer ring | wheel after finishing to a trunnion, and was set as the power roller unit. Furthermore, the perspective view which shows the state which assembled | attached the power roller. The figure similar to FIG. 1 which shows the 2nd example of embodiment of this invention. Sectional drawing which shows the 1st example of a conventional structure. The perspective view which looked at the trunnion which supported the power roller via the thrust ball bearing which shows the 2nd example of the conventional structure from the radial direction outer side of each disk. Similarly, the front view shown in the state seen from the circumferential direction of the disk. Similarly sectional drawing. XX sectional drawing of FIG. 14 which shows the state (A) which shows the state before a thrust load is applied to a thrust ball bearing from a power roller, and the state (B) after a thrust load is applied. The perspective view which looked at the trunnion which supported the power roller via the thrust ball bearing which shows an example of the structure which concerns on a prior invention from the radial direction inner side of each disk. FIG. 18 is an enlarged YY sectional view of FIG. 17. The perspective view shown in the state which took out the outer ring | wheel which comprises a thrust ball bearing, and was seen from the opposite side to FIG. Sectional drawing shown in the state which took out the outer ring | wheel which comprises a thrust ball bearing from FIG. Sectional drawing for demonstrating the state which an outer ring deform | transforms with the heat processing of an outer ring track.

[First example of embodiment]
FIGS. 1-10 has shown the 1st example of embodiment of this invention, and FIGS. 1-2 of these shows the outer ring | wheel 18b for toroidal type continuously variable transmissions manufactured by the manufacturing method of this invention. ing. This outer ring 18b is a recess formed in the outer surface in a state penetrating in the radial direction of the outer ring 18b, like the outer ring 18a (see FIGS. 19 to 20) incorporated in the toroidal-type continuously variable transmission according to the previous invention. The inner surface of 19b is not a single cylindrical surface, but has a Gothic arch-like cross-sectional shape in which a pair of side concave curved surface portions 29a, 29a and a central concave curved surface portion 30a are continuous. The radius of curvature related to the cross-sectional shape of each of the concave curved surfaces 29a, 30a, and the radius of curvature of the cross-sectional shape of the cylindrical convex surface 14a of the support beam portion 15a of the trunnion 9b shown in FIGS. The relationship is the same as in the case of the previous invention.

  In particular, in the case of the outer ring 18b manufactured by the manufacturing method of the present invention, the both side concave curved surface portions 29a and 29a that are in contact with the cylindrical convex surface 14a in the assembled state of the toroidal type continuously variable transmission, It protrudes slightly from the other portion, that is, the central concave curved surface portion 30a. Accordingly, step portions 32 and 32 exist between the concave curved surface portions 29a and 30a, respectively. The height of these stepped portions 32, 32, that is, the amount by which the both side concave curved surface portions 29a, 29a protrude from the central concave curved surface portion 30a is determined by the following both side concave curved surface portions 29a, 29a. In order to obtain a non-concentric partial cylindrical surface shape constituting the Gothic arch shape, when the side concave curved surface portions 29a, 29a are pressed and plastically deformed by a mold, the mold is deformed on both side concave curved surfaces. It is made as small as possible within a range that does not interfere with the portions other than the portions 29a and 29a. In the case of the outer ring 18b incorporated in a general toroidal type continuously variable transmission for a passenger car, it is sufficient to secure the height of the step portions 32 and 32, for example, about 0.5 to 2 mm.

  The outer surface shape of the outer ring 18b including the concave curved surface portions 29a and 30a as described above is described in FIGS. 1-2 by sequentially deforming a material made of a metal material (carbon steel) as a material by forging. Obtained by approaching the shape. And let the said both-sides concave curved surface part 29a and 29a which is the characteristics of this invention be an intermediate material just before making it the non-concentric partial cylindrical surface shape which comprises Gothic arch shape. The process until obtaining the intermediate material is basically the same as a method widely known in the field of forging by a mold. Of course, the shape of the mold (punch and die) used in each process is regulated according to the outer ring 18b to be obtained. The downstream oil supply passage 21 which is the center hole described in the claims is formed by cutting (drilling) using a drilling machine or the like after the intermediate material is formed by forging. The portion of the intermediate material that is to become the outer ring raceway 28 is heat-treated and hardened by partial quenching such as induction quenching.

After the intermediate material as described above is obtained by subjecting the material to forging and partial cutting, a finishing mold is pressed against the outer surface of the intermediate material. The shape of the processed surface of the mold, that is, the portion of the surface that is pressed against a part of the intermediate material to transfer the surface shape to the intermediate material has the following characteristics (1) to (3).
(1) In order to make the both side concave curved surface portions 29a and 29a (parts along the broken lines c and c in FIG. 2) into a non-concentric partial concave cylindrical surface shape constituting a Gothic arch shape, this partial concave cylindrical surface A partially convex cylindrical surface shape in which the shape and the unevenness are reversed is provided in a portion that abuts against the portion that should become the both side concave curved surface portions 29a and 29a.
(2) In the state where the partially convex cylindrical surface-shaped portion is abutted against the portions to be the both side concave curved surface portions 29a, 29a, the opening portion of the downstream oil supply passage 21 (along the broken line D in FIG. 2). In this case, a convex portion having a conical or partial conical convex surface is provided to plastically deform this portion into a partial conical concave surface.
(3) The positional relationship between the central axis of the convex portion described in (2) above and the pair of partially convex cylindrical surface-shaped portions described in (1) above is determined in the outer ring 18b after completion. It is made to correspond with the positional relationship of the center axis | shaft of the support shaft 10a, and the said both sides concave curved-surface part 29a, 29a.

  The surface shape has the above-mentioned features (1) to (3), the mold is pressed against the intermediate material, and the both side concave curved surface portions 29a and 29a are non-concentric to form a Gothic arch shape. And plastically deforming the opening of the downstream oil supply passage 21 into a central reference surface 33, which is a partially conical concave surface. Since the shape and positional relationship of each part of the mold are strictly regulated, the both side concave curved surface parts 29a and 29a and the center are also transferred with respect to the intermediate material to which the shape of each part of the mold is transferred. The shape and positional relationship with the part reference surface 33 are strictly regulated as desired. What is obtained in this way is the final intermediate material having the same surface properties and dimensions as the outer ring 18b after completion, except for the outer ring raceway 28 and the outer peripheral surface of the support shaft 10a. Of the final intermediate material, a conical concave receiving portion 39 as shown in FIGS. 1, 4 and 5, for example, is formed in the central portion of the front end surface of the support shaft 10a by cutting or the like. The receiving recess 39 is formed, for example, by abutting a cutting tool against the tip surface of the support shaft 10a in a state where the support shaft 10a is held by a chuck of a rotary high-speed machine such as a lathe. In any case, the receiving recess 39 is strictly positioned at the center of the tip surface of the support shaft 10a.

After the above preparation is completed, the outer ring raceway 28 and the outer peripheral surface of the support shaft 10a are finished on the basis of the both side concave curved surface portions 29a, 29a and the central portion reference surface 33. In the case of this example, this finishing process is performed as shown in FIGS.
First, as shown in FIGS. 4 to 5, the final intermediate material is assembled to a chuck 34 provided at the tip of the spindle of the machine tool. At this time, the final intermediate material is positioned by using the both side concave curved surface portions 29a and 29a and the central portion reference surface 33 as a reference. Specifically, the center axis of the support shaft 10a is aligned with the center of rotation of the main shaft, and the final intermediate material is positioned in the axial direction of the support shaft 10a.

  For this purpose, a columnar spacer 36 whose outer diameter is strictly regulated is spanned between a pair of V blocks 35 and 35 arranged at two positions on the front side of the chuck 34 in the radial direction. In addition, a taper surface provided at the tip of the positioning receiving pin 38 that is inserted into the slide hole 37 formed so as to penetrate the central portion of the spacer 36 in the radial direction without rattling is formed on the central portion reference surface 33. Engage. Further, a tapered surface formed at the tip of the positioning push pin 40 arranged concentrically with the main shaft is engaged with the receiving recess 39. The positioning receiving pin 38 is disposed concentrically with the main shaft and the positioning push pin 40, and is provided with an elastic member such as a compression spring 41 or a hydraulic actuator (not shown). Elasticity in the direction toward the push pin 40 is applied. Accordingly, the front end surface of the positioning push pin 40 and the receiving recess 39 are engaged, and the final intermediate material is pushed in by the positioning push pin 40 while the positioning receiving pin 38 is pushed in. By pressing toward the surface, the center axis of the support shaft 10a and the center of rotation of the main shaft can coincide with each other, and the final intermediate material can be positioned in the axial direction of the support shaft 10a. In this state, the both side concave curved surface portions 29a, 29a formed on the final intermediate material by the plastic working abut against the outer peripheral surface of the spacer 36.

  Therefore, as shown in FIGS. 6 to 7, the outer ring raceway 28 and the outer peripheral surface of the support shaft 10a are finished. Among these, the finishing of the outer peripheral surface of the support shaft 10a is performed by scraping the outer peripheral surface of the support shaft 10a with a cutting tool 42 as shown in FIG. 6 while rotating the final intermediate material together with the main shaft. . Further, in the finishing process of the outer ring raceway 28, while rotating the final intermediate material together with the main shaft, as shown in FIG. 7, the bus bar shape of the outer peripheral surface is matched with the bus bar shape of the outer ring raceway 28 after completion. Further, the grindstone 43 (with the concavities and convexities being reversed) is rotated by rotating the grindstone 43 around the central axis of the grindstone 43 against the portion to be the outer ring raceway 28.

  In the case of the manufacturing method of the present example configured as described above, the both side concave curved surface portions 29a and 29a contacting the cylindrical convex surface 14a of the support beam portion 15a in the concave portion 19b, and the downstream side Plastic processing of the center reference surface 33 portion of the opening of the side oil supply passage 21 can be performed easily and quickly by pressing the processing surface of the mold against the portion of the intermediate material to be processed. For this reason, the outer ring 18b for realizing a structure that can smoothly displace the power roller with respect to the trunnion 9b to ensure high transmission efficiency and ensure excellent durability can be efficiently manufactured. As a result, it is possible to contribute to lowering the cost of the toroidal continuously variable transmission having excellent performance.

  In particular, a plurality of outer rings 18b are provided in a single toroidal-type continuously variable transmission, each of which rotatably supports the power roller, and the tilt angles of the power rollers coincide with each other when the gear ratio is changed. In order to achieve this (to ensure synchronization stability), it is necessary to match the dimensions of each part strictly. For example, as shown in FIG. 8, the pitch circle diameter D of the outer ring raceway 28 constituting the thrust ball bearing 17 (see FIG. 12), each ball 26 constituting the thrust ball bearing 17 from the tilt center of the outer ring 18b, The height H to the center of 26, the outer diameter d of the support shaft 10a, the symmetry of each part, etc. need to be strictly regulated. According to the manufacturing method of this example, the dimensions D, H, d and the symmetry of each part can be regulated relatively easily and with high accuracy. It should be noted that the symmetry of each of these parts means that the center of the pitch circle diameter D, the center of the outer diameter d of the support shaft 10a, and the center of the spacer 36 engaged with the side concave curved surface parts 29a, 29a (support The degree to which the central axis of the beam portion 15a coincides with the same in the center position in the width direction of the both side concave curved surface portions 29a and 29a. In other words, it means the degree of deviation of the center of the pitch circle diameter D and the center of the spacer 36 from the extension line of the central axis with respect to the outer peripheral surface of the support shaft 10a. As these centers coincide, in other words, the better the symmetry, the better the synchronization stability of the power rollers.

  The outer ring 18b manufactured as described above is combined with the support beam portion 15a of the trunnion 9a as shown in FIG. 9, and a plurality of balls 26, 26 (see FIG. 12) are disposed on the outer ring raceway 28. The thrust ball bearing 17 is configured by arranging the power roller 8a via the reference). A power roller unit as shown in FIG.

[Second Example of Embodiment]
FIG. 11 shows a second example of the embodiment of the present invention. In the case of this example, of the pair of side concave curved surface portions 29b and 29b formed on both side portions of the concave portion 19c formed on the outer side surface of the outer ring 18c, only the intermediate portion in the radial direction of the outer ring 18c is The concave curved surface portion 30b and the both side concave curved surface portions 29b and 29b are protruded from both ends in the radial direction of the outer ring 18c.
For this reason, in the case of this example, a portion of the both side concave curved surface portions 29b and 29b that abuts on the cylindrical convex surface 14a (see FIG. 3) of the support beam portion 15a is a partially concave cylinder constituting a Gothic arch shape. The force required for processing into a planar shape can be further reduced compared to the case of the first example of the embodiment described above.
Since the configuration and operation of the other parts are the same as in the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted.

DESCRIPTION OF SYMBOLS 1a, 1b Input disk 2 Input rotary shaft 3 Input side inner surface 4 Output gear 5 Output cylinder 6 Output disk 7 Output side inner surface 8, 8a Power roller 9, 9a Trunnion 10, 10a Support shaft 11 Drive shaft 12 Press device 13 Inclination Roller shaft 14, 14a Cylindrical convex surface 15, 15a Support beam 16 Radial needle bearing 17, 17a Thrust ball bearing 18, 18a, 18b, 18c Outer ring 19, 19a, 19b, 19c Recess 20 Radial needle bearing 21 Downstream oil supply path 22 Upstream oil supply passage 23 Oil supply pipe 24 Pulley 25 Stepped surface 26 Ball 27 Inner ring raceway 28 Outer ring raceway 29, 29a, 29b Side concave curved surface portion 30, 30a, 30b Central concave curved surface portion 31 Recessed hole 32 Stepped portion 33 Central portion reference surface 34 Chuck 35 V block 36 Spacer 37 Slide hole 38 Position Receiving pin 39 receiving recess 40 positioning push pin 41 compression spring 42 the cutting tool 43 whetstone because

Claims (2)

  By engaging with the cylindrical convex surface of the support beam, the trunnion is supported so that it can swing and displace, and the power roller can be supported rotatably. A support shaft is provided at the center, and a center hole is formed at the center of the support shaft. The recess is provided at both sides in the width direction, and the curvature radius of the cross-sectional shape is the cylindrical convex surface. Having a Gothic arch-like cross-sectional shape with a pair of side concave curved surface portions larger than the radius of curvature of the power roller, and formed on the inner surface of a power roller disposed around the support shaft via a radial bearing A method for producing an outer ring for a toroidal-type continuously variable transmission used with a rolling element installed between a thrust inner ring raceway and a thrust outer ring raceway formed on an inner surface, wherein the support is supported in the recess. Cylindrical shape of the beam At the same time as processing the portion of the support beam portion abutting with the cylindrical convex surface of the gothic arch shape in contact with the surface by plastic processing that transfers the surface shape of the processing surface of the mold, A central reference surface is provided in the other part of the mold for processing the Gothic arch-shaped part at the opening of the central hole, which is located on the inner surface of the recess and becomes the center of the outer surface. A second working surface is pressed to form the second working surface and the plastic working is performed, and then the outer ring raceway and the support shaft are formed on the basis of the gothic arch-shaped portion and the center reference surface. A method for producing an outer ring for a toroidal-type continuously variable transmission, characterized in that the outer peripheral surface is finished.   Of the inner surface of the concave portion, after forming an intermediate material in which the portion that contacts the cylindrical convex surface of the support beam portion protrudes from the other portion, the portion protruding from the other portion, and the center The manufacturing method of the outer ring | wheel for toroidal type continuously variable transmissions of Claim 1 which presses the process surface of the said metal mold | die only to the opening part of a hole.

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