JP5625718B2 - Rolling method - Google Patents

Description

  The present invention relates to improvement of rolling processing accuracy of rolling processing of gears, splines, and the like, and particularly relates to improvement of variation in diameter such as an overpin diameter of an involute spline.

  Conventionally, there is known a rolling method for plastically processing screws, gears, splines, serrations, etc. on the outer periphery of a workpiece while holding and pressing a workpiece rotatably supported on the shaft center with a pair of dies arranged symmetrically about the shaft center. It has been. In such rolling processing, the finish dimensional accuracy of the workpiece is ensured by accurately controlling the distance between the dies. For example, Patent Document 1 discloses an example of an NC correction mechanism that can correct a distance between a pair of flat dies in accordance with an NC command. This can be performed by inputting a correction value to the apparatus, and the setup change when the flat die is exchanged is facilitated. For workpieces with different rolling widths of workpieces, the change in back force can be detected by the servo motor encoder of the correction device so that the flat die height can be corrected to be constant.

  However, since the rolling machine of Patent Document 1 detects the change in the back component force by the encoder of the servo motor of the correction device, the detection sensitivity of the change in the back component force is poor. Therefore, in order to improve the detection accuracy, in the patent document 2 of the rotary die for thread rolling, the distortion of the tension bar that connects between the two dies that cause distortion is significantly reflected by the reaction force during rolling. Measure with a gauge, calculate the weight (back component force) at the time of rolling based on this measured value, and further control the distance between the rotating dies so that this weight becomes the appropriate weight, and perform thread rolling with the appropriate weight. Like to do.

  On the other hand, the shape and accuracy may not always be ensured by a single rolling process. Therefore, workpieces are processed sequentially using multiple rolling machines, or multiple pairs of rolling flat dies are arranged in the axial direction on a single rolling machine, in the order of roughing, intermediate finishing, and finishing. Rolling processing is performed while moving the processing part of the workpiece in the axial direction (Patent Document 3). However, the equipment becomes large and complicated. Therefore, in Patent Document 4, the shape of the pair of flat dies arranged on both sides of the work is composed of a center finish tooth group and a pair of biting and flank tooth groups symmetrical on both sides of the pair, and the flat The die is reciprocated once or several times, and when each die reaches each reciprocating dead center, the distance (distance) between the two dies is gradually reduced each time, and the workpiece is processed for each movement of both dies. Rolling is performed by increasing the amount.

  Furthermore, in patent document 5, the finishing part used as the maximum height of the uneven part of a fixed-tooth shape, the adjustment part which becomes low gradually, and the relief part which becomes steep and low are provided symmetrically. Thus, when the workpiece is positioned at the escape portion, the workpiece is reciprocally rolled while gradually reducing the distance (distance) between the flat dies. Further, in FIGS. 6 to 8 of the conventional example of Patent Document 6, the serration is not rotated twice, but the thread rolling and the serration rolling are continuously performed. We are rolling.

Japanese Patent No. 2555381 JP 2003-285135 A Japanese Patent Publication No. 63-6296 JP 58-157541 A Japanese Patent Laid-Open No. 10-118733 JP-A-4-187337

  The accuracy of a gear is generally measured and evaluated by a so-called overpin diameter in which a predetermined pin is brought into contact with a tooth groove at a symmetrical position of the gear and a distance between the pins is measured. In any of the cases described above, reciprocating rolling or complex rolling is performed to increase this accuracy. In addition, the distance between the rolling dies is controlled with high accuracy. On the other hand, the workpiece material to be rolled is made of a relatively uniform material in order to improve the rolling accuracy.

  However, further improvement in rolling accuracy is desired. In addition, the work material has been procured in a wide range for reasons such as cost, and good rolling accuracy has been required even if a material with large variations is used.

  In view of such problems, an object of the present invention is to obtain a higher rolling accuracy, and also to obtain a good rolling accuracy with respect to changes in workpiece materials and variations in workpiece materials. is there.

  As a result of intensive studies on the workpiece material and rolling accuracy, the inventors of the present application cannot obtain stable dimensions simply by controlling the distance between the rolling dies at a constant level during finish rolling. In conventional flat die rolling machines, the distance between the bottom surfaces of flat dies is usually fixed after manual adjustment by the adjustment mechanism of the overpin diameter, so the hardness of the material of the rolled material varies In addition, because the rolling load increases and decreases, the distance between the bottom surfaces of the flat dies during rolling due to elastic deformation of the rolling machine also increases or decreases depending on the hardness, and the overpin diameter of the processed involute spline varies. Knew that would occur. That is, it has been found that the cause of the variation in rolling accuracy is due to the spring back after rolling due to the hardness and stickiness of the material. Furthermore, it was learned that the amount of springback is closely related to the back force during rolling.

According to this knowledge, in the present invention, a workpiece rotatably supported by an axial center, a pair of dies arranged symmetrically with respect to the axial center, and a strain sensor for detecting a back component force during rolling of the workpiece. When using the rolling machine with a distance between the pair of dies are controlled to be constant, and while sandwiching the workpiece is moved in the opposite directions to rolling the workpiece outer circumferential surface A rolling process method, wherein a plurality of roll forming command distances in which the distance between the pair of dies is set in advance with respect to the workpiece specifications, and a plurality of the above rolling process command distances with respect to the workpiece specifications. A rolling process command distance that determines the distance between the pair of dies as a function of the back component force measured by rolling different workpieces is set in advance, and the distance between the pair of dies is set to the front rolling. Set the machining command distance and move the workpiece forward. Machining, measuring the back component force during the previous rolling process, obtaining the post-rolling processing command distance from the measured back component force by the function, and obtaining the distance between the pair of dies. A rolling process method in which the work is post-rolled by setting a post-rolling process command distance. Rolling said seeking the rear rolling process instruction distance by the function from the measured back component force, the distance between the pair of dies is set to rolling instruction distance after determining the post-rolling said workpiece It is a manufacturing method, Comprising: The said front rolling process is a process which performs thread rolling to the said workpiece | work by using the flat die for screw rolling, The said post rolling process uses the flat die for involute splines In this way, an axial part of the workpiece processed by the pre-rolling process and an axial part of the workpiece processed by the post-rolling process are performed by performing involute spline rolling on the workpiece. In addition, the workpiece is processed while measuring the back component force of the workpiece using the strain sensor during the front rolling process, and the involute of the workpiece according to the back component force during the rear rolling process. And solve the problems described above by providing a rolling method for performing processing for correcting the spline over-pin diameter.

  That is, if the hardness or stickiness of the workpiece is large, the back force increases and the deformation of the rolling machine also increases. Therefore, the amount of spring back such as the distance between the dies of the workpiece and the rolling machine becomes large. On the other hand, if the hardness or stickiness of the workpiece is small, the back force is small and the deformation of the rolling machine is also small, and the amount of springback such as the distance between the die of the workpiece and the rolling machine is small. Based on this relationship, the back component force is measured in the previous step before rolling in the subsequent process (for example, finish rolling). If the back component force is smaller than the average, the springback amount is small. Make the distance between dies larger than the average (standard). Further, when the back force is greater than the average, the amount of spring back increases, so the distance between the dies is made smaller than the average to suppress the finished size.

  Such a relationship is previously rolled for each workpiece at a constant distance between dies, and the back component force at that time is measured so that an appropriate accuracy can be obtained with respect to the back component force of the previous rolling process. Find the distance between the dies in the subsequent rolling process. This data is stored in the control device of the rolling machine, and in the actual rolling process, the workpiece to be processed is pre-rolled, the back component force is measured during the pre-rolling process, and the post-rolling process is performed. Control the distance between the dies to reduce the effect of the springback amount.

  In order to ensure ease of control and accuracy, it is preferable that the pre-rolling is a rolling process that does not directly affect the rolling accuracy in the post-rolling. In addition, a change in the back force of the rolling process is detected by the strain sensor provided on the rolling machine body, and a minute change in the back force such as when the hardness of the work changes is detected with high sensitivity. It is preferable to do this.

Also, in combined rolling , in which thread rolling and involute spline rolling are rolled into the same workpiece, the rolling load is detected by using a flat die for thread rolling as a flat die for pre-rolling, and a flat for involute spline. The overpin diameter was automatically adjusted by using the die as a flat die for post-rolling . That is, a rolling method is used in which the axial part of the workpiece processed by the front rolling process is different from the axial part of the workpiece processed by the post-rolling process .

Furthermore, in the invention described in claim 2, the post-rolling process is a process of performing involute spline rolling on the workpiece by using a flat die for involute splines, and the tooth rolling is performed with respect to the axis of the workpiece. There is provided a rolling process method in which the stripes are parallel, or are rolled into a tooth shape of a helical or helical shape. According to a third aspect of the present invention, the rolling process method is such that the post-rolling process command distance is smaller than the pre-rolling process command distance.

  That is, in the thread rolling as the pre-rolling process, the rolling load is relatively small and the change in the diameter dimension due to the hardness of the workpiece is small, so that dimensional correction for each workpiece is not necessary. In addition, since the change in rolling load (back component force) is small, a change in load due to a change in workpiece hardness can be detected with high sensitivity. Therefore, rolling is preferably performed prior to rolling of a spline or the like. Based on the back component force detected by thread rolling, the distance between flat dies for splines as post-rolling is corrected. In spline rolling, since the rolling load is relatively large, the overpin diameter of the involute spline that easily changes depending on the hardness of the workpiece can be automatically corrected for each workpiece.

Further, this rolling method can be applied to round (rotating) dies as well as flat dies. Therefore, in the invention described in claim 4 , the pair of dies are rotary dies that can be rotated symmetrically about the axis, and the distance between the pair of dies is the pair of rotations. A rolling method that is the distance between the rotation axes of the dies was used.

  Accordingly, in the present invention, in the rolling process, a pre-rolling process is provided, the back component force in the pre-rolling process is measured, and a die set in advance according to the back component force of the pre-rolling process is measured. The distance between the dies for post-rolling is controlled each time (for example, when the back force is large, the distance between the dies is reduced, and when it is small, the distance between the dies is increased). Even if there is a variation in the above, it is possible to reduce the influence of spring back and the like, and to achieve a highly accurate rolling method. Furthermore, in involute spline rolling, it becomes possible to automatically correct the overpin diameter of the involute spline, which is likely to change depending on the hardness of the workpiece, for each workpiece. A stable overpin diameter can be obtained.

In addition, since the pre-rolling process is thread rolling, the load change due to the workpiece hardness change can be detected with high sensitivity, so that the post-rolling process can be corrected more accurately and the post-rolling process accuracy is improved. Involute splines, etc., have a relatively large rolling load, so the overpin diameter tends to change depending on the hardness of the workpiece. However, the overpinning can be automatically corrected for each workpiece according to the load in thread rolling. The diameter can be stabilized.

Further, in the invention according to claim 3 , since the gear rolling is performed in two or more steps and the post-rolling machining command distance is made smaller than the pre-rolling machining command distance, the conventional one-rotating rolling is changed to 2 It is possible to perform highly accurate rolling by simply measuring the back component force in the control of revolving or reciprocating or multi-rotating and changing the distance between the dies for post-rolling based on the result. Furthermore, in the invention described in claim 4 , since the pair of dies are rotating dies, and the distance between the rotating shafts of the pair of rotating dies is used, even a conventional machine can easily realize highly accurate rolling. It became a thing.

It is a front view of a rolling machine using a plurality of flat dies of screws and splines showing a first embodiment of the present invention. It is a schematic diagram of one side of the table which adjusts the distance between dies of the flat die of FIG. FIG. 3 is a view as seen from an arrow A in FIG. 2. It is the shape of the workpiece | work seen from A arrow of FIG. It is a front view of a flat die. 1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a relationship between a back component force of a thread rolling process and a three needle diameter of a screw, and FIG. 2B is a processed three needle diameter and a spline overpin diameter. It is a characteristic view showing the relationship with a dimension. It is a front view which shows the rolling process process which is 1st embodiment of this invention. (A) shows the start of thread rolling, (b) shows the start of spline rolling, and (c) shows the combined rolling completion position. It is a front view of the rolling machine using a set of flat dies which shows a second embodiment of the present invention. It is a schematic diagram of one side of the table which adjusts the distance between dies of the flat die of FIG. It is a characteristic view showing the relationship between the back component force of the pre-rolling process and the overpin diameter of the post-rolling process, showing the second embodiment of the present invention. It is a front view which shows the rolling process process which is 2nd embodiment of this invention. (A) shows the pre-rolling process start, (b) shows the completion of the pre-rolling process, (c) shows the return step, and (d) shows the post-rolling process completion position.

    A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a flat die type rolling machine using a plurality of flat dies of screws and splines according to the first embodiment of the present invention, and shows a state during screw rolling. 2 is a schematic diagram of one side of a table for adjusting the distance between the dies of the flat die of FIG. 1, FIG. 3 is a view taken along the arrow A in FIG. 2, and FIG. 4 is a shape of the work as viewed from the arrow A in FIG. FIG. 5 is a front view of a flat die. As shown in FIG. 4, a work (workpiece) 4 is held between a head stock 52 and a core pusher 53 provided so as to be opposed to the headstock 52, and is rotatably supported on an axis c. An example of the workpiece is CVJ, and reference numeral 51 denotes a cup portion into which the joint roller is inserted. As shown in FIG. 1, a pair of compound flat dies 21 to 24 are arranged in the rolling disk main body 16 with point symmetry with respect to the axis c.

  The compound flat die is a set of a screw machining die 21 (23) and a spline machining die 22 (24), and the left screw machining die 21 and the spline machining die 22 are placed downward and the right screw machining die 23. The spline processing die 24 is moved upward in the opposite direction while holding the workpiece 4 while maintaining a point-symmetrical relationship with respect to the axis c. As a result, the outer periphery of the workpiece is rolled in the order of thread rolling and involute spline rolling.

  As shown in FIG. 5, the flat die 22 is composed of a biting tooth portion 1, a finishing tooth portion 2, and a relief tooth portion 3, and a workpiece is formed from the biting tooth portion, and the finishing tooth portion and the relief tooth portion are arranged. After that, it is rolled. As shown in FIG. 1, the dies 21 to 24 are fixed to moving tables 19 and 20, respectively, and the moving tables 19 and 20 can be moved on the slides of the columns 17 and 18 in opposite directions and parallel to each other by a driving device (not shown). Has been. At this time, the force generated by the rolling process is the largest reaction force of the force that crushes the workpiece in the radial direction, that is, the back component force 27 that pushes the flat die perpendicular to the bottom surface.

  As shown in FIGS. 2 and 3, the flat dies 21 and 22 are fixed to the table 19 via a pair of wedge-shaped members 7 and 8, and the one wedge member 8 rotates the ball screw 9 by a servo motor 10. Thus, it can be moved in the vertical direction 11. That is, by giving a predetermined rotation command to the servo motor, the wedge member 8 is moved up and down by a predetermined amount, and the flat dies 21 and 22 are accurately moved in the horizontal directions 13 and 12 through the wedge surface. Thereby, the distance between dice | dies can be controlled. This makes it possible to change the target value of the three-needle diameter of the screw and the overpin diameter (hereinafter referred to as “OPD”) of the spline.

  As shown in FIG. 1, the columns 17 and 18 of the rolling board 16 are firmly fixed by a main body front panel 26 and a rear panel (not shown). The front and rear panels increase the rigidity of the columns 17 and 18, and hold and secure positions opposite to the back component force during rolling. A strain sensor 25 is attached to the front panel 26 so that the strain generated by pulling in the left-right 28 direction by the back component force during processing can be detected. The output of this strain sensor is proportional to the back component force. This back component force is substantially equivalent to detecting a force in the direction of the bottom of the pair of flat dies.

  In the first embodiment, such a rolling machine is used to roll the involute spline 14 and the screw 15 of the work of the outer race of the CVJ as shown in FIG. 6A and 6B show the first embodiment of the present invention, where FIG. 6A shows the relationship between the back component force of screw rolling and the three needle diameters of the screw, and FIG. 6B shows the processed three needle diameters and splines. It is a characteristic view showing the relationship with the overpin diameter size. As shown in FIG. 6 (a), when the three-needle dimension at the strain sensor output a is set to the target dimension (specified dimension), the three-needle diameter dimension is almost proportional to the increase in back force (ΔV). It can be seen that the three-screw diameter dimension of the workpiece and the back component force are in a substantially linear relationship. The three-needle diameter of the workpiece is determined by the size of the workpiece and flat dies at the time of rolling, and the amount of elastic deformation return (spring back) of the rolling machine. It is considered proportional to the component force.

  Further, when the distance between the dies at the time of the thread rolling process and the spline rolling process is made constant at a predetermined dimension, the relationship between the thread three needle diameter and the spline OPD is almost as shown in FIG. 6 (b). It is a linear proportional relationship. At this time, even if the distance between the dies is constant, each dimension changes due to a small difference in hardness between the workpieces. Since the spring back amount is large for a hard workpiece, the screw three needle diameter And spline OPD both increase, and vice versa for soft workpieces.

  From the above, measure the strain sensor output value at the time of thread rolling, and if the difference from the specified value is known, the difference from the target size of the screw three-needle diameter size from the target size of the OPD dimension of the spline You will see the difference. That is, the OPD dimension value to be corrected at the time of spline rolling can be obtained from the strain sensor output at the time of thread rolling.

  Based on these considerations, the relationship between the strain sensor output, the three needle diameter dimensions, and the spline OPD dimensions obtained from FIG. Describes how to stabilize and stabilize the OPD dimension of the workpiece when the back force changes.

  FIGS. 7A and 7B are front views showing a rolling process according to the first embodiment of the present invention. FIG. 7A shows a screw rolling process start, FIG. 7B shows a spline rolling process start, and FIG. Indicates the completion position. As shown in FIG. 7A, the left screw die 21 and the spline die 22 are moved downward as viewed in the figure, the right screw die 23 and the spline die 24 are moved upward as viewed in the figure, and the screw portion 15 is moved to a predetermined distance between the dice. In FIG. 7 (b), the product is pre-rolled and temporarily stopped at the screw rolling end position. The back component force at this time, preferably the back component force at the time of thread finish tooth rolling, is acquired by a strain sensor.

  Next, Δd1 is obtained from the difference between the strain sensor output value and the target value, ΔV in FIG. 6A, and the OPD dimension of the spline to be corrected is calculated as Δd2 corresponding to Δd1 in FIG. 6B. Next, each of the right and left dies is added to a predetermined additional amount for spline processing, and an amount that is ½ of the OPD dimension Δd2 to be corrected is further driven.

  Further, the die is moved forward again to perform the rolling process, and the rolling process is completed at the position shown in FIG. As a result, the spline OPD dimension of the machined work is stable and has a stable machining dimension even when the work hardness in the lot varies.

  Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a front view of a flat die type rolling machine using a pair of flat dies, showing a second embodiment of the present invention, and shows a state during the rolling process. FIG. 9 is a schematic view on one side of a table for adjusting the distance between the flat dies of FIG. Parts similar to those of the first embodiment described above are denoted by the same reference numerals, and a part of the description is omitted. The flat die 5 is the same as that shown in FIG. 5 described above, and is composed of a biting tooth portion 1, a finishing tooth portion 2, and a relief tooth portion 3. A workpiece is formed from the biting tooth portion, the finishing tooth portion, and the relief tooth portion. Rolled through the teeth.

  As shown in FIG. 8, the workpiece 4 is held by a center device (not shown), the left flat die 5 is kept downward in the figure, the right die 6 is kept upward, and the point c is kept symmetrical with respect to the center c. The rolling process is performed by moving while moving. The flat dies 5 and 6 are fixed to the moving tables 19 and 20, and the moving tables 19 and 20 move on the slides of the columns 17 and 18 in opposite directions and in parallel with each other by a driving device (not shown). At this time, the force generated by the rolling process is the largest reaction force of the force that crushes the workpiece in the radial direction, that is, the back component force 30 that pushes the flat die perpendicular to the bottom surface.

  As shown in FIG. 9, the flat dies 5 and 6 are fixed to the table 19 via a pair of wedge-shaped members 7 and 8, and one wedge member 8 is rotated by rotating a ball screw 9 by a servo motor 10. It can be moved in the vertical direction 11. That is, for example, by giving a predetermined rotation command to the servo motor by an NC command, the wedge member 8 is moved up and down by a predetermined amount, and the flat dies 5 and 6 are accurately moved in the horizontal direction 12 through the wedge surface as shown in the figure. Let Thereby, the distance between dice | dies can be controlled. Thereby, the target value of the OPD dimension of the spline can be changed.

  As shown in FIG. 8, a strain sensor 25 is attached to the front panel 26 of the rolling machine 11 so that the strain generated by pulling in the left and right 30, 31 directions can be detected by the back component force during processing. Has been. The output of this strain sensor is proportional to the back component force.

  FIG. 10 is a characteristic diagram showing the relationship between the back component force (distortion sensor output) of the pre-rolling process and the overpin diameter size of the post-rolling process. The relationship between the strain sensor output and the overpin diameter when the workpiece is continuously processed is shown. As shown in FIG. 10, when the OPD dimension at the strain sensor output a is set to a target dimension (specified dimension), the OPD dimension increases (Δd) almost in proportion to the increase in back force (ΔV). It can be seen that the OPD dimension of the workpiece and the back component force are in a substantially linear relationship. This is because the OPD of the workpiece is determined by the size of the workpiece and flat dies during the rolling process, and the amount of return of elastic deformation of the rolling machine (spring back amount), but the spring back amount is the back component force during the rolling process. It is thought that it is proportional to

  From the above, if the strain sensor output during the pre-rolling process is measured and the difference from the specified value is known, the difference from the target value of the OPD dimension can be understood. That is, the OPD dimension value to be corrected at the time of post-rolling can be obtained.

  Based on this consideration, using the relationship between strain sensor output and OPD dimensions obtained in FIG. 10, when the back force during rolling changes due to workpiece hardness variation within the lot, etc. Describes how to stabilize and stabilize the OPD dimensions of the workpiece.

  FIG. 11 is a front view showing a rolling process step according to the second embodiment of the present invention, in which (a) starts the pre-rolling process, (b) completes the pre-rolling process, (c) returns the process, (D) shows a post-rolling processing completion position. As shown in FIG. 11A, the left die 5 moves downward and the right die 6 moves upward as viewed in the figure, and temporarily stops near the end of the finish tooth portion 2 shown in FIG. 11B. At this time, the back force generated in the finished tooth portion is acquired by the strain sensor 25. Here, the OPD dimension (Δd) to be corrected is calculated from the relationship of FIG. 10 from the difference (ΔV) between the strain sensor output value and the specified value.

  Next, the left and right dies 5 and 6 are retracted to the position shown in FIG. At this position, the workpiece and the die are slightly evacuated. Here, the right and left dies are added to a predetermined additional amount, and an amount ½ of the OPD dimension (Δd) to be corrected is further driven. Further, the die is advanced again, and the rolling process is completed in the state shown in FIG. At this time, the OPD dimension of the processed workpiece has a small variation even when the hardness of the workpiece in the lot varies, and is a stable processing dimension.

  In the second embodiment, after moving the flat die for one direction twice and performing the pre-rolling process for measuring the back force, the die is returned and the distance between the die is shortened to finish. The rolling process was post-rolled to improve accuracy. Similarly, the present invention can also be applied to the case of reciprocating rolling while the distance between the dies is sequentially approached as in Patent Document 4 or Patent Document 5 described above. In this case, the post-rolling process is set as the final finish dimension, the pre-rolling process is set as the immediately preceding process, the back component force is measured, and the final finish dimension is corrected according to the back component force. Furthermore, as in Patent Document 3, when rolling a plurality of rolling dies one after another, the subsequent rolling process is performed with the final finishing die, and the pre-rolling process is performed with the immediately preceding die, The back component force is measured, and the final finish dimension may be corrected according to the back component force. As described above, the present invention can be appropriately applied to the conventional reciprocating rolling process and the multi-rotating process.

  Although the flat die and the flat die type rolling machine have been described, it goes without saying that the same processing is possible in the case of the rotating (round) die and the rotating die type rolling machine as in Patent Document 2 described above. Absent. In this case, pre-rolling is performed at an inter-axis distance larger than the distance between the rotary die axes at the final finishing dimension, and the back component force is measured at the same time. The distance between the rotary die axes at the time of final finishing may be corrected according to this back component force, and post-rolling may be performed to perform finish rolling. Since others are the same as in the prior art, a detailed description is omitted.

  As described above, multiple rotation forming is performed, and finish rolling dimensions are corrected in post-rolling processing according to the back component force in the front rolling processing, so involute splines etc. by increasing workpiece hardness It is possible to suppress an increase in the overpin diameter size, suppress a dimensional change, and form a highly accurate tooth. The distance between the pair of flat dies may be appropriately selected and set by the NC program or the like, such as the distance between the pitch lines of the flat dies, the distance between overpins, or the distance between the moving table surfaces to which the pair of flat dies are attached. .

4 Workpieces 5, 6, 22, 24 (Flat) Dies 21, 23 (For screw machining) Dies 11, 16 Rolling machine c Shaft center ΔV Back component force (Strain sensor output)

Claims (4)

A workpiece which is rotatably supported on the axis, a pair of dies disposed on the axis of symmetry, a strain sensor for detecting the back component force during rolling of the workpiece, a rolling machine equipped with Using a rolling method for controlling the distance between the pair of dies to be constant, and rolling the workpiece outer peripheral surface by moving the workpieces in opposite directions while sandwiching the workpiece, Measured by rolling a plurality of different workpieces at a pre-rolling processing command distance in which the distance between the pair of dies was set in advance for the workpiece specifications and the preceding rolling processing command distance with respect to the workpiece specifications. A post-rolling processing command distance in which a distance between the pair of dies is determined in advance as a function of a back component force, and a distance between the pair of dies is set as the front rolling processing command distance to set the workpiece Before rolling and during the previous rolling process The back component force is measured, the post-rolling processing command distance is obtained from the measured back component force by the function, and the distance between the pair of dies is set to the calculated post-rolling processing command distance. Is a rolling method for post-rolling , wherein the pre-rolling process is a process of performing thread rolling on the workpiece by using a flat die for thread rolling, and the post-rolling process is By using a flat die for an involute spline, the workpiece is processed in the pre-rolling process by performing involute spline rolling on the work, and the workpiece is processed in the post-rolling process. The workpiece is different from the axial direction of the workpiece and is processed while measuring the back component force of the workpiece using the strain sensor during the forward rolling process, and according to the back component force during the subsequent rolling process. The word Rolling method characterized in that for machining to correct the over-pin diameter involute splines. The post-rolling process is a process of performing involute spline rolling on the workpiece by using a flat die for involute spline, and the tooth traces are parallel to the axis of the workpiece, or are indented or helical. The rolling method according to claim 1, which is a tooth-shaped rolling process. The rolling process method according to claim 1, wherein the post-rolling process command distance is smaller than the pre-rolling process command distance . The pair of dies are rotary dies that can be rotated symmetrically about the axis, and the distance between the pair of dies is a distance between the rotation axes of the pair of dies. The rolling method according to claim 1 .

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