JP2005324222A - Plane die and form rolling device provided with same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plane die and a form rolling device, which sufficiently prevent the bending of an axis that is generated when forming irregularity, such as a thread, on a work by rolling. <P>SOLUTION: At the same time as thread rolling to a work 10 is started, a 1st axis part 10b of the work 10 is pressurized by bringing incompletely round cut-parts of plane dies 13, 14 into contact with the part 10b and putting the part 10b between the cut-parts. When the rotational angles of the plane dies 13, 14 becomes 135 degrees, the movement of a supporting frame 18 toward the side of the work 10 is stopped, and the 1st axis part 10b of the work 10 is pressurized by bringing completely round dwell parts of the plane dies 13, 14 into contact with the part 10b and putting the part 10b between the dwell parts. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plane die for rolling irregularities such as screws on a workpiece, and a rolling apparatus provided with the same.

  2. Description of the Related Art Conventionally, as a method for processing irregularities such as screws into a workpiece, a method by cutting and a method by rolling by plastic working are known. Among these methods, the method by rolling by plastic working is because the processing speed is fast, when high-precision rolling dies are used, the accuracy of the screw is good, the strength of the screw is increased by work hardening, etc. Mainly used.

  For example, as disclosed in Cited Document 1 or Cited Document 2, the rolling device sandwiches a work (material) to be threaded between a pair of rolled round dies, and rotates the rolled round die. The screw is formed by pressing against the work and causing plastic deformation on the work surface. Therefore, the accuracy of the formed screw is generally close to the accuracy of a rolled round die that has been ground.

  By the way, when the force acting on the workpiece at the time of thread rolling is mechanically examined, the thread of the rolling round die applies a load from both sides of the workpiece. This is considered to be that a concentrated weight is acting on each span of a continuous beam simply supported at regular intervals. Therefore, as shown in FIG. 3, particularly when the workpiece 103 has an odd number of threads, the thread of one rolling round die 101 and the thread valley of the other rolling round die 102 face each other, and the rolling A large bending moment is generated in the workpiece 103 at the ends of the round dies 101 and 102.

  Therefore, when the shaft diameter of the workpiece 103 is small and the shaft is long, the portion of the workpiece 103 that extends from the thread cut-up portion 103a to the shaft portion 103b is bent during thread rolling. As a result, when the shaft portion 103b of the workpiece 103 is supported and rotated by a bearing or the like, a shake of about 0.2 to 0.3 mm occurs. When the workpiece 103 is used as a worm, the workpiece 103 is warmed to a predetermined accuracy. Cannot be demonstrated.

Therefore, as shown in FIG. 4, when a screw is rolled onto the workpiece 103 by the rolling round dies 101 and 102, the shaft portion 103c of the workpiece 103 is sandwiched between a pair of plain dies 104 and 105 whose outer periphery is a perfect circle. A rolling device is disclosed that suppresses bending of the workpiece 103 by pressing with (for example, Patent Document 3).
Japanese Utility Model Publication No. 46-22426 Japanese Utility Model Publication No. 46-23310 JP-A-8-318340

  In the rolling apparatus described above, one plane die 104 is fixed in a direction perpendicular to the longitudinal direction of the drive shaft 106, and the other plane die 105 is movable in a direction perpendicular to the longitudinal direction of the drive shaft 107. As shown in FIG. 5A, in the state of the forward end where the movable-side plane die 105 is most advanced in the direction of the workpiece 103, the plane dies 104, 105 and the workpiece 103 come into contact with each other. The effect of suppressing bending is great. However, until the plane die 105 is in the forward end state, the gap between the plane dies 104 and 105 and the shaft portion 103c of the workpiece 103 is large as shown in FIG. Less effective. As for the worm (work 103) subjected to thread rolling in this way, a deflection of about 0.05 to 0.2 mm occurs.

  Therefore, in this rolling apparatus, there has been a problem that the bending of the shaft cannot be sufficiently prevented when a screw is rolled on the workpiece 103, and the workpiece 103 is shaken.

  The present invention has been made in view of the above circumstances, and provides a plain die that can sufficiently prevent bending of a shaft that occurs when rolling irregularities such as screws on a workpiece, and a rolling device including the plane die. The purpose is to do.

In order to achieve the above object, the rolling device of the present invention comprises:
The plurality of rolling round dies are rotated while driving the plurality of rolling round dies through the plurality of driving shafts by sandwiching a workpiece between the plurality of rolling round dies fixed to the plurality of driving shafts, respectively. A rolling device that presses against the workpiece to form irregularities on the outer periphery of the workpiece,
Each of the plurality of drive shafts is fixed and provided with a plurality of plane dies.
During the rolling forming, each of the plane dies sandwiches the shaft portion of the workpiece, and the distance between the center of the workpiece and the outer peripheral surface of the plane die is constant.

  Further, during the rolling formation of the workpiece, a part of the cross-sectional shape of each plane die is formed by a curved surface in which the distance between the center of the workpiece and the outer peripheral surface of each plane die is constant. It is characterized by.

  In addition, a part of the cross-sectional shape of each of the plane dies is a non-circular shape.

The plane die of the present invention is
A plurality of plane dies fixed to a rotation drive shaft together with a plurality of rolling round dies that roll and form irregularities on the outer periphery of the workpiece by being pressed against the workpiece while being driven to rotate while sandwiching the workpiece. ,
During the rolling formation of the workpiece, the shaft portion of the workpiece is sandwiched, and the distance between the outer peripheral surface and the center of the workpiece is constant.

  In addition, a part of the cross-sectional shape is formed by a curved surface in which the distance between the outer peripheral surface and the center of the workpiece is constant during the rolling formation of the workpiece.

  In addition, a part of the cross-sectional shape is a non-circular shape.

  According to the present invention, it is possible to provide a plain die that can sufficiently prevent the bending of the shaft that occurs when rolling irregularities such as screws on a workpiece, and a rolling device including the same.

  A rolling apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the rolling device 1 includes a pair of rolled round dies 11, 12, a pair of opposed facing dies 13, 14, one rolled round die 11, and one plane. The drive shafts 15 and 16 in which the die 13, the other rolled round die 12 and the other plane die 14 are fixed coaxially, and the support frames 17 and 18 which rotatably support the drive shafts 15 and 16, respectively. And a bush 19 that rotatably holds the workpiece 10.

  Further, as shown in FIG. 1, the rolling device 1 enables the servomotors 20 and 21 that respectively drive the drive shafts 15 and 16 and the support frame 18 to move in a direction perpendicular to the longitudinal direction of the drive shaft 16. A servo motor 22, a position sensor 23 for detecting the position of the support frame 18, angle sensors 24 and 25 for detecting the rotation angles of the drive shafts 15 and 16, and an NC controller (not shown) are provided. The NC control device has a function of rotating the servo motors 20 and 21 synchronously in the same direction, and a function of adjusting the distance between the drive shafts 15 and 16 by driving the servo motor 22 and moving the support frame 18. .

  The workpiece 10 is a worm shaft, and includes a screw portion 10a, a first shaft portion 10b, a second shaft portion 10c, and rounded-up portions 10d and 10e. The workpiece 10 in FIG. 1 represents the workpiece 10 after thread rolling, and before the thread rolling, the screw portion 10a is a thread rolling molded portion 10a in which no screw is formed.

  The pair of rolling round dies 11 and 12 are rotationally driven in the same direction and at the same speed, and the workpiece 10 is plastically deformed by pressurizing the thread rolling formed portion 10a of the workpiece 10 between the screw dies. Part 10a is formed. The pair of rolling round dies 11 and 12 are round dies having the same shape, and are constituted by cylindrical members having holes 11d and 12d (FIG. 2) into which the drive shafts 15 and 16 are inserted in the center. Yes. On the outer peripheral surfaces of the rolling round dies 11, 12, threaded threads 11a, 12a are formed. The rolling round dies 11 and 12 are fixed to the drive shafts 15 and 16 by keys 31 and 32 (FIG. 2), respectively.

  The pair of plane dies 13 and 14 are rotationally driven at the same speed in the same direction (counterclockwise direction in FIG. 2), and pressurize the workpiece 10 by sandwiching the first shaft portion 10b of the workpiece 10 therebetween. Prevent bending of the shaft. As shown in FIG. 2, the pair of plane dies 13 and 14 are dies having the same shape, and are constituted by substantially columnar members having holes 13 d and 14 d into which the drive shafts 15 and 16 are inserted in the center. ing. The plane dies 13 and 14 are fixed to the drive shafts 15 and 16 by keys 31 and 32, respectively. The plane dies 13 and 14 are made of, for example, die steel, and the surface thereof is quenched and hardened.

  The outer peripheral surfaces of the plane dies 13 and 14 are formed flat in the longitudinal direction of the drive shafts 15 and 16, respectively. As shown in FIG. 2, the cross-sectional shapes of the outer peripheral surfaces of the plane dies 13 and 14 are formed of cut portions 13a and 14a, dwell portions 13b and 14b, and connecting portions 13c and 14c, respectively. With the plane die 13 and 14 as the reference (rotation angle 0 degree (360 degrees)) where the first contact portion of the workpiece 10 is first contacted with the first shaft portion 10b, the rotation angle of the plane dice 13 and 14 is 0 to 135 degrees. Degree portions constitute the cut portions 13a and 14a, portions where the rotation angle is 135 degrees to 180 degrees constitute the dwell portions 13b and 14b, and portions where the rotation angle ranges from 180 degrees to 360 degrees constitute the coupling portions 13c and 14c.

  The thread rolling of the workpiece 10 is performed until the rotation angle of the plane dies 13 and 14 becomes from 0 degree to just before 180 degrees. While the workpiece 10 is being rolled, the cut portions 13a and 14a and the dwell portions 13b and 14b of the plane dies 13 and 14 are always in contact with the first shaft portion 10b of the workpiece 10. That is, the distance between the outer peripheral surface of each of the plane dies 13 and 14 and the center of the workpiece 10 is constant while the workpiece 10 is being thread-rolled. When the plane dies 13 and 14 are rotated until the rotation angle is just before 180 degrees, the plane dies 14 are retracted from the workpiece 10 via the support frame 18.

  The notches 13a and 14a have a non-circular shape (cam shape) corresponding to a change in the distance between the drive shafts 15 and 16. That is, the distance between the drive shafts 15 and 16 decreases as the thread rolling to the workpiece 10 by the rolling round dies 11 and 12 proceeds. The diameter r of the cut portions 13a and 14a of the plane dies 13 and 14 is made to be a curved surface that decreases as the rotation angle increases. In this way, the distance between the outer peripheral surface of each of the plane dies 13 and 14 and the center of the workpiece 10 is constant, and the state where the cut portions 13a and 14a and the first shaft portion 10b of the workpiece 10 are in contact with each other is maintained. be able to.

  The dwell portions 13b and 14b are formed of a part of a perfect circle shape. When the rotation angle of the plane dies 13 and 14 reaches 135 degrees, the movable plane die 14 via the support frame 18 is in the forward end state, and is closest to the workpiece 10 and stops. Therefore, since the distance between the drive shafts 15 and 16 is constant, the dwell portions 13b and 14b and the first shaft portion 10b of the workpiece 10 are in contact with each other even if the diameter r of the dwell portions 13b and 14b is constant. Can keep the state.

  The connecting portions 13c and 14c have a curved shape that connects the cut portions 13a and 14a and the dwell portions 13b and 14b. The connecting portions 13c and 14c are not used for rolling.

Next, a method for rolling a screw on the workpiece 10 using the rolling device of the present embodiment will be described.
First, the work 10 is held by the bush 19. The drive shafts 15 and 16 are fitted with the holes 11 d and 12 d of the rolling dies 11 and 12 and the holes 13 d and 14 d of the plain dies 13 and 14. With the keys 31 and 32 provided on the drive shafts 15 and 16, the rolling round dies 11 and 12 and the plane dies 13 and 14 are attached to the drive shafts 15 and 16 so as not to rotate.

  Then, the rolling device is operated. The NC control device of the rolling device drives the servo motors 20 and 21 to rotate the drive shafts 15 and 16 at a predetermined rotational speed. The NC control device drives the servo motor 22 by numerical control referring to the position information of the drive shaft 16 given from the position sensor 23, and moves the support frame 18 closer to the workpiece 10 by a predetermined distance.

  The NC control device of the rolling device detects the rotation angles of the rolling round dies 11 and 12 and the plain dies 13 and 14 based on the rotation angles of the drive shafts 15 and 16 given from the angle sensors 24 and 25. When the NC control device detects that the cut portion 13a of the plane die 13 and the cut portion 14a of the plane die 14 face each other from the rotation angle, the NC control device drives the servo motor 22 to move the support frame 18 to the workpiece. Move further to 10 side. The rolling round dies 11 and 12 start screw rolling while pressing the workpiece 10 with the thread rolling forming portion 10a of the workpiece 10 while rotating the workpiece 10, and at the same time, the cutting portions 13a of the plain dies 13 and 14 are started. , 14a are in contact with the first shaft portion 10b of the workpiece 10 and pressurize by sandwiching the first shaft portion 10b.

  When the rotation angle of the plane dies 13 and 14 reaches 135 degrees, the NC control device stops the movement of the support frame 18 toward the workpiece 10, so that the dwell portions 13 b and 14 b of the plane dies 13 and 14 become the first of the workpiece 10. While being in contact with the single shaft portion 10b and being pressed, pressurization is performed, and the thread rolling forming portion 10a of the workpiece 10 is subjected to a thread rolling finishing process or the like by the rolling round dies 11, 12.

  Then, when the rotation angle of the plane dies 13 and 14 is just before 180 degrees, the NC control device drives the servo motor 22 to move the support frame 18 to the opposite side to the workpiece 10 side and return it to the original position. . Thereby, the rolling round dies 11 and 12 and the plane dies 13 and 14 are completely separated from the work 10, and the threaded portion 10a is formed in the work 10, and the thread rolling to the work 10 is finished. The NC control device stops the servo motors 20 and 21 and stops the servo motor 22.

  As described above, in the rolling device of the present embodiment, during the thread rolling process of the workpiece 10, the plane dies 13, 14 and the first shaft portion 10b of the workpiece 10 are always brought into contact with each other so as to be sandwiched and pressurized. Therefore, a large bending moment is not generated on the axis of the workpiece 10, and the bending of the axis of the workpiece 10 can be sufficiently prevented. Further, the accuracy of the entire worm shaft (work 10) is further improved, and the length accuracy of the first shaft portion 10b and the second shaft portion 10c of the worm shaft (work 10) is also improved.

  While the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above-described embodiment, the example in which the workpiece 10 is a worm shaft has been described. However, the workpiece 10 is pressed by the rolling round dies 11 and 12 so that the thread of the rolling round dies 11 and 12 is applied to the surface. Any thread can be used as long as the thread valley corresponding to the ridge is rolled, and the present invention is effective for such rolling in general. That is, in the above embodiment, an example in which a screw is rolled on the workpiece 10 has been described. However, the irregularities formed by rolling on the workpiece 10 are not limited to screws, and include irregularities such as knurling, serration, forming, and worm. It is.

  Moreover, although the example of the rolling apparatus provided with the two drive shafts 15 and 16 has been described in the above embodiment, the number of drive shafts is not limited to two, and any number of rolling round dies and plane dies can be used. It can be attached to the drive shaft.

  Further, in the above embodiment, in the cross-sectional shape of the plane dies 13 and 14, the portions where the rotation angle is 0 to 135 degrees are the cut portions 13a and 14a, and the portions where the rotation angle is 135 to 180 degrees are the dwell portions 13b, Although 14b and the part of 180 to 360 degrees have been described as the connecting portions 13c and 14c, the cut portions 13a and 14a, the dwell portions 13b and 14b, and the like according to the size and shape of the workpiece 10 and the like. The distribution of the connecting portions 13c and 14c can be arbitrarily set.

  Moreover, although the said embodiment demonstrated the example provided with a pair of plane dies 13,14 and a pair of rolling round dies 11,12, the number of plane dies or rolling round dies is three or more. Also good.

  In the above embodiment, the rolling device having the numerical control device has been described. However, the rolling device having no numerical control device is also effective.

  Moreover, although the example which hold | maintains the workpiece | work 10 with the bush 19 was demonstrated in the said embodiment, you may make it hold | maintain both ends of the workpiece | work 10 with a pair of center.

It is a top view showing a schematic structure of a rolling device concerning an embodiment of the invention. It is the figure which showed schematic structure of the plane die periphery with which the rolling apparatus of FIG. 1 was equipped. It is the figure which showed a mode that the screw was rolled and formed in the workpiece | work in which the conventional screw is an odd number. It is a figure showing schematic structure of the conventional rolling apparatus. It is the figure which showed a mode that the screw was formed in a workpiece | work by the conventional rolling apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling apparatus 10 Work 10a Thread part (screw rolling molding part)
10b First shaft portion 11, 12 Rolled round dies 13, 14 Plain dies 13a, 14a Cut portions 13b, 14b Dwell portions 13c, 14c Connection portions 15, 16 Drive shafts 17, 18 Support frame

Claims (6)

The plurality of rolling round dies are rotated while driving the plurality of rolling round dies through the plurality of driving shafts by sandwiching a workpiece between the plurality of rolling round dies fixed to the plurality of driving shafts, respectively. A rolling device that presses against the workpiece to form irregularities on the outer periphery of the workpiece,
Each of the plurality of drive shafts is fixed and provided with a plurality of plane dies.
The rolling apparatus characterized in that, during rolling forming, each of the plane dies sandwiches the shaft portion of the workpiece, and the distance between the center of the workpiece and the outer peripheral surface of the plane die is constant.   During rolling forming of the workpiece, a part of the cross-sectional shape of each plane die is formed by a curved surface in which the distance between the center of the workpiece and the outer peripheral surface of each plane die is constant. The rolling device according to claim 1.   The rolling device according to claim 2, wherein a part of a cross-sectional shape of each of the plane dies is formed into a non-circular shape. A plurality of plane dies fixed to a rotation drive shaft together with a plurality of rolling round dies that roll and form irregularities on the outer periphery of the workpiece by being pressed against the workpiece while being driven to rotate while sandwiching the workpiece. ,
A plane die characterized by sandwiching a shaft portion of the workpiece during rolling forming of the workpiece and having a constant distance between the outer peripheral surface and the center of the workpiece.   5. The plane according to claim 4, wherein a part of the cross-sectional shape is formed by a curved surface in which a distance between the outer peripheral surface and the center of the workpiece is constant during the rolling formation of the workpiece. dice.   6. The plane die according to claim 5, wherein a part of the cross-sectional shape is a non-circular shape.

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