JP3393822B2 - Method and apparatus for manufacturing helical rod - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive feed rod for moving a print head of a small printer, a rod for a coating device used in a device for applying a coating liquid to a continuously running strip-shaped support, and the like on the outer peripheral surface. The present invention relates to a method for manufacturing a rod with spiral ridges and a rolling apparatus for rolling the rod with spiral ridges, and particularly to a rotary machine for rolling the spiral ridge. The present invention relates to a technique for preventing scratches caused by contact with a corner of a sending side end of a rest.

[0002]

2. Description of the Related Art A long rod material is pinched between a pair of rolled round dies whose rotation axes are arranged in parallel with each other, and the rod material is driven by the rotation of the rolled round die. It is widely practiced to form a spiral ridge on the outer peripheral surface of the rod material by rotating it around the center, such as by threading. In such a rolling process, in order to prevent the rod material pinched between a pair of rolling round dies from popping out, a material supporting blade for supporting the rod material is provided, The shaft center of the rod material is provided below the straight line passing between the rotation shaft centers of. However, assuming that the position of the material support blade does not change,
When the dimension between the axis of the rod material and the straight line passing between the axes of rotation of the pair of rolled round dies becomes large, the pressing force against the material supporting blade becomes excessive, and welding or damage of the rod material may occur. Occur.

On the other hand, for example, Japanese Patent Publication No. 54-2730
As proposed in Japanese Unexamined Patent Publication No. 6 or Japanese Patent Application Laid-Open No. 7-185712, instead of the material supporting blade, a columnar member that is rotatable around an axis, that is, a rotary rest is arranged, and the rod rests by the rotary rest. By supporting the material, the cylindrical member is driven to rotate with the rotation of the rod material during the rolling process,
It is also considered to reduce the rotation resistance and friction of the rod material.

[0004]

By the way, in the conventional method for manufacturing the rod with spiral ridges or the rolling device for the rod with spiral ridges as described above, the rod is sandwiched between a pair of rolling round dies and is rotary. The rod material supported by the rest is formed by rolling while being rotated around the axis and is sent out in the longitudinal direction. There is an inconvenience that it occurs on the outer peripheral surface of the rod material pressed against the rest.

For example, as described in Japanese Patent Publication No. 4-69298, a positive feed rod for positioning a print head having a spiral screw thread having a flat top portion, and Japanese Patent Laid-Open No. 3-189039. An outer peripheral surface of a rod material such as a rod for a coating device used in a device for coating a coating liquid on a belt-shaped support as described in JP-A-5-347, JP-A-5-293580, etc. If a flat portion is provided on the top of the spiral mountain formed by rolling, the probability that a contact mark with the corner of the delivery-side end of the rotary rest, that is, a scratch, will increase at the flat portion. The above inconvenience becomes remarkable.

The present invention has been made in view of the above circumstances, and an object thereof is to rotate a rod material while pinching a long rod material between a pair of rolled round dies. To provide a method and an apparatus for manufacturing a rod with spiral ridges, which can prevent scratches due to an end portion on the delivery side of a rotary rest when a spiral ridge is rolled on the outer peripheral surface of a rod material by feeding the rod in the longitudinal direction. It is in.

[0007]

[Means for Solving the Problem] To achieve the above object, the gist of the method of the present invention is that a spiral ridge for rolling a spiral ridge on the outer peripheral surface of a rod material is provided. A method of manufacturing a rod, comprising: (a) pressing a long rod material between a pair of rolled round dies and rotationally driving the pair of rolled round dies, thereby forming the pair of rolled round dies. A feed step of feeding the rod material in the axial direction while rotating the rod material around its axis following the rotation of (b) a cylindrical support surface for supporting the rod material and a cylindrical support surface thereof. A cylindrical rotary that is provided so as to be rotatable about its axis and that is provided with a delivery-side retreat surface that is formed continuously from the delivery-side end portion and that is separated from the rod material toward the delivery-side. Using the rest, the front of the feeding process A supporting step of supporting the rod material during the rod material is sent is to contain.

[0008]

According to this structure, in the supporting step, a cylindrical supporting surface for supporting the rod material and a delivery side end portion of the cylindrical supporting surface are continuously formed on the delivery side. The rod material is fed by the feeding step by using a cylindrical rotary rest that is provided so as to be separated from the rod material as it goes toward, and is arranged so as to be rotatable about the axis. The rod material is supported while being held. Therefore, no corner is formed at the delivery side end of the rotary rest, and when the rod material is moved toward the delivery side while being rotated, it is supported by the delivery side retreat surface following the cylindrical support surface. Since it is sent out after it is delivered, scratches due to the delivery-side end of the rotary rest are preferably prevented.

[0009]

A second aspect of the present invention is to provide a rolling apparatus suitable for carrying out the method invention. The rolling apparatus is provided between a pair of rolling round dies whose rotation axes are parallel to each other. A rolling device for rolling a helical mountain on the outer peripheral surface of the rod material by rotating the rod material while feeding it in the longitudinal direction while pinching the elongated rod material, (a) A cylindrical support surface for supporting the rod material, and a delivery side retreat surface formed continuously from the delivery side end of the cylindrical support surface and further away from the rod material toward the delivery side. With a rotary rest,
(b) A support plate for supporting the rotary rest so as to be rotatable about its axis with the cylindrical support surface in contact with the rod material.

[0010]

According to this structure, the rotary rest, which is supported by the support plate so as to be rotatable about its axis in contact with the rod material, has a cylindrical support surface for supporting the rod material. And a delivery-side retreat surface formed continuously from the delivery-side end of the cylindrical support surface and further away from the rod material toward the delivery side. When it is moved toward the delivery side while being supported, it is delivered after being supported by the delivery side retreat surface following the cylindrical support surface, so that scratches due to the delivery side end of the rotary rest are preferably prevented.

[0011]

Other Embodiments of the Invention Here, preferably, the rotary rest is formed continuously from an end portion of the cylindrical support surface on the feed side, and is separated from the rod material toward the feed side. And a feeding-side retreat surface formed on the. With this configuration, since the retreating surfaces are provided at both ends of the rotary rest, it is not necessary to consider the directionality when using the rotary rest, and the usability is improved.

Further, preferably, the delivery side retreating surface provided on the rotary rest is a taper surface having a smaller diameter toward the delivery side end portion of the rotary rest, and the cylindrical support surface of the taper surface. Angle θ with respect to 0 <θ ≦ 5
It is within the range of °. With this configuration, it is possible to preferably prevent the damage caused by the sending-side end of the rotary rest. Above angle θ
Is greater than 0 °, the delivery side edge provided on the rotary rest is reliably separated from the rod material, so that there is a temporary effect of preventing scratches. The diameter of the receiving ball or the supporting shaft that rotatably supports the rest is reduced, and the receiving strength and durability are reduced.

Further, preferably, the delivery side retreat surface provided on the rotary rest has an axial length L of 2 to 10 mm, more preferably 3 to 5 mm. With this configuration, it is possible to preferably prevent the damage caused by the sending-side end of the rotary rest. When the length L in the axial direction of the delivery-side retreat surface provided on the rotary rest is less than 2 mm, it is difficult to set the delivery-side end edge provided on the rotary rest to be reliably separated from the rod material. Therefore, when it exceeds 10 mm, the length L of the delivery side retreat surface becomes unnecessarily long and the rigidity of the rotary rest decreases.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an example of a rolling apparatus capable of suitably carrying out the method of the present invention. In the figure, a pair of rolled round dies 10 and 12 are rotatably arranged around their axes with their rotation axes O1 and O2 being substantially horizontal and substantially parallel to each other. The device is driven to rotate in synchronization with each other. The rolling round dies 10 and 12 are provided with rolling processing surfaces 14 and 16 provided on the outer peripheral portion thereof, in which irregularities having a reversed shape are provided corresponding to spiral grooves or spiral ridges to be rolled. The rolling surfaces 14 and 16 are provided with a chamfered portion, a finish portion, and a relief portion, which are not shown, in order from one end in the rotation axis direction, that is, from the front side of the paper surface of FIG. The long cylindrical rod material (work) 18 to be rolled is formed in the space between the pair of rolled round dies 10 and 12 and the material support base 20 by the rotary rest 22 of the material support base 20.
Is supported in a posture substantially parallel to the rotation axis centers O1 and O2, and is forcibly fed from one end thereof in the rotation axis direction, specifically, from the front side to the back side of the paper surface.

As shown in detail in FIGS. 2 and 3, the material support base 20 has a rotary rest 22 which is, for example, a cylindrical member made of tool steel, and the rotary rest 22 is rotatable about its axis. And a holding table 26 that integrally holds the supporting plate 24 at the upper end thereof, and the axis of the rotary rest 22 is substantially parallel to the axes O1 and O2. The rod material 18 is supported in a state of being in contact with the outer peripheral surface of the rotary rest 22 in a posture substantially parallel to the axis of the rotary rest 22.

The rotary rest 22 is supported by a support plate 24 around a shaft center through a support shaft 30 penetrating the shaft center, or via receiving balls engaging with the center positions of both end surfaces. It is rotatably supported. Further, the support plate 24 is integrated with the holding table 26 by tightening the bolts 34 screwed into the holding table 26 in a state where the supporting plate 24 is fitted in the slit 32 formed in the upper portion of the holding table 26. It is designed to be attached to.

As shown in FIG. 4, the rotary rest 22 is formed by a cylindrical support surface 54 for supporting the rod material 18 and a delivery side end of the cylindrical support surface 54. And a delivery side retreat surface 56 formed so as to be more distant from the rod material 18 toward the delivery side. That is, the delivery-side retreat surface 56 provided at the delivery-side end of the rotary rest 22 is a tapered surface whose diameter decreases continuously toward the delivery-side end of the rotary rest 22, and the tapered surface has a cylindrical support. Angle θ with respect to surface 54
Is a value set within the range of 0 <θ ≦ 5 °. With this configuration, it is possible to preferably prevent the damage caused by the sending-side end of the rotary rest. If the angle θ is greater than 0 °, the delivery side end edge provided on the rotary rest is reliably separated from the rod material, so that a temporary effect of preventing scratches can be obtained, while it exceeds 5 °. As a result, the diameter of the receiving ball or the support shaft 30 that rotatably supports the rotary rest is reduced, and the receiving strength and durability are reduced. The taper angle of the tapered surface is 2θ.

The delivery side retreat surface 56 provided on the delivery side end of the rotary rest 22 has an axial length L of 2 to 10 mm, and more preferably 3 to 5 mm. When the length L of the delivery side retreat surface 56 in the axial direction is less than 2 mm, it is difficult to set the delivery side end edge provided on the rotary rest 22 so as to be reliably separated from the rod material 18, and it is 10 mm. When it exceeds, the length L of the delivery side retreat surface 56 becomes unnecessarily long and the rigidity of the rotary rest 22 decreases.

The table 28 has a plurality of guide pins 3
The pinion 40 meshed with the rack 38 is driven to rotate so that the pinion 40 is vertically moved, and the spring member 42 such as a compression coil spring always moves downward. Being energized. The pinion 40 is non-rotatably attached to a rotary shaft 46 rotatably arranged around a substantially horizontal shaft center by a support bracket (not shown) fixedly mounted on the base 44, and the rotary shaft 46 is also rotatable.
Similarly, a worm wheel 48 is attached to the wheel so that it cannot rotate relative to the worm wheel 48, and is meshed with the worm 50. The worm 50 is rotated by rotationally operating the height adjustment dial 52 disposed on the base 44, and the worm wheel 48 and the pinion 40 are rotated accordingly, so that the table 28 moves in the vertical direction. Can be moved. As a result, the height of the material support base 20, in other words, the dimension X (see FIG. 1) from the support position of the rod material 18, which is the upper end of the rotary rest 22, to the straight line L passing through the axes O1 and O2 is adjusted. It

Here, if the dimension X is sufficiently larger than the radius of the rod blank 18, as shown in FIG. 5, the rolling force Ft applied to the rod blank 18 by the two rolling round dies 10 and 12 is downward. The component force of the rod material 18 is increased by a large force corresponding to the component force of the rotary rest 22.
Pressed against. In other words, the rotary rest 22
Is pressed against the rod material 18 by the reaction force Fr of the above component force, and the spiral ridges formed by rolling on the outer peripheral surface of the rod material 18 by the both rolling round dies 10 and 12 are opposite to the rotary rest 22. It is crushed by being plastically deformed by the force Fr.
A predetermined smooth surface is formed on the top.

In that case, if the dimension X is changed by the height adjusting dial 52, the axial center Ow of the rod material 18 is changed.
To the shaft centers O1 and O2 of the rolling round dies 10 and 12 to change the rolling depth, the rotary rest 22 changes the reaction force Fr pressing the rod material 18 to change the spiral mountain. Since the amount of plastic deformation of the apex changes, the height of the spiral crest and the width of the smooth surface can be easily adjusted by changing the dimension X. Further, since the rotary rest 22 is rotated around the axis center following the rotation of the rod material 18, even if a large reaction force Fr acts between them, the friction is small, and the outer peripheral portion of the rod material 18 is welded. It is not scraped off, and the rolling rests of the rolling round dies 10 and 12 are used to smooth the tops of the spiral ridges with the rotary rest 22 while rolling with the pair of rolling round dies 10 and 12. Spiral ridges corresponding to the groove shapes formed in 14 and 16 are formed.

That is, in the rolling process, the rod material 18 to be rolled is placed between the pair of rolling round dies 10 and 12 which are rotationally driven, and the material support base 2 is provided.
While being supported in a posture substantially parallel to the rotation axis centers O1 and O2 by 0, it is fed from one end thereof in the rotation axis direction, that is, the direction from the front side to the back side of the paper surface. In this feeding step, a pair of rolling round dies 10 which are rotationally driven,
While being clamped between 12, the rolling round dies 10 and 12 are rotated around the axis Ow (see FIG. 3) in accordance with the rotation of the rolling dies, and are fed in the longitudinal direction. It is sent out in a direction to roll a spiral mountain having a desired helix angle. In addition, rod material 1 is produced by this feeding process.
8 is fed, the cylindrical support surface 54 for supporting the rod material 18 and the delivery side end of the cylindrical support surface 54 are continuously formed from the rod material 18 toward the delivery side. The rod material 18 is supported by using a cylindrical rotary rest 22 that is provided with a delivery side retreat surface 56 that is formed to retreat, that is, to be separated from each other, and that is rotatable about an axis. In this supporting step, the rod material 1 supported by the rotary rest 22
When the rotary rest 22 moves away from the delivery-side end of the rotary rest 22 as it moves in the axial direction, it passes through the delivery-side retreat surface 56 from the cylindrical support surface 54, so that the wound on the spiral peak 84 (FIG. 1).
1, FIG. 12) are preferably prevented from occurring.

FIG. 6 shows an example of a positive feed rod as a spiral threaded rod, which is rolled according to the method of the present invention using the rolling machine of FIG. Is the pitch P1 of the two spiral grooves 62 and 64, respectively.
= 15.875 mm, which are offset from each other by a half pitch, can be inserted through a through hole provided in a print head (not shown), and an engaging projection protruding on the inner surface of the through hole can be any spiral shape. The print head is linearly moved in the axial direction of the positive feed rod 60 when the positive feed rod 60 is rotationally driven around the axial center while being engaged with the groove 62 or 64. A relatively shallow auxiliary groove 66 is spirally formed between the pair of spiral grooves 62 and 64 at the same pitch P1.
In the portion between 64 and 66, a total of four spiral ridges 68 are formed due to the swelling of the surplus, and the top of the spiral ridges 68 is clear from the enlarged sectional view of FIG. 7. A flat smooth surface 70 is formed by being pressed by the rotary rest 22.

The smooth surface 70 is a portion which is slidably contacted with the inner surface of the through hole of the print head, but the smooth surface 70 is positioned on a cylindrical surface having a constant radius and covers a wide range of the inner surface of the through hole. Since the print heads are aligned, the print head can be smoothly moved in a fixed posture. Two spiral grooves 62,6
4 and the auxiliary groove 66 are formed so that they can be rolled at a good balance even if the pitch P1 is relatively large for high-speed feeding, and four spiral ridges 68 are provided to smooth the tops of the threads. This is because by forming the surface 70, the smooth surface 70 is engaged with a wide range of the inner surface of the through hole of the print head having a relatively short dimension, and the posture of the print head is stabilized.

FIG. 8 shows a rod 72 for a coating device as a spiral threaded rod manufactured according to the method of the present invention by the rolling device of FIG. 1 using SUS304 having a diameter of 12.7 mm as the rod material 18. FIG. 3 is a partial cross-sectional view showing an enlarged outer peripheral shape, which has a spiral ridge 74 with a pitch P2 = 0.2 mm, and a flat smooth surface 76 is formed on the top of the spiral ridge 74 by the rotary rest 22. Has been done. In that case, the height adjusting dial is used by using the rolling round dies 10 and 12 each having a depth of 0.0329 mm on the rolled surfaces 14 and 16 and a groove having a cross-sectional shape corresponding to the spiral ridge 74. When the dimension X was variously changed by 52 to perform the rolling process, the height H3 of the spiral ridge 74 and the width W of the smooth surface 76 were finely adjusted by changing the dimension X.

As described above, according to this embodiment, the rotary rest 2 supported by the support plate 24 so as to be rotatable about its axis while being in contact with the rod material 18.
2 is a cylindrical support surface 5 for supporting the rod material 18.
4 and the delivery-side retreat surface 56 formed continuously from the delivery-side end of the cylindrical support surface 54 and further away from the rod material 18 toward the delivery side. When 18 is moved toward the delivery side while being rotated, it is delivered after being supported by the delivery-side retreat surface 56 following the cylindrical support surface 54, so that a scratch 84 due to the delivery-side end of the rotary rest 22 is preferable. To be prevented. As a result, when the spiral threaded rod is the positive feed rod 60, the catch of the print head guided thereby is eliminated, and when the spiral threaded rod is the coating device rod 72. Thus, it is possible to prevent the coated surface from being scratched.

Further, according to the present embodiment, the delivery-side retreat surface 56 provided on the rotary rest 22 is a tapered surface having a smaller diameter toward the delivery-side end portion of the rotary rest 22, and the tapered surface Since the angle θ with respect to the cylindrical support surface is in the range of 0 <θ ≦ 5 °, scratches due to the sending-side end of the rotary rest 22 are preferably prevented.

Further, according to the present embodiment, the delivery side retreat surface 56 provided on the rotary rest 22 is 2 to 10 mm,
Furthermore, since the length L in the axial direction of 3 to 5 mm is more preferable, scratches due to the feed-side end of the rotary rest 22 are preferably prevented.

If the positive feed rod 60 is manufactured by the rolling apparatus of this embodiment, the spiral mountain 6 can be formed at the same time as the rolling process.
Since the smooth surface 70 can be formed on the apex of No. 8, high dimensional accuracy can be stably obtained as compared with the case where the smooth surface 70 is post-processed by centerless grinding and the surface roughness of the smooth surface 70 is increased. Is improved and the metal structure is dense and continuous, so that excellent wear resistance is obtained, and the manufacturing time is significantly shortened and the manufacturing cost is reduced.

When the coating device rod 72 is rolled by the rolling device of this embodiment, the height X (groove) of the spiral ridge 74 can be simply changed by changing the dimension X with the height adjusting dial 52. Since the depth H3 and the width W of the smooth surface 76 can be easily adjusted, as in the conventional case where a smooth surface is formed on the top of the spiral mountain by using a plain die or the like having a smooth outer peripheral surface, Compared with the case where various dies with different dimensions are prepared and test processing is performed while changing the setup to set the diameter dimension, the preparation time until the main processing can be significantly shortened and required for the test dies and the like. No cost is required and the manufacturing cost can be reduced.

FIG. 9 shows a state in which the rotary rest 22 of another example is rotatably supported by the support plate 24, and FIG. 10 is a front view showing the rotary rest 22. The rotary rest 22 is provided with a feed-in side retreat surface 58 which is formed continuously from the feed-side end of the cylindrical support surface 54 and is separated from the rod material 18 toward the feed-in side. . This feeding-side retreat surface 58
Also has a cylindrical support surface 54 similar to the delivery side retreat surface 56.
With respect to the angle θ and the axial length L. According to this embodiment, in addition to the effects of the above-described embodiment, the same retracted surface 56, is formed at both ends of the rotary rest 22.
Since 58 is provided, it is not necessary to consider the directionality in using it, and the effect of improving usability is obtained.

Incidentally, in the case of using the conventional rotary rest which does not have the retreating surface 56 on the delivery side, a scratch 84 as shown in FIGS. 11 and 12, for example, is a top portion of the outer peripheral surface of the rod material 18, that is, a spiral shape. It may occur on the flat smooth surface 82 that is the summit of the mountain 80. The scratches 84 are step-like contact marks and are formed during the rolling process.
This is caused by the corner of the delivery side end of the rotary rest receiving the load applied to the rod material 18 from 0 and 12. The scratches 84 are larger as the dimension X from the support position of the rod material 18 which is the upper end of the rotary rest 22 to the straight line L passing through the shaft centers O1 and O2, that is, the rotary rest 22 is the rod material 18.
It becomes more remarkable as the reaction force Fr for pressing becomes larger.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above embodiment, the delivery side retreat surface 56 formed at the delivery side end of the rotary rest 22.
Is a conical taper surface whose axial section is represented by a straight line, but it may be a curved surface whose axial section is represented by a curve, such as a partially spherical surface. In such a case, the feeding-side retreat surface 5 formed at the feeding-side end of the rotary rest 22.
8 is also a curved surface similar to the delivery side retreat surface 56.

Further, in the above-described embodiment, as the spiral threaded rod having the spiral mountain, the positive feed rod 60 having the smooth surface 70 formed at the top and the coating having the smooth surface 76 formed at the top. Although the device rod 72 has been described, the effect of the present invention can be obtained even with other rods with spiral ridges having a smooth spiral ridge at the top or rods with few smooth surfaces.

Further, in the above embodiment, the height of the rotary rest 22 is adjusted by the worm 50, the worm wheel 48, the pinion 40, and the rack 38, but other than that using a wedge member, a link mechanism, or the like. A support position adjusting mechanism can be adopted, or a motor or the like can be rotationally driven and adjusted by a switch operation. Further, instead of the support position adjusting mechanism capable of adjusting the height of the rotary rest 22 as described above, a support mechanism having a fixed height may be used.

Although not illustrated one by one, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a front view illustrating an example of a rolling device capable of suitably implementing the method of the present invention.

FIG. 2 is a cross-sectional view showing a height adjusting mechanism portion of a rotary rest in the rolling device of FIG.

3 is an enlarged perspective view showing a support state of a rotary rest used in the rolling device of FIG. 1 by a support plate.

4 is an enlarged front view showing a rotary rest used in the rolling device of FIG. 1. FIG.

FIG. 5 is a diagram illustrating a reaction force applied from a rotary rest to a rod material in the rolling device of FIG.

6 is a front view showing an example of a positive feed rod manufactured according to the method of the present invention using the rolling apparatus of FIG. 1. FIG.

7 is a cross-sectional view showing the vicinity of an outer peripheral portion of the positive feed rod of FIG. 6 in a partially enlarged manner.

FIG. 8 is a cross-sectional view partially enlarged in the vicinity of the outer peripheral portion of a rod for a coating apparatus manufactured according to the method of the present invention using the rolling apparatus of FIG.

FIG. 9 is an enlarged perspective view showing a state where a rotary rest is supported by a support plate according to another embodiment of the present invention, and is a view corresponding to FIG. 3.

10 is an enlarged front view of the rotary rest of FIG. 9, corresponding to FIG.

FIG. 11 is a cross-sectional view showing scratches that occur when rolling is performed using a conventional rotary rest that does not have a delivery side retreat surface.

12 is a plan view showing the scratch of FIG. 11. FIG.

[Explanation of symbols]

10, 12: Rolled round die 18: Rod material 22: Rotary rest 54: Cylindrical support surface 56: Sending side retreat surface 60: Positive feed rod (rod with spiral mountain) 68,74: spiral mountain 70, 76: smooth surface 72: Rod for coating device (rod with spiral mountain)

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B21H 3/00 B21H 3/04 B21H 9/00

Claims (2)

(57) [Claims] 1. A method for manufacturing a rod with spiral ridges for rolling a spiral ridge on the outer peripheral surface of a rod material, wherein a long rod material is sandwiched between a pair of rolled round dies. With the rotational driving of the pair of rolling round dies together, a feeding step of following the rotation of the pair of rolling round dies to feed the rod material in the axial direction while rotating the rod material around its axis, A cylindrical support surface for supporting the rod material, and a delivery side retreat surface formed continuously from the delivery side end of the cylindrical support surface and further away from the rod material toward the delivery side. And a supporting step of supporting the rod material while the rod material is fed by the feeding step, using a cylindrical rotary rest arranged so as to be rotatable about an axis. With a spiral mountain The method of production. 2. An outer peripheral surface of the rod material by rotating the rod material and feeding it in the longitudinal direction while pressing the longitudinal rod material between a pair of rolled round dies whose rotation axes are parallel to each other. A rolling device for rolling a spiral mountain to a cylindrical support surface for supporting the rod material and a delivery side formed continuously from a delivery side end of the cylindrical support surface. The rotary rest having a delivery side receding surface formed so as to be separated from the rod material toward the rod material, and rotation of the rotary rest about its axis with the cylindrical support surface contacting the rod material. And a support plate for supporting the support member so as to support the rod.