JPH10109134A - Spiral shaft by cold forging, its manufacture and die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrally form a spiral line simply and rapidly and to improve the wear resistance in each part of an outer wall by executing cold high-speed striking of a bar-shaped or tubular metallic base stock. SOLUTION: A stainless steel tube 1 having the outside diameter of 38mm and length of 4000mm, for example, is charged in a swaging machine 2 and a spiral shaft having the outside diameter of a core tube of 27mm, the height of the spiral projected line of 7mm and the pitch of 50mm is formed at 4m/min. At this time, the spiral line is formed on the outer peripheral wall of the metallic base stock by the high-speed striking. Next, by passing the base stock through a heat treating furnace 4 whose atmosphere temp. is 650 deg.C for 5min and rapidly cooling it by blowing cold wind, the spiral shaft 3a having surface hardness RB 106 is manufactured. In accordance with material and application, there are instances where heat treatment for surface hardening is not executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cold forging for forming a spiral strip (projection or groove) integrally on the outer peripheral wall of a metal tube or a metal rod (solid) by cold forging. The present invention relates to a spiral shaft, a method for manufacturing the same, and a mold used for the same.

[0002]

2. Description of the Related Art A conventionally known spiral shaft winds a spiral forming material (a band material, a rod material, etc.) around an outer peripheral wall of a rod core material, and welds and fixes the rod core material to the spiral forming material. In addition, the outer wall of the rod core is cut to form a spiral ridge, or a forming means such as hot rolling has been employed. Also known is a method of cold forging a spiral forming material and fixing it to a shaft (Japanese Patent Laid-Open No. Sho 4).
No. 9-14333).

[0003]

The method of welding a spiral forming material has a characteristic that the width of a spiral blade can be freely selected, but can withstand severe use in strength (for example, an underground drill). Problems such as breakage or breakage, and low durability due to abrasion.

[0004] Next, the method of cutting a spiral ridge from a rod core material requires not only a long processing time, but also a restriction on the material for improving the free-cutting property, and a method for hardening. Heat treatment is required, and furthermore, the metal fibers are cut by cutting, so that the strength is inevitably reduced. Therefore, the spiral portion must be thickened to have the necessary strength. In short, there are problems that the number of processing steps, time, material amount, and the like are remarkably increased, and that cutting chips are also increased.

[0005] Furthermore, since hot rolling is based on processing during heating, a constant high temperature must be maintained during processing.
There are a number of problems, such as the material and processing equipment being severely restricted and equipment for maintaining the entire material at a predetermined temperature is required. In addition, the method of fixing the spiral forming material manufactured in advance to the shaft has a problem that not only does the automation of the manufacturing process become difficult, but also the fixing of the spiral forming material becomes difficult.

[0006]

SUMMARY OF THE INVENTION However, the present invention provides a rod-shaped or tubular metal material by cold high-speed pressing.
It succeeded in forming the spiral strip easily and quickly.

That is, the invention of a spiral shaft is a spiral shaft formed by cold forging, wherein a spiral strip is formed on the outer peripheral wall of a rod-shaped or tubular metal material by high-speed pressing. A spiral shaft formed by cold forging, characterized in that a spiral strip is formed on the outer peripheral wall of a rod-shaped or tubular metal material by high-speed pressing, and the surface is hardened by heat treatment. Is a swaging process or a hosing process.

[0008] Next, the invention of the method is such that, while charging a rod-shaped or tubular metal material into a high-speed pressing machine at a predetermined speed, one or both of a mold and a metal material is rotated to form the metal material. A method of manufacturing a spiral shaft by cold forging, characterized by forming a spiral strip on the outer wall of the material, wherein a rod-shaped or tubular metal material is charged into a high-speed pressing machine at a predetermined speed, and a die is formed. Or a method of manufacturing a spiral shaft by cold forging, characterized in that one or both of the metal materials are rotated to form a spiral strip on the outer wall of the metal material, and then heat treatment is performed on a necessary portion to be hardened. It is. Furthermore, the invention of the mold is based on a plurality of split molds in which the inner diameter on the charging side of the metal material is large, the spiral forming groove for the ridge is shallow, the inner diameter on the outlet side is the product diameter and the spiral forming groove has a predetermined depth. It is a mold for forming a spiral, characterized by being constituted.

In the above invention, the spiral strip is a spiral ridge or a spiral groove, and the pitch and the height (depth) can be freely selected.

According to the present invention, there is no theoretical limitation on the diameter or length of the rod-shaped or tubular metal material which can be processed, and a product suitable for the thickness and length of the metal material to be charged can be obtained. For example, a spiral shaft having a length of several meters to several meters can be manufactured. Further, it is easy to process a metal rod or a metal tube having a diameter of several mm to several mm.

The material which can be processed by the present invention can be any metal material which can be plastically deformed by cold forging.
Conventionally, any metal material (steel material, special metal pipe, stainless steel pipe, etc.) used for the spiral shaft can be easily processed. According to the present invention, since the spiral strip is formed while pressing the surface of the metal material at a high speed, in the case of a metal material that can be hardened by work, the surface is hardened at the time of processing and may be used as a product as it is. In addition, since the surface pressing rate of the metal material becomes uneven, after the spiral strip is provided (the degree of processing is different from the core material surface and the spiral strip), heat treatment is performed on the necessary parts to make the surface hardness uniform. There is also.

The spiral shaft manufactured according to the present invention is used for a high-strength, high-strength spiral shaft such as an excavating shaft (underground).

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a spiral shaft for forming a spiral strip by cold forging a rod-like or tubular metal material by high-speed pressing, a method for producing the same, and a mold used for the same.

The metal material is a metal tube or a metal rod (or wire), and there is no machining waste. The spiral shaft may be heat-treated depending on the material to make the surface hardness uniform.

[0015]

EXAMPLE 1 A stainless steel tube 1 having an outer diameter of 38 mm and a length of 4000 mm was charged into a swaging machine 2, and an outer diameter 2 of a core tube 1a was set.
A spiral shaft 3 having a length of 7 mm, a height of a spiral ridge of 7 mm, and a pitch of 50 mm was machined at a rate of 4 m per minute. Then ambient temperature 65
After passing through the heat treatment furnace 4 at 0 ° C. for 5 minutes and blowing rapidly with cool air, a spiral shaft 3a having a surface hardness of RB106 was formed. Although the above example was heat-cured, the material,
Depending on the application, heat treatment for surface hardening may not be performed.

[0016]

Embodiment 2 An embodiment of the present invention in the case where the swaging machine 17 is used for FIGS. 2, 3, 4, and 5 will be described. The metal tube 1 is inserted as shown by the arrow 14 in FIG. 5, and the holders 6 of the molds 5 and 5 are rotated in the direction of the arrow 7. In this case, the holder 6 is formed integrally with the spindle 8, a pulley 9 is fixed to the outer end of the spindle 8, and the pulley 9 is connected to the pulley 11 of the motor 10 and the belt 1.
2 is linked. On the other hand, the metal tube 1 is not constrained in the circumferential direction and is constrained in the axial direction, and the metal tube 1 rotates with the pressing force of the die 16 formed by the dies 5 and 5. On the other hand, the metal tube 1 is rotatably supported by the support 13 and is restrained in the axial direction.
4, the metal tube 1 also moves in the same direction at the same speed. Thus, the spiral shaft 3 is formed by the rotation and advance of the metal tube 1 in combination with the pressing force of the die 16.

4A and 5, when the holder 6 rotates in the direction of arrow 7 via the spindle 8,
Since the die 16 and the backer 18 also rotate in the same direction,
The backer 18 is pressed by the pressure roll 19 in the direction of arrow 20. In this case, the backers 18 are arranged at right angles to each other, and the pressure rolls 19, 19
Since the backers 18 are arranged at equal intervals, the backers 18 are simultaneously pressed. Further, when the backer 18 and the pressure roll 19 are separated from each other, the pressing force of the mold 5 disappears, so that the metal tube 1 can be advanced in the direction of the arrow 14. At the time of actual production, the metal tube 1 is constantly urged to move forward by a predetermined pitch in the advancing direction. In this case, die 16
Is determined to be smaller than the height of the spiral ridge 15, the metal tube 1 is guided by the spiral groove 5a of the mold 5 and automatically rotates as the metal tube 1 advances. . Therefore, the metal tube 1 needs to be unconstrained in the circumferential direction.

In the above embodiment, the dies 16 are arranged in a cross shape by arranging the dies 5 and 5, and the die 16 is composed of two sets and four dies 5, 5. Although there is no numerical limitation due to the number of pieces, two or four pieces are often used in practical use.
The swaging machine 17 used in the above embodiment is one example, and various known swaging machines can be used in principle. However, a spiral groove 5a or a spiral ridge corresponding to the spiral ridge 15 is provided on the inner surface of the mold 5 so as to regulate the stroke of the die 16 and to maintain a constant relation between the advance and rotation of the metal tube 1. There is a need.

[0019]

Embodiment 3 Referring to FIGS.
A description will be given of an embodiment in which is used. In FIG. 6, four molds 23, 23 are provided at the center of the housing 22.
A pressure plate 26 having guide layers 25 is slidably in contact with a guide frame 27 attached to the inner wall of the housing 22 on the left and right sides of the die 24. On the left and right outer walls of the pressure plates 26, 26,
Pressure cylinders 29, 29 via roller bearings 28, 28
Eccentric shafts 30, 30 are inserted through the center of the pressure cylinders 29, 29, and the eccentric shafts 30, 30
Pulleys 32 and 32 are fixed to the shafts 31 and 31, and the shafts 31 and 3 are rotated by rotating the pulleys 32 and 32.
1, the eccentric shafts 30 and 30 rotate, whereby the pressurizing cylinders 29 and 29 move left and right as indicated by arrows 33 and 34. In the figure, 35 and 36 are pressure plates of the roller bearings 28 and 28, and 37 and 37 are eccentric shafts 30 and 30.
Roller bearing in contact with the outer circumference of the roller.

In the above embodiment, in FIG. 7, the metal tube 1 is inserted into the die 24 as indicated by an arrow 38, and the eccentric shafts 30, 30 are connected via pulleys 32, 32 and shafts 31, 31.
Is rotated, the pressure plates 26, 26 reciprocally slide as indicated by arrows 33, 34 with the rotation of the eccentric shafts 30, 30.
Since the metal tube 1 is not constrained in the circumferential direction and is constrained in the axial direction by the support member 39 and is constantly urged to move forward by a predetermined distance in the axial direction, the pressing force of the die 24 is eliminated and the metal tube 1 Is automatically advanced and the metal tube 1
Is rotated while moving forward while being guided by a spiral ridge 15 formed on the outer periphery thereof. In order to guide the metal tube 1 in this manner, the stroke of the die 24 needs to be equal to or less than the height of the spiral ridge 15.

[0021]

Embodiment 4 An embodiment of a mold will be described with reference to FIGS. 8 (a), 8 (b) and 8 (c). A through hole 41 is formed in the center of the mold material 40, and a spiral groove 4 having a predetermined pitch is formed in an inner wall of the through hole 41.
2 is provided. Next, a tapered hole 43 is formed concentrically with the through hole 41. This tapered hole 43 is formed as shown in FIG.
The middle and left sides have a large diameter and are approximately the same as the bottom wall of the spiral groove 42, and the right side is flush with the wall of the through hole 41.
It shall be a gentle inclination of 0 degrees or less.

If the mold is divided into 1/2 or 1/4, a die of the present invention consisting of two or four molds can be obtained.

[0023]

According to the present invention, since a rod-shaped or tubular metal material is pressed by cold forging, there is an effect that the core material and the spiral strip are integrated. In addition, since the crystal is refined by pressing and becomes uniform, and the surface is hardened by the processing, there is an effect that the wear resistance of each portion of the outer wall is improved. Further heat treatment can adjust the hardness of each portion of the outer wall of the spiral shaft.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an embodiment of the present invention.

FIG. 2 is an enlarged front view of a part of the product according to the present invention;

FIG. 3 is an enlarged front view of a partially processed intermediate product.

FIG. 4 (a) is a partial side view showing a pressing portion of a swaging machine used in the embodiment of the present invention. (B) A partially enlarged perspective view of the same mold.

FIG. 5 is a partially sectional front view of the swaging machine.

FIG. 6 is a partial sectional view of a hosing machine used for carrying out the present invention.

FIG. 7 is a cross-sectional plan view partially omitted.

FIG. 8A is a sectional view of a mold material according to the present invention. (B) Cross-sectional view similarly having a through hole. (C) Cross-sectional view similarly provided with a spiral strip. (D) Cross-sectional view similarly having a tapered hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stainless steel tube 2 Swaging machine 3 Spiral shaft 3a Spiral shaft (heat-treated) 5 Die 6 Holder 8 Spindle 10 Motor 9, 11 Pulley 12 Belt 13 Supporting device 15 Spiral ridge 16 Dice 17 Swaging machine 18 Backer 19 Pressure Roll 21 Hosing machine 22 Housing housing 23 Die 24 Die 25 Guide layer 26 Pressing plate 27 Guide frame 28, 37 Roller bearing 29 Pressing cylinder 30 Eccentric shaft 31 Shaft 32 Pulley 35, 36 Pressure plate 39 Supporting tool 40 Mold Material 41 Through hole 42 Spiral groove 43 Tapered hole

Claims (6)

[Claims] A spiral shaft formed by cold forging, wherein a spiral strip is formed on an outer peripheral wall of a rod-shaped or tubular metal material by high-speed pressing. 2. A spiral shaft formed by cold forging, characterized in that a spiral strip is formed on the outer peripheral wall of a rod-shaped or tubular metal material by high-speed pressing, and this is heat-treated to harden the surface. 3. The high-speed compression working is performed by swaging or hosing.
Spiral shaft by cold forging as described. 4. A bar-shaped or tubular metal material is charged into a high-speed pressing machine at a predetermined speed, and one or both of a mold and a metal material is rotated to form a spiral on the outer wall of the metal material. A method of manufacturing a spiral shaft by cold forging, characterized by forming a strip. 5. While loading a rod-shaped or tubular metal material into a high-speed pressing machine at a predetermined speed, one or both of a mold and a metal material are rotated to form a spiral on the outer wall of the metal material. A method of manufacturing a spiral shaft by cold forging, characterized in that a strip is formed, and then heat treatment is performed on a necessary portion to harden. 6. A plurality of split dies each having a large inner diameter on the charging side of the metal material, a shallow spiral forming groove for the ridge, a product diameter on the outlet side, and a predetermined depth of the spiral forming groove. A mold for forming a spiral, characterized in that: