JPH0716748B2 - Taper thread rolling method for pipe materials - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for rolling a taper screw for a pipe material formed in, for example, a gas pipe or a pipe joint.

[Prior art and problems]

Generally, there are a cutting process and a plastic process as a method of forming a taper screw at an end of a pipe material.

Since the thread is formed by cutting the thick part of the pipe into a taper shape by lathe etc., the useful wall thickness of the thread groove bottom is much simpler than the wall thickness of the non-cut part in terms of mechanical strength. As a result, the pipe becomes thin, and there is a problem in strength or corrosion resistance of the pipe.

On the other hand, in the plastic working, the end of the pipe material is plastically deformed in advance to taper gradient of a desired taper screw by another mechanism, and then the taper screw is formed by a rolling roller having a screw thread. The thread rolling machine, which has a large number of processes and has both a drawing mechanism and a thread rolling mechanism, has a complicated structure and becomes large in size, and it is not easy to handle under work conditions where relocation is frequently performed, such as gas piping work. It was

In view of the present situation, the present invention provides a taper thread rolling method for pipe materials, which can simplify and downsize the mechanism of the rolling machine itself, which is expected to have a small number of steps in plastic working.

[Means for solving problems]

According to the present invention, in order to solve the above problems, a method of rolling a taper screw on an end portion of a pipe material, each having a taper peripheral surface portion equal to a desired taper gradient, and an effective diameter of a desired screw A plurality of rolling forming screw parts having a lead angle substantially equal to the lead angle and a drawing forming screw part adjacent to the rolling forming screw part and having a tapered peripheral surface portion having a slope greater than the taper slope. The rolling head is rolled around the end surface of the pipe material by the rolling roller or the pipe material by relatively rotating the head having the rolling rollers arranged circumferentially and the pipe material. There is provided a taper thread rolling method for a pipe material, which is characterized by performing thread processing.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a rolling roller 10 used in a taper thread rolling method according to the present invention, wherein the roller 10 has a tapered peripheral surface portion equal to a desired taper slope, and is effective for a desired screw. A rolling forming screw portion 1 (for example, a taper peripheral surface having an angle of 1 ° 47 'with respect to the roller axis X) having a lead angle θ substantially equal to the diameter lead angle, and having a taper gradient larger than the taper gradient adjacent to the screw portion 1. Gradient taper peripheral surface (eg 8 °)
And a draw forming screw portion 3 having a. Regarding the thread shape of the draw forming screw portion 3, for example, a thread shape different from the thread 5 of the thread portion 1 (for example, a trapezoidal screw) or the same shape as in this embodiment may be used. 7 is a head 9 described later.
It is a shaft fitting hole for mounting the roller 10 in FIG.

2 and 3 are a side view and a sectional view of the cylindrical head 9 to which the rolling roller 10 described above is mounted, and a plurality (five in the figure) of the rollers 10 are fitted to the shaft 11, respectively. And are fixed in proper positions. Each shaft 11 is arranged in a shaft through hole 17 formed in the head bottom portion 9 ′ so as to surround the axis Y on the circumference of a predetermined circle a centered on the longitudinal axis Y of the head 9. Shaft 11 has circumferential grooves on both ends
After having been inserted into the through hole 17, it is fitted with the ring pin 14 so that the movement of the shaft 11 in the direction of the axis X is stopped. On the other hand, a head cover 15 is attached to the opening of the head 9, and the head cover 15 has the same number of shaft through holes 17 'as the number of shafts 11 and a tube hole for passing a molded pipe 30 (Fig. 4). 19 and are formed. Similar to the end of the shaft 11 protruding from the head bottom 9 ', the ring pin 14' is fitted into the end protruding from the head cover 15. The shaft 11 and the rolling roller 10 mounted as described above are rotatably supported by the head 9.

FIG. 4 is a side view schematically showing the taper screw rolling mechanism 20 having the head 9 shown in FIGS. 2 and 3, and the head 9 having the rolling roller 10 serves as a driving means for giving rotation. It is connected to the motor 13. Motor 13 and head 9
Is installed slidably in the axis Y direction (that is, the longitudinal direction) with respect to the base 23 of the mechanism 20 via the motor support 21.
The motor support base 21 moves on the sliding shaft 25 formed in the inside 23. The tube 30 to be molded is clamped by a holding member 27 provided on the base 23. Reference numeral 29 denotes a clamp handle for clamping the pipe 30 on the holding member 27, and the pipe 30 is clamped and fixed by being manually rotated.

Next, a taper screw rolling method using the present mechanism 20 will be described with reference to FIG. The tube 30 to be molded is inserted through the holding member 27 from the right side in the figure, and then the rolling roller
After contact with 10, the clamp handle 29 secures the longitudinal axis of the tube 30 coaxially with the motor 13 and the axis Y of the head 9. According to the present invention, the rolling roller 10 is provided with the draw forming screw portion 3 (the screw thread 5 is omitted in the drawing) having the tapered peripheral surface portion having a larger gradient than the completed taper gradient as described above. Therefore, it is not necessary for the inserted tube 30 to come into contact with the peripheral surface of the draw forming screw portion 3 and the roller end surface 31 at the contact point (that is, edge), but it is sufficient to engage on the peripheral surface of the screw portion 3.

After fixing the tube 30, the operator starts the motor 13 to rotate the head 9. With the rotation of the head 9, each shaft 11 rotatably mounted on the head 9 rotates about the axis Y, and the shaft 11 main body is also fitted to the roller.
Rotate around the shaft axis X together with 10. As described above, each roller 10 has the thread 5 (FIG. 1), so that the screw 33 is engraved one after another from the end of the tube 30.

Since the tube 30 is prevented from moving on the axis Y by the holding member 27, the head 9, the motor 13, and the motor support 21 are automatically moved to the right in the figure as the screw 33 is continuously engraved. The tip 35 of the pipe 30 is moved and eventually guided to the thread forming screw portion 1 of the rolling roller 10, and a screw having a desired taper gradient is engraved. And the end surface 35 of the tube 30 is the rolling roller.
When the end surface 34 of the threaded portion 1 of 10 is reached, the motor 13 is stopped to complete a series of taper thread rolling steps.
When the pipe 30 is removed from the main mechanism 20 after rolling, the head 9 slides leftward in the drawing by reversing the rotation of the motor 13, and the screw engagement is released. Alternatively, the clamp by the holding member 27 may be released and the tube 30 may be manually rotated and removed.

In addition, in this embodiment, the head 9 equipped with the rolling roller 10 is a tube.
It is a mechanism that moves toward 30, but separately from this
A mechanism in which 13 is fixed on the base 23 and the holding member 27 and the clamp handle 29 move leftward toward the head 9 is also possible, and the rollers 10 can be slid on the shaft 11 without being fixed. 10 may move to the right in the figure with the engraving of screws. (Fixing motor and holding member) Further, this mechanism 20 can manufacture a taper screw having a desired taper gradient, lead angle, taper peripheral surface length, and pipe tip diameter by changing the rolling roller 10. is there.

Further, in this embodiment, since the pipe material is fixed and processed, there is no rotation that draws a large arc of the pipe material as seen in other rolling machines, so that it can be sufficiently ensured in terms of safety.

〔The invention's effect〕

According to the present invention, the rolling roller is composed of a normal rolling forming screw portion having a taper peripheral surface having a desired taper gradient and a drawing forming screw portion having a larger taper gradient. (Drawing process and thread rolling process)
Since only one process is required, the manufacturing time can be shortened and the structure of the rolling machine itself can be simplified and downsized, so that it can be easily moved between construction sites.

Further, when the pipe material is set, if the pipe material comes into contact with the peripheral surface of the draw forming screw portion, it can be automatically drawn, so that the diameter of the pipe material before forming can be selected in a wide range.

[Brief description of drawings]

1 is a partial vertical cross-sectional view of a rolling roller used in the present invention; FIG. 2 is a partial vertical cross-sectional view of a head equipped with the above-mentioned rolling roller; and FIG. 3 is III in FIG. FIG. 4 is a schematic view of the taper screw rolling mechanism used in the present invention. DESCRIPTION OF SYMBOLS 1 ... Roll forming screw part, 3 ... Drawing forming screw part, 9 ... Head, 10 ... Rolling roller, 30 ... Pipe material, Y ... Head longitudinal axis line.

Claims (1)

[Claims] 1. A method of rolling a taper screw on an end portion of a pipe material, each having a taper peripheral surface portion equal to a desired taper gradient, and a lead angle substantially equal to an effective diameter lead angle of a desired screw. A plurality of rolling rollers formed by a rolling forming screw part and a drawing forming screw part adjacent to the rolling forming screw part and having a tapered peripheral surface portion having a gradient larger than the taper gradient. Characterized in that the head disposed in the above and the pipe material are relatively rotated, and the rolling roller or the pipe material is relatively moved to gradually taper draw and thread-roll from the end surface of the pipe material by the rolling roller. Tapered thread rolling method for pipe materials.