JPH0469012B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tube straightening device characterized in that it includes a mechanism for straightening the roundness of a tube to be processed and a mechanism for straightening a tube bend.

(Prior art) Steel pipes, etc., which are welded with a circular cross-section of strips, must be expanded to ensure the roundness of the pipe. To explain an example, as shown in Fig. 3A and B, pull rod 1, pull rod 1
A truncated pyramid-shaped cone 2 is fitted to the tip of the cone 2, a plurality of segments 3 are arranged on the polygonal outer peripheral surface of the cone 2, and a plurality of segments 3 are fitted to the base side of the pull rod 1 so as to be relatively slidable. When the expander 10 is disposed in the processing section of the pipe a to be processed as shown in the figure and the pull rod 1 is pulled in the direction of the arrow, the locking section is formed. The cone 2 is moved in the same direction via the tube 1a, and the 3 groups of segments whose lateral movement is prevented by the support cylinder 4 are moved radially outward to apply radial correction to the inner wall of the processing section of the pipe to be processed a. It is configured as a mechanical expander 10 that applies pressure to expand the pipe a to be processed to give it roundness.

(Problems with the prior art) In the mechanical expander, the fourth
Longitudinal weld bead a1 as shown in Figures A and B
When a welded pipe a is straightened, the welded pipe a
Generally, since there is a tube bend d in the longitudinal direction, there are problems such as the tube bend d deteriorates the roundness correction performance and the tube bend d cannot be corrected sufficiently.

(Objective of the Invention, Means for Solving Problems) The present invention has been developed to solve the above-mentioned problems. It is characterized by a structure comprising an expander that applies straightening pressure in the radial direction to the tube, and a tube bending straightening device that applies a bending moment for straightening the tube bending from the outside of the tube to be processed, simultaneously with the straightening pressure processing of the expander. , by placing an expander inside the pipe to be processed and applying radial straightening pressure to the inner wall of the processed part, and simultaneously applying a bending moment for straightening the pipe bending from the outside of the pipe to be processed by a pipe bending straightening device, The straightening pressure in the radial direction and the bending moment for straightening the pipe bend can significantly improve both the roundness and the straightening performance of the pipe bend, and the wall thickness can also be adjusted, as described above. The object of the present invention is to provide a tube straightening device that solves the problems of the conventional art.

(Embodiment of the invention) An embodiment of the invention is shown in FIGS. 1A and 1B,
In the figure, 1 is a pull rod, 2 is a truncated pyramidal cone fitted into the pull rod 1, 3 is a plurality of segments arranged on the polygonal outer circumferential surface of the cone 2, and 4 is relative to the base side of the pull rod 1. It is a support cylinder for segments 3 that are movably fitted into the cone 2 and whose movement is prevented by an appropriate member not shown, and the 3 groups of segments are supported on the polygonal outer circumferential surface of the cone 2 to be machined. It is arranged so that it comes into contact with almost the entire inner surface of the processed part of the pipe a, and as shown in FIG. When we add P,
The cone 2 is moved in the same direction via the locking portion 1a, and the three groups of segments whose lateral movement is prevented by the support cylinder 4 are moved radially outward by the polygonal outer peripheral surface of the cone 2. The expander is configured as a mechanical expander that can apply straightening pressure in the radial direction to almost the entire inner wall of the processing portion of the pipe a to be processed.

Furthermore, in the present invention, a pair of support rolls 11a and 11b are provided at an appropriate interval on the lower side of the processed pipe a where the mechanical expander 10 is provided, and 1 arranged at appropriate intervals above the processing section
A pair of presser rolls 12a, 12b are provided, the lower side of the tube to be processed a is supported by the support rolls 11a, 11b, and the upper side of the tube to be processed a is supported by the presser rolls 12a, 12b in the direction of the arrow. The structure is such that a tube bending straightening device is installed which applies a load and a bending moment for straightening the tube bending from the outside of the tube a to be processed.

Note that the pipe bend straightening device shown in Fig. 1 has a convex roller on the lower side that straightens the pipe bend, and serves as a loading means, but it is possible to change the arrangement relationship between the support roller and the presser roller or the load position. It is also possible to adopt a structure in which the upwardly convex pipe bend is corrected by means such as the above.

(Function) Since the embodiment of the present invention shown in FIGS. 1A and 1B has the above-described configuration, the mechanical expander 10 is arranged as shown in FIGS. When a pulling force P is applied to the pull rod 1 to the right in the figure and it is pulled, the cone 2 moves to the right in the figure along with the pull rod 1, and the group of segments 3 is moved radially outward, so that almost the entire inner wall of the pipe to be processed a is covered with it. It is possible to apply straightening pressure in the radial direction over the entire length of the pipe a, thereby correcting the roundness of the pipe a to be processed.

In addition, when loads W and W are applied in the direction of the arrow to the presser rolls 12a and 12b of the pipe bending straightening device at the same time as the straightening pressure is applied by the mechanical expander 10, it is possible to straighten the pipe from the outside of the pipe a to be processed. A moment can be applied, and the straightness of the tube can be corrected as well as the roundness correction described above.

FIG. 1A shows the straightening state of a pipe a to be processed which has a convex pipe bend on the lower side, and by the straightening pressure in the radial direction applied to the inner wall of the processing part by the mechanical expander 10, Upper side of the pipe a to be processed (the side where tensile stress is generated due to bending moment)
Prior to this, the lower side in the figure (the side where compressive stress is generated due to bending moment) yields, the outer diameter increases, the tube contracts in the length direction, and the convex bend on the lower side is corrected. , the decrease in wall thickness is prevented and the wall thickness is appropriately adjusted.

Furthermore, since a radial straightening pressure is applied to the inner wall of the processing section of the pipe to be processed, and at the same time a bending moment for straightening the pipe bending is applied from the outside, the load of the bending moment can be much smaller than when it is applied alone. Furthermore, the straightness correction performance is significantly improved as well as the roundness correction performance.

(Effects of the Invention) As described above, in the present invention, an expander is placed inside the pipe to be processed to apply straightening pressure in the radial direction to the inner wall of the processed part, and a pipe straightening device is used to straighten the pipe from the outside of the pipe to be processed. At the same time, a bending moment for straightening the pipe can be applied, and the synergistic effect of the straightening pressure in the radial direction and the bending moment for bending the pipe significantly improves the straightness straightening performance as well as straightening the pipe to be processed. , the bending moment can be significantly reduced compared to a single action, and the straightening pressure in the radial direction can also be reduced. Furthermore, the wall thickness can be adjusted, and the straightening performance and reliability of the pipe are significantly improved. .

(Other Embodiments of the Invention) Another specific embodiment of the present invention is shown in FIG. The pipe bend straightening device of this embodiment, which is an expander, includes a support roll 21 disposed above the expander frame 20 and a gate-shaped frame 23 erected on the expander frame 20. A presser roll 22 is disposed inside, a position adjustment jack 24 is installed on the gate-shaped frame 23, and a pressure cylinder 25 is connected to the jack 24.
The structure is such that the position of the presser roll 22 is adjusted and a load W is applied, and the pipe to be processed a on the transport roller 26 is transported to the right side in the figure by a pipe transport device (not shown), and then transferred to the mechanical expander 1.
When the processing section of the pipe to be processed a is placed on
radial correction pressure can be applied to the inner wall of the machined part, and the position adjustment jack 24
And by applying a load W' downward in the figure to the presser roll 22 using the pressure cylinder 25,
The structure is such that a bending moment for straightening the tube bending is applied during processing of the tube to be processed a, and the roundness and bending of the tube to be processed can be simultaneously corrected, and the support roll and presser roll of this embodiment are each 1
Although the embodiment is individual, it is possible to obtain the same effects as the embodiment shown in FIG.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

FIG. 1A is a longitudinal sectional view showing an embodiment of the present invention, FIG. 1B is a cross-sectional view taken along the line I-I in FIG.
The figure is a partially sectional side view of another embodiment of the present invention, FIG. 3A is a vertical sectional view of the previously developed mechanical expander, and FIG. 3B is a cross-section of the minus part of FIG. 3A. Figures 4A and 4B are a side view and a sectional view of the - portion of the pipe to be processed, showing a bent state. 1: Pull rod, 2: Cone, 3: Segment, 4: Support tube, 10: Expander (mechanical expander), 11a, 11b, 21: Support roll, 12a, 12b, 22: Presser roll,
24: Position adjustment jack, 25: Pressure cylinder, a: Processed pipe.

Claims (1)

[Claims] 1. An expander that is disposed inside the pipe to be processed and applies straightening pressure in the radial direction to the inner wall of the processing section of the pipe to be processed, and simultaneously with the straightening pressure processing of the expander, bending for straightening the pipe bending from the outside of the pipe to be processed. A pipe straightening device comprising: a pipe bending straightening device that applies a moment.