JPH035006A - Reducing device of pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tube insertion/extraction processing device used for manufacturing forged tubes.

[Conventional technology]

As a manufacturing technology for forged tubes, a punching technique in which a mandrel is inserted into a bottomed tube, a thrust is applied to the mandrel in the axial direction, and the bottomed tube is inserted into a roll stand is disclosed in JP-A-64-71507. It is disclosed in the publication No. The roll stand includes a pair of cylindrical rolls for rolling, which are supported and opposed to each other with a rotation axis extending in a direction perpendicular to the pass line so that the rolling position can be adjusted, and a pair of the cylindrical rolls. A pair of guide locks are provided in the gap, with a pass line in between and supported in a manner that allows the interval to be adjusted. Examples of pass schedules for manufacturing forged pipes using the roll stand are shown in FIGS. 5(a) to 5(c).

First, as shown in FIG. 5(a), a mandrel 30 is attached to a bottomed tubular material 40 heated to a predetermined temperature before processing starts.
is inserted. Next, as shown in FIG. 5(b), an axial thrust is applied to the mandrel 30, and the material 40 is pushed between the cylindrical rolls lla and llb that have been adjusted to a predetermined rolling position. Thickness reduction processing is added to 40. At this time, in order to prevent the material 40 from widening, the material 40 is restrained from both sides by a pair of guide blocks 12a, 12b between the cylindrical rolls 11a, flb.

When the first punching process is completed in this way, the material 40 is transferred to the mandrel 3 as shown in FIG.
0 and rotate 90 degrees in the circumferential direction. Then, the material 40 is pushed between the cylindrical rolls lla and 11b whose rolling position has been readjusted. After the second punching process, Figure 5(e)
As shown in (g), the material 40 is rotated by 45 degrees together with the mandrel 30 and pushed between the cylindrical rolls lla and llb whose rolling position has been readjusted. When the third punching process is completed, as shown in FIGS. 5(g) and 5(h), the material 40 is rotated 90 degrees together with the mandrel 30, and the cylindrical rolls lla and llb whose rolling positions have been readjusted are placed. Push it in between.

Even in the second to fourth punching operations, the pair of guide blocks 12a and 12b prevent the material 40 from widening. The guide blocks 12a, 12b have a spacing set equal to or slightly larger than the width of the material 40 before processing, and do not have a function of rolling down the material 40.

After the fourth punching process, the steps shown in Fig. 5(e) to
Step (h) is repeated.

[Problem to be solved by the invention]

In the manufacturing technology of forged pipes using such punching, the fifth
The inventors' investigation revealed that the following problem occurs during the third punching process shown in FIGS. (e) and (f).

The portion processed by the cylindrical roll in the third punching process is an outwardly convex portion of the material. Therefore, the material tends to become unstable in the circumferential direction during punching, and as a result, rotation in the circumferential direction called folding occurs in the material, and the convex portion to be processed may not be able to be processed. This phenomenon occurs when there is no room for the material to rotate, as in the first machining shown in Figures 5(a) and (b), or when there is no room for the material to rotate, as shown in Figure 5(C).
This does not occur when the flat surface of the material is restrained by the guide block, as in the 2.4th machining shown in (d) and (g) (5). The reason why this phenomenon is likely to occur in the third machining shown in Fig. 5(e) and (f) is that the material restraint by the guide block is essentially a point restraint, and the convex part is This is because the material becomes easier to rotate due to the processing applied to it.

This phenomenon, called sagging, cannot be prevented even if the mandrel is restrained in the circumferential direction if the machining process generates a rotational force that exceeds the circumferential frictional force between the inner surface of the material and the outer surface of the mandrel. do not have. - Once this collapse occurs, the machining of the material becomes uneven in the axial direction, and it is difficult to correct it during machining. This brings about the above problem.

An object of the present invention is to provide a tube insertion/extraction processing device that can prevent the above-mentioned sag and ensure sound processing in all punching operations.

[Means to solve the problem]

The tube insertion/extraction processing device of the present invention is a tube insertion/extraction processing device for thinning a bottomed tube by inserting it into a stand using a mandrel, and has a rotating shaft extending in a direction orthogonal to the pass line across the pass line. A pair of cylindrical rolls for rolling down which are supported and opposed to each other so that the rolling position can be adjusted; and a pair of guide blocks which are supported and opposed to each other with a pass line between them so that the distance between them can be adjusted. and a pair of guides for preventing material rotation, the distance of which can be adjusted, and which are disposed on the entry side of the roll stand and offset in the circumferential direction with respect to the pair of guide blocks.

[For production]

In the tube insertion/extraction processing apparatus of the present invention, the guide pair for preventing material rotation is provided on the entry side of the roll stand and is offset in the circumferential direction with respect to the guide block of the roll stand. Even if it is not possible to restrain
The material can be restrained by the pair of guides and its rotation can be prevented. If the material can be restrained by the guide blocks, material passage between the guide pairs is ensured by opening the guide pairs.

〔Example〕

The present invention will be described below with reference to Examples.

As shown in FIGS. 1 to 3, the front pressing device of this embodiment includes a roll stand IO, a guide pair 20 provided on the entrance side thereof, and a mandrel 30.

The roll stand 10 has a pair of cylindrical rolls 11 a
, l l b, and a pair of guide blocks 12a, 1
2b is incorporated. a pair of cylindrical rolls lla;
llb is separated by the pass line L, its rotating shaft extends in a direction perpendicular to the pass line L, and is arranged parallel to the pass line L, and both shaft ends are idle supported by bearings (not shown) so as to be able to freely rotate in the forward and reverse directions. has been done. The bearings are attached to the roll stand housing (not shown) via a screw jack and/or a hydraulic pressure reduction device (also not shown), and thereby the cylindrical rolls lla, l
The lb rolling position, in other words, the roll gap can be adjusted.

The pair of guide blocks 12a and 12b are prismatic bodies with a rectangular cross section that are long in the direction of the pass line L, and are arranged in a direction perpendicular to the direction in which the pair of cylindrical rolls lla and llb are disposed, in other words, they are circular. Between the columnar rolls 11a and flb, opposite surfaces 13a and 13 are formed across the pass line L.
b are arranged opposite to each other so as to be parallel to the pass line L.

The back surfaces 14a and 14b are attached to a roll stand housing (not shown) via appropriate position adjustment means such as a screw jack mechanism or a tapered mechanism (not shown), and thereby the guide block Opposing surfaces 13a, 13 of 12a, 12b
The interval b can be adjusted.

The guide pair 20 provided on the entry side of the roll stand 10 consists of two block pairs. One pair of blocks is the pair of guide blocks 12a.

A pair of prismatic blocks 21a similar to 12b.

21b. The pair of blocks 21a and 21b are the same as 1 above.
A pair of guide blocks 12a and 12b are arranged at a position offset by 45 degrees in the circumferential direction with respect to the direction in which they are opposed, with the pass line L being interposed between them so that their opposing surfaces 22a and 22b are parallel to the pass line L. It is set up. a pair of blocks 21a,
The back surfaces 23a and 23b of 21b are opposite surfaces 22a,
22b is attached to a housing (not shown) via an appropriate position adjusting means such as a screw mechanism or a tapered mechanism (not shown) so that the interval between the two parts 22b can be adjusted.

The other block pair is a pair of prismatic blocks 2 that are offset by 90 degrees in the circumferential direction with respect to the opposing direction of the one block pair.
4a and 24b, and have the same configuration as the one pair of blocks described above, except that they are arranged in different directions.

The distance from the roll stand 10 to the guide pair 20 is desirably shortened as much as possible within a range that does not interfere with equipment in order to enhance the material holding effect.

The mandrel 30 has a circular cross section, and its outer diameter is the same as or slightly smaller than the inner diameter of the circular cross-sectional product tube to be obtained, and its length is longer than the length of the product tube,
Its base end (left side in Figure 1) is connected to the ram head of a hydraulic press via a universal joint or the like, similar to a so-called bush bench pipe making device.

The forged tube manufacturing process using the tube insertion/extraction processing apparatus having such a configuration is as follows.

With the mandrel 30 retracted, a bottomed tubular material 40 heated to a predetermined temperature is fitted and held at the tip of the mandrel 30. Next, the mandrel 30 is advanced to insert the material 40 into the roll stand 10 (see FIG.
a) (see b)). The interval between the cylindrical rolls lla and jlb in the roll stand IO is set so as to give a predetermined rolling edge to the material 40, and the guide block 1
The distance between 2a and 12b is set to be the same as or slightly larger than the outer diameter of the material 40 before processing. Also,
The block pair gap in the guide pair 20 is set to be sufficiently wide so as not to hinder the passage of the material 40.

With such a gap setting, the material 40 is subjected to a thinning process between the cylindrical rolls lla and 11b during the first punching process, and the width of the material 40 due to the thinning process is expanded at the guide blocks 12a and 12b. Prevented. Since there is no room for the material 40 being processed to rotate, even if the guide pair 20 is open, a material rotation phenomenon called sagging does not occur.

When the first punching process is completed, the material reduction roll lla
, llb and guide block 12a.

12b is once opened, the mandrel 30 is retreated to pull the material 40 back to the entrance side of the roll stand 10, and then the mandrel 30 is rotated 90 degrees in the circumferential direction. During the rotation operation of the material 40, the spacing between the cylindrical rolls 11a, llb is
It is reset so that a predetermined reduction edge can be applied to the material 40, and the interval between the guide blocks 12a, 12b is set to be equal to or slightly larger than the horizontal width dimension of the material 40 after rotation. The guide pair 20 remains fully open. In this state, the material 40 is inserted into the roll stand IO and the second punching process is performed (Fig. 5(C)
) (see (d)). After that, the material 40 is prepared in the same manner as above.
Pull it back to the entrance side of the roll stand IO.

In the second punching process, the smooth surface of the material 40 is restrained by the guide blocks 12a, 12b, so that the material 40 does not sag even if the guide pair 20 is open. By the second punching process, the material 40 is formed into a tube with a substantially circular inner surface and a deformed outer surface, with smooth surfaces on all four sides of the outer surface in a direction perpendicular to the rolling direction. During the third punching process, the mandrel 30 is rotated 45 degrees in the circumferential direction.

Blocks 21a, 21b and 2 in guide pair 20
The interval between 4a and 24b is set to be equal to or slightly larger than the width dimension of the material 40 after rotation in the opposing direction, that is, the distance between the surfaces. The distance between the material reduction rolls lla and 11b in the roll stand 10 is set so as to provide a necessary reduction edge between the diagonal convex portions of the material 40,
The distance between the guide blocks 12a and 12b is set to be the same as or slightly larger than the distance between the convex portions, or is completely opened. In this state, the material 40 is inserted into the roll stand 10 and punched out for the third time (see FIGS. 5(e) and 5(f)).

During the third punching process, the material 40 is transferred to the roll stand 1
At 0, the material is rolled down between the convex portions in an unstable state by the material rolling down rolls lla and 11b.

Further, the guide blocks 12a, 12b also do not contribute to holding the material 40 regardless of their spacing. However, since the material 40 is supported between smooth surfaces by the guide pair 20 on the entry side of the roll stand IO, no sagging occurs in the material 40.

When the third punching process is completed, the material 40 is pulled back to the entry side of the roll stand lO in the same manner as the first and second punching processes, and the mandrel 30 is rotated 90 degrees in the circumferential direction to
The punching process is performed for the second time (see FIGS. 5(g) and (h)).

In the fourth punching process, the material reduction roll lla,
The distance between the guide blocks 12a and 12b is set to be equal to or slightly larger than the width of the material in the opposing direction. Further, the guide pair 20 is sufficiently opened so as not to impede the insertion of the material 40. The material 40 is inserted between the smooth surfaces of the guide blocks 12a, 12.
Since it is restrained by the guide pair 20, sagging will not occur even if it is not restrained by the guide pair 20.

After the above processing, processing similar to the third to fourth processing is repeated as necessary.

After processing, the material is punched through a die having a perfect circular inner diameter that is the same as or slightly larger than the outer diameter of the product pipe with a circular cross section to be obtained with the mandrel 30 inserted, to produce a product with a circular cross section on both the inner and outer surfaces. It is formed into a tube with light workability. This final forming process can be carried out in succession to the above-mentioned process by arranging a stand having a die or the like at a subsequent stage of the roll stand 10.

In the above embodiment, two sets of opposing blocks are provided as the guide pair 20, but as shown in FIG. 4, one set of opposing blocks 21a and 21b may be provided, or three May be used as a block.

However, the effect of restraining the material 40 is the highest in the four-sided block adopted in the above embodiment. Note that whichever block is adopted, it is necessary to include a pair of opposing blocks, and that pair of blocks is the guide block 12a.

In order to restrain the smooth surfaces of the material 40 when the material 40 cannot be restrained by the guide blocks 12b, the facing direction thereof is offset in the circumferential direction with respect to the facing direction of the guide blocks 12a and 12b according to the shape of the material. It is necessary to do so.

Further, the guide pair 20 may be a roller guide.

Regarding the roll stand IO, it is possible to arrange multiple stands in tandem depending on the number of processes, and in that case, instead of giving rotation to the material, it is necessary to give a corresponding phase difference between the stands. There is. Further, the guide pair 20 need only be attached to the roll stand IO where there is a risk that the material 40 may sag.

Next, the results of implementing the present invention will be explained.

As the first stand, a roll stand with the roll configuration and gap settings shown in FIG. 5(b) is installed, and as the second stand, the roll stand with the roll configuration and gap settings shown in FIG. 5(d) is installed. A roll stand was provided with a phase difference of 90 degrees.

The third stand has the roll configuration shown in Figures 1 to 3 (however, the guide pair is 40-L), with a phase difference of 45 degrees with respect to the second stand, and according to the third punching schedule. A stand with a pair of guides with gap settings was installed. In addition, the fourth stand is shown in Figure 5 (
With the roll configuration and gap setting shown in b), a roll stand with a phase difference of 90 degrees with respect to the third stand was arranged. Then, punching was performed on this stand row.

The material before processing was a bottomed tube made of 320C with an outer diameter of 125 mm, a wall thickness of 20III11, a length of 500 mm, and a bottom thickness of 30 mm, and the heating temperature was 1200°C. Further, the outer diameter of the mandrel was 83 mm. Table 1 shows the gap amount at each stand.

The pair of guides in the third stand was provided at a center-to-center distance of 400 mm on the entry side of the roll stand, and the guide block in the roll stand was completely open to the material.

Table 1 (Sono) 6 As a result of punching 10 materials, no sagging occurred in any of the materials. However, when the guide pair was completely opened to the material in the third stand, sagging occurred in 6 of the 10 materials. This sagging occurred when a portion of 600 to 700 mm from the rear end of the material passed through the third stand, and the sagging of the rear portion caused processing defects.

〔Effect of the invention〕

The tube insertion/extraction processing device of the present invention prevents the material from sagging during processing by attaching a guide pair to the roll stand that is offset in the circumferential direction with respect to the guide block, and processes the material soundly in all passes. By doing so, it has a great effect on improving the yield and quality of forged pipes.

[Brief explanation of drawings]

Fig. 1 is a side view of a tube insertion/extraction processing device without showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line A-A in Fig. 1, and Fig.
4 is a drawing corresponding to FIG. 2 showing another embodiment of the present invention, and FIGS. 5(a) to (b) are explanatory diagrams of the pass schedule of punching be. In the figure, 10: roll stand, lla, 11b: material pressure roll, 12a, 12b guide block, 20 guide pairs, 30: mandrel, 40: material. 9 JP-A-3 5006 (7)

Claims (1)

[Claims] 1. A tube insertion/extraction processing device that reduces the thickness of a bottomed tube by inserting it into a stand using a mandrel, and allows the rolling position to be adjusted by extending a rotating shaft in a direction perpendicular to the pass line across the pass line. A roll stand having a pair of cylindrical rolls for rolling down that are supported and opposed to each other, and a pair of guide blocks that are supported and opposed to each other with a pass line between the opposing cylindrical rolls so that the interval can be adjusted; A tube insertion/extraction processing device comprising a pair of guides for preventing material rotation, the interval of which can be adjusted, and which are arranged circumferentially offset from the pair of guide blocks on the entry side of the roll stand. .