JPS5973115A - Stepped and drawn steel pipe - Google Patents

Abstract

PURPOSE:To provide a wrinkle-free stepped and drawn steel pipe having exact plural diameters by fixing a die and a tap movably in a drawing direction, providing plural bearing parts thereto, combining suitably the bearing faces and drawing the steel pipe. CONSTITUTION:A die 2 having bearing parts of a large diameter d1 and a small diameter d2 is fixed to a support base and is made movable on a frame. A plug 4 having bearing parts of a small diameter d3 and a large diameter d4 is provided movably by means of a hydraulic cylinder. The d2 face of the die 2 and the d3 face of the plug 4 are positioned to face to each other and a steel pipe is drawn, whereby a pipe having the outside diameter d2 and the inside diameter d3 is formed. The d2 face of the die 2 and the d4 face of the plug 4 are then placed to face to each other and the steel pipe is drawn, whereby the pipe having the outside diameter d2 and the inside diameter d4 is formed. The d1 face of the die 2 and the d4 face of the plug 4 are further positioned to face to each other and the pipe is drawn, whereby the pipe having the outside diameter d1 and the inside diameter d4 is formed. A steel pipe 7b having the outside diameters d1, d2 and the inside diameters d3, d4 is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stepped drawn steel pipe having a plurality of inner diameters and outer diameters and used as a casing or the like.

Conventionally, for example, steel pipes with large diameters and thick walls, as shown in Figure 1,
That is, in order to manufacture the tube 7b which has thick walls at both ends and a thin wall at the middle, the forged steel tube at both ends and the middle steel tube having a uniform diameter are welded together.

Also, the diameter is approximately 23-3 mNs, and the wall thickness is a. l~3. In the case of small-diameter, thin-walled steel pipes used for materials such as bicycles, etc., they were manufactured using a steel pipe drawing device as shown in Figure 2.

FIG. 2(a) is a longitudinal cross-sectional view of section A in FIG. A die support stand 3 for fixing the dice is provided approximately at the center of a frame l fixed to the floor, and a plug support rod 3 is provided to support the plug support.On the left side of the plug support stand is a hydraulic cylinder (not shown). Fix it via etc. The water conservancy steel pipe 7 (obraguku) is inserted into the outside of the plug support rod j, and its tip a is held by scissors g provided on the extraction vehicle.The claw IO of the extraction vehicle is driven by a powerful driving source (not shown). The product steel pipe 7b is manufactured from the raw material steel pipe 7 by being strongly pulled by the chain // driven by the material steel pipe 7 while being clamped between the die and the plug.

When manufacturing pipes using the equipment shown in Figure 1, for steel pipes with one type of outer diameter and different inner diameters, place the plug in front of the die so that it does not interfere with the drawing in the steel pipe drawing direction e, as shown in Figure J fPL). A small inner diameter steel pipe section is created which is held with a gap between it and the pipe tip 7a and is pulled out by pushing the plug in the die a as shown in Fig. 3 (1)). The inner diameter steel pipe section is created. Next, for steel pipes with one type of inner diameter and different outer diameters, the flange is pushed into a die and pulled out as shown in Figure 9 (a), and a steel pipe with a smaller outer diameter is manufactured, as shown in Figure 7 (b). When the flange is pushed to the left of the die and the rolling steel pipe 7 is pulled out, the outer diameter is narrowed between the die and the small diameter bearing part of the flange, and as it moves further, the diameter of the raw steel pipe 7 is reduced by the large diameter bearing part of the flange. is enlarged, the inner diameter is the same diameter as the large diameter bearing part of the flange, and the outer diameter is as shown in Figure 7 (a).
) A steel pipe 7b having a diameter larger than that of the previous one is manufactured.

As mentioned above, according to the conventional device, (1) Fig. 3 (8)
Small inner diameter steel pipes that have been worked on in this way tend to wrinkle because there is no internal pressure from the plug and the outer diameter is tightened. (2) For steel pipes with one type of inner diameter and two types of outer diameter made by the work shown in Figure DA (b), first, the steel pipe made of the bearing surface of the die and the small diameter bearing surface of the plug. As a result of further expanding the large-diameter bearing surface of the plug, the external appearance will be as shown in Fig. 7 (f), so here is the shape shown in Fig. 7 (
Let us explain this case using f). Large bearing diameter of d-nib lug, d2 = bearing diameter of die, (1/:
Large outer diameter of steel pipe, cl,? Assuming the small bearing diameter of the nib lug, dll is the inner diameter of the steel pipe and dco is the small outer diameter of the steel pipe, but the large outer diameter of the steel pipe (1/ is not directly connected to the bearing diameter of the die and plug, but d/ =f(dco, cl3
．． +i g) is established, and (17, +12.
d cannot be determined independently. In other words, the most desired cl/
, dco, d4/ is determined by d/=f(clco, d,
7. The method is to select the one closest to the desired value among the various solutions for dll), and it is not possible to obtain the exact desired diameter d/, (i, ap). Limited to two types of steel pipe: inner diameter type 1, outer diameter type 1, or inner diameter type 1, outer diameter type 1. (4) A stopper etc. built into the hydraulic cylinder is used to make the plug take the two fixed positions. However, when a large pulling force is required, a large number of cylinders are used, and a balancing device or the like is required between them, resulting in a complicated structure.

The present invention improves these problems in a device that uses steel pipes with multiple diameters for manufacturing, by (1) movably fixing the die support to the frame, and (2) fixing each of the die and plug to the frame. The objective is to provide a stepped drawn steel pipe with multiple diameters that are wrinkle-free, accurate, and have the required diameters by constantly pinching and pressing the raw steel pipe between the bearing surfaces of a die and a plug with multiple bearing surfaces and then pulling it out. shall be.

Embodiments of the present invention will be described below with reference to the drawings.

Regarding the apparatus to be used first, FIG. 5 is a side view of a die support stand, in which a stopper 16 is strongly fixed to a frame l and reinforced with a reinforcing member 17. A die support stand 30 equipped with a large number of hydraulic cylinders O is movably mounted on a truck /J, and the truck moves on a rail /Ja. /
or is a die support fixing ram, for example, as shown in FIG. The / and ta surfaces of lb are pressed by pressure generated from a hydraulic cylinder O through a lug 2y that is fixed to a stopper L connected to a piston rod 3 and a bino S and protrudes from a die support fixing ram 13. Hydraulic cylinder cylinder O
The pressing force generated by the steel pipe is a force that opposes the steel pipe pulling force, and must have sufficient margin compared to the pulling force (for example, l left θ to co 00t). In order to fix it at a specific point with such strong force, we used the method of pressing it against a stopper and fixing it because it is the simplest and most reliable method. Therefore, the die-〇 fixing position is the position explained above is the right fixing position (Fig. 5 (a)), and the stopper
The position where the 30kJ surface of the die support stand 30 is still in contact with the 166th surface of '16 is the left fixed position.

FIG. 6 is a cross-sectional view of the plug support stand, where l is a frame, stoppers /I, a are firmly fixed to the frame /, and are further reinforced with reinforcing parts /7a. The main shaft /g into which the plug support rod 5 is inserted and which locks and supports the large end of the support rod S, ta, has a thread cut on its outer periphery and a nut type stopper /9.
is screwed in. Nut type stopper/q is product steel pipe 7
The screws can be adjusted to meet the required dimensions of b. The nut type stopper 19 on the left side is the stopper/Aa/
The position where it contacts the /ib surface is the right side fixed position of the bragg, and the right nut type stopper /? is attached to the 760 side of the stopper 16. The position where the two abuts is the left-side fixed position. flame/
The pushing or pulling pressure of the hydraulic cylinder Oa fixed to the cylinder generates a pressure that is sufficiently larger than the roaring pulling pressure. The ram λl is fitted into the end of the main shaft 7g, and the ram fixing nut (2.2) is screwed into the male thread at the tip of the ram holder l to fix it to the main shaft l.

Similarly, in FIGS. 3 and 6, regarding the movement of the dice or plug during fixation or steel pipe drawing, the dice is connected to the hydraulic unit 13, the plug is connected to the hydraulic unit/3FLj, and the resulting hydraulic pressure is connected to the piping/4', piping/ It is supplied to hydraulic cylinder 〇 or J (7a) through Fa.

Next, the operation for obtaining stepped drawn steel pipes having multiple diameters will be explained with reference to FIG. FIG. 7(a) shows the die support stand 3.
The state in which θ is fixed at the left fixed position explained in FIG. 5 and the right fixed position explained in FIG. In the figure, d is the small bearing diameter of the dice, and d3 is the small bearing diameter of the plug. Figure 7(b)
1 shows a state in which the die support stand 30 is fixed at the left fixed position, and the plug support is fixed at the left fixed position and pulled out.

In the figure, d is the small bearing diameter of the dice, and d (7 is the large bearing diameter of the plug).

FIG. 7(C) shows a state in which the die support 30 is fixed at the right fixed position, and the plug support is fixed at the left fixed position and pulled out. In the figure, d/ is the large bearing diameter of the dice, d
F is the large bearing diameter of the plug. In other words, (
If the operations a), (b), and (C) are continued in this order, the manufactured steel pipe 7b shown in FIG. 7(e) is manufactured, and the operations are continued in the order of (a), (b), and (a) in FIG. Then, the manufacturing steel 7b shown in FIG. 7(d) is manufactured, and the manufacturing steel 7b shown in FIG.
(If you work in the order of (1), (b), and (0), the 7th
A manufactured steel pipe 7b shown in FIG. 7(f) is manufactured.

During the drawing operation, the movement of the dice and the bragg is carried out by the hydraulic unit 13 and i and th according to a pre-installed automatic control schedule, taking into account the relationship with the steel pipe drawing speed.

As mentioned in the explanation of Figure 7 (1)) with reference to Figure 7 (f), with the conventional ' method, it was not possible to manufacture product steel pipes with the required inner and outer diameters. In an embodiment of the invention, by setting the required outer diameter of the manufactured steel pipe to the bearing diameter of the die and the required inner diameter to the bearing diameter of the tap, it is possible to provide a steel pipe having a plurality of required inner and outer diameters. done. Since the inner and outer diameters are drawn under pressure between the bearing surfaces of the die and tap, a steel pipe with good surface accuracy can be produced.

In addition, as shown in Figure 1, welded, cast, or turned steel pipes have fibers in the metallographic structure that are cut in the axial direction of the pipe at welds, blowholes, and turned steps, so severe heat treatment can cause cracks. However, in the stepped drawn steel pipe according to the present invention, since the fibers of the metal structure are continuous in the axial direction of the steel pipe, it is strong and has an optimal metal structure when subsequent heat treatment is required. .

An example of the product will be described next. Figure 1 shows the final shape.

T is the joint between manufactured steels. Outer diameter: ff, 9, thick part =
6.5, Thin part: Ar, Length: 2~Am, Material;
Mn-Or-MO steel, heat treatment: quenched and tempered to final structure martensite, hardness: Shore I13, strength: 90Kg
/llI2, Recessive joint T: Thick white part Acme taper screw, Applications: Exploration of underground resources such as uranium, metals, geological surveys, etc. With rotation of gOθ ~ /θOθR, P, M, underground 1
Used for polling to a depth of 000 to 00m.

As described above, the present invention has a die support stand and a plug support stand that are capable of moving the die and the plug in the forward and reverse directions of the drawing direction and firmly fixing the die and the plug in the set position. A stepped steel pipe with a plurality of inner and outer diameters produced by being pulled out while being squeezed by bearing surfaces facing each other, and having inner and outer diameter surfaces with good accuracy of the required diameter. In addition, it has become possible to provide a stepped drawn steel pipe that is strong and has characteristics suitable for subsequent heat treatment.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing an example of manufactured steel pipe, No. 0, 1 (
b) No. 4/) A vertical cross-sectional view showing the conventional method of manufacturing steel pipes by drawing, FIG. 5 is a side view of the die support used in the present invention, and FIG. S (8) is B of FIG. FIG. 4 is a longitudinal sectional view showing details of the plug support used in the present invention, FIG. 7(a), M-cut diagram (b), and FIG. Vertical sectional view showing the pulled out state, FIG. 7(d), FIG. 7(
e) and FIG. 7(f) are longitudinal cross-sectional views showing the manufactured steel pipe of the present invention, and FIG. 3 is a vertical cross-sectional view showing an example of the final product. Co-dice Gu... Plug 16... Stotsuno<
/ 4 Q, @ @Stotsunomae ig@ -Main shirt) 30- Dice support d/, dj... Dice bearing diameter dj, dl... Plug bearing diameter. Figure 1 Figure 2 and Figure 2 (S$ 3 m (a) 3rd (b) Figure 4 (0)
End 4 diagram (b) 13α no 9 is 7 Y go (+) 79-

Claims (1)

[Claims] l The die and tap are fixed so that they can be moved one angle in the drawing direction,
A stepped drawn steel pipe with multiple required inner and outer diameters that is pulled out while being squeezed by bearing surfaces that face each other.