US3808862A

US3808862A - Apparatus for forming spiral steel pipe

Info

Publication number: US3808862A
Application number: US00267459A
Authority: US
Inventors: Y Tanaka; Y Shimazaki; K Hagiwara
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 1971-06-30
Filing date: 1972-06-29
Publication date: 1974-05-07
Anticipated expiration: 1991-05-07
Also published as: JPS5042135Y2; JPS4813534U; DE2232158B2; CA975223A; DE2232158C3; DE2232158A1

Abstract

An apparatus for forming spiral steel pipe by separate type forming rolls which is characterized by stands carrying rolls for forming the inner and outer surfaces of the steel pipe, the stands being each split into two portions in a direction perpendicular to the axis of the steel pipe to be formed, one of the two portions being a fixed stand formed with a smaller length than the width of material plate for the intended steel pipe and the other portion being a stand movable in the axial direction of the steel pipe to be formed.

Description

United States Patent [191 Tanaka et al.

[ APPARATUS FOR FORMING SPIRAL STEEL PIPE [75] Inventors: Yasuhiko Tanaka; Yasumi Shimazaki; Kenii Hagiwara, all of Kitakyushu, Japan [73] Assignee: Nippon Steel Corporation, Tokyo,

Japan [22] Filed: June 29, 1972 [21] Appl. No.: 267,459

['30] Foreign Application Priority Data June 30, 1971 Japan 46-56783 [52] US. Cl. 72/135, 29/477.3 [51] Int. Cl B2lf 3/02 [58] Field of Search 72/49, 50, 135, 368, 371;

[56] References Cited UNITED STATES PATENTS 3,407,639 l0/l968 Kehne 72/135 [451 May 7,1974

3,606,783 9/1971 Lewis 29/477.3

Primary Examiner-Charles W. Lanham Assistant Examiner-Robert M Rogers Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [5 7] ABSTRACT An apparatus for forming spiral steel pipe by separate type forming rolls which is characterized by stands carrying rolls for forming the inner and outer surfaces of the steel pipe, the stands being each split into two portionsin a direction perpendicular to the axis of the steel pipe to be formed, one of the two portions being a fixed stand formed with a smaller length thaii th e width of material plate for the intended steel pipe and the other portion being a stand movable in the axial direction of the steel pipe to be formed.

4 Claims, 5 Drawing Figures msmanm 1 m4 3308.862

, FLUID PRESSU CYLINDER sYs APPARATUS FOR FORMING SPIRAL STEEL PIPE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming spiral steel pipe and more particularly to an apparatus for forming spiral steel pipe which comprises separate rolls for forming the inner and outer surfaces of the spiral pipe.

2. Description of the Prior Art In an apparatus for forming spiral steel pipe by spirally bending steel plate, insufficient bending of a steel plate end usually gives rise, as shown in FIG. 1, to an abnormal bulging, or peaking 4 in the vicinity of the weld in the plate 2 of the formed steel pipe 1. This abnormal deformation 4 lowers the strength of the welded joint and spoils the beauty of the appearance, thus being very undesirable in respect of the product value.

It is said however that a relatively small amount of peaking takes place in forming steel pipe by means of so-called separate type forming rolls which comprise a multiplicity of separate rolls for forming the inner and outer surfaces of the steel pipe. Nevertheless, on occasion the peaking exceeds two millimeters. A typical apparatus for forming spiral steel pipe by separate forming rolls comprises, as shown in FIG. 2, a set of innersurface forming rolls l2 fitted to a stand 11 and two sets of outer-

surface forming rolls

15 and 16 installed on

stands

13 and 14 respectively, the three sets of rolls being in triangular arrangement, with the firstmentioned set of rolls 12 at the vertex of the triangle and the two other sets of

rolls

15 and 16 at the opposed ends of the base thereof. The three sets of forming'rolls 12, 15 and 16 act on the material plate 2 so as to bend it spirally. As shown in FIG. 4, however, the steel plate SUMMARY OF THE INVENTION The present invention obviates these problems by providing a forming apparatus which always enables a side end of a steel plate of any width to engageflwith rolls for forming the inner and outer surfaces. The invention contemplates an apparatus for forming spiral steel plate by separate type forming rolls which is characterized by having stands carrying rolls for forming the inner and outer surfaces of the steel pipe, the stands being each split into two portions in a direction perpendicular to the axis of the steel pipe to be formed, one

.of the two portions being a fixed stand formed with a smaller lengththan the width of the material plate for the intended steel pipe and the other portion being a stand which is movable in the axial direction of the steel pipe to be formed.

An object of the present invention is to provide an apparatus for forming spiral steel pipe by bending plate material in a manner so as to inhibit abnormal deforma- 2 tion such as peaking from taking place at the welded joint. p Another object of the invention is to provide an apparatus for forming spiral steel pipe which is effective to prevent the abnormal deformation from ocurring at the welded joint and also simple in construction and easy to operate.

These and other objects of the present invention will be more clearly understood when the following description of a preferred embodiment is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an abnormal deformation caused by a conventional apparatus.

FIG. 2 is a side view of an apparatus for forming spiv thereof, the stands being disposed in two rows A and B extending in parallel in the axial direction of the pipe 1 to be formed, as a matter of functional necessity. The

and 20 are in alignment with the fixed stands 17 and 18- respectively' and located on the rear side of the fixed stands 1.7 and 18, that is, on the leading side thereof with respect to the direction in which the pipe 1 being formed advances. The

stands

19 and 20 are 'movable up to one pitch of the outer-

surface forming rolls

15 and 16 in the axial direction of the pipe 1 to beformed. Any

stand movement exceeding one pitch of the rolls is not necessary at all in view of the fact that the major object of the apparatus of the present invention is to prevent abnormal defonnation at the joint by placing an entire steel plate end on rolls without fail. The shift of the

movable stands

19 and 20 can be effected by a relative slide between surfaces or by means of rollers, which should be construed as non-limitative and any other desired means may be employed for the purpose.

Devices

21 and 22 which may be used for shifting the

movable stands

19 and 20 employ a screw mechanism in this embodiment-That is, threaded drive shafts 23 and 24 extending in the longitudinal direction of the movable stands'l9 and 20 are secured to .the rear ends of the

movable stands

19 and 20 respectively. The drive shafts 23 and 24 are fitted with threaded

sleeves

25 and 26 respectively and rotation of the sleeves will advance the

movable stands

19 and 20 through the drive shafts 23 and 24. Also it is possible as a matter of course to apply a fluid pressure cylinder system to the shift adjusting

devices

21 and 22. Furthermore, the lengths of the fixed

stands

17 and 18 are not particularly limited so long as the said lengths are smaller than the width of the plate material for the steel pipeto be formed. If the fixed stands should be wider than the plate material,

the function and effect of the movable stands in the apwould be lost.

The stand which carries the inner-surface forming rolls is also composed of a fixed stand and a movable stand in entirely the same manner as the stands for the outer-surface forming rolls.

Operation of the heretofore described apparatus of the present invention when the steel plate material for the steel pipe to be formed is supplied to the apparatus will now be described by reference to FIG. 4. (For conveneince of illustration, only the operation of the outersurface forming rolls and their stands will be described. However, the operation is entirely the same as the operation of the inner-surface forming rolls and the stand therefor.) When a side end 3 of the steel plate 2 is not mounted on the forming rolls l5 and 16 but positioned in the inter-roll space, the screw mechanism of the

devices

21 and 22 for adjusting the shift of the movable stands 19 and is operated to shift the movable stands l9 and 20 to an adequate position (indicated by dashed line in the illustrated embodiment) within the pitch of the outer-surface forming rolls in the axial direction of the steel pipe 1 to be formed, thereby placing the side end} of the material steel plate 2 on the outersurface forming rolls l5 and 16. The direction of advance of the steel pipe being formed is denoted by a, the direction of feeding the steel plate 2, by b, and the direction of shifting the

movable stands

19 and 20, by

It will be apparent from the foregoing description that, according to the apparatus of the present invention, the material plate for the steel pipe to be formed can be subjected to formation with a side end thereof always placed on the outer-surface forming rolls so that the abnormal deformation which is called peaking can be prevented from taking place at the pipe joint. Thus, the present apparatus displays an exceedingly desirable effect in enabling the produced steel pipe to have a high quality.

What is claimed is:

1. An apparatus for forming spiral steel pipe by separate type forming rolls which is characterized by stands carrying rolls for forming the inner and outer surfaces of the steel pipe, the stands being each split into two portions in a direction perpendicular to the axis of the steel pipe to be formed, one of the two portions as a fixed stand formed with a smaller length than the width of the material plate for the intended steel pipe and the other portion as a stand movable in the axial direction of the steel pipe to be formed.

2. An apparatus as defined in claim 1, characterized in that the shift of the movable stands in the axial direction of the steel pipe to be formed is within one pitch of the forming rolls.

3. An apparatus as defined in claim 1, characterized in that the movable stands are shifted in the axial direction of the intended steel pipe by means of a screw mechanism.

4. An apparatus as defined in claim 1, characterized in that the movable stands are moved axially of the intended steel pipe by means of a fluid pressure cylinder system.