JPH04319007A - Method for manufacturing tubular product - Google Patents

Abstract

PURPOSE: To roll a shape of a metal bat for baseball with a cold Pilger mill by rolling it with one side of it chucked. CONSTITUTION: A roll stand 7, which is driven with two planetary crank driving devices 6 which are mutually arranged in mirror-symmetry and provided with a horizontal shaft via a connecting rod which is horizontally reciprocated, and which compensates a force and torque, is provided. A rotating and fowarding device 13 which holds a workpiece over the whole rolling processes is prefixed to the roll stand 7 and arranged on a carriage 11 which is able to travel to a working position, loading position and unloading position together with a rolling mandrel 2.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The invention relates to the cold rolling of tubes by force-driven ring-shaped rolls having a working profile of varying circumference and being rotatably supported in reciprocating roll stands. A method for producing a tubular workpiece having an outer diameter and, where appropriate, an inner diameter that varies over its length, in which the tube is advanced and rotated about a longitudinal axis, and for carrying out this method. Regarding the Cold Pilger Mill.

0002

BACKGROUND OF THE INVENTION The method and device mentioned at the outset are known, for example, from DE 31 29 103 A1. The goal of this known method is to produce a tube with an end that is thickened on the inside and/or outside for later provision of a threaded connection. This known method consists in providing different grooves (each groove being defined as a closed forming zone) on the work roll in order to produce tubes with different outer diameters at the tube ends. is proposed. For example, if two grooves are provided, one groove can pilger-roll a thin-walled tube section, and the other groove can pilger-roll a thick-walled tube section. There are applications for producing not only the ends of long tubes, but also entire tubular workpieces of short length and different cross-sections. Examples of such artifacts include baseball bats. Typically, a baseball bat consists of three zones. A cylindrical zone with a large diameter and short length, a zone with a larger length and a tapered diameter and wall thickness, and a cylindrical zone with a small diameter and, in the majority of cases, a short length. The production of such short tubular parts is not possible, or at least not economical, with conventional cold pilger rolling methods.

0003

OBJECT OF THE INVENTION It is possible to economically and in good quality produce tubular workpieces of short length and tapering cross-section over at least part of their length, advantageously baseball bats. The object of the present invention is to provide a method and an apparatus for carrying out the method.

0004

SUMMARY OF THE INVENTION The present invention provides a baseball bat with a tapered zone whose inner and outer geometry corresponds to the rolling mandrel and the development plane of the roll base curve. We start from the recognition that it is possible. From this recognition, the production of baseball bats or similar workpieces of such geometry can be achieved by cold pilger rolling with a correspondingly modified cold pilger mill if the ring-shaped roll is designed with a corresponding groove. This leads to the recognition that it is possible.

[0005] According to the invention, a tube for rolling short lengths of workpieces is fed into a rolling mill clamped at its non-rolling rear end, during the entire rolling process until the finished workpiece is discharged. It remains clamped on the same side of the roll stand and the geometry of the roll hole development surface corresponds to the outer contour of the finished workpiece and the geometry of the mandrel corresponds to the inner contour of the finished workpiece. It is suggested that you take action. It has been found that very high quality aluminum or aluminum alloy baseball bats can be produced by such a method. In this case, it has been found to be very advantageous for the economy of the process if the tube or finished workpiece remains clamped at all times, since this allows the feed of the workpiece in the conventional cold pilger rolling process. This is because additional time for derivation can be saved. If the invention allows the finished workpiece to be removed on the entry side of the roll stand, this represents a significant time saving.

[0006] In another feature of the invention, if it is desired to simultaneously increase the wall thickness in at least partial areas during the reduction rolling of the workpiece, it is provided that the mandrel is temporarily moved relative to the roll stand. axially moved. A different diameter can be used by returning the mandrel, or the mandrel can be removed from the nip completely.

Another feature of the invention increases the economy of the roll stand by allowing the roll stand drive to operate during the tube and workpiece loading and unloading steps. The method of loading and unloading on one side of the roll stand, which eliminates the need for complex and time-consuming unloading of finished workpieces on the entry side of the roll stand, increases the availability of the roll stand drive and thus the method. Efficiency is increased and setup time is minimized. Originally, in short tube parts, unloading on the exit side of the roll stand was problematic, since on this side the crank drive for the roll stand is usually provided. The invention allows the use of a common manipulator for feeding and removing workpieces and thus a simple and compact rolling mill for that purpose.

For example, in the case of a workpiece having a large diameter reduction rate, such as a baseball bat, the circumferential speed of the rolling drive pinion (
Due to the difference between the roll stand speed) and the average rolling speed in the rolled stock, a tendency of the workpiece to move in the longitudinal direction occurs, which places high loads on the advance drive or undesirably large Advance feeding may occur. Both of these obstacles significantly reduce rolling efficiency or product quality. For this reason, another feature of the invention is the matching of the rolling drive speed to the rolling speed of the rolls in the rolling stock. This can be achieved, for example, by superimposing and reciprocating the normally fixed racks, thereby superimposing an additional speed on the rolling speed of the pinion.

A cold pilger rolling mill for carrying out the method of the invention is driven by two planetary crank drives arranged mirror-symmetrically to each other and having horizontal axes via horizontally reciprocating connecting rods; A force and torque-compensating roll stand is provided, a rotating and advancing device for holding the workpiece during the entire rolling process is placed upstream of the roll stand, and the roll stand, together with the rolling mandrel,
It is characterized in that it is arranged on a carriage that can move into the working position and into the loading and unloading positions.

[0010] A carriage, which accommodates the rolling mandrel table and the clamping elements for the workpiece, can be moved rapidly between the loading position and the rolling position, and optionally also accommodates the devices for manipulating the workpiece. Furthermore, if necessary, the carriage is used after the deformation is complete in order to quickly pull back the clamping member of the workpiece.

In summary, a rolling mill with low mechanical and electrical costs, capable of rapid workpiece changes, and requiring only one automatic changing device for loading and unloading workpieces is desired. provided. The proposed method and rolling mill are particularly suitable for manufacturing baseball bats.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows in principle a workpiece 1 of the relevant type, for example a baseball bat, after rolling. After rolling, the workpiece is divided into three zones. Zone A is not molded. Zone B is the reduction zone, with the inner side of zone B largely corresponding to the mandrel contour and the outer side largely corresponding to the progressively tapered roll-hole type development surface, and zone C
is a cylindrical end corresponding to the contour of the rolling mandrel and the roll hole type development surface in the so-called smoothing section D. Zones E and F are zones where there is no contact between the workpiece and the rolls. If the roll is in one of these zones E and F, the workpiece is displaced by a small amount, for example 10 mm, and rotated by a predetermined angle, for example 30°.

During the entire rolling process the workpiece 1 is fixedly clamped in a clamping member 3 which is opened and closed in the loading position by means of a hydraulically actuated sliding ring 4. The clamping member 3 protects the workpiece from undesired axial movements, and the clamping member 3 transmits intermittent rotational and advancing movements to the workpiece. At this time, the rolling mandrel 2, which is fixed in the axial direction, is rotated synchronously.

In the embodiment of FIG. 2, a rolling mill having features of the invention is shown. The main motor 5 is connected via two parallel planetary crank transmissions 6 to dead center ET and AT.
The roll stand 7 is driven to reciprocate between the two. roll 8
is rotatably driven via a pinion 9 fixed to the roll shaft and a stationary rack 10 which obtains a slight reciprocating movement for speed compensation. Carriage 11 is shown in a loading position in which rolled workpieces are exchanged for blanks. The carriage 11 is basically directed towards the illustrated "loading position" or "rolling position" and the electric motor 12
to move between these two positions via . On the carriage 11 there is a rotary forwarding head 13, which is connected to the clamping member 4 shown in FIG. 14 and an electromagnetic clutch 15 following this, step rotation and step forward feed are transmitted.

The electric motor 16 quickly returns the rotary-advance head as soon as the workpiece 1 has been rolled. Both electromagnetic clutches are open in this case and during the workpiece change for rotational and forward drive. The reciprocating movement of the roll stand is not interrupted for workpiece changes. One operating cycle passes as follows. Insert and clamp the material in the loading position. The carriage 11 is advanced to the rolling position. Lock the carriage. The electromagnetic clutch is closed to energize the rotary and advance movements of the rotation-advance head and thus the workpiece. Roll the workpiece. Release the electromagnetic clutch. Release the carriage forming member. Return the carriage to the loading position and at the same time return the rotary-advance head. Release the clamp head. Unload the processed workpiece.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a workpiece after rolling.

FIG. 2 is a sectional view of the rolling mill of the present invention.

[Explanation of symbols]

1 Workpiece 2 Rolling mandrel 3 Clamping member 4 Sliding ring 5 Main motor 6 Planetary clamp transmission 7 Roll stand 8 Roll 9 Pinion 10 Rack 11 Carriage 12 Electric motor 13 Rotation-forward head 14 Step changeover transmission 15 Electromagnetic clutch A Unformed zone B Reduction zone C Cylindrical end zone D Smoothed zone E, F Zone E with no contact between workpiece and roll
T, AT dead center

Claims (4)

[Claims] 1. A tube is cold rolled by a force-driven ring-shaped roll having a working contour with a varying circumferential edge and rotatably supported in a reciprocating roll stand, during which the tube is rolled forward. In a method for producing tubular workpieces with an outer diameter and optionally an inner diameter that vary over their length by being fed and rotated about a longitudinal axis to roll workpieces of short length. the tube is fed into the rolling mill clamped at its unrolled rear end and remains clamped on the same side of the roll stand during the entire rolling process until the finished workpiece is unloaded;
For producing a tubular workpiece, characterized in that the geometry of the roll-hole mold development surface corresponds to the outer contour of the finished workpiece, and the geometry of the mandrel corresponds to the inner contour of the finished workpiece. Method. 2. A method as claimed in claim 1, characterized in that the mandrel is temporarily moved axially relative to the roll stand. 3. A method for manufacturing tubular workpieces according to claim 1 or claim 2, characterized in that the roll stand drive device also operates during loading and unloading steps of the tube and workpiece. Method. 4. A roll stand (7) driven via a horizontally reciprocating connecting rod by two planetary crank drives (6) arranged mirror-symmetrically to each other and having horizontal axes, compensating forces and torques. is provided with a rotating and advancing device (13) which holds the workpiece during the entire rolling process.
) is placed upstream of the roll stand (7) on a carriage (11) on which a rotating and advancing device (13) can travel together with the rolling mandrel (2) into the working position and into the loading and unloading position. Apparatus for carrying out the method according to claim 1, characterized in that it is located at.