JPS5985309A - Method of circulating mandrel for rolling mill - 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 The present invention relates to a method for circulating a mandrel used in a rolling mill having a restrained mandrel and used for manufacturing seamless pipes. The method of rolling using the above-mentioned constrained mandrel is referred to as a constrained mandrel rolling method, and the rolling mill using the above rolling method is referred to as a constrained mandrel rolling mill.

In the constrained mandrel rolling method described above, a blank with auxiliary holes pre-drilled in the axial direction and connected to a corresponding mandrel, that is, a perforated blank, is subsequently rolled through a plurality of rolling stands provided. This is done by passing through the road. While passing through the rolling track mentioned above, the mandrel is
tb: Restraint device driven by motive [restrained by VC.

At the end of the rolling process, after the mandrel has been removed from the corresponding tube, the mandrel is moved back across the stands by the same restraint device and is placed upstream of the first rolling stand. Grayed to initial position.

In the manufacture of seamless tubes carried out by the above-mentioned rolling mill, the surface condition, lubrication and temperature conditions of the mandrel used are extremely important, and the above-mentioned conditions of the mandrel are kept in the best condition during the rolling operation. It is well known that it is desirable to maintain the state of Therefore, it is desired that the above-mentioned three states of the mandrel be made appropriate under normal pressure.

Also, after rolling, the mandrel is returned to its initial position, and the various conditions are 1! so that a new rolling cycle for that extraction method is performed. ! It is also well known that it is impossible to become an Iko unless everything is fixed. The time required to carry out the above-mentioned process is extremely long, but it is much longer than the time required simply to roll the tube. Therefore, the working time of the rolling mill can be shortened and its rolling capacity can be fully utilized.
In addition, in order to grant the above three prefectures that are excellent in mandrel,
A system in which a mandrel is used in a circulating manner is adopted upstream of the rolling mill. The above system is equipped with a number of work stations which are used sequentially to carry out the above pipe manufacturing method well, and when this system is producing 1b, 4 to 5 mandrels are installed in the system. It is formed as 3L which circulates. By using the above system, the mandrel under the best conditions is always placed at the entrance of the rolling mill.
It is ready for immediate feeding into the rolling cycle. Therefore, according to the method of the present invention, the capacity of the rolling mill can be utilized almost completely.

Also, in the known manner, when the mandrel returns to its initial position after a rolling operation, it is hastily removed and a new mandrel is hastily placed in its place, the end of the mandrel furthest from the rolling mill being identified by the restraint device
0 A space is provided between the free end of the mandrel and the inlet of the rolling mill to accommodate the blank to be rolled. Therefore,
During two consecutive rolling cycles, the restraint device
The length of the mandrel and blank salt from the entrance of the rolling mill is about 3
0 to 35 n+), time for removal of the used mandrel, time for placing the new mandrel in position 11, time for placing the blank to be rolled in position and time for the inside of the blank. The disadvantage is that there is wasted time spent joining the mandrels.

The main object of the invention is to provide a method for circulating a mandrel in a rolling mill, which makes it possible to reduce as much as possible the wasted time between two successive rolling cycles.

In order to achieve the above object, the method of this invention is a new (2
The method comprises the step of pre-bonding a new mandrel, i.e. one mandrel which has been treated to a condition suitable for a new rolling operation, to a blank having an axial hole. This step is performed on one side of the rolling axis. To achieve the above objects, the method of the invention further comprises using a mandrel and a blank at a predetermined position on the rolling axis at the upstream side of the rolling mill when the previous rolling rifle has finished. The method includes the step of transporting the mandrel when the mandrel is removed from the location.

Next, embodiments of the method of the invention will be described with reference to an apparatus for carrying out the method. The apparatus is shown in FIGS. 1-4. The apparatus of the present invention shown in FIG. 1 is provided with a plurality of rolling stands 1 aligned along a horizontal rolling axis A, 2 being a rolling axis A K between the rolling stands l.
The mandrels are in aligned operating positions. A blank is connected to the mandrel 2, and the blank is subjected to a rolling process. This processing is performed in the same way as normal processing, so the illustration is extremely simple.

The spigot 3 of the mandrel 2 is coupled to a mandrel carrier 4 of known type coupled to the end of a rack bar 5 which grinds along the pressure+IU axis 11jA, said rack bar 5 being driven by a mortar. A plurality of objects are moved by the nohinion 6. The cough pinion 6, the rack bar 5 and the mandrel carrier 4 form a mandrel restraint device. Feeding the blank to the rolling mill by the mandrel restraint device,
After the mandrel is restrained during rolling and the rolling is completed, the mandrel is removed from the rolling mill. The details will be explained later.

Immediately after the rolling is completed, the tube 8, the mantle 1, the mantle, and the rail 2 are freely moved. The movement is carried out by a plurality of movable stands 7 (these stands are shown diagrammatically and usually 3 to 4 of them are provided), and the mandrel uncoupled from the tube 8 is moved by the mandrel restraint device 4. .5 and 6 return it to its initial position (FIG. 2). In this initial position, the mandrel 2 is supported by a plurality of rollers 9. This roller 9 is located upstream of the rolling mill, and the rolling shaft ff
It is consistent with ah. To explain in more detail, the roller 9
As in the prior art, a plurality of so-called hidden types (Di
The rack bar 5 and the mandrel carrier 4 are linearly driven along the rolling axis A.

The roller track 10 is arranged transversely to the plurality of rollers 9 and parallel to the rolling axis ilA.
1 operates between roller track io and roller 9.

3 and 4 show one embodiment of the transport arm 11. FIG. A shaft 12 is parallel to the rolling axis A and is driven to extend.
A lever 13 is coupled to the key. Lever 13 is 2
It has two arms 14 and 15, the free end of which has a rotatable bin 18 supported between bearings 16 and 17. Between the arms 14 and 15, the bin 18
A rod-shaped vertical support member 19yJX is connected to the member 19, and the vertical upper end 20 of the member 19 has a sheath-like shape with a size suitable for receiving a mandrel. A gear 21 is further mounted on the pin 18, and the core gear 2 meshes with a gear 22 rotatably mounted on the pin 23, which is mounted on the arm 14 of the lever J3. The gear 22 also meshes with an annular rack 24, which is fixed to a support member 25 and coaxially encircles the shaft 12.

As is clear from the above description, when the shaft 12 rotates, the vertical support member 19 rotates about the axis of the shaft 12 while being oriented in the vertical direction. The distance from axis 12 at which member 19 rotates is determined by the length of member 19. More specifically, the vertical support member 1g is rotationally balanced by a counterbalance member 26 formed or mounted eccentrically with respect to the axis of the shaft 12.

Rollator, Ri 10 is a cooling work area for mandrels 27V
C'L, the mandrel is conveyed to the work station 27 by means of a known conveying device, not shown here, for example a device formed using a number of levers. The cooled mandrel is conveyed from the cooling workshop 27 by a conveying device similar to the above-mentioned conveying device to a roller track 28 extending t parallel to the rolling axis alA and located on the opposite side with respect to the axis A of roller tracks 1 to 1θ. be done.

The chain conveyor 29 extending with the roller track 28 does not have to pass through the induction furnace 301 for heating the mandrel, followed by the lubrication station 31. The lubrication station is of suitable size and configured to allow a predetermined amount of force to be applied to the passing mandrel.

At the exit from the lubrication workshop, a chain conveyor 32 is provided which extends approximately parallel to the rolling axis A and approximately along an extension of the chain conveyor 29. The conveying path of the chain conveyor 32 is taken over by a roller conveyor 33 and extends further, reaching a trench adjacent to a position 34 at which the blanks with holes necessary for rolling, ie perforated blanks 35, arrive.

Between the roller conveyor 33 and the plurality of rollers 9 is a line 3 for pre-bonding the mandrel to the blank 35.
6 is provided. This line also includes a first chain section marked 37 and a following roller section 38.
is provided. This chain section 37 is formed with equipment of known type (not shown). The mandrel is gripped here and directed to the required work location.

An accumulation field 3 is located between the roller conveyor 33 and the line 36.
9 is provided. The storage area 39 serves to receive and store mandrels when the operations of the rolling mill or of the many workshops included in the mandrel circulation system disposed upstream of the rolling mill are interrupted. Of course, it is also possible to provide a mandrel travel path that bypasses this storage station 39 and to rapidly transport the mandrels.

Also, the roller conveyor 33, the accumulation layer 39 and the line 3
The mechanism for conveying the mandrels during the period 6 can be controlled to accumulate or rapidly convey the mandrels. A conveying device similar to that shown in FIGS. 3 and 4 includes a line 36 and a plurality of hidden rollers (Di
It is provided between the sappearing Rollers 9.

The method of the present invention is a method for manufacturing seamless pipes using the above-mentioned apparatus, and is particularly described below.

During rolling, the mandrel 2 is restrained in its movement by a mandrel restraint device CRe5trs,in).

The restraint device N includes a driven rack 5 and a mandrel carrier 4. The second two mandrels are placed on the roller track 10, and the following pair of mandrels 2B, 2C are in the cooling workshop 27. The other mandrel 2D is in the lubrication operation and is undergoing lubrication treatment.
The mandrel 2E after the seventh run is connected to the roller section 3 which is placed close to the entrance of the rolling mill by means of a chain section 37.
8 into the perforated blank 35.

After the rolling operation is completed, the used mandrel 2 is taken out and the mandrel restraint R4,s is placed.

6 to the initial position, where the mandrel is supported by a plurality of rollers 9. The mandrel 2 is immediately transferred from this position to the roller track 10. Simultaneously with the above operation, the mandrel 2E connected to the blank 35
are arranged on a plurality of empty rollers 9. The pivot of the mandrel 2E is automatically coupled to the mandrel carrier 4, after which the rack 5 is driven by a plurality of motors and driven by a plurality of pinions 6. In this way, a new rolling cycle is started.

Lubricated mandrel 2Df'i line 3 during rolling operation
6, and the appropriate temperature between 1 and 10'~
The mantle 2C□ cooled to 120° is transported to an induction heating furnace 30 and then sent to a lubrication workshop 31. The used mandrel 2 is cooled by the atmosphere while running along the roller track 10, and if necessary, the surface condition and the straightness of the axis are inspected. is removed from the work cycle, for example at an intermediate work station 40, and a new mandrel is supplied from a new mandrel accumulation layer 41.

At the end of the roller track 10, the mandrel 2 iJ
: After receiving the first cooling by the atmosphere, it is transported to the cooling work place 27 by water.

By joining the mandrel for subsequent rolling to the blank for the next tube while a seamless tube is being rolled, it has the remarkable effect of saving wasted time between rolling cycles. Obtainable.

The time required to transfer the used mandrel from its initial position to the rolling line 10 and the time required to transfer the mandrel combined with a previous blank to the roller line are:
In the production of seamless pipes according to the known method, the time for removing the used mandrel from the rolling line, the time for placing a new mandrel and blank on the rolling line, and the time for joining said mandrel to the blank, combined. The time required to feed the rolling mill is very short. Also, the wasted time during the rolling operation can be greatly reduced, since the return path of the mandrel carrier is shorter in the method of the present invention than in the conventional manufacturing method.

This becomes clear when considering the blank and mandrel lengths together.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of an apparatus for carrying out the method of this invention;
2 is an enlarged view of the main part of the apparatus shown in FIG. 1, and FIGS. 3 and 4 are an enlarged plan view and front view of the conveying device of the apparatus shown in FIG. 1, respectively. 1...Rolling stand, 2.2, 2B, 2C, -2D
... Mandrel, 3... Spigot, 4... Mantrel carrier, 5... Rack rod, 6... Pinion,
7...Pipe, 8...Stand, 9...Roll, 10...
...Roller track, 1...Transport arm, 12...
・1 town 11.13.14...lever, 14.15...
・Arm, 16112... Bearing, 19... Vertical support member, 27... Cooling work area, 28... Roller track, 3... Lubrication work area, 35... Perforated blank, 36... ... Line, 32 ... Chain section, 38
...rolling section, 39...accumulation place.

Claims (1)

Claims: In order to roll a blank with axial holes, a new mandrel, i.e. a mandrel conditioned for rolling, is previously connected to said blank on one side of the rolling axis. transporting the mandrel and the blank to a predetermined position on the rolling axis on the upstream side of the rolling mill, and at the same time transporting the mandrel and the blank to a predetermined position used in the pre-rolling process, which had been moved to the predetermined position at the end of the pre-rolling process. 1. A method for circulating a mandrel used in a rolling mill having a restrained mandrel for manufacturing seamless pipes, the method comprising the step of removing the mandrel from the predetermined position.