EP0072765B1 - Tool changing device on a pilgrim rolling mill - Google Patents

Abstract

1. A pilgrim-type cold rolling mill and with mobile housing, comprising a frame associated with the rolling mill which slides laterally relative to said rolling mill and thus allows withdrawal of the integral assembly of rolls and their associated mechanisms, characterized in that rocking means constituted by a cradle mounted on a spindle or on rollers, are capable of acting on the said frame with its assembly of rolls and their associated mechanisms so as to incline the plane containing the axes of the rolls until this plane reaches the desired inclination.

Description

The device and the tool change process, objects of the invention, relate to rolling mills with cold pilgrim's steps, with moving cage, intended to laminate long pieces such as tubes or bars or the like.

As explained, for example, in French patent FR 1 602 013, in rolling mills of this type, the cage supporting the rolls of the rolling mill is moved alternately with respect to the product to be rolled in synchronism with the rotation of the rolls , while the product to be rolled is intermittently advanced in the passage between the rolls. The working rolls of these rolling mills consist of rolled rolls in chocks generally carried by the cage which, moved in an alternating movement along the rolling axis, ensures by fixed racks the rotation of the rolls on the product to laminate and strictly maintains these rolls in position, by opposing by its structure the efforts to separate said rolls during rolling. These working rolls have grooves which give the laminated parts the desired shape; they are either monobloc, we will then speak of cylinders with circular grooves, or provided with grooved frets or shells coming to be fixed on a fixing block mounted permanently, we will then speak of cylinders with semicircular grooves.

In your current operation of the above rolling mills, it is necessary to be able to easily change the working rolls or their frets for example to change the dimensions to be laminated, to rectify the used grooves or to maintain the rolling mill. This change of working rolls or their frets, carried out by conventional methods is a long, delicate operation, and which has the drawback of immobilizing the rolling mill by making it unproductive for a fairly long time. This operation will be all the more dangerous for the personnel that the weight of the cylinders is important, which is the case of large rolling mills for example those capable of taking tubular blanks with an outside diameter of 200 mm whose cylinders can reach dimensions of l '' about 700 mm in diameter, the frets weighing around 500 to 700 kg.

There are already different methods of changing the rolls or their frets on existing rolling mills.

A first method consists in manually intervening on the standstill cage positioned in the rolling mill. In the case of hoop cylinders, it is then possible, without removing the cylinder block, to remove the hoops. This intervention is delicate and dangerous because of the confinement of the device, the environment linked to the lubrication of the device and the weight of the parts to be handled. In addition, since we are already working on the stand of the rolling mill, we cannot proceed simultaneously on the stand or in the vicinity of it to other operations for changing auxiliary tools, such as pipe clamps , etc ... which has the effect of extending the overall tool change time.

Another known method consists, when the rolling mill is stopped, the assembly of the two working rolls with their chocks being integral, to fix this assembly on a frame which slides laterally, relative to the rolling mill. This frame, most often permanently associated with the rolling mill, takes the assembly of the two cylinders in the rolling mill stand and after having released it from the cage, moves it laterally relative to the rolling mill. FR 1 347 991 also discloses a rolling mill, the working rolls of which are reciprocated are housed in a carriage which itself reciprocates within a fixed cage. Means are described which make it possible to separate the assembly of the cylinders from the carriage and to extract this assembly laterally through an opening provided in the fixed cage by means of two extraction rods. These different devices facilitate the maintenance of these rolling mills by allowing all or part of the working rolls to be changed outside the rolling mill stand. However, the working rolls are kept superimposed and mechanically secured one above the other as in their working position inside the cage. To have access to the lower working cylinder, it is necessary to remove the entire upper cylinder with its chocks and its tools. It is then necessary to transport to the tool shop, the assembly of the two mounted cylinders in order to change the cylinders.

The object of the present invention is an improved device making it possible to change all or part of the working cylinders even more easily, in particular in the case of cylinders comprising hoops or shells.

This invention consists of a rolling mill with cold pilgrim steps, with a movable cage, comprising a frame associated with the rolling mill which slides laterally with respect to said rolling mill and thus allows the extraction of the integral assembly of the cylinders and their annexes, means tilting constituted by a cradle mounted on an axis or on rollers being provided and arranged so as to be able to act on this frame on which is fixed all the cylinders and their annexes, so as to tilt the plane which passes through the cylinder axes until this plane reaches the desired inclination. Most often, the tilting means make it possible to tilt the plane while retaining the initial orientation of the axes of the cylinders. Preferably, the plane is tilted to the horizontal or to the vicinity of the horizontal.

The invention also relates to a process for changing rolls on a rolling pilgrim cold rolling mill, with a moving cage, according to claim 6.

The tilting means allow rotation associated or not with a translation of the plane passing through the axis of the cylinders.

When the tilting means consist of a cradle mounted on rollers, the rollers move on rails having an appropriate curvature.

• La figure 1 représente schématiquement en vue cavalière un dispositif de changement de cylindres par montage sur un bâti coulissant de l'art antérieur.
• La figure 2 représente en coupe perpendiculaire à l'axe de laminage un dispositif selon l'invention.
• La figure 3 représente le même dispositif en vue latérale, selon l'axe XX' de la figure 2 du dispositif de basculement, les axes des cylindres se trouvant dans un plan vertical avant basculement.
• La figure 4 représente le même dispositif en vue latérale et en coupe par le plan médian AA de la figure 2 après basculement du bâti, les axes des cylindres de travail étant alors dans un plan horizontal pour changement des frettes.

The figures and the example below describe in a nonlimiting manner a particular embodiment of the invention.

• FIG. 1 schematically represents in a side view a device for changing cylinders by mounting on a sliding frame of the prior art.
• Figure 2 shows in section perpendicular to the rolling axis a device according to the invention.
• Figure 3 shows the same device in side view, along the axis XX 'of Figure 2 of the tilting device, the axes of the cylinders being in a vertical plane before tilting.
• 4 shows the same device in side view and in section through the median plane AA of Figure 2 after tilting of the frame, the axes of the working rolls then being in a horizontal plane for changing the hoops.

In FIG. 1, there is a rolling mill (1) with pilgrim steps comprising a cage, the uprights of which are seen in (2 and 3), two working rolls (4 and 4 ') with their chocks (5-5'-6 -6 ') and their rotational drive gears (7-7'). The two cylinders (4-4 ') and their chocks (5-5'-6-6') are joined in known manner by rods and bolts. We see in (6A) the housing of the heads thereof. In this figure, all of the cylinders (4-4 '), their chocks (5-5'-6-6') and their drive sprockets (7-7 '), came out of the cage of the rolling mill (1) and fixed on a frame (8) which slides laterally with respect to the whole rolling mill (1) according to the prior art. This device makes it possible, after having raised the front rack (9) to exit the roll stand (1) fairly easily all of the two cylinders (4-4 ') and their annexes. We see however that to have access to the lower cylinder (4) and its chocks (5, 6), it is necessary to remove the upper cylinder (4 ') and its annexes (5', 6 ', 7'). The area in which the assembly of the two rolls is then does not allow, in view of the general mechanical design of the rolling mill, which is very dense in this part adjacent to the rolling mill proper, to make complex and multiple handling operations such as for example the provisional deposition of the upper cylinder. The solution then consists, taking into account the delicate problems posed by the adjustment of the two superimposed cylinder blocks to transport the assembly (4-4 ') with its annexes (5-5'-6-6'-7-7') in the tool shop. However, the handling of such an assembly is made difficult by its very large mass which, for a large rolling mill can be of the order of 8 to 10 tonnes.

In Figures 2, 3 and 4, there is shown a rolling mill with cold pilgrim steps (10), comprising a cage (11), equipped according to the invention. The assembly of the two working cylinders 12-12 ') of their chocks (13-13'-14-14') and their rotational drive pinions (15-15 ') is mounted on a frame (16) , which can itself be secured with a cradle (17), mounted on a horizontal axis (18) parallel to the axes of the working rolls and therefore perpendicular to the rolling axis. This axis (18) allows the cradle (17), the frame (16) and the set of two cylinders (12-12 ') with their annexes, to pivot by rotation in a vertical plane parallel to the rolling axis , that is to say the axis of movement of the parts to be laminated, the axes of the cylinders (12-12 ') retaining the same orientation.

We see Figures 3 and 4, that this device is particularly advantageous for rolling mills whose cylinders (12-12 ') work only by rotation of a half-turn and whose, consequently, the working grooves (19-19 ') can be traced on removable frets (20-20') in the form of half-shells. These frets (20-20 ') then constitute wearing parts which can be replaced relatively frequently and easily. Their weight is low compared to the whole, of the order of 500 to 700 kg per half-shell. In the horizontal position of the cradle (17), as shown in FIG. 4, the two relatively light hoops (20-20 ') can be manipulated both by a simple service bracket (P) of capacity less than one tonne. The two frets, lower (20) and upper (20 ') can be changed on site without having to dismantle the entire upper cylinder (12') and its annexes. The adjustment and setting of the two frets (20-20 ') is done in relation to the shafts (21-21') of each of the working cylinders (12-12 ') without having to move or adjust the relative position of the shafts (21-21 ') themselves, nor the rest of the cylinders (12-12'). The work of changing the frets (20-20 ') and their annexes is greatly facilitated.

The lateral drive device for the frame (16) is shown diagrammatically in FIG. 2 by a telescopic jack (22). The frame (16) also comprises a jack (23) actuating a device of inclined shims which allows, according to a known technique, to release all of the cylinders (12-12 ') and their annexes when they are taken to take them remove from the stand (11) of the rolling mill (10).

The device for tilting the frame (16) by the cradle (17) is designed so as to take advantage of the little space available and not to hinder the passage of the mechanical devices of the rolling mill. Thus a bore (24) in the base (25) is provided to allow the passage of the shaft controlling the rotation of the product to be laminated.

Thus, the rolling mill kinematics control assembly (rolling kinematics, rotation kinematics, advance kinematics) as well as the entire tool change device is located on the same side of the rolling mill relative to the plane vertical passing through the rolling axis, thus completely freeing the other side.

The device for controlling the rotation of the cradle (17) around the axis (18) is not represented. It can be carried out in various ways well known to those skilled in the art. It is also understood that the frame (16) is designed in such a way that it can successively move laterally, to ensure the extraction of the integral assembly of the cylinders, from the stand (11) of the rolling mill (10) , then freely tilt with the cradle (17).

To support the chocks (13-13'-14-14 ') during the tilting of the cradle (17), as shown in Figures 3 and 4, said cradle (17) has a side face (26).

At the end of the race, the face (26) of the cradle (17) comes to bear on a stop (27). The use of the device is easily understandable by examining FIGS. 2, 3 and 4. For an operation, for example changing the hoops (20-20 '), one begins by raising the rack (28). The chocks (13-13'-14-14 ') are held together 2 to 2 by connection means not shown. We advance the frame (16) under the cylinders (12-12 ') and the lower chocks (13-14). The set of cylinders is released from the cage (11) by the action of the jack (23). By the action of the jack (22), the set of cylinders (12-12 ') and their annexes resting on the frame (16) are removed laterally in the direction of the arrow F, as shown in FIGS. 2 and 3. When the frame (16) is sufficiently spaced apart, and that the cylinders (12-12 ') are located above the cradle (17), the latter is tilted around its axis (18) which rotates the assembly frame (16) and cylinders (12-12 '). It can be seen in FIG. 4 that, at the end of the race, the axes of the cylinders (12-12 ') are in the same substantially horizontal plane, the cradle (17) being in abutment on the stop (27). It is thus easy to carry out any operations for changing the frets (20-20 '). Finally, the two cylinders (12-12 ′) and their annexes are replaced in place in the rolling stand (11) by reverse operations of tilting the cradle (17) then translating the frame (16).

Thus, in the case of a rolling mill with pilgrim steps incorporating the device which is the subject of the invention, making it possible to produce finished tubes with an outside diameter of 150 mm, it has been found that, for cylinders comprising frets in half-shells 700 mm outside diameter, the overall tool change time (this time including the change of auxiliary tools, such as the pipe clamp) is approximately halved compared to the time required to perform the same operations for a conventional rolling mill, according to one or other of the techniques described in the prior art.

Although the invention has been described in a particular case, it will be applied to any rolling mill with cold pilgrim steps, with a movable cage, using such devices. This is the case if for example the rolling mill has in addition working rolls, support rolls or if the working rolls have several grooves distributed over the length of the table.

Claims (7)

1. A pilgrim-type cold rolling mill and with mobile housing, comprising a frame associated with the rolling mill which slides laterally relative to said rolling mill and thus allows withdrawal of the integral assembly of rolls and their associated mechanisms, characterized in that rocking means constituted by a cradle mounted on a spindle or on rollers, are capable of acting on the said frame with its assembly of rolls and their associated mechanisms so as to incline the plane containing the axes of the rolls until this plane reaches the desired inclination.

2. A pilgrim-type rolling mill according to Claim 1, characterized in that the rocking means allow the plane containing the axes of the rolls to be inclined while maintaining the initial orientation of the axes.

3. A pilgrim-type rolling mill according to Claim 1 or 2, characterized in that the rocking means allow the plane containing the axes of the rolls to be inclined until it reaches the horizontal.

4. A rolling mill according to one of Claims 1 to 3, characterized in that the base carrying the cradle is pierced by a bore enabling the passage of the shaft governing the rotation of the product to be rolled.

5. A rolling mill according to one of Claims 1 to 4, characterized in that the assembly of mechanical devices of the rolling mill, namely rotary drive means, forward drive means and rolling drive means, as well as the device for rocking the integral assembly of rolls are situated on the same side relative to a vertical plane passing through the axis of rolling.

6. A process for changing rolls on a pilgrim-type cold rolling mill with mobile housing in which the assembly of rolls and their associated mechanisms is withdrawn from the rolling mill housing by translation of a frame, characterized in that, after translation, this frame, with its assembly of rolls and their associated mechanisms is connected to rocking means constituted by a cradle (17) mounted on a spindle (18) or on rollers, then these rocking means are actuated to incline the plane containing the axes of the rolls until this plane reaches the desired inclination in particular the horizontal, and in that one then effects the necessary dismantling followed by repair or replacement of the roll bands, and re-assembly of these bands and in that, after re-assembly, the rocking means are used to return to the vertical the plane containing the axes of the rolls and the assembly of rolls and their associated mechanisms is put back into the rolling mill housing by translation of the frame.

7. A process according to Claim 6, characterized in that the rocking means allow the plane containing the axes of the rolls to be inclined while maintaining the initial orientation thereof.

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