HK1002175B - Automatic drawing device - Google Patents

Description

The field of invention

The invention relates to a stretching device according to the preamble to claim 1 and thus to the field of shaping materials by stretching or threading to reduce, in one or more stretching steps, the dimensions of long metal objects, typically tubes.

The state of the art

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In addition, US-A-1,911.157 describes a stretching device according to the preamble to claim 1 comprising, upstream and downstream, a thread or bar pushing device in a loop, a stretching loop and a pulling device consisting of continuous chains with three gripping heads, regularly spaced so that one gripping head is always active to pull the said thread or bar.

The problems

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The applicant therefore sought and developed a device which would simultaneously: * increase the productivity of stretching* limit investment costs* integrate finishing and trimmings with stretching.

The invention is described in detail in the following table:

According to the invention, the stretching device of a long metal product comprises a stretching block, a device for attaching the long metal product to the stretching block, a traction device for the long stretched metal product, and is characterized by the fact that, (b) the said coupling device, located downstream of the said coupling block, includes an automatic coupling device from the pointed end of the said coupling block extended from the exit of the said coupling block to the exit of the said coupling device.

The invention will be better understood by means of figures which represent only one mode of the invention.

The following is a description of the figures:

Err1:Expecting ',' delimiter: line 1 column 170 (char 169)and the means of cutting (32) fed into baskets (6) of stretched tubes for the production of lengthened and conditioned stretched tubes (35), the empty baskets (6) being then loaded with tube drafts (39) (from upstream stretching machines) to be stretched and directed to the means of stretching.Figures 3, 4, 5, 6 and 7 are cut-out views, in a vertical plane, of a mode of manufacture of the automatic stretching device according to the invention illustrating the automatic engagement phase of the length produced (2) from the outlet of the line (10) of the stretching block (7) to the outlet (33) of the traction medium (16) or LT comprising two traction lines (17) defining a long traction (18).- What? The automatic stretching device consists of a stretching block (7), a cooling block (12) and a traction device (16) in line. The stretching block (7) comprises a stretching line (10) and possibly a notch generator (37) - only shown in Figure 3 to avoid overloading the figures. The cooling unit (12) comprises washing and cooling ramps (13) and a wiping box (14).The corresponding figures 3a, 4a, 5a, 6a and 7a complete the previous ones. the invention,in particular the guidance devices (24) of the DEA comprising a means of attachment (21) solid to the end of a steel tape (20) constituting the said traction auxiliary.Figures 3 and 3a represent the initial state of the automatic pulling device before the DEA is started (19): the end (4a) of the tip (4) is beyond the pulling outlet (7) and the DEA (19) is not activated: the means of attachment (21) is held slightly away from the exit (33) of the traction device (16).Figures 4 and 4a represent the activation of the DEA, i.e. the positioning of the DEA (19) (23) by means of the pulling outlet so that the means of attachment (21) is moved slightly away from the traction device (16).Figures 5 and 5a show the reverse movement of the DEA of the traction device (16): the gripper (21) passes through the traction device (16) and the cooling unit (12), pushing the wiper box (14) made of scraper seals, also guided by the guide devices (24), against the stretch line (10), and automatically grips the end (4a). There are guides (24) between the exit of the stretch block (7) and the entrance of the traction device (16). There are guides (24a) at the exit (33) of the traction device (16), as shown in Figures 3a,Err1:Expecting ',' delimiter: line 1 column 534 (char 533)- What? In the maximum forward position, the steel strip comes down the curve to the storage position.Figures 6 and 6a illustrate the next step in which the traction device (16) is turned on forward: the stretched product (2a) is pulled through the line and then through the cooling block (12) and drives the wiper box (14) to the cooling block, while the traction auxiliary (20) returns to the position it had in Figures 4 and 4a, the rocking device (21) then being out (33) of the traction device (16), while the other end of the traction auxiliary (20) is attached to the veranda (23) by means of guides (24a).Err1:Expecting ',' delimiter: line 1 column 432 (char 431)The hook (21) also carries guide nipples (36) in the guide rails (24).Figure 8a is a side view of the hook (21).The upper part is occupied by the cams (not shown), and the right part secures the low-thickness steel tape (20) by means of the hook (21). The exit ramp (41) of the guide channel (40), is shown in dots.Figure 8b is an upper view of a pair of cams (22) whose active surface is equipped with teeth (22a) oriented so that the tip (4) of the long product to be drawn is not likely to slip and become loose from the means of attachment when the product is pulled on.Err1:Expecting ',' delimiter: line 1 column 329 (char 328)and possibly the lubricants of the stretch tubes.Figure 11 shows a stretch line (31) consisting in series of: * a diversion set (5) with 8 baskets (6) containing the long products (2) to be stretched,* a first stretching device (1) with a stretching block (7), a cooling block (12), a traction device (16) and an automatic engagement device (19) not shown in the figure, forming the long stretched product (2a),* a control system (27),* a second stretching device (1a) similar to the first, forming the long stretched product (2b),* a second control system (27a),* a third stretching device (1b) similar to the previous ones,The product is then cut into a single piece of fabric, which is then cut into a single piece of fabric, and the product is then cut into a single piece of fabric, which is then cut into a single piece of fabric.

The manufacturer shall provide the manufacturer with a detailed description of the device.

The generic means of the invention may take several concrete forms. Depending on the possible device, the automatic coupling device (19) shall include: (a) an auxiliary traction device (20) of limited length with one end solidary to an automatic coupling/uncoupling device (21), such that, when the said coupling is fixed at the said edge of the long product (2) leaving the said stretch block, the said auxiliary traction device is connected by its other end with the said traction device. It may also pass through the said traction device (16) on its entire length and its other end is beyond the said traction device (16). (b) the said traction device (24) guides the said traction device (20), on all or part of the exit of the said traction device (7) before the said traction device (16) and before the said traction device (21) and may also include a secondary traction device (20) and a traction device (20) by moving the said traction device (16) and by moving the said traction device (21).

Figures 3 to 7 and 3a to 7a illustrate in detail the automatic stretching device according to an embodiment of the invention, which comprises, on the one hand, the means of stretching: stretching block (7), cooling (13) and traction device (16) and, on the other hand, an automatic engagement device (19) integrated into these means of stretching.The purpose of the invention is not only to solve the problems already described but also to produce long stretched products, mainly but not exclusively tubes, with excellent surface condition - which excludes many traction devices which injure and mark the surface of the long stretched product. The applicant concluded from its tests that all the problems raised, both economic and of quality, could be solved only by coupling a traction device based on the use of close-fitting driving belts which enclose the product and stretch it over a length sufficient to exert the traction force and to pull it by simple pressure of the driving belts without injuring it,This required an automatic coupling device which would allow the long product to be stretched to the exit (33) of the traction device (16).

The automatic engagement device (19) of the invention may also include various special means of implementation. Thus, the said auxiliary means of traction (20) is chosen in such a way that, when moving forward, it has sufficient traction resistance to be able to pull the said long product (2a) from the exit of the said stretch block (7), through the said cooling block (12), to the exit of the said traction device (16), and, when moving rearward, it has sufficient compression resistance so that, by means of the said guiding means (24), the said automatic means of attachment/unfastening (21) can be moved to the exit of the said stretch block (7).

Preferably, the said auxiliary means of traction (20) is a steel band whose lateral positioning is provided by rails which constitute the said means of guidance (24). But this steel tape can be replaced by any other device for transmitting movement and force, for example a cable inserted into small cylindrical sleeves, or again for example a tape in the form of portions of articulated bars, or a chain formed of articulated links.

When the traction auxiliary (20) is not activated, it shall be positioned, out of the traction device (16), by means of a guide (24a) and parking device for the traction auxiliary (20) and the coupling device (21).

To activate or deactivate the automatic coupling device (19), i.e. to present or to deflect the means of attachment to the exit (33) of the traction device (16), the secondary means (23) may be a cylinder (23) as shown in Figures 3 to 7, or a drive shaft or any other equivalent means.

Preferably, the automatic means of attachment/unfastening (21) shall consist of two cams (22) with oriented teeth allowing the attachment of the said end of the long product (2) to be sharpened as and as long as the automatic means of attachment/unfastening (21) exerts a pull on the said end when moving forward.

Preferably, as shown in Figure 8b, the cams (22) have a logarithmic spiral profile so as to apply pressure on the tip in proportion to the tensile strength, and this is the case for tube manufactures whose diameters may vary over a fairly wide range.

The retractor according to the invention may include a cooling unit (12) to which a wiper box (14) is attached. This wiping box (14) with its central opening suitable for the product being stretched (2a) can be moved by means of the above-mentioned guides (24) and by pushing the above-mentioned means of attachment (21) until the said stretching block (7) comes out. A cooling block (12) is not in itself necessary to implement the invention, but, in view of the need to apply a traction to the long-stretched metal product without injuring it, it is preferable to use, for the drive belts of the traction device (16), low abrasive materials,In this case, it is important to cool the long-stretched metal product, typically by spraying it with cold water, and wipe it before it entangles itself between the close-fitting drive belts. According to the invention, the said traction device (16) is a belt or track device (17), which can exert a traction force over a sufficient length LT (18), typically 1 to 3 m depending on the required traction forces and the frictional forces between the long stretched product and the said belts, without injuring the long stretched products.- What? For example, drive belts consist of bands of elastomeric or rubber material held together by pressing rollers and/or motors. Drive belts (17) could also be replaced by a succession of pairs of rollers with an equivalent function, provided that the traction length LT (18) between the drive belts and the long-stretched product is sufficient to exert the necessary tensile force for stretching without damaging the surface of the long-stretched product.

As shown in Figure 3, the device according to the invention may, in the case of tube stretching, include, at the exit of the stretching block (7), a means (37) to form a notch (30) to reduce the inner diameter of the tube and, when starting, facilitate the installation of the appropriate chuck for each line. The medium (37) shown in Figure 3 corresponds to two cams, the rotation of which leads to the formation of a notch (30), of the type shown in Figure 10.

The purpose of the notch (30) is to allow the smallest diameter of the chuck (11) to be engaged in the notch (10); in the absence of a notch (30), there would be a risk of the chuck slipping. This notch is only made at the tip (4) of the tube to be stretched as it is an intermediate stretch pass, since the notch made when the tube tip is engaged is intended to allow the chuck to be engaged in the next stretch pass, as will be explained in the following.

The retractor of the invention may include means for automating the sequential implementation of the various movements enabling the implementation of the said automatic engagement means: (a) reversing the secondary means (23) so as to present the said coupling (21) at the exit of the traction device (16), (b) stopping the said secondary means as soon as the said traction device (16) is reversed, (c) reversing the traction device (16) until the said coupling (21) has gripped the said end of the said long product (2), (d) starting the front of the traction device (16), and possibly automatically, by means of a notch generator (37), making a bend (30) after the said end has been moved over a predetermined length, (e) and, when the said coupling (21) is placed at the said traction device (16), temporarily starting the said secondary means (23) to access the said traction device (21) (16).

The means of automation used are known in themselves and may possibly be supplemented by any type of sensor, typically a long product presence sensor, a speed sensor, a temperature sensor, allowing a reliable implementation of the stretching device according to the invention.

It is possible to make a stretch line (31) with as many of the invention's stretch devices as the one described above as desired stretch passes in series, and this line includes, between two successive stretch devices, a control (27) to guide the long stretched product (2a) to the input of the next stretch block (7a), to a switching station or to any other processing station for the stretched tube. In a manner illustrated in Figure 9, the control device (27) allows the formation of a loop (28) of the long-stretched product, and includes means of movement (29), typically motor rollers between which the long-stretched product passes at the end of the loop, and a loop position sensor (27a). Although Figure 9 shows the long-stretched product entering and exiting the said loop as linear, the loop control device (27) actually allows the long-stretched product to be directed out of the loop in the desired direction, as clearly shown in Figure 11.

It is therefore possible to series several drawing devices according to the invention, typically 3 to 5, ordered by decreasing thread diameter and to form a drawing line (31) according to the invention, as shown in Figure 11. A system of synchronisation of these devices is necessary, in particular because the linear speed of the long stretched products increases at the output of each line.This synchronisation system allows a sequence of stretching passes with different lengths to be achieved (e.g. 160% stretching in first pass, 130% in second pass, etc.), unlike the previous stretching systems which are designed for a given stretching range only.

The stretch line (31) therefore generally comprises means of controlling the position and speed of the long product (2, 2a, 2b...), means of controlling the diameter of each control loop (28), means of synchronising the different linear speeds of the said long products stretched out from each stretch block by playing on the speed imposed on the traction devices (16) and/or the means of movement (29), so that there is neither accumulation nor excessive tension of said long products stretched between two successive stretch blocks (7,7a).

The invention may be used for stretching products into crowns, such as tubes, wires or rods. The invention may also be used for stretching straight metal products, such as bars and tubes.

Example of implementation

A complete stretch line (31) was made as shown in Figure 11. This line (31) comprises 3 stretching devices (1,1a,1b) followed by a switching station (32) which delivers packaged tube heads (35) ready for marketing. It made it possible to increase the diameter of the tube from 18 mm to 9.52 mm in three stretch steps.

This line is fed by baskets (6) of tubes to be stretched.

Each stretcher (1,1a,1b) shall consist in series of a stretcher block (7,7a,7b), a cooling block (12,12a,12b) and a traction device (16,16a,16b) with a crawler fitted with straps (17) typically made of rubber.

Between two stretching devices (1 and 1a, 1a and 1b) a looped adjustment device (27,27a) allows in particular to orient the stretched tube in the desired direction and to ensure the necessary flexibility between two successive stretching devices, so that there is neither local accumulation nor lack of stretched tube. Line (31) includes means of guiding the stretched tube which is all along the line and under constant position control - except at the loop (28) of the control device (27) for shock absorption. The automatic control and timing system of the line, which is known in itself, is not shown in Figure 11.

The operation of this stretch line can be described as follows: * for each basket of tube crown to be stretched, the operator must make a tip as shown in Figure 10 by means of a device designed for this purpose, having first placed 3 cylinders (11,11a,11b) suitable for the 3 stretching lines (10,10a,10b) not shown. He must make a notch (30).* He must manually introduce the end (4a) of the tip (4) of the tube into the first line (7).* Then he simply starts the line according to the invention so that all operations will proceed automatically to the switching station.

Generally, the tip preparation can be done in masked time, so that overall in this example the average productivity for simultaneous production of the last 3 stretching passes and the cutting is between 150 and 250 m/min (effective speed), for a maximum speed of about 400 m/min in this example, but it can be greater than 1800 m/min.

The advantages of the invention

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It is important to note that, in the case of the state of the art, the switching is a separate operation, not integrated as on the line (31) of the invention, which has both a great reduction in handling and labour costs, and also eliminates the risk of damage to the tubes. The possibility of integrating the cutting (or any other processing or finishing operation of the stretched tube) into the stretching of the tube results from the fact that the invention allows total guidance of the long stretched product, the trajectory of the long stretched product being perfectly defined, and can be compared to a broken line, each change of direction being carried out by a control device (27) with a long stretched product loop (28). However, the state-of-the-art stretching method, which transforms one tube crown into another tube crown stretched, did not allow the integration of the cutting operation - of any other operation - into the tube stretching.

In addition, at the same production, the cost of a line (31) in the example is about four times less than that of the corresponding state-of-the-art equipment including the stretching and cutting means, and if the floor space of a line (31) in the example is compared with that of the state-of-the-art equipment in Figure 2, this space is about twice less with a line (31) in the invention.

The invention is not limited to the example of a stretch line, but allows for the modular design of a stretch line to provide various possibilities. e.g. the tube stretch passes can be made with 2 lines of 4 stretch devices each, the second and last line including the switching station.

Finally, the invention makes it possible to guarantee, by integrating the switching station with the stretching line (integration which was not possible with the stretching devices according to the state of the art), the production of long stretched products with a high surface quality.

Claims (19)

1. Drawing device (1) for a long metallic product (2), comprising a drawing block (7), a device engaging the said long metallic product (2) into the said drawing block (7), a pulling device (16) pulling the said long drawn metallic product (2'), characterized in that,

   a) the said pulling device (16) comprises two nearby motor driven belts rotating in opposite directions which move the said long drawn metallic product (2') linearly.

   b) The said engagement device on the outlet side of the said drawing block (7) comprises a device for automatic engagement (19) of the tapered end (4a) of the said long drawn product (2') from the exit from the said drawing block (7) to the exit from the said pulling device (16).

   c) The said automatic engagement device (19) comprises an auxiliary tension means (20), moved by the said pulling device (16).
2. Device according to claim 1 in which the said automatic engagement device comprises:

   a) the said auxiliary tension means (20) of limited length, one end of which is fixed to an automatic attachment / detachment means (21), the said length being such that, when the said attachment means is fixed to the said tapered end of the said long product (2) output from the said drawing block, the said auxiliary tension means is gripped at its far end by the said pulling device (16),

   b) guidance means (24) in the said auxiliary means (20), over all or part of the trajectory from the exit from the said drawing block (7) to the exit from the said pulling device (16), and at the exit from the said pulling device (16),

   c) means of displacement forward and back of the said auxiliary means (20) comprising the said pulling device (16).
3. Device according to claim 2 in which the said displacement means in front and behind also comprise secondary means (23) for displacing and gripping or separating the said attachment means (21) with the said pulling device (16) at its exit.
4. Device according to any one of claims 2 to 3 in which the said auxiliary tension means (20) is chosen so as to present a sufficient tension resistance in forwards displacement to be able to draw the said long product (2a) from the exit from the said drawing block (7) through the said cooling block (12), to the exit from the said pulling device (16), and in reverse displacement to have sufficient compression strength so that, due to the said guidance means (24), the said automatic attachment / detachment means (21) may be displaced to the exit from the said drawing block (7).
5. Device according to claim 4, in which the said auxiliary tension means is a steel strip (20), which is laterally positioned by rails which form the said guidance means (24).
6. Device according to any one of claims 3 to 5 which comprises a guidance means (24a) and a storage means for the said auxiliary tension device (20) and the said attachment means (21), at the exit from the said pulling device (16).
7. Device according to any one of claims 2 to 6 in which the said secondary means (23) is a motor spindle or a jack.
8. Device according to any one of claims 2 to 7, in which the automatic attachment / detachment means (21) is composed of two cams (22) with oriented teeth capable of gripping the said tapered end of the said long product (2) as soon as and as long as the automatic attachment / detachment means (21) exerts tension on the said end in forward displacement.
9. Device according to claim 8, in which the profile of the said cams (22) has a logarithm shape so as to exert pressure on the said end, proportional to the tension, for manufacturing tubes with diameters varying within a fairly wide range.
10. Device according to any one of claims 1 to 9 comprising a cooling block (12), which is used together with a wiping box (14).
11. Device according to claim 10, in which the said wiping box (14), the central orifice of which is adapted to the drawn product (2a), can be translated using the said guidance means (24) and by the thrust of the said attachment means (21), as far as the exit from the said drawing block (7).
12. Device according to any one of claims 1 to 11, in which the said pulling device (16) is a tracked device.
13. Device according to any one of claims 2 to 12, for use for drawing tubes and comprising a means of forming a notch (30) at the exit from the drawing block, to reduce the inside diameter of the said tube and, when starting, to facilitate placement of the mandrel adapted to each die.
14. Device according to any one of claims 2 to 13 which comprises means of automating sequential implementation of the various movements enabling use of the said automatic engagement means:

    a) Start reverse motion of the said secondary means (23), so that the said attachment means (21) appears at the exit from the pulling device (16),

    b) and stop the said secondary means as soon as the said pulling device (16) starts its reverse motion,

    c) start reverse motion of the pulling device (16) until the said attachment means has gripped the said tapered end of the said long product (2),

    d) start forward motion of the pulling device (16), and possibly automatically make a notch (30) after displacement of the said end on a given predetermined length,

    e) and when the said attachment means (21) reaches the exit from the said pulling device (16), start temporary forward motion of the said secondary means (23) to move the said attachment means (21) away from the exit from the said pulling device (16).
15. Drawing line, comprising one drawing device in series according to any one of claims 1 to 13, for each of the required number of drawing passes, including a regulation system (27) between two successive drawing devices, providing guidance for the said long drawn product (2a) towards the entrance into the next drawing block (7a) or to a cutting or other station.
16. Drawing line according to claim 15, in which the said regulation system enables the formation of a loop (28) of the said long drawn product, and comprises displacement means (29).
17. Line according to either of claims 15 and 16, comprising means for checking the position and speed of the said long product (2, 2a, 2b, etc.), means of checking the diameter of each regulation loop (28), means of synchronizing the various linear speeds of the said long drawn products at the exit from each drawing block by varying the speed imposed on pulling devices (16) and/or displacement means (29), such that there is no accumulation or excessive tension in the said long drawn products between two successive drawing blocks (7, 7a).
18. Use of the device according to claims 1 to 14 or the line according to claims 15 to 17 for drawing metallic products in reels (wires, tubes, bars).
19. Use of the device according to claims 1 to 13 for drawing straight metallic products (bars, tubes).