Pitch adjustment device and method for a cooling bed

Abstract

 The present invention concerns a pitch adjustment method and device for adjusting the pitch of a cooling bed (100) configured for cooling rolled products (200), said cooling bed (100) comprising a plurality of mutually spaced stationary rakes (101) with cyclically movable carryover rakes interspaced there between, each rake comprising evenly spaced teeth (103) characterized by a nominal pitch (L) and configured for supporting said rolled products (200), said pitch adjustment device comprising:
- a movable tooth (1);
- means for moving said movable tooth (1);

and being characterized in that the movable tooth (1) is able to push laterally a rolled product (200) lying on the cooling bed (100).

Description

[0001] The invention relates generally to material handling equipment of longitudinally hot rolled products of a rolling mill and in particular to cooling bed for progressively laterally transferring such products from a run-in table at the exit of the rolling mill to a further processing equipment, wherein said products undergo cooling during their lateral transfer.

[0002] Conventional cooling beds have mutually spaced stationary rakes or rests with cyclically movable carryover rakes or rests interspaced there between, wherein the stationary rakes and the movable rakes are usually toothed rakes, i.e. tooth-shaped rakes. Such cooling beds consisting of alternately fixed and movable rake-shape rests are also called rake-type cooling beds. Generally rolled products exiting a finishing section of the rolling mill are longitudinally transferred to a run-in table where they are decelerated before to be dropped onto the spaced rakes of the underlying cooling bed for undergoing a cooling during their lateral shift along the transfer direction from the cooling bed entry to a discharge side. A movable rake mechanism moves cyclically and simultaneously the movable rakes for transporting products in a phased manner from the entry of the cooling bed downstream to the discharge side wherein the products are further processed. The movable rake mechanism is usually driven through driving means, like motors or hydraulic means, driving parallel sets of drive shafts for moving the movable rakes in said phased manner, each rake performing a movement identical to the movement of the other rakes. Each driving mean may transmit drive through worm reduction gear drives. Each shaft incorporates eccentrics, which provide a two-axis movement to the movable rake mechanism, and therefore to the movable rakes which are cyclically lifted above the stationary rakes from an initial position, then displaced in the direction of the discharge side, and then lowered under the stationary rakes and brought back to the initial position. During the raising of the movable rakes above the stationary rakes, products which were lying on a first position on the stationary rakes and supported by the stationary rakes are simultaneously taken in charge by the movable rakes which lift them above the stationary rakes, then displaced them in the direction of the discharge side, and lowered them until they lay again on the stationary rakes on a second position downstream the first position, the movable rakes going then back to their initial position for repeating the movement. Consequently, products lying on the stationary rakes are cyclically and in phase stepwise conveyed over the stationary rakes towards the discharge side through the raising and advancement of the movable rakes.

[0003] Cooling beds are generally designed considering the smallest and the maximum size of the rolled products delivered at the finishing section of the rolling mill as well as the cooling time required for cooling said rolled products. The maximum size product defines generally the pitch of the rake, i.e. the distance between the evenly spaced rake teeth, so that the space between two teeth may receive only one product. This means that rolling large products requires large cooling beds. In order to avoid the extension of the size and weight of the cooling beds while being able to cool down large products, it is possible to process large products over several pitches. Unfortunately, handling lengthened products whose widths are very close to the pitch size implies an instable position of the rolled product on the rakes, and consequently the position of the rolled products on the cooling bed cannot anymore be predicted or known due to the random position and orientation of the rolled products extending over the several pitches. For example, a rolled bar whose width equals the pitch size might be misaligned on the cooling bed, i.e. one extremity of the bar might lie on a tooth and the other extremity on a slot separating said tooth from another tooth. The lack of control and uncertainty on the position and orientation of the rolled products on the cooling bed makes their further processing more complex, making for example their discharging onto a runout rollerway difficult, or requiring an additional counting and separating system in order to exactly provide a downstream equipment with a correct number of rolled products positioned according to a predetermined orientation.

[0004] An objective of the present invention is to overcome the above-mentioned problems by providing a device and a method for a cooling bed that allow to handle in a controlled manner the position on said cooling bed of various rolled products characterized by various widths, smaller, equal, and larger than the pitch of the cooling bed rakes, so that the position and orientation of the various rolled products is correct on the cooling bed (i.e. the rolled products are mutually aligned and perpendicular to the cooling bed rakes) and might be predicted/predetermined at the discharge side of the cooling bed.

[0005] The present invention achieves the above-mentioned objective by the features of a pitch adjustment device designed for equipping a cooling bed configured for cooling rolled products, said cooling bed comprising a plurality of mutually spaced stationary rakes with cyclically movable carryover rakes interspaced there between, each rake comprising evenly spaced teeth characterized by a nominal pitch and configured for supporting said rolled products, said pitch adjustment device comprising:

• a movable tooth;
• means for moving said movable tooth;
  and being characterized in that the movable tooth is able to push laterally, preferentially according to a direction opposed to the transfer direction of a rolled product on the cooling bed, and in particular over a predetermined pushing distance, a rolled product lying on the cooling bed.

[0006] The present invention also concerns a pitch adjustment method for adjusting the pitch of a cooling bed comprising a plurality of mutually spaced stationary rakes with cyclically movable carryover rakes interspaced there between, each rake comprising evenly spaced teeth characterized by a nominal pitch and configured for supporting said rolled product, said pitch adjustment method comprising the following steps:

• determining an adjusted pitch, preferentially automatically and/or by means of a controller 5 and from a rolled product section width and said nominal pitch;
• adjusting a position of a movable tooth 1 in function of said adjusted pitch, notably by using means for moving said movable tooth, and in particular before or during the working process of the cooling bed. The adjustment of the position of the movable tooth 1 might be automatically done, and is in particular controlled by the controller 5;
  characterized in that the adjustment of the position of said movable tooth is done according to a movement configured for pushing laterally a rolled product lying on the stationary rake, preferentially according to a direction opposed to the transfer direction of a rolled product on the cooling bed, and in particular over a predetermined pushing distance.

[0007] Finally, the present invention also concerns a cooling bed for cooling rolled product at an exit of a rolling mill, said cooling bed comprising a plurality of mutually spaced stationary rakes with cyclically movable carryover rakes interspaced there between, each rake comprising evenly spaced teeth characterized by a pitch L, the cooling bed according to the invention being characterized in that it comprises the previously described pitch adjustment device.

[0008] Other objectives, features and advantages of the present invention will be now described in greater details with reference to the following drawings:

Figure 1

schematic view of a preferred pitch adjustment device according to the invention;

Figure 2

schematic view of a preferred embodiment of a movable tooth according to the invention;

Figures 3 & 4

illustrations of the interaction of a preferred embodiment of a movable tooth according to the invention and an exemplary rolled product;

Figure 5

geometric representations of teeth of a stationary rake according to the invention.

[0009] Figure 1 shows a preferred embodiment of a pitch adjustment device equipping a cooling bed 100 configured for cooling rolled product 200. The cooling bed 100 comprises a plurality of mutually spaced stationary rakes 101 with cyclically movable carryover rakes interspaced there between, each rake comprising evenly spaced teeth 103 characterized by a nominal pitch L and configured for supporting the rolled product 200. The pitch adjustment device according to the invention comprises a movable tooth 1 and means for moving said movable tooth. Preferentially, the latter are able to rotate and/or translate said movable tooth 1. In particular, said means for moving the movable tooth 1 comprise an adjustable tie rod 2, a lever 3 to which said movable tooth 1 is connected by means of said adjustable tie rod 2, which length is preferentially adjustable in function of geometric dimensions of the cooling bed, and an actuator 4 for moving said lever 3, wherein said lever 3 is preferentially pivotally connected to the actuator 4.

[0010] Preferentially, the pitch adjustment device according to the invention comprises a controller 5 for controlling said means for moving the movable tooth 1 and therefore the displacement of the movable tooth 1. In particular, the controller 5 is configured for determining said pushing distance Lp (see Fig. 5), which might be fixed or variable during the working of the cooling bed. Preferentially, said controller 5 is able to automatically control the means for moving during the working process of the cooling bed, and notably in function of rolled product geometric parameters used for the determination of said pushing distance Lp. Preferentially, the controller 5 is able to control the actuation of said actuator 4 and consequently the position of the lever 3 and the movable tooth 1. In particular, the controller 5 is able to automatically control the actuation of said actuator 4 during the working process of the cooling bed in function of rolled product geometric parameters, like a section width of a rolled product. In particular, the controller is able to determine in real time said pushing distance (L_p).

[0011] In particular the movable tooth 1 is able to rotate around a rotation axis R when moved by said means for moving, for instance, when moved by means of the tie rod 2. The rotation axis R might be comprised or not in the body of the movable tooth 1. As illustrated in Figure 2, the pitch adjustment device according to the invention comprises preferentially a supporting structure 6 designed for supporting the movable tooth 1. Said supporting structure 6 comprises a rigid axle to which the movable tooth 1 is pivotally connected. The rotation axis R and said rigid axle are notably identical. Preferentially the tie rod 2 is pivotally connected to the movable tooth 1 in order to rotate the movable tooth 1 around said rotation axis R.

[0012] Preferentially the movable tooth 1 comprises at least one projection 11 (i.e. a part jutting out, e.g. a protrusion - see Fig. 2) which might be brought by rotation of the movable tooth 1 around said rotation axis R from a stand-by position N under the stationary rake to an active position A at the level of the stationary rake as exemplify in Figures 3 and 4. Said projection 11 may comprise an interchangeable insert designed for contacting the rolled product. Said insert might be replaced by another insert having a different shape in order to modify the shape of said projection 11 and adapt it to the rolled product geometry. The rotating movement of the movable tooth 1 from the stand-by position N below the stationary rake to the active position A is configured for bringing said projection 11 to the level of the stationary rake. Preferentially the rotation of the movable tooth 1 from the stand-by position N to the active position A is then configured for displacing said projection 11 at the level of the stationary rake according to a movement whose direction M is opposed to the transfer direction T of a rolled product from the cooling bed entry side to the cooling bed discharge side.

[0013] Preferentially, the movable tooth 1 is rotatable around said rotation axis R at least between the stand-by position N and a final active position AN. In the stand-by position N, the movable tooth 1 is positioned below the stationary rake of the cooling bed, and therefore cannot interact with a rolled product lying on said cooling bed. By moving from the stand-by position N to the final active position AN, the movable tooth 1 passes preferentially by a first active position A₁. The latter characterizes a position of the movable tooth 1 for which the projection 11 has for the first time at least one of its parts at the level of the stationary rake and may thus interact with a rolled product lying on the stationary rake. Then, in any active position A comprised between the first active position A₁ and the final active position AN, the displacement of the movable tooth 1 is done according to said movement whose direction M is opposed to the transfer direction T of a rolled product. Advantageously, by rotation of the movable tooth 1, the projection 11 is therefore able to actively laterally push a rolled product lying on the stationary rake according to a direction opposed to the direction of transfer T of said rolled product on the cooling bed and according to a pushing distance calculated and controlled by the controller 5.

[0014] Preferentially, the controller 5 is able to control the rotation of the movable tooth 1 and to determine an adjusted pitch L_a. In order to better understand the pitch adjustment technique according to the present invention, Figure 5 presents a schematic illustration of the adjusted pitch L_a, the nominal pitch L and the pushing distance Lp. Each tooth 103 of the stationary rake 101 is a projection comprising a single top S, a first side starting from said top and extending in direction of the entry side of the cooling bed, and a second side connected to the first side at said top S and extending in direction of the cooling bed discharge side. The distance separating two successive tops S_i and S_i+1 is the nominal pitch L. Then, let's define as connection point C, the point among the set of points binding two successive tops S_i and S_i+1 together that is the farthest from the straight line binding said two successive tops S_i and S_i+1. Then, for each tooth 103, the extremity of the first side is connected to the extremity of the second side of the first directly upstream tooth at the first upstream connection point C, and the extremity of the second side is connected to the first side of the first directly downstream tooth at the first downstream connection point C, the wording upstream and downstream being defined in relation to the flow of rolled products on the cooling bed during processing which follows the transfer direction T. Preferentially, a tooth 103 has a triangle shape. The space between two successive top defines a slot that is configured for supporting a rolled product 200. Depending on the width of a rolled product section, an elongated rolled product is either supported by a single slot, or several slots on each rake (see Fig. 3 & 4 illustrating a V-shape rolled product whose section width is similar to the nominal pitch size).

[0015] In particular, the controller 5 is able to determine the pushing distance L_p, i.e. the distance over which a rolled product might be laterally pushed by the movable tooth projection 11 in the direction M opposed to the transfer direction T so that at the end of pushing the remaining pitch length equals in particular to said adjusted pitch L_a, wherein L - L_a = f(L_p), with f(Lp) being the projection, on the straight line bounding two successive tops S_i and S_i+1 and according to a direction defined by the straight line bounding the connection point C between said successive tops S_i and S_i+1 with the downstream tooth top S_i+1, of a line segment starting at said connection point C and ending at an ending point E positioned on the straight line between said connection point C and the upstream tooth top S_i, the length of said line segment being the pushing distance Lp according to the invention.

[0016] Said pushing distance L_p might be in particular automatically calculated by the controller 5, before or during the working process of the cooling bed, in function of at least one of the following parameters: the nominal pitch L, geometric parameters of the rolled product like its section width or position of its gravity centre, geometric parameters of the stationary rake, a rolled product flow on said cooling bed. In other words, the controller 5 is in particular able to automatically calculate the adjusted pitch L_a in function of the above-mentioned parameters and then to actuate the actuator 4 so that the rotation of the movable tooth 1 causes a lateral displacement of the projection 1 at the level of the stationary rake that equals the pushing distance L_p. Said displacement of the projection 1 over the pushing distance Lp may take place before or during the working process of the cooling bed, with or without a rolled product lying over the slot between the successive tooth tops S_i and S_i+1 whose pitch is controlled by the pitch adjustment device according to the invention.

[0017] Consequently, the pitch adjustment device according to the present invention is in particular able to continuously adjust the pitch of a stationary rake by rotating the movable tooth 1 between the first active position A₁ and the final active position A_N. For instance, when the movable tooth 1 is at its first active position A₁, the adjusted pitch L_a is equal to the nominal pitch L, and when the movable tooth 1 is at its final active position AN, the adjusted pitch L_a is equal to 0. Advantageously, a rolled product lying on the cooling bed in an initial slot between two teeth of the stationary rake which pitch is controlled by the pitch adjustment device according to the invention might be pushed by rotation of the projection 11 around the rotation axis R into another slot positioned directly upstream said initial slot.

[0018] Preferentially, the movable tooth 1 has the following characteristics: it is pivotally mounted on said rotation axis R which is mounted in a fixed position, for instance on the supporting structure 6, compared to the stationary rake; it is driven into rotation by said adjustable tie rod 2 which is also pivotally connected to the movable tooth 1; it has a shape comprising said projection 11 which is geometrically designed for enabling a progressive decreasing of the pitch L according to a movement of the projection 11 going from downstream to upstream at the level of the stationary rake. Of course, said movement of the projection 11 and the rotation of the movable tooth 1 might be in particular reversed. Indeed, the controller 5 is in particular able to control the time period during which the movable tooth 1 has to stay at an active position, and consequently at what time the position of the movable tooth 1 has to be changed either for another active position or for the stand-by position. The controller is thus preferentially able to control the displacement of the movable tooth 1 in real time in order to adapt the movable tooth position to incoming rolled products.

[0019] Preferentially, several pitch adjustment devices according to the invention might be distributed between the stationary and/or movable carryover rakes along a direction perpendicular to the transfer direction T, in particular for a length equal to the maximum multiple of rolled product commercial length processable by the cooling bed. Advantageously, the length of the tie rod 2 might be adjusted to align to a same position all movable teeth equipping a same cooling bed in order to recover differences due to installation, manufacturing, thermal loads or wearing components. Each pitch adjustment device according to the invention is in particular positioned relatively to the stationary rakes so that when adjusting the pitch L separating two successive tooth tops S_i and S_i+1 by moving said movable tooth 1 from the stand-by position N to an active position A the projection 11 is able to move from a position under the tooth top S_i+1 (i.e. the projection 11 is vertically aligned with the tooth top S_i+1 and positioned below said tooth top) to an active position A above the second side of the tooth top S_i (i.e. the top of the projection 11 is positioned above the second side of the tooth top S_i). In particular, the movable tooth 1 has a geometrical shape configured for having at least said one part of the projection 11 above the second side of the tooth top S_i at the first active position A₁, while keeping remaining parts of said projection 11 under said tooth top S_i+1. A further displacement of the movable tooth 1 the direction opposed to the transfer direction of the rolled products is in particular configured for displacing at least the top of the projection 11 or the whole projection 11 above said second side of the tooth top S_i, making thus possible to push a rolled product laying on the slot between the tooth tops S_i and S_i+1 in direction of the cooling bed entry side.

[0020] In conclusion, the pitch adjustment device and method according to the present invention has the advantages that it is able to control the position of rolled product lying over the stationary rake of a cooling bed by laterally displacing a rolled product which position is not adequate. It is for example able to make a rolled product fall into the slot between two consecutive tooth tops, which makes it possible to control the distance separating rolled product on the cooling bed, and keep it constant. The pitch adjustment device might be used in-line (i.e. during processing of rolled products by the cooling bed) and/or offline (i.e. before the processing of rolled products by the cooling bed). In particular, in the in-line working mode, the pitch adjustment device tooth is moved during the cooling bed cycle or working: each time a rolled product is deposed on the cooling bed, the tooth pushes said rolled product in the direction M; in the offline working mode, the tooth does not move during the cooling bed cycle or working and is maintained at a single fixed active position A, for example A_n. In this case, the rolled product, for instance an elongated bar, preferentially falls onto the tooth during its transfer to the discharge side of the cooling bed, and slides backwards in the direction M. Consequently, the pitch adjustment device according to the invention advantageously avoids any pre-setting of the cooling bed before each product campaign, it improves the stability of the rolled product during its transfer to the discharge side without increasing the dimension and/or weight of the cooling bed.

Claims

1. Pitch adjustment device designed for equipping a cooling bed (100) configured for cooling rolled products (200), said cooling bed (100) comprising a plurality of mutually spaced stationary rakes (101) with cyclically movable carryover rakes interspaced there between, each rake comprising evenly spaced teeth (103) characterized by a nominal pitch (L) and configured for supporting said rolled products (200), said pitch adjustment device comprising:

a movable tooth (1);

means for moving said movable tooth (1);
and being characterized in that the movable tooth (1) is able to push laterally a rolled product (200) lying on the cooling bed (100).

2. Pitch adjustment device according to claim 1, wherein the movable tooth (1) is able to push laterally over a predetermined pushing distance (Lp).

3. Pitch adjustment device according to claim 1 or 2, wherein said means for moving the movable tooth (1) comprise an adjustable tie rod (2), a lever (3) to which said movable tooth (1) is connected by means of said adjustable tie rod (2), and an actuator (4) for moving said lever (3).

4. Pitch adjustment device according to one of the claims 1 to 3, characterized in that it comprises a controller (5) for controlling said means for moving the movable tooth (1).

5. Pitch adjustment device according to claim 4, wherein the controller (5) is able to determine said pushing distance (L_p).

6. Pitch adjustment device according to one of the claims 1 to 5, wherein the movable tooth (1) is able to rotate around a rotation axis (R) when moved by said means for moving.

7. Pitch adjustment device according to one of the claims 1 to 6, wherein the movable tooth (1) comprises at least one projection (11).

8. Pitch adjustment device according to claim 7, wherein the movable tooth (1) is configured for displacing by rotation said projection (11) at the level of the stationary rake according to a movement whose direction (M) is opposed to a transfer direction (T) of a rolled product from the cooling bed entry side to the cooling bed discharge side.

9. Cooling bed comprising a pitch adjustment device according to one of the previous claims.

10. Pitch adjustment method for adjusting the pitch of a cooling bed (100) comprising a plurality of mutually spaced stationary rakes (101) with cyclically movable carryover rakes interspaced there between, each rake comprising evenly spaced teeth (103) characterized by a nominal pitch (L) and configured for supporting a rolled product (200), said pitch adjustment method comprising the following steps:

determining an adjusted pitch (L_a);

adjusting a position of a movable tooth (1) in function of said adjusted pitch (L_a);
characterized in that the adjustment of the position of said movable tooth (1) is done according to a movement configured for pushing laterally a rolled product (200) lying on the stationary rake (101).

11. Pitch adjustment method according to claim 9, wherein said adjusted pitch (L_a) is automatically determined.

12. Pitch adjustment method according to one of the claims 9 or 10, wherein the rolled product (200) is laterally pushed over a predetermined pushing distance (Lp).

Drawing