Patent Application
20180297096
The present invention relates to a coiling system for coiling a hot rolled product according to the preamble of claim 1, and to a method for forming a hot rolled product according to the preamble of the independent method claim. A hot rolled product here refers to a bar, wire, rod, strip or the like formed by hot rolling and made from a metal material, including but not limited to copper, brass, aluminium, and steel, such as spring steel, bearing steel, stainless steel, etc.
A common type of coiling system for forming a hot rolled product into a coil, comprises a base assembly supported by a support structure. The support structure comprises a drive mechanism configured to rotate the base assembly around a vertical axis of rotation. The base assembly comprises a base plate for supporting the coil, a central drum extending from the base plate along the vertical axis, and an outer housing, attached to the base plate outside of said central drum, such that an annular space is formed between the central drum and the outer housing. The coiling system further comprises a feeding device configured to feed hot rolled product to the base assembly so as to form a coil. When in use, hot rolled product is fed from the feeding device into the space provided between the central drum and the outer housing, so that a first end of the hot rolled product lands on the base plate. As the base assembly is rotated, hot rolled product forms a coil around the central drum. The outer housing ensures that each newly formed loop of the coil is formed on top of an already formed loop.
However, a problem with this coiling system is that the gap between the feeding device and an already coiled portion of the hot rolled product, on top of which the hot rolled product fed from the feeding device lands, varies throughout the coil forming cycle. This results in a coil with low and non-uniform density and poor stability. Coiling systems have therefore been developed in which a spiral shaped feeding tube is used, through which the hot rolled product is fed into the annular space between the central drum and the outer housing. Such spiral shaped feeding tubes can be inserted into the annular space and can thereby reduce the distance that the hot rolled product drops onto the already coiled portion. The density of the formed coil can thereby be improved, but such feeding tubes are on the other hand expensive and difficult to maintain. They are also associated with safety problems during operation, and the density obtainable with such feeding tubes is for many applications not sufficient.
WO2009123685 discloses a coiling system in which an outer housing is movable in the vertical direction, together with the feeding device. In this way, the distance that the hot rolled product drops can be significantly reduced. However, this coiling system, as well as other known coiling systems, become very tall and space consuming. When the finished coil is to be removed from the coiling system, the coil is lifted from the base assembly, or the base assembly is lowered so that the coil may be removed. A basement or an additional floor is therefore typically required to be able to remove the coil. This is inconvenient, as the available space is often limited and may be needed for other purposes.
Another problem with known coiling systems is that the cycle time is relatively long, due to the amount of time needed to remove the coil from the coiling system after finishing one coil, and prepare it for formation of a second coil. Two separate coiling systems, which can alternately receive and coil hot rolled product from a rolling mill, are therefore often used. Yet another problem is the large energy consumption of the coiling systems, resulting from the large moment of inertia of the systems.
It is an object of the present invention to overcome at least some of the above mentioned problems. In particular, it is an object to provide solutions by means of which less vertical space is needed in a coil forming process and by means of which cycle times and energy consumption can be reduced. Another object is to provide a coiling system which is versatile and easily adaptable to different coil sizes and product diameters. Yet another object is to provide a coiling system and a method for forming a hot rolled product by means of which a relatively high density and uniformity of the finished coil can be achieved.
At least the primary object is achieved by means of a coiling system as initially defined, which is characterised in that the base assembly is releasably connected to the first drive mechanism so that the base assembly, after coiling, may be removed from the support structure. In this way, the coil does not need to be lifted off from the base plate when the base plate is mounted on the support structure. Instead, the entire base assembly, comprising the finished coil, can be disconnected from the support structure before removing the coil from the base structure and transferring it to e.g. a conveyor or a pallet. This reduces the vertical space needed to accommodate the coiling system. It also increases the versatility of the coil manufacturing process, since the removal of the coil from the base assembly can be carried out either in immediate connection to the coiling system, or at another location after transport using e.g. a conveyor. Removal of the coil can be achieved e.g. by tilting the base assembly and transferring the coil to a suitable coil holder, or by lifting off the coil. In either way, the vertical space needed to remove the coil from the coiling system is reduced.
Since the base assembly is removable, the coiling system is also easy to adapt to e.g. different diameters of the hot rolled product, or different desired coil diameters. By simply switching base assemblies, the same support structure can be used for different applications. The removable base assembly also reduces the cycle time of the coiling system, since the base assembly after coiling can be quickly removed from the support structure, and replaced by another empty base assembly. In this way, it is not necessary to have two separate coiling systems to alternate between. Instead, it is sufficient to have one support structure and at least two base assemblies.
According to one embodiment of the invention, the coiling system further comprises an annular collecting member arranged around the central drum above the receiving sleeve and movable in the axial direction together with the feeding device so as to guide the hot rolled product onto a previously coiled portion of said product. In this embodiment, the receiving sleeve has a height which is substantially smaller than a height of the central drum, since it only needs to cover a first few loops of the coil as it is being formed. The annular collecting member collects and guides the hot rolled product onto those loops as the coiling cycle proceeds. The annular collecting member is arranged above the receiving sleeve. The annular collecting member thus forms a movable outer drum, reducing the distance between the feeding device and the previously coiled portion on which the hot rolled product is to land. Thus, the density of the coil as well as the uniformity can be improved. The movable annular collecting member also enables formation of uniform coils of different height, since there is no fixed outer housing. Another advantage of this embodiment is that the moment of inertia of the base assembly can be reduced, since the annular collecting member removes the need for an outer housing, e.g. a receiving sleeve having a similar vertical extension as the central drum, connected to and rotating together with the base assembly. The total energy consumption of the coiling system can thereby be reduced.
According to one embodiment of the invention, the annular collecting member has a shorter extension along the vertical axis than the central drum, so that the annular collecting member surrounds only a minor portion of the central drum. The total height of the coiling system can thereby be reduced in comparison with coiling systems comprising a tall movable outer drum or the like, completely encapsulating the formed coil. Furthermore, the weight of the coiling system is reduced, further reducing the energy consumption.
According to one embodiment of the invention, the annular collecting member is connected to the feeding device. This is a convenient way of achieving simultaneous vertical movement of the feeding member and the annular collecting member.
According to one embodiment of the invention, the annular collecting member is in the form of a rotatable collecting ring. Such a collecting ring provides a stable support for the hot rolled product as it is being coiled. The rotatable collecting ring may e.g. be rotated by means of the first drive mechanism, used to rotate the base assembly, or by a separate drive mechanism. Rotating the collecting ring prevents scratches on the hot rolled product.
According to one embodiment of the invention, the coiling system further comprises a support on which the collecting ring is rotatably mounted. The support provides a convenient means for supporting also a drive mechanism and for connecting the annular collecting member to the feeding device.
According to one embodiment of the invention, the coiling system further comprises a second drive mechanism configured to rotate the collecting ring around the vertical axis. Separate drive mechanisms simplifies the construction of the coiling system.
According to one embodiment of the invention, the first and the second drive mechanisms are configured to be operable independently of each other. In this way, the rotational speed of the collecting ring can be adjusted independently of the rotational speed of the base assembly and the coiling conditions can thereby be optimised.
According to one embodiment of the invention, the coiling system further comprises a pre-bending device configured to bend the hot rolled product as it is being fed from the feeding device. This makes the hot rolled product easier to form into a coil.
According to one embodiment of the invention, the central drum comprises wall segments that are movable between an outer position and an inner position. When the coil is to be removed from the base assembly, the wall segments can be collapsed, which reduces the risk of damaging the coil during removal.
According to one embodiment of the invention, the coiling system further comprises a transfer arrangement configured to move the base assembly away from the support structure in a horizontal or essentially horizontal plane. Such a transfer arrangement enables fast removal of the base assembly from the support structure after coiling, enabling short cycle times. The vertical space needed for the coiling system can be minimised since the movement of the base assembly is essentially in the horizontal plane, although a small vertical movement may be necessary to release the base assembly from the support structure. Such a vertical movement can be in the order of a few decimetres, such as 3-4 dm. Furthermore, the coiling system is energy efficient since vertical lifting of the base assembly holding the finished coil, which is often heavy, is to a large extent avoided.
According to another aspect of the present invention, at least the primary object is achieved by a method for forming a hot rolled product into an annular coil as initially defined, characterised in that the step of removing the coil from the coiling system comprises removing the base assembly from the support structure prior to removing the coil from the base assembly. In this way, the coil can be removed from the coiling system without the need to lift the coil along the vertical axis. The method is thereby less space consuming and more energy efficient than known methods in which the coil is removed by lifting it off the coiling system as the base assembly is mounted on the support structure.
The proposed coiling system is advantageously used in the method according to the invention. Advantages and advantageous features of the method according to the invention correspond to those discussed in connection with the proposed coiling system.
According to one embodiment of this aspect of the invention, the step of removing the coil from the coiling system comprises tilting the base assembly prior to removing the coil. Vertical space can thereby be saved, since the coil can be removed from the base assembly by movement in a horizontal plane.
According to another embodiment of this aspect of the invention, the coiling system is located in a coiling station, and the base assembly holding the coil is transported away from the coiling station using a conveyor prior to removing the coil from the base assembly. This is suitable for smaller rolling mills, and enables a time efficient handling of coils since the coil does not need to be transferred to an intermediate coil pallet or the like used for transporting the coil to a coil compacting station. Instead, the base assembly is transported to the compacting station, where the coil is removed from the base assembly and thereafter compacted.
According to another embodiment of this aspect of the invention, an annular collecting member arranged around the central drum is provided, and the method comprises guiding the hot rolled product onto a previously coiled portion of said product by moving the feeding device together with the annular collecting member upwardly along the vertical axis.
Other advantageous features as well as advantages of the present invention will appear from the following description.
The invention will in the following be further described by means of example with reference to the appended drawings, wherein
A coiling station comprising a coiling system 1 according to an embodiment of the invention is shown in
The base assembly 3 comprises a base plate 6, a central drum 7 extending from the base plate 6 along the vertical axis, and a receiving sleeve 8 arranged outside of the central drum 7, such that an annular space is provided near the base plate 6, between the central drum 7 and the receiving sleeve 8. The central drum 7 has collapsible wall segments 7a, 7b, 7c that are movable between an outer position and an inner position. The receiving sleeve 8 has a height corresponding to a few loops of coiled hot rolled product, substantially smaller than a total height of the central drum 7.
The feeding device 4 is configured to feed hot rolled product from e.g. a rolling mill downwardly to a pre-bending device 9 provided at a front end of the feeding device 4. The pre-bending device 9 is configured to bend the hot rolled-product before it is being coiled. The feeding device 4, and in particular its front end, is movable up and down along the vertical axis, so that hot rolled product can be fed to the base assembly 3 at a suitable height.
On the front end of the feeding device 4, a rotatable collecting ring 10 arranged around the central drum 7 is provided, rotatably mounted on a support 11. The collecting ring 10 has an inner diameter equivalent to an inner diameter of the receiving sleeve 8. The collecting ring 10 is movable together with the feeding device 4 up and down along the vertical axis. In the vertical direction, it surrounds only a minor portion of the central drum 7, since it has a small height in comparison with the central drum 7. A second drive mechanism 12, configured to rotate the collecting ring 10 around the vertical axis, is also provided on the support 11. The second drive mechanism 12 is here operable independently of the first drive mechanism. It may thus rotate the collecting ring 10 at the same rotational speed as the base assembly 3 or at a different rotational speed.
The coiling system 1 further comprises a transfer arrangement 13 configured to move the base assembly 3 away from the support structure 2 in a horizontal plane when the base assembly 3 has been released from the support structure 2. The transfer arrangement 13 here comprises two rotatable arms 14 extending from a hub 15 positioned between the support structure 2 and a rest 16, to which the base assembly can be transferred from the support structure 2. The transfer arrangement 13 is also used to transfer an empty base assembly 3, not holding a coil 17, to the support structure 2 from the rest 16. The skilled person of course realises that there are many different ways to design a transfer arrangement which may be used to move the base assembly away from the support structure.
When a coil is to be formed using the shown coiling system 1, the base assembly 3 is mounted onto the support structure 2 with the wall segments 7a, 7b, 7c in the outer position. The base assembly 3 is rotated by means of the first drive mechanism at a rotational speed ω_1. Via the feeding device 4, the pre-bending device 9, and the collecting ring 10, a first end of a hot rolled product is fed to the rotating base assembly 3. As the coil forming process begins, the feeding device 4, the pre-bending device 9 and the collecting ring 10 are in a lowermost position close to the receiving sleeve 8, as shown in
The base assembly 3 holding the finished coil 17 is thereafter released from the support structure 2 and transferred to the rest 16 using one of the rotatable arms. At the same time, an empty base assembly 3 is transferred from the rest 16 to the support structure 2 for formation of another coil. The base assembly 3 holding the finished coil 17 is thereafter tilted, the wall segments 7a, 7b, 7c are moved to the inner position, and the coil 17 is removed from the base assembly 3 and transferred to a coil pallet 18 via an intermediate support 19. The coil pallet 18 holding the coil 17 can thereafter be transported away from the coiling station, e.g. using a conveyor. The coil is usually transferred from the coiling station to a compacting station, where it is compacted prior to further transportation. An alternative to using a coil pallet 18 is to transport the entire base assembly 3 holding the coil 17 away from the coiling station using a conveyor. The base assembly 3 in this case functions as a coil pallet.
A method for forming a hot rolled product into an annular coil 17 according to an embodiment of the invention is illustrated in
The invention is of course not in any way restricted to the embodiments described above, but many possibilities to modifications thereof would be apparent to a person with skill in the art without departing from the scope of the invention as defined in the appended claims. For example, the annular collecting member may comprise at least two vertically spaced apart rings, between which a number of rotatable rolls are provided. The rolls in this case serve to collect the hot rolled product without the use of a second drive mechanism.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1551334-4 | Oct 2015 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/SE2016/050977 | 10/11/2016 | WO | 00 |
