Patent Grant
12115578
This application is a U.S. national stage application, filed under 35 U.S.C. § 371, of International Application No. PCT/EP2019/085618, which was filed on Dec. 17, 2019, and which claims priority from European Patent Application No. EP 18213318.1, which was filed on Dec. 18, 2018, the contents of each of which are incorporated by reference into this specification.
The present invention relates to a robotized system for changing a sliding gate valve plate in a sliding gate valve in a metallurgic casting installation. The present invention proposes a robotized system which can be fully automated, capable of removing a spent sliding gate valve plate from its casting position in a plate support frame coupled to a metallurgic vessel, storing it for refurbishing or for disposal, and taking a new sliding gate valve plate and loading it into its casting position in the plate support frame.
Sliding gate valves have been known since 1883. Sliding gate valves are used to control the flow of molten metal poured from an upstream metallurgic vessel to a downstream vessel. For example, from a furnace to a ladle, from a ladle to a tundish or from a tundish into an ingot mould. For example, US-A-0311902 or US-A-0506328 disclose sliding gate valves arranged at the bottom of a casting ladle wherein pairs of refractory sliding gate valve plates provided with a through bore are slid one with respect to the other. When the pouring orifices are in register or partially overlap, molten metal can flow through the sliding gate valve while when there is no overlap between the pouring orifices, the molten metal flow is totally stopped. Partial overlap of the pouring orifices allows the regulation of the molten metal flow by throttling the molten metal stream. Although sliding gate valves have evolved considerably in the last decades, the principle remains the same, with one plate sliding relative to another to control the level of overlap between the through bores of the two plates.
Sliding gate valve plates are operated under severe conditions when mounted in a sliding gate valve and wear off with time, so that they must be replaced at regular intervals. Tube changing systems for changing a pouring nozzle from a sliding gate valve of a tundish have been proposed in the art, such as e.g., in EP2547474. In many cases, however, the metallurgic vessel is emptied of its content, moved away from the casting installation and checked for signs of excessive wear and refurbished, including changing the sliding gate valve plates. To date, this operation is made mostly manually by human operators. This is hard labour: handling heavy weights under time pressure, at high temperatures and requiring strength to disrupt any adhesion between mortar and a sliding gate valve plate to be changed. Human errors can be made under such stressful conditions. There is a demand from the industry to develop automated systems for changing sliding gate valve plates using robots instead of human operators.
Configuring a robot for changing a sliding gate valve plate, however, faces many challenges. The sliding gate valve plates are quite heavy to handle, and they must be positioned with much accuracy into corresponding receiving cradles provided in the plate support frame. The position of the metallurgic vessel changes from one operation to the other and the robot must adapt to the different positions of each new metallurgic vessel brought for refurbishing. Spent sliding gate valve plates are hot, whilst new sliding gate valve plates are cold, thus changing the dimensions of the plates. Often fumes and vapours obscure visibility. A top sliding gate valve plate is coupled to an inner nozzle with mortar, which must be broken before removing the top sliding gate valve plate. To the applicant's best knowledge, no satisfactory robotized system for changing sliding gate valve plates has been successfully implemented in a metallurgic installation.
US20100017027 describes an arrangement for the maintenance of a sliding gate valve mounted on the spout of a container for molten metal. The arrangement comprises at least one tool magazine, means for opening and closing the sliding gate valve, and a robot comprising an automatic grip changing system, the robot being able to automatically detect the exact position of the container or of the sliding gate valve. This document, however, does not give any details on the automatic grip changing system.
JP H07 60434 discloses an apparatus for replacing the nozzle and plates of metallurgical vessel. In the system described, the plates are handled by their through bores, which can consequently be damaged during the operation.
DE 10 2009 050216 discloses a method and apparatus for exchanging the slide closure of a metallurgical vessel, wherein the sliding closure is gripped by an industrial robot. This document, however, does not give any details on the gripping system.
U.S. Pat. No. 5,645,793 discloses a system for exchanging a whole slide gate valve of a metallurgical vessel but does not disclose a system for replacing individual slide gate valve plates.
JP H08 19853 also discloses a system for exchanging a whole slide gate valve of a metallurgical vessel. Once again, a system for replacing individual slide gate valve plates is not disclosed.
JP H04 66268 also discloses a system for exchanging a whole slide gate valve of a metallurgical vessel. Once again, a system for replacing individual slide gate valve plates is not disclosed.
The aim of the present invention is to meet the foregoing challenges by providing a novel robotized system for changing sliding gate valve plates, combining the efficacy and reproducibility of a robot with the flexibility required to adapt to changing conditions (temperature, dimensions, relative positions, fumes, etc.). This and other advantages of the present invention are explained more in detail in the following sections.
The objectives of the present invention have been reached with a robotized system for fixing or removing a sliding gate valve plate to or from a sliding gate valve, comprising:
The sliding gate valve plate can be a top or a bottom sliding gate valve plate, wherein the second surface has an area smaller than the sliding surface. In a projection onto the sliding surface, the second surface is enclosed within the sliding surface, and the peripheral edge and/or the second surface comprises bevelled portions forming the gripping holds.
Alternatively, the gripping holds can be protrusions protruding out of the peripheral edge and are preferably part of a metal can cladding a portion of the peripheral edge. The gripping holds can also be recesses opening at the peripheral edge and penetrating in the thickness of the slide gate plate. The recesses are preferably at least partly formed in a metal can cladding a portion of the peripheral edge. A sliding gate valve plate can comprise a combination of gripping holds formed by bevelled portions, protrusions and/or recesses.
Alternatively, the gripping holds can be portions of the second surface adjacent to the peripheral edge, and the clearings or apertures are then sufficiently deep to allow the gripping clamps to reach a position facing said portions of the second surface when the sliding gate valve plate is locked in the receiving plate support frame, so that the gripping clamps can move to the gripping position, engaging the second surface.
In an advantageous embodiment, the handling interface of the robot comprises N=3 or 4 gripping clamps, which are L-shaped with a free end and a coupled end movably mounted so as to move the free end from the open position to the gripping position suitable for coupling the free end of the L-shaped gripping clamps to the gripping holds of the sliding gate valve plate. The L-shaped gripping clamps can be rotatably mounted so as to rotate between the open and gripping positions about a rotation axis,
For example, the handling interface of the robot comprises one or two adjacent rocking clamps and comprises one or two adjacent gyrating clamps. In an advantageous embodiment, the handling interface or the top plate support frame comprises a protrusion such that when the robot faces the top plate support frame to remove the top sliding gate valve plate therefrom, with the one or two gyrating clamps in gripping position, the robot is at an angle with respect to the sliding surface such that the one or two rocking clamps can rotate and contact the gripping holds, but cannot reach the gripping position without pulling one end of the top sliding gate valve plate which rotates about an axis passing by the one or two gyrating clamps and easily breaking mortar adhering it to the metallurgic vessel.
The handling interface of the robot preferably further comprises resilient elements suitable for pressing against the sliding surface when the free ends of the L-shaped gripping clamps are in the gripping position and thus locking the sliding gate valve plate to the handling interface of the robot.
In an advantageous embodiment, the handling interface of the robot comprises guiding pins protruding beyond a plane comprising the sliding surface when a sliding gate valve plate is gripped. The plate support frame comprises funnel shaped cavities for receiving the guiding pins and guiding the sliding gate valve plate in alignment with the receiving cradle.
The handling interface is preferably coupled to an arm of the robot by means of a coupling element comprising pneumatic or hydraulic system capable of controlling the compliance of the coupling element and thus the compliance of the coupling of the handling interface to the robot.
The present invention also concerns a method for fixing a sliding gate valve plate to a plate support structure of a slide gate valve mounted at a bottom of a metallurgic vessel, comprising,
The present invention also concerns a method for removing a top sliding gate valve plate from a plate support structure of a slide gate valve mounted at a bottom of a metallurgic vessel, comprising,
In these figures,
As shown in
Sliding Gate Valve and Sliding Gate Valve Plates
The sliding gate valve can be a two-plate or a three-plate sliding gate valve. As illustrated in
A sliding gate valve plate (1) comprises a sliding surface (1s) separated from a second surface (1d) by a thickness of the sliding gate valve plate and joined to one another by a peripheral edge (1e). It also comprises a through bore (1b) extending normal to the sliding surface. The second surface (1d) of a mid-sliding gate valve plate is also a sliding surface. The top, bottom, and optionally the mid-sliding gate valve plates are each coupled to a receiving cradle (12) of a corresponding top, bottom, and optionally mid-plate support frame (11t, 11L, 11m), with at least one sliding surface (1s) of one plate in sliding contact with a sliding surface (1s) of a second plate. The top plate support frame is fixed relative to the metallurgic vessel, because the top sliding gate valve plate (1t) is generally coupled to an inner nozzle (42) of the metallurgic vessel (41) with mortar (43) as illustrated in
The geometries of the receiving cradles (12) of the plate support frames must mate the geometries of the corresponding sliding gate valve plates, such that one does not move relative to the plate support frame during the sliding of one sliding surface relative to the other driven by the translation of the movable carriage. For access to the sliding gate valve plates, the plate support frame can generally be opened like a book by rotation about hinges of the bottom plate support frame (11L) relative to the top (and/or mid-) plate support frame as illustrated schematically in
Traditionally, for removing a spent sliding gate valve plate (1) from its receiving cradle (12), in particular a top sliding gate valve plate (1t) which is generally fixed with mortar (43) to an inner nozzle (42), an operator would run an elongated tool through the through bore of the sliding gate valve plate and pull and push to remove the sliding gate valve plate from the receiving cradle (12). This operation definitely ruins the through bore of a sliding gate valve plate, which is not so important if it is to be disposed of but does not allow a refurbishing of the plate. Although the elongated tool is not handled as hardly when mounting a new sliding gate valve plate into a receiving cradle (12), there is a risk of damaging the through bore of a new sliding gate valve plate. It is clear that a robot can be configured for handling an elongated tool in a similar way as a human operator would use. To avoid possible damages to the through bore, however, the robotized system of the present invention uses gripping means for safely gripping and handling a sliding gate valve plate. The gripping means permit a sliding gate valve plate to be held by its peripheral edges (1e) and/or by its second surface (1d) and not at all by the through hole as is traditionally performed by human operators. To this effect, the gripping means require two components: (a) the robot comprises gripping clamps (25g, 25r, 25t) discussed in continuation; (b) the receiving cradle of the plate support frame comprises clearings (15) allowing access of the gripping clamps (25) to gripping holds (5) located at the peripheral edge (1e) and/or at the second surface (1d), adjacent to the peripheral edge, mating the gripping clamps (25g, 25r, 25t) of the robot, when the sliding gate valve plate is locked in the receiving plate support frame.
In an advantageous embodiment, the gripping means of the robotized system for fixing or removing a sliding gate valve plate to or from a sliding gate valve is configured such that
The robot used in the present invention can be any robot available on the market comprising sufficient degrees of freedom, such as for example, five to seven degrees of freedom, for performing the operations of collecting a sliding gate valve plate, moving it between a storage position and a sliding gate valve, and for positioning the sliding gate valve plate into a corresponding receiving cradle (12). One essential feature of the present invention is a handling interface (21) provided at the end of an arm of the robot and equipped with gripping clamps (25g, 25r, 25t) for gripping the sliding gate valve plate. The handling interface (21) is configured for,
The foregoing operations can be safely carried out by means of the gripping clamps (25g, 25r, 25t) which interact with the gripping holds (5) of the sliding gate valve plates. In an advantageous embodiment, the handling interface (21) of the robot comprises N=3 or 4 gripping clamps (25g, 25r, 25t), which are L-shaped in that they comprise a first rod or segment comprising a free end and a second rod or segment comprising a coupled end, said first rod being movably mounted so as to move the free end from an open position suitable for surrounding the peripheral edge (1e) of the sliding gate valve plate to a gripping position, thus forming a L-shape such as illustrated in
The L-shaped gripping clamps (25g, 25r, 25t) are movable, from an open position, wherein the L-shaped gripping clamps circumscribe the peripheral edge of a sliding gate valve plate to a gripping position wherein the free ends of the L-shaped gripping clamps interact with the gripping holds (5) of the sliding gate valve plate. In the open position, the L-shaped gripping clamps match the clearings (15) of the corresponding clearings, so that the handling interface (21) can be translated along a direction normal to the sliding surface (1s) of a sliding gate valve plate driving the free ends of the L-shaped gripping clamps through the clearings (15) beyond the sliding surface of the sliding gate valve plate, in registry with the gripping holds (5) of the sliding gate valve plate. The L-shaped gripping clamps can then be moved to their gripping position, so that the free ends interact with the gripping holds (5) and the sliding gate valve plate is thus safely gripped.
In an advantageous embodiment, the handling interface (21) of the robot further comprises resilient elements (27) suitable for pressing against the sliding surface (1s) when the free ends of the L-shaped gripping clamps are in the gripping position. The resilient elements press against the sliding surface (1s) of a sliding gate valve plate away from the handling interface (21), whilst the gripping clamps retain the sliding gate valve plate, thus safely locking the plate into position between the resilient means (27) and the gripping clamps (25g, 25r, 25t) of the handling interface (21). The resilient elements can comprise mechanical springs, such as helicoidal springs or blade springs, or can be made of resilient materials, such as rubbers. Because the temperature of a sliding gate valve plate can vary greatly depending on whether it is a new plate, or a spent plate brought directly after a casting operation, it is advantageous that the resilient means comprise mechanical springs. The portion of the resilient elements contacting the sliding surface (1s) of a sliding gate valve plate must be such as to avoid damaging the sliding surface by scratching. In an alternative embodiment, as illustrated in FIG. 9, the handling interface (21) of the robot further comprises rigid elements (28) for pressing against the sliding surface (1s) when the free ends of the L-shaped gripping clamps are in the gripping position.
The movable L-shaped gripping clamps (25g, 25r, 25t) are preferably rotatably mounted so as to rotate between the open and gripping positions about a rotation axis. Rocking clamps (25r) rotate about a rotation axis intersecting the coupled end, and normal to both rods of the L-shaped gripping clamps including the free end and the coupled end (cf.
Gyrating clamps (25g) rotate about a rotation axis parallel to, preferably coaxial with the rod of the L comprising the coupled end (cf.
In an alternative embodiment, as illustrated in
Before driving the new unit (1n) to the top plate support frame (11t), the second surface (1d) of the top slide gate valve plate (1t) is advantageously coated with mortar, such that it will adhere to the inner nozzle (42). Alternatively, the inner nozzle (42) can be coated with mortar before the new unit (1n) is driven to the plate support frame (11t), such that it will adhere to the top slide gate valve plate (1t).
When the rotating clamps are rotatably mounted, the handling interface (21) can comprise rocking clamps (25r) only (i.e., N rocking clamps), gyrating clamps only (25g) (i.e., N gyrating clamps), or both rocking and gyrating clamps (25r, 25g) (i.e., n rocking clamps and N−n gyrating clamps, with n<N). In an advantageous embodiment, illustrated in
A sliding gate valve plate (1) can be inscribed in a rectangle defining a length, L, and width, W, with W≤L of the sliding gate valve plate. It is advantageous that a pair of similar gripping clamps be located side by side adjacent to a first end of the length, L, and one or a pair of similar gripping clamps be located side by side adjacent to a second end, opposite the first end of the length, L, wherein the pair of gripping clamps adjacent to the first end can be same as or different from the one or pair of gripping clamps adjacent to the second end. For example, the handling interface (21) of the robot can comprise one or two adjacent rocking clamps (25r) at a first end of the length, L, and comprises one or two adjacent gyrating clamps (25g) at a second end of the length, L.
A combination of rocking and gyrating gripping means can be particularly advantageous for ripping a spent top sliding gate valve plate (1t) coupled to an inner nozzle (42) by means of a mortar (43) as illustrated in the embodiment of
This embodiment can thus be used in a method illustrated in
The gyrating clamps (25g) can be rotated prior to or simultaneously with the rocking clamps (25r). A simultaneous rotation of the gyrating and rocking clamps allows using a single drive for driving the rotation of the two types of clamps.
One major advantage of rotatable L-shaped gripping clamps as discussed supra is that they can adapt to sliding gate valve plates of slightly varying geometries, either because the plates have a different design, or because they are at different temperatures: room temperature for a new sliding gate valve plate (1n), and substantially higher temperatures for spent sliding gate valve plates, which are thermally expanded relative to the new ones at room temperature.
Robot (20)
Because each new metallurgic vessel (41) is not necessarily positioned at exactly the same position relative to the robot (20), It is not practical to configure the robot to repeat exactly the same movements with each new metallurgic vessel. It is therefore advantageous that the robot be provided with an electromagnetic wave recognition system, such as an optical camera system with recognition of elements, infrared (e.g., Lidar), radar, etc. These systems may not have the accuracy required for the operations to be performed by the robot and, in case of an optical recognition system, fumes and vapours may disrupt visibility and the accuracy of the movements.
In one embodiment, illustrated in
It is therefore advantageous as illustrated in
When small movements of the handling interface (21) relative to the arm of the robot it is attached to are required, the pressure in the pneumatic or hydraulic system (29p) is released, the coupling element becomes compliant allowing the handling interface (21) to rotate and translate relative to the robot arm. A compliant coupling element (29) is useful when the position of the handling interface (21) relative to the support frame must be finetuned beyond the accuracy of the robot's arm (note that the plates are quite heavy, which is detrimental to the accuracy of the robot's arm). For example, as shown in
The robot can be mounted on a rotating basis and, to increase the span if its reach, can be mounted on rails to move between a storing position and a slide gate valve position.
Gripping Holds (5) of the Sliding Gate Valve Plates
In one embodiment illustrated in
In an alternative embodiment, illustrated in
In an alternative embodiment, illustrated in
In yet an alternative embodiment illustrated in
Clearings or Apertures (15) of the Plate Support Frame (11)
As illustrated in
When the gripping holds (5) are portions of the second surface (1d) of the plate (1) adjacent to the peripheral edge (1e), such as represented in
The receiving cradle can also comprise a bottom floor and holding blocks protruding out of the bottom floor and positioned at strategic locations for holding a sliding gate valve plate in place upon actuating the sliding gate valve. With such configurations, clearings (15) are readily available and the plate support frame (11) needs not be amended to implement the robotized system of the present invention. Only the sliding gate valve plates need be provided with gripping holds (5). In the case of sliding gate valve plates comprising a bevelled peripheral edge as described in WO2017129563, even the plates need not be amended, and only the robot and the handling interface are required for implementing the present invention. This is a great advantage as only minimal adaptions are required.
Various features and characteristics of the invention are described in this specification and illustrated in the drawings to provide an overall understanding of the invention. It is understood that the various features and characteristics described in this specification and illustrated in the drawings can be combined in any operable manner regardless of whether such features and characteristics are expressly described or illustrated in combination in this specification. The Inventor and the Applicant expressly intend such combinations of features and characteristics to be included within the scope of this specification, and further intend the claiming of such combinations of features and characteristics to not add new matter to the application. As such, the claims can be amended to recite, in any combination, any features and characteristics expressly or inherently described in, or otherwise expressly or inherently supported by, this specification. Furthermore, the Applicant reserves the right to amend the claims to affirmatively disclaim features and characteristics that may be present in the prior art, even if those features and characteristics are not expressly described in this specification.
Therefore, any such amendments will not add new matter to the specification or claims, and will comply with the written description requirement under 35 U.S.C. § 112(a). The invention described in this specification can comprise, consist of, or consist essentially of the various features and characteristics described in this specification.
Advantages
The present invention is advantageous as it relieves human operators from hard labour conditions and is more reproducible with less to no risk of human error. Only minimal amendments are required in the installation to implement the invention. The clearing (15) in the receiving cradle (12) required for allowing the passage of the gripping clamps can be quite small, especially when using gyrating or rocking clamps (25g, 25r, 25t). The gripping clamps of the handling interface are quite insensitive to dimensional variations due to variations in temperature of a sliding gate valve plate. The sliding gate valve plates only need minimal redesigning, if at all, in case bevelled plates as described in WO2017129563 are used. The use of a coupling element (29) comprising pneumatic or hydraulic system (29p) gives the robot the compliance necessary for removing and loading into a receiving cradle relatively heavy sliding gate valve plates with high accuracy, thus reducing the risks of breaking any part.
| Number | Date | Country | Kind |
|---|---|---|---|
| 18213329 | Dec 2018 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/085618 | 12/17/2019 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/127241 | 6/25/2020 | WO | A |
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|---|---|---|---|
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| 506328 | Morris | Oct 1893 | A |
| 4685850 | Ohta et al. | Aug 1987 | A |
| 5645793 | Yamamoto | Jul 1997 | A |
| 5665264 | Sato | Sep 1997 | A |
| 8042601 | Bowman | Oct 2011 | B2 |
| 8215375 | Ebner | Jul 2012 | B2 |
| 8376196 | Ebner | Feb 2013 | B2 |
| 8498740 | Truttmann | Jul 2013 | B2 |
| 8498742 | Truttmann | Jul 2013 | B2 |
| 10864642 | Miyashita | Dec 2020 | B2 |
| 11135646 | Imahase | Oct 2021 | B2 |
| 20100017027 | Truttmann | Jan 2010 | A1 |
| 20170045106 | Kendrick | Feb 2017 | A1 |
| 20200038944 | Imahase | Feb 2020 | A1 |
| 20220040757 | Carosielli et al. | Feb 2022 | A1 |
| Number | Date | Country |
|---|---|---|
| 2002120051 | Apr 2002 | CN |
| 101553334 | Oct 2009 | CN |
| 101612663 | Dec 2009 | CN |
| 213002623 | Apr 2021 | CN |
| 10 2009 050216 | Dec 2010 | DE |
| 2500150 | Sep 2012 | EP |
| 2547474 | Feb 2017 | EP |
| H04 66268 | Mar 1992 | JP |
| H07 60434 | Mar 1995 | JP |
| 07132484 | May 1995 | JP |
| H07124885 | May 1995 | JP |
| H08 19853 | Jan 1996 | JP |
| H0839233 | Feb 1996 | JP |
| 2018065184 | Apr 2018 | JP |
| 2008025562 | Mar 2008 | WO |
| WO 2017129563 | Aug 2017 | WO |
| 2018066284 | Apr 2018 | WO |
| 2018074424 | Apr 2018 | WO |
| Entry |
|---|
| Office Action issued in corresponding Japanese Patent Appln. No. 2021-535187, dated Dec. 5, 2023. |
| Office Action issued in corresponding Japanese Patent Appln. No. 2021-535187, dated Jul. 25, 2023. |
| Notice of Opposition issued in corresponding European Appln. No. 19820778.9, dated May 15, 2024 (with English translation). |
| Number | Date | Country | |
|---|---|---|---|
| 20220040757 A1 | Feb 2022 | US |
