CN215089793U - Rack changing cart for replacing and transporting racks of rolling mill and system thereof - Google Patents

Abstract

The utility model relates to a frame change dolly and its system for replacing and carrying the frame of rolling mill, frame change dolly (20) is the finish rolling mill who is used for rolling metal strip and wire, finish rolling mill has a plurality of 3 roller frames (12, 23) of arranging around each other along rolling direction. To ensure high availability and productivity of the rolling mill, a reliable stand replacement system is provided. The rack change trolley (20) allows a very compact design and ensures a safe and reliable transport of the racks (12, 23).

Description

Rack changing cart for replacing and transporting racks of rolling mill and system thereof

Technical Field

The utility model relates to a frame change dolly for replacing and carrying the frame of rolling mill. In general, a rolling mill has a plurality of rolling stands arranged behind one another in the rolling direction, wherein each of the rolling stands is equipped with three rolls which surround the rolling axis in a 120 ° star.

Rolling mills equipped with 3-roll stands are mainly used for producing oblong products like bars or wires.

Background

In rolling lines for long products, for example for bars or wires, steel is passed from a heating furnace through a large number of individual roll stands as the material of the long product until a product with the desired tolerances of the final dimensions is obtained after rolling through the roll stands.

To achieve high quality (in particular, tight tolerances) of rolled material, compact multi-stand rolling mills with 3 roll stands are usually installed in such rolling lines and at the last position of the line.

This last so-called "finishing-rolling mill" has a very compact design, in which several stands (usually four to five stands) are arranged behind one another with the smallest possible spacing between them.

This compact design is desired in order to achieve the highest quality finished product possible.

Since the diameter of the bar decreases with passing through each roll stand in the rolling line, the rolling speed increases at the same rate. Consequently, high rolling speeds of 20m/s or even higher occur in "finish rolling mills", which also cause correspondingly high roll wear. This roll wear causes the need for frequent roll stand replacement. Furthermore, when changing the size of the finished product, the racks must be replaced with other racks adjusted to the desired size.

For this reason, the stands of the "finishing mill" must usually be replaced several times a day. The "used" stand must be removed from the mill and a "new clean" stand must be placed on site.

Such replacement or substitution of the rolling stands of the rolling mill is called "stand change" and must be carried out regularly, sometimes at very short intervals of less than one hour. During this time, production is interrupted, which results in a loss of production. For this reason, it is very important that the rack change is completed as quickly as possible within a few minutes, for example within 3-4 minutes, so that production can continue after only a brief interruption.

The frame changing trolley plays an important role in the frame changing process. The newly prepared "clean" stands are transported to the mill on the stand exchange cart and the "used" stands are transported away from the mill. Usually, two independent stand-changing carriages are in operation, alternately moved to a stand-changing position in front of the rolling mill. To ensure a safe and barrier-free rack change process, the rack change trolley in the rack turning position in front of the rolling mill must be positioned accurately and also kept in this position, since the friction is high when pushing or pulling the rack upwards.

In addition, it is important that the frame is correctly positioned on the frame exchange trolley with a tolerance of only a few millimetres (e.g. 2-5 mm). This is necessary for the following operations: as described in CN104971944a, the hooks of the stand extraction units are hung to be correctly coupled to the respective stands so as to be able to draw the stands into the stand base in the rolling position. Correct and accurate positioning of the gantry on the gantry change cart is also important for the following operations: preventing collision with components of the extraction unit of the stand and preventing damage to the stand when moving it in front of the rolling mill.

Another requirement of a rack change trolley is that the rack on the trolley cannot slide out of the rack change trolley or leave its predefined position during the stopping process, in particular in case an emergency stop is required. Dropping the rack from the rack change trolley can be dangerous for the operator due to the weight of the rack in tons (e.g. 3t to 8 t).

CN 202021954590.9 discloses a rack change cart in its fig. 1, for example. This known rack exchange trolley 1 is provided with a rack displacement device 2. The frame displacement means may laterally displace the frame 3 by means of a frame displacement beam located at the top of the body of the frame exchange trolley. The prior art design of a rack change trolley is particularly wide, because the displacement beams require extra space, and the rack also requires a wide surface area, so that the rack cannot slip off the trolley in case of an emergency stop. This extra space is also required because the frame cannot be placed particularly accurately on the frame changing trolley by means of the crane.

SUMMERY OF THE UTILITY MODEL

According to the utility model discloses, frame change dolly includes retaining device, retaining device has the locking mechanical system that can release of positioning and keeping the frame on frame change dolly.

Compared with the prior art, the utility model provides a show compacter frame change dolly, even the reason is under the condition of promptly stopping, the frame also can firmly keep on frame change dolly, just the utility model discloses frame change dolly ensures the accurate positioning of frame on frame change dolly. The rack change cart does not require an external power source, for example from a cable chain. Nor is a shifting beam required for replacing the rack. When using a rack extraction device such as described in CN104971944a, another displacement beam is superfluous. As an alternative to the rack extraction device described in CN104971944a, alternative configurations are also conceivable.

Preferably, the system of a stand exchange trolley, a stand and a rolling mill comprises a stand extraction device integrated in the stand base of the rolling mill, said extraction device comprising a slideway, a drive mechanism for moving said slideway along a linear path, and a releasable connection mechanism for moving a stand from a stand exchange trolley to a stand base, wherein said stand is placed in a rolling position or said stand is moved from said stand base to said stand exchange trolley.

Preferably, the rack extraction device is attached to the rack on the side facing the rack base 10.

This stand extraction device may be designed as a hook or eyelet which may be detachably engaged with a corresponding eyelet or hook attached to or integrated in the stand base in order to pull the stand into the rolling position or push it from the rolling position onto the stand change cart.

The releasable connection mechanism preferably comprises a pivotable hook attached to the slideway and an eyelet attached to the frame. Alternatively, the releasable connection mechanism preferably comprises an eyelet attached to the slideway and a pivotable hook attached to the chassis.

The releasable connection between the rack and the rack extraction means may be manually operated, for example by moving a hook, or may also be automated without any action by the operator. Such an automated technical solution is described, for example, in CN 104971944A. The gantry extraction means can be released or connected to the gantry by a two-dimensional movement in the transfer position.

The technical solution of the rack extraction device according to the preferred embodiment, which comprises e.g. a spindle drive, a slide and a manually operated pivotable hook integrated in the rack base, and a corresponding eyelet mounted to the rack, is for moving the rack into or from the rack base from or to the rack change trolley, which may not be provided with such a displacement device. Alternatively, the eyelet may also be attached to the slide and the hook may be attached to the frame. In order to avoid manual intervention by an operator, the opening of the hook for releasing the chassis in the transfer position may be automated, for example, by a pneumatically operated actuator.

Another option is to design the perforations in the following way: the transverse bracket is bent so that when the rack change cart is moved laterally with the rack thereon, the eyelet is moved out of the area of engagement with the hook and thereby releases the rack.

This preferred design of the detachable connection between the rack and the rack extraction device integrated in the rack base enables a very compact construction of the rack change trolley. However, it is also necessary that the gantry is positioned very precisely on the gantry change trolley so that the gantry extraction apparatus can be coupled to the gantry. Depending on the configuration of the rolling mill, the stand changing trolley is for example loaded and unloaded laterally to a position next to the rolling mill or by a crane in the rolling mill workshop. It must be ensured that the gantry is positioned on the gantry exchange trolley with an accuracy of preferably only a few millimetres. Due to the need for an ultra-long travel distance, the rack change cart cannot be easily coupled to the energy supply, as is typical for moving rack change carts through a cable system. Therefore, a mechanical solution is preferred, wherein the operator can easily recognize the correct positioning of the gantry on the gantry change trolley to prevent incorrect positioning. Furthermore, it is advantageous to prevent any slippage of the frame during the braking and acceleration process of the frame changing trolley, precisely maintaining the position of the frame on the frame changing trolley for safe transfer to the frame extraction device.

According to a preferred embodiment of the rack change trolley, the rack change trolley comprises a support plate, wherein the holding means comprises a plurality of hooks, a pivotable shaft to which the hooks are attached, a plurality of bearing points carrying the pivotable shaft and mounted to the rack change trolley at a position below said support plate, and a toggle-link system mounted to the outside of the rack change trolley and connected to the pivotable shaft.

It is further preferred that the rack change trolley comprises two toggle link systems mounted to the rack change trolley, wherein each of said two toggle link systems is mounted to one of two laterally opposite sides and connected to one of two longitudinal ends of the pivotable shaft.

According to a further preferred embodiment, the holding means are held in a first holding position by means of a toggle system, so that incorrect placement of the rack does not push away said holding means. Optionally and preferably, the toggle lever system is biased into a straight position as a holding position by a spring element and held in said straight position such that the holding means is not opened unintentionally.

More advantageously, each of the toggle link systems comprises three toggle links connected to each other via joints, wherein in the support plate of the rack change trolley a first one of the toggle links is rotatably connected to the pivotable shaft via a first one of the joints, a second one of the toggle links is rotatably connected to the support plate of the rack change trolley via a second one of the joints, and a third one of the toggle links is connected to the first and second levers via a third one of the joints and is configured to be lowered through the opening. Here, the locking mechanism preferably additionally comprises at least one locking device with a hydraulically actuated locking bolt, wherein the third toggle lever of at least one of the toggle lever systems is configured to be moved by the locking bolt in such a way that the toggle lever system leaves a straight position and to rotate the pivotable shaft to move the attached hook out of engagement with any chassis on the chassis exchange trolley held by the locking mechanism.

A plurality of hooks are preferably mounted on the rack change trolley such that the hooks can be rotated in and out.

Preferably, the hook of the releasable locking mechanism of the rack change trolley is configured to engage with a groove of the rack, which groove is preferably only slightly wider than the hook, preferably 2-20mm wide, so that the rack can be positioned on the rack change trolley with corresponding accuracy by means of the engagement of the hook and the groove.

The channel may preferably be located on the underside of the chassis. This ensures that the rack does not slip out or fall off the rack replacement trolley even in the event of an emergency stop of the rack replacement trolley.

The hooks are preferably attached in pairs for each frame orientation on a common connecting axis which is supported several times on the underside of the frame exchange trolley, in particular the underside of the support plate of the frame exchange trolley.

The stopper is preferably provided on the rack replacement trolley to facilitate positioning of the rack on the rack replacement trolley by using a crane. The stopper is preferably located at a predetermined distance from the hook, wherein the predetermined distance is 2-20mm greater than the distance between the groove of the frame and the stopper. The stop is not absolutely necessary but advantageous. The distance between the hooks, the stops and the grooves on the underside of the frame is chosen such that the frame must be lowered by the crane onto the frame changing trolley with an accuracy of a few millimetres, for example 3-15 mm. In order to make it easier to fix the frame in this position, for example by screwing it onto a frame changing trolley, the stop can be provided with a ramp.

If the frame is not placed in the correct position on the frame changing trolley, the frame rests on the stops or on top of the hooks and is in a clearly inclined position.

In this way, the operator knows that the rack is incorrectly placed on the rack change trolley. However, this requires that the hook remains in its rotated-out position in the case of loading from above, regardless of the force with which the hook is loaded when the rack is incorrectly lowered. To ensure this, the locking mechanism may be provided with a toggle lever system as outlined above. This pivotable shaft extends over the entire width of the rack change trolley, preferably attached to the underside of the support plate of the rack change trolley by means of a plurality of sliding bearings. If the toggle lever system is in the straight position, the hook is in the locked position. This prevents the hook from leaving its position due to forces acting on it. To rotate the hook out of the locked position, the toggle lever is moved out of the flat position against the spring force. Preferably, this is done by means of stay-on bolts embedded in the floor of the hall in which the rolling mill is installed. Such stay bolts are usually embedded in the lobby floor on both sides of the rack change cart and have the task of holding the rack change cart in place in front of the rolling mill during the rack change process. Such a stay bolt is described in, for example, CN 202021954590.9.

According to a preferred embodiment, the stay bolt has another task. The central joint of the toggle link system may be provided with another element which sinks into the opening of the rack changing trolley provided for the stay bolt of the rack changing trolley. If the stay bolt, which is usually hydraulically actuated, for the rack change trolley is moved upwards in order to fix the rack change trolley firmly in the swivel position, the toggle lever system is pushed open against the spring force at the same time and the hook is thus swiveled out of its locking position.

The chassis can thus be released from the chassis exchange trolley and can be pulled into the chassis base or pushed onto the chassis exchange trolley. If the rack change cart is moved with the rack on it, the stay bolt is first retracted to release the rack change cart. The spring attached to the toggle-lever system then brings the toggle lever back into the straight position and the hook securing the rack on the rack change trolley is moved up again into its locking position.

Drawings

Fig. 1 shows a prior art rack change cart.

Fig. 2 shows the stand base of a typical rolling mill.

Fig. 3 shows the chute to which the pivotable hook is mounted.

Figure 4 shows the slideway with the eyelet mounted thereto.

Fig. 5 shows the chute to which the pivotable hook is mounted.

Fig. 6 shows a preferred embodiment of the rack change cart.

Fig. 7 shows the underside of the rack change cart.

Fig. 8 shows a releasable locking mechanism.

Fig. 9 shows a toggle lever system.

Fig. 10 shows a rack according to a preferred embodiment.

Fig. 11 shows the frame positioned on a frame exchange trolley according to a preferred embodiment.

Fig. 12 shows the frame positioned on a frame exchange trolley according to a preferred embodiment.

Detailed Description

Fig. 1 shows a prior art frame exchange trolley 1 with a corresponding frame 3 and an integrated displacement device 2.

Fig. 2 shows the stand base 10 of a typical rolling mill with stand 12 now moved to a stand exchange cart 20. The hook 14 is mounted to a slideway 17 driven by the spindle drive 11, wherein the hook engages with an eyelet 13 connected to the frame 12. This spindle drive 11 is integrated in the stand base 10 of the rolling mill.

Fig. 3 shows the slideway 17 to which the pivotable hook 14 is mounted, said pivotable hook 14 engaging in the eyelet 13 of the frame 12. Position 11 indicates the spindle drive of the slide 17.

Fig. 4 shows that eyelet 13 is mounted to slide 17 and frame 12 has pivotable hook 14 coupled to eyelet 13. Position 11 indicates the spindle drive of the slide 17.

Fig. 5 shows the slide 17 to which the pivotable hook is mounted, said pivotable hook engaging in the eye 13 of the frame 12. This eyelet 13 has a bent bracket 15 so that when the frame changing trolley 20 is moved sideways together with the frame 12, the eyelet 13 moves out of the engagement area with the hook 14, thereby releasing the frame 12. Position 11 indicates the spindle drive of the slide 17.

Fig. 6 shows a rack change trolley 20 according to a preferred embodiment provided with a releasable locking mechanism to position and hold the rack 23 on the rack change trolley 20. The releasable locking mechanism comprises a pivotable hook 21 which correctly positions the frame 23 on the frame exchange trolley. The rack change trolley is additionally provided with a stopper 35, said stopper 35 having a ramp 36 to support the process of loading the rack 23 on the rack change trolley 20.

Fig. 7 shows the underside of the support plate of the rack change cart 20. Position 25 indicates the bearing point of the pivotable shaft 26 to which the hook 21 is firmly mounted.

Fig. 8 shows a releasable locking mechanism according to this embodiment as part of the rack change cart 20. This locking mechanism comprises a pivotable shaft 26, a plurality of hooks 21 to which the pivotable shaft 26 is fixedly mounted, and a toggle system 24. Position 25 shows the various bearing points, in particular the support plates, by which the locking mechanism is mounted to the rack change trolley 20. Position 27 shows the spring element of the toggle lever system 24. Position 31 shows a first lever mounted to the pivotable shaft 26 via a first joint 33. Position 32 shows a second lever connected to the rack change trolley 20 via a second joint 34. Position 29 shows the third lever sinking through opening 30. Position 28 shows the third central joint to which all levers are connected.

Fig. 9 shows the toggle lever system 24 in detail. Position 27 shows the spring element of the toggle lever system 24. Position 31 shows a first lever mounted to the pivotable shaft 26 via a first joint 33. Position 32 shows a second lever connected to the rack change trolley 20 via a second joint 34. Position 29 shows the third lever sinking through opening 30. Position 28 shows the third central joint to which all levers are connected.

Fig. 10 shows a chassis 23 according to this embodiment having a groove 22 engageable with a hook 21 of a releasable locking mechanism.

Fig. 11 shows a rack 23 positioned on a rack change cart 20 according to a preferred embodiment. The releasable locking mechanism is engaged and the frame 23 is fixed to the frame change trolley 20 between the hook 21 and a stop 35, said hook 21 being turned to engage with the groove 22 of the frame 23, said stop 35 preventing the frame from moving out of the frame change trolley 20 during transport. The toggle system 24 is shown in a straight position. Position 16 shows the locking unit 16 holding the stand exchange trolley 20 in front of the rolling mill during the stand exchange process. Position 30 shows an opening 30 as part of the positioning system of the rack change cart 20. Position 26 shows the pivotable axis, position 21 shows the hook, and position 24 is the toggle lever system of the releasable locking mechanism.

Fig. 12 shows a chassis 23 according to this embodiment positioned on a chassis exchange trolley 20. The releasable locking mechanism is released. The toggle system 24 is in the open position. The hydraulically actuated positioning and holding bolt 18 of the gantry trolley positioning system moves upwards and pushes against the lever 29 against the spring force. This latches the toggle lever system 24, turning the pivotable shaft 26 and releasing the catch 21 from the groove 22. In this configuration, the stand 23 is ready to be pulled out of the stand exchange trolley 20 into the stand base 10 of the rolling mill.

List of reference marks

1 rack replacing trolley in prior art

2 rack shift device mounted on rack replacing trolley (prior art)

3 Rack without groove (prior art)

10 frame base

11 spindle drive

12 grooved frame

13 eyelet

14 hook

15 bracket

16 locking unit

17 slideway

18-stay bolt

20 rack replacing trolley

21 hook

22 groove

23 frame

24-toggle lever

25 bearing point

26 pivotable shaft

27 spring element

28 third center connection

29 third lever

30 opening

31 first lever

32 second lever

33 first joint

34 second joint

35 stop dog

36 slope.

Claims (16)

1. A stand changing trolley (20) for replacing and transporting stands (12, 23) of a rolling mill,

characterized in that the rack change cart (20) comprises a holding device with a releasable locking mechanism to position and hold the rack (12, 23) on the rack change cart (20).

2. Rack changing trolley (20) according to claim 1, characterized in that it comprises a support plate and that the holding means comprise a plurality of hooks (21), a pivotable shaft (26) to which the hooks (21) are attached, a plurality of bearing points (25) carrying the pivotable shaft (26) and mounted to the rack changing trolley (20) at a position below the support plate, and a toggle lever system (24) mounted to the outside of the rack changing trolley (20) and connected to the pivotable shaft (26).

3. The rack change cart (20) according to claim 2, characterized in that it comprises two toggle-link systems (24) mounted to said rack change cart (20), wherein each of said two toggle-link systems is mounted to one of two laterally opposite sides and is connected to one of two longitudinal ends of said pivotable shaft (26).

4. A rack change trolley according to claim 3, characterised in that the holding means are held in a holding position by the toggle-link system (24) so that incorrect placement of a rack (12, 23) does not push away the holding means.

5. Rack changing trolley according to claim 4, characterized in that the toggle lever system (24) is biased into a straight position as the holding position by means of a spring element (27) and is held in the straight position such that the holding means is not opened unintentionally.

6. Rack changing trolley according to claim 5, characterized in that each of the toggle-link systems (24) comprises three toggle links (29, 31, 32) connected to each other via joints (28, 33, 34),

wherein in the support plate of the rack change cart (20) a first one (31) of the toggle links (29, 31, 32) is rotatably connected to the pivotable shaft (26) via a first one (33) of the joints (28, 33, 34), a second one (32) of the toggle links (29, 31, 32) is rotatably connected to the support plate of the rack change cart (20) via a second one (34) of the joints (28, 33, 34), and a third one (29) of the toggle links (29, 31, 32) is connected to the first and second levers (31, 32) via a third one (28) of the joints (28, 33, 34) and is configured to be lowered through an opening (30).

7. Rack changing trolley according to claim 6, characterized in that the locking mechanism additionally comprises at least one locking unit (16) with a hydraulically actuated stay bolt (18), wherein the third toggle link (29) of at least one of the toggle link systems (24) is configured to be moved by the stay bolt (18) in such a way that the toggle link system (24) leaves the straight position, and to rotate the pivotable shaft (26) to move the attached hook (21) out of engagement with any rack (23) on the rack changing trolley (20) held by the locking mechanism.

8. The rack change trolley (20) according to claim 2, characterized in that the hook (21) of the releasable locking mechanism of the rack change trolley (20) is configured to engage with a groove (22) of the rack (12, 23).

9. A system of at least one of a rack change trolley and a rack (12, 23) according to claim 8, characterized in that the width of the groove (22) of the rack (12, 23) is 2-20mm wider than the width of one of the hooks (21) of the holding device, so that the rack can be positioned on the rack change trolley (20) with corresponding accuracy by means of the engagement of the hooks (21) and the groove (22).

10. System according to claim 9, characterized in that a stopper (35) is attached to the frame change trolley (20), the stopper (35) being located at a predetermined distance from the hook (21), wherein the predetermined distance is 2-20mm greater than the distance between the groove of the frame (12, 23) and the stopper (35).

11. System according to claim 10, characterized in that the stop (35) is provided with a ramp (36) to simplify loading of the rack change trolley (20).

12. A system of a stand change trolley (20), a stand (12, 23) and a rolling mill according to claim 1, characterized in that it comprises a stand extraction device integrated in a stand base (10) of the rolling mill, which extraction device comprises a slideway (17), a drive mechanism for moving the slideway (17) along a linear path, and a releasable connection mechanism for moving the stand (12, 23) from the stand change trolley (20) to the stand base (10), wherein the stand (12, 23) is placed in a rolling position or the stand (12, 23) is moved from the stand base (10) to the stand change trolley (20).

13. System according to claim 12, characterized in that the drive mechanism comprises a spindle drive (11) integrated in the frame base (10).

14. The system of claim 12, characterized in that the releasable connection mechanism comprises a pivotable hook (14) attached to the slideway (17) and an eyelet (13) attached to the frame (12, 23).

15. The system according to claim 12, characterized in that the releasable connection mechanism comprises an eyelet (13) attached to the slideway (17) and a pivotable hook (14) attached to the frame (12, 23).

16. The system according to claim 14, characterized in that the releasable connection comprises a pivotable hook (14) and an eyelet (13) with a curved bracket (15), wherein the bracket (15) is configured to allow the hook (14) to slide out of the eyelet (13) when the chassis exchange cart (20) is moved sideways, thereby releasing the chassis (12) from the connection.

Images