Main girder of a bridge crane

Abstract

A main girder (2) of an overhead travelling crane, which is intended to be supported by its end to an end beam of the overhead travelling crane and comprises an elongated box-shaped central web (6), whereby in the central web (6) on at least one end of the main girder (2) a cut-out (9) is formed, which extends essentially in the longitudinal direction of the main girder (2), there is a blade (10) connected to the cut-out (9), which extends essentially from the bottom (9a) of the cut-out (9) to the end of the main girder (2) for supporting the end beam.

Description

BACKGROUND

[0001] The present invention relates to a horizontal main girder of a bridge crane, which girder is intended to be supported by its end terminal to the end beam of the crane and which comprises an elongated box-like central web.

[0002] There are several different methods to modify the main girder of a bridge crane in its end region. In this context, the need for various types of end support is generated by different requirements of the drive guide of the crane. The most common ways to implement the end support for the main girder are the so-called "top connection", in which the main girder supports its entire height on the end support, and the so-called "top medium connection", in which only a part of the height of the main girder is on the end support. With the latter solution, the main girder can fit in a narrow space, and additional space can be created by different types of "lateral transfer", such as pipes, electrical wires, etc. in the end region near the crane track. In addition, "side connection" supports are used, in which the main girder is supported to one side of the end support.

[0003] The typical prior art "top medium connection" solution comprises various vertical narrow pieces and reinforcing joints at the end of the main girder. In this case, the manufacture of the joints is laborious. Placing different kinds of joint plates is time-consuming at the manufacturing stage, as some plates are provided with bevels, the joints can comprise several reinforcing plates, and many plates have different dimensions. Some welds can be in challenging positions from the manufacturing point of view. Each joint must be designed individually to meet the strength technology requirements. Modifying the dimensions according to the required space causes the need to redesign the joint in question each time according to the thickness, angle and dimensions of the plates to be used. No joint type can meet the multiple needs regarding the height and lateral transfer. All these parameters must be selected according to the application and needs in question at the moment. SUMMARY

[0004] The object of the present invention is to eliminate the above-mentioned drawbacks and problems in implementing the support to the end of the main girder. This object is achieved by the main girder of the invention, which is characterized in that a cut-out is formed in the central web at at least one end of the main girder, which cut-out extends essentially along the longitudinal direction of the main girder, and there is a knife plate connected to the cut-out, which knife plate extends essentially from the bottom of the cut-out to the end of the main girder for supporting the end beam.

[0005] When the main girder is supported on the end beam, the bottom side of the knife plate is essentially free of the central web for said support over a certain length from the end surface of the main girder.

[0006] The preferred embodiments of the invention are disclosed in the dependent claims.

[0007] The solution according to the invention is an adaptive robot that is transferred in the vertical direction and sideways on a broad area. This makes it possible to meet the requirements in each case as well as possible and provides a better solution than previously. A great advantage of the invention is also that both the end of the central web or the final form of the plate for the central web and the cutouts made in it can be cut out in one go using the same plasma, laser or water cutting without any intermediate steps. Specific thresholds of the structure can be set for both the height and the sideways transfer, in which the structure can be changed freely without the need for strength calculations separately each time. The solution allows the manufacture of asymmetric main girders without the need for compromises in sufficient strength or transport guide times.

[0008] The ends of the main girder are manufactured as easily as possible, because all the parts needed can advantageously be welded in place from the outside of the central web, and the working position of the welder is suitable for each weld they make. The welder does not need to inhale welding gas related to internal welding. The welder and the inspector have easy access to the welds. The solution described is advantageous for both manual welding and automatic welding. The joints appear in the form of fillet joint, so there is no need for welds that need to be penetrated. In the optimal operating area of the end form, the welds are formed with one bead, making the manufacture faster.

[0009] The invention allows the transfer of the forces resulting from the hoisting load and the weight of the crane itself between the end of the main girder and the critical transfer zone of about one or two meters in length from the end towards the central part of the main girder. BRIEF DESCRIPTION OF DRAWINGS

[0010] In the following, the invention will be explained in more detail in connection with the preferred embodiments and with reference to the appended drawings, in which:

[0011] Figure 1 is a top view of a simplified bridge crane;

[0012] Figure 2 is Figure 1 is a side view of the bridge crane of

[0013] Figure 3 is a side view of the end of the main girder of the invention of the bridge crane, in which the end is supported on the main girder;

[0014] Figures 4a to 4d shows the end of the main girder of the invention with different shapes, in which the end is supported on the main girder;

[0015] Figure 5 is a side view of the end of the main girder of the invention of the bridge crane, in which the end is supported to the side of the main girder;

[0016] Figure 6shows a partial horizontal cross-section from above the knife plate at the end of the main girder according to the preceding figures;

[0017] Figure 7 is a plan view of the basic shape of the knife plate; and

[0018] Figure 8a and Figure 8b shows a transverse inner intermediate plate of the end of the main girder. DETAILED DESCRIPTION

[0019] Reference is first made to Figure 1 and Figure 2 The main components of the bridge crane 1 are a horizontal main girder 2; end girders 3 which are transverse to the main girder 2 with respect to which both ends of the main girder 2 are supported; rails 4 along which the end girders 3 are run by their wheels (not shown) along the sides of the crane space A; and a trolley 5 which moves along the main girder 2, which trolley has a hoisting device (not shown). The crane space A next to and around the rails 4 is usually limited, and the invention solves the problems caused by this space limitation. There can be several main girders 2 in parallel, whereby the trolley 5 can be supported by several main girders 2.

[0020] In addition to Figure 3 the main girder 2 comprises in the structure of the invention an elongated box-shaped central web 6, and an elongated top flange 7 or top plate, usually on its top surface, and an elongated bottom flange 8 on the bottom surface, on which the trolley 5 of the present example runs when supported on the bottom flange 8. The trolley 5 can also be supported to the top flange 7. In both cases, it can also be supported to the side surfaces of the central web 6. In Figure 8a and Figure 8b The web 6A of the central web 6 is interconnected with intermediate plates 16 and 17, which can be welded from the outside through intermittent openings 19 reserved for this purpose, as shown in Figs. 16 and 17. The intermediate plates 16, 17 have outwardly protruding protrusions which fit in the openings 19 in combination with the central web 6, and the protrusions are welded in the openings 19 from the outside of the main girder. In the same way, the partitions 16, 17 can advantageously be welded to the top flange 7 by means of a tongue.

[0021] On both ends of the central web 6, i.e. of the main girder 2, there is formed a cutout 9 extending horizontally along the longitudinal direction of the main girder 2, and there is a knife plate 10 connected to this cutout 9, which extends from the bottom 9a of the cutout 9 to the end of the main girder 2 for supporting the end girder 3, whereby the bottom side of the knife plate 10 is essentially free of the central web 6 over a certain length from the end surface of the main girder 2 for said support.

[0022] From the end surface of the main girder 2 over a certain length on the bottom side of the knife plate 10, a part of the central web 6 has been cut to a certain shaped side profile P, forming a space 11 for ventilation ducts, cable racks, power tracks for cranes, etc.

[0023] Depending on the maximum weight to be placed on the main girder 2, the height of the part 6a of the central web 6 over the space 11, and thus the knife plate 10, is chosen. The minimum height of the part 6a can typically be about 1 / 5 of the total height of the central web 6, such as 150 mm. This ensures that the shear stresses caused by the weight of the main girder 2 and the trolley 5 as well as the load to be lifted can be managed, and that there is space for attaching the knife plate 10.

[0024] As Figure 3 is shown, if the space 11 is "two-piece" and has a space 11a extending to the bottom surface of the knife plate 10 and a space 11b in which the central web 6 extends a chosen depth below the knife plate 10, the minimum height of the central web 6 at this location depends on the length of the space 11b in the direction of the main girder 2 when the space 11 is typically only as wide as needed for the support of the end girder 3. When the areas 11a, 11b are mainly rectangular, it is simple to provide a design description thereof as well as the allowed main dimensions of the joint areas for various loading situations. It is also simple to mainly design the rectangular shape in sheet metal processing to manufacture the sheet metal. The position in the height direction of the knife plate 10 in the central web 6 as well as the shape and size of the space 11 thus depend entirely on the loading and application of the bridge crane 1 and can vary greatly, the key being the positioning of the cutouts 9 and the knife plate 10 therein, the subsequent intermediate plates 16, 17 and the reinforcing plate 13 at the end of the knife plate 10. In Figure 3 the space 11b on the right, a substantially vertical closure plate 20 is adapted between the bottom border on the bottom flange 8 and the web 6A on the top knife plate 10. In Figure 3 from left to right, this closure plate 20 is welded from the space 11b side with a uniform weld seam so that the weld forms the letter U. The bottom edge is placed on the bottom flange 8, the vertical part on the inner surface of the web 6A as high as allowed by the welding. The end plate 12 and the closure plate 20 close the end region of the main girder 2, but need not achieve a perfect seal. The volume defined in the structure by the spaces 11a, 11b, the knife plate 10 and the closure plate 20 is advantageously open at the bottom. The right-angled outer edge of the central web 6 shown at the joint of the spaces 11a, 11b and the inner edge defined by the radius of curvature at the edge of the space 11b can naturally be formed in various ways. The essence of the dimensions of the main girder 2 is to manage the total deflection of the main girder 2 within the allowed limits.

[0025] The support plate 15 can advantageously be connected to the free bottom surface of the knife plate 10 for supporting the end girder 3.

[0026] In the described example, end plates 12 are fixed to the end surfaces of the main girder 2 and to the ends of the blade 10, and in the area on the sides of the bottom 9a of the cutting groove 9, stress distribution reinforcement plates 13 are fixed on both sides of the central web 6, which reinforcement plates extend over the specified areas of the front, rear, top and bottom sides of the bottom 9a of the cutting groove 9. This reinforcement plate 13 serves to alleviate the stress concentration at the ends of the blade 10 and possibly also the surrounding stress concentration around the openings and gaps. The material thickness of the reinforcement plate 13 is advantageously the same as the material thickness of the web 6A. The reinforcement plate 13 is advantageously square or rectangular and it has longitudinal through openings 13a made in it. These openings 13a are advantageously placed horizontally in the assembly, i.e. in the direction of the length of the main girder 2. The size of the openings 13a is chosen so that when the reinforcement plate 13 is placed on the central web 6, a fillet weld can also be formed horizontally at the top and bottom edges of the openings 13a. The outer edges of the reinforcement plate 13 need to be welded. This weld is slightly similar to a plug weld for the size of the elongated opening 13a in the direction of the main girder 2, but differs from the plug weld in that two parallel corner welds are sufficient and the entire open space of the opening does not need to be filled with a weld. The goal is to make welding and placing the welding tool easier so that the top flange 7 is not in the extension of the welding tool or hand. The bottom edge of the end plate 12 advantageously extends downwards, whereby an edge support can be formed to laterally support the support plate 15. When using a sliding joint as described in patent application PCT / FI2019 / 050298, the range of movement and / or the twisting of the joint in question can also be limited by supporting or limiting the gap from the lateral direction by means of the downwardly extending end plate 12. In the sliding joint, the possibility of the main girder 2 falling off the end girder 3 can also be prevented by means of the end plate 12. The main task of the end plate 12 is to block the box structure of the main girder and to reinforce the structure to some extent at that location. The end plate 12 is more important in the following “side connection” solution, which will be described in the following Figure 5

[0027] ​The fastening of the blade plate 10, the end plate 12 and the stiffener 13 is most advantageously carried out by welding. The blade plate 10 is advantageously welded to the central web 6 over its entire length, thus on the top side and on the bottom side. The stiffener 13 is placed on the welded blade plate 10 and is welded in place by making horizontal fillet welds (e.g. 2+2) on the edges of the open slot 13a, the blade plate 10 end being welded with a filler weld to the tip of the stiffener 13.

[0028] In addition, advantageously a protrusion 14 is formed in the web portion below the blade plate 10 which comes into contact with the bottom surface of the blade plate 10 and extends towards the end surface of the main beam 2. This protrusion 14 is significant from the point of view of the service life of the joint of the blade plate 10, because it reduces the stress concentration at the joint edge and prolongs the life of this part. The height of the protrusion 14 can be set constant, but it still has a minimum size. By setting a minimum value, the aim is to ensure that even when the welding heat tries to melt the protrusion on the edge, at least some of the protrusion 14 remains. Below the protrusion 14, there is a rounded recess with a 90-degree arc length, in which a standard radius of curvature can advantageously be used, even though the design of the end region is typically different from the needs of the space 11.

[0029] When the blade plate 10 and the bottom flange 8 have essentially the same thickness, the blade plate 10 in a sense acts as an extension of the bottom flange 8 in this part area, i.e. the space 11, cuts the central web 6 from below the blade plate 10 and functions over a longer area to bring the load on the main beam 2 to its end. From the point of view of transferring the load, a longitudinal lap in the length direction of the main beam 2 can be dimensioned s1, which is limited on the one hand by the joint of the central web 6 seen from the tip flanks of the trapezoidal outer side of the blade plate 10 at the stiffener 13 and on the other hand by the joint between the central web 6 and the bottom flange 8 at the outermost point of the end near the end beam 3 side. The lap dimension s1 can be 200 mm to 1000 mm. The blade plate 10 advantageously cuts plates that are thicker than the web 6A or the stiffener 13, whereby the edges of the blade plate 10 can remain uneven or different from a right angle with respect to the flat surface (the top of the bottom surface). In this case, it is advantageous that no complex form is made on the edges of the blade plate 10 or that it is not necessary to connect precisely to these edges. As shown in Fig. 6, for example, in this case the blade plate 10 is justified by its flat connection, as is the top of the bottom surface. Similarly, possible slots are more preferably manufactured in thin plates, such as the central web 6 and the stiffener 13. Figure 3

[0030] ​When the grooving-blade structures 9 and 10 of the present invention are located at the two ends of the main beam 2, these structures 9 and 10 need not be identical, but they can be manufactured according to customer requirements and applications. If there are multiple side-by-side main beams, such as two main beams, to support the trolley 5, the main beams can form up to four different ends if needed.

[0031] Figures 4a to 4b The different shapes of the ends of the main beam 2 are illustrated by way of example, demonstrating how this invention can be implemented. The connection areas of the main beam 2 do not need to be similar at both ends. Depending on the customer's space requirements, [the following can be done]... Figure 3 Region 11b is modified separately to connect the two connection regions of the main beam 2. It is noteworthy that the end beams 3 at both ends of the main beam 2 have the same support height, ensuring that the main beam 2 does not tilt. In some cases, the main beam 2 of a bridge crane, gantry crane, or semi-gantry crane is adapted to move on a track 4 at two different height positions. Even in this case, the main beam 2 or a portion thereof is substantially horizontal.

[0032] The blade 10 is advantageously rectangular, narrowing into a trapezoidal shape at its ends. The width of the blade 10 on its rectangular portion is advantageously two to four times the distance between the webs 6A. The blade 10 is advantageously no wider than the width of the bottom flange 8. The thin tip of the trapezoid can be substantially the same as the distance between the webs 6A of the central web 6. The tip can show a forward-projecting protrusion on its front side, the width of which substantially corresponds to the width between the inner surfaces of the webs 6A. This protrusion makes the assembly of the webs 6A easier to manufacture. As an alternative embodiment of the blade 10, instead of a trapezoidal tip, a forked tip may be present, where the branches of the fork become more gradual within the main beam 2, and the localized stress peaks on the flanks of the webs 6A can be homogenized over the corresponding joint length. For example, the fork can be shaped as a parabola, where the parabola opens toward the central portion of the main beam 2. In this embodiment, the reinforcing plate 13 can be omitted advantageously. On the other hand, in the assembly, the protrusion at the tip of the trapezoid cannot be used. The blade 10 is advantageously a plate-like material having a similar material within the main beam 2, and an internal connection between the central web 6 and the slot 9 manufactured in the blade 10. Due to this structure, the blade 10 can internally support the central web 6 and transfer forces between the central web 6.

[0033] like Figure 5As shown, the main girder 3 according to the present application can alternatively be connected to the side of the end plate 12, forming a so-called "side connection" fastening. In this case, the material thickness of the end plate 12 is chosen thicker than in the first described "top medium" fastening, and the end plate 12 is also wider (i.e. longer in the direction of the end girder 3) to form the bolt joint between the end plate 12 and the end girder 3. In this "side connection" fastening, the space 11 can potentially be smaller than in the "top medium" fastening, as the end surface of the main girder 2 in the longitudinal direction of the main girder 2 faces away from the end girder 3 with the width of the end girder 3 compared to the "top medium" fastening.

[0034] The above description of the application is intended only to illustrate the basic idea of the application. However, a person skilled in the art can implement its details within the scope of the appended claims.

Claims

1. A main girder (2) of a bridge crane, which main girder is intended to be supported by its ends to end girders (3) of the bridge crane (1) and comprises an elongated box-shaped central web (6) having vertical webs (6A), characterized in that, A kerf (9) is formed in the web (6A) of the central web (6) at at least one end of the main girder (2), the kerf (9) extending substantially in the longitudinal direction of the main girder (2), there is a blade (10) connected to the kerf (9), the blade extending substantially from the bottom (9a) of the kerf (9) to the end of the main girder (2) in the horizontal plane for supporting the end girder (3).

2. The girder of claim 1, wherein A part of the central web (6) has been cut on the bottom side of the blade (10) over a certain length from the end surface of the main girder (2) to form a side profile (P) of a certain shape for forming a space (11) for ventilation ducts, cable racks, power rails of the crane, etc.

3. The girder of claim 2, wherein, The bottom side of the blade (10) is substantially free of the central web (6) over a certain length from the end surface of the main girder (2) for supporting the end girder (3).

4. The girder of claim 3, wherein, A support plate (15) is fixed to the free bottom surface of the blade (10) for supporting the end girder (3).

5. The girder of claim 3, wherein, An end plate (12) is attached to the end surface of the main girder (2) and the end of the blade (10).

6. The girder of claim 2, wherein, There is an end plate (12) attached to the end surface of the main girder (2) and the end of the blade (10), the end of the main girder (2) intended to be supported from the end plate to the end girder (3).

7. The girder of claim 5, wherein, Stress distribution reinforcement plates (13) are fixed on both sides of the central web (6) in the area on the side of the bottom (9a) of the kerf (9), the reinforcement plates extending over the specified areas on the front, rear, top and bottom sides of the bottom (9a) of the kerf (9).

8. The girder of claim 4, wherein, A protrusion (14) is formed in the web part under the blade (10) in contact with the bottom surface of the blade (10) and extending towards the end surface of the main girder (2).

9. The girder of claim 7, wherein, The fastening of the blade (10), the end plate (12) and the reinforcement plates (13) is carried out by welding.

10. The girder according to any one of claims 1-9, characterized in that, An elongated top flange (7) or top plate is arranged in the top part of the central web (6) and an elongated bottom flange (8) is arranged in the bottom part of the central web (6).

11. The girder of claim 10, wherein, The blade (10) and the bottom flange (8) are substantially equal in thickness.

12. The girder of any one of claims 1-9, wherein, A kerf (9) and a blade (10) are arranged at both ends of the main girder (2). A kerf (9) and a blade (10) are arranged at both ends of the main girder (2).

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