Construction method for replacing lower trolley of rake crane

Abstract

The invention discloses a construction method, particularly discloses a construction method for replacing a lower trolley of a rake crane, and belongs to the technical field of maintenance and repair construction processes of rake cranes. According to the construction method for replacing the lower trolley of the rake crane, the replacement workload is small, and the replacement time of the lower trolley can be greatly shortened. According to the construction method, a rake type crane bridge frame is arranged on a beam column of a workshop, a lower trolley is arranged on a main beam of the rake type crane bridge frame in a reciprocating motion mode in the length direction, and an upper trolley is arranged on the lower trolley in a reciprocating motion mode in the circumferential direction; the construction method comprises the following steps: jacking an upper trolley away from an old lower trolley through a jacking system, then dismounting the old lower trolley, and then mounting a new lower trolley needing to be replaced on a main beam of a rake crane bridge, and finally, the upper trolley falls back to a new lower trolley through the jacking system to complete the replacement work of the lower trolley of the rake crane.

Description

Technical Field

[0001] The invention relates to a construction method, in particular to a construction method for replacing a lower trolley of a rake crane, and belongs to the technical field of maintenance and repair construction technology of rake cranes. Background Art

[0002] In steel mills, rake cranes are used to transport and stack billets. These cranes consist of a bridge, an upper trolley, a lower trolley, and electrical controls. The upper trolley rides on a circular track within the lower trolley. The upper trolley primarily includes a crisscross frame, rake guide rods, a winch, a driver's cab, and an electrical compartment. Its primary function is to adjust the height of the rake hook, hook the billets, and then rotate them for cross-stacked stacking. The lower trolley operates in a linear motion, driving the upper trolley to deliver the billets to the desired location.

[0003] The 202# rake crane used to discharge the 1# square billet in a steel plant had cracks on its lower trolley body and needed to be replaced. To replace the lower trolley body, the upper trolley needed to be dismantled, and the rake hook, driver's cab, electrical room cables, electrical room, cross frame, guide rod and upper trolley connected to the upper trolley needed to be dismantled. The dismantling weight was about 68t, that is, the entire trolley had to be dismantled before the purpose of replacing the lower trolley could be achieved. The dismantling and restoration work was heavy and time-consuming, and could not be completed within the 7-8 days of the annual maintenance of the 1# square billet.

[0004] There is currently no patent document or relevant technology that can guide the information on the rapid replacement of the lower trolley of this rake crane. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a construction method for replacing the lower trolley of a rake crane, which has small replacement workload and can greatly shorten the replacement time of the lower trolley.

[0006] The technical solution adopted to solve the above technical problems is: a construction method for replacing the lower trolley of a rake crane, including a rake crane bridge arranged on the workshop beam column, the lower trolley is arranged on the main beam of the rake crane bridge and can be reciprocated in the length direction, and the upper trolley is arranged on the lower trolley and can be reciprocated in the circumferential direction. The construction method first uses a jacking system to lift the upper trolley away from the old lower trolley, then removes the old lower trolley, and then installs the new lower trolley to be replaced on the main beam of the rake crane bridge, and finally uses the jacking system to drop the upper trolley back to the new lower trolley to complete the replacement of the lower trolley of the rake crane.

[0007] Furthermore, when dismantling the old lower trolley, the old lower trolley is first cut into two parts along the assembly seam, and then the two halves of the old lower trolley are dragged away from the upper trolley position along the tracks on the main beam. Finally, the two halves of the old lower trolley are lifted to the workshop floor by a car crane to complete the dismantling of the old lower trolley.

[0008] The preferred embodiment of the above scheme is that before using the jacking system to lift the upper trolley off the old lower trolley, at least the guide rod and rake hook on the upper trolley are lowered to the workshop floor through the steel rope of the upper trolley itself, and then the jacking system is used to lift the upper trolley off the old lower trolley.

[0009] Furthermore, before the new lower trolley is hoisted onto the track of the main beam, the wheel set and transmission device on the old lower trolley are transferred and installed on the new lower trolley and hoisted after passing the test.

[0010] The preferred method of the above scheme is that when hoisting the new lower trolley, the new lower trolley that has passed the test is split into two parts along the assembly seam, and then the two halves of the new lower trolley are hoisted to the track of the main beam using a car crane, and finally the two halves of the new lower trolley are connected into a whole using a connecting plate and high-strength bolts to complete the replacement of the new lower trolley.

[0011] Furthermore, before using the jacking system to lift the upper trolley away from the old lower trolley, a jacking system is first made, and the jacking system at least includes a supporting top frame and a jacking drive assembly; during the jacking process of the upper trolley, the jacking drive assembly is connected between the supporting top frame and the main beam, and the upper trolley is fixed on the supporting top frame.

[0012] The preferred embodiment of the above scheme is that the supporting top frame includes at least a rectangular supporting frame composed of two supporting long beams and two connecting short beams, and the jacking drive assembly is connected between the four corners of the rectangular supporting frame and the main beam along the length direction of the two supporting long beams.

[0013] Furthermore, the jacking drive assembly includes four hydraulic jacks with a lifting force of not less than 80t, and each hydraulic jack is independently connected between the four ends of the two supporting long beams and the main beam.

[0014] The preferred embodiment of the above scheme is that the supporting top frame also includes two sets of dissipating force steel frames and four short-circuited heightening columns, and the four hydraulic jacks are respectively connected to the corresponding positions of the main beam through the four short-circuited heightening columns in cooperation with the two sets of dissipating force steel frames.

[0015] Furthermore, each set of force-dissipating steel frames includes a force-dissipating steel plate and a set of double I-beam force-dissipating beams welded from two I-beams. The force-dissipating steel plate is padded at the bottom of the double I-beam force-dissipating beam, and the short-circuit heightening column seat is connected to the corresponding position of the double I-beam force-dissipating beam. Through the cooperation of the short-circuit heightening column and the force-dissipating steel frame, the upper trolley is lifted to a height of not less than 200 mm from the old lower trolley through a hydraulic jack, and after being lifted into place, it is tightened by a fixed support top.

[0016] The beneficial effects of the present invention are as follows: the technical solution provided in this application is based on a rake crane bridge arranged on the beams and columns of the workshop, and is combined with the structural characteristics that the lower trolley is arranged on the main beam of the rake crane bridge and can be reciprocated in the length direction, and the upper trolley is arranged on the lower trolley and can be reciprocated in the circumferential direction. The construction method adopted in this application is to first use a jacking system to lift the upper trolley away from the old lower trolley, then remove the old lower trolley, and then install the new lower trolley that needs to be replaced on the main beam of the rake crane bridge, and finally use the jacking system to drop the upper trolley back to the new lower trolley to complete the replacement of the lower trolley of the rake crane. In this way, there is no need to dismantle the rake hook, driver's cab, electrical room cable, electrical room, cross frame, guide rod and upper trolley and other parts from top to bottom, and then replace the old lower trolley with a new lower trolley, and finally install the upper trolley, guide rod, cross frame, electrical room, electrical room cable, driver's cab and rake hook in the reverse order of dismantling. Instead, the upper trolley is directly lifted together with the accessories to a height at which the old lower trolley can be removed, and then the old lower trolley is replaced with a new lower trolley. After passing the test, the upper trolley is lowered back onto the new lower trolley together with the accessories to complete the replacement of the lower trolley. Not only is the replacement workload small, but the replacement time of the lower trolley can also be greatly shortened, and the replacement work can be completed within 7 to 8 days of the annual maintenance of 1# square billet. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a jacking system for raising an upper trolley involved in a construction method for replacing a lower trolley of a rake crane according to the present invention; Figure 2 A simplified structural diagram of a jacking system involved in the construction method for replacing the lower trolley of a rake crane according to the present invention; Figure 3 for Figure 2 Side view of Figure 4 for Figure 2 A top view of Figure 5 The present invention is a schematic diagram of the construction method for replacing the lower trolley of a rake crane, which involves pulling out the old lower trolley.

[0018] Marked in the figure are: lower trolley 1, main beam 2, upper trolley 3, track 4, supporting long crossbeam 5, connecting short crossbeam 6, hydraulic jack 7, force-dissipating steel plate 8, short-circuit heightening column 9, double I-beam force-dissipating beam 10, and fixed support 11. DETAILED DESCRIPTION

[0019] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 as well as Figure 5 The present invention provides a construction method for replacing the lower trolley of a rake crane, which has a small replacement workload and can greatly shorten the replacement time of the lower trolley. The construction method includes a rake crane bridge arranged on a workshop beam column, a lower trolley 1 arranged on the main beam 2 of the rake crane bridge so as to be reciprocatingly movable along the length direction, and an upper trolley 3 arranged on the lower trolley 1 so as to be reciprocatingly movable along the circumferential direction. The construction method first uses a jacking system to lift the upper trolley away from the old lower trolley 1, then removes the old lower trolley 1, and then installs the new lower trolley 1 to be replaced on the main beam 2 of the rake crane bridge. Finally, the upper trolley 3 is lowered back onto the new lower trolley 1 by the jacking system to complete the replacement of the lower trolley of the rake crane. The technical solution provided by this application is based on a rake crane bridge arranged on the beams and columns of the workshop, and is combined with the structural characteristics that the lower trolley is arranged on the main beam of the rake crane bridge and can move back and forth in the length direction, and the upper trolley is arranged on the lower trolley and can move back and forth in the circumferential direction. The construction method adopted in this application is to first lift the upper trolley away from the old lower trolley through the jacking system, then remove the old lower trolley, and then install the new lower trolley that needs to be replaced on the main beam of the rake crane bridge, and finally use the jacking system to drop the upper trolley back to the new lower trolley to complete the replacement of the lower trolley of the rake crane. In this way, there is no need to dismantle the rake hook, driver's cab, electrical room cable, electrical room, cross frame, guide rod and upper trolley and other parts from top to bottom, and then replace the old lower trolley with a new lower trolley, and finally install the upper trolley, guide rod, cross frame, electrical room, electrical room cable, driver's cab and rake hook in the reverse order of dismantling. Instead, the upper trolley is directly lifted together with the accessories to a height at which the old lower trolley can be removed, and then the old lower trolley is replaced with a new lower trolley. After passing the test, the upper trolley is lowered back onto the new lower trolley together with the accessories to complete the replacement of the lower trolley. Not only is the replacement workload small, but the replacement time of the lower trolley can also be greatly shortened, and the replacement work can be completed within 7 to 8 days of the annual maintenance of 1# square billet.

[0020] Accordingly, in the specific replacement process, further combined with the structural characteristics of the rake crane and the use environment, in order to maximize the safety of construction and improve the replacement quality and replacement speed as much as possible, when removing the old lower trolley 1, the present application first cuts the old lower trolley 1 into two parts along the assembly seam, and then drags the two halves of the old lower trolley 1 away from the position of the upper trolley 3 along the track 4 on the main beam 2, and finally uses the car crane to lift the two halves of the old lower trolley 1 to the workshop floor to complete the removal of the old lower trolley 1. Before using the jacking system to lift the upper trolley 3 away from the old lower trolley 1, at least the guide rod and rake hook on the upper trolley 3 are first lowered to the workshop floor through the steel rope of the upper trolley itself to reduce the total weight of the jacking, so that the jacking requirement can be achieved by using a jacking drive assembly with a smaller rated jacking force, and then the jacking system is used to lift the upper trolley 3 away from the old lower trolley 1. Before hoisting the new lower trolley 1 onto the track 4 of the main beam 2, the wheel assembly and transmission device on the old lower trolley 1 are first transferred and installed on the new lower trolley 1 and tested to be qualified before hoisting. When hoisting the new lower trolley 1, the new lower trolley 1 that has passed the test is split into two parts along the assembly seam to reduce the rated lifting force of the truck crane used and facilitate hoisting. The truck crane is then used to hoist the two halves of the new lower trolley 1 onto the track 4 of the main beam 2. Finally, the two halves of the new lower trolley 1 are connected as a whole using a connecting plate and high-strength bolts to complete the replacement of the new lower trolley 1.

[0021] Furthermore, as an important component of the improvement of this application, in order to achieve effective and safe jacking of the upper trolley, this application first makes a jacking system before using the jacking system to jack the upper trolley 3 away from the old lower trolley 1. The jacking system at least includes a supporting top frame and a jacking drive assembly; during the jacking process of the upper trolley 3, the jacking drive assembly is connected between the supporting top frame and the main beam 2, and the upper trolley 3 is fixed on the supporting top frame. More specifically, the supporting top frame of the present application comprises at least a rectangular supporting frame consisting of two supporting long cross beams 5 and two connecting short cross beams 6, and the jacking drive assembly is connected between the four corners of the rectangular supporting frame and the main beam 2 along the length direction of the two supporting long cross beams 5; the jacking drive assembly of the present application comprises four hydraulic jacks 7 with a lifting force of not less than 80t, and each hydraulic jack 7 is independently connected between the four ends of the two supporting long cross beams 5 and the main beam 2; the supporting top frame of the present application also comprises two sets of dispersing steel frames and four short-connected heightening columns 9, and the four hydraulic jacks 7 are respectively connected Four short-circuited heightening columns 9 are connected to the corresponding positions of the main beam 2 with the cooperation of two groups of force-dissipating steel frames; each group of force-dissipating steel frames in the present application includes a force-dissipating steel plate 8 and a group of double I-beam force-dissipating beams 10 welded from two I-beams, the force-dissipating steel plate 8 is padded at the bottom of the double I-beam force-dissipating beam 10, and the short-circuited heightening columns 9 are connected to the corresponding positions of the double I-beam force-dissipating beam 10; the upper trolley 3 is lifted from the old lower trolley 1 to a height of not less than 200 mm by the hydraulic jack 7 with the cooperation of the short-circuited heightening columns 9 and the force-dissipating steel frames, and is fastened to the top 11 through a fixed support after being lifted into place.

[0022] The technical solution of this application is further described below through specific embodiments: 1) The lower trolley consists of two parts, connected by high-strength bolts; 2) The upper trolley is seated on the lower trolley and rotates along the circular track of the lower trolley. Therefore, the upper trolley can be lifted up by a hydraulic press to achieve the purpose of separating from the lower trolley; 3) The 30mm steel plate and double I-beam 32# are laid to evenly distribute the force of the hydraulic press and transmit it to the main beam. The long crossbeam is used to lift the upper trolley. As the hydraulic press rises, the upper trolley is lifted and separated from the lower trolley. 4) The old lower trolley can be cut into two halves using gas welding and dragged out along the lower track; 5) Similarly, the new lower trolley is dragged in along the track and assembled with connecting plates and high-strength bolts to form a whole; 6) The hydraulic press falls back, driving the upper trolley to fall back onto the circular track of the lower trolley, completing the replacement of the lower trolley.

[0023] Example 1 The upper trolley and its connected equipment are lifted up to separate the upper trolley from the lower trolley, thereby achieving the purpose of replacing the lower trolley.

[0024] 1) Pre-install the lower trolley body on the ground in advance, and make the upper trolley lifting frame after confirming that it is correct; 2) Lower the guide rods and rake hooks on the upper trolley to the ground, reducing the lifting capacity from 54 tons to 40.1 tons. Install the jacking frame, start four 100-ton hydraulic presses, and use the jacking frame to lift the upper trolley, electrical room, and driver's cab 200 mm away from the lower trolley. 3) Cut the old lower trolley into two pieces, drag them out along both sides of the trolley track, and lift them away with a crane; 4) Remove the wheel assembly and transmission device of the old lower trolley and install them on the new lower trolley body. The new lower trolley is dragged into the installation position along both sides of the trolley track; 5) Install the lower trolley connecting plate, tighten the high-strength bolts, and complete the positioning and assembly of the trolley body; 6) Lower the four 100t hydraulic presses, place the upper trolley back on the circular track of the lower trolley, remove the jacking frame, and resume the removal of other components to complete the lower trolley replacement task.

Claims

1. A construction method for replacing the lower trolley of a rake crane, comprising a rake crane bridge arranged on a workshop beam column, a lower trolley (1) arranged on a main beam (2) of the rake crane bridge so as to be reciprocatingly movable in a longitudinal direction, and an upper trolley (3) arranged on the lower trolley (1) so as to be reciprocatingly movable in a circumferential direction, characterized in that: The construction method comprises the following steps: firstly lifting the upper trolley away from the old lower trolley (1) by a jacking system, then removing the old lower trolley (1), then installing the new lower trolley (1) to be replaced on the main beam (2) of the rake crane bridge, and finally lowering the upper trolley (3) back onto the new lower trolley (1) by a jacking system to complete the replacement of the rake crane lower trolley.

2. The construction method for replacing the lower trolley of a rake crane according to claim 1, characterized in that: When dismantling the old lower trolley (1), first cut the old lower trolley (1) into two parts along the assembly seam, and then drag the two halves of the old lower trolley (1) away from the position of the upper trolley (3) along the track (4) on the main beam (2), and finally hoist the two halves of the old lower trolley (1) to the workshop floor by a car crane to complete the dismantling of the old lower trolley (1).

3. The construction method for replacing the lower trolley of a rake crane according to claim 1 or 2, characterized in that: Before the upper trolley (3) is lifted off the old lower trolley (1) by the jacking system, at least the guide rod and the rake hook on the upper trolley (3) are lowered to the workshop floor through the steel rope of the upper trolley itself, and then the upper trolley (3) is lifted off the old lower trolley (1) by the jacking system.

4. The construction method for replacing the lower trolley of a rake crane according to claim 3, characterized in that: Before the new lower trolley (1) is hoisted onto the track (4) of the main beam (2), the wheel set and transmission device on the old lower trolley (1) are transferred and installed on the new lower trolley (1) and tested and then hoisted.

5. The construction method for replacing the lower trolley of a rake crane according to claim 4, characterized in that: When hoisting the new lower trolley (1), the new lower trolley (1) that has passed the test is split into two parts along the assembly seam, and then the two halves of the new lower trolley (1) are hoisted to the track (4) of the main beam (2) using a car crane. Finally, the two halves of the new lower trolley (1) are connected as a whole using a connecting plate and high-strength bolts to complete the replacement of the new lower trolley (1).

6. The construction method for replacing the lower trolley of a rake crane according to claim 5, characterized in that: Before using the jacking system to jack the upper trolley (3) away from the old lower trolley (1), a jacking system is first manufactured, wherein the jacking system at least includes a supporting top frame and a jacking drive assembly; during the jacking process of the upper trolley (3), the jacking drive assembly is connected between the supporting top frame and the main beam (2), and the upper trolley (3) is fixed on the supporting top frame.

7. The construction method for replacing the lower trolley of a rake crane according to claim 6, characterized in that: The supporting top frame comprises at least a rectangular supporting frame composed of two supporting long cross beams (5) and two connecting short cross beams (6), and the lifting drive assembly is connected between the four corners of the rectangular supporting frame and the main beam (2) along the length direction of the two supporting long cross beams (5).

8. The construction method for replacing the lower trolley of a rake crane according to claim 7, characterized in that: The lifting drive assembly includes four hydraulic jacks (7) with a lifting force of not less than 80t, and each hydraulic jack (7) is independently connected between the four ends of the two supporting long cross beams (5) and the main beam (2).

9. The construction method for replacing the lower trolley of a rake crane according to claim 8, characterized in that: The supporting top frame also includes two groups of dispersing force steel frames and four short-circuited heightening columns (9). The four hydraulic jacks (7) are respectively connected to the corresponding positions of the main beam (2) through the four short-circuited heightening columns (9) in cooperation with the two groups of dispersing force steel frames.

10. The construction method for replacing the lower trolley of a rake crane according to claim 9, characterized in that: Each group of force-dispersing steel frames comprises a force-dispersing steel plate (8) and a group of double I-steel force-dispersing beams (10) welded from two I-steels. The force-dispersing steel plate (8) is cushioned at the bottom of the double I-steel force-dispersing beams (10), and the short-circuit heightening column (9) is seated at the corresponding position of the double I-steel force-dispersing beams (10). The upper trolley (3) is lifted from the old lower trolley (1) to a height of not less than 200 mm by the hydraulic jack (7) in cooperation with the short-circuit heightening column (9) and the force-dispersing steel frame, and is fastened by the fixed support (11) after being lifted into place.

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