Cast-in-place box girder construction device

Abstract

The invention discloses a cast-in-place box girder construction device which comprises a plurality of supporting columns, two unloading block assemblies and a truss supporting mechanism, the supporting columns are arranged in a front row and a rear row, every two adjacent supporting columns in the same row are fixedly connected together through a connecting frame, and the unloading block assemblies are arranged on the supporting columns in the front row and the rear row correspondingly. The truss supporting mechanism is arranged on the unloading block assembly, the unloading block assembly comprises a plurality of unloading blocks and a pulling mechanism for driving the unloading blocks to be adjusted in a lifting mode, each unloading block comprises a lower base, an upper base, a sliding sleeve, a hollow supporting body, a fixed pulley block, a movable pulley block and a steel wire rope, the hollow supporting body is arranged on the lower base, and the lower base is provided with the sliding sleeve. The hollow supporting body is sleeved with a sliding sleeve which is in sliding fit with the hollow supporting body, an upper base is arranged at the upper end of the sliding sleeve, a fixed pulley block is arranged in the upper end of the hollow supporting body, a movable pulley block is arranged at the lower end of the sliding sleeve, and compared with the prior art, use can be convenient, the working efficiency is improved, adjustment is labor-saving, and the automation degree is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, in particular to the technical field of a cast-in-situ box girder construction device. Background Art

[0002] During the construction of cast-in-place box girders, a support platform is required to build the box girder formwork. The support platform mainly includes trusses for supporting the box girder and unloading blocks for supporting the trusses.

[0003] During the bridge construction process, the dismantling of the truss after installation is also an important component, such as: the dismantling device for bridge trusses with application (patent) number: CN202122216404.2, which includes a main beam fixed to the cast-in-place beam, and the number of the main beams is two. The two main beams are respectively provided with a lifting device for lifting the truss, and the lifting device is slidingly arranged along the main beam. The main beam is located above the cast-in-place beam, and the stability between the main beam and the cast-in-place beam is improved by the fixing rod. The horizontal movement of the truss is achieved by sliding the lifting device along the main beam, and the vertical movement of the truss is achieved by the lifting device, and finally the dismantling of the truss is completed. When the truss in the lifting position is lifted out by the lifting device, the next truss needs to be moved to the lifting position. In the prior art, the truss is generally pulled by the cooperation of a hydraulic cylinder, a wire rope and a hook. However, each operation requires manual removal and hanging of the hook, which wastes manpower and has a low degree of automation.

[0004] The main functions of the unloading block in bridge construction include elevation adjustment and truss dismantling. During the construction process, the truss is a load-bearing structure that must be used for pouring concrete. In order to ensure the quality and strength of the concrete, the truss elevation needs to be adjusted. The assembled unloading block can easily adjust the elevation, improve construction efficiency, and ensure project quality. In addition, after the main concrete structure is poured, the truss needs to be dismantled. The assembled unloading block has the advantages of easy disassembly and assembly and low cost, which can effectively reduce the dismantling cost and improve construction efficiency.

[0005] The application (patent) number is: CN202321424337.6. A temporary support unloading block that can be quickly lowered includes an upper support, a lower support, a left support and a right support. The left support and the right support are respectively provided on both sides of the upper surface of the lower support. The upper surfaces of the left support and the right support are jointly overlapped with the upper support. The interiors of the left support and the right support are jointly penetrated with a bidirectional screw. Through the arrangement of the upper support, the lower support, the left support, the right support and the bidirectional screw, by penetrating the bidirectional screw on the left support and the right support, By turning the hexagonal bolt at one end of the two-way screw, the left support and the right support can be moved synchronously to realize the rise and fall of the entire unloading block, thereby lowering the upper structure. This is quick and convenient, and avoids uneven supporting forces of the left and right supports on the upper support, ensuring the levelness of the upper support, thereby ensuring a safe and stable lowering process. Since each load-bearing beam of the entire formwork system needs to be supported by multiple unloading blocks, however, when performing the lifting and lowering adjustment of the unloading blocks, it is necessary to manually adjust the unloading blocks one by one, which is inconvenient to use and reduces work efficiency. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems in the prior art and to provide a cast-in-situ box girder construction device that is easy to use, improves work efficiency, saves effort in adjustment, and improves the degree of automation.

[0007] The lifting mechanism is a kind of in-situ sliding frame, ... A steel wire rope is wound around the wheel assembly, one end of the steel wire rope is fixedly connected to the wheel frame of the fixed pulley assembly, and the other end is connected to the pulling mechanism. The truss support mechanism includes two guide rail beams, a plurality of truss units, two driving units and a plurality of walking trolleys. Both ends of the truss unit are respectively arranged on the two guide rail beams through a plurality of walking trolleys, and two adjacent truss units are detachably connected. The same ends of the two guide rail beams are provided with a driving unit for driving the truss unit to move. The driving unit includes a hydraulic cylinder II, a slide and a tongue. The driving end of the hydraulic cylinder II is provided with a slide that slides in the cavity of the guide rail beam, and the slide is elastically provided with a tongue, which is inserted into the long slot hole of the guide rail beam. A hanging ear that cooperates with the tongue is provided on the walking trolley at the rear bottom of each truss unit, and the upper end of the tongue is provided with an inclined guide surface.

[0008] Preferably, the cross-section of the hollow support body is rectangular, the pulley of the movable pulley group is located in the hollow support body, and an avoidance opening is provided on the side wall of the hollow support body corresponding to the pulley shaft of the movable pulley group. A guide wheel seat is provided on the upper rear side of the hollow support body, and a guide wheel seat is provided on the guide wheel seat, one end of which extends into the hollow support body, and the guide wheel is used to guide the wire rope.

[0009] Preferably, a long slot is provided on the rear side of the sliding sleeve to avoid the guide wheel seat.

[0010] Preferably, the pulling mechanism includes a driving mechanism and several connecting mechanisms arranged on the driving mechanism, the connecting mechanism includes a connecting body, a screw body is passed through the connecting body, the front end of the screw body is fixedly connected to the corresponding end of the corresponding steel wire rope, and the screw body is provided with an adjusting nut located at the rear end of the connecting body.

[0011] Preferably, the driving mechanism includes a fixed seat, a movable seat, a hydraulic cylinder I and two pull rods, a pull rod is slidably provided on the fixed seat, a movable seat is provided at the rear end of the pull rod, a hydraulic cylinder I is provided between the fixed seat and the movable seat, and a connector is provided on the pull rod.

[0012] Preferably, the unloading block and the pulling mechanism are arranged on a mounting seat, and the mounting seat is provided with a bracket supported on the pull rod.

[0013] Preferably, the movable seat is provided with tightening bolts respectively located on both sides of the hydraulic cylinder 1, and the tightening bolts are provided with fastening nuts on both sides of the movable seat.

[0014] Preferably, a sliding cavity is provided in the sliding seat, a telescopic spring and a slider located at the upper end of the telescopic spring are provided in the sliding cavity, a rectangular slot is provided at the upper end of the slider, and the lower end of the tongue passes through the long slot hole and the upper end of the sliding seat in sequence and is inserted into the rectangular slot matching it.

[0015] Preferably, a hanging ring is provided on one side of the truss unit and a hook is provided on the other side, and two adjacent truss units are detachably connected through the cooperation of the hanging ring and the hook.

[0016] The beneficial effects of the present invention are as follows: the present invention drives the slide to move backward by retracting the hydraulic cylinder II, and the slide drives the connected truss units to move backward to the lifting position through the cooperation of the latch and the hanging ear, and then the truss unit connected to the driving unit is lifted out by the sling, and then the hydraulic cylinder II is started to extend to drive the slide to move forward, and the slide drives the latch to move forward. When the latch enters under the hanging ear, the setting of the guide slope will force the latch to move downward and compress the telescopic spring through the slider. When the latch enters under the hanging hole of the hanging ear, the telescopic spring Under the action of , the slider drives the tongue to move upward and insert it into the hanging ear, and then the hydraulic cylinder II retracts and works, and the above operation is repeated, so that the truss units enter the lifting position one by one, which can save manpower and has a high degree of automation; the pulling mechanism pulls the wire rope and drives the sliding sleeve to move up and down through the cooperation of the fixed pulley group and the movable pulley group, and the sliding sleeve drives the upper base to move, so that multiple unloading blocks can be adjusted at the same time. In addition, the cooperation of the fixed pulley group, the movable pulley group and the wire rope can effectively reduce the pulling force of the pulling mechanism, which can be easy to use, improve work efficiency and save effort in adjustment.

[0017] The features and advantages of the present invention will be described in detail through embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a cast-in-situ box girder construction device of the present invention; Figure 2 yes Figure 1 A magnified view of middle A; Figure 3 It is a partial side view of a cast-in-situ box girder construction device of the present invention; Figure 4 It is a top view of the pulling mechanism; Figure 5 It is a structural diagram of the unloading block; Figure 6 is a side view of the truss support mechanism; Figure 7 yes Figure 6 Magnified view of B.

[0019] In the figure: 1-support column, 2-unloading block assembly, 3-truss support mechanism, 4-connecting frame, 21-unloading block, 22-pulling mechanism, 23-mounting seat, 24-bracket, 211-lower base, 212-upper base, 213-sliding sleeve, 214-hollow support body, 215-fixed pulley group, 216-movable pulley group, 217-wire rope, 218-avoidance, 219-guide wheel seat, 211 0-guide wheel, 2111-long slot, 221-drive mechanism, 222-connection mechanism, 2211-fixed seat, 2212-movable seat, 2213-hydraulic cylinder I, 2214-pull rod, 2221-connector, 2222-screw body, 2223-adjusting nut, 31-guide beam, 32-truss unit, 33-drive unit, 34-traveling trolley, 35-hanging ring, 36-hook , 37- hanging ear, 311- cavity, 312- long slot, 321- truss body, 322- connecting frame, 331- hydraulic cylinder II, 332- slide seat, 333- tongue, 334- guide surface, 335- sliding cavity, 336- telescopic spring, 337- slider, 338- rectangular slot, 3211- Bailey plate body, 3212- rear connector, 3213- front connector, 32111- slot Steel body, 32121-connecting shaft, 32122-slot, 32131-connecting sleeve, 32132-elastic clip, 32133-pulling mechanism, 321321-pin, 321322-support, 321323-blocking protrusion, 321324-spring, 321325-guide slope, 321331-pull rope, 321332-pull ring, 321333-guide hook. DETAILED DESCRIPTION

[0020] Example 1 See Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 and Figure 7The present invention provides a cast-in-situ box girder construction device, comprising a plurality of support columns 1, two unloading block assemblies 2 and a truss support mechanism 3. The support columns 1 are arranged in two rows, front and back, and two adjacent support columns 1 in the same row are fixedly connected together by a connecting frame 4. The support columns 1 in the front and back rows are both provided with an unloading block assembly 2. The truss support mechanism 3 is provided on the unloading block assembly 2. The unloading block assembly 2 includes a plurality of unloading blocks 21 and a pulling mechanism 22 for driving the unloading blocks 21 to rise and fall. The unloading block includes a lower base 211 and an upper base 2 12, a sliding sleeve 213, a hollow support body 214, a fixed pulley group 215, a movable pulley group 216 and a steel wire rope 217. The lower base 211 is provided with a hollow support body 214, and a sliding sleeve 213 is provided on the hollow support body 214. The upper end of the sliding sleeve 213 is provided with an upper base 212, and a fixed pulley group 215 is provided in the upper end of the hollow support body 214. The lower end of the sliding sleeve 213 is provided with a movable pulley group 216. The fixed pulley group 215 and the movable pulley group 216 are wound with a steel wire rope 217. 7. One end of the steel wire rope 217 is fixedly connected to the wheel frame of the fixed pulley group 215, and the other end is connected to the pulling mechanism 22. The truss support mechanism 3 includes two guide rail beams 31, a plurality of truss units 32, two drive units 33 and a plurality of walking trolleys 34. Both ends of the truss unit 32 are respectively provided on the two guide rail beams 31 through a plurality of walking trolleys 34. The two adjacent truss units 32 are detachably connected. The same end of the two guide rail beams 31 is provided with a drive unit 33 for driving the truss unit 32 to move. The driving unit 33 includes a hydraulic cylinder II331, a slide 332 and a tongue 333. The driving end of the hydraulic cylinder II331 is provided with a slide 332 that slides in the cavity 311 of the guide rail beam 31. The slide 332 is elastically provided with a tongue 333. The tongue 333 is passed through the long slot 312 of the guide rail beam 31. The walking trolley 34 at the rear bottom of each truss unit 32 is provided with a hanging ear 37 that cooperates with the tongue 333. The upper end of the tongue 333 is provided with an inclined introduction surface 334.

[0021] The cross-section of the hollow support body 214 is rectangular, and the pulley of the movable pulley group 216 is located in the hollow support body 214. The side wall of the hollow support body 214 corresponding to the pulley shaft of the movable pulley group 216 is provided with an avoidance opening 218, and the upper rear part of the hollow support body 214 is provided with a guide wheel seat 219. The guide wheel seat 219 is provided with a guide wheel 2110 with one end extending into the hollow support body 214, and the guide wheel 2110 is used to guide the wire rope 217.

[0022] The rear side of the sliding sleeve 213 is provided with a long slot 2111 for avoiding the guide wheel seat 219.

[0023] The pulling mechanism 22 includes a driving mechanism 221 and a plurality of connecting mechanisms 222 arranged on the driving mechanism 221. The connecting mechanism 222 includes a connecting body 2221, and a screw body 2222 is passed through the connecting body 2221. The front end of the screw body 2222 is fixedly connected to the corresponding end of the corresponding steel wire rope 217, and the screw body 2222 is provided with an adjusting nut 2223 located at the rear end of the connecting body 2221.

[0024] The driving mechanism 221 includes a fixed seat 2211, a movable seat 2212, a hydraulic cylinder I2213 and two pull rods 2214. The pull rod 2214 is slidably passed through the fixed seat 2211, and the rear end of the pull rod 2214 is provided with a movable seat 2212. A hydraulic cylinder I2213 is provided between the fixed seat 2211 and the movable seat 2212, and a connecting body 2221 is provided on the pull rod 2214.

[0025] The unloading block 21 and the pulling mechanism 22 are arranged on a mounting seat 23 , and a bracket 24 supported on a pull rod 2214 is provided on the mounting seat 23 .

[0026] The movable seat 2212 is provided with tightening bolts 2215 located on both sides of the hydraulic cylinder I2213, and the tightening bolts 2215 are provided with fastening nuts 2216 on both sides of the movable seat 2212.

[0027] A sliding cavity 335 is provided in the sliding seat 332, and a telescopic spring 336 and a slider 337 located at the upper end of the telescopic spring 336 are provided in the sliding cavity 335. A rectangular slot 338 is provided at the upper end of the slider 337, and the lower end of the latch 333 passes through the long slot 312 and the upper end of the sliding seat 332 in sequence and is inserted into the rectangular slot 338 matching it.

[0028] The truss unit 32 is provided with a hanging ring 35 on one side and a hook 36 on the other side. Two adjacent truss units 32 are detachably connected through the cooperation of the hanging ring 35 and the hook 36 .

[0029] Example 2 See Figure 1 、 Figure 2 and Figure 6 The truss unit 32 includes two truss bodies 321 , which are fixedly connected together by a plurality of connecting frames 322 , and a walking trolley 34 is provided at both ends of the truss body 321 .

[0030] The truss body 321 includes a plurality of Bailey sheet bodies 3211, and the front and rear ends of the Bailey sheet bodies 3211 are respectively provided with a front connecting piece 3213 and a rear connecting piece 3212. The two adjacent Bailey sheet bodies 3211 are detachably fixedly connected by the rear connecting piece 3212 and the front connecting piece 3213. The rear connecting piece 3212 includes two upper and lower connecting shafts 32121, and the front connecting piece 3213 includes two connecting sleeves 32131, two elastic clips 32132 and a pulling mechanism 32133. The connecting sleeve 32131 corresponds to and cooperates with the connecting shaft 32121 one by one. The connecting shaft 32121 is inserted into the corresponding connecting sleeve 32131 and is connected to the corresponding elastic clip 32132. The elastic clip 32132 includes an elastically set pin 321321. The connecting shaft 32121 is provided with a slot 32122 that cooperates with the pin 321321. The pulling mechanism 32133 is connected to the pin 321321 to drive the pin 321321 out of the slot 32122.

[0031] The elastic clip 32132 and the pulling mechanism 32133 are arranged in the corresponding channel steel body 32111 of the Bailey plate body 3211.

[0032] The elastic clamp 32132 also includes a support 321322, on which a latch 321321 is passed. A blocking protrusion 321323 is provided on the outer wall of the latch 321321 relative to the outer side of the support 321322, and a spring 321324 is sleeved on the latch 321321 between the blocking protrusion 321323 and the support 321322.

[0033] The insertion end of the latch 321321 is provided with a guide slope 321325 which is lower in the front and higher in the back.

[0034] The pulling mechanism 32133 includes a pull rope 321331 , a pull ring 321332 and two guide hooks 321333 . The pull rope 321331 is passed through the guide hooks 321333 , and a pull ring 321332 is provided on the pull rope 321331 between the two guide hooks 321333 .

[0035] Working process of the present invention: When the gantry crane 310 is in the working state, the gantry crane 310 is in the working state, and the gantry crane 310 is in the working state, so that the gantry crane 310 is in the working state, and the gantry crane 310 is in the working state, so that the gantry crane 310 is in the working state, and the gantry crane 310 is in the working state, so that the gantry crane 310 is in the working state, and the gantry crane 310 is in the working state,

[0036] When connecting the Bailey plate body 3211, firstly, the two connecting shafts 32121 correspond to the two connecting sleeves 32131 respectively, and then the connecting shaft 32121 is inserted into the connecting sleeve 32131. When the rear end of the connecting shaft 32121 passes through the bayonet 321321, the bayonet 321321 is forced to move away from the center of the connecting shaft 32121 due to the action of the guide inclined surface 321325. The bayonet 321321 compresses the spring 321324 through the blocking protrusion 321323. When the slot 32122 corresponds to the bayonet 321321, the bayonet 321321 is in the spring 321324. 21324 is inserted into the slot 32122; when the Bailey piece body 3211 is disassembled, pull the pull ring 321332 and pull the bayonet 321321 away from the center of the connecting shaft 32121 through the pull rope 321331. When the bayonet 321321 is disengaged from the slot 32122, the Bailey piece body 3211 can be disassembled. When the Bailey piece body is connected, the connecting shaft can be directly passed through the corresponding connecting sleeve. When disassembling, the bayonet pin is driven out of the slot by the pulling mechanism, and then the Bailey piece body can be disassembled, which can improve work efficiency and reduce manual workload.

[0037] During the operation of the unloading block assembly, the hydraulic cylinder I2213 is started to drive the movable seat 2212 to move backward. The movable seat 2212 drives the connecting body 2221 to move backward through the pull rod 2214. The connecting body 2221 pulls the wire rope 217 through the cooperation of the adjusting nut 2223 and the screw body 2222. The wire rope 217 drives the movable pulley group 216 to move upward. The movable pulley group 216 drives the upper base 212 to move upward through the sliding sleeve 213 for position adjustment. When the upper base 212 needs to be lowered for adjustment, the hydraulic cylinder I2213 is started to drive the movable seat 2212 to move forward.

[0038] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention falls within the protection scope of the present invention.

Claims

1. A cast-in-situ box girder construction device, characterized by: The invention comprises a plurality of support columns (1), two unloading block assemblies (2) and a truss support mechanism (3), wherein the support columns (1) are arranged in two rows, front and back, and two adjacent support columns (1) in the same row are fixedly connected together by a connecting frame (4), and the support columns (1) in the front and back rows are both provided with an unloading block assembly (2), and the truss support mechanism (3) is provided on the unloading block assembly (2), and the unloading block assembly (2) comprises a plurality of unloading blocks (21) and a pulling mechanism (22) for driving the unloading blocks (21) to rise and fall. The unloading blocks comprise a lower base (211), an upper base (212), a sliding sleeve (213), a hollow A support body (214), a fixed pulley group (215), a movable pulley group (216) and a wire rope (217); a hollow support body (214) is provided on the lower base (211); a sliding sleeve (213) is provided on the hollow support body (214); an upper base (212) is provided on the upper end of the sliding sleeve (213); a fixed pulley group (215) is provided in the upper end of the hollow support body (214); a movable pulley group (216) is provided at the lower end of the sliding sleeve (213); a wire rope (217) is wound around the fixed pulley group (215) and the movable pulley group (216); the wire rope One end of (217) is fixedly connected to the wheel frame of the fixed pulley group (215), and the other end is connected to the pulling mechanism (22). The truss support mechanism (3) includes two guide rail beams (31), a plurality of truss units (32), two drive units (33) and a plurality of walking trolleys (34). Both ends of the truss unit (32) are respectively arranged on the two guide rail beams (31) through a plurality of walking trolleys (34). Two adjacent truss units (32) are detachably connected. The same end of the two guide rail beams (31) is provided with a drive unit (33) for driving the truss unit (32) to move. The drive unit (33) ) includes a hydraulic cylinder II (331), a slide (332) and a tongue (333), wherein the driving end of the hydraulic cylinder II (331) is provided with a slide (332) which slides in a cavity (311) of the guide rail beam (31), and the slide (332) is elastically provided with a tongue (333), and the tongue (333) is passed through the long slot (312) of the guide rail beam (31), and a hanging ear (37) which matches the tongue (333) is provided on the traveling trolley (34) at the rear bottom of each truss unit (32), and the upper end of the tongue (333) is provided with an inclined guide surface (334).

2. A cast-in-situ box girder construction device according to claim 1, characterized in that: The cross section of the hollow support body (214) is rectangular. The pulley of the movable pulley group (216) is located in the hollow support body (214). A clearance opening (218) is provided on the side wall of the hollow support body (214) corresponding to the pulley shaft of the movable pulley group (216). A guide wheel seat (219) is provided on the upper rear side of the hollow support body (214). A guide wheel (2110) is provided on the guide wheel seat (219) with one end extending into the hollow support body (214). The guide wheel (2110) is used to guide the wire rope (217).

3. A cast-in-situ box girder construction device according to claim 2, characterized in that: A long notch (2111) for avoiding the guide wheel seat (219) is provided on the rear side of the sliding sleeve (213).

4. A cast-in-situ box girder construction device according to claim 1, characterized in that: The pulling mechanism (22) comprises a driving mechanism (221) and a plurality of connecting mechanisms (222) provided on the driving mechanism (221). The connecting mechanism (222) comprises a connecting body (2221). A screw body (2222) is provided on the connecting body (2221). The front end of the screw body (2222) is fixedly connected to the corresponding end of the corresponding steel wire rope (217). The screw body (2222) is provided with an adjusting nut (2223) located at the rear end of the connecting body (2221).

5. A cast-in-situ box girder construction device according to claim 4, characterized in that: The driving mechanism (221) comprises a fixed seat (2211), a movable seat (2212), a hydraulic cylinder I (2213) and two pull rods (2214); the pull rod (2214) is slidably passed through the fixed seat (2211); the movable seat (2212) is provided at the rear end of the pull rod (2214); the hydraulic cylinder I (2213) is provided between the fixed seat (2211) and the movable seat (2212); and the pull rod (2214) is provided with a connector (2221).

6. A cast-in-situ box girder construction device according to claim 1, characterized in that: The unloading block (21) and the pulling mechanism (22) are arranged on a mounting seat (23), and a bracket (24) supported on a pull rod (2214) is provided on the mounting seat (23).

7. A cast-in-situ box girder construction device according to claim 5, characterized in that: The movable seat (2212) is provided with tightening bolts (2215) respectively located on both sides of the hydraulic cylinder I (2213), and the tightening bolts (2215) are provided with fastening nuts (2216) on both sides of the movable seat (2212).

8. The cast-in-situ box girder construction device according to claim 1, characterized in that: A sliding cavity (335) is provided in the sliding seat (332), a telescopic spring (336) and a slider (337) located at the upper end of the telescopic spring (336) are provided in the sliding cavity (335), a rectangular slot (338) is provided at the upper end of the slider (337), and the lower end of the latch (333) passes through the long slot (312) and the upper end of the sliding seat (332) in sequence and is inserted into the rectangular slot (338) matched therewith.

9. A cast-in-situ box girder construction device according to any one of claims 1 to 8, characterized in that: One side of the truss unit (32) is provided with a hanging ring (35), and the other side is provided with a hook (36), and two adjacent truss units (32) are detachably connected through the cooperation of the hanging ring (35) and the hook (36).

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