Steel strand bundle threading device and steel strand bundle threading method for large-span prestressed concrete cast-in-place continuous box girder

Abstract

The invention relates to bridge construction, in particular to a large-span prestressed concrete cast-in-place continuous box girder steel strand threading device and a steel strand threading method; the device comprises a steel strand threading machine, a scaffolding pipe, a sliding rod, a heavy-duty drill chuck, a power transmission rod, a helical gear reducer, a three-phase asynchronous motor, and a mobile trolley, wherein one end of the scaffolding pipe is connected to a box girder threading hole, and the other end is connected to a wire outlet of the steel strand threading machine, the sliding rod is arranged at a steel strand bending position, the heavy-duty drill chuck is connected to one end of the power transmission rod, and the other end of the power transmission rod is connected to a helical gear reducer, the gear reducer is connected to the three-phase asynchronous motor, and the gear reducer is installed on the mobile trolley; by reasonably utilizing the combination of the threading machine, the three-phase asynchronous motor and the construction method, the problem that long-distance and large-span steel strands cannot be normally threaded is effectively solved, and the steel strand threading operation is completed efficiently.

Description

Technical Field

[0001] The invention relates to bridge construction, in particular to a steel strand bundle threading device and a steel strand bundle threading method for a large-span prestressed concrete cast-in-place continuous box girder. Background Art

[0002] The traditional post-tensioning prestressed steel strand threading method includes manual single strand threading or bundle threading, and manual cooperation with threading machine equipment to thread single or multiple strands. The manual threading is carried out in the cast box girder channel, one strand at a time by manpower, which is time-consuming and labor-intensive, and is only suitable for cast-in-place beams with shorter channels or prefabricated beams made in processing plants. When manual cooperation with threading machine equipment to thread single or multiple strands, the initial steel strands in the channel occupy less volume capacity, making threading convenient and construction efficient, but it is only suitable for beams with a span of less than 100 meters and a small number of prestressed tendons in the channel. When encountering a cast-in-place continuous box girder with a span greater than 100 meters, when the steel strands are manually threaded, due to the arched linear design of the channel, the steel strands in the channel are S-shaped after the bridge is closed; and the steel strands are bundled in coils, and they present irregular curves during installation and laying out; when the strands are threaded to more than 2 / 3 of the circular cross-section of the channel, the steel strands in the channel are staggered and partially block the channel; when manual threading is performed with the help of a threading machine, when the strands are threaded to half of the channel cross-section under this condition, due to the increased friction in the channel, the threading machine's own power and the bite force between the transmission wheels cannot continue to thread the steel strands, which in severe cases will cause the steel strands to block the hole, cause the corrugated pipe to rupture, the threading machine to stop working normally, and burn out. Summary of the invention

[0003] The present invention aims to solve the above problems, thereby providing a steel strand threading device and a steel strand threading method for a large-span prestressed concrete cast-in-place continuous box girder.

[0004] The present invention solves the above-mentioned problem by adopting the following technical solution:

[0005] A large-span prestressed concrete cast-in-place continuous box girder steel strand threading device comprises a steel strand threading machine, a scaffolding tube, a sliding rod, a heavy-duty drill chuck, a power transmission rod, a helical gear reducer, a three-phase asynchronous motor, and a mobile trolley. One end of the scaffolding tube is connected to a box girder threading channel, and the other end is connected to a wire outlet of the steel strand threading machine. The sliding rod is arranged at a bending position of the steel strand. The heavy-duty drill chuck is connected to one end of the power transmission rod, and the other end of the power transmission rod is connected to the helical gear reducer. The gear reducer is connected to the three-phase asynchronous motor, and the gear reducer is installed on the mobile trolley.

[0006] Compared with the prior art, the present invention adopting the above technical solution has the following outstanding features:

[0007] ① By rationally utilizing the combination of the bundle threading machine and the three-phase asynchronous motor, the problem of long-distance and large-span steel strands being unable to be normally threaded is effectively solved, and the steel strand threading operation is completed efficiently;

[0008] ② It has the beneficial effects of fast construction speed, less auxiliary equipment, greatly less labor input, safe and stable personnel during the bundle threading operation, and the bundle threading quality is not easy to be damaged.

[0009] Preferably, a further technical solution of the present invention is:

[0010] The sliding rod comprises a fixed wheel, a fixed rod, a sliding rod and a blocking wheel. The fixed wheels are installed at both ends of the fixed rod. The sliding rod is sleeved on the fixed rod. The blocking wheels are installed at both ends of the sliding rod, so that the bending part of the steel strand can also move smoothly.

[0011] The head of the power transmission rod is provided with a thread connected with a heavy-duty drill chuck, and the tail is a socket-shaped rectangular groove connected with a latch of an outer shaft disk of a helical gear reducer, so that the helical gear reducer and the heavy-duty drill chuck are well connected.

[0012] The mobile cart is equipped with a switch controller to facilitate operation and control by the staff.

[0013] The rear legs of the mobile trolley are equipped with directional casters to control the moving direction of the mobile trolley.

[0014] The box girder is equipped with a snap-on channel steel to ensure that the steel strands will not deviate when rotating.

[0015] The present invention also relates to a method for threading steel strands in a large-span prestressed concrete cast-in-place continuous box girder. First, the steel strands in the channel are cut and processed according to the design size, the processed steel strands are placed on a sliding rod, and the steel strands are manually pushed into a steel strand threading machine with assistance. The steel strand threading machine is started, so that the insertion end of the steel strand passes through the steel strand threading machine, and the insertion end of the steel strand is put into a bullet-shaped protective cap; then the steel strand threading machine is continuously started, so that the steel strands are evenly threaded and run in the box girder channel; when it is encountered that the steel strands cannot be normally threaded, the steel strand threading machine is started. The dynamic steel strand bundle threading machine will withdraw part of the steel strands from the channel by 3-5 meters, and insert the tail end of the steel strand into the heavy-duty drill chuck to clamp and connect; after the heavy-duty drill chuck is assembled and connected with the assembled power transmission rod, helical gear reducer, three-phase asynchronous motor, and mobile trolley, start the steel strand bundle threading machine and the three-phase asynchronous motor. In the initial stage, the mobile trolley is pushed manually, and the personnel do not need to push the steel strands anymore after they enter normally; after the steel strand insertion end passes through the prestressed pipe and the exposed length meets the design requirements, turn off the bundle threading machine and the three-phase asynchronous motor, and remove the bundle threading device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the structure of a sliding rod according to an embodiment of the present invention;

[0017] Figure 2 It is a schematic diagram of the structure of a heavy-duty drill chuck and a power transmission rod according to an embodiment of the present invention;

[0018] Figure 3 This is a front view of the mobile trolley and the components on the trolley according to an embodiment of the present invention;

[0019] Figure 4 1 is a schematic top view of a mobile trolley and a component structure on the trolley according to an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram of steel strand bundle threading according to an embodiment of the present invention;

[0021] In the figure: a steel strand threading machine 1; a scaffolding tube 2; a sliding rod 3; a fixed wheel 3-1; a fixed rod 3-2; a sliding rod 3-3; a blocking wheel 3-4; a heavy-duty drill chuck 4; a power transmission rod 5; a helical gear reducer 6; a three-phase asynchronous motor 7; a mobile trolley 8; a directional castor 9; a switch controller 10; a steel strand 11; and a buckled channel steel 12. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with embodiments, the purpose of which is only to better understand the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0023] See also Figure 1-Figure 5 A steel strand threading device for a large-span prestressed concrete cast-in-place continuous box girder includes a steel strand threading machine 1, a scaffolding tube 2, a sliding rod 3, a heavy-duty drill chuck 4, a power transmission rod 5, a helical gear reducer 6, a three-phase asynchronous motor 7, and a moving trolley 8. One end of the scaffolding tube 2 is connected to the box girder threading channel, and the other end is connected to the outlet of the steel strand threading machine 1. The sliding rod 3 is arranged at the bending position of the steel strand 11. The heavy-duty drill chuck 4 is connected to one end of the power transmission rod 5, and the other end of the power transmission rod 5 is connected to the helical gear reducer 6. The helical gear reducer 6 is connected to the three-phase asynchronous motor 7, and the helical gear reducer 6 is installed on the moving trolley 8.

[0024] First, the sliding rod 3 is processed. The sliding rod 3 is composed of a fixed wheel 3-1, a fixed rod 3-2 and a sliding rod 3-3. The sliding rod 3-3 is provided with a stop wheel 3-4 to prevent the steel strand from popping out. The diameter of the fixed wheel 3-1 is 100mm, the diameter of the fixed rod 3-2 is 20mm, and the length is 500mm. The diameter of the sliding rod 3-3 is 40mm, and the length is 400mm. The diameter of the stop wheel 3-4 is 60mm. Two fixed wheels 3-1 and stop wheels 3-4 are processed and manufactured for each set of sliding rods 3. There is one rod 3-2 and one sliding rod 3-3, fixed wheels 3-1 are installed at both ends of the fixed rod 3-2, the sliding rod 3-3 is sleeved on the fixed rod 3-2, the sliding rod 3-3 can slide left and right while rolling on the fixed rod 3-2, the blocking wheel 3-4 is welded on the sliding rod 3-3, and the blocking wheel 3-4 is 50mm away from the outer edge of the sliding rod 3-3. The manufactured sliding rod 3 is installed one on the top of the box beam and one on the waist of the hanging basket. The two sets of sliding rods 3 are on the same conveying surface.

[0025] The power transmission rod 5 is made of alloy and is forged on a lathe. The upper and lower rod diameters are 80 mm and the rod length is 200 mm. The head is provided with a threaded sleeve for tightening connection with a heavy-duty drill chuck 4. The tail is a socket-shaped rectangular groove for tightening with the pin of the outer shaft disk of the helical gear reducer 6 to ensure that it does not loosen.

[0026] The parameters of the helical gear reducer 6 are speed ratio 1:40 and input speed 1500rpm. The parameters of the three-phase asynchronous motor 7 are rated speed 1400r / min, rated voltage 380V, and rated power 1.5kw. The helical gear reducer 6 is matched with the three-phase asynchronous motor 7; a 500mm long 5# channel steel is welded on the bottom plate of the mobile trolley 8, and a mounting hole is set every 100mm. The assembled helical gear reducer 6 is threadedly connected to the bottom plate channel steel of the mobile trolley 8. Two 8-inch directional casters 9 are installed on the rear leg tube of the mobile trolley 8. The bottom of the leg tube is provided with a mounting hole, and the directional casters 9 are threadedly connected to the leg tube. The mobile trolley 8 can walk on the top of the cast-in-place box girder, and can also be installed on the top surface of the cast-in-place box girder adjacent to the span.

[0027] The steel strands 11 in the channel are cut and processed according to the designed dimensions, the processed steel strands 11 are placed on the sliding rod 3, and the steel strands 11 are pushed into the steel strand bundle threading machine 1 with manual assistance, and the steel strand bundle threading machine 1 is started to make the insertion end of the steel strand 11 pass through the steel strand bundle threading machine 1. The scaffolding tube 2 is made of steel pipe, with a wall thickness of 3mm and a length of 1m. One end is inserted into the corrugated pipe channel in the beam body, and the other end is firmly tied to the outlet of the steel strand bundle threading machine 1 with 6# iron wire to make it work in the same horizontal line. The insertion end of the steel strand 11 is put into a bullet-shaped protective cap; the steel strand bundle threading machine 1 is continuously started to make the steel strand 11 evenly pass through the bundle in the channel.

[0028] When the steel strand 11 cannot be bundled normally, start the steel strand bundling machine 1 to withdraw part of the steel strand 11 from the channel by 3-5 meters; the tail end of the steel strand 11 is clamped and connected with the heavy-duty drill chuck 4, and the heavy-duty drill chuck 4 is assembled and connected with the assembled power transmission rod 5, helical gear reducer 6, three-phase asynchronous motor 7, and mobile trolley 8. Then, start the power switch of the steel strand bundling machine 1 and the three-phase asynchronous motor 7, and the heavy-duty drill chuck 4 is driven by the three-phase asynchronous motor 7 in conjunction with the helical gear reducer 6, and the steel strand 11 rotates accordingly. At the same time, the steel strand bundling machine 1 conveys the steel strand 11 forward. In the initial stage, the mobile trolley is pushed with manual assistance. After the steel strand 11 enters normally, the personnel do not need to push it anymore.

[0029] The present invention uses a 6-wheel steel strand threading machine 1. If the span is less than 100m, a 4-wheel, 6.5KW power threading machine can also be used for threading. The upper steel strand 11 slides on the cast box girder and is installed with a 5# buckle-covered channel steel 12 to ensure that the steel strand 11 will not deflect when rotating and always travel on the same working surface; three sections of 10-meter buckle-covered channel steel 12 can be installed for every 100-meter steel strand 11 installed, and when the rotating heavy-duty drill chuck 4 is close to the buckle-covered channel steel 12, the buckle-covered channel steel 12 can be moved to the next section and reused, and the lower steel strand 11 is fixed The sliding rod 3 fixed above the hanging basket and at the waist position is transmitted to the wire inlet of the bundle threading machine. The channel and the wire outlet of the steel strand bundle threading machine 1 are connected with a scaffolding pipe 2 to ensure that the steel strand 11 slides evenly into the channel. The steel strand bundle threading machine 1 and the rotating heavy-duty drill chuck 4 fixed on the mobile trolley 8 jointly generate power to bundle the steel strand 11 into the channel, and there is no need for personnel to push the mobile trolley 8 when the machine is running. The force on the steel strand 11 is the forward driving force generated by the driving wheel group of the steel strand bundle threading machine 1 and the additional rotational force of the rotating heavy-duty drill chuck 4, and the steel strand 11 is bundled and moved between the gaps in the channel.

[0030] The purpose of the embodiment of the present invention is to ensure that long-distance and large-span steel strands 11 can be evenly bundled in the channel, and to prevent the steel strands 11 from blocking the hole and causing the corrugated tube to rupture; during construction, the steel strand bundle threading machine 1 and the three-phase asynchronous motor 7 are reasonably used in conjunction with the reducer to drive the heavy drill chuck 4, so as to achieve the beneficial effects of reducing labor input, reducing the work intensity of construction personnel, shortening the construction period, and saving engineering costs.

[0031] The above description is only a preferred feasible embodiment of the present invention, and does not limit the scope of rights of the present invention. All equivalent changes made using the contents of the present specification and its drawings are included in the scope of rights of the present invention.

Claims

1. A method for threading a steel strand of a large-span prestressed concrete cast-in-place continuous box girder, based on a steel strand threading device for a large-span prestressed concrete cast-in-place continuous box girder, the device comprising a steel strand threading machine (1), a scaffolding tube (2), a sliding rod (3), a heavy-duty drill chuck (4), a power transmission rod (5), a helical gear reducer (6), a three-phase asynchronous motor (7), and a mobile trolley (8), wherein one end of the scaffolding tube (2) is connected to a box girder threading hole, and the other end is connected to an outlet of the steel strand threading machine (1), the sliding rod (3) is arranged at a bending position of the steel strand (11), the heavy-duty drill chuck (4) is connected to one end of the power transmission rod (5), and the other end of the power transmission rod (5) is connected to the helical gear reducer (6), the helical gear reducer (6) is connected to the three-phase asynchronous motor (7), and the helical gear reducer (6) is installed on the mobile trolley (8); The sliding rod (3) comprises a fixed wheel (3-1), a fixed rod (3-2), a sliding rod (3-3) and a blocking wheel (3-4); the fixed wheels (3-1) are mounted at both ends of the fixed rod (3-2); the sliding rod (3-3) is sleeved on the fixed rod (3-2); and the blocking wheels (3-4) are mounted at both ends of the sliding rod (3-3); The head of the power transmission rod (5) is provided with a threaded part for connection with the heavy-duty drill chuck (4), and the tail is provided with a socket-shaped rectangular groove for connection with the outer shaft disk pin of the helical gear reducer (6); It is characterized in that The steel strand threading method is as follows: First, the steel strands (11) in the hole are cut and processed according to the design size, the processed steel strands (11) are placed on the sliding rod (3), and the steel strands (11) are manually assisted to enter the steel strand bundle threading machine (1), and the steel strand bundle threading machine (1) is started, so that the insertion end of the steel strand (11) passes through the steel strand bundle threading machine (1), and the insertion end of the steel strand (11) is put into a bullet-shaped protective cap; then the steel strand bundle threading machine (1) is continuously started, so that the steel strands (11) are evenly bundled and run in the box girder hole; when it is encountered that the steel strands (11) cannot be bundled normally, the steel strand bundle threading machine (1) is started to withdraw part of the steel strands (11) 3-5 meters out of the hole, insert the tail end of the steel strand (11) into the heavy-duty drill chuck (4) for clamping connection; after the heavy-duty drill chuck (4) is assembled and connected with the assembled power transmission rod (5), the helical gear reducer (6), the three-phase asynchronous motor (7), and the mobile trolley (8), start the steel strand bundle threading machine (1) and the three-phase asynchronous motor (7). Initially, the mobile trolley (8) is pushed with manual assistance. After the steel strand (11) enters normally, the personnel do not need to push it anymore; after the inserted end of the steel strand (11) passes through the prestressed pipe and the exposed length meets the design requirements, turn off the steel strand bundle threading machine (1) and the three-phase asynchronous motor (7), and remove the bundle threading device.

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