CN212470323U

CN212470323U - Solebar point is firm frock

Info

Publication number: CN212470323U
Application number: CN202020399492.7U
Authority: CN
Inventors: 刘帅; 王瑞东
Original assignee: Shandong Shuipo Welding & Cutting Equipment Manufacture Co ltd
Current assignee: Shandong Shuibo Intelligent Equipment Co ltd
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2021-02-05
Anticipated expiration: 2030-03-25

Abstract

The utility model provides a solebar point solid frock, includes fixed station and elevating platform, all installs the lift gyro wheel system in fixed station and the elevating platform, one side of fixed station is equipped with the first location channel-section steel of arranging along its length, still is equipped with two at least longeron rear end compression positioning fixtures on fixed station, longeron rear end compression positioning fixtures includes first mounting panel, and first spout has all been seted up to the both sides position department of first mounting panel, and first spout fit in installs and to follow its gliding first slider, installs the first web location channel-section steel of detachable on the first slider of both sides, still installs first slide rail on first mounting panel, and first slide rail is located between two first spouts. The gooseneck beams of various different types are adapted by adjusting the heights of the compressing and positioning tool at the front end and the rear end and the height of the lifting workbench, and are positioned on the workbench, so that the point-fixing welding operation is facilitated.

Description

Solebar point is firm frock

Technical Field

The utility model relates to a vehicle processing technology field especially relates to an applicable solebar point solid frock in various gooseneck roof beams.

Background

The frame is the most important bearing part in the automobile, and the frame longitudinal beam is one of the key parts in the frame longitudinal beam, so the longitudinal beam plays an important bearing role on the automobile, and the side beam type frame, the middle beam type frame and the like of the automobile all contain the longitudinal beam, and the longitudinal beam is usually formed by stamping low alloy steel plates. When the preparation is such as the semitrailer longeron, need weld the steel sheet of difference to the gooseneck roof beam of preparation different grade type still needs to carry out the point solid frock to it before welding operation, because there is apparent structural difference between the gooseneck roof beam of different grade type, current longeron point solid frock can't be effectively to the tight location of clamp of all kinds of gooseneck roof beams, leads to the point solid operation inaccurate, and then influences subsequent welding quality, has brought the trouble of different degrees for the whole production process of solebar.

Disclosure of Invention

In order to solve the problem, an object of the utility model is to provide a solebar point solid frock, the gooseneck roof beam of the various different grade types of highly adaptation of the location frock of compressing tightly through adjustment front end, rear end and elevating platform ensures to fix a position it on the workstation to in the welding operation of point solid.

The utility model provides a technical scheme that its technical problem adopted is: the utility model relates to a frame longitudinal beam point fixing tool, which comprises a fixed workbench and a lifting workbench, wherein a lifting roller system is respectively arranged in the fixed workbench and the lifting workbench, one side of the fixed workbench is provided with a first positioning channel steel arranged along the length of the fixed workbench, at least two longitudinal beam rear end pressing and positioning tools are also arranged on the fixed workbench, the longitudinal beam rear end pressing and positioning tools comprise a first mounting plate, first chutes are respectively arranged at the two sides of the first mounting plate, a first slide block capable of sliding along the first chute is arranged in the first chute in a matching way, a detachable first web plate positioning channel steel is arranged on the first slide blocks at the two sides, a first slide rail is also arranged on the first mounting plate and is positioned between the two first chutes, a wing plate positioning slide block is arranged on the first slide rail in a matching way, a first cylinder is also fixedly arranged at one end of the first mounting plate, a second positioning channel steel with the length arranged is arranged on one side of the lifting workbench, at least two longitudinal beam front end pressing and positioning tools are further arranged on the lifting workbench and comprise a second mounting plate, second sliding grooves are formed in positions on two sides of the second mounting plate, second sliding blocks capable of sliding along the second sliding grooves are installed in the second sliding grooves in a matching mode, detachable second web plate positioning channel steel is installed on the second sliding blocks on the two sides, a second air cylinder is fixedly installed at one end of the second mounting plate, gooseneck cushion blocks are arranged on two sides of the second air cylinder, through holes matched with the second web plate positioning channel steel are formed in the gooseneck cushion blocks, workbench lifting devices are arranged at positions on two ends of the bottom of the lifting workbench and comprise worm wheel lifters arranged at the bottom of the lifting workbench, and first driving motors are installed on the worm wheel lifters at one end of the workbench, the worm and gear elevators at the two ends are connected through a first universal coupling, the lifting roller system comprises a lifting frame, lifting cylinders are arranged at the two ends of the bottom of the lifting frame, at least two groups of roller devices are arranged on the lifting frame, the roller devices comprise mounting seats fixed on two sides of the lifting frame, a rotating roller capable of freely rotating is arranged between the mounting seats, a first gear is arranged on a rotating shaft at one end of the rotating roller, a second gear is arranged at the bottom of the lifting frame corresponding to the position of the first gear, a third gear and a fourth gear are coaxially arranged on the mounting shaft of the second gear, wherein a first chain is connected between the first gear and the second gear, a second chain is connected between the third gear or the fourth gear between two adjacent roller wheel devices, and a second driving motor is arranged at the bottom of one of the roller devices, and an output shaft of the second driving motor is connected with a mounting shaft of the second gear.

Further, be equipped with second location channel-section steel adjusting device on the elevating platform, second location channel-section steel adjusting device includes the regulating unit the same with second mounting panel quantity, and every regulating unit all includes the lead screw that is located second mounting panel bottom, cooperation mounting nut on the lead screw, fixed mounting ejector pad on the nut, set up on the second mounting panel with ejector pad matched with rectangle through groove, the ejector pad passes through groove via the rectangle and wears out second mounting panel and second location channel-section steel fixed connection, worm gear transmission is installed to the one end that the lead screw wore out the second mounting panel, links to each other by second universal joint between two adjacent worm gear transmission's the worm, still installs third driving motor on the elevating platform, and third driving motor's output shaft links to each other with one of them worm gear transmission.

Further, the one end that elevating platform is close to fixed work platform is installed and can be pivoted second cylinder, be equipped with the rotation axis between second cylinder one end and the second mounting panel, the other end installation quick detach locking of second cylinder is detained, still seted up on the second mounting panel with quick detach locking detain matched with arc wall.

Further, a top plate is arranged between the worm gear lifter and the lifting workbench, the worm gear lifter is installed on the bottom plate, a vertically arranged guide rod is installed on the top plate, and a guide sleeve matched with the guide rod is installed on the bottom plate.

Furthermore, tensioning gears are arranged between the adjacent roller devices and hinged to the lifting frame through connecting plates.

The utility model has the advantages of: a solebar point solid frock, can highly adapt to the gooseneck roof beam of various different grade types through adjusting front end, rear end compress tightly location frock and elevating platform, the investment of reducible equipment, reduction in production cost, web location channel-section steel, pterygoid lamina location slider and rotatable cylinder can carry out effective spacing fixed to the solid web of concatenation point and pterygoid lamina, prevent welding deformation, the lift roller system of independent setting can also make the work piece on the workstation remove to carry out the solid frock of point in batches to the solebar, in addition, the utility model discloses still have the location reliable, the point solid is efficient, simple structure, convenient to use and advantage of maintaining.

Drawings

Fig. 1 is a schematic three-dimensional structure of the present invention;

FIG. 2 is a schematic structural view of a stationary table;

FIG. 3 is a schematic structural view of a longitudinal beam rear end pressing and positioning tool;

FIG. 4 is a schematic structural view of the elevating table;

FIG. 5 is a schematic structural view of a longitudinal beam front end pressing and positioning tool;

FIG. 6 is a schematic structural view of a lift roller system;

FIG. 7 is an enlarged partial view of II in FIG. 6;

FIG. 8 is a schematic structural diagram of a second positioning channel steel adjusting device;

FIG. 9 is a schematic view of a second rotatable cylinder;

FIG. 10 is an enlarged partial view of I of FIG. 4;

FIG. 11 is a schematic view showing a state of clamping a workpiece according to the present invention;

FIG. 12 is a schematic three-dimensional structure of the elevating table;

fig. 13 is a schematic structural view of the table lifting device.

In the drawing, a fixed workbench 2, a lifting workbench 3, a first chain 4, a first positioning channel steel 5, a first slide groove 7, a first slide block 8, a first web positioning channel steel 9, a first slide rail 10, a wing plate positioning slide block 11, a first cylinder 12, a second positioning channel steel 13, a second mounting plate 14, a second slide groove 15, a second web positioning channel steel 17, a second cylinder 18, a gooseneck cushion block 19, a through hole 20, a worm gear lifter 21, a first driving motor 22, a first universal coupler 23, a lifting frame 24, a lifting cylinder 25, a mounting seat 26, a rotating roller 27, a first gear 28, a second gear 29, a third gear 30, a second chain 32, a lead screw 34, a nut 35, a pushing block 36, a rectangular through groove 37, a worm gear transmission 38, a second universal coupler 39, a rotating shaft 41, a locking buckle 42, a top plate 43, a bottom plate 44, a guide rod 46, a guide sleeve 47 and a tensioning gear connecting plate 48 wing plate 50 of a web.

Detailed Description

A solebar point solid frock, as shown in fig. 1, including fixed station 1 and elevating platform 2, elevating platform 2 can adjust vertical height as required and provide better support and centre gripping for the gooseneck part of gooseneck roof beam to ensure the quality of the operation of point solid. All install the lift roller system in fixed work platform 1 and the elevating platform 2, the lift roller system can stretch out on table surface to in with welding such as web 49 and pterygoid lamina 50 transport fixed work platform 1 and elevating platform 2.

As shown in fig. 2, one side of the fixed workbench 1 is provided with a first positioning channel steel 4 arranged along the length thereof so as to position the wing plate 50 attached thereto, and at least two longitudinal beam rear end pressing and positioning tools are further arranged on the fixed workbench 1 to clamp and position two wing plates 50 and a web plate 49 at the rear end of the longitudinal beam. As shown in fig. 3, longeron rear end compression positioning fixture includes first mounting panel 5, first mounting panel 5 sets up on fixed bolster 1, first spout 6 has all been seted up to the both sides position department of first mounting panel 5, first spout 6 fit in is installed and can be followed its gliding first slider 7, install the first web location channel-section steel 8 of detachable on the first slider 7 of both sides, first web location channel-section steel 8 is used for fixing a position web 49 on fixed bolster 1, wherein the removable not co-altitude type of first web location channel-section steel 8 to web 49 suitable for the different grade type. Still install first slide rail 9 on first mounting panel 5, first slide rail 9 is located between two first spouts 6, pterygoid lamina location slider 10 is installed in the cooperation on first slide rail 9, and pterygoid lamina location slider 10 can move on first slide rail 9, can adjust the position of pterygoid lamina location slider 10 on first slide rail 9 as required to carry out the prepositioning installation to the pterygoid lamina 50 of different thickness types, still be fixed with first cylinder 11 of installation in the one end of first mounting panel 5, can compress tightly the location with pterygoid lamina 50 and the middle web 49 of both sides after the piston rod of first cylinder 11 stretches out.

As shown in fig. 4, one side of the lifting table 2 is provided with a second positioning channel 12 with a length arranged so as to position the wing plate 50 of the gooseneck portion at the front end of the longitudinal beam, and at least two longitudinal beam front end pressing and positioning tools are further provided on the lifting table 2 to clamp and position two wing plates 50 and a web plate 49 of the gooseneck portion at the front end of the longitudinal beam. As shown in fig. 5, longeron front end compression positioning fixture includes second mounting panel 13, second mounting panel 13 sets up on elevating platform 2, second spout 14 has all been seted up to the both sides position department of second mounting panel 13, second spout 14 fit in is installed and can be followed its gliding second slider 15, install detachable second web location channel-section steel 16 on the second slider 15 of both sides, it has second cylinder 17 still to fix at the one end of second mounting panel 13, the piston rod of second cylinder 17 stretches out and to compress tightly the location with pterygoid lamina 50 and the web 49 in the middle of both sides. In order to adapt to the distance between the wing plates 50 of different types of gooseneck beams at the bent positions, gooseneck cushion blocks 18 are arranged on two sides of the second air cylinder 17, through holes 19 matched with the second web positioning channel steel 16 are formed in the gooseneck cushion blocks 18, if the length of a piston rod of the second air cylinder 17 is not enough to be pressed on the wing plates 50, as shown in fig. 11, the gooseneck cushion blocks 18 can be installed on the second web positioning channel steel 16, the piston rod of the second air cylinder 17 pushes the gooseneck cushion blocks 18 to press the wing plates 50 and the web plates 49 tightly, wherein the gooseneck cushion blocks 18 can be replaced by different length types so as to be suitable for pressing the wing plates 50 of different types.

In order to adapt to the difference in height between the webs 49 at the bottom of the gooseneck beams of different types, better support and clamping are improved, a workbench lifting device is arranged at the two ends of the bottom of the lifting workbench 2, as shown in fig. 4, the workbench lifting device comprises a worm gear lifter 20 arranged at the bottom of the lifting workbench 2, a first driving motor 21 is arranged on the worm gear lifter 20 at one end, the worm gear lifters 20 at the two ends are connected through a first universal coupling 22, the first driving motor 21 is started to drive the worm gear lifters 20 at the two ends to vertically lift the lifting workbench 2, and therefore the gooseneck beams of different types can be fixed at predetermined positions.

As shown in fig. 6, the lifting roller system includes a lifting frame 23, wherein lifting cylinders 24 are respectively disposed at two ends of the bottom of the lifting frame 23, and at least two sets of roller devices are disposed on the lifting frame 23 for transporting a workpiece on a workbench. As shown in fig. 7, the roller device includes mounting seats 25 fixed on both sides of the lifting frame 23, a roller 26 capable of rotating freely is arranged between the mounting seats 25, a first gear 27 is mounted on a rotating shaft at one end of the roller 26, a second gear 28 is mounted at the bottom of the lifting frame 23 corresponding to the position of the first gear 27, a third gear 29 and a fourth gear 30 are coaxially arranged on a mounting shaft of the second gear 28, wherein a first chain 3 is connected between the first gear 27 and the second gear 28, a second chain 31 is connected between the third gear 29 or the fourth gear 30 between two adjacent roller devices, a second driving motor 32 is mounted at the bottom of one of the roller devices, and an output shaft of the second driving motor 32 is connected with a mounting shaft of the second gear 28. Adopt the transmission of above-mentioned structure, drive via a second driving motor 32, all change roller 26 homoenergetic and realize synchronous rotation to the realization is to the transportation of work piece, and the lift cylinder can drive all gyro wheel devices in step and carry out vertical lift, when falling under table surface, can realize placing the work piece on the workstation, when vertical rising on table surface, can keep away from the workstation with the work piece jack-up transportation of the solid completion of point.

When the vehicle frame longitudinal beam point fixing tool is used, the positions of a first web plate positioning channel steel 8 and a wing plate positioning slide block 10 on a fixed workbench 1 are adjusted, the position of a second web plate positioning channel steel 16 on a lifting workbench 2 is adjusted, then a lifting roller system in the fixed workbench 1 and the lifting workbench 2 is lifted from a workbench surface, a web plate 49 to be point fixed is placed on a rotary roller 26, a second driving motor 32 is started to move the web plate 49 to a prepositioned position, a lifting cylinder 24 is recovered, the rotary roller 26 is lowered below the web plate positioning channel steel, the web plate 49 falls onto the web plate positioning channel steel of the workbench, then wing plates 50 are installed from the two side positions of the web plate 49, the rotary roller 26 rotates to drive the wing plates 50 to a specified position, the lifting cylinder 24 is recovered again, the rotary roller 26 is lowered below the workbench surface, piston rods of a first cylinder 11 and a second cylinder 17 are extended out, the wings 50 are pressed into position on the web 49.

Furthermore, in order to adjust the installation position of the wing plate 50 on the lifting table 2 according to the distance between the wing plate 50 at the gooseneck portion of the gooseneck beam on the lifting table 2 and the wing plate 50 on the fixed table 1, that is, the distance between the wing plate 50 at the gooseneck bending portion of the gooseneck beam, the lifting table 2 is provided with a second positioning channel 12 adjusting device, as shown in fig. 8, the second positioning channel 12 adjusting device comprises adjusting units with the same number as the second mounting plate 13, each adjusting unit comprises a lead screw 33 located at the bottom of the second mounting plate 13, the lead screw 33 is matched with a mounting nut 34, a push block 35 is fixedly mounted on the nut 34, the second mounting plate 13 is provided with a rectangular through groove 36 matched with the push block 35, the push block 35 penetrates through the second mounting plate 13 via the rectangular through groove 36 to be fixedly connected with the second positioning channel 12, one end of the lead screw 33 penetrating through the second mounting plate 13 is provided with a worm gear 37, the worm gear 37 may be a worm gear as described in patent No. CN201280042168.8 entitled "tap changer comprising worm gear". The worms of two adjacent worm gear transmission devices 37 are connected by a second universal coupling 38, a third driving motor 39 is further mounted on the lifting workbench 2, and an output shaft of the third driving motor 39 is connected with one of the worm gear transmission devices 37. When the third driving motor 39 is started, the pushing blocks 35 in the adjusting units can be driven to move along the lead screw 33 through the transmission of the worm gear transmission device 37 and the second universal coupling 38, so that the position of the second positioning channel steel 12 on the lifting workbench 2 can be adjusted.

Further, as shown in fig. 11, in order to compress and position the wing plate 50 at the bending portion of the gooseneck beam, a rotatable second cylinder 17 is installed at one end of the lifting workbench 2 close to the fixed workbench 1, as shown in fig. 9, a rotating shaft 40 is installed between one end of the second cylinder 17 and the second mounting plate 13, a quick release locking buckle 41 is installed at the other end of the second cylinder 17, an arc-shaped groove 42 matched with the quick release locking buckle 41 is further formed in the second mounting plate 13, wherein the quick release locking buckle 41 can be a quick release locking device described in the patent CN201720358040.2 entitled "anti-rotation quick release locking buckle for lifting rod of bicycle seat cushion", when the quick release locking buckle 41 is locked, one end of the second cylinder 17 can be positioned in the arc-shaped groove 42, when the quick release locking buckle 41 is released, the second cylinder 17 can rotate at any angle with the rotating shaft 40 as the center, the bent wing plate 50 can be positioned until the piston rod of the second cylinder 17 is extended. Wherein the arc wall 42 also can install the double-end has the double-screw bolt of nut, and the nut of screwing just can be fixed a position the second cylinder 17 on second mounting panel 13, and the rotation angle of second cylinder 17 just can be adjusted wantonly to the nut of unscrewing, and the here sets up the location dismouting that can be convenient for to second cylinder 17 more of quick detach locking knot 41 to improve the work efficiency of adjustment second cylinder 17. In order to adapt to the clamping and positioning of the gooseneck beams of different types and the wing plates 50 at the bent parts of the gooseneck beams, the first air cylinder 11 on the fixed workbench 1 can also be provided with a rotatable air cylinder as required.

Further, in order to ensure that the lifting workbench 2 can be more stable in the lifting process, as shown in fig. 10, a top plate 43 is arranged between the worm and gear lifter 20 and the lifting workbench 2, the worm and gear lifter 20 is installed on a bottom plate 44, a guide rod 45 vertically arranged is installed on the top plate 43, a guide sleeve 46 matched with the guide rod 45 is installed on the bottom plate 44, and the guide rod 45 and the guide sleeve 46 which are matched with each other can ensure that the worm and gear lifter 20 cannot deflect when driving the lifting workbench 2 to vertically lift, and can stably lift.

Further, in order to ensure that the adjacent roller devices can smoothly transmit through the second chain 31, as shown in fig. 6 and 7, a tensioning gear 47 is arranged between the adjacent roller devices, the tensioning gear 47 is hinged on the lifting frame 23 through a connecting plate 48, and the second chain 31 can be tensioned or loosened by adjusting the hinged position between the tensioning gear 47 and the lifting frame 23, so that the second chain 31 is under a normal transmission load, and the normal transmission is ensured.

Technical scheme of the utility model not be restricted to the utility model the within range of embodiment. The technical contents not described in detail in the present invention are all known techniques.

Claims

1. The utility model provides a solebar point solid frock, includes fixed station (1) and elevating platform (2), all installs the lift roller system in fixed station (1) and elevating platform (2), its characterized in that: one side of the fixed workbench (1) is provided with a first positioning channel steel (4) arranged along the length of the fixed workbench, the fixed workbench (1) is further provided with at least two longitudinal beam rear end pressing positioning tools, each longitudinal beam rear end pressing positioning tool comprises a first mounting plate (5), two side positions of each first mounting plate (5) are respectively provided with a first chute (6), a first sliding block (7) capable of sliding along the first chute (6) is installed in the first chute in a matched mode, a detachable first web positioning channel steel (8) is installed on the first sliding blocks (7) on the two sides, a first sliding rail (9) is further installed on each first mounting plate (5), each first sliding rail (9) is located between the two first chutes (6), a wing plate positioning sliding block (10) is installed on each first sliding rail (9) in a matched mode, a first air cylinder (11) is further fixedly installed at one end of each first mounting plate (5), a second positioning channel steel (12) arranged along the length direction of the lifting workbench (2) is arranged on one side of the lifting workbench (2), at least two longitudinal beam front end pressing and positioning tools are further arranged on the lifting workbench (2), the longitudinal beam front end pressing and positioning tools comprise a second mounting plate (13), second sliding grooves (14) are formed in positions on two sides of the second mounting plate (13), second sliding blocks (15) capable of sliding along the second sliding grooves are mounted in the second sliding grooves (14) in a matching manner, detachable second web positioning channel steel (16) is mounted on the second sliding blocks (15) on two sides, a second air cylinder (17) is fixedly mounted at one end of the second mounting plate (13), gooseneck cushion blocks (18) are arranged on two sides of the second air cylinder (17), through holes (19) matched with the second web positioning channel steel (16) are formed in the gooseneck cushion blocks (18), and workbench lifting devices are arranged at positions on two ends of the bottom of the lifting workbench (2), the workbench lifting device comprises a worm gear lifter (20) arranged at the bottom of a lifting workbench (2), wherein a first driving motor (21) is arranged on the worm gear lifter (20) at one end, the worm gear lifters (20) at two ends are connected through a first universal coupling (22), the lifting roller system comprises a lifting frame (23), lifting cylinders (24) are arranged at two ends of the bottom of the lifting frame (23), at least two groups of roller devices are arranged on the lifting frame (23), the roller devices comprise mounting seats (25) fixed at two sides of the lifting frame (23), rotating rollers (26) capable of rotating freely are arranged between the mounting seats (25), a first gear (27) is arranged on a rotating shaft at one end of each rotating roller (26), a second gear (28) is arranged at the bottom of the lifting frame (23) and corresponds to the position of the first gear (27), a third gear (29) and a fourth gear (30) are coaxially arranged on a mounting shaft of the second gear (28), a first chain (3) is connected between the first gear (27) and the second gear (28), a second chain (31) is connected between the third gear (29) or the fourth gear (30) between two adjacent roller devices, a second driving motor (32) is mounted at the bottom of one of the roller devices, and an output shaft of the second driving motor (32) is connected with a mounting shaft of the second gear (28).

2. The frame rail point fixing tool according to claim 1, characterized in that: be equipped with second location channel-section steel (12) adjusting device on elevating platform (2), second location channel-section steel (12) adjusting device includes the regulating unit the same with second mounting panel (13) quantity, every regulating unit all includes lead screw (33) that are located second mounting panel (13) bottom, cooperation mounting nut (34) are gone up in lead screw (33), fixed mounting ejector pad (35) are gone up in nut (34), set up on second mounting panel (13) and pass through groove (36) with ejector pad (35) matched with rectangle, ejector pad (35) pass through groove (36) via the rectangle and wear out second mounting panel (13) and second location channel-section steel (12) fixed connection, worm gear (37) are installed to the one end that second mounting panel (13) were worn out in lead screw (33), link to each other by second universal joint (38) between the worm of two adjacent worm gear (37), a third driving motor (39) is also arranged on the lifting workbench (2), and an output shaft of the third driving motor (39) is connected with one worm gear transmission device (37).

3. The frame rail point fixing tool according to claim 1, characterized in that: elevating platform (2) are close to the one end of fixed station (1) and install second cylinder (17) that can rotate, be equipped with rotation axis (40) between second cylinder (17) one end and second mounting panel (13), the other end installation quick detach locking of second cylinder (17) is detained (41), still seted up on second mounting panel (13) and detained (41) matched with arc wall (42) with quick detach locking.

4. The frame rail point fixing tool according to claim 1, characterized in that: be equipped with roof (43) between worm gear lift (20) and elevating platform (2), worm gear lift (20) are installed on bottom plate (44), install guide bar (45) of vertical setting on roof (43), install on bottom plate (44) with guide bar (45) matched with uide bushing (46).

5. The frame rail point fixing tool according to claim 1, characterized in that: tensioning gears (47) are arranged between the adjacent roller devices, and the tensioning gears (47) are hinged to the lifting frame (23) through connecting plates (48).