CN113976985B

CN113976985B - Clamping and moving device for stainless steel pipe rotary cutter

Info

Publication number: CN113976985B
Application number: CN202111261983.0A
Authority: CN
Inventors: 李家泉; 张剑; 盖波; 左维林
Original assignee: Shandong Kingread New Materials Polytron Technologies Inc
Current assignee: Shandong Kingread New Materials Polytron Technologies Inc
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2022-07-12
Anticipated expiration: 2041-10-28
Also published as: CN113976985A

Abstract

The utility model provides a clamping mobile device for nonrust steel pipe peeler, including the pay-off platform, top surface one side of pay-off platform is equipped with the blanking slope, set up through groove on the blanking slope, the length direction who follows the blanking slope of length direction through groove, through the inslot is equipped with the pivot, the periphery of pivot is equipped with several bar board, the first drive wheel of fixed mounting behind the through groove is run through to the one end of pivot, the below of pay-off platform is equipped with two at least second drive wheels, power device is connected to one of them second drive wheel, all second drive wheels are connected through first drive belt, the second drive wheel coaxial arrangement third drive wheel of first drive wheel below, third drive wheel and first drive wheel pass through the second drive belt and connect. This device can realize the rotary-cut material loading of three at least steel pipes in the short time, and many rotary-cut production lines need not to correspond and set up many sets of feed mechanism promptly, can save the spending of enterprise's acquisition of equipment, and is minimum to production efficiency's influence.

Description

Clamping and moving device for stainless steel pipe rotary cutter

Technical Field

The invention belongs to the field of rotary cutter feeding, and particularly relates to a clamping moving device for a stainless steel pipe rotary cutter.

Background

At present, when the steel pipe is rotary cut, the steel pipe is generally conveyed to a rotary cutting part by a feeding part of a rotary cutter, then the rotary cutting part clamps the steel pipe and drives the steel pipe to rotate, and then a cutter is fed until the steel pipe is cut off. The conventional rotary cutting machine is generally provided with one-to-one matching of feeding and rotary cutting, a steel pipe is separated in a feeding part through gas/hydraulic pressure and the like so as to realize single intermittent feeding, a plurality of rotary cutting machines synchronously work in an actual production workshop, each rotary cutting machine comprises an independent feeding system, but the feeding time is only less than 5% of the whole processing time, and serious resource waste is caused.

Disclosure of Invention

The invention provides a clamping and moving device for a stainless steel tube rotary cutter, which is used for overcoming the defects in the prior art.

The invention is realized by the following technical scheme:

a clamping and moving device for a stainless steel pipe rotary cutter comprises a feeding table, wherein a blanking slope is arranged on one side of the top surface of the feeding table, a through groove is formed in the blanking slope, the length direction of the through groove is in compliance with the length direction of the blanking slope, a rotating shaft is arranged in the through groove, a plurality of strip plates are arranged on the periphery of the rotating shaft, a first driving wheel is fixedly installed at one end of the rotating shaft after penetrating through the through groove, at least two second driving wheels are fixedly installed below the feeding table, one of the second driving wheels is connected with a power device, all the second driving wheels are connected through a first driving belt, a third driving wheel is coaxially installed on the second driving wheel below the first driving wheel, the third driving wheel is connected with the first driving wheel through a second driving belt, a plurality of flexible racks are fixedly installed on the inner ring of the first driving belt, a plurality of V-shaped grooves are formed in the top surface of the feeding table, except for one V-shaped groove far away from the blanking slope, blocking pieces are arranged in the other V-shaped grooves, the plugging piece drives the flexible rack to unfold or fold, and when the plugging piece is unfolded, the top of the V-shaped groove is closed.

The clamping moving device for the stainless steel pipe rotary cutter comprises two hinged movable plates, sliding grooves are formed in the tops of two sides of a V-shaped groove respectively, sliding blocks in sliding fit with the sliding grooves are arranged in the sliding grooves respectively, opposite sides of the two movable plates are connected with the corresponding sliding blocks in a rotating mode respectively, through holes are formed in the bottoms of the V-shaped groove vertically, ejector rods are arranged in the through holes respectively, the hinged parts of the two movable plates are connected with the upper ends of the corresponding ejector rods, the lower ends of the ejector rods are hinged with the upper ends of push-pull rods, the lower ends of the push-pull rods are connected with the eccentric parts of a disc in a rotating mode, the disc is coaxially connected with first gears, the first gears are located in a first transmission belt, and adjacent first gears are arranged in a staggered mode.

According to the clamping moving device for the stainless steel pipe rotary cutter, both sides of the movable plate are of wedge-shaped structures.

According to the clamping and moving device for the stainless steel pipe rotary cutter, the supporting legs are fixedly arranged on two sides of the bottom surface of the feeding table.

The clamping moving device for the stainless steel tube rotary cutter is characterized in that the blanking slope is composed of an L-shaped plate and an inclined plate, and the through groove is positioned on the inclined plate.

The clamping moving device for the stainless steel pipe rotary cutter comprises a V-shaped groove, wherein one end of the V-shaped groove is provided with a pipe conveying mechanism, the pipe conveying mechanism comprises two moving seats, the two moving seats are respectively positioned at two sides of the V-shaped groove, each moving seat is provided with at least two rollers in a rotating mode, one of the moving seats is connected with a telescopic rod, one of the moving seats is provided with a chain wheel structure, the chain wheel structure is used for enabling the corresponding rollers to rotate, the opposite sides of the two moving seats are respectively provided with a second rack, and the two second racks are arranged in a staggered mode and are meshed with a second gear together.

The invention has the advantages that: this device can realize the rotary-cut material loading of three at least steel pipes in the short time, and many rotary-cut production lines need not to correspond and set up many sets of feed mechanism promptly, can save the spending of enterprise's acquisition of equipment, and is minimum to production efficiency's influence. When the blanking device is used, a steel pipe is placed on the blanking slope and positioned above the rotating shaft, at the moment, one strip-shaped plate is perpendicular to the blanking slope, the steel pipe cannot fall down due to the fact that the strip-shaped plate is blocked by the strip-shaped plate, after the strip-shaped plate rotates along with the rotating shaft and enters the through groove, the steel pipe can roll to the feeding platform along the blanking slope and falls into the rightmost V-shaped groove under the action of inertia, then, other plugging pieces are sequentially folded from right to left, after the plugging piece closest to the blanking slope is folded, one round of feeding is completed, after the steel pipe in the V-shaped groove is fed into the corresponding rotary cutting mechanism, all the plugging pieces are synchronously unfolded, and the next round of feeding is started. The device realizes the positioning of the pipe fitting by means of gravity and a physical structure, and has high reliability; connecting a motor with a PLC control system, operating according to the steps, adjusting time intervals, and enabling the pipe fitting to pass through the closed V-shaped groove, so that automatic operation can be realized; the rotating shaft and the first transmission belt run synchronously, so that the blanking of the pipe fitting and the opening and closing of the V-shaped groove are synchronous, and the pipe fitting does not need to fall through a sensor or a switch part; for material loading, rotary-cut one-to-one match, this device can be with many sets of rotary-cut mechanism next-door neighbour settings, and occupation space is littleer, and the workman only need put the pipe fitting on blanking slope can supply many rotary-cut mechanism work, also has great meaning to saving artifical cost.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural view and a first embodiment of a plugging member according to the present invention; FIG. 2 is an enlarged view of the view from the direction A of FIG. 1; FIG. 3 shows a second embodiment of the closure; FIG. 4 is an enlarged view of the view of FIG. 1 taken along line B; fig. 5 is an enlarged view of a portion i of fig. 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

A clamping and moving device for a stainless steel tube rotary cutter comprises a feeding table 1, wherein a blanking slope 2 is arranged on one side of the top surface of the feeding table 1, stainless steel tubes are placed on the blanking slope 2 in batches, through grooves 3 are formed in the blanking slope 2, the length direction of the through grooves 3 is in accordance with the length direction of the blanking slope 2, namely the through grooves are longitudinally arranged and are smaller than the length of the steel tubes to be processed, rotating shafts 4 are arranged in the through grooves 3 and are also longitudinally arranged, a plurality of strip-shaped plates 5 are arranged on the periphery of the rotating shafts 4 and are uniformly distributed, the length of the strip-shaped plates 5 is smaller than that of the rotating shafts 4, the strip-shaped plates 5 are perpendicular to and fixedly connected with the rotating shafts 4, a first driving wheel 6 is fixedly arranged after one end of the rotating shafts 4 penetrates through the through grooves 3, bearings are arranged at the penetrating positions, at least two second driving wheels 7 are arranged below the feeding table 1, one of the second driving wheels 7 is connected with a power device, and the power device is a motor, all the second transmission wheels 7 are connected through a first transmission belt 8, a third transmission wheel 9 is coaxially arranged on the second transmission wheel 7 below the first transmission wheel 6, the third transmission wheel 9 is connected with the first transmission wheel 6 through a second transmission belt 10, a plurality of groups of flexible racks are fixedly arranged on the inner ring of the first transmission belt 8 and are made of fiber twisting or weaving and then coating glue, the radian of the fiber passing through the second transmission wheel 7 can be adapted through deformation, each group of flexible racks comprises a first rack 11, a second rack 12 and a third rack 13, the lengths of the first rack 11 and the second rack 12 are equal, the length of the third rack 13 is twice as long as that of the first rack 11 and the second rack 12, the third rack 13 is distributed with the first rack 11 and the second rack 12 in a staggered manner, the first rack 11 and the second rack 12 are positioned on the same straight line, the top surface of the feeding table 1 is provided with a plurality of V-shaped grooves 14, and the front end and the rear end of the V-shaped grooves 14 are both opened, in this embodiment, the number of the V-shaped grooves 14 is 3, and at most, the number of the V-shaped grooves is not more than 5, the V-shaped grooves are respectively aligned with a feeding port of a rotary cutting mechanism, except for one V-shaped groove 14 far away from the blanking slope 2, the other V-shaped grooves 14 are internally provided with a blocking piece, the blocking piece drives the blocking piece to be unfolded or folded through a flexible rack, and when the blocking piece is unfolded, the top of the V-shaped groove 14 is closed. This device can realize the rotary-cut material loading of three at least steel pipes in the short time, and many rotary-cut production lines need not to correspond and set up many sets of feed mechanism promptly, can save the spending of enterprise's acquisition equipment, and is minimum to production efficiency's influence. During the use, put the steel pipe on blanking slope 2 and be located the top of pivot 4, at this moment, one of them strip shaped plate 5 is perpendicular to blanking slope 2, the steel pipe is stopped unable whereabouts by strip shaped plate 5, after this strip shaped plate 5 rotated along with pivot 4 and gets into through groove 3, the steel pipe just can roll to the pay-off platform 1 along blanking slope 2, and fall into rightmost V-arrangement groove 14 under the inertia effect, afterwards, remaining shutoff piece is folded from the right side to the left side in proper order, after the shutoff piece that is closest to blanking slope 2 is folded, a round of material loading action was accomplished, after the steel pipe in V-arrangement groove 14 sent into corresponding rotary-cut mechanism, all shutoff pieces expand in step, begin the next round of material loading. The device realizes the positioning of the pipe fitting by means of gravity and a physical structure, and has high reliability; connecting a motor with a PLC control system, operating according to the steps, adjusting time intervals, and enabling the pipe fitting to pass through the closed V-shaped groove 14, so that automatic operation can be realized; the rotating shaft 4 and the first transmission belt 8 run synchronously, so that the blanking of the pipe fitting and the opening and closing of the V-shaped groove 14 are synchronous, and the pipe fitting does not need to fall through a sensor or a switch part; for material loading, rotary-cut one-to-one match, this device can be with many sets of rotary-cut mechanism next-door neighbour settings, and occupation space is littleer, and the workman only need put the pipe fitting on blanking slope 2 can supply many rotary-cut mechanism work, also has great meaning to saving the cost of labor.

Specifically, as shown in fig. 1, the plugging member of this embodiment includes two hinged movable plates 15, which are connected by a hinge, when the two movable plates 15 are unfolded, the top of the V-shaped groove 14 can be sealed, the distance between the movable plates 15 and the V-shaped groove 14 when folded and the distance between the movable plates 15 when unfolded are both smaller than the diameter of the steel pipe, sliding grooves 16 are respectively formed at the tops of both sides of the V-shaped groove 14, sliders 17 in sliding fit with the sliding grooves 16 are respectively arranged in the sliding grooves 16, the opposite sides of the two movable plates 15 are respectively rotatably connected with the corresponding sliders 17 and connected by a hinge base, through holes 18 are vertically formed at the bottom of the V-shaped groove 14, push rods 19 are respectively arranged in the through holes 18, the hinge joint of the two movable plates 15 is connected with the upper ends of the corresponding push rods 19, the pin shaft of the hinge is embedded in the upper end of the push rod 19, the pin shaft can rotate at the embedded position, the lower end of the push rod 19 is hinged with the upper end of the push rod 20, the lower end of the push-pull rod 20 is rotatably connected with the eccentric position of the disc 21, the disc 21 is coaxially connected with the first gear 22, the disc 21 is positioned between the first gear 22 and the push-pull rod 20, the first gear 22 and the disc 21 are installed on the bottom surface of the feeding table 1 through the wheel carrier, the first gear 22 and the disc 21 are connected with the wheel carrier through the damping shaft, the rotating resistance is larger than the gravity of a steel pipe, the first gear 22 is positioned in the first transmission belt 8, and the adjacent first gears 22 are arranged in a staggered mode. The first gear 22 adjacent to the blanking slope 2 is only meshed with the third rack 13, the other first gear 22 can be sequentially meshed with the first rack 11 and the second rack 12, in an initial state, the movable plate 15 is in an unfolded state, the first transmission belt 8 and the second transmission belt 10 both intermittently rotate, each rotation of the second transmission belt 10 drives the third transmission wheel 9 to rotate 90 degrees, and each rotation range of the first transmission belt 8 is equal to the length of the first rack 11. The third driving wheel 9 rotates for the first time, the plugging piece does not move, and the movable plate 15 is flush with the top surface of the feeding table 1; during the second rotation, the first rack 11 is meshed with the first gear 22 on the right side and drives the first gear 22 to rotate for half a circle, the push-pull rod 20 pulls the ejector rod 19 to move downwards, the two corresponding movable plates 15 are folded into a V shape, and the sliding block 17 can also fall to the bottom from the top of the sliding groove 16; in the third rotation, the third rack 13 is meshed with the first gear 22 on the left side to a half, and the movable plate 15 on the left side is folded into a V shape; during the fourth rotation, the third rack 13 is continuously meshed with the first gear 22 on the left side, the first gear 22 on the right side is meshed with the second rack 12, the movable plates 15 are unfolded, and the steel pipes rolled down along the blanking slope 2 fall into the rightmost V-shaped groove 14 along the top surface of the feeding table 1. The structure has the advantages that the reaction is rapid when the structure is unfolded and folded, the structure is supported by the ejector rod 19 when the structure is unfolded, the stability is high, the folded shape is the same as that of the V-shaped groove 14, and the steel pipe can be prevented from being punched out of the V-shaped groove 14 under the inertia effect.

Specifically, as shown in fig. 1, both sides of the movable plate 15 in the present embodiment are wedge-shaped structures. This structure can prevent the two movable plates 15 from interfering with each other, so that they can be unfolded or folded smoothly and maximally.

Further, as shown in fig. 1, a plurality of support legs 23 are fixedly installed on two sides of the bottom surface of the feeding table 1 according to the embodiment. The second driving wheel 7 positioned below the blanking slope 2 is arranged on the supporting leg 23 on the corresponding side through a wheel frame, and the other second driving wheel 7 is connected with the bottom surface of the feeding table 1 through the wheel frame.

Further, as shown in fig. 1, the blanking slope 2 of the present embodiment is composed of an L-shaped plate 2-1 and an inclined plate 2-2, and the through groove 3 is located on the inclined plate 2-2. The L-shaped plates 2-1 are used for storing the next batch of steel pipes to be processed, the steel pipes on the inclined plates 2-2 are under the action of gravity, and when the strip-shaped plates 5 rotate along with the rotating shaft 4, one steel pipe falls between every two adjacent strip-shaped plates 5 and turns downwards until the steel pipe is separated from the strip-shaped plates 5. The inclined plate 2-2 is connected with the side surface of the feeding table 1 through an L-shaped bracket so as to ensure that the blanking slope 2 has enough bearing capacity. Through two at least bolted connection between every strip shaped plate 5 and the pivot 4, its width equate the steel pipe diameter can, if the steel pipe size of processing changes by a wide margin, can adapt to through changing strip shaped plate 5 to only there is a steel pipe between every two adjacent strip shaped plate 5.

Furthermore, as shown in fig. 2, in the embodiment, a pipe feeding mechanism is disposed at one end of the V-shaped groove 14, the pipe feeding mechanism is disposed between the feeding table 1 and the rotary cutting mechanism, and the present device does not change the existing rotary cutting process, and therefore, the rotary cutting mechanism is not described in detail, the pipe feeding mechanism includes two movable seats 24, the two movable seats 24 are disposed at two sides of the V-shaped groove 14, at least two rollers 25 are rotatably mounted on each movable seat 24, when in actual use, the rollers 25 are parallel to the ground, the arrangement direction of the rollers 25 at the same side conforms to the length direction of the V-shaped groove 14, one of the movable seats 24 is connected to a telescopic rod 26, the telescopic rod 26 is a hydraulic cylinder, one of the movable seats 24 is provided with a sprocket structure, the sprocket structure is configured to rotate the corresponding roller 25, the sprocket structure includes three sprockets, two of the three sprockets are coaxially connected to the corresponding roller 25, the last one is coaxially connected with the output end of the motor, the opposite sides of the two moving seats 24 are respectively provided with a second rack 27, the two second racks 27 are arranged in a staggered manner and are meshed with a second gear 28 together, the positions of the second gears 28 are fixed through shafts and the like, the moving seats 24 are provided with slotted holes 29 corresponding to the second racks 27, and when the distance between the rollers 25 is small, the second racks 27 can extend into the slotted holes 29. The structure can enable the two moving seats 24 to move oppositely or oppositely at the same time, and the two moving seats can be symmetrical by taking the V-shaped groove 14 as a central line all the time, so that the conveying line of the steel pipe is consistent, and the adjustment is not needed even after the steel pipes with different sizes are replaced.

Example two

The plugging member in the first embodiment is replaced by a structure that the plugging member comprises a sealing cloth 30, the sealing cloth 30 is made of multilayer woven nylon cloth and is not easy to collapse when tightened, one end of the sealing cloth 30 is fixedly connected with one side of the top of a V-shaped groove 14, the other side of the top of the V-shaped groove 14 is provided with a first cloth groove 31, the first cloth groove 31 is obliquely arranged and extends to the bottom surface of a feeding table 1, the sealing cloth 30 penetrates through the first cloth groove 31, the other end of the sealing cloth 30 is fixedly connected with the periphery of a cloth roller 32, the cloth roller 32 is rotatably installed at the bottom of the feeding table 1 in a damping mode, the sealing cloth 30 is wound around the cloth roller 32 for a plurality of weeks, the bottom of the V-shaped groove 14 is provided with a second cloth groove 33, the second cloth groove 33 is vertically arranged and also extends to the bottom surface of the feeding table 1, a heavy hammer is penetrated through the second cloth groove 33, the upper end of the cloth 34 is fixedly connected with the sealing cloth 30, the lower end of the cloth 34 is fixedly connected with a 35, and the cloth roller 32 is coaxially provided with a third gear, the third gear is not shown in the figure, the meshing mode of the third gear and the flexible rack is the same as that of the first embodiment, and only two groups of flexible racks are arranged on the inner ring of the first transmission belt 8, so that intermittent alternate forward and reverse rotation of the cloth roller 32 is realized, when the cloth roller 32 draws the sealing cloth 30, the tightened sealing cloth is flush with the top surface of the feeding table 1, a steel pipe can pass through the sealing cloth, when the cloth roller 32 loosens the sealing cloth 30 wound on the sealing cloth, the sealing cloth 30 above the V-shaped groove 14 can be bent downwards under the action of the gravity of the heavy hammer 35, and the steel pipe can fall into the sealing cloth when passing through the sealing cloth; the structure is more simplified, but the steel pipe with larger weight is not suitable, and the preferable weight interval is 8-10 kg.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a clamping mobile device for nonrust steel pipe peeler, includes pay-off platform (1), and top surface one side of pay-off platform (1) is equipped with blanking slope (2), its characterized in that: a through groove (3) is formed in the blanking slope (2), the length direction of the through groove (3) is in accordance with the length direction of the blanking slope (2), a rotating shaft (4) is arranged in the through groove (3), a plurality of strip plates (5) are arranged on the periphery of the rotating shaft (4), a first driving wheel (6) is fixedly installed at one end of the rotating shaft (4) after penetrating through the through groove (3), at least two second driving wheels (7) are arranged below the feeding table (1), one of the second driving wheels (7) is connected with a power device, all the second driving wheels (7) are connected through a first driving belt (8), a third driving wheel (9) is coaxially installed on the second driving wheel (7) below the first driving wheel (6), the third driving wheel (9) is connected with the first driving wheel (6) through a second driving belt (10), a plurality of flexible racks are fixedly installed on the inner ring of the first driving belt (8), a plurality of V-shaped grooves (14) are formed in the top surface of the feeding table (1), except one V-shaped groove (14) far away from the blanking slope (2), the other V-shaped grooves (14) are internally provided with plugging pieces, the plugging pieces drive the plugging pieces to be unfolded or folded through flexible racks, and when the plugging pieces are unfolded, the tops of the V-shaped grooves (14) are closed.

2. The clamping and moving device for a stainless steel tube rotary cutting machine according to claim 1, wherein: the plugging piece comprises two hinged movable plates (15), sliding grooves (16) are formed in the tops of two sides of a V-shaped groove (14) respectively, sliding blocks (17) in sliding fit with the sliding grooves are arranged in the sliding grooves (16), the opposite sides of the two movable plates (15) are connected with the corresponding sliding blocks (17) in a rotating mode respectively, through holes (18) are vertically formed in the bottoms of the V-shaped grooves (14), ejector rods (19) are arranged in the through holes (18) respectively, the hinged positions of the two movable plates (15) are connected with the upper ends of the corresponding ejector rods (19), the lower ends of the ejector rods (19) are hinged with the upper ends of push-pull rods (20), the lower ends of the push-pull rods (20) are connected with the eccentric positions of discs (21) in a rotating mode, the discs (21) are connected with first gears (22) in a coaxial mode, the first gears (22) are located in a first transmission belt (8), and adjacent first gears (22) are arranged in a staggered mode.

3. The clamping moving device for the stainless steel pipe rotary cutting machine according to claim 2, wherein: both sides of the movable plate (15) are of wedge-shaped structures.

4. The clamping moving device for the stainless steel pipe rotary cutting machine according to claim 1, wherein: and a plurality of supporting legs (23) are fixedly arranged on two sides of the bottom surface of the feeding table (1).

5. The clamping moving device for the stainless steel pipe rotary cutting machine according to claim 1, wherein: the blanking slope (2) is composed of an L-shaped plate (2-1) and an inclined plate (2-2), and the through groove (3) is positioned on the inclined plate (2-2).

6. The clamping moving device for the stainless steel pipe rotary cutting machine according to claim 1, wherein: one end of V-arrangement groove (14) all be equipped with pipe conveying mechanism, pipe conveying mechanism includes two removal seats (24), two removal seats (24) are located the both sides of V-arrangement groove (14) respectively, all rotate on every removal seat (24) and install two at least running rollers (25), one of them removal seat (24) are connected with telescopic link (26), one of them removes and sets up the sprocket structure on seat (24), the sprocket structure is used for making corresponding running roller (25) rotate, the opposite side of two removal seats (24) sets up second rack (27) respectively, two crisscross settings of second rack (27) just mesh a second gear (28) jointly.