CN110758985A

CN110758985A - Multi-roller belt pressing device of large-inclination-angle large belt conveyor

Info

Publication number: CN110758985A
Application number: CN201911141298.7A
Authority: CN
Inventors: 刘炽
Original assignee: Shenyang Zhongmei Design & Research Institute Co Ltd
Current assignee: Shenyang Zhongmei Design & Research Institute Co Ltd
Priority date: 2019-11-20
Filing date: 2019-11-20
Publication date: 2020-02-07
Anticipated expiration: 2039-11-20

Abstract

A multi-roller belt pressing device of a large-scale belt conveyor with a large inclination angle belongs to the technical field of belt conveyors and overcomes the problems that a pressing roller and a linear bracket in the prior art are hard connected, the space for bearing materials between the pressing roller and the belt pressing is small, the pressing points are few, the contact area of an effective belt pressing is small, and the belt pressing device is not suitable for high-speed conveying of the materials with heavy load, wide width and large single particles, and is characterized in that a first frame in an eight-shaped shape is respectively hinged at the left end and the right end of a cross beam, a second frame in a rectangular shape is respectively hinged at the front end and the rear end of each first frame in an eight-shaped shape, 2 square third frames are respectively hinged at the front end and the rear end of each second frame, and the pressing roller is arranged in each third frame through a roller shaft, and has the advantages of more freedom degrees of the pressing roller, more pressing points and large contact area of the effective belt pressing, and is suitable for high-speed conveying of the, the demand of crossing under hillside, culvert and the tunnel occasion transported substance material has been satisfied.

Description

Multi-roller belt pressing device of large-inclination-angle large belt conveyor

Technical Field

The invention belongs to the technical field of belt conveyors, and particularly relates to a multi-roller belt pressing device of a large-scale belt conveyor with a large inclination angle, which is applied to mine material conveying and can improve the conveying inclination angle of the large-scale conveyor.

Background

In the prior art, a common rubber belt conveyor is limited by a material dynamic stacking angle and a friction coefficient between materials and a rubber belt, a lifting inclination angle can only be about 18 degrees, a large belt conveyor applied to mine material conveying usually adopts a smaller inclination angle due to the process arrangement of a production system of a mine, and according to different material conveying characteristics, the maximum conveying lifting angle of the belt conveyor generally does not exceed 28 degrees, and for the belt conveyor for conveying general bulk materials, particularly for the belt conveyor with limited mass flow and geographical transportation environment conditions, such as needing to cross hillsides, culverts, tunnels and the like, the maximum conveying lifting angle is not more than 16 degrees, so that the arrangement of the rubber belt conveyor occupies a large area, has large engineering quantity and is long. However, when the inclination angle of the large belt conveyor is increased, the downward sliding force of the materials is increased during the transportation process, the material scattering phenomenon is serious, the operation speed of the large belt conveyor is slow, the transportation efficiency is reduced, and meanwhile, when the materials are scattered, the equipment abrasion and aging are aggravated, noise, dust and the like are generated, the environment of an operation site is damaged, and many potential safety hazards exist. In order to solve the problem, a large-angle belt conveyor is developed in some more industrially developed countries such as the united states, the uk, the japan and the like, and a plurality of units are developed in the country in the last 10 years. For example, a "mine material main lifting large-angle belt conveyor" published in 1989 by Shenyang coal mine design research institute is a paper, which mentions a sandwich belt conveyor, wherein the lower part is provided with a bearing adhesive tape, the upper part is provided with a covering adhesive tape, and the normal pressing force required on the covering adhesive tape is solved by a mechanical pressing roller mechanism, pressing rollers of the pressing roller mechanism and carrier rollers for bearing the adhesive tape are arranged at intervals, one pressing roller mechanism is provided with two groups of pressing rollers, the two groups of pressing rollers can rotate around the center of a support, the whole pressing roller mechanism can rotate around the center of a hanging bracket of the pressing roller mechanism, each group of pressing rollers consists of four pressing rollers, each pressing roller can rotate around the center of a respective pin shaft, and the two pressing rollers on the two sides can rotate mutually. However, as shown in the front view and the left view of fig. 8 of the attached drawings, two sets of compression rollers of the compression roller mechanism of the mine material main lifting large-angle belt conveyor are directly and rigidly connected with the bracket, and the bracket is in a linear structure, so that the two sets of compression rollers of the compression roller mechanism can only rotate around the center of the bracket, each compression roller can only rotate around the center of a respective pin shaft and cannot swing along with the increase or decrease of materials, but during the actual lifting operation of the conveyor, the edges of the bearing adhesive tape and the covering adhesive tape cannot completely and tightly fit with each other, and have certain fluctuation, in order to ensure the normal pressure required on the edges of the covering adhesive tape, the compression rollers can not only rotate around the centers of the respective pin shafts, but also can swing along with the increase or decrease of materials, and the structure of the compression roller mechanism cannot meet the requirement, especially under the condition of wide heavy load and large single material particles, the structure of the press roller mechanism can not ensure that the materials clamped between the bearing adhesive tape and the covering adhesive tape do not slide down.

The invention with the application number of CN201610624234.2 actually discloses a novel clamping belt type large-inclination-angle conveyor, which comprises a bearing adhesive tape machine and a covering adhesive tape machine which are arranged on a machine frame, wherein a covering adhesive tape is arranged on the covering adhesive tape machine, a bearing adhesive tape is arranged on the bearing adhesive tape machine, the covering adhesive tape and the bearing adhesive tape are tightly attached to one side for conveying materials, and the problem of material scattering is solved by the technical scheme, however, the bearing adhesive tape machine is arranged in a Z shape and is not suitable for material conveying of a long-distance large-scale belt conveyor, in particular, the belt pressing device adopts 4 groups of elastic press rollers, each 2 groups of elastic press rollers are connected through a first connecting rod, the middle part of the first connecting rod is hinged with a second connecting rod, the other end of the second connecting rod is connected to a spring, and because the structure of the invention bears 4 groups of elastic press rollers and are connected to a spring, and the spring support is always used, even if every two groups of elastic compression roller sets are hinged by the spring support, the four groups of elastic compression roller sets are connected to the spring support by the connecting rod after being hinged by the spring support, so that the four groups of elastic compression roller sets can be guaranteed to be pressed on the covering adhesive tape no matter how much material is, however, when the covering adhesive tape and the bearing adhesive tape run at high speed, the spring support is easy to incline backwards by the covering adhesive tape running at high speed due to the non-uniformity of the material clamped between the covering adhesive tape and the bearing adhesive tape and the lower strength of the spring support, and the four groups of elastic compression roller sets can not be guaranteed to be completely pressed on the covering adhesive tape all the time, so.

The utility model with the application number of CN201821009942.6 discloses a middle-roller-free belt pressing device and a belt pressing conveyor with the belt pressing device, wherein the middle-roller-free belt pressing device comprises a connecting frame, the lower part of the connecting frame is hinged with a balance beam through a first rotating shaft, and two ends of the balance beam are hinged with a belt pressing wheel set through a second rotating shaft; the pinch roller set comprises a frame hinged with the balance beam and rubber pinch rollers hinged to two ends of the frame through third rotating shafts; the second rotating shaft is vertical to the first rotating shaft, and the third rotating shaft is parallel to the second rotating shaft; the pivot of rubber pinch roller is perpendicular with the third pivot, is different from traditional belt pressing mechanism, and the utility model discloses a belt pressing device of scheme has saved middle bearing roller, only relies on the rubber pinch roller of both sides to carry the bearing belt and press the edge of area and clip, and the pressure of material is the elastic support power that is provided by the sticky tape recovery deformation between two areas. The utility model has the problems that, as shown in figure 1 and figure 2 of the attached drawings of the specification, the frame hinged with the balance beam in the pinch roller group is a rectangular frame, the space for bearing materials between the pinch roller group and the pinch roller is small when in use, the conveying resistance to the materials is large, and the pinch roller is not suitable for heavy-load wide-width and large-particle materials to pass through at high speed; when in use, the triangular bracket is connected with the conveyor frame body, the structure is single and thin, and the strength is lower.

Disclosure of Invention

The invention aims to solve the problems that the defects of the prior art are overcome, and the multi-roller belt pressing device of the large-inclination-angle large-scale belt conveyor can effectively prevent materials from scattering in the transportation process, can improve the strength of the belt pressing device and ensure that the materials run stably in the high-speed transportation process, so that a transmission belt of the large-scale belt conveyor is tightly combined with the materials on transmission equipment, and the material conveying efficiency can be improved under the conditions of wide heavy load and large single material particles.

The technical scheme includes that the swing arm comprises a swing arm body, a spring and a first frame, a cross beam is hinged to the right end of the swing arm body, a first longitudinal beam is hinged to the left end of the swing arm body, a second longitudinal beam is connected to the upper portion of an upper spring seat at the upper end of the spring through an adjusting screw, first frames are hinged to the left end and the right end of the cross beam body respectively, each first frame comprises a left arm and a right arm, the left arm and the right arm are connected through a first frame connecting plate, the left arm and the right arm of each first frame are in a splayed shape, a rectangular second frame is hinged to the front end and the rear end of each first frame respectively, 2 square third frames are hinged to the front end and the rear end of each rectangular second frame respectively, a compression roller is installed in each third frame through a roller shaft, and the first frame in the splayed shape and the second frame in the rectangular shape are formed by 1 and the second frame in the rectangular shape, The 4 square third frames and the 4 press rolls form 1 press roll group, the left end and the right end of the cross beam are provided with 2 press roll groups in total, and the multi-roll belt pressing device formed by the 8 multi-freedom-degree press rolls is formed.

The swing arm comprises a front side wall and a rear side wall, first longitudinal beam connecting holes are respectively processed at the left ends of the front side wall and the rear side wall, first pin lugs are welded on the front side wall and the rear side wall, first pin lug through holes are processed on the first pin lugs, lower spring seats are welded on the 2 first pin lugs, the cross beam comprises a cross beam body, a pipe end sealing plate and a supporting plate are respectively welded at the left end and the right end of the cross beam body, a connecting pipe is welded between the pipe end sealing plate and the supporting plate, a second pin lug is welded at the middle position of the cross beam body, a second pin lug through hole is processed on the second pin lug, the swing arm is hinged with a second pin lug through hole on the second pin lug of the cross beam through a second bolt through the first pin lug through hole on the first pin lug, a spring is installed in the lower spring seat of the swing arm, central connecting holes are respectively processed on the left arm and the right arm of the first frame, the left end and the right end of the cross beam are respectively hinged with the center connecting hole of the first frame in the shape of the Chinese character 'ba' through a third bolt for a connecting pipe.

When the device is used, the longitudinal beam connecting plate of the first longitudinal beam and the longitudinal beam connecting plate of the second longitudinal beam are fixedly arranged on a conveyor frame, and when materials are conveyed between the bearing rubber belt and the coating rubber belt, 8 press rollers are respectively pressed on 8 positions on the front side and the rear side of the coating rubber belt and float up and down along with the increase and decrease of the materials; when the materials are from no load to full load, the 8 press rolls float upwards along with the increase of the materials, the swing arms swing around the first bolts anticlockwise along with the increase of the materials, the upward floating range is limited by the springs, when the materials are gradually reduced, the 8 press rolls gradually float downwards along with the gradual reduction of the materials until no load, the swing arms swing around the first bolts clockwise along with the reduction of the materials, the downward floating range is also limited by the springs, in the process that the 8 press rolls float upwards or float downwards along with the increase and decrease of the materials, the 8 press rolls can respectively roll around the roll shafts and simultaneously swing around the fifth bolts along with the swing of the third frame around the fifth bolts in the square third frame to adapt to the increase and decrease of the materials, when the materials are gradually increased, each square third frame can swing around the fourth bolts in the rectangular second frame, and when the materials are continuously increased and increased, each rectangular second frame can swing around the third bolt in the splayed first frame.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention comprises a press roll group consisting of 1 splayed first frame, 2 rectangular second frames, 4 square third frames and 4 press rolls, wherein the left and right ends of a beam are provided with 2 press roll groups in total to form a multi-roll belt pressing device consisting of 8 multi-freedom press rolls, the 8 press rolls can respectively roll around a roll shaft in the upward floating or downward floating process along with the increase and decrease of materials and can simultaneously swing along with the swing of the third frames around a fifth bolt in the square third frames to adapt to the increase and decrease of the materials, so that the 8 press rolls are always and effectively pressed on a coating adhesive tape, when the materials are gradually increased and increased, each square third frame can swing around the fourth bolt in the rectangular second frames, and when the materials are continuously increased and increased, each rectangular second frame can swing around the third bolt in the splayed first frames, so the compression roller has a plurality of degrees of freedom, the pressure point is many, effective pressure area of contact is big, can be along with how much and automatic adaptation of material, be applicable to the material transport under the great condition of broad width heavy load and monomer material granule, the biggest broad width can reach 2000mm, the biggest monomer particulate matter diameter can reach 350mm, and can guarantee to hold between bearing rubber belt and cover rubber belt at broad width heavy load and the great condition material of monomer material granule and be unlikely to slide, can satisfy and cross the demand of carrying the material under hillside, culvert and the tunnel occasion.

(2) The first frame is a splayed frame, the second frame is a rectangular frame, the third frame is a square frame, and the frame is connected with the frame, so that the structural strength of the conveyor is improved, the conveyor is more suitable for conveying heavy-load wide materials, particularly the splayed first frame structure is large in material bearing space, beneficial for large-particle materials to pass at high speed and small in resistance, and is connected with the conveyor frame through the longitudinal beam connecting plates of the first longitudinal beam and the second longitudinal beam when the conveyor is used, and the structure is more stable.

Drawings

FIG. 1 is a schematic structural view of the present invention;

figure 2 is a top view of figure 1,

FIG. 3 is a cross-sectional view A-A of FIG. 1;

figure 4 is a front view of the swing arm of the present invention,

figure 5 is a top view of figure 4,

figure 6 is an enlarged cross-sectional view B-B of figure 4,

figure 7 is a front view of a beam according to the invention,

figure 8 is an enlarged cross-sectional view of C-C of figure 7,

figure 9 is an enlarged cross-sectional view of D-D of figure 7,

figure 10 is a left side view of the first frame of the present invention,

figure 11 is a top view of figure 10,

fig. 12 is a schematic view of the use state of the present invention.

In the figure:

1. a first longitudinal beam is arranged on the first side rail,

2. a swing arm is arranged on the base plate,

2-1, a front side wall, 2-2, a rear side wall, 2-3, a swing arm connecting plate,

2-4 first longitudinal beam connecting holes, 2-5 first pin lugs,

2-6, a first pin lug through hole, 2-7, a lower spring seat

3. The cross beam is provided with a plurality of cross beams,

3-1, a beam body, 3-2, a pipe end sealing plate,

3-3 connecting pipes, 3-4 supporting plates,

3-5, a second pin lug, 3-6, a through hole of the second pin lug,

4. a second longitudinal beam, 5 an upper spring seat, 6 a spring,

7. a press roll, 8, an adjusting screw,

9. a first frame, a second frame, a third frame,

9-1, a left arm, 9-2, a right arm, 9-3, a first frame connecting plate,

9-4 central connecting holes, 9-5 rear connecting holes, 9-6 front connecting holes,

10. a second frame, 11, a third frame, 12, a first bolt,

13. second bolt, 14, third bolt, 15, fourth bolt, 16, fifth bolt,

17. the adhesive tape is coated on the surface of the substrate,

18. material, 19 longitudinal beam connecting plates, 20 conveyor belt frames, 21 carrying adhesive tapes,

22, a roll shaft.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

As shown in the drawing, the present invention comprises a swing arm 2, a cross member 3 and a first frame 9;

as shown in fig. 4-6, the swing arm 2 comprises a front side wall 2-1 and a rear side wall 2-2 which are made of angle steel, the front side wall 2-1 and the rear side wall 2-2 are connected together through 2 swing arm connecting plates 2-3, first longitudinal beam connecting holes 2-4 are respectively processed at the left ends of the front side wall 2-1 and the rear side wall 2-2, 2 first pin lugs 2-5 are welded at the front and rear ends of the right ends of the front side wall 2-1 and the rear side wall 2-2, first pin lug through holes 2-6 are processed on the first pin lugs 2-5, and lower spring seats 2-7 are welded on the 2 first pin lugs 2-5;

as shown in fig. 7 to 9, the cross beam 3 includes a cross beam body 3-1 made of square steel, pipe end seal plates 3-2 and support plates 3-4 are respectively welded at the left and right ends of the cross beam body 3-1, a connecting pipe 3-3 is welded between the pipe end seal plates 3-2 and the support plates 3-4, a second pin lug 3-5 is welded at the middle position of the cross beam body 3-1, and a second pin lug through hole 3-6 is processed on the second pin lug 3-5;

as shown in fig. 10 and 11, the first frame 9 includes a left arm 9-1 and a right arm 9-2, the left arm 9-1 and the right arm 9-2 are connected by 2 first frame connecting plates 9-3 made of angle steel, the left arm 9-1 and the right arm 9-2 of the first frame 9 are both in a shape of a Chinese character 'ba', and a central connecting hole 9-4, a rear end connecting hole 9-5 and a front end connecting hole 9-6 are respectively processed on the left arm 9-1 and the right arm 9-2;

as shown in fig. 1 to 3, the left end of the swing arm 2 is hinged to a first longitudinal beam 1 through 2 first longitudinal beam connecting holes 2-4 by 2 first bolts 12, the right end of the swing arm 2 is hinged to a second pin lug through hole 3-6 on a second pin lug 3-5 of the cross beam 3 through a second bolt 13 through a first pin lug through hole 2-6 on the first pin lug 2-5, a spring 6 is installed in a lower spring seat 2-7 of the swing arm 2, an upper spring seat 5 is installed at the upper end of the spring 6, and the upper spring seat 5 is connected to a second longitudinal beam 4 through an adjusting screw 8; the left end and the right end of the beam 3 are respectively hinged with a central connecting hole 9-4 of a splayed first frame 9 through a connecting pipe 3-3 by a third bolt 14, a rectangular second frame 10 is hinged to the front end and the rear end of each first frame 9 in the shape of a Chinese character 'ba' respectively through a fourth bolt 15, a third frame 11 of 2 squares is hinged to the front and rear ends of each second frame 10 of a rectangular shape by a fifth bolt 16, a press roll 7 is installed in each third frame 11 through a roll shaft 22, 1 press roll group is formed by 1 splayed first frame 9, 2 rectangular second frames 10, 4 square third frames 11 and 4 press rolls 7, the left side and the right side of the second longitudinal beam 4 are provided with 2 compression roller groups in total to form a multi-roller belt pressing device consisting of 8 compression rollers, and longitudinal beam connecting plates 19 are welded on the first longitudinal beam 1 and the second longitudinal beam 4 respectively.

As shown in fig. 1-12, when the invention is used, the longitudinal beam connecting plate 19 of the first longitudinal beam 1 and the longitudinal beam connecting plate 19 of the second longitudinal beam 4 are fixedly arranged on the conveyor frame 20, when in operation, when materials 18 are conveyed between the bearing rubber belt 21 and the coating rubber belt 17, 8 press rollers 7 are respectively pressed on 8 positions at the front side and the rear side of the coating rubber belt 17 and float up and down along with the increase and decrease of the materials 18; when the material 18 is from no load to full load, 8 press rolls 7 float upwards along with the increase of the material 18, the swing arm 2 floats upwards along with the increase of the material by swinging around the first bolt 12 in a counterclockwise way, the upward floating range is limited by the spring 6, when the material 18 is gradually reduced, the 8 press rolls 7 float downwards gradually along with the gradual reduction of the material until no load, the swing arm 2 floats downwards along with the reduction of the material by swinging around the first bolt 12 in a clockwise way, the downward floating range is also limited by the spring 6, in the process that the 8 press rolls 7 float upwards or float downwards along with the increase and the decrease of the material 18, the 8 press rolls 7 can roll around the roll shafts 22 respectively and simultaneously swing around the fifth bolt 16 along with the third frame 11 in the square third frame 11 to adapt to the increase and the decrease of the material 18, so that the 8 press rolls 7 are always effectively pressed on the coating adhesive tape 17, when the material increases gradually and increases, every square third frame 11 can swing around fourth bolt 15 in rectangular second frame 10, when the material continues to increase and increases, every rectangular second frame 10 can swing around third bolt 14 in eight shape first frame 9, because eight shape first frame 9 existing great width and have great space with cladding sticky tape 17 between, so can adapt to the transport of broad width large granule heavy load material, maximum width can reach 2000mm, the biggest monomer particulate matter diameter can reach 350mm to can guarantee that the material does not spill under high-speed transport state.

Claims

1. The multi-roller belt pressing device of the large-scale belt conveyor with the large inclination angle comprises a swing arm (2), a spring (6) and a first frame (9), wherein the right end of the swing arm (2) is hinged with a cross beam (3), and is characterized in that the left end of the swing arm (2) is hinged with a first longitudinal beam (1), a second longitudinal beam (4) is connected to the upper surface of an upper spring seat (5) at the upper end of the spring (6) through an adjusting screw (8), the left end and the right end of the cross beam (3) are respectively hinged with the first frame (9), the first frame (9) comprises a left arm (9-1) and a right arm (9-2), the left arm (9-1) and the right arm (9-2) are connected through 2 first frame connecting plates (9-3), and the left arm (9-1) and the right arm (9-2) of the first frame (9) are in a splayed shape, the front end and the rear end of each first frame (9) in the shape of the Chinese character 'ba' are respectively hinged with a second frame (10) in the shape of the Chinese character 'ba', the front end and the rear end of each second frame (10) in the shape of the Chinese character 'ba' are respectively hinged with a third frame (11) in the shape of 2 squares, a press roller (7) is arranged in each third frame (11) through a roller shaft (22), 1 press roller group is formed by the first frames (9) in the shape of the Chinese character 'ba', the second frames (10) in the shape of the Chinese character 'ba', the third frames (11) in the shape of 4 squares and 4 press rollers (7), the left end and the right end of the cross beam (3) are provided with 2 press roller groups in total, and a multi-roller press belt device formed by 8 press rollers with multiple degrees of freedom is formed.

2. The multi-roller belt pressing device of a large-scale belt conveyor with a large inclination angle according to claim 1, wherein the swing arm (2) comprises a front side wall (2-1) and a rear side wall (2-2), a first longitudinal beam connecting hole (2-4) is respectively processed at the left ends of the front side wall (2-1) and the rear side wall (2-2), a first pin lug (2-5) is welded on the front side wall (2-1)) and the rear side wall (2-2), a first pin lug through hole (2-6) is processed on the first pin lug (2-5), a lower spring seat (2-7) is welded on the upper surface of the 2 first pin lugs (2-5), the cross beam (3) comprises a cross beam body (3-1), a sealing plate (3-2) and a pipe end supporting plate (3-4) are respectively welded at the left end and the right end of the cross beam body (3-1), a connecting pipe (3-3) is welded between a pipe end sealing plate (3-2) and a supporting plate (3-4), a second pin lug (3-5) is welded in the middle of a beam body (3-1), a second pin lug through hole (3-6) is processed on the second pin lug (3-5), the swing arm (2) is hinged with the second pin lug through hole (3-6) on the second pin lug (3-5) of the beam (3) through a second bolt (13) through the first pin lug through hole (2-6) on the first pin lug (2-5), a spring (6) is installed in a lower spring seat (2-7) of the swing arm (2), and central connecting holes (9-4) are respectively processed on a left arm (9-1) and a right arm (9-2) of a first frame (9), the left end and the right end of the cross beam (3) are respectively hinged with a central connecting hole (9-4) of the splayed first frame (9) through a connecting pipe (3-3) by a third bolt (14).

3. The multi-roller belt pressing device of the large-scale belt conveyor with the large inclination angle according to the claim 1 or 2 is characterized in that when in use, the device is fixedly arranged on a conveyor frame (20) through a longitudinal beam connecting plate (19) of a first longitudinal beam (1) and a second longitudinal beam (4), when materials (18) are conveyed between a bearing rubber belt (21) and a coating rubber belt (17), 8 pressing rollers (7) respectively press 8 positions on the front side and the rear side of the coating rubber belt (17) to float up and down along with the increase and the decrease of the materials (18); when the material (18) is from no load to full load, 8 press rolls (7) float upwards along with the increase of the material (18), the swing arm (2) swings anticlockwise around the first bolt (12) along with the increase of the material, the upward floating range is limited by the spring (6), when the material (18) is gradually reduced, the 8 press rolls (7) float downwards gradually along with the gradual reduction of the material until no load, the swing arm (2) swings clockwise around the first bolt (12) along with the reduction of the material, the downward floating range is also limited by the spring (6), in the process that the 8 press rolls (7) float upwards or float downwards along with the increase and decrease of the material (18), the 8 press rolls (7) can roll around the roll shafts (22) respectively and simultaneously swing around the fifth bolt (16) along with the third frame (11)) in the square third frame (11)) to adapt to the increase and decrease of the material (18), when the materials are increased and increased gradually, each square third frame (11) can swing around the fourth bolt (15) in the rectangular second frame (10), and when the materials are increased and increased continuously, each rectangular second frame (10) can swing around the third bolt (14) in the splayed first frame (9).