Automatic adhesive dispensing and edge covering equipment for magnetic steel
By designing an automated magnetic steel dispensing edge wrapping equipment, the problems of poor quality stability and low working efficiency of magnetic steel caused by manual operation are solved, and higher quality stability and efficiency are achieved.
Patent Information
- Application Number
- CN202411788529.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2025-03-14
AI Technical Summary
Due to the poor consistency of manual operation, the existing magnetic steel has poor quality stability and low working efficiency.
An automatic dispensing and edging equipment for magnetic steel is designed, including a loading conveyor belt, a dispensing structure, an edge-mounting and edging device and a feed conveyor belt, and the automatic conveying and edging operation of magnetic steel is achieved using guide rails, frames, telescopic rods and driving equipment.
Through automated dispensing and edge-covering operations, manual errors are effectively reduced and the quality stability and working efficiency of magnets are improved.
Smart Images

Figure CN119608499A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of magnet processing, and in particular relates to an automatic glue dispensing and edging device for magnetic steel. Background Art
[0002] Due to its excellent magnetic properties, cost-effectiveness and abundant resource reserves, NdFeB magnets are used in many industries including modern home appliances, industrial motors, microelectronic motors, new energy vehicles, etc.
[0003] During the assembly process of NdFeB magnets, in order to prevent the surface of the magnets from being worn during the assembly process, the magnets need to be bonded and edged. Currently, most bonding methods are to manually dispense glue on the edge, then bond the edge to the magnet, and then manually press it. Due to the poor consistency of manual operation, the magnet quality stability is poor and the work efficiency is low. Summary of the invention
[0004] In view of this, the present invention discloses an automatic magnetic steel gluing and edging equipment, which aims to solve the problems of poor magnetic steel quality stability and low work efficiency due to poor consistency of manual operation in existing magnetic steel edging.
[0005] In order to achieve the above object, the present invention provides the following technical solutions:
[0006] A magnetic steel automatic glue dispensing and edging equipment, comprising a feeding conveyor belt, a glue dispensing structure for spraying glue on the magnetic steel, an edging installation and clamping device, and a feeding conveyor belt, which are arranged in sequence; a guide rail parallel to the feeding conveyor belt is arranged beside the glue dispensing structure and the edging installation and clamping device; a frame is slidably arranged on the guide rail; a first driving device for driving the frame to slide is arranged on the frame; a first telescopic rod is connected to the top of the frame in a horizontal sliding direction perpendicular to the guide rail; a second driving device for driving the first telescopic rod to slide is arranged on the frame Equipment, the end of the first telescopic rod is coaxially connected to a mounting seat, the mounting seat is provided with a magnetic vacuum suction cup for grabbing the magnetic steel, and the first telescopic rod is provided with a first rotating device for driving the mounting seat to rotate; the edging installation and clamping device includes a storage plate for placing the edging strips, brackets are provided on both sides of the storage plate, and a rotating shaft parallel to the feeding conveyor belt is rotatably connected between adjacent brackets, a second rotating device for driving the rotating shaft to rotate is provided on the bracket, and a number of adsorption and clamping structures for adsorbing the edging strips are provided on the rotating shaft.
[0007] After the edging strip on the material storage plate is adsorbed and fixed by the adsorption and clamping structure, the rotating shaft is driven to rotate by the second rotating device, thereby driving the edging strip to rotate to a horizontal level; the first telescopic rod is then extended to drive the magnetic steel vacuum suction cup to move downward, and the un-edged magnetic steel on the feeding conveyor belt is adsorbed and fixed by the magnetic steel vacuum suction cup, and then the first telescopic rod is contracted to drive the magnetic steel to move upward to a height parallel to the device's dispensing structure, and then the frame is driven by the first driving device to move the magnetic steel through the dispensing structure and the edging installation and clamping device in sequence; in this process, the first telescopic rod is driven to slide by the second driving device to adjust the position of the magnetic steel, so that the magnetic steel contacts the dispensing structure and the edging installation and clamping device respectively when passing through them, so as to facilitate the dispensing operation of the magnetic steel and the installation and clamping of the edging strip; when the magnetic steel after the edging is completed moves to the feeding conveyor belt, the first telescopic rod is extended to place the magnetic steel on the feeding conveyor belt, and then the frame is reset.
[0008] The beneficial effect of this solution is that the magnetic steel is transported from the loading conveyor belt to the feeding conveyor belt through the frame and other structures, and the gluing and hemming operations are completed in sequence during the transportation process; the whole process can effectively reduce the errors caused by manual labor, improve the quality stability of the magnetic steel, and improve work efficiency.
[0009] Furthermore, the adsorption and clamping structure includes a vertically arranged support roller and a U-shaped support for clamping the support roller, connecting rods rotatably connected to the support are coaxially fixed at both ends of the support roller, a third rotating device for driving the corresponding connecting rod to rotate is provided on the support, and a second telescopic rod is connected and fixed between the support and the rotating shaft; two symmetrically arranged clamping rollers are coaxially slidingly sleeved on the support roller, and a pushing rod for pushing the clamping roller to slide is provided between the adjacent ends of the clamping roller and the support roller; a groove is horizontally opened in the support roller, a through hole is opened at the end of the groove and penetrates the side wall of the support roller, and a vacuum suction cup for the edging strip is provided in the through hole.
[0010] In the present scheme, according to the size of the edging strip, the pressing roller is driven to move by the extension and contraction of the push rod to expose the through hole, and at the same time, the spacing between the pressing rollers fits the size of the edging strip; during the edging operation, the second rotating device drives the rotating shaft to rotate forwardly, so that the second telescopic rod is downward, keeping the through hole facing the edging strip on the material storage plate; then the second telescopic rod is extended to make the through hole on the support roller contact with the edging strip, at this time, the edging strip is adsorbed and fixed by the vacuum suction cup of the edging strip, and then the second telescopic rod is shortened to drive the edging strip to separate from the material storage plate; at this time, the second rotating device drives the rotating shaft to rotate in the opposite direction, driving the edging strip to rotate to the horizontal; when the magnetic steel moves to be flush with the edging strip, the second telescopic rod is extended to make the support roller drive the edging strip to fit on the surface of the magnetic steel, and then the negative pressure state of the vacuum suction cup of the corresponding edging strip is destroyed, so that the vacuum suction cup of the edging strip is separated from the edging strip; then the first driving device and the frame and other structures drive the magnetic steel to reciprocate, and the support roller is used to press and fix the edging strip. During this process, the clamping rollers at both ends of the support roller limit the edge strip to prevent the edge strip from deviating and causing an increase in error. In addition, during the clamping process of the U-shaped edge strip in the longitudinal section, the push rod is used to cause the clamping roller to apply pressure to the upper and lower ends of the edge strip to improve the stability of the two ends of the edge strip and the surface of the magnetic steel.
[0011] Furthermore, the groove and the through hole are not coaxial, and a connecting seat is connected to the side of the groove away from the through hole, and a fourth rotating device for driving the connecting seat to rotate is arranged on the side wall of the groove, and third telescopic rods parallel to the groove are fixed at both ends of the connecting seat, the vacuum suction cup of the edging strip is arranged at one of the output ends of the third telescopic rod, and a baffle for closing the through hole is fixed on the other end of the third telescopic rod, and the baffle is arc-shaped.
[0012] In this solution, when it is necessary to adsorb the edging strip, the fourth rotating device is used to drive the connecting seat to rotate forward so that the vacuum suction cup of the edging strip is facing the through hole, and the corresponding third telescopic rod is controlled to extend to drive the vacuum suction cup of the edging strip to extend out of the through hole; when the edging strip is to be pressed, the corresponding third telescopic rod is controlled to drive the vacuum suction cup of the edging strip to retract into the through hole, and then the fourth rotating device is used to drive the connecting seat to rotate reversely so that the baffle is facing the through hole, and the corresponding third telescopic rod is controlled to extend to drive the baffle to close the through hole, thereby avoiding uneven force on the edging strip during the pressing process.
[0013] Furthermore, coaxial circular grooves are provided at the facing ends of adjacent pressure rollers, fixed rods are hinged on the circumferential sides of the circular grooves, and coaxial sliding sleeves are provided on the movable ends of the fixed rods with pressing rollers, elastic support members are provided between the pressing rollers and the fixed rods, and fourth telescopic rods are hinged on the side walls of the fixed rods away from the supporting rollers, and the ends of the fourth telescopic rods are hinged to the end faces of the circular grooves.
[0014] In this solution, when the upper and lower end surfaces of the magnetic steel are inclined, the fourth telescopic rod is extended to push the fixed rod to swing toward the support roller, and the pressing roller is kept close to the support roller under the action of the elastic support member. At this time, the clamping roller moves under the action of the pushing rod, and the inclined pressing roller is used to press and fix the edging strip on the inclined end surface of the magnetic steel.
[0015] Furthermore, the dispensing device includes a liquid storage tank and a base, the side wall of the base is rotatably connected with an installation shaft horizontally and perpendicular to the base, the base is provided with a fifth rotating device for driving the installation shaft to rotate, the installation shaft is provided with a dispensing nozzle, and the liquid storage tank is provided with a pump body that transports the colloid to the dispensing nozzle.
[0016] Furthermore, the ends of the pressing rollers are each provided with a rubber cushion layer.
[0017] Furthermore, the end of the pressing roller is arc-shaped.
[0018] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:
[0020] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;
[0021] Figure 2 A longitudinal cross-sectional view of the adsorption and compression structure in an embodiment of the present invention;
[0022] Figure 3 for Figure 2 The enlarged schematic diagram of point A in the middle;
[0023] Figure 4 for Figure 1 The enlarged schematic diagram of point B in the middle;
[0024] Figure 5 for Figure 1 Enlarged schematic diagram of point C in the middle.
[0025] The markings in the accompanying drawings are as follows: loading conveyor belt 1, feeding conveyor belt 2, guide rail 3, frame 4, first telescopic rod 5, mounting seat 6, magnetic steel vacuum suction cup 7, storage plate 8, bracket 9, rotating shaft 10, supporting roller 11, support 12, connecting rod 13, second telescopic rod 14, clamping roller 15, pushing rod 16, edging strip vacuum suction cup 17, connecting seat 18, third telescopic rod 19, baffle 20, fixing rod 21, pressing roller 22, elastic support 23, fourth telescopic rod 24, liquid storage tank 25, mounting shaft 26, dispensing nozzle 27, base 28. DETAILED DESCRIPTION
[0026] like Figures 1 to 5 As shown:
[0027] A magnetic steel automatic glue dispensing and edging equipment, comprising a feeding conveyor belt 1, a glue dispensing structure for spraying glue on the magnetic steel, an edging installation and clamping device, and a feeding conveyor belt 2 which are arranged in sequence, a guide rail 3 parallel to the feeding conveyor belt 1 is arranged beside the glue dispensing structure and the edging installation and clamping device, a frame 4 is slidably arranged on the guide rail 3, a first driving device for driving the frame 4 to slide is arranged on the frame 4, a first telescopic rod 5 vertically downward is connected to the top end of the frame 4 in a horizontal sliding direction perpendicular to the guide rail 3, and a second driving device for driving the first telescopic rod 5 to slide is arranged on the frame 4, The end of the first telescopic rod 5 is coaxially rotatably connected to a mounting seat 6, and a magnetic vacuum suction cup 7 for grabbing the magnetic steel is provided on the mounting seat 6. The first telescopic rod 5 is provided with a first rotating device for driving the mounting seat 6 to rotate; the edging installation and clamping device includes a storage plate 8 for placing the edging strips, and brackets 9 are provided on both sides of the storage plate 8. A rotating shaft 10 parallel to the feeding conveyor belt 1 is rotatably connected between adjacent brackets 9, and a second rotating device for driving the rotating shaft 10 to rotate is provided on the bracket 9, and a plurality of adsorption and clamping structures for adsorbing the edging strips are provided on the rotating shaft 10.
[0028] After the edging strip on the material storage plate 8 is adsorbed and fixed by the adsorption and clamping structure, the rotating shaft 10 is driven to rotate by the second rotating device, thereby driving the edging strip to rotate to the horizontal; then the first telescopic rod 5 is extended to drive the magnetic steel vacuum suction cup 7 to move downward, and the un-edged magnetic steel on the feeding conveyor belt 1 is adsorbed and fixed by the magnetic steel vacuum suction cup 7, and then the first telescopic rod 5 is contracted to drive the magnetic steel to move upward to a height parallel to the device's dispensing structure, and then the frame 4 is driven by the first driving device to move the magnetic steel through the dispensing structure and the edging installation and clamping device in sequence; in this process, the first telescopic rod 5 is driven to slide by the second driving device to adjust the position of the magnetic steel, so that the magnetic steel contacts the dispensing structure and the edging installation and clamping device respectively when passing through the dispensing structure and the edging installation and clamping device, so as to facilitate the dispensing operation on the magnetic steel and the installation and clamping of the edging strip.
[0029] When one side of the magnetic steel is finished with edging, the mounting seat 6 is driven to rotate by the first rotating device, driving the magnetic steel to rotate so that the unedged side wall of the magnetic steel faces the edging installation clamping device, and then the frame 4 is driven by the first driving device to drive the magnetic steel to move to the initial position and repeat the above operation until the edging operation of the side walls of the magnetic steel is completed; when the magnetic steel after edging is moved to the feeding conveyor belt 2, the first telescopic rod 5 is extended to place the magnetic steel on the feeding conveyor belt 2, and then the frame 4 is reset.
[0030] The beneficial effect of this solution is that the magnetic steel is transported from the loading conveyor belt 1 to the feeding conveyor belt 2 through the frame 4 and other structures, and the gluing and hemming operations are completed in sequence during the transportation process; the whole process can effectively reduce the errors caused by manual labor, improve the quality stability of the magnetic steel, and improve work efficiency.
[0031] In this embodiment, the adsorption and clamping structure includes a vertically arranged support roller 11 and a U-shaped support 12 for clamping the support roller 11, and connecting rods 13 rotatably connected to the support 12 are coaxially fixed at both ends of the support roller 11, and a third rotating device for driving the corresponding connecting rod 13 to rotate is arranged on the support 12, and a second telescopic rod 14 is connected and fixed between the support 12 and the rotating shaft 10; two symmetrically arranged clamping rollers 15 are coaxially slidingly sleeved on the support roller 11, and a pushing rod 16 for pushing the clamping roller 15 to slide is arranged between the adjacent ends of the clamping roller 15 and the support roller 11; a groove is horizontally opened in the support roller 11, and a through hole is opened at the end of the groove and penetrates the side wall of the support roller 11, and a vacuum suction cup 17 for edging strips is arranged in the through hole.
[0032] In this solution, according to the size of the hemming strip, the pressing roller 15 is moved by the extension and retraction of the push rod 16 to expose the through hole, and at the same time, the spacing between the pressing rollers 15 fits the size of the hemming strip; during the hemming operation, the second rotating device drives the rotating shaft 10 to rotate forward, so that the second telescopic rod 14 is downward, and the through hole is kept facing the hemming strip on the storage plate 8; then the second telescopic rod 14 is extended to make the through hole on the support roller 11 contact with the hemming strip, and at this time, the hemming strip is adsorbed and fixed by the vacuum suction cup 17 of the hemming strip, and then the second telescopic rod 1 4 is shortened, driving the edging strip to separate from the material storage plate 8; at this time, the second rotating device drives the rotating shaft 10 to rotate in the opposite direction, driving the edging strip to rotate to the horizontal; when the magnetic steel moves to be flush with the edging strip, the second telescopic rod 14 is extended, so that the support roller 11 drives the edging strip to fit on the surface of the magnetic steel, and then the negative pressure state of the vacuum suction cup 17 of the corresponding edging strip is destroyed, so that the vacuum suction cup 17 of the edging strip is separated from the edging strip; then the first driving device and the frame 4 and other structures drive the magnetic steel to reciprocate, and the support roller 11 is used to press and fix the edging strip. In this process, the pressing rollers 15 at both ends of the support roller 11 limit the edging strip to prevent the edging strip from deviating, resulting in an increase in error; in addition, during the pressing process of the edging strip with a U-shaped longitudinal section, the push rod 16 is used to prompt the pressing roller 15 to apply pressure to the upper and lower ends of the edging strip to improve the stability of the two ends of the edging strip and the surface of the magnetic steel.
[0033] At this time, by utilizing the extension and retraction of the second telescopic rod 14, when the side wall of the magnetic steel is arc-shaped, the support roller 11 can also be closely attached to the edge strip, so that the edge strip and the magnetic steel are closely bonded.
[0034] In this embodiment, the groove and the through hole are not coaxial, and a connecting seat 18 is connected to the side of the groove away from the through hole, and a fourth rotating device for driving the connecting seat 18 to rotate is provided on the side wall of the groove, and third telescopic rods 19 parallel to the groove are fixed at both ends of the connecting seat 18, and the edging strip vacuum suction cup 17 is arranged at one of the output ends of the third telescopic rods 19, and a baffle 20 for closing the through hole is fixed on the other end of the third telescopic rod 19, and the baffle 20 is arc-shaped.
[0035] In this solution, when it is necessary to adsorb the edging strip, the fourth rotating device is used to drive the connecting seat 18 to rotate forward so that the edging strip vacuum suction cup 17 is facing the through hole, and the corresponding third telescopic rod 19 is controlled to extend to drive the edging strip vacuum suction cup 17 to extend out of the through hole; when the edging strip is to be pressed, the corresponding third telescopic rod 19 is controlled to drive the edging strip vacuum suction cup 17 to retract into the through hole, and then the fourth rotating device is used to drive the connecting seat 18 to rotate reversely so that the baffle 20 is facing the through hole, and the corresponding third telescopic rod 19 is controlled to extend to drive the baffle 20 to close the through hole, thereby avoiding uneven force on the edging strip during the pressing process.
[0036] In this embodiment, the facing ends of adjacent pressure rollers 15 are provided with coaxial circular grooves, and the circumferential sides of the circular grooves are hinged with fixed rods 21. The movable ends of the fixed rods 21 are coaxially slidably sleeved with pressing rollers 22. Elastic support members 23 are provided between the pressing rollers 22 and the fixed rods 21. The side walls of the fixed rods 21 away from the supporting rollers 11 are hinged with fourth telescopic rods 24, and the ends of the fourth telescopic rods 24 are hinged to the end faces of the circular grooves.
[0037] In this solution, when the upper and lower end surfaces of the magnetic steel are inclined, the fourth telescopic rod 24 is extended to push the fixed rod 21 to swing toward the support roller 11, and the pressing roller 22 is kept close to the support roller 11 under the action of the elastic support member 23. At this time, the clamping roller 15 moves under the action of the pushing rod 16, and the inclined pressing roller 22 is used to press and fix the edging strip on the inclined end surface of the magnetic steel.
[0038] In this embodiment, the dispensing structure includes a liquid storage tank 25 and a base 28. The side wall of the base 28 is rotatably connected to a mounting shaft 26 that is horizontally and perpendicular to the base 28. The base 28 is provided with a fifth rotating device for driving the mounting shaft 26 to rotate. The mounting shaft 26 is provided with a dispensing nozzle 27. The liquid storage tank 25 is provided with a pump body for conveying colloid to the dispensing nozzle 27 (which is a conventional technical means and is not drawn in the figure).
[0039] The fifth rotating device drives the mounting shaft 26 to rotate, so that the angle of the glue dispensing nozzle 27 can be adjusted to adapt to the glue dispensing operation on the surface of magnetic steel with different specifications.
[0040] In this embodiment, the ends of the pressing rollers 15 are provided with rubber cushion layers (which are conventional technical means and therefore not shown in the figure).
[0041] The rubber cushion layer is provided to reduce the damage of the edge strip caused by the pressing roller 15 during the pressing process.
[0042] In this embodiment, the end of the pressing roller 22 is arc-shaped.
[0043] The end of the pressing roller 22 is arc-shaped, which can effectively reduce the wear of the pressing roller 22 on the supporting roller 11 .
[0044] The driving device and the rotating device in this embodiment are both driven by motors. The telescopic rod and the pushing rod 16 in this embodiment are both electric telescopic rods, which are conventional technical means and are not described in detail.
[0045] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.
Claims
1. A magnetic steel automatic glue dispensing and hemming equipment, characterized by: The invention comprises a feeding conveyor belt, a glue dispensing structure for spraying colloid onto the magnetic steel, an edging installation and clamping device and a feeding conveyor belt which are arranged in sequence, a guide rail parallel to the feeding conveyor belt is arranged beside the glue dispensing structure and the edging installation and clamping device, a frame is slidably arranged on the guide rail, a first driving device for driving the sliding of the frame is arranged on the frame, a first telescopic rod is horizontally slidably connected to the top of the frame along a direction perpendicular to the guide rail with a first telescopic rod vertically downward, a second driving device for driving the first telescopic rod to slide is arranged on the frame, a mounting seat is coaxially rotatably connected to the end of the first telescopic rod, a magnetic steel vacuum suction cup for grabbing the magnetic steel is arranged on the mounting seat, and a first rotating device for driving the mounting seat to rotate is arranged on the first telescopic rod; the edging installation and clamping device comprises a material storage plate for placing the edging strips, brackets are arranged on both sides of the material storage plate, a rotating shaft parallel to the feeding conveyor belt is rotatably connected between adjacent brackets, a second rotating device for driving the rotating shaft to rotate is arranged on the bracket, and a number of adsorption and clamping structures for adsorbing the edging strips are arranged on the rotating shaft.
2. The magnetic steel automatic glue dispensing and edge wrapping equipment according to claim 1 is characterized by: The adsorption and clamping structure includes a vertically arranged support roller and a U-shaped support for clamping the support roller, connecting rods rotatably connected to the support are coaxially fixed at both ends of the support roller, a third rotating device for driving the corresponding connecting rod to rotate is arranged on the support, and a second telescopic rod is connected and fixed between the support and the rotating shaft; two symmetrically arranged clamping rollers are coaxially slidingly sleeved on the support roller, and a pushing rod for pushing the clamping roller to slide is arranged between the adjacent ends of the clamping roller and the support roller; a groove is horizontally opened in the support roller, a through hole is opened at the end of the groove and penetrates the side wall of the support roller, and a vacuum suction cup for the edging strip is arranged in the through hole.
3. The magnetic steel automatic glue dispensing and edge wrapping equipment according to claim 2 is characterized by: The groove and the through hole are not coaxial, and a connecting seat is connected to the side of the groove away from the through hole, a fourth rotating device for driving the connecting seat to rotate is arranged on the side wall of the groove, third telescopic rods parallel to the groove are fixed at both ends of the connecting seat, the vacuum suction cup of the edging strip is arranged at one of the output ends of the third telescopic rods, and a baffle for closing the through hole is fixed on the other end of the third telescopic rod, and the baffle is arc-shaped.
4. The magnetic steel automatic glue dispensing and edge wrapping equipment according to claim 3 is characterized by: The facing ends of adjacent pressure rollers are provided with coaxial circular grooves, and the circumferential sides of the circular grooves are hinged with fixed rods, and the movable ends of the fixed rods are coaxially slidably sleeved with pressing rollers, and elastic support members are provided between the pressing rollers and the fixed rods. The side walls of the fixed rods away from the supporting rollers are hinged with fourth telescopic rods, and the ends of the fourth telescopic rods are hinged to the end faces of the circular grooves.
5. The magnetic steel automatic glue dispensing and edge wrapping equipment according to claim 4 is characterized by: The dispensing device includes a liquid storage tank and a base, a mounting shaft horizontally and perpendicular to the base is rotatably connected to the side wall of the base, a fifth rotating device for driving the mounting shaft to rotate is arranged on the base, a dispensing nozzle is arranged on the mounting shaft, and a pump body for conveying colloid to the dispensing nozzle is arranged on the liquid storage tank.
6. The magnetic steel automatic glue dispensing and edge wrapping equipment according to claim 5, characterized in that: The ends of the pressing rollers are all provided with rubber cushion layers.
7. The magnetic steel automatic glue dispensing and edge wrapping equipment according to claim 6, characterized in that: The end of the pressing roller is arc-shaped.