CN114701246A

CN114701246A - Offset printing method and printing equipment

Info

Publication number: CN114701246A
Application number: CN202210409967.XA
Authority: CN
Inventors: 王威; 邱泰康; 黄国梅; 凡丽珍; 何金海
Original assignee: Letterpress Yicai Dongguan Packaging Printing Co ltd
Current assignee: Embossed Art Color Dongguan Printing Co ltd
Priority date: 2022-04-19
Filing date: 2022-04-19
Publication date: 2022-07-05
Anticipated expiration: 2042-04-19
Also published as: CN114701246B

Abstract

The invention discloses an offset printing method and printing equipment, which comprise an unwinding roller, a tensioning mechanism, a guide roller, a printing mechanism and a winding roller which are sequentially arranged along the conveying direction of a printing stock, wherein the printing mechanism comprises an elastic frame fixed on the printing mechanism, a printing area is formed at the bottom of the elastic frame, the printing stock is positioned in the printing area when passing through the printing mechanism, elastic inkpad is filled in the elastic frame, and a silk screen plate is assembled at the bottom of the elastic frame corresponding to the printing area. When the printing stock passes through the printing area of the elastic frame, the inkpad and the printing stock can be always in a tight fit state, and the second pressing wheel is directly pressed on the back of the printing stock, so that the printing stock and the inkpad are further fitted, the printing quality is ensured, and the influence on the printing quality due to the deformation of the middle part of the screen plate is avoided.

Description

Offset printing method and printing equipment

Technical Field

The invention relates to the technical field of printing, in particular to an offset printing method and printing equipment.

Background

In the offset printing process, two factors mainly influence the printing quality, wherein the first factor is the pressure between a rubber roller and a printing stock; the second is the degree of fit between the substrate and the printing surface. In the actual operation process, the printing stock usually passes through the frame with the inkpad, then rolls on the silk screen plate of frame bottom through the pressfitting of rubber roll to print the pattern on the printing stock on the silk screen plate, but after the silk screen plate was through a large amount of printing operation, because constantly exerted the effort by the rubber roll, its middle position can produce the concavity, and the concave part in the middle of the silk screen plate can't be well laminated with the printing stock, will influence printing quality like this.

Disclosure of Invention

The present invention is directed to a method and apparatus for offset printing to solve the above problems.

In order to achieve the purpose, the invention provides the following technical scheme: an offset printing device comprises an unwinding roller, a tensioning mechanism, a guide roller, a printing mechanism and a winding roller which are sequentially arranged along the conveying direction of a printing stock, the printing mechanism comprises an elastic frame fixed on the printing mechanism, a printing area is formed at the bottom of the elastic frame, the printing stock is positioned in the printing area when passing through the printing mechanism, the elastic frame is filled with elastic inkpad, the bottom of the elastic frame corresponding to the printing area is provided with a silk screen plate, the elastic frame is internally provided with an arc-shaped elastic sheet along the conveying direction of the printing stock, the middle part of the arc-shaped elastic sheet is arranged in a protruding way, the inner wall of the elastic frame is integrally assembled with arc-shaped supporting plates corresponding to the two ends of the arc-shaped elastic sheet, the two ends of the arc-shaped elastic sheet are inserted into grooves formed in the arc-shaped supporting plates, and the tail end of the arc-shaped elastic sheet and the inner part of the groove of the arc-shaped supporting plate are reserved with a movable space along the arc-shaped extending direction of the arc-shaped elastic sheet; and a first pressing wheel and a second pressing wheel are respectively arranged above and below the elastic frame, the first pressing wheel and the second pressing wheel can synchronously move oppositely in the vertical direction to press the upper end surface and the lower end surface of the elastic frame, and the first pressing wheel and the second pressing wheel are pressed on one end of the elastic frame and then move to the other end of the elastic frame along the conveying direction of a printing stock.

Preferably, the elastic frame is fixed at the inner side by a connecting rod connected with the peripheral side of the elastic frame; first pinch roller rotates and installs on the wheel carrier that its top was arranged, the wheel carrier is fixed with first transmission piece along its length direction's both ends, the second pinch roller rotates and installs on the wheel carrier that its below was arranged to the wheel carrier both ends that are equipped with the second pinch roller are fixed with the second transmission piece, and the mounting panel has been arranged to the wheel carrier top that is equipped with first pinch roller, first motor is installed at its length direction's both ends top to the mounting panel, the fixed threaded rod that has been connected after the mounting panel is extended downwards to the motor shaft of first motor, the threaded rod is extended downwards to extend behind first transmission piece and the second transmission piece and is rotated with the bottom and be linked to each other, first transmission piece and second transmission piece respectively with threaded rod screw-thread fit.

Preferably, the top of the mounting plate is fixedly provided with a limiting frame along the length direction thereof, a piston slide block is arranged on the inner side of the limiting frame, a rodless cylinder is fixed on the top along any side of the conveying direction of the printing stock, a piston rod of the rodless cylinder is erected on the top along the horizontal direction, and the piston rod penetrates through the limiting frame and the piston slide block and is in sliding fit with the limiting frame and the piston slide block; the bottom of the threaded rod is fixedly connected with a sliding block, a limiting groove is formed in the bottom of the threaded rod corresponding to the sliding direction of the sliding block, a second guide rod is fixed in the limiting groove along the groove length direction, and the sliding block is embedded into the limiting groove and is in sliding sleeve joint with the second guide rod; the top be located the both sides of piston rod still erect and be equipped with first guide bar, every first guide bar all runs through spacing frame and is connected with it sliding fit.

Preferably, the tensioning mechanism comprises fixed blocks arranged on two sides of the top of the U-shaped plate, a floating roller is rotatably connected between the two fixed blocks, and the printing stock output from the unwinding roller is guided into the guide roller through the floating roller; grooves are formed in the side walls of two sides of the U-shaped plate in the vertical direction, the tops of the grooves extend to the tops of the U-shaped plate, the grooves penetrate through the side walls of the U-shaped plate in the width direction of the U-shaped plate, second telescopic rods are arranged in the grooves in the vertical direction, the middle of each groove is separated into two groove bodies through horizontally arranged stop plates, the fixed ends of the second telescopic rods penetrate through the stop plates and then are distributed in the groove bodies below the second telescopic rods, the telescopic ends of the second telescopic rods upwards extend through the groove bodies above and then are fixedly connected with the fixed blocks, and the fixed blocks are in sliding fit with the groove bodies above; the movable end of the second telescopic rod is sleeved with a second spring, and the second spring is used for driving the fixed block and the stop plate to be away from each other.

Preferably, the bottom of the fixed end of the second telescopic rod is fixedly connected with a base, the base is connected with a groove body below the base in a sliding mode, and the fixed end of the second telescopic rod is connected with the stop plate in a sliding mode; when the first pressing wheel and the arc-shaped supporting plate are pressed on the elastic frame, the base slides upwards along the vertical direction to enable the floating roller to tension the printing stock.

Preferably, the roller support of direction roller both sides goes up to rotate and is connected with the fluted disc, the outer wall on rotate and install the gear with fluted disc engaged with, inside be fixed with the second motor that links to each other with the gear drive, the center department of fluted disc is fixed with the fixed axle, fixed cover has cup jointed first telescopic link on the periphery of fixed axle, the expansion end-to-end connection of first telescopic link has spacing backstop board, the expansion end of first telescopic link is close to the position department rotation of spacing backstop board and has cup jointed the sleeve pipe, first spring has been cup jointed between the stiff end of sleeve pipe and first telescopic link, be fixed with the rotation bush on the sheathed tube periphery, the rotation bush extends and swivelling joint on its outer wall towards the direction of base, through the anticlockwise rotation of first telescopic link makes the base along vertical direction upward movement.

Preferably, either side of first transmission piece is equipped with infrared emitter, go up the position department that corresponds infrared emitter and be equipped with the infrared receiving sensor who cooperates with it, infrared receiving sensor and second motor pass through the signal of telecommunication and establish connection.

The invention also provides an offset printing method, which is applied to the offset printing equipment and comprises the following steps:

the winding roller rotates to drive the printing stock on the unwinding roller to move on the tensioning mechanism, the guide roller and the printing mechanism in sequence, when the printing stock passes through the printing mechanism, the first pressing wheel and the second pressing wheel synchronously move in opposite directions until the first pressing wheel is pressed on the upper end surface of the elastic frame and the second pressing wheel is pressed on the back surface of the printing stock in a printing area, and at the moment, the winding roller stops rotating;

first pinch roller and second pinch roller move along stock direction of delivery afterwards, remove to the other end from elastic frame's one end, and first pinch roller acts on the arc shell fragment and makes the elasticity inkpad of arc shell fragment extrusion its below, makes elasticity inkpad and silk screen board laminating tight, and the second pinch roller acts on the stock back and makes it laminate with silk screen board, accomplishes the printing through first pinch roller and second pinch roller synchronous movement cooperation on elastic frame.

Compared with the prior art, the invention provides an offset printing method and printing equipment, which have the following beneficial effects:

(1) when a printing stock passes through a printing area of the elastic frame, the first pressing wheel and the second pressing wheel can synchronously move oppositely in the vertical direction to press the upper end surface and the lower end surface of the elastic frame, the first pressing wheel and the second pressing wheel are pressed at one end of the elastic frame and then move to the other end of the elastic frame along the conveying direction of the printing stock, the first pressing wheel acts on the arc-shaped elastic sheet in the moving process along the conveying direction of the printing stock, the arc-shaped elastic sheet is downwards sunken due to stress, so that inkpad below the arc-shaped elastic sheet is attached to the screen plate, the attaching degree of the inkpad and the printing stock is ensured, the second pressing wheel is directly pressed on the back of the printing stock, the printing stock and the inkpad are further attached, the printing quality is ensured, and the influence on the printing quality due to the deformation of the middle part of the screen plate is avoided.

(2) The tensioning mechanism can also tension the printing stock on the unwinding roller during printing, because the unwinding roller has inertia, when the first pinch roller and the second pinch roller are pressed on the elastic frame, the printing stock on the unwinding roller is still in a release state, at the moment, infrared rays are emitted to the infrared receiving sensor through the infrared emitter on the first transmission block, when the infrared receiving sensor receives the infrared rays, the infrared receiving sensor controls the second motor to drive the gear to rotate through the second motor, the gear disc is further driven to rotate, the gear disc drives the first telescopic rod to swing through action, the floating roller is further driven to move upwards, the printing stock at the position is tensioned again, after printing is finished, the second motor stops working, the floating roller returns to an initial position under the action of the first spring and the second spring, and the tension force of the printing stock under the action force of the two springs is not large compared with the initial tension force, therefore, the printing stock can be uniformly wound on the winding roller, the pause and the contusion caused by the loss of the tension of the printing stock on the unwinding roller and the winding roller are reduced, and the phenomenon that the printing stock is pulled apart is avoided.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention without limiting the invention in which:

FIG. 1 is a schematic view of the entire printing apparatus in the embodiment at an axial view angle;

FIG. 2 is a schematic front view of the entire printing apparatus in the embodiment;

FIG. 3 is a schematic view of the printing mechanism of the embodiment shown from an axial perspective;

FIG. 4 is a schematic view of a printing mechanism according to an embodiment from another perspective;

FIG. 5 is a schematic structural diagram of an elastic frame according to an embodiment;

FIG. 6 is a schematic cross-sectional view of the elastomeric frame of FIG. 5 taken from an axial perspective;

FIG. 7 is a schematic view of a tension mechanism proposed in the embodiment;

FIG. 8 is an enlarged view of a portion of the structure of FIG. 7 at A;

fig. 9 is a schematic view of the assembly of the tensioning mechanism proposed in the embodiment on a U-shaped plate.

In the figure: 1. unwinding the roller; 2. a roller bracket; 3. a tensioning mechanism; 4. a guide roller; 5. a printing mechanism; 6. a wind-up roll; 7. a first telescopic rod; 8. a fluted disc; 9. a gear; 10. a rodless cylinder; 11. a piston rod; 12. a first guide bar; 13. a limiting frame; 14. mounting a plate; 15. a first motor; 16. a threaded rod; 17. a first transmission block; 18. a wheel carrier; 19. a first pinch roller; 20. an infrared emitter; 21. an elastic frame; 22. a connecting rod; 23. a second pinch roller; 24. a second transmission block; 25. a slider; 26. a limiting groove; 27. a second guide bar; 28. a piston slide block; 29. an infrared receiving sensor; 30. a second motor; 31. a printing area; 32. an arc-shaped support plate; 33. an arc-shaped elastic sheet; 34. a wire mesh plate; 35. elastic inkpad; 36. a fixed shaft; 37. a first spring; 38. a stopper plate; 39. a U-shaped plate; 40. a fixed block; 41. a floating roller; 42. a second telescopic rod; 43. a base; 44. a sleeve; 45. a limit stop plate; 46. rotating the bushing; 47. a second spring; 48. and a frame.

Detailed Description

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 only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 9, the present embodiment provides an offset printing apparatus, which includes an unwinding roller 1, a tensioning mechanism 3, a guide roller 4, a printing mechanism 5, and a winding roller 6 sequentially arranged along a printing material conveying direction.

Wherein, the printing mechanism 5 in this embodiment includes an elastic frame 21 fixed on a frame 48, a printing area 31 is formed at the bottom of the elastic frame 21, the printing object is located in the printing area 31 when passing through the printing mechanism 5, elastic inkpad 35 is filled inside the elastic frame 21, a screen plate 34 is assembled at the bottom of the elastic frame 21 corresponding to the printing area 31, an arc-shaped elastic sheet 33 is arranged inside the elastic frame 21 along the conveying direction of the printing object, the middle part of the arc-shaped elastic sheet 33 is protruded upward, arc-shaped support plates 32 are integrally assembled on the inner wall of the elastic frame 21 corresponding to the two ends of the arc-shaped elastic sheet 33, the two ends of the arc-shaped elastic sheet 33 are inserted into a groove formed inside the arc-shaped support plate 32, a movable space is reserved between the ends of the arc-shaped elastic sheet 33 and the groove inside the arc-shaped support plate 32 along the arc-shaped extending direction of the arc-shaped elastic sheet 33, and the initial state of the arc-shaped elastic sheet 33 is as shown in fig. 6, after the arc-shaped elastic sheet 33 is deformed, the two ends of the arc-shaped elastic sheet extend along the arc length direction to slide towards the bottom of the inner groove of the arc-shaped support plate 32, and after the arc-shaped elastic sheet 33 is deformed, the arc-shaped elastic sheet 33 is restored to the initial position again. A first pressing wheel 19 and a second pressing wheel 23 are respectively arranged above and below the elastic frame 21, the first pressing wheel 19 and the second pressing wheel 23 can synchronously move oppositely in the vertical direction to press the upper end face and the lower end face of the elastic frame 21, and the first pressing wheel 19 and the second pressing wheel 23 are pressed on one end of the elastic frame 21 and then move to the other end of the elastic frame 21 along the conveying direction of a printing stock.

When the scheme is implemented, the winding roller 6 rotates to drive the printing stock on the unwinding roller 1 to move sequentially through the tensioning mechanism 3, the guide roller 4 and the printing mechanism 5, and finally the printing stock is wound on the winding roller 6 after printing is completed. When a printing stock passes through the printing mechanism 5, the first pressing wheel 19 and the second pressing wheel 23 synchronously move in opposite directions until the first pressing wheel 19 is pressed on the upper end surface of the elastic frame 21 and the second pressing wheel 23 is pressed on the back surface of the printing stock in the printing area 31, and at the moment, the wind-up roll 6 stops rotating;

first pinch roller 19 and second pinch roller 23 follow the stock direction of delivery motion afterwards, move to the other end from the one end of elastic frame 21, and first pinch roller 19 acts on arc shell fragment 33 and makes arc shell fragment 33 extrude the elasticity inkpad 35 of its below, makes elasticity inkpad 35 and silk screen board 34 laminate tightly, and second pinch roller 23 acts on the stock back and makes it laminate with silk screen board 34, accomplishes the printing through first pinch roller 19 and the cooperation of second pinch roller 23 synchronous motion on elastic frame 21.

As shown in fig. 3, the elastic frame 21 in the above-described aspect is fixed to the inside of the frame 48 by the connection rod 22 connected to the periphery side thereof. The first pinch roller 19 is rotatably installed on a wheel frame 18 arranged above the first pinch roller 19, two ends of the wheel frame 18 along the length direction are fixed with first transmission blocks 17, the second pinch roller 23 is rotatably installed on the wheel frame 18 arranged below the second pinch roller 23, two ends of the wheel frame 18 provided with the second pinch roller 23 are fixed with second transmission blocks 24, an installation plate 14 is arranged above the wheel frame 18 provided with the first pinch roller 19, two ends of the installation plate 14 along the length direction are provided with first motors 15, motor shafts of the first motors 15 downwards extend through the installation plate 14 and then are fixedly sleeved with threaded rods 16, the threaded rods 16 downwards extend through the first transmission blocks 17 and the second transmission blocks 24 and then are rotatably connected with the bottom of a frame 48, the first transmission blocks 17 and the second transmission blocks 24 are respectively in threaded fit with the threaded rods 16, and the thread directions inside the first transmission blocks 17 and the second transmission blocks 24 are opposite, the threaded rod 16 is driven to rotate by starting the first motor 15, and the first transmission block 17 and the second transmission block 24 synchronously move in opposite directions on the threaded rod 16 due to the fact that the thread directions of the first transmission block 17 and the second transmission block 24 are opposite, so that the first pressing wheel 19 and the second pressing wheel 23 are driven to move in opposite directions and are pressed on the elastic frame 21.

Further, on the basis of the above scheme, in order to realize that the first pressing wheel 19 and the second pressing wheel 23 move along the conveying direction of the printing stock after being pressed on the elastic frame 21, in this embodiment, the top of the mounting plate 14 is fixedly provided with the limiting frame 13 along the length direction thereof, the inner side of the limiting frame 13 is provided with the piston slider 28, the top of the frame 48 is fixedly provided with the rodless cylinder 10 along any side of the conveying direction of the printing stock, the piston rod 11 of the rodless cylinder 10 is erected at the top of the frame 48 along the horizontal direction, the piston rod 11 penetrates through the limiting frame 13 and the piston slider 28 and is in sliding fit with the same, the piston slider 28 is driven by the rodless cylinder 10 to slide on the piston rod 11, and the piston slider 28 is fixed on the mounting plate 14, so that the mounting plate 14 is driven to move along the rod length direction of the piston rod 11, the first guide rods 12 are also erected at the top of the frame 48 on both sides of the piston rod 11, each first guide rod 12 penetrates through the limiting frame 13 and is connected with the limiting frame in a sliding fit mode, and the limiting frame 13 is matched with the two first guide rods 12 to improve the stability of the mounting plate 14 when the mounting plate moves along the piston rod 11. The bottom fixedly connected with slider 25 of threaded rod 16, the frame 48 bottom is formed with spacing groove 26 corresponding to the slip direction of slider 25, spacing groove 26 is inside to be fixed with second guide bar 27 along its groove length direction, slider 25 imbeds to spacing groove 26 and slides and cup joints on second guide bar 27, mounting panel 14 is when the long direction motion of pole of piston rod 11, the slider 25 of threaded rod 16 bottom slides in spacing groove 26, and slider 25 overlaps all the time on second guide bar 27, can avoid it to follow slippage in spacing groove 26.

As shown in fig. 7, the printing apparatus according to the embodiment further includes a tensioning mechanism 3, before starting printing, first, the tensioning mechanism 3 adjusts the tensioning force between the wind-up roller 6 and the wind-up roller 1, so that the printing material can be uniformly and tightly wound on the wind-up roller 6 after printing is finished, and the tensioning mechanism 3 in this embodiment includes fixing blocks 40 arranged on both sides of the top of the U-shaped plate 39, a floating roller 41 is rotatably connected between the two fixing blocks 40, the printing material output from the wind-up roller 1 is guided into the guide roller 4 through the floating roller 41, before starting printing, the printing material generates a pressure to the fixing blocks 40 through the floating roller 41, and the pressure makes the fixing blocks 40 move downward. Grooves are formed in the side walls of two sides of the U-shaped plate 39 in the vertical direction, the top of each groove extends to the top of the U-shaped plate 39, the grooves penetrate through the side walls of the U-shaped plate 39 in the width direction of the U-shaped plate 39, a second telescopic rod 42 is arranged in each groove in the vertical direction, the middle of each groove is separated into two groove bodies through a horizontally arranged stop plate 38, the fixed end of each second telescopic rod 42 penetrates through the corresponding stop plate 38 and then is distributed in the groove body below, the telescopic end of each second telescopic rod 42 upwards extends through the groove body above and then is fixedly connected with a fixed block 40, and the fixed block 40 is in sliding fit with the groove body above; the movable end of the second telescopic rod 42 is sleeved with a second spring 47, the second spring 47 is used for driving the fixing block 40 and the stop plate 38 to be away from each other, when the fixing block 40 has a downward movement trend under the pressure of the printing stock, the movable end of the second telescopic rod 42 is contracted, the movable end moves into the groove above the groove, the second spring 47 is compressed, and the printing stock is in a tensioning state at the moment.

When the first pressing wheel 19 and the second pressing wheel 23 are pressed on the elastic frame 21, the printing mechanism 5 starts printing on the printing stock, in this state, the winding roller 6 stops working, and the printing stock stops being conveyed forwards, but because the unwinding roller 1 has inertia, the printing stock on the unwinding roller 1 is continuously released from the unwinding roller 1 under the action of inertia, so that the part of the printing stock loses tension, and after printing is finished, the winding roller 6 cannot be tightly wound on the winding roller 6 when working. In order to avoid the above situation, in the present embodiment, the base 43 is fixedly connected to the bottom of the fixed end of the second telescopic rod 42, the base 43 is connected to the lower groove body in a sliding manner, and the fixed end of the second telescopic rod 42 is connected to the stop plate 38 in a sliding manner; when the first pinch roller 19 and the arc-shaped support plate 32 are pressed on the elastic frame 21, the printing stock stops being conveyed, and at the same time, the second spring 47 in a compressed state returns to be deformed, and the base 43 slides upwards in the vertical direction, so that the floating roller 41 tensions the printing stock.

In order to drive the floating roller 41 to move upwards, in the embodiment, the roller supports 2 at two sides of the guide roller 4 are rotatably connected with a fluted disc 8, a gear 9 engaged with the fluted disc 8 is rotatably installed on the outer wall of a frame 48, a second motor 30 connected with the gear 9 in a driving manner is fixed inside the frame 48, a fixed shaft 36 is fixed at the center of the fluted disc 8, a first telescopic rod 7 is fixedly sleeved on the circumferential surface of the fixed shaft 36, a limit stop plate 45 is connected at the tail end of the movable end of the first telescopic rod 7, a sleeve 44 is rotatably sleeved at the position of the movable end of the first telescopic rod 7 close to the limit stop plate 45, a first spring 37 is sleeved between the sleeve 44 and the fixed end of the first telescopic rod 7, a rotating bush 46 is fixed on the circumferential surface of the sleeve 44, the rotating bush 46 extends towards the direction of the base 43 and is rotatably connected to the outer wall thereof, the gear 9 is driven to rotate by the second motor 30, and the fluted disc 8 is meshed with the gear 9, so that the fluted disc 8 rotates oppositely, the fluted disc 8 drives the first telescopic rod 7 to rotate anticlockwise in the rotating process through the fixed shaft 36, the movable end of the first telescopic rod 7 extends in the rotating process, the base 43 is driven to slide upwards in the groove, finally, the base 43 slides to the joint with the stop plate 38, and the second spring 47 is in a compressed state at the moment.

In order to enable the floating roller 41 to act immediately when the first pressing wheel 19 and the second pressing wheel 23 are pressed on the elastic frame 21, as shown in fig. 3 and 4, an infrared emitter 20 is assembled on any side of the first transmission block 17, and an infrared receiving sensor 29 matched with the infrared emitter 20 is assembled on the frame 48 at a position corresponding to the infrared emitter 20, that is, when the first pressing wheel 19 is just pressed on the elastic frame 21, the infrared ray emitted by the infrared emitter 20 can be received by the infrared receiving sensor 29, the infrared receiving sensor 29 is connected with the second motor 30 through an electric signal, and the infrared receiving sensor 29 generates an electric signal to control the second motor 30 to rotate after receiving the infrared ray, so that the floating roller 41 is started to move upwards. When the first pinch roller 19 and the second pinch roller 23 move along the conveying direction of the printing stock, the second motor 30 is always in a working state to drive the gear 9 to rotate rapidly, the diameter of the fluted disc 8 is far larger than that of the gear 9, so the rotating speed of the fluted disc 8 is slow, the floating roller 41 moves upwards slowly to tension the printing stock, when the first pinch roller 19 and the second pinch roller 23 move to the other end of the elastic frame 21, after printing is finished, the first pinch roller 19 and the second pinch roller 23 return to the initial position, at the moment, the infrared emitter 20 and the infrared receiving sensor 29 are not in the same horizontal plane, the infrared receiving sensor 29 cannot receive infrared rays, the second motor 30 stops operating, the first telescopic rod 7 returns to the initial position under the action of the first spring 37, and in the process, the floating roller 41 slowly returns to the initial position under the action of the first spring 37 and the second spring 47, and the difference between the tension of the printing stock and the initial tension is not large in the whole process, so that the winding uniformity of the winding roller 6 is guaranteed.

In the description of the present invention, the terms "first", "second", "another", and "yet" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. The utility model provides an offset printing equipment, including unreeling roller (1), straining device (3), guide roller (4), printing mechanism (5) and wind-up roll (6) that set gradually along stock direction of delivery, its characterized in that: the printing mechanism (5) comprises an elastic frame (21) fixed on a machine frame (48), a printing area (31) is formed at the bottom of the elastic frame (21), a printing stock is located in the printing area (31) when passing through the printing mechanism (5), elastic inkpad (35) is filled in the elastic frame (21), a wire mesh plate (34) is assembled at the position, corresponding to the printing area (31), of the bottom of the elastic frame (21), an arc-shaped elastic sheet (33) is arranged in the elastic frame (21) along the conveying direction of the printing stock, the middle of the arc-shaped elastic sheet (33) is arranged in a protruding mode, arc-shaped support plates (32) are integrally formed at two ends, corresponding to the arc-shaped elastic sheet (33), of the inner wall of the elastic frame (21), and arc-shaped support plates (32) are inserted into grooves formed in the arc-shaped support plates (32), and the tail end of the arc-shaped elastic sheet (33) and the inner part of the groove of the arc-shaped support plate (32) are reserved with a movable space along the arc-shaped extension direction of the arc-shaped elastic sheet (33); a first pressing wheel (19) and a second pressing wheel (23) are respectively arranged above and below the elastic frame (21), the first pressing wheel (19) and the second pressing wheel (23) can synchronously move in opposite directions in the vertical direction to press the upper end surface and the lower end surface of the elastic frame (21), and the first pressing wheel (19) and the second pressing wheel (23) are pressed at one end of the elastic frame (21) and then move to the other end of the elastic frame (21) along the conveying direction of a printing stock.

2. An offset printing apparatus according to claim 1, wherein: the elastic frame (21) is fixed on the inner side of the frame (48) through a connecting rod (22) connected with the peripheral side of the elastic frame; the first pressure wheel (19) is rotatably arranged on a wheel frame (18) arranged above the first pressure wheel, the two ends of the wheel carrier (18) along the length direction are fixed with first transmission blocks (17), the second pressure wheel (23) is rotatably arranged on a wheel frame (18) arranged below the second pressure wheel, and both ends of the wheel frame (18) equipped with the second pinch roller (23) are fixed with second transmission blocks (24), an installation plate (14) is arranged above the wheel frame (18) equipped with the first pinch roller (19), the tops of two ends of the mounting plate (14) along the length direction are provided with a first motor (15), a motor shaft of the first motor (15) extends downwards to pass through the mounting plate (14) and then is fixedly sleeved with a threaded rod (16), the threaded rod (16) extends downwards through the first transmission block (17) and the second transmission block (24) and then is connected with the bottom of the frame (48) in a rotating way, the first transmission block (17) and the second transmission block (24) are respectively in threaded fit with the threaded rod (16).

3. An offset printing apparatus according to claim 2, wherein: the top of the mounting plate (14) is fixedly provided with a limiting frame (13) along the length direction of the mounting plate, a piston sliding block (28) is arranged on the inner side of the limiting frame (13), a rodless cylinder (10) is fixed on the top of the rack (48) along any side of the conveying direction of a printing stock, a piston rod (11) of the rodless cylinder (10) is erected on the top of the rack (48) along the horizontal direction, and the piston rod (11) penetrates through the limiting frame (13) and the piston sliding block (28) and is in sliding fit with the limiting frame (13) and the piston sliding block (28); the bottom of the threaded rod (16) is fixedly connected with a sliding block (25), a limiting groove (26) is formed in the bottom of the rack (48) corresponding to the sliding direction of the sliding block (25), a second guide rod (27) is fixed in the limiting groove (26) along the groove length direction, and the sliding block (25) is embedded into the limiting groove (26) and is sleeved on the second guide rod (27) in a sliding manner; the top of the machine frame (48) is provided with first guide rods (12) on two sides of the piston rod (11), and each first guide rod (12) penetrates through the limiting frame (13) and is connected with the limiting frame in a sliding fit mode.

4. An offset printing apparatus according to claim 2 or 3, wherein: the tensioning mechanism (3) comprises fixed blocks (40) arranged on two sides of the top of the U-shaped plate (39), a floating roller (41) is rotatably connected between the two fixed blocks (40), and a printing stock output from the unwinding roller (1) is guided into the guide roller (4) through the floating roller (41); the groove is formed in the side walls of two sides of the U-shaped plate (39) in the vertical direction, the top of the groove extends to the top of the U-shaped plate (39), the groove penetrates through the side walls of the U-shaped plate (39) in the width direction of the U-shaped plate (39) and is arranged, a second telescopic rod (42) is arranged in the groove in the vertical direction, the middle of the groove is separated into two groove bodies through a stop plate (38) which is horizontally arranged, the fixed end of the second telescopic rod (42) penetrates through the stop plate (38) and then is distributed in the groove body below, the telescopic end of the second telescopic rod (42) upwards extends through the groove body above and then is fixedly connected with a fixed block (40), and the fixed block (40) is in sliding fit with the groove body above; the movable end of the second telescopic rod (42) is sleeved with a second spring (47), and the second spring (47) is used for driving the fixed block (40) and the stop plate (38) to be away from each other.

5. An offset printing apparatus according to claim 4, wherein: the bottom of the fixed end of the second telescopic rod (42) is fixedly connected with a base (43), the base (43) is in sliding connection with a groove body below, and the fixed end of the second telescopic rod (42) is in sliding connection with the stop plate (38); when the first pressing wheel (19) and the arc-shaped supporting plate (32) are pressed on the elastic frame (21), the base (43) slides upwards along the vertical direction, so that the floating roller (41) tensions a printing stock.

6. An offset printing apparatus according to claim 5, wherein: the roller support (2) of direction roller (4) both sides go up to rotate and are connected with fluted disc (8), rotate on the outer wall of frame (48) and install gear (9) with fluted disc (8) engaged with, the inside of frame (48) is fixed with second motor (30) that link to each other with gear (9) drive, the center department of fluted disc (8) is fixed with fixed axle (36), fixed first telescopic link (7) of having cup jointed on the periphery of fixed axle (36), the expansion end-to-end connection of first telescopic link (7) has spacing backstop board (45), the position department that the expansion end of first telescopic link (7) is close to spacing backstop board (45) rotates and has cup jointed sleeve pipe (44), first spring (37) has been cup jointed between the stiff end of sleeve pipe (44) and first telescopic link (7), be fixed with on the periphery of sleeve pipe (44) and rotate bush (46), the rotating bush (46) extends towards the direction of the base (43) and is rotatably connected to the outer wall of the base, and the base (43) is moved upwards in the vertical direction through the anticlockwise rotation of the first telescopic rod (7).

7. An offset printing apparatus according to claim 6, wherein: any side of the first transmission block (17) is provided with an infrared emitter (20), an infrared receiving sensor (29) matched with the infrared emitter is arranged at the position, corresponding to the infrared emitter (20), on the rack (48), and the infrared receiving sensor (29) is connected with the second motor (30) through an electric signal.

8. An offset printing method applied to an offset printing apparatus according to any one of claims 1 to 7, characterized in that: the method comprises the following steps:

the winding roller (6) rotates to drive the printing stock on the unwinding roller (1) to move on the tensioning mechanism (3), the guide roller (4) and the printing mechanism (5) in sequence, when the printing stock passes through the printing mechanism (5), the first pressing wheel (19) and the second pressing wheel (23) synchronously move in opposite directions until the first pressing wheel (19) is pressed on the upper end face of the elastic frame (21) and the second pressing wheel (23) is pressed on the back face of the printing stock in the printing area (31), and at the moment, the winding roller (6) stops rotating;

first pinch roller (19) and second pinch roller (23) move along stock direction of delivery afterwards, move to the other end from the one end of elastic frame (21), first pinch roller (19) act on arc shell fragment (33) and make arc shell fragment (33) extrude elasticity inkpad (35) of its below, make elasticity inkpad (35) and silk screen board (34) laminating tight, second pinch roller (23) act on the stock back and make it laminate with silk screen board (34), accomplish the printing through first pinch roller (19) and second pinch roller (23) synchronous motion cooperation on elastic frame (21).