Two-color cylinder printing machine with fixed-step stepping traction equipment

Abstract

The present invention discloses a two-color roller printing machine matched with a fixed-step stepping traction device. Purpose: To provide a two-color roller printing machine matched with a fixed-step stepping traction device, which has a compact structure and high printing efficiency. Solution: The two-color roller printing machine matched with the fixed-step stepping traction device comprises: a guiding device; a first printing roller; a second printing roller; a printing roller; a paper feed roller, which moves between a first position and a second position during the interval of the stepping of the traction device, and drives the paper to make a reciprocating motion; when the paper feed roller moves from the first position to the second position, the printing roller is attached to the surface of the first printing roller, and the movement of the paper drives the printing roller and the printing roller to make a counter-rolling motion to realize the first color printing; when the paper feed roller moves from the second position to the first position, the printing roller is attached to the surface of the second printing roller, and the movement of the paper drives the printing roller and the printing roller to make a counter-rolling motion to realize the second color printing. Applicable to the packaging printing industry.

Description

Technical Field

[0001] The present invention relates to the field of printing machines. Specifically, the printing machine is used to match fixed-step stepping traction mode equipment (such as packaging machines) to complete online two-color printing. During printing, the paper does not need to move synchronously with the traction equipment at the same linear speed. It is independently controlled, has a compact structure, high printing efficiency, accurate color registration, and flexible application occasions. Background Art

[0002] Printing machines are widely used in food, beverage, tobacco, medicine, health care products, and cosmetics industries, especially in the printing of flexible packaging materials and paper container packaging.

[0003] As packaging colors become more and more abundant, some two-color printing machines have gradually appeared on the market. For example, Chinese invention patent No. 201820221336.4 discloses an automated two-color printing device, which includes a device base, a bottom plate is arranged on the top of the device base, a dual servo motor is arranged on the top of the bottom plate, a first active conveying roller and a second active conveying roller are arranged on both sides of the dual servo motor, a conveyor belt is arranged on the top of the first active conveying roller and the second active conveying roller, a front dryer is arranged at the bottom of the conveyor belt, a first printing roller and a second printing roller are arranged on the conveyor belt, a support frame is arranged inside the first printing roller and the second printing roller, a positioning block is arranged on the support frame, a post-dryer is arranged on one side of the positioning block, a second driven conveying roller is arranged on one side of the post-dryer, and a receiving drum is arranged on one side of the second driven conveying roller, and dual drive is achieved by arranging dual servo motors. The Chinese invention patent with patent number 201820867124.3 discloses a two-color printing component, including a first and a second printing unit arranged up and down on a printing frame, a first and a second guide roller are provided at the left end of the first printing unit to lead the self-sealing film bag printed by the first printing unit, and then lead it down to the bottom of the first printing unit through the third and fourth guide rollers, and then lead it to the right end of the second printing unit by the fifth, sixth and seventh guide rollers, and the left end of the second printing unit is provided with an eighth and a ninth guide roller to lead the self-sealing film bag printed by the second printing unit; a first oven is provided between the second and the third guide rollers, and a second oven is provided between the eighth and the ninth guide rollers; the self-sealing film bag passing between the third and the fourth guide rollers and the self-sealing film bag passing between the eighth and the ninth guide rollers are close to each other at a certain position, and a third oven is provided at the close position to accommodate both at the same time.

[0004] The above two-color printing equipment places two printing machines side by side or superimposed, which takes up a large space, is costly, and the paper winding is too long, which will affect the packaging color registration, etc. It is also impossible to complete two-color printing online with fixed-step stepping traction equipment (such as packaging machines). Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned problems and provide a two-color cylinder printing machine matched with a fixed-step stepping traction device, which has a compact structure and high printing efficiency.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] Two-color cylinder printing machine with fixed-step stepping traction equipment, including:

[0008] A guide device for guiding the paper to move forward when the traction device pulls the paper forward;

[0009] A first printing cylinder, the rotation of which is driven and controlled by a motor;

[0010] A second printing cylinder, the rotation of which is driven and controlled by a motor;

[0011] The printing roller is located between the two printing rollers and can move relative to the two printing rollers;

[0012] The paper feed roller moves between a first position and a second position during the interval of the stepping of the traction device, driving the paper to do reciprocating motion;

[0013] When the paper feed roller moves from the first position to the second position, the printing roller is attached to the surface of the first printing roller (so that the paper carried on the surface of the printing roller is attached to the surface of the first printing roller), and the movement of the paper drives the printing roller to rotate, and then the printing roller (the first printing roller) is rolled to realize the first color printing; when the paper feed roller moves from the second position to the first position, the printing roller is attached to the surface of the second printing roller (so that the paper carried on the surface of the printing roller is attached to the surface of the second printing roller), and the movement of the paper drives the printing roller to rotate, and then the printing roller (the second printing roller) is rolled to realize the second color printing, and the printing plates of the first color printing and the second color printing are completely overlapped. The structure is compact and occupies little space; the structural design of arranging a printing roller on each side of the printing roller is adopted, and the paper winding length is shorter than the side-by-side and superimposed structures, which effectively improves the printing efficiency and can realize the color printing of the same layout.

[0014] Preferably, the distance between the first position and the second position is Where L is the length of a printing plate, π is the circumference, D is the outer diameter of the printing cylinder, and θ is the center angle of the arc segment between the tangent points J and K of the printing cylinder and the two printing cylinders when two-color printing is performed. Since there is a certain paper winding length between the tangent points J and K of the printing cylinder and the two printing cylinders when two-color printing is performed, in order to ensure that the printing plates of the first color printing and the second color printing are completely overlapped, the distance between the first position and the second position is set to The center angle of the arc segment corresponding to the tangent points J and K between the printing roller and the two printing rollers when two-color printing is performed, specifically refers to: the tangent point J between the printing roller and the first printing roller when the first color is printed, the tangent point K between the printing roller and the second printing roller when the second color is printed, and the center angle of the arc segment corresponding to the two tangent points.

[0015] Preferably, when the printing length is long, in order to avoid the printing ink from being undried and causing contamination to the printing machine or paper, the printing machine further comprises an adjusting roller as one of the paper conveying rollers, the adjusting roller can move relative to the printing cylinder, and adjust the paper winding length between the tangent points J and K of the printing cylinder and the two printing cylinders respectively during two-color printing. The adjusting roller is parallel to the axis of the printing cylinder, and the two printing cylinders are symmetrically arranged with the plane where the adjusting roller and the swing axis of the printing cylinder are located as the symmetry plane.

[0016] Preferably, the paper winding length between the tangent points J and K between the printing roller and the two printing rollers during two-color printing is nH; wherein n is an integer greater than or equal to 1, H is the moving step length of the traction device, and the distance between the first position and the second position of its paper feed roller is L / 2; and L is the length of a printing plate. The paper winding length between the tangent points J and K between the printing roller and the two printing rollers during two-color printing specifically refers to: the tangent point J between the printing roller and the first printing roller during the first color printing, and the tangent point K between the printing roller and the second printing roller during the second color printing, and the paper winding length from point J to point K according to the paper travel direction.

[0017] Preferably, the printing machine also includes a color mark reading device that moves following the adjustment roller, for reading the positioning color block printed on the paper when printing the first color, so as to obtain the positioning color block offset (the offset can be calculated by pulse counting, for example, it is set to stop after 100 pulses after reading the color mark, and actually stops after 150 pulses after reading the color mark, and the travel distance of 50 pulses is calculated as the positioning color block offset), correcting the start point position of the second printing roller to eliminate the color registration error caused by the cumulative error of the traction step error and the paper tension change.

[0018] Preferably, the position of the starting point of the second printing roller is corrected, specifically:

[0019] According to the formula The correction angle α of the second printing roller is calculated, where α is the correction angle of the second printing roller, β is the offset of the positioning color block, π is the pi, and F is the outer diameter of the second printing roller; the offset β is: the difference between the distance traveled by the positioning color block when the first color is printed after the positioning color block is read by the color mark reading device until the paper stops moving and the set distance, for example, if it is set to stop 3 mm after reading the color mark, and actually stops 3.5 mm after reading the color mark, β=3.5-3=0.5mm.

[0020] The second printing cylinder rotates clockwise (+) or counterclockwise (-) by a correction angle α.

[0021] Preferably, the guiding device comprises:

[0022] A first guide roller group for guiding the paper to be printed to the first color printing area, wherein a paper brake is provided at the paper feeding end;

[0023] The paper after the second color printing is guided to the second guide roller group of the traction device, and the paper outlet end is provided with a paper brake. The two paper brakes are used to brake both the paper feed end and the paper outlet end, and then the paper is pulled by the paper feed roller to reciprocate between the first position and the second position while the paper feed and outlet ends of the printing press remain stationary; the paper feed roller moves between the first position and the second position during the intermittent period of the traction device stepping, driving the paper to reciprocate.

[0024] Preferably, the printing press also includes a printing roller rocker arm rotatably mounted on the printing press frame, the printing roller is rotatably mounted on one end of the printing roller rocker arm, and the other end of the printing roller rocker arm is connected to a swing arm driving cylinder for driving the printing roller rocker arm to move so as to realize the swinging of the printing roller between the two printing rollers.

[0025] Preferably, an adjustable limiter is provided at each side of the end of the printing roller rocker arm, which is used to control the swing amplitude of the printing roller rocker arm, so that the paper on the printing roller is close to the printing roller during printing. The adjustable limiter includes a base with a threaded hole and a screw threadedly connected to the base, and the swing amplitude of the roller rocker arm is adjusted by adjusting the screw.

[0026] Preferably, the end of the printing roller rocker arm is also provided with a reset mechanism movable relative to the printing roller rocker arm, and the reset mechanism forces the printing roller to reset and break away from contact with the two printing rollers.

[0027] Preferably, the printing press also includes a first inking mechanism arranged in conjunction with the first printing roller and a second inking mechanism arranged in conjunction with the second printing roller; the first and second inking mechanisms can swing relative to the first and second printing rollers respectively, so that the first inking mechanism is close to the first printing roller and makes a counter-rolling motion, and the second inking mechanism is close to the second printing roller and makes a counter-rolling motion, so as to achieve inking.

[0028] Preferably, the first printing roller and the second printing roller are symmetrically arranged with the vertical line where the swing axis of the printing roller is located as the symmetry axis.

[0029] Preferably, the paper is pulled by the packaging machine and runs synchronously.

[0030] A two-color cylinder printing machine matched with a fixed-step length stepping traction device comprises:

[0031] A guide device for guiding the paper to move forward when the traction device pulls the paper forward;

[0032] a first printing cylinder;

[0033] a second printing cylinder;

[0034] The printing roller is located between the two printing rollers and can move relative to the two printing rollers;

[0035] The paper feed roller moves between a first position and a second position during the interval of the stepping of the traction device, driving the paper to do reciprocating motion;

[0036] When the paper feed roller moves from the first position to the second position, the two printing rollers simultaneously adhere to the paper on the surface of the printing roller, and the movement of the paper drives the printing roller to rotate, and then the two printing rollers perform counter-rolling movement to respectively realize the first color printing and the second color printing, and the printing plates of the first color printing and the second color printing completely overlap; when the two printing rollers are separated from the paper on the surface of the printing roller, the paper feed roller moves from the second position to the first position. The synchronous two-color printing method is used, and the printing efficiency is high and the registration accuracy is high.

[0037] Preferably, the printing length of the first color printing reaches When the starting printing point of the printing plate on the second printing roller contacts the paper on the printing roller, the printing plates of the first and second colors are completely overlapped. π is the pi, D is the outer diameter of the printing roller, and θ is the center angle of the arc segment between the tangent points J and K of the printing roller and the two printing rollers during two-color printing.

[0038] Preferably, the distance between the first position and the second position is Where L is the length of a printing plate, π is the circumference, D is the outer diameter of the printing cylinder, and θ is the center angle of the arc segment between the tangent points J and K of the printing cylinder and the two printing cylinders when two-color printing is performed. Since there is a certain paper winding length between the tangent points J and K of the printing cylinder and the two printing cylinders when two-color printing is performed, in order to ensure that the printing plates of the first color printing and the second color printing are completely overlapped, the distance between the first position and the second position is set to The center angle of the arc segment corresponding to the tangent points J and K between the printing roller and the two printing rollers when two-color printing is performed, specifically refers to: the tangent point J between the printing roller and the first printing roller when the first color is printed, the tangent point K between the printing roller and the second printing roller when the second color is printed, and the center angle of the arc segment corresponding to the two tangent points.

[0039] Preferably, when the printing length is long, in order to avoid the printing ink from being undried and causing contamination to the printing machine or paper, the printing machine further comprises an adjusting roller as one of the paper conveying rollers, the adjusting roller can move relative to the printing cylinder, and adjust the paper winding length between the tangent points J and K of the printing cylinder and the two printing cylinders respectively during two-color printing. The adjusting roller is parallel to the axis of the printing cylinder, and the two printing cylinders are symmetrically arranged with the plane where the adjusting roller and the swing axis of the printing cylinder are located as the symmetry plane.

[0040] Preferably, the paper winding length between the tangent points J and K between the printing roller and the two printing rollers during two-color printing is nH; wherein n is an integer greater than or equal to 1, H is the moving step length of the traction device, and the distance between the first position and the second position of its paper feed roller is L / 2; and L is the length of a printing plate. The paper winding length between the tangent points J and K between the printing roller and the two printing rollers during two-color printing specifically refers to: the tangent point J between the printing roller and the first printing roller during the first color printing, and the tangent point K between the printing roller and the second printing roller during the second color printing, and the paper winding length from point J to point K according to the paper travel direction.

[0041] Preferably, the printing machine also includes a color mark reading device that moves following the adjustment roller, for reading the positioning color block printed on the paper when printing the first color, so as to obtain the positioning color block offset (the offset can be calculated by pulse counting, for example, it is set to stop after 100 pulses after reading the color mark, and actually stops after 150 pulses after reading the color mark, and the travel distance of 50 pulses is calculated as the positioning color block offset), correcting the start point position of the second printing roller to eliminate the color registration error caused by the cumulative error of the traction step error and the paper tension change.

[0042] Preferably, the position of the starting point of the second printing roller is corrected, specifically:

[0043] According to the formula The correction angle α of the second printing roller is calculated, where α is the correction angle of the second printing roller, β is the offset of the positioning color block, π is the pi, and F is the outer diameter of the second printing roller; the offset β is: the difference between the distance traveled by the positioning color block when the first color is printed after the positioning color block is read by the color mark reading device until the paper stops moving and the set distance, for example, if it is set to stop 3 mm after reading the color mark, and actually stops 3.5 mm after reading the color mark, β=3.5-3=0.5mm.

[0044] The second printing cylinder rotates clockwise (+) or counterclockwise (-) by a correction angle α.

[0045] Preferably, the guiding device comprises:

[0046] A first guide roller group for guiding the paper to be printed to the first color printing area, wherein a paper brake is provided at the paper feeding end;

[0047] The paper after the second color printing is guided to the second guide roller group of the traction device, and the paper outlet end is provided with a paper brake. The two paper brakes are used to brake both the paper feed end and the paper outlet end, and then the paper is pulled by the paper feed roller to reciprocate between the first position and the second position while the paper feed and outlet ends of the printing press remain stationary; the paper feed roller moves between the first position and the second position during the intermittent period of the traction device stepping, driving the paper to reciprocate.

[0048] Preferably, the first printing roller and the second printing roller are mounted on the printing press frame via respective printing roller swinging mechanisms; the printing roller swinging mechanism comprises a printing roller rocker arm rotatably mounted on the printing press frame, the first printing roller or the second printing roller is rotatably mounted on one end of the printing roller rocker arm, and the other end of the printing roller rocker arm is connected to a printing roller rocker arm cylinder for driving the printing roller rocker arm to move so as to realize the first printing roller or the second printing roller swinging relative to the printing roller.

[0049] Preferably, an adjustable limit mechanism is provided on both sides of the end of the printing roller rocker arm, which is used to control the swing amplitude of the printing roller rocker arm so that the paper on the printing roller is close to the printing roller during printing. The structure of the adjustable limit mechanism is exactly the same as the above-mentioned adjustable limit structure, which will not be described in detail here.

[0050] Preferably, the printing press also includes a first inking mechanism arranged in conjunction with the first printing roller and a second inking mechanism arranged in conjunction with the second printing roller; the first and second inking mechanisms can swing relative to the first and second printing rollers respectively, so that the first inking mechanism is close to the first printing roller and makes a counter-rolling motion, and the second inking mechanism is close to the second printing roller and makes a counter-rolling motion, so as to achieve inking.

[0051] Preferably, the first printing roller and the second printing roller are symmetrically arranged with the vertical line where the axis of the printing roller is located as the symmetry axis.

[0052] Preferably, the paper is pulled by the packaging machine and runs synchronously.

[0053] Compared with the prior art, the present invention has the following advantages and effects:

[0054] 1. The structural design of arranging a printing cylinder on each side of the printing cylinder is more compact than the side-by-side and superimposed structures, occupies less space, has a shorter paper winding length, and effectively improves printing efficiency.

[0055] 2. When the paper passes directly around the printing cylinder without passing through the adjustment roller, set the distance between the first position and the second position of the paper feed roller to It ensures that the printing plates of the first color printing and the second color printing are completely overlapped, the color registration accuracy is high, and the paper threading method and paper winding length are simplified.

[0056] 3. By setting the adjustment roller, adjusting the distance between it and the printing cylinder, and adjusting the paper winding length between the tangent points J and K of the printing cylinder and the two printing cylinders during two-color printing, the residence time after printing can be increased to ensure that the ink is dry and avoid contamination of the printing machine or paper by the undried printing ink.

[0057] 4. A color mark reading device is provided which moves following the adjusting roller, and is used to read the position of the positioning color block printed on the paper when printing the first color, so as to measure the offset caused by the change of paper tension and the cumulative error of the moving step length of the packaging machine, and timely adjust the starting point position of the second printing roller to correct the color registration error when printing the second color and improve the color registration accuracy.

[0058] 5. The printing roller is swung to lean against the first printing roller and the second printing roller respectively, and the reciprocating stroke of the paper feed roller in the first position and the second position is used to complete the first color printing and the second color printing respectively, so that the structure of the printing machine is simple and the interval time of two-color printing is extended.

[0059] 6. The two printing rollers are simultaneously attached to the paper on the surface of the printing roller, and the movement of the paper is used to drive the printing roller to rotate, and then the two printing rollers make counter-rolling movements to realize the first color printing and the second color printing respectively. The printing efficiency is high, the error caused by the change of paper tension is effectively reduced, and the registration accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a schematic diagram of the structure of embodiment 1 of the present invention.

[0061] Figure 2 It is a schematic diagram of the structure of the inking mechanism of the present invention.

[0062] Figure 3 It is a structural diagram of embodiment 2 of the present invention.

[0063] Figure 4 It is a schematic diagram of the structure of the adjusting roller, the color mark reading device and the driving mechanism thereof in Embodiment 2 of the present invention.

[0064] Figure 5 It is a structural diagram of embodiment 3 of the present invention. DETAILED DESCRIPTION

[0065] The present invention will be described in detail below with reference to the accompanying drawings.

[0066] Example 1

[0067] like Figure 1 As shown, the present invention is a two-color cylinder printing machine matched with a fixed-step stepping traction device, comprising:

[0068] A guide device for guiding the paper 5 to move forward when the traction device pulls the paper 5 forward;

[0069] A first printing cylinder 2, the rotation of which is driven and controlled by a motor;

[0070] A second printing cylinder 8, the rotation of which is driven and controlled by a motor;

[0071] The printing roller 1 is located between the two printing rollers and can move relative to the two printing rollers;

[0072] The paper feed roller 4 moves between a first position and a second position during the intermittent period of the stepping of the traction device, driving the paper 5 to make a reciprocating motion;

[0073] When the paper feed roller 4 moves from the first position to the second position, the printing roller 1 is attached to the surface of the first printing roller 2 (so that the paper carried on the surface of the printing roller is attached to the surface of the first printing roller), and the movement of the paper 5 drives the printing roller 1 to rotate, and then the printing roller (the first printing roller) is rolled to realize the first color printing; when the paper feed roller 4 moves from the second position to the first position, the printing roller 1 is attached to the surface of the second printing roller 8 (so that the paper carried on the surface of the printing roller is attached to the surface of the second printing roller), and the movement of the paper 5 drives the printing roller 1 to rotate, and then the printing roller (the second printing roller) is rolled to realize the second color printing, and the printing plates of the first color printing and the second color printing are completely overlapped, realizing the two-color printing of the same plate. The structure is compact and occupies little space; the structural design of arranging a printing roller on each side of the printing roller 1 is adopted, and the paper winding length is shorter than the side-by-side and superimposed structures, which effectively improves the printing efficiency.

[0074] Since there is a certain paper winding length between the tangent points J and K of the printing cylinder and the two printing cylinders during two-color printing, in order to ensure that the printing plates of the first color printing and the second color printing completely overlap, the distance between the first position and the second position is Wherein L is the length of a printing plate, π is the circumference of a circle, D is the outer diameter of the printing cylinder 1, and θ is the center angle of the arc segment between the tangent points J and K of the printing cylinder 1 and the two printing cylinders when two-color printing is performed. The center angle of the arc segment between the tangent points J and K of the printing cylinder 1 and the two printing cylinders when two-color printing is performed specifically refers to: the tangent point J between the printing cylinder 1 and the first printing cylinder 2 when the first color is printed, the tangent point K between the printing cylinder 1 and the second printing cylinder 8 when the second color is printed, and the center angle of the arc segment between the two tangent points.

[0075] The guiding device comprises:

[0076] The first guide roller group includes a first guide roller 15, a second guide roller 16, a third guide roller 17 and a fourth guide roller 18 arranged along the traveling direction of the paper 5, and guides the paper to be printed to the first color printing area formed by the printing roller 1 and the first printing roller 2; the first guide roller 15 is provided with a paper brake 6 for cooperating with it to realize braking at the paper feeding end;

[0077] The second guide roller group includes a fifth guide roller 19, a sixth guide roller 20, and a seventh guide roller 21 arranged along the traveling direction of the paper 5, and guides the paper after the second color printing to the traction device; the seventh guide roller 21 is provided with a paper brake 6 for cooperating with it to realize the braking of the paper output end. The paper direction is changed by the cooperation of the guide roller group, which ensures the compactness of the structure.

[0078] The paper feed rollers 4 are two rollers with the same diameter, mounted on the same base and moving with the base, driven by a driving mechanism to make reciprocating linear motion, pulling the paper 5 to make relative motion inside the printing press while the paper inlet and outlet ends are stationary. One of the rollers is installed between the first guide roller 15 and the second guide roller 16, and the other roller is installed between the sixth guide roller 20 and the seventh guide roller 21.

[0079] The printing press also includes a printing roller rocker arm 10 rotatably mounted on the printing press frame (rotatable around a fulcrum C), the printing roller 1 is rotatably mounted on one end of the printing roller rocker arm 10 (can be mounted through a bearing), and the other end of the printing roller rocker arm is connected to a swing arm driving cylinder 9 for driving the printing roller rocker arm 10 to move, thereby controlling the printing roller 1 to swing between the two printing rollers.

[0080] An adjustable limiter 11 is provided at both sides of the end of the printing roller rocker arm 10, which is used to control the swing amplitude of the printing roller rocker arm 10, so that the paper on the printing roller 1 is close to the printing roller during printing, that is, the swinging working positions of the printing roller 1 are respectively against the printing surface of the first printing roller 2 and against the printing surface of the second printing roller 8. The adjustable limiter 11 includes a base 11-1 with a threaded hole and a screw 11-2 threadedly connected to the base. The distance between the end of the screw 11-2 and the end of the printing roller rocker arm 10 is adjusted by rotating the screw 11-2, thereby limiting the swing amplitude of the printing roller rocker arm 10.

[0081] The printing machine also includes a first inking mechanism 3 arranged in conjunction with the first printing roller 2 and a second inking mechanism 7 arranged in conjunction with the second printing roller 8; the first and second inking mechanisms can swing relative to the first and second printing rollers respectively, so that the first inking mechanism 3 is close to the first printing roller 2 and makes a counter-rolling motion, and the second inking mechanism 7 is close to the second printing roller 8 and makes a counter-rolling motion, so as to achieve inking.

[0082] like Figure 2 As shown, the first inking mechanism 3 and the second inking mechanism 7 have exactly the same structure, including an ink pool swing arm 22 rotatably mounted on a printing press frame, an ink pool 23 located on the ink pool swing arm, an ink scraper 24 arranged on the ink pool, an anilox roller 25 located in the ink pool, an ink pool driving cylinder 26 rotatably connected to one end of the ink pool swing arm 22 (away from the ink pool), and an adjustable limiter 27 (whose structure is the same as the adjustable limiter 11) located at one end of the ink pool swing arm 22 (away from the ink pool); the anilox roller 25 is driven to rotate by a motor to bring up the ink in the ink pool 23, and the ink on the surface of the anilox roller 25 is scraped off by the ink scraper 24, and a certain amount of ink is stored in the anilox groove of the anilox roller 25. When inking is required, the ink pool driving cylinder 26 drives the ink pool swing arm 22 to swing, and uses the adjustable limiter 27 to position it so that the anilox roller 25 is close to the printing cylinder (the first printing cylinder or the second printing cylinder) and performs a counter-rolling motion to achieve inking; after inking is completed, the ink pool driving cylinder 26 drives the ink pool swing arm 22 to swing in the opposite direction, so that the anilox roller 25 is separated from the printing cylinder (the first printing cylinder or the second printing cylinder).

[0083] The first printing cylinder 2 and the second printing cylinder 8 are symmetrically arranged with the vertical line where the swing axis of the printing cylinder 1 is located as the symmetry axis.

[0084] The paper 5 is pulled by the packaging machine and runs synchronously.

[0085] The printing surfaces of the characters on the first printing roller 2 and the second printing roller 8 are adsorbed on the printing rollers by magnetic adsorption. At the same time, fine-tuning scale lines are provided on the printing rollers, and the positions of the two prints in the paper width direction can be conveniently fine-tuned by manual adjustment.

[0086] When the traction mechanism of the packaging machine is completed, the paper 5 with a certain tension is pulled forward for a step length, and the two paper brakes 6 are actuated to brake the two ends of the paper 5 entering and exiting the printing press. When the paper feed roller 4 is in the lower position A, the printing roller 1 is driven by the swing arm drive cylinder 9 with the paper 5, and rotates around the fulcrum C through the printing roller rocker arm 10, leaning against the first printing roller 2, and the adjustable limit 11 ensures that the paper to be printed is close to the printing surface of the character plate on the first printing roller 2. When the paper feed roller 4 starts to move upward from the lower position A, the first printing roller 2 rotates synchronously clockwise (the speed of the paper feed roller and the first printing roller is set so that the linear speed of the paper is the same as the linear speed of the character plate printing surface), and the printing roller 1 is driven by the paper 5 to rotate counterclockwise at the same linear speed to ensure that the character plate printing surface and the paper 5 are purely rolling. When the paper feed roller 4 moves to the upper position B, the actual length of the paper movement should be: Wherein L is the length of a printing plate, π is the pi, D is the outer diameter of the printing roller 1, and θ is the center angle of the arc segment between the tangent points J and K of the printing roller 1 and the two printing rollers respectively when performing two-color printing; the first color printing is completed.

[0087] Subsequently, the printing roller 1 is driven by the swing arm driving cylinder 9, rotates around the fulcrum C through the printing roller rocker arm 10, and approaches the second side printing roller 8. The adjustable limit 11 ensures that the paper to be printed on the printing roller is close to the printing surface of the character plate on the second printing roller 8. When the paper feed roller 4 moves downward from the upper position B of the paper feed roller, the second side printing roller 8 rotates synchronously counterclockwise (the speed of the paper feed roller and the second printing roller is set to make the linear speed of the paper the same as the linear speed of the character plate printing surface), and the printing roller 1 is driven by the paper to rotate clockwise at the same linear speed to ensure that the character plate and the paper 5 are purely rolling. When the paper feed roller 4 moves to the lower position A of the paper feed roller, the second color printing is completed. Then the paper brake 6 is released, and the packaging machine can pull the paper 5 forward to run one step.

[0088] When the printing roller 1 approaches the second printing roller 8, the first printing roller 2 rotates in coordination with the action of the first inking mechanism 3 to complete the inking work on the first printing roller 2. The linear speed of the printing surface of the characters on the first printing roller 2 is the same as the linear speed of the anilox roller on the first inking mechanism 3. When the printing roller 1 approaches the first printing roller 2, the second printing roller 8 rotates in coordination with the action of the second inking mechanism 7 to complete the inking work on the second printing roller 8. The linear speed of the printing surface of the characters on the second printing roller 8 is the same as the linear speed of the anilox roller on the second inking mechanism 7.

[0089] Repeating the above actions can achieve online two-color printing of paper when the traction mechanism of the packaging machine stops.

[0090] In this embodiment, the paper 5 completes two printing operations within one cycle of the paper feed roller 4 reciprocating up and down, and the work efficiency is high. And through the setting of the upper position B of the paper feed roller and the lower position A of the paper feed roller, the two printings can be made for the same packaging layout, and the positions of the two printings in the length direction of the paper can be easily fine-tuned, and the color registration accuracy is high.

[0091] According to different printing conditions, the working cycle of the paper feed roller 4 can also start from the paper feed roller upper position B, and the action steps and movement directions of each associated part can be adjusted accordingly.

[0092] In this embodiment, the printing roller 1 can move relative to the two printing rollers; it can also be achieved through the structure of Example 3, that is, the printing roller 1 is fixed in position, and the first printing roller 2 and the second printing roller 8 are arranged on the printing machine frame through a printing roller swing mechanism to achieve the swing of the two printing rollers relative to the printing roller 1; please refer to Example 3 for the specific structure, which will not be repeated here.

[0093] Example 2

[0094] like Figure 3 As shown, this embodiment is basically the same as Embodiment 1, except that:

[0095] The printing press also includes an adjustment roller 13 as one of the conveying rollers for the paper 5. The adjustment roller can move relative to the printing roller 1 to adjust the distance between it and the printing roller 1, and adjust the paper winding length between the tangent points J and K of the printing roller and the two printing rollers respectively during two-color printing. This can increase the residence time after printing, ensure that the ink is dry, and avoid contamination of the printing press or paper by the undried printing ink.

[0096] When two-color printing is performed, the paper winding length between the tangent points J and K of the printing roller 1 and the two printing rollers is nH; where n is an integer greater than or equal to 1, H is the moving step length of the traction device, and the distance between its paper feed roller 4 at position A and position B is L / 2 (that is, the distance between the first position and the second position is L / 2); L is the length of a printing plate. When two-color printing is performed, the paper winding length between the tangent points J and K of the printing roller 1 and the two printing rollers is specifically: the tangent point J between the printing roller 1 and the first printing roller 2 when the first color is printed, the tangent point K between the printing roller 1 and the second printing roller 8 when the second color is printed, and the paper winding length from point J to point K according to the paper travel direction.

[0097] In order to improve the color registration accuracy, the printing machine also includes a color mark reading device 14 that moves with the adjustment roller 13, and is used to read the positioning color block printed on the paper 5 when printing the first color, so as to obtain the positioning color block offset β (that is, the difference between the distance traveled by the positioning color block when the first color is printed after being read by the color mark reading device and the distance traveled by the positioning color block until the paper stops moving and the set distance. For example, it is set to stop 3 mm after reading the color mark, and actually stops 3.5 mm after reading the color mark, β = 3.5-3 = 0.5 mm), and correct the printing start point position of the second printing roller 8 to eliminate the color registration error caused by the cumulative error of the traction step error and the paper tension change.

[0098] The correction of the starting point position of the second printing roller 8 is specifically as follows:

[0099] According to the formula Calculate the correction angle α of the second printing roller 8, where α is the correction angle of the second printing roller 8, β is the offset of the positioning color block, π is the pi, and F is the outer diameter of the second printing roller 8;

[0100] The second printing cylinder 8 is rotated clockwise or counterclockwise by a correction angle α.

[0101] like Figure 4 As shown, the adjusting roller 13 and the color mark reading device 14 are both installed on a slider 28 that can move relative to the printing roller 1. The slider is connected to the power mechanism through a screw nut mechanism 29 and a conveyor belt 30 in turn to achieve the movement of the adjusting roller 13 and the color mark reading device 14 relative to the printing roller 1.

[0102] The end of the printing roller rocker arm 10 is also provided with a reset mechanism 12 that can move relative to the printing roller rocker arm 10. The reset mechanism includes a reset block 12-1 and a power device 12-2 (cylinder and transmission mechanism, only shown in the figure) for driving the reset block 12-1 to reciprocate. A limit arm 12-3 is integrally processed on the reset block 12-1. The limit arm 12-3 and the reset block 12-1 act together on the end of the printing roller rocker arm 10 to realize the reset of the printing roller 1 to the middle position and break away from the contact with the two printing rollers.

[0103] The printing roller 1 can be set to an intermediate stop position through the reset mechanism 12. When the printing press completes two printings (at this time, the printing roller 1 is against the second printing roller on the left), the reset mechanism 12 moves to the end of the printing roller rocker arm 10, and the limit arm 12-3 and the reset block 12-1 act together on the end of the printing roller rocker arm 10. When the paper brake 6 is released, the printing roller 1 is reset to the middle position and has no contact with the printing rollers on both sides. In this way, both the first printing roller 2 and the second printing roller 8 can perform inking work, which can improve the operating efficiency of the entire machine.

[0104] In this embodiment, the printing roller 1 can move relative to the two printing rollers; it can also be achieved through the structure of Example 3, that is, the printing roller 1 is fixed in position, and the first printing roller 2 and the second printing roller 8 are arranged on the printing machine frame through a printing roller swing mechanism to achieve the swing of the two printing rollers relative to the printing roller 1; please refer to Example 3 for the specific structure, which will not be repeated here.

[0105] Example 3

[0106] like Figure 5 As shown, this embodiment is basically the same as Embodiment 2, except that:

[0107] In Example 2, the relative movement between the printing cylinder 1 and the two printing cylinders (the first printing cylinder and the second printing cylinder) is achieved by the swinging of the printing cylinder 1 (the two printing cylinders are stationary); in this embodiment, the printing cylinder 1 is fixed in position, and the first printing cylinder 2 and the second printing cylinder 8 are arranged on the printing machine frame through the printing cylinder swinging mechanism, so that the two printing cylinders can swing relative to the printing cylinder 1. In addition to being able to achieve the functions of Example 2 (of course, since the printing cylinder is fixed, there is no need to achieve the printing cylinder reset function), this embodiment can also achieve the first printing cylinder 2 and the second printing cylinder 8 to be simultaneously attached to the printing cylinder 1, realizing synchronous two-color printing, greatly improving printing efficiency, and effectively reducing the error caused by the change of paper tension, and high registration accuracy.

[0108] The first printing roller 2 and the second printing roller 8 are respectively installed on the printing press frame through their own printing roller swinging mechanisms; the printing roller swinging mechanism includes a printing roller rocker arm 31 rotatably installed on the printing press frame, the first printing roller 2 or the second printing roller 8 is rotatably installed on one end of the printing roller rocker arm 31 (can be installed through a bearing), and the other end of the printing roller rocker arm is connected to a printing roller rocker arm cylinder 33, which is used to drive the printing roller rocker arm 31 to move so as to realize the first printing roller 2 or the second printing roller 8 swinging relative to the printing roller 1.

[0109] An adjustable limit mechanism 32 is provided at each end of the printing roller rocker arm 31, which is used to control the swing amplitude of the printing roller rocker arm 31, so that the paper on the printing roller 1 is closely attached to the characters on the surfaces of the two printing rollers during printing. The structure of the adjustable limit mechanism 32 is exactly the same as that of the aforementioned adjustable limit mechanism 11, and will not be described in detail here.

[0110] When the paper feed roller 4 moves from the first position to the second position, the first printing roller 2 and the second printing roller 8 are simultaneously attached to the paper on the surface of the printing roller 1, and the movement of the paper 5 is used to drive the printing roller 1 to rotate, and then the first printing roller 2 and the second printing roller 8 perform counter-rolling motions to respectively realize the first color printing and the second color printing, and the printing plates of the first color printing and the second color printing completely overlap; when the two printing rollers are detached from the paper on the surface of the printing roller 1, the paper feed roller 4 moves from the second position to the first position and resets; the first printing roller 2 rotates in coordination with the action of the first inking mechanism 3 to complete the inking work on the first printing roller 2; the second printing roller 8 rotates in coordination with the action of the second inking mechanism 7 to complete the inking work on the second printing roller 8; the linear speeds of the printing surfaces of the characters on the two printing rollers are respectively the same as the linear speeds of the anilox rollers on the corresponding inking mechanisms.

[0111] Example 4

[0112] The structure of this embodiment is basically the same as that of embodiment 3, except that:

[0113] The adjustment roller 13, the color mark reading device 14, the slider 28, the screw nut mechanism 29, the conveyor belt 30 and the power mechanism are omitted; the printing length of the first color printing reaches When , the starting printing point of the printed characters on the second printing roller 8 contacts the paper 5 carried on the printing roller 1 to ensure that the printing plates of the first color printing and the second color printing are completely overlapped; where π is the pi, D is the outer diameter of the printing roller 1, and θ is the center angle of the arc segment between the tangent points J and K of the printing roller 1 and the two printing rollers when performing two-color printing.

Claims

1. A two-color cylinder printing machine equipped with a fixed-step stepping traction device, characterized in that include: A guide device for guiding the paper (5) to move forward when the traction device pulls the paper (5) forward, the guide device comprising a first guide roller group and a second guide roller group; the first guide roller group comprises a first guide roller (15), a second guide roller (16), a third guide roller (17) and a fourth guide roller (18) arranged along the moving direction of the paper (5), and guides the paper to be printed to a first color printing area formed by a printing roller (1) and a first printing roller (2); the first guide roller (15) is provided with a paper brake (6) for cooperating with the first guide roller to achieve paper feeding end braking; the second guide roller group comprises a fifth guide roller (19), a sixth guide roller (20) and a seventh guide roller (21) arranged along the moving direction of the paper (5), and guides the paper after the second color printing is completed to the traction device; the seventh guide roller (21) is provided with a paper brake (6) for cooperating with the first guide roller to achieve paper discharge end braking; A first printing cylinder (2); A second printing cylinder (8); A printing roller (1) is located between the two printing rollers and can move relative to the two printing rollers; The paper feed rollers (4) are two rollers with the same diameter, mounted on the same base and moving together with the base, driven by a driving mechanism to make reciprocating linear motion, and move between a first position and a second position during the interval of the stepping of the traction device, driving the paper to make reciprocating motion inside while the paper inlet and outlet ends are stationary, one of the paper feed rollers is mounted between the first guide roller (15) and the second guide roller (16), and the other paper feed roller is mounted between the sixth guide roller (20) and the seventh guide roller (21); During the movement of the paper feed roller (4) from the first position to the second position, the printing roller (1) is attached to the surface of the first printing roller (2), and the movement of the paper (5) drives the printing roller (1) to rotate, thereby performing a counter-rolling motion with the first printing roller to achieve first-color printing; during the movement of the paper feed roller (4) from the second position to the first position, the printing roller (1) is attached to the surface of the second printing roller (8), and the movement of the paper (5) drives the printing roller (1) to rotate, thereby performing a counter-rolling motion with the second printing roller to achieve second-color printing, and the printing plates of the first-color printing and the second-color printing completely overlap.

2. The two-color cylinder printing machine matched with the fixed-step stepping traction device according to claim 1 is characterized in that: The distance between the first position and the second position is Wherein L is the length of a printing plate, π is the circumference of a circle, D is the outer diameter of the printing roller (1), and θ is the center angle of the arc segment between the tangent points J and K of the printing roller (1) and the two printing rollers when performing two-color printing.

3. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 1 is characterized in that: The printing press also includes an adjustment roller (13) as one of the paper (5) conveying rollers, which can be moved relative to the printing cylinder (1).

4. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 3 is characterized in that: When performing two-color printing, the paper winding length between the tangent points J and K of the printing roller (1) and the two printing rollers is nH; wherein n is an integer greater than or equal to 1, H is the moving step length of the traction device; the distance between the first position and the second position of the paper feed roller (4) is L / 2; and L is the length of a printing plate.

5. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 3 is characterized in that: The printing press also includes a color mark reading device (14) that moves following the adjustment roller (13) and is used to read the positioning color block printed on the paper (5) when printing the first color, so as to obtain the positioning color block offset and correct the printing start point position of the second printing roller (8).

6. The two-color cylinder printing machine matched with the fixed-step stepping traction device according to claim 5, characterized in that: Correct the starting point position of the second printing roller (8), specifically: According to the formula Calculating a correction angle α of the second printing roller (8), wherein α is the correction angle of the second printing roller (8), β is the offset of the positioning color block, π is the circumference of a circle, and F is the outer diameter of the second printing roller (8); The second printing cylinder (8) rotates clockwise or counterclockwise through a correction angle α.

7. The two-color cylinder printing machine matched with the fixed-step stepping traction device according to claim 1, characterized in that: The printing press further comprises a printing roller rocker arm (10) rotatably mounted on a printing press frame, the printing roller (1) being rotatably mounted on one end of the printing roller rocker arm (10), the other end of the printing roller rocker arm being connected to a rocker arm driving cylinder (9) for driving the rocker arm to move so as to enable the printing roller (1) to swing between two printing rollers.

8. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 7 is characterized in that: An adjustable limiter (11) is provided on each side of the end of the printing roller rocker arm (10); and a reset mechanism (12) is also provided at the end of the printing roller rocker arm (10) which can move relative to the printing roller rocker arm (10) to force it to reset and disengage from contact with the two printing rollers.

9. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 1, characterized in that: The printing machine further comprises a first inking mechanism (3) matched with the first printing roller (2) and a second inking mechanism (7) matched with the second printing roller (8); the first and second inking mechanisms can swing relative to the first and second printing rollers respectively, so that the first inking mechanism (3) is close to the first printing roller (2) and performs a counter-rolling motion, and the second inking mechanism (7) is close to the second printing roller (8) and performs a counter-rolling motion, so as to achieve inking; The first printing roller (2) and the second printing roller (8) are symmetrically arranged with the vertical line where the swing axis of the printing roller (1) is located as the symmetry axis; The paper (5) is pulled by the packaging machine and runs synchronously.

10. A two-color cylinder printing machine equipped with a fixed-step stepping traction device, characterized in that include: A guide device for guiding the paper (5) to move forward when the traction device pulls the paper (5) forward, the guide device comprising a first guide roller group and a second guide roller group; the first guide roller group comprises a first guide roller (15), a second guide roller (16), a third guide roller (17) and a fourth guide roller (18) arranged along the moving direction of the paper (5), and guides the paper to be printed to a first color printing area formed by a printing roller (1) and a first printing roller (2); the first guide roller (15) is provided with a paper brake (6) for cooperating with the first guide roller to achieve paper feeding end braking; the second guide roller group comprises a fifth guide roller (19), a sixth guide roller (20) and a seventh guide roller (21) arranged along the moving direction of the paper (5), and guides the paper after the second color printing is completed to the traction device; the seventh guide roller (21) is provided with a paper brake (6) for cooperating with the first guide roller to achieve paper discharge end braking; A first printing cylinder (2); A second printing cylinder (8); A printing roller (1) is located between the two printing rollers and can move relative to the two printing rollers; The paper feed rollers (4) are two rollers with the same diameter, mounted on the same base and moving together with the base, driven by a driving mechanism to make reciprocating linear motion, and move between a first position and a second position during the interval of the stepping of the traction device, driving the paper to make reciprocating motion inside while the paper inlet and outlet ends are stationary, one of the paper feed rollers is mounted between the first guide roller (15) and the second guide roller (16), and the other paper feed roller is mounted between the sixth guide roller (20) and the seventh guide roller (21); During the movement of the paper feed roller (4) from the first position to the second position, the two printing rollers simultaneously adhere to the paper on the surface of the printing roller (1), and the movement of the paper (5) drives the printing roller (1) to rotate, thereby performing a counter-rolling movement with the two printing rollers to respectively realize first color printing and second color printing, and the printing plates of the first color printing and the second color printing completely overlap; when the two printing rollers detach from the paper on the surface of the printing roller (1), the paper feed roller (4) moves from the second position to the first position.

11. The two-color cylinder printing machine matched with the fixed-step stepping traction device according to claim 10, characterized in that: The distance between the first position and the second position is Wherein L is the length of a printing plate, π is the circumference of a circle, D is the outer diameter of the printing roller (1), and θ is the center angle of the arc segment between the tangent points J and K of the printing roller (1) and the two printing rollers when performing two-color printing.

12. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 10, characterized in that: The printing length of the first color printing reaches When the printing plate is printed on the second printing roller (8), the starting printing point of the printing plate is in contact with the paper (5) carried on the printing roller (1), so as to ensure that the printing plates of the first color printing and the second color printing completely overlap.

13. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 10, characterized in that: The printing press also includes an adjustment roller (13) as one of the paper (5) conveying rollers, which can be moved relative to the printing cylinder (1).

14. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 13, characterized in that: When performing two-color printing, the paper winding length between the tangent points J and K of the printing roller (1) and the two printing rollers is nH; wherein n is an integer greater than or equal to 1, H is the moving step length of the traction device; the distance between the first position and the second position of the paper feed roller (4) is L / 2; and L is the length of a printing plate.

15. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 13, characterized in that: The printing press also includes a color mark reading device (14) that moves following the adjustment roller (13) and is used to read the positioning color block printed on the paper (5) when printing the first color, so as to obtain the positioning color block offset and correct the printing start point position of the second printing roller (8).

16. The two-color cylinder printing machine matched with the fixed-step stepping traction device according to claim 15, characterized in that: Correct the starting point position of the second printing roller (8), specifically: According to the formula Calculating a correction angle α of the second printing roller (8), wherein α is the correction angle of the second printing roller (8), β is the offset of the positioning color block, π is the circumference of a circle, and F is the outer diameter of the second printing roller (8); The second printing cylinder (8) rotates clockwise or counterclockwise through a correction angle α.

17. The two-color cylinder printing machine matched with the fixed-step stepping traction device according to claim 10, characterized in that: The first printing roller (2) and the second printing roller (8) are both mounted on a printing machine frame via a printing roller swing mechanism; the printing roller swing mechanism comprises a printing roller rocker arm (31) rotatably mounted on the printing machine frame, the first printing roller (2) or the second printing roller (8) is rotatably mounted on one end of the printing roller rocker arm (31), and the other end of the printing roller rocker arm is connected to a printing roller rocker arm cylinder (33) for driving the movement thereof to realize the swing of the first printing roller (2) or the second printing roller (8) relative to the printing roller (1).

18. The two-color cylinder printing machine matched with the fixed-step-length stepping traction device according to claim 17, characterized in that: An adjustable limiting mechanism (32) is respectively provided on both sides of the end of the printing roller rocker arm (31).

19. The two-color cylinder printing machine matched with the fixed-step stepping traction device according to claim 10, characterized in that: The printing machine further comprises a first inking mechanism (3) matched with the first printing roller (2) and a second inking mechanism (7) matched with the second printing roller (8); the first and second inking mechanisms can swing relative to the first and second printing rollers respectively, so that the first inking mechanism (3) is close to the first printing roller (2) and performs a counter-rolling motion, and the second inking mechanism (7) is close to the second printing roller (8) and performs a counter-rolling motion, so as to achieve inking; The first printing roller (2) and the second printing roller (8) are symmetrically arranged with the vertical line where the swing axis of the printing roller (1) is located as the symmetry axis; The paper (5) is pulled by the packaging machine and runs synchronously.

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