Digital printing device for packaging box

Abstract

The utility model discloses a packing box digital printing device, relates to the technical field of packing box printing, and aims to solve the technical problem that the printing quality of a current digital printing device on a cylindrical packing box is poor, the packing box digital printing device comprises a rectangular rack, an adjusting frame is arranged on one side of the top of the rectangular rack, and a digital printing device main body is arranged in the adjusting frame. The adjusting structure is arranged on the placing plate, the two groups of roll shafts are arranged on the adjusting structure, one group of roll shafts is the driving roll shaft, the other group of roll shafts is the driven roll shaft, and the two groups of roll shafts are symmetrically distributed along the horizontal axis, so that when digital printing is carried out on the cylindrical packaging box, personnel can carry out digital printing on the cylindrical packaging box according to the size of the cylindrical packaging box. The distance between the two sets of roll shafts is adjusted through the adjusting structure, then the cylindrical packaging box is placed between the two sets of roll shafts, and at the moment, it can be guaranteed that the cylindrical packaging box is stably placed and does not roll front and back.

Description

Technical Field

[0001] This utility model relates to the field of packaging box printing technology, and more specifically, to a digital printing device for packaging boxes. Background Technology

[0002] In the modern product packaging industry, packaging boxes play a crucial role. They not only protect the goods but also serve to promote and beautify them. In the production process of packaging boxes, digital printing is required, which necessitates the use of digital printing equipment.

[0003] A search revealed a Chinese utility model patent with publication number "CN216804854U" that discloses a digital printing device for anti-counterfeiting watermarks on packaging boxes. This device reduces the power consumption of the first telescopic rod by converting the sliding friction of the placement plate into rolling friction. Furthermore, a placement groove is provided on the placement plate. When watermarking or printing, the packaging box is placed in the placement groove. Compared with existing devices, the packaging box is not left unsupported, resulting in better watermark or digital printing quality and clearer results.

[0004] While the aforementioned documents can achieve digital printing of packaging boxes, if the packaging box is cylindrical and digital printing needs to be performed on the curved surface of the cylindrical packaging box, the uneven distance between the curved surface of the cylindrical packaging box and the printing head will result in uneven ink spraying volume or pressure, causing blurry or distorted text and patterns, thus affecting the quality of digital printing. In view of this, we propose a digital printing device for packaging boxes. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology, adapt to the needs of reality, and provide a digital printing device for packaging boxes to solve the technical problem of poor printing quality of cylindrical packaging boxes by current digital printing devices.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a digital printing device for packaging boxes, including a rectangular frame, an adjustment frame arranged on one side of the top of the rectangular frame, a main body of the digital printing device arranged inside the adjustment frame, a placement plate slidably arranged inside the rectangular frame, a first driving structure arranged inside the rectangular frame, an adjustment structure arranged on the top side of the placement plate facing away from the adjustment frame, two sets of rollers rotatably arranged on the adjustment structure facing the adjustment frame, the two sets of rollers being symmetrically distributed along a horizontal axis, one set of rollers being the driving rollers and the other set being the driven rollers, and a second motor corresponding to the driving rollers being arranged on the adjustment structure;

[0007] The roller shaft has a drum-shaped structure with a middle diameter larger than the diameters at both ends, and the height of the drum protrusion is between 0.5-1mm. The surface of the roller shaft adopts a rounded transition, and an anti-slip elastic sleeve is arranged on the roller shaft. The center distance between the two sets of roller shafts is 1.2-1.5 times the minimum diameter of the cylindrical packaging box.

[0008] Preferably, two sets of guide rails are symmetrically arranged inside the rectangular frame, and the placement plate has slots corresponding to the guide rails. The slots are inserted into the guide rails, and several sets of equidistant balls are movably arranged at the top and bottom of the slots.

[0009] Preferably, the adjustment frame includes a concave bracket arranged on a rectangular platform. Mounting rods are inserted at both ends of the top of the concave bracket. A mounting plate is arranged at one end of the mounting rod that extends into the interior of the concave bracket. The main body of the digital printing device is arranged on the mounting plate. An electro-hydraulic push rod is arranged at the center of the top of the concave bracket. The piston end of the electro-hydraulic push rod is connected to the main body of the digital printing device.

[0010] Preferably, the first drive structure includes a first motor and a one-way lead screw. The one-way lead screw is rotatably arranged inside a rectangular frame and passes through a placement plate. The first motor is arranged on one side of the rectangular frame, and the rotation shaft of the output end of the first motor is connected to one end of the one-way lead screw.

[0011] Preferably, the adjustment structure includes a welding plate, which is vertically arranged on the placement plate. A rectangular hole is opened on the surface of the welding plate. Two sets of symmetrical I-shaped sliders are slidably arranged in the rectangular hole. The roller shaft is rotatably arranged in the center of one side of the I-shaped slider. The second motor is arranged on the other side of one set of I-shaped sliders, and the rotation shaft of the output end of the second motor is connected to the active roller shaft. A second drive structure is arranged in the rectangular hole.

[0012] Preferably, the second drive structure includes a third motor and a bidirectional lead screw. The third motor is rotatably arranged in a rectangular hole, and the bidirectional lead screw is arranged on a welding plate. The rotation shaft at the output end of the bidirectional lead screw is connected to the third motor.

[0013] Preferably, the anti-slip elastic sleeve is made of silicone, and the surface of the anti-slip elastic sleeve is provided with anti-slip texture.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This utility model incorporates an adjustment structure on a placement plate, featuring two sets of rollers: one active roller and the other passive roller, symmetrically distributed along a horizontal axis. Therefore, during digital printing of cylindrical packaging boxes, operators can adjust the distance between the two sets of rollers according to the box's size, placing the box between them. This ensures the box remains stable and doesn't roll back and forth. When the placement plate moves the box to the printing head below the main body of the digital printing device, a second motor drives the active roller to rotate. With the assistance of the passive roller, the box rotates, ensuring its curved surface passes evenly over the printing head, maintaining a constant distance between the printing head and the curved surface. This eliminates printing deviations caused by the curvature of the curved surface, guaranteeing high-quality digital printing of the cylindrical packaging box and solving the current technical problem of poor printing quality for cylindrical packaging boxes in digital printing devices. Therefore, this utility model offers superior digital printing quality for cylindrical packaging boxes.

[0016] 2. The two sets of rollers in this utility model are designed as drum-shaped structures with a slightly larger diameter in the middle and slightly smaller diameters at both ends. The height of the drum protrusion is between 0.5-1mm. The center distance between the two sets of rollers is 1.2-1.5 times the minimum diameter of the cylindrical packaging box. The rollers are provided with anti-slip elastic sleeves. This structure can generate an axial component force towards the center when the cylindrical packaging box rotates, automatically correcting any possible axial displacement trend. In addition, the surface of the drum-shaped rollers adopts a rounded transition (not a zigzag transition) to ensure uniform friction when the rollers contact the packaging box, avoiding sudden changes in local stress. Thus, the drum-shaped rollers with the rounded transition can effectively prevent the packaging box from shifting back and forth when rotating, ensuring the accuracy of the printing position and further guaranteeing the digital printing quality of the cylindrical packaging box. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the placement plate structure of this utility model;

[0019] Figure 3 This is a schematic diagram of the adjustment structure of this utility model;

[0020] Figure 4 This is a schematic diagram of the roller structure of this utility model;

[0021] Figure 5 This is a cross-sectional structural diagram of the present invention;

[0022] Figure 6 This is a schematic diagram illustrating the application of digital printing on cylindrical packaging boxes according to this utility model.

[0023] Explanation of the labels in the diagram:

[0024] 1. Rectangular frame; 101. Guide rail; 2. Adjustment frame; 201. Concave bracket; 202. Mounting rod; 203. Mounting plate; 204. Electro-hydraulic push rod; 3. Main body of digital printing device; 4. Placement plate; 401. Groove; 402. Ball bearing; 5. First drive structure; 501. First motor; 502. One-way lead screw; 6. Adjustment structure; 7. Roller; 701. Anti-slip elastic sleeve; 8. Second motor; 9. Welding plate; 901. Rectangular hole; 10. I-shaped slider; 11. Second drive structure; 1101. Third motor; 1102. Two-way lead screw. Detailed Implementation

[0025] like Figures 1 to 6 As shown, this utility model relates to a digital printing device for packaging boxes, including a rectangular frame 1. An adjustment frame 2 is arranged on one side of the top of the rectangular frame 1. The main body of the digital printing device 3 is arranged inside the adjustment frame 2. The main body of the digital printing device 3 is based on the digital printing device in the digital printing device for anti-counterfeiting watermark of packaging boxes disclosed in Chinese utility model with announcement number "CN216804854U". It is the prior art. A placement plate 4 is slidably arranged inside the rectangular frame 1. A first driving structure 5 is arranged inside the rectangular frame 1. An adjustment structure 6 is arranged on the top of the placement plate 4 on the side away from the adjustment frame 2. Two sets of rollers 7 are rotatably arranged on the adjustment structure 6 facing the adjustment frame 2. The two sets of rollers 7 are symmetrically distributed along the horizontal axis. One set of rollers 7 is the active roller, and the other set of rollers 7 is the driven roller. A second motor 8 corresponding to the active roller is arranged on the adjustment structure 6.

[0026] When digitally printing on cylindrical packaging boxes, the operator can adjust the distance between the two sets of rollers 7 using the adjusting structure 6 according to the size of the cylindrical packaging box. Then, the cylindrical packaging box is placed between the two sets of rollers 7, ensuring that the cylindrical packaging box is stably placed and will not roll back and forth. Then, the first drive structure 5 is controlled to move the placement plate 4, which in turn moves the cylindrical packaging box on the placement plate 4 to the printing head below the main body 3 of the digital printing device for digital printing. The height of the main body 3 of the digital printing device can be adjusted as needed using the adjusting frame 2. Then, the second motor 8 drives the active roller to rotate, and with the cooperation of the driven roller, the cylindrical packaging box can be rotated, so that the curved surface of the cylindrical packaging box passes evenly over the printing head below the main body 3 of the digital printing device, maintaining a constant distance between the printing head and the curved surface, eliminating printing deviations caused by the curvature of the curved surface, and ensuring the quality of digital printing of the cylindrical packaging box.

[0027] Specifically, two sets of guide rails 101 are symmetrically arranged inside the rectangular frame 1. The placement plate 4 has a slot 401 corresponding to the guide rail 101. The slot 401 is inserted into the guide rail 101. Several sets of equidistant balls 402 are movably arranged at the top and bottom of the slot 401. With the cooperation of the guide rail 101 and the slot 401, the placement plate 4 can slide inside the rectangular frame 1. The balls 402 can reduce the friction generated by the movement of the placement plate 4 and ensure the smooth sliding of the placement plate 4.

[0028] Furthermore, the adjustment frame 2 includes a concave bracket 201, which is arranged on the rectangular platform 1. Mounting rods 202 are inserted at both ends of the top of the concave bracket 201. A mounting plate 203 is arranged at one end of the mounting rod 202 that extends into the interior of the concave bracket 201. The main body 3 of the digital printing device is arranged on the mounting plate 203. An electro-hydraulic push rod 204 is arranged at the center of the top of the concave bracket 201. The piston end of the electro-hydraulic push rod 204 is connected to the main body 3 of the digital printing device. The electro-hydraulic push rod 204 can drive the mounting plate 203 to rise and fall, thereby realizing the adjustment of the height of the main body 3 of the digital printing device.

[0029] Furthermore, the first drive structure 5 includes a first motor 501 and a one-way lead screw 502. The one-way lead screw 502 is rotatably arranged inside the rectangular platform 1 and passes through the placement plate 4. The first motor 501 is arranged on one side of the rectangular platform 1, and the rotation shaft at the output end of the first motor 501 is connected to one end of the one-way lead screw 502. The first motor 501 drives the one-way lead screw 502 to rotate, which in turn drives the placement plate 4 to move.

[0030] It is worth noting that the adjustment structure 6 includes a welding plate 9, which is vertically arranged on the placement plate 4. A rectangular hole 901 is opened on the surface of the welding plate 9. Two sets of symmetrical I-shaped sliders 10 are slidably arranged in the rectangular hole 901. A roller shaft 7 is rotatably arranged in the center of one side of the I-shaped sliders 10. A second motor 8 is arranged on the other side of one set of I-shaped sliders 10, and the rotation shaft of the output end of the second motor 8 is connected to the active roller shaft. A second drive structure 11 is arranged in the rectangular hole 901. The second drive structure 11 includes a third motor 1101 and a bidirectional lead screw 1102. The third motor 1101 is rotatably arranged in the rectangular hole 901, and the bidirectional lead screw 1102 is arranged on the welding plate 9. The rotation shaft of the output end of the bidirectional lead screw 1102 is connected to the third motor 1101. The third motor 1101 drives the bidirectional lead screw 1102 to rotate, and then the two sets of I-shaped sliders 10 on the bidirectional lead screw 1102 synchronously move relative to each other or in opposite directions in the rectangular hole 901, thereby adjusting the distance between the two sets of roller shafts 7.

[0031] In the embodiments of this utility model, the roller 7 has a drum-shaped structure with a middle diameter larger than the diameters at both ends. The middle diameter of the roller 7 is slightly larger and the diameters at both ends are slightly smaller. The height of the drum-shaped protrusion is between 0.5-1mm. The surface of the roller 7 adopts a rounded transition. An anti-slip elastic sleeve layer 701 is arranged on the roller 7. The center distance between the two sets of rollers 7 is 1.2-1.5 times the minimum diameter of the cylindrical packaging box.

[0032] The drum-shaped roller 7 can generate an axial force towards the center when the cylindrical packaging box rotates, automatically correcting any possible axial displacement trend. Furthermore, the rounded transition surface of the drum-shaped roller 7 ensures uniform friction when the roller 7 contacts the packaging box, avoiding sudden changes in local stress. Thus, the rounded transition drum-shaped roller 7 can effectively prevent the packaging box from shifting back and forth when rotating, ensuring the accuracy of the printing position and further guaranteeing the digital printing quality of the cylindrical packaging box.

[0033] The contact area between the drum-shaped roller 7 and the cylindrical packaging box needs to be explained here:

[0034] Contour of the drum-shaped roller 7: The roller 7 is a symmetrical curved surface with a large diameter in the middle (denoted as D_{\text{max}}\) and small diameters at both ends (denoted as D_{\text{min}}=D_{\text{max}}-2h\), where h is the height of the protrusion, 0.5-1mm. It usually adopts a circular arc transition (non-abrupt broken line), and the surface equation can be approximated as a parabola or a circular arc.

[0035] Tubular packaging box diameter matching: Let the outer diameter of the packaging box be d, and the center distance between the two sets of rollers be L (as designed above, \(1.2-1.5d_{\text{min}}\), where \(d_{\text{min}}\) is the minimum packaging box diameter). When the packaging box is placed between the two sets of rollers 7, the contact point between the rollers and the packaging box is located at a certain position on the drum-shaped curved surface, rather than just at the middle point.

[0036] For standard diameter packaging boxes (close to the center diameter of roller 7): the contact area is the arc-shaped surface in the middle of roller 7, and the contact length accounts for about 60%-80% of the axial length of roller 7, forming a surface contact (rather than a point contact). The anti-slip elastic sleeve 701 will undergo local deformation due to pressure, so that the contact area expands from "line contact" to "surface contact" (contact width about 3-5mm). Even if the middle of roller 7 is slightly higher, the elastic deformation can ensure the continuity of the contact area and avoid suspension.

[0037] For smaller diameter packaging boxes: the contact points are shifted to both ends of roller 7, but due to the gradual change characteristics of the drum-shaped curved surface, the contact area is still a continuous arc surface, and the diameter at both ends \(D_{\text{min}}\) is still greater than 1 / 2 of the diameter of the packaging box (to avoid suspension).

[0038] Therefore, the cylindrical packaging box can be stably placed between the two sets of rollers 7, and the two sets of rollers 7 can stably drive the cylindrical packaging box to rotate.

[0039] Specifically, the anti-slip elastic sleeve 701 is made of silicone, and the surface of the anti-slip elastic sleeve 701 is provided with anti-slip texture; the silicone anti-slip elastic sleeve 701 with anti-slip texture can improve friction and ensure that the roller 7 can stably drive the packaging box to rotate when it rotates.

[0040] Working Principle: This embodiment provides a digital printing device for packaging boxes. First, when digitally printing on a cylindrical packaging box, the operator can adjust the distance between the two sets of rollers 7 according to the size of the cylindrical packaging box by adjusting the structure 6. Then, the cylindrical packaging box is placed between the two sets of rollers 7. At this time, it can be ensured that the cylindrical packaging box is placed stably and will not roll back and forth. Then, the first drive structure 5 is controlled to drive the placement plate 4 to move. Then, the cylindrical packaging box on the placement plate 4 is moved to the printing head below the main body 3 of the digital printing device for digital printing. The height of the main body 3 of the digital printing device can be adjusted as needed by adjusting the frame 2. Then, the second motor 8 drives the active roller to rotate. Then, with the cooperation of the driven roller, the cylindrical packaging box can be rotated so that the curved surface of the cylindrical packaging box passes evenly through the printing head below the main body 3 of the digital printing device, keeping the distance between the printing head and the curved surface constant, eliminating printing deviations caused by the curvature of the curved surface, and ensuring the quality of digital printing of the cylindrical packaging box.

[0041] Secondly, the drum-shaped roller 7 can generate an axial force towards the center when the cylindrical packaging box rotates, automatically correcting any possible axial displacement trend. Furthermore, the rounded transition surface of the drum-shaped roller 7 ensures uniform friction when the roller 7 contacts the packaging box, avoiding sudden changes in local stress. Thus, the rounded transition drum-shaped roller 7 can effectively prevent the packaging box from shifting forward or backward when rotating, ensuring the accuracy of the printing position and further guaranteeing the digital printing quality of the cylindrical packaging box.

[0042] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of this utility model based on the above embodiments and make different extensions and variations. However, as long as they do not depart from the spirit of this utility model, they are all within the protection scope of this utility model.

Claims

1. A digital printing apparatus for packaging boxes, characterized in that, The device includes a rectangular frame (1), an adjustment frame (2) is arranged on one side of the top of the rectangular frame (1), a digital printing device body (3) is arranged inside the adjustment frame (2), a placement plate (4) is slidably arranged inside the rectangular frame (1), a first drive structure (5) is arranged inside the rectangular frame (1), an adjustment structure (6) is arranged on the side of the top of the placement plate (4) facing away from the adjustment frame (2), two sets of rollers (7) are rotatably arranged on the adjustment structure (6) facing the adjustment frame (2), the two sets of rollers (7) are symmetrically distributed along the horizontal axis, one set of rollers (7) is the active roller, the other set of rollers (7) is the driven roller, and a second motor (8) corresponding to the active roller is arranged on the adjustment structure (6). The roller (7) has a drum-shaped structure with a middle diameter larger than the diameters at both ends, and the height of the drum protrusion is between 0.5-1mm. The surface of the roller (7) adopts a rounded transition. The roller (7) is provided with an anti-slip elastic sleeve (701). The center distance between the two sets of rollers (7) is 1.2-1.5 times the minimum diameter of the cylindrical packaging box.

2. The packaging box digital printing device according to claim 1, characterized in that, The rectangular frame (1) has two sets of guide rails (101) symmetrically arranged inside. The placement plate (4) has a slot (401) corresponding to the guide rail (101). The slot (401) is inserted into the guide rail (101). Several sets of equidistant balls (402) are movably arranged at the top and bottom of the slot (401).

3. The packaging box digital printing device according to claim 1, characterized in that, The adjustment frame (2) includes a concave bracket (201), which is arranged on a rectangular platform (1). Mounting rods (202) are inserted at both ends of the top of the concave bracket (201). A mounting plate (203) is arranged at one end of the mounting rod (202) that extends into the interior of the concave bracket (201). The main body (3) of the digital printing device is arranged on the mounting plate (203). An electric hydraulic push rod (204) is arranged at the center of the top of the concave bracket (201). The piston end of the electric hydraulic push rod (204) is connected to the main body (3) of the digital printing device.

4. The packaging box digital printing device according to claim 1, characterized in that, The first drive structure (5) includes a first motor (501) and a one-way lead screw (502). The one-way lead screw (502) is rotatably arranged inside the rectangular frame (1) and passes through the placement plate (4). The first motor (501) is arranged on one side of the rectangular frame (1), and the rotation shaft of the output end of the first motor (501) is connected to one end of the one-way lead screw (502).

5. The packaging box digital printing device according to claim 1, characterized in that, The adjustment structure (6) includes a welding plate (9), which is vertically arranged on the placement plate (4). A rectangular hole (901) is provided on the surface of the welding plate (9). Two sets of symmetrical I-shaped sliders (10) are slidably arranged in the rectangular hole (901). The roller shaft (7) is rotatably arranged in the center of one side of the I-shaped slider (10). The second motor (8) is arranged on the other side of one set of I-shaped sliders (10), and the rotation shaft of the output end of the second motor (8) is connected to the active roller shaft. A second drive structure (11) is arranged in the rectangular hole (901).

6. The packaging box digital printing apparatus according to claim 5, characterized in that, The second drive structure (11) includes a third motor (1101) and a bidirectional lead screw (1102). The third motor (1101) is rotatably arranged in a rectangular hole (901), and the bidirectional lead screw (1102) is arranged on a welding plate (9). The rotation shaft at the output end of the bidirectional lead screw (1102) is connected to the third motor (1101).

7. The packaging box digital printing apparatus according to claim 1, characterized in that, The anti-slip elastic sleeve (701) is made of silicone, and the surface of the anti-slip elastic sleeve (701) is provided with anti-slip texture.

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