Tension device for digital printing machine and digital printing machine

Abstract

The application discloses a tension device and a digital printing machine comprising the same. The tension device comprises: a gravity piece, which is in a strip shape, and the length of the gravity piece is greater than or equal to the width of a printing object; a receiving groove is formed on the gravity piece along the length direction, and the length of the receiving groove is greater than or equal to the width of the printing object; and a fixing piece, which is in a strip shape and is movably installed in the receiving groove; when the fixing piece is installed in the receiving groove, the end of the printing object can be fixed in the receiving groove. The tension device and the digital printing machine comprising the same can start to spray from the end of the printing object, reduce the waste of raw materials and save the cost. Meanwhile, the installation and use are convenient and fast, and the production efficiency is greatly improved. In addition, the stability of the printing object is better through the tension device.

Description

Technical Field

[0001] This invention relates to the field of digital inkjet printing technology, specifically to a tension device for a digital printing machine and a digital printing machine. Background Technology

[0002] Digital printing machines are increasingly widely used in printing processes on fabrics and other products. For example, Chinese invention patent CN107901626A discloses a digital printing machine for double-sided inkjet printing. Unlike printing substrates such as paper, which have a certain degree of rigidity, fabrics and other printing substrates are very soft. Therefore, when printing on fabrics and other printing substrates, a certain tension must be applied to make them flat before the printing operation can be carried out.

[0003] Taking fabric as an example, in existing technologies, applying tension to the fabric is typically achieved through a combination of a feeding device and a take-up device. This involves mounting the fabric roll onto a feeding roller, then passing the fabric end (the end of the fabric) around multiple feeding rollers, then past the printhead, then around multiple take-up rollers, and finally securing it to the take-up roller. Tension is applied to the fabric to make it flat by the feeding roller and take-up roller, or by a combination of both. However, in this approach, tension can only be applied after the fabric is secured to the take-up roller. This results in the initial printing process where the section of fabric from the take-up roller to the printhead cannot be printed, leading to material waste. For expensive materials such as silk, this waste can cause significant losses.

[0004] One existing solution involves using a guide head. This involves sewing a section of inexpensive fabric to the end of the fabric, connecting the fabric to the take-up roller. The length of the guide head ensures that the end of the fabric is positioned precisely at the printhead, allowing printing to begin directly from the end of the fabric. However, this solution has drawbacks: firstly, sewing the guide head to the fabric is cumbersome, and the quality is difficult to guarantee; improper sewing can easily cause weft skew, affecting print quality.

[0005] Furthermore, with the rise of personalized customization, the demand for segmented printing on fabrics is increasing. For example, when people need to customize personalized silk scarves, the pattern needs to be printed on rolls of silk fabric according to the customer's requirements, and then the printed portion is cut off for the next printing. Under this demand, the aforementioned lead-in solution is no longer feasible for practical production. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a tension device for a digital printing machine and a digital printing machine, which provides initial tension to the substrate so that printing can start from the end of the substrate and reduce material waste.

[0007] To solve the above-mentioned technical problems, the present invention provides a tension device for a digital printing machine, comprising:

[0008] A gravity component, which is elongated and its length is greater than or equal to the width of the substrate; a receiving groove is provided on the gravity component along its length, and the length of the receiving groove is greater than or equal to the width of the substrate.

[0009] A fastener, which is elongated and movably installed in the receiving groove; when the fastener is installed in the receiving groove, it can fix the end of the substrate in the receiving groove.

[0010] Furthermore, the cross-section of the gravity component is racetrack-shaped, rounded rectangle, ellipse, or circle.

[0011] Furthermore, one side of the opening of the receiving groove on the gravity member is located on the vertical center line of the cross-section of the gravity member.

[0012] Furthermore, the fastener includes a rod-shaped core and an elastic material covering the outside of the core.

[0013] Furthermore, the core of the fastener is made of glass fiber material.

[0014] Furthermore, the gravity component has a hollow portion, and a counterweight is disposed inside the hollow portion.

[0015] The present invention also provides a digital printing machine, including a feeding mechanism, a receiving mechanism, and a printing head, and also includes the tension device described above.

[0016] Furthermore, the receiving mechanism includes a receiving roller located below the printing head, and the receiving roller has a groove for accommodating the tension device; a sensor for detecting whether the tension device enters the groove is provided inside or on the side of the groove.

[0017] Furthermore, the depth of the groove is matched with the vertical height of the gravity member.

[0018] Furthermore, the length of the gravity component is greater than the width of the substrate, and the digital printing machine also includes two slide rails, which are used to limit the two ends of the gravity component, so that the gravity component slides in the vertical direction.

[0019] Furthermore, it also includes a material transfer device, which includes a material transfer roller and a drive device, the drive device driving the material transfer roller to rotate.

[0020] Furthermore, at least one movable roller is provided above the take-up roller, which can move in the horizontal direction to contact or move away from the vertical substrate.

[0021] The tension device and digital printing machine incorporating the present invention allow printing to begin from the end of the substrate, reducing material waste and saving costs. Furthermore, installation and use are convenient and quick, greatly improving production efficiency. Additionally, the tension device of the present invention improves the stability of the substrate. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an embodiment of the tension device for a digital printing machine according to the present invention.

[0023] Figure 2 yes Figure 1 Cross-sectional view of the embodiment shown.

[0024] Figure 3 yes Figure 1 The illustrated embodiment is shown in the usage state diagram.

[0025] Figure 4 This is a three-dimensional structural schematic diagram of an embodiment of the digital printing machine of the present invention.

[0026] Figure 5 yes Figure 4 A magnified view of a portion of point A in the middle.

[0027] Figure 6 yes Figure 4 A magnified view of a section at point B in the middle.

[0028] Figure 7 yes Figure 4 Side view of the embodiment shown.

[0029] Figure 8 yes Figure 7 A magnified view of a section at point C.

[0030] Figure 9 This is a schematic diagram illustrating the working principle of the material transfer device of the present invention.

[0031] Figure 10 This is a schematic diagram illustrating the working principle of the first movable roller in this invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0033] like Figure 1 and Figure 2 As shown, one embodiment of the tension device for a digital printing machine of the present invention includes:

[0034] Gravity component 1, which is elongated and has a length greater than or equal to the width of the substrate 3; a receiving groove 101 is provided on the gravity component 1 along its length, and the length of the receiving groove 101 is greater than or equal to the width of the substrate 3.

[0035] The fastener 2 is elongated and movably installed in the receiving groove 101. When the fastener 2 is installed in the receiving groove 101, the end of the substrate 3 can be fixed in the receiving groove 101.

[0036] The aforementioned substrate 3 refers to fabric, silk, or other items on which ink is applied to print patterns. In this embodiment, the length of the gravity member 1 is greater than or equal to the width of the substrate 3. For example, when the substrate 3 is fabric, the length of the gravity member 1 is greater than the width of the fabric. In other embodiments, the length of the gravity member 1 may be equal to the width of the substrate 3, depending on the requirements. Generally, the length of the gravity member 1 should not be less than the width of the substrate 3 to ensure that the lower end of the substrate 3 can receive uniform tension. However, under specific requirements, or when the elasticity of the substrate 3 is extremely small, the length of the gravity member 1 may be less than the width of the substrate 3, which is an equivalent design to this invention.

[0037] In this embodiment, the cross-section of the gravity component 1 is racetrack-shaped. In other embodiments, the cross-section of the gravity component 1 can also be a rounded rectangle, ellipse, or circle, as long as its cross-section is basically symmetrical. The advantage of using a racetrack-shaped design in this embodiment is that, since the height of its cross-section is greater than its width, when the end of the substrate 3 is fixed in the receiving groove 101, the gravity component 1 naturally droops under the action of gravity, exhibiting stable balance. To ensure this balance, it is preferred that one side of the opening of the receiving groove 101 on the gravity component is located on the vertical center line of the cross-section of the gravity component 1.

[0038] When using, please refer to Figure 3 First, the end of the substrate 3 is placed into the receiving groove 101 on the gravity member 1. The upward-extending portion of the substrate 3 is close to the side of the vertical center line of the corresponding cross-section of the gravity member 1 in the receiving groove 101. The position of the end of the substrate 3 is adjusted so that the gravity member 1 is in a horizontal state. Then, the fixing member 2 is inserted into the receiving groove 101, and the fixing member 2 is used to press and fix the end of the substrate 3 in the receiving groove 101. Under the action of gravity, the gravity member 1 hangs down naturally, and the gravity of the gravity member 1 provides the initial tension for printing on the substrate 3.

[0039] For a more secure fixation, the fixing member 2 and the receiving groove 101 of the gravity member 1 are preferably interference-fitted. For example... Figure 2As shown, the fixing member 2 includes a rod-shaped core 201 and an elastic material 202 covering the outside of the core 201. The rod-shaped core 201 provides support, while the elastic material 202 covering the outside of the core can deform to a certain extent when the fixing member 2 is inserted into the receiving groove 101, and the elastic force generated by the deformation tightly compresses and fixes the substrate 3. The rod-shaped core 201 is preferably made of a rigid material with a certain toughness, and more preferably of glass fiber. The core made of glass fiber is characterized by its excellent hardness and toughness. Its hardness provides sufficient support strength, while its toughness allows it to deform to a certain extent under external force without easily breaking, and it has no fatigue effect; that is, after the external force disappears, the core made of glass fiber can quickly return to its straight position without permanent deformation.

[0040] Preferably, the gravity component 1 has a hollow part, and a counterweight (not shown in the figure) can be installed inside the hollow part. By adjusting the size, material, or quantity of the gravity component, the weight of the gravity component can be adjusted to adapt to different application scenarios and needs.

[0041] like Figures 4 to 8 As shown, one embodiment of the digital printing machine of the present invention includes a feeding mechanism 4, a receiving mechanism 6, and a print head 5, and also includes a tension device 7, which is the aforementioned tension device. In this embodiment, the feeding mechanism 4 includes a feeding roller 401, two transition rollers 402, a pair of pressure rollers 403, and a positioning roller 404. The substrate unfolds from the feeding roller 401, passes through the two transition rollers 402 and the pair of pressure rollers 403, and its end passes between the pair of pressure rollers 403. Then, the tension device 7 is fixed to the end of the substrate 3 as described above. The end of the substrate 3 connected to the tension device 7 then passes around the positioning roller 404, hangs down naturally, and extends below the print head 5. The positioning roller 404 allows the substrate 3 to be at a suitable distance from the print head 5.

[0042] In this embodiment, the receiving mechanism 6 includes a receiving roller 601, which is located below the printing head 5. The receiving roller 601 has a groove 602 for accommodating the tension device 7. A sensor (not shown in the figure) is provided inside or on the side of the groove 602 to detect whether the tension device 7 enters the groove 602.

[0043] As previously described, printing can begin when the end of the substrate 3 connected to the tension device 7 extends below the print head 5. The gravity of the gravity member 1 provides tension to the substrate 3, keeping it flat to ensure printing quality. As printing proceeds, the end of the substrate gradually moves downward until the tension device 7 falls into the groove 602 on the take-up roller 601. Figure 7The dotted line 'a' in the figure represents the path of the tension device and the substrate. The depth of the groove 602 is preferably matched to the vertical height of the gravity member 1. Thus, when the tension device 7 falls into the groove 602 on the take-up roller 601, the upper end of the tension device 7 is flush with the top of the take-up roller 601, ensuring the roundness of the take-up roller. When the sensor detects that the tension device 7 has entered the groove 602 and is in position, it notifies the control panel (not shown in the figure), which then starts the drive motor of the take-up roller 601. The take-up roller begins to rotate, winding the printed substrate 3 onto the take-up roller 601. The take-up roller simultaneously provides subsequent tension to the substrate. Preferably, the take-up roller and the drive motor are driven by a magnetic powder clutch, which allows control over the tension on the substrate.

[0044] The sensor can be a mechanical sensor, such as a pressure switch installed in the groove. When the tension device falls into the groove, it presses down the switch, thereby triggering a signal. Alternatively, the sensor can be a photoelectric sensor, for example, with a light emitter and a light receiver installed at opposite ends of the groove. When the tension device falls into the groove, it blocks the light between the emitter and receiver, thus triggering a signal.

[0045] In this embodiment, a material transfer device 9 is also included. The material transfer device 9 includes a material transfer roller 901 and a driving device 902, the driving device 902 driving the material transfer roller 901 to rotate. Figure 9 As shown, the function of the transfer device 9 is to rewind the substrate onto the take-up roller after printing is completed, at which time the tension device is also wound into the take-up roller. After the substrate on the take-up roller 601 is transferred to the transfer roller 901 by the transfer device 9, the tension device 7 in the take-up roller 601 and its groove is released for reuse.

[0046] Preferably, the length of the gravity member 1 is set to be greater than the width of the substrate 3, so that both ends of the gravity member 1 extend beyond the substrate 3. The digital printing machine also includes two slide rails 8, which are used to limit the two ends of the gravity member 1, allowing the gravity member 1 to slide in the vertical direction. The slide rails 8 can limit the movement trajectory of the tension device 7, i.e., the end of the substrate, so that the tension device 7 can fall smoothly and accurately into the groove 602 on the take-up roller. At the same time, another function of the slide rails 8 is to prevent the substrate from swaying due to disturbances in the surrounding environment. Since the tension is provided solely by the gravity of the tension device 7 before it enters the take-up roller, if the tension device is not limited, when there are vibration factors in the surrounding environment, such as airflow blowing towards the substrate 3, or the user accidentally touching the substrate 3, the substrate 3 will sway, causing the distance between the substrate 3 and the print head 5 to change, resulting in a decrease in printing quality or even damage to the print head. The slide rails prevent this from happening.

[0047] like Figure 10 As shown, at least one movable roller can also be provided above the take-up roller 601. This movable roller can move horizontally under the action of a cylinder or other power source to contact or move away from the vertical substrate 3. In this embodiment, two movable rollers are provided. The first movable roller 11 is located on the left side of the substrate, while the second movable roller 12 is located on the right side. If the take-up roller 601 rotates counterclockwise, the lower end of the substrate 3 will shift as the roller rotates. At this time, the first movable roller 11 is controlled to move to a position contacting the vertical substrate, thus ensuring that the substrate above it is vertical. Correspondingly, if the take-up roller 601 rotates clockwise, the second movable roller 12 is controlled to move to a position contacting the vertical substrate, ensuring that the substrate above it is vertical.

[0048] Material collection can also be achieved using a collection device in other positions via the first movable roller 11 or the second movable roller 12. In other embodiments, only one movable roller may be provided.

[0049] In addition, in personalized customization applications, the substrate unfolds from the feed roller 401, passes through two transition rollers 402 and a pair of pressure rollers 403, and then its end passes between the pair of pressure rollers 403. The end of the substrate is then placed into the receiving groove 101 on the gravity member. The upward-extending portion of the substrate 3 is close to the side of the vertical center line of the corresponding gravity member cross-section of the receiving groove. The position of the end of the substrate 3 is adjusted so that the gravity member 1 is horizontal. Then, the fixing member 2 is inserted into the receiving groove 101, using the fixing member 2 to press and fix the end of the substrate in the receiving groove. The end of the substrate connected to the tension device then passes around the positioning roller, hangs naturally, and extends below the print head 5, using the gravity of the gravity member to provide initial printing tension. Printing can then begin. After the customized content is printed, the tension device 7 usually has not yet reached the take-up roller 601. At this point, the substrate 3 can be cut off slightly above the printhead using a blade or other tool, and the printed portion removed. Then, the fixing member 2 can be removed from the receiving groove of the gravity member 1, thus separating the tension device 7 from the printed substrate for subsequent processing. The tension device 7 can then be reconnected to the end of the unprinted substrate for printing the next customized content. Because the tension device 7 of this invention is very convenient and quick to install and remove, it greatly improves production efficiency and printing quality compared to existing technologies.

[0050] In other embodiments, the feeding mechanism 4 can be configured as needed, and the present invention does not limit this. For example, more transition rollers can be configured, or no transition rollers can be configured, or a magnetic powder clutch can be used instead of a pressure roller, etc. In this embodiment, two sets of opposite printheads are provided, which can realize simultaneous printing on both sides of the substrate. In other embodiments, only one set of printheads can be provided on one side of the substrate for single-sided printing.

[0051] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A tension device for a digital printing machine, characterized in that, include: A gravity component, which is elongated and its length is greater than or equal to the width of the substrate; a receiving groove is provided on the gravity component along its length, and the length of the receiving groove is greater than or equal to the width of the substrate. The fastener is elongated and movably installed in the receiving groove, and has an interference fit with the receiving groove; when the fastener is installed in the receiving groove, it can fix the end of the substrate in the receiving groove; The gravity component hangs down naturally under the action of gravity, and the gravity of the gravity component provides the initial tension for printing on the substrate.

2. The tension device for a digital printing machine as described in claim 1, characterized in that, The cross-section of the gravity component is racetrack-shaped, rounded rectangle, ellipse, or circle.

3. The tension device for a digital printing machine as described in claim 1, characterized in that, One side of the opening of the receiving groove on the gravity member is located on the vertical center line of the cross-section of the gravity member.

4. The tension device for a digital printing machine as described in claim 1, characterized in that, The fastener includes a rod-shaped core and an elastic material covering the outside of the core.

5. The tension device for a digital printing machine as described in claim 4, characterized in that, The core of the fastener is made of glass fiber material.

6. The tension device for a digital printing machine as described in claim 1, characterized in that, The gravity component has a hollow part, and a counterweight is disposed inside the hollow part.

7. A digital printing machine, comprising a feeding mechanism, a receiving mechanism, and a printing head, characterized in that, It also includes the tension device as described in any one of claims 1-6.

8. The digital printing machine as described in claim 7, characterized in that, The receiving mechanism includes a receiving roller located below the printing head, and the receiving roller has a groove for accommodating the tension device; a sensor for detecting whether the tension device enters the groove is provided inside or on the side of the groove.

9. The digital printing machine as described in claim 8, characterized in that, The depth of the groove matches the vertical height of the gravity component.

10. The digital printing machine as described in claim 7, characterized in that, The length of the gravity component is greater than the width of the substrate. The digital printing machine also includes two slide rails, which are used to limit the two ends of the gravity component so that the gravity component can slide in the vertical direction.

11. The digital printing machine as described in claim 8, characterized in that, It also includes a material transfer device, which includes a material transfer roller and a drive device, the drive device driving the material transfer roller to rotate.

12. The digital printing machine as described in claim 8, characterized in that, At least one movable roller is provided above the take-up roller. The movable roller can move in the horizontal direction to contact or leave the vertically positioned substrate.

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