Constant-pressure and constant-speed doctor blade mechanism for pyrography printing

Abstract

The constant-pressure and constant-speed doctor blade mechanism comprises a support and a rigid knife rest, a mounting frame is movably mounted on the inner side of one end of the support, two mounting strips are fixedly mounted on the back face of the mounting frame, and mounting plates are fixedly mounted at the two ends of the mounting frame; the two ends of the support are in threaded connection with limiting columns, and the outer sides of the limiting columns are movably sleeved with hydraulic synchronous telescopic rods through supporting rings. When fine adjustment is needed, the control system synchronously and accurately controls the telescopic amount of the high-precision telescopic rod and the electromagnetic strength of the first electromagnet, so that the electromagnetic adjustment effect is generated between the auxiliary spring and the first electromagnet, the first piston and the supporting column are pushed to change the position, and then the limiting barrel and the rigid tool rest are pushed out; further, the gap between the flexible liner and the doctor blade body relative to the ink transfer roller is changed, the attaching position of the doctor blade body is changed, the purpose of fine adjustment is achieved, the adjustment precision is high, and response is rapid.

Description

Technical Field

[0001] This invention relates to the field of heat transfer printing technology, specifically to a constant pressure and constant speed doctor blade mechanism for heat transfer printing. Background Technology

[0002] The doctor blade mechanism is a core component in printing equipment (especially gravure, flexographic, and heat transfer printing) that controls ink transfer. It consists of a rigid blade holder, a flexible doctor blade, and supporting devices such as pressure adjustment, angle adjustment, axial movement, and clutch pressure. By adhering to the surface of the printing plate roller or anilox roller at a constant angle and pressure, the blade's flexibility adapts to the roller surface, precisely scraping away excess ink and retaining only a fixed amount of ink within the cells. At the same time, the blade's movement optimizes the uniformity of blade wear, and with constant pressure and speed control, it achieves stable ink layer output. It is a key component to ensure clear printed patterns, uniform ink color, and avoid defects such as blade streaks and plate fogging.

[0003] The doctor blade mechanism is a core component in printing equipment that controls ink transfer. It needs to scrape off excess ink from the outside of the ink transfer roller to achieve the parameters required for printing. However, existing doctor blade mechanisms usually suffer from uneven pressure adjustment across the entire width, often using single-point / end-point pressure adjustment, and insufficient distance adjustment precision. This makes it difficult to detect localized wear of the doctor blade or sudden damage that causes pressure changes, leading to incomplete scraping, blade streaks, and uneven ink color in the lateral direction during printing. This results in the need for machine shutdown for adjustment, complex structure that is difficult to disassemble and clean, and low efficiency. Based on this, a constant pressure and constant speed doctor blade mechanism for heat transfer printing is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a constant pressure and constant speed doctor blade mechanism for heat transfer printing, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a constant pressure and constant speed squeegee mechanism for heat transfer printing, comprising a bracket and a rigid blade holder. A mounting bracket is movably mounted on the inner side of one end of the bracket. Two mounting strips are fixedly mounted on the back of the mounting bracket. Mounting plates are fixedly mounted on both ends of the mounting bracket. Limiting posts are threadedly connected to both ends of the bracket. A hydraulic synchronous telescopic rod is movably sleeved on the outer side of the limiting post via a support ring. A movable clamp mechanism is fixedly mounted on the output end of the hydraulic synchronous telescopic rod. An angle limiting plate is fixedly mounted on the opposite end of the limiting post via bolts. The angle limiting plate has several limiting mounting holes inside. Several support cylinders are fixedly installed on one side of the mounting frame. A high-precision telescopic rod is fixedly installed on the inner side of the support cylinder. An electromagnet is fixedly installed at the output end of the high-precision telescopic rod. An auxiliary spring is sleeved on the outer side of the high-precision telescopic rod. A piston is movably sleeved on the inner side of the support cylinder. A permanent magnet is fixedly installed on one side of the piston. A support column is fixedly installed on one side of the piston. An installation groove is opened inside one end of the support column. An electromagnet is fixedly installed in the middle of the installation groove. A return spring is sleeved on the outer side of both ends of the electromagnet. A permanent magnet is fixedly installed on the opposite end of the return spring. A pin is fixedly installed on the opposite side of the permanent magnet.

[0006] The movable clamp mechanism includes a semi-ring clamp one and a semi-ring clamp two. The inner sides of the semi-ring clamp one and the semi-ring clamp two are fixedly installed with mounting seats. Several side balls are rolled on both sides of the mounting seats. Several main balls are rolled on the inner side of the opposite side of the mounting seats. Two concave collars are movably sleeved on the outer side of the mounting seats.

[0007] A number of limiting cylinders are fixedly installed on one side of the rigid tool holder. Limiting holes are opened at the top and bottom of the limiting cylinders. A flexible pad is movably installed on the inner side of the rigid tool holder. A doctor blade body is fixedly installed inside the flexible pad. A number of strain gauges are attached to the bottom of the doctor blade body. A number of strain gauges are fixedly installed inside the flexible pad.

[0008] Preferably, the top of the bracket and the mounting frame are fixedly connected by bolts, the top and bottom of the bracket are fixedly installed with limit strips, the mounting plate is fixedly installed at both ends of the mounting frame by bolts, the mounting strips and the mounting plate are provided with a number of mounting holes, and one side of the bracket is provided with a groove that matches the mounting frame.

[0009] Preferably, one side of the second semi-ring is fixedly connected to the output end of the hydraulic synchronous telescopic rod, the bottom ends of the first and second semi-rings are connected by a hinge seat, and the top ends of the first and second semi-rings are fixedly connected by bolts. The main ball and the side ball are both rolled inside the mounting seat through ball grooves. The main ball and the side ball are evenly distributed circumferentially on the outer wall of the mounting seat, and the inner sides of the two concave collars are in rolling contact with the main ball and the side ball.

[0010] Preferably, the limiting mounting holes are evenly distributed circumferentially inside the angle limiting plate, the outer side of the limiting post is movably sleeved with a limiting ring one, the outer side of the limiting post is movably sleeved with a limiting ring two, the limiting ring one is located on the opposite side of the angle limiting plate and the hydraulic synchronous telescopic rod, and the limiting ring two is located on the opposite side of the bracket and the hydraulic synchronous telescopic rod.

[0011] Preferably, one end of the auxiliary spring is fixedly installed inside the support cylinder, and the other end of the auxiliary spring is fixedly installed on one side of the first permanent magnet. The opposite ends of the first electromagnet and the first permanent magnet are distributed with the same poles repelling each other. The support column is movably sleeved inside the support cylinder. A permanent magnet ring is fixedly sleeved on the outside of the support cylinder. The permanent magnet ring and the support cylinder are linearly and evenly distributed on one side of the mounting frame.

[0012] Preferably, the dimensions of the support cylinder are adapted to the dimensions of the limiting cylinder, the inside of the bracket is provided with slots adapted to the permanent magnet ring and the support cylinder, the inside of one side of the bracket is provided with slots adapted to the limiting cylinder, the dimensions of the support cylinder and the support column are adapted to the dimensions of the limiting cylinder, and the limiting cylinder is linearly and uniformly distributed on one side of the rigid tool holder.

[0013] Preferably, the opposite end of the reset spring is fixedly installed on the outer side of the middle part of the electromagnet two by a support frame, the permanent magnet two and the electromagnet two are distributed at opposite ends, the specifications and dimensions of the pin are adapted to the specifications and dimensions of the limiting hole, the pin moves through the mounting groove and extends to the outer side of the support column, and one end of the support column abuts against the outer side of the rigid tool holder.

[0014] Preferably, strain gauge one is linearly and uniformly distributed at the bottom of the doctor blade body, and strain gauge two is linearly and uniformly attached to the top and bottom of the doctor blade body. The positions of strain gauge one and strain gauge two correspond to the positions of the limiting cylinder. The flexible pad is made of one of the following materials: modified polyester-type cast polyurethane, polyester-type cast polyurethane, thermoplastic polyurethane, and high-elasticity nitrile rubber.

[0015] Preferably, the flexible pad is fixedly installed on the inner side of the rigid blade holder by bolts, and a slot adapted to the rigid blade holder is provided on one side of the bracket. The flexible pad and the doctor blade body are located in the middle of the bracket and the rigid blade holder.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. When fine adjustment is required, the device synchronously and precisely controls the extension and retraction of the high-precision telescopic rod and the electromagnetic strength of the electromagnet one through the control system, thereby generating an electromagnetic adjustment effect between the auxiliary spring and the electromagnet one, thereby pushing the piston one and the support column to change position, thereby causing the limiting cylinder and the rigid blade holder to be pushed out, thereby causing the gap between the flexible pad and the doctor blade body relative to the ink roller to change and the contact position of the doctor blade body to change, thus achieving the purpose of fine adjustment, with high adjustment accuracy and rapid response; 2. When the doctor blade body experiences wear and tear, the strain signals of strain gauge 1 and strain gauge 2 relative to the bending of the doctor blade body change. The deformation of the flexible pad under pressure changes, causing both strain gauge 1 and strain gauge 2 to reflect the strain signal. When the control system receives the signal, it precisely controls electromagnet 1 and high-precision telescopic rod to adjust the position of the rigid blade holder and doctor blade body, achieving high precision and fast response, and reducing horizontal lines, ink streaks, and blade filaments during doctoring. 3. When disassembly or assembly is required, the second electromagnet is activated to generate magnetic force, and the two ends generate magnetic attraction force on the second permanent magnet, causing the second permanent magnet and the pin to retract. This causes the pin to slide away from the position of the limiting hole, thereby allowing the support column and the limiting cylinder to disengage and unlock, facilitating disassembly and unlocking. The structural fit allows the limiting cylinder to slide under the limiting action of the inner slot of the bracket and be displaced by the push of the support column, which facilitates structural stability. Attached Figure Description

[0017] Figure 1 This is a front-view stereoscopic structural diagram of the present invention.

[0018] Figure 2 This is a rear-view stereoscopic view of the structure of the present invention.

[0019] Figure 3 This is a schematic diagram of the three-dimensional appearance of the present invention, with the concave collar hidden from view.

[0020] Figure 4 This is a schematic diagram of the three-dimensional appearance structure of the rigid tool holder of the present invention.

[0021] Figure 5 This is a schematic diagram of the front cross-sectional structure of the present invention.

[0022] Figure 6 This is a top-view cross-sectional structural diagram of the present invention.

[0023] Figure 7 For the present invention Figure 3 Enlarged structural diagram at point A in the middle.

[0024] Figure 8 For the present invention Figure 5 Enlarged structural diagram at point B.

[0025] Figure 9 For the present invention Figure 6 Enlarged structural diagram at point C.

[0026] In the diagram: 1. Bracket; 2. Mounting bracket; 3. Mounting strip; 4. Mounting plate; 5. Limiting post; 501. Angle limiting disc; 502. Limiting mounting hole; 503. Limiting ring one; 504. Limiting ring two; 6. Hydraulic synchronous telescopic rod; 7. Movable clamp mechanism; 701. Semi-ring clamp one; 702. Semi-ring clamp two; 703. Concave collar; 704. Mounting seat; 705. Main ball bearing; 706. Side ball bearing; 8. Rigid tool holder; 9. 10. Flexible pad; 11. Doctor blade body; 12. Limiting strip; 13. Strain gauge one; 14. Limiting cylinder; 15. Limiting hole; 16. Strain gauge two; 17. Permanent magnet ring; 18. Support cylinder; 19. High-precision telescopic rod; 20. Electromagnet one; 21. Auxiliary spring; 22. Permanent magnet one; 23. Piston one; 24. Support column; 25. Mounting groove; 26. Permanent magnet two; 27. Pin; 28. Electromagnet two; 29. ​​Return spring. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figures 1-9This invention provides a technical solution: a constant pressure and constant speed squeegee mechanism for heat transfer printing, comprising a bracket 1 and a rigid blade holder 8. A mounting frame 2 is movably mounted on the inner side of one end of the bracket 1. Two mounting strips 3 are fixedly mounted on the back of the mounting frame 2. Mounting plates 4 are fixedly mounted on both ends of the mounting frame 2. Limiting posts 5 are threadedly connected to both ends of the bracket 1. A hydraulic synchronous telescopic rod 6 is movably sleeved on the outer side of the limiting post 5 via a support ring. A movable clamp mechanism 7 is fixedly mounted on the output end of the hydraulic synchronous telescopic rod 6. An angle limiting plate 501 is fixedly mounted on the opposite end of the limiting post 5 via bolts. The angle limiting plate 501 has several limiting mounting holes 502 inside. Several... The support cylinder 17 has a high-precision telescopic rod 18 fixedly installed on its inner side. An electromagnet 19 is fixedly installed at the output end of the high-precision telescopic rod 18. An auxiliary spring 20 is sleeved on the outer side of the high-precision telescopic rod 18. A piston 22 is movably sleeved on the inner side of the support cylinder 17. A permanent magnet 21 is fixedly installed on one side of the piston 22. A support column 23 is fixedly installed on one side of the piston 22. An installation groove 24 is opened inside one end of the support column 23. An electromagnet 27 is fixedly installed in the middle of the installation groove 24. A return spring 28 is sleeved on the outer side of both ends of the electromagnet 27. A permanent magnet 25 is fixedly installed on the opposite end of the return spring 28. A pin 26 is fixedly installed on the opposite side of the permanent magnet 25.

[0029] The movable clamp mechanism 7 includes a semi-ring clamp 1 701 and a semi-ring clamp 2 702. The inner sides of both the semi-ring clamp 1 701 and the semi-ring clamp 2 702 are fixedly installed with mounting seats 704. Several side balls 706 are rolled on both sides of the mounting seat 704. Several main balls 705 are rolled on the inner side of the opposite side of the mounting seat 704. Two concave collars 703 are movably sleeved on the outer side of the mounting seat 704.

[0030] A number of limiting cylinders 13 are fixedly installed on one side of the rigid tool holder 8. Limiting holes 14 are opened at the top and bottom of the limiting cylinders 13. A flexible pad 9 is movably installed on the inner side of the rigid tool holder 8. A doctor blade body 10 is fixedly installed inside the flexible pad 9. A number of strain gauges 12 are attached to the bottom of the doctor blade body 10. A number of strain gauges 25 are fixedly installed inside the flexible pad 9.

[0031] The working principle of the above technical solution is as follows: In use, the rigid tool holder 8 is first inserted into one side of the bracket 1, causing the support column 23 and the support cylinder 17 to align with the limiting cylinder 13. At this time, the pin 26 is compressed, compressing the return spring 28, which slides inside the limiting cylinder 13 and returns to its original position inside the limiting hole 14, thereby locking the rigid tool holder 8 on one side of the bracket 1 and the mounting bracket 2. Then, according to the needs and installation requirements, the mounting bracket 2 and the bracket 1 are fixed to the slider and the sliding limiting mechanism using the mounting strip 3, the mounting plate 4, or the angle limiting disc 501. The installation position is fixed by connecting and fixing the slider or sliding limit mechanism through the limit mounting hole 502. Then, the movable hoop mechanism 7 is sleeved on the outer side of both ends of the ink roller, and the hydraulic synchronous telescopic rod 6 is connected to the hydraulic output device, so that the hydraulic synchronous telescopic rod 6 extends and retracts, thereby adjusting the position of the bracket 1 and the mounting bracket 2 relative to the ink roller, and making the doctor blade 10 standby in the doctor position. When fine adjustment is required, the extension and retraction of the high-precision telescopic rod 18 and the electromagnetic strength of the electromagnet 19 are synchronously and precisely controlled by the control system, so that the auxiliary spring 20 and the electromagnet 19 generate an electromagnetic adjustment effect, thereby pushing the piston 22 and the support column 23 to change position, thereby pushing the limit cylinder 13 and the rigid blade holder 8 out, thereby causing the gap between the flexible pad 9 and the doctor blade 10 relative to the ink roller and the contact position of the doctor blade 10 to change, so as to achieve the purpose of fine adjustment. The adjustment accuracy is high and the response is fast. When the doctor blade 10 has a wear quality problem, the strain gauge 12 and strain gauge 25 are relative to the bending of the doctor blade 10. When the strain signal changes, the deformation of the flexible pad 9 under pressure changes, which in turn causes strain gauge 12 and strain gauge 25 to reflect the strain signal. When the control system receives the signal, it precisely controls the electromagnet 19 and the high-precision telescopic rod 18 to adjust the position of the rigid blade holder 8 and the doctor blade body 10. This achieves high precision and fast response, reducing horizontal lines, ink streaks, and blade filaments during doctoring. In case of damage, the machine stops quickly based on the strain gauge signal, reducing printing losses. The machine can then resume operation after replacing the rigid blade holder 8 and the doctor blade body 10.

[0032] In another implementation scheme, such as Figures 1-9 As shown, the tops of the bracket 1 and the mounting bracket 2 are fixedly connected by bolts. Limiting strips 11 are fixedly installed on the top and bottom of the bracket 1. The mounting plate 4 is fixedly installed on both ends of the mounting bracket 2 by bolts. Several mounting holes are opened inside the mounting strip 3 and the mounting plate 4. A groove adapted to the mounting bracket 2 is opened on one side of the bracket 1.

[0033] The bracket 1 and mounting frame 2 are fixed by bolts, and the mounting positions are set by the mounting strip 3 and mounting plate 4, which facilitates installation at the printing installation position and can be fixed in the required position. It can also be installed at the position of the sliding limit mechanism. Installation and fixation can be carried out according to the requirements. Side and end mounting positions are provided to increase the adaptability of installation. The bracket 1 and mounting frame 2 are separate and can be disassembled, which facilitates disassembly, replacement and maintenance, and increases adaptability. In actual application, the mounting plate 4 can be replaced with different mounting structural components by removing the bolts according to the structural requirements of the printing press, so as to increase the adaptability of the equipment.

[0034] In another implementation scheme, such as Figures 1-9 As shown, one side of the second semi-ring 702 is fixedly connected to the output end of the hydraulic synchronous telescopic rod 6. The bottom ends of the first semi-ring 701 and the second semi-ring 702 are connected by a hinge seat. The top ends of the first semi-ring 701 and the second semi-ring 702 are fixedly connected by bolts. The main ball 705 and the side ball 706 are both rolled inside the mounting base 704 through ball grooves. The main ball 705 and the side ball 706 are evenly distributed in a circular pattern on the outer wall of the mounting base 704. The inner sides of the two concave collars 703 are in rolling contact with the main ball 705 and the side ball 706.

[0035] When the movable clamp mechanism 7 is fitted onto the outside of the ink roller, the top bolts of the semi-circular clamp 701 and the semi-circular clamp 702 are removed, and the concave collar 703 is fitted onto the shaft of the ink roller. At this time, the semi-circular clamp 701 and the semi-circular clamp 702 are merged and the bolts are installed and fixed. The concave collar 703 is supported by the rolling of the main ball bearing 705 and the side ball bearing 706. The concave collar 703 is in contact with the shaft of the ink roller, thereby providing rotational support and maintaining a stable position. This allows the hydraulic synchronous telescopic rod 6 and the movable clamp mechanism 7 to be coaxial with the shaft of the ink roller, facilitating subsequent installation and ensuring high-precision parallelism. The adjustment accuracy and speed of the doctor blade and the ink roller are ensured by adjusting the extension and retraction of the hydraulic synchronous telescopic rod 6 in combination with electromagnetic adjustment.

[0036] In another implementation scheme, such as Figures 1-9 As shown, the limiting mounting holes 502 are evenly distributed in a circle inside the angle limiting plate 501. The outer side of the limiting post 5 is movably sleeved with a limiting ring 1 503, and the outer side of the limiting post 5 is movably sleeved with a limiting ring 2 504. The limiting ring 1 503 is located on the opposite side of the angle limiting plate 501 and the hydraulic synchronous telescopic rod 6, and the limiting ring 2 504 is located on the opposite side of the bracket 1 and the hydraulic synchronous telescopic rod 6.

[0037] The limiting mounting hole 502 provides an installation position, facilitating the installation of the angle limiting plate 501 on the axial linear guide rail. When driving is required, the drive mechanism achieves constant-speed movement, and the pressure regulating component maintains constant pressure against the printing roller, ensuring stable ink scraping pressure and speed. When driving is not required, it remains connected and fixed to the slider or sliding limiting mechanism, ensuring the temperature of the installation position and angle, and facilitating the connection with the sliding mechanism. The fitting positions of the first limiting ring 503 and the second limiting ring 504 limit the collar of the hydraulic synchronous telescopic rod 6. The positioning system ensures that the installation positions of the hydraulic synchronous telescopic rod 6 and the movable clamp mechanism 7 are limited relative to the rotation shaft position of the ink roller, facilitating installation and use. Furthermore, the limiting post 5, angle limiting disc 501, limiting ring one 503, and limiting ring two 504 can be replaced as needed. When dealing with a longer ink roller rotation shaft, the washer sizes of limiting ring one 503 and limiting ring two 504 can be changed to match the installation position for limiting, facilitating installation with brackets 1 and mounting brackets 2 of different sizes and models, indirectly maintaining relative stability, and facilitating installation auxiliary operations.

[0038] In another implementation scheme, such as Figures 1-9 As shown, one end of the auxiliary spring 20 is fixedly installed inside the support cylinder 17, and the other end of the auxiliary spring 20 is fixedly installed on one side of the permanent magnet 21. The opposite ends of the electromagnet 19 and the permanent magnet 21 are distributed with the same poles repelling each other. The support column 23 is movably sleeved inside the support cylinder 17. A permanent magnet ring 16 is fixedly sleeved on the outside of the support cylinder 17. The permanent magnet ring 16 and the support cylinder 17 are linearly and evenly distributed on one side of the mounting frame 2.

[0039] When fine adjustment is required, the extension and retraction of the high-precision telescopic rod 18 and the electromagnetic strength of the electromagnet 19 are synchronously and precisely controlled, thereby generating an electromagnetic adjustment effect between the auxiliary spring 20 and the electromagnet 19. This pushes the piston 22 and the support column 23 to change their positions, thereby pushing out the limiting cylinder 13 and the rigid blade holder 8. This causes the gap between the flexible pad 9 and the doctor blade body 10 relative to the ink roller to change, and the contact position of the doctor blade body 10 to change, achieving the purpose of fine adjustment. The adjustment accuracy is high and the response is rapid.

[0040] In another implementation scheme, such as Figures 1-9 As shown, the dimensions of the support cylinder 17 are compatible with the dimensions of the limiting cylinder 13. The inside of the bracket 1 is provided with slots that are compatible with the permanent magnet ring 16 and the support cylinder 17. The inside of one side of the bracket 1 is provided with slots that are compatible with the limiting cylinder 13. The dimensions of the support cylinder 17 and the support column 23 are compatible with the dimensions of the limiting cylinder 13. The limiting cylinder 13 is linearly and evenly distributed on one side of the rigid tool holder 8.

[0041] The support cylinder 17 slides inside the limiting cylinder 13, while the limiting cylinder 13 is limited in the slot inside the bracket 1 to ensure the position. The support cylinder 17 and the permanent magnet ring 16 are limited on the inside of the bracket 1 to ensure accurate positioning. The support cylinder 17 and the support column 23 are sleeved inside the limiting cylinder 13 to maintain stable position. The slot provided inside the bracket 1 by the limiting cylinder 13 facilitates structural stability. The bracket 1, the mounting bracket 2 and the rigid tool holder 8 can be installed by plugging them in. The assembly and disassembly are quick and easy, and the limiting and coordination of each structure is convenient for combination.

[0042] In another implementation scheme, such as Figures 1-9 As shown, the opposite end of the return spring 28 is fixedly installed on the outer side of the middle part of the electromagnet 27 by the support frame. The permanent magnet 25 and the electromagnet 27 are distributed at opposite ends. The specifications and dimensions of the pin 26 are adapted to the specifications and dimensions of the limiting hole 14. The pin 26 moves through the mounting groove 24 and extends to the outer side of the support column 23. One end of the support column 23 abuts against the outer side of the rigid tool holder 8.

[0043] After the return spring 28 is fixed, the elastic return force is applied to the permanent magnet 25 and the pin 26, causing the pin 26 to return to its original position. When the support cylinder 17 and the support column 23 are inserted into the limiting cylinder 13, the pin 26 is limited and compressed inside the limiting cylinder 13. When it moves to the position of the limiting hole 14, the return spring 28 causes the permanent magnet 25 and the pin 26 to return to their original position and be pushed up, and then inserted into the inner side of the limiting hole 14 for easy locking connection. When disassembly or assembly is required, the electromagnet 27 is activated to generate magnetic force, and the two ends generate magnetic pole attraction force on the permanent magnet 25, causing the permanent magnet 25 and the pin 26 to retract, and then causing the pin 26 to slide away from the position of the limiting hole 14, thereby allowing the support column 23 and the limiting cylinder 13 to disengage and unlock, making disassembly and unlocking convenient and easy to use. The support column 23 contacts the limiting cylinder 13 and the rigid tool holder 8 on one side, which facilitates positional stability. Under the sliding limiting action of the inner slot of the bracket 1, the limiting cylinder 13 is displaced by the push of the support column 23, which facilitates structural stability.

[0044] In another implementation scheme, such as Figures 1-9 As shown, strain gauge 12 is linearly and uniformly distributed at the bottom of the doctor blade body 10, and strain gauge 25 is linearly and uniformly attached to the top and bottom of the doctor blade body 10. The positions of strain gauge 12 and strain gauge 25 correspond to the positions of the limiting cylinder 13. The flexible pad 9 is made of one of the following materials: modified polyester-type cast polyurethane, polyester-type cast polyurethane, thermoplastic polyurethane, or high-elasticity nitrile rubber.

[0045] When the doctor blade body 10 experiences wear and tear, the strain signals of strain gauge 12 and strain gauge 25 relative to the doctor blade body 10 change, and the deformation of the flexible pad 9 under pressure changes. As a result, both strain gauge 12 and strain gauge 2 15 can reflect the strain signal. When the control system receives the signal, it precisely controls the electromagnet 19 and the high-precision telescopic rod 18 to adjust the position of the rigid blade holder 8 and the doctor blade body 10. This achieves high precision and fast response, reducing horizontal lines, ink streaks, and blade filaments during doctoring. The flexible pad 9 compensates for the flatness error of the blade, ensures uniform pressure distribution across the entire width, buffers vibration, avoids blade filaments and ink streaks, transmits pressure, and provides elastic deformation to achieve adaptive contact between the blade and the roller surface. As a strain gauge carrier, it converts the force on the blade into a detectable deformation signal. The material is a modified polyester-type cast polyurethane with a Shore A hardness of 60-80, balancing elasticity and rigidity, ensuring uniform deformation and good signal linearity. Key advantages include: moderate elastic modulus (0.5-2 GPa): uniform deformation under stress, allowing the strain gauge to detect stable resistance changes and provide a clear signal; ink / solvent resistance: fully compatible with heat transfer printing pastes and solvent-based inks, exhibiting no swelling and dimensional stability over long-term use; excellent adhesion: moderate surface polarity allows for strong adhesion of the strain gauge adhesive, preventing detachment; good insulation: PU is an excellent electrical insulator, preventing strain gauge leakage and ensuring a pure signal; strong fatigue resistance: no permanent deformation under repeated stress, doctor blade movement, or pressure fluctuations, ensuring stable long-term measurement accuracy; and customization: optimized formula allows for temperature resistance up to 100℃ and creep resistance, adapting to different working conditions. Note: For high-temperature environments, a high-temperature resistant polyester CPU should be selected to avoid signal drift caused by creep. The flexible pad 9 is made of polyester-type cast polyurethane of Shore A60-80 with an elastic modulus of 0.5-2 GPa. It has ink resistance and fatigue resistance for the doctor blade, and can produce uniform and measurable deformation when the blade is under force. A resistance strain gauge is bonded to the surface of the flexible pad 9. The strain gauge is integrated with the flexible clip through encapsulation adhesive. It can convert deformation into an electrical signal and feed it back to the control unit to adjust the position of the blade holder and realize constant pressure and constant speed auxiliary control. The flexible pad 9 forms a flexible clip to fit and install the doctor blade body 10.

[0046] In another implementation scheme, such as Figures 1-9 As shown, the flexible pad 9 is fixedly installed on the inner side of the rigid blade holder 8 by bolts. One side of the bracket 1 is provided with a slot that matches the rigid blade holder 8. The flexible pad 9 and the doctor blade body 10 are located in the middle of the bracket 1 and the rigid blade holder 8.

[0047] The rigid blade holder 8 and the flexible pad 9 are connected by bolts to facilitate the installation and replacement of new flexible pads 9 and doctor blade bodies 10. It is also convenient to install the flexible pads 9 and doctor blade bodies 10 inside the rigid blade holder 8 and to assemble the rigid blade holder 8 inside the bracket 1. This facilitates disassembly and replacement, and indirectly improves the efficiency of use.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A constant pressure and constant speed doctor blade mechanism for heat transfer printing, comprising a support (1) and a rigid blade holder (8), characterized in that: A mounting bracket (2) is movably installed on the inner side of one end of the bracket (1). Two mounting strips (3) are fixedly installed on the back of the mounting bracket (2). Mounting plates (4) are fixedly installed on both ends of the mounting bracket (2). Limiting posts (5) are threadedly connected to both ends of the bracket (1). A hydraulic synchronous telescopic rod (6) is movably sleeved on the outer side of the limiting post (5) through a support ring. A movable hoop mechanism (7) is fixedly installed on the output end of the hydraulic synchronous telescopic rod (6). An angle limiting plate (501) is fixedly installed on the opposite end of the limiting post (5) through bolts. Several limiting mounting holes (502) are opened inside the angle limiting plate (501). Several support cylinders (17) are fixedly installed on one side of the mounting bracket (2). A high-precision telescopic rod is fixedly installed on the inner side of the support cylinder (17). 18), an electromagnet is fixedly installed at the output end of the high-precision telescopic rod (18), an auxiliary spring (20) is sleeved on the outside of the high-precision telescopic rod (18), a piston (22) is movably sleeved on the inside of the support cylinder (17), a permanent magnet (21) is fixedly installed on one side of the piston (22), a support column (23) is fixedly installed on one side of the piston (22), an installation groove (24) is opened inside one end of the support column (23), an electromagnet (27) is fixedly installed in the middle of the installation groove (24), a return spring (28) is sleeved on the outside of both ends of the electromagnet (27), a permanent magnet (25) is fixedly installed on the opposite end of the return spring (28), and a pin (26) is fixedly installed on the opposite side of the permanent magnet (25). The movable clamp mechanism (7) includes a semi-ring clamp one (701) and a semi-ring clamp two (702). The inner sides of the semi-ring clamp one (701) and the semi-ring clamp two (702) are fixedly installed with mounting seats (704). Several side balls (706) are rolled on both sides of the mounting seat (704). Several main balls (705) are rolled on the inner side of the opposite side of the mounting seat (704). Two concave collars (703) are movably sleeved on the outer side of the mounting seat (704). A number of limiting cylinders (13) are fixedly installed on one side of the rigid tool holder (8). Limiting holes (14) are opened at the top and bottom of the limiting cylinders (13). A flexible pad (9) is movably installed on the inner side of the rigid tool holder (8). A doctor blade body (10) is fixedly installed inside the flexible pad (9). A number of strain gauges (12) are attached to the bottom of the doctor blade body (10). A number of strain gauges (15) are fixedly installed inside the flexible pad (9).

2. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 1, characterized in that: The top of the bracket (1) and the mounting bracket (2) are fixedly connected by bolts. Limiting strips (11) are fixedly installed on the top and bottom of the bracket (1). The mounting plate (4) is fixedly installed on both ends of the mounting bracket (2) by bolts. Several mounting holes are opened inside the mounting strip (3) and the mounting plate (4). A slot adapted to the mounting bracket (2) is opened on one side of the bracket (1).

3. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 1, characterized in that: One side of the second semi-ring (702) is fixedly connected to the output end of the hydraulic synchronous telescopic rod (6). The bottom ends of the first semi-ring (701) and the second semi-ring (702) are connected by a hinge seat. The top ends of the first semi-ring (701) and the second semi-ring (702) are fixedly connected by bolts. The main ball (705) and the side ball (706) are both rolled inside the mounting base (704) through ball grooves. The main ball (705) and the side ball (706) are evenly distributed in a circular pattern on the outer wall of the mounting base (704). The inner sides of the two concave collars (703) are in rolling contact with the main ball (705) and the side ball (706).

4. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 1, characterized in that: The limiting mounting holes (502) are evenly distributed in a circle inside the angle limiting plate (501). The outer side of the limiting post (5) is movably sleeved with a limiting ring one (503) and the outer side of the limiting post (5) is movably sleeved with a limiting ring two (504). The limiting ring one (503) is located on the opposite side of the angle limiting plate (501) and the hydraulic synchronous telescopic rod (6), and the limiting ring two (504) is located on the opposite side of the bracket (1) and the hydraulic synchronous telescopic rod (6).

5. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 1, characterized in that: One end of the auxiliary spring (20) is fixedly installed inside the support cylinder (17), and the other end of the auxiliary spring (20) is fixedly installed on one side of the permanent magnet (21). The electromagnet (19) and the permanent magnet (21) are distributed with the same poles repelling each other. The support column (23) is movably sleeved inside the support cylinder (17). A permanent magnet ring (16) is fixedly sleeved on the outside of the support cylinder (17). The permanent magnet ring (16) and the support cylinder (17) are linearly and evenly distributed on one side of the mounting frame (2).

6. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 5, characterized in that: The dimensions of the support cylinder (17) are compatible with those of the limiting cylinder (13). The bracket (1) has slots inside that are compatible with the permanent magnet ring (16) and the support cylinder (17). The bracket (1) has slots inside one side that are compatible with the limiting cylinder (13). The dimensions of the support cylinder (17) and the support column (23) are compatible with those of the limiting cylinder (13). The limiting cylinder (13) is linearly and evenly distributed on one side of the rigid tool holder (8).

7. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 1, characterized in that: The opposite end of the reset spring (28) is fixedly installed on the outer side of the middle part of the electromagnet (27) by the support frame. The permanent magnet (25) and the electromagnet (27) are distributed at opposite ends. The pin (26) is adapted to the size of the limiting hole (14). The pin (26) moves through the mounting groove (24) and extends to the outside of the support column (23). One end of the support column (23) abuts against the outside of the rigid tool holder (8).

8. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 1, characterized in that: The strain gauge one (12) is linearly and uniformly distributed at the bottom of the doctor blade body (10), and the strain gauge two (15) is linearly and uniformly attached to the top and bottom of the doctor blade body (10). The positions of the strain gauge one (12) and the strain gauge two (15) correspond to the position of the limiting cylinder (13). The flexible pad (9) is made of one of the following materials: modified polyester casting polyurethane, polyester casting polyurethane, thermoplastic polyurethane, and high elastic nitrile rubber.

9. The constant pressure and constant speed doctor blade mechanism for heat transfer printing according to claim 1, characterized in that: The flexible pad (9) is fixedly installed on the inner side of the rigid blade holder (8) by bolts. The bracket (1) has a slot on one side that is compatible with the rigid blade holder (8). The flexible pad (9) and the doctor blade body (10) are located in the middle of the bracket (1) and the rigid blade holder (8).

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