A printing device

Abstract

The present application provides a printing device, which relates to the technical field of circuit board printing, including a main oil storage chamber for storing excess ink in the printing head, a liquid inlet pipe connected to the main oil storage chamber, a main fixed plate fixedly connected to the liquid inlet pipe, a main scraper plate slidably connected to the main fixed plate, a negative pressure chamber is provided on the side of the main scraper plate away from the blade back, the negative pressure chamber is connected to the liquid inlet pipe, and the negative pressure chamber is used to recover a certain height of ink to the main oil storage chamber. The present application can reduce the problem of too thick ink when applying ink to the circuit board, and can absorb excess ink, so that the ink on the screen is within a certain controllable range.

Description

Technical Field

[0001] The present application relates to the technical field of circuit board printing, and in particular to a printing device. Background Art

[0002] Circuit board printing equipment usually refers to a circuit board screen printer, which is a device specially used for printing patterns, text, marks, etc. on printed circuit boards. It usually includes a fixed platform and a moving screen printing head. The ink is transferred from the screen to the circuit board surface through the scraper on the screen printing head. During the return stroke of the scraper, the scraper spreads the ink and moves the ink to the initial side. These devices are widely used in electronic components, home appliances, toys and other industries, especially playing an important role in the circuit board manufacturing process.

[0003] Referring to the Chinese patent document with publication number CN113733721A, entitled A flexible circuit printing method and a flexible circuit printing device, the device drives side scraper 1 and side scraper 2 to move to the printing frame body through a motor, and then drives the reciprocating screw mechanism through the motor to drive side scraper 1 and side scraper 2 to scrape the material, so that the printed material is located in the middle position of the two side scrapers, thereby making full use of the printed material.

[0004] According to the above technical solution, when printing ink on a circuit board, it is necessary to first pour the ink onto the upper surface of the screen, and use a scraper on the printing equipment to scrape the ink and spread the ink on the upper surface of the screen. When the ink is poured onto the upper surface of the screen, the circuit board is attached to the lower surface of the screen. In the process of scraping the ink, the ink is pressed into the holes on the screen and transferred to the surface of the circuit board, and a desired pattern is formed on the surface of the circuit board. After scraping the ink, it is necessary to lift the scraper and scrape the ink to the initial position to print the next circuit board of the same batch. In this process, unrecovered ink will gradually accumulate on the screen, and the accumulation process will result in excessive ink, affecting the printing quality. Summary of the invention

[0005] In view of this, the present application provides a printing device, aiming to solve the problem of too thick ink on the silk screen.

[0006] A printing device provided in the present application adopts the following technical scheme, comprising a printing machine, a printing head fixedly connected to the printing machine, a screen fixedly connected under the printing head, and a movable mechanism for moving a circuit board; a main oil storage chamber for storing excess ink is provided in the printing head, a liquid inlet pipe is connected to the main oil storage chamber, a main fixed plate is fixedly connected to the liquid inlet pipe, a main scraper plate is slidably connected to the main fixed plate, a negative pressure chamber is provided on the side of the main scraper plate away from the blade back, the negative pressure chamber is connected to the liquid inlet pipe, and the negative pressure chamber is used to recover ink of a certain height into the main oil storage chamber.

[0007] By collecting excess ink on the screen, ink waste can be reduced. The recycled ink can be mixed with new ink to reduce the inconsistency of color and performance of the same batch of ink due to long-term exposure of the ink. At the same time, recycling excess ink can prevent ink from accumulating on the screen, thereby keeping the screen clean and the printed pattern clear.

[0008] Optionally, a blocking mechanism for blocking ink from flowing out is provided at the connection between the liquid inlet pipe and the negative pressure chamber.

[0009] Optionally, the blocking mechanism includes an adjusting motor slidably connected to the side wall of the main fixed plate, a blocking baffle is slidably connected to the main fixed plate, the blocking baffle is used to seal the connection between the liquid inlet pipe and the negative pressure chamber, a reset spring is provided at the connection between the blocking baffle and the main fixed plate for pushing the blocking baffle to reset, and an adjusting baffle is fixedly connected to the side wall of the blocking baffle for pushing the adjacent blocking baffle to move.

[0010] By blocking the connection between the liquid inlet pipe and the negative pressure chamber, the probability of ink directly flowing out of the negative pressure chamber is reduced.

[0011] Optionally, an auxiliary oil storage chamber for allowing excess ink to flow out again is provided on the printing head, a control baffle is slidably connected to the main oil storage chamber, a first adjusting cylinder is fixedly connected to the printing head, a first adjusting baffle is fixedly connected to the output shaft of the first adjusting cylinder, the first adjusting baffle is fixedly connected to the main fixed plate, the first adjusting baffle can drive the control baffle to slide in the vertical direction, a connecting port that can be connected to the auxiliary oil storage chamber is provided on the main oil storage chamber, and the control baffle can block the connection between the main oil storage chamber and the auxiliary oil storage chamber when moving downward.

[0012] By adjusting the scraper position, the height of the ink layer can be accurately controlled, which can ensure the electrical performance of the circuit to a certain extent. At the same time, by properly adjusting the distance between the scraper and the screen, the ink can be transferred to the circuit board more evenly, reducing printing defects. At the same time, different types of inks require different printing pressures and ink layer thicknesses. By adjusting the scraper position, it is possible to better adapt to the characteristics of different inks.

[0013] Optionally, a second adjusting cylinder is fixedly connected to the printing head, a second adjusting baffle is fixedly connected to the output shaft of the second adjusting cylinder, an auxiliary fixing plate is fixedly connected to the second adjusting baffle, the auxiliary fixing plate is fixedly connected to a liquid outlet pipe connected to an auxiliary oil storage chamber, an auxiliary scraper plate is fixedly connected to the auxiliary fixing plate, a blocking cylinder is fixedly connected to the auxiliary scraper plate, and a blocking block for blocking the liquid outlet pipe from discharging liquid is fixedly connected to the output shaft of the blocking cylinder.

[0014] Scraping back the ink can help the ink to be evenly distributed on the screen, ensuring that the ink thickness is consistent each time you print. During the printing process, the scraping action can remove excess ink remaining on the screen, and can fill the ink when there is insufficient ink in some areas, avoiding printing with too thin or too thick ink. At the same time, it can prevent the ink from drying out due to long-term exposure on the screen, and maintain the fluidity of the ink.

[0015] Optionally, the bottom surface of the main scraper plate is lower than the bottom surface of the negative pressure chamber.

[0016] Optionally, a locking bolt is fixedly connected to the main scraper plate, the locking bolt penetrates the main fixed plate, and a locking nut is rotatably connected to the locking bolt for driving the locking bolt to move.

[0017] The secondary adjustment can fine-tune the position of the main scraper plate to obtain a more precise printing pattern. At the same time, the secondary adjustment can further ensure the uniformity and consistency of the ink layer and reduce the occurrence of printing defects.

[0018] Optionally, the liquid outlet pipe and the liquid inlet pipe are both made of flexible materials and can adapt to the movement of the main scraper plate and the auxiliary scraper plate.

[0019] In summary, compared with the prior art, the present application includes at least one of the following beneficial technical effects:

[0020] 1. By collecting the excess ink on the screen, the waste of ink can be reduced. At the same time, the recycled ink can be mixed with new ink to reduce the inconsistency of the color and performance of the same batch of ink due to long-term exposure of the ink. At the same time, the recycling of excess ink can prevent the accumulation of ink on the screen, thereby keeping the screen clean and the clarity of the printed pattern.

[0021] 2. By adjusting the position of the scraper, the height of the ink layer can be accurately controlled, which can ensure the electrical performance of the circuit to a certain extent. At the same time, by properly adjusting the distance between the scraper and the screen, the ink can be transferred to the circuit board more evenly, reducing printing defects. At the same time, different types of inks require different printing pressures and ink layer thicknesses. By adjusting the scraper position, it can better adapt to the characteristics of different inks.

[0022] 3. The position of the main scraper can be fine-tuned through secondary adjustment to obtain a more accurate printing pattern. At the same time, the uniformity and consistency of the ink layer can be further ensured through secondary adjustment to reduce the occurrence of printing defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of a printing device according to this embodiment;

[0024] Figure 2 This is a schematic structural diagram of the first regulating cylinder and the first regulating baffle in this embodiment;

[0025] Figure 3 This is a schematic diagram of the structure of the second regulating cylinder and the second regulating baffle in this embodiment;

[0026] Figure 4 This is a schematic diagram of the structure of the main fixed plate and the main scraper plate of this embodiment;

[0027] Figure 5 Schematic diagram of the structure of the main oil storage chamber and the auxiliary oil storage chamber of this embodiment;

[0028] Figure 6 For this embodiment Figure 4 A partial enlarged view of the middle area A;

[0029] Figure 7 Schematic diagram of the structure of the blocking baffle in this embodiment.

[0030] Explanation of the reference numerals in the accompanying drawings: 1. Printing machine; 11. Printing head; 12. Silk screen; 2. Main oil storage chamber; 21. Liquid inlet pipe; 22. Main fixing plate; 23. Main scraper plate; 24. Negative pressure chamber; 3. Blocking mechanism; 31. Adjusting motor; 32. Blocking baffle; 33. Reset spring; 34. Adjusting block; 4. Auxiliary oil storage chamber; 41. Control baffle; 42. First adjusting cylinder; 43. First adjusting baffle; 44. Connecting port; 5. Second adjusting cylinder; 51. Second adjusting baffle; 52. Auxiliary fixing plate; 53. Liquid outlet pipe; 54. Auxiliary scraper plate; 55. Blocking cylinder; 56. Blocking block; 6. Locking bolt; 61. Locking nut. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the embodiments of the present application. Figure 1-Figure 7 , the technical scheme of the embodiment of the present application is clearly and completely described. Obviously, the described embodiment is a part of the embodiment of the present application, not all of the embodiments. Based on the described embodiment of the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of this application.

[0032] Reference Figure 1 and Figure 5 The present embodiment provides a printing device, comprising a printing machine 1 placed on a horizontal plane, a printing head 11 being slidably connected to the printing machine 1, a screen 12 being fixedly connected to the printing machine 1, and the screen 12 being arranged below the printing head 11, a moving mechanism for moving the circuit board being arranged below the screen 12, a main oil storage chamber 2 for storing excess ink being provided in the printing head 11, a liquid inlet pipe 21 being connected in the oil storage chamber, a main fixed plate 22 being fixedly connected to the liquid inlet pipe 21, a main scraper plate 23 being slidably connected to the main fixed plate 22, a negative pressure chamber 24 being provided on the side of the main scraper plate 23 away from the blade back, the negative pressure chamber 24 being connected to the liquid inlet pipe 21, and the bottom surface of the main scraper plate 23 being lower than the bottom surface of the negative pressure chamber 24, and the negative pressure chamber 24 being used to recover ink of a certain height into the main oil storage chamber 2.

[0033] In the present application, multiple negative pressure chambers 24 and liquid inlet pipes 21 are used as an example for explanation, and they can be increased or reduced according to actual needs during production.

[0034] The printing machine 1 is placed on a horizontal plane, and the circuit board to be painted is placed on the moving mechanism. The moving mechanism drives the circuit board to a position below the screen 12, ink is poured onto the screen 12, and the position of the printing head 11 is adjusted so that the main scraper plate 23 on the printing head 11 is located on one side of the ink. The printing head 11 drives the main scraper plate 23 to scrape the ink. During the scraping process, the external negative pressure pump is started, and the negative pressure pump is connected to the main oil storage chamber 2. When the ink is scraped flat, the ink above the negative pressure chamber 24 is sucked into the main oil storage chamber 2 by the negative pressure pump through the liquid inlet pipe 21 and stored in the main oil storage chamber 2.

[0035] By collecting excess ink on the screen 12, ink waste can be reduced, and the recycled ink can be mixed with new ink to reduce the inconsistency in color and performance of the same batch of ink due to long-term exposure of the ink. At the same time, recycling excess ink can prevent ink from accumulating on the screen 12, thereby keeping the screen 12 clean and the printed pattern clear.

[0036] Reference Figure 5 , Figure 6 and Figure 7A blocking mechanism 3 for blocking the outflow of ink is provided at the connection between the liquid inlet pipe 21 and the negative pressure chamber 24. The blocking mechanism 3 includes: an adjusting motor 31, a blocking baffle 32, a reset spring 33 and an adjusting block 34. The adjusting motor 31 is slidably connected to the main fixed plate 22. The main fixed plate 22 is slidably connected with a blocking baffle 32. The blocking baffle 32 is used to block the connection between the liquid inlet pipe 21 and the negative pressure chamber 24. A reset spring 33 for pushing the blocking baffle 32 to reset is provided at the connection between the blocking baffle 32 and the main fixed plate 22. An adjusting block 34 for pushing the adjacent blocking baffle 32 to move is fixedly connected to the side wall of the blocking baffle 32.

[0037] The adjusting motor 31 can be set as a stepping motor, etc. After the main scraper plate 23 completes a stroke of scraping the ink, the adjusting motor 31 moves and pushes the blocking baffle 32 to move closer to the connection between the liquid inlet pipe 21 and the negative pressure chamber 24, so that the blocking baffle 32 blocks the connection between the liquid inlet pipe 21 and the negative pressure chamber 24. After blocking, the blocking baffle 32 at the initial position of the adjusting motor 31 moves under the push of the adjusting motor 31, and at the same time, the blocking baffle 32 at the initial position is driven by the adjusting block 34 set on the side wall to block the connection between the liquid inlet pipe 21 and the negative pressure chamber 24.

[0038] By blocking the connection between the liquid inlet pipe 21 and the negative pressure chamber 24 , the probability of ink directly flowing out of the negative pressure chamber 24 is reduced.

[0039] Reference Figure 2 , Figure 4 and Figure 5 The printing head 11 is provided with an auxiliary oil storage chamber 4 for allowing excess ink to flow out again, a control baffle 41 is slidably connected to the main oil storage chamber 2, a first adjusting cylinder 42 is fixedly connected to the printing head 11, a first adjusting baffle 43 is fixedly connected to the output shaft of the first adjusting cylinder 42, the first adjusting baffle 43 is fixedly connected to the main fixed plate 22, the first adjusting baffle 43 can drive the control baffle 41 to slide in the vertical direction, a connecting port 44 that can be connected with the auxiliary oil storage chamber 4 is provided on the main oil storage chamber 2, and the control baffle 41 can block the connection between the main oil storage chamber 2 and the auxiliary oil storage chamber 4 when it moves downward.

[0040] When it is necessary to adjust the position of the main scraper plate 23, the first adjusting cylinder 42 is started, so that the first adjusting cylinder 42 drives the first adjusting baffle 43 to move, and the first adjusting baffle 43 drives the main fixed plate 22 to move downward. When the main fixed plate 22 moves downward, the main scraper plate 23 located on the main fixed plate 22 moves downward. During the downward movement, the distance between the main scraper plate 23 and the screen 12 is adjusted to achieve printing of inks of different thicknesses. After scraping, the first adjusting cylinder 42 is recycled, and the first adjusting baffle 43 is driven to move upward during recycling. When the first adjusting baffle 43 moves upward, the baffle 41 is controlled to move in the vertical direction, and the baffle 41 is controlled to open the connection between the main oil storage chamber 2 and the auxiliary oil storage chamber 4, so that the ink in the main oil storage chamber 2 enters the auxiliary oil storage chamber 4 from the connecting port 44.

[0041] By adjusting the scraper position, the height of the ink layer can be accurately controlled, which can ensure the electrical performance of the circuit to a certain extent. At the same time, by properly adjusting the distance between the scraper and the screen 12, the ink can be transferred to the circuit board more evenly, reducing printing defects. At the same time, different types of inks require different printing pressures and ink layer thicknesses. By adjusting the scraper position, it is possible to better adapt to the characteristics of different inks.

[0042] Reference Figure 3 , Figure 4 and Figure 5 A second regulating cylinder 5 is fixedly connected to the printing head 11, a second regulating baffle 51 is fixedly connected to the output shaft of the second regulating cylinder 5, an auxiliary fixing plate 52 is fixedly connected to the second regulating baffle 51, the auxiliary fixing plate 52 is fixedly connected to a liquid outlet pipe 53 connected to the auxiliary oil storage chamber 4, an auxiliary scraper plate 54 is fixedly connected to the auxiliary fixing plate 52, a blocking cylinder 55 is fixedly connected to the auxiliary scraper plate 54, and a blocking block 56 for blocking the liquid outlet pipe 53 from discharging liquid is fixedly connected to the output shaft of the blocking cylinder 55.

[0043] After the ink is scraped flat, start the second regulating cylinder 5, so that the second regulating cylinder 5 drives the second regulating baffle 51 to move downward, and the second regulating baffle 51 drives the auxiliary fixing plate 52 to move downward, and when the auxiliary fixing plate 52 moves downward, it drives the auxiliary scraper plate 54 to move downward, and adjusts the distance between the auxiliary scraper plate 54 and the screen 12, and starts the blocking cylinder 55, so that the blocking cylinder 55 drives the blocking block 56 to move, so that the liquid in the auxiliary oil storage chamber 4 flows out from the liquid outlet pipe 53, so that the ink is scraped and filled onto the screen 12 for the second time.

[0044] Scraping the ink back can help the ink to be evenly distributed on the screen 12, ensuring that the ink thickness is consistent each time it is printed. During the printing process, the scraping action can remove excess ink remaining on the screen 12, and can fill the ink when there is insufficient ink in some areas, avoiding the ink being too thin or too thick during printing. At the same time, it can prevent the ink from drying out due to long-term exposure on the screen 12, thereby maintaining the fluidity of the ink.

[0045] Reference Figure 5 A locking bolt 6 is fixedly connected to the main scraper plate 23, and the locking bolt 6 penetrates the main fixed plate 22. A locking nut 61 is rotatably connected to the locking bolt 6 for driving the locking bolt 6 to move.

[0046] The locking nut 61 is rotated so that the locking nut 61 drives the locking bolt 6 to move, and the locking bolt 6 can drive the main scraper plate 23 to move a second time, so as to adjust the distance between the main scraper plate 23 and the screen 12 more accurately.

[0047] The position of the main scraper plate 23 can be fine-tuned through the secondary adjustment to obtain a more accurate printing pattern. At the same time, the uniformity and consistency of the ink layer can be further ensured through the secondary adjustment to reduce the occurrence of printing defects.

[0048] Reference Figure 4 The liquid outlet pipe 53 and the liquid inlet pipe 21 are both made of flexible materials and can adapt to the movement of the main scraper plate 23 and the auxiliary scraper plate 54.

[0049] The liquid outlet pipe 53 and the liquid inlet pipe 21 are configured with flexible materials so that the liquid inlet pipe 21 and the liquid outlet pipe 53 can better adapt to the movement of the main scraper plate 23 and the auxiliary scraper plate 54, thereby reducing the occurrence of rupture of the liquid inlet pipe 21 and the liquid outlet pipe 53 due to the movement of the main scraper plate 23 and the auxiliary scraper plate 54.

[0050] The implementation principle of a printing device in an embodiment of the present application is: a printing machine 1 is placed on a horizontal plane, and a circuit board to be painted is placed on a moving mechanism, the moving mechanism drives the circuit board to a position below the screen 12, ink is poured onto the screen 12 and the position of the print head 11 is adjusted.

[0051] Start the first adjusting cylinder 42, so that the first adjusting cylinder 42 drives the first adjusting baffle 43 to move, and the first adjusting baffle 43 drives the main fixed plate 22 to move downward, and when the main fixed plate 22 moves downward, the main scraper plate 23 located on the main fixed plate 22 moves downward, and during the downward movement, the distance between the main scraper plate 23 and the wire mesh 12 is adjusted, and the locking nut 61 is rotated so that the locking nut 61 drives the locking bolt 6 to move, so that the locking bolt 6 can drive the main scraper plate 23 to move a second time, and the distance between the main scraper plate 23 and the wire mesh 12 is adjusted more accurately.

[0052] The printing head 11 drives the main scraper plate 23 to scrape the ink. During the scraping process, the external negative pressure pump is started, and the negative pressure pump is connected to the main oil storage chamber 2. When the ink is scraped flat, the ink above the negative pressure chamber 24 is sucked into the main oil storage chamber 2 by the negative pressure pump through the liquid inlet pipe 21 and stored in the main oil storage chamber 2.

[0053] After the main scraper plate 23 finishes scraping the ink for one stroke, the adjusting motor 31 moves and pushes the blocking baffle 32 to move closer to the connection between the liquid inlet pipe 21 and the negative pressure chamber 24, so that the blocking baffle 32 blocks the connection between the liquid inlet pipe 21 and the negative pressure chamber 24. After the blocking, the blocking baffle 32 adjacent to the initial position of the adjusting motor 31 moves under the push of the adjusting motor 31, and at the same time, the blocking baffle 32 at the initial position is driven by the adjusting block 34 arranged on the side wall to block the connection between the liquid inlet pipe 21 and the negative pressure chamber 24.

[0054] After scraping, the first regulating cylinder 42 recovers, and during the recovery, it drives the first regulating baffle 43 to move upward. When the first regulating baffle 43 moves upward, it controls the baffle 41 to move in the vertical direction, and controls the baffle 41 to open the connection between the main oil storage chamber 2 and the auxiliary oil storage chamber 4, so that the ink in the main oil storage chamber 2 enters the auxiliary oil storage chamber 4 from the connecting port 44.

[0055] Start the second regulating cylinder 5, so that the second regulating cylinder 5 drives the second regulating baffle 51 to move downward, and the second regulating baffle 51 drives the auxiliary fixing plate 52 to move downward, and when the auxiliary fixing plate 52 moves downward, it drives the auxiliary scraper plate 54 to move downward, and adjusts the distance between the auxiliary scraper plate 54 and the screen 12, and starts the blocking cylinder 55, so that the blocking cylinder 55 drives the blocking block 56 to move, so that the liquid in the auxiliary oil storage chamber 4 flows out from the liquid outlet pipe 53, so that the ink is scraped and filled onto the screen 12 for the second time.

[0056] In addition, it should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0057] The above is a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A printing device, comprising a printing press, a printing head slidably connected to the printing press, and a screen fixedly connected below the printing head, characterized in that: A main oil storage chamber for storing excess ink is provided in the printing head, and a liquid inlet pipe is connected to the main oil storage chamber, a main fixing plate is fixedly connected to the liquid inlet pipe, a main scraper plate is slidably connected to the main fixing plate, a negative pressure chamber is provided on the side of the main scraper plate away from the blade back, the negative pressure chamber is connected to the liquid inlet pipe, and the negative pressure chamber is used to recover the ink to the main oil storage chamber; A blocking mechanism for blocking the outflow of ink is provided at the connection between the liquid inlet pipe and the negative pressure chamber; The blocking mechanism includes an adjusting motor slidably connected to the side wall of the main fixed plate, a blocking baffle is slidably connected to the main fixed plate, the blocking baffle is used to block the connection between the liquid inlet pipe and the negative pressure chamber, a reset spring for pushing the blocking baffle to reset is provided at the connection between the blocking baffle and the main fixed plate, and an adjusting block for pushing the adjacent blocking baffle to slide is fixedly connected to the side wall of the blocking baffle; An auxiliary oil storage chamber for allowing excess ink to flow out again is provided on the printing head, a control baffle is slidably connected to the main oil storage chamber, a first regulating cylinder is fixedly connected to the printing head, a first regulating baffle is fixedly connected to the output shaft of the first regulating cylinder, the first regulating baffle is fixedly connected to the main fixed plate, the first regulating baffle can drive the control baffle to slide in the vertical direction, a connecting port that can be connected to the auxiliary oil storage chamber is provided on the main oil storage chamber, and the control baffle can block the connection between the main oil storage chamber and the auxiliary oil storage chamber when moving downward; A second adjusting cylinder is fixedly connected to the printing head, a second adjusting baffle is fixedly connected to the output shaft of the second adjusting cylinder, an auxiliary fixing plate is fixedly connected to the second adjusting baffle, the auxiliary fixing plate is fixedly connected to a liquid outlet pipe connected to the auxiliary oil storage chamber, an auxiliary scraper plate is fixedly connected to the auxiliary fixing plate, a blocking cylinder is fixedly connected to the auxiliary scraper plate, and a blocking block for blocking the liquid outlet pipe to discharge liquid is fixedly connected to the output shaft of the blocking cylinder.

2. A printing device according to claim 1, characterized in that: The bottom surface of the main scraper plate is lower than the bottom surface of the negative pressure chamber.

3. A printing device according to claim 1, characterized in that: A locking bolt is fixedly connected to the main scraper plate, and the locking bolt penetrates the main fixed plate. A locking nut is rotatably connected to the locking bolt and is used to drive the locking bolt to move.

4. A printing device according to claim 1, characterized in that: The liquid outlet pipe and the liquid inlet pipe are both rubber hoses, which can adapt to the movement of the main scraper plate and the auxiliary scraper plate.

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