Pressure uniform distribution type paper vacuum packaging device

Abstract

The invention relates to the technical field of paper packaging, in particular to a uniform pressure distribution type paper vacuum packaging device which is used for solving the problem that the stability of an upper cover in the moving process is affected due to the fact that the upper cover is driven to move through press machines such as a hydraulic rod. The device comprises a machine body, the machine body comprises an upper cover and a base, a pressing mechanism is arranged between the upper cover and the base, the pressing mechanism comprises an L-shaped plate connected to the upper cover and a mounting frame connected to the base, two cam columns are vertically, symmetrically and rotationally connected to the mounting frame, and the horizontal part of the L-shaped plate is located between the two cam columns; the two cam columns synchronously rotate to drive the upper cover to get close to or away from the base; according to the device, the upper cover is driven to move through the cam column, the cam column has enough length, and the contact part of the side wall of the cam column and the L-shaped plate is not one point, so that the upper cover can be ensured to be subjected to uniform driving force to move up and down.

Description

Technical Field

[0001] The present invention relates to the technical field of presses, involving B30B3 / 02, and particularly relates to a paper vacuum packaging device with uniform pressure distribution. Background Art

[0002] In the packaging field, the packaging demand for paper products has always been relatively prominent. In paper packaging, traditional packaging methods have many drawbacks. In the past, when packaging paper, manual packaging or simple mechanical-assisted packaging was mostly used, with low efficiency and it was difficult to ensure the sealing of the packaging. For example, after putting the paper into the packaging bag, manual sealing was relied on, which not only consumed a lot of manpower and time, but also due to differences in manual operations, the sealing quality was uneven, and vacuum packaging could not be effectively achieved, resulting in the paper being easily affected by moisture and contamination, affecting the quality of the paper.

[0003] The upper covers of existing packaging machines are mostly manually opened and closed, with low automation. In some packaging machines with automatic control of the upper cover movement, hydraulic rods and other presses are mostly used for driving. Using this kind of press to drive the upper cover makes the force application range of the upper cover relatively concentrated, and the pressure cannot be evenly distributed on the upper cover, thus affecting the stability of the movement process of the upper cover. Summary of the Invention

[0004] The present invention provides a paper vacuum packaging device with uniform pressure distribution to solve the problem that the stability of the movement process of the upper cover is affected when using a hydraulic rod or other presses to drive the movement of the upper cover.

[0005] To alleviate the above technical problems, the technical solution provided by the present invention lies in:

[0006] A paper vacuum packaging device with uniform pressure distribution includes a machine body, the machine body includes an upper cover and a base, a pressing mechanism is arranged between the upper cover and the base, the pressing mechanism includes an L-shaped plate connected to the upper cover and a mounting frame connected to the base, two cam columns are vertically and symmetrically rotatably connected to the mounting frame, the horizontal part of the L-shaped plate is located between the two cam columns, and the synchronous rotation of the two cam columns can drive the upper cover to approach or move away from the base.

[0007] Furthermore, gears are connected to the ends of both cam columns, a chain is drivingly connected between the two gears, and any one of the two gears on the same side is connected to the output end of an external driving motor.

[0008] Furthermore, the mounting frame is rotatably connected to the base, two hydraulic cylinders are fixedly connected to the base, the two hydraulic cylinders are symmetrically arranged at the bottom of the mounting frame, and the output ends of the two hydraulic cylinders are both abutted against the bottom of the mounting frame.

[0009] Further, it further includes a paper pressing mechanism. The paper pressing mechanism includes a pressing plate. The upper surface of the pressing plate is connected with a hollow rod. The hollow rod is slidably connected to the upper cover. A first tension spring is connected between the top end of the hollow rod and the upper cover. When the upper cover moves downward, the pressing plate fits on the upper surface of the packaging bag containing the paper, so that the packaging bag is tightly attached to the paper.

[0010] Further, the paper pressing mechanism further includes four second air cylinders connected to the four corners of the pressing plate. The output ends of the four second air cylinders are all connected with expansion blocks. After the pressing plate moves downward and fits on the packaging bag containing the paper, the second air cylinders extend.

[0011] Further, the paper pressing mechanism further includes a sliding rod slidably arranged in the hollow rod. The hollow rod is communicated with the four second air cylinders. When the hollow rod moves upward, the sliding rod slides downward relative to the hollow rod, so that the air in the hollow rod is transferred to the four second air cylinders.

[0012] Further, a second tension spring is connected between the expansion block and the pressing plate. When the upper cover moves upward, the second tension spring pulls the expansion block to reset, so that the sliding rod slides upward relative to the hollow rod.

[0013] Further, a first support is fixedly connected to the upper cover. The top of the first support is slidably connected with a second support. A third tension spring is connected between the second support and the first support. The sliding rod penetrates through the first support and abuts against the second support.

[0014] Further, a tightening mechanism is arranged in the base. The tightening mechanism includes an L-shaped seat. Tightening blocks are slidably connected to two adjacent surfaces of the L-shaped seat. The L-shaped seat can linearly slide along two directions of its L-shaped side. After the L-shaped seat slides, the two tightening blocks both contact the corners of the packaging bag containing the paper. Subsequently, the two tightening blocks approach each other to tighten the packaging bag, so that the packaging bag is tightly attached to the paper.

[0015] Further, the tightening mechanism further includes two first air cylinders connected to the base. The output ends of the two first air cylinders respectively abut against the two right-angled sides of the L-shaped seat.

[0016] The beneficial effects of the present invention are analyzed as follows:

[0017] A paper vacuum packaging device with uniform pressure distribution includes a machine body. The machine body includes an upper cover and a base. A pressing mechanism is arranged between the upper cover and the base. The pressing mechanism includes an L-shaped plate connected to the upper cover and a mounting frame connected to the base. Two cam columns are vertically and symmetrically rotatably connected to the mounting frame. The horizontal part of the L-shaped plate is located between the two cam columns. The synchronous rotation of the two cam columns can drive the upper cover to approach or move away from the base.

[0018] Place the paper in the packaging bag, then put the packaging bag into the base, and start the pressing mechanism. At this time, the two cam columns rotate synchronously and at the same speed. During the operation of the machine body, the upper cam column rotates to apply a downward pressure to the L-shaped plate, and the pressing mechanism is divided into two groups and symmetrically arranged on both sides of the base, so as to drive the upper cover to move vertically downward. After the upper cover contacts the base, the rotation of the cam column is blocked. When it is necessary to open the upper cover, control the cam column to rotate in the reverse direction. At this time, the lower cam column rotates to apply an upward lifting force to the L-shaped plate, causing the upper cover to move vertically upward. Since the cam column has a sufficient length and the contact part of its side wall with the L-shaped plate is not a single point, it can ensure that the upper cover is driven evenly to move up and down. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the related art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 Structural schematic diagram of the whole of the present invention;

[0021] Figure 2 Cross-sectional view of the present invention in the state where the upper cover has not moved down;

[0022] Figure 3 Cross-sectional view of the present invention in the state after the upper cover has moved down;

[0023] Figure 4 Structural schematic diagram of the pressing plate of the present invention;

[0024] Figure 5 Structural schematic diagram of the tightening mechanism of the present invention;

[0025] Figure 6 Structural schematic diagram of the L-shaped seat of the present invention;

[0026] Figure 7 Structural schematic diagram of the cam column of the present invention.

[0027] Icon:

[0028] 100, body; 110, base; 120, upper cover; 130, guide post; 140, upper seal; 150, lower seal; 200, paper pressing mechanism; 210, hollow rod; 220, first tension spring; 230, pressing plate; 240, second cylinder; 241, second tension spring; 250, expansion block; 260, slide bar; 270, first bracket; 280, second bracket; 281, third tension spring; 290, pressure sensor; 300, tightening mechanism; 310, L-shaped seat; 320, tightening block; 330, piston cylinder; 331, first piston plate; 332, second piston plate; 333, first spring; 334, second spring; 340, air pipe; 350, first cylinder; 360, pressing rod; 400, pressing mechanism; 410, mounting bracket; 420, cam column; 430, gear; 440, hydraulic cylinder; 450, L-shaped plate. Detailed implementation manners

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0032] Embodiment, as Figures 1-7As shown in the figure, a pressure evenly distributed paper vacuum packaging device includes a machine body 100, the machine body 100 includes an upper cover 120 and a base 110, a pressing mechanism 400 is arranged between the upper cover 120 and the base 110, the pressing mechanism 400 includes an L-shaped plate 450 connected to the upper cover 120 and a mounting frame 410 connected to the base 110, two cam columns 420 are vertically and symmetrically rotatably connected to the mounting frame 410, the horizontal part of the L-shaped plate 450 is located between the two cam columns 420, and the synchronous rotation of the two cam columns 420 can drive the upper cover 120 to approach or move away from the base 110.

[0033] The working mechanism of the pressure evenly distributed paper vacuum packaging device provided in this embodiment:

[0034] Place the paper in the packaging bag, then put the packaging bag into the base 110, start the pressing mechanism 400, at this time the two cam columns 420 rotate synchronously, and the rotation speeds of the two cam columns 420 are the same. During the working stage of the machine body 100, the upper cam column 420 rotates to apply a downward pressure to the L-shaped plate 450, and the pressing mechanism 400 is in two groups and symmetrically arranged on both sides of the base 110, so as to be able to drive the upper cover 120 to move vertically downward. After the upper cover 120 contacts the base 110, the rotation of the cam column 420 is blocked. When it is necessary to open the upper cover 120, control the cam column 420 to rotate in the reverse direction. At this time, the lower cam column 420 rotates to apply an upward lifting force to the L-shaped plate 450, so that the upper cover 120 moves vertically upward. Since the cam column 420 has a sufficient length, and the contact part of its side wall with the L-shaped plate 450 is not a point, it can ensure that the upper cover 120 is driven evenly to move up and down.

[0035] In an alternative embodiment of this example, preferably:

[0036] Gears 430 are connected to the ends of both cam columns 420, a chain is drivingly connected between the two gears 430, and any one of the two gears 430 on the same side is connected to the output end of an external drive motor.

[0037] The two cam columns 420 are drivingly connected through a chain and gears 430, ensuring that when one of the cam columns 420 is driven to rotate, the other can rotate synchronously.

[0038] In an alternative embodiment of this example, preferably:

[0039] The mounting frame 410 is rotatably connected to the base 110, two hydraulic cylinders 440 are fixedly connected to the base 110, the two hydraulic cylinders 440 are symmetrically arranged at the bottom of the mounting frame 410, and the output ends of the two hydraulic cylinders 440 are both abutted against the bottom of the mounting frame 410.

[0040] There are two sensors at the contact parts between the bottom of the mounting bracket 410 and the output ends of the two hydraulic cylinders 440. The sensors are used to detect the pressure between the two hydraulic cylinders 440 and the mounting bracket 410. If the pressure values detected by the two sensors have a large difference, it indicates that the upper cover 120 is tilted during the movement. As Figure 1 shown, if the upper cover 120 offsets towards the lower seal 150, the upper cover 120 will drive the mounting bracket 410 to swing towards the lower seal 150 through the L-shaped plate 450. At this time, the sensor near the lower seal 150 detects an increase in the pressure value, so the hydraulic cylinder 440 here extends, and by pushing the mounting bracket 410 to swing in the opposite direction to straighten the upper cover 120;

[0041] The hydraulic cylinder 440 straightens the upper cover 120 by extending multiple times. The extension distance each time is short. After the hydraulic cylinder 440 extends slightly, the cam column 420 continues to rotate, and the sensor continues to detect the pressure. After the pressure values of the two sensors have a small deviation, the hydraulic cylinder 440 no longer extends.

[0042] Regarding the structure of the tightening mechanism 300, specifically:

[0043] A tightening mechanism 300 is arranged inside the base 110. The tightening mechanism 300 includes an L-shaped seat 310. Tightening blocks 320 are slidably connected to two adjacent surfaces of the L-shaped seat 310. The L-shaped seat 310 can linearly slide in two directions along its L-shaped side. After the L-shaped seat 310 slides, the two tightening blocks 320 both contact the corners of the packaging bag containing the paper. Subsequently, the two tightening blocks 320 approach each other to tighten the packaging bag, so that the packaging bag closely adheres to the paper.

[0044] A lower seal 150 and an upper seal 140 are respectively connected to the base 110 and the upper cover 120. The bag mouth of the packaging bag is placed on the upper part of the lower seal 150. The guide post 130 is connected to the base 110 and penetrates through the upper cover 120. The upper cover 120 slides down along the base 110, so that the upper seal 140 presses the bag mouth of the packaging bag on the lower seal 150. When the upper seal 140 and the lower seal 150 approach each other, the space between the base 110 and the upper cover 120 where the bag mouth of the packaging bag is located forms a vacuum space. An external vacuum pump is connected to this space, so starting the external vacuum pump can evacuate this space, and the air in the packaging bag is extracted. Subsequently, the vacuuming operation of the packaging bag is completed. In addition, hot melt strips are arranged on both the upper seal 140 and the lower seal 150. When the operating power of the vacuum pump reaches stability, it indicates that the vacuuming has been completed. At this time, the hot melt strips operate and seal the packaging bag;

[0045] When the upper cover 120 approaches the base 110, the two L-shaped seats 310 away from the lower seal 150 approach and fit against the two corners of the packaging bag with the paper inside. After the L-shaped seats 310 fit against the packaging bag with the paper inside, if the packaging bag with the paper inside does not stick to the lower seal 150, the L-shaped seats 310 continue to slide and push the packaging bag with the paper inside until it sticks to the lower seal 150. In addition, to prevent relative displacement between the paper and the packaging bag when the packaging bag with the paper inside is being pushed, when placing, the paper at the mouth of the packaging bag should be close to the lower seal 150;

[0046] When the packaging bag with the paper inside is fixed by the lower seal 150 and the two L-shaped seats 310, the upper seal 140 then presses on the lower seal 150 to fix the mouth of the packaging bag. Subsequently, the two sets of tightening blocks 320 on the two L-shaped seats 310 approach each other, and the frictional force between the tightening blocks 320 and the packaging bag acts to pull the packaging bag, so that the packaging bag is tightened, so that the subsequent packaging bag can be evenly attached to the paper when being evacuated, avoiding local wrinkles when the packaging bag is evacuated, resulting in the internal paper being pressed to form indentations, which is inconvenient for subsequent use.

[0047] Regarding the structure of the tightening mechanism 300, specifically:

[0048] The tightening mechanism 300 further includes two first cylinders 350 connected to the base 110, and the output ends of the two first cylinders 350 respectively abut against the two right-angled sides of the L-shaped seat 310.

[0049] The two first cylinders 350 jointly drive one L-shaped seat 310, and the output end of the first cylinder 350 is not fixedly connected to the L-shaped seat 310, so that the movement of the L-shaped seat 310 is not restricted, and each first cylinder 350 can drive the L-shaped seat 310 to slide along one of the right-angled side directions.

[0050] In an alternative embodiment of the present embodiment, preferably:

[0051] The tightening mechanism 300 further includes a piston cylinder 330, a first piston plate 331 and a second piston plate 332 are slidably connected in the piston cylinder 330, a trachea 340 is connected through the second piston plate 332, the trachea 340 communicates with the two first cylinders 350 and the space between the first piston plate 331 and the second piston plate 332, and a pressure rod 360 is connected to the upper cover 120, and the bottom end of the pressure rod 360 abuts against the first piston plate 331.

[0052] When the upper cover 120 moves downward, it drives the pressure rod 360 to move downward synchronously. At this time, the pressure rod 360 presses on the first piston plate 331, so that the first piston plate 331 approaches the second piston plate 332, and the air between the two is transmitted to the first cylinder 350 through the air pipe 340, causing the corresponding two first cylinders 350 to extend. When the extension of one of the first cylinders 350 is blocked, the other unblocked first cylinder 350 continues to extend, so as to ensure that the L-shaped seat 310 can closely adhere to the corner of the packaging bag containing the paper.

[0053] In an alternative embodiment of the present embodiment, preferably:

[0054] A first spring 333 is connected between the first piston plate 331 and the second piston plate 332, and a second spring 334 is connected between the second piston plate 332 and the bottom end of the piston cylinder 330. The elastic force of the second spring 334 is greater than that of the first spring 333.

[0055] In order to adapt to the fixation of papers of different sizes and the tightening of the packaging bag within a certain limit, when the L-shaped seat 310 does not fix the packaging bag containing the paper, the first piston plate 331 is pressed to squeeze the first spring 333, causing the first spring 333 to shorten. At this time, the first piston plate 331 approaches the second piston plate 332, and air is transmitted into the first cylinder 350. When the L-shaped seat 310 abuts against the corner of the packaging bag containing the paper, if the pressure rod 360 is still moving downward, after the extension of the first cylinder 350 is blocked, the first piston plate 331 no longer approaches the second piston plate 332. At this time, the second piston plate 332 presses the second spring 334, so that the downward movement of the pressure rod 360 is not interfered, and at the same time, the first cylinder 350 no longer extends.

[0056] Regarding the structure of the paper pressing mechanism 200, specifically:

[0057] The paper pressing mechanism 200 includes a pressing plate 230. The upper surface of the pressing plate 230 is connected with a hollow rod 210. The hollow rod 210 is slidably connected to the upper cover 120. A first tension spring 220 is connected between the top end of the hollow rod 210 and the upper cover 120. When the upper cover 120 moves downward, the pressing plate 230 fits on the upper surface of the packaging bag containing the paper, so that the packaging bag is closely attached to the paper.

[0058] When the upper cover 120 moves downward, the pressing plate 230 first contacts the upper surface of the packaging bag containing the paper. At this time, the pressing plate 230 is blocked, and the hollow rod 210 slides upward relative to the upper cover 120, causing the first tension spring 220 to be stretched. The first tension spring 220 exerts a reaction force on the upper cover 120, so that the pressing plate 230 can be tightly pressed on the upper surface of the packaging bag containing the paper, and the packaging bag is attached to the upper surface of the paper.

[0059] In an alternative embodiment of the present embodiment, preferably:

[0060] The paper pressing mechanism 200 further includes four second air cylinders 240 connected to the four corners of the pressing plate 230. The output ends of the four second air cylinders 240 are all connected with expansion blocks 250. After the pressing plate 230 moves downward and fits against the packaging bag containing the paper, the second air cylinders 240 extend, and the second air cylinders 240 stop extending after the expansion blocks 250 abut against the two tightening blocks 320.

[0061] After the pressing plate 230 presses on the packaging bag containing the paper, the upper cover 120 continues to move downward. At this time, the four second air cylinders 240 extend, pushing the four expansion blocks 250 respectively towards the four corners of the packaging bag containing the paper, so that the four expansion blocks 250 smooth the packaging bag not pressed by the pressing plate 230, ensuring that when a relatively large paper is being packaged, the packaging bag can still adhere to the surface of the internal paper. The second air cylinders 240 stop extending after the expansion blocks 250 move to contact the tightening blocks 320.

[0062] In an alternative embodiment of the present embodiment, preferably:

[0063] The paper pressing mechanism 200 further includes a sliding rod 260 sliding inside the hollow rod 210. The hollow rod 210 is communicated with the four second air cylinders 240. When the hollow rod 210 moves upward, the sliding rod 260 slides downward relative to the hollow rod 210, so that the air inside the hollow rod 210 is transferred to the four second air cylinders 240.

[0064] After the pressing plate 230 contacts the packaging bag, the sliding rod 260 slides towards the inside of the hollow rod 210. At this time, the air inside the hollow rod 210 is transferred to the four second air cylinders 240, causing the four second air cylinders 240 to extend.

[0065] In an alternative embodiment of the present embodiment, preferably:

[0066] A second tension spring 241 is connected between the expansion block 250 and the pressing plate 230. When the upper cover 120 moves upward, the second tension spring 241 pulls the expansion block 250 to reset, so that the sliding rod 260 slides upward relative to the hollow rod 210.

[0067] When the sliding rod 260 slides upward relative to the hollow rod 210, the second tension spring 241 pulls the expansion block 250 to reset. At this time, the second air cylinder 240 shortens, so that the air inside the second air cylinder 240 flows back to the hollow rod 210.

[0068] In an alternative embodiment of the present embodiment, preferably:

[0069] A first support 270 is fixedly connected to the upper cover 120. The top of the first support 270 is slidably connected with a second support 280. A third tension spring 281 is connected between the second support 280 and the first support 270. The sliding rod 260 passes through the first support 270 and abuts against the second support 280.

[0070] When the upper cover 120 moves downward, the pressing plate 230 contacts the packaging bag containing the built-in paper. Subsequently, the upper cover 120 continues to move upward, so that the hollow rod 210 and the sliding rod 260 inside it approach the second bracket 280. At this time, the second bracket 280 blocks the sliding rod 260, causing the sliding rod 260 to slide into the interior of the hollow rod 210. The sliding rod 260 and the hollow rod 210 have sufficient length so that the expansion block 250 has contacted the tightening block 320 before the upper cover 120 covers the base 110, ensuring that the packaging bag containing the built-in paper can be smoothed. After the expansion block 250 contacts the tightening block 320, the upper cover 120 continues to move downward. At this time, the sliding rod 260 no longer slides into the interior of the hollow rod 210. Thus, at this time, the sliding rod 260 pushes up the second bracket 280, causing the second bracket 280 to move upward against the pulling force of the third tension spring 281, ensuring that the downward movement of the upper cover 120 is not interfered with.

[0071] In an alternative embodiment of the present example, preferably:

[0072] Both of the two tightening blocks 320 slide on the L-shaped seat 310 through electric sliders. A pressure sensor 290 is connected to the second bracket 280. When the expansion block 250 abuts against the tightening block 320, the pressure applied by the sliding rod 260 to the pressure sensor 290 suddenly increases. Thus, the two electric sliders respectively drive the two tightening blocks 320 to approach each other.

[0073] When the second bracket 280 is pushed up, the pressure received by the pressure sensor 290 applied by the sliding rod 260 on the second bracket 280 suddenly increases. After the pressure of the pressure sensor 290 suddenly increases, the control system controls the tightening blocks 320 slidably connected to the L-shaped seat 310 through electric sliders to slide, so that the adjacent two tightening blocks 320 approach each other to tighten the packaging bag, and the two tightening blocks 320 clamp the corners of the packaging bag, making it difficult for the packaging bag to wrinkle again during subsequent vacuuming.

[0074] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure-uniformly distributed paper vacuum packaging device, comprising a body (100), wherein the body (100) comprises an upper cover (120) and a base (110), characterized in that: A pressing mechanism (400) is provided between the upper cover (120) and the base (110), and the pressing mechanism (400) comprises an L-shaped plate (450) connected to the upper cover (120) and a mounting frame (410) connected to the base (110), two cam columns (420) are vertically symmetrically rotatably connected to the mounting frame (410), a horizontal portion of the L-shaped plate (450) is located between the two cam columns (420), and the synchronous rotation of the two cam columns (420) can drive the upper cover (120) to approach or move away from the base (110).

2. The pressure uniform distribution type paper vacuum packaging device according to claim 1, characterized in that: The ends of the two cam posts (420) are both connected to gears (430), a chain is transmission-connected between the two gears (430), and any one of the two gears (430) on the same side is connected to the output end of an external drive motor.

3. The pressure uniform distribution type paper vacuum packaging device according to claim 2, characterized in that: The mounting frame (410) is rotatably connected to the base (110); two hydraulic cylinders (440) are fixedly connected to the base (110); the two hydraulic cylinders (440) are symmetrically arranged at the bottom of the mounting frame (410), and the output ends of the two hydraulic cylinders (440) are both in contact with the bottom of the mounting frame (410).

4. The pressure uniform distribution type paper vacuum packaging device according to claim 1, characterized in that: The invention also comprises a paper pressing mechanism (200), wherein the paper pressing mechanism (200) comprises a pressing plate (230), the upper surface of the pressing plate (230) is connected with a hollow rod (210), the hollow rod (210) is slidably connected to the upper cover (120), a first tension spring (220) is connected between the top end of the hollow rod (210) and the upper cover (120), and when the upper cover (120) moves downward, the pressing plate (230) is attached to the upper surface of a packaging bag containing paper therein, so that the packaging bag is tightly attached to the paper.

5. The pressure uniform distribution type paper vacuum packaging device according to claim 4, characterized in that: The paper pressing mechanism (200) further comprises four second cylinders (240) connected to the four corners of the pressing plate (230), the output ends of the four second cylinders (240) are all connected to expansion blocks (250), and after the pressing plate (230) moves downward and fits onto a packaging bag containing paper, the second cylinders (240) extend.

6. The pressure uniform distribution type paper vacuum packaging device according to claim 5, characterized in that: The paper pressing mechanism (200) further comprises a sliding rod (260) sliding inside the hollow rod (210), wherein the hollow rod (210) is connected to the four second air cylinders (240), and when the hollow rod (210) moves upward, the sliding rod (260) slides relatively downward inside the hollow rod (210), so that the air inside the hollow rod (210) is transferred to the four second air cylinders (240).

7. The pressure uniform distribution type paper vacuum packaging device according to claim 6, characterized in that: A second tension spring (241) is connected between the expansion block (250) and the pressure plate (230). When the upper cover (120) moves upward, the second tension spring (241) pulls the expansion block (250) to return to its original position, so that the sliding rod (260) slides upward relative to the hollow rod (210).

8. The pressure uniform distribution type paper vacuum packaging device according to claim 7, characterized in that: A first bracket (270) is fixedly connected to the upper cover (120); a second bracket (280) is slidably connected to the top of the first bracket (270); a third tension spring (281) is connected between the second bracket (280) and the first bracket (270); and the sliding rod (260) passes through the first bracket (270) and abuts against the second bracket (280).

9. The pressure uniform distribution type paper vacuum packaging device according to claim 8, characterized in that: A tightening mechanism (300) is arranged inside the base (110), and the tightening mechanism (300) comprises an L-shaped seat (310), and tightening blocks (320) are slidably connected to two adjacent surfaces of the L-shaped seat (310), and the L-shaped seat (310) can slide linearly along two directions of its L-shaped edge respectively, and after the L-shaped seat (310) slides, the two tightening blocks (320) both contact the corners of the packaging bag with paper inside, and then the two tightening blocks (320) approach each other to tighten the packaging bag, so that the packaging bag is tightly attached to the paper.

10. The pressure uniform distribution type paper vacuum packaging device according to claim 9, characterized in that: The tightening mechanism (300) further comprises two first cylinders (350) connected to the base (110), and the output ends of the two first cylinders (350) respectively abut against two right-angled sides of the L-shaped seat (310).

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