Ring type continuous heat sealing device

Abstract

The invention discloses an annular continuous heat sealing device which comprises a rack, a main conveying belt used for conveying workpieces to be subjected to hot pressing and a conveying driving device used for driving the main conveying belt to operate are arranged on the rack, a vertical plate is arranged above the main conveying belt, and an annular rail is arranged on the periphery of the vertical plate. The annular track comprises a lower straight line section, a left semicircular section, an upper straight line section and a right semicircular section which are connected in sequence; a plurality of sliding block assemblies are connected to the annular rail in a sliding mode, the sliding block assemblies are provided with hot pressing devices capable of conducting hot pressing on workpieces on the main conveying belt when the sliding block assemblies operate to the lower straight line segment, and a main driving device used for driving the sliding block assemblies to slide along the annular rail is arranged between the sliding block assemblies and the vertical plate. A conductive structure used for supplying power to the hot pressing device is further arranged between the sliding block assembly and the annular rail. The heat sealing device has the advantage of being capable of achieving continuous, high-speed, efficient and stable heat sealing.

Description

Technical Field

[0001] The present invention relates to the field of heat sealing technology, in particular to a ring-type continuous heat sealing device. Background Art

[0002] In the prior art, conventional heat-sealing devices, especially linear heat-sealing devices widely used in packaging, bag-making, and other fields, usually use a reciprocating motion to perform heat sealing. Specifically, the working process of such a device generally includes the following steps: first, the heat press head (or heat press plate) is lowered from a raised state to contact the packaging material to be sealed (such as a film); then, while maintaining contact with the material and applying a certain sealing pressure, the heat press head moves forward along the material (or relative material) a preset distance to complete heating and pressure application in the sealing area; then, the heat press head is lifted upward and separated from the material; finally, the heat press head moves back quickly to its initial position, ready for the next heat-sealing cycle.

[0003] However, this linear reciprocating heat sealing device has obvious shortcomings. First, since the hot pressure head must complete movement in both the forward and backward directions, the backward return process does not produce an effective heat sealing effect and is a purely auxiliary stroke, which greatly takes up the time of the working cycle. This results in the overall heat sealing speed of the equipment being limited and difficult to further improve, thereby affecting production efficiency, especially in application scenarios that require high-speed and large-scale production. Secondly, frequent starting, stopping and reversing movements bring greater impact and wear to the mechanical structure of the equipment, such as the drive mechanism, guide rails, connectors, etc., which not only increases the maintenance cost of the equipment, but also shortens the service life of the equipment. Furthermore, in order to achieve precise reciprocating motion and stable sealing pressure control, the transmission and control system of the linear heat sealing device is usually more complex and the manufacturing cost is relatively high. In addition, for continuous feeding packaging production lines, this intermittent heat sealing method requires complex synchronous control to ensure the relative stillness or synchronous movement of the materials during heat sealing, which increases the complexity of the system and the difficulty of adjustment.

[0004] Therefore, it is necessary to further improve and perfect the existing technology to overcome these shortcomings, and the present invention is made based on this situation. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a ring-type continuous heat sealing device that can achieve continuous, high-speed, efficient and stable heat sealing.

[0006] The present invention is achieved through the following technical solutions:

[0007] In order to solve the above technical problems, the present invention provides a ring-type continuous heat sealing device, comprising a frame, the frame is provided with a main conveyor belt for transporting workpieces to be hot-pressed, and a conveying drive device for driving the operation thereof, a vertical plate is provided above the main conveyor belt, the periphery of the vertical plate is provided with a circular track, the circular track includes a lower straight section, a left semicircular section, an upper straight section, and a right semicircular section connected in sequence; a plurality of slider assemblies are slidably connected to the circular track, the slider assembly is provided with a hot pressing device that can hot press the workpiece on the main conveyor belt when it runs to the lower straight section, a main drive device for driving it to slide along the circular track is provided between the slider assembly and the vertical plate, and a conductive structure for supplying power to the hot pressing device is also provided between the slider assembly and the circular track.

[0008] In order to further solve the technical problem to be solved by the present invention, in a ring-type continuous heat sealing device provided by the present invention, the slider assembly includes a bracket, the bracket is rotatably connected to a roller group that cooperates with the ring track, the bracket is fixedly connected to a fixed plate, and an upper movable plate that can be raised and lowered is movably connected above the fixed plate. The upper surface of the upper movable plate abuts the side of the vertical plate, and a first elastic reset member that elastically presses the upper movable plate upward is provided between the upper movable plate and the fixed plate. The upper movable plate is fixedly connected to a lower movable plate located below the fixed plate, and the hot pressing device is provided on the lower movable plate.

[0009] In order to further solve the technical problem to be solved by the present invention, the present invention provides a ring-type continuous heat sealing device, in which the hot pressing device includes a hot pressing plate movably connected to a lower movable plate and capable of being raised and lowered, and a heating element arranged in the hot pressing plate, and a second elastic reset member for elastically pressing the hot pressing plate downward is provided between the hot pressing plate and the lower movable plate.

[0010] In order to further solve the technical problem to be solved by the present invention, in a ring-type continuous heat sealing device provided by the present invention, the upper surface of the upper movable plate is rotatably connected to a plurality of rollers abutting against the side surfaces of the vertical plate.

[0011] In order to further solve the technical problem to be solved by the present invention, in a ring-type continuous heat sealing device provided by the present invention, the side surface of the vertical plate includes a lower side surface, a left semicircular side surface, an upper side surface and a right semicircular side surface connected in sequence, and the vertical distance D from the lower side surface of the vertical plate to the center O of the right semicircular side surface is greater than the radius R of the right semicircular side surface.

[0012] In order to further solve the technical problem to be solved by the present invention, the present invention provides a ring-type continuous heat sealing device, in which the conductive structure includes carbon brushes provided on each slider, and a conductive sheet provided on the vertical plate, the conductive sheet includes parallel cathode wires and anode wires, the conductive sheet is electrically connected to a power supply, the carbon brush is electrically connected to the hot pressing device, and the free end of the carbon brush can elastically abut against the conductive sheet.

[0013] In order to further solve the technical problem to be solved by the present invention, in a ring-type continuous heat sealing device provided by the present invention, the conductive sheet includes a hot pressing section arranged parallel to the lower straight section.

[0014] In order to further solve the technical problem to be solved by the present invention, in a ring-type continuous heat sealing device provided by the present invention, the conductive sheet further includes a preheating section arranged parallel to the right semicircular section.

[0015] In order to further solve the technical problem to be solved by the present invention, in a ring-type continuous heat sealing device provided by the present invention, the main driving device includes a driving wheel and a driving wheel rotatably connected to the left and right ends of the vertical plate, a driving motor for driving the driving wheel to rotate, and a chain or belt connected between the driving wheel and the driving wheel, and each of the slider assemblies is connected to the chain or belt at intervals.

[0016] In order to further solve the technical problem to be solved by the present invention, in a ring-type continuous heat sealing device provided by the present invention, a cross beam is further provided on the frame, the vertical plate is slidably connected to the cross beam along the transverse direction of the main conveyor belt, and a lateral adjustment device is provided on the vertical plate for driving its lateral translation.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The core innovation of the present invention's circular continuous heat-sealing device lies in its radical departure from the reciprocating motion of conventional linear heat-sealing devices. Instead, it innovatively employs multiple heat-pressing devices that continuously cycle along a circular track. By integrating the heat-pressing devices into the slider assembly and cleverly utilizing the specific contours of the vertical plate's side surfaces in conjunction with elastic return elements, the heat-pressing devices automatically and cyclically press down (in the hot-pressing area) and lift up (in the non-hot-pressing area) during their circular motion, eliminating the need for separate lifting, pressing, and returning mechanisms. Compared to existing technologies, this circular continuous motion design completely eliminates the non-working stroke, significantly improving hot-pressing speed and production efficiency, achieving true continuous heat sealing. Furthermore, the continuous motion pattern eliminates frequent starts, stops, and reversals, significantly reducing mechanical wear and improving the stability and service life of the device. Furthermore, the addition of a lateral adjustment device further enhances the device's adaptability and accuracy to workpieces of varying sizes or positions. Therefore, the present invention offers significant technological advancements and practical value in terms of heat-sealing speed, efficiency, reliability, maintenance costs, and adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0020] Figure 1 This is one of the three-dimensional structural diagrams of the present invention;

[0021] Figure 2 This is the second schematic diagram of the three-dimensional structure of the present invention;

[0022] Figure 3 It is an exploded schematic diagram of the vertical plate;

[0023] Figure 4 It is a partial structural diagram of the right end of the vertical plate;

[0024] Figure 5 Schematic diagram of the three-dimensional structure of the slider assembly;

[0025] Figure 6 is a cross-sectional view of the slider assembly;

[0026] Figure 7 is an exploded schematic diagram of the slider assembly;

[0027] Figure 8 It is a schematic cross-sectional view of the vertical plate. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0029] like Figures 1 to 8As shown, the present invention provides a ring-type continuous heat-sealing device. Unlike conventional heat-pressing devices that employ linear reciprocating motion, this device utilizes a heat-pressing assembly that can continuously move in a ring-type motion. This device achieves a faster, more efficient, and more continuous heat-sealing process while reducing the mechanical impact and wear caused by the reciprocating motion.

[0030] Specifically, the loop-type continuous heat-sealing device of the present invention includes a frame 1, on which is mounted a main conveyor belt 2 for carrying and conveying workpieces to be hot-pressed. The main conveyor belt 2 is driven by a conveyor drive device 21 (e.g., consisting of a motor, a speed reducer, and a transmission mechanism) to continuously convey the packaging materials or products to be hot-pressed at a predetermined speed.

[0031] On the frame 1, preferably above the main conveyor belt 2, a transverse support structure, such as a crossbeam 9, is also provided. The crossbeam 9 extends along the transverse direction of the main conveyor belt 2 (i.e., the horizontal direction perpendicular to the movement direction of the main conveyor belt 2). On the crossbeam 9, the vertical plate 3 is slidably connected. The vertical plate 3 is arranged perpendicular to the plane of the main conveyor belt 2 and serves as a core component for guiding and supporting the annular motion assembly. Through this sliding connection method, the vertical plate 3 can be translated along the crossbeam 9 in the transverse direction of the main conveyor belt 2. In order to achieve precise adjustment of the transverse position of the vertical plate 3, a transverse adjustment device for driving its transverse translation is also provided on the vertical plate 3.

[0032] Furthermore, in order to achieve high-precision and stable lateral position adjustment, the lateral adjustment device includes a ball screw pair 91 arranged between the vertical plate 3 and the frame 1 (or a support member fixed to the frame 1). The ball screw pair 91 has the function of converting rotational motion into precise linear motion. One end of the screw (or nut, depending on the specific installation method) of the ball screw pair 91 is fixedly connected to the frame 1, and the other end is connected to the vertical plate 3 through the nut (or screw). The screw of the ball screw pair 91 (or the rotating shaft connected to the screw) is provided with an adjustment handwheel 92 for manually adjusting the lateral position of the vertical plate 3. By rotating the adjustment handwheel 92, the screw of the ball screw pair 91 is driven to rotate, thereby driving the nut that cooperates with the screw and the vertical plate 3 connected to the nut to achieve precise lateral translation along the crossbeam 9. This manual adjustment method is simple to operate and low in cost, and is suitable for positioning when installing, debugging or replacing workpieces of different specifications.

[0033] By setting up a lateral adjustment device, the lateral position of the entire ring-type heat sealing mechanism (including the vertical plate 3, the annular track 4 and the slider assembly 5) relative to the workpiece on the main conveyor belt 2 can be conveniently and accurately adjusted to ensure that the hot pressing plate 61 can be accurately aligned with the sealing area of ​​the workpiece, thereby ensuring the sealing quality and improving the adaptability of the equipment to workpieces of different sizes or position deviations.

[0034] A closed ring track structure, namely the ring track 4, is fixed or integrated around the periphery of the vertical plate 3. The ring track 4 is preferably a closed track including straight line segments and circular arc segments. Specifically, in this embodiment, Figure 3 As shown, the annular track 4 comprises a lower straight segment 41, a left semicircular segment 42, an upper straight segment 43, and a right semicircular segment 44, which are connected in sequence. These track segments together constitute the motion path of the slider assembly.

[0035] Several slider assemblies 5 are slidably connected to the circular track 4. These slider assemblies 5 are mobile units that carry the hot pressing device and are capable of continuous circular motion along the circular track 4. Each slider assembly 5 is equipped with a hot pressing device 6, which is designed to apply hot pressing to the workpieces on the main conveyor belt 2 when the slider assembly 5 moves to the lower straight section 41 of the circular track 4 (i.e., the area directly above and parallel to the main conveyor belt 2).

[0036] To drive these slider assemblies 5 along the circular track 4, a main drive device 7 is installed between the slider assemblies 5 and the vertical plate 3. The main drive device 7 provides power to the slider assemblies, enabling them to operate at a predetermined speed and trajectory. Furthermore, to provide continuous and stable power to the hot press 6 during the movement of the slider assemblies 5, a conductive structure 8 is installed between the slider assemblies 5 and the circular track 4 area of ​​the vertical plate 3.

[0037] The core of the present invention lies in the use of a circularly movable hot pressing device 6, integrated into a slider assembly 5 that continuously operates along a circular track 4. By arranging multiple slider assemblies 5 for cyclical movement along the circular track, multiple slider assemblies successively enter the lower linear segment 41, thereby achieving continuous hot pressing of workpieces continuously conveyed on the main conveyor belt 2. This avoids the time occupied by non-working travel, such as the raising and retreating of the hot pressing head in conventional linear reciprocating heat sealing devices, significantly improving hot pressing speed and production efficiency. Furthermore, because the hot pressing device primarily performs continuous circular motion, frequent starting, stopping, and direction-changing shocks are avoided, reducing mechanical wear and improving the stability and service life of the equipment.

[0038] In order to achieve automatic lifting and pressing of the hot pressing device 6 when it moves to different track sections and to provide stable heat sealing pressure, the slider assembly 5 and the hot pressing device 6 have a more sophisticated structural design.

[0039] Specifically, the slider assembly 5 includes a bracket 51, on which is rotatably connected a roller assembly 52 that cooperates with the annular track 4. The roller assembly 52 is composed of, for example, a plurality of bearing rollers, and by cooperating with the inner and outer sides or the upper and lower sides of the annular track 4, the slider assembly 5 can slide and guide smoothly on the track.

[0040] A fixed plate 53 is fixedly connected to the bracket 51. The fixed plate 53 is a base for the internal structure of the slider assembly. A liftable upper movable plate 54 is movably connected above the fixed plate 53. The upper movable plate 54 is a key component for realizing the lifting / pressing down of the hot pressing head. The upper surface of the upper movable plate 54 is designed to abut against the side of the vertical plate 3. The vertical position of the upper movable plate 54 can be controlled by changing the specific shape of the side of the vertical plate 3. In order to ensure that the upper movable plate 54 can closely follow the contour changes of the side of the vertical plate 3 and has a certain upward elastic reset ability, a first elastic reset member 55 is provided between the upper movable plate 54 and the fixed plate 53. The first elastic reset member 55 (such as a compression spring or a rubber pad) elastically presses the upper movable plate 54 upward.

[0041] The hot pressing device 6 is not directly fixed to the fixed plate 53, but is instead mounted on a lower movable plate 56 below the fixed plate 53. This lower movable plate 56 is fixedly connected to the upper movable plate 54, so it rises and falls synchronously with the rise and fall of the upper movable plate 54. The entire hot pressing device 6, including its key component, the hot pressing plate 61, is mounted on the lower movable plate 56.

[0042] The hot pressing device 6 itself includes a hot pressing plate 61 that is movably connected to the lower movable plate 56 and can be raised and lowered, and a heating element (not shown, such as an electric heating tube or heating wire) disposed within the hot pressing plate 61 for generating heat. In order to apply stable and adjustable sealing pressure to the workpiece when the hot pressing plate 61 is pressed downward, a second elastic return member 62 (such as a compression spring) is provided between the hot pressing plate 61 and the lower movable plate 56 for elastically pressing the hot pressing plate 61 downward. When the upper movable plate 54 descends (thereby driving the lower movable plate 56 and the hot pressing plate 61 to descend as a whole) until the hot pressing plate 61 contacts the workpiece on the main conveyor belt 2, the second elastic return member 62 is further compressed, thereby generating elastic downward pressure on the hot pressing plate 61, i.e., heat sealing pressure.

[0043] In order to further reduce friction when the upper movable plate 54 abuts the side of the upright plate 3, thereby improving movement smoothness and reducing wear, preferably, a plurality of rollers 541 are rotatably connected to the upper surface of the upper movable plate 54 and abut against the side of the upright plate 3. These rollers 541 can roll when the upper movable plate 54 slides along the side of the upright plate 3, thereby achieving low-friction contact.

[0044] The side shape of the vertical plate 3 is the key to controlling the lifting of the hot press plate. The side includes the lower side 31, the left semicircular side 32, the upper side 33 and the right semicircular side 34 connected in sequence. Its shape directly determines the vertical position of the upper movable plate 54 abutting against it. The lower side 31 of the vertical plate 3 corresponds to the side of the lower straight section 41 of the annular track 4. Its design features are as follows: Figure 4As shown, the vertical distance D from the lower side surface 31 to the center O of the right semicircular side surface 34 (or other semicircular side surface) is greater than the radius R of the right semicircular side surface 34. This means that when the lower movable plate 54 abuts the lower side surface 31, the upper movable plate 54 is in a lower vertical position relative to the center O. On the contrary, in the areas of the left semicircular side surface 32, the upper side surface 33, and the right semicircular side surface 34, preferably, the vertical distances of these side profiles to the center O are equal to the radius R (for a straight line segment) or are the radius R (for an arc segment), so that the upper movable plate 54 is in a higher vertical position relative to the center O. Such a geometric design cleverly realizes the automatic control of the hot press plate.

[0045] To ensure reliable power transmission during movement, the conductive structure 8 includes carbon brushes 81 mounted on each slider assembly 5 and conductive strips 82 located on specific areas of the vertical plate 3. Conductive strips 82, serving as power rails, preferably include parallel cathode wires 821 and anode wires 822. These strips are electrically connected to an external power supply. The carbon brushes 81 are electrically connected to the hot press 6 (specifically, the heating element), and the free ends of the carbon brushes 81 are designed to elastically abut against the conductive strips 82, ensuring consistent electrical contact during slider assembly movement.

[0046] To precisely control the heating timing of the hot pressing device 6, the conductive sheet 82 preferably includes a hot pressing segment 8a disposed parallel to the lower straight segment 41 of the annular track 4. This means that only when the slider assembly 5 moves to the lower straight segment 41 will the carbon brush 81 thereon contact the conductive sheet of the hot pressing segment 8a, thereby supplying power to the hot pressing device 6 for heating and sealing.

[0047] Furthermore, to improve heat-sealing efficiency, the hot press platen can be preheated before hot pressing. Therefore, the conductive sheet 82 can also include a preheating section 8b arranged parallel to the right semicircular section 44 of the annular track 4. When the slider assembly 5 moves to the right semicircular section 44, the carbon brush 81 on it contacts the conductive sheet of the preheating section 8b, and the hot pressing device 6 begins to energize and preheat. By the time the slider assembly 5 moves to the lower straight section 41, the hot press platen has reached or is close to the set temperature, allowing for immediate and effective sealing. This shortens the effective sealing time in the lower straight section 41 and ensures sealing quality.

[0048] The main drive unit 7 is the power source for the circular motion of the slider assembly. It includes a driving wheel 71 and a drive wheel 72 rotatably connected to the left and right ends of the vertical plate 3. The driving wheel 71 is driven by a drive motor 73. Connected between the driving wheel 71 and the drive wheel 72 is an endless transmission member, which can be a chain 74 or a belt. Each slider assembly 5 is connected to the chain 74 or belt at intervals. The drive motor 73 drives the chain 74 or belt in a circular motion, thereby driving the slider assembly 5 connected thereto to move synchronously and continuously along the circular track 4.

[0049] The operating process of the present invention is generally as follows: The main conveyor belt 2 continuously or intermittently transports the workpiece to be hot-pressed. Simultaneously, the drive motor 73 drives the chain 74 (or belt), driving all slider assemblies 5 in a continuous, circular motion along the circular track 4. During equipment installation or adjustment, the operator can rotate the adjustment handwheel 92 to drive the vertical plate 3 and the entire circular track 4 to translate laterally on the crossbeam 9, precisely aligning the sealing position of the hot press plate 61 with the workpiece's predetermined sealing line. After position adjustment, the hot press plate 61 is locked and secured. During normal operation, when a slider assembly 5 enters the lower straight section 41 from the right semicircular segment 44, if a preheating section 8b is provided, the hot press plate 61 has already been preheated. Upon entering the lower straight section 41, the lower profile of the vertical plate 3's lower side 31 causes the upper movable plate 54 to descend, driving the hot press plate 61 into contact with the workpiece. Simultaneously, the carbon brushes 81 contact the conductive pads of the hot press section 8a, providing continuous power to the hot press device 6, heating and applying pressure to the workpiece (pressure is provided by the second elastic return member 62). The slider assembly 5 and the workpiece on the main conveyor belt 2 move forward at the same speed in the lower straight section 41 area to complete the heat sealing. When the slider assembly 5 enters the left semicircular section 42 area from the lower straight section 41, the side profile of the vertical plate 3 (the left semicircular side 32) gradually rises, pushing the upper movable plate 54 upward, driving the hot press plate 61 to separate from the workpiece. In the left semicircular section 42 and the upper straight section 43 area, the hot press plate 61 remains raised and does not contact the workpiece. Then, the slider assembly 5 moves to the right semicircular section 44, and the cycle repeats. Since there are multiple slider assemblies 5 connected to the drive chain at intervals, each slider assembly enters the lower straight section in turn to start a new heat sealing process, thereby realizing continuous heat sealing of continuously fed workpieces.

[0050] Compared to existing technologies, this invention eliminates the need for a separate reciprocating lifting, pressing, and returning mechanism for each heat press head. Instead, the lifting and pressing actions are integrated into the mechanical interaction between the slider assembly and the side profile of the fixed track. Through the continuous movement of multiple heat press heads on the circular track, the overall heat sealing process is continuous and efficient, significantly improving production efficiency while reducing equipment complexity and maintenance costs. Furthermore, a convenient and reliable lateral adjustment device is added, enhancing the equipment's adaptability and accuracy to different workpieces.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention should be included in the scope of protection of the present invention. For example, in addition to the manual ball screw pair, the lateral adjustment device can also adopt other mechanisms that can achieve lateral translation and positioning, such as a motor-driven ball screw pair, a hydraulic / pneumatic cylinder with a guide rail, etc.; the specific shape of the annular track and the side of the vertical plate can be adjusted according to actual needs; the conductive structure can also adopt other forms of contact or non-contact power supply; the drive device can also be in the form of a gear rack or a linear motor, etc., as long as the annular continuous motion of the slider assembly and the periodic operation of the hot pressing device can be achieved.

Claims

1. A ring-type continuous heat sealing device, characterized in that: The invention comprises a frame (1), wherein the frame (1) is provided with a main conveyor belt (2) for conveying workpieces to be hot-pressed, and a conveying drive device (21) for driving the main conveyor belt (2); a vertical plate (3) is provided above the main conveyor belt (2); a circular track (4) is provided around the vertical plate (3); the circular track (4) comprises a lower straight segment (41), a left semicircular segment (42), an upper straight segment (43), and a right semicircular segment (44) connected in sequence; a plurality of slider assemblies (5) are slidably connected to the circular track (4); the slider assemblies (5) are provided with a hot pressing device (6) capable of hot pressing the workpieces on the main conveyor belt (2) when the slider assemblies run to the lower straight segment (41); a main driving device (7) for driving the slider assemblies to slide along the circular track (4) is provided between the slider assemblies (5) and the vertical plate (3); and a conductive structure (8) for supplying power to the hot pressing device (6) is also provided between the slider assemblies (5) and the circular track (4).

2. The ring-type continuous heat sealing device according to claim 1, characterized in that: The slider assembly (5) includes a bracket (51), a roller group (52) that cooperates with the annular track (4) is rotatably connected to the bracket (51), a fixed plate (53) is fixedly connected to the bracket (51), and an upper movable plate (54) that can be lifted and lowered is movably connected above the fixed plate (53), the upper surface of the upper movable plate (54) is in contact with the side of the vertical plate (3), and a first elastic reset member (55) that elastically presses the upper movable plate (54) upward is provided between the upper movable plate (54) and the fixed plate (53), the upper movable plate (54) is fixedly connected to a lower movable plate (56) located below the fixed plate (53), and the hot pressing device (6) is provided on the lower movable plate (56).

3. The ring-type continuous heat sealing device according to claim 2, characterized in that: The hot pressing device (6) includes a hot pressing plate (61) movably connected to the lower movable plate (56) and capable of being raised and lowered, and a heating element arranged in the hot pressing plate (61). A second elastic reset member (62) for elastically pressing the hot pressing plate (61) downward is provided between the hot pressing plate (61) and the lower movable plate (56).

4. The ring-type continuous heat sealing device according to claim 2, characterized in that: The upper surface of the upper movable plate (54) is rotatably connected to a plurality of rollers (541) that abut against the side surfaces of the vertical plate (3).

5. The ring-type continuous heat sealing device according to claim 2, characterized in that: The side surfaces of the vertical plate (3) include a lower side surface (31), a left semicircular side surface (32), an upper side surface (33) and a right semicircular side surface (34) connected in sequence, and a vertical distance D from the lower side surface (31) of the vertical plate (3) to the center O of the right semicircular side surface (34) is greater than the radius R of the right semicircular side surface (34).

6. The ring-type continuous heat sealing device according to claim 1, characterized in that: The conductive structure (8) includes a carbon brush (81) provided on each slider, and a conductive sheet (82) provided on the vertical plate (3), wherein the conductive sheet (82) includes a parallel cathode line (821) and an anode line (822), and the conductive sheet (82) is electrically connected to a power supply. The carbon brush (81) is electrically connected to the hot pressing device (6), and the free end of the carbon brush (81) can elastically abut against the conductive sheet (82).

7. The ring-type continuous heat sealing device according to claim 6, characterized in that: The conductive sheet (82) includes a hot pressing section (8a) arranged parallel to the lower straight section (41).

8. The ring-type continuous heat sealing device according to claim 7, characterized in that: The conductive sheet (82) further includes a preheating section (8b) arranged parallel to the right semicircular section (44).

9. The ring-type continuous heat sealing device according to claim 1, characterized in that: The main driving device (7) comprises a driving wheel (71) and a driving wheel (72) rotatably connected to the left and right ends of the vertical plate (3), a driving motor (73) for driving the driving wheel (71) to rotate, and a chain (74) or a belt connected between the driving wheel (71) and the driving wheel (72), and each of the slider assemblies (5) is connected to the chain (74) or the belt at intervals.

10. The ring-type continuous heat sealing device according to claim 1, characterized in that: The frame (1) is also provided with a crossbeam (9), the vertical plate (3) is slidably connected to the crossbeam (9) along the transverse direction of the main conveyor belt (2), and the vertical plate (3) is provided with a transverse adjustment device for driving its transverse translation.

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