A thermoforming device for composite plastic sheets

Abstract

The present application discloses a thermoforming device for composite plastic sheets, and relates to the technical field of thermoforming devices, which includes a frame, a clamping frame, a processing frame and a supporting frame, wherein a thermoforming mold and a vacuum mechanism are arranged on the frame; the clamping frame, the processing frame and the supporting frame are all slidably arranged on the frame, and a plastic sheet that can fit with the mold opening of the thermoforming mold is arranged on the clamping frame; a pretreatment mechanism for processing the plastic sheet into a prototype that matches the thermoforming mold is arranged on the processing frame; a supporting assembly that cooperates with the pretreatment mechanism is arranged on the supporting frame, and can make the outer wall of the prototype correspond to the inner wall of the thermoforming mold, and make the distance between the outer wall of the prototype and the corresponding points on the inner wall of the thermoforming mold keep synchronous and uniform changes and finally keep the same, and the vacuum mechanism is configured to absorb the air between the prototype and the thermoforming mold. The thermoforming device provided by the present application can make the thickness of the plastic sheet more uniform after forming.

Description

Technical Field

[0001] The invention relates to the technical field of thermoforming devices, and in particular to a thermoforming device for composite plastic sheets. Background Art

[0002] Thermoforming of plastic sheets refers to a special plastic processing method that processes thermoplastic plastic sheets into various products. The sheet is clamped on a frame and heated to a softened state. Under the action of external force, it is pressed against the mold surface to obtain a shape similar to the mold surface. After cooling and shaping, it is trimmed to form a product.

[0003] Referring to the Chinese invention patent with publication number "CN112677456B" and patent name "A method for forming a plastic packaging box and a blister mold", a method for forming a plastic packaging box and a blister mold are introduced. The blister molding method mainly includes material taking, softening, feeding, vacuuming, cooling and shaping, demolding and cutting and shaping. In the softening process, the material is mainly heated in three levels to make the material soften more evenly. However, in the process of vacuuming the blister, the softened material is still spread on the mold, and then the gap between the mold and the material is extracted. Air creates a negative pressure state in the mold, and then the external atmospheric pressure squeezes the softened material to make the material fit the inner wall of the mold. After the material cools, the material can form a product that fits the mold. The vacuuming and cooling and shaping process has no special improvement over the traditional method. The material that contacts the mold first is still thicker, and the material that contacts the mold later is still thinner. In addition, since the softened material sticks to the mold mouth, the position where the material first contacts the inner wall of the mold is uncertain when the atmospheric pressure squeezes the material, which leads to uneven thickness of the molded product. Products with uneven thickness are more vulnerable to damage. Summary of the invention

[0004] The invention provides a thermoforming device for composite plastic sheets to solve the problem of uneven thickness of existing plastic sheets after thermoforming.

[0005] A thermoforming device for a composite plastic sheet of the present invention adopts the following technical solution:

[0006] A thermoforming device for composite plastic sheets, comprising a frame, a clamping frame, a processing frame and a supporting frame, wherein the frame is provided with a thermoforming mold and a vacuum pumping mechanism; the clamping frame is slidably arranged on the frame and is located above the thermoforming mold, and the clamping frame is provided with a plastic sheet that can fit with the mold opening of the thermoforming mold; the processing frame is slidably arranged on the frame and is located above the clamping frame, and the processing frame is provided with a pre-processing mechanism, and the pre-processing mechanism includes a positioning plate and a pressing mechanism, and the positioning plate is arranged on the processing frame, and the positioning plate A track hole is opened on the top, the pressing mechanism is movably arranged on the positioning plate, the pressing mechanism is provided with multiple groups, and the multiple groups of pressing mechanisms correspond to the multiple inner side walls of the thermoforming mold respectively, the pressing mechanism comprises a moving shaft, a telescopic shell and a rolling support assembly, the moving shaft is passed through the track hole and can be moved along the track hole by an external control mechanism, the telescopic shell is arranged at the bottom end of the moving shaft, the length directions of the multiple telescopic shells are respectively parallel to the multiple edges of the inner bottom surface of the thermoforming mold, a stretching mechanism is arranged between the moving shaft and the telescopic shell, The stretching mechanism is used to control the expansion and contraction of the telescopic shell, and the pretreatment mechanism is used to press down the plastic sheet to form a prototype compatible with the thermoforming mold; the supporting frame is slidably arranged on the frame and is located below the clamping frame, and a supporting assembly is provided on the supporting frame, and the supporting assembly is provided with multiple groups, and the multiple groups of the supporting assemblies correspond to the multiple groups of the pressing mechanisms respectively, and the supporting assembly includes a supporting rod and a supporting shaft, the supporting rod is rotatably arranged at both ends of the supporting shaft, and the supporting rod is movably arranged on the supporting frame, and the supporting shaft is connected to the corresponding telescopic The shell is parallel in length direction and can hold up the plastic sheet. The moving speed of the supporting shaft is adapted to the moving speed of the corresponding telescopic shell so that the prototype maintains synchronous expansion in the thermoforming mold. The supporting assembly cooperates with the pretreatment mechanism so that the outer wall of the prototype corresponds to the inner wall of the thermoforming mold, and the distance between the outer wall of the prototype and the corresponding points on the inner wall of the thermoforming mold keeps changing synchronously and evenly and finally remains consistent. The vacuum mechanism is configured to absorb air between the prototype and the thermoforming mold.

[0007] Further, the rolling support assembly is arranged in the telescopic shell, and the rolling support assembly includes a support wheel, a telescopic rod and a reel, the support wheel includes a first support wheel and a second support wheel, the first support wheel and the second support wheel are both fixed in the telescopic shell and are respectively close to the two ends of the telescopic shell, the telescopic rod is parallel to the length direction of the telescopic shell, and the telescopic rod is connected between the first support wheel and the second support wheel, the telescopic rod is provided with a mounting strip, the reel includes a first reel and a second reel, the first reel and the second reel are respectively rotatably arranged at the two ends of the mounting strip, a transmission belt is wound around the first reel, the transmission belt sequentially passes around the first support wheel and the second support wheel and is finally wound around the second reel, and the lower section of the transmission belt extends out of the bottom surface of the telescopic shell and can be pressed on the plastic sheet.

[0008] Furthermore, a coil spring is arranged on the reel, and the coil spring can enable the reel to reel in the transmission belt, so that the transmission belt always remains in a tightened state.

[0009] Further, the movable shaft is a threaded shaft, which is rotatably connected to the telescopic shell, and the stretching mechanism includes a rotating motor, a rotating sleeve, a hinged rod and a limit rod. The rotating motor is movably arranged on the positioning plate, and the threaded shaft is fixedly connected to the output shaft of the rotating motor. The rotating sleeve is threadedly connected to the threaded shaft. Two hinged rods are provided, and the two hinged rods are hinged to the rotating sleeve and symmetrically arranged about the central axis of the rotating sleeve. One end of the hinged rod away from the rotating sleeve is hinged to the telescopic shell, and the limit rod is fixed to the rotating motor, and the limit rod is arranged parallel to the threaded shaft. A limit ring is provided on the rotating sleeve, and the limit rod is inserted into the limit ring.

[0010] Furthermore, a flattening mechanism is provided in the telescopic shell, and the flattening mechanism includes a rotating drum, a friction telescopic shaft and a driving assembly. The rotating drum is rotatably arranged on the transmission belt, and the rotating drum located on the lower section of the transmission belt protrudes from the bottom surface of the telescopic shell. The friction telescopic shaft is rotatably arranged between the first support wheel and the second support wheel, and the length direction of the friction telescopic shaft is parallel to the length direction of the lower section of the transmission belt. The driving assembly is arranged on the telescopic rod, and the driving assembly is used to drive the friction telescopic shaft to reciprocate in its axial direction. The friction telescopic shaft conflicts with the rotating drum located on the lower section of the transmission belt, and the rotation of the friction telescopic shaft is enough to drive the corresponding rotating drum to rotate synchronously. The reciprocating rotation of the rotating drum can flatten the plastic sheet, so that the thickness of the plastic sheet at the rotating drum is uniform.

[0011] Furthermore, the driving assembly includes a driving motor, a linkage plate and a limit plate, the driving motor is arranged on the telescopic rod, the linkage plate is slidably arranged on the mounting bar, and the sliding direction of the linkage plate is perpendicular to the length direction of the mounting bar, an eccentric shaft is arranged on the output shaft on the driving motor, a through groove parallel to the length direction of the mounting bar is opened on the linkage plate, the eccentric shaft is inserted into the through groove, the width of the through groove is smaller than the rotation diameter of the eccentric shaft, the limit plate is arranged on the telescopic rod and slidably connected to the linkage plate, and the side of the linkage plate away from the limit plate conflicts with the friction telescopic shaft.

[0012] Furthermore, a driving plate is provided at the bottom of the linkage plate, and the driving plate is slidably arranged between the linkage plate and the limit plate through a sliding component, and the sliding component includes a first inclined surface and a second inclined surface, the first inclined surface is an end surface of the limit plate away from the telescopic rod, and the second inclined surface is an end surface of the linkage plate close to the lower section of the transmission belt, the first inclined surface and the second inclined surface are arranged at an angle, the driving plate is arranged in an angle area surrounded by the first inclined surface and the second inclined surface, the driving plate is slidably arranged on the first inclined surface, and a side of the driving plate facing the second inclined surface is slidably connected to the second inclined surface;

[0013] During the process of the linkage plate moving toward the direction approaching the lower section of the transmission belt, the drive plate is always slidingly connected with the first inclined surface and the second inclined surface, and the side of the drive plate facing away from the first inclined surface is always in contact with the friction telescopic shaft. When the drive plate moves on the first inclined surface, it can always drive the friction telescopic shaft to rotate.

[0014] Furthermore, a first auxiliary rod and a second auxiliary rod are arranged on the telescopic rod, the first auxiliary rod is slidably connected to the second auxiliary rod, and both the first auxiliary rod and the second auxiliary rod are in conflict with the rotating drum on the lower section of the transmission belt.

[0015] Furthermore, the friction force between the rotating drum and the first auxiliary rod and the second auxiliary rod is smaller than the friction force between the friction telescopic shaft and the rotating drum and the driving plate.

[0016] The beneficial effects of the present invention are: when the processing frame of the present invention moves toward the plastic sheet on the clamping frame, the pretreatment mechanism can press down the plastic sheet and form a prototype that is compatible with the thermoforming mold, and the supporting assembly on the supporting frame can cooperate with the pretreatment mechanism to make each point on the outer wall of the prototype correspond to each point on the inner wall of the thermoforming mold, and can make the distance between the corresponding points change synchronously and evenly, and finally reach consistency. Since the distance between the prototype and each point in the thermoforming mold changes synchronously and evenly, the elongation distance of each side wall of the plastic sheet changes evenly when it is pressed down, and the thickness also changes evenly.

[0017] When the distance between the plastic sheet and the thermoforming mold after the pretreatment mechanism and the supporting assembly reaches the appropriate distance, that is, when they reach consistency, the vacuum mechanism is started to draw the inner cavity of the thermoforming mold into a negative pressure state, so that the outer atmospheric pressure can press the side walls of the prototype formed by the plastic sheet, and press the side walls of the prototype against the corresponding inner wall of the thermoforming mold, thereby completing the molding of the plastic sheet. Before vacuuming, since the distance between the outer wall of the prototype and the inner wall of the thermoforming mold is consistent, during the vacuuming process, the outer wall of the prototype can basically fit on the inner wall of the thermoforming mold at the same time, thereby making the thickness of the formed plastic sheet more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A schematic diagram of the overall structure of a thermoforming device for a composite plastic sheet provided in an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the forward structure of a thermoforming device for a composite plastic sheet provided in an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the structure from a top view of a thermoforming device for a composite plastic sheet provided in an embodiment of the present invention;

[0022] Figure 4 for Figure 3 Schematic diagram of the cross-section structure in the AA direction;

[0023] Figure 5 for Figure 4 A schematic diagram of the enlarged structure of part B;

[0024] Figure 6 for Figure 4 A schematic diagram of the enlarged structure of the middle C part;

[0025] Figure 7 A schematic structural diagram of a rotating motor and a telescopic shell in a thermoforming device for a composite plastic sheet provided by an embodiment of the present invention;

[0026] Figure 8 A schematic diagram of the structure between a telescopic rod and a support wheel in a telescopic shell of a thermoforming device for a composite plastic sheet provided by an embodiment of the present invention;

[0027] Fig. 9 for Figure 8 A schematic diagram of the enlarged structure of the D part;

[0028] Fig.10 A schematic structural diagram of another perspective of a telescopic rod and a support wheel in a telescopic shell of a thermoforming device for a composite plastic sheet provided by an embodiment of the present invention;

[0029] Fig.11 for Fig.10 Schematic diagram of the cross-sectional structure in the EE direction;

[0030] Fig.12 for Fig.11 Schematic diagram of the enlarged structure of part F.

[0031] In the figure: 100, frame; 110, thermoforming mold; 120, vacuum mechanism; 200, clamping frame; 210, plastic sheet; 300, processing frame; 400, supporting frame; 410, supporting assembly; 411, supporting rod; 412, supporting shaft; 510, positioning plate; 520, moving shaft; 530, telescopic shell; 541, supporting wheel; 5411, first supporting wheel; 5412, second supporting wheel; 542, telescopic rod; 543, reel; 5431, first reel; 5432, The second reel; 544, the transmission belt; 601, the mounting plate; 602, the mounting strip; 610, the motor slot; 710, the rotating sleeve; 720, the hinged rod; 730, the limiting rod; 740, the rotating motor; 810, the rotating drum; 820, the friction telescopic shaft; 831, the driving motor; 832, the linkage plate; 8320, the second inclined plane; 8321, the through slot; 833, the driving plate; 834, the limiting plate; 8340, the first inclined plane; 901, the first auxiliary rod; 902, the second auxiliary rod. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the accompanying drawings, which 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 therefore cannot be understood as a limitation to the present invention.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0035] like Figures 1 to 5As shown, a thermoforming device for a composite plastic sheet provided by an embodiment of the present invention comprises a frame 100, a clamping frame 200, a supporting frame 400 and a processing frame 300. A thermoforming mold 110 and a vacuum mechanism 120 are arranged on the frame 100. The vacuum mechanism 120 is arranged below the thermoforming mold 110, and the vacuum mechanism 120 is used to increase the pressure in the thermoforming mold 110 so as to accelerate the forming of the plastic sheet 210. The clamping frame 200, the supporting frame 400 and the processing frame 300 are all slidably arranged on the frame 100, wherein the supporting frame 400 is located below the clamping frame 200, the processing frame 300 is located above the clamping frame 200, and the clamping frame 200 is arranged at the mold opening of the thermoforming mold 110. A plastic sheet 210 is arranged on the clamping frame 200, and the plastic sheet 210 can cover the mold opening of the thermoforming mold 110. A supporting component 410 capable of holding up the plastic sheet 210 is arranged on the supporting frame 400. A pretreatment mechanism is provided on the processing frame 300, and the pretreatment mechanism can press down the plastic sheet 210 to form a prototype that is compatible with the thermoforming mold 110. The supporting component 410 cooperates with the pretreatment mechanism to make the outer wall of the prototype correspond to the inner wall of the thermoforming mold 110, and the distance between the outer wall of the prototype and the corresponding points on the inner wall of the thermoforming mold 110 keeps synchronous and uniform changes and finally remains consistent, and the vacuum mechanism 120 is configured to absorb the air between the prototype and the thermoforming mold 110.

[0036] Specifically, the frame 100 is a metal frame with a multi-layer structure set on the ground. A plurality of vertical sliding rods can be set on the frame 100. The clamping frame 200, the supporting frame 400 and the processing frame 300 are all slidably set on the sliding rods. The frame 100 is provided with a cylinder and a push rod and other mechanisms that can push the clamping frame 200, the supporting frame 400 and the processing frame 300 to slide on the sliding rods. A heating device such as a hot air blower that can heat the plastic sheet 210 to be processed is also provided. The thermoforming mold 110 is set at a relatively lower position of the frame 100. The thermoforming mold 110 can be a thermoforming mold 110 in an existing vacuum forming machine. The vacuum mechanism 120 is set below the thermoforming mold 110, and is used to suck the plastic sheet 210 heated by the thermoforming mold 110 into the mold so that the plastic sheet 210 can be quickly formed. The clamping frame 200 slidably set on the sliding rod of the frame 100 can be composed of two annular rectangular frames. The plastic sheet 210 can be clamped in the middle by the two annular rectangular frames and can be attached above the mold opening of the thermoforming mold 110. At the same time, the plastic sheet 210 can be heated by heating equipment such as a hot air blower and an electric heating wire installed on the frame 100, which facilitates the subsequent molding of the plastic sheet 210 in the thermoforming mold 110.

[0037] The supporting frame 400 may be a rectangular frame corresponding to the clamping frame 200. The supporting frame 400 is also slidably disposed on the sliding rod of the frame 100 and is located below the clamping frame 200. The supporting frame 400 is provided with a supporting assembly 410 capable of supporting the plastic sheet 210. The processing frame 300 is slidably disposed on the sliding rod of the frame 100 and is located above the plastic sheet 210. The processing frame 300 is provided with a pre-treatment mechanism capable of pressing down the plastic sheet 210. The pre-treatment mechanism can press the plastic sheet 210 into a prototype. The prototype is an unfinished workpiece that is compatible with the inner liner of the thermoforming mold 110. The essence is still the plastic sheet 210, but it is formed into a shape that is compatible with the thermoforming mold 110. The prototype still needs to be processed by the vacuum mechanism 120 in the thermoforming mold 110 and cooled before it can form a complete workpiece. The supporting assembly 410 cooperates with the pretreatment mechanism to make the outer wall of the prototype correspond to the inner wall of the thermoforming mold 110, and to make the distance between the outer wall of the prototype and the corresponding points on the inner wall of the thermoforming mold 110 keep changing synchronously and evenly, and finally keep the same. The distance between the outer wall of the prototype and the corresponding points on the inner wall of the thermoforming mold 110 can be set to a preset value. When the pretreatment mechanism and the supporting assembly 410 expand the prototype, the distance between the outer wall of the prototype and the corresponding points on the inner wall of the thermoforming mold 110 can reach the preset value. After that, the preforming mechanism stops pressing or stretching the plastic sheet 210, and the supporting assembly 410 fits the plastic sheet 210 with the mold opening of the thermoforming mold 110. At this time, the space between the prototype and the thermoforming mold 110 is vacuumed, and the side wall of the prototype can fit with the inner wall of the thermoforming mold 110 at the same time after a period of time.

[0038] Since the distance between each point on the prototype and the inner wall of the thermoforming mold 110 changes synchronously and evenly, the thickness of the prototype changes evenly as the prototype gradually increases. Also, because the distance between each point on the prototype and the corresponding points on the inner wall of the thermoforming mold 110 reaches a preset value and they are simultaneously attached to the inner wall of the thermoforming mold 110, the thickness of the complete workpiece finally formed in the thermoforming mold 110 is also relatively uniform.

[0039] In the present invention, the pretreatment mechanism arranged on the processing frame 300 includes a positioning plate 510 and a pressing mechanism. The positioning plate 510 is arranged on the processing frame 300. A track hole is opened on the positioning plate 510. The pressing mechanism is movably arranged on the positioning plate 510. Multiple groups of pressing mechanisms can be arranged, and the multiple groups of pressing mechanisms correspond to multiple inner walls of the thermoforming mold 110 respectively.

[0040] In this embodiment, the processing frame 300 may be a rectangular frame-like structural member, and the positioning plate 510 is fixed on the processing frame 300 and covers the frame opening of the processing frame 300. The positioning plate 510 is arranged on the processing frame 300 and faces the inside of the thermoforming mold 110. The track hole may be a cross hole, and each end of the cross hole corresponds to the inner side wall of the thermoforming mold 110 on one side. The pressing mechanism may be provided with four groups, and the four groups of pressing mechanisms correspond to the four inner side walls of the thermoforming mold 110 respectively.

[0041] like Figures 3 to 7 As shown, the pressing mechanism includes a movable shaft 520, a telescopic shell 530 and a rolling support assembly. The movable shaft 520 is inserted into the track hole and can move along the track hole through an external control mechanism. The telescopic shell 530 is installed at the bottom end of the movable shaft 520. A stretching mechanism is provided between the movable shaft 520 and the telescopic shell 530, and the stretching mechanism is used to control the extension and retraction of the telescopic shell 530.

[0042] In this embodiment, four moving shafts 520 are provided, corresponding to four groups of pressing mechanisms respectively, and the moving shafts 520 are all inserted into the cross hole, and each moving shaft 520 corresponds to four ends of the cross hole respectively, and the cross hole includes four strip holes, and the four strip holes are arranged in a cross shape on the positioning plate 510. The four moving shafts 520 can be inserted into the corresponding strip holes, and the moving shafts 520 can slide along the corresponding strip holes through an external control mechanism.

[0043] The movable shaft 520 can be a long straight steel shaft, and the telescopic shell 530 can be a shell with a telescopic function, which can include an intermediate shell with a rectangular or circular cross-section and two side shells compatible with the intermediate shell, the two side shells are respectively slidably connected to the two sides of the intermediate shell, and a guide groove body such as a slide groove can be provided on the outer wall of the intermediate shell, and a guide rail or the like compatible with the guide groove body such as the slide groove can be provided on the inner wall of the side shell. The two side shells are respectively mounted on the intermediate shell from the two ends of the intermediate shell, and the movable shaft 520 is rotatably connected to the middle position of the intermediate shell of the telescopic shell 530. The stretching mechanism is arranged between the telescopic shell 530 and the movable shaft 520. The stretching mechanism can be an electric push rod and a telescopic cylinder arranged on the telescopic shell 530, and its two ends can be respectively fixed on the two side shells of the telescopic shell 530, and the telescopic movement of the telescopic shell 530 can be controlled by the stretching mechanism.

[0044] The telescopic shell 530 is installed at one end of the moving shaft 520 passing through the track hole, and the multiple telescopic shells 530 respectively correspond to the multiple bottom edge edges of the thermoforming mold 110. In this embodiment, four moving shafts 520 correspond to four telescopic shells 530, and the four telescopic shells 530 respectively correspond to the four edges of the inner bottom surface of the thermoforming mold 110. When the moving shaft 520 is moved by the external control mechanism, the telescopic shell 530 moves accordingly, and when the processing frame 300 approaches the plastic sheet 210, the telescopic shell 530 is pressed toward the plastic sheet 210 accordingly.

[0045] See also Figures 7 to 10 Combined with Figure 4 As shown, the rolling support assembly is arranged in the telescopic shell 530, and the rolling support assembly includes a support wheel 541, a telescopic rod 542 and a reel 543. The support wheel 541 includes a first support wheel 5411 and a second support wheel 5412, and the first support wheel 5411 and the second support wheel 5412 are both fixedly connected in the telescopic shell 530 and are respectively close to the two ends of the telescopic shell 530. The telescopic rod 542 is parallel to the length direction of the telescopic shell 530, and the two ends of the telescopic rod 542 are respectively fixedly connected to the first support wheel 5411 and the second support wheel 5412. The telescopic rod 542 is provided with a mounting strip 602 parallel to the axial direction of the telescopic rod 542. The reel 543 is rotatably set on the mounting strip 602, and the reel 543 includes a first reel 5431 and a second reel 5432. The first reel 5431 and the second reel 5432 are respectively close to the two ends of the mounting strip 602, the first reel 5431 corresponds to the first support wheel 5411, and the second reel 5432 corresponds to the second support wheel 5412. A transmission belt 544 is wound around the first reel 5431, and the transmission belt 544 passes around the first support wheel 5411 and the second support wheel 5412 in sequence and is finally wound around the second reel 5432, and the lower section of the transmission belt 544 extends out of the bottom surface of the telescopic shell 530. When the processing frame 300 moves toward the plastic sheet 210, the transmission belt 544 can move with the processing frame 300 and first contact the plastic sheet 210, and continue to move the processing frame 300 toward the plastic sheet 210, so that the transmission belt 544 can continue to press down the plastic sheet 210, thereby forming a prototype that is compatible with the thermoforming mold 110.

[0046] Specifically, the support wheel 541 is a wheel body with an arc surface, but due to the telescopic rod 542, the support wheel 541 cannot rotate in the telescopic shell 530 and is only used to support the transmission belt 544. The telescopic rod 542 may include an intermediate tube and an inner rod, and two inner rods are provided. The two inner rods are respectively inserted into the intermediate tube from the two end tube openings of the intermediate tube, and the two inner rods are symmetrically arranged on the intermediate tube about the center of the intermediate tube. The inner rods on both sides of the intermediate tube can move along the length direction of the intermediate tube. A mounting plate 601 is provided, and two mounting plates 601 can be provided on the mounting plate 601. The two mounting plates 601 can be fixed on the telescopic rod 542 by bonding, welding, riveting, etc., and the two mounting plates 601 are symmetrically arranged about the cross section at the center of the intermediate tube. The mounting bar 602 can be a plate parallel to the length direction of the telescopic rod 542, and the mounting bar 602 is fixed on the two mounting plates 601 and is located above the telescopic rod 542. The first reel 5431 and the second reel 5432 are rotatably arranged at the two ends of the mounting strip 602, respectively. The first reel 5431 and the second reel 5432 are both rotatable wheels, and their wheel surfaces can be arc surfaces. The transmission belt 544 can be a steel wire rope or a high temperature resistant metal wire with a circular cross section. The transmission belt 544 can move on the frame 100 with the processing frame 300. When it is wound around the first support wheel 5411, the second support wheel 5412, the first reel 5431 and the second reel 5432, its lower section can protrude from the bottom surface of the telescopic shell 530, and then can first contact with the plastic sheet 210, and then can realize the pressing of the plastic sheet 210 by the transmission belt 544, and then can make the plastic sheet 210 form a prototype, and in the process of forming the prototype, since the pressure of each point on the transmission belt 544 on the plastic sheet 210 is consistent, the thickness of the formed prototype can be made more uniform by the downward pressure of the four transmission belts 544.

[0047] The reel 543 is provided with a coil spring, which enables the reel 543 to reel the transmission belt 544, so that the transmission belt 544 is always in a tightened state. The tightened transmission belt 544 exerts a more stable force on the plastic sheet 210 when pressing down the plastic sheet 210, which is conducive to maintaining a uniform thickness of the plastic sheet 210 during initial molding.

[0048] like Figures 4 to 6 As shown, a plurality of supporting components 410 are provided, and the plurality of supporting components 410 respectively correspond to the plurality of telescopic shells 530, i.e., the plurality of pressing mechanisms. The supporting components 410 include a support rod 411 and a support shaft 412. The support rod 411 is rotatably arranged at both ends of the support shaft 412. The support rod 411 is movably arranged on the supporting frame 400. The support shaft 412 is parallel to the length direction of the corresponding telescopic shell 530 and can support the plastic sheet 210.

[0049] Specifically, the support rod 411 may be a zigzag rod, the support shaft 412 may be a cylindrical shaft, and the support rod 411 may be moved on the frame surface of the support frame 400 by a driving member such as a cylinder or a push rod. There are multiple groups of support components 410, and the multiple groups of support components 410 correspond to multiple telescopic shells 530 respectively, and the support shaft 412 is parallel to the length direction of the corresponding telescopic shell 530. In this embodiment, there may be four support shafts 412, and the four support shafts 412 are respectively arranged above the four side edges of the opening of the thermoforming mold 110. The moving speed of the support shaft 412 is adapted to the moving speed of the corresponding telescopic shell 530. When the moving shaft 520 in the pretreatment mechanism drives the telescopic shell 530 to move along the cross hole, the support shaft 412 will also move accordingly. When the pretreatment mechanism expands the prototype until the distance between the outer wall of the prototype and the inner wall of the thermoforming mold 110 reaches a preset value, and the distance between the bottom surface of the prototype and the inner bottom surface of the thermoforming mold 110 reaches the preset value plus the diameter of the support shaft 412, the support shaft 412 is removed so that the plastic sheet 210 can be completely fitted with the edge of the opening of the thermoforming mold 110, and then the air between the prototype and the thermoforming mold 110 is sucked through the vacuum mechanism 120 to complete the forming of the plastic sheet 210 in the thermoforming mold 110.

[0050] It should be noted that before removing the support shaft 412, it should be ensured that the distance between the outer wall of the prototype and the inner wall of the thermoforming mold 110 reaches the preset value, and the distance between the outer bottom surface of the prototype and the inner bottom surface of the thermoforming mold 110 should be the preset value plus the diameter of the support shaft 412. Only in this way, when the support shaft 412 is removed, the distance between the outer bottom surface of the prototype and the inner bottom surface of the thermoforming mold 110 can reach the preset value and the vacuum operation can be performed.

[0051] The operating principle of this embodiment is:

[0052] First, the plastic sheet 210 is clamped on the clamping frame 200, and then the clamping frame 200 is moved to the top of the thermoforming mold 110, the supporting frame 400 is moved to the bottom of the clamping frame 200, and the processing frame 300 is moved to a suitable position above the clamping frame 200, and then the hot air blower or other equipment that can heat the plastic sheet 210 set on the frame 100 is turned on. After the plastic sheet 210 is softened, the processing frame 300 is moved to press the telescopic shell 530 and the transmission belt 544 on the plastic sheet 210, and then the telescopic shell 530 is stretched by the stretching mechanism, and at the same time, the rotating motor 740 is moved in the cross hole by the cylinder or push rod set on the frame 100, and continues to move closer to the plastic sheet 210. The processing frame 300 is moved in the direction of the clamping frame 200, and the movement of the support rod 411 and the support shaft 412 is also controlled. The telescopic shell 530 and the transmission belt 544 arranged on the processing frame 300 will gradually press out a prototype that is compatible with the thermoforming mold 110 on the plastic sheet 210. With the extension of the telescopic shell 530, the downward movement of the processing frame 300, and the movement of the support rod 411 and the support shaft 412, the volume of the prototype is always kept proportionally enlarged, and the distance between the point on the side wall of the prototype and the corresponding point on the inner wall of the thermoforming mold 110 is kept synchronously and evenly changed and can reach a preset value at the same time, that is, a prototype with more uniform thickness can be processed / produced;

[0053] When the distance between the prototype and the thermoforming mold 110 reaches a preset value, wherein the distance between the outer bottom surface of the prototype and the inner bottom surface of the thermoforming mold 110 should reach the preset value plus the diameter of the support shaft 412, the clamping frame 200 and the supporting frame 400 are moved downward to separate the support shaft 412 from the plastic sheet 210, and at the same time, the plastic sheet 210 is made to fit the mold opening of the thermoforming mold 110, and then the vacuum mechanism 120 is started to draw the inner cavity of the thermoforming mold 110 into a negative pressure state, so that the outer atmospheric pressure can press the side walls of the prototype to fit closely to the corresponding inner wall of the thermoforming mold 110, thereby completing the molding of the plastic sheet 210. Relying on the mutual cooperation between the pretreatment mechanism and the supporting assembly 410, the volume of the prototype formed by the plastic sheet 210 is always proportionally enlarged during the molding process, so that the thickness of the prototype is relatively uniform. The outer walls of the prototype are finally attached to the inner wall of the thermoforming mold 110 at the same time, so that the thickness of each position of the formed plastic sheet 210 can be relatively uniform.

[0054] In some embodiments, Figures 3 to 7As shown, the movable shaft 520 is a threaded shaft, and the threaded shaft is rotatably connected to the telescopic shell 530. The stretching mechanism is arranged between the threaded shaft and the telescopic shell 530. The stretching mechanism includes a rotating motor 740, a rotating sleeve 710, a hinged rod 720 and a limit rod 730. The rotating motor 740 is movably arranged on the positioning plate 510, the threaded shaft is fixedly connected to the output shaft of the rotating motor 740, the rotating sleeve 710 is threadedly connected to the threaded shaft, the hinged rod 720 is hinged on the rotating sleeve 710, and two hinged rods 720 are provided, and the two hinged rods 720 are symmetrically arranged about the central axis of the rotating sleeve 710, and the ends of the two hinged rods 720 away from the rotating sleeve 710 are both hinged to the telescopic shell 530, and the hinged positions of the hinged rod 720 and the telescopic shell 530 are symmetrical about the threaded axis. The limit rod 730 is installed on the rotating motor 740, and the limit rod 730 is arranged parallel to the threaded axis. A limiting ring is provided on the rotating sleeve 710 , and the limiting rod 730 is inserted into the limiting ring to limit the rotation of the rotating sleeve 710 .

[0055] The threaded shaft can be rotatably arranged in the middle position of the middle shell of the telescopic shell 530, and the rotating sleeve 710 can be a workpiece similar to a nut, in which a thread is arranged, and the rotating sleeve 710 is threadedly connected to the threaded shaft. The hinged rod 720 can be a metal straight rod, and the hinged rod 720 is hinged on the outer wall of the rotating sleeve 710. The end of the hinged rod 720 away from the rotating sleeve 710 is hinged to the telescopic shell 530, and two hinged rods 720 are provided, and the hinge positions of the two hinged rods 720 on the rotating sleeve 710 are symmetrically arranged about the threaded axis. The two hinged rods 720 correspond to the two side shells of the telescopic shell 530 respectively, and are respectively hinged to the corresponding side shells. The limit rod 730 is installed on a side surface of the rotating motor 740 with an output shaft, and the limit rod 730 is passed through a limit ring on the rotating sleeve 710. The rotating motor 740 can drive the rotating motor 740 to move on the positioning plate 510 through an external driving mechanism. During operation, since the limiting rod 730 limits the rotation of the rotating sleeve 710, the rotating sleeve 710 can be moved on the threaded shaft. The movement of the rotating sleeve 710 can drive the telescopic shell 530 to extend and retract, and then drive the transmission belt 544 to stretch or contract. The stretching of the transmission belt 544 can press down and stretch a larger range of plastic sheets 210 or at different positions of the plastic sheet 210.

[0056] In some embodiments, Figures 7 to 10 Shown and combined Figure 3-Figure 5A flattening mechanism capable of flattening the thickness of the plastic sheet 210 is disposed in the telescopic shell 530 , and the flattening mechanism includes a rotating drum 810 , a friction telescopic shaft 820 and a driving assembly. The rotating drum 810 is rotatably set on the transmission belt 544. The transmission belt 544 located below the support wheel 541, that is, the rotating drum 810 located on the lower section of the transmission belt 544 protrudes from the bottom surface of the telescopic shell 530 and can contact the plastic sheet 210 before the transmission belt 544. Connecting rods are provided on the first support wheel 5411 and the second support wheel 5412. A friction telescopic shaft 820 is rotatably set between the two connecting rods. The length direction of the friction telescopic shaft 820 is parallel to the length direction of the transmission belt 544 located below the support wheel 541. The driving assembly is set between the mounting plate 601 and the telescopic rod 542. The driving assembly is used to drive the friction telescopic shaft 820 to reciprocate. The friction telescopic shaft 820 contacts the rotating drum 810 located on the lower section of the transmission belt 544. The reciprocating rotation of the friction telescopic shaft 820 can drive the corresponding rotating drum 810 to rotate synchronously.

[0057] Specifically, the rotating drum 810 may be a cylindrical metal structure, and a bearing may be coaxially arranged inside the rotating drum 810, and the rotating drum 810 may rotate on the transmission belt 544 by means of the bearing. A plurality of rotating drums 810 may be arranged on the transmission belt 544, and the plurality of rotating drums 810 are evenly distributed along the length direction of the transmission belt 544. Among them, the rotating drum 810 located below the support wheel 541, that is, on a section of the transmission belt 544 below the first support wheel 5411 and the second support wheel 5412, protrudes from the bottom surface of the telescopic shell 530, and in the process of the processing frame 300 moving toward the plastic sheet 210, the rotating drum 810 protruding from the bottom surface of the telescopic shell 530 will contact the plastic sheet 210 before the transmission shaft. The connecting rod may be arranged on the first support wheel 5411 and the second support wheel 5412, and the length direction of the connecting rod may be perpendicular to the length direction of the telescopic rod 542, that is, it may be perpendicular to the length direction of the section of the transmission belt 544 below the first support wheel 5411 and the second support wheel 5412. Two friction telescopic shafts 820 may be provided, and both friction telescopic shafts 820 may be rotatably arranged between two connecting rods through bearings, and the central axis of each of the two friction telescopic shafts 820 may be located on an inclined plane. Both friction telescopic shafts 820 conflict with the rotating drum 810 located below the first support wheel 5411 and the second support wheel 5412. The driving assembly is provided between the mounting plate 601 and the telescopic rod 542, and the driving assembly may drive the two friction telescopic shafts 820 to reciprocate, thereby driving the rotating drum 810 conflicting with the friction telescopic shafts 820 to reciprocate.

[0058] More specifically, the friction telescopic shaft 820 may include an outer cylinder and an inner rod, the outer cylinder wall of the outer cylinder is set as a friction surface, the inner rod is slidably set in the outer cylinder, and the two friction telescopic shafts 820 are set in opposite directions between the two connecting rods, one end of the outer cylinder of one friction telescopic shaft 820 is rotatably connected to one connecting rod, and one end of the outer cylinder of the other friction telescopic shaft 820 is rotatably connected to the other connecting rod, ensuring that when the telescopic shell 530 is telescoped, the two friction telescopic shafts 820 can always be in conflict with the rotating cylinder 810 located below the first support wheel 5411 and the second support wheel 5412, that is, as long as the rotating cylinder 810 is located below the two support wheels 541 (the lower section of the transmission belt 544), it can be in conflict with at least one of the two friction telescopic shafts 820, and as long as the rotating cylinder 810 is located below the two support wheels 541 (the lower section of the transmission belt 544), it can rotate synchronously with the friction telescopic shaft 820.

[0059] The reciprocating drum 810 can stretch and flatten the plastic sheet 210 to prevent the plastic sheet 210 from being too thick at the drum 810. It can be understood that, under normal circumstances, if the transmission belt 544 directly presses against the plastic sheet 210, the pressure of the transmission belt 544 on the plastic sheet 210 will be relatively large. At this time, if the processing frame 300 drives the transmission belt 544 to press down the plastic sheet 210, the part of the plastic sheet 210 that contacts the transmission belt 544 will be difficult to be stretched due to the large pressure (friction) between the transmission belt 544, and the hotter plastic sheet 210 will first contact the transmission belt 544, and will cool faster. , it will be shaped faster and more difficult to stretch, which will cause the portion of the plastic sheet 210 that contacts the transmission belt 544 to be thicker than other positions. However, after the rotating drum 810 is arranged on the transmission belt 544, the rotating drum 810 can reciprocate while pressing down the plastic sheet 210. The reciprocating rotating drum 810 can rely on friction to push the thicker portions of the plastic sheet 210 to both sides, thereby reducing the thickness of the plastic sheet 210 at the rotating drum 810 and making the thickness of the plastic sheet 210 more uniform.

[0060] In this embodiment, if Figures 10 to 12As shown, the driving assembly includes a driving motor 831, a linkage plate 832 and a limit plate 834. The driving motor 831 is mounted on the mounting plate 601, and the mounting plate 601 is fixed on the telescopic rod 542. A sleeve is provided on the output shaft of the driving motor 831, and an eccentric shaft is provided on the sleeve. The eccentric shaft is eccentrically arranged relative to the output shaft of the driving motor 831, that is, the length direction of the eccentric shaft is parallel to the axial direction of the output shaft of the driving motor 831, but deviates from the output shaft of the driving motor 831. A motor slot hole 610 is provided on the mounting bar 602, and the motor slot hole 610 corresponds to the output surface of the drive motor 831. The linkage plate 832 is penetrated in the motor slot hole 610 and is located between the slot bottom of the motor slot hole 610 and the drive motor 831. A through slot 8321 parallel to the length direction of the mounting bar 602 is provided on the side of the linkage plate 832 facing the drive motor 831. The width of the through slot 8321 is smaller than the rotation diameter of the output shaft of the drive motor 831. The eccentric shaft is inserted into the through slot 8321. The limit plate 834 is provided below the telescopic rod 542. The limit plate 834 is located on the side of the linkage plate 832 away from the slot bottom of the motor slot hole 610. The limit plate 834 is parallel to the mounting bar 602 and the linkage plate 832, and the limit plate 834 is slidably connected to the linkage plate 832 on the side facing the linkage plate 832. When the drive motor 831 is running, the linkage plate 832 can slide back and forth in its length direction. The side of the linkage plate 832 away from the limiting plate 834 contacts the friction telescopic shaft 820 , so that when the linkage plate 832 slides back and forth along the length direction of the limiting plate 834 , the linkage plate 832 can drive the friction telescopic shaft 820 to rotate.

[0061] Specifically, the drive motor 831 can be installed between two mounting plates 601, the output surface of the drive motor 831, that is, the side with the output shaft facing the mounting bar 602, the sleeve can be a metal sleeve fixed on the output shaft of the drive motor 831, and the sleeve is coaxially arranged with the output shaft of the drive motor 831. The eccentric shaft is fixed at the end of the sleeve away from the drive motor 831, the eccentric shaft is parallel to the output shaft of the drive motor 831, but the eccentric shaft is not coaxially arranged with the drive motor 831. The motor slot 610 can be provided on the side of the mounting bar 602 facing the drive motor 831, the linkage plate 832 is inserted into the motor slot 610 and can slide along the motor slot 610, the side walls of the linkage plate 832 can contact the side walls of the motor slot 610, and the side of the linkage plate 832 away from the drive motor 831 contacts the bottom of the motor slot 610, thereby realizing that the linkage plate 832 can slide along the axial direction of the motor slot 610. The through slot 8321 provided on the linkage plate 832 faces the drive motor 831, and the length direction of the through slot 8321 can be perpendicular to the central axis of the motor slot hole 610, and the end of the eccentric shaft away from the drive motor 831 is inserted into the through slot 8321, and the width of the through slot 8321 is smaller than the rotation diameter of the eccentric shaft. This makes it possible that when the drive motor 831 rotates, the eccentric shaft can always drive the linkage plate 832 to move back and forth / reciprocatingly in a direction parallel to the central axis of the motor slot hole 610. In addition, the limiting plate 834 provided below the telescopic rod 542 is in contact with the linkage plate 832, and the linkage plate 832 is slidably connected to the limiting plate 834. A sliding groove can be provided on the limiting plate 834, and a slider can be provided on the side of the linkage plate 832 facing the limiting plate 834, and the length direction of the sliding groove is parallel to the length direction of the central axis of the motor slot hole 610. The slider is inserted into the slide groove and can slide along the length direction of the slide groove, thereby realizing a sliding connection between the linkage plate 832 and the limit plate 834 .

[0062] In this embodiment, the linkage plate 832 can slide to the bottom of the friction telescopic shaft 820. When the driving motor 831 drives the eccentric shaft to rotate, the eccentric shaft can drive the linkage plate 832 to realize reciprocating motion in the length direction parallel to the limit plate 834, and then drive the friction telescopic shaft 820 to rotate reciprocatingly. The reciprocating friction telescopic shaft 820 can drive the corresponding rotating drum 810 to rotate.

[0063] See also Figure 10-12 Combined with Figure 1In the process of the processing frame 300 approaching the clamping frame 200, the rotating drum 810 will first contact the plastic sheet 210, which will make the thickness of the plastic sheet 210 at the rotating drum 810 relatively thick. As the rotating drum 810 reciprocates, the rotating drum 810 can always rely on its friction force to drive the thicker part of the plastic sheet 210 to move to the sides of the thicker part. Therefore, the reciprocating rotating drum 810 can flatten the thicker part of the plastic sheet 210, thereby making the thickness of the plastic sheet 210 at the position of the rotating drum 810 more uniform.

[0064] In some embodiments, Figures 10 to 12 As shown, a driving plate 833 is provided at the bottom of the linkage plate 832, and the driving plate 833 is arranged between the linkage plate 832 and the limiting plate 834 through a sliding assembly, and the sliding assembly includes a first inclined surface 8340 and a second inclined surface 8320. The first inclined surface 8340 is an end surface of the limiting plate 834 away from the telescopic rod 542, and the second inclined surface 8320 is an end surface of the linkage plate 832 close to the transmission belt 544. The first inclined surface 8340 and the second inclined surface 8320 are arranged at an angle, and the driving plate 833 is arranged in the angle area enclosed by the first inclined surface 8340 and the second inclined surface 8320, and the driving plate 833 is slidably arranged on the first inclined surface 8340 and the driving plate 833 is slidably connected to the second inclined surface 8320 on the side facing the second inclined surface 8320. When the linkage plate 832 moves in the direction away from the driving motor 831, the driving plate 833 is always slidably connected with the first inclined surface 8340 and the second inclined surface 8320, and the side of the driving plate 833 facing away from the first inclined surface 8340 is always in contact with the friction telescopic shaft 820, and the driving plate 833 can always drive the friction telescopic shaft 820 to rotate when moving on the first inclined surface 8340.

[0065] Specifically, the driving plate 833 is arranged in the angle area formed by the first inclined surface 8340 and the second inclined surface 8320. The first inclined surface 8340 and the second inclined surface 8320 are both facing the contact surface between the limiting plate 834 and the linkage plate 832. The angle area formed by the first inclined surface 8340 and the second inclined surface 8320 can be a right angle area. The driving plate 833 can be a rectangular body adapted to the right angle area. The two connected side surfaces of the driving plate 833 can be slidably connected to the first inclined surface 8340 and the second inclined surface 8320 respectively. When the linkage plate 832 moves downward relative to the limiting plate 834, that is, moves in a direction away from the mounting bar 602, the second inclined surface 8320 on the linkage plate 832 will push the driving plate 833 to move on the first inclined surface 8340 of the limiting plate 834 in a direction away from the mounting bar 602. When the linkage plate 832 moves upward relative to the limiting plate 834, that is, moves in a direction close to the mounting bar 602, the linkage plate 832 will drive the driving plate 833 to move on the first inclined surface 8340 of the limiting plate 834 in a direction close to the mounting bar 602. Since the output shaft of the driving motor 831 is eccentrically arranged, the eccentric output shaft can drive the linkage plate 832 to reciprocate in the motor slot hole 610 along the central axis of the motor slot hole 610. Therefore, the driving plate 833 will also reciprocate on the first inclined surface 8340. The reciprocating driving plate 833 can drive the corresponding friction telescopic shaft 820 to reciprocate, and then the rotating drum 810 can also reciprocate, which is beneficial to make the thickness of the plastic sheet 210 at the position of the rotating drum 810 more uniform, and helps to make the thickness of the plastic sheet 210 processed by the pretreatment mechanism more uniform during the initial forming.

[0066] Through the above arrangement, when the processing frame 300 approaches the clamping frame 200, the rotating drum 810 under the four rotating motors 740 will contact the plastic sheet 210 at the same time and can press down the plastic sheet 210. When the rotating motor 740 is running, the rotating motor 740 can drive the threaded shaft to rotate and then drive the rotating sleeve 710 to move. The movement of the rotating sleeve 710 can push the telescopic shell 530 to extend or shorten through the hinge rod 720 thereon, which will change the distance between the first support wheel 5411 and the second support wheel 5412, and then cause the length of the friction telescopic shaft 820 to change accordingly, which can change the pressing length of the transmission belt 544 or the rotating drum 810 on the plastic sheet 210, and then change the pressing area;

[0067] When the processing frame 300 approaches the clamping frame 200, that is, when the drum 810 is pressed down, the driving motor 831 is started, and the driving motor 831 drives the friction telescopic shaft 820 to rotate back and forth through the linkage plate 832 and the driving plate 833, and then drives the drum 810 to rotate back and forth. The reciprocating drum 810 can make the thickness of the plastic sheet 210 more uniform, and finally make the thickness of the plastic sheet 210 more uniform during the molding process of the plastic sheet 210. The preliminarily formed plastic sheet 210 with relatively uniform thickness is then evacuated by the vacuum system in the thermoforming mold 110 to form a plastic structural member with more uniform thickness, that is, the purpose of the present invention can be achieved.

[0068] In some embodiments, Figures 9 to 12 As shown, two fixed rods are arranged on the telescopic rod 542, and the two fixed rods are respectively close to the first support wheel 5411 and the second support wheel 5412, and the first auxiliary rod 901 and the second auxiliary rod 902 are respectively arranged on the two fixed rods. The length directions of the first auxiliary rod 901 and the second auxiliary rod 902 are parallel, and the first auxiliary rod 901 and the second auxiliary rod 902 are slidingly connected, and the first auxiliary rod 901 and the second auxiliary rod 902 both conflict with the rotating drum 810 on the transmission belt 544 located below the support wheel 541.

[0069] Specifically, the length direction of the two fixed rods can be perpendicular to the length direction of the telescopic rod 542, and the two fixed rods are respectively close to the first support wheel 5411 and the second support wheel 5412. The first auxiliary rod 901 and the second auxiliary rod 902 can be fixed on the two fixed rods respectively, and both are perpendicular to the length direction of the fixed rods. The first auxiliary rod 901 and the second auxiliary rod 902 are both located between the first support wheel 5411 and the second support wheel 5412, and are both located above the transmission belt 544 below the first support wheel 5411 and the second support wheel 5412. The first auxiliary rod 901 and the second auxiliary rod 902 are both in conflict with the rotating drum 810 on the transmission belt 544 below the first support wheel 5411 and the second support wheel 5412. The first auxiliary rod 901 and the second auxiliary rod 902 have a pressing effect on the rotating drum 810, the purpose of which is to enable the rotating drum 810 to be firmly pressed on the plastic sheet 210 (please refer to the drawings for details). Figure 1-Figure 4 ), so that when the rotating drum 810 rotates, the thicker parts in the area corresponding to the rotating drum 810 and the plastic sheet 210 can be evenly dispersed, so that the thickness of the initially formed plastic sheet 210 can be more uniform. It should be noted that the friction between the first auxiliary rod 901, the second auxiliary rod 902 and the rotating drum 810 is smaller than the friction between the rotating drum 810 and the friction telescopic shaft 820, and the friction between the friction telescopic shaft 820 and the driving plate 833, ensuring that when the first auxiliary rod 901 and the second auxiliary rod 902 are in contact with the rotating drum 810, the friction telescopic shaft 820 can still drive the rotating drum 810 to rotate, thereby ensuring the normal implementation of the present invention.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermoforming device for composite plastic sheets, characterized in that: include: A frame (100), wherein a thermoforming mold (110) and a vacuum extraction mechanism (120) are provided on the frame (100); a clamping frame (200), the clamping frame (200) being slidably disposed on the frame (100) and being located above the thermoforming mold (110), the clamping frame (200) being provided with a plastic sheet (210) capable of being fitted with a mold opening of the thermoforming mold (110); The processing frame (300) is slidably arranged on the frame (100) and is located above the clamping frame (200). The processing frame (300) is provided with a pre-processing mechanism, and the pre-processing mechanism includes a positioning plate (510) and a pressing mechanism. The positioning plate (510) is arranged on the processing frame (300), and a track hole is opened on the positioning plate (510). The pressing mechanism is movably arranged on the positioning plate (510). The pressing mechanism is provided with multiple groups, and the multiple groups of the pressing mechanisms correspond to the multiple inner side walls of the thermoforming mold (110) respectively. The pressing mechanism includes a movable shaft (520), a telescopic shell (530) and a rolling support assembly, the movable shaft (520) is inserted into the track hole and can be moved along the track hole by an external control mechanism, the telescopic shell (530) is arranged at the bottom end of the movable shaft (520), the length directions of the plurality of telescopic shells (530) are respectively parallel to the plurality of edges of the inner bottom surface of the thermoforming mold (110), a stretching mechanism is arranged between the movable shaft (520) and the telescopic shell (530), the stretching mechanism is used to control the telescopic movement of the telescopic shell (530), and the pretreatment mechanism is used to press down the plastic sheet (210) to form a prototype compatible with the thermoforming mold (110); A supporting frame (400), wherein the supporting frame (400) is slidably disposed on the frame body (100) and is located below the clamping frame (200), wherein a supporting assembly (410) is disposed on the supporting frame (400), wherein the supporting assembly (410) is provided in multiple groups, wherein the multiple groups of the supporting assembly (410) respectively correspond to the multiple groups of the pressing mechanisms, wherein the supporting assembly (410) comprises a supporting rod (411) and a supporting shaft (412), wherein the supporting rod (411) is rotatably disposed at both ends of the supporting shaft (412), wherein the supporting rod (411) is movably disposed on the supporting frame (400), wherein the supporting shaft (412) is parallel to the length direction of the corresponding telescopic shell (530) and is capable of supporting the plastic sheet (210), wherein the moving speed of the supporting shaft is adapted to the moving speed of the corresponding telescopic shell so that the prototype maintains synchronous expansion in the thermoforming mold; The supporting assembly (410) cooperates with the pretreatment mechanism so that the outer wall of the prototype corresponds to the inner wall of the thermoforming mold (110), and the distance between the outer wall of the prototype and the corresponding points on the inner wall of the thermoforming mold (110) keeps changing synchronously and evenly and finally remains consistent, and the vacuum extraction mechanism (120) is configured to absorb the air between the prototype and the thermoforming mold (110).

2. A thermoforming device for composite plastic sheets according to claim 1, characterized in that: The rolling support assembly is arranged in the telescopic shell (530), and the rolling support assembly includes a support wheel (541), a telescopic rod (542) and a roller (543). The support wheel (541) includes a first support wheel (5411) and a second support wheel (5412). The first support wheel (5411) and the second support wheel (5412) are both fixed in the telescopic shell (530) and are respectively close to two ends of the telescopic shell (530). The telescopic rod (542) is parallel to the length direction of the telescopic shell (530), and the telescopic rod (542) is connected between the first support wheel (5411) and the second support wheel (5412). 42) is provided with a mounting strip (602), the reel (543) includes a first reel (5431) and a second reel (5432), the first reel (5431) and the second reel (5432) are rotatably arranged at two ends of the mounting strip (602), respectively, a transmission belt (544) is wound around the first reel (5431), the transmission belt (544) sequentially passes around the first support wheel (5411) and the second support wheel (5412) and is finally wound around the second reel (5432), the lower section of the transmission belt (544) extends out of the bottom surface of the telescopic shell (530) and can be pressed on the plastic sheet (210).

3. A thermoforming device for composite plastic sheets according to claim 2, characterized in that: The reel (543) is provided with a coil spring, and the coil spring can enable the reel (543) to reel in the transmission belt (544), so that the transmission belt (544) is always kept in a tightened state.

4. A thermoforming device for composite plastic sheets according to claim 2, characterized in that: The movable shaft (520) is a threaded shaft, and the threaded shaft is rotatably connected to the telescopic shell (530). The stretching mechanism comprises a rotating motor (740), a rotating sleeve (710), a hinged rod (720) and a limiting rod (730). The rotating motor (740) is movably arranged on the positioning plate (510), and the threaded shaft is fixedly connected to the output shaft of the rotating motor (740). The rotating sleeve (710) is threadedly connected to the threaded shaft. The hinged rod (720) is provided with two The two hinged rods (720) are both hinged on the rotating sleeve (710) and are symmetrically arranged about the central axis of the rotating sleeve (710); one end of the hinged rod (720) away from the rotating sleeve (710) is hinged to the telescopic shell (530); the limiting rod (730) is fixed on the rotating motor (740), and the limiting rod (730) is arranged parallel to the threaded shaft; a limiting ring is provided on the rotating sleeve (710), and the limiting rod (730) is inserted into the limiting ring.

5. The thermoforming device for composite plastic sheets according to claim 2, characterized in that: The telescopic shell (530) is provided with a flattening mechanism, and the flattening mechanism includes a rotating drum (810), a friction telescopic shaft (820) and a driving assembly. The rotating drum (810) is rotatably arranged on the transmission belt (544). The rotating drum (810) located on the lower section of the transmission belt (544) protrudes from the bottom surface of the telescopic shell (530). The friction telescopic shaft (820) is rotatably arranged between the first support wheel (5411) and the second support wheel (5412). The length direction of the friction telescopic shaft (820) is aligned with the length direction of the lower section of the transmission belt (544). The drive assembly is arranged on the telescopic rod (542), and the drive assembly is used to drive the friction telescopic shaft (820) to reciprocate in its axial direction. The friction telescopic shaft (820) is in contact with the rotating drum (810) located on the lower section of the transmission belt (544). The rotation of the friction telescopic shaft (820) can drive the corresponding rotating drum (810) to rotate synchronously. The reciprocating rotation of the rotating drum (810) can flatten the plastic sheet (210), so that the thickness of the plastic sheet (210) at the rotating drum (810) is uniform.

6. A thermoforming device for composite plastic sheets according to claim 5, characterized in that: The driving assembly comprises a driving motor (831), a linkage plate (832) and a limiting plate (834); the driving motor (831) is arranged on the telescopic rod (542); the linkage plate (832) is slidably arranged on the mounting bar (602), and the sliding direction of the linkage plate (832) is perpendicular to the length direction of the mounting bar (602); an eccentric shaft is arranged on the output shaft of the driving motor (831); a through groove (8321) parallel to the length direction of the mounting bar (602) is opened on the linkage plate (832); the eccentric shaft is inserted into the through groove (8321); the width of the through groove (8321) is smaller than the rotation diameter of the eccentric shaft; the limiting plate (834) is arranged on the telescopic rod (542) and is slidably connected to the linkage plate (832); the side of the linkage plate (832) away from the limiting plate (834) contacts the friction telescopic shaft (820).

7. A thermoforming device for composite plastic sheets according to claim 6, characterized in that: A driving plate (833) is arranged at the bottom of the linkage plate (832), and the driving plate (833) is slidably arranged between the linkage plate (832) and the limiting plate (834) through a sliding component, and the sliding component includes a first inclined surface (8340) and a second inclined surface (8320), wherein the first inclined surface (8340) is an end surface of the limiting plate (834) away from the telescopic rod (542), and the second inclined surface (8320) is an end surface of the linkage plate (832) close to the transmission rod (542). An end surface of the lower section of the belt (544), the first inclined surface (8340) and the second inclined surface (8320) are arranged at an angle, the driving plate (833) is arranged in the angle area enclosed by the first inclined surface (8340) and the second inclined surface (8320), the driving plate (833) is slidably arranged on the first inclined surface (8340) and the side of the driving plate (833) facing the second inclined surface (8320) is slidably connected to the second inclined surface (8320); During the process of the linkage plate (832) moving toward the direction approaching the lower section of the transmission belt (544), the driving plate (833) is always slidably connected with the first inclined surface (8340) and the second inclined surface (8320), and the side of the driving plate (833) facing away from the first inclined surface (8340) is always in contact with the friction telescopic shaft (820), and the driving plate (833) can always drive the friction telescopic shaft (820) to rotate when moving on the first inclined surface (8340).

8. The thermoforming device for composite plastic sheets according to claim 7, characterized in that: The telescopic rod (542) is provided with a first auxiliary rod (901) and a second auxiliary rod (902), the first auxiliary rod (901) and the second auxiliary rod (902) are slidably connected, and the first auxiliary rod (901) and the second auxiliary rod (902) both contact the rotating drum (810) on the lower section of the transmission belt (544).

9. A thermoforming device for composite plastic sheets according to claim 8, characterized in that: The friction force between the rotating drum (810) and the first auxiliary rod (901) and the second auxiliary rod (902) is smaller than the friction force between the friction telescopic shaft (820) and the rotating drum (810) and the driving plate (833).

Images