阅读说明：本技术 一种塑料地球仪半球面的成型方法 (Method for forming hemispherical surface of plastic globe ) 是由 王国友 于 2020-11-02 设计创作，主要内容包括：一种塑料地球仪半球面的成型方法,包括以下步骤,将塑料片置于平台面上,盖住台面开口；上模体盖住塑料片,使成型凹部对准塑料片上的半球图案；成型凸部经加热后从台面开口伸出,塑料片表面受热变形而被顶入至成型凹部中；塑料片中部凸起,将塑料片在球面制作腔中制得成型片体；将能实现塑料片网格状间隔加热的成型凸粒分布在所述成型凸部外表面上,当所述成型凸部将置于加工面上的塑料片顶入至成型凹部中时,任意成型凸粒之间的成型凸部顶面与塑料片底面之间留有空隙。本发明的优点在于：改变了成型凸部的表面结构,当塑料片拉伸成型过程中,任一处直接受热的塑料片区域能与其他区域保持良好的位置关系,避免塑料片表面的地图图案变形。(A method for forming the hemispherical surface of plastic globe includes such steps as putting a plastic sheet on the surface of platform to cover the opening on said surface; the upper mold body covers the plastic sheet, so that the molding concave part is aligned to the hemispherical pattern on the plastic sheet; the molding convex part extends out of the opening of the table top after being heated, and the surface of the plastic sheet is heated and deformed to be pushed into the molding concave part; the middle part of the plastic sheet is raised, and the plastic sheet is made into a molded sheet body in the spherical surface manufacturing cavity; the plastic sheet forming convex grains capable of realizing grid-shaped interval heating of the plastic sheet are distributed on the outer surface of the forming convex part, and when the forming convex part pushes the plastic sheet arranged on the processing surface into the forming concave part, a gap is reserved between the top surface of the forming convex part between any two forming convex grains and the bottom surface of the plastic sheet. The invention has the advantages that: the surface structure of the forming convex part is changed, and when the plastic sheet is stretched and formed, the plastic sheet area directly heated at any position can keep a good position relation with other areas, so that the map pattern on the surface of the plastic sheet is prevented from being deformed.)

1. A method for forming the hemispherical surface of plastic globe includes such steps as providing a plastic globe,

firstly, a plastic sheet (8) for manufacturing a hemispherical surface is placed on a platform surface (11) of a lower die body (1), and a plastic sheet (8) area with a hemispherical pattern covers a platform surface opening (111) on the platform surface (11);

secondly, the upper die body (2) covers the plastic sheet (8), and a forming concave part (22) at the bottom of the upper die body (2) is aligned to the hemispherical pattern on the plastic sheet (8);

thirdly, a molding convex part (3) in the lower die body (1) is heated and then extends out of the opening (111) of the table surface, and the surface of the plastic sheet (8) is heated and deformed to be ejected into the molding concave part (22);

fourthly, the middle of the plastic sheet (8) is raised, and the plastic sheet (8) is made into a molding sheet body with a hemispherical shape in a spherical surface manufacturing cavity (23) formed between the outer surface of the molding convex part (3) and the inner wall of the molding concave part (22);

the method is characterized in that: the forming convex particles (31) capable of heating the plastic sheet (8) at intervals in a grid shape are distributed on the outer surface of the forming convex part (3), and when the forming convex part (3) pushes the plastic sheet (8) arranged on a processing surface into the forming concave part (22), a gap is reserved between the top surface of the forming convex part (3) among the forming convex particles (31) and the bottom surface of the plastic sheet (8).

2. The method for forming the hemispherical surface of a plastic globe according to claim 1, wherein: the top of die body (1) is provided with landing slab (10) down, landing face (11) are the top surface of landing slab (10), mesa opening (111) are the plate body through-hole that runs through landing slab (10).

3. The method for forming the hemispherical surface of the plastic globe according to claim 2, wherein: the number of the plate body through holes is two, the number of the forming concave parts (22) is two, the forming concave parts correspond to the plate body through holes respectively, and the number of the forming convex parts (3) is two, and the forming convex parts are arranged in the plate body through holes respectively.

4. The method for forming the hemispherical surface of a plastic globe according to claim 3, wherein: a cutting groove (101) is formed in a platform plate (10) between two plate body through holes, a cutting knife (102) capable of moving along the cutting groove (101) is arranged in the cutting groove (101), the knife tip of the cutting knife (102) extends out of the top opening of the cutting groove (101), and the cutting knife (102) is connected with a cutting knife driving mechanism (5) capable of driving the cutting knife (102) to move relative to the cutting groove (101).

5. The method for forming the hemispherical surface of the plastic globe according to any one of claims 1 to 4, wherein: and a positioning body (32) which can be inserted into the polar axis hole on the plastic sheet is arranged at the top end of the molding convex part (3).

6. The method for forming the hemispherical surface of the plastic globe according to claim 5, wherein: the top of the molding convex part (3) is provided with a groove (33) for installing a positioning body (32), the bottom of the positioning body (32) is connected in the groove (33) through an elastic mechanism (34), the top surface of the positioning body (32) extends out of the opening of the groove (33), the positioning body convex part (321) which can be spliced with the polar axis hole is positioned on the top surface of the positioning body (32), the bottom surface of the molding concave part (22) is provided with a pressing mechanism which can press the top surface of the positioning body (32) into the opening of the groove (33), the bottom of the groove (33) is provided with a communicating hole (35) which is communicated with the spherical surface manufacturing cavity (23) and the outside of the lower die body, and when the pressing mechanism presses the positioning body (32) downwards, the bottom surface of the positioning body (32) seals the communicating hole (35).

7. The method for forming the hemispherical surface of a plastic globe according to claim 6, wherein: the pressing mechanism comprises a driving cylinder (6) and a pressing sleeve (61), the driving cylinder (6) is connected to the upper die body (2), a concave through hole is formed in the middle of the forming concave portion (22), the bottom end of a cylinder rod (62) of the driving cylinder (6) penetrates through the concave through hole to be connected with the top of the pressing sleeve (61), and a pressing sleeve concave portion (611) capable of being sleeved with the positioning body convex portion (321) is formed in the bottom of the pressing sleeve (61).

8. The method for forming the hemispherical surface of the plastic globe according to any one of claims 1 to 4, wherein: the upper die body (2) and the lower die body (1) are arranged on the same rack (7), the upper die body (2) is a movable plate capable of moving up and down along a rack guide post (71), the die body driving mechanism (21) is a die body driving cylinder, a driving rod of the die body driving cylinder is connected with the movable plate, a forming seat (20) is arranged at the bottom of the movable plate, the forming concave part (22) is located on the bottom surface of the forming seat (20), a seat body through hole is formed in the middle of the bottom surface of the forming seat (20), and the bottom end of the pressing mechanism penetrates through the seat body through hole.

9. The method for forming the hemispherical surface of the plastic globe according to claim 8, wherein: the forming seat (20) comprises a first seat body (201) and a second seat body (202), a concave cavity capable of extending into the top of the second seat body (202) is formed in the bottom of the first seat body (201) at the periphery of the concave cavity, threaded holes are formed in the bottom surface of the first seat body (201) at the periphery of the concave cavity, a connecting ring is arranged on the side wall of the bottom of the second seat body (202), threaded through holes are formed in the connecting ring, the second seat body (202) is connected to the first seat body (201) through the connecting ring, and a hemispherical shell-shaped cavity (203) is reserved between the inner wall of the concave cavity of the first seat body (201) and the outer wall of the second seat body (202).

10. The method for forming the hemispherical surface of the plastic globe according to any one of claims 1 to 4, wherein: the convex part driving mechanism (4) comprises a moving seat (41), a driving screw rod (42) and a driving motor (43), the driving motor (43) is in transmission connection with the driving screw rod (42), the moving seat (41) can be sleeved on the driving screw rod (42) in a vertically moving mode along the driving screw rod (42), and the forming convex part (3) can be detachably connected to the moving seat (41).

Technical Field

The invention relates to the technical field of plastic globe manufacturing, in particular to a method for forming a hemispherical surface of a plastic globe.

Background

The prior Chinese patent application with the application number of CN201911154968.9 entitled globe assembling machine discloses a globe assembling machine, which comprises a pressing glue dispensing device, a first transfer device and a glue air drying device, the second transfer device, hot and cold laminating device and die-cut waste material and drilling equipment, put the casing and the map of south north hemisphere on pressfitting adhesive deposite device and carry out the pressfitting, first transfer device moves the south north hemisphere after the pressfitting to pressfitting adhesive deposite device's point and carries out the point and transfer the south north hemisphere after the point to glue air-dries the device on, glue air-dries the device air-dries the glue on the south north hemisphere, the second mobile device transfers the south north hemisphere after air-drying to the cold and hot laminating device of shell and transfers the accurate laminating of map on the south north hemisphere to the casing through expend with heat and contract with cold, the south north hemisphere after the second mobile device will laminate cuts on die-cut waste material and drilling equipment. The globe assembling machine can be used for attaching and assembling the shells of the south and north hemispheres and the map, and improves the production efficiency and the quality of produced products. However, the pressing mechanism of the assembling machine directly presses the outer spherical surface printed with the map on the hemispherical shell-shaped bladder, the map is originally a plane, if the map is directly pressed on the hemispherical shell-shaped bladder, the pattern of the pressed outer spherical surface is deformed, part of the proportion is distorted, the map display effect is not ideal, and if the map is firstly made into a hemispherical surface, the invention does not disclose a manufacturing method and a specific structure for realizing the method.

Disclosure of Invention

The invention aims to solve the technical problem of providing the forming method of the hemispherical surface of the plastic globe, which has the advantages of high forming efficiency of the stretching of the outer spherical surface, small deformation, good manufacturing effect and environmental protection, aiming at the current situation of the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows: the method for forming the hemispherical surface of the plastic globe comprises the following steps,

firstly, a plastic sheet for manufacturing a hemispherical surface is placed on a platform surface of a lower die body, and a plastic sheet area with a hemispherical pattern covers a platform surface opening on the platform surface;

secondly, the upper mold body covers the plastic sheet, so that the molding concave part at the bottom of the upper mold body is aligned to the hemispherical pattern on the plastic sheet;

thirdly, the molding convex part in the lower die body extends out of the opening of the table top after being heated, and the surface of the plastic sheet is deformed by heating and is pushed into the molding concave part;

fourthly, the middle of the plastic sheet is raised, and the plastic sheet is made into a molding sheet body with a hemispherical shape in a spherical surface manufacturing cavity formed between the outer surface of the molding convex part and the inner wall of the molding concave part;

the method is characterized in that: the plastic sheet forming convex grains capable of realizing grid-shaped interval heating of the plastic sheet are distributed on the outer surface of the forming convex part, and when the forming convex part pushes the plastic sheet arranged on the processing surface into the forming concave part, a gap is reserved between the top surface of the forming convex part between any two forming convex grains and the bottom surface of the plastic sheet.

As an improvement, the top of die body is provided with the landing slab down, the landing face is the top surface of landing slab, the mesa opening is the plate body through-hole that runs through the landing slab.

In a further improvement, the number of the plate body through holes is two, the number of the forming concave parts is two, the forming concave parts correspond to the respective plate body through holes respectively, and the number of the forming convex parts is two, and the forming convex parts are arranged in the respective plate body through holes respectively.

The cutting device is further improved, a cutting groove is formed in the platform plate between the through holes of the two plate bodies, a cutting knife capable of moving along the cutting groove is arranged in the cutting groove, the knife tip of the cutting knife extends out of the top opening of the cutting groove, and the cutting knife is connected with a cutting knife driving mechanism capable of driving the cutting knife to move relative to the cutting groove.

As an improvement, a positioning body which can be inserted into the polar axis hole on the plastic sheet is arranged at the top end of the molding convex part.

The improved structure comprises a forming concave part and a positioning body, wherein the forming concave part is provided with a polar shaft hole, the top end of the forming convex part is provided with a groove for installing the positioning body, the bottom of the positioning body is connected in the groove through an elastic mechanism, the top surface of the positioning body extends out of the groove opening, the positioning body convex part which can be spliced with the polar shaft hole is positioned on the top surface of the positioning body, and the bottom surface of the forming concave part is provided with a pressing mechanism which can press the top surface of the positioning body.

The pressing mechanism comprises a driving cylinder and a pressing sleeve, the driving cylinder is connected to the upper die body, a concave through hole is formed in the middle of the forming concave portion, the bottom end of a cylinder rod of the driving cylinder penetrates through the concave through hole to be connected with the top of the pressing sleeve, and a pressing sleeve concave portion capable of being sleeved into the convex portion of the positioning body is formed in the bottom of the pressing sleeve.

As an improvement, the upper die body and the lower die body are arranged on the same frame, the upper die body is a movable plate capable of moving up and down along a guide post of the frame, the die body driving mechanism is a die body driving cylinder, a driving rod of the die body driving cylinder is connected with the movable plate, a forming seat is arranged at the bottom of the movable plate, the forming concave part is positioned on the bottom surface of the forming seat, a seat body through hole is formed in the middle of the bottom surface of the forming seat, and the bottom end of the pressing mechanism penetrates through the seat body through hole.

The forming seat is further improved and comprises a first seat body and a second seat body, wherein a concave cavity capable of extending into the top of the second seat body is formed in the bottom of the first seat body, threaded holes are formed in the bottom surface of the first seat body on the periphery of the concave cavity, a connecting ring is arranged on the side wall of the bottom of the second seat body, threaded through holes are formed in the connecting ring, the second seat body is connected to the first seat body through the connecting ring, and a hemispherical shell-shaped cavity is reserved between the inner wall of the concave cavity of the first seat body and the outer wall of the second seat body.

As an improvement, the convex part driving mechanism comprises a moving seat, a driving screw rod and a driving motor, the driving motor is in transmission connection with the driving screw rod, the moving seat can be sleeved on the driving screw rod in a vertically moving mode along the driving screw rod, and the forming convex part can be detachably connected to the moving seat.

Compared with the prior art, the invention has the advantages that: the surface structure of the forming convex part is changed, the area to be heated of the plastic sheet is divided into grid-shaped units and is heated at intervals through the surface structure of the forming convex part which is arranged in a concave-convex way, the joint part of the plastic sheet and the forming convex particles is directly heated, indirect heat conduction is carried out between the plastic sheet and the surface of the forming convex part which is not provided with the forming convex particles, and the area of the directly heated plastic sheet is limited by the area of the indirect heat conduction plastic sheet around, so that the area of the directly heated plastic sheet at any position can keep good position relation with other areas in the stretching and forming process of the plastic sheet, the map pattern deformation on the surface of the plastic sheet is avoided, the technical problem that the uneven pattern deformation of the plastic sheet caused by heating is solved in the prior art because no talcum powder is added on the surface of the forming convex part, the use of, the production efficiency is correspondingly improved; the plastic sheet is positioned through the positioning body and the pressing mechanism, so that the manufacturing precision of the hemispheroid is improved, meanwhile, the pressing mechanism can realize the automatic downward displacement of the positioning body, the efficiency is improved, and the labor cost is reduced; the pressing mechanism seals a through hole which penetrates through the cylinder rod and is arranged above the vacuum pumping cavity, the positioning body can seal a communication hole at the bottom of the groove, sealing in the spherical surface manufacturing cavity is achieved, the plastic sheet can be adsorbed on the forming concave part after being stretched, and automatic separation of the plastic sheet and the forming convex part after forming is achieved; the southern and northern hemispheres can be preferably manufactured at the same time, the efficiency is further improved, and the formed plastic sheet can be automatically cut through the cutting mechanism, so that the next processing is facilitated.

Drawings

FIG. 1 is a perspective view of an embodiment of the present invention;

FIG. 2 is a perspective view of FIG. 1 at another angle;

FIG. 3 is a perspective view of FIG. 2 at another angle;

FIG. 4 is a perspective view of the forming cavity of FIG. 1 covering a deck surface;

FIG. 5 is a top view of FIG. 4;

FIG. 6 is a cross-sectional view taken along line A-A of the positioning body of FIG. 5 without the pressing mechanism pressing the positioning body;

FIG. 7 is a cross-sectional view taken along line B-B of FIG. 5;

FIG. 8 is an exploded view of the structure of FIG. 1;

FIG. 9 is an enlarged view of portion I of FIG. 6;

FIG. 10 is a schematic view of the structure of FIG. 9 with the plastic sheet inserted therein;

FIG. 11 is an enlarged view of section II of FIG. 7;

FIG. 12 is an enlarged view of section III of FIG. 8;

FIG. 13 is an enlarged view of the portion IV of FIG. 9;

FIG. 14 is an enlarged view of portion V of FIG. 10;

FIG. 15 is an enlarged view of section VI of FIG. 14;

FIG. 16 is a schematic view showing the distribution of the molding beads on the surface of the molding protrusion of FIG. 1;

FIG. 17 is a schematic view of another distribution of the shaped beads of FIG. 16.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in fig. 1 to 15, the method for forming the hemispherical surface of the plastic globe according to the present embodiment includes the following steps,

firstly, placing a plastic sheet 8 for manufacturing a hemispherical surface on a platform surface 11 of a lower die body 1, wherein the area of the plastic sheet 8 with a hemispherical pattern covers a platform surface opening 111 on the platform surface 11;

secondly, the upper mold body 2 covers the plastic sheet 8, so that the molding concave part 22 at the bottom of the upper mold body 2 is aligned with the hemispherical pattern on the plastic sheet 8;

thirdly, the molding convex part 3 in the lower mold body 1 extends out from the table surface opening 111 after being heated, and the surface of the plastic sheet 8 is deformed by heating and is pushed into the molding concave part 22;

fourthly, the middle part of the plastic sheet 8 is raised, and the plastic sheet 8 is made into a molding sheet body with a hemispherical shape in a spherical surface manufacturing cavity 23 formed between the outer surface of the molding convex part 3 and the inner wall of the molding concave part 22;

wherein molding projections 31 capable of heating plastic sheet 8 at intervals in a grid pattern are distributed on the outer surface of molding projections 3, and when molding projections 3 push plastic sheet 8 placed on the processing surface into molding recesses 22, a gap is left between the top surface of molding projection 3 and the bottom surface of plastic sheet 8 between arbitrary molding projections 31.

Preferably, in the third step, when the plastic sheet 8 is lifted to a certain height, the vacuum pumping chamber 203 of the upper mold body 2 is pumped to vacuum, and further the molding concave portion 22 is pumped to vacuum, so that the plastic sheet 8 is adsorbed in the molding concave portion. When the molding projections 3 are retracted after processing, the plastic sheet 8 is adsorbed in the molding recesses and separated from the top surfaces of the molding projections 3, thereby realizing automatic separation of the plastic sheet. After the molding convex part 3 is retreated, the vacuum pumping is finished, the molding concave part 22 is recovered to normal pressure, and the plastic sheet 8 and the upper mold body 2 are automatically separated. The above-mentioned certain height refers to the height of the plastic sheet 8 when it is lifted up to lie adjacent to the bottom surface of the molding recess 22. The above-mentioned certain height usually means that the distance between the plastic sheet 8 and the bottom surface of the molding recess 22 is 0 to 5 mm.

The forming device of the plastic globe hemisphere surface adopted by the method has the specific structure that the forming device comprises a lower die body 1 and an upper die body 2 which can move up and down relative to the lower die body 1, the upper die body 2 is connected with a die body driving mechanism 21, the bottom of the upper die body 2 is provided with a forming concave part 22 which can be adapted to the hemisphere surface, the top surface of the lower die body 1 is a platform surface 11 which can be used for placing a plastic sheet 8 for manufacturing the hemisphere surface, a platform surface opening 111 is arranged on the platform surface 11 and corresponds to the forming concave part 22, a forming convex part 3 which can be adapted to the hemisphere surface is arranged in the platform surface opening 111, the forming convex part 3 is connected with a heating mechanism which can heat the outer surface of the forming convex part 3, the forming convex part 3 is connected with the lower die body 1 through a convex part driving mechanism 4, when the forming concave part 22 covers the platform surface opening 111 and the forming convex, a spherical surface manufacturing cavity 23 for manufacturing a hemispherical surface is formed between the outer surface of the molding convex part 3 and the inner wall of the molding concave part 22, molding convex grains 31 capable of heating the plastic sheet 8 at intervals in a grid shape are distributed on the outer surface of the molding convex part 3, and when the molding convex part 3 pushes the plastic sheet 8 placed on the platform surface 11 into the molding concave part 22, a gap is left between the top surface of the molding convex part 3 and the bottom surface of the plastic sheet 8 among the arbitrary molding convex grains 31. The grid-shaped interval heating refers to that a surface to be heated is divided into grid-shaped units 9, one grid-shaped unit 9 is directly heated, the front, back, left and right units of the direct heating unit are not directly heated, similarly, one grid-shaped unit 9 is not directly heated, the front, back, left and right units of the direct heating unit are directly heated, the distribution mode extends infinitely and is cut at the position of a circular outer contour corresponding to a hemisphere, and two common grid-shaped division methods are shown in fig. 16 and 17. The heating mechanism can be an electric heating coil directly sleeved in the groove of the forming convex part 3, and the electric heating coil is connected with a power supply through a circuit. The heating mechanism may also be other heaters capable of realizing heat conduction on the surface of the forming convex part 3, and the specific structure of the heating mechanism is well known in the art and will not be described in detail.

The specific manufacturing method of the molding convex particles 31 on the surface of the molding convex part 3 by molding the molding convex particles 31 on the outer surface of the molding convex part 3 at one time or by sand blasting the surface of the molding convex part 3 belongs to the prior art, and the specific manufacturing method is selected according to the specific material of the molding convex part 3, so that the detailed description is omitted.

The top of the lower die body 1 is provided with a platform plate 10, the platform surface 11 is the top surface of the platform plate 10, and the platform opening 111 is a plate body through hole penetrating through the platform plate 10. Two plate body through holes are provided, two molding recesses 22 are provided and correspond to the respective plate body through holes, and two molding protrusions 3 are provided and are disposed in the respective plate body through holes. A cutting groove 101 is formed in the platform plate 10 between the through holes of the two plate bodies, a cutting knife 102 capable of moving along the cutting groove 101 is arranged in the cutting groove 101, the knife tip of the cutting knife 102 extends out of the top opening of the cutting groove 101, and the cutting knife 102 is connected with a cutting knife driving mechanism 5 capable of driving the cutting knife 102 to move relative to the cutting groove 101. The cutting knife driving mechanism 5 comprises a cutting knife driving cylinder, a cutting knife mounting seat 51 for mounting the cutting knife 102 and the cutting knife 102. The bottom setting of cutting knife mount pad 51 is on the plate body 103 of die body 1 down, and the lateral part of cutting knife mount pad 51 is connected with the cylinder rod that the cutting knife drove actuating cylinder, and the cylinder rod promotes cutting knife mount pad 51 back-and-forth movement on plate body 103 to make the most advanced of cutting knife 102 along cutting groove 101 back-and-forth movement, cut the plastic sheet middle part after the shaping, form two independent plastic sheets of taking protruding hemisphere face.

The top end of the molding convex part 3 is provided with a positioning body 32 which can be inserted into the polar axis hole on the plastic sheet. The top end of the molding convex part 3 is provided with a groove 33 for installing the positioning body 32, the bottom of the positioning body 32 is connected in the groove 33 through an elastic mechanism 34, the top surface of the positioning body 32 extends out of the opening of the groove 33, the positioning body convex part 321 which can be inserted into the polar axis hole is positioned on the top surface of the positioning body 32, and the bottom surface of the molding concave part 22 is provided with a pressing mechanism which can press the top surface of the positioning body 32 into the opening of the groove 33. The bottom of the groove 33 is provided with a communication hole 35 for communicating the spherical surface manufacturing cavity 23 with the exterior of the lower die body, and when the pressing mechanism presses the positioning body 32 downwards, the bottom surface of the positioning body 32 closes the communication hole 35. The resilient mechanism 34 may be a spring. The pressing mechanism closes the communication hole 35 to hold the plastic sheet 8 in the sealed cavity.

The pressing mechanism comprises a driving cylinder 6 and a pressing sleeve 61, the driving cylinder 6 is connected to the upper die body 2, a concave through hole is formed in the middle of the forming concave portion 22, the bottom end of a cylinder rod 62 of the driving cylinder 6 penetrates through the concave through hole to be connected with the top of the pressing sleeve 61, and a pressing sleeve concave portion 611 capable of being sleeved into the positioning body convex portion 321 is formed in the bottom of the pressing sleeve 61.

The upper die body 2 and the lower die body 1 are arranged on the same frame 7, the upper die body 2 is a movable plate capable of moving up and down along a frame guide post 71, the die body driving mechanism 21 is a die body driving cylinder, a driving rod of the die body driving cylinder is connected with the movable plate, a forming seat 20 is arranged at the bottom of the movable plate, a forming concave part 22 is positioned on the bottom surface of the forming seat 20, a seat body through hole is arranged in the middle of the bottom surface of the forming seat 20, and the bottom end of a pressing mechanism penetrates through the seat body through hole. The forming seat 20 comprises a first seat body 201 and a second seat body 202, a concave cavity capable of extending into the top of the second seat body 202 is arranged at the bottom of the first seat body 201, threaded holes are distributed on the bottom surface of the first seat body 201 around the concave cavity, a connecting ring is arranged on the side wall of the bottom of the second seat body 202, threaded through holes are distributed on the connecting ring, the second seat body 202 is connected to the first seat body 201 through the connecting ring, and a vacuum pumping cavity 203 is reserved between the inner wall of the concave cavity of the first seat body 201 and the outer wall of the second seat body 202. The vacuum pumping chamber 203 is communicated with a pumping port of the vacuum pumping mechanism. The specific structure of the vacuum pumping mechanism belongs to the known technology, and therefore, the detailed description is not provided. When the plastic sheet is lifted to a certain height by the molding convex part 3, the plastic sheet is adsorbed on the bottom surface of the molding concave part 22 due to the air suction effect in the vacuum suction chamber 203, so that when the molding convex part 3 retreats, the manufactured hemispherical plastic sheet is adsorbed in the molding concave part 22 without following the retreating of the molding convex part 3, after the retreating of the molding convex part 3, the vacuum suction is stopped, and the plastic sheet is separated from the molding concave part 22, thereby realizing the automatic separation of the plastic sheet from the upper mold body and the molding convex part 3. The pressing mechanism and the positioning body are matched to play a role in positioning the position of the plastic sheet 8, and the pressing mechanism presses the positioning body 32 downwards to cover the communicating hole 35, so that the spherical surface manufacturing cavity 23 is sealed, the sealing effect of the spherical surface manufacturing cavity 23 is guaranteed, and the plastic sheet can be effectively adsorbed on the forming concave part 22. A through hole capable of penetrating through the cylinder body of the driving cylinder 6 is formed in the top plate of the frame 7, and when the die body driving mechanism 21 lifts the upper die body 2, the cylinder body of the driving cylinder 6 penetrates through the through hole and extends to the upper side of the top plate.

The convex part driving mechanism 4 comprises a moving seat 41, a driving screw rod 42 and a driving motor 43, wherein the driving motor 43 is in transmission connection with the driving screw rod 42, the moving seat 41 can be sleeved on the driving screw rod 42 in a way of moving up and down along the driving screw rod 42, and the forming convex part 3 can be detachably connected on the moving seat 41.

The automatic control of the convex part driving mechanism 4, the die body driving mechanism 21, the heating mechanism, the pressing mechanism and the cutting knife driving mechanism 5 can be realized through the controller, and the specific circuit structure of the controller belongs to the prior art, so detailed description is omitted.

The working principle is as follows: and placing the plastic sheet on the platform surface, covering the upper mold body and the lower mold body, and lifting the heated molding convex part to push the plastic sheet into the molding concave part of the upper mold body so as to form a manufactured hemispherical surface. The plastic sheet has a larger deformation tendency, and the surface of the forming convex part between any forming convex particles is provided with a gap with the plastic sheet, so that the plastic sheet at the position does not directly receive heat, only receives the heat conduction effect of a small amount of plastic sheet directly receiving heat, and the deformation is small. The plastic sheet of directly accepting the heat department still can keep on original map pattern position when being heated and extending like this, and whole map pattern on the plastic sheet can keep good display effect, avoids proportion distortion and pattern deformation, has saved the talcum powder that uses for avoiding being heated unevenly among the prior art, has improved operational environment, and forming efficiency also correspondingly improves.