Injection mold for billboard shell and injection molding method thereof

Abstract

The present invention relates to the field of plastic molding, specifically to an injection mold for a billboard shell and an injection molding method thereof, comprising a mold base and a lower mold fixedly installed in the middle of the upper end of the mold base, an upper mold is arranged above the lower mold, a mold guide column is fixedly installed at the corner of the upper end surface of the lower mold, main carriers are arranged on both sides of the lower mold, the main carriers are elastically connected to the mold base, two ring shells are symmetrically arranged at the ends of the mold guide column, a sponge is installed inside the ring shell, the sponge is attached to the outer surface of the mold guide column, a pusher is installed on the main carrier, the pusher is connected to the ring shell and the upper mold respectively, a storage box is arranged at the upper end of the pusher, the storage box is connected to the ring shell, and lubricating oil is filled in the storage box. The present invention improves the service life of the injection mold, while also reducing the labor intensity of workers and avoiding the waste of lubricating oil.

Description

Technical Field

[0001] The invention relates to the field of plastic molding, in particular to an injection mold for a billboard shell and an injection molding method thereof. Background Art

[0002] Billboards are a general term for common hard advertisements, and generally refer to all carriers that convey advertising information. They are widely used in information transmission, display, advertising, etc., and are an important part of various commercial activities. Through billboards, businesses can convey information about products, services or brands to consumers, thereby attracting consumers' attention and promoting sales. In the process of making billboard shells, injection molds are often used for injection molding.

[0003] Injection molds are usually equipped with mold guide pins to enable the upper and lower molds to be accurately docked together when the molds are closed. In order to reduce the wear between the mold guide pins and the mold, the mold guide pins usually need to be lubricated. However, during the lubrication process, most workers manually lubricate them regularly, which greatly increases the labor intensity of the workers. At the same time, manual lubrication is prone to untimely lubrication, resulting in insufficient lubrication, which causes excessive wear of the mold guide pins and seriously affects the service life of the injection mold. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the background technology and to propose an injection mold for a billboard shell and an injection molding method thereof.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an injection mold for a billboard shell, comprising a mold base and a lower mold fixedly installed in the middle of the upper end of the mold base, an upper mold is arranged above the lower mold, and a mold guide column is fixedly installed at the corner of the upper end surface of the lower mold, and main carriers are arranged on both sides of the lower mold, and the main carriers are elastically connected to the mold base, and two annular shells are symmetrically arranged at the ends of the mold guide columns, and sponges are installed inside the annular shells, and the sponges are attached to the outer surface of the mold guide columns, and a pushing member is installed on the main carrier, and the pushing member is respectively connected to the annular shell and the upper mold, and a storage box is arranged on the upper end of the pushing member, and the storage box is communicated with the annular shell, and the storage box is filled with lubricating oil.

[0006] Preferably, an I-shaped frame is provided on the opposite sides of the two main carriers, and guide rods are fixedly installed at the front and rear ends of the I-shaped frame, and a frame guide sleeve is fitted on the outer surface of the guide rod, and the end of the frame guide sleeve is fixed to the main carrier, and a No. 2 return spring is wound around the outer side of the guide rod, one end of the No. 2 return spring is fixed to the upper end of the I-shaped frame, and the other end of the No. 2 return spring is fixed to the upper end of the frame guide sleeve.

[0007] Preferably, two guide columns are symmetrically fixedly installed on the side of the I-shaped frame, a column frame is fitted on the outer surface of the guide column, the end of the column frame is fixed to the mold base, a limiting column is fixedly installed on the side of the column frame, the end of the guide column is inlaid with a connecting cap, the connecting cap is fitted to the end of the limiting column, a No. 1 return spring is wound around the outer side of the guide column, one end of the No. 1 return spring is fixed to the connecting cap, and the other end of the No. 1 return spring is fixed to the side of the column frame.

[0008] Preferably, the upper end of the annular shell is fixedly connected to a hose, the end of the hose is fixedly connected to the oil outlet of the storage tank, the upper end of the storage tank is symmetrically fixedly installed with two L-shaped seats, the ends of the L-shaped seats are slidably penetrated by a pressure rod, the pressure rod extends into the interior of the storage tank, and the pressure rod slides with the storage tank.

[0009] Preferably, a plug is fixedly installed on the lower end of the pressure edge rod, and the plug corresponds to the oil outlet of the storage tank, and a compression spring is fixedly installed on the lower end of the L-shaped seat, and the pressure edge rod passes through the inside of the compression spring, and the end of the compression spring is fixed to the outer surface of the pressure edge rod, and a top wheel is installed on the outer surface of the pressure edge rod, and a top frame is fitted on the lower part of the top wheel, and the end of the top frame is fixed to the main carrier, and the upper end side edge of the top frame is inclined.

[0010] Preferably, the pushing member includes a sub-carrier slidably mounted on the upper end of the main carrier, a top shell frame is rotatably mounted on the end of the sub-carrier, a shell column is rotatably mounted on the end of the top shell frame, one end of the shell column is fixed to the annular shell, two ridges extend symmetrically from the outer surface of the shell column, the shell column and the ridges are slidably matched with the end of the main carrier, and the storage tank is fixed to the upper end of the sub-carrier.

[0011] Preferably, a No. 3 return spring is wound around the outer side of the shell column, one end of the No. 3 return spring is fixed to the main carrier, the other end of the No. 3 return spring is fixed to the other end of the shell column, two protruding guide frames are symmetrically fixedly installed on the lower end of the auxiliary carrier, and two T-shaped slide grooves are symmetrically opened on the upper end of the main carrier, and the ends of the protruding guide frames fit into the inside of the T-shaped slide grooves.

[0012] Preferably, two auxiliary push wheels are symmetrically installed on the side of the auxiliary carrier, a main push wheel is installed in the middle of the side of the main carrier, a main push frame is fitted on the side of the main push wheel, and auxiliary push plates are fixedly installed at the front and rear ends of the main push frame at an angle, the auxiliary push wheels are fitted on the auxiliary push plates, and a connecting frame is fixedly installed on the side of the main push frame, and the end of the connecting frame is fixed to the upper mold.

[0013] A method for injection molding a billboard housing is also provided, comprising the following steps:

[0014] S1: injecting molten plastic raw materials into the upper mold and the lower mold;

[0015] S2: After it is cooled and formed, the upper mold is pushed upward by the cylinder to separate the lower mold and the upper mold to complete the mold opening. In this process, the upper mold that moves upward will also drive the main push frame and the auxiliary push plate to move to push the main carrier and the auxiliary carrier so that the sponge on the ring shell can fit on the mold guide column. Then, the upper mold that moves upward drives the sponge to slide on the surface of the mold guide column to wipe the lubricating oil on the surface of the mold guide column by itself, so as to facilitate the next mold closing;

[0016] S3: After the mold is opened, the molded billboard shell can be taken out from the lower mold to complete the injection molding of the billboard shell.

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

[0018] 1. When the upper mold is removed from the upper mold, it will simultaneously drive the main push frame to move up and contact with the main push wheel, so that the main push wheel can roll on the inclined surface of the main push frame to push the main carrier and allow the main carrier to move sideways. At this time, the guide column slides on the column frame to guide the main carrier. At the same time, the No. 1 return spring contracts and deforms to adapt to the movement of the main carrier, so that the moving main carrier drives the ring shell to move to both sides of the mold guide column. At this time, the auxiliary push wheel just moves to the auxiliary push plate and the main push wheel moves to the vertical section of the main push frame. Then the main push frame continues to move up. At this time, the main push wheel rolls on the vertical section of the main push frame to keep the main carrier stationary. At the same time, the auxiliary push wheel rolls on the auxiliary push plate to drive the auxiliary carrier to move sideways, thereby driving The shell pusher frame moves to push the ring shell so that the two ring shells can be closed and the sponge on the ring shell can fit the surface of the mold guide column. At this time, the main push wheel just moves to the bottom of the main push frame, and then the main push frame continues to move up to push the main push wheel, thereby driving the sponge on the main carrier to move up. In this process, the frame guide sleeve slides on the guide rod to guide the main carrier. At the same time, the No. 2 reset spring contracts and deforms to adapt to one end of the main carrier, so that the moving sponge can automatically apply lubricating oil to the surface of the mold guide column. The process can automatically lubricate the mold guide column every time the mold is opened, thereby effectively reducing wear and tear, increasing the service life of the injection mold, and reducing the labor intensity of workers.

[0019] 2. The plug is provided to seal the oil outlet of the tank. When the auxiliary carrier drives the two ring shells to close, the top wheel on the tank will roll synchronously with the inclined surface of the top frame, thereby driving the pressure rod to slide upward in the tank, and then driving the plug upward, so that the plug is separated from the oil outlet of the tank, so that the lubricating oil in the tank can be discharged to be absorbed by the sponge and applied to the surface of the mold guide column. The process avoids the waste of lubricating oil caused by continuous discharge, thereby effectively avoiding the waste of lubricating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the mold guide column of the present invention;

[0022] Figure 3 It is a schematic diagram of the extending guide frame of the present invention;

[0023] Figure 4 For the present invention Figure 1 A magnified view of middle;

[0024] Figure 5 For the present invention Figure 1 Enlarged view of middle B;

[0025] Figure 6 For the present invention Figure 2 Enlarged view of middle C;

[0026] Figure 7 is an internal view of the tank of the present invention;

[0027] Figure 8 It is a schematic diagram of the main push frame of the present invention.

[0028] In the accompanying drawings, the list of components represented by each reference numeral is as follows: 1. Die base; 2. Lower die; 3. Upper die; 4. Die guide column; 5. Connecting frame; 6. Ring shell; 7. Auxiliary carrier; 8. Storage box; 9. I-shaped frame; 10. Extending guide frame; 11. L-shaped seat; 12. Compression spring; 13. Pressure edge rod; 14. Plug column; 15. Hose; 16. Sponge; 17. Top wheel; 18. Top frame; 19. T-shaped slide; 20. Main carrier; 21. Auxiliary push wheel; 22. Auxiliary push plate; 23. Main push frame; 24. Main push wheel; 25. Guide column; 26. Column frame; 27. Limit column; 28. Connecting cap; 29. ​​No. 1 reset spring; 30. Guide rod; 31. Frame guide sleeve; 32. No. 2 reset spring; 33. Protruding edge; 34. Shell column; 35. No. 3 reset spring; 36. Top shell frame. DETAILED DESCRIPTION

[0029] 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.

[0030] The present invention provides a technical solution: Figure 1 - Figure 8The injection mold of a billboard shell shown in the figure includes a mold base 1 and a lower mold 2 fixedly installed in the middle of the upper end of the mold base 1, an upper mold 3 is arranged above the lower mold 2, and the cavities of the lower mold 2 and the upper mold 3 match the shape of the billboard shell to be produced. The molten plastic raw material is injected into the upper mold 3 and the lower mold 2. After it is cooled and formed, the upper mold 3 is pushed upward by a cylinder to separate the lower mold 2 and the upper mold 3 to complete the mold opening. Then the molded billboard shell can be taken out from the lower mold 2 to complete the injection molding of the billboard shell. Because the above-mentioned mold opening method is a prior art and has been widely used, it is not elaborated here and is not shown in the figure. A mold guide column 4 is fixedly installed at the corner of the upper end surface of the lower mold 2. The mold guide The column 4 can guide the upper mold 3 so that the lower mold 2 and the upper mold 3 are accurately molded. Main carriers 20 are provided on both sides of the lower mold 2. The main carriers 20 are elastically connected to the mold base 1. Two annular shells 6 are symmetrically provided at the ends of the mold guide column 4. The main carrier 20 plays a role in supporting the annular shell 6. A sponge 16 is installed inside the annular shell 6. The annular shell 6 plays a role in supporting the sponge 16. The sponge 16 is attached to the outer surface of the mold guide column 4. A pusher is installed on the main carrier 20. The pusher is respectively connected to the annular shell 6 and the upper mold 3. The sponge 16 plays a role in applying lubricating oil to the mold guide column 4. A storage box 8 is provided on the upper end of the pusher. The storage box 8 is connected to the annular shell 6. The storage box 8 is filled with lubricating oil. The storage box 8 plays a role in storing the lubricating oil.

[0031] An I-shaped frame 9 is provided on the opposite side of the two main carriers 20. Guide rods 30 are fixedly installed at the front and rear ends of the I-shaped frame 9. The I-shaped frame 9 serves to support the guide rods 30. A frame guide sleeve 31 is fitted on the outer surface of the guide rod 30. The end of the frame guide sleeve 31 is fixed to the main carrier 20. The guide rod 30 and the frame guide sleeve 31 serve to vertically guide the main carrier 20. A No. 2 reset spring 32 is wound around the outer side of the guide rod 30. One end of the No. 2 reset spring 32 is fixed to the upper end of the I-shaped frame 9, and the other end of the No. 2 reset spring 32 is fixed to the upper end of the frame guide sleeve 31. The No. 2 reset spring 32 can push the frame guide sleeve 31 to reset the moved main carrier 20.

[0032] Two guide columns 25 are symmetrically fixedly installed on the side of the I-shaped frame 9, and a column frame 26 is fitted on the outer surface of the guide column 25. The guide column 25 and the column frame 26 can guide the I-shaped frame 9, and then horizontally guide the main carrier 20. The end of the column frame 26 is fixed to the mold base 1, and a limiting column 27 is fixedly installed on the side of the column frame 26. The end of the guide column 25 is inlaid with a connecting cap 28. The limiting column 27 can position the lateral displacement distance of the main carrier 20, and the connecting cap 28 is fitted to the end of the limiting column 27. A No. 1 return spring 29 is wound around the outer side of the guide column 25, one end of the No. 1 return spring 29 is fixed to the connecting cap 28, and the other end of the No. 1 return spring 29 is fixed to the side of the column frame 26. The No. 1 return spring 29 can reset the laterally displaced main carrier 20, and then allow the ring shell 6 to separate from between the lower mold 2 and the upper mold 3, so that the lower mold 2 and the upper mold 3 will not be hindered when the mold is closed.

[0033] The upper end of the annular shell 6 is fixedly connected with a hose 15, and the end of the hose 15 is fixedly connected with the oil outlet hole of the storage tank 8. The hose 15 serves to connect the annular shell 6 and the storage tank 8. Two L-shaped seats 11 are symmetrically fixedly installed on the upper end of the storage tank 8. The ends of the L-shaped seats 11 are slidably installed with a pressure edge rod 13, which extends into the interior of the storage tank 8. The L-shaped seat 11 serves to guide the pressure edge rod 13, and the pressure edge rod 13 slides with the storage tank 8.

[0034] A plug 14 is fixedly installed at the lower end of the edge pressing rod 13. The edge pressing rod 13 plays a role in supporting the plug 14. The plug 14 corresponds to the oil outlet of the storage tank 8. A clamping spring 12 is fixedly installed at the lower end of the L-shaped seat 11. The edge pressing rod 13 passes through the inside of the clamping spring 12, and the end of the clamping spring 12 is fixed to the outer surface of the edge pressing rod 13. The clamping spring 12 can push the moved edge pressing rod 13 to allow the plug 14 to enter the oil outlet of the storage tank 8 for sealing. A top wheel 17 is installed on the outer surface of the edge pressing rod 13. A top frame 18 is installed in close contact with the lower part of the top wheel 17, and the end of the top frame 18 is fixed to the main carrier 20. The upper side edge of the top frame 18 is inclined, which can push the top wheel 17 to move the edge pressing rod 13 upward, and the auxiliary carrier 7 drives the storage tank 8 to move, so that the top wheel 17 on the storage tank 8 rolls on the inclined surface of the top frame 18, thereby driving the edge pressing rod 13 to slide upward in the storage tank 8, and then driving the plug 14 to move upward, so that the plug 14 is separated from the oil outlet of the storage tank 8, so that the lubricating oil in the storage tank 8 can be discharged to be absorbed by the sponge 16.

[0035] The pushing member includes a sub-carrier 7 slidably mounted on the upper end of the main carrier 20, and a top shell frame 36 is rotatably mounted on the end of the sub-carrier 7. The sub-carrier 7 drives the top shell frame 36 to move, and a shell column 34 is rotatably mounted on the end of the top shell frame 36. One end of the shell column 34 is fixed to the annular shell 6, and two convex ridges 33 extend symmetrically from the outer surface of the shell column 34. The shell column 34 and the convex ridges 33 are slidably matched with the end of the main carrier 20. The shell column 34 guides the annular shell 6, and the convex ridges 33 prevent the shell column 34 from rotating. The storage box 8 is fixed to the upper end of the sub-carrier 7, and the sub-carrier 7 moves sideways to drive the top shell frame 36 to move, so as to push the annular shell 6, so that the two annular shells 6 can be closed, and the sponge 16 on the annular shell 6 can fit the surface of the mold guide column 4.

[0036] A No. 3 return spring 35 is wound around the outer side of the shell column 34, and one end of the No. 3 return spring 35 is fixed to the main carrier 20. The No. 3 return spring 35 serves to separate the closed annular shell 6, and the other end of the No. 3 return spring 35 is fixed to the other end of the shell column 34. Two protruding guide frames 10 are symmetrically fixedly installed at the lower end of the sub-carrier 7, and two T-shaped slide grooves 19 are symmetrically provided at the upper end of the main carrier 20. The protruding guide frames 10 and the T-shaped slide grooves 19 serve to guide the sub-carrier 7, and the end of the protruding guide frame 10 fits into the inside of the T-shaped slide groove 19.

[0037] Two auxiliary push wheels 21 are symmetrically installed on the side of the auxiliary carrier 7, and a main push wheel 24 is installed in the middle of the side of the main carrier 20. A main push frame 23 is installed on the side of the main push wheel 24, and the main push frame 23 can push the main push wheel 24, thereby driving the main carrier 20 to move sideways. The front and rear ends of the main push frame 23 are both tilted and fixedly installed with auxiliary push plates 22, and the auxiliary push wheels 21 are fitted on the auxiliary push plates 22, and the auxiliary push plates 22 can push the auxiliary push wheels 21, thereby driving the auxiliary carrier 7 to move sideways. A connecting frame 5 is fixedly installed on the side of the main push frame 23, and the connecting frame 5 plays a role in fixing the main push frame 23 and the upper mold 3 together, and the end of the connecting frame 5 is fixed to the upper mold 3.

[0038] A method for injection molding a billboard housing is also provided, comprising the following steps:

[0039] S1: injecting molten plastic raw material into the upper mold 3 and the lower mold 2;

[0040] S2: After cooling and forming, the upper mold 3 is pushed upward by the cylinder to separate the lower mold 2 and the upper mold 3 to complete the mold opening. In this process, the upper mold 3 that moves upward will also drive the main push frame 23 and the auxiliary push plate 22 to move, so as to push the main carrier 20 and the auxiliary carrier 7, so that the sponge 16 on the ring shell 6 can fit on the mold guide column 4, and then the sponge 16 is driven by the upper mold 3 that moves upward to slide on the surface of the mold guide column 4, so as to wipe the lubricating oil on the surface of the mold guide column 4 by itself, so as to facilitate the next mold closing;

[0041] S3: After the mold is opened, the molded billboard shell can be taken out from the lower mold 2 to complete the injection molding of the billboard shell.

[0042] When in use, the molten plastic raw material is injected into the upper mold 3 and the lower mold 2. After it is cooled and formed, the upper mold 3 is pushed upward by the cylinder to separate the lower mold 2 and the upper mold 3 to complete the mold opening. Then the molded billboard shell can be taken out from the lower mold 2 to complete the injection molding of the billboard shell. During the mold opening process, the upper mold 3 that moves upward will simultaneously drive the main push frame 23 to move upward and contact the main push wheel 24, so that the main push wheel 24 can roll on the inclined surface of the main push frame 23 to push the main carrier 20, so that the main carrier 20 can occur. The main carrier 20 moves sideways. At this time, the guide column 25 slides on the column frame 26 to guide the main carrier 20. At the same time, the No. 1 return spring 29 contracts and deforms to adapt to the movement of the main carrier 20. The moving main carrier 20 drives the ring shell 6 to move to both sides of the mold guide column 4. At this time, the auxiliary push wheel 21 just moves to the auxiliary push plate 22, and the main push wheel 24 moves to the vertical section of the main push frame 23. Then the main push frame 23 continues to move up. At this time, the main push wheel 24 rolls on the vertical section of the main push frame 23 to keep the main carrier 20 still. At the same time, the auxiliary push wheel 21 moves to the auxiliary push plate 22, and the main push wheel 24 moves to the vertical section of the main push frame 23. The push plate 22 rolls on the push plate 22 to drive the auxiliary carrier 7 to move sideways, thereby driving the top shell frame 36 to move, so as to push the ring shell 6, so that the two ring shells 6 can be closed, so that the sponge 16 on the ring shell 6 can fit the surface of the mold guide column 4. At this time, the main push wheel 24 just moves to the bottom of the main push frame 23. At the same time, the moving auxiliary carrier 7 will also drive the storage box 8 to move, so that the top wheel 17 on the storage box 8 rolls on the inclined surface of the top frame 18, thereby driving the pressing edge rod 13 to slide upward in the storage box 8, and then driving the plug 14 to move upward, so that the plug 1 4 is separated from the oil outlet of the storage tank 8, so that the lubricating oil in the storage tank 8 can be discharged to be absorbed by the sponge 16, and then the main push frame 23 continues to move upward to push the main push wheel 24, thereby driving the sponge 16 on the main carrier 20 to move upward. During this process, the frame guide sleeve 31 slides on the guide rod 30 to guide the main carrier 20, and the second return spring 32 contracts and deforms to adapt to one end of the main carrier 20, so that the moving sponge 16 can apply the lubricating oil to the surface of the mold guide column 4 by itself, so as to reduce the wear during the next mold closing.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An injection mold for a billboard shell, comprising a mold base (1) and a lower mold (2) fixedly mounted at the middle of the upper end of the mold base (1), an upper mold (3) being arranged above the lower mold (2), and a mold guide column (4) being fixedly mounted at the corner of the upper end surface of the lower mold (2), characterized in that: Main carriers (20) are provided on both sides of the lower mold (2), and the main carriers (20) are elastically connected to the mold base (1). Two annular shells (6) are symmetrically provided at the ends of the mold guide pillars (4). A sponge (16) is installed inside the annular shells (6), and the sponge (16) is attached to the outer surface of the mold guide pillars (4). A pusher is installed on the main carrier (20), and the pusher is connected to the annular shell (6) and the upper mold (3) respectively. A storage box (8) is provided at the upper end of the pusher, and the storage box (8) is connected to the annular shell (6). Lubricating oil is contained in the storage box (8); An I-shaped frame (9) is provided on the opposite sides of the two main carriers (20), and a guide rod (30) is fixedly installed at the front and rear ends of the I-shaped frame (9), and a frame guide sleeve (31) is fitted on the outer surface of the guide rod (30), and the end of the frame guide sleeve (31) is fixed to the main carrier (20), and a second return spring (32) is wound around the outer side of the guide rod (30), one end of the second return spring (32) is fixed to the upper end of the I-shaped frame (9), and the other end of the second return spring (32) is fixed to the upper end of the frame guide sleeve (31); Two guide columns (25) are symmetrically fixedly installed on the side of the workpiece frame (9), and a column frame (26) is fitted on the outer surface of the guide column (25). The end of the column frame (26) is fixed to the mold base (1), and a limiting column (27) is fixedly installed on the side of the column frame (26). The end of the guide column (25) is inlaid with a connecting cap (28), and the connecting cap (28) is fitted on the end of the limiting column (27). A No. 1 return spring (29) is wound around the outer side of the guide column (25), one end of the No. 1 return spring (29) is fixed to the connecting cap (28), and the other end of the No. 1 return spring (29) is fixed to the side of the column frame (26); The upper end of the annular shell (6) is fixedly connected to a hose (15), the end of the hose (15) is fixedly connected to the oil outlet of the tank (8), the upper end of the tank (8) is symmetrically fixedly mounted with two L-shaped seats (11), the ends of the L-shaped seats (11) are penetrated by a slidable pressure rod (13), the pressure rod (13) extends into the interior of the tank (8), and the pressure rod (13) is slidably matched with the tank (8); A plug post (14) is fixedly mounted on the lower end of the edge pressing rod (13), and the plug post (14) corresponds to the oil outlet hole of the storage tank (8). A compression spring (12) is fixedly mounted on the lower end of the L-shaped seat (11). The edge pressing rod (13) passes through the interior of the compression spring (12), and the end of the compression spring (12) is fixed to the outer surface of the edge pressing rod (13). A top wheel (17) is mounted on the outer surface of the edge pressing rod (13), and a top frame (18) is fitted on the lower part of the top wheel (17). The end of the top frame (18) is fixed to the main carrier (20), and the upper end side edge of the top frame (18) is inclined. The pushing member comprises a sub-carrier (7) slidably mounted on the upper end of the main carrier (20); a top shell frame (36) is rotatably mounted on the end of the sub-carrier (7); a shell column (34) is rotatably mounted on the end of the top shell frame (36); one end of the shell column (34) is fixed to the annular shell (6); two convex ridges (33) are symmetrically extended from the outer surface of the shell column (34); the shell column (34) and the convex ridges (33) are slidably matched with the end of the main carrier (20); and the storage box (8) is fixed to the upper end of the sub-carrier (7); A No. 3 return spring (35) is wound around the outer side of the shell column (34), one end of the No. 3 return spring (35) is fixed to the main carrier (20), and the other end of the No. 3 return spring (35) is fixed to the other end of the shell column (34); two extending guide frames (10) are symmetrically fixedly mounted on the lower end of the auxiliary carrier (7); two T-shaped slide grooves (19) are symmetrically opened on the upper end of the main carrier (20), and the ends of the extending guide frames (10) are fitted into the inside of the T-shaped slide grooves (19); Two secondary push wheels (21) are symmetrically mounted on the side of the secondary carrier (7), a main push wheel (24) is mounted in the middle of the side of the main carrier (20), a main push frame (23) is fitted on the side of the main push wheel (24), secondary push plates (22) are fixedly mounted at an angle on the front and rear ends of the main push frame (23), the secondary push wheels (21) are fitted on the secondary push plates (22), a connecting frame (5) is fixedly mounted on the side of the main push frame (23), and an end of the connecting frame (5) is fixedly mounted on the upper mold (3).

2. A method for injection molding a billboard shell, used in the injection molding mold for a billboard shell according to claim 1, characterized in that: The following steps are involved: S1: injecting molten plastic raw material into the upper mold (3) and the lower mold (2); S2: After the mold is cooled and formed, the upper mold (3) is pushed upward by a cylinder to separate the lower mold (2) and the upper mold (3) to complete the mold opening. During this process, the upper mold (3) that moves upward will also drive the main push frame (23) and the auxiliary push plate (22) to move, so as to push the main carrier (20) and the auxiliary carrier (7), so that the sponge (16) on the ring shell (6) can fit on the mold guide column (4), and then the sponge (16) is driven by the upper mold (3) that moves upward to slide on the surface of the mold guide column (4), so as to wipe the lubricating oil on the surface of the mold guide column (4) by itself, so as to facilitate the next mold closing; S3: After the mold is opened, the molded billboard shell can be taken out from the lower mold (2), and the injection molding of the billboard shell is completed.

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