A plastic tray forming mold structure

Abstract

This application relates to the field of injection molding technology for semiconductor packaging and testing products, and in particular to a plastic tray molding die structure. The upper die core has an upper forming hole protrusion on its lower surface, and the lower die core has a lower forming hole protrusion on its upper surface. In the closed state, the upper forming hole protrusion is in contact with the upper surface of the lower die core, and the lower forming hole protrusion is in contact with the lower surface of the upper die core. Both the upper and lower forming hole protrusions have stepped grooves in their middle sections, and pressure relief holes are formed at the bottom of the stepped grooves, extending out of the die body. The upper die core has a longitudinally arranged insert, into which a longitudinally movable abutting insert is embedded. In the closed state, the bottom of the abutting insert is in contact with the upper surface of the lower die core, and the top of the abutting insert abuts against the bottom of the clearance groove of the upper die base. In the open state, the upper die core moves upward, and the abutting insert, under gravity, can remain on the side of the lower die core and eject the molded product downward onto the lower die core. This reduces the scrap rate and improves injection molding accuracy and demolding reliability.

Description

Technical Field

[0001] This application relates to the field of injection molding technology for semiconductor packaging and testing products, and in particular to a plastic tray molding die structure. Background Technology

[0002] In the field of injection molding, the application scope of plastic products has been continuously expanding in recent years with the booming development of the manufacturing industry. In the semiconductor packaging and testing industry, chip packaging and testing is a crucial step. Plastic trays, as packaging carriers for chip packaging and testing, play a key role, protecting chips from damage during transportation and testing, and ensuring accurate chip positioning to guarantee testing accuracy. With advancements in chip technology, the requirements for the precision and quality of plastic trays are becoming increasingly stringent. The complex internal structure of plastic trays, such as various shapes of through-holes and grooves, presents significant challenges to the injection molding process. Improving the precision and product quality of injection molding is of great significance for reducing production costs, increasing production efficiency, and enhancing product market competitiveness.

[0003] In existing injection molding technology, injection molds typically include a mold body and an injection mechanism, a cooling mechanism, and an ejection mechanism located inside the mold body. The mold body includes an openable fixed mold and a moving mold; when the moving mold and fixed mold are closed, they form a molding cavity. The injection unit injects high-temperature molten liquid into the molding cavity from the injection mechanism. Under the action of the cooling mechanism, the molten liquid in the molding cavity can quickly solidify and form the product. Then, the ejection mechanism ejects the formed product. This conventional injection mold structure and working method is a widely used approach in the industry and can meet the production needs of plastic products to a certain extent.

[0004] However, the processing precision of domestic workpieces has reached its limit, as has the fitting precision of injection molds. This is a problem that is widely recognized as difficult to overcome within the industry. The internal structure of plastic trays is complex. During the injection molding process, the pressure in the molding cavity is relatively high, and existing molds cannot achieve very high fitting precision. Especially for injection liquids with low viscosity, under high pressure in the molding cavity, the injection liquid is prone to flowing into the gaps of the parting surface, causing flash to appear at the through holes of the injection molded product, resulting in a high scrap rate. In addition, due to the complex internal structure of plastic trays, combined with the clamping force of plastic cooling and shrinkage on the mold core, the product tends to move with the upper mold when the existing injection mold is opened, leading to difficulties in demolding. Summary of the Invention

[0005] In order to reduce scrap rate, improve injection molding accuracy and demolding reliability, and avoid flash at the through holes of the product, this application provides a plastic pallet molding die structure.

[0006] A plastic pallet molding die structure includes a die body, an injection molding mechanism, a cooling mechanism, and an ejection mechanism. The die body, from top to bottom, comprises an upper die cover plate, a manifold plate, an upper die base, a lower die base, a support base, and a lower die bottom plate. The upper die base has an upper die core at its bottom, and the lower die base has a lower die core at its top. The upper die core and the lower die core are closed to form a molding cavity. The lower surface of the upper die core has an upper forming hole protrusion, and the upper surface of the lower die core has a lower forming hole protrusion. In the closed state, the upper forming hole protrusion is in contact with the upper surface of the lower die core, and the lower forming hole protrusion is in contact with the lower surface of the upper die core. Both the upper and lower forming hole protrusions have stepped grooves in their middle portions, and pressure relief holes are formed at the bottom of the stepped grooves, extending out of the die body. The body is connected to an external pressure regulating mechanism; the upper mold core is longitudinally provided with a through-hole corresponding to the position of the upper hole protrusion, and a retaining block that can move longitudinally against the wall of the retaining hole is sealed and embedded in the retaining hole. The lower surface of the upper mold base is recessed with a relief groove corresponding to the position of the retaining block. In the mold closed state, the bottom of the retaining block is in contact with the upper surface of the lower mold core, the top of the retaining block is in contact with the bottom of the relief groove, and the retaining block is not in contact with the wall of the retaining hole; in the mold open state, the upper mold core moves upward, and the retaining block can be retained on the side of the lower mold core under the action of gravity and push the molded product downward onto the lower mold core until the retaining block abuts against the wall of the retaining hole, and then the upper mold core drives the retaining block to move upward synchronously.

[0007] By adopting the above technical solution, during injection molding, the pressure inside the molding cavity increases, and the injection molten metal is prone to flowing into the gaps between the upper hole protrusion and the lower mold core, and between the lower hole protrusion and the upper mold core due to high pressure, leading to problems such as flash on the product. However, by adjusting the air pressure of the stepped groove through the pressure regulating mechanism, the pressure difference between the molding cavity and the stepped groove can be changed, causing the stepped groove to form an air pressure barrier, effectively preventing the injection molten metal from flowing into the aforementioned gaps, improving injection molding accuracy, thereby avoiding flash at the through-holes of the product, reducing scrap rate, and improving product quality. Even if the mold fitting accuracy cannot exceed the upper limit, making it impossible to completely eliminate the gaps between the upper hole protrusion and the lower mold core, and between the lower hole protrusion and the upper mold core, the pressure difference between the molding cavity and the stepped groove in this application can greatly reduce the likelihood of the injection molten metal flowing into the gaps between the upper hole protrusion and the lower mold core, and between the lower hole protrusion and the upper mold core due to high pressure, thus reducing the problems such as flash on the product. Meanwhile, the upper mold core is equipped with a recessed hole corresponding to the protruding position of the upper hole. When the mold is closed, the bottom of the recessed insert is in contact with the upper surface of the lower mold core, and the top of the recessed insert is in contact with the bottom of the clearance groove. The recessed insert does not contact the wall of the recessed hole, which can ensure the sealing of the mold closing. When the mold is opened, the upper mold core moves upward, and the recessed insert is held on the side of the lower mold core under the action of gravity and pushes the molded product downward onto the lower mold core until it contacts the wall of the recessed hole and moves upward synchronously with the upper mold core. This structural design allows the molded product to be smoothly ejected from the upper mold core to the lower mold core first. Then, because the ejection structure is set below the lower mold core, the molded product is ejected upward from the lower mold core through the ejection structure, which improves the reliability of demolding, improves production efficiency, and ensures the molding quality of the product.

[0008] Preferably, the top edge of the abutting insert extends horizontally to form a limiting portion, and the wall of the insert hole extends horizontally to form a limiting groove for the limiting portion to abut longitudinally.

[0009] By adopting the above technical solution, a limiting part extends horizontally from the top edge of the abutment insert, and a limiting groove extends horizontally from the wall of the insert hole, allowing the limiting part to abut longitudinally. This structure ensures that the abutment insert can be removed from above the insert hole, but not from below. During mold opening, the upper mold core moves upward, but the abutment insert, under the action of gravity, remains on the side of the lower mold core and is ejected downward onto the lower mold core. After the abutment insert moves upward a certain distance with the upper mold core, the limiting part abuts longitudinally with the limiting groove, thereby limiting the upward movement range of the abutment insert, preventing the abutment insert from detaching from the insert hole, ensuring the stability and reliability of the abutment insert during mold opening and closing, thus ensuring the normal operation of the mold, improving the quality of the molded product and production efficiency.

[0010] Preferably, the thickness of the abutting insert is greater than the thickness of the lower mold core.

[0011] By adopting the above technical solution, since the thickness of the abutment insert is greater than the thickness of the lower mold core, when the mold opens, the upper mold core moves upward, and the abutment insert remains on the side of the lower mold core due to gravity. This ensures that when the mold closes, the bottom of the abutment insert fits against the top of the lower hole protrusion, the top of the abutment insert abuts against the bottom of the relief groove, and the abutment insert does not abut against the wall of the hole. This avoids the situation where the abutment insert moves upward due to excessive pressure in the molding cavity during injection molding, thus causing the hole to fail. It also ensures that after the mold opens, the upper mold core moves upward, and the abutment insert can remain on the side of the lower mold core under gravity and push the molded product downward onto the lower mold core.

[0012] Preferably, the abutment block is longitudinally provided with the pressure relief hole extending through its thickness.

[0013] By adopting the above technical solution, the abutting insert is longitudinally provided with a pressure relief hole that penetrates its thickness. When injection molding is performed, the pressure inside the molding cavity increases. Since the pressure relief hole penetrates the abutting insert, the pressure inside the molding cavity can be transmitted to the pressure regulating mechanism through the pressure relief hole. The pressure regulating mechanism can adjust the pressure, thereby balancing the pressure inside the molding cavity, preventing the injection molding liquid from flowing into the gap between the upper hole protrusion and the lower mold core, and between the lower hole protrusion and the upper mold core. This avoids flash at the through hole of the injection molded product, reduces the scrap rate, and improves product quality and production efficiency.

[0014] Preferably, the upper mold core is internally equipped with a slider and a slider driver. The slider is located within the clearance groove. The slider includes an integrally formed abutment portion and an ejector portion. The abutment portion is rectangular, with its top abutting against the bottom of the clearance groove and its bottom abutting against the top of the abutment block. The ejector portion is wedge-shaped, and its lower surface is provided with a guide slope. The guide slope is arc-shaped and connected to the lower surface of the abutment portion. The guide slope is inclined upward towards the lower surface of the abutment portion. The slider driver is fixedly mounted on the outer wall of the upper mold base, and its output end extends into the upper mold base to drive the slider to slide horizontally so that the guide slope ejects the abutment block downward.

[0015] By adopting the above technical solution, the slider drive is fixedly installed on the outer wall of the upper mold base, and its output end extends into the interior of the upper mold base to drive the slider to slide horizontally within the clearance groove. Since the slider includes an integrally formed abutment part and an ejector part, the top of the abutment part abuts against the bottom of the clearance groove, and the bottom abuts against the top of the abutment block. The ejector part is wedge-shaped and has a guide slope on its lower surface, which slopes upwards towards the lower surface of the abutment part. When the slider slides horizontally, the guide slope contacts the abutment block. As the slider continues to move, the guide slope exerts a downward force on the abutment block, thereby ejecting the abutment block downwards. This further achieves the effect of assisting in the ejection of the molded product, improving the efficiency and reliability of product ejection, and avoiding the unexpected situation where the abutment block fails to remain under gravity.

[0016] Preferably, all the pressure relief holes of the upper mold core converge into the upper air supply channel, which is sealed between the upper mold core and the upper mold base, with its air outlet extending beyond the outer surface of the upper mold core; all the pressure relief holes of the lower mold core converge into the lower air supply channel, which is sealed between the lower mold core and the lower mold base, with its air outlet extending beyond the outer surface of the lower mold core; both the upper and lower air supply channels are sealed and connected to an external pressure regulating mechanism.

[0017] By adopting the above technical solution, the pressure relief holes of the upper mold core converge into the upper air supply channel, and the pressure relief holes of the lower mold core converge into the lower air supply channel. The pressure regulating mechanism is a conventional air supply structure, which includes a guide pipe, a flow regulating valve, and an air supply component. The guide pipe connects the upper and lower air supply channels to the air supply component, and the flow regulating valve can regulate the gas flow rate delivered by the air supply component. When the flow rate is adjusted to increase the air pressure in the stepped groove, an air pressure barrier can be formed during the injection molding process, effectively preventing the injection molding liquid from flowing into the gaps between the upper hole protrusion and the lower mold core, and between the lower hole protrusion and the upper mold core. This avoids flash at the through-hole of the product due to the injection molding liquid flowing into the gaps, reduces the scrap rate, and improves product quality and production efficiency.

[0018] Preferably, both the upper mold core and the lower mold core are split mold core structures formed by splicing multiple modules along the horizontal direction, and each module can be disassembled and installed individually.

[0019] By adopting the above technical solution, since both the upper and lower mold cores are made of multiple modules spliced ​​together in the horizontal direction to form a split mold core structure, and each module can be disassembled and set up independently, when a certain module is damaged or worn, it is not necessary to replace the entire upper or lower mold core. The damaged module can be disassembled and replaced separately. This can reduce the maintenance cost and maintenance time of the mold, and at the same time facilitate the local adjustment and optimization of the mold, thereby improving the maintainability and flexibility of the mold.

[0020] Preferably, a plurality of gaps are provided between adjacent modules, each gap extending upward beyond the upper surface of the module, and each gap extending downward without communicating with the molding cavity.

[0021] By adopting the above technical solution, since there are several gaps between adjacent modules that extend upwards from the upper surface of the module and downwards without communicating with the molding cavity, the pressure inside the molding cavity is relatively large during the injection molding process. However, these gaps can provide a certain buffer space, allowing the module to have a small deformation space when subjected to pressure. This avoids stress concentration and damage at the module joints due to excessive pressure. It also reduces the risk of injection molding liquid leakage due to loose bonding between modules, thereby improving the quality of injection molded products and reducing the scrap rate.

[0022] Preferably, the upper mold cover plate has an injection port in the middle, the manifold plate has a manifold channel, the upper mold base and the upper mold core have injection channels, the injection port, the manifold channel, the injection channel and the molding cavity are connected in sequence, and the injection mechanism is provided with an integrally formed sprue cup, a manifold part and a plurality of injection tube parts from top to bottom. The sprue cup is embedded in the injection port of the upper mold cover plate, the manifold part is embedded in the manifold channel of the manifold plate, and each of the injection tube parts is embedded in the injection channel of the upper mold base, and its outlet extends downward and penetrates the upper mold core.

[0023] By adopting the above technical solution, the sprue cup of the injection molding mechanism is embedded in the injection port of the upper mold cover plate, the flow divider is embedded in the flow channel of the flow divider plate, and each injection tube is embedded in the injection channel of the upper mold base. The discharge port extends downward and penetrates the upper mold core. Since the injection port, flow divider, injection channel and molding cavity are connected in sequence, the injection liquid can enter from the sprue cup, and the flow divider evenly distributes the injection liquid to each injection tube, and then smoothly flows into the molding cavity. This achieves efficient and stable delivery of the injection liquid to the molding cavity, which helps to improve the molding quality of the plastic tray.

[0024] Preferably, the ejection mechanism includes a fixed plate, a plurality of ejector rods and an ejector rod drive component. The fixed plate is slidably disposed within the support base. A plurality of ejector rods are vertically fixed on the upper surface of the fixed plate. The top of each ejector rod extends vertically upward and penetrates the lower mold base and the lower mold core. The ejector rod drive component drives the fixed plate to move upward so that each ejector pin ejects the molded product upward.

[0025] By adopting the above technical solution, the fixed plate of the ejection mechanism is slidably disposed within the support base, and an ejector rod is fixed on the fixed plate, which passes through the lower mold base and the lower mold core. When the ejector rod drive drives the fixed plate to move upward, the fixed plate drives the ejector rod to move upward synchronously. Since the top of the ejector rod is located below the molded product, the upward movement of the ejector rod can directly act on the molded product, thereby ejecting the molded product upward and realizing the separation of the molded product from the mold, which facilitates the subsequent collection and processing of the molded product.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. Both the upper and lower forming protrusions have stepped grooves in their middle sections. The bottom of each stepped groove has a pressure relief hole connected to a pressure regulating mechanism. By adjusting the air pressure in the stepped grooves through the pressure regulating mechanism, the pressure difference between the molding cavity and the stepped grooves can be changed, creating a pressure barrier. This prevents the injection molding liquid from flowing into the gaps between the upper and lower forming protrusions, and between the lower and upper forming protrusions. This improves injection molding accuracy and avoids the injection molding liquid flowing into the parting surface gap due to insufficient fitting accuracy of existing molds. This solves the problem of flash at the through-holes in the product, reduces the scrap rate, and improves product quality. 2. The upper mold core has a longitudinally arranged insert hole corresponding to the position of the upper hole protrusion. A longitudinally movable abutment block is sealed and embedded in the insert hole. In the mold closed state, the bottom of the abutment block is in contact with the upper surface of the lower mold core, and the top of the abutment block abuts with the bottom of the relief groove. The abutment block does not abut with the wall of the insert hole, which can ensure the sealing of the mold closed state. In the mold open state, the upper mold core moves upward, and the abutment block can stay on the side of the lower mold core under the action of gravity and push the molded product downward onto the lower mold core until the abutment block abuts with the wall of the insert hole. Then the upper mold core drives the abutment block to move upward synchronously. This facilitates the demolding of the molded product and improves the demolding reliability. 3. Both the upper and lower mold cores are split mold core structures formed by splicing multiple modules along the horizontal direction. Each module can be disassembled and set up independently. When a certain part of the mold is damaged or needs to be replaced, the corresponding module can be directly disassembled for repair or replacement without replacing the entire mold. This facilitates the repair and replacement of parts of the mold and reduces the maintenance cost of the mold. Attached Figure Description

[0027] Figure 1 This is an exploded view of the plastic pallet molding die structure of this application; Figure 2 This is a structural diagram of the plastic pallet molding die structure of this application; Figure 3 This is a structural diagram of the upper and lower mold cores of the plastic pallet molding mold in the present application, in the mold-closed state; Figure 4 This is an exploded view of the upper mold core, the product, and the lower mold core of the plastic pallet molding die structure of this application; Figure 5 yes Figure 4 A magnified view of point A; Figure 6 This is a bottom structural diagram of the upper mold base of the plastic pallet molding die structure of this application; Figure 7 This is a bottom structural diagram of the upper mold core of the plastic pallet molding die structure of this application; Figure 8 yes Figure 7 A magnified view of point B; Figure 9 This is a front view of the plastic pallet molding die structure of this application; Figure 10 yes Figure 9 AA cross-section view; Figure 11 yes Figure 9 BB cross-section; Figure 12 yes Figure 11 A magnified view of point C; Figure 13 This is another embodiment of the plastic pallet molding die structure of this application. Figure 12 A magnified view of the location; Figure 14 This is an exploded view of the upper mold core of another embodiment of the plastic pallet molding mold structure of this application.

[0028] Explanation of reference numerals in the attached drawings: 1. Mold body; 11. Upper mold cover plate; 12. Diverter plate; 13. Upper mold base; 131. Guide hole; 132. Recessed groove; 14. Lower mold base; 141. Guide post; 15. Support base; 16. Lower mold bottom plate; 17. Upper mold core; 171. Upper hole protrusion; 172. Embedded hole; 1721. Limiting groove; 173. Abutting insert; 1731. Limiting part; 174. Upper air supply channel; 175. Slider; 1751. Abutting part; 1752. Top. 1753, Guide slope; 176, Slider drive; 18, Lower mold core; 181, Lower forming protrusion; 182, Through hole; 183, Lower air supply channel; 19, Molding cavity; 1a, Exhaust gap; 2, Injection mechanism; 21, Sprue cup; 22, Runner; 23, Injection tube; 3, Cooling mechanism; 31, Cooling water pipe; 4, Ejection mechanism; 41, Fixing plate; 42, Ejector rod; 43, Spring return structure; 5, Molded product; a, Step groove; b, Pressure relief hole. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1-14 This application will be described in further detail.

[0030] This application provides a plastic pallet forming mold structure, referring to... Figure 1 and Figure 2 The mold includes a mold body 1 and an injection mechanism 2, a cooling mechanism 3 and an ejection mechanism 4 disposed inside the mold body 1. The injection mechanism 2 is used to deliver molten injection liquid, the cooling mechanism 3 is used to cool the product so that it can be quickly solidified and molded, and after the mold is opened, the ejection mechanism 4 is used to eject the molded product from the mold body 1.

[0031] Reference Figure 1 and Figure 3The mold body 1 is provided with an upper mold cover plate 11, a flow divider plate 12, an upper mold base 13, a lower mold base 14, a support base 15, and a lower mold bottom plate 16, arranged sequentially from top to bottom. The upper mold cover plate 11, the flow divider plate 12, and the upper mold base 13 are fixedly connected by bolts and other connecting parts to form a stable upper mold structure. The lower mold base 14, the support base 15, and the lower mold bottom plate 16 are fixedly connected by bolts and other connecting parts to form a stable lower mold structure. Guide holes 131 are provided at the four corners of the lower surface of the upper mold base 13, and guide posts 141 are provided at the four corners of the upper surface of the lower mold base 14. The guide posts 141 and the guide holes 131 are arranged one-to-one to ensure the stability of the mold during the mold closing and opening process. Furthermore, the upper mold base 13 is detachably provided with an upper mold core 17 at its bottom via fastening bolts, and the lower mold base 14 is detachably provided with a lower mold core 18 at its top via fastening bolts. The upper mold core 17 and the lower mold core 18 are closed to form a molding cavity 19. This structure allows the mold to form a complete injection space, providing a foundation for the molding of plastic trays.

[0032] Reference Figure 3 , Figure 4 and Figure 5 Specifically, in this embodiment, the upper mold core 17 is provided with an upper perforation protrusion 171, an insert 172, and an abutment block 173. The upper perforation protrusion 171 is located on the lower surface of the upper mold core 17 and is protruding in shape. Its shape can be designed according to the shape of the through hole of the plastic tray, such as round or square. In this embodiment, the upper mold core 17 has a longitudinally arranged insert 172 in the middle, which penetrates the thickness of the upper mold core 17. The thickness of the abutment block 173 is greater than the thickness of the lower mold core 18. The abutment block 173 is movably inserted into the insert 172 from top to bottom and abuts against the wall of the insert 172. The outer wall of the abutment block 173 is sealed and fitted with the wall of the insert 172. The shape of the abutment block 173 is adapted to the insert 172 and is generally cylindrical. Its material can be stainless steel or the like, which has good strength and corrosion resistance. The bottom of the abutment insert 173 is provided with an upper hole protrusion 171. The upper hole protrusion 171 at the bottom of the abutment insert 173 can form a hole structure by injection molding when it fits against the upper surface of the lower mold core 18.

[0033] Specifically, the top edge of the abutment block 173 has a horizontally extending limiting portion 1731, and the wall of the recess 172 has a horizontally extending limiting groove 1721 for the limiting portion 1731 to abut longitudinally. The limiting portion 1731 and the limiting groove 1721 can limit the range of motion of the abutment block 173, so that the abutment block 173 can be inserted into the recess 172 from above. When the limiting portion 1731 abuts against the bottom of the limiting groove 1721, the abutment block 173 cannot continue to move downward, preventing the abutment block 173 from dislodging downward from the recess 172 and ensuring the normal operation of the abutment block 173.

[0034] Reference Figure 6, Figure 7 and Figure 8 Specifically, the upper surface of the lower mold core 18 is provided with a lower hole-forming protrusion 181, whose structure and function are similar to those of the upper hole-forming protrusion 171, also for forming hole structures on the plastic tray. The shape and material selection of the lower hole-forming protrusion 181 can also refer to those of the upper hole-forming protrusion 171. In the mold-closed state, the upper hole-forming protrusion 171 is attached to the upper surface of the lower mold core 18, and the lower hole-forming protrusion 181 is attached to the lower surface of the upper mold core 17. Thus, after the injection molding liquid solidifies, hole structures can be formed at the positions where the upper hole-forming protrusion 171 is attached to the upper surface of the lower mold core 18 and the lower hole-forming protrusion 181 is attached to the lower surface of the upper mold core 17.

[0035] The upper hole-forming protrusion 171 and the lower hole-forming protrusion 181 can be circular, triangular, square, or other irregular shapes. For example, in this embodiment, the upper hole-forming protrusion 171 fits against the upper surface of the lower mold core 18 to form a square through hole in the molded product 5, and the lower hole-forming protrusion 181 fits against the lower surface of the upper mold core 17 to form a triangular through hole and a long strip through hole in the molded product 5.

[0036] Specifically, both the upper forming protrusion 171 and the lower forming protrusion 181 have annular stepped grooves a in their middle sections. The area of ​​stepped groove a is smaller than that of the upper forming protrusion 171 and the lower forming protrusion 181. A pressure relief hole b is provided at the bottom of stepped groove a, extending out of the mold body 1 and communicating with an external pressure regulating mechanism. The function of stepped groove a is to accommodate a certain amount of gas. By adjusting the air pressure of stepped groove a to be greater than the pressure of molding cavity 19 through the external pressure regulating mechanism, stepped groove a forms a pressure barrier, thereby preventing the injection molding liquid from flowing into the gap between the upper forming protrusion 171 and the lower mold core 18, and between the lower forming protrusion 181 and the upper mold core 17.

[0037] Reference Figure 7 Furthermore, the abutment insert 173 is longitudinally provided with a pressure relief hole b that penetrates its thickness, and the lower surface of the upper mold base 13 is recessed with a relief groove 132 corresponding to the position of the abutment insert 173. The function of the relief groove 132 is to provide a certain amount of movement space for the abutment insert 173, so as to ensure that the abutment insert 173 can work normally when the mold is closed, so that the upper hole protrusion 171 and the upper surface of the lower mold core 18 remain in contact during the injection molding process.

[0038] Reference Figure 3Furthermore, an upper air supply channel 174 is provided on the outer surface of the upper mold core 17. All pressure relief holes b of the upper mold core 17 converge into the upper air supply channel 174. The upper air supply channel 174 is sealed between the upper mold core 17 and the upper mold base 13, and its air outlet extends out of the outer surface of the upper mold core 17. A lower air supply channel 183 is provided on the outer surface of the lower mold core 18. All pressure relief holes b of the lower mold core 18 converge into the lower air supply channel 183. The lower air supply channel 183 is sealed between the lower mold core 18 and the lower mold base 14, and its air outlet extends out of the outer surface of the lower mold core 18. The air outlets of the upper air supply channel 174 and the lower air supply channel 183 are connected to an external pressure regulating mechanism for simultaneously or individually adjusting the pressure relief holes b of the upper mold core 17 and the lower mold core 18. The internal upper air supply channel 174 and lower air supply channel 183 form a clearance design with the cooling mechanism.

[0039] Reference Figure 9-12 When the upper mold core 17 and lower mold core 18 are closed, the bottom of the abutment block 173 is in contact with the upper surface of the lower mold core 18, and the top of the abutment block 173 is in contact with the bottom of the relief groove 132. At this time, the limiting part 1731 is not in contact with the limiting groove 1721, leaving room for the abutment block 173 to move downward. When the upper mold core 17 and lower mold core 18 are open, the upper mold core 17 moves upward, and the abutment block 173 can be held on the side of the lower mold core 18 by gravity and push the molded product 5 downward onto the lower mold core 18. After the limiting part 1731 of the abutment block 173 is in contact with the limiting groove 1721 of the hole wall of the insert 172, the upper mold core 17 can continue to move upward, which can drive the abutment block 173 to move upward synchronously. This structural design allows the abutment insert 173 to assist in ejecting the product during mold opening, preventing the product from easily moving with the upper mold core 17, while ensuring the sealing of the molding cavity 19 during mold closing.

[0040] Specifically, in this embodiment, the injection molding mechanism 2 is provided with an integrally formed sprue cup 21, a flow divider 22, and multiple injection tubes 23 from top to bottom. An injection port is provided in the middle of the upper mold cover plate 11, a flow divider plate 12 is provided with a flow divider channel, and injection channels are provided in the upper mold base 13 and upper mold core 17. The injection port, flow divider channel, injection channel, and molding cavity 19 are sequentially connected. The sprue cup 21 is embedded in the injection port of the upper mold cover plate 11, the flow divider 22 is embedded in the flow divider channel of the flow divider plate 12, and each injection tube 23 is embedded in the injection channel of the upper mold base 13, with its outlet extending downwards and penetrating the upper mold core 17 to communicate with the molding cavity 19. During injection molding, the molten injection liquid enters from the sprue cup 21, and is evenly distributed to each injection tube section 23 through the distribution section 22. Then, it flows into the molding cavity 19 through the outlet of the injection tube section 23. This structural design allows the injection liquid to smoothly enter the molding cavity 19 from the injection port and is evenly distributed within the molding cavity 19 through the distribution section 22 and the injection tube sections 23, ensuring the molding quality of the plastic tray. In this embodiment, there are four injection tube sections 23, and a cooling sleeve is fitted between the outer wall of the injection tube section 23 and the upper mold core 17. This prevents the high-temperature molten injection liquid from transferring too much heat to the upper mold core 17 through the injection tube section 23, affecting the lifespan of the upper mold core 17, and also reduces deformation at the gate of the molded product.

[0041] Specifically, the cooling mechanism 3 in this embodiment is a conventional setting for existing injection molds. It adopts a cooling water pipe system 31, which is provided in the upper mold base 13, lower mold base 14, and other parts of the mold body 1. The circulating coolant carries away the heat generated during the injection process, allowing the injection liquid in the molding cavity 19 to cool and solidify rapidly. The coolant flows in from the inlet of the cooling water pipe 31, absorbs heat through various parts of the mold, and flows out from the outlet, realizing heat exchange and ensuring that the temperature of the mold is within a suitable range, thereby improving injection efficiency and product quality.

[0042] Specifically, the ejection mechanism 4 in this embodiment is a conventional setting of existing injection molds, which includes a fixed plate 41, several ejector pins 42, an ejector pin drive component, and a spring return structure 43. The fixed plate 41 is slidably disposed in the support base 15. The lower mold core 18 has through holes 182 for the ejector pins 42 to pass through. Several ejector pins 42 are vertically fixed on the upper surface of the fixed plate 41. The top of the ejector pins 42 extends vertically upward and passes through the through holes 182 of the lower mold base 14 and the lower mold core 18, so that the upper surface of the ejector pins 42 is flush with the upper surface of the lower mold core 18. The ejector pin drive component drives the fixed plate 41 to move upward, so that each ejector pin ejects the molded product 5 upward. Downward, when the plastic tray is formed, the ejector pin drive component is activated, pushing the fixed plate 41 to move upward. The fixed plate 41 drives the ejector pins 42 to move upward, and the ejector pins 42 eject the molded plastic tray from the lower mold core 18, which facilitates subsequent processing and handling. A spring return structure 43 is provided between the fixed plate 41 and the lower mold base 14. When the fixed plate 41 is driven to move upward, causing the ejector pin to eject the molded product 5, the spring return structure 43 pushes the fixed plate 41 downward, causing the fixed plate 41 to return to its original position. The spring return structure 43 is a standard feature of injection molds, and its specific structure and working principle will not be described in detail here.

[0043] Specifically, the external pressure regulating mechanism consists of a guide pipe, a flow regulating valve, and an air supply assembly. One end of the guide pipe is sealed and connected to the outlets of the upper air supply channel 174 and the lower air supply channel 183, while the other end is connected to the air supply assembly. The flow regulating valve is located on the guide pipe to regulate the gas delivery flow rate of the air supply assembly. Through the pressure regulating mechanism, the air pressure within the stepped groove a can be precisely controlled, effectively preventing the injection molding liquid from flowing into the gap and reducing the scrap rate.

[0044] The implementation principle of this embodiment is as follows: The plastic tray molding mold structure is connected to the external pressure regulating mechanism through the stepped groove a and the pressure relief hole b, changing the pressure difference between the molding cavity 19 and the stepped groove a, so that the stepped groove a forms an air pressure barrier, effectively preventing the injection liquid from flowing into the above-mentioned gap, improving the injection accuracy, thereby avoiding flash at the product through-hole, reducing the scrap rate, improving product quality, and effectively solving the problem of insufficient fitting accuracy of existing molds causing injection liquid to flow into the gap and flash at the product through-hole. The movable abutment block 173 can assist in ejecting the product when the mold is opened, and at the same time ensure the sealing of the molding cavity 19 when the mold is closed. The injection mechanism 2 ensures that the injection liquid flows evenly into the molding cavity 19, the cooling mechanism 3 makes the injection liquid cool and solidify quickly, and the ejection mechanism 4 facilitates the ejection of the molded product. This structural design improves the accuracy and quality of injection molded products, reduces the scrap rate, improves demolding reliability, and enhances the market competitiveness of the product.

[0045] Reference Figure 13A preferred embodiment is provided, which differs from the above embodiment in that: in embodiment 1, there is an unexpected situation where the abutment block 173 cannot remain on the lower mold core 18 side due to gravity. Therefore, in order to avoid this unexpected situation, this embodiment has a slider 175 and a slider drive 176 slidably disposed inside the upper mold core 17. The slider 175 is located in the relief groove 132. The slider 175 includes an integrally formed abutment part 1751 and an ejector part 1752. The tops of the abutment part 1751 and the ejector part 1752 abut against the bottom of the relief groove 132. The abutment part 1751 is rectangular, and its top abuts against the bottom of the relief groove 132, while its bottom abuts against the bottom of the relief groove 132. The top of the abutment block 173 abuts against the abutment, and the ejector part 1752 is wedge-shaped. The lower surface of the ejector part 1752 is provided with a guide slope 1753. The guide slope 1753 and the lower surface of the abutment part 1751 are connected in an arc transition. The guide slope 1753 is inclined upward towards the lower surface of the abutment part 1751. The slider drive 176 is a combination of a cylinder (not shown in the figure) and a push rod. The cylinder is fixedly set on the outer wall of the upper mold base 13 by a support structure and bolts. The output end of the cylinder is fixedly connected to the push rod. The push rod extends into the interior of the upper mold base 13 and is fixedly connected to the slider 175 to drive the slider 175 to slide horizontally along the bottom of the relief groove 132 so that the guide slope 1753 can push the abutment block 173 downward.

[0046] The implementation principle of this embodiment is as follows: by setting up the slider 175 and the slider drive component 176, the movement of the abutment block 173 can be controlled more flexibly. The guide slope 1753 of the slider 175 can push the abutment block 173 downwards when the slider 175 slides horizontally, thereby assisting in the ejection of the molded product 5. This structural design improves the ejection efficiency and reliability of the mold, further enhancing production efficiency and product quality.

[0047] Reference Figure 14 A preferred embodiment is provided, which differs from the above embodiments in that: both the upper mold core 17 and the lower mold core 18 are split mold core structures formed by splicing multiple modules along the horizontal direction, and each module can be disassembled and set individually. Several venting gaps 1a are provided between adjacent modules, each venting gap 1a extends upward beyond the upper surface of the module, and each venting gap 1a extends downward and does not communicate with the molding cavity 19.

[0048] The implementation principle of this embodiment is as follows: A split mold core structure is adopted, which facilitates mold manufacturing, maintenance, and replacement. The venting gap 1a between the modules provides a certain degree of buffering and venting, which is beneficial for the flow and molding of the injection molding liquid. Simultaneously, the venting gap 1a is not connected to the molding cavity 19, avoiding flash caused by injection molding liquid flowing into the gap and improving product quality.

[0049] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A plastic pallet molding mold structure, comprising a mold body (1), an injection molding mechanism (2), a cooling mechanism (3), and an ejection mechanism (4), wherein the mold body (1) is provided with an upper mold cover plate (11), a flow divider plate (12), an upper mold base (13), a lower mold base (14), a support base (15), and a lower mold bottom plate (16) from top to bottom, characterized in that, The upper mold base (13) is provided with an upper mold core (17) at its bottom, and the lower mold base (14) is provided with a lower mold core (18) at its top. The upper mold core (17) and the lower mold core (18) are closed to form a molding cavity (19). The lower surface of the upper mold core (17) is provided with an upper forming hole protrusion (171), and the upper surface of the lower mold core (18) is provided with a lower forming hole protrusion (181). In the closed state, the upper forming hole protrusion (171) and the upper surface of the lower mold core (18) are closed. The lower hole-forming protrusion (181) is fitted to the lower surface of the upper mold core (17); both the upper hole-forming protrusion (171) and the lower hole-forming protrusion (181) are provided with a stepped groove (a) in the middle, and a pressure relief hole (b) is provided at the bottom of the stepped groove (a), and the pressure relief hole (b) extends out of the mold body (1) and communicates with the external pressure adjustment mechanism; the upper mold core (17) is provided with a longitudinally penetrating hole corresponding to the position of the upper hole-forming protrusion (171). (172) An abutment block (173) that can move longitudinally against the wall of the recess (172) is sealed and embedded in the recess (172). A relief groove (132) is recessed on the lower surface of the upper mold base (13) corresponding to the position of the abutment block (173). In the mold closed state, the bottom of the abutment block (173) is in contact with the upper surface of the lower mold core (18), and the top of the abutment block (173) abuts against the bottom of the relief groove (132). The abutting insert (173) does not abut against the wall of the recess (172); in the mold-open state, the upper mold core (17) moves upward, and the abutting insert (173) can remain on the side of the lower mold core (18) under the action of gravity and push the molded product (5) downward onto the lower mold core (18) until the abutting insert (173) abuts against the wall of the recess (172), and then the upper mold core (17) drives the abutting insert (173) to move upward synchronously.

2. The plastic pallet forming mold structure according to claim 1, characterized in that, The top edge of the abutting insert (173) extends horizontally to form a limiting portion (1731), and the wall of the insert (172) extends horizontally to form a limiting groove (1721) for the limiting portion (1731) to abut longitudinally.

3. The plastic pallet forming mold structure according to claim 2, characterized in that, The thickness of the abutment insert (173) is greater than the thickness of the lower mold core (18).

4. The plastic pallet forming mold structure according to claim 2, characterized in that, The abutment insert (173) is longitudinally provided with the pressure relief hole (b) extending through its thickness.

5. The plastic pallet forming mold structure according to claim 2, characterized in that, The upper mold core (17) is internally equipped with a slider (175) and a slider drive (176). The slider (175) is located within the recessed groove (132). The slider (175) includes an integrally formed abutment part (1751) and an ejector part (1752). The abutment part (1751) is rectangular, with its top abutting against the bottom of the recessed groove (132) and its bottom abutting against the top of the abutment insert (173). The ejector part (1752) is wedge-shaped. 52) A guide slope (1753) is provided on the lower surface. The guide slope (1753) is connected to the lower surface of the abutment part (1751) in an arc transition. The guide slope (1753) is inclined upward towards the lower surface of the abutment part (1751). The slider drive (176) is fixedly provided on the outer wall of the upper mold base (13). Its output end extends into the interior of the upper mold base (13) to drive the slider (175) to slide horizontally so that the guide slope (1753) pushes the abutment block (173) downward.

6. The plastic pallet forming mold structure according to claim 1, characterized in that, All the pressure relief holes (b) of the upper mold core (17) converge into the upper air supply channel (174), which is sealed between the upper mold core (17) and the upper mold base (13) and its outlet extends out of the outer surface of the upper mold core (17); all the pressure relief holes (b) of the lower mold core (18) converge into the lower air supply channel (183), which is sealed between the lower mold core (18) and the lower mold base (14) and its outlet extends out of the outer surface of the lower mold core (18); both the upper air supply channel (174) and the lower air supply channel (183) are sealed and connected to an external pressure regulating mechanism.

7. The plastic pallet forming mold structure according to claim 1, characterized in that, Both the upper mold core (17) and the lower mold core (18) are split mold core structures formed by splicing multiple modules along the horizontal direction, and each module can be disassembled and set separately.

8. The plastic pallet forming mold structure according to claim 7, characterized in that, Several gaps are provided between adjacent modules, each gap extending upward beyond the upper surface of the module, and each gap extending downward without communicating with the molding cavity (19).

9. The plastic pallet forming mold structure according to claim 1, characterized in that, The upper mold cover plate (11) has an injection port in the middle, the flow divider plate (12) has a flow divider channel, the upper mold base (13) and the upper mold core (17) have injection channels, the injection port, the flow divider channel, the injection channel and the molding cavity (19) are connected in sequence, the injection mechanism (2) is provided with an integrally formed sprue cup (21), a flow divider part (22) and a plurality of injection tube parts (23) from top to bottom, the sprue cup (21) is embedded in the injection port of the upper mold cover plate (11), the flow divider part (22) is embedded in the flow divider channel of the flow divider plate (12), and each of the injection tube parts (23) is embedded in the injection channel of the upper mold base (13), and its outlet extends downward and penetrates the upper mold core (17).

10. The plastic pallet forming mold structure according to claim 1, characterized in that, The ejection mechanism (4) includes a fixed plate (41), a plurality of ejector rods (42) and an ejector rod drive member. The fixed plate (41) is slidably disposed in the support base (15). A plurality of ejector rods (42) are vertically fixed on the upper surface of the fixed plate (41). The top of the ejector rods (42) extends vertically upward and penetrates the lower mold base (14) and the lower mold core (18). The ejector rod drive member drives the fixed plate (41) to move upward so that each ejector rod (42) ejects the molded product (5) upward.

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