A thermoforming mold with replaceable forming mold

Abstract

A replaceable hot forming die includes an upper die and a lower die; the upper die includes an upper die plate and an upper shear die; the lower die includes a lower die plate, a lower die body, a lower shear die, a forming die and an ejection rod mounting plate, the forming die includes a side die and a movable bottom die, the side die is detachably mounted on the lower die body, the side die has at least one forming unit, the movable bottom die is composed of at least one movable bottom die unit, each movable bottom die unit is connected to the ejection rod mounting plate through at least one ejection rod, characterized in that: the lower die further includes an ejection rod tube positive plate, the ejection rod tube positive plate is detachably mounted on the lower die plate, the ejection rod tube positive plate is provided with at least one ejection rod guide hole with an up-down direction, and the ejection rod is located in the corresponding ejection rod guide hole; the lower die plate is provided with a hollow part for each ejection rod to pass through. The utility model can be locally modified to make the hot forming die suitable for the production of another plastic container, thereby reducing the equipment cost.

Description

Technical Field

[0001] This utility model relates to thermoforming equipment, and more specifically, to a thermoforming mold with a replaceable forming mold. Background Technology

[0002] An existing thermoforming mold for manufacturing plastic containers (such as plastic cups, plastic boxes, plastic basins, etc.) can complete molding and shearing operations. This thermoforming mold includes an upper mold and a lower mold; the upper mold includes an upper template and an upper shearing die, the upper shearing die is installed on the upper template, and the upper shearing die has a cavity (usually the inner edge of the lower end of the upper shearing die is the upper shearing blade); the lower mold includes a lower template, a lower mold body, a lower shearing die, and a molding die, the lower mold body is installed on the lower template and is located above the lower template, the lower shearing die is installed on the lower mold body and is located above the lower mold body (usually the outer edge of the upper end of the lower shearing die is the lower shearing blade, the lower shearing blade matches the upper shearing blade), and the molding die is installed on the lower mold body and is located inside the lower shearing die. The aforementioned lower mold typically also includes an ejector rod. The forming mold includes a side mold and a movable bottom mold. The side mold is mounted on the lower mold body and located inside the lower shearing mold. The movable bottom mold is located inside the side mold and is connected to the upper end of the ejector rod. The lower end of the ejector rod extends below the lower mold plate and is connected to the ejector rod mounting plate. The aforementioned side mold is used to form the side walls and edges of the plastic container, and the movable bottom mold is used to form the bottom of the plastic container.

[0003] When making plastic containers, the plastic sheet is first heated to reach the molding temperature. The heated plastic sheet passes through the molding area, where the thermoforming mold closes, and the plastic sheet is pressed tightly against the molding mold through positive pressure thermoforming (or negative pressure thermoforming). After molding, the plastic sheet is sheared by the upper shearing blade of the upper shearing die and the lower shearing blade of the lower shearing die, cutting the plastic container out of the plastic sheet to obtain a single plastic container. Then, the ejector rod mounting plate drives the ejector rod and the movable bottom mold to rise relative to the lower template, ejecting the plastic container from the molding mold and detaching the plastic container from the molding mold.

[0004] When a plastic container is divided into multiple container units by partition walls, the side mold is equipped with partitions that divide the side mold into multiple forming units. The partitions are used to form each partition wall. The movable bottom mold is usually composed of multiple corresponding movable bottom mold units. The number of movable bottom mold units is usually the same as the number of forming units and they correspond one-to-one. The movable bottom mold units are located inside the corresponding forming units and are used to form the bottom of the corresponding container units. Each movable bottom mold unit is connected to the ejector rod mounting plate through at least one ejector rod (the movable bottom mold unit is connected to the upper end of the corresponding ejector rod, and the lower end of each ejector rod extends to the bottom of the lower mold plate and is connected to the ejector rod mounting plate). The ejector rod mounting plate synchronously controls the lifting and lowering of each movable bottom mold unit.

[0005] The aforementioned thermoforming mold can usually only be used to produce one type of plastic container. When it is necessary to produce another type of plastic container, a new thermoforming mold needs to be made, the original thermoforming mold is removed from the thermoforming machine, and the new thermoforming mold is installed on the thermoforming machine.

[0006] Currently, some plastic container manufacturers produce a series of plastic containers (such as plastic lunch boxes) with identical outer contours and dimensions, but differences in the number, size, and position of the container units. Therefore, the thermoforming molds used contain identical components such as the upper mold plate, upper shear die, lower mold body, and lower shear die, but differ in the number and / or arrangement of the molding units, i.e., the molding die (side mold and movable bottom mold), ejector rods, etc. In this situation, when producing a different type of plastic container, replacing the entire thermoforming mold would significantly increase equipment costs. Therefore, it is necessary to find ways to partially modify the thermoforming mold to suit the production of a different type of plastic container, thereby reducing equipment costs. Utility Model Content

[0007] The technical problem this utility model aims to solve is to provide a replaceable forming die for thermoforming. This die allows for the replacement of the forming die and ejector pins when the number and / or arrangement of forming units changes, eliminating the need to replace the upper mold plate, upper shear die, lower mold plate, lower mold body, and lower shear die, thereby reducing equipment costs. The adopted technical solution is as follows:

[0008] A thermoforming mold with replaceable forming molds includes an upper mold and a lower mold. The upper mold includes an upper template and an upper shearing mold, the upper shearing mold being mounted on the upper template and having a cavity. The lower mold includes a lower template, a lower mold body, a lower shearing mold, a forming mold, and an ejector rod mounting plate. The lower mold body is mounted on and above the lower template, the lower shearing mold is mounted on and above the lower mold body, and the ejector rod mounting plate is located below the lower template. The forming mold includes a side mold and a movable bottom mold. The side mold is detachably mounted on the lower mold body and located inside the lower shearing mold. The device has at least one molding unit, and the movable bottom mold is composed of at least one movable bottom mold unit. Each movable bottom mold unit is connected to the ejector rod mounting plate through at least one ejector rod. The device is characterized in that: the lower mold also includes an ejector rod tube plate, which is detachably mounted on the lower template. The ejector rod tube plate is provided with at least one ejector rod guide hole running vertically. The number of ejector rod guide holes is the same as the number of ejector rods and they correspond one-to-one. The ejector rods are located in the corresponding ejector rod guide holes. The lower template is provided with a hollow part for each ejector rod to pass through.

[0009] When the above-mentioned thermoforming mold is used to make plastic containers, after molding and shearing are completed, the ejector rod mounting plate drives each ejector rod and each movable bottom mold unit to rise relative to the lower template, ejecting the plastic container from the molding mold and causing the plastic container to detach from the molding mold.

[0010] The aforementioned thermoforming mold can be used to produce various plastic containers with consistent outer shape and dimensions. The mold can be equipped with multiple molding die assemblies (each assembly includes a molding die, ejector rod, ejector rod tube plate, and ejector rod mounting plate), with each assembly corresponding to a specific type of plastic container. To produce a particular plastic container, simply install the corresponding molding die assembly onto the lower mold plate and lower mold body (if other molding die assemblies were previously installed on the lower mold plate and lower mold body, these must be removed first). This partial installation and removal of the thermoforming mold allows for quick and convenient modification to produce the desired plastic container.

[0011] The first method for assembling and disassembling the molding die assembly is as follows: When installing the molding die assembly, install the side mold on the lower die body, align and install the ejector rod tube plate on the lower template, and then pass each movable bottom die unit and ejector rod through the cutout on the lower template from bottom to top. Then, calibrate the position of each movable bottom die unit. When disassembling the molding die assembly, remove the ejector rod tube plate from the lower template, and then pass each movable bottom die unit and ejector rod through the cutout on the lower template from top to bottom. The ejector rod tube plate, ejector rod mounting plate, and each movable bottom die unit and ejector rod can then be removed together. Finally, remove the side mold from the lower die body. This assembly and disassembly method is relatively quick and time-saving, significantly reducing operation time.

[0012] In addition, when the movable bottom mold unit is too large to pass through the cutout, the second method for assembling and disassembling the molding mold assembly is used: When installing the molding mold assembly, install the side mold on the lower mold body, align and install the ejector rod tube plate on the lower template, and then allow each ejector rod to pass through the cutout on the lower template from bottom to top. Then install each movable bottom mold unit and calibrate its position. When removing the molding mold assembly, remove each movable bottom mold unit, remove the ejector rod tube plate from the lower template, and then allow each ejector rod to pass through the cutout on the lower template from top to bottom. Remove the ejector rod tube plate, ejector rod mounting plate, each movable bottom mold unit, and each ejector rod together, and then remove the side mold from the lower mold body. This method requires more time compared to the first method because it involves disassembling and installing the movable bottom mold unit.

[0013] In a preferred embodiment, the aforementioned hollow portion is a large through hole, and all the ejector rods are located within this large through hole.

[0014] In another preferred embodiment, the aforementioned hollow portion includes multiple ejector rod through holes. The position, size, and number of ejector rod through holes on the lower template can be set according to the position and size of the ejector rods in various molding die components corresponding to the series of plastic containers, and should meet the requirement that each ejector rod can pass through. For each ejector rod in various molding die components, there must be an ejector rod through hole on the lower template for it to pass through. Specifically, for a certain molding die component, the following situations may occur: (1) the number of ejector rods and ejector rod through holes are the same and correspond one-to-one; or (2) some ejector rod through holes do not contain ejector rods (for example, the number of ejector rod through holes is greater than the number of ejector rods, some of which do not contain ejector rods, and the remaining ejector rod through holes each contain one ejector rod); or (3) when the size of a certain ejector rod through hole is large, there can be multiple ejector rods in that ejector rod through hole, that is, multiple ejector rods share one ejector rod through hole.

[0015] In a more preferred embodiment, the orthographic projection of all movable bottom mold units in the above-mentioned molding mold onto the lower template is within the range of the hollow portion, so that the molding mold assembly can be loaded and unloaded using the first loading and unloading method.

[0016] Typically, the number of movable bottom mold units is the same as the number of molding units, and they correspond one-to-one. The movable bottom mold units are located inside the corresponding molding units. When the molding unit is large, one molding unit can correspond to multiple movable bottom mold units.

[0017] Typically, the number of movable bottom mold units and ejector rods are the same and correspond one-to-one. However, if the movable bottom mold unit is large, one movable bottom mold unit can correspond to multiple ejector rods.

[0018] Typically, the connection between the movable bottom mold unit, the ejector rod, and the ejector rod mounting plate is as follows: the movable bottom mold unit is connected to the upper end of the corresponding ejector rod, and the lower end of each ejector rod extends below the lower mold plate and is connected to the ejector rod mounting plate.

[0019] When a plastic container is divided into multiple container units by partition walls, the aforementioned side mold is provided with partitions that divide the side mold into multiple molding units. The movable bottom mold includes multiple movable bottom mold units, and each molding unit corresponds to at least one movable bottom mold unit. The partitions are used to form the partition walls between the container units, and the movable bottom mold units are used to form the bottom of the corresponding container unit.

[0020] In a preferred embodiment, the ejector rod tube plate has at least one vertically oriented ejector rod guide sleeve. The number of ejector rod guide sleeves is the same as the number of ejector rods, and they correspond one-to-one. The ejector rod is located in the ejector rod guide sleeve and slides in cooperation with it. The inner hole of the ejector rod guide sleeve forms the ejector rod guide hole. When there are multiple ejector rods, the ejector rod tube plate has multiple ejector rod guide sleeves, and the number of ejector rods and ejector rod guide sleeves is the same, and they correspond one-to-one.

[0021] In the preferred embodiment, the aforementioned ejector tube plate is detachably mounted on the lower surface of the lower template.

[0022] In a more preferred embodiment, the lower surface of the lower template is provided with a downward-facing tube plate positioning groove. The shape and size of the tube plate positioning groove match the ejector rod tube plate, and the ejector rod tube plate is installed in the tube plate positioning groove. When the ejector rod tube plate is installed in the tube plate positioning groove, the upper surface of the ejector rod tube plate is in close contact with the bottom of the tube plate positioning groove, and the side surface of the ejector rod tube plate is in close contact with the groove wall. Preferably, the lower surface of the ejector rod tube plate is on the same plane as the lower surface of the lower template.

[0023] Typically, the ejector tube plate can be detachably installed on the lower template using multiple screws (such as countersunk screws). The lower template has multiple screw holes, and the ejector tube plate has corresponding through holes. When installing the ejector tube plate, the screws pass through the through holes and engage with the corresponding screw holes. After tightening the screws, the screw heads and the lower template together clamp the ejector tube plate. To remove the ejector tube plate, simply remove all the screws.

[0024] In a preferred embodiment, the upper mold further includes an upper mold body, which is mounted on and below the upper template, and the upper shearing mold is mounted on the upper mold body; the upper mold body has a cavity.

[0025] In the preferred embodiment, the upper mold further includes a stretching head, a stretching rod, a stretching rod mounting plate, and a stretching rod mounting plate lifting control mechanism. The stretching head is detachably connected to the lower end of the stretching rod. The stretching head is located in the cavity of the upper shearing mold. The upper end of the stretching rod is connected to the stretching rod mounting plate, and the stretching rod mounting plate is connected to the stretching rod mounting plate lifting control mechanism. The stretching head has at least one stretching unit, and the number of stretching units is the same as the number of forming units and they correspond one-to-one.

[0026] The thermoforming die can be equipped with multiple stretching heads. After replacing the above-mentioned forming die assembly, the corresponding stretching heads should be replaced as needed. The stretching head can be a single unit (i.e., only one stretching unit) or it can have multiple stretching units (when the forming die is divided into multiple forming units, the stretching head will have correspondingly multiple stretching units). Each stretching unit can be mounted on a stretching unit mounting plate. The stretching unit mounting plate is detachably connected to the lower end of the stretching rod. When the corresponding stretching head needs to be replaced, the stretching unit mounting plate and each stretching unit are replaced together.

[0027] In a preferred embodiment, the upper mold further includes a pressure ring, which is disposed within the cavity of the upper shearing die. The lower end face of the pressure ring matches and corresponds in position to the upper end face of the lower shearing die or forming die. With the pressure ring, the stretching head is located within the cavity of the pressure ring. The pressure ring can move up and down within the cavity of the upper shearing die, applying pressure to the plastic sheet to be formed. In one specific embodiment, a compression spring is installed between the pressure ring and the upper die plate. When the compression spring contracts, it allows the pressure ring to apply a certain pressure to the plastic sheet to be formed. In another specific embodiment, a sealing ring is provided on the outer side of the pressure ring, forming a pressure chamber between the upper end of the pressure ring and the inner wall of the cavity of the upper shearing die. Compressed gas can be introduced into the pressure chamber, allowing the pressure ring to apply a certain pressure to the plastic sheet to be formed. In another specific design, a compression spring is installed between the pressure ring and the upper template, and a sealing ring is provided on the outside of the pressure ring, so that the upper end of the pressure ring and the inner wall of the upper shearing die form a pressure chamber. The combination of compression spring and compressed gas is used to apply a certain pressure to the plastic sheet to be formed by the pressure ring.

[0028] In the preferred embodiment, the lower template is provided with vertically oriented guide posts, the upper ends of which are connected to the lower template. A guide sleeve is provided on the ejector rod mounting plate, and the guide posts are located within the guide sleeve. When the ejector rod mounting plate moves up and down relative to the lower template, the guide sleeve slides along the guide posts, guiding the ejector rod mounting plate and ejector rod to move up and down more smoothly.

[0029] In the preferred embodiment, the lower template is provided with a vertically oriented limiting shaft, and the ejector rod mounting plate is provided with a limiting through hole. The limiting shaft is located in the limiting through hole, and a lower limiting washer is installed at the lower end of the limiting shaft, positioned below the ejector rod mounting plate. During the descent of the ejector rod mounting plate, when the lower surface of the ejector rod mounting plate contacts the upper end face of the lower limiting washer, the ejector rod mounting plate stops descending.

[0030] In addition, to shorten the molding cycle, a circulating cooling water system is usually set up to cool the molding mold and allow the product to cool and solidify quickly.

[0031] Typically, the inner edge of the lower end of the upper shearing die is the upper shearing blade, and the outer edge of the upper end of the lower shearing die is the lower shearing blade, with the lower shearing blade matching the upper shearing blade.

[0032] During molding, the upper mold can be fixed on the frame, and the lower mold can be raised and lowered relative to the upper mold; alternatively, the lower mold can be fixed on the frame, and the upper mold can be raised and lowered relative to the lower mold.

[0033] This invention allows for the replacement of the molding mold, ejector rod, ejector rod tube plate, ejector rod mounting plate, etc., when the number and / or arrangement of the molding units change, without the need to replace the upper template, upper shearing mold, lower template, lower mold body, and lower shearing mold (i.e., the upper template, upper shearing mold, lower template, lower mold body, and lower shearing mold are universal). By partially modifying the thermoforming mold, it can be adapted to the production of another type of plastic container, thereby reducing equipment costs. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the preferred embodiment 1 of this utility model (mold closed, pre-stretched state);

[0035] Figure 2 yes Figure 1 A top view of the plastic container corresponding to the thermoforming mold shown;

[0036] Figure 3 yes Figure 1 Top view of the center ejector tube plate;

[0037] Figure 4 yes Figure 1 Top view of the lower middle template.

[0038] Figure 5 This is a schematic diagram of the structure of the preferred embodiment of the present invention after the molding die assembly has been replaced (molding closed, pre-stretched state).

[0039] Figure 6 yes Figure 5 A top view of the plastic container corresponding to the thermoforming mold shown;

[0040] Figure 7 yes Figure 5 Top view of the center ejector tube plate;

[0041] Figure 8 This is a schematic diagram of the lower template in the preferred embodiment 2 of this utility model, and a schematic diagram (top view) of the cooperation between each ejector rod and the hollow part.

[0042] Figure 9 This is a schematic diagram (top view) of the cooperation between each ejector rod and the hollow part after the molding mold assembly is replaced in the preferred embodiment 2 of this utility model. Detailed Implementation

[0043] Example 1, Reference Figure 1 and Figure 5 This thermoforming mold with interchangeable molding dies includes an upper mold 1 and a lower mold 2.

[0044] The upper mold 1 includes an upper template 11, an upper mold body 12, an upper shearing die 13, and a pressure ring 14; the upper mold body 12 is mounted on the upper template 11 and located below the upper template 11, and the upper mold body 12 has a cavity; the upper shearing die 13 is mounted on the upper mold body 12, the upper shearing die 13 has a cavity, and the pressure ring 14 is located in the cavity of the upper shearing die 13.

[0045] The upper mold also includes a stretching head 15, a stretching rod 16, a stretching rod mounting plate 17, and a stretching rod mounting plate lifting control mechanism. The stretching head 15 is detachably connected to the lower end of the stretching rod 16. The stretching head 15 is located in the cavity of the pressure ring 14. The upper end of the stretching rod 16 is connected to the stretching rod mounting plate 17, and the stretching rod mounting plate 17 is connected to the stretching rod mounting plate lifting control mechanism. The stretching head 15 has at least one stretching unit 151, and the number of stretching units 151 is the same as that of the forming units and they correspond one-to-one. The stretching head 15 may have only one stretching unit 151 or multiple stretching units 151 (when the forming mold is divided into multiple forming units, the stretching head has correspondingly multiple stretching units). In this embodiment, each stretching unit 151 is mounted on the stretching unit mounting plate 152 (the stretching unit mounting plate 152 and each stretching unit 151 constitute the stretching head 15). The stretching unit mounting plate 152 is detachably connected to the lower end of the stretching rod 16. When the corresponding stretching head 15 needs to be replaced, the stretching unit mounting plate 152 and each stretching unit 151 are replaced together.

[0046] The lifting control mechanism for the tension rod mounting plate can be mounted on the upper template 11; when the upper mold is fixed on the frame, the lifting control mechanism for the tension rod mounting plate can also be mounted on the frame. The lifting control mechanism for the tension rod mounting plate is used to drive the tension rod mounting plate 17 and the tension rod 16 to move up and down; driven by the tension rod 16, the tension head 15 can move up and down within the cavity of the upper mold body 12 and the cavity of the pressure ring 14. The lifting control mechanism for the tension rod mounting plate may include a tension cylinder, and the piston rod of the tension cylinder is connected to the tension rod mounting plate; the cylinder body of the tension cylinder can be mounted on the upper template; when the upper mold is fixed on the frame, the cylinder body of the tension cylinder can also be mounted on the frame.

[0047] The upper template 11 is provided with a vertically oriented tension rod guide sleeve 18. The tension rod 16 is located in the tension rod guide sleeve 18 and slides in cooperation with the tension rod guide sleeve 18. One tension head 15 can correspond to one tension rod 16, or multiple tension rods 16 (when the tension head 15 is large, multiple tension rods 16 can be used to make the lifting and lowering of the tension head 15 more stable); the number of tension rod guide sleeves 18 and tension rods 16 are the same and correspond one-to-one.

[0048] In this embodiment, a compression spring 19 is installed between the pressing ring 14 and the upper template 11. When the compression spring 19 contracts, it can apply a certain pressure to the plastic sheet to be formed by the pressing ring 14.

[0049] The lower mold 2 includes a lower template 21, a lower mold body 22, a lower shearing mold 23, a forming mold 24, an ejector rod mounting plate 25, and an ejector rod tube plate 26. The lower mold body 22 is mounted on and above the lower template 21. The lower shearing mold 23 is mounted on and above the lower mold body 22. The ejector rod mounting plate 25 is located below the lower template 21. The forming mold 24 includes a side mold 241 and a movable bottom mold 242. The side mold 241 is detachably mounted on the lower mold body 22 and is located inside the lower shearing mold 23. The side mold 241 has at least one forming unit 2411. The movable bottom mold 242 is composed of at least one movable bottom mold unit 2421. Each movable bottom mold unit 2421 is connected to the ejector rod mounting plate 25 via at least one ejector rod 27 (e.g., ...). Figure 1 In the thermoforming mold shown, each movable bottom mold unit 2421 is connected to the ejector rod mounting plate 25 via an ejector rod 27; Figure 5 In the thermoforming mold shown, the movable bottom mold unit 2421 on the left is connected to the ejector rod mounting plate 25 via two ejector rods 27, and the other two movable bottom mold units 2421 are each connected to the ejector rod mounting plate 25 via an ejector rod 27. The lower end face of the pressure ring 14 matches and corresponds to the upper end face of the lower shearing die 23. The lower template 21 is provided with a hollow portion 29 for each ejector rod 27 to pass through.

[0050] When the plastic container 3 is divided into multiple container units 31 by a partition wall, the side mold 241 is provided with a partition 243, which divides the side mold 241 into multiple molding units 2411 (e.g., Figure 1 The thermoforming mold shown has five forming units 2411, corresponding to Figure 2 The plastic container 3 shown has five storage units 31; Figure 5 The thermoforming mold shown has three forming units 2411, corresponding to Figure 6 The plastic container 3 shown has three container units 31, and the movable bottom mold 242 includes multiple movable bottom mold units 2421 (e.g., Figure 1 The thermoforming mold shown has five movable bottom mold units 2421; Figure 5 The thermoforming mold shown has three movable bottom mold units 2421), each molding unit 2411 corresponding to at least one movable bottom mold unit 2421 (e.g., Figure 1 In the thermoforming mold shown, each forming unit 2411 corresponds to a movable bottom mold unit 2421; Figure 5 In the thermoforming mold shown, each forming unit 2411 corresponds to a movable bottom mold unit 2421. The partition 243 is used as a partition wall between the forming container units, and the movable bottom mold unit 2421 is used to form the bottom of the corresponding container unit.

[0051] The ejector tube plate 26 is detachably mounted on the lower surface of the lower template 21. (Reference) Figure 3 and Figure 7 The ejector tube plate 26 is provided with at least one vertically oriented ejector rod guide sleeve 28. The number of ejector rod guide sleeves 28 is the same as the number of ejector rods 27, and they correspond one-to-one. The ejector rods 27 are located in the ejector rod guide sleeves 28 and slide in cooperation with the ejector rod guide sleeves 28. The inner hole of the ejector rod guide sleeve 28 forms the ejector rod guide hole (the ejector rod is located in the corresponding ejector rod guide hole). When there are multiple ejector rods (such as five or four), the ejector tube plate is provided with multiple (such as five or four) ejector rod guide sleeves, and the number of ejector rods and ejector rod guide sleeves is the same, and they correspond one-to-one.

[0052] In this embodiment, the lower surface of the lower template 21 is provided with a downward-facing tube plate positioning groove 210. The shape and size of the tube plate positioning groove 210 match the ejector rod tube plate 26, and the ejector rod tube plate 26 is installed in the tube plate positioning groove 210. When the ejector rod tube plate 26 is installed in the tube plate positioning groove 210, the upper surface of the ejector rod tube plate 26 is in close contact with the bottom of the tube plate positioning groove 210, and the side surface of the ejector rod tube plate 26 is in close contact with the wall of the tube plate positioning groove 210. The lower surface of the ejector rod tube plate 26 and the lower surface of the lower template 21 are on the same plane, or approximately on the same plane.

[0053] refer to Figure 4 In this embodiment, the hollow part 29 is a large through hole 291, and all the ejector rods 27 are located in the large through hole 291; the orthographic projection of all the movable bottom mold units 2421 in the molding mold 24 on the lower template 21 is within the range of the large through hole 291 (i.e., the hollow part).

[0054] The connection between the movable bottom mold unit, the ejector rod, and the ejector rod mounting plate is as follows: the movable bottom mold unit 2421 is connected to the upper end of the corresponding ejector rod 27, and the lower end of each ejector rod 27 extends to the bottom mold plate 21 and is connected to the ejector rod mounting plate 25.

[0055] The ejector tube plate 26 is detachably installed on the lower template 21 using multiple screws 211 (such as countersunk screws). The lower template 21 has multiple screw holes 212, and the ejector tube plate 26 has corresponding through holes 213. When installing the ejector tube plate 26, the screws 211 pass through the through holes 213 and engage with the corresponding screw holes 212. After tightening the screws 211, the head of the screws 211 and the lower template 21 together clamp the ejector tube plate 26. When it is necessary to remove the ejector tube plate 26, remove all the screws 211, and the ejector tube plate 26 can be removed.

[0056] The ejector rod mounting plate 25 is provided with a tube guide sleeve 214, and the lower template 21 is provided with a guide post 215 running vertically. The guide post 215 is located in the tube guide sleeve 214. When the ejector rod mounting plate 25 rises and falls relative to the lower template 21, the tube guide sleeve 214 slides along the guide post 215, which can guide the ejector rod mounting plate 25 and the ejector rod 27 to rise and fall more smoothly.

[0057] The lower template 21 has a vertically oriented limiting shaft 216, and the ejector rod mounting plate 25 has a limiting through hole 217. The limiting shaft 216 is located in the limiting through hole 217, and a lower limiting washer 218 is sleeved on the lower end of the limiting shaft 216, located below the ejector rod mounting plate 25. During the descent of the ejector rod mounting plate 25, when the lower surface of the ejector rod mounting plate 25 contacts the upper end surface of the lower limiting washer 218, the ejector rod mounting plate 25 stops descending. The lower limiting washer 218 acts as a buffer and can be made of rubber or polyurethane elastomer. A limiting nut 219 is installed at the lower end of the limiting shaft 216, and the limiting nut 219 supports the lower limiting washer 218.

[0058] In addition, to shorten the molding cycle, a circulating cooling water system is usually set up to cool the molding mold and allow the product to cool and solidify quickly.

[0059] The inner edge of the lower end of the upper shearing die 13 is the upper shearing blade, and the outer edge of the upper end of the lower shearing die 23 is the lower shearing blade. The lower shearing blade matches the upper shearing blade.

[0060] The working principle of this thermoforming mold is briefly described below:

[0061] During molding, the upper mold 1 is fixed on the frame, and the lower mold 2 moves up and down relative to the upper mold 1.

[0062] When making plastic products, the plastic sheet is first heated to reach the molding temperature. After the plastic sheet is heated, it passes through the molding area. At this time, the thermoforming mold closes and the compression spring 19 applies a downward pushing force to the pressure ring 14, so that the pressure ring 14 presses the sheet tightly on the upper end face of the lower shearing die 23.

[0063] Next, the tension rod mounting plate lifting control mechanism drives the tension rod mounting plate 17 to descend, and the tension rod mounting plate 17, tension rod 16, and tension head 15 descend together; the tension head 15 pre-stretches the plastic sheet.

[0064] Then, through positive or negative pressure thermoforming, the plastic sheet is pressed tightly against the forming mold to form the plastic sheet; after cooling, the formed sheet is set.

[0065] Next, the lower mold 2 rises further, and the lower shearing blade on the outer edge of the upper end of the lower shearing mold 23 cooperates with the upper shearing blade on the inner edge of the lower end of the upper shearing mold 13 to cut the shaped sheet and cut the plastic product out of the shaped sheet to obtain a single plastic product.

[0066] Subsequently, the tension rod mounting plate lifting control mechanism drives the tension rod mounting plate 17, tension rod 16, and tension head 15 to rise together, and the tension head 15 returns to the cavity of the upper shearing die 13.

[0067] Then the lower mold 2 descends, and the edge of the plastic product leaves the pressure ring 14; subsequently, the ejector rod mounting plate 25 and the ejector rod 27 rise, and the movable bottom mold 242 rises along with it and ejects the plastic product (each movable bottom mold unit 2421 rises synchronously), and the plastic product is demolded.

[0068] Then, air can be blown onto the plastic product to blow it away from the thermoforming mold, thus completing one thermoforming process. Subsequently, the ejector rod mounting plate 25 and ejector rod 27 descend and drive the movable bottom mold 242 to the required molding position (each movable bottom mold unit 2421 descends synchronously), preparing for the next thermoforming process.

[0069] This thermoforming mold can be used to produce various plastic containers with consistent outer shape and dimensions. The mold is equipped with multiple molding die assemblies (including a molding die 24, ejector rod 27, ejector rod tube plate 26, and ejector rod mounting plate 25) and corresponding multiple stretching heads 15. Each molding die assembly and corresponding stretching head 15 corresponds to one type of plastic container. When producing a specific type of plastic container, simply install the corresponding molding die assembly onto the lower mold plate 21 and lower mold body 22 (if other molding die assemblies were previously installed on the lower mold plate 21 and lower mold body 22, remove the original molding die assemblies first), and install the corresponding stretching head 15 onto the upper mold 1.

[0070] The assembly and disassembly method for the molding die assembly is as follows: When the molding die assembly needs to be installed, install the side mold 241 on the lower mold body 22, and align and install the ejector rod tube plate 26 on the lower template 21. Each movable bottom mold unit 2421 and each ejector rod 27 passes through the hollow part 29 on the lower template 21 from bottom to top. Then, calibrate the position of each movable bottom mold unit 2421, and install the lower limit washer 218 and limit nut 219 in place. When the molding die assembly needs to be disassembled... When removing the components, remove the ejector tube plate 26 from the lower template 21, and remove the lower limit washer 218 and limit nut 219. Then, allow each movable bottom mold unit 2421 and each ejector rod 27 to pass from top to bottom through the cutout 29 on the lower template 21. This allows the ejector tube plate 26, ejector rod mounting plate 25, and each movable bottom mold unit 2421 and each ejector rod 27 to be removed together. Then, remove the side mold 241 from the lower mold body 22. After replacing the molding die assembly, replace the corresponding stretching head 15 as needed.

[0071] Example 2, the difference between Example 2 and Example 1 is: (Refer to...) Figures 8-9 The hollow part 29 includes multiple (e.g., five) ejector rod through holes 292. The position, size and number of ejector rod through holes 292 on the lower template 21 are set according to the position and size of the ejector rods 27 in the various molding die components corresponding to the series of plastic containers, so as to meet the requirement that each ejector rod can pass through. For each ejector rod in various molding die components, there must be an ejector rod through hole on the lower template for it to pass through. Specifically, for a certain molding die component, the following situations may occur: (1) The number of ejector rods and ejector rod through holes are the same and correspond one-to-one (refer to Figure 8 (1) Five ejector rods 27 correspond one-to-one with five ejector rod through holes 292; or (2) some ejector rod through holes do not have ejector rods (see reference). Figure 9 (2) There are five ejector rod through holes 292 and four ejector rods 27. One of the ejector rod through holes 292 does not contain an ejector rod 27, while the other ejector rod through holes 292 each contain an ejector rod 27. (3) When the size of a certain ejector rod through hole is large, there can be multiple ejector rods in the ejector rod through hole, that is, multiple ejector rods share a single ejector rod through hole.

[0072] In this embodiment, the orthographic projections of all movable bottom mold units 2421 in the molding mold 24 onto the lower template 21 are all within the range of the hollowed-out portion 29. In specific design, Figure 8 The corresponding thermoforming mold includes five movable bottom mold units 2421. The number of movable bottom mold units 2421 is the same as the number of forming units 2411, and they correspond one-to-one. The movable bottom mold units 2421 are located inside the corresponding forming units 2411. (Reference) Figure 8 The orthographic projections of the five movable bottom mold units 2421 on the lower mold plate 21 are respectively within the range of the five ejector rod through holes 292, and can pass through the corresponding ejector rod through holes 292 respectively. Figure 9 The corresponding thermoforming mold includes four movable bottom mold units 2421 and three forming units 2411, with one forming unit 2411 corresponding to two movable bottom mold units 2421 (equivalent to...). Figure 5 In the thermoforming mold shown, the movable bottom mold unit 2421 on the left is divided into two smaller movable bottom mold units 2421; the other two forming units 2411 each correspond to one movable bottom mold unit 2421; Reference Figure 9 The orthographic projections of the four movable bottom mold units 2421 on the lower mold plate 21 are respectively within the range of the four corresponding ejector rod through holes 292, and can pass through the corresponding ejector rod through holes 292 respectively.

[0073] The remaining structures of Example 2 can be referred to Example 1.

Claims

1. A thermoforming mold with a replaceable forming mold, comprising an upper mold and a lower mold; the upper mold includes an upper template and an upper shearing mold, the upper shearing mold being mounted on the upper template and having a cavity; the lower mold includes a lower template, a lower mold body, a lower shearing mold, a forming mold, and an ejector rod mounting plate, the lower mold body being mounted on and above the lower template, the lower shearing mold being mounted on and above the lower mold body, the ejector rod mounting plate being below the lower template, the forming mold including a side mold and a movable bottom mold, the side mold being detachably mounted on the lower mold body and located inside the lower shearing mold, the side mold having at least one forming unit, the movable bottom mold consisting of at least one movable bottom mold unit, each movable bottom mold unit being connected to the ejector rod mounting plate via at least one ejector rod, characterized in that: The lower mold also includes an ejector rod tube plate, which is detachably installed on the lower mold plate. The ejector rod tube plate is provided with at least one ejector rod guide hole running vertically. The number of ejector rod guide holes is the same as the number of ejector rods and they correspond one-to-one. The ejector rods are located in the corresponding ejector rod guide holes. The lower mold plate is provided with a hollow part for each ejector rod to pass through.

2. The thermoforming mold with replaceable molding die according to claim 1, characterized in that: The hollowed-out section is a large through hole, and all the ejector rods are located in this large through hole.

3. The thermoforming mold with replaceable molding die according to claim 1, characterized in that: The hollowed-out section includes multiple through holes for ejector rods.

4. The thermoforming mold with replaceable molding die according to any one of claims 1-3, characterized in that: The orthographic projection of all movable bottom mold units in the molding die onto the lower template is within the range of the hollowed-out portion.

5. The thermoforming mold with replaceable molding die according to any one of claims 1-3, characterized in that: The side mold is provided with a partition plate, which divides the side mold into multiple molding units. The movable bottom mold includes multiple movable bottom mold units, and each molding unit corresponds to at least one movable bottom mold unit.

6. The thermoforming mold with interchangeable molding dies according to any one of claims 1-3, characterized in that: The ejector rod tube plate is provided with at least one ejector rod guide sleeve running vertically. The number of ejector rod guide sleeves is the same as the number of ejector rods and they correspond one-to-one. The ejector rod is located in the ejector rod guide sleeve and slides in cooperation with the ejector rod guide sleeve. The inner hole of the ejector rod guide sleeve constitutes the ejector rod guide hole.

7. The thermoforming mold with interchangeable molding dies according to any one of claims 1-3, characterized in that: The ejector tube plate can be detachably installed on the lower surface of the lower template.

8. The thermoforming mold with replaceable molding die according to claim 7, characterized in that: The lower surface of the lower template is provided with a tube plate positioning groove with the slot facing downward. The shape and size of the tube plate positioning groove match the ejector rod tube plate, and the ejector rod tube plate is installed in the tube plate positioning groove.

9. The thermoforming mold with interchangeable molding dies according to any one of claims 1-3, characterized in that: The upper mold also includes a stretching head, a stretching rod, a stretching rod mounting plate, and a stretching rod mounting plate lifting control mechanism. The stretching head is detachably connected to the lower end of the stretching rod. The stretching head is located in the cavity of the upper shearing mold. The upper end of the stretching rod is connected to the stretching rod mounting plate, and the stretching rod mounting plate is connected to the stretching rod mounting plate lifting control mechanism. The stretching head has at least one stretching unit, and the number of stretching units is the same as the number of forming units and they correspond one-to-one.

10. The thermoforming mold with interchangeable molding dies according to any one of claims 1-3, characterized in that: The upper mold also includes an upper mold body, which is mounted on and below the upper template, and the upper shearing mold is mounted on the upper mold body; the upper mold body has a cavity; The upper mold also includes a pressure ring, which is located in the cavity of the upper shearing mold. The lower end face of the pressure ring matches and is positioned correspondingly to the upper end face of the lower shearing mold or the forming mold.

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