A thermoforming mold

Abstract

A thermoforming mold comprises an upper mold and a lower mold; the upper mold comprises an upper mold plate, an upper mold body, a stretching head, a stretching rod and a stretching rod mounting plate, the upper mold body is mounted on the upper mold plate, and the stretching head is in the cavity of the upper mold body; the lower mold comprises a lower mold plate, a lower mold body and a forming mold, the lower mold body is mounted on the lower mold plate, and the forming mold is mounted on the lower mold body; a stretching head water storage cavity is provided in the stretching head, and a stretching water inlet channel and a stretching water outlet channel are provided in the stretching rod, and the feature is that: a partition is provided in the stretching head water storage cavity, and the partition divides the stretching head water storage cavity into a water inlet side cavity and a water outlet side cavity, the bottom of the water inlet side cavity is connected with the bottom of the water outlet side cavity, the lower end of the stretching water inlet channel is connected with the top of the water inlet side cavity, and the lower end of the stretching water outlet channel is connected with the top of the water outlet side cavity. This thermoforming mold can effectively improve the heat exchange efficiency between the water in the stretching head water storage cavity and the stretching head during the production process, and quickly and fully realize the cooling or heating of the stretching head.

Description

Technical Field

[0001] The utility model relates to thermoforming equipment, in particular to a thermoforming mould. Background Art

[0002] The existing thermoforming molds for making plastic products (such as plastic cups, plastic boxes, plastic basins, plastic covers, etc.) usually include an upper mold and a lower mold; the upper mold usually includes an upper mold plate and an upper mold body, the upper mold body is installed on the upper mold plate, and the upper mold body has a cavity; the lower mold includes a lower mold plate and a molding mold, the molding mold is installed on the lower mold plate, and the molding mold has a molding cavity. The upper mold usually also includes a stretching head, a stretching rod and a stretching rod mounting plate, the lower end of the stretching rod is connected to the stretching head, the stretching head is in the cavity of the upper mold body, and the upper end of the stretching rod is connected to the stretching rod mounting plate. When the stretching head pre-stretches the heated plastic sheet, it is in close contact with the plastic sheet, and the heat on the plastic sheet is transferred to the stretching head. In this way, after a period of time, the temperature of the stretching head is too high. On the one hand, the high temperature will cause the stretching head to be damaged and shorten its service life. On the other hand, when the stretching head with too high temperature contacts the plastic sheet, it will cause the plastic sheet to adhere to the surface of the stretching head, making the surface of the plastic sheet rough and affecting the finish of the plastic container. In addition, at the beginning of production, due to the low temperature of the stretching head, the plastic sheet in contact with it is cooled and cannot be pre-stretched smoothly, resulting in waste and defective products.

[0003] In order to solve the above problems, the applicant's prior patent with authorization announcement number CN209888130U provides a thermoforming mold with controllable stretching head temperature, which includes an upper mold and a lower mold; the upper mold includes an upper mold plate, an upper mold body, a stretching head, a stretching rod, a stretching rod mounting plate and a stretching rod mounting plate lifting control mechanism, the upper mold body is installed on the upper mold plate, the upper mold body has a cavity, the lower end of the stretching rod is connected to the stretching head, the stretching head is in the cavity of the upper mold body, 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 lower mold includes a lower mold plate and a molding mold, the molding mold is installed on the lower mold plate, and the molding mold has a molding mold cavity; a stretching head water cavity is provided in the stretching head, a stretching water inlet channel and a stretching water outlet channel are provided in the stretching rod, and the lower ends of the stretching water inlet channel and the lower ends of the stretching water outlet channel are both connected to the stretching head water cavity. When the above-mentioned thermoforming mold is used to make a plastic container, water of a certain temperature is introduced from the upper end of the stretching water inlet channel. When the water flows through the stretching head water chamber, it exchanges heat with the stretching head, and then flows out through the upper end of the stretching water outlet channel. At the beginning of production, the temperature of the stretching head is relatively low. At this time, water is first passed into the stretching head water chamber. The water flowing through the stretching head water chamber heats the stretching head, so that the stretching head is heated to a suitable temperature, and then the plastic sheet is pre-stretched and formed. This can avoid the stretching head temperature being too low and the plastic sheet cannot be pre-stretched smoothly, thereby reducing waste and defective products. As production continues, the heat on the plastic sheet is transferred to the stretching head, which will cause the stretching head to heat up. At this time, the water flowing through the stretching head water chamber can take away the heat from the stretching head, and then flows out through the upper end of the stretching water outlet channel, thereby cooling the stretching head to prevent the stretching head from being damaged due to excessive temperature. At the same time, since the stretching head is kept within a suitable temperature range, the plastic sheet is effectively prevented from adhering to the surface of the stretching head, which helps to increase the smoothness of the product (i.e., the plastic container).

[0004] However, in the above-mentioned thermoforming mold, the stretching head water chamber in the stretching head is an integral structure. The water flow rate is faster at the top of the stretching head water chamber between the lower end of the stretching water inlet channel and the lower end of the stretching water outlet channel, but the water flow rate is slower in other parts of the stretching head water chamber, and even a retention area will be formed in some areas on the periphery and bottom of the stretching head water chamber. The water in the retention area cannot be replaced in time, and the heat exchange efficiency between the water in the stretching head water chamber and the stretching head is low, making it difficult to quickly and fully realize the cooling or heating of the stretching head. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide a thermoforming mold, which can effectively improve the heat exchange efficiency between the water in the water chamber of the stretching head and the stretching head during the production process, and quickly and fully realize the cooling or heating of the stretching head. The adopted technical solution is as follows:

[0006] A thermoforming mold comprises an upper mold and a lower mold; the upper mold comprises an upper mold, an upper mold body, a stretching head, a stretching rod and a stretching rod mounting plate, the upper mold body is installed on the upper mold body, the upper mold body has a cavity, the lower end of the stretching rod is connected to the stretching head, the stretching head is in the cavity of the upper mold body, and the upper end of the stretching rod is connected to the stretching rod mounting plate; the lower mold comprises a lower mold body, a lower mold body and a forming mold, the lower mold body is installed on the lower mold body, the forming mold is installed on the lower mold body, and the forming mold has a forming mold cavity; a stretching head water cavity is provided in the stretching head, and a stretching water inlet channel and a stretching water outlet channel are provided in the stretching rod, and the characteristic is that: a partition is provided in the stretching head water cavity, the partition divides the stretching head water cavity into a water inlet side cavity and a water outlet side cavity, the bottom of the water inlet side cavity is connected to the bottom of the water outlet side cavity, the lower end of the stretching water inlet channel is connected to the top of the water inlet side cavity, and the lower end of the stretching water outlet channel is connected to the top of the water outlet side cavity.

[0007] The partition divides the water chamber of the stretching head into a water inlet side chamber and a water outlet side chamber, and the bottom of the water inlet side chamber is connected to the bottom of the water outlet side chamber, thereby forming a U-shaped cooling water channel in the stretching head. When the above-mentioned thermoforming mold is used to make a plastic container, water of a certain temperature is introduced from the upper end of the stretching water inlet channel, and the water flows in a U-shaped trajectory when passing through the water chamber of the stretching head, and then flows out through the upper end of the stretching water outlet channel. In this way, the water in the water chamber of the stretching head can be replaced in time, so that the water can quickly and fully exchange heat with the stretching head, and the cooling or heating of the stretching head can be quickly and fully realized.

[0008] Usually, the lower mold body has a forming mold cavity capable of accommodating a forming mold, and the forming mold is arranged in the forming mold cavity.

[0009] In the preferred embodiment, the stretching head comprises a stretching head body and a stretching head flange, a groove is provided on the top of the stretching head body, the stretching head flange is installed on the top of the stretching head body and covers the groove, the inner wall of the groove and the lower surface of the stretching head flange together form the stretching head water volume chamber, the lower end of the stretching rod is connected to the stretching head flange; there is a water-passing gap between the bottom of the partition and the bottom of the groove, and the bottom of the water inlet side cavity is connected to the bottom of the water outlet side cavity through the water-passing gap. The partition can be fixedly installed on the lower surface of the stretching head flange or the lower end of the stretching rod; or a slot can be provided on the opposite side walls of the groove, and the two side edges of the partition are respectively inserted into the slots on both sides.

[0010] The above-mentioned upper mold is usually also equipped with a stretching rod mounting plate lifting control mechanism, and the stretching rod mounting plate is connected to the stretching rod mounting plate lifting control mechanism. The above-mentioned stretching rod mounting plate lifting control mechanism can be arranged on the upper mold plate; when the upper mold is fixed on the frame, the stretching rod mounting plate lifting control mechanism can also be arranged on the frame. The stretching rod mounting plate lifting control mechanism is used to drive the stretching rod to move up and down; driven by the stretching rod, the stretching head can move up and down in the cavity of the upper mold body. The stretching rod mounting plate lifting control mechanism may include a stretching cylinder, and the stretching rod mounting plate is connected to the piston rod of the stretching cylinder; the cylinder body of the stretching cylinder can be installed on the upper mold plate; when the upper mold is fixed on the frame, the cylinder body of the stretching cylinder can also be installed on the frame.

[0011] In order to ensure smooth movement of the stretching head, a stretching rod guide sleeve extending up and down is preferably provided on the upper template, and the stretching rod is located in the stretching rod guide sleeve and is in sliding cooperation with the stretching rod guide sleeve.

[0012] In the preferred embodiment, the upper mold further comprises an upper shearing mold and a pressure ring, the upper shearing mold is mounted on the upper mold body, the upper shearing mold has a cavity, and the pressure ring is arranged in the cavity of the upper shearing mold; the lower mold further comprises a lower shearing mold, an ejector mounting plate, an ejector lifting drive mechanism and at least one ejector, the lower shearing mold is mounted on the lower mold body, the lower shearing mold is sleeved on the outside of the forming mold, the upper end face of the lower shearing mold matches the lower end face of the pressure ring and the position corresponds, the ejector mounting plate is arranged below the lower template, the lower end of each ejector is connected to the ejector mounting plate, and the ejector mounting plate is connected to the ejector lifting drive mechanism; the lower mold is provided with at least one ejector through hole running up and down, the ejector through hole connects the upper end face of the forming mold with the lower surface of the lower template, the ejector through hole is the same as the number of ejectors and corresponds one to one, and the ejector is arranged in the ejector through hole. By providing an ejector, an ejector mounting plate and an ejector lifting drive mechanism, the plastic product with a snap-fit ​​structure on the outer edge of the opening can be smoothly demolded. The function of the ejector lifting drive mechanism is: when demoulding, the ejector mounting plate and each ejector are driven to rise, so that the upper end of the ejector extends out of the upper end of the ejector through hole and pushes the outer edge of the opening of the plastic product, thereby separating the snap-fit ​​structure of the outer edge of the opening of the plastic product from the molding mold; after demoulding is completed, the ejector mounting plate and each ejector are driven to descend, so that the ejector returns to the position required for molding.

[0013] Usually, the inner edge of the lower end of the upper shearing die is the upper shearing blade; the outer edge of the upper end of the lower shearing die is the lower shearing blade, and the lower shearing blade matches the upper shearing blade. In this way, the thermoforming mold can complete the shearing action after completing the forming to obtain a single plastic product.

[0014] In the case of a press ring, the stretching head is located in the cavity of the press ring. The press ring can move up and down in the cavity of the upper shear die, and can apply pressure to the plastic sheet to be formed. In a specific embodiment, a compression spring is installed between the press ring and the upper die plate, and when the compression spring contracts, the press ring can apply a certain pressure to the plastic sheet to be formed.

[0015] In order to make the plastic product bear force evenly, the above-mentioned ejector through holes are provided with a plurality of ejectors, and the ejectors are provided with a plurality of ejectors accordingly. The position of each ejector through hole can be determined according to the specific shape of the upper end face of the forming mold (for example, when the upper end face of the forming mold is circular, each ejector through hole can be evenly distributed along its circumference; when the upper end face of the forming mold is polygonal, each ejector through hole can be arranged at each corner of the polygon). The cross-sectional shape and size of the above-mentioned ejector through hole are usually matched with the ejector, and the inner wall of the ejector through hole guides the lifting and lowering of the ejector.

[0016] In a more preferred embodiment, the ejector lifting and driving mechanism comprises an ejector lifting and driving cylinder, a cylinder body accommodating cavity is provided in the lower mold body, the cylinder body of the ejector lifting and driving cylinder is fixedly installed in the cylinder body accommodating cavity, the piston rod of the ejector lifting and driving cylinder faces downward and is connected to the ejector mounting plate; a piston rod guide sleeve is provided on the lower mold plate, and the piston rod of the ejector lifting and driving cylinder is located in the piston rod guide sleeve. The piston rod guide sleeve can guide the piston rod of the ejector lifting and driving cylinder to rise and fall smoothly.

[0017] In a more preferred embodiment, a guide column extending up and down is fixedly mounted on the lower template, and a guide hole for an ejector mounting plate is provided on the ejector mounting plate. The ejector mounting plate is sleeved on the guide column through the guide hole for the ejector mounting plate and is slidably matched with the guide column, so that the ejector mounting plate and the ejector can be lifted and lowered more smoothly.

[0018] In a more preferred embodiment, the lower mold further comprises an ejector rod and an ejector rod mounting plate, the molding die comprises a side mold and a movable bottom mold, the side mold is mounted on the lower mold body and is located inside the lower shear mold, the movable bottom mold is connected to the upper end of the ejector rod, and the lower end of the ejector rod extends below the lower mold plate and is connected to the ejector rod mounting plate. The ejector rod mounting plate is connected to an ejector rod lifting and driving mechanism. The side mold is used to mold the edge part or side wall of the plastic product; the movable bottom mold is used to mold the middle part or bottom of the plastic product. During demoulding, after the snap-fit ​​structure of the plastic product is separated from the molding die, the ejector rod rises and ejects the plastic product; or during demoulding, the ejector rod and the ejector pin rise at the same time and eject the plastic product together. In a further preferred embodiment, a tube positive guide sleeve is provided on the ejector rod mounting plate, and the guide column is in the tube positive guide sleeve. When the ejector rod mounting plate is lifted or lowered relative to the lower mold plate, the tube positive guide sleeve slides along the guide column, which can guide the ejector rod mounting plate and the ejector rod to lift or lower more smoothly.

[0019] In another more preferred embodiment, the lower mold further includes an ejector rod, and the molding mold includes a side mold and a movable bottom mold. The side mold is mounted on the lower mold body and is located on the inner side of the lower shear mold. The movable bottom mold is connected to the upper end of the ejector rod, and the lower end of the ejector rod extends below the lower mold and is connected to the ejector mounting plate. The side mold is used to mold the edge portion or side wall of the plastic product; the movable bottom mold is used to mold the middle portion or bottom of the plastic product. During demolding, driven by the ejector lifting drive mechanism, the ejector rod and the ejector rise simultaneously to eject the plastic product together. In a more preferred embodiment, a tube positive guide sleeve is provided on the ejector rod mounting plate, and the guide column is in the tube positive guide sleeve. When the ejector rod mounting plate is lifted or lowered relative to the lower mold, the tube positive guide sleeve slides along the guide column, which can guide the ejector rod mounting plate and the ejector rod to lift or lower more smoothly.

[0020] In a further preferred embodiment, the ejector rod is provided with an air inlet channel extending upward and downward, the lower end of the air inlet channel is the air inlet end, and the upper end is the air outlet end. The movable bottom mold is provided with at least one blowing hole, and each blowing hole is connected to the air outlet end of the air inlet channel. The air inlet end of the air inlet channel is connected to a gas supply device (such as a compressed gas source). After the mold is opened, the gas supply device supplies gas to the air inlet channel, and the gas is blown out from the blowing hole and blown toward the plastic product to assist demolding, which helps the plastic product to be demolded more smoothly. Preferably, the movable bottom mold is provided with multiple blowing holes.

[0021] Usually, the gas outlet of the gas supply device is connected to the gas inlet end of the gas inlet channel through a gas supply pipe, and a solenoid switch valve is provided on the gas supply pipe. When the solenoid switch valve is opened, the gas supply device supplies gas to the gas inlet channel through the gas supply pipe, and the gas is blown out from the blowing hole.

[0022] In a specific solution, a gas delivery channel is provided on the ejector rod mounting plate, an air inlet end of the air inlet channel in the ejector rod is connected to the gas delivery channel, an air inlet is provided on the gas delivery channel, and the air inlet is connected to the gas supply device.

[0023] In a further preferred embodiment, the ejector rod is provided with a cooling water inlet channel and a cooling water outlet channel extending upward and downward, the lower end of the cooling water inlet channel is the water inlet end and the upper end is the water outlet end, the upper end of the cooling water outlet channel is the water inlet end and the lower end is the water outlet end; the movable bottom mold is provided with a cooling water flow channel, the outlet end of the cooling water inlet channel is connected with the water inlet end of the cooling water flow channel, and the outlet end of the cooling water flow channel is connected with the water inlet end of the cooling water outlet channel. Cooling water is introduced into the cooling water flow channel through the cooling water inlet channel, and the cooling water is discharged through the cooling water outlet channel after heat exchange with the movable bottom mold, which can cool the movable bottom mold and help the formed sheet to be quickly cooled and shaped.

[0024] In order to make the ejector rod rise and fall more smoothly, preferably, the lower template is provided with an ejector rod guide sleeve extending up and down, and the ejector rod is located in the ejector rod guide sleeve and is in sliding cooperation with the ejector rod guide sleeve.

[0025] In a further preferred embodiment, the lower template is provided with a limit shaft extending upward and downward, the ejector rod mounting plate is provided with a limit through hole, the limit shaft is located in the limit through hole, the lower end of the limit shaft is sleeved with a lower limit washer, and the lower limit washer is located below the ejector rod mounting plate. During the process of the ejector rod mounting plate descending, when the lower surface of the ejector rod mounting plate contacts the upper end surface of the lower limit washer, the ejector rod mounting plate will no longer descend. The lower limit washer plays a buffering role and can be made of rubber or polyurethane elastomer.

[0026] During the production process of the thermoforming mold of the utility model, the water introduced from the upper end of the stretching water inlet channel flows in a U-shaped trajectory when passing through the water cavity of the stretching head, and then flows out through the upper end of the stretching water outlet channel. In this way, the water in the water cavity of the stretching head can be replaced in time, so that the water can quickly and fully exchange heat with the stretching head, and the cooling or heating of the stretching head can be quickly and fully realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a preferred embodiment of the utility model;

[0028] Figure 2 yes Figure 1 Enlarged view of part A. DETAILED DESCRIPTION

[0029] like Figure 1 and Figure 2 As shown, the thermoforming mold comprises an upper mold 1 and a lower mold 2 .

[0030] The upper die 1 comprises an upper die plate 11, an upper die body 12, an upper shearing die 13, a pressure ring 14, a stretching head 15, a stretching rod 16 and a stretching rod mounting plate 17. The upper die body 12 is mounted on the upper die plate 11. The upper die body 12 has a cavity. The lower end of the stretching rod 16 is connected to the stretching head 15. The stretching head 15 is located in the cavity of the upper die body 12. The upper end of the stretching rod 16 is connected to the stretching rod mounting plate 17. The upper shearing die 13 is mounted on the upper die body 12 and is located at the lower side of the upper die body 12. The upper shearing die 13 has a cavity. The cavity of the upper shearing die 13 is connected to the cavity of the upper die body 12. A stretching head water chamber 18 is provided in the stretching head 15, and a stretching water inlet channel 19 and a stretching water outlet channel 110 are provided in the stretching rod 16; a partition 111 is provided in the stretching head water chamber 18, and the partition 111 divides the stretching head water chamber 18 into an inlet side cavity 181 and an outlet side cavity 182, the bottom of the inlet side cavity 181 is connected with the bottom of the outlet side cavity 182, the lower end of the stretching water inlet channel 19 is connected with the top of the inlet side cavity 181, and the lower end of the stretching water outlet channel 110 is connected with the top of the outlet side cavity 182.

[0031] In this embodiment, the stretching head 15 includes a stretching head body 151 and a stretching head flange 152. A groove 153 is provided on the top of the stretching head body 151. The stretching head flange 152 is installed on the top of the stretching head body 151 and covers the groove 153. The inner wall of the groove 153 and the lower surface of the stretching head flange 152 together form a stretching head water chamber 18. The lower end of the stretching rod 16 is connected to the stretching head flange 152. There is a water gap 183 between the bottom of the partition 111 and the bottom of the groove. The bottom of the water inlet side cavity 181 is connected to the bottom of the water outlet side cavity 182 through the water gap 183. The partition 111 can be fixedly installed on the lower surface of the stretching head flange 152 or the lower end of the stretching rod 16; or a slot can be set on the opposite side walls of the groove 153, and the two side edges of the partition 111 are respectively inserted into the slots on both sides.

[0032] The stretching rod mounting plate 17 is connected to a stretching rod mounting plate lifting control mechanism. The stretching rod mounting plate lifting control mechanism can be arranged on the upper mold plate; when the upper mold is fixed on the frame, the stretching rod mounting plate lifting control mechanism can also be arranged on the frame. The stretching rod mounting plate lifting control mechanism is used to drive the stretching rod 16 to move up and down; driven by the stretching rod 16, the stretching head 15 can move up and down in the cavity of the upper mold body 12 and the cavity of the upper shear mold 13.

[0033] The upper mold plate 11 is provided with a stretching rod guide sleeve 112 extending up and down. The stretching rod 16 is located in the stretching rod guide sleeve 112 and is in sliding cooperation with the stretching rod guide sleeve 112 .

[0034] In this embodiment, the press ring 14 is arranged in the cavity of the upper shearing die 13, and the stretching head 15 is in the cavity of the press ring 14. A compression spring 113 is installed between the press ring 14 and the upper die plate 11, and when the compression spring 113 contracts, the press ring 14 can apply a certain pressure to the plastic sheet to be formed.

[0035] The lower die 2 includes a lower die plate 21, a lower die body 22, a forming die, a lower shearing die 23, an ejector mounting plate 24, an ejector lifting drive mechanism and a plurality of ejectors 25. The lower die body 22 is mounted on the lower die plate 21, the forming die is mounted on the lower die body 22 (the lower die body 22 has a forming die cavity that can accommodate the forming die, and the forming die is arranged in the forming die cavity), and the forming die has a forming die cavity. The lower shearing die 23 is mounted on the lower die body 22, and the lower shearing die 23 is sleeved on the outside of the forming die. The upper end face of the lower shearing die 23 matches the lower end face of the pressure ring 14 and the position corresponds. The inner edge of the lower end of the upper shearing die 13 is the upper shearing blade; the outer edge of the upper end of the lower shearing die 23 is the lower shearing blade, and the lower shearing blade matches the upper shearing blade.

[0036] The ejector mounting plate 24 is arranged below the lower mold plate 21, the lower ends of the ejector pins 25 are connected to the ejector mounting plate 24, and the ejector mounting plate 24 is connected to the ejector lifting drive mechanism; the lower mold 2 is provided with a plurality of ejector through holes 26 extending up and down, the ejector through holes 26 connect the upper end surface of the forming mold with the lower surface of the lower mold plate 21, the ejector through holes 26 are the same in number as the ejector pins 25 and correspond one to one, and the ejector pins 25 are arranged in the ejector through holes 26. The cross-sectional shape and size of the ejector through holes 26 match those of the ejector pins 25, and the inner wall of the ejector through holes 26 guides the lifting and lowering of the ejector pins 25.

[0037] In this embodiment, the ejector lifting drive mechanism includes an ejector lifting drive cylinder 27, a cylinder body accommodating chamber 28 is provided in the lower mold body 22, a cylinder body 271 of the ejector lifting drive cylinder 27 is fixedly installed in the cylinder body accommodating chamber 28, and a piston rod 272 of the ejector lifting drive cylinder 27 faces downward and is connected to the ejector mounting plate 24; a piston rod guide sleeve 29 is provided on the lower mold plate 21, and the piston rod 272 of the ejector lifting drive cylinder 27 is in the piston rod guide sleeve 29. The piston rod guide sleeve 29 can guide the piston rod 272 of the ejector lifting drive cylinder 27 to rise and fall smoothly.

[0038] A guide column 210 extending up and down is fixedly mounted on the lower template 21, and an ejector mounting plate guide hole 211 is provided on the ejector mounting plate 24. The ejector mounting plate 24 is sleeved on the guide column 210 through the ejector mounting plate guide hole 211 and slidably cooperates with the guide column 210, so that the ejector mounting plate 24 and the ejector 25 can be lifted and lowered more smoothly.

[0039] The lower mold 2 also includes an ejector rod 212 and an ejector rod mounting plate 213, and the molding mold includes a side mold 214 and a movable bottom mold 215 (the ejector pin through hole 26 connects the upper end surface of the side mold 214 with the lower surface of the lower mold plate 21), the side mold 214 is installed on the lower mold body 22 and is located on the inner side of the lower shear mold 23, and the movable bottom mold 215 is connected to the upper end of the ejector rod 212, and the lower end of the ejector rod 212 extends below the lower mold plate 21 and is connected to the ejector rod mounting plate 213. The ejector rod mounting plate 213 is connected to an ejector rod lifting drive mechanism.

[0040] The ejector rod 212 is provided with an air inlet channel 216 extending up and down, the lower end of the air inlet channel 216 is an air inlet end, and the upper end is an air outlet end. The movable bottom mold 215 is provided with at least one blowing hole 217, and each blowing hole 217 is connected to the air outlet end of the air inlet channel 216. The air inlet end of the air inlet channel 216 is connected to a gas supply device (such as a compressed gas source). After the mold is opened, the gas supply device supplies gas to the air inlet channel 216, and the gas is blown out from the blowing hole 217 and blown toward the plastic product, which helps the plastic product to be demolded more smoothly.

[0041] In this embodiment, a gas delivery channel 218 is provided on the ejector rod mounting plate 213, the air inlet end of the air inlet channel 216 in the ejector rod 212 is connected to the gas delivery channel 218, and an air inlet port 227 is provided on the gas delivery channel 218, and the air inlet port 227 is connected to the gas supply device.

[0042] The ejector rod 212 is provided with a cooling water inlet channel 219 and a cooling water outlet channel 220 running up and down. The lower end of the cooling water inlet channel 219 is the water inlet end and the upper end is the water outlet end. The upper end of the cooling water outlet channel 220 is the water inlet end and the lower end is the water outlet end. The movable bottom mold 215 is provided with a cooling water flow channel 221. The water outlet end of the cooling water inlet channel 219 is connected with the water inlet end of the cooling water flow channel 221, and the water outlet end of the cooling water flow channel 221 is connected with the water inlet end of the cooling water outlet channel 220. Cooling water is introduced into the cooling water flow channel 221 through the cooling water inlet channel 219. After heat exchange between the cooling water and the movable bottom mold 215, the cooling water is discharged through the cooling water outlet channel 220, which can cool the movable bottom mold 215 and help to quickly cool and shape the formed sheet.

[0043] The lower mold plate 21 is provided with an ejector rod guide sleeve 222 extending up and down, and the ejector rod 212 is located in the ejector rod guide sleeve 222 and is in sliding cooperation with the ejector rod guide sleeve 222 .

[0044] A tube-aligning guide sleeve 223 is provided on the ejector rod mounting plate 213, and the guide column 210 is located in the tube-aligning guide sleeve 223. When the ejector rod mounting plate 213 is lifted or lowered relative to the lower template 21, the tube-aligning guide sleeve 223 slides along the guide column 210, which can guide the ejector rod mounting plate 213 and the ejector rod 212 to lift or lower more smoothly.

[0045] The lower template 21 is provided with a limit shaft 225 extending upward and downward, and the ejector rod mounting plate 213 is provided with a limit through hole 226, in which the limit shaft 225 is located, and a lower limit washer 224 is sleeved at the lower end of the limit shaft 225, and the lower limit washer 224 is located below the ejector rod mounting plate 213. During the descending process of the ejector rod mounting plate 213, when the lower surface of the ejector rod mounting plate 213 contacts the upper end surface of the lower limit washer 224, the ejector rod mounting plate 213 stops descending. The lower limit washer 224 plays a buffering role and can be made of rubber or polyurethane elastomer.

[0046] The following is a brief description of the working principle of this thermoforming mold:

[0047] When making plastic products, the plastic sheet is first heated to reach the molding temperature; the heated plastic sheet passes through the molding area, and the thermoforming mold is closed at this time, and the compression spring 113 applies a downward thrust to the pressing ring 14, so that the pressing ring 14 presses the sheet against the upper end surface of the lower shearing mold 23, and a molding air chamber is formed between the plastic sheet and the cavity of the upper shearing mold 13;

[0048] Then the stretching rod mounting plate lifting control mechanism drives the stretching rod mounting plate 17 to descend, and the stretching rod mounting plate 17, the stretching rod 16, and the stretching head 15 descend together; the stretching head 15 pre-stretches the plastic sheet (water of a certain temperature can be introduced from the upper end of the stretching water inlet channel 19, and the water flows through the water inlet side cavity 181, the water gap 183, and the water outlet side cavity 182, and exchanges heat with the stretching head 15, and then flows out through the upper end of the stretching water outlet channel 110, so that the stretching head 15 has a suitable temperature);

[0049] Then, compressed air enters the above-mentioned molding air chamber. Under the action of compressed air, the plastic sheet is pressed against the molding die, so that the plastic sheet is molded; and cooling water is introduced into the circulating cooling water path in the mold to cool the molding die (wherein, cooling water is introduced into the cooling water flow channel 221 through the cooling water inlet channel 219, and the cooling water is discharged through the cooling water discharge channel 220 after heat exchange with the movable bottom mold 215, so as to cool the movable bottom mold 215), so that the molded sheet is shaped;

[0050] Then the lower die 2 rises further, and the lower shearing blade at the upper outer edge of the lower shearing die 23 cooperates with the upper shearing blade at the lower inner edge of the upper shearing die 13 to shear the shaped sheet, and the plastic product is sheared out of the shaped sheet to obtain a single plastic product.

[0051] Then, the stretching rod mounting plate lifting control mechanism drives the stretching rod mounting plate 17, the stretching rod 16, and the stretching head 15 to rise together, and the stretching head 15 returns to the cavity of the upper shear die 13;

[0052] Then the lower mold 2 descends, and the edge of the plastic product leaves the pressing ring 14; then the piston rod 272 of the ejector lifting driving cylinder 27 contracts, driving the ejector mounting plate 24 and each ejector 25 to rise, and the upper end of the ejector 25 extends out of the upper end of the ejector through hole 26 and pushes the outer edge of the opening of the plastic product, so that the snap-fit ​​structure of the plastic product is separated from the side mold 214, and then the ejector rod mounting plate 213 and the ejector rod 212 rise, and the movable bottom mold 215 rises and ejects the plastic product (when demolding, the ejector rod 212 and the ejector 25 can also rise at the same time to jointly eject the plastic product), and at the same time, the gas supply device supplies gas to the air inlet channel 216, and the gas is blown out from the blowing hole 217 and blown toward the plastic product to assist demolding;

[0053] Then, air can be blown toward the plastic product to blow the plastic product away from the thermoforming mold, thereby completing a thermoforming process. Subsequently, the ejector rod mounting plate 213 and the ejector rod 212 descend and drive the movable bottom mold 215 to descend to the required position for molding, preparing for the next thermoforming process.

[0054] In other embodiments, when the lower mold includes an ejector rod, the molding mold includes a side mold and a movable bottom mold, the side mold is installed on the lower mold body and is located inside the lower shear mold, the movable bottom mold is connected to the upper end of the ejector rod, and the lower end of the ejector rod extends below the lower mold plate and is connected to the ejector mounting plate. During demoulding, the ejector rod and the ejector rise simultaneously under the drive of the ejector lifting drive mechanism to eject the plastic product together.

Claims

1. A thermoforming mold, comprising an upper mold and a lower mold; the upper mold comprises an upper mold, an upper mold body, a stretching head, a stretching rod and a stretching rod mounting plate, the upper mold body is mounted on the upper mold body, the upper mold body has a cavity, the lower end of the stretching rod is connected to the stretching head, the stretching head is in the cavity of the upper mold body, and the upper end of the stretching rod is connected to the stretching rod mounting plate; the lower mold comprises a lower mold body, a lower mold body and a forming mold, the lower mold body is mounted on the lower mold body, the forming mold is mounted on the lower mold body, and the forming mold has a forming mold cavity; the stretching head is provided with a stretching head water storage cavity, and the stretching rod is provided with a stretching water inlet channel and a stretching water outlet channel, wherein: A partition is provided in the stretching head water chamber, which divides the stretching head water chamber into an inlet side cavity and an outlet side cavity. The bottom of the inlet side cavity is connected with the bottom of the outlet side cavity, the lower end of the stretching water inlet channel is connected with the top of the inlet side cavity, and the lower end of the stretching water outlet channel is connected with the top of the outlet side cavity.

2. The thermoforming mold according to claim 1, characterized in that: The stretching head includes a stretching head body and a stretching head flange. A groove is provided on the top of the stretching head body. The stretching head flange is installed on the top of the stretching head body and covers the groove. The inner wall of the groove and the lower surface of the stretching head flange together form the stretching head water storage chamber. The lower end of the stretching rod is connected to the stretching head flange. There is a water gap between the bottom of the partition and the bottom of the groove. The bottom of the water inlet side cavity is connected with the bottom of the water outlet side cavity through the water gap.

3. The thermoforming mold according to claim 1 or 2, characterized in that: The upper mold also includes an upper shearing mold and a pressure ring. The upper shearing mold is installed on the upper mold body. The upper shearing mold has a cavity, and the pressure ring is arranged in the cavity of the upper shearing mold; the lower mold also includes a lower shearing mold, an ejector mounting plate, an ejector lifting drive mechanism and at least one ejector. The lower shearing mold is installed on the lower mold body, and the lower shearing mold is sleeved on the outside of the forming mold. The upper end surface of the lower shearing mold matches the lower end surface of the pressure ring and the positions correspond. The ejector mounting plate is arranged below the lower template, and the lower end of each ejector is connected to the ejector mounting plate, and the ejector mounting plate is connected to the ejector lifting drive mechanism; at least one ejector through hole running up and down is provided on the lower mold, and the ejector through hole connects the upper end surface of the forming mold with the lower surface of the lower template. The ejector through hole is the same as the number of ejectors and corresponds one to one, and the ejector is arranged in the ejector through hole.

4. The thermoforming mold according to claim 3, characterized in that: The ejector lifting drive mechanism comprises an ejector lifting drive cylinder, a cylinder accommodating cavity is provided in the lower mold body, the cylinder body of the ejector lifting drive cylinder is fixedly installed in the cylinder accommodating cavity, the piston rod of the ejector lifting drive cylinder faces downward and is connected to the ejector mounting plate; a piston rod guide sleeve is provided on the lower mold plate, and the piston rod of the ejector lifting drive cylinder is located in the piston rod guide sleeve.

5. The thermoforming mold according to claim 3, characterized in that: The lower mold also includes an ejector rod and an ejector rod mounting plate, the forming mold includes a side mold and a movable bottom mold, the side mold is installed on the lower mold body and is located on the inner side of the lower shear mold, the movable bottom mold is connected to the upper end of the ejector rod, and the lower end of the ejector rod extends below the lower mold plate and is connected to the ejector rod mounting plate; Alternatively, the lower mold also includes an ejector rod, the molding mold includes a side mold and a movable bottom mold, the side mold is installed on the lower mold body and is located on the inner side of the lower shear mold, the movable bottom mold is connected to the upper end of the ejector rod, and the lower end of the ejector rod extends to the bottom of the lower mold plate and is connected to the ejector mounting plate.

6. The thermoforming mold according to claim 5, characterized in that: The ejector rod is provided with an air inlet channel extending up and down, the lower end of the air inlet channel is the air inlet end, and the upper end is the air outlet end. The movable bottom mold is provided with at least one blowing hole, and each blowing hole is connected to the air outlet end of the air inlet channel.

7. The thermoforming mold according to claim 5, characterized in that: A gas delivery channel is provided on the ejector rod mounting plate, an air inlet end of the air inlet channel in the ejector rod is connected to the gas delivery channel, an air inlet is provided on the gas delivery channel, and the air inlet is connected to the gas supply device.

8. The thermoforming mold according to claim 5, characterized in that: The ejector rod is provided with a cooling water inlet channel and a cooling water outlet channel which run up and down. The lower end of the cooling water inlet channel is the water inlet end and the upper end is the water outlet end. The upper end of the cooling water outlet channel is the water inlet end and the lower end is the water outlet end. A cooling water flow channel is provided in the movable bottom mold. The water outlet end of the cooling water inlet channel is connected with the water inlet end of the cooling water flow channel, and the water outlet end of the cooling water flow channel is connected with the water inlet end of the cooling water outlet channel.

9. The thermoforming mold according to claim 3, characterized in that: A guide column extending up and down is fixedly mounted on the lower template, and an ejector mounting plate guide hole is arranged on the ejector mounting plate. The ejector mounting plate is sleeved on the guide column through the ejector mounting plate guide hole and is slidably matched with the guide column.

10. The thermoforming mold according to claim 3, characterized in that: There are a plurality of ejector pin through holes, and there are a plurality of ejector pins correspondingly; the cross-sectional shape and size of the ejector pin through holes match those of the ejector pins.

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