Three-color hot runner mold capable of releasing first in mold and injection molding method of three-color hot runner mold

Abstract

The invention discloses a three-color hot runner mold capable of releasing firstly in a mold. The three-color hot runner mold comprises a front mold and a rear mold, the demolding mechanism comprises a driving assembly which is arranged on the front mold bottom plate and is linked with the pulling plate, and a slide assembly; the slide assembly comprises a one-color slide assembly, a two-color slide assembly and a three-color slide assembly which are respectively arranged corresponding to the one-color cavity, the two-color cavity and the three-color cavity; a rear mold; and the driving assembly is used for driving the pulling plate to move to a retreating position before the front mold and the rear mold are opened, so that the slide assembly can release a one-color product, a two-color product and a three-color product at the same time. According to the three-color hot runner mold capable of releasing first in the mold provided by the invention, by adopting the technical scheme, the driving assembly drives the pulling plate to link the one-color slide assembly, the two-color slide assembly and the three-color slide assembly to synchronously act before mold opening, so that simultaneous releasing of product buckling positions in a one-color mold cavity, a two-color mold cavity and a three-color mold cavity is realized; and the demolding time is greatly shortened.

Description

Technical Field

[0001] This application relates to the field of mold technology, and in particular to a three-color hot runner mold with in-mold release and its injection molding method. Background Technology

[0002] Multi-color injection molding technology enables the bonding of different materials or colors of plastic onto the same product, and is widely used in consumer electronics, automobiles, daily necessities, and other fields to enhance product appearance, functionality, and added value. Existing two-and-a-half-plate molds, where the A-plate and panel are opened first, require a hot runner sleeve to protect the hot runner during the opening process. Therefore, this mold structure makes it difficult to apply hot runner systems, or space constraints prevent the design of effective hot runner protection mechanisms, limiting its application in high-efficiency, precision multi-color injection molding. Summary of the Invention

[0003] In order to overcome the shortcomings of existing multi-color molds that are not suitable for hot runner design, this application provides a three-color hot runner mold with in-mold release first.

[0004] The technical solution for the in-mold first-release three-color hot runner mold provided in this application is as follows: A three-color hot runner mold with in-mold release first, including: A front mold includes a front mold base plate and a front mold template, a movable inner cavity disposed on the front mold base plate, a pull plate disposed in the movable inner cavity, and a cavity disposed on the front mold template; the cavity includes a one-color cavity for forming a one-color product, a two-color cavity for forming a two-color product, and a three-color cavity for forming a three-color product; the movable inner cavity allows the pull plate to move to a retracted position or a working position; The demolding mechanism includes a drive assembly disposed on the front mold base plate and linked with the pull plate, and a sliding assembly; the sliding assembly includes a one-color sliding assembly, a two-color sliding assembly, and a three-color sliding assembly respectively disposed corresponding to the one-color cavity, the two-color cavity, and the three-color cavity; Rear mold; The driving component is used to drive the pull plate to the retracted position before the front mold and the rear mold are opened, so that the sliding component can simultaneously release the single-color product, the two-color product and the three-color product.

[0005] By adopting the above technical solution, the driving component drives the pull plate to move synchronously with the one-color slide component, the two-color slide component, and the three-color slide component before mold opening, realizing the simultaneous disengagement of the products in the one-color cavity, two-color cavity, and three-color cavity, which greatly shortens the demolding time.

[0006] Preferably, the driving assembly includes a first hydraulic cylinder disposed on the front mold base plate, a first shovel base disposed on the output end of the first hydraulic cylinder, and a first sliding position that cooperates with the first shovel base and is disposed on the pull plate. The first hydraulic cylinder drives the first sliding position to retract in the mold opening direction through the first shovel base, so as to drive the pull plate to the retracted position.

[0007] By adopting the above technical solution, using a first hydraulic cylinder as the power source, and through the inclined surface cooperation between the first shovel base and the first sliding contact, the linear output of the first hydraulic cylinder is converted into the power to drive the lifting and lowering of the pull plate. This design allows the locking mechanism within the mold to no longer rely on the opening and closing of the mold for driving, and can complete the unlocking action before the mold opens.

[0008] Preferably, the single-color sliding component includes a single-color shovel base connected to the pull plate, and two single-color sliding parts that cooperate with the single-color shovel base. The two single-color sliding parts are located on both sides of the single-color shovel base. When the single-color shovel base retracts, the two single-color sliding parts move towards each other to disengage the single-color fasteners on the single-color product.

[0009] By adopting the above technical solution, the single-color shovel base of the connecting plate drives the two symmetrically arranged single-color sliding positions to retract inward, which can effectively disengage from the single-color fastener from the inside of the product. The structure is compact and the action is synchronized.

[0010] Preferably, the two-color row assembly includes the one-color row assembly, a two-color shovel base disposed on the pull plate, and a two-color row that cooperates with the two-color shovel base, wherein the two-color row is provided with a one-color clearance groove for the one-color row to pass through; When the two-color shovel base retracts, the two-color slide tilts out to disengage the two-color fasteners on the two-color product, and the one-color slide assembly disengages the one-color fasteners on the two-color product.

[0011] By adopting the above technical solution, a clearance groove is set on the two-color slide, allowing the one-color slide to pass through. This enables the one-color slide component and the two-color slide component to operate independently and simultaneously without interfering with each other on the two-color product, and to disengage from their corresponding snap-fit ​​positions respectively, thus solving the demolding problem caused by the overlapping of multiple snap-fit ​​positions.

[0012] Preferably, the three-color row position assembly includes a second shovel base and a third shovel base disposed on the pull plate, a second row position cooperating with the second shovel base, and a third row position cooperating with the third shovel base, wherein the second row position and the third row position are arranged opposite to each other; When the second shovel base and the third shovel base retract, the second row position and the third row position tilt outwards in a direction away from each other to disengage the three-color fasteners on the three-color product.

[0013] By adopting the above technical solution, the two opposing second and third shovel bases move under the action of the pull plate, which can effectively disengage from the three-color fasteners on the outside of the three-color product, with balanced disengagement force and stable operation.

[0014] Preferably, it further includes a guiding mechanism, which includes a guide block with its two ends respectively connected to the front mold base plate and the front mold template, a guide groove disposed on the first shovel base for the guide block to be embedded in, and a guide hole disposed on the pull plate for the guide block to pass through.

[0015] By adopting the above technical solution, the guiding mechanism provides a precise reciprocating motion track for the first shovel base and the pull plate, ensuring that the movement of the drive component and the entire demolding mechanism is smooth and reliable, preventing deviation or jamming during the operation, and improving the system rigidity and service life.

[0016] Preferably, it also includes a locking mechanism for securing the pull plate in the working position.

[0017] By adopting the above technical solution, the locking mechanism can firmly lock the pull plate in the working position during the injection and holding pressure stages, preventing the pull plate from accidentally retracting due to injection pressure, thereby ensuring the stability of the cavity dimensions and the molding quality.

[0018] Preferably, the locking mechanism includes a second hydraulic cylinder disposed on the front template, a locking block disposed on the output end of the second hydraulic cylinder, and a locking groove disposed on the pull plate. When the pull plate is in the working position, the second hydraulic cylinder pushes the locking block to insert into the locking groove to restrict the movement of the pull plate.

[0019] By adopting the above technical solution, the cylinder-driven plug-in locking mechanism has a large locking force and a rapid response, enabling precise and reliable locking and releasing of the working position of the pull plate, with a high degree of automation.

[0020] Preferably, the single-color cavity, the two-color cavity, and the three-color cavity are arranged in a triangular pattern, and the rear mold is rotated 120° relative to the front mold so that the single-color product formed in the single-color cavity enters the two-color cavity and the three-color cavity in sequence.

[0021] By adopting the above technical solution, the cavities are triangularly distributed. Combined with the 120° rotation of the rear mold, the product is able to flow orderly between the three cavities and be sequentially superimposed for injection molding to form a three-color product.

[0022] The present invention also provides an injection molding method for a three-color mold, comprising a three-color hot runner mold with in-mold release as described above, and the injection molding process including the following steps: S1: Front mold and rear mold assembly; S2: Perform the first color injection molding, followed by cooling; S3: The drive assembly moves the pull plate to the retracted position; S4: Opening of the front and rear molds; S5: Rotate the rear mold counterclockwise 120° before closing the mold; S6: The drive assembly moves the pull plate to the working position; S7: Perform first-color injection molding and second-color injection molding, followed by cooling; S8: Repeat steps S3-S6, then perform the first color injection, the second color injection, and the third color injection, followed by cooling. S9: After repeating steps S3-S4, eject the three-color product and remove the product and runner.

[0023] By adopting the above technical solution, the release action is embedded after the cooling stage of each injection molding cycle and before mold opening, so that the release time and cooling time are parallel or overlapped, thereby significantly shortening the total molding cycle of a single product and improving production efficiency. Moreover, it does not affect the design of the hot runner.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. Based on a three-color hot runner mold, by using a drive assembly to drive a pull platen to drive the slide assembly, it is possible to perfectly realize that the pull platen opens inside the mold before the mold opens. The pull platen drives the first-color slide assembly, the second-color slide assembly, and the third-color slide assembly to simultaneously release, thus driving the three-color slide assembly to move and release. This structure solves the requirement that the product structure needs to open the slide release mechanism internally before the front mold platen opens, and the front mold pin pull platen can also effectively resist the pressure from injection molding in the mold closed state.

[0025] 2. Existing processes utilize multiple injection molding, producing the first and second shots first, then combining them in a third shot to obtain a complete three-color product. This application achieves complete product production within a single mold, eliminating the need for multiple injection molding processes, thus shortening the molding cycle and improving production efficiency.

[0026] 3. Compared to previous production methods, this application not only reduces mold costs by eliminating the need for two sets of molds for injection molding and instead completing production within a single mold, thus reducing labor costs by eliminating the manual labor required for injection molding, but also shortens production time and improves production efficiency because the entire product is produced in one mold. Attached Figure Description

[0027] Figure 1 This is a structural schematic diagram of the front mold.

[0028] Figure 2 This is a schematic diagram of the structure of the present invention.

[0029] Figure 3 This is a diagram of the internal structure of the front mold.

[0030] Figure 4 This is a schematic diagram of the drive component.

[0031] Figure 5 This is a schematic diagram of the locking mechanism.

[0032] Figure 6 This is a structural diagram of a single-color row component.

[0033] Figure 7 This is a schematic diagram of the structure of a two-color row position component.

[0034] Figure 8 This is a schematic diagram of the structure of the three-color row position component.

[0035] Explanation of reference numerals in the attached figures: 1. Front mold; 11. Front mold base plate; 12. Front mold plate; 13. Movable inner cavity; 14. Pull plate; 15. Single-color cavity; 16. Two-color cavity; 17. Three-color cavity; 2. Demolding mechanism; 21. Drive assembly; 211. First hydraulic cylinder; 212. First shovel base; 213. First slide; 22. Single-color slide assembly; 221. Single-color shovel base; 222. Single-color slide; 223. Single-color product; 23. Two-color slide assembly; 23 1. Two-color shovel base; 232. Two-color slide; 233. One-color clearance groove; 234. Two-color product; 24. Three-color slide assembly; 241. Second shovel base; 242. Third shovel base; 243. Second slide; 244. Third slide; 245. Three-color product; 3. Rear mold; 4. Guide mechanism; 41. Guide block; 42. Guide groove; 43. Guide hole; 5. Locking mechanism; 51. Second hydraulic cylinder; 52. Locking block; 53. Locking groove. Detailed Implementation

[0036] The following is in conjunction with the appendix Figures 1 to 8 This application will be described in further detail.

[0037] This application discloses a three-color hot runner mold with in-mold release. (Refer to...) Figure 1 A three-color hot runner mold that releases first within the mold, including: The front mold 1 includes a front mold base plate 11 and a front mold template 12, a movable inner cavity 13 disposed on the front mold base plate 11, a pull plate 14 disposed in the movable inner cavity 13, and a cavity disposed on the front mold template 12; the cavity includes a single-color cavity 15 for forming a single-color product, a two-color cavity 16 for forming a two-color product, and a three-color cavity 17 for forming a three-color product; the movable inner cavity 13 allows the pull plate 14 to move to a retracted position or a working position; The demolding mechanism 2 includes a drive assembly 21 disposed on the front mold base plate 11 and linked with the pull plate 14, and a sliding assembly; the sliding assembly includes a single-color sliding assembly 22, a two-color sliding assembly 23, and a three-color sliding assembly 24 respectively disposed corresponding to the single-color cavity 15, the two-color cavity 16, and the three-color cavity 17. Rear mold 3; The drive component 21 is used to drive the pull plate 14 to the retraction position before the front mold 1 and the rear mold 3 are opened, so that the sliding component can simultaneously release the single-color product, the two-color product and the three-color product.

[0038] Furthermore, such as Figure 2 As shown, the driving assembly 21 includes a first hydraulic cylinder 211 disposed on the front mold base plate 11, a first shovel base 212 disposed on the output end of the first hydraulic cylinder 211, and a first sliding position 213 that cooperates with the first shovel base 212 and is disposed on the pull plate 14. The first hydraulic cylinder 211 drives the first sliding position 213 to retract in the mold opening direction through the first shovel base 212, so as to drive the pull plate 14 to the retracted position.

[0039] Using a first hydraulic cylinder as the power source, the linear output of the first hydraulic cylinder is efficiently and reliably converted into the precise displacement required to drive the pull plate through the inclined surface cooperation between the first shovel base and the first slide. The drive system is completely independent of the mold opening and closing mechanism, realizing the in-mold release action without relying on or interfering with the movement of the injection molding machine itself.

[0040] Furthermore, such as Figure 6 As shown, the single-color mounting component 22 includes a single-color shovel base 221 connected to the pull plate 14, and two single-color mounting points 222 that cooperate with the single-color shovel base 221. The two single-color mounting points 222 are located on both sides of the single-color shovel base 221. When the single-color shovel base 221 retracts, the two single-color mounting points 222 move towards each other to disengage the single-color fasteners on the single-color product.

[0041] This symmetrical, inward-retracting release method can evenly release the clamping force from the inside of the product, effectively preventing product tilting, tearing, or buckle deformation caused by unilateral release.

[0042] Furthermore, such as Figure 7 As shown, the two-color row component 23 includes the one-color row component 22, a two-color shovel base 231 disposed on the pull plate 14, and a two-color row 232 that cooperates with the two-color shovel base 231. The two-color row 232 is provided with a one-color clearance groove 233 for the one-color row 222 to pass through. When the two-color shovel base 231 retracts, the two-color slide 232 tilts out to disengage the two-color fasteners on the two-color product, and the one-color slide assembly 22 disengages the one-color fasteners on the two-color product.

[0043] The two-color sliding component is designed based on the one-color sliding component. The one-color clearance groove allows the one-color sliding component to operate independently without affecting each other. The two-color sliding component, however, performs an independent tilting and retraction action driven by the two-color shovel base to disengage from the fastener formed by the two-color product covering the outer layer. Both components operate simultaneously and independently during one backward stroke of the pull plate.

[0044] Furthermore, such as Figure 8 As shown, the three-color row position assembly 24 includes a second shovel base 241 and a third shovel base 242 disposed on the pull plate 14, a second row position 243 cooperating with the second shovel base 241, and a third row position 244 cooperating with the third shovel base 242. The second row position 243 and the third row position 244 are arranged opposite to each other. When the second shovel base 241 and the third shovel base 242 retract, the second row position 243 and the third row position 244 tilt and withdraw in a direction away from each other to disengage the three-color fasteners on the three-color product.

[0045] As the pull plate retracts, these two sliding positions, driven by the inclined surfaces of their respective shovel bases, perform synchronized but opposite outward tilting and expanding movements. This symmetrical outward expansion release method smoothly releases the clamping force on the outer fasteners of the product, preventing the product from shifting or deforming due to unilateral force. It complements the inward retraction movement of the single-color sliding position.

[0046] Furthermore, such as Figure 3 , Figure 4 As shown, it also includes a guide mechanism 4, which includes a guide block 41 with its two ends connected to the front mold base plate 11 and the front mold template 12 respectively, a guide groove 42 provided on the first shovel base 212 for the guide block 41 to be embedded, and a guide hole 43 provided on the pull plate 14 for the guide block 41 to pass through.

[0047] The guide groove on the first shovel base and the guide hole on the pull plate both use this guide block as their track. This design ensures that the first shovel base moves in a straight line under the drive of the first hydraulic cylinder, avoiding swaying; at the same time, it guides the pull plate to move smoothly in the movable inner cavity, preventing jamming due to uneven force.

[0048] Furthermore, such as Figure 5 As shown, it also includes a locking mechanism 5 for fixing the pull plate 14 in the working position.

[0049] The locking mechanism is crucial for ensuring the stability of the mold cavity dimensions and the quality of molding during the high-pressure injection stage. During injection, the injection pressure acts on various parts of the cavity and may also be indirectly transmitted to the slides through the product, creating a potential tendency for the ejector plate to retract. Even a slight backward movement of the ejector plate can lead to slight loosening of the slides, potentially causing flash, dimensional errors, or incomplete molding of the snap-fit ​​parts. The locking mechanism actively overcomes this tendency during injection and holding pressure, rigidly locking the ejector plate in its working position. This ensures the static rigidity of the entire cavity and demolding mechanism throughout the molding cycle, guaranteeing product dimensional accuracy and appearance quality.

[0050] Furthermore, the locking mechanism 5 includes a second hydraulic cylinder 51 disposed on the front template 12, a locking block 52 disposed on the output end of the second hydraulic cylinder 51, and a locking groove 53 disposed on the pull plate 14. When the pull plate 14 is in the working position, the second hydraulic cylinder 51 pushes the locking block 52 to insert into the locking groove 53 to restrict the movement of the pull plate 14.

[0051] First, the locking force is directly provided by the hydraulic cylinder, which is powerful and adjustable, and can reliably resist injection molding pressure. Second, the action is rapid and can be precisely coordinated with the timing of the drive hydraulic cylinder to achieve an automated cycle of unlocking-disengagement-reset-locking. Third, the locking block is inserted into the locking groove for a rigid lock, with no risk of slippage and a stable locking state. Fourth, the structure is relatively simple, with few points of failure, and is easy to maintain and monitor.

[0052] Furthermore, such as Figure 1 As shown, the single-color cavity 15, the two-color cavity 16, and the three-color cavity 17 are arranged in a triangular pattern. The rear mold 3 is rotated 120° relative to the front mold 1 so that the single-color product formed in the single-color cavity 15 enters the two-color cavity 16 and the three-color cavity 17 in sequence.

[0053] The triangular cavity layout of this application is the most classic and optimized arrangement for rotary three-color molds. Combined with the precise 120° rotation of the rear mold each time, this layout achieves a sequential production process from one-color molding to two-color coating and then to three-color coating with the shortest rotation path and the highest space utilization. Each cavity is dedicated to a specific injection stage, allowing for more targeted mold temperature control, cooling water channel layout, and venting design.

[0054] This embodiment also discloses a three-color mold injection method, which includes a three-color hot runner mold with in-mold release as described above, and the injection process includes the following steps: S1: Front mold and rear mold assembly; S2: Perform the first color injection molding, followed by cooling; S3: The drive assembly moves the pull plate to the retracted position; S4: Opening of the front and rear molds; S5: Rotate the rear mold counterclockwise 120° before closing the mold; S6: The drive assembly moves the pull plate to the working position; S7: Perform first-color injection molding and second-color injection molding, followed by cooling; S8: Repeat steps S3-S6, then perform the first color injection, the second color injection, and the third color injection, followed by cooling. S9: After repeating steps S3-S4, eject the three-color product and remove the product and runner.

[0055] In traditional methods, release must occur after mold opening or during rotation, incurring additional cycle time. In this method, however, release preparation is performed inside the mold while the product is cooling. Therefore, only simple separation and rotation are required after mold opening, saving significant time. This pre-release before mold opening method is an effective way to improve the efficiency of three-color injection molding production, especially suitable for high-volume production scenarios.

[0056] Furthermore, before injection molding, a locking mechanism secures the pull plate in its working position. Specifically, the second hydraulic cylinder extends and presses the locking block against the locking groove, thereby fixing the position of the pull plate. This effectively improves the pull plate's ability to withstand the pressure generated during injection molding.

[0057] Furthermore, after cooling following injection molding, the locking mechanism releases the pull plate. The pull plate can then be moved to the retracted position.

[0058] The implementation principle of the three-color hot runner mold with in-mold release in this application embodiment is as follows: 1. Injection molding and preparation stage: When the mold is closed, the mold completes the injection molding of a single-color product. At this time, the pull plate is in the working position and is locked by the locking mechanism to withstand the high pressure of injection molding and ensure the stability of the cavity dimensions.

[0059] 2. In-mold release stage: After injection molding is completed and the cooling stage begins, the second cylinder of the locking mechanism retracts the locking block, releasing the constraint on the pull plate.

[0060] Subsequently, the first cylinder of the drive assembly actuates, pushing the first shovel base. The first shovel base drives the first sliding position that cooperates with it through the inclined plane, thereby driving the pull plate to move along the guide mechanism to the retracted position.

[0061] As the pull plate moves, it simultaneously drives the single-color shovel base, the double-color shovel base, the second shovel base, and the third shovel base installed on it to move backward. Among these, The single-color shovel base retracts, driving the two single-color slides to retract inward, disengaging from the single-color fasteners on the single-color product. Within the two-color cavity, this action similarly disengages the single-color portion of the inner layer of the product.

[0062] The two-color shovel base retracts, driving the two-color slide to move along the inclined direction, disengaging from the two-color fastener on the two-color product.

[0063] The second and third shovel bases retract, driving the second and third moving parts to tilt outwards respectively, disengaging from the three-color fasteners on the three-color product.

[0064] At this point, while the mold is still closed, all interlocking parts on the product within all cavities have been simultaneously and completely disengaged. This process occurs concurrently with the product's cooling time and does not require additional mold opening cycles.

[0065] 3. Mold opening and rotation stage: After the initial release action is completed, the mold opens normally. Since all fastener constraints have been released in advance, the product only has a slight clamping force, resulting in a small and smooth mold opening force. The rear mold, carrying three sets of products, rotates 120° and enters the next station.

[0066] 4. Reset and locking stage: Before mold closing, the hydraulic cylinder of the drive component reverses its movement, pulling the pull plate precisely back to the "working position," and all slide components subsequently return to the molding state. After mold closing, the locking mechanism activates again, locking the pull plate and preparing for the next high-pressure injection molding.

[0067] The core advantage of its working principle is that by changing the release action from the traditional mold-opening release to be completed in the mold-closed state, the molding cycle is greatly shortened. Simultaneously, all movements are completed within the mold, eliminating the complex spatial interference risks of traditional rotary demolding, thus improving production efficiency and system reliability. It also allows hot runners to form on the mold-closing surface, making it suitable for hot runner molds.

[0068] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An in-mold triac, hot runner mold characterized in that, The utility model relates to a three-color injection moulding machine, comprising: a front mould (1) comprising a front mould base plate (11), a movable inner cavity (13) arranged on the front mould base plate (11), a pull plate (14) arranged in the movable inner cavity (13), and a cavity arranged on a front mould plate (12); the cavity comprises a single-color cavity (15) for forming a single-color product, a two-color cavity (16) for forming a two-color product, and a three-color cavity (17) for forming a three-color product; the movable inner cavity (13) is used for moving the pull plate (14) to a retreat position or a working position; an ejection mechanism (2) comprising a driving assembly (21) arranged on the front mould base plate (11) and connected with the pull plate (14), and a row position assembly; the row position assembly comprises a single-color row position assembly (22), a two-color row position assembly (23), and a three-color row position assembly (24) arranged respectively corresponding to the single-color cavity (15), the two-color cavity (16), and the three-color cavity (17); a rear mould (3); the driving assembly (21) is used for driving the pull plate (14) to move to the retreat position before the front mould (1) and the rear mould (3) are opened, so that the row position assembly simultaneously ejects the single-color product, the two-color product, and the three-color product.

2. The in-mold pop-off three-color hot runner mold of claim 1, wherein: the driving assembly (21) comprises a first oil cylinder (211) arranged on the front mould base plate (11), a first shovel base (212) arranged on an output end of the first oil cylinder (211), and a first row position (213) matched with the first shovel base (212) and arranged on the pull plate (14); the first oil cylinder (211) drives the first row position (213) to retreat in the opening direction through the first shovel base (212), so as to drive the pull plate (14) to move to the retreat position.

3. The in-mold pop-off three-color hot runner mold of claim 1, wherein: the single-color row position assembly (22) comprises a single-color shovel base (221) connected with the pull plate (14), and two single-color row positions (222) matched with the single-color shovel base (221); the two single-color row positions (222) are arranged on both sides of the single-color shovel base (221); when the single-color shovel base (221) retreats, the two single-color row positions (222) move in the direction of approaching each other to eject a single-color row position on the single-color product.

4. The in-mold pop-off three-color hot runner mold of claim 3, wherein: the two-color row position assembly (23) comprises the single-color row position assembly (22), a two-color shovel base (231) arranged on the pull plate (14), and a two-color row position (232) matched with the two-color shovel base (231); the two-color row position (232) is provided with a single-color giving-up slot (233) for the single-color row position (222) to pass through; when the two-color shovel base (231) retreats, the two-color row position (232) is tilted to exit to eject a two-color row position on the two-color product, and the single-color row position assembly (22) ejects a single-color row position on the two-color product.

5. The in-mold pop-off three-color hot runner mold of claim 1, wherein: The three-color row position assembly (24) comprises a second shoveling base (241) and a third shoveling base (242) arranged on the pull plate (14), a second row position (243) matched with the second shoveling base (241), and a third row position (244) matched with the third shoveling base (242), wherein the second row position (243) is arranged opposite to the third row position (244). When the second shoveling base (241) and the third shoveling base (242) are retracted, the second row position (243) and the third row position (244) are tilted to exit in a direction away from each other to release the three-color buckles on the three-color product.

6. The in-mold pop-off three-color hot runner mold of claim 2, wherein: The guiding mechanism (4) comprises a guide block (41) connected to the front mold base plate (11) and the front mold plate (12) at two ends, a guiding groove (42) arranged on the first shoveling base (212) and embedded with the guide block (41), and a guide hole (43) arranged on the pull plate (14) and passed through by the guide block (41).

7. The in-mold pop-off three-color hot runner mold of claim 2, wherein: The locking mechanism (5) is arranged on the pull plate (14) to fix the pull plate (14) in the working position.

8. The in-mold pop-off three-color hot runner mold of claim 7, wherein: The locking mechanism (5) comprises a second oil cylinder (51) arranged on the front mold plate (12), a locking block (52) arranged on the output end of the second oil cylinder (51), and a locking groove (53) arranged on the pull plate (14), wherein when the pull plate (14) is in the working position, the second oil cylinder (51) pushes the locking block (52) to insert into the locking groove (53) to limit the movement of the pull plate (14).

9. The in-mold pop-off three-color hot runner mold of claim 7, wherein: The one-color cavity (15), the two-color cavity (16), and the three-color cavity (17) are arranged in a triangular distribution, and the rear mold (3) is rotated by 120° relative to the front mold (1) to make the one-color product formed in the one-color cavity (15) sequentially enter the two-color cavity (16) and the three-color cavity (17).

10. Injection molding method of a three-color mold, characterized in that: The method comprises the following steps: S1: closing the front mold and the rear mold; S2: performing first-color injection molding and cooling after injection molding; S3: driving the pull plate to move to the retracted position by the driving assembly; S4: opening the front mold and the rear mold; S5: rotating the rear mold counterclockwise by 120° and then closing the mold again; S6: driving the pull plate to move to the working position by the driving assembly; S7: performing first-color injection molding and second-color injection molding and cooling after injection molding; S8: repeating steps S3-S6, performing first-color injection molding, second-color injection molding, and third-color injection molding, and cooling after injection molding; S9: repeating steps S3-S4, ejecting the three-color product, and taking out the product and the flow channel.

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