A method and apparatus for in-mold assembly of a product

Abstract

The application discloses a product in-mold assembly method and device in the technical field of injection molding and press-fitting molds, and the method adopts an injection mold and comprises the following steps: injection molding: molten plastic is injected into a mold cavity to form a connected injection molded part, the connected injection molded part comprises at least two products and a connecting runner between the two adjacent products, and the products are provided with buckles and clamping grooves; horizontal mold opening: a row position mechanism is driven to open the mold cavity in the horizontal direction to provide a press-fitting space; in-mold press-fitting: a press-fitting mechanism is driven to longitudinally extend into one side of the mold cavity to apply longitudinal pressure to the products, the buckles are matched with the clamping grooves, the press-fitting of the products is completed, and the products and the connecting runner are ejected to complete the discharging. The two independent processes of injection molding and press-fitting are integrated into one station and are synchronously performed, the error caused by carrying is reduced, and the press-fitting precision is ensured.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, specifically to a method and apparatus for in-mold assembly of products. Background Technology

[0002] The patent document with publication number CN108891006A discloses a production process for two-color bottles, which involves multiple pieces of equipment such as injection molding machines, rotating mechanisms, sprue shearing machines, blow molding machines, transfer printing machines, and bagging machines. The process requires multiple product transfers between steps, resulting in a long production cycle and high equipment investment costs.

[0003] There are two main traditional methods for producing injection-molded products: one is to design two-color molds for overlay molding, and the other is to assemble the product manually after injection molding. In the two-color overlay molding process, a rotary two-color injection molding machine is usually used. After the first color is injected, the mold rotates 180 degrees to the second color station for the second injection. After the product is formed, it needs to be transferred to a special pressing tool for pressing, and then transferred to a gate-cutting mechanism to remove the sprue before finally unloading. The entire process involves multiple pieces of equipment such as injection molding machines, rotary tables, pressing equipment, and gate-cutting equipment. The product needs to be transferred repeatedly between multiple stations, which increases the product cycle and increases the cost of mold making and equipment investment, making it uncompetitive.

[0004] In addition, while existing in-mold hot cutting technology can cut the sprue inside the mold, it only involves a single action and cannot complete the product pressing at the same time; while manual assembly methods have problems such as low efficiency, poor positioning accuracy, and difficulty in ensuring consistency, and labor costs continue to rise. Summary of the Invention

[0005] To overcome the problems of existing two-color die-casting processes that require multiple product transfers between injection molding machines, rotary tables, pressing equipment, and sprue cutting mechanisms, resulting in long production cycles, high equipment investment costs, high mold manufacturing costs, and low efficiency, poor positioning accuracy, and difficulty in ensuring consistency of manual assembly methods, this invention provides a product in-mold assembly method and apparatus.

[0006] The technical solution of this invention is as follows:

[0007] In a first aspect, the present invention provides an in-mold assembly method for a product, using an injection mold, comprising the following steps:

[0008] S1. Injection molding: Molten plastic is injected into the mold cavity to form a one-piece injection molded part. The one-piece injection molded part includes at least two products and a sprue connecting two adjacent products. The products are provided with buckles and slots.

[0009] S2, Horizontal mold opening: Drive the sliding mechanism to open, making the mold cavity open horizontally, and making room for pressing;

[0010] S3, In-mold pressing: The driving pressing mechanism extends longitudinally into one side of the mold cavity to apply longitudinal pressure to the product, so that the buckle and the slot are correspondingly engaged to complete the pressing of the product itself;

[0011] S4. Ejection and unloading: Eject the pressed product and the connecting sprue to complete the unloading.

[0012] In a preferred embodiment, the method further includes the following step before step S3:

[0013] Sprue detachment step: Drive the sprue insert pin to break the connecting sprue and completely separate the two adjacent products.

[0014] In a preferred embodiment, the sliding mechanism includes a sliding seat and a shovel, the sliding seat being slidably disposed in the horizontal direction, and the shovel driving the sliding seat to open or close.

[0015] In a preferred embodiment, in step S4, the product and the sprue are first ejected by the rear mold ejection mechanism, and then sorted and removed by the robot arm; the pressing mechanism is reset first, and the rear mold ejection mechanism is reset later.

[0016] In a preferred embodiment, an inductive switch is provided between the pressing mechanism and the rear mold ejection mechanism. After the inductive switch detects the reset signal of the pressing mechanism, the rear mold ejection mechanism begins to reset.

[0017] Secondly, the present invention provides an in-mold pressing mechanism for a product, which adopts the in-mold assembly method described above. The device includes a mold cavity, which is used for connecting the sprue between the molded product and adjacent products. The product corresponding to the mold cavity includes buckles and slots arranged along the product height direction.

[0018] The mold cavity is provided with a front mold mechanism, a rear mold mechanism, and a sliding mechanism. The sliding mechanism surrounds the horizontal direction of the mold cavity, and the front mold mechanism and the rear mold mechanism respectively surround the upper and lower sides of the mold cavity.

[0019] The front mold mechanism is equipped with a pressing mechanism, which is used to press the product so that the buckle engages with the slot.

[0020] In a preferred embodiment, the front mold mechanism includes a front template and a front mold ejector plate. The pressing mechanism is nested on the front mold mechanism. The pressing mechanism includes a hydraulic cylinder and a front mold ejector insert. The hydraulic cylinder is fixed to the front template, and the driving end of the hydraulic cylinder is connected to the front mold ejector plate. The front mold ejector insert is fixed to the front mold ejector plate. The hydraulic cylinder drives the front mold ejector plate to move the front mold ejector insert longitudinally upward to push the product to complete the pressing.

[0021] In a preferred embodiment, the sliding mechanism includes a sliding seat and a shovel. The sliding seat is slidably disposed between the front mold mechanism and the rear mold mechanism in a horizontal direction, and the shovel drives the sliding seat to open or close.

[0022] In a preferred embodiment, the mold cavity is further provided with a sprue insert, which is used to form the connecting sprue, and the sprue insert moves longitudinally to break off the connecting sprue from the product.

[0023] In a preferred embodiment, the product is a shell structure with thin walls. The buckle protrudes from the inner wall of the shell structure, and the slot is recessed into the inner wall of the shell structure. The buckle includes a guide slope and a barb, and the slot includes an inlet section and an engagement section. When the pressing mechanism pushes the product, the thin wall of the shell structure undergoes slight elastic deformation, causing the guide slope to engage with the inlet section. After the barb passes the engagement section, the shell structure elastically rebounds, and the barb locks into the engagement section.

[0024] According to the above-described solution, the beneficial effects of this invention are as follows:

[0025] Compared to existing technologies that involve multiple product transfers, this application integrates injection molding, press fitting, and sprue treatment into a single standard three-plate mold at the same workstation. After the mold is closed and the integral injection molded part is formed, the mold is opened directly, eliminating the need for multiple product transfers between the injection molding machine, rotary table, press fitting equipment, and sprue cutting mechanism. This reduces waiting and transfer time between processes. It also eliminates the need for additional equipment such as rotary tables, dedicated press fitting equipment, and sprue cutting equipment, and allows the press fitting action to be completed inside the mold cavity. The product is directly positioned by the mold cavity, avoiding positioning deviations during manual assembly or external press fitting, and ensuring press fitting accuracy. After the product is press-fitted inside the mold, it is ejected and unloaded, reducing damage such as bumps and deformation that may be caused during multiple transfers and clamping processes. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the three-dimensional assembly structure of the front mold mechanism and the rear mold mechanism of the present invention.

[0027] Figure 2 This is a cross-sectional view of the mold cavity of the present invention.

[0028] Figure 3 This is a three-dimensional structural diagram of the front mold mechanism of the present invention.

[0029] Figure 4 This is a three-dimensional structural diagram of the positioning mechanism of the present invention.

[0030] Figure 5This is a three-dimensional structural diagram of the pressing mechanism of the present invention.

[0031] Figure 6 for Figure 5 A partially enlarged structural diagram of the medium-pressure column.

[0032] Figure 7 This is a three-dimensional structural diagram of the one-piece injection molded part of the present invention.

[0033] Figure 8 This is a three-dimensional structural diagram of the product of the present invention.

[0034] Figure 9 for Figure 8 A partial cross-sectional view of the product shown.

[0035] Figure 10 This is a cross-sectional structural diagram of the two products and the sprue of the present invention.

[0036] In the diagram, 1. Product; 11. Front mold base plate; 12. Rear mold top plate; 13. Press-fit groove; 14. Hook; 15. Slot;

[0037] 2. Front mold mechanism;

[0038] 3. Rear mold mechanism; 31. Rear mold cavity; 311. Groove on product; 312. Sprue groove;

[0039] 4. Pressing mechanism; 41. Pressing cylinder; 42. Pressing top plate; 43. Pressing column; 431. Pressing groove; 51. First sprue insert; 511. Sprue drive plate; 52. Product insert; 521. Product drive seat; 53. Second sprue insert;

[0040] 6. Sliding seat; 61. Front mold channel; 62. Scraper; 631. Lateral limiting slope; 64. Clip.

[0041] 7. Connecting sprue; 71. Sprue cone; 72. Connecting section. Detailed Implementation

[0042] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification and claims of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0044] Please refer to Figure 8 and Figure 9 In this embodiment, Product 1 is a plastic snap-fit ​​component. Product 1 includes a front mold base plate 11, a rear mold top plate 12, and a columnar body connecting the front mold base plate 11 and the rear mold top plate 12. The outer wall of the columnar body is provided with a hook 14. The upper inner side of the elastic snap-fit ​​foot of the rear mold top plate 12 is provided with a snap-fit ​​groove 15. The hook 14 and the snap-fit ​​groove 15 are arranged opposite to each other along the product height direction. The lower end of the rear mold top plate 12 is also provided with an elastic snap-fit ​​foot. The elastic snap-fit ​​feet are evenly distributed circumferentially for elastic engagement with the mounting base plate.

[0045] In the initial injection molding state of Product 1, the front mold base plate 11, the rear mold top plate 12, the columnar body, and the elastic retaining feet are integrally formed, but there is a gap between the retaining hook 14 and the retaining groove 15, and it is in an unpressurized state. Through the subsequent pressing action, the columnar body moves upward relative to the rear mold top plate 12, so that the retaining hook 14 is embedded into the inside of the retaining groove 15 and latches, completing the self-pressurization of Product 1.

[0046] Please refer to Figure 7 After injection molding, a monolithic injection molded part is formed within the mold cavity. The monolithic injection molded part includes multiple products 1 and a connecting sprue 7 connecting two adjacent products 1. The connecting sprue 7 includes a sprue cone portion 71 and a connecting portion 72. The sprue cone portion 71 is connected to the outer wall of the columnar body of the product 1, and the connecting portion 72 connects two adjacent sprue cone portions 71 into one unit, so that multiple products 1 are connected in a row through the connecting sprue 7.

[0047] Please refer to Figures 1 to 5 This embodiment provides an in-mold pressing mechanism for a product, employing the aforementioned in-mold assembly method. The device includes a mold cavity, which is used to form a sprue 7 between the molded product 1 and adjacent products 1. The mold cavity is equipped with a front mold mechanism 2, a rear mold mechanism 3, and a sliding seat 6. The sliding seat 6 surrounds the horizontal direction of the mold cavity, and the front mold mechanism 2 and the rear mold mechanism 3 respectively surround the upper and lower sides of the mold cavity.

[0048] The front mold mechanism 2 includes a front template, and the rear mold mechanism 3 includes a rear template and a rear mold cavity 31. The rear mold cavity 31 is provided with a product groove 311 and a sprue groove 312. The product groove 311 is used to form the rear mold top plate 12 and the elastic retaining foot of the product 1, and the sprue groove 312 is used to form the sprue cone 71 of the connecting sprue 7.

[0049] Please refer to Figure 5 and Figure 6 The pressing mechanism 4 is nested and installed on the front mold mechanism 2. The pressing mechanism 4 includes a pressing cylinder 41, a pressing top plate 42, and a pressing column 43. The pressing cylinder 41 is fixed to the front template of the front mold mechanism 2, and the driving end of the pressing cylinder 41 is connected to the pressing top plate 42. The pressing column 43 is fixed to the pressing top plate 42, and the pressing column 43 is provided with a pressing groove 431. The movement of the pressing column 43 is guided by a guide structure to ensure the accuracy of longitudinal movement.

[0050] The pressing cylinder 41 drives the pressing top plate 42 to move the pressing column 43 longitudinally upward. The pressing column 43 extends into one side of the mold cavity and applies a longitudinal upward thrust to the front mold base plate 11 of product 1, pushing the columnar body upward relative to the rear mold top plate 12, so that the hook 14 is inserted into the inside of the slot 15 and engaged, completing the self-pressing of product 1.

[0051] A spring is provided between the pressing top plate 42 and the front template to drive the pressing top plate 42 to reset after pressing is completed, ensuring that the pressing mechanism 4 accurately returns to its initial position.

[0052] Please refer to Figure 3 and Figure 4 The slide seat 6 is provided with a front mold channel 61. The scraper 62 is fixed on the front mold mechanism 2. The scraper 62 is provided with a transverse limiting slope 631. The slide seat 6 is slidably disposed between the front mold mechanism 2 and the rear mold mechanism 3 in the horizontal direction. When the mold is opened, the front mold mechanism 2 moves upward, and the transverse limiting slope 631 of the scraper 62 cooperates with the slope of the slide seat 6, driving the slide seat 6 to slide outward in the horizontal direction and open the horizontal direction of the mold cavity, making room for pressing. The pressing column 43 can pass through the front mold channel 61 and extend into the mold cavity.

[0053] The slide seat 6 is also equipped with a locking nut 64, which is used to control the mold opening sequence and ensure that the core pulling action of the rear mold mechanism 3 is completed before the opening action of the front mold mechanism 2.

[0054] Please refer to Figure 2 The rear mold mechanism 3 is equipped with a pre-extraction mechanism that is guided away by guide pillars. When the mold opens to the set stroke, the pre-extraction mechanism guides the product out along the guide pillars, so that the rear mold cavity 31 opens first, creating space for subsequent pressing.

[0055] Please refer to Figure 2 and Figure 3The mold cavity is also provided with a first sprue insert 51 and a product insert 52. The first sprue insert 51 is fixed on the sprue drive plate 511, and the product insert 52 is fixed on the product drive seat 521. The first sprue insert 51 and the product insert 52 are arranged longitudinally. The first sprue insert 51 is used to form the connecting part 72, and the product insert 52 is used to form the columnar body of the product 1 and the front mold base plate 11. The mold cavity is also provided with a second sprue insert 53. The second sprue insert 53 is arranged corresponding to the connecting part 72 and is used to break off the connecting sprue 7 from the product during demolding.

[0056] Before pressing, the first sprue insert 51 can move longitudinally upwards to break off the connecting sprue 7 from the product 1, thus completely separating two adjacent products 1.

[0057] Please refer to Figure 2 and Figure 10 After injection molding, the columnar body of product 1 is located on one side of the front mold mechanism 2, the rear mold top plate 12 and the elastic retaining foot are located on one side of the rear mold mechanism 3, the retaining hook 14 and the retaining groove 15 are in an unfitted state, and the sprue 7 connects between two adjacent products 1.

[0058] During mold opening, the first extraction mechanism of the rear mold mechanism 3 is guided away by the guide pillars, and the rear mold cavity 31 opens to the set stroke. Then, the front platen of the front mold mechanism 2 and the rear platen of the rear mold mechanism 3 open. At the same time, the slide seat 6 opens laterally under the drive of the shovel 62, opening the mold cavity horizontally and making room for pressing.

[0059] Subsequently, the first sprue insert 51 moves upward, breaking the connecting sprue 7 and completely separating the two adjacent products 1. Then, the pressing cylinder 41 drives the pressing top plate 42 to move the pressing column 43 longitudinally upward. The pressing column 43 applies an upward thrust to the front mold base plate 11 of product 1, pushing the columnar body upward relative to the rear mold top plate 12. During this process, the hook 14 moves upward and engages with the inside of the slot 15, completing the self-pressing of product 1.

[0060] After pressing is completed, the ejector pins of the rear mold ejection mechanism eject the pressed product 1 and the sprue 7. The robot then sorts and removes product 1 and the sprue material.

[0061] An inductive switch is provided between the pressing mechanism 4 and the rear mold ejection mechanism. The inductive switch detects the reset signal of the pressing top plate 42. After pressing is completed, the pressing top plate 42 is reset first under the action of the spring. After the inductive switch confirms that the pressing mechanism 4 is fully reset, the rear mold ejection mechanism begins to reset, and all moving parts return to their initial positions to prepare for the next cycle.

[0062] The in-mold pressing mechanism provided in this application embodiment can perform the above method embodiment. Its implementation principle and technical effect are similar, and will not be repeated here. Those skilled in the art can understand that various aspects of the present invention can be implemented as a system, method or program product.

[0063] Furthermore, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0064] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

[0065] The present invention has been described above with reference to the accompanying drawings. Obviously, the implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for in-mold assembly of a product, using an injection mold, characterized in that, Includes the following steps: S1. Injection molding: Molten plastic is injected into the mold cavity to form a one-piece injection molded part. The one-piece injection molded part includes at least two products and a sprue connecting two adjacent products. The products are provided with buckles and slots. S2, Horizontal mold opening: Drive the sliding mechanism to open, making the mold cavity open horizontally, and making room for pressing; S3, In-mold pressing: The driving pressing mechanism extends longitudinally into one side of the mold cavity to apply longitudinal pressure to the product, so that the buckle and the slot are correspondingly engaged to complete the pressing of the product itself; S4. Ejection and unloading: Eject the pressed product and the connecting sprue to complete the unloading.

2. The in-mold assembly method for a product according to claim 1, characterized in that, Step S3 is preceded by: Sprue detachment step: Drive the sprue insert pin to break the connecting sprue and completely separate the two adjacent products.

3. The in-mold assembly method for a product according to claim 1, characterized in that, The locating mechanism includes a locating seat and a shovel. The locating seat is slidably arranged in the horizontal direction, and the shovel drives the locating seat to open or close.

4. The in-mold assembly method for a product according to claim 1, characterized in that, In step S4, the product and the sprue are first ejected by the rear mold ejection mechanism, and then sorted and removed by the robot arm; the pressing mechanism is reset first, and the rear mold ejection mechanism is reset later.

5. The in-mold assembly method for a product according to claim 4, characterized in that, An inductive switch is provided between the pressing mechanism and the rear mold ejection mechanism. After the inductive switch detects the reset signal of the pressing mechanism, the rear mold ejection mechanism begins to reset.

6. An in-mold pressing mechanism for a product, characterized in that: The in-mold assembly method for products as described in any one of claims 1-5, wherein the apparatus includes a mold cavity, the mold cavity being used for connecting sprues between the molded product and adjacent products; The product corresponding to the mold cavity includes buckles and slots arranged along the product height direction; The mold cavity is provided with a front mold mechanism, a rear mold mechanism, and a sliding mechanism. The sliding mechanism surrounds the horizontal direction of the mold cavity, and the front mold mechanism and the rear mold mechanism respectively surround the upper and lower sides of the mold cavity. The front mold mechanism is equipped with a pressing mechanism, which is used to press the product so that the buckle engages with the slot.

7. The in-mold pressing mechanism according to claim 6, characterized in that, The front mold mechanism includes a front template and a front mold ejector plate. The pressing mechanism is nested on the front mold mechanism. The pressing mechanism includes a hydraulic cylinder and a front mold ejector insert. The hydraulic cylinder is fixed on the front template. The driving end of the hydraulic cylinder is connected to the front mold ejector plate. The front mold ejector insert is fixed on the front mold ejector plate. The hydraulic cylinder drives the front mold ejector plate to move the front mold ejector insert longitudinally upward to push the product to complete the pressing.

8. The in-mold pressing mechanism according to claim 6, characterized in that, The sliding mechanism includes a sliding seat and a shovel. The sliding seat is slidably disposed between the front mold mechanism and the rear mold mechanism in a horizontal direction. The shovel drives the sliding seat to open or close.

9. The in-mold pressing mechanism according to claim 6, characterized in that, The mold cavity is also provided with a sprue insert, which is used to form the continuous sprue, and the sprue insert moves longitudinally to break off the continuous sprue from the product.

10. The in-mold pressing mechanism according to claim 6, characterized in that, The product is a shell structure with thin walls. The buckle protrudes from the inner wall of the shell structure, and the slot is recessed into the inner wall of the shell structure. The buckle includes a guide slope and a barb, and the slot includes an inlet section and an engagement section. When the pressing mechanism pushes the product, the thin wall of the shell structure undergoes slight elastic deformation, causing the guide slope to engage with the inlet section. After the barb passes the engagement section, the shell structure elastically rebounds, and the barb locks into the engagement section.

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