In-mold punching injection mold

Abstract

The invention relates to an in-mold punching injection mold which comprises an upper mold body and a lower mold body, the lower mold body is provided with a fixed mold insert for placing a membrane, and the upper mold body is provided with a movable mold insert relatively matched with the fixed mold insert. A plurality of sliding blocks capable of sliding are arranged on the fixed mold insert, and a positioning column is arranged on each sliding block and used for penetrating through a positioning hole in a diaphragm to realize initial positioning of the diaphragm. In the mold closing process, the ejector rod on the movable mold insert pushes the sliding block to slide, so that the positioning column is driven to move, and a membrane is tensioned and positioned; and then the convex parts on the movable mold insert and the fixed mold insert are matched with the grooves, so that synchronous punching and injection molding of the membrane are realized. According to the invention, in-mold automatic positioning, tensioning and punching forming of the diaphragm are realized, errors of manual cutting and manual film pasting are avoided, the positioning precision and forming efficiency of the diaphragm are improved, and the device is suitable for injection molding scenes of diaphragm inserts such as vehicle-mounted displays and electronic panels, and has relatively high automation suitability and industrial application value.

Description

Technical Field

[0001] The present application relates to the technical field of injection molds, and in particular to an in-mold punching injection mold. Background Art

[0002] In injection molding processes like in-mold decoration (IMD) and in-mold labeling (IML), membranes serve as functional exterior components, pattern carriers, or functional cover films. They are widely used in applications such as home appliance panels, automotive center consoles, and electronic product housings. To achieve a tight integration of the pattern and the plastic component, the membrane must be accurately positioned within the mold cavity before injection molding and maintain a tight fit without deformation.

[0003] In the existing technology, most diaphragms are produced by "out-of-mold punching + manual sheeting" or "out-of-mold punching + robot sheeting". The typical process includes: 1. During the diaphragm pre-processing stage, a stamping die is used to cut the large-sized diaphragm into the required contour; 2. Place the cut diaphragm on the fixed or movable mold of the mold manually or by equipment; 3. After injection molding is completed, take out the finished product.

[0004] The above method has the following defects: 1. Since the cutting and positioning of the diaphragm are separate processes, the positioning error is large, which can easily lead to problems such as warping, offset, and breakage; 2. The diaphragm is exposed outside the mold for a long time, which easily absorbs impurities and dust, affecting the molding quality; 3. Cutting, conveying, and placing are multiple links connected in series, which seriously limits the degree of automation; 4. To ensure positioning accuracy, it is often necessary to configure high-precision cutting devices, swing mechanisms, vacuum suction cups and other auxiliary equipment, which is very expensive; 5. If the diaphragm is not fully tensioned during the injection molding process, it is easy to move due to thermal expansion and contraction of the material or mold closing impact, affecting the appearance or functional consistency.

[0005] Some existing technologies attempt to integrate the diaphragm positioning function inside the mold, but there are common problems such as complex structure, difficult debugging, inability to achieve tensioning or poor punching quality, and it is still difficult to meet the industry demand for high-quality and high-efficiency in-mold molding. Summary of the Invention

[0006] The present application provides an in-mold punching injection mold, which can complete the automatic positioning, tensioning and punching operations of the diaphragm during the mold closing process.

[0007] The in-mold punching injection mold provided in the present application includes an upper mold body and a lower mold body. The upper mold body includes a movable mold plate, on which a movable mold insert is provided. The lower mold body includes a fixed mold plate, on which a fixed mold insert is provided. After the mold is closed, a mold cavity is formed between the fixed mold insert and the movable mold insert. The upper surface of the fixed mold insert is used to place the diaphragm, the fixed mold insert is provided with a first matching portion, and the movable mold insert is provided with a second matching portion; The fixed mold insert is provided with a plurality of sliders spaced around the mold cavity, each slider being capable of sliding toward or away from the mold cavity, and each slider being provided with a positioning post for passing through a positioning hole on the diaphragm to initially position the diaphragm; During the mold closing process, the movable mold insert contacts and engages with all the sliders, pushing the sliders to slide from their initial positions in a direction away from the mold cavity, thereby driving the plurality of positioning pins to tension and position the diaphragm. Subsequently, the mold is closed continuously, and the first mating portion and the second mating portion cooperate to punch the diaphragm into a shape that matches the bottom surface and side walls of the mold cavity. Each slider is equipped with an elastic reset member for resetting the slider to an initial position, and the elastic reset member is arranged between the slider and the fixed mold insert.

[0008] Preferably, the fixed mold insert is provided with a plurality of slide grooves distributed around the mold cavity, each slide groove extends toward or away from the mold cavity, and a plurality of sliders are respectively slidably arranged in the plurality of slide grooves.

[0009] Preferably, the elastic return member is a compression spring, one end of the compression spring abuts against the end of the slider away from the mold cavity, and the other end of the compression spring abuts against the end of the slide groove away from the mold cavity.

[0010] Preferably, each slider is provided with a through hole extending through the slider along its thickness direction, and the through hole has an inclined surface arranged along the thickness direction of the slider. The movable mold insert is provided with a plurality of push rods for pushing the slider. When the mold is closed, the plurality of push rods respectively contact the inclined surfaces on the plurality of sliders to push the slider to slide in the slide groove in a direction away from the mold cavity.

[0011] Preferably, each positioning column is fixedly connected to a limiting head, and the bottom surface of each slider is provided with a recess for accommodating the limiting head. Each slider is provided with a plug hole extending from the recess to the top surface, and the plug hole is used to insert the positioning column.

[0012] Preferably, a groove is provided on the upper surface of the fixed mold insert, the first matching part is the groove wall of the groove, and a convex part is provided on the lower surface of the movable mold insert, the second matching part is the peripheral wall of the convex part. After the mold is closed, the groove and the convex part cooperate to form a mold cavity, and the peripheral wall of the convex part and the groove wall of the groove cooperate and contact with each other to cut the diaphragm.

[0013] The present invention provides an in-mold punching injection mold. By providing a plurality of slidable sliders and positioning posts on the fixed mold insert, the movable mold insert can be used to push the diaphragm to achieve tensioning and positioning, and the in-mold punching of the diaphragm is completed during the mold closing process. The mold has the following technical effects and significant advantages: 1. The present invention adopts a slidable slider in conjunction with the positioning posts on it to achieve positioning of the diaphragm. The diaphragm is pre-set with positioning holes. The initial positioning of the diaphragm is completed by inserting the positioning posts into the positioning holes. During the mold closing process, the movable mold insert pushes the slider to slide in the direction away from the mold cavity, thereby driving the multiple positioning posts to stretch the diaphragm outward to achieve tension positioning. Compared with the positioning methods in the prior art that use manual swinging, vacuum adsorption, etc., the automatic positioning structure of the present invention can significantly improve the accuracy and repeatability of positioning, effectively preventing the diaphragm from deflecting, wrinkling, and other problems caused by factors such as thermal expansion and contraction and mold closing impact, thereby ensuring the aesthetics and functional consistency of the injection molded product. 2. The present invention provides a push rod structure on the movable mold insert. During the mold closing process, the push rod contacts the inclined surface of the slider, pushing the slider to slide outward, so that a tensioning effect is formed between the positioning column on the slider and the diaphragm positioning hole. This tensioning positioning method does not require an additional servo system or tensioning drive device, has a simpler structure and higher response synchronization. At the same time, it is naturally synchronized with the mold closing behavior, and the tensioning force is uniform and controllable, which can ensure that the diaphragm fits the mold cavity during injection molding, with a flat surface, free of bubbles and wrinkles, thereby improving the yield rate and appearance consistency. 3. The present invention utilizes the cooperation between the convex portion (second cooperation portion) on the movable mold insert and the concave portion (first cooperation portion) on the fixed mold insert to punch out the diaphragm when the mold is closed to the end point after the diaphragm is tensioned. This process can complete the punching before the diaphragm comes into contact with the molten plastic, thereby realizing the integrated operation of in-mold positioning, punching, and injection molding. Compared with the traditional outside-mold punching + manual or automatic swinging method, this solution greatly reduces the operating steps, improves the degree of automation, saves diaphragm conveying equipment and cutting processes, and avoids product defects caused by burrs on the diaphragm edges or poor cutting. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic structural diagram of an in-mold punching injection mold according to an embodiment of the present invention; Figure 2 A top view of an in-mold punching injection mold according to an embodiment of the present invention; Figure 3 for Figure 2 AA section view in the figure; Figure 4 for Figure 3 Enlarged view of area A in the middle; Figure 5This is a schematic diagram of the product structure of the injection molding using the in-mold punching injection mold according to an embodiment of the present invention.

[0015] Explanation of the accompanying reference numerals: 1. Upper mold body; 2. Lower mold body; 10. Moving mold plate; 11. Moving mold insert; 111. Positioning hole; 112. Ejector rod; 12. Protrusion; 121. Outer peripheral wall; 122. Inner peripheral wall; 20. Fixed mold plate; 21. Fixed mold insert; 211. Slide groove; 212. Slider; 213. Positioning column; 2131. Limiting head; 214. Through hole; 215. Inclined surface; 216. Compression spring; 217. Insert; 22. Groove; 221. Outer ring groove wall; 222. Inner ring groove wall; 30. Diaphragm; 31. Diaphragm positioning hole; 40. Injection molded part. DETAILED DESCRIPTION

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0017] like Figures 1 to 4 As shown, the in-mold punching injection mold provided in this embodiment includes an upper mold body 1 and a lower mold body 2. The upper mold body 1 includes a movable mold plate 10, on which a movable mold insert 11 is provided; the lower mold body 2 includes a fixed mold plate 20, on which a fixed mold insert 21 is provided. After the mold is closed, the fixed mold insert 21 and the movable mold insert 11 enclose a mold cavity.

[0018] Diaphragm 30 is the target material to be cut and injection-molded. Initially, it is laid flat on the upper surface of fixed mold insert 21, where it is subsequently combined with the molded part to form the in-mold injection structure. Diaphragm 30 is provided with multiple diaphragm positioning holes 31, which mate with positioning posts 213 in the lower mold to achieve initial positioning and rough positioning of the diaphragm before the mold is initially closed.

[0019] The fixed mold insert 21 is provided with a plurality of chute slots 211 spaced circumferentially around the mold cavity. A slider 212 is slidably mounted within each chute 211, allowing reciprocating movement within the slot 211 in directions toward or away from the mold cavity. Each slider 212 is provided with an upwardly extending positioning post 213, which passes through a diaphragm positioning hole 31 in the diaphragm to provide preliminary positioning of the diaphragm 30 prior to initial mold closing.

[0020] In order to ensure that the positioning column 213 has a stable and reliable structure, a limiting head 2131 is fixedly connected to the lower part of each positioning column 213. The limiting head 2131 is inserted into the recess set on the bottom surface of the slider 212, and the positioning column 213 is inserted into the plug-in hole that passes through the recess to the top surface of the slider 212, forming a limiting connection method with stable structure and convenient assembly.

[0021] A plurality of positioning holes 111 are provided on the movable mold insert 11, and their positions correspond one-to-one to a plurality of positioning posts 213. During further mold closing, the positioning posts 213 are inserted into the corresponding positioning holes 111 to realize axial matching positioning between the diaphragm and the upper mold, thereby enhancing the stability of the diaphragm 30.

[0022] To achieve automatic tensioning of the diaphragm 30, each slider 212 is provided with a through-hole 214 extending through its thickness. Each through-hole 214 is provided with an inclined surface 215 arranged along the thickness. Multiple ejector pins 112 are positioned beneath the movable mold insert 11. During the mold closing process, these ejector pins 112 sequentially penetrate the through-holes 214 of the sliders 212 and initially contact the inclined surfaces 215. As the mold continues to close, the pressure from the ejector pins 112 drives the inclined surfaces 215, causing the sliders 212 to slide from their initial position along the chute 211 away from the mold cavity. This, in turn, drives the positioning posts 213 thereon to move outward synchronously, achieving multi-point, synchronized tensioning and positioning of the diaphragm 30. When the sliders 212 are in their initial position, they abut against the end of the chute 211 closest to the mold cavity. Subsequently, the ejector rod 112 continues to pass downward through the through hole 214 and is inserted into the insertion hole 217 provided on the fixed mold insert 21 , further limiting the slider 212 and the ejector rod 112 .

[0023] To ensure that the slider 212 returns to its initial position after injection molding is complete, an elastic reset member, preferably a compression spring 216, is provided between each slider 212 and its corresponding chute 211. One end of the compression spring 216 abuts the end of the slider 212 facing away from the mold cavity, while the other end abuts the end of the inner wall of the chute 211. After the mold is opened, the compression spring 216 releases its prestressed force, automatically returning the slider 212 and its positioning post 213 to their initial position, preparing the initial state for the next die placement and punching operation. This reset mechanism does not rely on external drive, is simple in structure, responds quickly, and offers excellent durability and ease of maintenance.

[0024] The upper surface of the fixed mold insert 21 is provided with a groove 22 for matching punching, and the lower surface of the movable mold insert 11 is provided with a matching convex portion 12. In the final mold closing state, the convex portion 12 and the groove 22 cooperate to enclose a mold cavity for injection molding.

[0025] Furthermore, the groove 22 comprises an annular outer groove wall 221 and an inner groove wall 222, while the protrusion 12 comprises a mating outer peripheral wall 121 and an inner peripheral wall 122. During mold closing, the outer peripheral wall 121 and the outer groove wall 221 form shearing surfaces for cutting the outer contour of the diaphragm 30; the inner peripheral wall 122 and the inner groove wall 222 form a second set of shearing surfaces for simultaneously cutting the functional holes or window areas in the diaphragm. This structure enables simultaneous punching of the diaphragm's outer periphery and inner holes. After molding, the diaphragm's shape closely matches the mold cavity contour, achieving a good fit and reducing post-processing steps.

[0026] like Figure 5 As shown, the product molded using this mold includes an injection molded part 40 and a diaphragm 30 covering its lower surface, outer peripheral wall, and the inner wall of the functional hole. In this embodiment, the diaphragm 30 has two functional holes, correspondingly provided with two sets of inner ring groove walls 222 and inner peripheral walls 122, enabling precise punching and forming of the functional holes. This product has a high degree of integration, a complete structure, and good surface consistency.

[0027] The advantages of the in-mold punching injection mold of this embodiment are as follows: 1. The slider 212-rod 112 structure enables the diaphragm 30 to be tensioned and positioned at multiple points within the mold, ensuring that the diaphragm 30 remains flat and fits well during molding, avoiding problems such as wrinkles and displacement, and significantly improving molding consistency and appearance quality. 2. The mold's built-in shear structure (convex portion 12 and concave groove 22) is used to simultaneously complete the outer contour of the diaphragm 30 and the punching of the functional holes, eliminating the early cutting and laminating processes, reducing manual intervention, and achieving true in-mold integration; 3. The sliders 212 and the slide grooves 211 are modular structures. The number and arrangement of the sliders 212 and the spacing between the positioning posts 213 can be flexibly adjusted to accommodate diaphragms of different sizes and shapes. This supports multi-product co-modular design and is suitable for various scenarios such as automotive accessories, electronic panels, and smart housings. 4. The mold structure supports continuous feeding of diaphragm 30 (such as coil material), robot loading and automatic punching and injection molding, seamlessly integrated with industrial automation equipment, and can be widely used in automated production lines in the field of high-end manufacturing; 5. All sliders 212, compression springs 216, and positioning posts 213 are centrally arranged inside the fixed mold insert 21 to avoid interference with the main injection cavity. The slider 212 returns to its original position using elastic prestressed reset, without the need for electrical control or pneumatic drive. The structure is stable and easy to maintain.

[0028] This specification and drawings are merely illustrative of the present application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Obviously, those skilled in the art may make various modifications and variations to this application without departing from the scope of this application. Thus, this application is intended to include such modifications and variations as fall within the scope of this application and its equivalents.

Claims

1. An in-mold punching injection mold, characterized in that: The mold comprises an upper mold body (1) and a lower mold body (2), wherein the upper mold body (1) comprises a movable mold plate (10), and a movable mold insert (11) is provided on the movable mold plate (10); the lower mold body (2) comprises a fixed mold plate (20), and a fixed mold insert (21) is provided on the fixed mold plate (20); after the mold is closed, a mold cavity is formed between the fixed mold insert (21) and the movable mold insert (11); The upper surface of the fixed mold insert (21) is used for placing a diaphragm, the fixed mold insert (21) is provided with a first matching portion, and the movable mold insert (11) is provided with a second matching portion; The fixed mold insert (21) is provided with a plurality of sliders (212) spaced apart around the mold cavity, each slider (212) being capable of sliding in a direction toward or away from the mold cavity, and each slider (212) is provided with a positioning post (213) for passing through a positioning hole on the diaphragm to initially position the diaphragm; The movable mold insert (11) contacts with all the sliders (212) during the mold closing process and pushes the sliders (212) to slide from the initial position in a direction away from the mold cavity, thereby driving the plurality of positioning columns (213) to tension and position the diaphragm; the mold is then closed, and the first matching portion and the second matching portion cooperate to punch the diaphragm into a shape that matches the bottom surface and side wall of the mold cavity; Each slider (212) is equipped with an elastic reset member for resetting the slider (212) to an initial position, and the elastic reset member is arranged between the slider (212) and the fixed mold insert (21).

2. The in-mold punching injection mold according to claim 1, characterized in that: The fixed mold insert (21) is provided with a plurality of slide grooves (211) distributed around the mold cavity, each slide groove (211) extending in a direction toward or away from the mold cavity, and a plurality of sliders (212) are respectively slidably arranged in the plurality of slide grooves (211).

3. The in-mold punching injection mold according to claim 2, characterized in that: The elastic return member is a compression spring (216), one end of the compression spring (216) abuts against the end of the slider (212) away from the mold cavity, and the other end of the compression spring (216) abuts against the end of the slide groove (211) away from the mold cavity.

4. The in-mold punching injection mold according to claim 2, characterized in that: Each slider (212) is provided with a through hole (214) extending through the slider (212) in the thickness direction thereof, and the through hole (214) has an inclined surface (215) provided in the thickness direction of the slider (212). The movable mold insert (11) is provided with a plurality of push rods (112) for pushing the sliders (212). When the mold is closed, the plurality of push rods (112) respectively contact the inclined surfaces (215) on the plurality of sliders (212) to push the sliders (212) to slide in the chute (211) in a direction away from the mold cavity.

5. The in-mold punching injection mold according to claim 2, characterized in that: Each positioning column (213) is fixedly connected to a limiting head (2131), and a recess for accommodating the limiting head (2131) is provided on the bottom surface of each slider (212). Each slider (212) is provided with a plug hole extending from the recess to the top surface, and the plug hole is used to insert and pass through the positioning column (213).

6. The in-mold punching injection mold according to any one of claims 1 to 5, characterized in that: The upper surface of the fixed mold insert (21) is provided with a groove (22), the first matching portion is the groove wall of the groove (22), the lower surface of the movable mold insert (11) is provided with a convex portion (12), the second matching portion is the peripheral wall of the convex portion (12), after the mold is closed, the groove (22) and the convex portion (12) cooperate to form a mold cavity, and the peripheral wall of the convex portion (12) and the groove wall of the groove (22) cooperate and contact with each other to cut the diaphragm.

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