A secondary core pulling mechanism and core pulling method for a slider of an injection mold

Abstract

The present invention discloses a secondary core pulling mechanism and a core pulling method for a slider of an injection mold. The core pulling mechanism includes a main slider seat, a delayed bending pin, a molding insert, an inner slider, a pull rod and two core pulling inserts. A first slideway adapted to the inner slider is provided inside the main slider seat, and a second slideway is provided inside the molding insert; one end of the pull rod is connected to the inner slider, and the other end of the pull rod is provided with two oblique guide grooves; the core pulling insert is movably arranged in the second slideway, the core pulling insert is slidably matched with the oblique guide groove, and an undercut molding groove is provided at the end of the core pulling insert. In the present invention, both the main slider seat and the inner slider are driven by a single delayed bending pin, and the undercut and simultaneous ejection function in multiple directions can be realized. The driving force is simple and single, the core pulling mechanism runs smoothly, the overall structure is simple, the undercut ejection effect of the injection molded product is good, the investment and use cost of one or more sliders can be saved, the mold space occupation is reduced, the production stability can be improved, and the loss and maintenance costs can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molds, and in particular relates to a secondary core pulling mechanism and a core pulling method for a slider of an injection mold. Background Art

[0002] Injection molds are important process equipment for producing various industrial products. With the rapid development of the plastics industry and the promotion and application of plastic products in aviation, aerospace, electronics, machinery, shipbuilding and automobile industries, the scope of application of injection molds is becoming more and more extensive. Injection molds are a tool for producing plastic products, and are also a tool for giving plastic products a complete structure and precise dimensions. Injection molding is a processing method used in the mass production of certain parts with complex shapes. Specifically, it refers to the high-pressure injection of heated and melted plastic into the mold cavity by the injection molding machine, and after cooling and solidification, a molded product is obtained. In the injection molding process, due to the special requirements of the product, the demoulding direction of a certain part of the product is inconsistent with the mold opening direction of the injection molding machine, that is, the product has undercuts. Except for very rare cases where forced demoulding can be performed, most of the time, lateral parting and core pulling are required to successfully eject the product. The core pulling mechanism is a mold structure developed to solve the problem of undercuts. Its basic principle is to convert the vertical movement of mold opening and closing into horizontal movement.

[0003] For some products with multiple protrusions and undercuts in the ejection direction, existing injection molds are usually difficult to deal with. Most of them have complex structural designs, require the design of multiple drives, and have poor internal operation coordination, resulting in high overall manufacturing costs. Therefore, a new type of core pulling mechanism with low complexity, smooth operation, stable structure and competitiveness is needed to meet the needs of such products. Summary of the invention

[0004] The object of the present invention is to provide a secondary core pulling mechanism and a core pulling method for a slider of an injection mold, so as to solve the above-mentioned problems existing in the prior art.

[0005] In order to achieve the above-mentioned purpose, on the one hand, the present invention adopts the following technical scheme: a secondary core-pulling mechanism of a slider of an injection mold, comprising a main slider seat, a delayed bending pin, a molding insert, an inner slider, a pull rod and two core-pulling inserts, wherein the main slider seat is slidably arranged in the mold cavity of the injection mold, and a first slideway adapted to the inner slider is arranged inside the main slider seat; one end of the molding insert is connected to the main slider seat, and the other end of the molding insert is provided with a molding surface for forming the side of the injection molded product, and a second slideway is arranged inside the molding insert, and one end of the second slideway is connected to the first slideway, and the other end of the second slideway is provided with an open end extending to the molding surface; the pull rod is slidably arranged in the second slideway, and one end of the pull rod is connected to the inner slider The other end of the pull rod is provided with two oblique guide grooves; the core pulling insert is movably arranged in the second slideway, the core pulling insert is slidably matched with the oblique guide grooves on the surface of the pull rod, and the end of the core pulling insert is provided with an undercut molding groove for molding the injection molded product; the delayed bending pin is inserted on the main slider seat, and the delayed bending pin can drive the inner slider to move with the pull rod in the first core pulling stroke, and the pull rod drives the two core pulling inserts to translate in the second slideway, so that the ends of the two core pulling inserts with undercut molding grooves are close to each other, so that the two undercuts of the injection molded product relative to each other are out of the undercut molding grooves; the delayed bending pin can drive the main slider seat, the molding insert and the two core pulling inserts to move as a whole in the second core pulling stroke, so that the molding surface of the molding insert is away from the injection molded product.

[0006] As an optional implementation of the above technical solution, the end faces of the pull rod and the two core-pulling inserts are flush with the molding surface, so that the end faces of the pull rod and the two core-pulling inserts block the open end.

[0007] As an optional implementation of the above technical solution, the end of the pull rod is provided with two inclined surfaces, and the inclined guide groove is arranged along the inclined surfaces.

[0008] As an optional implementation of the above technical solution, the oblique guide groove is T-shaped.

[0009] As an optional implementation of the above technical solution, the pull rod is L-shaped.

[0010] As an optional implementation of the above technical solution, a strip hole is provided at one end of the core-pulling insert away from the undercut molding groove, and a limit pin is provided in the second slideway, and the limit pin is inserted in the strip hole.

[0011] As an optional implementation of the above technical solution, the molding insert includes a molding insert and a mounting cover plate, and the molding insert and the mounting cover plate are detachably connected.

[0012] As an optional implementation of the above technical solution, a limiting slot is provided at one end of the inner sliding block, and a clamping head adapted to the limiting slot is provided at one end of the pull rod.

[0013] As an optional implementation of the above technical solution, the inner slider is provided with a avoidance hole adapted to the delayed bending pin.

[0014] On the other hand, the present invention adopts the following technical scheme: a core pulling method for the secondary core pulling mechanism of the slider of an injection mold, comprising the following steps: the mold is opened, the delayed bent pin moves vertically upward, the delayed bent pin enters the first core pulling stroke, the delayed bent pin drives the inner slider to move along the first slide, the inner slider moves with the pull rod, the pull rod drives the two core pulling inserts to translate in the second slide, so that the ends of the two core pulling inserts with undercut molding grooves are close to each other, so that the two undercuts relative to the injection molded product are out of the undercut molding grooves, completing the first core pulling; the delayed bent pin continues to move upward, the delayed bent pin enters the second core pulling stroke, the delayed bent pin drives the main slider seat, the molding insert and the two core pulling inserts to move as a whole, so that the molding surface of the molding insert is away from the injection molded product, completing the second core pulling.

[0015] The beneficial effects of the present invention are:

[0016] The present invention does not rely on other external forces when opening the mold. It uses a delayed bending pin to drive the inner slider to move with the pull rod in the first core pulling stroke. The pull rod drives the two core pulling inserts to translate in the second slideway, so that the ends of the two core pulling inserts with the undercut molding grooves are close to each other, so that the two opposite undercuts of the injection molded product are released from the undercut molding grooves; the delayed bending pin drives the main slider seat, the molding insert and the two core pulling inserts to move as a whole in the second core pulling stroke, so that the molding surface of the molding insert is away from the injection molded product. In the present invention, the main slider seat and the inner slider are driven by a single delayed bending pin, which can realize the function of simultaneous release of undercuts in multiple directions. The driving force is simple and single, the core pulling mechanism runs smoothly, the overall structure is simple, the undercut release effect of the injection molded product is good, and the investment and use costs of one or more sliders can be saved, the mold space occupation is reduced, the production stability can be improved, and the loss and maintenance costs can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural schematic diagram of a slider secondary core pulling mechanism in one embodiment of the present invention;

[0018] Figure 2 is an exploded view of a secondary core pulling mechanism of a slider in one embodiment of the present invention;

[0019] Figure 3 is a schematic structural diagram of a molding insert in one embodiment of the present invention;

[0020] Figure 4 is a schematic structural diagram of an inner slider in one embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of a pull rod in one embodiment of the present invention;

[0022] Figure 6 is a schematic structural diagram of an injection molded product in one embodiment of the present invention;

[0023] Figure 7 is a motion state diagram of a delayed bending pin in one embodiment of the present invention;

[0024] Figure 8 It is a motion state diagram of the pull rod and the core-pulling insert in one embodiment of the present invention.

[0025] In the figure: 1-main slider seat; 2-delay bending pin; 3-molding insert; 4-inner slider; 5-pull rod; 6-core-pulling insert; 7-oblique guide groove; 8-undercut molding groove; 9-strip hole; 10-limiting pin; 11-molding insert; 12-installation cover; 13-limiting slot; 14-clamp head; 15-avoidance hole; 16-injection product; 17-undercut. DETAILED DESCRIPTION

[0026] like Figure 1-Figure 8 As shown, this embodiment provides a slider secondary core-pulling mechanism for an injection mold, comprising a main slider seat 1, a delayed bending pin 2, a molding insert 3, an inner slider 4, a pull rod 5 and two core-pulling inserts 6. The main slider seat 1 is slidably arranged in the mold cavity of the injection mold, and a first slideway adapted to the inner slider 4 is provided inside the main slider seat 1. The inner slider 4 is slidably installed in the first slideway, and the inner slider 4 is provided with an avoidance hole 15 adapted to the delayed bending pin 2. The delayed bending pin 2 can drive the inner slider 4 to slide along the first slideway inside the main slider seat 1, and the delayed bending pin 2 can also drive the main slider seat 1 to slide in the mold cavity of the injection mold for demoulding.

[0027] like Figure 1 and Figure 2 As shown, one end of the molding insert 3 is connected to the main slider seat 1 by bolts, and the other end of the molding insert 3 is provided with a molding surface for forming the side of the injection molded product 16. A second slideway is provided inside the molding insert 3, one end of the second slideway is connected to the first slideway, and the other end of the second slideway is provided with an open end extending to the molding surface. The molding insert 3 is connected to the main slider seat 1 as a whole, and the delay bending pin 2 can drive the main slider seat 1 and the molding insert 3 to move together.

[0028] like Figure 5As shown, the pull rod 5 is slidably arranged in the second slideway, one end of the pull rod 5 is connected to the inner slider 4, and the other end surface of the pull rod 5 is provided with two oblique guide grooves 7, and the core-pulling insert 6 is movably arranged in the second slideway, and the two core-pulling inserts 6 are respectively located on both sides of the pull rod 5, and the core-pulling insert 6 is slidably matched with the oblique guide grooves 7 on the surface of the pull rod 5, and the end of the core-pulling insert 6 is provided with an undercut molding groove 8 for molding the injection product 16 undercut 17, and the undercut molding grooves 8 of the two core-pulling inserts 6 are arranged oppositely. When the pull rod 5 moves in the horizontal direction, due to the sliding cooperation of the core-pulling insert 6 with the oblique guide groove 7 on the surface of the pull rod 5, the pull rod 5 can translate with the core-pulling insert 6, so that the ends of the two core-pulling inserts 6 with the undercut molding grooves 8 are close to each other.

[0029] like Figure 7 As shown, the time-delayed bending pin 2 is inserted on the main slider seat 1. When the time-delayed bending pin 2 is driven by the mold to move upward, the time-delayed bending pin 2 enters the first core-pulling stroke, and the time-delayed bending pin 2 drives the inner slider 4 to move with the pull rod 5, and the pull rod 5 drives the two core-pulling inserts 6 to translate in the second slideway, so that the ends of the two core-pulling inserts 6 with the undercut molding grooves 8 are close to each other, so that the two undercuts 17 of the injection molded product 16 are disengaged from the undercut molding grooves 8. When the time-delayed bending pin 2 continues to move upward, the time-delayed bending pin 2 enters the second core-pulling stroke from the first core-pulling stroke, and the time-delayed bending pin 2 can drive the main slider seat 1, the molding insert 3 and the two core-pulling inserts 6 to move as a whole, so that the molding surface of the molding insert 3 is away from the injection molded product 16.

[0030] In a specific embodiment, the end faces of the pull rod 5 and the two core-pulling inserts 6 are flush with the molding surface, so that the end faces of the pull rod 5 and the two core-pulling inserts 6 block the open ends, so that the injection molded product 16 forms a plane and two opposite undercuts 17 are formed on the plane.

[0031] The ends of the pull rod 5 are provided with two inclined surfaces, which are respectively located on both sides of the pull rod 5, and the oblique guide groove 7 is arranged along the inclined surfaces so that the pull rod 5 can drive the two core-pulling inserts 6 to translate in the second slideway. Preferably, the oblique guide groove 7 is T-shaped and the pull rod 5 is L-shaped.

[0032] like Figure 8 As shown, in a specific embodiment, a strip hole 9 is provided at one end of the core-pulling insert 6 away from the undercut molding groove 8, and a limiting pin 10 is provided in the second slideway, and the limiting pin 10 is inserted in the strip hole 9.

[0033] like Figure 3 As shown, as an optional implementation of this embodiment, the molding insert 3 includes a molding insert 11 and a mounting cover plate 12, and the molding insert 11 and the mounting cover plate 12 are detachably connected. The second slideway is arranged in the molding insert 11, and the mounting cover plate 12 is mounted on the molding insert 11 by bolts, which is conducive to the assembly of the brace 5.

[0034] In order to facilitate the assembly of the inner slider 4 and the tie rod 5, a limit slot 13 is provided at one end of the inner slider 4, and a clamping head 14 adapted to the limit slot 13 is provided at one end of the tie rod 5. By clamping the clamping head 14 of the tie rod 5 into the limit slot 13, the assembly of the inner slider 4 and the tie rod 5 can be completed quickly, thereby improving the assembly efficiency.

[0035] The main slider seat 1 and the delayed bending pin 2 of the present invention are common components of the injection mold. The inner slider 4 is a core-pulling mechanism connection and driving part, which is installed in the main slider seat 1. The front end is connected to the pull rod 5, which is driven by the delayed bending pin 2 and limited by the limiting glass beads and the limiting screws. The molding insert 3 is connected to the main slider seat 1 by fixing bolts to form a whole. The inner slider 4 and the pull rod 5 are connected to form a movable main body to drive the core-pulling insert 6 to move. The front end of the molding insert 3 is the molding surface of the injection molded product 16, which is used to form the side of the injection molded product 16. The molding insert 3 includes a molding insert 11 and an installation cover 12, and the installation cover 12 covers the core-pulling insert 6. The pull rod 5 has an oblique guide groove 7, which provides a position for installing the core-pulling insert 6. The core-pulling insert 6 is driven to translate through the oblique guide groove 7 to achieve demolding of the undercut 17. The head of the core-pulling insert 6 is a product glue position with an undercut molding groove 8, and the tail of the core-pulling insert 6 has a strip hole 9, which cooperates with the limit pin 10 to limit the movement of the core-pulling insert 6. When the mold is opened, the inner slider 4 moves to the right under the driving action of the delayed bending pin 2, and the inner slider 4 drives the pull bar 5 with the oblique guide groove 7 installed at its front end to move to the right. Under the limiting action of the strip hole 9 and the limit pin 10, one end of the two core-pulling inserts 6 is close to each other, so that the two opposite undercuts 17 of the injection product 16 gradually escape from the undercut molding groove 8.

[0036] The present invention is driven by the machine opening and closing mold movement without the aid of other external forces. Before mold opening, the core pulling mechanism is in the initial state. When the mold is opened, the inner slider 4 starts to move under the drive of the delayed bending pin 2, while the main slider seat 1 will not move during the delay period of the delayed bending pin 2. The inner slider 4 drives the pull rod 5 installed at its front end to move, and the pull rod 5 drives the two core pulling inserts 6 to translate, so that the ends of the two core pulling inserts 6 with the undercut molding groove 8 are close to each other, so that the two undercuts 17 of the injection product 16 relative to each other are disengaged from the undercut molding groove 8, and the pull rod 5 stops moving after reaching the predetermined position; then the main slider seat 1 ends due to the delay period of the delayed bending pin 2, and under the drive of the delayed bending pin 2, the delayed bending pin 2 drives the main slider seat 1, the molding insert 3 and the two core pulling inserts 6 to move as a whole and continue to move, completing the conventional slider side core pulling action, and stops moving after reaching the predetermined position of the main slider seat 1 on the mold frame, the mold opening is completed, the mold ejects the product, and then the mold is closed in the opposite movement order to return to the initial state. The main slider seat 1 and the inner slider 4 are driven by the delayed bending pin 2 in a single manner, adopt a purely mechanical structure, have a stable driving force, and have a simple structure and are suitable for mass production.

[0037] The present embodiment also provides a core pulling method for the secondary core pulling mechanism of the slider of the above-mentioned injection mold, comprising the following steps: the mold is opened, the delayed bending pin 2 moves vertically upward, the delayed bending pin 2 enters the first core pulling stroke, the delayed bending pin 2 drives the inner slider 4 to move along the first slide, the inner slider 4 moves with the pull rod 5, the pull rod 5 drives the two core pulling inserts 6 to translate in the second slide, so that the ends of the two core pulling inserts 6 with the undercut molding grooves 8 are close to each other, so that the two undercuts 17 relative to the injection molded product 16 are out of the undercut molding grooves 8, completing the first core pulling; the delayed bending pin 2 continues to move upward, the delayed bending pin 2 enters the second core pulling stroke, the delayed bending pin 2 drives the main slider seat 1, the molding insert 3 and the two core pulling inserts 6 to move as a whole, so that the molding surface of the molding insert 3 is away from the injection molded product 16, completing the second core pulling.

[0038] Compared with the prior art, the present invention has the following advantages:

[0039] 1. It can realize the function of simultaneous release of undercuts 17 in multiple directions;

[0040] 2. The driving force is simple and single, and the core pulling mechanism runs smoothly;

[0041] 3. The overall structure is simple, and the undercut 17 of the injection molded product 16 has a good release effect;

[0042] 4. It can save the investment and use cost of one or more sliders and reduce the space occupied by the mold;

[0043] 5. It can improve production stability and reduce loss and maintenance costs.

[0044] In the description of the present invention, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, and may be fixedly connected, detachably connected, or integrated; may be mechanically connected or electrically connected; may be directly connected or indirectly connected through an intermediate medium, may be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood. In addition, the specific features, structures, etc. described in the embodiments are included in at least one embodiment. Under the condition that there is no contradiction, those skilled in the art may combine the features of different embodiments. The protection scope of the present invention is not limited to the above-mentioned specific embodiments. According to the basic technical concept of the present invention, the embodiments that can be associated with by ordinary technicians in this field without creative work all belong to the protection scope of the present invention.

Claims

1. A core pulling method for a secondary core pulling mechanism of a slider of an injection mold, characterized in that: The slider secondary core-pulling mechanism of the injection mold comprises a main slider seat (1), a delayed bending pin (2), a molding insert (3), an inner slider (4), a pull rod (5) and two core-pulling inserts (6); the main slider seat (1) is slidably arranged in the mold cavity of the injection mold, and a first slideway adapted to the inner slider (4) is provided inside the main slider seat (1); one end of the molding insert (3) is connected to the main slider seat (1), and the other end of the molding insert (3) is provided with a molding surface for forming the side of the injection molded product (16); a second slideway is provided inside the molding insert (3), one end of the second slideway is connected to the first slideway, and the other end of the second slideway is provided with an open end extending to the molding surface; The pull rod (5) is slidably arranged in the second slideway, one end of the pull rod (5) is connected to the inner slide block (4), and the other end of the pull rod (5) is provided with two oblique guide grooves (7); the core-pulling insert (6) is movably arranged in the second slideway, the core-pulling insert (6) is slidably matched with the oblique guide grooves (7) on the surface of the pull rod (5), and the end of the core-pulling insert (6) is provided with an undercut molding groove (8) for molding an undercut (17) of an injection molded product (16); The time-delay bending pin (2) is inserted on the main slider seat (1), and the time-delay bending pin (2) drives the inner slider (4) to move with the pull rod (5) in the first core pulling stroke, and the pull rod (5) drives the two core pulling inserts (6) to translate in the second slideway, so that the ends of the two core pulling inserts (6) with the undercut molding groove (8) are close to each other, so that the two undercuts (17) opposite to the injection molded product (16) are out of the undercut molding groove (8); the time-delay bending pin (2) drives the main slider seat (1), the molding insert (3) and the two core pulling inserts (6) to move as a whole in the second core pulling stroke, so that the molding surface of the molding insert (3) is away from the injection molded product (16); The end faces of the pull rod (5) and the two core-pulling inserts (6) are flush with the molding surface, so that the end faces of the pull rod (5) and the two core-pulling inserts (6) block the open end; the end of the pull rod (5) is provided with two inclined surfaces, and the inclined guide groove (7) is arranged along the inclined surfaces; the inner slide block (4) is provided with a avoidance hole (15) adapted to the delayed bending pin (2); The inclined guide groove (7) is T-shaped; the pull bar (5) is L-shaped; a strip hole (9) is provided at one end of the core-pulling insert (6) away from the undercut molding groove (8); a limit pin (10) is provided in the second slideway, and the limit pin (10) is inserted in the strip hole (9); The core pulling method comprises the following steps: The mold is opened, the delayed bending pin (2) moves vertically upward, the delayed bending pin (2) enters the first core pulling stroke, the delayed bending pin (2) drives the inner slider (4) to move along the first slideway, the inner slider (4) moves with the pull rod (5), and the pull rod (5) drives the two core pulling inserts (6) to move in the second slideway, so that the ends of the two core pulling inserts (6) with the undercut molding grooves (8) are close to each other, so that the two undercuts (17) opposite to the injection molded product (16) are out of the undercut molding grooves (8), completing the first core pulling; The delayed bending pin (2) continues to move upward, and the delayed bending pin (2) enters the second core pulling stroke. The delayed bending pin (2) drives the main slider seat (1), the molding insert (3) and the two core pulling inserts (6) to move as a whole, so that the molding surface of the molding insert (3) is away from the injection molded product (16), completing the second core pulling.

2. The core pulling method of the slider secondary core pulling mechanism of the injection mold according to claim 1, characterized in that: The molding insert (3) comprises a molding insert block (11) and a mounting cover plate (12), and the molding insert block (11) and the mounting cover plate (12) are detachably connected.

3. The core pulling method of the slider secondary core pulling mechanism of the injection mold according to claim 1, characterized in that: One end of the inner sliding block (4) is provided with a limit slot (13), and one end of the pull bar (5) is provided with a clamping head (14) adapted to the limit slot (13).

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