Secondary ejection mechanism for injection mold

Abstract

The utility model discloses a secondary ejection mechanism of injection mold belongs to injection mold field. A secondary ejection mechanism of injection mold, including recessed die and male die who cooperates with each other, the first ejector rod is slidably connected in the ejection channel, the second ejector rod who slides along the first ejector rod axis direction, the middle part of second ejector rod is provided with impact piece, and the negative pressure chamber is formed to impact piece close to the first ejector rod ejection end, and the reset spring is set up on second ejector rod, and the both ends of reset spring are fixedly connected with impact piece and negative pressure chamber inner wall respectively, the utility model discloses can make the first ejector rod and second ejector rod cooperate with the use of air injection hole, and the gas is spouted to the recessed die cavity in the continuous ejection, and the pressure between product and recessed die cavity is increased, and then the partial vacuum adsorption effect in recessed die cavity is eliminated, and the reverse buckling area is separated synchronously, and the adsorption between injection liquid and recessed die inner wall is reduced, and then the demolding efficiency is improved, and the difficulty of forming piece taking out is prevented.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and in particular to a secondary ejection mechanism for injection molds. Background Technology

[0002] As an important branch of mold manufacturing, injection molds are mainly used to shape and process molten plastic injected by injection molding machines, giving products a specific shape and structure. This processing method has significant advantages such as high production efficiency and flexible shape customization. It is particularly suitable for mass production of complex plastic products and has become an indispensable key process in modern industrial production. In the injection molding process, the ejection mechanism plays a key role as an important device to assist in demolding.

[0003] In actual production, when high-temperature molten plastic is injected into the mold cavity and cooled and solidified, due to the strong adsorption between the plastic and the inner wall of the mold, coupled with the complex structure of some products (such as having undercuts, deep cavities, etc.), the traditional single ejection action often cannot achieve complete demolding, resulting in difficulty in removing the molded parts. Utility Model Content

[0004] The purpose of this invention is to solve the problem that in the prior art, a single ejection action often makes it difficult to achieve complete demolding, resulting in difficulty in removing the molded part. Therefore, a secondary ejection mechanism for injection molds is proposed.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A secondary ejection mechanism for an injection mold includes a cooperating concave mold and a convex mold. An ejection channel is provided within the concave mold, and a first ejector rod is slidably connected within the ejection channel. The mechanism further includes a second ejector rod that slides along the axis of the first ejector rod. An impact member is disposed at the middle of the second ejector rod, and a negative pressure chamber is formed near the ejection end of the first ejector rod from the impact member. A return spring is sleeved on the second ejector rod, with its two ends fixedly connected to the impact member and the inner wall of the negative pressure chamber, respectively. An elastic locking member is disposed within the ejection channel. A trigger plate is fixedly connected to one end of the second ejector rod, and the trigger plate cooperates with the locking member. When the potential energy of the return spring is greater than the potential energy of the elastic locking member, the trigger plate disengages from the locking member.

[0007] In order to transport gas in the negative pressure chamber, preferably, the impact member includes a piston fixedly connected to the second push rod, the piston being in contact with the inner wall of the ejection channel, and the second push rod extending through the negative pressure chamber to the outside and being provided with an air jet disc.

[0008] To facilitate the delivery of gas within the negative pressure chamber, the end of the first push rod is provided with a groove, the side wall of the jet disk is provided with a jet hole, and a diversion channel communicating with the jet hole is provided inside the jet disk. The diversion channel is connected to the negative pressure chamber through a delivery channel.

[0009] To facilitate the concealment of the air jet, preferably, the air jet disc has the same cross-sectional diameter as the groove.

[0010] To facilitate locking the second push rod, preferably, the locking element includes a locking ball, and a placement groove is provided on the inner wall of the push channel. The locking ball is connected to the inner wall of the placement groove by a connecting spring.

[0011] To facilitate the movement of the first ejector rod, preferably, a telescopic component is fixedly connected to the concave mold, and the output end of the telescopic component extends into the ejection channel and is provided with a connecting plate. The first ejector rod is fixedly connected to the connecting plate through a connecting rod.

[0012] Compared with the prior art, this utility model provides a secondary ejection mechanism for injection molds, which has the following beneficial effects:

[0013] 1. The secondary ejection mechanism of this injection mold can perform the initial ejection of the finished product in the cavity of the mold cavity through the first ejector rod, ejecting a part of the plastic part, such as the main structure being separated from the cavity, to achieve the first ejection;

[0014] 2. The secondary ejection mechanism of this injection mold can perform secondary ejection based on the first ejector through the second ejector, supplementing the separation force of the first ejector, such as ejecting the undercut or small features on the side wall, to achieve the second ejection;

[0015] 3. The secondary ejection mechanism of the injection mold sprays gas into the cavity of the mold cavity through the air jet hole, which can increase the pressure between the product and the cavity of the mold cavity, thereby eliminating the local vacuum adsorption effect in the cavity of the mold cavity, simultaneously separating the undercut area, and reducing the adsorption force between the injection liquid and the inner wall of the mold cavity.

[0016] The parts not mentioned in this device are the same as or can be implemented using existing technology. This utility model can use the first ejector rod and the second ejector rod in conjunction with the air jet hole to spray gas into the cavity of the mold cavity while continuously ejecting, thereby increasing the pressure between the product and the cavity of the mold cavity, thus eliminating the local vacuum adsorption effect in the cavity of the mold cavity, simultaneously separating the undercut area, reducing the adsorption force between the injection molding liquid and the inner wall of the mold cavity, thereby improving the demolding efficiency and preventing the molded parts from being difficult to remove. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0019] Figure 1 This utility model provides a schematic diagram of the planar structure of a secondary ejection mechanism for an injection mold. Figure 1 ;

[0020] Figure 2 This utility model provides a schematic diagram of the planar structure of a secondary ejection mechanism for an injection mold. Figure 2 ;

[0021] Figure 3 This is a partial structural diagram of a secondary ejection mechanism for an injection mold proposed in this utility model. Figure 1 ;

[0022] Figure 4 This is a partial structural diagram of a secondary ejection mechanism for an injection mold proposed in this utility model. Figure 2 ;

[0023] Figure 5 This is a cross-sectional structural diagram of a secondary ejection mechanism for an injection mold proposed in this utility model.

[0024] In the diagram: 1. Concave mold; 2. Ejection channel; 3. First ejector rod; 4. Groove; 5. Piston; 6. Punch mold; 7. Air jet disc; 8. Return spring; 9. Second ejector rod; 10. Trigger plate; 11. Telescopic component; 12. Connecting plate; 13. Connecting rod; 14. Placement slot; 15. Connecting spring; 16. Locking ball; 17. Conveying channel; 18. Air jet hole. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0026] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] Injection molds are key process equipment for molding plastic products. Their working principle involves injecting molten plastic into a mold cavity under high pressure, which then cools and solidifies to obtain the desired shape. They mainly consist of a fixed mold (cavity mold 1) and a moving mold (punch mold 6), along with auxiliary devices such as a gating system, ejection mechanism, and temperature control system. The core characteristics of injection molds include: 1. Precision: mold cavity accuracy can reach 0.01mm level; 2. High efficiency: single molding cycle can be as short as a few seconds; 3. Complexity: capable of molding products with complex structures such as threads and undercuts. Based on structure, they can be divided into two-plate molds, three-plate molds, hot runner molds, etc., and are widely used in automotive parts, electronic products, daily necessities, and other fields. Furthermore, injection molds integrate CAD / CAM design, high-precision machining (such as wire EDM), mold flow analysis, and other technologies, offering advantages such as long lifespan (up to millions of injection cycles) and high degree of automation.

[0028] Example:

[0029] Reference Figures 1-5A secondary ejection mechanism for an injection mold, in conjunction with an injection system, ejection mechanism, temperature control system, and other auxiliary devices, performs injection molding of products. Its working principle involves injecting molten plastic into the mold cavity under high pressure, followed by cooling and solidification to obtain the desired product shape. An ejection channel 2 is provided within the cavity mold 1, and a first ejector rod 3 is slidably connected within the ejection channel 2. The first ejector rod 3 allows for the initial ejection of the finished product from the cavity mold 1, partially ejecting the plastic part (e.g., the main structure detaching from the cavity). The second ejection mechanism, sliding along the axis of the first ejector rod 3... The push rod 9 allows for a secondary ejection based on the first push rod 3, increasing the separation force of the first push rod 3 (e.g., ejecting sidewall buckles or small features). An impact element is located in the middle of the second push rod 9, forming a negative pressure chamber near the ejection end of the first push rod 3. A return spring 8 is fitted onto the second push rod 9, with its two ends fixedly connected to the impact element and the inner wall of the negative pressure chamber, respectively. When the first push rod 3 is used, the second push rod 9 is positioned within the groove 4, sealing the air jet hole 18. (Air jet disc 7) (With the same cross-sectional diameter as groove 4), and the negative pressure chamber under negative pressure, the return spring 8 is in a stretched state. At this time, the elastic locking element set in the ejection channel 2 will lock the trigger plate 10 on one end of the second push rod 9. During this process, the potential energy of the return spring 8 is less than the potential energy of the elastic locking element, which allows the trigger plate 10 to cooperate with the locking element and lock the trigger plate 10. When the potential energy of the return spring 8 is greater than the potential energy of the elastic locking element, the trigger plate 10 disengages from the locking element, thereby causing the second push rod 9 to drive the jet disc. As the first ejector rod 3 extends outward, the gas in the negative pressure chamber is transported to the jet plate 7 through the conveying channel 17, and then ejected from the jet holes 18 on the side wall of the jet plate 7 into the cavity of the mold cavity 1. This increases the pressure between the product and the cavity of the mold cavity 1, thereby eliminating the local vacuum adsorption effect in the cavity of the mold cavity 1, simultaneously separating the undercut area, reducing the adsorption force between the injection molding liquid and the inner wall of the mold cavity 1, and thus achieving the effects of first ejection, second ejection and jet pressurization, improving demolding efficiency and preventing difficulties in removing the molded parts.

[0030] In the above scheme, the first ejector rod 3 can perform the initial ejection of the finished product in the cavity of the mold cavity 1, ejecting a part of the plastic part (such as the main structure detaching from the cavity), achieving the effect of the first ejection. The second ejector rod 9 can perform a second ejection based on the first ejector rod 3, supplementing the separation force of the first ejector rod 3, such as ejecting the undercut or small features on the side wall, achieving the effect of the second ejection. During this process, the air jet holes 18 on the side wall of the air jet disk 7 will spray gas towards the cavity of the mold cavity 1, increasing the pressure between the product and the cavity of the mold cavity 1, thereby eliminating the local vacuum adsorption effect in the cavity of the mold cavity 1, simultaneously separating the undercut area, reducing the adsorption force between the injection molding liquid and the inner wall of the mold cavity 1, thereby improving the demolding efficiency and preventing difficulties in removing the molded part.

[0031] A telescopic component 11 is fixedly connected to the concave mold 1. The output end of the telescopic component 11 extends into the ejection channel 2 and is provided with a connecting plate 12. The first ejector rod 3 is fixedly connected to the connecting plate 12 through the connecting rod 13. The telescopic component 11 can drive the connecting plate 12 to move, and then the connecting rod 13 can drive the first ejector rod 3 to move synchronously. The telescopic component 11 can be an electric telescopic rod or a cylinder, used to drive the first ejector rod 3 to move.

[0032] The aforementioned impact component includes a piston 5 fixedly connected to the second push rod 9. The piston 5 fits against the inner wall of the ejection channel 2. The second push rod 9 extends through the negative pressure chamber to the outside and is equipped with an air jet disc 7. The piston 5 can generate a negative pressure effect in the negative pressure chamber.

[0033] A groove 4 is provided at the end of the first push rod 3, and an air jet hole 18 is provided on the side wall of the air jet disk 7. A diversion channel connected to the air jet hole 18 is provided inside the air jet disk 7. The diversion channel is connected to the negative pressure chamber through the conveying channel 17. The conveying channel 17 is provided on the second push rod 9.

[0034] It should be explained that the locking component includes a locking ball 16, and a placement groove 14 is provided on the inner wall of the ejection channel 2. The locking ball 16 is connected to the inner wall of the placement groove 14 through a connecting spring 15. When the potential energy of the reset spring 8 is greater than the potential energy of the connecting spring 15, the trigger plate 10 disengages from the locking component.

[0035] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A secondary ejection mechanism for an injection mold, comprising a cooperating concave mold (1) and a convex mold (6), wherein an ejection channel (2) is provided in the concave mold (1), and a first ejector rod (3) is slidably connected in the ejection channel (2), characterized in that, Also includes: The second push rod (9) slides along the axis of the first push rod (3). Among them, the second push rod (9) is provided with an impact member in the middle, and a negative pressure chamber is formed near the push end of the first push rod (3). A reset spring (8) is sleeved on the second push rod (9), and the two ends of the reset spring (8) are fixedly connected to the impact member and the inner wall of the negative pressure chamber, respectively. An elastic locking element is installed in the ejection channel (2). One end of the second push rod (9) is fixedly connected to a trigger plate (10). The trigger plate (10) cooperates with the locking member. When the potential energy of the reset spring (8) is greater than the potential energy of the elastic locking member, the trigger plate (10) disengages from the locking member.

2. The secondary ejection mechanism of an injection mold according to claim 1, characterized in that, The impact component includes a piston (5) fixedly connected to the second push rod (9), the piston (5) being in contact with the inner wall of the ejection channel (2), and the second push rod (9) extending through the negative pressure chamber to the outside and being provided with an air jet disc (7).

3. The secondary ejection mechanism of an injection mold according to claim 2, characterized in that, The first push rod (3) has a groove (4) at its end, and the side wall of the jet disk (7) has a jet hole (18). The jet disk (7) has a diversion channel that communicates with the jet hole (18). The diversion channel is connected to the negative pressure chamber through the conveying channel (17).

4. The secondary ejection mechanism of an injection mold according to claim 3, characterized in that, The cross-sectional diameter of the jet disk (7) is the same as that of the groove (4).

5. The secondary ejection mechanism of an injection mold according to claim 1, characterized in that, The locking component includes a locking ball (16), and a placement groove (14) is provided on the inner wall of the ejection channel (2). The locking ball (16) is connected to the inner wall of the placement groove (14) by a connecting spring (15).

6. The secondary ejection mechanism of an injection mold according to claim 1, characterized in that, A telescopic component (11) is fixedly connected to the concave mold (1). The output end of the telescopic component (11) extends into the ejection channel (2) and is provided with a connecting plate (12). The first ejector rod (3) is fixedly connected to the connecting plate (12) through a connecting rod (13).

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