Injection mold

Abstract

The utility model relates to the technical field of plastic injection molding, in particular to an injection mold which comprises a top mold, a bottom mold and a first ejector pin. The rear mold insert is of a hollow columnar structure and is vertically and fixedly arranged in the middle of the rear mold core, and a limiting part extending inwards is arranged in the middle of the inner side wall of the rear mold insert; the movable insert is movably mounted in the middle of the rear mold insert in a lifting manner, the top of the outer side wall of the movable insert and the top of the inner side wall of the rear mold insert define a groove for injection molding of the annular convex column, the bottom of the outer side wall of the movable insert is provided with a first flange extending outwards, and the limiting part is used for limiting the height of the first flange; and a horn top. According to the injection mold, the problem that in the demolding process, the annular convex column is tightly attached to the two inserts located on the periphery and in the middle of the annular convex column, so that it is difficult for an ejector pin to eject the annular convex column out of the position between the two inserts to complete demolding is solved, and the pressure needed for ejecting a plastic workpiece out of the inserts can be reduced; therefore, the plastic workpiece can be demoulded more simply and conveniently.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic injection molding, in particular to an injection mold. BACKGROUND

[0002] In the process of demolding a plastic workpiece with a ring-shaped convex column on one side, the front mold core (i.e. the part of the mold that fits the side of the plastic workpiece without a ring-shaped convex column) is generally removed first, and then the plastic workpiece is ejected from the rear mold core (i.e. the part of the mold that fits the side of the plastic workpiece with a ring-shaped convex column) by a ejector pin.

[0003] However, the mold generally includes two inserts respectively arranged at the outer periphery and the middle of the ring-shaped convex column. If the plastic workpiece is to be ejected from the rear mold core by the ejector pin, the ring-shaped convex column needs to be ejected from between the two inserts. The two inserts are tightly fitted with the outer side wall and the inner side wall of the ring-shaped convex column, respectively, and there is stress inside the plastic workpiece when it is not demolded. The outer side wall and the inner side wall of the ring-shaped convex column have the tendency to expand outward and inward, respectively, making the ring-shaped convex column and the two inserts fit more tightly, which makes it difficult for the ejector pin to eject the ring-shaped convex column from between the two inserts to complete the demolding.

[0004] Therefore, the prior art needs to be improved and developed. CONTENT OF THE UTILITY MODEL

[0005] The purpose of the present application is to provide an injection mold, which aims to solve the problem that the ring-shaped convex column and the two inserts located at its outer periphery and middle fit tightly during the demolding process, making it difficult for the ejector pin to eject the ring-shaped convex column from between the two inserts to complete the demolding.

[0006] The present application provides an injection mold for making a plastic workpiece with a ring-shaped convex column on the bottom surface, comprising a top mold, a bottom mold and a first ejector pin, wherein the bottom mold comprises:

[0007] a rear mold core;

[0008] a rear mold insert, which is a hollow columnar structure, is vertically fixedly arranged in the rear mold core, and has a limiting portion extending inward in the middle of the inner side wall;

[0009] a movable insert, which is a hollow columnar structure, is movably installed in the middle of the rear mold insert, the top of the outer side wall and the top of the inner side wall of the rear mold insert form a groove for injection molding the ring-shaped convex column, and the bottom of the outer side wall has a first flange extending outward, and the limiting portion is used to limit the height of the first flange;

[0010] a horn top, which is a columnar structure with the top of the side wall expanding outward from bottom to top, is movably installed in the middle of the movable insert, the side wall is fitted with the inner side wall of the movable insert, and is used to be lifted to lift the plastic workpiece;

[0011] The first ejector pin is arranged below the horn top and the top of the first ejector pin is fixedly connected with the bottom of the horn top. The injection mold provided by the application divides the process of ejecting the annular protrusion from the two inserts into two stages, and in each stage, the annular protrusion can be ejected by overcoming only the friction between the annular protrusion and one insert, so that the injection mold of the application can reduce the pressure required for ejecting the plastic workpiece from the insert, thereby facilitating the demolding of the plastic workpiece.

[0012] Optionally, the distance between the bottom surface of the limiting part and the top surface of the first flange is greater than or equal to the distance between the top surface of the annular protrusion and the bottom surface.

[0013] In this embodiment, the injection mold of the application can ensure that the annular protrusion is not in contact with the rear mold insert when the movable insert is limited, thereby facilitating the subsequent ejection of the overall component formed by the horn top and the plastic workpiece from the movable insert.

[0014] Optionally, the inner side wall of the annular protrusion has an inwardly recessed buckling groove.

[0015] The outer side wall of the movable insert has a second flange at the top for injection molding the buckling groove.

[0016] In this embodiment, the injection mold of the application is provided with a second flange, which can enable the movable insert and the plastic workpiece to be buckled together, and can ensure that the horn top, the movable insert and the plastic workpiece form an overall component that is subjected to force together during the process of the first ejector pin ejecting the plastic workpiece from the rear mold insert, thereby facilitating the first ejector pin to eject the overall component formed by the horn top, the movable insert and the plastic workpiece from the rear mold insert, and without excessively increasing the difficulty of ejecting the overall component formed by the horn top and the plastic workpiece from the movable insert.

[0017] Optionally, the injection mold further comprises:

[0018] The second ejector pin passes through the rear mold insert and is used for lifting to lift the plastic workpiece.

[0019] Optionally, the number of the second ejector pins is multiple, and the multiple second ejector pins are arranged in a circular array outside the first ejector pin with the first ejector pin as the center.

[0020] Optionally, the injection mold further comprises:

[0021] The first lifting plate is fixedly installed on the bottom of the first ejector pin.

[0022] Optionally, the injection mold further comprises:

[0023] The forming seat is fixedly arranged on the rear mold insert.

[0024] The elastic member abuts against the bottom of the forming seat at one end.

[0025] The second lifting plate is fixedly mounted on the first lifting plate, with the other end of the elastic element abutting against the top of the second lifting plate.

[0026] Optionally, the injection mold may also include:

[0027] The base is located below the first lifting plate and is fixedly connected to the forming seat, and has a vertically arranged through hole in its middle.

[0028] Optionally, the top bottom of the speaker has a first mounting groove;

[0029] The top of the first ejector pin has a second mounting groove;

[0030] Injection molds also include:

[0031] The mounting component has one end inserted into the first mounting slot and the other end inserted into the second mounting slot.

[0032] Optionally, the movable insert is made of beryllium copper.

[0033] As can be seen from the above, the process of ejecting the annular protrusion from between the two inserts by the injection mold of this application is divided into two stages. In each stage, it is only necessary to overcome the friction between the annular protrusion and one insert to eject the annular protrusion. Therefore, the injection mold of this application can reduce the pressure required to eject the plastic workpiece from the insert, thereby making it easier to demold the plastic workpiece.

[0034] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of an injection mold provided in an embodiment of this application.

[0036] Figure 2 A cross-sectional view of an injection mold with respect to the first ejector pin, provided for an embodiment of this application.

[0037] Figure 3 For this application Figure 2 Enlarged view of point A in the middle.

[0038] Figure 4 For this application Figure 3 Enlarged view of point B in the middle.

[0039] Figure 5 A cross-sectional view of an injection mold with respect to the second ejector pin, provided for an embodiment of this application.

[0040] Figure 6A structure diagram of a plastic workpiece provided by an embodiment of the present application.

[0041] Figure 7 A structure diagram of a forming seat provided by an embodiment of the present application.

[0042] Figure 8 A structure diagram of a base provided by an embodiment of the present application.

[0043] Label explanation: 100, top die; 200, bottom die; 1, back die core; 2, back die insert; 21, limiting part; 3, movable insert; 31, first flange; 32, second flange; 4, horn top; 5, first ejector pin; 6, second ejector pin; 7, first lifting plate; 8, forming seat; 9, elastic member; 10, second lifting plate; 11, base; 111, through hole; 12, mounting member; 20, plastic workpiece; 201, annular convex column; 202, buckling groove. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0045] It should be noted that: similar labels and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0046] As shown in Figure 2 , Figure 3 , Figure 6 and Figure 7 , the present application provides an injection mold for manufacturing a plastic workpiece 20 with an annular convex column 201 on the bottom surface, including a top die 100, a bottom die 200 and a first ejector pin 5, the bottom die 200 includes:

[0047] a back die core 1;

[0048] a back die insert 2, which is a hollow column structure, vertically fixedly arranged in the back die core 1, and has a limiting part 21 extending inward in the middle of the inner side wall;

[0049] The movable insert 3 is a hollow cylindrical structure, which is movably installed in the middle of the rear mold insert 2. The top of the outer sidewall of the movable insert 3 and the top of the inner sidewall of the rear mold insert 2 form a groove for injection molding the annular convex column 201. The bottom of the outer sidewall of the movable insert 3 has a first flange 31 extending outward, and the limiting part 21 is used to limit the height of the first flange 31.

[0050] The horn top 4 is a cylindrical structure with the sidewall expanding outward from bottom to top, which is movably installed in the middle of the movable insert 3. The sidewall of the horn top 4 is in contact with the inner sidewall of the movable insert 3, and is used to lift the plastic workpiece 20.

[0051] The first ejector pin 5 is arranged below the horn top 4, and the top of the first ejector pin 5 is fixedly connected with the bottom of the horn top 4.

[0052] Specifically, in the present application, the plastic workpiece 20 has an annular convex column 201 on the bottom surface, which means that the plastic workpiece 20 has an annular convex column 201 on the bottom surface when it is located in the injection mold of the present application. In fact, the present application is applicable to both the plastic workpiece 20 with a plastic material and an annular convex column 201 on the bottom surface, and the plastic workpiece 20 with a plastic material, an annular convex column 201 on the top surface, and inverted in the injection mold.

[0053] More specifically, when the plastic workpiece 20 molded in the injection mold of the present application is demolded, the first ejector pin 5 is lifted to exert a vertical upward pressure through the horn top 4. Since the sidewall of the horn top 4 is in contact with the inner sidewall of the movable insert 3, the top of the outer sidewall of the movable insert 3 and the top of the inner sidewall of the rear mold insert 2 form a groove for injection molding the annular convex column 201, and the rear mold insert 2 is fixed, at this time, the pressure exerted by the first ejector pin 5 on the horn top 4 acts on the whole component formed by the horn top 4, the movable insert 3 and the plastic workpiece 20, thereby ejecting the whole component formed by the horn top 4, the movable insert 3 and the plastic workpiece 20 from the rear mold insert 2. After that, when the top surface of the first flange 31 contacts the bottom surface of the limiting part 21, the first flange 31 reaches the maximum height, and the movable insert 3 cannot continue to rise. At this time, the pressure exerted by the first ejector pin 5 on the horn top 4 acts on the whole component formed by the horn top 4 and the plastic workpiece 20, thereby ejecting the whole component formed by the horn top 4 and the plastic workpiece 20 from the movable insert 3. At this time, neither the rear mold insert 2 nor the movable insert 3 is in contact with the plastic workpiece 20, and the plastic workpiece 20 can be removed from the horn top 4 to complete the demolding.

[0054] More specifically, for traditional demolding methods, ejecting the annular protrusion 201 from between two inserts located on its outer periphery and center requires overcoming the outward expansion tendency of the outer wall of the annular protrusion 201 and the inward expansion tendency of the inner wall. This necessitates overcoming the frictional force between the outer wall of the annular protrusion 201 and the insert located on its outer periphery, as well as the frictional force between the inner wall of the annular protrusion 201 and the insert located in the center of the annular protrusion 201. In contrast, this application only requires overcoming the frictional force between the annular protrusion 201 and the insert located in the center of the annular protrusion 201. The friction between the outer wall of the annular protrusion 201 and the rear mold insert 2 is sufficient to eject the integral component formed by the horn top 4, the movable insert 3, and the plastic workpiece 20 from the rear mold insert 2. Afterward, the outer wall of the annular protrusion 201 is no longer constrained by the rear mold insert 2 and can expand outward. Therefore, this application only needs to overcome the friction between the outer wall of the annular protrusion 201 and the movable insert 3 to eject the integral component formed by the horn top 4 and the plastic workpiece 20 from the movable insert 3, thereby completing the demolding. Therefore, the injection mold of this application can reduce the pressure required to eject the plastic workpiece 20 from the insert, thus making demolding of the plastic workpiece 20 easier.

[0055] The injection mold of this application divides the process of ejecting the annular protrusion 201 from between two inserts into two stages. In each stage, the annular protrusion 201 can be ejected by overcoming the friction between the annular protrusion 201 and one insert. Therefore, the injection mold of this application can reduce the pressure required to eject the plastic workpiece 20 from the insert, thereby making it easier to demold the plastic workpiece 20.

[0056] In some preferred embodiments, the distance between the bottom surface of the limiting portion 21 and the top surface of the first flange 31 is greater than or equal to the distance between the top surface and the bottom surface of the annular protrusion 201.

[0057] Specifically, since the distance between the bottom surface of the limiting part 21 and the top surface of the first flange 31 is greater than or equal to the distance between the top surface and the bottom surface of the annular protrusion 201, the top surface of the first flange 31 will contact the bottom surface of the limiting part 21 only after the first ejector pin 5 completely ejects the annular protrusion 201 from the rear mold insert 2. Therefore, in this embodiment, the injection mold of this application can ensure that the annular protrusion 201 does not contact the rear mold insert 2 at all when the movable insert 3 is limited, which facilitates the subsequent ejection of the integral part formed by the horn top 4 and the plastic workpiece 20 from the movable insert 3.

[0058] like Figure 4 As shown, in some preferred embodiments, the inner wall of the annular protrusion 201 has an inwardly recessed fastening groove 202.

[0059] The top of the outer wall of the movable insert 3 has a second flange 32 for injection molding the snap-fit ​​groove 202.

[0060] In this embodiment, the injection mold of the present application is provided with the second flange 32, which can make the movable insert 3 and the plastic workpiece 20 fasten together, and can ensure that the horn top 4, the movable insert 3 and the plastic workpiece 20 form an integral component to bear force together during the process of ejecting the plastic workpiece 20 from the back mold insert 2 after the first ejector pin 5 ejects the plastic workpiece 20, so as to facilitate the first ejector pin 5 to eject the integral component formed by the horn top 4, the movable insert 3 and the plastic workpiece 20 from the back mold insert 2, and will not excessively increase the difficulty of ejecting the integral component formed by the horn top 4 and the plastic workpiece 20 from the movable insert 3.

[0061] As shown in Figure 5 , in some preferred embodiments, the injection mold further comprises:

[0062] The second ejector pin 6 passes through the back mold insert 2 and is used for lifting to lift the plastic workpiece 20.

[0063] In this embodiment, the present application is provided with the second ejector pin 6, which can make the first ejector pin 5 and the second ejector pin 6 jointly lift when demolding the plastic workpiece 20 formed in the injection mold, so as to make the second ejector pin 6 exert vertical upward pressure on the plastic workpiece 20, thereby cooperating with the first ejector pin 5 to eject the integral component formed by the horn top 4, the movable insert 3 and the plastic workpiece 20 from the back mold insert 2.

[0064] In some preferred embodiments, the number of the second ejector pin 6 is multiple, and the multiple second ejector pins 6 are arranged in a circular array outside the first ejector pin 5 with the first ejector pin 5 as the center.

[0065] In this embodiment, the present application is provided with multiple second ejector pins 6, which can exert pressure on multiple areas around the area where the bottom surface of the plastic workpiece 20 is attached to the top surface of the horn top 4, so as to avoid the demolding failure or damage of the plastic workpiece 20 caused by uneven force on the bottom surface of the plastic workpiece 20.

[0066] As shown in Figure 1 and Figure 2 , in some preferred embodiments, the injection mold further comprises:

[0067] The first lifting plate 7 is fixedly installed on the bottom of the first ejector pin 5.

[0068] In this embodiment, the present application is provided with the first lifting plate 7, which can simply make the first ejector pin 5 lift by exerting vertical upward pressure on the first lifting plate 7.

[0069] In some preferred embodiments, the injection mold further comprises:

[0070] The back mold insert 1 is fixedly arranged on the forming seat 8.

[0071] The elastic member 9 abuts against the bottom of the forming seat 8 at one end.

[0072] The second lifting plate 10 is fixedly arranged on the first lifting plate 7, and the other end of the elastic member 9 abuts against the top of the second lifting plate 10.

[0073] In this embodiment, the injection mold of the present application can make the first lifting plate 7 lift the second lifting plate 10 when the first lifting plate 7 is lifted, so that the two ends of the elastic member 9 are tightly pressed against the bottom of the forming seat 8 and the top of the second lifting plate 10, respectively, thereby enabling the first lifting plate 7 and the second lifting plate 10 to be lowered and reset based on the elastic member 9 when no vertical upward pressure is applied to the first lifting plate 7 subsequently.

[0074] As shown in Figure 8 In some preferred embodiments, the injection mold further comprises:

[0075] The base 11 is arranged below the first lifting plate 7 and is fixedly connected with the forming seat 8, and has a vertical through hole 111 in the middle.

[0076] In this embodiment, the injection mold of the present application is provided with the base 11 having the through hole 111 in the middle, which can provide support for the forming seat 8, and only needs to make the needle-like lifting tool pass through the through hole 111 to abut against the first lifting plate 7 to apply force to the first lifting plate 7, so as to conveniently lift the first lifting plate 7, and the base 11 can also define the lowest height of the first lifting plate 7, preventing the first lifting plate 7 from excessively lowering to cause subsequent inconvenience in applying force to the first lifting plate 7 again after no vertical upward pressure is applied to the first lifting plate 7.

[0077] In some preferred embodiments, the bottom of the horn top 4 has a first mounting groove;

[0078] The top of the first ejector pin 5 has a second mounting groove;

[0079] The injection mold further comprises:

[0080] The mounting member 12 is inserted into the first mounting groove at one end and is inserted into the second mounting groove at the other end.

[0081] In this embodiment, the injection mold of the present application is provided with the mounting member 12, which facilitates the fixed connection of the horn top 4 and the first ejector pin 5.

[0082] In some preferred embodiments, the material of the movable insert 3 is beryllium copper.

[0083] Specifically, since beryllium copper has self-lubricating property and good heat dissipation performance, in this embodiment, the injection mold of the present application sets the material of the movable insert 3 as beryllium copper, which can reduce the heat generated by the friction of the components in the injection mold during demolding, thereby avoiding fatigue scratches of the components.

[0084] Preferably, the material of the back mold insert 2 and the horn top 4 is iron.

[0085] As can be seen from the above, the injection mold provided by the present application divides the process of ejecting the annular protrusion 201 from between the two inserts into two stages, and in each stage only needs to overcome the friction between the annular protrusion 201 and one insert to eject the annular protrusion 201, so that the injection mold provided by the present application can reduce the pressure required to eject the plastic workpiece 20 from the insert, thereby making the demolding of the plastic workpiece 20 more convenient.

[0086] In the embodiments provided in the present application, it should be understood that, in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations.

[0087] The above only describes the embodiments of the present application and is not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An injection mold for manufacturing a plastic workpiece (20) having a ring-shaped protrusion (201) on a bottom surface, characterized by, It comprises a top die (100), a bottom die (200) and a first ejector pin (5), wherein the bottom die (200) comprises: a back die core (1); a back die insert (2) which is a hollow cylindrical structure and is vertically fixed in the back die core (1), and has a limiting part (21) extending inward in the middle of the inner side wall; a movable insert (3) which is a hollow cylindrical structure and is vertically movable and installed in the middle of the back die insert (2), and has a first flange (31) extending outward in the bottom of the outer side wall, and the limiting part (21) is used to limit the height of the first flange (31); a horn top (4) which is a cylindrical structure with the top of the side wall expanding outward from bottom to top, and is vertically movable and installed in the middle of the movable insert (3), and the side wall is in contact with the inner side wall of the movable insert (3) to lift the plastic workpiece (20); the first ejector pin (5) is arranged below the horn top (4) and is fixedly connected with the bottom of the horn top (4).

2. The injection mold of claim 1, wherein The distance between the bottom surface of the limiting part (21) and the top surface of the first flange (31) is greater than or equal to the distance between the top surface and the bottom surface of the annular convex column (201).

3. The injection mold of claim 1, wherein The inner side wall of the annular convex column (201) has a buckling groove (202) recessed inward; the top of the outer side wall of the movable insert (3) has a second flange (32) for injection molding the buckling groove (202).

4. The injection mold of claim 1, wherein The injection mold further comprises: a second ejector pin (6) which passes through the back die insert (2) to lift the plastic workpiece (20).

5. The injection mold of claim 4, wherein The number of the second ejector pin (6) is multiple, and the multiple second ejector pins (6) are arranged in a circular array around the first ejector pin (5) with the first ejector pin (5) as the center.

6. The injection mold of claim 1, wherein, The injection mold further comprises: a first lifting plate (7) on which the bottom of the first ejector pin (5) is fixedly installed.

7. The injection mold of claim 6, wherein The injection mold further comprises: a forming seat (8) on which the back die core (1) is fixedly installed; a resilient member (9) which abuts against the bottom of the forming seat (8); a second lifting plate (10) which is fixedly installed on the first lifting plate (7) and against which the other end of the resilient member (9) abuts.

8. The injection mold of claim 7, wherein, The injection mold further comprises: a base (11) which is arranged below the first lifting plate (7) and is fixedly connected with the forming seat (8), and has a vertical through hole (111) in the middle.

9. The injection mold of claim 1, wherein, The bottom of the horn top (4) has a first mounting groove; the top of the first ejector pin (5) has a second mounting groove; The injection mold further comprises: a mounting member (12) which is inserted into the first mounting groove at one end and into the second mounting groove at the other end.

10. The injection mold of claim 1, wherein, The material of the movable insert (3) is beryllium copper.

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