Injection mold with front mold back-off core pulling and ejection mechanism

Abstract

The injection mold comprises a front mold and a front mold core, the front mold core is provided with the core-pulling and ejection mechanism, the core-pulling and ejection mechanism comprises a front mold insert, a sliding needle, an inclined sliding seat and an elastic piece, the front mold insert is movably arranged in a first containing groove of the front mold core and elastically abuts against the elastic piece, and the front mold insert is movably arranged in a second containing groove of the front mold core. The front mold insert is provided with a molding position participating in injection molding of a product, and the front mold insert is used for being pushed by the elastic piece during mold opening and ejecting the product out through the molding position; the inclined sliding seat is fixed between the front mold and the front mold core, one end of the sliding needle is connected to the inclined sliding seat in a sliding mode, the other end of the sliding needle penetrates through the front mold insert and extends outwards in an inclined mode from the forming position, and the sliding needle can be driven by the front mold insert to slide along the inclined sliding seat so as to be pulled out from the back-off position on a product. According to the utility model, the core-pulling function and the ejection function are integrated on the core-pulling and ejection mechanism, so that the structure is simplified, the occupied space is reduced, and a product is effectively prevented from being adhered to the front mold core.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to an injection mold with a front mold undercut core pulling and ejection mechanism. Background Art

[0002] The principle of injection mold is: using the thermoplasticity of plastic, the molten plastic is injected into the mold cavity through the injection molding machine, and the plastic product is obtained after cooling and solidification. Specifically, when the plastic raw material is heated and melted in the injection molding machine, the screw of the injection molding machine will push the molten plastic forward and inject it into the mold cavity through the nozzle. In the mold, the plastic will be restricted by the shape and size of the mold cavity to form the desired product shape. Then, the mold will cool and solidify the plastic product through the cooling system to keep it in the desired shape and size. Finally, the mold opens and the molded plastic product is ejected, completing the entire injection molding process.

[0003] When there is an undercut on the product that is inconsistent with the ejection direction, the basic solution for mold design is to set the slider to pull out the interference part, and then open the front and back molds or eject them. Figure 1 As shown, the prior art generally designs a slider 10 driven by a cylinder 9. Before opening the mold, the cylinder 9 drives the slider 10 to perform a core pulling action to exit the interference part, and then the mold can be opened smoothly. Although this structure can achieve core pulling, it has at least the following defects: 1. The structure of the cylinder 9 and the slider 10 is too complicated, which occupies a large space, increases the processing time and cost, has many parts, and has a high abnormal failure rate during installation and mass production. In addition, it is limited by the size, space and cost of the mold and cannot be used on some molds; 2. Driving the slider 10 by the cylinder 9 will extend the production cycle of the mold product; 3. For products with more glue positions in the front mold, it is easy to stick to the front mold. Therefore, it is necessary to improve the prior art to overcome the defects in the prior art. Summary of the invention

[0004] The problem to be solved by the utility model is to provide an injection mold with a front mold undercut core pulling and ejection mechanism to overcome the defects of the prior art such as complex structure, large space occupation, high cost, prolonged product production cycle and easy adhesion of the product to the front mold.

[0005] The utility model adopts a technical solution to solve the technical problem: an injection mold with a front mold undercut core pulling and ejection mechanism, comprising: a front mold and a front mold core fixed on the front mold, the front mold core is provided with a core pulling and ejection mechanism, the core pulling and ejection mechanism comprises a front mold insert, a sliding needle, an inclined slide seat and an elastic member, a first accommodating groove is provided on the side of the front mold core facing the mold cavity, the front mold insert is movably arranged in the first accommodating groove and is always applied with an elastic force in the direction of the mold cavity by the elastic member, and the front mold insert A molding position involved in product injection molding is provided on it, and the front mold insert is used to be pushed by the elastic member when the mold is opened and eject the product from the front mold core through the molding position; the inclined slide seat is fixedly arranged between the front mold and the front mold core, one end of the sliding needle is slidably connected to the inclined slide seat, and the other end of the sliding needle passes through the front mold insert and extends outwardly from the molding position to be used for molding the undercut position on the product, and the sliding needle can be driven by the front mold insert to slide along the inclined slide seat to be pulled out from the undercut position on the product.

[0006] As a further improvement of the present invention, the core pulling and ejection mechanism also includes a pressure guide rod, a countersunk hole is provided on one side of the front mold insert located at the forming position, one end of the pressure guide rod passes through the countersunk hole and is threadedly connected to the bottom of the first accommodating groove, and the front mold insert can slide up and down on the pressure guide rod; the other end of the pressure guide rod is provided with a pressure rod head located in the countersunk hole, and the pressure rod head is used to stop the front mold insert to limit its movement stroke.

[0007] As a further improvement of the utility model, the front mold insert is provided with a second accommodating groove coaxial with the countersunk hole, and the elastic member is a spring, which is arranged in the second accommodating groove and mounted on the pressure guide rod, and the two ends of the spring are elastically abutted against the front mold core and the front mold insert respectively.

[0008] As a further improvement of the utility model, the inclined slide seat is provided with an inclined slide groove which is distributed at a set angle with the mold opening direction, and one end of the sliding needle is slidably fitted in the inclined slide groove.

[0009] As a further improvement of the present invention, both side walls of the inclined slide groove are provided with inclined convex ribs, and one end of the sliding needle is provided with two limiting grooves, and the two limiting grooves are correspondingly slidably matched with the two inclined convex ribs.

[0010] As a further improvement of the present invention, a positioning groove is provided on one side of the front mold core facing the front mold, and the inclined slide seat is fixed in the positioning groove by screws.

[0011] As a further improvement of the utility model, an avoidance groove is provided on the front mold core, and the middle part of the sliding needle is inserted into the avoidance groove, and the avoidance groove is used to provide an avoidance space for the movement of the sliding needle.

[0012] As a further improvement of the utility model, the injection mold with a front mold undercut core pulling and ejection mechanism also includes a rear mold arranged opposite to the front mold and a rear mold core fixed on the rear mold, and the rear mold core, the front mold core and the front mold insert together form a mold cavity for the injection molded product.

[0013] The beneficial effects of the utility model are as follows: the utility model provides an injection mold with a front mold undercut core pulling and ejection mechanism, which uses an elastic member to drive the front mold insert and is linked to the sliding needle to realize ejection and core pulling actions at the same time when the mold is opened. There is no need to use an oil cylinder, which reduces costs, reduces occupied space, and is not limited by the size of the mold. The core pulling and ejection actions can be completed while the mold is opened, which can reduce the production cycle of the mold product, effectively prevent the product from sticking to the front mold core, and ensure the reliability of product ejection. The core pulling and ejection functions are combined into one on the core pulling and ejection mechanism, which greatly simplifies the structure, uses fewer parts, and reduces the abnormal failure rate during installation and mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a three-dimensional diagram of the existing core pulling mechanism;

[0015] Figure 2 It is a three-dimensional diagram of the front mold part of the injection mold with the front mold undercut core pulling and ejection mechanism of the utility model;

[0016] Figure 3 It is a three-dimensional diagram of the front mold core and the core pulling and ejection mechanism in the utility model;

[0017] Figure 4 It is a three-dimensional diagram of the core pulling and ejection mechanism in the utility model;

[0018] Figure 5 It is an exploded view of the core pulling and ejection mechanism in the utility model;

[0019] Figure 6 It is a partial bottom view of the injection mold with a front mold undercut core pulling and ejection mechanism of the utility model;

[0020] Figure 7 For this utility model Figure 6 The cross-sectional view along the AA direction;

[0021] Figure 8 For this utility model Figure 6 Cross-sectional view along direction BB.

[0022] Combined with the accompanying drawings, the following description is given:

[0023] 1. front mold; 2. front mold core; 201. first accommodating groove; 202. positioning groove;

[0024] 203, avoidance groove; 3, front mold insert; 301, molding position; 302, countersunk hole; 303, second accommodating groove; 4, sliding needle; 401, limiting groove; 5, inclined sliding seat; 501, inclined sliding groove; 502, inclined convex rib; 6, elastic member; 7, pressure guide rod; 701, pressure rod head; 8, screw; 9, oil cylinder; 10, slider. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0026] See also Figures 2 to 8 The utility model provides an injection mold with a front mold undercut core pulling and ejection mechanism, comprising: a front mold 1, a rear mold, a front mold core 2 and a rear mold core, wherein the rear mold and the rear mold core are not shown in the figure, the front mold 1 and the rear mold are arranged opposite to each other, the front mold core 2 is fixedly embedded in the groove at the bottom of the front mold 1, and the rear mold core is fixedly embedded in the groove at the top of the rear mold.

[0027] In addition, the injection mold with a front mold undercut core pulling and ejection mechanism can also include a hot runner plate, a front mold top plate, a rear mold bottom plate, a rear mold ejection mechanism, etc. These are all existing conventional technologies, so they will not be described in detail.

[0028] See also Figure 2 and Figure 3 At least one core pulling and ejection mechanism is provided on the front mold core 2, wherein the number of the core pulling and ejection mechanisms can be configured accordingly according to the number of undercut positions on the product.

[0029] See also Figures 4 to 8 The core pulling and ejection mechanism includes a front mold insert 3, a sliding needle 4, an inclined slide seat 5 and an elastic member 6. The front mold insert 3 has a molding position 301 that participates in the injection molding of the product. The rear mold core, the front mold core 2 and the front mold insert 3 together form a mold cavity for injection molding the product. A first accommodating groove 201 is provided on the side of the front mold core 2 facing the mold cavity. The front mold insert 3 can be movably arranged in the first accommodating groove 201 up and down, and the front mold insert 3 is always applied with an elastic force in the direction of the mold cavity by the elastic member 6. The front mold insert 3 is used to be pushed by the elastic member 6 when the mold is opened and eject the product from the front mold core 2 through the molding position 301 to prevent the product from sticking to the front mold core 2 and ensure the reliability of product ejection.

[0030] Furthermore, the inclined slide seat 5 is fixedly arranged between the front mold 1 and the front mold core 2, the upper end of the slide needle 4 is slidably connected to the inclined slide seat 5, and the lower end of the slide needle 4 passes through the front mold insert 3 and extends downward from the molding position 301 to be used for molding the undercut position on the product. When the mold is opened, the front mold insert 3 moves downward relative to the front mold core 2 under the elastic force of the elastic member 6, playing the role of ejecting the front mold; at the same time, the front mold insert 3 can drive the slide needle 4 to slide along the inclined slide seat 5, so that the slide needle 4 is pulled out from the undercut position on the product. It can be seen that the utility model adopts this technical solution to use the elastic part 6 to drive the front mold insert 3 and link it with the sliding needle 4 to realize the ejection and core pulling actions at the same time when opening the mold. There is no need to use a cylinder, which reduces costs, reduces the occupied space, and is not limited by the mold size space. The core pulling and ejection actions can be completed while the mold is opening, which can reduce the production cycle of the mold product, effectively prevent the product from sticking to the front mold core 2, and ensure the reliability of product ejection. The core pulling and ejection functions are combined into one on the core pulling and ejection mechanism, which greatly simplifies the structure, uses fewer parts, and reduces the abnormal failure rate during installation and mass production.

[0031] Figure 7 The figure shows a cross-sectional view of the front mold insert 3 in the ejection state under the push of the elastic member 6 after the mold is opened. The core pulling and ejection mechanism also includes a pressure guide rod 7, which is provided with a threaded section, an optical axis section and a pressure rod head 701 having a diameter greater than the diameter of the optical axis section from top to bottom. The bottom of the front mold insert 3 is located on one side of the molding position 301 and is provided with a countersunk hole 302. The pressure guide rod 7 passes through the countersunk hole 302 and is fixedly connected to the bottom of the first accommodating groove 201 through the threaded section; the front mold insert 3 is slidably matched with the optical axis section of the pressure guide rod 7, so that the front mold insert 3 can slide up and down on the pressure guide rod 7. The pressure rod head 701 of the pressure guide rod 7 is in the countersunk hole 302, and the pressure rod head 701 is used to stop the front mold insert 3 to limit its movement stroke.

[0032] Among them, the top of the front mold insert 3 is provided with a second accommodating groove 303 which is coaxial with and communicated with the countersunk hole 302. The elastic member 6 is a spring, which is arranged in the second accommodating groove 303 and is mounted on the optical axis section of the pressure-guiding rod 7. The two ends of the spring are elastically abutted against the front mold core 2 and the front mold insert 3 respectively, so that the spring can always apply an elastic force to the front mold insert 3 in the direction of the mold cavity.

[0033] Figure 8 The figure shows a cross-sectional view of the slide needle 4 in the core-pulling state driven by the front mold insert 3 after the mold is opened. A positioning groove 202 is provided on the side of the front mold core 2 facing the front mold 1, and the inclined slide seat 5 is fixed in the positioning groove 202 by screws 8. An avoidance groove 203 is provided on the front mold core 2, and the middle part of the slide needle 4 is inserted in the avoidance groove 203. The avoidance groove 203 is used to provide an avoidance space for the slide needle 4 when it moves along the inclined slide seat 5.

[0034] See also Figure 4and Figure 5 , an inclined slide seat 5 is provided with an inclined slide groove 501, and the inclined slide groove 501 is distributed at a set angle with the mold opening direction. Among them, the set angle is calculated based on the length of the front mold insert 3 that needs to be ejected and the length of the sliding needle 4 that needs to be pulled out. The upper end of the sliding needle 4 is slidably fitted in the inclined slide groove 501, and the sliding needle 4 is perpendicular to the inclined slide groove 501. In addition, the two side walls of the inclined slide groove 501 are provided with inclined convex ribs 502 along the length direction, and one end of the sliding needle 4 is provided with two limiting grooves 401, and the two limiting grooves 401 are correspondingly slidably matched with the two inclined convex ribs 502, so as to limit the sliding needle 4, so that the sliding needle 4 can only slide along the inclined slide groove 501 relative to the inclined slide seat 5.

[0035] The working principle of the utility model is as follows: after the product is injected and cooled in the mold closing state, the injection mold is opened, and the front mold insert 3 moves downward relative to the front mold core 2 under the elastic force of the spring, and the front mold insert 3 ejects the product from the front mold core 2 through the molding position 301; at the same time, the front mold insert 3 drives the sliding needle 4 to slide along the inclined sliding seat 5, so that the sliding needle 4 is pulled out from the undercut position on the product, thereby realizing the functions of front mold ejection and oblique demoulding.

[0036] It can be seen that when the injection mold of the utility model is opened, the front mold insert 3 is driven by the elastic member 6 and linked to the slide needle 4 to realize the ejection and core pulling actions at the same time. There is no need to use a cylinder, which reduces costs, reduces the occupied space, and is not limited by the size of the mold. The core pulling and ejection actions can be completed while the mold is opened, which can reduce the production cycle of the mold product, effectively prevent the product from sticking to the front mold core 2, and ensure the reliability of product ejection. The core pulling and ejection functions are combined into one on the core pulling and ejection mechanism, which greatly simplifies the structure, uses fewer parts, and reduces the abnormal failure rate during installation and mass production.

[0037] In the above description, many specific details are described to facilitate a full understanding of the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited by the specific implementation disclosed above. At the same time, any person familiar with the technical field can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. An injection mold with a front mold undercut core pulling and ejection mechanism, comprising a front mold (1) and a front mold core (2) fixed to the front mold (1), characterized in that: The front mold core (2) is provided with a core pulling and ejection mechanism, and the core pulling and ejection mechanism includes a front mold insert (3), a sliding needle (4), an inclined slide seat (5) and an elastic member (6). The front mold core (2) is provided with a first accommodating groove (201) on the side facing the mold cavity. The front mold insert (3) is movably arranged in the first accommodating groove (201) and is always subjected to an elastic force in the direction of the mold cavity by the elastic member (6). The front mold insert (3) is provided with a molding position (301) participating in the injection molding of the product. The front mold insert (3) is used to be opened by the elastic member (6) when the mold is opened. The component (6) pushes and ejects the product from the front mold core (2) through the molding position (301); the inclined slide seat (5) is fixedly arranged between the front mold (1) and the front mold core (2), one end of the sliding needle (4) is slidably connected to the inclined slide seat (5), and the other end of the sliding needle (4) passes through the front mold insert (3) and extends outwardly from the molding position (301) to be used for molding the undercut position on the product, and the sliding needle (4) can be driven by the front mold insert (3) to slide along the inclined slide seat (5) to be extracted from the undercut position on the product.

2. The injection mold with front mold undercut core pulling and ejection mechanism according to claim 1, characterized in that: The core pulling and ejection mechanism also includes a pressure guide rod (7); a countersunk hole (302) is provided on one side of the front mold insert (3) located at the molding position (301); one end of the pressure guide rod (7) passes through the countersunk hole (302) and is threadedly connected to the bottom of the first accommodating groove (201); the front mold insert (3) can slide up and down on the pressure guide rod (7); the other end of the pressure guide rod (7) is provided with a pressure rod head (701) located in the countersunk hole (302); the pressure rod head (701) is used to stop the front mold insert (3) to limit its movement stroke.

3. The injection mold with front mold undercut core pulling and ejection mechanism according to claim 2, characterized in that: The front mold insert (3) is provided with a second accommodating groove (303) coaxial with the countersunk hole (302), and the elastic member (6) is a spring, which is arranged in the second accommodating groove (303) and mounted on the pressure-guiding rod (7), and the two ends of the spring are elastically abutted against the front mold core (2) and the front mold insert (3) respectively.

4. The injection mold with front mold undercut core pulling and ejection mechanism according to claim 1, characterized in that: The inclined slide seat (5) is provided with an inclined slide groove (501) which is distributed at a set angle with the mold opening direction, and one end of the sliding needle (4) is slidably fitted in the inclined slide groove (501).

5. The injection mold with front mold undercut core pulling and ejection mechanism according to claim 4, characterized in that: Both side walls of the inclined sliding groove (501) are provided with inclined convex ribs (502), and one end of the sliding needle (4) is provided with two limiting grooves (401), and the two limiting grooves (401) are correspondingly slidably matched with the two inclined convex ribs (502).

6. The injection mold with front mold undercut core pulling and ejection mechanism according to claim 1, characterized in that: A positioning groove (202) is provided on the side of the front mold core (2) facing the front mold (1), and the inclined slide seat (5) is fixed in the positioning groove (202) by means of screws (8).

7. The injection mold with front mold undercut core pulling and ejection mechanism according to claim 1, characterized in that: The front mold core (2) is provided with an avoidance groove (203), the middle part of the sliding needle (4) is inserted into the avoidance groove (203), and the avoidance groove (203) is used to provide an avoidance space for the movement of the sliding needle (4).

8. The injection mold with front mold undercut core pulling and ejection mechanism according to claim 1, characterized in that: It also comprises a rear mold arranged opposite to the front mold (1) and a rear mold core fixed on the rear mold, wherein the rear mold core, the front mold core (2) and the front mold insert (3) together form a mold cavity for injection molding products.

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