Injection mold with function of preventing plastic from entering

Abstract

The utility model discloses an injection mold with a function of preventing plastic cement from entering, which belongs to the technical field of injection molds, and comprises a lower mold and an upper mold, the lower mold is provided with a concave hole, the injection mold also comprises an elastic needle, the upper mold is provided with a control cavity and a sliding hole, and the control cavity is provided with an elastic needle. The control cavity is located above the sliding hole, the vibrating needle is connected into the control cavity in a sliding mode, and the bottom of the vibrating needle can stretch out of the bottom of the upper die through the sliding hole. A spring is arranged at the top of the vibrating needle; the bottom of the vibrating needle can be pressed on the top of the concave hole; through the design of the vibrating needle and the spring, the vibrating needle can extend out of the bottom of the upper mold, even if a metal piece is forgotten to be placed, the vibrating needle is attached to the top of the concave hole to block the concave hole, plastic is prevented from flowing into the concave hole, and the concave hole is prevented from being blocked; and moreover, during normal injection molding, after the metal piece is placed, the bottom of the elastic needle can synchronously press the metal piece in the injection molding process, and meanwhile, the improvement of the injection molding yield is promoted.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to an injection mold with a function of preventing plastic from entering. Background Art

[0002] Injection molding, also known as injection molding, is a molding process that combines both injection and molding. Its advantages include high production speed, high efficiency, and a wide variety of designs, making it suitable for mass production and complex-shaped products. During the injection molding process, molten material is injected into the molding cavity under high pressure using an injection molding machine. The resulting product solidifies after cooling. This process is widely used in the production of spare parts across various industries, including digital product accessories, such as the back covers of mobile phones and watches.

[0003] When injection molding the back cover of a phone watch, because it needs to be waterproof, the metal parts of the charging contacts must be injection molded together to make them tightly combined together. Therefore, during injection molding, the mold must first place the metal parts in the specified position of the mold, and then perform injection molding to integrate them with the back cover. At the same time, in order to quickly and conveniently place the metal parts in the specified position and avoid displacement during injection molding, a concave hole matching the protrusion of the metal part will be opened below the position where the metal part is placed in the mold, and the concave hole will be engaged with the protrusion of the metal part to fix the metal part.

[0004] During the mold injection molding process, due to negligence or other reasons, the metal parts are often omitted before injection molding. At this time, the plastic of the product will flow into the recessed hole where the metal parts are placed, causing the recessed hole to be blocked, making it impossible to further place the metal parts, and then the mold must be taken off the machine for repair. However, existing injection molds do not prevent plastic from entering the recessed hole when the metal parts are omitted and injection molding is carried out directly.

[0005] In order to avoid the concave hole from being blocked, we propose an injection mold with a function of preventing plastic from entering, that is, preventing plastic from being injected into the concave hole during injection molding. Utility Model Content

[0006] The purpose of the utility model is to solve the problem in the prior art that when a metal piece is omitted, the concave hole cannot be prevented from being blocked by plastic, and an injection mold with the function of preventing plastic from entering is proposed.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0008] An injection mold with a function of preventing plastic from entering, comprising a lower mold and an upper mold, wherein the lower mold is provided with a concave hole, and further comprising: a spring pin; the upper mold is provided with a control cavity and a sliding hole, wherein the control cavity is located above the sliding hole; the spring pin is slidably connected in the control cavity, and the bottom of the spring pin can protrude from the bottom of the upper mold through the sliding hole; a spring is provided at the top of the spring pin, wherein the spring is located in the control cavity; and the bottom of the spring pin can be pressed against the top of the concave hole.

[0009] Preferably, the recessed hole is a through hole.

[0010] Preferably, the number of the concave holes is multiple groups, and the number of the spring pins corresponds to the number of the concave holes. Preferably, the concave holes are designed in two groups.

[0011] Preferably, a gasket is slidably connected in the control cavity, and the gasket is in contact with the tops of the multiple groups of elastic pins; the bottom of the spring is against the top of the gasket.

[0012] Preferably, a pressure plate is fixedly connected to the top of the upper mold, and the top of the spring abuts against the bottom of the pressure plate.

[0013] Preferably, a groove is formed at the bottom of the pressure plate, the groove is communicated with the control chamber, and part of the spring is located in the groove.

[0014] Preferably, a pressing plate is fixedly connected to the top of the upper mold, and the top of the spring abuts against the bottom of the pressing plate.

[0015] Preferably, a receiving cavity is passed through the top of the upper mold, the receiving cavity is communicated with the control cavity, and the pressing sheet is detachably arranged in the receiving cavity.

[0016] Preferably, the elastic pin includes an abutment structure and a connecting rod structure, the connecting rod structure is connected to one side of the abutment structure, the connecting rod structure is slidably disposed in the concave hole, and the diameter of the abutment structure is larger than the diameter of the concave hole.

[0017] Compared with the prior art, the present invention provides an injection mold with a function of preventing plastic from entering, which has the following beneficial effects:

[0018] 1. This injection mold, which has a function of preventing plastic from entering, has a spring-loaded pin and spring design that allows the pin to protrude from the bottom of the upper mold. Even if the metal part is forgotten to be placed, the pin will contact the top of the recessed hole, blocking the recessed hole and preventing plastic from flowing into the recessed hole and causing blockage. In addition, during normal injection molding, after the metal part is placed, the bottom of the pin will also press the metal part during the injection molding process, which also promotes the improvement of the injection molding yield.

[0019] 2. The injection mold with the function of preventing plastic from entering can make the force exerted by the spring on multiple groups of spring pins more uniform through the gasket, so that the force exerted by each group of spring pins on the concave hole or metal part is the same, or the difference is within a controllable range. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the structure of an injection mold with a function of preventing plastic from entering the mold. Figure 1 ;

[0021] Figure 2 is a schematic diagram of the structure of an injection mold with a function of preventing plastic from entering the mold. Figure 2 ;

[0022] Figure 3 is a schematic diagram of the structure of an injection mold with a function of preventing plastic from entering the mold. Figure 3 ;

[0023] Figure 4 shows an injection mold with a function of preventing plastic from entering the mold. Figure 3 Enlarged view of part A;

[0024] FIG5 is a schematic structural diagram of a slide hole of an injection mold with a function of preventing plastic from entering, proposed by the present invention;

[0025] FIG6 is a schematic structural diagram of an injection mold gasket with the function of preventing plastic from entering the mold according to the present invention;

[0026] Figure 7 is a schematic diagram of the structure of an injection molded product with a function of preventing plastic from entering the mold according to the present invention. Figure 1 ;

[0027] Figure 8 is a schematic diagram of the structure of an injection molded product with a function of preventing plastic from entering the mold according to the present invention. Figure 2 ;

[0028] Figure 9 is a schematic diagram of the structure of an injection molded product with a function of preventing plastic from entering the mold according to the present invention. Figure 3 ;

[0029] FIG10 is a schematic structural diagram of an upper mold of an injection mold with a function of preventing plastic from entering, proposed by the present invention;

[0030] FIG11 is a schematic structural diagram of a lower mold of an injection mold with a function of preventing plastic from entering, proposed by the present invention;

[0031] Figure 12 is a schematic diagram of the structure of an injection mold with a function of preventing plastic from entering the mold according to the present invention. Figure 4 ;

[0032] FIG13 is an enlarged view of part B in FIG12 of an injection mold with a function of preventing plastic from entering, proposed by the present invention;

[0033] FIG14 is a schematic structural diagram of an injection mold pressing sheet with a function of preventing plastic from entering, as proposed by the present invention.

[0034] In the figure: 1. Lower mold; 101. Upper mold; 102. Injection port; 2. Injection molded product; 201. Metal part; 202. Concave hole; 3. Control cavity; 301. Sliding hole; 302. Spring pin; 303. Gasket; 304. Spring; 4. Press plate; 401. Pressing piece. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0036] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0037] Example 1:

[0038] Referring to Figures 1 to 13, an injection mold with a function of preventing plastic from entering includes a lower mold 1 and an upper mold 101. The lower mold 1 is provided with concave holes 202. The number of concave holes 202 is multiple groups, such as 2-6 groups, preferably two groups. Because most phone watches have two groups of charging contacts, the number of spring pins 302 corresponds to the number of concave holes 202, that is, the same. During injection molding, Figure 4 11 , the metal member 201 of the charging contact is placed in the recessed hole 202 and engages with the raised portion of the metal member 201 . This embodiment discloses a method for preventing the entry of plastic.

[0039] The functional injection mold further includes a spring pin 302. The upper mold 101 is provided with a control cavity 3 and a slide hole 301. The control cavity 3 is located above the slide hole 301. The spring pin 302 is slidably connected in the control cavity 3. One end of the spring pin 302, that is, the bottom of the spring pin 302, can be extended from the bottom of the upper mold 101 through the slide hole 301. The shape of the spring pin 302 is as follows: Figure 2 3 , it is a stepped shaft with a large top diameter and a small bottom diameter. It should be noted that the top is the top and the bottom is the bottom. The top can only slide in the control cavity 3 , while the bottom slides in the sliding hole 301 and can protrude from the bottom of the sliding hole 301 .

[0040] A spring 304 is provided at the other end of the spring pin 302, i.e., at the top of the spring pin 302. The spring 304 is located in the control chamber 3. The spring pin 302 exerts a force on the top of the spring pin 302 so that, in the initial state, i.e., in the absence of external force, the bottom of the spring pin 302 protrudes from the bottom of the sliding hole 301. Then, the bottom of the spring pin 302 can press against the top of the recessed hole 202.

[0041] The spring pin 302 is located directly above the recessed hole 202 .

[0042] During injection molding, as shown in FIG11 , the worker first engages the metal part 201 in the concave hole 202 of the lower mold 1, and then the upper mold 101 moves downward to close with the lower mold 1. The closing portion of the lower mold 1 and the upper mold 101 is provided with an injection port 102 for injecting plastic. Then, injection molding is performed through the injection port 102 to form an injection molded product 2, which is the back cover of the phone watch mentioned in the background art. Figure 8 and Figure 9 , the injection molded product 2 is integrated with the metal part 201, and the injection molding is completed.

[0043] During the injection molding process, if the metal piece 201 is forgotten to be placed, as shown in Figures 12 and 13, the spring 304 will cause the spring pin 302 to continue to move downward until its bottom touches the top of the recessed hole 202, blocking the recessed hole 202 and preventing the plastic from flowing into the recessed hole 202, causing the recessed hole 202 to be blocked. This will prevent the subsequent placement of the metal piece 201 and cause the process to be unable to continue.

[0044] Injection molding operations can only be done by taking the machine off to repair the mold, resulting in losses.

[0045] Furthermore, during the injection molding process, after the metal part 201 is placed, the upper mold 101 moves downward and closes with the lower mold 1. Under the action of the spring 304, the bottom of the spring pin 302 contacts the metal part 201, pressing the metal part 201, and further preventing the metal part 201 from displacement, thereby improving the injection molding yield.

[0046] That is, through the design of the spring pin 302 and the spring 304, the spring pin 302 can protrude from the bottom of the upper mold 101. Even if the metal part 201 is forgotten to be placed, the spring pin 302 will contact the top of the recessed hole 202, blocking the recessed hole 202, thereby preventing plastic from flowing into the recessed hole 202 and thus avoiding clogging of the recessed hole 202. In addition, during normal injection molding, after the metal part 201 is placed, the bottom of the spring pin 302 will also simultaneously press the metal part 201 during the injection molding process, thereby promoting the improvement of the injection molding yield rate.

[0047] It should be noted that the spring pin 302 includes an abutment structure and a connecting rod structure. The connecting rod structure is connected to one side of the abutment structure and is slidably disposed in the recessed hole 202. The diameter of the abutment structure is larger than the diameter of the recessed hole 202, while the diameter of the connecting rod structure is smaller than or equal to the diameter of the recessed hole 202. This gives the spring pin 302 a stepped shaft shape with a larger diameter at the top and a smaller diameter at the bottom. If the metal component 201 is forgotten, when the bottom of the spring pin 302 contacts the top of the recessed hole 202, as shown in FIG12 , the lower surface of the larger diameter portion of the spring pin 302 will not contact the bottom of the control chamber 3, leaving a certain gap. In other words, at this time, the spring 304 will still be compressed and will still exert force on the spring pin 302.

[0048] The recessed hole 202 is a through hole, which is convenient for subsequent maintenance. Even if a small amount of plastic appears in the recessed hole 202 during subsequent injection molding, it can be easily cleaned through the through hole. It cooperates with the spring pin 302 to form a double insurance.

[0049] A gasket 303 is slidably connected in the control chamber 3 , and the gasket 303 contacts the tops of the multiple groups of elastic pins 302 ; the bottom of the spring 304 abuts against the top of the gasket 303 .

[0050] The gasket 303 can make the force exerted by the spring 304 on the multiple groups of elastic pins 302 more uniform, so that the force exerted by each group of elastic pins 302 on the recessed hole 202 or the metal part 201 is the same, or the difference is within a controllable range.

[0051] Example 2

[0052] The same as Example 1, based on Example 1, further steps are:

[0053] 1 to 3 and 12 , a pressing plate 4 is fixedly connected to the top of the upper mold 101 , and the top of the spring 304 abuts against the bottom of the pressing plate 4 .

[0054] In some embodiments, the bottom of the pressure plate 4 is provided with a groove that communicates with the control chamber 3, and a portion of the spring 304 is located within the groove. A corresponding groove is provided on the side of the pressure plate 4 facing the control chamber 3, communicating with the control chamber 3. A portion of the spring 304 can be located within the groove and connected to the bottom of the groove.

[0055] In order to facilitate installation, the top of the control cavity 3 is set to be open, and the elastic pin 302, gasket 303 and spring 304 are placed into the control cavity 3 in sequence. Then, the top of the upper mold 101 is fixed with the pressure plate 4 by bolts to complete the installation.

[0056] Example 3:

[0057] The same as Example 2, based on Example 2, further:

[0058] If space is limited, a pressing plate 4 cannot be added to the top of the upper mold 101, because adding a pressing plate 4 will undoubtedly increase the thickness of the upper mold 101. When the on-site injection molding environment does not allow the thickness of the upper mold 101 to be increased:

[0059] 14 , a pressing piece 401 is fixedly connected to the top of the upper mold 101 , and the top of the spring 304 abuts against the bottom of the pressing piece 401 .

[0060] In some embodiments, a receiving cavity is formed through the top of the upper mold 101, which is in communication with the control chamber 3. The pressing piece 401 is detachably mounted in the receiving cavity. The pressing piece 401 is detachably mounted using screws. The size of the receiving cavity is adapted to the size and shape of the pressing piece 401, so that the pressing piece 401 can be securely fastened therein. This ensures that the pressing piece 401 can be fully embedded in the upper mold.

[0061] A groove can be opened on the top of the upper mold 101, and the control cavity 3 is located in the groove. After the elastic pin 302, gasket 303 and spring 304 are installed, the pressing piece 401 is fixed in the groove by screws to press the spring 304 to complete the installation.

[0062] The thickness of the pressing sheet 401 is the same as the depth of the groove.

[0063] The threaded holes on the pressing piece 401 used for fixing are also countersunk holes, so that the height of the screws will not be higher than the top height of the upper mold 101.

[0064] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An injection mold with a function of preventing plastic from entering, comprising a lower mold (1) and an upper mold (101), wherein the lower mold (1) is provided with a concave hole (202), characterized in that: Also includes: The elastic needle (302) is provided with a control cavity (3) and a sliding hole (301) on the upper mold (101), the control cavity (3) is located above the sliding hole (301), the elastic needle (302) is slidably connected in the control cavity (3), and the bottom of the elastic needle (302) can be extended from the bottom of the upper mold (101) through the sliding hole (301); A spring (304) is provided on the top of the elastic needle (302), and the spring (304) is located in the control chamber (3); The bottom of the elastic pin (302) can be pressed against the top of the concave hole (202).

2. The injection mold with the function of preventing plastic from entering according to claim 1, characterized in that: The concave hole (202) is a through hole.

3. An injection mold with a function of preventing plastic from entering according to any one of claims 1-2, characterized in that: The number of the concave holes (202) is multiple groups, and the number of the elastic pins (302) corresponds one to one to the number of the concave holes (202).

4. The injection mold with the function of preventing plastic from entering according to claim 3, characterized in that: The recessed holes (202) are designed in two groups.

5. The injection mold with the function of preventing plastic from entering according to claim 3, characterized in that: A gasket (303) is slidably connected in the control cavity (3), and the gasket (303) is in contact with the tops of the multiple groups of elastic pins (302); The bottom of the spring (304) abuts against the top of the gasket (303).

6. The injection mold with the function of preventing plastic from entering according to claim 1, characterized in that: The top of the upper mold (101) is fixedly connected to a pressing plate (4), and the top of the spring (304) abuts against the bottom of the pressing plate (4).

7. The injection mold with the function of preventing plastic from entering according to claim 6, characterized in that: A groove is provided at the bottom of the pressure plate (4), the groove being in communication with the control chamber (3), and a portion of the spring (304) is located in the groove.

8. The injection mold with the function of preventing plastic from entering according to claim 1, characterized in that: The top of the upper mold (101) is fixedly connected to a pressing plate (401), and the top of the spring (304) abuts against the bottom of the pressing plate (401).

9. The injection mold with the function of preventing plastic from entering according to claim 8, characterized in that: The top of the upper mold (101) is penetrated by an accommodating cavity, the accommodating cavity is communicated with the control cavity (3), and the pressing sheet (401) is detachably arranged in the accommodating cavity.

10. The injection mold with the function of preventing plastic from entering according to claim 1, characterized in that: The elastic pin (302) comprises an abutment structure and a connecting rod structure, wherein the connecting rod structure is connected to one side of the abutment structure, and the connecting rod structure is slidably arranged in the concave hole (202), and the diameter of the abutment structure is larger than the diameter of the concave hole (202).

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