Fastener for cold forming injection molding

Abstract

The utility model discloses a fastener for cold forming injection molding, the fastener is provided with a first end and a second end which are opposite along the axial direction of the fastener, the fastener comprises an insert head, a plurality of planes are arranged on the peripheral wall of the insert head, and the plurality of planes form a regular polygon on a plane vertical to the axial direction; one end of the conical part is connected to the second end of the insert head part; the turnup part is connected to the other end of the conical part, and the turnup part inclines from inside to outside from the first end to the second end; the plurality of concave parts are concave inwards and are connected with the insert head part and the conical part; and the connecting part is used for fixedly connecting the fastener with an external part. The fastener for cold forming injection molding is simple to process and easy to form, meanwhile, the risk that the fastener falls off from an injection molding part can be effectively reduced, and the connection reliability between the fastener and the injection molding part is remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of fasteners for injection molding, and specifically to a fastener for cold forming injection molding. Background Technology

[0002] Fasteners for injection molding typically refer to fastening elements pre-embedded or embedded during the injection molding process of plastic products, such as nuts, screws, locating pins, and connectors, primarily made of metal. With the widespread application of plastic products in various industrial fields, especially in the automotive, electronics, home appliance, medical device, and communication equipment industries, the requirements for the connection, assembly, and structural strength of plastic parts are constantly increasing. As crucial components for strengthening the connection performance of plastic parts and improving their mechanical strength and service life, injection molding fasteners are finding increasingly widespread use.

[0003] However, most existing injection molding fasteners are machined by turning. Fasteners suitable for turning have low material utilization, slow processing speed, and relatively high production costs, making them unsuitable for mass production at low cost. This invention provides a cold-forming injection molding fastener that, compared to machined fasteners, has a simpler structure and is less prone to detaching from the plastic, thus having broad application prospects. Utility Model Content

[0004] To overcome the above shortcomings, the purpose of this utility model is to provide a fastener for cold forming injection molding that is simple to process, easy to form, and can effectively reduce the risk of fasteners falling off the injection molded part, and significantly improve the connection reliability between the fastener and the injection molded part.

[0005] Technical solution: This utility model discloses a fastener for cold forming injection molding, the fastener having a first end and a second end opposite to each other along its axial direction, including:

[0006] The insert head has several planes on its outer peripheral wall, and the planes form a regular polygon in a plane perpendicular to the axial direction.

[0007] A tapered portion, one end of which is connected to the second end of the insert head;

[0008] A flange portion, which is connected to the other end of the tapered portion, and the flange portion slopes from the inside to the outside from the first end to the second end;

[0009] Several recessed portions, which are recessed inward and connect the insert head to the tapered portion;

[0010] A connecting part, which is used to securely connect the fastener to an external part.

[0011] Furthermore, the number of recesses is the same as the number of planes, and each recess is aligned with the center of a plane.

[0012] Furthermore, the diameter of the first end of the tapered portion is larger than the diameter of the second end.

[0013] Furthermore, the connecting portion is a threaded hole that penetrates the fastener axially.

[0014] Furthermore, the connecting part is a connector that is connected to the first end of the insert head.

[0015] Furthermore, the fastener is made of carbon steel.

[0016] Furthermore, the cross-section of the flange portion perpendicular to the axial direction is circular.

[0017] Furthermore, the cross-section of the flange portion perpendicular to the axial direction is polygonal.

[0018] The beneficial effects of this utility model are as follows:

[0019] (1) By setting several planes at the head of the insert, this utility model can effectively prevent the fastener from rotating during the injection molding process and improve the bonding force between the fastener and the injection molded part.

[0020] (2) By setting a tapered part and several recessed parts, the fastener can further enhance its interlocking force with the plastic material during the injection molding process, thereby improving its pull-out resistance.

[0021] (3) The flanged part can be deformed by the pressure of the upper and lower molds during injection molding, thereby preventing overflow material from entering the fastener. Attached Figure Description

[0022] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, under the guidance of this invention, can select various possible shapes and proportions to implement this invention according to specific circumstances. In the drawings:

[0023] Figure 1 This is a schematic diagram of the fastener structure of Embodiment 1 of this utility model;

[0024] Figure 2 This is a front view of the fastener of Embodiment 1 of this utility model;

[0025] Figure 3 This is a cross-sectional view of the fastener according to Embodiment 1 of this utility model;

[0026] Figure 4 This is a schematic diagram of the fastener according to Embodiment 2 of this utility model;

[0027] Figure 5 This is a schematic diagram of the fastener according to Embodiment 2 of this utility model;

[0028] Figure 6 This is a schematic diagram of the fastener according to Embodiment 2 of this utility model;

[0029] Figure 7 This is a schematic diagram of the injection molding of the fastener according to Embodiment 1 of this utility model.

[0030] In the figure: 11, first end; 12, second end; 2, insert head; 21, plane; 3, tapered part; 4, flanged part; 5, recessed part; 6, connecting part. Detailed Implementation

[0031] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0032] In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for 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. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. The implementation methods of this utility model will now be described based on its overall structure.

[0033] Example 1

[0034] like Figures 1 to 3 As shown, this utility model provides a fastener for cold forming injection molding, the fastener having a first end 11 and a second end 12 opposite to each other along its axial direction, including:

[0035] The insert head 2 has a plurality of planes 21 on its outer peripheral wall, and the plurality of planes 21 form a regular polygon on the planes 21 perpendicular to the axial direction.

[0036] A tapered portion 3, one end of which is connected to the second end 12 of the insert head 2;

[0037] A flange 4 is connected to the other end of the tapered portion 3, and the flange 4 is inclined from the inside to the outside from the first end 11 to the second end 12.

[0038] Several recessed portions 5, which are recessed inward and connect the insert head 2 and the conical portion 3;

[0039] Connecting part 6, which is used to fix the fastener to an external part.

[0040] With the above structure, the outer peripheral wall of the insert head 2 is provided with a number of planes 21. These planes 21 can form a regular polygon structure on the planes 21 perpendicular to the axis around the axis. These planes 21 can increase the contact area between the fastener and the plastic part, thereby preventing the insert from rotating or loosening after injection molding.

[0041] Extending from the insert head 2 to the second end 12, a plurality of recesses 5 are provided. The recesses 5 are recessed inward to form a groove-shaped or trench-shaped transition area. One end of these recesses 5 is connected to the insert head 2, and the other end is connected to the conical part 3. The recesses 5 are used to accommodate plastic during injection molding, thereby achieving the effect of plastic covering to enhance the interlocking force and thus achieving the function of anti-torsion.

[0042] like Figure 7 As shown, the other end of the tapered part 3 is connected to the flange part 4. The flange part 4 is structurally inclined from the inside to the outside, and gradually extends outward from the first end 11 to the second end 12 to form an angled flange, which serves as a stop to prevent the fastener from overflowing into its interior during injection molding.

[0043] The connecting part 6 is used to achieve a fixed connection between the fastener and external parts. Its specific form can be designed as an internal thread, a smooth rod, or other connection structure according to different application requirements, to adapt to different assembly methods and usage scenarios. The fastener of this invention has excellent anti-rotation and anti-pull-out performance, effectively improving the bonding strength between the injection molded part and the fastener, and is suitable for various injection molded structures. Compared with traditional machined fasteners, this invention is manufactured using cold forming, making it easier to cold-forge in structure, thus possessing advantages such as high efficiency, low cost, and suitability for mass production.

[0044] Preferably, the number of recesses 5 is the same as the number of cutting planes 21, and each recess 5 is aligned with the center of the corresponding cutting plane 21. This allows the fastener to distribute the stress inside the plastic part more evenly when under load, avoiding deformation caused by local stress concentration. Simultaneously, the aligned arrangement allows the plastic to more fully fill the recesses 5 during injection molding, enhancing the interlocking force and mechanical locking force between the plastic and the fastener. This further improves the fastener's anti-rotation and anti-pull-out performance in the plastic part, enhancing the overall structural stability and durability.

[0045] Preferably, the diameter of the first end 11 of the tapered portion 3 is larger than the diameter of the second end 12. The tapered portion 3 as a whole gradually tapers from the first end 11 to the second end 12, which can guide the plastic material to flow axially and fully cover the fastener during injection molding. After the plastic cools, the tapered structure of the tapered portion 3 forms a natural mechanical lock, which significantly improves the pull-out resistance of the fastener in the plastic part and prevents the fastener from sliding or coming out axially under force, thereby enhancing the overall stability and service life of the connector.

[0046] Furthermore, the connecting part 6 is a threaded hole that penetrates the fastener axially, allowing external connectors, such as screws and bolts, to be directly screwed in and securely connected to the fastener. This not only facilitates assembly and improves assembly efficiency but also provides reliable axial tensile load-bearing capacity during use. Simultaneously, the through-hole threaded hole structure ensures more even stress distribution on the fastener, effectively preventing damage caused by concentrated local stress.

[0047] The fasteners are made of carbon steel, a material with excellent mechanical strength and wear resistance, enabling them to withstand significant tensile, shear, and torsional loads during use without easily deforming or damaging. Existing injection-molded fasteners have relatively low strength and cannot meet the required connection strength. Carbon steel can meet the strength requirements of fasteners at levels 8 or 10, and also possesses good machinability and cold-forming properties, facilitating the creation of complex fastener structures, improving production efficiency, and reducing manufacturing costs.

[0048] Preferably, the flange 4 has a circular or polygonal structure in the cross section perpendicular to the axial direction, which can achieve uniform stress distribution and avoid cracking or deformation of plastic parts due to uneven local stress at the edge.

[0049] The circular flange 4 helps the plastic material flow smoothly during injection molding, improves the integrity of the overmolding, thereby enhancing the fixing effect of the fastener in the plastic body and improving the stability and durability of the overall connection.

[0050] Alternatively, the flange 4 can have a polygonal structure in a cross section perpendicular to the axial direction, which can increase the mechanical interlocking force between the flange 4 and the plastic material, effectively improve the anti-rotation performance, and prevent the fastener from loosening or slipping during use.

[0051] Example 2

[0052] like Figures 4 to 6As shown, the difference between this embodiment and Embodiment 1 is that the connecting part 6 is a connector disposed at the first end 11 of the insert head 2. The connector can be designed as a screw, bolt, plug-in rod, ball head bolt, or other form of connection structure according to different application scenarios. The connector is arranged along the axial direction of the fastener, with one end fixed to the insert head 2 and the other end used for connection or positioning with external parts. The connecting part 6 not only facilitates pre-assembly with external components after injection molding but also helps to accurately position and fix the fastener during the injection molding process, avoiding displacement or eccentricity.

[0053] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A fastener for cold forming injection molding, characterized in that, The fastener has a first end and a second end opposite to each other along its axial direction, including: The insert head has several planes on its outer peripheral wall, and the planes form a regular polygon in a plane perpendicular to the axial direction. A tapered portion, one end of which is connected to the second end of the insert head; A flange portion, which is connected to the other end of the tapered portion, and the flange portion slopes from the inside to the outside from the first end to the second end; Several recessed portions, which are recessed inward and connect the insert head to the tapered portion; A connecting part, which is used to securely connect the fastener to an external part.

2. The fastener for cold forming injection molding according to claim 1, characterized in that, The number of recesses is the same as the number of planes, and each recess is aligned with the center of a plane.

3. The fastener for cold forming injection molding according to claim 1, characterized in that, The diameter of the first end of the tapered portion is greater than the diameter of the second end.

4. The fastener for cold forming injection molding according to claim 1, characterized in that, The connecting part is a threaded hole that penetrates the fastener axially.

5. The fastener for cold forming injection molding according to claim 1, characterized in that, The connecting part is a connector that is connected to the first end of the insert head.

6. The fastener for cold forming injection molding according to claim 1, characterized in that, The fasteners are made of carbon steel.

7. The fastener for cold forming injection molding according to claim 1, characterized in that, The cross-section of the flanged portion perpendicular to the axial direction is circular.

8. The fastener for cold forming injection molding according to claim 1, characterized in that, The cross-section of the flanged portion perpendicular to the axial direction is polygonal.

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