A blind hole nut structure

Abstract

This utility model discloses a blind hole nut structure, including a nut body and a plug. The nut body has a through hole along the axial direction, which sequentially comprises a threaded connection section, a pin positioning section, and a plug mounting section. The threaded connection section is used for threaded connection with mating bolts, the pin positioning section is used for insertion and positioning with pins in the injection mold during plastic coating, and the plug mounting section can be fitted with a plug according to process requirements. The outer circumference of the nut body has at least one ring of helical teeth. When the helical teeth structure exceeds two rings, the inclination directions of adjacent sets of helical teeth are reversed. During electroplating, the plug is not installed to keep the through hole open and ensure that the electroplating solution fully wets the teeth. During plastic coating, the plug is installed in the plug mounting section and is fixed by curing through the injection molding solution that seeps in during the plastic coating process. At the same time, the helical teeth structure enhances the connection with the injection molded part, taking into account both the electroplating effect and the stability of plastic coating.

Description

Technical Field

[0001] This utility model belongs to the field of fastener technology, specifically relating to a blind hole nut structure suitable for plastic coating processes, which can be widely used in the manufacturing of products that require fully plastic-coated nut inserts, such as automobiles, electronics, and machinery. Background Technology

[0002] In the manufacturing of products in industries such as automotive, electronics, and machinery, it is very common for nut inserts to be fully plastic-coated with only one side exposed. This type of structure places high demands on the electroplating quality and plastic coating compatibility of the nut; however, existing blind-hole nuts have several technical drawbacks: Traditional blind hole nuts have a closed interior, and air bubbles are easily left at the bottom of the tooth pattern during the electroplating process. This prevents the electroplating solution from completely soaking the tooth pattern area, resulting in poor local electroplating. The product is prone to corrosion during subsequent use, which seriously affects the product's service life. The existing nut's outer peripheral structure design is unreasonable, resulting in insufficient clamping force when it is combined with the injection molded part. After plastic coating, it is prone to loosening and falling off, affecting the overall structural stability of the product. During the plastic coating process, the nuts lack a precise positioning structure and are prone to misalignment, resulting in a decrease in product assembly accuracy and failing to meet the manufacturing requirements of high-precision products.

[0003] Therefore, there is an urgent need for a blind hole nut structure that can solve the problems of incomplete electroplating, poor plastic coating positioning, and weak connection with injection molded parts, so as to balance the electroplating effect and the compatibility with the plastic coating process. Utility Model Content

[0004] To address the technical shortcomings of existing blind hole nuts, such as incomplete electroplating, low positioning accuracy of plastic coating, and insufficient bonding force with injection molded parts, this utility model provides a blind hole nut structure adapted to both plastic coating and electroplating processes, achieving the technical goals of fully wetting the tooth pattern with electroplating solution, accurate positioning of plastic coating, and firm connection with injection molded parts.

[0005] To achieve the above and other related objectives, the technical solution provided by this utility model is: a blind hole nut structure, comprising a nut body and a plug, wherein the nut body has a through hole extending axially, the through hole comprising a threaded connection section, a pin positioning section, and a plug mounting section arranged sequentially; the threaded connection section is used to achieve threaded connection with mating bolts; the pin positioning section is used to achieve insertion and positioning with pins in the injection mold during the plastic coating process; the plug mounting section remains continuous according to the product electroplating requirements, or is equipped with the plug according to the product plastic coating requirements.

[0006] The preferred technical solution is that the outer periphery of the nut body is provided with at least one ring of helical teeth.

[0007] The preferred technical solution is that when the helical tooth structure has more than two turns, the inclination directions of the helical teeth in two adjacent sets of helical tooth structures are set in opposite directions.

[0008] The preferred technical solution is that both the nut body and the plug are made of metal.

[0009] The preferred technical solution is that the plug and the plug installation section are fixedly connected by the curing of the injection molding liquid that seeps in during the plastic coating process.

[0010] Due to the application of the above technical solution, the beneficial effects of this utility model are as follows: More thorough electroplating effect: The through hole adopts a through-hole design, and there is no need to install a plug during electroplating. The electroplating solution can flow freely along the through hole and completely wet the bottom of the tooth pattern, avoiding air bubble residue. This solves the problems of poor electroplating and easy rusting of traditional blind hole nuts, and extends the service life of the product. Precise positioning during plastic coating: The pin positioning section is precisely connected to the injection mold pin, which effectively limits the displacement of the nut body during the plastic coating process and improves the product assembly accuracy; Strong connection: The outer peripheral helical tooth structure can enhance the mechanical interlocking force with the injection molded part, and the multiple reverse helical teeth further improve the pull-out resistance, preventing the nut from separating from the injection molded part after plastic wrapping; Wide process adaptability: The plug can be flexibly assembled according to the requirements of electroplating or plastic coating processes, without the need to design special nuts for different processes, reducing production costs and improving production efficiency. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the blind hole nut structure involved in this utility model.

[0012] Figure 2 This is a cross-sectional schematic diagram of the blind hole nut involved in this utility model in the injection molding state. Detailed Implementation

[0013] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0014] Please see Figures 1-2It should be noted that in the description of this utility model, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. These terms 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 component 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," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. The terms "horizontal," "vertical," and "suspended," etc., do not indicate that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0015] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example

[0016] like Figures 1 to 2 As shown, according to an overall technical concept of this utility model, a blind hole nut structure is provided, including a nut body 1 and a plug 2.

[0017] The nut body 1 is made of 304 stainless steel and has a through hole along the axial direction. The through hole is divided into a threaded connection section 11, a pin positioning section 12, and a plug mounting section 13 connected in sequence. The threaded connection section 11 is used to mate with bolts of the corresponding specifications; the pin positioning section 12 is used to mate with the pins 100 in the injection mold to ensure positioning accuracy during plastic coating; and the plug mounting section 13 is used to assemble with the plug 2.

[0018] The outer circumference of the nut body 1 is provided with a three-ring helical tooth structure 14, with the inclination direction of adjacent two rings of helical teeth being opposite (the first ring is clockwise, the second ring is counterclockwise, and the third ring is clockwise), which enhances the bonding force with the injection molded part.

[0019] The plug 2 is made of the same 304 stainless steel as the nut body 1 and is fitted with the plug mounting section 13.

[0020] Process Application Instructions Electroplating process: Without assembling the plug 2, the nut body 1 is placed in the electroplating solution. The electroplating solution flows along the through hole through the threaded connection section 11, the pin positioning section 12 and the plug installation section 13, completely wetting the bottom of the thread, with no air bubbles remaining, achieving comprehensive and uniform electroplating. Plastic coating process: The plug 2 is inserted into the plug installation section 13, and then the nut body 1 is placed into the injection mold. The insert pin of the injection mold is inserted into the insert positioning section 12 to achieve positioning. After the injection liquid is injected, some of the injection liquid seeps into the gap between the plug 2 and the plug installation section 13. After curing, the plug 2 and the nut body 1 are fixedly connected. At the same time, the helical tooth structure 14 engages with the injection liquid to form a solid overall structure.

[0021] The blind hole nut structure in this embodiment not only solves the problem of incomplete electroplating in traditional blind hole nuts, but also ensures the positioning accuracy and connection firmness during plastic coating, thus meeting the full plastic coating production requirements of automotive electronic components.

[0022] The beneficial effects of this blind hole nut structure are closely based on its core technical features, specifically as follows: First, the selective assembly design of "plug installation section + plug" based on the through hole means that the plug is not installed during electroplating, and the through hole remains open. This completely avoids the problem of air bubbles remaining at the bottom of the thread caused by the internal sealing of traditional blind holes, allowing the electroplating solution to fully wet the threaded connection section, solving local electroplating defects, effectively preventing rusting in subsequent use, and significantly extending the product life. Second, the pin positioning section of the through hole precisely engages with the injection mold pin, which can firmly fix the position of the nut body during the plastic wrapping process, preventing the nut from deviating. First, the nut's outer circumference features a helical tooth structure (at least one turn, with adjacent helical teeth reversing direction when there are more than two turns), which significantly enhances the mechanical engagement with the injection-molded part, improves torsional resistance, prevents the nut from loosening and falling off after plastic coating, and strengthens connection stability. Furthermore, the metal nut body and plug, combined with the method of fixing the plug by curing the injection molding liquid during plastic coating, further ensure the overall structural robustness, ultimately achieving a balance between thorough electroplating, precise plastic coating, and connection stability, adapting to the manufacturing needs of fully plastic-coated products in various fields such as automotive and electronics.

[0023] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A blind hole nut structure, characterized in that: The product includes a nut body and a plug. The nut body has an axially penetrating through hole, which includes a threaded connection section, a pin positioning section, and a plug mounting section arranged sequentially. The threaded connection section is used to achieve a threaded connection with a mating bolt. The pin positioning section is used to achieve insertion and positioning with a pin in the injection mold during the plastic coating process. The plug mounting section remains continuous according to the product electroplating requirements, or the plug is assembled according to the product plastic coating requirements.

2. The blind hole nut structure according to claim 1, characterized in that: The outer circumference of the nut body is provided with at least one ring of helical teeth.

3. The blind hole nut structure according to claim 2, characterized in that: When the helical tooth structure has more than two turns, the helical teeth of the two adjacent sets of helical tooth structures are set in opposite directions.

4. The blind hole nut structure according to claim 1, characterized in that: Both the nut body and the plug are made of metal.

5. The blind hole nut structure according to claim 1, characterized in that: The plug and the plug mounting section are fixedly connected by the curing of the injection molding liquid that seeps in during the plastic coating process.

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