Welding-free terminal

Abstract

The utility model provides a welding-free terminal, which comprises a limiting part and at least one inserting part connected with the limiting part, the inserting part is of a symmetrical structure and is provided with a fisheye hole penetrating through the front side surface and the rear side surface of the inserting part, and the inserting part is sequentially provided with a pre-inserting area, an elastic area and a strength area connected with the limiting part from top to bottom; the fish-eye hole extends upwards to the pre-insertion area, the longitudinal interval L1 between the topmost point of the fish-eye hole and the elastic area is 0.02-0.06 mm, the transverse width of the insertion part at the joint of the pre-insertion area and the elastic area is equal to the diameter of a corresponding PCB through hole, the fish-eye hole extends downwards to the strength area, and the longitudinal interval L2 between the bottommost point of the fish-eye hole and the elastic area is 0.05-0.09 mm. According to the welding-free terminal, the optimal appearance and the shape of the fisheye hole are determined by analyzing the insertion and extraction process of the fisheye hole, so that the welding-free terminal has good insertion and extraction force under the condition that the plating layer of the PCB through hole is not damaged or the aperture deformation is not too large, and the reliability and durability of a connector are further ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of terminal production, and particularly relates to a welding-free terminal. Background Art

[0002] There are many ways to connect connectors to PCBs. Common methods include through-hole, surface mount (SMT), mixed mount, spring mount, and press-fit. A press-fit connector is defined as a pin (also known as a terminal) that is pressed into a hole smaller than its outer diameter. This type of connection is called press-fit, also known as crimping. The industry has designed various press-fit terminal configurations, each with its own advantages and disadvantages. Among them, solderless fisheye terminals are the most widely used press-fit terminal structure.

[0003] Solderless fisheye terminals connect to PCBs (printed circuit boards) by press-fitting, eliminating the need for solder. Their key advantages include low cost, high efficiency, simple operation, and high reliability. Due to their unique structural design, they are widely used in industries such as communications and computers. However, to ensure insertion stability, some solderless fisheye terminals have the potential to damage the plating of the PCB through-hole or cause excessive deformation of the hole diameter after insertion, rendering the PCB through-hole unusable when replacing the connector. Summary of the Invention

[0004] The utility model provides a solder-free terminal, which has good insertion and extraction force without damaging the plating of the PCB through hole or causing excessive deformation of the hole diameter, thereby ensuring the reliability and durability of the connector.

[0005] The technical solution adopted by this utility model is:

[0006] A solder-free terminal comprises a limiting portion and at least one plug-in portion connected to the limiting portion, the plug-in portion having a symmetrical structure and provided with a fisheye hole running through its front and rear side surfaces, the plug-in portion being composed, from top to bottom, of a pre-insertion area, an elastic area, and a strength area connected to the limiting portion, the transverse width of the plug-in portion located in the pre-insertion area gradually increasing from top to bottom, the transverse width of the plug-in portion located in the elastic area first gradually increasing and then decreasing from top to bottom, and the transverse width of the plug-in portion located in the strength area first gradually decreasing to a constant value and then increasing from top to bottom; the fisheye hole extends upward to the pre-insertion area, the longitudinal spacing L1 of the top point thereof from the elastic area being 0.02-0.06 mm, the transverse width of the plug-in portion at the connection between the pre-insertion area and the elastic area being equal to the diameter of the corresponding PCB through-hole, the fisheye hole extends downward to the strength area, the longitudinal spacing L2 of the bottom point thereof from the elastic area being 0.05-0.09 mm.

[0007] Preferably, the fisheye hole includes an upper hole area, a middle hole area and a lower hole area, the middle hole area gradually widens from top to bottom, the upper hole area gradually narrows from the top of the middle hole area upward, and the lower hole area gradually narrows from the lower end of the middle hole area downward, and the longitudinal length L3 of the upper hole area is smaller than the longitudinal length L4 of the lower hole area.

[0008] Preferably, the upper hole area is composed of a first inner arc surface located in the pre-insertion area, inner inclined surfaces arranged on both sides of the first inner arc surface, and a first inner transition arc surface connected to the inner inclined surface; the lower hole area is composed of a second inner arc surface located in the strength area, a first inner arc surface arranged on both sides of the second inner arc surface, and a second inner transition arc surface connected to the first inner arc surface; the middle hole area is composed of two left-right symmetrical second inner arc surfaces, and the second inner arc surfaces are respectively connected to the first inner transition arc surface and the second inner transition arc surface.

[0009] Preferably, the outer surface of the plug-in portion includes a guide bevel, a continuous curved surface, and a continuous transition surface. The guide bevel is located on the front and rear sides of the top of the plug-in portion and is close to each other. The continuous curved surface is located on the left and right sides of the top of the plug-in portion and is close to each other. The upper end thereof and the guide bevel together constitute a square pre-insertion top surface. The lower end of the continuous curved surface is connected to the limiting portion. The continuous transition surface is arranged between the front and rear side surfaces of the plug-in portion and the continuous curved surface. The upper end of the continuous transition surface is connected to the guide bevel, and the lower end thereof is connected to the limiting portion.

[0010] Preferably, the continuous curved surface includes a first outer inclined surface, a second outer inclined surface, a first outer arc-shaped surface, and a first outer curved arc-shaped surface connected in sequence from top to bottom, and the continuous transition surface includes a first outer transition surface, a second outer transition surface, a third outer transition surface, and a first outer curved transition surface connected in sequence from top to bottom, the first outer transition surface, the second outer transition surface, the third outer transition surface, and the first outer curved transition surface respectively correspond to and are connected with the first outer inclined surface, the second outer inclined surface, the first outer arc-shaped surface, and the first outer curved arc-shaped surface, the lower ends of the first outer inclined surface and the first outer transition surface are commonly connected to a rhombus-shaped smooth transition surface, and the lower ends of the rhombus-shaped smooth transition surface are connected to the second outer inclined surface and the second outer transition surface.

[0011] Compared with the prior art, the beneficial effect of the present invention is that the solder-free terminal of the present invention determines the optimal appearance and fisheye shape by analyzing the plugging and unplugging process of the fisheye hole, so that it has good insertion and extraction force without damaging the plating of the PCB through-hole or causing excessive deformation of the aperture, thereby ensuring the reliability and durability of the connector. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural diagram of the present utility model.

[0013] Figure 2 This is a structural diagram of the utility model from another angle.

[0014] Figure 3 for Figure 1 Left view of .

[0015] Figure 4 for Figure 1 Front view of.

[0016] In the figure: 1. limiting part; 2. plug-in part; 3. fisheye hole; 21. guiding inclined surface; 22. continuous curved surface; 23. continuous transition surface; 24. rhombus-shaped smooth transition surface; 221. first outer inclined surface; 222. second outer inclined surface; 223. first outer arcuate surface; 224. first outer curved arcuate surface; 231. first outer transition surface; 232. second outer transition surface; 233. third outer transition surface; 234. first outer curved transition surface; 31. upper hole area; 32. middle hole area; 33. lower hole area; 311. first inner arcuate surface; 312. inner inclined surface; 313. first inner transition arcuate surface; 331. second inner arcuate surface; 332. first inner arcuate surface; 333. second inner transition arcuate surface; 321. second inner arcuate surface. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with specific embodiments. The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual drawings. They should not be construed as limiting the present invention. It is understandable that some well-known structures and their descriptions may be omitted from the accompanying drawings.

[0018] The utility model provides a solder-free terminal, comprising a limiting portion 1 and at least one plug-in portion 2 connected to the limiting portion 1. The plug-in portion 2 is symmetrical in structure and is provided with a fisheye hole 3 running through the front and rear sides thereof. The plug-in portion is symmetrical in structure, which can be understood as being symmetrical left and right and front and back; the plug-in portion 2 is divided from top to bottom into a pre-insertion area, an elastic area, and a strength area connected to the limiting portion 1. The transverse width of the plug-in portion 2 located in the pre-insertion area gradually increases from top to bottom, the transverse width of the plug-in portion 2 located in the elastic area first gradually increases and then decreases from top to bottom, and the transverse width of the plug-in portion 2 located in the strength area first gradually increases from top to bottom. Gradually decreases to a constant value and then increases; the fisheye hole 3 extends upward to the pre-insertion zone, and the longitudinal spacing L1 between its top point and the elastic zone is 0.02-0.06mm. The transverse width of the plug-in portion where the pre-insertion zone and the elastic zone are connected is equal to the diameter of the corresponding PCB through-hole. This design can solve the problem of excessive interference between the elastic zone and the PCB through-hole at the beginning, causing deformation of the PCB through-hole; the fisheye hole 3 extends downward to the strength zone, and the longitudinal spacing L2 between its bottom point and the elastic zone is 0.05-0.09mm. This design can solve the problem of hard interference causing deformation of the PCB through-hole in order to increase the terminal retention force.

[0019] The pre-insertion zone facilitates terminal insertion, meaning it's pre-placed into the PCB through-hole for initial positioning. The elastic zone forms two simply supported beams through the fisheye hole, interfering with the PCB through-hole to generate insertion force (the first wave crest) and smooth insertion, generating insertion force (the second wave crest) and retention force. The strength zone provides the terminal's inherent strength to prevent buckling during insertion. Under this structure, the insertion and removal process of the fisheye hole is analyzed as follows:

[0020] (1) When the terminal is pre-inserted into the PCB through-hole, the tip of the terminal pre-insertion area enters without deformation;

[0021] (2) The elastic area of the terminal is pressed in. It is known that the transverse width of the plug-in portion where the elastic area and the pre-insertion area are connected is equal to the diameter of the corresponding PCB through-hole. At this time, the elastic area and the PCB through-hole begin to interfere with each other, the fisheye hole begins to deform, and the first peak of the insertion force appears during the pressing process. In the design, excessive interference should be avoided at the beginning to prevent the terminal from breaking due to excessive insertion force and the PCB through-hole from being severely deformed and difficult to recover. At this time, extending the fisheye hole appropriately to the pre-insertion area can increase the deformation of this part, which can better solve this problem.

[0022] (3) The elastic area of the terminal continues to be pressed in, and the fisheye hole is deformed. Since the two simply supported beams of the fisheye hole shrink inward as a whole, the overall width becomes smaller, which reduces the subsequent deformation and slightly reduces the insertion force;

[0023] (4) Continue to press down until the maximum width of the plug-in part enters the fisheye. Since the maximum width of the plug-in part corresponds to the maximum width of the fisheye hole, it can be understood that this part is relatively easy to deform. This part is not the position with the maximum insertion and extraction force;

[0024] (5) The elastic area of the terminal continues to enter the fisheye hole, interfering with the PCB through-hole. The insertion force has a second peak, and the terminal is pressed in, providing retention force. At this point, the entire elastic area and part of the pre-insertion area are inside the PCB through-hole.

[0025] To increase the terminal retention force, the interference between the terminal and the PCB through-hole will be increased as much as possible within the allowable range. That is, the interference force is increased by increasing the width and thickness of the simply supported beams on both sides of the fisheye hole. However, hard interference should be avoided at this time. The design of pressing the depth below the upper edge of the fisheye can effectively solve this problem. Therefore, the fisheye hole is extended downward to the strength zone.

[0026] Furthermore, the fisheye hole 3 comprises an upper hole area 31, a middle hole area 32, and a lower hole area 33. The middle hole area 32 gradually widens from top to bottom, the upper hole area 31 gradually narrows from the top of the middle hole area 32 upward, and the lower hole area 33 gradually narrows from the bottom of the middle hole area 32 downward. The longitudinal length L3 of the upper hole area 31 is less than the longitudinal length L4 of the lower hole area. Because the second peak of the insertion force is in the lower hole area and is greater than the first peak, the longitudinal length and lateral width of the lower hole area are both greater than those of the upper hole area, which reduces the difficulty of deformation. While firmly fixing the plug part, it is not easy to cause serious deformation of the PCB through-hole.

[0027] Specifically, the upper hole region 31 comprises a first inner arc surface 311 located in the pre-insertion zone, inner inclined surfaces 312 disposed on either side of the first inner arc surface 311, and a first inner transition arc surface 313 connected to the inner inclined surface 312. The lower hole region 33 comprises a second inner arc surface 331 located in the strength zone, first inner arc surfaces 332 disposed on either side of the second inner arc surface 331, and a second inner transition arc surface 333 connected to the first inner arc surface 332. The middle hole region 32 comprises two bilaterally symmetrical second inner arc surfaces 321, which are connected to the first inner transition arc surface 313 and the second inner transition arc surface 333, respectively. The first and second inner arc surfaces enhance the pressure-bearing capacity of this area. The first and second inner transition arc surfaces ensure the smoothness of the fisheye hole interior.

[0028] At the same time, the outer surface of the plug-in portion 2 includes a guiding bevel 21, a continuously curved surface 22, and a continuous transition surface 23. The guiding bevel 21 is located on the front and rear sides of the top of the plug-in portion 2 and is close to each other. The continuously curved surface 22 is located on the left and right sides of the top of the plug-in portion and is close to each other. The upper end thereof and the guiding bevel 21 together form a square pre-insertion top surface. The lower end of the continuously curved surface 22 is connected to the limiting portion 1. The continuous transition surface 23 is provided between the front and rear side surfaces of the plug-in portion 2 and the continuous curved surface 22. The upper end of the continuous transition surface 23 is connected to the guiding bevel 21, and the lower end thereof is connected to the limiting portion 1. The outer surface of the plug-in portion is designed based on the shape analysis of the fisheye hole, adapted to the force applied during the insertion and removal process of the fisheye hole, and can maintain good structural strength of the plug-in portion during the press-in process.

[0029] Furthermore, the continuous curved surface 22 includes a first outer inclined surface 221, a second outer inclined surface 222, a first outer arcuate surface 223, and a first outer curved arcuate surface 224 connected in sequence from top to bottom, and the continuous transition surface 23 includes a first outer transition surface 231, a second outer transition surface 232, a third outer transition surface 233, and a first outer curved transition surface 234 connected in sequence from top to bottom, the first outer transition surface 231, the second outer transition surface 232, the third outer transition surface 233, and the first outer curved transition surface 234 respectively correspond to and are connected to the first outer inclined surface 221, the second outer inclined surface 222, the first outer arcuate surface 223, and the first outer curved arcuate surface 224, the lower ends of the first outer inclined surface 221 and the first outer transition surface 231 are commonly connected to a rhombus-shaped smooth transition surface 24, and the lower ends of the rhombus-shaped smooth transition surfaces are connected to the second outer inclined surface 222 and the second outer transition surface 232. The smooth design of the outer surface of the plug part can effectively prevent the plating of the PCB through hole from being scratched when the plug part is pressed into.

[0030] More specifically, the guiding inclined surface 22, the first outer inclined surface 221 of the continuous curved surface 22, and the first outer transition surface 231 of the continuous transition surface 23 belong to the outer surface of the pre-insertion zone, the first outer arcuate surface 223 and the first outer curved arcuate surface 224 of the continuous curved surface 22, and the third outer transition surface 233 and the first outer curved transition surface 234 of the continuous transition surface 23 belong to the outer surface of the strength zone, and the outer surface of the elastic zone includes the first outer inclined surface 221 and the first outer transition surface 231 coplanar with the pre-insertion zone, the first outer arcuate surface 223 and the third outer transition surface 233 coplanar with the strength zone, the second outer inclined surface 222, the second outer transition surface 232 and the rhombus-shaped smooth transition surface 24.

[0031] The above describes in detail the optional implementation methods of the utility model examples in conjunction with the accompanying drawings. However, the implementation methods of the utility model are not limited to the specific details in the above implementation methods. Within the technical concept of the implementation methods of the utility model, various simple modifications can be made to the technical solutions of the implementation methods of the utility model. These simple modifications all fall within the protection scope of the implementation methods of the utility model.

Claims

1. A solder-free terminal, characterized in that: The invention comprises a limiting portion and at least one plug-in portion connected to the limiting portion, wherein the plug-in portion has a symmetrical structure and is provided with a fisheye hole running through the front and rear side surfaces thereof, and the plug-in portion is composed of a pre-insertion area, an elastic area and a strength area connected to the limiting portion from top to bottom. The transverse width of the plug-in portion located in the pre-insertion area gradually increases from top to bottom, the transverse width of the plug-in portion located in the elastic area first gradually increases and then decreases from top to bottom, and the transverse width of the plug-in portion located in the strength area first gradually decreases to a constant value and then increases from top to bottom; the fisheye hole extends upward to the pre-insertion area, and the longitudinal interval L1 between the top point and the elastic area is 0.02-0.06mm. The transverse width of the plug-in portion at the connection between the pre-insertion area and the elastic area is equal to the diameter of the corresponding PCB through-hole, and the fisheye hole extends downward to the strength area, and the longitudinal interval L2 between the bottom point and the elastic area is 0.05-0.09mm.

2. The solder-free terminal according to claim 1, wherein: The fisheye hole includes an upper hole area, a middle hole area and a lower hole area. The middle hole area gradually widens from top to bottom, the upper hole area gradually narrows from the top of the middle hole area upward, and the lower hole area gradually narrows from the lower end of the middle hole area downward. The longitudinal length L3 of the upper hole area is smaller than the longitudinal length L4 of the lower hole area.

3. The solder-free terminal according to claim 2, wherein: The upper hole area is composed of a first inner arc surface located in the pre-insertion area, inner inclined surfaces arranged on both sides of the first inner arc surface, and a first inner transition arc surface connected to the inner inclined surface; the lower hole area is composed of a second inner arc surface located in the strength area, a first inner arc surface arranged on both sides of the second inner arc surface, and a second inner transition arc surface connected to the first inner arc surface; the middle hole area is composed of two left-right symmetrical second inner arc surfaces, and the second inner arc surfaces are respectively connected to the first inner transition arc surface and the second inner transition arc surface.

4. The solder-free terminal according to claim 1, wherein: The outer surface of the plug-in portion includes a guiding inclined surface, a continuous curved surface, and a continuous transition surface. The guiding inclined surfaces are located on the front and rear sides of the top of the plug-in portion and are close to each other. The continuous curved surfaces are located on the left and right sides of the top of the plug-in portion and are close to each other. The upper ends thereof and the guiding inclined surfaces together constitute a square pre-insertion top surface. The lower ends of the continuous curved surfaces are connected to the limiting portion. The continuous transition surface is arranged between the front and rear side surfaces of the plug-in portion and the continuous curved surface. The upper end of the continuous transition surface is connected to the guiding inclined surface, and the lower end thereof is connected to the limiting portion.

5. The solder-free terminal according to claim 4, characterized in that: The continuous curved surface includes a first outer inclined surface, a second outer inclined surface, a first outer arc-shaped surface, and a first outer curved arc-shaped surface connected in sequence from top to bottom; the continuous transition surface includes a first outer transition surface, a second outer transition surface, a third outer transition surface, and a first outer curved transition surface connected in sequence from top to bottom; the first outer transition surface, the second outer transition surface, the third outer transition surface, and the first outer curved transition surface correspond to and are connected to the first outer inclined surface, the second outer inclined surface, the first outer arc-shaped surface, and the first outer curved arc-shaped surface, respectively; the lower ends of the first outer inclined surface and the first outer transition surface are commonly connected to a rhombus-shaped smooth transition surface; the lower ends of the rhombus-shaped smooth transition surface are connected to the second outer inclined surface and the second outer transition surface.

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