Connector terminal assembly for large current
By designing a spiral hollowed-out cylindrical conductor on the female terminal, surface-to-surface contact is achieved, solving the problems of high contact resistance and weak current carrying capacity of existing connector terminal assemblies during high-current charging, thus improving current carrying capacity and saving costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-03-20
AI Technical Summary
Existing connector terminal assemblies suffer from high contact resistance and weak current carrying capacity during high-current charging, failing to meet high-power charging requirements. Furthermore, existing improvement solutions increase costs or limit the shape design.
The design employs a female terminal, which includes a cylindrical conductor with continuous spiral grooves on its circumferential wall. The spiral grooves allow the cylindrical conductor to open up when the male terminal is inserted, forming a surface-to-surface contact, replacing the traditional line contact and reducing contact resistance.
Without increasing material usage or material composition, it significantly reduces contact resistance, increases current carrying capacity by 41%, extends service life to over 15,000 cycles, saves production costs, and reduces overall installation dimensions.
Smart Images
Figure CN224021099U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the structure manufacturing technical field of connector terminal, specifically relates to a connector terminal assembly for large current. BACKGROUND
[0002] The terminal connector assembly is widely used in the power supply line connection device of network energy equipment, base station, industrial power distribution equipment and new energy automobile, and the connector terminal assembly of new energy automobile charging connector device is taken as an example, the structure usually includes male terminal and female terminal, the male terminal is usually cylindrical conductor, is usually installed and fixed on the charging socket, and the female terminal adopts the elastic contact conductor formed with the insertion hole, is mainly arranged on the gun head of the charging gun, and the outside is wrapped and protected by the tubular insulating shell.
[0003] The female terminal structure of the connector terminal assembly of the traditional new energy charging connector device usually sets one to two convex elastic sheets in the main body to contact the male terminal, but since it is point contact, the contact resistance is large, with the continuous increase of charging power, the temperature rise is significant, causes the poor contact conduction performance, the current-carrying capacity is weak, and the large current charging cannot be met. For this reason, the female terminal in the industry generally adopts a split slot type structure, for example, the split slot type terminal structure is disclosed in the public numbers CN221632874U, CN 211017481U and CN217768849U, and the split slot type terminal structure is characterized by adopting a plurality of spring sheets arranged in a circle and enclosed into a cylindrical shape to realize elastic contact with the male terminal, changes the point contact into line contact, thereby further reducing the contact resistance and enhancing the current-carrying capacity of the terminal, so as to further meet the large current charging.
[0004] However, in practice, with the continuous increase of the charging power of new energy vehicles, the split slot type terminal structure still has the defects of large contact resistance and weak current-carrying capacity, cannot meet the requirements of large current charging, has the problem of low charging efficiency, and needs to be improved.
[0005] At present, the current-carrying capacity of the connector terminal assembly for large current in the industry is mainly realized by the following two ways:
[0006] 1. Replacing the material with higher conductivity.
[0007] However, under the condition of unchanged structure, replacing the material can indeed have an immediate effect, but at the same time, it will also increase the cost of the product.
[0008] 2. Reducing impedance by increasing the cross section of the conductor of the terminal.
[0009] Increasing the conductor cross-sectional size, increasing the contact pair, can reduce the impedance of the terminal assembly contact part to a certain extent, indirectly improve the current carrying capacity of the terminal, but this way will also increase the size, and the design of the other components of the charging connector device is limited and constrained, resulting in the overall appearance of the product also needs to be adjusted synchronously, so that the overall cost of the charging connector device increases, and the appearance of the product is also greatly discounted.
[0010] In summary, there is no more practical connector terminal assembly structure scheme in the industry that can achieve the purpose of improving the current carrying capacity without changing the material and increasing the material usage. SUMMARY
[0011] The utility model discloses a kind of connector terminal assemblies for large current, which can realize the improvement of connector current carrying capacity without changing material and increasing material usage.
[0012] The technical scheme of the utility model is as follows: a kind of connector terminal assembly for large current, including male terminal and the female terminal matched with it, the male terminal includes cylindrical conductor, and its characterized in that the female terminal includes the circular tubular conductor with continuous helical hollow groove on the circumference pipe, the inner diameter of the circular tubular conductor is less than the outer diameter of the cylindrical conductor, and the front end ring of the circular tubular conductor is provided with the cutout that is communicated or coincides with the front end of the helical hollow groove;When the cylindrical conductor is inserted into the circular tubular conductor, the circular tubular conductor is expanded under the action of the helical hollow groove to wrap the cylindrical conductor, so that the inner circumferential surface of the circular tubular conductor and the outer circumferential surface of the cylindrical conductor are tightly contacted to form face contact.
[0013] Further, the utility model discloses that the female terminal further includes the terminal lug fixed at the end of the circular tubular conductor.
[0014] Further, the utility model discloses that the wall surface of the front end ring of the circular tubular conductor is a flat surface perpendicular to its axis, and the cutout is a straight cutout parallel to the axis of the circular tubular conductor, which is communicated with the front end of the helical hollow groove.
[0015] Further, the utility model discloses that the circular tubular conductor is made by drilling a hole through the cylindrical conductor along the axis and then milling the helical hollow groove on the outer periphery, and the hole diameter is the inner diameter of the circular tubular conductor;Or the circular tubular conductor is made by spirally winding a metal spring around a mandrel along the axis at an equal interval of thread pitch, and the outer diameter of the mandrel is the inner diameter of the circular tubular conductor.
[0016] Further, the utility model discloses that the circular tubular conductor has a closed end, which can be integrally formed or sealed by welding a sealing plate or a sealing block.
[0017] Further, the terminal is a columnar member, or a tubular member, or a flat member, and the terminal is fixedly connected with the end of the round tubular conductor by riveting or electric welding or ultrasonic welding.
[0018] The working principle of the utility model is as follows:
[0019] Before the male terminal and the female terminal are matched and plugged, the inner diameter of the round tubular conductor of the female terminal is smaller than the outer diameter of the cylindrical conductor of the male terminal, and along with the insertion process of the cylindrical conductor of the male terminal, the section of the round tubular conductor first contacted with the cylindrical conductor is expanded under the action of the preset spiral hollow groove on the round tubular conductor, the inner diameter after expansion is equal to the outer diameter of the cylindrical conductor, forming the effect of wrapping the cylindrical conductor, and after the cylindrical conductor is inserted in place, the whole round tubular conductor is expanded, and the inner circumferential surface of the round tubular conductor is tightly attached to the outer circumferential surface of the cylindrical conductor to form surface contact. After the cylindrical conductor is pulled out, the inner circumferential wall curve of the round tubular conductor restores due to the absence of external force.
[0020] Regarding the contact resistance calculation of the male and female terminals, Home gives the reference formula as follows:
[0021] ,(μΩ);
[0022] In the formula, K is a material coefficient, F is a contact pressure, and m is a contact form coefficient;
[0023] For point contact, m=0.5;
[0024] For line contact, m=0.6-0.7;
[0025] For surface contact, m=1.
[0026] The contact pair design of the male and female terminals of the existing connector terminal assembly is line contact, and in the utility model scheme, it is surface contact, and under the condition that the material and pressure are unchanged, taking the common lateral pressure F=100N as an example, according to the above formula, it can be known that the contact resistance finally obtained in the scheme can be reduced by half. Further, according to the heat generation power P=I2R at the contact position, the heat generation power at the contact position of the connector terminal assembly in the scheme is 1 / 2 of the conventional design, that is, the current carrying capacity can be increased by 41 times.
[0027] Compared with the prior art, the utility model provides a kind of connector terminal assembly for large current, with the following beneficial effects:
[0028] 1、The utility model maximizes the conductive characteristics of material, which improves the structure of female terminal, changes the contact form of male and female terminals, changes line contact into surface contact, effectively reduces contact resistance, and further ensures that the current carrying capacity of the connector is improved without changing the material and increasing the amount of material.
[0029] 2. The female terminal inner peripheral surface and the male terminal outer peripheral surface are evenly stressed in the annular shape, the yield value is low, the service life is longer, the surface contact deformation value is small, the material is in the elastic deformation interval, the service life is improved to more than 15,000 times of plugging and unplugging, and the existing spring leaf type connector assembly can only meet less than 10,000 times.
[0030] 3. The contact part size of the female terminal (and the male terminal) in the utility model is stable, and the processing process is easier to control. The contact part of the female terminal of the conventional terminal assembly is formed by bending forming or mechanical processing extrusion, and after the external force of the male terminal is removed, the contact part will have a rebound phenomenon, and finally the final form and the design value will deviate to a certain extent. This interval is related to material batch, external force retention time, and degree of tool wear. The inner peripheral curved surface of the female terminal contact part in the utility model adopts overall contact of the inner peripheral curved surface of the circular pipe conductor, and the shape change after the opening and expansion of the male terminal and the contraction after the removal is small. The inner peripheral curved surface can be processed by mechanical drilling or spring winding, and the processing precision and stability of the inner diameter are higher.
[0031] 4. The material of the utility model is more saved, and the production cost can be saved.
[0032] At present, the inner periphery of the conventional split slot type structure female terminal needs to be bent or extruded to form an inner convex structure as the contact part of the male terminal. The radial height of the inner convex structure is the so-called bottom hole gap B. Therefore, the outer diameter D of the conventional split slot type structure female terminal is A+2B+2C, wherein A is the outer diameter of the paired male terminal, C is the wall thickness of the female terminal, and 2B is usually 0.2-1mm. In the female terminal structure of the utility model, the inner peripheral arc surface overall contact is adopted, and there is no bottom hole gap design. Therefore, the outer diameter d of the female terminal is a-2b+2c, wherein a is the outer diameter of the paired male terminal, c is the wall thickness, and 2b is the difference between the inner diameter after the opening of the circular pipe conductor and the inner diameter of the bottom hole, which is usually 0.2-0.5mm.
[0033] Therefore, under the premise that the outer diameter of the paired male terminal in the terminal assembly of the utility model and the conventional technology is the same (that is, A=a), and the wall thickness of the female terminal is equal (that is, C=c), D>d can be obtained, that is, the overall outer diameter of the female terminal of the utility model will be smaller than the conventional design, thereby realizing the saving of materials.
[0034] 5. The terminal assembly of the utility model has smaller installation size space requirement as a whole, and can be more flexibly applied in narrow scenes: the processed outer dimension is small, and when applied to a charging device product, more space can be provided for other components.
[0035] 6. The female terminal structure of the terminal assembly of the utility model is simple and convenient to process, compared with the current assembled terminal assembly, it is a single part, and can meet the higher current carrying demand without assembly.
[0036] The objects, advantages and features of the present application will be illustrated and explained by the following non-limiting description of preferred embodiments, given only as examples, with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS
[0037] Figure 1 is a schematic diagram of the overall three-dimensional structure of one embodiment of the present application (male and female terminals in unplugged state);
[0038] Figure 2 is Figure 1 is a side view of the change in state during plugging of the male and female terminals in the embodiment;
[0039] Figure 3 is a side view of the male and female terminals during plugging and matching in the prior connector terminal assembly;
[0040] Figure 4 is Figure 1 is a side view of the male and female terminals during plugging and matching in the embodiment;
[0041] Figure 5 is a schematic diagram of the overall three-dimensional structure of the second embodiment of the present application;
[0042] Figure 6 is a schematic diagram of the overall three-dimensional structure of the third embodiment of the present application.
[0043] In the figure: 1, male terminal; 101, cylindrical conductor; 2, female terminal; 201, pipe-shaped conductor; 201a, spiral hollow groove; 201b, front end ring; 201c, cutting groove; 202, terminal. DETAILED DESCRIPTION
[0044] The specific embodiments of the connector terminal assembly for large current provided by the present application will be described clearly and completely below with reference to the accompanying drawings. Obviously, the following described embodiments are only a part of the embodiments of the present application, not all the embodiments. Figures 1-6 Embodiment 1: First, the male and female terminals in the prior connector terminal assembly are described with reference to the accompanying drawings.
[0045] Figure 1 As shown in the embodiment, the connector terminal assembly for large current provided in the embodiment has a male terminal 1 and a female terminal 2 matched with the male terminal 1, the male terminal 1 comprises a cylindrical conductor 101, and the core improvement of the utility model lies in that the female terminal 2 is jointly constituted by a circular tubular conductor 201 and a terminal lug 202 fixed at the end of the circular tubular conductor 201. A continuous spiral hollow groove 201a is arranged on the circumference of the circular tubular conductor 201, and the inner diameter of the circular tubular conductor 201 is smaller than the outer diameter of the cylindrical conductor 101. A cutting groove 201c is formed in the front end ring 201b of the circular tubular conductor 201 and is communicated with the front end of the spiral hollow groove 201a.
[0046] Specifically as Figure 1 As shown in the embodiment, the wall surface of the front end ring 201b of the circular tubular conductor 201 is a flat surface perpendicular to the axis of the circular tubular conductor 201, and the cutting groove 201c is a straight cutting groove parallel to the axis of the circular tubular conductor 201 and communicated with the front end of the spiral hollow groove 201a.
[0047] The circular tubular conductor 201 has a closed end in the embodiment.
[0048] The circular tubular conductor 201 is made by drilling a hole (blind hole) through the axis of the cylindrical conductor and then milling the spiral hollow groove 201a on the outer periphery, and the hole diameter of the hole (blind hole) is the inner diameter of the circular tubular conductor 201.
[0049] Still in combination Figure 1 As shown in the embodiment, the terminal lug 202 is a tubular member and is fixed on the closed end of the circular tubular conductor 201 by electric welding.
[0050] In combination Figure 2 As shown in the embodiment, when the cylindrical conductor 101 is inserted into the circular tubular conductor 201, the circular tubular conductor 201 is expanded under the action of the spiral hollow groove 201a to wrap the cylindrical conductor 101, so that the inner periphery of the circular tubular conductor 201 is tightly attached to the outer periphery of the cylindrical conductor 101 to form a surface-to-surface contact.
[0051] Regarding the calculation of the contact resistance of the male terminal 1 and the female terminal 2, HOM gives a reference formula as follows:
[0052] , (μΩ);
[0053] In the formula, K is a material coefficient, F is a contact pressure, and m is a contact form coefficient.
[0054] For point contact, m=0.5;
[0055] For line contact, m=0.6-0.7;
[0056] For surface contact, m=1.
[0057] Existing connector terminal assemblies use line contact for both male and female terminals, while this invention uses surface contact. With materials and pressure remaining constant, taking a common lateral pressure of F=100N as an example, the contact resistance obtained by this solution can be reduced by half according to the above formula. Furthermore, based on the heat generation power at the contact point P=I²R, the heat generation power at the contact point of the connector terminal assembly in this solution is half that of the conventional design, meaning the current carrying capacity can be increased by 41%.
[0058] Therefore, it can be said that the connector terminal assembly of this utility model maximizes the conductivity of the material. By improving the structure of the female terminal 2, the contact form between the male terminal 1 and the female terminal 2 is changed from line contact to surface contact, which effectively reduces the contact resistance and thus ensures that the current carrying capacity of the connector is improved without changing the material or increasing the amount of material used.
[0059] Furthermore, in this invention, the inner circumferential surface of the female terminal 2 and the outer circumferential surface of the male terminal 1 are subjected to uniform annular force, resulting in a low yield and a longer service life. The surface contact deformation is small, and the material is within the elastic deformation range, increasing the service life to more than 15,000 insertion and removal cycles. Existing spring-type connector terminal assemblies can only meet less than 10,000 cycles.
[0060] Furthermore, the connector terminal assembly of this utility model uses less material, mainly in the female terminal 2, which we will discuss below. Figure 3 and Figure 4 The diagram illustrates the structural and dimensional differences between this invention and conventional technology, thereby explaining the differences in material usage.
[0061] like Figure 3 As shown, for ease of explanation, we use the same labeling for the male and female terminals as in this case (i.e., male terminal is 1, female terminal is 2). Currently, the conventional slotted female terminal 2 requires bending or extrusion to form an inner convex structure as the contact part with the male terminal 1. The radial height of this inner convex structure is the so-called bottom hole gap B. Therefore, the outer diameter D of the conventional slotted female terminal 2 is D = A + 2B + 2C, where A is the outer diameter of the mating male terminal 1, C is the wall thickness of the female terminal 2, and 2B is usually 0.2-1mm.
[0062] And combined Figure 4 As shown, in the structure of the female terminal 2 of this utility model, since the inner circumferential arc surface is used for integral contact and there is no bottom hole gap design, the outer diameter of the female terminal 2 is d=a-2b+2c, where a is the outer diameter of the paired male terminal 1, c is the wall thickness, and 2b is the difference between the inner diameter of the inner circumference of the cylindrical conductor 201 after it is spread out and the inner diameter of the bottom hole (i.e. the tube hole of the cylindrical conductor 201 when it is not spread out), which is usually 0.2-0.5mm.
[0063] Thus, by comparison, when the case and the terminal assembly of the conventional technology are matched with the outer diameter of the male terminal 1 (i.e. A=a), and the wall thickness of the female terminal 2 is equal (i.e. C=c), it can be obtained that D>d, that is, the outer diameter of the female terminal 2 of the case is generally smaller than that of the conventional design, thereby realizing the saving of materials.
[0064] Embodiment 2: as shown in the figure, another embodiment of the connector terminal assembly for large current of the utility model, same as embodiment 1 has male terminal 1 and female terminal 2 matched with it, male terminal 1 includes cylindrical conductor 101, and female terminal 2 is jointly constituted by circular tubular conductor 201 and terminal lug 202 fixed at the end thereof. Figure 5 The structure of the circular tubular conductor 201 is completely same as that of embodiment 1, and the specific description can be referred to the description of embodiment 1, and different from embodiment 1 is that the terminal lug 202 in the embodiment is a flat member, and is connected with the end of the circular tubular conductor 201 through ultrasonic welding. Of course, the working principle and implementation effect of the embodiment can be referred to the description of embodiment 1.
[0065] Embodiment 3: as shown in the figure, another embodiment of the connector terminal assembly for large current of the utility model, same as embodiment 1 has male terminal 1 and female terminal 2 matched with it, male terminal 1 includes cylindrical conductor 101, and female terminal 2 is jointly constituted by circular tubular conductor 201 and terminal lug 202 fixed at the end thereof. Figure 6 The female terminal 2 in the embodiment is jointly constituted by circular tubular conductor 201 and terminal lug 202 fixed at the end thereof. The circular tubular conductor 201 is provided with continuous spiral hollow grooves 201a on the circumference thereof, and the inner diameter of the circular tubular conductor 201 is smaller than the outer diameter of the cylindrical conductor 101. The front end ring 201b of the circular tubular conductor 201 is provided with a cut groove 201c in the embodiment, and the cut groove 201c is completely coincided with the front end of the spiral hollow groove 201a, that is, the starting notch of the front end of the spiral hollow groove 201a is arranged on the front end ring 201b of the circular tubular conductor 201, so that it does not have the flat cut groove as in embodiment 1.
[0066] In actual implementation, the circular tubular conductor 201 in the embodiment is spirally wound at equal interval screw thread pitch along the core rod axis, and the outer diameter of the core rod is the inner diameter of the circular tubular conductor 201. Therefore, compared with embodiment 1, the wall surface of the front end ring 201b of the circular tubular conductor 201 in the embodiment is not a flat surface.
[0067] Still in combination with
[0068] Figure 6 As shown, the circular tube-shaped conductor 201 in this embodiment also has a closed end, and the terminal 202 is a tubular member riveted to the closed end of the circular tube-shaped conductor 201.
[0069] The working principle and implementation effects of this embodiment can also be referred to the description of embodiment 1.
[0070] Of course, the above is only a specific application example of the present application, and does not constitute any limitation on the protection scope of the present application. In addition to the above embodiments, the present application can also have other implementation manners. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of the present application.
Claims
1. A connector terminal assembly for high current, comprising a male terminal (1) and a mating female terminal (2), the male terminal (1) comprising a cylindrical conductor (101), characterized in that... The female terminal (2) includes a cylindrical conductor (201) with a continuous spiral groove (201a) on its circumferential wall. The inner diameter of the cylindrical conductor (201) is smaller than the outer diameter of the cylindrical conductor (101). The front end ring wall (201b) of the cylindrical conductor (201) has a cut (201c) that communicates with or overlaps with the front end of the spiral groove (201a). When the cylindrical conductor (101) is inserted into the cylindrical conductor (201), the cylindrical conductor (201) is expanded by the spiral groove (201a) to wrap the cylindrical conductor (101), so that the inner circumferential surface of the cylindrical conductor (201) and the outer circumferential surface of the cylindrical conductor (101) are in close contact to form a surface-to-surface contact.
2. A connector terminal assembly for high current according to claim 1, characterized in that... The female terminal (2) also includes a connector (202) fixed to the end of the cylindrical conductor (201).
3. A connector terminal assembly for high current according to claim 1, characterized in that... The wall surface of the annular wall (201b) at the front end of the cylindrical conductor (201) is a straight surface perpendicular to its axis, while the groove (201c) is a straight groove parallel to the axis of the cylindrical conductor (201), which is connected to the front end of the spiral hollow groove (201a).
4. A connector terminal assembly for high current according to claim 1, characterized in that... The cylindrical conductor (201) is made by drilling a hole along the axis of a cylindrical conductor and then milling the spiral groove (201a) on the outer circumference. The diameter of the hole is the inner diameter of the cylindrical conductor (201); or the cylindrical conductor (201) is made by spirally winding a metal spring along the axial direction of a core rod with equally spaced thread pitches. The outer diameter of the core rod is the inner diameter of the cylindrical conductor (201).
5. A connector terminal assembly for high current according to claim 1 or 2, characterized in that... The cylindrical conductor (201) has a closed end.
6. A connector terminal assembly for high current according to claim 2, characterized in that... The connector (202) is a columnar member, a tubular member, or a flat member, and the connector (202) is fixedly connected to the end of the cylindrical conductor (201) by riveting, electric welding, or ultrasonic welding.