A high-power terminal spring

Abstract

The utility model discloses a high -power terminal spring leaf, including the left and right edge of cross section is annular opening shape, and the left and right edge is connected through the spring leaf of even interval setting between, and the spring leaf cross section is W type and includes connecting portion, bending portion and intermediate portion, and connecting portion is connected with intermediate portion through bending portion, and two connecting portions are connected with right edge and left edge respectively, and the both sides end surface of intermediate portion is V -shaped setting. The utility model discloses the spring leaf cross section design is W type, including connecting portion, bending portion and intermediate portion, and the both sides end surface of intermediate portion is V -shaped setting, and connecting portion and bending portion are through arc transition between, and the intermediate portion of spring leaf is horizontal, need not torsion procedure, can direct stamping forming, and the cost is lower, and arc transition makes the spring leaf and the inside contact of terminal produce enough big positive force, guarantees that the contact resistance is in lower interval, effectively control temperature rise, simultaneously, adopt the copper alloy of high conductivity, reduce the volume resistance and temperature rise of spring leaf.

Description

Technical Field

[0001] This utility model relates to the field of high-current connector technology, and more specifically, to a high-power terminal spring. Background Technology

[0002] In the national standard DC charging system for new energy vehicles, the DC+ and DC- terminals inside the DC charging socket are the core components for realizing high-power power transmission, and their performance directly determines the charging efficiency, safety, and service life. Currently, the mainstream structures of these high-power terminals are mainly divided into spring-loaded structures and slotted structures. Among them, the spring-loaded structure has a higher proportion in practical applications due to its superior contact stability and insertion / removal adaptability.

[0003] Existing spring-type terminals typically use C17200 beryllium copper for their spring bodies, requiring a heat treatment process to enhance the material's yield strength. This type of beryllium copper spring offers significant performance advantages: firstly, heat-treated C17200 beryllium copper possesses excellent elastic recovery and fatigue resistance, maintaining stable contact pressure during long-term insertion / removal cycles (especially in high-frequency abuse scenarios), effectively ensuring the terminal's lifespan; secondly, its strong structural adaptability meets the stringent reliability requirements of new energy vehicle charging, thus making it the mainstream choice for high-power charging terminals.

[0004] However, as the new energy vehicle industry continues to demand higher standards for cost control, charging efficiency, and mass production stability, existing C17200 beryllium copper springs are gradually revealing insurmountable technical defects and application limitations, specifically in the following three aspects:

[0005] First, the production technology of C17200 beryllium copper material has high barriers to entry, and the industry relies heavily on imports for the materials needed. This not only leads to a supply cycle of several weeks or even months, which seriously affects the mass production progress of terminals and charging socket assemblies, but also the procurement cost of imported beryllium copper material is significantly higher than that of ordinary copper alloys. Its price is usually more than double that of conventional copper alloys, which directly increases the manufacturing cost of terminals and thus increases the overall cost of new energy vehicle charging systems.

[0006] Secondly, C17200 beryllium copper has a conductivity (in IACS%) of only about 23%, indicating relatively poor conductivity. In high-power charging scenarios for new energy vehicles, when the charging current exceeds 250A, the Joule heat generated by the current transmission in the beryllium copper spring increases significantly, causing the terminal temperature rise to exceed the safety threshold of 50K. To address the temperature rise issue, existing technologies typically require thickening the diameter of the connecting cable to reduce cable resistance and dissipate heat. However, this further increases the material cost and weight of the charging socket wiring harness assembly. Additionally, thicker cables may lead to limited assembly space, affecting the flexibility of the overall socket structural design.

[0007] Finally, in addition to material and cable costs, the existing beryllium copper spring processing requires an additional heat treatment step, which not only extends the production cycle but also increases the investment in heat treatment equipment and energy consumption costs. Furthermore, during terminal assembly, the high elasticity parameter control requirements of beryllium copper springs and the increased assembly precision requirements indirectly increase assembly time and defect rate, further pushing up the overall cost of using the terminals.

[0008] In summary, the C17200 beryllium copper springs used in the DC+ and DC- high-power terminals of the current national standard DC charging sockets for new energy vehicles have significant shortcomings in terms of material supply, cost control, and temperature rise control, making it difficult to meet the development needs of the new energy vehicle industry for charging systems that are "low-cost, highly reliable, and highly adaptable".

[0009] Therefore, developing a new type of spring that can directly replace existing beryllium copper springs, is suitable for high-power charging scenarios, and has significant advantages in material cost, assembly cost, and temperature rise control has become an urgent technical problem to be solved in this field. Utility Model Content

[0010] This invention provides a high-power terminal spring that reduces the volume resistivity and temperature rise of the spring by using a copper alloy with high conductivity. Combined with a W-shaped spring design, it can solve the technical problems of high cost and difficult temperature rise control of existing springs.

[0011] According to one aspect of the present invention, a high-power terminal spring is provided, comprising a left and right perimeter with an annular opening cross-section. The left and right perimeters are connected by springs evenly spaced apart. The springs have a W-shaped cross-section and include a connecting portion, a bent portion, and a middle portion. The connecting portion is connected to the middle portion through the bent portion, and the two connecting portions are respectively connected to the right and left perimeters. The two end faces of the middle portion are V-shaped. The connecting portion and the bent portion are connected by an arc transition, and the outer edges of the left and right perimeters are provided with protrusions.

[0012] Based on the above scheme, preferably, the ends of the left and right edges are bent outward to form flanges, and the convex bulges are provided on the end face of the flanges, and the convex bulges are multiple evenly spaced.

[0013] Based on the above scheme, the preferred option is that there are 28 reeds.

[0014] Based on the above scheme, the preferred embodiment is that the thickness of the spring is 0.2 mm and the length is 18 mm.

[0015] Based on the above scheme, the preferred option is that the convex bulge on the left side is evenly spaced in six intervals.

[0016] Based on the above scheme, the preferred option is that the convex bulge on the right side is evenly spaced with 40 intervals.

[0017] Based on the above scheme, the preferred option is that the reed is a copper alloy sheet.

[0018] Preferably, based on the above scheme, the inner diameter of the ring formed by the middle part of the spring is smaller than the inner diameter of the ring formed by the connecting part.

[0019] This utility model discloses a high-power terminal spring with a W-shaped cross-section, including a connecting part, a bent part, and a middle part. The connecting part is connected to the middle part through the bent part, and the two connecting parts are connected to the right and left edges respectively. The two end faces of the middle part are V-shaped. The connecting part and the bent part are connected by an arc-shaped transition. The middle part of the spring is horizontal, eliminating the need for a twisting process and allowing for direct stamping, thus reducing costs. The arc-shaped transition ensures that the spring generates a sufficiently large positive force when in contact with the inside of the terminal, keeping the contact resistance in a low range and effectively controlling the temperature rise. At the same time, the use of a high-conductivity copper alloy reduces the volume resistivity and temperature rise of the spring, making it suitable for use in high-power charging terminals. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of a high-power terminal spring according to the present invention;

[0022] Figure 2 This is a perspective view of the high-power terminal spring and terminal of this utility model after being combined;

[0023] Figure 3 For the present utility model Figure 2 Cross-sectional view;

[0024] Figure 4 For the present utility model Figure 2 Cross-sectional view.

[0025] Explanation of icon numbers:

[0026] 1. Left edge; 2. Right edge; 3. Spring; 31. Connecting part; 32. Bending part; 33. Middle part; 4. Protrusion; 5. Terminal; 51. Groove; 52. Left retaining wall; 53. Right retaining wall; Detailed Implementation

[0027] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0028] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of a descriptive feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or sets.

[0029] To keep the drawings concise, only the parts relevant to this utility model are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for the sake of simplicity and ease of understanding, in some figures, only one of the components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0030] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0031] In the embodiments shown in the accompanying drawings, directional indications (such as up, down, left, right, front, and back) are used to explain the structure and movement of the various components of this invention. These indications are relative, not absolute. These descriptions are appropriate when the components are in the positions shown in the drawings. If the positions of these components change, the directional indications also change accordingly.

[0032] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0034] Please see Figure 1 and combined Figure 2 , Figure 3 and Figure 4As shown, this utility model provides a high-power terminal spring, including a left circumference 1 and a right circumference 2 with an annular opening cross-section. The left circumference 1 and the right circumference 2 are connected by 28 springs 3 evenly spaced. The thickness of the spring 3 is 0.2mm, the total length of the spring 3 is designed to be 18mm, and it is made of high-conductivity copper alloy strip by stamping and rolling. The part is very lightweight, the material cost is more than half that of ordinary springs, and it does not require heat treatment. After stamping, it can be directly electroplated into a finished product.

[0035] The spring 3 has a W-shaped cross-section, including a connecting portion 31, a bent portion 32, and a middle portion 33. The connecting portion 31 is connected to the middle portion 33 via the bent portion 32, and the two connecting portions 31 are respectively connected to the right perimeter 2 and the left perimeter 1. The two end faces of the middle portion 33 are V-shaped, and the connecting portion 31 and the bent portion 32 are connected by an arc-shaped transition to enhance the positive contact force. The inner diameter of the ring formed by the middle portion 33 is smaller than the inner diameter of the ring formed by the connecting portion 31, further optimizing the contact performance.

[0036] It should be noted that the terminal used to install this utility model includes a base, which is annular and has a groove 51 on its inner edge. A left retaining wall 52 is provided on the left side of the groove 51, and a right retaining wall 53 is provided on the right side of the groove 51. The high-power terminal spring of this utility model is installed in the groove 51 of the terminal and the left retaining wall 52 limits the left retaining edge 1, and the right retaining wall 53 limits the right retaining edge 2.

[0037] Specifically, when the male pin is inserted into the terminal, the two curved transition surfaces on the inner side of the spring 3 contact the outer surface of the pin, generating positive contact pressure. Under pressure, the inner wall of the outer terminal expands, and the two curved R-angle surfaces on the outer side of the spring 3 contact the inner wall of the terminal, simultaneously generating positive pressure. When a large current passes through the terminal 5, the current is transferred from the pin to the spring 3, and then from the spring 3 to the inner wall of the terminal 5.

[0038] The W-shaped design of the spring 3 ensures that a sufficiently large positive force is generated when the spring 3 contacts the pin and the inner wall of the terminal 5, thereby ensuring that the contact resistance is in a lower range.

[0039] In addition, the W-shaped spring 3 has good elasticity and is not prone to yielding or deformation during repeated insertion and removal of the pin, ensuring that it can still provide sufficient positive contact pressure after 10,000 insertions and removals.

[0040] Furthermore, the ends of the left and right circumference edges 1 and 2 of this invention are bent outward to form flanges, which serve as guides during the insertion of the pin, preventing the pin from contacting the end face of the spring 3. The end faces of the flanges are provided with protrusions 4. Six protrusions 4 are evenly spaced on the left circumference edge 1, and their function is to fix the spring 3 inside the terminal 5. After the spring 3 is installed inside the terminal 5, the two end faces of the protrusions 4 contact the two end faces of the groove 51 of the terminal 5, thereby limiting the left and right movement of the terminal 5. In addition, the left and right retaining rings 52 and 53 of the terminal 5 contact the left and right end faces of the spring 3, respectively, which also serve to fix the spring 3.

[0041] The protrusions 4 on the right side 2 are evenly spaced at 40 intervals. When the pin is inserted into the terminal 5, the protrusions 4 are pressed against the inner wall of the terminal 5, which can generate a sufficiently large contact pressure, thereby effectively reducing the contact resistance and enhancing the fixing stability between the spring 3 and the terminal 5.

[0042] The spring 3 of this utility model is formed by stamping, without the need for twisting and heat treatment processes, making it simple to process and low in cost. It also has excellent conductivity and temperature rise control capabilities, making it suitable for high-power charging terminals 5 of new energy vehicles.

[0043] Compared with the prior art, the high-power terminal spring 3 of this utility model, by using a copper alloy material with high conductivity and combining it with a W-shaped spring 3 structure, has the following advantages:

[0044] First, by using copper alloy instead of expensive C17200 beryllium copper, the material cost is significantly reduced. Compared with the existing steel cap structure of terminal 5, the volume resistivity of the spring is reduced and the temperature rise is reduced. It can be used on high-power charging terminal 5, and no heat treatment process is required, which simplifies the processing flow and shortens the production cycle.

[0045] Secondly, the W-shaped spring 3 structure has a horizontal middle section, which eliminates the need for a twisting process and allows for direct stamping, reducing processing difficulty and cost. The arc transition design enhances the positive contact force between the spring 3 and the inside of the terminal 5, ensuring that the contact resistance is in a low range.

[0046] Third, the convex bulge 4 design enhances the fixing stability of the spring 3 and the terminal 5, improves assembly efficiency and reduces the defect rate.

[0047] Fourth, when the spring 3 of this utility model contacts the terminal, the inner surface of the contact spring contacts the outer surface of the male pin, which is a surface-to-surface contact. In contrast, the spring with the torsion structure contacts the outer surface of the male pin through the intersection line of the side and inner surface of the contact spring, which is a line-to-surface contact. This type of surface-to-surface contact spring is less prone to wear, has a longer service life, and has lower contact resistance.

[0048] Fifth, the spring 3 of this utility model is made of copper alloy strip with a thickness of 0.2mm, which makes it more elastic and less prone to yielding and loss of insertion and extraction force even under oblique insertion conditions, thus ensuring reliability throughout the overall life cycle.

[0049] Sixth, the spring 3 of this utility model is designed with multiple contact points with the inner wall of the terminal base. For example, the left and right protrusions 4, the surrounding edge, and the spring sheet all have contact with the inside of the terminal after the male pin is inserted. There are multiple current transmission paths, and the temperature rise can be greatly reduced.

[0050] Seventh, since the spring 3 of this utility model is not fixed by a steel cap, when it is damaged, it can be directly removed from the outside of the socket, and a new spring can be inserted to continue to use it, thereby greatly reducing after-sales costs and maintenance difficulties.

[0051] In summary, this utility model provides a spring 3 product that is low in cost, has excellent temperature rise control, stable structure, and is suitable for high-power charging terminals, effectively solving the problems of high material cost, difficult temperature rise control, and complex processing in the prior art.

[0052] Finally, the method described in this application is merely a preferred embodiment and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A high-power terminal spring, characterized in that, It includes a left and right circumference with an annular opening in cross-section. The left and right circumferences are connected by springs that are evenly spaced apart. The springs have a W-shaped cross-section and include a connecting part, a bent part, and a middle part. The connecting part is connected to the middle part through the bent part, and the two connecting parts are respectively connected to the right and left circumferences. The two end faces of the middle part are V-shaped. The connecting part and the bent part are connected by an arc transition, and the outer edges of the left and right circumferences are provided with protrusions.

2. A high-power terminal spring as described in claim 1, characterized in that, The ends of the left and right edges are bent outward to form flanges, and the convex bulges are provided on the end faces of the flanges, and the convex bulges are arranged in multiple evenly spaced intervals.

3. A high-power terminal spring as described in claim 1, characterized in that, There are 28 reeds.

4. A high-power terminal spring as described in claim 1, characterized in that, The spring has a thickness of 0.2 mm and a length of 18 mm.

5. A high-power terminal spring as described in claim 1, characterized in that, The convex bulges on the left side are arranged in six evenly spaced intervals.

6. A high-power terminal spring as described in claim 1, characterized in that, The convex bulges on the right side are evenly spaced at 40 intervals.

7. A high-power terminal spring as described in claim 1, characterized in that, The reed is a copper alloy sheet.

8. A high-power terminal spring as described in claim 1, characterized in that, The inner diameter of the ring formed by the middle part of the spring is smaller than the inner diameter of the ring formed by the connecting part.

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