Double-layer terminal

Abstract

The invention discloses a double-layer terminal which comprises an inner current-carrying terminal and an outer current-carrying terminal arranged outside at least part of the inner current-carrying terminal in a sleeving mode, the inner current-carrying terminal is provided with a plugging section, and a plugging cavity used for being plugged and electrically connected with a matching terminal is formed in the plugging section. The outer current-carrying terminal is at least sleeved on the periphery of the plugging section, the plugging section is provided with a radial through hole, the outer current-carrying terminal is provided with an outer elastic sheet, and at least part of the outer elastic sheet passes through the through hole to be electrically connected with the matching terminal. According to the invention, the outer current-carrying terminal is sleeved outside the inner current-carrying terminal, the inserted matching terminal is firstly contacted with the insertion cavity of the inner current-carrying terminal, and the matching terminal is continuously inserted to be contacted with the outer elastic sheet of the outer current-carrying terminal, so that the contact area between the matching terminal and the double-layer terminal is increased, the contact resistance is reduced, and the current-carrying capacity is also doubled; and the requirement of high current-carrying capacity of the power terminal is met.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and more specifically, to a double-layer terminal. Background Art

[0002] With the rapid development of new energy electric vehicles, the use of terminals for electrical connection is increasing. The terminals used in charging guns and charging stations are mainly used to transmit electrical signals or conduct electricity. The terminals need to be plugged into the matching terminals to achieve electrical connection. In existing new energy vehicle charging stations, high-current terminals are generally made of copper materials by turning and forming, which can ensure the current conduction cross-sectional area and the contact retention force when the terminals are plugged in. However, the turning process has high cost and long working hours, and it is impossible to reduce the terminal cost.

[0003] Traditional stamped terminals have low processing costs and short working hours, but they have a small current-conducting cross-sectional area, low current carrying capacity, and cannot meet the requirements for contact retention during insertion. Moreover, within the limited national standard charging seat interface size, the traditional stamped terminal structure is also difficult to meet the current carrying requirements, and there is a problem of low current carrying capacity in a limited space.

[0004] Therefore, a new solution is urgently needed in the prior art to solve the above problems. Summary of the invention

[0005] One purpose of the present invention is to provide a new technical solution for double-layer terminals to solve the problems of high processing cost, long working hours and inability to reduce costs for high current terminals, as well as the problems of low current carrying capacity, small current conducting cross-sectional area and inability to meet the requirements of contact retention force during insertion of traditional stamped terminals in a limited space.

[0006] According to the present invention, a double-layer terminal is provided for plugging with a mating terminal, comprising an inner current-carrying terminal and an outer current-carrying terminal sleeved outside at least a portion of the inner current-carrying terminal.

[0007] The inner current-carrying terminal has an insertion section, in which an insertion cavity is provided for plugging in and electrically connecting with the mating terminal. The outer current-carrying terminal is at least sleeved on the outer periphery of the insertion section, and the insertion section is provided with a radial through hole. The outer current-carrying terminal has an outer spring sheet, and the outer spring sheet at least partially passes through the through hole to be electrically connected with the mating terminal.

[0008] Optionally, part of the plug-in section is divided into multiple inner spring sheets by multiple axially extending expansion and contraction gaps, the expansion and contraction gaps pass through the through hole, and the outer spring sheet is provided with an elastic arm, the outer spring sheet partially abuts the inner spring sheet, and the free end of the elastic arm extends into the through hole.

[0009] Optionally, the through holes are symmetrically arranged along the midline of the expansion and contraction seam.

[0010] Optionally, after the mating terminal is plugged into the plug-in cavity, the outer peripheral surface of the mating terminal abuts and is electrically connected to the minimum inner diameter surrounded by the multiple elastic arms, and abuts and is electrically connected to part of the inner walls of the multiple inner spring sheets.

[0011] Optionally, a plurality of the inner elastic sheets are evenly arranged along the circumference of the plug-in section, and the inner diameter of the plug-in cavity gradually decreases along the direction from the extending starting end of the inner elastic sheet to the free end of the inner elastic sheet.

[0012] Optionally, the free ends of the plurality of inner spring sheets are bent outwardly away from the axis of the plug-in section to form an inner guide portion, and the free ends of the plurality of outer spring sheets are bent outwardly toward the axis of the plug-in section to form an outer guide portion matching the inner guide portion.

[0013] Optionally, the number of the outer elastic sheets and the number of the expansion and contraction joints are the same.

[0014] Optionally, a plurality of the outer spring sheets are evenly spaced and arranged along the circumference of the outer current-carrying terminal, and each of the outer spring sheets is symmetrically pressed outside two adjacent inner spring sheets along the center line of the expansion and contraction seam.

[0015] Optionally, the plurality of elastic arms are provided with contact portions bent toward the axis direction of the plug-in section, and the outer peripheral surface of the mating terminal abuts against and is electrically connected to the minimum inner diameter surrounded by the plurality of contact portions.

[0016] Optionally, a plating layer is provided at least on a region where the outer circumference of the inner current-carrying terminal and the inner circumference of the outer current-carrying terminal contact each other.

[0017] Optionally, the inner current-carrying terminal has a fixed section connected to the plug-in section, and the outer current-carrying terminal has an outer fixed portion connected to the plurality of outer spring sheets, and after the outer current-carrying terminal is sleeved outside the inner current-carrying terminal, the outer fixed portion covers the entire fixed section.

[0018] Optionally, one of the fixing section and the outer fixing portion is provided with a rivet hole, and the other is provided with a rivet wing, and the rivet wing is snap-fitted or riveted to the rivet hole to fix the outer current-carrying terminal and the inner current-carrying terminal to each other.

[0019] Optionally, an integrated sealing structure is injection-molded on part of the interior of the fixing section and part of the outer wall of the outer fixing portion, and the sealing structure intrudes from outside the outer fixing portion into the interior of the fixing section and seals the interior of the fixing section.

[0020] Optionally, at least one circumferential sealing groove is provided along the outer wall of the sealing structure for mounting a sealing ring.

[0021] Optionally, a clamping groove spaced apart from the sealing groove is further provided on the outer wall of the sealing structure for clamping with a fixed position.

[0022] Optionally, the cross-sectional shapes of the outer fixing portion and the fixing section at the position where the sealing structure is arranged are both arc-shaped and / or porous ring-shaped.

[0023] Optionally, the inner current-carrying terminal has a first connection portion connected to the fixed section, and the outer current-carrying terminal has a second connection portion connected to the outer fixed portion, and the first connection portion and the second connection portion are at least partially relatively fitted and connected, and are used to connect the same conductor.

[0024] Optionally, a first arc-shaped transition portion is provided between the fixing section and the first connecting portion, a second arc-shaped transition portion is provided between the outer fixing portion and the second connecting portion, and the first arc-shaped transition portion and the second arc-shaped transition portion are arranged opposite to each other.

[0025] Optionally, it also includes a protective shell sleeved outside the external current-carrying terminal, the outer wall of the protective shell is provided with a plurality of clamping arms arranged at intervals, and at least part of the clamping arms are pressed outside the outer spring sheet to strengthen the clamping of the elastic arm and the inner spring sheet on the mating terminal.

[0026] Optionally, the protective shell is made of steel or stainless steel, and the inner current-carrying terminal and the outer current-carrying terminal are made of copper or copper alloy.

[0027] The beneficial effects of the present invention are:

[0028] 1. Traditional high-current terminals are generally made of copper materials by turning, which can ensure the current conducting cross-sectional area and the contact retention force of the terminals when plugged in. However, the turning process has high processing costs and long working hours, which cannot reduce the terminal cost. Although the traditional stamping terminals have low processing costs and short working hours, they have small current conducting cross-sectional area, small current carrying capacity, and the contact retention force when plugged in cannot meet the requirements. Moreover, within the limited national standard charging seat interface size, the traditional stamping terminal structure is also difficult to meet the current carrying requirements, and there is a problem of low current carrying capacity in a limited space.

[0029] The inner current-carrying terminal and the outer current-carrying terminal of the present invention are both integrally formed by stamping and curling the plate, and the terminals are made using a stamping process, with low processing cost and short working hours. After the mating terminal is inserted into the inner current-carrying terminal, it first contacts the plug-in cavity, and then contacts the outer spring sheet of the outer current-carrying terminal. Both the inner current-carrying terminal and the outer current-carrying terminal are in contact with the mating terminal, which increases the current conduction cross-sectional area of ​​the mating terminal and the double-layer terminal, reduces the contact resistance, and increases the terminal current carrying capacity exponentially. After the inner current-carrying terminal is sleeved with the outer current-carrying terminal, the overall occupied space changes very little, and the high current carrying capacity requirements of the power terminal can be met within the limited national standard charging seat interface size. Moreover, after the outer current-carrying terminal is sleeved outside the inner current-carrying terminal, the outer spring sheet can also increase the clamping force of the plug-in cavity of the inner current-carrying terminal on the mating terminal, and the contact retention force meets the requirements during insertion.

[0030] 2. The double-layer terminal formed by the outer current-carrying terminal made of copper or copper alloy and the inner current-carrying terminal made of copper or copper alloy has poor fatigue resistance. Due to repeated plugging and unplugging, the elasticity of the plug-in end of the inner current-carrying terminal and the outer spring of the outer current-carrying terminal will decrease, resulting in the enlargement of the plug-in cavity of the plug-in section, insufficient clamping force on the mating terminals, increasing contact resistance, and aggravated temperature rise, resulting in the risk of power use.

[0031] The double-layer terminal of the present invention is outer-mounted with a protective shell made of steel or stainless steel. The protective shell made of steel or stainless steel has good fatigue resistance, strengthens the double-layer terminal and increases the clamping force of the mating terminal. The double-layer terminal and the mating terminal are not easily deformed during repeated plugging and unplugging, increases the number of plugging and unplugging times, and improves the service life of the double-layer terminal.

[0032] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0034] Figure 1 It is a structural schematic diagram of a double-layer terminal of the present invention;

[0035] Figure 2 It is a schematic diagram of the structure of the current-carrying terminal in the present invention;

[0036] Figure 3 It is a structural schematic diagram of the external current-carrying terminal of the present invention;

[0037] Figure 4 It is a structural schematic diagram of a double-layer terminal with a sealing structure of the present invention;

[0038] Figure 5 It is a structural schematic diagram of a double-layer terminal with a protective shell according to the present invention;

[0039] Figure 6 It is a schematic cross-sectional structure diagram of a double-layer terminal of the present invention;

[0040] Figure 7 A schematic diagram of a local structure in which the cross-sectional shapes of the locations where the sealing structures are arranged on the outer fixing portion and the fixing section of the present invention are both arc-shaped and / or porous annular.

[0041] The following are marked in the figure:

[0042] 10. Inner current-carrying terminal; 11. Plug-in section; 111. Inner spring sheet; 112. Through hole; 113. Inner guide portion; 12. Expansion and contraction joint; 13. Fixing section; 131. Riveted hole; 14. First arc-shaped transition portion; 15. First connecting portion; 20. Outer current-carrying terminal; 21. Outer spring sheet; 211. Elastic arm; 2111. Contact portion; 212. Outer guide portion; 22. Outer fixing portion; 221. Riveted wing; 23. Second arc-shaped transition portion; 24. Second connecting portion; 30. Protective shell; 31. Clamping arm; 40. Sealing structure; 41. Sealing groove; 42. Snap-in groove. DETAILED DESCRIPTION

[0043] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0044] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0045] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0046] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0047] According to a first aspect of the present invention, Figure 1-Figure 7 As shown, a double-layer terminal is provided for plugging with a mating terminal, comprising an inner current-carrying terminal 10, and an outer current-carrying terminal 20 sleeved outside at least part of the inner current-carrying terminal 10.

[0048] The inner current-carrying terminal 10 has an inserting section 11, in which an inserting cavity for inserting and electrically connecting with the mating terminal is arranged, and the outer current-carrying terminal 20 is at least sleeved on the outer periphery of the inserting section 11, and a radial through hole 112 is arranged on the inserting section 11. The outer current-carrying terminal 20 has an outer spring piece 21, and the outer spring piece 21 at least partially passes through the through hole 112 to be electrically connected with the mating terminal.

[0049] With the rapid development of new energy electric vehicles, the use of terminals for electrical connection is increasing. The terminals used in charging guns and charging seats are mainly used to transmit electrical signals or conduct electricity. The terminals need to be plugged into matching terminals to achieve electrical connection. In existing new energy vehicle charging seats, high-current terminals are generally made of copper materials and turned into shape, which can ensure the current conduction cross-sectional area and the contact retention force when the terminals are plugged in. However, the turning process has high processing costs and long working hours, and cannot reduce the terminal cost. Traditional stamping terminals have low processing costs and short working hours, but the current conduction cross-sectional area is small, the current carrying capacity is small, and the contact retention force when plugged in cannot meet the requirements. Moreover, within the limited national standard charging seat interface size, the traditional stamping terminal structure is also difficult to meet the current carrying requirements, and there is a problem of low current carrying capacity in a limited space.

[0050] The inner current-carrying terminal 10 and the outer current-carrying terminal 20 of the present invention are both integrally formed by stamping and curling of a plate, and the terminals are made using a stamping process, with low processing cost and short working hours. After the mating terminal is inserted into the inner current-carrying terminal 10, it first contacts the plug-in cavity, and then contacts the outer spring piece 21 of the outer current-carrying terminal 20. Both the inner current-carrying terminal 10 and the outer current-carrying terminal 20 are in contact with the mating terminal, which increases the current conduction cross-sectional area of ​​the mating terminal and the double-layer terminal, reduces the contact resistance, and multiplies the terminal current carrying capacity. After the inner current-carrying terminal 10 is sleeved with the outer current-carrying terminal 20, the overall occupied space changes very little, and the high current carrying capacity requirements of the power terminal can be met within the limited national standard charging seat interface size. Moreover, after the outer current-carrying terminal 20 is sleeved outside the inner current-carrying terminal 10, the outer spring piece 21 can also increase the clamping force of the plug-in cavity of the inner current-carrying terminal 10 on the mating terminal, and the contact retention force meets the requirements during insertion.

[0051] In some embodiments, Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown, part of the plug-in section 11 is divided into a plurality of inner spring sheets 111 by a plurality of axially extending expansion and contraction gaps 12, the expansion and contraction gaps 12 pass through the through hole 112, and an elastic arm 211 is provided on the outer spring sheet 21, the outer spring sheet 21 partially abuts against the inner spring sheet 111, and the free end of the elastic arm 211 extends into the through hole 112.

[0052] The outer spring piece 21 abuts against the inner spring piece 111 to strengthen the clamping of the inner spring piece 111 on the mating terminal. The free end of the elastic arm 211 extends into the through hole 112 and abuts against the mating terminal, increasing the contact area, reducing the contact resistance, and doubling the terminal current carrying capacity.

[0053] In some embodiments, Figure 2 As shown, the through holes 112 are symmetrically arranged along the center line of the expansion and contraction joint 12 .

[0054] This design is to enable the through holes 112 on both sides of the center line of the expansion and contraction joint 12 to form an oblong hole together with the expansion and contraction joint 12, so as to facilitate the central insertion of the elastic arm 211.

[0055] In some embodiments, after the mating terminal is plugged into the plug-in cavity, the outer peripheral surface of the mating terminal abuts and is electrically connected to the minimum inner diameter surrounded by the multiple elastic arms 211, and abuts and is electrically connected to part of the inner wall of the multiple inner spring sheets 111.

[0056] The mating terminal abuts and is electrically connected to the minimum inner diameter surrounded by the multiple elastic arms 211, and also abuts and is electrically connected to part of the inner wall of the multiple inner spring sheets 111, which can increase the contact area, reduce the contact resistance, and multiply the terminal current carrying capacity.

[0057] In some embodiments, Figure 2 As shown, the plurality of inner elastic sheets 111 are evenly arranged along the circumferential direction of the plug-in section 11 , and the inner diameter of the plug-in cavity gradually decreases along the direction from the extending starting end of the inner elastic sheet 111 to the free end of the inner elastic sheet 111 .

[0058] This design is to better clamp the mating terminal and prevent the mating terminal from falling off from the free end of the inner spring sheet 111 .

[0059] In some embodiments, Figure 1-Figure 3 As shown, the free ends of the multiple inner spring pieces 111 are bent outwardly away from the axis of the plug-in section 11 to form an inner guide portion 113, and the free ends of the multiple outer spring pieces 21 are bent outwardly toward the axis of the plug-in section 11 to form an outer guide portion 212 matching the inner guide portion 113.

[0060] The inner guide portion 113 guides the mating terminal when it is inserted into the plug-in cavity, and the outer guide portion 212 protects the inner guide portion 113, strengthens the overall structural strength of the inner guide portion 113, and prevents the inner guide portion 113 from being worn or damaged during repeated insertion and removal of the mating terminal.

[0061] In some embodiments, Figure 1-Figure 3 As shown, the number of the outer elastic sheets 21 and the number of the expansion and contraction seams 12 are the same.

[0062] The number of outer spring pieces 21 is the same as the number of expansion and contraction joints 12. The elastic arms 211 can correspond to the positions of the expansion and contraction joints 12 one by one and pass through the through holes 112 to be electrically connected to the mating terminals, thereby increasing the contact area, reducing the contact resistance, and doubling the terminal current carrying capacity. It can also ensure that the inner spring pieces 111 on both sides of each expansion and contraction joint 12 can be abutted by the outer spring pieces 21, thereby strengthening the elasticity of the inner spring pieces 111 and increasing the clamping of the inner spring pieces 111 to the mating terminals.

[0063] In some embodiments, Figure 1 As shown, the plurality of outer spring sheets 21 are evenly spaced along the circumference of the outer current-carrying terminal 20 , and each outer spring sheet 21 is symmetrically pressed outside two adjacent inner spring sheets 111 along the center line of the expansion and contraction gap 12 .

[0064] This structural design is to ensure that the inner spring pieces 111 on both sides of the expansion and contraction joint 12 can be subjected to the same abutment and clamping force from the outer spring pieces 21, to balance the clamping of each inner spring piece 111 to the mating terminal, to prevent the single inner spring piece 111 from being severely worn prematurely or the clamping force from being insufficient, and to extend the service life of the inner current-carrying terminal 10.

[0065] In some embodiments, the plurality of elastic arms 211 are provided with contact portions 2111 bent toward the axis of the plug section 11 , and the outer peripheral surface of the mating terminal abuts against and is electrically connected to the minimum inner diameter surrounded by the plurality of contact portions 2111 .

[0066] The contact portion 2111 can strengthen the clamping of the elastic arm 211 on the mating terminal, ensure the stable electrical connection between the mating terminal and the double-layer terminal during power use, and ensure the safety of power use.

[0067] In some embodiments, a plating layer is provided at least on a region where the outer circumference of the inner current-carrying terminal 10 and the inner circumference of the outer current-carrying terminal 20 contact each other.

[0068] The provided plating layer mainly serves to increase the wear resistance, corrosion resistance and conductivity, and prevents the outer circumference of the inner current-carrying terminal 10 and the inner circumference of the outer current-carrying terminal 20 from being worn during the process of sheathing the outer current-carrying terminal 20 and the inner current-carrying terminal 10, during the process of plugging the mating terminals, and during the use of the double-layer terminals, thereby preventing the resistance from increasing, generating electricity use risks, and shortening the life of the terminals due to wear or damage.

[0069] In some embodiments, Figure 1 As shown, the inner current-carrying terminal 10 has a fixing section 13 connected to the plug-in section 11, and the outer current-carrying terminal 20 has an outer fixing portion 22 connected to the plurality of outer spring sheets 21. After the outer current-carrying terminal 20 is sleeved outside the inner current-carrying terminal 10, the outer fixing portion 22 covers the entire fixing section 13.

[0070] The outer fixing portion 22 covers the entire fixing section 13, strengthens the connection between the outer current-carrying terminal 20 and the inner current-carrying terminal 10, reduces the contact resistance between the two layers, and protects the outer wall of the fixing section 13 from corrosion and bumping caused by environmental influences.

[0071] In some embodiments, Figure 2 , Figure 3 and Figure 6 As shown, one of the fixing section 13 and the outer fixing portion 22 is provided with a rivet hole 131 , and the other is provided with a rivet wing 221 , and the rivet wing 221 is snapped or riveted with the rivet hole 131 to fix the outer current-carrying terminal 20 and the inner current-carrying terminal 10 to each other.

[0072] In some embodiments, Figure 5 As shown, an integral sealing structure 40 is injection molded on part of the interior of the fixing section 13 and part of the outer wall of the outer fixing portion 22 . The sealing structure 40 intrudes from the outer fixing portion 22 into the interior of the fixing section 13 and seals the interior of the fixing section 13 .

[0073] The sealing structure 40 plays a sealing role, which can prevent moisture and impurities in the use environment from entering the inner current-carrying terminal 10 and affecting the plug-in electrical connection between the plug-in cavity and the elastic arm 211 and the mating terminal.

[0074] In some embodiments, Figure 5 As shown, at least one circumferential sealing groove 41 is provided along the outer wall of the sealing structure 40 for mounting a sealing ring.

[0075] The sealing ring in the sealing groove 41 is used to seal the gap between the double-layer terminal and the installation environment to prevent moisture from entering the double-layer terminal and affecting the electrical connection between the double-layer terminal and the mating terminal, as well as the electrical connection between the double-layer terminal and the cable, thereby ensuring electrical safety.

[0076] In some embodiments, Figure 5 As shown, a clamping groove 42 spaced apart from the sealing groove 41 is further provided on the outer wall of the sealing structure 40 for clamping with a fixed position.

[0077] The snap-in groove 42 is snap-fitted with the fixed position, so as to fix the double-layer terminal, facilitate the plugging of the mating terminal, and ensure that the double-layer terminal does not shake when using electricity, thereby ensuring the safety of electricity transmission.

[0078] In some embodiments, Figure 7 As shown, the cross-sectional shapes of the outer fixing portion 22 and the fixing section 13 where the sealing structure 40 is arranged are both arc-shaped and / or porous ring-shaped.

[0079] The outer fixing portion 22 and the fixing section 13 of the arc-shaped and / or porous annular structure facilitate the integral injection molding of the sealing structure 40 on the double-layer terminal.

[0080] In some embodiments, Figure 1-Figure 3 As shown, the inner current-carrying terminal 10 has a first connecting portion 15 connected to the fixed section 13, and the outer current-carrying terminal 20 has a second connecting portion 24 connected to the outer fixed portion 22. The first connecting portion 15 and the second connecting portion 24 are at least partially relatively fitted and connected, and are used to connect the same conductor.

[0081] The first connection part 15 and the second connection part 24 are at least partially relatively attached and connected to form an integrated wiring part. The double-layer integrated wiring part has high power and large current carrying capacity. The same conductor is connected, and the conductor can be a high-power conductor, which increases the overall current carrying capacity of the double-layer terminal.

[0082] In some embodiments, Figure 2-Figure 3 As shown, a first arc-shaped transition portion 14 is provided between the fixing section 13 and the first connecting portion 15, and a second arc-shaped transition portion 23 is provided between the outer fixing portion 22 and the second connecting portion 24. The first arc-shaped transition portion 14 and the second arc-shaped transition portion 23 are arranged opposite to each other.

[0083] The addition of the arc-shaped transition portion is beneficial to the forming of the inner current-carrying terminal 10 and the outer current-carrying terminal 20 , and is also beneficial to the outer current-carrying terminal 20 being sleeved outside the inner current-carrying terminal 10 , especially the two can be more easily formed by a stamping process.

[0084] In some embodiments, Figure 5 and Figure 6 As shown, it also includes a protective shell 30 sleeved outside the external current-carrying terminal 20, and the outer wall of the protective shell 30 is provided with a plurality of clamping arms 31 arranged at intervals, and at least part of the clamping arms 31 are pressed outside the external spring sheet 21 to strengthen the clamping of the matching terminal by the elastic arm 211 and the internal spring sheet 111.

[0085] In some embodiments, the protective shell 30 is made of steel or stainless steel, and the inner current-carrying terminal 10 and the outer current-carrying terminal 20 are made of copper or copper alloy.

[0086] The double-layer terminal composed of the inner current-carrying terminal 10 and the outer current-carrying terminal 20 made of copper or copper alloy has poor fatigue resistance. Due to repeated plugging and unplugging, the elasticity becomes smaller, resulting in an enlarged plug cavity. The clamping force of the mating terminals is insufficient, resulting in increasing contact resistance, aggravated temperature rise, and electrical risks.

[0087] The double-layer terminal of the present invention is provided with a protective shell 30 made of steel or stainless steel. The steel or stainless steel has good fatigue resistance. The protective shell 30 with good fatigue resistance increases the clamping force of the double-layer terminal on the mating terminal. The double-layer terminal and the mating terminal are not easily deformed during repeated plugging and unplugging, which increases the number of plugging and unplugging times and improves the service life of the double-layer terminal.

[0088] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A double-layer terminal for plugging with a mating terminal. It is characterized in that It comprises an inner current-carrying terminal and an outer current-carrying terminal sleeved outside at least part of the inner current-carrying terminal. The inner current-carrying terminal has an insertion section, in which an insertion cavity is provided for plugging in and electrically connecting with the mating terminal. The outer current-carrying terminal is at least sleeved on the outer periphery of the insertion section, and the insertion section is provided with a radial through hole. The outer current-carrying terminal has an outer spring sheet, and the outer spring sheet at least partially passes through the through hole to be electrically connected with the mating terminal.

2. A double-layer terminal according to claim 1, It is characterized in that Part of the plug-in section is divided into multiple inner elastic sheets by multiple axially extending expansion and contraction gaps, the expansion and contraction gaps pass through the through hole, and the outer elastic sheet is provided with an elastic arm, the outer elastic sheet partially abuts the inner elastic sheet, and the free end of the elastic arm extends into the through hole.

3. A double-layer terminal according to claim 2, It is characterized in that The through holes are symmetrically arranged along the midline of the expansion and contraction seam.

4. A double-layer terminal according to claim 2, It is characterized in that After the mating terminal is plugged into the plug-in cavity, the outer peripheral surface of the mating terminal abuts against and is electrically connected to the minimum inner diameter surrounded by the multiple elastic arms, and abuts against and is electrically connected to part of the inner walls of the multiple inner spring sheets.

5. A double-layer terminal according to claim 2, It is characterized in that The plurality of inner elastic sheets are evenly arranged along the circumference of the plug-in section, and the inner diameter of the plug-in cavity gradually decreases along the direction from the extending starting end of the inner elastic sheet to the free end of the inner elastic sheet.

6. A double-layer terminal according to claim 5, It is characterized in that The free ends of the multiple inner spring pieces are bent outwardly away from the axis of the plug-in section to form an inner guide portion, and the free ends of the multiple outer spring pieces are bent outwardly close to the axis of the plug-in section to form an outer guide portion matching the inner guide portion.

7. A double-layer terminal according to claim 2, It is characterized in that The number of the outer spring sheets is the same as the number of the expansion and contraction joints.

8. A double-layer terminal according to claim 7, It is characterized in that The plurality of outer spring sheets are evenly arranged at intervals along the circumference of the outer current-carrying terminal, and each outer spring sheet is symmetrically pressed outside two adjacent inner spring sheets along the center line of the expansion and contraction seam.

9. A double-layer terminal according to claim 2, It is characterized in that The plurality of elastic arms are provided with contact portions bent toward the axis direction of the plug-in section, and the outer peripheral surface of the mating terminal abuts against and is electrically connected to the minimum inner diameter surrounded by the plurality of contact portions.

10. A double-layer terminal according to claim 1, It is characterized in that A plating layer is provided at least on a region where the outer circumference of the inner current-carrying terminal and the inner circumference of the outer current-carrying terminal contact each other.

11. A double-layer terminal according to claim 1, It is characterized in that The inner current-carrying terminal has a fixing section connected to the plug-in section, and the outer current-carrying terminal has an outer fixing portion connected to the plurality of outer spring sheets. After the outer current-carrying terminal is sleeved outside the inner current-carrying terminal, the outer fixing portion covers the entire fixing section.

12. A double-layer terminal according to claim 11, It is characterized in that One of the fixing section and the outer fixing portion is provided with a rivet hole, and the other is provided with a rivet wing, and the rivet wing is clamped or riveted with the rivet hole to fix the outer current-carrying terminal and the inner current-carrying terminal to each other.

13. A double-layer terminal according to claim 11, It is characterized in that An integral sealing structure is injection-molded on a portion of the interior of the fixing section and a portion of the outer wall of the outer fixing portion. The sealing structure intrudes from the outside of the outer fixing portion into the interior of the fixing section and seals the interior of the fixing section.

14. A double-layer terminal according to claim 13, It is characterized in that At least one circumferential sealing groove is arranged along the outer wall of the sealing structure for installing a sealing ring.

15. A double-layer terminal according to claim 14, It is characterized in that The outer wall of the sealing structure is also provided with a clamping groove spaced apart from the sealing groove, for clamping with a fixed position.

16. A double-layer terminal according to claim 13, It is characterized in that The cross-sectional shapes of the positions where the sealing structure is arranged on the outer fixing portion and the fixing section are both arc-shaped and / or porous ring-shaped.

17. A double-layer terminal according to claim 11, It is characterized in that The inner current-carrying terminal has a first connection portion connected to the fixed section, and the outer current-carrying terminal has a second connection portion connected to the outer fixed portion. The first connection portion and the second connection portion are at least partially relatively fitted and connected, and are used to connect the same conductor.

18. A double-layer terminal according to claim 17, It is characterized in that A first arc-shaped transition portion is arranged between the fixing section and the first connecting portion, a second arc-shaped transition portion is arranged between the outer fixing portion and the second connecting portion, and the first arc-shaped transition portion and the second arc-shaped transition portion are arranged opposite to each other.

19. A double-layer terminal according to claim 2, It is characterized in that It also includes a protective shell sleeved outside the external current-carrying terminal, the outer wall of the protective shell is provided with a plurality of clamping arms arranged at intervals, at least part of the clamping arms are pressed outside the external spring sheet to strengthen the clamping of the elastic arm and the internal spring sheet on the mating terminal.

20. A double-layer terminal according to claim 19, It is characterized in that The material of the protective shell is steel or stainless steel, and the material of the inner current-carrying terminal and the outer current-carrying terminal is copper or copper alloy.

Images