TWI838637B - Electric vehicle charging connector - Google Patents

Abstract

The present invention relates to a charging connector for electric vehicles, which mainly comprises a first conductive terminal in a hollow cylindrical shape provided in a connector base, an insulating isolator provided in the first conductive terminal, and a second conductive terminal provided in the center of the isolator, so that the second conductive terminal is coaxially and electrically isolated from the first conductive terminal; wherein the isolator is formed with one or more annular grooves recessed from the surface, the annular grooves coaxially surround the second conductive terminal, thereby lengthening the creepage distance between the positive terminal and the negative terminal, and expanding the heat dissipation area to meet safety requirements.

Description

Charging connector for electric vehicles

The present invention relates to a charging connector, and more particularly to a charging connector for electric vehicles that is specially designed to increase creepage distance and electrical clearance.

According to the Chinese national standard GB 24155-2020 "Safety requirements for electric motorcycles and electric mopeds", specific specifications are made for the creepage distance and electrical clearance of the charging interface. Among them, the creepage distance of the power storage battery should meet the following requirements:

1. The creepage distance d1 between the power battery connection terminals is calculated according to the following formula (1), the unit is mm:

2. The creepage distance d2 between live parts and the electrical platform is calculated according to the following formula (2), in mm:

U in the above formula (1) and formula (2) is the maximum operating voltage between the two output terminals of the power storage battery, in volts.

In addition, the electrical gap between conductive parts should be no less than 2.5mm.

As shown in FIG8 , the measurement method of electrical gap and creepage distance can be known, which reveals two connecting terminals 71 and 72 on a carrier 70. The two connecting terminals 71 and 72 have a conductive surface 710 and 720 respectively. The distance between the two conductive surfaces 710 and 720 is the electrical gap G, and the distance between the two connecting terminals 71 and 72 along the surface of the carrier 70 is the creepage distance D.

As can be seen from the above, mainland China has the above creepage distance and electrical clearance requirements for the charging interface of electric vehicles. Please refer to Figures 9 and 10, which disclose a conventional electric vehicle connector. It mainly comprises a negative terminal 81 in a connector base 80, a positive terminal 82 is coaxially and electrically isolated in the negative terminal 81, and the negative terminal 81 is in a hollow cylindrical shape, and has an upper slot chamber 811 and a lower slot chamber 812 connected thereto, wherein the inner diameter of the upper slot chamber 811 is always larger than that of the lower slot chamber 812. 2. A crown spring 813 is disposed in the upper slot chamber 811. The crown spring 813 is electrically connected to the negative terminal 81 and has a plurality of contact springs. Each contact spring extends in an axial direction to form a contact point. When the above connector is connected to a corresponding connector, the crown spring 813 is the main conductive medium of the negative power source, and its contact point serves as the conductive surface of the negative terminal 81.

In order to realize that the negative terminal 81 is coaxially and electrically isolated from the positive terminal 82, an insulating seat 83 is provided in the lower slot 812 in a matching shape, and the positive terminal 82 is provided in the center of the insulating seat 83. Through the provision of the insulating seat 83, the positive terminal 82 is electrically isolated from the negative terminal 81. According to the requirements of the above-mentioned Chinese national standard, the working voltage of this type of connector is 50.4 volts. According to the above-mentioned formula (1), the creepage distance must be greater than or equal to 17.6 mm (0.25x50.4+5), and the electrical clearance must be greater than 2.5 mm. Corresponding to the above connector, it means that the creepage distance from the negative terminal 81 along the surface of the insulating seat 83 to the positive terminal 82 must be greater than 17.6mm, and the contact point of the crown spring 813, as the conductive surface of the negative terminal 81, must have an electrical gap greater than 2.5mm with the positive terminal 82. However, as shown in FIG11 , according to the actual measurement results, the electrical gap G1 from the contact point of the crown spring 813 to the positive terminal 82 of the negative terminal 81 is 5.375mm, which is greater than the standard 2.5mm and meets the safety requirements. However, the creepage distance D1 from the negative terminal 81 to the positive terminal 82 along the surface of the insulating seat 83 is only 3.8 mm, which is far below the safety requirement of 17.6 mm and does not meet the regulations.

The above connector also faces the problem of creepage distance not meeting safety requirements in terms of external connection. Please refer to Figures 12 and 13. The negative terminal 81 and the positive terminal 82 are connected to an electrical connection piece 84 and 85 respectively. One end of the two electrical connection pieces 84 and 85 is fixed to the bottom of the negative terminal 81 and the positive terminal 82 respectively, and the other end is bent and extended to the bottom of the connector base 80 for external electrical connection. Based on the specification requirements of the connector, the two electrical connection pieces 84 and 85 are arranged at two adjacent positions at the bottom of the connector base 80. The shortest distance D2 between them is 6.20mm, which meets the requirement that the electrical gap must be greater than or equal to 2.5mm, but the creepage distance is far less than the requirement of at least 17.6mm.

From the above, it can be seen that existing electric vehicle connectors cannot meet safety requirements in terms of creepage distance, so further review is needed to seek a feasible solution.

Therefore, the main purpose of the present invention is to provide a charging connector for electric vehicles, which meets safety requirements by expanding the creepage distance and electrical clearance through special terminals and insulation structures.

The main technical means adopted to achieve the above-mentioned purpose is to make the above-mentioned electric vehicle charging connector include: a connector base; a first conductive terminal, one end of which is arranged in the connector base and the other end is exposed from the connector base; the first conductive terminal is in the shape of a hollow cylinder, and has an upper groove chamber and a lower groove chamber inside, and the lower groove chamber is further formed with a retracted groove wall to expand the inner diameter of the lower groove chamber; an isolator is arranged in the lower groove chamber of the first conductive terminal in a matching shape; the surface of the isolator is coaxially formed with an annular groove that is concave downward; a second conductive terminal is arranged at the center of the isolator, and is coaxially and electrically isolated in the first conductive terminal, one end of the second conductive terminal is located in the upper groove chamber of the first conductive terminal, and the other end passes through the bottom of the isolator.

The first conductive terminal of the connector has an inwardly contracted groove wall formed in its lower groove chamber to expand the inner diameter of the lower groove chamber and relatively increase the outer diameter of the isolating member disposed therein, thereby extending the creepage distance from the first conductive terminal along the surface of the isolating member to the second conductive terminal; furthermore, an annular groove recessed from the surface is formed on the isolating member, thereby significantly extending the creepage distance from the first conductive terminal along the surface of the isolating member to the second conductive terminal, and on the other hand, the heat dissipation area on the surface of the isolating member can be expanded, thereby fully meeting the safety requirements.

10: Connector base

11: High platform

20: First conductive terminal

200: First terminal

201, 301: Insulation layer

21: Upper tank room

22: Lower tank room

220: Inwardly contracted groove wall

23: Crown spring

230: Contact point

30: Second conductive terminal

300: Second terminal

31: Upper channel

32: Lower channel

33: Elastic contact

331: Sheung Wan

332: Lower Ring

333: Contact reed

34: Contact spring

341: Closing part

342: dense winding section

35: Studs

40: Isolation parts

41: Outer ring groove

42: Inner ring groove

420: Class

70: Carrier

71, 72: Connecting terminals

710, 720: Conductive surface

80: Connector base

81: First conductive terminal

811: Upper tank room

812: Lower tank room

813: Crown spring

82: Second conductive terminal

83: Seat of Absolute Destiny

84, 85: Electrical connector

Figure 1 is a three-dimensional diagram of a preferred embodiment of the present invention.

Figure 2 is a cross-sectional view of a preferred embodiment of the present invention.

Figure 3 is a partial cross-sectional view of a preferred embodiment of the present invention.

Figure 4 is a partial cross-sectional view of a preferred embodiment of the present invention.

Figure 5 is a disassembled diagram of the elastic contact piece and contact spring of a preferred embodiment of the present invention.

Figure 6 is a bottom view of a preferred embodiment of the present invention.

Figure 7 is a bottom plan view of a preferred embodiment of the present invention.

Figure 8 is a schematic diagram of creepage distance calculation.

Figure 9 is a three-dimensional diagram of an existing electric vehicle connector.

Figure 10 is a cross-sectional view of an existing electric vehicle connector assembly.

Figure 11 is a partial cross-sectional view of a conventional electric vehicle connector.

Figure 12 is a bottom perspective view of a conventional electric vehicle connector.

Figure 13 is a bottom plan view of a conventional electric vehicle connector.

Regarding a preferred embodiment of the present invention, please refer to FIG. 1 and FIG. 2 , which mainly comprises a first conductive terminal 20 provided in a connector base 10, and a second conductive terminal 30 provided coaxially and electrically isolated in the first conductive terminal 20; the first conductive terminal 20 can be a negative conductive terminal or a positive conductive terminal, and the second conductive terminal 30 can be a positive conductive terminal or a negative conductive terminal correspondingly. In the following embodiments, the first conductive terminal 20 is used as a negative conductive terminal, and the second conductive terminal 30 is used as a positive conductive terminal, but it must be explained that the aforementioned first and second conductive terminals 20 and 30 are used as negative and positive conductive terminals respectively for example only, and are not used to limit their functions.

The connector base 10 is hollow, and a protruding, ring-shaped platform 11 is formed at its upper end. The first conductive terminal 20 is provided in a matching shape inside the platform 11.

The first conductive terminal 20 is in the shape of a hollow cylinder, one end of which is located inside the platform 11 of the connector base 10, and the other end is protruding outside the platform 11. The first conductive terminal 20 has an upper slot chamber 21 and a lower slot chamber 22 connected to each other formed inside. The inner diameter of the upper slot chamber 21 is larger than the inner diameter of the lower slot chamber 22. The lower slot chamber 22 further has a retracted slot wall 220, which is mainly used to make the lower slot chamber 22 retract through the slot wall to relatively expand the inner diameter of the lower slot chamber 22.

An isolating member 40 is provided in the lower groove chamber 22 of the first conductive terminal 20 in a matching shape. The isolating member 40 is made of an insulating material and has a surface exposed at the bottom of the upper groove chamber 21. The surface of the isolating member 40 is coaxially formed with an annular groove that is concave downward. Please refer to FIG. 3 . In this embodiment, an outer annular groove 41 and an inner annular groove 42 are formed on the surface of the isolating member 40. The outer annular groove 41 is located at the outer periphery of the inner annular groove 42 and has a larger outer diameter and a larger depth. The depth of the outer annular groove 41 is greater than half the height of the isolating member 40. The inner annular groove 42 is closer to the center of the isolation member 40 than the outer annular groove 41. The depth of the inner annular groove 42 is always less than the depth of the outer annular groove 41. A step 420 is formed on a side wall close to the center.

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)加總所得，經過具體實測該爬電距離可達18.23mm，滿足大於17.6mm的安全要求。 The second conductive terminal 30 is disposed at the center of the isolating member 40 and is surrounded by an outer annular groove 41 and an inner annular groove 42 on the surface of the isolating member 40 . One end of the second conductive terminal 30 is exposed in the upper groove chamber 21 of the first conductive terminal 20 , and the other end thereof is passed through the bottom of the isolating member 40 . Please refer to FIG. 3 . Since the inner diameter of the lower groove chamber 22 of the first conductive terminal 20 is enlarged by forming an inward groove wall 220, the outer diameter of the isolating member 40 is relatively enlarged, thereby extending the creepage distance between the first conductive terminal 20 and the second conductive terminal 30 in the horizontal direction. On the other hand, the outer annular groove 41 and the inner annular groove 42 that are concave downward are formed on the surface of the isolating member 40, and the creepage distance is further extended in the vertical direction. Please refer to FIG. 4 . The specific creepage distance between the first conductive terminal 20 and the second conductive terminal 30 is the distance of the multiple height differences on the surface of the isolating member 40 (

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) are added together, and after specific actual measurement, the creepage distance can reach 18.23mm, which meets the safety requirement of being greater than 17.6mm.

On the other hand, since the isolator 40 has an outer annular groove 41 and an inner annular groove 42 formed on its surface, the surface area of the isolator 40 is greatly enlarged, so that the surface of the isolator 40 has a larger heat dissipation area.

Regarding the electrical gap, please refer to FIG3 . A crown spring 23 is electrically connected in the upper slot chamber 21 of the first conductive terminal 20 . The crown spring 23 has a plurality of contact spring pieces. Each contact spring piece extends toward an axial direction of the first conductive terminal 20 to form a contact point 230 . The electrical gap between the first conductive terminal 20 and the second conductive terminal 30 is the distance from the contact point 230 of the crown spring 23 to the second conductive terminal 30 , which is always greater than the safety requirement of 2.5 mm.

The specific structure of the second conductive terminal 30 is further described below. Please refer to FIG. 2. The second conductive terminal 30 is a narrow and long hollow tube, and an upper hole 31 and a lower hole 32 are formed inside the second conductive terminal 30. The diameter of the upper hole 31 is larger than that of the lower hole 32, and the lower hole 32 is a screw hole. The second conductive terminal 30 is provided with an elastic contact 33 and a contact spring 34 in the upper hole 31. The contact spring 34 is located at the lower end of the upper hole 31. The elastic contact 33 is in the form of a crown spring, located at the upper end of the upper hole 31 and above the contact spring 34.

Please refer to FIG. 5 . The elastic contact member 33 includes an upper ring 331, a lower ring 332, and a plurality of contact springs 333 connected to the upper ring 331 and the lower ring 332 at both ends. Each contact spring 333 extends toward an axial direction of the upper ring 331 and the lower ring 332 to form a contact point. In this embodiment, the distance between the contact point of each contact spring 333 and the lower ring 332 is greater than the distance between the contact point and the upper ring 331. Compared with the traditional crown spring, the elastic contact member 33 has a longer length (force arm) of the contact spring 333, which can extend the service life of the elastic contact member 33.

The upper end of the contact spring 34 has a contraction portion 341, the outer diameter of which is smaller than the inner diameter of the lower ring 332 of the elastic contact piece 33 and larger than the inner diameter of the elastic contact piece 33 at its contact point, so that the contraction portion 341 is located below the contact point of the elastic contact piece 33. The lower end of the contact spring 34 has a densely wound portion 342, please refer to FIG. 3, the contact spring 34 is provided with a stud 35 at the lower end of its densely wound portion 342, and the stud 35 is screwed into the lower hole 32 of the second conductive terminal 30, thereby fixing the contact spring 34 in the upper hole 31 of the second conductive terminal 30.

As shown in FIG. 1 and FIG. 6 , a first contact piece 200 and a second contact piece 300 are provided at the bottom side of the connector base 10. The first contact piece 200 and the second contact piece 300 are opposite to each other at an angle, and one end thereof is electrically connected to the bottom of the first conductive terminal 20 and the second conductive terminal 30 respectively inside the connector base 10. The first contact piece 200 and the second contact piece 300 extend vertically from the bottom of the connector base 10, and then twist and extend horizontally. The first terminal 200 and the second terminal 300 are extended so that the other ends are arranged in parallel (please refer to FIG. 7). The first terminal 200 and the second terminal 300 are exposed outside the connector base 10. Except for the exposed power supply connection at the tail end, they are respectively covered with an insulating layer 201 and 301. By using the setting of the insulating layer 201 and 301, the creepage distance of the first terminal 200 and the second terminal 300 can be greatly extended, and can fully meet the safety requirements.

According to the above-mentioned specific embodiments, the present invention enlarges the inner diameter of the lower groove chamber of the first conductive terminal, thereby lengthening the outer diameter of the isolator, and extending the creepage distance between the first conductive terminal and the second conductive terminal in the horizontal direction, and the surface of the isolator forms more than one concave annular groove, which further enlarges the aforementioned creepage distance in the vertical direction, and the sufficient distance meets the requirements of safety regulations; furthermore, when the annular groove is formed on the surface of the isolator, its surface area is also significantly enlarged, which helps to increase the heat dissipation area of the isolator. On the other hand, the first and second terminals for external connection are covered with an insulating layer on the part exposed to the connector base, so that the creepage distance between the first and second terminals can also meet the safety requirements.

11: High platform

20: First conductive terminal

21: Upper tank room

22: Lower tank room

220: Inwardly contracted groove wall

23: Crown spring

230: Contact point

30: Second conductive terminal

31: Upper channel

32: Lower channel

33: Elastic contact

34: Contact spring

35: Studs

40: Isolation parts

41: Outer ring groove

42: Inner ring groove

420: Class

Claims (9)

A charging connector for an electric vehicle comprises: a connector base; a first conductive terminal, one end of which is arranged in the connector base and the other end is exposed from the connector base; the first conductive terminal is in a hollow cylindrical shape, and has an upper groove chamber and a lower groove chamber inside, and the lower groove chamber is further formed with an inwardly contracted groove wall to expand the inner diameter of the lower groove chamber; an isolating member is arranged in the lower groove chamber of the first conductive terminal in a matching shape; the surface of the isolating member is coaxially formed with one or more downwardly concave An annular groove is provided to increase the creepage distance between the first conductive terminal and the second conductive terminal; a second conductive terminal is provided at the center of the isolating element, and is coaxially and electrically isolatedly provided inside the first conductive terminal, one end of the second conductive terminal is provided inside the upper groove chamber of the first conductive terminal, and the other end is provided outside the bottom of the isolating element; wherein the one or more downwardly concave annular grooves formed on the surface of the isolating element include an outer annular groove and an inner annular groove, and the outer annular groove is provided outside the inner annular groove. In the electric vehicle charging connector described in claim 1, the depth of the outer ring groove is greater than half the height of the isolating element. As described in claim 1, the depth of the inner annular groove is always less than the depth of the outer annular groove, and a step is formed on a side wall near the center of the isolation member. As described in claim 1, the second conductive terminal is a narrow hollow tube, and an upper hole and a lower hole are formed inside the second conductive terminal, and the diameter of the upper hole is larger than the diameter of the lower hole. The second conductive terminal is provided with an elastic contact and a contact spring in the upper hole, and the contact spring is located at the lower end of the upper hole, and the elastic contact is located at the upper end of the upper hole and above the contact spring. As described in claim 4, the electric vehicle charging connector, the elastic contact is in the form of a crown spring, which includes an upper ring and a lower ring, and the two ends of the contact spring are respectively connected to the upper ring and the lower ring. Each contact spring extends toward an axial direction of the upper ring and the lower ring to form a contact point. The distance between the contact point of each contact spring and the lower ring is greater than the distance between the contact point and the upper ring. As described in claim 4, the charging connector for electric vehicles has a contraction portion at the upper end of the contact spring, the outer diameter of which is smaller than the inner diameter of the lower ring of the elastic contact piece and larger than the inner diameter of the elastic contact piece at its contact point, and the contraction portion is located below the contact point of each contact spring leaf of the elastic contact piece. As described in claim 6, the lower hole of the second conductive terminal is a screw hole; the lower end of the contact spring has a densely wound portion, and a stud is passed through the lower end of the densely wound portion of the contact spring, and the stud is screwed into the lower hole of the second conductive terminal. As described in claim 1, the charging connector for electric vehicles has a first contact piece and a second contact piece on one side of the bottom of the connector base. The first contact piece and the second contact piece are opposite to each other at an angle, and one end thereof is electrically connected to the bottom of the first conductive terminal and the second conductive terminal respectively inside the connector base. The first contact piece and the second contact piece are exposed outside the connector base, and are respectively covered with an insulating layer except for the exposed power supply connection at the tail end. As described in claim 8, the first terminal and the second terminal extend vertically from the bottom of the connector base, and then twist and extend horizontally, so that the other ends of the first terminal and the second terminal are arranged in parallel.

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