CN218039882U

CN218039882U - Barrel type terminal and terminal connecting structure

Info

Publication number: CN218039882U
Application number: CN202221751424.8U
Authority: CN
Inventors: 王超; 陈昊
Original assignee: Changchun Jetty Automotive Parts Co Ltd
Current assignee: Changchun Jetty Automotive Parts Co Ltd
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2022-12-13
Anticipated expiration: 2032-07-08

Abstract

A barrel-type terminal and a terminal connecting structure relate to the technical field of electric energy transmission. Comprises a terminal body, a connecting part, a drum spring and a protective part; the drum spring comprises at least two elastic sheets protruding towards the axial direction; the connecting part is cylindrical, one end of the connecting part is connected with the terminal body, and the other end of the connecting part is provided with at least two through grooves along the axial direction; the drum spring is sleeved on the connecting part, and the elastic sheet penetrates through the through groove and protrudes out of the inner wall of the connecting part; the protection part is cylindrical and is sleeved on the periphery of the drum spring in a matching manner. The utility model provides a problem that the junction wearing and tearing back became invalid but can not local change between the terminal, the drum spring can make the terminal that connects the socket each other have bigger insertion force big, can also provide elastic contact, when preventing that the terminal rigidity from inserting the contact, the terminal decentraction leads to the serious condition of contact department wearing and tearing to appear, and then avoids resistance rising, and operating temperature risees, electric energy transmission power decline scheduling problem.

Description

Barrel type terminal and terminal connecting structure

Technical Field

The utility model relates to an electric energy transmission technical field, concretely relates to cylinder terminal and terminal connection structure.

Background

In the field of electrical connection, a plurality of electrical circuits need to be connected through plug terminals, at present, most of the electrical circuits are connected by plug-in connection of male terminals and female terminals, and particularly, on large-current and large-wire-diameter wire harnesses, such as a charging gun head and a charging seat for charging batteries of a rapidly developed new energy automobile, the internal terminals are of a structure in which the male terminals and the female terminals are plugged in opposite directions. In order to prevent the male terminal and the female terminal from being separated easily, the inserting and pulling force generated by friction between the male terminal and the female terminal is large, and after the male terminal and the female terminal are inserted and pulled for a long time, the phenomenon of serious abrasion can be generated, so that the charging efficiency is reduced in the charging process of a new energy automobile, the working temperature is greatly increased, and the spontaneous combustion risk is easily generated. Moreover, in the existing charging seat terminal structure, after the contact part of the male terminal and the female terminal is worn, the male terminal and the female terminal cannot be replaced, only the whole terminal can be replaced, and the charging seat or the charging gun needs to be disassembled to replace the terminal, so that manpower and material resources are wasted. Therefore, there is a need in the art for a new solution to solve the above problems.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a cylinder terminal and terminal connection structure can solve behind the terminal wearing and tearing inefficacy back and can not change, and the plug power is big, to joining in marriage the public end decentraction, and contact jaw wearing and tearing shortcoming such as serious.

A barrel-type terminal includes a terminal body, a connecting portion, a drum spring, and a protector;

the drum spring comprises at least two elastic sheets protruding towards the axial direction;

the connecting part is cylindrical, one end of the connecting part is connected with the terminal body, and the other end of the connecting part is provided with at least two through grooves along the axial direction;

the drum spring is sleeved on the connecting part, and at least part of the elastic sheet penetrates through the through groove and protrudes out of the inner wall of the connecting part;

the protection part is cylindrical and is sleeved on the periphery of the drum spring in a matching manner.

The connecting part and the terminal body are integrally formed.

The drum spring comprises a first base band and a second base band, the first base band and the second base band are arranged at two ends of the elastic sheet, a first annular groove and a second annular groove are formed in the connecting portion, the first base band is arranged in the first annular groove, and the second base band is arranged in the second annular groove.

The drum spring has at least one axial indentation.

The protective part is in threaded connection or clamped connection with the outer wall of the connecting part.

The terminal body is made of copper or copper alloy.

A terminal connection structure: the cylindrical terminal and the plug terminal are connected in an inserting mode, the plug terminal is cylindrical and is provided with a groove connected with the elastic sheet in a clamping mode.

The groove is a circumferential groove arranged along the circumferential direction of the plug terminal.

The insertion force of the barrel-type terminal and the insertion terminal is 6N-350N.

And the surface of the groove is provided with a wear-resistant coating.

The wear-resistant coating is made of one of gold, silver, nickel, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy.

The pressure applied to the plug terminal by the elastic sheet is 0.5N-188N.

The nominal contact area of the spring plate and the plug terminal is 0.015mm ² -9mm ² 。

The beneficial effects of the utility model are that: the problem of the junction wearing and tearing back inefficacy but can not local change between the terminal is solved, and the drum spring can make the terminal of mutual grafting have bigger insertion force big, can also provide elastic contact, when preventing that the contact is inserted to the terminal rigidity, the terminal decentraction leads to the serious condition of contact department wearing and tearing to appear, and then avoids resistance rising, and operating temperature risees, electric energy transmission power decline scheduling problem. The first annular groove and the second annular groove which correspond to each other are formed in the connecting portion, so that the drum spring can be more firmly installed. The elastic sheet can be matched with the groove to tightly hold the plug terminal so that the plug terminal cannot be easily separated.

Drawings

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.

Fig. 1 is a schematic structural view of a barrel terminal of the present invention.

Fig. 2 is a schematic view of the terminal body structure of the barrel terminal of the present invention.

Fig. 3 is a schematic structural diagram of a connecting portion of a barrel terminal according to the present invention.

Fig. 4 is a schematic structural diagram of a drum spring of a barrel terminal according to the present invention.

Fig. 5 is a schematic view illustrating the connection between the terminal body and the connecting portion of the barrel terminal of the present invention.

Fig. 6 is a schematic view illustrating the connection between the drum-type terminal connection portion and the drum spring according to the present invention.

Fig. 7 is a schematic view of a plug terminal structure of a terminal connection structure according to the present invention.

The figures are labeled as follows:

the terminal comprises a terminal body 1, a connecting part 2, a through groove 21, a first annular groove 23, a second annular groove 24, a drum spring 3, a spring sheet 31, a notch 32, a first baseband 33, a second baseband 34, a protection part 4, a plug terminal 5 and a circumferential groove 51.

Detailed Description

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

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.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

A barrel type terminal, as shown in fig. 1 to 6, comprising a terminal body 1, a connecting portion 2, a drum spring 3 and a shield portion 4; the drum spring 3 comprises at least two elastic sheets 31 protruding towards the axial direction; the connecting part 2 is cylindrical, one end of the connecting part is connected with the terminal body 1, and the other end of the connecting part is provided with at least two through grooves 21 along the axial direction; the drum spring 3 is sleeved on the connecting part 2, and at least part of the elastic sheet 31 penetrates through the through groove 21 and protrudes out of the inner wall of the connecting part 2; the protection part 4 is cylindrical and is sleeved on the periphery of the drum spring 3 in a matching manner. The utility model discloses a cylinder terminal, 1 inside at least unilateral open-ended cavities of terminal body, with to inserting the end terminal and carry out to inserting and be connected, realize electric switching on. One end of the terminal body 1 is used for connecting with a cable, the other end is connected with the connecting part 2, the connecting part 2 is provided with a through groove 21, and when the drum spring 3 is sleeved on the connecting part 2, the elastic sheet 31 on each drum spring 3 can pass through the corresponding through groove 21 and protrude out of the inner surface of the connecting part 2. At this time, the elastic piece 31 is elastic, and when the opposite terminal is inserted into the connection portion 2, the elastic piece 31 applies elastic force to the opposite terminal from a plurality of directions to clamp the opposite terminal, so that the opposite terminal is not easily removed from the connection portion 2. The utility model provides a safe and reliable removable female end terminal solves the problem that the junction wearing and tearing back became invalid but can not local change between the terminal, and enables the terminal of inserting each other and has bigger plug power big, and when can also preventing plug terminal, the terminal decentraction, the serious condition of contact department wearing and tearing appears. In a specific implementation, an internal thread may be provided inside the terminal body 1, and an external thread may be provided outside the connection portion 2, and both may be connected by a thread.

In some embodiments, the connecting portion 2 is integrally formed with the terminal body 1. That is to say, through groove 21 sets up at the tip of terminal body 1, and drum spring 3 directly overlaps and establish on terminal body 1, and integrated into one piece's advantage can reduce work step, reduce time cost.

In some embodiments, the drum spring 3 includes a first base band 33 and a second base band 34 disposed at two ends of the elastic piece 31, the connecting portion 2 is provided with a first annular groove 23 and a second annular groove 24, the first base band 33 is disposed in the first annular groove 23, and the second base band 34 is disposed in the second annular groove 24. The drum spring 3 is a conventional structure, and includes a first base band 33 and a second base band 34 at both ends and a resilient piece 31 in the middle. The first annular groove 23 and the second annular groove 24 which are corresponding to each other are arranged on the connecting part 2, so that the drum spring 3 can be positioned, the axial displacement between the drum spring and the connecting part 2 can be prevented, the drum spring 3 can be more firmly installed,

in some embodiments, the drum spring 3 has at least one axial indentation 32. The gap 32 can facilitate the drum spring 3 to open and be more easily sleeved on the connecting part 2. The plurality of notches 32 may be provided, that is, the drum spring 3 is divided into several parts and respectively disposed on the connecting portion 2, and the outside is fixed by the protecting portion 4.

In some embodiments, the protective part 4 is screwed or clamped on the outer wall of the connecting part 2. Specifically, an external thread may be disposed inside the protective portion 4, an internal thread may be disposed on the connecting portion 2, and the protective portion 4 may be connected to the connecting portion 2 through a thread. Or a clamping point is arranged on the connecting part 2, a clamping groove is arranged on the protection part 4, and the protection part 4 and the connecting part 2 are clamped through the clamping groove and the clamping point.

The utility model also provides a terminal connection structure, include as above a cylinder terminal and with the plug terminal 5 that cylinder terminal pegged graft, plug terminal 5 is the column, and have with the recess of shell fragment 31 joint. The male terminal 5, which is one of the above-mentioned male terminals, is generally cylindrical and can be inserted into the connecting portion 2 to form an electrical connection. The spring plate 31 can grasp the plug terminal 5 so that it cannot be easily removed. The number of the grooves can be multiple, and each groove corresponds to one spring sheet 31 individually, so that the plugging of the plugging terminal 5 and the connecting part 2 is completed.

In some embodiments, the groove is a circumferential groove 51 disposed circumferentially along the mating terminal 5. As shown in fig. 7, the circumferential groove 51 is a groove completely wound around the plug terminal 5. Specifically, the height of the elastic sheet 31 protruding from the inner wall of the connecting portion 2 is greater than the depth of the circumferential groove 51, so that the elastic sheet deforms only at the moment when the elastic sheet 31 is clamped into the circumferential groove 51. Meanwhile, the axial width of the elastic sheet protruding from the inner wall of the connecting part 2 is smaller than or equal to the width of the circumferential groove 51, so that the design is also to avoid that the elastic sheet 31 deforms and the plugging effect is influenced because the circumferential groove 51 applies extra force to the elastic sheet 31 after plugging. After complete insertion, the circumferential groove 51 and the elastic sheet 31 are matched with each other, so that the connection of the terminal is more stable, the elastic sheet can be protected, and the service life is prolonged.

In some embodiments, the mating force of the barrel terminal with the mating terminal 5 is 6N-350N. In order to verify the influence of the plugging force between the plug terminal 5 and the barrel terminal on the contact resistance between the plug terminal 5 and the barrel terminal and the plugging condition, the inventor selects the plug terminal 5 and the barrel terminal with the same shape and size, designs the plugging force between the plug terminal 5 and the barrel terminal into different plugging forces, and observes the contact resistance between the plug terminal 5 and the barrel terminal and the condition after multiple times of plugging. The results are shown in Table 1.

Table 1: influence of the plug-in force between different plug-in terminals and barrel-type terminals on contact resistance and plug-in condition

The contact resistance is detected by measuring the resistance at the contact position of the plug terminal 5 and the barrel terminal using a micro resistance meter, and reading the value on the micro resistance meter, and in this embodiment, the contact resistance is less than 50 μ Ω, which is an ideal value.

The test mode of the plug-in terminal 5 and the barrel terminal is that the plug-in terminal 5 and the barrel terminal are plugged 50 times, the times of dropping and incapability of plugging after plugging are observed, the dropping time requirement after plugging is less than 3 times, and the time requirement of incapability of plugging is less than 5 times.

As can be seen from table 1, when the insertion force between the insertion terminal 5 and the barrel terminal is less than 6N, the bonding force is too small, the contact resistance between the two terminals is higher than an ideal value, and the number of times of dropping after insertion exceeds 3 times, which is an unqualified state. When the mating force between the mating terminal 5 and the barrel terminal is larger than 350N, the number of times the mating terminal 5 and the barrel terminal cannot be plugged is larger than 5 times or more, and the mating force between the mating terminal 5 and the barrel terminal is set to 6N to 350N by the inventor.

In some embodiments, the groove surface is provided with a wear resistant coating. Through setting up wear-resisting cladding material, can prevent that the surface of recess from being worn and torn, the life of extension plug terminal 5.

Furthermore, the wear-resistant coating is made of one of gold, silver, nickel, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy.

The wear-resistant coating is used as a metal contact which needs to be plugged and unplugged frequently, a better wear-resistant metal is used as a material, the service life of the contact can be effectively prolonged, and the conductivity can be increased by using the metal coating.

In order to demonstrate the influence of different wear-resistant coating materials on the overall performance of the plug terminal, the inventor used the same barrel terminal and conducted a series of plugging times and corrosion resistance time tests on the plug terminal 5 sample pieces of the grooves of different wear-resistant coating materials. The results of the experiment are shown in table 2 below.

The following table 2 shows that the plugging times are obtained by respectively fixing the opposite plug terminal 5 and the barrel terminal on a test bench, simulating plugging by using a mechanical device, stopping to observe the damage condition of the wear-resistant coating on the surface of the opposite plug terminal 5 every time 100 times of plugging is performed, stopping the experiment if the wear-resistant coating is scratched and the material of the opposite plug terminal 5 is exposed, and recording the plugging times at that time. In this embodiment, the number of plugging times is not more than 8000.

Table 2: influence of different wear-resistant coating materials on plugging times of plug terminal

As can be seen from table 2 above, when the selected wear-resistant coating is made of gold, silver-antimony alloy, palladium-nickel alloy, graphite-silver, graphene-silver and silver-gold-zirconium alloy, the experimental result exceeds the standard value more, and the performance is more stable. When the selected wear-resistant coating is made of nickel, tin-lead alloy and zinc, the experimental result can meet the requirement, so that the inventor selects the wear-resistant coating to be made of one of gold, silver, nickel, tin-lead alloy, zinc, silver-antimony alloy, palladium-nickel alloy, graphite-silver, graphene-silver and silver-gold-zirconium alloy.

The plating layer can adopt methods such as electroplating, chemical plating, magnetron sputtering or vacuum plating and the like.

The electroplating method is a process of plating a thin layer of other metals or alloys on the surface of some metals by utilizing the electrolysis principle.

The chemical plating method is a deposition process for generating metal through controllable oxidation-reduction reaction under the catalytic action of the metal.

The magnetron sputtering method is characterized in that electrons spirally run near the surface of a target by utilizing the interaction of a magnetic field and an electric field, so that the probability of generating ions by the electrons colliding with argon is increased. The generated ions collide with the target surface under the action of the electric field so as to sputter the target material.

The vacuum plating method is to deposit various metal and non-metal films on the surface of the plastic part by distillation or sputtering under vacuum condition.

In some embodiments, the material of the terminal body 1 is tellurium copper alloy. The content of tellurium is 0.1% -5%.

The tellurium copper alloy can enable the terminal body 1 to have good conductivity and easy cutting performance, ensure the electrical performance and improve the processability, and meanwhile, the elasticity of the tellurium copper alloy is also excellent. Preferably, the tellurium content in the tellurium-copper alloy is 0.2% -1.2%.

The inventor selects 10 terminal bodies 1 with the same shape and the same expansion and contraction joint width for testing, wherein each terminal body 1 is tellurium-copper alloy, and the content of tellurium accounts for 0.05%, 0.1%, 0.2%, 1%, 1.2%, 1.8%, 3%, 5%, 6% and 7% respectively. As shown in Table 3, in the present example, the conductivity of the tellurium copper alloy is greater than 99% as the ideal value.

Table 3, effect of tellurium-copper alloys of different tellurium contents on conductivity.

Tellurium content

0.05％

0.1％

0.2％

1％

1.2％

1.8％

3％

5％

6％

7％

Electrical conductivity of

98.6％

99.1％

99.3％

99.6％

99.8％

99.5％

99.3％

99.1％

98.9％

98.7％

As is clear from Table 3, when the content ratio of tellurium is less than 0.1% or more than 5%, the conductivity is remarkably decreased and the desired value cannot be satisfied. When the content of tellurium accounts for more than or equal to 0.2 percent and less than or equal to 1.2 percent, the conductivity is the best, so the inventor selects tellurium copper alloy with 0.1 to 5 percent of tellurium content. Under the most ideal condition, 0.2-1.2% tellurium-copper alloy is selected.

In some embodiments, the material of the terminal body 1 is beryllium copper alloy, which provides the terminal body 1 with high hardness, elastic limit, fatigue limit, and wear resistance, and also has good corrosion resistance, thermal conductivity, and electrical conductivity, and does not generate sparks when being impacted. Preferably, the beryllium content in the material of the terminal body 1 is 0.05% -5%. The limitation of the content of beryllium in the terminal body 1 is found by the inventors through a plurality of experiments.

When the content of beryllium in the material of the terminal body 1 is less than 0.05%, sparks are likely to occur when an impact is applied because the material is close to pure copper. When the content of beryllium in the material of the terminal body 1 is more than 5%, the electrical conductivity of the beryllium copper alloy is inferior to that of a pure copper material, so that the resistance value of the terminal body 1 is not satisfactory. Therefore, the beryllium content in the material of the terminal body 1 is 0.05% to 5%. More preferably, the beryllium content in the material of the terminal body 1 is 0.1% to 3.5%.

In order to verify the influence of the content of beryllium in the material of the terminal body 1 on the resistance and the ignition condition of the terminal body 1, the inventor selects 10 terminal bodies 1 with the same shape for testing, wherein each terminal body 1 is beryllium-copper alloy, and the content of beryllium is 0.05%, 0.1%, 0.2%, 1%, 1.2%, 1.8%, 3%, 5%, 6% and 7% respectively. The test contents are the resistance and the sparking condition of the terminal body 1, and the test results are shown in table 4.

The method for testing the resistance of the terminal body 1 is to use a micro-resistance measuring instrument, place the measuring ends of the micro-resistance measuring instrument on the two ends of the terminal body 1, place the measuring ends at the same position every time, and then read the resistance reading on the micro-resistance measuring instrument. In this example, a resistance greater than 1m Ω is not acceptable.

The terminal body 1 is impacted with the opposite-inserting-end terminal by adopting the electrified terminal body 1, the state of the terminal body 1 under the working condition is simulated, the impact is observed for 1000 times, the number of times of the ignition condition is generated, and the terminal body is unqualified when the number of times of the ignition condition exceeds 3 times.

Table 4, effect of different beryllium contents on the resistance and sparking of the terminal body 1

As can be seen from table 4 above, when the content of beryllium in the material of the terminal body 1 is less than 0.05%, the number of sparking events exceeds 3 times when the terminal body 1 collides with the opposite-end terminal because the material is close to pure copper. When the content of beryllium in the material of the terminal body 1 is more than 5%, the electrical conductivity of the beryllium copper alloy is inferior to that of a pure copper material, so that the resistance value of the terminal body 1 is not satisfactory. Therefore, the beryllium content in the material of the terminal body 1 is 0.05% to 5%. Preferably, the content of beryllium in the material of the terminal body 1 is set to be preferably 0.1% to 3.5%, because the resistance and the sparking of the terminal body 1 are in a more preferable range when the content of beryllium in the material of the terminal body 1 is 0.1% to 3.5%.

In some embodiments, the pressure exerted by the spring 31 on the jack terminal 5 is 0.5N-188N. In order to verify the influence of the pressure exerted by the spring plate 31 on the plug terminal 5 on the plug strength between the spring plate 31 and the plug terminal 5, the inventor selects the same plug terminal 5 and different drum springs 3 for testing, and the elasticity exerted by the spring plate 31 of each drum spring 3 on the plug terminal 5 is different. After the plug terminal 5 is plugged with the barrel terminal, different forces are applied to pull out the plug terminal 5, if the plug terminal can be pulled out, the plug terminal is unqualified, and if the plug terminal can not be pulled out, the plug terminal 5 is qualified, if the plug terminal is continuously plugged for 10 times, scratches appear on the surface of the plug terminal 5, which indicates that the pressure is too high, and the plug terminal is also unqualified, and the results are shown in table 5.

Table 5: the effect of the pressure exerted by the spring plate 31 on the plug-in terminal 5 on the insertion/removal

As can be seen from the above table 5, when the pressure applied to the plug terminal 5 by the resilient piece 31 is less than 0.5N, the plug terminal 5 is easily pulled out due to the small pressure, and is not qualified. When the pressure applied by the spring plate 31 on the plug terminal 5 is greater than 188N, the plug terminal 5 is scratched after being continuously inserted and pulled for 10 times, and the material of the body of the plug terminal 5 is exposed. If the situation occurs in the actual use, the resistance is likely to increase, and accidents occur. Therefore, the pressure exerted on the plug terminal 5 by the elastic sheet 31 is preferably 0.5N-188N.

In some embodiments, the contact area between the spring piece 31 and the plug terminal 5 is 0.015mm ² -9mm ² . In order to verify the influence of the contact area between the spring piece 31 and the jack terminal 5 on the contact resistance between the spring piece 31 and the jack terminal 5, the inventor selects the same jack terminal 5 and different drum springs 3 for testing, and the contact area between the spring piece 31 on each drum spring 3 and the jack terminal 5 is different. The method for testing the resistance of the spring plate 31 and the plug terminal 5 is to use a micro-resistance measuring instrument, place the measuring ends of the micro-resistance measuring instrument on the spring plate 31 and the plug terminal 5 respectively, place the same position for each measurement, and then read the resistance reading on the micro-resistance measuring instrument. In this example, the resistance of more than 1m Ω was determined as fail, and the results are shown in table 6.

Table 6: influence of contact area of the spring plate 31 and the plug terminal 5 on contact resistance

As shown in table 6, when the contact area between the spring plate 31 and the mating terminal 5 is less than 0.015mm2, the contact resistance between the spring plate 31 and the mating terminal 5 is greater than 1m Ω, which is not good, and when the contact area between the spring plate 31 and the mating terminal 5 is greater than 9mm ² Later, the contact resistance has not been significantly reduced, and is greaterThe contact area of the spring plate 31 with the plug terminal 5 also increases the resistance of the plug terminal 5 during insertion and removal, so the inventor prefers that the contact area of the spring plate 31 with the plug terminal 5 is 0.015mm ² -9mm ² 。

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

Claims

1. A barrel terminal, characterized in that: comprises a terminal body (1), a connecting part (2), a drum spring (3) and a protective part (4);

the drum spring (3) comprises at least two elastic sheets (31) protruding towards the axial direction;

the connecting part (2) is cylindrical, one end of the connecting part is connected with the terminal body (1), and the other end of the connecting part is provided with at least two through grooves (21) along the axial direction;

the drum spring (3) is sleeved on the connecting part (2), and the elastic sheet (31) at least partially penetrates through the through groove (21) and protrudes out of the inner wall of the connecting part (2);

the protection part (4) is cylindrical and is sleeved on the periphery of the drum spring (3) in a matching manner.

2. A barrel terminal as defined in claim 1, wherein: the connecting part (2) and the terminal body (1) are integrally formed.

3. A barrel terminal as defined in claim 1, wherein: the drum spring (3) comprises a first base band (33) and a second base band (34) which are arranged at two ends of the elastic sheet (31), a first annular groove (23) and a second annular groove (24) are formed in the connecting portion (2), the first base band (33) is arranged in the first annular groove (23), and the second base band (34) is arranged in the second annular groove (24).

4. A barrel terminal as defined in claim 1, wherein: the drum spring (3) has at least one axial recess (32).

5. A barrel terminal as defined in claim 1, wherein: the protective part (4) is in threaded connection or clamped connection with the outer wall of the connecting part (2).

6. A barrel terminal as defined in claim 1, wherein: the terminal body (1) is made of copper or copper alloy.

7. A terminal connection structure characterized in that: comprising a barrel terminal according to any one of claims 1 to 6 and a mating terminal (5) mating with the barrel terminal, wherein the mating terminal (5) is cylindrical and has a groove for engaging with the spring (31).

8. A terminal connection structure according to claim 7, wherein: the groove is a circumferential groove (51) arranged along the circumference of the plug terminal (5).

9. A terminal connection structure according to claim 7, wherein: the insertion force of the barrel-type terminal and the insertion terminal (5) is 6N-350N.

10. A terminal connection structure according to claim 7, wherein: and the surface of the groove is provided with a wear-resistant coating.

11. A terminal connection structure according to claim 10, wherein: the wear-resistant coating is made of one of gold, silver, nickel, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy.

12. A terminal connection structure according to claim 7, wherein: the pressure applied on the plug terminal (5) by the spring piece (31) is 0.5N-188N.

13. A terminal connection structure according to claim 7, wherein: the nominal contact area of the spring sheet (31) and the plug terminal (5) is 0.015mm ² -9mm ² 。