Patent Publication Number: US-2022224036-A1

Title: Connection terminal and power supply device

Description:
RELATED APPLICATION INFORMATION 
     This application claims the benefit under 35 U. S.C. § 119(a) of Chinese Patent Application No. CN 202110048687.6, filed on Jan. 14, 2021, which application is incorporated herein by reference in its entirety. 
     BACKGROUND 
     A battery pack is widely used in an electric tool to provide power for the electric tool. A battery connection terminal is disposed on the electric tool, a tool connection terminal is disposed on a battery pack, and when the battery pack is connected to the electric tool, the battery connection terminal and the tool connection terminal are plugged together to conduct power. 
     In the related art, the tool connection terminal is in contact with the battery connection terminal through two or more contact points, and the contact area is relatively small, so that the voltage drop of the battery path is large, the contact resistance is large, and thus the heating is serious when a large current is passed. In addition, the relatively large vibration will lead to single point contact or no point contact, which may easily cause sparking, affect the coating of the battery connection terminal, and cause the contact resistance to deteriorate. 
     SUMMARY 
     In one example, a connection terminal includes a body portion including a first end disposed on a power supply device and a second end opposite to the first end; two connection pieces, wherein an inner clamping space for clamping an electrode piece is formed between the two connection pieces; and a support portion supporting the two connection pieces and disposed at the second end of the body portion. The support portion connects the two connection pieces and the body portion, an inner side surface of each of the two connection pieces includes a contact surface for connecting with the electrode piece, and the contact surface extends along a first plane so that the contact surface is capable of being in surface contact with the electrode piece. 
     In one example, the support portion includes at least one support arm, and the at least one support arm abuts outer side surfaces of the two connection pieces. 
     In one example, the support portion is formed with a plurality of support arms, and the plurality of support arms abut the outer side surfaces of the two connection pieces so as to form a multi-point support for the two connection pieces. 
     In one example, five support arms are provided for each of the two connection pieces, one of the five support arms abuts a middle part of the each of the two connection pieces, and four of the five support arms abut four corners of the each of the two connection pieces. 
     In one example, the two connection pieces are symmetrical about a second plane, and the contact surface is gradually away from the second plane along an insertion direction of the electrode piece. 
     In one example, the two connection pieces are symmetrical about a second plane, and an included angle A between the first plane and the second plane is about 1 degree. 
     In one example, each of the two connection pieces includes a connection portion and a contact portion, the connection portion extends and bends relative to the contact portion, the connection portion is connected to the support portion, the contact portion is provided with the contact surface, and the inner clamping space is formed between two contact surfaces. 
     In one example, a bell-mouth structure is formed between two connection portions and the bell-mouth structure gradually increases along a direction away from the inner clamping space. 
     In one example, a notch is provided at an intersection of the connection portion and the support portion, and the notch extends toward the inner clamping space. 
     In one example, the body portion, the support portion, and the two connection pieces are integrally formed. 
     In one example, the connection terminal further including a heat sink, wherein the heat sink is connected to the body portion and extends toward a direction away from the support portion. 
     In one example, the support portion includes a main body connecting the body portion and the two connection pieces and a support arm for abutting an outer side surface of the two connection pieces. 
     In one example, each of the two connection pieces includes a connection portion and a contact portion, the connection portion extends and bends relative to the contact portion, the connection portion is connected to the support portion, the contact portion is provided with the contact surface, the inner clamping space is formed between two contact surfaces, and the support arm abuts the contact portion. 
     In one example, the support portion includes a plurality of support arms for abutting the contact portion. 
     In one example, a power supply device includes a housing and a connection terminal. The connection terminal includes: a body portion including a first end disposed on the power supply device and a second end opposite to the first end; a first connection piece and a second connection piece, an inner clamping space for clamping an electrode piece being formed between the first connection piece and the second connection piece; and a support portion supporting the first connection piece and the second connection piece. The inner side surface of the first connection piece includes a first contact surface for connecting with the electrode piece, the inner side surface of the second connection piece includes a second contact surface for connecting with the electrode piece, and the first contact surface extends along a first plane so that the first contact surface is capable of being in surface contact with the electrode piece. 
     The beneficial effects of the present disclosure are described below. 
     According to the connection terminal provided by the present disclosure, the support portion is connected to the body portion to support the two connection pieces; the two connection pieces bend toward each other so that the connections pieces have certain resilience; the inner clamping space is formed between the two connection pieces for clamping the electrode piece, and the inner side surfaces of the two connection pieces are formed as planes to enable the electrode piece to be in surface contact with each of the two connection pieces, so that the contact area between the connection terminal and the electrode piece is increased, the contact resistance is reduced, and thereby the problem of heating of the battery pack is ameliorated; at the same time, the poor contact caused by the contact force and vibration is improved, the influence caused by the vibration is further reduced, and the connection is more stable. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a structural view of a connection terminal according to example one of the present disclosure; 
         FIG. 2  is a front view of the connection terminal according to example one of the present disclosure; 
         FIG. 3  is a structural view of a connection terminal according to example two of the present disclosure; 
         FIG. 4  is a front view of the connection terminal according to example two of the present disclosure; 
         FIG. 5  is a structural view of a power supply device according to an example of the present disclosure; and 
         FIG. 6  is an enlarged view of a partial structure of the power supply device of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     Examples in accordance with the present disclosure are described in detail hereinafter. Examples are illustrated in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions. The examples are intended to explain the present disclosure and are not to be construed as limiting the present disclosure. 
     In the description of the present disclosure, unless otherwise expressly specified and limited, the term “connected to each other”, “connected”, or “secured” is to be construed in a broad sense, for example, as securely connected, detachably connected or integrated; mechanically connected or electrically connected; directly connected to each other or indirectly connected to each other via an intermediary; or internally connected between two components or interaction relations between two components. For those of ordinary skill in the art, specific meanings of the preceding terms in the present disclosure may be understood based on specific situations. 
     In the present disclosure, unless otherwise expressly specified and limited, when a first feature is described as “above” or “below” a second feature, the first feature and the second feature may be in direct contact or be in contact via another feature between the two features. Moreover, when the first feature is described as “on”, “above”, or “over” the second feature, the first feature is right on, above, or over the second feature or the first feature is obliquely on, above, or over the second feature, or the first feature is simply at a higher level than the second feature. When the first feature is described as “under”, “below”, or “underneath” the second feature, the first feature is right under, below, or underneath the second feature or the first feature is obliquely under, below, or underneath the second feature, or the first feature is simply at a lower level than the second feature. 
     Technical solutions of the present disclosure are further described hereinafter in conjunction with the drawings and the examples. 
     Referring to  FIGS. 1 to 2 , the example of the present disclosure provides a connection terminal  10 , and the connection terminal  10  may be an electrode. The connection terminal  10  includes a body portion  11 , a support portion  12 , and two connection pieces  13 . The two connection pieces  13  are specifically a first connection piece  13   a  and a second connection piece  13   b . A first end  11   a  of the body portion  11  is disposed on a battery pack or a power tool, a second end  11   b  of the body portion  11  is connected to a first end  12   a  of the support portion  12 , and the two connection pieces  13   a ,  13   b  are disposed on a second end  12   b  of the support portion  12  facing away from the body portion  11 . The two connection pieces  13   a ,  13   b  bend toward each other, an inner clamping space  135  is formed between the two connection pieces  13   a ,  13   b  for clamping an electrode piece  40 , and inner side surfaces  130  of the two connection pieces  13   a ,  13   b  are formed as planes to enable the electrode piece  40  to be in surface contact with each of the two connection pieces  13   a ,  13   b . Each of the inner side surfaces  130  comprises a contact surface  130   a  for connecting the electrode piece  40 , the contact surface  130   a  is a plane extending along a first plane n so that the each of the two connection pieces  13   a ,  13   b  is in surface contact with the electrode piece  40 . 
     Since the connection pieces  13   a ,  13   b  are in surface contact with the electrode piece  40 , the contact area between the connection terminal  10  and the electrode piece  40  can be increased to reduce the contact resistance and thereby ameliorate the problem of heating of the battery pack or the power tool. At the same time, the poor contact caused by the contact force and vibration can be improved, so that the influence caused by the vibration can be further reduced and the connection can be more stable. 
     In the example, the body portion  11  is formed in a U-shape, the support portion  12  is disposed on opposite sides of the body portion  11 , the connection pieces  13   a ,  13   b  are disposed on the end portion of the support portion  12 , and the two connection pieces  13   a ,  13   b  bend toward each other. 
     The body portion  11 , the support portion  12 , and the connection pieces  13   a ,  13   b  are integrally formed to facilitate processing and production and ensure the structural strength. The connection between the support portion  12  and each connection piece  13  bends in an arc shape, so that the connection pieces  13   a ,  13   b  have a certain resilience. 
     The support portion  12  includes a main body  122  and multiple support arms  12  and the multiple support arms  121  extend from the main body  122  to the connection pieces  13   a ,  13   b , so multiple support arms  121  abut outer side surfaces  134  of the connection pieces  13   a ,  13   b . The outer side surfaces  134  is opposite to the inner side surfaces  130 . When the electrode piece  40  is inserted into the inner clamping space  135 , the inner side surfaces  130  of the connection pieces  13   a ,  13   b  abut the electrode piece  40 , and the outer side surfaces  134  of the connection pieces  13   a ,  13   b  abut the support arms  121 , so that the inner sides and outer side surfaces of the connection pieces  13   a ,  13   b  are supported, and the plugging stability of the electrode piece  40  is ensured. 
     Specifically, the support arms  121  bend toward the connection pieces  13   a ,  13   b  relative to the support portion  12 , so as to abut the connection pieces  13   a ,  13   b.    
     Support arms  121  on the outer side  134  of one of the two connection pieces  13   a ,  13   b  are arranged in the same form as support arms  121  on the outer side  134  of the other one of the two connection pieces  13   a ,  13   b , so that the clamping forces of the two connection pieces  13   a ,  13   b  to the electrode piece are consistent and uniform. 
     In the example, five support arms  121  are provided for each connection piece  13 , one of the five support arms  121  abuts a middle part of each connection piece  13 , and four of the five support arms  121  abut four corners of the each connection piece  13 , so that each connection piece  13  is uniformly stressed as a whole. 
     Specifically, each connection piece  13  includes a connection portion  131  and a contact portion  132 , the connection portion  131  extends and bends relative to the contact portion  132 , the connection portion  131  is connected to the support portion  12 , and the inner clamping space  135  is formed between two contact portions  132 . The inner side of each of the two contact portions  132  is provided the contact surface  130   a . The connection portion  131  serves as a transition so that the two contact portions  132  can approach each other. Five support arms  121  abut the outer side of the contact portion  132 . 
     A bell-mouth structure  136  is formed between the two connection portions  131 , and the bell-mouth structure  136  gradually increases along a direction away from the inner clamping space  135 , so as to facilitate the insertion of the electrode piece  40  into the inner clamping space  135 . 
     A notch  133  is provided at a junction of the connection portion  131  and the support portion  12 , and the notch  133  extends toward the inner clamping space. The notch  133  is provided so that the resilience of the connection between the connection pieces  13   a ,  13   b  and the support portion  12  is enhanced and a certain space is provided for the deformation of the connection pieces  13   a ,  13   b.    
     The inner clamping space  135  is formed between the contact surface  130   a  of the two connection pieces  13   a ,  13   b , and the connection position between the connection portion  131  and the contact portion  132  is an entrance end  135   a  of the inner clamping space  135 . If the inner side surfaces of the two connection pieces are parallel and thus the inner clamping space is rectangular, then, when the electrode piece  40  is inserted into the inner clamping space, the contact portion tends to tilt due to the leverage effect, resulting in that opening distances of two ends of the inner clamping space are different and the connection pieces cannot be in full contact with the electrode piece  40 . 
     In the example, the shape of the inner clamping space  135  is an isosceles trapezoid, and along an insertion direction of the electrode piece  40 , the inner clamping space  135  gradually increases. 
     Specifically, the first connection piece  13   a  is symmetrical to the second connection piece  13   b  about a second plane m, an included angle between each of the contact surface  130   a  of the two connection pieces  13   a ,  13   b  and the second plane m is a set angle, and the contact surface  130   a  are gradually away from the second plane m along the insertion direction of the electrode piece  40 . The contact surface  130   a  is inclined to the second plane m. 
     In  FIG. 2 , the second plane is represented by m, the first plane n is an extended plane of the contact surface  130   a , and the included angle between the first plane n and the second plane m is represented by A. 
     When the electrode piece  40  is inserted into the inner clamping space  135 , the electrode piece  40  first squeezes the connection position between the connection portion  131  and the contact portion  132 . Since the contact portion  132  is pre-tilted outward, the problem can be solved of the difference in the opening distances of the two ends of the inner clamping space  135  caused by the leverage effect, so that the connection pieces  13   a ,  13   b  can be in full contact with the electrode piece  40  to ensure the insertion stability of the electrode piece  40 . 
     The angle of the included angle A may be set according to actual conditions and is not limited here. In the example, the included angle is about 1 degree. 
       FIGS. 3 and 4  show another example, in which the same or corresponding parts as in the preceding example are denoted by the corresponding reference numerals. For brevity, only the difference between the example of  FIGS. 3 and 4  and the preceding example is described below. The difference is that the connection terminal  10  further includes a heat sink  21 . The heat sink  21  is connected to the body portion  11  and extends toward a direction away from the support portion  12 . The heat sink  21  is provided so that the heat capacity of the connection terminal  10  is increased, the contact area between the connection terminal  10  and the air is also increased, and thereby the heat dissipation area is increased. Therefore, heat accumulation is avoided, so that the impact of a large current on the performance of the battery pack is reduced. 
     Specifically, one side of the body portion  11  is provided with an extension portion  111 , the extension portion  111  extends in the direction away from the support portion  12 , and the heat sink  21  is connected to the extension portion  111  to adapt to the mounting space of the connection terminal  10 . 
     The shape of the heat sink  21  may be set according to actual requirements. In the example, the heat sink  21  includes a straight portion and an arc-shaped portion, which increase the heat dissipation area of the heat sink  21  and also adapt to the mounting space of the heat sink  21 . 
     Referring to  FIG. 5 , the example of the present disclosure further provides a power supply device  31 , specifically providing a battery pack, which includes a housing  31   a  and the connection terminal  10  of any one of the preceding examples. 
     Referring to  FIGS. 5 to 6 , a mounting groove is provided in the housing  31   a  of the battery pack, and the connection terminal  10  is inserted into the mounting groove. A limit groove is provided in the housing, and the heat sink  21  is inserted into the limit groove. The limit groove is provided along the inner wall of the housing  31   a  to reduce space occupation. 
     The preceding examples illustrate only the basic principles and features of the present disclosure. The present disclosure is not limited by the preceding examples. Various modifications and variations made without departing from the spirit and scope of the present disclosure fall within the scope of the present disclosure. The scope of the present disclosure is defined by the appended claims and their equivalents.