JP5262042B2 - Terminal connection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the connection structure of a battery pack making specific work in a battery or a battery terminal side unnecessary, simultaneously satisfying positioning and fixing of a connection rod and prevention of rotation or damage of a terminal, and having high reliability. <P>SOLUTION: In the connection structure between terminals electrically connecting with a connection rod between terminals of a plurality of batteries having a positive terminal and a negative terminal projecting from an outer packaging in which a power generating element is housed, a flat part on the top surface of the terminal is brought into contact with a flat part of the connection rod, a projecting fitting part in the connecting rod is arranged at the outer edge of the terminal and fit to the side surface of the terminal. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a terminal structure of an assembled battery in which terminals of a plurality of batteries are connected.

Due to environmental problems such as air pollution and an increase in carbon dioxide, or the problem of depletion of oil and price increases, it is desired that electric vehicles such as electric vehicles, electric motorcycles, electric bicycles and senior cars be put to practical use at an early stage. Moreover, development of a high performance battery is desired for the spread of them.
In general, in order to satisfy the power required for driving an electric vehicle, the battery is mounted on the vehicle as a high voltage or high capacity assembled battery connected in series or in parallel. Therefore, in order to realize the widespread use of electric vehicles, it is essential to ensure the high reliability of the assembled battery. For this purpose, it is important to improve the connection method between the batteries.

  In order to connect a plurality of batteries and connect the terminals of adjacent batteries with a connecting rod, a method of fixing the connecting rod to the terminal with a bolt or nut or welding to the terminal is used. However, if the connection rod is not positioned and fixed properly, the connection rod may be misaligned or dropped during welding, welding may be defective, or the terminal may be rotated or damaged. There was a risk that the resistance would rise due to loosening. As described above, an assembled battery used for an electric vehicle or the like often has a high voltage for operating a motor or a high capacity to enable long-distance travel. If the batteries fall out and short-circuit between the batteries, it may lead to a serious accident. In addition, if the battery terminals are damaged during assembly of the battery pack, or if there is a defect in the welding position or weld strength, the entire battery pack is considered defective even if it is defective at one location. The structure is a very important design element not only for improving reliability but also for safety and cost. In the method of fixing the connecting rod to the terminal with a bolt or nut, the torque at the time of tightening is transmitted to the terminal, and there is a possibility that the vicinity of the terminal is damaged.

  Patent Document 1 does not use a connecting rod, but in order to prevent erroneous connection of the cable to the positive and negative terminals, a notch having a different shape is provided on the positive terminal and the negative terminal, and the cable end is attached. An invention is described in which holes are formed in the jig so as to fit into the respective cutout shapes. However, in this method, it is necessary to process the battery terminal side, and the bolt strength is reduced, so that the bolt may be damaged by the torque at the time of fastening.

  Patent Document 2 proposes a method in which a plurality of protrusions are provided on a terminal and mated with a connecting rod (see FIG. 5). However, with this method, in addition to the need to process the battery terminal side, the terminal shape is complicated and high processing accuracy is required, and the plus and minus terminals on the top and bottom of a long battery module are attached. Angle accuracy is also required. This is because the bus bar cannot be fitted when the angle between the plus terminal and the minus terminal is slightly shifted. Further, although a plurality of protrusions are provided, the protrusions that actually receive the torque at the time of bolt attachment are limited, and if the terminal dimensions are limited, there is a possibility that a sufficient anti-rotation function cannot be exhibited. In a battery mounted on a hybrid electric vehicle which is a kind of electric vehicle, heat generation due to large current charging / discharging is large, so the thinning of the battery is one development trend to improve heat dissipation, As the thickness of the terminal is reduced, the dimensions of the terminal are also limited, and as shown in Patent Document 2, there is a limit to the method of performing complicated processing on the terminal portion.

  Similar problems apply to the prior art disclosed in Patent Document 3. In Patent Document 3, in order to reduce the contact resistance between the terminal and the connecting rod, a screw hole and an annular receiving groove are formed on the top surface of the terminal, and a protrusion corresponding to this shape is also formed on the connecting rod side. A method has been proposed in which a fixing bolt is screwed into a screw hole after connection and fitting, and a method of receiving a groove on a terminal with limited dimensions is technically difficult or Since the strength of the terminal is reduced by providing the groove, there is a possibility that the receiving groove may be damaged due to vibration or the like when mounted on the vehicle. When the terminal shape is a bolt, the positioning and fixing of the connecting rod are relatively easy, but the rotation and damage of the terminal are important problems. Note that the invention described in Patent Document 3 cannot prevent the torque at the time of tightening from being transmitted to the terminal.

  For example, in Patent Document 4, a rib or an anti-rotation member is provided in the battery to prevent rotation of the terminal as means for preventing the torque at the time of tightening from being transmitted to the terminal and preventing the terminal from rotating together. In Patent Document 5, a terminal is fixed with a case lid to prevent rotation. However, in any case, it is necessary to process the battery side, the number of parts increases, and it can be said that this is an undesirable solution from the viewpoint of cost and reliability.

In Patent Document 6, a seating surface that fits with a terminal is provided on the hermetic packing to prevent rotation. However, it is not preferable from the viewpoint of reliability to apply rotational torque directly to a resin component that maintains hermeticity. . On the other hand, Patent Document 7 and the like propose a method in which terminals of each battery are fitted together with an end plate of the assembled battery to prevent rotation, and a connection rod is embedded and positioned in the end plate. In addition to increasing the number of parts with complicated shapes even with this method, the terminal and end plate will not be properly fitted and rotation will be sufficient unless the terminal mounting angle and battery height are accurately aligned. The problem was that the prevention function could not be obtained.
JP 2001-93510 A JP 2001-185103 A JP-A-9-219186 JP-A-9-213303 JP 2004-200024 A JP 2001-357833 A Japanese Patent No. 3774977

  The present invention has been invented to cope with such circumstances, and does not require any special processing on the battery or battery terminal side, and satisfies the positioning and fixing of the connecting rod and the prevention of rotation and damage of the terminal at the same time. An object of the present invention is to provide a highly reliable assembled battery connection structure.

In order to solve the above-described problem, the inter-terminal connection structure according to the present invention provides a connection rod between terminals of a plurality of batteries each having a positive electrode terminal and a negative electrode terminal protruding from an exterior body housing a power generation element. The inter-terminal connection structure is electrically connected using the flat portion provided on the upper surface of the terminal and the flat portion of the connecting rod, and is fitted to the edge portion of the terminal. an outer edge of said projecting engaging portion provided on the connection rod terminals, and is arranged so as to face between the batteries mutually least adjacent terminals, characterized in that fitted to the side surface of the terminal.

  According to the present invention, since the connection rod is fitted to the terminal and the position is fixed, the connection rod does not move or drop due to the stress applied to the connection rod during bolt tightening, nut tightening, or welding. The occurrence rate of connection failure can be reduced. Further, the reliability against various mechanical stresses applied to the terminal portion during use of the assembled battery is improved. Since it fits in the edge part of a terminal, it can receive a torque in a large area and reliability improves. Moreover, since the space | interval of an adjacent battery is prescribed | regulated by fitting with a connecting rod and a terminal, the advantage that the dimensional accuracy and cooling performance of an assembled battery improve is also acquired.

  1 to 3 show an embodiment of the present invention, which is an assembly perspective view of a connecting battery 4a according to the present invention and an assembled battery in which two connecting batteries 4 are attached using the connecting battery 4a. Each square battery is formed by sealing the opening of the outer package 1 in which the power generation element is accommodated by the cover plate 2 to which the positive electrode terminal 3a and the negative electrode terminal 3b are attached. In each adjacent battery, the connection rod 4a and the terminals 3a and 3b are in contact with each flat portion, and the protruding connection rod fitting portion 4b provided on the connection rod 4a and the side surfaces of the terminals 3a and 3b are fitted. Yes.

  In the embodiment of FIG. 1, after fitting the terminal and the connecting rod, the terminal and the connecting rod are fixed by welding the upper portion of the connecting rod.

  FIG. 2 shows an embodiment in which the terminals 3a and 3b have bolt portions, and the bolt portions protrude further upward from a flat portion provided on the upper surface of the terminal. FIG. 3 shows the terminals 3a and 3b having a nut shape. Example of the case. When the terminal shape is a bolt 5b or a nut 5a, rotational torque is applied to the terminals 3a, 3b, but in this embodiment, the terminals 3a, 3b are fixed by a plurality of fitting portions, and the terminals 3a, 3b of the adjacent batteries Since the torque can be distributed to 3b, the terminals 3a and 3b are difficult to rotate.

  As described above, according to the present invention, there is little risk that the position of the connecting rod 4a is shifted or dropped due to stress such as pressurization, vibration or heat during welding. Also, the distance between the batteries is kept constant.

  In general, the terminals and connecting rods are made of thick plate-like or block-like metal, so that the strength is high. Therefore, the anti-rotation function is higher than the design in which the resin component is subjected to torque. In addition, since it is not necessary to make the terminal shape complicated, low cost, high reliability, and high versatility. For example, even for existing assembled batteries, the shape of the connection rod is only changed according to the terminal shape. There is an advantage that the above-mentioned effect can be obtained. Since it has a simple structure, there is an advantage that it can be easily applied even when there are restrictions on the dimensions and shape of the terminals.

  Next, the prior art as a comparative example will be described. FIG. 4 is an assembly perspective view of an example of a conventional connecting rod 4a and a battery to which the connecting rod 4a is attached. As shown in FIG. 4, the connecting rod 4a and the terminals 3a, 3b are in contact with each flat portion, but since there is no fitting portion that suppresses displacement and rotation prevention, the connecting rod 4a is stressed by welding. The connection position may not be stable due to the movement of 4a, or the connection rod 4a may fall off from the terminals 3a and 3b. FIG. 5 is also an assembly perspective view of an example of a conventional connecting rod 4a and a battery to which the connecting rod 4a is attached. When the nut 5a is fastened, the connecting rod 4a does not have a function of preventing the terminals 3a and 3b from rotating. There is a possibility that the terminals 3a and 3b are freely rotated by the torque of.

  Next, the form of fitting between the connecting rod and the terminal will be described. 6 to 9 show the combination of the connecting rod 4a and the terminals 3a and 3b according to the present invention, and FIGS. 10 to 11 show the prior art. As shown in FIGS. 6 to 9, the fitting between the connection rod 4a and the terminals 3a and 3b is made so that the projections of the connection rod 4a run along the side surfaces of the terminals 3a and 3b. The effect of the present invention becomes stronger as the fitting area is larger, but the effect can be obtained even in a design in which the fitting is performed with a part of the side surfaces of the terminals 3a and 3b as shown in FIG. The shape is not limited as long as the purpose can be achieved.

It is an assembled battery perspective view which shows the connection structure between terminals which concerns on an Example. It is an assembled battery perspective view which shows the connection structure between terminals which concerns on an Example. It is an assembled battery perspective view which shows the connection structure between terminals which concerns on an Example. It is an assembled battery perspective view which shows the connection structure between terminals which concerns on a comparative example. It is an assembled battery perspective view which shows the connection structure between terminals which concerns on a comparative example. It is a perspective view which shows the connecting rod which concerns on an Example. It is a perspective view which shows the connecting rod which concerns on an Example. It is a perspective view which shows the connecting rod which concerns on an Example. It is a perspective view which shows the connecting rod which concerns on an Example. It is a perspective view which shows the connecting rod which concerns on a comparative example. It is a perspective view which shows the connecting rod which concerns on a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exterior body 2 Cover plate 3a Positive electrode terminal 3b Negative electrode terminal 4a Connection rod 4b Connection rod fitting part 5a Nut 5b Bolt

Claims (1)

A terminal-to-terminal connection structure for electrically connecting terminals of a plurality of batteries having a positive electrode terminal and a negative electrode terminal protruding from an exterior body containing a power generation element using a connecting rod , the upper surface of the terminal A flat portion provided on the connecting rod and a flat portion of the connecting rod, and a projecting fitting portion provided on the connecting rod so as to be fitted to the edge portion of the terminal on the outer edge of the terminal , and , it is arranged so as to face between the batteries mutually least adjacent terminals, the terminals, characterized in that fitted to the side surface of the terminal connection structure.

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