JPH03285265A - Thermal cell - Google Patents

Abstract

PURPOSE:To shorten connecting work, reduce defective occurrence rate, and improve reliability of long-time discharge by making output terminals mounted on a cell cap into a pipe form, making each top end of internal lead wires into the core form of the pipe, and using laser welding. CONSTITUTION:Each constituting part is inserted in a cell case 6. When a cell cap 1 is then inserted and fitted to the cell case 6, improved internal lead wires 3a, 3b are simultaneously inserted to output terminals 2a, 2b. The improved internal lead wires 3a, 3b are welded to the output terminals 2a, 2b on the end surface of the cell outer part by YAG laser, and the cell can 1 is successively welded to the cell case 6.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the improvement and welding of output terminals and internal leads in thermal batteries.

BACKGROUND TECHNOLOGY A thermal battery is inactive at room temperature, but becomes active when heated to a high temperature and can supply power to the outside world, and is a type of storage battery. Therefore, even after storage for 5 to 10 years or more, the battery characteristics remain the same as they were immediately after manufacture, so they are used as an emergency power source. In addition, since it is operated at high temperatures, electrode reactions progress easily and there is little polarization, so it has excellent large current discharge characteristics, and when desired, it can instantly extract electric power by inputting an electromotive signal.

Manufacturing such a thermal battery is complicated and requires a large number of man-hours. Particularly difficult is the connection between the internal lead wire and the output terminal of the battery lid during the battery assembly process. This was a very difficult manual process because the area around the connection was covered with insulation material.

The configuration will be explained below.

FIG. 3 is a diagram showing the structure of the T-cell cover and internal lead wire of a conventional thermal battery. In the figure, 1 is the battery cover, 19a.

Reference numeral 19b denotes a pair of output terminals made of a hermetic seal, and the inner bottle side thereof and the inner lead wires of 20a and 20b are electrically connected by spot welding. 5 is an output terminal for an igniter, 4 is an igniter, and 6 is a battery case.

Another conventional example is one in which the welded portion is soldered. Figure 4 shows its structure.

21a and 21b are made of a hermetic seal, and the internal pin side is soldered to form a pair of output terminals. It is in a state of conjugation. Other parts are the same as those shown in Fig. 3.

Problems to be Solved by the Invention However, in the configuration shown in FIG.
It is very small, about 2 m2, and there are insulation materials and stacks nearby, so the work space is narrow and difficult. Furthermore, since welding must be performed before the battery cover and battery case are fitted together, there is a risk that the igniter and the battery will burn due to sparks generated during welding. In addition, in a configuration that uses solder to join as shown in Figure 4, during long-term discharge, the solder parts also become hot and the solder melts, potentially causing the joint to come off, reducing the reliability of the discharge. However, there was a problem with the problem of a decline in performance.

The present invention solves the conventional problems as described above.
It is an object of the present invention to provide a thermal battery in which the connection work between an output terminal and an internal lead wire is easy and safe, and the reliability does not deteriorate even during long-time discharge.

Means for Solving the Problems In order to achieve this object, in the present invention, the output terminal of the battery cover is made into a pipe shape, and the tip of the internal lead wire is made into the shape of a pipe core, and after being inserted into the pipe-shaped output terminal. The outer end surface of the pipe-shaped output terminal and the inner lead wire in contact with each other is laser welded, for example, YAG laser welding, to perform sealing and electrical connection.

Function: With this configuration, the output terminal and the internal lead wire can be connected on the outside of the battery cover, making it extremely easy to connect the output terminal and the internal lead wire. In addition, YAG lasers can perform fine welding work, and because they do not emit sparks or raise the temperature around the welding area, they do not adversely affect surrounding parts. Furthermore, unlike soldering, it does not come off due to heat, so voltage fluctuations do not occur, and reliability does not deteriorate during long-term discharge.

Embodiments Below, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an output terminal and an internal lead wire in an embodiment of the present invention. In Figure 1, 1 is a battery cover, 2a
, 2b is a pair of pipe-shaped output terminals made of a hermetic seal, 3a and 3b are a pair of internal lead wires whose tips are shaped like pipe cores, 4 is an igniter, 5 is an igniter terminal, 6 is a battery case, A is the welding surface.

FIG. 2 shows a long-time operation type laminated thermal battery using the battery cover and internal lead wires configured as shown in FIG. 1.

In the figure, numeral 10 is a unit cell, which is a power generation element consisting of a negative electrode layer 7, an electrolyte layer 8, and a positive electrode layer 9. Reference numeral 11 denotes heat generating agent pellets for heating the unit cells 10, which are stacked alternately with the unit cells 10 to form a stack portion 12. 13 is a heat storage agent that keeps the stack part 12 warm. Also stack 12
The perimeter is 16 bottom insulation, 170 cylindrical insulation and 1
The lid is covered with heat insulating material No. 8 to suppress heat radiation. Furthermore, when the battery is started, a heat pad 14 that ignites and burns in response to fire from the igniter 4, and a fuse cord 15 for igniting the exothermic pellets in each layer are provided inside the battery. A pair of internal lead wires 3a and 3b extend from the stack portion 12, and are connected to pipe-shaped output terminals 2a and 2b.

A feature of this configuration is an improved internal lead wire 3a.

3b and the output terminals 2a, 2b can be connected simultaneously with the fitting of the battery cover 1 and the battery case 6, and welding can be performed outside the battery.

The work procedure of this example is as follows: (1) Insert each component into the battery case 6.

(2) When inserting and fitting the battery cover 1 into the battery case 6, the improved internal lead wires 3a and 3b are connected to the output terminal 2.
Insert into a and 2b.

(3) The improved internal lead wires 3a, 3b and the output terminals 2a, 2b are welded with a YAG laser on the external end face of the battery, and then the battery cover 1 and battery case 6 are also welded. According to this, the improved internal lead wires 3a, 3b and the output terminals 2a, 2b can be welded outside the battery, so the work space is wide and easy, and sparks during welding do not enter the battery, making it safe. Although this welded part is a very small part, it is made possible by using YAG laser welding, which allows the welding part to be narrowed down. Furthermore, since the heat generated during welding can be suppressed to a minimum, there is no adverse effect of heat on the hermetic seal portion, etc. Furthermore, battery M1
Since the battery case 6 and the battery case 6 can be welded together, the workability is good, and in this example, the work time for this process can be reduced to one-fourth of the conventional time.

As described above, according to this embodiment, by making the output terminal into a pipe shape and making the internal lead wire into the core shape of this pipe, the work of joining the output terminal and the internal lead wire can be greatly shortened, and each part can be easily connected. There is no need to worry about the harmful effects of heat or the risk of burning the battery during work. Furthermore, even when this battery was discharged for a long time, the welded joints did not come off due to heat from inside the battery (and stable and reliable discharge performance could be obtained).

Effects of the Invention The present invention makes the output terminal attached to the battery cover pipe-shaped, the tip of the internal lead wire is shaped like the core of the pipe, and uses laser welding to facilitate the joining work between the internal lead wire and the output terminal. It can be shortened, further reducing the defect rate,
A thermal battery that can achieve the effect of improving long-term discharge reliability can be realized.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the output terminal and internal lead wire in an embodiment of the present invention, and Fig. 2 is a cross-sectional view of a long-time operation type laminated thermal battery using the battery lid and internal lead wire configured as shown in Fig. 1. , FIG. 3 is a diagram showing the structure of the battery lid and internal lead wire of a conventional thermal battery, and FIG. 4 is a diagram showing the structure of the battery lid and internal lead wire of a conventional thermal battery. 19a...+ side conventional output terminal, 19b...
... - side conventional output terminal, 20a ... child side conventional internal lead, 20b ... - conventional internal lead, 2
1a...! \Example side conventional output terminal 21b
・・・・・・）・Conventional output terminal for driver, 22a・・
...Conventional internal lead on + side for soldering, 221)...
...For soldering - example conventional internal lead.

Claims (1)

[Claims] In a thermal battery that has a heat insulating material between a stack part in which unit cells and exothermic pellets are alternately stacked and a battery lid, the tip of the output terminal is connected to a pipe-shaped output terminal having a through hole attached to the battery lid. Insert each of the internal lead wires forming the positive and negative electrodes of the stack, which are core-shaped without a through hole that can be inserted into the hollow of the terminal pipe, and align the terminal end surface on the outside of the battery lid with the end surface of the internal lead wire. A thermal battery characterized by laser welding.