JP3276768B2 - Battery pack - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack having electronic components and a battery built in a case.

[0002]

2. Description of the Related Art In a battery pack, a plurality of batteries can be housed in a case to obtain high output or high energy. In many cases, the battery pack case is divided into two parts so that the battery can be stored and easily assembled. The battery pack is assembled by storing the battery in one case, covering the other case, and combining the two cases. A secondary battery such as a nickel cadmium battery having a higher output and higher energy than a dry battery is often used as a battery having a built-in battery pack.
Since the secondary battery can be used repeatedly by charging, there is no need to replace the stored secondary battery. Therefore, the two-part case of the battery pack is firmly bonded without being divided from each other. Ultrasonic welding has been used for this bonding method.

[0003]

In recent years, with the miniaturization and high performance of various electric and electronic devices, the capacity of battery packs used as a power source for these devices has been increasing. Output has been required. As a result, high capacity nickel cadmium batteries, nickel hydride batteries, lithium ion batteries, and the like have been developed. or,
In the use of various devices, it is required that the battery can be operated for a long time using a battery pack as a power source, and that the charging time can be shortened so that the device can be used immediately and quickly even if the battery capacity decreases and the device cannot be driven. Have been. As described above, the use conditions of batteries are becoming severe, and protection circuits for controlling the charge and discharge of batteries to withstand these use conditions and prevent deterioration over a long period of time have been provided. ing. The protection circuit built in the battery pack has circuit components mounted on a printed circuit board and is housed in a case together with the battery. However, a battery pack having a built-in printed circuit board has a disadvantage that ultrasonic welding cannot be used as a bonding means for the two-part case.
This is because ultrasonic welding generates vibration during welding, and this vibration may cause circuit components mounted on the printed circuit board to be dropped or soldered to be removed.

[0004] The above disadvantages can be solved by bonding the case with an adhesive instead of ultrasonic welding. This is because the adhesive can be bonded without vibrating the case. However, when an adhesive is used, it is difficult to firmly join the cases as in ultrasonic welding. In particular, in the case where the peripheral wall to be bonded is formed to be thin, the bonding area cannot be increased, and it is difficult to securely connect. Further, the method of bonding the peripheral wall with an adhesive has a drawback that it is difficult to apply the adhesive uniformly to the joint surface and bond the whole with the same strength.

The present invention has been developed to solve these drawbacks of the conventional battery pack. An important object of the present invention is to make it possible to easily and easily divide a molded case. Another object of the present invention is to provide a battery pack that can be securely bonded and firmly bonded.

[0006]

The battery pack of the present invention comprises:
The following structure is provided to achieve the above object. The battery pack 3 has an upper case 1 and a lower case 2 which are separately formed and joined together at a joint surface, and has a battery 3 and electronic components built therein.

In this specification, the upper case and the lower case are determined up and down in the drawing, and the case described above the drawing is defined as an upper case, and the case described below is defined as a lower case. (A) Opposite ends of the upper case 1 and the lower case 2
The surface has a joining surface 4 which is formed in a plurality of steps and can be closely attached to each other without any gap. (B) The step-like joining surfaces 4 are adhered to each other via an adhesive 5. (C) an end face of the lower case 2 is formed on the end face by <br/> remote wide upper case 1 has a ridge 6 return is located inside the inner surface 1A of the upper case 1. (D) The upper case 1 and the lower case 2 bonded to each other are formed by the return ridge 6 of the lower case 2 and the inner surface 1A of the upper case 1.
A reservoir groove 7 having an adhesive 5 protruding from the joint surface 4 to the inside of the case is formed.

As another means, the upper case 1
The joining surface 4 of the lower case 2 and the lower case 2 may be formed into a curved surface shape that can be in close contact with each other without any gap.

[0009]

FIG. 1 shows a cross section of a battery pack according to a preferred embodiment of the present invention. FIG. 2 shows a main part of FIG. The battery pack shown in FIG. 2 includes a printed circuit board (not shown) and a battery 3.
And the bonding surface 4 of the lower case 2 and the upper case 1 is adhered. The bonding surfaces 4 are in the form of three steps that are in close contact with each other, and are bonded via an adhesive 5. When the joining surface 4 is formed in a three-step shape, two vertical surfaces 4 are formed at the boundary of the horizontal surface 4A.
B is formed, and the bonding area can be increased. Even more advantageously, the vertical surface 4B can be widened irrespective of the thickness of the peripheral wall 8, so that the bonding area of the bonding surface 4 can be widened and firmly bonded.

Further, in the battery pack of the present invention, since the adhesive 5 leaking into the case can be stored in the storage groove 7, a large amount of the adhesive 5 can be applied to the joint surface 4 to securely adhere. In addition, as shown in FIG. 2, in order to store the adhesive 5 protruding from the joint surface 4 without flowing down, the return ridge 6 on the joint surface 4 of the lower case 2 and the inner surface 1A of the upper case 1 form a reservoir groove. 7 are formed. In the case having this structure, when the upper case 1 and the lower case 2 are bonded to each other at the joint surface 4, the adhesive 5 protruding from the joint surface 4 can be stored in the storage groove.

The reservoir groove 7 prevents the adhesive 5 protruding from the joint surface 4 from flowing down and stores the adhesive 5 therein, so that a large amount of the adhesive 5 can be applied to the joint surface 4 to securely adhere. This is because the adhesive that has overflowed from the joint surface 4 does not flow down along the inner surface of the case. The fact that a large amount of the adhesive 5 can be applied to the joint surface 4 spreads the adhesive widely when the case is pressed and bonded. The spreading adhesive spreads to the area where the joining surface was not applied. For this reason, even if the adhesive is not applied to the entire surface of the joining surface, the adhesive can be spread and the entire surface can be firmly adhered. Further, the adhesive 5 accumulated in the groove 7 is effectively used to adhere the upper and lower cases at the boundary between the lower case 2 and the upper case 1.

Further, the step-like joining surface 4 has a feature that it can be positioned vertically and horizontally in FIG. 2 by closely contacting the horizontal surface 4A and the vertical surface 4B. This is because positioning in the vertical direction can be performed on the horizontal surface 4A, and positioning in the horizontal direction can be performed on the vertical surface 4B. The step-like joining surface 4 is the upper case 1
Is pressed in the direction shown by the arrows in FIGS. 1 and 2 so that the vertical surface 4B can be adhered without any gap. The bonding surface 4 that can be positioned up, down, left, and right can press the upper case 1 and the lower case 2 strongly to cure the adhesive 5 in a state where the bonding surface 4 is brought into close contact. Therefore, there is a feature that the bonding surface 4 can be firmly bonded.

On the other hand, the joint surface 4 between the upper case 1 and the lower case 2
Is characterized in that when it is formed into a curved surface shape that can be in close contact with each other without any gap, it can be easily positioned while sliding along the curved surfaces.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. The battery pack shown in FIGS. 1 to 5 includes a box-shaped lower case 2, an upper case 1 adhered to the lower case 2,
It comprises a battery 3 and a printed circuit board 9 which are put in a lower case 2.

The upper case 1 and the lower case 2 are made of plastic such as ABS, nylon, urethane, vinyl chloride, polyethylene and the like. The lower case 2 is formed in a box shape with an open top in which the two batteries 3 and the printed board 9 are put, and has a peripheral wall 8 around the lower case 2. The upper case 1 is an arch-shaped lid and has a peripheral wall 8 around it. By bonding the peripheral walls 8 of the upper case 1 and the lower case 2, the case is sealed as shown in FIG.

The bonding portion of the peripheral wall 8 is shown in FIGS. In the peripheral wall 8 shown in these figures, the joint surface 4 is formed in three steps. The step-like joining surface 4 is shaped so that the horizontal surface 4A and the vertical surface 4B can be in close contact with each other.

The stair-shaped joining surface 4 shown in FIG. 2 includes, in order from the bottom, 1, 2 and 3 levels of horizontal surfaces 4A and these horizontal surfaces 4A.
, And one or two vertical surfaces 4B at the boundary. The first-stage horizontal surface 4A has the lower case 2 side formed wider than the upper case 1. This is because the return ridge 6 is provided on the lower case 2 side. The horizontal surface 4A of the second stage is the lower case 2 and the upper case 1
And have the same width. This is for bringing the vertical surfaces 4B of the first and second stages into close contact. The third level horizontal surface 4A is formed narrower than the upper case 1 by providing an outer groove on the lower case 2 side. This is because the outer groove of the lower case 2 provides the creviced gap 10 outside the case. First and second vertical surfaces 4B
The lower case 2 and the upper case 1 have the same width in order to make the horizontal surface 4A adhere.

In order to make the horizontal plane 4A of the first step of the lower case 2 wider than the upper case 1, the end face of the lower case 2 is formed wider than the upper case 1. That is, the peripheral wall 8 of the lower case 2 is formed thicker than the peripheral wall 8 of the upper case 1. The joining surface 4 of the wide lower case 2 forms a return ridge 6 on the inner edge of the first stage. The return ridge 6 has an upper surface inclined upward and inward toward the inside of the case. The inclined surface of the return ridge 6 forms a reservoir groove 7 with the inner surface 1 </ b> A of the peripheral wall 8 of the upper case 1. The reservoir 7 stores the adhesive 5 extruded from the joint surface 4 and prevents the adhesive 5 from flowing down along the inner surface of the peripheral wall 8. FIG. 2 shows a partial cross-sectional structure of the peripheral wall 8. The joint surface 4 of the lower case 2 and the upper case 1 has the entire circumference shown in FIG.

1 and 2, the battery 3 and the printed circuit board 9 are put in the lower case 2, and the upper case 1 is adhered and sealed as shown in FIGS. Is done. When bonding the case, an adhesive 5 is applied to the joint surface 4 of the upper case 1. Since the joining surface 4 of the upper case 1 faces downward, the lower end of the peripheral wall 8 is brought into contact with the layer containing the adhesive 5 so that the adhesive 5 can be easily applied. However, it goes without saying that if the adhesive 5 is applied to and bonded to the joint surfaces 4 of both the upper case 1 and the lower case 2, the bonding can be performed more reliably. The most suitable adhesive for the plastic of the case is selected as the adhesive 5 for bonding the bonding surface 4. For example, if the case is ABS, toluene can be used for the adhesive.

When the adhesive 5 is applied and the upper case 1 is pressed against the lower case 2, the adhesive 5 spreads uniformly over the entire joint surface 4 and adheres the joint surface 4. Face 4
Extruded from. The adhesive 5 extruded toward the inside of the case is stored in the storage groove 7 formed by the return ridge 6 and does not flow down. The adhesive 5 in the storage groove 7 bonds the return ridge 6 to the inner surface of the peripheral wall 8 of the upper case 1. Therefore, the reservoir 7
Is used not only to prevent the adhesive 5 from flowing down, but also to connect the upper case 1 and the lower case 2. The adhesive 5 extruded to the outside of the case is stored in the outer groove serving as the joint and is prevented from flowing down.

The upper case 1 to which the adhesive 5 has been applied presses the lower case 2 as shown by the arrow in FIG. The upper case 1 and the lower case 2 shown in FIG. 1 and FIG. 2 have a joint surface 4 in a stepped shape that becomes lower toward the inside of the case. The bonding surface 4 having this shape allows the adhesive 5 to flow down into the reservoir 7 inside the case when pressed and bonded.

The printed circuit board 9 built in the case is made of FE
LSIs such as T and one-chip microcomputer are soldered. The battery 3 is a rechargeable secondary battery, for example, a lithium ion battery, a nickel cadmium battery, a nickel hydride battery, or the like.

FIGS. 6 and 7 show another embodiment of the present invention. That is, the joining surface 4 shown in FIGS. 6 and 7 has an elliptical shape. For this reason, there is a feature that the positioning can be easily performed while sliding along the curved surfaces of each other. In this embodiment, the return ridges 6, the reservoirs 7, and the crevices 10 are also formed.

[0024]

The battery pack of the present invention has a feature that an electronic component and a battery are built therein, and the upper case and the lower case can be easily and easily and firmly adhered. Make the joint surface between the upper case and the lower case
This is because the end face is wider than the upper case, and the adhesive groove is provided by the return ridge. The stair-shaped joining surface can not only increase the bonding area but also position the top, bottom, left and right between the horizontal plane and the vertical surface, and can adhere in a state where the entire joining surface is in close contact. In particular, the step-like joining surface has a feature that all vertical surfaces can be brought into close contact with each other in a pressed state by pressing in a direction in which the vertical surfaces are brought into close contact with each other. For this reason, both the vertical surface and the horizontal surface can be adhered in close contact.

Further, in the battery pack of the present invention, since the adhesive leaking from the joint surface is stored in the storage groove, a large amount of adhesive can be applied to bond the upper case and the lower case. For this reason,
The feature is that the portion where the adhesive is not applied can be reduced, and all the joint surfaces can be securely bonded without adhesion unevenness. This is synergistic with the fact that the vertical surface and the horizontal surface can be pressed against each other to be in close contact with each other. Particularly, in the manufacturing process of a mass-produced battery pack, an adhesive can be applied to the joint surface by a simple method, which has a feature that the production efficiency can be increased and the number of defective products can be reduced. Even if there is a part where the adhesive is not applied locally on the joint surface where a large amount of adhesive is applied, when the joint surface is pressed and brought into close contact, the adjacent adhesive moves and the entire surface is uniformly bonded. .

Further, in the battery pack of the present invention, the adhesive leaking from the joint surface is stored in the storage groove and is effectively used for coupling the upper case and the lower case, so that the adhesive leaking from the joint surface flows down. And the upper case and the lower case can be firmly joined together by effectively using all the applied adhesive.

On the other hand, the joint surface 4 between the upper case 1 and the lower case 2
Is characterized in that when it is formed into a curved surface shape that can be in close contact with each other without any gap, it can be easily positioned while sliding along the curved surfaces.

[Brief description of the drawings]

FIG. 1 is a sectional view of a battery pack according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the battery pack shown in FIG. 1;

FIG. 3 is an exploded perspective view of the battery pack shown in FIG. 1;

FIG. 4 is a perspective view showing an assembled state of the battery pack shown in FIG. 1;

FIG. 5 is a perspective view of the battery pack shown in FIG. 1;

FIG. 6 is a sectional view of a battery pack according to another embodiment of the present invention.

FIG. 7 is an enlarged sectional view of a main part of the battery pack shown in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Upper case 1A Inner surface 2 Lower case 3 Battery 4 Joining surface 4A Horizontal surface 4B
Vertical surface 5 Adhesive 6 Return ridge 7 Reservoir 8 Peripheral wall 9 Printed circuit board 10

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 2/10 B65D 6/32

Claims (2)

(57) [Claims] 1. An upper case 1 and a lower case 2 which are separately formed are connected to each other, and a battery 3 and an electronic component are built therein, and all of the following configurations are provided. Battery pack. (A) Opposite ends of the upper case 1 and the lower case 2
The surface has a joining surface 4 which is formed in a plurality of steps and can be closely attached to each other without any gap. (B) The step-like joining surfaces 4 are adhered to each other via an adhesive 5. (C) an end face of the lower case 2 is formed on the end face by <br/> remote wide upper case 1 has a ridge 6 return is located inside the inner surface 1A of the upper case 1. (D) The upper case 1 and the lower case 2 bonded to each other are formed by the return ridge 6 of the lower case 2 and the inner surface 1A of the upper case 1.
And a reservoir groove 7 having an adhesive 5 protruding from the joint surface 4 to the inside of the case. 2. An upper case 1 and a lower case 2 which are separately formed are connected to each other to incorporate a battery 3 and an electronic component therein, and have all of the following configurations. Battery pack. (A) Opposite ends of the upper case 1 and the lower case 2
Surface was formed into a curved surface which can contact without gaps each other against
It has a mating surface 4 . (B) The curved joint surfaces 4 are bonded to each other via an adhesive 5. (C) an end face of the lower case 2 is formed on the end face by <br/> remote wide upper case 1 has a ridge 6 return is located inside the inner surface 1A of the upper case 1. (D) The upper case 1 and the lower case 2 bonded to each other are formed by the return ridge 6 of the lower case 2 and the inner surface 1A of the upper case 1.
And a reservoir groove 7 having an adhesive 5 protruding from the joint surface 4 to the inside of the case.