JP2005190852A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of preventing a molten resin when two case halves are joined by welding from flowing out to the inside or the outside of the case.
On the end surface 15 of the side plate 16 formed on the outer periphery of the upper case half body 1, suitable length welding ribs 11 having notches 12, 12... Are provided in the length direction of the side plate 16. There is a circumference. The end face 22 of the side plate 23 formed on the outer periphery of the lower case half 2 faces the notch 12 and is parallel to the length direction of the welding rib 11, and the regulating rib 21 is formed on the inner surface of the side plate 23. Are formed along. The height H2 from the end surface 22 of the regulating rib 21 is lower than the height H1 from the end surface 15 of the welding rib 11, and the length L2 of the regulating rib 21 is larger than the length L1 of the notch 12, and the regulating rib 21 Opposite end portions 25, 25 at the ends in the length direction.
[Selection] Figure 2

Description

  The present invention relates to a battery pack that is made of synthetic resin and has a battery built in by joining end faces of side plates formed on the outer periphery of two case halves by welding.

  A battery pack incorporating a plurality of batteries, a wiring circuit, and the like is used as a driving power source for small electronic devices or portable devices. The casing of the battery pack is made of synthetic resin and is composed of two case halves. In the battery pack, the concave portion of one case half is disposed upward, the battery is disposed in the concave portion, the concave portion of the other case half is disposed downward, and the battery is stored in the upper and lower cases. The end surfaces of the side plates formed on the outer periphery of the half body are welded and joined together by ultrasonic welding.

  2. Description of the Related Art In recent years, as devices become lighter, thinner, and smaller, battery packs built into the devices are also desired to be reduced in size and weight. As a result, not only miniaturization of the battery and the wiring circuit, but also the battery pack housing is required to be light and thin.

  The case half is made lighter by reducing the thickness of the case half, but when the case half is set thin, the strength when the case half is joined and integrated is increased. It is necessary to ensure sufficient and to maintain the accuracy of the joining position.

For this reason, the end surface of the side plate formed on the outer periphery of the rectangular upper case half body is welded to the end surface of the side plate formed on the outer periphery of the rectangular lower case half body, and includes a plurality of notches. A plurality of plate-shaped welding ribs are provided around the end surface of the side plate of the lower case half so as to be shorter than the length of the notch and regulate the separation from the end surface during welding of the welding ribs. A plate-shaped regulating rib is formed opposite to the notch, and the height from the end surface of the regulating rib is made higher than the height from the end surface of the welding rib, so that vibration generated during ultrasonic welding is generated. Due to the positional displacement between the end face of the side plate of the upper case half and the end face of the side plate of the lower case half due to the influence, the welding ribs provided around the end face of the side plate of the upper case half become the side plate of the lower case half Slips off the end face of the case and slides inside the lower case half Have been proposed to prevent the (see Patent Document 1).
JP 2002-245993 A

  However, in the battery pack of Patent Document 1, since the height from the end face of the regulating rib is higher than the height from the end face of the welding rib, the welding rib moves to the regulating rib side due to vibration during ultrasonic welding. Then, there is a possibility that the inner side surface of the upper case half around which the welding rib is provided and the side surface of the regulating rib are in contact with each other, and heat generation immediately after the ultrasonic welding is started causes the inner side of the upper case half. In some cases, the side surface and the side surface of the regulation rib melt. For this reason, when molten resin flows and welds inside the case, it may interfere with built-in components such as a battery or a wiring circuit, resulting in poor appearance such as deformation of the side plate of the case. In addition, since the gap between the inside of the case and the battery is small, the molten resin that has flowed inside the case may flow out of the case due to pressure from the built-in parts and be welded, which may cause poor appearance. .

  The present invention has been made in view of such circumstances, and the height from the end face of the welding rib is smaller than the height from the end face of the welding rib having a plurality of notches, and the restriction rib is provided. Is longer than the length of the cut-out portion, and both ends of the regulating rib are provided with opposing portions facing the welding rib, so that one case half in which the welding rib is circumferentially provided at the time of welding is provided. It is possible to reduce the cause of defects caused by the molten resin by preventing the inner side surface of the metal plate and the side surface of the regulating rib from contacting and melting, and the welding rib is caused to vibrate by vibration during welding. It is an object of the present invention to provide a battery pack that can be prevented from slipping off from the end face of the other case half formed with the inside of the other case half.

  Another object of the present invention is to reduce the height from the end face of the regulation rib to 80% or less of the height from the end face of the weld rib, thereby making the case half in which the weld rib is provided circumferentially at the time of welding. An object of the present invention is to provide a battery pack capable of preventing the inner side surface of the body and the side surface of the regulating rib from contacting and melting.

  Another object of the present invention is that the length of the opposing portion of the regulating rib is 150% or more and 500% or less of the height of the welding rib, so that the welding rib is caused by vibration during welding, While preventing sliding down to the inside of the other case half, reducing the possibility that the inner side surface of the case half around which the welding rib is provided at the time of welding and the side surface of the regulating rib are in contact with each other and melted, An object of the present invention is to provide a battery pack capable of preventing molten resin at the time of welding from flowing out of the case outside or inside.

  Another object of the present invention is that the length of the facing portion of the regulation rib is 200% or more and 400% or less of the height of the welding rib, so that the welding rib is caused by vibration during welding, While preventing the inside of the other half of the case from slipping down, the area of contact between the inner side surface of the case half around which the welding rib is provided and the side surface of the regulating rib during melting is further reduced. It is an object of the present invention to provide a battery pack that can further reduce the possibility of occurrence and reliably prevent the molten resin at the time of welding from flowing out to the outside or inside of the case.

  A battery pack according to a first aspect of the present invention includes a case configured by welding two case halves having side plates formed on the outer periphery thereof, and a battery stored in the case, and the side plate of one case half The end face of the other case half is welded to the other case half and is provided with a plurality of cutout ribs. The end face of the side plate of the other case half is connected to the end face of the weld rib from the end face. In the battery pack in which a plurality of regulating ribs that regulate detachment in welding are formed facing the notch, the height from the end surface of the regulating rib is lower than the height from the end surface of the welding rib, The length of the regulation rib is longer than the length of the notch, and both end portions of the regulation rib each have a facing portion that faces the welding rib.

  The battery pack according to a second aspect of the present invention is characterized in that a height from the end face of the regulation rib is 80% or less of a height from the end face of the welding rib.

  The battery pack according to a third aspect of the invention is characterized in that the length of the regulating rib of the facing portion is 150% or more and 500% or less of the height from the end face of the welding rib.

  The battery pack according to a fourth aspect of the invention is characterized in that the length of the regulating rib of the facing portion is 200% or more and 400% or less of the height from the end face of the welding rib.

  In the first invention, the other case half is disposed with the end face on which the regulation rib is formed facing upward, and a built-in component such as a battery or a wiring circuit is accommodated in the case half, The one case half is disposed so that the end surface on which the welding rib is formed faces downward, and the welding rib contacts the end surface of the other case half, and the ultrasonic welding jig is placed on the one case. Abut on the upper half. At the time of welding, welding is performed by applying a high frequency to melt the welding rib and the end face by frictional heat between the welding rib and the end face of the other case half. From the height from the end surface of the welding rib provided around one case half disposed on the upper side during welding, from the end surface of the regulation rib formed on the other case half disposed below during welding. Therefore, even if the position of the welding rib is shifted inwardly of the end surface of the other case half due to vibration after the start of welding, one case half in which the welding rib is provided circumferentially is provided. There is no possibility of contact between the inner side surface and the side surface of the regulating rib. For this reason, due to the heat generated at the start of welding, the inner side surface of the one case half and the side surface of the regulating rib are melted, and the molten resin is mixed into the built-in parts inside the case and flows out to the outside of the case. Can be prevented. Further, the length of the regulation rib is longer than the length of the notch, and by providing opposing portions facing the welding rib at both ends of the regulation rib, the welding rib is caused by vibration during welding. Even when the position is displaced inwardly of the end surface of the other case half, the opposing portions of both ends of the restriction rib restrict the detachment of the welding rib from the end surface, and the welding rib is in the other side. Can be prevented from falling inside the case half.

  In the second invention, the height from the end face of the restriction rib is set to 80% or less of the height from the end face of the weld rib, so that the weld rib at the start of welding is surrounded. It can prevent reliably that the inner surface of one case half provided and the side surface of a control rib contact. That is, since the restriction rib is formed, the welding surface of the welding rib is displaced inwardly of the end surface of the other case half due to vibration at the start of welding and falls to the inside of the case half. It is possible to prevent welding in a state of being damaged. On the other hand, when the height of the regulating rib exceeds 80% of the height of the welding rib, the welding rib and the end face of the other case half are melted due to heat generation after the welding starts. In the process, there is a possibility that the inner side surface of the case half around which the welding rib is provided and the side surface of the regulating rib come into contact with each other and weld.

  In the third invention, the length of the facing portion of the regulating rib is set to 150% or more and 500% or less of the height of the welding rib, so that vibration of the welding rib is caused by vibration after starting welding. It is possible to prevent the welding surface from being displaced in the inner side direction of the end surface of the other case half and falling to the inside of the case half and to prevent the welding due to the heat generated after the welding starts. It is possible to reduce the possibility that the inner side surface of the case half provided with the ribs and the side surface of the regulating rib come into contact with each other and weld. That is, when the length of the facing portion is less than 150% of the height of the welding rib, the welding rib is detached from the end of the regulating rib in the process of welding after the start of welding. There is a possibility of welding while falling inside the case half. On the other hand, when the length of the facing portion exceeds 500% of the height of the welding rib, since the area of the facing portion of the regulating rib is large, the side surface of the welding rib in the process of welding progressing at the start of welding. And the side surface of the regulating rib may come into contact and weld.

  In 4th invention, the length of the said opposing part of the said regulation rib shall be 200% or more and 400% or less of the height of the said welding rib, By the vibration after a welding start, the said welding rib's It is possible to prevent the welding surface from being displaced in the inner side direction of the end surface of the other case and falling to the inside of the case half body, and to prevent the welding rib from being generated by heat generation after the welding starts. The possibility that the inner side surface of the circumferential case half and the side surface of the regulating rib come into contact with each other to be welded can be reduced. That is, by setting the lower limit value of the length of the facing portion to 150% to 200% of the height of the welding rib, the welding rib is detached from the end portion of the regulating rib in the process of welding progress after the welding starts. Thus, it is possible to reduce the possibility of being welded in the state of falling inside the other case half. On the other hand, by setting the upper limit value of the length of the facing portion to 500% to 400% of the height of the welding rib, the area of the facing portion of the regulating rib can be further reduced, and welding is started at the start of welding. In the process of proceeding, the possibility that the side surface of the welding rib and the side surface of the regulating rib come into contact with each other and weld can be reduced.

  In the present invention, the height from the end face of the restriction rib is lower than the height from the end face of the welding rib, and the length of the restriction rib formed to face the notch is the cut edge. Longer than the length of the notch, and by providing opposing portions facing the welding ribs at both ends of the regulating rib, the welding ribs are prevented from sliding down inside the case half due to vibration at the start of welding. In addition, it is possible to prevent the side surface of the regulating rib from coming into contact with the inner side surface of the case half around which the welding rib is provided after the start of welding, and the molten resin at the time of welding flows out to the outside or inside of the case Can be prevented, and the cause of failure due to the molten resin can be removed.

  Moreover, in this invention, it can prevent reliably that the inner side surface of the case half body in which the said welding rib was provided in the circumference | surroundings at the time of a welding start, and the side surface of a control rib contact.

  Further, in the present invention, it is possible to prevent the welding rib from sliding down to the inside of the case after the start of welding, and to prevent the molten resin in the welding process from flowing out to the outside or inside of the case. it can.

  Further, in the present invention, it is possible to reliably prevent the welding rib from slipping down to the inside of the case after the start of welding, and to prevent molten resin in the welding process from flowing out to the outside or inside of the case. be able to.

  FIG. 1 is an exploded perspective view showing the structure of the battery pack before welding. In the figure, reference numerals 1 and 2 respectively denote an upper case half and a lower case half made of a thermoplastic synthetic resin, which are joined by welding to form a case body. In the upper case half 1 and the lower case half 2, side plates 16 and 23 are provided around the substantially rectangular flat plates 17 and 26, respectively.

  When welding, the lower case half 2 is disposed with the side plate 23 of the lower case half 2 facing upward, and the recess surrounded by the side plate 23 of the lower case half 2 is for taking out electric power. The positive and negative electrode plates 4, 4 constitute a circuit that prevents overcharge and overdischarge, and the protective circuit board 5 that is connected to the positive and negative electrode plates 4, 4, and the insulation that insulates the electrode plate 4 from the battery 3 casing. After housing the battery 3 to which the protective element 7 that protects the battery 3 in the event of an abnormality such as the plate 6 and a short circuit is housed, the side plate 16 of the upper case half 1 is on the lower side, and the side plate of the lower case half 2 23 and the side plate 16 of the upper case half 1 are brought into contact with each other, an ultrasonic welding jig is brought into contact with the upper side of the upper case half 1 to perform ultrasonic welding, and the upper case half 1 and the lower case half are brought together. 2 are welded and integrated.

  FIG. 2 is a perspective view showing a joint portion between the upper case half 1 and the lower case half 2 before welding. FIG. 3 is an enlarged view showing a joined portion of the upper case half 1 and the lower case half 2 before welding as seen from the inside of the case. The outer periphery of the side plate 16 of the upper case half 1 is provided with a fitting portion 17 having an L-shaped cross section in the thickness direction and is provided on the outer surface of the side plate 23 of the lower case half 2. It is fitted to the flange 24. Thereby, the side plate 16 of the upper case half 1 is prevented from being detached outside the side plate 23 of the lower case 2 during welding, and the side plate 16 and the side plate 23 are aligned.

  On the end face 15 of the side plate 16, welding ribs 11, 11,... Having appropriate lengths having notches 12, 12,. The thickness of the welding rib 11 is tapered from the side plate 16 side toward the welding surface of the welding rib 11, and the thickness dimension is made smaller on the welding surface of the welding rib 11.

  On the end surface 22 of the side plate 23, a regulating rib 21 is formed along the inner surface of the side plate 23 so as to face the notch 12 and parallel to the length direction of the welding rib 11. At the time of welding, the welding surface of the welding rib 11 is brought into contact with the end surface 22.

  The height H2 from the end surface 22 of the regulating rib 21 is a dimension that is 80% or less of the height H1 from the end surface 15 of the welding rib 11, and the length L2 of the regulating rib 21 is the length L1 of the notch portion 12. Each of the end portions of the regulating rib 21 in the length direction includes opposed portions 25 and 25 facing the welding rib 11, and the length D of the facing portions 25 and 25 is 150 which is the height H1 of the welding rib 11. % Or more and 500% or less.

  For example, the length of the welding rib 11 can be 4 mm, the length L1 of the notch 12 can be 4 mm, and the height H1 of the welding rib 11 can be 0.35 mm. In this case, the length of the facing portion 25 of the regulating rib 21 is a dimension of 0.525 mm or more and 1.75 mm or less.

  More preferably, the length D of the facing portions 25 and 25 of the regulating rib 21 is a dimension that is 200% or more and 400% or less of the height H1 of the welding rib 11. In this case, the length of the facing portion 25 of the regulating rib 21 is a dimension of 0.7 mm or more and 1.4 mm or less. More preferably, the length of the facing portion 25 of the regulating rib 21 is 1.0 mm. Thereby, the possibility of the fusion of the welding rib 11 and the regulating rib 21 can be reduced by making the area of the facing portion 25 smaller.

  Next, the operation at the time of ultrasonic welding will be described. FIG. 4 is a perspective view showing a joint portion after the upper case half 1 and the lower case half 2 are welded. The battery 3 with the circuit components attached is disposed in a recess surrounded by the side plate 23 of the lower case half 2, and the welding rib 11 of the upper case half 1 is brought into contact with the end surface 22 of the lower case half 2. Deploy.

  When an ultrasonic welding jig is placed at a predetermined position in contact with the upper side of the upper case half 1 and a required high frequency is applied, vibration is applied to the upper case half 1 and the welding rib 11 and the lower side The end surface 22 of the case half 2 is heated to a high temperature by frictional heat due to vibration, and the welding rib 11 and the end surface 22 of the lower case half 2 are melted. When the application of the high frequency is finished, the temperature of the melted portion gradually decreases, the amount of the molten resin decreases, and the end surface 15 of the upper case half 1 and the end surface 22 of the lower case half 2 are welded. Integrated.

  During the welding process, the welding rib 11, the side plate 13 in the vicinity of the welding rib 11, the end surface 22, the regulating rib 21, and the like are heated by the frictional heat. However, since the height from the end surface 22 of the regulating rib 21 is lower than the height from the end surface 15 of the welding rib 11 in the state heated to the highest temperature at the start of welding, the inner surface of the side plate 13 and the regulating rib 21 The inner side surface of the side plate 13 and the outer side surface of the regulating rib 21 are melted without contact with the outer side surface, and the melted resin flows into the upper and lower case halves 1 and 2, and the battery 3 and the like. In addition, since the gap between the battery 3 and the upper and lower case halves 1 and 2 is small, the molten resin flowing into the gap between the battery 3 flows out of the gap. , Can be prevented from flowing out of the upper and lower case halves 1 and 2.

  Further, when the application of the high frequency is finished, the frictional heat gradually decreases and the amount of resin to be melted also decreases. Therefore, it is preferable that the height of the regulating rib 21 is small. Similarly, the smaller the area of the opposing portions 25, 25 of the end portions of the regulating rib 21, the possibility of melting the welding rib 11 and the regulating rib 21 can be reduced, and unnecessary molten resin can flow out. It becomes possible to suppress.

  Although the thickness of the welding rib 11 was formed in the taper shape, it is not restricted to this shape. For example, any shape is possible as long as the welding strength can be ensured, such as a triangular shape or a rectangular shape.

  The height of the welding rib 11 is not limited to 0.35 mm, and can be formed to an appropriate dimension according to the size of 0.4 mm and the upper and lower case halves 1 and 2. Further, the length of the welding rib 11 is not limited to 4 mm, and can be formed to an appropriate dimension of 5 mm and 6 mm.

  The longitudinal cross-sectional shape of the regulating rib 21 in the length direction is not limited to a quadrangular shape, and may be a triangular shape or a semicircular arc shape.

It is a disassembled perspective view which shows the structure of the battery pack before welding. It is a perspective view which shows the junction part before welding of an upper case half body and a lower case half body. It is an enlarged view which shows the junction part before welding seen from the case inner side of the upper case half and the lower case half. It is a perspective view which shows the junction part after welding of an upper case half body and a lower case half body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper case half body 2 Lower case half body 3 Battery 11 Welding rib 12 Notch part 13 Side plate 15 End surface 16 Side plate 21 Restriction rib 22 End surface 23 Side plate 25 Opposite part

Claims (4)

A case formed by welding two case halves each having a side plate formed on the outer periphery thereof by welding, and a battery housed in the case; A plurality of notches that are welded to the body and provided with a plurality of notches, and that are provided on the end face of the side plate of the other case half to restrict detachment of the weld rib from the end face. In the battery pack in which the rib is formed to face the notch,
The height from the end face of the restriction rib is lower than the height from the end face of the welding rib, the length of the restriction rib is longer than the length of the notch, and both end portions of the restriction rib are welded. A battery pack comprising a facing portion facing the rib.   2. The battery pack according to claim 1, wherein a height from an end surface of the restriction rib is 80% or less of a height from an end surface of the welding rib.   3. The battery pack according to claim 1, wherein a length of the regulation rib of the facing portion is 150% or more and 500% or less of a height from an end surface of the welding rib.   4. The battery pack according to claim 1, wherein a length of the regulation rib of the facing portion is 200% or more and 400% or less of a height from an end surface of the welding rib.

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