JP2010092728A - Fuse unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuse unit minimized in dispersion of a fusing site and stabilizing meltdown characteristics. <P>SOLUTION: The fuse unit includes: a resin body mounted on an upper surface of a battery; a fuse housing space 11 formed on the resin body and having a bottom surface 53 parallel to the upper surface of the battery; a bus bar 13 disposed in the fuse housing space 11 and having a fusible part 15 at the center; an inclination part 55 formed at a site including the fusible part 15 of the bus bar 13 and gradually raised up from the bottom surface 53; a caulking holding part 57 formed on a bus bar 13b continued to an upper portion of the inclination part 55; and a low-melting point metal 61 having a base end portion 61a held by the caulking holding part 57 and a tip portion 61b disposed above the inclination part 55. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuse unit in which a low melting point metal is held in the vicinity of a fusible portion.

  A fuse is known in which a low melting point metal (tin, lead, etc.) is held near the fusible part formed in the fuse element, and the fusing characteristics are improved by forming an alloy by diffusion of the low melting point metal. (For example, see Patent Documents 1 and 2). A conventional fuse similar to these publications is shown in FIG. The fuse 501 shown here is housed in a fuse housing space 505 formed in an insulating resin body 503, and has strip-shaped bus bars 507 and 507 formed at both ends, and substantially the center of the bus bars 507 and 507. A fuse element 511 having a structure in which a narrow soluble portion 509 formed in the portion is integrally formed by press molding of a metal plate is provided.

  A chip-like low melting point metal 513 having a melting point lower than that of the fusible part 509 is fastened to one bus bar 507 near the fusible part 509 by a pair of caulking pieces 515. The caulking piece 515 is formed by extending the bus bar 507 in the width direction, and is bent and caulked so as to wrap the low melting point metal 513, thereby fixing the low melting point metal 513 by pressure bonding. The low melting point metal 513 may be further welded in addition to crimping and fixing by caulking.

  In the fuse 501 configured as described above, when a voltage is applied between the bus bars 507 and 507 and an overcurrent flows through the fuse element 511, the low melting point metal 513 diffuses into the fuse element 511 and the alloy layer becomes soluble. It forms on the part 509 side (namely, it welds). At that time, since the specific resistance of the alloy layer is higher than that of the low melting point metal 513 and the fuse element 511, Joule heat is generated in the alloy layer, and the fusible portion 509 of the fuse element 511 is melted by the Joule heat.

Japanese Utility Model Publication No. 3-13960 Japanese Patent Laid-Open No. 7-14494

However, the surface of the alloy layer formed by the low melting point metal 513 and the fuse element 511 becomes apparent in one direction according to the fuse installation direction because the diffusion of the metal proceeds in the direction of gravity. For this reason, if there is poor welding due to overmelting or insufficient melting of the low melting point metal due to variations in the fuse manufacturing equipment and the actual vehicle mounting environment, the low melting point metal is sufficient in the welding range A (see FIGS. 7 and 8). In some cases, welding did not occur. As a result, there has been a problem that the fusing part, the fusing characteristics of the fuse vary, or the fusing occurs.
The present invention has been made in view of the above situation, and an object of the present invention is to provide a fuse unit that can reduce the variation in fusing part and stabilize fusing characteristics.

The above object of the present invention is achieved by the following configuration.
(1) a resin body attached to the upper surface of the battery;
A fuse housing space formed in the resin body and having a bottom surface parallel to the top surface;
A bus bar disposed in the fuse housing space and having a fusible portion at the center;
An inclined portion that is formed at a portion including the soluble portion of the bus bar and gradually floats from the bottom surface;
A caulking holding portion formed on a bus bar connected to an upper portion of the inclined portion;
A low melting point metal in which a base end portion is held by the caulking holding portion and a distal end portion is disposed above the inclined portion;
A fuse unit comprising:

  According to this fuse unit, when the low melting point metal is melted, the molten low melting point metal flows along the inclined portion by gravity to the fusible portion (melting portion), and the welding to the target location is promoted. Thereby, the low melting point metal melted in the soluble portion of the bus bar having a high resistance value flows and welds reliably, and no defect due to insufficient welding occurs.

(2) The fuse unit of (1),
A fuse unit, wherein a crank-shaped portion is formed at a portion of a bus bar parallel to the upper surface.

  According to this fuse unit, an inclined portion and a crank-shaped portion are formed on the bus bar, and the bus bar has a bent portion on both a surface parallel to the battery upper surface and a surface perpendicular to the battery upper surface. The bent portion arranged in the plane can be deformed by a stress from an arbitrary direction (up / down / left / right front / rear direction). Thereby, the stress concentration to the soluble part due to the shrinkage at the time of molding the bus bar or the actual vehicle vibration is alleviated.

(3) The fuse unit of (1) or (2),
The inclined portion is formed on one oblique side portion of the bus bar that is bent in a heft shape,
The fuse unit, wherein the caulking holding portion is formed on the other oblique side portion of the bus bar.

  According to this fuse unit, the inclined portion is formed in the bus bar by a simple bending process, and the caulking holding portion is provided on the top portion thereof, so that the low melting point metal is easily arranged above the inclined portion with a simple structure. It becomes possible.

(4) The fuse unit of (1) or (2),
The inclined portion is formed on the hypotenuse of the bus bar bent into a trapezoidal convex shape,
The fuse unit, wherein the caulking holding portion is formed on an upper side portion of the bus bar.

  According to this fuse unit, the bus bar continuing to the upper part of the inclined portion becomes the upper side parallel to the upper surface of the battery, and the caulking holding part is provided on the upper side, so that the molten low melting point metal and the soluble part It does not flow out to the inclined surface on the opposite side (for example, when it is formed in a letter shape), and the molten low melting point metal is welded to the soluble part without waste.

(5) The fuse unit of (1) to (4),
The fuse element consists of a pair of plates that bend through a hinge,
The bus bar is formed on one plate portion and the resin body is provided,
The other plate body is provided with the other resin body separate from the resin body,
The fuse unit, wherein the one resin body and the other resin body are locked in a state of being bent with the hinge as a boundary.

  According to this fuse unit, a pair of resin bodies are bent via a hinge, one resin body is parallel to the battery upper surface, the other resin body is disposed parallel to the battery vertical surface, and the fuse housing space is horizontally disposed. The amount of protrusion in the horizontal direction is shortened, and the space in the engine room can be saved. In addition, each resin body can be integrally molded (insert molding, etc.) on the fuse element expanded in a plane, and the molding die can be simplified and the cost can be reduced compared to molding the resin body on the bent fuse element. .

  According to the fuse unit of the present invention, the inclined portion is formed in the portion including the fusible portion of the bus bar, the caulking holding portion is provided in the bus bar connected to the upper portion of the inclined portion, and the tip portion is above the inclined portion. Since the low melting point metal is held in the caulking holding part, the molten low melting point metal flows along the inclined part to the soluble part, thereby eliminating the variation in the fusing part and stabilizing the fusing characteristics. it can.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of a fuse unit according to the invention will be described with reference to the drawings.
FIG. 1 is an enlarged perspective view of a main part of a fuse unit according to the present invention, FIG. 2 is a perspective view of a fuse element provided in the fuse unit, and FIG. 3 is an external perspective view of the fuse unit according to the present invention.
A fusible portion 15 is formed in the bus bar 13 disposed in the fuse accommodating space 11. The bus bar 13 is formed in the fuse element 17 shown in FIG. The fuse element 17 is formed by stamping from a single conductive metal plate, and integrally includes a flexible hinge 19 at an intermediate portion thereof. The hinge 19 can be bent in the thickness direction.

  The fuse element 17 is shown in FIG. 3, which is an insulating synthetic resin material on the front and back of the one plate portion 21 and the other plate portion 23 with the hinge 19 as a boundary in a state where the fuse element 17 is not shown, but is extended in a flat plate shape. The resin bodies 25 and 27 are integrally molded (for example, insert molding). The hinge 19 of the fuse element 17 is not covered with the resin bodies 25 and 27 and is exposed by being disposed in a portion of the resin molding die (not shown) where the resin material is not injected. That is, the resin bodies 25 and 27 are formed by dividing the hinge 19 into two parts.

  A plurality (two in the illustrated example) of bus bars 13 are formed on one plate portion 21 of the fuse element 17. A plurality (three) of tab terminals 29 are formed in parallel at the end of the other plate portion 23. As shown in FIG. 2, the fuse element 17 can be bent by rotating the other plate portion 23 downward through the hinge 19. One plate portion 21 is provided with a terminal insertion bolt insertion hole 31. A convex plate portion 33 is formed at the end of one plate portion 21, and a bolt insertion hole 35 for battery connection is formed in the convex plate portion 33.

  The resin body 27 is integrally formed with a connector housing portion 37 that accommodates each tab terminal 29 in a state where the fuse element 17 is insert-molded. The tab terminal 29 is disposed so as to protrude into the connector fitting chamber of the connector housing portion 37. The resin body 25 is formed with the plural (two) fuse accommodating spaces 11. Each fuse accommodating space 11 is covered on the upper and lower sides with a cover having a transparent window (not shown), and is attached to the resin body 25 by a locking means. A plurality of radiating fins 39 and 41 are integrally provided on the resin bodies 25 and 27 covering the one plate portion 21 and the other plate portion 23. In FIG. 3, reference numeral 43 denotes a stud bolt whose head is fixed simultaneously at the time of insert molding and constitutes a terminal connecting portion with the exposed surface 45.

The resin bodies 25 and 27 are provided with a locking means (not shown) that locks the resin bodies 25 and 27 so as to face each other while being bent at 90 degrees via the hinge 19. Therefore, one resin body 25 and the other resin body 27 are locked in a state of being bent with the hinge 19 as a boundary.
The fuse element 17 and the resin bodies 25 and 27 constitute a fuse unit 51. In the fuse unit 51, the pair of resin bodies 25 and 27 are bent via the hinge 19, so that one resin body 25 is parallel to the battery upper surface (not shown) and the other resin body 27 is parallel to the battery vertical surface. Placed in.

  As a result, the fuse unit 51 can easily arrange the fuse housing space 11 in the horizontal direction, and the amount of protrusion in the horizontal direction (in the direction of arrow a in FIG. 3) is shortened, thereby enabling space saving in the engine room. In addition, the resin bodies 25 and 27 can be integrally formed on the fuse element 17 that is flatly developed, and the molding die can be simplified and the cost can be reduced as compared with the case where the resin bodies 25 and 27 are formed on the bent fuse element 17. It is possible.

  In the fuse housing space 11 of the resin body 25 attached to the battery upper surface, the bottom surface 53 is arranged in parallel with the battery upper surface. The bus bar 13 disposed in the fuse accommodating space 11 has a fusible portion 15 at the center. Here, an inclined portion 55 that gradually rises from the bottom surface 53 is formed at a portion including the soluble portion 15 of the bus bar 13. That is, the inclined portion 55 is inclined with respect to the bottom surface 53 at an inclination angle of α. The lower end portion of the inclined portion 55 is connected to the bus bar 13 a parallel to the bottom surface 53. The bus bar 13 a connected to the lower end of the inclined portion 55 may be inclined in the direction opposite to the inclined portion 55 with respect to the bottom surface 53.

FIG. 4 is a side view of an inclined portion formed on the bus bar, and FIG.
A caulking holding portion 57 is formed on the bus bar 13 b connected to the upper portion of the inclined portion 55. The caulking holding part 57 has a pair of caulking pieces 59. The caulking pieces 59 are erected from the outer edge of the bus bar 13b. The crimping piece 59 is bent so as to be pressed against the base end portion 61a of the low melting point metal 61 on the bus bar 13b, and the low melting point metal 61 is sandwiched and fixed between the bus bar 13b.

  The low melting point metal 61 is made of a metal such as tin (Sn) or a tin alloy having a lower melting point than copper (Cu) which is a base material constituting the bus bar 13 or the soluble portion 15 described above. The low melting point metal 61 is disposed on the bus bar 13b and crimped by the crimping piece 59, and then exposed to the melting point temperature of the low melting point metal 61 for a short time, and is fused to the surface of the bus bar 13b.

  The low melting point metal 61 has a base end portion 61 a held by the caulking holding portion 57 and a tip end portion 61 b disposed above the inclined portion 55. That is, the low melting point metal 61 jumps out on the slope so that it easily flows into the welding range. When the low melting point metal 61 is melted, it flows along the inclined surface of the inclined portion 55 to the welding range B-A (fuse blown portion) shown in FIG. 4 as shown in FIG. As a result, fluidity due to gravity is promoted, and the low melting point metal 61 always flows to the B dimension.

  In the fuse element 17, when an overcurrent flows through the fusible portion 15, the current density increases particularly in the portion where the narrow portion (heating easy portion) 13 c is formed, and more Joule heat generation than the bus bars 13 a and 13 b. And the soluble part 15 is easily blown out. Further, when the low melting point metal 61 flows above the easy heat generating portion 13c, the low melting point metal (Sn) 61 diffuses into the copper (Cu) of the easy heat generating portion 13c, and the copper (Cu) The melting point decreases. Therefore, when the overcurrent flows, the easy-to-heat generation portion 13c of the bus bar 13 can be blown out quickly.

  In the present embodiment, the inclined portion 55 including the fusible portion 15 is formed on one oblique side portion of the bus bar 13 that is bent in a U-shape. The caulking holding portion 57 is formed on the other oblique side portion of the bus bar 13 (that is, the bus bar 13b). Accordingly, the inclined portion 55 is formed on the bus bar 13 by a simple bending process, and the low melting point metal 61 can be disposed above the inclined portion 55 with a simple structure by providing the crimp holding portion 57 on the top portion. It becomes.

FIG. 6 is a side view of a modified example of the inclined portion.
In addition, you may form the inclination part 55 in the oblique side part 13d of the bus-bar 13 bent by trapezoid convex shape, as shown in FIG. In this case, the caulking holding portion 57 can be formed on the upper side portion 13e of the bus bar 13 bent into a trapezoidal convex shape. The bus bar 13 continuing to the upper part of the oblique side portion 13d becomes the upper side portion 13e parallel to the upper surface of the battery, and the crimping holding portion 57 is provided on the upper side portion 13e, so that the molten low melting point metal 61 and the soluble portion 15 It does not flow out to the opposite inclined surface (for example, bus bar 13b), and the molten low melting point metal 61 is welded to the soluble portion 15 without waste.

  Further, the fuse element 17 has a portion of the bus bar 13 parallel to the upper surface (bottom surface 53) (in this embodiment, a portion connected to the opposite side of the caulking holding portion 57 with the bus bar 13b interposed therebetween) shown in FIG. 65 is formed. The crank-shaped portion 65 includes a short plate portion 65a parallel to the extending direction of the resin body 25 from the battery (a direction in FIG. 3), a long plate portion 65b, a short plate portion 65c, It consists of a reversing part 65d.

  In the fuse element 17, an inclined portion 55 and a crank-shaped portion 65 are formed in the bus bar 13, and the bus bar 13 is bent (for example, a long plate portion 65b and a short plate) on both the surface parallel to the battery upper surface and the surface perpendicular to the battery upper surface. The plate portion 65c, the reversing portion 65d, the inclined portion 55, and the bus bar 13b) are provided, and the bent portions arranged in these two orthogonal planes can be deformed by a stress from an arbitrary direction (up / down / left / right / front / rear direction). . Thereby, the stress concentration to the soluble part 15 by shrinkage | contraction at the time of bus bar shaping | molding or a real vehicle vibration is eased.

  In the fuse unit 51 having the above configuration, when the low melting point metal 61 is melted, the melted low melting point metal 61 flows by gravity through the inclined portion 55 to the fusible portion (melting portion) 15, and is a welding range B that is a target location. -A (fuse fusing part) welding is promoted. As a result, the molten low melting point metal 61 is surely welded to the soluble portion 15 (especially the easy heat generating portion 13c) having a high resistance value of the bus bar 13, and defects due to insufficient welding are reduced.

Therefore, according to the fuse unit 51, the inclined portion 55 is formed in the portion including the fusible portion 15 of the bus bar 13, and the caulking holding portion 57 is provided on the bus bar 13b connected to the upper portion of the inclined portion 55. Since 61b has held the low melting point metal 61 located above the inclined portion 55 in the caulking holding portion 57, the molten low melting point metal 61 flows to the soluble portion 15 through the inclined portion 55, and the melted portion 15 Variations can be eliminated and the fusing characteristics can be stabilized.
In the above modification, the bus bar 13 is bent into a trapezoidal convex shape. However, the upper side portion 13e continuous with the upper portion of the oblique side portion 13d is continuous with the upper surface of the battery as shown by a broken line in FIG. It can also be formed as a parallel plate part.

It is a principal part expansion perspective view of the fuse unit which concerns on this invention. It is a perspective view of the fuse element installed in the fuse unit. 1 is an external perspective view of a fuse unit according to the present invention. It is a side view of the inclined part formed in a bus bar. It is a principal part side view showing the welding condition of the low melting-point metal in this invention. It is a side view of the modification of an inclination part. It is a perspective view of the fusible part in the conventional fuse. FIG. 8 is an enlarged side view of FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Fuse accommodating space 13 Bus bar 13b Bus bar 13d connected to the upper part of an inclined part The oblique side part 13e of the bus bar bent by trapezoid convex shape Upper part 15 Fusible part 17 Fuse element 19 Hinge 21 One board part 23 The other board part 25 , 27 Resin body 51 Fuse unit 53 Bottom surface 55 Inclined portion 57 Caulking holding portion 61 Low melting point metal 61a Base end portion 61b Tip end portion 65 Crank shape portion

Claims (5)

A resin body attached to the upper surface of the battery;
A fuse housing space formed in the resin body and having a bottom surface parallel to the top surface;
A bus bar disposed in the fuse housing space and having a fusible portion at the center;
An inclined portion that is formed at a portion including the soluble portion of the bus bar and gradually floats from the bottom surface;
A caulking holding portion formed on a bus bar connected to an upper portion of the inclined portion;
A low melting point metal in which a base end portion is held by the caulking holding portion and a distal end portion is disposed above the inclined portion;
A fuse unit comprising: The fuse unit according to claim 1,
A fuse unit, wherein a crank-shaped portion is formed at a portion of a bus bar parallel to the upper surface. The fuse unit according to claim 1 or claim 2,
The inclined portion is formed on one oblique side portion of the bus bar that is bent in a heft shape,
The fuse unit, wherein the caulking holding portion is formed on the other oblique side portion of the bus bar. The fuse unit according to claim 1 or claim 2,
The inclined portion is formed on the hypotenuse of the bus bar bent into a trapezoidal convex shape,
The fuse unit, wherein the caulking holding portion is formed on an upper side portion of the bus bar. The fuse unit according to claim 1, wherein:
The fuse element consists of a pair of plates that bend through a hinge,
The bus bar is formed on one plate portion and the resin body is provided,
The other plate body is provided with the other resin body separate from the resin body,
The fuse unit, wherein the one resin body and the other resin body are locked in a state of being bent with the hinge as a boundary.

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