Vertical fuse

Abstract

To provide a vertical setting fuse capable of minimizing an installation area and by which soldering failures and bonding failures are less likely to occur.SOLUTION: A vertical setting fuse 1 comprises: a cylindrical fuse element 11 that has a virtual center line PL extending in a longitudinal direction; a first cap-like electrode 13 mated and fixed to one end of the fuse element 11; a second cap-like electrode 15 mated and fixed to the other end of the fuse element 11; a first plate-like lead terminal 17; and a second plate-like lead terminal 19. A second plate-like portion 19B and one or more second soldering projections 19D of the second plate-like lead terminal 19 are formed so as not to protrude from a projection range onto a circuit board, of the second cap-like electrode 15.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a vertically mounted fuse and a vertically mounted fuse device that are mounted vertically on the surface of a circuit board. [Background technology]

[0002] 1 and 2 of Japanese Patent Laid-Open No. 8-97002 disclose a conventional vertical fixed resistor that includes a cylindrical fixed resistance element having a virtual center line extending in the longitudinal direction, a first cap-shaped electrode fitted and fixed to one end of the fixed resistance element, a second cap-shaped electrode fitted and fixed to the other end of the fixed resistance element, a first lead terminal connected to an end face of the first cap-shaped electrode, and a second plate-shaped lead terminal connected to an end face of the second cap-shaped electrode, and is mounted vertically on the board surface of a circuit board. The first plate-shaped lead terminal includes a first plate-shaped portion connected to an end face of the first cap-shaped electrode, and a second plate-shaped portion that is continuous with the first plate-shaped portion, extends along the virtual center line with a gap between the fixed resistance element and the second cap-shaped electrode, and has one or more first soldering protrusions at its tip that exceeds the second cap-shaped electrode. The second plate-shaped lead terminal includes a first plate-shaped portion connected to an end face of the second cap-shaped electrode, and a second plate-shaped portion that is continuous with the first plate-shaped portion, extends along the imaginary center line with a gap between the first plate-shaped lead terminal and the tip end of the second plate-shaped portion of the first plate-shaped lead terminal, and has one or more second soldering protrusions at its tip end. The second plate-shaped portion of the second plate-shaped lead terminal is formed in a shape that extends outside the projection range of the second cap-shaped electrode onto the circuit board. In other words, the boundary between the first plate-shaped portion and the second plate-shaped portion of the second plate-shaped lead terminal is located outside the outer periphery of the first cap-shaped electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-97002 Summary of the Invention [Problem to be solved by the invention]

[0004] When the conventional structure is used for a vertically mounted fuse element, the second plate-shaped portion of the second plate-shaped lead terminal is outside the projection range of the second cap-shaped electrode onto the circuit board, making it difficult to reduce the installation area. Furthermore, when a force is applied to the fuse element in the direction toward the circuit board, i.e., in the vertical direction, the force bends the boundary between the first plate-shaped portion and the second plate-shaped portion of the second plate-shaped lead terminal, destroying the joint between the first plate-shaped portion of the second plate-shaped lead terminal and the first cap-shaped electrode. As a result, when the fuse is used on a circuit board that is constantly subjected to vibration, this can cause soldering defects or joint defects.

[0005] An object of the present invention is to provide a vertically mounted fuse that can solve the above problems. [Means for solving the problem]

[0006] The present invention is directed to a vertically mounted fuse that includes a cylindrical fuse element having a virtual center line extending in the longitudinal direction, a first cap-shaped electrode fitted and fixed to one end of the fuse element, a second cap-shaped electrode fitted and fixed to the other end of the fuse element, a first plate-shaped lead terminal connected to an end face of the first cap-shaped electrode, and a second lead terminal connected to an end face of the second cap-shaped electrode, and is mounted vertically on a board surface of a circuit board. In the present invention, the first plate-shaped lead terminal includes a first plate-shaped portion connected to an end face of the first cap-shaped electrode, and a second plate-shaped portion that is continuous with the first plate-shaped portion, extends along the virtual center line with a gap between the fuse element and the second cap-shaped electrode, and has one or more first soldering protrusions at its tip that exceeds the second cap-shaped electrode. The second plate-shaped lead terminal includes a first plate-shaped portion connected to an end face of the second cap-shaped electrode, and a second plate-shaped portion that is continuous with the first plate-shaped portion, extends along the imaginary center line with a gap between the first plate-shaped portion and the end of the second plate-shaped portion of the first plate-shaped lead terminal, and has one or more second soldering protrusions at its end. The second plate-shaped portion and the one or more second soldering protrusions of the second plate-shaped lead terminal do not extend beyond the projection range of the second cap-shaped electrode onto the circuit board, so that the second plate-shaped lead terminal is prevented from being an obstacle to minimizing the installation area of ​​the vertically-mounted fuse. In addition, when the vertically-mounted fuse is mounted on the circuit board, the second plate-shaped portion is structured to support the second cap-shaped electrode under the second cap-shaped electrode, so that even if a vertical force is applied to the mounted fuse, the force does not break the joint between the first plate-shaped portion of the second plate-shaped lead terminal and the second cap-shaped electrode. As a result, according to the present invention, even if the fuse is used on a circuit board that is constantly subjected to vibration, soldering defects or joint defects will not occur.

[0007] It is preferable that the boundary between the first and second plate-like portions of the second plate-like lead terminal is along a chord length assumed for the arc-shaped outer periphery of the end face of the second cap-like electrode and has a length shorter than the chord length, so that the second plate-like portion of the second plate-like lead terminal does not go beyond the projection range of the second cap-like electrode onto the circuit board.

[0008] The length of the boundary between the first and second plate-like portions of the second plate-like lead terminal is preferably 60% to 70% of the diameter of the end face of the second cap-like electrode, in which case the strength of the second plate-like portion of the second plate-like lead terminal is not significantly reduced.

[0009] It is preferable that the first plate-shaped lead terminal and the second plate-shaped lead terminal are arranged so that the second plate-shaped portion of the first plate-shaped lead terminal and the second plate-shaped portion of the second plate-shaped lead terminal are parallel to each other, thereby making it possible to maximize the creepage distance between the second plate-shaped portion of the first plate-shaped lead terminal and the second plate-shaped portion of the second plate-shaped lead terminal. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view of a vertically-mounted fuse according to an embodiment of the present invention, seen obliquely from above; [Diagram 2] FIG. 2 is a perspective view of a vertically-mounted fuse, viewed upside down and at an angle from above. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 2 is a left side view of the vertically-mounted fuse. [Figure 6] FIG. [Figure 7] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vertically-mounted fuse according to the present invention will now be described with reference to the drawings.

[0012] Fig. 1 shows a perspective view of the vertically-placed fuse 1 of this embodiment as seen diagonally from above, Fig. 2 shows a perspective view of the vertically-placed fuse 1 upside down as seen diagonally from above, Fig. 3 shows a front view of the vertically-placed fuse 1, Fig. 4 shows a right side view of the vertically-placed fuse 1, Fig. 5 shows a left side view of the vertically-placed fuse 1, Fig. 6 shows a plan view of the vertically-placed fuse 1, and Fig. 7 shows a bottom view of the vertically-placed fuse 1. Note that these figures do not show the circuit board on which the vertically-placed fuse 1 is mounted.

[0013] The vertically-mounted fuse 1 includes a cylindrical fuse element 11 having an imaginary center line PL extending in the longitudinal direction, a first cap-shaped electrode 13 fitted and fixed to one end of the fuse element 11, a second cap-shaped electrode 15 fitted and fixed to the other end of the fuse element 11, a first plate-shaped lead terminal 17, and a second plate-shaped lead terminal 19. The fuse element 11 includes the first cap-shaped electrode 13 and the second cap-shaped electrode 15 fitted and fixed to the other end of the fuse element 11 inside a cylindrical ceramic case 11A. ofThe first cap-shaped electrode 13 has a known structure in which a fuse conductor connected to the cap-shaped electrode 15 is provided, and the ceramic case 11A is filled with arc-extinguishing sand. The first cap-shaped electrode 13 is formed by pressing a metal plate, and is integrally provided with a cylindrical portion 13A that is fitted to an end of the ceramic case 11A and a disk-shaped end plate 13B that closes one end of the cylindrical portion 13A. An arc-extinguishing sand introduction hole (not shown) is formed in the center of the end plate 13B. A cylindrical portion formed integrally with the center of the first plate-shaped portion 17A of the first plate-shaped lead terminal 17 (described later) is fitted into this arc-extinguishing sand introduction hole (not shown), and the tip of this cylindrical portion is crimped to the back side of the end plate 13B. The first plate-shaped lead terminal 17 is fixed by this crimping and soldering. Arc-extinguishing sand is then introduced into the ceramic case 11A through this cylindrical portion. A sand stopper 21 (described later) is fitted into the inner surface of the cylindrical portion. The second cap-shaped electrode 15, like the first cap-shaped electrode 13, also has a tubular portion 15A and an end plate 15B. A fitting hole (not shown) is formed in the center of the end plate 15B, into which a bottomed tubular portion formed integrally with the center of a second plate-shaped portion 19B of a second plate-shaped lead terminal 19 (described later) is fitted, and the tip of the bottomed tubular portion is crimped to the back side of the end plate 15B. The second plate-shaped lead terminal 19 is fixed by this crimping and soldering.

[0014] The first plate-shaped lead terminal 17 is integrally formed by pressing and bending a metal plate, and includes a first plate-shaped portion 17A, a second plate-shaped portion 17B, and three first soldering protrusions 17D. Two of the three first soldering protrusions 17D at both ends have protrusions 17E protruding outward. These protrusions 17E are provided to prevent the first plate-shaped portion 17A from slipping out of a through-hole for mounting formed in a circuit board (not shown). The first plate-shaped portion 17A is connected to an end surface 13C of the end plate 13B of the first cap-shaped electrode 13. The second plate-shaped portion 17B is continuous with the first plate-shaped portion 17A and extends beyond the second cap-shaped electrode 15 along the imaginary center line PL with a gap between the fuse element 11 and the second cap-shaped electrode 15. The three first soldering protrusions 17D are provided on the tip end 17C of the second plate-shaped portion 17B. D In the present embodiment, a sand stopper 21 is fitted into the cylindrical portion formed integrally with the center of first plate-shaped portion 17A of first plate-shaped lead terminal 17.

[0015] The second plate-shaped lead terminal 19 is also integrally formed by pressing and bending a metal plate, and includes a first plate-shaped portion 19A, a second plate-shaped portion 19B, and three second soldering protrusions 19D. The first plate-shaped portion 19A of the second plate-shaped lead terminal 19 is connected to the end surface 15C of the second cap-shaped electrode 15. The second plate-shaped portion 19B is continuous with the first plate-shaped portion 19A and extends along the imaginary center line PL with a gap between it and the tip portion 17C of the second plate-shaped portion 17B of the first plate-shaped lead terminal 17. In this embodiment, the second plate-shaped lead terminal 19 is integrally provided with three second soldering protrusions 19D to be inserted into mounting through holes provided in a circuit board (not shown). The three second soldering protrusions 19D are provided at intervals in the width direction. Of the three second soldering protrusions 19D, the two first soldering protrusions 19D at both ends have projections 19E protruding outward to prevent the terminal from slipping out of a mounting through-hole formed in a circuit board (not shown).

[0016] In this embodiment, the second plate-like portion 19B of the second plate-like lead terminal 19 is formed so as not to go beyond the projection range of the second cap-like electrode 15 onto a circuit board (not shown). In other words, when the projection range is defined as the range between the shadow of the end face 15C of the second cap-like electrode 15 and the end face 15C, which is formed by irradiating the vertically oriented fuse 1 with light extending straight from above, the second plate-like portion 19B of the second plate-like lead terminal 19 and the three second soldering electrodes 15b, 19b, 19c, 19d, 19e, 19f, 19g, 19h ... protrusionThe shape and position of the second plate-shaped lead terminal 19 are determined so that the projection area 19D does not go beyond this projection area. This prevents the second plate-shaped lead terminal 19 from becoming an obstacle to minimizing the installation area of ​​the vertically-mounted fuse 1. In addition, when the vertically-mounted fuse 1 is mounted on a circuit board, the second plate-shaped portion 19B is structured to support the second cap-shaped electrode 15 below the second cap-shaped electrode 15. Therefore, even if a vertical force is applied to the mounted fuse, the force does not break the joint between the first plate-shaped portion 19A of the second plate-shaped lead terminal 19 and the second cap-shaped electrode 15. As a result, according to the present invention, even if the fuse is used on a circuit board that is constantly subjected to vibration, no soldering or joint failure occurs.

[0017] In this embodiment, the second plate-like portion 19B of the second plate-like lead terminal 19 extends with a gap between it and the tip portion 17C of the second plate-like portion 17B of the first plate-like lead terminal 17 across the imaginary center line PL. That is, the second plate-like portion 19B of the second plate-like lead terminal 19 is not located at a position closer to the tip portion 17C of the second plate-like portion 17B of the first plate-like lead terminal 17 than the center of the end face 15C of the second cap electrode 15. This makes it possible to increase the distance between the first plate-like lead terminal 17 and the second plate-like lead terminal 19, thereby preventing the terminal from becoming vulnerable to lateral impacts.

[0018] 7, in this embodiment, the boundary 19F between the first plate-like portion 19A and the second plate-like portion 19B of the second plate-like lead terminal 19 is along a chord length assumed with respect to the arc-shaped outer periphery of the end face 15C of the second cap-like electrode 15 and has a length shorter than the chord length. That is, the length L of the boundary 19F is shorter than the length SL of the chord length. In this way, the second plate-like portion 19B of the second plate-like lead terminal 19 does not go outside the projection range of the second cap-like electrode 15 onto the circuit board.

[0019] It is preferable that the length L of the boundary 19F between the first plate-like portion 19A and the second plate-like portion 19B of the second plate-like lead terminal 19 is 60% to 70% of the diameter R of the end plate 15B of the second cap-like electrode 15. In this range, the strength of the second plate-like portion 19B of the second plate-like lead terminal 19 is not significantly reduced. In this embodiment, the first plate-like lead terminal 17 and the second plate-like lead terminal 19 are formed of a plate-like member having a substantially constant width. Therefore, the maximum width of the first plate-like portion 19A and the second plate-like portion 19B of the second plate-like lead terminal 19 is the same as the width of the boundary 19F, and the maximum width of the first plate-like portion 17A and the second plate-like portion 17B of the first plate-like lead terminal 17 is also the same as the width of the boundary 19F.

[0020] The first plate-shaped lead terminal 17 and the second plate-shaped lead terminal 19 are arranged so that the second plate-shaped portion 17B of the first plate-shaped lead terminal 17 and the second plate-shaped portion 19B of the second plate-shaped lead terminal 19 are parallel to each other. In this way, the creepage distance between the second plate-shaped portion of the first plate-shaped lead terminal and the second plate-shaped portion of the second plate-shaped lead terminal can be maximized. [Industrial Applicability]

[0021] According to the present invention, the second plate-shaped portion of the second plate-shaped lead terminal does not extend beyond the projection range of the second cap-shaped electrode onto the circuit board, so that the second plate-shaped lead terminal can be prevented from being an obstacle to minimizing the installation area of ​​the vertically-mounted fuse. Furthermore, when the vertically-mounted fuse is mounted on the circuit board, the second plate-shaped portion is structured to support the second cap-shaped electrode below the second cap-shaped electrode, so that even if a vertical force is applied to the mounted fuse, the force does not break the joint between the first plate-shaped portion of the second plate-shaped lead terminal and the second cap-shaped electrode. As a result, according to the present invention, even if the fuse is used on a circuit board that is constantly subjected to vibration, there is no risk of soldering failure or joint failure. [Explanation of symbols]

[0022] 1 Vertical fuse 11 Fuse element 13 First cap-shaped electrode 15 Second cap-shaped electrode 17 First plate-shaped lead terminal 19 Second plate-shaped lead terminal

Claims

1. a cylindrical fuse element having an imaginary centerline extending in a longitudinal direction; a first cap-shaped electrode fixedly fitted to one end of the fuse element; a second cap-shaped electrode fixed to the other end of the fuse element; a first plate-shaped lead terminal connected to an end surface of the first cap-shaped electrode; a second plate-shaped lead terminal connected to an end surface of the second cap-shaped electrode, and the fuse is mounted vertically on a board surface of a circuit board, the first plate-shaped lead terminal comprises a first plate-shaped portion connected to an end surface of the first cap-shaped electrode, and a second plate-shaped portion continuous with the first plate-shaped portion, extending along the imaginary center line with a gap between the fuse element and the second cap-shaped electrode, and having one or more first soldering protrusions at a tip portion extending beyond the second cap-shaped electrode; the second plate-shaped lead terminal comprises a first plate-shaped portion connected to an end surface of the second cap-shaped electrode, and a second plate-shaped portion continuous with the first plate-shaped portion, extending along the imaginary center line with a gap between it and the tip end of the second plate-shaped portion of the first plate-shaped lead terminal, and having one or more second soldering protrusions at a tip end thereof, A vertically-mounted fuse, characterized in that the second plate-shaped portion of the second plate-shaped lead terminal and the one or more second soldering protrusions are formed so as not to extend beyond the projection range of the second cap-shaped electrode onto the circuit board.

2. 2. A vertically-mounted fuse as described in claim 1, wherein the boundary between the first plate-shaped portion and the second plate-shaped portion of the second plate-shaped lead terminal has a length that is along an assumed chord length with respect to the arc-shaped outer peripheral edge of the end face of the second cap-shaped electrode and is shorter than the chord length.

3. A vertically-mounted fuse as described in claim 2, wherein the length dimension of the boundary between the first plate-shaped portion and the second plate-shaped portion of the second plate-shaped lead terminal is 60% to 70% of the diameter of the end face of the second cap-shaped electrode.

4. 3. A vertically-mounted fuse as described in claim 1 or 2, wherein the first plate-shaped lead terminal and the second plate-shaped lead terminal are arranged so that the second plate-shaped portion of the first plate-shaped lead terminal and the second plate-shaped portion of the second plate-shaped lead terminal are parallel to each other.

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