JP6199368B2 - Fuse element - Google Patents

Description

  The present invention relates to a fuse element used for protecting various electric circuits of an automobile, for example, and more particularly to a fuse element in which a plurality of fusing parts are arranged in parallel between a pair of terminal parts.

  Conventionally, various types of fuse elements have been adopted as protective elements that quickly shut off a circuit when an unintended high current flows in an electric circuit.

  As one of them, for example, a fuse element 51 incorporated in the in-vehicle fuse 50 of FIG. 10 is known (for example, there are those described in Patent Document 1 and Patent Document 2 as other similar uses). .)

  The in-vehicle fuse 50 includes a cylindrical casing 52 in which a fuse element 51 is accommodated, and arc-extinguishing sand 53 is sealed between the fuse element 51 and the cylindrical casing 52.

  The fuse element 51 located at the center of the casing 52 has terminal portions 54 protruding from both end portions of the cylindrical casing 52. In order to set a large rated current, there is a predetermined distance between the terminal portions 54 and 54. Are integrally connected by four elements 55... 55 arranged in parallel with each other.

  There are various methods for manufacturing this type of fuse element 51. Usually, as shown in FIG. 11, a pair of terminal portions 54 in which a cross-shaped cutout groove 54a is previously formed, and a plurality of methods are provided. The four elongated elements 55 in which the narrow holes 56 are punched to form the narrow fused portions 57 between the small holes 56 are prepared separately, and the element 55 is formed in the cutout groove 54 a of the terminal portion 54. Both end portions 55a and 55a are bent and locked, and the locking portions are fixed by means such as soldering or brazing.

  However, in the conventional method of manufacturing the fuse element 51, the terminal portion 54 is at least cut-off → cut → bend → cut the notch 54a until the element 55 is soldered to the terminal portion 54. The element 55 must be subjected to many processes such as raising, and at least the element 55, such as plate cutting → cutting → formation of the melted portion 57 (punching operation of the small hole 56) → folding operation of both end portions 55a, etc. It had to go through many manufacturing processes.

  In addition, when soldering the element 55 to the terminal portion 54, it is necessary to perform troublesome positioning work such as setting the mutual interval and parallelism of the plurality of elements 55 using a jig or the like (not shown). The work required skill.

  Therefore, in the conventional method for manufacturing the in-vehicle fuse 51 having the plurality of elements 55, much labor and time must be spent on manufacturing the fuse element 51 and its assembling work. This led to a decrease in overall productivity and an increase in cost.

US Pat. No. 4,101,860 (reference numerals 82 and 84 in FIG. 8) US Pat. No. 5,055,817 (reference numerals 30, 32 in FIG. 2)

  Therefore, the present invention was made in view of the problems of such a conventional in-vehicle fuse, and in a fuse element in which a pair of terminal portions are connected by a plurality of elements having a fusing portion at a substantially central portion, By improving the manufacturing process, it is a first object to provide a fuse element in which productivity is remarkably improved and a significant cost reduction can be realized.

  Another object of the present invention is to provide a fuse element that is less susceptible to damage such as cracking or burning due to heat generated from the element when the fuse element is normally energized.

  In order to solve the first problem, a fuse element according to the present invention has terminal portions located at both ends connected by a plurality of elements arranged in parallel at a predetermined adjacent interval, and a substantially central portion of the element. A fuse element provided with a fusing part, wherein at least the element out of the terminal parts of the both end parts and the plurality of elements is punched out of a single metal plate into a predetermined shape into a predetermined three-dimensional shape. It is characterized by being bent (hereinafter, this invention is referred to as “first invention”).

  Here, “terminal portions are arranged in parallel” in the first invention is a broad concept including that the terminal portions are “arranged in parallel”.

  In addition, “one metal plate punched into a predetermined shape and bent into a predetermined three-dimensional shape” does not necessarily refer to a fuse element obtained only by a punching process and a bending process. Of course, there are various steps necessary to manufacture the fuse element, such as the thickness adjustment process, the extension process, and the inspection process performed after the bending process. It is.

  In addition, “the one formed by bending into a predetermined three-dimensional shape” refers to the final three-dimensional shape formed by bending through the above-described steps. Specifically, it means a three-dimensional shape that is folded compactly so that the fuse element can be easily accommodated in the cylindrical casing. This three-dimensional shape is not particularly limited, and includes any shape. For example, the cross-sectional shape of the melted portion may be substantially “self” -shaped, substantially “Z” -shaped, square, circular or the like, and these correspond to Embodiments 1 to 4 described later, respectively.

  In addition, the shape and form of the “terminal part” are not particularly limited, and various types of forms such as a blade-like terminal part and a box-shaped terminal part (plug-in type terminal part) surrounding the terminal at the connection destination are used. Things are included.

  In addition, the “element” in the present invention is a conductive metal portion that connects the terminal portions located at both ends, and when an unintended high current flows through the element in its substantially central portion. It includes a fusing part for quickly interrupting the circuit.

  Further, in the present invention, the “melting part” refers to a substantially central part of the element. The shape and form are not particularly limited in the present invention. For example, the cross-sectional area is made narrow, or the upper part of the narrow part or the vicinity thereof is made of, for example, tin, silver, lead, nickel, or an alloy thereof. Includes deposits of low melting point metals.

  The material of the “terminal portion” and “element” may be a conductive metal. However, as described above, in the present invention, a single metal plate is punched into a predetermined shape, and a predetermined element required as a fuse element is obtained. Since it is formed into a three-dimensional shape, copper or an alloy thereof having both conductivity, bendability and spreadability is preferable.

  In the present invention, it is not always necessary to integrally form the terminal portion and the element with the same metal (base material), and at least the above-mentioned “element” is punched out into a predetermined shape from a single metal plate and has a predetermined three-dimensional shape. What is necessary is just to bend and shape to a target shape.

  Then, it may be integrally connected to a separately prepared terminal portion with a fastening metal fitting such as a screw, bolt or nut, or may be integrally connected by means of soldering, brazing or welding. .

  Here, “predetermined shape” in “punching into a predetermined shape” means “development shape” of the fuse element base material before bending, and the specific shape is the fuse shape. It is specified according to the application, type of fuse element, required rated current, etc. The shape of the developed view of such a fuse element is preferably punched from a single metal plate after cutting with a push tool having a cutting edge corresponding to the developed view, but of course, it is contrary to the process omission. You may punch by dividing the process for each terminal, element, fusing part, etc.

  In view of the technical idea of the present invention, it is most preferable to punch out all of the terminal portion and the plurality of elements from a single metal plate into a predetermined development shape and bend it into a predetermined three-dimensional shape. (This invention is hereinafter referred to as “second invention”).

  After passing through such a punching molding process and a bending molding process, a plurality of elements are arranged in parallel with each other at predetermined adjacent intervals between the terminal portions, so that a parallel circuit of fusing portions is formed between the terminal portions. A fuse element is obtained (hereinafter, this invention is referred to as “third invention”).

  In the third invention, the arrangement of the terminal portions in the first invention described above is “parallel” but is limited to “parallel”.

  The plurality of elements are preferably bent in a direction intersecting the terminal portion direction, and all the elements are preferably folded in the terminal portion direction (hereinafter, this invention is referred to as “fourth invention”). .)

  Here, the relationship between “the bending process is performed in a direction intersecting the terminal portion direction” in the fourth invention and the “bending molding into a predetermined three-dimensional shape” in the first invention described above is as follows. In order to process the final shape of one invention, a plurality of processes are required, but the bending process of the fourth invention shows a specific one of the plurality of processes.

  For this folding process, it is sufficient to simply bend, but for example, a linear or curved folding line may be provided, and the folding may be performed along the folding line.

  In addition, regarding the molding that “all elements are folded in the direction of the terminal portion”, the relationship with “bending molding into a predetermined three-dimensional shape” in the first invention is the final shape of the first invention. It shows a specific one of a plurality of steps required for processing. The reason why all the elements are folded in the direction of the terminal portion is to allow the element to absorb the thermal expansion in the direction of the terminal portion due to the temperature rise when the element is energized.

  By the way, when the element is normally energized, Joule heat is generated from the melted portion because the melted portion has the narrowest cross-sectional area. Therefore, during long-term use, the thermal effect reaches the casing, and the casing may be thermally damaged. In addition, when an unintended high current flows through the fusing part and the fusing part blows, an arc with large heat energy is generated, and the arc-extinguishing sand suppresses this. Burnout or cracking may occur.

  In order to cope with such a situation, the fuse element according to the present invention has a width of the element at a position away from the element located at the center in a state where a plurality of elements are bent into a predetermined three-dimensional shape. It is preferable to make it narrower than the width of the element located at the center (hereinafter, this invention is referred to as “fifth invention”).

  Further, all or some of the plurality of elements constituting the fuse element of the fifth invention described above are folded in the direction of the terminal portion, and the fusing portion of the element at a position away from the element located at the center is provided. Only the fusing width may be narrower than the fusing width of the fusing portion of the element located at the center (hereinafter, this invention is referred to as “sixth invention”).

  As described above, the first to sixth inventions are “manufacturing inventions” called “fuse elements”, but there are two manufacturing processes called “punching process” and “bending molding process” in the invention. In other words, it is a so-called “product-by-process claim” invention, and includes the above two steps as essential constituent elements of the present invention.

  According to the fuse element of the first invention, the plurality of elements including the fusing part are obtained by punching a single metal plate into a predetermined shape and bending it into a predetermined three-dimensional shape. Unlike the element 51 of the conventional fuse element 50 described above, it is not necessary to separately manufacture a pair of terminal portions and four elements including a fusing portion in advance, and both members can be molded simultaneously.

  Further, there is no need for troublesome and complicated operations such as positioning a plurality of elements one by one in the terminal portion and soldering in a state where an accurate positional relationship is ensured.

  Therefore, according to the fuse element of the first invention, the manufacturing process is greatly simplified (the process is omitted), mass production is possible without requiring the skill of an operator, and consequently the fuse element of the present invention. The productivity of fuses that incorporate s is greatly improved.

  In addition, since the pair of terminal portions and the plurality of elements including the fusing portion are integrated from the beginning without interposing the connection work of both members, the dimensional accuracy between the plurality of elements is remarkably high. A fuse element is obtained.

  Further, according to the fuse element of the first invention, since the parallel circuit of the fusing part is formed between the pair of terminal parts, the fusing current is shunted, and hence the arc energy can be suppressed.

  According to the fuse element of the second invention, the members of both the terminal portion and the plurality of elements are formed by bending a single metal plate into a predetermined shape and bending it into a predetermined three-dimensional shape. In addition to the effect, it is possible to obtain a fuse element in which productivity and significant cost reduction are further realized.

  According to the fuse element of the third invention, a fuse element in which a parallel circuit of an arbitrary number of fusing parts is formed between the terminal parts can be easily manufactured at low cost.

  According to the fuse element of the fourth invention, since all the elements are folded in the direction of the terminal portion, it is possible to sufficiently absorb the thermal expansion in the direction of the terminal portion due to the temperature rise when the element is energized. Accordingly, the fusing characteristics of the fuse element are improved, and the life of the fuse element is increased correspondingly.

  According to the fuse element of the fifth invention, among the plurality of elements, the width of the element located away from the element located at the center is narrower than the width of the element located at the center, and Since the element at a position away from the positioned element is bent in the direction intersecting the terminal portion direction, the distance from both ends in the width direction of all the elements to the inner wall surface of the casing becomes equal as a result. .

  Therefore, in addition to the effects of the first to fourth inventions, the amount of arc-extinguishing sand filled from the end in the width direction of the element to the inner wall surface of the casing becomes uniform, improving arc extinguishing performance. Connected. Therefore, the damage to the inner wall surface of the casing due to the Joule heat generated during normal energization generated from the melted portion and the arc during melt cutting is reduced.

  According to the fuse element of the sixth invention, all or a part of the constituent elements of the fuse element of the fifth invention are folded in the direction of the terminal portion, so the heat in the direction of the terminal portion due to the temperature rise when the element is energized Can fully absorb expansion.

  In addition, since the fusing width of the fusing part of the element located away from the element located in the center is narrower than the fusing width of the fusing part of the element located in the middle, as a result, the width direction of all the elements The distance from both ends to the inner wall surface of the casing becomes equal, and the same effect as in the fifth invention is obtained, and the amount of arc-extinguishing sand filled between the end portion of the element and the inner wall surface of the casing is equalized. The arc extinguishing performance is improved.

FIG. 1 is an overall perspective view of a fuse element according to a first embodiment of the present invention. FIG. 2A is a development view of the terminal portion and the element at the time when the punching process and the thickness adjusting process, which are intermediate processes in the manufacturing process of the fuse element of FIG. 1, are performed, and FIG. FIG. 3 is an enlarged cross-sectional view of the fuse element in FIG. FIG. 3 is an overall perspective view of a first modification of the fuse element of FIG. FIG. 4 is an explanatory view of a second modification of the fuse element of FIG. 1, in which FIG. 4 (a) is an overall perspective view, and FIG. 4 (b) is a diagram of the fuse element of FIG. It is the expanded cross-sectional view seen from the line direction. FIG. 5 is an explanatory view of a third modification of the fuse element of FIG. 1, in which FIG. 5 (a) is an overall perspective view thereof, and FIG. 5 (b) is a view of the fuse element of FIG. It is the expanded cross-sectional view seen from the line direction. FIG. 6A is a side view of the bore portion K in FIG. 5A, and FIG. 6B is a plan view thereof. 6C is a side view of another example of the bore portion K, and FIG. 6D is a plan view thereof. FIG. 7A is a development view after the punching process in the manufacturing process of the fuse element according to the second embodiment of the present invention, and FIG. 7B is a diagram after the fuse element of FIG. FIG. 8 is an enlarged cross-sectional view as seen from the XX line direction in FIG. FIG. 8A is a development view after the punching process of the fuse element according to the third embodiment of the present invention, and FIG. 8B is a view after bending the fuse element of FIG. It is the expanded cross-sectional view seen from the YY line direction in a). FIG. 9A is a development view after the punching process of the fuse element according to the fourth embodiment of the present invention, and FIG. 9B is a view after bending the fuse element of FIG. FIG. 9C is an enlarged cross-sectional view as viewed from the direction of the ZZ line in FIG. 9A, and FIG. FIG. 10 is an overall perspective view of the conventional arc-extinguishing sand-containing in-vehicle fuse with a part of the casing portion broken. FIG. 11 is a perspective view illustrating an assembly process of a fuse element used in the in-vehicle fuse of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

<Overall configuration of the present invention>
FIG. 1 is an overall perspective view of a fuse element 10 according to an embodiment of the first invention described above.

  In FIG. 1, a fuse element 10 according to the present embodiment includes a pair of plate-like terminal portions 11, 11 located at both ends, an element 12 connecting the pair of terminal portions 11, 11, It is comprised by the fusing part located in the approximate center part 13. FIG.

  The material of both the terminal portions 11 and 11 and the element 12 is made of copper or a copper alloy which is easily plastically deformed and has excellent bendability and spreadability in this embodiment. It doesn't matter.

  Each of the terminal portions 11, 11 is formed with one mounting hole 11 a to a mounting destination electrical device (not shown). The terminal portion 11 of the present embodiment is a single piece as shown in the figure, but when it is necessary to increase the thickness of the terminal portion 54 like the terminal portion 54 of FIG. These two terminal portions may be created, bent, and overlapped. The development of the terminal portion 54 in this case is, of course, created before bending.

  Returning to FIG. 1, the element 12 has base end portions 15, 15 located at both ends, branch portions 12 a, 12 b branched from the respective base end portions 15, 15, and a space between each branch portion 12 a, 12 b. It is comprised from the element of 3 rows which consists of the lower part, the center part, and the upper elements 12c, 12d, and 12e connected mutually in parallel with H (FIG. 2 (a)). The widths of the three rows of elements 12c, 12d, and 12e are all the same, and the thickness t of the entire element 12 is thinner than the thickness T of the terminal portion 11 (t <T).

  In the present embodiment, the number of columns of the elements 12 is three. However, of course, the number of columns may be two or four or more depending on the use, type, rated current, and the like of the fuse element.

  In the first embodiment, the base end portions 15 and 15 located at both ends of the element 12 are soldered to the adjacent terminal portion 11 by the soldering portion 14, so that both the terminal portions 11 and 11 and the element 12 Are integrally formed.

  However, the connection method between the terminal portions 11 and 11 and the element 12 may be other means such as screwing as described above.

  Therefore, the fuse element 10 according to the first embodiment is obtained by punching at least the element 12 out of a pair of terminal portions 11 and 11 and the elements 12 connected thereto into a predetermined shape from a single metal plate. It is formed by bending into a predetermined three-dimensional shape.

  In the vicinity of the substantially central portion 13, the circular small holes 13 a are punched in two rows, for example, in two in a direction orthogonal to the terminal portions 11, 11 direction, so that the direction orthogonal to the terminal portions 11, 11 direction is obtained. A narrow cut portion is formed. In addition, the fusing part by the small hole method shown in the figure is an example, and it is needless to say that it may be that of another embodiment.

When a high current flows to the substantially central portion 13 of the narrow portion thus obtained for some reason, a passing current per unit cross-sectional area becomes high, so Joule heat and an arc are generated. 13 blows out. In order to promote the low melting point of the copper base material, a low melting point metal made of tin, silver, lead, nickel or an alloy thereof may be deposited in the narrow portion.
<Method for Manufacturing Fuse Element 10 of the Present Invention>
A method of manufacturing the fuse element 10 of FIG. 1 will be described in the order of steps with reference to FIG.

2A is a development view of the terminal portion 11 and the element 12 at the time when the punching process and the thickness adjusting process, which are intermediate processes of the manufacturing process of the fuse element 10 of FIG. 1, are performed, and FIG. FIG. 3 is an enlarged cross-sectional view of the fuse element 10 shown in FIG. 2A as viewed from the direction U-U in FIG.
1. Step of removing the element 12 From a copper plate (or copper alloy plate) (not shown), a plate material having a size slightly larger than the overall size of the element 12 in FIG.
2. Punching process Positioning of the cut copper plate using a device (not shown), automatic positioning is performed using a punching blade (not shown) such as a Thomson blade whose cutting edge has the same shape as the element 12 in FIG. Punching is performed with a punching machine (not shown), and the element 12 having the same shape as the element 12 in FIG. In this case, it is preferable to punch into the shape of the element 12 in FIG. 2A in one step as much as possible. However, if it is difficult, for example, the punching process of the small hole 13a is separated into a plurality of processes in order. You can punch it out.
3. Crease line forming step Although not essential, crease lines L1 and L2 are provided at the right branch portion 12a and the left branch portion 12b, which serve as a guide for the folding position. The element 12 in FIG. 2A represents the state at the completion of this process.
4). Bending process The left and right branch parts 12a and 12b of the element 12 are sequentially bent 90 ° along the crease lines L1 and L2 in the directions of the circles 1 and 2 in the figure, and at the U-U line position after the bending. As shown in FIG. 2B, the cross-sectional shape is bent so as to have a substantially “self” shape.

  Specifically, first, the branch parts 12a and 12b on both sides on the lower element 12c side are counterclockwise by 90 degrees sequentially along the crease lines L1 and L2 of the branch part as shown in FIG. Bend twice. By this treatment, the lower elements 12c are formed which are arranged in parallel with each other at an interval of H adjacent to the central element 12d.

Next or simultaneously with the lower element 12c, the bifurcated portions 12a and 12b on the both sides of the upper element 12e are sequentially turned twice in the counterclockwise direction by 90 degrees along the crease lines L1 and L2 on the branched portions 12a and 12b. Bend it. By this treatment, the upper elements 12e are formed which are arranged in parallel with each other at a distance H adjacent to the central element 12d.
5. Soldering process with both terminal parts 11 and 11 A pair of terminal parts 11 and 11 prepared separately are soldered to the base end parts 15 and 15 of the element 12, respectively.

Through the above manufacturing process, as shown in FIG. 2B, the fuse element 10 having a substantially “self” three-dimensional shape is completed as the cross sections of the elements 12c, 12d, and 12e. Further, after that, necessary processing such as deposit processing (not shown) of the low melting point metal on the substantially central portion 13 described above and inspection is performed.
<Operational effect of the present invention>
According to the fuse element 10 of FIG. 1, the elements 12 arranged in parallel in three rows including the substantially central portion 13 are simultaneously punched into a predetermined shape from a single metal plate into a substantially “self” three-dimensional shape. Since it is bent, there is no need to separately prepare four elements 55 including the fusing part 57, unlike the element 55 of the conventional fuse element 51 described above with reference to FIGS. Further, when soldering to the terminal portion 54, there is no need for positioning work between the terminal portion 54 and the element 55, which is troublesome and requires skill.

  That is, the element 12 including the substantially central portion 13 of the fuse element 10 according to the present invention has a higher degree of processing than both the terminal portions 11 and 11, so that the present invention is only required if the element 12 alone can be mass-produced by simple means. This goal is fully achieved.

  Therefore, according to the fuse element 10 of the first embodiment, the manufacturing process is simplified, and the productivity of the fuse element and the fuse incorporating the fuse element is remarkably improved.

  In addition, since both ends of the three rows of elements 12c, 12d, and 12e including the substantially central portion 13 are connected in parallel from the beginning by the branch portions 12a and 12b, the high-quality fuse element 10 with remarkably high dimensional accuracy. Is obtained.

Further, in the fuse element 10, since a parallel circuit having a substantially central portion 13 is formed between the pair of terminal portions 11, the fusing current is divided. Therefore, arc energy can be suppressed.
<Modification of the present invention>
FIG. 3 is an overall perspective view of a fuse element 10A which is a first modification of the fuse element 10 shown in FIG.

  The fuse element 10A of the first modification is different from the fuse element 10 of FIG. 1 in that all of the terminal portions 11 and 11 and the element 12 are equivalent to a development view of the fuse element 10A of FIG. 3 from a single metal plate. The points 11 and 11 formed by punching the shape and bending it into the three-dimensional shape shown in the figure (second invention) and all three rows of elements 12c, 12d, and 12e constituting the element 12 by raising and lowering the temperature during use. In order to absorb the thermal expansion and contraction in the direction (arrow direction in the figure), the terminal portions 11 and 11 are folded in the direction (the fourth invention).

  The folding line S in the figure is formed as a result of the bending process.

  The fuse element 10A in the embodiment of FIG. 3 is also bent in parallel with each other so that the adjacent intervals of the three rows of elements 12c, 12d, and 12e are H between the terminal portions 11 and 11, similarly to the fuse element 10 of FIG. As a result of the formation, three rows of substantially parallel circuits of the central portion 13 are formed between the terminal portions 11 and 11 (third invention).

  As described above, the number of rows arranged in the substantially central portion 13 of the present embodiment is three rows. However, the number of rows may be four or more as in the third and fourth embodiments described later. Of course.

Next, a method for manufacturing the fuse element 10A of FIG. 3 will be described with reference to FIGS.
1. From the copper plate (or copper alloy plate) (not shown), the overall dimensions of the development of the fuse element 10A in FIG. 2A (ie, all of the terminal portions 11, 11 and the elements 12, 12,...) A plate material having a slightly larger external dimension is cut off.
2. Thickness adjustment process of element 12 With respect to the copper plate chamfered in the previous process, only the portion corresponding to element 12 is beaten with a mechanical hammer (not shown), and the thickness t of element 12 is made thinner than the thickness T of terminal 11 ( <T) Processing (that is, a kind of embossing).
3. Punching process The plate material whose thickness has been adjusted is positioned by an automatic positioning punching machine (not shown), and the planar shape of the blade edge is punched by a punching machine having the entire shape of the fuse element 10A of FIG. A plate material having a shape corresponding to a developed view of the fuse element 10A in a state where the terminal portions 11 and 11 are connected to the base end portions 15 and 15 of the element 12 of a) is punched out. In this case as well, it is preferable to punch into the shape in which the terminal portions 11 and 11 are connected to the base end portions 15 and 15 of the element 12 in FIG. 2A in one step as much as possible. Divide and punch sequentially.
4). Crease line forming step If necessary, crease lines L1 and L2 are attached to the surfaces of the left and right branch parts 12a and 12b.
5. Bending process The left and right branch portions 12a and 12b of the element 12 are sequentially bent along the crease lines L1 and L2 in the direction described above in the direction of the arrow, and the cross-sectional shape at the U-U line position after the bending is shown in FIG. ) And is formed into a substantially three-dimensional shape of “self”.
6). Element folding process In order to absorb thermal expansion in the direction of the terminals 11 and 11 of the element 12 during the temperature rise and fall, the lower, middle and upper elements 12c, 12d and 12e are bent along the crease line S (FIG. 3). As shown in FIG. If possible, this step may be performed simultaneously with the bending step.

  According to the fuse element 10A of FIG. 2 according to the first modification, the base end portions 15 and 15 of the element 12 are simultaneously punched with the terminal portion 11 connected thereto. The manufacturing process is further simplified and the productivity is dramatically improved compared to the fuse element 10 of FIG.

  In addition, the elements 12c, 12d, and 12e are bent in a direction intersecting the terminal portions 11 and 11, and each element is folded in the terminal portions 11 and 11, so that the temperature rises and falls during use. The thermal expansion and thermal contraction in the terminal portions 11 and 11 directions can be absorbed. Therefore, the life of the fuse element is increased by the amount that can absorb the thermal expansion and contraction.

  Next, FIG. 4 is an explanatory diagram of a fuse element 10B according to a second modification of the fuse element 10 of FIG. 1, in which FIG. 4 (a) is an overall perspective view, and FIG. 4 (b) is FIG. 5 is an enlarged cross-sectional view of the fuse element 10B of (a) as viewed from the direction of the line VV passing through the small hole 13a of the substantially central portion 13. FIG.

  As shown in the cross-sectional view of FIG. 4 (b), the second modified example has two flat plates in the vertical position in a state where the cross-sectional shape at the substantially central portion 13 is bent into a substantially “self” shape. By forming the width W1 of the element 12c, 12e narrower than the width W2 of the central flat element 12d (W1 <W2), both end portions of the lower element 12c and the upper element 12e at the substantially central portion 13 are formed. Distances (shortest distances) R, R, R from 6 fusing parts in total including 12c1, 12c1, 12e1, 12e1 and both ends 12d1, 12d1 of the substantially central part 13 of the central element 12d to the casing inner wall surface 52a , R, R, and R are all equal.

  As a configuration condition for that purpose, the adjacent distance H of the three elements 12c, 12d, and 12e is made equal, and the arrangement of the lower element 12c and the upper element 12e is distributed with respect to the center line C.

  As a result, a total of six locations of both end portions 12c1, 12c1, 12d1, 12d1, 12e1, and 12e1 in the substantially central portions 13, 13, and 13 of the lower element 12c, the central element 12d, and the upper element 12e are all casings. 52 is located on a concentric circle P centered on 52 center point O.

  Therefore, according to the fuse element 10B of the second modified example, from both end portions 12c1, 12c1, 12d1, 12d1, 12e1, 12e1 at the substantially central portions 13, 13, 13 of all the elements 12c, 12d, 12e, Since the distances R, R, R, R, R, R to the casing inner wall surface 52a are all equal, the fuse element 10B can be easily accommodated in the casing 52, and the substantially central portions 13, 13, 13 of the casing 52 can be easily accommodated. The thermal effects at the time of energization and fusing given to the casing inner wall surface 52a become uniform.

  Therefore, the casing inner wall surface 52a is less susceptible to damage from the substantially central portions 13, 13, and 13 that are the fusing portions of any of the elements 12c, 12d, and 12e, and has the effect of extending the life of the entire fuse element. .

  Next, FIG. 5 is an explanatory diagram of a fuse element 10C according to a third modification of the fuse element 10 of FIG. 1, in which FIG. 5 (a) is an overall perspective view, and FIG. 5 (b) is FIG. FIG. 4 is an enlarged cross-sectional view of the fuse element 10 </ b> C of (a) as viewed from the direction of the WW line passing through the small hole 13 a in the substantially central portion 13.

  As shown in FIG. 5A, the fuse element 10C according to the third modification includes all of the constituent elements 12c, 12d, and 12e of the fuse element 10B of FIG. 4A according to the second modification described above. The terminal portions 11 and 11 are folded in the direction. As a result, as shown in FIG. 5B, the fuse element 10 </ b> C is entirely displaced upward from the center point O of the casing 52 by the amount of displacement e by the amount of folding.

  However, in this state, both end portions 12e1 and 12e1 of the substantially central portion 13 of the upper element 12e and both end portions 12d1 and 12d1 of the substantially central portion 13 of the central element 12d protrude from the concentric circle P, and are formed on the casing inner wall surface 52a. Because of the approach, the casing inner wall surface 52a is susceptible to thermal damage from these ends.

  Therefore, in order to avoid this, the third modified example has a hollow portion (cutout portion) at both ends 12d1, 12d1, 12e1, and 12e1 of the upper element 12e protruding from the concentric circle P and the substantially central portion 13 of the central element 12d. K is provided to cut out the protruding portion, and the lower element 12c is slightly pushed downward in the drawing to thereby end both ends 12c1, 12c1 at the substantially central portions 13, 13, 13 of all the elements 12c, 12d, 12e. , 12d1, 12d1, 12e1, 12e1 are positioned on a concentric circle P centered on the center point O of the casing 52. In the third modification, the shape of the punched portion K has a width W1 at the position of the substantially central portion 13 of the upper element 12e as shown in the side view of FIG. 6A and the plan view of FIG. 6B. However, the two parallel straight lines are narrower than the width W3 of the branch portions 12a and 12b. However, as shown in the side view of FIG. 6C and the plan view of FIG. 6D, both side surfaces may be formed in a circular arc shape. The same applies to the lower and central elements 12c and 12d.

  Thus, the distance from the end of the element to the inner wall surface of the case changes depending on whether the shape to be folded in the direction of the terminal is a simple bend or a curve, whereby the shape of the bore portion K at the center of the element Will also change.

  As a result of the above treatment, the same distance R as described above is ensured from the both end portions 12c1 to 12e1 of the substantially central portions 13, 13 and 13 of all the elements 12c, 12d and 12e to the casing inner wall surface 52a. Therefore, the casing inner wall surface 52a is not locally damaged by heat.

  Therefore, according to the fuse element 10C according to the third modified example, in addition to the operational effects of the fuse element 10B according to the second modified example described above, thermal expansion in the direction of the terminal portions 11 and 11 due to temperature rise and fall during use It has an effect that can cope with heat shrinkage.

  As shown in FIG. 5A, in the first embodiment, all of the elements 12c, 12d, and 12e constituting the fuse element 10C are folded in the direction of the terminal portions 11 and 11, but the entire fuse element 10C is In consideration of the arrangement posture, the arc generation direction at the time of fusing, etc., that is, for the element most affected by heat, only one or several of the plurality of elements are connected to the terminal portion 11. , 11 may be folded.

  By the way, the fuse elements 10 to 10C of the present invention described with reference to FIGS. 1 to 5 have a three-dimensional shape in which the shape of the cross section is substantially “self”.

  However, the cross-sectional shape of the fuse element of the present invention can be bent into three-dimensional shapes having various cross-sectional shapes in addition to the substantially “self” shape.

  Next, a specific example will be described with reference to FIGS.

  As shown in FIG. 7 (b), the fuse element 20 of the second embodiment is formed by bending the element 12A into a three-dimensional shape having a substantially “Z” cross-sectional shape.

  As described with reference to FIG. 2 (a), the fuse elements 10 and 10A of the first embodiment shown in FIGS. 1 and 2 have the folding lines L1 and L2 such that the lower elements 12c and 12b at the left and right branch portions 12a and 12b It was formed on the extension of the inner and outer faces 12c3, 12e3 of the upper element 12e.

  However, as shown in FIG. 7A, the substantially “Z” cross-sectional shape of the second embodiment is such that the folding lines L3 and L4 of the fuse element 20 are connected to the lower elements 12c at the left and right branch portions 12a and 12b, respectively. The second embodiment is different from the first embodiment in that it is formed on the extension of the middle portion of the center element 12d and on the extension of the middle portion of the center element 12d and the upper element 12e.

  Then, as shown in FIG. 7B, the lower element 12c is 135 ° from the central element 12d in the counterclockwise direction (circle 1 direction in FIG. 7B) around the folding line L3, and the upper element 12e is It can be formed by bending 135 ° in the counterclockwise direction (the two circles in the figure) from the central element 12d around the fold line L4. The lower element 12c and the upper element 12e in the second embodiment are arranged “parallel” at a predetermined adjacent interval H1, but the surface of the central element 12d is not parallel to the above two elements. Since it is inclined at 45 °, it is arranged in the “parallel” relationship defined in the present invention.

  According to the fuse element 20 having the element 12A having a substantially “Z” cross-sectional shape, the number of columns of the element 12A in the first embodiment is the same as that of the element 12A, but is further increased in a casing (not shown). There is an effect that it can be stored compactly.

  Next, as shown in FIG. 8B, the fuse element 30 of the third embodiment is formed by bending so that the cross-sectional shape of the element is a “square” three-dimensional shape.

  As shown in FIG. 8A, the three-dimensional shape of the substantially “square” is similar to the folding lines L3 and L4 of the fuse element 20 of the second embodiment described above with reference to FIG. It can be easily obtained by bending at bending lines L5, L6, and L7 on the intermediate line between the elements 12f to 12i in 12j and 12k.

  The folding order is as follows. First, the folding line L5 at the center of the left and right branch parts 12j, 12k is bent at 90 °, and then, the folding lines L6, L7 on both sides are sequentially centered. It can be easily molded by bending inwardly in the direction indicated by the arrow in the figure.

  According to the fuse element 30 of the third embodiment, the fuse element 30 can be suitably stored in a casing (not shown) having a square cross-sectional shape.

  Next, as shown in FIGS. 9B and 9C, the fuse elements 40 and 40A are formed by bending the cross-sectional shape of the element 12C into three-dimensional shapes of “square” and “substantially circular”, respectively. It is a thing.

  In the fuse elements 10 to 30 of Embodiments 1 to 3 described above, the position of the terminal portion 11 in the developed view is located at the center portion in the longitudinal direction of the branch portions 12a, 12b, 12j, and 12k. As shown in FIG. 7A, the fuse elements 40 and 40A of the third embodiment are different in that the position of the terminal portion 11 is located at the uppermost portion of the branch portions 12s and 12t.

  The fuse element 40 having a square cross-sectional shape in FIG. 9B has the folding lines L8 to L10 on the intermediate line between the elements 12o to 12r at each branch portion, as in the second and third embodiments. And can be easily formed by bending them in the order of 90 ° in the order of circle 1.

  On the other hand, the fuse element 40A having a substantially circular cross-sectional shape in FIG. 9C can be easily formed by gradually bending it in the arrow direction (counterclockwise direction) of the circle 1 in FIG. 9A. it can.

  The fuse elements 40 and 40A of the fourth embodiment can also be suitably housed in a casing having a square or circular cross section. In particular, the fuse element 40A having a substantially circular cross-sectional shape shown in FIG. 9C has a substantially equal distance from the substantially central portions 13, 13... To the casing inner wall surface 52a (not shown). There is an excellent effect that the damage received by the casing due to the Joule heat generated by the portion 13 is the lowest as compared with the other embodiments.

  The fuse elements 10 to 40A of the first to fourth embodiments described above are merely examples, and the fuse elements of the present invention are not limited to these elements without departing from the spirit of the present invention. Modifications and combinations are possible, and these modifications and combinations are also included in the scope of the present invention.

  The use of the fuse element according to the present invention is not limited to the in-vehicle fuse, and can be used for fuses of various applications. Of course, these fuses are also included in the technical scope of the present invention.

10, 10A, 10B, 10C, 20, 30, 40, 40A
Fuse element (present invention)
11 terminal portion 11a mounting hole 12-12C element 12c lower element 12d central element 12e upper element 13 substantially central portion 13a small hole 14 soldering portion 15 base end portion H adjacent interval K punched portion

Claims (3)

A fuse in which terminal portions located at both end portions are connected to a plurality of elements arranged in parallel at a predetermined adjacent interval via a base end portion of the element, and a fusing portion is provided at a substantially central portion of the element An element manufacturing method comprising:
Of the terminal portions at the both ends and the plurality of elements, at least the elements are formed by punching a single metal plate into a predetermined shape and bending it into a predetermined three-dimensional shape,
Between the terminal portions, a plurality of elements are arranged in parallel with each other at a predetermined adjacent interval, and the plurality of elements are connected to a base end portion so that a parallel circuit of the fusing portion is formed between the terminal portions. ,
Further, the connected portion is provided with two crease lines and a flat surface between the two crease lines, and the element has the fold angle so that the bending angle can be changed according to the width of the element. A method of manufacturing a fuse element, wherein bending is performed at the crease line in a direction crossing a terminal portion direction.   2. The fuse element manufacturing method according to claim 1, wherein all of the terminal portion and the plurality of elements are formed by punching a single metal plate into a predetermined shape and bending the metal plate into a predetermined three-dimensional shape. Method.   3. The method of manufacturing a fuse element according to claim 1, wherein all of the plurality of elements are folded in a terminal portion direction. 4.

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