Method for manufacturing a fuse element, a fuse element, and a fuse unit

Abstract

To provide a method for manufacturing a fuse element with excellent versatility. [Solution] The fuse element 10 comprises a conductor 40 made of a metal material and a low-melting-point body 50 made of a low-melting-point metal material having a melting point lower than the melting point of the metal material, and the conductor 40 has a pair of holding parts 42 that are arranged to sandwich a target fusion point 43 in the conductor 40 and are capable of holding the low-melting-point body 50. A manufacturing method for producing the fuse element 10 comprises the steps of selecting either a predetermined first value or a second value smaller than the first value as a target current value at which the target fusion point 43 will fuse, and if the target current value is the first value, providing the low-melting-point body 50 to one of the pair of holding parts 42, or if the target current value is the second value, providing the low-melting-point body 50 to both of the pair of holding parts 42.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a fuse element, a fuse element, and a fuse unit including the fuse element and a housing, the fuse element including a conductor made of a metal material and a low melting point body made of a low melting point metal material having a melting point lower than that of the metal material.

Background Art

[0002] Conventionally, a fuse element has been proposed that includes a conductor made of a metal material (such as copper) and a low melting point body made of a low melting point metal material (such as tin) having a melting point lower than that of the metal material and fixed on the conductor (see, for example, Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The principle of fuse element fusion described above is as follows: First, when an electric current flows through the conductor, the Joule heating generated causes the low-melting-point material to melt before the conductor. When the molten liquid phase of the low-melting-point material comes into contact with the conductor, the metal material constituting the conductor diffuses into the low-melting-point material, even if the conductor itself has not yet reached its melting point. As this diffusion occurs, an alloy layer is formed at the boundary between the two, gradually eroding the conductor until it is finally cut (i.e., fused). Due to this principle of fusion, conventionally, fuse elements with different shapes (especially different target fusion points) were manufactured for each rated current of the fuse element. However, manufacturing many types of fuse elements can lead to increased complexity in each manufacturing process and higher manufacturing costs. Against this backdrop, there is a desire to improve the versatility of fuse elements.

[0005] One of the objectives of the present invention is to provide a method for manufacturing a fuse element with excellent versatility, a fuse element, and a fuse unit using the fuse element. [Means for solving the problem]

[0006] To achieve the aforementioned objectives, the method for manufacturing a fuse element, the fuse element, and the fuse unit according to the present invention are characterized by the following:

[0007] A method for manufacturing a fuse element comprising a conductor made of a metal material and a low-melting-point body made of a low-melting-point metal material having a melting point lower than the melting point of the metal material, The aforementioned conductor is It has a pair of holding parts that are positioned to sandwich the target cutting location of the conductor and are capable of holding the low-melting-point body, The manufacturing method is A step of selecting either a predetermined first value or a second value smaller than the first value as the target current value at which the target cutting location will melt. The process includes the steps of providing the low-melting-point body to one of the pair of holding parts if the target current value is the first value, and providing the low-melting-point body to both of the pair of holding parts if the target current value is the second value. It is a method for manufacturing fuse elements.

[0008] A fuse element comprising a conductor made of a metallic material and a low-melting-point body made of a low-melting-point metallic material having a melting point lower than the melting point of the metallic material, The aforementioned conductor is It has a pair of holding parts that are positioned to sandwich the target cutting location of the conductor and are capable of holding the low-melting-point body, The low melting point body is One or both of the pair of holding parts are provided, It is a fuse element.

[0009] The fuse unit comprises the fuse element described above and a housing that accommodates the fuse element. [Effects of the Invention]

[0010] According to the method for manufacturing a fuse element, the fuse element, and the fuse unit of the present invention, a low-melting-point body is provided on one or both of a pair of holding parts, depending on the magnitude of the target current value (i.e., rated current) at which the target fuse location of the conductor fuses. When the low-melting-point body is provided on one of the holding parts, when the temperature around the target fuse location reaches the melting point of the low-melting-point body due to current being supplied to the fuse element, the molten liquid phase of the low-melting-point body wets and spreads toward the target fuse location, eroding it and causing the fuse to fuse. In this case, the erosion by the low-melting-point body mainly progresses from one side of the target fuse location. On the other hand, when the low-melting-point body is provided on both holding parts, the molten liquid phase of the low-melting-point body wets and spreads toward the target fuse location from one and the other side, eroding it and causing the fuse to fuse. In this case, the erosion by the low-melting-point body progresses from both sides of the target fuse location. Therefore, in the latter case (i.e., when a low-melting-point material is provided in both holding parts), erosion proceeds faster than in the former case (i.e., when a low-melting-point material is provided in one of the holding parts). In other words, in the latter case, compared to the former case, erosion of the target fuse location proceeds appropriately without excessive heating of the target fuse location with a large current. As a result, the target current value at which the target fuse location melts can be reduced in the latter case compared to the former case. In this way, the target current value at which the target fuse location melts can be varied while keeping the shape of the conductor common. Therefore, the manufacturing method of the fuse element of the present invention can manufacture a fuse element with excellent versatility. Similarly, the fuse element and fuse unit of the present invention have excellent versatility.

[0011] The present invention has been briefly described above. Further details of the present invention will be clarified by referring to the accompanying drawings and reading through the embodiments for carrying out the invention described below. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a perspective view showing a fuse unit according to an embodiment of the present invention mounted on a battery. [Figure 2] FIG. 2 is a perspective view showing a fuse element constituting the fuse unit shown in FIG. 1. [Figure 3] FIG. 3 is a perspective view showing an enlarged view of the fuse portion shown in FIG. 2 (however, the description of the low melting point body and the caulking piece for fixing the low melting point body is omitted). [Figure 4] FIG. 4 is a perspective view corresponding to FIG. 3, showing a state where the rated current is a first value (relatively large value) and a low melting point body is provided on one of a pair of holding portions. [Figure 5] FIG. 5 is a perspective view corresponding to FIG. 3, showing a state where the rated current is a second value (relatively small value) and low melting point bodies are provided on both of a pair of holding portions. [Figure 6] FIG. 6 is a cross-sectional view taken along the line A-A of FIG. 4. [Figure 7] FIG. 7 is a cross-sectional view corresponding to FIG. 6 for explaining a state in which erosion of the fuse portion by the low melting point body progresses from the states shown in FIGS. 4 and 6. [Figure 8] FIG. 8 is a cross-sectional view taken along the line B-B of FIG. 5. [Figure 9] FIG. 9 is a cross-sectional view corresponding to FIG. 8 for explaining a state in which erosion of the fuse portion by the low melting point body progresses from the states shown in FIGS. 5 and 8.

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] <Embodiment> Hereinafter, a method for manufacturing a fuse element according to an embodiment of the present invention, the fuse element, and a fuse unit using the fuse element will be described with reference to the drawings.

[0014] As shown in FIG. 1, a fuse unit 1 according to an embodiment of the present invention includes a fuse element 10 and a resin housing 20. The housing 20 is integrally formed (e.g., molded) with the fuse element 10 by a resin material so as to cover (i.e., accommodate) most of the fuse element 10. The fuse unit 1 is mounted and used, for example, on a battery 2 of a vehicle, electrically connects the battery 2 and an electric wire 5 extending from an external load (e.g., electrical components, an alternator, etc.; not shown), and has a function of disconnecting the electrical connection between the battery 2 and the electric wire 5 when a current exceeding the rating flows through the electric wire 5.

[0015] Hereinafter, for convenience of explanation, as shown in FIG. 1 and the like, "front", "rear", "left", "right", "up" and "down" are defined. The "front-rear direction", "left-right direction" and "up-down direction" are orthogonal to each other. Note that the "front-rear direction", "left-right direction" and "up-down direction" are merely defined for convenience of explanation, and do not necessarily correspond to the front-rear direction, left-right direction and up-down direction of the vehicle when the fuse unit 1 is mounted on the vehicle.

[0016] As shown in FIG. 2, the fuse element 10 includes a bus bar 30 (a flat metal member) and a low melting point body 50 disposed in a fuse portion 40 that is a part of the bus bar 30.

[0017] The bus bar 30 includes a battery connection portion 31, an external load connection portion 32, and a fuse portion 40 as a portion (at least partially) exposed to the outside from the housing 20. The plate thickness of the bus bar 30 is constant throughout the entire area in this example. As shown in FIG. 1, a transparent resin cover 21 is provided to cover the fuse portion 40 at the portion of the housing 20 where the fuse portion 40 is exposed in order to protect the fuse portion 40.

[0018] As shown in Figure 1, the flat battery connection portion 31 is connected to the battery 2 via a battery terminal 3 located on the upper surface of the battery 2. Specifically, the battery terminal 3 is connected to a battery post 2a located on the upper surface of the battery 2 and has a cylindrical electrode (stud bolt) 3a. The battery connection portion 31 is fixed to the stud bolt 3a by inserting the stud bolt 3a through a through hole 31a provided in the portion and fastening it with a bolt. In this way, the battery connection portion 31 is fixed in a state in which it is electrically connected to the battery post 2a (and thus to the battery 2) via the battery terminal 3.

[0019] As shown in Figure 1, the flat external load connection part 32 is connected to the external load (not shown) via a terminal part 4 connected to the end of the electric wire 5 extending from the external load. Specifically, the terminal part 4 has a cylindrical electrode (stud bolt) 4a. The stud bolt 4a is inserted through a through hole 32a provided in the external load connection part 32 and fastened with a bolt, thereby fixing the stud bolt 4a in place. As a result, the external load connection part 32 is fixed in a state in which it is electrically connected to the electric wire 5 (and thus to the external load) via the terminal part 4.

[0020] As shown in Figure 2, the battery connection part 31 and the external load connection part 32 are connected via a long, slender, flat fuse part 40 that extends while bending and having a predetermined shape. In other words, the battery 2 and the electric wire 5 (external load) are electrically connected via the fuse part 40.

[0021] The fuse section 40 is elongated and slender, with a smaller current-carrying area (hereinafter referred to as the "current-carrying cross-sectional area") than the other parts of the busbar 30 (i.e., the battery connection section 31 and the external load connection section 32). It is designed to melt due to Joule heating when a current exceeding the rated value flows through it. When the fuse section 40 melts, the electrical connection between the battery connection section 31 and the external load connection section 32 is severed.

[0022] More specifically, as shown in Figure 2, the fuse section 40 has an elongated, roughly rectangular fuse body section 41 that extends in the front-to-back direction. As shown in Figure 3, the fuse body section 41 is provided with a pair of retaining sections 42 that are spaced apart in the direction of extension of the fuse body section 41 (front-to-back direction), and a cutting section 43 that extends in the front-to-back direction to connect the pair of retaining sections 42. The pair of retaining sections 42 are arranged to sandwich the cutting section 43.

[0023] Each retaining portion 42 has a roughly disc-like shape that bulges out on both sides in the width direction (left-right direction) of the fuse body portion 41. A circular through-hole 44 is formed in the center of the retaining portion 42, penetrating the fuse body portion 41 in the thickness direction (up-down direction). A pair of crimping pieces 45 (see Figure 2) are provided on both sides in the width direction. As will be described later, a solid-phase low-melting-point body 50 is provided in one or both of the pair of retaining portions 42 (see Figures 4 and 5). The through-hole 44 and the pair of crimping pieces 45 serve to fix the solid-phase low-melting-point body 50 placed on the retaining portion 42. Specifically, the solid-phase low-melting-point body 50 is placed on the retaining portion 42 so as to cover the front (top) surface (upper) of the retaining portion 42 and so as to fit into the through-hole 44 (see Figures 6 and 8), and is fixed to the retaining portion 42 by the pair of crimping pieces 45 (see Figure 2).

[0024] The material constituting the low-melting-point body 50 (low-melting-point metallic material) is, for example, an alloy mainly composed of tin (Sn). On the other hand, the metallic material constituting the fuse part 40 (busbar 30) is, for example, an alloy mainly composed of copper (Cu). The melting point of the low-melting-point metallic material constituting the low-melting-point body 50 (pure Sn: 232°C) is lower than the melting point of the metallic material constituting the fuse part 40 (pure Cu: 1085°C).

[0025] The width of the fused portion 43 connecting the pair of holding portions 42 is narrower than the width of the other parts of the fuse portion 40. That is, in the fuse portion 40, the fused portion 43 has the smallest current-carrying cross-sectional area. The smaller the current-carrying cross-sectional area, the greater the electrical resistance, and therefore more Joule heat is generated. Thus, when current flows through the fuse portion 40, the temperature of the fused portion 43 becomes higher than the temperature of the other parts of the fuse portion 40. Here, the fused portion 43 corresponds to the "target fused location" of the present invention.

[0026] The principle of fuse section 40 melting is as follows. First, when an electric current flows through the fuse section 40, the low-melting-point material 50 preferentially melts due to the heat generated (Joule heating). When the molten liquid-phase low-melting-point material 50 comes into contact with the fuse section 43, even if the temperature of the fuse section 43 has not reached its melting point, the metal material (Cu) constituting the fuse section 43 diffuses into the liquid-phase low-melting-point material 50 at the point of contact between the fuse section 43 and the liquid-phase low-melting-point material 50. Due to this diffusion, an alloy layer containing Cu and Sn is formed at the point of contact between the fuse section 43 and the liquid-phase low-melting-point material 50. The melting point of this alloy layer is lower than the melting point of the metal material constituting the fuse section 40 (fussing section 43). Therefore, as the alloy layer melts, the aforementioned diffusion of the metal material (Cu) constituting the fused portion 43 into the liquid phase low-melting-point material 50 proceeds at the boundary between the fused portion 43 and the liquid phase low-melting-point material 50 via the alloy layer. In this way, the fused portion 43 is gradually eroded, and finally the fused portion 43 is melted (cut). As described above, when the temperature of the fused portion 43 of the fuse portion 40 reaches the melting point of the low-melting-point material 50 (even if it does not reach the melting point of the metal material constituting the fuse portion 40), the fuse portion 40 can be melted. In other words, the fuse portion 40 can be melted at a more practical temperature (the melting point of the low-melting-point material 50).

[0027] In the manufacturing method of the fuse element 10 according to this embodiment, a solid-phase low-melting-point body 50 is provided on one or both of the pair of holding parts 42, depending on the magnitude of the target current value (i.e., rated current) at which the fused portion 43 (target fused location) of the fuse part 40 will fused. This point will be described in detail below.

[0028] First, let's describe the case where the solid-phase low-melting-point body 50 is provided in one of the pair of holding parts 42, as shown in Figures 4 and 6. In the example shown in Figures 4 and 6, the solid-phase low-melting-point body 50 is provided in the rear holding part 42 of the front and rear pair of holding parts 42 such that it spreads forward from the rear holding part 42 to a point midway along the cutting part 43. In this case, when the temperature of the cutting part 43 of the fuse part 40 (i.e., the highest temperature in the temperature distribution of the fuse part 40) reaches the melting point of the low-melting-point body 50 due to the heat generated (Joule heating) by energizing the fuse element 10, the molten (liquid-phase) low-melting-point body 50 spreads forward on the cutting part 43 (see the white arrow in Figure 7), and as described above, it erodes the cutting part 43 (see the black arrow in Figure 7). In this case, as shown in Figure 7, the erosion of the cut portion 43 by the low-melting-point liquid material 50 mainly progresses from the rear side of the cut portion 43 that comes into contact with the liquid-phase low-melting-point material 50.

[0029] Next, we will describe the case in which the low-melting-point body 50 is provided on both of the pair of holding parts 42, as shown in Figures 5 and 8. In the example shown in Figures 5 and 8, the solid-phase low-melting-point body 50 is provided on both of the front and rear pair of holding parts 42 so as to spread from the rear holding part 42 toward the front and from the front holding part 42 toward the rear, so as to be continuous over the entire front-to-rear area of ​​the cutting part 43. In this case, when the temperature of the cutting part 43 reaches the melting point of the low-melting-point body 50 due to the heat generated (Joule heating) by energizing the fuse element 10, the molten (liquid-phase) low-melting-point body 50 comes into contact with the entire front-to-rear area of ​​the cutting part 43, and as shown by the black arrows in Figure 9, erosion of the cutting part 43 by the low-melting-point body 50 progresses from above the cutting part 43, in addition to both the front and rear sides of the cutting part 43.

[0030] As described above, in the latter case (where the low-melting-point body 50 is provided on both holding parts 42), the surface area of ​​the cutting part 43 in contact with the liquid-phase low-melting-point body 50 is larger than in the former case (where the low-melting-point body 50 is provided on one of the holding parts 42), so the erosion of the cutting part 43 progresses faster, and the cutting (cutting) of the cutting part 43 is completed faster than in the former case. In other words, in the latter case, compared to the former case, the erosion of the cutting part 43 progresses appropriately without excessive heating of the cutting part 43 with a high current. As a result, the target current value (rated current) at which the cutting part 43 melts can be reduced in the latter case compared to the former case. Therefore, by providing the low-melting-point body 50 on one or both of the pair of holding parts 42, the level of the target current value (rated current) at which the cutting part 43 melts can be adjusted without changing the shape of the fuse part 40 (cutting part 43). In this example, the target current value (rated current) can be defined as the magnitude of the current when, for example, current is started to flow to the fuse section 40 from a state where the fuse section 40 is maintained at room temperature, and the time required from the start of current flow until the fuse section 43 is melted (cut) is equal to or within a predetermined specified time.

[0031] Based on the above principles, in the manufacturing method of the fuse element 10 according to this embodiment, first, a predetermined first value or a second value smaller than the first value is selected as the target current value (i.e., rated current) at which the fused portion 43 (target fused location) of the fuse portion 40 will fuse. Next, if the first value is selected as the target current value (rated current), a solid-phase low-melting-point body 50 is provided in one of the pair of holding portions 42, as shown in Figures 4 and 6. If the second value is selected as the target current value (rated current), a solid-phase low-melting-point body 50 is provided in both of the pair of holding portions 42, as shown in Figures 5 and 8. Here, the correlation between the amount of solid-phase low-melting-point body 50 provided in one or both of the pair of holding portions 42 and the first or second value of the target current value (rated current) can be obtained in advance through experiments or the like.

[0032] <Effects and Actions> As described above, according to the manufacturing method of the fuse element 10 according to this embodiment, a low-melting-point body 50 is provided on one or both of the pair of holding parts 42, depending on the magnitude of the target current value (i.e., rated current) at which the target fusion point (fusion part 43) of the conductor (fuse part 40) will fusion. When the low-melting-point body 50 is provided on one of the holding parts 42, when the temperature of the conductor 40 reaches the melting point of the low-melting-point body 50 due to current being supplied to the fuse element 10, the molten (liquid phase) low-melting-point body 50 spreads and wets towards the target fusion point 43, eroding the target fusion point 43 as described above, and the fusion of the target fusion point 43 progresses. In this case, the erosion by the low-melting-point body 50 mainly progresses from one side of the target fusion point 43. On the other hand, when the low-melting-point material 50 is provided in both holding parts 42, the molten (liquid-phase) low-melting-point material 50 wets and spreads toward the target cutting point 43 from one side and the other side of the target cutting point 43, eroding the target cutting point 43 and causing the cutting of the target cutting point 43 to progress. In this case, erosion by the low-melting-point material 50 progresses from both sides of the target cutting point 43. Therefore, in the latter case (when the low-melting-point material 50 is provided in both holding parts 42), the erosion of the target cutting point 43 progresses faster than in the former case (when the low-melting-point material 50 is provided in one of the holding parts 42), and the cutting is completed faster than in the former case. In other words, in the latter case, compared to the former case, the erosion of the target cutting point 43 progresses appropriately without excessive heating of the target cutting point 43 with a high current. As a result, the target current value at which the target fuse point 43 melts can be reduced in the latter case compared to the former case. In this way, the target current value at which the target fuse point 43 melts can be varied while keeping the shape of the conductor common. Therefore, the manufacturing method of the fuse element 10 according to this embodiment can manufacture a fuse element 10 with excellent versatility.

[0033] Furthermore, according to the manufacturing method of the fuse element 10 of this embodiment, when the target current value is the second value, the low-melting-point body 50 is provided not only on both of the pair of holding parts 42 but also on the target fusion point 43. As a result, erosion by the low-melting-point body 50 progresses not only from both sides of the target fusion point 43 but also from above the target fusion point 43. Therefore, the target fusion point 43 can be fused even faster.

[0034] According to the fuse element 10 and fuse unit 1 of this embodiment, by providing a low-melting-point body 50 on one or both of the pair of holding parts 42, the target current value at which the target fuse point 43 melts can be adjusted. Therefore, the fuse element 10 and fuse unit 1 of this embodiment are highly versatile.

[0035] <Other forms> It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the embodiments described above, and can be modified, improved, etc. as appropriate. Furthermore, the material, shape, dimensions, number, placement, etc. of each component in the embodiments described above are arbitrary and not limited as long as they can achieve the present invention.

[0036] For example, in the above embodiment, when the low-melting-point body 50 is provided on both of the pair of holding parts 42, as shown in Figures 5 and 8, the solid-phase low-melting-point body 50 is provided on both of the front and rear pair of holding parts 42 so that it extends from the rear holding part 42 toward the front and from the front holding part 42 toward the rear, and so that it is continuous over the entire front-to-rear area of ​​the cutting part 43. In contrast, when the low-melting-point body 50 is provided on both of the pair of holding parts 42, the solid-phase low-melting-point body 50 may be provided on both of the front and rear pair of holding parts 42 so that it extends from the rear holding part 42 toward the front and from the front holding part 42 toward the rear, and so that it is spaced apart from each other in the front-to-rear center of the cutting part 43. In this case, the molten (liquid phase) low-melting-point material 50 spreads from the rear towards the front on the cutting portion 43, and the low-melting-point material 50 from the front towards the rear on the cutting portion 43, eroding the cutting portion 43 as described above. That is, erosion by the low-melting-point material 50 progresses from both the front and rear sides of the cutting portion 43. Therefore, in this case as well, similar to the embodiments shown in Figures 5 and 8, the erosion of the cutting portion 43 progresses faster compared to the case where the low-melting-point material 50 is provided on one of the holding portions 42 (see Figures 4 and 6), so the target current value (rated current) can be reduced.

[0037] Herein, the features of the embodiments of the fuse element manufacturing method, fuse element, and fuse unit according to the present invention, as described above, are briefly summarized below.

[0038] [1] A method for manufacturing a fuse element (10) comprising a conductor (40) made of a metal material and a low-melting-point body (50) made of a low-melting-point metal material having a melting point lower than the melting point of the metal material, The aforementioned conductor (40) is The conductor (40) has a pair of holding parts (42) that are positioned to sandwich the target cutting location (43) and are capable of holding the low-melting point body (50), The manufacturing method is A step of selecting either a predetermined first value or a second value smaller than the first value as the target current value at which the target cutting location (43) cuts; The process includes the steps of providing the low-melting-point body (50) in one of the pair of holding parts (42) if the target current value is the first value, and providing the low-melting-point body (50) in both of the pair of holding parts (42) if the target current value is the second value. A method for manufacturing a fuse element (10).

[0039] According to the manufacturing method of the fuse element with the configuration described in [1] above, a low-melting-point material is provided on one or both of the pair of holding parts, depending on the magnitude of the target current value (i.e., rated current) at which the target fuse point of the conductor fuses. When the low-melting-point material is provided on one of the holding parts, when the temperature around the target fuse point reaches the melting point of the low-melting-point material due to the energization of the fuse element, the molten liquid phase of the low-melting-point material wets and spreads toward the target fuse point, eroding it and causing the fuse to fuse. In this case, the erosion by the low-melting-point material mainly progresses from one side of the target fuse point. On the other hand, when the low-melting-point material is provided on both holding parts, the molten liquid phase of the low-melting-point material wets and spreads toward the target fuse point from one and the other side, eroding it and causing the fuse to fuse. In this case, the erosion by the low-melting-point material progresses from both sides of the target fuse point. Therefore, in the latter case (i.e., when a low-melting-point material is provided in both holding parts), erosion proceeds faster than in the former case (i.e., when a low-melting-point material is provided in one of the holding parts). In other words, in the latter case, compared to the former case, erosion of the target fuse point proceeds appropriately without excessive heating of the target fuse point with a large current. As a result, the target current value at which the target fuse point melts can be reduced in the latter case compared to the former case. In this way, the target current value at which the target fuse point melts can be varied while keeping the shape of the conductor common. Therefore, the manufacturing method of the fuse element with this configuration can produce a fuse element with excellent versatility.

[0040] [2] In the method for manufacturing the fuse element (10) described in [1] above, If the target current value is the second value, the low melting point body (50) is provided on both of the pair of holding parts (42) and on the target cutting location (43). A method for manufacturing a fuse element (10).

[0041] According to the manufacturing method of the fuse element with the configuration described in [2] above, when the target current value is the second value, a low-melting-point material is provided not only on both of the pair of retaining parts but also on the target fuse point. As a result, erosion by the low-melting-point material progresses from both sides of the target fuse point as well as from above the target fuse point. Therefore, the target fuse point can be fused even faster.

[0042] [3] A fuse element (10) comprising a conductor (40) made of a metal material and a low-melting-point body (50) made of a low-melting-point metal material having a melting point lower than the melting point of the metal material, The aforementioned conductor (40) is The conductor (40) has a pair of holding parts (42) that are positioned to sandwich the target cutting location (43) and are capable of holding the low-melting point body (50), The low melting point body (50) is One or both of the pair of holding parts (42) are provided, Fuse element (10).

[0043] With the fuse element configuration described in [3] above, by providing a low-melting-point material on one or both of the pair of retaining parts, the target current value at which the target fuse fuses can be adjusted. Therefore, the fuse element and fuse unit of this configuration offer excellent versatility.

[0044] [4] A fuse unit (1) comprising the fuse element (10) described in [3] above, and a housing (20) that houses the fuse element (10).

[0045] According to the fuse unit configuration described in [4] above, by providing a low-melting-point material in one or both of the pair of retaining parts, the target current value at which the target fuse location melts can be adjusted. Therefore, the fuse element and fuse unit of this configuration offer excellent versatility. [Explanation of symbols]

[0046] 1 Fuse Unit 10 Fuse element 20 Housing 30 Busbars (conductors) 40 Fuse section (conductor) 42 Holding part 43. Cutting section (target cutting location) 50 Low melting point bodies

Claims

1. A method for manufacturing a fuse element comprising a conductor made of a metal material and a low-melting-point body made of a low-melting-point metal material having a melting point lower than the melting point of the metal material, The aforementioned conductor is It has a pair of holding parts that are positioned to sandwich the target cutting location of the conductor and are capable of holding the low-melting-point body, The manufacturing method is A step of selecting either a predetermined first value or a second value smaller than the first value as the target current value at which the target cutting location will melt, The process includes the steps of providing the low-melting-point body in one of the pair of holding parts if the target current value is the first value, and providing the low-melting-point body in both of the pair of holding parts if the target current value is the second value. A method for manufacturing a fuse element.

2. In the method for manufacturing a fuse element according to claim 1, If the target current value is the second value, the low-melting point body is provided on both of the pair of holding parts and on the target cutting location. A method for manufacturing a fuse element.

3. A fuse element comprising a conductor made of a metallic material and a low-melting-point body made of a low-melting-point metallic material having a melting point lower than the melting point of the metallic material, The aforementioned conductor is It has a pair of holding parts that are positioned to sandwich the target cutting location of the conductor and are capable of holding the low-melting-point body, The low melting point body is One or both of the pair of holding parts are provided, Fuse element.

4. A fuse unit comprising a fuse element according to claim 3 and a housing for housing the fuse element.

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