Resistor

Abstract

To provide a resistor which can ensure insulation quality of a resistor element while reducing the number of components.SOLUTION: A resistor 100 comprises: a case 1; and a resistor element 2 having a resistor body 21 which is housed in the case 1, a pair of terminal parts 22 which are provided on the resistor body in such a manner that part of them protrudes from the case 1, and a resistor wire 23 which is wound around the resistor body 21. The resistor body 21 has: a winding core 211 around which the resistor wire 23 is wound; and a pair of terminal installation parts 212 each of which is provided on each of both ends of the winding core 211 so that each of the pair of terminal parts 22 may be installed. Each of the terminal installation parts 212 has a pair of first facing parts 212a each of which faces each of a pair of first peripheral walls 121 of the case 1. The winding core 211 has a pair of lateral flat surfaces 211a each of which faces each of the pair of first peripheral walls 121 and is recessed from each of the pair of first facing parts 212a.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a resistor. [Background technology]

[0002] Patent Document 1 discloses a resistor including a case and a resistive element housed in the case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP2015-135860A Summary of the Invention [Problem to be solved by the invention]

[0004] In the resistor described in Patent Document 1, in order to ensure the insulation of the resistive element from the case (hereinafter, simply referred to as the insulation of the resistive element), it is necessary to provide an insulating plate between the resistive element and the case. Therefore, it is not possible to ensure the insulation of the resistive element while reducing the number of parts constituting the resistor.

[0005] The present invention has been made in view of this problem, and has an object to provide a resistor that can ensure the insulation of the resistive element while reducing the number of parts. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a resistor comprising: a case extending along a longitudinal direction; a resistor housed in the case so as to extend along the longitudinal direction; a pair of terminal portions provided on the resistor so as to protrude from the case; and a resistance wire wound around the resistor, wherein the resistor has a winding core around which the resistance wire is wound and which is formed in a rectangular shape in a cross-sectional view; and a pair of terminal installation portions provided on both ends of the winding core in the longitudinal direction so that each of the pair of terminal portions is provided, each terminal installation portion having a pair of first opposing portions facing each of a pair of side walls of the case, the winding core having a pair of side surfaces facing each of the pair of side walls and recessed from each of the pair of first opposing portions along a width direction perpendicular to the longitudinal direction, and the resistance wire is wound around the pair of side surfaces so as not to come into contact with the pair of side walls. Effect of the Invention

[0007] According to the aspects of the present invention, it is possible to ensure the insulation of the resistance element while reducing the number of parts. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a resistor according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of a case and a fixed piece that constitute the resistor. [Diagram 3] FIG. 3 is a plan view of the resistor. [Figure 4] FIG. 4 is a perspective view of the terminal portion. [Diagram 5] FIG. 5 is a plan view of a resistor having terminal portions provided on both ends. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a plan view of the resistor according to the first embodiment, with the sealing material omitted. [Figure 8] FIG. 8 is a plan view of the resistor according to the first modified example, with the sealing material and the resistance wire omitted. [Figure 9] FIG. 9 is a plan view of the resistor according to the second modification, with the sealing material and the resistance wire omitted. [Figure 10] FIG. 10 is a perspective view of a resistor according to the second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a mode for carrying out the present invention (hereinafter, also simply referred to as an embodiment) will be described with reference to the attached drawings. In this specification, the same elements are given the same reference numerals throughout. In the drawings, the longitudinal direction, width direction, and height direction of the resistor 100 are respectively defined as the direction along the X-axis, the direction along the Y-axis, and the direction along the Z-axis. Hereinafter, for convenience of explanation, the longitudinal direction, width direction, and height direction of the resistor 100 will be simply referred to as the longitudinal direction, width direction, and height direction.

[0010] First, the configuration of a resistor 100 according to this embodiment will be described with reference to FIGS.

[0011] FIG. 1 is a perspective view of a resistor 100 according to this embodiment. FIG. 2 is a perspective view of a case 1 and a fixed piece 4 constituting the resistor 100. FIG. 3 is a plan view of a resistor 21. FIG. 4 is a perspective view of a terminal portion 22. FIG. 5 is a plan view of a resistor 21 provided with terminal portions 22 on both ends. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. FIG. 7 is a plan view of the resistor 100 according to the first embodiment, with the cement material (sealing material) 3 omitted.

[0012] 1 to 7, the resistor 100 according to this embodiment includes a metal case 1, a resistive element 2, a cement material 3 as a sealing material, and a metal fixing piece 4. In this embodiment, the resistor 100 is used as a pre-charge resistor for an electric vehicle, a hybrid vehicle (not shown), etc., in a state where it is mounted on a board or a cooler (not shown) as a mounting part through a screw (not shown) as a screwing member.

[0013] As shown in FIG. 2, the case 1 is a metal case extending along the longitudinal direction (X-axis direction). That is, the longitudinal dimension (size) of the case 1 is larger than the width direction (Y-axis direction). In this embodiment, the case 1 is configured to be octagonal in plan view. The case 1 has a bottom wall 11 formed in an octagonal shape in plan view, a peripheral wall portion 12 provided on the outer periphery of the bottom wall 11, a storage portion 13 surrounded by the bottom wall 11 and the peripheral wall portion 12, and two pairs of step portions 14 protruding from a top surface of the bottom wall 11 facing a resistance element 2 (specifically, a resistor 21 described later / see FIG. 3). In this embodiment, the case 1 is a flat type whose height direction (Z-axis direction) is smaller than its longitudinal and width directions.

[0014] As shown in FIG. 2, the peripheral wall portion 12 has a first peripheral wall 121 (121a, 121b) as a pair of side walls extending along the longitudinal direction, a second peripheral wall 122 (122a, 122b) as a pair of end walls extending along the width direction, a third peripheral wall 123 (123a, 123b) as a pair of connecting walls each connecting one end of the first peripheral wall 121a to one end of the second peripheral wall 122a and connecting the other end of the other first peripheral wall 121b to the other end of the other second peripheral wall 122b, and a fourth peripheral wall 124 (124a, 124b) as a pair of connecting walls each connecting the other end of the first peripheral wall 121a to one end of the other second peripheral wall 122b and connecting one end of the other first peripheral wall 121b to the other end of the second peripheral wall 122a.

[0015] As shown in Fig. 2, the two pairs of step portions 14 are provided so as to be connected to the pair of third peripheral walls 123 (123a, 123b) and the pair of fourth peripheral walls 124 (124a, 124b), respectively. The two pairs of step portions 14 are also arranged along the width direction. The two pairs of step portions 14 are formed so that their thickness in the height direction is larger than the diameter of a resistance wire 23 (see Fig. 7) described later.

[0016] This makes it possible to prevent the resistance wire 23 wound around the resistor 21 (specifically, the bottom surface of the winding core 211 described later) from coming into contact with the bottom wall 11 of the case 1 when the resistor 21 (specifically, a pair of terminal installation portions 212 described later) is placed on the two pairs of step portions 14, thereby ensuring insulation of the resistor element 2 from the bottom wall 11 of the case 1 without providing an insulating plate between the resistor element 2 and the bottom wall 11. As a result, the insulation of the resistor element 2 can be ensured while reducing the number of parts constituting the resistor 100.

[0017] As shown in Fig. 1, Fig. 2 and Fig. 7, the pair of fixing pieces 4 (4a, 4b) are integrally formed with the case 1 so as to sandwich the case 1 in a plan view. In the present embodiment, the pair of fixing pieces 4 (4a, 4b) are formed so as to be connected to both the pair of third peripheral walls 123 (123a, 123b) and the pair of second peripheral walls 122 (122a, 122b). However, the pair of fixing pieces 4 (4a, 4b) is not limited thereto, and may be formed so as to be connected to only the pair of third peripheral walls 123 (123a, 123b), for example.

[0018] Moreover, the pair of fixing pieces 4 (4a, 4b) are molded integrally with the bottom wall 11 of the case 1. The pair of fixing pieces 4 (4a, 4b) are formed so that the thickness in the height direction coincides with the thickness of the bottom wall 11.

[0019] A pair of fixing holes 5 (5a, 5b) penetrating the pair of fixing pieces 4 (4a, 4b) are formed in the pair of fixing pieces 4 (4a, 4b), respectively. The pair of fixing holes 5 (5a, 5b) are for inserting screws therethrough.

[0020] As shown in Figure 7, the resistance element 2 has a resistor 21 accommodated in the accommodating section 13 of the case 1 via cement material 3 (see Figure 1) so as to extend along the longitudinal direction, a pair of terminal portions 22 provided at both ends of the resistor 21 so as to protrude partially from the accommodating section 13 of the case 1, and a metallic resistance wire 23 wound around the resistor 21.

[0021] The resistor 21 is a flat insulator that is generally octagonal in shape and is made of an insulating material such as ceramics. This improves the pulse resistance, making it possible to handle high voltages and reducing the overall thickness and weight of the resistor 100.

[0022] As shown in FIG. 3, the resistor 21 has a winding core 211 around which the resistance wire 23 is wound and which is formed into a rectangular shape in cross section, and a pair of terminal installation portions 212 as both ends of the resistor 21 provided at both ends of the winding core 211 in the longitudinal direction so as to sandwich the winding core 211 along the longitudinal direction.

[0023] The winding core 211 and the pair of terminal installation portions 212 are integrally formed such that the top surfaces of both located on the top side of resistor 21 and the bottom surfaces of both located on the bottom side of resistor 21 are flush with each other. Here, the top side of resistor 21 is the side facing away from bottom wall 11 of case 1, and the bottom side of resistor 21 is the side facing bottom wall 11.

[0024] In order to facilitate winding the resistance wire 23 around the winding core 211, the four corners of the winding core 211 are chamfered or rounded in cross section. As shown in Fig. 7, when the resistor 21 is accommodated in the accommodation section 13 via the cement material 3, a pair of gaps S are formed between the side planes 211a as a pair of side surfaces of the winding core 211 and the inner surfaces of the pair of first peripheral walls 121. As a result, during the manufacture of the resistor 100, the cement material 3 is likely to flow around the outer periphery of the resistor 21 through the pair of gaps S present between the pair of side planes 211a and the pair of first peripheral walls 121, and air is likely to escape, which contributes to the heat dissipation of the entire resistor 100.

[0025] 3 and 7, each terminal installation portion 212 of the resistor 21 is configured to be substantially trapezoidal in plan view, and has a pair of first opposing portions 212a facing the pair of first peripheral walls 121 of the case 1, a pair of second opposing portions 212b facing the pair of second peripheral walls 122 of the case 1, opposing flat surfaces 212c as a pair of third opposing portions that connect the pair of first opposing portions 212a and the pair of second opposing portions 212b and are inclined relative to the pair of side flat surfaces 211a in plan view, a recess 212d located between the pair of second opposing portions 212b and recessed from the second opposing portion 212b along the longitudinal direction, and a pair of accommodating recesses 212e recessed from both the top surface and the bottom surface of the terminal installation portion 212. The recess 212d and the pair of accommodating recesses 212e are accommodating areas for accommodating clips of the terminal portion 22, which will be described later.

[0026] 7, the pair of first opposing portions 212a are provided extending along the longitudinal direction. The winding core 211 is provided such that the pair of side planes 211a face the pair of first circumferential walls 121 and are recessed along the width direction from each of the pair of first opposing portions 212a of the terminal installation portion 212. In other words, the pair of first opposing portions 212a are provided so as to protrude from the pair of side planes 211a, respectively. That is, a step is formed between each of the pair of side planes 211a and each of the pair of first opposing portions 212a.

[0027] In this way, the terminal installation portions 212 provided at both ends of the winding core 211 have a pair of first opposing portions 212a protruding from a pair of side planes 211a, and thus, compared to a case in which the pair of first opposing portions are provided on the winding core 211 rather than on the terminal installation portion 212, it is possible to ensure both a winding region for winding the resistance wire 23 around the winding core 211 and ease of winding. In particular, the resistance wire 23 is wound around the winding core 211 so that the ends (specifically, the pair of ends of the resistance wire 23 welded to the terminal portion 22) are inclined with respect to the width direction in a plan view and come into contact with the top surface of the terminal installation portion 212 (specifically, the region of the top surface of the terminal installation portion 212 excluding the accommodating recess 212e). Therefore, the winding direction of the resistance wire 23 can be changed without applying a load to the resistance wire 23.

[0028] The resistance wire 23 is wound around the pair of side flat surfaces 211a so as not to come into contact with the pair of first peripheral walls 121. In other words, the step is formed so that its dimension (i.e., the amount of recess or protrusion) is larger than the diameter of the resistance wire 23. This ensures insulation of the resistance element 2 from the first peripheral wall 121 of the case 1 without providing an insulating plate between the side flat surfaces 211a and the first peripheral wall 121. As a result, it is possible to ensure insulation of the resistance element 2 while reducing the number of parts constituting the resistor 100.

[0029] In this embodiment, even in a high voltage (e.g., 800V) specification, the dimension (i.e., thickness) of the step is set to 0.8 mm or more, and preferably 1 mm or more, from the viewpoint of ensuring insulation against the first peripheral wall 121 of the case 1. When the dimension of the step is 1 mm or more, the diameter of the resistance wire 23 is set to a maximum of 0.9 mm.

[0030] As shown in Fig. 7, the pair of second opposing portions 212b are provided extending along the width direction. The recessed portion 212d is located at the center in the width direction of the terminal installation portion 212. The pair of recessed portions 212d are provided so that the pair of terminal portions 22 (specifically, the connection pieces 223 described later / see Fig. 4) do not come into contact with the pair of second circumferential walls 122. In other words, the recessed portion 212d is formed so that the recessed amount is larger than the thickness of the terminal portions 22 (specifically, the connection pieces 223).

[0031] This ensures insulation of the resistance element 2 with respect to the second peripheral wall 122 of the case 1 without providing an insulating plate between the second opposing portion 212b and the second peripheral wall 122. As a result, the insulation of the resistance element 2 can be ensured while reducing the number of parts.

[0032] The pair of step portions 14 place the terminal installation portion 212 on either side of the recess 212d in the width direction. In other words, the recess 212d is located between the pair of step portions 14 in a plan view. This makes it possible to prevent the connection piece 223 of the terminal portion 22 provided in the recess 212d from coming into contact with the step portion 14, thereby ensuring insulation of the resistance element 2 from the case 1.

[0033] 7, the two pairs of opposing flat surfaces 212c are provided so as to be able to abut against the pair of third peripheral walls 123 and the pair of fourth peripheral walls 124, respectively. This makes it possible to easily position the resistor 21 relative to the case 1 in the longitudinal and width directions simply by abutting the pair of opposing flat surfaces 212c against the third peripheral wall 123 and the fourth peripheral wall 124.

[0034] As shown in FIG. 7, when the pair of opposing flat surfaces 212c abut against the third circumferential wall 123 and the fourth circumferential wall 124, the pair of first opposing portions 212a are each spaced apart from the first circumferential wall 121, and the pair of second opposing portions 212b are each spaced apart from the second circumferential wall 122.

[0035] As shown in FIG. 3, each of the accommodating recesses 212e is formed to extend along the longitudinal direction so as to communicate with the recess 212d. Each of the accommodating recesses 212e is formed in a rectangular shape in a plan view. The pair of accommodating recesses 212e on the top and bottom surfaces of the terminal installation portion 212 accommodates the terminal portion 22 (specifically, a pair of clamping pieces 222 of the terminal portion 22, which will be described later; see FIG. 4). The accommodating recess 212e on the bottom surface of the terminal installation portion 212 is sandwiched between a pair of step portions 14 along the width direction. In other words, the accommodating recess 212e on the bottom surface of the terminal installation portion 212 and the pair of step portions 14 are provided to overlap along the longitudinal direction. This makes it possible to prevent the other clamping piece 222b accommodated in the accommodating recess 212e on the bottom surface of the terminal installation portion 212 from contacting the step portion 14, thereby ensuring insulation of the resistance element 2 from the case 1.

[0036] 3, the pair of accommodating recesses 212e are sandwiched between the pair of first opposing portions 212a in the width direction. In other words, the pair of accommodating recesses 212e and the pair of first opposing portions 212a are provided so as to overlap in the longitudinal direction. This allows the longitudinal dimension of the terminal installation portion 212 to be smaller than when the pair of accommodating recesses and the pair of first opposing portions are provided so as not to overlap in the longitudinal direction, and therefore allows the longitudinal dimension of the winding core 211 to be relatively larger. As a result, the winding area of ​​the winding core 211 around which the resistance wire 23 is wound can be expanded.

[0037] 3, each accommodating recess 212e is formed with a pair of fall-off prevention recesses 212f arranged along the width direction. That is, the pair of fall-off prevention recesses 212f is concentrated in each accommodating recess 212e. This allows the dimensions (i.e., size) of the terminal portion 22 to be smaller than when the pair of fall-off prevention recesses 212f is directly formed on the top and bottom surfaces of the terminal installation portion 212 where the accommodating recesses 212e are not formed.

[0038] 7, the pair of slip-out prevention recesses 212f are recesses for preventing the terminal portion 22 (specifically, the pair of clamping pieces 222) from slipping out of the resistor 21 (specifically, the terminal installation portion 212). A predetermined distance is provided between the pair of slip-out prevention recesses 212f. In this embodiment, the pair of slip-out prevention recesses 212f are formed in a rectangular shape in a plan view, and are formed closer to the recess 212d side than to the winding core 211 side in the longitudinal direction.

[0039] In the present embodiment, the accommodating recesses 212e are formed on both the top surface and the bottom surface of the terminal installation portion 212, but this is not limiting and, for example, the accommodating recesses 212e may be formed on either the top surface or the bottom surface of the terminal installation portion 212. In this case, a pair of slip-out prevention recesses 212f are directly formed on the other of the top surface and the bottom surface of the terminal installation portion 212 on which the accommodating recesses 212e are not formed.

[0040] As shown in Fig. 7, the pair of terminal portions 22 are arranged in the longitudinal direction and are respectively provided in the pair of terminal installation portions 212. As shown in Fig. 4, each terminal portion 22 has a terminal piece 221 (see Fig. 7) that extends in the height direction and serves as a part protruding from the storage portion 13 (cement material 3) of the case 1, a pair of clamping pieces 222 (222a, 222b) that clamp the top and bottom sides of the terminal installation portion 212, and a connection piece 223 that connects the pair of clamping pieces 222.

[0041] The terminal piece 221, the pair of clamping pieces 222, and the connection piece 223 are formed by cutting and bending a single elastic metal plate (e.g., copper, etc.) having a uniform thickness. This makes it possible to easily form the terminal portion 22.

[0042] 3 and 6, one end of one clamping piece 222a is connected to one end of the other clamping piece 222b by a connection piece 223. In contrast, the other end of one clamping piece 222a is connected to the base end of the terminal piece 221.

[0043] 3 and 6, the pair of clamping pieces 222 and the connecting piece 223 form a clip that is substantially U-shaped in side view or vertical cross section. This allows the terminal portion 22 (specifically, the clip of the terminal portion 22) to be easily provided in the terminal installation portion 212 (specifically, the accommodation region of the terminal installation portion 212) by inserting the pair of clamping pieces 222 into the pair of accommodating recesses 212e so that the opening of the clip faces the recess 212d and the connecting piece 223 approaches the bottom surface of the recess 212d (i.e., the end surface of the resistor 21 / the end surface of the terminal installation portion 212) along the longitudinal direction.

[0044] As shown in Figures 3 and 6, when the terminal portion 22 is provided in the terminal installation portion 212, one clamping piece 222a and the other clamping piece 222b clamp the terminal installation portion 212 so that it is accommodated in a pair of accommodating recesses 212e on the top and bottom surfaces of the terminal installation portion 212, respectively.

[0045] In this embodiment, the thickness of the pair of clamping pieces 222 (i.e., the thickness of the metal plate) is equal to the recessed amount of the pair of accommodating recesses 212e. As a result, one of the clamping pieces 222a accommodated in the accommodating recess 212e is flush with the top surface of the terminal installation portion 212, so that the end of the resistance wire 23 can be placed on both the top surface of the terminal installation portion 212 and the clamping piece 222a without applying excessive force. As a result, the load in the peeling direction (direction perpendicular to the upper surface of the clamping piece 222a / i.e., height direction) on the welding point where the end of the resistance wire 23 and one of the clamping pieces 222a are welded can be reduced.

[0046] As shown in Figures 3 and 6, when the terminal portion 22 is provided in the terminal installation portion 212, one of the clamping pieces 222a that clamps the accommodating recess 212e has a pair of engaging pieces 2222a as engaging portions that partially enter the anti-slip recess 212f formed in the accommodating recess 212e and engage with the anti-slip recess 212f.

[0047] As a result, when terminal portion 22 (specifically, the clip of terminal portion 22) attempts to come out of terminal installation portion 212 (specifically, the storage area of ​​terminal installation portion 212), engagement piece 2222a that has entered anti-slip recess 212f abuts against anti-slip recess 212f, thereby preventing terminal portion 22 (specifically, the clip of terminal portion 22) from coming out of terminal installation portion 212 (specifically, the storage area of ​​terminal installation portion 212).

[0048] Furthermore, since the pair of engaging pieces 2222a are provided on the clamping side of one of the clamping pieces 222a, the clip of the terminal portion 22 is less likely to come out of the accommodation area of ​​the terminal installation portion 212 compared to a pair of engaging pieces provided on a part that does not have a clamping function (e.g., terminal piece 221).

[0049] 3, one of the clamping pieces 222a further has a clamping piece main body 2221a connected to the connection piece 223. The pair of engagement pieces 2222a has a connection region 2222b that is not connected to the connection piece 223 and is connected to the clamping piece main body 2221a, and a bending region 2222c in which a notch is formed between the clamping piece main body 2221a and the connection region 2222b.

[0050] 3, the pair of engaging pieces 2222a are arranged in the width direction so as to sandwich the clamping piece main body 2221a. The connection region 2222b and the bending region 2222c are arranged in the longitudinal direction so that the bending region 2222c is located between the connection region 2222b and the recess 212d.

[0051] As shown in FIG. 6, the bending region 2222c of the engagement piece 2222a is bent toward the anti-slip recess 212f so that its tip as an outer edge facing the second peripheral wall 122 can abut against the vertical wall 212g (i.e., the vertical wall 212g formed closer to the recess 212d side than to the winding core 211 side in the longitudinal direction) adjacent to the end face of the resistor 21 of the anti-slip recess 212f.

[0052] As a result, when the terminal portion 22 (specifically, the clip) attempts to come out of the terminal installation portion 212, the tip of the bent bending region 2222c abuts against the standing wall 212g, thereby preventing the terminal portion 22 from coming out of the terminal installation portion 212.

[0053] As described above, the pair of slip-out prevention recesses 212f are formed in the longitudinal direction closer to the recess 212d than to the winding core 211. This makes it possible to prevent the longitudinal dimension of the engaging piece 2222a from becoming too small, making it difficult to form the engaging piece 2222a, as compared to a case in which the pair of slip-out prevention recesses 212f are formed in the longitudinal direction closer to the winding core 211 than to the recess 212d.

[0054] In this embodiment, the engagement portion is composed of a pair of engagement pieces 2222a, but is not limited to this and may be composed of, for example, a single engagement piece 2222a arranged with the clamping piece main body 2221a along the width direction.

[0055] In addition, in this embodiment, the engagement piece 2222a is provided on the clamping piece 222a having a clamping function, but this is not limited to this, and for example, the engagement piece 2222a may be provided on a terminal piece 221 that does not have a clamping function.

[0056] Moreover, the other clamping piece 222b is similar to the one clamping piece 222a, and therefore a description thereof will be omitted.

[0057] In this embodiment, the engaging piece 2222a is provided on the pair of clamping pieces 222, but is not limited thereto, and may be provided on, for example, one of the clamping pieces 222. In this case, it is sufficient that the slip-out prevention recess 212f is formed only on the side on which the engaging piece 2222a is provided.

[0058] 6, the connection piece 223 is provided so as to be able to come into contact with the bottom surface of the recess 212d, which makes it possible to easily position the terminal portion 22 relative to the terminal installation portion 212 in the longitudinal direction.

[0059] Furthermore, the thickness of the connection piece 223 (i.e., the thickness of the metal plate) is smaller than the recess amount of the recess 212d. This makes it possible to prevent the connection piece 223, which is in contact with the bottom surface of the recess 212d, from protruding from the second opposing portion 212b, and therefore to prevent the connection piece 223 from contacting the second peripheral wall 122. As a result, the insulation of the resistance element 2 from the second peripheral wall 122 of the case 1 can be ensured.

[0060] (Modification) Next, the resistor 100 according to each modification will be described with reference to Fig. 8 to Fig. 10. Note that in the modifications, points that are the same as those in the above-mentioned embodiment will be omitted, and points that are different from the above-mentioned embodiment will be mainly described.

[0061] Fig. 8 is a plan view of resistor 100 according to a first modified example, omitting cement material (sealing material) 3 and resistance wire 23. Fig. 9 is a plan view of resistor 100 according to a second modified example, omitting cement material 3 (sealing material) and resistance wire 23. Fig. 10 is a perspective view of resistor element 21 of the second modified example.

[0062] In the above-described embodiment, the resistor 21 is configured to have an octagonal shape in a plan view, but this is not limited thereto, and may be configured to have, for example, a rectangular shape in a plan view as shown in FIG. 8.

[0063] 8, a first opposing portion 212a protruding in the width direction and a second opposing portion 212b protruding in the longitudinal direction are provided at the four corners of the resistor 21. The first opposing portion 212a and the second opposing portion 212b are connected by an R surface, not by an opposing flat surface 212c.

[0064] 8, the case 1 is configured to have a rectangular shape in a plan view. The pair of first opposing portions 212a are provided so as to be able to come into contact with the pair of first peripheral walls 121, respectively, and the pair of second opposing portions 212b are provided so as to be able to come into contact with the pair of second peripheral walls 122, respectively.

[0065] This makes it easy to position the resistor 21 relative to the case 1 in the longitudinal and width directions simply by abutting the first opposing portion 212a and the second opposing portion 212b against the first peripheral wall 121 and the second peripheral wall 122, respectively.

[0066] Furthermore, the pair of fixing pieces 4 (4a, 4b) are provided so as to sandwich the case 1 along the longitudinal direction. The pair of fixing pieces 4 (4a, 4b) are formed with a pair of fixing holes 5 (5a, 5b) and heat dissipation fins 6. This can improve the heat dissipation of the resistor 100 as a whole.

[0067] In the above embodiment, the resistor 21 is configured so that both the top surface and the bottom surface are flush with each other, but this is not limiting and may be configured, for example, with a stepped structure as shown in Figures 9 and 10. In this case, it is not necessary to provide the two pairs of stepped portions 14 on the bottom wall 11 of the case 1.

[0068] 9 and 10, second step portions 212h are provided as step portions protruding from the top and bottom surfaces at the four corners of the resistor 21. The second step portions 212h are formed to have a thickness larger than the diameter of the resistance wire 23 (see FIG. 7).

[0069] As a result, when resistor 21 around which resistance wire 23 is wound is accommodated in accommodation section 13 of case 1, resistance wire 23 wound on the bottom surface of winding core 211 of resistor 21 can be prevented from contacting bottom wall 11, and insulation of resistance element 2 from bottom wall 11 of case 1 can be ensured without providing an insulating plate between resistance element 2 and bottom wall 11. As a result, insulation of resistance element 2 can be ensured while reducing the number of parts constituting resistor 100.

[0070] (Action and effect) Next, the effects of the embodiment and the modifications will be described.

[0071] The resistor 100 according to the embodiment described above includes a case 1 extending along the longitudinal direction, a resistor 21 housed in the case 1 so as to extend along the longitudinal direction, a pair of terminal portions 22 provided on the resistor 21 so that terminal pieces 221 protrude from the case 1, and a resistance element 2 having a resistance wire 23 wound around the resistor 21. The resistor 21 includes a winding core 211 around which the resistance wire 23 is wound and which is formed into a rectangular shape in a cross section, and a winding core 211 on which the pair of terminal portions 22 are provided. Each terminal installation portion 212 has a pair of first opposing portions 212a facing each of the pair of first peripheral walls 121 of the case 1, and the winding core 211 has a pair of side planes 211a facing each of the pair of first peripheral walls 121 and recessed from each of the pair of first opposing portions 212a along the width direction perpendicular to the longitudinal direction, and the resistance wire 23 is wound around the pair of side planes 211a so as not to come into contact with the pair of first peripheral walls 121.

[0072] In the above-described embodiment, the case 1 is a flat type in which the dimension in the height direction perpendicular to the longitudinal and width directions is smaller than the dimensions in the longitudinal and width directions.

[0073] According to these configurations, the insulation of the resistance element 2 with respect to the first peripheral wall 121 of the case 1 can be ensured without providing an insulating plate between the side flat surface 211a and the first peripheral wall 121. As a result, the insulation of the resistance element 2 can be ensured while reducing the number of parts constituting the resistor 100.

[0074] In addition, during the manufacture of the resistor 100, the cement material 3 easily wraps around the outer periphery of the resistor 21 due to the pair of gaps S that exist between the pair of side planes 211a and the pair of first peripheral walls 121, allowing air to easily escape, thereby contributing to the heat dissipation properties of the entire resistor 100.

[0075] In addition, in the above-described embodiment, each terminal installation portion 212 further has a pair of second opposing portions 212b facing the second peripheral wall 122 of the case 1, and a recess 212d facing the second peripheral wall 122 and recessed in the longitudinal direction from the pair of second opposing portions 212b, and a pair of terminal portions 22 are respectively provided in the pair of recesses 212d so as not to come into contact with the pair of second peripheral walls 122.

[0076] According to this configuration, it is possible to ensure insulation of the resistance element 2 with respect to the second peripheral wall 122 of the case 1 without providing an insulating plate between the second opposing portion 212b and the second peripheral wall 122. As a result, it is possible to ensure insulation of the resistance element 2 while reducing the number of parts.

[0077] In addition, in the above-described embodiment, the case 1 has two pairs of step portions 14 that protrude from the top surface opposite the resistor 21 of the bottom wall 11 of the case 1 and on which a pair of terminal installation portions 212 are placed, and the two pairs of step portions 14 are formed to have a thickness larger than the diameter of the resistance wire 23.

[0078] According to this configuration, when the pair of terminal installation portions 212 are placed on the two pairs of step portions 14, it is possible to prevent the resistance wire 23 wound on the bottom surface of the winding core 211 from contacting the bottom wall 11, and therefore it is possible to ensure insulation of the resistance element 2 from the bottom wall 11 of the case 1 without providing an insulating plate between the resistance element 2 and the bottom wall 11. As a result, it is possible to ensure insulation of the resistance element 2 while reducing the number of parts constituting the resistor 100.

[0079] In addition, in the above-described embodiment, each terminal installation portion 212 is recessed from the bottom surface facing the bottom wall 11 of the case 1 and further has an accommodating recess 212e that accommodates the terminal portion 22, and the pair of step portions 14 sandwich the accommodating recess 212e along the width direction.

[0080] According to this configuration, the other clamping piece 222b accommodated in the accommodating recess 212e on the bottom surface of the terminal installation portion 212 can be prevented from coming into contact with the step portion 14, thereby ensuring insulation of the resistance element 2 from the case 1.

[0081] In addition, in the second modified example described above, each terminal installation portion 212 has a pair of second step portions 212h protruding from the bottom surface of the terminal installation portion 212 that faces the bottom wall 11 of the case 1, and the second step portions 212h are formed to have a thickness larger than the diameter of the resistance wire 23.

[0082] According to this configuration, when resistor 21 around which resistance wire 23 is wound is accommodated in accommodation section 13 of case 1, resistance wire 23 wound on the bottom surface of winding core 211 of resistor 21 can be prevented from contacting bottom wall 11, and therefore insulation of resistance element 2 from bottom wall 11 of case 1 can be ensured without providing an insulating plate between resistance element 2 and bottom wall 11. As a result, insulation of resistance element 2 can be ensured while reducing the number of parts constituting resistor 100.

[0083] In addition, in the above-described embodiment, the case 1 is configured as an octagon when viewed in a plane, and has a pair of third peripheral walls 123 and a pair of fourth peripheral walls 124 that respectively connect the pair of first peripheral walls 121 and the pair of second peripheral walls 122, and each terminal installation portion 212 further has a pair of opposing flat surfaces 212c that respectively connect the pair of first opposing portions 212a and the pair of second opposing portions 212b and are inclined relative to the pair of first opposing portions 212a and the pair of second opposing portions 212b, and the two pairs of opposing flat surfaces 212c are arranged so as to be able to abut against the pair of third peripheral walls 123 and the pair of fourth peripheral walls 124, respectively.

[0084] According to this configuration, simply by abutting the pair of opposing flat surfaces 212c against the third peripheral wall 123 and the fourth peripheral wall 124, the resistor 21 can be easily positioned relative to the case 1 in the longitudinal and width directions.

[0085] In the first and second modified examples described above, the case 1 is configured to be rectangular when viewed in a plane, and the pair of first opposing portions 212a are arranged so as to be able to abut against each of the pair of first peripheral walls 121, and the pair of second opposing portions 212b are arranged so as to be able to abut against each of the pair of second peripheral walls 122.

[0086] According to this configuration, the resistor 21 can be easily positioned in the longitudinal and width directions relative to the case 1 simply by abutting the first opposing portion 212a and the second opposing portion 212b against the first peripheral wall 121 and the second peripheral wall 122, respectively.

[0087] In addition, in the above-described embodiment, the resistance wire 23 is wound around the winding core 211 so that a pair of ends welded to a pair of terminal portions 22, respectively, abut against the top surface of the terminal installation portion 212 and are inclined with respect to the width direction in a plan view.

[0088] According to this configuration, the winding direction of the resistance wire 23 can be changed without applying a load to the resistance wire 23.

[0089] The present embodiment and its modified examples have been described above, but the above-mentioned embodiment and modified examples merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above-mentioned embodiment. [Explanation of symbols]

[0090] 1 case 2. Resistance element 21 Resistor 22 Terminal section 23 Resistance Line 100 resistor 121 1st peripheral wall (side wall) 211 Roll core 211a side 212 Terminal installation section 212a 1st opposing part

Claims

1. A case extending along a longitudinal direction; a resistor element including a resistor housed in the case so as to extend along the longitudinal direction, a pair of terminals provided on the resistor so as to protrude from the case, and a resistor wire wound around the resistor, The resistor is A winding core around which the resistance wire is wound and which is formed into a rectangular shape in cross section; A pair of terminal installation portions provided at both ends of the winding core in the longitudinal direction so that the pair of terminal portions are provided, respectively; having Each terminal installation portion has a pair of first opposing portions that face a pair of side walls of the case, the winding core has a pair of side surfaces that face the pair of side walls and are recessed from the pair of first opposing portions along a width direction perpendicular to the longitudinal direction, The resistance wire is wound around the pair of side surfaces so as not to come into contact with the pair of side walls. resistor.

2. Each terminal installation section is A pair of second opposing portions opposed to the end walls of the case; a recess facing the end wall and recessed from the pair of second opposing portions along the longitudinal direction, A pair of the terminal portions are provided in the pair of recesses so as not to come into contact with the pair of the end walls, 2. The resistor of claim 1.

3. the case has two pairs of step portions protruding from a top surface of a bottom wall of the case facing the resistor and on which a pair of the terminal installation portions are placed, The two pairs of step portions are formed so that their thickness is greater than the diameter of the resistance wire.

3. The resistor of claim 2.

4. Each terminal installation portion further has an accommodation recess recessed from a bottom surface facing the bottom wall of the case and configured to accommodate the terminal portion, The pair of step portions sandwich the accommodating recess in the width direction.

4. The resistor of claim 3.

5. Each terminal installation portion has a pair of step portions protruding from a bottom surface of the terminal installation portion that faces the bottom wall of the case, The pair of step portions are formed to have a thickness larger than a diameter of the resistance wire.

3. The resistor of claim 2.

6. The case is configured in an octagonal shape in a plan view and has two pairs of connecting walls respectively connecting a pair of the side walls and a pair of the end walls, each terminal installation portion further includes a pair of third opposing portions that respectively connect the pair of first opposing portions and the pair of second opposing portions and are inclined with respect to the pair of first opposing portions and the pair of second opposing portions; The two pairs of third opposing portions are provided so as to be able to come into contact with the two pairs of connecting walls, respectively.

3. The resistor of claim 2.

7. The case is rectangular in plan view, The pair of first opposing portions are provided so as to be able to come into contact with the pair of side walls, The pair of second opposing portions are provided so as to be able to come into contact with the pair of end walls, respectively.

3. The resistor of claim 2.

8. The resistance wire is wound around the winding core such that a pair of ends welded to a pair of the terminal portions are inclined with respect to the width direction in a plan view and abut against the top surface of the terminal installation portion.

2. The resistor of claim 1.

9. The case is a flat type having a height dimension perpendicular to the longitudinal direction and the width direction that is smaller than the dimensions in the longitudinal direction and the width direction. A resistor according to any one of claims 1 to 8.

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