Noise filter

Abstract

To provide a noise filter which has an exhaust heat performance that is higher than that of a conventional one, and can suppress an increase of a temperature even in the case where each part including a conductor is miniaturized.SOLUTION: A noise filter comprises: a magnetic core; a conductor; a mold part; and a thermal conductive part. The mold part is constructed by a first thermal conductive material. The thermal conductive part is constructed by a second thermal conductive material of which a thermal conductive ratio is higher than that of the first thermal conductive material. At the time of a use of the noise filter, it is arranged at a position contacted to an external member that serves as a heat exhaust destination. In the mold part, an open place reaching an outer peripheral surface of a magnetic core is formed while penetrating the mold part. The thermal conductive part includes an entering part entered into the open place, and is configured to be contacted to the magnetic core with the entering part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a noise filter. [Background technology]

[0002] There has been proposed a noise filter as disclosed in the following Patent Document 1. The noise filter described in the following Patent Document 1 includes a magnetic core and a conductor (the conductive bar in the following Patent Document 1), and has a structure in which the magnetic core and the conductor are partly molded with a resin material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-5043 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned noise filter constitutes a part of the power supply path to the motor serving as the power source in, for example, an electric vehicle or a hybrid vehicle. In such applications, a large current flows through the conductor, and the conductor generates a certain amount of heat. If the magnetic core becomes excessively hot due to the heat generated by the conductor, this may adversely affect the performance of the noise filter. Furthermore, if the noise filter becomes excessively hot, this may adversely affect the performance of electronic components, etc., if such components are present near the noise filter. Therefore, it is important to appropriately suppress the heat generated by the noise filter.

[0005] One method for suppressing heat generation in a conductor is, for example, to make the conductor thicker. However, this leads to an increase in the size of the noise filter, making it difficult to place the noise filter in a small space. Furthermore, an increase in the size of the noise filter also leads to an increase in the weight of the device in which the noise filter is installed. Furthermore, an air-cooling mechanism or water-cooling mechanism can be added as a heat countermeasure, but this also requires space to place the air-cooling mechanism or water-cooling mechanism, making it difficult to place it in a small space and resulting in an increase in weight.

[0006] In one aspect of the present disclosure, it is desirable to provide a noise filter that has higher heat dissipation performance than conventional products and is capable of suppressing temperature rise even when each part including a conductor is miniaturized. [Means for solving the problem]

[0007] (1) One aspect of the present disclosure is a noise filter comprising a magnetic core, a conductor, a molded part, and a heat-conducting part. The magnetic core is a magnetic body configured in a ring or cylindrical shape. The conductor is disposed at a position penetrating the inner periphery side of the magnetic core. The molded part is made of a first heat-conducting material and molds a part of the magnetic core and a part of the conductor. The heat-conducting part is made of a second heat-conducting material having a higher thermal conductivity than the first heat-conducting material and is disposed at a position in contact with a part of the magnetic core and a part of the molded part, and is disposed at a position in contact with an external member to which heat is to be exhausted when the noise filter is used, and conducts heat from the magnetic core and the molded part to the external member. The molded part is formed with an opening that penetrates the molded part and reaches the outer periphery of the magnetic core. The heat-conducting part has an inlet that intrudes into the opening and is configured to in contact with the magnetic core at the inlet.

[0008] In the noise filter configured in this manner, the molded part is made of the first thermally conductive material, and the thermal conduction part is made of the second thermally conductive material, so that when the temperatures of the magnetic core and the conductor rise, the heat of the magnetic core and the conductor can be released to the molded part and the thermal conduction part, and the temperature of the magnetic core and the conductor can be prevented from rising excessively.

[0009] In particular, the recess of the heat conductive part is inserted into the opening formed in the molded part and is in contact with the magnetic core, so that the heat of the magnetic core can be directly transferred to the heat conductive part, and the efficiency of heat transfer to the external member to which the heat is dissipated can be improved compared to a location where the molded part is interposed between the magnetic core and the heat conductive part.

[0010] Therefore, since the noise filter's improved heat dissipation performance allows the conductor to generate more heat than in conventional products, it is possible to use conductors that are thinner and more likely to generate heat than in conventional products, thereby enabling the noise filter to be made smaller.

[0011] The noise filter of the present disclosure may further adopt any of the following configurations. (2) In one aspect of the present disclosure, the heat conduction portion may be configured to be in contact with an inner circumferential surface of the opening.

[0012] (3) In one aspect of the present disclosure, the heat conductive portion may be configured to form a gap between the heat conductive portion and an inner circumferential surface of the opening. (4) In one embodiment of the present disclosure, the first thermally conductive material may have a thermal conductivity of 1 W / m·K or more and less than 1.4 W / m·K. The second thermally conductive material may have a thermal conductivity of 1.4 W / m·K or more and 5 W / m·K or less.

[0013] (5) In one aspect of the present disclosure, the heat conductive portion may be configured such that, when the noise filter is in use and is sandwiched between the magnetic core and the molded portion and an external member and subjected to a compressive load, the heat conductive portion deforms and comes into close contact with the external member. [Brief description of the drawings]

[0014] [Figure 1] Fig. 1A is a perspective view of the noise filter of the first embodiment. Fig. 1B is a cross-sectional view of the noise filter of the first embodiment cut at a cut portion indicated by line IB-IB in Fig. 2C. Fig. 1C is a cross-sectional view of the noise filter of the first embodiment cut at a cut portion indicated by line IC-IC in Fig. 2B. [Diagram 2] Fig. 2A is a plan view of the noise filter of the first embodiment, Fig. 2B is a front view of the noise filter of the first embodiment, Fig. 2C is a right side view of the noise filter of the first embodiment, and Fig. 2D is a bottom view of the noise filter of the first embodiment. [Diagram 3] Fig. 3A is a cross-sectional view of the noise filter of the first embodiment cut at the cut portion indicated by the IB-IB line in Fig. 2C and further disassembled to show the heat conductive portion. Fig. 3B is a cross-sectional view of the noise filter of the first embodiment cut at the cut portion indicated by the IC-IC line in Fig. 2B and further disassembled to show the heat conductive portion. Fig. 3C is a perspective view for explaining the use state of the noise filter of the first embodiment. [Figure 4] Fig. 4A is a cross-sectional view of the noise filter of the second embodiment taken along the line IB-IB in Fig. 2C. Fig. 4B is a cross-sectional view of the noise filter of the second embodiment taken along the line IC-IC in Fig. 2B. Fig. 4C is an enlarged view of an IVC portion shown in Fig. 4A. Fig. 4D is an enlarged view of an IVD portion shown in Fig. 4A. Fig. 4E is an enlarged view of an IVE portion shown in Fig. 4B. Fig. 4F is an enlarged view of an IVF portion shown in Fig. 4B. [Diagram 5] Fig. 5A is a perspective view of the noise filter of the third embodiment. Fig. 5B is a cross-sectional view of the noise filter of the third embodiment cut at the cut portion indicated by the line VB-VB in Fig. 6C. Fig. 5C is a cross-sectional view of the noise filter of the third embodiment cut at the cut portion indicated by the line VC-VC in Fig. 6B. [Figure 6]Fig. 6A is a plan view of the noise filter of the third embodiment, Fig. 6B is a front view of the noise filter of the third embodiment, Fig. 6C is a right side view of the noise filter of the third embodiment, and Fig. 6D is a bottom view of the noise filter of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Next, the above-mentioned noise filter will be described with reference to an exemplary embodiment. (1) First embodiment [Noise filter configuration] As shown in Figures 1A, 1B, 1C, 2A, 2B, 2C, and 2D, the noise filter 1 of the first embodiment includes a magnetic core 3, a conductor 5, a molded portion 7, and a heat conductive portion 9. The left side view of the noise filter 1 is the same as the right side view (see Figure 2C). The back view of the noise filter 1 is the same as the front view (see Figure 2B).

[0016] The magnetic core 3 is a magnetic body configured in a ring or cylinder shape as shown in Fig. 1B and Fig. 1C. The conductor 5 is disposed at a position penetrating the inner circumference side of the magnetic core 3 as shown in Fig. 1B and Fig. 1C. In the present embodiment, the conductor 5 is configured as a long and narrow plate in the front-rear direction in the figure, and its plate thickness direction is oriented in the up-down direction in the figure. Near both ends of the conductor 5 in the longitudinal direction (front-rear direction in the figure), through holes 5A and 5B are formed that penetrate in the plate thickness direction.

[0017] The molded section 7 is made of a first thermally conductive material. In the present embodiment, the first thermally conductive material has a thermal conductivity of 1 W / m·K or more and less than 1.4 W / m·K and a volume resistivity of 1.0×10 13 A thermally conductive resin with a thermal conductivity of more than Ω·m (product name: Xecot (registered trademark), manufactured by Unitika Ltd.) is used. The molded part 7 molds a part of the magnetic core 3 and a part of the conductor 5. The space between the inner circumference of the magnetic core 3 and the outer circumference of the conductor 5 is filled with the molded part 7.

[0018] The molded part 7 has fixing parts 11A, 11B that protrude in the left-right direction in the figure. Metallic collars 13A, 13B are provided on the fixing parts 11A, 11B. When the noise filter 1 is fixed to an installation location with a bolt (not shown), the bolt shaft is passed through the collars 13A, 13B.

[0019] The thermally conductive portion 9 is made of a second thermally conductive material having a higher thermal conductivity than the first thermally conductive material. In this embodiment, the second thermally conductive material has a thermal conductivity of 1.4 W / m K or more and 5 W / m K or less, and a volume resistivity of 1.0×10 11 A thermally conductive resin (product name: CPLK, manufactured by Kitagawa Industries Co., Ltd.) having a hardness (ASKER C) of preferably 5 to 50 (more preferably 30 to 50) is used.

[0020] The heat conductive portion 9 is disposed at a position where it contacts a part of the magnetic core 3 and a part of the molded portion 7. More specifically, as shown in FIG. 3A and FIG. 3B, an opening 7A is formed in the molded portion 7. The opening 7A penetrates the molded portion 7 and reaches the outer peripheral surface 3A of the magnetic core 3. The heat conductive portion 9 has an inlet portion 15 that protrudes upward in the figure. The heat conductive portion 9 is configured to contact the magnetic core 3 at a first surface 9A at the tip of the inlet portion 15 in the protruding direction, and to contact the molded portion 7 at a second surface 9B around the inlet portion 15. In addition, in the case of this embodiment, the inlet portion 15 is configured to contact the inner peripheral surface of the opening portion 7A as well.

[0021] When the noise filter 1 is in use, the heat conductive portion 9 is disposed at a position in contact with an external member 17 (e.g., a water-cooled cooling plate) to which heat is to be dissipated, as shown in Fig. 3C, and conducts heat from the magnetic core 3 and the molded portion 7 to the external member 17. When the heat conductive portion 9 is sandwiched between the magnetic core 3 and the molded portion 7 and the external member 17 and receives a compressive load, the heat conductive portion 9 deforms and comes into close contact with the external member 17. This can promote the transfer of heat from the heat conductive portion 9 to the external member 17, compared to when the heat conductive portion 9 does not deform easily.

[0022] In this embodiment, the thermal conductivity of the first thermal conductive material and the second thermal conductive material was measured by a measurement method conforming to ISO22007-2 using a commercially available hot disk method thermal property measuring device (TPS-500, manufactured by Kyoto Electronics Manufacturing Co., Ltd.) The volume resistivity of the first thermal conductive material and the second thermal conductive material was measured by a measurement method conforming to JIS K 6911 using a commercially available high-precision resistivity meter (MCP-HT450, manufactured by Mitsubishi Chemical Corporation).

[0023] [effect] According to the noise filter 1 configured as above, the molded part 7 is made of the first thermally conductive material, and the thermally conductive part 9 is made of the second thermally conductive material. Therefore, when the temperatures of the magnetic core 3 and the conductor 5 rise, the heat of the magnetic core 3 and the conductor 5 can be released to the molded part 7 and the thermally conductive part 9, and the temperatures of the magnetic core 3 and the conductor 5 can be prevented from rising excessively.

[0024] In particular, the recess 15 of the heat conductive part 9 is extended into the opening 7A formed in the molded part 7 and is in contact with the magnetic core 3. Therefore, the heat of the magnetic core 3 can be directly transferred to the heat conductive part 9, and the efficiency of heat transfer to the external member 17, which is the destination of heat discharge, can be improved compared to a location where the molded part 7 is interposed between the magnetic core 3 and the heat conductive part 9.

[0025] In addition, in the present embodiment, the insertion portion 15 is in contact with the inner peripheral surface of the opening portion 7A. Therefore, heat transfer occurs from the molded portion 7 to the heat conductive portion 9 at the inner peripheral surface of the opening portion 7A, and thus it is possible to promote the exhaust of heat from the molded portion 7.

[0026] Therefore, the noise filter 1 has a higher heat dissipation performance, and the temperature rise of the noise filter 1 can be suppressed more than in conventional products. Alternatively, if the temperature rise of the noise filter 1 can be tolerated to the same extent as in conventional products, the conductor 5 can be tolerated to generate more heat than in conventional products. In this case, for example, it is possible to employ a conductor 5 that is thinner and more likely to generate heat than in conventional products, and therefore the noise filter 1 can be made more compact.

[0027] (2) Second embodiment Next, a second embodiment will be described. Each of the second and subsequent embodiments is an embodiment in which a part of the configuration exemplified in the first embodiment is changed. Therefore, the following description will focus on the differences from the first embodiment. The same reference numerals as in the first embodiment are used for the configurations equivalent to those in the first embodiment, and detailed description thereof will be omitted.

[0028] [Noise filter configuration] 4A and 4B, the noise filter 21 of the second embodiment differs from the noise filter 1 of the first embodiment in the structure shown in a cross-sectional view of the noise filter 21. More specifically, the noise filter 21 of the second embodiment differs from the noise filter 1 of the first embodiment in that a gap 23 is provided between the molded portion 7 and the heat conductive portion 9, as shown in FIGS. 4C, 4D, 4E, and 4F.

[0029] In the first embodiment, the gap 23 is formed between the inner circumference of the opening 7A and the outer circumference of the insertion portion 15 shown in Figures 3A and 3B. In the second embodiment, the shapes and dimensions of the magnetic core 3, the conductor 5, and the molded portion 7 are configured to be exactly the same as in the first embodiment. In the second embodiment, the shape and dimensions of the heat conductive portion 9 are configured to be smaller in the front-rear direction and the left-right direction in the figures than those of the insertion portion 15 of the first embodiment shown in Figures 3A and 3B, thereby forming the above-mentioned gap 23.

[0030] Incidentally, even when looking at the external appearance of the noise filter 21 of the second embodiment, the gap 23 is located in a position that cannot be seen. Therefore, a six-sided view of the noise filter 21 of the second embodiment is exactly the same as the six-sided view of the noise filter 1 of the first embodiment.

[0031] [effect] The noise filter 21 configured as above has the same action and effect as the noise filter 1 described in the first embodiment. Therefore, the noise filter 21 has a higher heat dissipation performance, and the temperature rise of the noise filter 21 can be suppressed more than in the conventional product. Alternatively, if the temperature rise of the noise filter 21 can be tolerated to the same extent as in the conventional product, the conductor 5 can be allowed to generate more heat than in the conventional product. In this case, for example, it is possible to employ a conductor 5 that is thinner and more likely to generate heat than in the conventional product, and therefore the noise filter 21 can be made smaller in size.

[0032] In the second embodiment, the noise filter 21 has the gap 23 between the molded portion 7 and the heat conductive portion 9 as described above. Therefore, in the second embodiment, it is easier to fit the insertion portion 15 into the inner periphery of the opening 7A than in the first embodiment, and the productivity of the noise filter 21 can be improved.

[0033] (3) Third embodiment Next, a third embodiment will be described. 5A, 5B, 5C, 6A, 6B, 6C, and 6D, a noise filter 31 of the third embodiment differs from the noise filter 1 of the first embodiment in that it has heat dissipation fins 33A and 33B. The heat dissipation fins 33A and 33B are molded integrally with the molded portion 7 using the first thermally conductive material that constitutes the molded portion 7.

[0034] [effect] The noise filter 31 configured as above has the same action and effect as the noise filter 1 described in the first embodiment. Therefore, the noise filter 31 has a higher heat dissipation performance, and the temperature rise of the noise filter 31 can be suppressed more than in the conventional product. Alternatively, if the temperature rise of the noise filter 31 can be tolerated to the same extent as in the conventional product, the conductor 5 can be allowed to heat up more than in the conventional product. In this case, for example, it is possible to employ a conductor 5 that is thinner and more likely to generate heat than in the conventional product, and therefore the noise filter 31 can be made smaller in size.

[0035] In the third embodiment, the noise filter 31 has the heat dissipation fins 33A and 33B as described above. This can promote heat dissipation from the heat dissipation fins 33A and 33B, and can improve the heat dissipation performance of the noise filter 21 compared to a case where no similar heat dissipation fins are provided.

[0036] (4) Other embodiments Although the noise filter has been described above with reference to exemplary embodiments, the above-described embodiments are merely exemplified as one aspect of the present disclosure. In other words, the present disclosure is not limited to the above-described exemplary embodiments, and can be embodied in various forms without departing from the technical spirit of the present disclosure.

[0037] For example, in the above embodiment, a first thermally conductive material and a second thermally conductive material in which components are blended at a specific composition ratio are exemplified, but the specific components and composition ratios of the first thermally conductive material and the second thermally conductive material are not limited to the above example.

[0038] Further, for example, in the above third embodiment, an example was shown in which heat dissipation fins 33A, 33B were added to both front and rear sides of the molded portion 7, but similar heat dissipation fins may be added to the upper surface side or both left and right sides of the molded portion 7.

[0039] In addition, multiple functions realized by one component exemplified in the above embodiments may be realized by multiple components. One function realized by one component exemplified in the above embodiments may be realized by multiple components. Multiple functions realized by multiple components exemplified in the above embodiments may be realized by one component. One function realized by multiple components exemplified in the above embodiments may be realized by one component. Part of the configuration exemplified in the above embodiments may be omitted. At least part of the configuration exemplified in one of the above embodiments may be added to or replaced with the configuration exemplified in the above embodiments other than that one embodiment.

[0040] (5) Technical Idea Disclosed in This Specification [Item 1] A noise filter, A magnetic core that is a magnetic body configured in an annular or cylindrical shape; a conductor disposed at a position penetrating an inner circumferential side of the magnetic core; a molded portion made of a first thermally conductive material and configured to mold a portion of the magnetic core and a portion of the conductor; a heat conduction section that is made of a second heat conductive material having a higher heat conductivity than the first heat conductive material, that is disposed in a position in contact with a part of the magnetic core and a part of the molded section, and that is disposed in a position in contact with an external member that is a heat dissipation destination when the noise filter is in use, and that conducts heat from the magnetic core and the molded section to the external member; Equipped with The molded portion has an opening formed therein, the opening passing through the molded portion and reaching an outer circumferential surface of the magnetic core, The heat conductive portion has an insertion portion that enters the opening and is configured to contact the magnetic core at the insertion portion. Noise filter.

[0041] [Item 2] Item 1 is a noise filter according to the present invention; The heat conductive portion is configured to be in contact with an inner circumferential surface of the opening portion. Noise filter.

[0042] [Item 3] Item 1 is a noise filter according to the present invention; The heat conductive portion is configured to form a gap between the heat conductive portion and an inner circumferential surface of the opening portion. Noise filter.

[0043] [Item 4] A noise filter according to any one of items 1 to 3, the first thermally conductive material has a thermal conductivity of 1 W / m K or more and less than 1.4 W / m K; The second thermally conductive material has a thermal conductivity of 1.4 W / m K or more and 5 W / m K or less. Noise filter.

[0044] [Item 5] A noise filter according to any one of items 1 to 4, the heat conductive portion is configured to be deformed and come into close contact with the external member when the heat conductive portion is sandwiched between the magnetic core and the molded portion and the external member and receives a compressive load during use of the noise filter. Noise filter. [Explanation of symbols]

[0045] 1, 21, 31...noise filter, 3...magnetic core, 3A...outer surface, 5...conductor, 5A, 5B...through hole, 7...molded portion, 7A...opening portion, 9...thermal conduction portion, 9A...first surface, 9B...second surface, 11A, 11B...fixed portion, 13A, 13B...collar, 15...insertion portion, 17...external member, 23...gap, 33A, 33B...heat dissipation fins.

Claims

1. A noise filter, A magnetic core that is a magnetic body configured in an annular or cylindrical shape; a conductor disposed at a position penetrating an inner circumferential side of the magnetic core; a mold portion that is made of a first thermally conductive material and that molds a part of the magnetic core and a part of the conductor; a heat conduction section that is made of a second heat conductive material having a higher heat conductivity than the first heat conductive material, that is disposed in a position in contact with a part of the magnetic core and a part of the molded section, and that is disposed in a position in contact with an external member that is a heat dissipation destination when the noise filter is in use, and that conducts heat from the magnetic core and the molded section to the external member; Equipped with The molded portion has an opening formed therein, the opening passing through the molded portion and reaching an outer circumferential surface of the magnetic core, The heat conductive portion has an insertion portion that enters the opening and is configured to contact the magnetic core at the insertion portion. Noise filter.

2. 2. The noise filter according to claim 1, The heat conductive portion is configured to be in contact with an inner circumferential surface of the opening portion. Noise filter.

3. 2. The noise filter according to claim 1, The heat conductive portion is configured to form a gap between the heat conductive portion and an inner circumferential surface of the opening portion. Noise filter.

4. The noise filter according to any one of claims 1 to 3, The first thermally conductive material has a thermal conductivity of 1 W / m·K or more and less than 1.4 W / m·K, The second thermally conductive material has a thermal conductivity of 1.4 W / m·K or more and 5 W / m·K or less. Noise filter.

5. The noise filter according to any one of claims 1 to 3, the heat conductive portion is configured to be deformed and come into close contact with the external member when the heat conductive portion is sandwiched between the magnetic core and the molded portion and the external member and receives a compressive load during use of the noise filter. Noise filter.

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