Electronic control unit

Abstract

To improve electromagnetic shielding performance of noise.SOLUTION: An ECU 1 includes an ECU case 2 and heat radiation fins 11 to 16. Each of the heat radiation fins 11 to 16 is formed so that a height from an outer surface changes along an extension direction D1. The ECU case 2 houses a wiring board, on which electronic components are mounted, therein. The multiple heat radiation fins 11 to 16 are installed on an outer surface of the ECU case 2 so as to extend along the preset extension direction D1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electronic control device equipped with heat dissipation fins. [Background technology]

[0002] Patent Document 1 describes a heat sink device equipped with heat dissipation fins. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3405900 Summary of the Invention [Problem to be solved by the invention]

[0004] Metallic housings generally have high heat dissipation and electromagnetic noise shielding properties. However, when a metallic housing is provided with heat dissipation fins to enhance heat dissipation, these fins can act as antennas and impair the electromagnetic noise shielding properties.

[0005] The present disclosure aims to improve electromagnetic shielding against noise. [Means for solving the problem]

[0006] One aspect of the present disclosure is an electronic control device (1) comprising a housing (2) and a plurality of heat dissipation fins (11-16), each of which is formed so that its height from the outer surface varies along the extension direction.

[0007] The housing accommodates a wiring board on which electronic components are mounted. The plurality of heat dissipation fins are arranged on the outer surface of the housing so as to extend along a predetermined extension direction (D1).

[0008] In the electronic control device of the present disclosure configured as above, the height of the heat dissipation fins is not constant along the extension direction. This prevents antennas that resonate at a specific frequency from being formed at multiple locations on the heat dissipation fins, thereby reducing noise intensity. This allows the electronic control device of the present disclosure to improve electromagnetic shielding against noise. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view of the ECU according to the first embodiment. [Figure 2] FIG. 2 is a side view of the ECU according to the first embodiment. [Figure 3] 10A and 10B are diagrams illustrating the generation of noise caused by heat dissipation fins. [Figure 4] 10 is a graph showing frequency dependence of the electric field strength of noise. [Figure 5] FIG. 10 is a side view of an ECU according to a second embodiment. [Figure 6] FIG. 10 is a plan view of an ECU according to a third embodiment. [Figure 7] FIG. 10 is a side view of an ECU according to a third embodiment. [Figure 8] FIG. 10 is a side view of an ECU according to a fourth embodiment. [Figure 9] FIG. 10 is a side view of a heat dissipation fin according to a fifth embodiment. [Figure 10] FIG. 13 is a side view of an ECU according to a sixth embodiment. [Figure 11] FIG. 13 is a front view of an ECU according to a sixth embodiment. [Figure 12] FIG. 13 is a side view of an ECU according to a seventh embodiment. [Figure 13] FIG. 13 is a front view of an ECU according to an eighth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] A first embodiment of the present disclosure will be described below with reference to the drawings. An electronic control unit 1 (hereinafter referred to as ECU1) of this embodiment is mounted on a vehicle and controls, for example, the engine. ECU is an abbreviation for Electronic Control Unit.

[0011] As shown in FIG. 1, the ECU 1 includes an ECU case 2, a mounting portion 3, and a connector 4. The ECU case 2 is a metal member formed in a box shape, and houses therein a wiring board on which various electronic components for controlling the engine are mounted, for example.

[0012] The mounting portion 3 has mounting holes 3a into which bolts for mounting the ECU 1 to the vehicle are inserted, and is fixed to the outer surface of the ECU case 2. The connector 4 has a plurality of terminals for inputting and outputting electrical signals between the wiring board accommodated in the ECU case 2 and the outside of the ECU 1, and is connected to a flexible flat cable.

[0013] The ECU case 2 includes heat dissipation fins 11, 12, 13, 14, 15, and 16. The heat dissipation fins 11 to 16 are plate-shaped metal members that protrude from the outer surface of the ECU case 2. The heat dissipation fins 11 to 16 are installed so as to extend along a predetermined extension direction D1 on the outer surface of the ECU case 2. Furthermore, the heat dissipation fins 11 to 16 are arranged along an arrangement direction D2 that is perpendicular to the extension direction D1.

[0014] The heat dissipation fins 11 to 16 have the same shape and are formed so as to gradually increase in height from the end toward the inside along the extension direction D1, as shown in Fig. 2. For example, in the heat dissipation fin 16, the height H1 near the center is higher than the height H2 near the end.

[0015] The ECU 1 configured as described above includes an ECU case 2 and a plurality of heat dissipation fins 11-16. Each of the plurality of heat dissipation fins 11-16 is formed so that its height from the outer surface varies along the extension direction D1. The ECU case 2 accommodates a wiring board on which electronic components are mounted. The plurality of heat dissipation fins 11-16 are arranged on the outer surface of the ECU case 2 so as to extend along the preset extension direction D1.

[0016] Metal ECU cases generally have high heat dissipation and electromagnetic noise shielding properties. However, when a metal ECU case is equipped with heat dissipation fins to enhance heat dissipation, these fins can act as antennas and impair electromagnetic shielding. Specifically, the ECU case is ideally earthed as a case earth, so that the potential of the ECU case is constant at ground potential. However, protruding parts such as heat dissipation fins have poor earthing properties and can act as antennas.

[0017] To improve heat dissipation, the height of the heat dissipation fins is usually designed to be the maximum height allowed for the ECU case volume. For this reason, as shown in the heat dissipation fin 101 in Figure 3, the height of the heat dissipation fins is generally constant along the extension direction D1.

[0018] If the height of the heat dissipation fin 101 is constant along the extension direction D1, antennas that resonate at a frequency with a wavelength twice the height H101 of the heat dissipation fin 101 are formed at many points on the heat dissipation fin 101, as shown by the current distributions CD1, CD2, CD3, CD4, and CD5 within the heat dissipation fin 101. This increases the electromagnetic noise having a frequency with a wavelength twice the height H101 of the heat dissipation fin 101, resulting in an increase in noise intensity.

[0019] In contrast, in the ECU 1, the heights of the heat dissipation fins 11 to 16 are not constant along the extension direction D1. Therefore, as shown by the current distributions CD11, CD12, CD13, CD14, and CD15 in the heat dissipation fins 11 to 16, it is possible to prevent antennas that resonate at one specific frequency from being formed at many locations on the heat dissipation fins 11 to 16, thereby reducing noise intensity. This allows the ECU 1 to improve its electromagnetic shielding against noise.

[0020] FIG. 4 is a graph showing frequency dependence of the electric field strength of noise in an ECU having heat dissipation fin 101 (hereinafter referred to as a conventional ECU) and an ECU 1 having heat dissipation fins 11 to 16. In FIG. 4, line LN1 indicates the frequency dependence of the electric field strength of noise in the conventional ECU, and line LN2 indicates the frequency dependence of the electric field strength of noise in ECU1.

[0021] As shown in FIG. 4, in both the conventional ECU and ECU1, peaks of the electric field strength occur at frequencies F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, and F13.

[0022] In the conventional ECU, the peaks of the electric field strength at frequencies F1 to F5, F7, F9, F11, and F12 meet the noise test standards, but the peaks of the electric field strength at frequencies F6, F8, and F10 do not meet the noise test standards.Frequencies F8 and F10 are two and three times higher than frequency F6, respectively.

[0023] In contrast, in ECU1, not only the peaks of field strength at frequencies F1 to F5, F7, F9, F11, and F12 but also the peaks of field strength at frequencies F6, F8, and F10 satisfy the noise test standard.

[0024] In the embodiment described above, the ECU case 2 corresponds to a housing. [Second embodiment] A second embodiment of the present disclosure will be described below with reference to the drawings. In the second embodiment, only the parts that are different from the first embodiment will be described. The same reference numerals will be used to designate common components.

[0025] The ECU 1 of the second embodiment differs from the first embodiment in that the shapes of the heat dissipation fins 11 to 16 are changed. The heat dissipation fins 11 to 16 have the same shape and are formed so that the height gradually decreases from the end toward the inside along the extension direction D1, as shown in Fig. 5. For example, in the heat dissipation fin 16, the height H1 near the center is lower than the height H2 near the end.

[0026] The ECU 1 configured as described above includes an ECU case 2 and a plurality of heat dissipation fins 11 to 16. Each of the plurality of heat dissipation fins 11 to 16 is formed so that the height from the outer surface varies along the extension direction D1. As a result, the ECU 1 of the second embodiment can improve the electromagnetic shielding performance against noise, similar to the first embodiment.

[0027] [Third embodiment] A third embodiment of the present disclosure will be described below with reference to the drawings. In the third embodiment, differences from the first embodiment will be described. The same reference numerals will be used to designate common components.

[0028] The ECU 1 of the third embodiment differs from the first embodiment in that the shapes of the heat dissipation fins 12 to 16 are changed. 6, the heat dissipation fins 12 include a heat dissipation fin 12a and a heat dissipation fin 12b. The heat dissipation fins 12a and 12b are installed to extend along the extension direction D1 on the outer surface of the ECU case 2. Furthermore, the heat dissipation fin 12b is arranged to be located on a straight line SL that is parallel to the extension direction D1 and passes through the heat dissipation fin 12a.

[0029] Similarly, the heat dissipation fins 13, 14, 15, and 16 include heat dissipation fins 13a, 14a, 15a, and 16a, and heat dissipation fins 13b, 14b, 15b, and 16b, respectively. Furthermore, the heat dissipation fins 13b, 14b, 15b, and 16b are arranged on a straight line that is parallel to the extension direction D1 and passes through the heat dissipation fins 13a, 14a, 15a, and 16a.

[0030] Here, the lengths of the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, and 16b along the extension direction D1 are defined as L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, and L11, respectively.

[0031] The heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, and 16b are formed so that their lengths L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, and L11 are different from one another.

[0032] As shown in FIG. 7, the heat dissipating fins 12a, 13a, 14a, 15a, 16a and the heat dissipating fins 12b, 13b, 14b, 15b, 16b are formed so as to gradually increase in height from the end portions toward the inside along the extension direction D1.

[0033] In the ECU1 configured in this manner, the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, 16b are formed so that their lengths L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11 along the extension direction D1 are different from each other.

[0034] In this ECU 1, the lengths L1 to L11 of the heat dissipation fins 11 to 16 are not constant. This prevents antennas that resonate at a specific frequency from being formed at many locations on the heat dissipation fins 11 to 16 in the length direction (i.e., extension direction D1) of the heat dissipation fins 11 to 16, thereby reducing noise intensity. This allows the ECU 1 to further improve its electromagnetic shielding against noise.

[0035] Furthermore, heat dissipation fins 12a and 12b are arranged along extension direction D1, heat dissipation fins 13a and 13b are arranged along extension direction D1, heat dissipation fins 14a and 14b are arranged along extension direction D1, heat dissipation fins 15a and 15b are arranged along extension direction D1, and heat dissipation fins 16a and 16b are arranged along extension direction D1. This further prevents antennas that resonate at one specific frequency from being formed at many locations on heat dissipation fins 11 to 16 in ECU 1, thereby further improving electromagnetic shielding against noise.

[0036] [Fourth embodiment] A fourth embodiment of the present disclosure will be described below with reference to the drawings. In the fourth embodiment, only the parts that are different from the third embodiment will be described. The same reference numerals will be used to designate common components.

[0037] The ECU 1 of the fourth embodiment differs from the third embodiment in that the shapes of the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, and 16b are changed.

[0038] As shown in FIG. 8, the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, and 16b are formed so as to gradually become lower from the ends toward the inside along the extension direction D1.

[0039] In the ECU1 configured in this manner, the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, 16b are formed so that their lengths L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11 along the extension direction D1 are different from each other.

[0040] In such an ECU 1, the lengths L1 to L11 of the heat dissipation fins 11 to 16 are not constant, which allows the ECU 1 of the fourth embodiment to further improve the electromagnetic shielding performance against noise, similar to the third embodiment.

[0041] [Fifth embodiment] A fifth embodiment of the present disclosure will be described below with reference to the drawings. In the fifth embodiment, only the parts that are different from the first embodiment will be described. The same reference numerals will be used to designate common components.

[0042] The ECU 1 of the fifth embodiment differs from the first embodiment in that the shapes of the heat dissipation fins 12, 14, and 16 are changed. 9, the heat dissipation fins 11, 13, and 15 are formed so that they gradually become higher from the end portions toward the inside along the extension direction D1, and the heat dissipation fins 12, 14, and 16 are formed so that they gradually become lower from the end portions toward the inside along the extension direction D1.

[0043] The ECU 1 configured in this manner can further prevent antennas that resonate at one specific frequency from being formed at many locations on the heat dissipation fins 11 to 16, thereby further improving the electromagnetic shielding performance against noise.

[0044] [Sixth embodiment] A sixth embodiment of the present disclosure will be described below with reference to the drawings. In the sixth embodiment, differences from the first embodiment will be described. The same reference numerals will be used to designate common components.

[0045] The ECU 1 of the sixth embodiment differs from the first embodiment in that the shapes of the heat dissipation fins 11 to 16 are changed. As shown in Figures 10 and 11, if the heights of the highest points of the heat dissipation fins 11 to 16 are defined as maximum heights TH1, TH2, TH3, TH4, TH5, and TH6, the heat dissipation fins 11 to 16 are formed so that the maximum heights TH1 to TH6 are different from one another.

[0046] The ECU 1 configured in this manner can further prevent antennas that resonate at one specific frequency from being formed at many locations on the heat dissipation fins 11 to 16, thereby further improving the electromagnetic shielding performance against noise.

[0047] [Seventh embodiment] A seventh embodiment of the present disclosure will be described below with reference to the drawings. In the seventh embodiment, differences from the second embodiment will be described. The same reference numerals will be used to designate common components.

[0048] The ECU 1 of the seventh embodiment differs from the second embodiment in that the shapes of the heat dissipation fins 11 to 16 are changed. As shown in FIG. 12, if the heights of the lowest points of the heat dissipation fins 11 to 16 are designated as minimum heights BH1, BH2, BH3, BH4, BH5, and BH6, the heat dissipation fins 11 to 16 are formed so that the minimum heights BH1 to BH6 are different from one another.

[0049] The ECU 1 configured in this manner can further prevent antennas that resonate at one specific frequency from being formed at many locations on the heat dissipation fins 11 to 16, thereby further improving the electromagnetic shielding performance against noise.

[0050] [Eighth embodiment] An eighth embodiment of the present disclosure will be described below with reference to the drawings. In the eighth embodiment, differences from the third embodiment will be described. The same reference numerals will be used to designate common components.

[0051] The ECU 1 of the eighth embodiment differs from the third embodiment in that the shapes of the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, and 16b are changed.

[0052] Here, the heights of the highest points of the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, and 16b are defined as maximum heights TH11, TH12, TH13, TH14, TH15, TH16, TH17, TH18, TH19, TH20, and TH21.

[0053] As shown in FIG. 13, the heat dissipation fins 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, and 16b are formed so that their maximum heights TH11, TH12, TH13, TH14, TH15, TH16, TH17, TH18, TH19, TH20, and TH21 are different from one another.

[0054] The ECU 1 configured in this manner can further prevent antennas that resonate at one specific frequency from being formed at many locations on the heat dissipation fins 11 to 16, thereby further improving the electromagnetic shielding performance against noise.

[0055] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment and can be implemented in various modifications. In the above embodiments, multiple functions of one component may be realized by multiple components, or one function of one component may be realized by multiple components. Furthermore, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. [Explanation of symbols]

[0056] 1...ECU, 2...ECU case, 11, 12, 13, 14, 15, 16...heat dissipation fins

Claims

1. a housing (2) that houses a wiring board on which electronic components are mounted; a plurality of heat dissipation fins (11 to 16) installed on the outer surface of the housing so as to extend along a preset extension direction (D1); Each of the plurality of heat dissipation fins is formed so that its height from the outer surface varies along the extension direction, The plurality of heat dissipation fins are formed so that the height gradually increases from the first end toward the inside along the extension direction, and the height gradually increases from the second end toward the inside along the extension direction, thereby forming an electronic control device (1) in which the height gradually changes throughout the entire extension direction.

2. A housing (2) that houses a wiring board on which electronic components are mounted, a plurality of heat dissipation fins (11 to 16) installed on the outer surface of the housing so as to extend along a preset extension direction (D1); Each of the plurality of heat dissipation fins is formed so that its height from the outer surface varies along the extension direction, The plurality of heat dissipation fins are formed so that their height gradually decreases as they move inward from the first end along the extension direction, and so that their height gradually decreases as they move inward from the second end along the extension direction, thereby causing the height to gradually change throughout the entire extension direction.

3. A housing (2) that houses a wiring board on which electronic components are mounted, a plurality of heat dissipation fins (11 to 16) installed on the outer surface of the housing so as to extend along a preset extension direction (D1); Each of the plurality of heat dissipation fins is formed so that its height from the outer surface varies along the extension direction, The electronic control device wherein all of the plurality of heat dissipation fins are formed so that the lengths along the extension direction are all different from one another.

4. An electronic control device as claimed in claim 1, The height at the highest point of each of the plurality of heat dissipation fins is defined as a maximum height, The plurality of heat dissipation fins are formed so that the maximum heights are different from each other.

5. An electronic control device according to claim 2, the height at the lowest point of each of the plurality of heat dissipation fins is defined as a minimum height; The plurality of heat dissipation fins are formed so that the minimum heights are different from one another.

6. The electronic control device according to any one of claims 1 to 5, At least some of the plurality of heat dissipation fins are arranged along the extension direction.

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