Electronic device

Abstract

The present application provides an electronic device capable of maintaining cooling performance. An electronic control device is provided with: a housing (10) having a housing base (11) opposed to a heat generating component; a cover (20) disposed so as to cover the housing base (11) and form an air flow path (12c) between the housing base (11); and a fan device mounted to the cover (20) and used to flow air in the air flow path (12c). In addition, the electronic control device is provided with: a main air inlet formed by the housing (10) and the cover (20) and connected to the air flow path (12c); and a restriction portion (50) formed by the housing (10) and the cover (20) and used to restrict the inflow of air into the air flow path (12c). The restriction portion (50) is formed with a sub air inlet (40) connected to the air flow path (12c).

Description

Technical Field

[0001] This disclosure relates to electronic devices. Background Technology

[0002] As an example of an electronic device, there is the electronic control device disclosed in Patent Document 1. The electronic control device includes: a housing comprising an upper housing and a lower housing; a heat sink cover that covers the upper side of a heat sink provided on the upper housing; and an air-cooling fan mounted on the upper housing for cooling. The housing adopts a forced air-cooling structure with an air-cooling fan.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2022-188388 Summary of the Invention

[0004] However, consider a structure in electronic devices that includes a fan and an air inlet. In this case, if the air inlet is blocked by foreign objects, the electronic device cannot draw in refrigerant. Therefore, the cooling performance of the electronic device may be reduced. Based on this point, or other points not mentioned, further improvements are required for the electronic device.

[0005] One object of the present invention is to provide an electronic device capable of maintaining cooling performance.

[0006] The electronic device disclosed herein includes: a housing housing a heat-generating component and having a cooling wall opposite to the heat-generating component; a cover portion disposed to cover the cooling wall and forming a refrigerant flow path between the cover portion and the cooling wall; a fan assembly mounted on the cover portion for causing the refrigerant to flow in the flow path; a first air inlet formed by the housing and the cover portion and connected to the flow path; and a restricting portion formed by at least one of the housing and the cover portion for restricting the inflow of refrigerant into the flow path, the restricting portion having a second air inlet connected to the flow path.

[0007] According to the electronic device disclosed herein, even if the first air inlet is blocked by foreign objects, refrigerant can still be drawn into the flow path through the second air inlet. Therefore, the electronic device is able to maintain cooling performance. Attached Figure Description

[0008] Figure 1 It is a three-dimensional diagram showing the general structure of the electronic control device.

[0009] Figure 2 It is an exploded three-dimensional diagram showing the general structure of the electronic control device.

[0010] Figure 3 This is a three-dimensional view taken from the back side of the cover.

[0011] Figure 4It is a plan view showing the general structure of the shell.

[0012] Figure 5 It is along Figure 1 A cross-sectional view of the VV line.

[0013] Figure 6 yes Figure 5 An enlarged sectional view of the VI-VI region.

[0014] Figure 7 This is a cross-sectional view showing the general structure of the limiting part in variation example 1.

[0015] Figure 8 This is a cross-sectional view showing the general structure of the limiting part in variation example 2.

[0016] Figure 9 This is a plan view showing the general structure of the shell in variation example 3.

[0017] Figure 10 This is a perspective view showing the general structure of the electronic control device in variation example 4. Detailed Implementation

[0018] Hereinafter, various embodiments for implementing this disclosure will be described with reference to the accompanying drawings. In each embodiment, the same reference numerals are sometimes used to mark parts corresponding to matters described in prior embodiments, and repeated descriptions are omitted. In each embodiment, where only a part of the structure is described, reference can be made to other previously described embodiments regarding the other parts of the structure. Furthermore, hereafter, three mutually orthogonal directions will be referred to as the X direction, Y direction, and Z direction.

[0019] (Implementation Method) use Figures 1-6 The electronic control device 100 of this embodiment will be described. In this embodiment, the electronic control device 100 is used as an example of an electronic device. The electronic control device 100 is configured to be mounted on a mobile body, for example. Examples of mobile bodies include electric vehicles, hybrid vehicles, fuel cell vehicles, electric vertical take-off and landing aircraft, drones, ships, construction machinery, and agricultural machinery. In this embodiment, a vehicle is used as an example of a mobile body. The electronic control device 100 is fixed to a mounting part that is part of the vehicle. Furthermore, electronic devices other than the electronic control device 100 can also be used.

[0020] The electronic control device 100 includes a housing 10, a cover 20, a fan device 30, and a circuit board 60. The electronic control device 100 is configured to cool the circuit board 60 using a refrigerant such as air. The air used as the refrigerant is cooling air.

[0021] The electronic control unit 100 receives output signals from sensors and other electronic devices mounted on the vehicle. Additionally, the electronic control unit 100 outputs control signals to onboard equipment mounted on the vehicle. The electronic control unit 100 is also known as an ECU. ECU is short for Electronic Control Unit.

[0022] The housing 10 houses the circuit board 60. The housing 10 includes, for example, a base member and a cover member. The base member is a concave member that can be used to mount the circuit board 60. The base member has an opening in an opposing region in the Z direction that faces the circuit board 60.

[0023] The cover component is assembled to the base component in a manner that blocks the opening. The housing 10 forms a receiving space for the circuit board 60 by assembling the cover component to the base component. The housing 10 is primarily composed of metals such as aluminum. However, the housing 10 may also be primarily composed of resin. In addition, the housing 10 may have a structure different from the above.

[0024] like Figure 1 , Figure 2 , Figure 4 As shown, the housing 10 includes a housing base 11, a plurality of heat sinks 12a disposed on the housing base 11, and a sidewall portion 15 disposed on the housing base 11. The housing base 11 is disposed opposite to one side of the circuit board 60. The housing base 11 is considered as part of the cover member.

[0025] like Figure 2 As shown, multiple heat sinks 12a and sidewall portions 15 are provided protruding relative to the outer surface in the Z direction. The outer surface of the housing base 11 is the surface of the portion of the housing base 11 facing the circuit board 60, and is a surface along the XY plane. The outer surface is the opposite surface to the inner surface of the housing base 11 on the receiving space side. The outer surface is the surface that contacts the flow paths 12c and 12d described later. The XY plane is an imaginary plane defined by the X-axis along the X direction and the Y-axis along the Y direction. The housing base 11 corresponds to a cooling wall.

[0026] Heat sinks 12a are provided protruding from the outer surface of the housing base 11 in the Z direction. Each heat sink 12a is provided along the Y direction. Multiple heat sinks 12a are arranged in the X direction.

[0027] The heat sink 12a is provided to increase the heat dissipation area. That is, by providing the heat sink 12a, the housing 10 can efficiently transfer heat from the heat-generating components described later to the air. Here, the air is the air flowing in the flow paths 12c and 12d.

[0028] like Figure 2 , Figure 4As shown, the sidewall portion 15 is provided in a manner that partially surrounds multiple heat sinks 12a. The sidewall portion 15 is interrupted on one side in the Y direction around all the heat sinks 12a. The sidewall portion 15 is interrupted to form the main air intake 12b. The main air intake 12b corresponds to the first air intake.

[0029] The sidewall portion 15 includes portions disposed at both ends of all the heat sinks 12a in the X direction. Furthermore, the sidewall portion 15 includes a portion disposed opposite to all the heat sinks 12a on the other side in the Y direction. The two portions are connected together. Alternatively, the sidewall portion 15 may also be described as including two portions disposed along the Y direction and a portion connecting one end of each portion. All the heat sinks 12a are disposed between the two portions.

[0030] like Figure 6 As shown, the sidewall portion 15 is covered by the cover 20. The sidewall portion 15 is arranged opposite to the sidewall portion 25 of the cover 20 in the Z direction. Furthermore, the sidewall ends 16 and 26 are arranged opposite to each other in the Z direction. The electronic control device 100 forms a secondary air intake 40 by the sidewall portions 15 and 25 and the sidewall ends 16 and 26. The sidewall portions 15 and 25 and the sidewall ends 16 and 26 constitute a restricting portion 50. The cover 20, the secondary air intake 40, and the restricting portion 50 will be described in detail later. That is, the sidewall portions 15 and 25 and the sidewall ends 16 and 26 will be described in detail later. The secondary air intake 40 corresponds to a second air intake.

[0031] like Figure 2 , Figure 4 As shown, a first flow path 12c is formed between adjacent heat sinks 12a. Additionally, the first flow path 12c is also formed between the heat sink 12a and the sidewall portion 15. The first flow path 12c is arranged along the Y direction.

[0032] In the Y direction, a second flow path 12d is formed between the heat sink 12a and the side wall portion 15. The second flow path 12d is the area opposite to the fan assembly 30 and the vent 22 described later. The first flow path 12c and the second flow path 12d correspond to the flow paths of the refrigerant. The first flow path 12c and the second flow path 12d are also referred to as flow paths 12c and 12d.

[0033] The first flow path 12c is connected to the main air intake 12b and the second flow path 12d. Therefore, the electronic control device 100 forms a space from the main air intake 12b through the first flow path 12c to the second flow path 12d. This space is the area for airflow for cooling. Flow paths 12c and 12d are areas sandwiched between the housing base 11 and the cover 20 in the Z direction. Flow paths 12c and 12d are the area between the housing base 11 and the cover 20. Furthermore, it can be said that the first flow path 12c communicates with the main air intake 12b and the second flow path 12d.

[0034] In addition, the housing base 11 is provided with a connector portion 13, a fixing portion 14, a positioning portion 17, and a fixing portion 18. The connector portion 13 is a through hole that penetrates the housing base 11 in the Z direction. The connector portion 13 is arranged opposite to the connector portion 23 of the cover 20. The connector portion 13 is provided with a portion of a cable that electrically connects the fan motor to the circuit board 60. That is, the connector portion 13 is provided for routing the cable from the circuit board 60 disposed in the housing space to the fan assembly 30.

[0035] The fixing part 14 is arranged opposite to the fixing part 24 of the cover 20. The fixing part 14 and the fixing part 24 are for fixing the cover 20 to the housing base 11. The cover 20 is fixed to the housing base 11, for example, by a threaded member. The fixing part 14 is provided with an internal thread. The fixing part 24 is a through hole for inserting the threaded member. However, the cover 20 can also be fixed to the housing base 11 by fitting or the like.

[0036] The positioning portion 17 is positioned opposite the positioning portion 27 of the cover 20. The positioning portion 17 is a protrusion protruding relative to its own periphery. The positioning portion 27 is a recessed portion relative to its own periphery. The cover 20 is positioned at an appropriate position on the housing base 11 by inserting the positioning portion 17 into the positioning portion 27. That is, the cover 20 and the housing base 11 are positioned by the positioning portions 17 and 27. Alternatively, in this disclosure, the positioning portion 17 may be a recessed portion and the positioning portion 27 may be a protrusion.

[0037] The fixing part 18 is a portion used to fix the electronic control device 100 to the mounting part. The electronic control device 100 is fixed, for example, by a threaded member. The fixing part 18 is a hole for inserting the threaded member. The mounting part is provided with internal threads. Alternatively, the electronic control device 100 can also be fixed to the mounting part by fitting or the like.

[0038] The cover 20 is configured to cover the base 11 of the housing. The cover 20 can also be described as a component that forms flow paths 12c and 12d between itself and the base 11 of the housing. Alternatively, the main air intake 12b can be described as being formed by the housing 10 and the cover 20. The cover 20 is equivalent to a covering portion.

[0039] like Figure 2 , Figure 3 As shown, the cover 20 includes a cover base 21 and a side wall portion 25 connected to the cover base 21. In addition, the cover 20 is provided with a connector portion 23, a fixing portion 24, and a positioning portion 27 as described above.

[0040] The base 21 is arranged opposite to a plurality of heat sinks 12a. A vent 22 is provided on the base 21 at a position opposite to the second flow path 12d. The vent 22 is a through hole provided in the base 21.

[0041] Sidewall portion 25 is arranged opposite to sidewall portion 15 as described above. Like sidewall portion 15, sidewall portion 25 is interrupted on one side in the Y direction at the annular edge of the cover base portion 21. Alternatively, sidewall portion 25 and sidewall portion 15 can be described as having a U-shape when viewed from above. The sidewall end portion 26 of sidewall portion 25 has a wall portion 26a, a wall portion 26b, and a bottom portion 26c.

[0042] The fan assembly 30 is a device for circulating air in flow paths 12c and 12d. The fan assembly 30 includes a fan motor, a fan mounted on the rotating shaft of the fan motor, and a fan cover 31 surrounding the fan. The fan motor is electrically connected to the circuit board 60 via a cable.

[0043] The cable has connectors at both ends. One connector connects to the fan motor. The other connector connects to the circuit board 60. The cable connects the fan motor to the circuit board 60 inside the housing 10 via connectors 13 and 23.

[0044] The fan motor is driven and controlled by a control signal from the circuit board 60. That is, the fan motor's rotating shaft rotates and stops according to the control signal. The fan assembly 30 is configured to rotate the fan by rotating the rotating shaft. Furthermore, the fan assembly 30 is configured to stop rotating the fan by stopping the rotating shaft. For convenience, the rotation of the rotating shaft and the stopping of the rotating shaft will be referred to below as the rotation of the fan assembly 30 and the stopping of the fan assembly.

[0045] like Figure 1 , Figure 2 As shown, the fan cover 31 is mounted on the cover 20. More specifically, the fan cover 31 is mounted on a portion of the cover base 21. Furthermore, the fan cover 31 is mounted opposite the vent 22 provided on the cover base 21. The fan cover 31 is mounted to the cover base 21 by fitting or the like.

[0046] The fan shroud 31 is provided with an exhaust port 32 for discharging air. The exhaust port 32 can also be regarded as the space (opening) between the fan shroud 31 and the shroud base 21. In addition, the electronic control device 100 forms the exhaust port 32 between the fan shroud 31 and the shroud base 21 by mounting the fan shroud 31 to the shroud base 21.

[0047] The fan assembly 30 draws in air from the external environment of the electronic control device 100 through the main air intake 12b by rotating the fan. Furthermore, the fan assembly 30 discharges the air drawn in from the main air intake 12b to the external environment through flow paths 12c and 12d and vent 22 to the exhaust port 32. Thus, the fan assembly 30 creates an airflow from the main air intake 12b through flow paths 12c and 12d and vent 22 to the exhaust port 32. This allows the fan assembly 30 to cool the heat-generating components.

[0048] The circuit board 60 includes a wiring board and circuit elements, connectors, etc., mounted on the wiring board. The wiring board has one side along the XY plane, one side opposite to the same side, and a side connected to the opposite side. One side is the side opposite to the housing base 11, or the opposing side. The circuit elements and connectors are mounted on one side or the opposite side of the wiring board.

[0049] Circuit components include microcomputers and passive components (capacitors, resistors). Microcomputers possess processing units such as CPUs, storage devices such as SRAM and flash memory, and communication interfaces. CPU is an abbreviation for Central Processing Unit. SRAM is an abbreviation for Static Random Access Memory.

[0050] The circuit board 60 is electrically connected to sensors and other electronic devices via connectors. Therefore, the circuit board 60 receives output signals from sensors and other electronic devices. Additionally, the circuit board 60 is electrically connected to an external power supply via connectors. Power is supplied to the circuit board 60 from the external power supply.

[0051] The circuit board 60, for example, executes a program stored in a storage device using an arithmetic processing unit. The arithmetic processing unit performs calculations by executing the program. The arithmetic processing unit uses output signals input to the communication interface, data stored in the storage device, etc., for calculations. The arithmetic processing unit calculates control signals through these calculations. The arithmetic processing unit outputs control signals to the vehicle-mounted equipment via the communication interface.

[0052] Furthermore, the processing unit calculates the control signal for driving and controlling the fan motor. The processing unit outputs the control signal to the fan motor via a communication interface. In this way, the circuit board 60 has the function of driving and controlling the fan device 30.

[0053] Microcomputers generate heat during operation. Therefore, microcomputers are also referred to as heat-generating components. The circuit board 60 may also contain heat-generating components other than microcomputers. Heat-generating components other than microcomputers include semiconductor switching elements, IC chips, etc.

[0054] From a heat dissipation perspective, the heat-generating component is preferably mounted on one side. That is, the heat-generating component is mounted on one side and thus arranged opposite to the heat sink 12a, flow paths 12c, and 12d. Therefore, the heat-generating component is cooled efficiently by air. Furthermore, the circuit board 60 itself can also be considered as a heat-generating component.

[0055] Here, use Figure 5 , Figure 6 The secondary air intake 40 and the limiting section 50 will be explained. Furthermore, Figure 6This is a sectional view along the XZ plane. The XZ plane is an imaginary plane defined by the X-axis and the Z-axis along the Z direction. The sidewall ends 16, 26 have the same shape, for example, from one end of sidewall portions 15, 25 to the other end. Figure 6 The simplified illustration shows the end portions 16 and 26 of the sidewall.

[0056] like Figure 6 As shown, the sidewall end portion 26 is a portion located at the end of the sidewall portion 25. The sidewall end portion 26 has a wall portion 26a, a wall portion 26b, and a bottom portion 26c. The wall portions 26a and 26b are portions that protrude relative to the bottom portion 26c. The sidewall end portion 26 has a concave cross-sectional shape. It can be said that the sidewall end portion 26 has a groove formed by the wall portions 26a, 26b, and bottom portion 26c.

[0057] The sidewall end 16 is a portion located at the end of the sidewall portion 15. The sidewall end 16 is a portion that protrudes beyond the periphery of the sidewall end 16. The width of the sidewall end 16 is narrower than the portion of the sidewall portion 15 other than the sidewall end 16. The width of the sidewall end 16 is thinner than the gap between the wall portion 26a and the wall portion 26b.

[0058] The limiting part 50 has a sidewall end portion 16 disposed between the wall portion 26a and the wall portion 26b. That is, the sidewall end portion 16 is disposed opposite to the bottom 26c in the Z direction. Alternatively, it can be said that the sidewall end portion 16 is disposed in a groove in the sidewall end portion 26. The sidewall end portion 16 is disposed at a distance from the bottom 26c in the Z direction. The distance between the sidewall end portion 16 and the bottom 26c in the Z direction can also be referred to as a first space.

[0059] Furthermore, the sidewall end portion 16 is disposed opposite to the wall portion 26a and the wall portion 26b in the direction along the XY plane (hereinafter referred to as the XY direction). The sidewall end portion 16 is disposed spaced apart from the wall portion 26a and the wall portion 26b in the XY direction. The spacing between the sidewall end portion 16 and the wall portion 26a in the XY direction, and the spacing between the sidewall end portion 16 and the wall portion 26b in the XY direction, can also be referred to as a second space. The second space is connected to the first space.

[0060] Wall portions 26a and 26b are arranged opposite to side wall portion 15 in the Z direction. That is, wall portions 26a and 26b are arranged opposite to the peripheral portion of the side wall end portion 16 in side wall portion 15 in the Z direction. Wall portions 26a and 26b are arranged spaced apart from side wall portion 15 in the Z direction. The spacing between wall portion 26a and side wall portion 15 in the Z direction, and the spacing between wall portion 26b and side wall portion 15 in the Z direction, can also be referred to as a third space. The third space is connected to the second space.

[0061] The limiting section 50 forms a secondary air inlet 40 through the side wall end 16 and the side wall end 26. The secondary air inlet 40 is the gap between the side wall end 16 and the side wall end 26. That is, the secondary air inlet 40 is composed of a first space, a second space, and a third space. The secondary air inlet 40 is connected to the flow paths 12c and 12d. The secondary air inlet 40 is provided to draw air from the external environment into the flow paths 12c and 12d when the main air inlet 12b is blocked by foreign objects.

[0062] In this embodiment, as an example, a four-section crankshaft with a secondary air intake 40 is used. Figure 6 Alternatively, the secondary air intake 40 can be described as having a labyrinthine sealed shape. Therefore, the electronic control device 100 cannot easily draw air in through the secondary air intake 40 unless the main air intake 12b is blocked by foreign objects. Consequently, the electronic control device 100 can draw air in through the main air intake 12b, thus suppressing the reduction in the cooling effect of the heat-generating components.

[0063] However, the limiting part 50 can also be configured as a three-section crankshaft for the secondary air intake 40. Similarly, as with the case where the secondary air intake 40 is a four-section crankshaft, it can also be said that the secondary air intake 40 has a labyrinthine sealing shape. In this case, the sidewall portion 15 does not have a portion opposite to the wall portion 26b in the Z direction. That is, the limiting part 50 can also be composed of a sidewall portion 25 having the aforementioned sidewall end portion 26 and a sidewall portion 15 having the sidewall end portion 16 of the modified example 1 described later.

[0064] Furthermore, the state where the main air intake 12b is not blocked by foreign objects will be referred to as the normal state. Conversely, the state where the main air intake 12b is blocked by foreign objects will be referred to as the abnormal state.

[0065] Like the main air intake 12b, the secondary air intake 40 is an opening for drawing air into the flow paths 12c and 12d. However, the secondary air intake 40 is smaller than the main air intake 12b. The secondary air intake 40 determines the extent to which air is drawn primarily from the main air intake 12b under normal conditions by the rotation of the fan assembly 30.

[0066] Furthermore, it can be said that the opening area of ​​the secondary air intake 40 is narrower than that of the main air intake 12b. The opening area of ​​the main air intake 12b is the area of ​​the opening along the XZ plane. The secondary air intake 40 is, for example, the area between the side wall portion 15 and the wall portion 26b. The secondary air intake 40 can also be said to have an opening area that does not obstruct the intake of air from the main air intake 12b.

[0067] Therefore, under normal conditions, the electronic control unit 100 can more easily draw in refrigerant from the main air intake 12b compared to the auxiliary air intake 40. Consequently, the electronic control unit 100 can suppress the reduction in the cooling effect of heat-generating components.

[0068] The limiting section 50 restricts the flow of air from the external environment into the flow paths 12c and 12d. The limiting section 50 does not completely block the flow of air into the flow paths 12c and 12d. The limiting section 50 restricts the intake air from the secondary intake port 40 to a level where air is primarily drawn in from the main intake port 12b by the rotation of the fan device 30. That is, the limiting section 50 can also be described as a section that restricts the flow of air from the outside into the flow path 12c. Therefore, the limiting section 50 can also be called a regulating section.

[0069] In normal operation, the electronic control unit 100 draws air in from the main air intake 12b by rotating the fan unit 30. Therefore, as... Figure 4 As shown, the electronic control unit 100 draws in air in the first direction WD1. Furthermore, the air drawn in from the main air intake 12b flows through flow paths 12c and 12d and is discharged from the exhaust port 32. The electronic control unit 100 can cool the heat-generating components using the air drawn in from the main air intake 12b.

[0070] Furthermore, the electronic control unit 100 can primarily draw air from the main air intake 12b under normal conditions. Therefore, the electronic control unit 100 can also draw air from the auxiliary air intake 40 under normal conditions. However, under normal conditions, the amount of air from the auxiliary air intake 40 is sufficiently small compared to the amount of air from the main air intake 12b.

[0071] On the other hand, in abnormal conditions, the electronic control unit 100 draws air in from the auxiliary air intake 40 by rotating the fan unit 30. Therefore, as... Figure 4 As shown, the electronic control unit 100 draws in air in the second direction WD2. Furthermore, the air drawn in from the secondary air intake 40 flows through flow paths 12c and 12d and is discharged from the exhaust port 32. The electronic control unit 100 can cool the heat-generating components using the air drawn in from the secondary air intake 40.

[0072] In this embodiment, as an example, a limiting portion 50 formed by the housing 10 and the cover 20 is used. However, the limiting portion 50 may be formed by at least one of the housing 10 and the cover 20.

[0073] <Effect> As described above, the electronic control device 100 can still draw in air from the secondary air intake 40 into the flow paths 12c and 12d even if the main air intake 12b is blocked by foreign objects. Therefore, the electronic control device 100 can cool the heat-generating components. In this way, the electronic control device 100 can maintain its cooling performance.

[0074] The preferred embodiments of this disclosure have been described above. However, this disclosure is not limited to any of the above embodiments, and various modifications can be made without departing from the spirit of this disclosure. Hereinafter, modifications 1 to 4 will be described as other aspects of this disclosure. The above embodiments and modifications 1 to 4 can be implemented individually, or they can be implemented in appropriate combinations. This disclosure is not limited to the combinations shown in the embodiments, and can be implemented through various combinations.

[0075] <Variation Example 1> like Figure 7 As shown in Modification 1, the electronic control device 100 may also include a secondary air intake 40 configured as a limiting part 50 of a two-section crankshaft. Alternatively, the secondary air intake 40 may be described as having a labyrinthine sealed shape. Figure 7 It is equivalent to Figure 6 A sectional view.

[0076] The sidewall end 26 has a wall portion 26a and a bottom portion 26c. The sidewall end 26 in Modified Example 1 differs from the above embodiment in that it does not have a wall portion 26b. The wall portion 26a is a portion that protrudes relative to the bottom portion 26c. The sidewall end 16 is a portion that protrudes beyond its periphery. The width of the sidewall end 16 is set to be narrower than the portion of the sidewall portion 15 other than the sidewall end 16.

[0077] The sidewall end 16 is similarly disposed opposite to the bottom 26c in the Z direction as in the above embodiment. In the Z direction, a first space is formed between the sidewall end 16 and the bottom 26c.

[0078] Furthermore, the sidewall end 16 is arranged opposite to the wall portion 26a in the XY direction, similar to the embodiment described above. A second space is formed between the sidewall end 16 and the wall portion 26a in the XY direction.

[0079] The wall portion 26a is arranged opposite the side wall portion 15 in the Z direction, similar to the embodiment described above. A third space is formed between the wall portion 26a and the side wall portion 15 in the Z direction.

[0080] The secondary air intake 40 is composed of a first space, a second space, and a third space. The electronic control device 100 of Modified Example 1 can achieve the same effect as the above embodiment.

[0081] <Variation Example 2> like Figure 8 As shown in Modification 2, the electronic control device 100 may also include a secondary air intake 40 configured as a limiting part 50 of a single-section crankshaft. Alternatively, the secondary air intake 40 may be described as having a labyrinthine sealed shape. Figure 8 It is equivalent to Figure 6 A sectional view.

[0082] The sidewall end 26 has a wall portion 26a. The sidewall end 26 of Modified Example 2 differs from the above embodiment in that it does not have a wall portion 26b or a bottom portion 26c. The sidewall portion 15 (sidewall end 16) is the same as in Modified Example 1.

[0083] The sidewall end portion 16 is not opposite to the sidewall portion 25 in the Z direction. Furthermore, similarly to the embodiment described above, the sidewall end portion 16 is positioned opposite the wall portion 26a in the XY direction. Therefore, a second space is formed between the sidewall end portion 16 and the wall portion 26a in the XY direction.

[0084] The wall portion 26a is arranged opposite the side wall portion 15 in the Z direction, similar to the embodiment described above. Therefore, a third space is formed between the wall portion 26a and the side wall portion 15 in the Z direction.

[0085] The secondary air intake 40 is composed of a second space and a third space. The electronic control device 100 of Modified Example 2 can achieve the same effect as the above embodiment.

[0086] <Variation Example 3> like Figure 9 As shown in Modification 3, the electronic control device 100 may also include heat sinks 12a with slits 12a1. Each heat sink 12a is cut off by the slits 12a1 in the Y direction.

[0087] As described above, the electronic control device 100 draws in air in the second direction WD2 under abnormal conditions. Because the electronic control device 100 has slits 12a1 in each heat sink 12a, air can easily flow in the X direction. Therefore, air can easily flow within the flow paths 12c and 12d under abnormal conditions. Thus, the electronic control device 100 can efficiently cool the heat-generating components even under abnormal conditions. The electronic control device 100 of Modified Example 3 achieves the same effect as the embodiment described above.

[0088] <Variation Example 4> like Figure 10 As shown in Modification 4, the electronic control device 101 can also include a cover 20 with an opening 251. That is, the secondary air inlet 40 can also include an opening 251 provided in the cover 20. The opening 251 is provided in the side wall portion 25. For example, the opening 251 is provided in multiple locations in the side wall portion 25. In addition, the electronic control device 101 connects the flow paths 12c and 12d to the external environment through the opening 251. The electronic control device 101 of Modification 4 can achieve the same effect as the embodiment described above.

[0089] Furthermore, the electronic control device 101 in Modification 4 may not form a first space, a second space, or a third space. That is, the electronic control device 101 in Modification 4 has an opening 251 as a secondary air inlet 40. In this case, the restrictive part 50 can be said to be formed by the cover 20.

[0090] The preferred embodiments of this disclosure have been described above. This disclosure is not limited to these embodiments or structures. This disclosure includes various modifications and variations within the same range. Furthermore, various combinations or forms are shown in this disclosure, but other combinations or forms containing only one element, more than one element, or less than one element also fall within the scope or concept of this disclosure.

Claims

1. An electronic device, characterized in that, have: A housing that houses a heating element and has a cooling wall opposite the heating element; A cover portion is configured to cover the cooling wall, and a refrigerant flow path is formed between the cover portion and the cooling wall; A fan assembly, installed on the cover, is used to allow the refrigerant to flow in the flow path; The first air inlet is formed by the housing and the cover, and is connected to the flow path; as well as A limiting portion, formed by at least one of the housing and the cover portion, restricts the inflow of the refrigerant into the flow path. The limiting part has a second air inlet connected to the flow path.

2. The electronic device according to claim 1, characterized in that, The second air inlet is smaller than the first air inlet.

3. The electronic device according to claim 1 or 2, characterized in that, The second air intake has a labyrinth-like sealed shape.

4. The electronic device according to claim 1 or 2, characterized in that, The second air inlet includes an opening provided in the cover.

5. The electronic device according to claim 1 or 2, characterized in that, The housing has heat dissipation fins protruding relative to the cooling wall. The heat sink has slits.

6. The electronic device according to claim 3, characterized in that, The flow path has one or more bends.

7. The electronic device according to claim 1 or 2, characterized in that, The fan assembly and the cover form an exhaust port connected to the flow path.

8. The electronic device according to claim 1 or 2, characterized in that, The first air intake faces the first direction. The second air inlet faces a second direction that intersects with the first direction.

9. The electronic device according to claim 8, characterized in that, The housing has heat sinks extending along the first direction. The heat sink has a slit facing the second direction.

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