Electronic control device

Abstract

To provide an electronic control device which inhibits exposure of an electronic component from a liquid refrigerant to inhibit deterioration of cooling performance of the electronic component even when a movable body vibrates or inclines.SOLUTION: An electronic control device according to the present invention comprises: a circuit board 10 on which an electronic component 11 is mounted; a housing 2 which houses the circuit board 10 and a liquid refrigerant 20; a cooler 30 which is arranged at an upper side in the housing 2; and a wall part 40 which extends from a bottom part in the housing 2 toward the cooler 30 and divides the inside of the housing 2 into a first region 61 and a second region 62. The circuit board 10 is immersed in the liquid refrigerant 20 in the first region 61. In the housing 2, at least two flow channels 51 that provide communication between the first region 61 and the second region 62 are formed. The channels 51 are each provided with a valve 50 that allows flow of the liquid refrigerant 20 from the second region 62 to the first region 61 and restricts flow of the liquid refrigerant 20 from the first region 61 to the second region 62.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an electronic control device. [Background technology]

[0002] In electronic control devices used in vehicles, etc., the processing speed of arithmetic circuits such as central processing units (CPUs) mounted on circuit boards is increasing in order to improve the performance of the devices, and the amount of heat generated by these arithmetic circuits (electronic components) is also increasing. Well-known methods for cooling heat-generating electronic components include air cooling and water cooling. These cooling methods involve applying air or cooling water at a temperature lower than the heat generated by the electronic components to cooling fins or other devices connected to the electronic components. Another cooling method is immersion boiling cooling, in which heat-generating electronic components are directly immersed in a liquid refrigerant, and the heat is then vaporized by the liquid refrigerant, thereby removing the heat.

[0003] For example, Patent Document 1 discloses a technology for cooling a semiconductor device, which is a heat-generating body, from two directions using two cooling means. Patent Document 1 discloses a cooler that circulates cooling water in a coolant container and a liquid coolant that boils at a predetermined temperature, and cools one side of the semiconductor device by contacting the cooler, while immersing the other side in the liquid coolant to boil and cool it.

[0004] Patent Document 2 discloses an electrical device in which a heat-generating component is immersed in a liquid refrigerant, the liquid refrigerant stored inside a housing is vaporized by the heat generated by the heat-generating component, and the vaporized refrigerant is cooled by a heat exchange mechanism disposed above the housing. In Patent Document 2, a guide member extending in the vertical direction is provided between the side wall of the housing and the heat-generating component, and a passage through which the vaporized refrigerant can flow is formed above the guide member, and a flow path through which the liquid refrigerant can flow is formed below the guide member. With the above-described configuration in Patent Document 2, the guide member separates the boiling of the liquid refrigerant, the condensation of the vaporized refrigerant, and the reflux of the condensed liquid refrigerant, thereby regulating the flow of the refrigerant.

[0005] In electronic control devices mounted on moving objects such as vehicles, there is a problem with applying the immersion boiling cooling method described in Patent Documents 1 and 2. The problem is that the liquid level of the liquid refrigerant placed inside the device may fluctuate or tilt due to vibration or tilting of the moving object, which may expose the heat-generating electronic components from the liquid refrigerant and result in insufficient cooling performance.

[0006] To solve this problem, Patent Document 3 discloses a structure that includes a cooling tank in which a heating element is stored, a liquid storage tank, and a connecting part that connects these, and that has a liquid level control part that prevents the heating element from being exposed from the liquid refrigerant when the cooling tank is tilted. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2008-227150 [Patent Document 2] Patent Publication No. 2022-179901 [Patent Document 3] Patent Publication No. 2023-149859 Summary of the Invention [Problem to be solved by the invention]

[0008] In electronic control devices mounted on moving objects such as vehicles, the level of the liquid refrigerant placed inside the electronic control device fluctuates when the moving object vibrates or when the moving object travels over an incline such as a slope, causing the electronic components to be cooled to become exposed. One way to prevent this is to increase the amount of liquid refrigerant placed inside the electronic control device so that the electronic components are not exposed even when the liquid refrigerant level fluctuates, but this has the problem of increasing the weight of the electronic control device.

[0009] Furthermore, to improve cooling performance, it is necessary to efficiently circulate the liquid refrigerant that immerses the electronic components, the liquid refrigerant boils due to heat generated by the electronic components, the boiled refrigerant is condensed by the cooler, and the condensed refrigerant is returned to immerse the electronic components again.

[0010] Patent Documents 1 and 2 do not disclose a means for solving the problem of fluctuations in the liquid refrigerant level due to vibration or tilting of the moving body. Furthermore, Patent Document 3 discloses a means for solving the problem of fluctuations in the liquid refrigerant level, but does not disclose a means for efficiently circulating the liquid refrigerant through immersion, boiling, and condensation.

[0011] The object of the present invention is to provide an electronic control device that can prevent electronic components from being exposed to liquid refrigerant even when the moving body vibrates or tilts, and can prevent a decrease in the cooling performance of the electronic components. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention provides an electronic control device to be mounted on a moving body, comprising: a circuit board on which electronic components are mounted; a housing that houses the circuit board and a liquid refrigerant; a cooler arranged at an upper part within the housing; and a wall extending from the bottom of the housing toward the cooler and dividing the housing into a first area and a second area, wherein the circuit board is immersed in the liquid refrigerant within the first area, and at least two flow paths are formed within the housing that connect the first area and the second area, and the flow paths are equipped with valves that allow the liquid refrigerant to flow from the second area toward the first area and limit the flow of the liquid refrigerant from the first area toward the second area. [Effects of the Invention]

[0013] According to the present invention, an electronic control device can be provided that prevents electronic components from being exposed to the liquid refrigerant even when the moving body vibrates or tilts, thereby preventing a decrease in the cooling performance of the electronic components. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a front cross-sectional view of a conventional electronic control device 1. [Figure 2] FIG. 1 is a side cross-sectional view of a conventional electronic control device 1. [Figure 3] FIG. 10 is a front cross-sectional view of a conventional electronic control device 1 when the liquid level of a liquid refrigerant 20 is inclined. [Figure 4] FIG. 10 is a cross-sectional side view of a conventional electronic control device 1 when the liquid level of a liquid refrigerant 20 is inclined. [Figure 5] 1 is a front cross-sectional view of an electronic control device 1 according to a first embodiment of the present invention, as viewed from the normal direction of a circuit board 10. FIG. [Figure 6] 6 is a diagram illustrating a state in which the liquid surface of liquid refrigerant 20 is inclined relative to the bottom surface of housing 2 in electronic control device 1 shown in FIG. 5. FIG. [Figure 7] 1 is an enlarged bottom view of an electronic control device 1 according to a first embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing a state in which the liquid surface of the liquid refrigerant 20 is tilted for a long period of time. [Figure 9] 1 is a side cross-sectional view of an electronic control device 1 according to a first embodiment of the present invention, as viewed from a horizontal tangential direction of a circuit board 10. FIG. [Figure 10] FIG. 10 is an external perspective view of an electronic control device 1 according to a second embodiment of the present invention. [Figure 11] 10 is a front cross-sectional view of an electronic control device 1 according to a second embodiment of the present invention, as viewed from the normal direction of a circuit board 10. FIG. [Figure 12] FIG. 10 is an external perspective view of an electronic control device 1 according to a third embodiment of the present invention. [Figure 13] 13 is a cross-sectional view taken along the line XIII-XIII of FIG. 12 at plane 71. FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. [Figure 15] FIG. 15 is a cross-sectional view taken along line XV-XV in FIGS. 13 and 14. [Figure 16] FIG. 16 is a cross-sectional view according to Comparative Example 1 compared with the structure of FIG. [Figure 17] FIG. 16 is a cross-sectional view of Comparative Example 2 compared with the structure of FIG. [Figure 18] FIG. 10 is a cross-sectional view of a modified example of the third embodiment. [Figure 19] FIG. 10 is a cross-sectional view of a modified example of the third embodiment. [Figure 20]10 is a front cross-sectional view of an electronic control device 1 according to a fourth embodiment of the present invention, as viewed from the normal direction of a circuit board 10. FIG. [Figure 21] FIG. 10 is a cross-sectional view of a modified example of the fourth embodiment. [Figure 22] 10 is a front cross-sectional view of an electronic control device 1 according to a fifth embodiment of the present invention, as viewed from the normal direction of a circuit board 10. FIG. [Figure 23] FIG. 10 is an enlarged bottom view of an electronic control device 1 according to a fifth embodiment of the present invention. [Figure 24] 10 is a front cross-sectional view of an electronic control device 1 according to a sixth embodiment of the present invention, as viewed from the normal direction of a circuit board 10. FIG. [Figure 25] FIG. 20 is a cross-sectional view according to a first modified example of the sixth embodiment. [Figure 26] FIG. 20 is an external perspective view of the electronic control device 1 according to a second modified example of the sixth embodiment. [Figure 27] 27 is a cross-sectional view taken along the line XXVII-XXVII of FIG. 26 at plane 71. FIG. [Figure 28] FIG. 20 is an external perspective view of the electronic control device 1 according to a third modified example of the sixth embodiment. [Figure 29] 29 is a cross-sectional view taken along the line XXIX-XXIX of FIG. 28 at plane 71. FIG. [Figure 30] FIG. 10 is a partially enlarged cross-sectional view of a wall portion 40 of an electronic control device 1 according to a seventh embodiment of the present invention. [Figure 31] FIG. 13 is a cross-sectional view of a modified example of the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In principle, identical elements are assigned the same reference numerals in all drawings. Furthermore, descriptions of parts having the same functions will be omitted. The configurations described below are merely examples, and are not intended to limit the embodiments of the present invention to the specific embodiments described below. In each drawing, the upper side of the page is defined as "top" and the lower side as "bottom." Furthermore, in a front view of the electronic control device as seen from the normal direction of the circuit board 10, the left side is defined as "left," the right side as "right," the near side as "front," and the far side as "rear."

[0016] First, a conventional electronic control device will be described with reference to FIGS. 1 to 4. FIG. 1 is a front cross-sectional view of a conventional electronic control device 1. In FIG. 1, the electronic control device has an internal space defined by a housing 2 and a cover 3. The housing 2 includes a circuit board 10, a liquid refrigerant 20, and a cooler 30. Electronic components 11 are mounted on the surface of the circuit board 10. The heat-generating electronic components 11 are immersed in an insulating liquid refrigerant 20. The boiling point of the liquid refrigerant is lower than the heat generation temperature of the electronic components. Cooling water 31, which is cooled outside the electronic control device 1 and has a temperature lower than the boiling point of the liquid refrigerant, flows through the cooler 30. The liquid refrigerant 20 is heated and boils due to the heat generated by the electronic components 11. The boiling refrigerant 21 is cooled by the cooler 30 located above the inside of the housing 2. The cooled boiling refrigerant 21 is condensed into condensed refrigerant 22 and returns to the liquid refrigerant 20. By repeating this boiling and condensing, the heat generated by the electronic components 11 is transferred to the cooling water and discharged to the outside of the electronic control device 1.

[0017] Fig. 2 is a side cross-sectional view of a conventional electronic control device 1. As shown in Fig. 2, four circuit boards 10 are arranged inside a housing 2, and electronic components 11 are mounted on each circuit board 10. In Fig. 2, similar to Fig. 1, liquid refrigerant 20 is heated and boiled by electronic components 11, and boiling refrigerant 21 is cooled by a cooler 30 installed above inside the housing 2, and condensed refrigerant 22 returns to liquid refrigerant 20.

[0018] 1 and 2 are schematic diagrams showing the state in which the liquid level of liquid refrigerant 20 placed inside electronic control device 1 is horizontal. Figures 3 and 4 are cross-sectional views of electronic control device 1 in a state in which the liquid level of liquid refrigerant 20 is inclined.

[0019] 3 is a front cross-sectional view of conventional electronic control device 1 when the liquid level of liquid refrigerant 20 is tilted. As shown in Fig. 3, the liquid level of liquid refrigerant 20 is higher on the right side and lower on the left side relative to the bottom surface of housing 2. When the liquid level of liquid refrigerant 20 is tilted, part of electronic component 11 is exposed from liquid refrigerant 20, and the cooling performance of electronic component 11 at exposed portion 23 deteriorates.

[0020] 4 is a side cross-sectional view of conventional electronic control device 1 when the liquid level of liquid refrigerant 20 is tilted. As shown in Fig. 4, the liquid level of liquid refrigerant 20 is higher on the front side of housing 2 and lower on the rear side. When the liquid level of liquid refrigerant 20 is tilted, part of electronic component 11 is exposed from liquid refrigerant 20, and the cooling performance of electronic component 11 deteriorates at exposed portion 23.

[0021] One possible method for preventing exposure of electronic components 11 from liquid refrigerant 20 due to the tilt of the liquid surface of liquid refrigerant 20 shown in Figures 3 and 4 is to increase the amount of liquid refrigerant 20 placed inside electronic control device 1, but this has the problem of increasing the weight of electronic control device 1.

[0022] Hereinafter, an embodiment of an electronic control device according to the present invention will be described with reference to the drawings. In each drawing, common members are given the same reference numerals. [Example]

[0023] 5 is a front cross-sectional view of the electronic control device 1 according to the first embodiment of the present invention, as viewed from the normal direction of the circuit board 10. In FIG. 5, the liquid surface of the liquid refrigerant 20 is shown as being horizontal.

[0024] 5, the electronic control device has a housing 2 with an open top and a cover 3 covering the open top, creating an internal space. The housing 2 contains a circuit board 10, a liquid refrigerant 20, and a cooler 30.

[0025] The circuit board 10 is disposed with its plane oriented vertically, and is connected to other electronic control devices and the like via connectors and harnesses (not shown). Electronic components 11 are mounted on the surface of the circuit board 10. The heat-generating electronic components 11 are immersed in an insulating liquid coolant 20 having a boiling point lower than the heat generation temperature of the electronic components. The liquid coolant 20 is, for example, a fluorine-based inert liquid such as perfluoropolyether (PFPE), perfluorocarbon (PFC), or hydrofluoroether (HFE). Hydrofluoroether), as well as silicone oil, etc. are used.

[0026] The housing 2 is formed with walls 40 (40a, 40b) extending from the bottom surface (lower side) of the housing 2 toward the cooler 30 above. In FIG. 5, the wall 40 is formed with the wall 40a on the left side in the longitudinal direction of the circuit board 10 and the wall 40b on the right side, but the walls 40 are similarly formed on the front and rear sides in the longitudinal direction of the circuit board 10. The front and rear walls may be configured such that the ends of the left wall 40a and the right wall 40b are in contact with the inner walls of the housing 2. The left wall 40a and the right wall 40b are arranged to face each other, and the front wall and the rear wall are arranged to face each other.

[0027] The internal space of the housing 2 is divided by the wall 40 into a first area 61 (shown by a dashed line) in which the circuit board 10 is housed, and a second area 62 (shown by a dotted line) formed between the wall 40 and the wall surface of the housing 2.

[0028] The space formed between the liquid refrigerant 20 and the cover 3 inside the housing 2 is filled with gas resulting from boiling or vaporizing the liquid refrigerant 20 and the air remaining when the liquid refrigerant 20 is sealed in. The inside of the housing 2 may be placed in a low-pressure state such as a vacuum before the liquid refrigerant 20 is introduced.

[0029] A flow path 51a (first flow path) through which the liquid refrigerant 20 can flow between the first region 61 and the second region 62 is provided in the lower part of the wall portion 40a. Similarly, a flow path 51b (second flow path) through which the liquid refrigerant 20 can flow between the first region 61 and the second region 62 is provided in the lower part of the wall portion 40b.

[0030] Furthermore, the flow path 51a is provided with an openable / closable valve 50a (first valve) that allows the liquid refrigerant 20 to flow from the second region 62 toward the first region 61 and restricts the flow of the liquid refrigerant 20 from the first region 61 toward the second region 62. Similarly, the flow path 51b is provided with an openable / closable valve 50b (second valve) that allows the liquid refrigerant 20 to flow from the second region 62 toward the first region 61 and restricts the flow of the liquid refrigerant 20 from the first region 61 toward the second region 62. In FIG. 5, the valves 50a and 50b are schematically shown as valves that have a fulcrum at their upper ends and open in an arc shape upward around the fulcrum. In this embodiment, at least two flow paths 51a and 51b that communicate between the first region 61 and the second region 62 are formed in the housing 2, and valves 50a and 50b are installed in the flow paths 51a and 51b, respectively.

[0031] Cooling water 31 that has been cooled outside the electronic control device 1 to a temperature lower than the boiling point of the liquid refrigerant 20 circulates inside the cooler 30. The liquid refrigerant 20 is heated and boils due to heat generated by the electronic components 11, and the boiled refrigerant 21 is cooled by the cooler 30 disposed above the interior of the housing 2, and the cooled boiling refrigerant 21 is condensed to become condensed refrigerant 22, returning to the liquid refrigerant 20. The lower surface of the cooler 30 is inclined downward from the center position in the left-right direction toward the outside (periphery) in the left-right direction.

[0032] 5, the cooler 30 side of the wall portion 40a and the wall portion 40b are provided with inclined portions 41a and 41b that are inclined so that the opposing wall portions 40a and 40b approach each other as they move toward the cooler 30 side (upward). As a result, the condensed refrigerant 22a that is condensed in the cooler 30 and falls onto the inclined portions 41a and 41b flows toward the liquid refrigerant 20 that has accumulated in the second region 62 along the inclination of the inclined portions 41a and 41b.

[0033] When the liquid level of liquid refrigerant 20 accumulated in second region 62 becomes higher than the liquid level of liquid refrigerant 20 in first region 61, liquid refrigerant 20 moves from second region 62 toward first region 61 through flow paths 51a, 51b and valves 50a, 50b provided in walls 40a, 40b. This makes it possible for wall 40 to separate boiling refrigerant 21 generated in first region 61 from condensed refrigerant 22 condensed in cooler 30, thereby enabling efficient cooling of electronic components 11.

[0034] 5, the cooler 30 is inclined toward the side of the housing 2. This allows the condensed refrigerant 22b that is condensed in the cooler 30 and adheres to the surface of the cooler 30 to be guided toward the side of the housing 2.

[0035] With the above-described structure, the circulation of the liquid refrigerant 20 immersing the circuit board 10, the boiling refrigerant 21 boiled by the electronic components, and the condensed refrigerant 22 condensed in the cooler 30 can be separated by the walls 40a and 40b, thereby allowing the electronic components to be cooled efficiently.

[0036] Fig. 6 is a diagram showing a state in which the liquid level of liquid refrigerant 20 is inclined with respect to the bottom surface of housing 2 in electronic control device 1 shown in Fig. 5. Fig. 7 is an enlarged view of the bottom of electronic control device 1 according to Example 1 of the present invention.

[0037] FIG. 6 shows a state in which the liquid level of the liquid refrigerant 20 is high on the right side and low on the left side. The function of the valves 50a and 50b at this time will be explained using FIG. 7. The valve 50b installed on the right wall portion 40b is subjected to pressure from the liquid refrigerant 20 in the direction from the first region 61 to the second region 62, so the valve 50b closes the flow path 51b. Therefore, in the flow path 51b, the valve 50b prevents the flow 20b of the liquid refrigerant 20 from the first region 61 to the second region 62. On the other hand, the valve 50a installed on the left wall portion 40a is subjected to pressure from the liquid refrigerant 20 in the direction from the second region 62 to the first region 61, so the valve 50a opens the flow path 51a. As a result, the flow 20a of the liquid refrigerant 20 is allowed in the flow path 51a from the second region 62 to the first region 61.

[0038] As described above, in this embodiment, the function of valves 50a and 50b prevents the liquid refrigerant 20 from flowing out from the first region 61 to the second region 62 on the right side, while allowing the liquid refrigerant 20 to flow from the second region 62 on the left side into the first region 61. Therefore, even when the liquid level of the liquid refrigerant 20 tilts, the decrease in the liquid level of the liquid refrigerant 20 in the first region 61 can be suppressed, and exposure of the electronic components 11 to the liquid refrigerant 20 can be suppressed.

[0039] FIG. 8 shows a state in which the liquid level of the liquid refrigerant 20 remains tilted for a long period of time. When the liquid refrigerant 20 remains tilted for a long period of time, such as when a vehicle is parked on a slope, the condensed refrigerant 22 condensed in the cooler 30 accumulates unevenly in the second region 62 on the right side. As a result, the liquid level in the second region 62 on the right side rises, as shown by liquid level 20c in FIG. 8. When the liquid level in the second region 62 on the right side becomes higher than the liquid level in the first region 61, the force of the liquid refrigerant 20 acts on the valve 50b from the second region 62 toward the first region 61. As a result, the valve 50b opens the flow path 51b, allowing the liquid refrigerant 20 to flow toward the first region 61. Therefore, even if the liquid level remains tilted, the liquid level of the liquid refrigerant 20 in the first region 61 does not continue to decrease.

[0040] 5 to 8, the first embodiment has been described using a front cross-sectional view of the electronic control device 1 when viewed from the normal direction of the circuit board 10. In Fig. 9, the first embodiment will be described using a side cross-sectional view of the electronic control device 1 when viewed from the horizontal tangential direction of the circuit board 10. Fig. 9 is a side cross-sectional view of the electronic control device 1 according to the first embodiment of the present invention when viewed from the horizontal tangential direction of the circuit board 10.

[0041] As shown in FIG. 9, four (a plurality of) circuit boards 10 are arranged in the front-rear direction inside the housing 2, and electronic components 11 are mounted on each circuit board 10.

[0042] In the housing 2, wall portions 40 (40c, 40d) extending from the bottom surface (lower side) of the housing 2 toward the cooler 30 are formed on the front and rear sides of the four circuit boards 10. In FIG. 9, as the wall portions 40, wall portion 40c is formed on the front side of the circuit boards 10, and wall portion 40d is formed on the rear side of the circuit boards 10. The front wall portion 40c and the rear wall portion 40d are arranged to face each other.

[0043] The space inside the housing 2 is divided by the walls 40c and 40d into a first area 61 (shown by a dashed line) in which the circuit board 10 is housed, and a second area 62 (shown by a dotted line) formed between the wall 40 and the wall surface of the housing 2.

[0044] A flow path 51c (third flow path) through which the liquid refrigerant 20 can flow between the first region 61 and the second region 62 is provided in the lower part of the wall portion 40c. Similarly, a flow path 51d (fourth flow path) through which the liquid refrigerant 20 can flow between the first region 61 and the second region 62 is provided in the lower part of the wall portion 40d.

[0045] Furthermore, flow path 51c is provided with an openable / closable valve 50c (third valve) that allows the liquid refrigerant 20 to flow from the second region 62 toward the first region 61 and restricts the flow of liquid refrigerant 20 from the first region 61 toward the second region 62. Similarly, flow path 51d is provided with an openable / closable valve 50d (fourth valve) that allows the liquid refrigerant 20 to flow from the second region 62 toward the first region 61 and restricts the flow of liquid refrigerant 20 from the first region 61 toward the second region 62.

[0046] 9, the liquid level of liquid refrigerant 20 is inclined relative to the bottom surface so that it is higher at the front side of housing 2 and lower at the rear side. As in the front cross-sectional views described with reference to FIGS. 5 to 8, front valve 50c closes flow path 51c, preventing liquid refrigerant 20 from flowing from first region 61 to second region 62. Meanwhile, valve 50d opens flow path 51, allowing liquid refrigerant 20 to flow from second region 62 to first region 61. These actions suppress a decrease in the liquid level of liquid refrigerant 20 in first region 61, preventing electronic components 11 from being exposed to liquid refrigerant 20. [Example]

[0047] Next, a second embodiment will be described with reference to Figs. 10 and 11. Configurations common to the first embodiment will be assigned the same reference numerals, and detailed descriptions thereof will be omitted. Fig. 10 is an external perspective view of an electronic control device 1 according to the second embodiment of the present invention. Fig. 11 is a front cross-sectional view of the electronic control device 1 according to the second embodiment of the present invention when viewed from the normal direction of the circuit board 10.

[0048] In this embodiment, the housing 2 is open at the front, and a cover 3 is provided on the front side of the open housing 2. A circuit board 10 is mounted inside the space formed by the housing 2 and the cover 3, and electronic components 11 are mounted on the circuit board 10. The circuit board 10 is connected to other electronic control devices and the like via connectors and harnesses (not shown). In addition, a cooling water channel 33 that serves as a cooler is formed integrally with the housing 2 at the top. Cooling water inlets and outlets 32 are attached to both ends of the cooling water channel 33 for circulating cooling water 31 between the outside of the electronic control device 1 and the cooling water channel 33. A liquid refrigerant 20 is placed inside the housing 2.

[0049] The housing 2 is formed with walls 40 (40a, 40b) extending from the bottom surface (lower side) of the housing 2 toward the cooling water channel 33. In FIG. 11 , the wall 40 is formed with a wall 40a on the left side in the longitudinal direction of the circuit board 10 and a wall 40b on the right side. One (front) end of the left wall 40a and the right wall 40b contacts the inner wall of the housing 2, and the other (rear) end of the left wall 40a and the right wall 40b contacts the inner wall of the cover 3. The interior of the housing 2 is provided with a first area 61 formed by the inner walls of the walls 40a, 40b, the rear inner wall of the housing 2, and the rear inner wall of the cover 3, and in which the circuit board 10 is stored, and a second area 62 located on the left and right outside of the first area 61, and formed by the left and right inner walls of the housing 2, the outer walls of the walls 40a, 40b, the rear inner wall of the housing 2, and the rear inner wall of the cover 3. In other words, the first region 61 and the second region 62 are divided by the walls 40a and 40b.

[0050] A flow path 51a (first flow path) through which the liquid refrigerant 20 can flow between the first region 61 and the second region 62 is provided in the lower part of the wall portion 40a. Similarly, a flow path 51b (second flow path) through which the liquid refrigerant 20 can flow between the first region 61 and the second region 62 is provided in the lower part of the wall portion 40b.

[0051] Furthermore, flow path 51a is provided with an openable / closable valve 50a (first valve) that allows the liquid refrigerant 20 to flow from the second region 62 toward the first region 61 and restricts the flow of liquid refrigerant 20 from the first region 61 toward the second region 62. Similarly, flow path 51b is provided with an openable / closable valve 50b (second valve) that allows the liquid refrigerant 20 to flow from the second region 62 toward the first region 61 and restricts the flow of liquid refrigerant 20 from the first region 61 toward the second region 62.

[0052] Cooling water 31 cooled outside the electronic control device 1 to a temperature lower than the boiling point of the liquid refrigerant 20 circulates inside the cooling water channel 33. The liquid refrigerant 20 is heated and boils due to heat generated by the electronic components 11, and the boiled refrigerant 21 is cooled in the cooling water channel 33 located at an upper part inside the housing 2, and the cooled boiling refrigerant 21 is condensed to become condensed refrigerant and returns to the liquid refrigerant 20. The cooling water channel 33 is inclined downward from the center position in the left-right direction outward in the left-right direction.

[0053] 11, wall portions 40a and 40b are provided on their cooling water passage 33 sides with inclined portions 41a and 41b that are inclined so that the opposing wall portions 40a and 40b approach each other as they move toward (upward from) cooling water passage 33. As a result, the condensed refrigerant that is condensed in cooling water passage 33 and falls onto inclined portions 41a and 41b flows toward liquid refrigerant 20 that has accumulated in second region 62 along the slope of inclined portions 41a and 41b.

[0054] 11 shows a case where the liquid level of liquid refrigerant 20 is higher on the right side relative to the bottom surface of housing 2. At this time, pressure is applied from first region 61 to second region 62 to right valve 50b, causing flow path 51b to be closed, and liquid refrigerant 20 does not flow from first region 61 to second region 62. On the other hand, pressure is applied from second region 62 to first region 61 to left valve 50a, causing flow path 51a to be open, and liquid refrigerant 20 flows from second region 62 to first region 61. As a result, even if the liquid level of liquid refrigerant 20 tilts, a drop in the liquid level of liquid refrigerant 20 in first region 61 where the circuit board is stored can be prevented. [Example]

[0055] Next, a third embodiment will be described with reference to Figs. 12 to 15. Configurations common to the first and second embodiments are given the same reference numerals, and detailed descriptions thereof will be omitted. Fig. 12 is an external perspective view of an electronic control device 1 according to a third embodiment of the present invention. Fig. 13 is a cross-sectional view taken along line XIII-XIII on plane 71 shown in Fig. 12. Fig. 14 is a cross-sectional view taken along line XIV-XIV in Fig. 13. Fig. 15 is a cross-sectional view taken along line XV-XV in Figs. 13 and 14.

[0056] In this embodiment, four circuit boards 20 are stored inside the housing 2, and since the number of stored circuit boards 20 is increased, the thickness of the housing 2 in the front-to-rear direction is increased compared to Example 2.

[0057] Four circuit boards 10 are mounted in a line in the front-to-rear direction inside the space formed by the housing 2 and the cover 3, and electronic components 11 are mounted on the circuit boards 10. The circuit boards 10 are connected to each other and to other electronic control devices via connectors and harnesses (not shown). A cooling water channel 33 is formed in the top of the housing, and cooling water inlets and outlets 32 are attached to both ends of the cooling water channel 33 for circulating cooling water 31 between the outside of the electronic control device and the circuit boards 10. A liquid refrigerant 20 is placed inside the housing 2.

[0058] The housing 2 is formed with wall portions 40 (40a, 40b, 40c, 40d) extending from the bottom surface (lower side) of the housing 2 toward the cooling water passage 33 above.

[0059] As shown in FIG. 15 , the interior of the housing 2, in which the liquid refrigerant 20 is placed, is divided into five regions by a wall 40 disposed inside the housing 2. The interior is divided into a first region 61 in the center where the circuit board 10 is stored, and four second regions 62a, 62b, 62c, and 62d formed between the side wall of the housing 2 and the wall 40. The four corners of the housing 2 are sealed to prevent the liquid refrigerant 20 from entering. By sealing the corners, for example, the flow of the liquid refrigerant between the second region 62a and the second region 62d can be prevented, and a decrease in the liquid refrigerant in the first region 61 can be prevented when the liquid refrigerant level is tilted by the wall 40 and the valve 50, which will be described later.

[0060] Flow paths 51a, 51b, 51c, 51d are formed in the lower part of the wall portion 40 (40a, 40b, 40c, 40d) connecting the first region 61 and the second regions 62a, 62b, 62c, 62d, respectively, and valves 50a, 50b, 50c, 50d are installed in each of the flow paths 51a, 51b, 51c, 51d to allow the flow of liquid refrigerant 20 from the second region 62 toward the first region 61 and to restrict the flow from the first region 61 toward the second regions 62a, 62b, 62c, 62d.

[0061] Next, the flow of liquid refrigerant 20 in this embodiment will be described in detail. First, using Figure 13, a case will be described where liquid refrigerant 20 tilts and the height of liquid refrigerant 20 on the right side is higher. In this case, a flow similar to that shown in Figure 10 in the second embodiment occurs, and pressure is applied from second region 62a to first region 61 in valve 50a, causing valve 50a to open flow path 51a, and liquid refrigerant 20 flows from second region 62a to first region 61.

[0062] On the other hand, in valve 50b, pressure of liquid refrigerant 20 is applied from first region 61 to second region 62b, so valve 50b closes flow path 51b and no flow of liquid refrigerant 20 occurs. In addition, the liquid levels of liquid refrigerant 20 in second region 62c and second region 62d change in conjunction with the liquid level of liquid refrigerant 20 in first region 61. When condensed refrigerant condensed in cooling water channel 33 accumulates in second region 62c or second region 62d and becomes higher than the liquid level in first region 61, valve 50c or valve 50d opens to make the liquid level equal to that in first region 61. The action of these valves makes it possible to suppress a decrease in liquid refrigerant 20 in first region 61 even when the liquid level of liquid refrigerant 20 tilts.

[0063] 14, a case where the liquid refrigerant 20 tilts and the height of the liquid refrigerant 20 at the front side becomes higher will be described. At this time, pressure is applied from the second region 62c to the first region 61 in the valve 50d, causing the valve 50d to open the flow path 51d, and the liquid refrigerant 20 flows from the second region 62d to the first region 61.

[0064] Meanwhile, in valve 50c, pressure of liquid refrigerant 20 is applied from first region 61 toward second region 62c, causing valve 50c to close flow path 51c and restricting the flow of liquid refrigerant 20. The liquid level of liquid refrigerant 20 in second regions 62a and 62b changes in conjunction with the liquid level of liquid refrigerant 20 in first region 61. When condensed refrigerant 22 condensed in cooling water channel 33 accumulates in second region 62a or second region 62b and becomes higher than the liquid level in first region 61, valve 50a or valve 50b opens the flow path to make the liquid level equal to that in first region 61. The action of these valves makes it possible to suppress a decrease in liquid refrigerant 20 in first region 61 even when the liquid level of liquid refrigerant 20 tilts.

[0065] Next, a case will be described where the liquid refrigerant 20 enters without blocking the four corners of the housing 2. Fig. 16 is a cross-sectional view of a comparative example 1 compared to the structure of Fig. 15 .

[0066] As shown in FIG. 16 , the four corners of the housing 2 are divided into regions 622 by wall portions 40 (40a, 40b, 40c, 40d). Wall portions 40 in contact with region 622 are not provided with flow paths through which liquid refrigerant 20 can flow. In this case, even if the condensed refrigerant condensed in cooler 30 accumulates in region 622 and the liquid level of liquid refrigerant 20 in region 622 rises, liquid refrigerant 20 will not flow toward first region 61 unless it accumulates enough to overcome wall portions 40. Therefore, the amount of liquid refrigerant 20 in first region 61 decreases by the amount of liquid refrigerant 20 accumulated in region 622, and electronic components 11 may be exposed from liquid refrigerant 20.

[0067] FIG. 17 is a cross-sectional view of Comparative Example 2 compared to the structure of FIG. 15. In FIG. 17, flow paths 511 through which liquid refrigerant 20 can flow are provided in wall 40 (40a, 40b, 40c, 40d) that contacts region 622 at each of the four corners of housing 2. Providing flow paths 511 in wall 40 prevents liquid refrigerant 20 from continuously accumulating in region 622. However, if liquid refrigerant 20 tilts and flows from left to right, for example, flow 20a of liquid refrigerant 20 passes through valve 50a from second region 62a to first region 61, and flows 20d and 20e of liquid refrigerant 20 pass through flow paths 511 and flow toward second region 62b on the right. This reduces the amount of liquid refrigerant 20 in first region 61, potentially exposing electronic component 11 to liquid refrigerant 20.

[0068] 18 is one example of a method for preventing the liquid refrigerant 20 from flowing through these flow paths 511. Figures 18 and 19 are cross-sectional views of modifications of the third embodiment.

[0069] As shown in Fig. 18, in this modification, a valve 50e that allows the liquid refrigerant to flow only in the direction of the arrow in the figure is installed in flow path 511. By installing valve 50e on wall portion 40, even when liquid refrigerant 20 is tilted and a flow from left to right occurs, as shown in Fig. 19, valve 50e can prevent liquid refrigerant 20 from flowing toward second region 62b on the right side. Although this method has the disadvantage of increasing the number of valves installed and making the structure more complex, it can suppress a decrease in liquid refrigerant 20 in first region 61 even when the liquid level of the liquid refrigerant is tilted. [Example]

[0070] Next, a fourth embodiment will be described with reference to Figures 20 and 21. The same components as those in the first to third embodiments are designated by the same reference numerals, and detailed descriptions thereof will be omitted. Figure 20 is a front cross-sectional view of an electronic control device 1 according to a fourth embodiment of the present invention, as viewed from the normal direction of a circuit board 10.

[0071] In this embodiment, no valves are installed in the walls 40a, 40b that divide the first region 61 and the second region 62, and instead, flow paths 51a, 51b are provided that allow the liquid refrigerant 20 to flow between these regions. The opening areas of the flow paths 51a, 51b are adjusted according to the thickness of the wall 40. In this embodiment, the diameters of the openings of the flow paths 51a, 51b are smaller than the thickness of the wall 40a, 40b, which corresponds to the lengths of the flow paths 51a, 51b. According to this embodiment, the above-described configuration increases the flow loss that occurs when the liquid refrigerant 20 flows through the flow paths 51a, 51b, thereby restricting the flow of the liquid refrigerant 20 between the first region 61 and the second region 62. This makes it possible to suppress a decrease in the liquid refrigerant 20 in the first region 61 even when the liquid level of the liquid refrigerant 20 is tilted. In FIG. 20, the flow paths 51a and 51b are depicted as one opening in each of the wall portions 40a and 40b, but they may be a plurality of holes or may be lattice-shaped openings.

[0072] Fig. 21 is a cross-sectional view of a modified example of the fourth embodiment. In the modified example of Fig. 21, the flow paths 51a and 51b are formed in a cylindrical shape. The length of the cylindrical flow paths 51a and 51b is thicker (larger) than the thickness of the wall portions 40a and 40b. However, the inner diameter of the cylindrical flow paths 51a and 51b is smaller than the length of the cylindrical flow paths 51a and 51b. This makes it possible to obtain the same effects as those of the fourth embodiment.

[0073] In this embodiment, a valve may be disposed in either one of the flow paths 51a and 51b. [Example]

[0074] Next, a fifth embodiment will be described with reference to Figures 22 and 23. The same components as those in the first to fourth embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. Figure 22 is a front cross-sectional view of an electronic control device 1 according to a fifth embodiment of the present invention, as viewed from the normal direction of a circuit board 10.

[0075] In this embodiment, flow paths 51a and 51b between first region 61 and second region 62 are configured as groove-like passages recessed in the bottom of housing 2, rather than as openings provided in the wall surface of wall portion 40. As in the fourth embodiment, by adjusting the opening area and length of flow path 51 formed in the bottom of housing 2 to change the flow loss of liquid refrigerant 20, it is possible to suppress a decrease in liquid refrigerant 20 in first region 61 even when the liquid level of liquid refrigerant 20 is tilted.

[0076] FIG. 23 is an enlarged view of the bottom of an electronic control device 1 according to a modified example of the fifth embodiment of the present invention. In FIG. 23, valves 50a and 50b are installed in flow paths 51a and 51b, respectively, in the electronic control device shown in FIG. 22. The valves 50a and 50b are installed at the inlet and outlet portions of the flow paths 51a and 51b on the first region 61 side. The valves 50a and 50b allow the liquid refrigerant 20 to flow from the second region 62 to the first region 61 and restrict the liquid refrigerant 20 from the first region 61 to the second region 62. The valve 50a is shown in an open state when pressure of the liquid refrigerant 20 is applied from the second region 62 to the first region 61, allowing a flow 20a of the liquid refrigerant 20 from the second region 62 to the first region 61. Valve 50b also shows a state in which pressure of liquid refrigerant 20 is applied from first region 61 to second region 62. In this case, valve 50b closes flow path 51b, thereby restricting the flow 20b of liquid refrigerant 20 and preventing electronic component 11 from being exposed to liquid refrigerant 20. [Example]

[0077] Next, a sixth embodiment will be described with reference to Figures 24 to 29. Configurations common to the first to fifth embodiments are assigned the same reference numerals, and detailed descriptions thereof will be omitted. Figure 24 is a front cross-sectional view of an electronic control device 1 according to a sixth embodiment of the present invention, as viewed from the normal direction of the circuit board 10. In this embodiment, a third region 63 connected to the second region 62 is added to the electronic control device, and unlike the structures shown in the first to fifth embodiments, the interior of the electronic control device is not sealed but is open to the atmosphere.

[0078] 24 is located outside the second region 62, and is connected to the second region 62 (shown by the dashed line) at the bottom by a second flow path 512 through which the liquid refrigerant can flow. An opening is provided at the top of the third region 63, and the third region 63 has an atmosphere opening 64 that connects to the atmosphere outside the electronic control device.

[0079] The second flow path 512 is provided at a position where it is immersed in the liquid refrigerant 20. As a result, the boiling refrigerant filling the upper part of the second region 62 does not flow out into the atmosphere through the atmosphere opening 64 through the third region 63 because the liquid refrigerant 20 functions as a lid, thereby preventing a decrease in the liquid refrigerant 20. The water level of the liquid refrigerant 20 in the third region 63 is at a height where the pressure acting on the liquid refrigerant 20 in the second region 62 and the atmospheric pressure acting on the liquid refrigerant 20 in the third region 63 are balanced. An air filter or the like that allows air to flow may be attached to the atmosphere opening.

[0080] A first area 61 (shown by a dashed line) and a second area 62 are separated by walls 40a, 40b, and a circuit board 10 on which heat-generating electronic components 11 are mounted is disposed in the first area 61. The electronic components 11 are immersed in a liquid refrigerant 20, and the heat generated by the electronic components 11 causes the liquid refrigerant 20 to boil. The boiling refrigerant 21 is cooled and condensed by a cooler 30 disposed on the top of the housing 2, and returns to the liquid refrigerant 20 as a condensed refrigerant 22. Cooling water 31 flows inside the cooler 30.

[0081] Valves 50a and 50b are provided at the bottom of wall 40 to allow liquid refrigerant 20 to flow from second region 62 to first region 61 and to restrict the flow of liquid refrigerant 20 from first region 61 to second region 62. Valves 50a and 50b open and close flow paths 51a and 51b, which serve as first passages. The function of these valves is to prevent a decrease in liquid refrigerant 20 in first region 61 even if the liquid level of liquid refrigerant 20 fluctuates, thereby preventing electronic components 11 from being exposed to liquid refrigerant 20.

[0082] Fig. 25 is a cross-sectional view of a first modified example of the sixth embodiment. In Fig. 25, the third region 63 is an electronic control device configured with a tubular connecting pipe 65. The connecting pipe 65 is provided in the second region 62. The lower part of the connecting pipe 65 is immersed in the liquid refrigerant 20, and the inside of the pipe is connected to the liquid refrigerant 20. The upper part of the connecting pipe 65 extends to the outside of the housing 2 and the cover 3, and the tip of the upper part is connected to the atmosphere through an atmospheric opening 64. The electronic control device of this embodiment can also be configured with such a tubular structure.

[0083] Fig. 26 is an external perspective view of the electronic control device 1 according to the second modification of the sixth embodiment. Fig. 27 is a cross-sectional view taken along the line XXVII-XXVII cut at the plane 71 shown in Fig. 26. The electronic control device 1 according to the second modification of the sixth embodiment is obtained by adding the structure of the third region 63 to the electronic control device shown in the third embodiment.

[0084] The third region 63 is connected to the second region 62 at its bottom by a second flow path 512 through which the liquid refrigerant 20 can flow. An opening is provided at the top of the third region 63, and the third region 63 has an atmospheric opening 64 that connects to the atmosphere outside the electronic control device. The third region 63 is formed integrally with the housing 2. The third region 63 is formed so as to be thinner in the direction perpendicular to the paper surface of FIG. 27, thereby reducing the amount of liquid refrigerant 20 that accumulates in the third region 63. A cooling water path 33 is formed in the housing 2, which cools the boiling refrigerant 21.

[0085] Fig. 28 is an external perspective view of an electronic control device 1 according to a third modification of the sixth embodiment. Fig. 29 is a cross-sectional view taken along the line XXIX-XXIX cut by the plane 71 shown in Fig. 28. In the electronic control device 1 according to the third modification of the sixth embodiment, the third region 63 is formed by a cylindrical connecting pipe 65. The lower end of the connecting pipe 65 is connected to the second region 62, and the third region 63 is formed by the space inside the connecting pipe 65. The upper end of the connecting pipe 65 is connected to the atmosphere through an atmospheric opening 64. In these figures, the connecting pipe 65 is arranged along the outer side surface of the housing 2, but the connecting pipe 65 may also be arranged to pass through the inside of the housing 2 as shown in Fig. 25. [Example]

[0086] Next, a seventh embodiment will be described with reference to Figures 30 and 31. Components common to the first to sixth embodiments are assigned the same reference numerals, and detailed descriptions thereof will be omitted. Figure 30 is a partially enlarged cross-sectional view of a wall 40 of an electronic control device 1 according to a seventh embodiment of the present invention. In the seventh embodiment, the valve 50 described in the first to sixth embodiments has a different structure. In Figure 30, the right side of the wall 40 is a first region 61, and the left side of the wall 40 is a second region 62. A flow path 51 communicating the first region 61 and the second region 62 is formed in the wall 40. The wall 40 is provided with a lid-shaped valve 52 that opens and closes the flow path 51.

[0087] 30(a) shows the state in which the valve 52 is open. When the pressure of the liquid refrigerant 20 in the second region 62 is higher than the pressure in the first region 61, the valve 52 moves to the right, creating a gap in the flow path 51. This gap allows the liquid refrigerant 20 to flow 20a from the second region 62 toward the first region 61.

[0088] 30(b) shows the state in which the valve is closed. When the pressure of the liquid refrigerant in the first region 61 is higher than the pressure in the second region 62, the valve 52 is pressed to the left, so no gap is created in the flow path 51 and the flow 20b of the liquid refrigerant 20 is obstructed.

[0089] Fig. 31 is a cross-sectional view of a modified example of Example 7. In Fig. 31, the valve is configured as a water wheel that can rotate only in one direction. In Fig. 31, the right side of the wall portion 40 is a first region 61, and the left side of the wall portion 40 is a second region 62. In Fig. 31, the water wheel 53 is structured so that it can rotate only counterclockwise, and a flow path 51 that connects the first region 61 and the second region 62 is formed below the water wheel 53.

[0090] 31(a) shows a state in which the water wheel 53 is rotating and the valve is open. When the pressure of the liquid refrigerant in the second region 62 is higher than the pressure in the first region 61, a force that rotates the water wheel 53 counterclockwise is applied, allowing the water wheel 53 to rotate. As a result, a flow 20a of the liquid refrigerant can flow from the second region 62 to the first region 61.

[0091] 31(b) shows a state in which the water turbine 53 is stopped and the valve is closed. When the pressure of the liquid refrigerant in the first region 61 is higher than the pressure in the second region 62, a force acts on the water turbine 53 to rotate it clockwise, but the water turbine does not rotate because it is designed to rotate only counterclockwise. As a result, the flow 20b of the liquid refrigerant 20 from the first region 61 to the second region 62 is restricted.

[0092] The present disclosure is not limited to the above-described embodiments and modifications. For example, it is possible to replace part of the configuration of the above-described embodiments and modifications with other configurations, or to combine the configurations of the above-described embodiments and modifications. It is also possible to add, delete, or replace part of the configuration of the above-described embodiments and modifications with other configurations. In the present disclosure, the wall portion 40 is arranged to consist of at least two of the four sides surrounding the circuit board 10, but the wall portion 40 may consist of only one side. [Explanation of symbols]

[0093] 1...electronic control device, 2...housing, 3...cover, 10...circuit board, 11...electronic component, 20...liquid refrigerant, 21...boiling refrigerant, 22...condensed refrigerant, 23...exposed portion, 30...cooler, 31...cooling water, 33...cooling water channel, 40, 40a, 40b, 40c, 40d...wall portion, 41a, 41b...inclined portion, 50, 50a, 50b, 50c, 50d, 50e...valve, 51, 51a, 51b, 51c, 51d...flow path, 61...first region, 62...second region, 63...third region, 65...connecting pipe

Claims

1. An electronic control device mounted on a moving body, a circuit board on which electronic components are mounted; a housing that accommodates the circuit board and a liquid refrigerant; a cooler disposed in an upper portion within the housing; a wall portion extending from a bottom portion of the housing toward the cooler and dividing the inside of the housing into a first region and a second region; the circuit board is immersed in the liquid coolant within the first region; At least two flow paths are formed in the housing, the flow paths connecting the first region and the second region; The flow path is provided with a valve that allows the liquid refrigerant to flow from the second region toward the first region and restricts the liquid refrigerant to flow from the first region toward the second region.

2. 2. The electronic control device according to claim 1, The electronic control device is characterized in that the flow path and the valve are provided in the wall portion.

3. 2. The electronic control device according to claim 1, The electronic control device is characterized in that the flow path and the valve are provided at the bottom of the housing.

4. 2. The electronic control device according to claim 1, The electronic control device is characterized in that the valve is composed of a water wheel that rotates only by the liquid refrigerant flowing from the first region to the second region.

5. 2. The electronic control device according to claim 1, The electronic control device, wherein the wall portions have inclined portions that are inclined so that the opposing wall portions approach each other toward the cooler.

6. 6. The electronic control device according to claim 5, 10. An electronic control device, wherein a lower surface of the cooler is inclined downward from a center portion of the cooler toward an outer periphery thereof.

7. 7. The electronic control device according to claim 6, The electronic control device is characterized in that the cooler is formed integrally with the housing.

8. 2. The electronic control device according to claim 1, a third region located outside the second region and communicating with the second region; An electronic control device, wherein an upper portion of the third area is open.

9. 2. The electronic control device according to claim 1, The electronic control device is characterized in that the second region is provided with a connecting pipe whose lower part is immersed in the liquid refrigerant and whose upper part is open to the atmosphere.

10. An electronic control device mounted on a moving body, a circuit board on which electronic components are mounted; a housing that accommodates the circuit board and a liquid refrigerant; a cooler disposed on an upper surface of the housing; a wall portion extending from a bottom portion of the housing toward the cooler and dividing the inside of the housing into a first region and a second region; the circuit board is immersed in the liquid coolant within the first region; At least two flow paths are formed in the housing, the flow paths connecting the first region and the second region; The electronic control device according to claim 1, wherein the diameter of the opening of the flow path is smaller than the length of the flow path, thereby restricting the flow of the liquid refrigerant from the first region toward the second region.

Images