Patent Application
20250142790
The present invention relates to an electronic controller.
As development of an autonomous driving ECU (Electronic Control Unit) and an integrated ECU progresses, the higher performance of ECUs has resulted in increasing heat generation by the ECUS. Consequently, a housing of an electronic controller now needs a cooling structure with performance higher than that of a conventional cooling structure. When the amount of heat generated by electronic components exceeds 10 W, in particular, forced air cooling is an essential means for cooling. Thus, an electronic controller equipped with a fan has been developed (e.g., Patent Literature 1).
PTL 1: JP 2018-206964 A
A process of mounting the fan on the electronic controller of Patent Literature 1 is very complicated. For example, to ensure its waterproof performance, the fan needs to be attached to a fan attachment opening formed on the wall of a case, using a sealing material. In addition, a terminal of the fan needs to be inserted into a hole (through-hole) formed on a circuit board and soldered to the circuit board.
Because the resulting structure is a structure in which the vibration of the fan is directly transmitted to solder electrically connecting the terminal of the fan to the circuit board, there is a concern that a contact failure may occur at the solder serving as a connection member between the terminal of the fan and the circuit board because of fine sliding wear of the solder.
An object of the present invention is to provide an electronic controller that can achieve an improvement in assembly work efficiency and an improvement in the reliability of electrical connections.
In order to achieve the above object, an electric controller of the present invention includes: a circuit board; a housing that houses the circuit board; a plurality of radiation fins formed on the housing; an air duct attached to the housing in such a way as to cover the plurality of radiation fins, the air duct forming a channel for cooling air together with the housing and the plurality of radiation fins; a fan that causes cooling air to flow through the channel; a fan connector electrically connected to the fan via a cable; and a feeder connector electrically connected to the circuit board and fixed to the housing. The fan connector is detachably connected to the feeder connector, and the fan and the fan connector are fixed to the air duct.
According to the present invention, an improvement in assembly work efficiency and an improvement in the reliability of electrical connections can be achieved. Problems, configurations, and effects other than those described above will be made clear by the following description of embodiments.
Hereinafter, configurations and operations of electronic controllers according to first to fifth embodiments of the present invention will be described with reference to the drawings.
The electronic controller 1, which is a type of computer, is an electronic control unit (ECU) that is incorporated in an automobile by being mounted to its structure. The electronic controller 1 is mounted to, for example, an engine room of the automobile.
As shown in
The base 21 is one of components making up the housing 2, and is formed of, for example, an aluminum plate material or die-cast aluminum. On the back of a surface of the base 21 that bears the circuit board 7, a plurality of radiation fins 21a (see
The plurality of radiation fins 21a are formed by, for example, skiving (slice-cutting the surface layer to raise a sliced part with its base bent (scraping)). The plurality of radiation fins 21a may be formed by casting.
The base 21 is provided with a rectangular through-hole 21b that allows a feeder connector 7b fixed to the circuit board 7 to project toward the fan connector 8a.
The cover 22 is one of components making up the housing 2 and is a component that covers the circuit board 7. The circuit board 7 is attached to the cover 22 with, for example, a screw 23. The cover 22 and the base 21 are fitted together with screws 4f or the like for attaching the air duct 4, which will be described later, to the cover 22, thus forming the housing 2 that houses the circuit board 7.
As a material making up the cover 22, for example, a resin like polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or nylon (PA) may be used, in which case the weight of the cover 22 can be reduced. A metal, such as aluminum or iron, may be used as the material to improve the cooling performance or rigidity of the cover 2.
The sealing material 6 is a component for waterproofing the housing 2. It is preferable, for example, that the sealing material 6 be sandwiched between the base 21 and the cover 22. As the sealing material 6, for example, an adhesive made of a silicon-based material, an epoxy-based material, or a urethane-based material or an O-ring made of a rubber-based material can be used.
The circuit board 7 is a printed board, on which an electronic component 7a, the external connection connector 3, and the feeder connector 7b, which will be described later, are electrically connected to holes (through-holes) formed on the circuit board 7, by soldering, press fitting, spot flow, or the like. The circuit board 7 is provided with a through-hole 7c, and is fixed to the cover 22 with a screw 23 or the like inserted into the through-hole 7c.
The electronic component 7a, which is a component making up an electronic circuit, is an integrated circuit carrying a package of heat-generating elements like semiconductor elements, such as a ball grid array (BGA) or a quad flat package (QFP).
The external connection connector 3 is made of resin, such as polybutylene terephthalate (PBT), polyamide (PA), or polyphenylene sulfide (PPS). The external connection connector 3 has a plurality of connector terminals made mainly of a copper-based metal, and is connected to a connector (not illustrated) on the front end of a harness extending from a communication counterpart device on the automobile side. The connector terminal is a terminal for supplying and receiving voltage and current to and from a connection counterpart, and is electrically connected to an electronic circuit formed on the circuit board 7, via a cable.
The external connection connector 3 is exposed from the housing. It is preferable that the sealing material 6 be sandwiched between the external connection connector 3 and base 21 and the cover 22 to prevent water infiltration. Thus, the periphery of the external connection connector 3 is waterproofed with the sealing material 6.
The feeder connector 7b is a connector for supplying power to the fan 8, and is attached to, for example, the back of a surface of the circuit board 7 that bears the electronic component 7a.
The air duct 4 is a component that is attached to the housing 2 in such a way as to cover the plurality of radiation fins 21a formed on the base 21 and that forms a channel for cooling air (which will hereinafter be referred to as a cooling air channel in some cases), together with the housing 2 and the plurality of radiation fins 21a. The air duct 4 is fixed to the housing 2 with the screws 4f. The cooling air channel is formed along the plurality of radiation fins 21a.
The air duct 4 is provided with openings 4a and 4b for taking in and discharging cooling air, a fan fixing portion 4c, which is a recession in which the fan 8 is fitted (fixed), a connector fixing portion 4d, which is a recession in which the fan connector 8a is fitted (fixed), and a cable storage portion 4e, which is a recession in which a cable is stored. The air duct 4 is formed of resin, such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or nylon (PA), or of die-cast aluminum. For this reason, the fan fixing portion 4c and the connector fixing portion 4d can be easily molded in conformity to the shapes of the fan 8 and the fan connector 8a to be fixed.
The fan 8 is a component that causes a gas to flow in the cooling air channel, and is fixed to the air duct 4 and electrically connected to the fan connector 8a. As the fan 8, for example, a thin blower fan with an aluminum die-cast frame or resin frame can be used. Because the fan fixing portion 4c of the air duct 4 can be easily molded in conformity to the shape of the fan 8 to be fixed, the fan 8 may be provided as a general-purpose product, in which case cost can be reduced.
The fan connector 8a is an electric component detachably connected to the feeder connector 7b. The fan connector 8a is fixed to the air duct 4, is electrically connected to the feeder connector 7b, and supplies power to the fan 8 via cables 8c. The fan connector 8a is formed of resin, such as polybutylene terephthalate (PBT), polyamide (PA), or polyphenylene sulfide (PPS), and has a plurality of built-in female terminals made mainly of copper. As shown in
Fixing the fan 8 and the fan connector 8a to the air duct 4 forms an assembly, which is referred to as a subassembly 48. The subassembly 48 is attached to the housing 2, forms the cooling air channel between the subassembly 48 and the housing 2, and causes a gas to flow through the channel when the fan 8 supplied with current runs.
The brackets 5 are components for fixing the electronic controller 1 to the vehicle, and are attached to the housing 2 with, for example, screws 5a. The brackets 5 may be molded integrally with the housing 2.
It is also preferable that, as described above, the electronic controller 1 include the sealing material 6 disposed between the base 21 and the cover 22 that make up the housing 2 and between a set of the base 21 and the cover 22 and the external connection connector 3. It is also preferable that a sealing material 6a be disposed in a gap formed between the through-hole 21b of the base 21 and the feeder connector 7b. It is also preferable that a potting material be applied to an electrical connection part between the fan connector 8a and the cables 8c. It is also preferable that the fan 8 be a waterproof fan. These configurations make the electronic controller 1 waterproof. It should be noted that the electronic controller 1 can be selectively made waterproof or dustproof, depending on whether or not to use the sealing materials 6 and 6a, the potting material, and the waterproof fan, and that the type of the electronic controller 1 can be easily changed according to a location where the electronic controller 1 is installed.
It is preferable that the air duct 4 be provided with a cable storage portion 4e in which a surplus part (extra length part) of the cable 8c is stored. It is also preferable that the air duct 4 be provided with an attachment surface limiting structures 4g that limit an attachment surface of the fan 8 (i.e., a surface of the fan 8 that faces the air duct 4 when the fan 8 is attached to the air duct 4). The attachment surface limiting structures 4g limit the attachment surface in accordance with the shape of the fan 8. As shown in
As shown in
To arrange the plurality of cables 8c along the slot 4da by the projection Bac and insert the claw 8ab securely into the latch receiver 4dc, a gap smaller than the wire diameter of the cable 8c is formed between the front end of the projection 8ac and the bottom surface 4dc of the slot 4da. In this embodiment, the wire diameter of the cable 8c is 0.9 mm, and the gap between the front end of the projection 8ac and the bottom surface 4dc of the slot 4da is 0.5 mm. Because the gap is formed between the front end of the projection 8ac and the bottom surface 4dc of the slot 4da, the fan connector 8a comes in contact with the pair of supports 4de of the connector fixing portion 4d and is supported by the supports 4de. When, because of a manufacturing error or the like, the fan connector 8a is inserted into the slot 4da without coming in contact with the pair of supports 4de of the connector fixing portion 4d, however, the front end of the projection 8ac comes in contact with the bottom surface 4dc of the slot 4da. This prevents a case where the cables 8c are sandwiched between the bottom surface 8ae of the fan connector 8a and the bottom surface 4dc of the slot 4da.
It is preferable that the electronic controller 1 of this embodiment further include a temperature sensor and that the rotating speed of the fan 8 be controlled based on a detection value from the temperature sensor. It is preferable, for example, that the electronic controller 1 include a temperature sensor incorporated in the electronic component 7a and that the rotation speed of the fan 8 be controlled based on a detection value from the temperature sensor incorporated in the electronic component 7a (that is, the temperature of an area around the electronic component 7a). It is also possible that the temperature sensor is mounted on the circuit board 7 and that the rotating speed of the fan 8 is controlled based on a detection value from the temperature sensor (that is, the temperature of an area around the temperature sensor mounted on the circuit board 7). It is preferable that the cables 8c, i.e., the plurality of cables 8c include the cable 8cc through which a rotating speed instruction (e.g., a PWM signal) to the fan 8 is transmitted and the cable 8cd through which a detection signal from a rotating speed sensor attached to the fan 8 is transmitted.
Specifically, it is preferable that, as shown in
Specifically, it is preferable that the feeder connector 7b include board-side terminals 7ba (see
It is preferable that the board-side terminals 7ba be connected to the surface of the circuit board 7 or inserted into through-holes 7d of the circuit board 7 and be fitted and electrically connected to the circuit board 7 by, for example, press fitting or spot flow soldering. It is preferable that the fan-side terminals 7bb be fitted and electrically connected to the fan connector 8a when the subassembly 48 is attached to the housing 2.
The plate-shaped part 7bc covers the through-hole 21b and is in contact with the base 21. It is preferable that on a surface of the plate-shaped part 7bc that faces the base 21, a groove 7bd be formed along the circumferential direction of a box-shaped member 7be in which the fan-side terminals 7bb are housed and that the sealing material 6a be applied to the groove 7bd.
The sealing material 6a (see
In the electronic controller 1 of this embodiment, the fan 8 and the fan connector 8a are fixed to the air duct 4 to form the subassembly 48. Therefore, by attaching the subassembly 48 to the housing 2 and electrically connecting the feeder connector 7b and the fan connector 8a to each other, the fan 8 can be incorporated in the electronic controller 1. This makes a process of incorporating the fan 8 into the electronic controller 1 simpler, thus improving work efficiency.
The circuit board 7 and the fan 8 are electrically connected to each other via the cables 8c, the fan connector 8a, and the feeder connector 7b. Because of this structure, the vibration of the fan 8 is not directly transmitted to the circuit board 7. As a result, a contact failure of the electrical connection part between the blower fan 8 and the circuit board 7, the contact failure being caused by fine sliding wear, can be prevented, and therefore the reliability of electrical connection between the fan 8 and the circuit board 7 can be improved.
In addition, in a case where the air duct 4 is manufactured in conformity to the shapes of the fan 8 and the fan connector 8a so that the fan 8 and the fan connector 8a can be fixed, the fan 8 and the fan connector 8a can be provided as general-purpose products, which allows a reduction in the manufacturing cost.
It is preferable that in the electronic controller 1 of this embodiment, the fan 8 be disposed downstream to the plurality of radiation fins 21a in the cooling air channel. This allows cooling air to flow through between individual pairs of adjacent radiation fins 21a of the plurality of radiation fins 21a, thus allowing an improvement in the cooling performance. In addition, designing a channel for uniformly sending cooling air to the entire electronic controller becomes easy.
It is also preferable that in the electronic controller 1 of this embodiment, the fan 8 be a blower fan. Because the blower fan is thin, using the blower fan can prevent an increase in the thickness of the electronic controller 1.
It is also preferable that the electronic controller 1 of this embodiment include the gap G1 formed between the front ends 21aa of the plurality of radiation fins 21a and the air duct 4. This prevents a case where the front ends 21aa of the plurality of radiation fins 21a butt against the air duct 4 due to an assembly error or the like, thus suppressing deformation of the plurality of radiation fins 21a. It is also preferable that the size of the gap G1 be set so that the flow rate of cooling air flowing through the gap between the air duct 4 and the front ends 21aa of the plurality of radiation fins 21a becomes smaller than the flow rate of cooling air flowing through the gap G2 between two adjacent radiation fins 21a among the plurality of radiation fins 21a. This reduces the amount of a gas flowing through the gap G1 between the air duct 4 and the front ends 21aa of the plurality of radiation fins 21a, the gas not contributing to cooling, and increases the amount of a gas flowing through the gap G2 between two adjacent radiation fins 21a among the plurality of radiation fins 21a, the gas contributing to cooling, and therefore allows an improvement in the cooling efficiency.
It is preferable that the electronic controller 1 of this embodiment include the attachment surface limiting structures 4g that limit the attachment surface of the fan 8. This prevents a case where the fan 8 is attached to the air duct 4, with the attachment surface set at a wrong position. Labor the work of attaching the fan 8 to the air duct 4 requires, therefore, can be reduced, and the occurrence of a product failure can be suppressed.
It is preferable that in the electronic controller 1 of this embodiment, the fan connector 8a and the air duct 4 be provided with the latch mechanism (the latch locking part 8aa and the latch engagement part 4db) that couples the fan connector 8a and the air duct 4 to each other. This allows the fan connector 8a to be easily attached and fixed to the air duct 4, thus allowing an improvement in the work efficiency.
It is preferable that in the electronic controller 1 of this embodiment, the cable 8c be 5 cm to 15 cm in length. This makes the work of connecting the cable 8c to the connector easy, thus allowing an improvement in the work efficiency.
It is preferable that in the electronic controller 1 of this embodiment, the air duct 4 be provided with the cable storage portion 4e in which the cables 8c are stored. This allows the extra length parts of the cables 8c to be easily stored in the cable storage portion 4e, thus allowing an improvement in the work efficiency. In addition, when the subassembly 48 is attached to the housing 2, the cables 8c being sandwiched between the air duct 4 and the housing 2 is prevented and therefore damaging the cables 8c is prevented.
It is preferable that in the electronic controller 1 of this embodiment, the feeder connector 7b be attached to the circuit board 7. This connects the feeder connector 7b to the circuit board 7 at the shortest distance, thus allowing an improvement in electrical connection reliability.
It is preferable that in the electronic controller 1 of this embodiment, the feeder connector 7b be inserted into the through-hole 21b formed on the housing 2 (base 21) and the sealing material 6a be disposed in the gap formed between the through-hole 21b and (the plate-shaped part 7bc of) the feeder connector 7b. In this structure, the gap between the through-hole 21b of the base 21 and the plate-shaped part 7bc can be waterproofed by the sealing material 6a. As a result, a waterproof structure of the housing can be achieved.
It is preferable that the electronic controller 1 of this embodiment include the temperature sensor (e.g., the temperature sensor incorporated in the electronic component 7a mounted on the circuit board 7) and that the rotating speed of the fan 8 be controlled based on a detection value from the temperature sensor. Because of this, the rotating speed of the fan 8 can be controlled based on the temperature of an area around the temperature sensor (the temperature of an area around the electronic component 7a when the temperature sensor is incorporated in the electronic component 7a) included in the electronic controller 1. In a low temperature condition, for example, the rotating speed of the fan 8 can be reduced and therefore overall noise can be reduced.
The electronic controller 1 of this embodiment including the sealing material 6a disposed in the gap between the feeder connector 7b and the housing 2 may further include the sealing material 6 disposed between the base 21 and the cover 22 and between the set of the base 21 and the cover 22 and the external connection connector 3, and the potting material applied to the electrical connection part between the fan connector 8a and the cables 8c. In this electronic controller 1, the fan 8 may be a waterproof fan. This makes the electronic controller 1 waterproof and therefore allows the electronic controller 1 to be mounted outside the vehicle interior.
In the electronic controller 1 of this embodiment, the electronic component 7a mounted on the circuit board 7 is heat-conductively connected to the plurality of radiation fins 21a via the thermal vias 7g connecting the board surface 7e and the back surface 7f of the circuit board 7 and the heat-dissipating grease 21d applied between the circuit board 7 and the housing 2 (base 21). As a result, heat from the electronic component 7a can be released out of the electronic controller 1 by cooling air flowing through the air duct 4 via the thermal vias 7g, the heat-dissipating grease 21d, and the plurality of radiation fins 21a. Heat dissipation performance, therefore, can be improved.
It is preferable that in the electronic controller 1 of this embodiment, the projection 8ac projecting toward the bottom surface 4dc be formed on the bottom surface Bae of the fan connector 8a (the surface of the fan connector 8a that faces the slot 4da) along the slot 4da, the bottom surface 8ae being in contact with the pair of supports 4de. It is also preferable that the plurality of cables 8c led out of the bottom surface 8ae be arranged along the slot 4da by the projection 8ac. This prevents entanglement of the plurality of cables 8c. Even if, because of a manufacturing error or the like, the fan connector 8a is inserted into the slot 4da without coming in contact with the pair of supports 4de of the connector fixing portion 4d, the front end of the projection Bac comes in contact with the bottom surface 4dc of the slot 4da. This prevents a case where the plurality of cables 8c arranged in the slot 4da are sandwiched between the bottom surface Bae of the fan connector 8a and the bottom surface 4dc of the slot 4da. In addition, a gap is formed between the front end of the projection Bac and the bottom surface 4dc of the slot 4da. As a result, the plurality of cables 8c can be arranged along the slot 4da by the projection 8ac, and the claw 8ab can be inserted securely into the latch receiver 4dc.
It is preferable that in the electronic controller 1 of this embodiment, the plurality of radiation fins 21a are formed by skiving. This improves the cooling performance of the plurality of radiation fins 21a, thus allowing an improvement in the cooling performance of the electronic controller 1.
In the electronic controller 201 of this embodiment, the fan is the axial fan 208. The axial fan 208 increases the volume of cooling air, thus improving the cooling performance.
The air duct 204 of this embodiment is provided with the attachment surface limiting structures 204b. As a result, if the axial fan 208 with its attachment surface in a wrong position is attached to the air duct 204, the attachment surface limiting structures 204b interfere with the vanes of the axial fan 208, which renders the axial fan 208 incapable of rotating. This prevents a case where the axial fan 208 with its attachment surface in a wrong position is attached to the air duct 204. Hence labor the work of attaching the axial fan 208 to the air duct 204 requires can be reduced and occurrence of a product failure can be suppressed.
It is preferable that the electronic controller 201 of this embodiment include the fan provided as the axial fan 208 and further include the brackets 205 for attaching the electronic controller 201 to the attachment target S, and that the brackets 205 hold the distance between the exhaust port 204c of the air duct 204 and the attachment target S at the given value (e.g., 15 mm or more which is the distance that does not hamper air discharge by the axial fan 208). This provides the distance that does not hamper air discharge by the axial fan 208, between an installation surface S and the exhaust port of the axial fan 208. As a result, the idling of the axial fan can be prevented.
It is preferable that in the electronic controller of this embodiment, the fans 8 be the plurality of fans 8 and that even if any one of the plurality of fans 8 fails, the remaining normal fan(s) 8 run continuously. Even if one fan 8 fails, the other fans 8 keep rotating. The cooling function, therefore, can be maintained.
It is preferable that, different from the electronic controller 1 according to the first embodiment, the electronic controller 401 according to the fourth embodiment include a blind portion 404b on an air duct 404, the blind portion 404b masking out a plurality of radiation fins 21a to make them invisible, as shown in
It is preferable that, in the electronic controller 401 according to this embodiment, the air intake port 404a of the air duct 404 be open in a direction different from the direction of the cooling air CA flowing through gaps between the plurality of radiation fins 21a. It is also preferable that the plurality of radiation fins 21a be masked with the blind portion 404b. This prevents a case where a foreign object, such as dust and pebbles, is sucked into the air intake port 404a and hits the fan 8 or 208 located downstream to the plurality of radiation fins 21a. Failure incidents of the fan, therefore, can be reduced.
It is also particularly preferable that the air intake port 404a be open in the direction perpendicular to the direction of the cooling air flow on the side opposite to the cover 422 with respect to the cooling air flow. In this case, the opening area of the air intake port 404a can be made larger than a case where the air intake port 404a is open on a different side, and therefore a drop in the cooling performance can be suppressed.
The attachment position limiting structure 501a shown in
The first projection 622a is provided with through-holes 622b, and the second projection 604a is provided with screw holes 604b. The first projection 622a and the second projection 604a are fitted together and then positioning screws 601b are put through the through-holes 622b and are screwed down into the screw holes 604b. Hence an attachment position between a housing 602 and the air duct 604 is limited. The first projection 622a may be formed on the base 621 in the same manner as the guide 502b shown in
In the electronic controller according to this embodiment, the housings 502 and 602 and the air ducts 504 and 604 are provided with the attachment position limiting structures 501a and 601a that limit the attachment positions between the housing 502 and 602 and the air ducts 504 and 604, respectively. As a result, when the air ducts 504 and 604 and the housings 502 and 602 are assembled together, the attachment positions between the air ducts 504 and 604 and the housings 502 and 602 can be determined by the attachment position limiting structures 501a and 601a, respectively. This prevents a problem with coupling of the fan connector 8a and the feeder connector 7b and a problem of the cables 8c being sandwiched between the air duct 504 or 604 and the housing 502 or 602.
It should be noted that the present invention is not limited to the above embodiments but includes various modifications. For example, the above embodiments have been described in detail to give an understandable description of the present invention and are not necessarily limited to an embodiment including all constituent elements described above. Some of constituent elements of one embodiment can be replaced with constituent elements of another embodiment, and a constituent element of another embodiment can be added to a constituent element of one embodiment. Furthermore, some of constituent elements of each embodiment can be deleted or added to or replaced with different constituent elements.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/016578 | 3/31/2022 | WO |
