Patent Application
20230354509
The present invention relates to an electronic control device.
In recent years, an electronic control device for a vehicle has been mechanically and electrically integrated in view of an increase in the number of electronic control devices mounted on a vehicle and a reduction in the length of a connection cable between a control device and a sensor and between a control device and an actuator. Specifically, integration of an engine control actuator and an electronic control device, integration of a transmission and an electronic control device, and the like are exemplified. Here, a surface temperature of an engine, a transmission, and the like is about 130° C. to 140° C., whereas a heat-resistant temperature of an electronic component used in an electronic control device is about 150° C.
When the electronic control device is operated in such a severe environment, heat of the engine, the transmission, and the like is transmitted via a case (housing) of the electronic control device to the electronic component on a substrate held by the case, and a temperature of the electronic component may exceed the heat-resistant temperature.
In the electronic control device disclosed in PTL 1, since the case for holding the substrate is made from metal (alloy), heat of the engine, the transmission, and the like is easily transmitted to the electronic component via the case (housing). In view of the above, in order to suppress a temperature rise of the electronic component due to heat of the engine, the transmission, and the like, it is conceivable to make a case (heat source side) of the electronic control device from resin.
However, in a case where static electricity is applied to a metallic case (on the atmosphere side) from a user's hand or the like, there arises a new problem that discharge is not performed to the ground (GND) via the case unlike a conventional structure. When static electricity is discharged from the metallic case to the electronic component, there is a concern that the electronic component may fail.
An object of the present invention is to provide an electronic control device capable of suppressing failure of an electronic component due to static electricity.
In order to achieve the above object, the present invention relates to an electronic control device that controls an actuator. The electronic control device includes a circuit board, an electronic component mounted on the circuit board, an insulating case that holds the circuit board, a first conductive cover that covers the insulating case, a second conductive cover that holds the insulating case and covers an opening portion of the actuator, and a conductive portion that makes the first conductive cover and the second conductive cover conductive.
According to the present invention, it is possible to suppress failure of an electronic component due to static electricity. An object, a configuration, and an advantageous effect other than those described above will be clarified in description of an embodiment described below.
Hereinafter, an embodiment of an electronic control device according to the present invention will be described in detail with reference to the accompanying drawings. The electronic control device controls, for example, an actuator (electromagnetic valve or the like) used for an engine, a transmission, and the like. Note that, in the drawings, the same reference numerals denote the same parts.
Lubricating oil for lubricating the mechanism unit is stored in the transmission case 131. The electronic control device (transmission control unit: TCU) B is attached to the transmission case 131. The transmission 103 and the electronic control device B are arranged in an engine room (not illustrated).
The metal cover 6 is held in the resin case 7 by fixing member 2 (for example, a screw) or the like. Further, a sealing member 10 such as an adhesive, for example, is arranged between the metal cover 6 and the resin case 7 and between the metal cover 6 or the resin case 7 and the connector 133 so that the inside of the electronic control device is hermetically sealed. A heat conductive material 11 such as grease, for example, is arranged between the electronic component 8 and the metal cover 6 or between the circuit board 5 and the metal cover 6, so that a temperature rise of the electronic component can be suppressed.
The resin case 7 is held in an actuator cover 12 made from metal by a fixing member 3 (for example, a screw) or the like. For example, rubber packing 20 or the like is arranged between the actuator cover 12 and the connector 133 and between the actuator cover 12 and the main body portion 134 of the transmission case to liquid-tightly seal the inside of the transmission. With such a configuration, received heat from the lubricating oil that may have a high temperature inside the transmission can be made less likely to be transmitted to the metal cover 6 by the resin case 7 having a low heat conductivity.
However, in a case where static electricity is applied to the metal cover 6 from a user's hand or the like, there arises a new problem that discharge is not performed to the ground (GND) through the case. In the present structure, electricity is conducted through a path from, for example, the metal cover 6 having a lowest electric resistance value to the heat conductive material 11, the electronic component 8, the circuit board 5, the connector 133, and the connector 132 (GND terminal) in this order, and thus there is a concern that the electronic component on the path may fail.
Next, a configuration of the electronic control device B according to a first embodiment of the present invention will be described. As illustrated in
That is, in the present embodiment, the electronic control device B that controls an actuator includes at least the circuit board 5, the electronic component 8 mounted on the circuit board 5, the resin case 7 (insulating case) that holds the circuit board 5, the metal cover 6 (first conductive cover) that covers the resin case 7, the actuator cover 12 (second conductive cover) that holds the resin case 7 and covers an opening portion of the actuator, and the conductive portion 13 that make the metal cover 6 (first conductive cover) and the actuator cover 12 (second conductive cover) conductive.
In this manner, a path having a small electric resistance value can be provided, and static electricity applied to the metal cover 6 flows through a path from the metal cover 6 to the actuator cover 12 and the GND in this order, and does not pass through the electronic component 8. Accordingly, damage to the electronic component 8 can be prevented. Further, by providing the conductive portion 13 at only one location, for example, it is possible to reduce received heat from the lubricating oil inside the transmission, and it is possible to realize a highly reliable electronic control device even in a structure that is mechanically and electrically integrated.
In the present embodiment, the electronic control device B includes the fixing member 2 (metal cover fixing screw) that fixes the metal cover 6 (first conductive cover) to the resin case 7 (insulating case) in a non-contact state with the actuator cover 12 (second conductive cover), and the fixing member 3 (resin case fixing screw) that fixes the resin case 7 to the actuator cover 12 in a non-contact state with the metal cover 6.
In this manner, the metal cover 6 (first conductive cover), the resin case 7 (insulating case), and the actuator cover 12 (second conductive cover) can be integrally fixed, and heat is less likely to be transmitted from the actuator cover 12 (second conductive cover) to the metal cover 6 via the fixing member 2 (metal cover fixing screw) or the fixing member 3 (resin case fixing screw). The fixing member 2 is not limited to a screw, and may be, for example, caulking, an adhesive, or a snap-fit. The fixing member 3 is not limited to a screw, and may be caulking, an adhesive, or a snap-fit.
Further, as described above, in the present embodiment, the conductive portion 13 make the metal cover 6 (first conductive cover) and the actuator cover 12 (second conductive cover) conductive only in one location. In this manner, heat is less likely to be transmitted from the actuator cover 12 (second conductive cover) to the metal cover 6.
Specifically, the metal cover 6 (first conductive cover) has a terminal-shaped portion 6T, and the actuator cover 12 (second conductive cover) has a pedestal 12P facing the terminal-shaped portion 6T. The conductive portion 13 includes the terminal-shaped portion 6T of the metal cover 6 and the pedestal 12P of the actuator cover 12.
Further, the electronic control device B also includes the fixing member 1 that fixes the circuit board 5 to the resin case 7 (insulating case). The fixing member 1 is, for example, a screw, caulking, an adhesive, or a snap-fit.
As described above, according to the present embodiment, it is possible to suppress failure of an electronic component due to static electricity.
As illustrated in
That is, the metal cover 6 (first conductive cover) and the actuator cover 12 (second conductive cover) are fixed by the conductive portion 13. In the present embodiment, the metal cover 6 (first conductive cover) and the actuator cover 12 (second conductive cover) are fixed at only one location by the conductive portion 13. In this manner, heat is less likely to be transmitted from the actuator cover 12 (second conductive cover) to the metal cover 6.
Specifically, the conductive portion 13 includes the fixing member 4 (conduction screw) that fixes the metal cover 6 (first conductive cover) to the actuator cover 12 (second conductive cover). The fixing member 4 is made from a conductive material such as conductive resin or conductive metal.
As illustrated in
That is, in the present embodiment, the fixing member 4 (conduction screw) fixes the metal cover 6 (first conductive cover) and the resin case 7 (insulating case) to the actuator cover 12 (second conductive cover) in such a manner that the metal cover 6 (first conductive cover) and the resin case 7 (insulating case) are overlapped with each other.
As illustrated in
R
T
=I/kA
Here, RT: electric heat resistance [k/W], I: thickness [m], k: heat conductivity [W/m/K], and A: heat transfer area [m2].
Therefore, it is possible to prevent damage to the electronic component due to static electricity and to make received heat from the lubricating oil inside the transmission further less likely to be transmitted to the electronic component 8.
However, with respect to the holding of the resin case 7 or the metal cover 6, a distance between fixing points can be shortened as a portion as close to the circuit board 5 as possible is fixed, and vibration resistance of the electronic control device B can be improved. In view of the above, for example, by making a minimum distance L1 between the fixing member 4 (conduction screw) and a circuit board end portion 5a longer than a minimum distance L2 between the fixing member 2 (metal cover fixing screw) and the circuit board end portion 5a or a minimum distance L3 between the fixing member 3 (resin case fixing screw) and the circuit board end portion 5a, a highly reliable electronic control device can be realized.
That is, in the present embodiment, the minimum distance L1 between the fixing member 4 (conduction screw) and the circuit board 5 is longer than the maximum distance L2 between the fixing member 2 (metal cover fixing screw) and the circuit board 5. Further, the minimum distance L1 between the fixing member 4 (conduction screw) and the circuit board 5 is longer than the maximum distance L3 between the fixing member 3 (resin case fixing screw) and the circuit board 5.
As illustrated in
However, uniformly reducing the thickness of the entire metal cover directly leads to reduction in mechanical strength of the metal cover 6. For this reason, vibration resistance and impact resistance of the electronic control device B are reduced. In particular, reducing the thickness of the fixing member 2 (metal cover fixing screw) holding the metal cover 6 is likely to lead to damage to the metal cover 6. For this reason, for example, by making a metal cover thickness t1 of the conductive portion thinner than a metal cover thickness t2 of the fixing member 2 (metal cover fixing screw), a highly reliable electronic control device can be realized.
That is, in the present embodiment, the thickness t1 of the metal cover 6 (first conductive cover) in the conductive portion 13 is thinner than the thickness t2 of the metal cover 6 (first conductive cover) around the fixing member 2.
In the electronic control devices up to the fifth embodiment, another problem other than electrostatic resistance and heat resistance occurs. As illustrated in
Therefore, in order to solve this, for example, as illustrated in
That is, in the present embodiment, the tapered portion 14a is formed in the metal cover 6 (first conductive cover) of the conductive portion 13. The tapered portion 14a includes an inclined surface inclined with respect to a surface of the metal cover 6 (first conductive cover) overlapping the resin case 7 (insulating case) or the actuator cover 12 (second conductive cover). The inclined surface includes two plane-symmetrical surfaces. In the present embodiment, the inclined surface is triangular.
In this manner, it is possible to extend a distance in a direction away from a side surface of the metal cover 6 (first conductive cover) while preventing the tapered portion 14a from interfering with the fixing member 4 (conduction screw). As a result, the metal cover 6 is more easily deformed, and stress generated in the metal cover 6 and the resin case 7 can be reduced.
As illustrated in
That is, in the present embodiment, the tapered portion 14b includes a curved surface. The tapered portion 14 has, for example, a semicircular shape. In other words, the tapered portion 14b has a half pipe shape. In this manner, the metal cover 6 is more easily deformed, and stress generated in the metal cover 6 and the resin case 7 can be reduced. Further, since a large space can be obtained between the fixing member 4 (conduction screw) and the tapered portion 14b, the fixing member 4 can be easily attached.
As illustrated in
In other words, the fixing member 4 is the caulking 15. In this manner, for example, the number of parts is reduced.
As illustrated in
As illustrated in
In other words, the fixing member 4 is the adhesive 16 having conductivity that makes the metal cover 6 (first conductive cover) and the actuator cover 12 (second conductive cover) conductive. In this manner, for example, it is not necessary to provide a hole for the fixing member 4 in the metal cover 6.
As illustrated in
It is generally known that a metal nut/collar is inserted into a screw fastening portion of the resin case 7 for the purpose of screw tap processing or resin creep prevention. In view of the above, as illustrated in
That is, in the present embodiment, the electronic control device B includes the integrated collar 19 (conductive collar) inserted into the resin case 7 (insulating case) in the conductive portion 13. The integrated collar 19 (conductive collar) is formed by integrating a conductive collar 17 corresponding to the fixing member 2 (metal cover fixing screw) and the conductive collar 18 corresponding to the fixing member 3 (resin case fixing screw). That is, the fixing member 4 (conduction screw) includes the fixing member 2 (metal cover fixing screw) and the fixing member 3 (resin case fixing screw).
In this manner, a discharge path of static electricity applied to the metal cover 6 can be secured, and stress generated in the metal cover 6 and the resin case 7 can be reduced.
Note that the present invention is not limited to the above embodiment and includes a variety of variations. For example, the above embodiment is described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to an embodiment that includes all the described configurations. Part of a configuration of a certain embodiment can be replaced with a configuration of another embodiment, and a configuration of a certain embodiment can be added to a configuration of another embodiment. Further, for part of a configuration of each embodiment, other configurations may be added, removed, or replaced with.
The embodiment of the present invention may have aspects described below.
(1). An electronic control device including a circuit board on which an electronic component and a connector are mounted, an insulating case that holds the circuit board, a first conductive cover that covers the insulating case, a heat conductive material that is arranged between the electronic component and the first conductive cover or between the circuit board and the first conductive cover, and a second conductive cover that holds the insulating case and liquid-tightly seal the inside of an actuator, the electronic control device further including a conductive portion that makes the first conductive cover and the second conductive cover conductive.
(2). In the electronic control device of (1), the first conductive cover is fixed to the insulating case in a non-contact state with the second conductive cover at a fixing portion 2, and the insulating case is fixed to the second conductive cover at a fixing portion 3 in a non-contact state with the first conductive cover.
(3). In the electronic control device according to (1) or (2), the conductive portion makes the first conductive cover and the second conductive cover conductive only at one location.
(4). In the electronic control device according to any of (1) to (3), the conductive portion fixes the first conductive cover and the second conductive cover.
(5). In the electronic control device according to any of (1) to (4), the conductive portion fixes the first conductive cover and the second conductive cover only at one location.
(6). In the electronic control device according to any of (1) to (5), a minimum distance L1 between the conductive portion and the circuit board is longer than a maximum distance L2 between the fixing member 2 and the circuit board.
(7). In the electronic control device according to any of (1) to (6), the minimum distance L1 between the conductive portion and the circuit board is longer than a maximum distance L3 between the fixing member 3 and the circuit board.
(8). In the electronic control device according to any of (1) to (7), a thickness of the first conductive cover is larger in the fixing portion 2 than in the conductive portion.
(9). In the electronic control device according to any of (1) to (8), in the first conductive cover, a tapered portion is formed at an inclination of approximately 45° with respect to the conduction surface on the conductive portion.
(9-1). In the electronic control device according to any of (1) to (8), in the first conductive cover, a tapered portion is formed in a substantially semicircular shape on the conductive portion.
(10). In the electronic control device according to any of (1) to (9-1), the conductive portion is caulking.
(11). In the electronic control device of (10), the conductive portion is caulking, and fixes the first conductive cover and the second conductive cover in a manner that the insulating case is sandwiched between them.
(12). In the electronic control device according to any of (1) to (9-1), the conductive portion fixes the first conductive cover and the second conductive cover with a fixing member 4.
(13). In the electronic control device according to any of (1) to (9-1), the conductive portion fixes the first conductive cover and the second conductive cover with a fixing member 4.
(14). In the electronic control device of (13), the fixing member 4 fixes the first conductive cover and the second conductive cover in a manner that the insulating case is sandwiched between them.
(15). In the electronic control device according to any of (13) and (14), the fixing member 4 is a screw.
(16). In the electronic control device according to any of (13) and (14), the fixing member 4 is an adhesive having conductivity that makes the first conductive cover and the second conductive cover conductive.
(17). In the electronic control device according to any of (1) to (16), the circuit board is fixed to the insulating case by caulking.
(18). In the electronic control device according to any of (1) to (16), the circuit board is fixed to the insulating case by a snap-fit.
(19). In the electronic control device according to any of (1) to (16), the circuit board is fixed to the insulating case with a fixing member 1.
(20). In the electronic control device according to (19), the fixing member 1 is a screw.
(21). In the electronic control device according to (19), the fixing member 1 is an adhesive.
(22). In the electronic control device according to any of (1) to (21), the fixing portion 2 is caulking.
(23). In the electronic control device according to any of (1) to (21), the fixing portion 2 is a snap-fit.
(24). In the electronic control device according to any of (1) to (21), the fixing portion 2 is fixed with the fixing member 2.
(25). In the electronic control device according to (24), the fixing member 2 is a screw.
(26). In the electronic control device according to (24), the fixing member 2 is an adhesive.
(27). In the electronic control device according to any of (1) to (26), the fixing portion 3 is caulking.
(28). In the electronic control device according to any of (1) to (26), the fixing portion 3 is a snap-fit.
(29). In the electronic control device according to any of (1) to (26), the fixing portion 3 is fixed with the fixing member 3.
(30). In the electronic control device according to (29), the fixing member 3 is a screw.
(31). In the electronic control device according to (29), the fixing member 3 is an adhesive.
(32). In the electronic control device according to any of (1) to (31), the fixing member 2 and the fixing member 4 are the same.
(33). In the electronic control device according to any of (1) to (32), the fixing member 3 and the fixing member 4 are the same.
(34). In the electronic control device according to any of (1) to (33), in the insulating case, a first conductive collar is inserted into the conductive portion.
(35). In the electronic control device according to (34), the first conductive collar is integral with a second conductive collar inserted in the fixing portion 2 in the insulating case.
(36). In the electronic control device according to (34), the first conductive collar is integral with a third conductive collar inserted in the fixing portion 3 in the insulating case.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-033927 | Feb 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/049084 | 12/28/2020 | WO |
