JP2005150633A - Electronic controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic controller wherein positioning of a substrate, guidance upon assembly, supporting, and temporary fixing during the manufacturing process are carried out with one resin molding member. <P>SOLUTION: This electronic controller comprises a substrate unit 100 formed by attaching a metal substrate 49 and a base substrate 48 together so that they overlap one another. The base substrate 48 comprises: a supporting part for maintaining an aligned state of the base substrate 48 and the metal substrate 49 achieved by an alignment part upon the assembly of them; and an assembling engagement part 46 for making the metal substrate 49 engage the base substrate 48 and maintaining the engaged state, which are formed integrally with the resin substrate. The metal substrate 49 comprises a fixed hole formed therein into which the alignment part is to be fit, and the alignment part is inserted into the fixed hole, and the assembling engagement part 46 engages in the peripheral direction of the metal substrate 49 via an elastically deformed state. Thus, the base substrate 48 and the metal substrate 49 coalesce to form the substrate unit 100. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic control device.

  In particular, electronic control devices used for vehicles are required to be downsized due to space limitations. However, since an electric current of several tens of A flows depending on the actuator, it is practical from the viewpoint of heat generation and the space on the board to configure the actuator energization line etc. by the wiring pattern on the normal printed board with a limit on the thickness. It was impossible. For this reason, the width and thickness of the conductor are much larger than the wiring pattern on the printed circuit board, and a bus bar (conductive plate) capable of flowing a large current is attached on the printed circuit board, so that the energization line and the like are It is configured.

  Conventionally, the components are arranged in a plane on a single circuit board, so that the size in the surface direction of the circuit board is particularly large.

  In addition, when the electronic control device is disposed in the vehicle interior, high waterproofness is not required. However, in the engine room (especially in the lower part of the engine room), water is naturally assumed, so It is required to be waterproof to some extent. In particular, in recent years when the demand for vehicle safety is increasing, high reliability is being demanded of each device even in a harsh environment such as when the vehicle is submerged, even if it is an electronic control device arranged in a vehicle interior, There is an increasing tendency to require high airtightness and dust-proof measures.

  To solve the above problems, the drive circuit is mounted on a metal substrate, the control circuit is mounted on an insulating substrate, and a large current circuit component such as an electrolytic capacitor is mounted on a base substrate in which metal circuit conductor components are integrated by insert molding. However, an electronic control device for a vehicle has been devised that has a structure in which a metal substrate and an insulating substrate are attached to a base substrate in a stacked state (see Patent Document 1).

JP 2001-196770 A

  In the example of Patent Document 1, the metal substrate and the insulating substrate are not fixed to the base substrate. Therefore, in an intermediate assembly (subassembly) in which the metal substrate and the insulating substrate are assembled to the base substrate, when the subassembly is turned upside down, the metal substrate and the insulating substrate fall off the base substrate and fall. End up. In this sub-assembly state, a solder layer (so-called flow process) is performed in a soldering process (so-called flow process) through a solder bath containing liquid solder melted by heating. There is a possibility that the board or component will be lifted from the base board due to the buoyancy of the liquid, and may not be soldered correctly.

  Accordingly, an object of the present invention is to solve the above-mentioned technical problems, and an electronic control device capable of performing positioning of a substrate, guidance at the time of assembly, support, and temporary fixing during a manufacturing process with a single resin molded member Is to provide.

Means for Solving the Problems and Effects of the Invention

The present invention provides an electronic control device for solving the above problems. That is, according to claim 1, the electronic control device of the present invention is
A metal substrate on which a base material is made of a metal covered with an insulator and on which a predetermined circuit component is mounted; a predetermined circuit component is mounted; and a metal circuit conductor constituent member is made of a resin base material by insert molding. An electronic control device comprising an integrated base substrate and including a metal substrate and a substrate unit formed by being attached so as to overlap the base substrate,
The base substrate has a support portion for aligning and maintaining the position at the alignment portion during assembly with the metal substrate, and an assembly engagement portion for engaging the metal substrate and maintaining the engagement state. Is formed integrally with a resin base material,
The metal substrate is formed with a fixing hole into which the alignment portion is fitted,
The alignment portion is inserted into the fixing hole, and the assembly engagement portion engages in the outer peripheral direction of the metal substrate through an elastically deformed state, whereby the base substrate and the metal substrate are combined to form a substrate unit. It is comprised as an electronic control apparatus characterized by this.

  With this configuration, the member for assembling the metal substrate to the base substrate is formed integrally with the resin base material constituting the base substrate, so it is only necessary to change the base material formation process. There is no need to prepare other members for assembly. Therefore, the manufacturing cost is not increased by this configuration.

  In addition, since the metal substrate is fixed to the base substrate by this configuration, even if the substrate unit (so-called subassembly state) is turned upside down, one of the substrates does not come off and fall, It is also possible to work. It is also possible to perform soldering by a flow process in the state of the board unit. That is, since the flow process automatically passes the board unit through the solder layer by the conveyor, the cost required for soldering is reduced as compared with the process of performing soldering manually.

  Further, according to the present configuration, the unit is not separated even when transported or transported in the state of this subassembly. Therefore, the process after the metal substrate is assembled to the base substrate can be performed at a remote location.

  According to a second aspect of the present invention, in the electronic control device of the present invention, the base substrate in the substrate unit has a structure in which a screw guide portion for attaching the substrate unit to the housing of the electronic control device is formed inside the support portion. Take. With this configuration, since the support portion and the screw guide portion are integrally formed, the area of the substrate can be reduced as compared with the case where they are formed separately. Moreover, since the shape of the resin-made base material which comprises a base board | substrate does not become complicated, the cost required for base-material formation can also be reduced.

According to a third aspect of the present invention, the electronic control device of the present invention uses a screw guide portion, fixes the substrate unit to a heat sink that forms the bottom of the housing, and the heat sink radiates heat generated by the metal substrate. .

  With this configuration, it is possible to ensure high heat dissipation of heat generated in the metal substrate while avoiding an increase in the number of components. This is because the heat sink constitutes the bottom surface, and the outer surface is exposed to the outside air, so that high heat dissipation is obtained. Also, for example, the metal substrate itself can be configured to function as a heat sink, but in that case, the metal substrate itself needs to have a size and shape having a certain heat radiation area, and is attached to the base substrate. In addition, the ease of electrical connection work may not necessarily be ensured. However, such a problem does not occur when the heat sink and the metal substrate are separated as described above. Further, when adjusting the heat dissipation effect, it is only necessary to change the shape of the heat sink, so that the metal substrate and other members constituting the electronic control device are not affected.

  According to a fourth aspect of the present invention, in the electronic control device of the present invention, the waterproof O-ring is sandwiched and fixed between the housing and the heat sink, and the O-ring is compressed in the screwing direction so that the O-ring is waterproof. Take a composition to play a role. With this configuration, it is possible to prevent liquid such as water from entering the electronic control device.

  According to the fifth aspect of the present invention, the electronic control device of the present invention has a configuration in which the heat sink includes a storage hole for storing the tip of the assembly engagement portion. With this configuration, even when the tip of the assembly engaging portion protrudes from the bottom surface of the metal substrate, an extra gap is formed when the substrate unit (metal substrate) is fixed to the heat sink, or the metal substrate is It is no longer possible to dissipate heat generated in the metal substrate without being in close contact with the substrate. Further, when the substrate unit (metal substrate) is fixed to the heat sink, the tip of the assembly engagement portion is not damaged.

  According to the sixth aspect of the present invention, the electronic control device of the present invention has a configuration in which the screw guide portion is extended in a direction opposite to the forming direction of the support portion. With this configuration, the screw guide portion is also formed above the base substrate, and the height of the screw guide portion is equal to or higher than that of the highest mounted component, so that the substrate unit can be attached to the heat sink (housing). When fixing to the body), the attachment screw can be surely inserted into the screw guide portion, and the screw is not accidentally dropped onto the substrate unit.

  According to the seventh aspect of the present invention, in the electronic control device of the present invention, the support portion is provided on one set of diagonals of the base substrate, and the assembly engagement portion is on the other set of diagonals of the base substrate. The structure provided in is taken. With this configuration, the metal substrate can be reliably assembled to the base substrate with a small number of parts. For this reason, manufacture at low cost is possible.

  In order to realize an electronic control device in which the metal substrate is securely assembled to the base substrate, the support portion is provided on one set of diagonals of the base substrate, and the assembly engagement portion is another set of the base substrate. It was realized as a configuration provided on the diagonal of.

  Hereinafter, an embodiment in which an electronic control device of the present invention is applied to a four-wheel drive vehicle will be described with reference to the drawings. The application range of the electronic control device of the present invention is not limited to a four-wheel drive vehicle.

  FIG. 1 is a schematic configuration diagram of a four-wheel drive vehicle in the present embodiment. In FIG. 1, a four-wheel drive vehicle 1 includes an engine 2 and a transaxle 3 which are internal combustion engines. The transaxle 3 includes a transmission 3a, a front differential 3b, a transfer 3c, and the like. The front differential 3b is connected to a pair of left and right front axles 4a and 4b, and front wheels 5a and 5b are connected to the pair of front axles 4a and 4b, respectively. Accordingly, the driving force of the engine 2 is transmitted to the front wheels 5a and 5b via the transmission 3a, the front differential 3b and the pair of left and right front axles 4a and 4b, respectively.

  The transfer 3 c is connected to a propeller shaft 6, and the propeller shaft 6 is drivingly connected to a driving force transmission device 7. Therefore, the driving force of the engine 2 is transmitted to the driving force transmission device 7 via the transmission 3a, the transfer 3c, and the propeller shaft 6. The driving force transmission device 7 is connected to a rear differential 9 via a drive pinion shaft 8, and the rear differential 9 is connected to a pair of left and right rear axles 10a and 10b. Rear wheels 11a and 11b are connected to the rear axles 10a and 10b, respectively.

  The driving force transmission device 7 includes a wet-type multi-plate electromagnetic clutch mechanism, and the electromagnetic clutch mechanism has a plurality of clutch plates that can be connected to and separated from the electromagnetic coil. Then, the clutch plates are frictionally engaged with each other in accordance with a current value supplied based on a control signal (command value) from the driving force distribution electronic control device 21 to be described later on the electromagnetic coil, and the propeller is attached to the drive pinion shaft 8. Torque is transmitted to the driving force of the shaft 6.

  Reference numeral 21 denotes a driving force distribution electronic control device (hereinafter simply referred to as an ECU) for driving and controlling the driving force transmission device 7, and the ECU 21 corresponds to a throttle opening sensor 32 according to the operation mode set in the mode selection switch 31. , Based on the throttle opening, differential rotational speed, vehicle speed, and oil temperature calculated from the wheel speed sensors 33a to 33d for detecting the rotation of the wheels of the front wheels 5a and 5b and the rear wheels 11a and 11b and the oil temperature sensor 34. Then, the driving force transmission device 7 is controlled.

  FIG. 2 shows the appearance of the ECU 21. FIG. 2A is a view as seen from above, and FIG. 2B is a view as seen from the side where the connectors 43 and 44 are located. As shown in FIG. 2, brackets 41 a and 41 b are integrally formed on the resin housing 51 of the ECU 21, and connectors 43 and 44 protrude from the side surfaces thereof. Since the ECU 21 is attached to the outside of the vehicle (for example, between the bottom surface of the vehicle and the propeller shaft 6) where water droplets are likely to be applied, waterproofing is required. In addition, components that generate heat are mounted to handle large currents.

  Next, assembly of the base substrate 48 and the metal substrate 49 stored in the ECU 21 will be described with reference to FIGS. 3 is a perspective view showing the base substrate 48, FIG. 4 is a perspective view showing the configuration at the time of assembly, FIG. 5 is a diagram showing the assembly configuration of the driving force distribution ECU 21, and FIG. 6 is an assembly part of FIG. FIG.

  FIG. 3 shows an outline of the configuration of the base substrate 48. In the base substrate 48, a metal circuit conductor constituent member (bus bar) is integrated with a resin base material by insert molding, and components or circuits through which a large current flows such as a power supply circuit and a large current circuit component are mounted. FIG. 8 is a view of the base substrate 48 as viewed obliquely from above. A column 47 (support portion in the present invention) is provided on one set of diagonals of the base substrate 48, and on another set of diagonals. An assembly engagement portion 46 is provided. FIG. 4 shows a state in which the metal substrate 49 is assembled to the base substrate 48.

  As shown in FIGS. 5 and 6, the column 47 is formed with a column lower portion 47b in the direction facing the metal substrate 49 of the column 47 (that is, the lower portion of the base substrate 48), and at the tip thereof than the column lower portion 47b. An alignment portion 47a having a small outer diameter is formed in a concentric stepped shape, and a column end surface portion 47f is formed on the periphery of the alignment portion 47a. On the other hand, a guide guide portion 47e for a screw that fixes the substrate unit 100 to the heat sink 53 that forms the bottom of the housing of the ECU 21 is formed in a direction not facing the metal substrate 49 of the support column 47 (that is, the upper portion of the base substrate 48). Then, a screw guide portion 47d is formed so as to penetrate the guide guide portion 47e, the base substrate 48, and the column lower portion 47b.

  3, 4, and 8, for convenience of explanation, a portion configured on the upper portion of the base substrate 48 in the column 47 is omitted. Also, in the base substrate 48 and the metal substrate 49 of FIGS. 5 and 6, a part of the portion that does not interfere with the description of the present embodiment is omitted.

  Further, the assembly engaging portion 46 is formed so as to protrude in the direction of the metal substrate 49, has a substantially L shape, can be elastically deformed in the A direction, and has an inclined surface 46b formed at the tip portion 46a thereof. It is designed to engage smoothly and reliably.

  The metal substrate 49 is formed with a fixing hole 49a for receiving the alignment portion 47a. Since the diameter of the fixing hole 49a is substantially the same as the outer shape of the alignment portion 47a, the column end surface portion 47f serves as a stopper when the alignment portion 47a is inserted into the fixing hole 49a. The metal substrate 49 is mounted with components or circuits that easily generate heat, such as a drive circuit for driving an actuator such as an electromagnetic coil of the driving force transmission device 7.

  Next, details of assembly of the metal substrate 49 to the base substrate 48 will be described with reference to FIGS. While the alignment portion 47a is inserted into the fixing hole 49a, the distal end portion 46a of the assembly engagement portion 46 is elastically deformed in the outer peripheral direction of the metal substrate 49, and the alignment portion 47a is fitted into the fixing hole 49a for positioning. At the same time, the tip end portion 46a of the assembly engaging portion 46 returns to the original shape from the elastically deformed state and is engaged with the metal substrate 49, whereby the substrate unit 100 is formed. At this time, the column end surface portion 47f is in contact with the metal substrate 49.

  Thereafter, the bus bar terminal group 57 mounted on the base substrate 48 is soldered to the metal substrate 49. At this time, since the base substrate 48 is engaged with the metal substrate 49 by the assembly engaging portion 46, even if the solder layer is passed through the flow process, both the substrates are not separated. It is possible to do.

  Next, a method for attaching the board unit 100 to the housing 51 of the ECU 21 will be described. The board unit 100 inserts the screw 45 into the screw guide 47d, and fixes the screw to the heat sink 53 by screwing in the screw hole 53c. At this time, the presence of the guide guide portion 47e and the screw guide portion 47d allows the screw 45 to be reliably inserted into the screw hole 53c, and the screwing operation can be easily performed.

  When the front end portion 46a of the assembly engaging portion 46 has a shape protruding from the bottom surface of the metal substrate 49, avoid interference with the front end portion 46a on the surface facing the front end portion 46a of the heat sink 53 as shown in FIG. A method of providing a storage hole 53b for this purpose may be employed.

  After the board unit 100 is attached to the heat sink 53, the board 54 is inserted into the ECU 21 by fixing the heat sink 53 to the housing 51 by inserting the screw 54 into the screw guide 53a and screwing it in the screw hole 55. The

  A housing groove 56 for housing the O-ring 52 is formed at a position facing the O-ring 52 at the lower side wall of the housing 51 (see FIG. 6). The depth of the storage groove is smaller than the outer shape of the O-ring 52, and by attaching the heat sink 53 to the housing 51, the O-ring 52 is compressed and deformed and is brought into close contact with the storage groove 56 and the heat sink 53 with an appropriate pressure. Function can be expected. As a result, even if a liquid such as water enters from between the housing 51 and the heat sink 53, the O-ring 52 can reliably prevent the intrusion into the ECU 21.

  By using a member having good thermal conductivity for the O-ring 52, heat is conducted from the metal substrate 49 on which a heat-generating component is mounted to the heat sink 53, and heat is radiated from the heat sink 53 to the outside. It becomes possible to enhance the cooling effect of the mounted components.

  In this embodiment, as shown in FIG. 8, the support 47 is provided on one set of diagonals of the base substrate 48, and the assembly engaging portion 46 is provided on the other set of diagonals. However, a configuration may be adopted in which the supports 47 are provided on the two diagonals of the base substrate 48 and the assembly engaging portions 46 are provided at predetermined positions on each side of the base substrate 48. As described above, there are no particular restrictions on the number or installation positions of the support columns 47 and the assembly engaging portions 46. Further, FIG. 7 shows a part of the base substrate 48 as viewed obliquely from below, but a configuration in which the support 47 and the assembly engaging portion 46 are integrated as described above may be adopted.

  Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited to these embodiments, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed schematic structure of the four-wheel drive vehicle which is one Example of this invention. The external view of ECU for driving force distribution. The perspective view which showed the base substrate before board | substrate unit assembly | attachment. The perspective view which showed the structure after board | substrate unit assembly | attachment. The figure which showed the assembly | attachment structure of ECU for driving force distribution. The figure which showed the detail of the assembly | attachment part in FIG. The figure for demonstrating the modification of this invention. The perspective view for demonstrating the shape of a base substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Four-wheel drive vehicle 7 Driving force transmission device 21 Driving force distribution electronic control unit (ECU)
46 Assembly engagement portion 47 Post 47a Positioning portion 47b Lower column 47d Screw guide 47e Guide guide 47f Post end surface 48 Base substrate 49 Metal substrate 49a Fixing hole 51 Housing 52 O-ring 53 Heat sink 100 Substrate unit

Claims (7)

A metal substrate on which a base material is made of a metal covered with an insulator and on which a predetermined circuit component is mounted; a predetermined circuit component is mounted; and a metal circuit conductor constituent member is made of a resin base material by insert molding. An electronic control device comprising an integrated base substrate and comprising a substrate unit formed by being attached to overlap the metal substrate and the base substrate,
An assembly for engaging the metal substrate and maintaining the engagement state by engaging the base substrate with the base substrate and aligning the position with the alignment portion when the assembly is performed with the metal substrate. The engaging portion is formed integrally with the resin base material,
The metal substrate is formed with a fixing hole into which the alignment portion is fitted,
The base portion and the metal substrate are merged when the alignment portion is inserted into the fixing hole and the assembly engagement portion engages in an outer peripheral direction of the metal substrate through an elastic deformation state. An electronic control device, wherein the substrate unit is formed.   The electronic control device according to claim 1, wherein a screw guide portion for attaching the substrate unit to a housing of the electronic control device is formed inside the support portion.   The electronic control device according to claim 2, wherein the screw guide portion is used to fix the substrate unit to a heat sink that forms a bottom portion of the housing, and the heat sink radiates heat generated in the metal substrate.   The electron according to claim 3, wherein the O-ring plays a waterproof role by fixing a waterproof O-ring between the housing and the heat sink and compressing the O-ring in a screwing direction. Control device.   The electronic control device according to claim 3, wherein the heat sink is provided with a storage hole for storing a front end portion of the assembly engagement portion.   The electronic control device according to claim 1, wherein the screw guide portion is extended in a direction opposite to a direction in which the support portion is formed. The said support part is provided on one set of diagonals of the said base substrate, and the said assembly engagement part is provided on another set of diagonals of the said base substrate. The electronic control device according to claim 1.