JP2010215127A - On-vehicle electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle electronic device preventing breakage of a circuit board provided on the electronic device mounted on a vehicle upon collision of the vehicle. <P>SOLUTION: The on-vehicle electronic device 1 includes a circuit board 4 for mounting electronic components, a case 2 with a lid 3 housing and holding the circuit board 4, and a plurality of brackets 6, 7 for attaching the on-vehicle electronic device 1 to the vehicle. The plurality of brackets 6, 7 include an integral bracket 6 formed integrally with the lid 3, and an independent bracket 7 formed as a separate component independent from the case 2 and the lid 3 and connected to the case 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device mounted on a vehicle, and more particularly to an in-vehicle electronic device that can protect a circuit board or the like that deploys an airbag in the event of a collision.

  In recent years, due to the heightened awareness of automobile safety, airbags have become standard equipment on almost all vehicles in the driver's and passenger's seats along with improvements in collision safety technology and the establishment of seat belts. In order to deploy the airbag at the time of a vehicle collision, the vehicle is based on a detection signal output from an electronic acceleration sensor (hereinafter referred to as “G sensor”) that detects an impact caused by the collision, a G sensor, and the like. A collision detection electronic device including a circuit board on which electronic components such as a microcomputer (hereinafter, may be abbreviated as “microcomputer” in some cases) for performing a collision determination is mounted.

  FIG. 5 is a perspective view showing a configuration of a conventional collision detection electronic device 100. FIG. 5A is a perspective view of the collision detection electronic device 100 as viewed from above, and FIG. The perspective view which looked at the electronic device 100 for a detection from the downward direction of Fig.5 (a) is shown. The collision detection electronic device 100 includes a circuit board (not shown) on which a G sensor and a microcomputer are mounted, a synthetic resin case 101 in which the circuit board is accommodated, and a circuit board accommodated in the case 101. A substantially plate-like metal lid 102 that covers the circuit board and a connector (not shown) that is electrically connected to the circuit board and electrically connected to an external connection cable. The circuit board is held and fixed in a state of being sandwiched between a boss provided on the case 101 and the lid 102 using a fastening screw 104 that is a fastener. The synthetic resin case 101 and the metal lid 102 constitute a casing.

  The metal lid 102 includes a plurality of brackets 103 for fixing the collision detection electronic device 100 to the vehicle body of the vehicle, and the plurality of brackets 103 are formed integrally with the lid 102. The electronic device 100 for collision detection is fixed to the vehicle body of the vehicle, specifically to the frame of the vehicle floor, by fastening bolts or the like via the plurality of brackets 103. At this time, the metal lid 102 faces the frame of the vehicle.

  The collision detection electronic device 100 is required to satisfy at least the following two requirements in order to realize a special function of detecting a vehicle collision.

  The first is to reliably transmit the impact caused by the collision of the vehicle from the vehicle body to the G sensor mounted on the circuit board. That is, the collision detection electronic device 100 is configured to reliably transmit the impact at the time of the vehicle collision to the G sensor mounted on the circuit board housed in the case 101 without any attenuation. It is demanded.

  Secondly, the circuit board housed in the case 101 is protected against vehicle body deformation caused by a vehicle collision. In other words, the collision detection electronic device 100 needs to continue to function normally at least until a collision is determined by the microcomputer based on the detection signal from the G sensor and an ignition current for causing the airbag to deploy is supplied. is there. However, recently, when a vehicle collision occurs, it has been required to be able to verify later whether or not the collision detection electronic device 100 has been appropriately operated. Therefore, even if the collision detection electronic device 100 has a vehicle collision, the circuit board is destroyed even if the vehicle is deformed due to the collision of the vehicle in order to verify later that the circuit board has worked normally. There is a need for a configuration that can protect against this.

  Since the conventional collision detection electronic device 100 shown in FIG. 5 is firmly fixed to the vehicle body of the vehicle via three brackets 103 provided on the lid 102, the first requirement is as follows. Is satisfied. However, it was not sufficient for the second requirement. Specifically, when the case 101 formed of a lightweight and inexpensive synthetic resin is destroyed by a vehicle body deformation caused by a vehicle collision, the circuit board accommodated in the case 101 is exposed to the outside. Therefore, there is a problem that the circuit board itself is thermally destroyed due to a short circuit caused by adhesion or contact of the scattered metal powder to the exposed circuit board when the vehicle is damaged.

  Further, since the case 101 is made of synthetic resin, the case 101 is greatly distorted with respect to the same impact load as compared with a metal case. It will be larger than Therefore, the case 101 made of synthetic resin has a problem that the circuit board is greatly distorted. And there exists a problem that the electronic component mounted in a circuit board will be destroyed by such distortion of a circuit board.

  The objective of this invention is providing the vehicle-mounted electronic device which can prevent that the circuit board with which the vehicle-mounted electronic device mounted in a vehicle is destroyed with respect to the collision of a vehicle.

The present invention (1) includes a circuit board on which electronic components are mounted,
A housing that houses and holds the circuit board;
In the in-vehicle electronic device having a plurality of brackets for attaching the housing to the vehicle,
The plurality of brackets are
An integrated bracket integrally formed with the housing;
An in-vehicle electronic device comprising: an independent bracket formed as a separate component independent of the housing and coupled to the housing.

  According to the present invention (1), since the housing for accommodating and holding the circuit board is attached to the vehicle body via the integrated bracket and the independent bracket, the vehicle body deformation due to the collision of the vehicle. On the other hand, the integrated bracket, the housing in which the integrated bracket is integrally molded, and the circuit board housed and held inside the housing move together, whereas the independent bracket is Compared to the integrated bracket, it is connected to the part that moves integrally with the housing, and is therefore attached to the vehicle body in a state of being structurally divided. The part that moves as a unit behaves differently in terms of mechanical properties such as stress and strain.

  In this way, the structure system connected to the integrated bracket and the structure system connected to the independent bracket are configured to behave differently with respect to the external force due to the deformation of the vehicle body. It is possible to generate a region that is easily broken between the adjacent portions and to facilitate deformation or separation.

  Therefore, the distortion generated in the casing due to the deformation of the vehicle body can be reduced as much as possible, the load on the circuit board accommodated in the casing is reduced, and the distortion generated in the circuit board can be reduced. Further, it is possible to prevent the casing from being broken and the circuit board from being exposed to the outside. Therefore, even if the vehicle body is deformed due to a vehicle collision, it is possible to prevent the metal powder from directly adhering to or contacting the circuit board and destroying the circuit board due to heat generation and distortion due to a short circuit. Can be reliably protected.

It is a disassembled perspective view which shows the structure of the vehicle-mounted electronic device 1 of embodiment of this invention. 2 is a perspective view showing a configuration of the in-vehicle electronic device 1 according to the embodiment of the present invention. FIG. 2A shows a perspective view of the in-vehicle electronic device 1 as viewed from below in FIG. 1 shows a perspective view of the in-vehicle electronic device 1 as viewed from above in FIG. It is a perspective view which expands and shows the connection structure of the stand-alone bracket 7 and case 2 in the vehicle-mounted electronic device 1 of embodiment of this invention. It is a perspective view which expands and shows the connection structure of the independent bracket 27 and the case 2 in the vehicle-mounted electronic device 21 of other embodiment of this invention. FIG. 5A is a perspective view showing a configuration of a conventional collision detection electronic device 100, FIG. 5A is a perspective view of the collision detection electronic device 100 viewed from above, and FIG. 5B is a collision detection electronic device. The perspective view which saw 100 from the lower part of Drawing 5 (a) is shown.

  FIG. 1 is an exploded perspective view showing a configuration of an in-vehicle electronic device 1 according to an embodiment of the present invention. 2 is a perspective view showing a configuration of the in-vehicle electronic device 1 according to the embodiment of the present invention. FIG. 2A is a perspective view of the in-vehicle electronic device 1 as viewed from below in FIG. 2 (b) is a perspective view of the vehicle-mounted electronic device 1 as viewed from above in FIG.

  The in-vehicle electronic device 1 according to the present embodiment is an airbag control ECU (Electronic Control Unit) for detecting an impact caused by a vehicle collision and controlling the airbag. It is used by being attached to the body frame. This in-vehicle electronic device 1 is mounted on a vehicle exclusively for an airbag system, and includes a case 2, a lid 3, a circuit board 4, a connector 5, an integrated bracket 6, and an independent bracket 7. . The case 2 and the lid 3 constitute a casing, and are configured so that the circuit board 4 can be accommodated and held therein.

  The circuit board 4 includes an electronic acceleration sensor (hereinafter referred to as “G sensor”) for detecting an impact caused by a vehicle collision, and a microcomputer (hereinafter referred to as a collision determination) based on a detection signal output from the G sensor. Electronic components such as “microcomputer” may be abbreviated). The microcomputer calculates acceleration data output from the G sensor, and compares the calculated value with a threshold value that serves as a collision determination criterion to determine whether or not the airbag should be deployed. If the microcomputer determines that the airbag should be deployed, the microcomputer turns on the ignition circuit and causes the airbag to deploy by flowing an ignition current through the ignition device.

  The case 2 has a rectangular plate-like bottom portion 2a and three side wall portions 2b, 2c, 2d rising at right angles from the peripheral edges of the bottom portion 2a, and an area surrounded by the three side wall portions 2b, 2c, 2d. The circuit board 4 is accommodated in the housing. On the inner side of the case 2, a connector mounting portion for mounting the connector 5 on the remaining one side (hereinafter referred to as “opening side”) with respect to the three sides blocked by the side wall portions 2 b, 2 c, 2 d 2e is formed. The connector mounting portion 2e is formed so that the connector 5 can be fitted and mounted on the opening side of each of the two opposing side wall portions 2b and 2c and the bottom portion 2a.

  In addition, a plurality of screw holes (in the present embodiment) are formed inside the case 2 to which the fastening screws 8 as fasteners are screwed in order to hold the circuit board 4 inside the case 2. Four bosses are erected from the bottom 2a along the side walls 2b, 2c and 2d, respectively, and one of the bosses is disposed in the vicinity of a bracket connecting portion 9 described later.

  Further, one of the opposing side wall portions 2b and 2c in the case 2 is formed with a bracket connecting portion 9 to which a later-described independent bracket 7 is connected on the opening side. The bracket connecting portion 9 is provided on the opening side end surface of the side wall portion 2b. The bracket connecting portion 9 will be described in detail later.

In the present embodiment, the case 2 is, for example, ABS (Acrylonitrile Butadiene Styrene).
) Since it is made of a hard resin such as a resin, it can be realized at a light weight and at a low price. However, the case 2 is not limited to the hard resin, and may be formed by aluminum die casting, for example.

  The circuit board 4 has a rectangular plate shape and is formed so as to have an outer dimension that can be accommodated in a region formed inside the case 2. On the surface on one side in the thickness direction, an electronic device such as the G sensor and the microcomputer described above is formed. The component is mounted. The circuit board 4 is formed with insertion holes through which the fastening screws 8 are inserted in the thickness direction at positions corresponding to the respective screw holes in the four bosses provided in the case 2. Yes. For example, a glass epoxy board may be used as the circuit board 4 as a wiring board on which the G sensor and the microcomputer are mounted on one surface side. Hereinafter, in the circuit board 4, one surface on which the electronic component is mounted may be referred to as a “board upper surface”.

  The connector 5 is electrically connected to the circuit board and electrically connected to an external connection cable, such as transmitting an ignition current flowing from the circuit board 4 to an ignition device (squib) for deploying the airbag. And is joined to the circuit board 4 by a method such as soldering.

  The lid 3 is formed of a substantially plate-like metal, and extends from a cover 3a formed to have an outer dimension that can be accommodated in a region formed inside the case 2, and a peripheral edge of the cover 3a. Bracket portion 6. In the cover portion 3a, insertion holes through which the fastening screws 8 are inserted are formed so as to penetrate in the thickness direction at positions corresponding to the screw holes in the four bosses provided in the case 2. .

  The circuit board 4 to which the connector 5 is bonded is accommodated in the case 2 so that the upper surface of the circuit board faces the bottom 2a of the case 2 and the connector 5 is fitted to the connector mounting portion 2e, and is further on the side opposite to the upper surface of the board In a state where the lower surface of the substrate is covered by the cover 3a of the lid 3, the fastening screw 8 is inserted into the cover 3a and the insertion hole of the circuit board 4 and tightened, whereby the housing formed by the case 2 and the lid 3 is accommodated. It is held fixed in the space.

  Further, two bracket portions 6 corresponding to the integrated bracket are provided in the present embodiment, and the bolt insertion hole 6a into which a bolt for attaching the in-vehicle electronic device 1 to the vehicle body frame is inserted is thick. Each is formed penetrating in the direction. Each bracket portion 6 is provided so as to extend in the same direction from the peripheral edge portion of the cover portion 3a, and the lid 3 extends from the side wall portion 2d of the case 2 opposite to the side where the connector mounting portion 2e is provided to the bracket portion. It is attached to the case 2 so that 6 protrudes.

  The independent bracket 7 is formed of a substantially plate-like metal as a separate component independent of the case 2 and the lid 3, and is attached to the connecting portion 7 a connected to the case 2 and the vehicle body frame. A bolt insertion hole 7c through which a bolt is inserted has a fixing portion 7b formed so as to penetrate in the thickness direction, and the connecting portion 7a is bent at a substantially right angle with respect to the fixing portion 7b. The independent bracket 7 is connected to the bracket connecting portion 9 of the case 2 such that the fixing portion 7b protrudes in a direction opposite to the direction in which the bracket portion 6 of the lid 3 protrudes.

  Here, a connection structure between the case 2 and the independent bracket 7 will be described. FIG. 3 is an enlarged perspective view showing a connection structure between the independent bracket 7 and the case 2 in the in-vehicle electronic device 1 according to the embodiment of the present invention. The bracket connecting portion 9 includes two standing pieces 10 erected on the opening side end surface of the side wall 2b, and a substantially hemispherical convex portion 11 protruding from the opening side end surface between the two standing pieces 10. Consists of including. Further, the connecting portion 7a of the independent bracket 7 has a rectangular plate shape, has a length of about half the depth of the accommodating space inside the case 2, and penetrates in the thickness direction in the vicinity of the center. A hole is formed.

  The standing piece 10 is composed of a first portion 10a standing at a right angle from the opening-side end surface and a second portion 10b bent at a right angle with respect to the first portion 10a. The first portions 10a are provided so as to be parallel to each other, and are separated by a distance approximately equal to the width of the connecting portion 7a of the independent bracket 7. Each second portion 10b is bent in a direction in which the second portions 10b approach each other, and the second portion 10b and the opening-side end surface are separated by a distance approximately equal to the thickness of the independent bracket 7.

  The connecting portion 7a of the independent bracket 7 is connected by being fitted into a fitting portion formed by the two standing pieces 10 and the opening side end face. At this time, the convex portion 11 of the bracket connecting portion 9 is fitted into the through hole of the independent bracket 7, and the independent bracket 7 is connected between the convex portion 11 and the second portion 10 b of the two standing pieces 10. The part 7a is clamped. Further, the distal end of the connecting portion 7a is in contact with the movement restricting portion 12 that protrudes from the opening side end face. Thus, by fitting the connecting portion 7a to the fitting portion, the independent bracket 7 can be reliably connected to the case 2 without causing rattling. In this way, by configuring the connection structure by a part of the case 2, the case 2 and the independent bracket 7 can be easily and reliably connected without increasing the number of parts.

  The vehicle-mounted electronic device 1 configured as described above is arranged so that the lid 3 faces the mounting surface of the vehicle body frame, and the bolt insertion holes formed in the two bracket portions 6 and the one independent bracket 7 respectively. The bolts are inserted into the bolts 6a and 7c and fastened to the vehicle body frame. In detail, the vehicle-mounted electronic device 1 according to the present embodiment is attached to a front center portion of the vehicle interior, that is, a position below the center tunnel between the driver seat and the passenger seat. At this time, since the direction in which the bracket portion 6 extends with respect to the case 2 is opposite to the direction in which the fixing portion 7b of the independent bracket 7 extends, as shown in FIG. The in-vehicle electronic device 1 can be attached to the vehicle such that the independent bracket 7 is disposed on the vehicle front side and the independent bracket 7 is disposed on the vehicle rear side.

  Hereinafter, the operation at the time of a vehicle collision in the in-vehicle electronic device 1 having the above-described configuration will be described. It is assumed that a collision has occurred in front of the vehicle. For example, in the case of a high-speed offset collision, the impact caused by the collision is transmitted to the in-vehicle electronic device 1, that is, the circuit board 4 on which the G sensor is mounted within 0.01 sec after the vehicle collision. The body deformation starts after about 0.05 sec from the vehicle collision.

  Since the on-vehicle electronic device 1 is firmly fixed to the vehicle via the three brackets 6 and 7 as described above, the impact caused by the collision of the vehicle is mounted on the circuit board 4 from the body frame. It is possible to reliably transmit to the sensor without any acceleration or attenuation.

  When the vehicle body deformation is started from the front of the vehicle, the lid 3 fixed to the vehicle body frame on the front side of the vehicle and the fastening screws 8 at four positions to the lid 3 are securely fixed. The case 2 and the circuit board 4 are moved together. In the following, the part that moves as a unit will be referred to as a “rigid part”. On the other hand, the independent bracket 7 is provided on the vehicle rear side, the connecting portion 7a is connected to the bracket connecting portion 9 of the case 2 that moves integrally with the lid 3, and the fixing portion 7b is attached to the vehicle body frame. It is fastened and fixed. That is, since the independent bracket 7 is connected to the case 2 in a structurally divided state and is attached to the vehicle body frame, the rigid body portion that moves as a unit is stressed. And behave differently in terms of mechanical properties such as strain.

  In this way, by configuring the rigid body portion, which is a structural system connected to the bracket portion 6, and the independent bracket 7 so as to behave differently with respect to external force due to deformation of the vehicle body, it is independent of the rigid body portion that moves together. An easily breakable region can be generated between the mold bracket 7 and deformation or separation can easily occur.

  Specifically, the separation between the fixed portion 7b of the independent bracket 7 and the rigid body portion is held by the connecting portion 7a of the independent bracket 7 being damaged by the standing piece 10 in the bracket connecting portion 9 being damaged. When the stand-alone bracket 7 itself is separated from the rigid body portion by being released from the state, and when a break occurs in the bent portion between the connecting portion 7a and the fixed portion 7b in the stand-alone bracket 7 In some cases, only the fixing portion 7b of the independent bracket 7 is separated from the rigid body portion, and this differs depending on how the front portion of the vehicle is deformed by a collision of the vehicle. However, in any case, the fixed portion 7b of the independent bracket 7 and the rigid body portion are separated, so that the distortion generated in the case 2 made of hard resin due to the deformation of the vehicle body can be reduced as much as possible. . Therefore, the load on the circuit board 4 accommodated in the case 2 is reduced, distortion generated in the circuit board 4 can be reduced, and the case 2 is destroyed and the circuit board 4 is exposed to the outside. This can be prevented.

  Further, since one of the bosses for fixing the circuit board 4 is disposed in the vicinity of the bracket connecting portion 9, it is possible to promote separation between the fixing portion 7b and the rigid portion of the independent bracket 7 as described above. .

  Further, the in-vehicle electronic device 1 is configured so that the bracket portion 6 can be attached to the vehicle such that the independent bracket 7 is disposed on the vehicle front side where the vehicle collision occurs and the vehicle rear side. Therefore, separation between the fixed portion 7b and the rigid portion of the independent bracket 7 as described above can be promoted.

  As described above, the in-vehicle electronic device 1 according to the present embodiment can reduce distortion generated in the circuit board 4 and prevent the case 2 from being broken and the circuit board 4 being exposed to the outside. Therefore, even when the vehicle body is deformed due to a vehicle collision, it is possible to prevent the metal powder from directly adhering to or coming into contact with the circuit board 4 and destroying the circuit board 4 due to heat generation and distortion due to a short circuit. Thus, the circuit board 4 can be reliably protected. Furthermore, the impact at the time of a vehicle collision can be reliably transmitted to the G sensor housed inside the case 2 without any attenuation. Moreover, since such a case 2 can be formed with a hard resin, the in-vehicle electronic device 1 that is light and inexpensive can be realized.

  As described above, the in-vehicle electronic device according to the present invention can be suitably used for an airbag control ECU for detecting an impact caused by a vehicle collision and controlling the airbag. However, the present invention is not limited to the airbag control ECU, and may be applied to other in-vehicle electronic devices mounted on the vehicle.

  In the above-described embodiment, the bracket portion 6 and the independent bracket 7 of the lid 3 are formed of a substantially plate-like metal, but may be formed of aluminum die casting. In this way, the bracket is damaged between the head of the bolt and the bracket when the bolt for fixing to the frame of the vehicle body is tightened compared to the case of forming with a synthetic resin. Therefore, it is not necessary to insert a member such as a collar for preventing this, and the cost can be reduced as the number of parts is reduced.

  In the above-described embodiment, only one independent bracket 7 is used. However, the vehicle-mounted electronic device 1 may be fixed to the vehicle body frame using a plurality of independent brackets.

  FIG. 4 is an enlarged perspective view showing a connection structure between the independent bracket 27 and the case 2 in the in-vehicle electronic device 21 according to another embodiment of the present invention. The in-vehicle electronic device 21 of the present embodiment is different only in the connection structure between the stand-alone bracket 7 and the case 2 in the above-described in-vehicle electronic device 1, and the other configurations are the same as the in-vehicle electronic device 1. Since they are configured in the same manner, the same reference numerals are assigned to the same components to avoid redundant description.

  The independent bracket 27 is formed of a substantially plate-like metal as a separate component independent of the case 2 and the lid 3, and is attached to a connecting portion 27 a connected to the case 2 and a vehicle body frame. A bolt insertion hole 27c through which the bolt is inserted has a fixing portion 27b formed so as to penetrate in the thickness direction, and the connecting portion 27a is bent at a substantially right angle with respect to the fixing portion 27b. The independent bracket 27 is connected to the bracket connecting portion 29 of the case 2 so that the fixing portion 27b protrudes in a direction opposite to the direction in which the bracket portion 6 of the lid 3 protrudes.

  Hereinafter, a connection structure between the case 2 and the independent bracket 27 will be described. The bracket connecting portion 29 is formed with an insertion hole through which the rivet 30 is inserted. Further, the connecting portion 27a of the independent bracket 27 has a rectangular plate shape, and the insertion hole through which the rivet 30 is inserted is arranged in the thickness direction at a position corresponding to the insertion hole formed in the bracket connecting portion 29. It is formed through. By inserting the rivet 30 into each insertion hole formed in the connection part 27a of the bracket connection part 29 and the independent bracket 27 and caulking the tip part of the rivet 30, the independent bracket 27 is removed from the case 2 with respect to the case 2. It can be securely connected without causing rattling. In this manner, the case 2 and the independent bracket 27 can be connected with a simple structure.

  Even when the vehicle-mounted electronic device 21 having such a connection structure is used, when the vehicle body deformation is started from the front portion of the vehicle, the rigid body portion moves integrally. On the other hand, the independent bracket 27 is provided on the vehicle rear side, the connecting portion 27a is connected to the bracket connecting portion 29 of the case 2 that moves integrally with the lid 3, and the fixing portion 27b is attached to the vehicle body frame. It is fastened and fixed. That is, the independent bracket 27 is connected to the case 2 in a structurally divided state and is attached to the vehicle body frame. And behave differently in terms of mechanical properties such as strain.

  In this way, by configuring the rigid body portion, which is a structural system connected to the bracket portion 6, and the independent bracket 27 to behave differently with respect to the external force due to the vehicle body deformation, the rigid body portion that moves integrally is independent. An easily breakable region can be generated between the mold bracket 27 and deformation or separation can easily occur.

  Specifically, the fixing part 27b of the independent bracket 27 and the rigid part are separated from each other by the connecting part 27a of the independent bracket 27 damaging the bracket connecting part 29, so that the independent bracket 27 itself is a rigid part. When the first bracket 27 is separated from the first and second brackets 27 and the second bracket 27 is broken at the bent portion between the connecting portion 27a and the fixed portion 27b, only the fixed portion 27b of the independent bracket 27 is separated from the rigid body portion. In some cases, it depends on how the front part of the vehicle is deformed. In the present embodiment, in the former case, the fastening screw 8 is positioned at a position closer to the bottom portion 2a than the fastening position by the rivet 30 so that the circuit board 4 is not exposed to the outside due to breakage of the bracket connecting portion 29. It is preferable to fix and hold the circuit board 4 by.

  Even if the fixing part 27b of the independent bracket 27 and the rigid body part are separated from each other as described above, the fixing part 27b and the rigid body part of the independent bracket 27 are separated from each other, so that the rigid body part is made by deformation of the vehicle body. The distortion generated in Case 2 can be reduced as much as possible. Therefore, the load on the circuit board 4 accommodated in the case 2 is reduced, distortion generated in the circuit board 4 can be reduced, and the case 2 is destroyed and the circuit board 4 is exposed to the outside. This can be prevented.

  As described above, the in-vehicle electronic device 21 according to the present embodiment can reduce distortion generated in the circuit board 4 and prevent the case 2 from being destroyed and the circuit board 4 being exposed to the outside. Therefore, even when the vehicle body is deformed due to a vehicle collision, it is possible to prevent the metal powder from directly adhering to or coming into contact with the circuit board 4 and destroying the circuit board 4 due to heat generation and distortion due to a short circuit. Thus, the circuit board 4 can be reliably protected. Furthermore, the impact at the time of a vehicle collision can be reliably transmitted to the G sensor housed inside the case 2 without any attenuation. Moreover, since such a case 2 can be formed with a hard resin, the in-vehicle electronic device 1 that is light and inexpensive can be realized.

1, 21 Vehicle-mounted electronic equipment 2 Case 3 Lid 4 Circuit board 5 Connector 6 Integrated bracket 7, 27 Independent bracket 8 Fastening screw 9, 29 Bracket connection

Claims (5)

A circuit board on which electronic components are mounted;
A housing that houses and holds the circuit board;
In the in-vehicle electronic device having a plurality of brackets for attaching the housing to the vehicle,
The plurality of brackets are
An integrated bracket integrally formed with the housing;
An in-vehicle electronic device comprising: an independent bracket formed as a separate component independent of the housing and coupled to the housing.   The in-vehicle use according to claim 1, wherein the independent bracket and the housing are connected by fitting a part of the independent bracket into a fitting portion formed in the housing. Electronics.   The in-vehicle electronic device according to claim 1, wherein the independent bracket and the housing are connected by a rivet.   The circuit board is fixed and held inside the housing by fastening with a fastener, and the independent bracket and the housing are connected in the vicinity of a fastening position by the fastener. The in-vehicle electronic device according to any one of claims 1 to 3.   The in-vehicle electronic device according to any one of claims 1 to 4, wherein the circuit board is mounted with an electronic component for causing an airbag mounted on a vehicle to be deployed when a vehicle collides. .

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