Control device

Abstract

To provide a technique that can properly protect a board which is located in a case of a control device.SOLUTION: A control device mounted on a vehicle comprises: a board provided with a control circuit for performing control at collision time of the vehicle; a case for accommodating the board; and a bracket which extends from a side face of the case, and is fixed to the vehicle by a fastening member. The bracket has a groove part which extends in a cross direction crossing a direction of extension of the bracket from the case, and a projection part which blocks a part of the groove part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device mounted on a vehicle.

Background Art

[0002] Conventionally, a control device that controls a safety device at the time of a vehicle collision, such as an airbag of a vehicle, is known (see, for example, Patent Document 1). In such a control device, an internal circuit board is covered with a metal housing, and the circuit board is protected so as not to be damaged by an impact or the like.

[0003] The control device includes a case (the above housing) that houses the circuit board, and a bracket that extends from a side surface of the case and is fixed to the vehicle with a fastening member. When a large force is applied to the case due to a vehicle collision or the like, the bracket and the case are broken and separated. Thereby, it is possible to suppress a large load from being applied to the circuit board in the case at the time of a vehicle collision or the like, and prevent damage to the circuit board. By preventing damage to the circuit board, it is possible to appropriately operate the airbag at the time of a collision or collect the operation record of the airbag afterwards.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a housing that controls a safety device at the time of a vehicle collision or the like, if the rigidity of the housing is too high, it may not be possible to appropriately separate the case and the bracket at the time of a vehicle collision or the like, and there is a concern that a large load may be applied to the circuit board. On the other hand, if the rigidity of the housing is insufficient, for example, there is a concern that the frequency at which the housing resonates decreases, and the housing is likely to shake due to resonance.

[0006] In view of the above points, an object of the present invention is to provide a technology capable of appropriately protecting a substrate disposed inside a case of a control device.

Means for Solving the Problems

[0007] An exemplary control device of the present invention is a control device mounted on a vehicle, and includes a substrate provided with a control circuit for performing control during a collision of the vehicle, a case for housing the substrate, and a bracket extending from a side surface of the case and fixed to the vehicle with a fastening member. The bracket has a groove portion extending in an intersecting direction intersecting the extending direction of the bracket from the case, and a protrusion portion closing a part of the groove portion.

Effects of the Invention

[0008] According to the present invention, a substrate disposed inside a case of a control device can be appropriately protected.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0010] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. The control device 1 according to the embodiment is mounted on a vehicle (not shown). In the drawings, an XYZ coordinate system is shown as a three-dimensional orthogonal coordinate system as appropriate. The X direction is a direction parallel to the traveling direction of the vehicle, with the +X side being the front side and the -X side being the rear side. The Y direction is orthogonal to the traveling direction of the vehicle and corresponds to the left-right direction as viewed by the driver sitting in the driver's seat. The +Y side is the right side and the -Y side is the left side. The Z direction is a direction orthogonal to the X direction and the Y direction and corresponds to the up-down direction. The +Z side is the upper side and the -Z side is the lower side. However, these directions are merely names used for explanation and are not intended to limit the actual positional relationship and direction.

[0011] <1. Overview of the control device> FIG. 1 is a schematic perspective view showing the configuration of a control device 1 according to an embodiment of the present invention. The control device 1 is a control device that controls a safety device during a vehicle collision. In this embodiment, the safety device is an airbag. That is, the control device 1 is, in detail, a control device that controls an airbag (not shown) of a vehicle. The control device 1 is a so-called airbag ECU (Electronic Control Unit). The control device 1 detects a vehicle collision using, for example, a sensor disposed in front of the vehicle, and activates the driver's seat airbag and the passenger seat airbag. The control device 1 is disposed, for example, at the front center inside the vehicle cabin of the vehicle. The control device 1 is disposed, for example, under the center console of the vehicle.

[0012] Note that in this embodiment, the configuration is such that the safety device controlled by the control device 1 is an airbag. However, the safety device may be other than an airbag, and may be, for example, a seat belt pretensioner, a control device for braking and steering for collision avoidance, an information recording device during an accident, a safety device for pedestrian protection, or the like.

[0013] FIG. 2 is a view in which some components are removed from the control device 1 shown in FIG. 1. As shown in FIGS. 1 and 2, the control device 1 includes a substrate 10, a case 11, and a bracket 12.

[0014] The substrate 10 is a substrate provided with a control circuit for performing control during a vehicle collision. A control circuit for controlling the airbag of the vehicle is provided on the substrate 10. Electronic components for controlling the airbag are mounted on the substrate 10. The electronic components include, for example, a microcomputer and the like. The substrate 10 is a printed circuit board such as a glass epoxy substrate, for example. In the present embodiment, the substrate 10 has a rectangular plate shape in a plan view from above. A connector 101 is disposed behind the upper surface of the substrate 10. The connector 101 functions as, for example, an input section for signals from an external device, an output section for signals to the external device, and a power connector. The external devices include an airbag, sensors disposed in front of the vehicle, and the like.

[0015] In the present embodiment, the substrate 10 is provided with a sensor 103 (see FIG. 2) for detecting impacts and vibrations generated in the vehicle, such as an acceleration sensor, in order to detect the collision state of the vehicle and the like. As shown in FIG. 2, the acceleration sensor 103 is disposed, for example, near the outer edge of the substrate 10. For example, when the resonance frequency decreases due to insufficient rigidity of the case 11, which will be described in detail later, the resonance frequency approaches the signal frequency band of the acceleration sensor 103 (the frequency band of the signal whose waveform appears when detecting a state such as during a collision), resulting in a decrease in the accuracy of the detection signal. That is, when the resonance frequency decreases, there is a possibility that an accurate collision determination cannot be made by the acceleration sensor 103. In the control device 1 of the present embodiment, a structure for suppressing a decrease in the resonance frequency is adopted as will be described later.

[0016] Case 11 houses the substrate 10. In the present embodiment, case 11 is made of metal. In the present embodiment, case 11 is composed of an upper case 111 and a lower case 112. For example, the upper case 111 is made of metal die casting such as aluminum die casting. Also, for example, the lower case 112 is composed of an iron-based sheet metal material. The upper case 111 and the lower case 112 may be made of different materials as in the present embodiment, or may be made of the same material. Note that FIG. 2 is a view in which the upper case 111 is excluded from the control device 1 shown in FIG. 1. As shown in FIG. 2, the lower case 112 is a rectangular plate-like member in a plan view from above, and the substrate 10 is placed on its upper surface.

[0017] The upper case 111 has a box shape with an opening downward. In the present embodiment, the upper case 111 has a rear opening 111a at the rear. The upper case 111 is placed over the lower case 112 on which the substrate 10 is placed, from above. The upper case 111 and the lower case 112 are fastened by screws 13 (see FIG. 4) extending in the vertical direction. The substrate 10 is housed in a space formed between the upper case 111 and the lower case 112 in the vertical direction. The substrate 10 has a substrate through hole 102 through which the screw 13 for fastening the upper case 111 and the lower case 112 passes. With the screw 13 passed through the substrate through hole 102, the upper case 111 and the lower case 112 are fastened with the screw 13, whereby the substrate 10 is fixed within the case 11. Note that in a state where the substrate 10 is housed in the case 11, the connector 101 is exposed outside the case 11 through the rear opening 111a of the upper case 111.

[0018] In this embodiment, as a preferred form, the case 11 has a case main body portion 11a and leg portions 11b. The case main body portion 11a holds the substrate 10. The leg portions 11b extend downward from the case main body portion 11a on the side surfaces of the case main body portion 11a. In other words, the leg portions 11b extend from the case main body portion 11a in the direction of the mounting surface of the vehicle on the side surfaces of the case main body portion 11a. They extend downward. Specifically, the case main body portion 11a is composed of a part of the upper case 111 and the lower case 112. The case main body portion 11a is mainly the portion that forms the accommodation space for the substrate 10. The leg portions 11b are provided on the left and right side surfaces of the case main body portion 11a. In this embodiment, the number of leg portions 11b is three in accordance with the number of brackets 12, which will be described in detail later. Two leg portions 11b are provided on the right side surface, and one leg portion 11b is provided on the left side surface. Note that in this embodiment, the leg portions 11b are constituted by a part of the upper case 111.

[0019] The bracket 12 extends from the side surface of the case 11. Specifically, the bracket 12 extends outward from the lower portions of the left and right side surfaces of the case 11. In this embodiment, the extending direction of the bracket 12 is a direction parallel to the left-right direction. Also, the bracket 12 is the same member as the upper case 111. The bracket 12 extends outward in the left-right direction from the lower portions of the left and right side surfaces of the upper case 111.

[0020] More specifically, the bracket 12 extends from the leg portion 11b. The bracket 12 extends outward in the left-right direction of the case 11 from the lower end portion of the leg portion 11b. By adopting a configuration in which the bracket 12 extends from the leg portion 11b, the lower surface of the case main body portion 11a in which the substrate 10 is accommodated can be arranged at a position higher than the bracket 12. That is, the substrate 10 can be arranged at a position higher than the bracket 12. For this reason, for example, when the bracket 12 is broken, it is possible to suppress the fragments generated by the breakage from falling on the substrate 10.

[0021] The bracket 12 is fixed to the vehicle by a fastening member 14. The bracket 12 is provided for fixing the case 11 that houses the substrate 10 to the vehicle. In the present embodiment, the bracket 12 is flat and is fixed to the mounting surface disposed on the vehicle using the fastening member 14. The fastening member 14 is, for example, a bolt used in combination with a nut, a screw, or the like. A bracket through-hole 121 that penetrates in the vertical direction is provided at the central portion of the bracket 12 to allow the fastening member 14 to pass through.

[0022] In the present embodiment, the bracket 12 includes a first bracket 12a, a second bracket 12b, and a third bracket 12c. The first bracket 12a and the second bracket 12b extend rightward from the right side surface of the case 11. The third bracket 12c extends leftward from the left side surface of the case 11. In other words, the control device 1 includes the brackets 12a and 12b provided on one side in the left-right direction of the case 11 (the extending direction in which the bracket 12 extends from the side surface of the case 11), and the bracket 12c provided on the other side.

[0023] Specifically, the first bracket 12a extends rightward from a leg portion 11b disposed in front of the right side surface. The second bracket 12b extends rightward from a leg portion 11b disposed behind the right side surface. The third bracket 12c extends leftward from a leg portion 11b disposed slightly in front of the central portion in the front-rear direction of the left side surface. The position of the third bracket 12c in the front-rear direction is behind the first bracket 12a and in front of the second bracket 12b.

[0024] In the present embodiment, the shapes and sizes of the first bracket 12a, the second bracket 12b, and the third bracket 12c are the same. However, the shapes and sizes of these three brackets 12a to 12c may be different. In the present embodiment, the outer shapes of the three brackets 12a to 12c are generally rectangular in a plan view from the vertical direction. Specifically, in each of the brackets 12a to 12c, the corners are R-shaped. However, the shape of the bracket 12 may be appropriately changed from the shape of the present embodiment.

[0025] In addition, in the present embodiment, the number of brackets 12 is three, but the number of brackets 12 may be two or four or more. For example, when the number of brackets 12 is two, the brackets 12 may be provided one each on the right side surface and the left side surface of the case 11. Further, for example, when the number of brackets 12 is four, the brackets 12 may be provided two each on the right side surface and the left side surface of the case 11. Also, the position in the front-rear direction where the brackets 12 are arranged may be changed as appropriate.

[0026] In addition, in the present embodiment, the orientation of the control device 1 is the orientation in which the brackets 12 are arranged on the left and right sides of the case 11, but this is merely an example. For example, the orientation of the control device 1 may be the orientation in which the brackets 12 are arranged in the front-rear direction of the case 11.

[0027] <2. Detailed Configuration of Bracket> The control device 1 fixed to a predetermined location of the vehicle using the bracket 12 may receive a force from the side direction (the left and right direction in the present embodiment) due to the deformation of the vehicle during a vehicle collision. The control device 1 of the present embodiment is configured such that when a force of a certain level or more is applied upon receiving the force from the side direction, breakage occurs and the case 11 and the bracket 12 are separated. Thereby, it is possible to suppress a large load from being applied to the substrate 10 in the case 11. Hereinafter, the structure for promoting the above breakage employed in the bracket 12 will be described in detail.

[0028] FIG. 3 is a schematic plan view showing the configuration of the control device 1 according to an embodiment of the present invention. FIG. 4 is a view showing a part of a cross section at the IV-IV position shown in FIG. 3. FIG. 5 is a view showing a part of a cross section at the V-V position shown in FIG. 3. In the present embodiment, the bracket 12 includes a first bracket 12a, a second bracket 12b, and a third bracket 12c. All of these three brackets 12a to 12c are provided with a structure that promotes the above-mentioned breakage. FIGS. 4 and 5 illustrate the case of the second bracket 12b, but the first bracket 12a and the third bracket 12c also have the same structure. For this reason, in the description of the structure that promotes the above-mentioned breakage, unless particularly necessary, the first bracket 12a, the second bracket 12b, and the third bracket 12c are simply described as the bracket 12 without particularly distinguishing them.

[0029] As shown in FIGS. 3 to 5, the bracket 12 has a groove portion 122 disposed on the upper surface of the base portion of the bracket 12. In the present embodiment, the upper surface of the bracket 12 is a plane extending in a direction parallel to the front-rear direction and the left-right direction. The base portion of the bracket 12 is a part of the bracket 12 including the boundary between the case 11 and the bracket 12.

[0030] The groove portion 122 extends in an intersecting direction that intersects the extending direction of the bracket 12 from the case 11. In the present embodiment, the groove portion 122 is recessed downward. The groove portion 122 extends from one end to the other end of the bracket 12 in the intersecting direction. Specifically, the groove portion 122 is a portion recessed downward from the upper surface of the bracket 12. The portion where the groove portion 122 is provided has a reduced thickness of the bracket 12 in the vertical direction. In the present embodiment, the extending direction is the left-right direction, and the intersecting direction intersecting the extending direction is the front-rear direction. That is, the groove portion 122 disposed on the upper surface of the bracket 12 extends in the front-rear direction. The groove portion 122 extends from the front end to the rear end of the bracket 12.

[0031] The bracket 12 has a protrusion 123 that closes a part of the groove 122. The protrusion 123 protrudes from the inner surface of the groove 122, and at least a part thereof is disposed inside the groove 122. In the present embodiment, the protrusion 123 protrudes upward from the bottom surface (lower surface) of the groove 122. Further, the protrusion 123 connects two inner surfaces facing each other in the left-right direction of the groove 122.

[0032] FIGS. 6 and 7 are diagrams for explaining the operation of the protrusion 123 included in the bracket 12. FIG. 6 is a schematic perspective view showing the bracket 12 (second bracket 12b) and the surrounding structure. FIG. 7 is an enlarged view of the portion surrounded by the broken line in FIG. 6. FIG. 7 shows the simulation result using analysis software. Specifically, FIG. 7 shows the simulation result of the stress distribution when a force is applied from the right side surface to the left side surface of the case 11 of the control device 1 fixed to the vehicle using three brackets 12a to 12c. In FIG. 7, the darker the hatching color, the greater the stress.

[0033] The inventors of the present application provided the protrusion 123 that changes the shape of the groove 122 in a part of the groove 122, thinking that stress is likely to concentrate in that part. In the simulation result using analysis software shown in FIG. 7, the stress is large at the protrusion 123 and its periphery. That is, it was confirmed from the simulation result that by providing the protrusion 123 in a part of the groove 122, it is possible to promote breakage at the position where the groove 122 is provided.

[0034] As can be understood from the above, in the present embodiment, when a force is applied to the case 11 of the control device 1 from the side direction (left - right direction), a groove portion 122 is provided at the base portion of the bracket 12 where stress is likely to concentrate. That is, when a force is applied to the case 11 from the side direction (left - right direction), the thickness of the portion where stress is likely to concentrate in the bracket 12 is made thin. For this reason, in the present embodiment, it is possible to easily cause a break that separates the case 11 and the bracket 12. And, in the present embodiment, since a protrusion portion 123 that promotes stress concentration is provided in the groove portion 122, it is possible to promote breakage at the position where the groove portion 122 is provided. That is, when a large force is applied to the case 11 from the side direction of the control device 1 due to a vehicle collision, it is possible to promote the separation of the case 11 and the bracket 12 by breakage and suppress a large load from being applied to the substrate 10 in the case 11. That is, the substrate 10 in the case 11 can be appropriately protected.

[0035] Note that, in the present embodiment, since the leg portion 11b is provided on the case 11, the bracket 12 can be separated from the case 11 at a height position lower than the height position where the substrate 10 is provided. For this reason, the possibility that a crack enters the case 11 at the height position where the substrate 10 is provided is low, and the possibility that fragments generated along with the breakage come into contact with the substrate 10 can be suppressed low. That is, in the present embodiment, the possibility that damage occurs to the substrate 10 due to fragments generated by the breakage can be suppressed low.

[0036] In this embodiment, the longitudinal cross-section of the protrusion 123 is substantially semi-circular (see Fig. 5). However, the shape of the protrusion 123 may be another shape. For example, the longitudinal cross-section of the protrusion 123 may be tapered upward. Also, if the range occupied by the protrusion 123 in the front-rear direction within the groove 122 extending in the front-rear direction becomes too large, conversely, fracture may be less likely to be promoted. For this reason, it is preferable to make the length (width) of the protrusion 123 in the front-rear direction within the groove 122 as small as possible within the manufacturable range. For example, the length of the protrusion 123 in the front-rear direction is preferably less than 1 / 8 of the total length of the groove 122 in the front-rear direction.

[0037] The protrusion 123 is preferably disposed near at least one of the two ends in the front-rear direction (the intersecting direction intersecting the extending direction from the case 11 of the bracket 12) of the groove 122. In the portion of the bracket 12 where the groove 122 is provided, the stress tends to concentrate more easily on the end side in the extending direction of the groove 122. For this reason, the protrusion 123 that promotes stress concentration is preferably provided on the end side of the groove 122. By configuring in this way, the effect of providing the protrusion 123 to concentrate the stress can be obtained more efficiently.

[0038] In this embodiment, in a more preferable form, the protrusions 123 are disposed near both ends in the front-rear direction of the groove 122. That is, the number of the protrusions 123 is two. Note that the number of the protrusions 123 may be one or three or more. However, the number of the protrusions 123 is preferably two or less.

[0039] In the present embodiment, as a preferred form, the protrusion 123 is disposed inward in the front-rear direction from the ends in the front-rear direction (the intersecting direction intersecting the extending direction from the case 11 of the bracket 12) of the groove 122. However, the protrusion 123 may be disposed at the ends in the front-rear direction of the groove 122. Specifically, the protrusion 123 is disposed inward in the front-rear direction from the ends in the front-rear direction of the groove 122 in the vicinity of both ends in the front-rear direction of the groove 122. In the vicinity of the front end of the groove 122, the protrusion 123 is disposed at a position rearward of the front end of the groove 122. In the vicinity of the rear end of the groove 122, the protrusion 123 is disposed at a position forward of the rear end of the groove 122.

[0040] As shown in FIG. 5, the thickness in the vertical direction at the portion where the groove 122 of the bracket 12 is provided is thinner on the outer side in the front-rear direction than on the inner side in the front-rear direction with respect to the protrusion 123. In other words, the depth of the groove 122 is deeper on the outer side in the intersecting direction (front-rear direction) than on the inner side in the intersecting direction with respect to the protrusion 123. Specifically, on the front-end side in the front-rear direction of the groove 122, the thickness of the bracket 12 is thinner on the front-end side (outer side) than on the rear-end side (inner side) with respect to the protrusion 123. In other words, on the front-end side in the front-rear direction of the groove 122, the depth of the groove 122 is deeper on the front-end side (outer side) than on the rear-end side (inner side) with respect to the protrusion 123. On the rear-end side in the front-rear direction of the groove 122, the thickness of the bracket 12 is thinner on the rear-end side (outer side) than on the front-end side (inner side) with respect to the protrusion 123. In other words, on the rear-end side in the front-rear direction of the groove 122, the depth of the groove 122 is deeper on the rear-end side (outer side) than on the front-end side (inner side) with respect to the protrusion 123.

[0041] Thus, when the thickness in the vertical direction of the portion where the groove 122 of the bracket 12 is provided is configured to be thinner at the ends in the front-rear direction, it is possible to easily promote breakage at the position where the groove 122 is provided when a force is applied from an oblique direction (a direction inclined with respect to the left-right direction) to the case 11. Note that the thickness in the vertical direction at the portion where the groove 122 of the bracket 12 is provided may be configured such that it is the same between the inner side and the outer side in the front-rear direction with reference to the protrusion 123, or other configurations may be used.

[0042] At least a part of the upper surface of the protrusion 123 is preferably at the same height as the upper end of the groove 122 or lower than the upper end of the groove 122. In the present embodiment, the protrusion 123 is provided so as to protrude from the bottom of the groove 122 in the direction of the entrance of the groove 122. The protruding end of the protrusion 123 is preferably at the same height as the entrance portion of the groove 122 or lower than the entrance portion of the groove 122. By configuring in this way, when attaching the bracket 12 to the mounting surface (not shown) of the vehicle, the possibility of the protrusion 123 getting in the way can be reduced. Further, by making at least a part of the upper surface of the protrusion 123 the same height as the upper end of the groove 122, the generation of unevenness due to the provision of the protrusion 123 can be suppressed, and manufacturing such as casting can be facilitated.

[0043] Note that the entrance portion of the groove 122 corresponds to the opening surface located on the opposite side to the bottom surface of the groove 122 in the direction parallel to the direction in which the groove 122 provided in a concave cross-sectional shape is recessed. In the present embodiment, the "entrance portion of the groove 122" corresponds to the "upper end (upper end opening surface) of the groove 122". Further, "protruding from the bottom of the groove 122 in the direction of the entrance of the groove 122" corresponds to "protruding upward". Also, the "protruding end of the protrusion 123" corresponds to the "upper end of the protrusion 123".

[0044] Specifically, in the present embodiment, the upper end (entrance portion) of the groove 122 is at the same height position as the upper surface of the bracket 12. Further, in the present embodiment, as shown in FIG. 4, the upper surface of the protrusion 123 is, in most parts, at the same height as the upper end of the groove 122. However, the protrusion 123 is higher than the upper end of the groove 122 at the root side end of the bracket 12 (the left end in the example shown in FIG. 4).

[0045] <3. Detailed Configuration of the Leg Portion> In this embodiment, it includes brackets 12a and 12b provided on the right side of the case 11 and a bracket 12c provided on the left side. In such a configuration, when a force is applied from the right side of the case 11, due to the effects of the above-described groove portion 122 and protrusion portion 123, the brackets 12a and 12b on the right side are liable to break and are liable to be separated from the case 11. On the other hand, when a force is applied from the right side of the case 11, the bracket 12c on the left side has a smaller effect of the groove portion 122 and the protrusion portion 123 provided compared with the brackets 12a and 12b on the right side. That is, when a force is applied from the right side of the case 11, the bracket 12c on the left side is less likely to break and is less likely to be separated from the case 11 compared with the brackets 12a and 12b on the right side.

[0046] Similarly, when a force is applied from the left side of the case 11, the bracket 12c on the left side is liable to break and is liable to be separated from the case 11. On the other hand, when a force is applied from the left side of the case 11, the brackets 12a and 12b on the right side are less likely to break and are less likely to be separated from the case 11 compared with the bracket 12c on the left side.

[0047] Considering the above points, in this embodiment, the shape of the leg portion 11b is devised. This will be described with reference to FIGS. 8 and 9. FIG. 8 is a schematic rear view showing the configuration of the control device 1 according to the embodiment of the present invention. FIG. 9 is a view showing a cross section at the IX-IX position shown in FIG. 8. In this embodiment, three leg portions 11b are provided. The three leg portions 11b all have the same structure. That is, although FIG. 9 illustrates the case of the leg portion 11b connected to the third bracket 12c, the leg portion 11b connected to the first bracket 12a and the leg portion 11b connected to the third bracket 12c also have the same structure.

[0048] As shown in FIGS. 8 and 9, the leg portion 11b has a thin-walled portion 113 that is above the bracket 12 and has a thickness thinner than the width of the leg portion 11b in the left-right direction (the extending direction from the side surface of the case 11 of the bracket 12). In other words, the leg portion 11b has a thin-walled portion 113 that is on the side of the case main body portion 11a rather than the bracket 12 and has a thickness thinner than the width of the leg portion 11b in the left-right direction (the extending direction from the side surface of the case 11 of the bracket 12). Specifically, the width of the leg portion 11b in the left-right direction is the left-right distance (distance L in FIG. 9) between the rightmost end and the leftmost end of the leg portion 11b.

[0049] By forming the thin-walled portion 113 in the leg portion 11b in this way, when a force is applied to the side of the case opposite to the side where the leg portion 11b is provided in the left-right direction, it is possible to easily cause the leg portion 11b to break. That is, it is possible to easily cause the separation between the case 11 and the bracket 12, and it is possible to reduce the possibility of damage to the substrate 10 housed inside the case 11. In addition, since the leg portion 11b is provided at a position lower than the substrate 10 housed in the case main body portion 11a, even if the leg portion 11b breaks, it is possible to keep the possibility that the fragments generated by the break contact the substrate 10 low. That is, in the present embodiment, even if the leg portion 11b breaks, it is possible to keep the possibility that damage occurs to the substrate 10 due to the fragments generated by the break low.

[0050] Specifically, the thin-walled portion 113 includes a first thin-walled portion 113a and a second thin-walled portion 113b. The first thin-walled portion 113a is configured by providing notch portions 114 on the inner surfaces in the left-right direction (the extending direction of the bracket 12) at both ends in the front-rear direction (the intersecting direction intersecting the extending direction of the bracket 12) of the leg portion 11b. Taking the leg portion 11b as a reference, the direction in which the bracket 12 extends is the outer side, and the opposite direction is the inner side. Specifically, the inner surfaces in the left-right direction of each leg portion 11b connected to the first bracket 12a and the second bracket 12b are the left surfaces of the leg portion 11b. The inner surface in the left-right direction of the leg portion 11b connected to the third bracket 12c is the right surface of the leg portion 11b. In the example shown in FIG. 9, the right surfaces of the front end and the rear end of the leg portion 11b are cut out to form the first thin-walled portion 113a.

[0051] The second thin-wall portion 113b is configured by providing a concave portion 115 on the outer surface in the left-right direction (the extending direction of the bracket 12) at the central portion in the front-rear direction (the intersecting direction intersecting the extending direction of the bracket 12) of the leg portion 11b. Specifically, the outer surfaces in the left-right direction of each leg portion 11b connected to the first bracket 12a and the second bracket 12b are the right surfaces of the leg portion 11b. The outer surfaces in the left-right direction of the leg portion 11b connected to the third bracket 12c are the left surfaces of the leg portion 11b. In the example shown in FIG. 9, the left surface at the central portion in the front-rear direction of the leg portion 11b is recessed to the right to form the second thin-wall portion 113b.

[0052] As in the present embodiment, a stepped shape is formed by providing the first thin-wall portion 113a by notching both ends in the front-rear direction of the leg portion 11b. By forming the stepped shape, stress can be concentrated on this portion to promote fracture. Further, by providing the second thin-wall portion 113b with a reduced thickness of the leg portion 11b by recessing the central portion in the front-rear direction of the leg portion 11b, the rigidity of this portion can be lowered to make fracture more likely to occur.

[0053] In the control device 1 of the present embodiment, due to changes in the attachment location of the case 11 to the vehicle and changes in the vehicle body structure of the vehicle, etc., the distance (the distance in the vertical direction) between the case main body portion 11a and the attachment surface of the bracket 12 is larger than before. That is, the leg portion 11b is longer than before. In such a configuration, if the leg portion 11b is simply made into a thin plate shape so that fracture is likely to occur, a decrease in the resonance frequency due to a decrease in rigidity may become a problem. As described above, when the resonance frequency decreases, for example, accurate collision determination may not be possible by the acceleration sensor 103. On the other hand, if the thickness near the leg portion 11b is increased to suppress a decrease in rigidity, fracture may be less likely to occur.

[0054] In this regard, in the present embodiment, rather than simply increasing or decreasing the thickness of the leg portion 11b, as described above, thick portions and thin portions are provided at appropriate positions on the leg portion 11b. By configuring in this way, rigidity is ensured during normal times, making it difficult for resonance to occur at low frequencies, and when a vehicle collision occurs, it is easy to cause a break for separating the case 11 and the bracket 12.

[0055] <4. Precautions, etc.> Among the various technical features disclosed in this specification, in addition to the above-described embodiment, various modifications can be made without departing from the gist of the technical creation. That is, the above-described embodiment should be considered as illustrative in all respects and not restrictive, and the technical scope of the present invention is indicated not by the description of the above-described embodiment but by the scope of the claims, and it should be understood that all modifications belonging to the meaning and scope equivalent to the scope of the claims are included. Also, the plurality of embodiments and modifications shown in this specification may be implemented in appropriate combination within the possible range.

Explanation of Reference Numerals

[0056] 1 ··· Control device 10 ··· Substrate 11 ··· Case 11a ··· Case main body portion 11b ··· Leg portion 12 ··· Bracket 14 ··· Fastening member 103 ··· Acceleration sensor 113 ··· Thin-walled portion 113a ··· First thin-walled portion 113b ··· Second thin-walled portion 114 ··· Notch portion 115 ··· Concave portion 122 ··· Groove portion 123 ··· Protrusion portion

Claims

1. A control device mounted on a vehicle, comprising: a substrate provided with a control circuit for performing control during a collision of the vehicle; a case for housing the substrate; a bracket extending from a side surface of the case and fixed to the vehicle by a fastening member; The control device is provided with: The bracket has: a groove portion extending in an intersecting direction intersecting with an extending direction of the bracket from the case; a protrusion portion closing a part of the groove portion; The control device has: The groove portion extends from one end to the other end of the bracket in the intersecting direction; The protrusion portion is disposed in the vicinity of at least one end of both ends of the groove portion in the intersecting direction and inward of the intersecting direction from an end of the groove portion in the intersecting direction; The depth of the groove portion is deeper on the outer side in the intersecting direction than on the inner side in the intersecting direction compared to the protrusion portion.

2. The protrusion portion is provided so as to protrude from the bottom of the groove portion in the entrance direction of the groove portion, The control device according to claim 1, wherein a protruding end of the protrusion portion is at the same height as an entrance portion of the groove portion or at a height lower than the entrance portion.

3. The case has: a case main body portion for holding the substrate; a leg portion extending from a side surface of the case main body portion in a direction of an attachment surface of the vehicle from the case main body portion; The control device has: The bracket extends from the leg portion. The control device according to claim 1 or 2.

4. The control device includes the bracket provided on one side in the extending direction of the case and the bracket provided on the other side, The control device according to claim 3, wherein the leg portion has a thin-walled portion that is thinner in thickness than the width of the leg portion in the extending direction and is closer to the case main body portion side than the bracket.

5. The control device according to any one of claims 1 to 4, wherein an acceleration sensor is provided on the substrate.

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