JP2015198224A - Holding structure of substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a holding structure of a substrate which positions the substrate relative to a housing and prevents deformation of the housing which is caused by a difference between linear expansion coefficients of itself and the substrate.SOLUTION: A holding structure of a substrate of the invention holds a substrate 4 on a housing 3 and includes: at least one fixing means A1 which fixes the substrate 4 to the housing 3; and at least one floating support means A2 which supports the substrate 4 on the housing 3 so that the substrate 4 may move in a direction that the substrate 4 moves close to or separates from a fixing point fixed by the fixing means A1.

Description

  The present invention relates to a substrate holding structure.

  Patent Document 1 discloses a holding structure in which four corners of a substrate are fixed to a chassis, and a central portion of the substrate is elastically held by an elastic piece provided on the chassis. Cited Document 2 shows a structure in which a substrate is floatingly supported on a casing by screwing a substrate fixture having a rigid cylinder disposed inside an elastic member.

JP 2012-64985 A

  As shown in Patent Document 1, if the four corners of the substrate are fixed integrally to the housing, stress may be generated due to a difference in linear expansion coefficient between the substrate and the housing, and the housing may be distorted. If the housing is distorted, there is a risk of affecting the mounting accuracy when the housing is attached to the mounting position as a product. On the other hand, when the substrate is floatingly supported on the housing as shown in Patent Document 2, it is difficult to position the substrate relative to the housing. Therefore, it is difficult to properly maintain the clearance between the screw and the hole of the substrate, and there is a possibility that the assembly accuracy as a product may be affected.

  The present invention has been made in view of the above points, and an object of the present invention is to enable relative positioning of the substrate with respect to the housing and to prevent distortion of the housing due to a difference in linear expansion coefficient from the substrate. It is to provide a substrate holding structure that can be used.

  The substrate holding structure of the present invention that solves the above problems is a structure that holds a substrate in a housing, and includes at least one fixing means that fixes the substrate to the housing, and a fixing that is fixed by the fixing means. And at least one floating support means for supporting the substrate on the casing so as to be movable in a direction approaching and separating from the point.

  ADVANTAGE OF THE INVENTION According to this invention, the board | substrate holding structure which can position the board | substrate relative to a housing | casing and can prevent distortion of a housing | casing by the difference in a linear expansion coefficient with a board | substrate can be obtained. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

It is a figure which shows typically the vehicle carrying a stereo camera apparatus, FIG. 1 (a) is a side view, FIG.1 (b) is a top view. The left view of a stereo camera apparatus. The rear view of a stereo camera apparatus. The bottom view of a stereo camera apparatus. The bottom view which shows the state which removed the lower cover. The bottom view which shows the state which removed the board | substrate. VII-VII line sectional drawing of FIG. VIII-VIII sectional view taken on the line of FIG.

Next, an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram schematically showing a vehicle equipped with a stereo camera device, in which FIG. 1 (a) is a side view and FIG. 1 (b) is a plan view.

  In this embodiment, the substrate holding structure of the present invention is applied to an in-vehicle stereo camera device. As shown in FIG. 1A, the stereo camera device 1 is disposed in the vehicle interior of the vehicle M, and images the front of the vehicle through the windshield. As shown in FIG. 1B, the stereo camera device 1 has a pair of left and right imaging units 2R and 2L, calculates parallax from a pair of images captured by the imaging units 2R and 2L, and obtains a distance image. Is generated. The distance image generated by the stereo camera device 1 is used for vehicle control, alarm control, or the like that avoids a collision with an obstacle such as another vehicle or a pedestrian.

  2 is a left side view of the stereo camera device, FIG. 3 is a rear view of the stereo camera device, FIG. 4 is a bottom view of the stereo camera device, and FIG. 5 is a bottom view showing a state in which the lower cover is removed. 6 is a bottom view showing a state in which the substrate is removed.

  For example, as shown in FIG. 5, the stereo camera device 1 includes a housing 3 having imaging units 2 </ b> R and 2 </ b> L and a substrate 4 attached to the housing 3. The housing 3 has an elongated and thin rectangular shape that extends to the left and right with a substantially constant width, and imaging units 2R and 2L are provided at both ends in the longitudinal direction. The housing 3 includes a substrate housing portion 31 that houses the substrate 4 in cooperation with the lower cover 5 and a pair of cameras that are provided at both left and right ends of the substrate housing portion 31 and to which the imaging units 2R and 2L are respectively fixed. The fixing portion 32 and a vehicle body member fixing portion 33 that protrudes from the front end and the rear end of the substrate housing portion 31 in the front-rear direction and is fixed to a vehicle body member such as a ceiling of a vehicle compartment.

  As shown in FIG. 6, the substrate housing portion 31 includes a flat upper surface portion 31 a that is substantially rectangular in plan view, and a vertical wall portion 31 b that is erected so as to be circumferentially continuous along the periphery of the upper surface portion 31 a. It has a box shape, and the substrate 4 is accommodated in an internal space surrounded by the upper surface portion 31a and the vertical wall portion 31b.

  The pair of camera fixing portions 32 has an extending portion 32a extending in a direction away from the substrate housing portion 31, and a hanging lower surface portion 32b bent at the front end of the extending portion 32a and depending downward. As shown in FIG. 2, the cross section is L-shaped, and the imaging units 2R and 2L are fixed to the front surface of the hanging surface portion 32b.

  The vehicle body member fixing portion 33 includes a pair of left and right projections 33a projecting from the front vertical wall portion 31b of the substrate housing portion 31, and one projection projecting from the vertical wall portion 31b rearward of the substrate housing portion 31. Through holes 33c and 33d are formed in the portion 33b, respectively. And the housing | casing 3 is fixed to a vehicle body member by inserting the fixing bolt not shown in these through-holes 33c and 33d, and screwing the front-end | tip of a fixing bolt with a vehicle body member.

  The imaging units 2R and 2L have an imaging element such as a CCD or CMOS and a lens, and the camera fixing unit of the housing 3 via a calibration mechanism 21 that can finely adjust the optical axis of the lens and the position of the imaging element. 32 is fixed. A signal cable 22 for outputting a captured image signal to the substrate 4 is connected to the imaging units 2R and 2L.

  The substrate 4 is made of a material containing a synthetic resin such as glass epoxy, for example, and various electronic components for constituting an electronic circuit are mounted on a substrate body 41 having an elongated rectangular shape that is disposed in the substrate accommodating portion 31. The board body 41 is provided with a connector 43 into which a communication cable for communicating with the ECU of the vehicle is inserted and removed. The connector 43 is disposed at a position continuous with the opening hole 31 d opened on the rear surface of the substrate housing portion 31, and the communication cable is inserted and removed from the rear of the substrate housing portion 31.

  Of the electronic components mounted on the substrate 4, electronic components such as a microcomputer, LSI, and power supply regulator are heat generating components 42 that generate heat when energized. Therefore, as shown in FIG. 6, the upper surface portion 31 a of the substrate housing portion 31 has a convex portion 31 c serving as a heat sink at a position corresponding to the heat generating component 42 in order to actively absorb the heat of these heat generating components 42. The clearance with the substrate 4 is narrowed. The heat of the heat generating component 42 is transmitted to the convex portion 31c through the clearance, diffused throughout the housing 3, and radiated.

  Since the stereo camera device 1 calculates the parallax based on the pair of images captured by the imaging units 2R and 2L, in order to ensure the accuracy of calculating the parallax, the stereo camera device 1 can detect the displacement and vibration of the mounting positions of the imaging units 2R and 2L. It is necessary to suppress it. Accordingly, the housing 3 having the respective imaging units 2R and 2L is made of a light metal material so as to obtain a predetermined rigidity or more. In this embodiment, the housing 3 is formed by casting an aluminum alloy. .

  The aluminum alloy used for the housing 3 and the glass epoxy material used for the substrate body 41 have different linear expansion coefficients, and the aluminum alloy has a higher thermal expansion coefficient than the glass epoxy material. Therefore, for example, when the plurality of portions of the substrate 4 are fixed to the housing 3 so as not to move, that is, when fixed to the rigid, the housing 3 extends more than the substrate 4 due to thermal expansion. The housing 3 may be pulled by the substrate 4 and bending stress may act on the housing 3.

  In particular, in the present embodiment, since the casing 3 has a long and thin rectangular shape, the amount extending in the longitudinal direction is large. Therefore, if all of the plurality of locations on the substrate 4 are fixed, the housing 3 is likely to be distorted by bending stress, and the positions of the imaging units 2R and 2L provided at both ends thereof may change. When the positions of the imaging units 2R and 2L change, the base line length and the setting of the geometric system with the vehicle change, which may affect the detection accuracy of parallax.

  On the other hand, the stereo camera device 1 according to the present embodiment has a structure in which the substrate 4 is held in the housing 3 and is fixed by at least one fixing means A1 for fixing the substrate 4 to the housing 3 and the fixing means A1. And at least one floating support means A2 for supporting the substrate 4 on the housing 3 so as to be movable in a direction approaching and separating from the fixed point. Therefore, it is possible to position the substrate 4 relative to the housing 3 and to prevent the housing 3 from being distorted due to stress generated between the housing 3 and the substrate 4 during thermal expansion.

  The substrate 4 is fastened to the housing 3 at a total of five locations. More specifically, as shown in FIG. 5, the front portion of the substrate 4 is divided into left and right and fastened at two locations. The rear part is fastened to the left and right and its center. And only one place on the front left side of the substrate 4 is fixed integrally with the fixing means A1 so as not to move with respect to the housing 3, and the remaining four places are supported by the floating support means A2.

  The board | substrate 4 is fixed in the state positioned with respect to the housing | casing 3 by fixing means A1. Since the floating support means A2 supports the substrate 4 in the casing 3 so as to be movable toward and away from the fixing point fixed by the fixing means A1, the substrate 4 and the casing 3 are heated. When the casing 3 expands more than the substrate 4 due to expansion and a difference in linear expansion coefficient, the casing 3 can be prevented from being pulled by the substrate 4.

  7 is a cross-sectional view taken along the line VII-VII in FIG. 5 and is a cross-sectional view for explaining an example of the structure of the fixing means. FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. It is sectional drawing explaining an example.

  As shown in FIG. 7, the fixing means A1 has a screw hole screwed into the boss 34A of the housing 3 and a fixing screw 51 inserted through the through hole 41a of the substrate body 41 and screwed into the screw hole. The substrate body 41 is sandwiched and fixed between the head 53 of the fixing screw 51 and the boss 34A. The substrate 4 is integrally fixed to the housing 3 by the fixing means A1, and is positioned in the housing 3 within a gap between the through hole 41a of the substrate body 41 and the fixing screw 51 inserted through the through hole 41a. Is done.

  As shown in FIG. 8, the floating support means A2 is inserted into the screw hole formed in the boss 34B of the housing 3 and the through hole 41b of the substrate body 41, and the screw shaft portion 62 at the tip is screwed into the screw hole. It has a stepped screw 61 to be mated.

  The stepped screw 61 is provided at the base end of the thick shaft portion 63 rather than the screw shaft portion 62, the thick shaft portion 63 expanded in diameter at the base end, and the elastic O-ring 65 fitted to the thick shaft portion 63. The flange portion 64 is provided. The thick shaft portion 63 is inserted into the through hole 41 b of the substrate body 41.

  The outer diameter of the thick shaft portion 63 is such that when the substrate body 41 and the housing 3 are relatively moved in the sliding direction due to the difference in linear expansion coefficient between the housing 3 and the substrate body 41, the thick shaft portion 63 has a size that forms a gap allowing relative movement between the through hole 41b without contacting the substrate body 41. That is, between the thick shaft portion 63 and the through hole 41b of the substrate body 41, when the housing 3 and the substrate body 41 are thermally expanded, the substrate body 41 and the housing 3 are relatively moved in the sliding direction. Possible gaps are formed.

  The outer diameter of the thick shaft portion 63 is smaller than the outer diameter of the top surface of the boss 34B, and the outer diameter of the flange portion 64 is substantially the same as the outer diameter of the top surface of the boss 34B. 64 and the top surface of the boss 34B face each other. The stepped screw 61 is fixed to the housing 3 by the stepped surface between the screw shaft portion 62 and the thick shaft portion 63 coming into contact with the top surface of the boss 34B, and the flange portion 64 is connected to the top surface of the boss 34B. Are arranged opposite to each other with a certain interval. The substrate body 41 is pressed against the boss 34B with a predetermined pressing force by an O-ring 65 made of an elastic member fitted on the thick shaft portion 63, and the substrate body 41 can move in the sliding direction with respect to the boss 34B. In this state, it is supported by the housing 3.

  Therefore, for example, when the housing 3 and the substrate 4 are thermally expanded and the distance between the boss 34A and the boss 34B of the housing 3 is longer than the distance between the through hole 41a and the through hole 41b of the substrate 4. In addition, the substrate 4 can be slid relative to the boss 34B, the housing 3 can be prevented from being pulled by the substrate 4, and the housing 3 can be prevented from being distorted.

  In the stereo camera device 1, one point is fixed by the fixing means A1, and the other four points are floatingly supported by the floating support means A2. Therefore, the clearance between the thick shaft portion 63 of the stepped screw 61 and the through hole 41b of the substrate body 41 at the other four points can be appropriately maintained.

  In the above-described embodiment, the description has been given of the case where only one place on the left of the front portion of the substrate 4 is fixed by the fixing means A1, and the remaining four places are supported by the floating support means A2. Is not limited to one. For example, a plurality of fixing means A1 may be provided at positions where the distance between them is short, and the floating support means A2 may be provided at a position where the distance from each fixing means A1 is long. Further, the number of floating support means A2 is not limited to a plurality, and may be one.

  In the stereo camera device 1, the fixing means A <b> 1 is disposed on the left side of the front part of the substrate housing 31. In the vicinity of the front left portion of the substrate housing portion 31, many heat generating components 42 of the substrate 4 are arranged, and this is a region in the substrate 4 that tends to be relatively hot. Thus, by providing the fixing means A1 in the high temperature region, the heat of the substrate 4 can be transmitted from the fixing screw 51 to the boss 34A, and can be dissipated to the entire housing 3, thereby improving the cooling performance of the substrate 4. it can.

  Further, as shown in FIG. 6, the upper surface portion 31 a of the housing 3 is provided with a convex portion 31 c serving as a heat sink at a position corresponding to the heat generating component 42, so that the clearance with the substrate 4 is narrower than the others. ing. Therefore, by disposing the fixing means A1 in the high temperature region, the clearance between the convex portion 31c and the substrate 4 can be kept constant, and stable heat dissipation performance can be ensured.

  A connector 43 is disposed on the left rear of the substrate 4. When inserting / removing the communication cable to / from the connector 43, a force in the front-rear direction acts on the substrate 4, but the fixing means A1 is disposed on the left side of the front of the substrate accommodating portion 31 and faces the insertion / removal direction of the connector 43. Therefore, the force acting in the front-rear direction can be received by the fixing means A1, and the movement of the substrate 4 due to the force can be suppressed. Further, since the position of the substrate 4 is positioned by the fixing means A1, the connector 43 can be always disposed at a position facing the opening hole 31d of the substrate housing portion 31, and a product with high assembly accuracy and quality is provided. be able to.

  The fixing means A1 is disposed near the center between the left and right imaging units 2R, 2L, whereas the floating support means A2 is located on one side of the left and right imaging units 2R, 2L rather than the fixing means A1. It is located at a close position. Thus, by providing the fixing means A1 at a position closer to the center in the longitudinal direction than the longitudinal end portion of the housing 3, the distance to the end portion of the substrate body 41 is shortened as much as possible, and the housing 3 extends due to thermal expansion. The distance can be shortened. Accordingly, the gap in which the substrate main body 41 and the housing 3 are relatively movable in the sliding direction formed between the thick shaft portion 63 of the stepped screw 61 and the through hole 41b of the substrate main body 41 is further reduced. Can do.

  The fixing means A1 may be arranged in a place where the noise of the substrate 4 is likely to be generated and actively grounded. Noise generated in the substrate 4 can be released from the fixing screw 51 of the fixing means A1 to the housing 3, and the influence of noise can be suppressed.

  In the above-described embodiment, the case of the stereo camera device 1 has been described as an example. However, the stereo camera device 1 can be applied to a camera device having one or three or more image capturing units. Axis misalignment and setting changes in the geometric system with the vehicle can be prevented.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

1 Stereo camera device (camera device)
2R, 2L Image pickup unit 3 Housing 4 Substrate 43 Connector 51 Fixing screw A1 Fixing means A2 Floating support means M Vehicle

Claims (6)

A structure for holding a substrate in a housing,
At least one fixing means for fixing the substrate to the housing;
At least one floating support means for supporting the substrate on the housing so as to move in a direction approaching and separating from a fixing point fixed by the fixing means;
A substrate holding structure comprising:   The substrate holding structure according to claim 1, wherein the fixing unit includes a fixing screw for fastening the substrate to the housing. A camera device in which a substrate is attached to a housing having an imaging unit,
At least one fixing means for fixing the substrate to the housing;
At least one floating support means for supporting the substrate on the housing so as to move in a direction approaching and separating from a fixing point fixed by the fixing means;
A camera device comprising: The imaging unit is provided in a pair on the left and right,
The camera device according to claim 3, wherein the substrate is disposed between the left and right imaging units. The fixing means is disposed at a position near the center between the left and right imaging units,
The camera apparatus according to claim 4, wherein the floating support unit is disposed at a position closer to one side of the left and right imaging units than the fixing unit. The substrate has a connector;
The camera apparatus according to claim 4, wherein the fixing unit is disposed at a position facing the connector insertion / removal direction.

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