JP6258109B2 - Automotive electronics - Google Patents

Description

  The present invention relates to an in-vehicle electronic device such as a display device that is used by being installed on an installation base material such as an instrument panel of a vehicle.

  When in-vehicle electronic devices such as display devices and car audio devices are installed on a vehicle base material (for example, an instrument panel), a metal bracket (mounting bracket) is screwed or caulked to the main body of the in-vehicle electronic device. A method of attaching using a fixing means such as, and fixing to a predetermined position of the installation base material via the bracket is widely adopted (see, for example, Patent Document 1). Here, the installation location of the equipment body and bracket must have high rigidity and fastening strength to withstand vibration and impact from the vehicle, and the bracket can be easily and firmly attached to the equipment body. Is desired.

  As a conventional technology that meets such demands, the mounting surface on the device body side is made of a highly rigid metal plate or the like, and a plurality of screw holes are formed on the mounting surface, and the other bracket is compatible with the screw holes. An attachment structure in which a plurality of through holes are formed and a plurality of screw members are inserted into the through holes from the outside of the bracket and screwed into the screw holes, thereby firmly attaching the bracket to a predetermined position of the device body. Are known.

JP 2002-29319 A

  However, in the above-described conventional technique in which the bracket is attached to the device main body using the screw member, the attachment surface on the device main body side to which the bracket is screwed needs to be formed by a thick and heavy metal plate having a high rigidity. For this reason, there is a problem in that it is difficult to reduce the weight and thickness of the entire electronic device. In particular, in the case of an in-vehicle electronic device in which the back side of the device body is covered with a metal cover having an electromagnetic shielding function, a bracket is attached to the metal cover. It is necessary to make the plate thickness and shape that can withstand, and this has been a major factor that hinders weight reduction and thinning of the entire electronic device.

  In addition, when the bracket is attached to the equipment body using a screw member, the fastening force in the radial direction (in-plane direction of the mounting surface) is weaker than the thrust direction (tightening direction) of the screw member. If the number is not increased, the bracket cannot be firmly attached, and there is a problem that the bracket must be enlarged as the number of screwing points increases.

  The present invention has been made in view of the actual situation of the prior art, and the object thereof is to be able to firmly attach the bracket to the apparatus body using a small number of screw members, and is also suitable for reduction in thickness and weight. Is to provide an in-vehicle electronic device.

  In order to achieve the above object, according to the present invention, an apparatus main body including a base member and a metal cover covering the base member is fixed to an installation base material of a vehicle via a bracket attached to the metal cover. In the in-vehicle electronic device, a frustoconical protrusion is formed on the bracket, a frustoconical recess is formed in the metal cover, and the bottom peripheral edge of the protrusion is The screw member is configured to pass through the bottom surface of the protruding portion and the inner bottom surface of the recessed portion and be fastened to the base member in a state of being in contact with the inclined surface of the recessed portion.

  In the on-vehicle electronic device configured as described above, the frustoconical protrusion is formed on the bracket, and the frustoconical recess is formed on the metal cover that covers the apparatus body. Since the screw member that penetrates the bottom surface and the inner bottom surface of the recessed portion is fastened to the base member on the equipment body side, the metal cover is only sandwiched between the bracket and the base member, and the screw member is tightened to the metal cover. High rigidity to receive force is unnecessary. In addition, since the bracket is reliably positioned in the plane direction with respect to the metal cover by bringing the bottom peripheral edge of the protrusion into contact with the inclined surface of the recess by the concave-convex fitting of the recess and the protrusion, the screw member Even if the tightening force is weak, the bracket will not be displaced. Therefore, the screw member can be constituted by a small-diameter screw having a weak fastening force, and the base member to which the screw member is fastened is not required to have high rigidity. It can be formed of a synthetic resin. Further, since a clearance is secured between the bottom surface of the protrusion and the inner bottom surface of the recessed portion, the recessed portion of the metal cover serves as a spring washer when the screw member is tightened, and a separate spring washer is used. The loosening of the screw member can be prevented without adding. This makes it possible to reduce the thickness and weight of the entire electronic device by using a thin metal cover and base member, and to attach the bracket firmly to the device body using a small number of screw members without rattling. Can do.

  In the above configuration, the protruding portion of the bracket and the recessed portion of the metal cover are both formed by drawing a metal plate, so that the drawing angle of the recessed portion is less than the drawing angle of the protruding portion. When set, and the diameter of the inner bottom surface of the recessed portion is set to be smaller than the diameter of the bottom surface of the projecting portion, the bottom surface of the projecting portion can be surely adhered to the inner bottom surface of the recessed portion. It is preferable that the amount of clearance generated between the bottom surface of the protruding portion and the inner bottom surface of the recessed portion can be set intentionally by contacting the inclined surface of the recessed portion.

  Further, in the above configuration, when a circuit board facing the metal cover is housed inside the device main body, the circuit board is sandwiched between the recessed portion of the metal cover and the base member by the screw member. The three members of the bracket, the metal cover, and the circuit board are fastened together with the screw member, which is preferable because the load applied to the circuit board can be suppressed by the spring washer function of the recessed portion.

  Further, in the above configuration, two sets of position restricting portions each including a pair of protruding portion and recessed portion are provided, and one of the pair of recessed portions provided in the position restricting portion is provided. If the opening end of the part is set to be elliptical, the peripheral edge of the bottom surface of the projecting part is in contact with the entire circumference of the inclined surface of the recessed part in the position restricting part in one set, and the bottom surface of the projecting part in the other part of the position restricting part Since the peripheral edge abuts on the inclined surface along the minor axis direction of the recessed portion, the bracket is position-regulated in the rotational direction by the position-regulating portion of the other set with reference to the position-regulating portion of one set. Using the screw member, the bracket can be firmly attached to a predetermined position of the device main body without rattling.

  According to the in-vehicle electronic device of the present invention, it is possible to reduce the thickness and weight of the entire electronic device by using a thin metal cover, and to loosen the bracket to the device body using a small number of screw members. And can be attached firmly.

It is a perspective view of the vehicle-mounted electronic device which concerns on the example of embodiment of this invention. It is a rear view of this vehicle-mounted electronic device. It is a disassembled perspective view of this vehicle-mounted electronic device. It is the disassembled perspective view which looked at the principal part of this vehicle-mounted electronic device from the back side. It is a rear view of the metal cover with which this vehicle-mounted electronic device is equipped. It is sectional drawing which follows the VI-VI line of FIG.

  An embodiment of the invention will be described with reference to the drawings. An in-vehicle electronic device 1 according to an embodiment of the present invention is used by being installed on an installation base material (not shown) such as an instrument panel of a vehicle. 1 to 6, the in-vehicle electronic device 1 includes a frame-shaped main body 2 having a rectangular opening 2 a and a base member attached to the back surface of the frame-shaped main body 2. A chassis base 3, a display unit 4 comprising an LCD or the like held on the front surface of the chassis base 3 and having the display unit 4a exposed from the opening 2a, and a frame-shaped main body so as to cover the display unit 4a of the display unit 4 1, a transparent plate 5 attached to the front surface of the circuit board 1, a circuit board 6 held on the back surface of the chassis base 3, a metal cover 7 attached to the back surface of the chassis base 3 so as to cover the circuit board 6, and a metal cover 7 And a bracket 8 or the like attached to the surface. Each member excluding the bracket 8 constitutes an apparatus main body, and the apparatus main body is fixed to the above-described installation base material via the bracket 8.

  The chassis base 3 is formed by pressing a metal plate having a relatively thin plate thickness (for example, a plate thickness of 0.8 mm). The chassis base 3 is formed with a large number of rib-like protrusions 3a in order to increase rigidity. . As shown in FIG. 4, on the back surface of the chassis base 3, there are formed three frustoconical support protrusions 3b and a support protrusion 3c having a smaller diameter than the support protrusions 3b, and the central portions of the support protrusions 3b and 3c. A screw hole 3d is engraved in. The circuit board 6 has four through holes 6a. With the circuit board 6 mounted on the support protrusions 3b and 3c, a screw member (not shown) is inserted into one through hole 6a. The circuit board 6 is directly screwed to the chassis base 3 at this location by being fastened to the screw hole 3d of the small-diameter support protrusion 3c. The circuit board 6 is screwed to the remaining three support protrusions 3b using another screw member, which will be described in detail later.

  The metal cover 7 is made of a thin metal plate (for example, a plate thickness of 0.6 mm), and the metal cover 7 is an electromagnetic shield function for blocking leakage / intrusion of unnecessary electromagnetic waves radiated from the circuit board 6 and external electromagnetic waves. have. The metal cover 7 includes a box-shaped covering portion 7a that is slightly larger than the outer shape of the circuit board 6, and a mounting plate portion 7b that bends at right angles from opposite lower sides of the covering portion 7a. The four corners of the portion 7b are fixed to the back surface of the chassis base 3 using screw members 9 (see FIG. 2). The covering portion 7a includes three recessed portions 10, 11, 12 protruding in a truncated cone shape toward the circuit board 6, and two pedestal portions 13 protruding in the opposite direction to the recessed portions 10, 11, 12 In the following description, for the sake of convenience, the three recessed portions 10, 11, and 12 will be referred to as first to third recessed portions.

  Through holes 10 a, 11 a, 12 a are formed on the inner bottom surfaces of the first to third recessed portions 10, 11, 12, and the screw member 14 is connected to the through hole 12 a of the third recessed portion 12 and the circuit board 6. Then, the circuit board 6 and the metal cover 7 are fastened together with the chassis base 3 at the corresponding locations by being inserted into the through holes 6a and fastened to the screw holes 3d of the corresponding support protrusions 3b. On the other hand, the first recessed portion 10 and the second recessed portion 11 function as a position restricting portion of the bracket 8, and the aperture angles of the inclined surfaces of the first and second recessed portions 10 and 11 are the same. However, the inner bottom surface and the opening end of the first recessed portion 10 are circular, whereas the inner bottom surface and the opening end of the second recessed portion 11 are set to be elliptical. That is, as shown in FIG. 5, if the straight line connecting the through holes 10a, 11a of the first and second recessed portions 10, 11 is P, the inner bottom surface and the open end of the second recessed portion 11 are straight lines P. The major axis is the direction along the axis and the minor axis is the direction along the straight line Q orthogonal thereto.

  The bracket 8 is made of a relatively thick metal plate having a rigidity higher than that of the metal cover 7 (for example, a plate thickness of 1.0 mm). The bracket 8 includes a connecting plate portion 8a facing the covering portion 7a of the metal cover 7, and a connecting portion. A pair of mounting leg pieces 8b projecting in a crank shape from the plate portion 8a is formed. A pair of frustoconical protrusions 15 are formed on the connecting plate part 8 a by drawing, and through holes 15 a are formed on the bottom surfaces of the protrusions 15. Although the aperture angles of both protrusions 15 are the same, as shown in FIG. 6, the aperture angles of the first and second recessed portions 10 and 11 are made looser than the aperture angles of both protrusions 15, that is, The rising angle of the inclined surface with respect to the inner bottom surfaces of the first and second recessed portions 10 and 11 is set to be smaller than the rising angle of the inclined surfaces with respect to the bottom surfaces of both protrusions 15. Thus, by making the aperture angles of the first and second recessed portions 10 and 11 and the protruding portion 15 different, the peripheral edge of the bottom surface of the protruding portion 15 comes into contact with the inclined surface of the corresponding recessed portions 10 and 11. It has become. Further, the diameters of the flat inner bottom surfaces of the first and second recessed portions 10 and 11 (the diameter in the minor axis direction along the straight line Q in the second recessed portion 11) are The diameter is set to be smaller than the diameter, and a rounded surface process (curved surface process) is performed on the peripheral edge of the bottom surface of the protrusion 15. The diameter of the circular flat surface of the support protrusion 3b of the chassis base 3 is set to be larger than the diameter of the inner bottom surfaces of the first and second recessed portions 10 and 11.

  The procedure for attaching the bracket 8 to the apparatus main body will be described. After the circuit board 6 is directly screwed to the back surface of the chassis base 3 attached to the frame-like main body 2 using a screw member (not shown), the circuit board 6 and the chassis are fixed. In a state where the metal cover 7 is overlapped on the back surface of the chassis base 3 so as to cover the base 3, the mounting plate portion 7b is used by using three screw members 9 (the remaining three members excluding the lower right screw member 9 in FIG. 2). Is screwed to the back surface of the chassis base 3, and another screw member 14 is inserted into the through hole 12 a of the third recessed portion 12 to fasten the metal cover 7 and the circuit board 6 together with the chassis base 3.

  Next, both projecting portions 15 of the bracket 8 are inserted into the first and second recessed portions 10 and 11 of the metal cover 7, and the screw members 16 inserted into the through holes 15 a of these projecting portions 15 are first and The circuit board 6 and the metal cover 7 are inserted by passing through the through holes 10a, 11a of the second recessed parts 10, 11 and the through holes 6a of the circuit board 6 and tightening to the corresponding screw holes 3d of the support protrusions 3b. The bracket 8 is screwed to the chassis base 3 with the pinch interposed therebetween. Here, the diameter of the flat surface of the support protrusion 3b of the chassis base 3 is larger than the diameter of the inner bottom surface of the first and second recessed portions 10, 11, that is, the first and second recessed portions. Since the diameter is set to be different from the diameters of the inner bottom surfaces of 10 and 11, for example, even when vibration is applied to the circuit board 6 in the vertical direction in FIG. It is possible to prevent bending stress from concentrating on the contact portion with the outer peripheral edge.

  At that time, the clearance between the bottom surface of the protrusion 15 and the inner bottom surface of the recesses 10, 11 is caused by the peripheral edge of the bottom surface of the protrusion 15 contacting the inclined surfaces of the first and second recesses 10, 11. Therefore, when the screw member 16 is tightened, the first and second recessed portions 10 and 11 of the metal cover 7 serve as a spring washer, and the screw member 16 is loosened without adding a separate spring washer. It is possible to prevent a local load from being applied to the circuit board 6. Further, the diameter of the inner bottom surfaces of the first and second recessed portions 10 and 11 is set to be smaller than the diameters of the bottom surfaces of both projecting portions 15, and a rounded process is applied to the bottom peripheral edge portions of the projecting portions 15. Therefore, the bottom surface of the projecting portion 15 does not adhere to the inner bottom surfaces of the first and second recessed portions 10 and 11, and the amount of the projecting portion 15 entering the recessed portions 10 and 11 is intentionally set. The amount of clearance can be adjusted.

  Further, of the first and second recessed portions 10 and 11 that are concavo-convexly engaged with the pair of projecting portions 15, the opening end of the first recessed portion 10 is circular, whereas the second recessed portion 11. Since the opening end of the first protrusion 15 is set in an elliptical shape, the one protrusion 15 abuts the entire circumference of the inclined surface of the first recess 10 by line contact, and the other protrusion 15 corresponds to the second recess 11. Only the inclined surface along the minor axis direction comes into contact with the two points on both sides of the through hole 11a. As a result, the position of the bracket 8 is restricted in all directions on the plane with respect to the position restricting portion (line contact portion) on the first recessed portion 10 side, and the position restricting portion (point contact portion) on the second recessed portion 11 side. Therefore, even if a slight dimensional error occurs in the metal cover 7 or the bracket 8, the two screw members 16 are used. Thus, the bracket 8 can be firmly attached to a predetermined position of the device main body without rattling.

  Then, before and after the screwing operation, by using another screw member 9, the peripheral portion of the bracket 8 and the mounting plate portion 7 b of the metal cover 7 are fastened to the back surface of the chassis base 3, so that one bracket 8 is provided. The screw member 9 and the two screw members 16 are used to be stably fixed to the apparatus body (see FIG. 2). The vehicle-mounted electronic device 1 having the bracket 8 attached to the device body in this manner is fixed to a predetermined position of the vehicle by screwing the mounting leg piece 8b of the bracket 8 to an installation base material such as an instrument panel. In this case, the base part 13 of the metal cover 7 and the connecting plate part 8a of the bracket 8 are set on substantially the same surface, so that the in-vehicle electronic device 1 can be stably pressed against the flat surface of the installation base material. It can be done.

  As described above, in the in-vehicle electronic device 1 according to this embodiment, the conical recesses 10 and 11 are formed in the metal cover 7 that forms the outer shell of the device body, and the device body The bracket 8 to be attached is formed with a truncated cone-shaped protruding portion 15, and a screw member 16 penetrating the bottom surface of the protruding portion 15 and the inner bottom surfaces of the recessed portions 10 and 11 is fastened to the chassis base 3 on the apparatus main body side. Therefore, the metal cover 7 is only sandwiched between the bracket 8 and the chassis base 3, and high rigidity for receiving the tightening force of the screw member 16 on the metal cover 7 is not necessary. Further, the bracket 8 is in a planar direction with respect to the metal cover 7 by bringing the bottom peripheral edge portion of the protrusion 15 into contact with the inclined surface of the recesses 10 and 11 by fitting the concave and convex portions 10 and 11 and the protrusion 15 to each other. Since the position is reliably regulated in the vertical and horizontal directions in FIG. 2, the bracket 8 is not displaced even if the tightening force of the screw member 16 is weak. Therefore, the screw member 16 can be constituted by a small diameter screw (for example, M2.6 screw) having a weak tightening force, and the chassis base 3 to which the screw member 16 is fastened is not required to have high rigidity. The chassis base 3 can be formed of a thin metal plate or synthetic resin. Further, since a clearance is secured between the bottom surface of the protruding portion 15 and the inner bottom surfaces of the recessed portions 10 and 11, the recessed portions 10 and 11 of the metal cover 7 serve as a spring washer when the screw member 16 is tightened. Thus, loosening of the screw member 16 can be prevented without adding a separate spring washer. As described above, it is possible to reduce the thickness and weight of the entire electronic device 1 by using the thin metal cover 7 and the chassis base 3, and to attach the bracket 8 to the device by using a small diameter and a small number of screw members 16. Can be firmly attached to the main body without rattling.

  In addition, the protruding portion 15 of the bracket 8 and the recessed portions 10 and 11 of the metal cover 7 are both formed by drawing a metal plate, and the drawing angle of the recessed portions 10 and 11 is the restriction of the protruding portion 15. It is set so as to be looser than the angle, and the diameter of the inner bottom surface of the recessed portions 10, 11 is set to be smaller than the diameter of the bottom surface of the projecting portion 15, and further on the peripheral edge of the bottom surface of the projecting portion 15 Since the rounding is applied, the bottom surface of the protruding portion 15 does not adhere to the inner bottom surface of the recessed portions 10 and 11, and the clearance generated between the bottom surface of the protruding portion 15 and the inner bottom surface of the recessed portions 10 and 11. The amount can be set intentionally, and a stable spring washer function can be imparted to the recessed portions 10 and 11 of the metal cover 7. The rounding process performed on the peripheral edge of the bottom surface of the projecting portion 15 is mainly for improving the slidability with the inclined surfaces of the recessed portions 10 and 11, but does not consider such slidability. In this case, it is possible to save the R-process.

  In addition, a circuit board 6 covered with a metal cover 7 is accommodated inside the apparatus body, and the circuit board 6 is sandwiched between the recessed portions 10 and 11 of the metal cover 7 and the chassis base 3 by a screw member 16. Therefore, the three members of the bracket 8, the metal cover 7 and the circuit board 6 are fastened together with the screw member 16, but the load applied to the circuit board 6 is suppressed by the spring washer function of the recessed portions 10 and 11. can do.

  Moreover, two sets of position restricting portions, each of which includes a pair of the protruding portion 15 and the recessed portions 10 and 11, are provided, of which the opening end of the first recessed portion 10 is circular, whereas the second Since the opening end of the recessed portion 11 is set to be elliptical, the peripheral edge of the bottom surface of the projecting portion 15 abuts the entire circumference of the inclined surface of the first recessed portion 10 in one set of position restricting portions, and the other set In the position restricting portion, the peripheral edge of the bottom surface of the protruding portion 15 contacts only the inclined surface along the minor axis direction of the second recessed portion 11. As a result, the bracket 8 rotates around the center of the first recessed portion 10 with the other pair of position restricting portions (second recessed portion 11 side) on the basis of one set of position restricting portions (first recessed portion 10 side). The position is restricted in the rotational direction around the center, and the bracket 8 can be firmly attached to a predetermined position of the device body using the two screw members 16 without rattling.

  Note that the shape of the first and second recessed portions 10 and 11 is not limited to the above embodiment example. For example, three protrusions (or three protrusions) are provided at an interval of 120 degrees on the inclined surface of one recessed portion. Various modifications can be employed, such as forming protrusions), forming minute protrusions on the entire inclined surface of the recessed portion, and making the inclined surface of the recessed portion a multistage stop.

  Further, in the above-described embodiment, the opening end of the first recessed portion 10 is made circular and the opening end of the second recessed portion 11 is made elliptical, whereby the bracket 8 is replaced with the first recessed portion 10. The position restricting portion of the projecting portion 15 is regulated in all directions in the plane, and the position restricting portion of the second recessed portion 11 and the projecting portion 15 is restricted in the rotational direction. Thus, the position of the bracket 8 can be restricted on the XY plane. For example, if the opening end of the first recess is an ellipse whose minor axis is the X direction, and the opening end of the second recess is an ellipse whose minor axis is the Y direction, It is possible to regulate in the Y direction on the second concave portion side while regulating in the X direction on the first concave portion side.

DESCRIPTION OF SYMBOLS 1 Vehicle-mounted electronic device 2 Frame-shaped main body 3 Chassis base (base member)
3b, 3c Support projection 3d Screw hole 6 Circuit board 6a Through hole 7 Metal cover 7a Cover 7b Mounting plate 8 Bracket 8a Connection plate 8b Mounting leg 10 First recess 11 Second recess 12 3rd Recessed portion 10a, 11a, 12a through hole 15 projecting portion 15a through hole 16 screw member

Claims (4)

In an in-vehicle electronic device in which a device body including a base member and a metal cover that covers the base member is fixed to an installation base material of a vehicle via a bracket attached to the metal cover,
A frustoconical protrusion is formed on the bracket, a frustoconical recess is formed on the metal cover, and the bottom peripheral edge of the protrusion is an inclined surface of the recess. The in-vehicle electronic device, wherein the screw member passes through the bottom surface of the projecting portion and the inner bottom surface of the recessed portion and is fastened to the base member in a contact state.   2. The projection according to claim 1, wherein both the protrusion and the recess are formed by drawing a metal plate, and the aperture angle of the recess is less than the aperture angle of the protrusion. And the diameter of the inner bottom surface of the recessed portion is set to be smaller than the diameter of the bottom surface of the protruding portion.   3. The circuit board according to claim 1, wherein a circuit board facing the metal cover is accommodated in the device main body, and the circuit board is formed by the screw member between the recessed portion of the metal cover and the base member. An in-vehicle electronic device characterized by being sandwiched between them. The description of any one of claims 1 to 3 is provided with two sets of position restricting portions each including a pair of the projecting portion and the recessed portion, and the pair of the position restricting portions provided in the position restricting portions. An in-vehicle electronic device, wherein an opening end of any one of the recessed portions is set to be elliptical.