JP6630774B2 - Fixed structure - Google Patents

Description

  The present invention relates to a technique of a fixing structure for fixing a case and a cover.

  2. Description of the Related Art Conventionally, there has been known a fixing structure in which a metal case containing a circuit board or the like is covered with a cover and fixed to protect the circuit board from impact or the like.

  In such a fixing structure, the case and the cover are fixed by providing an inverted “L” -shaped engaging claw on the cover and engaging with a claw receiving portion of the case. When the engaging claw is engaged with the claw receiving portion, the engaging claw is bent to generate a reaction force, thereby preventing loosening of the fixing and preventing rattling between the case and the cover.

  For example, Patent Literature 1 discloses a technique in which engagement claws provided on both side surfaces of a cover are engaged with claw receiving portions of a case to fix the case and the cover.

JP 2010-52715 A

  However, when an inverted "L" -shaped engaging claw is used, when the engaging claw is bent, pressure concentrates on the root portion of the engaging claw, and the engaging claw may be broken. If the engaging claw is broken, the fixation between the case and the cover is loosened, which causes rattling.

  The present invention has been made in view of the above problems, and has as its object to provide a technique for firmly fixing a case and a cover without easily breaking even if an engaging claw is bent.

In order to solve the above problems, the invention according to claim 1 is a fixing structure for fixing a case having an opening surface and a cover covering the opening surface, wherein an engaging claw provided on the cover, A claw receiving piece provided on a side surface and engaging with the engaging claw, wherein the engaging claw has a first claw portion, a second claw portion, a connecting portion, two pieces each, and a connecting portion. and, the lower end portion of the first hook portion is fixed to the cover, will open end lower end is not fixed to the cover of the second hook portion, the second hook portion is the first hook portions The first claw portion and the second claw portion are formed such that the engagement claw is bent in a substantially U-shape that is folded back and elastically deformed on the upper surface side of the cover . connect the upper end of a two claw portions provided at a position lower than the upper surface of the cover, it said coupling portion 2 of the second hook portion Connecting the vicinity of the open end, the first pawl portion, the second hook portion, and a one by two pieces of the connecting portion, the inside of said connecting part surrounds becomes open.

According to a second aspect of the present invention, in the fixing structure according to the first aspect, a lower end portion of the first claw portion is provided so as to be disposed in a concave portion on a side surface of the cover.

  According to a third aspect of the present invention, in the fixing structure according to the first or second aspect, the substantially U-shape of the engaging claw is a curved shape.

  According to the first to third aspects of the present invention, the engaging claw is formed lower than the upper surface of the cover, so that even if the object collides with the upper surface, the object does not come into contact with the engaging claw, and The ingrown nail does not come off the nail receiving piece. Then, the case and the cover can be firmly fixed.

FIG. 1 is an exploded perspective view showing an outline of a fixing structure according to the present embodiment. FIG. 2 is a perspective view showing the configuration of the engagement claw. FIG. 3 is a cross-sectional view showing a state in which the engagement claws are engaged with the claw receiving pieces. FIG. 4 is a cross-sectional view showing a state in which the engagement claws engage with the claw receiving pieces. FIG. 5 is a cross-sectional view showing a state in which the engagement claws engage with the claw receiving pieces. FIG. 6 is a cross-sectional view illustrating another example of the engagement claw. FIG. 7 is a cross-sectional view illustrating another example of the engagement claw.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  <1. First Embodiment>

    <1-1. Overview>

  FIG. 1 is an exploded perspective view showing an outline of a fixing structure for fixing the case 1 and the cover 2. The case 1 and the cover 2 are fixed to each other to form a housing 3 having a circuit board 14 built therein. The housing 3 is connected to a control target via a connector opening CA through a connector, and functions as an electronic control device. The housing 3 is fixed inside a vehicle such as an automobile with a bracket BR or the like, and controls a power steering, an airbag, a fuel injection valve of an internal combustion engine, and the like.

  In the following description, directions and directions are shown based on the three-dimensional orthogonal coordinate system shown in FIG. The rectangular coordinate system is fixed relatively to the housing 3 (the case 1 and the cover 2). The X direction is the back side of the housing 3 (the side from the outside of the housing 3 to the connector opening), the Y direction is the left side of the housing 3 (the left side toward the connector opening CA), and the Z direction is the housing 3. Shows the upper side. In the following description, the terms front and rear, left and right, and up and down are based on the example of FIG.

  The case 1 is a box-shaped metal die-cast having an opening surface. The metal material is preferably aluminum die-cast. For example, the ADC 12. Aluminum die-casting is excellent in machinability, castability, flowability, and availability.

  The case 1 includes a substantially rectangular bottom surface BA, two side surfaces SA1 (a surface substantially perpendicular to the opening surface) substantially perpendicular to the bottom surface BA, a back surface RA1, and a bracket BR. The case 1 incorporates and protects a circuit board 14 on which an electronic component 13 is mounted in a stepped portion 12 formed stepwise from the bottom surface BA. By bringing the circuit board 14 close to the metal case 1, the heat generated by the circuit board 14 can be radiated through the case 1. Further, by separately fixing the circuit board using the screw holes 15 formed at the four inner corners of the case 1, electronic parts and the circuit board can be easily treated using the wide opening surface.

  The surface on the opposite side of the back surface RA1 becomes the connector opening CA. In the connector opening CA, a connector (not shown) serving as an input / output unit with a control target is installed.

  The case 1 includes two claw receiving pieces 11 on each of the two side surfaces SA1. The nail receiving piece 11 is formed to protrude outward from the side surface SA1, the upper surface is formed obliquely downward from the side surface SA1 side, and the lower surface is formed in a plane (parallel to the bottom surface BA).

  The cover 2 has a substantially rectangular shape so as to close the opening surface of the case 1 and is formed of a resin such as PP (polypropylene). The cover 2 includes an upper surface UA (principal surface) that covers the opening surface of the case 1 from above (the first direction in the Z direction), and a side surface that extends from the outer peripheral portion of the upper surface UA to the side surface SA1 and the inner surface RA1 of the case 1. SA2 and a back surface RA2 are provided. The surface on the opposite side of the back surface RA2 becomes the connector opening CA.

  In the following drawings, the scale of each component may be appropriately changed and shown in order to make each component recognizable.

    <1-2. Configuration>

  FIG. 2 is a perspective view illustrating a configuration of the engagement claw 21 provided on the cover 2. Two engaging claws 21 are integrally provided on both side surfaces SA2 of the cover 2 and engage with the claw receiving pieces 11 of the case 1 to generate an urging force, thereby firmly fixing the case 1 and the cover 2. I do. That is, when the engaging claw 21 and the claw receiving piece 11 are engaged with each other, the engaging claw 21 is elastically deformed, and the vicinity of the open end serving as the tip of the engaging claw 21 raises the claw receiving piece 11 upward (+ Z side. (1st side). The engagement claw 21 includes a first claw portion 21a, a second claw portion 21b, a connection portion 21c, and a connection portion 21d. In addition, the engagement claw 21 includes two pieces of a first claw portion 21a, a second claw portion 21b, and a connection portion 21c.

  The first claw portion 21 a has a lower end portion (−Z side / second side) fixed to the cover 2, and is formed to extend substantially orthogonally (+ Z side) to the opening surface of the case 1.

  The second claw portion 21b is an open end whose lower end (-Z side / second side) is not fixed to the cover 2, and is formed to extend substantially parallel to the first claw portion 21a.

  The connection part 21c is formed so as to connect the upper ends (+ Z side) of the first claw part 21a and the second claw part 21b. The upper surface of the connection portion 21c is a flat surface, and the upper surface is pressed by a pressing person. In addition, the connection portion 21c is disposed below (−Z side / second side) below the upper surface UA (main surface). That is, the engaging claw 21 does not protrude above the upper surface UA (+ Z side).

  The connecting portion 21d connects the vicinity of the open ends of the two second claw portions 21b. The inside surrounded by the two pieces of the first claw portion 21a, the second claw portion 21b, the connection portion 21c, and the connection portion 21d is an opening 21e. The upper surface (the surface on the + Z side) between the second claws 21b of the connecting portion 21d is the inside 21f of the opening 21e. When the inside 21f of the opening 21e is engaged with (engaged with) the bottom surface of the claw receiving piece 11, the engaging claw 21 and the claw receiving piece 11 are engaged. When the engaging claw 21 and the claw receiving piece 11 are engaged with each other, the engaging claw 21 is elastically deformed, and the reaction force causes the inner side 21f of the opening 21e to move the claw receiving piece 11 upward (+ Z side / first side). Energize. The case 1 and the cover 2 are firmly fixed by this urging force. The reason why the engaging claw 21 is elastically deformed is that the connecting portion 21c is pressed by the presser from above (+ Z side / first side).

  The side surface (the surface in the X-axis direction) of the first claw portion 21a, the second claw portion 21b, and the connection portion 21c (that is, the side shape of the engagement claw 21) is indicated by a substantially center line I of the side surface of each portion. In addition, it has a deformed "U" shape. By forming the engaging claw 21 in a U-shape, a plurality of elastically deformable portions can be provided, and the entire portion can be bent when pressed. That is, since the engagement claw 21 has the first claw portion 21a, the second claw portion 21b, and the connection portion 21c, elastic deformation becomes easy as a whole. Thereby, the engaging claw 21 can be configured to be harder to break as compared with the inverted “L” -shaped engaging claw.

  The cover 2 has a concave portion 2a on the side surface SA2. The lower (−Z side / second side) end of the first claw 21a is fixed to the bottom surface (−Z side / second side surface) inside the recess 2a. By providing the first claw portion 21a in the recess 2a, the engagement claw 21 can be formed lower than the upper surface UA of the cover 2. Accordingly, by forming the first claw portion 21a lower than the upper surface UA, even if an object collides with the upper surface UA, the object does not contact the engaging claw 21 and the engaging claw 21 It does not come off from the receiving piece 11. Further, when the first claw portion 21a is provided in the concave portion 2a, the distance between the second claw portion 21b and the claw receiving piece 11 can be reduced. For this reason, it is not necessary to form the second claw portion 21 b long, and the engagement claw 21 can be hardly disengaged from the claw receiving piece 11.

  Next, the dimensions of each part of the engagement claw 21 will be described. However, the following numerical values are examples, and the dimensions of the engagement claws 21 are not limited to the respective numerical values.

  The length (Z-axis direction) A of the first claw portion 21a is 6.0 [mm]. The length (Z-axis direction) B of the engaging claw 21 is 16 [mm]. The width (X-axis direction) C of the engaging claw 21 is 14 [mm]. The thickness (Y-axis direction) D of the engagement claw 21 is 1.2 [mm]. The length (Z-axis direction) E of the connecting portion 21d is 3.5 [mm]. The length (Y-axis direction) F of the connection portion 21c is 4.0 [mm]. The width G (X-axis direction) of the connection portion 21c is 3.5 [mm]. The distance H between the connection portion 21c and the top surface of the cover 2 is 4.0 [mm].

    <1-3. Engage>

  3 to 5 show the manner in which the engaging claw 21 engages with the claw receiving piece 11 in time series. 3 to 5 and other cross-sectional views correspond to the cross-sectional views taken along the line S-S in FIG. For convenience of explanation, a claw receiving piece 11 not included in the cross-sectional view is indicated by a dotted line.

  FIG. 3 shows a state where the cover 2 is arranged on the case 1. From this state, the cover 2 placed on the case 1 is moved downward (-Z), and the cover 2 is fitted to the case 1. At this time, the claw receiving piece 11 is inserted between the side surface of the cover 2 and the engagement claw 21.

  FIG. 4 shows a state in which the cover 2 is fitted to the case 1 and the engagement claws 21 are not engaged with the claw receiving pieces 11. When the cover 2 is moved downward from the state where the cover 2 is disposed on the case 1, the open end of the second claw portion 21 b of the engagement claw 21 comes into contact with the claw receiving piece 11 of the case 1. Further, when the cover 2 is moved downward, the engagement claws 21 (the first claw portions 21a, the second claw portions 21b, and the connection portions 21c) are elastically deformed (bent) according to the shape of the claw receiving pieces 11. I do. That is, the first claw portion 21a is slightly deformed toward the cover 2 (+ Y side), the second claw portion 21b is deformed toward the outside of the case 1 (−Y side), and the connection portion 21c is slightly upward (+ Z side). Deform to. In this state, the inside 21f of the opening 21e near the open end of the engaging claw 21 is slightly above (+ Z side) the bottom surface 11a of the claw receiving piece 11 (the -Z side surface of the claw receiving piece 11). It is. Therefore, the engaging claw 21 is stationary in a state where the inside 21f of the opening 21e is hooked on the claw receiving piece 11 and is elastically deformed. In this state, when the upper surface of the connecting portion 21c is pressed downward with a predetermined pressing force F1, the inside 21f of the opening 21e is pushed down below the claw receiving piece 11, and the claw receiving piece 11 is moved to the opening 21e of the engaging claw 21. The engaging claw 21 and the claw receiving piece 11 are engaged.

  FIG. 5 shows a state in which the engagement claw 21 and the claw receiving piece 11 are engaged. The engaging claw 21 is slightly elastically deformed downward, and generates a reaction force of the elastic deformation upward. That is, the first claw 21a and the connecting portion 21c generate an urging force F2 for fixing the case 1 and the cover 2 in the Y and Z directions, and the second claw 21b generates an urging force F3 in the Z direction. . For this reason, the urging force F3 is an urging force by which the inner side 21f of the opening 21e pulls the claw receiving piece 11 upward (in the Z direction) and fixes the claw receiving piece 11 to the case 1 and the cover 2. When the urging force F3 is generated on the engagement claw 21, the case 1 and the cover 2 can be firmly fixed.

  As described above, in the embodiment of the present invention, the deformed “U” -shaped engaging claw 21 provided on the case 1 is pressed and elastically deformed, and is engaged with the claw receiving piece 11 provided on the cover 2. I did it. Thereby, the engaging claw 21 generates an urging force due to the reaction force of the elastic deformation, and the case 1 and the cover 2 can be firmly fixed. Therefore, the fixing is prevented from being loosened by the urging force of the engaging claw 21, and the backlash between the case and the cover can be prevented. Further, since the engaging claw 21 is formed in a U-shape, a plurality of elastically deformable portions can be provided. For this reason, the engaging claw 21 does not concentrate on the base of the pressing force unlike the conventional inverted “L” -shaped engaging claw, and is not easily broken.

  <2. Modification>

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. The present invention can be modified. Hereinafter, modified examples will be described. Note that the above and below embodiments can be appropriately combined.

  In the above-described embodiment, it has been described that the connection portion 21c is pressed to engage the engagement claw 21 with the claw receiving piece 11. A protruding portion may be provided at a position of the connecting portion 21c to be pressed. FIG. 6 shows a projection 21g provided on the upper surface 21tf of the connection portion 21c. The height J of the projection 21g is 0.5 [mm] to 1.0 [mm]. By providing the protrusion 21g on the upper surface 21tf of the connection portion 21c, a portion of the connection portion 21c to be pressed by a presser can be visually recognized and sensed by tactile sensation. Thereby, in order to engage the engaging claw 21 with the claw receiving piece 11, the place to press the connecting portion 21c of the engaging claw 21 becomes clear to the presser, and the place to be pressed is easily pressed. Can be.

  Further, the connecting portion 21c in the above embodiment may be formed in a curved shape, for example, a substantially semicircular shape. FIG. 7 shows a connection part 21h having a substantially semicircular shape. The connection portion 21h connects the first claw portion 21a and the second claw portion 21b, and is pressed by a presser. In this case, the engaging claw 21 has a deformable “U” shape.

  In the above embodiment, the engaging claw 21 has the opening 21e. However, instead of the opening 21e, a hook-shaped body engaging with the claw receiving piece 11 may be provided. In short, the engaging claw 21 may have a shape that engages with the claw receiving piece 11.

  Further, in the above embodiment, the opening 21 e provided in the engagement claw 21 is engaged with the claw receiving piece 11 provided in the case 1. However, a claw receiving piece may be provided on the engagement claw 21 and an opening may be provided on the case 1. Regardless of the shape of the engaging claw 21 and the claw receiving piece 11, it is only necessary that the case 1 and the cover 2 can be fixed by the reaction force of the engaging claw 21 elastically deformed.

  In the above embodiment, the material of the cover 2 is PP (polypropylene). However, the material of the cover 2 may be another material. For example, plastic may be used. Nylon may be used. However, a thermoplastic resin is preferred. That is, any material may be used as long as it is a flexible material that is elastically deformed by being pressed to generate an urging force.

DESCRIPTION OF SYMBOLS 1 Case 2 Cover 3 Housing 11 Claw receiving piece 21 Engagement claw 21a First claw part 21b Second claw part 21c Connection part 21d Connection part

Claims (3)

A fixing structure for fixing a case having an opening surface and a cover that covers the opening surface,
An engagement claw provided on the cover,
A claw receiving member provided on a side surface of the case and engaging with the engagement claw;
With
The engagement claw has a first claw portion, a second claw portion, and a connection portion each having two pieces, and a connection portion,
The lower end of the first hook portion is fixed to the cover, the lower end portion of the second hook portion is an open end that is not fixed to the cover, the second claw portion is the first pawl portion substantially It is formed by extending in parallel,
The connection portion connects an upper end portion of the first claw portion and the second claw portion so that the engagement claw is bent in a substantially U-shape that is folded back and elastically deformed on the upper surface side of the cover. And provided at a position lower than the upper surface of the cover ,
The connection portion connects the vicinity of the open ends of the two pieces of the second claw portion,
A fixing structure, characterized in that an opening is formed inside each of the first claw portion, the second claw portion, and the connection portion and the connection portion . The fixing structure according to claim 1,
The fixing structure according to claim 1 , wherein a lower end portion of the first claw portion is provided to be disposed in a concave portion on a side surface of the cover. In the fixing structure according to claim 1 or 2,
The substantially U-shaped engagement claw has a curved shape.

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