Electronic devices

Abstract

To provide an electronic device in which a substrate is surely housed into a case, and load acted on the substrate is reduced.SOLUTION: An electronic device 1 comprises: a case main body 10; a circuit board 40; and a cover body 50. The case main body 10 includes: a support piece 19 that is stood from a bottom plate 11; a first elastic piece 29a that is elastically provided in a plate-thickness direction of the support piece 19 and in a deformable manner; and a first holding claw 29b that is projected into an inner side from the first elastic piece 29a. The circuit board 40 includes a first end surface 45 that is extended to a cross-direction X in such a way as to be opposite to an inner surface of the support piece 19. In at least a part of the first end surface 45, a first cut surface 45a cut to the cross-direction X is formed at a predetermined position. The first cut surface 45a is latched to the first holding claw 29b and pressurized into an inside in a vertical direction Y, the circuit board 40 is consequently held by the case main body 10.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electronic device.

Background Art

[0002] Conventionally, an electronic device that constitutes a controller or the like of an electronic apparatus has been known (see, for example, Patent Documents 1 to 3). Patent Document 1 discloses a security device including a case composed of a bottom plate and side walls rising from the bottom plate, a substrate disposed in the case, and elastic engaging claws that elastically deform in the plate thickness direction of the side walls and perform snap-fit connection with one side portion of the substrate. According to this configuration, by adopting the elastic engaging claws, the substrate can be attached to the case without using components such as screws.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, in the electronic devices described above, in order to improve manufacturing efficiency, a process called "multiple-cutting" is sometimes performed, where multiple circuit boards are cut from a single sheet of substrate material. In this case, perforated break lines are pre-formed in the substrate material, and the substrate material is cut along these break lines by bending it by hand, thereby manufacturing (separating) multiple circuit boards from a single sheet of substrate material. However, with this cutting method, the position of separation tends to vary from board to board, making it difficult to achieve dimensional accuracy. Therefore, if a circuit board is separated at a position where its dimensions are larger than expected due to variations in circuit board dimensions, the elastic engagement claws will deform more than expected, causing the case to bulge. In this case, the restoring force of the elastic engagement claws, which have deformed more than expected, will place an unexpected load on the circuit board and the electronic components mounted on it. On the other hand, if a circuit board is separated at a position where its dimensions are smaller than expected, the holding force of the circuit board by the elastic engagement claws will decrease. In addition, burrs and other protrusions or indentations may occur at the break line after cutting. Therefore, for example, if burrs or other protrusions occur, they will hinder the connection between the case and the circuit board. Thus, the cutting condition of the circuit board is an important factor in accurately fitting the board into the case.

[0005] Regarding the cutting of substrates, there are known methods to suppress the generation of protrusions such as burrs by devising the shape of the slit that constitutes the fractured portion (see, for example, Patent Document 2). In the printed circuit board described in Patent Document 2, a slit is formed by overlapping a hole that contacts the cutting location and a through groove that is larger in diameter than the diameter of the hole, has a semicircular tip, and extends along the cutting location. The generation of protrusions such as burrs is suppressed by this hole and through groove.

[0006] On the other hand, a technology has been disclosed that addresses the above-mentioned protrusions such as burrs by devising the structure of the case that houses the substrate (see, for example, Patent Document 3). In the case of the electronic control device described in Patent Document 3, a relief portion is provided in the part opposite to the connecting portion which is the cutting point of the substrate, forming a space between the connecting portion and the case. By accommodating the protrusions such as burrs in the relief portion, the substrate is housed in the case without being affected by the protrusions.

[0007] However, because the size of protrusions and indentations such as burrs is determined by chance, the dimensional variation of the substrate tends to be large. Furthermore, while it is possible to manufacture substrates at a low cost by forming a break section in advance and breaking the substrate by bending it by hand, the dimensional variation of the substrate is inherently high as described above. For this reason, it is difficult to address the above-mentioned problems regarding accommodation or load in either the structure of Patent Document 2 or Patent Document 3.

[0008] The present invention aims to provide an electronic device that accurately houses a substrate in a case and reduces the load acting on the substrate. [Means for solving the problem]

[0009] To solve the aforementioned problems and achieve the objective, the electronic device comprises a case body having a bottom plate and opening in a direction opposite to the bottom plate, a circuit board housed in the case body, and a cover body covering the opening of the case body, wherein the case body rises from the bottom plate It has side walls, and the side walls consist of a first side wall and a second side wall that face each other, The circuit board has the First side wall and second side wall Inside each It has a first end face that extends in a predetermined direction opposite to the first end face, and at least a portion of the first end face is provided with a first cutting surface formed at a predetermined position by cutting along the predetermined direction, A portion of the side wall is provided with an elastic piece formed by cutting out the side wall in the thickness direction and which is elastically deformable in the thickness direction, and a retaining claw protruding from the elastic piece toward the first cutting surface. The first cutting surface is locked to the retaining claw and pressed inward in an orthogonal direction perpendicular to the predetermined direction, thereby holding the circuit board in the case body. The circuit board has a third end face that extends opposite to the inner surface of the first side wall and the inner surface of the second side wall at a position different from the first end face, the third end face is an uncut surface, the distance between the first end face and the inner surface of the first side wall is smaller than the distance between the third end face and the inner surface of the first side wall, and the distance between the first end face and the inner surface of the second side wall is smaller than the distance between the third end face and the inner surface of the second side wall. It is characterized by the following:

[0010] According to the present invention, by providing a first cutting surface on at least a portion of the first end face of the circuit board, the dimensional accuracy of the portion that extends in a predetermined direction and engages with the retaining claw can be increased. As a result, even in situations where variations in the dimensional accuracy of the circuit board are expected due to the above-mentioned multiple-cavity molding process, the positional accuracy of the portion that engages with the retaining claw relative to the case body can be increased. Therefore, the circuit board can be accurately housed in the case body and the circuit board can be stably locked in place. Furthermore, by increasing the dimensional accuracy of the portion of the circuit board that engages with the retaining claw, deformation of the elastic piece beyond expectations is suppressed. Therefore, the generation of a restoring force exceeding expectations in the elastic piece is also suppressed, and unexpected loads on the circuit board are suppressed. Thus, it is possible to provide an electronic device that accurately houses the circuit board in the case and reduces the load acting on the circuit board. Furthermore, with this configuration, the distance between the first end face having the first cutting surface and the inner surface of the first or second side wall is set to be smaller than the distance between the third end face, which is not a cutting surface, and the inner surface of the first or second side wall. This makes it difficult for the third end face to come into contact with the first or second side wall, and ensures that the first cutting surface is securely locked in place by the retaining claws. Therefore, even if, for example, the third end face is formed by bending and breaking, causing variations in the dimensions of the circuit board, or if protrusions or indentations such as burrs are formed on the third end face, causing variations in the dimensions of the circuit board, the circuit board can be accurately housed in the case without being affected by these variations, and the load acting on the circuit board can be reduced.

[0011] In this case, it is preferable that the circuit board has a second end face that is perpendicular to the first end face and extends in the orthogonal direction, and that at least a part of the second end face is provided with a second cutting surface formed at a predetermined position by cutting along the orthogonal direction, and that the circuit board is positioned on the case body by the second cutting surface contacting or being close to a part of the case body. With this configuration, the position of the circuit board in the orthogonal direction is determined by the retaining claw and the first cutting surface, and the position of the circuit board in a predetermined direction is determined by the second cutting surface and a part of the case body. In other words, the circuit board is positioned with respect to the case body from at least two directions. As a result, the positional accuracy of the circuit board with respect to the case body is improved, and the state in which the circuit board is housed in the case body can be stably maintained.

[0012] Also, the above side wallIt preferably has ribs protruding inwardly of the case body, and the side surface of the rib and the second cutting surface are provided in contact with or close to each other. According to such a configuration, by bringing the side surface of the rib and the second cutting surface into contact with or close to each other, the position of the circuit board in a predetermined direction with respect to the case body can be determined. Further, according to this configuration, the side surface of the rib and the second cutting surface can also be brought into sliding contact with each other, and thus the rib can be used as a guide when attaching the circuit board to the case body. Therefore, the accommodation of the substrate in the case can be performed more accurately.

Effects of the Invention

[0014] According to the present invention, it is possible to provide an electronic device that accurately accommodates a substrate in a case and reduces the load acting on the substrate.

Brief Description of the Drawings

[0015] [Figure 1] Perspective view showing the assembled state of the electronic device according to the first embodiment of the present invention. [Figure 2] Exploded perspective view of the electronic device seen from the upper right. [Figure 3] Perspective view of the case body constituting the electronic device. [Figure 4] Exploded perspective view of the electronic device seen from the lower right. [Figure 5] Side view of the electronic device. [Figure 6] Top view of the substrate constituting the electronic device. [Figure 7] View showing the separation distance between the substrate and the case body. [Figure 8] Cross-sectional view taken along the line A-A of the electronic device in FIG. 5 as viewed in the arrow direction. [Figure 9] Enlarged view of the main part in the region A of FIG. 8. [Figure 10] Perspective view of the electronic device with the terminal block removed. [Figure 11] Front view of the electronic device in FIG. 10 as viewed from the front. [Figure 12] Perspective view of the electronic device according to the second embodiment. [Figure 13]Top view of the electronic device in Figure 12. [Figure 14] Top view of the protective cover that attaches to the case body. [Figure 15] (A) is a close-up view of one of the fixing holes provided in the case body, and (B) is a close-up view of the other fixing hole. [Modes for carrying out the invention]

[0016] The first embodiment of the present invention will be described below with reference to Figures 1 to 11. The electronic device 1 according to the first embodiment is used, for example, as a controller for an electric valve such as an electronic expansion valve that constitutes a refrigeration cycle. As shown in Figure 1, the electronic device 1 comprises a case body 10, a circuit board 40, and a cover body 50. In the following description, the thickness direction of the circuit board 40 will be referred to as the height direction, and will be written as "height direction Z". One side of the height direction Z will be referred to as "upper side Z1", and the other side as "lower side Z2". One side of the plane extension direction of the circuit board 40 perpendicular to the height direction Z will be referred to as the front-rear direction X (a predetermined direction), and the other side as the left-right direction Y (a perpendicular direction). One side of the front-rear direction X will be referred to as "front side X1", and the other side as "rear side X2". One side of the left-right direction Y will be referred to as "right side Y1", and the other side as "left side Y2".

[0017] It should be noted that these definitions of directions are for illustrative purposes only and do not necessarily correspond to the actual directions in which the electronic device 1 is used, nor do they limit the directions of the electronic device 1. For example, in the actual use of the electronic device 1, the lower Z2 portion in Figure 1 becomes the back of the electronic device 1 and is attached to the mounting object, and the upper Z1 portion becomes the front. In this case, the front-to-back direction X in Figure 1 becomes the up-to-down direction, and for example, the front X1 in Figure 1 may actually be the bottom, and the rear X2 in Figure 1 may actually be the top.

[0018] As shown in Figure 2, the case body 10 is formed in a box shape with an opening on the upper side Z1 by resin molding or the like. The case body 10 is equipped with a rectangular bottom plate 11 with a longer side in the left-right direction Y. The upper side Z1 surface of the bottom plate 11 constitutes a surface that supports the circuit board 40, and as shown in Figure 3, it has a mounting surface 12 in the center in the front-rear direction X. The mounting surface 12 is formed in a rectangular shape with a longer side in the left-right direction Y. Support protrusions 13 are formed at the four corners of the mounting surface 12, rising up from the upper side Z1, and the protruding ends 13a of the support protrusions 13 abut against the lower side Z2 surface of the circuit board 40, supporting the circuit board 40 in an upward position. As shown in Figure 4, the lower side Z2 surface of the bottom plate 11 constitutes a mounting surface 14 for mounting the electronic device 1 to the object to be mounted. A mounting groove 15 opening to the lower side Z2 is formed in the center of the mounting surface 14 in the front-rear direction X. The mounting groove 15 is formed on the mounting surface 14 from the right end Y1 to the left end Y2, extending in the left-right direction Y, and fits into a rail (not shown) to which it is to be mounted.

[0019] A guide groove 16 is formed in the center of the mounting groove 15 in the left-right direction Y, communicating with the mounting groove 15 and extending to the front end X1 of the mounting surface 14. A roughly rectangular DIN rail locking member 17 is installed in the guide groove 16 and is supported so as to be movable in the front-rear direction X. When the DIN rail locking member 17 is displaced to the front X1, the electronic device 1 can move in the left-right direction Y on the rail to be mounted via the mounting groove 15 fitted to the rail. On the other hand, when the DIN rail locking member 17 is displaced to the rear X2, the rear end X2 of the DIN rail locking member 17 presses against the rail, locking the electronic device 1 on the rail and preventing it from moving on the rail. With this configuration, the position of the electronic device 1 on the rail can be changed arbitrarily. At both the left and right ends of the front and rear edges of the mounting groove 15, die-cut holes 18 are formed that penetrate in the height direction Z. The mold-removal hole 18 is a hole for removing the mold when forming the first locking portion 29, which will be described later, and is formed at a position corresponding to the lower Z2 portion of the first locking portion 29.

[0020] As shown in Figure 2, a pair of support pieces 19 are formed on both the left and right edges of the bottom plate 11, rising upward Z1 and facing each other in the left-right direction Y. The support pieces 19 are side walls that support the circuit board 40 from the left-right direction Y. A first rail 20 (rib) is formed on the support piece 19, projecting inward. The first rail 20 is located within the first groove 41a of the circuit board 40, which will be described later, and serves as a guide for attaching the circuit board 40 to the case body 10. In this embodiment, the first rail 20 is formed on the front edge X1 and the rear edge X2 of each of the support pieces 19 on the right side Y1 and left side Y2, projecting inward in the left-right direction Y and extending in the height direction Z. The width dimension of the first rail 20 in the left-right direction Y increases towards the lower side Z2.

[0021] A second rail 31 is formed on the inner surface of the left-side support piece 19, at the center in the front-rear direction X, projecting inward in the left-right direction Y and extending in the height direction Z. The left-right dimension Y of the second rail 31 is constant across the height direction Z. The second rail 31 is located within the second groove 41b of the circuit board 40, which will be described later, and guides the attachment of the circuit board 40 to the case body 10. By forming the second rail 31 only on the left-side support piece 19 Y2, the circuit board 40 can only be housed in the case body 10 in the orientation in which the second rail 31 fits into the second groove 41b. This prevents the circuit board 40 from being housed in the case body 10 in the wrong orientation.

[0022] In this embodiment, the first rail 20 was formed on the front edge X1 and the rear edge X2 of the support piece 19 on the right side Y1 and left side Y2, respectively. However, the first rail 20 may be formed at any location on the support piece 19. Also, in this embodiment, the left-right dimension Y of the second rail 31 was kept constant along the height Z. However, this left-right dimension Y may increase towards the lower Z2, similar to the first rail 20. Furthermore, the second rail 31 does not necessarily have to be formed as a single unit in the center of the front-rear direction X on the inner surface of the support piece 19 on the left side Y2. It may be formed as one or more units at any location on the inner surface of the support piece 19 on the left side Y2, or as one or more units at any location on the support piece 19 on the right side Y1. Furthermore, when forming second rails 31 on the left and right support pieces 19, it is preferable to make the number of second rails 31 different on the right side Y1 and the left side Y2 so that the orientation of the circuit board 40 housed in the case body 10 is limited to one orientation.

[0023] The support piece 19 comprises a lower wall portion 21 (root portion) that constitutes the lower Z2 (case body bottom plate side) portion and an upper wall portion 22 (tip portion) that constitutes the upper Z1 (case body opening side) portion. The outer surface of the lower wall portion 21 is located outward in the left-right direction Y than the outer surface of the upper wall portion 22 (that is, the outer surface of the upper wall portion 22 is located inward in the left-right direction Y than the outer surface of the lower wall portion 21), and as a result, a stepped portion 23 is formed at the boundary between the lower wall portion 21 and the upper wall portion 22, extending in the left-right direction Y from the outer surface of the lower wall portion 21 to the outer surface of the upper wall portion 22. The lower wall portion 21 has a plate-shaped extension portion 24 that protrudes outward in the front-rear direction X.

[0024] In this embodiment, a pair of extensions 24 are formed on the front and rear of the lower wall portion 21. One of the extensions protrudes from the front edge X1 of the lower wall portion 21 to the front X1, extending beyond the front edge of the partition wall 52 (side wall) on the front X1 of the cover body 50 (described later). The other extension protrudes from the rear edge X2 of the lower wall portion 21 to the rear X2, extending beyond the rear edge of the partition wall 52 (side wall) on the rear X2 of the cover body 50. A fixing hole 25 is formed through the upper part of the extension 24, penetrating in the thickness direction of the plate. The fixing hole 25 is a through hole for fixing the protective cover 70 (described later). The fixing hole 25 is formed at a position below Z2 the stepped portion 23, below Z2 the connector insertion hole 57 (described later), and above Z1 the screw terminal block 42a and screwless terminal block 42b (described later), in order to avoid interference with components attached to the electronic device 1.

[0025] The protective cover 70 can be omitted, and in the first embodiment, the electronic device 1 omits this protective cover 70. A substantially rectangular recess 26 is formed in the center of the lower wall portion 21, recessed in the left-right direction Y. The bottom surface of the recess 26 is located in the left-right direction Y within the outer surface of the support piece 19. As a result, the lower wall portion 21 comprises a first wall portion 27 whose outer surface constitutes the outermost surface of the case body 10, and a second wall portion 28 in which the recess 26 is formed and recessed inward from the first wall portion 27. A first locking portion 29 for locking and holding the circuit board 40 is formed in the second wall portion 28.

[0026] The first locking portion 29 is a so-called snap-fit, formed by cutting a substantially U-shaped notch in the thickness direction of the second wall portion 28 (i.e., the support piece 19), and is elastically deformable in the left-right direction Y. The first locking portion 29 comprises a first elastic piece 29a (elastic piece) provided to be elastically deformable in the left-right direction Y, and a tapered first retaining claw 29b (retaining claw) provided to protrude inward from the inner surface of the first elastic piece 29a. In this embodiment, two of these first locking portions 29 are provided spaced apart in the front-rear direction X. Specifically, the first locking portions 29 are formed at both the front and rear ends of the second wall portion 28. However, the number and arrangement of the first locking portions 29 are not limited to this, and their number and arrangement can be changed as appropriate.

[0027] The upper wall portion 22 has a second locking portion 30 that locks and holds the cover side wall 59, which will be described later. Similar to the first locking portion 29, there are two second locking portions 30 spaced apart in the front-rear direction X. Specifically, the second locking portions 30 are formed at both the front and rear ends of the upper wall portion 22. The second locking portions 30 are also snap-fit, similar to the first locking portion 29, and are formed by cutting out an inverted U-shape in the thickness direction of the support piece 19, and are elastically deformable in the left-right direction Y. The second locking portion 30 comprises a second elastic piece 30a (elastic piece) that is elastically deformable in the left-right direction Y, and a tapered second retaining claw 30b (retaining claw) that protrudes outward in the left-right direction Y from the outer surface of the second elastic piece 30a. Furthermore, since both the first locking portion 29 and the second locking portion 30 are formed by cutting out a part of the support piece 19, the amount by which the first locking portion 29 and the second locking portion 30 protrude from the support piece 19 in the left-right direction Y can be reduced compared to when they are constructed separately from the support piece 19, thereby contributing to the miniaturization of the electronic device 1.

[0028] The circuit board 40 is, for example, a printed circuit board and is formed in a rectangular shape with a longer side in the left-right direction Y. The circuit board 40 is moved to the lower Z2 with its lower Z2 surface facing the bottom plate 11 and housed in the case body 10, and is supported across a pair of support pieces 19. As shown in Figure 6, the circuit board 40 comprises a substantially rectangular plate-shaped substrate 41, a circuit (not shown) provided on the substrate 41, and a plurality of electronic components mounted on the upper Z1 surface (front surface) of the substrate 41. In this embodiment, the plurality of electronic components are mounted on the upper Z1 surface of the substrate 41, but this is not limited to this, and as long as a plurality of electronic components are mounted on at least the upper Z1 surface of the substrate 41, electronic components may also be provided on the lower Z2 surface of the substrate 41. That is, the circuit board 40 may be a single-sided substrate with electronic components provided on one side (front surface), or a double-sided substrate with electronic components provided on both sides. Furthermore, circuits not shown can be provided on any part of the substrate 41, such as the upper surface Z1 of the substrate 41, the lower surface 2 of the substrate 41, both the upper and lower surfaces of the substrate 41, the edges of the substrate 41, or inside the substrate 41.

[0029] Multiple electronic components consist of outer components 42 arranged along the outer edge (front edge and rear edge in this embodiment) of the substrate 41, and inner components (not shown) arranged further inward from the outer components 42 on the substrate 41. In this embodiment, terminal blocks are arranged as outer components 42, and the component of the outer components 42 arranged along the left Y2 portion of the front edge of the substrate 41 is a screw terminal block 42a. In addition, the component of the outer components 42 located next to the screw terminal block 42a on the front X1 side, and along the rear edge of the substrate 41, is a screwless terminal block 42b. These screw terminal blocks 42a and screwless terminal blocks 42b are the parts that electrically connect the electronic device 1 to the external device.

[0030] The screw terminal block 42a and screwless terminal block 42b are formed in a box shape, and are electrically connected to the circuit board 41 by inserting the board connection terminals (not shown) of the screw terminal block 42a and screwless terminal block 42b into the insertion holes 42c shown in Figure 10 and soldering them. As shown in Figure 6, a first groove 41a for accommodating the first rail 20 of the case body 10 is formed on the right edge Y1 and the left edge Y2 of the circuit board 41. The first groove 41a is cut inward and opens outward. The first groove 41a is formed on the front X1 portion and the rear X2 portion of the circuit board 41, respectively, to match the position of the first rail 20. The depth of the first groove 41a is set to be approximately the same as the left-right direction Y dimension at the lower end of the first rail 20. When moving the circuit board 40 from the upper Z1 to the lower Z2 of the case body 10, the inner surface of the first groove 41a is guided by contacting or coming close to the first rail 20.

[0031] In this case, because the depth of the first groove 41a is as described above, the more the circuit board 40 is positioned on the upper side Z1, the less likely the first rail 20 and the inner surface of the first groove 41a are to come into contact or come close, making it easier to move the circuit board 40. On the other hand, the more the circuit board 40 moves on the lower side Z2, the more likely the first rail 20 and the inner surface of the first groove 41a are to come into contact or come close, so the circuit board 40 is less likely to be displaced relative to the case body 10, and the position of the circuit board 40 relative to the case body 10 is determined more accurately. Furthermore, a second groove 41b for accommodating the second rail 31 is formed in the center of the front-to-back direction X at the left edge Y2 of the board 41.

[0032] As described above, the second rail 31 has the function of specifying the orientation of the circuit board 40 when it is housed in the case body 10 in one direction. Therefore, the second groove 41b that houses the second rail 31 has the function of preventing mis-fitting. The second groove 41b is notched inward and opens outward. The depth of the second groove 41b is set to be approximately the same as the left-right dimension Y of the second rail 31. When the circuit board 40 is moved from the upper side Z1 to the lower side Z2 of the case body 10, the inner surface of the second groove 41b comes into contact with or comes close to the second rail 31, similar to how the inner surface of the first groove 41a comes into contact with or close to the first rail 20, thereby guiding the circuit board 40.

[0033] The circuit board 40 configured in this way is formed by a process called "multiple cuts," where multiple boards are cut from a single board material. In this embodiment, multiple cuts are performed using two different cutting methods. Specifically, first, an NC router is used to cut the board material at a predetermined position by rotating a cutting tool with a cutting edge on its outer circumference through it, and controlling the coordinates of the tool with a servo motor or the like to cut the predetermined part of the board material. Next, continuous or intermittent grooves are formed in the parts of the board material that have not been NC router-processed to create a fracture section, and the board 41 is bent to break it from this fracture section in a "bending fracture" process. For example, in this embodiment, a V-shaped groove is formed continuously to create a fracture section, and the board 41 is bent to perform a V-cut that breaks it from this fracture section.

[0034] NC router processing offers superior precision, thus suppressing dimensional variations in the circuit boards 40 after multiple cuts have been made. Specifically, in terms of cutting precision, if the dimensional tolerance resulting from V-cutting is about 1 / 10, the dimensional tolerance resulting from NC router processing is about 1 / 100. On the other hand, V-cutting does not require precise control of tools, etc., making it efficient and cost-effective. In this embodiment, V-cutting is performed as an example of bending fracture, but this is not the only method. For example, perforated fracture sections may be formed in areas of the substrate material that have not been NC router processed by intermittent grooves or slits, and these perforated fracture sections may be fractured by bending the substrate 41. In this embodiment, bending fracture such as V-cutting is performed after NC router processing, but multiple cuts may be made first using only bending fracture such as V-cutting, and then NC router processing may be performed on necessary areas such as the first end face and second end face.

[0035] In this embodiment, the front edge of the substrate 41 forms a V-cut front V-cut surface 43, and the rear edge of the substrate 41 forms a V-cut rear V-cut surface 44. At both left and right edges of the substrate 41, the portion between the first groove 41a on the front side X1 and the first groove 41a on the rear side forms a first end surface 45 extending in the front-rear direction X, the inner surface of the first groove 41a forms a second end surface 46, and the portion of the second end surface 46 on the outward side in the front-rear direction X forms a third end surface 47 extending in the front-rear direction X. As shown in Figure 7, the first end surface 45 faces the inner surface of the support piece 19, specifically the inner surface of the second wall portion 28, and extends in the front-rear direction X along that inner surface. At least a portion of the first end surface 45, specifically the portion facing the first locking portion 29, forms a first cut surface 45a formed at a predetermined position by cutting along the front-rear direction X using NC router processing.

[0036] As shown in Figure 8, in the area where the first cutting surface 45a is provided, the dimension in the left-right direction Y from the first cutting surface 45a on the right side Y1 to the first cutting surface 45a on the left side Y2 is greater than the distance from the tip of the first retaining claw 29b on the first locking portion 29 on the right side Y1 to the tip of the first retaining claw 29b on the left side Y2. As a result, as shown in Figure 9, when the circuit board 40 is housed in the case body 10, the tip of the first retaining claw 29b is pressed by the first cutting surface 45a, causing the first elastic piece 29a to elastically deform outward in the left-right direction Y. The restoring force causes the first cutting surface 45a to lock with the first retaining claw 29b and is pressed inward in the left-right direction Y, thereby holding the circuit board 40 in the case body 10. Furthermore, in this case, the circuit board 40 is supported upward by the support projection 13 described above, and is pressed downward by the lower surface of the first retaining claw 29b, and is sandwiched in the height direction Z between the protruding end 13a of the support projection 13 and the lower surface of the first retaining claw 29b. This prevents the circuit board 40 from coming loose in the height direction Z. In this way, the circuit board 40 can be easily fixed to the case body 10 without using screws, pins, or the like.

[0037] Furthermore, by providing the first cutting surface 45a, the dimensional accuracy of the portion of the circuit board 40 that extends in the front-to-back direction X and engages with the first retaining claw 29b can be improved. As a result, even if variations in the dimensional accuracy of the circuit board 40 are expected due to the aforementioned multiple-cavity manufacturing process, the positional accuracy of the portion formed on the first retaining claw 29b relative to the case body 10 can be improved. In addition, by improving the dimensional accuracy of the portion of the circuit board 40 that engages with the first retaining claw 29b, the amount of elastic deformation of the first locking portion 29 is less likely to exceed expectations, and the force with which the first locking portion 29 holds the circuit board 40 can be stabilized.

[0038] This is particularly evident when the first cutting surface 45a is provided on both the left and right sides of the circuit board 40, as in this embodiment. This allows the left-right dimension Y of the circuit board 40 in the area where the first cutting surface 45a is formed to be kept constant with high precision, and the amount of elastic deformation of the first locking portion 29 to be kept constant. As a result, the force with which the first locking portion 29 holds the circuit board 40 can be kept constant. Furthermore, because the first locking portion 29 is provided on the second wall portion 28, which is recessed inward from the first wall portion 27, rather than on the first wall portion 27 that constitutes the outermost surface of the case body 10, it is difficult for parts, tools, etc. from the outside to collide with the first locking portion 29, and external forces are less likely to act directly on the circuit board 40 through the first locking portion 29. Therefore, the state in which the circuit board 40 is held by the first locking portion 29 is stably maintained.

[0039] The second end face 46 is composed of a portion that is continuous with the first end face 45 and extends in the left-right direction Y perpendicular to the first end face 45, and an arc-shaped portion that connects this portion extending in the left-right direction Y. That is, the second end face 46 has a portion that extends in the left-right direction Y perpendicular to the first end face 45. Of the second end face 46, the portion extending in the left-right direction Y is in contact with or close to the side surface of the first rail 20 described above, and at least this contact or close portion constitutes a second cut surface 46a formed at a predetermined position by cutting along the left-right direction Y by NC router processing. When this second cut surface 46a contacts or is close to the side surface of the first rail 20, the displacement of the circuit board 40 in the front-rear direction X is restricted.

[0040] In other words, the circuit board 40 is positioned on the case body 10 by the second cut surface 46a contacting or being close to a part of the case body 10. The third end surface 47 is a bent fracture surface (uncut surface) formed by the V-cut (bending fracture) described above, and extends outward in the front-rear direction X, continuous with the second end surface 46. As shown in Figure 7, the third end surface 47 faces the inner surface of the support piece 19, specifically the inner surface of the first wall portion 27, and extends in the front-rear direction X along that inner surface. In other words, the third end surface 47 faces the inner surface of the support piece 19 at a different position from the first end surface 45 and extends in the front-rear direction X.

[0041] As described above, from the viewpoint of stabilizing the force with which the first locking portion 29 holds the circuit board 40, it is preferable that the distance S1 (shown only in Figure 7) between the first cut surface 45a (first end surface 45) and the inner surface of the second wall portion 28 (support piece 19) be formed to be smaller than the distance S2 between the third end surface 47 and the inner surface of the first wall portion 27 (support piece 19). This makes it difficult for the third end surface 47, which has greater dimensional variation than the first cut surface 45a, to come into contact with the case body 10, and ensures that the first cut surface 45a, which has less dimensional variation, is securely locked by the first locking portion 29. Furthermore, by maintaining this relationship between the separation distances S1 and S2, even if parts or tools collide with parts other than the second wall portion 28, specifically the first wall portion 27, a space is secured between the circuit board 40 and the case body 10. This prevents external forces applied to the case body 10 from directly acting on the circuit board 40.

[0042] The cover body 50 is a component that covers the opening of the case body 10 and is detachably attached to the case body 10 in the height direction Z. As shown in Figure 10, the cover body 50 has a top plate 51 that faces the upper surface Z1 of the substrate 41 (circuit board 40). The top plate 51 is formed in the shape of a rectangular plate with its longer side in the left-right direction Y. The front and rear edges that constitute the longer side of the top plate 51 constitute the outermost edge of the cover body 50 in the front-rear direction X, and a pair of partition walls 52 (side walls) hang down from this outermost edge toward the upper surface Z1 of the substrate 41. The partition walls 52 are walls that separate the outer components 42 from the inner components (not shown), and prevent tools used to solder screw terminal blocks 42a and screwless terminal blocks 42b to the substrate 41, as well as other items such as screws used in the outer components 42, tools for tightening screws, and the fingers of workers handling the electronic device 1 (hereinafter also referred to as foreign objects) from coming into contact with the inner components.

[0043] In order to prevent foreign objects from coming into contact with the internal components, it is conceivable to cover the entire area around the external components 42, such as the screw terminal block 42a and screwless terminal block 42b. However, in this case, the shape of the cover body 50 becomes complex, reducing its versatility. Therefore, a simple configuration with a partition wall 52 hanging down from the top plate 51, as in this embodiment, is preferable. The left-right Y-ends of the inner wall surface of the partition wall 52 are slidable against the X-outward surfaces (outer surfaces) of the side walls of the first rail 20 formed on the front and rear edges of the support piece 19 of the case body 10. As a result, the cover body 50 moves in the height Z-direction while being guided by the first rail 20 and is attached to the case body 10.

[0044] As shown in Figure 11, a protrusion 53 projecting downward Z2 is formed on the lower edge (tip edge) of the partition wall 52. In this embodiment, the protrusion 53 is formed on both the left and right ends of the lower edge of the partition wall 52. The protrusion 53 is positioned with a predetermined gap in the height direction Z relative to the upper surface Z1 of the substrate 41. The formation of the protrusion 53 allows the circuit board 40 to be prevented from lifting in the height direction Z (thickness direction) if it is lifted due to impact or vibration, etc., by bringing the protrusion 53 into contact with the upper surface Z1 of the substrate 41. Furthermore, by forming the protrusion 53 on both the left and right ends of the lower edge of the partition wall 52, a recess 54 opening downward Z2 is formed between each protrusion 53. The upper edge 55 (edge) of the recess 54 is further away from the upper surface Z1 of the substrate 41 in the upper Z1 direction (height direction Z) than the protrusion 53. The formation of this recess 54 creates a space between the substrate 41 and the partition wall 52, preventing interference between the partition wall 52 and electronic components. Therefore, this space can be used as a mounting space for electronic components, and electronic components can be mounted on the substrate 41 even in a portion of the area where the partition wall 52 is located.

[0045] On the other hand, as shown in Figure 8, the upper edge 55 of the recess 54 is located below Z2 the upper end 42d of the screw terminal block 42a. Also, the upper edge 55 of the recess 54 is located below Z2 the upper end 42e of the screwless terminal block 42b. In other words, the upper edge 55 of the recess 54 is located closer to the substrate 41 than the upper end of the outer component 42. As a result, the space created by the screw terminal block 42a and screwless terminal block 42b and the recess 54 overlaps in the front-to-back direction X, and the screw terminal block 42a and screwless terminal block 42b prevent foreign matter from entering the inside of the cover body 50 through the recess 54. A second protrusion 53a is formed at the center of the left-to-right direction Y of the upper edge 55 of the recess 54 (i.e., the lower edge of the partition wall 52), projecting downward Z2. The second protrusion 53a is positioned with a predetermined gap in the height direction Z relative to the upper surface Z1 of the substrate 41, and, like the protrusion 53, suppresses the lifting of the circuit board 40. However, from the viewpoint of forming the recess 54 described above, the second protrusion 53a is not essential and can be omitted.

[0046] As shown in Figure 2, screw terminal blocks 42a and screwless terminal blocks 42b (outer parts 42) are attached to the front X1 or rear X2 portion of the partition wall 52 via the insertion holes 42c shown in Figure 10. Therefore, in order to facilitate the installation work, it is preferable to provide a predetermined gap in the front-rear direction X between the outer surface of the partition wall 52 and the back surface of the screw terminal block 42a or screwless terminal block 42b (outer parts 42) (the surface facing the outer surface of the partition wall 52). However, if the predetermined gap becomes too large, the aforementioned foreign matter may enter the gap and come into contact with the inner parts inside the cover body 50 via the recess 54 described above.

[0047] Therefore, it is preferable that the predetermined gap be smaller than the gap between the upper edge 55 of the recess 54 and the upper surface Z1 of the substrate 41. It is also preferable that the predetermined gap be set to a dimension smaller than the foreign matter described above. Specifically, for example, it is preferable that the predetermined gap be set to a dimension smaller than the head of the screw used in the outer component 42, or the tip of the tool used to tighten the screw. For example, in this embodiment, the predetermined gap was set to about 5 mm. That is, the partition wall 52 is provided on the inward side of the outer component 42 with a predetermined gap in between. Furthermore, by providing this predetermined gap, the gap can be used as a mounting space for the electronic components described above. This makes it possible to further increase the mounting space for electronic components.

[0048] A slit 56 is formed on the plate surface of the partition wall 52, penetrating in the thickness direction and extending in the height direction Z. Multiple slits 56 are formed side by side in the left-right direction Y. The width of the slit 56 is approximately 3 mm, which is smaller than the gap between the upper edge 55 of the recess 54 and the upper Z1 surface of the substrate 41, and the predetermined gap between the outer surface of the partition wall 52 and the back surface of the outer component 42. In addition, a connector insertion hole 57 (see Figure 2) penetrating in the thickness direction is formed in the upper right portion of the plate surface of the partition wall 52 that constitutes the front X1 portion of the cover body 50. A connector provided on the conductor of an external device (not shown) is to be inserted into the connector insertion hole 57, thereby connecting the external device and the electronic device 1. Note that the connector insertion hole 57 may be omitted in drawings other than Figure 2.

[0049] As shown in Figure 11, the lower portions of both the left and right ends of the partition wall 52 have side end surfaces 58 that are located inward from the outer surface of the cover side wall 59 (described later) and face outward in the left-right direction Y. These side end surfaces 58 constitute a restricting surface that abuts against or is close to the inner surface of the support piece 19 of the case body 10. The side end surfaces 58 restrict the support piece 19 from tilting inward in the left-right direction Y. In other words, the position of the support piece 19 is restricted by the side end surfaces 58 abutting against or being close to the inner surface of the support piece 19. In this way, because the partition wall 52 is provided with side end surfaces 58, the lower Z2 portion of the cover body 50 is housed inside the case body 10 between a pair of support pieces 19.

[0050] As shown in Figure 10, a pair of cover side walls 59 hang down from the left and right edges that constitute the short side of the top plate 51, as side walls distinct from the partition wall 52. The cover side walls 59 are formed in a plate shape with a smaller height dimension than the partition wall 52, and locking holes 60 are formed through their plate surfaces, each having an edge portion that engages with the second retaining claw 30b of the second locking portion 30. The distance in the left-right direction Y from the inner surface of the cover side wall 59 on the right side Y1 to the inner surface of the cover side wall 59 on the left side Y2 is greater than the left-right direction Y dimension from the outer surface of the upper wall portion 22 on the right side Y1 to the outer surface of the upper wall portion 22 on the left side Y2 of the case body 10. Furthermore, the distance in the left-right direction Y from the inner surface of the cover side wall 59 on the right side Y1 to the inner surface of the cover side wall 59 on the left side Y2 is smaller than the distance from the tip of the second retaining claw 30b of the second locking portion 30 on the right side Y1 to the tip of the second retaining claw 30b on the left side Y2.

[0051] Furthermore, the height dimension Z of the cover side wall 59 is set to be greater than the distance from the upper Z1 end face of the upper wall portion 22 of the case body 10 to the stepped portion 23 of the case body 10. The lower end edge 59a (downward edge) of the cover side wall 59 abuts against the stepped portion 23 of the case body 10 when the cover body 50 is attached to the case body 10, thereby restricting the displacement of the cover body 50 downward Z2. With this configuration, as shown in Figure 10, when the cover body 50 is attached to the case body 10, the inner surface of the cover side wall 59 overlaps with the outer surface of the upper wall portion 22, and the cover side wall 59 covers the upper part of the case body 10. At this time, the inner surface of the cover side wall 59 presses against the second retaining claw 30b, causing the second elastic piece 30a to elastically deform inward in the left-right direction Y. Due to this restoring force, the edge of the locking hole 60 is locked to the second retaining claw 30b and pressed outward in the left-right direction Y, thereby holding the cover body 50 to the case body 10.

[0052] In other words, the cover side wall 59 is locked to the outer surface of the support piece 19 above the first locking portion 29 at Z1 (the opening side of the case body 10). The lower end edge 59a of the cover side wall 59 abuts against the stepped portion 23 of the case body 10, thereby restricting its displacement downward Z2. That is, the position of the cover body 50 is restricted by the downward end edge of the cover side wall 59 abutting against the stepped portion 23. Since the mounting of the cover body 50 is completed by bringing the lower end edge 59a of the cover side wall 59 into contact with the stepped portion 23, there is no need to provide any additional members such as stoppers.

[0053] In this way, when the cover body 50 is attached to the case body 10, the cover side wall 59 covers the upper Z1 portion of the case body 10 from the outside, and the displacement of the support piece 19 in the left-right direction Y outward is restricted by the cover side wall 59. With this configuration, when the cover body 50 is attached to the case body 10, the displacement of the support piece 19 in the left-right direction Y outward is restricted by the cover side wall 59 located on the upper outer side of the support piece 19, and the displacement of the support piece 19 inward is restricted by the side end surface 58 of the partition wall 52 located on the lower inner side of the support piece 19. As a result, the support piece 19 is less likely to tilt relative to the bottom plate 11.

[0054] In the electronic device 1 of this embodiment, configured as described above, the protruding direction of the first retaining claw 29b in the first locking portion 29 and the protruding direction of the second retaining claw 30b in the second locking portion 30 are opposite. As a result, within the same support piece 19, the first locking portion 29 elastically deforms outward in the left-right direction Y, and the second locking portion 30 elastically deforms inward in the left-right direction Y. Therefore, for example, when the circuit board 40 causes the first locking portion 29 to elastically deform, the force is transmitted to the second locking portion 30 via the support piece 19, and this force presses the second locking portion 30 against the cover side wall 59. In other words, the force applied to the first locking portion 29 is applied to the second locking portion 30. On the other hand, when the cover side wall 59 causes the second locking portion 30 to elastically deform, the force is transmitted to the first locking portion 29 via the support piece 19, and this force presses the first locking portion 29 against the circuit board 40. In other words, the force applied to the second locking portion 30 is added to the first locking portion 29. In this way, the forces applied to the first locking portion 29 and the second locking portion 30 can be added to each other, improving the holding force of the first locking portion 29 and the second locking portion 30. Furthermore, by making the second retaining claw 30b of the second locking portion 30 protrude outward in the left-right direction Y, the shape of the upper part of the mold when forming the first locking portion 29 can be simplified, and the molding process can be made easier.

[0055] In this case, the support piece 19 may tilt outward in the left-right direction Y as the first elastic piece 29a, pressed by the circuit board 40, elastically deforms outward in the left-right direction Y. This becomes particularly noticeable when the left-right dimension Y of the circuit boards 40 varies to the larger side when the circuit boards 40 are manufactured using a multiple-piece mold, as in this embodiment. In this case, the first locking portion 29 and the support piece 19 attempt to deform more than expected, placing an excessive load on the base of the support piece 19, which has a boundary with the bottom plate 11 and is difficult to displace, resulting in durability problems. Furthermore, the reaction force increases as the first locking portion 29 and the support piece 19 attempt to deform more than expected, increasing the load on the circuit board 40. However, as described above, the cover side wall 59 overlaps and locks to the outer surface of the support piece 19 above the first locking portion 29 Z1 (the opening side of the case body 10), and the tip of the support piece 19 is restricted from displacement by the cover side wall 59. Therefore, excessive load concentration at the base of the support piece 19 and the occurrence of a load exceeding expectations on the circuit board 40 are suppressed.

[0056] On the other hand, as the second elastic piece 30a, pressed by the cover side wall 59, elastically deforms inward in the left-right direction Y, the support piece 19 may also attempt to tilt inward in the left-right direction Y. In this case, as with the case where the support piece 19 attempts to tilt outward in the left-right direction Y in accordance with the elastic deformation of the first elastic piece 29a, an excessive load is placed on the base of the support piece 19, and the load on the circuit board 40 increases. However, as described above, the tilt of the support piece 19 is restricted by the side end face 58 of the partition wall 52, thus preventing an excessive load from concentrating on the base of the support piece 19 and preventing the circuit board 40 from experiencing a load greater than expected.

[0057] As described above, according to the first embodiment, by providing a first cutting surface 45a on at least a part of the first end face 45 of the circuit board 40, the dimensional accuracy of the portion that extends in the front-rear direction X (a predetermined direction) and engages with the first retaining claw 29b (retaining claw) can be increased. As a result, even in situations where variations in the dimensional accuracy of the circuit board 40 are expected due to the above-mentioned multiple-piece molding, the positional accuracy of the portion that engages with the first retaining claw 29b relative to the case body 10 can be increased. Therefore, the circuit board 40 can be accurately housed in the case body 10 and the circuit board 40 can be stably engaged. Furthermore, by increasing the dimensional accuracy of the portion of the circuit board 40 that engages with the first retaining claw 29b, deformation of the first elastic piece 29a (elastic piece) beyond what is expected is suppressed. Therefore, the generation of a restoring force beyond what is expected in the first elastic piece 29a is suppressed, and unexpected loads on the circuit board 40 are suppressed. Therefore, it is possible to provide an electronic device 1 that accurately houses the circuit board 40 (board) into the case body 10 (case) and reduces the load acting on the circuit board 40.

[0058] Furthermore, according to this embodiment, the position of the circuit board 40 in the left-right direction Y (orthogonal direction) is determined by the first retaining claw 29b and the first cutting surface 45a, while the position of the circuit board 40 in the front-rear direction X (predetermined direction) is determined by the second cutting surface 46a and the side wall of the first rail 20 (part of the case body 10). In other words, the circuit board 40 is positioned from at least two directions relative to the case body 10. As a result, the positional accuracy of the circuit board 40 relative to the case body 10 is improved, and the state in which the circuit board 40 is housed in the case body 10 can be stably maintained.

[0059] Furthermore, according to this embodiment, the position of the circuit board 40 in the front-rear direction X relative to the case body 10 can be determined by bringing the side surface of the first rail 20 (rib) into contact with or close to the second cutting surface 46a. Therefore, the side surface of the first rail 20 and the second cutting surface 46a can be brought into sliding contact, and the first rail 20 can be used as a guide when attaching the circuit board 40 to the case body 10. Consequently, the placement of the circuit board 40 into the case body 10 can be made even more accurate.

[0060] Furthermore, according to this embodiment, the distance S1 (distance) between the first cutting surface 45a (first end surface 45) having the first cutting surface 45a and the inner surface of the support piece 19 is set to be smaller than the distance S2 (distance) between the third end surface 47, which is a non-cutting surface, and the inner surface of the support piece 19. This makes it difficult for the third end surface 47 and the support piece 19 to come into contact, and the first cutting surface 45a can be reliably locked by the first retaining claw 29b (retaining claw). For this reason, even if, for example, the third end surface 47 is formed by bending and breaking, causing variations in the dimensions of the circuit board 40, or if protrusions or indentations such as burrs are formed on the third end surface 47, causing variations in the dimensions of the circuit board 40, the circuit board 40 can be accurately housed in the case body 10 without being affected, and the load acting on the circuit board 40 can be reduced.

[0061] Furthermore, according to this embodiment, the partition wall 52 that hangs down from the top plate 51 toward the upper surface Z1 of the circuit board 41 can separate the outer components 42 and the inner components of the electronic components of the circuit board 40 in the inward and outward directions. For example, it is possible to prevent foreign objects such as tools or the fingers of workers handling electronic devices from coming into contact with the inner components without covering most of the area around the screw terminal block 42a or screwless terminal block 42b (outer components 42) as outer components 42. In addition, since a predetermined gap is provided between the outer surface of the partition wall 52 and the back surface of the outer components 42, this gap can be used as a mounting space for electronic components, and a large mounting space can be secured. Moreover, since the cover body 50 can be constructed with a simple structure consisting of a top plate 51 and a partition wall 52 hanging down from the top plate 51, and does not depend on the outer shape of the outer components 42 or inner components, the cover body 50 has high versatility, and a wide variety of screw terminal blocks 42a and screwless terminal blocks 42b can be mounted. Therefore, it is possible to provide an electronic device 1 equipped with a highly versatile cover body 50 (cover) that suppresses contact of foreign matter with internal electronic components with a simple configuration.

[0062] Furthermore, according to this embodiment, for example, if the circuit board 40 lifts up in the height direction Z (thickness direction) due to impact or vibration, the lifting can be suppressed by bringing the protrusion 53 of the partition wall 52 into contact with the upper surface Z1 of the substrate 41. Also, with this configuration, a predetermined gap in the height direction Z is created between the upper edge 55 (edge) of the recess 54 of the partition wall 52 and the upper surface Z1 of the substrate 41, and this gap can be used as a mounting space for the electronic components mentioned above. And, since the upper edge 55 of the recess 54 is located closer to the substrate 41 than the upper end 42d of the outer component 42, the partition wall 52 and the outer component 42 overlap in the front-to-back direction X (inside-to-outside direction), and it is possible to suppress foreign matter from entering the interior of the electronic device 1 through the gap between the partition wall 52 and the outer component 42.

[0063] Furthermore, according to this embodiment, by making the inner surface of the partition wall 52 slidable against the outer surface of the first rail 20 (rib), the cover body 50 can be moved in the height direction Z (plate thickness direction) while the partition wall 52 of the cover body 50 is guided by the outer surface of the first rail 20, and the cover body 50 can be attached to the case body 10. Therefore, the cover body 50 can be attached to the case body 10 easily and accurately.

[0064] Furthermore, according to this embodiment, the gap in a predetermined direction between the outer surface of the partition wall 52 and the back surface of the outer component 42 is set to a dimension smaller than the screws used in the outer component 42 and the tips of tools used to tighten the screws (foreign objects). Therefore, it is possible to suppress the entry of these foreign objects into the interior of the electronic device 1 through the gap between the partition wall 52 and the outer component 42.

[0065] Furthermore, according to this embodiment, even if the dimensions of the circuit board 40 housed in the case body 10 vary in an upward direction, and the first locking portion 29 and support piece 19 attempt to deform more than expected, the cover side wall 59 overlaps the outer surface of the support piece 19 on the opening side of the case body 10 and locks it in place. As a result, the tip of the support piece 19 is restricted from displacement by the cover side wall 59, making it difficult for the support piece 19 to tilt outward from its base on the bottom plate 11 side. This prevents excessive load from concentrating at the base of the support piece 19. Therefore, it is possible to provide an electronic device 1 that prevents excessive load from being placed on the structure for fixing the circuit board 40 (substrate).

[0066] Furthermore, according to this embodiment, since the support piece 19 of the case body 10 is cut out to provide the first elastic piece 29a (elastic piece), the amount of protrusion of the first locking portion 29 from the case body 10 can be reduced compared to the case in which the first elastic piece 29a is constructed separately from the support piece 19, and the case body 10 can be made smaller as a result.

[0067] Furthermore, according to this embodiment, when the first locking portion 29 is pressed from the inside outward by the inner circuit board 40 and undergoes elastic deformation, the force is transmitted to the second locking portion 30 via the support piece 19, and this force causes the second locking portion 30 to press against the cover side wall 59. In other words, the force applied to the first locking portion 29 is added to the second locking portion 30. On the other hand, when the second locking portion 30 is pressed from the outside inward by the outer cover side wall 59 and undergoes elastic deformation, the force is transmitted to the first locking portion 29 via the support piece 19, and this force causes the first locking portion 29 to press against the circuit board 40. In other words, the force applied to the second locking portion 30 is added to the first locking portion 29. In this way, by making the protruding directions of the first locking portion 29 and the second locking portion 30 different on the inside and outside of the support piece 19, the forces applied to the first locking portion 29 and the second locking portion 30 can be added to each other, thereby improving the holding force of the first locking portion 29 and the second locking portion 30.

[0068] Furthermore, according to this embodiment, the stepped portion 23 that constitutes the boundary between the lower wall portion 21 and the upper wall portion 22 in the support piece 19 can be used as a structure that restricts the position of the cover body 50 when the lower end edge 59a (downward-facing edge) of the cover side wall 59 abuts against it. Therefore, the positioning of the cover body 50 relative to the case body 10 can be made with a simple structure without having to attach any special components such as a stopper to the case body 10.

[0069] Furthermore, according to this embodiment, the side end surface 58 of the cover body 50 overlaps the inner surface of the support piece 19 as a restricting surface. Therefore, when the case body 10 and the cover body 50 are assembled, the cover side wall 59 overlaps the outer surface of the support piece 19, and it is possible to suppress the support piece 19 from collapsing inward due to pressure from the cover side wall 59.

[0070] Furthermore, according to this embodiment, since the first elastic piece 29a (elastic piece) of the first locking portion 29 is provided by cutting out the second wall portion 28 of the support piece 19, the amount of protrusion of the first locking portion 29 from the case body 10 can be reduced compared to the case in which the first elastic piece 29a is constructed separately from the support piece 19, and the case body 10 can be made smaller accordingly. In addition, since the second wall portion 28 having the first locking portion 29 is recessed inward from the first wall portion 27 which constitutes the outermost surface of the support piece 19, it is difficult for parts, tools, etc. from the outside to collide with it, and it is less susceptible to external forces. As a result, it is possible to suppress the external force from directly becoming a load on the circuit board 40. Thus, it is possible to provide an electronic device 1 that is small while making it difficult for external forces to be applied to the circuit board 40 (substrate).

[0071] Furthermore, according to this embodiment, in the relationship between the circuit board 40 and the support piece 19 of the case body 10, as described above, the distance S1 between the second wall portion 28, which is less susceptible to external forces, and the first end face 45 (the end face extending in the front-rear direction X (a predetermined direction) along the inner surface of the second wall portion 28) is greater than the distance S2 between the first wall portion 27, which is more susceptible to external forces, and the third end face 47 (the end face extending in the left-right direction Y (a predetermined direction) opposite the inner surface of the first wall portion 27). Therefore, even if an external force is applied to the case body 10, such as when a component or tool collides with the first wall portion 27 from the outside, it is possible to suppress the direct load on the circuit board 40 from that external force.

[0072] Furthermore, according to this embodiment, in the electronic device 1 described above, the first locking portion 29 that locks and holds the circuit board 40 is pressed by the circuit board 40 and elastically deforms outward from the case body 10, and in conjunction with this, the second wall portion 28 having the first locking portion 29 may attempt to deform outward from the case body 10. In this case, the reaction force of the elastically deformed first locking portion 29 may place a load on the circuit board 40. However, with this configuration, the cover side wall 59 is provided overlapping the outer surface side of the support piece 19 having the first locking portion 29 on the opening side of the case body 10, so the displacement of the support piece 19 is restricted by the cover side wall 59, and the elastic deformation outward from the case body 10 is mitigated. In addition, since the elastic deformation of the first locking portion 29 outward from the case body 10 is also mitigated, the reaction force of the first locking portion 29 described above is also mitigated, and the load on the circuit board 40 can be reduced.

[0073] Although embodiments and modifications of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and any design changes, etc., that do not depart from the gist of the present invention are also included in the present invention. Figure 12 is a perspective view of the electronic device 1' according to the second embodiment. The second embodiment differs from the first embodiment in that the protective cover 70 described above is not omitted. The protective cover 70 is a protective member that covers the upper part of the outer component 42, and as shown in Figure 13, it is supported in the left-right direction Y across the extension 24 on the right side Y1 and the extension 24 on the left side Y2. In this state, the gap in a predetermined direction between the outer surface of the partition wall 52 described above and the back surface of the outer component 42 is hidden when viewed from above Z1, making it more difficult for the foreign matter described above to enter the gap from above Z1.

[0074] As shown in Figure 14, the protective cover 70 is formed in a roughly rectangular plate shape. Outward-projecting protrusions 71 are formed at both the left and right ends of the protective cover 70. As shown in Figure 15, the protective cover 70 is fixed to the case body 10 by inserting each protrusion 71 into fixing holes 25 formed in the extension portion 24. With this configuration, the protective cover 70 can prevent, for example, foreign objects that fall from above the cover body 50 from coming into contact with the outer parts 42, and prevent such foreign objects from moving towards the gap in a predetermined direction between the outer surface of the partition wall 52 and the back surface of the outer parts 42. Therefore, contact of foreign objects with the inner parts can be further suppressed. [Explanation of Symbols]

[0075] X Front-rear direction (predetermined direction) Y: Left-right direction (orthogonal direction) Z in the height direction (plate thickness direction) 1 Electronic equipment 10 Case body 11 Bottom plate 19 Support piece 27 1st wall 28 Second wall section 29 First locking section 29a First elastic piece (elastic piece) 29b 1st holding claw (holding claw) 40 Circuit boards 41 circuit boards 42 External parts 45 First end surface 45a 1st cutting surface 50 Cover Body 51 Top plate 52 Partition wall (side wall) 59 Cover side wall

Claims

1. An electronic device comprising: a case body having a bottom plate and opening in a direction opposite to the bottom plate; a circuit board housed in the case body; and a cover body covering the opening of the case body, The case body is provided with side walls that rise from the bottom plate, The side wall has a first side wall and a second side wall that are opposite to each other. The circuit board has a first end face that extends in a predetermined direction opposite to the inner surfaces of the first side wall and the second side wall, respectively. At least a portion of the first end face is provided with a first cutting surface formed at a predetermined position by cutting along the predetermined direction, A portion of the side wall is provided with an elastic piece formed by cutting out the side wall in the thickness direction and which is elastically deformable in the thickness direction, and a retaining claw protruding from the elastic piece toward the first cutting surface. The circuit board is held in the case body by the first cutting surface being locked to the retaining claw and pressed inward in an orthogonal direction perpendicular to the predetermined direction. The circuit board has a third end face that extends opposite to the inner surface of the first side wall and the inner surface of the second side wall at a position different from the first end face, and the third end face is an uncut surface. The distance between the first end face and the inner surface of the first side wall is smaller than the distance between the third end face and the inner surface of the first side wall, and An electronic device characterized in that the distance between the first end face and the inner surface of the second side wall is smaller than the distance between the third end face and the inner surface of the second side wall.

2. The circuit board has a second end face having a portion that is perpendicular to the first end face and extends in the orthogonal direction, and at least a part of the second end face is provided with a second cut surface formed at a predetermined position by cutting along the orthogonal direction. The electronic device according to claim 1, characterized in that the circuit board is positioned on the case body by the second cutting surface contacting or being in close proximity to a part of the case body.

3. The electronic device according to claim 2, characterized in that the side wall has a rib that protrudes inward from the case body, and the side surface of the rib and the second cutting surface are in contact with or close to each other.

Images