METHOD FOR MANUFACTURING HOUSING BY PRESS WORKING, APPARATUS THEREFOR AND HOUSING THEREOF

Abstract

A flange part of a housing is shaped using a press working with a punch and a die, the housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and the flange part bent from an opening of the side wall part in the other side towards outside. In the press working, the punch is disposed in an internal space side of the housing and the die in an opposite side of the internal space side of the housing, and a crush working is performed to crush a bend part formed from the side wall part to the flange part, while drawing at least part of an outer peripheral surface of the side wall part towards a flange part side by using the die.

Claims

1. A method for manufacturing a housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and a flange part bent from an opening of the side wall part in the other side towards outside, using press working with a punch and a die for shaping the flange part, comprising steps of: disposing the punch in an internal space side of the housing and the die in an opposite side of the internal space side of the housing; performing, during the press working, crush working that crushes a bend part formed from the side wall part to the flange part, while drawing at least part of an outer peripheral surface of the side wall part towards a flange part side by using the die, thereby causing a radius of curvature of a portion in the bend part from an inner peripheral surface of the side wall part to the flange part, to be smaller and expanding a flat surface of the flange part in a punch side.

2. The method for manufacturing the housing using the press working according to claim 1, wherein in the crush working, a protrusion is provided on a surface of the punch opposite to the flange part, the protrusion restraining an outer peripheral end part of the flange.

3. A manufacturing apparatus for a housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and a flange part bent from an opening of the side wall part in the other side towards outside, using a press working for shaping the flange part, comprising: a punch disposed in an internal space side of the housing and formed corresponding to an inner shape of the housing from the bottom part to the flange part via the side wall part; and a die disposed in an opposite side of the internal space side of the housing and formed corresponding to an outer shape of the housing from the bottom part to the flange part via the side wall part, wherein for the punch and the die, side wall surfaces interposing the side wall part of the housing during the press working are each formed in a tapered shape such that the internal space is spread towards a flange part side; and at least part of side wall surfaces of the die has a straight shape extending straight from a tip end in the flange part side in a pressing direction by a prescribed length.

4. The manufacturing apparatus according to claim 3, wherein opposing surfaces of the punch and the die interposing the flange part of the housing during the press working each has a plane shape parallel to an opening surface of the housing; a protrusion of which the height is lower than a plate-thickness of the flange part is provided on the opposing surface of the punch; and the protrusion is configured to restrain an outer peripheral end part of the flange part during the press working.

5. A housing comprising: a side wall part surrounding an internal space; a bottom part that closes an opening of the side wall part in one side; and a flange part bent from an opening of the side wall part in the other side towards outside, wherein at least part of a bend part extending from the side wall part to the flange part is applied with a crush working, whereby a crush mark is present on at least part of a flange part side of an outer peripheral surface of the side wall part; the crush working is applied using a method for manufacturing a housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and a flange part bent from an opening of the side wall part in the other side towards outside, using a press working with a punch and a die for shaping the flange part, comprising steps of: disposing the punch in an internal space side of the housing and the die in an opposite side of the internal space side of the housing; performing, during the press working, a crush working that crushes a bend part formed from the side wall part to the flange part, while drawing at least part of an outer peripheral surface of the side wall part towards a flange part side by using the die, thereby causing a radius of curvature of a portion in the bend part from an inner peripheral surface of the side wall part to the flange part, to be smaller and expanding a flat surface of the flange part in a punch side.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a diagram showing a cross-sectional view of an internal configuration of electronic equipment of embodiments.

[0006] FIG. 2 is a diagram showing a perspective view of a housing in a casing of the electronic equipment when viewed from an internal space side.

[0007] FIG. 3 is a diagram showing a perspective view of a housing in a casing of the electronic equipment when viewed from a bottom side.

[0008] FIG. 4 is a diagram showing a cross-sectional view of a mold for primarily-forming the housing with a press working.

[0009] FIG. 5 is a diagram showing a cross-sectional view of a configuration of the mold used for shaping a flange part of the housing.

[0010] FIG. 6 is a diagram showing a change in a shape of the flange part caused by a crush working using the mold shown in FIG. 5.

[0011] FIG. 7 is a diagram showing a perspective view of a housing according to a modification example when viewed from an internal space side.

[0012] FIG. 8 is a diagram showing a perspective view of the housing according to the modification example when viewed from a bottom side.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] For example, for electronic equipment, a metal-made housing may be provided to cover a circuit board inside a casing for noise suppression. The housing is made of a conductive material such as by die casting, or a metal plate. The housing is configured to contact with a wiring pattern such as a ground pattern of the circuit board to cause the entire electronic equipment to be grounded, whereby noise produced by the circuit board can be prevented from radiating outside, or external noise can be prevented from entering inside thereof. Hence, for this type of the housing, a configuration is considered in which an opening in the circuit board side of a side wall part that surrounds periphery of the internal space is bent so as to form a flange part, whereby a contact area between the wiring pattern and the housing is expanded to enhance a noise suppressing effect.

[0014] On the other hand, patent literature JP-A-2001-314921 proposes a method for increasing a thickness of a bend part as a root part of the flange part formed vertically extending at an end portion of a plate-work, to be thicker than a plate thickness of a base material. According to the technique proposed by the above patent literature, the flange part is formed with an upsetting process to lower the height of the flange part using a die and a punching, thereby increasing the thickness of the bend part. Accordingly, when manufacturing the above-described housing, such a method of increasing the thickness is utilized to increase the thickness of the bend part at the root part of the flange part. Hence, a contact area with the wiring pattern of the circuit board is expanded, whereby the noise suppression effect can be enhanced.

[0015] According to the method for increasing the thickness described in the above-described patent literature, since an upsetting process is applied to the flange part to concentrate the material at the bend part, a wear amount of a mold component increases due to an increase in a processing load of the upsetting process, and may cause a breakage of the mold component.

[0016] Further, according to the above-described patent literature, a step is provided on a contact surface of the die with which the plate-work contacts such that the step is intruded to a portion in the vicinity of the bend part during the upsetting process, whereby the a movement of the material is partially restricted at the step during the upsetting process and an effect of increasing the thickness of the bend part is enhanced. However, such a configuration may produce a space in the bend part or a buckling due to the step. Moreover, in this case, since a stepped-shape remains on a product after the upsetting process is applied, a secondary formation needs to be performed to press a portion in the vicinity of the bend part such that the stepped-shape becomes flat. As a result, a problem arises that the number of manufacturing steps increases.

[0017] Hereinafter, with reference to the drawing, embodiments of the present disclosure will be described.

[0018] As shown in FIG. 1, electronic equipment 1 according to the present embodiment is, for example, mounted on a vehicle and used for transmitting and receiving electromagnetic waves. The electronic equipment 1 is provided with a circuit substrate 10 on which various electronic components that constitute a transmission and reception circuit are mounted.

[0019] The circuit substrate 10 is, for example, a printed circuit board having a rectangular shape and accommodated in a casing 3. The casing 3 is provided with a lower case 5 and an upper case 7. The lower case 5 covers, in the circuit substrate 10, a substrate surface 10A on which various electronic components are mounted and having a rectangular shape similar to that of the circuit substrate 10 so as to protect various electronic components. Then, the circuit substrate 10 is disposed to close the opening of the lower case 5, and fixed to an opening portion 5A of the lower case 5 by a screw 9.

[0020] The upper case 7 is configured to have a rectangular lid shape which is larger than the circuit substrate 10 so as to close the opening of the lower case 5 in a state of covering the circuit substrate 10 from an opposite side of the substrate surface 10A of the circuit substrate 10. The upper case 7 is fixed to an opening 5A of the lower case 5 in an outside the outer periphery part of the circuit substrate 10.

[0021] An inner case 20 is provided between the lower case 5 and the circuit substrate 10. The inner case 20 covers the substrate surface 10A of the circuit substrate 10 to prevent noise produced by the circuit board 10 from radiating outside, or prevent external noise from entering the circuit substrate 10. In other word, the inner case 20 is accommodated in the internal space 12 of the lower case 5 as a countermeasure of noise. Note that the inner case 20 corresponds to housing of the present disclosure.

[0022] The inner case 20 is made of metal containing conductive metal such as aluminum and provided with a side wall part 22 having an annular shape, surrounding a periphery part of the internal space 12 inside the lower case 5 and a bottom part 24 that closes an opening of the side wall 22 in one side. A portion opposite to the bottom part 24 of the side wall part 22 is opened. Hence, as shown in FIGS. 2 and 3, the inner case 20 has a container shape which is the same as that of the lower case 5.

[0023] Further, the opening of the side wall part 22 of the inner case 20 is bent towards outside through the entire periphery, thereby forming a flange part 26. The flange part 26 is used for electrically connecting the inner case 20 with a ground pattern provided on the substrate surface 10A of the circuit substrate 10, when the circuit substrate 10 is disposed on the opening part 5A of the lower case 5.

[0024] Specifically, the flange part 26 is electrically connected to the ground pattern as a reference potential of the circuit substrate 10, thereby maintaining the potential of the entire inner case 20 to be the reference potential. As a result, high frequency noise emitted from the electronic components or the wiring pattern of the circuit substrate 10 is absorbed by the inner case 20, and external noise produced in the vicinity of the electronic equipment 1 is reflected at the inner case 20 and prevented from entering the circuit substrate 10 side.

[0025] Moreover, a conductive layer as the reference potential is provided in an opposite side of the substrate surface 10A of the circuit substrate 10, serving as a solid ground pattern. With this conductive layer, noise entering the circuit substrate 10 or noise radiating from the circuit board is suppressed.

[0026] For the inner case 20, a bend part 28 formed from the side wall part 22 to the flange part 26 is caused to contact with the circuit substrate 10, whereby the inner case 20 is connected to the ground pattern of the circuit substrate 10. Hence, for the noise suppression, a contact area between the bend part 28 and the circuit substrate 10 is required to be expanded in order to prevent high frequency noise from being leaked from a portion between the bend part 28 and the circuit substrate 10.

[0027] In this respect, for the inner case 20 according to the present embodiment, an upper mold 30A and a lower mold 30B exemplified in FIG. 4 are used to perform a drawing applied to a metal plate with a press-working, thereby performing a primary molding for the above-described inner case 20 having a container shape. Then, with a press working using a punch 32 and a die 34 exemplified in FIG. 5, a crush working is applied to the bend part 28 formed from the side wall part 22 to the flange part 26 of the primary-molded inner case 20.

[0028] With the crush working, a radius of curvature of a corner portion in the bend part 28 from an inner peripheral surface of the side wall part 22 to the flange part 26 becomes small, and an area of a flat surface of the flange part 26 that contacts with the circuit substrate 10 is expanded. Accordingly, a region from the bend part 28 at a root part of the flange part 26 to the flange part 26 is shaped by the crush working.

[0029] Next, the punch 32 and the die 34 used for the crush working will be described.

[0030] As shown in FIG. 5, the punch 32 is formed corresponding to a product shape of the inner case 20, extending in the internal space 12 side of the inner case 20 (hereinafter referred to as inner side), from the bottom part 24 of the inner case 20 to the flange part 26 via the side wall part 22. Then, during the crush working, the punch 32 is disposed inside the inner case 20 along the side wall part 22 of the inner case 20.

[0031] The die 34 is formed corresponding to a product shape of the inner case 20 extending in an outside opposite to the internal space 12 of the inner case 20, from the bottom part 24 of the inner case 20 to the flange part 26 via the side wall part 22. Then, during the crush working, the die 34 is disposed outside the inner case 20, interposing the side wall part 22 of the inner case 20 between the die 34 and the punch 32.

[0032] For the punch 32 and the die 34, the side wall surfaces 32A and 34A interposing the side wall part 22 of the inner case 20 during the crush working are formed in a tapered shape inclined by a predetermined angle with respect to a pressing direction such that the internal space 12 of the inner case 20 is spread towards the flange part 26 side.

[0033] Further, the side wall surface 34A of the die 34 has a straight shape extending straight from a tip end in the flange part 26 side in the pressing direction by a prescribed length H. Then, during the crush working, the punch 32 and the die 34 are disposed such that an interval T between the side wall surfaces 32A and 34A is the same as a plate thickness of the side wall part 22.

[0034] Further, according to the punch 32, a protrusion 32C of which the height is lower than the plate thickness of the flange part 26 is provided at the bottom surface 32B to which the flange part 26 of the inner case 20 contacts so as to interpose the flange part 26 between the punch 32 and the die 34. Note that the protrusion 32C is for positioning an outer peripheral end part of the flange part 26 during the crush working and restraining the outer peripheral end part of the flange part 26.

[0035] Next, with reference to FIG. 6, a change in the shape of the inner case 20 when shaping the flange part 26 of the inner case 20 using a manufacturing apparatus including thus configured punch 32 and die 34 will be described. In FIG. 6, the most left side chart illustrates a state before the processing starts, the most right side chart illustrates a state at which the processing ends and two charts in the middle each illustrates a change in the shape of the inner case 20 caused by a movement of the die 34 with respect to the punch 32.

[0036] As shown in FIG. 6, before staring the processing, the inner case 20 is placed on the punch 32 such that the punch 32 is inserted to the internal space 12 of the inner case 20. Then, a material pressing member 36 indicated by a dotted line in FIG. 6 is placed on the bottom part 24 of the inner case 20, and the bottom part 24 of the inner case 20 is positioned between the material pressing member 36 and the punch 32. As a result, the bottom part 24 can be prevented from being deformed during the processing.

[0037] Next, once the press working starts with the above-described state, the die 34 moves in the pressing direction with respect to the punch 32, a corner part 34B of the die 34 in the punch 32 side comes into contact with the side wall part 22 of the inner case 20. Then, when the die 34 moves, the side wall part 22 is drawn by the corner portion 34B of the side wall part 22. As a result, a part of the meal material of the inner case 20 moves towards the bend part 28 side as indicated by a black arrows shown in FIG. 6.

[0038] The movement of the metal material also occurs towards a tip end side of the flange part 26 from the bend part 28, but the outer peripheral end part of the flange part 26 is restrained by the protrusion 32C. Hence, the metal material is reliably filled at a corner portion at which the side wall surface 32A and the bottom surface 32B of the punch 32 cross each other. Then, surplus metal material which is not filled at the corner portion moves towards outside from a gap between the protrusion 32C of the punch 32 and the die 34.

[0039] Thus, the punch 32 and the die 34 are utilized for performing the press working, whereby a region 22A in the bottom part 24 side shown in FIGS. 2 and 3 is formed as a tapered shape having an inclination angle which is the same as those in the punch 32 and the die 34.

[0040] Moreover, in the side wall part 22 of the inner case 20, a crush working is applied to a region 22B in the flange part 26 side shown in FIGS. 2 and 3 by a drawing of the die 34. As a result, despite a mark of the drawing remaining at an outer peripheral surface of the region 22B, the thickness of the bend part 28 of the inner case 20 increases. Then, since the thickness of the bend part 28 increases, a radius of curvature of the corner portion in the internal space 12 side of the bend part 28 becomes smaller and a surface opposite to the circuit substrate 10 is expanded in the flange part 26 of the inner case 20.

[0041] Therefore, the inner case 20 according to the present embodiment is utilized as a housing for noise suppression of the circuit substrate 10 exemplified in FIG. 1, whereby a contact area between the housing and the wiring pattern of the reference potential of the circuit substrate is expanded and the effect of suppressing noise can be enhanced.

[0042] Also, for the press working shown in FIG. 6 (i.e. crush working), it is not required to compress the flange part 26 in the longitudinal direction like the upsetting process. Hence, the press working can be performed in a state where a tip end part opposite to the bend part 28 of the flange part 26 is opened.

[0043] Accordingly, for a manufacturing method or an apparatus for the inner case 20, a processing load applied to the flange part 26 can be reduced compared to a case where the upsetting process is performed, and with the reduced processing load, a wear amount of a mold component can be prevented from increasing.

[0044] One embodiment of the present disclosure has been described above. The present disclosure is not limited to the above-described embodiment, but may be modified in various manners.

[0045] For example, according to the above-described embodiments, as shown in FIGS. 2 and 3, it is described that the inner case 20 as an example of the housing of the present disclosure has an annular side wall part 22 that surrounds periphery of the internal space 12, and the bottom part 24 having a flat plate shape. However, as shown in FIGS. 7 and 8, the side wall part 22 and the bottom part 24 of the inner case 20 may be configured to have a hollow part, a concave part or a convex part corresponding to an arrangement or a shape of the electronic components mounted on the circuit substrate 10.

[0046] In this case, the crush working cannot be performed for the entire area of the flange part 26 of the inner case 20 by using the punch 32 and the die 34 shown in FIG. 5. Accordingly, in this case, for example, as indicated by hatching in FIGS. 7 and 8, a crush working process may be performed for a region as a processing region where the side wall part 22 has a straight shape and the press working using the punch 32 and the die 34 can be applied. Also with this configuration, a contact area with the circuit substrate 10 at the flange part 26 corresponding to the processing region is expanded, and the effect of suppressing noise can be enhanced.

[0047] In the above-described embodiment, it is described that the housing before the crush working is applied, that is, the inner case 20, is press-shaped using the above-described upper mold 30A and lower mold 30B. However, as shown in FIGS. 7 and 8, in the case where the inner case 20 has complicated shape, a plurality of molds may be used corresponding to the shape of the inner case 20 for primarily-forming the metal plate before the crush working is applied. Alternatively, a plurality of molds may be used and may perform a plurality of press-shaping such as a drawing.

[0048] Next, according to the above-described embodiments, in FIG. 5, the inclination angle is set to be relatively larger in order to readily recognize the tapered shape of the side wall surfaces 32A and 34A of the punch 32 and the die 34. This inclination angle may be about 0.1 degree. Specifically, even when the inclination angle is set to be about 0.1 degree, the thickness of the bend part 28 as a root portion of the flange part 26 of the inner case 20 increases such that the contact area between the flange part 26 and the circuit substrate 10 can be expanded.

[0049] Also, according to the above-described embodiments, in order to fill the metal material at the corner portion at which the sidewall part 32A and the bottom surface 32B cross each other by the crush working, the protrusion 32C is provided at the bottom surface 32B of the punch 32 for restraining the outer peripheral end part of the flange part 26.

[0050] However, depending on the shape of the punch 32 and the die 34 or types of metal material that constitute the inner case 20, even without protrusion 32C, by using the crush working, the metal material may be filled at the corner portion at which the sidewall part 32A and the bottom surface 32B cross each other. In this case, the protrusion 32C is not necessarily provided.

[0051] Moreover, according to the present embodiment, as an example of the present disclosure, an inner case 20 is exemplified for a noise suppression, being accommodated in the lower case 5 made of synthetic resin together with the circuit substrate 10. However, the housing of the present disclosure may be disposed outside the electronic equipment 1 and utilized as a casing that protects the electronic equipment 1.

(Conclusion)

[0052] According to a first aspect of the present disclosure, without performing an upsetting process for a flange part bent from an opening of a housing towards outside, a thickness of a bend part at a root part of the flange part can be increased.

[0053] One embodiment of the present disclosure is a manufacturing method in which a flange part of a housing is shaped using a press working with a punch and a die, the housing including a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and the flange part bent from an opening of the side wall part in the other side towards outside.

[0054] According to the manufacturing method of the present disclosure, the punch is disposed in an internal space side of the housing and the die in an opposite side of the internal space side of the housing. Then, with the press working, a crush working is performed to crush a bend part formed from the side wall part to the flange part, while drawing at least part of an outer peripheral surface of the side wall part towards a flange part side by using the die.

[0055] As a result, a part of the material of the flange part moves to the bend part as a root part of the flange part, the thickness of the bend part increases, a radius of curvature of a portion in the bend part from an inner peripheral surface of the side wall part to the flange part becomes small, and an area of a flat surface in the punch side of the flange part is expanded.

[0056] Hence, according to a manufacturing method of the housing of the present disclosure, without performing an upsetting process disclosed by the above-described patent literature, a crush working is performed, thereby increasing the thickness of the bend part as a root part of the flange part in the housing so as to expand the flat surface in the punch side of the flange part.

[0057] Further, the crush working does not require to compress the entire flange part in the longitudinal direction like the upsetting process, thus the crush working can be performed in a state of opening the tip end part opposite to the bend part of the flange part. Hence, according to the manufacturing method of the housing of the present disclosure, compared to a case where an upsetting process is performed, a processing load applied to the flange part can be reduced and a wear amount of a mold component can be prevented from increasing due to the processing load.

[0058] One aspect of the present disclosure is a manufacturing apparatus for shaping the flange part of the above-described housing by using the above-described method. The manufacturing apparatus is provided with a punch and a die for the above-described press working.

[0059] The punch is disposed in the internal space side of the housing and formed corresponding to an inner shape of the housing extending from the bottom part to the side wall part. Further, the die is disposed in a portion opposite to the internal space of the housing and formed corresponding to an outer shape of the housing extending from the bottom part to the side wall part.

[0060] For the punch and the die, side wall surfaces interposing the side wall part of the housing during the press working are each formed in a tapered shape such that the internal space is spread towards a flange part side, and at least part of side wall surfaces of the die has a straight shape extending straight from a tip end in the flange part side in a pressing direction by a prescribed length.

[0061] According to the manufacturing apparatus of the present disclosure, the punch is disposed in the internal space of the housing such that the side wall surfaces are overlapped, and the die is caused to move towards the punch from the bottom part of the housing, whereby the press working can be applied to the flange part of the housing.

[0062] Then, when the die is caused to move during the press working, since the outer side wall surface of the side wall part of the housing is drawn at a straight part of the die, a part of the side wall part of the housing is caused to move towards the bend part side as a root portion of the flange part, the thickness of the bend part increases, and the flat surface in the punch side of the flange part is expanded.

[0063] Hence, according to the manufacturing apparatus of the present disclosure, the flange part of the housing can be shaped using the above-described method, and similar effects and advantages to those in the above-described manufacturing method can be obtained.

[0064] One aspect of the present disclosure is a housing of which the flange part is shaped by a press working using the above-described. The housing is provided with a side wall part surrounding an internal space, a bottom part that closes an opening of the side wall part in one side and a flange part bent from an opening of the side wall part in the other side towards outside.

[0065] Moreover, at least part of a bend part extending from the side wall part to the flange part of the housing is applied with a crush working according to the above-described manufacturing method, whereby a crush mark is present on at least part of a flange part side of an outer peripheral surface of the side wall part.

[0066] According to the housing of the present disclosure, a radius of curvature of the bend part the in the internal space side of flange part becomes small and a flat surface opposite to the bottom part of the flange part is expanded. Hence, the housing of the present disclosure is provided on the circuit substrate of electronic equipment to suppress noise, whereby a contact area between the housing and a wiring pattern of the circuit substrate is expanded to enhance the noise suppression effect.