JP5286345B2 - Waterproof metal case and method for manufacturing waterproof metal case - Google Patents

Description

  The present invention relates to a waterproof metal case and a method for manufacturing a waterproof metal case.

Electrical components, electrical boards, electronic circuits, etc. (hereinafter collectively referred to as “electrical components etc.”) are stored in a metal case made of sheet metal, and a liquid or jelly-like resin is filled into the metal case and cured. Thus, it is known to place an electrical component in a resin-encapsulated state so as to insulate the electrical component, prevent water wetting or condensation, and improve heat retention or heat dissipation.
In this type of metal case, it is necessary to prevent the resin from leaking out when the resin is filled, and therefore it is necessary to have a waterproof property. Therefore, in the past, the blanks punched by press processing (the unfolded base plate before assembling the case) are folded into a case shape, and then in a separate process, the side plates are brought into contact with each other on the inside of the corner of the case. A method of applying a resin for weathering and drying (curing) it has been employed (see, for example, Patent Document 1).

  In the stamping of press work, the “sink”, “shear surface”, “fracture surface”, “burr” from the side where the punch for punching comes into contact with the outer peripheral edge (end face) of the blank along the thickness direction. Is known to occur. In addition, it is generally known that the ratio of the “shear surface” can be increased as much as possible in order to finish the blank outline beautifully and to increase the dimensional accuracy (see, for example, Patent Documents). (See 2nd grade).

Japanese Patent Laid-Open No. 10-209649 (FIGS. 1, 3, and 4) JP-A-4-348806 ([0003])

Conventionally, when manufacturing a waterproof metal case, the method of applying and drying the weathering resin on the side plate contact portion in the corner of the case is troublesome and requires drying time. There was a problem of significantly reducing the production efficiency. There is also a problem that the cost increases due to the use of the resin for weathering.
Even if the ratio of the “shear surface” generated on the outer peripheral edge (end surface portion) of the blank is increased, the blank outer shape is beautifully finished and the dimensional accuracy is made high (the entire end surface portion is formed by the shear surface, etc.) Needless to say, no matter how high the accuracy, the metal case formed from this blank cannot be waterproofed.

  The present invention has been made in view of the above circumstances, and it is possible to provide a metal case with waterproofness without applying a lining resin to the inside of the corners of the case. It is an object of the present invention to provide a waterproof metal case that can be manufactured at low cost and a method for manufacturing the waterproof metal case.

In order to achieve the above object, the present invention has taken the following measures.
That is, the waterproof metal case according to the present invention includes a bottom plate and a plurality of side plates that rise along the outer periphery of the bottom plate, and the corners of the outer periphery of the bottom plate include side plates and side plates that are adjacent to each other. In the metal case in which the portion is formed, the case corner is provided with a rupture mark generated with unevenness on the end surface portion in a state where the end surface portion of one side plate and the plate surface of the other side plate are in contact with each other. The present invention is characterized in that the plate surface is provided with a consolidation joint formed by being plastically deformed while being deformed.

  In this case, “adapted while plastically deforming” means that the fracture mark (particularly the convex part of the irregularity) and the plate surface generated with unevenness on the end face part are strongly pressed against each other, so that the fracture mark is crushed. In addition, it is in a state where it is extended or bites into the plate surface, and in some cases, the plate surface side is in a state of being recessed and deformed in accordance with the fracture mark, and as a result, the end surface portion and the plate surface are in close contact with each other in a watertight manner Say that will result.

  Further, here, the “consolidation joint portion” refers to a state in which the end surface portion of one side plate and the plate surface of the other side plate are in contact with each other while maintaining a “watertight contact state”. In addition, when filling a liquid or jelly-like resin into a metal case, the above-mentioned “watertight adhesion state” is the time until the resin filled in the metal case is cured in the case (30 to 120 minutes). The degree of contact) to the extent that it does not leak out of the case.

In this way, by having a structure in which a consolidation joint is provided at the corner of the case, it is possible to make the metal case waterproof without having to apply the resin for the inside of the corner of the case. Can do. Accordingly, a waterproof metal case can be manufactured with high efficiency and low cost.
The plurality of side plates are provided on the entire outer periphery of the bottom plate, and in a case surrounded by the side plates, a resin reservoir is formed on the lower side closer to the bottom plate in the height range in which the side plate rises from the bottom plate. A non-reservoir area is formed on the upper side from the resin reservoir, and the consolidation joint may be provided corresponding to the resin reservoir.

In short, when the resin is filled in the metal case, it is only necessary to provide a consolidation joint corresponding to the filling amount (reserved height) of the resin.
On the other hand, the method for manufacturing a waterproof metal case according to the present invention includes a bottom plate and a plurality of side plates that rise along the outer periphery of the bottom plate, and the side plate and the side plate that are adjacent to each other at the corners of the outer periphery of the bottom plate. In the method of manufacturing a metal case having a case corner formed by the above method, when punching out the blank of the metal case, a shear surface generated in the thickness direction of the end surface portion of one side plate of the case corner is formed. The side plate and the case where the end surface portion with a fracture mark is punched in such a manner that an end surface portion with a fracture surface is formed in which the fracture surface is equal to or greater than the shear surface in a relative ratio between the surface and the fracture surface with unevenness When bending the other side plate from which the corner is formed from the blank, the end surface portion is pressed against the end surface portion of the side plate on which the end surface portion with the fracture mark is formed. Flip was while breaking traces to form a compacted junction to the case corner portion by making them familiar with plastic deformation on the plate surface, characterized in that assembling the blank to the casing shape.

When punching out the blank, the side plate that generates the end surface portion with the breakage mark is more than the assembly dimension when the unevenness due to the breakage mark is brought into contact with the plate surface of the other side plate that forms the case corner. It is good to form as what protruded outside the dimension.
When the side plate having the end surface portion with the rupture marks and the other side plate of the case corners are bent from the blank, the side plate having the end surface portion with the rupture marks is first and the other side plate is the rear. It is preferable to cause a difference in bending timing so that the plate surface of the other side plate is pressed against the end plate with respect to the side plate on which the end surface portion with the breakage mark after being raised is formed.

  In the waterproof metal case and the waterproof metal case manufacturing method according to the present invention, the metal case can be waterproofed without applying the lining resin to the inside of the corner of the case. Therefore, it can be manufactured with high efficiency and low cost.

It is the perspective view which showed 1st Embodiment of the metal case with waterproofness which concerns on this invention. It is the top (development) figure which showed the blank of the metal case (the unfolded base plate before assembling the case). It is the sectional view on the AA line of FIG. It is the top view which showed the die | dye of the bending press apparatus used for manufacture of a metal case. 4A is a cross-sectional view of the principal part of the bending press apparatus shown corresponding to the line BB in FIG. 4, and FIG. 4B is a cross-sectional view of the bending press apparatus corresponding to the line CC in FIG. 4. It is principal part sectional drawing. It is the sectional side view which showed the state which bent the blank with the bending press apparatus used for manufacture of a metal case.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a first embodiment of a waterproof metal case 1 according to the present invention. As shown in FIG. 1, the metal case 1 includes a bottom plate 2 and a plurality of side plates 3, 3, 4, 4 that rise along the outer periphery of the bottom plate 2. Then, the case corner 5 is formed by the side plate 3 and the side plate 4 which are adjacent to each other.

  In the first embodiment, the bottom plate 2 is formed in a rectangular shape, and the side plates 3 and 4 are provided on the entire outer periphery (four sides) of the bottom plate 2 so that there are four side plates 3 and 4 in total. Further, the side plates 3 and 3 provided along the short side of the bottom plate 2 and the side plates 4 and 4 provided along the long side of the bottom plate 2 are also formed in a rectangular shape. As a whole, an elongated box shape without a lid is shown.

  In this metal case 1, the case corner 5 is formed by the end surface portion of one side plate 3 and the plate surface of the other side plate 4 coming into contact with each other. Further, a consolidation joint 7 is provided at the corner 5 of the case. The consolidation joint 7 is where the side plates 3 and 4 are brought into close water-tight contact. That is, the waterproofness is maintained in the case corner 5 where the consolidation joint 7 is provided.

If the metal case 1 is viewed by paying attention to the short side portion of the bottom plate 2, one side plate 3 is sandwiched from both sides by the other side plate 4. One side plate 3 will be referred to as “intermediate side plate 3”, and the other side plate 4 will be referred to as “enclosure side plate 4”.
In the first embodiment, the consolidation joint portion 7 is formed in a position that is lower than the height at which the intermediate side plates 3 and 3 and the outer side plates 4 and 4 rise from the bottom plate 2 and close to the bottom plate 2. It is as a thing. This means that the metal case 1 is provided with the consolidation joint 7 corresponding to only the depth where waterproofness is required.

  That is, in the case where electrical parts and the like are stored in the metal case 1 and filled with resin and cured (the electrical parts and the like are in a resin-enclosed state), the height range in which the side plates 3 and 4 rise from the bottom plate 2 The resin storage part is formed on the lower side near the bottom plate 2, and a non-storage area (a space in which air is stored) is formed on the upper side of the resin storage part. Therefore, the consolidation joint portion 7 is provided only for the resin storage portion that requires waterproofness.

Needless to say, the height of the resin storage portion in the metal case 1 is variously changed according to the size and arrangement of the electrical components to be stored, the size in the case, and the like. Therefore, the consolidation joint 7 can be made higher or lower, or can be variously changed according to the implementation situation.
In order to provide the consolidation joint 7, as shown in FIG. 2, when the blank 10 of the metal case 1 is formed by stamping, the intermediate side plate 3 is brought into contact with the outer side plate 4. A region in which breakage marks with unevenness are remarkably generated (hereinafter referred to as “breakage mark generation part 11”) is formed in the end face part 3a. Needless to say, the fracture mark generating part 11 in the end face part 3 a is a part forming the consolidation joint 7.

  That is, by strongly pressing the breakage mark generated in the breakage mark generating part 11 and the plate surface of the outer side plate 4, the unevenness (particularly the convex part) of the breakage mark is crushed and extended, Or it will be in the state which bites into a board surface. In this way, the fracture mark of the end surface portion 3a is adapted to the plate surface of the outer side plate 4 while being plastically deformed. At this time, the plate surface of the outer side plate 4 may also have a dent deformation that fits into the fracture mark. By these plastic deformations, the end surface portion 3a of the intermediate side plate 3 and the plate surface of the outer side plate 4 are in watertight contact with each other, and the waterproof joint 7 having waterproofness is formed.

  Here, as shown in FIG. 3, the breakage mark generating portion 11 is defined as “who 12 "" Shearing surface 13 "" Fracture surface 14 "" Burry (burr) 15 "comes to be generated. Of these, the proportion occupied by the fracture surface 14 is increased, which means a state in which many irregularities are generated. Shall. Furthermore, if the fracture surface 14 occupies a large proportion, the fracture surface 14 is equal to or greater than the shear surface 13 by the relative ratio of the shear surface 13 and the fracture surface 14. It shall be referred to as a “scratch generating part 11”.

  It should be noted that the assembly side plate 3 has the same assembling dimensions when contacting the plate surface of the outer enclosure side plate 4 (the opposing distance of the outer enclosure side plate 4 when the metal case 1 is used (= internal dimension on the short side)). ) Is the W dimension shown in FIG. 2, the portion where the fracture mark generating portion 11 is formed is larger than the assembly dimension (W) (W + α). Thus, the part ((alpha) / 2) protruded outside the dimension of the assembly dimension W shall be based on the unevenness | corrugation of the fracture | rupture trace in each end surface part 3a.

  Regarding the relationship between the specific ratio of the shear surface 13: fracture surface 14 and the specific protrusion amount (α / 2) in the irregularities of the fracture mark, and the waterproof action obtained based on these, the material of the blank 10 and It varies depending on the plate thickness (t), the height of the consolidation joint 7 and the like. For example, when the blank 10 is aluminum or an aluminum alloy, it is preferable that the shear plane 13: fractured surface 14 is 1: 1 to 1: 2, etc., and α / 2 is t / 20, etc. .

Next, a manufacturing method for manufacturing the metal case 1 will be described.
In order to manufacture the metal case 1, a punching process for punching the blank 10 (see FIG. 2) and a bending process for bending the blank 10 into a case shape are performed. Note that the punching process and the bending process may be performed by a single-shot method performed separately, or the punching process may be performed in a progressive manner and the bending process may be performed by a single-shot method.

In the punching step, as described with reference to FIG. 2, it is assumed that the breakage mark generating portion 11 is formed on the end surface portion 3 a of the intermediate side plate 3 in the blank 10. Further, in the intermediate side plate 3, the portion where the fracture mark generating portion 11 is formed is formed (W + α) so as to be larger than the assembly dimension (W).
In order to form the fracture mark generating portion 11, that is, to increase the ratio of the fracture surface 14 (see FIG. 3) in the end surface portion 3a, the clearance between the die and the punch in the punching press is increased, or the punching speed is increased. It can be realized by slowing down.

  For example, when the blank 10 is made of aluminum or an aluminum alloy, the clearance between the die and the punch is about 10% of the thickness of the blank 10 (the clearance is about 0.1 mm when the thickness of the blank 10 is 1.0 mm). Etc.). Increasing the clearance roughly means this level. However, if the material and thickness of the blank 10 are different, the degree of clearance is also changed.

4 to 6 show a bending press device 20 (single-shot type or progressive type) used for manufacturing the metal case 1. The pressing device 20 includes a die 21 formed in a frame shape so as to surround a case outer shape as the metal case 1, and a block-shaped punch 22 that fits inside the die 21 while maintaining the thickness of the blank 10. And have.
In the bending process using the press device 20, the intermediate side plate 3 and the outer side plate 4 are bent from the blank 10 and the blank 10 is assembled into a case shape. At the final stage of the bending, the breakage mark (breakage mark generation part 11) generated on the end surface part 3a of the intermediate side plate 3 is pressed against the plate surface of the outer side plate 4 to be adapted to plastic deformation and bite in some cases. I will let you.

  When the intermediate side plate 3 and the outer side plate 4 are bent from the blank 10, a difference is caused in the bending timing of the side plates 3, 4 so that the intermediate side plate 3 comes first and the outer side plate 4 comes later. preferable. That is, the intermediate side plate 3 rises first, and the outer side plate 4 is applied to the intermediate side plate 3 in this state. By doing in this way, the situation which pushes the unevenness | corrugation of the fracture | rupture trace (rupture trace generation | occurrence | production part 11) which arose in the end surface part 3a of the inside board 3 vertically with the board surface of the outer side board 4 is obtained.

Actually, in order to make a difference in the bending timing of the side plates 3 and 4, chamfering applied to the opposing edges of the die 21 and the punch 22 is performed on a portion corresponding to the intermediate side plate 3 (shown in FIG. 5B). In comparison, this can be realized by increasing the portion corresponding to the outer side plate 4 (shown in FIG. 5A). The chamfering may be a round chamfer as shown in the figure.
In some cases, in the die 21, the upper surface of the portion corresponding to the inner side plate 3 is raised and the upper surface of the portion corresponding to the outer side plate 4 is lowered. Bending timing can be set later.

  The extent of the difference in bending timing generated between the intermediate entry side plate 3 and the outer enclosure side plate 4 depends on the material of the blank 10, the plate thickness, and the like. If the blank 10 is aluminum or an aluminum alloy and the plate thickness is 1.0 mm, the outer side plate 4 with respect to the blank 10 is bent when the intermediate side plate 3 is bent about 30 ° with respect to the blank 10. It was preferable to start bending and continue bending the side plates 3 and 4 while maintaining the 30 ° angle difference therebetween. Making a difference in the bending timing of the side plates 3 and 4 means an angle difference of this degree.

  In the state of the blank 10 (see FIG. 2), the outer side plates 4, 4 are arranged on both sides of the intermediate side plate 3. Therefore, when the intermediate side plate 3 is bent from the blank 10, the lower end side of the intermediate side plate 3 is separated from the virtual line L with respect to the virtual line L that connects the end surface portions 4 a of the outer side plates 4 on both sides. Only the thickness t enters the bottom plate 2 side. Due to this, after bending into a case shape, a bulging portion that bulges outward from the case is formed at the lower end portion of the case corner portion 5 (in particular, the lower end portion of the intermediate side plate 3). become.

Therefore, as shown in FIG. 6, it is preferable that the die 21 is provided with a round chamfer 25 on the entire circumference in the die so as to press down the lower end portions of the inner side plate 3 and the outer side plate 4. It becomes.
In addition, the formation of the consolidation joint 7, the difference in bending timing, the prevention of the bulging portion at the case corner 5, the prevention of springback after bending the side plates 3, 4, the outer surface of the side plates 3, 4 In order to ensure damage prevention and the like, it has been confirmed that the blank 10 can be bent slowly by adjusting the lowering speed of the punch 22 with respect to the die 21 in the direction of decreasing the speed. .

Needless to say, it is particularly preferable to use striking (to form a projection edge on the outer peripheral portion of the punch 22 and apply local reduction) in order to prevent spring back.
As is clear from the above detailed description, in the present invention, the side plates 3 and 4 are bent from the blank 10 punched into a predetermined shape, and the breakage mark (breakage mark generation part 11) generated in the end surface part 3a of the intermediate side plate 3 is obtained. The metal case 1 having a waterproof property can be manufactured simply by pressing to the plate surface of the outer side plate 4 and plasticizing it. Naturally, since the metal case 1 manufactured in this way has waterproofness, it is not necessary to apply the resin for the eye-tightness to the inside of the case corner 5 one by one. Thus, the waterproof metal case 1 can be manufactured with high efficiency and low cost.

The present invention is not limited to the embodiment described above, and can be changed as appropriate according to the embodiment.
For example, in the metal case 1, it is not limited that the shape of the bottom plate 2 and the side plates 3 and 4 is a rectangle, and each may be a square or the like. Of course, the bottom plate 2 may be formed in a polygon other than a quadrangle. Further, the point that the side plates 3 and 4 are provided on the entire outer periphery of the bottom plate 2 is not particularly limited (if at least one case corner 5 can be formed). Good).

If the metal case 1 is filled with resin, the consolidation joint 7 is provided corresponding to the height of the inner side plates 3 and 3 and the outer side plates 4 and 4 (at the same height). It may be.
The metal case 1 may be used for purposes other than the purpose of encapsulating electrical components and the like with resin.

DESCRIPTION OF SYMBOLS 1 Metal case 2 Bottom plate 3 Side plate 3a End surface part 4 Side plate 4a End surface part 5 Case corner part 7 Consolidation junction 10 Blank 11 Break trace generation | occurrence | production part 13 Shear surface 14 Broken surface 20 Press apparatus 21 Die 22 Punch 25 Round chamfering W Assembly dimension

Claims (5)

In a metal case having a bottom plate and a plurality of side plates rising along the outer periphery of the bottom plate, and a corner of the outer periphery of the bottom plate is formed with a case corner by the side plate and the side plate adjacent to each other.
In the state where the end surface portion of one side plate and the plate surface of the other side plate are in contact with each other at the corner of the case, breakage marks generated with unevenness on the end surface portion are made to conform to the plate surface while being plastically deformed. A metal case having a waterproof property, characterized in that it is provided with a consolidation joint formed in the above manner. The plurality of side plates are provided on the entire outer periphery of the bottom plate, and in a case surrounded by the side plates, a resin storage portion is formed on a lower side closer to the bottom plate in a height range in which the side plate rises from the bottom plate. A non-reservoir area is formed on the upper side of the reservoir,
The waterproof metal case according to claim 1, wherein the consolidation joint portion is provided corresponding to the resin storage portion. In a method of manufacturing a metal case having a bottom plate and a plurality of side plates rising along the outer periphery of the bottom plate and having corners formed by side plates and side plates that are adjacent to each other at the corners of the outer periphery of the bottom plate,
When punching out the blank of the metal case, one of the side plates that form the corner of the case has a shear plane that is a relative ratio between the shear plane that occurs in the thickness direction of the end face and the fracture plane that has irregularities. Is punched in such a way that an end face with a fracture mark that is equal to or greater than is formed,
When the side plate having the end surface portion with the rupture marks and the other side plate of the case corners are bent from the blank, the other side plate is formed on the end surface portion of the side plate having the end surfaces with the rupture marks. The blank is formed into a case shape while forming a consolidation joint at the corner of the case by allowing the breakage marks generated on the end surface portion to conform to the plate surface while being plastically deformed as the plate surface is pressed. A method of manufacturing a waterproof metal case, characterized by being assembled. When punching out the blank,
The side plate that produces the end surface portion with the breakage mark protrudes outward from the assembly dimension when the unevenness due to the breakage mark is brought into contact with the plate surface of the other side plate that forms the case corner. 4. The method for producing a waterproof metal case according to claim 3, wherein the metal case is formed as a thing. When bending the side plate that produced the end surface portion with the breakage mark and the other side plate that forms the corner of the case from the blank,
Create a difference in the bending timing so that the side plate that produced the end surface portion with the rupture mark is the front and the other side plate is the rear,
5. The waterproof property according to claim 3, wherein the plate surface of the other side plate is pressed against the side plate on which the end surface portion with the fracture mark after the standing state is generated. A method of manufacturing a metal case having

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