JP2008232159A - Manufacturing method for base material integrated type seal structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide seal structure manufactured inexpensively, in which base material and a gasket are surely integrated. <P>SOLUTION: For molding the gasket, the base material 2 having a gasket retaining groove 21 and a raised part raised from groove shoulders to the outside of the groove is molded, the raised part is crashed by a metallic mold 3 for molding a gasket to plastically deforming a part of the raised part to be protruded from inside face 21a of the gasket retaining groove 21, and a cavity 5 defined by the inside face of the gasket molding metallic mold 3 and the gasket retaining groove 21 is filled with molding rubber material. Since the protruded part formed by crashing the raised part 22 functions as an undercut for restraining the gasket molded in the cavity 5 in the gasket retaining groove 21, the seal structure in which the gasket is integrated to the base material 2 is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing method of a base material integrated seal structure used as a sealing means for a case of a precision device such as a small portable terminal device, an HDD, or a power device.

  Small mobile terminal devices such as mobile phones are provided with a seal structure that integrates a gasket made of rubber-like elastic material on the mating surface of the outer shell case to prevent dust and water from entering the machine. ing.

  FIG. 11 is a cross-sectional view showing a sealing structure of an outer shell case of a precision instrument according to the prior art, that is, this type of sealing structure 100 is a pair of synthetic resin base materials constituting the outer shell case and the like. A gasket holding groove 101a that is continuous in an endless manner along the outer periphery is formed on the mating surface of one base material 101 with the other base material (not shown), and a rubber-like elastic material is formed in the gasket holding groove 101a. The gasket 102 made of is integrally molded.

As a seal structure in which a gasket made of a rubber-like elastic material is provided in a groove formed in a base material made of a synthetic resin or the like, one described in Patent Document 1 below is known.
Japanese Patent Laid-Open No. 2005-3181

  Here, in order to integrally form the gasket 102 made of a rubber-like elastic material in the gasket holding groove 101a formed in the base material 101, a rubber having adhesiveness (self-adhesiveness) to the base material 101 made of synthetic resin. A molding material is used, or an adhesive is applied to the inner surface of the gasket holding groove 101a, and a rubber molding material having no adhesion to a synthetic resin is used for molding the gasket 102. A method may be considered in which the inner surface of the holding groove 101a is adhered, or the gasket holding groove 101a is formed in an undercut shape capable of restraining the gasket 102 and is molded with a rubber molding material having no adhesion to the synthetic resin. .

  However, in the case of using a rubber molding material having adhesiveness to the synthetic resin, the synthetic resin material used for molding the base material 101 and the self-adhesive rubber material used for molding the gasket 102 are considered in terms of adhesion compatibility. There is a problem that material selection is significantly restricted.

  Further, in the method of bonding the gasket 102 to the inner surface of the gasket holding groove 101a simultaneously with the molding of the gasket 102 using an adhesive, a step of applying an adhesive to the inner surface of the gasket holding groove 101a is required, which is manufactured. There is a problem that the cost becomes high.

  Further, when the gasket 102 is integrated by an undercut provided in the gasket holding groove 101a, there is a problem that it becomes difficult or impossible to mold the base material 101 with a mold.

  The present invention has been made in view of the above points, and the technical problem is that it can be manufactured at a low cost, and the base material and the gasket are reliably integrated. It is to obtain a seal structure.

  As a means for effectively solving the technical problem described above, the manufacturing method of the base material integrated seal structure according to the invention of claim 1 includes a gasket holding groove and a protruding portion protruding from the groove shoulder to the groove outer side. A step of forming a base material having, a step of crushing the raised portion and plastically deforming so as to protrude from an inner surface of the gasket holding groove, and a gap between the inner surface of the gasket molding die and the gasket holding groove. And forming a gasket by filling the cavity with a molding rubber material.

  According to the above configuration, the protruding portion is then deformed by crushing the protruding portion protruding from the groove shoulder of the gasket holding groove formed on the base material toward the outer side of the gasket so as to protrude from the inner surface of the gasket holding groove. Since the gasket formed by filling the cavity between the inner surface of the gasket molding die and the gasket holding groove with the molding rubber material becomes an undercut that restrains the gasket holding groove, the gasket becomes the base material. An integrated seal structure is obtained.

  The manufacturing method of the base material integrated seal structure according to the invention of claim 2 is the method of claim 1, wherein the bulging portion is crushed by a gasket molding die. This eliminates the need for a dedicated jig or process for crushing the raised portion, and crushing the raised portion is performed in the process of clamping the mold for gasket molding.

  According to a third aspect of the present invention, there is provided a method for manufacturing a base material integrated seal structure according to the second aspect, wherein the gasket molding die is caused to direct plastic deformation caused by crushing of the raised portion into the gasket holding groove. A slope or a step surface is formed. In this way, an undercut due to plastic deformation of the raised portion is reliably formed.

  According to the method for manufacturing a base material integrated seal structure according to the present invention, the base material integrated seal structure can be manufactured at a low cost, and is protruded from the groove shoulder of the gasket holding groove in the base to the groove outer side. Crushing the raised ridges and plastically deforming a part thereof into the gasket holding groove, and then undercutting the gasket formed in the cavity between the gasket molding die inner surface and the gasket holding groove; Therefore, a sealing structure in which the base material and the gasket are integrated can be manufactured without using a rubber molding material having adhesiveness to the synthetic resin or an adhesive.

  Further, the crushing of the raised portion is performed in the process of clamping the gasket molding die, thereby preventing an increase in manufacturing cost.

  In addition, by forming a slope or a step surface that directs plastic deformation due to crushing of the raised portion into the gasket holding groove in the gasket molding die, an undercut due to plastic deformation of the raised portion is reliably formed. Product reliability can be improved.

  Hereinafter, preferred embodiments of a method for producing a base material integrated seal structure according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a process of forming a base material, FIG. 2 is a cross-sectional view showing a state where the base material is set in a gasket molding die, and FIG. FIG. 4 is a cross-sectional view showing a step of plastically deforming so as to protrude from the inner surface of the gasket holding groove, FIG. 4 is a cross-sectional view showing a step of molding a gasket, and FIG. 5 is a substrate-integrated seal manufactured by this manufacturing method. It is sectional drawing which shows a structure.

  First, in FIG. 1, reference numeral 1 is a base material molding die having a lower die 11 and an upper die 12. In a cavity defined between the lower die 11 and the upper die 12 by clamping, The substrate 2 is molded by filling a molding resin material. As the resin material for molding, for example, PA (polyamide), PPS (polyphenylene sulfide), PEEK (polyether ether ketone), PP (polypropylene), PE (polyethylene), POM (polyacetal), PI (polyimide), PET ( It is selected from thermoplastic resins such as polytetrafluoroethylene), PBT (polybutylene terephthalate), and PC (polycarbonate).

  The base material 2 molded by the base material molding die 1 corresponds to one case member constituting an outer shell case of a mobile phone, for example, and is a mating surface with the other case member (not shown). 2a has a gasket holding groove 21 which is endlessly continuous along the outer periphery, and a raised portion 22 having a substantially U-shaped cross section which protrudes from the groove shoulders on both sides to the groove outer side. Since the gasket holding groove 21 has a simple cross-sectional shape and does not have an undercut portion, it can be easily released.

  The base material 2 taken out from the base material molding die 1 is set in a gasket molding die 3 as shown in FIG. The gasket molding die 3 has a lower die 31 for fixing the base material 2 and an upper die 32 that can be moved forward and backward with respect to the mating surface 2a of the base material 2 and is clamped so as to close the gasket holding groove 21. It is what is done. The upper mold 32 is formed with a seal lip molding surface 32 a on the surface facing the gasket holding groove 21.

  Next, when the gasket molding die 3 is clamped as shown in FIG. 3, the pressing surfaces 32 b and 32 b on both sides of the seal lip molding surface 32 a in the upper mold 32 are raised in the base 2 in the process. The parts 22 and 22 are pressed and crushed. For this reason, the crushed raised portions 22 and 22 are plastically deformed so that a part thereof protrudes from the inner side surfaces 21 a and 21 a of the gasket holding groove 21, thereby forming the undercut portions 23 and 23.

  Next, since the cavity 5 is defined between the inner surface of the upper mold 32 that exists so as to close the gasket holding groove 21 by the above-described mold clamping, and the gasket holding groove 21, As shown in FIG. 4, the gasket 4 is molded by filling a molding rubber material 40. When the molding rubber material 40 is cross-linked and cured, the mold is opened to obtain a base material integrated seal structure including the base material 2 and the gasket 4 integrated therewith as shown in FIG.

  The gasket 4 includes a held portion 41 that is a portion filled in the gasket holding groove 21 of the base material 2, and a seal that is a portion that is molded within the seal lip molding surface 32 a of the upper mold 32 and protrudes from the gasket holding groove 21. And a lip 42. The held portion 41 is formed by undercut portions 23 and 23 formed so that the raised portions 22 and 22 of the base material 2 are crushed by the upper die 32 and protrude into the groove in the mold clamping process shown in FIG. Since the gasket 4 is restrained by the gasket holding groove 21, the gasket 4 can be securely attached to the base material 2 even if it is made of a rubber material having no adhesion to the base material 2 or without applying an adhesive. Integrated into

  FIG.6 and FIG.7 is sectional drawing which shows the example of a shape change of the protruding part 22 formed in the base material 2 as another form of the manufacturing method of the base material integrated seal structure based on this invention. That is, in both the examples shown in FIGS. 6 and 7, the slope in which the height of the raised portion 22 decreases as the surface of the raised portion 22 facing the opposite side of the gasket holding groove 21 moves away from the gasket holding groove 21. 22a.

  In this way, when the gasket molding die 3 is clamped, the protruding portion 22 that is crushed by the upper die 32 is restricted from being plastically deformed to the opposite side of the gasket holding groove 21. Therefore, the gasket 22 is surely sealed. It is plastically deformed so as to protrude to the holding groove 21 side.

  FIG. 8 is a sectional view showing an example of a shape change of the upper mold 32 of the gasket molding die 3 as still another form of the method for producing a base material integrated seal structure according to the present invention, and FIG. In the form of 8, it is sectional drawing which shows the process of crushing the protruding part of a base material by mold clamping, and plastically deforming so that it may protrude from the inner surface of a gasket holding groove.

  That is, according to the form of FIG. 8, the upper mold 32 in the gasket molding die 3 is formed with the seal lip molding surface 32a on the surface facing the gasket holding groove 21 of the base material 2, and is located on both sides thereof. Thus, the surfaces of the base material 2 facing the raised portions 22 and 22 form gentle slopes 32c and 32c that recede from the gasket holding groove 21 toward the seal lip molding surface 32a. The base material 2 is shape | molded in the shape similar to the example shown by FIG.1 and FIG.2, ie, the protruding parts 22 and 22 are cross-sectional substantially U-shaped.

  In the above configuration, when the base material 2 is set in the gasket molding die 3 and the gasket molding die 3 is clamped as shown in FIG. 9, the seal lip molding in the upper mold 32 is performed in the process of clamping. The slopes 32c and 32c formed on both sides of the surface 32a are pressed against the raised portions 22 and 22 in the base material 2 and crushed. The inclined surfaces 32c and 32c are shaped so as to recede from the gasket holding groove 21 toward the seal lip molding surface 32a, so that the crushed raised portions 22 and 22 are plastically deformed so as to fall toward the seal lip molding surface 32a. In other words, since the direction of plastic deformation is directed to the gasket holding groove 21 side, the undercut portions 23 and 23 protruding from the inner side surfaces 21a and 21a of the gasket holding groove 21 can be reliably formed.

  FIG. 10 is a cross-sectional view showing an example of a shape change of the upper mold 32 of the gasket molding die 3 as still another form of the method for manufacturing a base material integrated seal structure according to the present invention.

  This form is also for directing the direction of plastic deformation due to the crushing of the raised portions 22, 22 toward the gasket holding groove 21, that is, both sides of the seal lip molding surface 32 a of the upper mold 32 in the gasket molding die 3. Step surfaces 32d and 32d that face each other across the seal lip molding surface 32a are formed at positions facing the outer end portions of the raised portions 22 and 22 of the base material 2. The base material 2 is shape | molded in the shape similar to the example shown by FIG.1 and FIG.2, ie, the protruding parts 22 and 22 are cross-sectional substantially U-shaped.

  Therefore, in the above configuration, when the base material 2 is set in the gasket molding die 3 and the gasket molding die 3 is clamped, the pressing on both sides of the seal lip molding surface 32a in the upper mold 32 is performed in the process of clamping. The surfaces 32b and 32b come into pressure contact with the raised portions 22 and 22 of the base material 2 and crush them. The bulged portions 22 and 22 to be crushed are restricted in plastic deformation to the side opposite to the gasket holding groove 21 by the step surfaces 32d and 32d, that is, the direction of plastic deformation is directed to the gasket holding groove 21 side. Also in this case, the undercut portions 23 and 23 (see FIG. 9) protruding from the inner side surfaces 21a and 21a of the gasket holding groove 21 can be reliably formed.

  In addition, although each form mentioned above demonstrated as what applied this invention to the sealing means of the division | segmentation part (mating surface) of outer shell cases, such as a mobile telephone, this invention is other electronic devices, precision instruments, It can also be applied to sealing means for electric power equipment and the like. For example, in the case of a fuel cell seal, a resin-based separator such as a conductive resin or a conductive filler-resin binder composite of the fuel cell corresponds to the substrate 2.

It is sectional drawing which shows the process of shape | molding a base material in preferable embodiment of the manufacturing method of the base material integrated seal structure based on this invention. FIG. 3 is a cross-sectional view showing a state in which a base material is set in a gasket molding die in a preferred embodiment of a method for producing a base material integrated seal structure according to the present invention. In a preferred embodiment of a method for producing a base material integrated seal structure according to the present invention, a cross section showing a step of crushing a raised portion of a base material by mold clamping and plastically deforming so as to protrude from the inner surface of a gasket holding groove FIG. It is sectional drawing which shows the process of shape | molding a gasket in preferable embodiment of the manufacturing method of the base-material integrated seal structure which concerns on this invention. It is sectional drawing which shows the base-material integrated seal structure manufactured by the process of FIGS. It is sectional drawing which shows the example of a shape change of the protruding part formed in a base material as another form of the manufacturing method of the base material integrated seal structure which concerns on this invention. It is sectional drawing which shows the example of a shape change of the protruding part formed in a base material as another form of the manufacturing method of the base material integrated seal structure which concerns on this invention. It is sectional drawing which shows the example of a shape change of the upper mold | type of a gasket shaping | molding metal mold | die as another form of the manufacturing method of the base material integrated seal structure which concerns on this invention. FIG. 9 is a cross-sectional view showing a step of crushing the raised portion of the base material by mold clamping and plastically deforming the protruding portion from the inner surface of the gasket holding groove in the form of FIG. 8. It is sectional drawing which shows the example of a shape change of the upper mold | type of a gasket shaping | molding metal mold | die as another form of the manufacturing method of the base material integrated seal structure which concerns on this invention. It is sectional drawing which shows the sealing structure of the outer shell case of the precision instrument by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material molding die 2 Base material 21 Gasket holding groove 21a Inner side surface 22 Raised portion 22a Slope 23 Undercut portion 3 Gasket molding die 32a Seal lip molding surface 32b Press surface 32c Slope 32d Step surface 4 Gasket 40 For molding Rubber material 41 Held part 42 Seal lip 5 Cavity

Claims (3)

Forming a base material having a gasket holding groove and a raised portion protruding from the groove shoulder to the groove outer side;
Crushing the raised portion and plastically deforming so as to protrude from the inner surface of the gasket holding groove;
Molding a gasket by filling a rubber material for molding into a cavity defined between an inner surface of a gasket molding die and the gasket holding groove;
The manufacturing method of the base-material-integrated seal structure characterized by consisting of.   2. The method for producing a base material integrated seal structure according to claim 1, wherein the bulging portion is crushed by a gasket molding die.   3. The base material integrated seal structure according to claim 2, wherein the gasket molding die is formed with a slope or a step surface for directing plastic deformation caused by crushing of the raised portion into the gasket holding groove. Method.

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