JP4191061B2 - Case member manufacturing method - Google Patents

Description

  The present invention relates to a resin case member constituting a casing for housing various electric and electronic devices, and more specifically, has an opening closed with a breathable porous film, and the casing is dustproof and waterproof. It is for imparting air permeability.

  An example of a housing that requires the above function is a connector case installed in an engine room of an automobile.

  In recent years, many electric and electronic control devices have been used in automobiles, and an engine control module (ECM), which is one of them, is desirably installed in the vicinity of the engine, and is inevitably provided in the vehicle body. However, in this case, the temperature inside the engine room is increased to 100 ° C. or higher, especially when the engine is driven. If the electric control device is arranged, the operation reliability and durability of the electric control device may be impaired due to the high temperature and humidity.

  Therefore, it can be considered that the engine room is not easily affected by the high temperature, for example, a space called a cowl box below the front window. Because it was easy for water to enter, the case had to be sealed. However, if the case is completely sealed, the heat generated when the internal electric control device is operated will not escape, and the atmospheric pressure in the case may increase due to thermal expansion, and the sealed part may be partially destroyed. there were. Furthermore, due to the influence of this heat, there is a risk of causing malfunctions in internal devices such as computers or causing performance degradation.

  Therefore, in order to solve this point, a part of the member constituting the case is provided with a vent hole, and gas such as air can be transmitted so as to close the vent hole, but the passage of water droplets and dust is prevented. An attachment with a breathable porous membrane to prevent it has been developed.

  Conventionally, as a case member using this kind of air permeable porous membrane, as shown in FIG. 8, a case member main body in which a first vent hole 20a having a predetermined inner diameter dimension that communicates the case in and out is formed. 20 and has a property of allowing gas permeation and blocking liquid and solid permeation, and covering the first air passage 20a from the outside thereof at the outer peripheral portion of the first air hole 20a. A ventilation sheet 23 that is integrally joined, and is arranged outside the ventilation sheet 23 so as to cover the ventilation sheet 23 from the outside, and its peripheral edge is hermetically joined to the case member 20. And a cover member 21 provided with a second ventilation hole 21a communicating with the first ventilation hole 20a.

In this case member 20, after the ventilation sheet 23 is set in the housing recess 21b of the cover member 21, the cover member 21 is integrally formed with the case member main body 20 by insert molding. (For example, refer to Patent Document 1).
JP 2003-152347 A (page 5-13, FIGS. 2 and 5)

  Since the conventional case member described above is manufactured by insert molding after preparing a cover member for holding or fixing the air-permeable sheet and setting the air-permeable sheet on the cover member, the cover member is attached to the case. There was a problem that it had to be molded separately from the member, the number of processes was large, and the productivity was poor.

  Moreover, since two molds for manufacturing are required for molding the cover member and for molding the case member main body, the equipment costs increase, and the unit price of the manufactured case member itself also increases. was there.

  An object of the present invention is to solve these problems.

According to a first aspect of the present invention, there is provided a method of manufacturing a resin case member having an opening closed by a breathable porous membrane and constituting a housing for storing various electric / electronic devices. And an annular slide mold that is fitted into the cavity block and has an annular convex portion that is slidable along the axial direction, and is provided opposite to the cavity block and the slide mold. The cavity block film receiving surface and the slide mold film receiving surface are arranged on the same plane using a mold device having a core block that is made of a porous material. After the membrane is received, the outer peripheral end surface of the air-permeable porous membrane is brought into contact with the inner peripheral surface of the convex portion of the slide mold, and then the core block is brought close to the cavity block and the slide mold. , Core block The mold is clamped between the cavity block and the core block in a state in which the air-permeable porous membrane is in contact with the opening forming protrusion, thereby forming a cavity space on the outer peripheral side of the core block. After filling the cavity space with the molten resin, the slide mold is slid along the axial direction so that the convex portion is immersed in the cavity block to form an immersion space. The molten resin is filled and the periphery of the breathable porous membrane is buried in the resin so that the breathable porous membrane and the molten resin are integrated. In the invention according to claim 2, when a groove is formed in the cavity block corresponding surface of the protrusion of the core block, and the molten resin is filled into the cavity space, the groove is filled with the molten resin, A spoke-shaped reinforcing rib continuous to the inner end of the opening is provided on the surface of the breathable porous membrane.

In the case member and the manufacturing method thereof according to the present invention, a double annular ridge or an annular concave groove is formed around one of the openings as the annular convex slide mold moves, and a breathable porous material is formed at this location. Since the end edge of the membrane is sandwiched in the resin, a breathable porous membrane having flexibility can be directly incorporated into the case member by insert molding and manufactured. Therefore, the productivity is improved, and only one mold for manufacturing is required, and the capital investment cost is reduced. As a result, this type of case member can be provided at low cost. . In addition, since the spoke-shaped reinforcing ribs that are continuous to the inner end of the opening are provided on the surface of the breathable porous membrane, the surface of the breathable porous membrane is protected by the reinforcing ribs. Inadvertent damage accidents are prevented, and the predetermined function can be exhibited for many years.

  Hereinafter, the present invention will be described in detail based on illustrated embodiments.

  FIG. 1 is a simplified perspective view showing an embodiment of the case member of the present invention. The case member 1 is formed of a thermosetting resin having a heat resistance or a hard thermoplastic resin, and is integrally joined to a case main body (not shown) so that an engine control module (ECM) It constitutes a sealed container-like housing for storing such electrical / electronic devices. And the opening 2 block | closed with the air permeable porous membrane 3 which this invention makes the principal part is provided in the predetermined position of the surface.

  This breathable porous membrane 3 is formed by a polytetrafluoroethylene resin (PTFE, tetrafluoroethylene resin) drawn into a sponge shape having fine pores of 0.05 μm to 20 μm inside. Water and water droplets with a size of 0.0004 μm in the atmosphere, water vapor, and smaller atmospheric gases (nitrogen gas, oxygen gas) are allowed to pass through, but the size is 100 μm (approximately drizzle size) or more. It has a function to block the passage of liquid and dust. Specifically, US W. L. The product name “Gore-Tex” from Gore and the product name “Micro-Tex” from Nitto Denko Corporation can be suitably used.

  The case body to which the case member 1 is integrally joined is not limited to resin, and may be a metal plate press-molded product or a light alloy die-cast molded product.

  FIG. 2 is an enlarged plan view of a portion where the opening 2 is provided, and FIG. 3 is an enlarged view of the back side thereof. As shown in the figure, a spoke-like reinforcing rib 4 continuous to the inner end of the opening 2 is provided on the surface side of the breathable porous membrane 3, and a double annular protrusion is provided around the opening 2 on the back surface side. The strip 5 is integrally formed with the case member.

  4 to 6 are explanatory views showing the molding process of the case member 1. Here, regarding the illustration of the air-permeable porous membrane 3, since it cannot be shown in the original size display, the thickness thereof is considerably enlarged.

  The mold for molding a case member of the present invention is composed of a pair of a fixed side and a movable side in the same manner as a normal injection mold, and a fixed side cavity block for molding the surface side of the case member 1 11, an annular slide mold 12 having a convex cross section at the tip is provided in such a manner that the tip protrudes and appears in the cavity space. Here, the inner diameter between the convex portions 12a of the slide mold 12 is set to a dimension substantially equal to the outer diameter of the air-permeable porous membrane 3 embedded in the opening 2 of the case member 1, The height is set to a dimension approximately equal to the thickness of the breathable porous membrane 3.

  The movable core block 10 facing the cavity block 11 is integrally formed with an opening forming protrusion 10a at a position corresponding to the inside of the slide mold 12. A groove 10b for forming a reinforcing rib is provided in a substantially Y shape on the front surface (lower side in the figure) of the opening forming protrusion 10a.

Next, the molding procedure of the case member 1 of the present invention using this mold will be described. First, as shown in FIG. 4, with the mold open, the membrane receiving surface of the cavity block 11 and the slide mold 12 The membrane receiving surfaces are arranged on the same plane, and the air-permeable porous membrane 3 is received by these membrane receiving surfaces. Thereafter, as shown by an arrow, the breathable porous membrane 2 is brought into contact with the inner peripheral surface of the convex portion 12a in the convex portion 12a of the slide mold 12 provided on the cavity block 11 side. Store and set as shown. Next, as shown in FIG. 6, the core block 10 is brought close to the cavity block 11 and clamped, and the case member is molded from the injection device (not shown) into the cavity space 13 formed between the blocks 10 and 11. The molten resin R for use is filled. At this time, because of the sponge-like structure, the outer peripheral end surface 3a of the flexible breathable porous membrane 3 is protected by the convex portion 12a of the slide mold 12, and the peripheral portion and the reinforcing rib 4 are formed on the upper surface. Since it is pressed and held by the opening forming protrusion 10a of the core block 10 except for the places, the high-pressure molten resin R is not displaced even if it is press-fitted into the cavity. Therefore, the molten resin R filled in the cavity is in contact with the upper peripheral edge of the breathable porous membrane 3 at a location facing the groove 10b. Here, since the air-permeable porous membrane 3 has a large number of fine pores on its surface as described above, the molten resin R enters the pores (not shown) and anchors (throwing). It will be joined integrally by the effect.

  Next, as shown in FIG. 6, when the slide mold 12 is moved so that the tip thereof is immersed in the cavity block 11, the uncured molten resin R enters the immersion space, and the air-permeable porous It goes around the peripheral end surface and the lower peripheral edge of the membrane 3, and the periphery of the air-permeable porous membrane 3 is buried in the resin so as to be integrated. At this time, the peripheral edge of the air-permeable porous membrane 3 is held on the upper side by the anchor effect that the resin enters inside as described above, and therefore does not hinder the wraparound of the resin.

  Then, the molten resin R is filled in the cavity 13 in this way, the mold is opened after cooling, and the molded case member 1 is taken out from the mold by a known appropriate means.

  As described above, the case member 1 of the present invention can be manufactured by attaching the flexible breathable porous membrane 3 directly so as to close the opening 2 by insert molding. Therefore, the case member 1 has a characteristic double annular protrusion 5 formed by moving the annular convex slide mold 12 in the manufacturing process. ).

  FIG. 7 shows a manufacturing process of the case member 1A according to another embodiment. In this case, the slide mold 12 and the opening forming portion 11a on the cavity block 11 side located inside the slide mold 12 are preliminarily placed around the periphery. In this manner, the air-permeable porous membrane 3 can be disposed near the center of the opening 2 of the case member 1 in the thickness direction, and around the opening associated with the lowering of the slide mold 12. The protrusion (double annular ridge 5) can be eliminated. In this case, an annular groove 6 formed by the convex portion 12a of the slide mold 12 is characteristically formed around the back surface of the opening 2 instead.

  As described above, the case member 1 of the present invention is manufactured by one molding with one mold.

  In the illustrated embodiment, the reinforcing rib 4 that protects the surface of the breathable porous membrane 3 is exemplified as having a substantially Y shape, but the reinforcing rib 4 is continuous with the inner end of the opening 2. As long as it is integrally molded with the case member 1, the shape is arbitrary. Further, when the opening 2 is small or there is no possibility of foreign matter entering the opening 2, the reinforcing rib 4 is not necessarily provided.

  Moreover, although the circular thing was illustrated as the air permeable porous membrane 3, this air permeable porous membrane 3 should just be attached so that the opening 2 provided in the case member 1 may be plugged up, and the shape Is optional.

  Further, although not shown in the figure, the opening forming projection 10a and the opening forming portion 11a in contact with the breathable porous membrane 3 are provided with protruding edges around the surface thereof, and the breathable porous membrane is provided. 3 is pressed all over so that the pores are not crushed.

It is the schematic which showed embodiment of the case member which concerns on this invention. It is a principal part enlarged plan view of the case member shown in FIG. It is a principal part expanded back view of the case member shown in FIG. It is sectional drawing of the state in which the shaping | molding die at the time of shaping | molding opened. It is sectional drawing of the shaping | molding initial stage after mold clamping. It is sectional drawing of a shaping | molding completion state same as the above. It is explanatory drawing which showed the formation process of the case member by other embodiment. It is principal part sectional drawing of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A Case member 2 Opening 3 Breathable porous membrane 4 Reinforcing member 5 Double annular protrusion 6 Annular groove 10 Mold core block 11 Mold cavity block 12 Slide mold 12a Protrusion 13 Cavity )

Claims (2)

In the method of manufacturing a resin case member having an opening closed by a breathable porous membrane and constituting a housing for storing various electric and electronic devices,
  A cavity block, an annular projection mold that fits in the cavity block and has an annular convex portion and is slidable along the axial direction, and is opposed to the cavity block and the slide mold. Using a mold device provided with a core block provided
  The film receiving surface of the cavity block and the film receiving surface of the slide mold are arranged on the same plane, and the convex portion of the slide mold is received with the air-permeable porous film received by these film receiving surfaces. After contacting the outer peripheral end surface of the breathable porous membrane to the inner peripheral surface,
  The core block is placed close to the cavity block and the slide mold, and the cavity block and the core block are clamped in a state where the core block is brought into contact with the air permeable porous membrane at the opening forming protrusion of the core block. And
  Thereby, a cavity space is formed on the outer peripheral side of the core block, and then, after filling the cavity space with a molten resin,
  The slide mold is slid along the axial direction so that the convex portion is immersed in the cavity block to form an immersion space, and the immersion space is filled with molten resin from the cavity space,
  A method for producing a case member, wherein the breathable porous membrane and the molten resin are integrated by burying the periphery of the breathable porous membrane in a resin. When a groove is formed in the cavity block corresponding surface of the protrusion of the core block and the cavity space is filled with the molten resin, the groove is also filled with the molten resin, and an opening is formed on the surface of the breathable porous membrane. The method for manufacturing a case member according to claim 1, wherein a spoke-shaped reinforcing rib is provided at an inner end of the casing.

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