JP6628483B2 - Molding method for molded products - Google Patents

Description

  The present invention relates to a method for molding a molded article suitable for molding a molded article having a curved surface or an inclined surface on the surface.

  2. Description of the Related Art Conventionally, some molded products have a base curved in an arc shape, such as a base plate (1-2) used for a slide-type electronic component (100) shown in FIGS. There is a base (60) having a structure in which a flexible circuit board (40) is insert-molded. The surface of the flexible circuit board (40) is exposed on the surface of the base (60), and the slider (150) that slides on the base in the form of an arc moves over the sliding contact pattern (43) of the flexible circuit board (40). , 45), the output of which changes by sliding on it. This type of sliding electronic component (100) is mounted, for example, on the outer peripheral surface of a zoom (focus) cylinder of a zoom camera.

  FIG. 9 is an explanatory diagram of a molding method for molding a molded product such as the base-attached substrate (1-2). In order to mold the molded product, a molten resin is put into a cavity having a circular cross section formed by a first mold 501 shown by a solid line in the figure and a second mold 503 shown by a dotted line in the figure. The molded product 505 is formed by filling and solidifying, and then the second mold 503 is removed. Next, a plurality of protrusion pins 507 are protruded from the inside of the first mold 501, whereby the molded product 505 is extruded from the first mold 501 and taken out. The tip surface of each protrusion pin 507 has a shape (a part of an arc surface) that matches the surface shape of the molded product 505. In FIG. 9, what is indicated by a dotted line in the molded product 505 (on the upper surface side) is the flexible circuit board 509 insert-molded in the molded product 505. In FIG. 9, a plurality of protrusions projecting from the first mold 501 into the cavity are positioning pins 511 of the flexible circuit board 509.

JP 2011-135005 A

However, the above-mentioned molding method has the following problems.
That is, in FIG. 9, when the molded product 505 is taken out from the first die 501 by the protruding pin 507, the protruding pin 507 near the center presses the molded product 505 substantially perpendicularly to the surface of the molded product 505, so that the molding is performed smoothly. The product 505 can be protruded. However, in the case of the protruding pins 507 at both ends, the surface of the molded product 505 is oriented in a direction substantially parallel to the protruding direction of the protruding pin 507. When the molded product 505 is bent inward, the molded product 505 cannot be pushed out smoothly in the protruding direction of the push-out pin 507, and the removed molded product 505 may be deformed. was there. This problem becomes more serious as the length of the arc surface of the molded product 505 becomes longer and the direction in which the protrusion pins 507 protrude and the surface of the molded product 505 become closer to parallel. The above problem may occur not only when the molded product 505 has a curved surface with respect to the protrusion pin 507 but also when the molded product 505 has an inclined surface.

  The present invention has been made in view of the above-described points, and its object is to provide a molded product having a curved surface or an inclined surface with respect to a projecting direction of a projecting pin projecting from a mold at the time of molding. It is another object of the present invention to provide a method for molding a molded product that can smoothly extrude the molded product from a mold.

According to the present invention , a flexible circuit board is inserted into a cavity , then the cavity is filled with a melt-molded resin and solidified , and then a molded product obtained by insert-molding the flexible circuit board is inserted into the mold. A method of molding a molded product to be taken out by a protruding pin protruding from a cavity, wherein a surface of the cavity from which the protruding pin protrudes is a curved surface or an inclined surface, and the flexible circuit board is melt-molded during the insert molding. The resin filling pressure makes close contact with the curved surface or the inclined surface in the cavity, and at this time, a rail portion serving as a moving body sliding surface is formed on both sides of the flexible circuit board by the molten molding resin. when solidified the molten molding resin into the cavity, the tip of the ejector pin, the portion serving as the rail portion The surface, the molten molding resin from the surface of the portion to be the the rail portion is upwardly and wherein the keep by bite does not project.
In order to make the tip of the protruding pin bite into the surface of the molded product, the tip of the protruding pin may be provided with, for example, a protruding portion protruding into the cavity, or a plurality of irregularities protruding into the cavity may be provided. . Also, the surface may have various shapes other than those described above.
Thus, when the protruding pin is protruded from the curved surface or the inclined surface of the cavity and the molded product is taken out, the tip of the protruding pin does not slip off the surface of the molded product. Thus, the molded product can be smoothly removed from the mold.

Further, the present invention is characterized in that a molded product obtained by insert-molding the flexible circuit board is manufactured by inserting a flexible circuit board into a cavity before filling the molten molding resin.
For example, in a case where the flexible circuit board is exposed on one surface of a molded product, and when the exposed surface is pressed by a protruding pin, molding of a portion other than the exposed flexible circuit board (for example, the periphery thereof) is performed. Preferably, the surface of the article is pressed.

Further, according to the present invention, the surface of the cavity from which the protrusion pins protrude is a concave curved surface, and the protrusion pins are plural, and when the cavity is filled with a melt-molded resin and solidified, Of the plurality of protruding pins, the protruding pin near the center of the curved surface does not bite into the molded product, while the protruding pins near both ends of the curved surface bite into the molded product.
As a result, slippage of the protruding pin at a slippery position can be mainly prevented. In other words, since the protrusion pin which is not slippery is not cut into the molded product, the shape change of the surface of the formed product due to the bit of the protrusion pin can be minimized.

  According to the present invention, it is possible to smoothly remove the molded product from the mold even when the molded product has a curved surface or an inclined surface with respect to the projecting direction of the protruding pin that protrudes from the mold during molding. Will be possible.

FIG. 3 is an explanatory diagram of a molding method of a molded product 1-1. FIG. 3 is an explanatory diagram of a molding method of a molded product 1-1. FIG. 3 is an explanatory diagram of a molding method of a molded product 1-1. FIG. 3 is an explanatory diagram of a molding method of a molded product 1-1. FIG. 2 is a perspective view showing an electronic component 100 configured using a molded product 1-2. FIG. 2 is an exploded perspective view of the electronic component 100. FIG. 6 is an enlarged perspective view of a portion A shown in FIG. 5. FIG. 6 is an enlarged perspective view of a portion B shown in FIG. 5. It is explanatory drawing of the molding method of the conventional molded article.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 4 are explanatory views of a molding method of a molded product 1-1 according to an embodiment of the present invention. FIGS. 1, 3, and 4 are schematic sectional views, and FIG. 2 is a diagram showing a cavity C shown in FIG. FIG. 4 is a schematic plan view showing an outline of an arrangement relationship of a flexible circuit board 40 and the like when viewed from above. The molded product 1-1 is formed by insert-molding a flexible circuit board 40 on the upper surface (convex side surface) of a base 60 which is formed in a band shape and curved in an arc shape, as shown in a cross section in FIG. I have. In the following description, “up” means a direction from the second mold 30 shown in FIG. 1 to the first mold 10 side, and “down” means an opposite direction.

  In order to mold the molded product 1-1 shown in FIG. 4, first, as shown in FIG. 1, a first mold 10, a second mold 30, and a flexible circuit board 40 indicated by a dotted line are prepared. As shown in FIG. 2, the flexible circuit board 40 has a pair of linear members in which a slider slides on one surface of a flexible synthetic resin film 41 made of, for example, a PET (polyethylene terephthalate) resin. The sliding contact patterns 43 and 45 (the resistor pattern 43 and the conductor pattern 45) are formed in parallel (parallel). Note that the flexible circuit board 40 shown in FIG. 2 shows a state in which the flexible circuit board 40 shown by a dotted line in FIG. However, when no external force is applied, it is in a state of extending in the longitudinal direction in a flat shape without curvature. Two sets of left and right semicircular concave guides 51 (four in total) are provided on both left and right sides (both sides along the linear direction of the sliding contact patterns 43 and 45) 49 near the center of the flexible circuit board 40. Is provided.

  As shown in FIG. 1, the first mold 10 is provided with a concave portion 11 having a substantially semicircular concave shape on the surface facing the flexible circuit board 40, and the center of a bottom surface (curved surface) 12 of the concave portion 11 having an arc shape. Four sets of guide projections 15 are protruded from the vicinity and the vicinity of both ends in a downward direction, each pair being left and right. As shown in FIG. 2, two sets (four) of the guide protrusions 15 near the center are provided at positions to be inserted into the respective guide portions 51 of the flexible circuit board 40. On the other hand, two sets (four) of the guide protrusions 15 near both ends are provided at positions in contact with the left and right sides 49 of the flexible circuit board 40 as shown in FIG.

  Also, the first mold 10 has seven sets of protruding pins, one pair each on the left and right sides, at three places near the center of the arc-shaped bottom surface 12 of the recess 11, on both sides thereof, and further on both sides thereof. 17a, 17b and 17c are built in. As shown in FIG. 2, the protruding pins 17 a, 17 b, and 17 c are located at positions outside the width direction outside the position facing the surface of the flexible circuit board 40 (positions at which the surface of the flexible circuit board 40 does not directly contact). ). In addition, each protruding pin 17a, 17b, 17c is installed in parallel, and all descend downward. That is, it reciprocates between the position shown in FIG. 1 (the position at the time of molding) and the position shown in FIG. 4 (the position at the time of extrusion) projecting below the position shown in FIG.

  The tip surfaces of the three sets of protruding pins 17a near the center are smooth and have an arc surface that is continuous with the surrounding bottom surface 12 at the molding position (there is no irregularity in this arc surface). The distal end surfaces of the two sets of the protruding pins 17b on both sides of the protruding pin 17a are arc-shaped surfaces that are continuous with the surrounding bottom surface 12 at the molding position and have an uneven surface 171 having a plurality of irregularities. The shape of the unevenness is triangular in this example. The convex portion of the uneven surface 171 protrudes below the surrounding bottom surface 12, and the concave bottom portion is located on the same plane as the surrounding bottom surface 12 (or at a position protruding therefrom). The tip surfaces of the two sets of protruding pins 17c on both sides of the both protruding pins 17b are partly arcuate surfaces that are continuous with the surrounding bottom surface 12 at the molding position, and the other part is from the bottom surface 12 The projection 18 protrudes downward in the cavity C. The tip of the protruding portion 18 protrudes in the moving direction of the protruding pin 17c.

  As shown in FIG. 1, the second mold 30 is provided with a convex portion 31 having a substantially semicircular convex shape (a convex shape obtained by vertically dividing a column having a low height) on a surface facing the flexible circuit board 40. ing. The width of the convex portion 31 is slightly larger than the width of the flexible circuit board 40 and is substantially the same as the width of the concave portion 11 of the first mold 10 as can be seen from the cavity C shown by a dotted line in FIG. Is formed. A resin injection port (gate) G is provided at the center (the center in both the width direction and the longitudinal direction) of the arc-shaped upper surface of the convex portion 31. The resin injection port G is formed in a shape in which the melt-molded resin blows out right above. Further, on the upper surface of the projection 31, four sets (eight places) of guide projection insertion holes 33 for inserting the tips of the four sets of guide projections 15 of the first mold 10 are provided.

  In order to form the molded product 1-1, first, as shown by a dotted line in FIG. 1, the flexible circuit board 40 is set on the bottom surface 12 of the concave portion 11 of the first mold 10 while bending. At this time, the two sets of guide projections 15 at the center of the first mold 10 are respectively engaged with the respective guide parts 51 of the flexible circuit board 40, and at the same time, one set of guide parts 15 on both ends are connected to the left and right sides of the flexible circuit board 40. The flexible circuit board 40 is positioned in the recess 11 by abutting the side 49.

  Next, as shown in FIG. 1, a second mold 30 is brought into contact with the lower surface of the first mold 10, thereby forming an arc-shaped cavity C between the concave portion 11 and the convex portion 31. At this time, the tip of each guide projection 15 of the first mold 10 is inserted into each guide projection insertion hole 33 of the second mold 30. At this time, as described above, the protruding portion of the uneven surface 171 at the tip end surface of the protruding pin 17b and the protruding portion 18 of the protruding pin 17c protrude into the cavity C as described above.

  Next, if the melt-molded resin is press-fitted into the cavity C from the resin injection port G of the second mold 30, the flexible circuit board 40 in the cavity C has the upper surface formed by the pressure at the time of press-fitting. 12 and at the same time, the cavity C on the lower surface side of the flexible circuit board 40 is filled with the molten molding resin. Then, the melt-molded resin is cured. At this time, the tips of the protruding pins 17b and 17c that have protruded into the cavity C bit into the surface of the cured molded product 1-1.

  Next, as shown in FIG. 3, the second mold 30 is removed from the first mold 10. At this time, the molded product 1-1 is stuck to the bottom surface 12 of the first mold 10.

  Then, if all of the protruding pins 17a, 17b, and 17c shown in FIG. 3 are protruded by the same dimension in a direction directly below, the molded product 1-1 is pushed downward as shown in FIG. It is taken out from the concave portion 11 of the mold 10.

  At the time of pushing out the molded product 1-1 by the respective protruding pins 17a, 17b, 17c, since the surface of the molded product 1-1 is substantially perpendicular to the pushing direction of the three sets of protruding pins 17a at the center, the respective protruding pins 17a are provided. Even if the tip surface of 17a is a smooth surface, the molded product 1-1 can be pushed out smoothly without slipping on the surface of the molded product 1-1.

  On the other hand, since the surface of the molded product 1-1 is inclined by about 45 ° with respect to the extrusion direction, the tip of the projection pin 17b located on each side of the extrusion pin 17a is There is a risk of slipping on the surface of the molded product 1-1. However, an uneven surface 171 is provided on the tip surface of each protruding pin 17b, and the uneven surface 171 cuts into the surface of the molded product 1-1. In other words, it is formed on the surface of the molded product 1-1. Since the uneven surface 171 of the protruding pin 17b is locked to the unevenness 61 described below, when the protruding pin 17b is pushed out, it does not slip on the surface of the molded product 1-1. -1 can be smoothly pushed out in the pushing direction of the protruding pin 17b.

  Furthermore, since one set of the protruding pins 17c located on both sides of the protruding pin 17b has the surface of the molded product 1-1 substantially parallel (about 10 ° or less) to the extrusion direction, the protruding pin 17c is When extruded, the tip is very slippery with respect to the surface of the molded product 1-1. However, a protrusion 18 is provided on the tip end surface of each protruding pin 17c, and the protrusion 18 cuts into the surface of the molded product 1-1. In other words, the protrusion 18 is formed on the surface of the molded product 1-1. Since the tip of the protrusion 18 is locked to the step 63 described below, when the push-out pin 17c is pushed out, it does not slip on the surface of the molded product 1-1. 1 can be smoothly pushed out in the pushing direction of the protruding pin 17c. The removal of the second mold 30 from the first mold 10 and the pushing of the protruding pins 17a, 17b, 17c may be performed simultaneously or continuously.

  As described above, the molded product 1-1 shown in FIG. 4 is completed. This molded product 1-1 has a base 60 formed of a molded product having a cavity C shape, that is, a band-like semi-circular arc shape, and has a flexible circuit board 40 (with its sliding contact pattern 43, 45) is exposed. A pair of projections and depressions 61 formed by the protrusion pins 17b and a pair of protrusions and depressions 17c are formed on both outer sides of the flexible circuit board 40 on the convex side surface of the base 60 in the width direction (the direction other than the longitudinal direction). A pair of the formed step portions 63 is formed. A through hole 65 is formed by each guide projection 15 shown in FIG.

  FIG. 5 is a perspective view showing an electronic component (sliding type electronic component) 100 configured using the molded product 1-2 actually manufactured by the molding method, FIG. 6 is an exploded perspective view of the electronic component 100, and FIG. FIG. 8 is an enlarged perspective view of part A shown in FIG. 6, and FIG. 8 is an enlarged perspective view of part B shown in FIG. The electronic component 100 is a sliding electronic component mounted on the outer peripheral surface of a zoom (focus) cylinder of the zoom camera to detect the zoom position and the focus position of the zoom camera. And a moving body 130 to which a moving element 150 is attached. In the molded product 1-2 shown in these figures, the same or corresponding parts as those of the molded product 1-1 are denoted by the same reference numerals. Note that items other than those described below are the same as those in the above-described embodiment.

  In the flexible circuit board 40, a strip-shaped lead-out portion 57 is connected to one side near the one end of the flexible circuit board 40 at a right angle, and is connected to the pair of sliding contact patterns 43 and 45. The circuit pattern (not shown) is formed.

  The base 60 has a rail portion 67 that is curved in an arc on both sides along the longitudinal direction. The base 60 has both sides (rail portions 67) formed up to the upper side of the upper surface of the flexible circuit board 40, whereby the upper and lower surfaces of both sides (49 in FIG. 2) of the flexible circuit board 40 are The flexible circuit board 40 is more securely fixed to the base 60. At the left and right outer positions of the flexible circuit board 40 where the upper surface of the convex side of the base 60 is exposed, two sets of unevenness 61 and a stepped portion 63 are respectively provided (only one set on the near side is shown in the figure). ) Is formed. The through holes 65 are also formed at predetermined positions on both left and right outer sides of the flexible circuit board 40. FIG. 7 is an enlarged perspective view of a main part showing a portion of unevenness 61 and FIG. In both figures, the unevenness 61 has a plurality of uneven shapes, and the step portion 63 has a shape in which the depth is increased downward and a flat pin contact portion 63a is provided on the lower side. Neither the unevenness 61 nor the step 63 is recessed from the rail 67 (that is, the sliding surface of the moving body 130), which is a curved surface curved in an arc shape, and does not protrude upward from the upper surface of the rail 67. , So that the movement of the moving body 130 described below is not hindered.

  On the other hand, the moving body 130 is formed by molding a synthetic resin into a substantially rectangular shape, and a rail engaging portion 131 is formed in the vicinity of four corners on the lower surface. The rail engaging portion 131 is bent in a substantially L-shape, and has such a dimension as to be movably engaged with the rail portion 67. On the other hand, the slider 150 has a base 151 formed by forming an elastic metal plate into a substantially rectangular shape, and a pair of arms 153 (only one is shown in the figure) protruding from one side of the base 151. The contact portion 155 is formed by folding the base portion of the 153 by 180 ° and bending the contact portion 155 downward in the vicinity of the tip. The base 151 is provided with a moving body mounting portion 157 composed of a pair of small holes for mounting on the lower surface of the moving body 130. Then, the base 151 of the slider 150 is brought into contact with the lower surface of the moving body 130, and a small projection (not shown) provided on the lower surface of the moving body 130 is inserted into the moving body mounting portion 157 of the slider 150, and a tip of the small projection is formed. Is heated, and thereby the slider 150 is attached to the lower surface of the moving body 130. The moving body 130 to which the slider 150 is attached is called an electrical functional component.

  Then, when the rail engaging portion 131 of the moving body 130 to which the slider 150 is attached is inserted from one end of the rail portion 67 of the base 60, the electronic component 100 shown in FIG. 5 is completed. When the moving body 130 is slid in the arc direction on the molded product 1-2, the two contact portions 155 of the slider 150 slide on the sliding contact patterns 43 and 45, respectively, and the output is output on the drawing portion 57. Circuit pattern.

  As described above, when the surface (bottom surface 12) of the cavity C from which the protrusion pins 17b and 17c protrude is a curved surface, when the cavity C is filled with the molten molding resin and solidified, The protruding pins 17b and 17c are provided with an uneven surface 171 and a protruding portion 18 at the tips thereof so as to bite into the surfaces of the molded products 1-1 and 1-2. , 17c to remove the molded products 1-1, 1-2 after molding, the tips of the protruding pins 17b, 17c do not slip from the surfaces of the molded products 1-1, 1-2. Thereby, the molded products 1-1 and 1-2 can be smoothly removed from the molds 10 and 30.

  Further, according to the method of forming the molded products 1-1 and 1-2, of the plurality of projecting pins 17a, 17b and 17c, the projecting pin 17a near the center of the curved surface (the bottom surface 12) is formed into the molded product 1-1. , 1-2, while the protrusion pins 17b, 17c near both ends of the curved surface are made to bite into the molded products 1-1, 1-2, so that the protrusion pins 17b, 17c in the slippery position are formed. Slip can be mainly prevented. In other words, since the protruding pins 17a that are not slippery are not cut into the molded products 1-1 and 1-2, it is possible to minimize the shape change of the surfaces of the molded products 1-1 and 1-2 due to the biting of the protruding pins 17a. It becomes possible.

  In the above embodiment, the uneven surface 171 is used as the shape of the tip of the protruding pin 17b, and the unevenness 61 is formed on the molded products 1-1 and 1-2. Thus, only the concave portions without the convex portions (that is, the concave shape similar to the step portion 63) may be formed in the molded products 1-1 and 1-2. In the case of such a configuration, it is not necessary to process the tip end surface of the protruding pin 17b into an uneven shape, and the die manufacturing process can be reduced.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications may be made within the scope of the claims and the technical idea described in the specification and the drawings. It is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and effects of the present invention are exhibited. For example, in the above-described embodiment, an example in which the present invention is applied to the case where the protruding pin protrudes from the curved surface of the cavity has been described. Can be applied. The term “inclined surface” as used herein means that the surface inside the cavity from which the ejector pin projects is inclined with respect to the projecting direction of the ejector pin. Further, in the above embodiment, an arc surface is shown as the curved surface in the cavity, but various curved surfaces other than the arc surface may be used. The curved surface is not limited to a concave curved surface, but may be a convex curved surface.

  Further, in the above embodiment, the shape of the tip of the protruding pin is formed as an uneven surface or provided with a protruding portion, but the present invention is not limited to these. Various modifications are possible, such as projecting a plurality of the projections. In short, any configuration may be used as long as the tip of the protruding pin bites into the surface of the molded product when the cavity is filled with the molten resin and solidified.

1-1 Molded product 10 1st die (die)
C cavity 12 Bottom (curved surface)
15 Guide projection 17 (17a, 17b, 17c) Projection pin 171 Irregular surface 18 Projection 30 Second die (die)
40 Flexible circuit board 60 Base 1-2 Molded product 100 Sliding electronic component (electronic component)
130 Moving object (electrical functional parts)
150 Slider (electrical functional parts)

Claims (2)

A protruding pin that inserts a flexible circuit board into the cavity , then fills the cavity with a melt-molded resin and solidifies , and then protrudes a molded product obtained by insert-molding the flexible circuit board from the mold. A molding method of a molded article taken out by
The surface of the cavity from which the protrusion pins protrude is a curved surface or an inclined surface, and the flexible circuit board is provided with the curved surface or the inclined surface in the cavity by the filling pressure of the molten molding resin during the insert molding. In this case, a rail portion serving as a sliding surface of the moving body is formed on both sides of the flexible circuit board by the molten molding resin,
On the other hand, when the cavity is filled with the molten molding resin and solidified, the tip of the protruding pin is formed on the surface of the portion to be the rail portion by the molten molding resin more than the surface of the portion to be the rail portion. A method of molding a molded product, wherein the molded product is made to bite so as not to protrude upward . It is a molding method of the molded article according to claim 1 ,
The surface of the cavity from which the protrusion pins protrude is a concave curved surface, and the number of the protrusion pins is plural,
When the melt-molded resin is filled into the cavity and solidified, of the plurality of protrusion pins, the protrusion pin near the center of the curved surface does not bite into the rail portion , while one of the plurality of protrusion pins is near both ends of the curved surface. Characterized in that the protruding pin of (1) is cut into the rail portion .

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