JP3574052B2 - Method of manufacturing member for push button switch - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a member for a push button switch used as an input device of a mobile phone, a car phone, a remote controller, an OA device, a computer, a game device, and the like.
[0002]
[Prior art]
The push button switch includes a base material made of a polymer compound, and a member for a push button switch having a substantially hat-shaped cross section adhered to the surface of the base material. It is widely used as a device. A member for a push button switch is manufactured as a key top by printing a pattern consisting of characters and symbols on the surface of a flexible film, and thereafter drawing the flexible film in a concave shape and a convex shape. It is fitted on the surface of the substrate via an adhesive.
[0003]
[Problems to be solved by the invention]
A conventional push button switch member is manufactured by printing a pattern on the surface of a flexible film as described above, and then simply drawing the flexible film into a concave shape and a convex shape. Therefore, it is extremely difficult to precisely form the shape on the tip end surface of the push button switch member, and the minimum radius of the corner is about R = 0.5 mm. Furthermore, when the concave and convex molds are clamped, the flexible film is stretched, deformed, and expanded by pressure, so that it is very difficult to form and determine a small pattern, and to design and design a member for a push button switch. There is a problem that a great restriction occurs in the product shape.
[0004]
The present invention has been made in view of the above, and it is possible to form a shape relatively precisely on a protruding tip surface or the like of a product, a radius of a corner of a product can be reduced, and a great restriction is imposed on a design and a shape of a product. An object of the present invention is to provide a method for manufacturing a member for a push button switch that does not occur .
[0005]
[Means for Solving the Problems]
In the present invention, in order to achieve the above object, there is provided a method for manufacturing a member for a push button switch, comprising a molding die for molding a molded product by clamping a concave mold and a convex mold, and using the molding mold. ,
When a convex mold is formed in the same or similar shape to the shape of the molded article using an elastic body, and when the flexible film is drawn by the concave mold and the convex mold, the convex mold is formed in the concave mold through the flexible film. In this case, the member for the push button switch is manufactured by heating the concave mold .
[0006]
Note that the forming temperature of the concave mold can be set to ± 40 ° C. of the heat deformation temperature of the flexible film.
[0007]
Here, the convex shape in the claims can be formed into a shape similar to the shape of the molded product using an elastic body, but can also be formed in the same shape as the shape of the molded product. In this case, it is necessary to form the concave mold in a shape similar to the shape of the molded product. Mold, mobile phone, car phone, remote control, OA equipment, computers, Suitable for molding the pushbutton switch element such as a game device is not in any way limited to this, and various substrates such as film or sheet It can be widely used when forming into irregularities.
[0008]
According to the present invention, the concave mold and the convex mold are clamped, and the convex mold made of a polymer compound is deformed through the flexible film so as to elastically adhere to the concave mold, and the flexible film is formed along the concave mold. Since the drawing is performed by drawing, the shape can be formed in detail on the tip end surface or the like of the molded product or can be formed precisely.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3 , the forming dies of the method for manufacturing a member for a push button switch according to the present embodiment are opposed to each other so as to be able to come and go. A concave mold 1 and a convex mold 3 are provided. Among these concave molds 1 and convex molds 3, the convex mold 3 is formed to have the same shape or a similar shape to the shape of the push button switch member by using an elastic body. Forming is performed.
[0010]
The concave mold 1 is formed by using, for example, iron, an aluminum alloy, a copper alloy, or the like, and each corner in the concave portion 2 is roundly chamfered to prevent cracks and cracks (see FIG. 1). The concave portion 2 is formed in the same shape as the shape of the member for the push button switch, and fits with the protrusion 4 of the convex shape 3.
[0011]
As shown in FIG. 1, the convex mold 3 is formed by using a flexible elastic body that can be compressed and deformed, in other words, using a predetermined elastomer or rubber. Fit. The convex mold 3 is made of a material having excellent shape reproducibility, specifically, a room temperature-curable silicone rubber excellent in heat resistance, cold resistance, chemical resistance, compression set characteristic, operating temperature range, or the like, or heat resistance, oil resistance. A push button switch member formed by molding a fluoro rubber having excellent hardness, chemical resistance, solvent resistance, etc., to a hardness of 30 ° to 90 ° and each corner of the protruding portion 4 having a trapezoidal cross section being rounded and chamfered. It is molded into a shape similar to the shape of
[0012]
The reason why the hardness of the convex mold 3 is in the above range is that when the hardness is less than 30 °, the projections 4 are not sufficiently deformed and tightly fitted in the recesses 2 of the concave mold 1 and a shape defect occurs. Conversely, if the hardness exceeds 90 °, the shape following ability of the protrusion 4 is deteriorated, and a shape defect occurs, or it becomes difficult to form the convex mold 3.
[0013]
The protrusion 4 of the convex 3 is formed so as to be higher than the height of the member for the push button switch by about 0 to 2.0 mm. The reason why the height H of the protrusion 4 (the same applies to the depth of the concave portion 2) is in this range, because if it is in this range, the shape stability during molding is excellent and the quality is stable. On the other hand, if the thickness exceeds 2.0 mm, the projections 4 are excessively deformed and tightly fitted in the recesses 2 of the concave mold 1, which may cause printing failure of the pattern 6, and the like. The width A of the projection 4 in the plane direction (the same applies to the width of the recess 2) is formed to be narrower by about 0 to 1.0 mm than the width of the push button switch member. The reason why the width A of the protruding portion 4 is in the above range is that if it is in this range, the positional accuracy of the pattern 6 and the shape reproducibility during molding are excellent, and the quality is stable.
[0014]
In the above configuration, when manufacturing a member for a push button switch, first, on the surface of the flexible film 5, a pattern 6 composed of characters, numerals, symbols, and the like is printed in a layer by screen printing, gravure printing, or offset printing. (See FIG. 3). As the flexible film 5, a polyethylene terephthalate (PET) film, a nylon (PA) film, a polycarbonate (PC) film, a PC alloy film, or the like can be used. After the pattern 6 is printed on the flexible film 5 in this manner, the normal temperature flexible film 5 is arranged on the concave mold 1.
[0015]
Next, the concave mold 1 and the convex mold 3 are clamped, and the convex mold 3 is elastically adhered to the concave mold 1 via the flexible film 5, and the flexible film 5 is appropriately drawn along the concave mold 1 and drawn (FIG. 1) and then heating the concave mold 1 to manufacture a member for a push button switch. The molding conditions at this time are preferably such that the pressure value is 10 to 80 kg / cm ² and the molding temperature of the concave mold 1 is ± 40 ° C. of the heat deformation temperature of the flexible film 5. This is because when the molding temperature is lower than the value in the range, a problem occurs in the molding of the shape, and when the molding temperature is higher than the value in the range, the deterioration of the flexible film 5 becomes remarkable. Because.
If a cooling step is appropriately provided as necessary as part of the molding operation, the shape memory function can be promoted, and the responsiveness to a complicated shape can be further improved.
[0016]
After the member for the push button switch is manufactured, the mold is opened, the member for the push button switch is taken out, and the member for the push button switch is fitted via an adhesive to the surface of a base material (not shown) previously molded with silicone rubber or the like. Cover. Thereby, a push button switch can be obtained.
[0017]
According to the above configuration, the flexible film 5 is not simply drawn by the concave mold 1 and the convex mold 3, but the convex mold 3 is elastically adhered to the concave mold 1 via the flexible film 5 without any excess or shortage. Since the concave mold 1 is heated, the followability of the shape of the flexible film 5 is significantly improved. Therefore, the shape can be formed in detail and precisely on the tip end surface of the protrusion of the push button switch member. In addition, the radius of the corner can be set to the minimum R = 0.5 mm or less. Further, since even the small pattern 6 can be formed and determined accurately, the degree of freedom of the design and the product shape of the member for the push button switch can be greatly improved.
[0018]
In the above embodiment, the flexible film 5 is arranged on the concave mold 1, and the concave mold 1 and the convex mold 3 are clamped and drawn, but the present invention is not limited to this. For example, when the flexible film 5 is arranged on the concave mold 1, the concave mold 1 can be depressurized to bring the flexible film 5 into close contact with the concave portion 2, clamped, and formed by drawing. In addition, after manufacturing the member for the push button switch, the member for the push button switch is not adhered to the surface of the molded base material through an adhesive, but the fluidity is formed after the flexible film 5 is drawn. It is also possible to inject a resin and injection-mold a base material to integrate them.
[0019]
【Example】
Hereinafter, an example of a method for manufacturing a member for a push button switch according to the present invention will be described.
Example 1
On the surface of the flexible film 5 having a thickness of 125 μm, a pattern 6 composed of characters, numerals, symbols, patterns, etc. was screen-printed, and the flexible film 5 at room temperature was placed on the concave mold 1. As the flexible film 5, a polyethylene terephthalate film (manufactured by Teijin, trade name: Tetron SLA grade) was used, and as the ink, HIPET ink (manufactured by Jujo Chemical, trade name) was used.
[0020]
Next, the concave mold 1 and the convex mold 3 having the same shape as the product are clamped to make the convex mold 3 elastically adhere to the concave mold 1 via the flexible film 5, and the flexible film 5 is moved along the concave mold 1. Then, the concave mold 1 was pressurized and heated to produce a member for a push button switch. The convex mold 3 was made of silicone rubber having a hardness of about 40 °. The height H of the projection 4 of the projection 3 was 2.0 mm higher than the height of the product shape, and the width A of the projection 4 was 1.0 mm narrower than the width of the product shape. The molding temperature of the concave mold 1 was 110 ° C.
Examination after manufacturing confirmed that the tip end surface of the push button switch member was equal to the product shape.
[0021]
Example 2
On the surface of the flexible film 5 having a thickness of 50 μm, a pattern 6 composed of characters, numerals, symbols, patterns, and the like was gravure-printed, and the normal-temperature flexible film 5 was disposed on the concave mold 1. A nylon film (trade name, Amilan, manufactured by Toray) was used as the flexible film 5, and Univia NT ink (trade name, manufactured by Dainippon Ink) was used as the ink.
[0022]
Next, the concave mold 1 and the convex mold 3 having the same shape as the product are clamped to make the convex mold 3 elastically adhere to the concave mold 1 via the flexible film 5, and the flexible film 5 is moved along the concave mold 1. Then, the concave mold 1 was pressurized and heated to produce a member for a push button switch. The convex mold 3 was made of silicone rubber having a hardness of about 80 °. The height H of the projection 4 of the convex 3 was 0 to 0.8 mm higher than the height of the product shape, and the width A of the projection 4 was 0 to 0.3 mm narrower than the width of the product shape. The molding temperature of the concave mold 1 was 100 ° C.
Examination after manufacturing confirmed that the tip end surface of the push button switch member was equal to the product shape.
[0023]
Example 3
On the surface of the flexible film 5 having a thickness of 150 μm, a pattern 6 including characters, numerals, symbols, patterns, and the like was offset-printed, and the flexible film 5 at normal temperature was placed on the concave mold 1. As the flexible film 5, a polycarbonate film (manufactured by Bayer, trade name: macro hole film) was used, and as the ink, Lisorex SP ink (trade name, manufactured by Dainichi Seika) was used.
[0024]
Next, the concave mold 1 and the convex mold 3 having the same shape as the product are clamped to make the convex mold 3 elastically adhere to the concave mold 1 via the flexible film 5, and the flexible film 5 is moved along the concave mold 1. After pressing and heating the concave mold 1, it was cooled to produce a member for a push button switch. The convex mold 3 was made of silicone rubber having a hardness of about 30 °. The height H of the projection 4 of the projection 3 was 0.8 mm higher than the height of the product shape, and the width A of the projection 4 was 0.1 mm smaller than the width of the product shape. The molding temperature of the concave mold 1 was 150 ° C.
Examination after manufacturing confirmed that the height of the protrusion of the member for a push button switch was about 6 mm higher, and that a member for a push button switch with high shape reproducibility could be obtained.
[0025]
Example 4
On the surface of the flexible film 5 having a thickness of 100 μm, a pattern 6 composed of characters, numerals, symbols, patterns, and the like was screen-printed, and the room-temperature flexible film 5 was placed on the concave mold 1. As the flexible film 5, a PC alloy film (manufactured by Bayer, trade name: bi-hole film) was used, and as the ink, HIT ink (manufactured by Jujo Chemical, trade name) was used.
[0026]
Next, the concave mold 1 and the convex mold 3 having the same shape as the product are clamped to make the convex mold 3 elastically adhere to the concave mold 1 via the flexible film 5, and the flexible film 5 is moved along the concave mold 1. After pressing and heating the concave mold 1, it was cooled to produce a member for a push button switch. The convex 3 was made of silicone rubber having a hardness of about 60 °. The height H of the projection 4 of the projection 3 was 0.8 mm higher than the height of the product shape, and the width A of the projection 4 was 0.6 mm narrower than the width of the product shape. The molding temperature of the concave mold 1 was set to 140 ° C.
Examination after manufacture confirmed that the height of the protrusion of the member for a push button switch was about 12 mm higher, and that a member for a push button switch having a very complicated shape and high reproducibility could be obtained.
[0027]
【The invention's effect】
As described above, according to the present invention, the convex shape is elastically adhered to the concave shape via the flexible film, and the concave shape is heated, so that the shape following property of the flexible film is improved. Therefore, the shape can be formed relatively precisely on the protruding tip surface of the product, and the radius of the corner of the product can be reduced. Further, it is possible to effectively prevent a great restriction from occurring in the design and shape of the product.
[Brief description of the drawings]
FIG. 1 is an explanatory sectional view showing an embodiment of a method for manufacturing a member for a push button switch according to the present invention.
FIG. 2 is a sectional view showing a molding die in the embodiment of the method for manufacturing a member for a push button switch according to the present invention .
FIG. 3 is an explanatory perspective view showing a flexible film in the embodiment of the method for manufacturing a member for a push button switch according to the present invention.
FIG. 4 is an explanatory perspective view showing a mobile phone and a push button switch thereof.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 concave type 2 concave portion 3 convex type 4 protrusion 5 flexible film A width of protrusion H height of protrusion

Claims (2)

A method for manufacturing a member for a push button switch using the molding die, comprising a molding die for molding a molded product by clamping the concave mold and the convex mold,
  A convex mold is formed in the same or similar shape to the shape of a molded product using an elastic body. A method for manufacturing a member for a push button switch, wherein the member for a push button switch is manufactured by heating the concave mold by deforming and contacting. 2. The method for manufacturing a member for a push button switch according to claim 1, wherein the forming temperature of the concave mold is set to ± 40 ° C. of the thermal deformation temperature of the flexible film.

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