This application claims priority from Japanese Patent Application No. 2016-248921 filed on Dec. 22, 2016. The entire contents of the priority application are incorporated herein by reference.
The present disclosure relates to a method of producing a molding product, a molding tool, and a method of producing a molding product using the molding tool.
An example of a method for forming a molding product includes forming an embossing pattern on a surface of a molding and transferring the embossing pattern to a surface of the molding product to form a design surface including a leather textured surface.
In a production of the molding product including the design surface, the forming surface of the molding may rub the design surface resulting in scratches on the design surface which may create a blur on the design surface.
The present invention was made in view of the foregoing circumstances. An object is to provide a method of producing a molding product including a leather textured design surface without rubbing of a forming surface against the design surface.
A method of producing a molding product including a non-design surface and a design surface including a leather textured surface and adjacent to the non-design surface includes: injecting molten plastic into a forming cavity of a molding tool including a first forming surface to form the non-design surface and a second forming surface to form the design surface; and blowing air toward a boundary between the non-design surface and the first forming surface until a gap is created between the non-design surface and the first forming surface and toward a boundary between the design surface and the second forming surface via a hole formed in the first forming surface until a gap is created between the design surface and the second forming surface after the injecting of the molten plastic.
According to the technology disclosed herein, a method of producing a molding product including a design surface including a leather textured surface without rubbing between the design surface and a forming surface is provided.
An embodiment will be described with reference to
The trim board 11 is made of thermosetting resin (e.g., polypropylene). The trim board 11 includes an upper board 16 and the lower board 20. The upper board 16 forms an upper section of the trim board 11. The lower board 20 forms the most of the rest of sections of the trim board 11. At the middle of the lower board 20 in the vertical direction, a step 21 that project more to the interior side of the vehicle in comparison to the upper section of the trim board 11 is provided. As illustrated in
The hole 21A has an elongated shape that extends in the front-rear direction of the vehicle (an extending direction of the armrest 12). As illustrated in
The trim board 11 is produced using a molding tool 30 illustrated in
The forming cavity S1 has a shape corresponding to a contour of the lower board 20. The cavity die 31 includes a first forming surface 41 and a second forming surface 42. The first forming surface 41 is for forming the non-design surface 24. The second forming surface 42 is for forming the design surface 23. As illustrated in
As illustrated in
The air channel component 33 has a cuboidal shape with a long dimension along a long dimension of the hold 22 (corresponding to a long dimension of the armrest 12), that is, the air channel component 33 extends in the direction in which the hold 22 extends (corresponding to the direction in which the armrest 12 extends). A side surface 33A of the air channel component 33 facing the forming cavity S1 is a section of the first forming surface 41. The grooves S3 are continuously formed in end surfaces 33B of the air channel component 33 at ends of the long dimension and the surface 33A of the air channel component 33.
The cavity die 31 includes an air canal 31B connected to a hole in the bottom wall of the recess 31A. The air canal 31B is connected to an air blower 43 (e.g., an air compressor). Sections of the grooves S3 in the side surface 33A extend in the longitudinal direction of the air channel component 33 corresponding to the extending direction in which the hold 22 extends. Sections of the grooves S3 in the end surfaces 33B extend from the air canal 31B side toward the forming cavity S1. The spaces S2 are defined by side surfaces and the end surfaces 33B of the air channel component 33 and the inner walls of the recess 31A including the bottom wall.
The air blower 43 blows air into the spaces S2 and the grooves S3 by via the air canal 31B. The air blow continues into the forming cavity S1. The width of the grooves S3 is set at a size such that the molten plastic does not flow into the grooves S3 (e.g., 0.03 mm). A distance between the adjacent grooves S3 may be set but not limited to 10 mm.
Next, the method of producing the lower board 20 will be described. The method includes an injection step, a dwelling step, a cooling step, and a blowing step.
Injection Step
As illustrated in
Dwelling Step
The dwelling step is preformed after the injection step. While the cavity die 31 and the core die 32 are held together with a force to close the molding tool 30, the injection unit 35 continues injecting the molten plastic into the forming cavity S1 after the forming cavity S1 is filled with the molten plastic in the injection step. A predefined pressure is applied to the molten plastic in the forming cavity S1 for a predefined period (e.g., a few seconds).
Cooling Step
The cooling step is performed after the dwelling step. Cooling water is passed through the cooling water canal 34 in the cavity die 31 and the core die 32 after the injection of the molten plastic by the injection unit 35 is stopped to cool down the cavity die 31 and the core die 32 for a predefined period (e.g., a few times longer than the period of the dwelling step). As a result, the molten plastic in the forming cavity S1 is cooled down and solidified, and the lower board 20 is formed. Then, the core die 32 is moved to open the cavity die 31 to remove the lower board 20. Air or oil may be used instead of the cooling water to cool down the molten plastic in the cooling step.
Blowing Step
The blowing step is performed after the dwelling step is completed and before the cooling step is completed. The air blower 43 blows air into the spaces S2 and the grooves S3 via the air canal 31B in directions indicated by arrows P1 in
Next, effects will be described. Because the jet of air creates the small gap S4 between the design surface 23 and the second forming surface 42, the design surface 23 is less likely to rub against the second forming surface 42 even if the lower board 20 contracts in a direction along the design surface 23 (the horizontal direction in
The blowing step is performed after the completion of the dwelling step and before the completion of the cooling step. Namely, the air can be blown toward the boundary between the design surface 23 and the second forming surface 42 before the lower board 20 is completely cooled down. Therefore, the jet of the air that reaches the boundary between the design surface 23 and the second forming surface 42 via the air canal 31B and the gap S5 between the first forming surface 41 and the non-design surface 24 created by the jet of air can create the gap S4 S5 between the first forming surface 41 and the non-design surface 24.
The technology described herein is not limited to the embodiment described in the above description and the drawings. The technology described herein may include the following embodiments.
(1) Molding products including design surfaces with leather textured patterns may be included in the technical scope of the present invention.
(2) The blowing step may be performed in parallel to the dwelling step. If the start of the blowing step is too early, the design surface may be concaved due to the blowing of the air. Therefore, it is preferable to start the blowing step after the design surface is and therearound are formed to an extent but before the molten plastic is completely solidified, that is, it is preferable to star the blowing step in parallel to the cooling step.
(3) The technical scope of the present invention can be applied to non-design surfaces covered with components other than the armrest (e.g., a switch base).
Number | Date | Country | Kind |
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2016-248921 | Dec 2016 | JP | national |