JP2006137165A - Interference material and vacuum forming method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interference material for allowing a thermoplastic sheet material to follow the corner part of a mold at the time of vacuum forming. <P>SOLUTION: In a vacuum forming machine constituted so that the thermoplastic sheet material 2 is put in the space between the mold 3 having the corner part 3A and the cover 11 for covering the mold 3 and the heated thermoplastic sheet material 2 is closely brought into contact with the mold 3 by sucking the space between the mold 3 and the cover 11 by a vacuum pump 13, the interference material 1 is used for pressing the sheet material 2 to the corner part 3A of the mold 3. The interference material 1 has not only stretchability but also the heat resistance against the heating temperature of the sheet material 2 and is formed into a sheetlike state having an uneven cross section. This interference material 1 is extended by the suction of the pump in a state that it is put in the space between the sheet material 2 and the cover 11 corresponding to the corner part 3A to press the sheet material 2 to the mold. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an interference material used when a softened thermoplastic sheet material is closely attached to a mold having a corner portion to form a molded product having a corner portion, and a vacuum forming method using the interference material. It is.

  Resin parts such as vehicle instrument panels and consoles can be molded using a vacuum forming machine. As a vacuum forming apparatus, there is known an apparatus for molding the resin component by bringing a softened thermoplastic plastic film or sheet (hereinafter referred to as a thermoplastic sheet material) into close contact with a mold.

  Examples of the thermoplastic sheet material used in such an apparatus include a soft polyvinyl chloride film, a hard polyvinyl chloride sheet, a cellulose acetate film, a polyethylene film, and a polyacrylic resin plate. As the mold, aluminum, its alloy, epoxy resin, or the like is used, and the mold is provided with a number of holes for evacuating the space between the thermoplastic sheet material.

  Further, the vacuum forming apparatus is provided with a heater for heating the thermoplastic sheet material. As this heater, an infrared lamp heater, a nichrome wire heater, a gas heater, or the like can be used. The vacuum used in the vacuum forming apparatus is a low vacuum, and various vacuum pumps are used.

  In such a conventional vacuum forming apparatus, a thermoplastic sheet material placed on a mold is heated and softened, and then a vacuum is evacuated between the thermoplastic sheet material and the mold by a vacuum pump. Resin parts are molded by bringing a plastic sheet material into close contact with the mold.

  For example, in the conventional vacuum forming operation, as shown in FIG. 13, the thermoplastic sheet material 2 is placed on the mold 3 in the silicon forming bag 11 having the suction port 11A at one end, After the thermoplastic sheet material 2 is softened by a heater, the internal air is sucked from the suction port 11A by a vacuum pump to bring the thermoplastic sheet material 2 into close contact with the mold 3.

However, in the conventional vacuum forming apparatus, as shown in FIG. 14, a gap S <b> 2 is generated between the corner portion 20 </ b> A of the molded product 20 and the corner portion 3 </ b> A of the mold 3, and the corner portion 20 </ b> A of the molded product 20 is formed. It could not be accurately molded.
In order to eliminate such a shortage of molding, the thermoplastic sheet material 2 is raised by increasing the heating temperature or by opening holes 3B in the corner 3A of the mold 3 as shown in FIG. However, since there is a limit in any case, it is difficult to accurately form the corner 20A of the molded product 20 depending on the work.

  In view of the above, the present invention aims to provide an interference material for causing the thermoplastic sheet material 2 to follow the corner portion 3A of the mold 3 during vacuum forming, and a vacuum forming method using the interference material. And

  In order to achieve the above-mentioned object, the present invention puts a thermoplastic sheet material between a mold having a corner portion and a cover covering the mold, and vacuums the heated sheet material between the mold and the cover. An interference material that presses the sheet material against the corner of the mold in a vacuum forming apparatus that adheres to the mold by suction with a pump, and has elasticity and heat resistance against the temperature at which the sheet material is heated. The sheet material is formed into a sheet shape with an uneven section, and the sheet material is pressed against the mold while extending by suction of a vacuum pump in a state of being inserted between the sheet material and the cover corresponding to the corner portion. It is said.

  The interference material according to the present invention has a spirally raised top and a recessed bottom. In addition, as an interference material, you may use what formed the top part and the concave bottom part which rose concentrically from the center alternately. Further, in the interference material of the present invention, a streak-like groove is formed in the top and the bottom, or a cavity is formed in the top and the bottom along the ridgeline of the top and the extending direction of the bottom. It is desirable that

  In addition, the interference material of the present invention may include a plurality of pyramids protruding upward and / or downward, or may be configured by opening a plurality of holes. The interference material is made of, for example, silicon rubber.

  In order to achieve the above object, the present invention provides a thermoplastic sheet material between a mold having a corner portion and a cover covering the mold, and the heated sheet material is placed between the mold and the cover. Is a vacuum forming method for adhering to a corner of a mold by sucking with a vacuum pump, which has elasticity and heat resistance to the temperature at which the sheet material is heated, and has a sheet shape with irregularities in the cross section The interference material formed on the sheet is placed between the sheet material and the cover corresponding to the corner portion, and the sheet material is heated and softened, and then sucked by a vacuum pump. It is characterized by being pressed against the mold.

  Alternatively, in order to achieve the above object, the present invention provides a mold and a sheet material having a corner portion in a molded bag having elasticity and heat resistance to a temperature at which the thermoplastic sheet material is heated. Is a vacuum forming method in which the heated sheet material is closely attached to the corner of the mold by sucking the space between the mold and the molding bag with a vacuum pump, which has elasticity and heats the sheet material The interference material formed into a sheet shape having heat resistance with respect to the temperature and having an uneven section is placed between the sheet material and the molded bag corresponding to the corner portion, and the sheet material is heated and softened. The sheet material is pressed against the mold while the interference material extends by sucking the inside of the molding bag later by a vacuum pump.

In the present invention, the interference material is deformed by suction of the vacuum pump. That is, since the interference material formed in a sheet shape has a concavo-convex cross section, the bottom surface in contact with the thermoplastic sheet material and / or the top surface in contact with the cover, and the thermoplastic sheet material and / or Alternatively, gaps are defined between the cover and the cover, and the air in these gaps is sucked by a vacuum pump, thereby deforming so as to be in close contact with the thermoplastic sheet material or the cover. The influence of suction by such a vacuum pump works not only on the thermoplastic sheet material and cover but also on the interference material, so that the thermoplastic sheet material is also pressed against the mold by receiving the force from the interference material. .
Thus, according to the present invention, when the thermoplastic sheet material is pressed against the interference material together with the cover, the thermoplastic sheet material comes into close contact with the mold, and the thermoplastic sheet material also comes into close contact with the corner portion of the mold. Become.

  According to the present invention, the thermoplastic sheet material can be accelerated following the mold, so that a high-quality molded product can be manufactured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing a vacuum forming apparatus 10 using an interference material 1 according to an embodiment of the present invention. The vacuum forming apparatus 10 is connected to a silicon forming bag 11 having a suction port 11A and a suction port 11A. The vacuum hose 12 is formed, a vacuum pump 13 connected to the molding bag 11 through the vacuum hose 12, and a heater (not shown).
In such a vacuum operation in the vacuum forming apparatus 10, the thermoplastic sheet material 2 is placed on the mold 3 in the forming bag 11. Here, a corner portion 3A is formed in the mold 3, and a thermoplastic sheet material 2 is brought into close contact with the corner portion 3A to form a corner portion in a molded product.

  Such a configuration is the same as that of a conventional vacuum forming apparatus. However, in the vacuum forming apparatus 10 according to the embodiment of the present invention, the interference material 1 is mounted on the thermoplastic sheet material 2 in the molding bag 11. The vacuum forming operation is performed.

  The interference material 1 has heat resistance to the temperature at which the thermoplastic sheet material 2 is heated and has elasticity, and is formed into a sheet shape from, for example, silicon rubber. In the example shown in FIG. 1, it is placed on the thermoplastic sheet material 2 corresponding to the corner portion 3A of the mold 3 and is formed with a size smaller than that of the thermoplastic sheet material 2. The magnitude | size of 1 is not limited to this, You may form in the same dimension as the thermoplastic sheet material 2 so that the whole upper surface of the thermoplastic sheet material 2 may be covered.

  Then, the interference member 1 has, for example, a plan view, as shown in FIG. 2, a top portion 1 </ b> A that is slightly raised from the center and a recessed bottom portion 1 </ b> B in a spiral shape, or a concentric shape from the center as shown in FIG. 3. It is formed in a ripple shape in which a top portion 1A and a concave bottom portion 1B which are slightly raised are alternately formed.

  Further, the interference material 1 has a concave-convex shape in cross section. Specifically, as shown in FIGS. 4A and 4B, the top 1A and the concave bottom are uniformly raised with a uniform thickness. 4B is formed in a wave shape with a rounded shape, and when the air in the molded bag 11 is sucked by the vacuum pump 13, for example, as shown in FIG. It can be easily deformed flat.

  In addition, as shown in FIGS. 5A and 5B, the interference member 1 has a uniform thickness and a cross-section formed into a wave shape in which a raised top portion 1A and a recessed bottom portion 1B are linearly connected. In this case as well, the interference material 1 is deformed flat as shown in FIG. 5C so as to be aligned with the flat surface of the mold, for example, under the influence of the suction of the vacuum pump 13. Can do.

  As other shapes of the interference material 1, as shown in FIGS. 6 (A) and 6 (B), it is configured in a corrugated sheet shape as in FIG. 4, and stripe-like grooves 1C1, 1C1 are formed on the top 1A and the bottom 1B. 1C2 or as shown in FIGS. 7 (A) and 7 (B), in the corrugated sheet-like interference material 1 of FIG. 4, the ridge line and the bottom 1B of the top 1A are included in the top 1A and the bottom 1B. The cavity 1D may be formed along the extending direction. As described above, when the interference material 1 is provided with the grooves 1C1 and 1C2, the groove 1C1 of the top portion 1A is crushed and the groove 1C2 of the bottom portion 1B is expanded as shown in FIG. When 1D is provided, the cavity 1D is deformed as shown in FIG. 7C, and the interference member 1 is easily bent during suction by the vacuum pump 13.

  Furthermore, in addition to the shape shown in FIGS. 2 and 3, the interference member 1 may be one in which pyramids 1 </ b> E are aligned in the front-rear and left-right directions as shown in FIG. 8. As shown in FIG. 5B, the cross section is formed in a concavo-convex shape so that the thickness is uniform and the tops of the pyramids protrude vertically. Further, as shown in FIGS. 9A and 9B, the interference member 1 has a shape in which a plurality of pyramids 1E are aligned on the upper surface of the sheet so as to protrude only above the sheet, as shown in FIGS. As shown in FIG. 5, the pyramid 1 </ b> E may protrude from the top surface and the bottom surface of the sheet.

  In the above description, the case where the interference member 1 includes the top 1A and the pyramid 1E as the portion protruding upward is illustrated, but the interference member 1 includes a plurality of protrusions on the sheet instead of including the protrusion portion as illustrated in FIG. The hole 1F may be formed.

A vacuum forming method using the interference member 1 configured as described above will be described.
First, as shown in FIG. 1, a mold 3, a thermoplastic sheet material 2, and an interference material 1 are placed in a molding bag 11. At this time, the interference material 1 is placed on the thermoplastic sheet material 2 corresponding to the corner 3 </ b> A of the mold 3.

  Next, the thermoplastic sheet material 2 is heated by a heater (not shown). When the thermoplastic sheet material 2 is softened, the air in the molding bag 11 is sucked by the vacuum pump 13 through the suction port 11A. By this suction, the molding bag 11 is drawn to the mold 3 as the inside of the molding bag 11 is sucked.

  At this time, the gap S1 originally formed between the interference material 1 and the thermoplastic sheet material 2 is closed by the deformation of the interference material 1 by the suction of the vacuum pump 13. That is, due to the suction action of the vacuum pump 13, the thermoplastic sheet material 2 is pressed against the mold 3 while the interference material 1 is in close contact with the thermoplastic sheet material 2 as shown in FIG. As a result, the thermoplastic sheet material 2 is pressed by the interference material 1 and comes into close contact with the mold 3, and the thermoplastic sheet material 2 also comes into contact with the corner portion 3 </ b> A of the mold 3.

  Thus, by disposing the interference material 1 according to the embodiment of the present invention between the thermoplastic sheet material 2 and the molded bag 11, the thermoplastic sheet material is extended while the interference material 1 is extended by the vacuum pump 13. Since 2 is pressed against the mold 3, the thermoplastic sheet material 2 can be sufficiently adhered to the corner portion 3 </ b> A of the mold 3. Therefore, by using the interference material 1, the corners of the molded product can be accurately molded.

  Further, when the interference material 1 shown in FIGS. 6 and 7 is used, the interference material 1 can be easily deformed because the grooves 1C1, 1C2 and the cavity 1D are formed in the top 1A and the bottom 1B. Thus, the adhesion between the interference material 1 and the thermoplastic sheet material 2 is improved, and the thermoplastic sheet material 2 can be sufficiently pressed against the corner portion 3A of the mold 3 by the interference material 1.

  In addition to the above description, the present invention can be implemented in various forms without departing from the spirit of the invention. For example, the shape of the interference material 1 is merely an example, and when it is put in the molded bag 11, a gap S 1 is formed between the thermoplastic sheet material 2, and the gap S 1 is closed by suction of the vacuum pump 13. Any shape that can deform and press the thermoplastic sheet material 2 against the mold 3 may be used.

  In the above description, the vacuum forming apparatus 10 in which the interference material 1, the thermoplastic sheet material 2, and the mold 3 are placed in the forming bag 11 is illustrated, but the present invention is not limited to the forming bag 11. Of course, the interference member 1 can be used in other vacuum forming apparatuses.

  For example, as another vacuum forming apparatus, a box opened upward instead of the forming bag 11 and a lid (lid) for closing the opening of the box are provided, and a support base for placing a mold in the box is provided. The lid includes a frame and a cover stretched in the frame to cover the mold. The cover stretched on the frame has elasticity and heat resistance against the temperature at which the thermoplastic sheet material 2 is heated. As a method of using such an apparatus, the mold 3 is placed on a support base, the mold 3 is covered with a thermoplastic sheet material 2, and the interference material 1 is placed at a position corresponding to the corner portion 3A. Close the opening of the box. Then, after the thermoplastic sheet material 2 is softened by the heater, the air in the box is sucked by the vacuum pump 13, so that the cover is drawn to the mold side as in the vacuum forming apparatus 10. At that time, the interference material 1 is also deformed as described above, and the thermoplastic sheet material 2 can be pressed against the corner portion 3 </ b> A of the mold 3.

  As described above, the present invention is not limited to the molded bag 11 but can be used as long as it can create a vacuum between the mold and the thermoplastic sheet material 2. That is, according to the present invention, the vacuum between the mold 3 on which the thermoplastic sheet material 2 is placed and the cover covering the mold 3 is brought into close contact with the mold 3 by applying a vacuum. It can be applied to a molding apparatus.

  The forming bag 11 in the vacuum forming apparatus 10 is an example of the cover of the present invention, and the case where the forming bag 11 is configured as an integral body is illustrated. It is configured to be separable into a lid-like upper part of the bag that overlaps the lower part of the bag, and is configured so that the lower part of the bag and the upper part of the bag overlap to define a space for accommodating the mold 3 etc. It may be.

  The mold 3 is of course provided with a large number of holes for drawing the thermoplastic sheet material 2, but the adhesion of the thermoplastic sheet material 2 at the corner 3 </ b> A of the mold 3 is improved. Therefore, a hole 3B penetrating the mold 3 may be opened in the corner portion 3A of the mold 3 as shown in FIG.

  Furthermore, the use of a silicon rubber sheet as the interference material 1 is exemplified, but instead of the silicon rubber sheet, it has heat resistance against the temperature when the thermoplastic sheet material 2 is heated. Of course, it is possible to use a sheet-like material that is made of a stretchable material, has a cross-section formed in a concavo-convex shape, and the concavo-convex shape is deformed flat by suction of a vacuum pump.

It is a figure which shows the vacuum forming apparatus using the interference material which concerns on embodiment of this invention. It is a top view which shows the interference material which concerns on embodiment of this invention. It is a top view which shows the interference material which concerns on embodiment of this invention. (A) is a perspective view of the interference material which concerns on embodiment of this invention, (B) is the sectional view on the AA line of (A), (C) is a figure which shows an example of the deformation | transformation state. (A) is a perspective view of the interference material which concerns on embodiment of this invention, (B) is the BB sectional drawing of (A), (C) is a figure which shows an example of the deformation | transformation state. (A) is a perspective view of the interference material which concerns on embodiment of this invention, (B) is CC sectional view taken on the line of (A), (C) is a figure which shows an example of the deformation | transformation state. (A) is a perspective view of the interference material which concerns on embodiment of this invention, (B) is the DD sectional view taken on the line of (A), (C) is a figure which shows an example of the deformation | transformation state. It is a top view which shows the interference material which concerns on embodiment of this invention. (A) is a perspective view of the interference material which concerns on embodiment of this invention, (B) is the EE sectional view taken on the line of (A). (A) is a perspective view of the interference material which concerns on embodiment of this invention, (B) is the FF sectional view taken on the line of (A). It is a top view which shows the interference material which concerns on embodiment of this invention. It is a figure which shows the use condition of the vacuum forming apparatus which concerns on embodiment of this invention, and shows the state which the interference material pressed the thermoplastic sheet material against the type | mold by vacuum drawing. It is a figure which shows the conventional vacuum forming apparatus. In a conventional vacuum forming apparatus, a state is shown in which a gap is generated between a thermoplastic sheet material and a corner portion of a mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Interference material 1A Top part 1B Bottom part 1C1, 1C2 Groove 1D Cavity 1E Pyramid 1F Hole 2 Thermoplastic sheet material 3 Type 3A Corner part 3B Hole 10 Vacuum forming apparatus 11 Molding bag 11A Suction port 12 Vacuum hose 13 Vacuum pump S1 Gap

Claims (9)

A thermoplastic sheet material is placed between a mold having a corner portion and a cover covering the mold, and the heated sheet material is sucked between the mold and the cover by a vacuum pump into the mold. In an intimate vacuum forming apparatus, an interference material that presses the sheet material against the corner of the mold,
It has elasticity and heat resistance to the temperature at which the sheet material is heated, and is formed into a sheet shape having irregularities in the cross section,
An interference material, wherein the sheet material is pressed against the mold while extending by suction of the vacuum pump in a state of being inserted between the sheet material and the cover corresponding to the corner portion.   The interference member according to claim 1, wherein the top part and the concave bottom part which are raised slightly are formed in a spiral shape.   The interference material according to claim 2, wherein a streak-like groove is formed in the top part and the bottom part.   The interference material according to claim 2, wherein a cavity is formed in the top portion and the bottom portion along the ridgeline of the top portion and the extending direction of the bottom portion.   The interference material according to claim 1, comprising a plurality of pyramids protruding upward and / or downward.   The interference material according to claim 1, wherein a plurality of holes are provided.   The interference material according to claim 1, wherein the interference material is made of silicon rubber. A thermoplastic sheet material is put between a mold having a corner portion and a cover covering the mold, and the heated sheet material is sucked between the mold and the cover by a vacuum pump to It is a vacuum forming method to adhere to the corner part,
An interference material having elasticity and heat resistance to a temperature for heating the sheet material, and formed in a sheet shape having irregularities in the cross section, the sheet material and the cover corresponding to the corner portion, Put between
A vacuum forming method using an interference material, wherein the sheet material is heated and softened and then sucked by the vacuum pump to press the sheet material against the mold while the interference material extends. A mold having a corner portion and the sheet material are placed in a molded bag having elasticity and heat resistance to the temperature at which the thermoplastic sheet material is heated, and the heated sheet material is used as the mold. And a vacuum forming method for adhering to a corner portion of the mold by sucking between the molding bag and a vacuum pump,
Interference material formed into a sheet shape having elasticity and heat resistance to the temperature for heating the sheet material, and having an uneven surface, the sheet material and the molded bag corresponding to the corner portion. Put between
A vacuum using an interference material, wherein the sheet material is pressed against the mold while the interference material extends by sucking the inside of the molding bag with the vacuum pump after the sheet material is heated and softened. Molding method.

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