JP2006240191A - Vacuum molding mold and vacuum molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold and a method for vacuum molding which can certainly mold a skin material as a molding material into a predetermined undercut shape without receiving restrictions of the position or size of the portion for which the undercut shape is provided and which can certainly stick the skin material with a substrate. <P>SOLUTION: A groove 22 is formed in the side of a cavity die 20 having a protrusion 21, and an expandable tube 25 is arranged in the groove 22. A depression 31 is formed in a core 30 so as for the protrusion 21 to be inserted, and an undercut molding part 32 having a concave cross-section is formed in the side of the depression 31 that faces oppositely to the groove 22 when the dies are closed. A compressed air is injected, while the dies are being closed, into the tube 25 to inflate it. A skin material 43 is pressed against the undercut molding part 32 to certainly obtain the undercut shape and stuck to the undercut part 44a of the substrate 44 mounted on the core die 30. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum forming mold and a vacuum forming method for forming an undercut shape recessed in a direction intersecting a mold closing direction with respect to a forming material such as a skin material by vacuum suction inside the mold.

As the vehicle parts, there are molded parts such as the instrument panel 50 and the door trim shown in FIG. These molded parts are manufactured by bringing a skin material with a thermoplastic foam layer backed on the skin into close contact with a base material to be an insert placed on the mold surface while vacuum forming.
Further, the instrument panel 50 is provided with a meter hood portion 51 that is recessed so as to fit a measuring instrument such as a speedometer, and a direction in which a recess is formed as an undercut portion 51 a on a side portion of the meter hood portion 51. The undercut shape that is recessed in the direction intersecting with is formed using the following vacuum forming die.

FIG. 7 is a cross-sectional view showing one step of closing the vacuum forming die when forming the undercut shape on the skin material 43, and a vacuum forming die for forming the instrument panel 50 of FIG. FIG. FIG. 8 is a bottom view of the protrusion 111 of the cavity mold 110 in the vacuum mold of FIG.
As shown in FIG. 7, in a conventional vacuum forming mold comprising a cavity mold 110 that molds the front side of a molded product and a core mold 120 that molds the back side of the molded product, a protrusion 111 is formed on the mold surface of the cavity mold 110. The core mold 120 is formed with a recess 121 into which the protrusion 111 is inserted by closing the mold. As shown in FIG. 8, the protruding portion 111 accommodates a slide core 112 for forming an undercut shape in the molded product, a rod 113 for supporting the slide core 112, and one end of the rod 113. And a slide mechanism 114 that slides the slide core 112. The slide mechanism 114 can project the slide core 112 from the outer peripheral surface of the projecting portion 111 as indicated by an arrow in FIG. Yes. In addition, an undercut molding portion 122 that is recessed in a direction intersecting the recess direction is formed on the side portion 121a of the recess portion 121, and a space in which the slide core 112 slides and protrudes by the slide mechanism 114 is formed. ing.

  Using such a conventional vacuum mold, a molded product such as the instrument panel 50 has been manufactured as follows. First, the base material 44 serving as an insert is placed on the mold surface of the core mold 120, and the skin material 43 is disposed between the cavity mold 110 and the core mold 120 in tandem with this. Here, the skin material 43 is formed by lining the foam material 42 on the skin material 41, and is softened by being held and heated by a clamping device (not shown). Then, as shown in FIG. 7, the mold 111 is closed while sucking air between the skin material 43 and the cavity mold 110 from the vacuum suction hole provided in the cavity mold 110, and the protrusion 111 of the cavity mold 110 is closed. The slide core 112 arranged on the side is slid by the slide mechanism 114 and protruded from the side surface of the protrusion 111. Thereby, the contact part 43a to the slide core 112 in the skin material 43 is pushed into the undercut molding part 122 of the core mold 120, and the skin material 43 is shaped while forming the undercut shape of the contact part 43a. Was in close contact with the substrate 44.

FIG. 9 is a cross-sectional view showing each step of mold closing when forming an undercut shape on the skin material 43 using a vacuum forming die different from FIG.
The vacuum mold shown in FIG. 9 is different from the vacuum mold shown in FIGS. 7 and 8 in that the protrusion 111 of the cavity mold 110 is provided with a slide core, a rod, and a slide mechanism. The core mold 120 is provided with a vacuum suction hole (not shown) for sucking air between the core mold 120 and the skin material 43.

Using such a vacuum forming die, a molded product such as the instrument panel 50 has been manufactured as follows.
First, as in the case of FIG. 7, the base material 44 is placed on the mold surface of the core mold 120, and the skin material 43 is disposed between the cavity mold 110 and the core mold 120. At this time, the skin material 43 is held by a clamping device (not shown) and is softened by heating.
Next, the air between the skin material 43 and the cavity mold 110 is sucked from a vacuum suction hole (not shown) provided in the cavity mold 110, and the cavity mold 110 and the core mold 120 are narrowed to close the mold. Then, the skin material 43 is attached to the mold surface of the cavity mold 110. FIG. 9A shows this state, and the arrows shown in the figure indicate the direction of evacuation.
Then, the suction from the vacuum suction hole provided in the cavity mold 110 is stopped, and conversely, the suction from the vacuum suction hole provided in the core mold 120 is performed. Then, as shown in FIG. 9B, a portion of the skin material 43 facing the undercut molding portion 122 of the core mold 120 enters the undercut molding portion 122, and the undercut molding of the base material 44 is performed. By trying to adhere to the front side of the undercut portion 44 a inserted into the portion 122, an undercut shape is formed on the skin material 43.
In this way, the skin material 43 was brought into close contact with the base material 44 while the undercut shape was formed on the skin material 43.

Patent Document 1 discloses a plurality of slide cores that can move a molding die independently of each other when a hollow box body is manufactured by injecting a foam heat insulating material into a hollow portion of a hollow molded product and foaming. There is disclosed a technique which is configured and provided with a deep protrusion with respect to the opening by using vacuum suction together.
Patent Document 2 discloses a molding technique for molding an undercut portion without using a slide core.
JP 59-184625 A Japanese Patent No. 2672733

  However, in the vacuum forming mold shown in FIG. 7, it is necessary to provide the slide core 112, the rod 113, and the slide mechanism 124 on the protrusion 111 of the cavity mold 110. Therefore, it is necessary to have a size sufficient to arrange these in the protruding portion 11. For example, as shown in FIG. 8, the length b in the longitudinal direction of the slide core with respect to the length a in the longitudinal direction of the protrusion 111 of the cavity mold 110 is required to be about ½. Further, it is restricted by the arrangement position of the cavity mold 110 on the protrusion 111.

Further, in the vacuum forming technique shown in FIG. 9, since the slide core 112 or the like is not provided on the projecting portion 111 of the cavity mold 110, the degree of freedom of the shape to be shaped increases, but there are the following problems. .
FIG. 10 is a cross-sectional view illustrating the problems in each step shown in FIG. 9, (A) is an enlarged view of the circled portion shown in FIG. 9 (B), and (B) is this It is sectional drawing which showed typically a mode that it removes through a process and arrange | positions mounting goods 60, such as instruments.
As shown in FIG. 10 (A), the portion of the skin material 43 that contacts and presses against the mold surface of the cavity mold 110 is thinly stretched, while the portion that becomes the undercut shape becomes non-contact, Since no pressing pressure is applied, the substrate 44 is not in close contact and is not thinned. Therefore, even if it tries to arrange | position the mounting goods 60, such as instruments, in a meter hood part, as shown in FIG.10 (B), the flange part 61 of the mounting goods 60 and the undercut part 43a of the skin material 43 interfere, There is a possibility that the undercut portion 44a of the meter hood portion may not enter.
In addition, when the skin material 43 comes into contact with the mold surfaces of the cavity mold 110 and the core mold 120, the temperature of these molds is usually lower than the temperature of the skin material 43, so that the temperature of the skin material 43 is lowered to a predetermined shape. It becomes difficult to mold. Therefore, the skin material 43 cannot be shaped into a predetermined undercut shape or the skin material 43 can be brought into close contact with the base material 44 simply by performing suction from the vacuum suction hole provided in the core mold 120. There is also a fear.

  Therefore, in view of the above problems, the present invention can reliably form a skin material as a molding material into a predetermined undercut shape without being restricted by the size or position of the portion that shapes the undercut shape. Furthermore, when manufacturing molded parts by vacuum forming the skin material at the same time as making contact with the base material, make sure that the undercut shape part of the skin material is in close contact with the base material to increase the yield of the molded product. An object is to provide a vacuum forming mold and a vacuum forming method that can be improved.

In order to achieve the above object, a vacuum forming mold of the present invention includes a first mold in which a protrusion is formed on a mold surface, a second mold in which a depression is formed so that the protrusion is inserted, A vacuum forming mold in which a molding material is vacuum-molded so as to form an undercut shape that is recessed in a direction intersecting the mold closing direction by sandwiching the molding material between the first mold and the second mold A groove is formed on the side of the projecting portion of the first mold, a tube is disposed in the groove, and the concave portion of the second mold has a concave cross section on the side facing the groove when the mold is closed The undercut molding part is formed, and the tube is expanded in a closed state, so that the molded material is pressed into the undercut molding part by the expanded tube, and the undercut shape is shaped into the molding material. To do.
With this configuration, since the tube is disposed in the groove formed in the protruding portion of the first mold, the outer peripheral surface of the tube comes into contact with the molding material by expanding the tube after closing the mold, and molding Since the contact portion of the material enters the undercut molding portion of the second mold and further presses the contact portion with the outer peripheral surface of the tube, an undercut shape can be formed on the molding material.
Preferably, the second mold is provided with a vacuum suction hole for sucking air between the molding material. With this configuration, when the tube is expanded, the undercut is efficiently cut into the molding material by sucking the air between the molding material and the second die from the vacuum suction hole formed in the second die. The shape can be shaped.

On the other hand, the vacuum forming method of the present invention includes a first mold in which a groove is formed in a side portion of a protruding portion formed on a mold surface and a tube is disposed in the groove, and a hollow portion into which the protruding portion is inserted. A second mold having an undercut molding section having a concave cross section formed in a direction intersecting the mold closing direction on the side of the first mold and the second mold. The molding material is placed in the mold, the mold is closed, and the inside of the mold is vacuum-sucked to shape the undercut shape recessed in the direction intersecting the mold closing direction, and the molding material is vacuum-formed, A step of attaching the molding material to the mold surface of the first mold by vacuuming the inside of the mold through a vacuum suction hole provided in the first mold, and providing the second mold while expanding the tube. By vacuuming the inside of the mold through the vacuum suction hole, the molding material is undercovered by the expanded tube. A step of pressing the shot molding portion to shape an undercut shape in the molding material, and carrying out.
With this configuration, in the first step, the molding material is attached to the mold surface of the first mold, the molding material is shaped along this mold surface, and the tube is expanded in the subsequent process. Since the outer peripheral surface of the tube abuts on the molding material, the abutting portion of the molding material enters the undercut molding portion of the second mold, and the abutting portion is pressed by the outer peripheral surface of the tube. The undercut portion can be formed by shaping the cut shape.
In particular, the skin material is used as the molding material, and the second mold base material is placed, and by performing these steps, the contact portion of the skin material with the tube is pressed into the undercut molding portion. Thus, the skin material can be brought into close contact with the base material while forming an undercut shape on the skin material.
Preferably, the skin material is a thermoplastic material in which a foam layer is provided on the back side of the skin. With this configuration, the skin and the foamed layer can be molded integrally, and a molded product having a cushioning property can be efficiently produced by placing the foamed layer toward the base material.
The tube can be expanded by injecting compressed air into the tube from the connecting portions connected to both ends of the tube. Thereby, since a tube expand | swells efficiently, shaping | molding raw materials, such as a skin material, can be shaped in an undercut shape, and when a base material is mounted on a 2nd type | mold, it follows a base material. A skin material can be adhered.

  According to the vacuum forming die of the present invention, by closing the die and expanding the tube, the contact portion of the forming material with the tube is pressed into the undercut forming portion provided in the second die. Therefore, an undercut shape can be formed on the molding material easily and reliably. In addition, since it is not necessary to provide a slide core or the like in the vacuum mold as in the past, the time and cost required for producing the vacuum mold can be reduced, and restrictions due to the shape and size of the molded product are reduced. Various molded articles having an undercut shape can be produced.

  On the other hand, according to the vacuum forming method of the present invention, in the first step, the molding material is attached to the mold surface of the first mold, and the molding material is shaped along the mold surface. By inflating the tube, the outer peripheral surface of the tube abuts on the molding material, the abutting portion of the molding material enters the undercut molding portion of the second mold, and the abutting portion is further inserted on the outer peripheral surface of the tube. Press. Therefore, the undercut shape can be shaped into the molding material efficiently and reliably. In particular, the skin material is used as the molding material, and the second mold base material is placed, and by performing these steps, the contact portion of the skin material with the tube is pressed into the undercut molding portion. Thus, the skin material can be brought into close contact with the base material while forming an undercut shape on the skin material. Therefore, it is possible to produce a molded product having an undercut shape efficiently and reliably and integrated with the base material. Accordingly, various molded products having an undercut shape can be produced while reducing production costs and management costs due to molding defects and poor adhesion.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a main part of a vacuum forming die 10 of the present invention, and FIG. 2 is a perspective view of a protruding portion 21 of a first die 20 in the vacuum forming die 10 of FIG. A sectional view taken along line AA in FIG. 2 corresponds to FIG.
The vacuum forming die 10 of the present invention includes a cavity die 20 as a first die having a protruding portion 21 formed on the die surface, and a second portion having a recess 31 corresponding to the die surface of the cavity die 20. And a core mold 30 as a mold. As will be described later with reference to FIG. 4, the protruding portion 21 of the cavity 20 is inserted into the recessed portion 31 of the core mold 30 by closing the mold.
Here, the cross-sectional view shown in FIG. 1 assumes a vacuum forming die for forming the instrument panel 50 shown in FIG. 6 and corresponds to a cross-sectional portion along line BB in FIG. The cavity mold 20 that molds the front side is a female mold as a whole, and the core mold 30 that molds the back side of the molded product is a male mold as a whole.
And in the side part of the hollow part 31 of the male core type | mold 30, it is in the direction which cross | intersects the mold closing direction (direction shown by arrow a in FIG. 1) with respect to the unevenness | corrugation of the molded article shape | molded by mold closing. An undercut forming portion 32 is formed to form a concave cross section so as to be recessed.

More specifically, as shown in FIG. 1, the mold surface of the core mold 30 is provided with a first convex portion 33 having a triangular cross section and a second convex portion 34 having a rectangular cross section, spaced apart from each other. A recessed portion 31 is formed by being surrounded by the inner side surface 33a of the first convex portion 33, the outer side surface 34a of the second convex portion 34, and the bottom surface 31a. An undercut molding portion 32 having a concave cross section is formed on the inner side surface 33 a of the first convex portion 33.
On the other hand, the cavity mold 20 includes a first recess 23 having a triangular cross-section and a second recess 24 having a rectangular cross-section at an interval, and an inner surface 23a of the first recess 23, an outer surface 24a of the second recess 24, and The protruding portion 21 is formed as a bulge surrounded by the protruding surface 21a.
As will be described later with reference to FIG. 4, the skin material 43 is disposed between the cavity mold 20 and the core mold 30, and the mold is closed after the base material 44 serving as an insert is placed on the mold surface of the core 30. Therefore, the surfaces of the cavity mold 20 and the core mold 30 are formed in consideration of the thicknesses of the skin material 43 and the base material 44.

  In the vacuum forming die 10 of the present invention, since the undercut forming portion 32 is formed on the inner surface 33a of the first convex portion 33 that forms the recessed portion 31 of the core mold 30, this recessed portion is formed when the mold is closed. A groove 22 is formed on the side of the protruding portion 21 of the cavity mold 20 inserted into the portion 31 that faces the undercut molded portion 32, that is, on the inner surface 23a side of the first recess 23a. The formation range of the groove 22 corresponds to a range in which an undercut portion that is recessed in a direction intersecting with the uneven direction of the molded product is formed. A stretchable tube 25 is disposed in the groove 22. The tube 25 to be disposed is made of a material such as rubber or silicon, and is particularly preferably heat resistant.

FIGS. 3A and 3B are bottom views of the protruding portion 21 of the cavity mold 20 as the first mold. FIG. 3A shows a state when the tube 25 is not expanded, and FIG. 3B shows a state when the tube 25 is expanded. FIG. As shown in FIG. 3, both end portions of the tube 25 are fitted into connection portions 22 a and 22 a provided in the groove 22, and the connection portions 22 a and 22 a are electrically connected to the outside through the cavity mold 20. Compressed air can be injected into the tube 25 via the connecting portions 22a and 22a, or the air in the tube 25 can be discharged.
In a normal state in which compressed air is not injected into the tube 25, as shown in FIG. 1 and FIG. 3A, the tube 25 does not protrude from the groove 22 to the side of the protruding portion 21, and the cavity mold 20 is externally provided. By injecting compressed air into the tube 25 through the inside, the outer diameter of the tube 25 and the depth of the groove 22 are set so that the tube 25 expands and protrudes from the side portion of the protruding portion 21.
As shown in FIG. 3, the groove 22 may be formed so that both ends of the tube 25 are appropriately bent inside the cavity mold 20 and connected to the connection portion 22 a.

Next, using the vacuum forming die 10 configured as described above, an undercut shape is applied so as to intersect with the depression formed in the skin material 43 while forming the skin material 43 as a molding material. A vacuum forming method for forming will be described.
FIG. 4 is a cross-sectional view showing each step of the vacuum forming method for forming the skin material 43 as a forming material using the vacuum forming die 10 of FIG. 1, and FIG. 5 shows each step following the step shown in FIG. It is sectional drawing which showed.
First, the skin material 43 is disposed between the cavity mold 20 and the core mold 30. At this time, the skin material 43 is held by a clamp device. The skin material 43 is made of a thermoplastic material that is softened by heating. For example, the back surface of the skin 41 is lined with a foam layer 42. Here, the foam layer 42 is formed by foaming a resin or the like with, for example, a foaming agent, and is porous with cushioning properties. Before and after the disposition of the skin material 43, a base material 44 serving as a core material of the molded product is placed on the mold surface of the core mold 30. The base 44 is previously formed with a shape along the mold surface of the core mold 30, that is, a recess and an undercut portion 44 a having a concave cross section that is recessed in a direction intersecting the recess direction at a side portion where the recess is formed. It is inserted into the undercut molding part 32 of the core mold 30 (see FIG. 4A).

  Next, the space between the cavity mold 20 and the core mold 30 is reduced by moving the cavity mold 20 and the clamp device toward the core mold 30 (in the direction of arrow a shown in FIG. 4A). Then, as shown in FIG. 4A, the ridge line portion 44 b of the base material 44 located on the ridge line portion 33 b of the first convex portion 33 comes into contact with the foam layer 42 of the skin material 43. At this time, the skin material 43 comes into contact with the outer peripheral end of the projecting surface 21a of the projecting portion 21 of the cavity mold 20 and changes from a planar shape to an uneven shape.

  Subsequently, the cavity mold 20 is brought closer to the core mold 30 in the direction indicated by the arrow a in FIG. The air between the skin material 43 and the cavity mold 20 is sucked in the direction of the arrow shown in FIG. Thereby, the skin material 43 adheres along the surface shape of the 1st recessed part 23 in the type | mold surface of the cavity type | mold 20, ie, the principal part shown to FIG. 4 (B). At this time, the undercut portion 44 a of the base material 44 inserted into the undercut molding portion 32 of the core mold 30 is not in contact with the skin material 43, and also enters the groove 22 formed in the cavity die 20. Not.

Next, the suction through the vacuum suction hole provided in the cavity mold 20 is stopped, and conversely, from the vacuum suction hole (not shown) provided in the core mold 30, the direction of the arrow shown in FIG. Furthermore, the air between the skin material 43 and the core mold 30, particularly the air between the skin material 43 and the undercut molding part 32 of the core mold 30 is sucked. At the same time, the compressed air is injected into the tube 25 in the groove 22 formed on the side of the protruding portion 21 of the cavity mold 20 to expand the tube 25. The arrow shown in the hollow of the tube 25 in FIG. 5A schematically shows that the tube 25 is expanded by the pressure of compressed air.
As a result, the outer peripheral surface of the tube 25 contacts the skin material 43, and the contact portion 43 a of the skin material 43 with the tube 25 is pushed into the undercut molding portion 32 of the core mold 30 and pressed. Therefore, the contact portion 43 a of the skin material 43 can be shaped into an undercut shape, and the skin material 43 can be brought into close contact with the undercut portion 44 a of the base material 44.
Therefore, as shown in FIG. 9 in the related art, compared to the case where the undercut shape is formed on the skin material 43 only by vacuum suction, the skin material 43 can be securely brought into close contact with the base material 44. There is no risk of poor adhesion.

  Thereafter, the air injected into the tube 25 is pulled out of the cavity mold 20 through the connecting portion 22a to return to the state before the compressed air is injected, and suction is performed through the vacuum suction hole provided in the core mold 30. To stop. FIG. 5B shows this state. Then, the skin material 43 is molded from the cavity mold 20 and the core mold 30, and the molded product 45 integrated with the base material 44 is removed and removed. At this time, the tube 25 is not expanded, and the tube 25 and the undercut portion 45a of the molded product 45 can be easily removed without interfering with each other.

  As described above, the tube 25 is disposed in the groove 22 formed on the side of the projecting portion 21 of the cavity mold 20, and the undercut molding section 32 having a concave cross section is opposed to the groove 22 when the mold is closed. Since the tube 25 is expanded in a mold-closed state, the contact portion 43 a that contacts the outer peripheral surface of the tube 25 is pressed into the undercut molding portion 32 of the core die 30. And can be shaped into an undercut shape. When removing the mold, the compressed air injected into the tube 25 is removed, and the tube 25 is returned to its original state so as not to bulge out of the groove 22 so that the tube 25 is removed without being caught. be able to. Therefore, it is not necessary to provide a slide core, a slide mechanism, or the like in the cavity mold 20 as in the prior art, and an undercut shape can be formed and the substrate 44 placed on the core mold 30 can be closely attached. it can. Accordingly, the cavity mold 20 and the core mold 30 can be easily manufactured at a low cost, and the skin material is freed from restrictions on the position and size due to the provision of the slide core and the slide mechanism in the cavity mold 20. A molding material such as 43 can be molded.

As mentioned above, although this invention was demonstrated in detail about embodiment, it can change variously within the range of the invention described in the claim. In the above description, the tube 25 is disposed in the groove 22 formed in the cavity mold 20 and the undercut molding portion 32 is formed in the core mold 30, but the undercut molding portion is formed in the cavity mold to form the core mold. A groove may be formed and a tube may be disposed in the groove. In the above description, the base material 44 is placed on the core mold 30 so as to be in close contact with the base material 44 while the skin material 43 is being molded, but the base material 44 is not placed on the core mold 30. In addition, by placing a sheet-shaped molding material between the cavity mold 20 and the core mold 30 and performing mold closing, the molding material can be molded with an undercut shape.
In addition, the vacuum suction holes provided in the cavity mold 20 and the core mold 30 can form a mold with a porous material, and can form innumerable minute holes in the mold. It may be anything.

It is sectional drawing which shows the principal part of the vacuum forming die of this invention. It is a perspective view of the protrusion part of a 1st type | mold among the vacuum forming dies of FIG. It is a bottom view of the protrusion part of the cavity type | mold as a 1st type | mold. It is sectional drawing which showed each process of the vacuum forming method which shape | molds the skin material as a shaping | molding raw material using the vacuum forming die of FIG. It is sectional drawing which showed each process following the process shown in FIG. It is a perspective view of the instrument panel as a molded article. It is sectional drawing which showed one process of the mold closing of the conventional vacuum forming type | mold at the time of shaping | molding by forming an undercut shape in a skin material. It is a bottom view of the protrusion part of a cavity type | mold among the vacuum forming dies of FIG. It is sectional drawing which showed each process of mold closing at the time of shape | molding using the vacuum forming die by a prior art different from FIG. It is sectional drawing explaining the problem in each process shown in FIG.

Explanation of symbols

10 Vacuum mold 20 Cavity mold (first mold)
21 Protruding portion 21a Protruding surface 22 Groove 22a Connection portion 23 First concave portion 23a Inner peripheral surface 24 Second concave portion 24a Outer peripheral surface 25 Tube 30 Core type (second type)
31 Indented portion 31a Bottom surface 32 Undercut molding portion 33 First convex portion 33b, 44b Ridge line portion 33a Inner side surface 34 Second convex portion 34a Outer side surface 41 Skin 42 Foamed layer 43 Skin material 43a Contact portion 44 Base material 44a, 45a Under Cut section 45 Molded product 50 Instrument panel

Claims (6)

The mold includes a first mold in which a protrusion is formed and a second mold in which a recess is formed so that the protrusion is inserted, and the molding material is the first mold and the second mold. In a vacuum forming die that vacuum-forms the molding material so as to shape an undercut shape that is sandwiched between the mold and the direction that intersects the mold closing direction,
A groove is formed on the side of the protrusion of the first mold, and a tube is disposed in the groove.
An undercut molding section having a concave cross section is formed on the side facing the groove when the mold is closed among the depressions of the second mold,
A vacuum forming die characterized by inflating the tube in a closed state to press the molding material into the undercut molding portion by the expanded tube to form an undercut shape on the molding material.   The vacuum forming die according to claim 1, wherein the second die is provided with a vacuum suction hole for sucking air between the molding material. A first mold in which a groove is formed in a side portion of the projecting portion formed on the mold surface and a tube is disposed in the groove, and a mold closing direction on a side portion of the hollow portion in which the projecting portion is inserted. A vacuum forming die comprising a second die in which an undercut molding part having a concave cross section is formed in the intersecting direction, and a molding material is disposed between the first die and the second die. The mold is closed, and the inside of the mold is vacuumed to form an undercut shape that is recessed in the direction intersecting the mold closing direction, and the molding material is vacuum formed.
Attaching the molding material to the mold surface of the first mold by vacuum-sucking the interior of the mold through a vacuum suction hole provided in the first mold;
By vacuuming the inside of the mold through a vacuum suction hole provided in the second mold while the tube is expanded, the molded material is pressed into the undercut molding portion by the expanded tube to form the molding material. A process of shaping the undercut shape;
A vacuum forming method characterized by: A first mold in which a groove is formed in a side portion of the protruding portion formed on the mold surface and a tube is disposed in the groove, and a side of the hollow portion into which the protruding portion is inserted intersects the mold closing direction. And using a vacuum forming die comprising a second die having an undercut forming portion having a concave cross section in the direction to be used, and placing a skin material between the first die and the second die By closing the mold and vacuuming the inside of the mold, the skin material has an undercut shape recessed in a direction intersecting the mold closing direction, and the skin material is in close contact with the base material placed on the second mold A vacuum forming method for producing a molded article,
Attaching the skin material to the mold surface of the first mold by vacuum suction inside the mold through a vacuum suction hole provided in the first mold;
By vacuuming the inside of the mold through the vacuum suction hole provided in the second mold while the tube is expanded, the skin material is pressed into the undercut molding portion by the expanded tube, and the skin material is undercoated. And a step of closely contacting the skin material to the substrate while shaping a cut shape.   The vacuum forming method according to claim 4, wherein the skin material is a thermoplastic material in which a foam layer is provided on the back side of the skin.   The vacuum forming method according to claim 3 or 4, wherein the expansion of the tube is performed by injecting compressed air into the tube from connection portions connected to both ends of the tube.

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