JP5890758B2 - Thermoform molding method and molding apparatus - Google Patents

Description

  The present invention relates to a thermoform molding method and a molding apparatus in which a plate-like blank formed by integrating a plurality of fibers with a resin is heated to a temperature at which the resin becomes soft and is brought into close contact with a mold.

  As a thermoform molding method in which a plate-shaped blank containing a resin as a main component is heated to a temperature at which the resin becomes soft and is in close contact with the mold, (a) in a state where the plate-shaped blank is heated and softened (B) Cover the blank with compressed air by blowing it from the outside with the heated plate-shaped blank covered on the mold, and (c) Cover the mold with the heated plate-shaped blank. In such a state, a method is known in which air between the blank and the mold is discharged and the blank is adsorbed to the mold (see Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 61-179720 JP-A-6-239340

  By the way, when a plate of a composite material (for example, FRP: Fiber Reinforced Plastics, CFRP: Carbon Fiber Reinforced Plastics, etc.) in which a plurality of fibers oriented in parallel is integrated with a resin is used for the blank, the above (a), (b ) And (c), there is a problem that wrinkles occur in the product. That is, in the plate-shaped blank made of the above-described composite material, the resin can be deformed by heating, but the fibers do not stretch. Therefore, wrinkles are likely to occur as they are drawn in close contact with the mold.

  In order to suppress wrinkles of the product, it is required that the blank be closely attached to the transfer surface of the mold as much as possible. However, in any of the above methods (a), (b), and (c), it is unavoidable that the blank hits the transfer surface (the blank partially hits the transfer surface). As the blank is pulled in close contact with the transfer mold, wrinkles occur in the product.

  Diaphragm molding, hydraulic molding, and hydroforming, in which the plate blank made of the composite material described above is pressed against the transfer surface of the mold with equal force, using the liquid itself as a press punch. Molding and the like are also conceivable. However, when thermoforming is performed using these molding methods, if a plate-shaped blank made of a composite material is heated to a temperature at which the resin becomes soft, the liquid will boil, so that it does not actually hold.

  The purpose of the present invention created in view of the above circumstances is to make the blank as close to the transfer surface of the mold as possible even in a heating environment in which a plate-shaped blank made of a composite material is heated to a temperature at which the resin becomes soft. An object of the present invention is to provide a thermoform molding method and a molding apparatus that can be brought into close contact with an equal force and can suppress wrinkles.

According to the present invention created to achieve the above object, a plate-like blank formed by integrating a plurality of fibers with a resin is heated to a temperature at which the resin becomes soft, and is brought into close contact with the transfer surface of the mold. In a thermoform molding method, a heated plate-shaped blank is placed on a mold with a recessed transfer surface so as to cover the transfer surface, and a cylinder is placed with the blank sandwiched between the mold, A blank is sandwiched between the mold and the cylinder so that it can be pulled out, and a plurality of particles that can cover at least the transfer surface are accommodated in the cylinder hole of the cylinder so as to be movable relative to each other. By inserting and moving toward the transfer surface, the blank is pulled out from between the mold and the cylinder, and the pulled-out blank is brought into close contact with the transfer surface via the particles , and at this time the particles move relative to each other. While transferring the blank Thermofoam molding method characterized in that is adhered along is provided.

  In the thermoform molding method of the present invention, the particles may be metal or ceramic spheres.

  In the thermoform molding method of the present invention, a cushion plate made of a material softer than the granule is disposed on the surface of the blank that contacts the granule so as to prevent the shape of the granule from being transferred to the blank. It may be.

  In the thermoform molding method of the present invention, a release film may be disposed between the cushion plate and the blank to prevent the cushion plate from adhering to the blank.

  In the thermoform molding method of the present invention, a plurality of granules may be movably accommodated in a heat-resistant bag that can be used at a temperature at which the resin becomes soft, and the heat-resistant bag may be interposed between the pressing member and the blank. .

In addition, according to the present invention created to achieve the above object, a plate-like blank formed by integrating a plurality of fibers with a resin is heated to a temperature at which the resin becomes soft, and is brought into close contact with the transfer surface of the mold. A thermoform molding apparatus configured as described above, in which a transfer surface is recessed, a mold on which a heated plate-shaped blank is placed so as to cover the transfer surface, and a transfer surface of the mold is disposed so as to be transferred. A pressing member that moves close to and away from the surface, and a cylinder hole that is mounted so as to sandwich the blank between the mold and penetrates the end portion on the mold side and the end portion on the opposite side. A cylinder in which the end is closed with a blank and a pressing member is inserted in the opposite end, and a plurality of particles accommodated in the cylinder hole of the cylinder and capable of covering at least the transfer surface; with a use at temperatures of granules, the resin becomes soft Movably plurality housed in capacity heat bag, thermofoam molding apparatus is provided which is characterized in that the heat bag accommodated in the cylinder bore.

  In the thermoform molding apparatus of the present invention, the particles may be metal or ceramic spheres.

  In the thermoform molding apparatus of the present invention, the gap between the cylinder hole and the pressing member may be set narrower than the diameter of the granule.

  In the thermoform molding apparatus of the present invention, a cushion plate made of a material softer than a sphere may be disposed on the surface of the blank that contacts the granule.

  In the thermoform molding apparatus of this invention, you may arrange | position the release film which suppresses that a cushion board adheres to a blank between a cushion board and a blank.

  According to the present invention, the plurality of particles interposed between the pressing member and the blank are brought into close contact with the transfer surface while moving with each other, and function as a pseudo fluid. Therefore, the blank can be brought into close contact with the transfer surface with as much force as possible by the pseudo fluid effect of these particles, and the generation of wrinkles can be suppressed.

  Further, even if the granule is heated to a temperature at which the blank resin becomes soft, unlike the liquid, the granule is not restricted by the boiling point or the like, and thus can be used stably without problems even in a heating environment.

(A) is a decomposition | disassembly side sectional view which shows each component of the thermoform molding apparatus which concerns on one Embodiment of this invention, (b) is a perspective view which shows the type | mold and cylinder of a thermoform molding apparatus. (A) is sectional drawing which shows the first process of the thermoform shaping | molding method using the thermofoam shaping | molding apparatus shown in FIG. 1, (b) is sectional drawing which shows the process followed. (A) is sectional drawing which shows the process of following FIG.2 (b), (b) is sectional drawing which shows the process which continues further. It is a perspective view of the product removed from the type | mold after the process of FIG.3 (b). The 1st modification of this invention is shown, (a) is sectional drawing which shows a part of process of the thermoform shaping | molding method using the thermoform shaping | molding apparatus which concerns on a 1st modification, (b) is a cross section which shows the process followed. FIG. It is explanatory drawing which shows a 2nd modification of this invention and shows a mode that the spherical body was accommodated in the heat-resistant bag.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(Thermoform molding device 1)
FIG. 1A shows an exploded side sectional view of a thermoform molding apparatus 1 according to an embodiment of the present invention, and FIG. 1B shows a perspective view of a mold 2 and a cylinder 3 of the thermoform molding apparatus 1. . The thermoform molding apparatus 1 according to the present embodiment heats a plate-like blank B formed by integrating a plurality of fibers with a resin in advance to a temperature at which the resin becomes soft (for example, 280 to 390 ° C.). The plate-like blank B is pressed against the transfer surface 21 of the mold 2 through a plurality of particles (spheres 4) to be brought into close contact therewith.

  The thermoform molding apparatus 1 includes a mold 2 in which a transfer surface 21 is recessed and covers the transfer surface 21 and a plate-like blank B is placed thereon, and is disposed close to and away from the transfer surface 21 disposed above the mold 2. A pressing member (piston) 5 that moves, a cylinder 3 that is mounted on the die 2 so as to surround the transfer surface 21 and sandwich the blank B, is closed by the blank B, and the piston 5 is inserted at the upper end. And a plurality of metal spheres 4 housed in the housing.

(Blank B)
The blank B is made of a plate of a composite material (FRP, CFRP, etc.) in which a plurality of parallelly oriented fibers (long fibers) are integrated with a resin (polymer). In the present embodiment, the plate has an octagonal shape in plan view as shown in FIG. 1B, but may have any shape. A plurality of fibers in the composite material are oriented in a woven shape or a NCF (Non Crimp Fabric) shape. By thermoforming the blank B, for example, a part of a fan blade of a jet engine (parts such as a positive pressure side or a negative pressure side of a hollow fan blade), a nose cone, or the like is formed.

  In order to prevent the shape of the sphere 4 from being transferred to the blank B, a cushion plate C made of a material softer than the sphere 4 (rubber, resin, etc.) is disposed on the surface of the blank B on the side where the sphere 4 contacts. ing. A release film R that suppresses the cushion plate C from adhering to the blank B is disposed between the cushion plate C and the blank B. The release film R is mainly composed of naphtha (Hydrotreated Heavy Naphtha), dibutyl ether, or the like.

(Type 2)
The mold 2 on which the blank B is placed is fixed to a base (not shown), and the whole is formed in a substantially cylindrical shape. A recess 22 having a circular cross section is formed on the top surface of the mold 2, and a transfer surface 21 is formed on the bottom surface of the recess 22 so as to cover the transfer surface 21. Is placed. The transfer surface 21 has a shape to which the outer surface of a product to be thermoformed is transferred, and is a hemispherical shape in the present embodiment, but is not limited to this shape.

(Cylinder 3)
The cylinder 3 is attached to and detached from the mold 2 so as to sandwich the blank B. The outer diameter of the cylinder 3 is set according to the inner diameter of the recess 22. The cylinder 3 is formed with a cylinder hole 31 that passes through an end (lower end) on the mold 2 side and an end (upper end) on the opposite side. The cylinder hole 31 is closed at the lower end with the blank B, and the piston 5 is inserted into the upper end. The cylinder 3 is formed with a plurality of holes 32 penetrating along the axial direction so as to surround the cylinder hole 31 at intervals in the circumferential direction. Bolts 6 are inserted into the respective holes 32 from above, and a screw portion at the bottom of the bolt 6 is screwed into a screw hole 23 formed in the bottom surface of the recess 22. Thereby, as shown to Fig.2 (a), the cylinder 3 is attached to the type | mold 2 on both sides of the blank B. As shown in FIG.

  As shown in FIG. 2A, a shim (spacer) 7 is interposed between the lower surface of the lower end portion of the cylinder 3 and the bottom surface of the recess 22, and the thickness and number of the shims 7 are adjusted. Thus, the clamping force of the blank B by the bolt 6 can be adjusted. As shown in FIGS. 2B, 3A, and 3B, the clamping force of the blank B by the bolt 6 is such that the blank B comes into close contact with the transfer surface 21 via the sphere 4 by the descending piston 5. Accordingly, the blank B sandwiched between the cylinder 3 and the mold 2 is set to slide out gradually.

(Sphere 4)
A plurality of spheres 4 are accommodated in the cylinder hole 31 of the cylinder 3. The spherical body 4 is pressed by the piston 5 as shown in FIG. 2 (b), so that the blank B is moved along the transfer surface 21 of the mold 2 as shown in FIGS. 3 (a) and 3 (b). It exerts the function of pressing and adhering. The diameter of the sphere 4 is set to be equal to or larger than the gap G (for example, 1 mm) between the cylinder 3 and the piston 5 and is about 5 to 10 mm in this embodiment, but is not limited to this numerical range. . Note that the sphere 4 may be used by mixing not only one type of diameter but also a plurality of types having different diameters.

  The spheres 4 are accommodated in the cylinder 3 in a state in which at least the number that can cover at least the transfer surface 21 is gathered together so as to be movable. In addition, the sphere 4 has heat resistance that can be used even when heated to a temperature at which the resin of the blank B becomes soft (temperature at which thermoforming can be performed: for example, 280 to 390 ° C.). It is made of a material having a strength that does not break even when pressed by the pressure pressed along the transfer surface 21, for example, a metal such as steel, ceramics, or the like.

(Piston 5)
A piston 5 is disposed above the cylinder 3. The piston 5 is connected to a press device or the like, moves close to and away from the mold 2, and is inserted into and removed from the cylinder hole 31 of the cylinder 3. The outer diameter of the piston 5 is set based on the inner diameter of the cylinder hole 31.

  As shown in FIG. 2 (b), the gap G between the piston 5 and the cylinder hole 31 is set to be larger than the gap at which the piston 5 can be smoothly inserted into the cylinder hole 31 and narrower than the diameter of the sphere 4. The sphere 4 pressed by the piston 5 is prevented from being discharged to the outside through the gap G. In order to reliably avoid the situation where the sphere is caught in the gap G, it is preferable to set the gap G to be narrower than the radius of the sphere 4.

(Thermo foam molding method)
A thermoform molding method using the thermoform molding apparatus 1 described above will be described.

  First, a blank B shown in FIG. 1A is heated in advance to a temperature at which the resin becomes soft and thermoform can be formed (for example, 280 to 390 ° C.), and a release film R and a cushion plate C are attached to the blank B. 2A, a blank B, a release film R, and a cushion plate C (hereinafter referred to as a blank assembly BA) are integrated on the mold 2 so as to cover the transfer surface 21, as shown in FIG. Put. Before the blank assembly BA is placed on the mold 2, a release agent (silicone, fluorine, etc.) is applied to the transfer surface 21. Further, the blank assembly BA may be heated.

  As shown in FIG. 2A, the cylinder 3 is placed on the blank assembly BA, and the cylinder 3 is attached to the concave portion 22 of the mold 2 with the bolt 6. As a result, the blank assembly BA is sandwiched between the cylinder 3 and the mold 2. At this time, a shim 7 for adjusting the clamping force of the blank assembly BA is interposed between the lower surface of the cylinder 3 and the bottom surface of the concave portion 22 of the mold 2. As shown in FIGS. 2B, 3A, and 3B, the thickness and number of the shims 7 are such that the blank assembly BA is pressed against the transfer surface 21 via the sphere 4 by the descending piston 5. It is set so that the blank assembly BA sandwiched between the cylinder 3 and the mold 2 is gradually pulled out as it is moved. When the cylinder 3 is mounted on the mold 2, a plurality of metal spheres 4 are accommodated in the cylinder hole 31 so as to be movable relative to each other.

  Thereafter, the piston 5 is lowered and inserted into the cylinder hole 31 as shown in FIGS. 2 (b), 3 (a), and 3 (b). Then, the blank assembly BA is pressed against the transfer surface 21 of the mold 2 through the plurality of spheres 4 by the piston 5, and the spheres 4 are moved toward each other and are brought into close contact with the transfer surface 21. . Here, the plurality of spheres 4 accommodated in the cylinder hole 31 and pressed by the piston 5 slide on the respective spherical surfaces in a space defined by the lower surface of the piston 5, the inner surface of the cylinder hole 31, and the upper surface of the blank assembly BA. While moving, the blank assembly BA is pressed and adhered along the transfer surface 21 to function as a pseudo fluid. Due to the pseudo fluid effect of the sphere 4, the blank assembly BA can be brought into close contact with the transfer surface 21 with as uniform force as possible. As a result, even if the blank B of the blank assembly BA is made of a composite material in which fibers are not stretched and easily wrinkled when heated, the product can be molded while suppressing wrinkles.

  Further, the sphere 4 functioning as a pseudo fluid is made of a metal that is not subject to restrictions such as boiling point even if the resin of the blank B made of a composite material is softened and heated to a temperature capable of thermoforming (for example, 280 to 390 ° C.). So it can be used even in a heated environment. That is, the metal sphere 4 is a diaphragm-molded or liquid-formed liquid in which the liquid itself is used as a press punch (liquid punch) even when heated to a temperature at which the resin becomes soft during thermoform molding. Unlike liquids in pressure molding, hydroform molding, etc., since there is no restriction on the boiling point or the like, the function as a pseudo fluid is stably exhibited without problems even in a heating environment.

  Further, in the present embodiment, as shown in FIG. 1A, the cushion plate C made of a material softer than the sphere 4 is disposed on the surface of the blank B on the side where the sphere 4 comes into contact. Transfer of the shape of the sphere 4 to B can be suppressed. Moreover, since the release film R is arrange | positioned between the cushion board C and the blank B, it can suppress that the cushion board C adheres to the blank B. FIG.

  As shown in FIG. 3B, when the thermoforming of the blank assembly BA is completed, the piston 5 is raised, the cylinder 3 is removed from the mold 2, and the molded product is removed from the transfer surface 21. By removing the cushion plate C and the release film R from the removed molded product, a product S is obtained as shown in FIG. From the product S, a flange-shaped burr portion SB is cut off in a subsequent process.

(First modification)
A first modification of the present invention is shown in FIGS. 5 (a) and 5 (b). FIG. 5A is a cross-sectional view showing a part of the process (corresponding to FIG. 3A) of the thermoform molding method using the thermoform molding apparatus 1x according to the first modification, and FIG. 5B continues. It is sectional drawing which shows a process (equivalent to FIG.3 (b)). This modification is different from the previous embodiment in that the transfer surface 21x provided in the mold 2 is formed to have a narrower opening (stenosis) in the middle than the upper opening.

In this way, even if the transfer surface 21x is formed in the middle of the transfer surface 21x that is recessed in the mold 2 rather than the cylinder hole 31, and the transfer surface 21x has an overhanging shape, the sphere 4 pressed by the piston 5 remains in the pseudo fluid. And the blank assembly BA is brought into close contact with the transfer surface 21x with substantially equal force. Therefore, even if the blank B of the blank assembly BA is made of a composite material (FRP, CFRP, etc.), a product having an overhang shape can be accurately thermoformed while suppressing generation of wrinkles.

The mold 2 is divided by dividing surfaces along the vertical and horizontal directions, and the product is taken out from the transfer surface 21x after being divided. In this modification, the configuration is the same as that of the above embodiment except that the shape of the transfer surface 21x is an overhang shape, and the basic operational effects are the same as those of the above embodiment.

(Second modification)
As a second modification of the present invention, as shown in FIG. 6, a plurality of spheres 4 are movably accommodated in a heat-resistant bag 8 that can be used at a temperature at which the resin of the composite material softens (for example, 280 to 390 ° C.), One in which the heat-resistant bag 8 is accommodated in the above-described cylinder hole 31 is conceivable. As the heat-resistant bag 8, a glass cloth or the like can be considered. In this modification, since the plurality of spheres 4 are accommodated in the heat-resistant bag 8, the handleability of the spheres 4 is improved as compared with the above embodiment. Since this modification has the same configuration as that of the above embodiment except that the sphere 4 is housed in the heat-resistant bag 8, the basic operational effects are the same as those of the above embodiment, and detailed description thereof is omitted. To do.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various modifications within the scope of the claims. Needless to say, examples and modifications also belong to the technical scope of the present invention. For example, the bolt 6 and the shim 7 are deleted, and a pressing means (hydraulic cylinder mechanism, spring mechanism, etc.) for pressing the cylinder 3 against the bottom surface of the concave portion 22 of the mold 2 is provided instead. You may make it control the clamping force of the blank assembly BA clamped between. Moreover, you may use not only a metal sphere but a ceramic sphere and gravel with a large diameter for a granule.

  INDUSTRIAL APPLICABILITY The present invention can be used in a thermoform molding method and a molding apparatus in which a plate-like blank formed by integrating a plurality of fibers with a resin is heated to a temperature at which the resin becomes soft and is in close contact with the mold.

DESCRIPTION OF SYMBOLS 1 Thermoform shaping | molding apparatus 1x Thermoform shaping | molding apparatus 2 Type | mold 21 Transfer surface 21x Transfer surface 3 Cylinder 31 Cylinder hole 4 Sphere as a granule 5 Pushing member (piston)
8 Heat-resistant bag G Gap B Blank C Cushion plate R Release film

Claims (10)

A thermoform molding method in which a plate-like blank formed by integrating a plurality of fibers with a resin is heated to a temperature at which the resin becomes soft and is in close contact with a transfer surface of a mold,
Place the heated plate-shaped blank on the mold with the transfer surface recessed so as to cover the transfer surface,
A cylinder is placed between the mold and the blank, and the blank is clamped between the mold and the cylinder so as to be drawn out.
In the cylinder hole of the cylinder, a plurality of particles that can cover at least the transfer surface are accommodated movably.
By inserting a pressing member into the cylinder hole and moving toward the transfer surface,
The blank is pulled out from between the mold and the cylinder, the pulled blank is brought into close contact with the transfer surface via the granules,
At this time , the blank is brought into close contact with the transfer surface while the particles move to each other, and the thermoform molding method is characterized in that:   The thermoform molding method according to claim 1, wherein the granule is a spherical body made of metal or ceramics.   A cushion plate made of a material softer than the granules is disposed on the surface of the blank that contacts the granules, and the shape of the granules is suppressed from being transferred to the blank. The thermoform molding method according to claim 1 or 2.   The thermoform molding method according to claim 3, wherein a release film is disposed between the cushion plate and the blank to prevent the cushion plate from adhering to the blank.   A plurality of the particles are movably accommodated in a heat-resistant bag that can be used at a temperature at which the resin becomes soft, and the heat-resistant bag is interposed between the pressing member and the blank. 5. The thermoform molding method according to any one of 1 to 4. A thermoform molding apparatus in which a plate-like blank formed by integrating a plurality of fibers with a resin is heated to a temperature at which the resin becomes soft and is in close contact with a transfer surface of a mold,
A mold on which a transfer surface is recessed and a heated plate-like blank is placed covering the transfer surface;
A pressing member that is disposed opposite to the transfer surface of the mold and moves close to and away from the transfer surface;
The mold is mounted so as to sandwich the blank, and has a cylinder hole penetrating the end on the mold side and the end on the opposite side, and the end on the mold side of the cylinder hole is closed with the blank. A cylinder in which the pressing member is inserted at the end opposite to the peeling;
A plurality of particles accommodated in the cylinder hole of the cylinder and capable of covering at least the transfer surface;
A thermoform molding apparatus , wherein a plurality of the granules are movably accommodated in a heat-resistant bag that can be used at a temperature at which the resin becomes soft, and the heat-resistant bag is accommodated in the cylinder hole . The thermoform molding apparatus according to claim 6, wherein the granule is a spherical body made of metal or ceramics.   The thermoform molding apparatus according to claim 6 or 7, wherein a gap between the cylinder hole and the pressing member is narrower than a diameter of the granules.   The thermoform molding apparatus according to any one of claims 6 to 8, wherein a cushion plate made of a material softer than the spherical body is disposed on a surface of the blank that is in contact with the granules.   The thermoform molding apparatus according to claim 9, wherein a release film that suppresses the cushion plate from adhering to the blank is disposed between the cushion plate and the blank.

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