Method for producing ornament

In this method for producing an ornament (1), wherein an ornamental sheet (3) is bonded/affixed by means of a vacuum-press-bonding method to the convex front surface (21) of a substrate (2) provided with a convex front surface (21) and a concave back surface (22), a work-support base (6) is placed on a work placement surface (121a) formed on the upper surface of the suction chamber (120) of a vacuum-press-bonding device (100), and the substrate (2) is positioned by fitting an engagement protrusion (28) formed on the back surface of the substrate (2) covered by the ornamental sheet (3) to an engagement hole (68) at the work-support surface (61) formed on the upper surface of the work-support base (6). When bonding/affixing the ornamental sheet (3) to the substrate (2) by means of the vacuum-press-bonding device (100), position deviation of the substrate (2) is prevented by the engagement of the engagement hole (68) and the engagement protrusion (28).

TECHNICAL FIELD

The present invention relates to a method for producing an ornament, wherein an ornament is produced by bonding/fixing an ornamental sheet to the convex front surface of a substrate having a convex front surface and a concave back surface. More specifically, the present invention relates to a method for producing an ornament wherein an ornamental sheet can be bonded/fixed to the convex front surface of a substrate without positional misalignment.

BACKGROUND ART

As methods for creating a high-class appearance in the interior panels of automobiles, the panels of audio equipment, the box portions of music boxes, the panel portions of furniture, and the like; there are known methods of finishing these portions in the front surfaces of wood patterns. Examples of methods for doing so include methods of bonding/fixing an ornamental sheet to the front surface of a substrate by using a vacuum press bonding method. Patent Documents 1 to 4 propose methods for bonding/fixing an ornamental sheet to the front surface of a substrate by using a vacuum press bonding method.

In the vacuum press bonding method disclosed in Patent Document 1, a workpiece comprising an ornamental sheet placed on the front surface of a substrate via an adhesive is placed on a workpiece mounting surface formed on the top surface of a suction chamber, a pressure chamber is lowered from above, and the ornamental sheet is pressed onto the substrate front surface by a flexible pressure sheet constituting the bottom surface of the pressure chamber. In this state, the pressure of the pressure chamber is increased to firmly pressure-bond the pressure sheet to the ornamental sheet and the workpiece mounting surface, and the pressure of the suction chamber is reduced to evacuate the space between the pressure sheet and the workpiece mounting surface via a suction hole formed in the workpiece mounting surface. The ornamental sheet thereby becomes pressed against the substrate surface with the pressure sheet firmly bonded to the ornamental sheet, and the ornamental sheet is bonded/fixed to the substrate surface by an adhesive.

In the vacuum press bonding methods disclosed in Patent Documents 2 to 4, a base for mounting a substrate is placed on the top surface of a suction chamber where a suction hole is formed, and a substrate and ornamental sheet are placed on the base. This makes it possible for the pressure sheet of the pressure chamber to be firmly bonded to a workpiece, encompassing a portion from the outer periphery to the rear surface, and the outer peripheral edge portion of the ornamental sheet can be reliably bonded/fixed to the substrate, encompassing a portion from the outer peripheral edge to the back surface.

PRIOR ART DOCUMENTS

Patent Documents

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

The vacuum press bonding methods disclosed in Patent Documents 1 to 4 are for bonding/fixing an ornamental sheet to the front surface of a substrate having a flat bottom surface. Because the bottom surface of the substrate is flat, the substrate can be stably placed on a workpiece mounting surface or a base for mounting a workpiece. Therefore, when the pressure chamber is lowered and the ornamental sheet and the substrate are pressed together by the pressure sheet, there is no positional misalignment of the substrate. Because the bottom, surface of the substrate is flat, when the pressure of the suction chamber is reduced to cause evacuation via the suction hole formed in the workpiece mounting surface, the substrate can be reliably chucked by suction to the workpiece mounting surface. Therefore, there is no positional misalignment of the substrate when the pressure of the pressure chamber is increased and the pressure sheet is pressed against the ornamental sheet on the substrate. There is accordingly no positional misalignment between the substrate and the ornamental sheet, and the ornamental sheet can therefore be properly bonded/fixed to a predetermined position on the substrate front surface.

However, in the case of a plate-shaped substrate in which the front surface is convex and the back surface is concave, there is little contact surface area between the concave back surface of the substrate and the flat workpiece mounting surface, and when the pressure sheet of the pressure chamber is pressed onto the substrate front surface from above the ornamental sheet, horizontal force is readily applied to the substrate. Therefore, when the pressure chamber is lowered and the pressure sheet is pressed onto the ornamental sheet on the substrate, horizontal force acts on the substrate on the workpiece mounting surface and the substrate position is readily misaligned. Particularly in cases such as when the flat shape of the substrate is bilaterally asymmetrical as seen from the pressure direction of the pressure sheet, and when the cross-sectional shape of the substrate is bilaterally asymmetrical as sectioned along the pressure direction of the pressure sheet, horizontal force readily acts on the substrate when the pressure sheet is pressed onto the substrate front surface from above the ornamental sheet.

When positional misalignment of the substrate has occurred, there is no problem if the ornamental sheet moves together with the substrate. However, at the point in time when the pressure sheet is pressed onto the ornamental sheet on the substrate, there are often instances where the adhesive is not exhibiting an adhesive function, the ornamental sheet to which the pressure sheet is firmly bonded does not move, and the position of only the substrate is misaligned.

In the case of a plate-shaped substrate such as one having a concave back surface, when the pressure of the suction chamber is reduced to evacuate the space between the workpiece mounting surface and the pressure sheet, the concave substrate back surface cannot be reliably chucked by suction to the flat workpiece mounting surface. A problem is therefore encountered in that the position of the substrate is readily misaligned on the workpiece mounting surface when the pressure sheet of the pressure chamber is pressed against the substrate from above the ornamental sheet while the pressure of the suction chamber is reduced to cause evacuation.

As is disclosed in Patent Documents 2 to 4, such positional misalignment of the substrate occurs also when the base for mounting the workpiece is placed on the to surface of the suction chamber and the substrate is placed on the based. Particularly, when the substrate is placed on the base for mounting the workpiece, the substrate comes to be disposed in a position raised above the top surface of the suction chamber. As a result, when the pressure chamber is lowered and the pressure sheet is pressed onto the ornamental sheet on the substrate and the top surface of the suction chamber, the substrate is pressed with greater force than in cases in which the substrate is placed on the top surface. Consequently, the position of the substrate is readily misaligned greatly.

The base for mounting the workplace is chucked by suction to the top surface of the suction chamber, but the substrate placed on top of the base for mounting the workpiece is not chucked by suction to the base. Therefore, when the pressure sheet of the pressure chamber is pressed against the substrate from above the ornamental sheet while the pressure of the suction chamber is reduced to create evacuation, there is a risk that the position of the substrate on the base will be misaligned it will not be possible to bond/fix the ornamental sheet to the predetermined position on the substrate front surface.

In the case of a plate-shaped substrate such as one having a concave back surface, when the pressure sheet of the pressure chamber is pressed against the substrate from above the ornamental sheet while the pressure of the suction chamber is reduced to create evacuation, another problem is that the substrate readily deforms.

An object of the present invention is to provide a method for producing an ornament, wherein an ornament is produced by bonding/fixing an ornamental sheet by a vacuum press bonding method to the convex front surface of a substrate having a convex front surface and a concave back surface, and the ornamental sheet can be bonded/fixed to the convex front surface of the substrate without any positional misalignment.

Means to Solve the Problems

To solve the problems described above, the present invention provides a method for producing an ornament in which an ornamental sheet is stacked and bonded on the convex front surface of a substrate having a convex front surface and a concave back surface, the method for producing an ornament characterized in comprising:

an ornamental sheet overlaying step for preparing a workpiece having an ornamental sheet positionally aligned and covering the convex front surface of the substrate via an adhesive;

a workpiece mounting step for placing a workpiece support base on a workpiece mounting surface formed on the top surface of a suction chamber in a vacuum press bonding apparatus, and placing the workpiece on a workpiece support surface formed on the top surface of the workpiece support base;

a pressure sheet pressing step for lowering a pressure chamber relative to the suction chamber, the pressure chamber being disposed directly above the suction chamber in the vacuum press bonding apparatus, and pressing a flexible pressure sheet which defines the bottom surface of the pressure chamber onto the ornamental sheet of the workpiece and the workpiece mounting surface from above; and

an ornamental sheet bonding step for increasing the pressure in the pressure chamber to cause the ornamental sheet to be pressed against the convex front surface of the substrate from above by the pressure sheet, reducing the pressure in the suction chamber to evacuate a space between the workpiece mounting surface and the pressure sheet via an air intake hole formed in the workpiece mounting surface, and bonding/fixing the ornamental sheet to the convex front surface of the substrate by the adhesive;

the workpiece support base having a flat bottom surface portion capable of firmly bonding to the workpiece mounting surface, the convex workpiece support surface having a shape complementary to the concave back surface of the substrate, and a support-base-side engaging part formed in the workpiece support surface;

a substrate-side engaging part capable of mechanically engaging in the support-base-side engaging part being formed in the concave back surface of the substrate;

the workpiece being positioned relative to the workpiece support surface in the workpiece mounting step by mechanically engaging the substrate-side engaging part in the support-base-side engaging part; and

positional misalignment of the substrate relative to the workpiece support surface being prevented in the pressure sheet pressing step by the mechanical engaging of the support-base-side engaging part and the substrate-side engaging part.

The workpiece support surface of the workpiece support base used in the method for producing an ornament of the present invention has a convex shape complementary to the concave back surface of the substrate. Consequently, the substrate of the workpiece can be placed in a stable state on the workpiece support surface. The substrate is not deformed by the pressure force acting from the pressure sheet in the ornamental sheet bonding step.

Furthermore, when the workpiece is placed on the workpiece support surface, the substrate is positioned relative to the workpiece support surface by causing the substrate-side engaging part formed in the concave back surface of the substrate of the workpiece to mechanically engage with the support-base-side engaging part. Therefore, when the workpiece is placed on the workpiece support surface, the workpiece can be positioned in a simple manner. There is also no positional misalignment of the workpiece relative to the workpiece support surface even if external force is exerted on the workpiece by the mechanical engaging of the substrate-side engaging part and the support-base-side engaging part. Therefore, in the pressure sheet pressing step and the ornamental sheet bonding step, there is no positional misalignment of the substrate even if horizontal force is exerted on the substrate by the pressure force exerted on the workpiece from the pressure sheet.

Therefore, according to the method for producing an ornament of the present invention, the ornamental sheet can be bonded/fixed using a vacuum press bonding method without the position of the ornamental sheet being misaligned relative to the convex front surface of the substrate.

For the substrate-side engaging part, an engaging protuberance protruding from the concave back surface of the substrate can be formed, and for the support-base-side engaging part, an engaging hole into which the engaging protuberance can be fitted can be formed opening in the workpiece support surface.

To position the workpiece and prevent positional misalignment of the substrate, a plurality of engaging protuberances are preferably formed, and a plurality of engaging holes into which the engaging protuberances can be fitted are preferably formed. To position the workpiece and ensure positional misalignment of the substrate can be reliably prevented, the cross-sectional shapes of the engaging protuberances and the engaging holes may be polygonal.

Next, a frame-shaped spacer is preferably disposed on the workpiece mounting surface in a state of enclosing the workpiece support base placed on the workpiece mounting surface, and in the pressure sheet pressing step, the pressure chamber is preferably lowered and the pressure sheet is preferably pressed from above onto the ornamental sheet of the workpiece and the frame-shaped spacer disposed on the workpiece mounting surface.

Doing so makes it possible to reduce the workpiece pressing force by the pressure sheet in the pressure sheet pressing step. As a result, positional misalignment of the substrate can be suppressed, and positional misalignment of the workpiece support base on the workpiece mounting surface can be prevented.

Next, there are cases in which the convex front surface of the substrate to which the ornamental sheet is bonded is provided with a first outer peripheral edge portion which faces directly upward perpendicular to the workpiece mounting surface or at an upward incline, and a second outer peripheral edge portion which faces directly horizontal parallel to the workpiece mounting surface or at a downward incline, when the substrate has been placed on the workpiece support surface. In this case, the workpiece support surface of the workpiece support base is preferably a surface having an overhanging surface portion which hangs outward past the outer peripheral edge of the first outer peripheral edge portion of the substrate, and a retracted surface portion which is retracted inward from the second outer peripheral edge portion of the substrate, when the workpiece has been placed.

In the pressure sheet pressing step, in the first outer peripheral edge portion side of the substrate, the pressure sheet is pressed in a firmly bonded state onto the ornamental sheet and the end surfaces of the substrate, from the outer peripheral edge portion of the ornamental sheet covering the first outer peripheral edge portion to the overhanging surface portion of the workpiece support surface. Therefore, in the ornamental sheet bonding step, the edge end portions of the ornamental sheet can be reliably bonded/fixed to the edge ends of the first outer peripheral edge portion of the substrate.

Similarly, in the pressure sheet pressing step, in the second outer peripheral edge portion side of the substrate, the pressure sheet is pressed in a firmly bonded state onto the ornamental sheet and the end surfaces of the substrate, from the outer peripheral edge portion of the ornamental sheet covering the second outer peripheral edge portion to the retracted surface portion f the workpiece support surface. Therefore, in the ornamental sheet bonding step, the edge end portions of the ornamental sheet can be reliably bonded/fixed to the edge ends of the second outer peripheral edge portion of the substrate.

MODE FOR CARRYING OUT THE INVENTION

Embodiments of the method for producing an ornament of the present invention are described below with reference to the drawings.

First,FIG. 1is referenced to describe an ornament produced by the production method of the present invention. The ornament1shown inFIG. 1is a member constituting an interior panel of an automobile, a panel of audio equipment, the box portion of a music box, a panel portion of furniture, or the like, and the ornament has a substrate2which defines the shape of the ornament1and an ornamental sheet3bonded/fixed to the substrate2by an adhesive4.

The substrate2has an overall prismoidal shape composed of plate members of substantially constant thickness, and comprises a convex front surface21and a concave back surface22. The substrate2is a molded article made of a resin or a metal, and in the case of a metal, a metal material made of aluminum, an aluminum alloy, magnesium, or a magnesium alloy can be used.

The substrate2comprises a top plate26, and four side plates27(side plates27a,27b,27c,27d) protruding toward a concave back surface22from the outer peripheral edge of the top plate26. Of the four side plates27, the side plate27aextends at an incline to the back surface from the outer peripheral edge of the top plate26. The distal end of the side plate27ais a first outer peripheral edge portion2awherein the front surface faces upward at an incline. The side plate27bextends at an incline to the back surface from the outer peripheral edge of the top plate26, and the distal end thereof is bent downward. This distal end is a second outer peripheral edge portion2bwherein the front surface faces directly horizontal.

The ornamental sheet3is composed of a veneer sheet or the like, and is bonded to the convex front surface21of the substrate2by the adhesive4so as to cover the entire top plate26and the side plates27. Specifically, the bonding of the ornamental sheet3reaches the edge ends of the first outer peripheral edge portion2aand the second outer peripheral edge portion2b,and the ornamental sheet is bonded by the adhesive4so as to entirely cover the side plates27, as shown by the single-dash line3A inFIGS. 1(a) and (b).

Engaging protuberances28(substrate-side engaging parts) are formed in the concave back surface22side of the substrate2. The engaging protuberances28are molded at the same time as the main body portion of the substrate2on the concave back surface22side of the top plate26when the substrate2is molded. The protruding height of the engaging protuberances28from the concave back surface22is fairly small in comparison with the side plates27, and the engaging protuberances therefore do not cause any hindrance even when left in the completed ornament1. One or more engaging protuberances28can be formed, and in the present example, two columnar engaging protuberances28are formed in positions separated by a predetermined distance.

Next,FIG. 2is referenced to describe an example of a workpiece support base suitable for use in the production of the ornament1. The workpiece support base6shown inFIG. 2is a base made of a solid resin, wood, or a metal, and is used in order to place the substrate2covered by the ornamental sheet3when the ornamental sheet3is bonded/fixed to the convex front surface21of the substrate2by a vacuum press bonding method described hereinafter. The workplace support base6comprises a bottom surface69composed of a flat surface, and a convex workpiece support surface61having a convex shape (a prismoidal shape) complementary to the concave back surface22of the substrate2.

The workplace support surface61comprises a top surface part66which overlaps the top plate26of the substrate2and bears the concave back surface22side of the top plate26, and formed in this top surface part66are two engaging holes68(support base-side engaging parts) for fitting in the engaging protuberances28formed in the concave back surface22of the substrate2. In the present example, the entire bottom surface69of the workpiece support base6is a fiat surface, and a concavity may be formed in part of the flat bottom surface69. Another option is that the center portion of the bottom surface69be a flat surface, and the outer peripheral portion of the bottom surface69be an inclined surface that is inclined upward.

The workpiece support base6has on the top surface a side surface67athat overlaps the side plate27aof the substrate2and bears the concave back surface22side of the side plate27a,and the side surface67aextend at a downward incline from the outer peripheral edge of the top surface part66. The length dimension of the side surface67ais greater than the length dimension of the side plate27aof the substrate2. Therefore, the workpiece support surface61of the workpiece support base6is provided with an overhanging surface portion6ain the side where the first outer peripheral edge portion2ais positioned in the convex front surface21of the substrate2, and the overhanging surface portion6ahangs outward past the edge end of the first outer peripheral edge portion2aby a dimension d1.

The workplace support base6also comprises a side surface67bthat overlaps the side plate27bof the substrate2and bears the concave back surface22side of the side plate27b.In the side surface67b,there is a downward bend in bottom end portion of the portion extending at a downward incline from the outer peripheral edge of the top surface part66, corresponding to the shape of the side plate27b,and this bottom end portion is a side surface portion6b(a receded surface portion) which faces directly horizontal. The side surface portion6bis in a position which, when the substrate2is placed on the workpiece support surface61of the workpiece support base6, is receded inward by a dimension d2from the second outer peripheral edge portion2bin the convex front surface21of the substrate2.

FIG. 3is referenced to describe an example of a vacuum press bonding apparatus suitable for used in the method for producing an ornament of the present invention.FIG. 3(a) is an explanatory drawing showing a state in which a workpiece having the convex front surface21of the substrate2covered with the ornamental sheet3via the adhesive4is placed on the workpiece support base of the vacuum press bonding apparatus,FIG. 3(b) is an explanatory drawing showing a state in which a pressure chamber comprising a pressure sheet has been lowered, after which the pressure of the pressure chamber has been increased to press the pressure sheet onto the ornamental sheet, andFIG. 3(c) is an explanatory drawing showing a state in which the pressure of a suction chamber has been reduced to evacuate the space between the workpiece mounting surface and the pressure sheet.

Referring toFIG. 3(a) for the description, a vacuum press bonding apparatus100has a pressure chamber110connected to the distal end of a rod113of a raising/lowering device112composed of a cylinder device or the like, and a suction chamber120fixed so as to face the pressure chamber110. The pressure chamber110comprises a flexible pressure sheet111affixed so as to close the lower opening. The pressure sheet111is a rubber elastic film made of silicon rubber or the like, and the pressure sheet is heat resistant and stretchable.

The ceiling surface of the pressure chamber110is provided with one or more heaters115. The side surface of the pressure chamber110is provided with a supply/exhaust tube116for supplying and expelling air to and from the pressure chamber110. An air supply apparatus (not shown) such as a compressor is connected to the supply/exhaust tube116via a three-way valve or the like. In addition to a compressor or the like, the air supply apparatus comprises a heating device for heating the supplied air, and heated air is supplied to the pressure chamber110via the supply/exhaust tube116. The heating device of the air supply apparatus and the heaters115are controlled in terms of power supply amounts, power supply times, and other factors, and their generated heat amounts are controlled.

The suction chamber120has a box shape open at the top, and the top opening is sealed by a plate-shaped workpiece mounting base121containing numerous air intake holes123. The top surface of the workpiece mounting base121constitutes a flat workpiece mounting surface121a.In the side surface of the suction chamber120is formed a supply/exhaust tube126for evacuating and supplying air to the suction chamber120. An air supply apparatus (not shown) such as a vacuum pump is connected to the supply/exhaust tube126via a three-way valve or the like. The pressure in the suction chamber120can be reduced and air can be supplied to the suction chamber120via the supply/exhaust tube126.

FIGS. 3 and 4are referenced to describe an example of a production method whereby an ornament1is produced using the vacuum press bonding apparatus100.FIG. 4is an enlarged partial cross-sectional view showing an enlargement of a part ofFIG. 3(c).

First, as is shown inFIG. 2(b), a workpiece10is prepared on the convex front surface21of the substrate2, the position of the workpiece being aligned over the ornamental sheet3to cover the sheet via the adhesive4(ornamental sheet overlapping step). To be more specific, a spray gun or the like is used to coat the convex front surface21side of the substrate2with the liquid adhesive4, after which the ornamental sheet3is laid thereon and the position is aligned so that the front surface of the ornamental sheet3lightly traces the convex front surface21of the substrate2. The ornamental sheet3is a veneer sheet in which a back surface sheet made of nonwoven fabric, paper, or the like is attached to a veneer obtained by thinly slicing natural wood, for example, to a thickness of 0.25 mm, for example, and the ornamental sheet is cut to a predetermined size to match the size of the substrate2. The adhesive4is a thermosetting or thermoplastic adhesive, and possible examples include a urethane-based adhesive, an epoxy-based adhesive, a rubber-based adhesive, a melamine-based adhesive, a phenol-based adhesive, an acryl-based adhesive, a cyano-based adhesive, and the like.

Next, the workpiece support base6is placed on the workpiece mounting surface121aformed on the top surface of the suction chamber120in the vacuum press bonding apparatus100, and the workpiece10is placed on the workpiece support surface61formed on the top surface of the workpiece support base6, as shown inFIG. 3(a) (workpiece mounting step).

Specifically, the workpiece support base6is placed on the workpiece mounting surface121aof the vacuum press bonding apparatus100. The workpiece10, which comprises the ornamental sheet3covering the convex front surface21of the substrate2, is placed on the workpiece support surface61of the workpiece support base6. Because the bottom surface69of the workpiece support base6is a flat surface, the workpiece support base6is mounted in a stable state on the workpiece mounting surface121a.In this state, the bottom surface69of the workpiece support base6overlaps one or more air intake holes123. The engaging protuberances28are also fitted into the engaging holes68of the workpiece support surface61. This mechanical engaging causes the workpiece10to be positioned on the workpiece support surface61.

Furthermore, the overhanging surface portion6aof the workpiece support surface61hangs outward past the first outer peripheral edge portion2ain the side where the first outer peripheral edge portion2ais positioned in the convex front surface21of the substrate2. The side surface portion6bof the workpiece support surface61is in a position retracted inward from the second outer peripheral edge portion2bof the convex front surface21of the substrate2.

The pressure chamber110, which is disposed directly above the suction chamber120in the vacuum press bonding apparatus100, is then lowered relative to the suction chamber120, and the flexible pressure sheet111defining the bottom surface of the pressure chamber110is pressed from above onto the ornamental sheet3of the workpiece10and the portion of the workpiece mounting surface121athat surrounds the ornamental sheet, as shown inFIG. 3(b) (pressure sheet pressing step). During this time, the interior of the pressure chamber110is kept at ordinary pressure.

Next, the pressure in the pressure chamber110is increased and the ornamental sheet3is pressed against the convex front surface21of the substrate2from above by the pressure sheet111, as shown by the arrow inFIG. 3(b). Specifically, heating air is supplied to the pressure chamber110by the air supply apparatus via the supply/exhaust tube116, and the pressure sheet111is pressed onto the workpiece10. At the same time, the pressure of the suction chamber120is reduced, the space between the workpiece mounting surface121aand the pressure sheet111is evacuated via the air intake holes123formed in the workpiece mounting surface121a,and the ornamental sheet3is bonded/fixed to the convex front surface21of the substrate2by the adhesive4, as shown inFIG. 3(c) (ornamental sheet bonding step).

To be more specific, the air supply apparatus reduces the pressure in the suction chamber120via the supply/exhaust tube126. As a result, the space between the workpiece mounting surface121aand the pressure sheet111is evacuated via the air intake holes123, and the space between the workpiece10and the pressure sheet111is therefore reduced in pressure, as shown inFIG. 3(c). Therefore, the pressure sheet111deforms along the workpiece10and the shape of the workpiece support base6. Consequently, the pressure sheet111is firmly bonded to the front surface of the ornamental sheet3at a pressure of several to several tens of kg/cm2, for example, uniformly pressurizing the ornamental sheet3toward the substrate2, and the ornamental sheet3is therefore uniformly pressed onto the convex front surface21of the substrate2. The workpiece support base6is also reliably chucked by suction to the workpiece mounting surface121a.

During this time, the interior of the pressure chamber110is heated by heat from the heaters115or by heating of the air by a heating device of the air supply apparatus, and the workpiece10is heated via the pressure sheet111. Therefore, the adhesive4is heated to a temperature of 100° C. or more, for example. Consequently, the fluidity of the adhesive4increases, and the ornamental sheet3is therefore uniformly pressed onto the front surface of the substrate2. Consequently, the ornamental sheet3and the substrate2are uniformly bonded via the adhesive4over a pressurizing time of about several minutes.

As can be seen fromFIG. 4, in the ornamental sheet bonding step as well, the engaging protuberances28of the substrate2of the workpiece :1.0are fitted into the engaging holes68in the side of the workpiece support base6. Even if horizontal force acts on the substrate2, the position of the substrate2does not become misaligned from the workpiece support surface61by the mechanical engagement between these parts68,28.

In the workpiece support base6, the overhanging surface portion6aof the workpiece support surface61hangs outward past the first outer peripheral edge portion2ain the side of the upward-inclined substrate2where the first outer peripheral edge portion2ais positioned. Therefore, the pressure sheet111covers the first outer peripheral edge portion2aand the overhanging surface portion6ain a firmly contacted state from above, so as to span across these portions. Therefore, the ornamental sheet3is attached in a state of being reliably firmly bonded even to the first outer peripheral edge portion2a.In the side of the first outer peripheral edge portion2a,the pressure sheet111preferably deforms in conformity with the small ledge between the first outer peripheral edge portion2aand the overhanging surface portion6a,and air therefore does not remain readily between the pressure sheet111and the first outer peripheral edge portion2a.Consequently, the ornamental sheet3covers the first outer peripheral edge portion2awhile firmly bonded, and the ornamental sheet3does not wrinkle readily.

The side surface portion6bof the workpiece support surface61is retracted inward from the second outer peripheral edge portion2bof the substrate2which is oriented directly horizontal. Therefore, with the pressure sheet111wrapped in against the bottom side of the second outer peripheral edge portion2b,the second outer peripheral edge portion2bis covered from a directly horizontal direction. Therefore, the ornamental sheet3is attached in a state of being reliably firmly bonded to the second outer peripheral edge portion2b.

The evacuating of the suction chamber120is then stopped, and the supply of air to the pressure chamber110is stopped, after which the pressure chamber110is raised. The workpiece10is then taken out.

A coloring treatment that utilizes the grain of natural wood is thereafter performed as necessary on the front surface of the ornamental sheet3, and a urethane-based or polyester-based transparent coating agent, for example, is applied, and the coating agent is then solidified. The workpiece10thereby becomes an ornament having a wood-grain patterned ornamental sheet3bonded to the front surface of the substrate2. The workpiece10will be an ornament having a mirror sheen on the front surface if the front surface of the coating agent is also polished and buffed as necessary.

Because only the ornamental sheet3can be seen from the front surface of the workpiece10, which is thus configured with the ornamental sheet3bonded/fixed to the convex front surface21of the substrate2, the workpiece can be used as an attractive wood grain ornament1regardless of whether the substrate2is a plastic molded article or a metal molded article.

In the present example, after the pressure chamber110is lowered, the pressure of the pressure chamber110is increased, after which the pressure of the suction chamber120is reduced. Another option instead, after the pressure chamber110is lowered, is to begin evacuating the suction chamber120and then begin supplying air to the pressure chamber110. Another option after the pressure chamber110has been lowered is to evacuate the suction chamber120and supply air to the pressure chamber110simultaneously.

(Another Example of Vacuum Press Bonding Apparatus)

FIG. 5contains explanatory drawings showing another example of a vacuum press bonding apparatus suitable for use in the method for producing an ornament of the present invention, and a method for producing an ornament using this vacuum press bonding apparatus. Because basic configuration of the vacuum press bonding apparatus is the same as the vacuum press bonding apparatus100described above, common portions are denoted by the same symbols and descriptions thereof are omitted.

The vacuum press bonding apparatus100A shown inFIG. 5has a pressure chamber110connected to the distal end of a rod113of a raising/lowering device112, and a suction chamber120fixed so as to face the pressure chamber110, and the pressure chamber110includes a pressure sheet111affixed so as to close the lower opening. The pressure sheet111is a rubber elastic film made of silicon rubber or the like, and the pressure sheet is heat resistant and stretchable. The ceiling surface of the pressure chamber110is provided with one or more heaters115that use infrared rays or far infrared rays. The suction chamber120comprises a workpiece mounting base121.

In the vacuum press bonding apparatus100A configured in this manner, a workpiece10, which has an ornamental sheet3covering the convex front surface21side of a substrate2, is placed on a workpiece support surface61of a workpiece support base6, which is placed on a workpiece mounting surface121a.Frame-shaped spacers128are provided to the workplace mounting surface121ain positions where the spaces protrude toward the pressure chamber110and can contact the peripheral frame portions of the bottom surface of the pressure chamber110. The frame-shaped spacers128are provided to the entire periphery of the outer peripheral ends of the workpiece mounting surface121a.The frame-shaped spacers128may be configured as part of the workpiece mounting base121, and other members may be attached to the workpiece mounting surface121a.In any case, sufficient airtightness is ensured between the workpiece mounting surface121aand the frame-shaped spacers128. When the pressure chamber110lowers and contacts the frame-shaped spacers128, sufficient airtightness is ensured between the pressure sheet111of the pressure chamber110and the frame-shaped spacers128.

When an ornament1is produced using the vacuum press bonding apparatus100A shown inFIG. 5, the same steps are performed as in the case described referring toFIGS. 3 and 4. After the pressure sheet pressing step has been performed, as shown inFIG. 5(b), because the frame-shaped spacers128are provided to the suction chamber120, the pressure chamber110stops at a position that is higher by the height of the frame-shaped spacers123than in the case shown inFIG. 3. Therefore, even when the workpiece10is disposed at a higher position as seen from the workpiece mounting surface121adue to the use of the workpiece support base6, the force applied to the workpiece10can be reduced by the pressure sheet111when the pressure sheet111touches the workpiece10or when the pressure sheet111is pressed onto the workpiece10. In other words, the pressure force can be reduced to approximately the same pressure force as when the workpiece10is placed directly on the workplace mounting surface121a.Therefore, positional misalignment of the substrate2on the workpiece support base6can be reliably prevented. Consequently, the ornamental sheet3can be bonded at a predetermined position on the front surface of the substrate2without any positional misalignment.

Other Embodiments

In the examples described above, a plurality of columnar engaging protuberances28are provided, and a plurality of engaging holes68are provided into which the plurality of engaging protuberances28are fitted. Another option instead is to employ a structure in which one or more engaging protuberances28are fitted into one engaging hole68. In this case, the engaging holes68are slits or square holes, and positional misalignment in which the substrate2turns about the engaging protuberance28is preferably prevented.

Instead of columnar engaging protuberances28, plate-shaped or prismatic engaging protuberances28may be employed, and to fit with such engaging protuberances28, the engaging holes68may be slits or squares of the same shape as the engaging protuberances. In this case, even if there is only one engaging protuberance28and one engaging hole68, it is possible to prevent positional misalignment in which the substrate2rotates about the engaging protuberance28.

In the examples described above, the engaging protuberances28are formed in the substrate2and the engaging holes68are formed in the workpiece support base6. It is possible to conversely form the engaging protuberances in the workpiece support base6and form the engaging holes in the substrate2.

Next, in the examples described above, an example is described in which the first outer peripheral edge portion2aof the substrate2faced upward at an incline, but when the first outer peripheral edge portion2afaces directly upward, the overhanging surface portion6amay be provided hanging outward in the workpiece support base6past the first outer peripheral edge portion2a.In the examples described above, an example is described in which the second outer peripheral edge portion2bfaces directly horizontal, but when the second outer peripheral edge portion2bfaces downward at an incline, a configuration may be employed in which a retracted surface portion retracted inward from the second outer peripheral edge portion is provided to the workpiece support base6.

In the examples described above, a single workpiece support base6is placed on the workpiece mounting surface121aand a single workpiece10is placed thereon. Another option instead is to place a plurality of workpiece support bases6on the workpiece mounting surface121aand place the workpiece10on these workpiece support bases6. A workpiece support surface capable of carrying a plurality of workpieces10can also be used as the workpiece support surface of the workpiece support base6.

When an ornamental sheet3matching the size and shape of the substrate2is prepared, slits may be provided in the portions overlapping the corners of the substrate2to prevent wrinkles and the like.