Decorative sheet application method and decorative sheet application machine

Abstract

To improve the design of decorative sheets attached to the body of a vehicle by pressing them with a squeegee.SOLUTION: Decorative sheet 20 is attached to the convexly curved adhesive portion 15 of the vehicle body 10. The method of attaching decorative sheet 20 comprises a contact step of bringing decorative sheet 20, which is held by holding device 31 at first portion 201, into contact with adhesive portion 15 at second portion 202 away from first portion 201, and a pressing step in which the pressing portion 40 in contact with the decorative sheet 20 is moved from the second portion 202 toward the first portion 201 to press the decorative sheet 20 onto the adhesive portion 15. In the pressing step, the holding device 31 moves toward the adhesive portion 15 so that the distance between the pressing portion 40 and the contact portion CP of the decorative sheet 20 becomes shorter.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method for attaching a decorative sheet and a decorative sheet attaching device.

Background Art

[0002] For example, as disclosed in Patent Document 1, a method of attaching a decorative sheet to an adherend portion of a vehicle body is known. An adherend portion and a decorative sheet attached to the adherend portion constitute a decorative member. In Patent Document 1, a decompression device for decompressing the space between the decorative sheet and the adherend portion is used for attaching the decorative sheet to the adherend portion. When the space between the decorative sheet and the adherend portion is decompressed, the decorative sheet is pressed against the adherend portion by the atmosphere and attached to the adherend portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to reduce the time and cost required for attachment to the adherend portion, the decorative sheet is attached to the adherend portion using a pressing portion. When the decorative sheet is attached to the adherend portion, as a pressing step, the pressing portion is moved on the decorative sheet and pressed against the adherend portion. By one pressing step, a partial region of the decorative sheet is attached to the adherend portion. The decorative sheet is attached to the adherend portion by a plurality of pressing steps.

[0005] In the decorative sheet attached to the adherend portion using the pressing portion, linear streaks were observed. The linear streaks were located at the edges of the region attached to the adherend portion by one pressing step. The design property of the decorative member deteriorated due to the conspicuous observation of the linear streaks. The present disclosure aims to improve the design property of the decorative member.

Means for Solving the Problem

[0006] A first method for attaching a decorative sheet according to an embodiment of the present disclosure is a method for attaching a decorative sheet to an adherend portion that is convexly curved on a vehicle body, a contact step of bringing the decorative sheet held by a holding device at a first portion into contact with the adherend portion at a second portion away from the first portion; a pressing step of pressing the decorative sheet against the adherend portion by moving a pressing portion that has contacted the decorative sheet from the second portion toward the first portion, and includes: In the pressing step, the holding device relatively moves with respect to the adherend portion so that the distance to the contact portion between the pressing portion and the decorative sheet becomes shorter.

[0007] A second method for attaching a decorative sheet according to an embodiment of the present disclosure is a method for attaching a decorative sheet to an adherend portion that is convexly curved on a vehicle body, a pressing step of bringing a pressing portion into contact with a decorative sheet held by a holding device at a first portion and pressing the decorative sheet against the adherend portion by moving the pressing portion toward the first portion; a moving step of relatively moving the holding device with respect to the adherend portion so that the distance to the contact portion between the pressing portion and the decorative sheet becomes shorter while the pressing portion remains in contact with the decorative sheet and stops on the decorative sheet, and includes:

[0008] A third method for attaching a decorative sheet according to an embodiment of the present disclosure is a method for attaching a decorative sheet including a bonding layer to an adherend portion of a vehicle body by a pressing portion, including a pressing step of pressing a first region of the decorative sheet against the adherend portion by moving the pressing portion that has contacted the decorative sheet; The pressing portion contacts the decorative sheet at a contact portion extending in a first direction. The pressure from the pressing portion in the contact portion decreases to half or less of the maximum value at the end in the first direction. A method of attaching a decorative sheet, wherein the full width at half maximum of the pressure from the pressing portion of the contact portion is 20% or more of the length of the contact portion in the first direction.

[0009] A decorative sheet attaching device according to an embodiment of the present disclosure is An attaching device for attaching a decorative sheet to a convexly curved adherend portion of a vehicle body, comprising a holding device for holding a first portion of the decorative sheet; a pressing portion for pressing the decorative sheet against the adherend portion, the pressing portion contacts a second portion away from the first portion of the decorative sheet, and moves from the second portion toward the first portion while in contact with the decorative sheet, the holding device moves relative to the adherend portion so that the distance to the contact portion between the pressing portion and the decorative sheet becomes shorter.

Advantages of the Invention

[0010] According to the present disclosure, the design property of the decorative member can be improved.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0012] One embodiment of the present disclosure relates to the following [1] to [9].

[0013] [1] A method of attaching a decorative sheet to a convexly curved attachment portion of a vehicle body, comprising: a contact step of bringing the decorative sheet held by a holding device at a first portion into contact with the attachment portion at a second portion away from the first portion; a pressing step of pressing the decorative sheet against the attachment portion by moving a pressing portion contacting the decorative sheet from the second portion toward the first portion; wherein, in the pressing step, the holding device moves relative to the attachment portion so that a distance to a contact portion between the pressing portion and the decorative sheet becomes shorter.

[0014] [2] A method of attaching a decorative sheet to a convexly curved attachment portion of a vehicle body, comprising: a pressing step of bringing a pressing portion into contact with a decorative sheet held by a holding device at a first portion and pressing the decorative sheet against the attachment portion by moving the pressing portion toward the first portion; a moving step of moving the holding device relative to the attachment portion so that a distance to a contact portion between the pressing portion and the decorative sheet becomes shorter while the pressing portion remains in contact with the decorative sheet and stops on the decorative sheet.

[0015] [3] The decorative sheet has a first surface and a second surface opposite to the first surface. The decorative sheet is pasted on the adherend portion from the second surface, The initial peel strength on the second surface of the decorative sheet is 0.1 N / 25 mm or more. The method for pasting a decorative sheet according to [1] or [2].

[0016] [4] The decorative sheet has a first surface and a second surface opposite to the first surface, The decorative sheet is pasted on the adherend portion from the second surface, The 60° specular gloss on the first surface of the decorative sheet is 40 or more. The method for pasting a decorative sheet according to any one of [1] to [3].

[0017] [5] The thickness of the decorative sheet is 0.1 mm or more and 1.0 mm or less. The method for pasting a decorative sheet according to any one of [1] to [4].

[0018] [6] A method for pasting a decorative sheet including a bonding layer on an adherend portion of a vehicle body by a pressing portion, Comprising a pressing step of pressing a first region of the decorative sheet against the adherend portion by moving the pressing portion that has contacted the decorative sheet, The pressing portion contacts the decorative sheet at a contact portion extending in a first direction, The pressure from the pressing portion at the contact portion decreases to half or less of the maximum value at an end portion in the first direction, The full width at half maximum of the pressure from the pressing portion of the contact portion is 20% or more of the length of the contact portion in the first direction. The method for pasting a decorative sheet.

[0019] [7] Further comprising a second pressing step of pressing a second region that at least partially overlaps the first region of the decorative sheet against the adherend portion by moving the pressing portion that has contacted the decorative sheet, The end portion of the contact portion overlaps a second contact portion where the pressing portion contacts the decorative sheet in the second pressing step, The pressure from the pressing portion on the portion overlapping with the end portion of the second contact portion is greater than the pressure from the pressing portion on the end portion of the contact portion. The decorative sheet pasting method of [6].

[0020] [8] The contact portion spreads planar in the first direction and in a direction non-parallel to the first direction. The decorative sheet pasting method of [6] or [7].

[0021] [9] A pasting device for pasting a decorative sheet on a convexly curved adherend portion of a vehicle body, a holding device for holding a first portion of the decorative sheet, a pressing portion for pressing the decorative sheet against the adherend portion, and is provided with, the pressing portion contacts a second portion away from the first portion of the decorative sheet, and moves from the second portion toward the first portion in a state of contacting the decorative sheet, the holding device moves relative to the adherend portion so that the distance to the contact portion between the pressing portion and the decorative sheet becomes shorter. The decorative sheet pasting device.

[0022] Hereinafter, an embodiment will be described with reference to the drawings. In the drawings, from the viewpoints of illustration and ease of understanding, the scale, dimensional ratio, etc. are exaggerated from those of the actual ones as appropriate. Note that the configurations shown in some of the drawings may be omitted in other drawings.

[0023] Terms such as "sheet", "film", and "plate" are not distinguished from each other only by the difference in name. As an example, the "decorative sheet" may be referred to as a decorative film or a decorative plate.

[0024] Terms such as "parallel" and "orthogonal" for specifying the shape, geometric conditions, and their degrees are not limited to a strict meaning. Terms such as "half" representing the relationship between the magnitude of one numerical value and the magnitude of another numerical value are also not limited to a strict meaning. These terms are interpreted to include a range where similar functions can be expected.

[0025] The directions common among the drawings are indicated by arrows with the same reference numerals in each drawing. In each direction, the tip side of the arrow is the first side. In each direction, the side opposite to the first side, i.e., the base side of the arrow, is the second side. The second side is in the opposite direction to the first side. An arrow pointing from the front to the back of the paper in a direction perpendicular to the plane of the paper is indicated by a symbol with an X inside a circle, as shown in FIG. 2 for example. An arrow pointing from the back to the front of the paper in a direction perpendicular to the plane of the paper is indicated by a symbol with a dot inside a circle, as shown in FIG. 3 for example.

[0026] FIGS. 1 to 8 are diagrams for explaining an embodiment. FIG. 1 is a perspective view of an automobile 1. The illustrated automobile 1 is a passenger car. The automobile 1 is not limited to a passenger car and may be any of a truck, a bus, a taxi, an ambulance, a fire truck, a police vehicle, and a construction work vehicle.

[0027] The automobile 1 shown in FIG. 1 includes a vehicle body 10. The vehicle body 10 forms the outer surface of the automobile 1. The vehicle body 10 may include a plurality of exterior members for forming the outer surface of the automobile 1. The illustrated vehicle body 10 includes, as exterior members, a roof 11, a trunk lid 12, and a bumper 13. The vehicle body 10 may be made of a metal such as aluminum or stainless steel.

[0028] The roof 11 shown in FIG. 1 is curved in a convex shape. The illustrated roof 11 is convex by protruding upward, i.e., on the upper side in the vertical direction. The illustrated roof 11 has a three-dimensional shape. When a certain component of the vehicle body 10 that is curved in a convex shape has a three-dimensional shape, the component has a curved surface that cannot be formed by simply deforming a plane without stretching or shrinking. The illustrated roof 11 has a curved surface 11R that is curved about two or more axes that are non-parallel in the vertical direction and extend non-parallel to each other. The illustrated curved surface 11R is curved about an axis extending in the front-rear direction and an axis extending in the left-right direction.

[0029] Directions such as "front-rear direction", "up-down direction", and "left-right direction", and orientations such as "front", "rear", "up", "down", "right", and "left" are used with respect to the motor vehicle 1 and the components of the motor vehicle 1. The components of the motor vehicle 1 include the vehicle body 10 and exterior members such as the roof 11. The "front-rear direction" is based on the normal traveling direction of the motor vehicle 1 on the traveling surface. "Front" means the direction facing the traveling direction in the front-rear direction. "Rear" means the direction opposite to the direction facing the traveling direction in the front-rear direction. The "up-down direction" means the direction perpendicular to the traveling surface. The "left-right direction" means the direction perpendicular to both the front-rear direction and the up-down direction.

[0030] A decorative sheet 20 is attached to the vehicle body 10 shown in FIG. 1. The decorative sheet 20 displays a design for the application target of the decorative sheet 20. The illustrated decorative sheet 20 is attached to the adherend portion 15. In the illustrated vehicle body 10, the decorative sheet 20 is attached to the roof 11. That is, in the illustrated vehicle body 10, the roof 11 is the adherend portion 15.

[0031] The adherend portion 15 and the decorative sheet 20 attached to the adherend portion 15 may constitute a decorative member 16. The motor vehicle 1 in FIG. 1 includes the decorative member 16. The motor vehicle 1 may include a plurality of decorative members 16.

[0032] The decorative member 16 shown in FIG. 1 has dimensions to some extent in the front-rear direction and the left-right direction. In a state where the decorative member 16 is applied to the motor vehicle 1, the dimension of the decorative member 16 in the front-rear direction may be 0.5 m or more and 4.0 m or less. The dimension of the decorative member 16 in the left-right direction may be 0.5 m or more and 3.0 m or less.

[0033] The decorative sheet 20 shown in FIGS. 1 and 2 is overlaid on the adherend portion 15. In the illustrated example, the lamination direction of the decorative sheet 20 and the adherend portion 15 is the normal direction of the roof 11 on the curved surface 11R. The illustrated decorative sheet 20 is attached to the adherend portion 15 in a state of being stretched in a direction non-parallel to the vertical direction. The decorative sheet 20 has a first surface 20a and a second surface 20b opposite to the first surface 20a. The decorative sheet 20 is attached to the adherend portion 15 from the second surface 20b. The second surface 20b may be referred to as the bonding surface 20f of the decorative sheet 20. The decorative sheet 20 attached to the adherend portion 15 forms the outer surface of the application target (automobile 1 in FIGS. 1 and 2) on the first surface 20a. The first surface 20a is a surface opposite to the bonding surface 20f of the decorative sheet 20.

[0034] The thickness of the decorative sheet 20 in the state of being attached to the adherend portion 15, that is, the length in the lamination direction, may be 0.10 mm or more, or may be 0.40 mm or more. The thickness of the decorative sheet 20 in the state of being attached to the adherend portion 15 may be 0.30 mm or less, or may be 1.0 mm or less.

[0035] In order to stably attach to the adherend portion 15, a lower limit value may be set for the initial peel force on the second surface 20b of the decorative sheet 20. The initial peel force on the second surface 20b of the decorative sheet 20 may be 0.10 N / 25 mm or more, or may be 5.0 N / 25 mm or more. From the viewpoint of facilitating reattachment to the adherend portion 15, an upper limit value may be set for the initial peel force on the second surface 20b of the decorative sheet 20. The initial peel force on the second surface 20b of the decorative sheet 20 may be 5.0 N / 25 mm or less, or may be 20.0 N / 25 mm or less.

[0036] The "initial peel strength" on the second surface 20b of the decorative sheet 20 means the magnitude of the force required to peel off the decorative sheet 20 immediately after it is attached to the adherend 15 from the second surface 20b. The initial peel strength on the second surface 20b of the decorative sheet 20 is measured as follows. First, a sample of the decorative sheet having a length of 100 mm in the longitudinal direction (MD) and a length of 25 mm in the transverse direction (TD) is attached from the second surface to a painted steel sheet having a length of 70 mm. The sample is attached to a portion of the painted steel sheet other than the portion clamped by the chuck described later. The portion of the sample attached to the painted steel sheet has a length of 40 mm in the longitudinal direction. The portion of the sample attached to the painted steel sheet includes one end in the longitudinal direction of the sample. The paint (KINO210TW Clear, manufactured by Kansai Paint Co., Ltd.) is applied to the surface of the painted steel sheet that contacts the sample. When attaching to the painted steel sheet, the sample is pressed with a load of 1 kilogram-force (kgf) by a plate-shaped squeegee.

[0037] Next, within 1 minute after the sample is attached to the painted steel sheet, a 180-degree peel strength test is performed as follows. Clamp one end of the painted steel sheet in one chuck. Fold back the portion of the sample that is not attached to the painted steel sheet by 180 degrees with respect to the portion of the sample attached to the painted steel sheet. Attach a cellophane tape (manufactured by Nichiban Co., Ltd.: CT405AP-24) having a width of 24 mm to the folded-back portion of the sample, and clamp this cellophane tape in the other chuck. Pull the sample in this state at a tensile speed of 200 mm / min under the condition of 25°C, and measure the average stress until the length of the sample peeled off from the painted steel sheet becomes 10 mm to 30 mm. By measuring this average stress in 5 samples, 5 measured values are obtained.

[0038] The initial peeling force on the second surface 20b of the decorative sheet 20 is specified as the average value of three measured values excluding the largest and the smallest among the above-mentioned five measured values. The initial peeling force on the second surface 20b of the decorative sheet 20 is measured in accordance with JIS Z 0237:2009 under conditions other than the above.

[0039] In order to express a glossiness, a lower limit value may be set for the specular glossiness on the first surface 20a of the decorative sheet 20. The 60° specular glossiness on the first surface 20a of the decorative sheet 20 may be 40 or more, 60 or more, or 80 or more. The upper limit value for the specular glossiness on the first surface 20a is not particularly limited. The 60° specular glossiness on the first surface 20a may be 800 or less, or 400 or less.

[0040] The "60° specular glossiness" on the first surface 20a of the decorative sheet 20 means the glossiness measured using the reflected light of the light incident on the first surface 20a at an incident angle of 60°. The 60° specular glossiness is measured using a gloss meter (manufactured by Konica Minolta, Inc., "Rhopoint IQ-S") conforming to JIS Z 8741:1997. The 60° specular glossiness on the first surface 20a of the decorative sheet 20 is calculated as the average value of five measured values obtained at five different locations on the first surface 20a using the above-mentioned gloss meter. Other conditions regarding the measurement of the 60° specular glossiness conform to JIS Z 8741:1997.

[0041] The decorative sheet 20 shown in FIGS. 1 and 2 includes a bonding layer 24, a base material layer 21, a design layer 22, and a surface layer 23 in this order from the second surface 20b to the first surface 20a. In the decorative sheet 20 shown in FIG. 2, the surface layer 23 forms the first surface 20a of the decorative sheet 20. The bonding layer 24 forms the second surface 20b of the decorative sheet 20. The bonding layer 24 forms the bonding surface 20f of the decorative sheet 20.

[0042] The base material layer 21 shown in Fig. 2 is located between the bonding layer 24 and the design layer 22. The base material layer 21 supports the layers other than the base material layer 21 of the decorative sheet 20. The base material layer 21 may be a film. The base material layer 21 may contain a thermoplastic resin. The thermoplastic resin contained in the base material layer 21 may contain one or more of acrylic, PET (polyethylene terephthalate), polyolefin resins such as polypropylene and polyethylene, polycarbonate, PVC (polyvinyl chloride), styrene, vinylidene chloride, thermoplastic urethane, and fluororesin.

[0043] The design layer 22 shown in Fig. 2 is located between the base material layer 21 and the surface layer 23. The design layer 22 forms the design displayed by the decorative sheet 20. The design layer 22 may form one or more of a figure, a pattern, a color, a mark, and a character as the design. The design layer 22 may include a binder resin part and a coloring material held by the binder resin part. The binder resin part may contain a thermoplastic resin. As the thermoplastic resin contained in the design layer 22, one or more of the thermoplastic resins exemplified in the above description regarding the base material layer 21 may be used. The coloring material may be a dye, a pigment, or a combination of a dye and a pigment. The design layer 22 may be formed by printing. The design layer 22 may be formed by transfer.

[0044] The surface layer 23 shown in Fig. 2 has the functions required for the outer surface of the decorative sheet 20. As an example, the surface layer 23 may be a hard coat layer having scratch resistance. The surface layer 23 may be an antifouling layer having an antifouling function.

[0045] The bonding layer 24 shown in Fig. 2 is located between the adherend portion 15 and the base material layer 21. The bonding layer 24 improves the adhesion of the decorative sheet 20 to the adherend portion 15. The bonding layer 24 may contain an adhesive or an adhesive agent. The adhesive contained in the bonding layer 24 may contain one or more of an acrylic adhesive, a rubber adhesive, a urethane adhesive, and a silicone adhesive. The adhesive agent contained in the bonding layer 24 may contain one or more of an acrylic adhesive agent, a rubber adhesive agent, a urethane adhesive agent, and a silicone adhesive agent.

[0046] A method of attaching the decorative sheet 20 shown in FIGS. 1 and 2 to the attachment portion 15 of the vehicle body 10 will be described with reference to FIGS. 3 to 8. For attaching the decorative sheet 20 shown in FIGS. 1 and 2 to the attachment portion 15, an attaching device 30 shown in FIGS. 3 to 5 is used. As shown in FIG. 3, when the vehicle body 10 is observed from above, the attaching device 30 is arranged so as to surround the attachment portion 15 from the front-rear direction and the left-right direction. In FIG. 3, the attachment portion 15 is surrounded by the attaching device 30 from a direction non-parallel to the first direction D1. The attaching device 30 attaches the decorative sheet 20 to the attachment portion 15 in an attachment region 30R surrounding the attachment portion 15.

[0047] The decorative sheet 20 may be attached to the attachment portion 15 under atmospheric pressure. The attaching device 30 shown in FIG. 3 may be installed in an atmospheric pressure environment.

[0048] The attaching device 30 shown in FIGS. 3 to 5 includes a plurality of holding devices 31 for holding the decorative sheet 20 and a plurality of support devices 32 for supporting the decorative sheet 20. The plurality of holding devices 31 are arranged on the right side and the left side with respect to the vehicle body 10. The plurality of support devices 32 are arranged on the front side and the rear side with respect to the vehicle body 10.

[0049] FIG. 3 shows a plurality of holding devices 31 arranged at intervals in the X direction DX. Each of the illustrated holding devices 31 faces another holding device 31 via the attachment portion 15 in the Y direction DY orthogonal to the X direction DX. The attachment portion 15 is located between the holding devices 31 in the Y direction DY. In the illustrated attaching device 30, an attachment region 30R is formed between the holding devices 31 adjacent to each other in the Y direction DY. In the illustrated attaching device 30, the X direction DX is parallel to the front-rear direction of the vehicle body 10. The Y direction DY is parallel to the left-right direction of the vehicle body 10.

[0050] The illustrated pasting device 30 has a frame 35 for holding a holding device 31 and a support device 32. The holding device 31 and the support device 32 are attached to the frame 35. The frame 35 extends in a Z direction DZ that is orthogonal to both an X direction DX and a Y direction DY. In the illustrated pasting device 30, the Z direction DZ is parallel to the vertical direction of the vehicle body 10. The frame 35 may be made of a metal such as aluminum.

[0051] The holding device 31 shown in FIGS. 3 to 5 is a clamp 33. The illustrated clamp 33 sandwiches the decorative sheet 20 from a first side and a second side in the Z direction DZ. The illustrated holding device 31 (clamp 33) holds the decorative sheet 20 by sandwiching the decorative sheet 20.

[0052] The holding device 31 shown in FIGS. 3 to 5 can move in the Z direction DZ with respect to the frame 35 while holding the decorative sheet 20. The illustrated clamp 33 can move in the Z direction DZ with respect to the frame 35 while sandwiching the decorative sheet 20. The holding device 31 can move in the vertical direction with respect to the vehicle body 10 while holding the decorative sheet 20.

[0053] The holding device 31 may be movable in a direction non-parallel to the Z direction DZ with respect to the frame 35 while holding the decorative sheet 20. The holding device 31 may be movable in a direction non-parallel to the vertical direction with respect to the vehicle body 10 while holding the decorative sheet 20. The holding device 31 shown in FIGS. 3 to 5 is movable in the X direction DX with respect to the frame 35. The illustrated holding device 31 is also movable in the Y direction DY with respect to the frame 35. Further, the clamp 33 may be rotatable with respect to the frame 35, the vehicle body 10, and the adherend portion 15 while sandwiching the decorative sheet 20. The illustrated holding device 31 is rotatable with respect to the frame 35 about an axis AS extending in the Y direction DY. The plurality of illustrated holding devices 31 are rotating about the axis AS from the state shown in FIG. 4 to the state shown in FIG. 5 in the state shown in FIG. 5.

[0054] Figure 3 shows two support devices 32 spaced apart from each other in the X direction DX. In the illustrated pasting device 30, a pasting area 30R for pasting the decorative sheet 20 is formed between the two support devices 32. The illustrated support device 32 is a roller 34. The illustrated roller 34 has an axis extending parallel to the Y direction DY. The roller 34 supports the decorative sheet 20 by contacting the decorative sheet 20 from an outer peripheral surface extending in the circumferential direction centered on the axis.

[0055] The support device 32 (roller 34) shown in FIGS. 3 to 5 can move in the Z direction DZ with respect to the frame 35 while supporting the decorative sheet 20. The support device 32 can move in the vertical direction with respect to the vehicle body 10 while supporting the decorative sheet 20.

[0056] The holding device 31 and the support device 32 may be movable with respect to the frame 35 by a driving device (not shown). The driving device may include a motor. The driving device may be controlled by an external control device (not shown). The control device may include a computer. The movement of the holding device 31 and the support device 32 with respect to the frame 35, the vehicle body 10, and the adherend portion 15 may be controlled by the control device.

[0057] Attach the decorative sheet 20 to the pasting device 30 having the above configuration. Place the decorative sheet 20 in the pasting area 30R. The decorative sheet 20 is arranged above the vehicle body 10. The long decorative sheet 20 may be pulled out from the state of being wound around the core and placed in the pasting area 30R. Alternatively, a single-sheet decorative sheet 20 may be placed in the pasting area 30R. The decorative sheet 20 placed in the pasting area 30R has a longitudinal direction DL1 in a direction parallel to the X direction DX. The decorative sheet 20 placed in the pasting area 30R has a width direction DW1 in a direction parallel to the Y direction DY.

[0058] The decorative sheet 20 disposed in the pasting area 30R is held by the holding device 31. In the pasting device 30 shown in FIGS. 3 to 5, the decorative sheet 20 is sandwiched by a plurality of clamps 33 from both sides in the Z direction DZ. The decorative sheet 20 disposed in the pasting area 30R is supported by the support device 32. In the illustrated pasting device 30, the decorative sheet 20 is supported by a roller 34 from the second side in the Z direction DZ.

[0059] The decorative sheet 20 shown in FIGS. 3 to 5, in a state of being attached to the pasting device 30, has a plurality of first portions 201 held by the holding device 31 and a plurality of support portions supported by the support device 32. The first portion 201 may be referred to as a holding portion. The first portion 201 is located at both ends in the width direction DW1 of the decorative sheet 20. The first portion 201 extends in the longitudinal direction DL1 of the decorative sheet 20. The support portions are located at both ends in the longitudinal direction DL1 of the decorative sheet 20 located in the pasting area 30R. The support portions extend in the width direction DW1 of the decorative sheet 20.

[0060] As described above, the decorative sheet 20 attached to the pasting device 30 is pulled in the width direction DW1 by the holding device 31. The holding device 31 may pull the decorative sheet 20 in the width direction DW1 by moving in the Y direction DY with respect to the frame 35 while holding the decorative sheet 20.

[0061] The pasting device 30 may include weights 36 for pulling the decorative sheet 20 as shown in FIGS. 3 to 5. The illustrated pasting device 30 includes two weights 36. The weights 36 are respectively attached to the ends in the longitudinal direction DL1 of the decorative sheet 20. The illustrated decorative sheet 20 is pulled in the longitudinal direction DL1 in the pasting area 30R by the two weights 36.

[0062] From the state of being attached to the pasting device 30, the decorative sheet 20 approaches the adherend portion 15. When the decorative sheet 20 is brought closer to the adherend portion 15, in the pasting device 30 shown in FIGS. 3 to 5, the holding device 31 and the support device 32 move to the second side in the Z direction DZ with respect to the frame 35. The holding device 31 moves with respect to the frame 35 while holding the decorative sheet 20. The support device 32 moves with respect to the frame 35 while supporting the decorative sheet 20. FIG. 5 shows the pasting device 30 with the decorative sheet 20 closer to the adherend portion 15 than in FIG. 4.

[0063] The decorative sheet 20 contacts the adherend portion 15. The decorative sheet 20 contacts the adherend portion 15 from the bonding surface 20f. The decorative sheet 20 shown in FIGS. 3 to 5 contacts the adherend portion 15 at the second portion 202 away from the first portion 201. The illustrated decorative sheet 20 contacts the adherend portion 15 from the second surface 20b formed by the bonding layer 24. The portion of the decorative sheet 20 that contacts the adherend portion 15 bonds to the adherend portion 15. The portion of the decorative sheet 20 that contacts the adherend portion 15 is restricted from moving with respect to the adherend portion 15.

[0064] The decorative sheet 20 shown in FIG. 4 may contact the adherend portion 15 as the holding device 31 and the support device 32 move with respect to the frame 35. The decorative sheet 20 may contact the adherend portion 15 as a result of being pressed toward the adherend portion 15 by the pressing portion 40 described later.

[0065] The second portion 202 shown in FIGS. 3 to 5 is farther from the first portion 201 in the width direction DW1 of the decorative sheet 20 in the pasting region 30R. The illustrated second portion 202 is a portion facing the central portion in the left - right direction of the vehicle body 10. The second portion 202 may be a portion facing the most protruding portion of the adherend portion 15. The second portion 202 may be a portion located at the uppermost position of the adherend portion 15.

[0066] Next, as the contact step, the pressing portion 40 contacts the second portion 202 of the decorative sheet 20. The pressing portion 40 contacts the decorative sheet 20 from the surface opposite to the bonding surface 20f. The pressing portion 40 presses the decorative sheet 20 against the adherend portion 15. The decorative sheet 20 contacts the adherend portion 15 from the bonding surface 20f at the portion pressed by the pressing portion 40.

[0067] FIG. 6 shows an example of the pressing portion 40. The illustrated pressing portion 40 is a linear member having a longitudinal direction DL2. FIG. 6 is a view of the pressing portion 40 observed from one end in the longitudinal direction DL2. The illustrated pressing portion 40 contacts the decorative sheet 20 at the curved contact surface 40R.

[0068] The longitudinal direction DL2 of the pressing portion 40 shown in FIG. 3 is parallel to the longitudinal direction DL1 of the decorative sheet 20. The longitudinal direction DL1 of the decorative sheet 20 may be referred to as the first longitudinal direction DL1. The longitudinal direction DL2 of the pressing portion 40 may be referred to as the second longitudinal direction DL2.

[0069] The contact portion CP between the pressing portion 40 and the decorative sheet 20 extends in the first direction D1. The first direction D1 may be the longitudinal direction DL3 of the contact portion CP. The contact portion CP may also extend in a direction non-parallel to the first direction D1. The contact portion CP may extend in the first direction D1 and in a direction non-parallel to the first direction D1 by the pressing portion 40 making surface contact with the decorative sheet 20. The contact portion CP shown in FIG. 7 spreads planar in the first direction D1 and in the second direction D2 orthogonal to the first direction D1. The second direction D2 may be a direction orthogonal to the longitudinal direction DL3 of the contact portion CP as shown in FIG. 7.

[0070] Note that the contact portion CP is the portion where the pressing portion 40 presses the decorative sheet 20 against the adherend portion 15 with a pressure of 0.03 MPa or more. The pressure in the contact portion CP may be 0.19 MPa or less, 0.15 MPa or less, 0.09 MPa or less, or 0.07 MPa or less.

[0071] The pressure for pressing the decorative sheet 20 against the adherend portion 15 is measured by a pressure measurement system "I-SCAN" manufactured by Nitto Co., Ltd. The pressure is measured by placing a sheet-like sensor electrically connected to the pressure measurement system on the decorative sheet 20 and pressing the pressing portion 40 against this sensor. The sheet-like sensor has a thickness of 0.01 mm. The sheet-like sensor includes a measurement portion. The measurement portion has dimensions of 112 mm square.

[0072] FIG. 7 shows two contact portions CP including overlapping portions. Both of the two contact portions CP extend in the first direction D1. The contact portion CP may have an elliptical shape as shown in FIG. 7. The first direction D1 shown in FIG. 7 is a direction parallel to the major axis of the illustrated ellipse. The second direction D2 shown in FIG. 7 is a direction parallel to the minor axis of the illustrated ellipse. Of the two illustrated contact portions CP, one contact portion CPX has an overall length LX as the maximum length in the first direction D1. Of the two illustrated contact portions CP, the other contact portion CPY has an overall length LY as the maximum length in the first direction D1.

[0073] The "longitudinal direction DL3 of the contact portion CP" is specified as follows using the above-described pressure measurement system "I-SCAN". In the pressure distribution of the contact portion CP measured by the above-described method, the point with the largest measured value is specified. The longitudinal direction DL3 of the contact portion CP is the direction having the largest dimension when the dimensions of the contact portion CP in various measurement directions passing through the point with the largest measured value are measured. The various measurement directions are directions orthogonal to the normal direction of the measurement surface.

[0074] In the contact portion CP spreading in a planar shape, the dimension in the first direction D1 may be 50 times or less, 20 times or less, or 10 times or less the dimension in the second direction D2. In the contact portion CP spreading in a planar shape, the dimension in the first direction D1 may be 1.0 times or more the dimension in the second direction D2.

[0075] The pressure with which the pressing portion 40 presses the decorative sheet 20 may vary according to the position of the planar contact portion CP. FIG. 7 shows the distribution of the pressure [Pa] in the first direction D1 of the contact portion CP having an elliptical shape. The illustrated pressing portion 40 presses the decorative sheet 20 with a pressure P1 at the central portion in the first direction D1 of the contact portion CP. The pressure P1 is the maximum value of the pressure with which the pressing portion 40 presses the decorative sheet 20. In the illustrated contact portion CP, the pressure with which the pressing portion 40 presses the decorative sheet 20 decreases as it moves away from the central portion in the first direction D1 of the pressing portion 40. The pressure from the pressing portion 40 in the contact portion CP is lower than the pressure P2, which is half the value of the pressure P1, at the end in the first direction D1.

[0076] As shown in FIG. 6, the pressing portion 40 may have a porous structure. The pressing portion 40 may include one or more of urethane foam and soft vinyl chloride (PVC) foam as materials having such a structure. As shown in FIG. 6, the pressing portion 40 may press the decorative sheet 20 against the adherend portion 15 while being held in the hand H of the operator. Different from the illustrated example, the pressing portion 40 attached to the tip of the robot arm may press the decorative sheet 20 against the adherend portion 15.

[0077] Next, the pressing portion 40 in contact with the decorative sheet 20 is moved from the second portion 202 toward the first portion 201. FIG. 3 shows the pressing portion 40 located in the second portion 202. The pressing portion 40 moves on the decorative sheet 20 from the state shown in FIG. 3 toward the first portion 201. In the region where the pressing portion 40 has moved, the decorative sheet 20 is attached to the adherend portion 15.

[0078] In the pasting device 30 shown in FIG. 3, as a first pressing step, the first region 20X of the decorative sheet 20 is pressed against the adherend 15 by the movement of the pressing portion 40. In the illustrated pasting device 30, after the first pressing step, as a second pressing step, the second region 20Y of the decorative sheet 20 is pressed against the adherend 15 by the movement of the pressing portion 40. The first region 20X and the second region 20Y are adjacent to each other in the adjacent direction DA. The illustrated second region 20Y is adjacent to the first region 20X in the longitudinal direction DL1 of the decorative sheet 20. That is, in the illustrated pasting device 30, the adjacent direction DA in which the first region 20X and the second region 20Y are adjacent is a direction parallel to the longitudinal direction DL1 of the decorative sheet 20.

[0079] In FIG. 3, the first region 20X is a region extending in the width direction DW1 of the decorative sheet 20. The first region 20X shown in FIG. 3 has a first edge 20XA and a second edge 20XB that are separated from each other in the longitudinal direction DL1 of the decorative sheet 20. The first region 20X has a third edge 20XC and a fourth edge 20XD that are separated from each other in the width direction DW1 of the decorative sheet 20. The first edge 20XA and the second edge 20XB extend in the width direction DW1 of the decorative sheet 20. The third edge 20XC and the fourth edge 20XD extend in the longitudinal direction DL1 of the decorative sheet 20.

[0080] In the decorative sheet 20 shown in FIG. 3, the third edge 20XC is disposed on the second portion 202. The illustrated fourth edge 20XD is closer to the first portion 201 than the third edge 20XC. The pressing portion 40 moves on the first region 20X from the third edge 20XC toward the fourth edge 20XD. When the pressing portion 40 reaches the fourth edge 20XD while moving on the first region 20X, it is separated from the decorative sheet 20. When the pressing portion 40 reaches the fourth edge 20XD, the pasting of the decorative sheet 20 in the first region 20X to the adherend 15 is completed.

[0081] When pressing the first area 20X against the adhering part 15, the pressing part 40 may be separated from the decorative sheet 20 between the third edge 20XC and the fourth edge 20XD. The pressing part 40 may be separated from the decorative sheet 20 during the first pressing process of pressing the first area 20X against the adhering part 15. The first area 20X may be attached to the adhering part 15 by repeating a single pressing operation, that is, the operation from when the pressing part 40 contacts the decorative sheet 20 until it is separated, a plurality of times. The first area 20X may be attached to the adhering part 15 by a single pressing operation without separating the pressing part 40 from the decorative sheet 20.

[0082] Incidentally, the first area 20X shown in FIG. 3 is pressed against the adhering part 15 with a relatively small pressure at both ends in the longitudinal direction DL2 of the pressing part 40. FIG. 7 shows a first contact portion CPX as a contact portion CP between the pressing part 40 and the decorative sheet 20 when pressing the first area 20X against the adhering part 15. As the first contact portion CPX moves on the decorative sheet 20, the first area 20X is pressed against the adhering part 15.

[0083] FIG. 7 also shows the pressure from the pressing part 40 at the first contact portion CPX. The pressure is distributed within a certain range in the longitudinal direction DL2 of the pressing part 40. As shown in FIG. 7, the pressure from the pressing part 40 at the first contact portion CPX decreases at both ends in the first direction D1. In other words, the first contact portion CPX has a low-pressure portion RDX where the pressure from the pressing part 40 is relatively small at both ends in the first direction D1. In particular, in the illustrated first contact portion CPX, the pressure in the low-pressure portion RDX has decreased to a pressure P2 that is equal to or less than half of the maximum pressure P1 from the pressing part 40.

[0084] The first contact portion CPX shown in FIG. 7 has a full width at half maximum LXF with respect to the pressure from the pressing portion 40 in a range where the pressure from the pressing portion 40 is P2 or more. The full width at half maximum LXF is a dimension in the first direction D1 of a part of the first contact portion CPX. The illustrated full width at half maximum LXF is a value obtained by subtracting the lengths in the first direction D1 of the two low-pressure portions RDX from the length LX in the first direction D1 of the first contact portion CPX. The illustrated full width at half maximum LXF of the first contact portion CPX is 20% or more of the length LX in the first direction D1 of the first contact portion CPX. The full width at half maximum LXF of the first contact portion CPX may be 50% or more of the length LX in the first direction D1 of the first contact portion CPX as shown in FIG. 7. The full width at half maximum LXF of the first contact portion CPX may be even larger than that shown in FIG. 7. For example, the full width at half maximum LXF of the first contact portion CPX may be 80% or more of the length LX in the first direction D1 of the first contact portion CPX.

[0085] In the first region 20X pressed by the pressing portion 40 in the low-pressure portion RDX, a low-pressure region where the pressure applied from the pressing portion 40 is half or less of the maximum value P1 is generated. In the first region 20X shown in FIG. 3, the low-pressure region is located at the end in the longitudinal direction DL1 of the first region 20X. In the illustrated first region 20X, the low-pressure region is a region including the first edge 20XA or the second edge 20XB.

[0086] In the pasting device 30 shown in FIG. 3, next to the first region 20X, as a second pressing step, a second region 20Y adjacent to the first region 20X of the decorative sheet 20 in the adjacent direction DA is pressed against the adherend 15 by the movement of the pressing portion 40. The second region 20Y is a region that at least partially overlaps the first region 20X.

[0087] The second region 20Y shown in FIG. 3 is a region extending in the width direction DW1 of the decorative sheet 20. The second region 20Y shown in FIG. 3 has a first edge 20YA and a second edge 20YB that are separated from each other in the longitudinal direction DL1 of the decorative sheet 20. The second region 20Y has a third edge 20YC and a fourth edge 20YD that are separated from each other in the width direction DW1 of the decorative sheet 20. The first edge 20YA and the second edge 20YB extend in the width direction DW1 of the decorative sheet 20. The third edge 20YC and the fourth edge 20YD extend in the longitudinal direction DL1 of the decorative sheet 20.

[0088] In the decorative sheet 20 shown in FIG. 3, the third edge 20YC is disposed on the second portion 202. The illustrated fourth edge 20YD is closer to the first portion 201 than the third edge 20YC. The pressing portion 40 moves on the second region 20Y from the third edge 20YC toward the fourth edge 20YD. The pressing portion 40 moving on the second region 20Y is separated from the decorative sheet 20 when it reaches the fourth edge 20YD. When the pressing portion 40 reaches the fourth edge 20XD, the attachment of the decorative sheet 20 to the attachment portion 15 in the second region 20Y is completed. The pressing portion 40 may be separated from the decorative sheet 20 between the third edge 20YC and the fourth edge 20YD, similar to the first region 20X. The decorative sheet 20 may be attached to the attachment portion 15 in the second region 20Y by a plurality of pressing operations, similar to the first region 20X.

[0089] The second region 20Y shown in FIG. 3 is pressed against the attachment portion 15 with a relatively small pressure at both ends in the longitudinal direction DL2 of the pressing portion 40, similar to the first region 20X. FIG. 7 shows a second contact portion CPY as a contact portion CP between the pressing portion 40 and the decorative sheet 20 when pressing the second region 20Y against the attachment portion 15. By the second contact portion CPY moving on the decorative sheet 20, the second region 20Y is pressed against the attachment portion 15. Similar to the first contact portion CPX, FIG. 7 also shows the pressure from the pressing portion 40 at the second contact portion CPY.

[0090] In the second contact portion CPY shown in FIG. 7, the pressure from the pressing portion 40 decreases at both ends in the first direction D1. In other words, the second contact portion CPY has a low-pressure portion RDY where the pressure from the pressing portion 40 is relatively small at both ends in the first direction D1. In particular, in the illustrated second contact portion CPY, the pressure in the low-pressure portion RDY has decreased to a pressure P2 that is less than or equal to half of the maximum value P1 of the pressure from the pressing portion 40.

[0091] The second contact portion CPY shown in FIG. 7 has a full width at half maximum LYF with respect to pressure, as a range where the pressure from the pressing portion 40 is P2 or more. The full width at half maximum LYF is a dimension of the second contact portion CPY in the first direction D1. The illustrated full width at half maximum LYF is a value obtained by subtracting the lengths in the first direction D1 of the two low-pressure portions RDY from the length LY of the second contact portion CPY in the first direction D1. The illustrated full width at half maximum LYF of the second contact portion CPY is 20% or more of the length LY of the second contact portion CPY in the first direction D1. The full width at half maximum LYF of the second contact portion CPY may be 50% or more, or 80% or more, of the length LY of the second contact portion CPY in the first direction D1.

[0092] In the second region 20Y pressed by the pressing portion 40 in the low-pressure portion RDY, a low-pressure region where the pressure applied from the pressing portion 40 is less than or equal to half of the maximum value P1 occurs. In the second region 20Y shown in FIG. 3, the low-pressure region is located at the end in the longitudinal direction DL1 of the second region 20Y. In the illustrated second region 20Y, the low-pressure region is a region including the first edge 20YA or the second edge 20YB.

[0093] The first region 20X and the second region 20Y shown in FIG. 3 include an overlapping region 20Z that overlaps each other, as shown by using hatching in the figure. The first region 20X and the second region 20Y overlap each other at one of the ends in the adjacent direction DA. The illustrated overlapping region 20Z is located at the end in the adjacent direction DA of the first region 20X, including the second edge 20XB. The illustrated overlapping region 20Z is located at the end in the adjacent direction DA of the second region 20Y, including the first edge 20YA.

[0094] The overlapping region 20Z shown in FIG. 3 extends in the width direction DW1 of the decorative sheet 20. In the overlapping region 20Z, the decorative sheet 20 is pressed against the adherend 15 by the operation of the pressing portion 40 that presses the first region 20X against the adherend 15 and the operation of the pressing portion 40 that presses the second region 20Y against the adherend 15. That is, in the overlapping region 20Z, the decorative sheet 20 is pressed against the adherend 15 at least twice by the moving pressing portion 40.

[0095] In FIG. 7, an overlapping portion CPZ is shown as a portion where the first contact portion CPX and the second contact portion CPY overlap each other. By moving the overlapping portion CPZ on the decorative sheet 20, the overlapping region 20Z is pressed against the adherend 15. One first low-pressure portion RDX of the first contact portion CPX is located in the overlapping portion CPZ. One second low-pressure portion RDY of the second contact portion CPY is located in the overlapping portion CPZ. The first contact portion CPX has a portion that overlaps with the second low-pressure portion RDY located in the overlapping portion CPZ. The second contact portion CPY has a portion that overlaps with the first low-pressure portion RDX located in the overlapping portion CPZ.

[0096] In the overlapping portion CPZ shown in FIG. 7, the pressure from the pressing portion 40 on the portion overlapping with the first low-pressure portion RDX of the second contact portion CPY is greater than the pressure from the pressing portion 40 on the first low-pressure portion RDX. In other words, the portion pressed against the adherend 15 by the first low-pressure portion RDX of the first contact portion CPX in the first pressing step is pressed against the adherend 15 with a greater pressure in the second pressing step.

[0097] By repeating the above-described operations, the decorative sheet 20 is attached to the adherend 15. In other words, as a result of repeating the operation of pressing the region adjacent to the already attached region of the decorative sheet 20 against the adherend 15, the decorative sheet 20 is attached to the adherend 15.

[0098] Incidentally, as a method of attaching a decorative sheet to a convexly curved attachment portion of a vehicle body, JP2020-124852A proposes a method using a decompression device that decompresses the attachment portion and the space disposed on the attachment portion. A decorative member is constituted by the decorative sheet and the attachment portion to which the decorative sheet is attached. The decompression device can cause the decorative sheet to adhere closely to the attachment portion. The decompression device can suppress the generation of air pockets between the decorative sheet and the attachment portion. However, when attaching a decorative sheet to a large attachment portion including an exterior member of a vehicle, it takes time to decompress the space between the attachment portion and the decorative sheet. In the conventional attachment method using a decompression device, the time from when the decorative sheet is disposed on the attachment portion until it is attached to the attachment portion can increase. Also, the attachment cost of the decorative sheet can increase due to the decompression operation.

[0099] From the viewpoint of suppressing an increase in attachment time and attachment cost, the decorative sheet is attached to the attachment portion using a pressing portion. The pressing portion presses the decorative sheet disposed on the attachment portion against the attachment portion. The pressing portion moves on the decorative sheet in a direction non-parallel to the direction in which the attachment portion protrudes. The pressing portion moves toward the edge of the portion of the decorative sheet disposed on the attachment portion. As the pressing portion moves on the decorative sheet, the air between the decorative sheet and the attachment portion moves toward the above-described edge together with the pressing portion and is discharged from between the decorative sheet and the attachment portion. Therefore, by using the pressing portion, the generation of air pockets in the attached decorative sheet can be suppressed, and the decorative sheet can be made to adhere closely to the attachment portion. Also, the decorative sheet is attached to the attachment portion without using a decompression device, and an increase in attachment time and attachment cost is suppressed.

[0100] From the viewpoint of suppressing the decorative sheet from being attached in a state including wrinkles to the convexly curved attachment portion, it is preferable that the decorative sheet be attached in a stretched state. The decorative sheet before being attached to the attachment portion may be disposed in a stretched state on the attachment portion. The stretched decorative sheet may be pressed against the attachment portion by the pressing portion.

[0101] When the decorated sheet in a stretched state was brought into contact with the protruding central portion of the adherend and attached to the adherend using the pressing portion, linear first streaks occurred on the decorated sheet. The first streaks extended in a direction orthogonal to the moving direction of the pressing portion that had moved on the decorated sheet. In the decorated sheet, the first streaks occurred at the terminal position of the pressing portion in a single pressing operation. In other words, the first streaks occurred at the position where the pressing portion was separated from the decorated sheet. The observation of the first streaks deteriorated the designability of the decorated sheet and the decorative member.

[0102] The cause of the first streaks is presumed as follows based on the occurrence position and appearance. However, the present disclosure is not restricted by the following presumption.

[0103] The decorated sheet includes an adhered portion attached to the adherend, a held portion held by a holding device, and an intermediate portion located between the adhered portion and the held portion. The intermediate portion connects the adhered portion and the held portion. In the adhered portion, the stretched decorated sheet is restricted from moving with respect to the adherend and thus does not receive the tension from the holding device. In the held portion, the stretched decorated sheet also does not receive the tension from the holding device. In the intermediate portion, the stretched decorated sheet receives the tension from the holding device.

[0104] As the decorated sheet is attached to the adherend by the movement of the pressing portion, the intermediate portion shrinks. On the other hand, the distance between the boundary between the adhered portion and the intermediate portion and the boundary between the intermediate portion and the held portion can increase. As a result, as the decorated sheet is attached to the adherend, the amount of elongation in the intermediate portion of the decorated sheet increases.

[0105] In a decorative sheet to be attached to a convexly curved adhering portion, at the boundary between the adhering portion and the intermediate portion, a difference in elongation amount occurs between the bonding surface of the decorative sheet and the surface opposite to the bonding surface. The difference in elongation amount increases as the elongation amount in the intermediate portion increases. At the terminal position of the pressing portion in a single pressing operation, such a state is maintained for a short time. At the terminal position of the pressing portion in a single pressing operation, the bonding layer is deformed due to the difference in elongation amount between the bonding surface and the surface opposite to the bonding surface. As a result of these, it is presumed that streaks are generated at the terminal position of the pressing portion in a single pressing operation.

[0106] Further, when the decorative sheet is attached to the adherend by the above-described method, a second streak extending in the moving direction of the pressing portion also occurred in the attached decorative sheet. In the decorative sheet, the second streak occurred at the boundary between the region pressed against the adhering portion by the pressing portion and the region not pressed against the adhering portion. The second streak was particularly prominently observed when a pressing portion that makes line contact with the decorative sheet was used. The observation of the second streak degraded the designability of the decorative sheet and the decorative member.

[0107] As a result of investigations by the inventors of the present case, it was presumed that the bonding layer was compressed and deformed by the pressing portion in the decorative sheet. In the decorative sheet, it was presumed that the boundary between the compressed and deformed portion and the non-compressed and deformed portion was observed as a linear streak (second streak). It was presumed that as the pressure from the pressing portion increased, the height difference at the above-described boundary of the decorative sheet increased and the second streak was prominently observed. However, the present disclosure is not bound by the above presumptions regarding the generation mechanism of the second streak.

[0108] In the method of attaching the decorative sheet 20 shown in FIGS. 3 to 5, the holding device 31 moves with respect to the adhering portion 15 so that the distance to the contact portion CP between the decorative sheet 20 and the pressing portion 40 becomes shorter in the pressing step. In the decorative sheet 20 attached by the illustrated method, as described below, it is possible to suppress the prominent observation of the above-described first streak at the terminal position of the pressing portion 40 in a single pressing operation.

[0109] FIG. 8 shows, as an example of the holding device 31 that moves relative to the adherend portion 15 so that the distance to the contact portion CP is shortened, a first holding device 31A and a second holding device 31B. When the first pressing portion 40A shown in FIG. 8 moves from the first position SA1 to the second position SA2, the first holding device 31A moves from the first position CA1 to the second position CA2. When the second pressing portion 40B shown in FIG. 8 moves from the first position SB1 to the second position SB2, the second holding device 31B moves from the first position CB1 to the second position CB2.

[0110] The first holding device 31A shown in FIG. 8 is moving relative to the adherend portion 15 so that the distance to the contact portion CP between the decoration sheet 20 and the first pressing portion 40A moving on the decoration sheet 20 is shortened. The first holding device 31A is moving in a first direction D1 relative to the adherend portion 15 toward the second position CA2 from the first position CA1. The illustrated first holding device 31A is moving in the second side in the first direction D1, that is, in the direction opposite to the direction in which the adherend portion 15 protrudes in the first direction D1. The first holding device 31A is moving downward relative to the vehicle body 10.

[0111] In FIG. 8, when the first pressing portion 40A moves to the second position SA2, the amount of elongation in the middle portion of the decoration sheet 20 is reduced by the movement of the first holding device 31A to the second position CA2. In FIG. 8, the middle portion when the first holding device 31A stays at the first position CA1 is shown by a broken line. The amount of elongation of the middle portion when the first holding device 31A moves to the second position CA2 is smaller than the amount of elongation of the middle portion shown by the broken line. By reducing the amount of elongation in the middle portion, the decoration sheet can suppress an increase in the tension per unit length in the middle portion. Therefore, when the first pressing portion 40A is released at the second position SA2, the generation of streaks at the contact portion CP can be suppressed by the first holding device 31A that has moved to the second position CA2.

[0112] 8 is moving relative to the attachment portion 15 so as to shorten the distance to the contact point CP between the decorative sheet 20 and the second pressing portion 40B moving on the decorative sheet 20. The second attachment portion 31B is moving in a third direction D3 perpendicular to the first direction D1 from the first position CB1 toward the second position CB2 relative to the attachment portion 15. The illustrated second attachment portion 31B is moving to the first side in the third direction D3.

[0113] In FIG. 8, when the second pressing portion 40B moves to the second position SB2, the amount of elongation in the middle portion of the decorative sheet 20 is reduced by the movement of the second holding device 31B to the second position CB2. In FIG. 8, the middle portion when the second holding device 31B remains at the first position CB1 is indicated by a dashed line. The amount of elongation in the middle portion when the second holding device 31B moves to the second position CB2 is smaller than the amount of elongation in the middle portion indicated by the dashed line. By reducing the amount of elongation in the middle portion, the decorative sheet can suppress an increase in the tension applied per unit length in the middle portion. Therefore, when the second pressing portion 40B is released at the second position SB2, the second holding device 31B, which has moved to the second position CB2, can suppress the occurrence of streaks at the contact portion CP.

[0114] 3 to 5, the decorative sheet 20 is attached to the attachment portion 15 of the vehicle body 10 by a pressing portion 40. In a pressing step (first pressing step) of attaching the first region 20X of the decorative sheet 20 to the attachment portion 15, the pressing portion 40 contacts the decorative sheet 20 at a first contact portion CPX extending in the first direction D1. The pressure from the pressing portion 40 at the first contact portion CPX is reduced to less than half of the maximum value P1 at a first low-pressure portion RDX located at the end of the first direction D1. The full width at half maximum of the pressure from the pressing portion 40 at the first contact portion CPX is 20% or more of the entire length of the first contact portion CPX.

[0115] When the first region 20X of the decorative sheet 20 is attached to the attachment portion 15, the pressing portion 40 presses the decorative sheet 20 against the attachment portion 15 with a relatively small pressure at the first low-pressure portion RDX. By reducing the pressure applied to the attachment portion 15, compressive deformation of the bonding layer 24 is suppressed in the portion of the first region 20X pressed by the first low-pressure portion RDX, i.e., the end portion in the longitudinal direction DL1 of the decorative sheet 20. Therefore, according to the method of attaching the decorative sheet 20 shown in Figs. 3 to 5, it is possible to prevent the second streak from being conspicuously observed.

[0116] 3 to 5 also includes a second pressing step of pressing the second region 20Y of the decorative sheet 20 against the attachment portion 15. As shown in Fig. 7, the first contact portion CPX overlaps with the second contact portion CPY at a first low-pressure portion RDX located at one end in the first direction D1. As shown in Fig. 7, the pressure from the pressing portion 40 on the portion of the second contact portion CPY that overlaps with the first low-pressure portion RDX is greater than the pressure from the pressing portion 40 on the first low-pressure portion RDX in the first pressing step.

[0117] According to the illustrated method of attaching the decorative sheet 20, the low-pressure region generated by the first pressing step is pressed against the attachment portion 15 with a greater pressure in the second pressing step than in the first pressing step. By being pressed against the attachment portion 15 with a greater pressure than in the first pressing step, the low-pressure region is stably attached to the attachment portion 15. Therefore, it is possible to prevent the decorative sheet 20 attached to the attachment portion 15 from peeling off from the low-pressure region.

[0118] The pressing portion 40 shown in Fig. 6 is in surface contact with the decorative sheet 20. The contact portion CP where the pressing portion 40 and the decorative sheet 20 come into contact extends in a first direction D1 and a second direction D2 perpendicular to the first direction D1, as shown in Fig. 7. By the surface contact of the pressing portion 40 with the decorative sheet 20, the force pressing the decorative sheet 20 against the attachment portion 15 is distributed planarly over the contact portion CP. The pressing portion 40 in surface contact with the decorative sheet 20 can suppress an increase in pressure on the decorative sheet 20 compared to a conventional squeegee that makes line contact with the decorative sheet.

[0119] In the embodiment described above, the decorative sheet 20 is attached to the convexly curved attachment portion 15 of the vehicle body 10. The method for attaching the decorative sheet 20 includes a contacting step in which the decorative sheet 20, whose first portion 201 is held by the holding device 31, is brought into contact with the attachment portion 15 at the second portion 202 separated from the first portion 201, and a pressing step in which the pressing portion 40, which has been in contact with the decorative sheet 20, is moved from the second portion 202 toward the first portion 201, thereby pressing the decorative sheet 20 against the attachment portion 15. In the pressing step, the holding device 31 moves relative to the attachment portion 15 so as to shorten the distance to the contact portion CP between the pressing portion 40 and the decorative sheet 20.

[0120] Furthermore, in the embodiment described above, the attachment device 30 attaches the decorative sheet 20 to the convexly curved attachment portion 15 of the vehicle body 10. The attachment device 30 includes a holding device 31 that holds a first portion 201 of the decorative sheet 20, and a pressing unit 40 that presses the decorative sheet 20 against the attachment portion 15. The pressing unit 40 contacts a second portion 202 that is separate from the first portion 201 of the decorative sheet 20. The pressing unit 40 moves from the second portion 202 toward the first portion 201 while in contact with the decorative sheet 20. The holding device 31 moves relative to the attachment portion 15 so as to shorten the distance to the contact portion CP between the pressing unit 40 and the decorative sheet 20.

[0121] According to this embodiment, it is possible to suppress an increase in tension in the middle portion of the decorative sheet 20 attached to the attachment portion 15. By suppressing an increase in tension in the middle portion of the decorative sheet 20, it is possible to suppress the noticeable observation of streaks extending in a direction perpendicular to the movement direction of the pressing portion 40 at the end position of one pressing operation. Therefore, it is possible to improve the design of the decorative sheet 20 and the decorative member 16 attached to the attachment portion 15.

[0122] Furthermore, in the embodiment described above, the decorative sheet 20 including the bonding layer 24 is attached to the adherend portion 15 of the vehicle body 10 by using the pressing portion 40. The method of attaching the decorative sheet 20 includes a pressing step of pressing the first region 20X of the decorative sheet 20 against the adherend portion 15. In the pressing step, the decorative sheet 20 is pressed against the adherend portion 15 by moving the pressing portion 40 that has come into contact with the decorative sheet 20. The pressing portion 40 contacts the decorative sheet 20 at a first contact portion CPX extending in the first direction D1. The pressure from the pressing portion 40 at the first contact portion CPX decreases to half or less of the maximum value at a first low-pressure portion RDX located at the end in the first direction D1. The full width at half maximum LXF of the pressure from the pressing portion 40 of the first contact portion CPX is 20% or more of the total length LX of the first contact portion CPX.

[0123] According to the present embodiment, in the first contact portion CPX, the pressure for pressing the decorative sheet 20 against the adherend portion 15 is reduced at the first low-pressure portion RDX located at the end in the first direction D1. By reducing the pressure in the low-pressure portion RDX, compression deformation of the bonding layer 24 can be suppressed in the low-pressure region. Therefore, it is possible to suppress the appearance of streaks extending in the moving direction of the pressing portion 40.

[0124] Although the embodiment has been described with reference to specific examples, the above-described specific examples do not limit the embodiment. The above-described embodiment can be implemented with various other specific examples, and various omissions, replacements, changes, additions, etc. can be made without departing from the gist thereof.

[0125] In the method of attaching the decorative sheet 20 described above, the pressing portion 40 is a linear member having a porous structure. The shape of the pressing portion 40 is not limited to linear, and may be planar such as a fabric. Further, the pressing portion 40 may be the hand H of an operator.

[0126] In the method of attaching the decorative sheet 20 described above, in the pressing step where the holding device 31 presses the decorative sheet 20 against the adherend 15, the holding device 31 moved relative to the adherend 15. In the pressing step, the pressing portion 40 moved on the decorative sheet 20, and the holding device 31 moved relative to the adherend 15. The step of moving the holding device 31 relative to the adherend 15 may be a separate step from the pressing step as a moving step. The moving step may be a step after the pressing step. In the moving step, the holding device 31 moves relative to the adherend 15 while the pressing portion 40 remains in contact with the decorative sheet 20 and stops. As described above, the holding device 31 moves relative to the adherend 15 so that the distance to the contact portion CP between the pressing portion 40 and the decorative sheet 20 becomes shorter. By moving the holding device 31 in this way as a moving step after the pressing step, similar to the method of attaching the decorative sheet 20 described above, an increase in the tension in the intermediate portion of the decorative sheet 20 can be suppressed, and the appearance of the first streak can be suppressed from being prominent.

Explanation of Signs

[0127] 10: Vehicle body, 15: Adherend, 20: Decorative sheet, 20X: First region, 20Y: Second region, 20Z: Overlapping region, 21: Base material layer, 22: Design layer, 23: Surface layer, 24: Bonding layer, 30: Attaching device, 31: Holding device, 40: Pressing portion

Claims

1. A method of attaching a decorative sheet to a convexly curved attachment portion of a vehicle body, comprising: a contacting step of bringing the decorative sheet held at a first portion by a holding device into contact with the attachment portion at a second portion away from the first portion; a pressing step of pressing the decorative sheet against the attachment portion by moving a pressing portion contacting the decorative sheet from the second portion toward the first portion, wherein the holding device moves relative to the attachment portion such that a distance to a contact portion between the pressing portion and the decorative sheet becomes shorter in the pressing step. A method for attaching a decorative sheet.

2. A method of attaching a decorative sheet to a convexly curved attachment portion of a vehicle body, comprising: a pressing step of bringing a pressing portion into contact with a decorative sheet held at a first portion by a holding device and moving the pressing portion toward the first portion to press the decorative sheet against the attachment portion; a moving step of moving the holding device relative to the attachment portion such that a distance to a contact portion between the pressing portion and the decorative sheet becomes shorter while the pressing portion remains in contact with the decorative sheet and stops on the decorative sheet. A method for attaching a decorative sheet.

3. The decorative sheet has a first surface and a second surface opposite to the first surface, the decorative sheet is attached to the attachment portion from the second surface, wherein an initial peel strength on the second surface of the decorative sheet is 0.1 N / 25 mm or more. The method for attaching a decorative sheet according to any one of Claims 1 and 2.

4. The decorative sheet has a first surface and a second surface opposite to the first surface, the decorative sheet is attached to the attachment portion from the second surface, wherein a 60° specular glossiness on the first surface of the decorative sheet is 40 or more. The method for attaching a decorative sheet according to Claim 1 or 2.

5. The thickness of the decorative sheet is 0.1 mm or more and 1.0 mm or less. The method for attaching a decorative sheet according to Claim 1 or 2.

6. A method of attaching a decorative sheet including a bonding layer to an attachment portion of a vehicle body by a pressing portion, comprising: a pressing step of pressing a first region of the decorative sheet against the attachment portion by moving the pressing portion contacting the decorative sheet; the pressing portion contacts the decorative sheet at a contact portion extending in a first direction, wherein a pressure from the pressing portion at the contact portion decreases to half or less of a maximum value at an end in the first direction. A method for attaching a decorative sheet, wherein a full width at half maximum of pressure from the pressing portion of the contact portion is 20% or more of a length of the contact portion in the first direction.

7. The method further comprises a second pressing step of pressing a second region that at least partially overlaps with the first region of the decorative sheet against the adherend by moving the pressing portion that has contacted the decorative sheet. An end portion of the contact portion overlaps with a second contact portion where the pressing portion contacts the decorative sheet in the second pressing step. The method for attaching a decorative sheet according to claim 6, wherein pressure from the pressing portion on a portion overlapping with an end portion of the second contact portion is greater than pressure from the pressing portion on the end portion of the contact portion.

8. The method for attaching a decorative sheet according to claim 6 or 7, wherein the contact portion extends planar in the first direction and in a direction non-parallel to the first direction.

9. An attaching device for attaching a decorative sheet to a convexly curved adherend portion of a vehicle body, comprising: a holding device that holds a first portion of the decorative sheet; a pressing portion that presses the decorative sheet against the adherend portion. The pressing portion contacts a second portion away from the first portion of the decorative sheet, and moves from the second portion toward the first portion in a state of contacting the decorative sheet. The holding device moves relative to the adherend portion so that a distance to a contact portion between the pressing portion and the decorative sheet becomes shorter. A decorative sheet attaching device.

Images