JP7472840B2 - Manufacturing method for parts with skin - Google Patents

Description

The present invention relates to a method for manufacturing a skinned part having a base body and a skin material.

A skin-equipped part, which has a base and a skin material, is a part that has the robustness derived from the base and the excellent tactile feel and/or design derived from the skin material. For example, in interior parts mounted on vehicles, skin-equipped parts are used as members that come into direct contact with the user, such as center console box lids and knee pads.
A commonly used method for producing such a skinned part is to place a skin material on a base body and then adhere the two together or to tack them together using a tacking machine.

Incidentally, there are also known skin parts in which not only the surface of the base body but also the side surfaces that are continuous with the surface and the back surface that are continuous with the side surfaces are continuously covered with a skin material. When manufacturing this type of skin part, it is necessary to shape the skin material so that it has a shape that matches the shape of the base body. It has been proposed to use vacuum and pressure forming as a method for shaping the skin material when manufacturing skin parts (see, for example, Patent Document 1).

Patent Document 1 introduces a method of attaching a skin material to a base body by vacuum and pressure molding using an upper chamber and a lower chamber that are closed to each other.
The method introduced in Patent Document 1 is, in essence, a method in which a skin material is held in the upper and lower chambers of a chamber box, the interior of the chamber box is divided into two spaces, an upper and lower, by this skin material, and while the skin material is heated and softened, the lower chamber space is depressurized and the upper chamber space is pressurized, thereby pressing the skin material against a base and covering the base with the skin material.

The vacuum and compressed air molding method introduced in Patent Document 1 is considered to be advantageous as a method for manufacturing skinned parts in which the front, side, and back of a base body are continuously covered with a skin material, since it allows easy shaping of the skin material.

However, the vacuum and pressure forming method introduced in Patent Document 1 has a problem in that the cost required for one vacuum and pressure forming is high. For this reason, there is a need to develop a new manufacturing method for skinned parts.

The inventors of the present invention have conducted extensive research in order to reduce costs and have invented the method of manufacturing a part with skin described in Patent Document 2.
In this method for manufacturing a skinned part, the chamber is divided into a first sub-chamber and a second sub-chamber by a deformable partition member, and the skin is shaped to fit the base via the partition member. In this way, the size of the shaped skin can be made approximately the same as the surface area of the base covered by the skin, i.e., the front, side, and back of the base. Therefore, compared to when the chamber is divided by the skin, the amount of skin to be discarded can be drastically reduced, and the cost required for the skin can be greatly reduced.

Furthermore, in the manufacturing method for a part with skin of Patent Document 2, the partition member is not a constituent element of the part with skin, so that the manufacturing method for a part with skin of Patent Document 2 has the advantage that even a deformed partition member can be reused, and the cost required for the partition member is unlikely to rise significantly.
As a result, the method for manufacturing a part with skin of Patent Document 2 has the advantage that the overall cost required for manufacturing the part with skin can be reduced.

Patent No. 5692101 JP 2020-82616 A

As described above, the method for manufacturing a part with skin of Patent Document 2 can reduce the cost required for manufacturing the part with skin compared to the conventional method for manufacturing a part with skin such as that introduced in Patent Document 1.
However, as with various other parts, there is still a strong demand for cost reduction in skin-equipped parts, and a manufacturing method that can achieve further cost reduction in skin-equipped parts is desired.

The present invention was made in consideration of the above circumstances, and aims to provide a method for manufacturing skinned parts that can reduce costs.

The inventors of the present invention have conducted extensive research to further reduce the manufacturing cost of parts with skin, and aimed to suppress the durability deterioration of the partitioning member used in the manufacturing method of parts with skin of Patent Document 2. The partitioning member is easily deteriorated due to deformation during shaping. Therefore, if the durability deterioration of the partitioning member can be suppressed, it is possible to reduce the manufacturing cost of parts with skin.
In view of this, the inventors of the present invention have sought a method for suppressing the durability deterioration of the partition member and have completed the present invention.

That is, the method for producing a part with skin of the present invention which solves the above-mentioned problems is as follows:
A method for producing a part with skin having a base body and a skin material continuously covering a front surface, a side surface and a back surface of the base body, comprising the steps of:
a preparation step of dividing a chamber, the internal pressure of which can be changed, into a first sub-chamber section and a second sub-chamber section by a deformable dividing member, and placing an intermediate body having the base body and the skin material overlaid on the surface of the base body in the first sub-chamber section with the skin material facing the second sub-chamber section;
a shaping step of, after the preparation step, depressurizing the first sub-chamber while pressurizing the second sub-chamber to deform the partition member and pressurize the intermediate body, and shaping the skin material between the partition member and the base body so as to conform to the front surface, the side surface and the back surface of the base body,
the partition member has a three-dimensional portion having a box-like shape along the front surface and the side surface of the base body, and an extra length portion having a folded-back shape continuous with a peripheral edge portion of the three-dimensional portion,
In the shaping step,
the three-dimensional portion of the partition member presses the skin material toward the front surface and the side surface of the base body,
In the method for manufacturing a part with skin, the excess portion of the partition member is pressed against the back surface of the base body by pressing the skin material against the back surface of the base body.

The manufacturing method of the skinned parts of the present invention can reduce the manufacturing costs of the skinned parts by suppressing the durability deterioration of the partition member.

1A to 1C are explanatory diagrams illustrating a method for manufacturing a skin-attached part according to a first embodiment of the present invention; 1A to 1C are explanatory diagrams illustrating a method for manufacturing a skin-attached part according to a first embodiment of the present invention; 1A to 1C are explanatory diagrams illustrating a method for manufacturing a skin-attached part according to a first embodiment of the present invention; 1A to 1C are explanatory diagrams illustrating a method for manufacturing a skin-attached part according to a first embodiment of the present invention; 1A to 1C are explanatory diagrams illustrating a method for manufacturing a skin-attached part according to a first embodiment of the present invention; 1A to 1C are explanatory diagrams illustrating a method for manufacturing a skin-attached part according to a first embodiment of the present invention; 13A and 13B are explanatory diagrams illustrating a partition member according to a modified example. 13A and 13B are explanatory diagrams illustrating a partition member according to a modified example.

The following describes the mode for carrying out the present invention. Unless otherwise specified, the numerical range "a to b" described in this specification includes the lower limit a and the upper limit b. Numerical ranges can be formed by arbitrarily combining these upper and lower limit values, as well as the numerical values listed in the examples. Furthermore, a numerical value arbitrarily selected from within these numerical ranges can be used as a new upper or lower limit numerical value.

In the manufacturing method of the skinned part of the present invention, similar to the manufacturing method of the skinned part of Patent Document 2, the chamber is divided into a first sub-chamber section and a second sub-chamber section by a deformable partition member, and the skin material is shaped to fit the base body via the partition member. In this way, the size of the shaped skin material can be made approximately the surface area of the base body covered by the skin material, i.e., the size of the front, side and back surfaces of the base body. Therefore, according to the manufacturing method of the skinned part of the present invention, the amount of skin material discarded can be dramatically reduced compared to the case where the chamber is divided by skin material as in the technology introduced in Patent Document 1, and the cost required for the skin material can be greatly reduced.

Moreover, in the method for manufacturing a part with skin of the present invention, the partition member is not a constituent element of the part with skin, as in the method for manufacturing a part with skin of Patent Document 2. Therefore, in the method for manufacturing a part with skin of the present invention, it is possible to reuse the deformed partition member.
Furthermore, in particular, in the manufacturing method of the skinned part of the present invention, by forming the partition member into a shape having a three-dimensional portion and an excess portion, it is possible to suppress the durability deterioration of the partition member, thereby making it possible to further significantly reduce the manufacturing cost of the skinned part.

The inventors of the present invention closely observed the deformation of the partition member during the process of manufacturing a skinned part based on the method of Patent Document 2. In the process, the inventors noticed that the amount of deformation of the partition member was large in the portion of the partition member where the skin material was pressed against the back surface of the base body. This portion penetrates into the back surface of the base body when the skin material is shaped. For this reason, the amount of deformation of this portion is larger than the amount of deformation of other portions of the partition member, and it is believed that as the skin material is repeatedly shaped, it undergoes plastic deformation and durability deterioration.

The inventors of the present invention came up with the idea of designing the above-mentioned partitioning members with the largest deformations to have a generous shape, anticipating deformation during shaping.

In other words, in the method for manufacturing a skinned part of the present invention, the partition member has a three-dimensional portion having a box-like shape that fits along the front and side surfaces of the base body, and an excess portion that forms a folded-back shape that continues from the periphery of the three-dimensional portion. Of these, the three-dimensional portion is the portion that presses the skin material against the front and side surfaces of the base body in the shaping process in which the skin material is shaped. Also, the excess portion is the portion that presses the skin material against the back surface of the base body in the shaping process. Because the excess portion has a folded-back shape, its length increases when the excess portion is expanded.

In the partition member in the manufacturing method for parts with skin of Patent Document 2, the portion corresponding to the excess portion is the portion that deforms greatly, but in the partition member in the manufacturing method for parts with skin of the present invention, the excess portion can be extended by the length that was folded back. Therefore, in the partition member in the manufacturing method for parts with skin of the present invention, the substantial amount of elongation deformation in the shaping process is reduced, and the force acting on the excess portion in the shaping process is also reduced. As a result, the partition member in the manufacturing method for parts with skin of the present invention is resistant to plastic deformation and durability deterioration, and can withstand repeated use. Therefore, the manufacturing method for parts with skin of the present invention can reduce the manufacturing costs of parts with skin.

Hereinafter, as necessary, the manufacturing method of the skin-equipped part of the present invention, the manufacturing method of the skin-equipped part of the examples, etc. may be abbreviated to simply "the manufacturing method of the present invention," "the manufacturing method of the examples," etc. Below, the manufacturing method of the skin-equipped part of the present invention will be explained step by step.

The method for producing a part with skin of the present invention includes a preparation step and a shaping step.
The preparation step is a step of placing a partition member and an intermediate body in a chamber used for shaping the skin material. The intermediate body has a base body and a skin material overlaid on the surface of the base body.

The chamber may be any chamber capable of changing the internal pressure, for example, a chamber of a vacuum forming machine or a vacuum/pressure forming machine may be used.
The partition member may be any material that is deformable, and may be made of a material such as fabric that deforms but does not elastically deform. However, as described below, it is preferable to use a material that is elastically deformable, such as silicone rubber.

In the preparation process, the chamber is divided into a first sub-chamber section and a second sub-chamber section by a partitioning member. Then, the intermediate body described above is placed in the first sub-chamber section with the skin facing the second sub-chamber section. At this time, the skin of the intermediate body faces the partitioning member that separates the first sub-chamber section and the second sub-chamber section.

In the manufacturing method of the present invention, a shaping step is carried out after the above-mentioned preparation step.
In the shaping step, the pressure inside the first sub-chamber is reduced while the pressure inside the second sub-chamber is increased, thereby deforming the partition member toward the first sub-chamber and pressing the intermediate body, thereby shaping the skin material between the partition member and the base body so as to conform to the front, side and back surfaces of the base body.

More specifically, as described above, the partition member has a three-dimensional portion and an excess portion, and the three-dimensional portion has a box-like shape that conforms to the front and side surfaces of the base. Therefore, the skin material is shaped by the three-dimensional portion into a shape that conforms to the front and side surfaces of the base. The excess portion is also continuous with the peripheral portion of the three-dimensional portion. Therefore, the skin material is shaped by the excess portion into a shape that conforms to the back surface of the base.

The three-dimensional portion is box-shaped and conforms to the surface and side of the base. In other words, the three-dimensional portion has a concave inner surface having a first shaping surface that conforms to the surface of the base, and a second shaping surface that is continuous with the first shaping surface and conforms to the side of the base.

Because the three-dimensional portion is box-shaped and conforms to the surface and sides of the base, the amount of deformation of the partition member during the shaping process is small in the three-dimensional portion. Therefore, the durability deterioration of the partition member described above is greatly suppressed in the three-dimensional portion.

The three-dimensional part needs only to be box-shaped with the inner surface described above, and the thickness does not need to be constant, but considering durability, it is preferable for it to be a sheet-like shape with a roughly constant thickness. This is to avoid stress concentrating in specific locations during shaping.

The three-dimensional portion may, for example, continuously cover the entire surface and the entire side surface of the base, or may continuously cover the entire surface and part of the side surface of the base. Considering the position of the excess length portion described below, it is preferable that the three-dimensional portion covers at least half of the side surface of the base in the height direction. The height of the side surface of the base corresponds to the shortest distance between the side end of the base, i.e., the end of the side surface of the base that is farthest from the surface, and the surface of the base.

Incidentally, it is particularly preferable that the length L1 of the second shaping surface of the three-dimensional portion described above is the same as the height L3 of the side surface of the base, but in the manufacturing method of the present invention, some stretching deformation of the three-dimensional portion and the excess portion is allowed. Also, if the length L2 of the excess portion is sufficiently long, the side surface of the base can be covered by a part of the excess portion in addition to the second shaping surface. Therefore, the length L1 of the second shaping surface may be slightly shorter than the height L3 of the side surface of the base.
The length L1 of the second shaping surface in the three-dimensional portion means the shortest distance from the end of the second shaping surface on the opposite side to the first shaping surface to the end of the first shaping surface.

Specifically, the length L1 of the second shaping surface is preferably at least 1/2 of the height L3 of the side surface of the base, more preferably at least 2/3, and even more preferably at least 3/4. As mentioned above, it is particularly preferable that the length L1 of the second shaping surface is the same as the height L3 of the side surface of the base.

The excess length portion is continuous with the peripheral portion of the three-dimensional portion. The peripheral portion of the three-dimensional portion is the portion of the three-dimensional portion that covers the side surface of the base, and the excess length portion that is continuous with the peripheral portion can be said to be the portion that covers the back surface that is continuous with the side surface of the base.

The shape of the excess portion may be a folded shape, for example, a U-shaped cross section. The folded end of the excess portion may be oriented in any direction. For example, the excess portion may bulge toward the radially outer side of the three-dimensional portion. In this case, the folded end of the excess portion is oriented toward the radially outer side of the three-dimensional portion. The excess portion may also be recessed toward the radially inner side of the three-dimensional portion. In this case, the folded end of the excess portion is oriented toward the radially inner side of the three-dimensional portion. Furthermore, the folded end of the excess portion may be oriented in the height direction of the three-dimensional portion, i.e., in either the length direction of the second shaping surface in the three-dimensional portion.
Moreover, the extra length portion may have two or more folded end portions, and may be, for example, bellows-shaped.

The excess portion has a folded shape and serves the function of pressing the skin material of the partition member against the back surface of the base body. Such excess portion only needs to have a length sufficient to press the skin material against the back surface of the base body.

The length L2 of the excess part may be determined according to the length of the part of the skin material that covers the back surface of the substrate, and is not particularly limited, but preferable lengths include, for example, ranges of 30 mm or more, 40 mm or more, and 50 mm or more. Note that, in cases where the jig supporting the intermediate body protrudes significantly into the chamber in the shaping step, depending on the positional relationship between the jig and the partition member, the length L2 of the excess part may be further increased according to the protruding length of the jig.
The length L2 of the extra length does not mean the length in a folded state, but the length in an unfolded state.

In the manufacturing method of the present invention, for example, an adhesive may be applied to the base and/or the skin material in advance, and the skin material may be shaped in the first sub-chamber and attached to the base at the same time. Alternatively, the shaped base and skin material may be removed from the first sub-chamber, and the shaped skin material may be fixed to the base by adhesive, welding, riveting, etc. Furthermore, the shaped skin material may be removed from the base, and then re-fixed to the base.
That is, the manufacturing method of the present invention may include a bonding step of bonding the skin material to the substrate, the shaping step and the bonding step may be carried out simultaneously, or the bonding step may be carried out after the shaping step.

As described above, the substrate has a front surface, a side surface, and a back surface. The back surface is a surface facing away from the front surface, and the side surface is a surface connecting the front surface and the back surface. The material and shape of the substrate are not particularly limited, but since the skin material is shaped to fit the substrate, the substrate is less likely to deform than the skin material and the partition member. In addition, due to the above-mentioned circumstances, the substrate is preferably thicker than the skin material.
As the material for the substrate, various materials such as metals, plastics, and ceramics can be used.

The skin material is pressed against the partition member to give it a shape. For example, skin materials made of natural materials such as leather, woven or nonwoven fabrics made of natural fibers, or non-natural materials such as polymer sheets or synthetic rubber sheets can be used. Other materials for the skin material include thermoplastic polymers such as acrylic resin, polyethylene, polyvinyl chloride, and thermoplastic polyurethane, or polymers that have no thermoplasticity or low thermoplasticity. These polymers may be molded into a sheet or plate shape by known methods such as mold molding or press molding, or these polymers may be molded into fibers by methods such as extrusion molding, and then further molded into a woven or nonwoven fabric to use as the skin material.

The skin material may be large enough to continuously cover the front, side, and back surface of the base. For example, the skin material may be large enough to cover the entire front surface, all of the side surfaces, and part of the back surface of the base. The skin material may cover the entire front surface of the base, or only a part of the front surface. Similarly, for the side surfaces that are continuous with the front surface, the skin material may cover the entire side surface or only a part of the side surface. Similarly, for the back surface that is continuous with the side surfaces, the skin material may cover the entire back surface or only a part of the back surface.

The above-mentioned skin material and base are provided to the shaping process as an intermediate body in which the skin material is layered on the surface of the base. The skin material in the intermediate body may be fixed to the base or simply layered on the base, but in order to obtain a skinned part in which the desired portion of the base is covered with the skin material, it is preferable that the skin material in the intermediate body is positioned relative to the base and temporarily fixed to the base. In this case, it is sufficient that a portion of the skin material is fixed to the base.

For example, when the shaping step and the fixing step are carried out simultaneously, it is advisable to preliminarily bond the entire surface of the substrate to the entire portion of the skin material that faces the surface (hereinafter referred to as the surface-facing portion). In this case, it is also advisable to apply adhesive to at least one of the side and back surfaces of the substrate and the remaining portion of the surface of the skin material that faces the substrate, and to carry out the shaping step before the adhesive hardens.

When the fixing step is performed after the shaping step, the surface of the base body and the facing surface of the skin material may be bonded in advance. In this case, the surface of the base body and the facing surface of the skin material may be bonded to each other over the entire surface, or may be bonded partially. Furthermore, the two may be temporarily bonded together using a removable method such as double-sided tape.

During the shaping process, the intermediate body is placed in the first sub-chamber of the vacuum and pressure molding machine.

The first sub-chamber is a space in the vacuum and pressure molding machine that can be depressurized and pressurized, i.e., a part of the chamber. Specifically, the chamber is divided into a first sub-chamber and a second sub-chamber by the partition member described above, and the first sub-chamber, in which the intermediate body is placed, can be depressurized, while the second sub-chamber can be pressurized.
The intermediate body has the skin facing the second sub-chamber portion (in other words, the partition member side) and the base facing the opposite side.

When the pressure inside the first sub-chamber is reduced and the pressure inside the second sub-chamber is increased, the partitioning member that separates the first and second chambers is deformed. This reduces the volume of the first sub-chamber and increases the volume of the second sub-chamber. At this time, the partitioning member is pressed against the intermediate body placed in the first sub-chamber, and deforms to conform to the outer shape of the intermediate body. Therefore, it can be said that the skin material is pressed toward the base body together with the partitioning member. The skin material pressed toward the base body is rolled up toward the side and back surface of the base body, and shaped to conform to the side and back surface.

The decompression device for reducing the pressure inside the first sub-chamber and the pressurization device for pressurizing the second sub-chamber may be a known decompression device or pressurization device such as a decompression pump or a pressurization pump. Both the first sub-chamber and the second sub-chamber may be capable of reducing and pressurizing the pressure.

In particular, it is preferable that the second sub-chamber can be depressurized and pressurized. For example, when the first and second sub-chambers are at atmospheric pressure, the internal pressures of the first and second sub-chambers are balanced, and the partition member separating the first and second sub-chambers is in a steady state with a small amount of deformation. If the first sub-chamber is depressurized and the second sub-chamber is pressurized from this state, the internal pressure difference between the first and second sub-chambers increases rapidly, causing the partition member to deform rapidly. This rapid deformation may cause the partition member to plastically deform to an extent that makes it difficult to reuse it.

When the first and second sub-chambers are at atmospheric pressure and the partition member is in a steady state, and then the first and second sub-chambers are first reduced pressure, the internal pressures of the first and second sub-chambers become approximately equal, and the partition member is maintained in a steady state. At this time, the difference between the internal pressures of the first and second sub-chambers is preferably 20% or less, more preferably 15% or less, and particularly preferably 10% or less. Of course, it is most preferable that the internal pressures of the first and second sub-chambers are the same.

Next, by gradually pressurizing the second sub-chamber while maintaining the first sub-chamber at reduced pressure, the internal pressure difference between the first and second sub-chambers gradually increases, causing the partition member to deform gradually. Therefore, this method makes it possible to reduce the pressure in the first sub-chamber and pressurize the second sub-chamber while preventing sudden deformation of the partition member.
In this case, by suppressing plastic deformation of the partition member and increasing the number of times the partition member can be reused, the costs required for the partition member can be reduced, which has the advantage of reducing the manufacturing costs of the skinned parts.

In the shaping process, it is preferable to carry out an internal pressure operation to make the internal pressure of the first sub-chamber equal to that of the second sub-chamber just before the internal pressure operation to reduce the pressure in the first sub-chamber while pressurizing the second sub-chamber, regardless of the state of the partitioning member. Hereinafter, as necessary, the internal pressure operation to reduce the pressure in the first sub-chamber while pressurizing the second sub-chamber is referred to as a vacuum/pressure operation, and the internal pressure operation to make the internal pressure of the first sub-chamber equal to that of the second sub-chamber is referred to as an adjustment operation. By carrying out the adjustment operation just before the vacuum/pressure operation, sudden deformation of the partitioning member can be suppressed regardless of the state of the partitioning member.

Considering that the partition member should sufficiently press the intermediate body and should provide the partition member with sufficient durability, it is preferable to use an elastically deformable partition member, and more preferably a plate or sheet made of natural rubber, urethane, polyethylene, silicone rubber, or the like. In terms of the elastic properties of the partition member, the elongation of the partition member (elongation at break according to JIS K6251:2017) is preferably in the range of 500 to 1500%, more preferably in the range of 600 to 1200%, and particularly preferably in the range of 800 to 1000%. The elastic modulus of the partition member is preferably in the range of 0.5 to 1.2, more preferably in the range of 0.6 to 1.0, and particularly preferably in the range of 0.7 to 0.9. The elastic modulus can be calculated from stress/strain.

For reference, the elongation rate of the skin material is preferably within the range of 5 to 250%, and more preferably within the range of 10 to 200%.

As mentioned above, the partition member separates the first and second sub-chamber sections. The chamber may be configured in any way as long as the interior can be depressurized and pressurized, but it is reasonable to form the partition between two box sections, similar to the chambers of general vacuum and pressure molding machines. One of the two box sections is referred to as the first box section, and the other as the second box section.

The first box section and the second box section are combined to partition the chamber, so it is advisable to use the partition member sandwiched between the first box section and the second box section. The first sub-chamber section is formed by the inner surface of the first box section and the partition member, and the second sub-chamber section is formed by the inner surface of the second box section and the partition member.

The partition member may be fixed to either the first box part or the second box part. There is no particular limit to the method of fixing the partition member to the first box part and the second box part, and any known method such as adhesion or screw fastening may be used.
The partition member may be fixed to either the first box portion or the second box portion, but for the convenience of placing the intermediate body in the first sub-chamber portion during the shaping process, it is preferable to fix the partition member to the peripheral portion of the inner surface of the second box portion.
The portion of the partition member that is fixed to the first box portion and/or the second box portion is the peripheral portion of the partition member. The peripheral portion may be, for example, an end portion of the excess portion. Alternatively, for example, if the partition member has a portion for fixing (hereinafter, referred to as a fixing portion as necessary) further outboard than the excess portion, the fixing portion may be the peripheral portion that is fixed to the first box portion and/or the second box portion.

In the manufacturing method of the present invention, the partition member may be sandwiched between the first box portion and the second box portion via a frame portion that is separate from the partition member. The frame portion is preferably a material that is less likely to deform than the partition member. The frame portion may be fixed to the first box portion or the second box portion by a known method such as gluing or screwing. It is preferable that the frame portion is fixed to the second box portion.

However, if the partition member deteriorates in durability due to repeated shaping processes, it is necessary to replace the partition member. To easily replace the partition member, it is preferable to sandwich the partition member between two frame parts, or to sandwich the partition member between the frame part and the peripheral part of the inner surface of the first box part or the second box part. In this case, it is more preferable to interpose a sealant between the partition member and the frame part, or between the partition member and the peripheral part of the inner surface of the first box part or the second box part. As the sealant, a known sealant such as a rubber O-ring can be used. As the sealant, a fluid sealant such as grease can also be used.

The manufacturing method for the skinned parts of the present invention will be explained below with specific examples.

Example 1
1 to 6 are explanatory diagrams that diagrammatically show a method for manufacturing a part with skin according to a first embodiment.
Hereinafter, the terms "upper" and "lower" refer to the upper and lower directions shown in Fig. 1. As will be described later, the upper and lower directions can be rephrased as the opening and closing directions of the first box portion and the second box portion.

First, a vacuum and pressure forming machine 1 used in the method for producing the skinned part of the first embodiment will be described.
As shown in FIG. 1 , the vacuum and pressure air molding machine 1 has a first molding section 2 having a first box section 20, a second molding section 3 having a second box section 30, a partition member 4, and a lifting device 10.

As shown in FIG. 1, the first molding section 2 has a first box section 20 and a mounting jig 11 arranged within the first box section 20.

The lifting device 10 has the function of changing the position of the second box section 30 in the vertical direction to open and close the chamber box 15 consisting of the first box section 20 and the second box section 30, and the function of changing the position of the mounting jig 11 in the vertical direction relative to the first box section 20 to change the positional relationship between the first box section 20 and the mounting jig 11 in the vertical direction, i.e., in the opening and closing direction of the chamber box 15.

The lifting device 10 in the vacuum/compressed air molding machine 1 used in the manufacturing method of the skinned part of Example 1 is composed of a box-side lifting element 12 attached to the second box section 30 and changing the position of the second box section 30 in the vertical direction, a mounting jig-side lifting element 13 attached to the mounting jig 11 and changing the position of the mounting jig 11 in the vertical direction, and a motor M connected to the box-side lifting element 12 and the mounting jig-side lifting element 13.

The second box portion 30 is shaped like a box and opens downward. The second box portion 30 is provided with a second air vent 31 having a through-hole shape. One of the two openings of the second air vent 31 opens to the inside of the second box portion 30. The other of the two openings is connected to a pressure reducing/pressurizing device (not shown) arranged outside the second box portion 30.
The box-side lifting element 12 is arranged outside the second box section 30 .

The first box section 20 is box-shaped and opens upward. The first box section 20 also has a first air vent 21 in the form of a through hole. One of the two openings of the first air vent 21 opens into the interior of the first box section 20. The other of the two openings is connected to a pressure reducing device (not shown) arranged outside the first box section 20.

The mounting jig 11 and an internal element 13a that is a part of the mounting jig side lifting element 13 are arranged inside the first box portion 20. The mounting jig 11 is fixed to the internal element 13a. The internal element 13a, together with an external element (not shown), constitutes the mounting jig side lifting element 13. The external element (not shown) is arranged outside the first box portion 20, and the internal element 13a and the external element are connected.
The intermediate body 5 is placed on the mounting jig 11 .

Intermediate 5 will now be described.
As shown in FIG. 6 , the intermediate body 5 has a base body 50 and a skin material 55 laminated on the base body 50 .
The base 50 is made of ABS and has a generally plate-like shape with an end portion curved downward in a generally L-shape. The base 50 has a front surface 50f facing upward and a back surface 50b facing downward.
A front facing portion 56 of the skin material 55 is bonded to the front surface 50f of the base body 50. The front surface 50f and the front facing portion 56 of the base body 50 are bonded to each other over their entire surfaces. An adhesive is also applied to the side surface 50s and the outer peripheral portion 50bo of the back surface 50b of the base body 50. The adhesive applied to the side surface 50s and the outer peripheral portion 50bo of the back surface 50b of the base body 50 is not yet cured.

Here, the skin material 55 is made of polyvinyl chloride and urethane as a cushioning material, and is large enough to cover the entire surface 50f of the base body 50, the entire side surface 50s, and the outer peripheral portion 50bo of the back surface 50b.

The partition member 4 in the manufacturing method of the skinned part of Example 1 is a sheet made of silicone rubber. As shown in FIG. 6, the partition member 4 has a three-dimensional portion 40, an excess portion 41, and a fixing portion 42.

The three-dimensional portion 40 has a box-like shape, and the inner surface 40i of the three-dimensional portion 40 is concave, having a first shaping surface 40if shaped to fit the surface 50f of the base 50, and a second shaping surface 40is that is continuous with the first shaping surface 40if and shaped to fit the side surface 50s of the base 50. Therefore, the three-dimensional portion 40 can be said to have a box-like shape that fits the surface 50f and side surface 50s of the base 50.

The excess portion 41 is continuous with the peripheral portion 40o of the three-dimensional portion 40 and has a folded shape that bulges outward in the radial direction of the three-dimensional portion 40. The folded end portion 43 of the excess portion 41 faces outward in the radial direction of the three-dimensional portion 40. The excess portion 41 can also be said to have a bag shape with a roughly U-shaped cross section.

The partition member 4 has a fixing portion 42 further outward than the excess portion 41. A reinforcing portion 44 that is folded back in an approximately U-shape is formed at the boundary between the fixing portion 42 and the excess portion 41. The reinforcing portion 44 is provided to increase the rigidity of the partition member 4 at the boundary between the excess portion 41 and the fixing portion 42, and contributes to maintaining the shape of the partition member 4.

In the manufacturing method of Example 1, the length L1 of the second shaping surface 40is of the three-dimensional portion 40 is approximately the same as the height L3 of the side surface of the base body. In addition, the length L2 of the excess portion (the sum of _L20 , _L21 , and _L23 shown in FIG. 6) is approximately 50 mm.

Below, the manufacturing method for the skinned part of Example 1 will be explained step by step.

[Preparation process]
1, the second box portion 30 is moved upward by the box-side lifting element 12 to open the chamber box 15 including the first box portion 20 and the second box portion 30. In the open state, the fixing portion 42 of the partition member 4 is fixed to the peripheral portion 30p of the inner surface 30i of the second box portion 30.

As described above, the chamber box 15 is opened, and the intermediate body 5, in which the base body 50 and the skin material 55 are integrated, is placed inside the first box section 20, specifically on the mounting jig 11. At this time, the intermediate body 5 has the base body 50 facing downward, i.e., toward the mounting jig 11, and the skin material 55 facing upward, i.e., toward the second box section 30.

Then, the second box section 30 is moved downward by the box-side lifting element 12, bringing the chamber box 15 into the closed state shown in FIG. 2. Because the fixing part 42 of the partition member 4 is fixed to the second box section 30, the partition member 4 moves downward together with the second box section 30 and is sandwiched between the first box section 20 and the second box section 30. Therefore, as shown in FIG. 2, the chamber 16 of the chamber box 15 is divided into a first sub-chamber section 17 defined by the first box section 20 and the partition member 4, and a second sub-chamber section 18 defined by the second box section 30 and the partition member 4.

At this time, the three-dimensional portion 40 of the partition member 4 is disposed above the skin material 55 , and the excess portion 41 of the partition member 4 is disposed to the side of the skin material 55 .
At this time, the interiors of first sub-chamber 17 and second sub-chamber 18 are both at atmospheric pressure, and partition member 4 is in a steady state with only a small amount of deformation from its natural state.

[Shaping process]
In the shaping process, first, the inside of first sub-chamber 17 is depressurized by a not shown depressurization device, and the inside of second sub-chamber 18 is depressurized by a not shown depressurization/pressurization device. At this time, the internal pressures of first sub-chamber 17 and second sub-chamber 18 are each about 0 MPa, and the internal pressure difference between first sub-chamber 17 and second sub-chamber 18 is about 10%. By simultaneously depressurizing the insides of first sub-chamber 17 and second sub-chamber 18, the occurrence of an internal pressure difference between first sub-chamber 17 and second sub-chamber 18 is suppressed, and partition member 4 remains in the steady state shown in FIG. 2 .

Next, the mounting jig 11 is moved upward, i.e., toward the second box section 30, by the mounting jig lifting element 13. Then, as shown in FIG. 3, the intermediate body 5 placed on the mounting jig 11 moves upward together with the mounting jig 11 and enters the partition member 4. Specifically, at this time, substantially the entire base body 50 and most of the skin material 55 enter the three-dimensional section 40 of the partition member 4. The peripheral portion of the skin material 55 is covered from the outside by the excess portion 41 of the partition member 4.

Next, as shown in FIG. 4, the inside of the second sub-chamber 18 is pressurized while the inside of the first sub-chamber 17 is kept depressurized. This increases the internal pressure difference between the first sub-chamber 17 and the second sub-chamber 18, causing the partition member 4 to deform.

Specifically, the three-dimensional portion 40 of the partition member 4 deforms toward the surface 50f and the side surface 50s of the base body 50, whereby the portion of the skin material 55 sandwiched between the three-dimensional portion 40 and the base body 50 is pressed toward the surface 50f and the side surface 50s of the base body 50. Therefore, the skin material 55 is shaped by the three-dimensional portion 40 into a shape that conforms to the surface 50f and the side surface 50s of the base body 50.
Furthermore, the excess portion 41 of the partition member 4 deforms toward the back surface 50b of the base 50 and the front surface of the mounting jig 11, whereby the peripheral portion of the skin material 55 is pressed toward the back surface 50b of the base 50 and rolled up toward the back surface 50b of the base 50. Therefore, the skin material 55 is shaped by the excess portion 41 into a shape that conforms to the back surface 50b of the base 50, more specifically, the outer peripheral portion 50bo of the back surface 50b.

The partition member 4 has an excess length portion 41 that has a folded shape, and the excess length portion 41 can be expanded by the length that it was folded back. Therefore, at this time, the excess length portion 41 is simply expanded, and there is almost no actual amount of stretching deformation. In addition, since the three-dimensional portion 40 has approximately the same shape as the surface 50f and side surface 50s of the base body, there is almost no amount of stretching deformation of the three-dimensional portion 40.

As mentioned above, uncured adhesive is applied to the side surface 50s of the base body 50 and the peripheral portion 50bo of the back surface 50b, so in this process, the skin material 55 is shaped to fit the base body 50 and the base body 50 and the skin material 55 are bonded together.

Next, the depressurization of the first sub-chamber 17 and the pressurization of the second sub-chamber 18 are stopped, and the first sub-chamber 17 and second sub-chamber 18 are set to atmospheric pressure. Then, as shown in FIG. 5, the second box 30 is moved upward, the chamber box 15 is opened, and the intermediate body 5 after the skin material 55 has been formed, i.e., the skin-equipped part 6 of Example 1, is removed. The skin-equipped part 6 of Example 1 is left to stand for a desired period of time to harden the adhesive, thereby making the adhesion between the base and the skin material 55 stronger.

According to the manufacturing method of the skinned part of Example 1, by providing the partition member 4 with the excess length portion 41, it is possible to suppress the elongation deformation of the partition member 4 during the shaping process. This effectively suppresses the durability deterioration of the partition member 4, and reduces the manufacturing cost of the skinned part 6.

(Modification)
Another embodiment of the partition member in the manufacturing method of the present invention will be described as a modified example.
7 and 8 are explanatory diagrams that typically show modified partition members.

The excess portion 41 of the partition member 4 shown in Figure 7 has three folded ends 43, two of which face radially inward of the three-dimensional portion 40 and the other faces radially outward of the three-dimensional portion 40, forming an accordion-like shape.
Further, the excess length portion 41 of the partition member 4 shown in FIG. 8 has two folded end portions 43, one of which faces upward and the other faces downward, forming a bellows shape.
Even in these cases, the excess portion 41 of the partition member 4 can be expanded by the length that was folded back. Therefore, in the shaping step, the amount of elongation deformation of the partition member 4 is small, and the three-dimensional portion 40 of the partition member 4 shapes the skin material 55 into a shape that conforms to the front surface 50f and side surface 50s of the base body 50, while the excess portion 41 of the partition member 4 shapes the skin material 55 into a shape that conforms to the back surface 50b of the base body 50. Therefore, even in these modified examples, the durability deterioration of the partition member 4 is suppressed, and the manufacturing cost of the skin-attached part is reduced.

The manufacturing method for skinned parts of the present invention has been explained above based on examples, but the present invention is not limited to the embodiments and examples described above and shown in the drawings, and can be modified as appropriate without departing from the gist of the present invention. In addition, each of the components shown in this specification, including the embodiments, can be arbitrarily extracted and combined for implementation.

4: Compartment member 5: Intermediate body 6: Part with skin 16: Chamber 17: First sub-chamber section 18: Second sub-chamber section 20: First box section 30: Second box section 40: Three-dimensional section 41: Excess length section 50: Base body 50f: Surface of base body 50b: Back surface of base body 50s: Side surface of base body 55: Skin material

Claims (3)

A method for producing a part with skin having a base body and a skin material continuously covering a front surface, a side surface and a back surface of the base body, comprising the steps of:
a preparation step of dividing a chamber, the internal pressure of which can be changed, into a first sub-chamber section and a second sub-chamber section by a deformable dividing member, and placing an intermediate body having the base body and the skin material overlaid on the surface of the base body in the first sub-chamber section with the skin material facing the second sub-chamber section;
a shaping step of, after the preparation step, depressurizing the first sub-chamber while pressurizing the second sub-chamber to deform the partition member and pressurize the intermediate body, and shaping the skin material between the partition member and the base body so as to conform to the front surface, the side surface and the back surface of the base body,
In an initial shape, the partition member has a three-dimensional portion having a box-like shape along the front surface and the side surface of the base body, and an extra length portion having a folded-back shape continuous with a peripheral edge portion of the three-dimensional portion,
In the shaping step,
the three-dimensional portion of the partition member is deformed from the initial shape so as to press the skin material toward the front surface and the side surface of the base body,
the excess portion of the partition member is deformed from the initial shape so as to press the skin material toward the back surface of the base body. The method for manufacturing a skinned part according to claim 1, wherein the partition member is elastically deformable. The method for manufacturing a skinned part according to claim 1 or 2, wherein in the initial shape , the excess portion bulges outward in the radial direction of the three-dimensional portion.

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