Patent Description:
Surface-layered parts include, for example, an interior part of an automobile or other vehicle. Such an interior part of an automobile or other vehicle may be formed by covering the front side of a flat base member with a surface layer member (see, for example, <CIT>). Interior parts of an automobile or other vehicle include an armrest installed inside the automobile. The cross-sectional shape of the flat base member of an armrest is convex on the side that faces the surface layer member. The base member is typically a rigid structure made of polypropylene (PP). The surface layer member is arranged on the front side of the base member, so as to conform to the surface of the base member. The surface layer member is typically made of a stretchable olefin-based elastomer into such a form so as to cover the front side of the base member.

<FIG> is an exploded perspective view of a base member <NUM> and a surface layer member <NUM>. <FIG> shows the base member <NUM> assembled with the surface layer member <NUM> covering the base member <NUM>. As shown in <FIG>, the surface layer member <NUM> includes wrapping portions <NUM> at its edge <NUM>. The wrapping portions <NUM> are configured to wrap the corresponding edges <NUM> of the base member <NUM>. Assembly of the surface layer member <NUM> with the base member <NUM>, in a covering manner, is performed by fitting the wrapping portions <NUM> over the respective edges <NUM> of the base member <NUM>.

The base member <NUM> includes one or more claw <NUM> on one of its edges <NUM> at locations corresponding to the wrapping portions <NUM> of the surface layer member <NUM>, as shown on the left side of <FIG>. Correspondingly, the wrapping portions <NUM> of the layer surface member <NUM> each include an engagement hole <NUM>. Each engagement hole <NUM> in the surface layer member <NUM> is hooked on the corresponding claw <NUM>. The engagement hole <NUM> is essentially locked so that the surface layer member <NUM> is positioned in place, with reference to the base member <NUM>, in a reliable manner.

The work of fitting the wrapping portion <NUM> of the surface layer member <NUM> onto the edge <NUM> of the base member <NUM> described above is conventionally performed manually by hand.

Apparatuses and methods for wrapping an edge of a surface layer member over an edge of a base member are described in other documents. <CIT> describes a device and method for bending a covering material over a base material. <CIT> describes a vehicle component part where a folded terminal portion of a skin material is folded around an outer peripheral portion of a base material, and connectable insertion parts and recesses are spaced circumferentially on the leading edge of the skin material. <CIT> describes a fastening structure for a member, the fastening structure formed by fitting a hole and a fitting protrusion together.

The above-mentioned manual work of fitting the wrapping portion <NUM> of the surface layer member <NUM> onto the edge <NUM> of the base member <NUM> relies on the physical power of workers, which requires many man-hours, thereby leading to poor productivity. In addition, the manual work tends to create variations in the quality of a mass-produced product.

In particular, when manually performing the task by hand, hooking the claws <NUM> into the engagement holes <NUM> formed in the wrapping portion <NUM> is a hard work that puts a heavy burden on the workers' hands and fingers. This results in the problem of an increase in the number of man-hours required for the work.

It is desired to improve the productivity in manufacturing surface-layered parts by automating the work of fitting the wrapping portion of the surface layer member onto the edge of the base member.

The object is achieved by the apparatus of claim <NUM> and the method of claim <NUM>. Advantageous further developments are subject-matter of the dependent claims.

In some embodiments, the base member includes a claw formed at the edge of the base member, and the surface layer member includes an engagement hole at the wrapping portion formed at the edge of the surface layer member. The engagement hole is engageable with the claw. Fitting the wrapping portion of the surface layer member onto the edge of the base member causes the engagement hole to engage the claw.

Embodiments of the present disclosure will be described below with reference to the drawings. In one embodiment, a surface-layered part may be an automobile armrest. An apparatus and a method for manufacturing an armrest will be described below, but a similar apparatus and method may be used to manufacture other surface-layered parts. The up, down, left, right and other directions used when describing what is shown in the Figures will be based on the directions as seen in those Figures. However, where otherwise indicated particularly, that indication prevails.

Firstly, the armrest <NUM> to be produced by the manufacturing apparatus and method as an embodiment will be described. In one embodiment, the finished shape of the armrest <NUM> may be substantially the same as that of the armrest shown in <FIG>, as a conventional armrest. Therefore, the detailed configuration of the armrest <NUM> will again be described by way of <FIG>.

<FIG> is an exploded perspective view of the configuration of one end of an armrest <NUM>. As shown in <FIG>, the armrest <NUM> includes a base member <NUM> and a surface layer member <NUM>. The base member <NUM> dictates the general form of the armrest <NUM>, and is typically a flat rigid member made of polypropylene (PP). The surface layer member <NUM> is arranged on the front side <NUM> of the base member <NUM>, and covers the base member <NUM>. The surface layer member <NUM> is typically made of an olefin-based elastomer, and has a property of being capable of expanding and contracting to some extent. For the purpose of covering on the base member <NUM>, the surface layer member <NUM> is formed into a shape complementary to the shape of the base member <NUM>.

As shown in <FIG>, the armrest <NUM> of the present embodiment has a convex shape on the front side <NUM> of the base member <NUM>. The surface layer member <NUM> covers the front side <NUM> of the convex-shaped base member <NUM>. The edge <NUM> of the surface layer member <NUM> includes one or more wrapping portion <NUM>, which is configured to wrap a corresponding edge <NUM> of the base member <NUM>. The wrapping portion(s) <NUM> are fitted onto the edge(s) <NUM> of the base member <NUM>. The surface layer member <NUM> covers the front side <NUM> of the base member <NUM> when the wrapping portions <NUM> at two side edges <NUM> of the surface layer member <NUM> are fitted in a wrapping manner over the respective side edges <NUM> of the base member <NUM>.

In the present embodiment, as shown in <FIG> at the wrapping portion <NUM> on the right side, the base member <NUM> includes claws <NUM> on the edge <NUM> of the base member <NUM>, and the surface layer member <NUM> includes engagement holes <NUM> in these wrapping portions <NUM>. The engagement holes <NUM> in the wrapping portions <NUM> are hooked to the respective claws <NUM>, so that the surface layer member <NUM> is securely attached to the base member <NUM>.

<FIG> and <FIG> show an enlarged view of the engagement between a hooking tab 18A and an engagement hole <NUM>. In the present embodiment, the claw <NUM> includes a hooking tab 18A extending in the direction in which the wrapping portion <NUM> is moved when fitted onto the edge <NUM> of the base member <NUM>. That is, the hooking tab 18A extends right to left as seen in <FIG>. As a result, the engagement hole <NUM> of the wrapping portion <NUM> can only be engaged by the claw <NUM> once the engagement hole <NUM> goes beyond the hooking tab 18A. Therefore, the engagement ensures secure fastening of the wrapping portions <NUM>.

<FIG> shows a modified arrangement of the hooking tab 18A of the claw <NUM>. In this modification, the direction of the hooking tab 18A is perpendicular to the direction of fitting the wrapping portion <NUM>. This configuration may be adopted in the case where the wrapping portion <NUM> cannot be moved beyond the position shown in <FIG> when being fitted. This allows the wrapping portion <NUM> to be fitted by being laterally shifted (left to right as seen in <FIG>) even when the fitting movement of the wrapping portion <NUM> is limited.

The wrapping portion <NUM> of the edge <NUM> of the surface layer member <NUM> has a smaller width overlapping the edge <NUM> of the base member <NUM> in the portion where the claws <NUM> are located than in the portions with no claws <NUM>. This facilitates arrangement of the claws <NUM> and the engagement holes <NUM>.

The manufacturing apparatus <NUM> in one embodiment will now be described with reference to <FIG> shows a general configuration of the basic elements of the manufacturing apparatus <NUM> in a schematic way. The manufacturing apparatus <NUM> includes a workpiece supporting table <NUM>, a push-to-fit device <NUM>, and a clamp device <NUM>. The workpiece supporting table <NUM> is provided for placement of the workpieces for the armrest <NUM> to be produced. The clamp device <NUM> holds the workpieces for the armrest <NUM> against the workpiece supporting table <NUM>. The push-to-fit device <NUM> operates to fit the wrapping portion <NUM> of the surface layer member <NUM> onto the base member <NUM> for the armrest <NUM>.

The workpiece supporting table <NUM> is mounted on a base <NUM> of the manufacturing apparatus <NUM>. The supporting surface <NUM> of the workpiece supporting table <NUM> may be concaved for placement of an armrest <NUM> having a convex outer shape. The supporting surface <NUM> of the workpiece supporting table <NUM> may consist of a rigid member made of plastic. The base member <NUM>, with the surface layer member <NUM> layered on the lower side, is placed on the supporting surface <NUM> of the workpiece supporting table <NUM>. At this stage, the wrapping portion <NUM>, shown on the right side in <FIG>, is in an opened position that is disengaged from the edge <NUM> of the base member <NUM>. Accordingly, the wrapping portion <NUM>, shown on the right side in <FIG>, is not yet fitted onto the edge <NUM> of the base member <NUM>.

On the other hand, another wrapping portion <NUM>, shown on the left side in <FIG>, has already been fitted onto the corresponding edge <NUM> of the base member <NUM> when being placed on the workpiece supporting table <NUM>. This fitting can be performed by a machine, such as a robot, when placing the base member <NUM> and the surface layer member <NUM> on the workpiece supporting table <NUM>. Unlike the right one, the fitting of the left wrapping portion <NUM>, which does not include a claw <NUM>, onto the edge <NUM> of the wrapping portion <NUM> is easy when the right wrapping portion <NUM> is opened, and therefore may optionally be performed manually by hand.

<FIG> shows a specific configuration of the clamp device <NUM>. When the base member <NUM> and the surface layer member <NUM> are placed on the supporting surface <NUM> of the workpiece supporting table <NUM>, the clamp device <NUM> holds the base member <NUM> and the surface layer member <NUM> together against the supporting surface <NUM>. To achieve this, the clamp device <NUM> includes a clamping portion <NUM> at a distal end of the operating mechanism. The clamp device <NUM> fixes the base member <NUM>, from its back side, toward the supporting surface of the workpiece supporting table <NUM>, as shown in <FIG>. The clamp device <NUM> is a mechanism that is operated by a power cylinder (not shown).

The push-to-fit device <NUM> will now be described. As shown in <FIG>, the push-to-fit device <NUM> is configured to fit the wrapping portion <NUM> of the surface layer member <NUM> onto the edge <NUM> of the base member <NUM>. In the present embodiment, the push-to-fit device <NUM> is positioned so as to fit the wrapping portion <NUM> on the right side as seen in <FIG>.

<FIG> schematically shows the push-to-fit device <NUM> by the movement of a pushing portion <NUM> alone. The push-to-fit device <NUM> includes a pushing portion <NUM> configured to push the wrapping portion <NUM> of the edge <NUM> of the surface layer member <NUM>. The pushing portion <NUM> is moved by a movable member <NUM> in the direction of arrow X, from the position indicated by the solid lines to the position indicated by the two-dot-dashed lines. The direction of this movement is parallel to a surface of the edge <NUM> of the base member <NUM>, to which the wrapping portion <NUM> in the edge <NUM> of the surface layer member <NUM> is to be fitted.

The pushing portion <NUM> includes a rigid base member <NUM>. The pushing portion <NUM> also includes an elastic member <NUM> made of an elastic material. The elastic member <NUM> is formed on a surface of the base member <NUM>. The surface of the rigid base member <NUM> on which the elastic member <NUM> is formed may face forward in the pushing direction. The material of the elastic member <NUM> may be rubber, for example. The elastic member <NUM> extends downward beyond the lower end of the rigid base member <NUM>. As a result, the lower end of the pushing portion <NUM> pushes the wrapping portion <NUM> only by pressing the elastic member <NUM> against the surface of the wrapping portion <NUM>. This is done in a surface contact manner, that is, in a stroking manner.

The actuation of the movable member <NUM> of the push-to-fit device 34in the X direction causes the pushing portion <NUM> to move the wrapping portion <NUM> of the surface layer member <NUM> from the position shown by the solid lines in <FIG> to the position shown by the two-dot chain lines. During this movement, the engagement holes <NUM> in the wrapping portion <NUM> are hooked by the claw <NUM>, which is formed on the edge <NUM> of the base member <NUM>. Due to this hooking, the wrapping portion <NUM> of the surface layer member <NUM> is fitted onto the edge <NUM> of the base member <NUM>.

During the movement of the pushing portion <NUM> described above, the fitting of the wrapping portion <NUM> onto the edge <NUM> of the base member <NUM> is primarily effected by the rigid base member <NUM>. Additionally, the elastic member <NUM>, which extends downward from the base member <NUM>, moves in a stroking manner along the surface of the surface layer member <NUM>. The stroking movement of the elastic member <NUM> ensures a more reliable fastening to the claw 18due to the close contact with the surface of the surface layer member <NUM>. Additionally, this allows for fitting without damaging the surface layer member <NUM>.

<FIG> show a specific configuration of the push-to-fit device <NUM> around the pushing portions <NUM>. <FIG> is a perspective view of the pushing portions <NUM> viewed from the rearward side of the pushing direction, while <FIG> is a perspective view of the pushing portions <NUM> viewed from the forward side in the pushing direction. The push-to-fit device <NUM> may be configured as a mechanism in which the shown pushing portions <NUM> are moved by two air cylinders (not shown).

<FIG> shows an enlarged view of the pushing portion <NUM> of the push-to-fit device <NUM> shown in <FIG>. The pushing portion <NUM> is attached to a movable body via a connecting member <NUM>. The movable body corresponds to the movable member <NUM> shown in <FIG>. The connecting member <NUM> and the movable body are fixed to one another by one or more bolts <NUM>. The connecting member <NUM> and the base member <NUM> of the pushing portion <NUM> are fixed to one another by one or more bolts <NUM>. The pushing portion <NUM> includes an elastic member <NUM> made of an elastic material. The elastic member <NUM> may be formed on a surface of the base member <NUM> on its forward side, on a side in the direction of movement. The elastic member <NUM> extends downward beyond the lower end of the base member <NUM>.

As shown by phantom lines (the two-dot dashed lines) in <FIG>, when the pushing portion <NUM> pushes the wrapping portion <NUM> of the surface layer member <NUM>, the base member <NUM> pushes the elastic member <NUM>. Accordingly, the wrapping portion <NUM> is pushed by the elastic member <NUM>, which extends downward from the base member <NUM>, in a stroking manner. The wrapping portion <NUM> is pushed softly, and therefore is not easily scratched. In addition, little noise occurs due to the pushing, thereby reducing the whole working noise.

One embodiment of a manufacturing method using the above described manufacturing apparatus <NUM> will now be described.

The base member <NUM> and the surface layer member <NUM> are prepared in advance in a specified shape. As described above referring to the manufacturing apparatus, the base member <NUM> is a rigid member made of polypropylene (PP). The surface layer member <NUM> is formed of an olefin-based elastomer, and has a property of being capable of expanding and contracting to some extent.

The first step will now be described. As shown in <FIG>, the base member <NUM> and the surface layer member <NUM>, which were prepared in the specified shape in the preparatory step, are placed on the supporting surface <NUM> of the workpiece supporting table <NUM> of the manufacturing apparatus <NUM>. They are arranged such that they are layered over each other. To place them on the supporting surface <NUM> in such a layered position, the surface layer member <NUM> may first be placed on the supporting surface <NUM>, and the base member <NUM> may then be placed on top of the surface layer member <NUM>. The surface layer member <NUM> and the base member <NUM> placed in such a layering manner on the workpiece supporting table <NUM> are then pressed by the clamping portions <NUM> of the clamp device <NUM>. Accordingly, their position may be fixed.

After the first step, the wrapping portion <NUM>, shown on the right side in <FIG>, is in an opened position, such that it is away from the edge <NUM> of the base member <NUM>. That is, the right wrapping portion <NUM> is not yet fitted on the edge <NUM> of the base member <NUM> when first placed on the workpiece supporting table <NUM>.

However, in the present embodiment, the other wrapping portion <NUM>, shown on the left side in <FIG>, has already been fitted on the corresponding edge <NUM> of the base member <NUM> when placed on the workpiece supporting table <NUM> by the first step. This fitting may be performed by a machine, such as a robot, or manually by hand, as described above referring to the manufacturing apparatus <NUM>.

The second step will now be described. The second step includes fitting the wrapping portion <NUM>, shown on the right side in <FIG>, onto the base member <NUM> by the push-to-fit device <NUM>. As this second step is explained with reference to <FIG>, the push-to-fit device <NUM> will operate to fit the wrapping portion <NUM>, shown on the right side in <FIG>, onto the edge <NUM> of the base member <NUM>, thereby assembling the surface layer member <NUM> with the base member <NUM>.

The fitting operation of the wrapping portion <NUM> by the push-to-fit device <NUM> is effected by the pushing operation of the pushing portion <NUM>. This pushing operation is performed by the elastic member <NUM>, which extends beyond the lower ends of the base member <NUM> of the pushing portion <NUM>, stroking the surface of the wrapping portion <NUM>. This allows for a smooth fitting operation.

The wrapping portion <NUM>, on the right side as seen in <FIG>, is fastened by engagement of the claw <NUM> with the engagement hole <NUM>. The engagement hole <NUM> of the wrapping portion <NUM> is hooked by the hooking tab 18A of the claw <NUM>. This is done as the pushing portion <NUM> strokes the surface of the wrapping portion <NUM>, as described above. This hooking prevents the wrapping portion <NUM> from being easily disengaged from the hooking tab 18A because the hooking tab 18A extends to the left as seen in <FIG> while the wrapping portion <NUM> is biased to the right due to its own elasticity. Accordingly, the wrapping portion <NUM> is fastened to the base member <NUM> with little possibility of being detached from the base member <NUM>.

In the present embodiment, the direction of movement of the pushing portion <NUM> of the push-to-fit device <NUM> is parallel to a surface of the edge <NUM> of the base member <NUM> onto which the wrapping portion <NUM> formed in the edge <NUM> of the surface layer member <NUM> is to be fitted. This allows the pushing operation of the wrapping portion <NUM> by the pushing portion <NUM> to be smoother.

The armrest <NUM>, manufactured as the product produced through the above steps, is released from the clamping portion <NUM> of the clamp device <NUM> and taken out of the manufacturing device <NUM> by a robot or other machine. The manufacturing process is thus completed.

The apparatus and method of manufacturing the armrest <NUM> of the embodiments described above enable mechanical fitting of a wrapping portion <NUM> of a surface layer member <NUM> onto an edge <NUM> of a base member <NUM>. Productivity can thus be improved, as compared with manual fitting by hand. Additionally, when the product is mass produced, variations in quality can be stabilized.

In the case of the above configuration, when the wrapping portion <NUM> of the surface layer member <NUM> is fitted on the edge <NUM> of the base member <NUM>, the claws <NUM> formed on the base member <NUM> are locked in the corresponding engagement holes <NUM> formed in the wrapping portion <NUM>, the surface layer member <NUM> can be reliably assembled with the base member <NUM>.

Further embodiments will be described below.

In the above embodiment, the surface-layered part has been described as an armrest of an automobile. In another embodiment, the above-mentioned manufacturing apparatus and method can be widely applied to any part with a structure in which a wrapping portion formed on the surface layer member is fitted to an edge of a base member when the surface layer member is attached to the base member. For example, the apparatus and method can be applied to an article of furniture (e.g. armrests of a chair) or an exterior part of a cosmetics box.

While the armrest <NUM> of the above embodiment is convex on the front side <NUM> of the base member <NUM>, the surface-layered part may be convex on the opposite side, that is, it may be concave on the front side <NUM> of the base member <NUM>. The surface-layered part that is not an armrest <NUM> may have an L-shaped cross-section.

In the above embodiment, the surface layer member <NUM> includes the engagement hole <NUM> in the wrapping portion <NUM>, and the engagement hole <NUM> is hooked on the claw <NUM> formed on the edge <NUM> of the base member <NUM>. However, the engagement hole <NUM> and the claw <NUM> may not be included, so that the wrapping portion <NUM> of the surface layer member <NUM> is simply fitted onto the edge <NUM> of the base member <NUM>. The wrapping portion <NUM> shown on the left side in <FIG> may be mechanically fitted onto the edge <NUM> of the base member <NUM> by another push-to-fit device <NUM>.

While the material for the base member <NUM> of the above embodiment has been described as polypropylene (PP), the base member <NUM> may be made of various thermoplastics other than PP, having a higher rigidity than the surface layer member <NUM>, or a press-formed steel sheet.

The surface layer member <NUM> may be made of not only various thermoplastics such as soft polyvinyl chloride, styrene, olefin, and polyester, but may also be made of various other skin materials, including elastic woven and non-woven fabrics, knitted fabrics, synthetic leathers, natural leathers, and soft films.

While rubber was mentioned as an example of the material for the elastic member <NUM>, an elastomer or a thin sheet of metal, such as stainless steel, may also be used.

The above embodiments may have the following advantages.

In some embodiments, a base member, with a surface layer member layered on its lower side, may be placed on the workpiece supporting table, wherein a wrapping portion formed at the edge of the surface layer member is in the opened position, where the wrapping portion is disengaged from the edge of the base member. A push-to-fit device then pushes the wrapping portion in the direction fitting it onto the edge of the base member. This automated mechanical fitting of the wrapping portion onto the edge of the base member improves the manufacturing productivity of the surface layered part. Furthermore, the quality of mass produced surface-layered parts is consistent.

In some embodiments, the push-to-fit device includes a pushing portion that pushes the wrapping portion. The pushing portion includes a rigid base member and a member made of elastic material on a surface of the rigid base member on the forward side in the pushing direction. The push-to-fit device fits the wrapping portion of the surface layer member onto the edge of the base member with the elastic member in contact with the wrapping portion, thereby preventing or suppressing the surface layer member from being damaged.

In some embodiments, the elastic member on a surface of the rigid base member on the forward side in the pushing direction extends beyond the lower end of the base member. As a result, the extended elastic member pushes the wrapping portion of the surface layer member in a stroking manner, so as to fit it onto the edge of the base member. This allows for a smooth fitting action.

In some embodiments, the direction of movement of the pushing portion of the push-to-fit device is parallel to a surface of the edge of the base member, the surface onto which the wrapping portion is fitted. This configuration allows for a more efficient operation of fitting the wrapping portion of the surface layer member onto the edge of the base member.

Claim 1:
An apparatus (<NUM>) for manufacturing a surface-layered part, wherein the surface-layered part comprises a base member (<NUM>) assembled with a surface layer member (<NUM>), wherein a front side (<NUM>) of the flat base member (<NUM>) is covered by the surface layer member (<NUM>), and a wrapping portion (<NUM>) formed at an edge (<NUM>) of the surface layer member (<NUM>) is configured to be fitted onto an edge (<NUM>) of the base member (<NUM>), the apparatus (<NUM>) comprising:
a workpiece supporting table (<NUM>) on which the base member (<NUM>) and the surface layer member (<NUM>) are placed such that the surface layer member (<NUM>) is layered with the base member (<NUM>), and
a push-to-fit device (<NUM>) configured to push the wrapping portion (<NUM>) formed at the edge (<NUM>) of the surface layer member (<NUM>) in a direction to fit the wrapping portion (<NUM>) onto the edge (<NUM>) of the base member (<NUM>) from an opened position in which the wrapping portion (<NUM>) is away from the edge (<NUM>) of the base member (<NUM>), the push-to-fit device (<NUM>) comprises a pushing portion (<NUM>) configured to push the wrapping portion (<NUM>) formed at the edge (<NUM>) of the surface layer member (<NUM>), the pushing portion (<NUM>) comprises a rigid base member (<NUM>), characterised in that the pushing portion (<NUM>) comprises an elastic member (<NUM>) formed on a surface of the rigid base member (<NUM>).