Patent Description:
For example, when manufacturing a structure employed in an aircraft, one of the schemes to apply strength to a long thermoplastic composite material is to press the thermoplastic composite material and another thermoplastic composite material as a reinforcing member while welding resins together contained therein and thereby weld these thermoplastic composite materials (co-consolidation) (<CIT>).

Further, <CIT> discloses a welding device for welding thermoplastic materials comprising a welding layer, a heating layer and a transmission layer arranged between the heating layer and the welding layer. The welding layer has a thermal conductivity greater than <NUM> W/mk.

Another example of a welding device of the thermal impulse type for the heat sealing of superposed materials is described in <CIT>.

<CIT> describes a welding device and related method which represents the closest prior art.

Conventionally, heating required for welding of thermoplastic resins is performed by using a metal plate or the like having a built-in electric heater.

In such a case, the metal plate can serve as a useless heat capacity body, and this will require longer time for rise and fall of the temperature and also lead to waste of energy (electric power).

The present disclosure has been made in view of such circumstances, and an object is to provide a welding device that can realize efficient welding in terms of time and realize efficient welding in terms of energy (electric power).

This object is solved by a welding device with the features of claims <NUM>, <NUM> or <NUM>, and a welding method with the features of claim <NUM>. Preferred embodiments follow form the other claims. To achieve the above object, the welding device and the welding method of the present disclosure employ the following solutions.

That is, a welding device according to one aspect of the present disclosure is a welding device for welding stacked materials to each other that contain a thermoplastic resin, the welding device includes: a heating unit configured to come into contact with each of the materials; and a mold configured to interpose the heating unit between each of the materials and the mold, the heating unit has a sheet-like heat generating body configured to generate heat by electric power, insulating layers, and a contact layer and is configured such that a structure in which the heat generating body is interposed between the insulating layers is laminated on the contact layer, and the contact layer has thermal conductivity of <NUM> W/m×K or greater at normal temperature and Young's modulus of <NUM> GPa or greater at normal temperature.

Further, a welding method according to one aspect of the present disclosure is a welding method for welding the materials to each other by the welding device described above, and the welding method includes: causing the heat generating body of the heating unit to generate heat; and pushing the mold to the material side.

According to the present disclosure, efficient welding in terms of time can be realized, and efficient welding in terms of energy (electric power) can be realized.

One embodiment of the present disclosure will be described below with reference to the drawings.

As illustrated in <FIG>, the welding device <NUM> is a device for performing co-consolidation (hereafter, also simply referred to as "welding") on a first member <NUM> and a second member <NUM>.

The first member <NUM> is a material containing a thermoplastic resin, specifically, which is a thermoplastic composite material such as fiber reinforced resin containing a thermoplastic resin (for example, CFRP or GFRP).

For example, the first member <NUM> has a plate-like web <NUM> and plate-like flanges (side walls) <NUM> arranged vertically in the height direction from respective two opposing sides of the web <NUM> and has a C-shaped or hat-shaped cross-sectional shape.

The first member <NUM> is a long member formed such that, when the dimension in the width direction (the direction in which the flanges <NUM> face each other) is defined as <NUM>, the dimension in the longitudinal direction (the direction in which the web <NUM> and the flanges <NUM> extend) is <NUM> or greater.

For example, when the dimension in the width direction is <NUM>, the dimension in the longitudinal direction will be <NUM> or longer. Note that these numerical values are mere examples.

The second member <NUM> is a material containing a thermoplastic resin, specifically, which is a thermoplastic composite material such as fiber reinforced resin containing a thermoplastic resin (for example, CFRP or GFRP).

For example, the second member <NUM> has a plate-like web <NUM> and plate-like flanges (side walls) <NUM> arranged vertically in the height direction from respective two opposing sides of the web <NUM> and has a C-shaped or hat-shaped cross-sectional shape.

The second member <NUM> is a long member formed such that, when the dimension in the width direction (the direction in which the flanges <NUM> face each other) is defined as <NUM>, the dimension in the longitudinal direction (the direction in which the web <NUM> and the flanges <NUM> extend) is <NUM> or greater.

The first member <NUM> and the second member <NUM> are arranged in a state where the web <NUM> and the web <NUM> are stacked on each other and the outer circumferential faces thereof are in contact with each other and where each end of the flanges <NUM> and each end of the flanges <NUM> face opposite sides.

The welding device <NUM> welds the web <NUM> and the web <NUM> to each other in the first member <NUM> and the second member <NUM> arranged in such a way.

Note that each flange <NUM> is not an essential configuration in the first member <NUM> with which the web <NUM> is welded. The same applies to each flange <NUM> of the second member <NUM>.

Further, the shapes of the first member <NUM> and the second member <NUM> described above are examples, and any shapes of the first member <NUM> and the second member <NUM> may be employed as long as these shapes are in a form in which plate-like portions stacked on each other are joined together.

As illustrated in <FIG> and <FIG>, the welding device <NUM> includes a first unit having a first graphite heater (heating unit) <NUM> and a first die (mold) <NUM> and a second unit having a second graphite heater (heating unit) <NUM> and a second die (mold) <NUM>.

The first member <NUM> and the second member <NUM> are stacked on each other and interposed between the first unit and the second unit.

In this state, the first unit is in a form such that the first unit is contained inside between the flanges <NUM> of the first member <NUM>, and the second unit is in a form such that the second unit is contained inside between the flanges <NUM> of the second member <NUM>.

Accordingly, the first member <NUM> and the second member <NUM> can be pressed by the first unit and the second unit.

The first unit and the second unit are arranged symmetrically about the interface between the first member <NUM> and the second member <NUM> (the joining interface in welding).

The first unit is a unit arranged below the first member <NUM> and the second member <NUM> and has the first graphite heater <NUM> and the first die <NUM>.

The first die <NUM> is a long metal block extending in the longitudinal direction of the first member <NUM>.

The first graphite heater <NUM> is provided to the first die <NUM> so that a heat insulation material <NUM> is interposed between the first die <NUM> and the first graphite heater <NUM>.

The first graphite heater <NUM> is a device that heats the first member <NUM>. The configuration of the first graphite heater <NUM> will be described later.

The top face of the first graphite heater <NUM> is a surface that comes into contact with the web <NUM> of the first member <NUM>.

The second unit is arranged symmetrically with the first unit about the joining interface, and the under face of the second graphite heater <NUM> is a surface that comes into contact with the web <NUM> of the second member <NUM>, as already described. That is, the second unit and the like are arranged in a form such that the first unit and the first member <NUM> are vertically inversed with respect to the joining interface. Thus, the detailed description for the second unit will be omitted.

Note that the second graphite heater <NUM>, the second die <NUM>, and a heat insulation material <NUM> of the second unit correspond to the first graphite heater <NUM>, the first die <NUM>, and the heat insulation material <NUM> of the first unit.

The welding device <NUM> includes the first graphite heater <NUM> and the second graphite heater <NUM> as devices for heating the first member <NUM> and the second member <NUM>.

The configuration of the first graphite heater <NUM> and the second graphite heater <NUM> will be described below.

As illustrated in <FIG>, the first graphite heater <NUM> is configured such that a graphite sheet (heat generating body) <NUM>, two insulating materials (insulating layers) <NUM>, an inner cover (contact layer) <NUM>, and an outer cover (contact layer) <NUM> are laminated in layers.

The graphite sheet <NUM> is a sheet-like heat generating body that generates heat by electric power. The electric power supplied to the graphite sheet <NUM>, that is, the heating value of the graphite sheet <NUM> is controlled by a control unit (not illustrate).

Note that the heat generating body is not limited to the graphite sheet <NUM> and may be any sheet-like body that generates heat by electric power.

The graphite sheet <NUM> is interposed and held between the two insulating materials <NUM>.

The insulating materials <NUM> are members for electrical insulation between the graphite sheet <NUM> and the outer cover <NUM> and between the graphite sheet and the inner cover <NUM>. The resistance of the insulating material <NUM> is <NUM> MΩ or higher at normal temperature.

The structure in which the graphite sheet <NUM> is interposed between the insulating materials <NUM> is interposed and held between the outer cover <NUM> and the inner cover <NUM>.

The outer cover <NUM> is a plate whose cross-sectional shape is a C-shape and whose side plates cover the sides of the structure in which the graphite sheet <NUM> is interposed between the insulating materials <NUM> and the sides of the inner cover <NUM>. Further, the outer cover <NUM> is also a portion that comes into contact with the first member <NUM> as the first graphite heater <NUM>.

A material having good thermal conductive property and predetermined rigidity is employed for the material of the outer cover <NUM>. An example of a physical property for evaluating the thermal conductive property may be thermal conductivity, which is preferably <NUM> W/m×K or greater at normal temperature in the present embodiment. Further, an example of a physical property for evaluating the rigidity is Young's modulus, which is preferably <NUM> GPa or greater in the present embodiment. An example of such a material may be a copper-based metal, high-thermal conductivity fine ceramics such as aluminum nitride or silicon carbide, or the like but is not limited thereto.

The inner cover <NUM> is a flat plate. Further, the inner cover <NUM> is also a portion that comes into contact with the heat insulation material <NUM> as the first graphite heater <NUM>.

A material satisfying the same physical properties as the outer cover <NUM> is employed for the material of the inner cover <NUM>. Note that these materials are not necessarily required to be the same material as long as they satisfy the above physical property.

In the first graphite heater <NUM> configured as described above, the side plates of the outer cover <NUM> cover the sides of the heat insulation material <NUM> and the first die <NUM>. In this state, a heat insulation material <NUM> may be provided between each side plate of the outer cover <NUM> and the heat insulation material <NUM> and between each side plate of the outer cover <NUM> and the first die <NUM>.

In the first graphite heater <NUM>, the total thickness of a portion of the laminated graphite sheet <NUM>, two insulating materials <NUM>, inner cover <NUM>, and outer cover <NUM> is about <NUM> or less.

Further, when each element forming the first graphite heater <NUM> is focused on in detail, it is preferable that the thickness of the graphite sheet <NUM> be <NUM> or less, the thickness of the insulating material <NUM> be <NUM> or less, and each thickness of the inner cover <NUM> and the outer cover <NUM> be <NUM> or less.

Note that, instead of the graphite sheet <NUM>, a different sheet-like heat generating body may be employed. An example of such a different heat generating body may be a metal thin-film heater or a micro ceramic heater.

Further, the inner cover <NUM> may be omitted from the first graphite heater <NUM>. In contrast, the outer cover <NUM> is essential for ensuring accuracy as a contact face to the first member <NUM>.

The second graphite heater <NUM> is configured such that a graphite sheet <NUM>, two insulating materials (insulating layers) <NUM>, an inner cover (contact layer) <NUM>, and an outer cover (contact layer) <NUM> are laminated in layers.

These components correspond to the graphite sheet <NUM>, the insulating materials <NUM>, the inner cover <NUM>, and the outer cover <NUM> of the first graphite heater <NUM>, and the second graphite heater <NUM> employs the same configuration as the first graphite heater <NUM>. Thus, the detailed description for the second graphite heater <NUM> will be omitted.

The second graphite heater <NUM> configured as described above is provided such that the side plates of the outer cover <NUM> cover the sides of the heat insulation material <NUM> and the second die <NUM>.

In this state, a heat insulation material <NUM> may be provided between each side plate of the outer cover <NUM> and the heat insulation material <NUM> and between each side plate of the outer cover <NUM> and second die <NUM>.

As illustrated in <FIG> and <FIG> to <FIG>, the welding device <NUM> may include inline plates <NUM>.

The inline plates <NUM> are plates attached to both end faces in the longitudinal direction of the first die <NUM>.

The inline plates <NUM> are fastened to the end faces in the longitudinal direction of the first die <NUM> by bolts <NUM>, for example.

As illustrated in <FIG>, the inline plate <NUM> is configured such that a plate <NUM>, a heat insulation material <NUM>, and a plate <NUM> are laminated.

As the material of the plate <NUM> and the plate <NUM>, a material having high strength and heat resistance is employed. An example of such a material may be a metal such as iron.

As illustrated in <FIG>, in a state where the inline plates <NUM> are attached to the first die <NUM>, the surface (end contact face) 171a of each plate <NUM> abuts against the end faces in the longitudinal direction of the first member <NUM> and the second member <NUM> and determines the position in the longitudinal direction of the first member <NUM> and the second member <NUM>. Note that, in <FIG>, only the first member <NUM> and the second member <NUM> are hatched for the purpose of illustration.

Accordingly, even when the melted resin causes a state where the stacked first member <NUM> and second member <NUM> are likely to be displaced relative to each other, such displacement can be prevented.

Note that the inline plate <NUM> may abut against the end faces of the first graphite heater <NUM> and the second graphite heater <NUM> in addition to the first member <NUM> and the second member <NUM>.

It is preferable to make the plate <NUM> as thin as possible within a range where it is possible to ensure sufficient strength to prevent deformation even when the plate <NUM> comes into contact with the first member <NUM> and the second member <NUM>. This can reduce the volume of the plate <NUM> that serves as a heat capacity body.

On the other hand, the plate <NUM> is not required to be thin as with the plate <NUM> if the heat insulation material <NUM> as a heat insulation layer is provided between the plates <NUM> and <NUM>. The plate <NUM> may rather be thicker than the plate <NUM> in order to ensure the rigidity as a function of the inline plate <NUM>.

As illustrated in <FIG>, the inline plate <NUM> is fastened to the first die <NUM> but not fastened to the second die <NUM>. Instead, a slot <NUM> extending in the height direction (see <FIG>) of the welding device <NUM> is formed in the upper part of the inline plate <NUM> (at a position overlapping the second die <NUM>). A pin <NUM> fixed to the second die <NUM> is inserted through the slot <NUM>. There is a play in the height direction but no play in the width direction between the slot <NUM> and the pin <NUM>.

With this configuration, the second die <NUM> is positioned in the width direction with respect to the first die <NUM> via the inline plate <NUM>, and the second die <NUM> is movable within a range of the slot <NUM> in the height direction with respect to the first die <NUM>.

The reason why the second die <NUM> is made movable is to ensure a motion margin needed for pushing the second die <NUM> to the first die <NUM> side when pressing the first member <NUM> and the second member <NUM>.

Note that the inline plate <NUM> is not necessarily required to be fastened to the first die <NUM> and may be fastened to the base plate <NUM> as long as the first die <NUM> and the base plate <NUM> are fixed to each other, for example.

As illustrated in <FIG>, <FIG>, and <FIG>, the welding device <NUM> may include side blocks <NUM>.

Each side block <NUM> is a plate extending in the longitudinal direction of the welding device <NUM>.

The side block <NUM> is attached to posts <NUM> erected on the base plate <NUM> so as to be located on both sides of the flange <NUM> of the first member <NUM> and the flange <NUM> of the second member <NUM>.

As illustrated in <FIG>, the side block <NUM> is configured such that a plate <NUM>, a heat insulation material <NUM>, and a plate <NUM> are laminated.

As illustrated in <FIG> and <FIG>, in a state where the side block <NUM> is attached to the posts <NUM>, the surface (side contact face) 181a of each plate <NUM> abuts against the side faces of the flange <NUM> of the first member <NUM> and the flange <NUM> of the second member <NUM> and determines the position in the width direction of the first member <NUM> and the second member <NUM>.

On the other hand, the plate <NUM> is not required to be thin as with the plate <NUM> if the heat insulation material <NUM> as a heat insulation layer is provided between the plates <NUM> and <NUM>. The plate <NUM> may rather be thicker than the plate <NUM> in order to ensure the rigidity as a function of the side block <NUM>.

As illustrated in <FIG>, the welding device <NUM> may include plungers <NUM> and <NUM>.

Each plunger <NUM> is a member that can push the flange <NUM> of the first member <NUM> in a direction away from the first die <NUM> in the width direction. For example, the plunger <NUM> is a component having a spring as an elastic body.

For example, the plunger <NUM> may be provided to the side face of the outer cover <NUM> covering the side of the first die <NUM> or may be provided to the side face of the first die <NUM>.

Accordingly, even when the melted resin causes a state where the flange <NUM> is likely to incline toward the first die <NUM>, such inclination can be prevented.

Note that, since the plunger <NUM> is provided on the second die <NUM> side but employs the same configuration as the plunger <NUM>, the detailed description for the plunger <NUM> will be omitted.

The welding device <NUM> configured as described above welds the first member <NUM> and the second member <NUM> as follows.

That is, first, as illustrated in <FIG> and <FIG>, the first member <NUM> and the second member <NUM> are set in the welding device <NUM> so that the web <NUM> of the first member <NUM> and the web <NUM> of the second member <NUM> are stacked on each other and the outer faces thereof come into contact with each other.

In this step, the inline plates <NUM>, the side blocks <NUM>, and the plungers <NUM> and <NUM> may be provided.

Next, the first graphite heater <NUM> and the second graphite heater <NUM> are caused to generate heat. In detail, electric power is supplied to the graphite sheet <NUM> and the graphite sheet <NUM> to cause the graphite sheet <NUM> and the graphite sheet <NUM> to generate heat.

Further, to consolidate the melted thermoplastic resin, the second die <NUM> is pushed against the first die <NUM> side to press the first member <NUM> and the second member <NUM>.

The first member <NUM> and the second member <NUM> are then cooled, and thereby the first member <NUM> and the second member <NUM> are integrated.

According to the present embodiment, the following advantageous effects are achieved.

Since the first graphite heater <NUM> is configured such that the structure in which the graphite sheet <NUM> is interposed between the insulating materials <NUM> is interposed between the outer cover <NUM> and the inner cover <NUM>, the heat capacity body surrounding the graphite sheet <NUM> as a heat generating body can be made compact.

This eliminates the need for heating a useless heat capacity body. Thus, a time required for rise and fall of the temperature is shortened, thereby efficient welding in terms of time can be realized, and efficient welding in terms of energy (electric power) can be realized. The same applies to the second graphite heater <NUM>.

Further, if the heat insulation material <NUM> and the heat insulation material <NUM> are provided, the amount of heat transferred from the first graphite heater <NUM> to the first die <NUM> and the amount of heat transferred from the second graphite heater <NUM> to the second die <NUM> can be suppressed.

Accordingly, the heat from the first graphite heater <NUM> and the second graphite heater <NUM> can be efficiently and intensively transferred to the first member <NUM> and the second member <NUM> (welding portion).

Further, if the inline plate <NUM> is provided, even when the melted resin causes a state where the stacked first member <NUM> and second member <NUM> are likely to be displaced relative to each other in the longitudinal direction, such displacement can be prevented.

Further, if the inline plate <NUM> has the heat insulation material <NUM>, heat dissipation via the inline plate <NUM> from the end faces of the first member <NUM> and the second member <NUM>, the end faces of the first graphite heater <NUM> and the second graphite heater <NUM>, and the end faces of the first die <NUM> and the second die <NUM> can be suppressed.

Further, if the side block <NUM> is provided, even when the melted resin causes a state where the stacked first member <NUM> and second member <NUM> are likely to be displaced relative to each other in the width direction, such displacement can be prevented.

Further, if the side block <NUM> has the heat insulation material <NUM>, heat dissipation via the side block <NUM> from the side faces of the first member <NUM> and the second member <NUM> can be suppressed.

Further, if the plungers <NUM>, <NUM> are provided, even when the melted resin causes a state where the flanges <NUM>, <NUM> are likely to incline inward, such inclination can be prevented.

Note that a welding step automated by a robot may be implemented by attaching the first unit having the first graphite heater <NUM> and the first die <NUM> and the second unit having the second graphite heater <NUM> and the second die <NUM> to gripping parts of robot arms, respectively. Such a robot is incorporated in a production line of a structure employed by an aircraft, for example.

One embodiment as described above is recognized as follows, for example.

That is, a welding device (<NUM>) according to one aspect of the present disclosure is a welding device for welding stacked materials (<NUM>, <NUM>) to each other that contain a thermoplastic resin, the welding device includes: a heating unit (<NUM>, <NUM>) configured to come into contact with each material; and a mold (<NUM>, <NUM>) configured to interpose the heating unit between the material and the mold, the heating unit has a graphite sheet (<NUM>, <NUM>) configured to generate heat by electric power, insulating layers (<NUM>, <NUM>), and a contact layer (<NUM>, <NUM>) and is configured such that a structure in which the graphite sheet is interposed between the insulating layers is laminated on the contact layer, and the contact layer has thermal conductivity of <NUM> W/m×K or greater at normal temperature and Young's modulus of <NUM> GPa or greater at normal temperature.

According to the welding device of the present aspect, since the heating unit configured to come into contact with each material containing the thermoplastic resin and the mold configured to interpose the heating unit between the material and the mold are provided, the heating unit has the graphite sheet configured to generate heat by electric power, the insulating layers, and the contact layer and is configured such that the structure in which the graphite sheet is interposed between the insulating layers is laminated on the contact layer, and the contact layer has thermal conductivity of <NUM> W/m×K or greater at normal temperature and Young's modulus of <NUM> GPa or greater at normal temperature, the heat capacity body of the heating unit surrounding the graphite sheet as a heat generating body can be made compact.

This eliminates the need for heating a useless heat capacity body. Thus, a time required for rise and fall of the temperature is shortened, thereby efficient welding in terms of time can be realized, and efficient welding in terms of energy (electric power) can be realized.

Further, the welding device according to one aspect of the present disclosure includes a heat insulation material (<NUM>, <NUM>) provided between the heating unit and the mold.

According to the welding device of the present aspect, since the heat insulation material provided between the heating unit and the mold is provided, the amount of heat transferred from the heating unit to the mold can be suppressed.

Accordingly, the heat from the heating unit can be efficiently and intensively transferred to the material (welding portion).

Further, the welding device according to one aspect of the present disclosure includes an inline plate (<NUM>) having an end contact face (171a) configured to abut against end faces of the materials.

According to the welding device of the present aspect, since the inline plate having the end contact face configured to abut against the end faces of the materials is provided, the materials can be positioned.

Accordingly, even when the melted resin causes a state where the stacked materials are likely to be displaced relative to each other, such displacement can be prevented.

Further, in the welding device according to one aspect of the present disclosure, the inline plate has a plate (<NUM>) forming the end contact face and a second heat insulation material (<NUM>) laminated on the plate.

According to the welding device of the present aspect, since the inline plate has the plate forming the end contact face and the second heat insulation material laminated on the plate, the heat dissipation via the inline plate from the end face of the material, the end face of the heating unit, and/or the end face of the mold can be suppressed.

Further, the welding device according to one aspect of the present disclosure includes a side block (<NUM>) having a side contact face (181a) configured to abut against side faces of the materials.

According to the welding device of the present aspect, since the side block having the side contact face configured to abut against the side faces of the materials is provided, the materials can be positioned.

Further, in the welding device according to one aspect of the present disclosure, the side block (<NUM>) has a plate (<NUM>) forming the side contact face and a third heat insulation material (<NUM>) laminated on the plate.

According to the welding device of the present aspect, since the plate forming the side contact face and the third heat insulation material laminated on the plate are provided, the heat dissipation via the side block from the side face of the material can be suppressed.

Further, in the welding device according to one aspect of the present disclosure, the material has a side wall (<NUM>, <NUM>) arranged vertically so as to cover a side of the mold, and the welding device further includes a pushing member (<NUM>, <NUM>) configured to push the side wall of the material in a direction away from the mold.

According to the welding device of the present aspect, since the material has the side wall arranged vertically so as to cover a side of the mold, and the pushing member configured to push the side wall of the material in a direction away from the mold is provided, even when the melted resin causes a state where the side wall is likely to incline toward the mold, such inclination can be prevented.

Claim 1:
A welding device for welding stacked materials (<NUM>, <NUM>) to each other that contain a thermoplastic resin, the welding device comprising:
heating units (<NUM>, <NUM>) configured to come into contact with each of the materials (<NUM>, <NUM>); and
a mold (<NUM>, <NUM>) configured to interpose the heating units (<NUM>, <NUM>) between each of the materials (<NUM>, <NUM>) and the mold (<NUM>, <NUM>),
wherein the heating units (<NUM>, <NUM>) have a sheet-like heat generating body (<NUM>, <NUM>) configured to generate heat by electric power and insulating layers (<NUM>, <NUM>),
characterized in that
the heating units (<NUM>, <NUM>) further comprise a contact layer (<NUM>, <NUM>) and is configured such that a structure in which the heat generating body (<NUM>, <NUM>) is interposed between the insulating layers (<NUM>, <NUM>) is laminated on the contact layer (<NUM>, <NUM>), and
wherein the contact layer (<NUM>, <NUM>) has thermal conductivity of <NUM> W/m×K or greater at normal temperature and Young's modulus of <NUM> GPa or greater at normal temperature;
wherein the welding device further comprises an inline plate (<NUM>) having an end contact face (171a) configured to abut against end faces of the materials (<NUM>, <NUM>).