Patent Application
20230131411
The present disclosure relates to a forming jig and a forming method.
In the related art, a device for forming a composite material having an Ω-shaped cross-section is known (refer to PTL 1, for example). In the case of the device, a composite material that is a flat plate-shaped laminate is installed on a forming tool and the center of the composite material is pressed toward the forming tool by means of a pad in a state where both sides of the composite material are restricted so that forming is performed.
Meanwhile, as the forming of a laminate such as a composite material, there is a case of forming a laminate into a three-dimensional shape that extends in a longitudinal direction, of which the cross-section cut along a plane orthogonal to the longitudinal direction has an Ω-like shape, and that has a bent portion in the longitudinal direction. In a case where a composite material is formed into a three-dimensional shape by using a forming jig in which a male die and a female die are used, the composite material on both sides of a bent portion to be formed in the longitudinal direction abuts the female die and the composite material at the bent portion to be formed abuts the male die when the composite material is installed on the female die. When the male die is pressed against the female die in this state, a portion of the composite material that abuts the female die enters a state of being restricted and a reinforced fiber included in the composite material is sent in surplus, which may cause a wrinkle and cause a forming failure.
Therefore, an object of the present disclosure is to provide a forming jig and a forming method with which it is possible to suppress occurrence of a forming failure even in a case of forming a laminate into a three-dimensional shape.
According to an aspect of the present disclosure, there is provided a forming jig forming a laminate into a three-dimensional shape that extends in a longitudinal direction, that has a cross-sectional shape including curved portions in a cross-section cut along a plane orthogonal to the longitudinal direction, and that includes a bent portion in the longitudinal direction, the laminate being obtained by laminating reinforced fiber sheets, the forming jig including a female die that includes a female-side forming surface for forming the bent portion, a male die that is fitted to the female die with the laminate interposed therebetween and that includes a male-side forming surface for forming the bent portion, and a support member having extensibility that is provided between the female die and the laminate at a time of forming and that supports the laminate in a state where the laminate is separated from the female die. The laminate abuts the male die on both sides of the bent portion to be formed in the longitudinal direction at the time of the forming, and the support member is provided over a range including the female-side forming surface in the longitudinal direction.
According to an aspect of the present disclosure, there is provided a forming method of forming a laminate into a three-dimensional shape that extends in a longitudinal direction, that has a cross-sectional shape including curved portions in a cross-section cut along a plane orthogonal to the longitudinal direction, and that includes a bent portion in the longitudinal direction by using the above-described forming jig, the laminate being obtained by laminating reinforced fiber sheets, the forming method including a step of installing the laminate on the female die such that the laminate is supported by the support member provided on the female-side forming surface and a step of forming the laminate into the three-dimensional shape including the bent portion by sandwiching the laminate between the male die and the female die.
According to the aspects of the present disclosure, it is possible to suppress occurrence of a forming failure even in a case of forming a laminate into a three-dimensional shape.
Hereinafter, an embodiment according to the present disclosure will be described in detail with reference to the drawings. Incidentally, the invention is not limited by the embodiment. In addition, the components in the following embodiment include components that can be easily replaced by those skilled in the art, or components that are substantially the same. Further, the components to be described below can be appropriately combined, and when there are a plurality of embodiments, the embodiments can be combined.
In the case of a forming jig and a forming method according to Embodiment 1, a flat plate-shaped laminate is bent and formed into a three-dimensional shape. First, with reference to
(Laminate)
The laminate 1 has a shape including at least one curved portion 7 in a cross-section cut along a plane orthogonal to the longitudinal direction. Specifically, the laminate 1 has an Ω-shaped cross-section with a bottom plate portion 3, two side plate portions 4, and two flange portions 5. The two side plate portions 4 of the laminate 1 are provided to extend along the height direction (vertical direction in
In addition, the laminate 1 has a shape including at least one bent portion 8 in the longitudinal direction. Specifically, the laminate 1 includes two bent portions 8 in the longitudinal direction and includes a bent portion 8a protruding upward and a bent portion 8b protruding downward. The bent portion 8a protruding upward is formed on one side (front side in
(Forming Jig)
Next, a forming jig 10 for forming the laminate 1 of
As shown in
The female die 13 includes forming surfaces for forming lower surfaces of the laminate 1. That is, the forming surfaces of the female die 13 include female-side forming surfaces 21 for forming the bent portions 8 of the laminate 1. The female die 13 is formed into a recess-like shape (recessed shape) in a cross-section cut along a plane orthogonal to the longitudinal direction. Specifically, the female die 13 includes a bottom surface portion 13a and a pair of side surface portions 13b provided on both sides of the bottom surface portion 13a in the width direction. A forming surface on an inner side (upper side) of the bottom surface portion 13a forms an outer surface (lower surface) of the bottom plate portion 3 of the laminate 1. Forming surfaces on inner sides of the pair of side surface portions 13b form outer surfaces of the side plate portions 4 of the laminate 1 and forming surfaces on upper sides thereof form lower surfaces of the flange portions 5 of the laminate 1. In addition, the forming surfaces of the bottom surface portion 13a and the pair of side surface portions 13b of the female die 13 are forming surfaces (female-side forming surfaces 21) for bending the laminate 1 at the bent portions 8 in the longitudinal direction. That is, the female-side forming surfaces 21 for forming the bent portions 8 of the laminate 1 in the longitudinal direction include a female-side forming surface 21a at which a forming surface for forming the portion 1a on the one side in the longitudinal direction a forming surface for forming the portion 1b on the central side in the longitudinal direction intersect each other at a predetermined bending angle and a female-side forming surface 21b at which a forming surface for forming the portion 1b on the central side in the longitudinal direction and a forming surface for forming the portion 1c on the other side in the longitudinal direction intersect each other at a predetermined bending angle.
The male die 14 includes forming surfaces for forming upper surfaces of the laminate 1. That is, the forming surfaces of the male die 14 include male-side forming surfaces 22 for forming the bent portions 8 of the laminate 1. The male die 14 is fitted to the female die 13 with the laminate 1 interposed therebetween. The male die 14 is formed into a projection-like shape (protruding shape) in the cross-section cut along a plane orthogonal to the longitudinal direction. Specifically, the male die 14 includes a protrusion portion 14a and a pair of plate portions 14b provided on both sides of the protrusion portion 14a in the width direction. The protrusion portion 14a faces a recess formed by the bottom surface portion 13a and the pair of side surface portions 13b of the female die 13. Forming surfaces on outer sides (lower sides) of the protrusion portion 14a form an inner surface (upper surface) of the bottom plate portion 3 of the laminate 1 and inner surfaces of the pair of side plate portions 4. Forming surfaces on lower sides of the pair of plate portions 14b form upper surface of the flange portions 5 of the laminate 1. In addition, the forming surfaces of the protrusion portion 14a and the pair of plate portions 14b of the male die 14 are forming surfaces (male-side forming surfaces 22) for bending the laminate 1 at the bent portions 8 in the longitudinal direction. That is, the male-side forming surfaces 22 for forming the bent portions 8 of the laminate 1 in the longitudinal direction include a male-side forming surface 22a at which a forming surface for forming the portion 1a on the one side in the longitudinal direction a forming surface for forming the portion 1b on the central side in the longitudinal direction intersect each other at a predetermined bending angle and a male-side forming surface 22b at which a forming surface for forming the portion 1b on the central side in the longitudinal direction and a forming surface for forming the portion 1c on the other side in the longitudinal direction intersect each other at a predetermined bending angle.
Note that the bending angles at the female-side forming surface 21a and the male-side forming surface 22a are angles for a steep at the time of formation of a composite material and are angles steeper than an angle of “1:100” at which a length in the longitudinal direction becomes 100 when a length in the height direction changes by 1. Specifically, the bending angles at the female-side forming surface 21a and the male-side forming surface 22a are “1:40”.
The support member 15 is a member having extensibility, and in Embodiment 1, a thermoplastic film is used. In addition, the support member 15 has a thickness smaller than that of a reinforced fiber sheet constituting the laminate 1. The extension ratio of the support member 15 transitioning from a normal state to an extended state is within a range of 1.5 to 4. As shown in
In addition, as shown in
The support member 15 includes a plurality of support member segments 15a, 15b, and 15c into which the support member 15 is divided in the longitudinal direction. In Embodiment 1, for example, three support member segments 15a, 15b, and 15c are used. Regarding the three support member segments 15a and 15b, the support member segment 15a is provided on the one side (portion 1a side) in the longitudinal direction and the support member segment 15b is provided on the other side (portion 1b) in the longitudinal direction with the female-side forming surface 21a interposed therebetween. In addition, the support member segment 15c is provided closer to the other side (portion 1b) in the longitudinal direction than the support member segment 15b. In this manner, a range in which the support member 15 is provided on the portion 1b side is smaller than a range in which the support member 15 is provided on the portion 1a side.
The above-described support member 15 supports the laminate 1 in a state of being separated from the bottom surface portion 13a of the female die 13. That is, the support member 15 is provided between the female die 13 and the laminate 1 at the time of forming. When the male die 14 is pressed against the laminate 1 in this state, the support member 15 generates a force that relatively presses the laminate 1 to the male die 14. Here, the plurality of support member segments 15a, 15b, and 15c are different in force that relatively presses the laminate 1 to the male die 14 and the force becomes smaller away from the bent portion 8a (female-side forming surface 21a) in the longitudinal direction. Note that the force pressing the laminate is adjusted by means of the tension of the support member 15, and the tension of the support member segment 15a and the tension of the support member segment 15b are the same as each other and are larger than the tension of the support member segment 15c (larger tensile force is applied thereto). Note that the force pressing the laminate may be adjusted by means of the thickness of the support member 15. In this case, the thickness of the support member segment 15a and the thickness of the support member segment 15b are the same as each other and are larger than the thickness of the support member segment 15c.
Since the support member 15 has extensibility as described above, when the male die 14 is pressed toward the female die 13 in a state where the laminate 1 is supported, the support member 15 is extended by being pressed. Therefore, the laminate 1 is pressed into the female die 13 while being pressed against the male die 14 by the support member 15 at the bent portion 8a. In addition, after the laminate 1 is formed, the support member 15 is extended into a shape conforming to the forming surfaces of the female die 13.
Next, a forming method in which the above-described forming jig 10 is used will be described with reference to
As shown in
Step S12 shows the laminate 1 during the forming, a cross-section at the bent portion 8a that is orthogonal to the longitudinal direction is a cross-section A-A, and a cross-section at the bent portion 8b that is orthogonal to the longitudinal direction is a cross-section B-B. As shown in
Step S13 shows the laminate 1 after the forming. As shown in
Note that, in Embodiment 1, a thermoplastic film having extensibility is used as the support member 15 but there is no particular limitation. The support member 15 may be a member having elasticity, that is, both of extensibility and contractibility, and for example, rubber as an elastic member may be applied thereto. Specifically, the elastic member is sheet-shaped heat-resistant rubber, that is, a heat-resistant rubber sheet. Note that, the heat-resistant rubber is rubber having heat resistance higher than that of natural rubber, and is, for example, silicone rubber or the like.
In addition, in Embodiment 1, after the forming, the support member 15 in an extended state abuts the forming surfaces of the female die 13. However, a groove allowing a portion that the support member 15 abuts may be formed at the forming surfaces of the female die 13.
Next, a forming method in which the forming jig 10 according to Embodiment 2 is used will be described with reference to
In addition to the forming jig 10 according to Embodiment 1, the forming jig 10 according to Embodiment 2 further includes a tensile force applying unit that applies, to the laminate 1, a tensile force that pulls both sides of the laminate 1 in the width direction outward. As shown in
In the forming method, the tensile force applying unit applies a tensile force to the laminate 1 while the laminate 1 is being formed in step S12. Specifically, in step S12, a tensile force is applied to the laminate 1 such that the result of comparison between a tensile force F2 applied to the bent portion 8a of the laminate 1 shown in the cross-section A-A and a tensile force F1 applied to the bent portion 8b of the laminate 1 shown in the cross-section B-B becomes “F2>F1”.
As described above, the forming jig 10 and the forming method according to Embodiment 1 and Embodiment 2 are understood as follows, for example.
According to a first aspect, there is provided the forming jig 10 forming the laminate 1 into a three-dimensional shape that extends in the longitudinal direction, that has the cross-sectional shape including the curved portions 7 in a cross-section cut along a plane orthogonal to the longitudinal direction, and that includes the bent portion 8 in the longitudinal direction, the laminate 1 being obtained by laminating reinforced fiber sheets. The forming jig 10 includes the female die 13 that includes the female-side forming surface 21 for forming the bent portion 8, the male die 14 that is fitted to the female die 13 with the laminate 1 interposed therebetween and that includes the male-side forming surface 22 for forming the bent portion 8, and the support member 15 having extensibility that is provided between the female die 13 and the laminate 1 at a time of forming and that supports the laminate 1 in a state where the laminate 1 is separated from the female die 13. The laminate 1 abuts the male die 14 on both sides of the bent portion 8 to be formed in the longitudinal direction at the time of the forming, and the support member 15 is provided over a range including the female-side forming surface 21 in the longitudinal direction.
According to such a configuration, the laminate 1 can be separated from the female-side forming surface 21a of the female die 13 by means of the support member 15 even in a case where the male die 14 is pressed against the female die 13 in a state where both sides of the laminate 1 in the longitudinal direction with the bent portion 8a interposed therebetween abuts the male die 14. Therefore, the laminate 1 can be restrained from being restricted by the female die 13 at the bent portion 8a and thus surplus reinforced fiber sheets can be allowed even when the reinforced fiber sheets are sent toward between the female die 13 and the male die 14 in surplus due to the forming. Accordingly, even in a case of forming the laminate into a three-dimensional shape, it is possible to suppress generation of a wrinkle on the laminate 1 and to suppress occurrence of a forming failure.
According to a second aspect, the cross-section of the laminate 1 has an Ω-shape including the bottom plate portion 3, two side plate portions 4 that are provided on both sides of the bottom plate portion 3 with the curved portions 7 interposed therebetween, and two flange portions 5 that are provided on sides of the two side plate portions 4 opposite to the bottom plate portion 3 with the curved portions 7 interposed therebetween.
According to such a configuration, it is possible to form the laminate 1 into a three-dimensional shape of which the cross-section has an Ω-shape.
According to a third aspect, the support member 15 is a thermoplastic film or a heat-resistant rubber sheet.
According to such a configuration, it is possible to use a thermoplastic film or a heat-resistant rubber sheet which is a material appropriate for the support member 15 having extensibility and it is possible to suitably support the laminate 1.
According to a fourth aspect, the support member 15 is thinner than the reinforced fiber sheets.
According to this configuration, the trace of the support member 15 removed from the laminate 1 after the forming can be made unnoticeable.
According to a fifth aspect, the extension ratio of the support member 15 transitioning from a normal state to an extended state is within a range of 1.5 to 4.
According to such a configuration, the support member 15 can be suitably extended.
According to a sixth aspect, a tensile force applying unit that is provided in a range where the support member 15 is provided and that applies, to the laminate 1, a tensile force that pulls both sides of the laminate 1 outward in the cross-section is further provided.
According to such a configuration, it is possible to further relatively press the laminate 1 against the male die 14 by applying a tensile force to the bent portion 8a of the laminate 1. In addition, it is possible to restrain the reinforced fiber sheets from being sent toward between the female die 13 and the male die 14 in surplus at the time of the forming. Therefore, it is possible to further suppress generation of a wrinkle on the laminate 1 and to suppress occurrence of a forming failure.
According to a seventh aspect, the support member 15 includes the plurality of support member segments 15a, 15b, and 15c into which the support member 15 is divided in the longitudinal direction.
According to such a configuration, it is possible to appropriately support the laminate 1 with the plurality of support member segments 15a, 15b, and 15c.
According to an eighth aspect, a force by which the support member 15 that relatively presses the laminate 1 to the male die 14 becomes smaller away from the bent portion 8 in the longitudinal direction.
According to such a configuration, since a force by which the laminate 1 is pressed to the male die can be made smaller away from the bent portion 8a, a pressing force around the bent portion 8a can be made appropriate.
According to a ninth aspect, there is provided a forming method of forming the laminate 1 into a three-dimensional shape that extends in the longitudinal direction, that has the cross-sectional shape including the curved portions 7 in a cross-section cut along a plane orthogonal to the longitudinal direction, and that includes the bent portion 8 in the longitudinal direction by using the above-described forming jig 10, the laminate 1 being obtained by laminating reinforced fiber sheets. The forming method includes a step of installing the laminate 1 on the female die 13 such that the laminate 1 is supported by the support member 15 provided on the female-side forming surface 21 and a step of forming the laminate 1 into the three-dimensional shape including the bent portion 8 by sandwiching the laminate 1 between the male die 14 and the female die 13.
According to such a configuration, the laminate 1 can be separated from the female-side forming surface 21a of the female die 13 by means of the support member 15 even in a case where the male die 14 is pressed against the female die 13 in a state where both sides of the laminate 1 in the longitudinal direction with the bent portion 8a interposed therebetween abuts the male die 14. Therefore, the laminate 1 can be restrained from being restricted by the female die 13 at the bent portion 8a and thus surplus reinforced fiber sheets can be allowed even when the reinforced fiber sheets are sent toward between the female die 13 and the male die 14 in surplus due to the forming. Accordingly, even in a case of forming the laminate into a three-dimensional shape, it is possible to suppress generation of a wrinkle on the laminate 1 and to suppress occurrence of a forming failure.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/005201 | 2/10/2020 | WO |
