This application is based on and claims priorities under 35 USC 19 from Japanese Patent Application No. 2019-026967 filed Feb. 18, 2019 and Japanese Patent Application No. 2019-168388 filed Sep. 17, 2019.
The present invention relates to a shaping apparatus.
Patent Literature 1 discloses a configuration in which a shaping material is twisted by 180 degrees when a curve is formed by the shaping material in a three-dimensional shaping apparatus.
Patent Literature 1: Description of U.S. Pat. No. 10/046,511
In a configuration in which a discharging mechanism moves relative to a receiving portion such as a stand in a curved shape and discharges the shaping material to the receiving portion while twisting the shaping material by 180 degrees or more, the continuous fibers may be twisted.
Aspects of non-limiting embodiments of the present disclosure relate to reduce twisting of continuous fibers as compared with a configuration in which a shaping material is discharged on a receiving portion while being rotated by 180 degrees or more.
Aspects of certain non-limiting embodiments of the present disclosure address the above features and/or other features not described above. However, aspects of the non limiting embodiments are not required to address the features described above, and aspects of the non-limiting embodiments of the present disclosure may not address features described above.
According to an aspect of the present disclosure, there is provided a shaping apparatus including: a receiving portion configured to receive a linear shaping material including a bundle of continuous fibers impregnated with a resin; and a discharging mechanism configured to move relative to the receiving portion in a curved shape and discharge the shaping material on the receiving portion while rotating the shaping material in a range of less than 180 degrees to an opposite direction to a bending direction with respect to the receiving portion.
Exemplary embodiment(s) of the present invention will be described in detail based on the following figures, wherein:
Hereinafter, an exemplary embodiment is described based on the drawings. As shown in the drawings, an arrow H indicates an apparatus vertical direction (perpendicular direction), an arrow W indicates an apparatus width direction (horizontal direction), and an arrow D indicates an apparatus length direction (horizontal direction).
(Shaping Apparatus 10)
First, a shaping apparatus 10 is described.
The shaping apparatus 10 shown in
As shown in
(Stand 14, Moving Mechanism 18)
A stand 14 shown in
As shown in
The moving mechanism 18 shown in
More specifically, the moving mechanism 18 can move the stand 14 to any position in the apparatus vertical direction, the apparatus width direction, and the apparatus length direction. Accordingly, the moving mechanism 18 can move the stand 14 in a curved shape. In other words, the shaping unit 12 can move on the curve along the receiving surface 14A relative to the stand 14.
For example, a three-axis robot capable of moving the stand 14 to any position in the apparatus vertical direction, the apparatus width direction, and the apparatus length direction is used as the moving mechanism 18.
(Shaping Unit 12)
The shaping unit 12 shown in
(Support 60)
The support 60 supports each portion of the supply mechanism 20 and the conveyance portion 40.
(Supply Mechanism 20)
The supply mechanism 20 supplies the linear shaping material 100 in which the fiber bundle 110 is impregnated with the resin 112. Specifically, the supply mechanism 20 includes a supply portion 21, a winding roller 22, and an impregnating portion 24.
(Supply Portion 21)
The supply portion 21 has a function of supplying the fiber bundle 110 to the winding roller 22. Specifically, the supply portion 21 includes a reel around which the fiber bundle 110 is wound. The supply portion 21 is rotatably supported by the support 60.
The supply portion 21 rotates in a counterclockwise direction in
The fiber bundle 110 is obtained by bundling a plurality of continuous fibers 120 without being twisted. In the exemplary embodiment, as an example, carbon fibers having a diameter of 0.005 mm are used as the continuous fibers 120, and 1000 or more of the continuous fibers 120 are bundled. As shown in
(Winding Roller 22)
As shown in
The fiber bundle 110 unwound to the apparatus width direction from the supply portion 21 is wound around the winding roller 22, so that the fiber bundle 110 is fed downward by changing a direction downward. Therefore, the winding roller 22 has a function of guiding the fiber bundle 110 downward.
(Impregnating Portion 24)
The impregnating portion 24 impregnates the fiber bundle 110 with a resin to form the linear shaping material 100. As shown in
The impregnating portion 24 includes a passing portion 26 through which the fiber bundle 110 passes and a resin delivery portion 28 which delivers the resin to the passing portion 26.
The resin is housed in the resin delivery portion 28, and the resin delivery portion 28 includes a heater 28A which heats the housed resin, and a screw 28B which delivers the heated resin to the passing portion 26. In the exemplary embodiment, as an example, a polypropylene resin is housed inside the resin delivery portion 28 as the resin. The heater 28A is melted by heating the housed polypropylene resin to, for example, 200° C. or higher and 300° C. or lower.
The passing portion 26 is configured such that the fiber bundle 110 delivered from the supply portion 21 passes therethrough. The passing portion 26 has a cylindrical shape extending in the vertical direction. The passing portion 26 includes a receiving port 26A which receives the fiber bundle 110 unwound from the supply portion 21, and a columnar retaining portion 26B in which the resin is retained so as to surround the fiber bundle 110 passing therethrough from a circumferential direction. Further, the passing portion 26 includes: a discharging head 26C which discharges the shaping material 100 in which the fiber bundle 110 is impregnated with the resin; and a heater 26D which is attached to an outer circumferential wall of the retaining portion 26B and heats the resin retained in the retaining portion 26B. The receiving port 26A, the retaining portion 26B, and the discharging head 26C are arranged in this order from the upper to the lower. In the exemplary embodiment, the heater 26D heats the polypropylene resin retained in the retaining portion 26B to 200° C. or higher and 300° C. or lower as an example.
In the impregnating portion 24, the resin delivery portion 28 delivers the heated resin to the retaining portion 26B of the passing portion 26. The passing portion 26 is received from the receiving port 26A, and the fiber bundle 110 passing through the retaining portion 26B is impregnated with the resin. The passing portion 26 discharges the linear shaping material 100 in which the fiber bundle 110 is impregnated with the resin from the discharging head 26C. In the shaping material 100 discharged from the discharging head 26C, as shown in
In this way, the fibers are bonded to each other by the resin by impregnating the fiber bundle 110 with the resin. Accordingly, the impregnating portion 24 functions as a bonding means for bonding the fibers to each other.
(Conveyance Portion 40)
The conveyance portion 40 has a function of conveying the shaping material 100 from the supply mechanism 20 to the discharging portion 50. As shown in
The conveyance portion 40 includes, for example, a pair of conveyance rollers 42 and 44. The conveyance roller 44 is disposed on a side opposite to the conveyance roller 42 with respect to the shaping material 100.
The conveyance rollers 42 and 44 are rotatably supported by the support 60. The conveyance rollers 42 and 44 rotate in the circumferential direction by transmitting a driving force from a driving means (not shown). In the conveyance portion 40, the conveyance rollers 42 and 44 which rotate sandwich the shaping material 100 and convey it at a speed of, for example, 30 mm/sec. A conveyance speed of the shaping material 100 is not limited to 30 mm/sec.
The pair of conveyance rollers 42 and 44 may include a heating portion which heats the shaping material 100. The conveyance portion 40 may include a conveyance belt instead of the conveyance rollers 42 and 44.
(Discharging Portion 50)
The discharging portion 50 has a function of discharging the shaping material 100 to the stand 14. As shown in
The discharging portion 50 includes an inflow port 50C into which the shaping material 100 fed from the conveyance portion 40 flows and a discharging port 50B for discharging the shaping material 100 which has flowed in from the inflow port 50C to the receiving surface 14A of the stand 14. The discharging portion 50 may include a heating portion which heats the shaping material 100.
(Pressure Roller 56)
The pressure roller 56 functions as a pressurizing portion which pressurizes the shaping material 100 discharged from the discharging portion 50. Specifically, the shaping material 100 is sandwiched between the pressure roller 56 and the stand 14, and the shaping material 100 is pressed against the receiving surface 14A of the stand 14 to pressurize the shaping material 100. The pressure roller 56 pressurizes the shaping material 100, so that a height of the shaping material 100 discharged to the stand 14 is aligned.
The pressure roller 56 may include a heating portion which heats the shaping material 100. For example, a heating source provided inside the pressure roller 56 is used as the heating portion. Further, the heating portion may be a heating device which heats the pressure roller 56 from the outside. Examples of the heating source and the heating device include a heater using an electric heating wire, a halogen lamp, or the like.
(Rotation Mechanism 62)
The rotation mechanism 62 shown in
In other words, the rotation mechanism 62 has a function of rotating the supply mechanism 20 and the conveyance portion 40. Specifically, the rotation mechanism 62 has a function of rotating the supply portion 21, the winding roller 22, the impregnating portion 24, and the conveyance portion 40. Incidentally,
The rotation mechanism 62 has a function of twisting the shaping material 100 around the axis along the vertical direction by rotating the support 60. Specifically, in a case where the shaping unit 12 moves relative to the stand 14 in a curved shape, the rotation mechanism 62 rotates the shaping material 100 in a range of less than 180 degrees in an opposite direction SB (see
(Control Unit 16)
The control unit 16 controls operation of each unit of the shaping apparatus 10. Specifically, the control unit 16 includes a storage portion including a ROM, a storage, or the like in which a program is stored, and a processor which operates according to the program, and the operation of each unit of the shaping apparatus 10 is controlled by reading and executing the program stored in the storage portion.
In the embodiments, the term “processor” refers to hardware in a broad sense. Examples of the processor includes general processors (e.g., CPU: Central Processing Unit), dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Integrated Circuit, FPGA: Field Programmable Gate Array, and programmable logic device).
In the embodiments, the term “processor” is broad enough to encompass one processor or plural processors in collaboration which are located physically apart from each other but may work cooperatively. The order of operations of the processor is not limited to one described in the embodiments above, and may be changed.
As shown in
The control unit 16 controls operation of the moving mechanism 18, the impregnating portion 24, the conveyance portion 40, and the rotation mechanism 62 so that the following shaping operation is executed based on a plurality of layer data created from three-dimensional data of the shaping object.
(Shaping Operation of Shaping Apparatus 10)
Here, shaping operation of shaping a shaped object including a curve part based on the plurality of layer data created from the three-dimensional data of the shaped object is described. Specifically, as shown in
In the case of shaping the U-shaped part 200, the moving mechanism 18 moves the stand 14 to move the shaping unit 12 relative to the stand 14 in a U shape. Specifically, first, the shaping unit 12 relatively moves in a linear shape in a plan view in a first direction M1 (see
Next, the shaping unit 12 moves relative to, for example, the receiving surface 14A of the stand 14 in a curved shape (hereinafter referred to as a curve movement). Next, the shaping unit 12 relatively moves in a linear shape in a plan view in a direction M2 opposite to the first direction M1 (see
In the curve movement, specifically, as shown in
In the shaping unit 12, as shown in
In the curve movement of the shaping unit 12, the rotation mechanism 62 rotates the support 60 around the axis along the vertical direction in the opposite direction SB (see a direction of an arrow SB) on a side opposite to the bending direction RA. The bending direction RA is a clockwise direction (that is, a direction toward the right direction) in the space of
In the shaping apparatus 10 according to the exemplary embodiment, the shaping material 100 is discharged on the stand 14 while rotating in a range of less than 180 degrees in the opposite direction SB in the curve movement of the shaping unit 12.
Specifically, the rotation mechanism 62 discharges the shaping material 100 to the stand 14 while rotating the shaping material 100 at a rotation angle θX corresponding to a bending angle θA of the shaping unit 12 with respect to the stand 14 in the curve movement of the shaping unit 12. The bending angle θA is an angle formed by a line segment connecting the center of the shaping material 100 and the movement center PA at a start position of the curve movement and a line segment connecting the center of the shaping material 100 and the movement center PA during the curve movement. The rotation angle θX is an angle with respect to a proceeding path 12S of a line HA connecting the part (point 100A) of the shaping material 100 facing the proceeding direction of the discharging portion 50 and the center of the shaping material 100 at the start of the curve movement.
In a range where the bending angle θA is less than 90 degrees (a range of NA in
In a range where the bending angle θA is less than 90 degrees, as shown in
Further, when the bending angle θA is 90 degrees, the rotation angle θX is set as 90 degrees same as the bending angle θA of the shaping unit 12. Further, in a range where the bending angle θA is more than 90 degrees and less than 180 degrees (a range of NB in
Then, in the exemplary embodiment, a continuous fiber 128 (see
That is, the continuous fiber 128 proceeds on the inner peripheral side of the shaping material 100 so as to approach the continuous fiber 129. In other words, the continuous fiber 128 proceeds on the inner peripheral side of the shaping material 100 so as to increase the bending radius. On the other hand, the continuous fiber 129 proceeds on the outer peripheral side of the shaping material 100 so as to approach the continuous fiber 128. The continuous fiber 129 proceeds on the outer peripheral side of the shaping material 100 so as to decrease the bending radius.
As described above, in the shaping apparatus 10 according to the exemplary embodiment, the shaping material 100 is discharged to the stand 14 in a curved shape so that the continuous fiber 128 on the inner peripheral side of the shaping material 100 and the continuous fiber 129 on the outer peripheral side of the shaping material 100 approach each other.
Here, in the curve movement of the shaping unit 12, as shown in
Further, in a case where the shaping material 100 is discharged to the stand 14 while being rotated in the bending direction RA (hereinafter referred to as a second comparative example), the continuous fiber 128 and the continuous fiber 129 are separated, and cracks easily occur in the curved portion of the shaping material 100.
Correspondingly, in the shaping apparatus 10 according to the exemplary embodiment, the shaping material 100 is discharged to the stand 14 in a curved shape so that the continuous fiber 128 on the inner peripheral side of the shaping material 100 and the continuous fibers 129 on the outer peripheral side of the shaping material 100 approach each other.
Therefore, the continuous fiber 129 proceeding on the outer peripheral side of the shaping material 100 is difficult to crack due to a shorter distance of proceeding than those of the first comparative example and the second comparative example. As a result, the shaping material 100 is difficult to crack on the outer peripheral side. In the continuous fiber 128 proceeding on the inner peripheral side of the shaping material 100, parts are difficult to overlap on the inner peripheral side with each other due to a longer distance of proceeding than those of the first comparative example and the second comparative example. As a result, the shaping material 100 is difficult to crack even on the inner peripheral side. Therefore, cracks in the curved portion of the shaping material 100 are reduced. In
Further, in the shaping apparatus 10, as described above, the shaping material 100 is discharged to the stand 14 while rotating in a range of less than 180 degrees in the curve movement of the shaping unit 12. Here, in a case where the shaping material 100 is discharged to the stand 14 while rotating by 180 degrees or more (hereinafter referred to as a third comparative example), the continuous fibers 120 are easily twisted. When the continuous fibers 120 are twisted, an undulation occurs in the shaping material 100 constituting the U-shaped part 200 of the shaped object, or the continuous fibers 120 are damaged.
Correspondingly, in the shaping apparatus 10, since the shaping material 100 is discharged to the stand 14 while rotating in a range of less than 180 degrees in the curve movement of the shaping unit 12, twisting of the continuous fibers 120 is reduced compared with the third comparative example.
In the shaping apparatus 10, the shaping material 100 is discharged to the stand 14 while rotating the shaping material 100 at a rotation angle θX corresponding to a bending angle θA of the shaping unit 12 in the curve movement of the shaping unit 12. Specifically, in a range where the bending angle θA is less than 90 degrees, the rotation angle θX of the shaping material 100 increases as the bending angle θA increases. Accordingly, the continuous fiber 128 and the continuous fiber 129 gradually approach each other in the range where the bending angle θA is less than 90 degrees as compared with a case where the rotation angle θX of the shaping material 100 is constant regardless of the bending angle θA of the shaping unit 12 (hereinafter referred to as a fourth comparative example). Therefore, cracks in the curved portion of the shaping material 100 are reduced as compared with the fourth comparative example.
In the shaping apparatus 10, in a range where the bending angle θA is less than 90 degrees, the rotation angle θX is set as a rotation angle larger than the bending angle θA.
Therefore, the continuous fiber 128 and the continuous fiber 129 approach each other as compared with a case where the shaping material is discharged to the discharged portion while being rotated to a rotation angle equal to or less than the bending angle (hereinafter referred to as a fifth comparative example). Therefore, as compared with the fifth comparative example, cracks in the curved portion of the shaping material 100 are reduced.
In the shaping apparatus 10, in a range where the bending angle θA is less than 90 degrees, the rotation angle θX is set as a rotation angle equal to or less than 90 degrees. Therefore, twisting of the continuous fibers 120 is reduced as compared with a configuration in which the shaping material 100 is rotated at a rotation angle more than 90 degrees. As a result, damage of the continuous fibers 120 and cracks in the curved portion of the shaping material 100 caused by the damage are reduced.
That is, according to the shaping apparatus 10, cracks in the curved portion of the shaping material 100 are reduced as compared with a configuration in which the shaping material 100 is discharged to the stand 14 while being rotated at a rotation angle θX larger than the bending angle θA and more than 90 degrees.
In the shaping apparatus 10, the rotation mechanism 62 rotates the shaping material 100 in the opposite direction SB by rotating the supply mechanism 20 and the conveyance portion 40 in the opposite direction SB in a range where the bending angle θA is less than 90 degrees. Therefore, twisting of the continuous fibers 120 is reduced as compared with a configuration in which only the conveyance portion 40 rotates.
More specifically, in the shaping apparatus 10, the rotation mechanism 62 rotates the shaping material 100 in the opposite direction SB by rotating the supply portion 21, the winding roller 22, the impregnating portion 24, and the conveyance portion 40 in the opposite direction SB. Therefore, twisting of the continuous fibers 120 is reduced as compared with a configuration in which only a part of the supply portion 21, the winding roller 22, and the impregnating portion 24 and the conveyance portion 40 rotate.
In the shaping apparatus 10, in a range where the bending angle θA is more than 90 degrees and less than 180 degrees (a range of NB in
In the shaping unit 12, when one layer is formed on the receiving surface 14A, the moving mechanism 18 moves the stand 14 downward. Thereafter, the above step is repeated, and a plurality of layers overlap to shape a shaped object.
The shaping apparatus 10 may be configured to discharge the shaping material 100 to the stand 14 when the circular cross section of the shaping material 100 is deformed into a flat cross section (see
Here, the flat cross section is a cross section in which a length in one direction of the cross section is longer than a length in an intersection direction intersecting with the one direction in the cross section, and a pair of planes (hereinafter, “flat plane 100D”) facing in the intersection direction is formed. That is, the flat planes 100D are a pair of planes facing in a short-length direction of the flat shape.
The deformation of the shaping material 100 into the flat cross-sectional shape is performed by, for example, pressurizing and heating at the pair of conveyance rollers 42 and 44 of the conveyance portion 40. In this case, a heating portion which heats the shaping material 100 is included in at least one of the pair of conveyance rollers 42 and 44.
Also in this modification, as shown in
The shaping unit 12 may be configured to change at least one setting of the rotation angle and a rotation speed of the shaping material 100 depending on a ratio of the continuous fibers to the shaping material 100.
Here, when the ratio of the continuous fibers to the shaping material 100 increases, rigidity of the shaping material 100 increases, and thus the shaping material 100 is difficult to rotate. In other words, when the ratio of the continuous fibers to the shaping material 100 increases, a rotation amount of the shaping material 100 may decrease with respect to a rotation amount of the support 60 by the rotation mechanism 62. In addition, response of rotation of the shaping material 100 in the discharging portion 50 may decrease with respect to the rotation of the support 60 due to the rotation mechanism 62.
Therefore, for example, in the case where the ratio of the continuous fibers to the shaping material 100 increases, the control unit 16 changes at least one setting of the rotation angle and the rotation speed of the shaping material 100 so that at least one of the rotation angle and the rotation speed of the shaping material 100 increases.
Accordingly, regardless of the ratio of the continuous fibers to the shaping material, rotation failure of the shaping material 100 (not rotating to a target rotation angle) is reduced as compared with a configuration in which the rotation angle and the rotation speed of the shaping material in the discharging mechanism are constant (hereinafter, the configuration is referred to as a sixth comparative example). As a result, cracks in the curved portion of the shaping material 100 are reduced as compared with the sixth comparative example.
The ratio of the continuous fibers to the shaping material 100 is changed by an amount of a resin supplied to the fiber bundle 110 in the impregnating portion 24. Specifically, when the amount of the resin supplied to the fiber bundle 110 in the impregnating portion 24 increases, the ratio of the continuous fibers to the shaping material 100 decreases, and when the amount of the resin supplied to the fiber bundle 110 in the impregnating portion 24 decreases, the ratio of the continuous fibers to the shaping material 100 increases. The control unit 16 changes at least one setting of the rotation angle and the rotation speed of the shaping material 100 based on a ratio of the continuous fibers to the shaping material 100 determined from the amount of the resin with respect to the shaping material 100.
In addition, in the case where the ratio of the continuous fibers to the shaping material 100 decreases, the control unit 16 may change at least one setting of the rotation angle and the rotation speed of the shaping material 100 so that at least one of the rotation angle and the rotation speed of the shaping material 100 decreases.
Further, setting of shaping conditions may be changed depending on the rotation angle and the rotation speed of the shaping material 100 in the shaping unit 12. The shaping conditions include a heating temperature of the heater 28A of the impregnating portion 24, heating time of the resin by the heater 28A, and the like.
Here, when at least one of the rotation angle and the rotation speed of the shaping material 100 increases, the twisting of the continuous fibers 120 increases, and an undulation is easy to occur in the shaping material 100 forming the U-shaped part 200 of the shaped object.
Therefore, in the case where at least one setting of the rotation angle and the rotation speed of the shaping material 100 is changed so that at least one of the rotation angle and the rotation speed of the shaping material 100 increases, for example, at least one of the heating temperature of the heater 28A of the impregnating portion 24 and the heating time of the resin by the heater 28A is increased.
Accordingly, regardless of the rotation angle and the rotation speed of the shaping material 100 in the shaping unit 12, the undulation is reduced in the shaping material 100 constituting the U-shaped part 200 of the shaped object and shaping failure of the shaped object is reduced as compared with the configuration in which the shaping conditions are constant.
Further, as shown in
Specifically, an applying portion 90 which applies tension to the shaping material 100 on the upstream side of the conveyance portion 40 is provided in the configuration shown in
Here, in a configuration (hereinafter referred to as a seventh comparative example) in which the shaping material 100 is discharged to the base 14 when no tension is applied, rotation failure of the shaping material 100 (not rotating to a target rotation angle) may occur due to relaxation of the shaping material 100.
In the present modification, since the shaping unit 12 discharges the shaping material 100 to the stand 14 while rotating the shaping material 100 in the opposite direction SB when tension is applied to the shaping material 100, the rotation failure of the shaping material 100 (not rotating to the target rotation angle) is reduced as compared with the seventh comparative example. As a result, cracks in the curved portion of the shaping material 100 are reduced as compared with the seventh comparative example.
In addition, in a configuration (hereinafter referred to as an eighth comparative example) in which tension is applied to the shaping material 100 on the downstream side of the conveyance portion 40, conveyance failure (that a target conveyance amount cannot be conveyed) of the shaping material 100 may occur due to relaxation of the shaping material 100.
In this modification, since tension is applied to the shaping material 100 on the upstream side of the conveyance portion 40, conveyance failure (the target conveyance amount cannot be conveyed) of the shaping material 100 is reduced as compared with the eighth comparative example.
In the example shown in
For example, operation of rotating the shaping material 100 in the forward direction SA may be repeated after the shaping material 100 is rotated in the opposite direction SB in a range where the bending angle θA is 180 degrees or less. Specifically, as an example, as shown in
In a range where the bending angle θA is equal to or less than 45 degrees (a range of MA in
In a range where the bending angle θA is more than 45 degrees and equal to or less than 90 degrees (a range of MB in
Further, in the example shown in
In the range where the bending angle θA is more than 90 degrees and equal to or less than 135 degrees (a range of MC in
In a range where the bending angle θA is more than 135 degrees and equal to or less than 180 degrees (a range of MD in
As described above, by repeating the operation of rotating the shaping material 100 in the opposite direction SB and then rotating the shaping material 100 in the forward direction SA, even though the rotation angle θX in the opposite direction SB in one operation is reduced, as shown in
As a result, since a path length difference between the continuous fiber 128 and the continuous fiber 129 decreases, cracks in the curved portion of the shaping material 100 are reduced compared with the configuration in which the operation of rotating the shaping material 100 in the opposite direction SB and then rotating the shaping material 100 in the forward direction SA is performed only once.
In the example shown in
(Modification of Configuration which Rotates Shaping Material 100)
In the example shown in
Further, when the cross section of the shaping material 100 is not circular, as shown in
A stress sensor may be provided on the support member 47 or the guide 49 to detect the stress (twist force) accumulated in the shaping material 100. Further, the rotation angle θX of the shaping material 100 may be controlled based on the detection result.
(Allowable Twist Angle of Shaping Material 100)
Here, an allowable twist angle of the shaping material 100 will be described.
Among the plurality of continuous fibers 120 present in the shaping material 100, a distance between continuous fibers 120 which are farthest away along a perpendicular direction to the shaping direction is set as a distance d [mm] between fibers (see
Assuming that the distance d [mm] between fibers is a fixed value without a change during the shaping, when a curve having a radius of curvature R [mm] and a shaping angle θdp [rad] is always shaped with the shaping material 100 facing the shaping direction, the difference between a path length (10L in
Path length difference=(R+½d)θdp−(R−½d)θdp=dθdp [mm]
At this time, since a path length of the center of the shaping material 100 is Rθdp [mm], an elongation rate of the continuous fibers 120 is d/R.
In general, carbon fibers have a characteristic value of an elongation rate at break of pulling and breaking equal to or higher than it. For example, in a case where the elongation rate at break Ef is 1%, a fiber of 100 mm breaks when it is lengthened beyond 101 mm. Therefore, when d/R>Ef at the time of curve shaping, the continuous fibers 120 break and strength decreases.
In order to avoid breakage of the continuous fibers 120, it is necessary to decrease the distance d between fibers or to increase the radius of curvature to keep conditions d/R≤Ef. When the distance d between fibers is decreased, there are demerits that time required for shaping increases; when the radius of curvature R is increased, there arises a problem that shaping cannot be performed finely.
Here, the twist angle θtw [rad] obtained by twisting the shaping material 100 from the shaping direction is constant, the elongation rate of the continuous fibers in the case where the curve is shaped is dcos θtw/R, and the elongation rate is reduced by twisting (see
Even when the shaping material 100 is twisted, the path length difference is generated in the continuous fibers 120. For simple description, first, a case in which the shaping material 100 is twisted at the time of linear shaping is as follows.
As shown in
Therefore, the elongation rate is (dsin Δθtw)/L.
When the above calculation is expanded at the time of curve shaping, it is as follows. L is Rθdp [mm].
When Δθtw coincides with a reverse direction of the shaping angle θdp, that is, −θdp, the elongation rate ratetw due to twisting is as follows.
rate=(d sin Δθtw)/Rθdp=(d sin(−θdp))/Rθdp
The elongation rate ratedp by the curve shaping has the same value as that of the d/R with an opposite sign. The fiber elongation rate in the case of curve shaping by twisting the shaping material 100 in the reverse direction due to the curve shaping is offset against that due to the twisting, ratetw+ratedp=0, the overall fiber elongation rate becomes zero, and utility to avoid breakage is expressed by a mathematical expression.
Therefore, since a condition that |ratetw+ratedp|<Ef is always satisfied at the time of shaping, damage (specifically, breakage) of the continuous fibers 120 is avoided.
Then, in the exemplary embodiment, the following conditions 1 and 2a are satisfied when the discharging mechanism moves linearly relative to the receiving portion and discharges the shaping material on the receiving portion; and the following conditions 1 and 2b are satisfied when the discharging mechanism moves relative to the receiving portion in the curved shape and discharges the shaping material on the receiving portion:
|θtw|≤π/2 Condition 1:
|dωtw|≤Ef Condition 2a:
|d(1+ktw)/R|≤Ef Condition 2b:
In which:
θtw is a twist angle of the shaping material as the rotation angle;
d [mm] is a farthest distance between the continuous fibers that are farthest away among the plurality of continuous fibers of the shaping material along the perpendicular direction to the proceeding direction of the discharging mechanism;
Ef is an elongation at break of the continuous fiber;
ωtw [rad/mm] is a twist angle per unit moving distance when the discharging mechanism moves linearly relative to the receiving portion;
θdp [rad] is the bending angle of the discharging mechanism with respect to the receiving portion when the discharging mechanism moves relative to the discharge portion in the curved shape;
R [mm] is the radius of curvature of the curved shape; and
ktw is a ratio of the bending angle θdp to the twist angle θtw.
According to the configuration, since damage (specifically, breakage) of the continuous fibers 120 is avoided as compared with a configuration satisfying only the condition 1, cracks in the curved portion of the shaping material 100 are reduced.
(Modification in Which Plurality of Shaping Units 12 are Provided)
As illustrated in
Specifically, the support 60 (see
In the present modification, a feeding speed of the shaping material 100 discharged from the discharging portion 50 (specifically, a conveyance speed of the shaping material 100 by the conveyance portion 40) and the rotation angle θX (twist angle) of the shaping material 100 are controlled in each of the four shaping units 12.
Specifically, for example, in the curve movement (movement indicated by an arrow ZB in
Accordingly, in the curve movement of the shaping unit 12, the feeding speed of the shaping material 100 increases on the outer peripheral side having a longer path length than the inner peripheral side.
Further, in the curve movement of the shaping unit 12, the rotation angle θX (twist angle) is reduced in the shaping unit 12 which is disposed outside the shaping unit 12 disposed on the innermost side.
For example, the rotation angle θX (twist angle) of each of the shaping units 12A, 12B, 12C, and 12D in a case of moving the shaping units 12A, 12B, 12C, and 12D including the curve movement as shown in
In
In
Then, as shown in the graph of
In the movement range indicated by the arrow ZD, the rotation angle θX (twist angle) is controlled so that the rotation angle θX (twist angle) in the shaping unit 12D becomes larger than that in the shaping units 12A, 12B, and 12C.
From above, in the curve movement of the shaping unit 12, the rotation angle θX (twist angle) of the shaping material 100 decreases on the outer peripheral side having a smaller curvature than the inner peripheral side. As a result, twisting of the continuous fibers 120 is reduced as compared with a configuration in which the rotation angles of the shaping units 12A, 12B, 12C, and 12D are always the same. Further, in the present modification, since the shaping unit 12 rotates the shaping material 100 when the curvature is more than the predetermined threshold value, twisting of the continuous fibers 120 is reduced compared with a configuration in which the shaping material 100 is always rotated by the plurality of shaping units 12 regardless of the threshold value.
In the exemplary embodiment, the stand 14 is moved with respect to the shaping unit 12, but the present invention is not limited thereto. For example, the shaping unit 12 may be moved with respect to the stand 14, and the shaping unit 12 may be configured to move relative to the stand 14 by moving at least one of the shaping unit 12 and the stand 14.
In the exemplary embodiment, the shaping apparatus 10 includes the impregnating portion 24, but may not include the impregnating portion 24. In this case, for example, the linear shaping material 100 in which the fiber bundle 110 is pre-impregnated with the resin 112 may be supplied from the supply portion 21.
In the present embodiment, the rotation angle θX is set as a rotation angle larger than the bending angle θA and equal to or less than 90 degrees, but the present invention is not limited thereto. For example, the rotation angle θX may be smaller than the bending angle θA. Further, the rotation angle θX may be an angle more than 90 degrees if it is in a range of less than 180 degrees.
The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
Number | Date | Country | Kind |
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2019-026967 | Feb 2019 | JP | national |
2019-168388 | Sep 2019 | JP | national |