JP5137721B2 - Advanced grid structure with insert - Google Patents

Description

  The present invention relates to an advanced grid structure with bonded inserts with low thermal expansion properties using carbon fiber reinforced plastics, which are lighter than metal and have a lower coefficient of thermal expansion.

In recent years, with the increasing demand for high-resolution images on the earth, there are plans to deploy a large number of small satellites equipped with optical equipment in low-orbit earth orbit, and the development of small satellites equipped with optical equipment is important. Is being viewed. Such a satellite is required to have a satellite structure having thermal dimensional stability in order not to deteriorate the observation accuracy of the optical equipment.
A satellite structure made of carbon fiber reinforced plastic has been proposed as a satellite structure having better thermal dimensional stability than a conventional metal satellite structure made of aluminum. One of them is a satellite structure having a composite triangular lattice. The satellite structure of the composite triangular lattice is provided in a group of equilateral triangles composed of carbon fiber reinforced plastic and nodes of equilateral triangles. It is configured by combining a metal insert.
In the equilateral triangle lattice group, a cylindrical metal insert is installed in advance at the node position of the equilateral triangle, and a carbon fiber thread impregnated with resin is wound around the insert so as to form an equilateral triangle lattice group. Then, it is formed by a so-called filament winding molding method in which molding is performed by heating under pressure.
Further, the metal insert is integrated with the equilateral triangle lattice group by curing the resin when the equilateral triangle lattice group is heated and molded under pressure. The metal insert has a cylindrical shape, and can be coupled using a coupling portion of the mounted device and a pin. In this way, a low thermal expansion structure having an insert structure for coupling with a mounted device or another structure is realized (for example, see Patent Document 1).

U.S. Pat. No. 4,137,354

However, the low thermal expansion structure with the above-mentioned insert structure is wound under a pressure by pressurizing a metal-impregnated thread around a metal insert placed in advance at the node position of the equilateral triangle of the equilateral triangle lattice group. Therefore, the pull-out strength of the insert is an adhesive strength due to curing of the resin, and has a low tensile strength of about 40 MPa.
Moreover, in the low thermal expansion structure having the above-described insert structure, the thermal expansion coefficient of the structure composed of the carbon fiber reinforced plastic is about −3.0 ppm / K to 3.0 ppm / K. Since the thermal expansion coefficient of an insert made of a metal such as aluminum or titanium is 10.0 ppm / K to 23.0 ppm / K, the structure is heated and molded under pressure, and then cooled from the molding temperature. In the process, the pull-out strength of the insert is reduced due to the difference in thermal stress due to the difference in thermal expansion coefficient between the structure and the insert.

  An object of the present invention is to provide an advanced grid structure having a low thermal expansion characteristic, including an insert structure having a high pull-out strength.

The advanced grid structure with an insert according to the present invention includes a first tape prepreg group in which carbon fibers arranged at equal intervals in a first direction are oriented in a longitudinal direction, and a counterclockwise with respect to the first direction. A second tape prepreg group in which carbon fibers arranged at equal intervals in a second direction inclined 60 degrees in the direction are oriented in the longitudinal direction, and inclined 60 degrees clockwise with respect to the first direction. In the third tape prepreg group in which carbon fibers arranged at equal intervals in the third direction are oriented in the longitudinal direction, two tape prepreg groups overlap each other and three tape prepreg groups do not overlap at the same position. The tape prepreg is formed from an equilateral triangular area composed of the first tape prepreg, the second tape prepreg, and the third tape prepreg. The first prepreg sheet group in which the carbon fibers are oriented in one direction in the first direction in the shape of the gathering region excluding the intersecting region, the first tilted 60 degrees counterclockwise with respect to the first direction The second prepreg sheet group in which the carbon fibers are oriented in one direction in two directions, and the carbon fibers are oriented in one direction in a third direction inclined 60 degrees clockwise with respect to the first direction. An advanced grid structure with an insert, in which a third prepreg sheet group is sequentially laminated in the gathering region and formed by heating under pressure, and is drilled in an insert member surrounded by three grid side groups. In the first tape prepreg group, the first grid side group constituting one side of the grid group and the same direction as the second tape prepreg group. Among the second grid side group that constitutes one side of the grid group, and the third grid side group that is in the same direction as the third tape prepreg group and constitutes one side of the grid group, the second grid side group A center point of an area where the grid side group and the third grid side group intersect and an area where the second grid side group and the third grid side group closest to the intersecting area intersect. The structure ratio obtained by dividing the grid side width by the distance from the center point is greater than 0 and 0.089 or less , and the insert member surrounded by the three grid side groups is a carbon fiber reinforced plastic structure. Accordingly, the thermal expansion coefficient is −0.9 ppm / K or more and 0.9 ppm / K or less.

  The advanced grid structure with an insert according to Embodiment 1 of the present invention has three grid side groups in which the grid sides on which the carbon fibers are oriented in one direction are arranged at equal intervals. Since the remaining second grid side group and the third grid side group intersect with each other with an inclination of 60 degrees clockwise and counterclockwise with respect to the first grid side group, the grid side groups do not intersect each other. The part where the carbon fiber is laminated only in one direction and the intersection region part where the grid side group intersects, and the part where the carbon fiber which is not intersecting the grid side group is laminated only in one direction and the grid side In an advanced grid structure having low thermal expansion characteristics by adjusting the ratio of the intersecting region part where the group intersects with the structure ratio, three grids The equilateral triangle grid group composed of three grid side groups has characteristics close to a carbon fiber reinforced plastic structure in which carbon fibers are laminated in a quasi-isotropic manner because regions where the id groups intersect with each other exist in the vicinity. Because it has a structure, it has high pull-out strength and low residual thermal stress characteristics by embedding a part of carbon fiber reinforced plastic structure with carbon fiber quasi-isotropically laminated in the equilateral triangle grid group and integrally molding it. The effect is that it has an insert structure and low thermal expansion characteristics.

Embodiment 1 FIG.
The vocabulary used in the following description will be described. “Grid side” means what constitutes the sides of an equilateral triangular grid and a hexagonal grid included in the advanced grid structure, which will be described in detail later. The “tape prepreg” is a semi-cured tape-like product produced by impregnating a resin into a plurality of collected carbon fibers.

1 is a plan view of a tape prepreg for manufacturing an advanced grid structure in an advanced grid structure with an insert according to Embodiment 1 of the present invention.
A method for manufacturing the advanced grid structure with insert according to Embodiment 1 of the present invention will be described. First, a method for manufacturing the advanced grid structure will be described, and then a method for manufacturing the insert structure will be described.
A belt-shaped tape prepreg in which carbon fibers are oriented in the longitudinal direction is prepared using Toray Industries, Inc. Torayca (registered trademark) yarn T800HB and an epoxy resin raw material.
A carbon fiber tape prepreg 14 in which the carbon fibers as shown in FIG. 1A are oriented parallel to the reference side 13 and the carbon fibers as shown in FIG. A +60 degree carbon fiber tape prepreg 16 oriented to tilt 60 degrees counterclockwise, and a carbon fiber as shown in FIG. 1C oriented so that it tilts 60 degrees clockwise relative to the reference side 17. The -60 degree direction carbon fiber tape prepregs 18 are sequentially laminated a plurality of times to produce a laminate of tape prepregs.

  The laminate of tape prepregs is an equilateral triangle formed by a 0 degree direction carbon fiber tape prepreg 14, a +60 degree direction carbon fiber tape prepreg 16, and a −60 degree direction carbon fiber tape prepreg 18 as shown in FIG. It has a region 19. The equilateral triangle area 19 includes a first intersection area 8, a second intersection area 9, a third intersection area 10, and a first intersection area 8, a second intersection area 9, and a third intersection area. It has a collection area 20 excluding 10. The collective region 20 hatched with diagonal lines in FIG. 2A has three trapezoid regions that overlap the equilateral triangle grid, and an equilateral triangle region in which three sides are connected to the upper side of the three trapezoid regions.

FIG. 2 is a plan view of a prepreg for manufacturing the insert structure in the advanced grid structure with an insert according to the first embodiment of the present invention.
A prepreg having the same shape and outer shape of the aggregate region 20 in which carbon fibers are oriented in a direction parallel to each side of the equilateral triangle region of the aggregate region 20 using Toray Industries, Inc. trading card (registered trademark) yarn T800HB and an epoxy resin raw material Prepare.
Then, the 0 degree direction carbon fiber prepreg 22 in which the carbon fibers as shown in FIG. 2B are oriented in parallel to the reference side 21 so as to overlap the assembly region of the laminated body of the tape prepregs is shown in FIG. A carbon fiber prepreg 24 having a +60 degree direction oriented so that the carbon fiber as shown inclines 60 degrees counterclockwise with respect to the reference side 23, and the carbon fiber as shown in FIG. -60 degree direction carbon fiber prepreg 26 oriented so as to incline 60 degrees clockwise, in turn, 0 degree direction carbon fiber tape prepreg 14, +60 degree direction carbon fiber tape prepreg 16, and -60 degree direction carbon fiber prepreg The assembly region 20 formed by the lamination of the prepregs 18 is laminated a plurality of times alternately with the lamination of the three tape prepregs.

  However, the maximum number of laminations of the 0 degree direction carbon fiber prepreg 22, the +60 degree direction carbon fiber prepreg 24, and the -60 degree direction carbon fiber prepreg 26 is the 0 degree direction carbon fiber tape prepreg 14 and the +60 degree direction carbon fiber prepreg. It is the number of layers of the prepreg 16 and the -60 degree carbon fiber tape prepreg 18, and from the viewpoint of weight, it is desirable to reduce the number of layers as much as possible within the range satisfying the allowable design strength.

Next, a method for forming the laminated prepreg by heating under pressure will be described.
FIG. 3 is a view for explaining a state in which an insert structure is formed in the advanced grid structure according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view of the same cross section as the AA cross section of FIG. 2A after the prepreg is laminated on the tape prepreg.
A predetermined number of tape prepregs are laminated on the molding plate 28. Then, a triangular-shaped silicone rubber 27 having a cross section of the shape of a region other than the region where the tape prepreg is laminated in the regular triangle region 19 is inserted into a region other than the region where the tape prepreg is laminated.
Next, the 0 degree direction carbon fiber prepreg 22 is laminated on the tape prepreg laminated. Next, a tape prepreg is laminated thereon, and a +60 degree direction carbon fiber prepreg 24 is laminated thereon. Further, a tape prepreg is laminated thereon, and a −60 degree carbon fiber prepreg 26 is laminated thereon. Next, a tape prepreg is laminated thereon, and the molding plate 28 is placed on the top. In FIG. 3A, the number of laminated layers of the 0 degree direction carbon fiber prepreg 22, the +60 degree direction carbon fiber prepreg 24, and the -60 degree direction carbon fiber prepreg 26 is one, but the number of laminated layers is one. In that case, the above-described lamination may be repeated.

Next, the laminate sandwiched between the molding plates 28 from above and below is heated under pressure to form an advanced grid structure with inserts. At this time, the molding temperature was 180 ° C. and the molding pressure was 300 kPa.
When heated under pressure in this way, as shown in FIG. 3 (b), the prepreg was pressurized by the molding pressure and the expansion of the silicone rubber 27, and was thermoset as shown in FIG. 3 (c).

A plurality of 0 degree direction carbon fiber tape prepregs 14 arranged in the first tape prepreg group, and a plurality of +60 degree direction carbon fiber tape prepregs 16 arranged in the second tape prepreg group, −60 degrees direction. A group in which a plurality of carbon fiber tape prepregs 18 are arranged is referred to as a third tape prepreg group.
Also, a plurality of 0 degree direction carbon fiber prepregs 22 arranged in the first prepreg group, a plurality of +60 degree direction carbon fiber prepregs 24 arranged in the second prepreg group, and a −60 degree direction carbon fiber prepreg 26 are arranged. Is a third prepreg group.

  At this time, a first grid side group that is in the same direction as the first tape prepreg group and constitutes one side of the grid group, and a second grid that is in the same direction as the second tape prepreg group and constitutes one side of the grid group Among the grid side groups, and the third grid side group that is in the same direction as the third tape prepreg group and constitutes one side of the grid group, the first grid side group, the second grid side group, and Since the regions where the third grid side groups intersect each other exist in the vicinity of each other, the equilateral triangular grid group composed of the three grid side groups is close to the carbon fiber reinforced plastic structure in which the carbon fibers are quasi-isotropically laminated. The carbon fiber reinforced plastic structure in which carbon fibers are quasi-isotropically laminated is found in the equilateral triangle grid group. Having an insert structure with a high pull-out strength by integrally molded embed partially over bets, and a structure having a low thermal expansion properties comparable to advanced grid structure and having a low thermal expansion properties.

FIG. 4 is a front view of the advanced grid structure with insert according to Embodiment 1 of the present invention.
The advanced grid structure with insert according to Embodiment 1 of the present invention uses a prepreg made by impregnating carbon fiber with a resin and then semi-cured, and orients the carbon fiber so as to face in the longitudinal direction. A strip-shaped tape prepreg composed of a prepreg of an epoxy resin reinforced with fiber and a prepreg of a fiber reinforced epoxy resin with carbon fibers oriented in the vicinity of the intersecting region of the tape prepreg and molded by heating under pressure Truss structure. As the carbon fiber, TORAYCA (registered trademark) yarn T800HB manufactured by Toray Industries, Inc., which is a high-strength type and has a tensile elastic modulus of 250 GPa or more and 350 GPa or less, is used.

The advanced grid structure with an insert according to the first embodiment of the present invention has a length direction in the vertical direction of the drawing on the drawing of FIG. 4 and is arranged in parallel at equal intervals in a first direction orthogonal to the length direction. A plurality of arranged grid sides (hereinafter referred to as “0 degree direction grid sides”) 1 intersect with each other at an angle of 60 degrees counterclockwise with respect to the 0 degree direction grid side 1 and arranged in parallel at equal intervals. A plurality of grid sides (hereinafter referred to as “+60 degree direction grid sides”) 2, a plurality of grid sides that intersect at an angle of 60 degrees with respect to the 0 degree direction grid side 1 and are arranged in parallel at equal intervals. (Hereinafter referred to as “−60 degree direction grid side”) 3.
The plurality of 0 degree direction grid sides 1 are the first grid side group, the plurality of +60 degree direction grid sides 2 are the second grid side group, and the plurality of −60 degree direction grid sides 3 are the third grid side group. Called.

In the advanced grid structure with an insert according to the first embodiment of the present invention, a regular triangular grid 4 and a hexagonal grid are formed by the 0 degree direction grid side 1, the +60 degree direction grid side 2, and the -60 degree direction grid side 3. 5 is formed.
In the advanced grid structure with an insert according to the first embodiment of the present invention, the insert member 6 having a pseudo isotropic laminated structure in which carbon fibers are oriented and laminated in the 0 degree direction, the +60 degree direction, and the -60 degree direction has the positive A part of the triangular grid 4 is integrally embedded. The insert member 6 has an insert hole 7.

FIG. 5 is an enlarged view including one insert member 6 of the advanced grid structure with insert according to Embodiment 1 of the present invention. The enlarged view shown in FIG. 5A is a view on the side of the coupling surface with the device and another structure. The enlarged view shown in FIG. 5B is a view on the side opposite to the coupling surface with the device and other structures.
As shown in FIG. 5, the 0 degree direction grid side 1 intersects the +60 degree direction grid side 2 and the −60 degree direction grid side 3 in the first intersection area 8 and the second intersection area 9, respectively. The +60 degree direction grid side 2 intersects the −60 degree direction grid side 3 in the third intersection region 10. It has been found that the presence of these intersecting regions 8, 9, and 10 in the vicinity of each other makes the equilateral triangular grid 4 have characteristics close to a structure in which carbon fibers are laminated in a pseudo isotropic manner. The third intersecting region 10 is a rhombus, and a center point where two diagonal lines of the rhombus intersect is referred to as a node 12. Further, the maximum value of the distance 11 between the intersecting regions 8 and 9 is a half value of the distance between the nodes 12.

  An insert member 6 having a structure in which carbon fibers provided with insert holes 7 are laminated in a pseudo isotropic manner is partially embedded in a 0 degree direction grid side 1, a +60 degree direction grid side 2, and a -60 degree direction grid side 3. Thus, it is integrally formed with a regular triangular grid 4. At this time, since the carbon fiber continuously exists so as to cross the interface between the insert member 6 and the equilateral triangle grid 4, the insert structure has a high pulling strength. Further, since the insert member 6 and the equilateral triangular grid 4 have substantially the same thermal expansion coefficient, the pullout strength is not lowered due to the thermal stress difference during molding.

FIG. 6 is an enlarged view including a regular triangular grid 4 and a hexagonal grid 5 of the advanced grid structure with insert according to the first embodiment of the present invention.
Here, two factors representing the structure of an advanced grid structure with an insert having an equilateral triangular grid 4 and a hexagonal grid 5 are introduced, and the thermal expansion coefficient of the equilateral triangular grid 4 and the factors The relationship with the thermal expansion coefficient of the advanced grid structure with inserts is obtained.
One factor to be introduced is a quotient obtained by dividing the grid-side width W by the distance L between the nodes 12 and is referred to as a structural ratio.
Another factor to be introduced is the distance a between the intersecting regions where the grid sides intersect. However, the distance a at this time is not less than 0 and not more than L / 2.

FIG. 7 is a cross-sectional view showing an apparatus for measuring the coefficient of thermal expansion of an equilateral triangular grid and an advanced grid structure with an insert.
Next, measurement of the thermal expansion coefficient of an equilateral triangular grid and an advanced grid structure with an insert will be described.
In the measurement of the thermal expansion coefficient of the equilateral triangular grid 4 and the advanced grid structure with insert, first, the advanced grid structure with insert as the measurement sample 29 is placed on the sample support 30 and fixed in the thermostat 31. To do.
Next, while controlling the temperature in the thermostatic chamber 31 to change the temperature of the measurement sample 29, the laser reflecting displacement meter 33 applies the laser reflecting mirror 32 adhered to both ends of the measurement sample 29 and the equilateral triangular grid portion. The laser is irradiated, the reflected light is received, the amount of displacement of the measurement sample 29 due to heating is measured, and the thermal expansion coefficient is calculated.

The distance a between the intersecting regions where the grid sides of the advanced grid structure with insert according to the first embodiment of the present invention intersect is 27 mm. Further, since the distance L between the nodes 12 is 105 mm and the width of the grid side is 1.60 mm, the structure ratio is 1.60 / 105 = 0.015. At this time, the thermal expansion coefficient of the measured equilateral triangular grid is 1.60 ppm / K, which is close to 0.93 ppm / K which is the thermal expansion coefficient of the carbon fiber reinforced plastic structure in which carbon fibers are laminated in a pseudo isotropic manner. Value.
Furthermore, the measured thermal expansion coefficient of the advanced grid structure with insert is 0.20 ppm / K in the X-axis direction and 0.0 ppm / K in the Y-axis direction.
Next, an advanced grid structure with an insert was manufactured by preparing a tape prepreg so that the distance a between the intersecting regions where the grid sides intersect was 27 mm and the distance L between the nodes 12 was different. At this time, the structural ratios were 1.60 / 105 = 0.015, 1.60 / 52.5 = 0.030, 1.60 / 26.25 = 0.060. The thermal expansion coefficient of this advanced grid structure with an insert was measured as shown in FIG.

FIG. 8 is a graph showing the thermal expansion coefficient with the structural ratio as the horizontal axis.
Next, the range in which the advanced grid structure with inserts is considered to have low thermal expansion as a satellite structure is defined. Generally, high strength carbon fiber and high elasticity carbon fiber exist in carbon fiber, but carbon fiber reinforced plastic structure using conventional carbon fiber laminated in quasi-isotropy using high elasticity carbon fiber. Can produce a coefficient of thermal expansion close to zero. This is because the carbon fiber reinforced plastic has a negative coefficient of thermal expansion in the direction of carbon fiber and a positive coefficient of thermal expansion in the direction orthogonal to the carbon fiber, so that the combination becomes near zero.
However, when this becomes a high-strength carbon fiber, since the tensile strength and tensile modulus of carbon fiber generally show an inversely proportional relationship, the tensile modulus decreases and the thermal expansion coefficient of the carbon fiber itself approaches zero. In the carbon fiber reinforced plastic structure in which carbon fibers are laminated in a pseudo isotropic manner, the thermal expansion coefficient cannot be made close to zero.
Therefore, here, a carbon fiber reinforced plastic structure in which conventional carbon fibers are laminated in a quasi-isotropic manner using Toray Co., Ltd. TORAYCA (registered trademark) yarn T1000G, which is currently the strongest carbon fiber, cannot be obtained. The thermal expansion coefficient is used as one criterion. At this time, since the thermal expansion coefficient of the carbon fiber reinforced plastic structure in which carbon fibers are laminated in a pseudo isotropic manner is 0.93 ppm / K, the range of structures having low thermal expansion in the advanced grid structure with an insert is the thermal expansion coefficient. Is a structure of −0.9 ppm / K or more and 0.9 ppm / K or less.

  The advanced grid structure with an insert according to Embodiment 1 of the present invention has three grid side groups in which the grid sides on which the carbon fibers are oriented in one direction are arranged at equal intervals. Since the remaining second grid side group and the third grid side group intersect with each other with an inclination of 60 degrees clockwise and counterclockwise with respect to the first grid side group, the grid side groups do not intersect each other. A structure in which carbon fibers are laminated in only one direction and an intersecting region where grid side groups intersect is formed.

  At this time, advanced having low thermal expansion characteristics by adjusting the ratio of the portion where the carbon fiber that is not intersecting the grid side group is laminated in only one direction and the intersecting region portion where the grid side group intersect is adjusted by the structural ratio In the grid structure, there is an area where the three grid side groups intersect each other so that an equilateral triangular grid group composed of the three grid side groups is a carbon fiber in which carbon fibers are laminated in a pseudo isotropic manner. High pull-out strength by embedding part of carbon fiber reinforced plastic structure with carbon fiber quasi-isotropically embedded in the equilateral triangle grid group because it has a structure close to that of reinforced plastic structure. The insert structure has a low residual thermal stress characteristic and has a low thermal expansion characteristic.

FIG. 8 is a graph showing the thermal expansion coefficient with respect to the structural ratio when the distance between the intersecting regions is 27 mm.
As can be seen from FIG. 8, using carbon fibers having a tensile modulus of 280 GPa or more and 330 GPa or less, the width W of the grid side or between the nodes 9 so that the structural ratio is greater than 0 and 0.089 or less. When the distance L is adjusted, an advanced grid structure with an insert having a thermal expansion coefficient of −0.9 ppm / K or more and 0.9 ppm / K or less can be obtained.

In the advanced grid structure with an insert according to the first embodiment of the present invention, an epoxy resin is impregnated in carbon fiber of Toray Industries, Inc. trading card (registered trademark) yarn T800HB having a tensile elastic modulus of 250 GPa or more and 350 GPa or less. A prepreg made by semi-curing after use is used, but the fiber is not limited to T800HB.
Further, the resin is not limited to the epoxy resin, and any resin can be applied to the present invention as long as the thermal mechanical chemical characteristics can withstand the use environment.
In the advanced grid structure with an insert according to the first embodiment of the present invention, the molding temperature is set to 180 degrees. However, any temperature can be used as long as the prepreg can be molded by heating under pressure. Can be appropriately set within a range of 280 degrees.
Moreover, although the pressure at the time of shaping | molding was 300 kPa, since it should just be a pressure which a prepreg can heat and shape | mold under pressure, it can set suitably in the range of 100 kPa to 1000 kPa.

Embodiment 2. FIG.
A method for manufacturing an advanced grid structure with inserts according to Embodiment 2 of the present invention will be described. First, a method for manufacturing the advanced grid structure will be described, and then a method for manufacturing the insert structure will be described.
FIG. 1 is a plan view of a tape prepreg for manufacturing an advanced grid structure in an advanced grid structure with an insert according to Embodiment 2 of the present invention.
Using Toray Industries, Inc. Torayca (registered trademark) yarn T800HB and an epoxy resin raw material, a strip-shaped tape prepreg in which carbon fibers are oriented in the length direction (vertical direction on the paper surface of FIG. 1A) is prepared. A carbon fiber tape prepreg 14 in which the carbon fibers as shown in FIG. 1A are oriented parallel to the reference side 13 and the carbon fibers as shown in FIG. +60 degree direction carbon fiber tape prepreg 16 oriented so as to incline 60 degrees in the direction, carbon fibers as shown in FIG. 3C were oriented so as to incline 60 degrees clockwise relative to the reference side 17. The advanced grid structure is manufactured by laminating the -60 degree direction carbon fiber tape prepreg 18 in order several times and heating under pressure.

  Separately, carbon fiber is simulated in 0 degree direction, +60 degree direction, and -60 degree direction by using GRANOC Yarn (registered trademark) XN90 manufactured by Nippon Graphite Fiber Co., Ltd. and epoxy resin raw material. The prepreg is laminated so as to be isotropic and heated under pressure to produce an insert member 34 having a carbon fiber reinforced plastic structure.

  FIG. 9 is an enlarged view for manufacturing an insert structure of an advanced grid structure with an insert according to Embodiment 2 of the present invention. An insert member 34 as shown in FIG. 9B is adhered to the space surrounded by the three grid sides of the regular triangular grid 4 of the advanced grid structure as shown in FIG. 9A. . 9B is a side of the connecting surface of the insert member 34 with the device and other structures, and FIG. 9C is a side opposite to the connecting surface of the insert member 34 with the device and other structures. Surface.

A plurality of 0 degree direction carbon fiber tape prepregs 14 arranged in the first tape prepreg group, and a plurality of +60 degree direction carbon fiber tape prepregs 16 arranged in the second tape prepreg group, −60 degrees direction. A group in which a plurality of carbon fiber tape prepregs 18 are arranged is referred to as a third tape prepreg group.
At this time, a first grid side group that is in the same direction as the first tape prepreg group and constitutes one side of the grid group, and a second grid that is in the same direction as the second tape prepreg group and constitutes one side of the grid group Among the grid side groups, and the third grid side group that is in the same direction as the third tape prepreg group and constitutes one side of the grid group, the first grid side group, the second grid side group, and Since the regions where the third grid side groups intersect each other exist in the vicinity of each other, the equilateral triangular grid group composed of the three grid side groups is close to the carbon fiber reinforced plastic structure in which the carbon fibers are quasi-isotropically laminated. The equilateral triangle grid group is found to have characteristics, and the carbon fiber having a lower thermal expansion coefficient than the equilateral triangle grid is pseudo-etc. A structure having an insert structure having a high pull-out strength by bonding the laminated carbon fiber reinforced plastic structure insert member 34 with an adhesive 36 and having a low thermal expansion characteristic equivalent to an advanced grid structure having a low thermal expansion characteristic; did.

FIG. 10 is a front view of an advanced grid structure with inserts according to Embodiment 2 of the present invention.
The insert member 34 is inserted into the space surrounded by the three grid sides of the equilateral triangular grid 4 of the advanced grid structure, and bonded with an adhesive 36. After bonding to the advanced grid structure, the insert member 34 is drilled to have an insert hole 35. In this way, the advanced grid structure with inserts according to Embodiment 2 of the present invention is manufactured.
The advanced grid structure with insert according to Embodiment 2 of the present invention uses a prepreg made by impregnating carbon fiber with a resin and then semi-cured, and orients the carbon fiber so as to face in the longitudinal direction. A strip-shaped tape prepreg made of fiber reinforced epoxy resin prepreg is laminated and heated under pressure to add a reinforced epoxy resin prepreg with oriented carbon fibers at the nodes of the truss structure. This is a structure in which an insert structure molded by heating under pressure is bonded. As carbon fiber, Toray Co., Ltd. TORAYCA (registered trademark) yarn T800HB having a tensile modulus of 250 GPa or more and 350 GPa or less is used for the tape prepreg, and Nippon Graphite Fiber Co., Ltd. has a tensile modulus of 810 GPa or more and 910 GPa or less. A GRANOC yarn (registered trademark) XN-90 manufactured by GRANOC is used.

  The advanced grid structure with insert according to the second embodiment of the present invention has a length direction in the vertical direction of the drawing on the drawing of FIG. 10 and is arranged in parallel at equal intervals in a first direction orthogonal to the length direction. A plurality of arranged grid sides (hereinafter referred to as “0 degree direction grid sides”) 1 intersect with each other at an angle of 60 degrees counterclockwise with respect to the 0 degree direction grid side 1 and arranged in parallel at equal intervals. A plurality of grid sides (hereinafter referred to as “+60 degree direction grid sides”) 2, a plurality of grid sides that intersect at an angle of 60 degrees with respect to the 0 degree direction grid side 1 and are arranged in parallel at equal intervals. (Hereinafter referred to as “−60 degree direction grid side”) 3. The plurality of 0 degree direction grid sides 1 are the first grid side group, the plurality of +60 degree direction grid sides 2 are the second grid side group, and the plurality of −60 degree direction grid sides 3 are the third grid side group. Called.

In the advanced grid structure with an insert according to the second embodiment of the present invention, an equilateral triangular grid 4 and a hexagonal grid are formed by the 0 degree direction grid side 1, the +60 degree direction grid side 2, and the -60 degree direction grid side 3. 5 is formed.
In the advanced grid structure with an insert according to the second embodiment of the present invention, the insert member 34 having a quasi-isotropic laminated structure in which carbon fibers are oriented and laminated in the 0 degree direction, the +60 degree direction, and the -60 degree direction includes Bonded to a triangular grid 4. The insert member 34 has an insert hole 35.

FIG. 11 is an enlarged view including one insert member 34 of the advanced grid structure with insert according to Embodiment 2 of the present invention. The enlarged view shown in FIG. 11A is a view on the side of the coupling surface with the device and another structure. The enlarged view shown in FIG. 11B is a view on the side opposite to the coupling surface with the device and other structures.
As shown in FIG. 11, the 0-degree direction grid side 1 intersects with the +60 degree direction grid side 2 and the −60 degree direction grid side 3 in the first intersection region 8 and the second intersection region 9, respectively. The +60 degree direction grid side 2 intersects the −60 degree direction grid side 3 in the third intersection region 10. It has been found that the presence of these intersecting regions 8, 9, and 10 in the vicinity of each other makes the equilateral triangular grid 4 have characteristics close to a structure in which carbon fibers are laminated in a pseudo isotropic manner. The third intersecting region 10 is a rhombus, and a center point where two diagonal lines of the rhombus intersect is referred to as a node 12. Further, the maximum value of the distance 11 between the intersecting regions 8 and 9 is a half value of the distance between the nodes 12.

  An insert member 34 having a structure in which carbon fibers having an insert hole 35 are laminated in a pseudo isotropic manner is constituted by a 0 degree direction grid side 1, a +60 degree direction grid side 2, and a −60 degree direction grid side 3. Bonded to the triangular grid 4. At this time, since the thermal expansion coefficient of the insert member 34 is set to a value lower than the thermal expansion coefficient of the equilateral triangular grid 4, the insert member 34 is restrained by the equilateral triangular grid 4 due to thermal deformation during molding. This insert structure has high pullout strength.

FIG. 12 is an enlarged view including a regular triangular grid 4 and a hexagonal grid 5 of the advanced grid structure with insert according to the first embodiment of the present invention.
Here, two factors representing the structure of an advanced grid structure with an insert having an equilateral triangular grid 4 and a hexagonal grid 5 are introduced, and the thermal expansion coefficient of the equilateral triangular grid 4 and the factors The relationship with the thermal expansion coefficient of the advanced grid structure with inserts is obtained.
One factor to be introduced is a quotient obtained by dividing the grid side width W by the distance L between the nodes 12 and is referred to as a structural ratio. Another factor to be introduced is the distance a between the intersecting regions where the grid sides intersect. However, the distance a at this time is not less than 0 and not more than L / 2.

Next, measurement of the thermal expansion coefficient of an equilateral triangular grid and an advanced grid structure with an insert will be described.
In the measurement of the thermal expansion coefficient of the equilateral triangular grid 4 and the advanced grid structure with insert, first, the advanced grid structure with insert as the measurement sample 29 is placed on the sample support 30 and fixed in the thermostat 31. To do. Next, while controlling the temperature in the thermostatic chamber 31 to change the temperature of the measurement sample 29, the laser reflecting displacement meter 33 applies the laser reflecting mirror 32 adhered to both ends of the measurement sample 29 and the equilateral triangular grid portion. The laser is irradiated, the reflected light is received, the amount of displacement of the measurement sample 29 due to heating is measured, and the thermal expansion coefficient is calculated.

  The distance a between the intersecting regions where the grid sides of the advanced grid structure with insert according to the second embodiment of the present invention intersect is 27 mm. Further, since the distance L between the nodes 12 is 105 mm and the width of the grid side is 1.60 mm, the structure ratio is 1.60 / 105 = 0.015. At this time, since the thermal expansion coefficient of the measured equilateral triangular grid is 1.60 ppm / K and the thermal expansion coefficient of the insert member 34 is −0.90 ppm / K, the insert member 34 is deformed due to thermal deformation during molding. Is constrained by an equilateral triangular grid. Furthermore, the measured thermal expansion coefficient of the advanced grid structure with insert is 0.20 ppm / K in the X-axis direction and 0.0 ppm / K in the Y-axis direction.

  Next, an advanced grid structure with an insert was manufactured by preparing a tape prepreg so that the distance a between the intersecting regions where the grid sides intersect was 27 mm and the distance L between the nodes 12 was different. At this time, the structural ratios were 1.60 / 105 = 0.015, 1.60 / 52.5 = 0.030, 1.60 / 26.25 = 0.060. The thermal expansion coefficient of this advanced grid structure with an insert was measured as shown in FIG.

FIG. 13 is a graph showing the thermal expansion coefficient with the structural ratio as the horizontal axis.
Next, the range in which the advanced grid structure with inserts is considered to have low thermal expansion as a satellite structure is defined.
Generally, high strength carbon fiber and high elasticity carbon fiber exist in carbon fiber, but carbon fiber reinforced plastic structure using conventional carbon fiber laminated in quasi-isotropy using high elasticity carbon fiber. Can produce a coefficient of thermal expansion close to zero. This is because the carbon fiber reinforced plastic has a negative coefficient of thermal expansion in the direction of carbon fiber and a positive coefficient of thermal expansion in the direction orthogonal to the carbon fiber, so that the combination becomes near zero.

However, when this becomes a high-strength carbon fiber, since the tensile strength and tensile modulus of carbon fiber generally show an inversely proportional relationship, the tensile modulus decreases and the thermal expansion coefficient of the carbon fiber itself approaches zero. In the carbon fiber reinforced plastic structure in which carbon fibers are laminated in a pseudo isotropic manner, the thermal expansion coefficient cannot be made close to zero.
Therefore, here, a carbon fiber reinforced plastic structure in which conventional carbon fibers are laminated in a quasi-isotropic manner using Toray Co., Ltd. TORAYCA (registered trademark) yarn T1000G, which is currently the strongest carbon fiber, cannot be obtained. The thermal expansion coefficient is used as one criterion.
At this time, since the thermal expansion coefficient of the carbon fiber reinforced plastic structure in which carbon fibers are laminated in a pseudo isotropic manner is 0.93 ppm / K, the range of structures having low thermal expansion in the advanced grid structure with an insert is the thermal expansion coefficient. Is a structure of −0.9 ppm / K or more and 0.9 ppm / K or less.

  The advanced grid structure with an insert according to the second embodiment of the present invention has three grid side groups in which the grid sides on which the carbon fibers are oriented in one direction are arranged at equal intervals. Since the remaining second grid side group and the third grid side group intersect with each other with an inclination of 60 degrees clockwise and counterclockwise with respect to the first grid side group, the grid side groups do not intersect each other. A structure in which carbon fibers are laminated in only one direction and an intersecting region where grid side groups intersect is formed.

  At this time, advanced having low thermal expansion characteristics by adjusting the ratio of the portion where the carbon fiber that is not intersecting the grid side group is laminated in only one direction and the intersecting region portion where the grid side group intersect is adjusted by the structural ratio In the grid structure, there is an area where the three grid side groups intersect each other so that an equilateral triangular grid group composed of the three grid side groups is a carbon fiber in which carbon fibers are laminated in a pseudo isotropic manner. Since the structure has a characteristic close to that of a reinforced plastic structure, an insert member 34 having a carbon fiber reinforced plastic structure in which carbon fibers are quasi-isotropically laminated with a lower coefficient of thermal expansion than that of the regular triangle grid. By bonding, it has an insert structure with high pullout strength and low thermal expansion characteristics.

FIG. 13 is a graph showing the thermal expansion coefficient with respect to the structural ratio when the distance between the intersecting regions is 27 mm.
As can be seen from FIG. 13, using carbon fibers having a tensile modulus of 280 GPa or more and 330 GPa or less, the width W of the grid side or between the nodes 9 so that the structural ratio is greater than 0 and 0.089 or less. When the distance L is adjusted, an advanced grid structure with an insert having a thermal expansion coefficient of −0.9 ppm / K or more and 0.9 ppm / K or less can be obtained.

In the advanced grid structure with an insert according to the second embodiment of the present invention, the carbon fiber of the Toray Industries, Inc. trading card (registered trademark) yarn T800HB having a tensile elastic modulus of 250 GPa or more and 350 GPa or less and the tensile elastic modulus of 810 GPa or more In addition, a prepreg made by impregnating an epoxy resin into a carbon fiber of GRANOC Yarn (registered trademark) XN-90 manufactured by Nippon Graphite Fiber Co., Ltd. of 910 GPa or less is used, but the fiber is T800HB or XN- It is not limited to 90.
Further, the resin is not limited to the epoxy resin, and any resin can be applied to the present invention as long as the thermal mechanical chemical characteristics can withstand the use environment.

Embodiment 3 FIG.
In the advanced grid structure with an insert according to the third embodiment of the present invention, a process of integrally forming the invar alloy plate 37 inside the insert member will be described.
A carbon fiber prepreg 22 in which the carbon fibers as shown in FIG. 14A are oriented parallel to the reference side 21 and the carbon fibers as shown in FIG. 14B are counterclockwise with respect to the reference side 23. The carbon fiber prepreg 24 in the +60 degree direction oriented so as to incline at 60 degrees, and the carbon fiber as shown in FIG. 14C oriented at 60 degrees in the clockwise direction with respect to the reference side 25. Three tapes are formed in the gathering region formed by stacking the degree direction carbon fiber prepreg 26 in order, the zero degree direction carbon fiber tape prepreg 14, the +60 degree direction carbon fiber tape prepreg 16, and the -60 degree direction carbon fiber tape prepreg 18. When laminating a plurality of times alternately with the prepreg, a single Invar alloy plate 37 as shown in FIG. 14 (d) is laminated and heated under pressure. And, by machining the screw holes 38 in the insert member 34, the insert structure of the insert with the advanced grid structure according to the third embodiment of the present invention is manufactured.

15 and 16 are cross-sectional views seen from the side of the insert structure of the advanced grid structure with insert according to Embodiment 3 of the present invention. 15 is a cross-sectional view seen from the side of the insert structure when the insert structure of the first embodiment is used, and FIG. 16 is a cross-section seen from the side of the insert structure when the insert structure of the second embodiment is used. FIG.
As shown in FIG. 15, the advanced grid structure with insert according to Embodiment 3 of the present invention has insert holes 7 and 35 of the advanced grid structure with insert according to Embodiment 1 and Embodiment 2 of the present invention. Is formed into an insert screw hole 38 by machining a screw hole into an insert member integrally formed with an Invar alloy plate 37 having a low thermal expansion coefficient.

  The advanced grid structure with an insert according to the third embodiment of the present invention has the ratio of the intersection region portion of the grid side and the portion where the grid side does not intersect, as in the first and second embodiments of the present invention. Invar alloy with a lower coefficient of thermal expansion than metal materials such as aluminum and titanium in the insert structure with high pullout strength provided in advanced grid structure with low thermal expansion coefficient by adjusting integrally in the insert member Then, by processing the screw holes, the positional accuracy at the time of joining with the device or another structure becomes high accuracy.

In the advanced grid structure with insert which concerns on Embodiment 1 of this invention, it is a top view of the tape prepreg for manufacturing an advanced grid structure. In the advanced grid structure with insert which concerns on Embodiment 1 of this invention, it is a top view of the prepreg for manufacturing an insert structure. It is sectional drawing of the prepreg for manufacturing the advanced grid structure with an insert which concerns on Embodiment 1 of this invention. It is a front view of the advanced grid structure with insert which concerns on Embodiment 1 of this invention. It is an enlarged view containing the grid of one equilateral triangle of the advanced grid structure with insert which concerns on Embodiment 1 of this invention. It is an enlarged view including the equilateral triangular grid and hexagonal grid of the advanced grid structure with insert which concerns on Embodiment 1 of this invention. In the advanced grid structure with insert which concerns on Embodiment 1 of this invention, it is sectional drawing which shows the measurement apparatus of the thermal expansion coefficient of a regular triangular grid and the advanced grid structure with insert. It is a graph showing the thermal expansion coefficient of the advanced grid structure with insert according to Embodiment 1 of the present invention with the structural ratio as the horizontal axis. It is an enlarged view for manufacturing the insert structure of the advanced grid structure with insert which concerns on Embodiment 2 of this invention. It is a front view of the advanced grid structure with insert which concerns on Embodiment 2 of this invention. It is an enlarged view including the grid of one equilateral triangle of the advanced grid structure with insert which concerns on Embodiment 2 of this invention. It is an enlarged view including the equilateral triangular grid and hexagonal grid of the advanced grid structure with insert which concerns on Embodiment 2 of this invention. It is a graph showing the thermal expansion coefficient of the advanced grid structure with insert according to Embodiment 2 of the present invention, with the structural ratio as the horizontal axis. In the advanced grid structure with insert which concerns on Embodiment 3 of this invention, it is a top view of the prepreg for manufacturing an insert structure. It is sectional drawing seen from the side surface of the insert structure of the advanced grid structure with insert which concerns on Embodiment 3 of this invention. It is sectional drawing seen from the side surface of the other insert structure of the advanced grid structure with insert which concerns on Embodiment 3 of this invention.

Explanation of symbols

  10 degree grid side, 2 +60 degree direction grid side, 3-60 degree direction grid side, 4 equilateral triangle grid, 5 hexagonal grid, 6 insert member, 7 insert hole, 8 first intersecting region, 9 Second intersection area, 10 Third intersection area, 11 Distance between intersection areas, 12 nodes, 13 reference side, 140 degree direction carbon fiber tape prepreg, 15 reference side, 16 + 60 degree direction carbon fiber tape prepreg, 17 reference side, 18-60 degree direction carbon fiber prepreg, 19 equilateral triangle region, 20 gathering region, 21 reference side, 220 degree direction carbon fiber prepreg, 23 reference side, 24 + 60 degree direction carbon fiber prepreg, 25 reference side 26-60 degree carbon fiber prepreg, 27 Silicone rubber, 28 Molded plate, 29 Measuring sun Pull, 30 Sample support base, 31 Thermostatic bath, 32 Laser reflector, 33 Laser focus displacement meter, 34 Insert member, 35 Insert hole, 36 Adhesive, 37 Invar alloy plate, 38 Insert screw hole.

Claims (3)

First tape prepreg group in which carbon fibers arranged at equal intervals in the first direction are oriented in the longitudinal direction, etc. in a second direction inclined 60 degrees counterclockwise with respect to the first direction, etc. Second tape prepreg group in which carbon fibers arranged at intervals are oriented in the longitudinal direction, and carbon arranged at equal intervals in a third direction inclined 60 degrees clockwise with respect to the first direction The third tape prepreg group in which the fibers are oriented in the longitudinal direction are laminated in order so that the two tape prepreg groups overlap each other and the three tape prepreg groups do not overlap at the same position. In the shape of the gathering region excluding the cross region of the tape prepreg from the equilateral triangle region composed of the tape prepreg, the second tape prepreg and the third tape prepreg, the first direction A first prepreg sheet group in which carbon fibers are oriented in one direction, and a second prepreg sheet group in which carbon fibers are oriented in one direction in a second direction inclined 60 degrees counterclockwise with respect to the first direction. A prepreg sheet group and a third prepreg sheet group in which carbon fibers are oriented in one direction in a third direction inclined 60 degrees clockwise with respect to the first direction are sequentially stacked in the assembly region. In an advanced grid structure with an insert formed by being heated under pressure and drilled in an insert member surrounded by three grid side groups,
A first grid side group that is in the same direction as the first tape prepreg group and constitutes one side of the grid group, and a second grid that is in the same direction as the second tape prepreg group and constitutes one side of the grid group Among the grid side group and the third grid side group that is in the same direction as the third tape prepreg group and constitutes one side of the grid group, the second grid side group and the third grid side group The grid side width is divided by the distance between the center point of the region where the crossing and the center point of the region where the second grid side group closest to the crossing region intersects the third grid side group. as well as the structure ratio obtained is larger and 0.089 or less than 0 Te, three of said insert member is a carbon fiber reinforced flop surrounded by the grid side group By a stick structure, the insert with the advanced grid structure, characterized in that the thermal expansion coefficient is not more than -0.9 ppm / K or more and 0.9 ppm / K. First tape prepreg group in which carbon fibers arranged at equal intervals in the first direction are oriented in the longitudinal direction, etc. in a second direction inclined 60 degrees counterclockwise with respect to the first direction, etc. Second tape prepreg group in which carbon fibers arranged at intervals are oriented in the longitudinal direction, and carbon arranged at equal intervals in a third direction inclined 60 degrees clockwise with respect to the first direction The third tape prepreg group in which the fibers are oriented in the longitudinal direction is laminated in order so that the two tape prepreg groups overlap each other and the three tape prepreg groups do not overlap at the same position, and are heated under pressure. In the space of the equilateral triangle surrounded by the three grid side groups of the advanced grid structure formed by the carbon fiber in the equilateral triangular prism shaped mold in the 0 degree direction, +60 degree direction, -60 degree direction, etc. The insert member of the molded carbon fiber reinforced plastic structures bonded with adhesive, in a hole machined advanced grid structure with insert in the insert member by heating at by laminating prepregs under pressure so that,
A first grid side group that is in the same direction as the first tape prepreg group and constitutes one side of the grid group, and a second grid that is in the same direction as the second tape prepreg group and constitutes one side of the grid group Among the grid side group and the third grid side group that is in the same direction as the third tape prepreg group and constitutes one side of the grid group, the second grid side group and the third grid side group The grid side width is divided by the distance between the center point of the region where the crossing and the center point of the region where the second grid side group closest to the crossing region intersects the third grid side group. as well as the structure ratio obtained is larger and 0.089 or less than 0 Te, against the space of an equilateral triangle which insert is surrounded by three grid side group A carbon fiber reinforced plastic structure having a thermal expansion coefficient lower than that of the regular triangular structure having a thermal expansion coefficient of −0.9 ppm / K or more and 0.9 ppm / K or less. Advanced grid structure with insert.   The advanced grid structure with an insert according to any one of claims 1 to 2, wherein the hole of the insert member is processed so as to be a highly accurate screw hole with a high positional accuracy.

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