JP4241984B2 - Structural member and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structural member using a fiber reinforced plastic and a manufacturing method thereof.
[0002]
[Prior art]
Attempts have been made to manufacture structural members for use in building truss members, space structural members, and the like using fiber reinforced plastics. FIG. 5 shows a conventional structural member, and its structure will be described together with a manufacturing method.
[0003]
As the structural member 1, a filament winding method or a drawing method is known as a method for producing a hollow structural member 2 made of fiber reinforced plastic.
[0004]
In the filament winding method, thread fibers are immersed in an uncured thermosetting resin so that the fibers contain the uncured resin, and then wound around the outer peripheral surface of a cylindrical mandrel (not shown). For example, it is cured by heating in an electric furnace. The mandrel is pulled out from the inside of the cylindrical hollow structural member 2 obtained by curing the uncured resin or is used as the structural truss member for space or the structural member 1 for space. FIG. 5 shows a state where the mandrel is pulled out.
[0005]
In the drawing method, for example, fibers aligned in parallel on the circumference are passed through a die of an extruder, uncured resin is supplied to the portion where the fibers are arranged, and heated in the die for a predetermined time. The resin is cured to form the hollow structural member 2. In this drawing method, since the cylindrical hollow structure member 2 can be continuously manufactured, it is not necessary to pull out the mandrel after forming.
[0006]
After manufacturing the hollow structural member 2 in this way, the end joint fitting 3 is attached to the open end of the hollow structural member 2. For attaching the end joint fitting 3, first, holes for driving the rivets 4 are formed in both the open end side of the hollow structural member 2 and the mandrel fitting portion 3a of the end joint fitting 3, and these holes are mutually connected. After confirming the alignment of the holes, the rivet 4 is driven to complete the attaching operation of the end joint fitting 3. Further, the end joint fitting 3 can be obtained a structural member 1 that can be connected to another structural member 1 via a fitting such as a node 5.
[0007]
By the way, the hollow structural member 2 made of the fiber reinforced plastic configured as described above has high strength and it is difficult to make a hole. This is because fiber reinforced plastic has high strength and contains carbon fibers and aramid fibers depending on the application, so it is difficult to originally drill holes, and the fibers are bonded only by resin. Therefore, cracks along the fiber may occur during the drilling process, making the process difficult.
[0008]
Therefore, the present applicant has already filed an application as Japanese Patent Application No. 10-329740 in order to solve the above-described problems. This is because a plurality of protrusions are provided on the outer peripheral surface of the end joint fitting, and when the uncured fiber reinforced plastic is wound around the mandrel, the protrusion is also wound on the outer peripheral surface of the end joint fitting. Bites into uncured fiber reinforced plastic and engages when the fiber reinforced plastic is cured. According to this method, there is no need to make holes in the fiber-reinforced plastic after curing, and it is easy to manufacture, and there is an effect that cracks and the like along the fibers do not occur during the drilling process.
[0009]
[Problems to be solved by the invention]
However, although the prior application Japanese Patent Application No. 10-329740 is easy to manufacture, the mandrel used when winding the uncured fiber reinforced plastic cannot be extracted and remains in the product. Further, there is a problem in that the weight of the hollow structural member is increased, handling becomes difficult, and the cost is increased.
[0010]
This invention has been made by paying attention to the above circumstances, and its purpose is to easily manufacture a hollow structural member, and to extract a mandrel used when winding fiber-reinforced plastic, It is an object of the present invention to provide a structural member that can be reduced in weight and cost and a method for manufacturing the structural member.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a hollow structural member having openings at both ends formed by hardening a fiber reinforced plastic wound around a mandrel and then extracting the mandrel, and an outer periphery of one end. A cylindrical first member having a plurality of protrusions spaced in the circumferential direction on the surface, the one end portion being fixed by biting into the end portion of the hollow structural member, and the other end portion having a screw portion. An end joint member and a threaded portion that is screwed into the threaded portion of the first end joint member, and is coupled to close the opening of the first end joint member. An end joint member, and a hole penetrating in a radial direction provided in a peripheral wall corresponding to the thread portion of the first end joint member. The thread portion of the first end joint member and the second end joint member By filling the hole with an adhesive with the threaded portion of the end joint member screwed together. , In the structural member, characterized by comprising a coupling portion for coupling the first of the the end fitting member second end fitting member.
[0012]
Claim 2 is an end joint member having a plurality of projections on the outer peripheral surface of the end portion of the mandrel formed in the same outer diameter over the entire length, and having a plurality of protrusions spaced circumferentially on the outer peripheral surface. A first step of locking the mandrel and the end joint member so as not to be axially and circumferentially movable, and an end joint member having uncured fiber reinforced plastic having the protrusions. A second step of winding the outer surface of the mandrel; a third step of curing the uncured fiber-reinforced plastic to form a hollow structural member having the end joint member; and the mandrel and the end 4th process which cancels | releases a lock | rock with a part joint member, and extracts the said mandrel from the hollow structure member provided with the said end part joint member, The said edge part obtained through the 4th process from the said 1st process Hollow structure with joint members Preparing a plurality of members, butting the end joint members together, and positioning the plurality of hollow structural members coaxially; and a heat shrink tape on the outer peripheral surface of the uncured fiber-reinforced plastic And a sixth step of heat-curing the fiber-reinforced plastic in a wound state.
[0016]
According to the first and second aspects, a hollow structural member in which the protrusion provided on the end joint member bites into the fiber reinforced plastic can be formed by curing the uncured fiber reinforced plastic . By extracting a mandrel from the hollow structural member, a hollow structural member provided with the end joint member can be obtained, and a plurality of hollow structural members provided with the end joint member are prepared, and the end joint members are By aligning the plurality of hollow structural members coaxially, the work of winding the heat-shrinkable tape around the outer peripheral surface of the uncured fiber reinforced plastic can be performed continuously, and the work efficiency can be improved. In addition, the heat-shrinkable tape is contracted so that the fiber-reinforced plastic can be brought into close contact with the mandrel and the end joint member.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
1 to 3 show a first embodiment, and FIG. 1 shows a structural member 11 used as a building truss member or a structural member for space. The structural member 11 includes a cylindrical hollow structural member 12, a first end joint member 13 provided at an end of the hollow structural member 12, and a second end joint member 13 coupled to the first end joint member 13. End joint member 14.
[0022]
Next, the structural member 11 will be described with reference to FIG. For example, a cylindrical or columnar mandrel 15 made of aluminum has a length corresponding to the length of the hollow structural member 12 to be molded, and a first end joint member is provided at one end of the mandrel 15. 13 can be externally fitted.
[0023]
The first end joint member 13 has a small-diameter cylindrical portion 16 on one end side and a large-diameter cylindrical portion 17 on the other end side, and the small-diameter cylindrical portion 16 is formed with an inner diameter that fits closely to the mandrel 15. The large diameter cylindrical portion 17 is formed to have an inner diameter larger than that of the mandrel 15. Furthermore, an internal thread portion 18 having an inner diameter larger than the outer diameter of the mandrel 15 is formed on the inner peripheral surface of the large diameter cylindrical portion 17.
[0024]
Further, on the outer peripheral surface of the small-diameter cylindrical portion 16 of the first end joint member 13, an engaging portion 19 made of protrusions provided at equal intervals in the circumferential direction is provided. Further, a small-diameter insertion hole 20 is formed in a part of the large-diameter cylindrical portion 17 through the female screw portion 18 in the radial direction, and the mandrel 15 has a lock hole 21 having the same diameter corresponding to the insertion hole 20. It has been drilled. The first end joint member is inserted into the lock hole 21 through the insertion hole 20 from the outside of the first end joint member 13 to insert the fixing pin 22 as a temporary fixing member into the mandrel 15. 13 can be locked in the axial direction and circumferential direction. The insertion hole 20 and the lock hole 21 may be provided at one place or a plurality of places on the circumference.
[0025]
Further, an annular groove 23 as a coupling portion is provided on the outer peripheral surface on the end portion side of the large-diameter cylindrical portion 17 of the first end joint member 13, as shown in FIG. When the end joint member 13 is coaxially butted together with the mandrel 15, the end joint member 13 is engaged with a clamp ring 24 as a connecting member that couples both the first end joint members 13.
[0026]
That is, when the mandrels 15 to which the first end joint members 13 are attached are abutted with each other, a gap 25 is formed between the first end joint members 13, and a ring-shaped spacer 26 is inserted into the mandrel 15 in the gap 25. It is provided in a state of being externally fitted. Furthermore, the first end joint member 13 can be coupled to each other by fitting the clamp ring 24 to the outside of the spacer 26 and engaging the annular protrusions 24a at both ends of the clamp ring 24 with the annular groove 23. It has become. The clamp ring 24 may be formed of a flexible material and may be attached from the axial direction of the first end joint member 13. The clamp ring 24 may be divided into two rings from the radial direction of the first end joint member 13. You may wear it.
[0027]
Next, a manufacturing method for manufacturing the structural member 11 will be described.
[0028]
First, after fitting the first end joint member 13 to the end of the mandrel 15 and aligning the insertion hole 20 and the lock hole 21, the fixing pin 22 is inserted into the lock hole 21 from the insertion hole 20. The first end joint member 13 is locked against the mandrel 15 so as not to move in the axial direction and the circumferential direction.
[0029]
Next, the prepreg 30 that is an uncured fiber reinforced plastic such as carbon fiber or aramid fiber is wound around the outer peripheral surface of the mandrel 15, and the outer peripheral surface of the small-diameter cylindrical portion 16 of the first end joint member 13 is also wound. Wind. At this time, in the first stage of winding the prepreg 30 around the outer peripheral surface of the small-diameter cylindrical portion 16, the prepreg 30 is wound around the engagement portion 19, and in the last stage, the engagement portion 19 is wound so as to be covered with the prepreg 30. As a result, the prepreg 30 is engaged with the engaging portion 19 and is buried. The prepreg 30 may be formed by filament winding or autoclave molding (for example, sheet winding).
[0030]
Next, two prepregs 30 wound around the mandrel 15 and the small-diameter cylindrical portion 16 of the first end joint member 13 (hereinafter referred to as semi-finished products) are prepared, and the first end joint member 13 is used as the mandrel. 15 and coaxially butt. Then, the spacer 26 is set in a state in which the spacer 26 is externally fitted to the mandrel 15 in the gap 25 formed between the first end joint members 13. Further, the clamp ring 24 is fitted to the outer side of the spacer 26, and the annular protrusions 24a at both ends of the clamp ring 24 are engaged with the annular groove 23 of the first end joint member 13 so that the first end of the semi-finished product is obtained. The joint members 13 are coupled to each other.
[0031]
In this state, the heat shrink tape 31 is wound around the outer peripheral surface of the semi-finished prepreg 30 in a spiral shape. At this time, since the two semi-finished products are coaxially coupled, the work of winding the heat shrink tape 31 can be continuously performed, and it is efficient whether it is wound by an automatic tape winding machine or manually. It is.
[0032]
Next, the heat shrinkable tape 31 is cut in the vicinity of the outer peripheral surface of the clamp ring 24 to which the semi-finished products are connected. Then, the clamp ring 24 is removed, and the spacer 26 is also detached to separate the first end joint members 13 from each other, and the end portions of the heat shrink tape 31 are processed and fixed so that the winding cannot be unwound.
[0033]
Next, the prepreg 30 around which the heat-shrinkable tape 31 is wound is placed in a heating furnace with the mandrel 15 and the first end joint member 13 and heated for a predetermined time, whereby the prepreg 30 is heat-cured to form the hollow structural member 12. Form. At this time, since the engaging portion 19 is buried and engaged in the prepreg 30 and the heat shrinkable tape 31 is contracted by heating, the small diameter cylindrical portion of the mandrel 15 and the first end joint member 13 is attached to the prepreg 30. 16 can be brought into close contact with the outer peripheral surface.
[0034]
Even when the resin is not thermosetting but thermoplastic, a truss-like member can be formed by the same process. Further, when the resin is ultraviolet curable, an ultraviolet curing furnace can be used instead of a heating furnace. Even in this case, since it can be used in combination with a heating furnace, it is possible to obtain a manufacturing effect by applying pressure to the product by shrinking the heat shrinkable tape.
[0035]
After the hollow structural member 12 is completed, the heat shrink tape 31 is unwound, the fixing pin 22 is removed from the lock hole 21 and the insertion hole 20, and the mandrel 15 and the first end joint member 13 are separated, and the mandrel 15 is hollow. Extract from structural member 12.
[0036]
Next, the first and second end joint members 13 and 14 are coupled by screwing the male thread portion 32 of the second end joint member 14 into the female thread portion 18 of the first end joint member 13. Furthermore, the first and second end joint members 13 and 14 can be firmly joined by filling the insertion hole 20 and the lock hole 21 opened by removing the fixing pin 22 with the adhesive 33, and the structure The member 11 is completed.
[0037]
The second end joint member 14 is provided with a bolt 34 protruding in the axial direction, and a node 35 can be attached to the bolt 34. By attaching another structural member or the like to the node 35, a construction can be performed. Truss structure for space, structural members for space, etc. can be constructed.
[0038]
Reference numeral 36 denotes a collar. The bolt 34 is not removed from the second end joint member 14 before the truss is assembled to the node 35, and the bolt 34 is turned from the outside when the bolt 34 is screwed into the node 35. And a function of transmitting a compressive force from the node 35 to the truss member in an assembled state. The collar 36 can take any number of forms, but any form does not affect the essence of the invention.
[0039]
FIG. 4 shows a second embodiment, and the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, a male screw portion 39 is provided on the outer peripheral surface of the large-diameter cylindrical portion 38 of the first end joint member 37, and a female screw portion 42 is provided on the inner peripheral surface of the cylindrical portion 41 of the second end joint member 40. It is provided and coupled to the male screw portion 39 by screwing.
[0040]
In addition, in the said embodiment, although the hollow structure member was formed in the cylindrical shape, it is not limited to a cylindrical shape, For example, you may form in other shapes, such as a polygonal cylinder shape.
[0041]
【The invention's effect】
As described above, according to the first and second aspects, the hollow structure member in which the protrusion provided on the end joint member bites into the fiber reinforced plastic can be formed by curing the uncured fiber reinforced plastic. it can. It is possible to reduce the weight by Rukoto from the hollow structural member sampling the mandrel. Furthermore, by preparing a plurality of hollow structural members provided with end joint members, butting the end joint members together, and positioning the plurality of hollow structural members coaxially, the outer peripheral surface of the uncured fiber reinforced plastic The work of wrapping the heat-shrink tape around can be performed continuously, and the work efficiency can be improved. In addition, there is an effect that the heat-shrinkable tape is contracted so that the fiber reinforced plastic can be brought into close contact with the mandrel and the end joint member.
[Brief description of the drawings]
FIG. 1 is a half longitudinal side view of a structural member showing a first embodiment of the present invention.
FIG. 2 is a half longitudinal side view showing the same embodiment, with a prepreg wound around a mandrel.
FIG. 3 is a half vertical side view showing the embodiment and showing a state in which a heat-shrink tape is wound around a prepreg.
FIG. 4 is a half longitudinal side view of a structural member showing a second embodiment of the present invention.
FIG. 5 is a half vertical side view of a conventional structural member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Structural member 12 ... Hollow structural member 13 ... 1st end joint member 14 ... 2nd end joint member 15 ... Mandrel 19 ... Engagement part 22 ... Fixing pin (temporary fixing member)
30 ... Prepreg (fiber reinforced plastic)
31 ... heat shrink tape

Claims (2)

After curing the fiber reinforced plastic wound around the mandrel, the hollow structural member with both ends opened by extracting the mandrel;
A cylinder having a plurality of protrusions spaced on the outer peripheral surface of one end portion in the circumferential direction, the one end portion being fixed by biting into the end portion of the hollow structural member, and a screw portion at the other end portion A first end joint member having a shape;
A second end joint member having a threaded portion that is threadedly engaged with a threaded portion of the first end joint member, and coupled to close an opening of the first end joint member;
It consists of a hole penetrating in the radial direction provided in the peripheral wall corresponding to the threaded portion of the first end joint member, and the threaded portion of the first end joint member and the screw of the second end joint member In a state where the parts are screwed together, a coupling part for coupling the first end joint member and the second end joint member by filling the hole with an adhesive,
The structural member characterized by comprising . While fitting an end joint member having a plurality of protrusions on the outer peripheral surface of the mandrel formed at the same outer diameter over the entire length and having a cylindrical shape with a space in the circumferential direction. A first step of locking the mandrel and the end joint member in an axially and circumferentially immovable manner;
A second step of winding uncured fiber-reinforced plastic around the outer surface of the mandrel including the end joint member having the protrusion;
A third step of curing the uncured fiber reinforced plastic and forming a hollow structural member provided with the end joint member;
A fourth step of releasing the lock between the mandrel and the end joint member, and extracting the mandrel from a hollow structural member provided with the end joint member;
A plurality of hollow structural members provided with the end joint members obtained through the first step to the fourth step are prepared, the end joint members are butted together, and the plurality of hollow structural members are coaxial. A fifth step of automatically positioning;
A sixth step of heat-curing the fiber-reinforced plastic in a state where a heat-shrink tape is wound around the outer peripheral surface of the uncured fiber-reinforced plastic;
The manufacturing method of the structural member characterized by comprising.

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