JP3224006B2 - Tubular body and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tubular body which does not easily bend and deform in response to a change in temperature, and a method for manufacturing the same. Therefore, it can be used for fishing rod rod tubes, golf club shafts, ski poles, bicycle frames, tennis and badminton rackets, and the like.

[0002]

2. Description of the Related Art In a method of forming a tubular body by winding a material sheet around a cored bar, the tightening pressure of a cellophane tightening tape causes the aligned fibers to bend at the time of thermoforming, resulting in a product defect or a sheet polymerization. The uniform thickness cannot be obtained due to the formation of the portion, and the tubular material is bent during the heat molding. The method of solving these problems is disclosed in Japanese Patent Application Laid-Open No. Sho 56-68331 and Japanese Patent Publication No. Sho 62-30095. Have been.

[0003] The former discloses a method of forming a fishing rod rod tube by winding a prepreg sheet in which a scrim cloth is bonded to a carbon fiber aligned sheet on a cored bar. The latter includes a plurality of continuous warps radially arranged with respect to the cored bar, a warp which is radially arranged so as to fill a gap between the warp yarns, and is cut by at least two units. A technique is disclosed in which a woven fabric is woven with a plurality of continuous weft yarns orthogonal to each other on the basis of a core metal, and the woven fabric is simultaneously woven in multiple layers to form a material.

[0004]

However, in the former method, although the movement of the aligned fibers can be prevented by pressing the aligned sheet with a scrim cloth, the movement of the entire prepreg sheet during the heat molding with respect to the core metal or the movement of the core metal can be prevented. Tapered shape,
It is not possible to prevent the fiber direction from being inclined with respect to the core metal direction due to the overlap portion of the sheet or the like, and it is impossible to prevent the uneven thickness portion from being formed, and there is a limit to preventing the rod tube that has been heated and fired from bending. In the latter, a fabric is woven on the basis of the core metal and molded so as to have a uniform thickness on the circumference, and a method of forming a tubular body by winding a material sheet or material tape around the core metal. In contrast, manufacturing is not always easy.

[0005] Accordingly, the present invention balances the bending moment caused by a temperature change due to the uneven thickness of the tubular body and the inclination of the reinforcing fiber in the tubular body, thereby preventing bending of the product and facilitating manufacture. The purpose is to.

[0006]

SUMMARY OF THE INVENTION In view of the above objects, the present invention provides a tubular body reinforced by a reinforcing fiber using a synthetic resin as a matrix according to claim 1 and comprising a sheet-like material.
The main body portion is formed by winding a prepreg, and the cross section in the direction including the circumference of the tubular body has an asymmetric structure, and the longitudinal elastic modulus in the axial length direction of the tubular body in the asymmetric structure cross section. And the linear expansion coefficient in the axial direction, and a predetermined position of the cross-section so as to cancel the moment of bending the tubular body along the axial direction based on the temperature change.
Place another sheet-like prepreg on the
A tubular body characterized by the following. Here, the cross section is an asymmetric structure, in the case of a cross section structure having an overlapping portion of a winding end portion by winding of a prepreg sheet material, or in the case of a hybrid structure in which different materials and materials are combined,
This includes the case where the fibers are not oriented in the axial direction of the core metal but are shifted depending on the manufacturing conditions to form an inclined structure. Form an auxiliary part
The prepreg sheet may be a single member or a composite material.

Further, in the above-mentioned second aspect , the auxiliary portion may be formed by a product of a longitudinal elastic modulus of the auxiliary portion in the axial direction of the tubular body and a linear expansion coefficient in the axial direction of the tubular member. Body of the body
A tubular body comprising a member larger than a minute . Further, in claim 3 , the auxiliary portion corresponding to claim 1 or 2 has a member in which the longitudinal elastic modulus of the auxiliary portion in the axial length direction of the tubular body is smaller than that of the main body portion of the tubular body. A tubular body characterized by the following.

According to a fourth aspect of the present invention, there is provided the method for producing a tubular body according to the first aspect, wherein the production conditions such as the flow of the resin during heating and the amount of change in the orientation direction of the reinforcing fibers with respect to the direction of the cored bar are determined. depending on the amount of change determined according, in the prepreg sheet is wound body material prior to thermoforming, the complement
The additionally provided position of the other prepreg sheet comprising a co moiety, and set the corrected position from the predetermined position, provides a method for producing a tubular body pressurized and heated.

According to a fifth aspect of the present invention, there is provided a tubular body reinforced by reinforcing fibers using a synthetic resin as a matrix, wherein the tubular body is formed by winding a sheet-shaped prepreg, and is formed in a direction including the circumference of the tubular body. during cross-section is a cross section is a symmetrical structure, the cross section of symmetrical structure are contiguous over a predetermined length range of the tubular body, the number of layers in said symmetrical structure cross-section is one turn in the circumferential direction It is obtained from the product of the longitudinal elastic modulus in the axial direction of the tubular body and the coefficient of linear expansion in the axial direction in the symmetrical structure cross section, and the tubular body is moved along the axial direction based on the temperature change. A tubular body characterized in that the bending moment is balanced .

According to the first aspect, since the cross section of the main body is assumed to have an asymmetric structure, the tubular body can be easily manufactured by a conventional method such as a method of winding a sheet material. Also obtained from the product of the longitudinal elastic modulus in the axial direction and axial length direction of the linear expansion coefficient of the tubular body in the cross section was balanced moment to bend along the axial direction of the tubular body on the basis of a temperature change Therefore, bending of the molded product can be prevented. As described above, the longitudinal modulus is also a factor of the bending moment,
In particular, when a high-strength and high-elastic fiber such as carbon fiber is used as a reinforcing fiber, the molded article is likely to bend. Therefore, the present invention is particularly applied to a tubular body using such a high-strength and high-elastic fiber. The effect is high. Further, even in a tubular body having a structure in which the aligned sheet is disposed at 50% or more in the axial direction of the tubular body, the aligned sheet fiber has a rate of acting on bending of the tubular body with respect to a temperature change. Therefore, the present invention is highly effective.

According to a second aspect, the auxiliary part is the tubular part
Longitudinal elastic modulus of the auxiliary part in the axial direction of the body and the axial direction
Is larger than the body portion of the tubular body.
The auxiliary part is compared with the main body part
The contribution rate to the bending moment according to the temperature change increases.
Auxiliary part as a material corresponding to the auxiliary part
Materials (below used without distinguishing between auxiliary members and auxiliary parts)
May be reduced).

According to a third aspect of the present invention, since the longitudinal elastic modulus of the auxiliary portion in the axial direction of the tubular body is smaller than that of the main body of the tubular body, it is caused by the presence of the auxiliary portion when using the ordinary tubular body. The influence on the bending rigidity of the tubular body is small, and it is possible to reduce the possibility that the tubular body has directivity in bending. When the tubular body is a rod tube, it is particularly important that the directionality of the bending is small. Here, the auxiliary part, if the product of the longitudinal elastic modulus and linear expansion coefficient of the polymerization of claim 2 having a larger member than the body portion, longitudinal elasticity than the auxiliary section main body portion <br/> A member having a small coefficient of expansion and a large coefficient of linear expansion is provided.

According to the fourth aspect, the winding body material sheet before the heat molding is prepared in consideration of the flow of the resin during heating and the amount of change in the orientation direction of the reinforcing fibers with respect to the direction of the cored bar. In order to heat-mold the tubular body by setting the attached position of the other prepreg sheet serving as the auxiliary portion to a position corrected and adjusted from a predetermined position in the molded tubular body, in the cross section of the actually molded tubular body, The auxiliary part can be located at a predetermined position. Therefore, bending of the formed tubular body can be accurately prevented.

According to claim 5 , the number of layers increases or decreases in the circumferential direction, that is, although there are less than one round of layers, the cross section at this position has a symmetrical cross-sectional structure.
Since the symmetrical structure cross-sectional state is made continuous in the predetermined length axis direction, the bending moment based on the temperature change can be balanced in this length region.

In the case where the bending caused in the baked conventional product is corrected later by a bending operation in which the bending is performed in the opposite direction, the bending occurs again if the bending is maintained in a high temperature environment for a long time. Since the bent tubular body is adapted to be prevented from bending in response to a temperature change, the bending is also prevented in such a case (the amount of bending is small).

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings. FIG. 1 is a perspective view of a tubular body taking a rod tube 10 as an example, and shows coordinate axes x, y,
z is defined as shown. That is, the axis of the rod 10 is set to the x-axis. FIG. 2 is an enlarged cross-sectional view of the rod tube 10 at the x position. DA indicates a minute portion in a radial direction ranging from r to r + dr and a circumferential direction ranging from an angle θ to θ + dθ. Is also shown. Assuming that the longitudinal elastic modulus in the axial direction of the minute portion dA is E, the minute portion dA
The bending stiffness dEI (x) with respect to the y-axis is expressed by the following equation.

DEI (x) = E · dA · (r · sin θ) ^{2 Further} , dA is represented by the following equation. dA = r · dθ · dr ∴dEI (x) = E · r ³ · sin ² θ · dθ · dr The bending stiffness at the x position of the rod 10 is such that the neutral plane of the bending passes through the center of the rod 10. In this case (that is, when the y-axis is a neutral axis), a value obtained by integrating this dEI (x) over the entire cross section having a constant x coordinate is obtained.

The portion where the material is wound on the last half of the proper number of layers is called the uneven thickness portion HN. Here, for convenience, the uneven thickness portion and the above-described auxiliary member are completely circled once again. When described by a formula that distinguishes from the layered portion and separates the integral for each layer, the bending rigidity EI (x) of the rod tube 10 is given by the following formula (1). Use [as the integral sign.

[0019]

Here, Σ in the second term is schematically shown in order to avoid complexity, and as described above, the uneven thickness portion that does not completely rotate, or the one that is continuous with the main body member and has a complete layer This means that the sum is calculated for the auxiliary members that do not form a part.
The symbols are as follows. n is the number of layers that make a complete circuit, and k = 1, 2,.
···, n E _k (θ): longitudinal elastic modulus in the axial direction at the angle θ of the k-th layer E (θ): longitudinal elastic modulus in the axial direction at the angle θ of the uneven thickness portion and the auxiliary member However, the auxiliary member may be included in the above E _k (θ). θ0: Start point angle of uneven thickness part and auxiliary member θC: End point angle of uneven thickness part and auxiliary member The meaning of other symbols is shown in FIG. 3, where the inner diameter of the k-th layer is r (k-1) and the outer diameter is Is rk.

Further, a fiber reinforced resin prepreg using a thermosetting resin is wound around a core metal to form a rod tube material, and when this is heated to a molding temperature and cured, there is no thermal stress and the rod tube is bent. If a certain temperature difference ΔT is applied, as in the case of cooling to room temperature, a bending moment is generated in the asymmetrical structure based on the thermal stress in the axial direction generated in each part, and a bending moment is generated along the longitudinal direction. Bending occurs. Y above
If the axis is a bending neutral axis and the linear expansion coefficient in the axial direction of the minute portion dA is α, the bending moment dM (x) due to the temperature difference ΔT acting on the minute portion dA is expressed by the following equation.

DM (x) = (E · α · ΔT · dA) · (r · sin θ) The bending moment M (x) at the x position of the rod tube 10 is obtained by dividing this dM (x) by the entire x-coordinate constant cross section. Is the value integrated over the range. Similarly to the case of the bending rigidity, if the uneven thickness portion and the auxiliary member are separately expressed, the bending moment M (x) at the x position of the rod pipe 10 is expressed by the following equation (2).

[0023]

Here, in the second term, Σ is simply shown in order to avoid complexity as in the case described above. means. The symbols are as follows. α _k (θ): Linear expansion coefficient in the axial direction at the angle θ of the k-th layer α (θ): Linear expansion coefficient in the axial direction at the angle θ of the uneven thickness portion and the auxiliary member In the case of a member, it may be included in the above α _k (θ).

Here, assuming that the radius of curvature at the x position of the rod tube is ρ (x), the curvature κ (x) can be obtained by the following equation (3). κ (x) = 1 / ρ (x) = − M (x) / EI (x) (3)

The bending of the rod tube 10 is prevented, that is, the curvature κ
In order to make (x) substantially zero, the bending moment M (x) may be made substantially zero, as can be seen from Equation (3). That is, the moment ΔM (x), which is obtained from the product of the longitudinal elastic modulus and the linear expansion coefficient and bends the rod tube 10 along the axial direction based on the temperature change in each portion, is balanced as the entire cross section at the x position. Then, bending of the rod tube 10 at the x position is prevented. Therefore, if this balance is maintained at each x position, bending is prevented over the entire length of the rod tube 10.

As a specific method of balancing the bending moment, the combination of the longitudinal elastic modulus and the linear expansion coefficient in the axial direction at each portion of the x cross section is calculated by using the bending moment M (x) of the above equation (2) to be approximately 0. What is necessary is just to select the reinforcing fiber or matrix synthetic resin used in the position of the cross section. In addition, if the material of the rod tube body and the orientation of the reinforcing fiber are determined by some factors and cannot be adjusted, an auxiliary member is added so that the bending moment M (x) becomes substantially zero. I do. This auxiliary member can have an angle in the width direction (circumferential direction) of , for example, about 90 degrees, and is provided along the axial direction of the wound (or before wound) rod body material. Heat molding is performed integrally with the main body material.

As this auxiliary member, a material having a good affinity for the synthetic resin of the material of the rod pipe main body is preferable, and a composite material such as a synthetic resin sheet or a prepreg obtained by impregnating a resin into a reinforcing fiber may be used. In particular, in the case of the same composite material, the characteristics of the longitudinal elastic modulus and the coefficient of linear expansion in the axial direction differ depending on whether the direction of the reinforcing fiber is directed in the axial direction of the rod tube or in the circumferential direction, even if the same composite material is used. If the composite fiber is integrated into the rod body so that the direction of the reinforcing fibers is oriented in the circumferential direction of the rod, the longitudinal elastic modulus in the axial direction will be small, and the effect on the bending rigidity of the rod will be small. The directionality of the bending is small, which is preferable. In addition, a sheet obtained by impregnating a nonwoven fabric or paper as a base material with a synthetic resin, or a thermoplastic resin sheet can also be used. In the former case, the synthetic resin is less likely to flow due to the presence of the base material, and has the effect of being held at a fixed position.In the latter case, the melting temperature is high. It can be integrated into the main body while maintaining the desired shape.

The integral circumferential angular position of the auxiliary member is as follows in principle. Regardless of whether the rod tube body material has a positive linear expansion coefficient in the axial length direction (expanded when the temperature rises) or a negative one (shrinks when the temperature rises), the auxiliary member with a positive linear expansion coefficient has the maximum curvature of the rod tube. 180 in the circumferential direction from the circumferential position
Integrate around the position shifted by degrees. Alternatively, an auxiliary member having a negative coefficient of linear expansion is integrated around a circumferential position where the curvature of the rod tube is maximized.

The bending of the rod tube body differs from the design value due to the amount of change determined according to manufacturing conditions such as the flow of resin and the amount of change in the orientation direction of the reinforcing fibers when the rod tube body material is heated and formed by the prepreg. However, the amount of change such as the resin flow and the orientation direction of the reinforcing fiber due to the manufacturing conditions is estimated in advance, and the position where the auxiliary member is added to the rod pipe body material is integrated into the rod pipe after the molding is completed. Different from the position in the wound rod material corresponding to the position where the rod pipe 10 is located, by setting the position corrected according to the estimated amount, the bending of the rod 10 can be prevented with higher accuracy.

In order to make the bending moment M (x) of the above equation (2) substantially zero, a member having an arbitrary size (an auxiliary member) may be used in addition to using an auxiliary member having a small circumferential angle. It does not matter whether it is referred to as a main body member or a main body member), and the cross section after molding may be formed into a symmetrical structure. An example of manufacturing the tubular body will be described with reference to FIG. Taking a rod pipe as an example of the tubular body, a trapezoidal prepreg sheet P1 serving as a main body is wound around a core metal 20 exactly three times. On top of this, the bending rigidity of the rear part of the rod tube (corresponding to the rear part 20B of the core metal) is high,
In order to make the front portion (corresponding to the front end portion 20A of the core metal) flexible, fibers having a higher elastic modulus of the reinforcing fibers than the prepreg sheet P1 are directed in the longitudinal direction. A triangular prepreg sheet P2 having a bottom size large enough to be wound five times is wound.

However, if the rod tube is formed as described above, the cross section thereof is shown in FIG. 5 over a predetermined length range from the front end position of the rod tube around which the prepreg sheet P2 is wound to the rear. On such three layers L1, L2, L3 (layers made of the prepreg sheet P1), a circumferential angle θ1 ( this section
A fourth layer L4 (a layer made of the prepreg sheet P2) having a plane position of 180 degrees or less exists, and the structure has an asymmetric cross-sectional structure, and a bending moment is generated based on a temperature change. In order to prevent this, as shown in FIG. 4, the prepreg sheet P3 which is the same as the prepreg sheet P2 is placed at a position corresponding to each part of the prepreg sheet P2 with respect to the center of the cored bar 20 (the center C of the rod tube 30). Winding is performed by setting the position so that it is located on the opposite side by 180 degrees. FIG. 5 shows the rod tube 30 formed in this manner. A layer L4 ′ of the same material and the same size exists on the opposite side of the fourth layer L4 by 180 degrees with respect to the center C of the rod tube. Accordingly, a bending moment based on a temperature change of the rod tube 30 can be prevented.

The rear portion of the rod pipe 30 whose circumferential angle θ1 exceeds 180 degrees is a prepreg sheet P3 wound later.
Overlaps with the previously wound prepreg sheet P2, the balance of the bending moment cannot be maintained by the difference in radius, but the difference in radius is generally negligible, and is generally over the entire length of the rod tube 30. The balance of the bending moment can be maintained. However, in the present invention, it is not always necessary to maintain the balance of the bending moment over the entire length of the rod pipe, and the balance of the bending moment can be maintained at the cross section at each position over a part of the length range. This has the effect of suppressing the occurrence of bending moment.

Unlike the above, both prepreg sheets P1 and P2 are made of the same material, prepreg sheet P2 is formed in advance (in one piece) with prepreg sheet P1, and prepreg sheet P3 is also made of the same material. The same tubular body 30 as above is formed, and the bending moment is likewise prevented. That is, the leading end of the prepreg sheet in which the prepreg sheets P1 and P2 are united is wound three times around the cored bar 20 and the trailing end is wound 4.5 times.
From above, the prepreg sheet P3 is wound by adjusting the winding start position so that the cross section of the rod tube 30 becomes as shown in FIG. Also, the number of turns of the end portion of 3 times and 4.5 times is merely an example, and may be 3 times and 4 times, or 3.2 times and 4.2 times.

However, in the case of the latter two examples, the prepreg sheet P3 having the size described above is not used,
If the number of turns is 4 and the back end is 4, the bottom is a triangle large enough to be wound once, and the last example is 3.2 turns at the front end and 4.2 turns at the rear end. , Prepreg sheet P3 is 3
Instead of a square shape, a trapezoid with a lower end having a top end corresponding to a thickness variation portion for 0.2 turns and a rear end capable of winding 1.2 times is used.

The bending moment M of the above equation (2)
In order to make (x) substantially zero, the cross section of the formed rod pipe 32 is formed into a symmetrical structure using an additional member of an arbitrary size. The meaning is not limited to the case where the member to be added is arranged only on the opposite side of 180 degrees as shown in FIG. 5, but is arranged at equal angles θ such as 120 degrees as shown in FIG. Each additional member L5, L
6, and the case where the bending moment by L7 can be canceled each other.

FIGS. 4 to 6 show the case where the uneven thickness or the added outermost members (L4 to L7) are made of the same material and have the same size, but as shown in FIG. The members L8 and L8 'of FIG.
Even if the members L9 and L9 'of the other size and having the same size are arranged opposite to the center C in the same manner, they are symmetrical, and the bending moments cancel each other. In this case, all the members L8, L8 ', L9, L
Although 9 'is made of the same material, members L8 and L8' are symmetrical even if they are made of the same material, and members L9 and L9 'are made of other same material.

[0038]

As is apparent from the above description, according to the present invention, in the tubular body, the bending moment caused by the temperature change due to the uneven thickness of the wall and the inclination of the fiber is balanced, and the product is manufactured. Prevent bending and manufacturing
Can be easier.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tubular body according to the present invention.

FIG. 2 is a cross-sectional view of the tubular body of FIG. 1 at an x position.

FIG. 3 is a cross-sectional view of a tubular body for explaining symbols in a formula for explaining the present invention.

FIG. 4 is a diagram showing an example of a method for producing a tubular body according to the present invention.

FIG. 5 is a cross-sectional view of a tubular body manufactured by the method shown in FIG.

FIG. 6 is a cross-sectional view of a modification of the tubular body of FIG.

FIG. 7 is a cross-sectional view of another modified example of the tubular body of FIG. 5;

[Explanation of symbols]

 10 Rod pipe (tubular body) E Longitudinal elastic modulus in the axial direction of the tubular body HN Uneven thickness part n Number of complete winding layers x Coordinate in the axial direction of the tubular body α Linear expansion coefficient in the axial direction of the tubular body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI B29D 23/00 B62K 19/16 B32B 5/00 B29K 105: 08 // B62K 19/16 B29L 23:00 B29K 105: 08 B29C 67 / 14 RB29L 23:00 A01K 87/00 630A 630C (58) Fields studied (Int. Cl. ⁷ , DB name) B29C 70/00-70/88 A01K 87/00-87/08 A63B 49/00- 49/18 A63B 53/00-53/16 A63C 11/00-11/26 B29D 23/00-23/24 B32B 5/00-5/32 B62K 19/00-19/48

Claims (5)

(57) [Claims] A reinforced fiber comprising a synthetic resin as a matrix.
A tubular body reinforced bySheet-shaped prep
The leg is wound to form the main body,  The cross section, which is a cross section including the circumference of the tubular body, is asymmetric.
A longitudinal elasticity of the tubular body in the axial length direction in the cross section of the asymmetric structure.
From the product of the coefficient of thermal expansion and the coefficient of linear expansion in the axial direction.
Moment of bending the tubular body along the axial direction based on
At other positions in the cross section,
An auxiliary part was formed by providing a sheet-shaped prepreg ofthing
A tubular body characterized by the above. 2. The auxiliary part includes a member in which a product of a longitudinal elastic modulus of the auxiliary part in an axial direction of the tubular body and a linear expansion coefficient in the axial direction is larger than a main body part of the tubular body. The tubular body according to claim 1, wherein: Wherein said auxiliary portion, claims, characterized in that the longitudinal elastic modulus of the auxiliary section in the axial direction of the tubular body comprises a smaller member than the body portion <br/> of the tubular body 1
Or the tubular body according to 2 . Claim 41Method for producing a tubular body of
To strengthen the resin flow and the direction of the core during heating.
Changes determined according to manufacturing conditions, such as changes in fiber orientation direction
Wound body material before heat formingIs a pre-pre
GucietIn,SaidOther prepregs as auxiliary parts
SheetThe attachment position of,From the predetermined position to the corrected position
ConfigurationAnd  A method for producing a tubular body by heating under pressure. 5. A reinforced fiber comprising a synthetic resin as a matrix.
A tubular body reinforced bySheet-shaped prep
The leg is wound and molded,  A cross section that is a cross section in a direction including the circumference of the tubular body isSymmetryWhat
StructureSymmetryThe cross section of the structure is within the specified length of the tubular body
And is continuous overSymmetryWhile the number of layers in the structural cross section makes one round in the circumferential direction
Has increased or decreasedSymmetryLongitudinal elastic modulus of tubular body in axial direction in structural cross section
And the coefficient of linear expansion in the axial direction.
Moment of bending the tubular body along the axial direction based onBa
LanceA tubular body characterized in that the tubular body is made to have a shape.