JPH06200951A - Joint method for driving force transmission shaft made of frp with pipe made of frp - Google Patents

Abstract

PURPOSE:To strengthen joint, prevent invasion of moisture, and improve durabil ity and torque transmission capacity, by pressingly fitting a combining element into a pipe made of FRP so as to join them together by spline engagement, and filling adhesive in the clearance of the engaged part. CONSTITUTION:Serration is worked on the joining face 6 of a combining element 2. Meanwhile, serration in not worked on the joining face 5 of a pipe 1 made of FRP. The inner diameter of the joining part 3 of the pipe 1 made of FRP is set smaller than the outer diameter of the joining part 4 of the combining element 2. By pressingly fitting the joining part 4 of the combining element 2 in the joining part 3 of the pipe 1 made of FRP pressure is applied between these respective joining faces 5, 6, and the teeth 7 of the serration on the joining face 6 of the combining element 2 are made to bite the joining face 5 of the pipe 1. At this time, adhesive is filled in the clearance between the respective joining faces 5, 6. Hereby, joint is strengthened, prevention of invasion of moisture, and improvement of durability and torque transmission capacity are attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fiber reinforced resin (hereinafter referred to as F
(Hereinafter sometimes referred to as RP) drive force transmission shaft, and particularly to a high torque drive force transmission shaft suitable for automobiles, ships and helicopters. The present invention also relates to a method for joining the FRP pipe and the joining component.

[0002]

2. Description of the Related Art Generally, a shaft for transmitting a driving force of a vehicle, a ship, etc. is formed by joining a metal coupling element (also referred to as a coupling element) to both ends of a metal solid rod or a metal hollow pipe. . In recent years, attention has been paid to the weight reduction of automobiles, and not only is the metal of the vehicle body made of FRP, but also the weight reduction of structural members has been attracting attention. Among them, the weight reduction of the shaft for transmitting the driving force has a great effect on the weight reduction because it is a rotating portion, and the FRP type has been particularly noted. Since the weight is reduced to 1/4 to 1/2 by changing from conventional steel to FRP, it has come to be mounted on various automobiles.

In the pursuit of comfortable riding comfort in ships as well, attention has been paid to the use of FRP for the drive force transmission shaft in order to remove the resonance frequency from the practical range. FRP is superior in specific strength (strength / density) and specific rigidity (elastic modulus / density) to metals such as steel and aluminum, and by changing the orientation angle of the fiber, bending rigidity and torsional rigidity can be improved. Since it can be freely changed, it is possible to increase the resonance frequency and, conversely, decrease it while maintaining the strength of the twist.

In the case of an FRP driving force transmitting shaft, generally, a joining element must be provided at both ends of a hollow FRP pipe, and the joining portion of the joining element is molded and joined by the filament winding method. Alternatively, it is manufactured by separately preparing the FRP pipe and the coupling element and then joining them by some method. For example, bonding with an adhesive is known, but there are problems that the adhesive force is insufficient to transmit a high torsion torque, or the adhesive force decreases with time. Further, a method of forming a regular polygonal shape of the joint is also known, but there is a problem in that it takes time and labor for processing and productivity is low.

Various other methods have been proposed to transmit a high torsion torque. Actual exploitation 53-9378
JP-A-54-97541, JP-A-55-
No. 159311, JP-A-54-132039, and JP-B-62-53373 disclose a coupling element and FR.
Methods have been proposed in which the joints of the P pipes are joined by serration processing, or the joints of the serrated joint elements are cut into the inner wall of the FRP pipe to join them. .

[0006]

However, with the former method, it is difficult to form serration teeth on the inner wall of the FRP pipe during molding. When the serration is formed by machining, the reinforcing fiber is cut, so that the strength of the joint is reduced and it is impossible to transmit a high torsion torque. Also, in the latter case, there is a problem in that the reinforcing fiber of the joint portion is easily cut by the serration teeth of the joint portion of the coupling element and thus high torsion torque cannot be transmitted. In order to secure the joining, a method has been proposed in which a metal outer ring is put on the outside of the joining portion to reinforce the joining portion, but there is a problem that the effect of weight reduction is diminished.

[0007]

The present invention comprises the following inventions. (1) A joint portion of a fiber reinforced resin pipe and a joint portion of a coupling element having an outer surface or an inner surface serrated.
In the shaft for driving force transmission made of fiber reinforced resin, which is joined, the joint portion of the fiber reinforced resin pipe and the joint portion of the coupling element are joint portions of the fiber reinforced resin pipe formed by press fitting. A driving force transmission shaft made of fiber reinforced resin, characterized in that the coupling element is joined by serration biting into the coupling element, and the gap between the biting parts is filled with an adhesive. (2) The elastic modulus in the circumferential direction is 30 G on the joint surface of the joint portion of the fiber-reinforced resin pipe into which the serration of the coupling element is bitten.
The fiber-reinforced resin driving force transmission shaft according to (1), in which a protective layer having a pressure of Pa or less is laminated, and the serrations are bitten through the protective layer. (3) A reinforcing layer is provided on the middle portion, outer surface, or inner surface of the joint portion of the fiber-reinforced resin pipe, and the thickness (t
The fiber-reinforced resin drive force transmission shaft according to (1) or (2), wherein the ratio (tj / tp) of j) to the thickness (tp) of the pipe is 3 or less. (4) When joining the joint portion provided at the end portion of the fiber reinforced resin pipe and the joint portion provided at the end portion of the joint component, serration is applied to the inner surface or the outer surface of the joint portion of the fiber reinforced resin pipe. Without performing the processing of (1), the outer surface or the inner surface of the joint portion of the joint component is subjected to serration processing, and an adhesive is applied to at least one joint portion of the fiber-reinforced resin pipe and joint component, A fiber-reinforced resin pipe and a connecting part are characterized in that the joint part of the fiber-reinforced resin pipe is press-fitted to the joint part or the joint part of the joint part is press-fitted with the fiber-reinforced resin pipe. Joining method. (5) The method for joining a fiber-reinforced resin pipe and a connecting component according to the above (4), wherein a protective layer having a circumferential elastic modulus of 30 GPa or less is laminated on the joint surface of the joint portion of the fiber-reinforced resin pipe. (6) The method for joining a fiber-reinforced resin pipe and a joining component according to the above (4) or (5), wherein the joining component is a joining element of a driving force transmitting shaft.

A typical example of the fiber-reinforced resin driving force transmitting shaft according to the present invention is shown in FIGS. 1 and 2 (A-A sectional view of the fiber-reinforced resin driving force transmitting shaft in FIG. 1). The FRP pipe (1) is obtained by molding and curing by a known method such as a filament winding method or a rolling table method. The joining surface (6) of the coupling element (2) is previously subjected to serration processing as shown in FIG. The joint surface (5) of the FRP pipe is not subjected to serration processing, and the inner diameter of the joint portion (3) of the FRP pipe is the outermost diameter of the joint portion (4) of the coupling element (measured from the tip of the serration teeth). The joint surface (5) of the FRP pipe and the joint (4) by press-fitting the joint portion (4) of the coupling element into the joint portion (3) of the FRP pipe by applying a load. Pressure is applied between the joining surfaces (6) of the elements so that the serration teeth (7) on the joining surfaces (6) of the joining elements bite into the joining surfaces (5) of the FRP pipe to join them. At this time, an adhesive (8) is filled between the joint surface (5) of the FRP pipe and the joint surface (6) of the coupling element to fill the gap between both joint surfaces. The state of biting of the serration thus obtained is as shown in the enlarged view of FIG. The use of an adhesive strengthens the joint and prevents water from entering the gaps in the joint, which improves torsional transmission performance, corrosion resistance, environment resistance, and durability. Is improved. Here, the method of filling the adhesive is not particularly limited. Before press-fitting and fitting, an adhesive is applied to the joint surface (5) of the FRP pipe and / or the serrations (6) of the joint surface of the coupling element to join them. This is a particularly preferable method because it functions and reduces the press-fitting load (pressurizing input) and prevents the joint surface (5) of the FRP pipe from being damaged by the serration teeth (7) during press-fitting. Alternatively, it is also possible to fill the gap between the meshing parts with an adhesive after press-fitting and fitting.

Further, as shown in FIG. 3, a protective layer (9) is provided on the joint surface (5) of the FRP pipe, and the serration teeth (7) join the FRP pipe through the protective layer (9). It is preferable to be caught in the surface (5). By providing such a protective layer, it is possible to further strengthen the joint and at the same time prevent the serration teeth from directly hitting and damaging the portion of the FRP pipe that bears the substantial load.

The reinforcing fiber material used in the present invention is preferably a fiber having a high elastic modulus and strength because it is necessary to increase the resonance frequency of the driving force transmitting shaft during rotation. Further, it is preferable to use a fiber having a large specific strength and a large specific rigidity because the effect of weight reduction is remarkable. Examples of such fibers include carbon fibers, glass fibers, aramid fibers, ceramic fibers and the like. It is also possible to use two or more of these fibers in combination. Among them, carbon fiber is preferably used, and hybrid use of carbon fiber and glass fiber is also preferable from the viewpoint of strength and economy.

The form of the fiber is not particularly limited and may be roving, woven, prepreg or the like. The orientation angle of the fibers is preferably ± 30 ° to ± 90 ° for transmitting high torsional torque, and is preferably in the range of 0 ° to ± 30 ° for aiming for high resonance frequency.
Depending on the required properties, the orientation angle of the fibers can be selected within an optimum range by calculation.

The matrix resin of the fiber reinforced resin is not particularly limited, and includes epoxy resin, unsaturated polyester resin, vinyl ester resin, urethane resin, phenol resin, alkyd resin, imide resin, bismaleimide resin, xylene resin, melamine. Resin, furan resin, thermosetting resin such as silicone resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polymethylmethacrylate resin, ABS resin, fluorine resin, polycarbonate resin, polyester resin, polyamide resin (nylon 6, 6. 6, 6.10, 6.11, 6.12), a thermoplastic resin such as a polyphenylene sulfide resin, a polysulfone resin, a polyether sulfone resin, a polyether ether ketone resin, and a polyphenylene oxide resin. be able to. Of these, epoxy resin, unsaturated polyester resin and vinyl ester resin are preferable from the viewpoint of performance and handleability. Further, two or more kinds of resins and fibers can be combined as required.

The fiber volume content of FRP pipe is 40%
Or more and 75% or less, preferably 50% or more and 70% or less. If the content is less than 40%, the strengthening effect is low, and a thick pipe must be used, so that the effect of reducing the weight is small. If it exceeds 75%, the probability of contact between fibers becomes high and the torsional strength becomes low.

The method of molding the FRP pipe is not particularly limited and can be manufactured by a known method, but the filament winding method and rolling table method are preferable in terms of molding efficiency and performance.

The material of the connecting element used in the present invention is preferably metal because of its excellent mechanical properties and easy processing. From the viewpoint of strength and rigidity, iron, aluminum, titanium, magnesium, and alloys containing these metals as main components are particularly preferable.

In the present invention, the serration applied to the joint portion of the joint component or joint element by machining is a mountain-shaped streak extending in the axial direction or substantially the axial direction, and is provided on the entire circumferential surface adjacent to each other. The radial cross-sectional shape is a serrated shape (hereinafter, the serrated mountain-like streaks may be simply referred to as serration teeth). Depending on the processing method and shape, what is called a knurl or spline is also included. In the present invention, the shape of the serration teeth (the shape of the radial cross section) is not necessarily limited, but a preferable shape is exemplified by a convex shape such as a triangle, a square or a trapezoid as shown in FIG. A strong binding force can be obtained by using these serrations.

Height of serration teeth (h in FIG. 5)
Is not necessarily limited by the magnitude of the required transmission torque, the dimensions of the coupling element or the FRP pipe, the presence or absence of the protective layer, and the material and thickness of the protective layer.
It can be selected in the range of 5 to 10 mm, preferably 0.05 to 3.0 mm. FR is less than 0.005mm
Less bite of serration in P pipe,
The torsion torque held by one crest of serration becomes too large, and the inner layer of the FRP pipe is easily broken. The pitch of the serration teeth (indicated by p in FIG. 5) is determined by the magnitude of the required transmission torque, the coupling element and the F
Although it is not necessarily limited depending on the size of the RP pipe, the presence or absence of a protective layer, and the material and thickness of the protective layer, 0.05 to 1
It can be selected in the range of 0 mm, preferably 0.1 to 5.0 mm.

The serration teeth are preferably parallel to the axis of the coupling element, but 15 to the axis of the coupling element.
It may have an angle in the range of ° or less.

When joining the joining element to the inside of the FRP pipe, the outer diameter (df) of the joining portion of the joining element up to the tips of the serration teeth is the inner diameter of the FRP pipe (dp, if there is a protective layer, it is protected). (Inner diameter including layers) The optimum value of the df / dp ratio is not necessarily limited because it depends on the required torque transmission force, the inner diameter and thickness of the FRP pipe, the material and thickness of the protective layer used, and the shape and size of the serration. It can be appropriately selected within a range in which the protective layer is cut at the time of fitting and a high torque transmission force is achieved without damaging the FRP pipe. The df / dp ratio is preferably 1.0002-
It can be selected in the range of 1.020, more preferably 1.001 to 1.010, but is not limited to this range.

For example, the inner diameter of the FRP pipe is 70 mm
When the ratio is about 1.028, a large press force is required for press fitting and fitting, and a large strain is generated in the joint portion of the FRP pipe, so that the joint surface is broken with low torque. . On the contrary, this ratio is 1.0002.
When it is smaller, the press-fitting becomes relatively easy, but the serration is not sufficiently caught in the FRP shaft portion, the holding force against the torsion torque is hard to be generated, and the torque transmitting ability is low.

The outer shape of the tip of the joint portion of the coupling element is FR so that it can be smoothly inserted into the joint portion of the FRP pipe.
It is preferable that it has a taper shape that is smaller than the corresponding inner surface shape of the joint portion of the P pipe and that spreads smoothly from the tip portion of the coupling element toward the root. For example, the taper angle of the tip of the coupling element is preferably 30 ° or less. On the contrary, it may have a taper shape that narrows smoothly from the tip of the FRP pipe joint to the back. The length of the joint varies depending on the required breaking torque, but can be shortened by using an adhesive or preferably a protective layer. The length of the joint is not necessarily limited by the size of the coupling element and the required breaking torque, but preferably the ratio of the length of the joint to the inner diameter of the FRP pipe is 0.
It is selected to be 1 to 1.5. For example, the inner diameter is 70
In the case of mm FRP pipe, the joint length is 10
It is preferably about 100 mm.

The adhesive used in the present invention is preferably liquid and has a viscosity of 50 to 10,000 poise at room temperature. An adhesive is applied to at least one of the joining surfaces of the serrations of the joining element and the joining surface of the FRP pipe, and press-fitted to join them. After joining, the adhesive is subjected to a curing treatment, for example, a heat treatment, if necessary. As a result, the joining is achieved more firmly and the transmission torque is improved. In addition, the void portion generated in the biting portion of the joint portion is filled, the invasion of moisture can be prevented, and the environmental resistance performance and the durability performance can be improved. Further, the use of this adhesive exerts an effect as a lubricant when the coupling element is press-fitted to the FRP pipe, and reduces the press-fitting load, and at the same time, reduces the strength and causes the press-fitting of the FRP surface and its It is possible to prevent damage to the protective layer. When the viscosity of the adhesive is lower than 50 poise, the adhesive flows at the time of joining, and when it is higher than 10,000 poise, it is difficult to press-fit the coupling element due to viscous resistance. The adhesive is not particularly limited,
Various adhesives such as epoxy type, urethane type, cyanoacrylate type, modified acrylate type, various rubber type, polyester type and polyimide type adhesives are used. Among them, epoxy type is preferable in terms of adhesion performance, environment resistance, handleability and the like. Suitable adhesives include, for example, Epoxy Patch Kit (manufactured by Hysole Co., Ltd.), Technodyne HT18-X.
(Taoka Chemical Co., Ltd.), Sony Bond (manufactured by Sony Chemical Co., Ltd.), and the like, but not limited to these.

The protective layer used in the preferred embodiment of the present invention means that the elastic modulus in the circumferential direction existing on the joint surface of the joint portion of the FRP pipe, that is, the surface of the biting portion is 4G.
It is a thin layer of Pa or more and 30 GPa or less and is provided so that the serration teeth do not directly hit the FRP pipe and the fibers of the FRP pipe are not damaged. When it is lower than 4 GPa, the serration teeth are easily elastically deformed by the rotational force after the serration teeth are press-fitted, and the serration teeth are displaced even under a low rotational force. Three
If the pressure is higher than 0 GPa, the serration teeth are not sufficiently caught during the press-fitting or the protective layer is damaged, resulting in difficulty in maintaining the rotational force. A fiber reinforced resin is exemplified as the material of the protective layer, and it can be used in the form of the fiber reinforced resin layer. When the FRP pipe is manufactured by the filament winding method or the tape winding method, this protective layer may be wound around a mandrel in advance or may be pasted on the inner surface after molding the FRP pipe. It is particularly preferable that it is integrated with. The protective layer may be provided on the surface of the FRP pipe only in the vicinity of the joint, or may be provided on the entire pipe for the convenience of the manufacturing process.

The fiber-reinforced resin layer as a protective layer is a layer obtained by impregnating a matrix resin with a non-woven fabric or woven fabric (woven fabric) of various reinforcing fibers and curing it. Examples of the reinforcing fiber include glass fiber, carbon fiber, inorganic fiber such as alumina fiber, and organic fiber such as aromatic polyamide fiber. Specifically, for example, a non-woven fabric such as glass fiber generally referred to as a surface mat is impregnated into a matrix resin to form a thin layer, and a thin fabric such as scrim generally referred to as glass fiber is impregnated into a matrix resin to be thin. For example, those formed in layers are used, but the present invention is not limited to these.

As the matrix resin material used for the protective layer, the matrix resin used for molding the FRP pipe can be exemplified. When a thermosetting resin is used as the matrix resin for the protective layer, FRP is used.
It can be simultaneously cured when the matrix resin of the pipe made is cured.

As the protective layer used in the present invention, the circumferential elastic modulus (Ef) and the circumferential elastic modulus (Em) of the coupling element are used.
It is preferable that the ratio (Ef / Em) is about 0.2 or less. By selecting this characteristic range, the serration teeth of the joint portion of the coupling element are easily engaged with the protective layer, and the torque transmission performance is further improved.

The thickness (tf) of the protective layer and the height of the serration teeth used in the present invention (indicated by h in FIG. 5).
Depends on the required breaking torque, coupling element and FRP
The ratio (tf / h) is preferably 0.5 or more and 5 or less, though it is appropriately selected depending on the dimensions of the pipe to be manufactured and the material and thickness of the protective layer. When the ratio (tf / h) is less than 0.5, the serration teeth are less likely to be bitten, the torque transmission performance deteriorates, and the FRP at the pipe connection part is destroyed when the coupling element is press-fitted. To do. Also, the ratio (t
If f / h) is larger than 5, it is difficult to form the protective layer on the mandrel during forming, which makes the forming difficult. In addition, since the serration teeth of the coupling element are not sufficiently caught in the FRP pipe, the torque transmission performance is deteriorated, and the serration teeth are caught when the coupling element is press-fitted. A very large load will be required.

The joint between the coupling element and the FRP pipe is strengthened, and the load torsion torque is surely secured from the coupling element to the FRP.
It is preferable to have a reinforcing layer at the joint of the FRP pipe for transmission to the pipe. The reinforcing layer refers to a layer that is provided only at the joint portion outside, inside, or in the middle of the laminated structure of the pipe (straight pipe) portion of the FRP pipe. By providing the reinforcing layer, it is possible to easily engage the serration teeth with the FRP pipe portion when the coupling element is press-fitted, and to secure the holding force against the torsion torque. The higher the circumferential elastic modulus of the reinforcing layer, the greater the effect. The reinforcing layer is not particularly limited, and examples thereof include a FRP reinforcing layer and a metal reinforcing tube.

Reinforcing this portion with the reinforcing fibers has a great advantage in terms of weight reduction as compared with the case where a metal reinforcing tube is attached. The FRP reinforcing layer can be integrally formed with the FRP pipe. The reinforcing fibers used for reinforcement are preferably the above-mentioned fibers, carbon fibers are preferred in terms of elastic modulus, and glass fibers are preferred in terms of cost. The winding angle of the reinforcing fiber is preferably ± 60 to 90 °. When wound at an angle smaller than ± 60 °, the expansion force of the FRP pipe cannot be suppressed when the coupling element is press-fitted, and the serration teeth are likely to be caught insufficiently, resulting in the transmission of torsional torque. It tends to be insufficient. Further, it is preferable to provide a taper portion between the joint portion and the pipe portion so that the wall thickness changes smoothly at an angle of 10 ° or less, and at the boundary portion between the pipe portion and the taper portion or the joint portion at the time of torque load. It has the effect of alleviating the stress concentration, but it is not always necessary. It is also possible to reinforce this part by using a metal reinforcing tube.

The thickness of the reinforcing layer is selected so that the ratio (tj / tp) of the thickness (tj) of the joint portion of the FRP shaft to the thickness of the pipe portion, that is, the thickness (tp) of the pipe wall is 3 or less. Is preferred. Ratio (tj / tp) is 3
In the above case, the reinforcing effect is saturated and the disadvantages such as an increase in diameter and an increase in weight increase.

In the method of manufacturing the FRP driving force transmitting shaft of the present invention described above, serrations are formed on the outer peripheral surface of the joint portion of the coupling element, and the joint is formed on the inner peripheral surface of the joint portion of the FRP pipe. Although a method of press-fitting while fitting the joint portion of the element with an adhesive has been described, as another embodiment as its application, serration is formed on the inner peripheral surface of the joint portion of the coupling element, It is possible to propose a second method in which the joint portion of the FRP pipe is press-fitted therein.
When the second method is carried out, the above-mentioned reinforcing layer can be used on the inner peripheral surface of the joint portion of the FRP pipe in order to prevent the deformation of the FRP pipe during press fitting.

The above-described method of manufacturing the FRP driving force transmitting shaft of the present invention can be widely applied to a method of joining an FRP pipe and various connecting parts in general.
It is useful for expanding the applications of FRP pipes. By performing the serration process as described above on the joint surface of the joint part to be joined to the FRP pipe, the fitting with the FRP pipe is performed, and the adhesive is used in the biting part, A strong joining force can be easily achieved with a smaller pressure input. Here, the coupling component is a component used by being joined to the FRP pipe, and is not particularly limited.

Examples of the connecting parts include parts forming the end of the FRP roll manufactured from the FRP pipe and joints used for connecting the FRP pipe such as a bearing and other parts. To be The material of the joint component is not particularly limited as long as it can form strong serrations. For example, various metals typified by steel, various ceramics typified by alumina, and various resins having high rigidity can be cited.

The shape and size of the serration are appropriately selected and determined according to the purpose and the size of the product. As an embodiment of the present invention, a driving force transmitting shaft obtained by joining a FRP pipe and a metal yoke will be described in detail below. The present invention can exhibit its characteristics in the production of the driving force transmission shaft in that it exhibits a high torque transmission force, but the method of the present invention and the product obtained thereby are not limited to these examples, It can be widely applied.

[0035]

【Example】

Examples 1 to 7 (1) Manufacturing example of FRP pipe A stainless steel mandrel having an outer diameter of 70.0 mm and a length of 1500 mm was attached to a filament winding device. If a protective layer is used, the mandrel center 100
Protective layers of various materials and thicknesses shown in Table 1 were wound around each of the lengths of 0 mm at a length of 50 mm. Next, the carbon fiber and the glass fiber were impregnated in a liquid epoxy resin and wound from above in the following manner. Carbon fiber manufactured by Sumika Hercules Co., Ltd., product name: Magnamite AS-4 (general-purpose carbon fiber: elastic modulus 24 ton / mm ² , strength 39)
0 kg / to mm ^2), glass fibers, Asahi Fiber Glass Co., Ltd., T-30 roving (product designation: R115
0F08) and bisphenol A as epoxy resin
Type epoxy resin (trade name: Sumiepoxy ELA-12
8. An aromatic amine curing agent (trade name: TONOX 60/40, manufactured by Uni Royal Co., Ltd.) was used for Sumitomo Chemical Co., Ltd.

First, the glass fiber impregnated with the epoxy resin is set to an angle (with respect to the axis of the pipe) of ± 85 to 90.
Wound with a thickness of 0.4 mm. However, in Examples 2 and 5 and Comparative Example 2 described later, this ± 8
No 5-90 ° wound layer was formed. Then, the carbon fiber impregnated with the epoxy resin is angled ± 1 from above.
It was wound at 6 ° and a thickness of 2.85 mm. At this time, the fiber volume content was adjusted to 60 ± 2%. The fibers shown in Table 1 at the joints on both ends, the thickness, and the angle ± 85 to 90
The reinforcing layer (10 in FIGS. 1 and 2) was formed by wrapping at 0 °. A taper portion whose thickness changes at an angle of about 6 ° was provided between the joint portion and the pipe portion. Then, the mandrel was placed in a thermosetting oven and cured at 150 ° C. for 2 hours while rotating. After curing, remove from the mandrel, cut off unnecessary parts at both ends, and have reinforcing layers at both ends, length 1100m
An FRP pipe (1 in FIGS. 1 and 3) having an inner diameter of 70.1 to 70.2 mm was obtained.

(2) Steel Connection Element (Yoke) As serrations on the outer peripheral surface of the joint of the steel connection element,
Serrations (also called knurls) were formed using the flat module (m) 0.3 specified in JIS B0951-1962. The cross section of the obtained serration (knurled eye) has an isosceles triangle with an apex angle of about 90 °, and the tip is flat.
It had a shape as shown in. The tooth height (h) of the serration is about 0.2 mm, and the pitch (p) is about 0.9.
It was 28 mm. The outer diameter of the joint to the tip of the serration tooth was 70.4 to 70.5 mm. That is, the df / dp ratio was in the range of 1.002 to 1.006.

(3) Production and evaluation of FRP driving force transmitting shaft The FRP driving force transmitting shaft of the present invention was produced using the FRP pipe and the connecting element produced as described above.
At the end of the FRP pipe, a joint having serrations of adhesive-bonded steel coupling elements was applied and press-fitted by hydraulic pressure. The joint length was set to 20 mm in order to relatively evaluate the torque transmission capability of the joint. When manufacturing an actual shaft industrially, it is possible to adopt a longer joint length according to the purpose so that the transmission torque of the joint is higher than the torsional breaking torque of the pipe. The static torsion test of the obtained FRP drive force transmission shaft was performed, and the results of evaluating the torque transmission capability of the joint are shown in Table 1.

The adhesives and protective layers used in the examples are shown below. -Adhesive: Taoka Chemical Industry Co., Ltd .: Epoxy adhesive Product name: Technodyne HT-18X (600 poise at room temperature) -Nonwoven fabric used for the protective layer (1) Glass surface mat: Asahi Fiber Glass ): Surface mats Product code: SM3600E (Basis weight 30 g / m ² ) (2) Glass scrim: Nitto Boseki Co., Ltd .: Electrical insulation cloth Product code: WE 106 104 (Basis weight 25 g /
m ² )

Comparative Examples 1 to 3 FR using protective layers of various materials shown in Table 2 in the same manner as in the above Examples except that no adhesive was used during bonding.
A drive force transmission shaft made of P was manufactured. The static torsion test was conducted in the same manner as in the example, and the results are shown in Table 2.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

The FRP drive force transmission shaft according to the present invention has a higher torque transmission capability than that obtained by simply engaging serration teeth without using an adhesive as shown in the comparative example. When the adhesive is not used together, as shown in Comparative Examples 1 to 3, a large load is required for press-fitting and fitting at the time of joining the coupling elements, and the torque transmission capability is poor. Also,
Since the FRP driving force transmission shaft of the present invention has a strong joint between the FRP pipe and the coupling element, the torque transmission is higher than that of simple friction joining or adhesive joining of cylindrical shapes, or joining of regular polygon shapes. It has the ability, and because of the filling effect of the adhesive, water is prevented from entering the joint gap, so it is less likely to corrode, and has excellent durability and environmental resistance. Further, compared to a regular polygonal joint, the joint is easier to process, and the joining process is extremely excellent in productivity.

As in Examples 3, 6 and 7, a protective layer having a circumferential elastic modulus of 30 GPa or less was used, and the ratio Ef / Em of the elastic modulus of the protective layer and the elastic modulus of the coupling element was 0.2 or less. And the ratio tf / h of the thickness of the protective layer and the height of the serration tooth is 5.
When the ratio is 0 or less, the ratio of the thickness of the joint portion to the thickness of the pipe portion tj / t
When p is 3 or less, Examples 1 and 2 having no protective layer,
Especially superior to 4 or 5.

The present invention is not limited to the driving force transmitting shaft,
The present invention provides a general method for joining FRP pipes and various types of joint parts, particularly metal joint parts, and is useful in the manufacture of various machines and equipment that utilize the light weight and high strength of FRP pipes. It is a thing.

[Brief description of drawings]

FIG. 1 shows an axial partial sectional view of an example of a fiber-reinforced resin drive force transmitting shaft of the present invention.

FIG. 2 is a partial cross-sectional view taken along the line AA (radial cross section) of the fiber-reinforced resin driving force transmitting shaft of FIG. The inside of the circle is an enlarged view of a part of the joining portion showing the joining state by biting of the serration.

FIG. 3 is a partial cross-sectional view in the axial direction of an example of a fiber-reinforced resin drive force transmitting shaft of the present invention in which a protective layer is provided on the inner surface (joint surface) of a fiber-reinforced resin pipe joint.

FIG. 4 shows two types (A and B) of examples of serrations used in the present invention.

FIG. 5 is an explanatory diagram of tooth height (h) and pitch (p) of serrations.

[Explanation of symbols]

 1. FRP pipe 2. Coupling element (steel yoke) 3. FRP pipe joint 4. 4. Joints of coupling elements FRP pipe joint surface 6. Joining surface of connecting element 7. Serration 8. Adhesive 9. Protective layer 10. Reinforcement layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location // B29K 105: 06 B29L 31:06 4F (72) Inventor Yasuo Shinohara 6 Sumitomo Kitahara, Tsukuba, Ibaraki Prefecture Chemical Industry Co., Ltd. (72) Inventor Hitoshi Murotani 6, Kitahara, Tsukuba, Ibaraki Prefecture Sumitomo Chemical Co., Ltd.

Claims (6)

[Claims] 1. A shaft for driving force transmission made of fiber reinforced resin, which is formed by joining a joint portion of a fiber reinforced resin pipe and a joint portion of a coupling element having an outer surface or an inner surface serrated. The joint portion of the fiber-reinforced resin pipe and the joint portion of the joint element are joined by the serration biting of the joint element into the joint portion of the fiber-reinforced resin pipe formed by press-fitting. A shaft for driving force transmission made of fiber reinforced resin, characterized in that the gap is filled with an adhesive. 2. A protective layer having a circumferential elastic modulus of 30 GPa or less is laminated on a joint surface of a joint portion of a fiber-reinforced resin pipe into which serrations of coupling elements are caught, and the serrations are caught in the protective layer. The fiber-reinforced resin drive force transmission shaft according to claim 1, which is formed through the shaft. 3. An intermediate portion of a joint portion of a fiber-reinforced resin pipe,
A reinforcing layer is provided on the outer surface or the inner surface, and the ratio (tj / tp) between the thickness (tj) of the reinforced joint and the thickness (tp) of the pipe.
The fiber-reinforced resin drive force transmitting shaft according to claim 1 or 2, wherein 4. When joining a joint portion provided at an end portion of a fiber-reinforced resin pipe and a joint portion provided at an end portion of a joint component, the inner surface or the outer surface of the joint portion of the fiber-reinforced resin pipe is joined. Is subjected to serration processing without applying serration processing to the outer surface or inner surface of the joint portion of the joint component, and applying an adhesive to the joint portion of at least one of the fiber-reinforced resin pipe and joint component. A fiber-reinforced resin pipe, wherein the joint part of the fiber-reinforced resin pipe is press-fitted to the joint part of the joint part or the joint part of the joint part is press-fitted. How to join parts. 5. The method for joining a fiber-reinforced resin pipe and a connecting component according to claim 4, wherein a protective layer having a circumferential elastic modulus of 30 GPa or less is laminated on the joint surface of the joint portion of the fiber-reinforced resin pipe. 6. The method for joining a fiber-reinforced resin pipe and a joining component according to claim 4, wherein the joining component is a joining element of a driving force transmitting shaft.