JPH06346401A - Rail joint member - Google Patents

Abstract

PURPOSE:To enhance workability by weight reduction and prevent a drop in insulation properties resulted from aging and protect an area around an insertion hole of a fastener, such as bolts from being cracked with regard to a rail joint material which is used to connect each of railway rails in the longitudinal direction. CONSTITUTION:Joint materials 2 are made of fiber-reinforced synthetic resin where a plurality of penetration holes 24 are bored in the transverse direction. A short pipe 25 is inserted into the penetration hole 24. An inner hollow part of the short pipe 25 is used as a penetration hole 23 of a fastener 3. This short pipe 25 is formed with a raw material whose bending elastic modulus is lower than that of the joint member 2. Therefore, this joint material is light weight and protected from a drop in insulation performance resulted from aging, and what is more, the inner peripheral part of the fastener's insertion hole 23 is formed with a raw material, which is rich in flexibility. This construction makes is possible to prevent the generation of cracks in an area around the penetration hole 23 even when concentrated stress is exerted on the area and provide safety as a joint member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rail joint member used for connecting rails adjacent to each other in the longitudinal direction in the field of railways and the like.

[0002]

2. Description of the Related Art Generally, for connecting rails for rails in the longitudinal direction, a seam member is arranged at the connecting portion so as to straddle the side surfaces at the end portions of both rails. The seam member and the end of the rail are connected by tightening with a tightening tool such as a bolt.

Such a rail connecting portion is the weakest portion of the rail, and mechanical stress such as repeated impacts and vibrations is applied by the passage of a train. Therefore, for connecting and reinforcing the rail at this portion. As the seam member used,
The one made of steel was used conventionally. However, the weight of each steel seam member is usually 20 to 30K.
Since the weight was g, the workability of mounting on the rail was difficult because the weight increased.

On the other hand, the rails used at the locations where traffic lights and level crossing alarms are installed need to be divided into certain sections to form an electric circuit. Therefore, the rail joint members are also required to have insulating properties. There are cases.

Conventionally, as a rail joint member having this insulating performance, as shown in FIG. 5, the joint plates b, b arranged on the side surface of the rail a are prevented from coming into contact with the rail a.
Insulating plates c, c made of synthetic resin are interposed between the two, and as the tightening bolt insertion hole d, a through hole is preliminarily formed thick and synthetic resin insulating cylinders e, e are fitted therein from the left and right. It is known that the insulating cylinders e and e have a hollow inside to form a tightening bolt insertion hole d to ensure the insulation property (issued by Sankaido Co., Ltd. on November 30, 1990, “Track-track”). Design and management ", page 82, Figure 2.52). In the figure, f is a flange extending from the head of the insulating cylinder e, g is a washer, h is a nut, and i is a bolt.

In this insulating joint member, since the insulating plate c and the insulating tube e are made of synthetic resin, the weight is slightly lighter than that of steel, but the insulating plate c and the insulating tube e are not. However, due to repeated shocks and vibrations due to passing trains, and thermal expansion and contraction of rails due to changes in temperature, the rails may be worn or damaged over time, and there is a risk that the insulation may deteriorate. As described above, the conventional seam member is heavy including the insulative seam member, and in the insulative seam member, there is a problem that the insulating function of the insulating plate and the insulating cylinder deteriorates with the lapse of time.

Therefore, the inventors of the present invention solve these problems by producing the seam member itself from a fiber reinforced synthetic resin, and not only in the case of the above-mentioned use where the insulating property is particularly required, but also when it is insulated. Even so, it was focused on that a useful member can be obtained as a joint member used in a place where there is no obstacle.

However, since the tightening bolt at the time of rail connection is tightened with a high torque, a high compressive stress is generated in the thickness (width) direction of the joint member, and the stress is concentrated around the bolt insertion hole. It was predicted that cracking due to cracking would be unavoidable.

[0009]

DISCLOSURE OF THE INVENTION The present invention is to improve the above-mentioned problems of the prior art, that is, to reduce the weight and solve various problems related to heavy objects such as workability and workability, and to provide an insulating function with the passage of time. The purpose of the present invention is to prevent the occurrence of cracks in the insertion holes of tightening tools such as bolts, and to provide a product with a long life and safety even when used for a long period of time.

[0010]

According to the present invention, "a rail extending continuously from a rail is provided so as to straddle both side surfaces of an end portion of the rail, and an insertion hole for a tightening tool is provided in the width direction. Which is made of fiber reinforced synthetic resin, has a plurality of through holes formed in the width direction, and a short tube is inserted into the through holes to form an insertion hole for a tightening tool. The gist of the short pipe is a seam member for rails characterized in that the short pipe is made of a material having a bending elastic modulus lower than that of the seam member.

That is, by manufacturing the rail joint member itself from fiber reinforced synthetic resin, the weight of the whole is reduced, and the insulating joint member is conventionally formed of two members of steel and synthetic resin. The deterioration of the insulation performance due to the passage of time is eliminated, and the insertion holes for tightening tools such as bolts, which are provided in the rail joint member, reinforce the inner peripheral wall to prevent the occurrence of cracks due to stress concentration. To prevent this, insert a short tube made of a material with a lower bending elastic modulus than the seam member into the through hole that was drilled in advance, and use the hollow inside of the short tube as the insertion hole for the tightening tool. Is the main point.

According to the first aspect of the present invention, as a method of forming the insertion hole of the tightening tool, a through hole having a diameter slightly larger than that of the insertion hole of the tightening tool is provided in advance in the thickness (width) direction of the joint member. As described above, it is necessary to fit a short tube having a predetermined inner diameter as the insertion hole of the tightening tool into the through hole. Moreover, this short pipe needs to be formed of a material having a lower bending elastic modulus than the material forming the joint member.

The reason why a material having a low flexural modulus is selected is as follows. Generally, the elastic modulus in the three-point bending test is calculated by the following equation 1.

[0014]

[Equation 1]

Where Ef is the flexural modulus (Kgf / mm ² ), L
= Distance between fulcrums (mm), b = Width of test piece (mm), h = Height of test piece (mm), F = Load-Load at arbitrary selected point of the first straight line portion of the deflection curve (Kgf ), Y = deflection at load F
(mm).

Now, assuming that L ³ , b, h and F are constant, Ef and Y have an inversely proportional relationship. That is, the higher the flexural modulus, the smaller the flexure, and conversely, the lower the flexural modulus, the larger the flexure. Therefore, the lower the flexural modulus, the greater the flexure and the greater the flexibility.

According to the second aspect of the present invention, the short pipe is formed of multiple pipes, and the tubular body located inside needs to be formed of a material having a lower bending elastic modulus than the tubular body located outside. is there. In this way, if the pipes that have different bending elastic moduli and are located on the inner side are arranged with a material that has a gradually lower bending elastic modulus, the stress diffuses due to the multiple pipe body, and the inner pipe is further expanded. Therefore, the effect of preventing cracks from being formed from the positioned tubular body becomes greater. However, the more pipes are used, the greater the degree of stress diffusion, but on the other hand, the processing becomes complicated and the processing cost increases, so if multiple pipes are adopted, double pipes and triple pipes should be used. It is good to set the degree.

In the fiber-reinforced synthetic resin constituting the rail joint member of the present invention, non-conductive fibers are recommended as the reinforcing fibers used. Specific examples thereof include glass fiber, aramid (wholly aromatic polyamide) fiber, vinylon fiber and the like, and glass fiber is particularly preferable because it is inexpensive and has strength. The most common form of fiber used is roving, but a cloth woven into plain weave, satin weave, etc., or a mat such as chopped strand mat, surface mat, and continuous mat made into a non-woven fabric with a binder. The kind is mentioned.

Among them, the cloth generally has both the fiber direction along the longitudinal direction of the seam member and the fiber direction along the width direction. Therefore, when a cloth having such a material constitution is used, It is effective in dispersing stress concentration in the insertion holes and developing durability against surface pressure caused by bolts and nuts.

Since the joint member of the present invention is subjected to repeated load in the vertical direction due to passage of a train, it requires high bending strength to cope with such a severe situation. For this reason, as the reinforcing fibers, if possible, it is better to arrange linear long fibers in the longitudinal direction of the joint member. The linear long fiber may have linearity such as glass roving or glass cloth, and the long fiber is generally used in the production of fiber-reinforced synthetic resin molded articles.
Fibers with a length of 30 mm or more, in this case 250
Fibers of mm or more (approximately one-half or more of the length L of FIG. 3 (a)) are preferable, and more preferably, fibers that are continuous from end to end of the seam member, that is, the length of FIG. It is preferable to use a fiber having a length substantially equivalent to L, and this corresponds to roving, woven fabric, knitted fabric, and the like.

The volume content of the reinforcing fiber in the present invention is preferably in the range of 20 to 70%, 20
If it is less than%, it is difficult to develop the required strength, and if it exceeds 70%, the thermosetting resin that binds and fixes the fibers to each other is relatively small, and again the required strength is not sufficiently developed. Becomes Further, the volume content of the long fibers with respect to the entire reinforcing fibers is preferably 50 to 80%.

Further, in the joint member of the present invention, friction of the contact surface with the rail is severe, and further high contact pressure is applied to the contact surface with the tightening tool such as a bolt. In some cases, carbon fiber, Alternatively, a resin layer having reinforcing fibers made of fibers having excellent abrasion resistance such as aramid fibers may be laminated to a thickness of 1 mm or more.

In the present invention, examples of the synthetic resin used as the matrix include thermosetting resins such as unsaturated polyester resin, vinyl ester resin, epoxy resin, phenol resin, urethane resin and urethane phenol resin. A vinyl ester resin that is excellent and has excellent physical properties such as tensile strength, compressive strength, impact strength, and elongation is suitable.

The cross-sectional structure of the seam member of the present invention is, for example, a two-layer structure of a core layer and a skin layer, and the core layer is made of a lightweight polyurethane foam reinforced with reinforcing fibers, The skin layer may also consist of a vinyl ester reinforced with reinforcing fibers.

The shape of the joint member of the present invention is, for example, as shown in FIG.
Generally, the upper part 2 on the side contacting the rail 1 as shown in 2
1 and the lower portion 22 are smoothly abutted on the side surface of the rail, and the central portion is formed so as not to be in close contact with the rail, but the shape is not limited to this. Also,
Regarding the dimensions of the seam member 2, for example, the length L in FIG. 3A is about 500 to 1000 mm, and the height H is about 100 mm.
The thickness T is about 40 mm, but is not limited to such a flat type. Further, the hole diameter, the interval, the number of holes, etc. of the insertion holes of the tightening tool are determined by the rail design and are not limited.

In the present invention, as the material for forming the short tube, a so-called sheet obtained by impregnating and mixing glass fiber with a thermoplastic resin such as polypropylene or acrylonitrile-butadiene-styrene (abbreviation ABS) or an unsaturated polyester resin is used. Examples thereof include molding compound (SMC) or bulk molding compound (BMC). Examples of the method for manufacturing the short tube include methods such as injection molding, extrusion molding and press molding.

As the method for producing the seam member of the present invention, conventionally known fiber-reinforced synthetic resin molding methods such as a pultrusion molding method, a press molding method and a reaction injection molding method can be adopted. Among these, the pultrusion molding method, which is excellent in productivity and stackability, is preferable.
In the case of the pultrusion method, the reinforcing fibers impregnated with thermosetting resin are aligned and heated in a mold having an inner surface shape that matches the cross-sectional shape of the seam member while continuously transferring and heating. After being hardened and pulled out, it is cut into a predetermined size, and then a through hole is formed using a perforation tool such as a drill. Naturally, the diameter of the through hole is set larger than that of the insertion hole of the tightening tool. Then, the separately manufactured short tube is fitted into the through hole using a press or the like.

The fixing of the joint member 2 to the rail 1 according to the present invention does not require an insulating plate or an insulating cylinder as in the conventional insulating joint member as shown in FIGS. That is, in FIG.
As shown in FIGS. 1 and 2, the rail 1 and the end portions 13, 13 of the rail 1 which are continuous with each other are straddled with the bolt insertion hole 14 and the joint member as shown in FIGS. 2 so that the positions of the insertion holes 23 of the tightening tool are overlapped and applied to the rail 1 from the left and right of the column portion 11 of the rail, the bolt 3 is inserted into the bolt insertion hole 14 and the insertion hole 23 of the tightening tool, and the washer 4 is attached. The nut 5 is fixed by screwing and tightening it.

When used as an insulating joint member, as shown in FIG. 4, in the gap 12 between the rails 1,
The cross-section used conventionally is almost the same as the rail 1,
For example, it is preferable to interpose an insulating rail mold 6 such as a paper impregnated with phenol resin to prevent direct conduction between adjacent rails.

The rail joint member of the present invention is preferably used for the conventional insulating joint member, but it is of course possible to use it as an ordinary joint member.

[0031]

Since the rail seam member of the present invention is made of a fiber reinforced synthetic resin, it is lightweight and is mainly made of a non-conductive material, so that there is no fear of deterioration of the insulation performance with time.

Further, the insertion hole of the tightening tool such as a bolt, which is provided in the rail joint member, is made of a material having a lower bending elastic modulus than that of the joint member because the inner peripheral wall of the insertion hole is reinforced. Since the formed short tube is fitted into the through hole that has been drilled in advance and the hollow inside of the short tube is used as the insertion hole of the tightening tool, cracks may occur even if stress is concentrated in the insertion hole. Absent.

[0033]

Embodiments of the present invention will now be described in detail with reference to the drawings. Example 1

First, by using the following raw materials, the raw material of the rail joint member having a shape as shown in FIG. 3 and having a height H of 100 mm, a thickness T of 40 mm and a length L of 560 mm. 3 is manufactured by a pultrusion method, and as shown in FIG. 3 (a), through holes 24 (diameter = 30 m
m) was drilled.

That is, the reinforcing fiber is dipped in a liquid thermosetting resin mixed with a curing agent, and the reinforcing fiber is provided with a mold (not shown) having an inner surface shape adapted to the cross-sectional shape of the seam member 2 of FIG. 1m) while heating, mold temperature 160 ℃,
At a molding speed of 20 cm / min, the mold was pulled out in the longitudinal direction to be cured, and cut into a standard size.

Details of the raw materials used at this time are as follows. Reinforcing fiber: Asahi Fiber Glass made glass roving #
4450 (weight 4.45g / m, filament diameter 13μ
m) Asahi Fiberglass Glass Cloth # 600 (weight 6
00 g / m ² , filament diameter 13 μm) Carbon fiber continuous mat # 450 (weight 450 g / m ² , filament diameter 13 made by Asahi Fiber Glass Co., Ltd.
μm) Resin: Vinyl ester resin (epoxy acrylate resin) Curing agent: Peroxide (t-butylperoxybenzoate)

The reinforcing fiber at this time was heated and cured by supplying the above resin while arranging the continuous mat, the glass cloth, and the glass roving so as to be repeatedly stacked in this order, but the uppermost layer and the lowermost layer were The reinforcing fibers were arranged so as to form a mat. The content of reinforcing fibers in the obtained seam member was 50% by volume, and the content of long fibers in the fibers was 75% by volume (roving = 45% by volume and cloth).

On the other hand, a sheet-shaped reinforcing fiber is impregnated with a liquid curable resin to prepare an SMC, which is attached to a press-molding die which is composed of an upper die and a lower die and can be formed into a cylindrical shape, and heated. -Pressurized to form a short tube.

Details of the raw materials for the SMC used at this time are as follows. Reinforcing fiber: Chopped strand made by Asahi Fiber Glass Co., Ltd. (glass roving # 4450 cut to a length of 25 mm) Resin: Unsaturated polyester resin Curing agent: Peroxide (t-butylperoxybenzoate) Filler: Calcium carbonate

The mold temperature at this time is 15 for the upper mold.
The temperature was 0 ° C., the lower mold was 135 ° C., and the pressing time was 180 seconds.
Also, the fiber weight content of the used SMC is 21-26%.
The obtained short tube has an outer diameter of 30 mm and an inner diameter of 21 m.
m, and the flexural modulus was 1000 Kg / mm ² .

Next, the short pipe 25 is press-fitted into the through hole 24 by using a press machine to obtain the seam member 2 according to the first aspect of the invention as shown in FIGS. 1 and 3B. .

Example 2 The diameter of the through hole 24 was expanded to 43 mm, and the short tube 25 was made of polypropylene extruded, and had an outer diameter of 27 mm, an inner diameter of 21 mm, and a bending elastic modulus of 5 kg.
Made of the same material as the inner tube 25a of / mm ² and the short tube of the first embodiment, the outer diameter of which is 43 mm and the inner diameter is 27 mm.
Example 1 except that it is a double tube with the outer tube 25b of
In the same manner as above, a seam member 2 of the invention according to claim 2 was obtained as shown in FIGS. 2 and 3C.

Comparative Example A seam member was manufactured in the same manner as in Example 1 except that a through hole having a hole diameter of 21 mm was used as an insertion hole for a tightening tool.

With respect to the joint members obtained in each of the above-mentioned Examples and Comparative Examples, the degree of weight reduction was evaluated and the bending load test was conducted. The results are shown in Table 1.

[0045]

[Table 1]

The bending load test was carried out according to JIS K7203. The position of the load and the direction of the load in that case are as shown by the arrows in FIG.

As is clear from the results of Table 1, the joint member of the present invention is improved in bending load to a practically sufficient extent.

[0048]

The rail joint member of the present invention is lightweight because it is made of fiber reinforced synthetic resin, and since the whole is a non-conductive material, the insulation performance does not deteriorate with time.
Therefore, the workability is improved, the construction cost can be reduced, and the quality of the joint member for the insulating rail is excellent.

Further, the insertion hole of the tightening tool such as a bolt, which is provided in the rail joint member, is formed of a material having a lower bending elastic modulus than the joint member in order to reinforce the inner peripheral wall thereof. The short tube is inserted into a through hole that has been drilled in advance, and the hollow inside of the short tube is used as the insertion hole for the tightening tool, so cracks are prevented from occurring even if stress is concentrated in the insertion hole. it can.

Therefore, even if concentrated stress acts around the insertion hole of the tightening tool for a long period of time, it does not crack and the man-hours required for maintenance and management after construction are reduced, so that the rail connection and
The cost required for maintenance can be reduced. In addition, because of its excellent quality, it is excellent for safe train operation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the invention described in claim 1 together with its usage.

FIG. 2 is a cross-sectional view showing another embodiment of the same as above, together with its mode of use.

3 (a) is a perspective view showing a raw material of a seam member used in the above, and FIG. 3 (b) is a perspective view showing a raw material of a seam member shown in FIG. FIG. 3 is a perspective view showing a process of forming the joint member of the invention of claim 1 shown in FIG. 1, and FIG. 3C is a perspective view showing a process of forming the joint member of the invention of claim 2 in the same manner. Is.

FIG. 4 is a side view showing a connection portion of two rails made by using the joint member of the present invention, and also a view showing a position and a direction to apply a load when a bending load test is carried out. .

FIG. 5 is a cross-sectional view showing an example of a conventional product together with its usage mode.

[Explanation of symbols]

 1 rail 2 seam member 3 bolt 4 washer 5 nut 11 pillar 12 gap 13 end 14 bolt insertion hole 23 tightening tool insertion hole 24 through hole 25, 25a, 25b short pipe

Claims (2)

[Claims] 1. A rail and a rail which are continuous at a distance,
A rail seam member that is disposed across both side surfaces of an end portion and has an insertion hole for a tightening tool in the width direction, and is formed of fiber reinforced synthetic resin. A through hole is bored, a short tube is fitted in the through hole to form an insertion hole for a tightening tool, and the short tube is formed of a material having a bending elastic modulus lower than that of the joint member. A characteristic rail joint member. 2. The short tube is formed of multiple tubes, and the tube located inside is made of a material having a lower bending elastic modulus than the tube located outside. Rail joint material.