JP2007303104A - Insulating plate for rail joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating plate for a rail joint withstanding long-term use, wearing little and enabling the degree of wear to be found early to maintain safe operation of trains. <P>SOLUTION: The insulating plate inserted between a rail fish plate and a rail to insulate the rail at a joint part is formed by impregnating liquid epoxy resin into synthetic fiber cloth of excellent pressure-proof strength and wear-proof strength formed of a plurality of layers, laminating the cloth to obtain a predetermined thickness, and heating, pressurizing and hardening it. The insulating plate for fastening the rail has a colored layer colored in a different color from an upper face and a lower face and arranged in an intermediate layer of the insulating plate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  Rail joints in railways are a weak point in the railway system. The joint portion of the rail is brought into contact with the joint plate from both sides of the rail, and both plates are firmly fastened and fixed by a plurality of screws. The present invention relates to a joint insulating plate used for a joint portion of a rail.

  Insulation plates for railway rail joints are known to be made of nylon resin as a raw material and molded by an injection molding method, but when this product reaches a fastening force of 3000 Kg / ton or higher when the rail is fastened, the pressure limit of the nylon plate is reached. It will be difficult to maintain the rail fastening force. For this reason, it is necessary to follow up timely after installing the plate, but it is rolled during train operation and the plate material deteriorates and breaks down, causing insulation failure and hindering train operation. Was impossible.

  On the other hand, in Japanese Patent No. 2551526 (Patent Document 1), a high-modulus vinylon cloth and an aramid fiber cloth, which are alternately laminated, have a pressure-resistant and wear-resistant layer as a core layer, and the upper and lower surfaces of the low-modulus vinylon cloth. There is disclosed an insulating plate which is formed as a pressure absorbing portion by being layered and impregnated with an epoxy resin as a whole and integrally heated, pressurized and molded in a mold.

  In railroad rail insulation plates, the degree of wear after installation can be inspected mainly in the areas where frequent operation is performed after the end of the vehicle, so visual appearance evaluation can be performed. Since wear due to such a complicated load occurs, it is very difficult to measure the wear degree using a measuring tool. Therefore, the appearance of an insulating plate for a rail joint that can withstand long-term use for safe operation is desired.

Japanese Patent No. 2551526

  In railroads, if rails and rail joints are not reliably insulated, train operation will be hindered, which may lead to serious accidents. Insufficient insulation at the rail joints rarely occurs at the beginning of the rail connection, but the insulation plate gradually wears out in long-term, frequently operated suburban areas, subways, etc. There is. As described above, it is possible to check the degree of wear after installing the insulation plate mainly in the areas that are frequently operated as described above, so it is possible to evaluate the appearance by visual inspection, but the plate wear is complicated on the rail joint. Therefore, it is very difficult to measure the degree of wear using a measuring tool. Therefore, in order to maintain safe operation, a rail joint insulating plate with little wear that can withstand long-term use and can detect the degree of wear at an early stage is expected.

The present invention is a rail joint insulation plate to be inserted between a rail joint plate and a rail in a railroad, impregnated with a liquid epoxy resin into a synthetic fiber cloth excellent in pressure resistance and wear resistance, and laminated to a predetermined thickness, In the rail joint insulating plate formed by heating and pressure curing, the intermediate layer of the insulating plate is the rail fastening insulating plate in which a colored layer colored in a color different from the intermediate layer is arranged on the upper surface and the lower surface.
Furthermore, this invention exists in said insulating plate for rail fastening in which the colored layer by the color of the fiber raw material which forms the insulating plate differs from another fiber raw material is formed.

  According to the present invention, the rail joint insulation plate according to the present invention is significantly superior in load capacity compared to conventional products, has less plate wear, and can be used to determine the degree of wear and to evaluate maintenance and inspection by visual inspection based on hue. The plate replacement time can be accurately grasped, and the physical properties are superior in hardness and compressive stress at 20% strain, and the train safety can be maintained for a long time, contributing to the safe operation of the train.

  The insulating plate for rail joints of the present invention has the above-described configuration, and the intermediate layer made of fiber cloth is mainly composed of thick denier polyethylene terephthalate or polyethylene terephthalate (hereinafter abbreviated as PET fiber). ) A thick cloth layer in which several layers of long fiber cloth are stacked is used. The thickness of the intermediate layer is preferably about 1.3 to 1.4 mm in a state impregnated with a liquid epoxy resin (before curing).

  The both sides of this intermediate layer are sandwiched between layers made of the same PET fibers used for the intermediate layer or other cloth made of high-strength synthetic fibers to form three layers of upper and lower layers and intermediate layers, or further above and / or below A multilayer including one layer may be used. The total thickness of the fiber cloth layer is approximately 4.5 to 5 mm. Examples of other synthetic fibers that can be used together with or in place of PET fibers include aramid fibers.

The fiber layer laminated as described above is impregnated with a liquid thermosetting resin or resin solution, the excess liquid is squeezed, the resin content after curing is in the range of 40 to 45% by mass, and placed in a plate mold. Press, heat and cure. The heating pressure is about 10 K / cm ² and the heating is in the range of 90 to 110 ° C. for 15 to 20 minutes. The thickness of the plate after heat curing is in the range of 2.8-3 mm. A liquid epoxy resin is preferably used as the thermosetting resin.

Hereinafter, the present invention will be described in more detail with reference to examples. First, test items and test methods used for evaluation of the present invention are shown below.
“Loading test”: Using a high-frequency dynamic characteristic measuring device KC-V-2 manufactured by Kinomiya Seisakusho Co., Ltd., the loading surface was a surface of 30 ± 0.2 mm × 10 ± 0.3 mm of the test piece.
Loading force: 10 ± 6kN
Loading frequency: 10Hz with sine wave
Loading frequency: 1 × 10 ⁷ times.
In this loading test, 30 million tons per year of a general metropolitan suburban railway line = 2.94 × 10 ⁸ kN. This loading test condition is estimated to correspond to a load condition of about 6.5 years on an actual track in the suburbs of a large city.
“Hardness measurement”: Measured according to JIS K7215.
“Compression test”: The test was performed according to JIS K6911 and JIS K7181.
“External appearance observation”: Investigation was made on the observation shape of the test piece after 1, 2.5, 5, 7.5 × 10 ⁶ times and 1 × 10 ⁷ times of loading test, and whether there were any abnormalities such as cracks and irregularities. .
“Test specimen dimensions”: After the loading test under the same conditions as the above-mentioned appearance observation, the width, length and thickness of the test specimen were measured with calipers, but the thickness was measured using a thickness meter.

Example 1
For forming the insulating plate, it was a polyester fiber cloth manufactured by NI Teijin Shoji Co., Ltd., and the warp and weft yarns were made of 1500 d polyethylene terephthalate with a thickness of 0.53 mm per 47 cm and a tensile strength of 3560N. As shown in the model in FIG. 1, the elongation rate is 23.2% in the background direction, and the structure is a: 3 layers, b: 2 layers, c: 3 layers. Layers C and C were uncolored (raw yarn), and the red layer was a red-colored cloth layer. Next, a cross-layer obtained by laminating “b: 2 layers” between the layers i, b, and c so as to have a thickness of 3 to 3.5 mm is a liquid epoxy manufactured by Aika Co., Ltd. A cloth impregnated with a resin (trade name “Acmex” L2626), squeezed so that the amount of resin is 45% of the fiber mass, and then forcedly impregnated to the end of the fiber layer in a vacuum furnace with the configuration of FIG. The product was placed in a mold, pressed and heated to obtain an insulating plate having a thickness of 3 mm.

(Example 2)
Aramid fiber cloth instead of the polyester fiber cloth used in Example 1 as an insulating plate forming cloth. However, the number of driving is 17 (5 cm), the strength warp / weft 230.5 (N), the elongation 4.5%, the thickness A 3 mm cloth layer is impregnated with the same epoxy resin as in Example 1, and the layer B shown in FIG. 1, that is, the intermediate layer, is composed of the polyester fiber cloth described in Example 1 in four layers. An aramid fiber cloth layer was provided, and an insulating plate having a thickness of 3 mm was formed by pressing, heating, and molding in the same manner as in Example 1.
In this example, the fibers used in each of the cross-layers i, b, and c used were not colored and remained as a fabric. As a result, against the brown aramid fiber cloth fabric, the polyester fiber cloth used in (a) and (c) is white, and when used as an insulating plate as a mounting product, the cross layer thickness is seen by observing the cross layer thickness. Could be identified visually.

Next, the physical property test and the repeated compression loading test were compared for the insulating plate of the present invention obtained in Example 1 and the conventional nylon insulating plate. As for the loading conditions of the loading test, 1 × 10 ⁷ loading tests corresponding to 6.5 years were conducted assuming a standard track of a metropolitan suburban line. Each test item is hardness, measurement of compressive stress at 20% strain, change in thickness, and appearance observation after completion of the test.
The results are shown in Tables 1-4.

  Table 1 shows the change in hardness before and after the load measurement test, Fig. 2 shows the thickness reduction rate after the load measurement test, Table 2 shows the change in dimensions before and after the load measurement test, and Table 3 shows the identification judgment for maintenance management inspection. Table 4 shows the compressive stress at 20% strain.

[Hardness results from loading test]

[Dimensional change before and after loading test]

[Identification of maintenance management inspection]

[Compressive stress at 20% strain]

  According to the present invention, in a railway in which safety is most important, it is possible to detect early and surely the change in the thickness of the plate layer by visually observing the wear of the insulating plate at the joint portion of the rail forming the foundation. As a result, it is possible to prevent accidents and the like, and as a result, safe operation of the train can be secured over a long period of time.

It is a schematic diagram of the cross section of the insulation plate for rail joints of the present invention. It is a graph which shows the decreasing rate of the thickness by the loading test of this invention.

Explanation of symbols

In FIG. 1, reference numerals 1 and 3 denote PET fiber cloths constituting the plate, and 2 denotes a high-strength fiber cloth layer forming the center of the plate layer.
In FIG. 2, the vertical axis indicates the thickness reduction rate, and the horizontal axis indicates the number of times of vibration in the loading test. Symbol a represents the product of the present invention, and b represents the curve of a conventional product (made of nylon).

Claims (2)

  A rail joint insulation plate that is inserted between rail joint plates in railroads, impregnated with liquid epoxy resin in a synthetic fiber cloth with excellent pressure resistance and wear resistance, laminated to a predetermined thickness, heated and pressed In a rail joint insulating plate formed by hardening, an insulating plate for fastening a rail is formed by arranging a colored layer colored in a color different from that of the intermediate layer on an upper surface and a lower surface of the intermediate layer of the insulating plate. 2. The rail fastening insulating plate according to claim 1, wherein a colored layer is formed by the color of the fiber material forming the insulating plate being different from that of other fiber materials.

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