JPH0447001A - Soundproofing method for rail - Google Patents

Abstract

PURPOSE:To facilitate application to an existing rail, and to enable reduction in noise by fixedly fitting magnetic rubber sheets provided with grooves extending along the direction of the rail to the leg part of the rail so that they are stopped on the bottom surface and on the shoulder parts thereof by a clip. CONSTITUTION:A thin steel yoke 3 is integrally adhered by valcanization to the nonattaching surfaces of magnetic rubber sheets 2a, 2b that have been abutted on the rear surface 13a and on the shoulder parts 13b of the leg parts 13 of respective rails 12 positioned between ties 11 (not shown) in an existing railroad 10 (not shown) for forming a soundproofing means. Further, grooves 4 in parallel with the rail 12 are graved on the attaching surfaces of respective magnetic rubber sheets 2a, 2b, and a bow-shaped clip 5 for tightening use is pinchingly fitted by an expansion-resistant tension to the magnetic rubber sheets 2b of the shoulder parts 13b and to the rubber sheet 2a on the rear surface 13a, so that coming-off and blindly movement of the magnetic rubber sheets 2a, 2b due to vibration can be prevented. Thus, noise pollution can be reduced, and increase in transport efficiency can be enabled.

Description

[Detailed description of the invention] [Purpose of the invention]

(The following is a blank space) <Industrial Application Field> The present invention relates to a track soundproofing method. -Conventional technology'' (1) Background The noise emitted by railway vehicles has become a serious pollution problem in recent years, as seen along Shinkansen lines.An effective countermeasure to the second problem is to increase the running speed. However, the former inevitably leads to a decrease in driving efficiency, and is not compatible with the social situation where speeds are increasingly required.On the other hand, the latter is a considerable problem in the case of crushed stone roadbeds. However, in the case of iron bridges such as the Seto Taiyo, crushed stone roadbeds cannot be used for structural reasons, so even if a sound insulating wall is installed, it will not be enough to reduce the large echoing sound between the steel members induced from the rails. Therefore, in these sections, the only countermeasure is to reduce the driving speed, even if this means reducing transport efficiency.Therefore, it is necessary to develop technology to attenuate the rail noise itself during running. (2) Prior art By the way, the causes of vehicle running noise are complex, but most of it is thought to be caused by compressive deformation of the rails due to the load of the wheels.As a countermeasure, the rail structure There is a method of imparting vibration damping ability to the device itself. Examples include Japanese Patent Application Laid-Open No. 51-124210 and Japanese Patent Application Laid-open No. 52-1478.
Examples include those described in Publication No. 11. The former has a side gutter on both sides or one side of the rail, and inside this gutter,
By filling sound-absorbing solids or liquids such as concrete, sand, rubber, plastic, or water, and the latter by coating the sides and bottom of the rail with sound-absorbing materials such as rubber, polyurethane, or epoxy asphalt. , which attempts to absorb the vibration and noise of the rails, but since it requires large-scale construction to implement, it has not yet been put into practical use, so it is a soundproofing method based on a separate idea. The JR authorities have been testing a method of attaching damping rubber around the wheels, especially with the aim of reducing noise during the Seto Great Shake, but satisfactory results have not yet been obtained. Furthermore, constructing the wheels themselves from rubber is recognized as an effective countermeasure, but this method has not yet become widespread as a method for supporting high-speed, heavy-load vehicles due to its durability. OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a new soundproofing means that is easy to apply to existing rails and has a sufficient noise reduction effect.

[Structure of the invention]

[Means for Solving the Problems 2 (1) Concept As a result of repeated research into methods for effectively attenuating the noise generated by tracks, the inventors have found that if the tracks are tightly covered with a damping material such as rubber, The vibration damping material itself vibrates integrally with the rail and cannot exert an effective damping effect.
Therefore, it was confirmed that in order to dramatically increase the effectiveness of the damping material, it is necessary that the damping material itself be movably attached to the rail to some extent. Therefore, the present invention was developed as a result of research into a method for immediately and permanently attaching damping material to a rail. (Based on the knowledge outlined above, the track soundproofing method false to the present invention is:
It is characterized by surrounding the legs of the rail with magnetic rubber plates. The various requirements constituting the invention will be explained in terms below. (3) Magnetic rubber plate The characteristic structure of the track soundproofing method according to the present invention is that a magnetic rubber plate covers the bottom surface and the periphery of the rail in an indestructible manner. The term "magnetic rubber" here means a rubber or similar elastomer that has ferromagnetic properties that can be bonded to the rail as a whole.Therefore, powders of ferromagnetic materials such as iron, barium ferrite, and alnico are incorporated into the elastomer base material. In addition to kneaded so-called magnetic rubber, rubber composites obtained by growing various ferromagnetic substances on ordinary rubber in the form of a film by vapor deposition, sputtering, electrodeposition, etc. can also be used for the purpose.Adsorption to rails. In order to increase the
A rubber magnet containing ferrite costs approximately 24,000 yen. Shows a certain degree of holding power. It is preferable that the magnetic rubber has grooves 711 (grooves) in a direction parallel to the rail on its − surface (adsorbed surface).
The presence of this groove is effective in increasing the sound absorption effect.9 Normally, the grooves have a depth within 18 mm of the thickness of the magnetic rubber plate, and are preferably spaced at intervals of 5 to 10 m. provided. The width of the magnetic rubber plate, if constructed integrally, should be at least long enough to reach from one shoulder of the leg of the rail through the bottom of the leg to the other shoulder. It is. However, in consideration of the convenience of installation work and the flexibility of the magnetic rubber plate itself, this magnetic rubber plate is designed to be used for contacting the bottom of the rail leg and for contacting the shoulder, as shown in the examples below. It may be divided into different parts for different purposes. Note that the appropriate medium length naturally changes depending on the size of the target rail, that is, the number of kg. In addition, the length is unlimited for newly installed rails, but when applied to existing rails, the spacing between sleepers (usually 30 to 50 cm) is sufficient.Of course, for convenience of distribution, long lengths are required. (4) Auxiliary member (a) Yoke In order to avoid leakage of magnetic flux, a yoke made of a ferromagnetic metal plate such as iron may be provided if desired. Unless the rubber magnet contains a particularly ferromagnetic magnetic material such as a rare earth metal, the coercive force of a general rubber magnet is not so large due to the packing density etc. Adding a yoke is effective in applying magnetic force to the extent that it will not peel off even when subjected to severe vibrations from running.In experiments using ordinary rubber magnets, the addition of a yoke lowers the noise level by 3 to 5 dB. It is desirable that the yoke be separate from the magnet plate. If it is integrally molded during vulcanization, the installation work will be easier, but
(b) Clip Clips are added as necessary to securely attach the rubber magnet plate to the rail. Although the structure of the clip is arbitrary, the simplest form is a bow-shaped spring as shown in the embodiment below. In consideration of durability against rain and dew, the clip is preferably made of stainless steel or phosphor bronze. [Function] The water layer that has a noise damping effect on the track to which the construction method of the present invention is applied is thought to be approximately as follows. In other words, the vibrations of the rail caused by the passage of the vehicle are transmitted to the rail legs via the rail pillars, and then to the circumscribing magnetic rubber, but the magnetic rubber itself is not in close contact with the rail, and is transmitted to the rail's rough ground. The rubber plate is in almost point contact with the skin, and this point contact changes from moment to moment as the rubber plate vibrates. Therefore, the natural vibration of the rail is not directly transmitted to the magnetic rubber, but is mostly absorbed by the rubber layer. Also, some of the vibrations transmitted to the rubber layer cause the rubber to vibrate, and ultimately convert into thermal energy. Furthermore, while the noise components passing through the rubber layer pass through the rubber layer, the portion between 250 and 2000 H, which is sensitive to the human ear, is significantly attenuated. In particular, if a groove exists on the suction surface, the contact with the rail is completely cut off at the groove part, and at the same time, the resonance with the natural vibration of the rail is cut off, so the -layer damping effect is strengthened.6 Preliminary According to the results of a simulation test, the noise of the rails applied with the soundproofing method according to the present invention was 78 to 8 dB at a point 1 m from the sound source, compared to 104 to 107 dB for the control.
Remarkable results have been obtained with a reduction of up to 3 dB. It has been experimentally confirmed that attaching magnetic rubber plates to the rail pillars has little effect on noise attenuation. This is probably because the longitudinal vibrations caused by the passage of the vehicle are not converted into vibrations of the magnetic rubber plate. 7 Embodiment: Hereinafter, an embodiment of the track soundproofing method according to the present invention will be described with reference to the drawings, but the example is merely for explanation and is not intended or meant to limit the idea of the invention. do not have. FIG. 1 is a plan view showing an example of the case where the construction method of the present invention is applied to an existing track, and FIG. 2 is a partially enlarged sectional view taken along the line XX direction in FIG. 1. In this example soundproofing method, each sleeper 11, 1 on the existing track 10
1. Applies to each rail 12.12 located between. The main body of the soundproofing means 1 is a magnetic rubber plate 2a having a thickness of about 51 mm and abutting against the back surface 13a and shoulder portion 13b of the leg portion 13 of each rail.
: 2b, 2b, with a thickness of approximately 1+ on the non-adsorption surface (outer surface) of each magnetic rubber plate! Eleven thin iron plate yokes 3 are integrally vulcanized and bonded to each other;
Grooves 4, 4, . . . parallel to the rail 12 are carved on the adsorbed surface (inner surface) of 2b. The fastening bow-shaped clip 5.5 clamps the magnetic rubber plates 2b, 2b of the shoulder portion 13b and the rubber plate 2a of the back surface 13a by their anti-expansion force, and the magnetic rubber plate 2a is vibrated. The soundproofing method of this example, which prevents the falling off and unintentional movement of the 2b, is extremely easy to apply to existing tracks, so it can be used to reduce noise pollution caused by railways, especially on railway bridges and guardrails where it is difficult to install sound insulating walls. This has a great effect on reducing noise caused by (Margin below)

【Effect of the invention】

As explained above, the present invention can reduce noise pollution by providing a new soundproofing means that is easy to apply to existing tracks and has a sufficient noise reduction effect, and further improves transport speed by increasing operating speed. Contributes to increased efficiency.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of the case where the construction method of the present invention is applied to an existing track, and FIG. 2 is a partially enlarged sectional view taken along the line XX direction in FIG. 1. The meanings of the symbols in the diagram are as follows: □ 1: Soundproofing means of the present invention ・2: Magnetic rubber plate of 1 ratio ・2a: Magnetic rubber plate on the back side of the leg of the rail: ・2b = Magnetism on the shoulder of the leg of the rail Rubber plate: ・3: Yoke; ・4 Niger loop: ・5: Clip: 10: Track 11: Sleeper 12: Rail: 13: Leg; 3a: Back side, 13b = Shoulder

Claims (1)

[Claims] 1. A soundproofing method for tracks, characterized by attaching magnetic rubber plates to the legs of the tracks. 2. The construction method according to claim 1, wherein the magnetic rubber plate is provided with a groove along the direction of the rail. 3. The construction method according to claim 1 or 2, wherein the magnetic rubber plate is fixed to the rail with a clip. 4. The construction method according to any one of claims 1 to 3, wherein the magnetic rubber plates are attached to the bottom and shoulders of the legs of the rail. 5. The construction method according to any one of claims 1 to 4, wherein the magnetic rubber plate is attached to a rail between sleepers of an existing track.