JP2012017653A - Soundproof device for rail - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent noises with frequencies in all bands, particularly frequencies of about 1250 Hz.SOLUTION: A required portion of a surface of a rail R is internally and externally covered with a sound absorbing mat 111 and a sound insulation cover 113. The sound absorbing mat 111 has a cross-section which assumes a rectangular shape in a free state. The sound absorbing mat 111 is then obliquely placed from a side surface of a rail web Rw to a top surface of a rail bottom Rb, so that upper and lower portions of an inner surface brought into contact with the rail R are compressed by being pressed against the rail R.

Description

  The present invention relates to a rail soundproofing device for preventing noise generated from railroad rails.

  As this type of rail soundproofing device, a damping sheet is attached to the side surface of the rail, and the damping sheet is made of a multilayer damping material having a viscoelastic layer and a constraining layer ( For example, see Patent Document 1).

  Further, a rail soundproofing device including a sound absorbing mat and a sound insulating cover is also known (see, for example, Patent Document 2).

JP-A-6-101201 Japanese Utility Model Publication No. 3-2001

  There are frequencies that are difficult to improve depending on the rail shape and sleeper pitch. For example, in the case of the “50 kg N rail” defined in JISE1101 and the sleeper pitch “600 mm”, a frequency that is difficult to improve appears at 1250 Hz, but a technique for improving this frequency is required.

  An object of the present invention is to provide a rail soundproofing device that can prevent noises of all frequencies generated from the rail, and that is particularly effective even at around 1250 Hz.

  In the rail soundproofing device according to the present invention, a sound absorbing mat and a sound insulating cover are coated on the inside and outside of a required portion of the rail surface, and the sound absorbing mat has a rectangular cross section when free. The upper and lower portions of the inner surface that contact the rail are compressed by being pressed by the rail.

  In the rail soundproofing device according to the present invention, the energy of the sound reflected by the sound insulation cover is efficiently absorbed by the sound absorbing mat. Therefore, sound can be effectively prevented even at a frequency of around 1250 Hz, which is difficult to sound-proof only with the vibration damping sheet.

  The sound insulation cover may have a flat plate portion whose upper end portion is positioned at the upper end portion of the side surface of the rail abdomen and passed over the top end portion of the rail bottom surface.

  Furthermore, if a vibration damping sheet is interposed between the rail surface and the back surface of the sound absorbing mat, a considerable vibration damping effect can be obtained by the vibration damping sheet.

  Further, when the rail surface and the peripheral edge of the sound insulation cover are in contact with each other without any gap, sound leakage can be prevented, and the sound absorption effect by multiple reflection in the sound insulation cover can be further enhanced.

  The amount of the sound absorbing material that forms the sound absorbing mat is not particularly limited, but is preferably 15% or more of the volume in the sound insulating cover. A sufficient soundproofing effect can be obtained when both are in contact with each other, so that the amount of the sound absorbing material used can be reduced, and since the standard sound absorbing material can be used as it is, the processing cost can be reduced, so that the cost can be reduced.

  A space not filled with the sound absorbing mat is formed between the rail abdomen side surface and the upper end of the sound insulating cover, between the rail abdomen side surface and the sound absorbing mat, and between the rail bottom upper surface and the sound insulating cover. More preferably, the amount of the sound absorbing material to be formed is 15% or more of the volume in the sound insulation cover.

  In addition, a bent edge is provided on the peripheral edge of the sound insulation cover, and if the bent edge is covered on the peripheral surface of the sound absorbing mat, sound leakage is prevented and the sound absorbing effect by multiple reflections in the sound insulating cover is provided. Can be further enhanced. In this case, since the rail surface and the bent edge are in perpendicular contact with each other, the gap can be eliminated more reliably.

  In addition, when a sealing member is interposed between the rail surface and the bent edge end, the sound leakage prevention and sound absorbing effects are further enhanced.

  Furthermore, if the sound insulation cover is formed in a flat plate shape that extends from the upper end of the rail abdomen side surface to the top end of the rail bottom, the sound insulation cover has a simple shape, which reduces the processing cost of the sound insulation cover and reduces the cost. Peeled off.

  If the lower edge of the sound insulation cover is positioned above the bottom surface of the rail bottom, it is not necessary to remove the ballast at the bottom of the rail when installing the ballast track, and the construction time can be shortened. Construction is possible even when the clearance between the raceway surfaces is extremely small.

  Moreover, if the sound insulation cover has a vibration damping sheet function, noise due to vibration of the sound insulation cover itself can be suppressed.

  Further, a vibration damping sheet may be interposed between the sound absorbing mat surface and the sound insulating cover back surface.

  The sound absorbing mat is preferably made of at least one of a fibrous sound absorbing material, a resin foam-like sound absorbing material, an open-cell foam sound absorbing material, an inorganic porous sound absorbing material, and an inorganic particle sintered sound absorbing material. In view of the sound absorbing effect and handleability, fibrous sound absorbing materials such as glass wool and rock wool, and resin foam sound absorbing materials such as urethane foam and EPDM foam are more preferable.

  Moreover, it is preferable that a sound-insulation cover consists of at least any one of a metal plate, a resin plate, and an inorganic board. In view of workability, long-term durability, and mechanical strength, it is more preferable to use a corrosion-resistant steel plate such as a galvalume steel plate or a hot dip zinc-aluminum-magnesium alloy plated steel plate.

  In addition, the surface density and thickness of the sound insulation cover are not particularly limited, but sound insulation properties, rigidity that does not break during construction or transportation, workability that can be easily processed without using special tools at the construction site, described below In view of the overlapping sound insulation covers, the surface density is preferably 0.5 to 15 kg / m 2 and the thickness is preferably about 0.1 to 2.0 mm.

  Moreover, it is preferable that the notch for avoiding interference with a rail fastening member is formed in at least any one of the both ends of the lower edge part of a sound-insulation cover. The size and position of the notch are not particularly limited, but the size is preferably 80 to 120 mm in view of the size of the rail fastening member. Further, the rail fastening member may be replaced by one notch in one sound insulating cover, or the rail fastening member may be replaced by combining respective notches in two adjacent sound insulating covers.

  In addition, the length of the sound insulation cover is not particularly limited, but if one sound insulation cover is installed for every sleeper interval, the length of the sound insulation cover will be less than the typical sleeper interval of 550 to 600 mm. Is preferably 600 to 650 mm. Variation in sleeper spacing at the actual construction site is about 50mm, and it is possible to construct without gap by overlapping adjacent covers by setting it to 600-650mm for the site of 550-600mm. . In view of overlapping the sound insulation covers in this way, the thickness of the sound insulation cover is preferably about 0.1 to 2.0 mm as described above.

  In addition, the position where the upper peripheral edge of the sound insulation cover is in contact with the rail surface is not particularly limited as long as it does not reach the construction limit provided in the horizontal direction at a position 38 mm below the rail top surface, but from the rail top surface. A position in contact with the rail surface at a position of 42 to 62 mm on the lower side is preferable.

  Furthermore, the sound insulation cover is fixed to the rail by a fixing tool, and the fixing tool is a combination of the first fixing member and the second fixing member that are in contact with the outer surface of the sound insulating cover. It is preferable that

  According to the present invention, it is possible to effectively provide soundproofing at frequencies in all bands, particularly at frequencies around 1250 Hz that are difficult to soundproof only with the vibration damping sheet.

It is a vertical cross-sectional view of the soundproofing device according to Embodiment 1 of the present invention. It is a vertical cross-sectional view of the soundproofing device according to the second embodiment. It is a side view which shows the installation state of the soundproofing device by the same Embodiment 2. It is sectional drawing which shows the fixing tool of the soundproofing device by the same Embodiment 2. It is a graph which shows the noise reduction effect by the soundproofing device of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1>
The rail R includes a head portion Rt, an abdominal portion Rw, and a bottom portion Rb that are successively connected from the top to the bottom. A pair of left and right soundproofing devices are provided from the left and right side surfaces of the abdominal part Rw to the upper surface of the bottom part Rb. Both soundproofing devices have the same structure, although the left and right directions are different. Hereinafter, the right soundproofing device will be described.

  The soundproofing device according to Embodiment 1 shown in FIG. 1 includes a main vibration damping sheet 11, a sound absorbing mat 12, a sub vibration damping sheet 13, and a sound insulation cover 14 that are layered in order from the inside. Two horizontal belt-like auxiliary damping sheets 15 extend in parallel with each other on the surface of the sound insulation cover 14.

  The main vibration damping sheet 11 is formed to have a substantially cross-sectional L shape so as to expand from the right side of the abdomen Rw of the rail R along the upper surface of the bottom Rb, and includes a vibration damping resin layer 21 and a constraining layer 22. It has a two-layer structure. The back surface side of the damping resin layer 21 is bonded to both surfaces of the rail R using an adhesive. When the damping resin layer 21 is sticky, an adhesive may not be used for bonding the main damping sheet 11. Further, the main vibration damping sheet 11 is not limited to the combination of the vibration damping resin layer 21 and the constraining layer 22 as long as the loss coefficient is 0.1 or more.

  The damping resin layer 21 is a chlorinated polyethylene obtained by post-chlorination of high-density polyethylene by a water suspension method (weight average molecular weight 500,000, chlorine content 40 wt%, crystallinity 10 J / g measured by DSC method). 100 parts by weight, 400 parts by weight of chlorinated paraffin (manufactured by Ajinomoto Fine Chemical Co., trade name “Empara“ K50 ”), chlorine content 50% by weight, number average carbon number 14), calcium carbonate (manufactured by Maruo Calcium Co., trade name) "R heavy coal") 400 parts by weight was kneaded at 120 ° C using a roll kneader, and the resulting resin kneaded product was pressed at 140 ° C to form a sheet having a thickness of 1.0 mm. .

  The constraining layer 22 is made of an aluminum plate having a thickness of 0.7 mm, and is bonded to the damping resin layer 21 using its adhesiveness.

  The sound absorbing mat 12 includes upper and lower divided pieces 31 and 32. Each of the divided pieces 31 and 32 is made of a urethane sound absorbing material (manufactured by Sekisui Urethane Co., Ltd., product name “LBM”, t = 10 mm). The upper divided piece 31 is applied to the vertical surface of the constraining layer 22 so as to correspond to the right side surface of the abdomen Rw of the rail R, and the lower divided piece 32 is formed of the constraining layer 22 so as to correspond to the upper surface of the bottom Rb of the rail R. It is applied to an inclined surface.

  The secondary vibration damping sheet 13 includes upper and lower divided pieces 41 and 42. These divided pieces 41 and 42 are arranged so as to cover the central portions of the two divided pieces 31 and 32 of the sound-absorbing mat 12 with their corresponding edges facing each other. Each of the divided pieces 41 and 42 is composed of a vibration damping resin layer 21 and a constraining layer 22 having the same structure as that of the main vibration damping sheet 11, although the main vibration damping sheet 11 is opposite to the front and back. The side of the damping resin layer 21 is bonded to the back surface of the sound insulation cover 14.

  The entire back surface side of the sound absorbing mat 12 is covered with the main vibration damping sheet 11, but only about 70% of the front surface side is covered with the auxiliary vibration damping sheet 13. For the sound insulation cover 14, the larger the area of the secondary damping sheet 13, the higher the effect of suppressing the noise. However, since the effect reaches a peak at about 70%, about 70% considering the cost effectiveness. Degree is desirable.

  The sound insulation cover 14 is made of a galvanium plated SPC steel plate (thickness 0.35 mm, surface density 2.73 kg / m 2), and includes an abdomen cover portion 51 and a bottom cover portion 52. The abdomen cover part 51 and the bottom cover part 52 are bent and formed in a bent shape so as to form an L shape similar to the L cross section formed by the main vibration damping sheet 11. The length of the sound insulating cover 14 in the rail length direction is 650 mm.

  An upper bent edge 61 is provided on the upper edge of the abdominal cover 51. A pair of upper measuring portion bent edges 62 are provided on both sides of the abdomen cover portion 51. On both sides of the bottom cover portion 52, a pair of bottom measuring portion bent edges 63 are provided. A lower bent edge portion 64 is provided at the lower edge portion of the bottom cover portion 52. These bent edges 61 to 64 cover corresponding portions of the peripheral surfaces of the main vibration damping sheet 11, the sound absorbing mat 12, and the auxiliary vibration damping sheet 13.

  An elastic material having a substantially U-shaped packing 71 is put on the tip of each of the bent edges 61 to 64. These packings 71 are interposed between corresponding portions of the rail surface and the bent edge portions 61 to 64, and serve as a sealing member that prevents sound leakage. Further, instead of the packing 71, sound leakage may be prevented by a caulking material, a tape or the like.

  The auxiliary vibration damping sheet 15 includes a vibration damping resin layer 21 and a constraining layer 22 having the same structure as that of the main vibration damping sheet 11, similarly to the auxiliary vibration damping sheet 13. The side of the damping resin layer 21 is bonded to the surface of the sound insulation cover 14.

  The filling rate of the sound absorbing material in the soundproofing device, that is, the volume occupied by the sound absorbing material with respect to the inner volume of the sound insulating cover 14 is 50%.

  The method for assembling the soundproofing device is as follows. The main damping sheet 11 is affixed to the rail R. The secondary vibration damping sheet 13 is pasted on the back surface of the sound insulation cover 14, and the auxiliary vibration damping sheet 15 is pasted on the surface thereof. The sound absorbing mat 12 is fitted inside the bent edges 61 to 64 of the sound insulating cover 14, and the sound insulating cover 14 is fixed to the rail R so that the sound absorbing mat 12 overlaps the main vibration damping sheet 11. For fixing the sound insulation cover 14, a clamp or an aluminum tape (not shown) may be used.

<Embodiment 2>
The soundproofing device according to Embodiment 2 (the invention according to Claim 1) shown in FIG. 2 is constituted by a sound absorbing mat 111, a vibration damping sheet 112 and a sound insulating cover 113 which are layered in order from the inside.

  The sound absorbing mat 111 is passed from the middle of the rail abdomen Rw side surface height to the center of the rail bottom Rb upper surface in the width direction. The material of the sound-absorbing mat 111 is not the same material as that of the sound-absorbing mat 12 of the first embodiment, but an EPDM foam, “Shirura” manufactured by Toyo Quality One Co., Ltd., and a thickness of 20 mm. In FIG. 2, the sound-absorbing mat 111 is shown as being cut out from the rectangle at the contact portion with the rail R instead of being rectangular in cross section, but this is compressed by being pressed against the rail R. It is formed by being crushed as shown in FIG. Thus, the sound absorbing mat has a rectangular cross section when free, and is obliquely passed from the side surface of the rail abdomen Rw to the top surface of the rail bottom Rb, and the inner upper and lower parts in contact with the rail R are pressed by the rail. It is compressed.

  The vibration damping sheet 112 includes a vibration damping resin layer 121 bonded to the back surface of the sound insulating cover 113 and a constraining layer 122 superimposed on the surface of the sound absorbing mat 111 and bonded to the vibration damping resin layer 121. The material, molding method, and the like of the vibration damping resin layer 121 and the constraining layer 122 are the same as those in the first embodiment.

The sound insulation cover 113 is not formed in a substantially L-shaped cross section as in the case of the first embodiment, but is a rectangular flat plate having a rail bottom from the vicinity of the upper end of the rail abdomen Rw side surface height. Rb is passed near the top of the upper surface. The sound insulation cover 113 is made of the galvanium plated SPC steel plate of the first embodiment, and has a thickness of 0.8 mm and a surface density of 6.24 kg / m ² . The length is 650 mm as in the case of the first embodiment.

  In the second embodiment, as shown in FIG. 2, between the rail abdomen Rw side surface and the sound insulation cover 113 upper end, between the rail abdomen Rw side surface and the sound absorbing mat 111, and between the rail bottom Rb upper surface and the sound insulation cover 11 A space not filled with the sound absorbing mat 111 is formed between them, and the filling rate of the sound absorbing material (the amount of the sound absorbing material forming the sound absorbing mat 111) is 30% of the volume in the sound insulating cover 111. Thus, it is smaller than that in the first embodiment.

  Referring to FIG. 3, an example in which a soundproofing device is installed on a rail R is shown. The sound insulation covers 113 are continuously arranged so that adjacent ones are in contact with each other. On the sleeper M, the rail R is fixed by a fastening member T, and the sound insulation cover 113 is fixed to the rail R by a fixture S. The upper and lower edges of the sound insulation cover 113 are pressed in close contact with the corresponding portions of the rail R. Cutouts 131 are formed at both ends of the lower edge of the sound insulation cover 113, respectively. By this notch 131, interference between the fastening member T and the sound insulation cover 113 can be avoided.

  FIG. 4 shows a specific example of the fixture S. The fixture has a first fixing member 201 and a second fixing member 202. The first fixing member 201 is substantially V-shaped, and is in contact with a portion extending from the outer surface of the left sound insulating cover 113 to the bottom surface of the rail R. The second fixing member 202 has a belt-like shape and is brought into contact with the outer surface of the left sound insulating cover 113. A flat plate-shaped first tightening portion 211 is provided on the right edge portion of the first fixing member 201. A flat plate-like second tightening portion 212 is provided on the right edge portion of the second fixing member 202 so as to overlap the first tightening portion 211. Two first bolt holes are formed in the first tightening portion 211 side by side. Two second bolt holes matched with the first bolt holes are formed in the second tightened portion 212. The threaded portion of the tightening bolt 241 is passed through the first bolt hole and the second bolt hole from the lower side of the first bolt hole. A detent 244 for restricting the rotation of the head of the tightening bolt 241 is provided on the lower surface of the peripheral edge of the first bolt hole. The rotation stopper 244 is a drooping plate-like shape, and is located at a position where a slight gap is provided on the outer peripheral flat surface of the head of the tightening bolt 241. A nut 245 is screwed into a portion of the screw portion that protrudes upward from the second bolt hole.

  If the threaded portion of the tightening bolt 241 is passed through the first bolt hole and the second bolt hole and the outer peripheral flat surface of the head of the tightening bolt 241 is made to face the rotation stopper 244, the tightening bolt 241 cannot rotate. Therefore, it is only necessary to rotate only the nut 245 and tighten the first tightened portion 211 and the second tightening portion with the tightening bolt 241 and the nut 245.

  A soundproof test was performed using the soundproofing device having the above-described configuration. The sleeper span 600mm, 50N rail R is vibrated by outputting pink noise with a vibration speaker. In order to prevent the influence of the direct sound from the vibration speaker, a microphone was placed at a location 100 mm from the abdomen Rw of the rail R at a location 2 m away from the excitation point, and the noise level was measured.

  As a comparative example, a soundproofing device using only the damping sheet corresponding to the main damping sheet 11 of the present application described in the section of the prior art at the beginning was also measured. For the soundproofing device of the first embodiment of the present invention and the soundproofing device of the second embodiment of the present invention (the invention according to claim 1) from the case of measuring the unmeasured rail that has not taken any soundproofing measures, the amount of noise level reduction is as follows. It was measured.

  The measurement results are shown in FIG. As apparent from FIG. 5, it can be seen that the noise level reduction amount is larger in almost the entire frequency range according to the soundproofing devices of Examples 1 and 2 than in the soundproofing device of the comparative example. In particular, the reduction effect is remarkable in the region of 1000 to 1250 Hz.

  In the first embodiment, an example in which a vibration damping sheet is attached to the rail surface is shown, but this vibration damping sheet may be omitted.

  Further, although an example is shown in which vibration damping sheets are attached to both the front and back surfaces of the sound insulation cover, the vibration damping sheets may be provided only on either of the front and back surfaces of the sound insulation cover. Furthermore, the sound insulation cover itself may be formed of a vibration damping sheet.

111 Sound absorbing mat
112 Vibration control sheet
113 Sound insulation cover R rail
Rw rail abdomen
Rb rail bottom

Claims (5)

  The required part of the rail surface is covered with a sound absorbing mat and a sound insulation cover inside and outside, and the sound absorbing mat has a rectangular cross section when free, and is passed diagonally from the rail abdomen side to the rail bottom top, A rail soundproofing device characterized in that the upper and lower portions of the inner surface in contact with the rail are compressed by being pressed by the rail.   The sound insulation device for a rail according to claim 1, wherein the sound insulation cover has a flat plate portion whose upper end portion is positioned at the upper end portion on the side surface of the rail abdomen and is extended to the front end portion of the upper surface of the rail bottom portion.   The rail soundproofing device according to claim 1 or 2, wherein a vibration damping sheet is interposed between the surface of the sound absorbing mat and the back surface of the sound insulating cover.   A space not filled with the sound absorbing mat is formed between the rail abdomen side surface and the upper end of the sound insulating cover, between the rail abdomen side surface and the sound absorbing mat, and between the rail bottom upper surface and the sound insulating cover. The rail soundproofing device according to any one of claims 1 to 3, wherein the amount of the sound absorbing material to be formed is 15% or more of the volume in the sound insulating cover.   The sound insulation cover is fixed to the rail by a fixing tool, and the fixing tool is a combination of a first fixing member and a second fixing member that are brought into contact with the outer surface of the sound insulation cover. The soundproofing device for rails according to any one of claims 1 to 4.

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