JP2009007768A - Track pad - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a track pad which does not adhere to the lower surface of a rail even after a long-term use. <P>SOLUTION: The track pad 10 is formed of an elastic member and has an upper surface 12 facing the rail, and a lower surface 14 facing sleepers. The upper surface 12 has a plurality of projective surfaces 16, 18 and 20 which are tapered from a lower portion to an upper portion. The projective surface is engaged with the lower surface of the rail to support the rail, and upon the application of a load to the rail, the surface is compressively deformed to increase an engaged area engaged with the lower surface of the rail. On the other hand, when the load is removed, the compressively deformed surface is restored to decrease the engaged area engaged with the lower surface of the rail. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a track pad that is set between a railroad sleeper (or a tie plate fixed on the sleeper) and a rail, and in particular, a track that does not adhere to the rail even after long-term use. Related to pads.

  The track pad is a rubber-made rectangular pad set between the sleeper and the rail mainly for the purpose of cushioning, and has an upper surface on which the lower surface of the rail is placed and a lower surface that is placed on the sleeper.

A conventional track pad may be provided with grooves on the upper and lower surfaces to adjust the spring constant of the track pad, but the track pad is generally flat. (See Patent Document 1)
Patent Publication 11-124804

  In track maintenance work, the rails are removed from the sleepers and replaced with new rails. Normally, all the track pads laid under the rails are under the old rails removed from the sleepers. Will remain attached. The track maintenance work needs to be done at a limited time such as at night, so a quick work is required. Until now, however, it has been extremely difficult for an operator to remove the track pad one by one using a scoop or a tool. The work was inefficient.

  In view of these points, the present invention is intended to provide a track pad that does not adhere to the rail, and to improve the efficiency of rail replacement work.

That is, the present invention
A track pad formed of an elastic member having an upper surface facing the rail side and a lower surface facing the sleeper side,
The upper surface has a plurality of convex surfaces shaped so as to taper from the bottom toward the top,
The convex surface engages with the lower surface of the rail to support the rail, and when a load is applied to the rail, the convex surface compresses and deforms, and the engagement area with the rail lower surface increases. The track pad is characterized in that when the load is removed, the convex surface is restored and the engagement area with the lower surface of the rail is reduced.

  In the conventional track pad, since the top surface of the track pad is a flat surface as a whole even when a groove for adjusting the spring constant of the track pad is provided as described above, Even if a load is applied through the rail as the vehicle passes through the rail, the upper surface of the track pad and the lower surface of the rail are always in contact with each other on the same surface (area). It is thought that adhesion of the pad to the rail occurs. On the other hand, in the track pad according to the present invention, as described above, when a load is applied to the rail, the convex surface is compressed and deformed, and the engagement area with the lower surface of the rail is increased. When the load is removed, the convex surface is restored and the area with the lower surface of the rail is reduced. That is, when the vehicle passes and a load is applied to the rail, the convex surface provided on the upper surface of the rail track compresses and deforms, but when the vehicle passes and the load disappears, the elasticity of the track pad is reduced. It is restored by the elastic force of the member, and the contact surface of the upper surface of the track pad with the rail lower surface changes. This makes it difficult for the track pad to adhere to the lower surface of the rail. Further, even if adhesion occurs, the contact area is small, and therefore, the peeling operation from the rail becomes easy.

  Specifically, the convex surface can be a semi-cylindrical shape extending along the upper surface of the track pad.

  In another example, the convex surface can be spherical.

  These shapes can withstand long-term use.

  More specifically, the convex surface may include a plurality of convex surfaces that are spherical and a plurality of convex surfaces that are cylindrical.

  A plurality of convex surfaces that contact the lower surface of the rail when the rail is placed on the track pad; and a plurality of convex surfaces that are lower than the first convex surface. It can also be made to have.

  In this way, in the second convex surface, the compressive force applied by the rail is smaller than that in the first convex surface, and fatigue due to compression is small, so that the restoring force is less susceptible to secular change. It is possible to maintain the restoring force of the track pad after passing the vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a first embodiment of a track pad according to the present invention.

  The track pad 10 is formed of an elastic member such as rubber and has an upper surface 12 facing the rail side and a lower surface 14 facing the sleeper side.

  A semi-cylindrical first convex surface 20 having a large curvature radius and a semi-cylindrical second convex surface 18 having a small curvature radius are alternately provided in parallel on the upper surface 12 over the entire surface. A spherical third convex surface 16 is provided along the ridge line of the first convex surface 20.

  The heights from the lower surface 14 to the vertices of the first and second convex surfaces are t1 and t, respectively, and the heights to the vertices of the third convex surface are t2. On the lower surface 14, a groove 22 for adjusting the spring constant of the track pad is provided at a position corresponding to each first convex surface so as to extend in parallel with the first convex surface 20. .

  When the rail is fastened to the sleepers, first, the rail is placed on the track pad so that the lower surface thereof is in contact with the third convex surface 16. When the fastening is completed, a downward fastening force is applied to the rail and applied to the track pad through the lower surface of the rail.

  As a result, the track pad is compressed and deformed, and the degree thereof is appropriately determined as necessary. That is, at the time of fastening, the lower surface of the rail only compresses the third convex surface 16 to some extent and does not come into contact with other convex surfaces, or the degree of compression is increased so that the lower surface of the rail is third. In addition, the second convex surfaces 16 and 18 can be compressed, or the lower surface of the rail can compress all the first to third convex surfaces. In this case, the gap 24 formed between the convex surfaces is always maintained, and even when the vehicle passes, the lower surface of the rail may come into contact with the entire upper surface of the track pad. The gap is retained.

  FIG. 2 shows another embodiment of the track pad according to the present invention.

  That is, in the track pad 30, the first to third projections corresponding to the first, second, and third projection surfaces in the track pad 10 according to the first embodiment described above are respectively obtained at the height of the apex. All of the shaped surfaces 40, 38, and 36 are spherical, and are arranged at predetermined intervals on the upper surface of the track pad.

  FIG. 3 shows yet another embodiment of a track pad according to the present invention. In the track pad 50, first to third convex surfaces 70, 68, 66 corresponding to the first to third convex surfaces of the track pad according to the first embodiment are provided at the height of the apex. It has been. The second convex surface 68 is an elongated surface having a rectangular cross section extending in the rail setting direction on the upper surface of the track pad 50, and the first convex surface 70 is the second convex surface 68. It is a substantially semi-cylindrical surface provided at a predetermined interval in the length direction, and the third convex surface 66 is a spherical surface provided at a substantially central position of the first convex surface 70. It is said that.

  FIG. 4 shows another embodiment of a track pad according to the present invention. In this track pad 80, first to third convex surfaces 90, 88, 86 corresponding to the first to third convex surfaces in the track pad according to the first embodiment are provided at the height of the apex. It has been. The second convex surface 88 is a semi-cylindrical surface extending in the rail setting direction on the upper surface of the track pad 50, and the third convex surface 86 is a cross section extending in parallel with the second convex surface. Is a triangular elongated surface, and the first convex surface 90 has a triangular cross section extending along both sides of the third convex surface 86.

  A 50c type track pad (width W is 125 mm, length L is 180 mm, thickness is 6 mm) formed using rubber of the second kind material standardized as JIS-E1117, width W and length L are The same structure as described above with t, t1, and t2 set to 6 mm, 6.3 mm, and 7.5 mm, respectively, and a compression deformation test (load condition: 50 kN; 300 kN) and a fatigue test (load condition 15 ± 10 kN; 100,000 times) were performed, and at that time, it was determined whether or not the track pad adhered to the lower surface of the rail.

  As a result, it was found that the track pad according to the present invention satisfies the standards for both the compression deformation test and the fatigue test, and in any case, no adhesion to the rail was observed.

  In contrast, the conventional 50C type track pad was attached to the rail in any case.

It is the top view and front view of 1st Embodiment of the track pad which concern on this invention. It is the top view and front view of 2nd Embodiment of the track pad which concern on this invention. It is the top view and front view of 3rd Embodiment of the track pad which concern on this invention. It is the top view and front view of 4th Embodiment of the track pad which concern on this invention.

Explanation of symbols

10, 30, 50, 80 Trajectory pads 16, 36, 66, 86 Third convex surfaces 20, 40, 70, 90 First convex surfaces 18, 38, 68, 88 Second convex surfaces

Claims (5)

A track pad formed of an elastic member having an upper surface facing the rail side and a lower surface facing the sleeper side,
The upper surface has a plurality of convex surfaces shaped so as to taper from the bottom toward the top,
The convex surface engages with the lower surface of the rail to support the rail, and when a load is applied to the rail, the convex surface compresses and deforms, and the engagement area with the rail lower surface increases. The track pad is characterized in that when the load is removed, the convex surface is restored and the engagement area with the lower surface of the rail is reduced.   2. The track pad according to claim 1, wherein the convex surface has a semi-cylindrical shape extending along the upper surface.   The track pad according to claim 1, wherein the convex surface is spherical.   The track pad according to claim 1, wherein the convex surface includes a plurality of convex surfaces that are spherical and a plurality of second convex surfaces that are semi-cylindrical extending along the top surface.   The convex surface includes a plurality of convex surfaces that contact a lower surface of the rail when the rail is placed on the track pad, and a plurality of convex surfaces that are lower than the convex surface. The orbital pad in any one of thru | or 4.

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