JPH027921Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the shape of tie plates used when installing rails on wooden sleepers.

In recent years, railway vehicles have become heavier and faster, and as a result, structural and material strength requirements have become stricter for each member that makes up the tracks. Especially for steelworks railways, the axle load is 40 to 50 TON.
The strength requirements for the track material are especially severe. Wooden sleepers used as track materials also require hard and tough materials.
Due to the depletion of wood resources, materials that meet these demands are decreasing in quantity and becoming more expensive. Damage to wooden sleepers under such severe external force conditions can be broadly classified into (1) natural damage and (2) mechanical damage.

Natural damage is mainly caused by corrosion of railroad ties, which can be countered by antiseptic treatment of railroad ties and improvement of drainage conditions of roadbeds. Regarding mechanical damage, (a) penetration of tie plates into wooden sleepers, (b) enlargement of nail holes such as dog nail holes or screw spike holes in wooden sleepers, (c) splitting of wooden sleepers, (d)
Although it is possible that the wooden sleepers were broken, the damage contribution ratio of (a) and (b) above is large. The present invention deals with damage (a).

The cause of the tie plate digging into the wooden sleeper is
This is because the stiffness of the tie plate is high, so even when a vertical load is applied, the bearing pressure distribution on the sleeper surface is not uniform, and especially when a lateral load is applied, the bearing pressure distribution becomes largely unbalanced. Figures 1 and 2 show the shape of the bearing pressure distribution under the highly rigid tie plate. As shown in FIG. 1, when the rigidity of the tie plate 1 is high, a considerably large bearing pressure is generated at the end of the tie plate, which causes the wooden sleeper 3 to become wedged and damage the sleeper. Furthermore, as shown in Fig. 2, if the thickness of the tie plate 2 is reduced to reduce its rigidity, bending failure of the tie plate and shear failure from the nail holes will occur, which will result in uniform bearing pressure distribution. There's a problem.

One possible measure to make the bearing pressure distribution uniform is to place a rubber pad under the tie plate, but this idea also leads to the destruction of the rubber pad and is not a fundamental solution.

The purpose of the present invention is to provide a tie plate that solves the above-mentioned problems and extends the life of wooden sleepers. This tie plate for wooden sleepers is characterized in that a curved bottom surface is formed that curves upward smoothly from the middle side of the tie plate toward the end edge.

The present invention will be explained in detail below using the drawings.

In the case of the first embodiment shown in FIG. 3, both ends of the steel tie plate 4 for wooden sleepers parallel to the rail running direction are smoothly curved upward, and a tie plate intermediate portion is provided at both ends of the tie plate 4. A curved bottom surface 6 is formed that curves upward smoothly from the side toward the edge, and both ends of the tie plate 4 gradually become thinner from the middle side toward the edge. In the case of the first embodiment, the bearing pressure distribution is maximum at the center, and gradually decreases from the center toward both ends of the contact portion with the wooden sleeper 3, and becomes zero at both ends, so that both ends of the tie plate 4 are connected to the wooden sleeper 3. Don't get stuck in 3.

In the case of the second embodiment shown in FIG. 4, curved bottom surfaces 6 are formed at both ends of the steel tie plate 5 for wooden sleepers parallel to the rail running direction, and curve upward smoothly from the middle side of the tie plate toward the edge. are formed by cutting or other means, and both ends of the tie plate 5 gradually become thinner from the middle side toward the edges. In the case of the second embodiment, as in the case of the first embodiment, the bearing stress at the end of the tie plate is small, and the end of the tie plate does not bite into the wooden sleeper 3.

Since the present invention is constructed as described above, it is possible to prevent the two edges of the tie plate for wooden sleepers parallel to the rail running direction from being wedged into the wooden sleepers 3 by a simple means. This has the effect of greatly extending the lifespan of the engine, reducing maintenance costs and saving resources.

[Brief explanation of drawings]

Figure 1 is a front view showing the bearing pressure distribution shape under the tie plate when a tie plate with high rigidity is used, and Figure 2 is a front view showing the bearing pressure distribution shape under the tie plate when a tie plate with low rigidity is used. FIG. Figure 3 is a front view showing the tie plate and bearing pressure distribution shape of the first embodiment of the present invention;
The figure is a front view showing the tie plate and bearing pressure distribution shape of the second embodiment of the present invention. In the figure, 1 is a tie plate with high rigidity;
2 is a tie plate with low rigidity, 3 is a wooden sleeper, and 4 is a tie plate with low rigidity.
5 is a tie plate with smoothly bent edges, 5 is a tie plate with both edges thin and smooth, 6 is a tie plate with smooth edges.
is a curved bottom surface.

Claims (1)

[Scope of utility model registration request] This tie plate for wooden sleepers is characterized in that a curved bottom surface 6 that curves upward smoothly from the middle side of the tie plate toward the edge is formed at both ends parallel to the rail running direction of the tie plate for wooden sleepers.