Abstract:
A train rail includes an upper rail head, a lower rail head, a web, and at least one piezoelectric plate. The lower rail head is substantially parallel to the upper rail head. The web perpendicularly connects the upper rail head to the lower rail head. The at least one piezoelectric plate is positioned in the train rail and configured for producing electric power under pressure.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to a rail used for train tracks and train tracks having the same. 
         [0003]    2. Description of Related Art 
         [0004]    Train tracks usually consist of pairs of rails connected end to end. Many modern trains are powered by electricity supplied by overhead wires or additional rails and are guided by many electronic devices along the tracks, such as indicator lights all adding up to tremendous amount of electricity being used. 
         [0005]    Therefore, it is desirable to provide a train rail and train tracks having the same, which can overcome or at least alleviate the above-mentioned problems. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is an isometric view of a train track including two train rails, according to a first exemplary embodiment. 
           [0007]      FIG. 2  is a sectional view of one rail of  FIG. 1 . 
           [0008]      FIG. 3  is a sectional view of another rail, according to a second exemplary embodiment. 
           [0009]      FIG. 4  is a sectional view of yet another rail, according to a third exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Referring to  FIG. 1 , a train track  100 , according to a first exemplary embodiment, includes two train rails  10  and a number of ties  20 . The two train rails  10  are laterally spaced apart one from the other by a distance sufficient to establish the desired gauge of the train track  100 . The ties  20  are parallel to each other and arranged between the two train rails  10 . Each tie  20  is perpendicular to the two train rails  10 . 
         [0011]    Referring to  FIG. 2 , the train rails  10  are approximately I-shaped in cross-section. Each train rail  10  includes an upper rail head  12 , a lower rail head  14 , a web  16  connecting the upper rail head  12  to the lower rail head  16 , a first piezoelectric plate  17 , and a second piezoelectric plate  18 . 
         [0012]    The upper rail head  12  has an upper curved surface  120  to engage with the wheels of a train (not shown) and defines a first receiving groove  122 . The first receiving groove  122  is arranged within the upper rail head  12  and the length direction of the first receiving groove  122  coincides with the length direction of the train rail  10 . The first piezoelectric plate  17  is received in the first receiving groove  122 . The depth of the first piezoelectric plate  17  is less than half of the depth of the upper rail head  12 . 
         [0013]    The lower rail head  14  is substantially parallel to the upper rail head  12 . The lower rail head  14  defines a second receiving groove  142 . The second receiving groove  142  is arranged within the upper rail head  12  and the length direction of the second receiving groove  142  coincides with the length direction of the train rail  10 . The second piezoelectric plate  18  is received in the second receiving groove  142 . The depth of the second piezoelectric plate  18  is less than half of the depth of the lower rail head  14 . 
         [0014]    Wires (not shown) connected to the first piezoelectric plate  17  and the second piezoelectric plate  18  extend through the train rails  10  to connect electronic devices or a storage battery on the train track  100 . Each of the first piezoelectric plate  17  and the piezoelectric plate  18  is made of piezoelectric material, such as organic piezoelectric material, inorganic piezoelectric material, or compound piezoelectric material. In this embodiment, the organic piezoelectric material may be polyvinylidene fluoride. The inorganic piezoelectric material may be piezotransistor or piezoceramics. The piezotransistor includes quartz crystal, lithium gallium oxide, lithium germinate, lithium niobate and lithium tantalite. The piezoceramics includes barium titanate, barium zirconate titanate, modified barium zirconate titanate, and modified lead titanate. The compound piezoelectric material includes a polymer base, organic piezoelectric material and inorganic piezoelectric material. The organic piezoelectric material and the inorganic piezoelectric material are embedded in the polymer base. 
         [0015]    Pressure on the train rails  10  from passing trains will be applied to the first piezoelectric plate  17  and the piezoelectric plate  18 . Then, the two piezoelectric plates  17  and  18  transform the mechanical energy to electric energy. The two piezoelectric plates  17  and  18  will transmit the electric power to the electronic devices and/or the storage battery on the train track  100 . Thus, the pressure of the trains can provide additional electric energy for charging the battery and/or powering the electronic devices on the train track  100 , achieving good energy conservation. 
         [0016]    Referring to  FIGS. 2-3 , a train rail  30 , according to a second exemplary embodiment, is shown. The differences between the train rail  30  of this embodiment and the train rail  10  of the first embodiment are: the first and second receiving grooves are omitted, and two piezoelectric plates  32  are arranged at opposite sides of the web  36  perpendicular to the upper and lower rail heads. 
         [0017]    Referring to  FIGS. 2-4 , a train rail  40 , according to a third exemplary embodiment, is shown. The differences between the train rail  40  of this embodiment and the train rail  10  of the first embodiment are: the first receiving groove is omitted, the second receiving groove  442  is exposed at the lower rail head  44 , and the second piezoelectric plate  48  is received in the second receiving groove  442  and is exposed at the lower rail head  44 . 
         [0018]    The advantages of the second and third embodiments are similar to those of the first embodiment. 
         [0019]    It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set fourth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in details, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.