Abstract:
A device for holding a transmitter and a receiver for detecting a deformation state of a component. The device includes a first holding part and a first receptacle, the transmitter being disposed on the first holding part via the first receptacle, wherein the first receptacle and the first holding part, together with the component, form at least one of a first connecting element, a first clamp, a first positive fit joint, a first glued joint, and a first welded joint. The device also includes a second holding part and a second receptacle, the receiver being disposed on the second holding part using the via receptacle, wherein the second receptacle and the second holding part, together with the component, form at least one of a second connecting element, a second clamp, a second positive fit joint, a second glued joint, and a second welded joint.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
   This application is a U.S. National Stage Application under 35 U.S.C. §371 of PCT International Application No. PCT/EP02/11596, filed Oct. 17, 2002, which claims priority to German Patent Application DE 101 52 380.7, filed Oct. 28, 2001. Each of these applications is incorporated herein by reference as if set forth in its entirety. 
   The invention relates to a device for a transmitter and for a receiver for detecting various deformation states of a component that, independently of each other, are arranged on the component at a distance from each other by means of a receptacle. 
   A deformation sensor is already known from international application WO 01/18487 A1 in which a transmitter and a receiver for measuring deformation states are arranged together on a plate. Here, the plate is attached to a component by means of at least one clamping element, whereby the clamping element has two pointed or round contact parts and at least one bore corresponding to the plate. 
   An object of the invention is to provide for configuring and arranging a holding device for a transmitter-receiver unit in such a way that simple and precise assembly is ensured. 
   The present invention provides a device for a transmitter ( 2 ) and a receiver ( 3 ) for detecting various deformation states of a component ( 1 ) that, independently of each other, are arranged on the component ( 1 ) at a distance from each other by means of a receptacle ( 20 ,  30 ). The transmitter is arranged on a first holding part by means of a first receptacle and the receiver is arranged on a second holding part by means of a second receptacle, whereby, together with the component, each receptacle and each holding part form one or more connecting elements or one or more clamped and positive-fit joints or a glued joint or a welded joint. In this manner, the transmitter and the receiver are arranged on the component independently of each other, whereby the receptacle serves simultaneously as part of the clamped joint for the transmitter and the receiver. By integrating the receptacle into the clamping device, during the clamping procedure, the receptacle is deformed, thus causing an adjustment of the transmitter or the receiver. The independence of the transmitter and receiver receptacle or holding part ensures that the component absorbs the deformation in a manner that is free of influences. Neither the transmitter nor the receiver absorb a force that is generated by the deformation of the component. 
   For this purpose, it is also advantageous for the receptacle and the holding part to have a corresponding fit, whereby this fit is configured as a groove-and-tongue joint and/or as a location pin. Thanks to the fit, the assembly effort or the adjustment effort of the receptacle on the holding part is reduced to a minimum. 
   Moreover, it is advantageous for the receptacle to be configured as a lug and to be connected to the holding part by means of a pin joint and/or a bolted joint, whereby the receptacle and/or the holding part has a clamping element that is configured as a bolt, a screw and/or a cam and that interacts with the component. Through the use of an additional clamping element, the receptacle can be attached to the holding part independently of the clamped joint. By means of the independent clamping element, the receptacle can be moved together with the holding part relative to the component, without the connection between the receptacle and the holding part having to be severed. 
   It is of special significance for the present invention for the receptacle to have a holding element for the transmitter and/or the receiver, whereby the holding element is configured as a bore and has a fastening element configured as a cap nut for the transmitter and/or the receiver. The configuration as a precision bore ensures an optimal protection for the transmitter or the receiver which, if the bore is sufficiently long, can be inserted into the bore and sunk there. 
   It is also advantageous for the first receptacle for the transmitter and the second receptacle for the receiver to have at least one corresponding adjustment surface that can be joined using an assembly device, whereby the adjustment surface is configured as a groove, a bore and/or a bevel and the assembly device has adjustment elements such as a tongue or a pin that correspond to the adjustment surface. In this manner, a transmitter receptacle and a receiver receptacle can be aligned relative to each other in a simple manner. The assembly device can be used for any receptacles and does not have to stay on the device. 
   Moreover, it is advantageous for there to be several receptacles within a measuring area of the component, whereby the receivers are in operative connection via an evaluation unit. 
   An additional possibility according to another embodiment is for there to be several transmitter-receiver pairs arranged on opposite sides of the component. When the device is used for measuring rail systems, the transmitter and the receiver are positioned on opposite sides of the rail, that is to say, on the right-hand and left-hand sides of the rail relative to the longitudinal axis of the rail, and they extend along a rail section between 3 m and 30 m that is to be measured. 
   Finally, it is advantageous for a measuring current generated by the receiver to be transformed into a measuring voltage inside the evaluation unit, and the angular change between the transmitter and the receiver upon which the voltage change is based is determined according to the following formula: 
                 U   1     -     U   2           U   1     +     U   2         =     Δ   ⁢           ⁢     α   1             
In this context, it is advantageous for the load forces F Q , F Y  upon which the deformation of the component is based to be determined at a right angle to the longitudinal direction of the component according to the following formula:
 
                   F   Q     =         Δ   ⁢           ⁢     α   1       +     Δ   ⁢           ⁢     α   2         2                   F   Y     =         Δ   ⁢           ⁢     α   1       -     Δ   ⁢           ⁢     α   2             Δ   ⁢           ⁢     α   1       +     Δ   ⁢           ⁢     α   2                       
wherein F Q  stands for the force in the direction of the vertical and F Y  stands for the force running at a right angle thereto, and α 1 , α 2  stand for the angular change of at least two different transmitter-receiver pairs that are arranged on one side of and/or opposite to the component relative to the Y-direction.
 
   For this purpose, it is also advantageous for the deformation ΔX of the component to be proportional to the detected angular change Δα and for it to be detected as a function of the component length L, whereby the surface area of a deformation graph “X over L” determined in this manner is normalized through a mean value formation ΔX′ of all of the deformation graphs upon which one load cycle is based, and the ratio of the deformation ΔX to the normalized deformation ΔX′ is calculated. For the normalization, all of the deformation graphs corresponding to a normal load are averaged. The graphs diverging from a normal deformation are not taken into account since these distort the overall result of the mean load graph. Thus, all variables such as temperature, rail bed condition, material condition and basic load of the component are eliminated so as to ensure that the deformation of the component is represented so as to correspond to the basic load. 
   Finally, it is advantageous for the connecting element to consist of the holding part that can be placed underneath the rail foot and of a receiving part arranged thereupon so as to be height-adjustable and made up of two legs, whereby at least two screws can be screwed into the one leg, whereby the one screw can be placed against the component or the rail foot, and the other screw part creates a fixed connection between the holding part and the component or the rail, whereby the second leg can be pressed against the holding part by means of at least one screw. 

   
     Additional advantages and details of the invention are explained in the patent claims and in the description and they are depicted in the figures. The following is shown: 
       FIG. 1   a  a schematic representation of a rail with a transmitter and a receiver; 
       FIG. 1   b  a schematic representation of the rail with a transmitter-receiver unit; 
       FIG. 1   c  a schematic representation of two transmission units arranged opposite to each other relative to a longitudinal direction of the rail. 
       FIG. 2  a schematic representation of a cross section of the rail with a receptacle and a holding part; 
       FIG. 3  a schematic representation of the rail with the receptacle and an assembly device; 
       FIG. 4   a  a schematic representation of the rail with the transmitter, the receiver and a measuring beam; 
       FIG. 4   b  a schematic representation of the transmitter and of the receiver with a neutral measuring beam; 
       FIG. 4   c  a schematic representation of the transmitter and of the receiver with a deflected measuring beam; 
       FIG. 4   d  a schematic representation of the transmitter and of the receiver in a side view with a deflected measuring beam; 
       FIG. 5  the receiver with a current tap and part of the evaluation unit; 
       FIG. 6  a schematic representation of the rail in a cross section with receivers arranged opposite and with a deflected measuring beam; 
       FIG. 7  a measuring graph of two wheels depicting approaching and leaving; 
       FIG. 8  a schematic representation of a rail bed with several transmitter-receiver units and two detection switch pairs; 
       FIG. 9   a   1  a measuring graph of a bending line between two railroad ties over the time t; 
       FIG. 9   a   2  a measuring graph of a bending line between two railroad ties over the path s; 
       FIG. 9   b   1  a measuring graph of a bending line between two railroad ties over the path s with a flat section; 
       FIG. 9   b   2  a correction graph for a bending line between two railroad ties over the path s; 
       FIG. 9   c   1  a correction graph for several sensing points over the path s; 
       FIG. 9   c   2  a measuring graph of several sensing points over the path s; 
       FIG. 9   d  a representation of the relationship between the measuring graph and the correction graph over the path s; 
       FIG. 9   e   1  a representation of a plotting of the wheel through a load plateau; 
       FIG. 9   e   2  a representation of a polygon of the wheel through a load diagram; 
       FIG. 9   e   3  a representation of an out-of-roundness of the wheel through a load diagram; 
       FIG. 9   e   4  a representation of a flat section of the wheel through a load diagram. 
   

   DETAILED DESCRIPTION 
     FIG. 1   a  shows a side view of a railroad rail  70  with a rail head  71  and a rail foot  72 . A load force F of a wheel  73  of a passenger or freight train (not shown here) acts upon the rail  70 . Here, the force F is introduced into the rail at the point P. Through the points P 1  and P 2  or the railroad ties  75 ,  75 ′, the force F is dissipated in the form of a surface compression into the substrate or into the rail bed, shown in an idealized manner. Due to the load F, a deformation of the rail  70  and of the elastic rail bed occurs which is picked up by means of a transmitter  2  and a receiver  3 . 
   Here, the transmitter  2  or the receiver  3  is provided in a first receptacle  20  or in a second receptacle  30 , respectively, that are arranged on the rail foot  72  of the rail  70  by means of a first holding part  21  or by means of a second holding part  31 . Here, the first receptacle  20  or the second receptacle  30  will follow the deformation of the rail  70  or the deformation of the rail foot  72  caused by the load F and will thus pick up the deformation cycle. In order to pick up the deformation cycle, no force is transmitted between the transmitter  2  or the first receptacle  20  and the receiver  3  or the second receptacle  30 , so that the deformation cycle is determined in a manner that is loss-free or influence-free. 
   According to  FIG. 1   b , a uniform transmitter-receiver unit  32  is arranged in the area of the rail foot  72 . Here, the transmitter-receiver unit  32  can be configured as a resistance strain gauge and/or as a waveguide that is arranged in the longitudinal direction of the rail. 
     FIG. 1   c  shows two transmitter-receiver units  32 ,  32 ′ arranged opposite from each other relative to the longitudinal direction of the rail  70 . The attachment is once again on the appertaining rail foot  72  or  72 ′. The appertaining transmitter-receiver unit  32  is provided over the entire length between the railroad tie  75  and the railroad tie  75 ′. 
   In  FIG. 2 , the first receptacle  20  for the transmitter  2  or for the receiver  3  is arranged on the rail foot  72  of the rail  70 . For this purpose, the first receptacle  20  has a screwed joint  22  with a first holding part  21 . In addition to the screwed joint  22 , the first receptacle  20  with the first holding part  21  has a fit  40  consisting of a tongue  42  of the first receptacle  20  and a groove  41  of the first holding part  21 . The screwed joint  22  presses the tongue  42  into the groove  41  so that a positive-fit joint is ensured between the first receptacle  20  and the first holding part  21 . 
   The first receptacle  20  is configured so as to be essentially L-shaped and it has a first leg  20 . 1  and a second leg  20 . 2 . Between the second leg  20 . 2  and the first holding part  21 , the fit  40  is provided with the tongue  42  and the groove  41 . The tongue  42  is arranged on the second leg  20 . 2  of the first receptacle  20  and the groove  41  is arranged on the first holding part  21 . Thanks to the fit  40 , in addition to the screwed joint  22 , a positive-fit joint is ensured between the first receptacle  20  and the first holding part  21 . 
   The connecting element can consist of the holding part that can be placed underneath the rail foot and of a receiving part made up of two legs and arranged thereupon so as to be height-adjustable, whereby at least two screws can be screwed into the one leg, whereby the one screw can be placed against the component or the rail foot, and the other screw part creates a fixed connection between the holding part and the component or the rail, whereby the second leg can be pressed against the holding part by means of at least one screw. 
   The first leg  20 . 1  of the first receptacle  20  has a holding element  24  configured as a bore that serves to receive the transmitter  2  or the receiver  3 . In order to secure the transmitter  2  or the receiver  3 , there is a fastening element that may be configured as a cap screw  25  and/or as a cap nut that is arranged on the front of the transmitter or of the receiver. The screwed joint  22  passes through the first leg  20 . 1  and engages a thread  21 . 1  of the first holding part  21 . 
   In addition to the screwed joint  22  and the fit  40 , there is a clamping element  23  that is connected to the rail foot  72  by means of a thread  23 . 1 . Consequently, the clamping element  23 , which is configured as a screw, braces the first receptacle  20  against the rail foot  72  by means of the first holding part  21 . The fit  40  ensures a clear-cut positioning of the second leg  20 . 2  relative to the first holding part  21 . Due to the pretensioning force of the clamping element  23 , a bending force is introduced into the second leg  20 . 2  that leads to a deformation and thus to an adjustment of the holding element  24  for the transmitter  2  and/or the receiver  3 . 
   On the opposite side of the rail  70 , the first holding part  21  has a second groove  41 ′ that serves to secure another receptacle (not shown here). 
   According to  FIG. 3 , the first receptacle  20  and the first holding part  21  are provided in the area of the rail foot  72 . In addition to the first holding part  21 , there is a second holding part  31  that serves to receive the second receptacle  30  for the receiver  3 . There is an assembly device  51  for assembling the first receptacle  20  or the second receptacle  30 . The assembly device  51  has adjustment elements  52 ,  52 ′ that can be joined to an adjustment surface  50  of the first holding part  21  and to an adjustment surface  50 ′ of the second holding part  31 . The adjustment elements  52 ,  52 ′ are configured so as to be pin-shaped and they engage the adjustment surfaces  50  and  50 ′ that are configured as bores. 
   According to  FIG. 3 , the adjustment surface  50  and the adjustment surface  50 ′ are provided on the bottom of the first holding part  21  and of the second holding part  31 , respectively. It is also possible to arrange the adjustment surfaces  50 ,  50 ′ on another side surface of the receptacle  20  and/or of the holding part  21 . 
   The schematic representation according to  FIG. 4   a  shows a rail  70  with the two railroad ties  75 ,  75 ′as well as a transmitter  2  and a receiver  3 . The transmitter  2  and the receiver  3  are arranged on the rail  70  by means of a first receptacle  20  or a second receptacle  30 . When the rail is not yet loaded (i.e. F=0), the measuring beam  4  emitted by the transmitter  2  strikes approximately in the middle of the receiver  3  or else on a receiver surface that is not shown here. According to  FIG. 4   b , the measuring beam  4  strikes the place E 1  of the receiver  3  that represents the zero point. No measuring signal is generated. 
   In  FIG. 4   c , a load F 1  causes a deformation of the rail  70 . As a result, the transmitter  2  and the receiver  3  are rotated in their relative position corresponding to the bending of the rail  70  by an angle ad 1  with respect to each other. The measuring beam  4  then strikes the receiver  3  at a place E 2  that is at a distance ΔS 1  from the point E 1 . In this manner, a measuring signal is generated that corresponds to the distance between the point E 1  and the point E 2  on the receiver  3  or on a receiver surface  3 . 1 . 
   The distance that is designated as ds 1  ΔS 1  in  FIG. 4   d  is proportional to the angular change Δα 1  and thus proportional to the force change df 1  between a resting position according to  FIG. 4   a  and the load state according to  FIG. 4   c.    
     FIG. 5  shows the position change of the measuring beam  4  from E 1  to E 2  on the receiver  3  or its receiver surface  3 . 1 . This position change generates a measuring current  11  or  12  that is transformed into a measuring voltage U 1  or U 2  by the evaluation unit  60 . The angular change Δα 1  that is proportional to the deformation or to the force application is calculated according to the following formula: 
   
     
       
         
           
             
               
                 U 
                 1 
               
               - 
               
                 U 
                 2 
               
             
             
               
                 U 
                 1 
               
               + 
               
                 U 
                 2 
               
             
           
           = 
           
             
               Δ 
               ⁢ 
               
                   
               
               ⁢ 
               
                 α 
                 1 
               
             
             = 
             
               
                 Δ 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   S 
                   1 
                 
               
               = 
               
                 Δ 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   F 
                   1 
                 
               
             
           
         
       
     
   
   According to  FIG. 6 , a normal force F Q  on the one hand and a transverse force F Y  is generated by a rolling wheel  73 , whereby F Y  runs at a right angle to F Q  as well as at a right angle to the longitudinal axis of the rail  70 . In order to detect both transverse forces F Q  and F Y , there is a need for two transmitter-receiver units  32 ,  32 ′, each having a receiver  3 ,  3 ′, that are positioned on opposite sides relative to the rail  70 . Accordingly, F Q  and F Y  are calculated according to the following formulas: 
   
     
       
         
           
             
               
                 
                   F 
                   Q 
                 
                 = 
                 
                   
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         α 
                         1 
                       
                     
                     + 
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         α 
                         2 
                       
                     
                   
                   2 
                 
               
             
           
           
             
               
                 
                   F 
                   Y 
                 
                 = 
                 
                   
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         α 
                         1 
                       
                     
                     - 
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         α 
                         2 
                       
                     
                   
                   
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         α 
                         1 
                       
                     
                     + 
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         α 
                         2 
                       
                     
                   
                 
               
             
           
         
       
     
   
     FIG. 7  shows the measuring signal of a double load cycle. Before the sensing point is reached, the wheel load relieves the rail  70  in the area of the sensing point, since the adjacent rail section is being loaded. The measuring signal has a signal drop L 1 . Once the sensing point is reached, the measuring signal jumps to a first maximum M 1  analogously to the load at the sensing point and, after the first wheel has passed, this measuring signal drops again. Subsequently, the measuring signal rises again to a second maximum value M 2  when the second wheel passes. After the passage of the second wheel, the signal drops once again to L 2 , analogously to the situation when the wheel is approaching. 
     FIG. 8  shows the rail bed depicted schematically from above, with a railroad tie  75  and a pair of rails  70 ,  70 ′. Relative to the direction of travel of the train, to the left of the transmitter-receiver unit  32  or  32 ′, there is a digital or analog detection switch  80 ,  80 ′ followed by six transmitter-receiver units  32  on each side of the rail. The transmitter-receiver units  32  here are arranged alternately on the inside and on the outside of the rail  70 . As an alternative, these can be arranged either only on the inside or only on the outside. Subsequently, there is another detection switch  81 ′. By means of the detection switch  81 ,  81 ′, the speed of the train, the number and the relative position of the wheels can be determined and the measuring segment can be activated or deactivated. 
   The measuring graph G shown in  FIG. 9   a   1 , which was determined between two railroad ties  75 ,  75 ′ or between the middle of the two railroad ties  75 ,  75 ′, is divided according to  FIG. 9   a   2  into five specific measuring points. The specific measuring points P 3  to P 7  serve for the further signal processing or correlation with a correction graph according to  FIG. 9   b   2 . 
     FIG. 9   b   1  shows a measuring graph G with a first relative maximum R 1  and a second relative maximum R 2 . These relative maxima are generated due to a flat section of the wheel and the associated alternating load of the rail. The flat section leads to a brief drop in the load and thus to a relative minimum F of the graph G. 
   In order to obtain an independent comparison graph or correction graph K, a correction graph K is determined from all graphs showing a good wheel and this graph K is shown in  FIG. 9   b   2 . The correction graph K is like an average load cycle of a perfect wheel per sensor and per train passage and thus has neither relative maxima nor relative minima. 
     FIG. 9   c   1  shows the series of all correction graphs K 1  to K 6  of six consecutive sensing points. The sensing points here cover a rail section of about 3.60 meters. This length corresponds to at least one wheel circumference. The measuring segments overlap each other here by 100 mm towards each side, thus ensuring a seamless detection of the load over the entire rail section.  FIG. 9   c   2  shows the normal load graphs N 1  to N 6  for each sensing point 1 to 6 generated by the wheel load cycles. For each normal load graph N, approximately ⅙ of the wheel circumference is shown here. Accordingly, the first half of the measured wheel has a flat section F that, according to  FIG. 9   b   1 , follows a plotted curve G. 
     FIG. 9   d  shows the ratio of the normal load graph N to the correction graph K for a wheel circumference as a load plateau, said ratio ensuring a percentage representation of the rail load with reference to the basic load. Here, the normal load graph N according to  FIG. 9   e  is the normalized mean value of all measuring graphs G of a train passage. Irregularities of each wheel or of the measuring graph G are retained here. The normal load graph N and the reciprocal value of the correction graph K are superimposed here as shown in  FIG. 9   e  and they have a shared mirror value S, by means of which the ratio shown in  FIG. 9   d  is determined according to the following formula: 
   
     
       
         
           Q 
           = 
           
             
               S 
               - 
               N 
             
             
               
                 1 
                 K 
               
               - 
               S 
             
           
         
       
     
   
   According to  FIG. 9   e  specific wheel flaws per wheel rotation can be recognized on the basis of the generated measuring graphs. According to  FIG. 9   e   1 , this is a plotting on the wheel that first generates an overload. The graph according to  FIG. 9   e   2  shows relatively high-frequency, symmetrical load changes that point towards polygons.  FIG. 9   e   3  shows a typical signal of an out-of-roundness of the wheel that leads to a symmetrical graph of a low-frequency type.  FIG. 9   e   4  shows a typical flat section of the wheel that first generates a load drop and subsequently an overload.