METHOD AND DEVICE FOR DECREASING BRAKING NOISE LEVEL

Abstract: Method according to this invention comprises in application (or deposition) of chosen medium, most commonly in fluid form such as liquid or mixture of liquid and air, with an applicator on predetermined sections or points on the braking surface (7) of a rail brake section or plurality thereof. Said medium and quantity of said medium are chosen such that their use may not significantly impede braking characteristics and/or significantly decrease friction factor between the brake and the wheel (8) which the braking surface (7) engages and applies friction to it. A device according to this invention comprises signal generating means, at least one proximity sensor or switch (6), signal analyzing or processing means, at least one controlling unit (5), metering means for applying correct amount of said medium to delivering means, a controlled-volume pump or pumping device, distributing means for delivering of said medium and medium application means, such as a nozzle (4).

Description: METHOD AND DEVICE FOR DECREASING BRAKING NOISE LEVEL DESCRIPTION OF INVENTION Field of the invention Brakes; anti-noise devices Description of the problem During deceleration (braking) of rail vehicles or vehicles on rails one often detects noise. The technical problem which needs solution is how to decrease the level of said noise without severely affecting braking performance or lowering braking effects. State of the art The inventor is not familiar with any device which would significantly lower level of noise caused by braking and not severely affecting braking performance. Most commonly used braking devices for decreasing velocity of railway vehicles or other vehicles or rail are rail brakes. Said rail brakes comprise at least one braking surface (7) (for the purposes of this application braking surface refers to braking shoes, braking pads and other forms of parts of brake known in state of the art), most commonly devised using a section of a rail rotated by 90 degrees around its main axis. Said rail engages with side section of a wheel during braking by first moving toward said wheel and then contacting said wheel thereby increasing friction between braking surface and wheel side surface. One most commonly finds brakes in pairs in order to execute friction on both side wheel surfaces. Said braking action causes unpleasant noise. In addition to rails one may use other forms of section of beams of steel or other material (either metal or nonmetal) depending on properties of the wheel said brake engages. Description of new solution Subject of this invention are method and device for decreasing braking noise level. Method according to this invention comprises in application (or deposition) of chosen medium, most commonly in fluid form such as liquid or mixture of liquid and air, with applicator (i.e. device for application) on predetermined sections or points on braking surface of rail brake section or plurality thereof. Said medium and quantity of said medium are chosen in such a fashion that their use may not significantly impede braking characteristics and/or significantly decrease friction factor between the brake (7) and the wheel which the braking surface (7) engages and applies friction to it. A device according to this invention comprises signal generating means (in particular embodiment of this invention at least one proximity sensor or switch), signal analyzing or processing means (in particular embodiment of this invention at least one controlling unit), metering means for applying correct amount of said medium to delivering means (in particular embodiment of this invention controlled-volume pump or pumping device for pumping predetermined amount of medium into delivery system), distributing means such as system or plurality thereof for delivering of said medium (in particular embodiment of this invention a distributor or plurality thereof) and medium application means, said medium primarily comprising liquid and air (in particular embodiment of this invention a nozzle). The present invention is further explained with help of embodiments as described below and reference to the accompanying drawings whereby the drawings form part of this patent application and describe: Figure 1 position of proximity sensor(s) or switch(es) and controlled-volume (metering) pump along a rail whereby the figure shows the direction of wheel travel (A), controlled-volume pumps (la through If), proximity sensors or switches (6a through 6f), and controlling unit (5); Figure 2 shows delivery system for controlled-volume pump or pumping device (1) for a section of said braking surface (7) whereby the figure shows controlled- volume pump, mixing distributor (2), mixing distributor (3), nozzle or plurality thereof (4), controlling unit (5), proximity sensor or switch(6); Figure 3 shows cross section of said rail and rail brake with nozzle or plurality thereof whereby the figure shows schematics of controlled-volume pump or pumping device (1), mixing distributor (2), mixing distributor (3), nozzles connected in pairs (4), braking surfaces (7), wheel (8), rail. Controlled-volume pumps or pumping devices are shown in figures under number 1 and a consecutive letter whereby they do not differ significantly among themselves. Further, their distributing system is shown in Figure 2 as distributing system as applies to any of them, from la through If Similar description is used for proximity sensors or switches (6) described in figures with number 6 (denoting the fact that this is a proximity sensor or switch) and letter denoting that so described proximity sensor or switch corresponds to particular controlled-volume pump or pumping device. In a way of example, proximity sensor or switch 6a and controlled-volume pump or pumping device la correspond to each other, proximity sensor or switch 6b and controlled-volume pump or pumping device lb correspond to each other, etc. In particular embodiment of this invention a method comprises the following phases: during wheel approach (usually when the velocity of the wheel exceeds predetermined threshold velocity) said rail brake engages and the braking surface (7) engages the side of the wheel (8); - the wheel (8) engages (i.e. switches on) proximity sensor or switch (6) by means of physical contact or sensing of proximity; - the proximity sensor or switch (6) turns on controlled-volume pump or pumping device which pumps mixture of air and medium (fluid in this embodiment) to the mixing distributors (2) and (3); - mixing distributors (2, 3) distribute said mixture of air and medium among nozzles (4); - nozzles (4) apply mixture of air and medium onto the braking surfaces (7). The nozzles (4) are positioned in such a fashion in this embodiment that the resonances among the braking surfaces (7) or particular braking surface (7) and the wheel (8) are dampened or forestalled by means of asymmetrically positioning of the nozzles (4) with regard to the axis as defined by the rail. The control unit (5) controls timing of medium application (i.e. spraying) or gap between the consecutive applications. In this embodiment the nozzles (4) alternate, however, embodiment with only one nozzle (4) is also possible. In preferred embodiment the proximity sensors or switches (8) sense the wheel (8) only if the brake is activated and then enable application of medium onto the braking surface (7) which is positioned before incoming wheel (8). Figure 1 shows the activation of controlled-volume pump or pumping device (la) which applies medium onto the braking surface (7) before the wheel (8) reaches the position of the nozzles (4), said nozzles (4) connected to the controlled-volume pump or pumping device (la). In such a way predetermined applications layers of medium can be achieved in dynamic fashion, said layers of medium to be stripped off by the wheel (8) during friction between the braking surface (7) and the side of the wheel (8). This stripping-off prevents piling of medium on single spot which could result in decrease of brake performance. The control unit (5) is given parameters needed for reliable operation of the brake (7) such as velocity of the wheel etc. If the velocity of the wheel (8) exceed predetermined value the control unit (5) blocks the operation of the brake. In preferred embodiment the method for decreasing the noise of braking comprises application of mixture of fluid using pump or pumping device (1) onto the section of the braking surface (7) as determined by engaged proximity sensor or switch (6) and asymmetrically positioned nozzles (4) whereby the amount of the fluid is essentially equally distributed among the nozzles (4) belonging to the same distribution system using mixing distributors (2,3). The device according to this invention is using the method according to this invention as described above and comprises at least one controlled-volume pump or pumping device (1), at least one mixing distributor (2,3), at least one nozzle (4). The device according to this invention can be controlled via the controlling unit (5). In addition, the method and the device can form the ejected medium in long, narrow jet to be formed by said nozzle (4) or plurality thereof whereby the word narrow describes the jet not significantly widened or jet still to be considered in stable form (i.e. jet which has not yet broken). It is self evident that the described invention can be used in different embodiment without changing the essence of the invention.

Claims: CLAIMS 1. Method for decreasing braking noise level, characterized by that it comprises of application of predetermined amount of chosen medium onto predetermined positions of at least one braking surface of at least one rail brake. 2. Method according to claim 1, characterized by that a wheel moving toward said rail brake activates at least one distributing mean which using at least one distributing system distributes chosen medium, said medium primarily consisting of air and liquid and ejects said medium through at nozzle onto said braking surface in front of said moving wheel. 3. Method , according to any of preceding claims, characterized by that the application of said medium is not continuous and is controlled via controlling means. 4. Method according to any of preceding claims, characterized by that it comprises of the following steps: - during wheel approach said rail brake engages and the braking surface (7) engages the side of the wheel (8); - the wheel (8) turns on proximity sensor or switch (6) by means of physical contact or the sensor's (6) sensing of proximity; - the proximity sensor or switch (6) turns on controlled-volume pump or pumping device which pumps mixture of air and medium, preferably fluid, to the mixing distributors (2) and (3); - mixing distributors (2, 3) distribute said mixture of air and medium among nozzles (4); - nozzles (4) apply mixture of air and medium onto the braking surfaces (7) in front of the moving wheel (8). 5. Method according to any of preceding claims, characterized by that it comprises of application of the mixture of fluid using the pump or pumping device (1) onto the section of the braking surface (7) as determined by engaged proximity sensor or switch (6) and asymmetrically positioned nozzles (4) whereby the amount of the fluid is essentially equally distributed among the nozzles (4) belonging to the same distribution system using mixing distributors (2,3). 6. Device for noise reduction of brakes, characterized by that it comprises at least one signaling mean, at least one signal processing mean, at least one spraying mean and at least one medium, preferably mixture of air and liquid, distribution system connected thereto. 7. Device according to claim 6, characterized by that it is comprising at least one proximity sensor or switch (6), at least one controlling unit (5), at least one controlled-volume pump or pumping device (1), at least one mixing distributor (2,3), at least medium distributing system, said medium preferably comprised of mixture of air and liquid, and at least nozzle (4). 8. Device according to any of preceding claims, characterized in that the nozzles (4) are positioned asymmetrically relative to the axis as determined by rail whereby resonances between at least one braking surface (7) and another braking surface (7) or the wheel (8) are significantly dampened. 9. Device according to any of preceding claims, characterized in that at least one proximity sensor of switch (6a) is connected to at least one controlled-volume pump or pumping device (la). 10. Device according to any of preceding claims, characterized in that each of six proximity sensors or switches (6a, 6b, 6c, 6d, 6e, 6f) is connected to at least one of six controlled-volume pumps or pumping devices (la, lb, lc, Id, le, If). 11. Device according to any of preceding claims, characterized in that the controlling unit (5) prevents operation of the device provided that the velocity of the wheel (8) exceeds predetermined threshold velocity. 12. Device according to any of preceding claims, characterized in that medium ejected through at least one nozzle (4) is in form of long, narrow jet.

Inventors: PAVCNIK BOJAN, PAV&CCARON
Applicants: PAVCNIK BOJAN, PAV&CCARON
Application year: 2000
Main classification: B61K7
IPC codes: B61K7