Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
  • B60B39/00—Increasing wheel adhesion
  • B60B39/02—Vehicle fittings for scattering or dispensing material in front of its wheels
  • B60B39/04—Vehicle fittings for scattering or dispensing material in front of its wheels the material being granular, e.g. sand
  • B60B39/08—Vehicle fittings for scattering or dispensing material in front of its wheels the material being granular, e.g. sand the dispensing being effected by fluid means
  • B60B39/086—Vehicle fittings for scattering or dispensing material in front of its wheels the material being granular, e.g. sand the dispensing being effected by fluid means dispensing being effected by gas
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
  • B60B39/00—Increasing wheel adhesion
  • B60B39/02—Vehicle fittings for scattering or dispensing material in front of its wheels
  • B60B39/021—Details of the dispensing device
  • B60B39/023—Details of the dispensing device related to metering valves

Definitions

• the invention relates to a sand spreading device for vehicles, in particular for rail vehicles.
• Vehicles are equipped with sanding systems to improve the grip between wheels and road surface in unfavorable road conditions.
• sanding systems help to increase the adhesive value between the wheels and the rails quickly in the event of emergency braking.
• the sand is spread out in front of the wheels, so that the rail vehicles roll over a "sanded" rail with a greatly increased adhesive value.
• the effect of the sanding depends on the amount of sand applied per covered route. Ideally, a constant amount of sand should be applied per meter of travel. If too little sand is applied, the full effect of the improvement in adhesion value is not achieved. On the other hand, if too much sand is removed, there is no optimal effect.
• DE 34 10 409 shows a sanding device in which the amount of sand is metered by means of a pulsating, volumetric pump.
• DE 100 44 608 shows a sand spreading device in which compressed air is pulsed into the sand outlet of a sand container, thereby metering the amount of sand. The amount of sand brought into the area of the downpipe is then blown out by a separate compressed air stream.
• the invention has for its object to provide a simpler and more economical method for dosing the application rate.
• a sanding device with the following features:
• Sanding device for a vehicle, the sanding device having the following features: a compressed air connection with a high pressure level, a first pneumatic valve with one inlet and with two outlets, a second pneumatic valve with two inlet and with one outlet, a pressure vessel, - A sanding nozzle which is arranged in a sand container, the compressed air connection being connected to the input of the first pneumatic valve, one of the two outputs of the first pneumatic valve being connected to the pressure container, the pressure container being connected to one of the two inputs of the second pneumatic valve is connected, the other outlet of the first pneumatic valve being connected to the other inlet of the second pneumatic valve, and the outlet of the second pneumatic valve being connected to the sanding nozzle (5).
• One idea on which the present invention is based is the continuously variable pressure of the compressed air flowing into the sanding device by switching the compressed air supply on and off, smoothed by a pressure vessel. It is thus possible to make the application rate dependent on the vehicle speed.
• the invention provides a sanding system that can apply different amounts of sand depending on the inlet pressure.
• the invention also means that sand no longer needs to be replenished as often. With the invention it is possible to apply the same amount of sand per meter traveled.
• the invention provides a device that is insensitive to interference and that works continuously with compressed air.
• FIG. 1 shows a schematic illustration of the sanding device according to the invention
• FIG. 2 shows a signal curve for a magnetic valve of the sanding device from FIG. 1.
• FIG. 1 shows an exemplary embodiment of a sanding device designed according to the invention.
• the sanding device is essentially divided into a pressure reducing valve 1, to which the pressure from a pneumatic braking system of a rail vehicle is applied, into a first pneumatic valve in the form of a 3/2 way valve 2, into a second 3/2 Directional control valve 3, in a pressure tank 4, in a sanding nozzle 5, which is arranged in a sand tank, and in a brake control device 6.
• the output of the pressure reducing valve 1 is connected to the input of the first 3/2-way valve 2.
• One of the two outputs of the first 3/2-way valve 2 is connected to the pressure vessel 4 via a throttle 12 connected.
• This connection of the pressure vessel 4 is connected to one of the two inputs of the second 3/2-way valve 3.
• the other outlet of the first 3/2-way valve 2 is connected to the other inlet of the second 3/2-way valve 3.
• the outlet of the second 3/2 way valve 3 is connected to the sanding nozzle 5.
• the first 3/2 way valve 2 is designed such that its inlet is connected in a rest position to the outlet that leads to the pressure vessel 4. The outlet leading to the second 3/2-way valve 3 is then blocked. In an actuated position of the first 3/2-way valve 2, its input is connected to that output which leads to one of the two inputs of the second 3/2-way valve 3. The outlet leading to the pressure vessel 4 is then blocked.
• the second 3/2-way valve 3 is designed such that its input connected to one of the outputs of the first 3/2-way valve is connected to the output in a rest position. The input that leads to the pressure vessel 4 is then blocked. In an actuated position of the second 3/2-way valve 3, the inlet leading to the pressure vessel 4 is open and connected to the outlet leading to the sanding nozzle (5). The input that leads to the first 3/2-way valve 2 is then blocked.
• the first 3/2-way valve 2 and the second 3/2-way valve 3 can each be actuated by an electrically excitable coil against the pressure of a spring.
• Each of the coils can be automatically supplied with electrical energy by the brake control device 6, the coil of the first 3/2-way valve 2, also manually at the request of a driver via a sanding button 8, whereupon the first 3/2-way valve 2 or the second 3/2-way valve 3 passes from the idle state to the actuated state.
• a first control line 10 leads from the brake control device 6 to the first 3/2-way valve 2, a second control line 11 to the second 3/2-way valve 3.
• a scanning line 9 is also provided, via which the switching state of the sanding button 8 can be determined by the brake control device 6.
• Blocking diodes 7 prevent mutual interference between the first control line 10 and the scanning line 9. Otherwise, an electrical signal present on the first control line 10 on the scanning line 9 would be interpreted as actuation of the sanding switch 8, which is not the case.
• the sanding system according to the invention operates as follows in operation.
• the sanding system is without compressed air.
• the pressure reducing valve 1 At the inlet of the pressure reducing valve 1 there is a compressor pressure of approx. 8.5 bar, which is reduced to a constant pressure of 6 bar.
• the pressure vessel 4 begins to fill with compressed air via the first 3/2 way valve and the throttle 12.
• the second 3/2-way valve blocks the path of the compressed air from the pressure vessel 4 to the sanding nozzle 5, so that no compressed air escapes there.
• the second 3/2-way valve 3 is actuated via the second control line 11.
• the rail vehicle runs here at a relatively high speed.
• compressed air at an initial pressure of 6.5 bar emerges from the pressure vessel through the second 3/2-way valve and reaches the sanding nozzle 5.
• Compressed air is then blown into the sand vessel at high speed. The compressed air escaping there pulls sand with it, which then emerges from the exhaust pipe.
• the amount of sand escaping there can be regulated by pulsed operation of the first 3/2-way valve 2 according to the graph in FIG. 1.
• the brake control device 6 acts on the first 3/2-way valve 2 via the first control line 10 a pulsed control voltage. Because of the Called opening and closing of the first 3/2-way valve 2, the amount of compressed air flowing into the pressure container 4 of 6.5 bar is set such that a desired, lower pressure is set at the sanding nozzle 5.
• the throttle 12 and the pressure vessel 4 serve to smooth the pressure surges that arise from the pulsed operation of the first 3/2-way valve.
• compressed air at an initial pressure of 6.5 bar emerges from the pressure reducer 1 through the first 3/2-way valve 2 and through the second 3/2-way valve 3 and reaches the sanding nozzle 5.
• Compressed air is then also carried into the sand tank blown at high speed. The compressed air escaping there pulls sand with it, which then emerges from the exhaust pipe.
• the driver can influence the amount of sand emerging there to a limited extent, namely by manually pulsing the first 3/2-way valve 2.
• the driver releases the sanding button 8 and the first 3/2-way valve 2 is switched off again, so that the above-described idle state is restored. If at the same time there is a sanding request by a driver by actuating the sanding button 8 and a sanding request by the brake control device 6, then the sanding request by the driver takes precedence.
• the brake control device 6 notices the actuation of the sanding button 8 via the signal present on the scanning line 9.
• the first control line 10 to the first 3/2-way valve 2 and the second control line 11 to the second 3/2-way valve 3 are then switched off.
• the second 3/2-way valve 3 goes into its idle state.
• the first 3/2 way valve 2 remains in its actuated position due to the actuation of the cleaning button 8, so that a compressed air flow is established as described above.
• the configuration according to the invention ensures that the compressed air lines to the sanding nozzle 5 are filled quickly, both in manual and in automatic operation. This is advantageous because the air in the sand tank has to build up a certain pressure before the sand starts to trickle. Given the existing line lengths, it can still take up to one second before the first sand comes out of the blow-out pipe 14 after a sanding requirement. The invention makes it possible to keep this time as short as possible.
• the advantage of the system according to the invention is that when the rail vehicle z. B. runs at half the maximum speed and when the timing switches to "half pressure" of about 3 bar, nevertheless the full pressure is present in the pressure vessel 4 from the beginning. Then there is initially a pressure boost of 6.5 bar, which is then reduced to the 3 bar generated by clocking the first 3/2-way valve. And this pressure surge can then be done quickly at high speed quickly fill the piping and sand tank before blowing out sand at a lower pressure.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Valves And Accessory Devices For Braking Systems (AREA)
• Braking Systems And Boosters (AREA)
• Jet Pumps And Other Pumps (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34965246

Family Applications (1)

Country Status (6)

Families Citing this family (14)

Family Cites Families (8)

• 2004
  • 2004-03-24 DE DE102004014360A patent/DE102004014360B4/de not_active Expired - Fee Related
• 2005
  • 2005-03-22 CN CNB2005800131100A patent/CN100418795C/zh not_active Expired - Fee Related
  • 2005-03-22 WO PCT/EP2005/003024 patent/WO2005092640A1/de active Application Filing
  • 2005-03-22 EP EP05734133A patent/EP1729981A1/de not_active Withdrawn
  • 2005-03-22 US US10/593,952 patent/US20080012348A1/en not_active Abandoned
  • 2005-03-22 CA CA002560915A patent/CA2560915A1/en not_active Abandoned

Non-Patent Citations (1)

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