Metering System For Reducing Pollutants In Motor Vehicle Exhaust Gases

• US 20080092527A1
• Filed: 09/09/2005
• Published: 04/24/2008
• Est. Priority Date: 10/02/2004
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Meingast, Ulrich, Heilig, Dirk, Buerglin, Markus, Schaller, Johannes, Ripper, Wolfgang
• Granted Patent: US 7,571,603 B2
• Time in Patent Office: Days
• US Class Current: 60/286
• CPC Class Codes: B01D 53/90 Injecting reactants
• CPC Class Codes: B05B 1/3006 the controlling element being actuated by the pressure of the fluid to be sprayed B05B11/0062 takes precedence
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2240/40 a hydrolysis catalyst
• CPC Class Codes: F01N 2260/022 using air
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/10 the substance being heated, e.g. by heating tank or supply line of the added substance
• CPC Class Codes: F01N 2610/14 Arrangements for the supply of substances, e.g. conduits
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 2610/1466 Means for venting air out of conduits or tanks
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 3/303 Filtering additional air
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

The invention relates to a metering system for injecting pollutant reducing medium into an exhaust system includes a metering pump, and at least one self-opening nozzle for injecting fluidic media into the exhaust gas system. The nozzle is self-opening with a needle chamber, a nozzle needle and a spring chamber with a spring element. The needle chamber and spring chamber are separated by a flexible membrane which prevents fluidic media from escaping from the needle chamber into the spring chamber, and also permits an excess pressure to prevail in the needle chamber in relation to the spring chamber, causing the nozzle needle to be displaced in opposition to a spring force, thus releasing a nozzle opening. The inventive metering system is cost-effective, robust and can also be used at low operating temperatures.

Claims

1-9. -9. (canceled)

10. A metering system for metering fluid, pollutant-reducing media, in particular aqueous urea solutions, into a motor vehicle exhaust system, the system comprising,

at least one supply container for storing at least one fluid, pollutant-reducing medium,

at least one metering pump communicating with the at least one supply container, and

at least one self-opening nozzle, communicating with the at least one metering pump directly or via a pipeline system,

the self-opening nozzle having at least one supply opening for the delivery of fluid media, and at least one nozzle opening, and

the at least one nozzle opening being embodied such that through the at least one nozzle opening, fluid media can be injected into the motor vehicle exhaust system.

11. The metering system as defined by claim 10, wherein the at least one self-opening nozzle comprises, a nozzle body with a spring chamber and a needle chamber, the needle chamber having at least one supply opening for the delivery of fluid media and at least one nozzle opening and at least one nozzle needle supported movably and/or rotatably in the needle chamber in such a way that the at least one nozzle needle, in at least one position and/or orientation, tightly closes the at least one nozzle opening for fluid media and, in at least one further position and/or orientation, opens the nozzle opening for fluid media, at least one spring element in the spring chamber and exerting a force and/or a torque on the at least one nozzle needle, in such a way that without the exertion of additional forces and/or torques, the at least one nozzle needle tightly closes the at least one nozzle opening for fluid media, and at least one sealing element preventing or reducing a penetration of fluid media from the at least one needle chamber into the at least one spring chamber.

12. The metering system as defined by claim 11, wherein a fluid medium, entering the at least one needle chamber at a pressure p₁, exerts a force and/or a torque on the at least one nozzle needle, which force or torque acts counter to the force or torque exerted on the at least one nozzle needle by the at least one spring element, and wherein, if p₁ exceeds a predetermined minimum pressure p_min, the at least one nozzle opening for fluid media is opened.

14. The metering system as defined by claim 12, wherein the at least one sealing element is designed as entirely or partly flexible and wherein the at least one sealing element connects the at least one nozzle needle and/or the at least one spring element flexibly with the nozzle body.

15. The metering system as defined by claim 11, wherein the at least one sealing element has at least one flexible diaphragm.

16. The metering system as defined by claim 12, wherein the at least one sealing element has at least one flexible diaphragm.

18. The metering system as defined by claim 11, wherein the spring chamber has at least one pressure relief opening.

19. The metering system as defined by claim 12, wherein the spring chamber has at least one pressure relief opening.

21. The metering system as defined by claim 15, wherein the spring chamber has at least one pressure relief opening.

22. The metering system as defined by claim 18, wherein the at least one pressure relief opening is subjected to atmospheric pressure and/or to a pressure in the motor vehicle exhaust system.

23. The metering system as defined by claim 19, wherein the at least one pressure relief opening is subjected to atmospheric pressure and/or to a pressure in the motor vehicle exhaust system.

25. The metering system as defined by claim 21, wherein the at least one pressure relief opening is subjected to atmospheric pressure and/or to a pressure in the motor vehicle exhaust system.

26. The metering system as defined by claim 10, further comprising at least one ventilation valve embodied such that it is capable of controlling an inflow of air and/or protective gas into the at least one metering pump and/or into the at least one self-opening nozzle.

27. The metering system as defined by claim 10, further comprising at least one heating element operable to entirely or partially heat the pipeline system and/or the at least one metering pump and/or the at least one self-opening nozzle.

28. The metering system as defined by claim 10, further comprising at least one electronic control unit for controlling the at least one metering pump and/or for controlling the at least one ventilation valve and/or for controlling the at least one heating element.

29. The metering system as defined by claim 10, further comprising at least one device for measuring a temperature and/or a pressure of the fluid, pollutant-reducing medium.