Claims:We claim:

1. A lambda sensor arrangement (120) in an exhaust conduit (104) of a vehicle (100), said lambda sensor (110) comprises an electrical heater, characterized in that,
said lambda sensor (110) is positioned within a predetermined distance (122) from an exhaust port (116) of an engine (102) to prevent contact with condensed water in said exhaust conduit (104).

2. The arrangement (120) as claimed in claim 1, wherein said electrical heater is activated to bring said lambda sensor (110) to a working temperature upon detection of a start of said engine (102) of said vehicle (100).

3. The arrangement (120) as claimed in claim 1, wherein said predetermined distance (122) is selected from a range of distances comprising, a first range from 0 mm to 200 mm, and a second range from 200 mm to 700 mm.

4. The arrangement (120) as claimed in claim 3, wherein said lambda sensor (110) positioned as per said second range is protected by at least one of a Thermal Shock Protection (TSP) coating material and a Thermal Shock Protection (TSP) tube.

5. The arrangement (120) as claimed in claim 1, wherein said exhaust port (116) comprises a first end (118) interfaced with an exhaust conduit (104) and a second end (114) in association with an exhaust valve (112), wherein said predetermined distance (122) is considered from said first end (118) of said exhaust port (116).

6. The arrangement (120) as claimed in claim 1, wherein said engine (102) of said vehicle (100) comprises at least one cylinder.

7. The arrangement (120) as claimed in claim 1, wherein said lambda sensor (110) is a narrow-band lambda sensor.

8. The arrangement (120) as claimed in claim 1, wherein said vehicle (100) is any one of a motorcycle, a scooter, a moped and an auto-rickshaw.
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

Field of the invention:
[0001] The present invention relates to a controller for a lambda sensor arrangement in an exhaust conduit of a vehicle.

Background of the invention:
[0002] A closed loop operation of an engine with the feedback from an exhaust gas sensor (also known as lambda sensor/ oxygen sensor) reduces the emissions from the exhaust tail pipe or conduit. The closed loop operation is limited initially due to the presence of condensed water in the exhaust pipe. The engine exhaust contains water in the evaporative form which condenses when comes into contact with a wall surface of the exhaust conduit. The condensed water is accumulated majorly in the lowest portion of muffler, near the bends or troughs. A heated exhaust gas oxygen sensor is subjected to high thermal stress when exposed to the water, leading to breakage of the exhaust gas sensor. Therefore, heating of the exhaust gas sensor is inhibited and operating the engine in open loop (preventing engine to go into closed operation), thereby increasing emissions in the initial start time of the engine.

[0003] According to a prior art US7552586 a marine exhaust system with a downstream oxygen sensor located away from a water reversion liquid trajectory path is disclosed. The marine engine exhaust system has an oxygen sensor located within a catalyst housing structure and downstream from a catalyst device. The oxygen sensor is located away from a reversion liquid trajectory path that defines the likely path of liquid water flowing in a reverse direction through the marine engine exhaust system toward a plurality of exhaust ports of the engine. By locating the oxygen sensor away from this reversion liquid trajectory path, the likelihood of damage to the oxygen sensor from contact with liquid water is significantly reduced.

[0004] Thus, there is a need of arranging the exhaust gas sensor to achieve faster closed loop operation of the engine and also to reduce emissions.

Brief description of the accompanying drawings:
[0005] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0006] Fig. 1 illustrates a lambda sensor arrangement in an exhaust conduit of a vehicle, according to an embodiment of the present invention.

Detailed description of the embodiments:
[0007] Fig. 1 illustrates a lambda sensor arrangement in an exhaust conduit of a vehicle, according to an embodiment of the present invention. The lambda sensor 110 comprises an electrical heater (not shown). The lambda sensor arrangement 120 (hereinafter referred to as arrangement 120) is characterized by, the lambda sensor 110 positioned within a predetermined distance 122 from an exhaust port 116 of an engine 102 to prevent contact with condensed water in the exhaust conduit 104. The arrangement 120 enables instant activation of the electrical heater in order to bring the lambda sensor 110 to a working temperature, upon detection of a start of the engine 102 of the vehicle 100. The arrangement 120 prevents any damage to the heated lambda sensor 110 by avoiding contact with condensed water of lower temperature. The arrangement 120 facilitates reduced exhaust emissions due to quicker closed loop operation of the engine 102, which also minimizes impact of condensed water on the lambda sensor 110. A controller (not shown) is used to activate the electrical heater of the lambda sensor 110 as soon as the start of the engine 102 is detected. In an embodiment, the controller is an Engine Control Unit (ECU) of the vehicle 100. In another embodiment, the controller is separate from ECU but in communication with the ECU to detect start of the engine 102.

[0008] In accordance to an embodiment of the present invention, the predetermined distance 122 is independent of a dimension of the exhaust port 116 of the engine 102 of the vehicle 100. The predetermined distance 122 is selected from a range of distances comprising, a first range from 0 mm to 200 mm, and a second range from 200 mm to 700 mm. The lambda sensor 110 which is positioned as per the second range is protected by at least one of a Thermal Shock Protection (TSP) coating material and a Thermal Shock Protection (TSP) tube, i.e. either TSP coating material or TSP tube or both. However, if the lambda sensor 110 is positioned in the first range, no TSP coating or TSP tube is required for the protection of the lambda sensor 110, but the TSP can be applied/provided on the interest of a consumer. Thus, the lambda sensor 110 with the TSP is mountable in the first range. Alternatively, the second range may be from 0 mm to 700 mm. The lambda sensor 110 is positioned around any point on the circumferential surface of the exhaust conduit 104 and is not limited to the position shown in the Fig. 1.

[0009] In accordance to an embodiment of the present invention, the vehicle 100 is a two-wheeler, a three-wheeler, a car etc. The engine displacement of the vehicle 100 is under 500 cubic centimeters (cc). Alternatively, the engine displacement of the vehicle 100 is greater than 500cc, such as 1000 cc, 1500 cc, 2000 cc and the like.

[0010] In accordance to an embodiment of the present invention, the exhaust port 116 is formed inside the engine block 108 and comprises a first end 118 interfaced with the exhaust conduit 104 and a second end 114 in association with an exhaust valve 112 . The first end 118 is shown on a surface of an engine block 108 (shown in dashed line). The exhaust conduit 104 is shown with a flange which is fixed to the engine block 108 through suitable means, such as welding, bolt, fasteners and the like. The predetermined distance 122 is considered from the first end 118 when the lambda sensor 110 is positioned or mounted on the exhaust conduit 104. Alternatively, the predetermined distance 122 is considered from the second end 114. The lambda sensor 110 is mountable in the exhaust port 116 between the first end 118 and the second end 114. In other words, the predetermined distance 122 is considered from any one of the first end 118 and the second end 114 of the exhaust port 116. If considered from the first end 118, a first distance 126 is the distance or length from the exhaust port 116. Similarly, if considered from the second end 114, a second distance 124 is the distance or length from the exhaust port 116. An arrow block in the exhaust conduit 104 represents the direction of flow of exhaust gases in the exhaust conduit 104. The exhaust port 116 is usually provided within a cylinder head of the engine 102.

[0011] The engine 102 of the vehicle 100 comprises at least one cylinder. Alternatively, the engine 102 comprises multiple cylinders such as twin-cylinder or more in “V” configuration or inline configuration. Further, the engine 102 is a spark-ignition engine (for petrol or gasoline) or a compression-ignition engine (for diesel). In one embodiment, the lambda sensor 110 is a narrow-band lambda sensor. In another embodiment, the lambda sensor 110 is a wide-band lambda sensor. A catalyst 106 is shown such as a Three-Way-Catalyst (TWC) which is used to reduce emissions as known in the art.

[0012] In accordance to an embodiment of the present invention, the arrangement 120 positions the lambda sensor 110 within the predetermined distance 122 of the exhaust port 116 in order to prevent any damage caused by dew or condensed water also known as water load. The arrangement 120 enables the engine 102 to be operated in closed loop operation with the feedback from the lambda sensor 110 faster (example during cold start condition), thus reducing emissions as per the emission legislations across various countries.

[0013] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.