Field of the invention
[0001] This invention relates to an exhaust charging pump and more
specifically to an exhaust charging pump for a one cylinder diesel engine.
Background of the invention
[0002] IN Patent Application Number 4875/CHE/2015 describes an exhaust charging pump comprising a housing. The exhaust charging pump comprises a first part of the housing and a second part of the housing. A flexible member is coupled circumferentially between the first part of the housing and the second part of the housing, the flexible member facilitates varying a volume of the first part of the housing of the exhaust charging pump.
Brief description of the accompanying drawings
[0003] Different modes of the invention are disclosed in detail in the
description and illustrated in the accompanying drawings:
[0004] Figure 1 illustrates a schematic diagram of an exhaust charging pump
used in combination with a fuel injection system in accordance with this disclosure.
[0005] Figure 2 illustrates a schematic diagram of the fuel injection system in
accordance with this disclosure.
Detailed description of the embodiments
[0006] An exhaust charging pump 10 is described. The exhaust charging pump
10 comprises a housing 12, a first part 14 of the housing 12, and a second part 16
of the housing 12. A flexible member 18 is coupled circumferentially between the
first part 14 of the housing 12 and the second part 16 of the housing 12. The flexible
member 18 facilitates varying a volume of gas in the first part 14 of the housing 12
of the exhaust charging pump 10. A boost pressure sensor 20 is secured to the first
part 14 of the housing 12, the boost pressure sensor 20 adapted to sense a pressure
of gas that is present in the first part 14 of the housing 12.
[0007] In addition, a fuel injection system 22 is described. The fuel injection
system 22 comprises an engine 30 and a gas flow inlet path 32 coupled upstream

from the engine 30, the gas flow inlet path 32 adapted to channel gas to the engine 30. A gas flow outlet path 34 is coupled downstream from the engine 30, the gas flow outlet path 34 adapted to channel gas out of the engine 30. An exhaust charging pump 10 is coupled between the gas flow inlet path 32 and the gas flow outlet path 34. The exhaust charging pump 10 comprises a housing 12, a first part 14 of the housing 12, and a second part 16 of the housing 12. A flexible member 18 is coupled circumferentially between the first part 14 of the housing 12 and the second part 16 of the housing 12, the flexible member 18 facilitates varying a volume of gas present in the first part 14 of the housing 12 of the exhaust charging pump 10. A boost pressure sensor 20 is secured to the first part 14 of the housing 12, the boost pressure sensor 20 adapted to sense a pressure of gas that is present in the first part 14 of the housing 12.
[0008] Moreover, an engine control unit 36 is described. The engine control unit 36 is in electronic communication with a boost pressure sensor 20 of an exhaust charging pump 10. The engine control unit 36 is adapted to receive a first electronic signal from the boost pressure sensor 20 via a control flow path 42 that is indicative of a pressure of gas that is present in a first part 14 of a housing 12 of the exhaust charging pump 10. The engine control unit 36 is further adapted to control an opening percentage of a flow control valve 38 via the control flow path 42 to channel a predetermined quantity of exhaust gas from a gas flow outlet path 40 to an inlet of the exhaust charging pump 10 to cause an optimum quantity of fresh air and exhaust gas from being channeled from the exhaust charging pump 10 to an engine 30.
[0009] Figure 1 illustrates a schematic diagram of the exhaust charging pump 10 used in combination with a fuel injection system 22 in accordance with this disclosure. The exhaust charging pump 10 comprises a housing 12. The housing 12 comprises a first part 14 and a second part 16. The first part 14 and the second part 16 of the housing 12 may be independent of one another. The first part 14 of the housing 12 includes an air inlet port 24 and an air exhaust port 26. The air inlet port 24 channels gas within the first part 14 of the housing 12 of the exhaust charging pump 10, while the air exhaust port 26 channels compressed gas out of the housing

12 of the exhaust charging pump 10. The second part 16 of the housing 12 includes an exhaust gas port 28. The exhaust gas port 28 channels exhaust gas within the second part 16 of the housing 12 of the exhaust charging pump 10 from an engine 30 that is coupled upstream from the exhaust gas port 28 of the exhaust charging pump 10.
[0010] A flexible member 18 is coupled circumferentially between the first part 14 of the housing 12 and the second part 16 of the housing 12. The flexible member 18 may be moved upwardly when exhaust gas is channeled within the second part 16 of the housing 12 via the exhaust gas port 28 to facilitate compressing gas present in the first part 14 of the housing 12. The flexible member 18 facilitates varying a volume of the first part 14 of the housing 12 of the exhaust charging pump 10. A boost pressure sensor 20 is secured to the first part 14 of the housing 12, and has a sensor that is positioned within the first part 14 of the housing 12. The boost pressure sensor 20 is adapted to sense a pressure of gas that is present in the first part 14 of the housing 12.
[0011] Figure 2 illustrates a schematic diagram of a fuel injection system 22 in accordance with this disclosure. The fuel injection system 22 includes an engine 30. An inlet of the engine 30 is in flow communication with a gas flow inlet path 32 that supplies a combination of fresh air and exhaust gas to the inlet of the engine 30. More specifically, an upstream end of the gas flow inlet path 32 is in flow communication with an outlet of an exhaust charging pump 10 that supplies fresh air and exhaust gas to the inlet of the engine 30. The downstream end of the gas flow inlet path 32 is in flow communication with the inlet of the engine 30. An outlet of the engine 30 is in flow communication with a gas flow outlet path 34 that channels exhaust gas from the engine 30 partly for supplying to the exhaust charging pump 10 and partly for exhaust gas recirculation to the engine 30. The gas flow outlet path 34 comprises a first portion 35 and a second portion 37. The first portion 35 of the gas flow outlet path 34 is in flow communication with the second part 16 of the housing 12 of the exhaust charging pump 10. [0012] When exhaust gas is channelled within the second part 16 of the housing 12 via the exhaust gas port 28, the flexible member 18 may be moved

upwardly. The second portion 37 of the gas flow outlet path 34 is in flow communication with an exhaust gas recirculation cooler 46. Within the exhaust gas recirculation cooler 46, the exhaust gas that is channelled from the second portion 37 of the gas flow outlet path 34 is cooled before recirculation to avoid damaging the components of the fuel injection system 22. From the exhaust gas recirculation cooler 46, the cooled exhaust gas is channelled to a flow control valve 38. The flow control valve 38 controls a quantity of exhaust gas that is supplied to the exhaust charging pump 10 based on a control signal that is received from an engine control unit 36.
[0013] The exhaust gas that is supplied from the flow control valve 38 is channelled to the exhaust charging pump 10 via the gas flow outlet path 40. A boost pressure sensor 20 is coupled to the exhaust charging pump 10 and is in flow communication with the gas that is present within the first part 14 of the exhaust charging pump 10. More specifically, the boost pressure sensor 20 comprises a sensing element that is positioned within the first part 14 of the exhaust charging pump 10 and senses a pressure of the fresh air and exhaust gas that is contained within the first part 14 of the exhaust charging pump 10. The pressure of fresh air and exhaust gas that is contained within the first part 14 of the exhaust charging pump 10 is transmitted to the engine control unit 36 via the flow control path 42. Based on the pressure of fresh air and exhaust gas that is transmitted to the engine control unit 36 via the flow control path 42, the engine control unit 36 transmits an electronic signal to the flow control valve 38 via the flow control path 44, the opening percentage by which the flow control valve 38 is required to be opened to facilitate channeling exhaust gas from the flow control valve 38 to the exhaust charging pump 10.
[0014] A working of the exhaust charging pump 10 is described as an example. Exhaust gas from the engine 30 is supplied to the gas flow outlet path 34. From the gas flow outlet path 34, the exhaust gas is channeled to the first portion 35 of the gas flow outlet path 34 and the second portion 37 of the gas flow outlet path 34. From the first portion 35, the exhaust gas is channelled to the exhaust gas port 28 of the exhaust charging pump 10. Fresh air and exhaust gas is channelled to the first

part 14 of the exhaust charging pump 10. Due to the pressurized exhaust gas that is present in the second part 16 of the exhaust charging pump 10 that is channelled from the exhaust gas path 28, the flexible member 18 is lifted upwardly, thereby pressurizing the fresh air and exhaust gas that is present in the first part 14 of the exhaust charging pump 10. The pressurized fresh air and exhaust gas mixture is delivered to the inlet of the engine 30 via the air exhaust port 26 and via the gas flow inlet path 32 respectively.
[0015] Based on the engine operating condition, if it is required to vary the concentration of the fresh air and exhaust gas within the first part 14, the boost pressure sensor 20 transmits an electronic signal to the engine control unit 36 via the flow control path 42. On receiving the electronic signal by the engine control unit 36, the engine control unit 36 transmits an electronic signal to the flow control valve 38 via the flow control path 44, thereby opening the flow control valve 38 to the required opening percentage. Therein, the required volume of exhaust gas is channelled through the second part 37, cooled by means of the intercooler 46, and finally channelled to the exhaust charging pump 10 via the flow control valve 38 and the gas flow outlet path 40 respectively. Fresh air is channelled to the exhaust charging pump 10 via the fresh air inlet path 41. Therefore, by varying the opening percentage of the flow control valve 38 by means of the engine control unit 36, the required quantity of fresh air and exhaust gas is supplied to the exhaust charging pump 10 via the gas flow outlet path 40. From the exhaust charging pump 10, the required quantity of fresh air and exhaust gas is compressed by means of the flexible member 18 by supplying exhaust gas to the second part 16 via the exhaust gas port 28. The required quantity of compressed fresh air and exhaust gas for a given engine operating point is then supplied to the engine 30 via the gas flow inlet path 32. The advantage of a boost pressure sensor 20 secured to the first part 14 of the housing 12 is that it permits for a closed look system for allowing a known quantity of exhaust gas and fresh air to be channeled from the exhaust charging pump 10 to the engine. If the quantity of exhaust gas is required to be varied to the exhaust charging pump 10, it is possible by transmitting a signal from the engine control unit 36 to

the flow control valve 38 for varying the opening percentage of the flow control valve 38.
[0016] It must be understood that the embodiments explained in the above detailed description is only illustrative and does not limit the scope of this invention. The scope of this invention is limited only by the scope of the claims. Many modifications and changes in the embodiments aforementioned are envisaged and are within the scope of this invention.

CLAIMS
We claim:
An exhaust charging pump (10), said exhaust charging pump (10) comprising:
a housing (12);
a first part (14) of said housing (12);
a second part (16) of said housing (12);
a flexible member (18) coupled circumferentially between said first part (14) of said
housing (12) and said second part (16) of said housing (12), said flexible member
(18) facilitates varying a volume of gas in said first part (14) of said housing (12)
of said exhaust charging pump (10); characterized in that
a boost pressure sensor (20) secured to said first part (14) of said housing (12), said
boost pressure sensor (20) adapted to sense a pressure of gas that is present in said
first part (14) of said housing (12).
A fuel injection system (22), said fuel injection system (22) comprising:
an engine (30);
a gas flow inlet path (32) coupled upstream from said engine (30), said gas flow
inlet path (32) adapted to channel gas to said engine (30);
a gas flow outlet path (34) coupled downstream from said engine (30), said gas flow
outlet path (34) adapted to channel gas out of said engine (30);
an exhaust charging pump (10) coupled between said gas flow inlet path (32) and
said gas flow outlet path (34), said exhaust charging pump (10) comprising:
a housing (12);
a first part (14) of said housing (12);
a second part (16) of said housing (12);
a flexible member (18) coupled circumferentially between said first part (14) of said
housing (12) and said second part (16) of said housing (12), said flexible member
(18) facilitates varying a volume of gas in said first part (14) of said housing (12)
of said exhaust charging pump (10); characterized in that

a boost pressure sensor (20) secured to said first part (14) of said housing (12), said boost pressure sensor (20) adapted to sense a pressure of gas that is present in said first part (14) of said housing (12).
3. An engine control unit (36), said engine control unit (36) in electronic communication with a boost pressure sensor (20) of an exhaust charging pump (10),
1 said engine control unit (36) adapted to:
receive a first electronic signal from said boost pressure sensor (20) via a control flow path (42) that is indicative of a pressure of gas that is present in a first part (14) of a housing (12) of the exhaust charging pump (10); and
control an opening percentage of a flow control valve (38) via a control flow path (44) to channel a predetermined quantity of exhaust gas from a gas flow outlet path (40) to an inlet of said exhaust charging pump (10) to cause an optimum quantity of fresh air and exhaust gas from being channeled from said exhaust charging pump (10) to an engine (30).