FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF INVENTION Fuel Injection System Assembly
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Jayagopal S & Arunendra Mishra
Both Indian Nationals
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the
manner in which it is to be performed.

FIELD OF INVENTION
This invention relates to automotive engine technology and more particularly to injection system assembly for multipoint sequential gas injection system.
BACKGROUND OF INVENTION
Recently, the importance has been placed on the cleanliness of exhaust gas by reducing the pollutants like C02, CO, NOx and HC. There are limitations to meet these requirements using liquid Fossil Fuels in conventional IC engines. So, past decades have seen an increased demand for use of gaseous fuel as a fuel source in both compression and spark ignition engines. Gaseous fuels combustion engines that burn natural gas, petroleum gas, and hydrogen gas produces less emission from tail pipe.
To meet the IC engine requirement for Gaseous fuel system, a technological need has arisen for safe & precise fuelling system. To have higher control on Fuelling & Safe handling of gaseous fuels particularly, hydrogen gas to avoid back-fire in engine a Multipoint Sequential Gas injection system has adopted. Multipoint Sequential Gas injection consist one or more injectors per cylinder. To adopt these injectors on intake manifold an injector assembly unit has invented. This invention is related to the design of components of injector holding units and positioning of injectors on intake manifold. Injector arrangement assembly ensures the leak-proof design.
SUMMARY OF INVENTION
This invention is about the design of components, which are being recommended for Multi Point gas Injection system and preferably in a dedicated (100 %) hydrogen IC engine. The invention has the capability ensure leak-proof fueling system and safe running of multi-cylinder engine without back-fire.


Further, this Fuel Injection System Assembly provides sitting arrangement of
injectors on intake manifold of engine.
Further, the arrangement restricts relative movements of injectors.
The objective of the present invention is an injection assembly wherein two injectors are connected to the two different runner pipes (of two different cylinders) connecting between the air intake plenum and cylinder to achieve required flow rate in all running condition.
To withstand vibration and to accommodate injectors on runner pipe, the injector assembly has been designed and adopted in the system. This assembly provides leak proof arrangement for Multipoint Sequential gas injection. The twin injectors' assembly unit comprises housing, which horizontally divided in upper and lower plate. These two (Twin injectors) injectors are assembled in single unit and inject the fuel in the adjacent cylinder's port.
According to present invention an assembly for fuel injection system for use with an internal combustion engine having plurality of cylinders, said assembly comprising; a common gas plenum, plurality of injectors, plurality of flexible metal pipes connected between the outlets of said common gas plenum and said injectors using end connectors, wherein at least two injectors communicating with air intake runner pipes of adjacent cylinders are held together in pairs.
BRIEF DESCRIPTION OF DRAWINGS
For complete understanding of this invention a preferred exemplary embodiment of the invention is illustrated in the accompanying drawings, in which like reference numerals represent like parts throughout, and in which:
FIG .1 shows schematic diagram of IC Engine, Hydrogen Storage and Supply System.


FIG. 2 shows common Rail and Injectors arrangement
Fig. 3 shows the injection system assembly in accordance with this invention.
Fig. 4 shows the injectors assembly of this invention.
Fig. 5 shows the cross section of injector assembly.
Fig. 6 shows the upper-plate used in injector assembly.
Fig. 7 shows the bottom-plate used in injector assembly.
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.
An embodiment of this invention is described in FIGURE 1. The Internal Combustion Engine comprising Six cylinders, Pistons, 2 valves per cylinder, Ignition Coils, Cylinder block, Cylinder Head, Cam shaft, Push-Rod, Plenum chamber, Fuel Rail, Hydrogen Injectors(2 per cylinder), Crankshaft, Accessories Drives etc. Hydrogen gas is stored in Composite cylinders (10). These cylinders consist in-built High-Pressure Regulator (11). Low pressure line (13) carries hydrogen gases to electronics Low-Pressure Regulator (14), which converts high pressure to working level pressure. Electronically controlled low-pressure line (15) carries hydrogen gases to common rail (16). Electronically controlled low pressure regulator which in turn connected to fuel storage through higher pressure regulator and a solenoid gas shutoff valve. The other end of common rail consist a low pressure sensor (31) to monitor the rail-pressure. Flexible metal pipes (26, 17) carry Hydrogen gas to hydrogen injector (44). Intake manifold (19) consists of plenum chamber (30), TMAP Sensor (24) and Electronically Controlled Throttle body (23). In the intake port (22), the Air is delivered to cylinder through intake valves, the valve Opening & Closing controlled by a cam shaft. Upper slot (25) and side slot (27) are provided on intake runner pipe (22). The exhaust port (21) is provided with exhaust valve, the valve opening and closing controlled by a cam.


FIGURE 2 & FIGURE 3 are provided to explain the configuration of present invention. The engine cylinder (36) is communicated with intake runner (22) and exhaust port (not shown in figure) for Air & Fuel in-flow and Burned Gas out-flow respectively. An intake valve (35) is provided between intake port and in cylinder space (36) of internal combustion engine. Common rail (16) is mounted on top of plenum chamber (30).
The gas flows from Common rail plenum (16) to injectors (44) through flexible pipes (17,26). These injectors (44, 49) are controlled by ECU for safe opening and closing in sequential with respect to firing order. The intake runner pipe (22) is in fluid communication with plenum (30) and length is tuned for Ram Effect, it delivers air to individual cylinder inline with intake valve timing. Air-flow rate to the plenum has been controlled by an Electronically Controlled Throttle-body (23) as shown in figure 1, which is assembled at upper stream of intake (plenum). To withstand vibration and to accommodate injectors on runner pipe, the new assembly (45) has been designed and adopted in the system. This assembly (45) provides leak proof arrangement for Multi-Point Sequential Gas Injection system. The twin injector assembly unit (45) comprises a housing, which horizontally divided in upper and lower plate. These two injectors are assembled in single unit and inject the fuel in the adjacent cylinders. The complete assembly (Fuel Rail, Injectors, Flexible pipe) has been assembled on intake system through two brackets (48).
The volume of common rail pipe is decided by considering rail as fuel plenum chamber. The constant rail pressure is maintained through out the engine operation and the low-pressure sensor is used to ensure the leak-proof hydrogen flow for safer usage. Low-pressure electronically controlled pressure-regulator (14) keeps the rail pressure constant. One end of the rail (16) is connected to hydrogen inlet from storage and the other part is connected with a low-pressure (31) sensor. In this assembly the Flexible metal pipes (17, 26) connected between fuel rail and injector, such a way that to meet the vibration test & leak-proof joints with higher reliability.


Connectors (40, 41) are used to connect the flexible metal pipe to common rail and injector. The common rail plenum assembly and fluid lines are made of stainless steel.
FIGURE 4 and FIGURE 5 illustrate arrangement method of twin injector (44, 44a). The injectors are injecting fuel into adjacent cylinders through runner pipes (22,22a). The arrangement of this invention ensures the leak proof design for gaseous fuel application including lighter gas like hydrogen. The flexible metal pipe (26) is connected to a connector (41). The connector (41) has been welded circumferentially on one side of upper plate (47) and another side of plate (47) injector is inserted to a vertically cylindrical collar (70). Two O-rings are provided on either side of injector to seal gas leakages from the system. To hold & keep two injectors parallel and to withstand vibration the bottom plate (46) is provided. This plate (46) is having slots to fix injectors. To ensure the O-ring sealing at Inlet and Outlet of Injector, the distance between these two plates to be maintained. This distance is ensured by introducing a sleeve spacer (50) of desired length. This sleeve spacer (50) is kept between the top & bottom plates (47 & 46) and plates are fastened through long bolt (51). Further bottom plate is fastened with cylinder head cover through studs. FIGURE 5 shows the section view of the same arrangement. The complete arrangement covers two adjacent intake ports (22, 22a) for two adjacent cylinders for fueling (Multipoint Sequential Gas Injection). Numbering with suffix "a" indicates the same component for adjacent cylinder.
FIGURE 6 illustrates Upper Plate (47) design; it has pair of vertically cylindrical collars (70,70a) at desired centre-to-centre distance on bottom to connect the injectors (44, 44a). The upper plate is also having pair of circular recess (72,72a) to position the connector (41, 41a). Holes (71,71a) provided in the centre of the recess to communicate between recess (72) and bottom cylindrical collar (70,70a) spaces for gas flow. The connectors (41, 41a) are inserted to the top recesses and welded circumferentially to hold it rigidly. Injectors (44, 44a) are inserted to the bottom cylindrical collar and being sealingly disposed with a hard rubber washer (52) kept


between the injector top and the plate. The injectors are held in position by using a bottom plate (46) fastens to the upper plate using sleeve spacer (50) and longer bolt (51). During the injection, the fuel flows from the fuel rail to connector (41) through flexible metal pipe (26) and further the connector (41) communicated to injector through the hole (71) provided on the upper plate.
FIGURE 7 shows bottom Plate (46), U-Slots (61,61a) provided with flange to hold the Injector through the groove(on injector). The circular step (62) is provided to align the sleeve assembly and fix the vertical spacer (50) to maintain the distance between the Top & Bottom plates. Hole (60) is used for fastening Twin-injector assembly on the Intake system by ensuring the injectors are at desired position at adjacent cylinders.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art, without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.


WE CLAIM
1. An assembly for fuel injection system for use with an internal combustion engine having plurality of cylinders, said assembly comprising; a common gas plenum, plurality of injectors communicating with air intake paths of runner pipes, plurality of flexible metal pipes connected between the outlets of said common gas plenum and said injectors using end connectors, wherein at least two injectors communicating with air intake runner pipes of adjacent cylinders are held together in pairs.
2. The assembly for fuel injection system as claimed in claim 1, wherein said pair of injector is held together using upper and lower plate.
3. The assembly for fuel injection system as claimed in claim 2, wherein said upper plate is having, a pair of cylindrical collar located at bottom and top of said injectors are disposed therein, a pair of recess at top to locate the connectors, said collar and recess are concentrically aligned and fluidly connecting through an axial hole on said plate.
4. The assembly for fuel injection system as claimed in claims 2 and 3, wherein said bottom plate having pair of U slot to locate said injectors.
5. The assembly for fuel injection system as claimed in claims 2 and 3, wherein said upper and lower plates are rigidly connected using a spacer and said bottom plate is fastened to air intake system.
6. The assembly for fuel injection system as claimed in claims 1 and 2, wherein said pair of injectors positioned to inject fuel into adjacent cylinders.
7. The assembly for fuel injection system as claimed in claim 1, wherein said connectors are circumferentially welded to said top plate.


8. The assembly for fuel injection system as claimed in claim 1, wherein said injector is sealingly disposed in said cylindrical collar.
9. The assembly for fuel injection system as claimed in claim 1 wherein said bottom plate having flanges in U slots to fit with circumferential groove of said injector.
10. The assembly for fuel injection system substantially as herein described with reference to accompanying drawings.




ABSTRACT
Fuel Injection System Assembly
This invention relates to an assembly for fuel injection system for use with an internal combustion engine having plurality of cylinders, said assembly comprising; a common gas plenum, plurality of injectors communicating with air intake paths of runner pipes, plurality of flexible metal pipes connected between the outlets of said common gas plenum and said injectors using end connectors, wherein at least two injectors communicating with air intake runner pipes of adjacent cylinders are held together in pairs.