Claims:1. A pump integrated gasoline injector for fitting system in the intake path on the engine cylinder head comprising :-

a. a cylindrical sleeve;
b. a hollow plunger having an integral continuous longitudinal opening, representing a fuel supply duct passage means and with a surrounding armature made of a magnetic material and moveable coaxially within the cylinder between a second home position and a first position where it opens a fuel passage and the second position where it closes the fuel passage,
c. a feeding means placed around the plunger and operative, to urge said plunger alongwith armature towards the first position,
d. a pumping means placed co-axial to plunger urging the plunger towards the second position,
e. a fuel inlet means connected at one end of the cylinder to receive fuel into plunger bore passage during an intake stroke,
f. a bottom housing with an outlet fixed conical valve seat disposed sealingly and securely at the other end of the cylinder to exit fuel from the plunger bore passage during an exhaust stroke,
g. a spring bias loaded moveable inlet check valve means disposed within the cylinder that cooperates with fixed valve seat to open and close and disposed on the upstream side of the valve seat which is upstream and which inlet check valve is movable with the plunger,
h. a spring loaded outlet ball valve means disposed within the cylinder on the other downstream side of the valve seat, said spring disposed on a ball stop type spring seat,
i. an injector nozzle means disposed within the cylinder having a swirl plate forming a swirl chamber in fluid communication with the outlet ball valve and a discharge orifice plug disposed on the other side of swirl chamber, and
j. a controller operatively connected to the solenoid, programmed for meeting the quantity of fuel injected on the basis of pumping frequency,
k. whereby the plunger being fixedly secured to and axially aligned with the armature and surrounding the plunger for unitary movement whereby actuation of the feeding means thereto effects a movement of the plunger,
l. whereby the effective volume between the bottom of the said inlet check valve and ball valve top is operational chamber which is pumping chamber and also pressure chamber of the system,
m. whereby when feeding means is actuated the plunger moves inwardly towards its first position into the cylinder alongwith armature, but the inlet check valve which is spring biased moves away from its seat and trails behind the plunger with a delay time, creating a circumferential recess around the inlet check valve in the plunger, thereby giving passage by suction for fuel to enter into the negative pressure operational chamber which is now a pumping chamber operationally and the plunger stores kinetic energy in itself due to its motion against pumping spring means,
n. whereby when feeding means is deactivated the plunger returns back outwardly towards its second home position in the cylinder, and aided by release of the engery stored in feeding means, and inlet check valve also moves back correspondingly to position itself again on the valve seat, thereby closing the recess created previously around the inlet check valve in the plunger, thereby giving no passage for further fuel to enter into pumping chamber, and thereby forming a pressure chamber in the operational chamber, and the plunger transfers its stored energy into the fuel in the said chamber which is now pressure chamber operationally,
o. whereby the fuel is compressed in the pressure chamber by the pumping means until the outlet ball valve is opened against the force of the pressurized fuel within the pressure chamber to inject outwardly the pressurized fuel from the system through the discharge orifice plug.

2. The integrated system as claimed in claim 1, wherein fuel may be fed into the system by gravity.

3. The integrated system as claimed in claim 1, wherein a fuel may be at a low pressure between the remote fuel tank and the system.

4. The integrated system as claimed in claim 1, wherein a filter means may be included near the fuel inlet means.

5. The integrated system as claimed in claim 1, wherein the ball valve is a non-return valve.

6. The integrated system as claimed in claim 1, wherein the inlet check valve is a non-return valve.

7. The integrated system as claimed in claim 1, wherein the feeding means may be solenoid means and pumping means may be a spring means.

8. The integrated system as claimed in claim 1, wherein the feeding means may be spring means and pumping means may be a solenoid means.

9. The integrated system as claimed in claim 1, wherein the feeding means may be solenoid means and pumping means may be a solenoid means.
, Description:FIELD OF THE INVENTION
A Two-wheeler engine fueling injection technology and more specifically a pump integrated gasoline injector.

PRIOR ART
The conventional PFI solution involves a fuel injector placed in the intake path near the intake port as shown in Figure 2. The injector receives pressurized fuel from an electric pump placed inside the fuel tank. The injector and pump are connected by necessary pipelines suitable for handling the injection pressures. The injector is commanded by the ECU with a pulse, to inject the fuel at the required timing and for the required opening duration. The opening duration of the injector is varied to match the fuel injection quantity, and the injection event is timed to produce the best engine performance and less emissions. For best three way catalytic conversion, an air fuel ratio close to that of stoichiometric is preferred, and this is maintained with the help of a lambda sensor feedback. The ECU takes the feedback from the lambda sensor and corrects the fuel injection pulse duration to maintain close to stoichiometric air fuel ratio.

1) Integrated pump and injector for exhaust after treatment US 8225602 B2
2) Electrically operated fuel injection apparatus US 6964263 B2
3) Fuel injection device according to the solid-state energy storage principle for internal combustion engines US 5469828 A

SUMMARY TO THE INVENTION
Port fuel injection (PFI) is a widely accepted fuel injection system for gasoline engines, as it offers a very good control over emissions by using closed loop corrections.

However PFI system uses a separate injector, in-tank pump and necessary line components for application.

Invention has aimed to develop a simplified injection system that can be applied for such port fuel injection in two-wheelers.

In this innovative design, the pump and injector are integrated into a single unit, making the system simple, compact and less expensive.

The concept described here was developed as part of the research work to arrive at a new product with a novel concept. This concept was arrived at to offer an alternate fueling system for gasoline engines. A series of simulations were performed to test the concept of this fueling system. The purpose of the work is to simplify the fuel injection system by integrating the pump into the injector itself.

In spark ignited engines, the gasoline fuel is generally introduced into the engine by port fuel injection (PFI) or gasoline direct injection (GDI), though carburetion is still widely used in developing countries. China and India have more than 50 % and 20% of the global two wheeler population respectively. Currently majority of these two wheelers are fueled by carburetors owing to their low cost and ease of maintenance. As these nations try to adopt emission norms similar to that of Euro 6 in a few years from now, they will be migrating to an injection system like port fuel injection (PFI) as closed-loop correction becomes difficult with the carburetor. The PFI having precise metering and flexible timing characteristics, is a widely accepted fuel injection system for stringent emission norms, as it offers a very good control over emissions by using closed loop corrections based on lambda input.

Applicant has developed an innovative injection system that can be applied for such port fuel injection in two-wheelers. In this innovative design, the pump and injector are integrated into a single unit, making the system simple, compact and less expensive. The integrated injector uses a solenoid and spring arrangement for pressurizing the fuel in a small chamber using less current. The pressurized fuel is then injected through orifice to produce spray in the intake port of the gasoline engine. The spray gets mixed with the air near the intake port and gets ready for the combustion event as shown in with engine layout in Figure 1. Though two-wheeler engines could especially benefit from this system, the system could be applied to larger automotive engines as well.

DESCRIPTION OF THE INVENTION
The solution involves the design of an injector with a fuel supply pump integrated in it as indicated in Figure 3. The pressure required for fuel injection is generated by the force of a spring, where the spring is compressed by an electromagnetic force produced by a solenoid, prior to the injection event. This design eliminates the need for a separate fuel pump to be placed inside the fuel tank for feeding the pressurized fuel and also eliminates an in-tank filter.

The fuel is fed into the injector through the inlet tube by gravity from a fuel tank. A filter placed at the exit of the inlet tube, protects the injector from debris entering into it. The solenoid is energized with an electric pulse with a potential difference of 12 V just prior to the injection event. On energizing the solenoid, a magnetic flux is generated, which pulls the armature up against the spring force. The lift of armature is controlled by controlling the magnitude and duration of the energizing current supplied to the solenoid. A plunger attached to the armature also moves along with it. A check valve assembly is attached to the bottom of the plunger, which also moves along with the plunger. The check valve assembly consists of a check valve loaded by a spring, both attached to the plunger. However, the check valve moves with a relatively lesser speed owing to the low pressure produced below the check valve. This low pressure is caused by the increase in the volume produced between the plunger bottom and the ball valve top. The effective volume available between the bottom of the check valve assembly and the ball valve top is essentially the ‘pumping chamber’ of the injector. The low pressure generated in the pumping volume allows the fuel to pass through the clearance between the plunger and the check valve, during the upward motion of the plunger, during solenoid energization. The fuel gets filled up in the pumping chamber during the plunger’s upward motion. As the solenoid is de-energized, the plunger unit along with the check valve moves downwards due to the action of spring force. The spring force pushes the plunger - check valve unit downwards and causes pressure rise in the pumping chamber.

The ball valve, which acts as a non-return valve, opens and allows the high pressure fuel, to pass through the small orifices below, to produce injection spray, suitable for mixing with the engine intake air. Upon completion of the injection, the spring attached to the ball pushes it upwards, back to its seat, thus breaking the communication between the pumping chamber and the air intake path of the engine. This non-return action of the ball avoids any trapping of air into the pumping chamber. The fuel can exit through direct orifice holes of nozzle as shown in Figure 4 or alternatively with a swirler arrangement, to produce swirl motion, in the presence of a swirl plate and orifice plug after the ball stop as shown in Figure 5.

The pumping of fuel and retraction of plunger for the PIGI can be done using several methods as shown in the following figures. Figure 6 illustrates Spring pumping solenoid retraction mechanismFigure 7 illustrates solenoid pumping solenoid retracting mechanismFigure 7 illustrates solenoid pumping solenoid retracting mechanism Figure 8 shows the method of pumping work done by the solenoid and the plunger retraction done by the spring.

The PIGI injector is placed in the air intake path of the engine as shown in figure 9. Similar to the way it is done in the conventional PFI engines. The PIGI’s solenoid is energized as and when it receives pulse from the ECU. Conventional PFI injectors would be typically consume current in the order of less than 1 Amp, whereas PIGI demands a current of even up to 6 Amps depending upon the injection quantity. PIGI demands more current as it also does the job of pumping. The close-up view of the injector placement near the air intake port is show in Figure 10.

The hydraulic performance of the PIGI was simulated using a l-D model and the results are shown in the following figures. Figure 11, Figure 12 and Figure 13 shows the results of hydraulic performance for 0.2mm, 0.5mm and 0.9mm plunger lifts respectively. For the same fixed duty cycle of the solenoid, the discharge quantity of the injector could be varied by changing the plunger displacement limits. It could be seen that the discharge quantity increases with an increase in the plunger displacement values. As the plunger lifts up, overcoming the spring force, the pumping chamber experiences a negative pressure, which causes the fuel to get filled in, during the solenoid’s energization period. The filling-in period increases for higher plunger displacement values. After de-energizing the solenoid, the spring force, pushes the plunger down, causing a pressure rise in the pumping chamber and transfer of fuel into the nozzle chamber after passing through the non-return valve. As the filled-in fuel quantity is increased. with increased plunger displacements, the injected quantity also increases. The pressure however decreases for higher plunger displacements, owing to the reduction in the plunger momentum as the filled-in fuel quantities are more. This is evident from the increase in the time (falling droop) of the plunger, to come back to its home position (0 mm lift).

In one aspect the invention relates to a pump integrated gasoline injector for fitting system in the intake path on the engine cylinder head. It comprises of a cylindrical sleeve. It has a hollow plunger having an integral continuous longitudinal opening, representing a fuel supply duct passage means and with a surrounding armature made of a magnetic material and moveable coaxially within the cylinder between a second home position and a first position where it opens a fuel passage and the second position where it closes the fuel passage. It has a feeding means placed around the plunger and operative, to urge said plunger alongwith armature towards the first position. It has a pumping means placed co-axial to plunger urging the plunger towards the second position. It has a fuel inlet means connected at one end of the cylinder to receive fuel into plunger bore passage during an intake stroke. It has a bottom housing with an outlet fixed conical valve seat disposed sealingly and securely at the other end of the cylinder to exit fuel from the plunger bore passage during an exhaust stroke. It includes a spring bias loaded moveable inlet check valve means disposed within the cylinder that cooperates with fixed valve seat to open and close and disposed on the upstream side of the valve seat which is upstream and which inlet check valve is movable with the plunger. It also includes a spring loaded outlet ball valve means disposed within the cylinder on the other downstream side of the valve seat, said spring disposed on a ball stop type spring seat. It has an injector nozzle means disposed within the cylinder having a swirl plate forming a swirl chamber in fluid communication with the outlet ball valve and a discharge orifice plug disposed on the other side of swirl chamber. A controller operatively connected to the solenoid, programmed for meeting the quantity of fuel injected on the basis of pumping frequency. The operation of the arrangement is such that the plunger being fixedly secured to and axially aligned with the armature and surrounding the plunger for unitary movement whereby actuation of the feeding means thereto effects a movement of the plunger, whereby the effective volume between the bottom of the said inlet check valve and ball valve top is operational chamber which is pumping chamber and also pressure chamber of the system. The feeding means is such that when feeding means is actuated the plunger moves inwardly towards its first position into the cylinder alongwith armature, but the inlet check valve which is spring biased moves away from its seat and trails behind the plunger with a delay time, creating a circumferential recess around the inlet check valve in the plunger, thereby giving passage by suction for fuel to enter into the negative pressure operational chamber which is now a pumping chamber operationally and the plunger stores kinetic energy in itself due to its motion against pumping spring means. Further when feeding means is deactivated the plunger returns back outwardly towards its second home position in the cylinder, and aided by release of the engery stored in feeding means, and inlet check valve also moves back correspondingly to position itself again on the valve seat, thereby closing the recess created previously around the inlet check valve in the plunger, thereby giving no passage for further fuel to enter into pumping chamber, and thereby forming a pressure chamber in the operational chamber, and the plunger transfers its stored energy into the fuel in the said chamber which is now pressure chamber operationally. The fuel is compressed in the pressure chamber by the pumping means until the outlet ball valve is opened against the force of the pressurized fuel within the pressure chamber to inject outwardly the pressurized fuel from the system through the discharge orifice plug.

In another aspect, the fuel may be fed into the system by gravity which essentially allows the fuel to be transported and transferred easily.

In another aspect, fuel may be at a low pressure between the remote fuel tank and the system, which makes the system safer and simpler

In another aspect, a filter means may be included near the fuel inlet means to avoid the entry of debris and dirt.

In another aspect, the ball valve shall be a non-return valve for the efficient working in of the system.

In another aspect, the inlet check valve is a non-return valve.

In another aspect, the arrangement gives the flexibility of using optional feeding means and pumping means such as that the feeding means may be solenoid means and pumping means may be a spring means.

In another aspect the flexibility of arrangement allows use of feeding means which may be spring means and pumping means may be a solenoid means.

In another aspect the arrangement may have feeding means which is solenoid means and pumping means which is solenoid means.

The inventive step of this application lies in :

o The injector unit has a liquid inlet port and internal liquid flow passages from the inlet port connected to a discharge nozzle.
o The injector unit includes an electromagnetic pump and injection nozzle that are operatively connected in a common housing to spray liquid into the air intake pipe of engine.
o The electromagnetic pump is a solenoid driven pump.
o The solenoid drives a reciprocally actuated pumping plunger situated in a pumping sleeve.
o The pumping chamber is fluidly connected to the spray nozzle, having discharge orifice at the lower end of the injection unit.
o A pump controller actuates the solenoid with a variable reciprocating stroke on said centerline and with variable frequency, thereby controlling the quantity of liquid pressurized in said pumping chamber and sprayed into the intake pipe.
o The liquid supply line has one end in fluid communication with the fuel tank and another end in fluid communication with the air intake port, whereby the liquid in the fuel tank, supply line and the intake port are at substantially ambient pressure.

1) The pump mentioned in our invention is an electro-magnetic reciprocating solenoid type, whereas conventional in-tank pumps are rotary type. In-tank rotary electric motor pumps run continuously, whereas the proposed PIGI pump works only during the short injection event.
2) In-tank fuel pump’s delivery pressure is usually fixed and a pressure compensator is used to nullify the intake manifold pressure drop effect due to throttling. Our proposal facilitates to change the pumping pressure itself to the desired level. This can potentially eliminate the pressure compensator as well.
3) In this invention, the spring does the pumping work and the solenoid does the retraction. We have also suggested other two possible combinations for pumping and retracting.
4) Less power is consumed, as the electric energy is spent for a short duration to just overcome the spring force
5) Capable of producing pressures upto 10 bar due to this impulse action
6) The discharge quantity is controlled by varying the plunger lift in this work
7) The incoming fuel passes through the magnet pole and plunger bore before reaching the pumping chamber
8) The fuel passes through the clearance of the check valve attached to the plunger to get into the pumping chamber
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates PIGI on spark ignited gasoline engine
Figure 2 illustrates Conventional PFI spark ignited engine
Figure 3a illustrates Pump Integrated Gasoline Injector (PIGI)
Figure 3b illustrates PIGI – pumping/injection elements in projected view
Figure 3c to 3j illustrates PIGI functional description and so also the component level items with arrangements of assembly
Figure 4 illustrates Ball stop with direct exit holes
Figure 5 illustrates Swirler arrangement
Figure 6 illustrates Spring pumping solenoid retraction mechanism
Figure 7 illustrates solenoid pumping solenoid retracting mechanism
Figure 8 illustrates Solenoid pumping spring retraction mechanism
Figure 9 illustrates Picture showing PIGI positioned in the engine air intake path
Figure 10 illustrates Close-up view of the PIGI in the intake port of the engine
Figure 11 illustrates Hydraulic performance of PIGI at 0.2 mm plunger lift
Figure 12 illustrates Hydraulic performance of PIGI at 0.5 mm plunger lift
Figure 13 illustrates Hydraulic performance of PIGI at 0.9 mm plunger lift

PART NUMBER PART NAME
1 Exhaust valve
2 Cylinder
3 Piston
4 Spark Plug
5 Intake valve
6 PIGI Injector
7 Reservoir
8 Fuel Sender Unit
9 Filter
10 Intake Pump
11 Inlet Tube
12 Magnet pole
13 Magnet Coil
14 Armature
15 Sleeve
16 Injection Orifices
17 Ball Valve
18 Check Valve
19 Plunger
20 Spring
21 Plunger assembly rests on sealing seat, awaiting
next event
22 Magnetic flow path when energized
23 Plunger assembly moves upward
24 Inlet check Opens
25 Fluid flow charges chamber
26 Energized for ‘X’ time, until plunger hits stop + inlet
check closes
27 Current removed, magnetic field decays rapidly
28 Spring applies load, moves plunger assembly downward
29 Pressure builds in pumping chamber
30 Outlet check opens at < 0.5 bar
31 Fluid injected into exhaust stream (7-8 bar)
32 Pressure rapidly builds to 9-10 bar in pumping + outlet chambers
33 De-energized for time ‘Y’, until plunger assembly
comes to rest in downward position against seat
34 Outlet check closes
35 Pressure decays
36 Pumping Spring
37 Plunger Armature Assembly
38 Outlet Ball Valve and spring
39 Spring Seat
40 Swirl Plate
41 Orifice Plug
42 Ball Stops
43 Exhaust Manifold
44 Intake port
45 Intake manifold
46 Throttle
47 INLET FITTING
48 OVERMOLD FRAME ASSEMBLY
49 SEAL ORING
50 FILTER INLET
51 TUBE STOP
52 MAGNETIC BREAK
53 SPRING INLET CHECK
54 SEAL ORING
55 COVER WASHER
56 SLEEVE PLUNGER
57 SEAL,OUTLET CHECK
58 BALL
59 CUB BALL
60 SPRING OUTLET CHECK
61 STOP OUTLET CHECK

Although the invention has been described above with reference to preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.