DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970) & The Patents Rules 2003

COMPLETE SPECIFICATION
(SECTION 10 and Rule 13)

TITLE

“SYSTEM FOR IMPROVING STARTABILITY OF ENGINE”

A P P L I C A N T

We, BAJAJ AUTO LIMITED, an Indian
Company, having its registered office
At Akurdi, Pune – 411035, State of Maharashtra, India.

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

FIELD OF INVENTION
The present invention relates to a system for improving startability of an internal combustion engine and more specifically, it relates to the system for resolving cold startability issue in an internal combustion engine.
BACKGROUND OF INVENTION
Cold starting problem is a common issue observed during starting of internal combustion engines. The problem is more severe during winter or rainy reason. One of the main reason is low temperature of intake fuel or gas, as lack of heat leads to difficulty in starting of an engine. During compression stroke, the temperature of intake charge does not reach to minimum threshold level for smooth ignition, which leads to difficulty in starting of the engine. The air becomes denser at low temperatures affecting the air-fuel ratio, which in turn affects the flammability of the mixture. This also leads to pollution due to uneven burning of intake charge. The problem is more prone in cases where the fuel is having higher evaporation temperature.
In order to solve the above technical problems, prior art teaches heating of intake charge, which helps in increasing its temperature, thereby quickly igniting the intake charge and starting the engine. This solution has helped in overcoming the problem of cold starting to good extent. The heating of intake fuel charge is achieved using various techniques including use of glow plug, heating plate, lamps etc.
It is well known to heat intake charge by mounting a glow plug in the cylinder head of the engine. However, in case of single cylinder engine or small capacity engines, very limited space is available on the cylinder head for mounting of the glow plug. Thus, the mounting of glow plug in cylinder head of such engines is a complex task and also difficult to manufacture small size glow plug. It also increases manufacturing cost.
Another problem observed in known systems is that the heated surface of the heating element is directly exposed to the intake fuel charge. This is very unsafe, as direct exposure of heated element to intake charge may lead to unintended combustion outside the combustion chamber and can cause serious damage to parts/systems of the engine. This problem is more prone in gasoline engine, due to its higher flammability. This may damage the glow plug, thereby reducing its life.
Provision of heating plate is another solution available in prior arts. However, such heating plate has to be mounted inside the flow path of fuel, which is complex and difficult to manufacture, as suitable mounting arrangement has to be created for mounting of such heating plate inside the intake path in a limited space without disturbing the flow of intake charge. In addition, there is possibility of explosion or fire in such arrangement. Secondly, provision of heating plate is a costly solution.
Therefore, the available solutions are complex, costly, difficult to manufacture, unsafe and occupies more space. In addition, none of prior system is providing any solution for the fuel having higher evaporation temperature.
In view of above mentioned problems of prior systems, there is a need to provide an effective heating system which is less complex, easy to manufacture, safe to operate and less costly.
OBJECT OF INVENTION
Therefore, it is an object of the present invention to provide a system for heating the intake charge of the engine, which is less complex, easy to manufacture and less costly.
Another objective of present invention is to provide a system for heating the intake charge of engine, which is safe to operate.
Yet another objective of present invention is to overcome all the challenges of existing prior art systems mentioned above.

SUMMARY OF INVENTION
With above objectives in view, the present invention provides a system for improving startability of an engine comprising:
an intake passage to supply intake charge to the engine through an intake port;
at least a heating element for heating the intake passage;
wherein the intake passage is provided with a provision for mounting the heating element;
Preferably, the mounting provision is such that the heated portion of the heating element is within the mounting provision and without being exposed directly to the intake charge.
The heating element is mounted in close proximity of the intake port.
According to an embodiment of the invention, outer surface of the intake passage is provided with an enclosure for mounting the heating element.
The heating element is configured to heat at least inner wall of the intake passage to heat the intake charge. The heated intake charge is further supplied to the engine through the intake port.
Preferably, the heating element is mounted at bottom part of the intake passage. According to another embodiment, the heating element is mounted at an angle of +/- 20 deg. to horizontal plane. This helps in improving accessibility and packaging. During operation, maximum quantity of the intake charge flows along the bottom surface of intake passage, hence providing heating element near bottom surface which helps in achieving effecting heating of the intake charge.
The operation of the heating element is initiated upon starting ignition of the vehicle and stopped upon fulfilling the predetermined condition/s of parameter/s including temperature of engine, oil or coolant reaching predefined threshold limit or after completion of predefined time limit. The temperature of any one or more of the parameter/s listed above is measured using sensor. The sensor input is fed into an electronic control unit (ECU), which compares the received temperature/s input with predefined threshold limit/s and start or stop the operation of the heating element.
Alternately, the operation of heating element may be initiated right from the starting of the ignition or the engine. The time lapsed after starting is measured by a timer circuit. Once the predefined time is over, the operation of heating element is automatically cut-off by the control unit.
There could be a combination of temperature sensing and timer circuit to decide start /stop the operation of heating element according to another embodiment of the invention.
According to another embodiment, the fuel is supplied in the intake passage using an injector. The injector is mounted near the heating element such that the injector is heated by the heating element. It helps in heating the fuel sprayed by fuel injector. The injector is mounted on the intake manifold or may be optionally mounted on the cylinder head. According to another embodiment, the fuel injector is mounted on upper side of the intake passage and the glow plug is mounted in close proximity of fuel injector on upper side of the intake passage. The glow plug is mounted such that the axis of glow plug forms an acute angle with the axis of fuel injector.
The fuel is sprayed such that the fuel is adhered to the heated inner wall of the intake passage and gets evaporated. The heated evaporated fuel is supplied to the engine through the intake port. Additionally, the fuel which is not adhered to the inner wall of the intake passage is also evaporated due to heat of inner walls of the intake passage.
According to another embodiment of the invention, the heating element is provided in the form of an electric heating element including a glow plug. The glow plug is supplied with electric power from battery for heating purpose. Preferably, one glow plug is used however; the additional heating element/glow plug may also be provided in the intake passage or outside intake passage or in combination thereof based on heating requirement. Other types of heating elements may also be used including heating plate or a light source.
The glow plug is mounted inside the enclosure provided in a cylindrical form on intake passage. Preferably, the glow plug is mounted and fixed in the enclosure using a threaded connection. An inner surface of the enclosure is provided with a tapered portion mating against an outer portion of the glow plug provided with corresponding opposite taper in order to achieve a sealing effect between both the portions, thereby preventing entry of any foreign particles into the enclosure.
The enclosure is provided with a drain hole, which acts as a breathing passage for the enclosure to prevent any excessive heating of air inside the enclosure. The drain hole further helps to remove moisture.
The enclosure may be provided in the form of a cavity or a chamber. Size and shape of enclosure may be suitably decided based on available space and shape of the heating element.
The provision of the heating element is made optional by making easy mounting and removal of the element within the enclosure. The heating element may be easily removed for engines, which doesn’t require heating of intake charge, the other system components may be used as it is without any modification. This makes system of the present invention modular.
According to another embodiment, the inner wall of intake passage or outer surface of fuel injector may be coated with a heat absorbing material, to help quick heating, which further assists in improving the effectiveness of system.
The intake charge is a pure fuel or a mixture of air and fuel. The fuel is any type of fuel including gasoline, Diesel, Compress Natural Gas (CNG), Liquid Petroleum Gas (LPG) or any ethanol fuel.
According to another embodiment, the system of present invention is applied in a single cylinder engine or any small capacity engine used in two wheeled, three wheeled or any four-wheeled vehicle. According to another embodiment of present invention, the engine is a multi-cylinder engine with plurality of intake passages connected together.
The summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF DRAWINGS
The invention will now be described in more detail by way of example with reference to the embodiments shown in the figures mentioned below:
Figure 1a illustrates a perspective view of a system for improving startability of an engine according to an embodiment of present invention;
Figure 1b illustrate a perspective view of the system for improving startability of the engine of the invention;
Figure 1c illustrate a perspective view of an intake passage with heating element used in the system for improving startability of engine of the invention;
Figure 2a illustrates a front view of the intake passage with mounting provision for the heating element used in the system for improving startability of the engine;
Figure 2b illustrates a sectional view of intake passage with the heating element used in the system for improving startability of engine;
Figure 3 illustrates sectional view of intake passage mounted with a system for improving startability of engine; and
Figure 4 illustrates a flow chart of different steps involved in operation of the system for improving the startability of the engine.

DETAILED DESCRIPTION OF DRAWINGS
Embodiments of present invention will now be explained with the help of figures herein below.
Fig. 1a-1c illustrating an engine (175) mounted with a system (100) according to an embodiment of present invention. The engine intake system comprises an intake passage 125 for supplying intake charge to the engine (175) through an intake port (128), wherein the intake charge comprises fuel, air or mixture thereof. The direction of flow of intake charge is indicated by an arrow (114). The intake passage (125) is mounted on the intake port (128) of the engine block. During operation of the engine (175), the intake charge is supplied through the intake passage (125) to the engine (175). The intake charge is further combusted inside the engine (175) to generate necessary power. In case of carburetted engines, a carburettor device (140) is installed in the intake passage (125) to prepare a mixture of air-fuel in a required proportion, which is further supplied to the engine (175). In case of engines with fuel injection system, an injector is provided in the intake passage (125) to inject a fuel (explained herein below).
A System for improving startability of the engine (175) comprises a heating element in the form of a glow plug (115). The glow plug (115) is mounted on the intake passage (125) near the intake port (128) of the engine (175). The glow plug (115) is configured to heat the intake passage (125), thereby heating the intake charge supplied to the engine (175). This helps in resolving the problem related to cold startability. The intake passage (125) is provided with an enclosure (110) on its outer surface for mounting the glow plug (115) into the enclosure (110). During operation, the glow plug (115) is heated using an electric power supplied by battery (not shown), which in turn heats the inner wall of the intake passage (125). Preferably, the glow plug (115) is mounted within a distance of 5mm to 50mm from the intake port (128), since it is observed to get maximum effectiveness when glow plug (115) mounted within this distance for the embodiment disclosed. This may vary depending upon type/capacity of the engine and layout of the intake system.
Referring to fig. 2a and 2b, illustrating further mounting details of the glow plug (115). A mounting provision (125a, 125b) is provided on the intake passage (125) for connecting the intake passage to the intake port (128) provided on the engine block through a bolted connection. The enclosure 110 for mounting the glow plug (115) is preferably provided on the bottom surface of the intake passage (125) in order to provide maximum heat to the bottom region. This helps in quickly heating the maximum quantity of the intake charge, since the maximum intake charge flows along the bottom part of intake port (128). According to another embodiment, the glow plug (115) is mounted at an angle of +/- 20 deg. to the horizontal plane. This helps in improving accessibility and packaging.
The heated glow plug tip (115a) may be kept at a distance of at least 4mm from the inner wall (125c) of the intake passage (125).This avoids any excessive heating of the enclosure and the intake passage and also, avoid possibility of explosion or fire, thereby improving safety of the vehicle. The enclosure 110 of the intake passage (125) such that the heated tip of glow plug (115a) is not exposed directly to the intake charge flowing through the intake passage (125). This avoids any possibility of explosion or fire caused due to heated glow plug coming in direct contact with the intake charge. Hence, the present system is safe to use. The thickness of walls of the intake passage (125) and material used may be decided suitably to further assist in quick heating of the intake passage (125). Preferably, Aluminium based alloy material may be used for manufacturing of intake passage.
Preferably, the glow plug (115) is mounted inside the enclosure (110) using a threaded connection (212). This also helps in easy removal of glow plug (115) for servicing or maintenance purpose. However, other type of mounting and fitting means are also possible.
An inner surface (110a) of the enclosure (110) is provided with a tapered portion mating against an outer portion (115b) of the glow plug (115) provided with corresponding opposite taper in order to achieve a sealing effect between both the portions, thereby preventing entry of any foreign particles into the enclosure (110).
A drain hole 260 is provided in the enclosure (110). This helps in removal of any moisture or water particles. The drain hole (260) also acts as a breathing passage for the enclosure (110), this helps in preventing trapping and excessive heating of air inside enclosure.
The enclosure (110) may be provided in the form of a cavity or a chamber. Size and shape of the enclosure (110) may be suitably decided based on available space and shape of the heating element.
More than one glow plugs may also be provided on or around the intake passage (125) in a similar manner based on the heating requirement.
Referring to Fig. 3, representing the heating system (100) useful for fuel injection (FI) type engines including diesel engines. The FI engines comprises a fuel injector (105) mounted on the intake passage (125) to spray predefined amount of fuel. The sprayed fuel is mixed with the air flowing through the intake passage (125) and thereafter supplied to the engine through intake port (128) for combustion.
Similar, to carburettor engine, the glow plug (115) is mounted within the enclosure (110) of intake passage (125). The fuel injector (105) and the glow plug (115) are closely mounted on the intake passage (125), this helps in quick heating of the fuel injector (105), thereby heating the fuel sprayed in intake passage (125). The heat generated by the glow plug further helps in heating of inner walls (125c) of the intake passage (125), thereby helping in quick heating of intake charge. The fuel sprayed by the fuel injector (105) adheres to the heated inner surface of intake passage (125), which helps in quick evaporation of intake charge.
According to another embodiment, the fuel injector (105) is mounted on upper side of the intake passage (125) and the glow plug (115) is mounted in close proximity of the fuel injector on upper side of the intake passage (125). This helps in quick heating of fuel sprayed by the fuel injector (105).
In order to achieve better heating effect, the glow plug (115) is mounted such that the axis of glow plug (115a) forms an acute angle with the axis of fuel injector (105a). According to another embodiment, the angle is kept approximately at 60 deg.
The glow plug (115) is mounted inside the enclosure (110) such that the heated tip of glow plug 115a is not exposed directly to the fuel sprayed by the fuel injector 105. The heated glow plug tip 115a is kept at a distance of atleast 4mm from the outer wall of intake passage 125. This avoids any excessive heating of intake passage and possibility of explosion or fire, thereby improving safety of the vehicle
In order to improve the effectiveness of heating the intake charge, a small hump portion (135) may be provided inside the intake passage (125) to make the surface of intake passage closer to the fuel injector (105).
The glow plug (115) is supplied with necessary electrical power from battery (not shown). The glow plug (115) is also connected with an electronic control unit (ECU) of the vehicle, which is configured to start or stop the operation of glow plug based on certain predefined condition/s.
Referring to fig. 4, illustrating a flow chart on working of the glow plug (115) according to another embodiment of present invention. During starting of the engine, as the ignition is turned ON at step (405), the temperature of engine surface or coolant or engine oil is sensed by a sensor (Not Shown) at step (415). More than one temperature may be sensed if needed. The sensed temperature is fed into the ECU of the vehicle for comparison with predefined threshold limit (415). If the sensed temperature is less than a predefined threshold limit, which is generally a case in cold starting, the glow plug (115) is turned ON at step (425). The sensor continuously monitors the temperature of engine surface or coolant or engine oil. The sensor input is fed into an electronic control unit (ECU). Once the sensed temperature exceeds predefined limit, ECU instructs to stop the operation of glow plug (115) at step (435).
Alternately, the glow plug may be turned for a certain fix duration after starting of the engine irrespective of other conditions. The glow plug may be turned ON right from the starting of ignition and the time lapsed is measured by a timer circuit. Once the predefined time is over, the operation of glow plug is automatically cut-off by the control unit.
Preferably, one glow plug is used however; the additional glow plugs may also be provided in the intake passage or outside intake passage based on heating requirement. Other types of heating elements may also be used including heating plate or a light source.
The provision of the heating element is made optional by making easy mounting and removal of heating element within enclosure. The heating element may be easily removed for engines, which doesn’t require heating of intake charge, the other system components may be used as it is without any modification. This makes system of present invention modular.
According to another embodiment, the inner wall (125c) of intake passage (125) or outer surface of fuel injector (105) may be coated with a heat absorbing material, to help quick heating, which further assists in improving the effectiveness of system.
The intake charge is a pure fuel or a mixture of air and fuel. The fuel is any type of fuel including gasoline, Diesel, Compress Natural Gas (CNG), Liquid Petroleum Gas (LPG) or any ethanol fuel having higher evaporation temperature.
Advantages of Present Invention:
In reference to above mentioned technical aspects and configuration, the present invention helps in achieving following advantages:
• A system helps in quick heating the intake charge of the engine, thereby achieving improved startability especially in cold conditions.
• The System of present invention is less complex, easy to manufacture and less costly.
• The present invention helps to provide a system for heating the intake charge of engine, which is safe to operate.
• The present invention helps to overcome all the challenges of existing prior art systems mentioned above.
According to another embodiment, the system of present invention is applied in a single cylinder engine or any small capacity engine used in two wheeled, three wheeled or any four-wheeled vehicle. According to another embodiment of present invention, the engine is a multi-cylinder engine with plurality of intake passages connected together.
Although the invention has been described with regard to its embodiments, specific embodiments, and various examples, which constitute the best mode presently known to the inventors, it should be understood that various changes and modifications as would be obvious to one having the ordinary skill in this art may be made without departing from the scope of the invention. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. All changes that come with meaning and range of equivalency of the claims are to be embraced within their scope.
,CLAIMS:CLAIMS
WE CLAIM:
1. A system for improving startability of an engine (175) comprising:
a. an intake passage (125) to supply intake charge to the engine (175) through an intake port (128);
b. at least a heating element (115) for heating the intake charge;
wherein the intake passage (125) is provided with a mounting provision (110) for the heating element (115) such that a heated portion (115a) of the heating element (115) is within the mounting provision (110) without being directly exposed to the intake charge.

2. The system for improving startability of an engine (175) as claimed in claim 1, wherein the heating element (115) is configured to heat the intake charge by heating at least inner wall (125c) of the intake passage (125).

3. The system for improving startability of an engine (175) as claimed in claim 1, wherein the heating element (115) is mounted in a close proximity of the intake port (128).

4. The system for improving startability of an engine (175) as claimed in claim 1, wherein the heating element (115) is mounted at bottom part of the intake passage (125).

5. The system for improving startability of an engine (175) as claimed in claim 1, wherein the heating element (115) is mounted at an angle of - 20 deg. to +20 deg. in a horizontal plane.

6. The system for improving startability of an engine (175) as claimed in claim 1, wherein the heating element (115) is operated upon starting ignition of the vehicle or engine (175) and stopped upon fulfilling the predetermined condition/s including temperature of engine (175), oil or coolant reaching predefined threshold limit/s or after completion of predefined time limit or in combination thereof.
7. The system for improving startability of an engine (175) as claimed in claim 6, wherein the temperature of the engine (175), oil or coolant measured using at least one sensor wherein the sensor input is fed into an electronic control unit (ECU) to compare the received temperature/s input with predefined threshold limit/s and start or stop the operation of the heating element (115) based on the comparison.

8. The system for improving startability of an engine (175) as claimed in claim 1, wherein the intake charge comprises a fuel that is injected in the intake passage (125) using an injector (105).

9. The system for improving startability of an engine (175) as claimed in claim 8, wherein the injector (105) mounted on the intake passage (125) or on the cylinder head near the heating element (115) such that the injector (105) is heated by the heating element (115).

10. The system for improving startability of an engine (175) as claimed in claim 8, wherein the heating element (115) is mounted such that an axis of the heating element (115) forms an acute angle with an axis of the fuel injector (105).

11. The system for improving startability of an engine (175) as claimed in claim 1, wherein the heating element (115) is provided in the form of an electric heating element (115) including a glow plug or a light source wherein, the heating element (115) is supplied with electric power from a battery for heating purpose.

12. The system for improving startability of an engine (175) as claimed in any one of the claim above, wherein the system comprises plurality of electric heating elements (115) mounted on the intake passage (125) or outside intake passage (125) or in combination thereof based on heating requirement.

13. The system for improving startability of an engine (175) as claimed in claim 1, wherein the mounting provision (110) is in the form of a cavity or a chamber providing an enclosure for mounting the heating element (115).

14. The system for improving startability of an engine (175) as claimed in claim 13, wherein the enclosure (110) is provided with a threading for mounting and removably fixing the heating element (115) in the enclosure (110).

15. The system for improving startability of an engine (175) as claimed in claim 13, wherein the enclosure (110) is provided with an inner surface having a tapered portion mating against an outer portion of the heating element (115) provided with corresponding opposite taper in order to achieve a sealing effect between both the portions; and the enclosure (110) is provided with a drain hole to act as a breathing passage for the enclosure (110) to prevent any excessive heating of air inside the enclosure (110) or to remove moisture.

16. The system for improving startability of an engine (175) as claimed in claim 13, wherein the heated portion of the heating element (115a) is at a distance of at least 4mm from the inner wall (125c) of the intake passage (125).

17. The system for improving startability of an engine (175) as claimed in claim 1, wherein an inner wall (125c) of the intake passage (125) or an outer surface of a fuel injector (105) coated with a heat absorbing material to assist in quick heating.

18. The system for improving startability of an engine (175) as claimed in claim 1, wherein the intake charge is a pure fuel or a mixture of air and fuel wherein, the fuel is any type of fuel including gasoline, Diesel, Compress Natural Gas (CNG), Liquid Petroleum Gas (LPG) or any ethanol based fuel.

19. The system for improving startability of an engine (175) as claimed in claim 1, wherein the engine (175) is a single cylinder engine (175) or any small capacity engine (175) used in a two-wheeled, three-wheeled or any four-wheeled vehicle.

20. The system for improving startability of an engine (175) as claimed in claim 1, wherein the engine (175) is a multi-cylinder engine (175) with plurality of intake passages connected together.