FIELD OF INVENTION

The present invention relates to a system for evaporative emission control in automotive two wheelers using a rollover valve for automotive two wheeler applications. More particularly, the present invention relates to a rollover valve with a slider mechanism to cut off the fuel supply to a canister and thereby preventing it from flooding, when the vehicle gets tilted to pre-defined angle.

DESCRIPTION OF PRIOR ART

Under the influence of ambient temperature petrol turns into hydrocarbon gas and evaporates in the air before entering the engine for ignition. In automobile industry, many of the internal combustion engines generate approximately 20% of their hydrocarbon emissions by evaporative process. As most hydrocarbons are harmful to human health, the government has legislated to restrict the amount of hydrocarbon emission by passenger cars, buses and motorcycle. The evaporative emission control norms for automotive industry are strict due to global warming. All automotive Original Equipment Manufacturer (OEM's) working in this direction need to meet the norms laid down by the government.

Many apparatuses are used in automobiles industry to reduce hydrocarbon emissions from a fuel system of automobiles. Evaporative emissions control (EVAP) system is typically implemented to store and subsequently dispose of fuel vapor emissions to prevent fuel vapor from escaping to the atmosphere. Rollover valve is one such equipment used in evaporative emission control system. The rollover valve is connected in between fuel tank and canister. The evaporated fuel vapors are collected by fuel vapor separator and pass through a tube which is connected to canister. The canister contains activated carbon which stores this fuel vapor and until the engine gets started, the fuel vapors are stored in the canister. During operation the rollover valve is open and it passes the fuel vapors from the fuel tank to the canister. During working when vehicle is titled to a pre-defined angle, the roller valve cuts off the fuel supply to the canister and prevents the canister from flooding. In the existing rollover valve a steel ball is used to close the valve when the vehicle is titled to a pre-defined angle so that evaporative emission is controlled. In steel ball mechanism, the steel ball seating is a line contact type which is highly unstable under vehicle condition.

298/CHE/2011 discloses a rollover valve that includes a weight portion and a valve member in housing. The weight portion is heavier than the valve member. The valve member has a first face opposing to a first end in an axis direction of the housing, and the weight portion has a second face opposing to a second end in the axis direction. The second face is located adjacent to the first end than the first face. The first face and the second face are engaged with each other when the valve member is separated from a valve seat defined on an inner face of the housing. US20140116537 discloses a fuel cutoff valve that opens and closes a connection conduit connecting a fuel tank and the outside. The fuel cutoff valve comprises a casing that includes a primary valve chamber connected to the connection conduit, and a secondary valve chamber disposed under the primary valve chamber; a primary valve mechanism that is housed in the primary valve chamber and rises and falls according to a fuel level in the primary valve chamber; and a secondary valve mechanism that is housed in the secondary valve chamber and rises and falls according to a fuel level in the secondary valve chamber.

US7571740 discloses a cut off valve that opens and closes a connection conduit for connecting a tank to a location exterior to the tank. The cut off valve comprising a casing that includes a valve chamber that is constructed and arranged to connect the fuel tank to the connection conduit, a float mechanism that is accommodated in the valve chamber to open and close the connection conduit according to a level of a liquid fuel in the fuel tank and a spring that presses the float mechanism in a closing direction. Therefore, there is demand for a rollover valve which is more stable under different vehicle condition. .

OBJECTS OF INVENTION

One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention. It is the primary object of the present invention to provide a rollover valve with a slider mechanism to cut off the fuel supply to a canister and thereby preventing it from flooding, when the vehicle gets tilted to a pre-defined angle, said rollover valve is connected in between the fuel tank and the canister of the vehicle. It is another object of the present invention, wherein the slider is made of metallic material, preferably stainless steel.

It is another object of the present invention, wherein weight of the slider is greater than the force exerted by the fuel.

It is another object of the present invention, wherein the rollover valve working is based on the principle of shifting of weight due to center of gravity.

SUMMARY OF INVENTION Thus according to the basic aspect of the present invention there is provided a rollover valve with slider mechanism comprising of:

a housing-bottom;

a slider;

a cup; and

a housing-top,

wherein the slider and the cup are positioned one over the other and retained in position within the housing-bottom and housing-top, and

wherein when the vehicle fitted with the rollover valve gets tilted beyond pre-defined angle with reference to datum plane, the slider falls on the cup and pushes the cup towards the housing-top, there by the fuel supply to canister is cut off.

According to another aspect of the invention the housing-bottom comprises a profiled portion, a cylindrical stepped portion and an outlet portion. According to another aspect of the invention the slider comprises a profiled bottom portion matching the profile of the profiled portion of the housing-bottom and a generally flat upper portion.

According to another aspect of the invention the cup comprises a cylindrical shell portion with an open bottom and a closed top having an upwardly protruding nipple portion which is arranged co axial to the closed top.

According to another aspect of the invention the housing-top comprises a cylindrical shell portion defining an inside wall portion having a valve opening to accommodate the nipple portion of the cup, an outside wall portion and an inlet portion.

According to another aspect of the invention the slider and the cup are positioned one over the other within the housing-bottom and closed by upper housing- top and permanently integrated. According to another aspect of the invention the slider fall on the cup positioned in the rollover valve when centre of gravity of slider falls outside of the slider base.

According to another aspect of the invention when the angle of tilt is restored to 0°, the slider returns to its stable or original position.

According to another aspect of the invention the contact between the slider and housing-bottom is area contact type which makes the rollover valve stable under normal working condition of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 : schematically illustrates the cross sectional front view of the rollover valve according to the present invention, shown in valve opened condition.

Figure 2: schematically illustrates the cross sectional front view of the housing-bottom of the rollover valve according to the present invention.

Figure 3: schematically illustrates the front view of the slider of the rollover valve according to the present invention. Figures 4: schematically illustrates the cross sectional front view of the cup of the rollover valve according to the present invention.

Figures 5: schematically illustrates the cross sectional front view of the housing-top of the rollover valve according to the present invention.

Figures 6: schematically illustrates the rollover valve with a carburetor system shown during normal working of the vehicle.

Figures 7: schematically illustrates the position of the slider fitted to the rollover valve according to the present invention corresponding to different tilt angle of the vehicle.

Figures 8: schematically illustrates the rollover valve according to the present invention with a carburetor system when the vehicle is titled to more than pre-defined angle.

Figures 9: schematically illustrates the cross sectional front view of the rollover valve according to the present invention, shown in valve opened condition.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

The present invention as discussed hereinbefore relates to a rollover valve with a slider mechanism to cut off the fuel vapor supply to a canister and thereby preventing it from flooding, when the vehicle gets tilted to a pre-defined angle and above.

Referring to Figure 1, the rollover valve [5] with slider mechanism comprises a housing-bottom [1], a slider [2], a cup [3] and a housing-top [4]. Preferably the housing-bottom [1], the cup [3] and the housing-top [4] are made of wear resistant high impact thermoplastic material and are injection molded. The slider [2] is made of wear resistant metal, preferably stainless steel.

As shown in Figure 2, the housing-bottom [1] comprises a profiled portion [la], a cylindrical stepped portion [lb] and an outlet portion [lc] for connecting the fuel vapor tube. As shown in Figure 3, the slider [2] comprises a profiled bottom portion [2a] matching the profile of the profiled portion [la] of the housing-bottom [1] and a generally flat upper portion [2b]. As shown in Figure 4, the cup [3] comprises a cylindrical shell portion with an open bottom [3 a] and a closed top [3b] having an upwardly protruding arranged nipple portion [3c] which is arranged co axial to the closed top [3b]. As shown in Figure5, the upper housing-top [4] comprises a cylindrical shell portion defining an inside wall portion [4a] having a valve opening [4b] to accommodate the nipple portion [3 c] of the cup [3], an outside wall portion [4c], an inlet portion [4d ] disposed for connecting the fuel vapor tube and open bottom portion [4e]. The slider [2] and the cup [3] are positioned one over the other and retained in position by the profiled portion [la] of the housing-bottom [1] such that on falling, the nipple portion [3c] of the cup [3] is getting seated within the valve opening [4b] of the housing- top [4]. The housing-top [4] and the housing-bottom [1] comprising the slider [2] and the cup [3] is joined with the help of the cylindrical stepped portion [lb] of the housing-bottom [1] and the open bottom portion [4e] of the of the housing-top [4] and permanently integrated in any one of the known methods, for example by ultra sonic welding. The assembly of the roller valve [5] is such that the inlet portion [4d ] of the of the upper housing[4] and the outlet portion [lc] of the housing-bottom [1] are approximately 180° apart for providing unrestricted degrees of freedom for the slider [2] and the cup [3] as shown in Figure 1.

The rollover valve [5] is connected in between a fuel tank and canister of the vehicle.

The slider [2] positioned in the rollover valve [5] works based on the principle of shifting of weight due to center of gravity. The slider [2] fall on the cup [3] positioned in the rollover valve

[5] when centre of gravity of slider falls outside of the slider [2] base.

When the vehicle fitted with the roll over valve [5] is titled to a pre-defined angle with reference to datum plane as shown in Figure 7, the slider [2] becomes unstable when the center of gravity of the slider [2] falls outside of its base. Due to the above the profiled bottom portion [2a] of the slider [2] slides over the profiled portion [la] of the housing-bottom [1] and falls on the cup [3] and pushes the cup such that its nipple portion [3c] closes the valve opening [4d] of the housing- top [4] as shown in Figures 8 and 9, there by the fuel to the canister is cut off and flooding of the canister is prevented.

When the angle of tilt is restored with reference to datum plane, the slider [2] returns to its stable or original position as shown in Figures 1 and 6 and fuel vapor supply to the canister is resumed. As shown in figure 7, when the vehicle is titled in the pre-specified angle range with reference to datum plane, seating face of the slider [2] is parallel to the datum plane.

The slider [2] and the cup [3] are constructed such that both of them have unrestricted degrees of freedom. Contact between the slider [2] and the housing-bottom [1] is area contact type which makes the rollover valve [5] stable under normal working condition of the vehicle.

The present invention is explained with an embodiment wherein the rollover valve will shut the fuel to the canister when the vehicle is tilted to 60° and above. However it is to be under stood that it is possible to practice this invention to shut the fuel to the canister when the vehicle is tilted to any other pre defined angle of tilt by suitably configuring the elements of the rollover valve.