FILL LIMIT VENT VALVE FOR FUEL TANK

Abstract

It is disclosed a FLVV including: an upper cover provided in the fuel tank, and having an outlet duct; a casing coupled to the upper cover; the float, which is elastically provided inside the casing so as to be movable upward and downward, has a first valve seat provided on the upper surface of one side thereof so as to open and close a first outlet port by principle of a lever, and has a recessed surface formed at one side of the upper surface thereof; the plate elastically provided by a second spring at the recessed surface formed at the float, so as to open and close a second outlet port while moving upward and downward; and a lower cover closing the lower part of the casing and having the float elastically provided by a first spring.

Claims

1. A fill limit vent valve (FLVV) for a fuel tank, the FLVV comprising: an upper cover provided in the fuel tank and having an outlet duct, a casing coupled to the upper cover, a float which is elastically provided inside the casing so as to be movable upward and downward, has a first valve seat provided on an upper surface of one side thereof so as to open and close a first outlet port by principle of a lever, and has a recessed surface formed at one side of the upper surface thereof, a plate elastically provided by a second spring at the recessed surface formed at the float, so as to open and close a second outlet port while moving upward and downward, and a lower cover closing a lower part of the casing and having the float elastically provided by a first spring.

2. The FLVV of claim 1, wherein an insertion hole for assembling a first valve seat is formed at the lever of the float, and a projection to be inserted into the insertion hole by interference fit is formed at the first valve seat.

3. The FLVV of claim 1, wherein a receiving space is formed at an upper part of the first outlet port formed at the casing, and a third valve seat having a fine through-hole is elastically provided by a third spring inside the receiving space and also supported by a cap.

4. The FLVV of claim 1, wherein the recessed surface formed at the float has a half-moon shape, and the plate provided at the recessed surface to move upward and downward also has a half-moon shape.

5. The FLVV of claim 1, wherein a division wall having a vertical slit is formed at an outer side of the recessed surface formed at the float, and an outward protrusion to be inserted into the vertical slit is formed at the plate.

6. The FLVV of claim 1, wherein a guide protrusion is formed at the recessed surface of the float so as to protrude upward, and a vertical through-hole into which the guide protrusion is inserted is formed at the plate.

7. The FLVV of claim 1, wherein two or more vertical projections are formed at an inner surface of the lower cover, and vertical rails into which the vertical projections are inserted are formed at an outer circumferential surface of the float.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0042] FIGS. 1A and 1B are longitudinal cross-sectional views illustrating an existing fill limit vent valve (FLVV).

[0043] FIG. 2 is a cross-sectional view taken along a line A-A of FIG. 1A.

[0044] FIG. 3 is an exploded perspective view illustrating a configuration of the present invention.

[0045] FIG. 4 is a longitudinal cross-sectional view illustrating an assembling state of FIG. 3.

[0046] FIG. 5 is a perspective view illustrating a casing being decoupled from a lower cap of the present invention.

[0047] FIG. 6 is a top view of FIG. 5.

[0048] FIGS. 7A through 7C are perspective views with partial cross-sections illustrating an operation state of the present invention,

[0049] FIG. 7A illustrating a state of feeding fuel with first and second outlet ports being all opened,

[0050] FIG. 7B illustrating a state of being full of the fuel with the first outlet port being opened and the second outlet port being closed, and

[0051] FIG. 7C illustrating a state of closing the first outlet port by a first valve seat in response to sloshing of the fuel.

BEST MODE FOR CARRYING OUT THE INVENTION

[0052] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, such that those having ordinary skill in the art to which the present invention pertains may easily practice the present invention. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. It is noted that the drawings are schematic, and are not illustrated based on actual scales. Relative dimensions and proportions of parts illustrated in the drawings are exaggerated or reduced in size for the purpose of clarity and convenience in the drawings, and any dimension is just illustrative but not restrictive. Further, the same reference numerals designate the same structures, elements or components illustrated in two or more drawings in order to exhibit similar characteristics.

[0053] FIG. 3 is an exploded perspective view illustrating a configuration of the present invention, FIG. 4 is a longitudinal cross-sectional view illustrating an assembling state of FIG. 3, and FIG. 5 is a perspective view illustrating a casing being decoupled from a lower cap of the present invention, wherein an upper cover 100 having an outlet duct 101 is provided in a fuel tank (not shown), a float 120 having a recessed surface 121 on one side thereof is elastically provided by a first spring 122 inside a casing 110 coupled to the upper cover 100 so as to be movable upward and downward, and a lower part of the casing 110 is closed by a lower cap 130.

[0054] First and second outlet ports 111 and 112 are formed on a top of the casing 110 provided between the upper and lower caps 100 and 130, wherein the first outlet port 111 is configured to be opened and closed by the first valve seat 111 when the float 120 moves upward and downward, and the second outlet port 112 is configured to be opened and closed by a second valve seat 141 when a plate 140 moves upward and downward.

[0055] The present invention is directed to forming the recessed surface 121 in a half-moon shape at one side of the upper part of the float 120 elastically provided by the first spring 122 and providing the plate 140 having the second valve seat 141 in an assay shape at the recessed surface 121, thereby enabling the float 120 and the plate 140 to move upward and downward simultaneously, or enabling only the plate 140 to independently move upward and downward.

[0056] To this end, as shown in FIG. 5, a division wall 114 having a vertical slit 114a is formed at an outer side of the recessed surface 121 of the float 120, and an outward protrusion 143 to be inserted into the vertical slit 114a is formed at the plate 140, such that when the float 120 moves downward, the plate 140 also moves downward.

[0057] Further, for stable upward and downward movements in response to the plate 140 moving upward and downward, a guide protrusion 123 is formed at the recessed surface 121 of the float 120 so as to protrude upward, and a vertical through-hole 145 into which the guide protrusion 123 is inserted is formed at the plate 140 such that the plate 140 does not move laterally when the plate 140 moves upward and downward.

[0058] In addition, for stable upward and downward movements of the float 120, as shown in FIG. 6, two or more vertical projections 131 are formed at an inner surface of the lower cover 130, and vertical rails 124 into which the vertical projections 131 are inserted are formed at an outer circumferential surface of the float 120.

[0059] A first valve seat 113 is provided on an upper surface of one side of the float 120 so as to open and close the first outlet port 111 by principle of a lever 115, and a hinge 115a to be rotatably coupled to a top surface of the float 120 is formed at one end of the lever 115.

[0060] An insertion hole 115b for assembling the first valve seat 113 is formed at the lever 115, and a projection 113a to be inserted into the insertion hole 115b by interference fit is formed at the valve seat 113.

[0061] Meanwhile, a receiving space 116 is formed at an upper part of the first outlet port 111 formed at the casing 110, and a third valve seat 117 having a fine through-hole (not shown) is elastically provided by a third spring 118 inside the receiving space 116 and also supported by a cap 119.

[0062] This is to adjust an amount of additional fuel to be automatically additionally fed by adjusting an elasticity coefficient of the third spring 118.

[0063] In the drawings, the reference numeral 150 not described denotes an O-ring for maintaining an airtightness between the upper cover 100 and the casing 110.

[0064] An action of the present invention is described below.

[0065] First, as shown in FIG. 7A, when the fuel within the fuel tank is exhausted, the float 120 moves downward to a bottom dead center by its self-weight. In this example, since the vertical rails 124 are formed at the outer circumferential surface of the float 120 and the vertical projections 131 to be inserted into the vertical rails 124 are formed at the lower cover 130, the float 120 stably moves downward.

[0066] In addition, since the outward protrusion 143 of the plate 140 is inserted into the vertical slit 114a of the float 120, the plate 140 is displaced at the bottom dead center along with the float 120 such the first and second outlet ports 111 and 112 are opened at the same time.

[0067] As described above, when the float 120 moves downward, the first valve seat 113 opens the first outlet port 111 with a relatively less force since the length of the lever 115 provided at the upper part of the float 120 is far greater than that of the existing valve.

[0068] Furthermore, the plate 140 provided at the recessed surface 121 of the float 120 so as to be movable upward and downward does not move laterally by the guide protrusion 123 and the vertical through-hole 145 and thus, stably moves downward.

[0069] As described above, in a state in which the plate 140 is displaced at the bottom dead center along with the float 120 and the first and second outlet ports 111 and 112 are all opened, fuel filling is possible.

[0070] Accordingly, when a driver starts fuel filling with a nozzle (not shown) of a lubricator inserted into a filling hole, the fuel tank is filled with fuel and the plate 140 gradually moves upward, wherein the plate 140 stably moves upward without moving laterally by the two rail structures as described above and closes the second outlet port 112 as shown in FIG. 7B. Thus, fuel filling is not possible any further, but the pressure within the fuel tank is adjustable since the float 120 opens the first outlet port 111.

[0071] As described above, FIG. 7B illustrates a state in which fuel filling is completed and the vehicle is ready to travel. When the fuel within the fuel tank sloshes due to pathholes on a road or sudden braking during travelling and the float 120 moves upward as shown in FIG. 7C, the first valve seat 113 provided at the top part of the float 120 moves upward by a restoring force of the first spring 122 and quickly closes the first outlet port 111, thus a discharge of the fuel through the first outlet port 111 is prevented.

[0072] Meanwhile, when the travelling is continued and stabilized, the float 120 having risen in response to the sloshing of the fuel returns to its initial position as shown in FIG. 7B, and the first valve seat 113 closing the first outlet port 111 moves downward by the lever 115 and opens the first outlet port 111. Thus, evaporative gas of a predetermined or higher pressure is discharged through the outlet duct 101, whereby the internal pressure of the fuel tank is maintained at a preset level.

[0073] Even though embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art may understand that the embodiments may be implemented in other specific embodiments without changing the technical spirit or essential features.

[0074] Accordingly, the aforementioned embodiments are only examples in every aspect and thus, are to be understood not to be limitative. The range of the present invention is to be defined by the claims rather than by the detailed description. All of the modifications or modified forms induced from the meaning and range of the claims and the equivalents thereof are to be interpreted to be included within the scope of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

[0075] 11: Casing [0076] 100: Upper cover [0077] 101: Outlet duct [0078] 111: First outlet port [0079] 112: Second outlet port [0080] 113: First valve seat [0081] 115: Lever [0082] 117: Third valve seat [0083] 120: Float [0084] 121: Recessed surface [0085] 122: First spring [0086] 123: Guide protrusion [0087] 124: Vertical rail [0088] 130: Lower cover [0089] 131: Vertical projection [0090] 140: Plate [0091] 141: Second valve seat [0092] 142: Second spring [0093] 143: Outward protrusion [0094] 145: Vertical through-hole