DESC:Field of the invention

The present invention relates generally to carbon canisters and more particularly, to a liquid trap for a carbon canister that is fitted inside the carbon canister by a snap lock.

Background of the invention

A carbon canister is used to trap and adsorb fuel vapor emissions from the fuel tank of a vehicle. It is part of the evaporative emission control system and used to reduce air pollution. It becomes necessary to trap the hydrocarbons inside the fuel tank as temperature variations cause the fuel to evaporate. At the same time, it is of vital importance to provide adequate venting to the fuel tank to keep it safe against temperature variations. A venting arrangement that leads to the carbon canister is currently being deployed in vehicles. The carbon canister collects and stores the hydrocarbons. There is also a provision for storing liquid fuel that sometimes gets condensed.

Currently, the carbon canisters come with liquid traps that are welded to an outer surface of the canister. However, this arrangement leads to time-consuming additional processes during vehicle assembly as well as increases costs. Further, the attachment of the liquid traps outside the carbon canister sometimes may lead to packaging issues and require man power cost. Furthermore, the external attachment of the liquid trap causes space constraint with surrounding parts in the vehicle and also requires more time to design liquid trap capacity considering the surrounding parts. Moreover, the liquid traps that are welded to the outside of the carbon canister requires more time to vaporize the liquid fuel.

Therefore, there exists a need to provide a common liquid trap that is suitable for use with other canisters and fitted inside the carbon canister to provide more clearances from surrounding parts during assembly in the vehicle. Accordingly, there exists a need for a liquid trap fitted inside the carbon canister with a less complex process of assembly that is cost-effective, reduces rejection cost, time and cost of the equipment/fixture, and resolves packaging issues.

Objects of the invention

An object of the present invention is to provide a snap lock type liquid trap that is fitted inside a carbon canister.

Another object of the present invention is to provide a mechanism that results in easy assembly and a less complex process for packaging resulting in cost-effectiveness.

Yet another object of the present invention is to provide more clearances from surrounding parts during assembly in a vehicle.

Still another object of the present invention is to provide an ease of assembly with a snap lock feature by eliminating the vibration/hot/spin welding process and thereby reducing the assembly cost, rejection cost, time and cost of the equipment/fixture.

One more object of the present invention is to provide a common liquid trap that is suitable for use with other canisters.

Summary of the invention

Accordingly, the present invention provides a liquid trap for a carbon canister. The liquid trap includes a mesh configured on an outer surface of a housing, and a snap lock configured on an outer periphery of the housing. The mesh facilitates ventilation during adsorption. The mesh is made of anyone of nylon, polypropylene, and hydrophobic material. The snap lock facilitates the attachment of the liquid trap with an inner surface of the carbon canister manually. In accordance with the present invention, the liquid trap is manufactured using a plastic molding process. The present invention provides an ease of assembly with the snap lock feature by eliminating the vibration/hot/spin welding process and thereby reducing the assembly cost, rejection cost, time and cost of the equipment/fixture.

Brief description of the drawings

The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows a carbon canister, in accordance with the present invention;

Figure 2 is an exploded view showing all components of the carbon canister, in accordance with an embodiment of the present invention; and

Figures 3a-3b show a liquid trap for the carbon canister, in accordance with an embodiment of the present invention.

Detailed description of the invention

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

The present invention provides a liquid trap for a carbon canister. The liquid trap is configured to fit inside the canister using a snap lock. The liquid trap fitted inside the carbon canister provides more clearances from surrounding parts during assembly in a vehicle. The present invention provides a common liquid trap that is suitable for use with other canisters.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in brackets in the following description and in the table below:
Ref. No. Component Name Ref. No. Component Name
10 Case 50 Top filters
20 Bottom cover 60 Bottom filter
30 Compression plate/ grid 70 Spring
32 Housing of liquid trap 80 Activated carbon
34 Mesh of liquid trap 90 Vent cap
36 Snap lock 100 Carbon canister
40 Liquid trap

Referring to figures 1-2, a carbon canister (100) in accordance with the present invention is shown. The carbon canister (100) comprises a case (10), a bottom cover (20), a compression plate/grid (30), a liquid trap (40), top filters (50), a bottom filter (60), one or more springs (70), an activated carbon (80), and a vent cap (90). The case (10) with the bottom cover (20) is configured to enclose the rest of the constituent components of the carbon canister (100) such as the activated carbon (80) and the liquid trap (40). The spring (70) is configured to keep the activated carbon (80) in compact condition. The activated carbon (80) adsorbs and desorbs the hydrocarbons in fuel vapors. The top filters (50) and the bottom filter (60) are configured to provide ventilation during adsorption and desorption and hold the activated carbon granules without leaking. The vent cap (90) is configured to prevent the entry of foreign materials such as dust, mud, and water inside the carbon canister (100) and provide ventilation during adsorption and desorption.

As shown in figures 3a-3b, the liquid trap (40) includes a housing (32), a mesh (34) and a snap lock (36). The mesh (34) is configured on an outer surface of the housing (32) and facilitates ventilation during adsorption. In an embodiment, the mesh (34) is made of materials such as nylon, and polypropylene. Alternatively, the mesh (34) can be made from hydrophobic material and may be of size in the range of 2µ to 10µ.

The snap lock (36) is configured on an outer periphery of the housing (32) as shown in figure 3b. The snap lock (36) facilitates the attachment of the liquid trap (40) with an inner surface of the carbon canister (100) manually and does not require machine assistance.

In an embodiment, the liquid trap (40) is manufactured using a plastic molding process and is configured to fit inside the carbon canister (100). In an exemplary embodiment of the present invention, the liquid trap (40) may have a capacity in the range of 5ml to 50ml.

In accordance with the present invention, the liquid trap (40) stores the condensed fuel vapors in liquid form and avoids entry thereof in the carbon canister (100). When liquid fuel enters the liquid trap (40), heat is produced by the activated carbon (80), which causes the fuel to evaporate, and the vapors are adsorbed on the activated carbon (80). Thus. the liquid trap (40) is configured such that the heat that gets generated inside the carbon canister (100) during adsorption causes the liquid fuel to evaporate immediately and vapors get adsorbed on to the activated carbon (80). The liquid trap (40) is configured to fit within the carbon canister (100) such that the arrangement prevents fouling of other parts of the vehicle.

Advantages of the invention

1. The liquid trap (40) fitted inside the carbon canister (100) facilitates optimization in the assembly process as well as cost.
2. The snap lock type liquid trap (40) is made from a plastic molding process and hence can be manufactured in less time on a mass scale.
3. The liquid trap (40) fitted inside the carbon canister (100) improves the vehicle performance, efficiency, reliability and durability.
4. Being fitted inside the carbon canister (100), the liquid trap (40) is invisible and has more clearances from surrounding parts in the vehicle.
5. The liquid trap (40) has increased liquid trap capacity/ efficiency and the same liquid trap may be used for other canisters as the components are reusable.
6. The present invention provides an ease of assembly with the snap lock (36) feature by eliminating the vibration/hot/spin welding process and thereby reducing the assembly cost, rejection cost, time and cost of the equipment/fixture.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention. ,CLAIMS:We claim:
1. A liquid trap (40) for a carbon canister (100), the liquid trap (40) comprising:
a mesh (34) configured on an outer surface of a housing (32) for facilitating ventilation during adsorption; and
a snap lock (36) configured on an outer periphery of the housing (32), the snap lock (36) facilitating the attachment of the liquid trap (40) with an inner surface of the carbon canister (100) manually.

2. The liquid trap (40) as claimed in claim 1, wherein the mesh (34) is made of anyone of nylon, polypropylene, and hydrophobic material.

3. The liquid trap (40) as claimed in claim 1 is manufactured using a plastic molding process.