Internal carburetor purging device and method of use thereof

Abstract

An attachment for purging the inside of the carburetors which is comprised by a tubular device having a carburetor connecting member and quick connect receiver extension. The attachment is connected through the bottom of the carburetor or through the feed fuel line of the carburetor. The attachment is attachable to a quick disconnect fitting which can be connected to a conventional car tire air nozzle or pressurized can with the same fitting as the car tire nozzle. The attachment allows all the jets and passages located on the inside of carburetor to be purged at the same time with multiple short blasts of compressed air or pressurized can solvent but without the carburetor being removed from the engine or taken a part. The same principles can easily be applied to all type carburetors for either a two or four-stroke engine.

Claims

1. A method of purging the inside of a carburetor comprising; a. attaching a permanent carburetor attachment device with one end threaded for clockwise turn into a threaded receiver inside the carburetor; b. attaching a second end of the attachment device with a receiving extension with quick connect one-way pneumatic tire valve to a compressed air source; c. influencing the flow of compressed air with a flow limiting orifice in the attachment device in series with the quick connect one-way pneumatic tire valve inside the attachment device that has an open channel to the carburetor through the threaded end of attachment device; d. to use, a fuel shut off valve on the carburetor as a receiving port for the attachment device is closed; e. purging starts when compressed air or pressurized solvent is delivered through the attachment device quick connect one-way pneumatic tire valve into the carburetor; f. the source of compressed air or pressurized solvent has the same fittings as a conventional car tire air nozzle; g. purging continues with multiple short blasts of compressed air or pressurized solvent sent through the attachment device into the carburetor.

2. The method of claim 1 wherein the attachment device is not permanent.

3. The method of claim 1 wherein the attachment devices connect to a fuel feed line port.

4. The method of claim 1 wherein a permanently installed shut off two-way valve is attached to the fuel feed line with attachment device installed into one port of the two-way valve.

5. The method of claim 1 wherein a permanently installed shut off three-way valve is attached to the fuel feed line with attachment device installed in one port of the three-way valve.

6. The method of claim 1 wherein a permanently installed shut off check valve is attached to the fuel feed line with a pneumatic one-way valve installed upstream of the check valve.

7. The method of claim 1 wherein a tee fitting is placed within the fuel feed hose with the one-way pneumatic valve installed upstream of the tee fitting.

8. The method of claim 1 wherein a pressurized can is equipped with a release valve and a hose and tire inflator nozzle head wherein the pressurized can's tire inflator nozzle is attached to fuel shut off valve on the carburetor instead of the quick connect one-way pneumatic tire valve inside the attachment device.

9. The method of claim 1 wherein a carburetor bowl fuel drain plug is left off while compressed air or pressurized solvent is delivered to the carburetor.

10. The method of claim 1 wherein fuel is drained from the carburetor through the attachment device once the one-way pneumatic valve is removed.

11. The method of claim 8 wherein the pressurized can is filled with Halocarbon 152A (R-152a), Hydrofluorocarbon-134a (R-134a), propane, butane gas or any other gases or mixture of gases and liquids.

12. The method of claim 8 wherein the contents of the pressurized can are mixed with an anti-corrosive additive.

13. The method of claim 8 wherein a small amount of mineral oil is mixed in with the contents of the pressurized can.

14. The method of claim 1 wherein a diaphragm type carburetor primer bulb is manually activated to establish initial pressurized gas flow.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is exploded view of a typical float type small engine carburetor used in power equipment like lawn mowers, snow blowers, pressure washers, generators, etc. The main parts of the carburetor are carburetor body 1 and carburetor bowl 11.

(2) FIG. 2a shows the carburetor bowl retaining screw 10 is removed prior to purging.

(3) FIG. 2b shows the purge valve 43 placement into where the location of carburetor bowl retaining valve.

(4) FIG. 3a shows cross section of the divided (extended with a hose) one-way pneumatic purge valve (Schrader type) for the power equipment machinery carburetors.

(5) FIG. 3b shows a better view how the clamp 49, holds the valve core 41 in the assembly.

(6) FIG. 3c shows how the sub-components of the purge valve 43 fit together, the sub-components being the cylindrical metal tube 40, the valve core 41 and the valve cap 43.

(7) FIG. 4a shows carburetor main jet and emulsion tube cross section with the purge valve and air nozzle before the assembly.

(8) FIG. 4b shows carburetor main jet, emulsion tube, purge valve and air nozzle cross section after the assembly.

(9) FIG. 4c shows exploded view of the pressurized can parts

(10) FIG. 5a shows pressurized can connected to the carburetor through an air nozzle and a purge valve

(11) FIG. 5b shows carburetor connection to an air compressor.

(12) FIG. 5c shows pressurized can connected to the carburetor mounted on an engine.

(13) FIG. 5d shows and describes how to install the purge valve and how to purge the carburetor.

(14) FIG. 6a is a cross section of the carburetor with the installed purge valve and attached air into the carburetor bowl cavity showing the carburetor drain plug opening 95.

(15) FIG. 6b is a top view of the carburetor showing the fuel delivery port 7, the fuel filter 18, the bowl vent 73, and the needle valve sit 76.

(16) FIG. 6b is a 3.4 top view showing in addition to FIG. 6c, the fuel shut-off valve 16, the carburetor vent port 74 and the inner face of the carburetor body 75.

(17) FIG. 7a and FIG. 7b is a cross section of the carburetor installed purge valve and attached air nozzle in relation to carburetor idle system jets and passages circuit.

(18) FIG. 8a and FIG. 8b is a cross section of the carburetor installed purge valve and attached air nozzle in relation to carburetor main system jets and passages circuit.

(19) FIG. 9 is an internal view of the carburetor with highlighted all carburetor systems jets and passages circuits.

(20) FIG. 10a shows the carburetor bowl retaining screw installation point on the carburetor for the motorcycles.

(21) FIG. 10b shows the purge valve location installation on the carburetor for the motorcycles.

(22) FIG. 10c shows the sub-components of the motorcycle type purge valve assembly 60 which consist of the valve core 41, the valve cap 42, a standardized threaded section 44, a metal tube 61, a customized threaded section 62 and a orifice restriction passage 63.

(23) 11a shows cross section of the motorcycle float type carburetors.

(24) FIG. 11b is detailed cross section of the motorcycle carburetor with the emphasize to carburetor bowl, fuel jets and passages.

(25) FIG. 12a is an external view of the method used to purge diaphragm carburetors used on small hand-held equipment like string trimmer, blowers, chain saws and other recreational vehicles like watercrafts.

(26) FIG. 12b shows diaphragm type carburetor fuel system with a three-way valve and purge valve installed on fuel feed line.

(27) FIG. 12c shows diaphragm type carburetor fuel system with a two-way valve and purge valve installed on fuel feed line.

(28) FIG. 12d shows diaphragm type carburetor fuel system with a check valve and purge valve installed on fuel feed line.

(29) FIG. 12e shows diaphragm type carburetor fuel system where pressurized can gets installed directly to the carburetor fuel feed port (without additional valves in line).

(30) FIG. 12f is cross section for diaphragm type carburetor with the purge circuit through the carburetor.

(31) FIG. 12g is a view of the method used to purge diaphragm carburetors where carburetor's primer bulb is activated the same time as the gas from the pressurized can.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(32) A small engine float type carburetor exploded view is shown in FIG. 1 having a carburetor body 1, throttle plate 2, choke plate 15, fuel delivery 7, Fuel filter 18, fuel shut-off valve 16, bowl 11, bowl retaining screw 10, float with needle valve 12.

(33) During engine operation the fuel from inside the bowl gets sucked through the main fuel jet 4, emulsion tube 3 and idle jet 19. All the fuel jets and the internal passages of the carburetor get wet with the fuel. Once the engine stops, some of the fuel from the jets and internal passages drains back to the bowl while some of it remains inside the jets and passages in a form of a tiny fuel film. The fuel remains inside the small openings of the jets and passages because of the fluid capillary effect. Over long sitting the ethanol from the fuel attracts water and corrosion builds up inside the small jets and passages. Over even longer period of sitting, the fuel from the bowl evaporates leaving corrosion and debris on the bottom of the bowl causing substantial problems when the engine is next time started. To prevent the formation of deposits inside the bowl, jets and passages the inside purging of the carburetor is suggested.

(34) The present invention has overcome these problems by purging the carburetor bowl, all the jets and all the passages with a compressed air and/or pressurized cleaning solvent. The installation of the purge valve on a preassembled carburetor is simple. The carburetor's bowl retaining screw is removed for the purge valve assembly, FIG. 2a. The carburetor can be delivered with the pneumatic one-way purge valve installed as well.

(35) Exploded view and cross section of the pneumatic one-way (Schrader) valve and cross section of the adapter assembly is shown in FIG. 3a. The assembly 43 consists of an externally threaded hollow cylindrical metal tube 40, typically of brass. The metal tube or adapter 40 is formed with a standardized threaded section 44 on one side so caps and tools generally are universal for the valves on all common applications. The customized threaded section 45 of the metal tube on the other side is made to fit within an outlet of the small engine carburetor bowl retaining assembly or drain plug in substantially permanent manner.

(36) Over-pressurization of the inside of the carburetor and in specific the primer bulb if equipped (not shown) connected to the carburetor is prevented by limited purge air flow. For this purpose, inside the metal tube 40 and on the customized threaded section 45 an orifice 46 is provided. In respect to the gas flow sense through the purge valve assembly 43, the orifice 46 is located after the valve core 41.

(37) In the center of the exterior metal tube end is the valve core 41. The core of the valve can be removed or tightened with a tool. The fuel from the carburetor and fuel tank can be drained through the purge valve once the valve core is removed.

(38) A valve cap 42 is used on a pneumatic one-way (Schrader) valve because if one is not fitted, dirt and water can enter the outside of the valve, potentially jamming it or contaminating the sealing surfaces and causing a leak.

(39) The cross section of the divided purge valve assembly is shown in FIG. 3a. This type of arrangement is necessary if the carburetor as installed on a machine is out of reach. In this case, the metal tube upper part 47 carries the valve core 41. On one side it ends with the customized threaded section 45 and orifice 46 while on the other side it ends with a barb fitting 49. The lower metal tube 48 one side ends with the standardized threaded section 44, cap 42 while the other side ends with a quick connect fitting 49a. The two barb fittings are connected with a hose 50 and both ends of the hose are secured to the barb fittings with a clamp 51.

(40) FIG. 4a shows the carburetor cross section with highlighted main fuel jet 4 and emulsion tube 3. The purge valve 43 mounts permanently inside threaded portion of the carburetor body 1 and under the main fuel jet 4 and emulsion tube 3. The air hose nozzle quick connect fitting 50 connects to the standardized threaded portion of the purge valve 43. This nozzle is just one of many types of commercially available nozzles from different manufacturers but is not part of this invention. FIG. 4b shows the same cross section but with all the components assembled. FIG. 4c shows the exploded view of the can 51 assembly: can activation valve 50b, hose 50a and connector nozzle 50.

(41) Pressurized with air and/or cleaning solvent can 51 connected through the quick connect nozzle 50 and purge valve 43 to the carburetor is shown in FIG. 5a. The pressurized can be replaced with a commercially available air compressor 52 with air tank 53 and air nozzle with or without a gauge 54 but with the quick connect or screw-on end 50.

(42) It is important to mention that the entire purge cycle is done on the carburetor 1 installed on the engine 100, FIG. 5c. There is no need to remove the carburetor from the engine. FIG. 5d shows and describes how to install the purge valve and method how to purge the carburetor.

(43) Internal Carburetor Purge in General

(44) In order for a combustion engine to run properly at different speeds and loads, the carburetor design provides four specific operating systems:

(45) e. Fuel delivery to bowl

(46) f. Idle system

(47) g. Transition system

(48) h. Main system

(49) Since the fuel gets in contact with all the four systems components, all the surfaces of the jets and passages of the four systems inside the carburetor have to be purged.

(50) Power Equipment Machinery Float Type Carburetor Purge

(51) With the fuel drained out of the carburetor through the drain plug 21 and the nozzle 50 attached to the purge valve 43 the carburetor is ready to be purged, FIG. 6a. The bottom view and the orthogonal view of the carburetor bottom without bowl cover 11 and float 12 installed are also shown on the right side of the FIG. 6a.

(52) Bowl Purge

(53) Compressed air enters the carburetor bowl cavity 70 through the purge valve and the two small openings 71 located beneath the main fuel jet, FIG. 6a. The pressurized mixture of purge air and remaining amount of fuel inside the bowl cavity 70 escapes to the outside of the bowl through the bowl vent 73 located in the top of the carburetor bowl cavity and vent port 74 located on the inner face of the carburetor body 75 out of the carburetor and into the atmosphere, FIGS. 6b and 6c. In case the fuel valve 16 is left open the air from inside the bowl escapes through the needle valve sit 76, fuel filter 18 and fuel delivery port 7 into the fuel tank (not shown). For this purpose, entire amount of fuel has to be drained from the fuel tank before the purging. In order to easier purge the remaining fuel from the bottom of the bowl, the drain plug 21 can be removed and the mixture of remaining fuel and purge air or gas can escape through the drain plug opening 95, FIG. 6a.

(54) Idle System and Transition System Purge

(55) As the purge air enters through the purge valve 43, it pressurizes the bowl and all the internal passages of the carburetor. As shown in FIG. 7a the idle system passages 80 and 81 get purged with the air passing through the main jet 4 and by the emulsion tube 3 on its way to the idle mixing chamber 19b located inside the plastic plug 19. Before the air reaches into the mixing chamber it passes through the idle fuel jet 19a located on the bottom of the plastic plug 19.

(56) FIG. 7b shows cross section of the carburetor through the final part of the idle and transition systems. On its way out of the mixing chamber 19b, the air scrubs off the remaining fuel and ethanol film from the passage 82 to the idle tiny opening 84 and transition system openings 83 all the way to the carburetor main flow cavity 85 located on the inner part of the carburetor 75. On the opposite side, the air passes through the idle air jet 83 and into the atmosphere or if equipped air filter box (not shown).

(57) Main Fuel System Purge

(58) FIG. 8a and FIG. 8b show the main fuel system purge. On its way upwards and out of the carburetor the pressurized air passes through the main jet 4 and emulsion tube 3 and into the carburetor main flow opening called Venturi 90. The air flow removes the remaining gasoline and ethanol film from the inside of the main fuel jet 4 first. Then, the air flow removes all the remains of gasoline and ethanol film from the inside and outside of the emulsion tube 3. Partial amount of this air flow purges the small orifices drilled across the emulsion tube 3. Since the cavity (air gap) between the outside of the emulsion tube 3 and the inside of the carburetor emulsion chamber 91 are connected through passage 92a. FIG. 8a and passage 92b FIG. 8b to the main fuel system air jet 93 seen in FIG. 8b, this amount of air escapes through the main system air jet 93 located on the outer face of the carburetor 94 and into the atmosphere or if equipped air filter box (not shown).

(59) It is necessary to mention that all four carburetor systems: bowl, idle, transition and main system get purged at the same time with multiple short blasts of compressed air or spray can solvent. FIG. 9 summarizes the purging of the carburetor systems:

(60) d. Carburetor bowl purging is represented with circle full arrow lines

(61) e. Idle and transition fuel system purging are represented with straight dashed arrow lines

(62) f. Main fuel system purging is represented with straight full arrows lines.

(63) Motorcycle Float Type Carburetor Purge

(64) In case of the motorcycle float type carburetor, the drain screw/plug 10 gets replaced with the purge valve assembly, FIG. 10a.

(65) Motorcycle type purge valve assembly is shown in FIGS. 10a, 10b and 10c. The assembly 60 consists of an externally threaded hollow cylindrical metal tube 61. The metal tube 61 is formed with a standardized threaded section 44 and cap 42 on one side. The customized threaded section 62 of the metal tube on the other side is made to fit within an outlet of the motorcycle type engine carburetor bowl drain plug 10. The orifice restriction passage 63 is located on the customized threaded side.

(66) The motorcycle type carburetor is a very similar design as the float type carburetors for the power equipment, FIG. 11a. Once connected to the pressure source through the connecting fitting 50 and purge valve 43 the air pressurizes the inside of the carburetor bowl 11. FIG. 11b shows detailed cross section of the bowl cavity 70 and the fuel jets. The pressurized gas from inside the bowl cavity 70 removes the remaining fuel from inside the main jet 4, emulsion tube 3 and idle jet 19. On its way out of the emulsion chamber 91, the air scrubs off the remaining fuel and ethanol film from the passage 82 to the idle tiny opening 84 all the way to the carburetor main flow cavity 85. On the opposite side, the air escapes through the main system air jet passage 93b into the atmosphere or if equipped air filter box (not shown).

(67) In case the fuel supply valve to the carburetor (not shown) is left open the air from inside the bowl escapes through the needle valve sit 76 and fuel delivery port 7 into the fuel tank (not shown). For this purpose, entire amount of fuel has to be drained from the fuel tank before the purging.

(68) Diaphragm Type Carburetor Purge

(69) Small hand-held power equipment uses diaphragm type carburetors (carburetor that can operate in any position even upside down). Diaphragm type carburetors can be found and on other types of engines like engines for watercrafts or airplanes.

(70) To separate the fuel tank 110 from the carburetor 1 so the inside of the carburetor can be pressurized, a three-way valve 57 can be installed on the fuel feed line 55, FIG. 12a. One of the ports of the three-way valve is connected to the purge valve 43, FIG. 12b. For engine operation the three-way valve 57 connects the carburetor inlet port 1a to the fuel tank. With the three-way valve in the other position the fuel tank gets disconnected from the carburetor while the purge valve 43 gets connected to the inlet port 1a of the carburetor allowing the pressurized gas from the can to reach the carburetor but not and the fuel tank.

(71) The purge valve 43 used on the diaphragm carburetors is of the same kind as the purge valve used on the float type carburetors for the power equipment machinery.

(72) Alternatively, the three-way valve can be replaced with a two-way valve 58 and a hose fitting tee 59. With this arrangement, the purge valve 43 is connected to one of the tee fitting 59 end, FIG. 12c. With the two-way valve 58 on the fuel from the tank can reach the carburetor allowing engine proper operation. To purge the carburetor, is necessary to turn the two-way valve 58 off. This way the pressurized gas from the can pressurizes the carburetor only and not and the fuel tank.

(73) While keeping the tee fitting the same, the two-way valve 58 can be replaced with check valve 56. During engine operation the check valve allows fuel to flow straight from the tank to the carburetor. During purging, the check valve will allow the gas to flow only to the carburetor FIG. 12d.

(74) Finally, the carburetor can be pressurized without any type of valves installed but for this system the fuel hoses from the carburetor ports 1a and 1b have to be disconnected. Pressurized can 51 hose 50b attaches directly to the carburetor inlet port 1a, FIG. 12e.

(75) With either of the arrangements, once activated, the pressurized gas from the can flows through the purge valve into the carburetor through the fuel inlet port 1a and into the diaphragm type pump 114. FIG. 12f shows the cross section of the diaphragm type carburetor. On its way through the carburetor, the gas flows through the pump's inlet check valve 112 then out of the pump chamber through the outlet check valve 113. The pressurized gas opens the spring 119 loaded control valve 115 and from there the gas flows inside the fuel metering chamber 116. At the time of the purge process, because of the high pressure inside the chamber the cover plate 117 protects the diaphragm 118 of the metering chamber 116 from rupture. Part of the flow pushes the fuel through the idle and the transfer system jet 121 and the main jet 122 into the main carburetor air/fuel mixing chamber/passage (Venturi) 85. The rest of the flow pushes the liquid fuel out of the carburetor through the outlet fuel port 1b and/or through the primer bulb (if equipped) 126.

(76) If equipped with a primer bulb 126, on its way out of the carburetor the gas flows through the primer bulb chamber inlet valve 123 and outlet valve 124. The entire amount of liquid fuel and ethanol get purged out through the carburetor outlet port (1b) into the fuel tank. Manual activation of the primer bulb 126 can help establish initial pressurized gas flow through the carburetor, FIG. 12g.

SUMMARY

(77) The method of purging the carburetor described is so great that thoroughly cleans the entire interior of the carburetor.

(78) The unique construction of the purge valve provides flush non-protruding abutment within the carburetor casing or fuel feed line, not interfering with the carburetor operation. Additional advantages include that the purge valve is easily attachable and removable from the carburetor but most importantly finally permits commercial disconnect compressed air attachments to be used in purging carburetors.

(79) While particular embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. The final result is that the efficiency of purging of the inside of carburetors is so great it leaves carburetors like in new condition.