BACKGROUND

Being able to effectively clean the interior of an internal combustion engine, particularly industrial and heavy duty engines, is valuable.

The present invention relates to a method and apparatus for cleaning the internal portions of heavy duty internal combustion engines. The engines are particularly those of automotive vehicles, marine vessels and industrial units. The engines may be either gasoline powered or diesel powered. Operating components of internal engines collect debris and residue which impairs engine performance. The lubricant which reduces friction in the moving engine parts eventually becomes contaminated with sludge, tar and other chemical contaminants which are produced during the operation of the engine and which are entrained in the lubricant. Also, small particulates of metal do become worn away from the operating parts of the engine and are carried in the lubricant. These small, metal particles can damage engine components that operate at high speeds and ^r temperatures. While regular lubricant changes are absolutely necessary to the continued operation of an internal combustion engine, engine components including valves, seals and other operating members do collect contaminants even if the lubricant is changed frequently. These contaminants reduce engine performance.

Various prior systems using cleaning fluids exist for cleaning the interior, operating components of internal combustion engines.

When the engine is to be cleaned the oil filter is removed, and the inlet supply line leading from the cleaning fluid pump is typically connected to the oil filter opening. Also the crank case drain plug is removed and a cleaning fluid withdrawal line is connected to the drain plug opening in the crankcase pan.

Cleaning heavy duty, industrial or marine-type internal combustion engines is a particular problem. Such engines are often located in awkward locations, making it difficult to locate adapters to an oil filter aperture or to a drain plug. It is thus unusual for such engines to be cleaned between lubrication changes. Also, engines used for heavy duty truck applications have similar problems. Debris and residue accordingly accumulate in unacceptable quantities in such engines. There is accordingly a need to provide a system for cleaning heavy duty industrial engines.

SUMMARY

According to the present invention, an apparatus and method is provided for cleaning the interiors of internal combustion engines in which a cleaning fluid is cyclically drawn from a reservoir by a pump, flushed through the block of the internal combustion engine, and returned to the reservoir by the pump.

Further according to the invention, lubricant from the engine is withdrawn under a pressure differential from the internal combustion engine prior to cleaning, soaking and flushing the engine with cleaning fluid.

The pressure differential is preferably created in an internal combustion engine by applying

preferably a vacuum or negative pressure on the drain plug opening to the internal combustion engine. Additionally or alternatively a positive pressure can be applied to the oil filter opening. Cleaning fluid is pumped from a cleaning fluid reservoir through the internal combustion engine. A first quantity of cleaning fluid is held in the internal combustion engine throughout a first soaking interval and then withdrawn. The first quantity of cleaning fluid is filtered as it is withdrawn to remove contaminant particles therefrom and is recovered. Cleaning fluid is then pumped through the internal combustion engine a second time. A second quantity of cleaning fluid is held in the internal combustion engine throughout a second soaking interval, and then withdrawn from the internal combustion engine. The second quantity of cleaning fluid is filtered to remove contaminant particles therefrom and recovered. Lubricant is then replaced in the internal combustion engine.

The invention is further described with reference to the accompanying drawings.

DRAWINGS Figure 1 is a perspective view of apparatus used for cleaning an internal combustion engine. Figure 2 is a diagrammatic view of the operating components of an engine cleaning machine for operating with a pressure differential for removing lubricant from an engine.

Figure 3 is a chart showing the condition of the various valves of Figure 2 during the different phases of a cycle of operation of the machine of Figure 2 for cleaning an internal combustion engine with a supply of cleaning fluid.

Figure 4 is a timing diagram showing the operation of the valves according to the chart of Figure 3.

Figure 5 is a diagrammatic view of the operating components of an alternative engine cleaning machine for operating with a pressure differential for removing lubricant from an engine.

Figure 6 is a diagrammatic view of the operating components of an alternative engine cleaning machine for operating with a 3-pump set up and with a pressure differential for removing lubricant from an engine.

Figure 7 is a chart showing the condition of various pumps and valves in a 3-pump set up in relation to the operation of Figure 6.

Figure 8 is a diagrammatic view of the operating components of an alternative engine cleaning machine operating with a 2-pump set up and with a pressure differential for removing lubricant from an engine.

Figure 9 is a chart showing the condition of the various valves of Figure 8.

DESCRIPTION A shown in Figure 1, apparatus 10 is utilized for cleaning the interior of an internal combustion engine 16 shown in Figure 2. The apparatus 10 has a console panel 12 and is mounted on wheels 14. The internal combustion engine 16 is of an industrial, heavy duty or marine type design and has an engine block that includes a conventional lubricating oil filter opening 18, which normally is formed by an annular outer ring within which there are various ports or openings to accommodate oil flow. At the center of the oil filter opening 18 there is typically a hollow, externally threaded nipple which forms a central axial duct to accommodate oil flow. The oil filter opening 18 is

adapted to receive a removable, replaceable oil filter cartridge which is secured by threaded engagement with the central axial nipple and which forms a liquid tight seal with the outer, annular ring. The engine 16 also includes a conventional internally threaded oil drain opening 20, usually at the bottom of the oil pan. The oil drain opening 20 accommodates an externally threaded drain plug. The drain plug is normally removed when lubricating oil in the engine 16 is changed.

The operating components of the cleaning apparatus 10 are indicated diagrammatically in Figure 2. The internal combustion engine cleaning apparatus 10 is designed to be connected to the engine filter coupling opening 18 and the engine drain opening 20 and to cyclically circulate a cleaning fluid through the block of the internal combustion engine 16.

A reservoir 22 has a thirty gallon capacity. The reservoir tank 22 contains a volume of liquid cleaning fluid designed to remove residual combustion deposits from the internal passageways and internal operating components of the internal combustion engine 16.

The cleaning apparatus 10 employs separate supply and return cleaning fluid conduits connected to the cleaning fluid reservoir 22. The supply conduit 26 is from the reservoir 22 and the return conduit 28 for the reservoir 22.

The cleaning apparatus 10 also includes a fluid inlet selection valve 52 and a separate fluid outlet selection valve 54. Both of the fluid selection valves 52 and 54 are solenoid operated spool valves. Each of the fluid selection valves 52 and 54 has a single fluid outlet port. The fluid inlet selection valve 52 has a fluid outlet port 56 while the fluid outlet selection valve 54 has a fluid outlet port 58.

The fluid inlet selection valve 52 also has an air inlet port 60 and a cleaning fluid inlet port 62. The air inlet port 60 is connected to the top of reservoir tank 22 by air conduit 63. Similarly, the fluid outlet selection valve 54 has inlet port 64 mounted to tank 22 and a cleaning fluid inlet port 66. The inlet port 66 is connected to an engine outlet cleaning fluid withdrawal line 102.

The fluid selection valves 52 and 54 are operable to gate their respective air inlet ports and cleaning fluid inlet ports to their respective fluid outlet ports. That is, the fluid inlet selection valve 52 is operated under the control of cycle controller indicated generally at 68 by means of a control line 70 to alternatively open a passageway between either the inlet port 60 or the inlet port 62 to the fluid outlet port 56. Similarly, the cycle controller 68 controls the fluid outlet selection valve 5,4 by means of a control line 72 to alternatively open a passageway from either the air inlet port 64 or the cleaning fluid inlet port 66 to the fluid outlet port 58.

The cleaning apparatus 10 also includes a pump which may be operated by compressed air, although an electronically operated pump could be employed instead. The pump 74 is a double diaphragm pneumatic pump that has first and second suction inlets 76 and 78, respectively and first and second fluid dispensing outlets 80 and 82, respectively. The first suction inlet 76 is connected to the fluid outlet port 56 of the fluid inlet selection valve 52 by means of a coupling conduit 84. The second pump suction inlet 78 is connected to the fluid outlet port 58 of the fluid outlet selection valve 54 by another coupling conduit 86. A reservoir air line 65 is connected from the top of the reservoir tank 22 to the air inlet port 64 of the fluid outlet selection valve 54. A second reservoir

air line 63 is connected from the top of the reservoir tank 22 to the air inlet port 60 of the fluid inlet selection valve 52.

An engine inlet supply line 90 is connected from the first fluid dispensing outlet 80 of the pump 74 is the nipple 200 mounted on the apparatus casing 10 and leads through nipple 200 and hose 90 to engine filter coupling opening 18. In the embodiment depicted the engine cleaning fluid inlet supply line 90 leads to the filter coupling opening 18.

An engine outlet nipple 206 is mounted on the casing of the apparatus 10. A separate removable hose 103 would connect with the engine adapter 106. Inside the apparatus 10 the nipple 206 is connected to the cleaning fluid inlet 66 of the fluid outlet selection valve 54. The cleaning fluid outlet withdrawal hose 102 is connected with the nipple 206 through a conventional sliding seal arrangement that exist at the interfaces of the termination of the cleaning fluid outlet withdrawal hose 102.

In the line 108 from pump 74 there is provided a valve 300. The valve 300 is connected through nipple 304 mounted on the apparatus 10 with line 301 to a drain 302. In turn, the valve is operable by a control line 303 with which is connected with the cycle controller 68.

In one position of valve 300, when the valve 300 is operated prior to the cleaning cycle, a pressure differential is applied to the engine block 16 to drain lubricant from the engine block 16. This pressure differential is applied through line 102 connected to the drain plug 20. The opening 18 can be closed during this procedure. A differential pressure of 41 lbs/inch ² is applied to the interior of the engine to effect lubricant withdrawal.

The cleaning machine 10 is also equipped with a shop compressor 120 that supplies compressed air

through an air supply hose 122 to an air valve 124. The air valve 124 is connected by means of a conduit 126 to a compressed air inlet port 129 in the pump 74. The compressor 120 is employed to drive the pump 74 to concurrently pump fluid from the first suction inlet 76 to the first fluid dispensing outlet 80 and from the second suction inlet 78 to the second fluid dispensing outlet 82. The air valve 124 is operated under the control of the cycle controller 68 through a control line 226. Through the compressor operating pump 74 with valve 300 the appropriate vacuum is applied to the engine block to drain oil prior to cleaning the engine block 16.

The cleaning machine 10 also includes a recycle line 128 that is coupled from the second fluid dispensing outlet 82 of the pump 74.

A five micron contaminated cleaning fluid filter 130 having a transparent housing is positioned in the recycle line 128. The cleaning apparatus 10 also has several other features. The reservoir 22 includes a heating element and heat sensor unit, indicated diagrammatically at 131, respectively. The heat element and heat sensor unit 131 for the reservoir 22 provides a status output on indicator line 134 to the display and operation controller 48. The indicator line 134 is respectively connected to a manually operable heater switch in the display and operation controller 48.

When the operator manually makes a selection using a toggle switch that sends a control signal on line 137 to cycle controller 68 that in turn generates a control signal on line 50 to operate the reservoir tank 22. The operator also manually operates a toggle switch associated with the heat control and sensor unit associated with the reservoir selected. Upon actuation of the switch associated with the selected reservoir

tank 22, a control signal is sent to the heat control and sensor unit associated with that reservoir heater.

The heat sensor associated with the heater provides a signal back to the display and operation controller 48 over the line 134 once the cleaning fluid within the selected reservoir tank has reached a sufficient temperature. This signal on line 134 illuminates a light located within the toggle switch associated with that reservoir heater to inform the operator that the cleaning fluid has reached a high enough temperature for use.

The reservoir 22 is equipped with a level sensor, indicated diagrammatically at 139. When the cleaning fluid reservoir level sensor 139 for the reservoir tank 22 indicates that the liquid level of cleaning fluid in the tank 22 is too low, it provides a control signal output on control line 140. If a signal appears on line 140, a signal is generated by the display and operation controller 48 to the cycle controller 68 on line 144. The cycle controller 68 then closes the air valve 124 by a signal on line 226, which shuts off power to the pump 74. This alerts the operator that the reservoir tank 22 is low on cleaning fluid and that the cleaning fluid should be replenished. The reservoir 22 is provided with a separate cycle counter that increments each time the reservoir has been utilized for a complete cycle. The cycle counter for the reservoir 22 is located in the display and operation controller 48. The cycle counter for the reservoir 22 is incremented by a signal on line 146 from the cycle controller 68 each time the first reservoir 22 has been selected for use and the pump 74 has been actuated to operate for a complete flush cycle.

The cyclical operation of the apparatus 10 and the manner of application is described with reference to Figures 3 and 4. Prior to the cleaning cycles as illustrated in Figures 3 and 4 through air valve 40

there is a phase where the engine is vacuum drained of lubricant through valve 300.

Figure 3 illustrates the conditions of the air inlet valve 124, the fluid inlet selection valve 52, and the fluid outlet selection valve 54. Figure 3 illustrates the conditions of these valves when the apparatus 10 is employed to clean an internal combustion engine 16.

The designation "0" with respect to the air valve 124 indicates that the valve is in an open condition during which there is pneumatic flow of compressed air from the conduit 122 to the conduit 126. In this condition the compressor 120 is coupled to supply compressed air to the pneumatic inlet port 129 so that the pump 74 operates. In the opposite closed condition indicated by "C" the compressor 120 is isolated from the pneumatic inlet port 129, and the pump 74 does not operate.

The designation "C" with respect to the fluid inlet selection valve 52 indicates that the valve 52 has been operated to allow flow from the cleaning fluid coupling line 67 through the cleaning fluid inlet port 62 to the fluid outlet port 56 and on to the coupling conduit 84 leading to the first suction inlet port 76 of the pump 74. The designation "0" with respect to the fluid inlet selection valve 52 means that air is drawn through the line 63 from the top of the reservoir tank 24 through the air inlet port 60 to the fluid outlet port 56 of the inlet selection valve 52. This allows the pump 74 to pump air from the first suction inlet port 76 to the first fluid dispensing port 80.

The indication "C" with respect to the fluid outlet selection valve 54 indicates that there is free flow from the engine cleaning fluid outlet withdrawal line 108 through the outlet valve 54 to the fluid outlet 58 thereof leading to the second suction inlet 78 of the pump 74. In this condition the pump 74 can pump

cleaning fluid withdrawn from the engine block of the internal combustion engine 16 through the outlet valve 54 to the recycle line 128.

When the fluid outlet selection valve 54 is in the condition indicated by "0", on the other hand, flow from the engine cleaning fluid outlet withdrawal line 108 is blocked and the pump 74 instead draws air through line 65 and air inlet port 64 of fluid outlet selection valve 54. Air is thereupon pumped through coupling conduit 86 to the second suction inlet port 78 of pump 74 and passed to the second fluid dispensing outlet port 82 thereof. This prevents the pump 74 from trying to pump a vacuum when cleaning fluid should not be pumped through engine cleaning fluid outlet withdrawal line 108. The reason for pumping air from the top of the reservoir 22 rather than just drawing in ambient air is to avoid drawing in particulate matter which is often present in automotive servicing facilities of the type where the equipment is typically utilized.

Operation

To commence operation of the system, lubricant is drained under vacuum from the engine 16. The adapter 100 is connected to the engine filter coupling opening 18, while the adapter 106 is connected to the engine drain plug opening 20. Operation of the system is then commenced by drawing the engine oil through valve 300 and line 301 to drain 302. This is effected from port

20 through line 102 to outlet valve 54, through line 86 to pump 74, through outlet 82 to line 108. There is no time limit applied for this vacuum drain. The oil is drained through a hose line 301 connected to the nipple

304 at the inlet to valve 300.

Figure 3 illustrates the timing and sequence of operation of the valves 124, 52, ^' and 54 when the apparatus 10 is operated. When the cycle of Figure 3 is actuated by means of a switch on the display and

operation controller 48, the air valve 124 opens and stays open for 180 seconds. This commences operation of the pump 74 with the fluid inlet valve 52, the fluid outlet selection valve 54 in the closed position. Thus, vacuum withdrawal of lubricant is effected, once the pump 74 commences operation. Thereafter cleaning fluid is pumped through the supply conduit 26 from the reservoir tank 22, to the cleaning fluid inlet 62 of fluid inlet selection valve 52. The cleaning fluid from conduit 26 is pumped through valve 52 and connecting conduit 84 to the first suction inlet 76 of the pump 74. From there, it is pumped through the engine inlet supply line 90. The incoming cleaning fluid continues to pass through the engine cleaning fluid input supply line 90 and enters the engine 16 through the engine filter coupling opening 18.

Since the fluid outlet selection valve 54 is in the closed condition, cleaning fluid is flushed through the engine outlet withdrawal hose 102. The fluid passes from cleaning fluid inlet port 66 of the fluid outlet selection valve 54 to coupling conduit 86 leading to the second suction inlet 78 of the pump 74. The pump 74 forces the contaminated cleaning fluid through the second fluid dispensing outlet 82 where it enters the recycle line 128. Most of the contaminated material in the fluid in the recycle line is removed by the filter 130, which remove matter that is three microns or greater in size. The recovered cleaning fluid passes through the return cleaning fluid conduit 28 to the reservoir tank 22.

Throughout most of the first flushing period the internal combustion engine 16 contains about five gallon of recirculating cleaning fluid. When 275 seconds have elapsed the fluid outlet selection valve 54 opens, thereby blocking cleaning fluid withdrawal line 108 and preventing the further withdrawal of cleaning fluid. This allows the quantity of cleaning fluid in

the internal combustion engine 16 to build up to a volume of about seven gallons. With the outlet fluid selection valve 54 open, air is drawn through conduit 65 from the upper portion of the reservoir tank 22 and pumped to the second suction inlet 78 of the pump 74, so that a vacuum at the second suction inlet 78 is avoided. At 300 seconds into the cycle the fluid outlet selection valve 54 is closed again and the air valve 124 is also closed. This halts operation of the pump 74 for the 50 second interval that the air valve 124 remains closed. During this time, from 275 to 350 seconds, the seven gallon quantity of cleaning fluid is held in the internal combustion engine 16 to soak combustion deposits from the internal operating components of the engine.

At 350 seconds the air valve 124 is again opened and the fluid inlet selection valve 52 is opened to block flow from the cleaning fluid inlet port 62 to the fluid outlet port 56 of the fluid inlet selection valve 52. Instead, air is pumped from the air inlet port 60 through coupling conduit 84 to the first suction inlet 76 of the pump 74. This allows air to be drawn from the upper portion of the reservoir 24 through air conduit 63 to the first suction inlet 76 of the pump 74, thereby preventing a vacuum from occurring at first suction inlet 76.

During the 50 second period between 300 and 350 seconds in the operating cycle that the fluid inlet selection valve 52 is open, cleaning fluid cannot enter the internal combustion engine 16 through the engine filter coupling opening 18, but is withdrawn through the fluid withdrawal line 102 where it passes through the fluid selection outlet valve 54 and travels through the recycle line 128 to return to the reservoir 22. At 350 seconds there is little if any cleaning fluid left in the internal combustion engine 16.

At 350 seconds the inlet fluid selection valve 52 is once again closed. Air valve 124 momentarily closes, but immediately reopens. Since the outlet fluid selection valve 54 remains closed, cleaning fluid can once again circulate fully through the system from supply line 26 through first suction inlet port 76 of the pump 74, through the cleaning fluid inlet supply line 90 and the inlet hose 98. During this period the cleaning fluid is flushed through the internal combustion engine 16 and is returned to the reservoir 22 through the withdrawal hose 102, withdrawal line 108 and recycle line 128.

At 695 seconds into the cycle the fluid outlet selection valve 54 once again opens, thereby preventing further cleaning fluid from being withdrawn through the engine drain port 20. The volume of cleaning fluid in the engine 16 once again builds up to about seven gallons. At 720 seconds the outlet fluid selection valve 54 again closes and the air valve 124 also closes. This stops operation of the pump 74 to allow the second quantity of cleaning fluid within the internal combustion engine 16 to be held for a second soaking interval while the pump 74 remains dormant.

At 770 seconds the air valve 124 again opens, thereby reactivating pump 74. The inlet fluid selection valve 52 opens, thereby preventing further cleaning fluid from being withdrawn from the reservoir 22 and passed to the internal combustion engine 16. Since the fluid outlet selection valve 54 remains closed, the cleaning fluid continues to be withdrawn through the withdrawal hose 102, withdrawal line 108 and recycle line 128. The engine is thereupon completely drained of cleaning fluid. This ends the second recovery period and terminates the cleaning cycle. Lubricant is thereafter replaced in the internal combustion ^' engine 16, and the vehicle is again ready for use with the engine in a fully cleaned condition.

After about forty engine cleanings the cleaning fluid in the reservoir 22 is replaced.

By removing the lubricant from the engine block under pressure, namely vacuum or suction, prior to cleaning, flushing and soaking the engine block, collected debris from lubricant in the engine block is effectively removed prior to cleaning. Accordingly, heavy duty industrial engines, such as marine engines, engines for trucks, engines in plants and industrial sites can be effectively cleaned in this manner. In some cases a positive pressure can be applied to the engine to force the engine lubricant out of the engine block prior to cleansing.

In the arrangement of Figure 5 the valve 52 and 54 from Figure 2 are replaced by solenoid valve 152 and a different solenoid valve 154. When valve 152 operates, a vacuum is broken and this terminates suction of solution from the tank 22 to the pump 74. Valve 154 is operated by the electrical line 70 from the controller 68. Solenoid valve 154 operates to break a vacuum to cause the evacuation of fluid from the oil pan of the engine.

The flow of cleaning fluid from tank 22 passes directly to pump 74 through filter 92. It avoids passing through a valve 52 as illustrated in Figure 2. Flow of lubricant from the engine is also effected directly with the pump 74.

The embodiment with regard to Figures 6 and 7 is now described. The first operation is waste oil removal. Before a flush, the adapter is hooked up to the orifice. The oil filter orifice has two adapters. Waste oil is removed from engine 16 through the line 102 to the recovery pump 74a. Then it goes to the waste oil selective valve 54 which opens and then the oil goes to the EPA waste disposal tank.

The operator starts the flush, and the operation goes to the normal flush cycle. Both pumps

operate in the recovery and pressure. The solution is taken out of the tank to line 26 to filter 92 with the 3 micron filter to a vacuum selector valve 52. The solution goes to line 84 to the pressure pump 74, and then to the Y7 tank filtering selector valve which stays in the closed position. The solution goes to the oil filter port from the engine 16.

In the meantime, lubricant has been sucked out to the recovery pump 74a through 54. This is now -in the opposite position and the fluid runs through the five micron filter 130, and then to line 28 and back to the tank. This is the normal flush cycle.

A bypass flow meter to line 28 operates so that if there is not enough recovery by some restriction in the passageways on the adapter or something, then it shuts off the machine. This acts as a warning system to prevent overfill of engines during the service.

Then, the system goes to the soak mode. During the soak mode, the pressure pump 74 stays on. The tank filtering selector valve Y7 pump is diverted so the fluid goes to that line to the .10 micron filter system. This is a centrifical filter which spins at 6,000 rpm and filters the solution in the tank. It goes back to the tank through a closed loop during the recovery and during the soak. The pressure pump keeps running and nothing goes into the oil filter port in the engine. The fluid recirculates in the tank and cleans the fluid in the tank. This keeps the fluid cleaner for a longer period of time. The fluid may be used longer, namely for many more services. Then, the second flush operates. At the end of the second flush, which are the same cycles as before, except that the tank filtering selector is separated. Thereafter the cycle goes to soak and recovery and runs on a constant basis. After that, the prime pump starts working.

There is an oil tank mounted on the side of the machine. This is a 36-quart oil tank with a pump built onto it

with a separate hose that also goes to the oil filter adapter and primes the engine. The engine is primed with 2 quarts of fluid to force out the leftover solution and create optimum lubrication. While this happens, the recovery pump 74a is activated and removes the solution being forced out into the waste oil tank and also the new oil that had been pumped in. This is removed to 102 to the pump 74a and back to the EPA waste oil disposal tank. The service is then completed. The Figures 8 and 9 define a system with 2 pumps. This is similar to Figures 6 and 7. There is no prime pump. Instead it uses the pressure pump. Oil goes from the oil refill tank, namely the tank 36-quart tank, to the oil prime valve, Y4. The fluid goes to the pressure pump. The clean oil is forced into the oil filter port instead of having a separate pump for that purpose. A separate second line goes to the oil filter port. The 2-pump is a set up with an extra valve, namely an oil prime valve instead of a prime pump. The rest of the system and operation is similar to Figures 6 and 7.

The various components of the operating systems of Figures 6 and 8, as appropriate, include the following: INPUTS:

X0 Top level sensor

XI Low level sensor

X2 Empty level sensor

X3 Flow meter (recovery) X6 Low temp sensor

X7 Hi temp sensor

OUTPUTS:

Yl SSR heater Y2 Buzzer

Y3 Recovery pump

Y4 Prime pump

Y5 Pressure pump

Y6 Waste oil selector valve

Y7 Tank filtering selector valve

Many variations and modifications of the invention will become apparent to those familiar with internal combustion engine cleaning equipment and procedures. The scope of the invention is to be determined solely by the following claims.