Patent Publication Number: US-2021181055-A1

Title: Combustion chamber leak detection kit in vehicle engines

Description:
THE RELATED ART 
     The invention relates to a detection kit for detecting combustion chamber leaks in water cooled, internal combustion or internal burst vehicle engines. The invention particularly relates to a detection kit comprising an indicator solution made of CPP or BOPP film, which has high gas permeability, low water and vapour permeability, placed in a bag, and changes colour according to pH level, and additional components allowing this structure to be useful. 
     THE PRIOR ART 
     Nowadays, combustion chamber leaks in motors are investigated in Turkey by motor experts using roller compaction test, observation of water release on the piston or similar tests and techniques which require skills and do not give an exact result. In addition to those, in foreign countries combustion chamber leaks are identified by “combustion leak tester”, in which an apparatus containing bromothymol solution, sensitive to pH change, is propped to the entrance of motor expansion tank to determine gases exiting the expansion tank contain CO 2 , in other words with a colour change from blue to yellow meaning that the pH value is decreased under 7.6. 
     As well as determining motor leaks at the last stage after serious damages occurred, applications such as roller compaction test and observation of water release on piston necessitate technical understanding, expertise and intervention to motor. Considering their structures and usage, kits called combustion leak tester which is used in several countries and sensitive to CO 2 , may give positive or negative result incorrectly because of the risk of contamination of test liquid by coolant with antifreeze or its vapour. “Combustion leak tester” has high kit and test costs. Moreover, in consequence of its structure, it can only be applied when the vehicle is immobile and its expansion tank (expansion container) or radiator cap is open; hence, it cannot be applied at real usage conditions when motor is on load. Consequently, combustion chamber leaks occurring when motor is on a certain amount of load or incipient leaks at minimum level cannot be determined with this kit. 
     While diesel motors are not under pressure, high air inlet occurs into the combustion chamber. Hence, prior art kits and methods may give negative results in diesel engines even if there is a leak. 
     Since the currently used bromothymol solution is sensitive to temperature changes, it may give false results under closed-system conditions with high pressure and high temperature which may almost reach to 120° C. 
     It is impossible to determine and intervene to defects on the onset with available methods and kits, which may result in combustion chamber leaks in part such as gasket, cylinder barrel, cylinder head, and pad. In time, delaceration and leaks occur in refrigerating system components like radiator and hose, since combustion chamber compaction pressure goes into the refrigerating system. As a result of this, loss of water, overheating etc. unwanted situations occur in the motor. If these problems are not detected on time, they may lead the users to high cost solutions such as rectification or replacement of the motor. 
     Another technical problem arising from the prior art is that coolant liquid loss caused by high or mid-level combustion chamber leaks cannot be distinguished from any direct leak caused by a deformation on coolant liquid system and wrong diagnoses cause additional expenditures. 
     All the tests in the prior art are conducted in places such as repair or maintenance shop with unpractical methods by people who have adequate expertise. Hence, prior art applications are far from practical use. 
     In U.S. Pat. No. 4,750,350, a portable apparatus which is able to check whether there is a leak between water cooled, internal combustion chamber and refrigeration crust is disclosed. A structure is disclosed which can detect the cracks in the blocks of the apparatus, leaks at the cover gasket, or similar errors and problems in the motor. The apparatus comprises a top flange, a level indicating vessel attached to conical bottom flange, a longitudinal airline, control ball space in the airline at the top part of the conical flange, and a control ball. The height of water in the apparatus is approximately 2 centimetres. When the motor is working, bubbles are observed in the liquid level indicator vessel if there is any pressure leak. 
     The test kits which are the subject matter of the above given patent are likely to give false positive result considering their structures and usage, because of the risk of contamination of the test liquid by coolant with antifreeze or its vapour. Moreover, the reason of observing bubbles in coolant can be air taking leaking water&#39;s place, which can be any leak in recirculation system or refrigerating units, unrelated with the motor. Said test kit has high kit and testing costs. Moreover, due to its structure, it can only be applied when the vehicle is immobile and its expansion tank or radiator cap is open; hence, it cannot be applied at real usage conditions when motor is on load. This factor is extremely important, since some leaks manifest themselves only when the motor is under serious load. 
     As a result, improvement is to be made in combustion chamber leak detection tests in vehicle engines, and therefore novel embodiments that would eliminate the above said drawbacks and bring solutions to the problems of the prior art systems are needed. 
     DESCRIPTION OF THE INVENTION 
     The present invention relates to a combustion chamber leak detection kit in vehicle engines eliminating all the above given disadvantages and brings certain additional advantages. 
     The main purpose of the invention is to provide a vehicle engine leak detection kit embodiment, which can conduct real time and continuous leak testing while the vehicle is both idle and in normal usage, and provide a practical and inexpensive use, and give exactly correct results. 
     Another purpose of the invention is to eliminate the possibility of false positive or negative results by completely isolating the liquid used in the invention from the vehicle cooling liquid by means of a CPP and BOPP packaging with high gas permeability, no liquid permeability, and high water vapour barrier characteristics. 
     Another purpose of the invention is to allow the detection kit for working without giving false results in high temperatures using a solution which shows colour changes in low pH values such as 4.4-6.2. 
     Another purpose of the invention is to provide a test kit embodiment that can be used by everyone easily, and to provide a test kit that is practical and gives results in five minutes without the need for having an expertise, a special place, or additional tools to use the test. 
     Another purpose of the invention is to provide a low cost test kit structure, and thus make motor testing in a cost-efficient way in every purchase and sale, periodic maintenance, or any suspicious situation. 
     In order to achieve the purposes of the invention, a detection kit is provided for detecting combustion chamber leaks in water cooled Otto or diesel vehicle engines, and it comprises a transparent solution reservoir placed in an expansion tank and/or expansion tank inlet/outlet hoses, and having low liquid and vapour permeability and high CO 2  permeability, and a pH indicator solution placed in the solution reservoir, stable under high temperature and high pressure, and indicating combustion chamber leaks by change of colour with the change in the pH value. 
     Another important advantage of the present invention is that, in the prior art kits and methods, the water tank gases are passed through the indicator solution via vacuum or a pump; and therefore, the CO 2  in the system is directly exposed to the indicator by force if there is any leak in the engine, With this technique, it is not possible to classify the leak rate in the system as low, medium or high. However, in the leak detection kit according to the invention, since the indicator is isolated in a film permeable to CO 2  gas, it encounters with the pH indicator according to the CO 2  density, due to the law of diffusion of gases. Different densities of CO 2  cause the pH indicator to react in different colour tones. The observed different colour tones make it possible to classify the leak rate and/or amount. 
     The structural and characteristic features of the invention and all of its advantages shall be understood better with the figures and the detailed description given below in reference to the figures. Therefore, the assessment should be made by taking into account the said figures and detailed explanations. 
    
    
     
       FIGURES FOR BETTER UNDERSTANDING OF THE INVENTION 
         FIG. 1 ; is a general front view of a vehicle engine combustion chamber leak detection kit. 
         FIG. 2 ; is a front view of a transparent flow reservoir on which a solution reservoir containing the solution is connected. 
     
    
    
     REFERENCE NUMBERS 
     
         
           1 . Solution reservoir 
           2 . Solution 
           3 . Immersion rope 
           4 . Handgrip 
           5 . Flow inlet 
           6 . Flow outlet 
           7 . Transparent flow reservoir 
           10 . Test kit 
       
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In this detailed description, the preferred embodiments of the test kit ( 10 ) according to the invention are only disclosed for better understanding of the subject without forming any limiting effect. 
     The test kit ( 10 ), details of which are shown in  FIG. 1 , in general terms consists of a solution ( 2 ) that changes colour due to the change in pH when it contacts with CO 2  gas; a solution reservoir ( 1 ), into which the solution ( 2 ) is placed, which has a high liquid and vapour barrier characteristic, and high CO 2  permeability, and made of CPP or BOPP film depending on the usage; an immersion rope ( 3 ) that is slim enough for holding the solution reservoir ( 1 ) and made of HDPE film; and a handgrip ( 4 ) connected to the immersion rope ( 3 ) that facilitates holding and using the test kit ( 10 ). 
     The test kit ( 10 ) according to the invention is hanged down the expansion tank or water radiator such that the solution reservoir ( 1 ) would contact the cooling water, and then the cover is closed. In order to prevent the radiator cover from affecting impermeability while driving the vehicle, the immersion rope ( 3 ) is made of high strength HDPE film. The test kit ( 10 ) according to the invention may be used optionally for both instantaneous and long term measurements. For instant measurements, the test kit ( 10 ) with solution reservoir ( 1 ) made of CPP film is used. For long term measurements such as periodic maintenance &amp; control, the test kit ( 10 ) with solution reservoir ( 1 ) made of BOPP film which has higher water—vapour barrier feature is used. 
     No combustion gas is found in the coolant when water cooled internal combustion engines or internal burst engines operate properly. In case of a leak, the combustion gases mix into the coolant. Among these mixing gases, CO 2  has acidic characteristic. The CO 2  gas in the liquid can be determined by a pH indicator. General operating principle of the invention is as described above. The most fundamental characteristic of this structure is to provide a practical and low cost complete test kit ( 10 ) to the consumer, which is able to detect motor malfunctions. 
     The above said test kit ( 10 ) can be placed fixedly optionally on expansion tank return hose or expansion tank inlet hose so that it can directly be seen when the hood is opened. This fixed structure works as a warning system for users as soon as they open the hood. 
     If the combustion chamber leaks in vehicle engines are wanted to be observed constantly, the expansion tank return hose or the expansion tank inlet hose is cut and then the transparent flow reservoir ( 7 ) shown in  FIG. 2  is connected to the cut part. The transparent flow reservoir ( 7 ) forms a structure which can detect leaks continuously with the flow inlet slot ( 5 ), flow outlet slot ( 6 ), and the solution reservoir ( 1 ) made of BOPP film placed in the transparent flow reservoir, and the pH indicator solution ( 2 ) found in the solution reservoir ( 1 ).