Patent Application
20210140843
The invention relates to a device for detecting cylinder leaks in an individual cylinder of an internal combustion engine having the cylinder head disassembled and wherein the piston in the tested cylinder is positioned at the bottom dead center and wherein a dual gauge leak down tester is coupled to the herein disclosed device.
The internal combustion engine has been a fundamental life-changing invention for humanity. It allows the conversion of chemical energy into mechanical work, which is achieved via the combustion of a gaseous mixture of fuels and an oxidizing agent, usually air, under high temperature and pressure conditions. Thus, this combustion must be performed in a confined location, well known as a combustion chamber. This gaseous mixture is compressed by the movement of a piston up to the top section of the cylinder, thus reducing the area of the combustion chamber and further igniting the gaseous mixture, thus generating a high pressure and high temperature gases, that quickly accelerates the downwardly motion of the piston, which transfer the mechanical energy from the piston to a rotating shaft. Thus, for an internal combustion engine function properly and efficiently, the composition subjected to compression and combustion must be kept confined under pressure inside the combustion chamber.
Ideally, leaks of said gaseous composition from the combustion chamber should not occur, nonetheless, in a practical sense some degree of leaks of said composition does takes place and are expected without drastically affecting the engine performance. The percentage of permissible or expected leakage of said gaseous composition is most of the time determined by the manufactures. However, when the percentage of said leakage is higher than expected, proper functioning of the engine is negatively affected since the concentration of the composition to be ignited is decreased and thus, the generated mechanical work from said combustion is therefore reduced. Continuous used of the engine usually promotes such leaks due to the wear and tear of the engine components related to the combustion chamber such as but not limited to the piston, piston rings, valves or cylinder wall wear. Therefore, engine lack of performance, diagnosis, maintenance and repair processes regularly require testing the ability of the combustion chamber to properly confine the gaseous mixture subjected to combustion. Detecting said leaks is generally done by performing a Leak Down Test, which is a well-known and conventionally test wherein a commercially available Dual Gauge Leak Down Tester is required. In general terms, said tester allows and measure an input of air pressure inside an engine, while allows the measure of the pressurized air escaping from the combustion chamber.
The leak detection test requires that the engine is turned off, the cylinder head is properly assembled to the cylinder block, the intake and exhaust valves must be closed and that the piston to be tested is positioned at its top dead center. In general terms, the leak-down test is performed by coupling the tester to an air compressed source, such as an air compressor, and to the spark plug hole of the cylinder under testing and subsequently, feeding pressurized air into the cylinder. One of the gauges in the tester measures the percentage of air pressure that is being introduced in the cylinder from the compressed air source and the second gauge measures the percentage of air pressure that is leaking out from the combustion chamber. If a leak is detected, air pressure must be escaping from one or more of the following engine parts: intake valve, exhaust valve, piston rings, head gasket or cracked cylinder head.
A serious limitation of the leak down test is that a false reading may be obtained if the piston is not properly set up at its top dead center, since air may escape by partially open valves. Similarly, if the piston is set properly at its dead top center, the test is limited only to area enclosed by the engine head and the upper section of the engine block that constitutes the combustion chamber and its components but it does not include the lower section of the cylinder or the cylinder block section located under the piston rings. Thus, if the results of the leak down test indicates that there is a significant leak in the cylinder—the leak may be presumed to occur only in any section of the combustion chamber, located in the area under the engine head and the top of the cylinder—cylinder block—under test or the engine's valves, but there may also be additional leaks in the lower section of the cylinder or cylinder block, the piston and the piston rings that due to the fact that, since the piston is on its top dead center during the test, said sections are not subjected to the air pressure and thus, leaks in said areas may be ignored or undetected. On the other hand, if the leak down test detects only leaks within the acceptable parameters or no leaks at all, even though that a leak is suspected or a lack of compression is detected, such leakage may very well found in the lower section of the cylinder or cylinder block, the piston or piston rings that are not subjected to and not detectable by the leak down test. Thus, repairment would require disengaging the engine into parts, what is a time consuming and hard work besides resulting in higher reparation costs to Clients.
Thus, there is a need to perform a more accurate, convenient, economical, direct and simple cylinder leakage test that includes the complete main body of the cylinder, particularly a test able to detect leaks due to piston, piston rings or the lower section of the cylinder or cylinder block.
The herein invention provides an apparatus for detecting leaks in the cylinder, piston and piston rings in an open cylinder of an engine block having the head dissembled and having the piston of the tested cylinder positioned at is lower dead center. The device is positioned and secured above the cylinder mouth by means of the engine head bolts and further coupled to a dual gauge leak down tester in order to introduce pressurized air within the cylinder. In this manner the percentage of air pressure coming inside the cylinder and the percentage of air pressure escaping from the interior of the cylinder are measured in order to detect potential leaks in the cylinder, piston and piston rings. The invention also provides a more precise test in order to properly identifying all the engine components from wherein leaks maybe taking place. In this manner, if no engine leaks are identified with the herein disclosed tool, there will be no need to dissemble and repair the lower engine section, saving time and engine reparation costs to the engine's owner.
The foregoing and additional features and characteristics of the embodiments of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawings, which are used herein in a manner of example only, and wherein:
The present invention and its detailed embodiments are disclosed herein. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms within the scope of the invention. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art how to make and to use the present invention. It is thus to be understood that, this invention is not limited to particularly exemplified structures, components, methods or uses, as such may, of course, vary. In the drawings, the size and relative sizes of regions may be exaggerated for clarity. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show details of components or parts. It is also to be understood that the terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the scope of the invention in any manner. It must be noted that, as used in this specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the content clearly dictates otherwise. Similarly, it will be understood that when an element is referred to as being “on”, “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or intervening elements may be present. On the other hand, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element, there are no intervening elements present. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that, although the terms “first”, “second”, “third” and the like, are used as a relative reference to any other part of the invention, in order to properly explain and identified the particular details of the invention, and that such terms may be used herein to describe various elements, components, regions and/or sections, these elements, components, regions and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region or section from another element, component, region or section. Thus, a first element, component, region or section discussed below could be termed a second element, component, region or section without departing from the teachings of the present invention. Furthermore, spatially relative terms, such as “beneath,” “below” “lower”, “above” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below”, or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented or subjected to a rotation in each orientation and the spatially relative descriptors used herein interpreted accordingly. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Since there are different sizes of cylinders and engines, the herein disclosed device and its components are illustrated in relative sizes to the illustrated cylinder and it understood that the size of the device and its components may increase or decrease relative to the size of the cylinder upon which the device is used or intended to be used.
In general terms, the instant invention comprises device 10, for detecting cylinder leaks directly in an individual cylinder 15 of an open internal combustion engine block 14, which has its cylinder head disassembled from the engine block and wherein the piston of the cylinder under testing has been rotated or positioned at its lower point in the cycle.
Device 10 is used in conjunction with a conventional dual gauge leak down tester 12, illustrated in
In
Sealing unit 18 is made of a pliable and strong material suitable to provide a sealable compressed air path when subjected to pressure and placed in a tight or firmly enclosed environment. On the other hand, bolt 16, washer 17, base 19; shaft 20, air hose adapter 21, cylindrical shaft collar 22 and clamps 23 and 24 are made of a strong and rigid material capable of withstand compressed air pressure flow while entirely keeping its constitution without any sort of deformation.
As illustrated in
Seal unit 18 is illustrated in
Regarding the upper section of device 10, the shaft 20 is illustrated in top perspective views on
Shaft 20 also comprises a first recess 53 and a second recess 54 near the first threaded end 44. Such recesses 53 and 54 are suitable ergonomic features that facilitates grasping elongated body 40 in order to tightening and loosening it. Similarly, shaft 20 also comprises round recess 55 on surface of elongated body 40.
Second internally threaded end 43 of shaft 20, as well as the section of shaft 20 comprising the first and second O-rings 50 and 52 already housed in O-rings channels 48 and 49, are inserted into aperture 39 of base 19, wherein the second internally threaded section 43 is threaded and tightened to threaded end 27 of vented bolt 16; thus, confining washer 17, seal unit 18 and base 19 in between vented bolt 16 and the lower surface 47 of the cylindrical flange 45, which is in direct contact with upper surface 37 of base 19. In this manner, continuous internal channel 42 of shaft 20 is in direct communication with the opening 25 passing through bolt 16; thus, creating a totally sealed airtight internal path that allows compressed air to flow freely through it.
As illustrated for instance, in
Device 10 also comprises lower clamp 23 and upper clamp 24, which are a set of two coordinated or matching clamps capable of facilitating fastening and securing the device 10 above the open cylinder 15 on engine block 14 by providing channels that receive and support the engine head bolts 66, previous to insert, thread and tight said engine head bolts 66, into the threaded holes 67 of the engine block 14.
Lower clamp 23 is illustrating in
A top perspective view and a bottom perspective view of upper clamp 24 are illustrated in
As illustrated in
Similarly, shaft 20 is also inserted into upper clamp 24 through said circular aperture 91, via said lower section 84 of said second clamp 24. As a consequence, upper clamp 24 is superimposed on lower clamp 23 in a cooperatively manner by inserting first indentation 87 of upper clamp 24 inside the first indentation 75 of the lower clamp 23 while placing the left and right extremes of the second indentation 87 of upper clamp 24 in direct contact with the upper surface 37 of the base 19 and setting elongated channels 78, 79, 89 and 90 around base 19.
Lower and upper clamps 23 and 24 are kept confined to the interior of the shaft 20 by inserting cylindrical shaft collar 22 into the shaft 20 until bottom section 65 of said collar 22 is inserted into the counterbore section 92 on the top section 83 of upper clamp 24, and the security screw 64 is tightened on lateral threaded aperture 63 until the tip of screw 64 is received on indentation 55 on shaft 20, as illustrated in
As illustrated in
The first internally threaded end 44 of the shaft 20 is tightened to threaded section 59 of the air hose adapter 21. Thus, the internal channel of the air hose adapter 21 is in direct communication with the internal channel 42 of shaft 20. Thus, since continuous internal channel 42 of shaft 20 is also in direct communication with the opening 25 passing through bolt 16, a sealed airtight channel that allows compressed air to flow throughout the interior of invention 10 is created.
As indicated above, device 10 is used in connection with a dual gauge down lock tester 12, as the one illustrated in
In operative terms, as illustrated in
In some instances, and depending on the shape and dimensions of the engine head bolts 66, they may be inserted in suitable and commercially available bolt spacers 60, such as those illustrated in
Device 10 is cooperatively coupled to a dual gauge down leak tester 12 by connecting plugin section 57 of air hose adapter 21 to the exit hose 94 of a dual gauge leak tester 12. The dual gauge tester 12 is then connected to a compressed air source, such as a compressor 96. In this manner, device 10 is connected directly to the leak tester 12 and indirectly to a pressurized air source, such as a compressor 96.
Once said connection is completed, the leak down test is performed in the same manner it is performed when using a dual leak down tester regularly: the amount or percentage of incoming air pressure from the compressed air source is adjusted and predetermined using the first gauge of the tester 12, and the pressurized air coming from the tester 12 is allowed to enter to the cylinder 15 through device 10; the percentage of air pressure escaping from inside cylinder 15 is measured by the second gauge of tester 12 as a consequence of any leakage,—if any— in the cylinder that are due to or taking place in exclusively the cylinder walls, piston or the rings of the piston, in other words, in any area under the lower section of the cylinder block.
Finally, while the present invention has been described in terms of particular embodiments and applications, in both summarized and detailed forms, it will be understood that many substitutions, changes and variations in the described embodiments, applications and details of the novel tool illustrated herein and of its operation can be made by those skilled in the art to adapt it to various usages and conditions, without departing from the spirit of this invention. As such, these changes and modifications are properly, equitably, and intended to be within the full range of equivalence of the followings. While the invention has been described in conjunction with some embodiments, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art considering the forgoing description. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations falling within the spirit and scope of the appended claims.
