Patent Publication Number: US-2023137241-A1

Title: Internal combustion engine

Description:
BACKGROUND 
     Field of the Invention 
     The present invention generally relates to an internal combustion engine. More specifically, the present invention relates to an internal combustion engine having a plurality of piston rings. 
     Background Information 
     Piston rings seal are provided to internal combustion engine cylinders so that combustion gas generated at the time of ignition does not leak into the opening between the piston and the cylinder. The piston moves inside the engine at a rate of several thousand times per minute. Therefore, a small amount of oil is provided over the pistons so they move smoothly, with little friction between metal and metal. When gas ignition takes place, the temperature inside a piston reaches a very high heat. Piston rings can release heat build-up by dissipating the heat to the cylinder. Piston rings support pistons to allow for movement of the piston. 
     SUMMARY 
     In view of the state of the known technology, one aspect of the present disclosure is to provide an internal combustion engine comprises a combustion chamber, a piston a plurality of piston rings. The combustion chamber has a bore wall. The piston is configured to move relative to the bore wall. The plurality of piston rings is provided to the piston. Each of the piston rings has a main body that is circular. Each of the pistons rings further has a stopper that protrudes from the main body. 
     Also other objects, features, aspects and advantages of the disclosed internal combustion engine will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses one embodiment of the internal combustion engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the attached drawings which form a part of this original disclosure: 
         FIG.  1    is a schematic side view of a vehicle equipped with an internal combustion engine; 
         FIG.  2    is a side view of a piston of the internal combustion engine of  FIG.  1   ; 
         FIG.  3    is a series of cross-sectional views of the internal combustion engine with a plurality of piston rings; 
         FIG.  4    is a series of cross-sectional views similar to  FIG.  3    but the piston rings do not include stoppers; 
         FIG.  5    is an exploded view of the piston rings and the piston; 
         FIG.  6    is a schematic diagrammatic view of a representative piston ring of the piston rings; 
         FIG.  7    is a side view of a modified piston that can be provided to the internal combustion engine; 
         FIG.  8    is a schematic diagrammatic view of a representative modified piston ring of modified piston rings for the modified piston; and 
         FIG.  9    is a series of cross-sectional views of the modified piston and the piston rings. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Selected embodiments will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
     Referring initially to  FIG.  1   , a vehicle  10  is provided with an internal combustion engine  12 . The internal combustion engine  12  is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion. A internal combustion engine  12  can be a spark-ignited internal combustion engine  12 , or a compression-ignited systems. In a spark-ignited combustion engine, the fuel is injected into a combustion chamber  14  and combined with air to create combustion. The expansion of high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. This combustion force is applied to one or more pistons, turbine blades, a rotor, or a nozzle. 
     Therefore, the internal combustion of the illustrated embodiment comprises a combustion chamber  14  and a piston  16 . In the illustrated embodiment, the internal combustion engine  12  further comprises a plurality of piston rings  18  that are provided to the piston  16 . 
     As best seen in  FIGS.  2  and  3   , the combustion chamber  14  has a bore wall  20  (e.g., a cylinder wall) that defines the internal space of the combustion chamber  14 . In particular, the bore wall  20  defines an inner diameter of the combustion chamber  14 . The gas pressure in the combustion chamber  14  exerts a force on the piston  16 . The piston  16  is configured to move relative to the bore wall  20  along a center axis A, as shown in  FIG.  5   . 
     The piston rings  18  are fitted around the piston  16  to prevent the gases from leaking into the crankcase or the oil leaking into the combustion chamber  14 . In particular, the piston rings  18  include a first ring  22  that is a top ring, a second ring  24  that is a middle ring and a third ring  26  that is a bottom ring. The piston rings  18  operate move with the piston  16  to reduce blowby gases from escaping into the combustion chamber  14 . The piston rings  18  are further provided to the piston  16  to maintain a desired lubrication for the piston’s  16  movement inside the combustion chamber  14 . 
     As seen in  FIG.  6   , each of the piston rings  18  has a main body B that is circular. The circular main body B is fitted around the piston  16 . As best seen in  FIG.  5   , the main body B of each of the piston rings  18  includes an installation gap G that is needed to enable free expansion of the piston rings  18  due to rising temperature inside the combustion chamber  14  during operation. Therefore, the piston rings  18  are premade with installation gaps G, as will be further described below. In the illustrated embodiment,  FIG.  6    diagrammatically represents each of the piston rings  18 . 
     The installation gaps G basically define a space at around half a millimeters on the respective main body B to enable expansion of the main bodies due to increased temperature in the combustion chamber  14 . The installation gaps G are preferably formed as breaks along the circumference of the piston rings  18 . It will be apparent to those skilled in the vehicle field from this disclosure that the installation gaps G can have different sizes, shapes and configurations (e.g., ridges, steps, etc.) as needed and/or desired. 
     During movement of the piston  16 , the piston rings  18  can rotate along the piston  16  such that the installation gaps G become vertically aligned along the piston ring  28 . As a result, the vertical alignment of the installation gaps G results in unwanted blowby gases escaping through the space created by the aligned installation gaps G. Additionally, rotation of the piston rings  18  during piston  16  movement impedes the lubricating effect of the piston rings  18 . In particular, the continuous movement of the piston rings  18  along the piston  16  creates friction between the piston rings  18  and the bore wall  20 , which reduces the lubricating effect of the piston rings  18 . 
     In view of the above, the piston rings  18  are provided with stoppers S that fittedly engage with the piston  16  in order to prevent rotational movement of the piston rings  18  on the piston  16 . That is, each of the piston  16  rings has a stopper S that protrudes from a respective main body, as will be further described below. Additionally, the piston  16  includes a plurality of grooves that receive the piston rings  18 , as best seen in  FIGS.  3  to  5   . 
     That is, each of the piston grooves  30  includes a recess  32  that engage with a respective one of the stoppers S. Therefore, the piston  16  includes a plurality  32  of recesses that fittedly receive the stoppers S of the plurality of piston rings  18 . In other words, the piston  16  of the illustrated embodiment is made with a plurality of recesses  32  that receive the stoppers S therein to retain the piston rings  18  in place, as will be described below. 
     Referring to  FIGS.  3  to  6   , the first ring  22  functions as a sealing ring. That is, the first ring  22  functions to seal against blowby gases crossing into the combustion chamber  14 . Therefore, the first ring  22  presses tightly against the bore wall  20  and in order to seal the combustion chamber  14  so to keeping combustion gases from escaping. The first ring  22  is a topmost ring of the piston rings  18  along the piston  16 . The first ring  22  is preferably made of a steel alloy that can be made from coiling a single elongated metal strip around a mandrel. The first ring  22  is made to withstand the high temperatures of the internal combustion engine  12 . 
     The first ring  22  includes a first main body  22 A that is fitted around the piston  16 . The first main body  22 A has a first gap  22 B. The first ring  22  further includes a first stopper  22 C that protrudes from the first main body  22 A at a location circumferentially offset of the first gap  22 B. In the illustrated embodiment, the first ring  22  can be made such that the first main body  22 A is coiled with the first stopper  22 C integrally formed thereon. That is, the first stopper  22 C is preferably also a steel alloy that is integrally made with the first main body  22 A. 
     As best seen in  FIGS.  5  and  6   , the first stopper  22 C and the first gap  22 B are circumferentially offset with respect to each other on the first main body  22 A. In particular, the first stopper  22 C and the first gap  22 B are preferably spaced at approximately 90 degrees apart in the circumferential direction along the first main body  22 A. 
     The piston rings  18  further includes a second ring  24  that functions as a temperature ring. That is, the second ring  24  can absorb the heat energy created during operation of the internal combustion engine  12  and operates to transfer the heat to the bore wall  20 . The second ring  24  is preferably made of a steel alloy that can be made from casting, such as by a pot casting method. For example, a short cylinder of an oval cross-section is made and the second ring  24  is then cut and machined from the cylinder. The second ring  24  can be casted as a homogeneous and balanced cast to form the circumference of the second ring  24 . 
     The second ring  24  includes a second main body  24 A that has a second gap  24 B. The second ring  24  further includes a second stopper  24 C. In the illustrated embodiment, the second ring  24  can be made such that the second main body  24 A is cast with the second stopper  24 C integrally formed thereon. That is, the second stopper  24 C is preferably also a steel alloy that is integrally made with the second main body  24 A. 
     The second stopper  24 C protrudes from the second main body  24 A at a location that is circumferentially offset of the second gap  24 B. In particular, the second stopper  24 C and the second gap  24 B are preferably spaced at approximately 90 degrees apart in the circumferential direction along the second main body  24 A. 
     As seen in  FIG.  5   , the second ring  24  is positioned on the piston  16  such that the second gap  24 B is circumferentially offset of the first gap  22 B along the center axis A of the piston  16 . Preferably, the first and second gaps  22 B and  24 B are offset by approximately 120 degrees in the circumferential direction of the piston  16 . The second stopper  24 C is also circumferentially offset of the first stopper  22 C along the center axis A of the piston  16 . In particular, the first and second stoppers  22 C and  24 C can be approximately 90 degrees offset with respect to each other in the circumferential direction of the piston  16 . The first and second stoppers  22 C and  24 C are only offset with respect to each other to retain the first and second gaps  22 B and  24 B in the aligned position. Therefore, it will be apparent to those skilled in the vehicle field from this disclosure that the positioning of the first and second stoppers  22 C and  24 C on the respective first and second main bodies can vary so long as the first and second gaps  22 B and  24 B are sufficiently unaligned to prevent leakages along the piston  16 . 
     The plurality of piston rings  18  includes a third ring  26  that is an oil ring. Therefore, the third ring  26  functions to scrap off the bore wall  20  as the piston  16  travels along the cylinder, depositing it back into an oil sump, as seen in  FIGS.  3  and  4   . The third ring  26  is preferably created by a coiling process that is similar to that of the first ring  22 . 
     As best seen in  FIG.  5   , the third ring  26  includes a third main body  26 A that has a third gap  26 B. The third ring  26  further includes a third stopper  26 C that protrudes from the third main body  26 A at a location circumferentially offset of the third gap  26 B. The third stopper  26 C is preferably a metal stopper that can be integrally formed with the metal coil of the third main body  26 A. The third stopper  26 C and the third gap  26 B are preferably approximately 90 degrees apart along the circumferential direction of the third main body  26 A, as seen in  FIGS.  5  and  6   . 
     The third ring  26  includes a fourth main body  28 A that has a fourth gap  28 B. The third ring  26  further includes a fourth stopper  28 C that protrudes from the fourth main body  28 A at a location circumferentially offset that is of the fourth gap  28 B. The fourth stopper  28 C is preferably a metal stopper that is integrally formed with the metal coil of the fourth main body  28 A. Therefore, the third ring  26  is defined by a pair of circular main bodies, the third and fourth main body  28 A that together define the oil ring. The fourth stopper  28 C and the fourth gap  28 B are preferably approximately 90 degrees apart along the circumferential direction of the fourth main body  28 A. 
     The third gap  26 B is circumferentially offset of the first and second gaps  22 B and  24 B along the center axis A of the piston  16 . The fourth gap  28 B is also circumferentially offset of the first, second and third gap  26 B s  along the center axis A of the piston  16 . As stated, in the illustrated embodiment, the first and second gaps  22 B and  24 B are preferably separated by approximately 120 degrees along the circumferential direction with respect to each other. In the illustrated embodiment, the third and fourth gap  28 B s  are preferably separated by approximately 120 degrees along the circumferential direction with respect to each other. 
     The third stopper  26 C is circumferentially offset of the first and second stoppers  22 C and  24 C along the center axis A of the piston  16  so that the first, second and third gaps  22 B,  24 B and  26 B do not become aligned during use. The fourth stopper  28 C is also circumferentially offset of the first, second and third stopper  22 C,  24 C and  26 C along the center axis A of the piston  16 . In this way, the first to fourth gaps  22 B,  24 B  26 B and  28 B do not become aligned along the piston  16  during movement of the piston  16  due to the positioning of the stoppers S that engage with the piston  16 . 
     It will be apparent to those skilled in the vehicle field from this disclosure that the positioning of the third and fourth stoppers  26 C and  28 C on the respective third and fourth rings  24  and  26  can vary so long as the third and fourth gaps  26 B and  28 B are sufficiently unaligned to prevent leakages along the piston  16 . Further, the first, second and third rings  22 ,  24  and  26  are provided on the piston  16  to maximize the unalignment angles of the first, second, third and fourth gaps  22 B,  24 B,  26 B and  28 B. 
     As best seen in  FIGS.  3  and  4   , the piston  16  includes a first groove  30 A that receives the first ring  22 . In particular, the first groove  30 A receives the first main body  22 A. The first groove  30 A includes a first recess  32 A that receives the first stopper  22 C therein. The first recess  32 A fittedly receives the first stopper  22 C such that the first stopper  22 C cannot become dislodged from the first recess  32 A as the piston  16  moves. 
     Similarly, the piston  16  further includes a second groove  30 B that receives the second ring  24 , with a corresponding second recess  32 B that receives the second stopper  24 C. The piston  16  further receives a third groove  30 C that receives the third ring  26  with corresponding third and fourth recesses  32 C and  32 D that receive the third and fourth stoppers  26 C and  28 C, respectively. The grooves  30  and the recesses  32  can be machinated on the piston  16  by conventional means. 
     Referring to  FIGS.  7  to  9   , a modified internal combustion engine  12  having a modified piston  116  and a plurality of modified piston rings  118  will now be described here. Due to the similarity between the internal combustion engine  12  and the modified internal combustion engine  112 , all corresponding components of the modified internal combustion engine  112  will receive the same reference numbers as the internal combustion engine  12  but increased by  100 . The modified piston rings  118  include modified first, second and third rings  122 ,  124  and  126  that are substantially identical the first, second and third rings  22 ,  24  and  26 . The only difference between the modified first, second and third rings  122 ,  124  and  126  and the first, second and third rings  22 ,  24  and 26sis that the modified first, second and third rings  122 ,  124  and  126  include modified stoppers  122 C,  124 C and  126 C and  128 C. 
     That is, the modified stoppers  122 C,  124 C and  126 C and  128 C are identical to the first, second, third and fourth stoppers  22 C,  24 C,  26 C and  28 C of the main embodiment except that the modified stoppers  122 C,  124 C and  126 C and  128 C include extended dimensions with respect to the first, second, third and fourth stopper 28Cs of the main embodiment. Additionally, the modified stoppers  122 C,  124 C and  126 C and  128 C are formed separately from the main bodies of the modified first, second and third rings  122 ,  124  and  126  and are subsequently adhered thereon, such as by welding. For example, the modified first, second, third and fourth stopper  122 C,  124 C,  126 C and  128 C can be metal plates that are welded to the main bodies of the modified first, second, third rings  122 ,  124  and  126 . Therefore, the modified stoppers  122 C,  124 C and  126 C and  128 C are not integrally formed with the rest of the piston rings  18 , as was described for the first, second and third rings  22 ,  24  and  26 . 
     The modified piston  16  includes modified recesses  132 A,  132 B,  132 C and  132 D that receive the elongated stoppers  122 C,  124 C,  126 C and  128 C of the modified first, second and third rings  122 ,  124  and  126 . Therefore, it will be apparent to those skilled in the vehicle field from this disclosure that the stoppers S can be modified to have different dimensions and that the recesses can be modified to have different dimensions to fittedly receive the stoppers S. 
     GENERAL INTERPRETATION OF TERMS 
     In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components and/or groups, but do not exclude the presence of other unstated features, elements, components and/or groups. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Also as used herein to describe the above embodiment(s), the following directional terms “forward”, “rearward”, “above”, “downward”, “vertical”, “horizontal”, “below” and “transverse” as well as any other similar directional terms refer to those directions of a vehicle equipped with the internal combustion engine. Accordingly, these terms, as utilized to describe the present invention should be interpreted relative to a vehicle equipped with the internal combustion engine. 
     The term “configured” as used herein to describe a component, section or part of a device includes hardware and/or software that is constructed and/or programmed to carry out the desired function. 
     The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. 
     While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, location or orientation of the various components can be changed as needed and/or desired. Components that are shown directly connected or contacting each other can have intermediate structures disposed between them. The functions of one element can be performed by two, and vice versa. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.