| Title of Invention | CYLINDER HEAD ASSEMBLY WITH SPARK PLUG HOUSING |
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| Abstract | A cylinder head assembly 100 for a spark ignited internal combustion engine, which includes a housing 110 for a first spark plug 102, is described. A first end of a connector 200 is attached to a terminal end of the first spark plug 102. A high tension (HT) cable 202 is electrically connected to a second end of the connector 200. The housing 110 encloses the connector 200, and is designed to extend over a substantial portion of the terminal end of the first spark plug 102. A flange 204 is provided to attach the housing 110 to the cylinder head 104, thus making the housing a single piece. An annular ring 208 is placed below the flange 204 to securely grip the cylinder head 104. |
| Full Text | TECHNICAL FIELD The present subject matter, in general, relates to a spark ignited internal combustion engine and in particular relates to a cylinder head assembly of a spark ignited internal combustion engine. BACKGROUND Conventionally, one spark plug per cylinder has been used in small capacity internal combustion engines. To achieve better drivability in such engines, a comparatively richer air fuel mixture is required which results in higher emissions and high fuel consumption. Further, using a lean air fuel mixture in such an arrangement results in loss of power and drivability as proper combustion does not take place, overcome this difficulty, two spark plugs are being employed in such engines. However, for small capacity engines, an arrangement comprising of two spark plugs has a few inherent problems associated with it. One problem associated with this arrangement is with respect to the placement of the additional spark plug. In case of small capacity engines, the additional spark plug has to be introduced into the cylinder head from the cam-chain chamber side. In such a case, the extra spark plug has to be protected from chain interference, high temperature, oil, etc. Further, the opening on the cam-chain chamber side also requires a sealing means to prevent seepage of oil from the cam-chain chamber to the outer surface of the cylinder head and to avoid ingress of environmental particulate matter into the cam-chain chamber. SUMMARY The subject matter described herein is directed towards a cylinder head assembly with a housing for at least one of a plurality of spark plugs. According to one aspect of the present subject matter, the cylinder head assembly has a cylinder head that includes a housing enclosing a connector. The bottom end of the connector is connected to a terminal end of a first spark plug. Further, the bottom end of the housing extends over a substantial length of the terminal end of the first spark plug. A high tension (HT) cable electrically connects the top end of the connector with an ignition coil. 1 he housing, which is a single piece unit, thus encloses the connector and extends on both sides of the connector. The housing is attached to the cylinder head through a flange by at least one connecting means. The present subject matter facilitates the usage of a plurality of spark plugs, which can be installed in an internal combustion engine. Further, the present subject matter facilitates the protection of the terminal end of the first spark plug from high temperature and oil. Moreover, the present subject matter provides ease in serviceability and thus maintenance of the spark plugs. These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This Summary is provided to introduce a selection of concepts in a simplified form. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS The above and other features, aspects, and advantages of a cylinder head assembly will be better understood with regard to the following description, appended claims, and accompanying drawings where: Fig. 1 provides a cross sectional view of a cylinder head assembly according to one embodiment of the present subject matter. Fig. 2 illustrates a cross sectional view of the spark plug assembly according to another embodiment of the present subject matter. DESCRIPTION The present subject matter discloses a cylinder head assembly that includes a housing for at least one of a plurality of spark plugs for a spark ignited internal combustion engine. For the purpose of description, the subject matter as described herein includes a cylinder head assembly with two spark plugs. A first spark plug is housed in the cylinder head through an opening, at a side where a cam-chain chamber is housed, in the cylinder head assembly. The first spark plug is provided in such a way that a terminal end of the first spark plug is disposed substantially in the middle of the cam-chain chamber. The cam-chain chamber includes an endless chain, a cam shaft sprocket, and a crankshaft sprocket such that both the sprockets are disposed at two opposite ends of the cam-chain chamber. This arrangement facilitates a rotational force being transferred from the crankshaft sprocket to the camshaft sprocket through the endless chain disposed over the sprockets. Both the sprockets are designed in such a way that the endless chain disposed over them has no interference with the first spark plug. Further, the tip of the first spark plug is disposed in a combustion chamber of the internal combustion engine. The terminal end of the first spark plug is connected to the bottom end of a connector. The connector receives a high tension (HT) electric cable at the top end. The connector is housed in a housing of the cylinder head assembly. The housing extends on both sides of the connector such that the housing covers a substantial portion of the terminal end of the first spark plug at the bottom end of the connector and the cable at the top end of the connector. Thus, the housing act as a housing for the first spark plug. Additionally, an annular ring made up of an elastomer is provided to secure a grip between the housing and the opening on the cylinder head where the housing is disposed. Further, the cylinder head assembly employs a rubber grommet to shield the first spark plug from high temperature and oil. Such a cylinder head assembly provides for placement of a plurality of spark plugs in a small capacity engine. The arrangement provides housing to the connector extending to the terminal portion of the first spark plug. The housing as described here also serves to implement other features, such as an oil tight cover for the spark plug and a cap for blocking the opening on the other side of the cylinder head, which would otherwise be implemented by way of additional components. Fig. 1 shows a cross-sectional view of the cylinder head assembly 100 of an internal combustion engine according to one embodiment of the present subject matter. A terminal end of a first spark plug 102 is housed in a cylinder head 104 on a cam-chain chamber side of the cylinder head 104. The first spark plug 102 is housed through an opening on a side wall of a cam-chain chamber 106 that extends through the cylinder head 104. The tip of the first spark plug 102 extends into a combustion chamber of the internal combustion engine. A second spark plug 108 is disposed diametrically opposite to the first spark plug 102 and is on the other side of the cam-chain chamber side. The second spark plug 108 has its tip disposed in the combustion chamber and a terminal end disposed in the cylinder head 104. As shown in Fig. 1, the first spark plug 102 is disposed in the cam-chain chamber side of the cylinder head 104 where the first spark plug 102 passes through an opening in the cam-chain chamber 106 and extends into the combustion chamber. The first spark plug 102 is installed in such a way that the terminal end of the first spark plug 102 is substantially disposed in the cylinder head 104 through the opening in the cam-chain chamber 106 while the tip end of the first spark plug 102 is disposed in the combustion chamber. As is shown, the cylinder head 104 includes a housing 110 for the first spark plug 102. Further, a drain hole 112 is provided in close proximity to the first spark plug 102, at the bottom corner of the cylinder head 104, to drain the accumulated oil and environmental particulate matter. The second spark plug 108 is placed on the opposite side of the cam chain chamber side. The tip of the second spark plug 108 is in the combustion chamber and the terminal is disposed in the cylinder head 104. Although not shown in this embodiment, it will be understood that a housing similar to the housing 110 can be used for the second spark plug 108 also. Fig 2 shows a cross sectional views of a spark plug assembly according to an embodiment of the present subject matter. A connector 200, which is a hollow cylindrical body, is attached to the terminal end of the first spark plug 102 at the bottom end. Further, a cable, preferably a high tension (HT) cable 202, is electrically connected to a top end of the connecter 200. A first end of the housing 110 fits closely over a substantial length of the terminal end of the first spark plug 102. The housing 110 encloses the connector 200 and fits firmly thereon to receive the HT cable 202 on a second end of the housing 110. The HT cable 202 that protrudes from the housing 110 is further connected to an ignition coil (not shown in the figure). In addition. Fig 2 shows flanges 204 that are provided on the housing 110 to fasten the housing 110 to the cylinder head 104. In one implementation, mounting screws 205 are used to fasten the housing 110 through the flanges 204 to the cam-chain chamber side of the cylinder head 104. Thus the housing acts as a single piece. An annular ring 208 provided below the flange section of the housing 110. This annular ring 208 is made of an elastomeric substance. The annular ring 208 is provided with serrations to securely grip the housing 110 and the opening on the cam chamber side of the cylinder head 104. Further, a high temperature and oil resistant rubber grommet 206 is closely fitted over a first end of the housing 110 and partially extends over the terminal end of the first spark plug 102. The rubber grommet 206 is used to shield the housing 110 from heat as well as oil and thereby prolong the lifespan of the spark plug. Thus, the housing 110 incorporates multiple features in addition to providing a housing for the connector 200 and the first spark plug 102, such as an oil tight cover for the first spark plug 102 and a cap for blocking the hole on the top side of the opening. The housing 110 further acts as a seal to prevent seepage of oil from the cam-chain chamber 106 and protects the first spark plug 102 from oil and particulate deposition. This cylinder head assembly 100 arrangement also facilitates the provision of non-interference of the endless chain (not shown) running over the camshaft sprocket (not shown) and the crankshaft sprocket (not shown) with the first spark plug . The aforementioned embodiments of the subject matter and equivalents thereof have many advantages, including those which are described below. The cylinder head assembly as described herein advantageously facilitates placement of an extra spark plug in a small capacity internal combustion engine. The cylinder head assembly 100 allows the designing of sprockets in such a way that the endless chain, running over the sprockets, has no interference with the spark plug. Also, the terminal ends of the first spark plug 102 and second spark plug 108 are protected from high temperature and oil. Any oil and environmental particles that seep into the cylinder head assembly 100 are drained out through the drain hole 112 on the bottom corner of the cylinder head 104. The cylinder head assembly 102 also prevents seepage of oil from the cam-chain chamber 106 by acting as an oil seal. In addition to the above advantages, the present subject matter provides ease in serviceability or maintenance of spark plugs. The combination of all such aspects when taken together reduces the magnitude of labor and costs involved. Therefore, as a whole, the overall performance of the small capacity spark ignited internal combustion engine is enhanced. Although the subject matter has been described in considerable details with reference to certain preferred embodiment thereof, other embodiments are possible. As such, the sprit and scope of appended claims should not be limited to the description of the preferred embodiments contained therein. I/We claim: 1. A cylinder head assembly (100) for a spark ignited internal combustion engine, said cylinder head assembly comprising: a cylinder head (104); a plurality of spark plugs mounted on said cylinder head (104), wherein a first spark plug (102) of said plurality of spark plugs is mounted on said cylinder head (104) through an opening of a cam-chain chamber (106); a connector (200), wherein a bottom end of said connector (200) is connected to a terminal end of said first spark plug (102); and a housing (110); characterized in that said housing (110) encloses said connector (200) and a substantial portion of said first spark plug (102), wherein said substantial portion of said first spark plug (102) includes said terminal end of said first spark plug (102), and wherein said housing (110) is attached to said cylinder head (104) through a flange (204) by at least one connecting means. 2. The cylinder head assembly (100) as claimed in claim 1, wherein said housing (110) is a single piece unit. 3. The cylinder head assembly (100) as claimed in claim 1, wherein said terminal end of said first spark plug (102) extends through said opening of said cam-chain chamber (106). 4. The cylinder head assembly (100) as claimed in claim K wherein said housing (110) includes an opening for receiving a cable to be attached on a top end of said connector (200). 5. The cylinder head assembly (100) as claimed in claim 1, wherein said housing (110) extends through said opening of said cam-chain chamber (106). 6. The cylinder head assembly (100) as claimed in claim 1, wherein said connecting means are screws (205). 7. The cylinder head assembly (100) as claimed in claim 1 further comprises a rubber grommet (206) fitted over a bottom end of said housing (110), wherein said rubber grommet (206) extends over a part of said housing (110). 8. The cylinder head assembly (100) as claimed in claim 1 further comprising an annular ring (208) attached on said housing (110) below said flange (204). 9. The cylinder head assembly (100) as claimed in claim 1, wherein a drain hole (112) is provided adjacent to said first spark plug (102) at the bottom of the cylinder head (104). 10. The cylinder head assembly (100) as claimed in claim 1, wherein the housing (110) is made up of an electrical and thermal insulating material. |
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| Patent Number | 277954 | ||||||||||||||||||
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| Indian Patent Application Number | 1901/CHE/2007 | ||||||||||||||||||
| PG Journal Number | 51/2016 | ||||||||||||||||||
| Publication Date | 09-Dec-2016 | ||||||||||||||||||
| Grant Date | 07-Dec-2016 | ||||||||||||||||||
| Date of Filing | 24-Aug-2007 | ||||||||||||||||||
| Name of Patentee | TVS MOTOR COMPANY LIMITED | ||||||||||||||||||
| Applicant Address | JAYALAKSHMI ESTATE, 24 (OLD #8), HADDOWS ROAD, CHENNAI - 600 006 | ||||||||||||||||||
Inventors:
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| PCT International Classification Number | F02D | ||||||||||||||||||
| PCT International Application Number | N/A | ||||||||||||||||||
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