FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
"TWIN HELICAL INTAKE PORT" APPLICANT
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Kannappachetty Veeramani, Makarand Shrikrishna Kulkarni,
Subhash Chandrbhan Kale
All Indian national
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION The following specification describes the invention
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Field of Invention
The present invention relates to intake ports of an internal combustion engine. The present invention particularly relates to helically-shaped intake ports of an internal combustion engine. Background
Generally in case of compression-ignition type internal combustion engines, an intake port comprising a substantially straight inlet passage portion and a typical helical portion is used in order to create a swirling air motion in the combustion chamber of the engine during intake stroke. However, in case of such helical intake ports, where one of the passage is helical and the other passage is tangential to the helical passage, wherein the generation of swirl is by infringement of the air set out of the valve gap to the cylinder wall, it is obvious that the generated swirl strongly depends on the angle between cylinder wall and air set and, consequently further on the port positioning as well as direction and shape of the runner part of port. Also the sharp edge which is generated by the port contour and control cutter influences the directed outflow from the port. Hence tangential ports are very sensitive against casting displacements.
There is therefore a need for providing a helical intake port that overcomes the above said defects. Object of the invention
An object of the present invention is to provide a helically-shaped intake port for an internal combustion engine with two helical passages.
Another object of the present invention is to provide a helically-shaped intake port for an internal combustion engine that is less sensitive against casting displacements.
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Yet another object of the present invention is to provide a helically-shaped intake port for an internal combustion engine that is more robust in construction.
Yet another object of the present invention is to provide a helically-shaped intake port for an internal combustion engine that enhances the engine maximum output torque.
Still another object of the present invention is to provide a helically-shaped intake port for an internal combustion engine that keeps the engine drivability high.
Further object of the present invention is to provide a helically-shaped intake port for an internal combustion engine with no compensation incase of swirl effects.
Various modifications of the disclosed objects, as well as alternate objects of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.
Description
The helically-shaped intake port 100 as shown in Fig.l with respect to one embodiment of the present invention comprises a typical passage helical port 110 and an atypical passage helical port 120. Such a double helical port 110 & 120 is less sensitive against casting displacement. The typical passage helical port 110 mainly produces the swirling air motion inside the intake port 100. Therefore the achieved swirl is quite independent from valve position in relationship to the cylinder centre. Also the swirl ratio over valve lift is almost constant.
Atypical helical port 120 has got unusual shape due to disadvantageous helix position. Thereby intake air that is getting mixed by way of these two helical passage ports 110 & 120 are more efficient and produces a desirable swirl effect. A fuel injector
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140 that is tangential to the head of helical intake ports supplies fuel thereby enabling better air-fuel mixture. Also seen is a glow plug 130 that helps in heating up of combustion chamber of the engine in cold condition for better start-up ignition. Helical intake ports 100 are mounted on to the engine cylinder head (not shown in Figure) by means of mountings 150.
The helically-shaped intake port 100 as shown in the cross-sectional view in Fig.2 with respect to one embodiment of the present invention shows the section of head portion of typical passage helical port 110 and atypical passage helical port 120 aligned one after the other, wherein both the helical ports 110 & 120 are separated by a dividing bulkhead or wall (not seen in Figure) where the glow plug is positioned. Thus a robust construction is achieved for the helical intake ports 100 with no casting displacements.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.
Dated this 18th Day of June 2007

T SRINIVASAN AGENT FOR THE APPLICANT
To
The Controller of Patents
The Patent office at Mumbai
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