WO1998036158A1

WO1998036158A1 - Distribution system for otto cycle engines with the presence of only one valve in the combustion chamber

Info

Publication number: WO1998036158A1
Application number: PCT/IT1998/000022
Authority: WO
Inventors: Riccardo Paroni
Original assignee: CARRARO STENI
Current assignee: CARRARO STENI
Priority date: 1997-02-14
Filing date: 1998-02-12
Publication date: 1998-08-20
Anticipated expiration: 1999-08-14
Also published as: ITPD970029A1; IT1291416B1

Abstract

A new distribution system for otto cycle engines which foresees the presence of only one mushroom valve into the ceiling of the combustion chamber. This lonely valve is coupled to a second rotating valve which connects the gateway of the mushroom valve by turning with the aspiration gate and the draining pipe. The mushroom valve, which is delayed by an equalizer, opens and closes the gateway from and to the combustion chamber with its well known axial alterning movement.

Description

DESCRIPTION

DISTRIBUTION SYSTEM FOR OTTO CYCLE ENGINES

WITH THE PRESENCE OF ONL Y ONE VAL VE IN THE

COMBUSTION CHAMBER

The actual patent make reference to endothermic engines.

Particularly refers to four stroke petrol engine with alternate movement of piston and suction and draining on head.

Specifically the patent describes a particular new system of suction and draining of gas.

In the engine field many are been the endeavors to improve the intake of gas in the cylinder and following expulsion.

So they are carried out engine with three, four or more valves per cylinder and provided of turbo-compressor. In the turbo-compressor engines are tried to replace the normal gas flowing of fuel mixture with a forcing through turbo-compressor activates in various way as draining gas.

Into engines with more valves per cylinder are tried to improve the filling and the emptying of cylinder, increasing the number of gateway of combustible gas and fuel mixture; in fact in everyone of the two moments of pouring are available more than a valve.

The kind of engine above-mentioned presents many drawbacks: the system with several valves per cylinder have got greater bores and they needs of numerous motion and more parts than a normal engine with consequent problems of setting-up, possibility of breakage, wears and tears, and so on and again they always uses half of head of the cylinder for the filling passage; the turbo compressor system needs of turbines and compressors wliich requires registration and they feels the effects of draining gas high temperature. However there's to considerate that the traditional systems of distribution are subjected to breakage of the springs of valves, hysteresis, high velocity in opening and closing action of the valves, irregular heating of head of the cylinder (draining valves are hotter then suction valves). To obviate to all above mentioned drawbacks it is studied and carried out a new system of distribution of filling of fuel mixture and expulsion of exhaust gas.

The new system of distribution foresees the presence of only one mushroom valve into the ceiling of the combustion chamber; this lonely valve is coupled to a second rotating valve which connects the getaway of the mushroom valve by Irirning with the aspiration gate and the draining pipe.

Both the mushroom valve and the rotating valve are mechanically linked so there is a perfect synchronism in both movement. Here following is minutely described the function. The mushroom valve is a well know stem valve with widening end to disk. The disk end of the valve has maximum size consented by the ceiling of the combustion chamber and the accessories as spark plug and the like. The mushroom valve opens and closes the gateway from and to the combustion chamber with its well known assial alternating movement. This valve is lacking in of springs and is delayed by an equalizer which causes both its opening and its closing. The end of tl e stem of tlie mushroom valve is bonded in a middle point of the equalizer in die way that the vertical oscillation of the equalizer brings up and down the valve. Particularly the connection between the equalizer and the stem of the mushroom valve permits a side transfer but prevents any vertical transfer between stem and equalizer. The end of the equalizer is brought up and down by a special cam described later. The rotating valve is comparable to an upsetting glass that is:

- is substantially formed by an hollow cylinder which opening on its circular surface is direct to the combustion chamber;

- it has an opening on the lateral surface;

- the other circular surface of the glass (the bottom) presents a toothed conical crown and the central hole to receive the stem or a guide to receive the stem of the mushroom valve. The rotating valve is located on the head , over and around the mushroom valve or coaxial it. So that the stem of the mushroom valve can run in the hole or in the guide presents on the "close" circular surface and in the way that the opening circular surface is directed to the circular head of tlie mushroom valve and communicates with it.

The cylindrical surface of the housing slot of the rotating valve presents two holes in positions and dimension that the hole on the cylindrical surface of the rotating valve during its rotation lines up exactly with them.

These two holes into housing slot are connected respectively to the suction pipe and the draining pipe.

Substantially the rotating valve establishes the communications between the suction or the draining pipe with the mushroom valve and so the combustion chamber.

A toothed wheel with conical gear is set in perpendicular position to the rotating valve and engages the conical toothed crown of the rotating valve. Over one of the circular surfaces of the toothed wheel there is a groove like a polycentric ring, that is a cam, in which there is the end of the equalizer.

The toothed wheel is put in rotation thanks to means like a chain, toothed driving belt, gear etc. connected with the crankshaft so there is a perfect correspondence between toothed wheel angular position and working phase of the motor.

The rotation of the toothed wheel establishes the movement of the equalizer and then the closing of musliroom valve and the rotation of the rotating valve. In particular the special structure of the groove like polycentric ring of the toothed wheel establishes the opening and the closing time of the mushroom valve.

In the same way the angular width of each hole of the cylindrical housing slot of mushroom valve, the angular position between them and the angular width of the hole of the lateral surface of the rotating valve establishes suction and draining phases. Substantially the mushroom valve acts both like suction and draining valve, and its function are obtained through the rotating valve. The operating phases can be summed up in this way:

- the rotating valve turns and its lateral opening lines up with the opening of the suction pipe, the mushroom valve opens itself and the piston goes down to lower standstill sucks the fuel mixture which comes through the rotating valve and the mushroom valve; - the rotating valve continues the rotation bringing its lateral holes off suction and draining pipes, the musliroom valve closes and the piston begin the run of compression.

- near the superior standstill happens the explosion of the mixture and the piston descends for the expansion phase. The mushroom valve remain close and the rotating valve continues into its rotation without its lateral openings meets the Graining pipe.

- the rotating valve continues its rotation up to take its lateral surface to tlie draining pipe, the mushroom valve begins opening and the piston, coming up push out the draining gas. - the cycle restart with the mushroom valve which remain open, the rotation valve which lines up its lateral hole with the suction pipe and the piston which goes down sucking the fuel mixture. The distribution flow system how is over described permits the utilization of largest dimension of pipes or the utilization of the same mushroom valve for every flow phases. Into other words there's an improvement of efficiency of decanting of gas in and out and the filling coefficient of the cylinder to obtain better results is suitable that the distance between the lateral hole and the hole on the circular surface would be the less possible so to reduce the part of gas that stays between the valves during the operating phases.

The advantages of this system are given to the fact that thanks the increased capability of breathing, which can obtain good performance also with long run engines and/or with larger unitary swept volume because of the parity of total swept volume decreases the ratio surface/volume of combustion chamber and therefore lowest calorie conveyed to the cooler circuit and the remarkable thermodynamic yield.

Moreover the mushroom valves carries out the double function to keep at smaller temperature and to increase its duration. The new distribution system described does not utilize springs of recall which are susceptible of breakage and enervated, the mushroom valve opens and closes itself with lower frequency, tlie temperature on the head of the engine, and particularly near the ceiling of the combustion chamber, results more uniform because the fuel mixture and exhaust gas passes through the same mushroom valve and the same rotating valve.

This new system can be applied both to new and old engines simply changing the head. This system permits applications to all the types "otto cyele " of every swept volume and number of cylinder. The head results of simpler realization because existing of only one valve, in preference with vertical axis, all processing post fusion results greatly simplified and reduced.

The wears and tears and the thermal expansion due to the use, bring to the opportunity to foresee also some systems of recovery of clearances, as for example an adjustment spring or hydraulic systems.

The system results composed by a lower number of components than already known engines both of two and four strokes with clear and maintenance advantages.

The length and width of tubes don't result bindings by the extreme number of valves of the present technique with advantage for sliding fluency of gas.

In the enclosed plates it is presented, with the exemplifying and not limiting purpose, a practice realization of the invention.

The figures 1 and 2 represent two vertical sections, orthogonal each other, of the head of the engine provided with the new distribution system.

The mushroom valve (1) has the maximum dimension allowed by the ceiling of the combustion chamber and by the accessories parts like sparking plugs and similar. The end of the mushroom valve stem (1) is bound to a middle point of the equalizer (2) provided with a revolving element so the equalizer's vertical oscillation (2) lifts and lowers the mushroom valve (1) the equalizer (2) head (2-1) is left and lowered by an appropriate cam (6-2) later described.

It's possible to compare the rotating valve (3) to a glass turned upside down endowed with an opening (3-3) on the lateral surface and with a conical crown (3-1) and a central hole (3-2) on the "glass bottom".

This central hole (3) receives tlie stem of the valve (1) or a guide for tlie stem of the valve (1).

The rotating valve (3) is located on the head over and around the mushroom valve (1), that is coaxial it so that the stem of the mushroom valve (1) can run in the hole or in tlie guide presents on die "close" circular surface and in the way that tlie opening circular surface of the rotating valve (3) is directed to the circular head of the mushroom valve (1) and communicates with it.

The cylindrical surface of the housing slot of the rotating valve presents two holes (4,5) in positions and sizes that the hole (3-3) on the lateral surface (3) of the rotating valve during its rotation lines up exactly with them.

These two holes (4,5) of the cylindrical place are linked respectively to the suction pipe and the draining pipe. A toothed wheel (6) with a conic set of teeth (6-1) is located in perpendicular position to the rotating valve(3) and engages its toothed crown (6) is present a groove (6-2) like a polycentric ring, that is a cam in which is placed the end (2-1) of the equalizer (2).

The toothed wheel (6) is put in rotation by the movement units, as shaft or toothed wheel, connected with the engine shaft so that there is a perfect correspondence between toothed wheel angular position and working phase of the motor.

The groove particular structure (6,2) like a polycentric ring of the toothed wheel (6) determines tlie sense o timing of opening, closing and staying during mushroom valve opening and closing (1) whereas the angular breadth of everyone opening (4,5) of cylindrical place of the rotating valve (3), the angular position between the said openings (4,5) and the opening angular width (3-3) on the valve lateral surface (3) cause the suction and draining phases. In the picture, from 3 to 8, are shown the main moments of the engine and the new distribution system function cycle:

- the rotating valve (3) turns and its lateral opening (3-3) lines up with the suction tube opening (4), the mushroom valve (1) opens and the piston (7) goes down to the lower standstill sucking the fuel mixture which passes through the rotating valve (3) and the mushroom valve (1);

- the rotating valve (3) continues its rotation taking its lateral opening (3-3) out from the suction and draining openings (4,5), the mushroom valve (1) closes itself . and the piston (7) starts the compression phase;

- near the superior standstill happens the explosion of the mixture and the piston (7) descends for the expansion phase to the lower standstill; the mushroom valve (1) remains closed and the rotating valve (1) continues into its rotation without its lateral opening (3-3) meets the suction pipe (4) or the draining pipe (5). - the rotating valve continues its rotation up to take its lateral opening (3-3) to correspond to the draining pipe(5), the mushroom valve (1) opens and the piston (7), going back up, pushes the exhaust gas into the draining pipe(5) through the mushroom valve (1) and the rotating valve inner cavity (3);

- the cycle restarts with tlie mushroom valve (1) which remains open, tlie rotating valve (3) which lines up its lateral opening (3-3) with the suction pipe (4) and with the piston (7) which goes down sucking the fuel mixture. These are the schematic formality sufficient to the expert person to reahze the project, consequently, for the real application there could be some variation without bringing changes to the innovative concept essence. Therefore with a reference to the previous description and to the plates enclosed it is expressed the following claims.

Claims

1. System of distribution for engines of otto cycle characterized by the fact to be constructed by a mushroom valve which has a movement of translation with a rotating valve like a turned upside down glass with a lateral opening and toothed wheels over itself, and where the lateral opening of that rotating valve is lined up by turns with the suction pipe and with the draining pipe.

2. System of distribution as by claims 1, characterized by the fact that the rotating valve engages a toothed wheel linked in stroke with engines rotating parts and where the mushroom valve is left and lowered by an equalizer which end runs through a cam present in d e toothed wheel which engages the rotating valve toothed crown.

3. System of distribution as by claims 1, characterized by the fact diat the engine and the new system distribution's function cycle suggest that:

- the rotating valve turns and its lateral opening lines up with the suction tube opening, the mushroom valve opens and the piston goes down to tl e lower standstill sucking the fuel mixture which passes through the rotating valve and the mushroom valve - the rotating valve continues its rotation taking its lateral opening out from the suction and draining openings , the mushroom valve closes itself and the piston starts the compression phase;

- near the superior stand still happens the explosion of the fuel mixture and the piston descends for the expansion phase to the lower standstill; the mushroom valve remains closed and the rotating valve continues into its rotation without its lateral opening meets the suction pipe or the oxaining pipe .

- the rotating valve continues its rotation up to take its lateral opening to correspond to the draining pipe, the mushroom valve opens and the piston , going back up, pushes the exhaust gas into the oraining pipe tlirough the musliroom valve and the rotating valve inner cavity ;

- the cycle restarts with the musliroom valve wliich remains open, the rotating valve which lines up its lateral opening with the suction pipe and with the piston which goes down sucking the fuel mixture.