EP1781904B1

EP1781904B1 - Gas-distributing mechanical arrangement automatically changing injection and exhaust gas valve timing

Info

Publication number: EP1781904B1
Application number: EP05756022A
Authority: EP
Inventors: Arnis Treijs
Original assignee: MOTORCIKLS SIA
Current assignee: MOTORCIKLS SIA
Priority date: 2004-08-06
Filing date: 2005-06-16
Publication date: 2009-09-16
Anticipated expiration: 2025-06-16
Also published as: ATE443200T1; DE602005016691D1; WO2006014098A1; ES2333028T3; EP1781904A1; LV13238B

Abstract

The invention refers to the mechanical engineering industry, more properly to the internal combustion engine gas-distributing device configuration improvement. In the proposed device for the internal combustion engine the injecting and exhausting gas valve timing occurs in automatic mode in relation to the load applied to the engine shaft and the shaft speed. Several alternatives of the invention realization are proposed.. In the most preferred embodiment of the invention (fig.3b and fig.5) the camshafts cams 30 and 31 operates through the rocker arms 33, mounted on the axle 32, at that each cylinder has four distributing valves two admission 10 and two emission 11 valves disposed in mutually antithetic position, as well as two camshafts 21 and 26, which are similar by construction with those installed in the two camshafts engines each cylinder has one admission and one emission camshaft. In such a rocker arms 33 and cams 30 and 31 interaction with admission 10 and emission 11 valves there are one intake and one discharge manifolds on the cylinder flow head opposite sides.

Description

Technical Field

The invention refers to the mechanical engineering industry, more properly - to the internal combustion engine gas-distributing device configuration improvement. In the proposed mechanical arrangement for the internal combustion engine the injecting and exhausting gas valve timing occurs in automatic mode in relation to the load applied to the engine shaft and the shaft speed.

Background Art

The gas valve timing mechanism function is in timed injection of the fuel-air mixture or air in the engine cylinders and the flue gas extraction from them. The mechanism configuration and parameters varies depending on the number of cylinders, their volume or the mode of engine use. The vehicle engines are generally equipped with the valve mechanism, which assure complete gas exchange at a high engine speed, when the engine is reaching the maximal power.
The injection and the exhaustion processes are the result of the consistent valves, driving mechanism and camshaft operation. The gas valve timing mechanism efficiency is evaluated in case of the multi cylinder engine by the coefficient of admission and the uniformity of each cylinder admission. To obtain the better cylinder admission and flue gas emission, both the admission and the emission valves should be opened and closed before or after the piston changes its stroke in the dead centers. The valves opening and closing angle is assigned depending on the crankshaft rotation angle.
The maximal values of the piston stroke and the orifice area, as well as valve timing do not specify in complete mode the valves performance and the valve timing mechanism operation. Such a parameter as "time cross-section", which specify as orifice area, as well as duration of the flow passage can be used for more complete evaluation purpose.
Generally known internal combustion engine valve timing mechanisms are presented on the fig.1, where: a, b, c and d - are the mechanisms with overhead camshaft and valves; e - mechanisms with overhead valves and underneath camshaft; f - mechanisms with lower valves. The fig.1 positions are as follows: 1 - camshaft with cams; 2 - valve; 3 - spring; 4, 5, 6 - cross member; 7 - pushrod; 8 - cylindrical pusher.
The valve timing mechanism is known (fig. 2a), where for each cylinder there are four gas distribution valves, at that there is a couple of camshafts in the flow head. One of the two is intended for simultaneous closing and opening for the defined time of the two admission ports 9 by means of two valves 10 situated on the same side of the combustion chamber 14. Using the generally known devise, placed with its driven gear at the camshaft leading end, fast simultaneous closing and opening of the admission valves 10 is assured with the engine speed increase.

Technical Problem to be Solved

It is an object of this invention

to reduce the idle speed limit, within that the engine operates steadily without vibrations;
to prevent the engine overheating, typical for the combustion engines at low speed from 0 to 1200 rpm;
to get the engine peak output not only at the high speed, but assure corresponding peak output for each valve timing condition;
to obtain better air and fuel mixing, thus assuring more complete fuel-air mixture combustion, fuel saving, as well as abate the air pollution;
to obtain different cylinder coefficient of admission in correspondence to the engine speed and the same fuel-air mixture final compression pressure as can be obtained with automatic degree of compression change.

Disclosure of the Invention

The set target is being achieved by substitution of the generally known valve timing mechanism with other one, which automatically modifies the admission and emission valves timing in function of the load applied to the engine and its speed, at that:

admission 9 and emission 12 ducts, as well as admission 10 and emission 11 1 valves all are situated in the engine flow head;
the power drive from the crankshaft to the gear 23 is made by the mechanism shaft 15, gear 22 and slide bushing 28, with built-in crosspiece 18, but the gears 19 and 25 teeth have opposite spiral direction;
the gear 19 drive the gear 20 and the camshaft 21, but the gear 25 drive the gear 27 and the camshaft 26;
the gears 19 and 20 have opposite with the gears 25 and 27 teeth spiral direction.

The essence of the invention is described in the following drawings:

the fig. 2b shows the admission 9 / 10 and emission 12 / 11 ducts / valves arrangement for one cylinder and the gas flows directions according to the invention, to assure the automatic valve timing adjustment;
the fig.3a and 3b show rocker arms 33 arrangement on the axles 32 and 34, as well as the admission 30 and emission 31 cams arrangement on the camshaft and their interaction with the admission 10 and emission 11 valves;
the fig.4 and fig.5 show the proposed device cinematic diagrams for two possible versions of the device realization;
the fig.6a, b, c, d show the proposed device admission and emission phase plain state changes during the engine operation in relation to the engine load and speed: a - idle run, b - low speed, c - high speed, d - extremely high speed.

The following notations are used on the mentioned figures: 9 - admission duct; 10 - emission duct; 11 - admission valve; 12 - emission valve; 13 - fuel or electric spark infeed opening; 14 - combustion chamber; 15 - governor driven shaft; 16 - arresting fin; 17 - governor weight; 18 - crosspiece; 19 -- the gear with one teeth spiral direction built-in in the crosspiece; 20 - the gear coupling with the gear 19; 21 - left-side camshaft; 22 - governor driven shaft gear; 23 - the crankshaft driven gear; 24 - spring; 25 - the gear with teeth spiral direction opposite to the gear 19, built-in in the crosspiece; 26 - right-side camshaft; 27 - the gear coupling with the gear 25; 28 - the slide bushing with internal gear teeth; 29 - the built-in in the crosspiece gear with two teeth spiral directions, which in the version of the device realization shown in the fig.5 substitutes two gears 19 and 25 with opposite teeth spiral directions; 30 - the camshaft cam for the admission valve opening and closing; 31 - the camshaft cam for the emission valve opening and closing; 32 and 34 - axles; 33 - rocker arms fixed on the axle.
In the proposed valve timing mechanism governor (fig.4 and fig.5) gear 23 is driven by the crankshaft. The gear 20 and the camshaft 21, as well as the gear 27 and the camshaft 26 rotate in the opposite direction to the governor shaft 15. The gear 23 through the shaft 15 drives the gear 22, which is all-the time coupled with gear type slide bushing 28. The gears 19 and 25 are placed at the definite distance one from another and together with the crosspiece 18 can move along the gear 22 in axial direction depending on the weight .17 position. As at the engine low speed the weight 17 centrifugal force is relatively low, the valve timing corresponds to the state, shown in the fig. 6a.
With the engine speed increase, the weight 17 centrifugal force also increases and overcoming the spring 24 resistance shifts the gears 19 and 25, which in their turn pivot the gears 20 and 27, and camshafts 21 and 26 each in its direction owing to the opposite teeth spiral. This occurs because of the slide bushing 28 with internal teeth slip along the gear 22, thus, additionally pivoting the gear 20 and the camshaft 21 in one direction, and the gear 27, driven by the gear 25, in the opposite. In this way, thanks to the gears 19, 20, 25 and 27 interaction, the cams of the camshafts 21 and 26 turn in the opposite directions, thus causing more wide admission and emission valve timing. The valve timing, in this case, corresponds to the state, shown in the fig. 6b. The valve timing state at higher speeds is illustrated in the fig. 6c and fig. 6d.
The speed of the overloaded engine decreases, causing the weight 17 centrifugal force decreasing. So, the spring 24 through the gears 19 and 25 get the camshafts 21 and 26 back in the initial position, causing gradual valve timing transfer from the state as in the fig. 6d to the lower 6c- state and further to the still lower 6b- and 6a- states. The governor returns the gas timing in the initial (stopping down) position at the engine stop.
It is obvious for the person skilled in the art that gears 19 and 25 can move along the gear 22 in axial direction not only under pressure of the weight 17 and spring 24. The invention may be also carried out by moving gears 19 and 25 in axial direction using hydraulic, electronic or other mechanical drive.
Depending on the proposed valve timing device application, for example in the street or in the racing car, the gear 23 drive and driven ratio should be chosen correspondingly i=1:1 and 1:2.
Gradual transfer from the state like in the fig. 6a to the state 6b is more proper for the engine intended for city use, but for the sport cars the transfer from the 6b to the 6c state and further to the 6d state is more advisable. Moreover, in the case of extreme norms of the operating engines take place transfer to the state 6d and still higher states. The effective use of the obtained advantage, as well as the fuel saving can be achieved by the proper choose of the change gear, with more favorable gears ratios, and the tire size.

Preferred Embodiments

In the first embodiment of the invention (see fig. 4 and claims 1 to 4) the valve timing governor configuration (fig. 4) cinematic diagram is built like four helical gears 19, 20, 25 and 27 all-time coupling, where the gear couples 19 and 20, and 25 and 27 have opposite teeth spiral directions. The weight 17 centrifugal force, compressing the governor spring 24 and causing the slide bushing 28 slip over the gear 22, induce the gears 19 and 25 axial displacement with corresponding pivoting of the gears 20 and 27, and relative camshafts 21 and 26, each in opposite directions, inducing in such a way more wide admission and emission valve timing.
In the second embodiment of the invention (see fig. 5 and claims 5 to 8), the gears 19 and 25 (as indicated on fig. 4) are substituted with one gear 29, where its part 19' has teeth spiral direction as the gear 19, but the part 25' has teeth spiral direction as the gear 25, besides, the part 19' and gear 20 teeth spiral direction is opposite to the part 25' and gear 27 teeth spiral direction.
In the both above mentioned embodiments of the invention the admission 11 and emission 12 valves of the engine combustion chamber are disposed as in the fig. 2b. The two camshafts 21 and 26 similar by design to those used on the engine of two camshaft types, that is one for the admission valves and the other for the emission valves per cylinder. Such type of the valves arrangement (fig. 2b) at the inlet creates the turbulent flow, favoring the fuel-air mixing and its combustion process. At the same time at the emission valve opening occurs the better condition for the exhaust gas exit.
In the third embodiment of the invention (see fig. 3a) the valve timing mechanism used to drive the gas-distributing device (fig. 4 or fig. 5). There are admission 30 and emission 31 cams on each of the camshafts 21 and 26, which through the axle 32 and the rocker arm 33 operate the admission 10 and emission 1.1 valves. The camshafts 21 and 26 are pivoted in the opposite directions when the engine reaches the certain speed. This pivoting results in the admission cam 30 on the camshaft 21 through the rocker arm 33, fixed on the axle 32 acts on one of the admission valves 10. The second admission valve 10 is acted upon through the rocker arm 33 by the admission cam 30, fixed on the second camshaft 26, which, driven by the governor (fig. 4 or fig.5), is pivoted in the direction opposite to the camshaft 21. In this way the cams 30 displacement in the opposite directions is realized, thus giving wider valve timing on admission. The camshaft 26 emission cam 31 through the rocker arm 33 acts on one of the emission valves 11, at that the other emission valve 11 is acted upon through the rocker arm 33, fixed on the axle 32, by the cam 31 fixed on the camshaft 21. The gearbox (fig. 4 or fig. 5) turns the camshafts 21 and 26 in the opposite directions. In this way the cams 31 displacement in the opposite directions is realized, thus giving wider valve timing on emission.
In the fourth embodiment of the invention (see fig. 3b) the valve timing mechanism also used to drive the gas-distributing device (fig. 4 or fig. 5). There are admission 30 and emission 31 cams on each of the camshafts 21 and 26, which through the axle 34 and the rocker arm 33 operate the admission 10 and emission 11 valves. The camshafts 21 and 26 are pivoted in the opposite directions when the engine reaches the certain speed. This pivoting results in the admission cam 30 on the camshaft 21 acts on one of the admission valves 10. The second admission valve 10 is acted upon through the rocker arm 33 by the admission cam 30, fixed on the second camshaft 26, which, driven by the governor (fig. 4 or fig.5), is pivoted in the direction opposite to the camshaft 21. In this way the cams 30 displacement in the opposite directions is realized, thus giving wider valve timing on admission. The camshaft 26 emission cam 31 acts on one of the emission valves 11, at that the other emission valve 11 is acted upon through the rocker arm 33, fixed on the axle 34, by the cam 31 fixed on the camshaft 21. The gearbox (fig. 4 or fig. 5) turns the camshafts 21 and 26 in the opposite directions. In this way the cams 31 displacement in the opposite directions is realized, thus giving wider valve timing on emission.
The advantageous effects of the proposed gas-distributing device are as following:

the device can be made on the base of the existing gas distributing mechanisms elements;
it is possible to reduce the engine idle run speed up to 400 rpm and even lower, at that the engine works steadily without vibrations;
in the city traffic regime the fuel consumption, as well as air pollution are reduced;
more complete gas exchange occurs at various engine speeds, resulting in the engine power increase and enhancing its operation dynamics.

Bibliography:

1. Tractor and motor-car engine construction. The theory and analysis (Ed. by Kazhoka and G. Melgalvis), Riga, Zvaigzne, 1980.
2. Internal combustion engines. Design and duty of piston and compound engines (Ed. by A.S. Orlin, M. G. Kruglov), Moscow, Mashinostrojenie Publishers, 1990.
3. M. A. Masino, V. N. Alexeev, G. V. Motovilin. Automotive materials. Reference book for mechanical engineer. Moscow, Transport Publishers, 1979.r

Claims

Gas-distributing device, which automatically changes the admission and emission valves timing in relation to the load, applied to the engine shaft and the shaft speed, characterized in that it is configured as four all-time coupled helical gears (19, 20, 25 and 27), where the gears (19) and (20) teeth spiral direction is opposite to the gears (2S. and 27) teeth spiral direction, at that the weight (17) centrifugal force, compressing the governor spring (24) and causing the slide bushing (28) slip over the gear (22), induce the gears (19 and 25) axial displacement with corresponding pivoting of the gears (20 and 27), and relative camshafts (21 and 26), each in opposite directions, thus inducing more wide admission and emission valve timing.
Gas-distributing device, as claimed in Claim 1, characterized in that the gear (19) commands the gear (20) and the camshaft (21), but the gear (25) commands the gear (27) and camshaft (26).
Gas-distributing device, as claimed in Claim 1 or 2, characterized in that the power transmission from the crankshaft to the gear (23) is realized by the governor axle (15), gear (22) and slide bushing (28) with built-in crosspiece (18) and gears (19 and 25) with opposite teeth spiral directions.
Gas-distributing device, according to any of the preceding Claims, characterized in that the admission duct (9) and emission duct (12), as well as admission valve (10) and emission valve (11) all are disposed in the engine head, at that each cylinder has four gas distributing valves, disposed cross wisely relative to each other: two admission valves (10) and two emission valves (11) and two camshafts (21 and 26); as a result the camshafts cams interfere directly with admission valves (10) and emission valves (11), in such an camshafts cams and camshafts interaction there are one intake and one discharge manifolds attached to the corresponding admission duct (9) and emission duct (12) on the each side of the cylinder flow head.
Gas-distributing device, which automatically changes the admission and emission valves timing in relation to the load, applied to the engine shaft and the shaft speed, characterized in that it is configured as three all-time coupled helical gears (20, 27 and 29), where part (19') of the gear (29) and gear (20) teeth spiral direction is opposite to part (25') of the gear (29) and gear (27) teeth spiral direction, at that the weight (17) centrifugal force, compressing the governor spring (24) and causing the slide bushing (28) slip over the gear (22), induce the gear part (19' and 25') axial displacement with corresponding pivoting of the gears (20 and 27), and relative camshafts (21 and 26), each in opposite directions, thus inducing more wide admission and emission valve timing.
Gas-distributing device, as claimed in Claim 5, characterized in that the gear part (19') commands the gear (20) and the camshaft (21), but the gear part (25') commands the gear (27) and camshaft (26).
Gas-distributing device, as claimed in Claim 5 or 6, characterized in that the power transmission from the crankshaft to the gear (23) is realized by the governor axle (15), gear (22) and slide bushing (28) with built-in crosspiece (18) and gear parts (19' and 25') with opposite teeth spiral directions.
Gas-distributing device, according to Claims 5 to 7, characterized in that the admission duct (9) and emission duct (12) and admission valve (10) and emission valve (11) all are disposed in the engine head, at that each cylinder has four gas distributing valves, disposed cross wisely relative to each other: two admission valves (10) and two emission valves (11) and two camshaft (21 and 26); as a result the camshafts cams interfere directly with admission valves (10) and emission valves (11), in such an camshafts cams and camshafts interaction there are one intake and one discharge manifolds attached to the corresponding admission duct (9) and emission duct (12) on the each side of the cylinder flow head.