US1646789A - Internal-combustion engine - Google Patents

Description

Oct. 25,1927. 1,646,789 M. GATT] INTERNAL comaus'now ENGINE Filed July s. 1922 4 Sheets-Sheet 1 see; as 84 -4 ea I e l 80 v III/06.2mm o o H.

Oct. 25, 1927.

M. GATT! INTERNAL COMBUSTION ENGINE Filed July 5. 1922 4 Sheets-Sheet 2 Oct. 25, 1927.

M. GATT] INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 3 Filed July 5. 1922 I WWW w,

Oct. 25, 1927. M. GATTI INTERNAL COMBUSTION ENGINE Filed July 5; 1922 4 Sheets-Sheet 4 Patented Oct. 25 1927.

UNITED STATES PATENT OFFICE- MARIO GATTI, 0F MILAN, ITALY.

INTERNAL-COMBUSTION ENGINE.

The present invention has for its object a two-stroke internal combustion engine, which is designed to work by means of liquid fuel of any class whatever.

The motive system in question is characterized by the fact that the working cylinder so called is connected in a suitable way with a supplementary cylinder, the object of which is to furnish the scavengin air and to produce, at the same time, 'hig ly compressed air, which, by passing through an 1njector, has the eli'ect of atomizing the liqu1d fuel which has been injected into it and which serves to start the engine working. This mixture, as a result of the high compression of ,the air in the supplementary cylinder, and in consequence of a certain pressure etfected,'at the same time, in the main cylinder, will be ignited spontaneously upon passing into the interior of this latter cylinder, where the process of combustion will be completed, either with a constant volume of fuel or at a constant pressure, according as the regulating organs of the engine are adjusted to produce, at a given moment, a rapid or slow opening of the injector.

Other special characteristics of the invention are formed by various devices and arrangements which are'intended to give and to ensure to the engine regular and economic working.

Among the accessories provision has been made for a particularly important blowing apparatus, which will provide the air necessary for the compressed air supplementary cylinder.

- The idea of the invention will be readily understood by referring to the annexed drawings which show, by wa of example, some practical form of executlon of this invention.

According to these drawings:

Figs. 1, 2 and 3 are respectively a view in median-vertical section; a section drawn at right angles to the first; and a plan of the motive system, provided with cooling water circulation.

Figs. 4 and 5 give respectively a side view, partly in section, and a median section drawn at right angles to the first, of a similar engine with a cylinder provided with cooling vanes for same.

Fig. 6 shows in median section the detail of the upper part of the engine, in accordance with Figs. 1 and 3, in which the injector is seen fitted.

Figs. 7 and 8 show respectively a view in longitudinal section, and a, cross section alqr g the line .1:a: of the gtormer, of an engine,"in accordance witlif fjltlie invention, having four cylinders.

Fig. 9 gives the detail of an arrangement applicable to the said engines for purposes of starting.

Figs. 10 and 11 show respectively a longitudinal section and a plan of the piston with which the blowing apparatus, which completes the motive system, is provided, and which serves, as has already been said, to furnish air to the supplementary cylinder for purposes of compression.

Fig. 12 shows an alternative arrangement of the blowing apparatus referred to; and

Fig. 13, finally, deals with a way whereby the rod of the working cylinder properly so called, and that of the supplementary cylinder, may be connected.

In the different figures the same or similar parts are indicated by the same numerals.

As regards Figs. 1, 3 and 7, 8, the arrangement comprises, for each working cylinder 1, the centre of which is placed in a plane passing through the centre of the driving shaft, an auxiliary cylinder 3 of smaller dlameter, the centre of which is moved forwards relatively to the centre of driving shaft 2 in the direction of rotation of this latter. The two rods 4 and 5 of the two pistons which run in the cylinders 1 and 3 are both connected to the same crank pin 8; or, in order to simplify the construction or design, the rod 5 of the smaller iston 7 may be connected up with the second rod 4 at any part whatever of this latter; as, for example, may be seen in Fig. 13, on a lug 9 arranged on the rod 4.. In the couple of cylinders 1 and 3, the two pistons 6 and 7 are both compressors in the compression phase of their work, and motors in the combustion and expansion phases.

The larger diameter cylinder 1 is provided beneath with openings 10 which open into the discharge tube 11, and above with openings 12 which establish connection with the smaller diameter cylinder 3, which, in turn, is provided beneath with openings 13 which communicate with the air inlet pipe. The smaller cylinder communicates above, by means of the conduit 15, with the injector connected, by means of a suitable nozzle,

with the retention valve 19 placed above the cylinder 1 at the side of the injector 16.

The larger diameter cylinders 1, and the smaller diameter cylinders 8, are fitted to a single body, provided with a water cooling jacket (Figs. 1, 3 and 7, 8) or with radi- .-,-ation vanes 21 (Figs-'4:- and 5).

The air is driven into the cylinder 3 through the conduit 14 arid the openings 13, by a blowing apparatus which is formed of a cylindrical body 22 cast in one piece with the housing of the engine 23, and closed by a cover 24, the latter being provided with an opening 25 for admission of air and which is regulated by means of the wing valve 26 (Fig. 4). The piston 27 slides along in the interior of the body 22 of the blowing apparatus, and this piston carries the suction valve 28. The movement of the piston 27 is controlled by the worm 29, which is keyed on to the driving shaft 2, and provided with an inclined groove 30 (Figs. 1 and 5) in which the lower half of a flange 30 slides, whilst the other half of it 'is enclosed in a plug fitted on the piston rod 27. The rod 31,fixed on the bottom of the body 22 and in the cover 24, traverses the radius of the piston rod, thus preventing the latter from turning, whilst the rotation of the worm. 29 imposes an alternating movement on he piston 27' by the gliding action of the flange 30 in the groove 30 The working of the suction valve 28 will be clearly understood by an inspection of Fig. 10, in accordance with which the said valve, which is formed of a fine ring 32 of steel, fitted on the wall of the piston 27 and provided with several pins 33, which pass through the said wall and carry light springs 34. These springs force the ring valve to grip against the wall of the piston 27 and to bind the ports 25 intended for the passage of the air. I

Thismotive system is completed by a flywheel 36, an ordinary centrifugal regulator, a pump for the circulation of the water, if the engine is cooled by circulation of water, and another lubricating pump.

The working of the engine is as follows: When the crank has been turnedv about 60 and before reaching the outer dead centre, the larger piston 6 begins to open the exhaust openings 10, thus setting up a reduction of pressure in the exhaust gases, which continues up to 95% of the outer stroke. At this point the pressure of the gases in the cylinder 1 has considerably weakened, so much so as to permit the admission of the scavenging air, which passes from the blower through the pipe 14 and the openings 13 into the small cylinder 3, whence it enters the larger cylinder 1 through the openings 12 and the conduit 15. At this stage, the needle of the spraying nozzle 16 being raised, communication between 15 and 1 is free.- The residuary gases of combustion will thus be expelled from the cylinder 1 through the opening 10 and the pipe 11. The crank, on continuing its rotation, and when it has reached about 60, above the outer dead centre, compels the two pistons 6 and 7 to close the openings 10 and 12, at the same instant. At this juncture the compression phase, which is common to the two cylinders 1 and 3, begins, and at the same time the nozzle of the injector 16 is lowered, with the result that communication between the cylinders 1 and 3, through the conduit 15, is interrupted, the only avenue of communication remaining open being that'through the opening 12. The cylinders 1 and 3 will remain in reciprocal communication up to the moment in which the smaller piston 7 reaches the height of the openings 12, after which, the said openings being closed by 7, the two cylinders will be no longer in reciprocal communication one with the other, and the compression will continue separately in them for the remainder of the stroke of the pistons 6 and 7 right up to the dead centre. Meanwhile the fuel pump 18 will have delivered the required quantity of fuel to the lower section of the injector 16. Owing to the arrangement applied. the piston 7 of the small cylinder 3 will be at the upper dead centre; that is to say in the position of greatest compression, when the large piston 6 has passed the dead centre by some degrees; and as the smaller cylinder 3 has a very small compression chamber, much smaller than that of the large cylinder 1, the quantity of air enclosed by the small piston 7-beyond the openings 12 will attain a compression the extent of which is two or three times greater than that which has been produced in the larger cylinder. When the piston 7 has completed its compression stroke, introducing into the cylinder 3 the quantity of highly compressed air of which mention has been made above, the cam 17' will raise the nozzle of injector 16, whereupon the air, which has been compressed to the fullest possible extent in the small cylinder 3, will rush through the conduit 15 into the injector 16, passing from the latter into the large cylinder 1 and carrying with ,it the thus highly atomized fuel, which has I been delivered into the injector 16 by the pump lS. This :t'uel mixture, upon entering the cylinder 1, will ignite immediately and completely, thanks to the high temperature existing in the cylinder 1, owing to the compression of the air, and the temperature of the super-pressure air in the cylinder 3, forming part of the mixture itself.

When opening the injector 16 quickly, the injection is effected instantaneously, whic gives rise to combustion at a constantvolumc. If, on the contrary, it is desired to obtain combustion at a pressure nearly constant, it will be necessary suitably to regulate the manner of lifting the injector nozzle.

The type of the engine which has just been described and which is shown in the drawings, otters considerable advantages over either single or two-stroke engines.

In fact, comparing this engine with the Diesel motors, it is much superior by reason of the fact that it utilizes, by injection, heated air, which faciltates combustion; that it dispenses with the special compressor for the air to be injected; and. that it calls for a smaller amount of energy for the production of the compressed air, as no quantity of heat is dissipated.

As regards two-stroke engines, this new type of engineptfers the following advantages: complete introduction of the fuel mixture and even superfeeding, should the regard to the fuel.

needarise, in accordance with the capacity of the blower; more perfect scavenging, as this is procured in the direction of the exhaust current itself and during a longer interval; more time, available for the depression of the exhaust gases; closing. of the inlet and outlet openings at the same moment and, if this should be necessary, a retarded closure of the inlet as compared with theoutlet, in order to realize super-feeding. All' this remains in the fraction of stroke of the ordinary two-stroke engines.

The fuel injector 16, used in the engine which forms the object of this invention, is formed (Fig. 6) of a rod 37 which closes the mouth of the conduit towards the large cylinder 1. In this rod a small rod 38 slides and on the latter thespring 39 which is placed inside the rod 37 acts. -This arrangement of the two rods 37 and 38 allows of the secure closure on their seats, of the rod 37 in regard to the air,and of the rod 38 in livered by the pump 18, issues from the retention valve 19 and is deposited in the chamber 40. On the opening of the in jector, the rod 37, as soon as it has been lifted from its seat by several tenths of a millimetre, jection, the head 41 of the small rod 38 so as to lift it. At this moment the air, which has first been introduced into the chamber. by 15, will inject the fuel into the compression chamber of the cylinder 1 as a result of the lifting of 37.

In Fig. 12 there is shown a modified arrangement of the blower which, in this case, is provided with the double effect cylinder 22 and is driven from-the piston 27' by means of cranks on a small separate shaft 42 which is driven by gearing.

" 1, it does not The fuel, which is dewill touch, by means of a pro,

In Fig. 7, the blowing set is shown mounted on the extension of the driving shaft 2 and is. composed of two apparatus, each of double effect, with the corresponding pistons-driven by the worm, ashas been described above.

Fig. 8 shows, on one side, the arrangement of the cam shaft 43 which drives the injectors 16 and the fuel pumps 18, whilst, on the opposite side, the four blown air pipes coming from the set are seen.

In the types of engines, such as those to which this invention applies, starting by hand, if it can be done in machines of limited power, is difficult to eflect when it is a matter of motors of somewhat considerable dimensions, owing to the high degree of compression which is 1 obtained in these engines. In such cases recourse may be had to one of the ordinary compressed air systems,'hitherto used in practice, or to the special arrangement which we are about to describe and which is shown in Fig. 9. The said arrangement comprises a chamber 44, in communication with the compression chamber of the large cylinder 1, by means of the pipe 45; a ball valve 46, carried by the finely-screwed rod 47, and driven by the crank 48, allows of establishing or breakingcommunication of the chamber 44 with the cylinder 1. The capacity of the chamber 44 is suchthat, with that of the cylinder allow of exceeding the degree of compression of 4 and 5; In the said chamber,44 there is fitted a retention valve 48, bra'noh connected with a three-way cock lace'd on the pressure pipe of the fuel pump. 11 49 there is arranged a lighter which is formed of an electric candle or of a sprin arrangement, the indented barrel .50 of whic rubs against a piece of cerium iron 51 and produces a spar 52, is driven by jector working.

As regards starting, lows:

with the assistance of the lever 48 the valve 46 is opened; the three-way fuel cock is-turned in the direction towards the retention valve 48 of the chamber 44, instead of directing it towards that of the injector.

The electric light or the lighting arrangement of cerium iron is attached; and for the the rod which starts the inthe method is as folcrank 53 the engine is turned. In this manthe engine starts working at a low pressure. At the moment the engine has reached the correct working speed, the three-way cock is turned and the fuel is delivered to the injector, instead of its being sent to the cham- The spring bolt, fitted at her 44. Then the lever 48 is turned and the valve 46 is closed, so as to cut E the chamber 44, and it is at this juncture that the engine will begin to work at high compression and the lighting will be cut off either by hand or automatically. The chamber 44 is provided with a pipe 54 which runs along the cylinder 1 up to the height of the exhaust openings, this being intended to facilitate the'cleaning of the said chamber 44. It is understood that the detailsv of construction ture. arranged in communication with the.

working cylinder, a scavenging air supply communicating with the medial portion of the auxiliary cylinder, a piston for the auxiliarycylinder including a head and a rod, the rod of the piston of the auxiliary cylinder being connected to the rod of the piston in the working cylinder in such manner that the head of the piston in the auxiliary cylinder acts at lower dead center as a valve to control the passage of scavenging air from the scavenging air supply to the working cylinder, substantially as and" for the pur poses set forth.

2.A" two-stroke internal combustion engine as claimed in claim 1, wherein the connections of the rod of the piston of the auxiliary cylinder with the rod of the piston of the working cylinder is arranged at a slight angle, so that the piston of the auxiliary cylinder will be vat upper dead center when I the piston of "the Working cylinder has passed the dead center.

3. A two-stroke internal combustion engine as claimed in clai'ml, wherein the point of c ommunicationbetween the two cylinders is arranged at'the top ofthe working cylin der but short of the top of the auxiliary cylinder to permit of supercompression of air in the upper part of the auxiliarycylinder, means for establishing communication between the extreme upper ends of both of said cylinders, an injector for furnishing liquid fuel positioned on top of the working cylinder, so that the supercompressed air from the auxiliary cylinder will pass therethrough as it enters the working cylinder-so asto be thoroughly mixed with the fuel.

4. A two-stroke internal combustion en-- ,gine as claimed in claim 1, wherein the point of communication between the twocylinders is arranged at the top of the working cylinder butshort of the top of the auxiliary cylinder to permit of super-compression of air in the upper part of the auxiliary cylinder, means for establishing communication between the extreme upper ends of both of said cylinders, an injector for furnishing liquid fuel positioned on top of the working cyl'nder,, so that. the supercompressed air I from the auxiliary cylinder will pass therethrough it' enters the working cylinder so as to be thoroughly mixed with the fuel, means for operating the injector including a cam rotatable with the main shaft of the engine, and a system of levers coacting with the cam for ensuring of the passage of compressed air from the auxiliary cylinder through the injector and thence. into the main cylinder in timed relation with the operation of the mainjc ylinder.

MARIO GATTI.

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