US3892206A

US3892206A - Combustion device for heat motors

Info

Publication number: US3892206A
Application number: US343150A
Authority: US
Inventors: Akira Kobayashi
Original assignee: Toyota Central R&D Labs Inc
Current assignee: Toyota Central R&D Labs Inc
Priority date: 1972-03-23
Filing date: 1973-03-20
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01
Also published as: JPS4896905A; JPS5749741B2

Abstract

A combustion device for use with motors for igniting and burning fuel-air mixture in which a cylindrical member (28) is airtightly fitted into a hole formed through the cylinder wall of the combustion chamber in such a manner that a plug chamber (35) with a bottom of the cylindrical member may be disposed within the combustion chamber, and an air discharge port (49), the fuel emerging surface of a fuel diffusion member (55) fitted into a fuel supply passage and electric spark ignition means are positioned within the plug chamber, whereby in starting the motor the fuel-air mixture in the combustion chamber is ignited by the combustion flame of the fuel-air mixture in the plug chamber (35) ignited by the ignition means and after the motor has been started the fuel-air mixture is ignited by the naked flame burning at the fuel emerging surface of the fuel diffusion member made of porous and refractory material.

Description

[ 1 July 1,1975

[ COMBUSTION DEVICE FOR HEAT MOTORS [75] Inventor:

[73] Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho, Nagoya, Japan [22] Filed: Mar. 20, 1973 [21] Appl. No.: 343,150

Akira Kobayashi, Nagoya, Japan [30] Foreign Application Priority Data Mar. 23, 1972 Japan 4529493 [52] U.S. Cl. 123/8119; 60/3982 P; 123/831; 123/30 B; 431/266 [51] Int. Cl F02b 53/12 [58] Field of Search 60/3943, 39.17, 39.82 P, 60/3982 R, 258; 431/261, 262, 263, 264,

[56] References Cited UNITED STATES PATENTS 799,856 9/1905 Lemale 60/3982 P 1,988,456 111935 Lysholm..... 60/3917 UX 2,214,568 9/1940 Thomas 431/264 2,710,652 6/1955 Ambrose..... 431/262 X 2,885.859 5/1959 Barberis 431/263 X 2,918,118 12/1959 Schirmer 431/263 2,967,224 1/1961 Irwin 431/263 X 3,056,157 10/1962 Close 60/3963 3,071,182 1/1963 Delano 431/352 X 3,073,121 l/l963 Baker et a1. 60/3982 P 3.073.122 1/1963 Ledwith 60/3982 R 3.263,?29 8/1966 Fetter et a1. .1 60/3982 R X 3,782,110 1/1974 Kobayushi 60/3943 FOREIGN PATENTS OR APPLICATIONS 468,390 7/1937 United Kingdom 60/3943 Primary ExaminerWilliam L. Freeh Assistant ExaminerMichae1 Koczo, Jr. Attorney, Agent, or FirmCushman, Darby & Cushman (57] ABSTRACT A combustion device for use with motors for igniting and burning fuel-air mixture in which a cylindrical member (28) is air-tightly fitted into a hole formed through the cylinder wall of the combustion chamber in such a manner that a plug chamber (35) with a bottom of the cylindrical member may be disposed within the combustion chamber, and an air discharge port (49), the fuel emerging surface of a fuel diffusion member (55) fitted into a fuel supply passage and electric spark ignition means are positioned within the plug chamber, whereby in starting the motor the fuelair mixture in the combustion chamber is ignited by the combustion flame of the fuel-air mixture in the plug chamber (35) ignited by the ignition means and after the motor has been started the fuel-air mixture is ignited by the naked flame burning at the fuel emerging surface of the fuel diffusion member made of porous and refractory material.

3 Claims, 10 Drawing Figures WEMTEDJUU SHEET FIG. 7

Q m I 8 O7 5 35 3%53 5W 53 M.

FIG. 8

FIG. 6

COMBUSTION DEVICE FOR HEAT MOTORS BACKGROUND OF THE INVENTION The present invention relates to a combustion device for use with heat motors such as rotary engines or motors, gas turbines, steam engines and the like.

The pollution due to automobile exhaust gases is now a serious problem, and since the main sources of the air pollution are the ordinary reciprocating automobile engines, various alternatives are being studied and developed, including rotary engines, electric propulsion engines, gas turbines and a variety of steam or vapor engines because each of these alternative engines 01' motors offers certain emission advantages in comparison with the conventional piston engines. Some of the alternative engines have been already successfully used in practice.

The rotary engine or motor which is now used as an automotive power plant has some defects. First of all the resisting torque of an automobile varies over a wide range so that the combustion is temporarily so reduced that the newly charged fuel-air mixture cannot be ignited and burnt. In some cases the ignition timing is much delayed and in the worst case the misfiring occurs. These problems are common in other alternative engines or motors and must be solved in order to achieve the smooth control of the engine or motor output.

SUMMARY OF THE INVENTION The present invention was made in order to solve these and other related problems of the heat motors. When a combustion device in accordance with the present invention is used with a heat motor such as a rotary engine or motor, the continuous and complete combustion of fuel-air mixture can be assured regardless of the variation in fuel supply when the fuel supply is automatically controlled in response to the rotational speed of the motor or when the supply of fuel is increased as the need arises. Thus the above problems encountered in the conventional heat motors may be overcome and an excellent heat motor may be provided.

One object of the present invention is therefore to provide a combustion device for use with heat motors having excellent ignition characteristics in any operating conditions of the motor.

Another object of the present invention is to provide a combustion device for use with heat motors eliminating pollutants contained in exhaust gases.

Further object of the present invention is to provide a combustion device for use with heat motors having a simple and compact construction.

Briefly stated, a combustion device in accordance with the present invention is used with a heat motor of the type having a combustion chamber in which a fuel charge is mixed with air and ignited and burnt, and is characterized in that a cylindrical body member is airtightly fitted into a hole formed through the outer cylinder wall of the combustion chamber in such a manner that a plug chamber with a bottom which is defined at the lower end portion of the cylindrical member may be disposed within the combustion chamber; an air discharge port of an air supply passage formed through the cylindrical body member and in communication with an air supply source is opened into the plug chamber; a fuel discharge port of a fuel supply passage formed through the cylindrical body member and in communication with a fuel supply source is opened into the plug chamber adjacent to the air discharge port; a fuel permeating or diffusion member provided with a large number of fine passage holes and made of a porous and refractory material is fitted into the fuel supply passage adjacent to the fuel discharge port in such a manner that the fuel emerging surface thereof may face the plug chamber; and spark ignition means which is electrically connected to an electric power source is disposed adjacent to the air and fuel discharge ports so as to ignite the fuel-air mixture consisting of fuel discharged through the fuel discharge port and air discharged through the air discharge port, whereby when the motor is started the fuel-air mixture in the combustion chamber is ignited by the combustion flame of the fuel-air mixture in the plug chamber ignited by the electrical spark ignition means and after the motor has been started the fuel-air mixture in the combustion chamber is ignited by a naked flame of fuel burning at the fuel emerging end surface of the fuel permeating or diffusion member.

According to the present invention the high ionization tendency as well as the high ignition capability of the naked flame of fuel burning at the fuel emerging surface of the fuel permeating or diffusion member may ensure the positive and rapid ignition of the fuelair mixture in the combustion chamber regardless of the variation in motor speed. a

The combustion device in accordance with the present invention may ensure the smooth operation of a heat motor, improve the characteristics and efficiency thereof, ensure the complete combustion of fuel-air mixture in the combustion chamber and reduces the pollutants contained in exhaust gases.

When the combustion device in accordance with the present invention is used with an automotive engine or motor of the type in which the rotational speed may be varied in response to the variation in load, a device for attaining the synchronization with the rotational speed of a crankshaft used in a conventional ignition system of a piston engine may be eliminated. Thus the ignition system for automotive engines or motors may be made simple in construction and compact in size, and the problem of intereference due to the spark ignition in the conventional piston engine may be completely overcome.

The present invention will become more apparent from the following description of some preferred embodiments thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a vane type rotary motor to which is applied a first embodiment of a combustion device in accordance with the present invention;

FIG. 2 is a perspective view, partly in section, of the combustion device together with a circuit diagram of its ignition system;

FIGS. 3A and 3B are sectional views taken along the lines "I -III, and Ill -Ill of FIG. 2;

FIG. 4 is a fragmentary view, on much enlarged scale, of the rotary motor shown in FIG. I, two fuel supply systems and an acceleration control system associated with the combustion device being also shown;

FIGS. and 6 are longitudinal and cross sectional views of a second embodiment of a combustion device in accordance with the present invention;

FIGS. 7 and 8 are longitudinal and cross sectional views of a third embodiment of a combustion device in accordance with the present invention;

FIGS. 9 and are schematic views used for the explanation of the mode of operation of the combustion devices of the first and third embodiments.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment, FIGS. 1 4

The present invention will be described in detail hereinafter as being applied to a vane type rotary motor previously proposed by the invention of the present in vention, in which the steady and continuous fuel-air mixture supply and combustion are ensured so that the highly efficient conversion of the combustion energy into the work may be achieved. The construction of the vane type rotary motor will be described in brief with reference to FIG. 1. Within a cylinder 2 having an ellipsoidal inner wall 1 is disposed a cylindrical rotor 3 carried by a rotary shaft 5 which in turn is rotatably supported by a cylinder wall 4 of the cylinder 2. The rotor 3 is provided with an equiangularly spaced apart radial guide slots 7 extending radially inwardly from the cylindrical surface 6 thereof, and a vane 8 is slidably inserted into each of the radial guide slots 7, and has its inner end pivoted with a pivot pin 9 to a joint of an equilateral quadrangular linkage or rhombic link generally indicated by 14 and consisting of four links 10, ll, 12 and 13 equal in length. Each pair of opposing links 10 and 12, and 11 and 13 have their midpoints pivoted to a supporting link 15 which in turn is rotatably fitted over the rotary shaft 5. Rollers 16 which are rotatably carried by the pivot pins 9 are made in contact with a cam 17 having an elliptical cross sectional configuration.

Therefore when the rotary shaft 5 and hence the rotor 3 are rotated by a driving means (not shown), the rollers 16 ride over the elliptical cam 17 so that the linkage 14 changes its configuration between a square and a rhomb with the apexes of the vanes 8 describing an elliptical path.

The ellipsoidal inner wall 1 of the cylinder 2 is formed to conform with the elliptical path described by the apexes of the vanes 8, and the cylinder 2 is divided into four individual chambers 18 each of which is defined by the inner wall 1 of the cylinder, the outer wall 3' of the rotor 3 and the adjacent vanes 8. One end of an inlet passage 19, which is disposed in such a manner that its axis is normal to that of the cylinder 2 and the rotor 3, is communicated with a source of fluid such as air and the other end which terminates to an intake port 20 is opened at the inner wall 1 of the cylinder 2 so as to supply air into the chamber 18 in communication with the intake port 20.

A discharge passage 22 having a discharge port 2] opened at the inner wall 1 of the cylinder 2 is disposed in parallel with and adjacent to the supply passage 19 so that the exhaust gases produced when the fuel-air mixture is ignited and burnt may be discharged from the chamber 18 to the exterior.

In opposed relation with the air supply passage 19 is formed in the cylinder wall 4 a compressed air passage 24 for passing the air compressed in the compression quadrant within the chamber 18 into a combustion chamber 23 opened to the chamber 18 in the expansion quadrant. A fuel injection device 26 communicated with a second fuel tank F is disposed in opposed relation with the discharge passage 22 to inject the fuel into the combustion chamber 23.

In the vane type rotary motor V of the type described the continuous and smooth suction. compression, ignition-expansion and discharge quadrants are provided as the vanes 8 are revolved in one direction, and the rotary motor exhibits many excellent characteristics.

A fuel combustion device 27 in accordance with the present invention is disposed in the wall of the combustion chamber 23 of the vane type rotary motor V adjacent to the fuel injection device 26. The fuel combustion device 27 as well as its associated systems such as a first fuel supply system A, a second fuel supply system B, a compressed air supply system C and an electric ignition mechanism D for starting the motor will be described in detail hereinafter.

As best shown in FIGS. 2 and 3, the combustion device 27 in accordance with the present invention comprises a cylindrical main body 28 provided with externally threaded screws 29 for fitting the combustion device 27 air-tightly into an internally threaded hole 30 formed through the wall of the combustion chamber 23. To the lower end of the main body 28 is fitted a hollow cylinder 32 made of a refractory material such as lnconel and provided with a plurality of small apertures 31. Thus a plug chamber having a bottom is defined by the lower end 33 of the main body 28 and the inner wall 34 of the hollow cylinder 32, and is communicated with the combustion chamber 23 through the opened end of the hollow cylinder 32 as well as the small apertures 31 thereof.

A through bore 36 having an enlarged diameter portion at the top thereof as best shown in FIG. 2 is formed through the main body 28 coaxially thereof, and a refractory material 37 is air-tightly filled within the through bore 36 with gaskets 38. A center electrode electrically connected to a power source 39 is extended through the refractory material 37 coaxially of the main body 28 and has its lower end extended through the refractory material 37 and spaced apart by a predetermined distance from a ground electrode 41 extended from the inner wall 34 of the hollow cylinder 32 radially thereof as best shown in FIG. 3A so that a spark gap may be formed between the two

electrodes

40 and 41. The two

electrodes

40 and 41 are electrically connected through the ignition mechanism D to be described in more detail hereinafter to the power source 39 so that an ignition zone 42 may be formed therebetween. The refractory material 37 as well as the center electrode 40 may be further air-tightly enclosed within the main body by means of a cap 44 which is screwed to the externally threaded screws 43 formed along the side wall of the main body 28 in opposed relation with the enlarged diameter portion of the through bore 36.

An air supply passage 45 is formed through the main body 28 in parallel with but in spaced apart relation with the through bore 36 and the refractory material 37 filled therein. An inlet 46 of the air passage 45 is connected to a compressed air supply pipe 47 which in turn is communicated with a compressed air reservoir 48 to be described hereinafter and a compressed air discharge port 49 of the air supply passage 45 is opened at the bottom 33 of the main body 28 into the plug chamber 35 so as to supply the compressed air into the chamber 35.

A fuel passage 50 is also formed through the main body 28 in parallel with but spaced apart from the through bore 36 and in diametrically opposed relation with the air supply passage 45. An inlet port 51 of the fuel supply passage 50 is coupled to a fuel supply pipe 52 which in turn is communicated with the first fuel tank F,, and a fuel discharge port 53 is opened at the bottom 33 of the main body 28 so as to supply the fuel into the plug chamber 35.

Within a bore portion 54 of the fuel supply passage 50 is fitted a cylindrical dense but porous fuel permeating or diffusion member 55 made of a refractory material such as graphite fibers, the diameter of the fuel permeating or diffusion member 55 being substantially equal to the inner diameter of the bore 54. The lower end of the fuel permeating or diffusion member 55 is made to flush with the end surface of the main body 28 whereas the upper end is communicated with the fuel supply passage 50. A slot 56 is formed through the outer wall of the main body 28 in parallel and communication with the fuel supply passage 50 in such a manner that a support member 57 which is air-tightly fitted into the slot 56 has its inner surface 58 made into close contact with the fuel permeating or diffusion member 55. The outer surface 59 of the support member 57 is flushed with the outer surface of the main body 28 and fitted with the hollow cylinder 32. Thus the fuel permeating or diffusion member 55 may be securely held in the fuel supply passage 50 and is prevented from falling off therefrom. The quantity of fuel permeated or diffused through the fuel permeating or diffusion member 55 is dependent upon the number of graphite fibers of a fiber bundle which form a large number of fine passage holes and a pressure with which the supporting member 57 is pressed against the fuel permeating or diffusion member 55. Furthermore graphite fiber, glass fiber or the like are coarsely filled in the space in the fuel supply passage 50 between the fuel permeating or diffusion member 55 and the fuel inlet 51.

Next referring to FIG. 4 the first and second fuel feed systems A and B, the compressed air feed system C and the electric ignition mechanism D all of which are associated with the fuel combustion device 27 of the first embodiment will be described.

The first fuel supply system A comprises an automatic directional control valve 58 in communication with the fuel supply passage 50in the fuel combustion device 27 through the fuel feed pipe 52 and the fuel tank F in communication with the automatic directional control valve 58 through a fuel feed line 59. The compressed air produced in the vane type rotary motor V is introduced into the fuel tank F so as to act upon the surface of the fuel (gasoline) in the tank F,.

The automatic directional control valve 58 comprises a spool 61 slidably fitted into a cylinder 60, and the upper chamber above the spool 61 is communicated with the discharge port of an injection pump 72 in the second fuel supply system B whereas a spring S is loaded in the lower chamber below the spool 61. The force of the spring S may be adjusted by an adjusting screw or plug 62. A first passage 63 is diametrically formed through the spool 61 and has its one end communicated through a port in the cylinder wall to the first fuel tank F, and the other end communicated through a port in the cylinder wall with the fuel feed pipe 52. One end of a second passage 64 formed through the spool 61 is communicated with the first passage 63 whereas the other end is communicated with the discharge port of the fuel injection pump 72 through a nozzle 65.

The pressure of the fuel discharged by the fuel pump 72 acts upon the upper end of the spool 61 whereas the force of the spring S acts upon the lower end of the spool 61. Therefore when the force of the spring S is in excess of the discharge pressure, the second passage 64 is closed whereas the first passage 63 serves to intercommunicate between the first fuel tank F and the fuel supply passage 50 in the fuel combustion device 27 so that the fuel in the tank F may be supplied to the fuel permeating or diffusion member 55 in the fuel combustion device 27. However, when the force of the spring S is smaller than the discharge pressure the first passage 63 in the spool 61 is closed whereas the second passage 64 is opened so that the fuel tank F in the second fuel supply system B may be communicated with the fuel supply passage 50. As a result the fuel or kerosine in the second fuel tank F may be supplied to the fuel permeating or diffusion member 55 in the fuel combustion chamber 27.

The second fuel feed system B comprises component parts used for establishing the communication between the fuel injection device 26 and the fuel tank F That is, the second fuel supply system B comprises a fuel suction pump for lifting the fuel from the tank F a governor pump 71 and the fuel injection pump 72 all of which are hydraulically connected in series. The discharge port of the governor pump 71 is communicated with the suction port of the fuel injection pump 72, with the pressure adjusting chamber 73 in the fuel injection device 26 and with the suction port of the governor pump 71 through a governor orifice 74. The discharge port of the fuel injection pump 72 is communicated with a fuel pressure chamber 75 in the fuel injection device 26 which in turn is communicated with the combustion chamber 23 through a fuel passage 76 and a fuel injection nozzle 77.

The shoulder 79 of a return valve 78 disposed within the fuel injection device 26 is adapted to seat on an inner wall or valve seat 80 at which is opened a return pipe 81 which in turn is connected through a throat 82 to the suction port of the governor pump 71. A bore 83 formed within the return valve 78 is communicated through a passage 84' formed in the cylinder wall of the fuel injection device 26 with the combustion chamber 23 so that the pressure in the combustion chamber 23 may be fed back into the bore 83. The return valve 78 is operatively coupled through an acceleration spring 85 loaded between the valve 78 and an actuator 86 to an acceleration mechanism E which in turn is coupled to an acceleration pedal G through the actuator 86 and a servo valve 87 so that the fuel to be charged into the combustion chamber 23 may be controlled in response to the rotational speed of the vane type rotary motor V. That is, the return valve 78 is displaced axially under the force of the acceleration spring 85 loaded between the rear end 88 of the return valve 78 and the flange of the actuator 86 in response to the stroke of the acceleration pedal G. Thus the return valve 78 is held in balanced position when the injection pressure in the pressure chamber 75 is in equilibrium with the pressure in the combustion chamber 23 which is transmitted into the bore 83 within the return valve 78 and the discharge pressure of the governor pump 71 which is transmitted into the pressure adjusting chamber 73. As a result the fuel may be supplied in proportion to the rotational speed of the vane type rotary motor V, and the fuel supply may be also controlled independently of the rotational speed of the motor by the acceleration mechanism E operatively coupled to the return valve 78. Thus the torque may be adjusted.

Next referring back to FIG. 1, the compressed air supply system C will be described. in the cylinder wall 4 is formed an air reservoir 48 which is communicated with the compressed air suction passage 24 through a rotary valve 91 which functions as a stop valve and a pressure control valve 92 which serves to control the pressure of the air to be introduced into the compressed air reservoir 48. A compressed air discharge passage 25 has a cock 93 inserted therein in order to control the air flow into the combustion chamber 23. The air reservoir 48 is also communicated through the compressed air supply pipe 47 with the air supply passage 45 in the fuel combustion device 27 so that the compressed air may be supplied from the air reservoir 48 to the plug chamber in the combustion device 27.

Next referring back to FIGS. 2 and 4, the electric ignition mechanism D will be described which generally comprises a starting motor 94, the power source 39, a starting switch 95, an ignition coil 96 and a starting ig nition circuit 97. When the starting switch 95 is closed the current is supplied to the starting motor 94 so that the rotor 3 is rotated through a gear train (not shown). Simultaneously the current flowing through a primary d of the ignition coil 96 induces the low voltage current flowing through a secondary a" to the center electrode 40. When the rotational speed of the starting motor 94 which is drivingly coupled to the rotor 3 through the gear train (not shown) becomes in excess of a predetermined speed, the starting switch 95 is automatically opened so that the current flow to the center electrode may be interrupted.

Next the mode of operation will be described. The plug chamber 35 in the combustion device 27 in communication with the combustion chamber 23 has the discharge port 49 of the air supply passage in communication with the air reservoir 48 and the fuel discharge port 53 of the fuel supply passage in communication with the first and second fuel tanks F and F through the automatic directional control valve 58. The fuel permeating or diffusion member 55 consisting of graphite fibers, which are porous and refractory material, is inserted into the fuel supply passage 50 in the manner described hereinbefore. Therefore the fuel which is gasoline when the motor is started but kerosine when the motor is once started, is permeated or diffused through the fuel permeating or diffusion member 55 and emerges at the fuel emerging end surface thereof facing the combustion chamber. This fuel is mixed with the air discharged through the discharge port 49 so that the fuel-air mixture is formed in the plug chamber 35.

In starting the motor the starting switch 95 is closed to energize the ignition system D so that the lowvoltage current flows to the center electrode 40 and the spark is produced between the center and

ground electrodes

40 and 4|. As a consequence the fuel-air mixture in the plug chamber 35 is ignited and burnt so that the fuel-air mixture in the combustion chamber 23 consisting of the air supplied from the air reservoir 48 and the fuel injected through the fuel injection device 26 is also ignited and burnt by the combustion flame in the plug chamber. In this case a naked flame remains burning at fuel emerging surface of the fuel permeating or diffusion member 55 because gasoline is supplied thereto so that the fuel-air mixture in the combustion chamber 23 may be ignited and burnt by the naked flame. Therefore the smooth motor starting may be ensured.

When the rotational speed of the motor reaches a predetermined speed after the motor has been started, the starting switch is automatically opened so that the supply of the current to the center electrode 40 is interrupted, but the naked flame remains burning in a stable manner as kerosine is supplied continuously onto the fuel emerging surface of the fuel permeating or diffusion member 55 and the fresh compressed air is also continuously supplied from the discharge port 49 of the air supply passage 45. Therefore the fresh fuel-air mixture supplied in the combustion chamber 23 may be ignited and burnt as a part of the mixture enters into the plug chamber 35.

When the motor is to be started gasoline of a high flashing point is supplied to the fuel permeating or diffusion member 55 because the force of the spring S in the automatic directional control valve 61 is in excess of the discharge pressure of the fuel injection pump 72 so that the first passage 63 is opened thereby intercommunicating between the first fuel tank F and the fuel permeating or diffusion member 55. Once the motor has been started, the economical fuel or kerosine is supplied because the force of the spring 8 becomes lower than the fuel injection pressure so that instead of the first passage 63 the second passage 64 in the automatic directional control valve 61 is opened, thereby intercommunicating the second fuel tank F and the fuel permeating member 55.

The hollow cylinder 32 of the plug chamber 35 may be immediately raised to a suitable high temperature after the motor is started because its inner wall is heated by the naked flame and its outer wall is heated by the heat liberated when the fuel-air mixture is ignited and burnt in the combustion chamber 23 so that the smooth transfer from the rotation of the rotor by the starting motor to the rotation of the rotary motor by its own force may be ensured. Furthermore the atomized particles of the fuel injected by the fuel injection device 26 impinge upon the outer surface of the hollow cylinder 32 so that they may be immediately vaporized and mixed with the fresh air charged into the combustion chamber 23 from the air reservoir 48, thereby forming well-mixed fuel-air mixture. Moreover the atomized finest particles of fuel charged into the combustion chamber 23 are heated by the hollow cylinder 32 so that the fuel-air mixture corresponding to the hot bulb in the conventional hot-bulb engine may be formed. in the instant embodiment the hollow cylinder 32 is perforated so that a part of the fuel-air mixture in the combustion chamber 23 may enter the plug chamber 35 in the fuel combustion device 27 and be ignited and burnt by the naked flame at the fuel emerging end surface of the fuel permeating or diffusion member 55. Therefore as long as the motor is running, the positive evaporation of the injected fuel and the positive ignition and burning of the fuel-air mixture may be ensured only by the heated hollow cylinder 32. Even if the temperature of the hollow cylinder 32 drops because of the decrease in load or idling without the load the naked flame in the plug chamber 35 serves to vaporize the injected fuel particles and to ignite the fuel-air mixture so that the smooth motor operation may be ensured all the time.

Even though the naked flame in the plug chamber may be small, the ionization tendency is strong because of the characteristics of the continuous burning flame so that the positive ignition may be ensured and the burning or combustion velocity may be remarkably increased. Therefore the complete combustion of the fuel-air mixture may be ensured and the positive ignition and burning of even thin fuel-air mixture may be ensured. Furthermore since the naked flame is within the plug chamber 35, there is no danger that it is blown out and it may ignite and burn the fuel-air mixture even though its volume may be varied.

As described hereinbefore when the fuel combustion device 27 of the present invention is applied to the vane type rotary motor V of the type described above, the positive smooth ignition of the fuel-air mixture in the combustion chamber 23 by the naked flame in the plug chamber may be ensured regardless of the rotational speed of the motor. Therefore the smooth and continuous motor operation may be ensured; the combustion efficiency may be remarkably increased and the reduction of the pollutants in the exhaust gases may be attained.

Second Embodiment, FIGS. and 6 Next referring to FIGS. 5 and 6, the second embodiment of the present invention will be described. The second embodiment is substantially similar in construction to the first embodiment described hereinbefore except that a thermal or glow plug G is disposed within the plug chamber 35 of the combustion device generally indicated by 270. The glow plug G generally comprises a rectangular heat receiving member 100 made of a material capable of accumulating heat such as nichrome or platinum and adapted to receive the heat from the naked flame and to dissipate the heat upon occasion. The leading end of the heat receiving member 100 is bent upwardly toward the fuel emerging end surface of the fuel permeating or diffusion member 55 and spaced apart therefrom by a predetermined distance, and the base of the heat receiving member 100 is securely joined to the inner wall of the hollow cylinder 32 by welding or the like.

In the combustion device 270 the naked flame is produced to ignite and burn the fuel-air mixture in the combustion chamber 23 in the same manner with that of the first embodiment. Furthermore even when the naked flame should be blown out in the plug chamber 35, the heat accumulated by the heat receiving member 100 of the glow plug G serves to positively and immediately ignite the fuel diffused out of the fuel permeating or diffusion member 55 so that the naked flame may be always maintained and the smooth and continuous motor operation may be ensured.

Third Embodiment, FIGS. 7 and 8 The third embodiment shown in FIGS. 7 and 8 is substantially similar in construction to the first embodiment except that a main fuel passage 500 having a fuel injection nozzle 530 opened into the plug chamber 35 in the combustion device generally indicated by 270' is formed through the main body 28 independently of the fuel supply passage 50 thereof in order to supply the fuel from the combustion device 270' to the combustion chamber 23. As best shown in FIG. 8, the main fuel injection nozzle 530 is opened into the plug chamber 35 in spaced apart relation with the air discharge port 49 of the compressed air supply passage 45, the end surface of the fuel diffusion member 55 in the fuel supply passage 50 and the ignition zone 42. The other end of the main fuel passage 500 is communicated through a fuel port 510 and a fuel supply pipe 520 to the return pipe 81 of the fuel injection device 26 (See FIG. 4) in the downstream of the throat 82. The main fuel, that is kerosine in the second fuel tank F may be injected through the main fuel injection nozzle 530 to the combustion chamber. The third embodiment, that is the combustion device 270 has an advantage that the main fuel may be charged into the combustion chamber through the combustion device in addition to the ignition and burning of the fuel-air mixture by the naked flame described in the first embodiment.

Mode of Operation of Third Embodiment, FIGS. 9 and 10 The effects and advantages of the third embodiment will become more apparent from the following description thereof which is applied to a two-stage expansion and vane type rotary motor shown in FIGS. 9 and 10 which has been previously proposed by the inventor of the present invention.

In the two-stage expansion and vane type rotary motor, the vane type rotary motor V of the type described in detail hereinbefore with reference to FIGS. 1 4 is used as a front or high-pressure stage, and a second vane type rotary motor V adapted only to expand and discharge the gas is used as a second or low-pressure stage. As shown in FIG. 10, the gears 101 and 101' carried by the rotary shafts 5 and 5' of the rotary motors V and V' are meshed with a gear 103 carried by an output shaft 102. The discharge passage 22 of the first motor V are communicated through a branched pipe 104 with supply passages 19' each leading to one of opposed two chambers 18' in the expansion half circle of the second motor V.

The first motor V is provided with the combustion device 27 of the first embodiment, and the second combustion device 270' of the third embodiment is installed air-tightly in a hole formed through the wall of the passage 105 intercommunicating between the gas discharge passage 22 of the first motor V and the gas supply passage 19' of the second motor V in such a manner that the plug chamber 35' of the second combustion device 270 may be disposed within the communication passage 105 in the upper stream of the branched pipe 104, said passage 105 serving as a part of the combustion chamber for the second motor V. The second motor V is not provided with the fuel injection device 26 (See FIGS. 1 and 4). The first and second combustion devices 27 and 270' are connected electrically to the electric ignition system D for starting the motor and hydraulically to the fuel supply systems A and B in a manner substantially similar to that of the first embodiment.

In order to supply the fuel or kerosine into the main fuel passage 500 in the combustion device 270' the main fuel passage 500 is communicated through a fuel control valve 107 in a fuel-air mixture charge control device 109 mounted upon the outer wall 4 of the cylin der 2 to the return pipe 81 of the fuel injection device 26 at the downstream of the throat 82 (See FIG. 1). The compressed air supply passage 45 in the fuel combustion device 270' is communicated with the air reservoir 48 through an air control valve 108 in the fuel-air mixture charge control device 109 (See FIG. 1). Gears Ill and 112 carried by the shafts of the control valves 107 and 108 are in mesh with each other and one of them is operatively coupled to the acceleration pedal G (See FIGS. 1 and 41.

In case of idling or running with a medium load, twostage combustion, i.e., combustion both in the motors V and V are effected, while in case of the operation with a heavy load, the combustion is effected only in the first motor V and not in the second motor V. In this case the subsequent combustion may be effected in the second motor V' for complete combustion.

Since the function of the combustion device 27 in the first motor V has been already described in detail here inbefore, only the mode of operation of the third embodiment combustion device 270' will be described in detail hereinafter.

ln starting the motor, the air and the fuel or gasoline supplied from the air reservoir 48 and the first fuel tank F respectively. into the plug chamber 35' of the combustion device 270 are mixed to form the fuel-air mixture which in turn is ignited and burnt by the spark produced in the ignition zone 42 by the electric ignition system D so as to produce a naked flame as in the case of the combustion device 27 of the first embodiment. Then the fuel-air mixture in the communication passage 105 consisting of the fuel or kerosine injected from the injection nozzle 530 of the main fuel passage 500, the combustion gas from the first motor V and the air supplied from the air reservoir 48 is ignited by the naked flame and burnt to effect combustion in the second motor V. In case of the operation with a heavy load, the fuel control valve 107 in the main fuel-air mixture charge control device 109 is closed so that the supply of the main fuel to the combustion device 270' may be interrupted. As a result the combustion in the second motor V may be interrupted in a simple manner.

As described above many advantages are obtained when the combustion device 270 of the third embodiment is used because the supply of the main fuel may be controlled as the need arises by controlling the supply of fuel to the main fuel passage 500.

Since the combustion device 270' of the third embodiment functions not only to provide the naked flame but also to supply the main fuel for the two-stage expansion and vane type rotary motor, the ignition of the fuel-air mixture after the motor has been started may be ensured by the naked flame at the diffusion surface of the fuel permeating or diffusion member consisting of porous and refractory material, utilizing the ignition capability of the naked flame having a strong ionization tendency. Therefore, the positive and quick ignition of the fuel-air mixture may be ensured under any operating conditions of the motor.

Furthermore the combustion device 270' of the third embodiment may eliminate the main fuel supply device, that is the fuel injection device 26 so that not only the combustion device but also its associated electric ignition system and the fuel supply systems may be made simple in construction and compact in size.

In summary, the present invention provides a combustion device for use with a heat motor of the type having a combustion chamber in which the fuel charged is mixed with air and burnt, comprising a cylindrical member which is fitted air-tightly into a hole formed through the wall of said combustion chamber in such a manner that a plug chamber with a bottom formed on the lower end of said cylindrical member may be in communication with said combustion chamber; an air discharge port of an air supply passage in communication with a compressed air source being opened into said plug chamber; a fuel discharge port of a fuel supply passage in communication with a fuel source being opened into said plug chamber adjacent to said air discharge port; a fuel permeating or diffusion member made of a porous and refractory material and provided with a large number of fine passage holes, said fuel permeating or diffusion member being fitted into said fuel supply passage adjacent to said fuel discharge port in such a manner that one end may face said plug chamber; and ignition means electrically connected to an electric power source for igniting the fuel-air mixture consisting of the fuel charged through said fuel permeating or diffusion member and the air charged through said air discharge port; whereby when the motor is started the fuel-air mixture in said combustion chamber is ignited by the flame produced by the ignition by said ignition means and burning of the fuel-air mixtured in said plug chamber consisting of the fuel charged through said fuel permeating or diffusion member and the air charged through said air discharge port, and after the motor has been started the fuel-air mixture in said combustion chamber is ignited by the naked flame at the fuel emerging surface of said fuel permeating or diffusion member. The combustion device in accordance with the present invention may ensure the smooth operation of a heat motor, improve the characteristics and efficiency thereof and ensure the complete combustion of the fuel-air mixture in the combustion chamber, the improvement of thermal efficiency and the reduction in pollutants in the exhaust gases.

It will be understood that the combustion device in accordance with the present invention is not limited in use only with the vane type rotary motors described hereinbefore, but it may find wide applications not only in various combustion devices or apparatus installed in houses and factories, but also in various heat motors for converting the thermal energy into the kinetic energy.

The combustion device in accordance with the present invention may be also applied not only to a boiler and a burner but also to various combustion apparatus for supplying the heat energy to steam plants, heating systems, hot water supply systems and so on. Furthermer the combustion device in accordance with the present invention may be applied to various types of steam turbines and gas turbines for aircrafts, ships, land vehicles, generators and factories. The combustion device in accordance with the present invention may be also used in the heat motors such as jet engines, steam engines and the like of the type converting the thermal energy into the kinetic energy.

It is to be understood that various modifications and variations may be effected without departing the true spirit of the present invention. For example the material of the fuel permeating or diffusion member is not limited to graphite fiber, but any other suitable porous and refractory material such as aluminum series porcelain, sintered metals and the like may be used.

What is claimed is:

1. In combination, a vane-type rotary engine and a combustion device for igniting fuel-air mixture in a combustion chamber of the vane-type rotary engine, comprising a cylindrical body air-tightly fitted to the wall of the combustion chamber and projecting into the combustion chamber,

a hollow cylinder coaxially attached to the inner end of said cylindrical body for defining therein a plug chamber opening to the combustion chamber,

an air supply passage extending through said cylindrical body and having an air discharge port opening at the inner end of said cylindrical body to said plug chamber for supplying compressed air to the plug chamber,

a fuel supply passage extending through said cylindrical body and having a fuel discharge port opening at the inner end of said cylindrical body to said plug chamber adjacent to said air discharge port for supplying fuel to the plug chamber,

a fuel permeating member or wick fitted into said fuel discharge port with one end thereof facing said plug chamber,

spark ignition means disposed in said plug chamber adjacent to said air and fuel discharge ports and connected to an electric power source for generating a spark to ignit fuel-air mixture in said plug chamber, and

means for cutting off the electrical connection between said spark ignition means and said electric power source when the speed of said engine reaches a predetermined speed,

and further including a first fuel source for a high grade fuel, a second fuel source for a low grade fuel, a directional control valve for communicating either of said first and second fuel sources with said fuel supply passage, and means for controlling said directional control valve to communicate said first fuel source with said fuel supply passage when the speed of said motor is less than a predetermined value and said second fuel source with said fuel passage when the speed of said motor is more than said predetermined value.

2. The combination as claimed in claim 1, further comprising a main fuel injection nozzle opening at the inner end of said cylindrical body to said plug chamber and a main fuel supply passage extending through said cylindrical body for communicating between said second fuel source and said injection nozzle.

3. The combination as claimed in claim 2, wherein said vane-type rotary engine comprises a two-stage expansion vane-type rotary engine system comprising a first high-pressure vane-type rotary engine, a second low-pressure vane-type rotary engine and a conduit for intercommunicating between the exhaust port of said first engine and the suction port of said second engine, wherein said cylindrical body is air-tightly fitted to the wall of said conduit with said plug chamber disposed within the conduit.

Claims

1. In combination, a vane-type rotary engine and a combustion device for igniting fuel-air mixture in a combustion chamber of the vane-type rotary engine, comprising a cylindrical body air-tightly fitted to the wall of the combustion chamber and projecting into the combustion chamber, a hollow cylinder coaxially attached to the inner end of said cylindrical body for defining therein a plug chamber opening to the combustion chamber, an air supply passage extending through said cylindrical body and having an air discharge pOrt opening at the inner end of said cylindrical body to said plug chamber for supplying compressed air to the plug chamber, a fuel supply passage extending through said cylindrical body and having a fuel discharge port opening at the inner end of said cylindrical body to said plug chamber adjacent to said air discharge port for supplying fuel to the plug chamber, a fuel permeating member or wick fitted into said fuel discharge port with one end thereof facing said plug chamber, spark ignition means disposed in said plug chamber adjacent to said air and fuel discharge ports and connected to an electric power source for generating a spark to ignit fuel-air mixture in said plug chamber, and means for cutting off the electrical connection between said spark ignition means and said electric power source when the speed of said engine reaches a predetermined speed, and further including a first fuel source for a high grade fuel, a second fuel source for a low grade fuel, a directional control valve for communicating either of said first and second fuel sources with said fuel supply passage, and means for controlling said directional control valve to communicate said first fuel source with said fuel supply passage when the speed of said motor is less than a predetermined value and said second fuel source with said fuel passage when the speed of said motor is more than said predetermined value.