Flame-ejecting spark plug, and internal combustion engine and automobile having same

Abstract

Disclosed are a flame-ejecting spark plug, and an internal combustion engine and an automobile having same. On the basis of a conventional spark plug, a space near to an electrode is closed to form a cavity (10), an end face is provided with at least one first hole (11), and a side face is provided with at least one second hole (13). A mixture of air and fuel enters the cavity (10) through the first hole (11) and the second hole (13). Electric discharge between the electrodes produces a spark igniting the combustible gas within the cavity (10), and the flame extends in the cavity (10) and the temperature and pressure rise. The flame is ejected from the first hole (11) and the second hole (13) to form a plurality of columnar flames, and the flame penetrates the combustible gas in a combustion chamber and a cylinder to realize stereoscopic ignition, large-area ignition and high-energy ignition of the combustible gas in the combustion chamber.

Claims

1. A flame-ejecting spark plug, which is characterized in that, on the basis of a conventional spark plug, a space near electrodes is closed to form a cavity, one or more first holes are opened on the end face of the cavity, one or more second holes are opened on the side face of the cavity, a mixture gas of air and fuel enter the cavity through the first hole and the second hole, and sparks are generated between the electrodes to ignite the combustible gas in the cavity, as the flame in the cavity extends and the temperature and pressure rise, the flame is ejected from the first hole and the second hole to form a columnar flame, and the flame enters the combustible gas in a combustion chamber and a cylinder to realize stereoscopic ignition and high-energy ignition of the combustible gas in the combustion chamber and the cylinder; an numerical value of a distance from the middle position between a cathode and an anode of the electrodes to the edge of the nearest first hole is 0.1-0.9% of the volume of the cavity, at the same time, the volume of the cavity inside the spark plug is divided into two parts along the section of the central axis of the spark plug in the middle position between the cathode and the anode of the electrodes, the volume close to the first hole accounts for one-fifth to one-half of the total volume; the combustion pressure in the spark plug cavity can make the speed of the columnar flame ejected from the first hole reach 150 m/s or more, and the preferred speed is 225-375 m/s; the injection distance of the columnar flame ejected from the first hole exceeds the distance from the top of the combustion chamber to the top of the piston when the piston is in the middle position between the bottom dead center and the top dead center.

2. The flame-ejecting spark plug of claim 1, wherein the first hole on the end face of the cavity and the second hole on the side face have a jet angle in the radial direction of the cavity, or have a tilt angle in the circumferential direction while having the jet angle; the shape of jet hole is one of circle, circular ring, leaf, semicircle, rectangle, triangle, trilobal, or a combination of the above shapes; the volume close to the first hole accounts between one-quarter and one-third of the total volume, so that the columnar flame of the first hole has a fast spraying speed and a long spraying distance.

3. The flame-ejecting spark plug of claim 1, wherein the spark plug is replaced by only the first hole, but not the second hole.

4. The flame-ejecting spark plug of claim 2, wherein the cathode and anode of the electrodes are arranged in the direction perpendicular to the central axis of the spark plug, that is, the cathodes of the electrodes are distributed on both sides or four sides of the anode.

5. An internal combustion engine, which is characterized in that a kind of the flame-ejecting spark plug as described in claim 1 is selected to use as an ignition device, the fuel and air of the internal combustion engine are used as the main energy source for ignition.

6. The internal combustion engine of claim 5, wherein the engine simultaneously uses two or more flame-ejecting spark plugs for ignition, or uses a combination of the flame-ejecting spark plug and a traditional spark plug as the ignition device.

7. The internal combustion engine of claim 5, wherein a stratified combustion technology and control scheme are adopted, or a lean combustion technology and control scheme are adopted, or the stratified combustion and the lean combustion technology and control scheme are adopted at the same time.

8. The internal combustion engine of claim 5, wherein the compression ratio of the cylinder is 10:1 to 21:1; or it is provided with a turbocharging device at the same time; or it is provided with a turbocharging device and a supercharging device at the same time.

9. A flame-ejecting spark plug of claim 1 is used as the ignition device of a turbine engine or a gas turbine.

10. An internal combustion engine vehicle or hybrid electric vehicle, which is characterized in that the engine as described in claim 5 is used as a power device.

11. The internal combustion engine, which is characterized in that a kind of the flame-ejecting spark plug as described in claim 2 is selected to use as an ignition device, the fuel and air of the internal combustion engine are used as the main energy source for ignition.

12. The internal combustion engine, which is characterized in that a kind of the flame-ejecting spark plug as described in claim 3 is selected to use as an ignition device, the fuel and air of the internal combustion engine are used as the main energy source for ignition.

13. The internal combustion engine, which is characterized in that a kind of the flame-ejecting spark plug as described in claim 4 is selected to use as an ignition device, the fuel and air of the internal combustion engine are used as the main energy source for ignition.

14. The internal combustion engine vehicle or hybrid electric vehicle, which is characterized in that the engine as described in claim 6 is used as a power device.

15. The internal combustion engine vehicle or hybrid electric vehicle, which is characterized in that the engine as described in claim 7 is used as a power device.

16. The internal combustion engine vehicle or hybrid electric vehicle, which is characterized in that the engine as described in claim 8 is used as a power device.

17. The internal combustion engine vehicle or hybrid electric vehicle, which is characterized in that the engine as described in claim 9 is used as a power device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, among them:

(2) FIG. 1 is an example of the structure of a flame-ejecting spark plug, in which: 1 wiring nut, 2 insulator, 3 metal rod, 4 inner washer, 5 shell, 6 conductor glass, 7 sealing washer, 8 inner washer, 9 insulator skirt, 10 semi closed cavity, 11 end face spray hole, 12 center electrode (anode), 13 side spray hole, 14 cathode electrode. The combustible gas in the combustion chamber enters the semi closed cavity 10 through the end face spray hole 11 and the side spray hole 13. The gap between the center electrode 12 and the cathode electrode 14 is ionized and discharged under the action of high voltage, or plasma discharge is formed under the action of sub-high frequency and high voltage, generating electric spark to ignite the combustible gas in the semi closed cavity 10. The combustible gas burn and forms high temperature and high pressure fire (flame) in the semi closed cavity 10. The compressed flame is ejected from the end face spray hole 11 to form a columnar flame. The columnar flame penetrates the combustible gas in the combustion chamber and cylinder and reaches the end face of the piston top to ignite the combustible gas in multiple points. Inside the semi-closed cavity, a protruding structure may be provided on the cathode electrode 14 for adjusting the distance from the middle position of the gap between the cathode and the anode electrode to the end face of the flame-ejecting spark plug. The side jet hole 13 also ejects a columnar flame to ignite the combustible gas in the combustion chamber.

(3) FIG. 2A shows the local structure of the flame-ejecting spark plug, including 15 threads, 16 conducting rods, 17 side spray holes, 18 end spray holes, 19 spray angle, 20 insulator, 21 semi closed cavity, 22 shell, electrode (cathode), 23 center electrode. FIG. 2B is a schematic end face view of FIG. 2A. All holes are at the same distance from the middle of the gap between the electrodes of cathode and anode. FIG. 2C is a schematic view of the end face corresponding to another arrangement scheme of the end face spray hole in FIG. 2A.

(4) FIG. 3A shows the local structure of the flame-ejecting spark plug, including: 15 thread, 16 conducting rod, 17 side spray hole, 18 end spray hole, 19 spray angle, 20 insulator, 21 semi closed cavity, 22 shell, electrode (cathode), 23 center electrode, 24 center spray hole.

(5) FIG. 3B is a schematic end face view of FIG. 3A.

(6) FIG. 3C is a schematic diagram of the end face view corresponding to another arrangement scheme of the end face spray hole in FIG. 3A.

(7) FIGS. 4A-4B are the partial structure diagrams of the flame-ejecting spark plug, including: 15 thread, 16 conducting rod, 17 side spraying hole, 18 end spraying hole, 19 spraying angle, 20 insulator, 21 semi closed cavity, 22 shell, electrode (cathode), 23 center electrode, 25 conductive glass, 26 annular spraying hole. FIG. 4B is a schematic view of the end face structure of FIG. 4A.

(8) FIGS. 5A-5C is the schematic diagram of the shape of the spray hole of the flame-ejecting spark plug, in which FIG. 5A is the leaf shape, FIG. 5B is the semicircle ring shape and FIG. 5C is the rectangle shape.

(9) FIG. 6 is a partial drawing of the conventional spark plug in the prior art, showing that the electrode is in an open state.

(10) FIG. 7 is a partial drawing of the conventional spark plug in the prior art, showing that the electrode is in a half open state. This structure of spark plug, the electrode discharge produces sparks to ignite the combustible gas in the combustion chamber, and the flame spreads around the electrode. As compared with FIG. 6, the combustion of combustible gas inside the cathode (negative electrode) will form a pressure greater than that outside, which is conducive to promoting the expansion of the flame surface. FIGS. 4A-4B is different from FIG. 7 in that there is not only a quantitative change in the coverage area, but also a qualitative change in technical ideas, technical measures and technical effects, which is a change from quantitative change to qualitative change. Therefore, the technical solution of FIGS. 4A-4B is creative.

(11) FIG. 8 is a schematic diagram of an internal combustion engine using a flame-ejecting spark plug of the present application, in which: 10 engine, 12 crankshaft, 14 piston, 15 cylinder, 16 combustion chamber, 18 exhaust valve, 20 intake valve, 22 flame-ejecting spark plug, 24 columnar flames.

(12) FIG. 9 shows the structure of a kind of flame-ejecting spark plug, in which: 28 is gaps to replace the first holes and second holes, and 4 gaps are not connected at the end face of the spark plug. The flame in the cavity enters the combustion chamber and the cylinder through four gaps, and the combustible gas in the combustion chamber and the cylinder is divided and ignited.

(13) In the drawings, the same parts use the same reference numerals. The figures are not to the actual scale.

DETAILED DESCRIPTION

(14) FIG. 1 is an example of the structure of a flame-ejecting spark plug, in which: 1 wiring nut, 2 insulator, 3 metal rod, 4 inner washer, 5 shell, 6 conductor glass, 7 sealing washer, 8 inner washer, 9 insulator skirt, 10 semi closed cavity, 11 end face spray hole, 12 center electrode (anode), 13 side spray hole, 14 cathode electrode. The combustible gas in the combustion chamber enters the semi closed cavity 10 through the end face jet hole 11 and the side face jet hole 13. The gap between the center electrode 12 and the cathode electrode 14 is ionized and discharged under the action of high voltage, or plasma discharge is formed under the action of sub high frequency and high voltage, generating spark to ignite the combustible gas in the semi closed cavity, and the combustible gas burn and forms high temperature and high pressure fire in the semi closed cavity. The flame is ejected from the end hole to form a columnar flame. The columnar flame penetrates the combustible gas in the combustion chamber and the cylinder and reaches the end face of the piston top to ignite the combustible gas at multiple points. The side jet hole 13 also ejects a columnar flame to ignite the combustible gas in the combustion chamber.

(15) The better technical effect is that after the combustion of the fuel and air in the cavity, the flame is ejected from the end hole, which can penetrate the mixture of fuel and air in the combustion chamber and cylinder to reach the top of the piston, and the higher the dispersion of the flame column in the combustible gas, the better the ignition effect is, and the larger the specific surface of the flame column is, the better the ignition effect is. The columnar flame beams are dispersed at a certain angle, so that the partitioned volume of the fuel and air mixture (combustible gas) around the end of the flame beam is approximately the same, so that the combustion end time of the combustible gas around the flame beam is approximately the same. The end and side holes have a certain jet angle along the radial direction. The better design is that these spray holes have a certain angle along the circumferential direction at the same time, so that the path of the flame beam passing through the combustible gas is longer, and the combustible gas is stirred to form a rotating air flow.

(16) FIG. 8 is a schematic diagram of an internal combustion engine using a flame-ejecting spark plug of the present application, wherein the columnar flame 24 ejected by the flame-ejecting spark plug 22 disperses into the combustible gas in the combustion chamber 16 and the cylinder 15, and penetrates the combustible gas to the end surface at the top of the piston 14.

(17) The Preferred Technical Solution Includes:

(18) 1) Place the side spray hole near the end face of the cavity. The position of the side jet hole near the root of the semi closed cavity (far away from the end face) is conducive to the entry of combustible gas into the cavity and is not conducive to the increase of the flame jet pressure.

(19) 2) There are many choices of jet angle and tilt angle, the number and shape of jet holes, the proportion of the total area of end jet holes to the end area of cavity, and the proportion of the total area of jet holes to the effective volume of cavity. These parameters will affect the combustion speed, temperature and pressure of combustible gas in the cavity, the injection speed and distance after the flame is ejected from the injection hole, and the state of flame dispersion in the combustible gas in the combustion chamber and cylinder. The better effect is that the columnar flame can penetrate the combustible gas, but it will not impact the cylinder and piston, and will not produce large vibration. According to the above effects and purposes, it is the common sense of the technical personnel in the industry to select the above parameters of the spark plug.

(20) 3) In view of the increasing trend of combustion speed and combustion temperature, lean combustion can be realized by increasing air-fuel ratio in the engine.

(21) 4) Further, in order to reduce the excessive oxygen content in the fuel-air mixture, reusing part of exhaust gas is also an optimized technical scheme.

(22) According to the structure and performance requirements of internal combustion engine, the model and parameters of the flame-ejecting spark plug are selected, which is a common sense in the industry.

(23) In order to increase the injection pressure and ensure that the equivalence coefficient , of the air-fuel ratio in the semi closed cavity of the flame-ejecting spark plug is near 1, the technical scheme of supplying fuel to the flame-ejecting spark plug alone can be adopted. Alternatively, it is also an option to set a cavity in the combustion chamber of the internal combustion engine, configure the fuel injection system for the cavity separately, and then install the traditional spark plug in the cavity. The disadvantage of the above two technical solutions is that the cost of structure complexity increases. The preferred alternative of this application is to design the injection direction of the fuel injection nozzle of the internal combustion engine to be relatively close to the position of the end face of the flame-ejecting spark plug. The internal combustion engine with multiple fuel injection is conducive to the diffusion of fuel into the cavity.

(24) The side holes may not be set to increase the injection pressure and distance. The disadvantage is that it is not conducive to the diffusion of fuel from the combustion chamber into the semi closed cavity.

(25) As the compression stroke piston approaches the TDC (top dead center), the density of combustible gas in the combustion chamber increases, and the energy accumulated by the combustible gas in the cavity of the flame-ejecting spark plug increases gradually, and the intensity (energy) of the flame jet increases when the ignition occurs. The distance of combustible gas to be penetrated by the flame beam sprayed by the flame-ejecting spark plug shall be shortened to facilitate penetration. Therefore, when the ignition start time is close to the TDC, the ignition effect is better.

(26) In addition to the circular shaped hole, the special shaped hole is selected, as shown in FIGS. 5A-5C, it is beneficial to increase the specific surface of the columnar flame and increase the ignition efficiency.

(27) Embodiment (Example) 1: the parameters of a typical spark plug are shown in FIG. 3, and the effective volume in the semi closed cavity 21 shown in FIGS. 3A and 3B is 0.6 cm3. The number of end face spray holes is 7 (including 1 center spray hole 24), and the holes shape is circle. The injection angle of the central orifice 24 is 0. The radial spray angle of the other six end face spray holes 18 is 30 degrees, and the circumferential inclined angle is 20 degrees. The total area of the end face holes 18 (including the center orifice 24) is 25% of the circular section area of the cavity volume (corresponding to the end face). The number of side spray holes 17 is 2, symmetrical distribution, the hole shape is circular, the hole diameter of side spray holes is of the end spray holes, the radial spray angle of side spray holes 17 is 45 degrees, and the circumferential inclined angle is 15 degrees.

(28) When FIG. 3C is used instead of FIG. 3B as the layout of the end orifice, the number of the end holes 18 (including the center orifice 24) is 4, and the total area of the end holes 18 (including the center hole 24) is 20% of the volume circular section area of the cavity. Compared with FIG. 3B, the total area of the end face holes 18 (including the center hole 24) and the circular section area of the cavity volume (corresponding to the end face) are reduced, and the injection pressure is increased. At the same time, the number of the end face hole is reduced, and the area of a single hole is increased, so the ejecting distance is increased.

(29) Embodiment 2, the center electrode 23 of FIG. 2A is hidden in the shell 22 of the semi closed cavity 21. Compared with the semi exposed center electrode 23 of FIG. 3A and the exposed center electrode 23 of FIG. 4A, the direct ignition of the electrode spark to the combustible gas in the combustion chamber is avoided. The ignition action is divided into two parts, one is the electrode spark to ignite the combustible gas in the semi closed cavity 21, the other is the semi closed cavity 21 ejecting flames from the holes after the combustion of the combustible gas in the semi closed cavity 21, to ignite the combustible gas in the combustion chamber and cylinder. In this way, the time interval of the combustible gas to be igniting in the combustion chamber and cylinder between the top and bottom of combustion chamber and even the depth of cylinder is shortened. The disadvantage is that the concentration of combustible gas near the electrode is greatly affected by the diffusion time of fuel in the combustion chamber. This kind of spark plug is more suitable to be used as the ignition device of the internal combustion engine with fully premixed fuel, or as the ignition device of the internal combustion engine with multiple fuel injection into the cylinder and relatively high fuel concentration at the end of the spark plug in the combustion chamber.

(30) Embodiment 3, the position of positive and negative electrodes (23 and 22) of the spark plug shown in FIG. 4A is at the edge of the boundary between the semi closed cavity 21 and the combustion chamber (this edge is exactly the gap position between the positive and negative electrodes, and also the position of the annular jet hole 26), which is exposed outside the semi closed cavity 21. The concentration and air-fuel ratio of the combustible gas around the electrode are the same as most areas of the combustion chamber. The reliability of electrode ignition is almost independent of the diffusion effect of combustible gas into semi closed cavity 21. In addition to the ignition requirements of general internal combustion engines, this kind of the flame-ejecting spark plug is more suitable for the ignition device of lean burn engines, such as HCCI.

(31) When spark ignition device is used in the start-up phase of HCCI gasoline engine, it can be ignited directly when the equivalence coefficient , of air-fuel ratio is greater than 1.

(32) Embodiment 4: since the spark plug of the application has high ignition intensity and energy, and belongs to multi-point ignition, the spark plug of the application can be used as a forced ignition device of HCCI gasoline engine. On the basis of various technical measures and technical schemes of existing HCCI gasoline engine, the heat release equivalent and depth of chemical reaction between pre injected fuel and high-temperature exhaust gas and air mixture are reduced. The energy required for compression ignition shall be kept at a safe distance to ensure that the fuel-air mixture will not have early combustion and detonation. Then, when the compression stroke piston reaches or near the top dead center position, the spark plug of the application is used for ignition as the trigger of homogeneous charge compression ignition (HCCI) to realize forced ignition. That is to say, the energy of forced ignition of the flame ejecting spark plug is used to trigger HCCI ignition. In this case, HCCI gasoline engine can operate freely and easily in the working environment of changing speed and load greatly, and it will not lost-fire as ignition later or knock because of early combustion, so it has the equipment conditions as a single power unit of automobile.

(33) Embodiment 5, FIGS. 5A-5C shows the sections of several special-shaped spray holes, in which FIG. 5A is a leaf shape, FIG. 5B is a half circular ring shape and FIG. 5C is a rectangle shape. In addition to the section of the special-shaped orifice shown in FIGS. 5A-5C, the section of other special-shaped orifice includes but is not limited to the torus shape (a ring shape with one or more gaps), triangle shape, triangle with three sides recessed, trilobal, trilobal with three rectangles connected, and the combination of the above shapes.

(34) Embodiment 6, in order to increase the ignition energy of the spark plug and the effective volume of the semi closed cavity, the size of the shell shoulder on the left side of the sealing washer 7 in FIG. 1 is enlarged, and the size of the shell on the right side of the shoulder and the washer 7 are enlarged at the same time. If necessary, seal washer 7 and the shoulder on the left side can be the area with the largest spark plug diameter. For example, increase the diameter of thread 15 in FIGS. 2A, 3A and 4A from 14 mm to 20 mm (include 14-20 mm). Or extend the length of the semi closed cavity in the axial direction of the flame-ejecting spark plug.

(35) Embodiment 7, the spark plug is applied to the turbine engine as the ignition device. The air flow in the semi closed cavity is less affected by the high-speed air flow disturbance of the external combustion chamber, and the ignition stability and reliability are high.

(36) Embodiment 8, the principle of the spark plug of this application is used as the ignition rod in industrial furnace and other devices.

(37) The application scope of the spark plug includes but is not limited to the above embodiments. The structure, appearance and shape of the spark plug include but are not limited to those shown in FIG. 1, FIGS. 2A-2C, FIGS. 3A-3C, FIGS. 4A-4B, and FIGS. 5A-5C.

(38) Embodiment 9, as shown in FIG. 9, is a kind of spark plug, wherein: 28 is the gap replacing the first hole and the second hole, 4 gaps evenly divide the end face and the side face of the semi closed cavity of the spark plug, and are not connected at the end face of the spark plug. The flame ejecting from the semi closed cavity enters the combustion chamber and the cylinder through the four gaps, and the combustible gas in the combustion chamber and the cylinder is divided and ignited. Four gaps can be replaced by three equally divided or more than five.