Active pre-combustion chamber with adjustable jet velocity

Abstract

The invention provides an active pre-combustion chamber with an adjustable jet velocity. The active pre-combustion chamber comprises a pre-combustion chamber shell, a pre-combustion chamber top cover is arranged at the top of the pre-combustion chamber shell, a pre-combustion chamber cavity is formed between the pre-combustion chamber top cover and the pre-combustion chamber shell, and a spray hole is formed in the bottom of the pre-combustion chamber shell; an ejector communicated with the pre-combustion chamber cavity is mounted on the pre-combustion chamber top cover, at least two ignition electrodes are arranged in the pre-combustion chamber cavity and penetrate through the pre-combustion chamber top cover, and a spark gap is formed between one end, arranged in the pre-combustion chamber cavity, of each ignition electrode and an earth pole in the pre-combustion chamber shell; the other end of the ignition electrode extends to the upper end of the pre-combustion chamber top cover; the structure is simple and compact, the multiple ignition electrodes are integrated in the limited pre-combustion chamber cavity to replace an original spark plug, the combustion pressure in the pre-combustion chamber is changed by controlling the ignition phase difference of the multiple ignition electrodes, and therefore the flame jetting speed in the pre-combustion chamber is adjusted.

Description

Technical Field

[0001] The invention relates to the technical field of gas engines, and in particular to an active pre-combustion chamber with adjustable jet velocity. Background Art

[0002] Internal combustion engines emit nitrogen oxides NOx during operation, and the amount of NOx emissions increases with the increase in combustion temperature. For this reason, using a leaner fuel-air mixture can lower the combustion temperature in the combustion chamber, thereby reducing the amount of NOx emitted. However, an overly lean fuel-air mixture is likely to be incompletely burned, reducing the efficiency of the spark plug's induced combustion. Especially in large-cylinder engines, it may take a relatively long time for the flame to spread throughout the combustion chamber. In order to reduce the probability of incomplete combustion, setting up a pre-combustion chamber is a feasible method, and it is also the current development direction of large-cylinder engines.

[0003] The active pre-combustion chamber in the prior art has an injector and a spark plug integrated inside, and is provided with a spray hole connected to the main combustion chamber. A relatively concentrated fuel-air mixture is ignited in the pre-combustion chamber to form a flame jet, thereby igniting the relatively lean fuel-air mixture in the main combustion chamber. The flame jet from the pre-combustion chamber is usually sufficient to completely burn the lean mixture in the main combustion chamber. However, due to space limitations, the existing active pre-combustion chamber can generally only install one spark plug, making it difficult to effectively control the speed of the flame jet in the pre-combustion chamber and cannot adapt well to the operating requirements of different engines.

[0004] In order to solve the problem of combustion speed regulation, a technical solution is disclosed in a time-space controllable high-energy ignition device with application number 201810206018.5, including a power supply module, a control module, a boost circuit, an ignition drive circuit, an ignition coil and a spark plug. The power supply module is used to power the control module and the boost circuit; the control module is connected to the first input end of the ignition coil through the ignition drive circuit, and the control module controls the opening and closing of the ignition drive circuit; the second input end of the ignition coil is connected to the output end of the boost circuit; the first output end of the ignition coil is grounded, and the second output end is connected to the spark plug through a high-voltage wire; the invention boosts the voltage through the boost circuit, which is conducive to the control of multiple ignitions; the invention controls multiple ignition wires respectively through the control module The circles can stagger their respective energy storage moments and discharge moments, overcoming the disadvantage of long inductive energy storage time. At the same time, the ignition moment of each spark plug can be controlled independently, forming multi-point ignition in space, and the ignition moments of each point can be staggered in time; however, the application mainly focuses on a high-energy ignition solution, which is more suitable for engines with spark plugs directly installed. Compared with direct spark plug ignition, active pre-combustion chambers can achieve multi-point ignition, large-volume ignition, local turbulent combustion, etc., especially near-theoretical air-fuel ratio can be achieved in the active pre-combustion chamber, thereby achieving global ultra-lean combustion; however, the active pre-combustion chamber has a complex structure and limited internal space, and the high-energy ignition device of the prior art cannot be applied. It is challenging to achieve jet velocity control in a small space.

[0005] In summary, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the invention

[0006] In view of this, the present invention provides an active precombustion chamber with adjustable jet velocity, comprising a precombustion chamber shell, a precombustion chamber top cover is arranged on the top of the precombustion chamber shell, a precombustion chamber cavity is formed between the precombustion chamber top cover and the precombustion chamber shell, and a spray hole is arranged at the bottom of the precombustion chamber shell; an injector connected to the precombustion chamber cavity is installed on the precombustion chamber top cover, at least two ignition electrodes are arranged in the precombustion chamber cavity, the ignition electrode passes through the precombustion chamber top cover, and a spark gap is formed between one end of the ignition electrode arranged in the precombustion chamber cavity and a ground electrode in the precombustion chamber shell, and the other end of the ignition electrode extends to the upper end of the precombustion chamber top cover.

[0007] As a preferred solution, the portion of the ignition electrode located inside the pre-combustion chamber top cover is covered with an insulator.

[0008] As a preferred embodiment, the ignition electrode includes a center electrode and a lead-out electrode, wherein one end of the center electrode is arranged in the pre-combustion chamber cavity, and the other end of the center electrode extends to the inside of the pre-combustion chamber top cover; one end of the lead-out electrode is arranged in the inside of the pre-combustion chamber top cover and connected to the center electrode, and the other end of the lead-out electrode extends to the upper end of the pre-combustion chamber top cover.

[0009] As a preferred solution, the central electrode and the lead-out electrode are connected via a resistor seal.

[0010] As a preferred solution, one end of the central electrode arranged in the pre-combustion chamber cavity is provided with a bent portion, and the spark gap is between the bent portion and the ground electrode.

[0011] As a preferred solution, the ground pole is protrudingly arranged on the side wall inside the pre-combustion chamber shell.

[0012] As a preferred solution, the pre-combustion chamber top cover is connected to the pre-combustion chamber shell by threads.

[0013] As a preferred solution, a sealing gasket is provided between the bottom of the pre-combustion chamber top cover and the pre-combustion chamber shell.

[0014] As a preferred solution, the pre-combustion chamber cavity is connected to the main combustion chamber through a spray hole.

[0015] As a preferred solution, the ignition electrode is connected to an electronic control unit.

[0016] The present invention has a simple and compact structure, and integrates multiple ignition electrodes in a limited pre-combustion chamber cavity to replace the original spark plug. By controlling the ignition phase difference of the multiple ignition electrodes, the combustion pressure in the pre-combustion chamber is changed, thereby adjusting the flame injection speed in the pre-combustion chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of the structure of this application; [Description of Reference Numerals] Among them, 1-precombustion chamber shell, 2-precombustion chamber top cover, 3-sealing gasket, 4-precombustion chamber cavity, 5-spray hole, 6-injector, 7-ground electrode, 8-spark gap, 9-bending part, 10-insulator, 11-center electrode, 12-lead electrode, 13-resistance sealing material. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0020] It should be noted that all expressions using "one" and "two" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "one" and "two" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0021] As mentioned in the background technology above, the inventor of the present application recognizes that the active pre-combustion chamber in the prior art has an injector and a spark plug integrated therein, and is provided with a spray hole connected to the main combustion chamber, and a relatively dense fuel-air mixture is ignited in the pre-combustion chamber to form a flame jet, thereby igniting a relatively lean fuel-air mixture in the main combustion chamber, and the flame jet from the pre-combustion chamber is usually sufficient to completely burn the lean mixture in the main combustion chamber. However, the existing active pre-combustion chamber has limited space, and the existing spark plug includes a wire nut, an insulator, a wire screw, a center electrode, a side electrode, and a shell, etc., which, as a mature product, has a fixed model and size. Therefore, generally, only one spark plug can be installed in the narrow pre-combustion chamber space, and it is difficult to effectively control the speed of the flame jet in the pre-combustion chamber, and it cannot adapt well to the working conditions of different engines. Although in some solutions of the prior art, there are high-energy ignition devices that can achieve multi-point ignition, large-volume ignition, local turbulent combustion, etc., due to the complex structure and limited internal space of the active pre-combustion chamber, the high-energy ignition device of the prior art cannot be applied. In order to solve the above problems in the prior art, the present application proposes one or more embodiments to be described below.

[0022] Embodiment 1: like Figure 1 As shown, the present embodiment provides an active precombustion chamber with adjustable jet velocity, comprising a precombustion chamber shell 1, a precombustion chamber top cover 2 is arranged on the top of the precombustion chamber shell 1, and the precombustion chamber top cover 2 is connected to the precombustion chamber shell 1 by threads, more specifically: a mounting shoulder is arranged on the inner side of the precombustion chamber shell 1, and the precombustion chamber top cover 2 is mounted on the mounting shoulder, and a sealing gasket 3 is arranged at the position where the lower end of the precombustion chamber top cover 2 contacts the mounting shoulder to prevent leakage of the fuel-air mixture; a precombustion chamber cavity 4 is provided between the precombustion chamber top cover 2 and the precombustion chamber shell 1, and a spray hole 5 is arranged at the bottom of the precombustion chamber shell 1, and the precombustion chamber cavity 4 is connected to the main combustion chamber through the spray hole 5; an injector 6 connected to the precombustion chamber cavity 4 is installed on the precombustion chamber top cover 2, and the injector 6 is used to inject fuel into the precombustion chamber cavity 4 to form a relatively concentrated fuel-air mixture. Preferably, the injector 6 is penetrated through the center of the precombustion chamber top cover 2.

[0023] An ignition electrode is arranged in the precombustion chamber cavity 4, and the ignition electrode penetrates the precombustion chamber top cover. A spark gap 8 is formed between one end of the ignition electrode arranged in the precombustion chamber cavity 4 and a ground electrode 7 on the inner side of the precombustion chamber shell 1. Specifically, a plurality of protruding ground electrodes 7 are arranged on the side wall on the inner side of the precombustion chamber shell 1. One end of the ignition electrode extends into the precombustion chamber cavity 4 and is provided with a bending portion 9, and a spark gap 8 is formed between the bending portion 9 and the ground electrode 7. Sparks can be generated in the spark gap 8. Since the ground electrode 7 is located on the inner side of the precombustion chamber shell 1, and the end face of the ground electrode 7 is at a certain distance from the inner wall of the precombustion chamber shell 1, the spark gap 8 can be effectively reduced. The wall heat transfer effect when the initial fire core is generated in the flower gap 8 helps the internal combustion engine to work smoothly during cold start; the other end of the ignition electrode extends to the upper end of the pre-combustion chamber cover 2, and there are at least two ignition electrodes. At least two ignition electrodes are evenly arranged along the circumference around the injector 6 according to the center of the injector 6. The specific number of ignition electrodes can be set according to actual needs. In this embodiment, two ignition electrodes are preferably arranged, and the outer side of the part of the ignition electrode located inside the pre-combustion chamber cover 2 is coated with an insulator 10. The insulator 10 preferably uses a ceramic sheath to isolate the ignition electrode from the pre-combustion chamber cover 2.

[0024] The ignition electrode includes a center electrode 11 and a lead-out electrode 12, wherein one end of the center electrode 11 is arranged in the precombustion chamber cavity 4, and the other end of the center electrode 11 extends to the inside of the precombustion chamber top cover 2; one end of the lead-out electrode 12 is arranged in the precombustion chamber top cover 2 and connected with the center electrode 11, and the other end of the lead-out electrode 12 passes through the precombustion chamber top cover 2 and extends to the upper end of the precombustion chamber top cover 2, and the center electrode 11 and the lead-out electrode 12 are connected by a resistor seal 13, and the resistor seal 13 plays a role in reducing electromagnetic interference and sealing; one end of the center electrode 11 extends into the precombustion chamber cavity 4 and is provided with a bending portion 9, and a spark gap 8 is formed between the bending portion 9 and the ground electrode 7.

[0025] More preferably, the ignition electrode is connected to an electronic control unit (ECU), which controls the ignition timing of multiple ignition electrodes respectively. By setting the ignition phase difference between the multiple ignition electrodes, the combustion pressure in the pre-combustion chamber cavity 4 can be effectively controlled, thereby adjusting the flame jet speed to adapt to different engine operating conditions.

[0026] The working principle of the present invention is as follows: when the internal combustion engine is working, the piston presses fresh air into the pre-combustion chamber cavity 4 through the spray hole 5 during the compression stroke, and when the piston is close to the top dead center, the injector 6 sprays fuel into the pre-combustion chamber cavity 4, and the ignition electrode generates sparks, which ignite the fuel-air mixture in the pre-combustion chamber cavity 4 and form a flame jet, and the flame jet ignites the lean fuel-air mixture in the main combustion chamber through the spray hole 5.

[0027] To summarize, the existing spark plugs include terminal nuts, insulators, terminal screws, center electrodes, side electrodes and shells, etc. As mature products, they have fixed models and sizes. At most, only one spark plug can be installed in the narrow pre-combustion chamber space. In order to break through the space limitation of the pre-combustion chamber, the present invention uses an ignition electrode to replace the traditional spark plug, and integrates the ignition electrode and other necessary ignition components in the pre-combustion chamber structure, which saves space without affecting the ignition performance and realizes the arrangement of multiple ignition electrodes in the limited pre-combustion chamber space. The present invention has a simple and compact structure, and multiple ignition electrodes are integrated in the limited pre-combustion chamber cavity to replace the original spark plug. By controlling the ignition phase difference of the multiple ignition electrodes, the combustion pressure in the pre-combustion chamber is changed, thereby adjusting the flame injection speed in the pre-combustion chamber.

[0028] The pre-combustion chamber housing 1 may include a straight tube portion, an inverted cone portion and a tip accommodating portion. The inverted cone portion is connected to the bottom of the straight tube portion, and can play a role in guiding the flame jet to flow downward. The tip of the inverted cone portion forms an opening, and the tip accommodating portion is connected to the opening, and the flame jet is guided by the inverted cone portion and converges at the tip accommodating portion. A spray hole 5 is arranged on the tip accommodating portion, and the flame jet converged on the tip accommodating portion is sprayed into the main combustion chamber through the spray hole 5, thereby igniting the relatively thin fuel-air mixture in the main combustion chamber. The cross section of the tip accommodating portion may be in the shape of an arc. A plurality of spray holes 5 may be uniformly arranged on the tip accommodating portion along the circumference, so that the flame jet is uniformly sprayed into the main combustion chamber from multiple directions. For example, two spray holes 5 may be symmetrically arranged on the tip accommodating portion. The spray hole 5 may be inclined downward. The straight tube portion is provided with a mounting shoulder and a ground electrode 7 for mounting the pre-combustion chamber top cover 2, and the ground electrode 7 may be arranged close to the pre-combustion chamber top cover 2, so as to promptly ignite the fuel-air mixture entering the pre-combustion chamber cavity 4. The number of ground electrodes 7 can be multiple, and multiple ground electrodes 7 are evenly arranged on the inner wall of the straight tube along the circumferential direction. The number of ground electrodes 7 corresponds to the number of ignition electrodes. In this embodiment, two ground electrodes 7 are preferably arranged. The ground electrode 7 can be arranged perpendicular to the inner wall of the straight tube, and the bending portion 9 of the ignition electrode can form a 90° bending angle. The pre-combustion chamber top cover 2 is provided with a central hole, and the central hole includes a main hole section with a larger aperture and a contraction hole section with a smaller aperture. A shoulder is formed at the connection between the main hole section and the contraction hole end, and the injector 6 is arranged in the main hole section and supported on the shoulder. The outlet of the contraction hole end can be expanded outward to guide the fuel injected by the injector 6 into the pre-combustion chamber cavity 4. The pre-combustion chamber top cover 2 is provided with at least two through grooves surrounding the central hole, and each ignition electrode passes through each through groove. An insulator 10 covering the ignition electrode is also arranged in the through groove.

[0029] It should be particularly pointed out that the various components or steps in the above-mentioned embodiments can be cross-linked, replaced, added, or deleted with each other. Therefore, the combinations formed by these reasonable arrangements and combinations should also fall within the scope of protection of the present invention, and the scope of protection of the present invention should not be limited to the embodiments.

[0030] The above are exemplary embodiments disclosed in the present invention. The order disclosed in the above embodiments of the present invention is for description only and does not represent the advantages and disadvantages of the embodiments. However, it should be noted that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope disclosed in the embodiments of the present invention (including the claims) is limited to these examples. Various changes and modifications may be made without departing from the scope defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0031] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. An active pre-combustion chamber with adjustable jet velocity, comprising a pre-combustion chamber shell (1), a pre-combustion chamber top cover (2) being arranged on the top of the pre-combustion chamber shell (1), a pre-combustion chamber cavity (4) being provided between the pre-combustion chamber top cover (2) and the pre-combustion chamber shell (1), characterized in that: A spray hole (5) is provided at the bottom of the precombustion chamber shell (1), an injector (6) connected to the precombustion chamber cavity (4) is installed on the precombustion chamber top cover (2), at least two ignition electrodes are provided in the precombustion chamber cavity (4), the ignition electrode passes through the precombustion chamber top cover (2), and a spark gap (8) is formed between one end of the ignition electrode arranged in the precombustion chamber cavity (4) and a ground electrode (7) in the precombustion chamber shell (1), and the other end of the ignition electrode extends to the upper end of the precombustion chamber top cover (2).

2. The active pre-combustion chamber with adjustable jet velocity according to claim 1, characterized in that: The portion of the ignition electrode located inside the pre-combustion chamber top cover (2) is covered with an insulator (10).

3. The active pre-combustion chamber with adjustable jet velocity according to claim 1, characterized in that: The ignition electrode comprises a central electrode (11) and a lead-out electrode (12), wherein one end of the central electrode (11) is arranged in the pre-combustion chamber cavity (4), and the other end of the central electrode (11) extends to the inside of the pre-combustion chamber top cover (2); one end of the lead-out electrode (12) is arranged in the inside of the pre-combustion chamber top cover (2) and connected to the central electrode (11), and the other end of the lead-out electrode (12) extends to the upper end of the pre-combustion chamber top cover (2).

4. The active pre-combustion chamber with adjustable jet velocity according to claim 3, characterized in that: The central electrode (11) and the lead-out electrode (12) are connected via a resistor sealing material (13).

5. The active pre-combustion chamber with adjustable jet velocity according to claim 3, characterized in that: A bent portion (9) is provided at one end of the central electrode (11) disposed in the pre-combustion chamber cavity (4), and the spark gap (8) is provided between the bent portion (9) and the ground electrode (7).

6. The active pre-combustion chamber with adjustable jet velocity according to claim 3, characterized in that: The ground electrode (7) is arranged protrudingly on a side wall inside the pre-combustion chamber housing (1).

7. The active pre-combustion chamber with adjustable jet velocity according to claim 1, characterized in that: The pre-combustion chamber top cover (2) is connected to the pre-combustion chamber shell (1) via threads.

8. The active pre-combustion chamber with adjustable jet velocity according to claim 7, characterized in that: A sealing gasket (3) is provided between the bottom of the pre-combustion chamber top cover (2) and the pre-combustion chamber shell (1).

9. The active pre-combustion chamber with adjustable jet velocity according to claim 1, characterized in that: The pre-combustion chamber cavity (4) is connected to the main combustion chamber via a spray hole (5).

10. The active pre-combustion chamber with adjustable jet velocity according to any one of claims 1 to 9, characterized in that: The ignition electrode is connected to an electronic control unit.

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