Spark plug, combustion system and engine

Abstract

The utility model provides a spark plug, a combustion system and an engine. The spark plug comprises a central electrode, a wind shield covering the outer side of the central electrode, and a side electrode. The side electrode is arranged on the inner wall of the wind shield, and an ignition gap is formed between the side electrode and the central electrode; a ventilation hole is formed in the wind shield and penetrates through the wind shield along the wall thickness of the wind shield, and an inner port of the ventilation hole is opposite to the central electrode; the preset plane is perpendicular to the central axis of the central electrode; the vent hole corresponds to one radial line of the central electrode; the projections of the corresponding radial lines on the preset plane intersect with the inner ends and the outer ends of the projections of the ventilation holes on the preset plane; the projection of the hole center line of the ventilation hole on the preset plane and the projection of the corresponding radial line on the preset plane intersect and form an acute included angle. The spark plug can avoid or reduce the fire phenomenon of the spark plug.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of spark plug, specifically, a spark plug, combustion system and engine. BACKGROUND

[0002] Natural gas is often used as an alternative fuel for internal combustion engines, which has the advantages of good economy, no soot emission and low carbon dioxide emission. However, natural gas has low cetane number, poor ignition performance, high self-ignition temperature and slow combustion speed; therefore, the combustion system of the engine adopts a combination of tumble flow port and canopy cylinder head to improve the tumble ratio, so that fresh mixture can fully sweep away the residual exhaust gas around the spark plug, making the mixture easy to ignite.

[0003] Under high speed working conditions, due to the existence of the canopy structure, strong tumble flow can still be maintained near the compression top dead center, and the spark plug is located near the outer edge of the tumble flow, so the flow velocity near the spark plug is high, and the spark plug ignition forms a kernel that is easily blown out, causing misfire. SUMMARY

[0004] The main purpose of the utility model is to provide a spark plug, combustion system and engine to avoid or reduce the misfire phenomenon of the spark plug.

[0005] In order to achieve the above purpose, according to one aspect of the utility model, a spark plug is provided, which comprises: a center electrode, a windscreen covering the outside of the center electrode, and a side electrode; the side electrode is arranged on the inner wall of the windscreen and forms an ignition gap with the center electrode; the windscreen is provided with a ventilation hole, the ventilation hole penetrates the windscreen along the wall thickness of the windscreen, and the inner end of the ventilation hole is arranged opposite to the center electrode; the preset plane is perpendicular to the center axis of the center electrode; the ventilation hole corresponds to a radial line of the center electrode; the projection of the corresponding radial line on the preset plane intersects the inner end and the outer end of the projection of the ventilation hole on the preset plane; the projection of the hole center line of the ventilation hole on the preset plane intersects the projection of the corresponding radial line on the preset plane and is arranged at an acute angle.

[0006] Further, the angle between the projection of the hole center line of the ventilation hole on the preset plane and the projection of the corresponding radial line on the preset plane is in the range of 5 degrees to 15 degrees.

[0007] Further, along the axial direction of the center electrode, the outer end of the ventilation hole is located on the side away from the side electrode of the inner end.

[0008] Further, the angle between the hole center line of the ventilation hole and the preset plane is in the range of greater than or equal to 30 degrees and less than 90 degrees.

[0009] Furthermore, along the axial direction of the central electrode, a distance between an inner end of the ventilation hole and an end surface of the central electrode facing the side electrode is H, and a value range of H is greater than or equal to 2 mm and less than or equal to 5 mm.

[0010] Furthermore, along the axial direction of the central electrode, the intersection of the centerline of the ventilation hole and the central axis of the wind shield is located on a side of the end surface of the central electrode facing the side electrode and away from the side electrode.

[0011] Further, along the axial direction of the central electrode, the inner end of the ventilation hole is located on a side of the end surface of the central electrode facing the side electrode and away from the side electrode.

[0012] Furthermore, a plurality of ventilation holes are arranged on the windshield at intervals along its circumference.

[0013] Furthermore, the side electrode has a connecting end and a free end, the connecting end of the side electrode is fixedly connected to the inner wall of the windshield; along the axial direction of the central electrode, the free end of the side electrode is located on the side of the connecting end away from the ventilation hole.

[0014] Furthermore, there are multiple side electrodes, and the multiple side electrodes are distributed along the circumference of the windshield and arranged around the central electrode.

[0015] Furthermore, the side electrodes and the windshield are an integrally formed structure.

[0016] According to another aspect of the present invention, a combustion system is provided, which includes the above-mentioned spark plug.

[0017] According to another aspect of the present invention, an engine is provided, which includes the above-mentioned combustion system.

[0018] By applying the technical solution of the present utility model, the spark plug includes a center electrode, a windshield and a side electrode; the windshield is arranged on the outside of the center electrode; the side electrode is arranged on the inner wall of the windshield, and an ignition gap is formed between the side electrode and the center electrode; that is, the ignition gap is located inside the windshield.

[0019] A ventilation hole is provided on the windshield, and the ventilation hole penetrates the windshield along the wall thickness of the windshield; the two ends of the ventilation hole are an inner port and an outer port respectively, the inner port of the ventilation hole is located on the inner wall surface of the windshield, and the outer port of the ventilation hole is located on the outer wall surface of the windshield; the inner port of the ventilation hole is arranged opposite to the center electrode.

[0020] The center electrode has a plurality of radial lines along the circumference thereof; the vent hole corresponds to one radial line of the center electrode; the projection of the corresponding radial line on the preset plane intersects both the inner end and the outer end of the projection of the vent hole on the preset plane; the projection of the hole center line of the vent hole on the preset plane intersects the projection of the corresponding radial line on the preset plane, and the projection of the hole center line of the vent hole on the preset plane and the projection of the corresponding radial line on the preset plane are arranged at an acute angle.

[0021] The spark plug of the present application can surround the ignition gap with the wind shield, and the arrangement of the vent hole of the present application makes the high-speed airflow in the cylinder not directly blow on the ignition gap, so that the misfire phenomenon of the spark plug can be avoided or reduced.

[0022] In addition, the arrangement of the vent hole of the present application has a certain flow guiding effect, and the plurality of vent holes can form vortex flow in the wind shield; in this way, the flow velocity between the center electrode and the side electrode can be reduced, that is, the flow velocity at the ignition gap is reduced, that is, the flow velocity near the spark electrode is reduced, thereby avoiding or reducing the misfire phenomenon of the spark plug. Moreover, the airflow with low flow velocity is used for scavenging, the turbulent kinetic energy at the electrode is improved, thereby improving the stability of the spark plug ignition. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the present application. The use of the same reference numerals in different drawings indicates similar or identical components.

[0024] Figure 1 An external structure schematic view of the spark plug according to the present application is shown;

[0025] Figure 2 A transverse sectional view of the spark plug in Figure 1 is shown;

[0026] Figure 3 A partial perspective view of the spark plug in Figure 1 is shown;

[0027] Figure 4 A partial perspective view of the spark plug in Figure 1 is shown;

[0028] Figure 5 A longitudinal sectional view of the spark plug in Figure 1 is shown;

[0029] Figure 6 A structure schematic view of the combustion system according to the present application is shown.

[0030] In the above drawings, the following reference numerals are used:

[0031] 100, spark plug; 10, center electrode; 11, second projection line; 20, wind shield; 21, vent hole; 211, hole center line; 212, first projection line; 30, side electrode; 40, ignition gap; 50, preset plane;

[0032] 91, intake passage; 911, intake valve; 92, exhaust passage; 921, exhaust valve; 93, piston; 94, cylinder head; 941, tumble intake passage; 95, cylinder liner. DETAILED DESCRIPTION

[0033] It should be noted that the embodiments and features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0034] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0035] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of a feature, step, operation, device, component and / or combination thereof.

[0036] The present application provides a spark plug 100, please refer to Figures 1 to 5 The spark plug 100 comprises a center electrode 10, a wind shield 20 and a side electrode 30; the wind shield 20 is covered on the outside of the center electrode 10; the side electrode 30 is arranged on the inner wall of the wind shield 20, and the ignition gap 40 is formed between the side electrode 30 and the center electrode 10; that is, the ignition gap 40 is located in the wind shield 20.

[0037] The wind shield 20 is provided with a vent hole 21, and the vent hole 21 penetrates the wind shield 20 along the wall thickness of the wind shield 20; the two ports of the vent hole 21 are respectively an inner port and an outer port, the inner port of the vent hole 21 is located on the inner wall surface of the wind shield 20, and the outer port of the vent hole 21 is located on the outer wall surface of the wind shield 20; the inner port of the vent hole 21 is arranged opposite to the center electrode 10.

[0038] The center electrode 10 has a plurality of radial lines along its circumference; the preset plane 50 is perpendicular to the center axis of the center electrode 10; each radial line of the center electrode 10 is parallel to the preset plane 50.

[0039] The vent hole 21 corresponds to a radial line of the central electrode 10; a projection of the corresponding radial line on the preset plane 50 intersects both an inner end and an outer end of a projection of the vent hole 21 on the preset plane 50; a projection of a hole center line of the vent hole 21 on the preset plane 50 intersects the projection of the corresponding radial line on the preset plane 50, and the projection of the hole center line of the vent hole 21 on the preset plane 50 forms an acute angle with the projection of the corresponding radial line on the preset plane 50.

[0040] As shown in Figure 2 , a first projection line 212 is a projection of a hole center line of the vent hole 21 on the preset plane 50, and a second projection line 11 is a projection of a corresponding radial line of the vent hole 21 on the preset plane 50; an angle a is an angle between the first projection line 212 and the second projection line 11.

[0041] Specifically, along the axial direction of the central electrode 10, the free end of the side electrode 30 and the free end of the central electrode 10 have a gap.

[0042] Optionally, along the radial direction of the central electrode 10, the free end of the side electrode 30 and the free end of the central electrode 10 have a gap.

[0043] Specifically, a cross section of the central electrode 10 perpendicular to the axial direction thereof is circular.

[0044] Optionally, a cross section of the wind shield 20 perpendicular to the axial direction thereof is circular.

[0045] In the present application, optionally, an angle between a projection of a hole center line of the vent hole 21 on the preset plane 50 and a projection of a corresponding radial line on the preset plane 50 is in a range of 5 degrees to 15 degrees. That is, the angle a is in a range of 5 degrees to 15 degrees.

[0046] In the present application, optionally, along the axial direction of the central electrode 10, an outer port of the vent hole 21 is located on a side of an inner port away from the side electrode 30, so that the hole center line of the vent hole 21 and the preset plane 50 form an acute angle. As shown in Figure 4 , the outer port of the vent hole 21 is located on an upper side of the inner port. Figure 4 The hole center line 211 in

[0047] Optionally, an angle between the hole center line of the vent hole 21 and the preset plane 50 is in a range of greater than or equal to 30 degrees and less than 90 degrees.

[0048] Specifically, based on the setting form of the vent hole 21, a spiral airflow is formed in the wind shield 20.

[0049] In the present application, optionally, along the axial direction of the center electrode 10, the spacing between the inner port of the ventilation hole 21 and the end surface of the center electrode 10 facing the side electrode 30 is H, and the value of H is greater than or equal to 2mm and less than or equal to 5mm.

[0050] In the present application, optionally, along the axial direction of the center electrode 10, the intersection of the center line of the ventilation hole 21 and the central axis of the wind shield 20 is located on the side of the end surface of the center electrode 10 facing the side electrode 30 away from the side electrode 30. As shown in Figure 4 , the intersection of the center line of the ventilation hole 21 and the central axis of the wind shield 20 is located on the upper side of the end surface of the center electrode 10 facing the side electrode 30.

[0051] In the present application, optionally, along the axial direction of the center electrode 10, the inner port of the ventilation hole 21 is located on the side of the end surface of the center electrode 10 facing the side electrode 30 away from the side electrode 30. As shown in Figure 5 , the inner port of the ventilation hole 21 is located on the upper side of the end surface of the center electrode 10 facing the side electrode 30.

[0052] In the present application, the wind shield 20 is provided with a plurality of ventilation holes 21 spaced apart along the circumferential direction thereof, and each ventilation hole 21 corresponds to one of the radial lines of the center electrode 10.

[0053] Optionally, the number of ventilation holes 21 is greater than or equal to 4.

[0054] In the present application, the side electrode 30 has a connecting end and a free end; the connecting end of the side electrode 30 is fixedly connected to the inner wall of the wind shield 20; along the axial direction of the center electrode 10, the free end of the side electrode 30 is located on the side of the connecting end away from the ventilation hole 21, so that the distribution direction of the connecting end and the free end of the side electrode 30 is arranged at an acute angle with the preset plane 50. As shown in Figure 5 , the free end of the side electrode 30 is located on the lower side of the connecting end.

[0055] Optionally, the angle between the distribution direction of the connecting end and the free end of the side electrode 30 and the preset plane 50 is greater than or equal to 0 degrees and less than or equal to 30 degrees.

[0056] In the present application, optionally, the side electrode 30 and the wind shield 20 are integrally formed, that is, the side electrode 30 is integrated on the wind shield 20.

[0057] In the present application, optionally, along the axial direction of the wind shield 20, the side electrode 30 is located at the end of the free end of the wind shield 20. As shown in Figure 5 , the side electrode 30 is located at the bottom end of the wind shield 20.

[0058] In the present application, the side electrodes 30 are multiple, the multiple side electrodes 30 are distributed along the circumference of the windscreen 20, and the multiple side electrodes 30 are arranged around the center electrode 10.

[0059] Specifically, the free ends of any two side electrodes 30 are spaced apart.

[0060] The utility model also provides a kind of combustion system, as shown in Figures 1 to 6 It includes the spark plug 100 described above.

[0061] Specifically, the combustion system is a natural gas combustion system.

[0062] Specifically, the combustion system further includes an intake passage 91, an exhaust passage 92, an intake valve 911, an exhaust valve 921, a piston 93, a cylinder head 94, a cylinder liner 95;The piston 93 is arranged in the cylinder liner 95;The intake valve 911 is arranged at one end of the intake passage 91 to open or close the intake passage 91;The exhaust valve 921 is arranged at one end of the exhaust passage 92 to open or close the exhaust passage 92. Among them, the piston 93, the cylinder head 94 and the cylinder liner 95 constitute the main combustion chamber.

[0063] Specifically, the cylinder head 94 is in the form of a canopy;The cylinder head 94 is provided with a tumble intake passage 941 to make the flow organization form in the cylinder tumble, that is, the mixture entering the main combustion chamber forms a tumble rotating around the central axis of the cylinder liner 95.

[0064] Specifically, the end of the intake passage 91 provided with the intake valve 911 is communicated with the tumble intake passage 941;The end of the exhaust passage 92 provided with the exhaust valve 921 is communicated with the tumble intake passage 941.

[0065] Specifically, the spark plug 100 is arranged in the tumble intake passage 941;The tumble direction near the spark plug 100 flows from the intake side to the exhaust side, and the tumble direction is as shown in Figure 6 .

[0066] At high speed and heavy load, the flow rate near the spark plug is high, which is easy to cause misfire. For the canopy structure combustion chamber, the tumble maintaining effect is strong, and near the top dead center of compression, the airflow near the spark plug flows from the intake side to the exhaust side, and under high speed working condition, the flow rate is high, and the spark plug ignition forms a kernel which is easily blown out, causing misfire. The spark plug 100 of the present application can surround the ignition gap 40 with the windscreen 20, and the arrangement of the ventilation hole 21 makes the high-speed airflow in the cylinder unable to directly blow the ignition gap 40, so that the misfire phenomenon of the spark plug 100 can be avoided or reduced.

[0067] In addition, the ventilation hole 21 of the application has a certain flow guiding effect, and the plurality of ventilation holes 21 can form a vortex in the wind shield 20; in this way, the flow rate at the position between the center electrode 10 and the side electrode 30 can be reduced, that is, the flow rate at the ignition gap 40 can be reduced, and the flow rate near the spark electrode can be reduced, thereby avoiding or reducing the misfire phenomenon of the spark plug 100. Moreover, the scavenging is performed by using the airflow with a low flow rate, the turbulent kinetic energy at the electrode is improved, and the stability of the ignition of the spark plug 100 is improved.

[0068] In addition, the arrangement form of the ventilation hole 21 of the application can also improve the scavenging condition near the spark plug 100, thereby reducing the residual exhaust gas near the spark plug 100 and improving the scavenging efficiency.

[0069] The spark plug 100 of the application can be applied to a strong tumble combustion system.

[0070] The utility model further provides an engine which comprises the combustion system.

[0071] Specifically, the engine is a natural gas engine.

[0072] From the above description, it can be seen that the above-mentioned embodiments of the application achieve the following technical effects:

[0073] The utility model provides a spark plug 100, spark plug 100 includes center electrode 10, wind shield 20 and side electrode 30, wind shield 20 covers the outside of center electrode 10, side electrode 30 sets up on the inner wall of wind shield 20, and side electrode 30 and center electrode 10 form ignition gap 40 between, that is, ignition gap 40 is located in wind shield 20.

[0074] Wind shield 20 is provided with ventilation hole 21, and ventilation hole 21 penetrates wind shield 20 along the wall thickness of wind shield 20, the two ports of ventilation hole 21 are respectively inner port and outer port, and the inner port of ventilation hole 21 is located on the inner wall surface of wind shield 20, and the outer port of ventilation hole 21 is located on the outer wall surface of wind shield 20, and the inner port of ventilation hole 21 is oppositely arranged with center electrode 10.

[0075] Center electrode 10 has a plurality of radial lines along the circumference thereof, and the ventilation hole 21 corresponds to one of the radial lines of the center electrode 10; the projection of the corresponding radial line on the preset plane 50 intersects the inner end and the outer end of the projection of the ventilation hole 21 on the preset plane 50; the projection of the hole center line of the ventilation hole 21 on the preset plane 50 intersects the projection of the corresponding radial line on the preset plane 50, and the projection of the hole center line of the ventilation hole 21 on the preset plane 50 and the projection of the corresponding radial line on the preset plane 50 are arranged at an acute angle.

[0076] The spark plug 100 of the present application can use the wind shield 20 to surround the ignition gap 40, and the arrangement of the vent holes 21 of the present application makes the high-speed airflow in the cylinder not directly blow on the ignition gap 40, so that the misfire phenomenon of the spark plug 100 can be avoided or reduced.

[0077] In addition, the arrangement of the vent holes 21 of the present application has a certain flow guiding effect, and the plurality of vent holes 21 can form a vortex flow in the wind shield 20; in this way, the flow velocity at the position between the center electrode 10 and the side electrode 30, i.e. the flow velocity at the ignition gap 40, i.e. the flow velocity near the spark electrode, can be reduced, and the misfire phenomenon of the spark plug 100 can be avoided or reduced. Moreover, the lower flow velocity airflow is used for scavenging, the turbulent kinetic energy at the electrode is improved, and the stability of the spark plug 100 ignition is improved.

[0078] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0079] For ease of description, spatial relative terms such as "over", "above", "upper surface", "upper", etc. can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device as described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0080] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A spark plug characterized by, The spark plug comprises a center electrode (10), a wind shield (20) covering the center electrode (10), and a side electrode (30); the side electrode (30) is arranged on the inner wall of the wind shield (20) and forms an ignition gap (40) with the center electrode (10); The wind shield (20) is provided with a ventilation hole (21) penetrating the wind shield (20) along the wall thickness of the wind shield (20), and the inner end of the ventilation hole (21) is arranged opposite to the center electrode (10); A preset plane (50) is perpendicular to the central axis of the center electrode (10); the ventilation hole (21) corresponds to a radial line of the center electrode (10); the projection of the corresponding radial line on the preset plane (50) intersects the inner end and the outer end of the projection of the ventilation hole (21) on the preset plane (50); The projection of the center line of the ventilation hole (21) on the preset plane (50) intersects the projection of the corresponding radial line on the preset plane (50) and forms an acute angle.

2. The spark plug of claim 1, wherein The angle between the projection of the center line of the ventilation hole (21) on the preset plane (50) and the projection of the corresponding radial line on the preset plane (50) is 5-15 degrees.

3. The spark plug of claim 1, wherein Along the axial direction of the center electrode (10), the outer end of the ventilation hole (21) is located on the side away from the side electrode (30) of the inner end.

4. The spark plug of claim 3, wherein The angle between the center line of the ventilation hole (21) and the preset plane (50) is greater than or equal to 30 degrees and less than 90 degrees.

5. The spark plug of claim 1, wherein Along the axial direction of the center electrode (10), The distance between the inner end of the ventilation hole (21) and the end face of the center electrode (10) facing the side electrode (30) is H, and H is greater than or equal to 2 mm and less than or equal to 5 mm; and / or The intersection point of the center line of the ventilation hole (21) and the central axis of the wind shield (20) is located on the side of the end face of the center electrode (10) facing the side electrode (30) away from the side electrode (30); and / or The inner end of the ventilation hole (21) is located on the side of the end face of the center electrode (10) facing the side electrode (30) away from the side electrode (30).

6. The spark plug of any one of claims 1 to 5, wherein, A plurality of ventilation holes (21) are arranged on the wind shield (20) at intervals in the circumferential direction.

7. The spark plug of claim 1, wherein The side electrode (30) has a connecting end and a free end, and the connecting end of the side electrode (30) is fixedly connected to the inner wall of the wind shield (20); along the axial direction of the center electrode (10), the free end of the side electrode (30) is located on the side away from the ventilation hole (21) of the connecting end.

8. The spark plug of claim 1, wherein The side electrode (30) is a plurality of side electrodes (30) distributed in the circumferential direction of the wind shield (20) and arranged around the center electrode (10); and / or the side electrode (30) is an integral structure with the wind shield (20).

9. A combustion system characterized by, The spark plug of any one of claims 1 to 8.

10. An engine characterized by, The combustion system of claim 9.

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