Special high-pressure sheath for natural gas engine of commercial vehicle

Abstract

A high-pressure sheath special for a natural gas engine of a commercial vehicle comprises a high-pressure connecting rod made of plastic materials, a high-pressure sheath body made of Teflon materials and a cylinder head cover sealing cover made of silicone rubber materials, the high-pressure sheath body is connected to the lower end of the high-pressure connecting rod in a sleeved mode, and the cylinder head cover sealing cover is connected to the upper end of the high-pressure connecting rod in a sleeved mode. A high-pressure spring is installed in the high-pressure connecting rod and the high-pressure sheath in the longitudinal direction, the top end of the high-pressure spring is fixed to the upper end of the high-pressure connecting rod through a high-pressure connecting bolt, and a sheath sealing ring is installed in the high-pressure sheath and surrounds the periphery of the lower end of the high-pressure spring. The cylinder head cover sealing cover is provided with a labyrinth type exhaust path so that ionized gas in the spark plug well can be exhausted under the sealed condition. The spark plug effectively reduces product surface corrosion caused by corona discharge, adopts a labyrinth exhaust route, ensures that ozone in a spark plug well can be smoothly discharged, can ensure relative sealing performance, prevents external moisture from immersing, and prevents corrosion insulation.

Description

Technical Field

[0001] The utility model relates to a special high-pressure sheath for a natural gas engine of a commercial vehicle. Background Art

[0002] In an automotive engine's ignition system, the ignition coil is the actuator that provides the ignition energy needed to ignite the air-fuel mixture within the engine cylinder. It's a specialized pulse booster based on the principle of electromagnetic induction. It switches a low voltage of 8-32V on and off at a set frequency, generating a secondary voltage of 20-45kV that then passes through the spark plug to produce an electric spark. However, the ignition coil used in natural gas engines has some structural differences from traditional ignition coils. For example, the utility model patent with publication number CN217008906 U discloses a natural gas ignition coil, including a coil head and a connecting rod portion, the coil head including a shell, a coil winding arranged in the shell, the coil winding including a primary coil, a secondary coil and an iron core, and the secondary coil surrounds the outside of the primary coil; a plug connector is provided on one side of the shell, the plug connector is connected to the input end of the primary coil, an extension interface is provided on a side of the shell perpendicular to the plug connector, and the connecting rod portion is connected to the extension interface; a connecting terminal is provided in the extension interface, an elastic component is provided on the side of the connecting terminal close to the coil winding, and an inwardly bent spring sheet is relatively provided on the base of the elastic component, an output pin is provided on the secondary coil, and the output pin is inserted between the spring sheets; a spark plug is provided on the end of the connecting rod portion away from the coil head, and a high-voltage terminal connected to the connecting terminal and the spark plug is provided in the connecting rod portion.

[0003] While this ignition coil has a simple structure and is easy to install, it doesn't address some issues caused by its high energy density. For use in natural gas engines in heavy-duty trucks, insulation between the spring and the spark plug well is essential. While the breakdown voltage of spark plugs in conventional gasoline engines ranges from 15 to 30 kV, the breakdown voltage for these in heavy-duty natural gas engines is 25 to 38 kV. Furthermore, the high-voltage sheath used in natural gas engines is over 180 mm long. Using only silicone rubber would easily bend, making installation difficult. Shortening the silicone rubber and connecting it with a plastic rod would result in poor corona resistance. Prolonged exposure to high temperature and high voltage would result in surface whitening, corrosion, and reduced voltage resistance. Most importantly, ensuring a tight seal during exhaust to prevent moisture infiltration was crucial. Summary of the Invention

[0004] The utility model aims to provide a special high-pressure jacket for commercial vehicle natural gas engines with stable structure and good exhaust effect.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a high-voltage sheath specially used for commercial vehicle natural gas engines, which is used to be installed between the high-voltage head of the ignition coil and the spark plug well, including a high-voltage connecting rod made of plastic material, a high-voltage sheath made of Teflon material and a cylinder head cover sealing cover made of silicone rubber material, the high-voltage sheath is sleeved on the lower end of the high-voltage connecting rod, the cylinder head cover sealing cover is sleeved on the upper end of the high-voltage connecting rod, a high-voltage spring is longitudinally installed in the high-voltage connecting rod and the high-voltage sheath, the top of the high-voltage spring is fixed to the upper end of the high-voltage connecting rod by a high-voltage connecting bolt, a sheath sealing ring is installed in the high-voltage sheath, the sheath sealing ring surrounds the lower end of the high-voltage spring, and the cylinder head cover sealing cover is provided with a labyrinth exhaust route to discharge the ionized gas in the spark plug well under sealed conditions.

[0006] As a further improvement, the upper end of the high-voltage sheath forms an interconnection end, and the diameter of the lower portion of the high-voltage connecting rod is reduced so as to be integrally inserted into the interior of the interconnection end.

[0007] As a further improvement, the cylinder head cover sealing cover extends downward and wraps around the outside of the interconnected end of the high-voltage connecting rod and the high-voltage sheath.

[0008] As a further improvement, the cylinder head cover sealing cover includes an end cover, multiple concentric sealing rings formed below the end cover, and multiple concentric sealing rings formed on the upper surface of the end cover. A seal is formed between the concentric sealing rings and the spark plug well, and a seal is formed between the concentric sealing rings and the high-voltage head of the ignition coil.

[0009] As a further improvement, each of the sealing rings is provided with an overflow hole, and the overflow hole is configured to drive the ionized gas in the spark plug well to overflow layer by layer to the lower surface of the end cover.

[0010] As a further improvement, the intervals between adjacent overflow holes are greater than 100%.

[0011] As a further improvement, the end cover is provided with an air guide hole, and the air guide hole is configured to drive the ionized gas on the lower surface of the end cover to be discharged into the sealing ring.

[0012] As a further improvement, the concentric sealing ring is provided with an exhaust hole, and the exhaust hole is configured to discharge the ionized gas in the sealing ring.

[0013] As a further improvement, the exhaust hole extends outward along the upper surface of the end cover.

[0014] As a further improvement, a gap is reserved between the lower end of the high-voltage sheath and the lower end of the sheath sealing ring.

[0015] Due to the adoption of the above technical solution, the utility model has an outer (fully covered) silicone rubber and a built-in supporting plastic connecting rod. The outer silicone rubber can effectively reduce the corona corrosion resistance, and the plastic connecting rod plays a supporting role in the overall strength of the sheath, effectively reducing the surface corrosion of the product caused by corona discharge, and can be used for a long time in a high temperature environment of 220°C; in addition, a labyrinth exhaust route is adopted to ensure that ozone in the spark plug well can be discharged smoothly and to ensure relative sealing, thereby preventing external moisture from penetrating and preventing corrosion of insulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attachment Figure 1 This is a cross-sectional view of a high-pressure jacket dedicated to a natural gas engine for commercial vehicles according to the present utility model;

[0017] Attachment Figure 2 This is an exploded view of a high-pressure jacket specifically designed for a commercial vehicle natural gas engine according to the present utility model;

[0018] Attachment Figure 3 The working principle of the high-pressure sheath for commercial vehicle natural gas engine according to the utility model is shown in FIG. Figure 1 ;

[0019] Attachment Figure 4 The working principle of the high-pressure sheath for commercial vehicle natural gas engine according to the utility model is shown in FIG. Figure 2 ;

[0020] Attachment Figure 5 This is a partially enlarged view of the high-pressure sheath dedicated to the natural gas engine of a commercial vehicle according to the utility model. DETAILED DESCRIPTION

[0021] Hereinafter, the terms used in the specification will be briefly described, and the embodiments will be described in detail. All terms used herein, including descriptive terms or technical terms, should be interpreted as having meanings understood by those of ordinary skill in the art. However, these terms may have different meanings depending on the intention of those of ordinary skill in the art, precedents, or the emergence of new technologies.

[0022] In addition, some terms may be selected by the applicant, and in this case, the meaning of the selected terms will be described in detail in the detailed description of the embodiment. Therefore, the terms used in this article must be defined based on the meaning of the terms together with the description in the entire specification. In addition, when a component "includes" or "contains" an element, unless there is a specific description to the contrary, the component may also include other elements without excluding other elements. In the following description, terms such as "component" and "module" indicate a unit for processing at least one function or operation, wherein the unit and module can be implemented as hardware or software or by combining hardware and software.

[0023] The embodiments will now be described more fully with reference to the accompanying drawings. However, the embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the embodiments to those of ordinary skill in the art. In the following description, well-known functions or structures are not described in detail because they would obscure the embodiments with unnecessary detail, and throughout the specification, the same reference numerals in the drawings represent the same or similar elements.

[0024] Attachment Figure 1 : is a cross-sectional view of a high-pressure jacket dedicated to a commercial vehicle natural gas engine according to the present utility model; Figure 2 This is an exploded view of a high-voltage jacket for commercial vehicle natural gas engines according to the present invention. The high-voltage jacket for commercial vehicle natural gas engines in this embodiment is used to be installed between the high-voltage head of the ignition coil and the spark plug well. It includes a high-voltage connecting rod 1 made of plastic material, a high-voltage jacket 2 made of Teflon material, and a cylinder head cover sealing cover 3 made of silicone rubber material. The high-voltage jacket 2 is sleeved on the lower end of the high-voltage connecting rod 1, and the cylinder head cover sealing cover 3 is sleeved on the upper end of the high-voltage connecting rod 1. A high-voltage spring 4 is installed longitudinally inside the high-voltage connecting rod 1 and the high-voltage jacket 2. The top of the high-voltage spring 4 is fixed to the upper end of the high-voltage connecting rod 1 through a high-voltage connecting bolt 5. A sheath sealing ring 6 is installed in the high-voltage sheath 2. The sheath sealing ring 6 surrounds the lower end of the high-voltage spring 4. Since corona discharge can cause air ionization to produce ozone and nitrogen oxides (N0, N02) that corrode insulation, a labyrinth exhaust route is provided on the cylinder head cover sealing cover 3 to discharge the ionized gas in the spark plug well under sealed conditions, ensuring that the ozone in the spark plug well can be discharged smoothly and can ensure relative sealing to prevent external moisture from infiltrating.

[0025] The high-voltage sheath 2 is located close to the spark plug components, so it must be made of a high-temperature-resistant Teflon material that can withstand long-term use in high-temperature environments of 240°C. The upper end of the high-voltage sheath 2 forms an interconnection end 21, and the lower portion of the high-voltage connecting rod 1 is reduced in diameter to allow its entirety to be inserted into the interior of the interconnection end 21.

[0026] The cylinder head cover sealing cap 3 extends downward and wraps around the exterior of the interconnecting end 21 of the high-voltage connecting rod 1 and the high-voltage jacket 2. This structure, with a fully silicone rubber exterior and an internal supporting plastic connecting rod, effectively reduces corona corrosion resistance while the plastic connecting rod supports the overall strength of the jacket, effectively reducing surface corrosion caused by corona discharge.

[0027] Attachment Figure 3 The working principle of the high-pressure sheath for commercial vehicle natural gas engine according to the utility model is shown in FIG. Figure 1 ; Attachment Figure 4The working principle of the high-pressure sheath for commercial vehicle natural gas engine according to the utility model is shown in FIG. Figure 2 The cylinder head cover seal 3 includes an end cap 31, multiple concentric sealing rings 32 formed below the end cap 31, and multiple concentric sealing rings 33 formed on the upper surface of the end cap 31. When the high-voltage jacket specifically designed for commercial vehicle natural gas engines is fully inserted into the spark plug well shown in the figure, a seal is formed between the concentric sealing rings 32 and the spark plug well, and a seal is formed between the concentric sealing rings 33 and the high-voltage head of the ignition coil (not shown, located above the cylinder head cover seal 3).

[0028] Each sealing ring 32 is provided with an overflow hole 34, and the adjacent overflow holes 34 are spaced 180 degrees apart. The overflow holes 34 are configured to drive the ionized gas in the spark plug well to overflow layer by layer to the lower surface of the end cover 31. The end cover 31 is provided with a gas guide hole 35, which is configured to drive the ionized gas on the lower surface of the end cover 31 to be discharged into the sealing ring 33. The gas guide hole 35 is located near the center of the end cover 31 and is an internal channel inclined outward. The concentric sealing ring 33 is provided with an exhaust hole 36, which extends outward along the upper surface of the end cover 31. The exhaust hole 36 is configured to discharge the ionized gas in the sealing ring 33. When ionized gas is generated in the spark plug well due to the high voltage used for spark plug ignition transmitted by the high-pressure spring, the high-temperature ionized gas will move upward, and thus will be discharged according to the attached Figure 3 As shown by the arrows in the figure, the water overflows layer by layer to the lower surface of the end cover 31, and then is guided into the sealing ring 33 through the air guide hole 35, and finally is discharged to the outside along the upper surface of the end cover 31 through the exhaust hole 36. The entire exhaust process ensures sealing, and external water vapor cannot enter in the reverse direction.

[0029] Attachment Figure 5 This is a partial enlarged view of the high-pressure jacket for commercial vehicle natural gas engines according to the present invention. The jacket seal is tightly fitted to the spark plug, so a gap D is provided between the lower end of the high-pressure jacket 2 and the lower end of the jacket seal 6 to ensure sufficient expansion margin for extrusion deformation when mated with the spark plug. Because the spark plug ceramic body (where it seals with the jacket) can reach a maximum temperature of 200°C in natural gas engine applications, the seal is made of a special silicone rubber material that can withstand long-term use in high-temperature environments of 220°C.

[0030] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects within each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope defined by the appended claims.

Claims

1. A high-voltage jacket for commercial vehicle natural gas engines, used to be installed between the high-voltage head of an ignition coil and the spark plug well, characterized by: The invention comprises a high-voltage connecting rod (1) made of plastic material, a high-voltage jacket (2) made of Teflon material and a cylinder head cover sealing cover (3) made of silicone rubber material, wherein the high-voltage jacket (2) is sleeved on the lower end of the high-voltage connecting rod (1), and the cylinder head cover sealing cover (3) is sleeved on the upper end of the high-voltage connecting rod (1). A high-voltage spring (4) is longitudinally installed in the high-voltage connecting rod (1) and the high-voltage jacket (2), and the top end of the high-voltage spring (4) is fixed to the upper end of the high-voltage connecting rod (1) through a high-voltage connecting bolt (5). A jacket sealing ring (6) is installed in the high-voltage jacket (2), and the jacket sealing ring (6) surrounds the lower end of the high-voltage spring (4). A labyrinth exhaust route is arranged on the cylinder head cover sealing cover (3) to discharge the ionized gas in the spark plug well under a sealed condition.

2. The high-pressure sheath for commercial vehicle natural gas engines according to claim 1, characterized in that: The upper end of the high-voltage sheath (2) forms an interconnection end (21), and the diameter of the lower portion of the high-voltage connecting rod (1) is reduced so as to be integrally inserted into the interior of the interconnection end (21).

3. The high-pressure sheath for commercial vehicle natural gas engines according to claim 2, characterized in that: The cylinder head cover sealing cover (3) extends downward and wraps around the outside of the interconnected end (21) of the high-voltage connecting rod (1) and the high-voltage sheath (2).

4. The high-pressure sheath for commercial vehicle natural gas engines according to claim 3, characterized in that: The cylinder head cover sealing cover (3) comprises an end cover (31), a plurality of concentric sealing rings (32) formed below the end cover (31), and a plurality of concentric sealing rings (33) formed on the upper surface of the end cover (31), wherein a seal is formed between the concentric sealing rings (32) and the spark plug well, and a seal is formed between the concentric sealing rings (33) and the high-voltage head of the ignition coil.

5. The high-pressure sheath dedicated to commercial vehicle natural gas engines according to claim 4, characterized in that: Each of the sealing rings (32) is provided with an overflow hole (34), and the overflow hole (34) is configured to drive the ionized gas in the spark plug well to overflow layer by layer to the lower surface of the end cover (31).

6. The high-pressure sheath for commercial vehicle natural gas engines according to claim 5, characterized in that: Adjacent overflow holes (34) are spaced 180 degrees apart.

7. The high-pressure jacket for commercial vehicle natural gas engines according to claim 4, characterized in that: The end cover (31) is provided with an air guide hole (35), and the air guide hole (35) is configured to drive the ionized gas on the lower surface of the end cover (31) to be discharged into the sealing ring (33).

8. The high-pressure jacket for commercial vehicle natural gas engines according to claim 4, characterized in that: The concentric sealing ring (33) is provided with an exhaust hole (36), and the exhaust hole (36) is configured to discharge ionized gas in the sealing ring (33).

9. The high-pressure sheath dedicated to commercial vehicle natural gas engines according to claim 8, characterized in that: The exhaust hole (36) extends outward along the upper surface of the end cover (31).

10. The high-pressure jacket dedicated to commercial vehicle natural gas engines according to claim 1, characterized in that: A gap is reserved between the lower end of the high-voltage sheath (2) and the lower end of the sheath sealing ring (6).

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