Intake pipe for high efficiency natural gas engine

Abstract

The application discloses an air inlet connector of a high-efficiency natural gas engine, which comprises a mounting part, a flow guide part and an air inlet part, the two ends of the flow guide part are connected with the right end of the mounting part and the air inlet part respectively, the rear side of the mounting part is provided with an opening, and the left end of the mounting part is a pointed part. The low-resistance air inlet system is adopted to improve the mixing uniformity of each cylinder, increase the air inlet volume ratio, and make the volume of the air inlet pipe and the air inlet connector as large as possible in limited space.

Description

Technical Field

[0001] This invention relates to the field of engine intake system technology, and in particular to an intake manifold for a high-efficiency natural gas engine. Background Technology

[0002] With increasingly stringent engine emission regulations and rising customer demands for driving comfort, higher standards are being set for engine emission performance and NVH (Noise, Vibration, and Harshness) performance. The consistency of intake volume and swirl ratio across cylinders directly affects the uniformity of cylinder operation, which in turn is closely related to the emissions of each cylinder and the overall NVH performance of the engine. Therefore, the design of the intake manifold structure is crucial to ensuring uniform cylinder operation. Intake methods can be categorized into end-face intake and intermediate intake. End-face intake offers excellent intake consistency but poor compatibility, while intermediate intake typically has poor consistency but excellent compatibility, meeting the needs of multiple vehicle models, especially off-road engines, which primarily utilize intermediate intake.

[0003] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0004] The (main) objective of this invention is to propose an intake manifold for a high-efficiency natural gas engine that employs a low-resistance intake system, improves the mixing uniformity of each cylinder, increases the intake volume ratio, and maximizes the volume of the intake manifold and intake connector within a limited space.

[0005] Therefore, this invention proposes an intake manifold for a high-efficiency natural gas engine.

[0006] Preferably, the present invention may also have the following technical features:

[0007] An intake pipe for a high-efficiency natural gas engine includes an installation part, a guide part, and an intake part. The two ends of the guide part are respectively connected to the right end of the installation part and the intake part. The installation part has an opening on its rear side and a pointed end on its left side.

[0008] Furthermore, the angle between the left side and the front side of the mounting part is an acute angle.

[0009] Furthermore, the left and front sides of the mounting portion are rounded.

[0010] Furthermore, the included angle between the left side and the front side of the mounting part is 50-70°.

[0011] Furthermore, the guide section is an arc-shaped tube with a lower left side and a higher right side, with the left port facing the left side and the right port facing the rear side.

[0012] Furthermore, the air intake is an L-shaped pipe structure, with its front end and the guide section transitioning to a circular arc, and its rear port facing to the left and having a flange surface.

[0013] Furthermore, the interior of the mounting section forms a flow guide cavity, and the opening connecting it to the air intake pipe is a square opening. Several bolt connection holes are provided on the outer side of the square opening. The use of a square opening can increase the flow rate.

[0014] Furthermore, a guide plate is provided inside the flow guiding cavity of the mounting part, and the guide plate is arranged along the front and rear direction of the mounting part.

[0015] Furthermore, the guide plate is installed on the lower middle part of the flow guide cavity and is arranged on the bolt connection hole rib located in the middle.

[0016] Furthermore, the height of the guide plate is less than the height of the flow cavity, and the length of the guide plate is less than the width of the flow cavity.

[0017] The beneficial effects of this invention compared to existing technologies include: by setting the pointed end, the intake air distribution of cylinders 1 and 2 of the engine (cylinders 1 and 2 are located at the end near the mounting part) can be controlled to be uniform, and in conjunction with the intake pipe, uniform distribution of fuel mixture in each cylinder is achieved. The intake pipe gradually changes from a round pipe to a flat pipe, with a smooth interior, and the volume is not reduced due to the concave design of the intake pipe caused by the relocation. At the same time, the intake pipe adopts a manifold-less design, and the inner cavity of the intake pipe adopts a through-groove design without baffles, thereby allowing for a larger intake pipe and intake pipe, increasing the intake volume. The closer the volume ratio is to 1.1, the better the improvement in engine combustion efficiency and economy. This embodiment can increase the volume ratio from 0.91 to 1.05. By using the guide plate in conjunction with the pointed ends of the intake pipe and intake pipe, the water-air distribution of cylinders 1 and 2 of the engine can be effectively improved, preventing misfire in cylinder 1. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the first orientation of the present invention.

[0019] Figure 2 This is a schematic diagram of the second orientation of the present invention.

[0020] Figure 3 This is a side view of the present invention.

[0021] Figure 4 This is a schematic diagram of the first orientation assembly of the air intake pipe of the present invention.

[0022] Figure 5This is a schematic diagram of the second orientation assembly of the air intake pipe of the present invention.

[0023] Figure 6 This is a comparative diagram showing the velocity streamlines and vector diagram of the first cylinder.

[0024] Figure 7 This is a comparative diagram showing the velocity streamline and vector diagram of the second cylinder.

[0025] Figure 8 This is a comparative diagram showing the velocity streamline and vector diagram of the third cylinder.

[0026] Figure 9 This is the velocity streamline and vector diagram of the first cylinder in an embodiment of the present invention.

[0027] Figure 10 This is the velocity streamline and vector diagram of the second cylinder in an embodiment of the present invention.

[0028] Figure 11 This is the velocity streamline and vector diagram of the third cylinder in an embodiment of the present invention. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to specific embodiments and the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope or application of the present invention.

[0030] Non-limiting and non-exclusive embodiments will be described with reference to the following figures, wherein the same reference numerals denote the same parts unless otherwise specifically stated.

[0031] like Figure 1-5The diagram illustrates an intake manifold for a high-efficiency natural gas engine. The intake manifold 2 includes a mounting section 23, a guide section 22, and an intake section 21. The left end of the guide section 22 connects to the right end of the mounting section 23, and the right end connects to the intake section 21. The mounting section 23 has an opening 232 on its rear side, serving as the outlet of the intake manifold 2. Its left end is a pointed portion 233, meaning the angle between the left side surface 25 and the front side surface 24 of the mounting section 23 is acute, resulting in a pointed left end 233. Preferably, the junction of the left side surface 25 and the front side surface 24 of the mounting section 23 is a rounded chamfer, providing a smooth transition and facilitating airflow. When the intake air impacts the left side surface 25 of the mounting section 23, due to the slope of the left side surface 25, part of the intake direction changes, moving along the left side surface 25, thus dispersing the intake air. When using a non-pointed intake manifold, moisture in the intake air (especially humid air in the south) concentrates on the left side of the intake manifold, causing moisture to accumulate in cylinder 1, forming liquid water. This liquid water entering cylinder 1 can cause ignition failure, resulting in misfire. In other words, uneven moisture distribution in cylinders 1 and 2 leads to misfire in cylinder 1 due to liquid water entering. This embodiment, by providing a pointed section 233, can control the even distribution of intake air in cylinders 1 and 2 (located near the mounting section 23), preventing moisture from concentrating in cylinder 1 and eliminating the risk of misfire. Preferably, the angle between the left side 25 and the front side 24 of the mounting section 23 is 50-70°, preferably 60°.

[0032] The guide section 22 is an arc-shaped tube, lower on the left and higher on the right. Its left end faces the left side and connects to the inlet of the mounting section 23, while its right end faces the rear and connects to the outlet of the air intake section 21, ensuring that the air intake section 21 is at a horizontal height above the mounting section 23. Preferably, the air intake section 21 has an L-shaped tube structure, with its front end transitioning to the guide section 22 via an arc. Its rear end is the air inlet facing left and has a flange. The left end of the air intake section 21 gradually transitions from a round tube to a flat tube, and the end of the flat tube near the mounting section 23 gradually widens along the front-rear direction. Correspondingly, the mounting section is a flat tube with a pointed left end 233 and a gradually decreasing diameter flattened end on the right. The right end of the mounting section 23 smoothly transitions to the widened left end of the air intake section 21.

[0033] The mounting portion 23 forms a flow guide cavity inside, and the opening 232 on the rear side of the mounting portion 23 is a square opening. Several bolt connection holes 234 are provided on the outer side of the square opening. For example, the mounting portion 23 has three bolt connection holes 234 on its upper and lower sides respectively. The bolt connection holes 234 form raised ribs within the flow guide cavity. Preferably, a guide plate 231 is provided in the middle of the lower side of the mounting portion 23.

[0034] The guide plate 231 is arranged along the front-rear direction of the mounting part 23. Preferably, the guide plate 231 is provided on the rib of the bolt connection hole 234 on the lower side of the mounting part and extends along the rib. The height of the guide plate 231 is less than the height of the guide cavity, so that there is a gap between the upper side of the guide plate 231 and the upper side of the guide cavity. For example, the height of the guide plate 231 is 33-37mm, or half the height of the guide cavity. Preferably, the length of the guide plate 231 is less than the width of the guide cavity, that is, there is a gap between the front side of the guide plate 231 and the front side of the guide cavity. In a more preferred embodiment, the distance from the guide plate 231 to the right side of the square opening is less than the distance from the guide plate 23 to the left side of the square opening. By diverting the intake air through the guide plate 231, part of the intake air is guided to the second cylinder and subsequent third, fourth, etc., further avoiding the formation of condensate after a large amount of water vapor accumulates.

[0035] Combination Figure 4-5 It also includes an intake pipe 1, the front side of which has a through hole connecting to the rear side of the mounting part 23, and the rear side is open, serving as an outlet for connecting to the cylinder head intake passage. The interior of the intake pipe 1 has a U-shaped through groove without baffles, increasing the volume of the intake pipe 1. In this embodiment, the intake pipe 1 adopts a manifold-free design and has no baffles inside the pipe body, reducing airflow turbulence, which helps to reduce resistance and improve the uniformity of the engine air-fuel mixture.

[0036] Preferably, the angle between the front and left sides of the intake pipe 1 is an obtuse angle, making the left side 11 of the intake pipe 1 a slope. For example, the angle between the front and left sides of the intake pipe 1 is 100-130°, preferably 120°. This forms a ">" shape on the left side of the intake pipe 1 and the intake manifold 2, preventing condensate from directly hitting the first cylinder of the engine and causing misfire. It also helps distribute water vapor to the second cylinder, improving the water vapor uniformity between the first and second cylinders and ensuring smooth engine operation. Preferably, the left side of the intake pipe 1 includes a plane and a slope, wherein the angle between the slope and the front side of the intake pipe is an obtuse angle, and the plane is perpendicular to the cylinder head mounting surface. Thus, when the intake pipe 1 is installed on the cylinder head, the plane is perpendicular to the cylinder head mounting surface.

[0037] Figure 6-8 The vector diagram shows the velocity streamlines and vector diagrams of the first to third cylinders in the comparative example. The difference between the comparative example (code: V05) and the embodiment of the present invention (code: v05-opt3) is that the guide plate 231 is not provided. Figure 9-11 These are the velocity streamlines and vector diagrams of the first to third cylinders in an embodiment of the present invention. Figure 6-11 This is a vector diagram showing the streamlines and velocity of the cylinder at a valve lift of 12mm. C1-C2-C3 represent the first, second, and third cylinders of the engine, respectively.

[0038] contrast Figure 6 and Figure 9The air intake direction of C1 is opposite to the vortex rotation direction, thus suppressing the vortex ratio and reducing it. The hairpin bend (tip 233) protrudes and does not help the airflow, forming a flow vortex zone.

[0039] contrast Figure 7 and Figure 10 In V05-C2 (the second cylinder in the comparative example), the airflow enters the air passage relatively vertically, while in V05-opt3-C2 (the second cylinder in this embodiment), due to the presence of the guide plate 231, part of the airflow flows around it and eventually flows into the air passage at an angle, which plays the role of enhancing the vortex ratio.

[0040] contrast Figure 8 and Figure 10 V05-C3 enters the air passage at an angle, enhancing the vortex ratio. However, due to the presence of guide plate 231, some airflow around V05-opt3-C3, ultimately causing the airflow to tilt too much and become horizontal, thus reducing the vortex ratio. This facilitates the separation of water and air into the first and second cylinders.

[0041] Those skilled in the art will recognize that numerous variations are possible with respect to the above description, and the embodiments and figures are merely for describing one or more specific implementations.

[0042] Although exemplary embodiments of the invention have been described and illustrated, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the invention. Furthermore, many modifications can be made to adapt specific situations to the doctrine of the invention without departing from the central concepts of the invention described herein. Therefore, the invention is not limited to the specific embodiments disclosed herein, but may include all embodiments and equivalents that fall within the scope of the invention.

Claims

1. An intake pipe for a high-efficiency natural gas engine, characterized in that: The air intake pipe includes an installation part, a guide part, and an air intake part. The two ends of the guide part are respectively connected to the right end of the installation part and the air intake part. The installation part has an opening on the rear side and a pointed end on its left side.

2. The intake manifold of the high-efficiency natural gas engine as described in claim 1, characterized in that: The angle between the left side and the front side of the mounting part is an acute angle.

3. The intake manifold of the high-efficiency natural gas engine as described in claim 2, characterized in that: The left and front sides of the mounting part are rounded.

4. The intake manifold of the high-efficiency natural gas engine as described in claim 2, characterized in that: The angle between the left side and the front side of the mounting part is 50-70°.

5. The intake manifold of the high-efficiency natural gas engine as described in claim 1, characterized in that: The flow guide is an arc-shaped tube, with the left side lower than the right side, the left port facing the left side, and the right port facing the rear side.

6. The intake manifold of the high-efficiency natural gas engine as described in claim 1, characterized in that: The air intake is an L-shaped pipe structure, with its front end and the guide section transitioning to a rounded arc, and its rear port facing to the left.

7. The intake manifold of the high-efficiency natural gas engine as described in claim 1, characterized in that: The interior of the mounting section forms a flow guide cavity, and the opening connecting it to the air intake pipe is a square opening. Several bolt connection holes are provided on the upper and lower sides of the square opening; the bolt connection holes form raised ribs inside the flow guide cavity.

8. The intake manifold of the high-efficiency natural gas engine as described in claim 7, characterized in that: The guide plate is also provided in the flow guiding cavity of the mounting part, and the guide plate is arranged along the front and rear direction of the mounting part.

9. The intake manifold of the high-efficiency natural gas engine as described in claim 8, characterized in that: The guide plate is installed on the lower middle part of the flow guide cavity and is arranged on the bolt connection hole rib located in the middle.

10. The intake manifold of the high-efficiency natural gas engine as described in claim 9, characterized in that: The height of the guide plate is less than the height of the flow cavity, and the length of the guide plate is less than the width of the flow cavity.

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