An engine intake manifold and an automobile

Abstract

The present invention discloses an engine intake manifold, which includes an air intake air passage formed by an air intake inlet, a pressure stabilizing chamber and a plurality of intake manifold branch air passages, and an EGR distribution air passage independent of the air intake air passage. The EGR distribution air passage is correspondingly communicated with the plurality of intake manifold branch air passages through communication holes. The EGR distribution air passage evenly distributes EGR gas to the plurality of intake manifold branch air passages, and the EGR gas entering the intake manifold branch air passages is mixed with the air therein. The present invention also discloses an automobile having the above-mentioned engine intake manifold. Implementing the engine intake manifold and the automobile of the present invention can adjust the uniformity of the EGR rate; the structure is compact and intensive, saving layout space and reducing costs.

Description

Technical Field

[0001] The present invention relates to the field of automobile manufacturing, and particularly to an engine intake manifold and an automobile. Background Art

[0002] In the prior art, in most engine designs, the EGR gas is diverted to a section of the main pipe before the pressure stabilizing chamber and after the throttle installation flange of the intake manifold, so that the EGR gas and the air intake are mixed together and then enter the manifold pressure stabilizing chamber and are redistributed to each cylinder air passage.

[0003] The consistency of the EGR rate (EGR intake volume / total intake volume) of this structure depends on two factors: the intake consistency of the manifold air passages and whether the two gases can be mixed well before entering the pressure stabilizing chamber. Usually, the intake consistency of a qualified intake manifold air passage is designed to be within ±3% or even ±1%. Therefore, whether the EGR gas and the air can be mixed well before entering the pressure stabilizing chamber is the key to achieving better EGR rate consistency.

[0004] The traditional design is to design a relatively long section of the main pipe connecting the inlet of the intake manifold and the pressure stabilizing chamber (greater than 100 mm), and there are also problems that need to be solved, such as the need to connect and seal the EGR pipe and the intake manifold through a flange, the layout space, the installation space, and whether the EGR and the air can be mixed evenly before entering the pressure stabilizing chamber. If the distance from the throttle flange to the pressure stabilizing chamber is too short, the two gases do not have enough mixing space, which is very likely to cause the air passage closest to the intake inlet to receive the most EGR airflow, resulting in the worst combustion of the corresponding cylinder, thereby affecting the combustion consistency of each cylinder. Poor consistency will cause problems such as large engine vibration, and will also cause the engine to fail to achieve ideal fuel consumption and emission targets.

[0005] In addition, existing engine intake manifolds also have problems such as large space occupation, poor modal performance, increased EGR pressure loss due to a long EGR pipeline, and high development costs. For example: 1. The overall intake passage is biased to the right, resulting in a relatively large total width occupied by the manifold. Coupled with the total width after the throttle valve, it will exceed the rear end face of the engine. Together with the intake pipeline, it will occupy a relatively large space above the right transmission; 2. The farther the throttle valve is arranged from the cylinder block, the more unfavorable it is to the modal performance of the intake manifold. Manifolds with a longer main pipe usually result in the throttle valve being installed farther from the cylinder block side, greatly reducing the modal performance; 3. The long EGR pipeline leads to an increase in EGR pressure loss. Since the EGR flange faces upward, the EGR pipeline passes from the exhaust side around the rear end of the engine to the EGR flange of the intake manifold on the intake side. The EGR pipe is a metal pipe. Due to process reasons, such as the need to leave enough straight sections, the bent part of the metal pipeline is often long; 4. High development costs. During the engine thermodynamics development period, this part is a CNC part. Each piece of the structure is processed by a slicer and glued together to form a complete part, which is not detachable. When parameter adjustment and structure optimization are required during the experimental test period, the sample parts must be scrapped and new optimized CNC parts must be remade, resulting in high development costs, high time costs for optimizing and making sample parts, and high labor costs for disassembling and assembling parts. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an engine intake manifold and an automobile, which can adjust the EGR rate uniformity; have a compact and intensive structure, save layout space, and reduce costs.

[0007] To solve the above technical problems, an embodiment of the present invention provides an engine intake manifold, including: an air intake airway formed by an intake inlet, a pressure stabilizing chamber, and a plurality of intake manifold sub-airways, and an EGR distribution airway independent of the air intake airway. The EGR distribution airway is correspondingly connected to the plurality of intake manifold sub-airways through communication holes; the EGR distribution airway is integrated on the plurality of intake manifold sub-airways. The EGR distribution airway includes: an EGR inlet, a first distribution airway section connected to the EGR inlet, and a second distribution airway section connected to the first distribution airway section. Among them: the second distribution airway section is provided with a plurality of communication holes with adjustable aperture sizes, and the second distribution airway section is correspondingly connected to the plurality of intake manifold sub-airways through the communication holes; an outlet insert is provided on the center line of the outlet of the second distribution airway section; the aperture size of the communication hole is adjusted by changing the aperture size of the outlet insert; a step hole for assembling the outlet insert is provided inside the intake manifold sub-airway; the cross-section of the pressure stabilizing chamber tapers from the proximal end connected to the intake inlet to the distal end connected to the intake inlet.

[0008] Among them, the EGR distribution airway further includes: an EGR lower sheet for forming the first distribution airway section and the second distribution airway section, and a plurality of EGR covers respectively detachably connected to the EGR lower sheet.

[0009] Among them, the EGR gas passing through the EGR inlet is evenly divided into two airflows in the first air distribution airway section, and then evenly divided into four airflows in the second air distribution airway section.

[0010] Among them, the airway between the inlet and the relatively far outlet of the second air distribution airway section forms an obtuse-angled structure, and the airway between the inlet and the relatively near outlet of the second air distribution airway section forms an acute-angled structure.

[0011] Among them, the intake manifold branch airways are set to four, which are respectively curled around the outer surface of the pressure stabilizing cavity; the lengths of the four intake manifold branch airways are set to be equal; sealed mounting flanges are respectively installed at the ends of the four intake manifold branch airways.

[0012] To solve the above technical problems, the present invention also discloses a vehicle.

[0013] The engine intake manifold and the vehicle provided by the present invention have the following beneficial effects: The engine intake manifold includes an air intake airway formed by an intake inlet, a pressure stabilizing cavity and a plurality of intake manifold branch airways, and an EGR distribution airway independent of the air intake airway. The EGR distribution airway is correspondingly communicated with the plurality of intake manifold branch airways through communication holes. The EGR distribution airway evenly distributes the EGR gas to the plurality of intake manifold branch airways. The EGR gas entering the intake manifold branch airways is mixed with the air therein. Through the design of the airway direction and the aperture design of the communication holes, the uniformity of the EGR rate can be effectively adjusted. The structure of integrating the EGR distribution airway on the intake manifold branch airway is more compact and intensive, saving layout space and reducing costs. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a schematic structural diagram of the engine intake manifold according to an embodiment of the present invention.

[0016] Figure 2 It is a schematic blasting structure diagram of the EGR distribution airway of the engine intake manifold according to an embodiment of the present invention.

[0017] Figure 3 It is a schematic side view structural diagram of the engine intake manifold according to an embodiment of the present invention.

[0018] Figure 4It is a partially enlarged structural schematic diagram of the engine intake manifold according to an embodiment of the present invention. Detailed implementation manners

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0020] Refer to Figures 1 - 4 As shown, it is the first embodiment of the engine intake manifold of the present invention.

[0021] The engine intake manifold in this embodiment is applied to an automobile. The engine intake manifold includes: an intake inlet 11 for installing and sealing a throttle valve; a pressure stabilizing chamber 12 connected to the intake inlet 11; a plurality of intake manifold branch airways 13 respectively connected to the pressure stabilizing chamber 12. The plurality of intake manifold branch airways 13 are respectively wound around the outside of the pressure stabilizing chamber 12. The intake inlet 11, the pressure stabilizing chamber 12 and the plurality of intake manifold branch airways 13 form an air intake airway 1. The air flow direction in the air intake airway 1 in the figure is X; and

[0022] An EGR distribution airway 2 independent of the air intake airway 1. The EGR distribution airway 2 is integrated on the plurality of intake manifold branch airways 13. The EGR distribution airway 2 includes: an EGR inlet 22, a first distribution airway segment 21a connected to the EGR inlet 22, and a second distribution airway segment 21b connected to the first distribution airway segment 21a. The air flow directions in the first distribution airway segment 21a and the second distribution airway segment 21b of the EGR distribution airway 2 in the figure are Y;

[0023] Wherein: the second distribution airway segment 21b is provided with a plurality of communication holes 241 with adjustable aperture sizes. The second distribution airway segment 21b is correspondingly connected to the plurality of intake manifold branch airways 13 through the communication holes 241. The EGR distribution airway 2 evenly distributes the EGR gas to the plurality of intake manifold branch airways 13, and the EGR gas entering the intake manifold branch airways 13 is mixed with the air therein.

[0024] In the engine intake manifold of this embodiment, by adjusting the inner diameter of the communication hole, the EGR distribution airway 2 plays a role in optimizing efficiency and reducing development costs during the thermodynamic development of the engine. The air intake airway 1 introduces the air passing through the throttle valve from the intake inlet 11 into the pressure stabilizing chamber 12, and then distributes it to each intake manifold sub-airway 13 through the pressure stabilizing chamber 12. The EGR distribution airway 2 introduces the exhaust gas passing through the EGR valve from the EGR inlet 22 into the first distribution airway section 21a and the second distribution airway section 21b. After passing through the two distribution airway sections, it enters the intake manifold sub-airway 13 at the communication hole to mix the EGR gas with the air therein, and the mixed gas then forms a mixed air flow towards each cylinder of the engine. The reasonable design of the intake manifold airway and the structure of the EGR distribution airway 2 can, on the one hand, ensure the consistency of air intake for the four cylinders, and on the other hand, ensure the consistency of the EGR rate (EGR intake volume / total intake volume) for each cylinder. Good consistency is beneficial to optimizing engine performance such as emissions, and also helps to reduce engine vibration and noise.

[0025] During specific implementation, the intake inlet 11 is arranged at the side end of the engine intake manifold. The intake inlet 11 is a straight cylindrical pipe with a short length. A mounting flange is designed and installed at the intake inlet 11, and is equipped with a sealing ring for the installation and sealing of the throttle valve. The pressure stabilizing chamber 12 is tightly connected to the intake inlet 11. The pressure stabilizing chamber 12 is wrapped within the intake manifold sub-airway 13, and the cross-section of the pressure stabilizing chamber 12 tapers and narrows from the proximal end connected to the intake inlet 11 to the distal end connected to the intake inlet 11. The function of such a setting is to make the air entering the intake manifold sub-airway 13 uniform. For example, by expanding the cross-section of the airway inlet of the cylinder closest to the inlet of the pressure stabilizing chamber 12 and adding flow guiding ribs inside the pressure stabilizing chamber, etc., the intake difference between the four cylinders is balanced, the intake deviation is minimized, and the intake flow consistency is controlled within ±1%.

[0026] In this embodiment, the intake manifold sub-airways 13 are provided in four, and are respectively curled and surrounded on the outer surface of the pressure stabilizing chamber 12; the four intake manifold sub-airways 13 are arranged in a row along the pressure stabilizing chamber 13 and have equal lengths. Sealed mounting flanges are respectively installed at the ends of the four intake manifold sub-airways 13 for connecting the airways.

[0027] Furthermore, the EGR distribution airway 2 is integrated and closely attached to the outer surface of the intake manifold sub-airway 13. The air intake airway 1 and the EGR distribution airway 2 are two independent airway parts, and are only connected by a communication hole at the ends of the two airways respectively.

[0028] During specific implementation, the EGR distribution airway 2 includes: an EGR inlet 22, a first distribution airway section 21a connected to the EGR inlet 22, and a second distribution airway section 21b connected to the first distribution airway section 21a. Among them: the EGR inlet 22 is connected with a flange and is equipped with a sealing ring for the installation and sealing of the EGR valve or the EGR pipeline.

[0029] The first distribution air passage segment 21a and the second distribution air passage segment 21b are constituted by the EGR lower piece 21 of the EGR distribution air passage 2. The EGR lower piece 21 is an assembly structure with a hollow chamber inside, and the flow passage formed by its internal chamber is the first distribution air passage segment 21a and the second distribution air passage segment 21b.

[0030] Furthermore, the gas inlet of the first distribution air passage segment 21a of the hollow chamber of the EGR lower piece 21 is connected to the EGR inlet 22. The first distribution air passage segment 21a has two gas outlets with opposite directions, which are respectively connected to the two gas inlets of the second distribution air passage segment 21b. The second distribution air passage segment 21b has four gas outlets. That is to say, the EGR gas passing through the EGR inlet 22 is evenly divided into two airflows in the first distribution air passage segment 21a, and then is evenly divided into four airflows in the second distribution air passage segment 21b.

[0031] Preferably, a connecting flange is provided on the EGR inlet 22. Under the condition allowed by the overall engine layout, this structure can be used to directly install the EGR valve and play a sealing role at the same time, canceling the use of the EGR pipeline between the EGR valve and the intake manifold, and reducing the cost. Under the condition where the layout does not allow, the connecting flange can also be used to dock with the EGR pipeline and can also play a sealing role. However, the connecting structure at the EGR inlet 22 is not limited to the illustrated flange structure. For example, on an engine with a relatively low EGR temperature, the EGR pipe may be connected to the intake manifold by a hose, that is, by an interference fit plus a clamp fixation method, and only a cylindrical pipe joint with corresponding dimensions needs to be designed at the intake manifold end.

[0032] Furthermore, outlet inserts 24 are respectively provided on the center lines of the four gas outlet positions of the second distribution air passage segment 21b. Correspondingly, a stepped hole for assembling the outlet insert 24 is provided inside the intake manifold sub-air passage 13. Four outlet inserts 24 are provided and are correspondingly assembled in the stepped holes. In this embodiment, the communication hole 241 is a through hole opened in the outlet insert 24, and there are also four communication holes 241. The aperture size of the communication hole 241 can be adjusted by changing the aperture size of the outlet insert 24.

[0033] By providing the stepped hole, it is possible to prevent the situation where the outlet insert 24 is not firmly fixed and has an adverse effect on the air flow. In addition, the outlet insert 24 can also be adhesively fixed to the stepped hole in an easily removable manner.

[0034] Preferably, the inner diameter of the outlet insert 24 can be precisely modified by machining. The function of this setting is that the detachable and modifiable-aperture outlet insert 24 is the key to optimizing performance during the engine thermodynamic development stage, and it affects the formation position of the communication hole 241 and the gas flow rate. For example, the more the center of the communication hole 241 deviates from the center line, the greater the risk that the final gas flow will go to the airway on one side, which will affect in-cylinder combustion.

[0035] Preferably, an openable EGR cover plate 23 is provided at the upper end of the EGR distribution airway 2 corresponding to each communication hole 241. The EGR cover plate 23 is installed and sealed on the second distribution airway section 21b of the EGR distribution airway 2 through a sealing ring 231 and bolts 232, and can be disassembled and assembled repeatedly. The inner surface of the EGR cover plate 23 and its corresponding EGR lower piece 21 together form a distribution airway with a smooth inner surface. Among them, the sealing ring 231 can ensure the connection tightness between the EGR cover plate 23 and the EGR lower piece 21.

[0036] The function of setting the detachable EGR cover plate 23 is that the engine intake manifold in this embodiment can be used during the thermodynamic development stage. Each structural part is usually machined and then fixedly connected by sealant and nails to form a non-detachable whole. Only the EGR cover plate 23 has a structure that can be flexibly disassembled and assembled through the sealing ring 231 and bolts 232, enabling the operation of replacing the outlet insert 24 to be completed by opening the EGR cover plate 23, thereby realizing the adjustability of the internal airway parameters.

[0037] It can be understood that the structures of the first distribution airway section 21a and the second distribution airway section 21b of the EGR distribution airway 2 contribute to evenly distributing the EGR gas to the four airways connected to the intake manifold sub-airways 13, which is beneficial to the combustion consistency of the engine.

[0038] During specific implementation, the EGR distribution airway 2 starts from the EGR inlet 22. The EGR gas passing through the EGR inlet 22 is evenly divided into two airflows in the first distribution airway section 21a, and then evenly divided into four airflows in the second distribution airway section 21b. During the process of the gas passing from the first distribution airway section 21a to the second distribution airway section 21b, the airway between the inlet and the relatively far outlet of the second distribution airway section 21b forms an obtuse structure A, and the airway between the inlet and the relatively near outlet of the second distribution airway section 21b forms an acute structure B.

[0039] In the specific implementation of the engine intake manifold of the present invention, air enters the pressure stabilizing chamber 12 from the intake inlet 11 after passing through the throttle valve, and is divided into four independent intake manifold sub-airways 13 from the pressure stabilizing chamber 12. When the EGR valve is in the open state, the EGR gas passes through the EGR valve, is introduced into the EGR inlet 22 of the EGR distribution airway 2 from the pipeline after the valve, and then is introduced into the first distribution airway section 21a and the second distribution airway section 21b, and finally the EGR gas is evenly distributed to multiple intake manifold sub-airways 13, and the EGR gas entering the intake manifold sub-airway 13 is mixed with the air therein, and the mixed air enters the cylinder head airway together to participate in the combustion process.

[0040] In this process, after the overall direction of the airway is optimized through simulation calculation and structural arrangement, there are often some deviations between the simulation and the test value. During the thermodynamic development, the aperture size of the outlet insert 24 of the EGR distribution airway 2 corresponding to each cylinder is adjusted through the difference of the EGR rate of each cylinder measured by the test, and the consistency of the EGR rate is further optimized. Without removing the intake manifold, open the EGR cover 23 corresponding to a cylinder whose EGR outlet aperture needs to be modified, replace the previous EGR outlet insert with the latest outlet insert 24, reinstall the EGR cover 23, and retest the EGR rate to obtain the optimal parameters.

[0041] The engine intake manifold of the present invention can firstly ensure the consistency of air intake of each cylinder, for example, the pressure stabilizing chamber is designed as a structure with a tapered cross-section. Secondly, it can also ensure the consistency of the EGR rate (EGR intake volume / total intake volume) of each cylinder. On the one hand, the EGR distribution airway 2 is set as a branch distribution airway. On the premise of avoiding the installation space, the gas channels leading to each branch airway are designed to compensate for the differences, thereby improving the consistency of the EGR rate; on the other hand, the inner diameter of the outlet of the EGR distribution airway 2 can be adjusted, so that the assembly structure can be further verified by experiments during the part performance development stage to achieve the best.

[0042] In other embodiments, the structure of the adjustable aperture of the connecting hole 241 of the outlet insert 24 is mainly suitable for the part performance test stage. After determining the best performance solution, the EGR cover plate 23 does not need to be made into a detachable structure, and can be directly made into an integral part with the EGR lower plate 21 by injection molding, and then directly welded to the intake manifold air intake duct 1. The insert 25 structure inside the EGR distribution duct 2 can also be integrally injection molded with the EGR distribution duct 2.

[0043] The engine intake manifold and automobile implementing the present invention have the following beneficial effects:

[0044] First, the modality is improved. Compared with the intake manifold with a long manifold behind the throttle, the installation position of the throttle fits the parts and is closer to the cylinder side, which greatly helps to improve the modality and enhance the NVH performance.

[0045] Second, it takes up little space. Since the main pipe after the throttle valve is reduced and the EGR distribution pipe is arranged in full contact with the surface, this structure takes up little space, making the engine layout more compact.

[0046] Third, the uniformity of air intake is improved. By rationally designing the shape of the pressure stabilizing chamber, combining the differentiated design of the air intake and the use of guide ribs inside the pressure stabilizing chamber, the uniformity of air intake can be ensured, ensuring the consistency of combustion in the four cylinders.

[0047] Fourth, the uniformity of EGR gas is improved. The uniformity of EGR is adjusted by adjusting the direction of the EGR distribution channel from the inlet to the first distribution channel section 21a and the second distribution channel section 21b; in addition, the aperture of the EGR outlet (outlet insert) is designed to be adjustable, so that the ideal optimal structure can be adjusted more accurately during the test phase.

[0048] Fifth, EGR pressure loss is small. The EGR inlet is designed as a right-facing curved pipe (injection-molded with the manifold plastic). Since the injection molding process is more flexible than the bending of metal pipes, this section of curved pipe is made of plastic integrally to shorten the length of the inlet pipe. At the same time, it also makes the path of gas entering the distribution airway at the inlet smoother, which helps to reduce pressure loss and increase the EGR rate.

[0049] Sixth, improve development efficiency and reduce development costs. The EGR outlet (outlet insert) aperture is adjustable. Without increasing the number of samples, removing the intake manifold, or waiting for the sample production cycle, the consistency of the EGR outlet (outlet insert) inner diameter adjustment can be changed, thereby improving optimization efficiency and reducing sample costs during development.

Claims

1. An engine intake manifold, characterized in that, Comprising: An air intake airway formed by an air intake inlet, a pressure stabilizing chamber, and a plurality of intake manifold branch airways, and an EGR distribution airway independent of the air intake airway, the EGR distribution airway being correspondingly communicated with the plurality of intake manifold branch airways through communication holes; The EGR distribution airway is integrated on the plurality of intake manifold branch airways, and the EGR distribution airway includes: an EGR inlet, a first distribution airway segment communicated with the EGR inlet, and a second distribution airway segment communicated with the first distribution airway segment, wherein: the second distribution airway segment is provided with a plurality of communication holes with adjustable pore sizes, and the second distribution airway segment is correspondingly communicated with the plurality of intake manifold branch airways through the communication holes; An outlet insert is provided on the center line of the outlet of the second distribution airway segment; the pore size of the communication hole is adjusted by changing the pore size of the outlet insert, and a stepped hole for assembling the outlet insert is provided inside the intake manifold branch airway; The cross-section of the pressure stabilizing chamber tapers and narrows from the proximal end connected to the air intake inlet to the distal end connected to the air intake inlet.

2. The engine intake manifold according to claim 1, characterized in that The EGR distribution airway further includes: an EGR lower piece for forming the first distribution airway segment and the second distribution airway segment, and a plurality of EGR cover plates respectively detachably connected to the EGR lower piece.

3. The engine intake manifold according to claim 2, wherein The EGR gas passing through the EGR inlet is evenly divided into two airflows in the first distribution airway segment, and then evenly divided into four airflows in the second distribution airway segment.

4. The engine intake manifold according to claim 3, characterized in that, The airway between the inlet and the relatively far outlet of the second distribution airway segment forms an obtuse-angled structure, and the airway between the inlet and the relatively near outlet of the second distribution airway segment forms an acute-angled structure.

5. The engine intake manifold according to claim 1, characterized in that, The intake manifold branch airways are provided in four, and are respectively curled around the outer surface of the pressure stabilizing chamber; The lengths of the four intake manifold branch airways are set to be equal; Sealed mounting flanges are respectively installed at the ends of the four intake manifold branch airways.

6. A vehicle, characterized in that, The vehicle includes the engine intake manifold according to any one of claims 1-5.

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