CN115478966A

CN115478966A - Engine air intake system

Info

Publication number: CN115478966A
Application number: CN202110666227.XA
Authority: CN
Inventors: 黄英铭; 占文锋; 韦静思; 徐琳; 吕伟
Original assignee: Guangzhou Automobile Group Co Ltd
Current assignee: Guangzhou Automobile Group Co Ltd
Priority date: 2021-06-16
Filing date: 2021-06-16
Publication date: 2022-12-16
Anticipated expiration: 2041-06-16
Also published as: CN115478966B

Abstract

The present invention provides an engine intake system, comprising: the first supercharger comprises a first air inlet end communicated with a compressor impeller, a first air outlet end, a second air inlet end and a second air outlet end communicated with a turbine impeller, the first air inlet end is connected with the first air inlet main path, the second air inlet end is connected with the exhaust manifold, the second air inlet main path is connected between the first air outlet end of the first supercharger and the air inlet manifold, a first intercooler is arranged on the second air inlet main path, the second supercharger is connected with a part of pipelines of the second air inlet main path in parallel, the second supercharger is located at the downstream of the first intercooler, and a second intercooler is integrated in the air inlet manifold.

Description

Engine air intake system

Technical Field

The invention relates to the field of automobile engines, in particular to an engine air inlet system.

Background

Turbochargers are widely used in vehicles for increasing the amount of intake air to the engine. The turbocharger comprises a turbine impeller communicated with an engine exhaust passage and a compressor impeller communicated with an engine intake passage, and the turbine impeller and the compressor impeller are connected through a shaft; after the engine is started, the exhaust gas discharged by the cylinder enters the turbocharger to push the turbine impeller to rotate, so that the compressor impeller synchronously rotates, outside air is sucked into the combustion chamber, the air inflow of the engine is improved, the oil injection quantity of the engine is increased, and the purpose of improving the power of the engine is finally achieved.

As can be seen from the above principle, the effect of the turbocharger on increasing the power of the engine depends on the exhaust energy of the engine, and the larger the exhaust energy is, the faster the turbine wheel rotates, and the larger the amount of air sucked by the compressor wheel per unit time is; when the engine is in a cold start or rapid acceleration or low-speed or low-load working condition, the energy of the exhaust gas discharged by the cylinder is smaller, the rotating speed of the turbine impeller is smaller, and the rotating speed of the compressor impeller is also smaller; thus, when the engine is in a cold start or a rapid acceleration or a low speed or low load condition, the single turbocharger can hardly play a role in increasing the power of the engine due to the lack of power, or has slow response and needs long reaction time.

Based on this, technicians generally set up a plurality of superchargers to solve the above problems. However, the number of components of the intake system with a plurality of superchargers is large, the space required for arrangement is large, and after the gas is sucked by the plurality of superchargers and compressed to increase the speed, the temperature of the gas is increased, the volume of the gas is expanded, and finally the intake air quantity of the engine is too low, so that the aim of increasing the power of the engine cannot be achieved.

Disclosure of Invention

In view of the above, the present invention aims to provide an engine intake system with a compact structure.

The invention provides an engine air inlet system, which comprises: the engine cylinder comprises an air inlet manifold, an engine cylinder, an exhaust manifold, a first supercharger, a second supercharger, a first main air inlet path and a second main air inlet path, wherein the air inlet manifold and the exhaust manifold are respectively arranged at an air inlet end and an exhaust end of the engine cylinder, the first supercharger comprises a first air inlet end and a first air outlet end communicated with a compressor impeller and a second air inlet end and a second air outlet end communicated with a turbine impeller, the first air inlet end is connected with the first main air inlet path, the second air inlet end is connected with the exhaust manifold, the second main air inlet path is connected between the first air outlet end of the first supercharger and the air inlet manifold, a first intercooler is arranged on the second main air inlet path, the second supercharger is connected with a part of pipelines of the second main air inlet path in parallel, the second supercharger is positioned at the downstream of the first intercooler, and a second intercooler is integrated in the air inlet manifold.

Optionally, the second intercooler is integrated in a surge chamber of the intake manifold.

Optionally, the second supercharger comprises a supercharging inlet and a supercharging outlet, the supercharging inlet is connected with the second air intake main passage through a first pipeline, and the supercharging outlet is connected with the second air intake main passage through a second pipeline.

Optionally, an included angle between the first pipeline and a part of the second main intake air path located upstream of the first pipeline is an obtuse angle, and an included angle between the second pipeline and a part of the second main intake air path located downstream of the second pipeline is an obtuse angle.

Optionally, an electronic throttle valve is arranged on a part of pipelines of the second main intake passage and the second supercharger in parallel.

Optionally, the turbocharger further comprises a backflow branch and an electric valve arranged on the backflow branch, one end of the backflow branch is communicated with the first main air intake passage, the other end of the backflow branch is communicated with the second main air intake passage, a connection point of the backflow branch and the first main air intake passage is located at the upstream of the first supercharger, and a connection point of the backflow branch and the second main air intake passage is located at the downstream of the second pipeline.

Optionally, a throttle valve is further disposed on the second main intake passage, and the throttle valve is located downstream of a connection point of the return branch and the second main intake passage.

Optionally, the first supercharger is a turbocharger, the second supercharger is an electric supercharger, and the second supercharger is connected with a 48V power supply.

Optionally, the first intercooler, the second intercooler, and the second supercharger are each cooled by a cooling system independent of the engine.

Optionally, the volume of the second intercooler is smaller than the volume of the first intercooler.

In summary, the present invention provides a flow strategy of air in an intake system of an engine by reasonably designing the relative position and the matching manner between a first supercharger and a second supercharger, and arranging a plurality of intercoolers for the first supercharger and the second supercharger, and reasonably configuring the position and the volume of each intercooler in the intake system, so as to provide a system which has a compact structure, simplified components, flexible arrangement, and less required space, and which can provide strong power according to the requirements of users even when the engine is in a working condition not conducive to the operation of the superchargers.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of an engine air intake system provided by an embodiment of the invention.

Fig. 2 is a schematic diagram of a first supercharger provided in an embodiment of the present invention.

Description of the reference numerals

I-a first main air inlet path, II-a second main air inlet path and III-a reflux branch;

1-a first supercharger, 101-a first air inlet end, 102-a first air outlet end, 103-a second air inlet end, 104-a second air outlet end;

2-second supercharger, 201-boost inlet, 202-boost outlet;

3-a first intercooler, 4-a second intercooler, 5-an intake manifold, 6-an engine cylinder, 7-an exhaust manifold, 8-48V power supply, 9-an electronic throttle valve, 10-a first pipeline, 11-a second pipeline, 12-a throttle valve, 13-an electric valve, 14-an air filter and 15-an aftertreatment system.

Detailed Description

The following detailed description of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The terms first, second and the like in the description and in the claims of the present invention are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

As shown in fig. 1, the present invention provides an engine intake system, which comprises an air cleaner 14, a first main intake path I, a second main intake path II, a first supercharger 1, a second supercharger 2 powered by a 48V power supply 8, a first intercooler 3, a second intercooler 4, an intake manifold 5, an engine cylinder 6, an exhaust manifold 7 and an aftertreatment system 15.

In the engine intake system provided in the present embodiment, the first supercharger 1 is a turbocharger, and the second supercharger 2 is an electric supercharger. Referring also to fig. 2, the first supercharger 1 includes a first inlet port 101 and a first outlet port 102 communicating with the compressor wheel, and a second inlet port 103 and a second outlet port 104 communicating with the turbine wheel.

The first air inlet end 101 is communicated with one end of a first air inlet main path I, the first air outlet end 102 is communicated with one end of a second air inlet main path II, the other end of the first air inlet main path I is communicated with an air filter 14 and used for sucking outside air, the other end of the second air inlet main path II is communicated with an air inlet manifold 5, the air inlet manifold 5 is connected with an engine cylinder 6, the engine cylinder 6 is connected with an exhaust manifold 7, the exhaust manifold 7 is communicated with a second air inlet end 103 of a first supercharger 1, and a second air outlet end 104 of the first supercharger 1 is communicated with an aftertreatment system 15. When the engine works, the engine cylinder 6 discharges exhaust gas through the exhaust manifold 7, the exhaust gas enters the first supercharger 1 through the second air inlet 103, pushes the turbine impeller, then leaves the first supercharger 1 from the second air outlet 104, meanwhile, the turbine impeller drives the compressor impeller to rotate, outside air is sucked into the first supercharger 1 from the first air inlet 101, leaves the first supercharger 1 from the first air outlet 102 after being accelerated by the impeller, and enters the second main air inlet path II.

The first intercooler 3 is located on the second main air intake path II and used for cooling air entering the second main air intake path II from the first supercharger 1 so as to counteract the influence of gas temperature rise and gas volume expansion on air inflow caused by the work of the compressor impeller on the air and achieve the purpose of introducing more air into the second main air intake path II in unit time.

The second supercharger 2 is located at the downstream of the first intercooler 3, an inlet and an outlet of the second supercharger are communicated with a second main air inlet path II, and a gas branch which is connected with partial pipelines of the second main air inlet path II in parallel is formed on the second main air inlet path II. During the operation of the engine, cooled air leaves the first intercooler 3 and then flows to the branch of the second main intake path II and the second supercharger 2. The second supercharger 2 comprises a supercharging inlet 201 and a supercharging outlet 202, the supercharging inlet 201 is communicated with a second main air intake path II behind the first intercooler 3 through a first pipeline 10, and the supercharging outlet 202 is communicated with the second main air intake path II through a second pipeline 11; and a normally open electronic throttle valve 9 is arranged between a communication port of the first pipeline 10 and the second air inlet main path II and a communication port of the second pipeline 11 and the second air inlet main path II, namely on a part of pipelines of the second air inlet main path II connected with the second supercharger 2 in parallel.

The purpose of the electronic throttle valve 9 is to: when the engine is not in a working condition which is not beneficial to the work of the first supercharger 1, the electronic throttle valve 9 is opened, so that the second main intake passage II between the supercharging inlet 201 and the supercharging outlet 202 is in a passage state, the second supercharger 2 is enabled to run at the lowest output idling speed, most of air leaving the first intercooler 3 can flow to the second main intake passage II, and the purpose of improving the air intake of the engine is achieved. In addition, compare in traditional mechanical check valve, electronic throttle valve 9 can reduce the throttle loss, reduces the second booster 2 and does not operate the intake resistance in the time of the time pipeline, reduces parallelly connected second booster 2 and to the negative effects of pipeline, plays the effect that reduces the oil consumption and guarantees engine maximum power.

When the engine is in a working condition which is not beneficial to the working of the first supercharger 1, the electronic throttle valve 9 is closed, so that the air leaving the first intercooler 3 flows into the second supercharger 2, the second supercharger 2 is enabled to operate at normal output power, the air quantity entering and discharging the engine cylinder 6 in unit time can be increased, the impeller of the air compressor is driven by the waste gas discharged from the engine cylinder 6, the working load of the second supercharger 2 is reduced, positive feedback is formed, and the defect that the work capacity of the first supercharger 1 is weak when the engine is in the working condition which is not beneficial to the working of the first supercharger 1 is overcome. In the present invention, the aforementioned conditions not conducive to the operation of the first supercharger 1 include conditions such as cold start or rapid acceleration of the engine or low speed or low load, and it is within the ability of those skilled in the art to redefine or expand the range encompassed by the conditions not conducive to the operation of the first supercharger 1 either experimentally or as technology evolves.

It should be particularly noted that, in the present invention, the first pipeline 10 and the second main intake air path II are close to the first intercooler 3, that is, an included angle between the first pipeline 10 and a part of the second main intake air path II located at the upstream thereof is an obtuse angle; the second pipeline 11 and one side of the second main intake air path II far away from the first intercooler 3, that is, an included angle between the second pipeline 11 and a part of the second main intake air path II located at the downstream thereof is an obtuse angle. The purpose of this setting is to reduce the air flow loss, energy saving.

Furthermore, a return branch III is branched from the second main air intake path II at the downstream of a communication port between the second pipeline 11 and the second main air intake path II, an electric valve 13 capable of controlling the on-off of a loop is arranged on the return branch III, one end of the return branch III is positioned between the second supercharger 2 and the air intake manifold 5 and is positioned at the downstream of the second supercharger 2, and the other end of the return branch III is communicated with the first main air intake path I and is positioned between the air filter 14 and the first supercharger 1; downstream of the junction of the return branch III with the second main intake tract II there is also a throttle valve 12. Therefore, when the throttle valve 12 is closed due to the fact that the throttle is loosened in the running process of the vehicle, only the electric valve 13 needs to be controlled to be opened, high-pressure gas rapidly gathered in the second air intake main path II can be led back to the first air intake main path I, the second air intake main path II is prevented from being damaged due to overlarge pressure, meanwhile, the first supercharger 1 can be maintained to continuously run, and huge rotation speed fluctuation is avoided.

In the working process of the engine, after air passes through the throttle valve 12, the air enters the second intercooler 4 to be cooled for the second time, so that the influence of the gas temperature rise and the gas volume expansion on the air inflow caused by the second supercharger 2 doing work on the air is counteracted; then, the air enters the intake manifold 5 and the engine cylinder 6 in sequence, becomes exhaust gas after combustion, is discharged from the exhaust manifold 7, enters the first supercharger 1 through the second intake end 103, pushes the turbine wheel to do work, and is discharged through the second exhaust end 104.

It should be noted that the first intercooler 3, the second intercooler 4 and the second supercharger 2 are respectively cooled by a cooling system independent of the engine, and the volume of the second intercooler 4 is smaller than that of the first intercooler 3 and is integrated with the intake manifold 5 to form an integrated water-cooled intake manifold; the second intercooler 4 is integrated in a surge tank of the intake manifold 5. In the related technology, the design difficulty of the integrated water-cooling intake manifold is directly influenced by the size of an intercooler in the integrated water-cooling intake manifold, and the larger the intercooler is, the higher the design difficulty is, the higher the cost is, and the larger the influence on the performance of the original intake manifold is; therefore, an important design idea of this embodiment is to adopt two-stage cooling, make gas pass through first intercooler 3 earlier by the primary cooling, then pass through second intercooler 4 again, so, just can adopt the less intercooler of volume in second intercooler 4 to save integrated form water-cooling intake manifold's overall arrangement space, reduce integrated form intake manifold's the design degree of difficulty and design cost and to the influence of former intake manifold performance. Of course, the person skilled in the art can suitably adjust the size of the two charge air coolers according to the heat load and the spatial arrangement, and the volume relationship between the first charge air cooler 3 and the second charge air cooler 4 is a negative correlation relationship with the cooling target being constant.

In summary, the present invention provides a compact structure, simplified components, flexible arrangement, less space required, and the air intake system provides strong power according to the needs of the user even when the engine is in a working condition not conducive to the operation of the supercharger, by reasonably designing the relative position and the matching manner between the first supercharger 1 and the second supercharger 2, defining the flow direction strategy of the air in the air intake system of the engine, and arranging a plurality of intercoolers for the first supercharger 1 and the second supercharger 2, and reasonably configuring the position and the volume of each intercooler in the air intake system.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. An engine air intake system, comprising: the turbocharger comprises an air inlet manifold (5), an engine cylinder (6), an exhaust manifold (7), a first supercharger (1), a second supercharger (2), a first air inlet main path (I) and a second air inlet main path (II), wherein the air inlet manifold (5) and the exhaust manifold (7) are respectively arranged at an air inlet end and an exhaust end of the engine cylinder (6), the first supercharger (1) comprises a first air inlet end (101) and a first air outlet end (102) which are communicated with a compressor impeller, and a second air inlet end (103) and a second air outlet end (104) which are communicated with a turbine impeller, the first air inlet end (101) is connected with the first air inlet main path (I), the second air inlet end (103) is connected with the exhaust manifold (7), the second air inlet main path (II) is connected between the first air outlet end (102) of the first supercharger (1) and the air inlet manifold (5), a first intercooler (3) is arranged on the second air inlet main path (II), the second air inlet main path (2) is connected with the second supercharger (2) in parallel, and a second air inlet main path (4) is arranged in the second intercooler (4).

2. An engine air inlet system according to claim 1, characterised in that the second charge air cooler (4) is integrated in a surge tank of the inlet manifold (5).

3. Engine air intake system according to claim 1, wherein the second supercharger (2) comprises a supercharging inlet (201) and a supercharging outlet (202), the supercharging inlet (201) being connected to the main second intake tract (II) by a first duct (10), the supercharging outlet (202) being connected to the main second intake tract (II) by a second duct (11).

4. An engine air intake system according to claim 3, wherein: the included angle between the first pipeline (10) and the part of the second main air intake path (II) positioned at the upstream of the first pipeline is an obtuse angle, and the included angle between the second pipeline (11) and the part of the second main air intake path (II) positioned at the downstream of the second pipeline is an obtuse angle.

5. An engine air intake system according to claim 3, characterized in that an electronic throttle valve (9) is provided on a part of the pipe of the second main intake air path (II) in parallel with the second supercharger (2).

6. The engine intake system according to claim 1, characterized in that it further comprises a return branch (III) having one end communicating with the first main intake tract (I) and the other end communicating with the second main intake tract (II), and an electric valve (13) arranged on the return branch (III), the connection point of the return branch (III) with the first main intake tract (I) being located upstream of the first supercharger (1), and the connection point of the return branch (III) with the second main intake tract (II) being located downstream of the second pipeline (11).

7. An engine air intake system according to claim 6, characterized in that a throttle valve (12) is also provided on the second main intake air path (II), the throttle valve (12) being located downstream of the connection point of the return branch (III) with the second main intake air path (II).

8. An engine air intake system according to claim 1, wherein the first supercharger (1) is a turbocharger and the second supercharger (2) is an electric supercharger, and the second supercharger (2) is connected to a 48V power supply (8).

9. An engine air inlet system according to claim 1, characterised in that the first charge air cooler (3), the second charge air cooler (4) and the second supercharger (2) are each cooled by a cooling system separate from the engine.

10. An engine air intake system according to claim 1, characterised in that the volume of the second charge air cooler (4) is smaller than the volume of the first charge air cooler (3).