Intake system of engine and vehicle

Abstract

The application provides an engine air intake system and a vehicle, the engine air intake system comprising a carrier, an air filter arranged in the carrier, an air inlet and an air outlet arranged on both sides of the carrier, a gas conveying pipe communicated with the air outlet, and a hot film air flow sensor arranged in the gas conveying pipe, wherein the air filter is located on an air flow path between the air inlet and the air outlet, and an axial length of the hot film air flow sensor from the air outlet is greater than an inner diameter of the gas conveying pipe, so that engine bench calibration air intake system model consistency scattering is controlled within a range of ±5%, the flow field uniformity and stability at the HFM sensor can be ensured in a pulse air flow environment of an engine bench, the interference of the pulse air flow on the HFM signal is reduced, the test result under an actual working condition (pulse air flow) is consistent with the design target, and thus the dependence on the test result of a flow sensor bench (stable air flow) is reduced.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to an engine intake system and a vehicle. Background Technology

[0002] When the engine is running normally, the fresh air intake flow rate is a core parameter in the calibration and control process. It is detected by the HFM (hot film air flow meter) sensor in the intake system and the signal is transmitted to the ECU. Based on this flow signal, the ECU participates in the calculation of fresh air intake flow rate, RGR rate, fuel quantity correction and smoke limit, and then controls the opening and response of actuators such as EGR valve and TVA valve, which directly affects the key performance of the engine and the vehicle, such as emissions, fuel consumption and thermal management.

[0003] The structure and working principle of HFM are as follows: It consists of a Wheatstone bridge circuit composed of a metal hot film, a thermistor element, etc., integrated on a ceramic substrate. The ECU maintains the bridge balance by controlling the current to heat the hot film. When air flows through the sensor, it carries away some heat, causing the resistance of the hot film to decrease, which makes the bridge unbalanced. The ECU then increases the hot film current to keep its temperature constant, and finally calculates the intake air volume based on the current change (the hot film current is a function of the air mass flow rate).

[0004] Based on the above principles, the accuracy of HFM testing is closely related to gas velocity, flow field uniformity, and flow field direction. Therefore, the intake system design must ensure consistency in gas velocity, flow field uniformity, and direction under the same flow rate to control HFM signal dispersion within acceptable limits. Excessive deviation will directly affect engine and vehicle emissions, fuel consumption, and thermal management performance. With increasingly stringent emission and fuel consumption regulations both domestically and internationally, the impact of intake model dispersion on emission consistency and fuel consumption is becoming increasingly significant. Therefore, it is necessary to control such dispersion through optimized intake system hardware design.

[0005] The drawbacks of existing technologies are that the intake system flow sensor bench test uses a stable airflow, while the airflow on the engine bench differs significantly from the actual operating conditions due to the superposition of engine pulse airflow. As a result, the flow sensor bench test results can only be used as a reference, and the final results must be based on the actual test results of the engine bench, which increases the complexity of development and verification. Summary of the Invention

[0006] Therefore, the purpose of this invention is to provide an intake system for an engine to solve the problems described in the background.

[0007] On one hand, the invention provides the following technical solution: an engine intake system, including a carrier, an air filter disposed within the carrier, an air inlet and an air outlet disposed on both sides of the carrier, an air supply pipe connected to the air outlet, and a hot-film air flow sensor disposed within the air supply pipe, wherein the air filter is located on the airflow path between the air inlet and the air outlet, and the axial length of the hot-film air flow sensor from the air outlet is greater than the inner diameter of the air supply pipe, so that the consistency variance of the engine bench calibration intake system model is controlled within ±5%.

[0008] Compared to existing technologies, the advantages of this application are as follows: by setting the axial distance between the hot-film air flow sensor (HFM) and the air outlet to be greater than the inner diameter of the air delivery pipe, the consistency variance of the intake system model calibrated on the engine bench can be controlled within ±5%. This structural design can ensure the uniformity and stability of the flow field at the HFM sensor under the pulsed airflow environment of the engine bench, reduce the interference of pulsed airflow on the HFM signal, and make the test results under actual operating conditions (pulsed airflow) consistent with the design target, thereby reducing the dependence on the test results of the flow sensor bench (stable airflow).

[0009] Furthermore, when the air filter is a flat plate structure air filter, the air supply pipe includes an upstream horn pipe, an upstream straight pipe, a downstream straight pipe, a downstream curved pipe, and a collecting pipe connected in sequence, wherein the hot film air flow sensor is installed at the connection between the upstream straight pipe and the downstream straight pipe.

[0010] Furthermore, the parameters of each branch of the gas transmission pipeline satisfy at least one of the following conditions:

[0011] The cross-sectional area of ​​the upstream straight pipeline remains constant along the airflow direction;

[0012] The length LH of the upstream straight pipeline satisfies LH>1d;

[0013] The central angle α of the downstream curved pipeline satisfies α < 30°;

[0014] The radius re of the flare opening of the upstream flare pipe satisfies 0.05d ≤ re ≤ 0.15d;

[0015] The vertical distance LF between the upstream straight pipeline and the flat plate structure air filter satisfies LF>0.5d;

[0016] The horizontal distance Lo between the air outlet and the outer wall of the carrier satisfies Lo <LA / 4;

[0017] The length L of the downstream straight pipeline satisfies L>1d;

[0018] The radius of curvature rb of the downstream curved pipeline satisfies rb>1.5d;

[0019] The minimum distance between the downstream curved pipe and the crankcase ventilation pipe interface is greater than 350mm;

[0020] The filter paper folding variance of the flat plate structure air filter is ≤±2%, and the corresponding model consistency variance is ≤±3%.

[0021] Where LA is the length of the flat plate air filter and d is the inner diameter of the air delivery pipe.

[0022] Furthermore, the cross-section of the upstream straight pipe is configured as a flared structure that gradually narrows along the airflow direction.

[0023] Furthermore, when the air filter is a cylindrical air filter, the axial length L1 of the hot-film air flow sensor from the air outlet satisfies L1>2.5D1, and its corresponding model consistency variance is ≤±5%, where D1 is the inner diameter of the air supply pipe near the air outlet end.

[0024] Furthermore, the air outlet of the cylindrical air filter is equipped with a flow-stabilizing grille.

[0025] Furthermore, the filter element of the cylindrical air filter is a honeycomb filter element, which includes alternating stacked corrugated paper layers and flat paper layers. The corrugated paper layers and flat paper layers are bonded together with epoxy resin to form a multi-layer filter cavity. The inlet end of each filter cavity is open, and the outlet end of each filter cavity is closed, forcing the airflow to penetrate the filter material and enter the adjacent filter cavity.

[0026] Furthermore, the corrugated paper layer has a peak height H = 25 mm, a wavelength spacing P = 38 mm, and the filter cavity openings of adjacent filter layers are arranged orthogonally.

[0027] Furthermore, the honeycomb filter element is configured to have a uniformity variance of ≤±3%.

[0028] Secondly, the invention provides the following technical solution: a vehicle, including an engine and the aforementioned engine intake system. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the air intake system of the flat plate air filter of the present invention;

[0030] Figure 2 This is a line graph showing the consistency variation test of the flat plate structure air filter intake system of the present invention.

[0031] Figure 3 This is a schematic diagram of the cylindrical air filter intake system of the present invention;

[0032] Figure 4This is a schematic diagram of the structure of the cylindrical air filter intake system of the present invention on the outlet side;

[0033] Figure 5 This is a schematic diagram illustrating the working principle of the honeycomb filter element of the present invention;

[0034] Figure 6 This is a line graph showing the consistency difference between the conventional cylindrical air filter and honeycomb filter structures of this invention under engine bench model calibration.

[0035] Figure 7 This is a schematic diagram of the internal flow field streamline analysis of the honeycomb filter of the present invention;

[0036] Figure 8 This is a schematic diagram of the internal flow field streamline analysis of a traditional cylindrical air filter.

[0037] Explanation of main component symbols: 1. Carrier; 2. Air filter; 3. Air inlet; 4. Air outlet; 5. Air delivery pipe; 6. Hot film air flow sensor; 7. Upstream horn pipe; 8. Upstream straight pipe; 9. Downstream straight pipe; 10. Downstream curved pipe; 11. Combining pipe; 12. Flow stabilizer; 13. Filter chamber. Detailed Implementation

[0038] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0039] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] Example 1

[0042] The air intake system of a flat-plate air filter; specifically designed for the air intake systems of flat-plate air filters used in SUVs, PKs, and light commercial vehicles.

[0043] Please see Figures 1 to 2 The image shows an engine intake system according to Embodiment 1 of the present invention, including a carrier 1, an air filter 2 disposed within the carrier 1, an air inlet 3 and an air outlet 4 disposed on both sides of the carrier 1, an air supply pipe 5 connected to the air outlet 4, and a hot-film air flow sensor 6 disposed within the air supply pipe 5. The air filter 2 is located on the airflow path between the air inlet 3 and the air outlet 4, and the axial length of the hot-film air flow sensor 6 from the air outlet 4 is greater than the inner diameter of the air supply pipe 5, so that the consistency variance of the engine bench calibration intake system model is controlled within ±5%.

[0044] In this embodiment, the carrier 1 is a hollow shell with an air inlet 3 and an air outlet 4 at both ends, and a flat plate air filter is installed inside.

[0045] The air supply pipe 5 connects to the air outlet 4 and includes, in sequence, an upstream horn pipe 7, an upstream straight pipe 8, a downstream straight pipe 9, a downstream curved pipe 10, and a collecting pipe 11. The HFM air flow sensor is installed between the upstream straight pipe 8 and the downstream straight pipe 9, and the distance L from it to the air outlet 4 is greater than the inner diameter d of the air supply pipe 5.

[0046] Key parameter control:

[0047] The axial length of HFM from air outlet 4 is greater than the inner diameter of air pipe 5, ensuring that the consistency variance of the intake system model in engine bench calibration is controlled within ±5%.

[0048] Upstream straight pipe 8: The cross-section has no expansion or variation, allowing for a "large to small" flared opening. The flared opening radius re = 0.05d to 0.15d, preferably re ≈ 0.1d (the R angle of the flared opening of the air filter before air filter 2). The length LH > 1d (d is the inner diameter of the pipe) to ensure that the airflow is stable before entering the HFM sensor.

[0049] Downstream curved pipe 10: central angle α < 30°, radius rb > 1.5d, to reduce the impact of airflow direction on the HFM sensor.

[0050] Spatial layout: The vertical distance LF between the upstream straight pipe 8 and the flat plate air filter is greater than 0.5d to avoid the filter element interfering with airflow. The horizontal distance Lo between the air outlet 4 and the outer wall of the carrier 1 is less than LA / 4 (LA is the length of the flat plate air filter) to optimize the airflow path.

[0051] Filter element characteristics: The filter element fold variation of the flat plate air filter is ≤±2%, ensuring uniform filtration efficiency.

[0052] Implementation Results: Through the above parameter optimization, the intake system of the flat plate structure air filter can control the consistency variance of the intake system model calibrated on the engine bench within ±3%.

[0053] Example 2

[0054] An intake system with a cylindrical air filter structure;

[0055] I. Applicable Scenarios;

[0056] Due to space constraints, light and heavy trucks often use cylindrical or elliptical air filters for their intake systems. Traditional cylindrical air filters suffer from problems such as turbulent airflow and non-uniform filter material pores, resulting in uncontrollable flow fields at the HFM sensor. This leads to excessive variance in intake model calibration consistency, and the flow field cannot be controlled through bench testing or hardware characteristics. Therefore, structural optimization is necessary to address these issues in the early design stages.

[0057] II. Specific Structure and Optimization Scheme;

[0058] 1. The intake system of a traditional cylindrical air filter;

[0059] Please see Figures 3 to 8 The diagram illustrates an engine intake system according to Embodiment 2 of the present invention, comprising a carrier 1 (hollow housing), a cylindrical air filter (air filter 2), an air inlet 3, an air outlet 4, an air delivery pipe 5, and an HFM sensor. The cylindrical air filter is located in the airflow path between the air inlet 3 and the air outlet 4. The air delivery pipe 5 connects to the air outlet 4. The HFM sensor is installed inside the air delivery pipe 5, and its axial distance from the air outlet 4 is greater than the inner diameter of the air delivery pipe 5, ensuring that the consistency variance of the engine bench calibration intake system model is controlled within ±5%.

[0060] To improve the flow field stability at the HFM sensor, two optimization schemes are adopted:

[0061] Option 1: Extend the straight length of the upstream air supply pipe 5 of HFM, requiring L1 > 2.5D1 (L1: axial length of the hot-film air flow sensor from the air outlet, D1 is the inner diameter of the upstream air supply pipe 5 of HFM), and stabilize the airflow by increasing the straight pipe section;

[0062] Option 2: Design a flow-stabilizing grille 12 (such as a honeycomb or perforated plate structure) at the air outlet of air filter 2 to forcibly tidy up the turbulent airflow.

[0063] Implementation results: Through the above structural optimization, the consistency variance of the engine bench calibration intake system model can be controlled within ±5%.

[0064] 2. Air intake system of honeycomb filter element cylindrical structure air filter;

[0065] Applicable scenarios: When there is insufficient space for arrangement, the upstream of HFM cannot meet the straight pipe length requirements, or the outlet flow stabilizing grille 12 still cannot guarantee the flow field stability, a honeycomb filter structure air filter is adopted to fundamentally solve the internal turbulence problem of traditional cylindrical air filter 2.

[0066] Structure and Working Principle: Filter Cartridge Design: The honeycomb filter cartridge (also known as a straight-through filter cartridge) is made of corrugated paper and flat paper bonded together to form a filter layer. The channel (filter chamber 13) inside the filter layer is sealed at one end and open at the other end; Airflow Path: Outside air enters from the open end at the bottom of the filter cartridge. Because the other end of the channel (filter chamber 13) is sealed, it is forced to pass through the filter material into the adjacent channel, which not only achieves filtration, but also plays a role in stabilizing the flow through the "straight in and straight out" channel design (the entire filter cartridge is equivalent to a huge flow stabilizer, which can sort out the turbulent airflow in the lower shell).

[0067] Among them, the parameters of the gas supply pipe 5 are consistent with those of the traditional cylindrical air filter, that is, the straight length L1 of the upstream gas supply pipe 5 of HFM is greater than 2.5D1, which ensures the stability of airflow in pulse environment.

[0068] Implementation results: Through engine bench testing (such as a JMC light truck project), the consistency deviation of the intake model calibration of the honeycomb filter structure air filter can be reduced from ±4% of the traditional cylindrical structure to ±1%, and the overall deviation is controlled within ±3%.

[0069] In summary, the engine intake system of the above embodiments of the present invention has the following beneficial effects:

[0070] 1. Precisely control the consistency variance in intake model calibration:

[0071] By limiting the distance between HFM and air outlet 4 to be greater than the inner diameter of air supply pipe 5, the dispersion is ensured to be controlled within ±5%.

[0072] Optimize the piping parameters of the flat plate air filter (such as upstream straight pipe length LH>1d, downstream bend radius rb>1.5d, etc.) to further control the dispersion within ±3%.

[0073] By extending the upstream straight pipe of the traditional cylindrical air filter (L1>2.5D1) and designing the flow stabilizing grid 12, the dispersion is controlled within ±5%.

[0074] The honeycomb filter structure (with one end of the channel sealed and the other end open) fundamentally solves the turbulence problem, keeping the dispersion within ±3% and meeting the accuracy requirements of different scenarios.

[0075] 2. Ensure the stability of core engine and vehicle performance:

[0076] By optimizing the flow field uniformity at the HFM (such as the pipeline layout of the flat air filter and the flow stabilization design of the honeycomb filter element), the accuracy of the HFM signal is ensured, providing a reliable basis for the ECU to calculate the intake air flow, RGR rate and control actuators such as the EGR valve and TVA valve, directly improving the engine emission compliance rate, reducing fuel consumption and optimizing thermal management to meet stringent regulatory requirements.

[0077] 3. Provide clear structural design specifications to reduce development costs:

[0078] The key parameters of different air filter structures were clarified (such as the flared corner radius of the flat plate air filter re = 0.05d~0.15d, and L1>2.5D1 of the cylindrical air filter), providing engineers with design standards that can be directly implemented, avoiding repeated development and verification due to lack of specifications, shortening the development cycle, and reducing time and economic costs.

[0079] 4. Targeted solutions to the pain points of traditional structures, improving the universality of the technology:

[0080] To address the issue of uncontrollable flow field in traditional cylindrical air filters, the upstream straight pipe extension, the design of the flow stabilizing grid 12, and the innovative structure of the honeycomb filter element achieve controllable flow field from a hardware perspective, overcoming the difficulty of "flow field cannot be controlled by hardware characteristics" in existing technologies.

[0081] The solution covers both flat panel structures (suitable for SUVs and light commercial vehicles) and cylindrical structures (suitable for light and heavy trucks). In particular, the honeycomb filter element can still guarantee its effectiveness under conditions of demanding layout space or multi-platform universality requirements, thus improving the technology's adaptability to various scenarios.

[0082] In summary, the intake system structure defined in the claims achieves multiple beneficial effects, including dispersion control, performance assurance, cost optimization, and scenario adaptation, through precise parameter design and innovative filter structure.

[0083] Another embodiment of the present invention provides a vehicle including an engine and the above-described engine intake system.

[0084] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0085] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An intake system for an engine, characterized in that, The system includes a carrier, an air filter disposed within the carrier, an air inlet and an air outlet disposed on both sides of the carrier, an air supply pipe connected to the air outlet, and a hot-film air flow sensor disposed within the air supply pipe. The air filter is located on the airflow path between the air inlet and the air outlet, and the axial length of the hot-film air flow sensor from the air outlet is greater than the inner diameter of the air supply pipe, so that the consistency variance of the intake system model in engine bench calibration is controlled within ±5%. When the air filter is a flat plate structure air filter, the air supply pipe includes an upstream horn pipe, an upstream straight pipe, a downstream straight pipe, a downstream curved pipe and a collecting pipe connected in sequence, wherein the hot film air flow sensor is installed at the connection between the upstream straight pipe and the downstream straight pipe. The parameters of each branch of the gas transmission pipeline meet at least one of the following conditions: The cross-sectional area of ​​the upstream straight pipeline remains constant along the airflow direction; The length LH of the upstream straight pipeline satisfies LH>1d; The central angle α of the downstream curved pipeline satisfies α < 30°; The radius re of the flare opening of the upstream flare pipe satisfies 0.05d ≤ re ≤ 0.15d; The vertical distance LF between the upstream straight pipeline and the flat plate structure air filter satisfies LF>0.5d; The horizontal distance Lo between the air outlet and the outer wall of the carrier satisfies Lo <LA / 4; The length L of the downstream straight pipeline satisfies L>1d; The radius of curvature rb of the downstream curved pipeline satisfies rb>1.5d; The minimum distance between the downstream curved pipe and the crankcase ventilation pipe interface is greater than 350mm; The filter paper folding variance of the flat plate air filter is ≤±2%, and the corresponding model consistency variance is ≤±3%. Where LA is the length of the flat plate air filter and d is the inner diameter of the air delivery pipe.

2. The intake system of the engine according to claim 1, characterized in that, The cross-section of the upstream straight pipe is configured as a flared structure that gradually narrows along the airflow direction.

3. The intake system of the engine according to claim 1, characterized in that, When the air filter is a cylindrical air filter, the axial length L1 of the hot film air flow sensor from the air outlet satisfies L1>2.5D1, and its corresponding model consistency variance is ≤±5%, where D1 is the inner diameter of the air supply pipe near the air outlet end.

4. The intake system of the engine according to claim 3, characterized in that, The air outlet of the cylindrical air filter is equipped with a flow-stabilizing grille.

5. The intake system of the engine according to claim 3, characterized in that, The filter element of the cylindrical air filter is a honeycomb filter element, which includes alternating stacked corrugated paper layers and flat paper layers. The corrugated paper layers and flat paper layers are bonded together with epoxy resin to form a multi-layer filter cavity. The inlet end of each filter cavity is open, and the outlet end of each filter cavity is closed, forcing the airflow to penetrate the filter material and enter the adjacent filter cavity.

6. The intake system of the engine according to claim 5, characterized in that, The corrugated paper layer has a peak height H=25mm, a wavelength spacing P=38mm, and the filter cavity openings of adjacent filter layers are arranged orthogonally.

7. The intake system of the engine according to claim 5, characterized in that, The honeycomb filter element is configured to achieve a uniformity variance of ≤±3%.

8. A vehicle, comprising an engine, characterized in that: An intake system is installed for an engine as described in any one of claims 1-7.

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