Intake high-efficiency mixing and stabilizing device suitable for EGR technology of agricultural diesel engine

Abstract

The application discloses a high-efficiency air intake mixing and stabilizing device suitable for an EGR technology of an agricultural diesel engine, which comprises a cylinder body, a gas chamber penetrating through two ends of the cylinder body, and an air inlet and an air outlet at the two ends of the cylinder body; two flow dispersing nets are installed at the air inlet of the cylinder body, and a plurality of grid holes arranged in rows and columns are arranged on the two flow dispersing nets; a connecting line of the centers of any row of grid holes on the first flow dispersing net arranged outside is a first grid hole arrangement line, a connecting line of the centers of any row of grid holes on the second flow dispersing net arranged inside is a second grid hole arrangement line, and the included angle between the first grid hole arrangement line and the second grid hole arrangement line is 0-45 degrees; and a flow sensor is installed at the middle part of the cylinder body. The high-efficiency air intake mixing and stabilizing device can solve the problems that the flow field in the pipeline changes due to the change of the engine air intake pipeline, the air intake flow sensor needs to be repeatedly calibrated, the flow sensor has low installation universality, and the installation and fixation have risks.

Description

Technical Field

[0001] This invention relates to the field of diesel engine technology, specifically to an intake air high-efficiency mixing and stabilizing device applicable to EGR technology in agricultural diesel engines. Background Technology

[0002] To meet the China IV emission standards for non-road vehicles, two main emission technology routes are currently available on the market: DOC+DPF+SCR and EGR+DOC+DPF. For diesel engines using the EGR+DOC+DPF route, the opening of the EGR valve is dynamically adjusted based on the actual intake air flow to achieve closed-loop control of the EGR rate. Therefore, the accuracy of the intake air flow test directly determines the accuracy of the EGR rate, which in turn directly affects whether the engine's emissions meet the China IV emission standards for non-road vehicles and whether the product can be marketed.

[0003] In off-road applications, particularly in the agricultural machinery industry, intake pipe layouts are diverse due to limitations in overall machine design and hood space. This leads to highly variable flow fields within the intake pipes, requiring calibration of the intake flow sensor for each type of pipe. This wastes testing resources and slows down the overall machine development process. Furthermore, the diverse pipe layouts demand greater versatility in flow sensor installation. Simultaneously, the harsh working environment of agricultural machinery presents a significant challenge to the safe and reliable installation and fixation of the sensor. Based on these practical needs, this invention provides an efficient air mixing and stabilization device suitable for EGR technology in agricultural diesel engines. Summary of the Invention

[0004] The purpose of this invention is to provide an efficient air mixing and stabilizing device suitable for EGR technology in agricultural diesel engines, in order to solve problems such as changes in the flow field within the engine intake pipeline due to variations in the engine intake pipeline, the need for repeated calibration of the intake flow sensor, the low universality of flow sensor installation, and the risks associated with installation and fixation.

[0005] To achieve the above objectives, the specific solution adopted by the present invention is as follows:

[0006] An efficient intake air mixing stabilization device suitable for EGR technology in agricultural diesel engines includes:

[0007] A cylindrical body having a gas chamber extending through both ends, with the two ends of the cylindrical body being an air inlet and an air outlet, respectively;

[0008] Two diffuser nets are installed at the air inlet of the cylinder. Each diffuser net has several grid holes arranged in rows and columns. The line connecting the centers of any row of grid holes on the outermost first diffuser net is the first grid hole line, and the line connecting the centers of any row of grid holes on the innermost second diffuser net is the second grid hole line. The included angle between the first grid hole line and the second grid hole line is 0-45°.

[0009] A flow sensor is installed in the middle of the cylinder to detect the flow rate of air in the gas chamber after it has been dispersed by the diffuser net.

[0010] Furthermore, a limiting ring is provided on the outer side of the cylinder at a distance of 25-50mm from both ends, and the outer diameter of the limiting ring is 8-10mm larger than the outer diameter of the cylinder.

[0011] Furthermore, a notch communicating with the gas chamber is provided in the middle of the cylinder for installing a sensor mounting assembly; the sensor mounting assembly includes a support frame protruding from the cylinder, the support frame being located between two limiting rings, the support frame having a sensor mounting hole in the middle for installing a flow sensor, and the top surface of the support frame having at least one anti-misalignment mounting boss, the flow sensor placed in the sensor mounting hole being detachably connected to the support frame by bolts.

[0012] Furthermore, a reinforcing rib of the same height as the two limiting rings is connected between them. The reinforcing rib is located on the cylinder and is symmetrically arranged with the support frame.

[0013] Furthermore, a pair of fixing components are symmetrically arranged on the cylinder between the two limiting rings with the sensor mounting assembly as the center. The fixing components include two cylindrical bosses with embedded metal threaded spacers. The two cylindrical bosses are respectively arranged near the limiting rings on the corresponding sides, and the two cylindrical bosses are connected by rectangular ribs.

[0014] Furthermore, a mounting ring groove is provided on the circumferential inner wall of the air inlet of the cylinder, and several positioning protrusions extending along the axis of the air inlet are provided on the inner wall of the mounting ring groove.

[0015] Furthermore, the first diffuser has a barrel-shaped structure, including a barrel bottom and a barrel wall. The barrel bottom, which is parallel to the second diffuser, is provided with several grid holes. The center distance between two adjacent grid holes is 6-8% of the inner diameter of the barrel inlet. The wall thickness of the barrel bottom is 0.8-1% of the inner diameter of the barrel inlet. The barrel wall is provided with several first grooves that cooperate with the positioning protrusions. The free end of the barrel wall abuts against the second diffuser. The length of the barrel wall is 8-10% of the inner diameter of the barrel inlet.

[0016] The barrel wall is provided with a limiting groove, and the side wall of the barrel is provided with a buckle mounting hole. The first diffuser can be positioned by using a fixing buckle to pass through the buckle mounting hole and abut against the limiting groove.

[0017] The distance from the bottom of the barrel to the sensor mounting hole is 25-28% of the inner diameter of the barrel's air inlet.

[0018] Furthermore, the second diffuser is in the shape of a circular plate, and the center distance between two adjacent grid holes in the second diffuser is 2-3% of the inner diameter of the cylinder inlet. The outer wall of the second diffuser is provided with a second groove that cooperates with the positioning protrusion. The second diffuser is installed in the mounting ring groove and abuts against the bottom wall of the mounting ring groove.

[0019] Furthermore, a ring of anti-detachment protrusions is provided on the outer surface of both the left and right ends of the cylinder.

[0020] Furthermore, the cylinder, limiting ring, sensor mounting assembly, reinforcing rib, fixing assembly, and anti-detachment protrusion are integrally formed.

[0021] Beneficial effects:

[0022] 1) This invention provides an intake air high-efficiency mixing and stabilizing device suitable for EGR technology of agricultural diesel engines, which has the following advantages: The invention sets a first diffuser and a second diffuser at the air inlet of the cylinder, which together with the inner wall of the cylinder in front of the flow sensor to form a diffuser cavity. The intake air of different pipeline forms is fully dispersed after passing through the diffuser cavity, and its flow velocity is evenly distributed on the cross-section of the cylinder. The flow sensor can accurately measure the air flow in the cylinder, which greatly reduces the calibration workload when matching the engine.

[0023] 2) This device has a simple structure, high applicability, good mixing effect, and low intake resistance loss to the engine. The outer wall of the cylinder is connected by a limiting ring, sensor mounting components, fixing components, and reinforcing ribs to form an integral frame structure to strengthen the cylinder and meet the harsh operating conditions of non-road machinery. Anti-detachment protrusions are provided at the ends of the air inlet and outlet to ensure that the device is firmly and reliably installed in the engine pipeline. The limiting ring provided by the device ensures accurate and reliable installation when connected to the pipeline. Fixing components are symmetrically arranged on both sides of the outer wall of the cylinder to meet the matching needs of various engines. Attached Figure Description

[0024] Figure 1 This is a front view of the intake high-efficiency mixing and stabilizing device of the present invention.

[0025] Figure 2 This is a cross-sectional view of the front view of the intake high-efficiency mixing and stabilizing device in this invention.

[0026] Figure 3This is a right view of the intake high-efficiency mixing and stabilizing device of the present invention.

[0027] Figure 4 This is a top view of the intake high-efficiency mixing and stabilizing device of the present invention.

[0028] Figure 5 This is a bottom view of the intake high-efficiency mixing and stabilizing device of the present invention.

[0029] Figure 6 This is a front view of the first diffuser net of the present invention.

[0030] Figure 7 This is a front view of the second diffuser net of the present invention.

[0031] The markings in the diagram are: 1. Cylinder body, 2. Fixing buckle, 3. First diffuser mesh, 301. Limiting groove, 302. First groove, 4. Second diffuser mesh, 401. Second groove, 5. Gas chamber, 6. Air inlet, 7. Air outlet, 8. Buckle mounting hole, 9. Mounting ring groove, 10. Anti-detachment protrusion, 11. Limiting ring, 12. Sensor mounting assembly, 121. Support frame, 122. Anti-misalignment mounting boss, 123. Direction guide mark, 124. Threaded hole, 13. Fixing assembly, 131. Cylindrical boss, 132. Rectangular rib, 14. Reinforcing rib, 15. Positioning protrusion. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0033] like Figure 1-7 As shown, the intake air high-efficiency mixing and stabilizing device suitable for EGR technology of agricultural diesel engines includes a cylinder 1. The cylinder 1 has a gas chamber 5 extending through both ends. The two ends of the cylinder 1 are an air inlet 6 and an air outlet 7, respectively. A first diffuser 3 and a second diffuser 4 are installed at the air inlet 6 of the cylinder 1. Let the line connecting the centers of any row of grille holes on the outermost first diffuser 3 be the first grille hole line, and the line connecting the centers of any row of grille holes on the innermost second diffuser 4 be the second grille hole line. The angle between the first and second grille hole lines is 0-45°. A flow sensor (not shown in the figure) is installed in the middle of the cylinder 1 to detect the air flow rate in the gas chamber after being diffused by the diffuser nets. The air entering the cylinder 1 through the air inlet 6 undergoes initial segmentation and breakage by the first diffuser 3, and further breakage and mixing by the second diffuser 4 to form a uniform flow field. The flow sensor, located within this uniform flow field, can accurately measure the air flow rate within the intake cylinder.

[0034] It should be noted that the angle between the first and second grid hole arrays in this invention is limited to 0-45°. Specifically, when the intake flow rate is below 700 kg / h, a 0° angle provides better dispersion and mixing; when the intake flow rate is above 700 kg / h, a 45° angle provides even better dispersion and mixing. At low flow rates, the gas velocity is relatively slow, and the turbulence is relatively low, resulting in better uniformity of the dispersed flow field from the parallel grids. As the flow rate increases, the gas velocity and turbulence in the pipe increase. A 45° angle effectively further divides the airflow passing through the first grid along its streamlines, resulting in better dispersion and mixing. Since the diesel engines used in this invention are mostly in operation below 700 kg / h, a 0° angle is preferred.

[0035] Limiting rings 11 are provided on the outer surface of the cylinder 1 at distances of 25-50mm from both ends. The outer diameter of the limiting rings 11 is 8-10mm larger than the outer diameter of the cylinder 1. The cylinder 1 and the limiting rings 11 are integrally formed, and the connection between the limiting rings 11 and the cylinder 1 is smoothly transitioned. The presence of the limiting rings 11 allows for precise control of the length of the device inserted into the pipeline during installation, resulting in a scientific and reasonable pipeline layout with high consistency with the pipeline design. This solves the long-standing problem in flexible hose pipeline design where the actual assembly state of the pipeline does not match the design state, leading to messy pipelines and interference not present in the design. The limiting rings 11 divide the cylinder 1 into three parts: the air inlet section, the intermediate section, and the air outlet section.

[0036] The inner wall of the air inlet section of the cylinder 1 is provided with a ring groove 9, and the inner wall of the ring groove 9 is provided with a number of positioning protrusions 15 extending along the axis of the air inlet 6.

[0037] The specific structure of the first diffuser 3 is described below. The first diffuser 3 has a barrel-shaped structure, including a barrel bottom and a barrel wall. The barrel bottom, which is parallel to the second diffuser 4, is provided with several grid holes. The center distance between two adjacent grid holes is 6-8% of the inner diameter of the air inlet section of the cylinder 1. The wall thickness of the barrel bottom is 0.8-1% of the inner diameter of the air inlet of the cylinder 1. The barrel wall is provided with several first grooves 302 that cooperate with the positioning protrusions 15. The free end of the barrel wall abuts against the second diffuser 4. The length of the barrel wall is 8-10% of the inner diameter of the air inlet of the cylinder 1. The barrel wall is provided with a limiting groove 301. The circumferential side wall of the air inlet section of the cylinder 1 is provided with at least one snap-fit ​​mounting hole 8. The first diffuser 3 can be positioned by using a fixing buckle 2 passing through the snap-fit ​​mounting hole 8 and abutting against the limiting groove 301. This invention, by limiting the wall thickness at the bottom of the first diffuser mesh 3, the length of the barrel wall, and the center distance between two adjacent grid holes, can, on the one hand, reduce the size of the barrel, which is beneficial for better application matching; on the other hand, this grid spacing can achieve the desired diffuser mixing effect while meeting the resistance requirements. Specifically, the denser the grid, the better the diffuser mixing effect, but the greater the resistance will be. The data selected in this invention achieves a balance between diffuser and resistance values.

[0038] The present invention uses a fixing buckle 2 on the cylinder 1 to cooperate with the buckle mounting hole 8 and the limiting groove 301 to position the first diffuser net 3. Compared with the existing solution of fixing with glue, it avoids the problem of the glue falling into the engine combustion chamber and aggravating the engine combustion when it falls off. On the other hand, the buckle installation is more reliable and solves the problem of fixing failure caused by long-term vibration of the whole machine due to glue fixing.

[0039] Next, the specific structure of the second diffuser 4 will be described in detail. The second diffuser 4 is in the shape of a circular plate. The center distance between two adjacent grid holes in the second diffuser 4 is 2-3% of the inner diameter of the air inlet of the cylinder 1. The outer wall of the second diffuser 4 is provided with a second groove 401 that cooperates with the positioning protrusion 15. The second diffuser 4 is installed in the mounting ring groove 9 and abuts against the bottom wall of the mounting ring groove 9. Of course, the second diffuser 4 can also be directly fixed in the cylinder 1 during the production of the cylinder 1.

[0040] The flow sensor is mounted on the middle section of the cylinder 1 via a sensor mounting assembly 12. The specific structure of the sensor mounting assembly 12 is described below. The middle section of the cylinder 1 has a notch communicating with the gas chamber 5 for mounting the sensor mounting assembly 12. The sensor mounting assembly 12 includes a support frame 121 protruding from the cylinder, positioned between two limiting rings 11. The support frame 121 has a sensor mounting hole in its center for mounting the flow sensor, which communicates with the interior of the gas chamber 5. The upper surface of the support frame 121 has at least one anti-misalignment mounting boss 122 and two threaded holes 124. The side surface of the support frame has a direction indicator 123. The flow sensor, placed in the sensor mounting hole, is detachably connected to the support frame 121 via bolts that mate with the threaded holes 124.

[0041] Furthermore, the support frame 121 is integrally formed with the cylinder 1, and the connection between the support frame 121 and the cylinder 1 is smoothly transitioned. The support frame 121 adopts a conformal design, and the overall structure is scientific and reasonable, ensuring the environmental requirements for the reliable operation of the flow sensor. The error-proof mounting boss 122 and the direction guide mark 123 guide the assembly process of this device, improve the assemblability of this device, and reduce the skill requirements for the assembler.

[0042] The distance between the sensor mounting hole on the support frame 121 and the bottom of the first diffuser net 3 is 25-28% of the inner diameter of the air inlet of the cylinder 1. After passing through the first and second diffuser nets, the flow field is relatively stable. The flow field at the installation position of the flow sensor of the present invention is not affected by the changes in the front-end air inlet pipe, and can represent the flow field state of the rectification section.

[0043] In a preferred embodiment of the present invention, a reinforcing rib 14 of the same height as the limiting rings 11 is connected between the two limiting rings 11. The reinforcing rib 14 is disposed on the cylinder 1 and symmetrically arranged with the support frame 121. The reinforcing rib 14 improves the structural strength of the device and strengthens the production mold, reducing the defect rate. At the same time, the height of the reinforcing rib 14 is consistent with the height of the limiting rings 11, which is a reasonable structural arrangement and facilitates part forming and demolding.

[0044] In a preferred embodiment of the present invention, a pair of fixing components 13 are symmetrically arranged on the cylinder 1 between the two limiting rings 11, with the sensor mounting assembly 12 as the center. Each fixing component 13 includes two cylindrical bosses 131 with embedded metal threaded spacers. The two cylindrical bosses 131 are respectively positioned adjacent to the corresponding limiting rings 11 and are connected by rectangular ribs 132. The symmetrically arranged fixing components 13 improve the adaptability of the device to different usage scenarios and enhance the product's versatility.

[0045] Furthermore, the limiting ring 11, sensor mounting assembly 12, fixing assembly 13 and reinforcing rib 14 are connected to form a U-shaped frame structure. This frame structure greatly enhances the strength of the cylinder, enabling the device to operate safely and reliably in harsh agricultural application environments.

[0046] As a preferred embodiment of the present invention, a ring of anti-detachment protrusions 10 is provided on the outer surface of both the left and right ends of the cylinder 1. The cross-section of the anti-detachment protrusions 10 is triangular, and the maximum outer diameter of the anti-detachment protrusions 10 is 1-3 mm larger than the outer diameter of the cylinder 1. The outer periphery of the anti-detachment protrusions 10 is a smooth curved surface, and the connection with the cylinder is smoothly transitioned. The presence of the anti-detachment protrusions 10 not only facilitates the assembly of the device during installation, but also ensures the connection strength with the connecting pipeline during the operation of the whole machine, thereby improving the reliability of the pipeline sealing.

[0047] Preferably, the cylinder 1, the anti-detachment protrusion 10, the limiting ring 11, the sensor mounting assembly 12, the fixing assembly 13, and the reinforcing rib 14 are all integrally formed, with a simple structure, reliable strength, and high degree of integration.

[0048] Preferably, both the cylinder 1 and the first diffuser mesh 3 are injection molded. The material forming the grid holes in the second diffuser mesh 4 is stainless steel to prevent the steel wires from rusting due to moisture in the air, which could then fall into the turbocharger and damage the turbocharger impeller.

[0049] The working principle of the intake air high-efficiency mixing and stabilizing device for EGR technology of agricultural diesel engines provided by this invention is as follows: Under normal engine operating conditions, the airflow in the intake pipe is generally in a turbulent state. Under this state, the flow field distribution in the pipe cross section is greatly affected by the pipe routing and layout. The intake air mixing and stabilizing device disperses and mixes the intake air twice through the first diffuser 3 and the second diffuser 4, so that the flow velocity of the intake air in the cross section 1 of the cylinder is evenly distributed, reducing the impact of changes in pipe layout on the flow field. The flow sensor can accurately measure the air flow rate of different pipe layouts. At the same time, through the scientific and reasonable modular and functional design of each unit on the cylinder 1, the problems of low installation versatility of flow sensor and the risk of installation fixation are solved.

[0050] Tests conducted on a flow test bench revealed that the diffused air intake mixing and stabilizing device provided by this invention can adapt to different pipeline layouts and accurately measure the intake flow rate.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention in any way. All equivalent transformations or modifications made in accordance with the essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An intake air high-efficiency mixing stabilizing device suitable for EGR technology in agricultural diesel engines, characterized in that, include: A cylindrical body has a gas chamber that extends through both ends, with the two ends of the cylindrical body being an air inlet and an air outlet, respectively; a limiting ring is provided on the outer surface of the cylindrical body at a distance of 25-50mm from each end, and the outer diameter of the limiting ring is 8-10mm larger than the outer diameter of the cylindrical body. Two diffuser nets are installed at the air inlet of the cylinder. Each diffuser net has several grid holes arranged in rows and columns. The line connecting the centers of any row of grid holes on the outermost first diffuser net is the first grid hole line, and the line connecting the centers of any row of grid holes on the innermost second diffuser net is the second grid hole line. The included angle between the first grid hole line and the second grid hole line is 0-45°. A flow sensor, installed in the middle of the cylinder, is used to detect the flow rate of air in the gas chamber after it has been dispersed by the diffuser net. The cylinder has a notch in the middle that communicates with the gas chamber for installing a sensor mounting assembly. The sensor mounting assembly includes a support frame that protrudes from the cylinder and is located between two limiting rings. The support frame has a sensor mounting hole in the middle for installing a flow sensor and at least one anti-misalignment mounting boss on the top surface of the support frame. The flow sensor placed in the sensor mounting hole is detachably connected to the support frame by bolts. The first diffuser has a barrel-shaped structure, including a barrel bottom and a barrel wall. The barrel bottom, which is parallel to the second diffuser, has several grid holes. The center distance between two adjacent grid holes is 6-8% of the inner diameter of the barrel's air inlet. The wall thickness of the barrel bottom is 0.8-1% of the inner diameter of the barrel's air inlet. The barrel wall has several first grooves that cooperate with positioning protrusions. The free end of the barrel wall abuts against the second diffuser. The length of the barrel wall is 8-10% of the inner diameter of the barrel's air inlet. The barrel wall is provided with a limiting groove, and the side wall of the barrel is provided with a buckle mounting hole. The first diffuser can be positioned by using a fixing buckle to pass through the buckle mounting hole and abut against the limiting groove. The distance from the bottom of the barrel to the sensor mounting hole is 25-28% of the inner diameter of the barrel's air inlet.

2. The intake air high-efficiency mixing stabilizing device for EGR technology of agricultural diesel engines according to claim 1, characterized in that, A reinforcing rib of the same height as the two limiting rings is connected between them. The reinforcing rib is located on the cylinder and is symmetrically arranged with the support frame.

3. The intake air high-efficiency mixing stabilizing device suitable for EGR technology of agricultural diesel engines according to claim 2, characterized in that, On the cylinder, a pair of fixing components are symmetrically arranged between the two limiting rings with the sensor mounting assembly as the center. The fixing components include two cylindrical bosses with embedded metal threaded spacers. The two cylindrical bosses are respectively located near the limiting rings on the corresponding sides, and the two cylindrical bosses are connected by rectangular ribs.

4. The intake air high-efficiency mixing stabilizing device for EGR technology of agricultural diesel engines according to claim 1, characterized in that, The cylinder has a mounting groove on its inner circumferential wall at the air inlet, and several positioning protrusions extending along the axis of the air inlet are provided on the inner wall of the mounting groove.

5. The intake air high-efficiency mixing stabilizing device for EGR technology of agricultural diesel engines according to claim 4, characterized in that, The second diffuser is in the shape of a circular plate. The center distance between two adjacent grid holes in the second diffuser is 2-3% of the inner diameter of the cylinder inlet. The outer wall of the second diffuser is provided with a second groove that cooperates with the positioning protrusion. The second diffuser is installed in the mounting ring groove and abuts against the bottom wall of the mounting ring groove.

6. The intake air high-efficiency mixing stabilizing device for EGR technology of agricultural diesel engines according to claim 3, characterized in that, A ring of anti-detachment protrusions is provided on the outer surface of both the left and right ends of the cylinder.

7. The intake air high-efficiency mixing stabilizing device for EGR technology of agricultural diesel engines according to claim 6, characterized in that, The cylinder, limiting ring, sensor mounting assembly, reinforcing rib, fixing assembly, and anti-detachment protrusion are integrally formed.

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