Self-lubricating exhaust gas recirculation valve

Abstract

The utility model relates to exhaust gas recirculation valve technical field, especially in kind of self -lubricating exhaust gas recirculation valve, including valve seat, valve core, valve stem subassembly and electric control assembly, the air inlet channel and the air outlet channel that are mutually connected are equipped in valve seat, the valve core is placed in the air inlet channel and is equipped with the valve hole for the exhaust gas to enter, the valve stem subassembly includes the valve stem of the valve core, axle sleeve, valve piece, the electric control assembly drives the valve piece rotation to change the effective flow area of valve hole to realize the opening and closing of valve, the oil storage channel that stores lubricating oil is equipped in the valve stem along the axis, one end of oil storage channel is located in the valve stem, the other end orifice sets up in the end face of valve stem, the orifice is equipped with the plug of detachable connection with it, the periphery of valve stem is evenly distributed with several X -shaped grooves, the X -shaped groove is evenly distributed with several lubricating holes along the radial setting of valve stem, lubricating hole is linked together with oil storage channel, the utility model has the beneficial effects that: realize long -term self -lubricating.

Description

Technical Field

[0001] This utility model relates to the technical field of waste gas recirculation valves, specifically to a self-lubricating waste gas recirculation valve. Background Technology

[0002] Exhaust gas recirculation (EGR) is widely used in various diesel and gasoline engines. It is mainly used to precisely regulate the amount of exhaust gas returning to the intake system in order to reduce combustion temperature and reduce nitrogen oxide emissions.

[0003] Patent application number 201210542381.7 discloses a rotary EGR valve, including a valve body with an air inlet and an exhaust port, a transmission reduction mechanism between a motor and a driven gear, and a valve stem installed inside the driven gear; the valve body has a valve port, which is controlled by the rotation of the valve stem; a return spring is provided between the valve stem and the valve body; the valve port includes a valve disc and a valve seat, the lower surface of the valve seat and the upper surface of the valve disc are in contact, and the valve seat and the valve disc have openings; the openings on the valve seat and the valve disc are fan-shaped, and there are scrapers on the lower surface of the valve seat or the upper surface of the valve disc.

[0004] The above-mentioned rotary EGR valve has the following defects in actual use: 1. In high-temperature environments filled with corrosive exhaust gas and particulate abrasion, the traditional metal bushing (i.e., the guide sleeve mentioned in the text) relies on lubricant for operation. However, the lubricant evaporates faster at high temperatures, which leads to an increase in the friction coefficient between the bushing and the valve stem, intensified corrosion, and a shortened lifespan, affecting the valve's opening and closing accuracy and repeatability; 2. Acidic substances in the exhaust gas and condensate combine to corrode the valve body. High-speed particles in the exhaust gas will scour the inner wall of the valve body, causing surface scratches or coating peeling. Repeated thermal cycles and high pressure cause the metal substrate to expand and contract, leading to coating cracking or substrate deformation. The frequent occurrence of these conditions will cause carbon buildup, jamming, and leakage in the valve body. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a self-lubricating waste gas recirculation valve to address the shortcomings of the prior art and achieve long-term self-lubrication.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a self-lubricating waste gas recirculation valve, comprising a valve seat, a valve core, a valve stem assembly, and an electronic control assembly for controlling the opening and closing of the valve. The valve seat has an interconnected air inlet channel and an air outlet channel. The valve core is placed in the air inlet channel and has a valve hole for waste gas to enter. The valve stem assembly includes a valve stem penetrating the valve core, a bushing sleeved on the valve stem, and a valve plate installed at the end of the valve stem. The electronic control assembly drives the valve plate to rotate and change the effective flow area of ​​the valve hole to realize the opening and closing of the valve. The valve stem has an oil storage channel for storing lubricating oil along its axis. One end of the oil storage channel is located inside the valve stem, and the other end has an orifice set on the end face of the valve stem. A plug that can be detachably connected to the orifice is provided inside the orifice. Several herringbone grooves are evenly distributed on the outer circumferential surface of the valve stem. Several lubrication holes are evenly distributed in the herringbone grooves along the radial direction of the valve stem. The lubrication holes are connected to the oil storage channel.

[0007] The present invention, possessing the above-mentioned features, continuously delivers lubricating oil from the oil storage channel to the herringbone groove by setting lubrication holes radially on the valve stem. The lubricating oil is a high-temperature, non-volatile perfluoropolyether (PFPE) oil, achieving long-term self-lubrication, reducing the friction coefficient between the bushing and the valve stem, and improving the valve opening and closing accuracy. During the continuous rotation of the valve stem, the herringbone groove will squeeze the lubricating oil, forming a dynamic pressure oil film in the fitting gap between the valve stem and the bushing. When the engine operating conditions change rapidly (such as rapid acceleration, high load, or transient load), the dynamic pressure oil film has passive recovery characteristics, which can quickly compensate for the oil film thickness at the moment of impact, maintaining a continuous and stable fluid lubrication state, further improving the lubrication effect. The plug allows for the replenishment of lubricating oil, extending the service life of the valve.

[0008] A further feature of this invention is that the inner wall of the orifice is provided with an internal thread, the outer circumferential surface of the plug is provided with an external thread that connects with the thread of the orifice, and the end face of the plug that is flush with the valve stem is provided with a groove.

[0009] The present invention, which has the above features, has the following characteristics: the plug and the valve stem are connected by threads, which facilitates disassembly and assembly while preventing lubricating oil leakage; a groove is provided on the plug to facilitate disassembly and assembly with tools, and the plug is flush with the valve stem so as not to affect the connection between the valve stem and the electronic control components.

[0010] A further feature of this invention is that: the valve core has a ventilation chamber that connects the air inlet channel and the air outlet channel; a valve plate is provided at the bottom of the ventilation chamber; the valve plate has multiple leaf-shaped valve holes; the valve disc is located outside the valve core and has blades corresponding to the number of valve holes; rotating the valve disc changes the effective flow area of ​​the valve holes; the valve plate has ribs corresponding to the valve holes; and the valve disc is in contact with the ribs.

[0011] The present invention, which has the above-mentioned features, adopts a rotary vane valve structure to reduce the rotational inertia of the valve stem and improve the response speed; and sets ribs to fit the valve plate to improve the sealing performance of the valve plate and the valve hole.

[0012] A further feature of this invention is that the inner walls of the air intake channel and the air outlet channel are provided with a composite coating, the composite coating comprising a hard anodized film at the bottom layer and a PTFE coating at the top layer.

[0013] The present invention, which has the above-mentioned features, adopts a hard anodized film to improve the hardness of the valve body, avoid surface scratches caused by high-speed flowing particles, and enhance the wear resistance of the valve body; adopts a PTFE coating to effectively resist the corrosion of acidic substances and condensate in exhaust gas, while preventing carbon deposits from adhering to the inner wall of the valve body.

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0015] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0016] Figure 2 This is a cross-sectional view of an embodiment of the present utility model.

[0017] Figure 3 This is an exploded view of the valve stem in an embodiment of this utility model.

[0018] Figure 4 This is a cross-sectional view of the valve stem according to an embodiment of the present invention.

[0019] Figure 5 This is an exploded view of the valve stem and valve plate in an embodiment of this utility model.

[0020] Figure 6 This is an exploded view of the valve seat and valve core in an embodiment of this utility model. Detailed Implementation

[0021] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0022] like Figure 1-6The self-lubricating exhaust gas recirculation valve shown includes a valve seat 1, a valve core 2, a valve stem 4 assembly, and an electronic control assembly 3 for controlling the opening and closing of the valve. The valve seat 1 has an inlet channel 11 and an outlet channel 12 that are interconnected. The inner walls of the inlet channel 11 and the outlet channel 12 are coated with a composite coating, which includes a hard anodized film at the bottom and a PTFE coating at the top. The valve core 2 is placed in the inlet channel 11 and has a valve hole 21 for exhaust gas to enter. The valve stem 4 assembly includes a valve stem 4 penetrating the valve core 2, a bushing 5 sleeved on the valve stem 4, and a bushing mounted on the valve stem 4. The valve plate 6 at the end and the bushing 5 are made of graphite. The electronic control component 3 drives the valve plate 6 to rotate and change the effective flow area of ​​the valve orifice 21 to realize the opening and closing of the valve. The valve stem 4 has an oil storage channel 41 for storing lubricating oil along the axis. One end of the oil storage channel 41 is located inside the valve stem 4, and the other end orifice 42 is set on the end face of the valve stem 4. A plug 7 that can be detachably connected to the orifice 42 is provided inside the orifice 42. Several herringbone grooves 43 are evenly distributed on the outer circumference of the valve stem 4. Several lubrication holes 44 are evenly distributed in the herringbone grooves 43 along the radial direction of the valve stem 4. The lubrication holes 44 are connected to the oil storage channel 41.

[0023] The inner wall of the orifice 42 is provided with internal threads, and the outer circumferential surface of the plug 7 is provided with external threads that are threaded to the orifice 42. The end face of the plug 7 that is flush with the valve stem 4 is provided with a groove 71. The groove can be hexagonal, rectangular, or circular. It can be used with tools to disassemble or install the plug.

[0024] The valve core 2 has a ventilation chamber 22 that connects the air inlet channel 11 and the air outlet channel 12. The bottom of the ventilation chamber 22 is provided with a valve plate 8. The valve hole 21 is set on the valve plate 8 in a blade shape. The valve plate 6 is located outside the valve core 2 and has blades 61 corresponding to the number of valve holes 21. Rotating the valve plate 6 changes the effective flow area of ​​the valve hole 21. The valve plate 8 is provided with a rib 81 corresponding to the valve hole 21. The valve plate 6 is in contact with the rib 81.

[0025] When the exhaust gas recirculation valve is running, the lubricating oil in the oil reservoir flows out from the lubrication hole and fills the herringbone groove. Because the lubricating oil is a perfluoropolyether (PFPE) oil that does not easily evaporate at high temperatures, it achieves long-term lubrication. When the lubricating oil is consumed, the plug can be removed and the oil reservoir can be refilled during vehicle maintenance. During the continuous rotation of the valve stem, the herringbone groove will squeeze the lubricating oil, forming a hydrodynamic oil film in the fit clearance between the valve stem and the bushing. When the engine operating conditions change rapidly (such as rapid acceleration, high load or transient load), the hydrodynamic oil film has passive recovery characteristics, which can quickly compensate for the oil film thickness at the moment of impact and maintain a continuous and stable fluid lubrication state.

[0026] The electronic control component 3 includes a motor 31 and a controller 32 that controls the motor. The output shaft 311 of the motor 31 is linked to the valve stem through a coupling 9. The controller system and control logic in the controller are improved, forming a dual closed-loop control system composed of a current loop and a position loop. The current loop control is added, which can quickly respond to the drive current of the electromagnetic actuator through the current loop, compensate for mechanical inertia and nonlinear interference, and use position feedback as the outer loop target to achieve cascaded control, ensuring the accuracy and stability of the EGR valve under transient conditions. Feedforward compensation is added to the program to improve the dynamic stability of the product drive process, overcome the limit loop oscillation caused by nonlinear friction, and adopt a nonlinear deviation compensation algorithm to maintain high-precision valve position control under different opening degrees and temperatures. Combined with an adaptive algorithm, it can compensate for time-varying interference such as carbon buildup to a certain extent.

Claims

1. A self-lubricating waste gas recirculation valve, comprising a valve seat, a valve core, a valve stem assembly, and an electronic control assembly for controlling the opening and closing of the valve, wherein the valve seat has an inlet channel and an outlet channel that are interconnected, and the valve core is placed in the inlet channel and has a valve hole for waste gas to enter, characterized in that: The valve stem assembly includes a valve stem penetrating the valve core, a bushing sleeved on the valve stem, and a valve plate installed at the end of the valve stem. The electronic control component drives the valve plate to rotate, changing the effective flow area of ​​the valve orifice to realize the opening and closing of the valve. The valve stem has an oil storage channel for storing lubricating oil along its axis. One end of the oil storage channel is located inside the valve stem, and the other end has an orifice set on the end face of the valve stem. A plug that can be detachably connected to the orifice is provided inside the orifice. Several herringbone grooves are evenly distributed on the outer circumference of the valve stem. Several lubrication holes are evenly distributed in the herringbone grooves along the radial direction of the valve stem. The lubrication holes are connected to the oil storage channel.

2. The self-lubricating waste gas recirculation valve according to claim 1, characterized in that: The inner wall of the orifice is provided with internal threads, the outer circumferential surface of the plug is provided with external threads that connect with the orifice threads, and the end face of the plug that is flush with the valve stem is provided with a groove.

3. The self-lubricating waste gas recirculation valve according to claim 1, characterized in that: The valve core has a ventilation chamber that connects the air inlet channel and the air outlet channel. A valve plate is provided at the bottom of the ventilation chamber. The valve holes are set on the valve plate in the shape of blades. The valve plate is located outside the valve core and has blades corresponding to the number of valve holes. Rotating the valve plate changes the effective flow area of ​​the valve holes. The valve plate has ribs corresponding to the valve holes. The valve plate is in contact with the ribs.

4. A self-lubricating waste gas recirculation valve according to any one of claims 1-3, characterized in that: The inner walls of the air intake and air outlet channels are provided with a composite coating, which includes a hard anodized film at the bottom and a PTFE coating at the top.

5. A self-lubricating waste gas recirculation valve according to any one of claims 1-3, characterized in that: The bushing is made of graphite.

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