Double-rotation double-limiting exhaust gas recirculation valve

Abstract

A double-rotation double-limiting exhaust gas recirculation valve is provided with a valve rod driving mechanism, a valve rod and a disc in the valve body, the valve rod driving mechanism comprises a motor and a fan gear, the fan gear is provided with a convex seat extending towards the upper part of the valve rod and is provided with a return spring, the fan gear is connected with the top of the valve rod, the valve body is respectively provided with an upper limiting groove and a lower limiting groove, and the upper and lower limiting grooves are correspondingly limited and docked with the upper end and the lower end of the return spring. The fan gear is provided with a clamping block on the upper part and the outer side of the return spring. The upper and lower ends of the return spring are bidirectionally limited and clamped, the valve body is quickly and accurately assembled, platformization and generalization design are realized, and the production efficiency and adaptability are improved. The bidirectional rotation of the fan gear directly avoids the rigid impact of the return spring during return, can avoid the force deformation of the disc caused by instantaneous pressure change, and ensures the good work of the exhaust gas recirculation valve.

Description

Technical Field

[0001] This invention relates to pumps and valves, and more specifically to an exhaust gas recirculation valve for use in automobiles. Background Technology

[0002] An exhaust gas recirculation (EGR) valve is an electromechanical integrated product used to guide exhaust gas back into the intake manifold for re-combustion and to regulate the recirculation flow. After gasoline burns in the engine, a portion of the exhaust gas can be re-entered into the intake manifold through the EGR valve to participate in combustion again. This process allows for more complete fuel combustion, reducing energy consumption; it also lowers the temperature of the engine combustion chamber, thus inhibiting NO₂ production. x The compound produces an effect that reduces heat loss and decreases the engine load.

[0003] When a car engine operates in the low-to-medium speed, medium-to-high load range, introducing an appropriate amount of exhaust gas can improve combustion, reduce engine knocking, and decrease nitrogen oxide emissions. The exhaust gas recirculation valve (EGR valve, as a pressure regulating valve) in a low-pressure exhaust gas recirculation (LPEGR) system reduces the pressure at the point where exhaust gas enters the fresh air intake by increasing the pressure loss in the intake manifold, thereby improving efficiency. Specifically, it controls the opening angle of the disc via a motor to regulate the intake air volume and the pressure in the intake manifold. Currently, in automobiles (especially hybrid vehicles), the sector gear of the valve stem drive mechanism is connected to the valve stem via an intermediate linkage (and a return spring). The return spring is a single-limit type, which poses a risk of unstable locking. Assembly is cumbersome and complex, resulting in low efficiency. Furthermore, the sector gear rotates at high speed in one direction with rigid constraints, posing a risk of unilateral high-intensity impact and disc deformation. The sealing performance between the valve stem and valve body is also not tight enough and needs further improvement. These factors affect the proper functioning of the valve. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a double-rotating double-limit exhaust gas recirculation valve with a return spring on both sides and double limit, which is easy to assemble.

[0005] The objective of this invention is achieved through the following technical solution: a dual-rotation, dual-limit exhaust gas recirculation valve, comprising a valve body and an outer cover, wherein a valve stem drive mechanism and a valve stem are installed in the valve body, and a disc is installed on the valve stem and in the gas passage of the valve body. The valve stem drive mechanism sequentially includes a motor, a motor gear, a transmission gear, and a sector gear. The sector gear has a protrusion extending towards the upper part of the valve stem and a return spring is installed thereon. The sector gear is connected to the top of the valve stem. The valve body is respectively provided with an upper limit groove and a lower limit groove. The upper limit groove is connected to the upper end of the return spring for limiting, and the lower limit groove is connected to the lower end of the return spring for limiting.

[0006] A locking block is installed on the sector gear and on the outside of the return spring. The upper end of the locking block has an upper cut for locking the upper end of the return spring, and the lower end has a lower cut for locking the lower end of the return spring. The motor has a forward and reverse rotation control function, enabling the sector gear to rotate bidirectionally within the valve body's actuating chamber in its natural state: counterclockwise rotation, clockwise rotation, and return buffer rotation.

[0007] The top of the valve stem is connected to the shaft of the sector gear by a welded joint. The raised seat has a protrusion for limiting the lower part of the return spring. An upper bearing and a retaining ring are installed between the upper parts of the valve body and the valve stem, and a lower bearing and a plug are installed between the lower parts of the valve body and the valve stem.

[0008] By adopting the structure of this invention, a raised seat is added to the sector gear for mounting the return spring, eliminating the original intermediate connecting parts. The return spring is bidirectionally limited and locked at both ends, and can be assembled quickly and accurately with the valve body as a single unit. This achieves a platform-based and universal design, greatly improving production efficiency and adaptability. The motor-controlled bidirectional rotation of the sector gear directly avoids the rigid impact of the return spring during return. Energy is dissipated through buffering within this stroke, significantly extending the product life of the exhaust gas recirculation valve and preventing mechanical damage caused by high impact stress. It also avoids disc deformation due to instantaneous pressure changes, allowing for lower disc strength requirements and ensuring proper operation of the exhaust gas recirculation valve. Attached Figure Description

[0009] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0010] Figure 1 This is a schematic diagram of the structure of the dual-rotation dual-limit waste gas recirculation valve of the present invention.

[0011] Figure 2 for Figure 1 Partial sectional view.

[0012] Figure 3 for Figure 1 A schematic diagram of the valve body.

[0013] Figure 4 for Figure 2 A schematic diagram showing the connection structure between the sector gear, return spring, and locking block.

[0014] Figure 5 for Figure 2 A schematic diagram showing the connection between the valve body, return spring, and sector gear.

[0015] Figure 6This is a schematic diagram of the sector gear of the present invention in its natural state.

[0016] Figure 7 for Figure 6 The view of the sector gear after it has been rotated counterclockwise by an angle A.

[0017] Figure 8 for Figure 6 The view of the sector gear after clockwise rotation and return angle B. Detailed Implementation

[0018] Reference Figures 1 to 5 As can be seen, the present invention applies to a dual-rotation dual-limit exhaust gas recirculation valve for hybrid electric vehicle engines (or engines of traditional fuel vehicles and construction machinery), including a valve body 1 and an outer cover 2. A valve stem drive mechanism 3 and a valve stem 7 are installed inside the valve body 1. A disc 8 (i.e., a valve plate) is installed on the valve stem 7 and in the gas passage of the valve body 1. The valve stem drive mechanism 3 includes, in sequence, a motor 35, a motor gear 31, a transmission gear 32 (and a gear shaft 33), and a sector gear 34 (connected in sequence). The sector gear 34 has a protrusion 341 extending towards the upper part of the valve stem and a return spring 4 is installed thereon. The sector gear 34 is connected to the top of the valve stem 7. The valve body 1 is provided with an upper limit groove 14 (located in the upper position) and a lower limit groove 15 (located in the lower position, the two together forming the stable fulcrum of the return spring). The upper limit groove 14 is limited and connected to the upper end 41 of the return spring 4, and the lower limit groove 15 is limited and connected to the lower end 42 of the return spring 4. The protruding seat 341 replaces the original intermediate connecting piece between the sector gear and the valve stem. The disc 8 is located inside the gas passage 21 of the valve body 1 and can be fully open, partially open, or closed.

[0019] An upper bearing 6 (needle roller type, located at the top) and a retaining ring 5 (C-shaped, located at the bottom) are installed between the upper part of the valve body 1 and the valve stem 7 (above the gas passage 21 of the valve body 1). A lower bearing 9 (needle roller type, located at the top) and a plug 10 are installed between the lower part of the valve body 1 and the valve stem 7 (below the gas passage 21 of the valve body 1). This enhances the sealing performance between the valve body and the valve stem, effectively preventing exhaust gas (as well as oil, corrosive substances, particulate matter, etc.) from entering the space between the upper and lower parts of the valve stem and the valve body (preventing corrosion of the valve body and valve stem, which could cause valve stem jamming) and the interior of the valve stem drive mechanism 3. It also increases the smoothness of valve stem operation and reduces the probability of valve stem jamming. A circuit board 11 with a Hall sensor 12 is installed inside the outer cover 2. A magnet 13 corresponding to the position of the Hall sensor 12 is installed on the sector gear 34 and above the top of the valve stem 7 (which senses each other with the Hall sensor) to accurately sense the rotation speed of the sector gear and the valve stem, and precisely control the opening degree of the disc (fully open, partially open or closed).

[0020] like Figure 4 As shown, a locking block 342 is mounted on the sector gear 34 and on the outside of the return spring 4. The upper end of the locking block 342 has an upper cutout 343 for locking the upper end of the return spring, and its lower end has a lower cutout 344 for locking the lower end of the return spring, allowing the upper or lower end (i.e., the spring leg) of the return spring to be more easily engaged (or placed) within the upper or lower cutout. The protruding seat 341 has a protrusion 345 for limiting the lower part of the return spring. The sector gear 34 and locking block 342, along with the return spring 4, can be pre-assembled as an independent, complete sub-assembly. This sub-assembly can then be assembled quickly and accurately with the valve body 1 as a single unit, achieving a platform-based and universal design, greatly improving production efficiency and adaptability (e.g., ...). Figure 4 , Figure 5 As shown). Figure 2 As shown, the top of the valve stem 7 is connected to the shaft of the sector gear 34 via a welded part 36 (formed by welding process). Disc in its natural state (non-rigid constraint) and dynamic fine-tuning: The disc in its natural state is pre-tensioned by a return spring and constrained on both sides by spring legs at both ends. This invention abandons the traditional single-sided rigid limit, using the pre-tension force of the return spring itself to maintain the disc in its natural state position bidirectionally and elastically. The upper and lower ends (spring legs) of the return spring are respectively limited by the upper and lower limit grooves of the valve body and locked by the locking block of the sector gear, thus forming a stable force balance system.

[0021] like Figures 6 to 8 As shown, the motor 35 has forward and reverse rotation control functions, allowing the sector gear to rotate in its natural state (e.g., Figure 6 (As shown) It can rotate bidirectionally within the valve body's actuating chamber (first a large counterclockwise rotation with an angle of A, such as...) Figure 7 As shown in the lower mechanical dead center state, it then performs a clockwise rotation and a small-angle return buffer rotation with a small angle B, as... Figure 8 (As shown in the upper mechanical dead state). When the sector gear is in its natural position, it is allowed to rotate freely in both directions within a certain angle under the control of the motor rotation. This design creates a buffer zone or "overshoot stroke" at the end of the sector gear's return process, rather than a rigid end point. This directly avoids the rigid impact of the return spring during return; energy is dissipated through buffering within this stroke, significantly extending the product life of the exhaust gas recirculation valve and eliminating mechanical damage caused by high impact stress. When encountering instantaneous pressure changes, the disc, sector gear, and return spring can act as a whole, overcoming the preload of the return spring through minor rotational adjustments, thereby dynamically balancing the pressure on the disc's pressure surface and preventing disc deformation. This allows the disc to operate stably without extremely high structural strength, thus relatively reducing the high requirements for disc materials and manufacturing.

[0022] As shown in the attached figure, the valve stem drive mechanism 3 of the present invention operates (the motor 35 starts and drives the motor gear 31, transmission gear 32, and sector gear 34 to rotate in sequence), thereby driving the valve stem 7 to rotate. This causes the disc 8 on the valve stem 7 to also rotate, and thus the disc 8 in the gas passage 21 of the valve body 1 is in a fully open, partially open, or closed state. This allows the exhaust gas to enter from the gas inlet (right end) of the gas passage, to be discharged from the exhaust port (left end), or to be closed by preventing the exhaust gas from entering.

Claims

1. A dual-rotation, dual-limit exhaust gas recirculation valve, comprising a valve body and an outer cover, wherein a valve stem drive mechanism and a valve stem are installed within the valve body, and a disc is installed on the valve stem and within the gas passage of the valve body, characterized in that: The valve stem drive mechanism includes a motor, a motor gear, a transmission gear, and a sector gear in sequence. The sector gear has a protrusion extending towards the upper part of the valve stem and a return spring is installed thereon. The sector gear is connected to the top of the valve stem. The valve body is provided with an upper limit groove and a lower limit groove. The upper limit groove is connected to the upper end of the return spring, and the lower limit groove is connected to the lower end of the return spring.

2. The dual-rotation dual-limit waste gas recirculation valve as described in claim 1, characterized in that: A locking block is installed on the sector gear and on the outside of the return spring. The upper end of the locking block has an upper cut for locking the upper end of the return spring, and the lower end has a lower cut for locking the lower end of the return spring.

3. The dual-rotation dual-limit waste gas recirculation valve as described in claim 1 or 2, characterized in that: The motor has forward and reverse rotation control functions, enabling the sector gear to rotate bidirectionally within the valve body's actuator chamber in its natural state: counterclockwise rotation, clockwise rotation, and return buffer rotation.

4. The dual-rotation dual-limit waste gas recirculation valve as described in claim 1 or 2, characterized in that: The top of the valve stem is connected to the shaft of the sector gear by a welded joint.

5. The dual-rotation dual-limit waste gas recirculation valve as described in claim 1, characterized in that: The protruding seat has a protrusion for the lower limit of the body of the return spring.

6. The dual-rotation dual-limit waste gas recirculation valve as described in claim 1, characterized in that: An upper bearing and a retaining ring are installed between the upper part of the valve body and the upper part of the valve stem, and a lower bearing and a plug are installed between the lower part of the valve body and the lower part of the valve stem.

7. The dual-rotation dual-limit waste gas recirculation valve as described in claim 3, characterized in that: A circuit board with a Hall sensor is installed inside the outer cover, and a magnet corresponding to the position of the Hall sensor is installed on the sector gear and above the top of the valve stem.

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