Umbrella-shaped passive valve of exhaust system and adjusting method of umbrella-shaped passive valve

Abstract

The invention provides an exhaust system umbrella-shaped passive valve and an adjusting method thereof. The exhaust system umbrella-shaped passive valve comprises a cylindrical valve body, a valve port is formed in the top end of the cylindrical valve body, an umbrella-shaped framework with a through hole in the middle is erected in the cylindrical valve body, and an airflow channel is formed in the cylindrical valve body in the axial direction; the valve plate with the push rod comprises a round valve plate, the push rod and an adjusting end cover, the push rod sequentially penetrates through the round valve plate and the through hole and is coaxial with the cylindrical valve body, the adjusting end cover is arranged at the end of the push rod, and the push rod is in sliding connection with the through hole and is fixedly connected with the round valve plate; the circular valve plate is arranged at the valve port of the cylindrical valve body and is used for being matched with the valve port to open or close the airflow channel; and the compression spring is arranged on the push rod in a sleeving mode, one end of the compression spring abuts against the umbrella-shaped framework, and the other end of the compression spring abuts against the adjusting end cover. The invention has the beneficial effects that the structure can be simplified, the operation reliability is improved, and the start-stop pressure is linear and easy to adjust.

Description

Technical Field

[0001] This invention relates to the technical field of exhaust passive valves, and more specifically, to an umbrella-shaped passive valve for an exhaust system and its adjustment method. Background Technology

[0002] With increasingly stringent emission regulations for automobiles and the widespread adoption of hybrid technology, higher demands are being placed on the acoustic performance, spatial arrangement, and cost control of exhaust systems, especially mufflers. To achieve efficient operation of mufflers under various conditions, passive valves, as a key airflow regulation component, are widely used.

[0003] Currently, most passive valves in mainstream exhaust systems employ torsion spring-based opening and closing structures, such as duckbill valves or valve plates that rotate around an axis. This design has revealed several inherent drawbacks in practice: First, its structure is typically complex, requiring additional shafts, hinges, and external spring seats, which not only increases manufacturing costs but also increases valve body size, contradicting the trend towards miniaturization and integration in exhaust systems. Second, the rotation of the valve plate can easily disturb the exhaust flow, potentially generating additional airflow noise and increasing exhaust resistance. More critically, the torsion springs it relies on are prone to performance degradation under harsh conditions of high temperature and vibration, leading to inaccurate valve opening and closing, insufficient durability, and easily affecting the overall vehicle noise, vibration, and acoustic roughness quality due to spring noise. Furthermore, the opening pressure characteristics of such valves are often non-linear and extremely inconvenient to adjust, making precise calibration difficult through simple methods. This severely limits their versatility across different vehicle models or performance requirements, forcing manufacturers to maintain a complex series of parts and increasing R&D and supply chain management costs.

[0004] Therefore, there is an urgent need for a new type of passive valve for exhaust systems that has a simpler structure, more reliable operation, linear opening and closing pressure, and is easy to adjust. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to simplify the structure, improve operational reliability, and achieve linear and easily adjustable opening and closing pressure. In order to overcome the defects of the above-mentioned prior art (or related technology), this invention provides an umbrella-shaped passive valve for an exhaust system and its adjustment method.

[0006] This invention provides an umbrella-shaped passive valve for an exhaust system, comprising: A cylindrical valve body, wherein a valve port is provided at the top end of the cylindrical valve body, an umbrella-shaped frame is provided inside the cylindrical valve body and a through hole coaxial with the cylindrical valve body is provided in the middle of the umbrella-shaped frame, and the interior of the cylindrical valve body is an airflow channel along the axial direction; A push rod valve includes a circular valve plate, a push rod that passes through the circular valve plate and the through hole and is coaxial with the cylindrical valve body, and an adjusting end cap disposed at the end of the push rod. The push rod is slidably connected to the through hole and fixedly connected to the circular valve plate. The circular valve plate is disposed at the valve port of the cylindrical valve body for cooperating with the valve port to open or close the airflow channel. A compression spring is sleeved on the push rod. One end of the compression spring abuts against the umbrella-shaped frame, and the other end of the compression spring abuts against the adjusting end cap. The adjusting end cap can be used to adjust the preload of the compression spring. The push rod valve is configured such that when the airflow pressure in the airflow channel overcomes the tension of the compression spring, the push rod moves axially to open the valve port, and when the airflow pressure decreases, the compression spring pulls the push rod back to reset and close the valve port.

[0007] Compared with the prior art, the umbrella-shaped passive valve for an exhaust system of the present invention has the following advantages: In this invention, a defined umbrella-shaped frame serves as the core support structure, organically integrating the cylindrical valve body, the valve plate with push rod, and the compression spring into a single unit. This design not only boasts a compact structure and high space utilization but also provides precise and stable installation benchmarks and guidance for internal moving parts, ensuring the linearity of the axial movement of the circular valve plate and operational reliability. Furthermore, the interior of the cylindrical valve body features an axial airflow channel, clearly defining the mainstream direction of airflow. When the valve is open, the airflow can smoothly and centrally pass through along the axial direction, which helps reduce flow resistance and airflow noise, thereby improving exhaust efficiency. Simultaneously, the invention establishes an opening condition where external airflow pressure overcomes the tension of the compression spring, and a closing mechanism where the compression spring pushes back to its original position when the airflow pressure decreases, facilitating easy adjustment of opening and closing.

[0008] In one possible implementation, an annular buffer is provided at the valve port of the cylindrical valve body, which is used to make the circular valve plate fit and seal with the circular valve plate when the push rod is reset to close the valve port.

[0009] Compared with existing technologies, the above technical solution can avoid direct rigid collision between the circular valve plate and the valve port when the valve port is closed by setting an annular buffer, which can effectively absorb impact energy and significantly reduce vibration noise when the valve port is closed.

[0010] In one possible implementation, the annular buffer is annular steel wool.

[0011] Compared with existing technologies, the above technical solution can utilize the excellent high-temperature resistance, elasticity and breathability of steel wool to achieve buffering, noise reduction and effective sealing.

[0012] In one possible implementation, the umbrella-shaped frame includes a circular bushing and a plurality of fixed connecting rods axially and evenly distributed on the outer wall of the circular bushing. The circular bushing has a through hole in the middle. One end of each fixed connecting rod is fixedly connected to the outer wall of the circular bushing, and the other end of each fixed connecting rod is fixedly connected to the inner wall of the cylindrical valve body.

[0013] Compared with existing technologies, the above technical solution clearly shows that the umbrella-shaped frame is composed of a circular bushing and multiple fixed connecting rods. This frame structure achieves maximum structural rigidity and support strength with minimal materials, while reducing the overall weight. At the same time, the circular bushing provides a precise shaft hole mating surface for the sliding of the push rod, ensuring the straightness of the circular valve plate's movement trajectory and preventing uneven wear and jamming. The fixed connecting rods firmly fix it in the cylindrical valve body, forming a reliable internal frame.

[0014] In one possible implementation, a spring base is provided on the outside of the circular bushing, one end of the compression spring is fixed to the bottom end of the spring base, and the other end of the compression spring is fixed to the top end of the adjustment end cap.

[0015] Compared with existing technologies, the above technical solution can provide a clear and reliable positioning and support surface for one end of the compression spring by setting a spring base, preventing the compression spring from shifting laterally, twisting or falling off during operation, ensuring that the spring force is always effectively transmitted along the axial direction, and guaranteeing the stability and durability of the valve operation.

[0016] In one possible implementation, a spiral guide groove is formed at the bottom end of the spring base along the axial direction, so that one end of the compression spring can be inserted into the spiral guide groove for fixation.

[0017] Compared with existing technologies, the above technical solution allows the end of the compression spring to be easily and accurately screwed into or pressed into the spiral guide groove for fixation, simplifies the assembly process, provides mechanical interlocking, prevents the compression spring from loosening under vibration, and further improves the assembly quality and long-term reliability of the product.

[0018] In one possible implementation, the adjusting end cap and the push rod are connected by a threaded connection. By rotating the adjusting end cap, the axial position of the adjusting end cap on the push rod is changed, thereby linearly adjusting the preload of the compression spring.

[0019] Compared with existing technologies, the above technical solution can achieve linear adjustment of the preload of the compression spring through threaded connection, so that the valve opening pressure threshold can be conveniently, accurately and continuously adjusted. This feature allows the umbrella-shaped passive valve of the same exhaust system to be adapted to engines of different displacements, vehicles with different exhaust back pressure requirements or different acoustic tuning goals through simple adjustment, which greatly expands the application range of the product.

[0020] In one possible implementation, the outer diameter of the cylindrical valve body is set to be suitable for welding to the baffle or connecting pipe of the exhaust system muffler.

[0021] Compared with existing technologies, the above technical solution can facilitate integration through standardized welding processes by setting the outer diameter of the cylindrical valve body to match the interface size of standard components in the exhaust system.

[0022] The present invention also provides a method for adjusting an umbrella-shaped passive valve in an exhaust system, applied to the aforementioned exhaust system support passive valve, comprising the following steps: Step S1: Based on the target operating conditions of the exhaust system, obtain the required opening pressure threshold of the umbrella-shaped passive valve of the exhaust system. Step S2: Rotate the adjusting end cap to change the compression amount of the compression spring, so as to adjust the actual opening pressure of the passive valve of the exhaust system to the opening pressure threshold.

[0023] The adjustment method of the umbrella-shaped passive valve of the exhaust system of the present invention has the following advantages compared with the prior art: This invention summarizes the adjustment process into two core steps: analyzing the target working condition to determine the opening pressure threshold and rotating the end cap to adjust the compression amount. It provides a clear and operable adjustment method, which facilitates convenient adjustment of the compression amount of the compression spring in actual scenarios. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the exploded structure of the present invention; Figure 3 This is a schematic diagram of the umbrella-shaped skeleton of the present invention; Figure 4 This is a schematic diagram showing the position of the compression spring of the present invention; Figure 5 This is a flowchart of the method steps of the present invention; Explanation of the numerical markings in the attached diagram: 1. Cylindrical valve body; 2. Valve port; 3. Through hole; 4. Circular valve plate; 5. Push rod; 6. Adjusting end cover; 7. Compression spring; 8. Annular buffer; 9. Circular bushing; 10. Fixed connecting rod; 11. Spring base. Detailed Implementation

[0025] First, those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] See Figures 1 to 4 This invention discloses an umbrella-shaped passive valve for an exhaust system. Its overall design is based on the linear drive principle of a compression spring 7, resulting in a compact structure, reliable performance, and easy adjustment. The umbrella-shaped passive valve mainly comprises three core components: a cylindrical valve body 1, a valve plate with a push rod, and a compression spring 7. The cylindrical valve body 1 serves as the fixed outer shell and mounting base of the entire valve. Its hollow interior forms an axially extending airflow channel. A precisely machined valve port 2 is located at the top of the cylindrical valve body 1, which is a key component for airflow control. In this embodiment, the cylindrical valve body 1 is typically made of heat-resistant stainless steel (such as SUS409 or SUS436) through precision casting or pipe machining. Its wall thickness is preferably 1.5mm to 2.5mm to reduce weight while ensuring sufficient structural strength. The outer diameter of the cylindrical valve body 1 is designed according to the inner diameter of the matching exhaust system muffler baffle opening or connecting pipe. It typically has a standard welding bevel, facilitating a secure and sealed connection with exhaust system components via automated welding processes (such as MIG welding).

[0028] In this embodiment of the invention, in order to provide stable support and guidance for the moving parts inside the cylindrical valve body 1, an umbrella-shaped frame is installed inside the cylindrical valve body 1. The core of the umbrella-shaped frame is a circular bushing 9, with a through hole 3 precisely machined in the middle, serving as a sliding bearing for the push rod 5. The circular bushing 9 is fixedly connected to the inner wall of the cylindrical valve body 1 by three (preferably more, but also possible) fixed connecting rods 10 evenly distributed circumferentially. The fixed connecting rods 10 can be connected at both ends by welding or integral molding. This "central bushing-radial connecting rod" structure, like the ribs of an umbrella, achieves extremely high rigidity with minimal material, ensuring the reference stability of the internal motion system. On the outer wall of the circular bushing 9, a spring base 11 is integrally molded or welded, with a spiral guide groove opened axially inside. The design of this spiral guide groove facilitates the precise insertion and fixation of the end of the compression spring 7, preventing the compression spring 7 from lateral slippage or displacement during operation. The specific structure of the spiral guide groove is not shown in the accompanying drawings. Any prior art that has spiral guide grooves on annular components can be applied.

[0029] In this embodiment of the invention, the valve plate with push rod is the moving part of the valve, used to perform opening and closing actions. It includes a circular valve plate 4, a push rod 5, and an adjusting end cap 6. The diameter of the circular valve plate 4 is slightly larger than the outer diameter of the valve port 2, used to cover and seal the valve port 2. The material is usually the same as or similar to the heat-resistant steel plate of the cylindrical valve body 1. One end of the push rod 5 is fixedly connected to the center of the circular valve plate 4 perpendicularly (e.g., by welding), and the other end is machined with external threads. The adjusting end cap 6 is a cap-shaped part with matching internal threads, screwed onto the external thread end of the push rod 5. The push rod 5 is driven from the circular valve plate 4... The disc 4 extends from the center of the back side, passes through the valve port 2 and the through hole 3 of the circular bushing 9 on the umbrella-shaped frame in sequence, and finally connects to the adjustment end cover 6. The push rod 5 and the through hole 3 of the circular bushing 9 are clearance fit, which allows the push rod 5 to slide axially with low friction. At the same time, the circular bushing plays a guiding role to ensure the straightness of the movement trajectory of the circular valve disc 4 and avoid jamming. In order to further reduce sliding friction and adapt to the high temperature environment of the exhaust system, several annular oil storage grooves can be machined on the inner wall of the through hole 3 on the circular bushing 9, and filled with high temperature resistant grease such as molybdenum disulfide high temperature paste before assembly.

[0030] In this embodiment of the invention, the compression spring 7 is sleeved on the push rod 5 and is the core component that provides the valve reset closing force. One end of the spring 7 is inserted into and fixed in the spiral guide groove of the spring base 11 of the umbrella-shaped frame, and the other end rests on the inner end face of the adjusting end cover 6. The compression spring 7 is preferably made of high temperature spring steel (such as Inconel 718 or similar austenitic stainless steel wire) to withstand the high temperature of exhaust and maintain long-term elastic stability.

[0031] In this embodiment of the invention, in order to optimize sealing and reduce closing impact noise, a ring of annular steel wool is welded to the edge of the valve port 2 of the cylindrical valve body 1 as an annular buffer 8. The annular steel wool protrudes slightly from the plane of the valve port 2. When the valve port 2 is closed, the circular valve plate 4 is pressed tightly against the fluffy and elastic annular steel wool under the action of spring force, instead of directly impacting the metal cylindrical valve body 1. This not only effectively absorbs impact energy and significantly reduces clicking noise, but also the elastic filling characteristics of the annular steel wool can compensate for small flatness errors, achieving better airtightness.

[0032] In this embodiment of the invention, the working principle of the umbrella-shaped passive valve of the exhaust system is as follows: the length of the compression spring 7 is lengthened by rotating the adjusting end cap 6 externally, so that it has sufficient preload to tightly fasten the circular valve plate 4 at the valve port. The valve is in a normally closed state. When the exhaust gas flow enters from the bottom of the cylindrical valve body 1, the gas pressure acting on the back of the circular valve plate 4 reaches and exceeds the preset preload of the compression spring 7 (i.e., the opening pressure threshold). The air flow pushes the entire valve plate assembly with push rod (including the circular valve plate 4, push rod 5 and adjusting end cap 6) to move inward along the axial direction of the push rod 5, while further lengthening the compression spring 7. At this time, the circular valve plate 4 leaves the valve port 2, forming an annular airflow gap, and the exhaust can pass through. When the exhaust back pressure drops and the gas thrust is less than the spring restoring force, the compression spring 7 pulls back the adjusting end cap 6 and drives the entire valve plate assembly with push rod to reset until the circular valve plate 4 is pressed back onto the annular steel wool, and the valve is closed.

[0033] In this embodiment of the invention, by rotating the adjusting end cap 6 using a tool (such as an Allen wrench), its axial position on the push rod 5 can be changed. When screwed in, the compression spring 7 is pre-compressed, the tension decreases, and the valve opening pressure threshold decreases; when screwed out, the tension increases, and the opening pressure threshold increases. This adjustment is linear, continuous, and precise, without the need to replace any parts. This allows the same specification of exhaust system passive valve to be adapted to different displacement engines, different acoustic tuning targets, or different exhaust back pressure requirements through simple post-calibration, greatly improving the product's versatility, realizing serialized design, and reducing R&D and material management costs.

[0034] See Figure 5 In this embodiment of the invention, an adjustment method for an exhaust system umbrella-shaped passive valve is also disclosed, applied to the aforementioned exhaust system umbrella-shaped passive valve, comprising the following steps: Step S1: Analyze the target operating conditions of the exhaust system (such as engine displacement, target exhaust acoustic spectrum, back pressure requirements, etc.), or determine the required opening pressure threshold of the umbrella-shaped passive valve of the exhaust system through bench testing and simulation calculation. In step S2, with the valve offline or installed on the test bench, use a tool to rotate the adjusting end cap 6. By observing the scale (optional design) on the adjusting end cap 6 or measuring its screw-in depth, the compression amount (i.e., preload) of the compression spring 7 can be changed. Pneumatic testing equipment can be used to apply a precisely measurable air pressure to the valve port 2 and observe the pressure value when the circular valve plate 4 is just opened. Adjust this actual opening pressure to the opening pressure threshold determined in step S1. This adjustment process is intuitive and simple, ensuring the consistency and traceability of product performance.

[0035] In the description of this invention, the references to "one embodiment," "some embodiments," "in this embodiment," "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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0036] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An umbrella-shaped passive valve for an exhaust system, characterized in that, include: A cylindrical valve body (1) is provided with a valve port (2) at the top end of the cylindrical valve body (1). An umbrella-shaped frame is provided inside the cylindrical valve body (1), and a through hole (3) coaxial with the cylindrical valve body (1) is opened in the middle of the umbrella-shaped frame. The interior of the cylindrical valve body (1) is an airflow channel along the axial direction. A push rod valve plate includes a circular valve plate (4), a push rod (5) that passes through the circular valve plate (4) and the through hole (3) in sequence and is coaxially arranged with the cylindrical valve body (1), and an adjustment end cap (6) disposed at the end of the push rod (5). The push rod (5) is slidably connected to the through hole (3) and fixedly connected to the circular valve plate (4). The circular valve plate (4) is disposed at the valve port (2) of the cylindrical valve body (1) for cooperating with the valve port (2) to open or close the airflow channel. A compression spring (7) is sleeved on the push rod (5). One end of the compression spring (7) abuts against the umbrella-shaped frame, and the other end of the compression spring (7) abuts against the adjusting end cap (6). The adjusting end cap (6) can be used to adjust the preload of the compression spring. The push rod valve is configured such that when the airflow pressure in the airflow channel overcomes the tension of the compression spring (7), the push rod (5) moves axially to open the valve port (2), and when the airflow pressure decreases, the compression spring (7) pulls back the push rod (5) to reset and close the valve port (2).

2. The umbrella-shaped passive valve for the exhaust system according to claim 1, characterized in that, An annular buffer (8) is provided at the valve port (2) of the cylindrical valve body (1) to make the circular valve plate (4) fit and seal with the circular valve plate (4) when the push rod (5) is reset to close the valve port (2).

3. The umbrella-shaped passive valve for the exhaust system according to claim 2, characterized in that, The annular buffer (8) is annular steel wool.

4. The umbrella-shaped passive valve for the exhaust system according to claim 1, characterized in that, The umbrella-shaped frame includes a circular bushing (9) and multiple fixed connecting rods (10) evenly distributed axially on the outer wall of the circular bushing (9). The circular bushing (9) has a through hole (3) in the middle. One end of each fixed connecting rod (10) is fixedly connected to the outer wall of the circular bushing (9), and the other end of each fixed connecting rod (10) is fixedly connected to the inner wall of the cylindrical valve body (1).

5. The umbrella-shaped passive valve for the exhaust system according to claim 4, characterized in that, The circular bushing (9) is provided with a spring base (11) on its outside. One end of the compression spring (7) is fixed to the bottom end of the spring base (11), and the other end of the compression spring (7) is fixed to the top end of the adjustment end cover (6).

6. The umbrella-shaped passive valve for the exhaust system according to claim 5, characterized in that, The bottom end of the spring base (11) has a spiral guide groove along the axial direction, so that one end of the compression spring (7) can be inserted into the spiral guide groove for fixation.

7. The umbrella-shaped passive valve for the exhaust system according to claim 1, characterized in that, The adjusting end cap (6) and the push rod (5) are connected by a thread. By rotating the adjusting end cap (6), the axial position of the adjusting end cap (6) on the push rod (5) is changed, so as to linearly adjust the preload of the compression spring (7).

8. The umbrella-shaped passive valve for the exhaust system according to claim 1, characterized in that, The outer diameter of the cylindrical valve body (1) is set to be suitable for welding with the baffle or connecting pipe of the exhaust system muffler.

9. A method for adjusting an umbrella-shaped passive valve in an exhaust system, characterized in that, An umbrella-shaped passive valve for an exhaust system as described in any one of claims 1-8, comprising the following steps: Step S1: Based on the target operating conditions of the exhaust system, obtain the required opening pressure threshold of the umbrella-shaped passive valve of the exhaust system. Step S2: Rotate the adjusting end cap (6) to change the compression amount of the compression spring (7) so as to adjust the actual opening pressure of the passive valve of the exhaust system to the opening pressure threshold.

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