Air filter resonant cavity for controlling air hammer effect and air hammer effect control method

Abstract

The invention discloses an air filter resonant cavity for controlling an air hammer effect and an air hammer effect control method, and belongs to the technical field of engine air inlet systems. The air filter resonant cavity comprises a cavity body and a plurality of branch pipe assemblies, wherein the cavity body comprises a main cavity and an auxiliary cavity which are communicated with each other; the plurality of branch pipe assemblies are obliquely arranged on the auxiliary chamber in parallel; the branch pipe assembly further comprises a pre-pressing supporting structure and an accelerator linkage mechanism, the pre-pressing supporting structure enables the elastic buffering film to be in a pre-deformation state, and the accelerator linkage mechanism presses the elastic buffering film to reduce the buffering volume through a linkage pressing ring when the accelerator is started and releases the elastic buffering film to recover the buffering volume when the accelerator is closed. Distributed broadband buffering is achieved through the multiple branch pipe assemblies, self-adaptive adjustment of the buffering volume is achieved through the pre-pressing supporting structure and the accelerator linkage mechanism, the maximum buffering capacity is provided when the air hammer effect occurs when an accelerator is closed, and the air inlet responsiveness and the air hammer restraining effect are both considered.

Description

Technical Field

[0001] This invention relates to the field of engine intake system technology, and in particular to an air filter resonant cavity and a method for controlling air hammer effect. Background Technology

[0002] Air hammer (also known as intake pulsation or pressure pulsation) is a common problem in the intake systems of all-terrain vehicles (ATVs) and automobiles. Air hammer refers to the phenomenon where, during engine operation, the airflow in the intake manifold is suddenly stopped or altered due to the periodic opening and closing of the intake valves and the rapid adjustment of the throttle valve, resulting in pressure fluctuations within the manifold.

[0003] Specifically, when the driver quickly releases the accelerator, the throttle valve closes rapidly, abruptly stopping the airflow that was originally flowing from the air filter towards the throttle valve. The airflow is instantly compressed within the intake manifold, generating positive pressure pulsations. Subsequently, the airflow rebounds and flows back, potentially generating negative pressure pulsations. These pressure pulsations propagate and reflect repeatedly within the manifold, creating continuous oscillations.

[0004] Air hammer has several adverse effects: First, the impact force generated by pressure pulsations acts on various components of the intake system, which, over time, may lead to loosening of pipe joints, accelerated aging of seals, and even fatigue damage to components. Second, pressure pulsations produce noticeable intake noise, affecting ride comfort. Third, pressure pulsations interfere with the engine's normal intake process, affecting charging efficiency and combustion stability, thus impacting engine power output and fuel economy. For all-terrain vehicles, the air hammer problem is particularly pronounced due to their harsh operating environment and drastic changes in operating conditions.

[0005] To suppress the air hammer effect, existing technologies typically incorporate a resonant cavity into the intake system. Utilizing the Helmholtz resonance principle, the resonant cavity is designed with specific geometric parameters for its volume and connecting pipes to resonate at a particular frequency, thereby absorbing and attenuating pressure pulsations near that frequency.

[0006] However, existing resonant cavity technology has the following shortcomings: First, the frequency band is limited. Traditional resonant cavities are designed based on the Helmholtz resonance principle, and their effective operating frequency depends on the cavity volume and the geometric parameters of the connecting neck. They can usually only suppress pressure pulsations at specific frequencies or within a narrow frequency band. However, in actual operating conditions, the engine speed varies greatly, and the frequency of pressure pulsations also changes accordingly. A single resonant cavity is unlikely to achieve effective suppression over a wide frequency band.

[0007] Second, it cannot adaptively adjust. Traditional resonant cavities are passive structures with fixed volumes, and their buffering characteristics are fixed after design and manufacturing, making it impossible to adaptively adjust according to the actual operating conditions of the engine. This results in insufficient buffering effect under some operating conditions, while excessive buffering may affect intake responsiveness under other operating conditions.

[0008] Third, it is difficult to achieve a good balance between intake responsiveness and air hammer suppression. To enhance air hammer suppression, it is necessary to increase the volume of the resonant cavity or add a buffer structure; however, a larger buffer volume will lead to sluggish intake response, affecting acceleration performance. Existing technologies struggle to achieve a good balance between intake responsiveness and air hammer suppression capabilities.

[0009] Fourth, the reliability and durability of the buffer structure. Some existing technologies use structures such as elastic diaphragms or springs for buffering, but these structures are prone to fatigue failure under long-term high-frequency vibration and pressure impact; at the same time, the recovery characteristics of elastic elements are singular and lack protection at extreme positions, which may lead to excessive deformation and damage under abnormal working conditions.

[0010] Therefore, there is a need for an air filter resonant cavity technology that can achieve wideband pressure pulsation suppression, adaptively adjust buffer characteristics according to engine operating conditions, and take into account both intake responsiveness and air hammer suppression capabilities. Summary of the Invention

[0011] The technical problem to be solved by this invention is: how to effectively suppress the air hammer effect caused by valve opening and closing, throttle adjustment and other factors in the air intake system of all-terrain vehicles or automobiles, while taking into account the balance between intake responsiveness and air hammer suppression capability.

[0012] To solve the above-mentioned technical problems, the present invention provides an air filter resonant cavity for controlling the air hammer effect, comprising: The cavity includes a main chamber and a secondary chamber, one end of the secondary chamber communicating with the main chamber and the other end forming an opening; multiple branch pipe assemblies are arranged side by side and obliquely on the secondary chamber, the oblique direction of the branch pipe assembly being that its free end is biased towards the opening end of the secondary chamber; each branch pipe assembly includes: a branch pipe body, one end of which communicates with the secondary chamber; a flow guide plate, disposed in the branch pipe body, for allowing airflow to pass through and limiting the displacement range of the elastic buffer membrane; an elastic buffer membrane, disposed on the side of the flow guide plate opposite to the secondary chamber, for undergoing elastic deformation under airflow impact to absorb impact energy; and an end cap, disposed at the free end of the branch pipe body, for limiting the elastic buffer membrane and allowing the space behind the elastic buffer membrane to communicate with the external atmosphere.

[0013] Furthermore, the elastic buffer membranes in the multiple branch pipe assemblies have different elastic coefficients. By setting elastic buffer membranes with different elastic coefficients, pressure pulsations of different frequencies can be absorbed and attenuated, thereby achieving a broadband air hammer effect suppression effect.

[0014] Furthermore, the end cap is detachably connected to the branch pipe body. By removing the end cap, the elastic buffer membrane can be easily installed, inspected, or replaced.

[0015] Furthermore, at least one of the branch pipe assemblies further includes: A pre-compression support structure is disposed between the flow guide plate and the elastic buffer membrane, which is used to make the elastic buffer membrane in a pre-deformed state in its natural state, bulging away from the flow guide plate. The throttle linkage mechanism includes a linkage pressure ring that can move axially along the branch pipe body and a transmission assembly for connecting the throttle operation mechanism. The linkage pressure ring is used to compress the elastic buffer membrane to reduce its deformation margin when the throttle is opened, and to release the elastic buffer membrane to restore its deformation margin when the throttle is closed.

[0016] Furthermore, the preload support structure includes: A permanent magnet base is fixedly mounted on the flow guide plate and faces the elastic buffer membrane; A magnetic floating bracket is connected to the side of the elastic buffer membrane away from the flow guide plate. The opposing surfaces of the magnetic floating bracket and the permanent magnet base have the same polarity, and a magnetic repulsion force is generated between them.

[0017] The advantages of using a magnetic repulsion structure are: magnetic repulsion is a non-contact force, there is no mechanical friction or wear, and it can provide a progressive reaction force for the pressing action of the linkage pressure ring, making the system response smooth; at the same time, the characteristic that magnetic repulsion increases sharply with decreasing distance can effectively prevent the elastic buffer membrane from completely collapsing or over-expanding under extreme working conditions, protecting the elastic buffer membrane from overload damage.

[0018] Furthermore, the magnetic floating support has a pre-compression pin on the side facing away from the elastic buffer membrane. The pre-compression pin is used to cooperate with the throttle linkage mechanism to transmit the compressive force of the linkage pressure ring.

[0019] Furthermore, the transmission assembly includes a push rod and a cable. The push rod passes through the end cap and connects to the linkage pressure ring. One end of the cable is connected to the push rod, and the other end is used to connect to the throttle operating mechanism. When the driver twists the throttle, the cable pulls the push rod to move, and the push rod drives the linkage pressure ring to move axially, thereby compressing or releasing the elastic buffer membrane.

[0020] Furthermore, the inner edge of the linkage pressure ring is provided with a pressing portion corresponding to the edge area of ​​the elastic buffer membrane, and the outer edge of the linkage pressure ring is provided with a radially extending limiting groove. The branch pipe body or the end cap is provided with a limiting pin that cooperates with the radially limiting groove. The pressing portion is used to compress the outer ring area of ​​the elastic buffer membrane to reduce the effective deformation area; the cooperation between the radially limiting groove and the limiting pin ensures the accuracy and stability of the linkage pressure ring's movement direction, while limiting the movement stroke of the linkage pressure ring.

[0021] The present invention also provides a method for controlling the air hammer effect based on the above-mentioned air filter resonant cavity, comprising: When the throttle is opened, the throttle linkage mechanism drives the linkage pressure ring to compress the outer ring area of ​​the elastic buffer membrane to reduce the effective deformation area of ​​the elastic buffer membrane. At the same time, the middle part of the elastic buffer membrane overcomes the supporting force of the pre-compression support structure and moves towards the guide plate. The two work synchronously to reduce the buffer volume. When the throttle is closed, the linkage pressure ring releases the elastic buffer membrane, and the pre-pressure support structure pushes the elastic buffer membrane back to the pre-deformed state, so that the elastic buffer membrane absorbs the pressure pulsation caused by the throttle closing with the maximum effective deformation area and the maximum deformation margin.

[0022] Furthermore, when the elastic buffer membrane deforms toward the flow guide plate under pressure pulsation impact, the pre-compression support structure provides a restoring force that increases with the amount of deformation, so as to prevent the elastic buffer membrane from adhering to the flow guide plate.

[0023] Compared with the prior art, the present invention has the following beneficial effects: 1. Distributed buffering and broadband absorption: By setting up multiple parallel branch pipe components, the impact force of the backflow is decomposed; at the same time, the elastic buffer membrane in each branch pipe component can adopt different elastic coefficients to absorb pressure pulsations of different frequencies, thereby achieving broadband air hammer effect suppression.

[0024] 2. Inclined design in line with airflow direction: The inclination direction of multiple branch pipe assemblies is such that their free ends are biased towards the opening of the secondary chamber. This inclination direction is in line with the direction of the airflow flowing back when the throttle is closed, so that the airflow can smoothly enter each branch pipe assembly and improve the buffering efficiency.

[0025] 3. Adaptive Variable Volume and Precise Matching to Operating Conditions: Through the synergistic action of the pre-compression support structure and the throttle linkage mechanism, the buffer volume is actively adjusted. During acceleration, the buffer volume decreases to improve intake responsiveness; during deceleration, the buffer volume is restored to enhance air hammer suppression. Specifically, the air hammer effect mainly occurs at the moment the throttle is closed, at which point the linkage pressure ring is released, and the elastic buffer membrane is at its maximum effective deformation area and maximum deformation margin, providing maximum buffering capacity at the moment when buffering is most needed.

[0026] 4. Dual Synchronous Adjustment Mechanism: When the throttle is opened, the linkage pressure ring compresses the outer ring area of ​​the elastic buffer membrane to reduce the effective deformation area. At the same time, the middle part of the elastic buffer membrane moves down to overcome the support force of the pre-compression support structure to reduce the deformation margin. The two work synchronously to achieve rapid and large-scale adjustment of the buffer volume.

[0027] 5. Pre-compression coupling buffer and self-recovery characteristics: The pre-compression support structure puts the elastic buffer membrane in a pre-deformed state in its natural state, eliminating the response dead zone and giving it bidirectional buffering capability; after deformation, the pre-compression support structure automatically guides the elastic buffer membrane back to the preset equilibrium position, which is more controllable and stable than pure elastic recovery.

[0028] 6. Extreme position protection: When using a magnetic repulsion preload support structure, the magnetic repulsion force increases sharply as the distance decreases, providing a progressively enhanced recovery force for the elastic buffer membrane. This effectively prevents the elastic buffer membrane from completely collapsing to the flow guide plate or over-expanding under extreme working conditions, protecting the elastic buffer membrane from overload damage.

[0029] 8. Abnormal Operating Condition Protection: All-terrain vehicles operate in harsh environments, and the engine may encounter abnormal operating conditions such as backfire, generating pressure shocks far exceeding normal operating conditions. The elastic buffer membrane can absorb this impact energy through significant elastic deformation, protecting other components of the intake system. Attached Figure Description

[0030] Figure 1 The overall appearance and structure of the air filter resonant cavity are shown in the figure. The assembly relationship between the cavity 1 and multiple branch pipe assemblies 2 can be seen from the figure. The multiple branch pipe assemblies 2 are arranged side by side and at an angle on the cavity 1.

[0031] Figure 2 The diagram shows a partially cut-away internal structure of cavity 1. Cavity 1 includes a main chamber 11 and a secondary chamber 12. One end of the secondary chamber 12 communicates with the main chamber 11, and the other end forms an opening. A in the diagram indicates... Figure 3 The viewing direction. In use, one end of the main chamber 11 is connected to the air filter, and one end of the outlet of the auxiliary chamber 12 is connected to the engine throttle valve.

[0032] Figure 3 yes Figure 2The magnified view at point A shows the internal structure of the branch pipe assembly 2 in Embodiment 1. Each branch pipe assembly 2 includes a branch pipe body 21, a flow guide plate 23, and an elastic buffer membrane 22. The flow guide plate 23 is disposed inside the branch pipe body 21, and the elastic buffer membrane 22 covers the flow guide plate 23. The figure shows the different states of the elastic buffer membrane 22 in the three branch pipe assemblies 2: slightly bulging, not bulging, and significantly bulging, to facilitate observation and understanding of the working principle of the elastic buffer membrane 22.

[0033] Figure 4 The cross-sectional structure of the branch pipe assembly 2 in Embodiment 2 is shown, with a focus on the internal structure of the preload support structure 25 and the throttle linkage mechanism 3.

[0034] Figure 5 The external structure of the branch pipe assembly 2 in Embodiment 2 is shown, and the assembly relationship between the throttle linkage mechanism 3 and the branch pipe body 21 can be seen. The linkage pressure ring 31 is sleeved on the outside of the free end of the branch pipe body 21 and can move along the axial direction of the branch pipe body 21.

[0035] Figure label: 1. Cavity; 11. Main chamber; 12. Secondary chamber; 2. Branch pipe assembly; 21. Branch pipe body; 22. Elastic buffer membrane; 23. Guide plate; 24. End cap; 25. Pre-compression support structure; 251. Permanent magnet base; 252. Magnetic floating bracket; 253. Pre-compression top column; 3. Throttle linkage mechanism; 31. Linkage pressure ring; 311. Pressing part; 312. Radial limiting groove; 32. Push rod; 33. Cable. Detailed Implementation

[0036] The embodiments of the present invention will now be described in detail with reference to all the accompanying drawings.

[0037] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive. Example

[0038] like Figure 1 As shown, this embodiment provides an air filter resonant cavity for controlling the air hammer effect, which is applied to the air intake system of all-terrain vehicles or automobiles to effectively suppress pressure pulsations in the air intake system caused by valve opening and closing, throttle adjustment, etc., i.e., the air hammer effect.

[0039] like Figures 2 to 3As shown, the air filter resonant cavity of this embodiment includes an integrally formed cavity 1 and multiple branch pipe assemblies 2 disposed on the cavity 1. The cavity 1 includes a main chamber 11 and a secondary chamber 12 with a long tube structure. One end of the secondary chamber 12 is connected to the main chamber 11, and the other end forms an opening. Multiple branch pipe assemblies 2 are arranged side by side and obliquely on the secondary chamber 12, with the free end of the multiple branch pipe assemblies 2 biased towards the opening end of the secondary chamber 12.

[0040] In this embodiment, there are three branch pipe assemblies 2, which are arranged sequentially along the length of the secondary chamber 12. Figure 3 As shown, each branch pipe assembly 2 includes a branch pipe body 21, a flow guide plate 23 installed at the inlet of the branch pipe body 21, an elastic buffer membrane 22 covering the flow guide plate 23, and an end cap 24 that confines the elastic buffer membrane 22 within the branch pipe body 21. Figure 3 The elastic buffer membrane 22 in the middle is in three different states: slightly bulging, not bulging, and significantly bulging. These are not fixed working states, but are only for the convenience of observation and understanding.

[0041] The branch pipe body 21 is a hollow tubular structure, with one end connected to the secondary chamber 12 and the other end being a free end. The guide plate 23 has through holes, allowing airflow to pass through and impact the elastic buffer membrane 22; simultaneously, the guide plate 23 can prevent the elastic buffer membrane 22 from being sucked out in the reverse direction when negative pressure is generated in the secondary chamber 12, thus ensuring the stability of the elastic buffer membrane 22. The elastic buffer membrane 22 is made of elastic material and can undergo elastic deformation under airflow impact, thereby absorbing the impact energy of the airflow. The end cap 24 is detachably connected to the branch pipe body 21 and has vent holes, allowing the space behind the elastic buffer membrane 22 to communicate with the external atmosphere; when the elastic buffer membrane 22 bulges and deforms into the branch pipe body 21 under airflow impact, the vent holes can balance the air pressure in the space behind the elastic buffer membrane 22, preventing pressure changes caused by the sealed space from hindering the elastic deformation of the elastic buffer membrane 22, thus ensuring that the elastic buffer membrane 22 can respond freely and sensitively to airflow impact. The elastic buffer membrane 22 can be easily installed, inspected, or replaced by removing the end cap 24.

[0042] Furthermore, the elastic buffer membranes 22 in the multiple branch pipe assemblies 2 have different elastic coefficients. By setting elastic buffer membranes 22 with different elastic coefficients, pressure pulsations of different frequencies can be absorbed and attenuated, thereby achieving a broadband air hammer effect suppression effect.

[0043] The working principle of this embodiment is as follows: In use, one end of the main chamber 11 of cavity 1 is connected to the air filter, and the other end of the auxiliary chamber 12 is connected to the engine throttle valve. When the engine is running, the driver controls the opening and closing of the throttle valve by operating the accelerator. At the moment the throttle valve closes, the airflow from the air filter towards the throttle valve is suddenly stopped, and the airflow is instantaneously compressed within cavity 1, generating pressure pulsations.

[0044] At this time, some of the compressed airflow flows back along the secondary chamber 12 and enters each branch pipe assembly 2. Since the inclination direction of the branch pipe assembly 2 is along the direction of the backflowing airflow, the backflowing airflow can smoothly enter each branch pipe assembly 2. The airflow enters the interior of the branch pipe body 21 through the through holes on the guide plate 23, impacting the elastic buffer membrane 22. The elastic buffer membrane 22 undergoes elastic deformation to absorb the impact energy of the airflow.

[0045] When the throttle valve reopens, a momentary negative pressure may be generated in the secondary chamber 12. At this time, the guide plate 23 can effectively prevent the elastic buffer membrane 22 from being sucked out by the negative pressure, ensuring that the elastic buffer membrane 22 is always in the correct position within the branch pipe body 21.

[0046] Since multiple branch pipe assemblies 2 are arranged in parallel, the impact force of the backflowing airflow is decomposed by multiple branch pipe assemblies 2; at the same time, since the elastic buffer membranes 22 in each branch pipe assembly 2 have different elastic coefficients, they can absorb pressure pulsations of different frequencies respectively, thereby effectively suppressing the air hammer effect.

[0047] The air filter resonant cavity in this embodiment also has the following additional technical effects: I. Intake noise reduction In this embodiment, multiple elastic buffer membranes 22 with different elastic coefficients have different response and absorption characteristics to sound waves of different frequencies, thereby achieving wideband intake noise reduction.

[0048] II. Smooth Intake Pulsation The intake process of an engine is pulsating due to the periodic opening and closing of the intake valves, which affects the charging efficiency and smoothness of operation. In this embodiment, the elastic buffer membrane 22 can act as a "gas spring", absorbing the peak energy of pressure fluctuations and releasing it when the pressure drops, thereby smoothing the intake pulsation and improving the engine's intake efficiency and smoothness of operation.

[0049] III. Abnormal Operating Condition Protection All-terrain vehicles operate in harsh environments, and their engines may encounter abnormal conditions such as backfire, generating pressure shocks far exceeding normal operating conditions. In this embodiment, the elastic buffer membrane 22 can absorb this impact energy through significant elastic deformation, protecting other components of the intake system. Example

[0050] like Figures 4 to 5 As shown, this embodiment provides an active variable volume air filter resonant cavity, which is an improvement on the first embodiment. By introducing a pre-pressure support structure and a throttle linkage mechanism, the active control of the elastic buffer membrane is realized, so that the resonant cavity can adaptively adjust the buffer characteristics according to the engine operating conditions.

[0051] In this embodiment, the structure of the cavity 1 is the same as in Embodiment 1. The difference is that at least one of the multiple branch pipe assemblies 2 is equipped with a pre-compression support structure 25 and a throttle linkage mechanism 3, while the remaining branch pipe assemblies 2 retain the structure of Embodiment 1. Since each branch pipe assembly 2 is connected to the secondary cavity 12, when the elastic buffer membrane 22 of one of the branch pipe assemblies 2 is actively compressed or released, the effective buffer volume of the entire cavity 1 can be changed, thereby achieving overall adjustment of the intake system. The number of branch pipe assemblies 2 equipped with the throttle linkage mechanism 3 can be selected according to actual adjustment needs and available space.

[0052] like Figure 5 As shown, the pre-compression support structure 25 is used to ensure that the elastic buffer membrane 22 is in a pre-deformed state in its natural state, thereby eliminating the response dead zone and giving it bidirectional buffering capability. The pre-compression support structure 25 can be implemented in the form of magnetic repulsion, spring, or pneumatic, with magnetic repulsion structure being preferred.

[0053] When a magnetic repulsion structure is adopted, the pre-pressure support structure 25 includes a permanent magnet base 251 fixedly disposed at the center of the guide plate 23 and facing the elastic buffer membrane 22, a magnetic floating bracket 252 fixedly connected or integrally formed at the center of the back side of the elastic buffer membrane 22, and a pre-pressure top column 253 disposed on the side of the magnetic floating bracket 252 facing away from the elastic buffer membrane 22. The permanent magnet base 251 is made of high-temperature stable permanent magnet material, and its magnetic pole direction is arranged along the axial direction of the branch pipe body 21. The magnetic floating bracket 252 has embedded permanent magnets, and the magnetic poles on the side facing the permanent magnet base 251 are of the same polarity as the opposite magnetic poles of the permanent magnet base 251, generating magnetic repulsion between them. The pre-pressure top column 253 has a columnar protrusion structure, disposed at the center of the magnetic floating bracket 252, coaxially corresponding to the permanent magnet base 251, and forming the highest point of the magnetic floating bracket 252, used to cooperate with the throttle linkage mechanism 3. In its natural state, the magnetic repulsion between the permanent magnet base 251 and the magnetic floating support 252 pushes the middle part of the elastic buffer membrane 22 to bulge and deform in the direction away from the guide plate 23, forming an initial pre-deformed state. The advantages of using a magnetic repulsion structure are: the magnetic repulsion force is a non-contact force, there is no mechanical friction and wear, and it can provide a progressive reaction force for the pressing action of the throttle linkage mechanism 3, making the system response smooth. Furthermore, the skeleton material of the magnetic floating support 252 has elastic deformation and restoring capabilities, or its bottom is connected to the elastic buffer membrane 22 through a flexible connector, so that the magnetic floating support 252 has a relatively stable axial floating characteristic and can move synchronously with the elastic buffer membrane 22.

[0054] This pre-deformation places the elastic buffer membrane 22 in the middle of its elastic working range, eliminating the response dead zone and giving it bidirectional buffering capability.

[0055] like Figure 4 As shown, the throttle linkage mechanism 3 includes a linkage pressure ring 31 sleeved on the outside of the free end of the branch pipe body 21, a push rod 32 passing through the end cap 24 and extending downward to connect to the linkage pressure ring 31, and a cable 33 connected at one end to the upper end of the push rod 32 and at the other end to the throttle operating mechanism. The linkage pressure ring 31 has a ring structure, with a pressing part 311 on its inner edge corresponding to the edge area of ​​the elastic buffer membrane 22, and a radially limiting groove 312 extending axially on its outer edge. The branch pipe body 21 or the end cap 24 is provided with a limiting pin that cooperates with the radially limiting groove 312. The limiting pin is inserted into the radially limiting groove 312, so that the linkage pressure ring 31 can only reciprocate along the axial direction of the branch pipe body 21 and cannot rotate circumferentially. At the same time, the upper and lower end faces of the radially limiting groove 312 limit the movement stroke of the linkage pressure ring 31. The push rod 32 slides through the guide hole on the end cap 24, with its lower end acting on the linkage pressure ring 31 (pressing down to contact it), and its upper end extending out of the end cap 24 and connecting to the cable 33. The cable 33 is a flexible steel cable used to transmit the throttle turning action to the push rod 32. The linkage pressure ring 31 or the steel cable is equipped with a return spring.

[0056] Alternatively, a return spring can be provided between the push rod 32 and the end cover 24. The return spring is sleeved on the push rod 32 and abuts against the end cover 24 and the linkage pressure ring 31, and is used to reset the linkage pressure ring 31 to the initial position when the throttle is released.

[0057] When the driver twists the throttle, the cable 33 pulls the push rod 32 downwards. The push rod 32 drives the linkage pressure ring 31 downwards along the guide direction of the radial limiting groove 312, and the pressing part 311 presses against the outer ring area of ​​the elastic buffer membrane 22. At this time, the magnetic floating bracket 252 overcomes the magnetic repulsion force and moves towards the permanent magnet base 251. The greater the throttle twist, the greater the downward stroke of the magnetic floating bracket 252, and the magnetic repulsion force increases accordingly to form a balance, making the system response smooth. At the same time, the pressing part 311 presses against the outer ring area of ​​the elastic buffer membrane 22, reducing the effective deformation area of ​​the elastic buffer membrane 22. The two work together to quickly reduce the buffer volume of the branch pipe assembly 2 and improve the intake response.

[0058] The working principle of this embodiment is as follows: When the driver twists the accelerator to accelerate, the cable 33 pulls the push rod 32 downward, and the linkage pressure ring 31 moves downward to press the outer ring area of ​​the elastic buffer membrane 22. The elastic buffer membrane 22 is deformed by pressure, and the gas inside is quickly discharged, which is equivalent to reducing the buffer volume of the branch pipe assembly 2. The airflow can enter the throttle valve more smoothly and quickly through the resonant cavity.

[0059] When the driver releases the accelerator to decelerate, the return spring 34 pushes the linkage pressure ring 31 to reset, and the pre-pressure support structure 25 pushes the elastic buffer diaphragm 22 back to its pre-deformed state. At this time, the elastic buffer diaphragm 22 has the maximum deformation margin. When the throttle valve closes and generates a hammer effect, the elastic buffer diaphragm 22 can fully undergo elastic deformation to absorb the impact energy of pressure pulsation.

[0060] The air filter resonant cavity in this embodiment also has the following additional technical effects: I. Adaptive Variable Volume and Operating Condition Matching The system reduces the buffer volume during acceleration to improve intake responsiveness and restores the buffer volume during deceleration to enhance air hammer suppression. The system can adaptively adjust according to engine operating conditions to achieve a balance between intake response and air hammer suppression.

[0061] In particular, the design of this embodiment is highly matched to the timing of the air hammer effect. The air hammer effect mainly occurs at the moment the driver closes the accelerator, at which time the airflow from the air filter to the throttle valve is suddenly stopped, generating pressure pulsations. In this embodiment, when the driver releases the accelerator, the linkage pressure ring 31 is released synchronously under the action of the return spring 34, and the elastic buffer membrane 22 returns to its pre-deformed state. At this time, the elastic buffer membrane 22 is exactly in the optimal energy absorption state, with the maximum deformation margin to absorb pressure pulsations. This means that the system can provide the maximum buffering capacity at the moment when buffering is most needed, achieving a precise match between buffering demand and buffering capacity.

[0062] II. Preload Coupling Buffer and Limit Position Protection The pre-stressed support structure 25 provides pre-deformation and self-recovery capabilities, while the elastic material provides energy dissipation capabilities. Together, they achieve an efficient and reliable buffering effect.

[0063] Furthermore, the magnetic repulsion preload support structure 25 also has a protective function to prevent the elastic buffer membrane 22 from sticking to the bottom or top. Under extreme operating conditions, such as abnormal pressure impacts generated during engine backfire or rapid acceleration, the elastic buffer membrane 22 may undergo excessive deformation. At this time, the magnetic repulsion force between the permanent magnet base 251 and the magnetic floating bracket 252 will increase sharply as the distance between them decreases, providing a progressively enhanced restoring force for the elastic buffer membrane 22, effectively preventing the elastic buffer membrane 22 from completely collapsing to the guide plate 23 or excessively expanding to the end cap 24. This nonlinear magnetic repulsion characteristic plays a "soft limiting" role, avoiding rigid impacts on the elastic buffer membrane 22 at extreme positions, thereby protecting the elastic buffer membrane 22 from overload damage and extending its service life.

[0064] III. Magnetic Self-Recovery Characteristics In this embodiment, the magnetic repulsion pre-compression support structure 25 endows the elastic buffer membrane 22 with excellent self-recovery characteristics. When the elastic buffer membrane 22 deforms under the impact of airflow or the pressure of the linkage ring 31, the magnetic repulsion between the permanent magnet base 251 and the magnetic floating support 252 will automatically guide the elastic buffer membrane 22 back to the preset equilibrium position.

[0065] Compared to relying solely on the elastic restoring force of the elastic material itself, magnetic self-restoring has the following advantages: First, the direction and magnitude of the magnetic repulsion force have clear physical laws, making the recovery process of the elastic buffer membrane 22 more controllable and stable, avoiding the displacement of the recovery position caused by creep or fatigue of the elastic material due to long-term use; Second, the magnetic repulsion force is a non-contact force, there is no mechanical friction, the recovery process is smooth and there is no energy loss; Third, the presence of the magnetic field provides a stable "potential energy trap" for the elastic buffer membrane 22, enabling it to stabilize quickly under small disturbances, improving the overall stability and response consistency of the system.

[0066] IV. Smoothness and Reliability The pre-compression support structure 25 provides a progressive reaction force for the compression action of the linkage pressure ring 31, avoiding rigid impact. When a magnetic repulsion structure is used, it is a non-contact support, eliminating mechanical friction and wear, thus improving reliability and service life. The cooperation between the radial limiting groove 312 and the limiting pin ensures the accuracy and stability of the movement direction of the linkage pressure ring 31.

[0067] V. Parameter Adjustability The degree of pre-deformation can be adjusted by adjusting the pre-pressure of the pre-pressure support structure 25 (such as changing the magnetic field strength or initial spacing of the permanent magnets in the permanent magnet base 251 and the magnetic floating bracket 252). The correspondence between the throttle opening and the stroke of the linkage pressure ring 31 can be adjusted by adjusting the length of the cable 33 or the stroke of the push rod 32. The pressure pulsation at different frequencies can be optimized by selecting elastic buffer membranes 22 with different elastic coefficients.

[0068] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all 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 air filter resonant cavity for controlling air hammer effect, characterized in that, include: The cavity (1) includes a main chamber (11) and a secondary chamber (12), one end of the secondary chamber (12) is connected to the main chamber (11), and the other end forms an opening; Multiple branch tube assemblies (2) are arranged side by side and inclined on the sub-chamber (12), and the inclination direction of the branch tube assembly (2) is such that its free end is biased toward the opening end of the sub-chamber (12); Each of the branch assembly (2) includes: The branch tube body (21) has one end connected to the secondary chamber (12); A flow guide plate (23) is disposed inside the branch pipe body (21) to allow airflow to pass through and limit the displacement range of the elastic buffer membrane (22); An elastic buffer membrane (22) is disposed on the side of the flow guide plate (23) away from the secondary chamber (12) to undergo elastic deformation under airflow impact to absorb impact energy; End cap (24) is provided at the free end of the branch pipe body (21) to limit the elastic buffer membrane (22) and to make the space behind the elastic buffer membrane (22) communicate with the outside atmosphere.

2. The air filter resonant cavity according to claim 1, characterized in that, The elastic buffer membranes (22) in the multiple branch assembly (2) have different elastic coefficients.

3. The air filter resonant cavity according to claim 1 or 2, characterized in that, The end cap (24) is detachably connected to the branch pipe body (21).

4. The air filter resonant cavity according to claim 1, characterized in that, At least one of the branch pipe assemblies (2) further includes: A pre-compression support structure (25) is disposed between the flow guide plate (23) and the elastic buffer membrane (22) to make the elastic buffer membrane (22) in a pre-deformed state in a direction away from the flow guide plate (23) in its natural state; The throttle linkage mechanism (3) includes a linkage pressure ring (31) that can move axially along the branch pipe body (21) and a transmission assembly for connecting the throttle operation mechanism. The linkage pressure ring (31) is used to press the elastic buffer membrane (22) to reduce its deformation margin when the throttle is opened, and to release the elastic buffer membrane (22) to restore its deformation margin when the throttle is closed.

5. The air filter resonant cavity according to claim 4, characterized in that, The preload support structure (25) includes: A permanent magnet base (251) is fixedly mounted on the flow guide plate (23) and faces the elastic buffer membrane (22). A magnetic floating bracket (252) is connected to the side of the elastic buffer membrane (22) away from the flow guide plate (23). The magnetic floating bracket (252) and the permanent magnet base (251) have the same polarity on their opposite sides, and a magnetic repulsion force is generated between them.

6. The air filter resonant cavity according to claim 5, characterized in that, The magnetic floating support (252) has a pre-compression top column (253) on the side facing away from the elastic buffer membrane (22).

7. The air filter resonant cavity according to claim 4, characterized in that, The transmission assembly includes a push rod (32) and a cable (33). The push rod (32) passes through the end cap (24) and is connected to the linkage pressure ring (31). One end of the cable (33) is connected to the push rod (32), and the other end is used to connect to the throttle operating mechanism.

8. The air filter resonant cavity according to claim 4, characterized in that, The inner edge of the linkage pressure ring (31) is provided with a pressing part (311) corresponding to the edge area of ​​the elastic buffer membrane (22), and the outer edge of the linkage pressure ring (31) is provided with a radial limiting groove (312) extending along the axial direction. The branch pipe body (21) or the end cap (24) is provided with a limiting pin that cooperates with the radial limiting groove (312).

9. A method for controlling the air hammer effect based on the air filter resonant cavity of claim 4, characterized in that, include: When the throttle is opened, the throttle linkage mechanism (3) drives the linkage pressure ring (31) to press the outer ring area of ​​the elastic buffer membrane (22) to reduce the effective deformation area of ​​the elastic buffer membrane (22). At the same time, the middle part of the elastic buffer membrane (22) overcomes the supporting force of the pre-pressure support structure (25) and moves towards the guide plate (23). The two work synchronously to reduce the buffer volume. When the throttle is closed, the linkage pressure ring (31) releases the elastic buffer membrane (22), and the pre-pressure support structure (25) pushes the elastic buffer membrane (22) back to the pre-deformed state, so that the elastic buffer membrane (22) absorbs the pressure pulsation caused by the throttle closing with the maximum effective deformation area and the maximum deformation margin.

10. The method for controlling the air hammer effect according to claim 9, characterized in that, When the elastic buffer membrane (22) deforms toward the flow guide plate (23) under pressure pulsation impact, the pre-compression support structure (25) provides a restoring force that increases with the amount of deformation to prevent the elastic buffer membrane (22) from adhering to the flow guide plate (23).

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