Airflow channel noise reduction mechanism and gas compressor volute with noise elimination function

Abstract

The invention discloses an airflow channel noise reduction mechanism and a compressor volute with a noise elimination function, and relates to the technical field of noise reduction mechanisms, the airflow channel noise reduction mechanism comprises a plurality of vibrating diaphragms and a connecting rod, the connecting rod is connected with the vibrating diaphragms, the vibrating diaphragms are located in an air outlet of an airflow channel, and the connecting rod is fixed to the airflow channel. By means of the airflow channel noise reduction mechanism and the gas-solid sound transmission time difference, airflow multi-frequency-band noise elimination is achieved, noise generated in an airflow channel of an existing supercharged engine air compressor can be effectively reduced, and therefore aerodynamic noise at an air outlet of the airflow channel of the air compressor is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of noise reduction mechanisms, and in particular to an airflow channel noise reduction mechanism and a compressor volute with a noise reduction function. Background Art

[0002] In recent years, with the advancement of design technology, turbochargers have been developing towards large flow and high pressure ratio, and the noise problem of turbochargers has become increasingly prominent. However, the high compression ratio of the turbocharger greatly increases the energy of the compressed air discharged by the compressor, which will generate high-frequency and broadband exhaust noise at the compressor outlet, radiating outward through the exhaust pipe and becoming one of the main noise sources of the turbocharger. Excessive noise is not only a potential hidden danger to the normal operation of the equipment, but also detrimental to the normal work and life of the staff.

[0003] A large number of studies have confirmed that the frequency of compressor aerodynamic noise is high and it is one of the main noise sources of the supercharger. Reducing the aerodynamic noise of the compressor can effectively reduce the noise of the supercharger. One of the main ways to reduce noise is to control the noise in the propagation path of the noise. At present, the method of installing a muffler is mostly used to reduce noise, but the traditional Helmholtz resonator and expansion chamber muffler cannot effectively suppress this broadband noise. There are few measures to reduce noise by changing the structure of the compressor airflow channel itself.

[0004] In summary, the noise generated by the compressor of the existing supercharged engine is too loud, which increases the potential hidden dangers of normal operation of the equipment and is not conducive to the normal work and life of the staff. Summary of the invention

[0005] The object of the present invention is to provide an airflow channel noise reduction mechanism and a compressor volute with a noise reduction function to solve the problems existing in the above-mentioned prior art and significantly reduce the aerodynamic noise at the air outlet of the airflow channel.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides an airflow channel noise reduction mechanism, comprising a vibrating diaphragm and a connecting rod, wherein a plurality of the vibrating diaphragms are connected to the connecting rod, the vibrating diaphragms are located in an air outlet of the airflow channel, and the connecting rod is fixed to the airflow channel.

[0008] Preferably, a plurality of support rods are arranged on the connecting rod, a vibration diaphragm is connected to the end of each support rod, and the connecting rod is connected to the air flow channel via a supporting rod.

[0009] Preferably, the support rod passes through the outer wall of the airflow channel, and the support rod is connected to the outer surface of the airflow channel.

[0010] Preferably, the vibration diaphragm is a lightweight diaphragm, and the material of the lightweight diaphragm includes polyvinyl chloride, polyvinylidene fluoride and polyvinyl fluoride.

[0011] Preferably, the arrangement position of the vibrating diaphragm satisfies the half-wavelength silencing principle, ensuring that the sound transmission paths meet the requirements.

[0012] Preferably, the connecting rod is a lightweight connecting rod, and the material of the lightweight connecting rod includes aluminum alloy, fiberglass and carbon fiber.

[0013] Preferably, the vibration diaphragm is in the shape of an ellipse, a circle, a rhombus or a regular polygon, and its area is no more than 1 / 20 of the cross-sectional area of ​​the air flow channel.

[0014] Preferably, the airflow channel noise reduction mechanism is evenly arranged in a plurality of groups along the axial direction and the circumferential direction of the air outlet.

[0015] The present invention also relates to a compressor volute with a silencer function, comprising the above-mentioned airflow channel noise reduction mechanism and a compressor volute of a turbocharger, wherein a plurality of groups of the airflow channel noise reduction mechanisms are evenly distributed on the air outlet of the compressor volute.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The present invention realizes multi-band airflow silencing by utilizing the time difference of air-solid sound transmission through an airflow channel noise reduction mechanism, and can effectively improve the noise generated inside the compressor airflow channel of the existing supercharged engine, thereby reducing the aerodynamic noise at the air outlet of the compressor airflow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 Schematic diagram of the structure of the airflow channel noise reduction mechanism in an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the structure of a compressor volute with a muffler function in an embodiment of the present invention;

[0021] Figure 3 Schematic diagram of the principle of noise reduction in the airflow channel according to an embodiment of the present invention;

[0022] Figure 4Schematic diagram of the end surface structure of the airflow channel in an embodiment of the present invention;

[0023] Figure 5 is a schematic diagram of a noise propagation path in an embodiment of the present invention;

[0024] In the figure: 1-air inlet, 2-compressor volute, 3-air outlet, 4-connecting rod, 5-upstream diaphragm, 6-downstream diaphragm, 7-support rod, 8-support rod. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The object of the present invention is to provide an airflow channel noise reduction mechanism and a compressor volute with a noise reduction function, so as to solve the problems existing in the prior art and significantly reduce the aerodynamic noise at the air outlet of the airflow channel.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Embodiment 1

[0029] like Figures 1 to 5 As shown, this embodiment provides an air flow channel noise reduction mechanism, including a vibration diaphragm and a connecting rod 4, a plurality of vibration diaphragms are connected to the connecting rod 4, the vibration diaphragm is located in the air outlet 3 of the air flow channel, and the connecting rod 4 is fixed on the air flow channel.

[0030] As an optional solution, in this embodiment, a plurality of support rods 8 are arranged on the connecting rod 4, and a vibrating diaphragm is connected to the end of each support rod 8, and the connecting rod 4 is connected to the airflow channel through a supporting rod 7. The design of the support rod 8 allows multiple sound transmission channels from the upstream diaphragm 5 to different downstream diaphragms 6, thereby transmitting many columns of sound waves with different transmission distances from the downstream diaphragm 6, and the travel difference between each column of sound waves is continuous within a range, which makes the interference between the sound waves transmitted from the downstream lightweight diaphragm 6 of the invention have a noise reduction effect on noise within a wider frequency band, such as Figure 3 shown.

[0031] As an optional solution, in this embodiment, the support rod 8 passes through the outer wall of the airflow channel, wherein the diameter of the support rod 8 is smaller than the diameter of the hole passing through the outer wall, and the two are clearance-matched to prevent vibration between the support rod and the tube wall from generating additional noise, and the support rod 7 is connected to the outer surface of the airflow channel.

[0032] As an optional solution, the vibration diaphragm in this embodiment is a lightweight diaphragm, and the material of the lightweight diaphragm includes but is not limited to polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF).

[0033] As an optional solution, the arrangement position of the vibrating diaphragm in this embodiment meets the half-wavelength anechoic principle, ensuring that the different sound transmission paths meet It is convenient for an upstream diaphragm 5 and a downstream diaphragm 6 to appear, wherein the diaphragm that first contacts the noise is the upstream diaphragm 5 and the rest are the downstream diaphragms 6, so that the sound waves can be conducted by the airflow and the connecting rod 4 respectively, thereby resulting in a time difference in gas-solid conduction.

[0034] As an optional solution, in this embodiment, the connecting rod 4 is a lightweight connecting rod, and the material of the lightweight connecting rod includes but is not limited to aluminum alloy, fiberglass, carbon fiber, etc.

[0035] As an optional solution, the vibrating diaphragm in this embodiment is elliptical, circular, rhombus or regular polygonal, and its area is not greater than 1 / 20 of the cross-sectional area of ​​the airflow channel, and the distance d between the diaphragm and the inner wall of the volute is not greater than 1 / 20 of the cross-sectional diameter D of the volute flow channel, so as to minimize its influence on the flow inside the volute, as follows Figure 4 As shown, d<1 / 20D.

[0036] As an optional solution, in this embodiment, a plurality of groups of airflow channel noise reduction mechanisms are evenly distributed along the axial direction and circumferential direction of the air outlet 3 .

[0037] Embodiment 2

[0038] like Figure 2 As shown, in this embodiment, a compressor volute with a silencer function is provided, including the airflow channel noise reduction mechanism of the above-mentioned embodiment 1 and the compressor volute 2 of the turbocharger, the air outlet 3 of the compressor volute 2 is evenly provided with several groups of airflow channel noise reduction mechanisms along the axial direction and the circumferential direction, and the compressor volute 2 is provided with an annular air inlet 1.

[0039] The working principle of the airflow channel noise reduction mechanism in this embodiment is as follows: the noise generated by the airflow channel first causes the upstream diaphragm 5 to vibrate. On the one hand, the sound waves are transmitted to the downstream diaphragms 6 at different positions through the airflow; at the same time, the sound waves drive the downstream diaphragms 6 at different positions to vibrate through the connecting rod 4, and then are transmitted from each downstream diaphragm 6. Due to the structural support rod 8 structure of the connecting rod 4, the noise will generate several series of mutually interfering sound waves when flowing through each support rod 8 and the downstream diaphragm 6. The wavelength difference between different sound waves will make the interference of sound waves have the effect of reducing noise. Here, the wavelength of the noise sound wave is set to λ. In this way, as long as the wavelength λ of the noise of the main line of the compressor volute 2 at the downstream diaphragm 6 is 1 There is a half wavelength difference between the wavelength λ of the sound wave generated by the vibration of the upper and lower diaphragms of the structure-conducted silencer. Considering the interference between the two sound waves, the peaks of the two sound waves coincide with the troughs of each other, which plays a role in reducing the amplitude, thereby achieving the effect of reducing noise. For details, see Figure 3 Because this process will form a fast sound transmission channel, when the sound wave is incident from the main pipeline to the upstream diaphragm 5, it will excite the film to vibrate periodically. The lightweight rigid bifurcated rod between the two films plays the role of transmitting the sound wave, and immediately transmits the exciting sound wave of the upstream diaphragm 5 to the downstream diaphragm 6, causing it to vibrate in the same form. At this time, the time delay of the sound wave from the upstream diaphragm 5 to the downstream diaphragm 6 is almost zero (solid propagation), resulting in a certain phase difference in the sound propagation between the cavity and the main rod channel (different gas-solid propagation speeds), thereby achieving the purpose of destructive interference of sound waves, thereby achieving the effect of reducing noise.

[0040] The specific calculation is shown in the following formula. Assuming that the sound wave of the noise is λ, the path of the noise transmission from the main volute pipe is l 1 , and the path of noise transmission through the structural bypass conduction device is l 2 ,as follows Figure 5 As shown, by setting the appropriate distance between the upstream and downstream diaphragms of the bypass conduction device, the difference in different transfer paths is:

[0041]

[0042] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An airflow channel noise reduction mechanism, characterized in that: It comprises a vibrating diaphragm and a connecting rod, a plurality of the vibrating diaphragms are connected to the connecting rod, the vibrating diaphragms are located in the air outlet of the air flow channel, and the connecting rod is fixed on the air flow channel.

2. The airflow channel noise reduction mechanism according to claim 1, characterized in that: The connecting rod is provided with a plurality of supporting rods, and the end of each supporting rod is connected to one of the vibration diaphragms. The connecting rod is connected to the air flow channel through a supporting rod.

3. The airflow channel noise reduction mechanism according to claim 2, characterized in that: The support rod passes through the outer wall of the airflow channel, and the support rod is connected to the outer surface of the airflow channel.

4. The airflow channel noise reduction mechanism according to claim 1, characterized in that: The vibrating diaphragm is a lightweight diaphragm, and the material of the lightweight diaphragm includes polyvinyl chloride, polyvinylidene fluoride and polyvinyl fluoride.

5. The airflow channel noise reduction mechanism according to claim 1, characterized in that: The arrangement position of the vibrating diaphragm meets the half-wavelength silencing principle, ensuring that the sound transmission paths meet the λ is the sound wave of the hypothetical noise, l1 is the path of noise transmission from the volute main pipeline, and l2 is the path of noise transmission through the structural bypass conduction device.

6. The airflow channel noise reduction mechanism according to claim 1, characterized in that: The connecting rod is a lightweight connecting rod, and the material of the lightweight connecting rod includes aluminum alloy, fiberglass and carbon fiber.

7. The airflow channel noise reduction mechanism according to claim 1, characterized in that: The vibration diaphragm is in the shape of an ellipse, a circle, a rhombus or a regular polygon, and its area is no greater than 1 / 20 of the cross-sectional area of ​​the air flow channel.

8. The airflow channel noise reduction mechanism according to claim 1, characterized in that: The airflow channel noise reduction mechanism is evenly arranged in a plurality of groups along the axial direction and the circumferential direction of the air outlet.

9. A compressor volute with a muffler function, characterized in that: It comprises the airflow channel noise reduction mechanism as described in any one of claims 1 to 8 and a compressor volute of a turbocharger, wherein a plurality of groups of the airflow channel noise reduction mechanisms are evenly arranged on the air outlet of the compressor volute.

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