Noise reduction device and range hood

Abstract

The noise reduction device comprises an insulating shell with an opening in the front, a pore plate covering the opening of the insulating shell, and a plasma generating body arranged in the insulating shell and electrically connected with a power supply, and the plasma generating body comprises a plurality of electrode plates which are arranged in parallel and extend towards the direction of the pore plate; the thickness of the electrode plate is gradually reduced along the direction close to the pore plate, so that the edge, close to the pore plate side, of the electrode plate forms a tip. The noise reduction device is small in structure, low in corona onset voltage and long in service life.

Description

Technical Field

[0001] This utility model relates to a noise reduction device, and also to a range hood that uses the noise reduction device. Background Technology

[0002] Currently, there are two main types of noise reduction technology: passive noise reduction and active noise reduction.

[0003] Passive noise reduction technology primarily uses sound-absorbing cotton, porous materials, fiber materials, and partitions to block noise transmission, thus achieving noise reduction. Passive noise reduction is very effective for high-frequency noise because high-frequency sound waves have shorter wavelengths and are easily absorbed or reflected by materials. However, for low-frequency noise such as engine roar or noise generated by low-frequency vibrations, passive noise reduction is relatively less effective. This is because low-frequency sound waves have longer wavelengths, usually requiring thick materials or large-volume structures for effective attenuation. Therefore, passive noise reduction technology typically has the following disadvantages: large size and weight of noise reduction structures, high cost, complex installation, aesthetic limitations, and irreversibility.

[0004] Noise waves are pressure waves in the air. Active noise cancellation technology mainly consists of two types. One is anti-sonic noise cancellation technology, which collects sound waves and then generates sound waves with the same phase as the noise, thus canceling out the noise through positive and negative phase cancellation. Anti-sonic noise cancellation technology is effective in dealing with low-frequency noise in small spaces, but less effective in dealing with mid-to-high-frequency noise. Furthermore, its speakers cannot generate sound waves of arbitrary frequencies, and their frequency response range is limited by design and physical characteristics. The other type is impedance matching noise cancellation technology. Impedance matching noise cancellation technology is very sensitive and efficient in eliminating high-frequency noise, and it can also effectively eliminate low-frequency noise. Impedance matching noise cancellation technology mainly uses a plasma exciter to ionize air and generate a directional jet under the action of an electric field. This induced directional jet is used to control the airflow carrying noise, thereby reducing noise and vibration. Current plasma noise cancellation devices typically use 0.1mm diameter nichrome wire with a corona induction voltage of around 6200V. When this voltage exceeds the corona induction voltage, plasma is generated near the nichrome wire. On the one hand, the nichrome wire continuously consumes its own material after generating plasma, and since nichrome wire is relatively thin, it has a limited lifespan and requires frequent replacement. On the other hand, the high corona initiation voltage poses corresponding safety hazards, and the energy consumption during plasma generation is significant. Furthermore, the high corona initiation voltage can easily affect components in the products it is used in. Utility Model Content

[0005] The first technical problem to be solved by this utility model is to provide a noise reduction device with a compact structure, low corona initiation voltage, and long service life, in contrast to the above-mentioned prior art.

[0006] The second technical problem to be solved by this utility model is to provide a range hood that applies the aforementioned noise reduction device, in contrast to the prior art.

[0007] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: a noise reduction device, including an insulating shell with an opening at the front, and a perforated plate covering the opening of the insulating shell, characterized in that: it further includes a plasma generator disposed inside the insulating shell and electrically connected to a power source, the plasma generator including multiple parallel electrode plates extending toward the perforated plate, the thickness of the electrode plates gradually decreasing along the direction close to the perforated plate, so that the edge of the electrode plate near the perforated plate forms a sharp point.

[0008] The structure is simple, with each electrode plate electrically connected to the power supply via a single wire.

[0009] Preferably, the wire is provided with a connector for connecting to a power source.

[0010] To ensure the secure fixing of each electrode sheet, an insulating mounting base is provided inside the insulating shell for each electrode sheet, and the electrode sheet is fixed on the mounting base.

[0011] In order to form a stepped electric field and better constrain the movement direction of the generated ions, an electrode ring electrically connected to the power supply is provided inside the insulating shell. The electrode ring is located on the outer periphery of the plasma generator and between the plasma generator and the orifice plate.

[0012] To facilitate the installation of the electrode ring and to provide electric field protection for the electrode ring, a groove matching the electrode ring is provided on the front end face of the peripheral wall of the insulating shell, and the electrode ring is placed in the groove.

[0013] To effectively protect the electrode ring, an insulating layer is attached to the outside of the electrode ring.

[0014] The technical solution adopted by this utility model to solve the first technical problem mentioned above is: a range hood, characterized in that: it includes the noise reduction device as described above.

[0015] Compared with existing technologies, the advantages of this invention are as follows: The noise reduction device of this invention uses a blade-shaped structure in the plasma generator, thick on one side and thin on the other. This electrode has a large radius of curvature at its tip, requiring a lower corona initiation voltage to generate the same energy plasma flow compared to a filamentous electrode. This results in less energy consumption during operation, and the lower corona initiation voltage also has less impact on components in the noise reduction device, making it safer to use. Furthermore, while the electrode itself is consumed during ionization, its structural characteristics prevent wire breakage, improving durability against ionization losses. The electrode can maintain its thick-on-one-thin-on-one structure for a long time, significantly extending the service life of the noise reduction device. Attached Figure Description

[0016] Figure 1 This is a perspective view of the noise reduction device in the embodiment of this utility model.

[0017] Figure 2 This is an exploded perspective view of the noise reduction device in the embodiment of this utility model.

[0018] Figure 3 This is a cross-sectional view of the noise reduction device in an embodiment of this utility model.

[0019] Figure 4 This is a perspective view of the electrode sheet in an embodiment of this utility model. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0021] like Figures 1 to 3 As shown, the noise reduction device in this embodiment includes an insulating shell 1, a perforated plate 2, and a plasma generator 3.

[0022] The front side of the insulating shell 1 has an opening, forming an entrance for noise to enter. A perforated plate 2 covers this opening, with its aperture and thickness appropriately designed to allow noise to enter the insulating shell 1 through the holes. In this embodiment, the perforated plate 2 is made of stainless steel and is grounded during use.

[0023] The plasma generator 3 is installed inside the insulating shell 1 and is electrically connected to the power supply. Based on the power supply, the plasma generator 3 ionizes the air around it, thereby forming a plasma flow to process the noise entering the insulating shell 1 and achieve the purpose of active noise reduction.

[0024] In this embodiment, the plasma generator 3 includes multiple parallel electrode plates 31 extending toward the perforated plate 2. The material of the electrode plates 31 is specifically set according to needs, such as tungsten steel sheets. Figure 4 As shown, the thickness of the electrode sheet 31 gradually decreases along the direction close to the orifice plate 2, causing the edge of the electrode sheet 31 near the orifice plate 2 to form a pointed tip, i.e., the electrode sheet 31 is generally blade-shaped, and its cross-section is roughly triangular. When a higher voltage is applied to the electrode sheet 31, a high voltage is generated on the electrode sheet 31. Due to the small radius of curvature at the tip of the electrode sheet 31, its corona initiation voltage is also relatively small. Compared with the ionization effect of a filamentous electrode wire at a corona initiation voltage of 6000V, the corona initiation voltage of this electrode sheet 31 structure is about 3300V. This means lower power, less impact of high voltage on the circuit board and other components, easier achievement of the required voltage, reduced cost, and relative safety due to lower voltage.

[0025] Corona discharge typically occurs at the tip of an electrode with a small radius of curvature. When the voltage applied to electrode 31 exceeds the corona initiation voltage, the tip of electrode 31 discharges to the surrounding air, exciting and ionizing the air to produce electrons. These electrons are then accelerated in the electric field and collide with other molecules, causing an electron avalanche and ionization to produce more ions. Furthermore, the excitation, ionization, and recombination of gas atoms (or molecules) also trigger other ionization processes. In other words, plasma is generated when the applied voltage exceeds the corona initiation voltage. The thicker tail side of electrode 31, furthest from the tip, has a large radius of curvature and is generally considered unlikely to generate plasma.

[0026] During operation, since each electrode plate 31 in the plasma generator 3 needs to work, in order to facilitate the simultaneous power supply of each electrode plate 31, each electrode plate 31 is electrically connected to the power supply through a wire 4. In order to facilitate maintaining the relative position between each electrode plate 31, the wire 4 in this embodiment can be made of stainless steel. The wire 4 is also provided with a connector for connecting to the power supply to facilitate connection with a high-voltage power supply.

[0027] To further ensure the secure fixing of each electrode sheet 31, an insulating mounting base 11 is provided inside the insulating shell 1 for each electrode sheet 31. The electrode sheet 31 is fixed on the mounting base 11. The specific fixing structure of the electrode sheet 31 on the mounting base 11 is set according to the needs. For example, it can be fixed by setting a groove for tight fitting, or it can be fixed by using fasteners.

[0028] To achieve active noise reduction, the direction of the ion flow generated by ionization needs to be guided. Therefore, in this embodiment, an electrode ring 5 electrically connected to a power source is provided inside the insulating shell 1. This electrode ring 5 is located on the outer periphery of the plasma generator 3 and between the plasma generator 3 and the orifice plate 2. The voltage applied to the electrode ring 5 is different from the voltage applied to the plasma generator 3. Specifically, the voltages applied to the plasma generator 3, the electrode ring 5, and the orifice plate 2 decrease in a stepped manner, thus forming a directional stepped electric field to better constrain the movement direction of the generated ions. Under the action of the stepped electric field, the positive ions generated by the electrode plate 31 will move towards the orifice plate 2. The dense plasma will form a thick, transparent "wall." This "wall" will absorb the energy of sound, cancel out noise, and block a certain amount of sound propagation, thereby isolating noise and preventing noise leakage.

[0029] To facilitate the installation of the electrode ring 5 and to provide electric field protection for the electrode ring 5, a groove 12 matching the electrode ring 5 is provided on the front end face of the peripheral wall of the insulating shell 1. The electrode ring 5 is placed in the groove 12, and an insulating layer is attached to the outside of the electrode ring 5. This insulating layer can isolate high voltage and ensure the stability of the ion flow electric field.

[0030] The noise reduction device of this invention uses a blade-shaped structure, with one side thicker than the other, in the plasma generator 3. This electrode 31 has a large radius of curvature at its tip, requiring a lower corona initiation voltage to generate the same energy plasma flow compared to a filamentous electrode. This results in lower energy consumption during operation and reduces the impact on components in the noise reduction device, thus enhancing its safety. Furthermore, while the electrode 31 itself experiences wear during ionization, its structural characteristics prevent wire breakage, improving durability against ionization wear. The electrode 31 maintains its one-sided thickness and thin-on-one shape for an extended period, significantly extending the lifespan of the noise reduction device.

[0031] This utility model also relates to a range hood, including the aforementioned noise reduction device, which can effectively reduce the noise of the range hood during operation and improve the user experience.

[0032] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of the invention. However, the use of these terms is merely for illustrative purposes and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this invention can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A noise reduction device, comprising an insulating shell (1) with an opening at the front, and a perforated plate (2) covering the opening of the insulating shell (1), characterized in that: It also includes a plasma generator (3) disposed inside the insulating shell (1) and electrically connected to the power supply. The plasma generator (3) includes multiple parallel electrode plates (31) extending toward the orifice plate (2). The thickness of the electrode plates (31) gradually decreases along the direction close to the orifice plate (2), so that the edge of the electrode plates (31) close to the orifice plate (2) forms a sharp point.

2. The noise reduction device according to claim 1, characterized in that: Each electrode (31) is electrically connected to the power supply via a wire (4).

3. The noise reduction device according to claim 2, characterized in that: The conductor (4) is provided with a connector for connecting to a power source.

4. The noise reduction device according to any one of claims 1 to 3, characterized in that: The insulating shell (1) has an insulating mounting base (11) corresponding to each electrode piece (31), and the electrode piece (31) is fixed on the mounting base (11).

5. The noise reduction device according to any one of claims 1 to 3, characterized in that: The insulating shell (1) is provided with an electrode ring (5) that is electrically connected to the power supply. The electrode ring (5) is located on the outer periphery of the plasma generator (3) and between the plasma generator (3) and the orifice plate (2).

6. The noise reduction device according to claim 5, characterized in that: The front end face of the peripheral wall of the insulating shell (1) is provided with a groove (12) that matches the electrode ring (5), and the electrode ring (5) is disposed in the groove (12).

7. The noise reduction device according to claim 5, characterized in that: An insulating layer is attached to the outside of the electrode ring (5).

8. A range hood, characterized in that: Includes the noise reduction device as described in any one of claims 1 to 7.

Images