Noise reduction blower

Abstract

The utility model relates to the technical field of hair driers, in particular to a noise reduction hair drier which comprises a shell and an air duct arranged in the shell, a noise reduction piece is arranged at the air inlet end of the air duct, a noise reduction cavity for airflow to flow through is formed in the noise reduction piece, a plurality of flexible protruding parts are arranged on the inner wall of the noise reduction piece, and a noise absorption groove is formed between every two adjacent protruding parts. Noise is blocked by the protrusions and is reflected and consumed in the sound absorption grooves. The periphery of the air flow is mainly in contact with the flexible upheaval part, so that air oscillation noise caused by viscosity between the rigid inner wall of the silencing piece and the air flow and noise generated when turbulent flow hits the rigid inner wall of the silencing piece are reduced and even eliminated; when the protruding parts make contact with airflow, noise is reduced through self-buffering vibration absorption, the noise transmitted into the sound absorption grooves is continuously reflected and consumed under blocking of the protruding parts, the flexible protruding parts are used for absorbing air vibration of the noise through self-buffering vibration absorption, and therefore sound energy is converted into heat energy, absorption of noise sound waves is achieved, and the noise reduction effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hair dryers, in particular to a noise-reducing hair dryer. Background Art

[0002] The airflow at the air inlet of a high-speed hair dryer is relatively turbulent, which can cause a lot of noise. Therefore, existing high-speed hair dryers usually have a silencer at the air inlet to reduce the noise of the airflow when it flows through the silencer. It can be considered that a silencer chamber is formed in the silencer. However, when the high-speed airflow flows through the silencer chamber, it contacts the rigid inner wall of the silencer, and the high viscosity between them generates shear force, causing air vibration and turbulence to hit the rigid inner wall of the silencer, thereby causing additional noise and weakening the noise reduction effect of the silencer. Utility Model Content

[0003] The present invention aims to improve upon the problems existing in the prior art. Specifically, the present invention aims to provide a noise-reducing hair dryer capable of reducing noise in a silencer cavity of a silencer disposed at an air inlet end of an air duct.

[0004] The noise reduction hair dryer of the utility model comprises a shell and an air duct arranged in the shell, a silencer is provided at the air inlet end of the air duct, a silencer cavity is provided in the silencer for air flow to flow through, a plurality of flexible protrusions are provided on the inner wall of the silencer, and sound absorbing grooves are formed between adjacent protrusions so that noise is blocked by the protrusions and reflected and consumed in the sound absorbing grooves.

[0005] In one embodiment, a plurality of block-shaped protrusions are independently provided and arranged in a mesh shape to form a plurality of sound absorbing grooves arranged in a mesh shape.

[0006] In one embodiment, a plurality of strip-shaped protrusions are arranged side by side to form a plurality of strip-shaped sound absorbing grooves arranged side by side, or a plurality of strip-shaped protrusions are arranged alternately to form a plurality of discretely arranged sound absorbing grooves in a mesh shape.

[0007] In one embodiment, the plurality of block-shaped protrusions are arranged in a plurality of rows, and in each row of protrusions, there are a plurality of groups of protrusions arranged along the direction of airflow in the silencer chamber, and each group of protrusions includes at least two protrusions, so that the sound absorbing groove is formed between two adjacent groups of protrusions and / or between two adjacent protrusions in each group of protrusions.

[0008] In one embodiment, among the multiple groups of protrusions in each column of protrusions, at least two protrusions in each group of protrusions are arranged along the airflow direction in the silencer chamber, so that the front and rear sides of the sound absorbing groove along the airflow direction in the silencer chamber are blocked by the protrusions.

[0009] In one embodiment, among the multiple groups of protrusions in each column of protrusions, at least two protrusions in any one group of protrusions are arranged along the airflow direction in the silencer chamber or along the circumference of the silencer chamber, and the protrusions in any two adjacent groups of protrusions are arranged in different ways, so that part of the sound absorbing grooves are blocked by the protrusions on both sides of the airflow direction in the silencer chamber and on both sides of the circumference of the silencer chamber.

[0010] In one embodiment, any two adjacent rows of protrusions are overlapped or staggered.

[0011] In one embodiment, the width of the raised portion decreases from the inner wall of the muffler toward the central axis of the muffler cavity, so that the width of the sound absorbing groove increases from the inner wall of the muffler toward the central axis of the muffler cavity.

[0012] In one embodiment, the raised portion converges from the bottom of the inner wall of the silencer toward the central axis of the silencer chamber to a vertex, an edge or a top surface, and the top surface is parallel to the flow direction of the airflow in the air duct to reduce the contact area between the airflow in the silencer chamber and the raised portion.

[0013] In one embodiment, the raised portion is disposed at the bottom of the inner wall of the muffler and is rectangular, so that four side walls facing different directions are formed around the raised portion.

[0014] Beneficial effects:

[0015] 1) On the one hand, the periphery of the airflow is mainly in contact with the flexible ridges to reduce or even completely avoid the contact between the airflow and the rigid inner wall of the silencer, thereby reducing or even eliminating the air vibration noise caused by the viscosity between the rigid inner wall of the silencer and the airflow and the noise of turbulence hitting the rigid inner wall of the silencer; on the other hand, when the ridges are in contact with the airflow, they can reduce the noise by their own buffering and vibration absorption. The noise generated by the airflow itself is transmitted into the sound-absorbing groove and is continuously reflected and consumed under the obstruction of the ridges. The flexible ridges absorb the air vibration of the noise through their own buffering and vibration absorption, thereby converting the sound energy into heat energy, realizing the absorption of noise sound waves, and improving the noise reduction effect.

[0016] 2) In one embodiment of the utility model, a plurality of block-shaped protrusions are arranged in a mesh to form a plurality of sound-absorbing grooves arranged in a mesh. Any protrusion can form a sound-absorbing groove with the other protrusions around it. This not only increases the number of sound-absorbing grooves and reduces the space of the sound-absorbing grooves, but also improves the encirclement effect of the protrusions on the sound-absorbing grooves, further improving the noise reduction effect.

[0017] 3) In one embodiment of the utility model, multiple groups of raised portions in each column of raised portions are arranged along the flow direction of the airflow in the silencer chamber, so that the sound-absorbing grooves formed in each column of raised portions are also arranged along the flow direction of the airflow in the silencer chamber, so that the sound-absorbing grooves formed in each column of raised portions are always accompanied by the airflow flowing through the silencer chamber, and the noise generated by the airflow in the silencer chamber can enter the nearby sound-absorbing grooves at any time, thereby improving the noise absorption efficiency of the sound-absorbing grooves, thereby improving the noise reduction effect.

[0018] 4) In one embodiment of the utility model, any two adjacent columns of raised parts are overlapped or staggered, so that the two adjacent columns of raised parts are combined with each other to form a new sound-absorbing groove and / or the sound-absorbing groove formed in each column of raised parts has an enhanced effect of trapping noise, thereby further enhancing the noise reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the embodiments of the present application, the drawings required for use in the embodiments of the present application are briefly introduced below.

[0020] Figure 1 is a schematic diagram of a raised portion provided on the inner wall of a muffler and a sound absorbing groove formed therein;

[0021] Figure 2 A schematic diagram of a silencer disposed at an air inlet end of an air duct in a housing;

[0022] Figure 3 A schematic diagram of a first embodiment of a protrusion arrangement method;

[0023] Figure 4 is a schematic diagram of a second embodiment of the arrangement of the raised portions;

[0024] Figure 5 for Figure 4 A cross-sectional view of

[0025] Figure 6 is a schematic diagram showing that the raised portion is conical;

[0026] Figure numerals: 1. shell, 11. air inlet, 12. air outlet, 2. air duct, 3. silencer, 31. silencer chamber, 4. raised portion, 41. sound-absorbing groove, 42. vertical channel, 5. fan. DETAILED DESCRIPTION

[0027] The following specific embodiments are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, as long as they are within the scope of the claims of the present application, they are protected by the patent law.

[0028] Figure 1A specific embodiment of a noise-reducing hair dryer of the utility model is shown, comprising a shell 1 and an air duct 2 arranged in the shell 1, a silencer 3 is provided at the air inlet end of the air duct 2, and a silencer cavity 31 for air flow to flow through is provided in the silencer 3, a plurality of flexible protrusions 4 are provided on the inner wall of the silencer 3, and sound-absorbing grooves 41 are formed between adjacent protrusions 4, so that the noise is blocked by the protrusions 4 and reflected and consumed in the sound-absorbing grooves 41; wherein, the inner wall of the silencer 3 forms a silencer cavity 31 which passes through along its own central axis direction, and the airflow in the air inlet end of the air duct 2 is an initial airflow formed by the air entering the air duct 2 from outside the shell 1, so this part of the airflow is still in a relatively turbulent state, which will generate relatively large noise, and therefore the silencer 3 is provided at the air inlet end of the air duct 2 to reduce the noise. In the present invention, a plurality of flexible ridges 4 are provided on the inner wall of the muffler 3, and sound absorbing grooves 41 are formed between adjacent ridges 4. The ridges 4 and the sound absorbing grooves 41 together form an uneven pleated structure on the inner wall of the muffler 3. The pleated structure actually occupies part of the space in the muffler cavity 31 close to the inner wall of the muffler 3. When the airflow at the air inlet end of the air duct 2 flows through the muffler cavity 31 in the muffler 3, it can be considered that the airflow mainly flows in the channel surrounded by the ridges 4. On the one hand, the outer periphery of the airflow mainly contacts the flexible ridges 4, so as to reduce or even completely avoid the contact between the airflow and the rigid inner wall of the muffler 3. On the other hand, when the ridge 4 contacts the airflow, it can reduce the noise by its own buffering and vibration absorption. For the noise generated by the airflow itself, such as the noise generated by its own turbulence, it is transmitted into the sound-absorbing groove 41 and is continuously reflected and consumed under the obstruction of the ridge 4. The flexible ridge 4 absorbs the air vibration of the noise by its own buffering and vibration absorption, thereby converting the sound energy into heat energy, realizing the absorption of noise sound waves and improving the noise reduction effect. In addition, in the muffler cavity 31 of the present invention, the high-speed airflow mainly flows in the space surrounded by the ridge 4, and the noise generated by the airflow is transmitted using air as a vibration medium. When the noise is transmitted to the sound-absorbing groove 41, the air in the sound-absorbing groove 41 vibrates and generates noise. At this time, since the high-speed airflow flows at high speed outside the sound-absorbing groove 41, the space in the sound-absorbing groove 41 is a low-pressure area around the high-speed airflow. The air flow trend in the sound-absorbing groove 41 is to flow from the high-speed airflow into the sound-absorbing groove 41, that is, the vibrating air in the sound-absorbing groove 41 is difficult to flow back into the high-speed airflow. Most of the sound waves transmitted into the sound-absorbing groove 41 are trapped in the sound-absorbing groove 41 and continuously reflected until they are completely consumed, thereby reducing the possibility of noise being transmitted out of the sound-absorbing groove 41, and further improving the noise reduction effect. It can be understood that when the inner wall of the muffler 3 is completely covered by the ridge 4, the contact between the airflow and the rigid inner wall of the muffler 3 can be completely avoided. When the inner wall of the muffler 3 is not completely covered by the ridge 4, the rigid inner wall of the muffler 3 may still contact the airflow.The material of the flexible ridge 4 can be polyurethane material, such as sponge, silicone, etc., which has an internal air gap, so that part of the noise sound waves can be directly transmitted into the internal gap of the ridge 4 for reflection and consumption, further improving the noise reduction effect. It can be understood that in this embodiment, the housing 1 is also provided with a fan 5 for driving the air flow, and the housing 1 is provided with an air inlet 11 and an air outlet 12 connected to the air duct 2.

[0029] The raised portion 4 and the sound absorbing groove 41 in the present invention jointly form an uneven pleated structure facing the side of the high-speed airflow. The specific pleat shapes are varied, mainly depending on the structural shape and arrangement of the raised portion 4. It can be understood that the sound absorbing groove 41 is a semi-closed structure, which is open to the side of the high-speed airflow in the silencer chamber 31 for noise to enter, and the side wall of the sound absorbing groove 41 can be fully closed or semi-closed, depending on the shape and arrangement of the raised portion 4. However, even if the side wall of the sound absorbing groove 41 is semi-closed, the noise overflowing from the gap in the side wall of the sound absorbing groove 41 is still in the pleated structure, and will enter the remaining sound absorbing grooves 41 to continue to be reflected and consumed.

[0030] In one embodiment, the raised portion 4 is strip-shaped, and a plurality of strip-shaped raised portions 4 are arranged side by side to form a plurality of strip-shaped sound absorbing grooves 41 arranged side by side, wherein the strip-shaped raised portions 4 may be continuous or discontinuous. The arrangement of the strip-shaped protrusions 4 in this embodiment can be specifically divided into the following three implementation modes. In the first implementation mode, the strip-shaped protrusions 4 all extend along the central axis direction of the silencer chamber 31, that is, extend along the airflow direction in the silencer chamber 31, then a plurality of strip-shaped protrusions 4 are arranged side by side along the circumference of the silencer chamber 31, and the extension direction of the formed sound-absorbing grooves 41 is consistent with the extension direction of the protrusions 4. Since the sound-absorbing grooves 41 are connected along the airflow direction in the silencer chamber 31, the air in the sound-absorbing grooves 41 can easily leave the sound-absorbing grooves 41 with the airflow, thereby weakening the noise reduction effect. In the second implementation mode, the strip-shaped protrusions 4 all extend along the circumference of the silencer chamber 31, and can even form a ring surrounding the silencer chamber 31. The formed sound-absorbing grooves 41 also extend along the circumference of the silencer chamber 31. At this time, the front and rear sides of the sound absorbing groove 41 along the airflow direction in the silencer cavity 31 are blocked by the ridges 4, and it is not easy to leave the sound absorbing groove 41 with the airflow, which has a better effect on the noise trapping. However, a single sound absorbing groove 41 is connected along the circumferential direction of the silencer cavity 31, so that its own space is larger, and the frequency of noise reflection therein decreases, which will also weaken the noise reduction effect to a certain extent. In the third embodiment, the strip-shaped ridges 4 are all in an inclined state with an angle with the central axis of the silencer cavity 31, and the formed sound absorbing grooves 41 are also in an inclined state consistent with the ridges 4. The effect of trapping the noise in the sound absorbing groove 41 is slightly worse than that of the second embodiment, but the space of a single sound absorbing groove 41 is reduced, which can increase the reflection frequency of noise compared with the second embodiment.

[0031] In one embodiment, the raised portion 4 is in a strip shape, and a plurality of strip-shaped raised portions 4 are staggered to form a plurality of sound-absorbing grooves 41 that are discretely arranged in a mesh shape. In this way, the space of the sound-absorbing groove 41 can be reduced, and each sound-absorbing groove 41 is blocked by the raised portions 4 on all sides, which not only improves the noise trapping effect of the sound-absorbing groove 41, but also increases the reflection frequency of the noise in the sound-absorbing groove 41, further improving the noise elimination effect of the sound-absorbing groove 41, thereby improving the noise reduction effect.

[0032] In one embodiment, if Figure 1 As shown, the ridges 4 are in the form of independent blocks, and multiple block-shaped ridges 4 are arranged in a mesh. Sound-absorbing grooves 41 are formed between adjacent ridges 4, so multiple sound-absorbing grooves 41 arranged in a mesh are formed. In this embodiment, the ridges 4 are in the form of isolated blocks, and any ridge 4 can form a sound-absorbing groove 41 with the remaining ridges 4 around, so that the formed sound-absorbing groove 41 is surrounded by two or more ridges 4 around. In this way, the number of sound-absorbing grooves 41 is increased, the space of the sound-absorbing grooves 41 is reduced, and the siege effect of the ridges 4 on the sound-absorbing grooves 41 is increased, further improving the noise reduction effect. In this embodiment, the arrangement of the ridges 4 can be disordered or uniform and orderly, and can be spliced ​​without spacing at the bottom or spaced from each other.

[0033] In one embodiment, the raised portions 4 are in the form of blocks that are independently arranged, and a plurality of block-shaped raised portions 4 are arranged in a plurality of rows on the inner wall of the muffler 3, and in each row of raised portions 4 there are a plurality of groups of raised portions 4 arranged along the airflow direction in the muffler chamber 31, and each group of raised portions 4 includes at least two raised portions 4, so that the sound absorbing groove 41 is formed between two adjacent groups of raised portions 4 and / or between two adjacent groups of raised portions 4 in each group of raised portions 4. In this embodiment, the protrusions 4 are arranged in multiple rows, and multiple groups of protrusions 4 are arranged in each row of protrusions 4, so as to improve the uniformity of arrangement of the protrusions 4 in each row, thereby improving the uniformity of arrangement of the sound absorbing grooves 41 in each row, so that the sound absorbing grooves 41 cover various areas of the inner wall of the muffler 3, and improve the noise reduction effect. It is further preferred that the multiple rows of protrusions 4 are evenly arranged side by side along the circumference of the muffler 3; and in this embodiment, the multiple groups of protrusions 4 in each row of protrusions 4 are arranged along the flow direction of the airflow in the muffler cavity 31, so that the sound absorbing grooves 41 formed in each row of protrusions 4 are also arranged along the flow direction of the airflow in the muffler cavity 31. In this way, the sound absorbing grooves 41 formed in each row of protrusions 4 are always accompanied by the airflow flowing through the muffler cavity 31, and the noise generated by the airflow in the muffler cavity 31 can enter the nearby sound absorbing grooves 41 at any time, thereby improving the noise absorption efficiency of the sound absorbing grooves 41, thereby improving the noise reduction effect. In addition, part of the airflow on the periphery of the high-speed airflow deviates from the original direction of travel and travels toward the inner wall of the silencer 3. This part of the airflow enters the sound absorbing groove 41 to form turbulence. Although the direction of travel of this part of the airflow is deviated to a certain extent, the overall flow trend is still along the original direction of travel. In this embodiment, the multiple groups of protrusions 4 in each column of protrusions 4 are arranged along the flow direction of the airflow in the silencer cavity 31. Therefore, for the turbulence formed in the sound absorbing groove 41, the protrusions 4 located in its direction of travel can play a blocking role, reducing the possibility of the turbulence continuing to leave the sound absorbing groove 41 along the original direction of travel, thereby reducing the overflow of noise and further improving the noise reduction effect. It can be understood that, in the multiple groups of raised portions 4 in each column of raised portions 4 of the present embodiment, there may be some groups of raised portions 4 in which two or more sound absorbing grooves 41 formed between adjacent raised portions 4 are not arranged along the airflow direction in the silencer cavity 31, but this does not affect the overall arrangement of the sound absorbing grooves 41 formed in each column of raised portions 4 along the airflow direction in the silencer cavity 31, and the raised portions 4 arranged in this way have a poor effect of blocking the noise in the sound absorbing grooves 41, and the noise can easily overflow the sound absorbing grooves 41 with the high-speed airflow.

[0034] Based on the above embodiment in which multiple groups of ridges 4 are arranged along the airflow direction in the muffler chamber 31 in each row of ridges 4, an improved embodiment is obtained. Figure 3It is shown that, among the multiple groups of protrusions 4 in each column of protrusions 4, at least two protrusions 4 in each group of protrusions 4 are arranged along the airflow direction in the silencer chamber 31, so that all the protrusions 4 in each column of protrusions 4 are arranged along the airflow direction in the silencer chamber 31, and the sound absorbing groove 41 formed between two adjacent groups of protrusions 4 and the sound absorbing groove 41 formed between two adjacent protrusions 4 in each group of protrusions 4 are formed by two protrusions 4 on the front and rear sides along the airflow direction in the silencer chamber 31, that is, the sound absorbing groove 41 is blocked by the protrusions 4 on the front and rear sides along the airflow direction in the silencer chamber 31, so that the blocking ability of the protrusions 4 to the noise in the sound absorbing groove 41 can be effectively improved, and the possibility of noise overflowing the sound absorbing groove 41 with high-speed airflow can be effectively reduced, thereby further improving the noise reduction effect.

[0035] Based on the above embodiment in which multiple groups of ridges 4 are arranged along the airflow direction in the muffler cavity 31 in each row of ridges 4, another improved embodiment is obtained. Figure 4 It is shown that, in the multiple groups of ridges 4 in each column of ridges 4, at least two ridges 4 in any group of ridges 4 are arranged along the airflow direction in the muffler cavity 31 or along the circumference of the muffler cavity 31, and the ridges 4 in any two adjacent groups of ridges 4 are arranged in different ways, that is, when at least two ridges 4 in one group of ridges 4 are arranged along the airflow direction in the muffler cavity 31, then at least two ridges 4 in one or two groups of ridges 4 adjacent to the group of ridges 4 are arranged along the circumference of the muffler cavity 31. In other words, in each column of ridges 4, a combination of ridges 4 arranged along the airflow direction in the muffler cavity 31 and a combination of ridges 4 arranged along the circumference of the muffler cavity 31 are alternately arranged to form a column of ridges 4; wherein, for a group of ridges 4 arranged along the circumference of the muffler cavity 31, the sound absorbing grooves 41 formed by them are arranged along the muffler cavity 31. The front and rear sides of the sound cavity 31 in the circumferential direction are blocked by two adjacent ridges 4 of the same group, and the front and rear sides of the sound absorbing groove 41 along the airflow direction in the sound-absorbing cavity 31 are blocked by two adjacent groups of ridges 4, thereby jointly forming a sound absorbing groove 41 with higher sealing, further improving the noise trapping effect of the sound absorbing groove 41, reducing the possibility of noise propagation outside the sound absorbing groove 41, and further improving the noise reduction effect; and for a group of ridges 4 arranged along the airflow direction in the sound-absorbing cavity 31, the sound absorbing groove 41 formed by it is blocked by two adjacent ridges 4 of the same group on the front and rear sides along the airflow direction in the sound-absorbing cavity 31, and the noise reduction effect is the same as the noise reduction effect of the sound absorbing groove 41 formed by all the ridges 4 in each column of ridges 4 arranged along the airflow direction in the sound-absorbing cavity 31 in the previous embodiment.

[0036] Furthermore, for the embodiments in which the above-mentioned three raised portions 4 are arranged in multiple rows, further improvements can be made so that any two adjacent rows of raised portions 4 are overlapped or staggered, so that the two adjacent rows of raised portions 4 are combined with each other to form a new sound-absorbing groove 41 and / or the noise-trapping effect of the sound-absorbing groove 41 formed in each row of raised portions 4 is enhanced. The specific embodiments and technical effects of this improvement are mainly described based on the latter two embodiments in the above-mentioned embodiments.

[0037] For the embodiment in which at least two ridges 4 in each group of ridges 4 are arranged along the airflow direction in the muffler chamber 31, any two adjacent rows of ridges 4 are overlapped to obtain the first improved embodiment, and any two adjacent rows of ridges 4 along the circumference of the muffler chamber 31 overlap, so that any two adjacent ridges 4 along the circumference of the muffler chamber 31 correspond to each other and form a sound absorbing groove 41, which is formed between two adjacent rows of ridges 4. When noise enters the sound absorbing groove 41, the noise can also be reflected and consumed therein. However, in this embodiment, the multiple sound absorbing grooves 41 formed between adjacent rows are connected along the airflow direction in the muffler chamber 31 to form a vertical channel 42, and the sound absorbing grooves 41 in each row are connected along the airflow direction in the muffler chamber 31 to form a vertical channel 42, and the sound absorbing grooves 41 in each row are connected along the airflow direction in the muffler chamber 31. 1 circumferentially corresponds to the sound absorbing grooves 41 in adjacent columns, so that the sound absorbing grooves 41 in each column are connected with the sound absorbing grooves 41 in the remaining columns corresponding to the sound absorbing grooves 41 along the circumferential direction of the sound absorbing cavity 31 to form a ring around the circumference of the sound absorbing cavity 31, so that there is no single sound absorbing groove 41 with a small volume in the entire pleated structure formed by all the ridges 4 and the sound absorbing grooves 41, the noise propagates in the interconnected sound absorbing grooves 41, the reflection frequency of the noise decreases, and the noise absorption efficiency of the ridges 4 is also reduced, especially the multiple sound absorbing grooves 41 formed between adjacent columns and connected to form a vertical channel 42 along the airflow direction in the sound absorbing cavity 31, most of the noise entering therein is easy to leave the sound absorbing groove 41 with the flow of high-speed airflow, which is not conducive to noise reduction.

[0038] For the embodiment in which at least two protrusions 4 in each group of protrusions 4 are arranged along the airflow direction in the muffler cavity 31, any two adjacent rows of protrusions 4 are staggered to obtain a second improved embodiment, such as Figure 3As shown, any two adjacent rows of raised portions 4 are staggered along the circumference of the sound-absorbing cavity 31, and the front and rear openings of each sound-absorbing groove 41 formed in each row of raised portions 4 along the circumference of the sound-absorbing cavity 31 correspond to the raised portions 4 in the adjacent row along the circumference of the sound-absorbing cavity 31, respectively, so that the openings of the sound-absorbing groove 41 on both sides along the circumference of the sound-absorbing cavity 31 are blocked by the raised portions 4. In this way, each sound-absorbing groove 41 in each row is composed of two raised portions 4 in the same row and two raised portions 4 in the adjacent rows on both sides, so that the circumferential sealing of the sound-absorbing groove 41 is improved, thereby improving the noise trapping effect of the sound-absorbing groove 41 and the noise in the sound-absorbing groove. 41, thereby improving the absorption efficiency of the ridges 4 on noise and improving the noise reduction effect; it can be understood that, although the sound absorbing groove 41 in the present embodiment is composed of four ridges 4 to improve the sealing of the sides of the sound absorbing groove 41, it does not mean that the sides of the sound absorbing groove 41 are completely closed, and there can still be gaps between the ridges 4, that is, there can still be outlets on the sides of the sound absorbing groove 41. For example, when the ridges 4 are in a cone structure, there must be gaps between the four ridges 4 around a single sound absorbing groove 41, but a larger area of ​​the sound absorbing groove 41 in four main directions is blocked by the ridges 4 to improve the noise trapping effect. Moreover, in the present embodiment, the vertical channels 42 formed between the protrusions 4 of adjacent columns are also directly connected to the sound absorbing grooves 41 of adjacent columns along the circumference of the sound absorbing cavity 31, becoming a part of the extension of the sound absorbing grooves 41 in the adjacent columns, and no longer serving as a sound absorbing space independent of the sound absorbing grooves 41 of each column. At this time, even if the vertical channels 42 between adjacent columns still pass through along the airflow direction in the sound absorbing cavity 31, most of the noise sound waves entering the space will be reflected into the sound absorbing grooves 41 after hitting the protrusions 4, thereby reducing the noise leaving the sound absorbing grooves 41 along the airflow direction and improving the noise reduction effect.

[0039] For the above-mentioned embodiment in which a row of ridges 4 is formed by alternating the combination of ridges 4 arranged along the airflow direction in the muffler cavity 31 in each row of ridges 4 and the combination of ridges 4 arranged along the circumference of the muffler cavity 31, any two adjacent rows of ridges 4 are overlapped to obtain the first improved embodiment, and any two adjacent rows of ridges 4 are overlapped along the circumference of the muffler cavity 31, and each group of ridges 4 arranged along the circumference of the muffler cavity 31 in each row of ridges 4 can still form a sound-absorbing groove with better sealing performance with the two groups of ridges 4 adjacent to each other in the same row. 41, regardless of the arrangement of the ridges 4 in adjacent columns, the sound absorbing grooves 41 formed in each group of ridges 4 arranged along the airflow direction in the silencer cavity 31 in each column correspond to and are connected with the sound absorbing grooves 41 formed in the group of ridges 4 arranged along the airflow direction in the silencer cavity 31 in the remaining columns along the circumferential direction of the silencer cavity 31, forming a ring along the circumferential direction of the silencer cavity 31, so that the noise entering these sound absorbing grooves 41 propagates in the entire annular space, and the reflection frequency of the noise therein is low, which will weaken the noise absorption efficiency of the ridges 4.

[0040] For the above-mentioned embodiment in which the combination of the ridges 4 arranged along the airflow direction in the muffler cavity 31 in each row of ridges 4 and the combination of the ridges 4 arranged along the circumference of the muffler cavity 31 are alternately arranged to form a row of ridges 4, any two adjacent rows of ridges 4 are staggered to obtain a second improved embodiment, such as Figure 5 It is shown that each group of ridges 4 arranged along the airflow direction in the silencer cavity 31 in each column corresponds to a group of ridges 4 arranged along the circumference of the silencer cavity 31 in an adjacent column, so that the front and rear openings of the sound absorbing grooves 41 formed in each group of ridges 4 arranged along the airflow direction in the silencer cavity 31 in each column are blocked by the ridges 4 in the adjacent column, so that these sound absorbing grooves 41 are blocked by the ridges 4 in four directions, thereby improving the sealing of the sides of the sound absorbing grooves 41, thereby improving the noise trapping effect of the sound absorbing grooves 41 and the reflection frequency of the noise in the sound absorbing grooves 41, and improving the noise absorption effect of the ridges 4, thereby improving the noise reduction effect. In the present embodiment, each group of protrusions 4 arranged circumferentially along the silencer chamber 31 in each column of protrusions 4 can still form a well-enclosed sound-absorbing groove 41 with two front-to-rear adjacent groups of protrusions 4 in the same column. In this way, each sound-absorbing groove 41 formed in each column of protrusions 4 in the present embodiment has a good effect of trapping noise, thereby improving the noise reduction effect.

[0041] Furthermore, in one embodiment, the width of the ridge 4 decreases from the inner wall of the silencer 3 toward the central axis of the silencer chamber 31, and the sound absorbing groove 41 is formed by adjacent ridges 4, so that the width of the sound absorbing groove 41 can be increased from the inner wall of the silencer 3 toward the central axis of the silencer chamber 31. In this way, on the one hand, the opening of the sound absorbing groove 41 toward the side of the airflow flowing in the silencer chamber 31 can be increased, so that the noise in the silencer chamber 31 can be more easily transmitted into the sound absorbing groove 41, thereby improving the noise reduction ability of the sound absorbing groove 41; on the other hand, since the noise sound waves transmitted into the sound absorbing groove 41 generally move toward the inner wall of the silencer chamber 31, they are continuously reflected between the ridges 4 around the sound absorbing groove 41 during the moving process, the closer the noise sound waves are to the inner wall of the silencer chamber 31, the narrower the spacing between adjacent ridges 4, the higher the reflection frequency of the noise sound waves, and the higher the absorption efficiency of the noise sound waves by the ridges 4, thereby improving the noise reduction effect.

[0042] Furthermore, in one embodiment, the ridge 4 converges from the bottom of the inner wall of the muffler 3 toward the central axis of the muffler cavity 31 to a vertex, an edge or a top surface, and the top surface is parallel to the flow direction of the airflow in the air duct 2 to reduce the contact area between the airflow in the muffler cavity 31 and the ridge 4. In this embodiment, Figure 3As shown, the raised portion 4 converges at a vertex from the bottom of the inner wall of the muffler 3 toward the central axis of the muffler chamber 31, that is, the top of the raised portion 4 facing the airflow flowing in the muffler chamber 31 is a vertex, so that the raised portion 4 is a cone structure, including a cone, a pyramid, an elliptical cone, etc.; Figure 4 As shown, the raised portion 4 converges to an edge from the bottom of the inner wall of the silencer chamber 31 toward the central axis of the silencer chamber 31, that is, the top of the raised portion 4 facing the side of the airflow flowing in the silencer chamber 31 is an edge, so that the raised portion 4 is wedge-shaped; the raised portion 4 converges to a top surface from the bottom of the inner wall of the silencer chamber 31 toward the central axis of the silencer chamber 31, and the top surface is parallel to the flow direction of the airflow in the silencer chamber 31, that is, the top of the raised portion 4 facing the side of the airflow flowing in the silencer chamber 31 is a top surface, and the shape of the top surface is not limited, and can be an arc, a straight line, etc., but the top surface is a straight line along the flow direction of the airflow in the silencer chamber 31 to reduce the obstruction to the airflow. Although the top of the raised portion 4 in this embodiment is a single surface, based on the fact that the raised portion 4 converges to a top surface from the inner wall of the silencer chamber 31 toward the central axis of the silencer chamber 31, it can be understood that the area of ​​the top surface is smaller, preferably close to an edge, so that the raised portion 4 is also wedge-shaped. The raised portion 4 in the silencer chamber 31 occupies the space near the inner wall of the silencer chamber 31, so most of the airflow flows through the space enclosed by the raised portion 4, specifically, the area enclosed by the top of all the raised portions 4 facing the side of the flowing airflow in the silencer chamber 31, in which the main body of the airflow flows normally, and only part of the turbulence on the periphery of the airflow may enter the sound absorbing groove 41, so only the top of the raised portion 4 is in contact with the normally flowing airflow; the above three implementation methods of this embodiment can fully reduce the contact area between the top of the raised portion 4 and the flowing airflow in the silencer chamber 31, effectively reduce the friction between the raised portion 4 and the flowing airflow in the silencer chamber 31, reduce the generation of turbulence in the flowing airflow in the silencer chamber 31 and the loss of flow velocity, thereby reducing noise. Moreover, when the raised portion 4 is in a cone structure or a wedge shape, if the material of the raised portion 4 is a flexible material with an internal air gap, such as a polyurethane material such as sponge or silicone, which itself has an internal air gap, part of the noise sound waves can be directly transmitted into the internal gap of the raised portion 4 for reflection and consumption, thereby being able to bring into play the gradual transition property of the raised portion 4, thereby improving the noise absorption efficiency of the raised portion 4.

[0043] Based on the above-mentioned embodiment in which the raised portion 4 is arranged from the bottom of the inner wall of the muffler 3 toward the central axis of the muffler cavity 31 and converges to a vertex, an edge or a top surface, an improved embodiment is obtained, such as Figure 6As shown, the raised portion 4 is arranged at the bottom of the inner wall of the silencer 3 and is rectangular, so that four side walls facing different directions are formed on the outer periphery of the raised portion 4, including the raised portion 4 being a pyramid structure, a cone structure, a prism structure, etc. It can be understood that the circumference of the cone structure is an integral cone surface, which can also be divided into four parts facing four different directions, and because the inner wall of the silencer 3 may be arc-shaped, the bottom surface of the raised portion 4 also needs to be adaptively arc-shaped, but the bottom surface contour of the raised portion 4 is still rectangular, so that the raised portion 4 can use its own four side walls in different directions to block different sound absorbing grooves 41 formed around itself. For the sound absorbing groove 41, it is blocked from the front in four directions around it, and the blocking area is large, which improves the blocking effect on noise sound waves, reduces the possibility of noise leaving the sound absorbing groove 41, and makes most of the noise reflected and consumed in the sound absorbing groove 41, thereby improving the noise reduction effect. More specifically, in combination with the above-mentioned embodiment in which a plurality of raised portions 4 are arranged in a plurality of rows, part of the sound absorbing grooves 41 need to be blocked by four raised portions 4 from four directions respectively, and the four directions include the front and rear sides along the airflow direction in the muffler cavity 31 and the front and rear sides along the circumference of the muffler cavity 31. Therefore, when the raised portion 4 has four side walls facing the surroundings respectively, the four sound absorbing grooves 41 formed around itself can be well blocked respectively, thereby improving the noise trapping effect of the sound absorbing grooves 41; When the ridges 4 are specifically arranged, the four sides of the rectangular bottom surface of the ridges 4 correspond to the above four directions, two of which extend along the circumference of the silencer chamber 31, and two extend along the flow direction of the airflow in the silencer chamber 31. This is also conducive to the seamless splicing of adjacent ridges 4 along the circumference of the silencer chamber 31 and the flow direction of the airflow in the silencer chamber 31, so that the area on the inner wall of the silencer 3 where the ridges 4 are arranged is completely covered by the ridges 4 spliced ​​together, avoiding the contact between the rigid inner wall of the silencer 3 and the airflow in this area. It can be understood that in this embodiment, the ridges 4 converge from the bottom of the inner wall of the silencer 3 toward the central axis of the silencer chamber 31 to a vertex, an edge or a top surface, so the width of the ridges 4 decreases from the bottom to the top. Even if the ridges 4 are spliced ​​together at the bottom to shield the inner wall of the silencer 3, sound absorbing grooves 41 can still be formed between adjacent ridges 4. Furthermore, in one embodiment, a flexible wall layer is provided on the inner wall of the silencer 3, and the raised portion 4 is provided on the wall layer. In this way, the shielding of the rigid inner wall of the silencer 3 is achieved by the wall layer. The specific arrangement of the raised portions 4 and whether the adjacent raised portions 4 are connected to each other through the bottom are irrelevant to the shielding of the inner wall of the silencer 3. The wall layer can preferably be complete and continuous to completely shield the inner wall of the silencer 3. At this time, the distance between the raised portions 4 can be selected only according to the size of the sound absorbing groove 41, and the raised portions 4 can be directly integrally formed on the wall layer.

[0044] The noise is reflected in the sound absorbing groove 41, and the flexible ridge 4 consumes the sound energy by buffering and absorbing vibration, but its total absorption efficiency is limited. Once the noise generated in the silencer cavity 31 exceeds its total absorption efficiency, it will cause the vibration of the silencer 3 and transmit the noise to the outside. Therefore, in one embodiment, a flexible sound absorbing layer is further provided on the outer periphery of the silencer 3 to absorb the vibration of the silencer 3 to absorb the noise, thereby further improving the noise reduction effect.

[0045] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A noise reduction hair dryer, comprising a housing and an air duct arranged in the housing, wherein a silencer is arranged at the air inlet end of the air duct, and a silencer cavity is arranged in the silencer for air flow to flow through, characterized in that: A plurality of flexible protrusions are arranged on the inner wall of the muffler, and sound absorbing grooves are formed between adjacent protrusions, so that the noise is blocked by the protrusions and reflected and consumed in the sound absorbing grooves.

2. A noise reduction hair dryer according to claim 1, characterized in that: The plurality of block-shaped protrusions are independently arranged and arranged in a mesh shape to form a plurality of sound absorbing grooves arranged in a mesh shape.

3. A noise reduction hair dryer according to claim 1, characterized in that: A plurality of strip-shaped protrusions are arranged side by side to form a plurality of strip-shaped sound absorbing grooves arranged side by side, or a plurality of strip-shaped protrusions are arranged alternately to form a plurality of discretely arranged sound absorbing grooves in a mesh shape.

4. The noise reduction hair dryer according to claim 1, characterized in that: The plurality of block-shaped protrusions are arranged in a plurality of rows, and in each row of protrusions, there are a plurality of groups of protrusions arranged along the airflow direction in the silencer chamber, and each group of protrusions includes at least two protrusions, so that the sound absorbing groove is formed between two adjacent groups of protrusions and / or between two adjacent protrusions in each group of protrusions.

5. A noise reduction hair dryer according to claim 4, characterized in that: Among the multiple groups of protrusions in each column of protrusions, at least two protrusions in each group of protrusions are arranged along the airflow direction in the silencer chamber, so that the front and rear sides of the sound absorbing groove along the airflow direction in the silencer chamber are blocked by the protrusions.

6. A noise reduction hair dryer according to claim 4, characterized in that: Among the multiple groups of protrusions in each column of protrusions, at least two protrusions in any group of protrusions are arranged along the airflow direction in the silencer chamber or along the circumference of the silencer chamber, and the protrusions in any two adjacent groups of protrusions are arranged in different ways, so that both sides of part of the sound absorbing grooves along the airflow direction in the silencer chamber and along both sides of the circumference of the silencer chamber are blocked by the protrusions.

7. A noise reduction hair dryer according to any one of claims 4 to 6, characterized in that: Any two adjacent rows of raised portions are arranged in an overlapping or staggered manner.

8. The noise reduction hair dryer according to claim 1, characterized in that: The width of the raised portion decreases from the inner wall of the muffler toward the central axis of the muffler cavity, so that the width of the sound absorbing groove increases from the inner wall of the muffler toward the central axis of the muffler cavity.

9. The noise reduction hair dryer according to claim 1, characterized in that: The raised portion converges from the bottom of the inner wall of the silencer toward the central axis of the silencer chamber to a vertex, an edge or a top surface, and the top surface is parallel to the flow direction of the airflow in the air duct to reduce the contact area between the airflow in the silencer chamber and the raised portion.

10. The noise reduction hair dryer according to claim 9, characterized in that: The raised portion is arranged at the bottom of the inner wall of the muffler and is rectangular, so that the outer periphery of the raised portion forms four side walls facing different directions.

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