HAIR DRYER CAPABLE OF INCREASING AIR FLOW RATE BASED ON NEGATIVE-PRESSURE FLOW INCREASING STRUCTURE

Abstract

A hair dryer capable of increasing an air flow rate based on a negative-pressure flow increasing structure is provided, which belongs to the technical field of hair dryers. The hair dryer includes an air duct part and a handle part docked to the air duct part. The air duct part has an annular cavity and a mixing cavity. A main air outlet is provided in a front end of the mixing cavity; a flow-increasing air inlet is provided in a rear end of the mixing cavity. A main air inlet is provided in a lower end of the handle part. An upper end of the handle part is communicated with the annular cavity, so that a longitudinal fluid flow passage from the main air inlet to the annular cavity is formed inside the handle part. A boosting unit is arranged inside the longitudinal fluid flow passage.

Claims

1. A hair dryer capable of increasing an air flow rate based on a negative-pressure flow increasing structure, comprising an air duct part (10) and a handle part (20) docked to the air duct part (10), wherein the air duct part (10) has an annular cavity (11), a mixing cavity (12), and a plurality of stages of annular rings (30); a main air outlet (13) is provided in a front end of the mixing cavity (12); a flow-increasing air inlet (14) is provided in a rear end of the mixing cavity (12); a main air inlet (21) is provided in a lower end of the handle part (20); an upper end of the handle part (20) is communicated with the annular cavity (11), so that a longitudinal fluid flow passage from the main air inlet (21) to the annular cavity (11) is formed inside the handle part (20); a boosting unit (22) is arranged inside the longitudinal fluid flow passage; a heating unit (15) is arranged at a middle section of the mixing cavity (12); the plurality of stages of annular rings (30) are arranged between the annular cavity (11) and the mixing cavity (12); two adjacent stages of annular rings (30) form a ring nozzle (31) communicated to the annular cavity (11) and the mixing cavity (12); the ring nozzle (31) faces the main air outlet (13); a curved bulge (32) inwards extending along the annular cavity (11) is formed on each annular ring (30) located in front of each ring nozzle (31), so that the ring nozzle (31) forms a curved transition structure from the annular cavity (11) to the mixing cavity (12); and the main air inlet (21), the longitudinal fluid flow passage, the boosting unit (22), the annular cavity (11), and the ring nozzles (31) form the negative-pressure flow increasing structure to generate, in the mixing cavity (12), the flow-increasing air flow that enters along the flow-increasing air inlet (14) and then exits through the main air outlet (13).

2. The hair dryer capable of increasing the air flow rate based on the negative-pressure flow increasing structure according to claim 1, wherein the annular cavity (11) has a flow guide cavity (111) with a tapered outer side and a transition cavity (112) docked to the flow guide cavity (111); the outer side of the flow guide cavity (111) forms an angle of 30 to 45 with a horizontal direction; an inner side of the flow guide cavity (111) is composed of the plurality of stages of annular rings (30); the plurality of stages of annular rings (30) are in a steplike shape from front to back and have inner diameters that gradually decrease; and the transition cavity (112) is communicated to an inside of the handle part (20).

3. The hair dryer capable of increasing the air flow rate based on the negative-pressure flow increasing structure according to claim 2, wherein the outer side of the flow guide cavity (111) and the last stage of annular ring (30) form a curved transition at a rear end and are set as the flow-increasing air inlet (14).

4. The hair dryer capable of increasing the air flow rate based on the negative-pressure flow increasing structure according to claim 1, wherein a spacing between two adjacent stages of annular rings (30) is 0.4 mm to 1 mm.

5. The hair dryer capable of increasing the air flow rate based on the negative-pressure flow increasing structure according to claim 2, wherein the transition cavity (112) is a horizontally arranged cavity structure; a cross-sectional area S.sub.12 of the transition cavity is set to be larger than a cross-sectional area S.sub.11 of the handle part (20); and a transverse length L12 of the transition cavity (112) is greater than 1.5 times to 2.5 times an inner diameter D11 of the handle part (20).

6. The hair dryer capable of increasing the air flow rate based on the negative-pressure flow increasing structure according to claim 5, wherein a cross-sectional area S.sub.21 of the flow-increasing air inlet (14) is set to be smaller than a cross-sectional area S.sub.24 of the main air outlet (13).

7. The hair dryer capable of increasing the air flow rate based on the negative-pressure flow increasing structure according to claim 1, wherein the heating unit (15) is arranged between the main air outlet (13) and the ring nozzles (31), and a distance is reserved between the heating unit (15) and the ring nozzles (31) to allow fluids entering the mixing cavity (12) from the ring nozzles (31) and the flow-increasing air outlet (14) to be fully mixed.

8. The hair dryer capable of increasing the air flow rate based on the negative-pressure flow increasing structure according to claim 1, wherein a connection point (33) is arranged between two adjacent stages of annular rings (30), and the two adjacent stages of annular rings (30) are connected through the connection point (33).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To describe the technical solutions in the embodiments of the present disclosure or in the related art more clearly, the following briefly introduces the accompanying drawings for describing the embodiments or the related art. Apparently, the accompanying drawings in the following description show merely some embodiments of the present disclosure, and a person of ordinary skill in the art may still derive other drawings from the accompanying drawings without creative efforts.

[0021] FIG. 1 is a schematic structural diagram of the present disclosure in a visual angle;

[0022] FIG. 2 is a schematic structural diagram of the present disclosure in another visual angle;

[0023] FIG. 3 is a schematic diagram of a cross-sectional structure according to the present disclosure;

[0024] FIG. 4 is a schematic structural diagram of part A in FIG. 3 according to the present disclosure;

[0025] FIG. 5 is a schematic structural diagram of part B in FIG. 3 according to the present disclosure;

[0026] FIG. 6 is a schematic diagram of a cross-sectional structure of an air duct part according to the present disclosure;

[0027] FIG. 7 is a diagram of an air flow generated only by rotation of a high-speed motor according to the present disclosure;

[0028] FIG. 8 is a diagram of an air flow generated according to a Bernoulli principle and a coanda effect according to the present disclosure; and

[0029] FIG. 9 is a diagram of an air flow during operation according to the present disclosure.

[0030] Reference numerals and names in the drawings are as follows: [0031] 10: air duct part; 11: annular cavity; 111: flow guide cavity; 112: transition cavity; 12: mixing cavity; 13: main air outlet; 14: flow-increasing air inlet; 15: heating unit; 20: handle part; 21: main air inlet; 22: boosting unit; 30: annular ring; 31: ring nozzle; 32: curved bulge; and 33: connection point.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions in the embodiments of the present disclosure are clearly and completely described below. Apparently, the described embodiments are merely some embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of present disclosure without making creative efforts shall fall within the protection scope of present disclosure.

[0033] Referring to FIG. 1 to FIG. 6, in this embodiment of the present disclosure, a hair dryer capable of increasing an air flow rate based on a negative-pressure flow increasing structure includes an air duct part 10 and a handle part 20 docked to the air duct part 10. The air duct part 10 has an annular cavity 11 and a mixing cavity 12. A main air outlet 13 is provided in a front end of the mixing cavity 12. A flow-increasing air inlet 14 is provided in a rear end of the mixing cavity 12. A main air inlet 21 is provided in a lower end of the handle part 20. An upper end of the handle part 20 is communicated with the annular cavity 11, so that a longitudinal fluid flow passage from the main air inlet 21 to the annular cavity 11 is formed inside the handle part 20. A boosting unit 22 is arranged inside the longitudinal fluid flow passage. A heating unit 15 is arranged at a middle section of the mixing cavity 12.

[0034] A plurality of stages of annular rings 30 are arranged between the annular cavity 11 and the mixing cavity 12. Two adjacent stages of annular rings 30 form a ring nozzle 31 facing the main air outlet 13. A curved bulge 32 inwards extending along the annular cavity 11 is formed on each annular ring 30 located in front of each ring nozzle 31, so that a last stage of ring nozzle 31 forms a curved transition structure from the annular cavity 11 to the mixing cavity 12.

[0035] The main air inlet 21, the longitudinal fluid flow passage, the boosting unit 22, the annular cavity 11, and the ring nozzles 31 form the negative-pressure flow increasing structure, so as to generate, in the mixing cavity 12, the flow-increasing air flow that enters along the flow-increasing air inlet 14 and then exits through the main air outlet 13.

[0036] After the hair dryer is turned on, the boosting unit 22 operates in the longitudinal fluid flow passage of the handle part 20, to drive air to enter the main air inlet 21 in the lower end of the handle part 20 and enter the annular cavity 11 along the longitudinal fluid flow passage. Between the annular cavity 11 and the mixing cavity 12, a special flow guide structure is formed by the plurality of stages of annular rings 30 and the curved bulges 32. The air is ejected at a high speed through the ring nozzles 31 between the adjacent annular rings 30, thus forming a high-speed transverse air flow. Due to high-speed ejection of the air, a negative-pressure region is formed inside the mixing cavity 12, thus forming a pressure difference with an external environment of the flow-increasing air inlet 14. This causes external air to quickly rush into the cavity from the flow-increasing air inlet 14 at the rear end of the mixing cavity 12 under the action of the pressure difference. The induced air flow is mixed with the air flow sprayed from the ring nozzles 31 in the mixing cavity 12, and then the mixed air flow is heated by the heating unit 15 located at the middle section of the mixing cavity 12 and is finally blown out from the main air outlet 13 at the front end of the mixing cavity 12, thus achieving efficient air blowing.

[0037] In the above technical solution, the negative-pressure flow increasing structure is designed by using a Bernoulli principle and a coanda effect. A high-speed motor is used as a power source for the hair dryer, namely the boosting unit 22. The air flow generated only by the rotation of the high-speed motor is shown in FIG. 7. The air flow induced by the negative-pressure flow increasing structure is shown in FIG. 8. Through the driving of the high-speed motor and the fluid flow passage design of this scheme, the air flow generated by the high-speed motor is mainly blown out against an inner wall. The high-speed air flow is sprayed out through the ring nozzles 31 and generates the negative pressure inside the mixing cavity 12. The external air is induced from the flow-increasing air inlet 14 through the negative pressure to form an air flow. The two air flows are mixed in the mixing cavity 12 and are finally blown out from the main air outlet 13. The mixed air flow is shown in FIG. 9.

[0038] The plurality of stages of annular rings 30 are formed between the annular cavity 11 and the mixing cavity 12. The ring nozzle 31 facing the main air outlet 13 is formed between two adjacent stages of annular rings 30. The curved bulge 32 inwards extending along the annular cavity 11 is formed on each annular ring 30 located in front of each ring nozzle 31, so that the last stage of ring nozzle 31 forms the curved transition structure from the annular cavity 11 to the mixing cavity 12. A coanda effect is ingeniously used, and the negative-pressure flow increasing structure is optimized, so that a fluid can flow from the annular cavity 11 to the mixing cavity 12 more smoothly. Then, the negative pressure generated by the high-speed air flow formed based on the ring nozzles can better drive the surrounding air to enter the flow-increasing air inlet to form the flow-increasing air flow which moves forwards. This improves overall performance of the hair dryer, greatly improves a user experience, and significantly increases a flow rate of air entering the hair dryer. Compared with a traditional hair dryer, the hair dryer can greatly shorten hair drying time and save energy for a user.

[0039] In addition, the heating unit 15 heats all air that enters the mixing cavity 12, thereby ensuring that the extra induced air can also reach an appropriate temperature, avoiding a decrease in an air temperature due to an increase in an air volume, ensuring the effect of hair drying, and improving a comfort level of a user during use and hairdressing efficiency, so that the hair dryer achieves breakthrough in performance and practicability.

[0040] Referring to FIG. 3 to FIG. 5, the annular cavity 11 has a flow guide cavity 111 with a tapered outer side and a transition cavity 112 docked to the flow guide cavity 111. The outer side of the flow guide cavity 111 forms an angle of 30 to 45 with a horizontal direction. An inner side of the flow guide cavity 111 is composed of the plurality of stages of annular rings 30. The plurality of stages of annular rings 30 are in a steplike shape from front to back and have inner diameters that gradually decrease. The transition cavity 112 is communicated to an inside of the handle part 20. The air flow can be effectively guided to be accelerated, so that more air can be induced from the flow-increasing air inlet 14. The outer side and inner side of the flow guide cavity 111 form curved transition at a rear end and are set as the flow-increasing air inlet 14. This reduces resistance of flowing of the air flow and reduces energy loss. A spacing between two adjacent stages of annular rings 30 is 0.4 mm to 1 mm, so that this ensures that the air flow is sprayed out at a high speed to generate a negative pressure. The transition cavity 112 is a horizontally arranged cavity structure. In order to avoid an increase in air resistance, a cross-sectional area S12 of the transition cavity is set to be larger than a cross-sectional area S.sub.11 of the handle part 20, and transverse length L12 of the transition cavity 112 is greater than 1.5 times to 2.5 times an inner diameter D11 of the handle part 20. This effectively avoids the increase in the air resistance and ensures that the air smoothly flows into the annular cavity 11. A cross-sectional area S21 of the flow-increasing air inlet 14 is set to be smaller than a cross-sectional area S24 of the main air outlet 13, thus avoiding the increase in the resistance, pushing the air flow to quickly move forwards, and achieving efficient air blowing.

[0041] During use of the hair dryer, the boosting unit 22 starts to work, driving the air to enter the handle part 20 from the main air inlet 21 to form an air flow. Later, the air flow enters the transition cavity 112 from the handle part 20. In order to avoid the increase in the air resistance, the cross-sectional area S.sub.12 of the transition cavity 112 should be larger than the cross-sectional area S.sub.11 of the handle part 20, but should not be larger than {circle around (2)} times of the cross-sectional area of the handle part 20, namely, S.sub.12 cos 45. S.sub.11. The air flow enters the flow guide cavity 111 through the transition cavity 112, and is blown into the mixing cavity 12 from the ring nozzles 31. The negative-pressure flow increasing structure is a core component of the hair dryer. The negative-pressure flow increasing structure is provided with the flow guide cavity 111, the plurality of stages of annular rings 30, and the ring nozzles 31. The flow guide cavity 111 is a tapered cavity and is obtained according to a continuous equation and a bernoulli equation. The purpose is that after the air flow enters the product, the cross-sectional area gradually decreases, so that the speed of the air may gradually increase, and the pressure may gradually decrease. The continuous equation is .sub.1S.sub.1V.sub.1=.sub.2S.sub.2V.sub.2, and the bernoulli equation is

[00001]$p_1+\frac{1}{2}{V}_1^2=p_2+\frac{1}{2}{V}_2^2.$

According to the principle of aerodynamics, a pressure variable is relatively small, and correspondingly, .sub.11.sub.2. In this case, is an air density at a normal temperature and a normal pressure. Therefore, [0042] the continuous equation is simplified into: S.sub.1V.sub.1=S.sub.2V.sub.2; and [0043] the bernoulli equation is simplified into:

[00002]$p_1+\frac{1}{2}{V}_1^2=p_2+\frac{1}{2}{V}_2^2.$

[0044] When the area S decreases, V may increase according to the continuous equation; and the pressure intensity p may decrease according to the bernoulli equation.

[0045] Therefore, after being accelerated by the negative-pressure flow increasing structure, the high-speed air flow is formed and is then ejected from the ring nozzles 31. In this case, the speed is maximum, and the negative pressure can be generated in the mixing cavity 12 that is connected subsequently. When entering the ring nozzles 31 from the flow guide cavity 111, the air flow can pass through the curved bulges 32. According to the coanda effect, when the air flow passes through a curved surface, the air flow can flow against the curved surface due to viscidity of air, thus avoiding flowing separation when the air flow enters the ring nozzles 31 from the flow guide cavity 111 and reducing energy loss.

[0046] As mentioned above, after being ejected from the ring nozzles 31, the high-speed air flow can generate the negative pressure in the mixing cavity 12, and an atmospheric environment, namely a pressure intensity, in which the flow-increasing air inlet 14 is located is 1 atm, and a relative pressure intensity displayed on a pressure gauge is 0 Pa. Therefore, a pressure difference may be formed between the mixing cavity 12 and the flow-increasing air inlet 14. It can be learned according to the bernoulli equation that,

[00003]$p_{22}+\frac{1}{2}{V}_{22}^2=p_{21}+\frac{1}{2}{V}_{21}^2+$ [0047] where is energy loss caused by a viscosity force; p.sub.21=0 Pa, and an increased flow rate can be estimated through a computational fluid dynamics (CFD) technology according to data of the boosting unit and the like.

[0048] Finally, the air flow driven by the boosting unit 22 and the air flow induced by the negative-pressure flow increasing structure are mixed together in the mixing cavity 12 and then enter the heating unit 15. The heating unit 15 heats the air flow to a temperature, and the air flow is blown out from the air outlet to hairs.

[0049] Referring to FIG. 3 and FIG. 6, the heating unit 15 is arranged between the main air outlet 13 and the flow-increasing air inlet 14, so that the air can be heated immediately after entering the mixing cavity 12, which reduces loss of heat during transferring and ensures that the temperature of the blown air is stable and efficient. A connection point 33 are arranged between two adjacent stages of annular rings 30, and the two adjacent stages of annular rings 30 are connected through the connection point 33. This improves overall structural stability of the annular cavity 11 and avoids looseness or deformation of the annular rings 30 caused by vibration generated by high-speed flowing of the air flow, thus ensuring that the air flow can be stably and smoothly sprayed out from the main air outlet to continuously generate a negative pressure, increasing an air inducing amount, and improving air blowing efficiency. This connection mode further lowers manufacturing and assembling difficulties, facilitates later-stage maintenance and repair, and further improves comprehensive advantages of the hair dryer in performance guarantee and use convenience.

[0050] For those skilled in the art, it is apparent that the present disclosure is not limited to the details of the exemplary embodiments mentioned above, and can be implemented in other specific forms without departing from the spirit or basic features of the present disclosure. Therefore, in any perspective, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present disclosure is limited by the accompanying claims rather than the above description. Therefore, all changes within the meaning and scope of the equivalent conditions of the claims within the present disclosure.