CN107847031B

CN107847031B - Hair dryer comprising an air outlet duct with coanda effect

Info

Publication number: CN107847031B
Application number: CN201680043901.6A
Authority: CN
Inventors: 沃兰迪·吉威勒; 尼古拉斯·洛谢
Original assignee: SEB SA
Current assignee: SEB SA
Priority date: 2015-07-28
Filing date: 2016-07-08
Publication date: 2020-11-20
Anticipated expiration: 2036-07-08
Also published as: RU2712366C1; BR112018001555A2; KR102585672B1; EP3328237A1; CN107847031A; EP3328237B1; FR3039377A1; WO2017017330A1; FR3039377B1; KR20180034531A; ES2837131T3; BR112018001555B1

Abstract

The invention relates to a hair dryer (1) intended to provide significant drying and sensoring properties, while reducing noise. The hair dryer comprises an air circulation chamber (3) equipped with an inlet region (4) and an outlet region (5), an air circulation system (6) and a heating element (10). The blower also comprises a duct (11) arranged in the extension of the circulation chamber. The conduit has an upstream end (12), a downstream end (13) and a neck (14) arranged between said ends, a first portion of the conduit arranged between the upstream end and the neck having a descent angle (a) with respect to a longitudinal axis (X), the descent angle being comprised between 40 ° and 88 °, a second portion of the conduit arranged between the neck and the downstream end having an opening angle (β) with respect to the longitudinal axis, the opening angle being comprised between 1.5 ° and 3.5 °.

Description

Hair dryer comprising an air outlet duct with coanda effect

Technical Field

The present invention relates to the field of hair dryers and aims to provide significant drying and feel performance while reducing the noise of the device.

Background

Traditionally, hair dryers include an air intake zone, an air circulation chamber, an air output zone, an air circulation system and a heating element. The air circulation system and the heating element are integrated in the circulation chamber. The air circulation system draws in outside air through the intake zone and then conveys it in the circulation chamber from upstream towards downstream, and this air passes through the heating element, the more or less heated air then being blown to the outside through the output zone, in order to dry the hair.

The known patent application US2013/0111777a1 describes a blower configured for increasing the air flow rate at the outlet. To this end, the hair dryer comprises an output head configured for generating a coanda effect resulting in an acceleration of the air flow and for increasing the air flow. According to this design, the flow of air at the outlet is perpendicular to the flow of air in the circulation chamber, which forces high power of the circulation system and high speed operation of the motor equipped in the circulation system, so that the coanda effect is effective. This design therefore causes a large energy consumption and sound hazard, which is a frequently encountered problem in the prior art blowers, regardless of their design.

Disclosure of Invention

The present invention overcomes these disadvantages of the prior art hair dryers and in particular aims to optimise the achievement of the coanda effect in the air output region.

To this end, the invention relates to a hair dryer comprising an air circulation chamber provided with an inlet zone and an outlet zone. The blower also includes an air circulation system and a heating element disposed in the circulation chamber. The air circulation system is configured to suck in outside air through the inlet area, then to convey this air in the circulation chamber from upstream to downstream while passing the heating element, and finally to blow more or less heated air to the outside through the outlet area. Such blowers are known to comprise a temperature regulation mechanism of the heating element for modifying the temperature of the air blown to the outlet and a speed regulation mechanism of the air circulation in the circulation chamber, acting in particular on the rotation speed of the motor driving the propeller.

Notably, the blower comprises a duct arranged in the prolongation of the circulation chamber and at the outlet area. Thus, the circulation chamber and the conduit are arranged along the same longitudinal axis. Further, the conduit has an upstream end, a downstream end, and a neck disposed between the upstream end and the downstream end. More precisely, the neck corresponds to the inner contour of the conduit with the smallest cross section. A first portion of the conduit arranged between the upstream end and the neck has a descent angle with respect to a longitudinal axis of the circulation chamber, the descent angle being between 40 ° and 88 °. The first portion thus has a continuous reduction of the cross section of the duct from the upstream end to the neck. The descent angle corresponds to a maximum angle adopted by the first portion of the conduit with respect to the longitudinal axis. A second portion of the conduit disposed between the neck and the downstream end has an opening angle relative to the longitudinal axis that is between 1.5 ° and 3.5 °. The second portion thus has a continuous enlargement of the cross section of the duct from the neck to the downstream end. The cross-section of the catheter produces a coanda effect at the neck from the reduced portion to the enlarged portion. The neck connecting the first and second portions of the conduit has a curved shape, preferably a circular shape, configured to facilitate the creation of the coanda effect.

The coanda effect produced at the neck causes an acceleration of the air at the outlet of the duct. Furthermore, the opening angle allows to increase the section of the duct in the second portion between the downstream end and the neck, which results in an increase of the air flow at the duct outlet. The applicant has noticed that by implementing the above-mentioned geometrical parameters of the duct, i.e. by selecting the descent angle and the opening angle within the above-mentioned range of values, the duct allows to produce in an optimal way an acceleration of the air at the outlet and an increase of the air flow. The power and size of the air circulation system, whose electric mechanism can operate at a lower rotation speed than that of the prior art hair dryer, can thus be reduced, while equally even improving the drying and feel properties of the hair. This advantageously allows for improved sound performance of the hair dryer.

In a preferred embodiment of a hair dryer according to the invention, said angle of descent is 82 °. Likewise, the opening angle is 2.5 °. The selection of one and/or the other of the above parameters allows to optimize the result.

In a preferred embodiment of a hair dryer according to the present invention, said duct has a circular cross-section. However, a duct having a cross-section that is rectangular or triangular or even other shapes is contemplated without departing from the scope of the present invention.

According to this preferred embodiment of the hair dryer, said duct has a circular cross section, said neck having a reduction in diameter of between 2mm and 4mm with respect to said downstream end portion. Preferably, the diameter reduction is 2 mm.

In an embodiment of a hair dryer according to the invention, the heating element is spaced from the neck of the duct by a distance of between 0mm and 5 mm. The coanda effect is greatly reduced when the heating element is located in the converging region of the neck of the conduit corresponding to zero distance. In contrast, when the distance exceeds 5mm, no difference in the coanda effect is noticed. In a preferred embodiment, the distance is 4mm, which allows optimization of the coanda effect.

In an embodiment of a hair dryer according to the invention, a grille is arranged between said heating element and said duct. The purpose of the presence of such a grid is to prevent any direct contact of the heating element with the finger when inserted through the duct.

In an embodiment of a hair dryer according to the invention, a detachable connection is arranged between said circulation chamber and said duct so as to allow removal of said duct, for example for replacing a duct of circular cross section by another, similar of different size or by another duct of rectangular or triangular cross section.

Drawings

The following description of the preferred embodiments with reference to the accompanying drawings allows to highlight the object of the invention, in which:

figure 1 shows a sectional view of a hair dryer according to the invention;

figure 2 shows an enlarged cross-sectional view of the rear part of the blower of figure 1;

figure 3 shows a cross-section of an individual catheter.

Detailed Description

As shown in fig. 1, the hair dryer comprises a main body 2 having a substantially cylindrical shape allowing to constitute a circulation chamber 3 having a longitudinal axis X. The circulation chamber 3 comprises an inlet region 4 and an outlet region 5. A circulation system 6 is arranged in this circulation chamber 3, which circulation system allows ambient air to be sucked in through the inlet area and then delivered over the entire length of the circulation chamber 3 in order to subsequently blow the air outside the blower 1 through the outlet area 5. The circulation system 6 comprises a propeller 7 arranged in the vicinity of the inlet area 4, an electric motor 8 which allows to drive the propeller 7 in rotation, and a rectifier 9 which is arranged downstream of the propeller 7 and allows to channel the air at the outlet of the propeller 7. The hair dryer 1 also comprises a heating element 10, arranged downstream of the rectifier 9, which allows heating of the air in the downstream portion of the circulation chamber 3, which is then expelled through the outlet region 5. The hair dryer 1 also comprises a control and regulation mechanism (not shown) of the motor 8 and of the heating element 10, which allows modifying the rotation speed of the motor 8 and the temperature of the heating element 10, respectively, from a rest position to a full-power position. All of these features are typically present on a hair dryer and, therefore, are not described in detail in the ensuing description.

The invention relates in particular to a catheter 11 as shown in figures 1 to 3. This duct 11 is arranged along the longitudinal axis X in the prolongation of the outlet region 5 of said circulation chamber 3, as shown in figures 1 and 2. The conduit 11 preferably has a circular shape and comprises an upstream end portion 12 and a downstream end portion 13. The upstream end 12 of the duct 11 has a cross section corresponding to the cross section of the outlet zone 5 of the circulation chamber 3. Furthermore, the duct 11 has a rotary shape and a neck 14 defining an upstream portion 15 and a downstream portion 16 on the duct 11, as shown in fig. 3. The configuration of the duct 11 as shown in figures 1 to 3 allows to make the air output from the circulation chamber 3 with a coanda effect, a phenomenon known as hydromechanics. The air output from the circulation chamber 3 at the outlet region 5 undergoes a reduction in the passage section, due to the presence of the neck 14, which restricts the air flow along an angle corresponding to the descent angle α of the upstream portion 15, as shown in fig. 3. The outgoing air is thus compressed up to the passage section of the neck 14. Once through the neck, this outgoing air expands with increasing passage section up to the downstream end 13 of the duct 11. Thus, the outgoing air expands and flows along an angle corresponding to the opening angle β of the downstream portion 16, as shown in fig. 3. The fall angle a and the opening angle β are defined relative to the longitudinal axis in fig. 3. This geometry of the duct 11 allows to produce an intake of the outgoing air towards the downstream end 13, which increases the air velocity at the outlet. Furthermore, this geometry of the ducts 11 allows to increase jointly the air flow at the outlet.

Studies by the applicant have shown the importance of selecting the descent angle a of the upstream portion 15 and the opening angle β of the downstream portion 16, which are adjusted so as to increase the air speed and flow rate at the outlet of the duct 11. The applicant has noticed that a descent angle α comprised between 40 ° and 88 °, preferably 82 °, and an opening angle β comprised between 1.5 ° and 3.5 °, preferably equal to 2.5 °, allow to optimize this increase in the speed and flow rate of the air at the outlet of the duct 11.

The dimensions of the duct 11 are variable and are partially adapted to the dimensions of the circulation chamber 3, the passage section of the upstream end 12 of the duct 11 corresponding to the passage section of the outlet region 5 of said circulation chamber 3, and the angle of descent α and the angle of opening β of the duct 11 being chosen within the range of the above-mentioned values. The applicant has noted that the air velocity at the outlet can be further improved while maintaining an excellent flow rate by reducing the diameter D1 at the neck 14 with respect to the diameter D2 at the downstream end 13, which is reduced by between 2 and 4mm, preferably 2 mm. Preferably, the diameter D2 at the downstream end 13 of the duct is chosen between 30mm and 40mm, preferably equal to 32mm, which also helps to blow the air at the outlet at an optimal speed, while maintaining an excellent flow rate.

As shown in fig. 2, the downstream end 17 of the heating element 10 is spaced from the neck 14 of the conduit 11 by a distance d of between 0mm and 5mm, which affects the coanda effect. Preferably, the distance d is 4mm in order to optimize the coanda effect.

As shown in fig. 1 and 2, the hair dryer 1 comprises a grille 18 arranged downstream of the heating element 10 in the circulation chamber 3. The grid 18 avoids any contact with the heating element 10.

Other features or variations may be considered without departing from the scope of the invention.

In fig. 1 to 3, the duct 11 is circular in shape. However, for the duct 11, a square, rectangular or triangular section may be considered, even other sections may be considered, while maintaining the descent angle α and the opening angle β provided for the embodiment such as that of fig. 1 to 3.

In fig. 1 to 3, the conduit 11 is permanently fixed to the circulation chamber 3. However, a removable connection means may be provided between the downstream end 19 of the circulation chamber 3 and the upstream end 12 of the conduit 11, for example a nesting or snap-fit system between the downstream end 19 and the upstream end 12, so as to allow the removal of the conduit 11 in order to replace it by another different configuration within the scope of the invention.

Claims

1. Hair dryer (1) comprising an air circulation chamber (3) equipped with an inlet area (4) and an outlet area (5), an air circulation system (6) and a heating element (10) configured in the circulation chamber so as to suck in external air through the inlet area and convey it in the circulation chamber from upstream towards downstream while passing the heating element and blowing more or less heated air to the outside through the outlet area, characterized in that it comprises a duct (11) arranged in the extension of the circulation chamber at the outlet area, said duct having an upstream end (12), a downstream end (13) and a neck (14) arranged between the upstream and downstream ends, a first portion (15) of the duct arranged between the upstream end and the neck has a descent angle (a) with respect to a longitudinal axis (X) of the circulation chamber, the descent angle being comprised between 40 ° and 88 °, a second portion (16) of the duct arranged between the neck and the downstream end has an opening angle (β) with respect to the longitudinal axis, the opening angle being comprised between 1.5 ° and 3.5 °, and the neck (14) connecting the first portion (15) and the second portion (16) of the duct (11) has a curved shape configured to favour the production of the coanda effect.

2. Hair dryer (1) according to claim 1, characterized in that said neck (14) connecting said first portion (15) and said second portion (16) of said duct (11) has a circular shape.

3. Hair dryer (1) according to claim 1, characterized in that said angle of descent (α) is 82 °.

4. Hair dryer (1) according to any of claims 1 to 3, characterized in that said opening angle (β) is 2.5 °.

5. Hair dryer (1) according to any of claims 1 to 3, characterized in that said duct (11) has a circular cross section.

6. Hair dryer (1) according to claim 5, characterized in that said neck (14) has a diameter reduction comprised between 2mm and 4mm with respect to said downstream end.

7. Hair dryer (1) according to claim 6, characterized in that said reduction in diameter is 2 mm.

8. Hair dryer (1) according to any of claims 1 to 3, characterized in that said duct (11) has a rectangular cross section.

9. Hair dryer (1) according to any of claims 1 to 3, characterized in that said duct (11) has a triangular cross section.

10. Hair dryer (1) according to any of claims 1 to 3, characterized in that said heating element (10) is spaced from the neck (14) of said duct (11) by a distance (d) comprised between 0mm and 5 mm.

11. Hair dryer (1) according to claim 10, characterized in that said distance (d) is 4 mm.

12. Hair dryer (1) according to any of claims 1 to 3, characterized in that a grille (18) is arranged between said heating element (10) and said duct (11).

13. Hair dryer (1) according to any of claims 1 to 3, characterized in that a detachable connection is arranged between said circulation chamber (3) and said duct (11) so as to allow the removal of said duct.