TWI457103B - Hand dryer - Google Patents

Description

Hand dryer

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a hand drying apparatus for drying a hand wetted by washing by a jet of a high-speed air stream.

In the past, a hand drying device for drying a sanitary hand has been developed, and the wetted hand can be dried by spraying a high-speed air stream without blowing a towel or a handkerchief. As such a hand drying device, there has been disclosed an invention in which two air nozzle portions for ejecting a high-speed air flow are provided in the opposite direction near and at the entrance of the hand drying chamber, so that both the back of the hand and the palm of the hand are simultaneously In the face wind, moisture is blown off from the hand and dried (see Patent Document 1).

Another invention has been disclosed in which a hand insertion opening for juxtaposed insertion of right and left hands, a first wall portion facing the nails of the left and right hands inserted side by side from the hand insertion opening, and a palm facing the first and right hand portions and the first wall portion The second wall portion extends approximately parallel to the direction of the fingers of the left and right hands inserted in parallel and extends across the entire length of the hand, and is disposed in the center of each of the first wall portion and the second wall portion, and has a hand drying chamber Further, the hand drying chamber is provided with a pair of nozzle portions for ejecting a high-speed air flow to the left and right, respectively, so that the back of the left and right hands and the palm are approximately parallel (see Patent Document 2).

[Patent Document 1] JP-A-2003-180554 (pages 2 and 3, pictures 1 and 9)

[Patent Document 2] JP-A-2005-087283 (page 6, page 1 to figure 5)

However, the hand dryer disclosed in Patent Document 1 has a problem in that a high-speed air stream ejected from two air nozzle portions facing each other collides, causing a turbulent flow of the air stream to generate noise.

Moreover, the hand drying apparatus disclosed in the above-mentioned Patent Document 2 has a problem in that the pair of air nozzle portions are configured such that the back of the right and left hands and the palm of the hand are approximately parallel to each other, and the high-speed air flow is ejected from the right and left sides, respectively. Moisture is difficult to remove, especially when the air flow does not pass between the finger and the finger, and the moisture attached between the finger and the finger is hardly removed.

The present invention has been made in view of the above problems, and an object thereof is to provide a hand drying device which is low in noise and which can remove moisture adhering between a finger and a finger.

In order to solve the above problems and achieve the object, the present invention features a hand drying chamber having a hand insertion opening that can be inserted in parallel with the right and left hands, a first wall portion facing the back of the hand inserted from the hand insertion opening, and the palm and the above a second wall portion facing the first wall portion, a pair of sides on the side of the first wall portion and the side of the second wall portion are approximately parallel to the direction of the finger of the inserted hand, and are approximately the same An air nozzle portion that extends over the entire length and that ejects a high-speed air flow toward the back of the hand or the palm of the hand.

The hand drying device of the present invention can achieve the effect of less noise and can remove moisture attached between the finger and the finger.

Hereinafter, the embodiment of the hand drying device of the present invention will be described in detail based on the drawings. Moreover, this embodiment does not limit the invention.

The first embodiment type.

Fig. 1 is a side elevational view showing a first embodiment of the hand dryer according to the present invention, and Fig. 2 is a front elevational view showing the hand dryer of the first embodiment. As shown in Figs. 1 and 2, the hand drying device 81 of the first embodiment forms a hand drying chamber 2 on the upper portion of the main body casing 1. The hand dryer 81 is used by fixing the main body casing 1 to a wall surface of a washstand or the like using a screw or the like.

On the front side (the side of the user) of the upper portion of the main body casing 1, a second wall portion 3 is formed, and on the upper rear side, a first wall portion 4 is formed. The hand drying chamber 2 is surrounded by the inner surface 5 of the second wall portion 3, the inner surface 6 of the first wall portion 4, and the bottom surface 8 of the water droplets blown away from the hand. In the upper portion of the hand drying chamber 2, a hand insertion opening 9 for allowing the hand to enter and exit is formed, and on both sides thereof, a side opening portion 10 for allowing the air after the hand drying process to flow out is formed.

At a lower portion of the main body casing 1, a high-pressure airflow generating device 11 is provided, and the high-pressure airflow generated by the high-pressure airflow generating device 11 passes through the air supply duct 12 formed in the first wall portion 4, and then introduced into the first wall portion. 4 air nozzle portion 13.

The user's hand inserted into the hand drying chamber 2 is inserted into the hand drying chamber 2 with the wrist on the front side and the fingertip on the rear side in a state where the user standing on the front side of the main body casing 1 is naturally horizontally juxtaposed with the left and right hands.

The air nozzle portion 13 is provided to protrude from the inner surface 6 of the first wall portion 4 at a position facing the left and right hands of the hand drying chamber 2. Further, the longitudinal direction of the air nozzle portion 13 extends approximately parallel to the respective finger directions of the hand inserted in the up and down direction, and the upper portion is formed on the front side and the lower portion is on the rear side at an angle of inclination of 5 to 45 degrees. The above-mentioned finger direction refers to the direction of the approximate middle finger of the naturally expanding hand. Further, the inner surface 5 of the second wall portion 3 is such that the hand is easily inserted into the hand drying chamber 2 and the distance from the air nozzle portion 13 is approximately fixed, and the front inclination angle is formed.

The hand dryer 81 blows the high-speed air stream 14 (wind speed: 50 m/s to 250 m/s) from the air nozzle unit 13 into the hand drying chamber 2, and blows the moisture attached to the left and right hands of the hand drying chamber 2 to the first The inner surface 5 of the second wall portion 3, the blown water droplets are collected on the inner surface 5 and the bottom surface 8 of the second wall portion 3, and the collected water droplets are slid to the drain groove 17 through the drain port 15 and the drain pipe 16. The drain groove 17 is slidable back and forth with respect to the body casing 1, and is detachably attachable to cover the detachable cover.

The high-pressure air flow generating device 11 is provided with a DC brushless motor (which may be a general commutator motor or an induction motor), a motor drive circuit, and a turbo fan driven by a DC brushless motor, and is automatically operated by the control circuit 18. The suction hole 19 of the high-pressure air flow generating device 11 faces the intake passage 20 provided in the main body casing 1, and the outside air is taken in from the suction port 21 at the lower end of the intake passage 20. The air taken in from the suction port 21 is removed by dust, moisture, and the like by the filter 25, and supplied to the high-pressure airflow generating device 11.

On the inner surface 6 of the first wall portion 4, a hand detecting sensor 22 is provided, and by detecting the detection signal of the sensor 22 by hand, it is detected whether or not the hand is inserted into the hand drying chamber 2 from the hand insertion opening 9. The detection signal of the hand detection sensor 22 is input to the control circuit 18 having a microcomputer. When the control circuit 18 judges that the hand has been inserted, the high-pressure airflow generating device 11 is energized, and the high-speed airflow 14 is ejected from the air nozzle portion 13.

When the right and left hands are naturally inserted from the hand insertion opening 9 of the hand drying device 81 into the hand drying chamber 2 to the extent of approaching the wrist, the hand detection sensor 22 detects the insertion of the hand, and is controlled by the control circuit 18. The high-pressure airflow generating device 11 is actuated, and the high-speed airflow is ejected obliquely downward from the air nozzle portion 13 toward the front side of the hand drying chamber 2.

Fig. 3 is a side view showing the state in which the hand drying device of the first embodiment is inserted and smashed, and Fig. 4 is a vertical sectional view showing the air nozzle portion of the hand drying device of the first embodiment and inserted. The relative position of the hand. As shown in FIGS. 3 and 4, when the wrist and the fingertip are used to whip the palm and the back of the hand, the high-speed air flow 14 ejected from the air nozzle portion 13 is not only opposed to the entire hand but also between the fingers and the fingers. Blow off the moisture on your hands.

Fig. 5 is a horizontal sectional view taken along line A-A of Fig. 1. As shown in Fig. 5, the high-speed air flow 14 that blows the water droplets between the fingers and the fingers is directed against the inner surface 5 of the second wall portion 3 to change the flow direction, and flows out from the side opening portion 10 to the outside. . At this time, the blown water droplets are separated from the air flow by the inertial force due to the flow direction of the high-speed air flow 14, and are transmitted to the inner surface 5 and the bottom surface 8 of the second wall portion 3 from the drain port 15 (see the second The recovery is stored in the drain tank 17 through the drain pipe 16.

The second wall portion 3 shields the high velocity air stream 14 in front of the user so that the high velocity air stream 14 and water droplets do not splash onto the user. When the hand is removed from the hand drying chamber 2 after the drying process of the hand is completed, the hand detecting sensor 22 detects this point, and the high-pressure air flow generating device 11 is stopped.

Next, the air nozzle portion 13 will be described in detail. When the hand drying device 81 is used, the user who stands in front of the front side of the main body casing 1 naturally has the hands horizontally juxtaposed, the wrist is located on the front side, the fingertip is located on the rear side, and the hand drying chamber 2 is obliquely inserted.

The air nozzle portion 13 is disposed to extend forward in the first wall portion 4 facing the both hands of the hand drying chamber 2 so as to extend in the vertical direction, and the upper portion is located on the front side and the lower portion is located on the rear side. By the arrangement of the above-described air nozzle portion 13, the high-speed air flow 14 discharged from the air nozzle portion 13 is in an air curtain state extending in the vertical direction, and is a fluid that advances obliquely downward from the rear side of the hand drying chamber 2 toward the proximal end.

The high-speed air flow 14 directly faces the wrist of each hand to the entire hand of the fingertip and enters between the finger and the finger. Therefore, if the part from the wrist to the fingertip is smashed and placed against the palm of the hand and the back of the hand, The water between the palm, the back of the hand and the finger is blown away, so that the hands can be dried even if the hand is not moved in the up and down direction.

Further, as shown in FIG. 3, since the air nozzle portion 13 is disposed at a position facing the right and left hands of the hand drying chamber 2, the distance between the hand and the air nozzle portion 13 can be shortened. Further, the upper portion is located on the front side and the lower portion is located on the rear side, and is disposed at a front tilt angle. Therefore, the distance between the hand and the air nozzle portion 13 is approximately fixed from the wrist to the fingertip. Thus, the high velocity air stream 14 maintains considerable kinetic energy without attenuating the flow rate and is directed at the same speed against the entire hand, effectively and uniformly removing moisture.

Since the air ejection port 24 of the air nozzle portion 13 faces downward, it is possible to prevent water droplets in the hand drying chamber 2 from intruding into the body casing 1 from the air ejection port 24. Further, the air nozzle portion 13 is provided only on the side of the first wall portion 4, and the air nozzle is not provided in the second wall portion 3. Therefore, the high-speed air flow 14 to be ejected does not collide, and the collision of the high-speed air flow is caused. The noise does not occur, so the noise of the hand dryer 81 is small.

Further, the high-speed air flow 14 is sprayed obliquely downward and blows water droplets in the direction of gravity, so that the moisture on the hand can be efficiently removed. Further, the airflow after the drying of the hand is also obliquely downward, as shown in Fig. 3, flowing from the hand drying chamber 2 to the lower side of the side opening portion 10 without flowing out from the hand insertion opening 9, so that it is difficult for the user. It is sprayed by wind, water droplets, etc.

Further, when the user standing in front of the front side of the main body casing 1 naturally inserts both hands into the hand drying chamber 2 in a horizontal juxtaposition, the left and right hands are spaced approximately in parallel, or, as shown in Fig. 4, the left and right hands are spaced apart at the wrist. The side is larger and smaller on the side of the fingertip. Therefore, the interval between the pair of air nozzle portions 13 in the horizontal direction is larger on the side where the hand is inserted, and the side on the deep side is smaller, and the angle sandwiched by the pair of air nozzle portions 13 is set to 0 to 60 degrees ( For adults, it can be set to a V shape of about 20 degrees). Thereby, the angle between the right and left hands is aligned with the angle between the pair of air nozzle portions 13, and the high-speed air flow 14 is opposed to the entire hand and the finger and the finger, and the moisture removal ability is improved.

In a conventional hand drying device that ejects a high-speed air stream from an air nozzle in one of the opposite configurations, the high-speed air flow simultaneously faces the back of the hand and the palm of the hand, so that in the space between the fingers and fingers where the respective air flows are not obscured by the hand. The air flow colliding with each other causes the wind speed to drop, and there is a problem that the moisture on the side of the finger cannot be sufficiently removed.

In the hand drying device 81 of the first embodiment, since the pair of air nozzle portions 13 are not disposed to face each other, the high-speed air flow can be directly opposed to the state in which the wind speed is maintained regardless of the position of the hand. Further, since the air nozzle portion 13 extends in the vertical direction, the high-speed air flow 14 that is ejected can enter the gap between the finger and the finger as shown in Fig. 5, and the moisture on the side of the finger can be efficiently removed.

Next, the air ejection port of the air nozzle portion 13 will be described in detail. Fig. 6 is a view showing an air ejection port of the hand drying device of the first embodiment, Fig. 7 is a view showing a modification of the air ejection port, and Fig. 8 is a view showing another modification of the air ejection port. Fig. 9 is a view showing still another modification of the air ejection port, and Fig. 10 is a side view showing a modification of the air nozzle portion.

As shown in Fig. 6, the air nozzle portion 13 of the hand dryer of the first embodiment is arranged such that the air ejection ports 24 of the long holes are arranged in a dotted line, and the drying performance and the noise performance are excellent. As shown in Fig. 7, the air ejection port may be a slit-shaped air ejection port 24a. As shown in Fig. 8, the air ejection port 24b of the circular hole may be continuously arranged in a dotted line. Further, as shown in Fig. 9, the air ejection ports 24 of the long holes may be arranged in a line in a dotted line, and a plurality of them may be continuously arranged. Further, the air nozzle portion 13 does not have to be integrally formed. As shown in Fig. 10, a plurality of air nozzle portions 13a can be arranged in a line in a dotted line and arranged continuously.

The length of the arrangement of the air ejection ports 24, 24a, 24b is set to be longer than the length of the fingertip of the wrist to the middle finger (150 mm or more in the first embodiment), and the high-speed air flow simultaneously faces the entire hand, efficiently Remove moisture.

Further, as shown in Fig. 5, the air nozzle portion 13 is formed to protrude from the inner surface 6 of the first wall portion 4 of the hand drying chamber 2, shortening the distance between the hand and the air nozzle portion 13, and increasing the hand insertion opening 9 and The area of the side opening portion 10. Therefore, the wind speed of the air flow containing the water droplets flowing out from the hand drying chamber 2 becomes small, so that the amount of water droplets flowing out to the outside of the hand drying chamber 2 can be reduced.

Further, since the air nozzle portion 13 is formed to protrude from the inner surface 6 of the first wall portion 4, the hand drying chamber 2 can be visually viewed from above the hand drying chamber 2 without obstructing the line of sight by the first wall portion 4. Internal, it is therefore appropriate to identify the dryness of the hand.

The second embodiment.

Fig. 11 is a horizontal sectional view showing the hand dryer of the second embodiment. The second wall portion 3 of the hand drying device 81 of the first embodiment has a plate shape as shown in Fig. 5. However, as shown in Fig. 11, the second wall of the hand drying device 82 of the second embodiment The portion 3a has a hollow box-shaped structure having an inner surface 5a in order to increase the strength.

The third embodiment.

Fig. 12 is a horizontal sectional view showing the hand dryer of the third embodiment. The inner surfaces 5, 5a of the second wall portions 3, 3a of the first and second embodiments are planar, but as shown in Fig. 12, the second wall portion of the hand drying device 83 of the third embodiment The horizontal section of the inner surface 5b of 3b is a concave surface. In the concave inner surface 5b of the third embodiment, the air flow containing the water droplets facing the both hands flows out from the side opening portion 10 toward the side of the first wall portion 4, so that the air flow, the water droplets, and the like can be further reduced. The situation of the person. Figure 18 is a horizontal cross-sectional view showing a modification of the hand dryer of the third embodiment. The horizontal cross section of the inner surface 5b of the second wall portion 3b of the hand drying device 83 of the third embodiment is a concave surface. However, as shown in Fig. 18, even the both side portions of the second wall portion 3b are directed toward the first wall. The side of the portion 4 is bent at a right angle, and the same effect as the concave surface can be obtained. Further, the curved portion prevents the water droplets adhering to the inner surface 5b from scattering from the side opening portion 10 to the outside.

The fourth embodiment type.

Fig. 13 is a horizontal sectional view showing the hand dryer of the fourth embodiment. As shown in Fig. 13, the inner surface 5c of the second wall portion 3c of the hand drying device 84 of the fourth embodiment is a convex surface. The convex inner surface 5c of the fourth embodiment allows the air flow containing the water droplets to flow out from the side opening portion 10 toward the front side, so that the water droplets can be prevented from scattering to the wall surface of the hand dryer 84 to contaminate the wall surface. .

The fifth embodiment type.

Fig. 14 is a side view showing the hand dryer of the fifth embodiment. As shown in Fig. 14, the inner surface 5d of the second wall portion 3d of the hand drying device 85 of the fifth embodiment bends the upper portion thereof to the rear side (the side of the first wall portion 4). In the fifth embodiment, the upper surface 5d bent to the rear side causes the air flow flowing out from the hand insertion opening 9 of the hand drying chamber 2 to the direction away from the user, preventing the outflow of air, water droplets, and the like from splashing on the user. .

The sixth embodiment.

Fig. 15 is a side view showing the hand dryer of the sixth embodiment. As shown in Fig. 15, the inner surface 5e of the second wall portion 3e of the hand drying device 86 of the sixth embodiment bends the upper portion thereof to the front side (the side of the user). In the sixth embodiment, the upper surface 5e bent to the front side increases the hand insertion opening of the hand drying chamber 2, and the user can easily insert the hand into the hand drying chamber 2, and the usability is improved.

The seventh embodiment.

Fig. 16 is a side view showing the hand dryer of the seventh embodiment. In the hand drying apparatus of the first to sixth embodiments, the inner surface of the second wall portion is inclined approximately parallel to the air nozzle portion 13 to be forwardly inclined in order to achieve the characteristics of easy insertion of the hand and prevention of splashing of water droplets to the user. As shown in Fig. 16, the hand drying device 87 of the seventh embodiment has the inclination angle of the inner surface 5f of the second wall portion 3f smaller than the front angle of the air nozzle portion 13, and the inner surface 5f of the second wall portion 3f and the air. The distance between the nozzle portions 13 is small at the upper portion and large at the lower portion. The airflow containing the water droplets facing the both hands faces the inner surface 5f of the second wall portion 3f of the seventh embodiment, and is inclined downward. Therefore, the flow of air flowing out from the hand insertion opening 9 can be suppressed, thereby preventing the outflow. Air, water droplets, etc. are sprayed onto the user.

The eighth embodiment.

Fig. 17 is a side view showing the hand dryer of the eighth embodiment. As shown in Fig. 17, the front surface 5g of the second wall portion 3g of the hand drying device 88 of the eighth embodiment is inclined earlier than the front nozzle angle of the air nozzle portion 13, with respect to the inner surface 5g of the second wall portion 3g and the air nozzle. The distance between the portions 13 is larger at the upper portion and smaller at the lower portion. In the hand drying device 88 of the eighth embodiment, the opening of the hand insertion opening 9 of the hand drying chamber 2 is large, and the user can easily insert the hand into the hand drying chamber 2, and the usability is improved.

Further, in the first to eighth embodiments of the present invention, the hand insertion opening 9 is provided in the upper portion of the hand drying chamber 2, the first wall portion 4 is provided in the rear portion of the hand drying chamber 2, and the second wall portion is 3 to 3 g. Provided in the front portion of the hand drying chamber 2, the pair of air nozzle portions 13 extend in the up and down direction on the side of the first wall portion 4. However, the hand drying device of the present invention is not limited to this type, and may not be a pair of air. The nozzle portion is provided in the first wall portion 4 and is provided in the second wall portion 3.

Further, the hand insertion opening 9 may be provided in the front portion of the hand drying chamber 2, the first wall portion 4 may be provided in the upper portion of the hand drying chamber 2, and the second wall portion 3 may be placed in the lower portion of the hand drying chamber 2, and a The air nozzle portion is provided on either the side of the first wall portion 4 and the side of the second wall portion 3 and is provided to extend in the front-rear direction. Further, the side opening portion 10 of the hand drying chamber 2 may not be provided and the side may be plugged.

[Industry profitability]

As described above, the hand drying device of the present invention can be applied to a hand drying device which performs a drying process on a hand which is wet after washing by a jet of a high-speed air stream.

1. . . Body shell

2. . . Hand drying room

3,3a,3b,3c,3d,3e,3f,3g. . . Second wall

4. . . First wall

5,5a,5b,5c,5d,5e,5f,5g. . . Inner surface of the second wall

6. . . Inner surface of the first wall

8. . . Bottom

9. . . Hand insertion

10. . . Lateral opening

11. . . High pressure air flow generating device

12. . . Air duct

13,13a. . . Air nozzle

14. . . High speed air flow

15. . . Drainage port

16. . . Drain pipe

17. . . Drainage channels

18. . . Control circuit

19. . . Suction port

20. . . Suction channel

twenty one. . . suction point

twenty two. . . Hand detection sensor

24, 24a, 24b. . . Air outlet

25. . . filter

81,82,83,84,85,86,87,88. . . Hand dryer

Fig. 1 is a side view showing a first embodiment of the hand dryer according to the present invention.

Fig. 2 is a front elevational view showing the hand dryer of the first embodiment.

Fig. 3 is a side view showing the state in which the hand is inserted and smashed in the hand dryer of the first embodiment.

Fig. 4 is a vertical sectional view showing the relative position of the air nozzle portion of the hand drying device of the first embodiment and the inserted hand.

Fig. 5 is a horizontal sectional view taken along line A-A of Fig. 1.

Fig. 6 is a view showing an air ejection port of the hand dryer of the first embodiment.

Fig. 7 is a view showing a modification of the air ejection port of the hand dryer of the first embodiment.

Fig. 8 is a view showing another modification of the air ejection port of the hand dryer of the first embodiment.

Fig. 9 is a view showing still another modification of the air ejection port of the hand dryer of the first embodiment.

Fig. 10 is a side view showing a modification of the air nozzle portion of the hand dryer of the first embodiment.

Fig. 11 is a horizontal sectional view showing the hand dryer of the second embodiment.

Fig. 12 is a horizontal sectional view showing the hand dryer of the third embodiment.

Fig. 13 is a horizontal sectional view showing the hand dryer of the fourth embodiment.

Fig. 14 is a side view showing the hand dryer of the fifth embodiment.

Fig. 15 is a side view showing the hand dryer of the sixth embodiment.

Fig. 16 is a side view showing the hand dryer of the seventh embodiment.

Fig. 17 is a side view showing the hand dryer of the eighth embodiment.

Figure 18 is a horizontal cross-sectional view showing a modification of the hand dryer of the third embodiment.

2. . . Hand drying room

3. . . Second wall

4. . . First wall

5. . . Inner surface of the second wall

6. . . Inner surface of the first wall

10. . . Lateral opening

12. . . Air duct

13. . . Air nozzle

14. . . High speed air flow

twenty four. . . Air outlet

81. . . Hand dryer

Claims (13)

A hand drying device, comprising: a hand drying chamber having: a hand insertion opening for inserting left and right hands in parallel; a first wall portion facing the back of the hand inserted side by side from the hand insertion opening; the second wall portion, and the slave The hand insertion port is inserted into the palm and the first wall portion facing each other; and the pair of air nozzle portions are on the side of the first wall portion or the second wall portion, spanning about the entire length of the hand and along the above a hand insertion opening extending in a depth direction of the hand drying chamber, wherein the pair of air nozzle portions discharge a high-speed air flow toward the hand drying chamber, wherein the arrangement of the pair of air nozzle portions in the horizontal direction is The interval on the side of the hand insertion opening is wider, and the interval on the side in the deep side is arranged in a V shape. The hand dryer according to claim 1, wherein the pair of air nozzle portions are disposed in a manner that is approximately parallel to the respective finger directions of the inserted hands. The hand dryer according to claim 1, wherein the hand insertion opening is provided in an upper portion of the hand drying chamber, the first wall portion is disposed at a rear portion of the hand drying chamber, and the second wall portion is disposed at the hand In the front portion of the drying chamber, the pair of air nozzle portions extend in the vertical direction on the side of the first wall portion. The hand dryer according to claim 3, wherein the pair of air nozzle portions are disposed such that an upper portion is located on the front side and a lower portion is located on the rear side and is inclined forward. A hand dryer according to claim 3, wherein the pair of air nozzle portions discharge a high-speed air stream obliquely downward. The hand drying device according to claim 3, wherein the inner surface of the second wall portion is formed in such a manner that the upper portion is located on the front side and the lower portion is located on the rear side and is inclined forward. The hand dryer according to claim 3, wherein a distance between an inner surface of the second wall portion and the pair of air nozzle portions is approximately fixed across a total length of the air nozzle portion. The hand dryer according to claim 3, wherein the distance between the inner surface of the second wall portion and the pair of air nozzle portions is small and the lower portion is large. The hand dryer according to claim 3, wherein the distance between the inner surface of the second wall portion and the pair of air nozzle portions is larger, and the lower portion is smaller. The hand drying device of claim 3, wherein the upper surface of the inner surface of the second wall portion is curved to the rear side. The hand drying device of claim 3, wherein the upper surface of the inner surface of the second wall portion is curved to the front side. The hand drying device of claim 3, wherein the horizontal cross section of the inner surface of the second wall portion is a concave surface. The hand drying device of claim 3, wherein the horizontal section of the inner surface of the second wall portion is a convex surface.