JP2012061147A - Hand dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hand dryer with reduced noise while suppressing cost increases.SOLUTION: The hand dryer includes: a high pressure airflow generator for generating a high pressure airflow; an internal casing for storing the high pressure airflow generator; an external casing for accommodating the internal casing and serving as the outer shell of a body, and at least one surface of which is opened; a hand drying chamber provided in the opening of the external casing; a nozzle disposed in the hand drying chamber; an external air-suction opening provided in the external casing, and for taking air in; a suction air path forming an air path from the external air-suction opening to the internal casing; an internal air-suction opening 10 disposed to a windward of the internal casing; an exhaust air path forming an air path from the internal casing to the nozzle; and an internal exhaust opening disposed on the leeward of the internal casing. The opening shape of the internal air-suction opening has a plurality of recessed and protruded portions. Each of the plurality of recessed portions is arranged to make substantially internal contact with a virtual circle 19a.

Description

  The present invention relates to a hand-drying apparatus that blows air on a wet hand after washing to dry hygienically.

  Hygienic hand dryers have been developed that do not wipe the wet hands after washing with a towel, handkerchief or the like, but blow away moisture by spraying high-speed airflow. In a hand dryer using a high-pressure airflow generator, the sound generated from the high-pressure airflow generator is one of the main causes of product noise. Further, it is known that noise generated from the high-pressure airflow generator diffracts in the air passage and escapes from the air suction port.

  For example, Patent Document 1 discloses a technique for reducing noise by providing a cylindrical silencer having a sound absorbing material attached inside in the vicinity of a suction port of a high-pressure airflow generator.

  For example, Patent Document 2 discloses a technique for reducing noise by rectifying air with a sound absorbing material at a suction port of a high-pressure airflow generation device.

  For example, Patent Document 3 discloses a technique for reducing noise by using a material of an intake air passage as a continuous pore type foamed resin molded product.

JP 2001-252217 A JP 2006-75498 A JP 2004-305287 A

  However, the techniques disclosed in Patent Literature 1 and Patent Literature 2 have a problem of increasing costs because it is necessary to affix a sound absorbing material. Moreover, since the area where the sound absorbing material is affixed is a negative pressure area, if the sound absorbing material is peeled off, the sound absorbing material may be sucked into the high-pressure airflow generator and cause a failure.

  Further, in the technique disclosed in Patent Document 3, since a special resin must be used for the intake air passage, the air passage and the exterior parts must be separated, which increases the number of parts and increases the cost. there were.

  This invention is made | formed in view of the above, Comprising: It aims at obtaining the hand dryer which can aim at low noise, suppressing a cost increase.

  In order to solve the above-described problems and achieve the object, the present invention provides a high-pressure airflow generation device that generates a high-pressure airflow, an internal housing that houses the high-pressure airflow generation device, An outer casing that forms an outer shell and is open at least on one side, a hand drying chamber provided in the opening of the outer casing, a nozzle disposed in the hand drying chamber, and an air provided in the outer casing. An external air inlet, an intake air passage that forms an air path from the external air inlet to the internal housing, an internal air inlet that is arranged on the wind of the internal housing, and an air passage from the internal housing to the nozzle are formed. And an internal exhaust port disposed on the lee side of the internal housing. The opening shape of the internal intake port has a plurality of irregularities, and each concave part is substantially inscribed in one virtual circle. It is characterized by being arranged in.

  According to the present invention, it is possible to suppress an increase in cost while reducing noise by the shape of the opening of the internal intake port.

FIG. 1 is a cross-sectional view showing a schematic configuration of a hand-drying apparatus according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing the opening shape of the internal intake port. FIG. 3 is a diagram showing noise comparison data. FIG. 4 is a diagram illustrating an opening shape of the internal intake port according to the first modification of the first embodiment. FIG. 5 is a cross-sectional view illustrating another product example of the hand-drying apparatus according to the first embodiment. FIG. 6 is a diagram illustrating an opening shape of the internal air inlet formed in the hand dryer according to the second embodiment of the present invention.

  Below, the hand dryer concerning embodiment of this invention is demonstrated in detail based on drawing. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a schematic configuration of a hand-drying apparatus according to Embodiment 1 of the present invention. The hand dryer 20 includes an outer casing 1 that forms an outer shell of the main body and has an open space above. A hand drying chamber 2 is provided at the opening of the external housing 1. A front nozzle 3 is disposed on the front wall surface of the hand drying chamber 2. A rear nozzle 4 is disposed on the rear wall surface of the hand drying chamber 2.

  The hand drying chamber 2 is provided with a lower sensor 5 that detects that the user's hand has been inserted and an upper sensor 6 that detects that the hand has been removed. Below the external housing 1 is provided an external air inlet 7 for sucking air from the surroundings.

  The external housing 1 incorporates a high-pressure airflow generator 8 that generates a high-pressure airflow. The axis of the high-pressure airflow generation device 8 is substantially perpendicular to the height direction of the external housing 1 and is arranged so that the suction port faces the back side of the external housing 1. The high-pressure airflow generator 8 is covered with an internal housing 9, and has openings on the windward and leeward sides. The windward opening is the internal air inlet 10, and the leeward opening is the internal air outlet 11.

  An air passage is formed inside the outer casing 1, and an intake air passage 1 a from the external air inlet 7 to the internal air inlet 10, and an exhaust air passage from the internal air outlet 11 to the front nozzle 3 and the rear nozzle 4. 1b.

  The intake air passage 1 a is provided with a tachi 12 that prevents air from being drawn in a straight line from the external intake port 7 to the internal intake port 10. A circuit 13 for driving the high-pressure airflow generator 8 is disposed at a position facing the tachi 12 across the intake air passage 1a. The circuit 13 protrudes the cooling fin 14 into the air path.

  When a hand is inserted into the hand drying chamber 2, the lower sensor 5 detects that the hand has been inserted. When the lower sensor 5 detects that a hand has been inserted, a signal is sent from the circuit 13 and the high-pressure airflow generator 8 is driven. When the high-pressure airflow generator 8 is driven, ambient air is sucked from the external intake port 7.

  A filter 15 is provided at the external air inlet 7. Dust and dust contained in the ambient air are captured by the filter 15 when passing through the external air inlet 7. Thereby, it can suppress that the dust and garbage which are contained in ambient air are attracted | sucked in the apparatus of the hand-drying apparatus 20. FIG.

  The air that has flowed upward through the intake air passage 1a is blocked by the tachi 12 so that it is directed to the high-pressure airflow generator while changing the flow direction forward, upward, backward, and upward.

  Therefore, the air velocity is larger in the outer region away from the tachi 12 than in the inner region. That is, the wind speed of air increases in the area where the cooling fins 14 are provided. As a result, the cooling fins 14 are easily cooled, and the cooling efficiency of the circuit 13 can be improved.

  The air that has passed through the tachi 12 is sucked into the internal air inlet 10. FIG. 2 is a diagram showing the opening shape of the internal air inlet 10. The opening of the internal air inlet 10 has a shape having a plurality of concaves and convexes, and each concave part is arranged so as to be substantially inscribed in one circular shape (virtual circle 19a). Each convex portion is also arranged so as to be substantially inscribed in one circle (virtual circle 19b). Moreover, the opening area of the internal intake port 10 is smaller than the cross-sectional area of the intake air passage 1a. Since air is contracted at the internal intake port 10, the flow path length of the internal intake port 10 is preferably 5 mm or less.

  The air sucked up to the internal housing 9 becomes compressed air by the high-pressure airflow generator 8 and flows through the internal exhaust port 11 to the exhaust air passage 1b. In the exhaust air passage 1b, the compressed air is divided into a flow toward the front exhaust air passage 16 and a flow toward the rear exhaust air passage 17. The compressed air flows through the front exhaust air passage 16 and the rear exhaust air passage 17, and is blown out as a nozzle jet from the front nozzle 3 and the rear nozzle 4, respectively.

  Thus, when the nozzle jet hits the user's hand, the water droplets adhering to the user's hand are blown off, and the user can dry his hand.

  The noise source of the hand dryer 20 is mainly generated by a jet sound caused by a nozzle jet, a rotational sound generated by driving the high-pressure air flow generator 8, and an intake sound generated when air is sucked from the external intake port 7. It is. The rotating sound generated by driving the high-pressure airflow generator 8 is classified into a transmitted sound that passes through the external housing 1 and generates noise outside, and a diffracted sound that travels around the air path and generates noise outside. The

  The rotational sound of the high-pressure airflow generator 8 has the highest sound pressure level generated in the suction direction. Since this rotating sound includes noise in a low frequency band, it is difficult to perform sound insulation even if a sound absorbing material or a shielding plate is used. Since the rotational sound of the high-pressure airflow generator 8 has a high transmittance, in order to reduce the noise reaching the user, the suction direction of the high-pressure airflow generator 8 is opposite to the user, that is, the external housing 1. It is preferable to face in the back direction.

  A reflector 18 such as resin or sheet metal is disposed immediately below the suction port of the high-pressure airflow generator 8. If the sound generated from the high-pressure airflow generator 8 is the incident sound, and the sound generated when the incident sound is reflected by the reflecting plate 18 is the reflected sound, the incident sound and the reflected sound are offset by placing resin or sheet metal, and the noise is reduced. Can be reduced. Since a cancellation with the reflected sound does not occur except under the high pressure airflow generator 8, it is preferable to attach a sound absorbing material.

  As the opening area of the internal air inlet 10 is smaller, the diffracted sound is reduced and the noise is reduced. However, since the pressure loss increases when the opening area is too small, the opening area is preferably such that the wind speed of the internal intake port 10 is 10 to 15 m / s.

  In the high-pressure airflow generation device 8 and the internal air inlet 10, the wind speed of the sucked air is high, and pressure fluctuations periodically occur. In a general round hole inlet, the phases of pressure fluctuations coincide with each other, and noise may be increased by strengthening each other.

  As shown in FIG. 2, the outer shape of the internal air inlet 10 has irregularities periodically repeated at an equal pitch. Due to the unevenness, the phase of the pressure fluctuation is shifted between the adjacent unevennesses, so that it becomes difficult for the noises to strengthen each other, and the noise can be reduced.

  The difference between the concave and convex diameters in the opening shape of the internal air inlet 10 is large, and the pressure loss increases as the period becomes shorter. When the wind speed is slow, the difference between the concave and convex diameters is large and the period is shorter, and the noise reduction effect is greater. However, when the wind speed is fast, the difference between the concave and convex is smaller and the period is longer, the noise reduction effect is greater.

  In FIG. 2, the unevenness of the opening shape of the internal air inlet 10 is constituted by a continuous body that repeats substantially semicircles of the same diameter that face each other. FIG. 2 shows an example of an opening shape with a pitch interval of 20 degrees. FIG. 3 is a diagram showing noise comparison data in which the shape of the internal intake port of the first embodiment is an uneven shape and the shape of a conventional air supply port is a round hole shape. From this evaluation result, it was confirmed that the present invention has a noise reduction effect in a high frequency band of 4000 Hz or higher. In addition, the cost can be reduced by suppressing an increase in the number of parts.

  In addition, the unevenness | corrugation of the opening shape of the internal inlet 10 is not restricted to the case where it is comprised by the continuous body which repeats the substantially semicircle of the same diameter which opposes, For example, you may comprise by the continuous body of a sine wave.

  The diffracted sound that could not be reduced by the reflector 18 reaches the tachi 12. Since the tachi 12 prevents the sound from propagating in a straight line and propagates after being diffracted, noise can be reduced by diffraction attenuation. In addition, since sound is frequently incident and reflected on the air path surface at the bent part of the air path, noise can be efficiently absorbed by attaching a sound absorbing material to the bent part. In the bent portion, it is possible to efficiently absorb sound by increasing the thickness of the sound absorbing material on the surface facing the high-pressure air flow generator 8.

  FIG. 4 is a diagram illustrating an opening shape of the internal air inlet 10 according to the first modification of the first embodiment. In this modification, as shown in FIG. 4, the opening of the internal air inlet 10 has a shape having a plurality of irregularities, and each concave part is disposed so as to be substantially inscribed in one circular shape (virtual circle 19 a). However, each convex part is not inscribed in one circle, and variation is provided in the protrusion amount. As described above, the internal air inlet 10 may be formed so that either one of the concave portion or the convex portion is substantially inscribed in one circle.

  The opening shape of the internal air inlet 10 is not limited to the case where the irregularities are arranged at an equal pitch, and the irregularities may be arranged at an irregular pitch.

  Moreover, in this Embodiment 1, although the product of the type from which a jet flow blows off from the nozzle of the near side and the back direction was illustrated and demonstrated, it is not limited to this type of product. For example, as shown in FIG. 5, the shape of the internal air inlet 10 as described above can also be applied to a hand dryer 20 of a type in which a jet is blown only from the upper nozzle 23 in one direction.

Embodiment 2. FIG.
FIG. 6 is a diagram illustrating an opening shape of the internal air inlet formed in the hand dryer according to the second embodiment of the present invention. Since the configuration other than the internal intake port 24 is the same as that described in the first embodiment, illustration and detailed description thereof are omitted.

  In the second embodiment, as shown in FIG. 6, the opening shape of the internal intake port 24 is formed in an uneven pitch shape having no periodicity. Since the opening shape of the internal intake port 24 is formed in a concavo-convex shape having no period, not only can the phase of pressure fluctuation of adjacent concavo-convex parts be varied, but also the phase of pressure fluctuation in each period can be shifted. Further noise suppression can be achieved.

  The internal intake port 24 is formed such that its convex portion is inscribed in the virtual circle 19b. The concave portion may be formed so as to be inscribed in the virtual circle, or both the concave portion and the convex portion may be formed so as to be inscribed in the virtual circle.

  As described above, the hand dryer according to the present invention is useful for a hand dryer that blows air to dry hands.

DESCRIPTION OF SYMBOLS 1 External housing | casing 1a Intake air path 1b Exhaust air path 2 Hand drying chamber 3 Front nozzle 4 Back nozzle 5 Lower sensor 6 Upper sensor 7 External intake port 8 High pressure air flow generator 9 Internal housing 10 Internal intake port 11 Internal exhaust port 12 Tachi 13 Circuit 14 Cooling fin 15 Filter 16 Front exhaust air path 17 Rear exhaust air path 18 Reflector 19a Virtual circle 19b Virtual circle 20 Hand dryer 23 Upper nozzle 24 Internal intake port

Claims (6)

A high-pressure airflow generator that generates a high-pressure airflow;
An internal housing that houses the high-pressure airflow generator;
An outer casing that houses the inner casing and forms an outer shell of the main body, and is open at least on one surface;
A hand drying chamber provided in the opening of the external housing;
A nozzle disposed in the hand drying chamber;
An external air inlet provided in the external housing for sucking air;
An intake air passage that forms an air passage from the external intake port to the internal housing;
An internal air inlet arranged on the windward side of the internal housing;
An exhaust air passage that forms an air passage from the inner housing to the nozzle;
An internal exhaust port disposed leeward of the internal housing,
The opening shape of the internal air inlet has a plurality of irregularities, and each of the concave portions is disposed so as to be substantially inscribed in one virtual circle. A high-pressure airflow generator that generates a high-pressure airflow;
An internal housing that houses the high-pressure airflow generator;
An outer casing that houses the inner casing and forms an outer shell of the main body, and is open at least on one surface;
A hand drying chamber provided in the opening of the external housing;
A nozzle disposed in the hand drying chamber;
An external air inlet provided in the external housing for sucking air;
An intake air passage that forms an air passage from the external intake port to the internal housing;
An internal air inlet arranged on the windward side of the internal housing;
An exhaust air passage that forms an air passage from the inner housing to the nozzle;
An internal exhaust port disposed leeward of the internal housing,
The opening shape of the internal air inlet has a plurality of irregularities, and each of the convex portions is arranged so as to circumscribe one virtual circle.   The hand dryer according to claim 1, wherein the unevenness of the opening shape of the internal air inlet is arranged at an equal pitch.   The hand dryer according to claim 1, wherein the irregularities of the opening shape of the internal air inlet are arranged at unequal pitches.   The hand dryer according to claim 3 or 4, wherein the unevenness of the opening shape of the internal air inlet is configured by a sine wave continuum.   The hand-drying device according to claim 3 or 4, wherein the irregularities of the opening shape of the internal intake port are constituted by a substantially semicircular continuous body that is alternately opposed.

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