Hand dryer and control method thereof

Abstract

This hand-drying device (1) comprises: a nozzle (30) that blows air toward a drying space (32) where a hand is to be disposed; a blowing unit (40) that sends out air blown from the nozzle (30); a hand-sensing unit (50) that senses whether or not there is a hand disposed in the drying space (32); and a control unit (60) that controls operation of the blowing unit (40) such that the air speed of the air blown from the nozzle (30) reaches a preset drying air speed when the hand-sensing unit (50) senses that a hand is present, controls operation of the blowing unit (40) such that the air speed of the air blown from the nozzle (30) reaches a preset warming air speed from the drying air speed when the hand-sensing unit (50) senses that no hand is present after having sensed that a hand was present, and prevents operation of the blowing unit after operation of the blowing unit has continued for a preset time.

Description

[Technical Field]

[0001] The present disclosure relates to a hand dryer and a method for controlling the same. [Background technology]

[0002] Hand dryers that blow air to dry a user's hands are widely used. For example, Patent Document 1 describes a conventional hand dryer that includes a main body, a high-pressure airflow generator that draws external air into the main body, a nozzle provided on the main body that sprays high-pressure air from the high-pressure airflow generator as high-velocity air, a support member that supports the main body, and a fixing member that attaches the support member to a detergent mounting arm attached to a sink or washbowl and fixes the support member to the detergent mounting arm.

[0003] Hand dryers are generally equipped with a hand detection sensor that detects the presence or absence of a user's hands. When the hand detection sensor detects a hand, the high-pressure airflow generator is activated, and high-velocity air is sprayed from the nozzle toward the hand to dry it. When the user removes their hand from the hand dryer, the hand detection sensor no longer detects the hand, and the high-pressure airflow generator stops, stopping the spray of high-velocity air. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-272086 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional hand dryers, because the position of a user's hands during drying and the direction and speed at which their hands are removed at the end of drying vary from user to user, it was difficult to stop the high-pressure airflow generator once the high-speed airflow no longer hits the user's hands, even with a hand detection sensor. Therefore, to ensure that the high-speed airflow continues to hit the user's hands until the end and dry the entire hand, the high-pressure airflow generator continues to operate for a certain period of time after the hand detection sensor changes from a detected state to a non-detected state, and then the high-pressure airflow generator is stopped after the certain period of time has elapsed. This stops the high-speed airflow sprayed from the nozzle once the hands are reliably removed from the drying space below the nozzle.

[0006] In this configuration, when drying hands, the high-speed airflow emitted from the nozzle collides with the hands, causing it to slow down significantly and disperse in all directions. Therefore, the speed of the high-speed airflow when it collides with the washbasin after colliding with the hands is low. However, after the hands are removed from the drying space, the high-speed airflow emitted from the nozzle does not slow down by hitting the hands, but instead collides directly with the washbasin. This causes the high-speed airflow to bounce back toward the user upon impact with the washbasin, causing discomfort to the user and scattering water droplets in the washbasin around, wetting the counter on which the washbasin is placed, for example.

[0007] The present disclosure has been made to solve the above-mentioned problems, and provides a hand dryer and a control method thereof that suppresses the rebound of airflow and the scattering of water droplets after hands are pulled out of the drying space, thereby reducing discomfort to the user. [Means for solving the problem]

[0008] The hand dryer according to the present disclosure includes: a nozzle that blows air toward a drying space where hands are placed; A washbasin to receive water,The drying device comprises a blower unit that sends out air blown out from the nozzle, a hand detection unit that detects the presence or absence of a hand placed in the drying space, and a control unit that, when the hand detection unit detects the presence of a hand, controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle becomes a preset drying wind speed, and, when the hand detection unit detects the presence of a hand but then detects that the hand is not present, controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle changes from the drying wind speed to a preset relaxation wind speed, and continues operating the blower unit for a preset period of time, and then stops the operation of the blower unit.

[0009] The method for controlling a hand dryer according to the present disclosure also includes: a nozzle that blows air toward a drying space where hands are placed; A washbasin to receive water, A control method for a hand dryer having a blower unit that sends out air blown out from a nozzle, a hand detection unit that detects the presence or absence of a hand placed in a drying space, and a control unit that controls the operation of the blower unit based on the detection result of the hand detection unit, comprising: a step in which, when the hand detection unit detects the presence of a hand, the control unit controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle becomes a preset drying wind speed; a step in which, when the hand detection unit detects the presence of a hand but then detects the absence of a hand, the control unit controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle changes from the drying wind speed to a preset relaxation wind speed; a step in which the control unit continues operation of the blower unit that blows air out from the nozzle at the relaxation wind speed for a preset period of time; and a step in which the control unit stops operation of the blower unit that has continued for the preset period of time. [Effects of the Invention]

[0010] According to the present disclosure, when the hand detection unit detects that a hand is present and then subsequently detects that a hand is not present, the wind speed of the air blown out from the nozzle changes from a drying wind speed to a relaxation wind speed, thereby suppressing the rebound of the air flow and the scattering of water droplets after the hand is pulled out of the drying space, thereby reducing the discomfort felt by the user. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a right side view of the hand dryer according to the embodiment. [Figure 2] 1 is a plan view of a washbasin on which a hand drying device according to an embodiment is installed. [Figure 3] FIG. 2 is a bottom view of the casing of the hand dryer according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. [Figure 5] FIG. 4 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 2 is a block diagram showing the configuration of a control function of the hand dryer according to the embodiment; FIG. [Figure 8] 10 is a table showing an example of the relationship between the distance between the nozzle of the hand drying device according to the embodiment and the bottom surface of the washbasin and the relaxation air speed. [Figure 9] 2 is a diagram illustrating an example of a hardware configuration of a processing circuit of a control unit of a hand dryer according to an embodiment. FIG. [Figure 10] 4 is a flowchart of operation control of the hand dryer according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described with reference to the accompanying drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0013] Embodiment FIG. 1 is a right side view of a hand dryer 1 in this embodiment. FIG. 2 is a plan view of a bathroom sink 10 on which the hand dryer 1 is installed. FIG. 3 is a bottom view of a casing 20 of the hand dryer 1. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a cross-sectional view taken along line VV in FIG. 3. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 4. FIGS. 1 and 2 show the hand dryer 1 installed on the bathroom sink 10.

[0014] The washbasin 10 has a washbasin 12. In this embodiment, the washbasin 10 is installed on the floor FL adjacent to the wall WL of the building. The washbasin 12 is formed in a bowl shape so that it can receive and store water. A drain outlet 14 is formed at the bottom of the washbasin 12. A drain pipe 16 is connected below the drain outlet 14. The drain pipe 16 has a drain trap (not shown) and is connected to the sewer system via the drain trap.

[0015] The washbasin 10 is provided with a water outlet 18. The water outlet 18 is positioned so as to discharge water toward the inside of the washbasin bowl 12. In this embodiment, the water outlet 18 is provided so as to extend in a direction facing the user who will be using the washbasin 10. The water outlet 18 is, for example, a faucet connected to a water pipe. The water outlet 18 penetrates the wall 11 of the washbasin 10 and is connected to a water supply system for supplying the water to be discharged. The water outlet 18 has a conventional sensor, control circuit, and solenoid valve (not shown). When this sensor detects the user's hand, the solenoid valve automatically opens, and water is discharged from the water outlet 18.

[0016] The hand dryer 1 includes a nozzle 30, a blower 40, a hand detector 50, and a controller 60.

[0017] The nozzle 30 blows air toward the drying space 32 where the user's hands are placed. In this embodiment, the nozzle 30 is provided in the casing 20 of the hand dryer 1. The casing 20 is disposed above the washbasin 12. Specifically, the casing 20 extends from the outside of the washbasin 12 toward above the washbasin 12, with the tip of the casing 20 located above the washbasin 12. In this embodiment, the casing 20 has a substantially cylindrical outer shape and extends above the washbasin 12 from the wall 11 of the sink 10 in a direction facing the user who will be using the sink 10. The portions of the casing 20 that protrude from the wall 11 of the sink 10 are arranged in parallel near the water outlet 18. The base end of the casing 20 is inserted into a through-hole provided in the wall 11 of the sink 10 and is fixed to the wall 11 using a fixing nut (not shown).

[0018] As shown in FIGS. 4 to 6 , the casing 20 includes an outer tube portion 22 and an inner tube portion 24. The outer tube portion 22 constitutes the outer shape of the casing 20 and is formed in a generally cylindrical shape with an internal space. The inner tube portion 24 is disposed in the internal space of the outer tube portion 22 and is formed in a generally cylindrical shape with an internal space that constitutes an air passage 26 for sending air to the nozzle 30. The tip of the inner tube portion 24 is disposed at a distance from the tip of the outer tube portion 22, and a tip-side space 28a is provided between the tip of the inner tube portion 24 and the tip of the outer tube portion 22, in which a hand detection unit 50 (described later) is disposed. The inner tube portion 24 also includes a recess 24a, which is a recess in a portion of the outer peripheral surface of the inner tube portion 24, extending along the extension direction of the casing 20. This provides an external air passage space 28b between the recess 24a of the inner tube portion 24 and the inner peripheral surface of the outer tube portion 22. The external air passage space 28b is in communication with the tip-side space 28a. At the base end of the casing 20, the outer diameter of the inner tube portion 24 is smaller than the inner diameter of the outer tube portion 22, and the central axis of the inner tube portion 24 is offset from the central axis of the outer tube portion 22. As a result, an external air passage space 28c is provided between the outer peripheral surface of the inner tube portion 24 and the inner peripheral surface of the outer tube portion 22. The external air passage space 28c is in communication with the external air passage space 28b. The external air passage space 28b and the external air passage space 28c are used as spaces for passing signal lines to the hand detection unit 50 and the like disposed in the tip end space 28a. The inner tube portion 24 is fixed to the outer tube portion 22, for example, by screwing.

[0019] The nozzle 30 communicates with the air passage 26 of the inner cylinder portion 24. In this embodiment, the nozzle 30 is provided on the underside of the casing 20, and blows air downward from the casing 20. Therefore, the drying space 32 is the spatial region below the casing 20. Because the washbasin 12 is provided below the casing 20, the air blown out from the nozzle 30 ultimately collides with the washbasin 12.

[0020] In this embodiment, the nozzle 30 is formed as an elongated slit extending linearly in the extension direction of the casing 20. The slit width of the nozzle 30 is set to, for example, 2 mm or less. The nozzle 30 may have a shape in which a plurality of elongated slits are arranged in parallel as shown in FIG. 3, or may have a shape in which circular holes are arranged in a row instead of slits.

[0021] The blower 40 delivers air blown out from the nozzle 30. In this embodiment, the blower 40 is housed in a box 42 attached to the wall WL below the sink 10. The blower 40 functions as a high-pressure air generator and includes, for example, a fan casing, a fan body such as a turbofan housed in the fan casing, and a fan motor for rotating the fan body. The blower 40 is configured to draw air through an air inlet (not shown) to generate high-pressure air. A removable air filter (not shown) is provided at the air inlet to capture dust, dirt, and the like in the air. The air filter may be, for example, a resin mesh or a metal mesh, or a HEPA (High Efficiency Particulate Air) filter capable of capturing finer dust particles.

[0022] One end of an air duct 44 is connected to the discharge side of the air blower 40. The other end of the air duct 44 is connected to the base end of the casing 20, more specifically the base end of the inner cylindrical portion 24. The air duct 44 is a tubular member that passes air through its interior. The high-pressure air generated by the air blower 40 passes from the air duct 44 through the air passage 26 of the inner cylindrical portion 24 of the casing 20 and is blown out from the nozzle 30. The air duct 44 is molded from resin and has a flexibly bendable bellows structure or the like to facilitate installation.

[0023] The box 42 is also provided with a heater (not shown) that heats the high-pressure air generated by the blower 40. By using this heater, the air blown out from the nozzle 30 can be made into warm air.

[0024] A power switch 43a, an air volume switch 43b, and a heater switch 43c are provided on the surface of the box 42. The power switch 43a is a switch for turning the power of the hand dryer 1 on and off. The air volume switch 43b is a switch for switching the wind speed of the air blown out from the nozzle 30 between multiple levels. The heater switch 43c is a switch for turning the heater described above on and off.

[0025] The hand detection unit 50 detects the presence or absence of a hand placed in the drying space 32. In this embodiment, the drying space 32 is a spatial region below the casing 20. More specifically, the hand detection unit 50 detects the presence or absence of a hand inserted between the casing 20 and the washbasin 12. The hand detection unit 50 is provided in the casing 20 near the nozzle 30. The hand detection unit 50 is also located on the casing 20 closer to the user than the nozzle 30. This location allows for better detection of the user's hand, improving usability. In this embodiment, as shown in FIGS. 3 and 6 , the hand detection unit 50 is housed in the tip space 28a of the casing 20 and located on the underside of the casing 20 closer to the user than the nozzle 30. The hand detection unit 50 can use, for example, an optical infrared sensor, a distance sensor, or a capacitance sensor as a sensor for detecting a hand.

[0026] The control unit 60 controls the operation of the blower unit 40 based on the detection result of the hand detection unit 50. In this embodiment, as shown in FIG. 1, the control unit 60 is provided inside the box body 42. FIG. 7 is a block diagram showing the configuration of the control function of the hand dryer 1. The control unit 60 is electrically connected to both the blower unit 40 and the hand detection unit 50. The hand detection unit 50 outputs a hand detection signal indicating whether a hand has been detected in the drying space 32 and sends it to the control unit 60. The control unit 60 controls the operation of the blower unit 40 based on the hand detection signal output from the hand detection unit 50. For example, when the hand detection unit 50 detects the presence of a hand, the control unit 60 activates the blower unit 40. This generates high-pressure air in the blower unit 40 and sends it to the nozzle 30 through the air duct 44. The nozzle 30 converts the high-pressure air generated by the blower unit 40 into a high-velocity airflow and blows it toward the drying space 32. At this time, the control unit 60 controls the operation of the blower unit 40 so that the wind speed of the air blown out from the nozzle 30 becomes a preset drying wind speed. The drying wind speed is set to, for example, 80 m / s or higher. The control unit 60 changes the rotation speed of the fan body of the blower unit 40, thereby changing the pressure generated in the blower unit 40 and changing the speed of the air blown out from the nozzle 30. Furthermore, for example, when the hand detection unit 50 detects that no hand is present, the control unit 60 does not operate the blower unit 40 and keeps the operation of the blower unit 40 stopped.

[0027] Furthermore, when hand detection unit 50 detects the presence of a hand and then detects the absence of a hand, control unit 60 controls the operation of blower unit 40 so that the wind speed of the air blown out from nozzle 30 changes from the drying wind speed to a preset relaxation wind speed. Then, control unit 60 continues the operation of blower unit 40 for a preset time, and then stops the operation of blower unit 40.

[0028] The relaxation air speed is set to a speed lower than the drying air speed. In this embodiment, for example, three levels of air speed are set as the relaxation air speed, as shown in FIG. 8. FIG. 8 is a table showing an example of the relationship between the distance L1 between the nozzle 30 and the bottom surface of the washbasin 12 and the relaxation air speed. For example, three air volume notches, "strong," "medium," and "weak," are set to set the operating state of the air blower 40. When the air volume notch is "strong," the operation of the air blower 40 is controlled so that the air blown from the nozzle 30 has the highest wind speed (high speed) of the three wind speeds. When the air volume notch is "medium," the operation of the air blower 40 is controlled so that the air blown from the nozzle 30 has a wind speed (medium speed) lower than the high speed. When the air volume notch is "weak," the operation of the air blower 40 is controlled so that the air blown from the nozzle 30 has a wind speed (low speed) lower than the medium speed. In this embodiment, the relaxation air velocity is set based on the distance L1 between the nozzle 30 and the bottom surface of the washbasin 12, which will be described later.

[0029] The functions of the control unit 60 are realized, for example, as a processing circuit having a hardware configuration shown in FIG. 9. FIG. 9 is a diagram showing an example of the hardware configuration of the processing circuit. The functions of the control unit 60 are realized, for example, by the processor 62 shown in FIG. 9 executing a program stored in the memory 64. The functions may also be realized by multiple processors and multiple memories working together. Some of the functions of the control unit 60 may be implemented as electronic circuits, and other parts may be realized using the processor 62 and the memory 64.

[0030] In this embodiment, hand dryer 1 further includes distance detection unit 70. Distance detection unit 70 detects the distance between nozzle 30 and washbasin 12. More specifically, as shown in FIG. 1, distance detection unit 70 detects distance L1 between nozzle 30 and the bottom surface of washbasin 12 in blowing direction D1 of air blown out from nozzle 30. Distance detection unit 70 can use, for example, an optical distance sensor as a sensor for detecting distance. In an optical distance sensor, light irradiated from a light source inside the distance sensor is reflected when it hits an object and is received by a light receiving element of the distance sensor. The distance is measured from the difference between the amount of light emitted by the light source and the amount of light received by the light receiving element.

[0031] In this embodiment, as shown in FIG. 3 , the distance detection unit 70 is provided closer to the tip than the center in the extension direction of the casing 20. The distance detection unit 70 is provided in a position in the casing 20 adjacent to the nozzle 30. For example, the distance detection unit 70 is housed in the tip space 28a of the casing 20, similar to the hand detection unit 50, and is disposed on the underside of the casing 20 between the nozzle 30 and the hand detection unit 50. The distance detection unit 70 does not need to accurately detect the distance between the nozzle 30 and the washbasin 12; it is sufficient if it can substantially detect the distance between the nozzle 30 and the washbasin 12. For example, since there is substantially no significant error, the distance between the portion of the casing 20 near the nozzle 30 and the washbasin 12 may be treated as the distance between the nozzle 30 and the washbasin 12. In this embodiment, as described above, the distance detection unit 70 is provided in a position adjacent to the nozzle 30 in the casing 20, and the distance between the distance detection unit 70 provided in a position adjacent to the nozzle 30 and the washbasin 12 is used as the distance between the nozzle 30 and the washbasin 12.

[0032] As shown in Fig. 7, the distance detection unit 70 is electrically connected to the control unit 60. The distance detection unit 70 outputs a signal indicating information about the detected distance and sends it to the control unit 60. The control unit 60 sets a mitigation wind speed based on the distance detected by the distance detection unit 70. In this embodiment, when the distance detected by the distance detection unit 70 is a first distance, the control unit 60 sets a predetermined first wind speed as the mitigation wind speed, and when the distance detected by the distance detection unit 70 is a second distance smaller than the first distance, the control unit 60 sets a second wind speed smaller than the first wind speed as the mitigation wind speed.

[0033] As a specific example of setting the mitigation air speed, the control unit 60 stores the table shown in Figure 8 in advance and sets the mitigation air speed based on this table. For example, if the distance L1 between the nozzle 30 and the bottom of the washbasin 12 detected by the distance detection unit 70 is 250 mm, the control unit 60 sets the air volume notch of the air blower 40 to "strong" and sets the mitigation air speed to "high speed." Also, if the distance L1 between the nozzle 30 and the bottom of the washbasin 12 detected by the distance detection unit 70 is 150 mm, the control unit 60 sets the air volume notch of the air blower 40 to "medium" and sets the mitigation air speed to "medium speed," which is lower than "high speed." 8 are set according to the distance L1 between the nozzle 30 and the bottom of the washbasin 12, and are set to a speed that does not scatter water droplets adhering to the inner surface of the washbasin 12 when the air blown out from the nozzle 30 hits the bottom of the washbasin 12. As an example of such a speed, the mitigation air speed is set to a speed that causes the speed of the air blown out from the nozzle 30 to hit the bottom of the washbasin 12 to be 20 m / s or less.

[0034] Furthermore, the control unit 60 does not set the mitigation air speed while the hand detection unit 50 detects the presence of a hand. This prevents the distance detection unit 70 from detecting the distance between the nozzle 30 and the user's hand, and the control unit 60 from setting the mitigation air speed based on this distance.

[0035] Next, the operation of the hand dryer 1 in this embodiment will be described with reference to Fig. 10. Fig. 10 is a flowchart of the operation control of the hand dryer 1.

[0036] Control of hand dryer 1 begins when power is turned on. First, in step ST1, distance detection unit 70 detects distance L1 between nozzle 30 and the bottom surface of washbasin 12, and outputs a signal including information indicating the detected distance to control unit 60. Next, control unit 60 receives the signal output from distance detection unit 70 and sets a mitigation air speed based on the distance detected by distance detection unit 70 (step ST2).

[0037] In step ST3, the hand detection unit 50 detects the presence or absence of a hand placed in the drying space 32 and outputs a hand detection signal indicating the detection result to the control unit 60. The control unit 60 determines whether or not a hand is present in the drying space 32 based on the hand detection signal output from the hand detection unit 50. If it is determined that a hand is present in the drying space 32, that is, if the hand detection unit 50 detects that a hand is present (step ST3, YES), the control unit 60 proceeds to step ST4. If it is determined that a hand is not present in the drying space 32, that is, if the hand detection unit 50 detects that a hand is not present (step ST3, NO), the process of step ST3 is repeated.

[0038] In step ST4, the control unit 60 operates the blower unit 40 so that the wind speed of the air blown out from the nozzle 30 becomes a preset wind speed for drying.

[0039] Next, in step ST5, the hand detection unit 50 detects the presence or absence of a hand placed in the drying space 32 and outputs a hand detection signal indicating the detection result to the control unit 60. The control unit 60 determines whether or not a hand is present in the drying space 32 based on the hand detection signal output from the hand detection unit 50. If it is determined that a hand is present in the drying space 32, that is, if the hand detection unit 50 detects that a hand is present (step ST5, YES), the process of step ST5 is repeated. If it is determined that a hand is not present in the drying space 32, that is, if the hand detection unit 50 detects that a hand is not present (step ST5, NO), the process proceeds to step ST6.

[0040] In step ST6, the control unit 60 starts a timer provided in the control unit 60. Next, the control unit 60 controls the operation of the blower unit 40 so that the wind speed of the air blown out from the nozzle 30 becomes the reduction wind speed set in step ST2 (step ST7).

[0041] Next, in step ST8, the control unit 60 determines whether the timer has reached a preset time. The preset time is set in consideration of ensuring that the high-speed airflow continues to be directed at the hands pulled out of the drying space 32 until the very end, thereby drying the entire hands. If it is determined that the preset time has passed (YES in step ST8), the process proceeds to step ST9. If it is determined that the preset time has not passed (NO in step ST8), the process of step ST8 is repeated.

[0042] In step ST9, the control unit 60 stops the operation of the blower unit 40. This completes the series of operations.

[0043] As described above, the hand dryer 1 of this embodiment comprises a nozzle 30 that blows air toward the drying space 32 where hands are placed, an air blowing unit 40 that sends out the air blown from the nozzle 30, a hand detection unit 50 that detects the presence or absence of hands placed in the drying space 32, and a control unit 60 that, when the hand detection unit 50 detects the presence of hands, controls the operation of the air blowing unit 40 so that the wind speed of the air blown from the nozzle 30 becomes a preset drying wind speed, and when the hand detection unit 50 detects the presence of hands but then detects their absence, controls the operation of the air blowing unit 40 so that the wind speed of the air blown from the nozzle 30 changes from the drying wind speed to a preset relaxation wind speed, and continues operating the air blowing unit 40 for a preset period of time, and then stops the operation of the air blowing unit 40.

[0044] Thus, when hand detection unit 50 detects the presence of a hand and then detects its absence, control unit 60 does not immediately stop operation of blower unit 40, but rather controls operation of blower unit 40 so that the wind speed of the air blown from nozzle 30 changes from the drying wind speed to the relaxation wind speed, and continues operation for a preset time. This ensures that the high-speed airflow continues to blow on the hand until it is removed from drying space 32, thereby drying the entire hand. Furthermore, because the wind speed of the air blown from nozzle 30 has changed from the drying wind speed to the relaxation wind speed, even if the airflow blown from nozzle 30 directly collides with the inner surface of washbasin 12 after the hand is removed from drying space 32 and before operation of blower unit 40 is stopped, the wind speed at the time of collision with washbasin 12 is suppressed. This suppresses the rebound of the airflow due to collision between the airflow blown from nozzle 30 and washbasin 12 and the scattering of water droplets adhering to the inner surface of washbasin 12, thereby reducing discomfort to the user.

[0045] The hand dryer 1 further includes a casing 20 provided with a nozzle 30 and positioned above the washbasin 12, and a distance detection unit 70 that detects the distance between the nozzle 30 and the washbasin 12. The relaxation air speed is set based on the distance detected by the distance detection unit 70. Setting the relaxation air speed based on the distance between the nozzle 30 and the washbasin 12 detected by the distance detection unit 70 prevents the relaxation air speed from being set too low, for example, when the distance between the nozzle 30 and the washbasin 12 is sufficient, making it difficult to dry the fingertips of the hands. This also prevents the air blown out from the nozzle 30 from colliding with the washbasin 12 after the hands are removed from the drying space 32, resulting in rebound of the airflow and scattering of water droplets adhering to the inner surface of the washbasin 12. This achieves an appropriate balance between hand drying performance and suppression of rebound of the airflow and scattering of water droplets after the hands are removed. In addition, the installer or contractor of the hand dryer 1 does not need to set the relaxation air speed according to the depth of the washbasin 12 of the washbasin 10 on which the hand dryer 1 is installed, making the installation of the hand dryer 1 easier.

[0046] When the distance detected by the distance detection unit 70 is a first distance, the control unit 60 sets a predetermined first wind speed as the mitigation wind speed. When the distance detected by the distance detection unit 70 is a second distance shorter than the first distance, the control unit 60 sets a second wind speed shorter than the first wind speed as the mitigation wind speed. With this configuration, the mitigation wind speed set when the distance detected by the distance detection unit 70 is the second distance shorter than the first distance is lower than the mitigation wind speed set when the distance detected by the distance detection unit 70 is the first distance. Generally, when the distance between the nozzle 30 and the washbasin 12 is large, the air blown out from the nozzle 30 attenuates before reaching the washbasin 12 and collides with the washbasin 12 at a speed slower than the blowing speed. Therefore, the rebound of the airflow due to collision with the washbasin 12 is small, and water droplets adhering to the inner surface of the washbasin 12 are less likely to be scattered. On the other hand, when the distance between the nozzle 30 and the washbasin 12 is small, the air blown out from the nozzle 30 strikes the washbasin 12 at a speed close to that of the blown air. This causes the airflow to rebound significantly upon impact with the washbasin 12, easily scattering water droplets adhering to the inner surface of the washbasin 12. Therefore, with the above-described configuration, the mitigation air speed is set to a low value when the distance detected by the distance detection unit 70 is small, and conversely, the mitigation air speed is set to a high value when the distance detected by the distance detection unit 70 is large. This reliably suppresses the rebound of the airflow and the scattering of water droplets after the hands are removed, while maintaining hand drying performance by not unnecessarily reducing the mitigation air speed. In this way, a more appropriate balance can be achieved between hand drying performance and the suppression of the rebound of the airflow and the scattering of water droplets after the hands are removed.

[0047] The casing 20 extends from the outside of the washbasin 12 toward above the washbasin 12, with the tip of the casing 20 located above the washbasin 12, and the distance detection unit 70 is located closer to the tip than the center in the extension direction of the casing 20. With this configuration, the distance detection unit 70 is provided in the casing 20 in which the nozzle 30 is provided and is positioned above the washbasin 12, so that the distance between the nozzle 30 and the washbasin 12 can be detected more reliably.

[0048] Distance detection unit 70 is provided in casing 20 at a position adjacent to nozzle 30. With this configuration, distance detection unit 70 can detect the distance between nozzle 30 and the point where the airflow blown out from nozzle 30 collides with the bottom surface of washbasin 12, and can detect the distance between nozzle 30 and washbasin 12 more accurately.

[0049] The mitigation air velocity is lower than the greatest air velocity of the air sent out from blower unit 40 and blown out from nozzle 30. By suppressing the mitigation air velocity in this way, it is possible to more reliably suppress the rebound of the air flow blown out from nozzle 30 after the hands are removed from drying space 32 due to collision between the air flow and washbasin 12, and the scattering of water droplets adhering to the inner surface of washbasin 12.

[0050] The relaxation air speed is lower than the drying air speed. By making the relaxation air speed lower than the drying air speed in this way, it is possible to more reliably prevent the air flow blown out from the nozzle 30 from colliding with the washbasin 12 after the hands are removed from the drying space 32, thereby more reliably preventing the air flow from bouncing back and the scattering of water droplets adhering to the inner surface of the washbasin 12.

[0051] Furthermore, a control method for hand dryer 1 according to this embodiment is a control method for hand dryer 1 having nozzle 30 that blows air toward drying space 32 where hands are placed, air blowing unit 40 that sends out the air blown out from nozzle 30, hand detection unit 50 that detects the presence or absence of hands placed in drying space 32, and control unit 60 that controls the operation of air blowing unit 40 based on the detection result of hand detection unit 50, in which, when hand detection unit 50 detects the presence of hands, control unit 60 controls the wind speed of air blown out from nozzle 30 to be a preset wind speed for drying. the control unit 60 controls the operation of the blower 40 when the hand detection unit 50 detects the presence of a hand and then detects the absence of a hand, so that the wind speed of the air blown out from the nozzle 30 changes from the drying wind speed to a preset relaxation wind speed; the control unit 60 continues the operation of the blower 40 blowing air out from the nozzle 30 at the relaxation wind speed for a preset time; and the control unit 60 stops the operation of the blower 40 that has been continued for the preset time.

[0052] Thus, when hand detection unit 50 detects the presence of a hand and then detects its absence, control unit 60 does not immediately stop operation of blower unit 40, but rather controls operation of blower unit 40 so that the wind speed of the air blown from nozzle 30 changes from the drying wind speed to the relaxation wind speed, and continues operation for a preset time. This ensures that the high-speed airflow continues to hit the hand as it is removed from drying space 32, completely drying the hand. Furthermore, because the wind speed of the air blown from nozzle 30 has changed from the drying wind speed to the relaxation wind speed, even if the airflow blown from nozzle 30 directly collides with the inner surface of washbasin 12 after the hand is removed from drying space 32 and before operation of blower unit 40 is stopped, the wind speed at the time of collision with washbasin 12 is suppressed. This suppresses the rebound of the airflow due to collision between the airflow blown from nozzle 30 and washbasin 12 and the scattering of water droplets adhering to the inner surface of washbasin 12, thereby reducing discomfort to the user.

[0053] In the present embodiment described above, the hand detection unit 50 is provided in the casing 20 near the nozzle 30 and is positioned closer to the user than the nozzle 30. Also, as shown in FIG. 2 , the casing 20 is positioned parallel to the water discharge unit 18 on the washbasin 10. Therefore, when a user places their hand below the water discharge unit 18 to wash their hands, their hand may enter a portion of the lower part of the casing 20 near the water discharge unit 18, causing the hand detection unit 50 to detect the hand and high-speed air to be blown out from the nozzle 30. In this case, water from the water discharge unit 18 and high-speed air from the nozzle 30 may be simultaneously discharged, potentially causing the water discharged from the water discharge unit 18 to be scattered by the high-speed air. Therefore, it is preferable that the hand detection unit 50 be positioned away from the water discharge unit 18 on the casing 20. This configuration reduces the possibility that the user's hand will enter the detection range of the hand detection unit 50 when the user places their hand below the water discharge unit 18, thereby preventing water and high-speed air from being simultaneously discharged.

[0054] Furthermore, the nozzle 30 is formed as an elongated slit extending linearly in the extension direction of the casing 20. When the nozzle 30 has an elongated slit shape, the potential core of the airflow blown out from the nozzle 30 becomes smaller, and the wind speed of the airflow tends to attenuate as it moves away from the nozzle 30. Therefore, while ensuring sufficient wind speed at the position of the user's hands to blow away water droplets on the hands, the wind speed when the airflow collides with the washbasin 12 after the user finishes drying their hands and removes their hands from the drying space 32 can be suppressed. This makes it difficult for water droplets adhering to the inner surface of the washbasin 12 to scatter around, resulting in more hygienic use. Furthermore, by making the slit width of the nozzle 30 2 mm or less, the wind speed attenuation effect can be more easily achieved.

[0055] Distance detection unit 70 detects the distance between nozzle 30 and washbasin 12. Depending on the type of sensor used in distance detection unit 70, such as an optical distance sensor, distance detection unit 70 can detect the distance between nozzle 30 and the surface of the water stored in washbasin 12 when drain outlet 14 is closed and water is stored in washbasin 12. In this case, the mitigation air speed is set based on the distance between nozzle 30 and the surface of the water stored in washbasin 12 detected by distance detection unit 70, thereby reducing the splashing of water stored in washbasin 12 caused by collision between the airflow blown out from nozzle 30 and the surface of the water stored in washbasin 12.

[0056] In the above-described embodiment, the distance detection unit 70 is provided in the casing 20, but this is not limited to this. The distance detection unit 70 may be provided separately from the casing 20 as long as it can detect the distance between the nozzle 30 and the washbasin 12.

[0057] Although three wind speed levels are set as the mitigation wind speed, this is not limited thereto. The mitigation wind speed may be set to one or two wind speed levels, or to four or more wind speed levels. Furthermore, although the mitigation wind speed is set in stages according to the distance between the nozzle 30 and the washbasin 12, this is not limited thereto, and the mitigation wind speed may be set to change continuously according to the distance between the nozzle 30 and the washbasin 12.

[0058] Although the mitigation air speed is set based on the distance detected by the distance detection unit 70 in the above embodiment, this is not limiting. The hand dryer 1 may further include an air speed setting unit that allows the user to externally set the mitigation air speed. For example, the air volume switch 43b provided on the surface of the box 42 may function as the air speed setting unit, allowing the user to set the mitigation air speed by operating the air volume switch 43b. As a specific example, the air volume switch 43b may be configured as a tactile switch, and the state of the air volume notch set by the tactile switch (either "strong," "medium," or "weak") may be displayed by an LED or the like. When the tactile switch is pressed and held for five seconds or more while the air volume notch is set, the air speed corresponding to the air volume notch is set as the mitigation air speed. With this configuration, even if the hand dryer 1 does not have a distance detection unit 70, the relaxation air speed can be set with a simple configuration, and the rebound of the air flow caused by the collision of the air flow blown out from the nozzle 30 with the washbasin 12 after the hands are pulled out of the drying space 32 and the scattering of water droplets adhering to the inner surface of the washbasin 12 can be suppressed.

[0059] In the operation control of the hand dryer 1, first, in step ST1, the distance detection unit 70 detects the distance between the nozzle 30 and the washbasin 12. Then, in step ST2, the control unit 60 sets the mitigation air speed based on the distance detected by the distance detection unit 70. In other words, once the mitigation air speed is set, it is not changed, but this is not limited to this. The setting of the mitigation air speed may be reviewed after a certain period of time has passed. For example, if the hand detection unit 50 detects that no hands are present in step ST3 (NO in step ST3), the process may return to step ST1 after a certain period of time has passed, and the distance detection unit 70 may detect the distance and set the mitigation air speed based on the detected distance (step ST2). This allows the mitigation air speed to be reset in response to changes in the distance, such as when water is collected in the washbasin 12.

[0060] It should be noted that appropriate modifications or omissions of the above-described embodiments are also included within the scope of the technical ideas shown in the embodiments. [Industrial Applicability]

[0061] According to the present disclosure, a hand dryer can be provided that can suppress the rebound of airflow and the scattering of water droplets after hands are pulled out of a drying space, thereby reducing discomfort to the user. [Explanation of symbols]

[0062] 1 hand dryer, 10 sink, 11 wall, 12 washbasin, 14 drain, 16 drain pipe, 18 water discharge section, 20 casing, 22 outer cylinder section, 24 inner cylinder section, 24a recess, 26 air duct, 28a tip space, 28b, 28c air duct outer space, 30 nozzle, 32 drying space, 40 air blower section, 42 box body, 43a power switch, 43b air volume switch, 43c heater switch, 44 air blower duct, 50 hand detection section, 60 control section, 62 processor, 64 memory, 70 distance detection section, D1 blowing direction, FL floor, L1 distance, WL wall.

Claims

1. a nozzle that blows air toward a drying space where hands are placed; A washbasin to receive water, a blower that blows out air from the nozzle; a hand detection unit that detects the presence or absence of a hand placed in the drying space; a control unit that, when the hand detection unit detects the presence of a hand, controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle becomes a preset drying wind speed, and, when the hand detection unit detects the absence of a hand after detecting the presence of a hand, controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle becomes a preset relaxation wind speed from the drying wind speed, and continues the operation of the blower unit for a preset time, and then stops the operation of the blower unit; A hand dryer comprising:

2. a casing provided with the nozzle and arranged above the washbasin; a distance detection unit that detects the distance between the nozzle and the washbasin; Furthermore, The hand dryer according to claim 1 , wherein the relaxation air speed is set based on the distance detected by the distance detection unit.

3. The hand dryer of claim 2, wherein the control unit sets a predetermined first wind speed as the mitigation wind speed when the distance detected by the distance detection unit is a first distance, and sets a second wind speed smaller than the first wind speed as the mitigation wind speed when the distance detected by the distance detection unit is a second distance smaller than the first distance.

4. The casing extends from the outside of the washbasin toward above the washbasin, and a tip of the casing is located above the washbasin, The hand dryer according to claim 2 or 3, wherein the distance detection unit is provided closer to the tip end than to the center in the extension direction of the casing.

5. The hand dryer according to claim 2 or 3, wherein the distance detection unit is provided at a position adjacent to the nozzle on the casing.

6. The hand dryer according to claim 1, further comprising an air speed setting means that enables a user to set the relaxation air speed from outside.

7. The hand dryer according to claim 1 or 2, wherein the relaxation air velocity is lower than the maximum air velocity of the air sent out from the blower and blown out from the nozzle.

8. The hand dryer according to claim 1 or 2, wherein the air velocity for relaxation is lower than the air velocity for drying.

9. A method for controlling a hand dryer having a nozzle that blows air toward a drying space where hands are placed, a washbasin that receives water, an air blower that sends out the air blown out from the nozzle, a hand detection unit that detects the presence or absence of hands placed in the drying space, and a control unit that controls the operation of the air blower based on the detection result of the hand detection unit, When the hand detection unit detects the presence of a hand, the control unit controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle becomes a preset drying wind speed; When the hand detection unit detects the presence of a hand and then detects the absence of a hand, the control unit controls the operation of the blower unit so that the wind speed of the air blown out from the nozzle changes from the drying wind speed to a predetermined relaxation wind speed; a step in which the control unit continues operation of the blower unit to blow air from the nozzle at the relief wind speed for a preset time; a step of the control unit stopping the operation of the blower unit that has continued for the preset time; A method for controlling a hand dryer comprising:

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