JP7707566B2 - hand dryer - Google Patents

Description

Aspects of the present invention generally relate to hand dryers.

There are hand dryers that are attached to the walls of toilets and washrooms and are used to dry the hands of users after washing their hands. These hand dryers operate an electric blower in response to the detection of the user's hands, blowing air onto the user's hands to dry them.

Hand dryers can shorten the time it takes to dry hands by increasing the air volume and temperature. In such cases, it is necessary to increase the output of the electric blower or the heater that raises the air temperature, but this increases the amount of heat generated by the control unit (switching element) of the electric blower or heater. This amount of heat generated by the control unit becomes more noticeable when the hand dryer is used multiple times in a short period of time.

The hand dryer described in Patent Document 1 dissipates heat from the control unit that controls the electric blower by contacting a heat dissipating material with the control unit, and placing the other end of the heat dissipating material in a circulating air passage that connects the electric blower and the nozzle.

Japanese Patent Application Publication No. 11-290240

For example, if the hand dryer described in Patent Document 1 is used multiple times in a short period of time, it may generate heat before the control unit can dissipate heat, and there is a risk that the control unit will not dissipate heat efficiently.

The present invention was developed based on the recognition of this problem, and aims to provide a hand dryer that can efficiently dissipate heat from the control unit.

The first invention is a hand dryer comprising a drying chamber for drying hands inserted therein, a hand detection sensor for detecting hands inserted in the drying chamber, a first AC load unit that is activated by detection by the hand detection sensor, a first control unit and a second control unit that control the flow of electricity to the first AC load unit, a central processing unit that controls the operation of the first control unit and the second control unit, a first heat dissipation unit that dissipates heat from the first control unit by contacting the first control unit, and a second heat dissipation unit that dissipates heat from the second control unit by contacting the second control unit, and the central processing unit selects the operation of the first control unit or the operation of the second control unit based on operation information from the hand detection sensor.

According to this hand dryer, the operation of the first control unit that supplies electricity to the first AC load unit and the operation of the second control unit are selected, so that when one control unit is operating, the other control unit can efficiently dissipate heat. Therefore, even if the hand dryer is used continuously, for example, the first control unit and the second control unit can be prevented from becoming too hot, and the lifespan of the first control unit and the second control unit can be improved. In addition, the first heat dissipation unit and the second heat dissipation unit can efficiently dissipate heat from the first control unit and the second control unit without using an air-cooling device such as a fan or a water-cooling device, so that the hand dryer can be prevented from becoming large and power consumption can be reduced.

The second invention is a hand dryer according to the first invention, characterized in that the first AC load unit is an electric blower that blows air toward the drying chamber.

This hand dryer can prevent the first and second control units from becoming too hot, even if the output of the electric blower, which is always activated when drying the hands, is increased.

The third invention is a hand dryer according to the first or second invention, characterized in that the operation information is the number of times the hand detection sensor detects a hand.

With this hand dryer, switching between the operation of the first control unit and the operation of the second control unit is performed based on the number of detections, so the first control unit and the second control unit can be operated alternately with simple control processing.

The fourth invention is a hand dryer according to any one of the first to third inventions, characterized in that the first heat dissipation section and the second heat dissipation section are formed continuously.

With this hand dryer, the heat dissipation material can be shared, which can reduce the number of fixing parts for fixing the heat dissipation material, for example, making it possible to make the hand dryer more compact and reduce costs.

The fifth invention is a hand dryer according to the fourth invention, further comprising a second AC load unit that is activated by detection by the hand detection sensor, another control unit that is connected to the central processing unit and controls the second AC load unit, and a third heat dissipation unit that dissipates heat from the other control unit by contacting the other control unit, and the third heat dissipation unit is formed continuously with the first heat dissipation unit and the second heat dissipation unit.

With this hand dryer, the heat dissipation section can be shared, which can reduce the number of fixing parts for fixing the heat dissipation section, for example, making it possible to make the hand dryer more compact and reduce costs.

The sixth invention is a hand dryer according to the fifth invention, characterized in that the first control unit, the second control unit, and the other control unit are arranged in parallel such that either the first control unit or the second control unit is located in the center, and the distance between the other control unit and the one control unit is greater than the distance between the first control unit and the second control unit.

With this hand dryer, even if the heat dissipation unit is shared, it is possible to prevent the heat dissipated from other control units from being transferred to the first and second control units. In other words, the first and second control units can reduce the impact of the fanning heat of the other control units.

The seventh invention is a hand dryer according to the fifth or sixth invention, further comprising a room temperature sensor that detects room temperature, the second AC load unit being a heater that heats the air blown toward the drying chamber, and the central processing unit activating the other control units when the room temperature detected by the room temperature sensor is equal to or lower than a room temperature threshold value.

With this hand dryer, when the temperature of each control unit is above the room temperature threshold, the heater is not operated, so even if the heat dissipation unit is shared, the heat dissipated from other control units is prevented from being transferred to the first and second control units. In addition, when the temperature is above the room temperature threshold, air of a temperature sufficient to dry the hands is blown out even without operating the heater, which allows for power saving.

The eighth invention is a hand dryer according to any one of the fifth to seventh inventions, further comprising a room temperature sensor for detecting room temperature, a memory unit for storing operation history information of the first control unit, the second control unit, and the other control units, and the central processing unit calculates the temperature of each control unit based on the room temperature and the operation history information of each control unit, and prohibits operation of at least a control unit whose temperature is equal to or higher than a temperature threshold.

This hand dryer can prevent the first, second and other control units from reaching high temperatures that would prevent them from functioning properly. This can therefore improve the lifespan of the first, second and other control units.

According to this aspect of the present invention, a hand dryer is provided that can efficiently dissipate heat from the control unit.

1 is a perspective view showing a hand dryer according to an embodiment of the present invention; 2 is a block diagram showing an electrical system and an airflow path system of the hand dryer. FIG. 4 is a front view showing the positional relationship between a first control unit, a second control unit, and other control units. FIG. 6 is a graph simply showing temperature transitions in a first control unit and a second control unit. 4 is a flowchart showing an example of a control process performed by a central processing unit of the hand drying device. 10 is a graph simply showing a transition in temperature of a control unit. FIG. 4 is a block diagram showing an electrical system of a hand dryer according to a first modified example of the present invention. FIG. 11 is a block diagram showing an electrical system of a hand dryer according to a second modified example of the present invention. FIG. 11 is a block diagram showing an electrical system of a hand dryer according to a third modified example of the present invention.

The present embodiment will be described below with reference to the drawings. Note that in each drawing, similar components are given the same reference numerals and detailed descriptions are omitted as appropriate.

FIG. 1 is a perspective view showing a hand dryer according to an embodiment of the present invention.
As shown in Fig. 1, hand dryer 10 includes a main body 12. Main body 12 has a concave drying chamber 14 into which a user's hands can be inserted. Hand dryer 10 is attached to, for example, a wall surface of a toilet room when in use. Hand dryer 10 detects hands inserted into drying chamber 14, and blows air onto the hands inside drying chamber 14. In this way, hand dryer 10 dries hands that are wet, for example, after washing their hands after using the toilet.

The drying chamber 14 opens, for example, upward, and dries the hands inserted therein. The main body 12 is, for example, in the shape of an open box that opens upward. Therefore, the user can dry their hands by inserting their hands into the drying chamber 14 from top to bottom. The opening direction of the drying chamber 14 is not limited to the upward direction, but may be, for example, forward or diagonally upward toward the front. The opening direction of the drying chamber 14 may be any direction that makes it easy for the user to insert their hands.

The opening of the drying chamber 14 is long horizontally. The horizontal length of the opening of the drying chamber 14 is longer than the front-to-rear length of the opening of the drying chamber 14. This allows the hand dryer 10 to insert the left and right hands into the drying chamber 14 from above with the hands lined up horizontally. In other words, the user can simply insert both hands into the drying chamber 14 with both hands hanging down, allowing the hands to be dried in a natural posture.

The main body 12 has a front surface 12a, a rear surface 12b, and a pair of side surfaces 12c, 12d. In this example, the main body 12 is a substantially rectangular box. The drying chamber 14 is, for example, a substantially rectangular recess surrounded at the front, rear, and both sides by the front surface 12a, the rear surface 12b, and the side surfaces 12c, 12d.

The drying chamber 14 has an inner surface on the front side formed by the front portion 12a, an inner surface on the back side formed by the back portion 12b, and a bottom surface that is continuous with the lower ends of each inner surface. In addition, both side ends of each inner surface and bottom surface are closed by each of the side portions 12c and 12d. Each surface of the drying chamber 14 receives water droplets blown off wet hands.

The shapes of the main body 12 and the drying chamber 14 are not limited to this, and may be any shape that allows hands to be inserted. For example, the side portions 12c, 12d may be omitted. That is, the drying chamber 14 may be in the shape of a groove that is open at the top and sides. In this way, the shape of the drying chamber 14 may be such that a part of it is open other than the opening for inserting hands.

The main body 12 has a number of air outlets 15 for blowing air into the drying chamber 14. Each air outlet 15 is, for example, a substantially circular opening. Each air outlet 15 is provided on the inner surface on the front side of the front portion 12a and on the inner surface on the rear side of the rear portion 12b. Each air outlet 15 is, for example, arranged in a substantially straight line in the lateral direction (horizontal direction) on each inner surface.

Each air outlet 15 is provided, for example, near the upper end (opening end) of each inner surface, and blows air diagonally downward. That is, each air outlet 15 blows water droplets toward the bottom side of the drying chamber 14. This prevents the blown water droplets from splashing on the user.

The shape of the air outlet 15 may be any shape. The number of air outlets 15 may be any number. For example, one air outlet in the shape of a slit extending laterally may be provided in the main body 12. The air outlets may be any shape and number that can appropriately blow air onto the hands inserted in the drying chamber 14.

The main body 12 has a pair of ventilation holes 18 provided, for example, on each of the side portions 12c, 12d. Each ventilation hole 18 allows the air blown out from each air outlet 15 to escape to the outside of the drying chamber 14. This makes it possible to prevent, for example, air containing water droplets from being turned back inside the drying chamber 14 and heading toward the user. In other words, it is possible to prevent the blown-off water droplets from heading toward the user.

The hand drying device 10 further includes a water receiving tray 20. The water receiving tray 20 is detachably attached, for example, to the bottom of the main body 12. The main body 12 has drainage grooves (not shown), and sends water droplets received on each surface of the drying chamber 14 to the water receiving tray 20 via the drainage grooves. In this way, the water receiving tray 20 collects water droplets blown away within the drying chamber 14.

FIG. 2 is a block diagram showing an electrical system and an airflow path system of the hand dryer.
As shown in FIG. 2, the hand dryer 10 includes a hand detection sensor 22, a room temperature sensor 24, an electric blower 26, a heater 30, a control unit 32, other control sections 34, a heat sink 36, and a central processing section 38.

The hand detection sensor 22 detects a hand inserted into the drying chamber 14. The hand detection sensor 22 is connected to the central processing unit 38. The hand detection sensor 22 transmits the hand detection result to the central processing unit 38. For example, a transmissive optical sensor (photointerrupter) is used as the hand detection sensor 22. The hand detection sensor 22 is not limited to this, and may be any sensor that can detect the user's hand. The hand detection sensor 22 may be, for example, a reflective optical sensor, a distance sensor, a pyroelectric sensor, a capacitance sensor, an ultrasonic sensor, or a microwave sensor.

The room temperature sensor 24 detects the temperature in the room in which the hand dryer 10 is installed. The room temperature sensor 24 detects the room temperature, for example, in a toilet room. The room temperature sensor 24 is provided, for example, inside the main body 12, and measures the temperature in a pipe (not shown) through which the outside air drawn in by the operation of the electric blower 26 flows.

The room temperature sensor 24 is connected to the central processing unit 38 and transmits the detected room temperature to the central processing unit 38. The room temperature sensor 24 is provided so that the central processing unit 38 can determine whether or not to operate the heater 30. The room temperature sensor 24 is also provided so that the central processing unit 38 can calculate the temperature Tj of the first and second control units 32a, 32b and the other control units 34. The room temperature sensor 24 is provided as necessary and can be omitted.

The electric blower 26 is activated by the detection of the hand detection sensor 22. The electric blower 26 (fan motor) is connected to an air passage 28. The air passage 28 is provided with each outlet 15 at the downstream end in the air flow direction. The electric blower 26 draws in air from, for example, a room in which the hand dryer 10 is installed and supplies the air to the air passage 28, thereby blowing air from each outlet 15 toward the drying chamber 14. In this embodiment, the electric blower 26 constitutes the first AC load section of the present invention. The electric blower 26 is connected to a central processing section 38 via a control unit 32.

The heater 30 is activated by detection by the hand detection sensor 22. The heater 30 is provided on the path of the air passage 28 between the electric blower 26 and each air outlet 15. The heater 30 heats the gas (wind) flowing from the electric blower 26 toward each air outlet 15, thereby warming the gas blown out from each air outlet 15. This allows the hand dryer 10 to blow out warm air heated by the heater 30 from each air outlet 15. This makes it possible to improve the drying performance of the user's hands, for example. For example, the user's hands can be dried in a shorter time than when unheated air is blown out.

The heater 30 is connected to the central processing unit 38 via another control unit 34. In this embodiment, the heater 30 constitutes the second AC load unit of the present invention. The heater 30 is provided as necessary and can be omitted. The hand dryer 10 may blow unheated air supplied from the electric blower 26 from each air outlet 15. For example, a fin heater is used as the heater 30. The heater 30 may be any heater capable of heating the gas flowing from the electric blower 26 toward each air outlet 15.

The control unit 32 is connected to the central processing unit 38 and the electric blower 26. The control unit 32 controls the power supply to the electric blower 26 (first AC load unit) by a command signal from the central processing unit 38. The control unit 32 has multiple control units. In this embodiment, the control unit 32 has two control units, a first control unit 32a and a second control unit 32b. The first control unit 32a and the second control unit 32b are switching elements that, for example, supply or cut off power from a power source (not shown) to the electric blower 26. The first control unit 32a and the second control unit 32b are energized in an operating state (ON state) and cut off (not energized) in an inoperating state (OFF state). The switching elements may be of a contact type or a non-contact type.

The first control unit 32a and the second control unit 32b are connected in parallel to the central processing unit 38 and the electric blower 26. As a result, the electric blower 26 is supplied with power from the central processing unit 38 via either the first control unit 32a or the second control unit 32b. That is, when the first control unit 32a is in an operating state (ON), the second control unit 32b is in an inoperating state (OFF). On the other hand, when the second control unit 32b is in an operating state (ON), the first control unit 32a is in an inoperating state (OFF). The central processing unit 38 determines which of the first control unit 32a and the second control unit 32b is selected to operate. The selection control of the operation of the first control unit 32a and the second control unit 32b executed by the central processing unit 38 will be described later.

The other control unit 34 is connected to the central processing unit 38 and the heater 30. The other control unit 34 controls the supply of electricity to the heater 30 (second AC load unit) in response to a command signal from the central processing unit 38. The other control unit 34 is, for example, a switching element that supplies or cuts off power to the heater 30 from a power source (not shown). The other control unit 34 is energized in an activated state (ON state) and is cut off (not energized) in a deactivated state (OFF state). This switching element may be of either a contact type or a contactless type.

The heat dissipation material 36 is a heat sink made of a metal material (e.g., aluminum) with high heat transfer properties. The heat dissipation material 36 is in contact with the first control unit 32a, the second control unit 32b, and the other control units 34, respectively. As a result, the heat dissipation material 36 dissipates heat from the first control unit 32a, the second control unit 32b, and the other control units 34 that are activated. The heat dissipation material 36 has a first heat dissipation section 36a in contact with the first control unit 32a, a second heat dissipation section 36b in contact with the second control unit 32b, and a third heat dissipation section 36c in contact with the other control units 34.

In this embodiment, the heat dissipation material 36 is formed by continuously forming the first heat dissipation section 36a, the second heat dissipation section 36b, and the third heat dissipation section 36c. In other words, the first control section 32a, the second control section 32b, and the other control section 34 are arranged in contact with one heat dissipation material 36. This allows the hand dryer 10 to be made smaller and the costs to be reduced. In addition, the surface area of the heat dissipation material 36 can be increased, allowing each of the control sections 32a, 32b, and 34 to dissipate heat efficiently.

FIG. 3 is a front view showing the positional relationship between the first control unit, the second control unit and other control units.
3, the first control unit 32a, the second control unit 32b, and the other control units 34 are arranged in parallel, for example, in the left-right direction. Note that the first control unit 32a, the second control unit 32b, and the other control units 34 may be arranged in parallel in the up-down direction or in the diagonal direction.

The first control unit 32a, the second control unit 32b, and the other control unit 34 are arranged such that either the first control unit 32a or the second control unit 32b is located in the center. In this embodiment, the second control unit 32b is located in the center. In other words, the second control unit 32b is sandwiched between the first control unit 32a and the other control unit 34. The first control unit 32a may be located in the center. Also, FIG. 3 shows a case where the first control unit 32a and the second control unit 32b are arranged on the right side, but the first control unit 32a and the second control unit 32b may be arranged on the left side. In other words, either the first control unit 32a or the second control unit 32b may be located in the center, and the other control unit may be arranged around one of the control units.

Here, either the first control unit 32a or the second control unit 32b is selected and activated when a hand is detected by the hand detection sensor 22. On the other hand, the other control unit 34 is activated when a hand is detected by the hand detection sensor 22, and so there is a risk that it will generate more heat than the first control unit 32a or the second control unit 32b.

As shown in FIG. 3, the distance L1 between the other control unit 34 and one of the control units (e.g., the second control unit 32b) located in the center of the control unit 32 is larger than the distance L2 between the first control unit 32a and the second control unit 32b. This makes it possible to prevent heat radiated from the other control unit 34 from being transferred to the second control unit 32b even if the heat dissipation material 36 is shared. In other words, the first control unit 32a and the second control unit 32b can reduce the influence of the fanned heat of the other control unit 34.

The central processing unit 38 is connected to the hand detection sensor 22, the room temperature sensor 24, the control unit 32, and the other control units 34. The central processing unit 38 controls the operation of the first control unit 32a and the second control unit 32b of the control unit 32 based on the detection of the hand detection sensor 22. The central processing unit 38 also controls the operation of the other control units 34 based on the detection of the hand detection sensor 22. That is, the central processing unit 38 controls the operation of the electric blower 26 and the heater 30 based on the detection of the hand detection sensor 22.

The central processing unit 38 selects between the operation of the first control unit 32a and the operation of the second control unit 32b based on the operation information of the hand detection sensor 22. For example, the operation information is the number of times the hand detection sensor 22 detects a hand. This number of detections may be one or multiple times (two or more). The number of detections (threshold) based on this switching is stored in advance in the memory unit 39 of the central processing unit 38. The memory unit 39 may be provided separately from the central processing unit 38. For example, when the number of detections is set to one time, the central processing unit 38 alternately selects between the operation of the first control unit 32a and the operation of the second control unit 32b.

FIG. 4 is a graph simply showing the temperature transitions of the first control unit and the second control unit.
A solid line 321 shown in FIG. 4 indicates the temperature transition of the first control unit 32a, and a dashed line 322 shown in FIG. 4 indicates the temperature transition of the second control unit 32b.

When a hand is detected by the hand detection sensor 22 at time t1, the first control unit 32a is activated (ON). This causes power to be supplied to the electric blower 26 via the first control unit 32a, and the electric blower 26 operates. The first control unit 32a causes the temperature to gradually increase from T0 to T1 while the electric blower 26 is operating.

When the hand detection sensor 22 detects no hand at time t2, the first control unit 32a is deactivated (OFF), and the operation of the electric blower 26 stops. After that, the first control unit 32a gradually decreases the temperature from T1 to T0 due to the heat dissipation material 36 (heat dissipation unit 36a).

At time t3, the hand of the person who will next use the hand dryer 10 is detected by the hand detection sensor 22. In this case, the central processing unit 38 selects and activates (ON) the second control unit 32b. This causes power to be supplied to the electric blower 26 via the second control unit 32b, and the electric blower 26 operates. The second control unit 32b causes the temperature to gradually increase from T0 to T2 while the electric blower 26 is operating.

When the hand detection sensor 22 detects no hand at time t4, the second control unit 32b is deactivated (OFF), and the operation of the electric blower 26 stops. After that, the second control unit 32b gradually decreases the temperature from T2 to T0 due to the heat dissipation material 36 (heat dissipation unit 36b).

Between time t3 and time t4, even if the electric blower 26 is operating, the first control unit 32a is not operating. This allows the first control unit 32a to dissipate heat efficiently even if the hand dryer 10 is used continuously.

Then, at time t5, the hand of the next person to use the hand dryer 10 is detected by the hand detection sensor 22. In this case, the central processing unit 38 operates the electric blower 26 by selecting and activating (ON) the first control unit 32a. In this way, when operating the electric blower 26, the first control unit 32a and the second control unit 32b are alternately operated, so that the first control unit 32a and the second control unit 32b can efficiently dissipate heat.

The central processing unit 38 also obtains the room temperature Ta of the location where the hand dryer 10 is installed from the room temperature sensor 24. Then, when the room temperature Ta detected by the room temperature sensor 24 is equal to or lower than the room temperature threshold value Tb (Ta≦Tb), the central processing unit 38 activates the other control units 34. The room temperature threshold value Tb is pre-stored in the memory unit 39 and is set to, for example, 30° C. The room temperature threshold value Tb is, for example, a temperature suitable for drying hands, and is set by experiment and simulation.

In other words, when the room temperature Ta is high (e.g., higher than 30°C), the temperature of the air blown out from the air outlet 15 is also 30°C or higher, so there is no need to operate the heater 30. This allows for power savings. On the other hand, when the room temperature Ta is low (e.g., below 30°C), the heater 30 is operated to increase the temperature of the air blown out from the air outlet 15, allowing the hands to be dried efficiently.

The central processing unit 38 also calculates the temperature Tj of each of the control units 32a, 32b, and 34 from the operation history information of the first control unit 32a, the second control unit 32b, and the other control units 34 and the room temperature Ta. In this way, the central processing unit 38 monitors the temperature Tj of each of the first control unit 32a, the second control unit 32b, and the other control units 34.

When the temperature Tj of each control unit 32a, 32b, 34 becomes equal to or higher than the temperature threshold value Tjmax, the central processing unit 38 prohibits the operation of at least that control unit. This makes it possible to prevent the first control unit 32a, the second control unit 32b, and the other control units 34 from becoming too hot, thereby improving the lifespan of each control unit 32a, 32b, 34. The calculation formula for temperature Tj and the temperature threshold value Tjmax are stored in advance in the memory unit 39. The calculation of temperature Tj performed by the central processing unit 38 will be described later.

The hand dryer 10 according to this embodiment has the configuration described above. Next, we will explain the control process performed by the central processing unit 38.

FIG. 5 is a flowchart showing an example of a control process performed by the central processing unit of the hand dryer.
The control process shown in Fig. 5 is pre-stored in storage unit 39. The control process shown in Fig. 5 is repeatedly executed at a predetermined cycle after hand dryer 10 is powered on. In Fig. 5, each step is indicated by "S", and for example, "step 1" is indicated by "S1".

In S1, it is determined whether a hand has been detected. That is, the central processing unit 38 determines whether the hand detection sensor 22 has detected a hand. If S1 is "YES", that is, if a hand has been detected, the process proceeds to S2. On the other hand, if S1 is "NO", that is, if a hand has not been detected, the process ends and the detection of a hand is monitored.

In S2, the room temperature Ta and operation history information of each of the control units 32a, 32b, 34 are acquired. The operation history information is, for example, the number of times each of the control units 32a, 32b, 34 has been in the ON state or OFF state and the operation time after the power is turned on. Note that S2 may be executed before S1. The central processing unit 38 then calculates the temperature Tj of each of the control units 32a, 32b, 34 from the room temperature Ta and the operation history information of each of the control units 32a, 32b, 34. The calculation of the temperature Tj will be explained later.

In S3, it is determined whether the operation of the first control unit 32a or the second control unit 32b is prohibited. In other words, the central processing unit 38 determines whether the temperature Tj of the first control unit 32a or the temperature Tj of the second control unit 32b calculated in S2 is equal to or higher than the temperature threshold value Tjmax.

If S3 returns "YES", i.e., the operation of the first control unit 32a or the second control unit 32b is prohibited, the process ends. This prevents the first control unit 32a or the second control unit 32b from becoming too hot and shortening their lifespan. On the other hand, if S3 returns "NO", i.e., the operation of the first control unit 32a or the second control unit 32b is not prohibited, the process proceeds to S4.

In S4, it is determined whether or not the operation of the other control units 34 is prohibited. That is, the central processing unit 38 determines whether or not the temperature Tj of the other control units 34 calculated in S2 is equal to or higher than the temperature threshold value Tjmax. The temperature threshold value Tjmax of each control unit 32a, 32b, 34 may be the same value or may be a different value. The temperature threshold value Tjmax of each control unit 32a, 32b, 34 is appropriately set as a value that allows each control unit 32a, 32b, 34 to operate satisfactorily.

If S4 returns "YES", i.e., if the operation of the other control unit 34 is prohibited, the process proceeds to S7. On the other hand, if S4 returns "NO", i.e., if the operation of the other control unit 34 is not prohibited, the process proceeds to S5.

In S5, it is determined whether the room temperature Ta is equal to or lower than the room temperature threshold value Tb (Ta≦Tb). That is, the central processing unit 38 determines whether the room temperature Ta of the room temperature sensor 24 acquired in S2 is equal to or lower than the room temperature threshold value Tb (e.g., 30° C.).

If S5 is "YES", that is, if the room temperature Ta is equal to or lower than the room temperature threshold value Tb, proceed to S6. On the other hand, if S5 is "NO", that is, if the room temperature Ta is higher than the room temperature threshold value Tb, proceed to S7.

In S6, the other control unit 34 is activated (ON). This causes power to be supplied from the other control unit 34 to the heater 30, and operation of the heater 30 begins. In this way, when the temperature is so high that malfunctions may occur in the operation of the other control unit 34 ("YES" in S4), the heater 30 is not activated. This makes it possible to improve the life of the other control unit 34. Also, when the room temperature Ta is high ("NO" in S5), the heater 30 is not activated. This makes it possible to save power.

In the next step S7, it is determined whether the number of hand detections is an odd number. That is, the central processing unit 38 determines whether the number of hand detections made by the hand detection sensor 22 after power-on is an odd number or an even number. Note that the number of hand detections does not have to be reset after power-on, and the number of times before power-on may be continuously counted. Also, if "YES" was previously determined in S3, the first control unit 32a and the second control unit 32b are not operating, so the hand detection at that time does not have to be counted.

If S7 returns "YES", i.e., the number of times a hand has been detected is an odd number, the process proceeds to S8. On the other hand, if S7 returns "NO", i.e., the number of times a hand has been detected is an even number, the process proceeds to S9. Note that the control processes of S4 to S6 may be executed after the control processes of S7 to S9, or may be executed in parallel with the control processes of S7 to S9.

In S8, the first control unit 32a is activated (ON). This causes power to be supplied from the first control unit 32a to the electric blower 26, and the operation of the electric blower 26 begins. Meanwhile, in S9, the second control unit 32b is activated (ON). This causes power to be supplied from the second control unit 32b to the electric blower 26, and the operation of the electric blower 26 begins.

In this way, the central processing unit 38 selects and operates the first control unit 32a when the number of times a hand is detected is an odd number, and selects and operates the second control unit 32b when the number of times a hand is detected is an even number. As a result, when the electric blower 26 is operating, the first control unit 32a and the second control unit 32b operate alternately. Note that the second control unit 32b may be selected when the number of times a hand is detected is an odd number, and the first control unit 32a may be selected when the number of times a hand is detected is an even number.

In the next step S10, it is determined whether a hand has been detected. That is, the central processing unit 38 determines whether the hand detection sensor 22 has detected a hand. If S10 returns "YES", that is, if a hand has been detected, the detection of the hand is monitored. On the other hand, if S10 returns "NO", that is, if a hand has not been detected, the process proceeds to S11.

In S11, the first, second and other control units 32a, 32b, 34 are deactivated (OFF). This stops the operation of the electric blower 26 and the heater 30. Then, in the next step S12, the operation history information of each control unit 32a, 32b, 34 is updated. That is, the central processing unit 38 counts up the number of times the hand has been detected by one, and stores the operation time of each control unit 32a, 32b, 34 in the memory unit 39, and the process ends.

Next, a case where the operation of each of the control sections 32a, 32b, and 34 is prohibited will be described with reference to FIG.
6 is a graph showing a simplified diagram of the temperature transition of the control units. In this embodiment, the temperature transition of the first control unit 32a will be described as a representative example.

As described above, the first control unit 32a and the second control unit 32b operate alternately. However, if the hand dryer 10 is used continuously for a long period of time, the temperature Tj of the first control unit 32a will gradually increase, as shown in FIG. 6. If the temperature Tj of the first control unit 32a becomes high, there is a risk that the first control unit 32a will not operate properly.

Therefore, the central processing unit 38 estimates the temperature Tj of the first control unit 32a based on the room temperature Ta and the operation history information of the first control unit 32a. The central processing unit 38 calculates the temperature of the first control unit 32a using the following formula 1, for example, given room temperature Ta, operation (ON) time of the first control unit 32a (i.e., hand detection time) t on , operation (OFF) time of the first control unit 32a (i.e., hand non-detection time) t off , heat generation coefficient Ku, and heat dissipation coefficient Kd.

The above formula 1 produces a graph such as that shown in FIG. 6. As shown in FIG. 6, for example, when the temperature Tj of the first control unit 32a reaches the temperature threshold value Tjmax at ton4, the operation of at least the first control unit 32a is prohibited. Then, the first control unit 32a dissipates heat by the heat dissipation material 36 (heat dissipation unit 36a) at toff4, and the prohibition on operation is released when the temperature Tj reaches the release threshold value Tjs (when it drops to the release threshold value Tjs).

In this embodiment, when the operation of the first control unit 32a or the second control unit 32b is prohibited in S3 of FIG. 5, the electric blower 26 is not operated. Note that the prohibition on operation of the first control unit 32a is not necessarily lifted when the temperature Tj reaches the release threshold value Tjs, but may be lifted, for example, after a predetermined time has elapsed since operation was prohibited. This predetermined time can be appropriately set by experiment or simulation, taking into consideration, for example, the heat dissipation efficiency of the heat dissipation material 36 and the environment of the place where the hand dryer 10 is installed.

FIG. 7 is a block diagram showing an electrical system of a hand dryer according to a first modified example of the present invention.
In the above-described embodiment, an example has been described in which the first AC load unit is electric blower 26 and the second AC load unit is heater 30. However, the present invention is not limited to this example, and for example, as in a first modified example shown in Fig. 7, the first AC load unit may be heater 50 and the second AC load unit may be electric blower 52.

FIG. 8 is a block diagram showing an electrical system of a hand dryer according to a second modified example of the present invention.
In the above-described embodiment, an example has been described in which the hand dryer 10 is provided with one electric blower 26. However, the present invention is not limited to this, and for example, as in a second modified example shown in Fig. 8, the hand dryer may be provided with two electric blowers, a first electric blower 54 and a second electric blower 56, with the first AC load unit being the first electric blower 54 and the second AC load unit being the second electric blower 56.

FIG. 9 is a block diagram showing an electrical system of a hand dryer according to a third modified example of the present invention.
In the above-described embodiment, the control unit 32 has two control units, a first control unit 32a and a second control unit 32b. However, the present invention is not limited to this. For example, as in a third modified example shown in FIG. 9, the control unit 60 may have a first control unit 60a, a second control unit 60c, and a third control unit 60c. The first to third control units 60a to 60c may operate in sequence. The control unit may have four or more control units, and these multiple control units may operate in sequence.

In the above embodiment, the first heat dissipation section 36a, the second heat dissipation section 36b, and the third heat dissipation section 36c are formed continuously as one heat dissipation material 36. However, the present invention is not limited to this, and for example, the first heat dissipation section 36a, the second heat dissipation section 36b, and the third heat dissipation section 36c may each be a separate heat dissipation material (e.g., three heat dissipation materials). Also, the first heat dissipation section 36a and the second heat dissipation section 36b that dissipate heat from the control unit 32 may be formed continuously as one heat dissipation material, and the third heat dissipation section 36c that dissipates heat from the other control section 34 may be a separate heat dissipation material.

In the above-described embodiment, the operation information for selecting the first control unit 32a or the second control unit 32b is the number of times a hand is detected. However, the present invention is not limited to this, and the operation information may be, for example, the continuous operation time or the accumulated operation time of the hand detection sensor 22. In other words, the selection between the first control unit 32a and the second control unit 32b may be switched based on the detection time of the hand detection sensor 22 and the detection time threshold.

In addition, the first control unit 32a may be activated by first setting the first flag ON and the second flag OFF, and the next time, the second flag may be set ON and the first flag OFF to activate the second control unit 32b.

In the above-described embodiment, the temperature of each of the control units 32a, 32b, and 34 is calculated using an arithmetic formula. However, the present invention is not limited to this, and for example, the temperature Tj of each of the control units 32a, 32b, and 34 may be measured directly using a temperature sensor or the like.

In the above embodiment, for example, when the operation of the first control unit 32a or the second control unit 32b is prohibited in S3 of FIG. 5, the electric blower 26 is not operated. However, the present invention is not limited to this, and for example, the electric blower 26 may be operated by a control unit whose operation is not prohibited. In other words, it is sufficient to at least prohibit the operation of a control unit whose temperature Tj is equal to or higher than the temperature threshold value Tjmax. This makes it possible to reduce the time during which the hand dryer 10 is prohibited from use.

In the above-described embodiment, the first AC load unit is the electric blower 26, and the second AC load unit is the heater 30. However, the present invention is not limited to this embodiment. For example, the hand dryer 10 may be provided with another electric blower in addition to the electric blower 26 for drying the hands. This other electric blower draws air, for example, from the drying chamber 14 and blows the air toward the room in which the hand dryer 10 is installed. This other electric blower may constitute the first AC load unit or the second AC load unit.

The above describes the embodiments of the present invention. However, the present invention is not limited to these descriptions. Any design modifications made by a person skilled in the art to the above-mentioned embodiments are also included within the scope of the present invention as long as they include the features of the present invention. For example, the shape, dimensions, material, arrangement, etc. of each element of a hand dryer are not limited to those exemplified, and can be modified as appropriate. Furthermore, the elements of each of the above-mentioned embodiments can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention.

LIST OF SYMBOLS 10 Hand dryer 12 Main body 12a Front 12b Rear 12c Side 12d Side 14 Drying chamber 15 Air outlet 18 Vent 20 Tray 22 Hand detection sensor 24 Room temperature sensor 26 Electric blower 28 Air passage 30 Heater 32 Control unit 32a First control unit 32b Second control unit 34 Other control units 36 Heat dissipation material 36a First heat dissipation unit 36b Second heat dissipation unit 36c Third heat dissipation unit 38 Central processing unit 39 Memory unit 50 Heater 52 Electric blower 54 First electric blower 56 Second electric blower 60 Control unit 60a First control unit 60b Second control unit 60c Third control unit

Claims (8)

a drying chamber for drying the inserted hands;
A hand detection sensor that detects a hand inserted into the drying chamber;
A first AC load unit that is activated by detection of the hand detection sensor;
a first control unit and a second control unit that control power supply to the first AC load unit;
a central processing unit that controls the operation of the first control unit and the second control unit;
a first heat dissipation portion that dissipates heat from the first control portion by contacting the first control portion;
a second heat dissipation portion that dissipates heat from the second control portion by contacting the second control portion;
Equipped with
The central processing unit selects operation of the first control unit or the second control unit based on operation information from the hand detection sensor, and switches the control unit to be operated when the operation information meets a threshold value based on switching . The hand dryer according to claim 1, characterized in that the first AC load unit is an electric blower that blows air toward the drying chamber. The hand dryer according to claim 1 or 2, characterized in that the operation information is the number of times the hand detection sensor detects a hand. The hand dryer according to any one of claims 1 to 3, characterized in that the first heat dissipation section and the second heat dissipation section are formed continuously. The device further includes a second AC load unit that is activated by detection of the hand detection sensor, another control unit that is connected to the central processing unit and controls the second AC load unit, and a third heat dissipation unit that dissipates heat from the other control unit by contacting the other control unit,
The hand dryer according to claim 4 , wherein the third heat dissipation portion is formed continuously with the first heat dissipation portion and the second heat dissipation portion. the first control unit, the second control unit, and the other control unit are arranged in parallel such that either the first control unit or the second control unit is located in the center;
The hand dryer according to claim 5 , wherein a distance between the other control unit and the one control unit is greater than a distance between the first control unit and the second control unit. Further comprising a room temperature sensor for detecting a room temperature,
the second AC load unit is a heater that heats air blown toward the drying chamber,
7. The hand dryer according to claim 5, wherein the central processing unit operates the other control units when the room temperature detected by the room temperature sensor is equal to or lower than a room temperature threshold value. a drying chamber for drying the inserted hands;
A hand detection sensor that detects a hand inserted into the drying chamber;
A first AC load unit that is activated by detection of the hand detection sensor;
a first control unit and a second control unit that control power supply to the first AC load unit;
a central processing unit that controls the operation of the first control unit and the second control unit;
a first heat dissipation portion that dissipates heat from the first control portion by contacting the first control portion;
a second heat dissipation portion that dissipates heat from the second control portion by contacting the second control portion;
Equipped with
The central processing unit selects the operation of the first control unit or the operation of the second control unit based on the operation information of the hand detection sensor,
The first heat dissipation portion and the second heat dissipation portion are formed continuously,
The device further includes a second AC load unit that is activated by detection of the hand detection sensor, another control unit that is connected to the central processing unit and controls the second AC load unit, and a third heat dissipation unit that dissipates heat from the other control unit by contacting the other control unit,
the third heat dissipation portion is formed continuously with the first heat dissipation portion and the second heat dissipation portion,
Further comprising a room temperature sensor for detecting a room temperature,
A storage unit that stores operation history information of each of the first control unit, the second control unit, and the other control unit,
The central processing unit:
Calculating the temperature of each of the control units based on the room temperature and the operation history information of each control unit;
A hand dryer characterized in that the operation of at least a control unit whose temperature is equal to or higher than a temperature threshold value is prohibited.