JP2024118049A - Clothes Dryer - Google Patents

Abstract

To provide a clothing dryer (1) which does not have such a risk that the dryness degree cannot be detected during drying of clothing.SOLUTION: A dryness sensor (20) is mounted in a rotary drum (11), a detection electrode (22) for the dryness sensor is connected to dryness detection circuits (52, 54), a grounding electrode (23) of the dryness sensor is connected to the ground, and based on a resistance value between the detection electrode and the grounding electrode at the time when the clothing comes into contact with the dryness sensor, the dryness of the clothing is detected. Here, impedance on the grounding electrode side of the dryness sensor is set to be lower impedance than impedance on the detection electrode side. Thereby, even if clothing rubs with each other in the rotary drum and static electricity generates in the clothing, when the clothing comes into contact with the grounding electrode, the static electricity is discharged to the ground quickly from the grounding electrode. Therefore, a situation where the dryness detection circuit is broken due to static electricity and the dryness degree cannot be detected can be prevented.SELECTED DRAWING: Figure 3

Description

The present invention relates to a clothes drying device that dries clothes by placing clothes inside a rotating drum and rotating the drum while supplying heated air into the inside of the drum.

In a clothes drying device, clothes are placed inside a rotating drum, and the clothes are dried by supplying heated air into the drum while the drum is rotating to agitate the clothes. If the drum continues to rotate while supplying heated air after the clothes are dry, not only is energy wasted, but the heated clothes may be damaged by rubbing against each other.

A technology has been proposed in which a dryness sensor is attached to a position facing the inside of the rotating drum, and the degree of dryness of the clothes is detected based on the resistance value when the clothes rotating inside the rotating drum touch a pair of electrodes of the dryness sensor (Patent Document 1). According to this proposed technology, when the degree of dryness of the clothes exceeds a predetermined value, the temperature and flow rate of the heated air supplied to the rotating drum are suppressed, making it possible to prevent energy waste and damage to the clothes.

JP 2021-183027 A

However, the above proposed technology had the problem that it was sometimes impossible to detect the degree of dryness of the clothes while the clothes dryer was operating.

This invention was made to solve the above-mentioned problems in the conventional technology, and aims to provide a clothes dryer that eliminates the risk of not being able to detect the degree of dryness of clothes while they are being dried.

In order to solve the above-mentioned problems, the clothes drying device of the present invention adopts the following configuration.
A clothes drying device that dries clothes in a rotating drum by supplying heated air into the inside of the rotating drum while rotating the rotating drum,
A dryness sensor mounted facing the interior of the rotating drum;
a dryness detection circuit connected to the dryness sensor for detecting the degree of dryness of the clothes being dried inside the rotating drum;
The dryness sensor includes:
a detection electrode exposed inside the rotary drum and having a predetermined voltage applied thereto via a predetermined voltage dividing resistor;
a ground electrode that is exposed inside the rotating drum at a position adjacent to the detection electrode and is connected to earth;
a voltage value between the voltage dividing resistor and the detection electrode is input to the dryness detection circuit as an output of the dryness sensor;
the dryness detection circuit detects the degree of dryness based on an input from the dryness sensor when the laundry is in contact with the detection electrode and the ground electrode;
The impedance of the ground electrode side of the dry sensor is lower than the impedance of the detection electrode side.

In the clothes drying device of the present invention, the detection electrode and ground electrode of the dryness sensor are exposed inside the rotating drum, the detection electrode is connected to a dryness detection circuit, and the ground electrode is connected to earth. Then, when the clothes inside the rotating drum come into contact with the detection electrode and the ground electrode as the rotating drum rotates, the degree of dryness of the clothes is detected based on the voltage value input from the dryness sensor to the dryness detection circuit. Here, the impedance of the ground electrode side of the dryness sensor is lower than the impedance of the detection electrode side.

Generally, as the clothes rotating in the rotating drum become dry, static electricity can be generated by the clothes rubbing against each other, and the voltage of this static electricity can reach several thousand volts. For this reason, when charged clothes come into contact with the dryness sensor, high-voltage static electricity is applied to the dryness detection circuit, which may damage the dryness detection circuit. However, if the impedance of the ground electrode side of the dryness sensor is set to be lower than the impedance of the detection electrode side, the static electricity of the clothes can be released from the ground electrode to earth, and the static electricity voltage can be quickly reduced. This makes it possible to prevent a situation in which static electricity generated in the clothes while they are drying damages the dryness detection circuit, making it impossible to detect the degree of dryness.

In addition, in the clothes drying device of the present invention described above, the ground electrode of the drying sensor may be positioned on the opposite side of the detection electrode to the direction of rotation of the rotating drum.

In this way, the clothes rotating inside the rotating drum approach the dryness sensor from the side where the ground electrode is located. Therefore, the clothes first come into contact with the ground electrode and then the detection electrode. Even if the clothes are charged with static electricity, the static electricity is released from the ground electrode to ground before the clothes come into contact with the detection electrode. This makes it possible to reliably prevent the dryness detection circuit from being damaged by static electricity from the clothes.

In addition, in the clothes drying device of the present invention described above, a fixed member that does not rotate even when the rotating drum is rotating can be mounted at a position facing the inside of the rotating drum, and a dryer sensor can be attached to the side of this fixed member facing the inside of the rotating drum with the ground electrode oriented above the detection electrode.

In this way, when the clothes are lifted upward by the rotation of the rotating drum and then come into contact with the dryness sensor as they fall, they will come into contact with the ground electrode to release static electricity before coming into contact with the detection electrode. This makes it possible to reliably prevent the dryness detection circuit from being damaged by static electricity generated in the clothes.

In addition, in the clothes drying device of the present invention in which the ground electrode is disposed on the opposite side of the direction of rotation of the rotating drum or above the detection electrode of the dryness sensor, the dryness sensor may be provided with an indirect ground electrode connected to earth via a dryness detection circuit, and a direct ground electrode connected to earth not via a dryness detection circuit, and these two electrodes may form a ground electrode. The detection electrode and direct ground electrode of the dryness sensor may be disposed on both sides of the indirect ground electrode, and the impedance of the direct ground electrode side may be lower than the impedance of the detection electrode side.

In this way, the electrodes of the dryness sensor are arranged in the following order from the perspective of the clothes approaching the dryness sensor: direct ground electrode, indirect ground electrode, and detection electrode. Therefore, even if the clothes are charged with static electricity, the static electricity in the clothes can be quickly discharged from the direct ground electrode to the earth, so high-voltage static electricity is not applied to the dryness detection circuit. As a result, it is possible to reliably prevent the dryness detection circuit from being damaged by static electricity generated in the clothes. In addition, since the indirect ground electrode is connected to the earth via the dryness detection circuit, no potential difference occurs between the earth of the dryness detection circuit and the earth of the indirect ground electrode, and the potential of the detection electrode based on the potential of the indirect ground electrode can be accurately detected. As a result, it is possible to accurately detect the degree of dryness of the clothes.

In addition, in the clothes drying device of the present invention described above, the direct ground electrode may be positioned so that it protrudes toward the inside of the rotating drum more than the detection electrode.

This ensures that the clothes in the rotating drum come into direct contact with the ground electrode before they come into contact with the indirect ground electrode or the detection electrode. This makes it possible to reliably prevent the dryness detection circuit from being damaged by static electricity generated in the clothes.

1 is an explanatory diagram showing a rough internal structure of a clothes drying device 1 according to a first embodiment; 1 is an explanatory diagram showing a state in which the dryness sensor 20 of the first embodiment is mounted on a ring plate 12. FIG. FIG. 2 is an explanatory diagram showing the internal structure of a control unit 50 according to the first embodiment. 4 is an explanatory diagram showing a state in which clothes in the rotating drum 11 come into contact with the dryness sensor 20 of the first embodiment. FIG. 10 is an explanatory diagram of a dryness sensor 20 according to a modified example of the first embodiment. FIG. 10 is an explanatory diagram of a dryness sensor 20 according to another modified example of the first embodiment. FIG. 10 is an explanatory diagram of a dryness sensor 20 according to another modified example of the first embodiment. FIG. 10 is an explanatory diagram of a dryness sensor 20 according to another modified example of the first embodiment. FIG. 13 is an explanatory diagram of a dryness sensor 20 of a second embodiment mounted on a ring plate 12. FIG. FIG. 11 is an explanatory diagram showing the internal structure of a control unit 50 according to a second embodiment. 11 is an explanatory diagram showing a state in which clothes in the rotating drum 11 come into contact with a dryness sensor 20 of the second embodiment. FIG. 13 is an explanatory diagram of a dryness sensor 20 according to a modified example of the second embodiment. FIG. 13 is an explanatory diagram of a dryness sensor 20 according to another modified example of the second embodiment. FIG. 13 is an explanatory diagram of a dryness sensor 20 according to another modified example of the second embodiment. FIG.

A. First embodiment:
1 is an explanatory diagram showing the general internal structure of a clothes dryer 1 according to the first embodiment. The clothes dryer 1 according to the first embodiment has a structure in which a cylindrical rotating drum 11 with a bottom is mounted inside a rectangular parallelepiped main body case 10. A rotating shaft 14 protruding outward is attached to the center of a bottom 11a of the rotating drum 11, and the rotating drum 11 is supported rotatably around the rotating shaft 14.

A circular ring plate 12 is fitted into the front open end of the rotating drum 11 in a state where it can slide relative to the rotating drum 11, and a cylindrical clothing insertion section 13 with one end expanded in a flange shape is attached to the inner circumference of the ring plate 12. The flange-shaped part of the clothing insertion section 13 is attached to the main body case 10, and therefore the ring plate 12 is fixed to the main body case 10 via the clothing insertion section 13. In addition, a dryness sensor 20 is attached to the ring plate 12 at a position facing the inside of the rotating drum 11. The dryness sensor 20 is connected to the control section 50 described later, and the control section 50 is able to detect the degree of dryness of the clothes in the rotating drum 11 based on the output of the dryness sensor 20. The ring plate 12 in the first embodiment corresponds to the "fixed member" in this invention.

The inside of the clothing insertion section 13 is a clothing insertion port 13a, which is normally blocked by an opening/closing door 15. When the opening/closing door 15 is opened, clothing can be inserted into the rotating drum 11 through the clothing insertion port 13a. In addition, a plurality of exhaust ports 11b are formed in the bottom 11a of the rotating drum 11, and the plurality of exhaust ports 11b are covered by a filter 16 attached to the bottom 11a from the inside of the rotating drum 11. Furthermore, a fan cover 17 is mounted on the other side of the bottom 11a, and a blower fan 33 is stored inside the fan cover 17. The blower fan 33 is attached to the rotating shaft 14 of the rotating drum 11. An exhaust passage 18 extends from the fan cover 17, and the tip of the exhaust passage 18 protrudes from the top surface of the main body case 10 to form an exhaust port 18a.

An electric motor 30 is mounted below the rotating drum 11 and the fan cover 17, and two transmission belts 31, 32 are attached to the electric motor 30. When the electric motor 30 is rotated, the rotational torque of the electric motor 30 is transmitted to the rotating drum 11 via the transmission belt 31, and the rotational torque of the electric motor 30 is transmitted to the blower fan 33 via the transmission belt 32, causing the rotating drum 11 and the blower fan 33 to rotate.

Below the rotating drum 11, there is also mounted a gas burner 40 for burning fuel gas, and a gas pipe 41 for supplying fuel gas to the gas burner 40. An injection nozzle 42 is attached to the tip of the gas pipe 41, and the injection nozzle 42 is provided in a position facing the open end 40a of the gas burner 40. Furthermore, a gas flow control valve 43 is mounted midway along the gas pipe 41. An air supply passage 44 is formed from the gas burner 4 toward the upper side, and the air supply passage 44 is connected to a supply port 45 formed in the ring plate 12.

When drying clothes with the clothes dryer 1, the door 15 is opened and clothes are put into the rotating drum 11 through the clothes inlet 13a, then the door 15 is closed and the electric motor 30 is rotated. Then, the rotating drum 11 and the blower fan 33 rotate, and air inside the rotating drum 11 is sucked out through the multiple exhaust ports 11b formed in the bottom 11a of the rotating drum 11, and air flows into the rotating drum 11 through the supply port 45. In addition, multiple air intakes 10a are formed in the bottom surface of the main body case 10, and air that flows into the main body case 10 from the air intakes 10a is supplied to the rotating drum 11 through the air supply passage 44 and the supply port 45.

When fuel gas is injected from the injection nozzle 42 toward the open end 40a of the gas burner 40 while the blower fan 33 is rotating in this manner, the injected fuel gas flows into the gas burner 40 together with the surrounding air, forming a mixture of fuel gas and air. The mixture is ignited by a spark plug (not shown), and combustion in the gas burner 40 begins. The combustion exhaust generated by the gas burner 40 flows into the air supply passage 44 together with the air flowing in from the air intake 10a on the bottom surface of the main body case 10, and is mixed with the air in the air supply passage 44 to generate heated air, which then flows into the rotating drum 11 from the supply port 45. The heated air dries the clothes while swirling in the rotating drum 11, and then flows out from the exhaust port 11b formed in the bottom 11a of the rotating drum 11. The heated air that has thus dried the clothes passes through the exhaust passage 18 and is discharged from the exhaust port 18a.

The main body case 10 also contains a control unit 50 for controlling the operation of the electric motor 30 and the gas flow control valve 43. The control unit 50 is formed from various electronic components, and the output of the dryness sensor 20 described above is input to the control unit 50.

2 is an explanatory diagram showing the dry sensor 20 mounted on the ring plate 12. FIG. 2 shows the state seen from inside the rotating drum 11. As shown in the figure, the dry sensor 20 has a base 21 formed of an insulating material such as hard resin, a detection electrode 22, and a ground electrode 23, and the detection electrode 22 and the ground electrode 23 slightly protrude from the surface of the base 21. In the example shown in FIG. 2, the detection electrode 22 and the ground electrode 23 protrude from the surface of the base 21, but the detection electrode 22 and the ground electrode 23 may be exposed on the surface of the base 21. The dry sensor 20 is attached to the ring plate 12 in a state facing the inside of the rotating drum 11, and the orientation of the dry sensor 20 at this time is such that the ground electrode 23 is positioned opposite to the rotation direction of the rotating drum 11 (indicated by the dashed arrow in the figure) with respect to the detection electrode 22. Both the detection electrode 22 and the ground electrode 23 are connected to the control unit 50 (see FIG. 1).

Figure 3 is an explanatory diagram showing the internal structure of the control unit 50. As shown in the figure, the control unit 50 houses a control board 51, on which a microcomputer 52, a power supply unit 53, a detection circuit 54, and the like are mounted. The microcomputer 52 is a semiconductor element in which a central processing unit, memory, and the like are integrated on one chip, and operates when a predetermined specified voltage is applied from the power supply unit 53 and when it is connected to the ground GND formed on the control board 51. The detection circuit 54 is an electronic circuit formed by combining semiconductor elements such as an operational amplifier and a comparator, and operates when a specified voltage is applied from the power supply unit 53 and when it is connected to the ground GND on the control board 51. The microcomputer 52 and the detection circuit 54 are connected to the ground GND at different positions. In the first embodiment, the microcomputer 52 and the detection circuit 54 correspond to the "dryness detection circuit" in the present invention.

The detection electrode 22 of the dry sensor 20 is connected to the control unit 50, and inside the control unit 50, it is connected to the detection circuit 54 via a protective resistor R2. Furthermore, a specified voltage supplied from the power supply unit 53 is applied to the detection electrode 22 via a voltage dividing resistor R1, and the voltage between the voltage dividing resistor R1 and the detection electrode 22 is input to the detection circuit 54. The ground electrode 23 of the dry sensor 20 is also connected to the control unit 50, and inside the control unit 50, it is connected to the ground GND on the control board 51. Although not shown, the ground GND of the control board 51 shown in FIG. 3 is connected to earth through the main body case 10.

In this way, inside the control unit 50 of the first embodiment, the detection electrode 22 of the dryness sensor 20 is connected to the detection circuit 54 via the protective resistor R2, while the ground electrode 23 of the dryness sensor 20 is directly connected to the ground GND of the control board 51. For this reason, the impedance on the ground electrode 23 side is lower than the impedance on the detection electrode 22 side. As will be described in detail later, this makes it possible to prevent a situation in which the detection circuit 54 breaks down during operation of the clothes dryer 1, making it impossible to detect the degree of dryness of the clothes. As a prelude to explaining the reason for this, the principle of detecting the degree of dryness of clothes using the dryness sensor 20 will be explained.

Figure 4 is an explanatory diagram showing how the clothes in the rotating drum 11 come into contact with the dryness sensor 20 of the first embodiment. Figure 4(a) shows the state before the clothes come into contact with the dryness sensor 20, and Figure 4(b) shows the state in which the clothes come into contact with the dryness sensor 20. As shown in Figure 4(a), when the clothes are not in contact with the dryness sensor 20, the detection electrode 22 and the ground electrode 23 are insulated by air. However, as shown in Figure 4(b), when the wet clothes being dried come into contact with the dryness sensor 20, a current flows from the detection electrode 22 to the ground electrode 23. At this time, the resistance value between the detection electrode 22 and the ground electrode 23 becomes smaller as the clothes become wetter. Conversely, after the clothes are dried, almost no current flows from the detection electrode 22 to the ground electrode 23 even if the clothes come into contact with the dryness sensor 20, and the resistance value between the detection electrode 22 and the ground electrode 23 remains large.

Therefore, while the clothes in the rotating drum 11 are wet, the resistance between the detection electrode 22 and the ground electrode 23 drops significantly each time the clothes come into contact with the dryness sensor 20, but as the clothes dry, the amount of drop in resistance decreases, and after the clothes are completely dry, there is almost no drop in resistance even when the clothes come into contact with the dryness sensor 20. Therefore, by connecting the detection electrode 22 and the ground electrode 23 to the control unit 50 and detecting the drop in resistance between the detection electrode 22 and the ground electrode 23, it is possible to detect the degree of dryness of the clothes.

In the clothes dryer 1 of the first embodiment, in order to detect a change in the resistance value between the detection electrode 22 and the ground electrode 23, a specified voltage is applied to the detection electrode 22 from the power supply unit 53 via a voltage dividing resistor R1 as shown in FIG. 3, and the voltage between the voltage dividing resistor R1 and the detection electrode 22 is input to the detection circuit 54. In this way, the lower the resistance value between the detection electrode 22 and the ground electrode 23, the lower the voltage value input to the detection circuit 54. Therefore, by detecting a decrease in this voltage value and detecting a decrease in the resistance value between the detection electrode 22 and the ground electrode 23, the degree of dryness of the clothes can be detected.

However, because the clothes dryer 1 dries the clothes while agitating them in the rotating drum 11, as the clothes dry, they may rub against each other, generating static electricity. Although the charge of this static electricity is small, the voltage value may reach several thousand volts. For this reason, when statically charged clothes come into contact with the drying sensor 20, the high voltage of the static electricity may damage the detection circuit 54 in the control unit 50.

Therefore, in the clothes dryer 1 of the first embodiment, as shown in FIG. 3, the detection electrode 22 of the dryness sensor 20 is connected to the detection circuit 54 via a protective resistor R2, and the ground electrode 23 of the dryness sensor 20 is directly connected to the ground GND of the control board 51, so that the impedance of the ground electrode 23 side of the dryness sensor 20 is lower than the impedance of the detection electrode 22 side. In this way, even if high-voltage static electricity is generated in the clothes, when the clothes come into contact with the dryness sensor 20, the static electricity is released to the ground GND via the low-impedance ground electrode 23, and the voltage of the static electricity can be quickly reduced. As a result, it is possible to avoid a situation in which the detection circuit 54 is damaged by high-voltage static electricity charged in the clothes.

In addition, since the clothes inside the rotating drum 11 move due to the rotation of the rotating drum 11, the clothes being dried approach the dryness sensor 20 from one direction (the direction of rotation of the rotating drum 11) as shown by the dashed arrow in FIG. 4(a). The dryness sensor 20 is attached so that the ground electrode 23 is located on the opposite side of the direction of rotation of the rotating drum 11 relative to the detection electrode 22 (see FIG. 2). Therefore, clothes that come into contact with the dryness sensor 20 come into contact with the ground electrode 23 before coming into contact with the detection electrode 22, releasing static electricity to the ground electrode 23, and then come into contact with the detection electrode 22 in a state where the static electricity voltage has been reduced. As a result, it is possible to reliably prevent the detection circuit 54 from being damaged by the static electricity voltage charged to the clothes.

There are several variations of the clothes drying device 1 of the first embodiment described above. Below, these variations will be explained, focusing on the differences from the first embodiment.

In the first embodiment described above, the detection electrode 22 and the ground electrode 23 of the dryness sensor 20 are described as protruding from the base 21 to the same extent. However, as illustrated in FIG. 5, the ground electrode 23 may be made to protrude further than the detection electrode 22. In this way, the ground electrode 23 protrudes further inwardly from the rotating drum 11 than the detection electrode 22, so that the garment can come into contact with the ground electrode 23 before coming into contact with the detection electrode 22. As a result, it is possible to reliably prevent the detection circuit 54 from being damaged by the static electricity voltage charged to the garment.

In the above-mentioned first embodiment, the ground electrode 23 is described as being provided at a position opposite to the rotation direction of the rotary drum 11 with respect to the detection electrode 22. However, as illustrated in FIG. 6, one end of the ground electrode 23 may be extended to a position opposite to the direction of gravity (i.e., upward) with respect to the detection electrode 22. For example, as illustrated in FIG. 6(a), if the position where the dryness sensor 20 is attached to the ring plate 12 is a position above the clothes inlet 13a of the clothes drying device 1, the right end of the ground electrode 23 is extended to a position above the detection electrode 22 when the ground electrode 23 is viewed from the detection electrode 22. Alternatively, as illustrated in FIG. 6(b), if the dryness sensor 20 is attached to the ring plate 12 at a position below the clothes inlet 13a, the left end of the ground electrode 23 is extended to a position above the detection electrode 22 when the ground electrode 23 is viewed from the detection electrode 22.

In the rotating drum 11, there is a possibility that clothes lifted by the rotation of the rotating drum 11 may come into contact with the dryness sensor 20 when they fall due to gravity. Even in such a case, if one end of the ground electrode 23 is extended to a position above the detection electrode 22, the clothes will come into contact with the ground electrode 23 before coming into contact with the detection electrode 22. This makes it possible to reliably prevent the detection circuit 54 from being damaged by the static electricity voltage charged to the clothes.

In the example shown in FIG. 6, one end of the ground electrode 23 is described as extending to a position above the detection electrode 22. However, instead of extending one end of the ground electrode 23, as shown in FIG. 7, two ground electrodes 23 may be provided, with one ground electrode 23 provided on the opposite side of the detection electrode 22 in the direction of rotation of the rotating drum 11, and the other ground electrode 23 provided above the detection electrode 22.

Also, as shown in FIG. 8, a ground electrode 23 may be provided so as to surround the periphery of the detection electrode 22. The ground electrode 23 surrounding the periphery of the detection electrode 22 may be a single ground electrode 23 as shown in FIG. 8, or may be multiple ground electrodes 23. In this way, regardless of the direction in which the clothes approach the dryness sensor 20, the clothes will always come into contact with the ground electrode 23 before the detection electrode 22. Therefore, even if high-voltage static electricity is generated in the clothes, it is possible to reliably prevent the detection circuit 54 from being damaged by the static electricity in the clothes.

B. Second embodiment:
In the above-mentioned first embodiment, the ground electrode 23 for detecting the resistance value of the clothing between the detection electrode 22 and the detection electrode 22 is described as having a function for dissipating static electricity generated in the clothing. However, a ground electrode for dissipating static electricity in the clothing may be provided separately from the ground electrode 23 for detecting the resistance value of the clothing. The following describes such a second embodiment, focusing on the differences from the above-mentioned first embodiment.

9 is an explanatory diagram showing the dryness sensor 20 of the second embodiment mounted on the ring plate 12. As in FIG. 2 described above, FIG. 9 also shows the state seen from inside the rotating drum 11. In addition, in the figure, the rotation direction of the rotating drum 11 is indicated by a dashed arrow. As shown in FIG. 9, the dryness sensor 20 of the second embodiment is different from the first embodiment described above using FIG. 2 in that it has two types of ground electrodes 23, an indirect ground electrode 23a and a direct ground electrode 23b. As in the first embodiment described above, the positions at which these ground electrodes 23 are mounted with respect to the detection electrode 22 are opposite to the rotation direction of the clothes drying device 1, but the direct ground electrode 23b is mounted at a position on the other side of the indirect ground electrode 23a as seen from the detection electrode 22. In addition, all of these electrodes (the indirect ground electrode 23a, the direct ground electrode 23b, and the detection electrode 22) are connected to the control unit 50 (see FIG. 1).

Figure 10 is an explanatory diagram showing the state in which the dry sensor 20 of the second embodiment is connected to the control unit 50. As described above with reference to Figure 3, the control board 51 inside the control unit 50 is equipped with a microcomputer 52, a power supply unit 53, a detection circuit 54, and the like. As in the first embodiment described above, a specified voltage is applied to the detection electrode 22 of the dry sensor 20 from the power supply unit 53 via a voltage dividing resistor R1, and the voltage between the voltage dividing resistor R1 and the detection electrode 22 is input to the detection circuit 54 via a protective resistor R2. Also, like the ground electrode 23 of the first embodiment described above, the direct ground electrode 23b is connected to the ground GND on the control board 51 at a position different from the microcomputer 52 and the detection circuit 54. However, the indirect ground electrode 23a is connected to the detection circuit 54 and is connected to the ground GND on the control board 51 via the detection circuit 54. In the second embodiment, the impedance of the direct ground electrode 23b is lower than the impedance of the detection electrode 22 side. Although not shown, the ground GND of the control board 51 shown in FIG. 10 may be connected to earth through the main body case 10, as in the first embodiment described above. Also, the detection electrode 22 and the indirect ground electrode 23a may be connected to a common ground GND on the control board 51, and the direct ground electrode 23b may be connected to earth through the main body case 10.

Figure 11 is an explanatory diagram showing how the dryness of clothes in the rotating drum 11 is detected using the dryness sensor 20 of the second embodiment. As shown in Figure 11 (a), the clothes in the rotating drum 11 approach the dryness sensor 20 from the direction in which the rotating drum 11 rotates. Here, the three electrodes (direct ground electrode 23b, indirect ground electrode 23a, detection electrode 22) of the dryness sensor 20 of the second embodiment are arranged in this order in the direction in which the rotating drum 11 rotates. Therefore, the clothes in the rotating drum 11 first come into contact with the direct ground electrode 23b as shown in Figure 11 (b), and then come into contact with the indirect ground electrode 23a and the detection electrode 22 as shown in Figure 11 (c). As described above with reference to FIG. 10, the direct ground electrode 23b is directly connected to the ground GND of the control board 51 in the control unit 50, and therefore has a lower impedance than the indirect ground electrode 23a and the detection electrode 22. Therefore, even if static electricity is generated in the clothing, the static electricity can be quickly discharged from the direct ground electrode 23b. Therefore, even if the clothing comes into contact with the indirect ground electrode 23a and the detection electrode 22, it is possible to prevent the detection circuit 54 from being damaged by the static electricity charged in the clothing.

In the second embodiment described above, the detection electrode 22, the indirect ground electrode 23a, and the direct ground electrode 23b of the dryness sensor 20 are described as protruding from the base 21 to the same extent. However, as illustrated in FIG. 12, the direct ground electrode 23b may be made to protrude further than the other electrodes. This ensures that the garment comes into contact with the direct ground electrode 23b before it comes into contact with the indirect ground electrode 23a or the detection electrode 22. As a result, it is possible to reliably prevent the detection circuit 54 from being damaged by the static electricity voltage charged to the garment.

In the second embodiment described above, the indirect ground electrode 23a and the direct ground electrode 23b are described as being provided on the opposite side of the detection electrode 22 in the direction of rotation of the rotating drum 11. However, as shown in FIG. 13(a) or 13(b), one end of the direct ground electrode 23b may be extended to a position above the indirect ground electrode 23a and the detection electrode 22.

Alternatively, as shown in FIG. 14, a direct ground electrode 23b may be provided to surround the detection electrode 22 and the indirect ground electrode 23a. The direct ground electrode 23b surrounding the detection electrode 22 and the indirect ground electrode 23a may be one as shown in FIG. 14, or multiple direct ground electrodes 23b. In this way, regardless of the direction in which the clothes approach the dryness sensor 20, the clothes come into contact with the direct ground electrode 23b before the detection electrode 22 and the indirect ground electrode 23a, so that it is possible to reliably prevent the detection circuit 54 from being damaged by the static electricity voltage charged to the clothes.

Although various embodiments and modifications of the clothes drying device 1 have been described above, the present invention is not limited to the above embodiments and modifications, and can be implemented in various forms without departing from the spirit of the invention.

For example, in the various embodiments and variants described above, the dryness sensor 20 has been described as being attached to a fixed member (e.g., ring plate 12) even while the rotating drum 11 is rotating. However, the dryness sensor 20 may be attached to a position facing the inside of the rotating drum 11, or may be attached to a member that rotates together with the rotating drum 11 (e.g., the inner surface of the rotating drum 11). Even in such a case, the dryness sensor 20 can be connected to the control unit 50 by using a part called a slip ring, making it possible to detect the degree of dryness of the clothes.

1... clothes drying device, 10... main body case, 10a... air intake,
11...rotating drum; 11a...bottom; 11b...exhaust port; 12...ring plate;
13...clothing insertion section, 13a...clothing insertion port, 14...rotation shaft,
15: Opening and closing door; 16: Filter; 17: Fan cover;
18...exhaust passage, 18a...exhaust port, 20...dryness sensor, 21...base portion,
22: detection electrode; 23: ground electrode; 23a: indirect ground electrode;
23b...direct ground electrode; 30...electric motor; 31...transmission belt;
32...transmission belt, 33...blower fan, 40...gas burner,
40a...opening end, 41...gas pipe, 42...injection nozzle,
43: gas flow control valve; 44: air supply passage; 45: supply port;
50: control unit, 51: control board, 52: microcomputer,
53: power supply unit; 54: detection circuit.

Claims (5)

A clothes drying device that dries clothes in a rotating drum by supplying heated air into the inside of the rotating drum while rotating the rotating drum,
A dryness sensor mounted facing the interior of the rotating drum;
a dryness detection circuit connected to the dryness sensor for detecting the degree of dryness of the clothes being dried inside the rotating drum;
The dryness sensor includes:
a detection electrode exposed inside the rotary drum and having a predetermined voltage applied thereto via a predetermined voltage dividing resistor;
a ground electrode that is exposed inside the rotating drum at a position adjacent to the detection electrode and is connected to earth;
a voltage value between the voltage dividing resistor and the detection electrode is input to the dryness detection circuit as an output of the dryness sensor;
the dryness detection circuit detects the degree of dryness based on an input from the dryness sensor when the laundry is in contact with the detection electrode and the ground electrode;
The clothes drying device according to claim 1, wherein the impedance of the dryness sensor on the ground electrode side is lower than the impedance of the detection electrode side. The clothes drying apparatus according to claim 1,
The clothes drying device, wherein the ground electrode is disposed on a side opposite to a rotation direction of the rotary drum as viewed from the detection electrode. The clothes drying apparatus according to claim 1,
A fixed member is provided at a position facing the inside of the rotary drum and mounted in a state not to rotate even during rotation of the rotary drum,
the drying sensor is attached to the fixing member on a side facing the inside of the rotating drum, with the ground electrode being higher than the detection electrode. The clothes drying apparatus according to claim 2 or 3,
The ground electrode is
an indirect ground electrode connected to the earth via the dryness detection circuit;
a direct ground electrode connected to the earth without passing through the dryness detection circuit;
the direct ground electrode and the detection electrode are disposed on both sides of the indirect ground electrode,
The clothes drying device according to claim 1, wherein an impedance on the direct ground electrode side is lower than an impedance on the detection electrode side. The clothes drying apparatus according to claim 4,
The clothes drying device, wherein the direct ground electrode is disposed so as to protrude toward an inner side of the rotating drum further than the detection electrode.

Images