A drum having a humidity detecting function

Abstract

The application relates to the field of clothes humidity detection, and specifically provides a drum with a humidity detection function. A cavity is arranged on the inner wall of the drum, the inner surface of the cavity is provided with a detection circuit board, the outer surface of the cavity is in contact with the working space of the drum, the cavity is a wedge-shaped closed chamber, the cavity is surrounded by the inner wall of the drum, a first side wall, a second side wall, a protruding wall, a top wall and a bottom wall, the proximal ends of the first side wall and the second side wall are fixedly arranged on the inner wall of the drum, the distal ends of the first side wall and the second side wall are fixedly connected to the two ends of the protruding wall, the distance between the proximal ends of the first side wall and the second side wall is greater than the distance between the distal ends of the first side wall and the second side wall, the inner side of the first side wall is fixedly provided with a first detection circuit board, and the inner side of the second side wall is fixedly provided with a second detection circuit board. According to the application, the wedge-shaped closed chamber is arranged on the inner wall of the drum, so that the clothes are guided, pressed and closely attached to the outer surface of the side wall in the rotation of the drum. The close attachment makes the capacitance change obvious, thereby improving the humidity detection accuracy.

Description

Technical Field

[0001] This application relates to the field of humidity detection, and more specifically, to a roller with clothing humidity detection function. Background Technology

[0002] In washer-dryer combos or freestanding dryers, accurately detecting the humidity of clothes inside the drum is crucial for drying performance. Clothing humidity not only determines drying time but also whether clothes are over-dried or under-dried. Inaccurate humidity detection can lead to increased energy consumption, damaged clothes, or insufficient drying. Therefore, accurate clothing humidity detection is essential for improving dryer performance and user experience.

[0003] A capacitive humidity detection device is a sensing structure that determines the moisture content of clothing by measuring changes in capacitance, relying on the relationship between an electric field and the properties of the dielectric. It typically consists of two planar electrodes forming an electric field, with the clothing within this field acting as the dielectric. Since the dielectric constant of clothing changes with its moisture content, a higher humidity results in a larger dielectric constant and thus a higher capacitance; conversely, a drier garment has a lower dielectric constant and a lower capacitance. This change in capacitance reflects the current humidity level of the clothing. Because it doesn't require direct moisture measurement but utilizes the characteristics of an electric field to detect humidity, it offers a fast response and is suitable for use in tumble dryers and other drum-type equipment to detect the moisture content of clothing, ultimately providing accurate data for control programs.

[0004] However, if the circuit board with the detection electrodes is directly attached to the inner wall of the drum, the continuous tumbling of the clothes within the drum often results in insufficient contact between the clothes and the detection electrodes. The clothes only briefly glide across the surface of the detection plate without making sufficient contact, causing the capacitance changes to fail to accurately reflect the actual moisture content of the clothes. This instability is particularly pronounced when clothes are loosely stacked, tumbling speeds vary, or the load differs. In other words, the lack of contact between the clothes and the detection device leads to inaccurate moisture detection. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a roller with a humidity detection function, thereby solving the problem of inaccurate humidity detection of clothing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This application provides a roller with humidity detection function. A cavity is provided on the inner wall of the roller, and a detection circuit board is provided on the inner surface of the cavity. The outer surface of the cavity is in contact with the working space of the roller. The cavity is a wedge-shaped closed chamber. The cavity is surrounded by the inner wall of the roller, a first side wall, a second side wall, a protruding wall, a top wall, and a bottom wall. The proximal ends of the first side wall and the second side wall are fixedly disposed on the inner wall of the roller, and the distal ends of the first side wall and the second side wall are fixedly connected to the two ends of the protruding wall. The distance between the proximal ends of the first side wall and the second side wall is greater than the distance between the distal ends. A first detection circuit board is fixedly disposed on the inner side of the first side wall, and a second detection circuit board is fixedly disposed on the inner side of the second side wall.

[0007] A wedge-shaped enclosed cavity is set on the inner wall of the drum. The outer surface of the cavity directly faces the working space of the drum, allowing the clothes tumbling with the drum to come into contact with the wedge-shaped cavity. The cavity is surrounded by the inner wall of the drum, the first side wall, the second side wall, the protruding wall, the top wall, and the bottom wall. The distance between the near ends of the first side wall and the second side wall is greater than the distance between the far ends, forming a wedge-shaped space that gradually narrows towards the protruding wall. This guides, compresses, and locally gathers the clothes near the cavity during the drum's rotation, forcing the clothes to adhere tightly to the outer surfaces of the first and second side walls. Since a first detection circuit board is fixedly installed on the inner side of the first side wall, and a second detection circuit board is fixedly installed on the inner side of the second side wall, the clothes adhering to the outside of the wedge-shaped cavity are within the electric field area formed by the detection circuit boards. This close contact improves the accuracy of the capacitance measurement in responding to the true humidity state. At the same time, in both forward and reverse rotation of the drum, the clothes can fully contact the first and second detection circuit boards, ensuring stable and reliable humidity detection results regardless of the direction of rotation, thus improving the accuracy of humidity detection.

[0008] Furthermore, the first sidewall and the second sidewall extend in the radial direction of the roller, and the lengths of the first sidewall and the second sidewall are equal and both are less than the radius of the roller.

[0009] Furthermore, the protruding wall is arc-shaped and bulges towards the central axis of the roller.

[0010] Furthermore, both the first and second detection circuit boards are provided with electrode plates, the number of which is greater than or equal to 2, and a planar capacitor is formed between the electrode plates. The arrangement direction of the multiple electrode plates is parallel to the roller axis direction.

[0011] Furthermore, the electrode sheet is positioned close to the first sidewall and the second sidewall.

[0012] Furthermore, the edges of the first and second sidewalls are bent outwards from the cavity and welded or riveted to the inner wall of the roller through the bending structure.

[0013] Furthermore, the cavity is cylindrical along the direction of the roller's axis of rotation.

[0014] Furthermore, a transmission window is provided on both the first and second sidewalls. The transmission window is made of a non-metallic material and is located in the area where the first and second detection circuit boards are fixedly installed on the inside.

[0015] Furthermore, the capacitors on the first and second detection circuit boards are connected in parallel for detection, the emitting electrode plates on the first and second detection circuit boards are connected, and the receiving electrode plates on the first and second detection circuit boards are connected.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: In this application, a wedge-shaped enclosed cavity is provided on the inner wall of the drum, with its outer surface directly facing the work space. Clothes tumbling with the drum's rotation will first contact this wedge-shaped outer surface. Because the cavity is enclosed by the inner wall of the drum, a first side wall, a second side wall, and a protruding wall, and the distance between the near ends of the first and second side walls is greater than the distance between their far ends, the cavity has a gradually narrowing wedge-shaped structure. During drum rotation, this guides and compresses the approaching clothes, causing them to adhere tightly to the outer surfaces of the first and second side walls. A first detection circuit board is located on the inner side of the first side wall, and a second detection circuit board is located on the inner side of the second side wall. The electric field can penetrate the side walls; therefore, the clothes adhering to the outer surface of the side walls are directly in the capacitance detection electric field region, allowing for a more thorough understanding of the impact of humidity changes on capacitance, thus improving the accuracy of humidity measurement. Simultaneously, when the drum rotates in both directions, the clothes adhere to different side walls, ensuring reliable detection by both detection circuit boards and guaranteeing the accuracy of humidity measurement under various rotational directions. Attached Figure Description

[0017] Figure 1 A schematic diagram of a roller with humidity detection function provided by this utility model; Figure 2 A schematic diagram of an electrode plate with humidity detection function in a drum provided by this utility model on a first detection circuit board (the second detection circuit board is the same).

[0018] Icons: 1-Drum; 2-First sidewall; 3-Second sidewall; 4-Protruding wall; 5-First detection circuit board; 6-Second detection circuit board; 7-Electrode sheet. Detailed Implementation

[0019] To make the implementation process of this utility model clearer, a detailed description will be provided below in conjunction with the accompanying drawings.

[0020] This utility model provides a roller with humidity detection function, such as Figure 1As shown, a wedge-shaped closed cavity is provided on the inner wall of the roller 1. The cavity is formed by the inner wall of the roller 1, the first side wall 2, the second side wall 3, the protruding wall 4, the top wall, and the bottom wall. The proximal ends of the first side wall 2 and the second side wall 3 are fixedly disposed on the inner wall of the roller 1, and the distal ends of the first side wall 2 and the second side wall 3 are fixedly connected to the two ends of the protruding wall 4. The distance between the proximal ends of the first side wall 2 and the second side wall 3 is greater than the distance between the distal ends. The extension direction of the first side wall 2 and the second side wall 3 is along the radial direction of the roller 1, and the extension lengths of the first side wall 2 and the second side wall 3 are equal and both less than the radius of the roller 1. Specifically, the thickness of the first side wall 2 and the second side wall 3 is 0.3-0.8 mm, and the extension thickness is 20%-35% of the radius of the roller 1. They are fixed to the roller 1 by welding.

[0021] The protruding wall 4 is arc-shaped and protrudes towards the central axis of the roller 1. The thickness of the protruding wall 4 is 0.45-0.6mm, and it is formed by stamping with a stainless steel mold. The radius of the arc is 0.8-0.9 times the radius of the roller 1, and the height of the arc-shaped wall protruding towards the center of the roller 1 is 3-8mm. The arc shape of the protruding wall 4 and its protrusion towards the central axis of the roller 1 allow clothing near this area to slide more smoothly when the roller 1 rotates, preventing it from getting stuck at the corners. The arc surface also provides flexible support for the clothing, causing it to naturally bulge and adhere to the outer surface of the wedge-shaped cavity as it passes through, thus enhancing the fit between the clothing and the outer surface of the sidewall. Since the detection circuit board is located inside the sidewall and the electric field can penetrate the sidewall, the bulging and adhering surface of the clothing helps the electric field to more completely cover the clothing surface, improving the capacitance response to humidity changes and further enhancing the accuracy of humidity detection.

[0022] The cavity is cylindrical along the axis of rotation of roller 1, and its length is 1.1-1.2 times the length of the detection circuit board. The cylindrical structure makes the wedge-shaped cavity have a consistent cross-sectional shape in the axial direction of roller 1, which is beneficial for the clothing to obtain the same adhesion conditions throughout the entire axial range. The cylindrical cavity keeps the distance between the electrode plate and the clothing and the electric field distribution consistent, improving the uniformity of humidity detection.

[0023] A detection circuit board is installed on the inner surface of the cavity, and the outer surface of the cavity contacts the working space of the roller 1. A first detection circuit board 5 is fixedly installed on the inner side of the first sidewall 2, and a second detection circuit board 6 is fixedly installed on the inner side of the second sidewall 3. Electrode plates 7 are provided on both the first and second detection circuit boards 5 and 6. The number of electrode plates 7 is greater than or equal to two, and planar capacitance is formed between the electrode plates 7. The arrangement direction of the multiple electrode plates 7 is parallel to the roller axis direction. Figure 2As shown. At least one electrode in electrode plate 7 is an excitation electrode, and one is a receiving electrode; the others can be either excitation electrodes or receiving electrodes. The excitation electrode is connected to an excitation circuit, and the receiving electrode is connected to a receiving circuit. The two circuits and how they are powered are existing technologies and are not specifically limited; for example, a built-in battery can be used to power the circuit and electrode plate 7, or a wireless module and an external wireless power supply can be used. By observing the signal change at the receiving electrode, the capacitance change between the parallel capacitors can be obtained, which indicates the humidity change, thus enabling humidity detection. Metal interconnects are also provided on the detection circuit board for connecting the circuits.

[0024] Furthermore, the electrode 7 is positioned near the sidewall, and is bonded to the sidewall with insulating adhesive. This minimizes the thickness of the sidewall that the electric field needs to penetrate, reduces energy loss, and makes the change in dielectric constant caused by clothing humidity easier to detect, increasing the capacitance change amplitude and thus improving sensitivity. The arrangement direction of the two electrode 7 is parallel to the roller axis of the roller 1, and the distance between the two electrode 7 is greater than 3mm to avoid mutual interference between the electric fields, thereby expanding the electric field distribution space. The two electrode 7 form a planar capacitor, and their arrangement direction is parallel to the axis of the roller 1, resulting in a stable electric field distribution in the sidewall thickness direction and higher electric field penetration efficiency. The parallel arrangement also avoids electric field disturbances caused by the tangential movement of the clothing, making the capacitance change more stable and improving the humidity detection accuracy. Preferably, the two electrode 7 have the same shape and size, with a length of 3-8cm and a width of 0.5-2.5cm. The length direction can be set along the radius direction of the roller 1, such as... Figure 2 As shown, the two electrode plates 7 have a larger length in the opposite direction, which can form an electric field with a greater penetration depth between them. The penetration depth refers to the propagation depth of the electric field after passing through the side wall, which means that the humidity inside the clothing can be detected.

[0025] The area on the first sidewall 2 where the first detection circuit board 5 is located, and the area on the second sidewall 3 where the second detection circuit board 6 is located, are equipped with non-metallic transmission windows. These non-metallic materials can transmit electric fields; examples include plastics, ceramics, rubber, and glass. To better maintain stability, glass or ceramic can be used, as these materials are relatively hard and not easily deformed. The other areas of the first and second sidewalls 2 and 3, as well as the protruding wall 4, are made of rigid materials, which can be either metallic or non-metallic, such as stainless steel, glass, modified polypropylene (LFT-PP), galvanized steel sheet, etc. The transmission windows are fixed to the surrounding materials using slots, spot-welded frames, or adhesives. The window size must be greater than or equal to the size of the detection circuit board. The low dielectric constant of the transmission window allows the electric field to penetrate the area more easily and act on the clothing, thereby improving the sensitivity of capacitance measurement. Using stainless steel in the remaining areas helps maintain the cavity's strength and prevent deformation.

[0026] Furthermore, to prevent deformation of the cavity, the edges of the first sidewall 2 and the second sidewall 3 are bent outwards towards the cavity at a 90° angle. The bent portion is arc-shaped and fits snugly against the inner wall of the roller 1, with a length of 6-10mm. The outer edge of the flange is fixed to the inner wall of the roller 1 by stainless steel spot welding or riveting, with the weld points spaced 10-20mm axially to ensure a firm and reliable connection. The flange structure not only increases the contact area between the sidewall and the roller 1 but also improves the bending and torsional stiffness of the sidewall, preventing the wedge-shaped cavity from deforming due to high-speed rotation or impact from clothing.

[0027] In use, the capacitors on the first detection circuit board 5 and the second detection circuit board 6 can be detected individually or in parallel. Preferably, the emitting electrode on the first detection circuit board 5 and the emitting electrode on the second detection circuit board 6 are connected, and the receiving electrode on the first detection circuit board 5 and the receiving electrode on the second detection circuit board 6 are connected. Parallel connection increases the equivalent capacitance, amplifying the capacitance change caused by humidity variations, which is equivalent to increasing the sensing area and improving overall sensitivity. After parallel connection, both circuit boards can provide information in both forward and reverse rotation, making the measurement results more stable, avoiding the influence of random adhesion on a single board, and improving detection consistency. In this application, the roller refers only to the cylindrical body. As an accessory, it needs to be installed in a washing machine or dryer. The roller needs to be fixedly connected to the rotating chassis shaft, which is a conventional setting for washing machines or dryers and is existing technology. In addition, during cascade detection, the electrode plates 7 on the first detection circuit board 5 and the second detection circuit board 6 can form an electrode plate array for time-division measurement, thereby realizing multi-channel detection function.

[0028] The excitation and receiving circuits in this application can adopt existing capacitance detection circuit structures. Preferably, they are disposed on the first detection circuit board 5 and the second detection circuit board 6. They can be integrated on the detection circuit boards or electrically connected to the main control board via ribbon cables; no specific limitation is made. The excitation circuit consists of an oscillator or a signal generation module, used to output an AC excitation signal of a certain frequency and amplitude to the transmitting electrode. The humidity of the clothing causes the signal amplitude, phase, or oscillation frequency on the receiving electrode to change with the capacitance. The receiving circuit can use a capacitor-to-voltage converter, capacitor-to-frequency converter, or capacitor-to-digital converter chip to amplify, shape, and demodulate the signal from the receiving electrode, and output the voltage value, frequency value, or digital quantity corresponding to the capacitance change to the control chip. The control chip calculates the humidity state of the clothing according to a preset algorithm. The above-mentioned excitation signal type, frequency range, and specific implementation method of the receiving circuit are all well-known technologies in the art, and this application does not limit them.

[0029] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A roller with humidity detection function, wherein a cavity is provided on the inner wall of the roller, a detection circuit board is provided on the inner surface of the cavity, and the outer surface of the cavity is in contact with the working space of the roller, characterized in that, The cavity is a wedge-shaped closed chamber, which is formed by the inner wall of the roller, a first side wall, a second side wall, a protruding wall, a top wall, and a bottom wall. The proximal ends of the first side wall and the second side wall are fixedly disposed on the inner wall of the roller, and the distal ends of the first side wall and the second side wall are fixedly connected to the two ends of the protruding wall. The distance between the proximal ends of the first side wall and the second side wall is greater than the distance between the distal ends. A first detection circuit board is fixedly disposed on the inner side of the first side wall, and a second detection circuit board is fixedly disposed on the inner side of the second side wall.

2. The roller with humidity detection function according to claim 1, characterized in that, The first sidewall and the second sidewall extend in the radial direction of the roller, and the lengths of the first sidewall and the second sidewall are equal and both are less than the radius of the roller.

3. The roller with humidity detection function according to claim 2, characterized in that, The protruding wall is arc-shaped and protrudes towards the central axis of the roller.

4. The roller with humidity detection function according to claim 3, characterized in that, Both the first detection circuit board and the second detection circuit board are provided with electrode plates, the number of which is greater than or equal to 2, and a planar capacitor is formed between the electrode plates. The arrangement direction of the plurality of electrode plates is parallel to the roller axis direction of the roller.

5. The roller with humidity detection function according to claim 4, characterized in that, The electrode sheet is disposed near the first sidewall and the second sidewall.

6. The roller with humidity detection function according to claim 5, characterized in that, The edges of the first sidewall and the second sidewall are bent outwards from the cavity and welded or riveted to the inner wall of the roller through the bending structure.

7. The roller with humidity detection function according to claim 6, characterized in that, The cavity is cylindrical along the axis of rotation of the roller.

8. The roller with humidity detection function according to any one of claims 1-7, characterized in that, A transmission window is provided on both the first sidewall and the second sidewall. The transmission window is made of a non-metallic material and is located in the area where the first detection circuit board and the second detection circuit board are fixedly installed on the inside.

9. The roller with humidity detection function according to claim 8, characterized in that, The capacitors on the first detection circuit board and the second detection circuit board are connected in parallel for detection. The transmitting electrode on the first detection circuit board and the transmitting electrode on the second detection circuit board are connected. The receiving electrode on the first detection circuit board and the receiving electrode on the second detection circuit board are connected.

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