A grain dryness detecting device for a grain dryer

Abstract

This invention discloses a grain dryness detection device for a grain dryer, relating to the field of humidity detection technology. To address accuracy issues, it specifically includes a detection unit and a control unit mounted on the outer wall of an exhaust duct. The detection unit comprises a detection housing fixed to the outer wall of the exhaust duct and a main shaft rotatably connected to the inner wall of the detection housing. Multiple fan plates are fixed to the outer wall of the main shaft. Based on multiple humidity-sensitive resistors, this invention utilizes fluid force to sequentially contact the resistors with the fluid, thereby calculating humidity using the average value. This prevents humidity calculation errors caused by single or localized humidity-sensitive resistor errors, increasing humidity detection accuracy. Furthermore, the humidity calculation logic uses an error amplitude k to select whether to discard data collected by the humidity-sensitive resistors, thus eliminating erroneous data collected under abnormal operating conditions of the humidity-sensitive resistors, further increasing humidity detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of humidity detection technology, and in particular to a grain dryness detection device for use in grain dryers. Background Technology

[0002] To prevent grains from sprouting, becoming infested with insects, or getting moldy during storage, they need to be dried after harvesting. During the drying process, the dryness of the grains needs to be tested to prevent energy waste from over-drying and under-drying.

[0003] A search revealed Chinese Patent Publication No. CN205844310U, which discloses a drying detection device for a grain dryer. The device includes a support body, a connector, a protective box, a first power supply, a wireless transmission module, a wireless switch module, a processor, a moisture detector, a humidity sensor, a data monitor, a display screen, a wireless receiving module, a wireless switch, and a second power supply. The support body is a right-angled U-shape. A connector for connecting to a grain drying box is provided on the support body. A protective box is provided on the support body, containing the power supply, the wireless transmission module, and the processor. A moisture detector and a humidity sensor are provided on the support body. The wireless transmission module, processor, moisture detector, and humidity sensor are electrically connected to the first power supply. The wireless transmission module is electrically connected to the processor. The moisture detector and humidity sensor are electrically connected to the processor.

[0004] The aforementioned patent has the following shortcomings: it uses a simple humidity sensor for humidity detection, but the accuracy of the final detection is affected by the characteristics of the built-in humidity-sensitive resistor and the usage status during the detection process. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a grain dryness detection device for grain dryers.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A grain dryness detection device for a grain dryer includes a detection unit and a control unit installed on the outer wall of an exhaust duct.

[0008] The detection unit includes a detection housing fixed to the outer wall of the exhaust duct and a main shaft rotatably connected to the inner wall of the detection housing. Multiple fan plates are fixed to the outer wall of the main shaft, and a humidity-sensitive resistor is fixed to the other end of the fan plate.

[0009] The control unit includes a control housing fixed to the outer wall of the exhaust duct and a processing controller and a storage battery fixed to the inner wall of the control housing. The discharge terminal of the storage battery is electrically connected to a voltage regulator for converting different voltage outputs of the storage battery into a fixed voltage output. The output terminal of the voltage regulator is electrically connected to multiple humidity-sensitive resistors, and the multiple humidity-sensitive resistors are connected in parallel. Each humidity-sensitive resistor is connected in series with an ammeter, and the ammeter is communicatively connected to the processing controller.

[0010] Preferably, the processing controller has a built-in humidity determination logic, which includes the following steps:

[0011] S1: Error setting, setting the accuracy error range k, which is positively correlated with the error of the humidity sensor; assuming that under the same humidity, the resistance of the humidity sensor is between R1 and R2, then the error range of the humidity sensor k = |R1 - R2|

[0012] S2: Data acquisition and processing. The controller acquires the current of the ammeter connected in series with each humidity-sensitive resistor and calculates the resistance value of the humidity-sensitive resistor based on the current value and the output voltage U of the voltage regulator.

[0013] S3: Data processing, for the i-th humidity sensor, if... This indicates a fault in the i-th humidity sensor. Discard the data for the i-th humidity sensor, and then proceed according to... Based on the final measured resistance value of the humidity sensor, if Then the data for the i-th humidity sensor is correct, and then according to... The final measured resistance value of the humidity sensor, where R i To calculate the resistance value of the i-th humidity sensor, The sum of all resistance values ​​of n humidity-sensitive resistors;

[0014] S4: Humidity calculation. Based on the final measured resistance value of the humidity sensor, and the humidity value corresponding to the resistance value of the humidity sensor, the humidity is calculated.

[0015] Furthermore, the control unit also includes a control module and a display module fixed to the outer wall of the control housing, and the control module and the display module are electrically connected to the processing controller.

[0016] Based on the aforementioned scheme: the detection unit further includes multiple contact rings and conductive contacts. The contact rings are in contact with the conductive contacts and are electrically conductive. At the same time, the humidity-sensitive resistor is connected to the output terminal of the voltage regulator through the contact rings and conductive contacts. An insulating frame is fixed to the outer wall of the main shaft. The conductive contacts are slidably connected to the side wall of the insulating frame, and the conductive contacts are connected to the inner wall of the insulating frame through a spring.

[0017] A preferred embodiment of the aforementioned scheme is that the detection unit further includes a power generation mechanism fixed to the outer wall of the exhaust duct and a switching mechanism for controlling the power generation mechanism.

[0018] As a further aspect of the present invention: the power generation mechanism includes a power generation housing fixed to the outer wall of the exhaust duct and a power generation shaft rotatably connected inside the power generation housing. The inner wall of the power generation housing is fixed with a stator winding, and the outer wall of the power generation shaft is drivenly connected with a rotor core that cooperates with the stator winding. The output terminal of the stator winding is connected to the charging terminal of the battery, and the power generation shaft is fixed to the end of the main shaft.

[0019] Meanwhile, the rotor core is rotatably connected to the outer wall of the generator shaft, and the inner wall of the generator shaft is axially slidably connected to a movable shaft. The side wall of the generator shaft is radially slidably connected to multiple pawls. The inner wall of the rotor core is provided with a ratchet groove that matches the pawls. The inner side of the pawls is rotatably connected to a connecting rod, and the other end of the connecting rod is rotatably connected to the outer wall of the movable shaft.

[0020] As a preferred embodiment of the present invention: a second spring is fastened to one end of the movable shaft, and the other end of the second spring is fastened to the inner wall of the generator shaft.

[0021] Meanwhile, the switching mechanism includes a permanent magnet, an electromagnet, and an insulating plate. The insulating plate is fixed to the outer wall of the exhaust duct by bolts. The permanent magnet and the electromagnet are arranged opposite each other, and the electromagnet is fixed to the side wall of the insulating plate. The permanent magnet is fixed to the end of the movable shaft by an end plate. The magnetic poles of the permanent magnet and the electromagnet are opposite on opposite sides. The input terminal of the electromagnet is electrically connected to the output terminal of the battery.

[0022] As a preferred embodiment of the present invention: a sliding plate is slidably connected to the inner wall of the generator shaft, an arc-head limiting block is fixed to the outer wall of the sliding plate, the other side of the sliding plate is connected to the inner wall of the generator shaft by a spring, and the outer wall of the movable shaft is provided with two sets of limiting grooves that cooperate with the arc-head limiting block. When the arc-head limiting block cooperates with one set of limiting grooves, the pawl and the groove are in an engaged state. When the arc-head limiting block cooperates with the other set of limiting grooves, the pawl and the groove are in a non-engaged state.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. This invention, based on setting multiple humidity-sensitive resistors, utilizes fluid force to cause the multiple humidity-sensitive resistors to sequentially contact the fluid, thereby enabling the calculation of humidity using the average value. This prevents humidity calculation errors caused by the error of a single or local humidity-sensitive resistor, increasing the accuracy of humidity detection. At the same time, in the humidity calculation logic, the error amplitude k is used to select whether to discard the data collected by the humidity-sensitive resistors, thereby eliminating erroneous data collected by the humidity-sensitive resistors under abnormal operating conditions, further increasing the accuracy of humidity detection.

[0025] 2. This invention, by providing a contact ring and a conductive contact, utilizes the electrical conductivity of the contact ring and the conductive contact and their relative rotation to compensate for the rotational movement between the humidity-sensitive resistor, the voltage regulator, and the ammeter, thereby preventing wire entanglement. At the same time, by providing a spring, it can ensure reliable contact between the contact ring and the conductive contact, and also compensate for wear, thus increasing reliability.

[0026] 3. In this invention, based on the self-powered battery, a power generation mechanism is added. This allows the main shaft to rotate during testing, driving the rotor core to rotate. The stator windings then charge the battery, enabling long-term battery operation. Simultaneously, the energy originates from the main shaft's own rotation during testing, thus achieving a certain degree of energy recovery.

[0027] 4. Based on the self-charging setting, this invention switches the charging and non-charging states of the battery by utilizing the change in the field strength of the electromagnet, thereby ensuring that the battery has a reliable amount of power and preventing overcharging damage. In addition, by utilizing the correlation between the battery capacity and the output voltage, the electromagnet is connected to the battery, thereby realizing automatic control with self-sensing and self-drive, without the need for manual or electronic control algorithm intervention, increasing the convenience of use.

[0028] 5. In this invention, by setting an arc-head limiting block, the movable shaft will move instantaneously only when the sum of the forces exerted on the movable shaft by the second spring, the electromagnet, and the permanent magnet is greater than the limiting resistance of the arc-head limiting block and the limiting slot. Thus, the two limiting slots reliably limit the two positions of the movable shaft, increasing the reliability of state control and preventing wear in the "semi-engaged" state. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of a grain dryness detection device for a grain dryer proposed in this invention.

[0030] Figure 2 This is a schematic diagram of the internal structure of the detection housing of a grain dryness detection device for a grain dryer proposed in this invention;

[0031] Figure 3 This is a schematic diagram of the internal structure of the control housing of a grain dryness detection device for a grain dryer proposed in this invention;

[0032] Figure 4 This is a schematic diagram of the contact ring and conductive contact position structure of a grain dryness detection device for a grain dryer proposed in this invention.

[0033] Figure 5This is a schematic diagram showing the position and structure of the switching mechanism and power generation mechanism of a grain dryness detection device for a grain dryer proposed in this invention;

[0034] Figure 6 This is a schematic diagram of the internal structure of the power generation housing of a grain dryness detection device for a grain dryer proposed in this invention.

[0035] Figure 7 This is a partial cross-sectional view of the power generation mechanism of a grain dryness detection device for a grain dryer proposed in this invention.

[0036] Figure 8 This is a schematic diagram of the full cross-sectional structure of the power generation mechanism of a grain dryness detection device for a grain dryer proposed in this invention;

[0037] Figure 9 This is a schematic diagram of the switching mechanism of a grain dryness detection device for a grain dryer proposed in this invention.

[0038] Figure 10 This is a schematic diagram of the circuit structure of a grain dryness detection device for a grain dryer proposed in this invention;

[0039] Figure 11 This is a process architecture diagram of a grain dryer for a grain dryer, as proposed in this invention, which is a grain dryness detection device for a grain dryer.

[0040] In the diagram: 1. Exhaust duct; 2. Detection unit; 3. Control unit; 4. Detection housing; 5. Main shaft; 6. Fan plate; 7. Humidity-sensitive resistor; 8. Control housing; 9. Control module; 10. Display module; 11. Processing controller; 12. Battery; 13. Contact ring; 14. Conductive contact; 15. Spring 1; 16. Switching mechanism; 17. Generator mechanism; 18. Stator winding; 19. Generator housing; 20. Rotor core; 21. Generator shaft; 22. Pawl; 23. Connecting rod; 24. Movable shaft; 25. Spring 2; 26. Ratchet; 27. Spring 3; 28. Slide plate; 29. ​​Arc head limit block; 30. Limiting slot; 31. End plate; 32. Permanent magnet; 33. Electromagnet; 34. Insulating plate; 35. Insulating frame. Detailed Implementation

[0041] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0042] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0043] Figure 11 The type of grain drying tower used in this embodiment is related to the dryness of the grain and the humidity of the air outlet of the drying section. Specifically, the higher the humidity of the air outlet, the lower the dryness of the grain. Therefore, this device is specifically installed at the exhaust duct (1) of the grain drying tower.

[0044] Example 1:

[0045] A grain dryness detection device for a grain dryer, such as Figure 1 - Figure 10 As shown, it includes a detection unit 2 and a control unit 3 set on the outer wall of the exhaust duct 1. The detection unit 2 includes a detection housing 4 fixed to the outer wall of the exhaust duct 1 and a main shaft 5 rotatably connected to the inner wall of the detection housing 4. Multiple fan plates 6 are fixed on the outer wall of the main shaft 5, and a humidity-sensitive resistor 7 is fixed at the other end of the fan plate 6.

[0046] The control unit 3 includes a control housing 8 fixed to the outer wall of the exhaust duct 1, a processing controller 11 fixed to the inner wall of the control housing 8, and a storage battery 12. The discharge terminal of the storage battery 12 is electrically connected to a voltage regulator for converting different voltage outputs of the storage battery 12 into a fixed voltage output. The output terminal of the voltage regulator is electrically connected to multiple humidity-sensitive resistors 7, and the multiple humidity-sensitive resistors 7 are connected in parallel. Each humidity-sensitive resistor 7 is connected in series with an ammeter, and the ammeter is communicatively connected to the processing controller 11.

[0047] The processing controller 11 has built-in humidity determination logic, which includes the following steps:

[0048] S1: Error setting, setting the accuracy error range k, which is positively correlated with the error of the humidity sensor 7; assuming that under the same humidity, the resistance of the humidity sensor 7 is between R1 and R2, then the error range k of the humidity sensor 7 = |R1 - R2|

[0049] S2: Data acquisition and processing controller 11 acquires the current of the ammeter connected in series with each humidity-sensitive resistor 7, and calculates the resistance value of the humidity-sensitive resistor 7 based on the current value and the output voltage U of the voltage regulator.

[0050] S3: Data processing, for the i-th humidity sensor 7, if... This indicates a fault in the i-th humidity sensor 7. Discard the data for the i-th humidity sensor 7, and then proceed according to... Based on the final measured resistance value of the humidity-sensitive resistor 7, if Then the data for the i-th humidity sensor is correct, and then according to... The final measured resistance value of the humidity sensor 7, where R i To calculate the resistance value of the i-th humidity sensor 7, The sum of all resistance values ​​of n humidity-sensitive resistors 7;

[0051] S4: Humidity calculation. Based on the final measured resistance value of the humidity sensor 7, and the humidity value corresponding to the resistance value of the humidity sensor 7, calculate the humidity.

[0052] In use, as the exhaust duct 1 exhausts air, the fan plate 6 and the humidity-sensitive resistor 7 will move and rotate under the action of the fluid, so that multiple humidity-sensitive resistors 7 will continuously come into contact with the air in the exhaust duct 1, thereby generating a resistance value corresponding to the humidity in the humidity-sensitive resistor 7, causing the ammeter to generate a corresponding current value, and then calculating the humidity of the fluid in the exhaust duct 1 based on the magnitude of the current value, thereby determining the dryness of the grain.

[0053] This device, based on multiple humidity-sensitive resistors 7, utilizes fluid force to sequentially bring the multiple humidity-sensitive resistors 7 into contact with the fluid, thereby calculating humidity using the average value. This prevents humidity calculation errors caused by the error of a single or local humidity-sensitive resistor 7, increasing the accuracy of humidity detection. At the same time, in the humidity calculation logic, the error amplitude k is used to select whether to discard the data collected by the humidity-sensitive resistors 7, thereby eliminating erroneous data collected by the humidity-sensitive resistors 7 under abnormal operating conditions, further increasing the accuracy of humidity detection.

[0054] To solve display and control problems; such as Figure 3 As shown, the control unit 3 also includes a control module 9 and a display module 10 fixed to the outer wall of the control housing 8, and the control module 9 and the display module 10 are electrically connected to the processing controller 11.

[0055] It can be displayed through the display module 10 and operated through the control module 9.

[0056] To solve connectivity problems; such as Figure 4 As shown, the detection unit 2 also includes multiple contact rings 13 and conductive contacts 14. The contact rings 13 and conductive contacts 14 are in contact and electrically connected. At the same time, the humidity-sensitive resistor 7 is connected to the output terminal of the voltage regulator through the contact rings 13 and conductive contacts 14. Specifically, the number of groups of contact rings 13 and conductive contacts 14 is twice the number of groups of humidity-sensitive resistors 7. For a humidity-sensitive resistor 7, one end is connected to a conductive contact 14, and the contact ring 13 that cooperates with the conductive contact 14 is connected to the voltage regulator. The other end of the humidity-sensitive resistor 7 is connected to another conductive contact 14, and the contact ring 13 that cooperates with the conductive contact 14 is connected to a galvanometer. The galvanometer is then connected to the output terminal of the voltage regulator. Since the connection of parallel and series circuits is conventional knowledge for those skilled in the art, this embodiment will not elaborate on it.

[0057] An insulating frame 35 is fixed to the outer wall of the main shaft 5. The conductive contact 14 is slidably connected to the side wall of the insulating frame 35, and the conductive contact 14 is connected to the inner wall of the insulating frame 35 by a spring 15.

[0058] Since the humidity-sensitive resistor 7 is a rotating component, while the voltage regulator and battery 12 are fixed components, direct use of wires for the conductive connection between them would result in tangling. However, this device, by setting up a contact ring 13 and a conductive contact 14, utilizes the electrical conductivity between the contact ring 13 and the conductive contact 14 and their relative rotation to compensate for the rotational movement between the humidity-sensitive resistor 7 and the voltage regulator and ammeter, thereby preventing wire tangling. At the same time, by setting up a spring 15, it can ensure reliable contact between the contact ring 13 and the conductive contact 14 on the one hand, and also compensate for wear on the other hand, increasing reliability.

[0059] In this embodiment, during use, as air is exhausted from the exhaust duct 1, the fan plate 6 and the humidity-sensitive resistor 7 move and rotate under the force of the fluid. This causes multiple humidity-sensitive resistors 7 to continuously contact the air in the exhaust duct 1, resulting in a resistance value corresponding to the humidity of the humidity-sensitive resistor 7. This causes the ammeter to generate a corresponding current value, and the humidity of the fluid in the exhaust duct 1 is calculated based on the magnitude of the current value to determine the dryness of the grain. Since the humidity-sensitive resistor 7 is a rotating component, while the voltage regulator and battery 12 are fixed components, direct use of wires for the conductive connection between them would result in tangling. However, this device, by setting up a contact ring 13 and a conductive contact 14, utilizes the electrical conductivity of the contact ring 13 and the relative rotation of the conductive contact 14 to compensate for the rotational movement between the humidity-sensitive resistor 7 and the voltage regulator and ammeter, thereby preventing wire tangling. At the same time, by setting up a spring 15, it can ensure reliable contact between the contact ring 13 and the conductive contact 14 on the one hand, and compensate for wear on the other hand, increasing reliability.

[0060] Example 2:

[0061] A grain dryness detection device for a grain dryer, such as Figure 1 - Figure 10 As shown, since the entire device is located outside the exhaust duct 1, and the exhaust duct 1 itself has no electrical components and no circuit, but the device needs to use electricity, in order to solve the self-powered problem, this embodiment makes the following improvements based on embodiment 1: the detection unit 2 also includes a power generation mechanism 17 fixed to the outer wall of the exhaust duct 1 and a switching mechanism 16 for controlling the power generation mechanism 17.

[0062] The power generation mechanism 17 includes a power generation housing 19 fixed to the outer wall of the exhaust duct 1 and a power generation shaft 21 rotatably connected inside the power generation housing 19. A stator winding 18 is fixed to the inner wall of the power generation housing 19, and a rotor core 20 that cooperates with the stator winding 18 is drivenly connected to the outer wall of the power generation shaft 21. The output terminal of the stator winding 18 is connected to the charging terminal of the battery 12, and the power generation shaft 21 is fixed to the end of the main shaft 5.

[0063] During humidity detection, the main shaft 5 rotates synchronously with the fan plate 6 and the humidity-sensitive resistor 7, thereby driving the generator shaft 21 to rotate. The generator shaft 21 drives the rotor core 20 to rotate, thereby generating an induced electromotive force in the stator winding 18. The induced electromotive force is then applied to the charging terminal of the battery 12 to charge the battery 12.

[0064] This device, based on the self-powered battery 12, adds a power generation mechanism 17, which can use the characteristic that the main shaft 5 needs to rotate during detection to drive the rotor core 20 to rotate, thereby charging the battery 12 through the stator winding 18, thus achieving long-term operation of the battery 12. At the same time, its energy comes from its own rotation during detection, thus achieving a certain degree of energy recovery.

[0065] To solve the problems of automated control of the charging process, such as... Figure 5-9 As shown, the rotor core 20 is rotatably connected to the outer wall of the generator shaft 21, and the inner wall of the generator shaft 21 is axially slidably connected to a movable shaft 24. The side wall of the generator shaft 21 is radially slidably connected to multiple pawls 22. The inner wall of the rotor core 20 is provided with a ratchet groove 26 that matches the pawl 22. The inner side of the pawl 22 is rotatably connected to a connecting rod 23, and the other end of the connecting rod 23 is rotatably connected to the outer wall of the movable shaft 24.

[0066] A second spring 25 is fastened to one end of the movable shaft 24, and the other end of the second spring 25 is fastened to the inner wall of the generator shaft 21.

[0067] The switching mechanism 16 includes a permanent magnet 32, an electromagnet 33, and an insulating plate 34. The insulating plate 34 is fixed to the outer wall of the exhaust duct 1 by bolts. The permanent magnet 32 ​​and the electromagnet 33 are arranged opposite each other, and the electromagnet 33 is fixed to the side wall of the insulating plate 34. The permanent magnet 32 ​​is fixed to the end of the movable shaft 24 by an end plate 31. The magnetic poles of the permanent magnet 32 ​​and the electromagnet 33 are opposite on opposite sides.

[0068] The input terminal of the electromagnet 33 is electrically connected to the output terminal of the battery 12.

[0069] As the current stored capacity of the battery 12 decreases, its output voltage also decreases, which in turn reduces the field strength of the electromagnet 33. This reduces the magnetic attraction between the electromagnet 33 and the permanent magnet 32 ​​until it reaches a threshold. At this point, the movable shaft 24 is pulled inward by the spring 25, which pushes the pawl 22 outward through the connecting rod 23, causing the pawl 22 to engage with the ratchet groove 26. The rotor core 20 and the generator shaft 21 are then driven, and the battery 12 is in a charging state. As the battery 12 gradually charges, its output voltage gradually increases, which increases the field strength of the electromagnet 33 until it reaches the rated capacity of the battery 12. Then, the magnetic attraction between the electromagnet 33 and the permanent magnet 32 ​​overcomes the pulling force of the spring 25, causing the movable shaft 24 to move in the opposite direction. This pulls the pawl 22 inward using the connecting rod 23, causing the rotor core 20 and the generator shaft 21 to stop driving, and the battery 12 is disconnected from the charging state.

[0070] This device, based on its self-charging capability, switches between charging and non-charging states of the battery 12 by utilizing the change in field strength of the electromagnet 33. This ensures that the battery 12 has a reliable amount of charge while preventing overcharging damage. Furthermore, by utilizing the correlation between the battery 12's capacity and its output voltage, and connecting the electromagnet 33 to the battery 12, it achieves self-sensing and self-driven automated control without the need for manual intervention or electronic control algorithms, thus increasing ease of use.

[0071] To address the reliability of state transitions, such as Figure 8 As shown, a sliding plate 28 is slidably connected to the inner wall of the generator shaft 21, and an arc-shaped limiting block 29 is fixed to the outer wall of the sliding plate 28. The other side of the sliding plate 28 is connected to the inner wall of the generator shaft 21 by a spring 27. The outer wall of the movable shaft 24 is provided with two sets of limiting grooves 30 that cooperate with the arc-shaped limiting block 29. When the arc-shaped limiting block 29 cooperates with one set of limiting grooves 30, the pawl 22 and the ratchet groove 26 are in an engaged state. When the arc-shaped limiting block 29 cooperates with the other set of limiting grooves 30, the pawl 22 and the ratchet groove 26 are in a non-engaged state.

[0072] Since the position of the movable shaft 24 is controlled by the combination of spring 25 and magnetic force, the position of the movable shaft 24 is a continuous change process. This may cause the pawl 22 and the ratchet groove 26 to reach a critical contact state. This critical contact "partial engagement" state will cause wear and also make the state control of whether the battery 12 is charging or not inaccurate. In this device, by setting the arc head limit block 29, the movable shaft 24 will only move instantaneously when the sum of the forces exerted by spring 25, electromagnet 33 and permanent magnet 32 ​​on the movable shaft 24 is greater than the limiting resistance of the arc head limit block 29 and the limiting groove 30. Thus, the two limiting grooves 30 are used to reliably limit the two positions of the movable shaft 24, increasing the reliability of state control and preventing wear in the "partial engagement" state.

[0073] In this embodiment, during humidity detection, the main shaft 5 rotates synchronously with the fan plate 6 and the humidity-sensitive resistor 7, thereby driving the generator shaft 21 to rotate. The generator shaft 21 drives the rotor core 20 to rotate, thus generating an induced electromotive force in the stator winding 18. This induced electromotive force is then applied to the charging terminal of the battery 12 to charge it. Furthermore, as the current charge of the battery 12 decreases, its output voltage also decreases, thereby reducing the field strength of the electromagnet 33. As the magnetic attraction between electromagnet 33 and permanent magnet 32 ​​decreases until it reaches a threshold, the movable shaft 24 is pulled inward by spring 25, thereby pushing the pawl 22 outward through connecting rod 23, causing the pawl 22 to engage with the ratchet groove 26. The rotor core 20 and generator shaft 21 are then driven, and the battery 12 is in a charging state. As the battery 12 gradually charges, its output voltage gradually increases, thereby increasing the field strength of electromagnet 33 until it reaches the rated capacity of battery 12. The magnetic attraction of the permanent magnet 32 ​​overcomes the pulling force of the spring 25, causing the movable shaft 24 to move in the opposite direction. This, in turn, pulls the pawl 22 inward using the connecting rod 23, disengaging the rotor core 20 from the generator shaft 21 and disconnecting the battery 12 from charging. Simultaneously, because the position of the movable shaft 24 is controlled by the combination of the spring 25 and magnetic force, the position of the movable shaft 24 is a continuous change. This means that the pawl 22 and the ratchet groove 26 may reach a critical contact state—a "semi-engaged" state of critical contact. This would cause wear and tear and also make the charging status control of the battery 12 inaccurate. In this device, by setting an arc head limit block 29, the movable shaft 24 will only move instantaneously when the sum of the forces exerted by the spring 25, the electromagnet 33, and the permanent magnet 32 ​​on the movable shaft 24 is greater than the limiting resistance of the arc head limit block 29 and the limiting slot 30. Thus, the two limiting slots 30 are used to reliably limit the two positions of the movable shaft 24, increasing the reliability of status control and preventing wear in the "partial engagement" state.

[0074] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A grain dryness detection device for a grain dryer, comprising a detection unit (2) and a control unit (3) disposed on the outer wall of an exhaust duct (1), characterized in that, The detection unit (2) includes a detection housing (4) fixed to the outer wall of the exhaust duct (1) and a main shaft (5) rotatably connected to the inner wall of the detection housing (4). Multiple fan plates (6) are fixed to the outer wall of the main shaft (5), and a humidity-sensitive resistor (7) is fixed to the other end of the fan plate (6). The control unit (3) includes a control housing (8) fixed to the outer wall of the exhaust duct (1) and a processing controller (11) and a storage battery (12) fixed to the inner wall of the control housing (8). The discharge terminal of the storage battery (12) is electrically connected to a voltage regulator for converting different voltage outputs of the storage battery (12) into a fixed voltage output. The output terminal of the voltage regulator is electrically connected to multiple humidity-sensitive resistors (7), and the multiple humidity-sensitive resistors (7) are connected in parallel. Each humidity-sensitive resistor (7) is connected in series with an ammeter, and the ammeter is communicatively connected to the processing controller (11). The detection unit (2) also includes multiple contact rings (13) and conductive contacts (14). The contact rings (13) are in contact with the conductive contacts (14) and are electrically connected. At the same time, the humidity-sensitive resistor (7) is connected to the output terminal of the voltage regulator through the contact rings (13) and the conductive contacts (14). An insulating frame (35) is fixed on the outer wall of the main shaft (5). The conductive contacts (14) are slidably connected to the side wall of the insulating frame (35), and the conductive contacts (14) are connected to the inner wall of the insulating frame (35) through a spring (15). The detection unit (2) also includes a power generation mechanism (17) fixed to the outer wall of the exhaust duct (1) and a switching mechanism (16) for controlling the power generation mechanism (17). The power generation mechanism (17) includes a power generation housing (19) fixed to the outer wall of the exhaust duct (1) and a power generation shaft (21) rotatably connected inside the power generation housing (19). The inner wall of the power generation housing (19) is fixed with a stator winding (18), and the outer wall of the power generation shaft (21) is connected with a rotor core (20) that cooperates with the stator winding (18). The output terminal of the stator winding (18) is connected to the charging terminal of the storage battery (12), and the power generation shaft (21) is fixed to the end of the main shaft (5). The switching mechanism (16) includes a permanent magnet (32), an electromagnet (33), and an insulating plate (34). The insulating plate (34) is fixed to the outer wall of the exhaust duct (1) by bolts. The permanent magnet (32) and the electromagnet (33) are arranged opposite each other and the electromagnet (33) is fixed to the side wall of the insulating plate (34). The permanent magnet (32) is fixed to the end of the movable shaft (24) by an end plate (31). The magnetic poles of the permanent magnet (32) and the electromagnet (33) are opposite on opposite sides. The input terminal of the electromagnet (33) is electrically connected to the output terminal of the battery (12). The inner wall of the generator shaft (21) is slidably connected to a sliding plate (28), and the outer wall of the sliding plate (28) is fixed with an arc head limiting block (29). The other side of the sliding plate (28) is connected to the inner wall of the generator shaft (21) by a spring three (27). The outer wall of the movable shaft (24) is provided with two sets of limiting slots (30) that cooperate with the arc head limiting block (29). When the arc head limiting block (29) cooperates with one set of limiting slots (30), the pawl (22) and the ratchet groove (26) are in a biting state. When the arc head limiting block (29) cooperates with the other set of limiting slots (30), the pawl (22) and the ratchet groove (26) are in a non-biting state.

2. The grain dryness detection device for a grain dryer according to claim 1, characterized in that, The processing controller (11) has a built-in humidity determination logic, which includes the following steps: S1: Error setting, setting the accuracy error range k, k is positively correlated with the error of the humidity-sensitive resistor (7); S2: Data acquisition and processing controller (11) acquires the current of the ammeter connected in series with each humidity-sensitive resistor (7), and calculates the resistance of the humidity-sensitive resistor (7) based on the current and the output voltage U of the voltage regulator; S3: Data processing, for the i-th humidity sensor (7), if If , it indicates a fault in the i-th humidity sensor (7). Discard the data of the i-th humidity sensor (7), and then according to The calculated result is used as the final measured resistance value of the humidity-sensitive resistor (7). If the data of the i-th humidity sensor (7) is correct, then according to The calculated result is used as the final measured resistance value of the humidity-sensitive resistor (7), where To calculate the resistance value of the i-th humidity sensor (7), The sum of all resistance values ​​of n humidity-sensitive resistors (7); S4: Humidity calculation: Based on the final measured resistance value of the humidity-sensitive resistor (7), and the humidity value corresponding to the resistance value of the humidity-sensitive resistor (7), calculate the humidity.

3. The grain dryness detection device for a grain dryer according to claim 1, characterized in that, The control unit (3) further includes a control module (9) and a display module (10) fixed to the outer wall of the control housing (8), and the control module (9) and the display module (10) are electrically connected to the processing controller (11).

4. The grain dryness detection device for a grain dryer according to claim 1, characterized in that, The rotor core (20) is rotatably connected to the outer wall of the generator shaft (21), and the inner wall of the generator shaft (21) is axially slidably connected to a movable shaft (24). The side wall of the generator shaft (21) is radially slidably connected to multiple pawls (22). The inner wall of the rotor core (20) is provided with a ratchet groove (26) that matches the pawl (22). The inner side of the pawl (22) is rotatably connected to a connecting rod (23), and the other end of the connecting rod (23) is rotatably connected to the outer wall of the movable shaft (24).

5. A grain dryness detection device for a grain dryer according to claim 4, characterized in that, The end of the movable shaft (24) is fastened with a second spring (25), and the other end of the second spring (25) is fastened to the inner wall of the generator shaft (21).

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