A machine-harvested tea leaf grading device

Abstract

The application discloses a kind of machine-picked tea green leaf grading device, including box, fan unit, conveying mechanism and screening mechanism;The box is divided into upper structure and lower structure, and the top of upper structure is provided with feeding port;The fan unit is arranged in the side of upper structure;The conveying mechanism is arranged in the bottom of upper structure;The screening mechanism is arranged in lower structure;One side of the conveying mechanism is provided with a first discharge port, and the other side of the conveying mechanism is provided with a feeding port for communicating between upper structure and lower structure;The screening mechanism includes a plurality of screening drums arranged inside lower structure for screening different grades of tea green leaf, and the plurality of screening drums are arranged downward in a zigzag manner;The side of lower structure is provided with different grades of discharge port at the position corresponding to each screening drum.The device can quickly separate different grades of tea green leaf after picking by tea picker, lay a foundation for subsequent processing, improve the efficiency of tea green leaf grading, and save manpower.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, specifically to a machine-harvested tea leaf grading device. Background Technology

[0002] Tea leaves refer to the fresh, tender leaves picked from tea trees, used as the raw material for processing into dried tea (finished tea). The selection of tea leaves is crucial to the quality of tea and is one of the important factors affecting the tea's grading. For example, the standard for picking premium Tieguanyin tea is one bud and two leaves, while the standard for green tea and black tea is the bud tip, and so on. With the modernization and large-scale development of the tea industry, tea picking is currently mainly done by tea-picking machines, using a "one-cut" operation. Due to the different growth stages of tea leaves, the quality of tea leaves picked by tea-picking machines is inconsistent, often containing fragmented buds and leaves, old stems, and old leaves, which is not conducive to uniform processing, affects the final quality of the tea, and makes manual grading difficult. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned problems and provide a machine-harvested tea leaf grading device. After the tea leaves are harvested by the tea harvesting machine, the device can quickly separate tea leaves of different grades, laying the foundation for subsequent processing, improving the efficiency of tea leaf grading, and saving manpower.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A machine-harvested tea leaf grading device includes a housing, a fan unit, a conveying mechanism, and a screening mechanism. The housing is divided into an upper structure and a lower structure. The upper structure has a feeding port at its top. The fan unit is located on the side of the upper structure. The conveying mechanism is located at the bottom of the upper structure. The screening mechanism is located in the lower structure. One side of the conveying mechanism has a primary discharge port, and the other side has a feed port connecting the upper and lower structures. The screening mechanism includes multiple screening rollers arranged in a serrated downward orientation inside the lower structure for screening different grades of tea leaves. Different grade discharge ports are located on the side of the lower structure corresponding to each screening roller.

[0006] The working principle of the above-mentioned machine-harvested tea leaf grading device is as follows:

[0007] The screening drums, blower unit, and conveyor mechanism start operating, piling the machine-picked tea leaves onto the feeding port and letting them fall into the upper structure. The blower unit blows air onto the falling tea leaves, performing preliminary grading. Larger tea leaves, such as those with stems and branches, enter the primary discharge port and are collected. The remaining tea leaves fall onto the conveyor mechanism, which transports them towards the feeding port. The tea leaves on the conveyor mechanism fall horizontally from the feeding port into the lower structure. Under the influence of gravity, they are graded and screened by multiple screening drums. The graded tea leaves are collected in the corresponding discharge ports of each screening drum, while the remaining tea leaves fall to the bottom of the box (lower structure) and are collected.

[0008] In a preferred embodiment of the present invention, the screening rollers are equipped with sieve tubes, and the spacing between the sieve tubes on each screening roller is different. The purpose is to enable multi-stage screening of tea leaves.

[0009] Furthermore, the spacing between the screen tubes on each screening roller decreases sequentially from top to bottom. In the above structure, from top to bottom, the spacing between the screen tubes on the screening rollers becomes smaller and smaller. Tea leaves falling from the feed inlet will enter the highest screening roller. Larger tea leaves will be blocked by the screen tubes on the screening roller and will not fall downwards. The tea leaves that do not fall will fall into the corresponding discharge outlet and be collected as the screening roller rotates. Smaller tea leaves will pass through the highest screening roller and enter the second highest screening roller below the highest screening roller for the next level of grading and screening, and so on.

[0010] Preferably, the screening roller is driven by a motor to achieve its rotational motion accompanied by vibration. The combination of vibration and rotation of the screening roller by the motor improves the screening effect of the tea leaves, prevents the tea leaves from piling up, and the vibration disperses any stacked tea leaves, thus improving the quality of machine-harvested tea leaves during grading.

[0011] Preferably, when the screening roller is working, each sieve tube on the screening roller maintains a constant rotational motion, causing the tea leaves on both sides of the screening roller to gather towards the center. This is to prevent the tea leaves from falling off the sides of the screening roller, allowing them to adhere better to the sieve tubes. The tea leaves gathered in the center of the screening roller can then pass through the screening roller more effectively. Simultaneously, the rotation of the sieve tubes allows for better grading of the tea leaves using the spacing between the tubes, ensuring the accuracy of the tea leaf grading.

[0012] Preferably, a baffle is provided above the conveying mechanism. By setting the baffle, when the machine-harvested tea leaves fall from the feeding port, and the blower unit blows air onto the falling tea leaves, most of the tea leaves will move away from the primary discharge port under the action of the airflow. After being blocked by the baffle, the tea leaves can fall onto the conveying mechanism.

[0013] Preferably, a herringbone-shaped guide plate is provided between the screening drum and its corresponding discharge port. By setting the herringbone-shaped guide plate, the tea leaves that have not fallen (the tea leaves adhering to the screen tube of the screening drum) will fall to one side of the herringbone-shaped guide plate as the screening drum rotates. Guided by the herringbone-shaped guide plate, the tea leaves slide down to the corresponding discharge port for collection. The tea leaves that fall down through the screening drum will be guided by the other side of the herringbone-shaped guide plate and enter the next stage screening drum for screening and grading.

[0014] Preferably, the number of screening rollers is three, which are divided into a primary screening roller, a secondary screening roller, and a tertiary screening roller from top to bottom. The discharge ports corresponding to the primary, secondary, and tertiary screening rollers are the secondary discharge port, the tertiary discharge port, and the quaternary discharge port, respectively. A fifth discharge port is provided at the bottom of the box. This fifth discharge port is located below the lowest screening roller (the tertiary screening roller) and is used to collect the tea leaves that fall after passing through the lowest screening roller.

[0015] Preferably, a camera is installed at the top of the lower structure (bottom of the upper structure); industrial identification cameras are also installed at the primary, secondary, tertiary, quaternary, and quinary discharge ports. The cameras are specifically installed next to the conveying mechanism to observe the accumulation and grading speed of the tea leaves entering the lower structure via the conveying mechanism. Simultaneously, the industrial identification cameras at each discharge port detect the appearance quality grade of the tea leaves and calculate the grading accuracy at each discharge port. The rotation speed of the conveying mechanism and each screening roller can then be controlled via a human-machine interface.

[0016] Preferably, the machine-harvested tea leaf grading device further includes a control system, which controls the rotational speed of the conveying mechanism, the fan unit, and each screening roller. The control system enables automated control, improving grading efficiency and quality.

[0017] Preferably, the fifth-stage discharge port is equipped with a near-infrared tea leaf inclusion detection device. Using this structure, the graded tea leaves can be graded in one pass, ensuring the overall grading quality of machine-harvested tea leaves.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The machine-harvested tea leaf grading device of the present invention uses a blower unit to perform air separation and purification of tea leaves, followed by screening and grading through multiple screening rollers. Different grades of tea leaves can be obtained from the discharge ports of each screening roller. The operation is simple and convenient, and different grades of tea leaves can be quickly separated. This is beneficial for preliminary screening and grading of different grades of tea leaves before tea processing, laying the foundation for subsequent processing, improving the efficiency of machine-harvested tea leaf grading, and saving manpower.

[0020] 2. In the preferred embodiment of the present invention, by setting up a herringbone-shaped flow guide plate and observing the accumulation of tea leaves during grading through a camera, the rotation speed of the conveying mechanism, the fan unit, and each screening roller is controlled to reduce mechanical damage during tea leaf grading and improve the quality of grading, thereby increasing the economic benefits of tea leaves. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the first embodiment of a machine-harvested tea leaf grading device according to the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of the screening roller and the herringbone-shaped guide plate in this invention.

[0023] Figure 3 This is a schematic diagram of the structure of one row of screen tubes in this invention. Detailed Implementation

[0024] To enable those skilled in the art to fully understand the technical solutions of the present invention, the present invention will be further described below in conjunction with embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0025] Example 1

[0026] See Figure 1 This embodiment discloses a machine-harvested tea leaf grading device, including a housing 1, a fan unit 18, a conveying mechanism 15, and a screening mechanism. The housing 1 is divided into an upper structure and a lower structure. The upper structure of the housing 1 has a feeding port 19 at its top. The fan unit 18 is located on the side of the upper structure of the housing 1. The conveying mechanism 15 is located at the bottom of the upper structure of the housing 1. The screening mechanism is located in the lower structure of the housing 1. One side of the conveying mechanism 15 has a primary discharge port 14, and the other side has a feed port connecting the upper and lower structures. The screening mechanism includes multiple screening rollers 4, 13, and 7 arranged inside the lower structure of the housing 1 for screening tea leaves of different grades. The multiple screening rollers 4, 13, and 7 are arranged downwards in a serrated pattern. The side of the lower structure has discharge ports 5, 12, and 8 of different grades at positions corresponding to each screening roller 4, 13, and 7.

[0027] Multiple screening rollers are arranged downwards in a zigzag pattern, meaning they are divided into two rows with staggered arrangement. The connecting line between the multiple screening rollers from top to bottom forms a zigzag line, with each screening roller located at the inflection point of the zigzag line. In this embodiment, there are three screening rollers, with two rollers in one row and one roller in the other row.

[0028] See Figure 1 In this embodiment, the machine-harvested tea leaf grading device performs preliminary purification of the tea leaves through the air separation of the conveying mechanism 15, removing old stems and rotten leaves and changing the falling shape of the tea leaves. The conveying mechanism 15 then ensures that the preliminarily purified tea leaves are evenly fed into the grading area of ​​the lower structure. Due to the different spacing of the sieve tubes 6 on the screening rollers 4, 13, and 7, tea leaves of different grades will adhere to the sieve tubes 6 of the screening rollers. As the rollers rotate, they will fall into the collection basket outside the feeding port 19. Therefore, tea leaves of different grades can be collected simultaneously, improving grading efficiency.

[0029] See Figure 1 and Figure 3 The screening rollers 4, 13, and 7 are equipped with sieve tubes 6, and the spacing between the sieve tubes 6 on each screening roller is different. The purpose is to achieve multi-stage screening of tea leaves.

[0030] See Figure 1 The feeding port 19 is a Y-shaped feeding port. By setting the feeding port to Y, the tea leaves can be better gathered and guided into the upper structure. In this embodiment, there are three screening rollers. The movement of the three screening rollers 4, 13, and 7 is controlled by motors. According to the different spacing of the screen tubes 6 on the screening rollers, the three screening rollers 4, 13, and 7 are divided into a first-stage screening roller 4, a second-stage screening roller 13, and a third-stage screening roller 12 from top to bottom. The discharge ports 5, 12, and 8 corresponding to the first-stage screening roller 4, the second-stage screening roller 13, and the third-stage screening roller 12 are the second-stage discharge port 5, the third-stage discharge port 12, and the fourth-stage discharge port 8, respectively.

[0031] See Figure 1The spacing of the screen tubes 6 on each of the screening rollers 4, 13, and 7 decreases sequentially from top to bottom. Specifically, the spacing of the screen tubes 6 on the first-stage screening roller 4 is greater than that on the second-stage screening roller 13, and the spacing of the screen tubes 6 on the second-stage screening roller 13 is greater than that on the third-stage screening roller 12. In the above structure, the spacing of the screen tubes 6 on the screening rollers becomes smaller from top to bottom. Tea leaves falling from the inlet will enter the highest screening roller (first-stage screening roller 4). Larger tea leaves will be blocked by the screen tubes 6 on the screening roller (first-stage screening roller 4) and will not fall downwards. The tea leaves that do not fall will fall into the corresponding outlet (second-stage outlet 5) and be collected as the screening roller (first-stage screening roller 4) rotates. Smaller tea leaves will pass through the highest screening roller and enter the second highest screening roller (second-stage screening roller 13) below the highest screening roller (second-stage outlet 5) for the next stage of grading and screening, and so on.

[0032] See Figures 1-3 Each screening drum has multiple rows of screen tubes, which are evenly distributed along the circumference. Each row of screen tubes includes multiple screen tubes 6, which are arranged along the axis of the screening drum. The spacing between the screen tubes 6 is the distance between two adjacent screen tubes 6 in each row.

[0033] See Figures 1-3 The screening rollers 4, 13, and 7 are rotated by motors.

[0034] See 1- Figure 2 The rotation directions of two adjacent screening rollers are opposite. Each screening roller (4, 13, 7) rotates downwards towards its corresponding discharge port (5, 12, 8). The specific directions are as follows: Figure 2 As shown.

[0035] See 1- Figure 3 When the screening rollers are working, each sieve tube 6 on the screening rollers 4, 13, and 7 maintains a constant rotational motion, causing the tea leaves on both sides of the screening rollers to gather towards the center. This is to prevent the tea leaves from falling off the sides of the screening rollers, allowing them to adhere better to the sieve tubes 6. The tea leaves gathered in the center of the screening rollers can then pass through the screening rollers more effectively. Simultaneously, the rotation of the sieve tubes 6 allows for better grading of the tea leaves using the spacing between the tubes, ensuring the accuracy of the tea leaf grading.

[0036] See 1- Figure 3 Each row of sieve tubes is divided into two parts, and the two parts rotate in opposite directions. For details on the rotation direction, please refer to [link / reference needed]. Figure 3Each row of screen tubes has 30 screen tubes 6, with 15 screen tubes in one part and 15 screen tubes in another part. The two parts of screen tubes are arranged symmetrically. The purpose is that when the screen tubes 6 in each row of screen tubes rotate, they can cause the tea leaves on both sides of the screening drum to gather towards the middle.

[0037] See 1- Figure 3 A baffle 17 is provided above the conveying mechanism 15. By setting the baffle 17, when the machine-picked tea leaves fall from the feeding port 19, and the blower unit 18 blows air on the falling tea leaves, most of the tea leaves will move away from the primary discharge port 14 under the action of the wind force. After being blocked by the baffle 17, the tea leaves can fall onto the conveying mechanism 15.

[0038] See 1- Figure 2 A herringbone-shaped guide plate 9 is provided between the screening rollers 4, 13, 7 and their corresponding discharge ports 5, 12, 8. By setting the herringbone-shaped guide plate 9, any tea leaves that have not fallen (tea leaves adhering to the screen tubes 6 of the screening rollers) will fall to one side of the herringbone-shaped guide plate 9 as the screening rollers rotate. Guided by the herringbone-shaped guide plate 9, the tea leaves will slide onto the corresponding discharge port and fall into the collection basket under gravity for collection. Tea leaves falling through the screening rollers will be guided by the other side of the herringbone-shaped guide plate 9 into the next stage of screening rollers for further screening and grading. The herringbone-shaped guide plate 9 collects tea leaves at each stage, allowing any uncollected tea leaves to better proceed to the next stage.

[0039] See 1- Figure 2 The herringbone-shaped guide plate 9 includes a first inclined plate and a second inclined plate; the first inclined plate extends downwards at an incline towards the discharge port, and the second inclined plate extends downwards at an incline towards the screening drum. Tea leaves adhering to the screen tube 6 of the screening drum fall onto the first inclined plate as the screening drum rolls, and then fall from the discharge port into the collection basket under gravity. Another portion of the tea leaves passing through the screen tube 6 of the screening drum falls onto the second inclined plate and then down to the next stage screening drum 4.

[0040] See Figure 1 The bottom of the housing 1 is provided with a five-stage discharge port 10. The five-stage discharge port 10 is located below the lowest screening roller (three-stage screening roller 12) and is used to collect the tea leaves that fall down after passing through the lowest screening roller.

[0041] See Figure 1A camera 3 is installed at the top of the lower structure (bottom of the upper structure); industrial recognition cameras 15 are installed on the primary discharge port 14, secondary discharge port 5, tertiary discharge port 12, quaternary discharge port 8, and quinary discharge port 10. The camera 3 is specifically installed next to the conveyor mechanism 15. Through the camera 3, the accumulation of tea leaves entering the lower structure via the conveyor mechanism 15 and the grading speed are observed. Simultaneously, through the various discharge ports and the industrial recognition cameras 15 positioned at each discharge port, image recognition combined with deep learning methods are used to detect the appearance quality grade of the tea leaves, and the grading accuracy of the tea leaves at each discharge port is statistically calculated. Then, the rotation speed of the conveyor mechanism 15 and the various screening rollers 4, 13, and 7 can be controlled through the human-machine interface 2.

[0042] See Figure 1 The machine-harvested tea leaf grading device also includes a control system, which controls the rotational speed of the conveying mechanism 15, the fan unit 18, and each screening roller 4, 13, and 7. The control system enables automated control, improving grading efficiency and quality.

[0043] See Figure 1 The fifth-stage discharge port 10 is equipped with a near-infrared tea leaf inclusion detection device. Using this structure, the graded tea leaves can be graded once, ensuring the overall quality of the machine-harvested tea leaves. Specifically, the quality of the tea leaves collected at the fifth-stage discharge port 10 is detected to determine the overall quality of the tea leaves and conduct a preliminary grading assessment.

[0044] See Figure 1 The fan unit 18 includes a fan, and the conveying mechanism 15 includes a conveyor belt.

[0045] See Figure 1 The housing 1 is provided with a horizontal partition plate. Between the horizontal partition plate and the primary discharge port 14, there is a guide plate that is inclined downward toward the primary discharge port 14. The feeding port 19 is located directly above the guide plate. The horizontal partition plate and the guide plate divide the housing 1 into an upper structure and a lower structure. The feeding port is set on the horizontal partition plate to connect the upper structure and the lower structure. The conveyor belt is located between the feeding port and the guide plate. The baffle 17 is set on the side of the feeding port near the conveyor belt. A vertical partition plate is set on the other side of the feeding port. The vertical partition plate, the horizontal partition plate and the upper structure form an installation space that can be used to install the hardware equipment of the control system.

[0046] See Figure 1 The working principle of the above-mentioned machine-harvested tea leaf grading device is as follows:

[0047] In this embodiment, when grading machine-harvested tea leaves, the operator first sets the initial rotation speed of each level of screening rollers, fans, and conveyor belts through the human-machine interface 2. Then, the machine-harvested tea leaves are piled up at the feeding port 19 and fall into the upper structure. The fans blow air onto the falling tea leaves, and the initial action of the fans performs preliminary grading. Tea leaves with larger stems and branches enter the primary discharge port 14 and are collected through the primary discharge port 14. The remaining tea leaves fall onto the conveyor belt under the action of the baffle 17. The conveyor belt transports the tea leaves towards the feeding port, and the tea leaves on the conveyor belt fall from the feeding port to the lower structure in a relatively horizontal manner. The tea leaves are screened by the screening mechanism. Under the action of gravity, the tea leaves fall onto the screen tube 6 on the side of the primary screening drum 4 away from the secondary discharge port 5. The tea leaves that do not fall (adhering to the screen tube 6) fall onto the side of the herringbone guide plate 9 near the secondary discharge port 5 as the primary screening drum 4 rotates, and are collected through the secondary discharge port 5 under the action of gravity. Other tea leaves will pass through the gaps in the screen tube 6 on the primary screening drum 4 and fall to the next primary screening drum 4 (secondary screening drum 13) for grading. After three screening drum gradings, some uncollected tea leaves fall to the fifth discharge port 10 and are then detected by a near-infrared tea leaf content detection device to perform a preliminary grading of the overall tea leaves.

[0048] Example 2

[0049] See Figure 1 In this embodiment, the other structures are the same as in embodiment 1, except that the screening rollers 4, 13, and 7 are rotated by a motor accompanied by slight vibrations. The combination of vibration and rotation of the screening rollers by the motor improves the screening effect of the tea leaves, prevents the tea leaves from piling up, and the vibration can disperse the piled tea leaves, thus improving the quality of machine-harvested tea leaves during grading.

[0050] To achieve minute vibrations in screening rollers 4, 13, and 7, the control system can be programmed using a PLC (Programmable Logic Controller) or controlled by a microcontroller. The motor can rotate forward for 2 seconds, then reverse for 1 second, and so on, thus achieving minute vibrations in screening rollers 4, 13, and 7, and consequently, achieving rotational motion of screening rollers 4, 13, and 7 accompanied by minute vibrations.

[0051] Example 3

[0052] In this embodiment, a vibrator can be set to drive the screening rollers 4, 13, and 7 to vibrate slightly, and a motor can be used to drive the screening rollers 4, 13, and 7 to rotate. The vibrator and the motor work together to achieve the vibration and rotation of the screening rollers 4, 13, and 7.

[0053] The above are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A device for grading machine-harvested tea leaves, characterized in that, The device includes a housing, a fan unit, a conveying mechanism, and a screening mechanism. The housing is divided into an upper structure and a lower structure. The upper structure has a feeding port at its top. The fan unit is located on the side of the upper structure. The conveying mechanism is located at the bottom of the upper structure. The screening mechanism is located in the lower structure. One side of the conveying mechanism has a primary discharge port, and the other side has a feed port connecting the upper and lower structures. The screening mechanism includes multiple screening rollers arranged in a serrated downward pattern inside the lower structure for screening different grades of tea leaves. Different grades of discharge ports are located on the sides of the lower structure corresponding to each screening roller. The screening rollers are equipped with screen tubes, and the spacing between the screen tubes on each screening roller is different; the spacing between the screen tubes on each screening roller decreases from top to bottom. When the screening drum is working, each sieve tube on the screening drum is constantly rotating, causing the tea leaves on both sides of the screening drum to gather towards the middle. Each screening drum is equipped with multiple rows of screen tubes, which are evenly distributed along the circumference. Each row of screen tubes is divided into two parts, and the two parts rotate in opposite directions.

2. The machine-harvested tea leaf grading device according to claim 1, characterized in that, The screening drum is driven by a motor to achieve its rotational motion accompanied by vibration.

3. The machine-harvested tea leaf grading device according to claim 1, characterized in that, A baffle is provided above the conveying mechanism.

4. The machine-harvested tea leaf grading device according to claim 1, characterized in that, A herringbone-shaped guide plate is provided between the screening drum and its corresponding discharge port.

5. The machine-harvested tea leaf grading device according to claim 1, characterized in that, The number of screening rollers is three, and the three screening rollers are divided into a primary screening roller, a secondary screening roller and a tertiary screening roller from top to bottom. The discharge ports corresponding to the primary screening roller, the secondary screening roller and the tertiary screening roller are the secondary discharge port, the tertiary discharge port and the quaternary discharge port, respectively. The bottom of the box is provided with a quinary discharge port.

6. The machine-harvested tea leaf grading device according to claim 5, characterized in that, A camera is installed on the top of the lower structure; industrial identification cameras are installed on the first-level, second-level, third-level, fourth-level, and fifth-level discharge ports.

7. A machine-harvested tea leaf grading device according to claim 1, characterized in that, The machine-harvested tea leaf grading device also includes a control system, which controls the rotational speed of the conveying mechanism, the fan unit, and each screening roller.

8. A machine-harvested tea leaf grading device according to claim 5, characterized in that, The fifth-stage discharge port is equipped with a near-infrared tea leaf content detection device.

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