A rubbing and twisting device for tea processing

Abstract

The application discloses a rubbing and twisting device for tea processing; the device comprises a rack, a rubbing and twisting cavity, a bionic rubbing and twisting mechanism, a dynamic pressure mechanism, an intelligent control system, a driving assembly and a discharging assembly. The inner wall of the rubbing and twisting cavity is provided with spiral arc flow guide ridges, and the bottom is eccentrically provided with a discharge port; the bionic rubbing and twisting mechanism comprises a central rotating shaft, an extendable rubbing and twisting arm and a food-grade silica gel flexible rubbing and twisting head, the bottom surface of the flexible rubbing and twisting head is an arc curved surface and is provided with rubbing and twisting convex points, and the rubbing and twisting head simulates the pushing, rubbing and rubbing composite action of manual rubbing and twisting; the dynamic pressure mechanism comprises a lifting cylinder, a pressure sensor and an elastic buffer assembly; the driving assembly adopts inner spline and outer spline sliding cooperation, which not only transmits rotation but also allows axial sliding. The application combines bionic flexible rubbing and twisting and dynamic self-adaptive pressure, improves the strip rate by more than 20% and reduces the broken tea rate by more than 15%, one machine is suitable for processing of multiple tea classes, and the intelligent and standardized operation of the rubbing and twisting process is realized.

Description

Technical Field

[0001] This invention relates to the field of tea processing machinery and equipment, specifically to a kneading device for tea processing, suitable for kneading various types of tea such as green tea, black tea, and oolong tea. Background Technology

[0002] Tea rolling is the core process in the initial processing of tea. Its function is to break down the cell structure of tea leaves, promote the outflow of tea juice, and make the tea leaves curl into strips. At the same time, it enhances the aroma and taste of tea, and directly determines the appearance and internal quality of the finished tea.

[0003] Currently, tea rolling equipment on the market has the following main defects: First, the rolling trajectory is simple, mostly just circular rotation, which cannot simulate the combined actions of rubbing, pressing, and pushing in manual rolling, resulting in low tea strip formation rate and loose tea strips; Second, the pressure method is rigid, mostly using fixed pressure, which cannot be dynamically adjusted with the rolling process, making tender leaves easy to crush and old leaves not thoroughly rolled, resulting in a high rate of broken tea; Third, the tea leaves are unevenly distributed in the rolling chamber, easily accumulating in some areas, resulting in poor consistency of quality in batch processing; Fourth, the level of intelligence is low, lacking real-time monitoring of parameters such as temperature and pressure, relying on manual experience for control, making it difficult to adapt to the differentiated processing needs of different types of tea.

[0004] To address the aforementioned issues, there is an urgent need to develop a tea processing kneading device that offers excellent kneading performance, low tea breakage rate, strong adaptability, and a high degree of automation. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing tea kneading equipment and provide a tea processing kneading device. It simulates the combined action of manual kneading through a biomimetic flexible kneading structure, achieves automatic pressure adjustment with the processing progress through a dynamic adaptive pressurization system, and realizes precise control and one-click switching of processing parameters for multiple tea types through an intelligent control system. This improves the tea strip yield, reduces the broken tea rate, and realizes intelligent and standardized operation of the kneading process.

[0006] An innovative tea processing kneading device includes a frame, a kneading chamber, a biomimetic kneading mechanism, a dynamic pressure mechanism, an intelligent control system, a drive component, and a discharge component.

[0007] The frame is constructed from welded stainless steel profiles, serving as the overall support for the device. The bottom of the frame is equipped with anti-slip pads and casters for easy securing and transport of the equipment.

[0008] The kneading chamber is a detachable cylindrical structure made of food-grade stainless steel. The inner wall of the chamber is uniformly decorated with arc-shaped guide ridges along its circumference. Each arc-shaped guide ridge extends spirally from the upper part of the inner wall downwards, guiding the tea leaves to circulate and tumble within the chamber, preventing localized accumulation. A detachable kneading disc is located at the bottom of the chamber, with a flexible, non-slip texture on its surface. A through-hole for the central rotating shaft to pass through is located in the center of the kneading disc. An inlet is located on the upper part of the side wall of the chamber, connected to a feeding hopper. An outlet is located at an eccentric position at the bottom of the chamber (i.e., there is a horizontal distance between the center of the outlet and the central axis of the kneading chamber) to avoid interference between the outlet and the central rotating shaft. Several discharge holes are also provided on the kneading disc for the seepage of tea juice during kneading and for the discharge of tea leaves after kneading.

[0009] The biomimetic kneading mechanism is located inside the kneading cavity and includes a central rotating shaft, biomimetic kneading arms, and a flexible kneading head. The central rotating shaft is vertically positioned on the central axis of the kneading cavity, with its upper end connected to the dynamic pressure mechanism and its lower end connected to the drive assembly. Multiple biomimetic kneading arms (4-8 in total) are radially and evenly distributed around the outer circumference of the central rotating shaft. Each biomimetic kneading arm is a telescopic structure, consisting of an outer sleeve and an inner sliding rod. The inner sliding rod slides within the outer sleeve, and a return spring is provided between the outer sleeve and the inner sliding rod, allowing the kneading arm to adaptively adjust its length according to the thickness of the tea leaves, with a telescopic range of 20mm-50mm. A guide groove is formed along the axial direction on the outer sleeve, and a guide pin is provided on the inner sliding rod. The guide pin passes through the guide groove, extends outside the outer sleeve, and is fitted with a limiting nut to limit the telescopic stroke and prevent the inner sliding rod from dislodging. The flexible kneading head is connected to the end of the biomimetic kneading arm and is integrally molded from food-grade silicone material with a Shore A hardness of 30A-50A. The bottom surface of the flexible kneading head is an arc-shaped surface with a radius of curvature of 30mm to 60mm, simulating the arc of kneading by a human hand. Arc-shaped kneading bumps are evenly distributed on the bottom surface, with a bump height of 2mm to 5mm. The arc-shaped surface provides uniform pushing pressure, while the kneading bumps provide localized kneading force. The two work together to simulate the combined "pushing, kneading, and rubbing" motion of manual kneading.

[0010] The dynamic pressurization mechanism is located at the top of the kneading chamber and includes a support frame, a lifting cylinder, a pressure sensor, and an elastic buffer assembly. The support frame is fixedly installed at the top of the kneading chamber. The lifting cylinder is vertically mounted on the support frame, with its piston rod extending vertically downwards into the kneading chamber, its axis coinciding with the axis of the central rotating shaft. The lower end of the piston rod of the lifting cylinder is fixedly connected to the upper end (stationary end) of the thrust ball bearing via a coupling. The lower end (rotating end) of the thrust ball bearing is fixedly connected to the upper end of the pressure sensor via a first connecting flange. The lower end of the pressure sensor is fixedly connected to the top end of the central rotating shaft via a second connecting flange. The thrust ball bearing bears the axial load, transmitting the axial pressure generated by the lifting cylinder to the central rotating shaft, while allowing the central rotating shaft to rotate freely relative to the cylinder piston rod, thus isolating the axial pressurization from the rotational motion. The pressure sensor is located between the thrust ball bearing and the central rotating shaft, monitoring the kneading pressure in real time. A pressure sensor, specifically a spoke-type pressure sensor, is installed between the lower end of the piston rod of the lifting cylinder and the top of the central rotating shaft. Its upper end is fixedly connected to the lower end of the piston rod via a first connecting flange, and its lower end is fixedly connected to the top of the central rotating shaft via a second connecting flange. This sensor is used to detect the kneading pressure in real time and feed the signal back to the intelligent control system. An elastic buffer assembly is fitted around the central rotating shaft and includes an upper spring seat, a lower spring seat, and a buffer spring. The stiffness of the buffer spring is 50 N / mm to 200 N / mm, used to flexibly buffer the pressure and prevent sudden pressure changes from damaging the tea leaves.

[0011] The intelligent control system includes a touch screen display, a PLC controller, temperature sensors, speed sensors, and timers. The touch screen display, mounted on the side of the frame, is an industrial-grade touchscreen with built-in interfaces for parameter setting, operation monitoring, recipe management, and alarms. The PLC controller, housed in the frame's electrical control box, is the core control unit. Temperature sensors are installed on the inner wall of the kneading chamber to monitor kneading temperature in real time. The speed sensor is installed beside the central shaft to monitor its rotational speed in real time. All sensors and timers are electrically connected to the PLC controller. The PLC controller has built-in kneading parameter recipes for multiple tea varieties (including green tea, black tea, and oolong tea recipes), which can be accessed with a single touch on the touch screen. Simultaneously, the PLC controller performs PID closed-loop calculations on the pressure signals from the pressure sensors, automatically adjusting the output pressure of the lifting cylinder to achieve dynamic adaptive control of the kneading pressure.

[0012] The drive assembly includes a variable frequency drive motor and a transmission gear set. The variable frequency drive motor is mounted at the bottom of the frame and electrically connected to the frequency converter. The PLC controller adjusts the motor speed through the frequency converter, achieving stepless adjustment of the central shaft speed within the range of 10 rpm to 120 rpm. The transmission gear set includes a driving gear and a driven gear. The driving gear is fixedly mounted on the output shaft of the variable frequency drive motor. The driven gear is rotatably mounted on the frame via bearing housings, and its axial position is fixed. Specifically, a rolling bearing is fitted at both the upper and lower ends of the driven gear. The outer ring of the bearing is installed in the bearing housing, which is fixed to the frame by bolts. The bearing housing has a positioning step, and the axial position of the driven gear is limited and fixed by the bearings and the positioning step. The driven gear can only rotate freely around its axis and cannot move axially. The center hole of the driven gear has an internal spline, and the lower end of the central shaft has an external spline that mates with the internal spline. The central shaft slides through the center hole of the driven gear via the spline. During operation, the driven gear drives the central shaft to rotate synchronously via a spline, while the central shaft can slide freely axially within the driven gear. The variable frequency drive motor drives the central shaft to rotate after being reduced in speed by a transmission gear set. The central shaft then drives the bionic kneading arm to perform circular motion for kneading.

[0013] The discharge assembly is located at the discharge port and includes a baffle body, a miniature electric push rod, and a guide rail. The baffle body is slidably mounted on the guide rail. The push rod end of the miniature electric push rod is fixedly connected to the baffle body. The miniature electric push rod is electrically connected to a PLC controller, which controls the extension and retraction of the electric push rod to achieve automatic opening and closing of the discharge port. A discharge chute is connected below the discharge port.

[0014] Working Principle: Tea leaves are fed into the kneading chamber through the inlet. Kneading parameters (speed, pressure, time, etc.) for the corresponding tea type are preset on the touchscreen display. After starting the equipment, the variable frequency drive motor rotates the central shaft via a transmission gear set. The bionic kneading arm then performs a circular motion, and the flexible kneading head performs bionic kneading on the tea leaves (the curved surface provides pushing pressure, and the kneading protrusions provide rubbing). Simultaneously, the lifting cylinder applies axial pressure according to the preset parameters. The pressure is transmitted to the central shaft via a pressure sensor, and then to the flexible kneading head through the bionic kneading arm, acting on the tea leaves. The pressure sensor provides real-time pressure data, and the PLC controller automatically adjusts the output pressure of the lifting cylinder through PID calculations, achieving dynamic adaptive pressurization. During the kneading process, the curved guide protrusions on the inner wall of the chamber guide the tea leaves to circulate and tumble along a spiral trajectory, avoiding localized accumulation. After the preset time is reached, the PLC controller automatically stops the motor, raises the cylinder, and opens the outlet to complete the discharge.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. A biomimetic flexible kneading structure design significantly improves tea quality. This invention uses a flexible kneading head made of food-grade silicone, with an arc-shaped curved bottom surface and arc-shaped kneading protrusions to simulate the combined pushing and rubbing motions of the palm and fingers during manual kneading. Combined with a retractable biomimetic kneading arm, the length can be adaptively adjusted according to the thickness of the tea layer, ensuring the kneading head maintains appropriate contact pressure with the tea leaves at all times. Compared to traditional rigid kneading methods, this significantly reduces the rate of broken tea leaves, improves the tightness of the tea leaves and the uniformity of cell breakage, increases the tea leaf yield by more than 20%, and effectively improves the taste and aroma quality of the tea soup.

[0016] 2. Dynamic adaptive pressurization system solves the problem of rigid pressure in traditional equipment. This invention uses a pressure sensor to provide real-time feedback of kneading pressure data to a PLC controller. After PID closed-loop calculation, the PLC controller automatically adjusts the opening of the precision pressure reducing valve, achieving real-time dynamic adjustment of the output pressure of the lifting cylinder. This allows the kneading pressure to automatically change according to the softening degree of the tea leaves, adapting to the different stress requirements of tender and mature leaves. Combined with the flexible buffer component, it avoids damage to the tea leaves caused by sudden pressure changes, fundamentally solving the problems of rigid pressure, crushing tender leaves, and insufficient kneading of mature leaves in traditional equipment, further reducing the tea breakage rate.

[0017] 3. Intelligent and precise control system enables multi-functionality and standardized operation. This invention integrates multiple sensors, including pressure, temperature, and speed sensors, for real-time monitoring. Combined with PLC automatic control and PID closed-loop regulation technology, it achieves precise control of all parameters, including kneading speed, pressure, time, and temperature. The touch screen has a built-in multi-tea parameter formula library (green tea, black tea, oolong tea, etc.), allowing one-click switching to adapt to different tea processing methods. No manual experience is required for adjustment, achieving standardized operation of the kneading process. Simultaneously, the machine's multi-functionality significantly reduces equipment investment costs. Automated operation requires no real-time human supervision; kneading and output are integrated, increasing processing efficiency by 30% compared to traditional equipment.

[0018] 4. Uniformly distributed kneading chamber structure ensures consistent batch processing. The inner wall of the chamber features spiral-shaped, arc-shaped guide ridges, which, in conjunction with the rotating biomimetic kneading arms, force the tea leaves to circulate and tumble along a spiral trajectory within the chamber, forming a three-dimensional circulating flow path. This effectively prevents localized accumulation of tea leaves, ensuring that each tea leaf receives uniform force, significantly improving the quality consistency of tea leaves across batches during mass processing. The entire machine is constructed from food-grade stainless steel and silicone, and features a detachable chamber structure for easy cleaning and maintenance, meeting food processing hygiene standards. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the kneading device for tea processing according to the present invention; Figure 2 This is a schematic diagram of the structure of the bionic twisting arm of the present invention; Figure 3 This is a schematic diagram of the structure of the elastic buffer component of the present invention; Figure 4 This is a block diagram illustrating the control principle of the intelligent control system of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1-Frame, 11-Anti-slip feet, 12-Moving casters; 2- Kneading cavity, 21- Arc-shaped guide ridge, 22- Kneading disc, 23- Flexible anti-slip texture, 24- Feed inlet, 25- Discharge outlet; 3-Bionic kneading mechanism, 31-Central rotating shaft, 32-Bionic kneading arm, 321-Outer sleeve, 322-Inner slide rod, 323-Reset spring, 324-Guide groove, 325-Guide pin, 33-Flexible kneading head, 34-Kneading protrusion; 4-Dynamic pressurization mechanism, 41-Lifting cylinder, 42-Pressure sensor, 43-Elastic buffer assembly, 431-Upper spring seat, 432-Lower spring seat, 433-Buffer spring, 44-Support frame; 5-Intelligent control system, 51-Touch screen, 52-PLC controller, 53-Temperature sensor, 54-Speed ​​sensor, 55-Timer; 6-Drive assembly, 61-Variable frequency drive motor, 62-Transmission gear set; 7-Discharge assembly, 71-Baffle body, 72-Miniature electric push rod, 73-Discharge chute. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1 (Implementation of Basic Device Structure) like Figure 1-4 As shown, a tea processing kneading device includes a frame 1, a kneading cavity 2, a biomimetic kneading mechanism 3, a dynamic pressure mechanism 4, an intelligent control system 5, a drive component 6, and a discharge component 7.

[0023] The frame 1 is welded from 304 stainless steel profiles, with anti-slip pads 11 and moving rollers 12 installed at the four corners of the bottom. The kneading chamber 2 is a detachable cylindrical structure with an inner diameter of 500mm and a height of 400mm. The inner wall of the chamber has eight arc-shaped guide ridges 21, each 10mm high, with a spiral angle of 20°. A detachable kneading disc 22 is installed at the bottom of the chamber, with a wave-shaped flexible anti-slip texture 23 distributed on its surface. A feed inlet 24 is opened at the upper part of the side wall of the chamber (with an 80mm gap between the feed inlet 24 and the top of the chamber to avoid interference with the lifting cylinder 41), and a discharge outlet 25 is opened at an eccentric position at the bottom (the horizontal distance between the center of the discharge outlet 25 and the central axis of the kneading chamber is 100mm), ensuring that the discharge outlet 25 is not directly below the central rotating shaft 31.

[0024] like Figure 1-2 As shown, the bionic kneading mechanism 3 includes a central rotating shaft 31, six bionic kneading arms 32, and a flexible kneading head 33. The central rotating shaft 31 is vertically arranged and has a diameter of 30 mm. The six bionic kneading arms 32 are radially and evenly distributed around the outer circumference of the central rotating shaft, with adjacent arms at an angle of 60°. Each bionic kneading arm 32 consists of an outer sleeve 321 and an inner slide rod 322, forming a telescopic structure with a telescopic range of 30 mm. A return spring 323 with a spring stiffness of 20 N / mm is provided between the outer sleeve 321 and the inner slide rod 322. A guide groove 324 is provided on the outer sleeve 321, and a guide pin 325 is provided on the inner slide rod 322.

[0025] like Figure 2 As shown, the flexible kneading head 33 is connected to the end of the bionic kneading arm 32 and is integrally molded from food-grade silicone with a Shore A hardness of 40A. The bottom surface of the flexible kneading head is an arc-shaped curved surface with a radius of curvature of 45mm, and 12 arc-shaped kneading protrusions 34 are evenly distributed on the bottom surface, with a protrusion height of 3mm.

[0026] like Figure 1 and 3 As shown, the dynamic pressurization mechanism 4 is located at the top of the kneading chamber and includes a support frame 44, a lifting cylinder 41, a pressure sensor 42, and an elastic buffer assembly 43. The lifting cylinder 41 has a cylinder diameter of 63mm and a stroke of 100mm. The pressure sensor 42 is a spoke-type pressure sensor with a range of 500N. Its upper end is fixedly connected to the lower end of the piston rod of the lifting cylinder through a first connecting flange, and its lower end is fixedly connected to the top of the central rotating shaft 31 through a second connecting flange. The elastic buffer assembly 43 includes an upper spring seat 431, a lower spring seat 432, and a buffer spring 433. The stiffness of the buffer spring 433 is 100N / mm.

[0027] The intelligent control system 5 includes a touch screen display 51 (10-inch industrial touch screen), a PLC controller 52 (Siemens S7-1200), a temperature sensor 53 (PT100, installed on the inner wall of the kneading chamber), a speed sensor 54 (Hall effect type, installed beside the central shaft), and a timer 55 (integrated into the PLC controller). All sensors are electrically connected to the PLC controller, and the PLC controller and the touch screen display have a bidirectional communication connection.

[0028] The drive assembly 6 includes a variable frequency drive motor 61 (rated power 2.2kW) and a transmission gear set 62 (transmission ratio 3:1). The driven gear of the transmission gear set 62 has an internal spline in its central hole, and the lower end of the central shaft 31 has an external spline; the two are in sliding engagement. The central shaft 31 can be driven to rotate by the driven gear, and can also slide freely axially within the driven gear. The speed adjustment range is 10–120 rpm.

[0029] The discharge assembly 7 is located at the discharge port 25 and includes a baffle body 71, a miniature electric push rod 72, and a discharge chute 73. The baffle body is a 4mm thick circular plate made of 304 stainless steel and is slidably mounted on a guide rail. The miniature electric push rod has a stroke of 80mm, a thrust of 100N, and is electrically connected to the PLC controller. The discharge chute has an inclination angle of 45°.

[0030] Example 2 (Green Tea Rolling Processing) Take 30kg of fresh green tea leaves after fixation and put them into the kneading cavity 2 through the feed hopper and feed port 24. The amount of leaves added is about 60% of the cavity volume.

[0031] The operator enters the formula management interface through the touch screen 51, clicks the "Green Tea Formula" icon, and the PLC controller 52 automatically loads the green tea kneading parameters: kneading speed 50 rpm, kneading pressure 150 N, kneading time 25 min, and upper temperature limit 40 ℃.

[0032] After clicking the start button, the PLC controller 52 executes the following in sequence: the micro electric push rod 72 extends to close the discharge port 25; the precision pressure reducing valve sets the initial pressure value; the electromagnetic reversing valve controls the piston rod of the lifting cylinder 41 to extend; and the frequency converter controls the variable frequency drive motor 61 to start and accelerate to the set frequency of 50 rpm.

[0033] The central shaft 31 rotates (synchronously rotating within the spline hole of the driven gear while sliding freely axially), driving six biomimetic kneading arms 32 to perform circular motion. The curved surface and curved kneading protrusions 34 on the bottom of the flexible kneading head 33 apply a biomimetic kneading action to the fresh green tea leaves. When the tea layer is thick, the inner sliding rod 322 overcomes the elastic force of the return spring 323 and retracts into the outer tube 321, shortening the length of the kneading arm; when the tea layer becomes thin, the return spring pushes the inner sliding rod to extend, ensuring that the flexible kneading head always maintains appropriate contact with the tea leaves.

[0034] The lifting cylinder 41 applies a pressure of 150N, the pressure sensor 42 provides real-time feedback of the pressure value, and the PLC controller 52 automatically adjusts the opening of the precision pressure reducing valve through PID calculations to maintain a constant pressure. The arc-shaped guide rib 21 guides the tea leaves to circulate and tumble along a spiral trajectory. The temperature sensor 53 monitors the chamber temperature in real-time, and the speed sensor 54 monitors the rotation speed in real-time.

[0035] After the timer 55 accumulates 25 minutes, the PLC controller automatically stops the motor, raises the cylinder, and opens the discharge port. The kneaded green tea falls into the discharge collection chamber through the discharge hole on the kneading disc 22, is discharged through the eccentrically positioned discharge port 25, and then outputs through the discharge chute 73. Because the discharge port 25 is eccentrically positioned on one side of the central rotating shaft 31, the central rotating shaft 31 is not interfered with during the discharge process.

[0036] Actual testing showed that the green tea processed in this embodiment achieved a strip-forming rate of 92.3% and a broken tea rate of 1.2%, which is a significant improvement compared to traditional rolling equipment (strip-forming rate of about 72% and broken tea rate of about 4.5%).

[0037] Example 3 (Black Tea Rolling Processing) Take 25kg of withered fresh black tea leaves and put them into the kneading chamber 2 through the feed inlet. Retrieve the "black tea recipe" through the touch screen 51, and the PLC controller automatically loads the black tea kneading parameters: kneading speed 40rpm, kneading pressure set in segments (150N for the first stage 0-15min, 220N for the second stage 15-35min, and 300N for the third stage 35-50min), total kneading time 50min, and upper temperature limit 45℃.

[0038] After the equipment is started, the PLC controller controls the lifting cylinder 41 to operate according to the segmented pressurization program. In the first stage, when the pressure sensor 42 feedback value is 150N, the PLC maintains constant pressure; in the second stage, the PLC automatically adjusts the pressure setpoint to 220N, the opening of the precision pressure reducing valve increases, and the cylinder pressure rises; in the third stage, the pressure rises to 300N. The elastic buffer component 43 buffers the pressure change during each stage of pressure switching to avoid impact damage to the tea leaves.

[0039] During the rolling process, the required pressure changes as the fresh black tea leaves gradually soften. The segmented pressure design perfectly adapts to the "light-heavy-heavy" rolling process requirements of black tea. The arc-shaped guide ridge 21 guides the tea leaves to continuously circulate and tumble, ensuring even pressure distribution.

[0040] The material is automatically discharged after 50 minutes. Testing showed that in this embodiment, the black tea cell breakage rate reached 67.8%, the strip formation rate reached 89.5%, the broken tea rate was 1.8%, and the tea leaves were tightly rolled and uniform in color.

[0041] Example 4 (Oolong Tea Rolling Process) Take 20kg of fresh oolong tea leaves after processing and put them into the kneading chamber 2 through the feed inlet. Select the "Oolong Tea Formula" through the touch screen 51. The PLC controller automatically loads the oolong tea kneading parameters: kneading speed 30rpm, kneading pressure 100N, total kneading time 12min (using the "press 2min - release pressure 1min - press 2min" cycle mode, for a total of 4 cycles), and upper temperature limit 35℃.

[0042] After the equipment is started, the PLC controller controls the lifting cylinder 41 to operate in a "pressurization-release-pressurization" cycle. During the pressurization phase, the pressure is 100N. During the release phase, the piston rod of the lifting cylinder retracts slightly, and the pressure drops to 20N (maintaining only slight contact between the flexible kneading head and the tea leaves). Each cycle lasts 3 minutes, and a total of 4 cycles are performed. Because oolong tea requires "gentle kneading and slow twisting," the lower rotation speed (30rpm) and lower pressure (100N) combined with intermittent pressurization allow the tea leaves to maintain good integrity during the kneading process, while also causing moderate damage to the edges of the tea leaves and allowing the tea juice to slowly seep out.

[0043] The elastic buffer component 43 acts as a buffer during the switching between pressurization and depressurization, preventing sudden pressure changes from impacting the tea leaves. The arc-shaped guide ridge 21 keeps the tea leaves constantly turning, preventing prolonged localized pressure.

[0044] The tea is automatically discharged after 12 minutes. Testing showed that the oolong tea in this embodiment achieved a strip-forming rate of 90.1% and a broken tea rate of only 0.9%. The tea leaves were tightly rolled and had a glossy, oily appearance.

[0045] Example 5 (Verification of Pressure Adaptive Adjustment) To further verify the dynamic adaptive pressure effect of the present invention, 30 kg of the same batch of green tea was taken and kneaded using both traditional fixed pressure equipment and the device of the present invention.

[0046] Traditional fixed-pressure equipment has a constant pressure of 200N, which cannot be adjusted during the rolling process. In the early stages of rolling, the tea leaves have a high moisture content and are brittle, resulting in a broken tea rate as high as 5.2% due to the 200N pressure. In the later stages of rolling, the tea leaves have softened, and the 200N pressure is relatively insufficient, resulting in a strip formation rate of only 74.6%.

[0047] Using the device of this invention, the initial pressure of 200N and the kneading time of 25min are set via the touch display screen 51. During the kneading process, the pressure sensor 42 provides real-time feedback of pressure data. The PLC controller 52, according to a preset adaptive adjustment program, maintains a pressure of approximately 200N in the initial kneading stage (0-8min); in the middle stage (8-18min), based on the attenuation trend of the tea leaf's reaction force reported by the pressure sensor, it automatically increases the pressure gradually to approximately 240N via a precision pressure reducing valve; in the later stage (18-25min), when the tea leaves are fully softened, the PLC automatically fine-tunes the pressure to approximately 220N. Throughout the process, the pressure changes are stable, and the elastic buffer component 433 effectively absorbs vibration.

[0048] After the rolling process, the tea leaves processed by the device of this invention had a strip-forming rate of 93.1% and a broken tea rate of 1.1%. The comparative data fully demonstrates that the dynamic adaptive pressurization system of this invention can automatically adjust the pressure according to the rolling process of the tea leaves, significantly improving the rolling quality.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A kneading device for tea processing, characterized in that, It includes a frame (1), a kneading chamber (2), a bionic kneading mechanism (3), a dynamic pressurizing mechanism (4), an intelligent control system (5), a drive assembly (6), and a discharge assembly (7); The kneading cavity (2) is a cylindrical structure and is fixedly installed on the frame (1). The inner wall of the cavity is provided with an arc-shaped guide ridge (21), the bottom of the cavity is provided with a kneading disc (22), the side wall of the cavity is provided with a feed inlet (24), and the bottom of the cavity is provided with an outlet (25) at an eccentric position. The center of the outlet (25) and the center axis of the kneading cavity (2) are provided with a horizontal distance. The bionic kneading mechanism (3) is located inside the kneading cavity (2) and includes a central rotating shaft (31), a bionic kneading arm (32), and a flexible kneading head (33). The central rotating shaft (31) is connected to the drive assembly (6) for transmission. The bionic kneading arm (32) consists of multiple arms, which are evenly distributed radially around the outer periphery of the central rotating shaft (31). The bionic kneading arm (32) is a telescopic structure. The flexible kneading head (33) is connected to the end of the bionic kneading arm (32). The flexible kneading head (33) is made of food-grade silicone material, with an arc-shaped bottom surface and kneading protrusions (34) on the surface. The dynamic pressurization mechanism (4) is located at the top of the kneading chamber (2) and includes a lifting cylinder (41), a thrust ball bearing (46), a pressure sensor (42), and an elastic buffer assembly (43). The lower end of the piston rod of the lifting cylinder (41) is connected to the upper end of the pressure sensor (42) through the thrust ball bearing (46), and the lower end of the pressure sensor (42) is fixedly connected to the top end of the central rotating shaft (31). The thrust ball bearing (46) is used to transmit axial pressure while allowing relative rotation. The elastic buffer assembly (43) is sleeved on the outside of the central rotating shaft (31). The intelligent control system (5) includes a touch screen (51), a PLC controller (52), a temperature sensor (53), a speed sensor (54), and a timer (55); each sensor, timer (55), and touch screen (51) are electrically connected to the PLC controller (52); The drive assembly (6) includes a variable frequency drive motor (61) and a transmission gear set (62). The transmission gear set (62) includes a drive gear and a driven gear. The drive gear is fixedly mounted on the output shaft of the variable frequency drive motor (61). The driven gear is rotatably mounted on the frame (1) through a bearing seat and a rolling bearing and is fixed in axial position. The center hole of the driven gear is provided with an internal spline. The lower end of the central rotating shaft (31) is provided with an external spline that cooperates with the internal spline. The central rotating shaft (31) is slidably fitted through the spline and passes through the center hole of the driven gear. It can be driven to rotate by the driven gear and can also slide freely in the driven gear along the axial direction. The discharge assembly (7) is located at the discharge port (25) and is an electrically operated baffle.

2. The tea processing kneading device according to claim 1, characterized in that, The number of the bionic kneading arms (32) is 4 to 8. Each bionic kneading arm (32) consists of an outer tube (321) and an inner slide rod (322). The inner slide rod (322) is slidably sleeved inside the outer tube (321). A return spring (323) is provided between the outer tube (321) and the inner slide rod (322). The extension range is 20mm to 50mm. A guide groove (324) is provided on the outer tube (321). A guide pin (325) is provided on the inner slide rod (322). The guide pin (325) passes through the guide groove (324) and extends out of the outer tube (321) and is provided with a limiting nut.

3. The tea processing kneading device according to claim 1, characterized in that, The flexible kneading head (33) has a Shore hardness of 30A to 50A and a radius of curvature of 30mm to 60mm for the bottom arc surface; the kneading bumps (34) have a height of 2mm to 5mm, a bottom diameter of 3mm to 8mm, and a center distance of 5mm to 10mm between adjacent kneading bumps (34).

4. The tea processing kneading device according to claim 1, characterized in that, The elastic buffer assembly (43) is sleeved on the outside of the central rotating shaft (31), including an upper spring seat (431), a lower spring seat (432), and a buffer spring (433); the upper spring seat (431) is fixedly sleeved on the outer wall of the central rotating shaft (31) and moves synchronously with the central rotating shaft; the lower spring seat (432) is loosely sleeved on the outside of the central rotating shaft (31), and the lower spring seat is fixedly installed on the bearing seat at the top of the kneading cavity (2) by bolts, and the position remains stationary; the buffer spring (433) is sleeved on the outside of the central rotating shaft (31) and located between the upper spring seat (431) and the lower spring seat (432), with the upper end abutting the lower surface of the upper spring seat and the lower end abutting the upper surface of the lower spring seat; the stiffness of the buffer spring is 50N / mm to 200N / mm.

5. The tea processing kneading device according to claim 1, characterized in that, The number of the arc-shaped guide ridges (21) is 6 to 12, and they are evenly distributed along the circumferential direction of the inner wall of the kneading cavity (2). Each arc-shaped guide ridge (21) extends spirally from the upper part of the inner wall of the cavity to the lower part, with a spiral angle of 15° to 30°, a ridge height of 5mm to 15mm, and a width of 8mm to 20mm.

6. The tea processing kneading device according to claim 1, characterized in that, The kneading disc (22) is a detachable structure. The surface of the kneading disc (22) is covered with flexible anti-slip texture (23), which is a wave-shaped convex texture or a grid-shaped convex texture. The kneading disc (22) has several discharge holes with a diameter of 3mm to 8mm, which are arranged in a ring array.

7. The tea processing kneading device according to claim 1, characterized in that, The bottom of the frame (1) is provided with anti-slip pads (11) and moving rollers (12); after the variable frequency drive motor (61) is reduced by the transmission gear set (62), the speed adjustment range of the central rotating shaft (31) is 10rpm to 120rpm.

8. The tea processing kneading device according to claim 1, characterized in that, The PLC controller (52) has multiple kneading parameter formulas for various tea varieties, including green tea formula, black tea formula and oolong tea formula, which can be called with one key on the touch screen (51). The output terminal of the PLC controller (52) is electrically connected to the electromagnetic reversing valve and precision pressure reducing valve of the lifting cylinder (41), the frequency converter of the variable frequency drive motor (61), and the drive circuit of the electric opening and closing baffle.

9. The tea processing kneading device according to claim 1, characterized in that, The pressure sensor (42) is a spoke-type pressure sensor with a range of 0 to 500 N and an output signal of 4 to 20 mA current signal or 0 to 10 V voltage signal.

10. The tea processing kneading device according to claim 1, characterized in that, The discharge assembly (7) includes a baffle body (71), a micro electric push rod (72) and a guide rail. The baffle body (71) is slidably mounted on the guide rail. The push rod end of the micro electric push rod (72) is fixedly connected to the baffle body (71). The micro electric push rod (72) is electrically connected to the PLC controller (52). The kneading cavity (2) is composed of a cavity side wall and a cavity bottom. The cavity side wall and the cavity bottom are detachably connected by a flange and a sealing ring.

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