Tobacco leaf with stem harvesting machine

Abstract

This invention discloses a tobacco leaf harvester with stem, relating to the field of tobacco harvesting machinery technology. It includes a chassis assembly with a chain conveyor assembly mounted on it. The chain conveyor assembly comprises a front horizontal access section, a middle curved transition section, and a rear inclined lifting section. An extension / retraction guide device and an extension / retraction drive device are provided between the inclined lifting section and the chassis assembly. This invention, through its inclined extension / retraction mechanism, can adapt to different cut-off heights, has good site adaptability, and helps improve harvesting smoothness and reduce leaf damage during the harvesting process.

Description

Technical Field

[0001] This invention relates to the field of tobacco harvesting machinery technology, and in particular to a tobacco harvester with stems. Background Technology

[0002] Tobacco leaf harvesting with stems is a technique that harvests tobacco leaves along with part of the stem. This technique has advantages such as reduced harvesting workload and improved quality of tobacco leaf ripening, leading to its increasing use. Furthermore, due to the high repetitiveness of this harvesting operation, mechanized harvesting machinery has been developed. As these machines move along the plant's orientation, the stems passively enter parallel sections of a chain conveyor system. The lower part of the plant is then cut off, and the cut upper stem is conveyed backward by the chain conveyor system. Once at the collection box, the stems are manually stacked, leaving approximately 25-40 cm of stalks in the field for later removal by other machinery.

[0003] However, these harvesting machines with stems are mostly designed based on grain harvesting principles, and some problems still exist when applied to tobacco harvesting. These problems are primarily reflected in the incompatibility of equipment caused by the differences in harvesting characteristics between tobacco and other crops. Specifically, the leaves that grow on the tobacco stem are the final part needed (in Shandong, the top 6-8 leaves are usually harvested). When cutting, the height of the bottom leaf is taken as a reference, such as cutting 6-10cm below the bottom leaf. Therefore, the cutting position will be different for tobacco plants in different tobacco fields, and even different rows in the same tobacco field. The cutting height from the ground mostly fluctuates within the above-mentioned range of 25-40cm, but existing tobacco harvesting machines with stems do not have the function of adapting to different cutting heights.

[0004] To address this, some harvesters with stems have designed their chain conveyor assembly to be tiltable and swingable, allowing them to adjust the height of the front end to accommodate different cutting heights. However, this type of chain conveyor assembly is tilted forward and downward, with the tilt angle increasing as the front end decreases. Since the chain in the assembly has at least two layers, meaning it clamps the stem at at least at two points during transport, a significant tilt angle can create a time lag when the stem enters at least two layers of the chain during harvesting. Due to the mismatch between the chain conveyor speed and the equipment's travel speed, this time lag can cause the stem to enter the parallel section of the chain conveyor in an uncertain posture, leading to problems such as poor stem cutting, and the leaves on the stem scraping, breaking, or even tearing against the chain conveyor assembly during transport. The current main solution to this problem is to extend the length of the chain conveyor assembly to reduce the tilt angle. However, this is equivalent to increasing the forward extension length of the chain conveyor assembly, thus increasing the overall machine length. In the context of limited space in fields, turning the machine around or moving it to another location becomes extremely difficult, reducing its adaptability to different sites. Therefore, further improvements to the tobacco leaf harvester with stems are needed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a tobacco stem harvester that is adaptable to different cutting heights, has good site adaptability, and helps to improve harvesting success and reduce leaf damage during the harvesting process.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a tobacco leaf harvester with stems, including a chassis assembly, on which a chain conveyor assembly is installed, the chain conveyor assembly including a front horizontal access section, a middle curved transition section and a rear inclined lifting section, and an extension and retraction guide device and an extension and retraction drive device are provided between the inclined lifting section and the chassis assembly; The chain conveyor assembly includes a conveyor support, on which two circulating chain assemblies are installed, each of which includes a circulating conveyor chain. The parallel sections of the two conveyor chains are used to jointly convey the stalks backward, and the parallel sections pass through the horizontal access section, the curved transition section and the inclined lifting section in sequence. The conveyor chain is formed by connecting the links end to end; each link includes a panel, and a connecting socket and a connecting head are integrally fixed on the back of the panel. The connecting head is inserted into the connecting socket adjacent to the front of the conveyor. A coarse connecting pin is installed on the connecting head, and a fine connecting pin is installed between the coarse connecting pin and the corresponding connecting socket. The connecting head is provided with a fine pin clearance hole corresponding to the fine connecting pin, and the fine pin clearance hole is an elongated hole along the circumference of the coarse connecting pin.

[0007] As a preferred technical solution, the extension and retraction drive device includes an extension and retraction transmission rack fixedly mounted on the inclined lifting section. An extension and retraction driver is mounted on the chassis assembly. The extension and retraction driver includes an extension and retraction hydraulic motor and a worm gear reducer. An extension and retraction transmission gear that meshes with the extension and retraction transmission rack is mounted on the output shaft of the worm gear reducer. An extension and retraction control valve is mounted on the chassis assembly. The extension and retraction control valve is used to control the forward and reverse rotation drive of the extension and retraction hydraulic motor.

[0008] As a preferred technical solution, a position stabilizing gear that meshes with the extension / retraction transmission rack is rotatably mounted on the chassis assembly; a position stabilizing pressure plate is slidably mounted on the chassis assembly along the axle axis of the position stabilizing gear; a stabilizing elastic element for driving the position stabilizing pressure plate to press against the side of the position stabilizing gear is mounted on the chassis assembly; a single-acting cylinder for driving the position stabilizing pressure plate away from the position stabilizing gear is mounted on the chassis assembly; the extension / retraction control valve is a Y-type three-position four-way valve, and the two outlets of the extension / retraction control valve are respectively connected to the inlet and outlet of the extension / retraction hydraulic motor via pipelines; a shuttle valve is also mounted on the chassis assembly, and the two outlets of the extension / retraction control valve are respectively connected to the two inlets of the shuttle valve via pipelines; the outlet of the shuttle valve is connected to the inlet pipeline of the single-acting cylinder via pipeline.

[0009] As a preferred technical solution, the extension and retraction guide device includes extension and retraction guide rails fixedly installed on the left and right sides of the conveying bracket, and upper guide wheel sets, lower guide wheel sets and side guide wheel sets are respectively installed on the chassis assembly corresponding to each extension and retraction guide rail.

[0010] As a preferred technical solution, at least two vertically arranged feeding protrusions are integrally fixed on the front of the panel, and the feeding protrusions on the two parallel sections are staggered in the conveying direction; a plurality of extrusion plates are respectively provided on the back of each parallel section on the conveying bracket, and the plurality of extrusion plates are arranged along the conveying direction, and a pushing guide mechanism and an elastic force application mechanism are respectively provided between each extrusion plate and the conveying bracket; a chain support plate for supporting the parallel section is fixedly provided on the lower part of each extrusion plate.

[0011] As a preferred technical solution, a drive sprocket is rotatably mounted at the rear end of the conveying bracket, and a driven wheel seat is movably mounted at the front end of the conveying bracket in the front-rear direction. A driven sprocket is rotatably mounted on the driven wheel seat, and an elastic tensioning mechanism is provided between the driven wheel seat and the conveying bracket. The distance between the portions of the two conveying chains located between the corresponding driven sprockets and the parallel sections gradually decreases along the conveying direction, and the distance between the portions of the two conveying chains located between the corresponding parallel sections and the drive sprocket gradually increases along the conveying direction.

[0012] As a preferred technical solution, one of the driven sprockets is provided with a lever seat, and a plurality of evenly arranged levers are fixed on the circumferential surface of the lever seat.

[0013] As a preferred technical solution, a conveying drive shaft is rotatably mounted on the conveying bracket below the two drive sprockets. The axle of each drive sprocket is connected to the conveying drive shaft via bevel gears. The conveying drive shaft is connected to a conveying driver.

[0014] As a preferred technical solution, the conveying support is provided with a cutting-off device located below the entrance of the parallel section.

[0015] As a preferred technical solution, a collection box is installed on the chassis assembly at the output end of the chain conveyor assembly. The collection box includes a shallow box near the chain conveyor assembly and a deep box behind the shallow box. A detachable connection device is provided between the deep box and the chassis assembly.

[0016] Due to the adoption of the above technical solution, the chain conveyor assembly of the present invention is configured with a horizontal access section, a curved transition section in the middle, and an inclined lifting section at the rear. The chain conveyor assembly relies on the inclined lifting section for inclined telescopic installation. During harvesting, the leafy stems enter the chain conveyor assembly from the horizontal access section. By driving the inclined lifting section forward or backward, the ground clearance of the horizontal access section can be changed, thus adapting to different cut-off heights. The horizontal access section ensures that, regardless of the cut-off height, the conveyor chain passively receives the stems in a horizontal posture, which helps avoid the impact of the difference between conveying speed and traveling speed. This allows the stems to enter the horizontal access section essentially vertically and be conveyed backward essentially perpendicular to the conveying direction, improving harvesting smoothness and reducing leaf damage during harvesting. When not harvesting, the chain conveyor assembly can be inclined backward, reducing the overall length of the machine. This facilitates turning the machine around and relocating it in situations with limited space in the field, demonstrating good site adaptability. Attached Figure Description

[0017] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the invention. Wherein: Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 yes Figure 1 A top-down view and a cross-sectional view of the square beam; Figure 3 yes Figure 2 Enlarged schematic diagram of the structure at the parallel section with stems in the middle biting and feeding; Figure 4 yes Figure 3A magnified schematic diagram of the structure of three links in the chain; Figure 5 yes Figure 4 A schematic diagram of the AA structure in the diagram; Figure 6 This is a diagram showing the state of the chain segment when no stem passes through the curved transition section in an embodiment of the present invention; Figure 7 yes Figure 6 A diagram showing the state of the chain segment as a stalk passes by; Figure 8 yes Figure 1 A schematic diagram of the cross-sectional structure at the mid-bend transition section; Figure 9 yes Figure 1 A cross-sectional view of the transmission gear at the center extension point; Figure 10 yes Figure 1 A cross-sectional view of the gear in the centrally located stable position. Figure 11 This is a hydraulic schematic diagram of the single-handle control extension and retraction in an embodiment of the present invention; Figure 12 yes Figure 1 Enlarged schematic diagram of the K-axis structure in the diagram; Figure 13 yes Figure 1 A diagram showing the state of the chain conveyor after assembly and reception.

[0018] In the diagram: 1 - Chassis assembly; 2-Chain conveyor assembly; 21-Horizontal access section; 22-Bending transition section; 23-Inclined lifting section; 24-Stalk seat; 241-Stalk; 25-Introduction structure; 26-Cutting device; 27-Collection box; 271-Shallow box; 272-Deep box; 273-Easy-to-disassemble connection device; 3-Conveyor support; 31-Square beam; 32-Crossbeam; 33-Bottom longitudinal beam; 4-Conveyor chain; 41-Parallel section; 42-Drive sprocket; 43-Driven wheel seat; 44-Driven sprocket; 45-Elastic tensioning mechanism; 46-Chain bending guide structure; 47-Conveyor drive shaft; 48-Conveyor driver; 5-Chain link; 51-Panel; 52-Connecting recess; 53-Connecting head; 54-Connecting coarse pin; 55-Connecting fine pin; 56-Fine pin clearance hole; 57-Bending clearance clearance; 58-Sprocket mating part; 59-Feeding protrusion; 6-Extrusion force plate; 61-Pushing guide mechanism; 62-Pushing guide cylinder; 63-Pushing guide rod; 64-Rod side connecting ear plate; 65-Plate side connecting ear plate; 66-Elastic force application mechanism; 67-Chain support plate; 7-Extension and retraction guide device; 71-Extension and retraction guide rail; 72-Upper guide wheel assembly; 73-Lower guide wheel assembly; 74-Side guide wheel assembly; 8-Extension and retraction drive device; 81-Extension and retraction transmission rack; 82-Extension and retraction transmission gear; 83-Extension and retraction driver; 831-Extension and retraction hydraulic motor; 832-Worm gear reducer; 84-Extension and retraction control valve; 9-Position-stabilizing gear; 91-Position-stabilizing pressure plate; 92-Stabilizing elastic element; 93-Single-acting cylinder; 94-Shuttle valve; 95-Stabilizing mounting tube; 96-Stabilizing linkage pin; 97-Stabilizing transmission nut. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments. Firstly, it should be noted in the embodiments that the portion to be harvested is defined as "stem" or "stem with leaves" in this text, while the portion left in the field is defined as "straw." The definitions of "front," "rear," "left," and "right" are all based on the conventional understanding of front, rear, left, and right during normal operation. Similarly, "conveyor front" and "conveyor rear" are also based on conventional understanding, with the direction of forward conveying being the conveyor front and the direction of opposite conveying direction being the conveyor rear. The front and back of the panel 51 are also based on conventional understanding, with the side of the panel 51 that directly contacts the stem being the front and the opposite side being the back. These conventionally understood names and directional definitions are intended to clearly explain the structural principle and are not intended to limit the scope of protection.

[0020] like Figure 1 , Figure 2 and Figure 13 As shown, the tobacco leaf harvester with stem includes a chassis assembly 1, which is an integrated unit for locomotion, power source, etc., and serves as the carrier for harvesting and other functional components. Specifically, in this embodiment, the chassis assembly 1 uses a tracked chassis, on which components such as an oil tank, pump station, and control valves are installed. If necessary, it can be equipped with components such as an engine and gearbox, so that in addition to providing locomotion drive, it can also be equipped with a straw pulling mechanism to provide PTO (Power Towing) output. These settings can be derived using conventional technical means and will not be elaborated further here, nor are they shown in detail in the figure.

[0021] A chain conveyor assembly 2 is mounted on the chassis assembly 1. The chain conveyor assembly 2 is a functional component for harvesting tobacco leaves with stems and conveying the harvested leafy stems backward. In this embodiment, the chain conveyor assembly 2 includes a front horizontal access section 21, a middle curved transition section 22, and a rear inclined lifting section 23. An extension / retraction guide device 7 and an extension / retraction drive device 8 are provided between the inclined lifting section 23 and the chassis assembly 1. Through this arrangement, the chain conveyor assembly 2 is obliquely telescopically mounted on the chassis assembly 1. During harvesting, the leafy stems enter the chain conveyor assembly 2 from the horizontal access section 21. By driving the inclined lifting section 23 to extend forward or retract backward, the ground clearance of the horizontal access section 21 can be changed, thus adapting to different cutting heights. The horizontal access section 21 ensures that the conveyor chain 4 passively receives the stalks in a horizontal posture regardless of the cut-off height. This helps avoid the impact of the difference between the conveying speed and the traveling speed, allowing the stalks to enter the horizontal access section 21 in a basically vertical state and be conveyed backward in a posture basically perpendicular to the conveying direction. This improves harvesting smoothness and reduces leaf damage during the harvesting process. When not harvesting, the chain conveyor assembly 2 can be tilted backward to reduce the overall length of the machine. This facilitates turning the machine around and relocating it in situations with limited space in the field, demonstrating good site adaptability.

[0022] Among them, such as Figure 1 and Figure 2 As shown, the chain conveyor assembly 2 specifically includes a conveyor support 3. Two circulating chain assemblies arranged opposite each other are installed on the conveyor support 3. Each circulating chain assembly includes a circulating conveyor chain 4. The parallel segments 41 of the two conveyor chains 4 are used to jointly convey the stalks backward. The parallel segments 41 pass through the horizontal access segment 21, the curved transition segment 22 and the inclined lifting segment 23 in sequence. Correspondingly, the parallel segments 41 are adapted to the three segments to form horizontal, curved and inclined changes in sequence.

[0023] Specifically, such as Figures 2 to 5As shown, the conveyor chain 4 is formed by connecting the two ends of chain links 5. Each chain link 5 includes a panel 51, on the back of which a connecting socket 52 and a connecting head 53 are integrally fixed. The connecting head 53 is inserted into the connecting socket 52 adjacent to the front of the conveyor. A connecting coarse pin 54 is mounted on the connecting head 53, and a connecting fine pin 55 is mounted between the connecting coarse pin 54 and the corresponding connecting socket 52. The connecting head 53 is provided with a fine pin clearance hole 56 corresponding to the connecting fine pin 55, and the fine pin clearance hole 56 is an elongated hole along the circumference of the connecting coarse pin 54. The above arrangement forms the connection between the two ends of the chain links 5, and adjacent chain links 5 have both the degree of freedom to rotate relative to each other around the connecting fine pin 55 and the degree of freedom to rotate relative to each other around the connecting coarse pin 54. The former ensures that the conveyor chain 4 can rotate around the sprocket, and the latter ensures that a bending change can be formed in the bending transition section 22, or in other words, the bending can change the direction from horizontal to oblique. In the case where the conveyor chain 4 can be bent from horizontal to oblique, a bending clearance gap 57 is preferably provided between adjacent panels 51 to ensure that the bending can be achieved.

[0024] Furthermore, such as Figure 4 and Figure 5 As shown, in this embodiment, the upper and lower sides of the opening of the connecting socket 52 are integrally provided with sprocket mating parts 58. These sprocket mating parts 58 can engage with the teeth of the corresponding sprockets, enabling the conveyor chain 4 to be driven by the sprockets. The two sprocket mating parts 58 effectively form two layers of chain drive in the height direction of the conveyor chain 4, promoting the stability of the conveyor chain 4's cyclic operation. In this embodiment, the connecting pin 55 passes through the two sprocket mating parts 58 to form an installation.

[0025] Normally, such as Figure 1 , Figure 2 and Figure 13 As shown, a drive sprocket 42 is rotatably mounted at the rear end of the conveying bracket 3, and a driven wheel seat 43 is movably mounted at the front end of the conveying bracket 3 in the front-rear direction. A driven sprocket 44 is rotatably mounted on the driven wheel seat 43, and the conveying chain 4 is wound around the drive sprocket 42 and the driven sprocket 44 on the corresponding sides. An elastic tensioning mechanism 45 is provided between the driven wheel seat 43 and the conveying bracket 3 to keep the conveying chain 4 taut. At the same time, the elastic tensioning mechanism has a retractable nature, so that when the parallel section 41 receives the stalks, the conveying chain 4 will not be over-tensioned due to the expansion of the stalks, which is beneficial to promoting the stability of the stalk biting and conveying. According to the aforementioned structure of the conveying chain 4, both the drive sprocket 42 and the driven sprocket 44 are two-layer sprocket structures, which are respectively adapted to the two-layer sprocket mating parts 58 to realize the chain operation.

[0026] like Figure 8 , Figure 9 and Figure 10 As shown, in this embodiment, at least two vertically arranged feeding protrusions 59 are integrally fixed on the front surface of the panel 51, such as... Figure 2 and Figure 3 As shown, the biting protrusions 59 on the two parallel sections 41 are staggered in the conveying direction. Thus, the two side panels 51 of the parallel section 41 and the biting protrusions 59 adjacent in the conveying direction can jointly form a biting grip on the stem. This biting grip can stably form a four-sided restriction, which can make the leafy stem received by the parallel section 41 quickly enter a stable biting state, which is conducive to the smooth cutting of the lower part of the stem.

[0027] like Figure 2 , Figure 3 as well as Figures 8 to 10 As shown, the conveying support 3 is provided with a plurality of compression plates 6 on the back of each of the parallel sections 41. The plurality of compression plates 6 are arranged along the conveying direction. Each compression plate 6 is provided with a pushing guide mechanism 61 and an elastic force application mechanism 66 between it and the conveying support 3. The lower part of each compression plate 6 is fixedly provided with a chain support plate 67 for supporting the parallel section 41. Accordingly, the compression plate 6 becomes a structure that supports the parallel section 41 and can transmit the compression action of the parallel section 41. Relying on the retractability of the elastic force application mechanism 66, it is ensured that the compression plate 6 at the chain link 5 where the stem expands in the opposite direction can retract, ensuring the passage of the stem while maintaining the compression action. Preferably, each of the compression plates 6 corresponds to 3 to 5 chain links 5, so that the compression plates 6 only retract at the positions where the leafy stems pass through, while the compression plates 6 at other positions remain in the closed state of the corresponding parallel segments 41. This can ensure the four-sided gripping restriction of the aforementioned stems, promote the stable gripping state of the leafy stems throughout the backward conveying process, and further promote the backward conveying of the leafy stems in an attitude that is basically perpendicular to the conveying direction.

[0028] Among them, several of the extrusion plates 6 simultaneously form a guide structure for the parallel section 41. The structures on the back of the panel 51, such as the connecting recess 52, connecting head 53, and sprocket mating part 58, preferably have their top surfaces protruding from the back of the panel 51 coplanar, to adapt to the extrusion plates 6 and form a guiding motion. Furthermore, the extrusion plates 6 located in the curved transition section 22 and their chain support plates 67 are arranged corresponding to the curved shape of the conveyor chain 4, and such... Figure 6 , Figure 7 and Figure 8 As shown, a chain bending guide structure 46 is fixedly provided on the conveying bracket 3 at least above the conveying chain 4 of the bending transition section 22 to restrict the bending part from the top, so as to ensure the smooth transition of the parallel section 41 from horizontal to oblique and avoid stability problems caused by chain jumping.

[0029] The pushing guide mechanism 61 described in this embodiment includes a pushing guide cylinder 62 fixedly installed on the conveying bracket 3. A pushing guide rod 63 is installed on the pushing guide cylinder 62. Two rod-side connecting ear plates 64 arranged vertically are fixedly provided on the outer end of the pushing guide rod 63. A plate-side connecting ear plate 65 located between the two rod-side connecting ear plates 64 is fixedly provided on the extrusion force plate 6. A pushing connecting bolt passes through the plate-side connecting ear plate 65 and the rod-side connecting ear plate 64. Through the planar contact between the rod cylinder guide and the ear plate, the extrusion force plate 6 is installed without sagging. Accordingly, the chain support plate 67 can play its role in supporting the parallel section 41.

[0030] Preferably, two pushing guide mechanisms 61 are respectively provided between each of the extrusion force-applying plates 6 and the conveying bracket 3. The plate-side connecting ear plates 65 of the two pushing guide mechanisms 61 can jointly form a rotation restriction of the pushing guide rod 63, thereby ensuring the conveying and guiding function of the extrusion force-applying plate 6. An extrusion force-applying pad is fitted on the pushing guide rod 63 at the rod-side connecting ear plate 64. The elastic force-applying structure includes a compression spring fitted outside the pushing guide cylinder 62 and the pushing guide rod 63 and located between the extrusion force-applying pad and the conveying bracket 3. Of course, the inner end of the pushing guide rod 63 and the inner wall of the pushing guide cylinder 62 can be respectively provided with an outward limiting boss to limit the extreme position of the extrusion force-applying plate 6. This can be derived by combining conventional technical means, and will not be elaborated here.

[0031] In addition to the above description of the conveying process in parallel section 41, it should also be noted that in the parallel section 41 of the horizontal access section 21 and the inclined lifting section 23, because the conveying path is straight, the effect of the stem being held and conveyed remains unchanged. This effect only applies to the parallel section 41 of the curved transition section 22. Figure 6 As shown, due to the bending of the chain, the spacing of the biting protrusions 59 at different heights will vary slightly; that is, the spacing of the higher biting protrusions 59 in the conveying direction is slightly smaller, while the spacing of the lower biting protrusions 59 in the conveying direction is slightly larger. However, based on the rotatability of adjacent chain links 5 around the connecting pin 54, the two chain links 5 used to hold the stem can still maintain a basically perpendicular state relative to the stem when passing through the bending transition section 22. It is only these two chain links 5, and possibly the chain links 5 connected to them, that will undergo rotational deformation relative to adjacent chain links 5 on the same chain in the opposite direction to the bending change, such as... Figure 7 As shown, the stem maintains reliable gripping when passing through the bending transition section 22, based on the rotatability of the adjacent chain links 5 around the connecting pin 54. Here, it is only necessary for the chain support plate 67 on the pressure plate 6 at the bending transition section 22 to have sufficient gap to accommodate the above deformation.

[0032] like Figure 2 As shown, the distance between the portions of the two conveyor chains 4 located between the corresponding driven sprockets 44 and the parallel section 41 gradually decreases along the conveying direction. This causes the conveyor chains 4 before the parallel section 41 to guide the stems, facilitating their smooth entry into the parallel section 41. Preferably, one of the driven sprockets 44 is fixedly provided with a stem-pulling seat 24, and several evenly arranged levers 241 are fixedly provided on the circumference of the stem-pulling seat 24. The levers 241 further facilitate the smooth entry of the stems into the parallel section 41 through their actuation. Preferably, the conveyor support 3 is fixedly provided with an inlet structure 25 located before the two driven sprockets 44. The distance between the portions of the two conveyor chains 4 located between the corresponding parallel section 41 and the driving sprocket 42 gradually increases along the conveying direction. This causes the conveyor chains 4 after the parallel section 41 to open and release the leafy stems.

[0033] Based on the need to transport leafy stems, the cross-section of the main body of the transport support 3 is roughly U-shaped to provide transport space for the stems held by the parallel section 41. Specifically, as Figure 9 and Figure 10 As shown, the conveying support 3 includes two opposing square beams 31. The two square beams 31 are designed to match the shape of the horizontal access section 21, the curved transition section 22, and the inclined lifting section 23. In other words, the square beams 31 are curved so that the front section is horizontal and the rear section is inclined. Several crossbeams 32 are fixedly connected to the bottom of the two square beams 31 to form an integral frame. Further, a bottom longitudinal beam 33 can be fixedly connected to the middle of the crossbeams 32 at the inclined lifting section 23 to improve the overall rigidity of the conveying support 3. Based on the use of the square beams 31, the forward section of the conveying chain 4 passes through the inner cavity of the square beams 31. Thus, the square beams 31 act as a guide for the forward section of the conveying chain 4, promoting smooth operation of the conveying chain 4 while simplifying the structure.

[0034] Also based on avoiding the path of transporting stems, such as Figure 12 As shown, in this embodiment, a conveying drive shaft 47 is rotatably mounted on the conveying bracket 3 below the two drive sprockets 42. The axles of each drive sprocket 42 are connected to the conveying drive shaft 47 via bevel gears. The conveying drive shaft 47 is connected to a conveying driver 48. That is, the drive transmission part for the conveying chain 4 also forms a U-shape. Of course, after the two sets of bevel gears are driven, the rotation directions of the two drive sprockets 42 are opposite.

[0035] Normally, such as Figure 1 and Figure 13As shown, a cutting device 26 is provided on the conveying support 3 below the entrance of the parallel section 41. The cutting device 26 is used to cut off the lower part of the stem that has entered the parallel section 41 and been bitten. The cutting device 26 is implemented using a circular saw, which is easily derived from existing technology and will not be elaborated here. Based on the strong biting and conveying effect of the parallel section 41 and the basically vertical posture of the stem in this embodiment, the cutting device 26 can achieve effective cutting by using only a single-sided circular saw.

[0036] like Figure 2 , Figure 9 and Figure 10 As shown, the extension and retraction guide device 7 in this embodiment includes extension and retraction guide rails 71 fixedly installed on the left and right sides of the conveying bracket 3. Upper guide wheel sets 72, lower guide wheel sets 73, and side guide wheel sets 74 are respectively installed on the chassis assembly 1 corresponding to each extension and retraction guide rail 71. The upper guide wheel sets 72 and lower guide wheel sets 73 restrict the vertical movement of the conveying bracket 3, while the side guide wheel sets 74 restrict the horizontal movement of the conveying bracket 3. This ensures that the chain conveying assembly 2 remains stable regardless of its extension or retraction position. Furthermore, the wheel-rail guidance method has low resistance, avoiding the interference of the chain conveying assembly 2's own gravity bending moment on the extension and retraction process.

[0037] like Figure 1 and Figure 9 As shown, the extension / retraction drive device 8 includes an extension / retraction transmission rack 81 fixedly mounted on the inclined lifting section 23. An extension / retraction driver 83 is mounted on the chassis assembly 1. The extension / retraction driver 83 includes an extension / retraction hydraulic motor 831 and a worm gear reducer 832. An extension / retraction transmission gear 82 meshing with the extension / retraction transmission rack 81 is mounted on the output shaft of the worm gear reducer 832. An extension / retraction control valve 84 is mounted on the chassis assembly 1. The extension / retraction control valve 84 is used to control the forward and reverse rotation of the extension / retraction hydraulic motor 831. Conventionally, as... Figure 11As shown, the extension / retraction control valve 84 can be a three-position four-way valve, preferably controlled by a handle; the three positions are forward, neutral, and reverse, and the control effect of the extension / retraction hydraulic motor 831 is achieved by switching between different positions. Specifically, when the handle is operated to switch the extension / retraction control valve 84 to the forward position, the extension / retraction hydraulic motor 831 outputs forward rotation and drives the extension / retraction transmission gear 82 to rotate forward, and the chain conveyor assembly 2 extends forward under the gear and rack transmission; conversely, when the handle is operated to switch the extension / retraction control valve 84 to the reverse position, the extension / retraction hydraulic motor 831 outputs reverse rotation and drives the extension / retraction transmission gear 82 to rotate reverse, and the chain conveyor assembly 2 retracts; and when the handle is operated to switch the extension / retraction control valve 84 to the neutral position, the extension / retraction hydraulic motor 831 stops driving, and the chain conveyor assembly 2 stops. The control of the extension / retraction hydraulic motor 831 by this three-position four-way valve is easily understood using conventional technical means and will not be elaborated further here.

[0038] Preferably, such as Figure 1 and Figure 10 As shown, a position stabilizing gear 9 that meshes with the extension / retraction transmission rack 81 is rotatably mounted on the chassis assembly 1. A position stabilizing pressure plate 91 is slidably mounted on the chassis assembly 1 along the axle axis of the position stabilizing gear 9. A stabilizing elastic element 92 is mounted on the chassis assembly 1 to drive the position stabilizing pressure plate 91 to press against the side of the position stabilizing gear 9. A single-acting cylinder 93 is mounted on the chassis assembly 1 to drive the position stabilizing pressure plate 91 away from the position stabilizing gear 9. (Reference) Figure 11 The extension / retraction control valve 84 is a Y-type three-position four-way valve. The two outlets of the extension / retraction control valve 84 are respectively connected to the inlet and outlet of the extension / retraction hydraulic motor 831 by pipelines. A shuttle valve 94 is also installed on the chassis assembly 1. The two outlets of the extension / retraction control valve 84 are respectively connected to the two inlets of the shuttle valve 94 by pipelines. The outlet of the shuttle valve 94 is connected to the inlet of the single-acting cylinder 93 by pipeline.

[0039] Based on the above structure, this embodiment uses a handle for control, which achieves the effect of automatically locking the chain conveyor assembly 2 when extension / retraction stops and automatically unlocking it when extension / retraction starts. Specifically: Conventionally, a three-position four-way valve has a P port for connecting to the high-pressure oil supply line, a T port for connecting to the return oil line, and A and B ports for connecting hydraulic components. The extension and retraction hydraulic motor 831 has an inlet and an outlet. When the extension and retraction control valve 84 is in the neutral position, the single-acting cylinder 93 is kept retracted under the elastic force of the internal elastic element and the stabilizing elastic element 92. The position stabilizing pressure plate 91 presses against the position stabilizing gear 9, and the position stabilizing gear 9 is locked by the friction force generated by the pressing. The position stabilizing gear 9 locks the conveying bracket 3 based on the gear and rack meshing. In this way, the vibration caused by stem biting and cutting can be reduced during the harvesting process, and the operation can be stabilized. When the chain conveyor assembly 2 needs to be retracted, the handle of the retraction control valve 84 is directly operated to switch it to the reverse position. At this time, high-pressure oil is supplied from port B of the retraction control valve 84 to the outlet of the retraction hydraulic motor 831, while the retraction hydraulic motor 831 returns oil from port A of the retraction control valve 84, realizing reverse output, and the chain conveyor assembly 2 generates a retraction action. At the same time, the high-pressure oil from port B of the retraction control valve 84 enters the shuttle valve 94, causing its internal valve core to move to the position of blocking the other inlet. Port B of the retraction control valve 84 is connected to the outlet of the shuttle valve 94, and the high-pressure oil enters the single-acting cylinder 93. The single-acting cylinder 93 pushes the position stabilizing pressure plate 91 away from the position stabilizing gear 9, and its locking effect disappears. Thus, by operating the handle once, the locking effect is achieved simultaneously during reverse drive, and the chain conveyor assembly 2 can directly generate a retraction action. When the desired position is reached, the operating handle moves the extension control valve 84 to the neutral position. For the Y-type three-position four-way valve, at this time, its upper A port and B port are connected to the T port, that is, connected to the return oil pipeline. The inlet and outlet of the extension hydraulic motor 831 are at equal pressure, and the extension hydraulic motor 831 stops rotating. Since the A port and B port are connected to the T port, and the valve core in the shuttle valve 94 is kept on the original A port side, the hydraulic oil in the single-acting cylinder 93 can enter the T port through the B port to achieve the purpose of pressure relief. The single-acting cylinder 93 retracts under the elastic force of the internal elastic element and the stabilizing elastic element 92. The position stabilizing pressure plate 91 presses against the position stabilizing gear 9 again to lock again, achieving the effect of stopping and locking the chain conveyor assembly 2 with one operation of the handle. When the chain conveyor assembly 2 needs to be extended, operate the handle of the extension control valve 84 to switch it to the forward position. At this time, the A port of the extension control valve 84 supplies high-pressure oil to the inlet of the extension hydraulic motor 831, while the extension hydraulic motor 831 returns oil from the B port of the extension control valve 84, realizing forward output. The chain conveyor assembly 2 then extends forward. At the same time, the high-pressure oil from the A port of the extension control valve 84 enters the shuttle valve 94, causing its internal valve core to move to the position of blocking the other inlet. The A port of the extension control valve 84 is connected to the outlet of the shuttle valve 94, and the high-pressure oil enters the single-acting cylinder 93. The single-acting cylinder 93 pushes the position stabilizing pressure plate 91 away from the position stabilizing gear 9, and its locking effect disappears. That is, by operating the handle once, the locking effect is simultaneously released when driving forward, and the chain conveyor assembly 2 can smoothly extend forward. After extending to the designated position, the extension / retraction control valve 84 is moved to the neutral position via the operating handle for immediate stop and lock. Thus, in this embodiment, the lock is automatically released during both extension and retraction, ensuring that the corresponding action can be performed directly and smoothly. When stopping extension or retraction, the valve automatically locks, achieving stable and reliable operation with a simple single-handle operation.

[0040] The stabilizing elastic element 92 can be a combination of the elastic element within the single-acting cylinder 93, or it can be provided separately. This embodiment illustrates a separate configuration. Specifically, as shown... Figure 10As shown, in this embodiment, a stabilizing mounting tube 95 is fixedly provided on the chassis assembly 1. The inner hole of the stabilizing mounting tube 95 is polygonal, and a stabilizing linkage pin 96 adapted to its inner hole is inserted into the stabilizing mounting tube 95, thereby forming a sliding installation of the stabilizing linkage pin 96. The position stabilizing pressure plate 91 is fixedly provided on one end of the stabilizing linkage pin 96 extending out of the stabilizing mounting tube 95, and the other end of the stabilizing linkage pin 96 extending out of the stabilizing mounting tube 95 is connected to the piston rod of the single-acting cylinder 93. In this embodiment, the stabilizing elastic element 92 is set separately. A thread is machined at the end of the stabilizing linkage pin 96 connected to the piston rod of the single-acting cylinder 93, and a stabilizing transmission nut 97 is installed. A compression spring is fitted on the stabilizing linkage pin 96 between the stabilizing transmission nut 97 and the stabilizing mounting tube 95 to form the stabilizing elastic element 92. In this configuration, the stabilizing linkage pin 96 is not necessarily actually connected to the piston rod of the single-acting cylinder 93. It is sufficient that the piston rod of the single-acting cylinder 93 can abut against the stabilizing linkage pin 96 when extended. When the piston rod of the single-acting cylinder 93 retracts, the stabilizing linkage pin 96 can restore the pressing action of the position stabilizing pressure plate 91 under the elastic force of the stabilizing elastic element 92. After pressing, the polygonal structure of the stabilizing linkage pin 96 and the stabilizing mounting tube 95 can restrict the rotation of the stabilizing linkage pin 96, achieving the anti-rotation locking effect of the position stabilizing gear 9. Of course, friction plates can preferably be provided at the pressing surfaces of the position stabilizing pressure plate 91 and the position stabilizing gear 9 to enhance the locking effect. The extension stroke of the piston rod of the single-acting cylinder 93 only needs to be a few millimeters to allow the position stabilizing pressure plate 91 to disengage from the position stabilizing gear 9. Therefore, the single-acting cylinder 93 can be implemented using a commonly used single-acting thin hydraulic cylinder.

[0041] Normally, such as Figure 1 and Figure 13 As shown, a collection box 27 is installed on the chassis assembly 1 at the output end of the chain conveyor assembly 2 to temporarily store the leafy stems after the conveying process is complete. Conventionally, this storage involves manually picking up the leafy stems after the conveying process and placing them sequentially into the collection box 27. Preferably, the collection box 27 includes a shallow box 271 near the chain conveyor assembly 2 and a deep box 272 located behind the shallow box 271. A detachable connection device 273 is provided between the deep box 272 and the chassis assembly 1. The deep box 272 serves as the main storage container for the harvested leafy stems. It can be completely removed using the detachable connection device 273, facilitating direct replacement of the empty box and reducing damage caused by individually moving the harvested leafy stems. The shallow box 271 is designed to accommodate the extension and retraction range of the chain conveyor assembly 2 during operation, ensuring that the harvested leafy stems can smoothly reach the collection box 27.

[0042] The detachable connection device 273 can be implemented using a wheel-rail guiding structure combined with fixed-point locking. Specifically, a box guide rail is fixedly installed on the chassis assembly 1, and the box guide rail is arranged in the left-right direction. The bottom of the deep box 272 is equipped with a set of box wheels for traveling on the box guide rail. Fixed-point locking lugs are correspondingly provided on the chassis assembly 1 and the deep box 272, and fixed-point locking bolts are threaded through the fixed-point locking lugs. When the fixed-point locking bolts are removed, the deep box 272 can be removed from the side by relying on wheel-rail guidance. A new empty box can also be reinstalled on the chassis assembly 1 by means of wheel-rail guidance. The wheel-rail guiding method can reduce the resistance during unloading and reduce the intensity of unloading operations. After the empty box is reinstalled in the fixed position, the fixed-point locking bolts are reinstalled.

[0043] In this embodiment, the chain conveyor assembly 2 is designed as a horizontal receiving and then oblique conveying type. The harvesting height can be adjusted by oblique extension, broadening its applicability to different rows and tobacco fields. Even when different harvesting heights exist on the same row, height adjustment can be made in real time. Furthermore, the extension operation can be achieved with a single handle, allowing for immediate stop and lock, and immediate unlock and start, making operation simple and reliable. Regardless of the harvesting height, the leafy stems are held in a basically vertical position by the parallel section 41 and conveyed backward in a posture basically perpendicular to the conveying direction. Throughout the process, the problem of stem breakage due to excessive tilting is significantly reduced, improving harvesting smoothness. At the same time, the leaf friction, breakage, and tearing caused by large tilting during the conveying process are also significantly reduced, minimizing leaf damage during harvesting. When not harvesting, such as Figure 13 As shown, the chain conveyor assembly 2 can be tilted backward to reduce the overall length of the machine, which is beneficial for turning the machine around and relocating it in situations where space is limited in the field. It has good site adaptability.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A tobacco leaf harvester with stems, comprising a chassis assembly, wherein a chain conveyor assembly is mounted on the chassis assembly, characterized in that: The chain conveyor assembly includes a front horizontal access section, a middle curved transition section, and a rear inclined lifting section. An extension and retraction guide device and an extension and retraction drive device are provided between the inclined lifting section and the chassis assembly. The chain conveyor assembly includes a conveyor support, on which two circulating chain assemblies are installed, each of which includes a circulating conveyor chain. The parallel sections of the two conveyor chains are used to jointly convey the stalks backward, and the parallel sections pass through the horizontal access section, the curved transition section and the inclined lifting section in sequence. The conveyor chain is formed by connecting the links end to end; each link includes a panel, and a connecting socket and a connecting head are integrally fixed on the back of the panel. The connecting head is inserted into the connecting socket adjacent to the front of the conveyor. A coarse connecting pin is installed on the connecting head, and a fine connecting pin is installed between the coarse connecting pin and the corresponding connecting socket. The connecting head is provided with a fine pin clearance hole corresponding to the fine connecting pin, and the fine pin clearance hole is an elongated hole along the circumference of the coarse connecting pin.

2. The tobacco leaf harvester with stem as described in claim 1, characterized in that: The retraction drive device includes a retraction transmission rack fixedly mounted on the inclined lifting section. A retraction driver is mounted on the chassis assembly. The retraction driver includes a retraction hydraulic motor and a worm gear reducer. A retraction transmission gear that meshes with the retraction transmission rack is mounted on the output shaft of the worm gear reducer. A retraction control valve is mounted on the chassis assembly. The retraction control valve is used to control the forward and reverse rotation of the retraction hydraulic motor.

3. The tobacco leaf harvester with stem as described in claim 2, characterized in that: A position stabilizing gear that meshes with the retraction drive rack is rotatably mounted on the chassis assembly. A position stabilizing pressure plate is slidably mounted on the chassis assembly along the axle axis of the position stabilizing gear. A stabilizing elastic element for driving the position stabilizing pressure plate to press against the side of the position stabilizing gear is mounted on the chassis assembly. A single-acting cylinder for driving the position stabilizing pressure plate away from the position stabilizing gear is mounted on the chassis assembly. The retraction control valve is a Y-type three-position four-way valve. The two outlets of the retraction control valve are respectively connected to the inlet and outlet of the retraction hydraulic motor via pipelines. A shuttle valve is also mounted on the chassis assembly. The two outlets of the retraction control valve are respectively connected to the two inlets of the shuttle valve via pipelines. The outlet of the shuttle valve is connected to the inlet pipeline of the single-acting cylinder.

4. The tobacco leaf harvester with stem as described in claim 1, characterized in that: The extension and retraction guide device includes extension and retraction guide rails fixedly installed on the left and right sides of the conveying bracket, and upper guide wheel sets, lower guide wheel sets and side guide wheel sets are respectively installed on the chassis assembly corresponding to each extension and retraction guide rail.

5. The tobacco leaf harvester with stem as described in claim 1, characterized in that: At least two vertically arranged feeding protrusions are integrally fixed on the front of the panel, and the feeding protrusions on the two parallel sections are staggered in the conveying direction; a plurality of extrusion plates are respectively provided on the back of each parallel section on the conveying bracket, and the plurality of extrusion plates are arranged along the conveying direction. A pushing guide mechanism and an elastic force application mechanism are respectively provided between each extrusion plate and the conveying bracket; a chain support plate for supporting the parallel section is fixedly provided on the lower part of each extrusion plate.

6. The tobacco leaf harvester with stem as described in claim 1, characterized in that: A drive sprocket is rotatably mounted at the rear end of the conveying bracket, and a driven wheel seat is movably mounted at the front end of the conveying bracket in the front-rear direction. A driven sprocket is rotatably mounted on the driven wheel seat, and an elastic tensioning mechanism is provided between the driven wheel seat and the conveying bracket. The distance between the portions of the two conveying chains located between the corresponding driven sprockets and the parallel sections gradually decreases along the conveying direction, while the distance between the portions of the two conveying chains located between the corresponding parallel sections and the drive sprocket gradually increases along the conveying direction.

7. The tobacco leaf harvester with stem as described in claim 6, characterized in that: One of the driven sprockets is provided with a lever seat, and a plurality of levers are fixedly arranged evenly on the circumferential surface of the lever seat.

8. The tobacco leaf harvester with stem as described in claim 6, characterized in that: A conveying drive shaft is rotatably mounted on the conveying bracket below the two drive sprockets. The axle of each drive sprocket is connected to the conveying drive shaft via bevel gears. The conveying drive shaft is connected to a conveying driver.

9. The tobacco leaf harvester with stem as described in claim 1, characterized in that: The conveying support is equipped with a cutting device located below the entrance of the parallel section.

10. The tobacco leaf harvester with stem as described in claim 1, characterized in that: A collection box is installed on the chassis assembly at the output end of the chain conveyor assembly. The collection box includes a shallow box near the chain conveyor assembly and a deep box behind the shallow box. A detachable connection device is provided between the deep box and the chassis assembly.

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