Crop straw crushing and returning device and harvester applying same

Abstract

The utility model provides a kind of crop straw crushing and returning to field device and the harvester of applying the device, the returning to field device is installed in the rear tail of harvester, and straw processing mode can be switched quickly.The device includes shell assembly and crushing assembly, the movable flap lower end of shell assembly is hinged to the lower part of base shell front side by pin shaft, and the opening and closing of feed channel is adjusted and controlled by angular displacement.When straw needs to be processed away from field, movable flap rotates clockwise, and abuts against the rear side plate of base shell, feed channel is closed, and straw slides along the U-shaped groove to fall into field;When it needs to be returned to field, movable flap rotates counterclockwise to preset position, forming a gradually broadening feed section, and straw is thrown into field after being crushed by crushing assembly.Application of the device to the harvester enables farmers to make independent and flexible decisions on the destination of straw based on soil characteristics, policy guidance, cost and benefit, and planting system, thereby improving the utilization rate of straw resources and the flexibility of agricultural operations.

Description

Technical Field

[0001] This utility model relates to the field of agricultural machinery technology, and in particular to a crop straw crushing and returning device and a harvester using the device. Background Technology

[0002] Crop straw, as a byproduct of agricultural production, consists of the organic matter remaining after the harvest of mature crops, including stems, leaves, and rachis. It is rich in nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, and organic matter, and possesses significant biomass resource attributes. Currently, the main ways to utilize straw include direct crushing and returning it to the field to improve soil, as well as collecting and processing it into feed, fuel, and building materials.

[0003] In theory, agricultural producers should scientifically select straw disposal methods based on factors such as soil fertility conditions, agricultural policy guidance, economic cost-effectiveness, and planting system requirements.

[0004] However, in reality, because the straw returning device is an optional configuration module for harvesters, its loading state is irreversible; that is, dynamic switching between returning and removing the straw cannot be achieved within the same work cycle. Furthermore, harvesters operate on a standardized basis, with each plot as the smallest unit. When a harvester equipped with a straw returning device enters a target plot, the straw treatment method is forcibly locked to crushing and returning. If the harvester is not equipped with a straw returning device, the straw left in the field must be disposed of by the farmer separately. These characteristics of harvesters create a rigid constraint on straw disposal decisions, preventing farmers from flexibly deciding the straw's fate based on factors such as soil characteristics, policy guidance, cost-benefit analysis, and planting system requirements. In effect, this deprives them of their autonomy as operators.

[0005] In summary, those skilled in the art urgently need to develop a straw crushing and returning device that is flexible in operation and can quickly switch straw processing modes, as well as a harvester that should be used for the returning device. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model provides a crop straw crushing and returning device and a harvester using the device, in order to solve the problems in the background technology.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] This utility model provides a crop straw crushing and returning device and a harvester using the device. In a first aspect, the returning device includes:

[0009] The shell assembly is a split configuration, including a base shell and a movable flap. The lower end of the movable flap is hinged to the lower front part of the base shell by a pin. The angular displacement of the movable flap around the pin can be adjusted so that the feeding channel formed with the base shell can be opened / closed, thereby controlling the flow direction of straw.

[0010] The crushing component is installed in the inner cavity of the base shell to crush the straw that enters the inner cavity and evenly scatter it into the field from the discharge port at the lower rear of the base shell;

[0011] When the straw needs to be removed from the field, the movable flap rotates clockwise around the pin shaft, the upper edge of the movable flap abuts against the rear side plate of the base shell, the feeding channel closes, and the straw slides down into the field along the inclined U-shaped groove formed by the movable flap and the left and right side plates of the base shell.

[0012] When the straw needs to be returned to the field, the movable flap rotates counterclockwise to a preset position. The movable flap, the left side plate, the rear side plate, and the right side plate are connected end to end to form a gradually widening feeding section. The feeding channel is opened, and the straw enters the inner cavity from the feeding channel, is crushed by the crushing component, and is scattered into the field.

[0013] In one possible implementation, the base housing further includes an arc-shaped lower bottom plate, which is sealed to the bottom of the left side plate and the right side plate, so that the inner cavity has a parabolic structure.

[0014] In one possible implementation, the returning-to-field device further includes a flap drive assembly, which is specifically a flap handle or a flap motor;

[0015] When the flap handle is manual, the flap handle is located outside the left side plate or the right side plate. The lower end of the flap handle is fixedly connected to the lower end of the left or right side of the movable flap. When the flap handle is turned, the movable flap rotates around the pin as the axis of rotation.

[0016] When the flip-plate motor is electric, the flip-plate motor is located outside the left side plate or the right side plate. The lower end of the flip-plate motor is fixedly connected to the lower end of the left or right side of the movable flip-plate. When the flip-plate motor is started, the movable flip-plate rotates around the pin shaft as the rotation axis.

[0017] In one possible implementation, the crushing assembly includes a moving blade module and a fixed blade module that operates in coordination with the moving blade module, wherein;

[0018] The moving blade module includes a moving blade shaft and moving blades. The left and right ends of the moving blade shaft are mounted on the left side plate and the right side plate via bearing seats. There are several moving blades arranged in a spiral on the moving blade shaft. The moving blades rotate under the drive of the moving blade shaft.

[0019] The fixed blade module includes a fixed blade holder that can rotate and swing up and down. The left and right ends of the fixed blade holder are hinged to the left side plate and the right side plate via a fixed blade shaft. The fixed blade has several blade holes, and the fixed blade is inserted into the blade holes. The exposed blade at the front end of the fixed blade is arranged alternately with the moving blade. The exposed blade at the front end of the fixed blade and the rotation trajectory of the moving blade form a shearing segment.

[0020] In one possible implementation, when the fixed blade holder is rotated counterclockwise upwards, the fixed blade rises accordingly, the shearing section that intersects with the moving blade becomes longer, and the particle size of the crushed straw becomes finer;

[0021] When the fixed blade holder is rotated clockwise downwards, the fixed blade is lowered accordingly, the shearing section that intersects with the moving blade becomes shorter, and the particle size of the crushed straw becomes coarser.

[0022] In one possible implementation, the fixed tool module further includes a fixed shaft, and a fixed tool hole is provided at the rear end of the fixed tool. The fixed shaft passes through the fixed tool hole from left to right, so that the fixed tool can be quickly disassembled and replaced.

[0023] In one possible implementation, the fixed-blade module further includes a protective strip made of rubber, which is located above the fixed-blade holder and covers the fixed-blade module.

[0024] In one possible implementation, both the moving blade and the fixed blade have serrated edges and are coated with an alloy coating.

[0025] In one possible implementation, the returning-to-field device further includes a rear tail fin mounted on the rear side of the housing assembly and located above the discharge port. The rear tail fin includes a wing plate hinged to the base housing, allowing the wing plate to rotate about the hinge point, either tilting upwards or downwards.

[0026] Several guide vanes are arranged at intervals from left to right below the wingplate, and the blade angle of the guide vanes is adjustable.

[0027] Secondly, a harvester is provided that incorporates the aforementioned field-returning device, which is located at the rear of the harvester. Beneficial effects

[0028] This utility model provides a crop straw crushing and returning device and a harvester using the device. The returning device is installed at the rear of the harvester and can quickly switch straw processing modes. The device includes a shell assembly and a crushing assembly. The lower end of the movable flap of the shell assembly is hinged to the lower front side of the base shell by a pin, and the opening and closing of the feeding channel is controlled by angular displacement adjustment. When the straw needs to be removed from the field, the movable flap rotates clockwise and abuts against the rear side plate of the base shell, closing the feeding channel, and the straw slides down the U-shaped groove into the field. When it needs to be returned to the field, the movable flap rotates counterclockwise to a preset position, forming a gradually widening feeding section. The straw enters the inner cavity, is crushed by the crushing assembly, and then scattered into the field. Harvesters using this device enable farmers to make autonomous and flexible decisions about the straw disposal based on soil characteristics, policy guidance, cost-benefit, and planting systems, thereby improving the resource utilization rate of straw and the flexibility of agricultural operations. Attached Figure Description

[0029] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of the returning-to-field device in a specific implementation. Figure 1 ;

[0031] Figure 2 This is a top view of the structure of the returning-to-field device in a specific implementation embodiment;

[0032] Figure 3 This is a schematic diagram of the returning-to-field device in a specific implementation. Figure 2 ;

[0033] 1-Shell assembly; 11-Base shell; 111-Left side plate, 112-Right side plate; 113-Rear side plate; 114-Lower bottom plate; 12-Movable flap; 2-Crushing assembly; 21-Moving blade module; 211-Moving blade shaft; 212-Moving blade; 22-Fixed blade module; 221-Fixed blade holder; 222-Fixed blade; 223-Protective strip; 3-Flap handle; 4-Rear tail fin; 41-Flange; 42-Guide plate. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. In addition, for the sake of convenience, the terms "upper," "lower," "left," and "right" are equivalent to the upper, lower, left, and right directions of the accompanying drawings themselves, and the terms "first," "second," etc., are used for descriptive purposes and have no other special meaning.

[0035] To address the shortcomings of existing technologies, this utility model provides a crop straw crushing and returning device and a harvester using the device. The returning device is installed at the rear of the harvester and can quickly switch straw processing modes. The returning device includes a housing assembly, a crushing assembly, and a rear tail fin, as detailed below:

[0036] 1-Housing assembly

[0037] The shell assembly is a split configuration, including a base shell and a movable flap. The lower end of the movable flap is hinged to the lower front part of the base shell by a pin. The angular displacement of the movable flap around the pin can be adjusted so that the feeding channel formed by it and the base shell can be opened / closed, thereby controlling the flow direction of straw.

[0038] In specific application scenarios, the split-type shell assembly uses the relative movement of the movable flap and the base shell, with the movable flap rotating around the pin shaft, to allow the feeding channel to be opened or closed as needed, thereby flexibly controlling the flow direction of straw and thus determining whether the straw is to be removed from the field or returned to the field.

[0039] Furthermore, the movable flap controls the opening and closing of the feeding channel through angular displacement adjustment, thereby realizing the dynamic switching of straw processing modes, which greatly improves the flexibility and efficiency of agricultural operations and meets the needs of different operating scenarios.

[0040] The principle of switching straw processing modes of this straw returning device is as follows: When the straw needs to be removed from the field, the movable flap rotates clockwise around the pin shaft, and the upper edge of the movable flap abuts against the rear side plate of the base shell, closing the feeding channel. The straw slides down into the field along the inclined U-shaped groove formed by the movable flap and the left and right side plates of the base shell. When the straw needs to be returned to the field, the movable flap rotates counterclockwise to the preset position, and the movable flap, left side plate, rear side plate and right side plate connect end to end to form a gradually widening feeding section. The feeding channel opens, and the straw enters the inner cavity from the feeding channel, is crushed by the crushing component and scattered into the field.

[0041] In specific application scenarios, the straw return device offers simple and flexible switching between straw treatment modes, enabling farmers to choose between straw removal from the field or return to the field based on their actual needs. This improves the utilization rate of straw resources, enhances the flexibility of agricultural operations, increases farmers' autonomy in making choices, and promotes sustainable development.

[0042] In one possible implementation, the base shell also includes an arc-shaped lower bottom plate, which is sealed to the bottom of the left and right side plates, making the inner cavity a parabolic structure.

[0043] In specific application scenarios, the bottom plate of the base shell is designed with an arc shape, making the entire inner cavity form a parabolic structure. This structure guides the crushed straw to flow out more smoothly, reducing accumulation and blockage in the inner cavity. At the same time, it allows the crushed straw to be more evenly scattered from the discharge port to the field, expanding the scattering range and improving the return-to-field effect.

[0044] In addition, the arc-shaped bottom plate works in conjunction with the moving blade module and the fixed blade module in the crushing assembly to guide the straw to the shearing area, increasing the contact opportunities between the straw and the moving and fixed blades, so that the straw can be crushed more thoroughly, thereby improving the crushing efficiency.

[0045] In some examples, the returning device also includes a flap drive assembly, which is specifically a flap handle or a flap motor;

[0046] When it is a manual flap handle, the flap handle is located on the outside of the left or right side panel. The lower end of the flap handle is fixedly connected to the lower end of the left or right side of the movable flap. When the flap handle is turned, the movable flap rotates around the pivot pin.

[0047] When the flip-board motor is electric, the flip-board motor is located on the outside of the left or right side of the flip-board. The lower end of the flip-board motor is fixedly connected to the lower end of the left or right side of the movable flip-board. When the flip-board motor is started, the movable flip-board rotates around the pivot pin.

[0048] In specific application scenarios, the flip-board drive assembly offers both manual and electric drive options, allowing this land-returning device to adapt widely to different working environments and conditions. The manual flip-board handle is simple in structure and easy to operate; simply turning the handle rotates the movable flip-board without relying on an additional power source, making it both economical and practical. The electric flip-board motor features a high degree of automation, significantly reducing labor intensity and greatly improving work efficiency.

[0049] 2-Crushing Components

[0050] The crushing component is installed inside the base shell to crush the straw that enters the inner cavity and then evenly spread it into the field from the discharge port at the bottom rear of the base shell.

[0051] In some examples, the crushing assembly includes a moving blade module and a fixed blade module that works in coordination with the moving blade module, so that the straw can be efficiently cut and crushed after entering the crushing assembly, ensuring that the straw is effectively processed.

[0052] The moving blade module includes a moving blade shaft and moving blades. The left and right ends of the moving blade shaft are mounted on the left and right side plates via bearing seats. There are several moving blades arranged in a spiral on the moving blade shaft. The moving blades rotate under the drive of the moving blade shaft, so that the moving blades can rotate at high speed to form a continuous cutting surface, which can efficiently and quickly cut and crush the straw entering the inner cavity.

[0053] In specific application scenarios, a driven wheel is provided at the left or right end of the moving blade shaft. The driven wheel is connected to the output end of the harvester to ensure the smooth transmission of torque.

[0054] The fixed blade module includes a fixed blade holder that can rotate and swing up and down. The left and right ends of the fixed blade holder are hinged to the left and right side plates via a fixed blade shaft. The fixed blade has several blade holes, and the fixed blade is inserted into the blade holes. The blade exposed at the front end of the fixed blade is arranged alternately with the moving blade. The blade exposed at the front end of the fixed blade and the rotation trajectory of the moving blade form a shearing segment.

[0055] In specific applications, the exposed blades of the fixed blade are arranged alternately with the moving blades, forming multiple shearing points or shearing segments. When the moving blades rotate at high speed, they generate a strong shearing force with the blades of the fixed blades, enhancing the shearing ability and thus effectively cutting and crushing the straw, thereby improving the crushing efficiency.

[0056] In some examples, when the fixed blade holder is rotated counterclockwise upwards, the fixed blade rises accordingly, the shearing section that intersects with the moving blade becomes longer, and the particle size of the crushed straw becomes finer;

[0057] When the fixed blade holder is rotated clockwise downwards, the fixed blades decrease in height, the shearing section that intersects with the moving blades becomes shorter, and the particle size of the crushed straw becomes coarser.

[0058] In specific applications, the fixed blade module utilizes a rotating and swinging fixed blade holder, allowing for adjustable shearing length between the fixed and moving blades. When the fixed blade holder is rotated counter-clockwise, the fixed blade rises, lengthening the shearing section that intersects with the moving blade, thus pulverizing the straw finer. Conversely, when the fixed blade holder is rotated clockwise, the fixed blade lowers, shortening the shearing section and coarsening the straw. This allows the pulverizing assembly to adapt to the different crop and soil conditions requiring varying straw particle sizes.

[0059] Furthermore, by adjusting the height of the fixed blade holder, this device can adapt to the processing needs of different types and moisture levels of straw. Whether processing dry or wet straw, it can achieve ideal crushing results, improving the adaptability and versatility of the equipment.

[0060] In some examples, the fixed tool module also includes a fixed shaft with a fixed tool hole at the rear end of the fixed tool. The fixed shaft passes through the fixed tool hole from left to right, allowing the fixed tool to be quickly disassembled and replaced.

[0061] In specific applications, the fixed blade is securely fixed to the fixed blade holder by passing the fixed shaft through the fixed blade hole. This reduces the risk of the fixed blade shifting or falling off due to vibration or impact during operation, thereby significantly improving the structural stability of the entire crushing assembly and ensuring the continuity and reliability of the crushing operation.

[0062] When the fixed tool wears out due to prolonged use or is damaged due to an accident and needs to be replaced, simply pull the fixed shaft out of the fixed tool hole to easily remove the fixed tool and replace it, making the disassembly and replacement process of the fixed tool simple and quick.

[0063] In some examples, the fixed-blade module also includes a protective strip made of rubber, located above the fixed-blade holder and covering the fixed-blade module. In the straw removal processing mode, the protective strip effectively prevents straw from accumulating at the fixed-blade module, making the straw cutting smoother. It also reduces external impacts and wear on the fixed-blade module, extending its service life.

[0064] In some examples, both the moving and stationary cutting edges are serrated and coated with an alloy coating.

[0065] In specific applications, the serrated blade design increases cutting efficiency, making straw easier to crush. The alloy coating improves the blade's hardness and wear resistance, reducing wear and damage during operation, thus extending the lifespan of both the stationary and moving blades and lowering replacement costs.

[0066] 3- Rear tail wing

[0067] In some examples, the straw return device also includes a rear tail fin, which is mounted on the rear side of the housing assembly and located above the discharge port. The rear tail fin optimizes the spreading effect of the crushed straw, so that the crushed straw can be spread evenly and accurately in the field, thereby improving the quality and efficiency of straw return.

[0068] The rear wing includes a wing plate hinged to the base shell, allowing the wing plate to rotate and tilt upwards or downwards around the hinge point. This allows the angle of the wing plate to be adjusted according to actual operational needs, thereby controlling the scattering range and direction of straw fragments. Furthermore, the rear wing can be tilted up, reducing the vehicle's turning radius and facilitating cross-regional relocation.

[0069] Several guide vanes are spaced apart from left to right below the wing plate, and the blade angle of the guide vanes is adjustable. By adjusting the angle of the guide vanes, the trajectory and distribution density of the straw fragments can be further controlled, achieving more precise straw return to the field and meeting the straw mulching needs of different plots and crops.

[0070] Example 1

[0071] Based on the above concept, such as Figure 1-3 As shown in the figure, this embodiment provides a specific application of the field-returning device, such as... Figure 1 As shown, the straw returning device is installed at the rear of the harvester, and can quickly switch between straw processing modes. It includes:

[0072] like Figure 1 As shown, the shell assembly 1 is a split configuration, including a base shell 11 and a movable flap 12. The lower end of the movable flap 12 is hinged to the lower front part of the base shell 11 by a pin. By adjusting the angular displacement of the movable flap 12 around the pin, the feeding channel formed by it and the base shell 11 can be opened / closed, thereby realizing the control of the straw flow direction.

[0073] like Figure 2 As shown, the crushing component 2 is installed in the inner cavity of the base housing 11 to crush the straw entering the inner cavity and evenly spread it to the field from the discharge port at the rear of the base housing 11.

[0074] When the straw needs to be removed from the field, the movable flap 12 rotates clockwise around the pin shaft, and the upper edge of the movable flap 12 abuts against the rear side plate 113 of the base shell 11, closing the feeding channel. The straw slides down into the field along the inclined U-shaped groove formed by the movable flap 12 and the left side plate 111 and right side plate 112 of the base shell 11.

[0075] When straw needs to be returned to the field, the movable flap 12 rotates counterclockwise to the preset position. The movable flap 12, the left side plate 111, the rear side plate 113 and the right side plate 112 are connected end to end to form a gradually widening feeding section. The feeding channel is opened, and the straw enters the inner cavity from the feeding channel. It is crushed by the crushing component 2 and scattered into the field.

[0076] In the example, such as Figure 3 As shown, the base housing 11 also includes an arc-shaped lower bottom plate 114, which is sealed to the bottom of the left side plate 111 and the right side plate 112, making the inner cavity a parabolic structure.

[0077] In the example, such as Figure 1 As shown, the returning-to-field device also includes a tilting plate drive assembly, which is specifically a tilting plate handle 3 or a tilting plate motor, wherein;

[0078] When the flap handle 3 is a manual type, the flap handle 3 is located outside the left side plate 111 or the right side plate 112. The lower end of the flap handle 3 is fixedly connected to the lower end of the left or right side of the movable flap 12. When the flap handle 3 is turned, the movable flap 12 rotates around the pivot pin.

[0079] In the example, such as Figure 2 As shown, the crushing assembly 2 includes a moving blade module 21 and a fixed blade module 22 that works in coordination with the moving blade module 21, wherein;

[0080] The moving blade module 21 includes a moving blade shaft 211 and moving blades 212. The left and right ends of the moving blade shaft 211 are mounted on the left side plate 111 and the right side plate 112 via bearing seats. There are several moving blades 212 arranged in a spiral on the moving blade shaft 211. The moving blades 212 rotate under the drive of the moving blade shaft 211.

[0081] The fixed blade module 22 includes a fixed blade holder 221 that can rotate and swing up and down. The left and right ends of the fixed blade holder 221 are hinged to the left side plate 111 and the right side plate 112 via the fixed blade 222 shaft. The fixed blade 222 has several blade holes, and the fixed blade 222 is inserted into the blade holes. The blade exposed at the front end of the fixed blade 222 is arranged alternately with the moving blade 212. The blade exposed at the front end of the fixed blade 222 and the rotation trajectory of the moving blade 212 form a shearing segment.

[0082] In the example, when the fixed blade holder 221 is rotated counterclockwise upwards, the fixed blade 222 rises accordingly, and the shearing section that intersects with the moving blade 212 becomes longer, resulting in finer particle size of the crushed straw.

[0083] When the fixed blade holder 221 is rotated clockwise downwards, the fixed blade 222 is lowered accordingly, the shearing section that intersects with the moving blade 212 becomes shorter, and the particle size of the crushed straw becomes coarser.

[0084] In the example, such as Figure 1 As shown, the fixed-blade module 22 also includes a protective strip 223. The protective strip 223 is made of rubber and is located above the fixed-blade holder 221, covering the fixed-blade module 22.

[0085] In the example, both the moving blade 212 and the fixed blade 222 have serrated edges and are coated with an alloy coating.

[0086] Example 2

[0087] Based on Example 1, such as Figure 1 As shown, the returning-to-field device also includes a rear tail wing 4, which is mounted on the rear side of the housing assembly 1 and located above the discharge port, as shown. Figure 2 As shown, the rear tail fin 4 includes a wing plate 41, which is hinged to the base housing 11, allowing the wing plate 41 to rotate about the hinge point, either tilting up or down. Figure 3As shown, several guide vanes 42 are arranged at intervals from left to right below the wing plate 41, and the blade angle of the guide vane 42 is adjustable.

Claims

1. A device for crushing and returning crop straw to the field, characterized in that, The field return device includes: The shell assembly (1) is a split configuration, including a base shell (11) and a movable flap (12). The lower end of the movable flap (12) is hinged to the lower front side of the base shell (11) by a pin. The angular displacement of the movable flap (12) around the pin is adjusted so that the feeding channel formed by it and the base shell (11) can be opened / closed, thereby realizing the control of the straw flow direction. The crushing component (2) is installed in the inner cavity of the base shell (11) to crush the straw that enters the inner cavity and to evenly scatter it into the field from the discharge port at the rear of the base shell (11). When the straw needs to be removed from the field, the movable flap (12) rotates clockwise around the pin shaft, the upper edge of the movable flap (12) abuts against the rear side plate (113) of the base shell (11), the feeding channel is closed, and the straw slides down into the field along the inclined U-shaped groove formed by the movable flap (12) and the left side plate (111) and right side plate (112) of the base shell (11); When the straw needs to be returned to the field, the movable flap (12) rotates counterclockwise to the preset position. The movable flap (12), the left side plate (111), the rear side plate (113) and the right side plate (112) are connected end to end to form a gradually widening feeding section. The feeding channel is opened, and the straw enters the inner cavity from the feeding channel. It is crushed by the crushing component (2) and scattered in the field.

2. The returning-to-field device according to claim 1, characterized in that, The base housing (11) also includes an arc-shaped lower bottom plate (114), which is sealed to the bottom of the left side plate (111) and the right side plate (112), making the inner cavity a parabolic structure.

3. The returning-to-field device according to claim 1, characterized in that, The field-returning device also includes a flip-board drive assembly, which is specifically a flip-board handle (3) or a flip-board motor, wherein; When the flap handle (3) is manual, the flap handle (3) is located outside the left side plate (111) or the right side plate (112). The lower end of the flap handle (3) is fixedly connected to the lower end of the left or right side of the movable flap (12). When the flap handle (3) is turned, the movable flap (12) rotates around the pin as the axis of rotation. When the flip-plate motor is electric, the flip-plate motor is located outside the left side plate (111) or the right side plate (112). The lower end of the flip-plate motor is fixedly connected to the lower end of the left or right side of the movable flip-plate (12). When the flip-plate motor is started, the movable flip-plate (12) rotates around the pin shaft as the rotation axis.

4. The returning-to-field device according to claim 1, characterized in that, The crushing assembly (2) includes a moving blade module (21) and a fixed blade module (22) that works in coordination with the moving blade module (21), wherein; The moving blade module (21) includes a moving blade shaft (211) and moving blades (212). The left and right ends of the moving blade shaft (211) are mounted on the left side plate (111) and the right side plate (112) via bearing seats. There are several moving blades (212) arranged in a spiral on the moving blade shaft (211). The moving blades (212) rotate under the drive of the moving blade shaft (211). The fixed blade module (22) includes a fixed blade holder (221) that can rotate and swing up and down. The left and right ends of the fixed blade holder (221) are hinged to the left side plate (111) and the right side plate (112) via the fixed blade (222) shaft. The fixed blade (222) has several blade holes. The fixed blade (222) is inserted into the blade holes. The blade exposed at the front end of the fixed blade (222) is arranged alternately with the moving blade (212). The blade exposed at the front end of the fixed blade (222) and the rotation trajectory of the moving blade (212) form a shearing segment.

5. The returning-to-field device according to claim 4, characterized in that, When the fixed blade holder (221) is rotated counterclockwise upwards, the fixed blade (222) rises accordingly, and the shearing section that intersects with the moving blade (212) becomes longer, resulting in finer particle size of the crushed straw. When the fixed blade holder (221) is rotated clockwise downwards, the fixed blade (222) is lowered accordingly, the shearing section that intersects with the moving blade (212) becomes shorter, and the particle size of the crushed straw becomes coarser.

6. The returning-to-field device according to claim 5, characterized in that, The fixed blade module (22) also includes a fixed shaft. The fixed blade (222) has a fixed blade (222) hole at its rear end. The fixed shaft passes through the fixed blade (222) hole from left to right, so that the fixed blade (222) can be quickly disassembled and replaced.

7. The field-returning device according to claim 5, characterized in that, The fixed blade module (22) also includes a protective strip (223), which is made of rubber and is located above the fixed blade holder (221), covering the fixed blade module (22).

8. The field-returning device according to claim 4, characterized in that, Both the moving blade (212) and the fixed blade (222) have serrated edges and are coated with an alloy coating.

9. The field-returning device according to claim 1, characterized in that, The returning-to-field device also includes a rear tail wing (4), which is mounted on the rear side of the housing assembly (1) and located above the discharge port. The rear tail wing (4) includes a wing plate (41), which is hinged to the base housing (11), allowing the wing plate (41) to rotate about the hinge point, either lifting or lowering. Several guide vanes (42) are arranged at intervals from left to right below the wing plate (41), and the blade angle of the guide vane (42) is adjustable.

10. A harvester, characterized in that, The harvester is equipped with a field-returning device as described in any one of claims 1-9, the field-returning device being located at the rear end of the harvester.

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