WO2022141985A1

WO2022141985A1 - Concave grate structure and combine harvester

Info

Publication number: WO2022141985A1
Application number: PCT/CN2021/089958
Authority: WO
Inventors: 王军; 邢立成; 邹杨昊
Original assignee: 江苏沃得农业机械股份有限公司
Priority date: 2020-12-30
Filing date: 2021-04-26
Publication date: 2022-07-07
Also published as: CN112690109A

Abstract

A concave grate structure and a combine harvester. The radian of the cross section of concave grates (2b, 3b) is 180 degrees. Connecting beams (5b) at two ends of each concave grate are horizontally arranged, and are in lap joint with the horizontal mounting surfaces of assembling beams (11b) in an attached manner. During mounting, the connecting beams (5b) are directly fixed to the assembling beams (11b) by means of locking assemblies. Palm holding, welding and fixing are not needed, the structure is simple, the mounting operation is easy and feasible, and manpower and material resources are saved. Limiting adjusting structures are arranged at notches (10b) formed between outer screen surfaces of the two concave grates (2b, 3b) and a transition grate (7b), and the limiting adjusting structures are detachably fixed to the concave grates (2b, 3b) at the two sides. When the limiting adjusting structures are not arranged, parts of crops only pass through the first concave grate (2b) and then fall into a lower vibrating screen from the notches (10b) to directly enter the subsequent process, and when the limiting adjusting structures are arranged, the crops enter the second concave grate (3b) from the first concave grate (2b) by means of the transition grate (7b) and is in a complete n-shaped trend, the conveying path is longer, and the threshing and screening effect is better.

Description

A concave plate screen structure and combine harvester

technical field

The application relates to the technical field of agricultural machinery, in particular to an adjustable concave screen structure and a combine harvester.

Background technique

The threshing system of the crawler combine harvester can be divided into a longitudinal axial flow threshing and cleaning system and a horizontal axial flow threshing and cleaning system. These two forms of threshing and cleaning systems are the main structural forms currently used in the market.

The existing transverse axial flow threshing and cleaning system is divided into a single drum transverse axial flow threshing and cleaning system and a 1.5 drum transverse axial flow threshing and cleaning system. Single-drum threshing is carried out by one drum, and the stroke of the crop is only the length of one drum. In the 1.5 drum system, a feeding drum with half the length is added in front of the single drum, that is, the additional half drum only plays the role of continuously feeding the crops, but hardly plays the role of threshing. , the threshing stroke of the existing transverse axial flow threshing and cleaning system is short. The corresponding concave screen, which is arranged under the front drum, has almost no screening effect.

When encountering varieties that are difficult to remove, the threshing and screening path is too short, and it is easy to cause some of the fed crop grains to be discharged from the body before they are screened out, resulting in losses.

SUMMARY OF THE INVENTION

Therefore, the technical problem to be solved by the present application is to overcome the short screening path of the concave screen corresponding to the drum in the prior art, which is easy to cause crop loss.

According to one aspect of the present application, a concave screen structure is proposed, comprising:

Two concave plate sieves are arranged in parallel and at intervals in the horizontal direction, the inner screen surface of any concave plate sieve is circular arc, and the radian of the cross section of the concave plate sieve is 180 degrees;

Any of the concave plate screens includes connecting beams horizontally arranged at both ends of the screen surface; the connecting beams are suitable for horizontally overlapping on the assembling beams of the frame;

Multiple sets of locking assemblies, any locking assembly is suitable for passing through the connecting beam and being locked and fixed on the assembling beam.

One end of the two concave plate screens located on the same side of the frame is provided with a transition port along the radial direction; the two transition ports are facing each other and communicate with each other;

a transition plate screen, laid between the two concave plate screens and connecting the two transition ports;

One of the concave plate screen is located at the opposite end of the transition port and away from the other end of the transition port to open a feeding port for crops;

The limit adjustment structure is detachably arranged at the gap formed between the outer screen surfaces of the two concave plate screens and the transition plate screen.

Preferably, the limit adjustment structure includes:

The sealing plate matches the shape of the gap, and the two sides are respectively fixed on the two concave plate screens.

Preferably, the limit adjustment structure further includes:

The two adjusting pieces are in the shape of a circular arc as a whole, and are respectively fixed on the two concave plate screens on both sides of the gap; the two sides of the sealing plate are respectively fixed on the two adjusting pieces.

Preferably, any one of the adjusting members includes:

an adjustment plate, the surface of which is in an arc shape matching the concave screen to which it is fixed; the surface of the adjustment plate is suitable for partially blocking the transition port;

Two mounting plates are bent along the adjusting plate and are respectively fixed on opposite sides of the adjusting plate; one of the mounting plates is suitable for being fixed on the concave screen, and the other is suitable for The sealing plate is fixedly connected.

Preferably, the cross-section of the adjusting member is in the shape of a trough.

Preferably, the locking assembly includes:

a fastener adapted to pass through the second mounting hole on the connecting beam and be fixed in the mounting hole on the mounting beam;

Washers are arranged between the connecting beam and the fastener and between the connecting beam and the assembling beam; the washer is coaxially sleeved on the fastener.

Preferably, the fastener is made of hexagonal steel.

Preferably, the fastener includes a hexagonal handle portion and a threaded portion formed under the handle portion; an internal thread matched with the threaded portion is provided in the assembly hole.

Preferably, the above-mentioned concave plate screen structure further includes a positioning assembly; the positioning assembly includes:

at least one positioning pin, arranged on the assembly beam;

The connecting beam is provided with a positioning hole, which is suitable for being sleeved on the positioning pin.

According to another aspect of the present application, a combine harvester is provided, comprising the above-mentioned concave plate screen structure.

The technical solution of the present application has the following advantages:

1. The concave plate screen structure provided by this application, a limit adjustment structure is provided at the gap formed between the outer screen surfaces of the two concave plate screens and the transition sieve plate, and the limit adjustment structure is detachably fixed on the concave holes on both sides. on a plate sieve. When the limit adjustment structure is not set, some crops only pass through the first concave plate screen and then fall into the lower vibrating screen from the gap, and directly enter the subsequent process. When the limit adjustment structure is set, the crops pass through the transition from the first concave plate screen The plate sieve enters the second concave plate sieve and passes through a complete "ji"-shaped trend, the transmission path is longer, and the threshing and screening effect is better.

2. In the concave plate screen structure provided by the present application, the limit adjustment structure includes an adjustment plate and mounting plates arranged on both sides of the adjustment plate. The plate surface of the adjustment plate is in the shape of an arc matching the concave plate screen. The plate surface of the adjustment plate is suitable for partially blocking the transition port. The adjustment plate can choose the size of the plate surface with different widths according to the needs, so as to realize the transition port through the crops. The size of the crop is adjusted, thereby partially prolonging the transmission path of the crop and prolonging the threshing, separation and screening time of the crop.

3. The concave plate screen structure provided by the application, the radian of the cross section of the concave plate screen is 180 degrees; the concave plate screen includes an arc-shaped screen surface and a connecting beam horizontally arranged at both ends of the screen surface, and the connecting beam is suitable for lap joints on the mounting beam of the rack. The connecting beam is set horizontally and can be lapped together with the horizontal mounting surface of the assembly beam on the frame. When installing, only need to put the concave plate screen between the two assembly beams, so that the connecting beam is placed on the assembly beam. , and then the connecting beam is fixed on the assembly beam through the locking component, without the need for palm support welding and fixing, the structure is simple, the installation operation is simple and easy, and the manpower and material resources are saved.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the accompanying drawings required in the description of the specific embodiments or the prior art will be briefly introduced below. The drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the structural representation one of the concave plate screen structure in the embodiment of the application;

2 is a schematic diagram 1 of the assembly structure of the concave plate screen structure in the embodiment of the application;

Fig. 3 is the assembly structure schematic diagram II of the concave plate screen structure in the embodiment of the application;

Fig. 4 is the second structural schematic diagram of the concave plate screen structure in the embodiment of the application;

5 is a schematic structural diagram three of the concave plate screen structure in the embodiment of the application;

FIG. 6 is a schematic diagram of the exploded structure of the assembly of the concave plate screen and the cylinder cover in the embodiment of the application.

Description of reference numbers:

1. Frame; 11b, assembling beam; 110b, assembling hole; 111b, locating pin; 2b, first concave plate screen; 21b, feeding port; 3b, second concave plate screen; 4b, side guard plate; 41b, steel wire 5b, connecting beam; 50b, second installation hole; 501b, positioning hole; 51b, grid bar; 6b, transition port; 7b, transition plate screen; 8b, reinforcing rib; 9b, sealing plate; 91b, adjusting plate ; 92b, mounting plate; 10b, notch;

2a, the first drum; 3a, the second drum; 2c, the first cylinder cover; 21c, the cover body; 22c, the mounting frame; 3c, the second cylinder cover; 9c, the fastener; 91c, the handle part; 92c, the thread part; 93c, gasket.

Detailed ways

The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood in specific situations.

In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict with each other.

Example 1

This embodiment provides a concave plate screen structure, as shown in FIG. 2 , including two concave plate screens, which are the first concave plate screen 2b with the feeding port 21b and the first concave plate screen 2b in the direction of crop transmission. The adjacently arranged second concave plate screens 3b, the first concave plate screens 2b and the second concave plate screens 3b have the same length, that is, the lengths of the screening areas are the same. The inner screen surface of each concave plate screen is in the shape of a circular arc, and the axes of the two concave plate screens are parallel to each other, and are fixed on the frame 1 at intervals along the horizontal direction.

As shown in FIG. 1 , each concave screen includes two side shields 4b, two connecting beams 5b, a plurality of grid bars 51b, a plurality of steel wires 41b and a plurality of reinforcing bars 8b. The two side shields 4b are arc-shaped respectively, the side shields 4b are coaxial and oppositely arranged, the two ends of the two side shields 4b are welded and fixed together by the connecting beam 5b, and the two side shields 4b are An installation space is enclosed between the two connecting beams 5b. In this embodiment, the grid bars 51b are arranged in parallel with the connecting beams 5b and fixed across the two side shields 4b. Radial distribution, that is, the plane where each grid bar 51b is located intersects on the axis of the concave screen, and the center of the arc where the side shield 4b is located is located on the axis. Each grid bar 51b is provided with a plurality of through holes evenly spaced. The steel wire 41b is arranged in parallel with the side shield 4b and passes through the through holes of each grid bar 51b in sequence. Both ends of the steel wire 41b are respectively fixed on the connecting beam 5b or grid bar 51b. All the grid bars 51b and the steel wires 41b intersect each other to form a plurality of grid units, and all the grid units together form a grid-like screen surface. In this embodiment, the reinforcing ribs 8b are arranged parallel to the side shields 4b, and are fixed at intervals on the outer screen surface. The grid bars 51b are welded and fixed to the side shields 4b on both sides, and the reinforcing rib 8b and all the grid bars 51b are also fixed by welding.

In this embodiment, the separation wrapping angles of the first concave plate screen 2b and the second concave plate screen 3b are both 180 degrees, that is, the side guard plate 4b is in a semicircular arc shape as a whole. When the separation angle is greater than 180 degrees, the upper space of the concave plate screen is wasted, and the upper part is curved, and the grains are thrown out of the concave plate screen from the upper part, and may fall back into the concave plate screen when falling, which affects the cleaning effect. When it is less than 180 degrees, the area of the screen surface is reduced, which also affects the cleaning effect.

In this embodiment, the area of the grid cells in the first concave plate screen 2b is smaller than the area of the grid cells in the second concave plate screen 3b, so that only crop grains pass through the first concave plate screen 2b, and the second concave plate screen The sieve is suitable for passing grains and other small impurities, so as to avoid the grains being entrained by the impurities and discharged from the grass discharge port, causing losses. Specifically, when the distance between two adjacent grid bars 51b in the two concave plate screens is the same, the distance between two adjacent steel wires 41b in the second concave plate screen 3b is greater than that in the first concave plate screen 2b The distance between two adjacent steel wires 41b; or, when the distance between two adjacent steel wires 41b in the two concave plate screens is the same, then the two adjacent grid bars 51b in the second concave plate screen 3b The distance between them is greater than the distance between two adjacent grid bars 51b in the first concave plate screen 2b; or the distance between the adjacent grid bars 51b and the adjacent steel wires 41b in the second concave plate screen 3b Both are larger than the spacing between adjacent grid bars 51b and adjacent steel wires 41b in the first concave plate screen 2b. Of course, the steel wires 41b in each concave plate screen can be drawn out at intervals as required, so as to increase the area of the grid unit.

As shown in Figure 1, the two concave plate screens are respectively provided with transition ports 6b and communicated with each other through the transition ports 6b. The transition plate screen 7b is laid between the two transition ports 6b. The transition plate screen 7b includes a screen frame and a screen. The frame has a square structure, and the grid bars 51b are arranged in the screen frame at uniform intervals in the transverse direction. Similarly, any grid bar 51b is provided with a plurality of through holes at uniform intervals, and the steel wires 41b pass through the through holes on the grid bars 51b in turn in the longitudinal direction. hole. Wherein, the width direction of the square screen frame is horizontal, and the length direction is vertical. The feeding port 21b is arranged on the side of the first concave screen 2b opposite to the transition port 6b and away from the transition port 6b.

As shown in FIG. 2, three assembling beams 11b are arranged on the frame 1 at intervals, and the connecting beams 5b on both sides of the first concave screen 2b are overlapped and fixed between the first and second two assembling beams 11b. Similarly, The connecting beams 5b on both sides of the second concave plate screen are overlapped and fixed between the second and third assembly beams 11b. The transition port 6b is opened close to one side of the frame 1 . The structural design makes the layout of the two concave plate screens on the harvester frame 1 compact, and at the same time, it can improve the path of crops passing through the concave plate screen threshing and screening, and greatly improve the overall mobility and threshing effect of the harvester.

As shown in Figure 3, a first threshing space is formed between the first cylinder cover 2c and the first concave plate screen 2b, the first drum 2a is installed in the first threshing space, and the first concave plate screen 2b and the first drum The end faces of the toggle teeth of 2a are arranged in a gap. A second threshing space is formed between the second cylinder cover 3c and the second concave plate screen 3b, and the second drum 3a is installed in the second threshing space. At the same time, the toggle teeth of the second concave plate screen 3b and the second drum 3a There is a gap between the end faces. The transition port 6b communicates with the first threshing space and the second threshing space, and the crops enter the second threshing space from the first threshing space through the transition plate screen 7b.

As shown in Figure 4, a limit adjustment structure is provided at the gap 10b formed between the outer screen surfaces of the two concave plate screens and the transition screen plate, and the limit adjustment structure is detachably fixed to the first concave plate screen on both sides. 2b and the second concave plate screen 3b. When the limit adjustment structure is not provided, part of the crops only pass through the first concave plate screen 2b and then fall into the lower vibrating screen from the gap 10b, and directly enter the subsequent process. 2b enters the second concave plate sieve 3b through the transition plate screen 7b and passes through the complete "ji"-shaped trend, the transmission path is longer, and the threshing and screening effect is better.

In this embodiment, the limit adjustment structure includes a sealing plate 9b, and the shape of the sealing plate 9b matches the shape of the notch 10b. Further, it also includes an adjustment member connecting the sealing plate 9b and the two concave screen screens. As shown in Figures 4 and 5, the adjustment member includes an adjustment plate 91b and two mounting plates 92b fixed on both sides of the adjustment plate 91b. The plate surface of the plate 91b is in the shape of an arc that matches the concave plate screen to which it is fixed. The two mounting plates 92b are bent along the adjusting plate 91b and are respectively fixed on the opposite sides of the adjusting plate 91b. One mounting plate 92b is used for fixing the connecting recess. The plate screen, another mounting plate 92b is used to fix and connect the sealing plate 9b. In this embodiment, the cross-section of the adjusting member is indented, and the adjusting plate 91b and the mounting plates 92b on both sides are integrally formed. The plate surface of the adjustment plate 91b is suitable for partially blocking the transition port 6b, and the adjustment plate 91b can choose the size of the plate surface with different widths according to the needs, so as to realize the adjustment of the size of the transition port 6b passing through the crops, thereby partially extending the transmission path of the crops, Extend the threshing separation screening time of crops.

As shown in Figure 6, the cylinder cover and the concave plate screen are fastened together up and down to form a hollow cylinder structure, and the enclosed cavity is suitable for installing a drum. The arc of the cross section of the concave plate screen and the cylinder cover is 180 degrees; the concave plate screen includes an arc-shaped screen surface and a connecting beam 5b horizontally arranged at both ends of the screen surface. on beam 11b. The cylinder cover includes a square mounting frame 22c and an arc-shaped cover 21c hinged to one side of the mounting frame 22c. The mounting frame 22c is suitable for surface-to-surface contact with the connecting beam 5b and overlapped on the mounting beam 11b. There are multiple sets of locking assemblies, and any locking assembly is adapted to pass through the mounting frame 22c and the connecting beam 5b in sequence and be locked and fixed on the mounting beam 11b. In this embodiment, the radian of the cross section of the concave plate screen is set at 180 degrees, which provides the best screening and separation angle. When the setting is greater than 180 degrees, the upper space of the concave plate screen is wasted. Secondly, the upper part is curved, and the seeds are thrown from above. When it falls out of the concave plate screen, it may fall into the concave plate screen again, which affects the cleaning effect.

The connecting beam 5b is arranged horizontally and can be overlapped with the horizontal installation surface of the assembly beam 11b on the frame 1. During installation, only the concave screen is placed between the two assembly beams 11b, so that the connecting beam 5b It only needs to be mounted on the assembly beam 11b, and there is no need to carry out palm welding and fixation, which reduces a lot of manpower and material resources.

In this embodiment, the overall structure of the first cylinder cover 2c and the second cylinder cover 3c is the same, and the dimensions are different according to requirements, such as different diameters. As shown in FIG. 6 , the mounting frame 22c has a square shape, and the cover 21c is hinged on one side of the mounting frame 22c. The frame surface of the mounting frame 22c is suitable for overlapping with the surface of the connecting beam 5b, which is convenient for assembly.

As shown in FIG. 6, the locking assembly includes a fastener 9c and a washer 93c. In this embodiment, the fastener 9c is made of hexagonal steel, and the fastener 9c includes a hexagonal handle The screw portion 92c below the portion 91c. Correspondingly, the assembling beam 11b is provided with assembling holes 110b which are threadedly matched with the threaded portion 92c, the installation frame 22c is provided with a plurality of first installation holes (not shown in the figure) at intervals along the frame, and a plurality of second installations are started at intervals on the connecting beam 5b. The hole 50b, the first mounting hole, the second mounting hole 50b and the mounting hole 110b are correspondingly arranged, and the fastener 9c passes through the first mounting hole and the second mounting hole 50b in sequence and is fixed in the mounting hole 110b, and the mounting frame 22c A washer 93c is provided between the fastener 9c and between the connecting beam 5b and the assembling beam 11b, and the washer 93c is coaxially sleeved on the threaded portion 92c of the fastener 9c. In this embodiment, the diameter of the corresponding first installation hole is smaller than the diameter of the second installation hole 50b, so as to correct the slight misalignment between the concave plate screen and the cylinder cover. Further, an inner thread may be set in the first mounting hole to cooperate with the outer thread of the fastener 9c to increase the locking strength.

In order to improve the accuracy of installation, a positioning assembly is also provided. As shown in FIG. 6 , the positioning assembly includes at least one positioning pin 111b, which is disposed on the assembling beam 11b. In this embodiment, two ends of each assembly beam 11b are respectively provided with a positioning pin 111b, and the positioning pin 111b is cylindrical. The connecting beam 5b and the mounting frame 22c are respectively provided with positioning holes 501b, and the positioning holes 501b are suitable for being sleeved on the corresponding positioning pins 111b. The positioning holes 501b on the connecting beam 5b and the mounting frame 22c have the same diameter and are slightly larger than the diameters of the positioning pins 111b, so as to correct the slight misalignment of the first and second mounting holes 50b relative to the mounting holes 110b.

The concave plate screen and the cylinder cover are integrally assembled to the assembly beam 11b of the harvester frame 1 through the fastener 9c, the structure is simple, the installation operation is simple and easy, and manpower and material resources are saved.

Example 2

This embodiment provides a combine harvester, including the concave plate screen structure described in Embodiment 1.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. However, the obvious changes or changes derived from this are still within the protection scope of the present application.

Claims

A concave plate screen structure is characterized in that, comprising:

Two concave plate sieves are arranged in parallel and at intervals in the horizontal direction, the inner screen surface of any concave plate sieve is in the shape of a circular arc, and the arc of the cross section of the concave plate sieve is 180 degrees;

Any one of the concave plate screens includes connecting beams (5b) horizontally arranged at both ends of the screen surface; the connecting beams (5b) are suitable for horizontally overlapping on the assembling beams (11b) of the frame (1);

Multiple sets of locking assemblies, any locking assembly is adapted to pass through the connecting beam (5b) and be locked and fixed on the assembling beam (11b);

A transition port (6b) is radially provided at one end of the two concave plate screens on the same side of the frame; the two transition ports (6b) are facing each other and communicate with each other;

a transition plate screen (7b), which is laid between the two concave plate screens and connects the two transition ports (6b);

A feeding port (21b) for crops is provided on the other end of the concave screen which is located opposite to the transition port (6b) and away from the transition port (6b);

The limit adjustment structure is detachably arranged at the gap (10b) formed between the outer screen surfaces of the two concave plate screens and the transition plate screen (7b).
The concave plate screen structure according to claim 1, wherein the limit adjustment structure comprises:

The sealing plate (9b) matches the shape of the notch (10b), and the two sides are respectively fixed on the two concave plate screens.
The concave plate screen structure according to claim 2, wherein the limit adjustment structure further comprises:

Two adjusting pieces, which are in the shape of an arc as a whole, are respectively fixed on the two concave screen screens on both sides of the gap (10b); the two sides of the sealing plate (9b) are respectively fixed on the two adjusting pieces on the piece.
The concave plate screen structure according to claim 3, wherein any one of the adjusting members comprises:

an adjusting plate (91b), the surface of which is in a circular arc shape matching the concave screen to which it is fixed; the surface of the adjusting plate (91b) is adapted to partially block the transition port (6b);

Two mounting plates (92b) are bent along the adjusting plate (91b) and are respectively fixed on opposite sides of the adjusting plate (91b); one of the mounting plates (92b) is suitable for being fixed on the concave plate On the screen, the other mounting plate (92b) is adapted to be fixedly connected to the sealing plate (9b).
The concave plate screen structure according to claim 4, wherein the cross-section of the adjusting member is in the shape of a groove.
The concave screen structure according to any one of claims 1-5, wherein,

The locking assembly includes:

a fastener (9c), adapted to pass through the second mounting hole (50b) on the connecting beam (5b), and be fixed in the mounting hole (110b) on the mounting beam (11b);

Washers (93c) are provided between the connecting beam (5b) and the fastener (9c) and between the connecting beam (5b) and the assembling beam (11b); the washers (93c) are the same as The shaft sleeve is arranged on the fastener (9c).
The concave screen structure according to claim 6, characterized in that, the fasteners (9c) are made of hexagonal steel.
The concave screen structure according to claim 7, wherein the fastener (9c) comprises a hexagonal handle portion (91c) and a threaded portion (92c) formed under the handle portion (91c); An internal thread matched with the threaded portion (92c) is provided in the mounting hole (110b).
The concave plate screen structure according to claim 6, further comprising a positioning assembly; the positioning assembly comprises:

at least one positioning pin (111b) arranged on the assembling beam (11b);

The connecting beam (5b) is provided with a positioning hole (501b), which is suitable for being sleeved on the positioning pin (111b).
A combine harvester is characterized in that it comprises the concave plate screen structure described in any one of claims 1-9.