Harvesting machine, threshing device and concave grid of threshing device

Abstract

The utility model relates to the field of harvesting machinery, and discloses a harvesting machinery, a threshing device and a concave grid thereof, the concave grid comprises a supporting frame, a plurality of longitudinal partition plates (3) and a plurality of grid strips (4), the longitudinal partition plates (3) and the grid strips (4) are connected to the supporting frame and mutually staggered and extend to form a grid, and a plurality of slots (31) which are distributed at intervals are respectively formed in each longitudinal partition plate (3). The grate bars (4) penetrate through the slots (31) to extend, and the portion, between every two adjacent slots (31), of each grate bar (4) protrudes towards the radial inner side. In the process that crop straw rotates along with the threshing cylinder, the concave grid is beneficial to separation of grains from the straw, the grain separation rate is increased, meanwhile, the amount of crushed straw and weeds carried in the separated grains is reduced, the risk that the grains are crushed or the surfaces of the grains are damaged is reduced, and the crushing rate and the loss rate of the grains are remarkably reduced.

Description

Technical Field

[0001] The utility model relates to the field of harvesting machinery, in particular to a concave plate screen for a threshing device. On this basis, the utility model also relates to a threshing device comprising the concave plate screen and a harvesting machinery comprising the threshing device. Background Art

[0002] For example, a fully-fed grain harvesting machine such as a combine harvester usually includes functional modules such as a cutting table, a crop conveying device, a threshing device, and a cleaning system. After the crop straw is cut off by the cutting table, it is transported to the threshing device by the crop conveying device; as the threshing drum rotates, the threshing device applies mechanical force to the crop to separate the grain from the straw; the fallen grains fall into the cleaning system, and the grains are separated from the impurities such as the crushed straw by a vibrating screen and a blower. Among them, as the core component of the harvesting machinery, the threshing device has a decisive influence on the separation rate and crushing rate of the grains. It usually includes a plurality of axially connected concave plate screens and a threshing drum rotatably mounted on the inner side of the concave plate screen. As the threshing drum rotates, the crop straw passes through the gap between it and the concave plate screen, so that the grains and the straw are separated by impact, shearing, combing, etc.

[0003] In a conventional threshing device, a concave plate screen generally includes a longitudinal partition and a plurality of screen bars passing through the longitudinal partition and extending along an arc line, wherein the screen bars are formed into an arc-shaped structure by a circular cross-section steel bar and are interlaced with the longitudinal partition to form a rectangular grid. The threshing drum drives the straw with grains to rotate at a high speed, so that the straw forms a mixture of impurities such as grains, broken straws and weeds under the action of the threshing drum and the concave plate screen. Under the action of centrifugal force, the grains and small-sized impurities enter the cleaning system through the rectangular grid of the concave plate screen, and then the grains are separated; the larger-sized straw segments and weeds continue to move axially and eventually leave the threshing device. In the concave plate screen, the purpose of positioning and improving the overall strength is achieved by extending the screen bars through the longitudinal partition, but this forms corners and steps on the inner edge of the longitudinal partition and between the longitudinal partition and the screen bars. Although this can produce a greater impact force and resistance on the straw and improve the separation rate of the grains, it also increases the amount of small-sized impurities and causes the grains to be easily broken and surface damaged.

[0004] In this regard, the prior art also provides a solution to reduce the grain breakage rate, wherein the concave screen used includes longitudinal bars and arc bars supported on the inner side of the longitudinal bars and extending along the arc line. The concave screen uses longitudinal bars to replace the longitudinal partitions, thereby reducing the number of edges and corners on the inner side, which can greatly reduce the collision between the grains and the edges and corners, thereby reducing the grain breakage rate. However, since the longitudinal bars are located radially outside the arc bars, their effect on the straw is significantly weakened, and the grain separation is mainly achieved by throwing the straw onto the concave screen and breaking the grain shell of, for example, a bean pod through collision, which will result in a loss of grain separation rate, and is particularly unsuitable for relatively difficult-to-separate crop types such as wheat, rice, and corn. Utility Model Content

[0005] The utility model aims to overcome the problem that the threshing device in the prior art is difficult to balance improving the grain separation rate and reducing the grain breakage rate, and provides a concave plate screen. When the crop straw rotates with the threshing drum, the concave plate screen helps to separate the grains from the straw, thereby improving the grain separation rate, while reducing the amount of broken straw and weeds carried in the separated grains, and reducing the risk of the grains being broken or having surface damage.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a concave plate screen on the one hand, including a supporting frame and a plurality of longitudinal partitions and a plurality of screen bars connected to the supporting frame and extending alternately to form a grid, each of the longitudinal partitions is respectively formed with a plurality of narrow grooves spaced apart from each other, the screen bars extend through the narrow grooves and the portion between two adjacent narrow grooves protrudes toward the radial inside.

[0007] Preferably, the support frame includes a pair of connecting plates arranged parallel to each other and a pair of arc-shaped side plates respectively connected to the two ends of the connecting plates, the two ends of the longitudinal partition are respectively connected to the arc-shaped side plates, the two ends of the arc-shaped side plates are respectively connected to the connecting plates, the screen bar is formed by bending circular cross-section steel and includes a plurality of straight line segments embedded in the narrow grooves, and the portion of the screen bar between two adjacent narrow grooves protrudes radially inward to form a smoothly extended curved section.

[0008] Preferably, along the rotation direction of the threshing drum in the concave screen, the curved section includes an ascending section extending from the straight section toward the radial inside and a descending section extending from the ascending section toward another adjacent straight section, and the length of the descending section is smaller than the length of the ascending section, so that the raised vertex of the curved section is closer to the other straight section located downstream.

[0009] Preferably, the connecting plate has a U-shaped cross section, and a plurality of connecting grooves are formed on the inner bending edge of the connecting plate, and the two ends of the screen bar are respectively embedded in the connecting grooves.

[0010] Preferably, the portions of the screen bars embedded in the connecting grooves and the narrow slots are flush with the surfaces of the connecting plates and the longitudinal partitions facing the threshing drum.

[0011] Preferably, a plurality of positioning grooves spaced apart from each other in the circumferential direction are formed on the radial inner side of the arc-shaped side plate, and both ends of the longitudinal partition plate are respectively embedded in the positioning grooves and are flush with the radial inner side of the arc-shaped side plate.

[0012] Preferably, the longitudinal partitions extend in directions parallel to the connecting plates and are perpendicular to the sections of the screen bars.

[0013] Preferably, the longitudinal partition includes a supporting portion and a guiding portion which have an angle with each other, the narrow groove is provided in the supporting portion, and the supporting portion is bent relative to the guiding portion along the rotation direction of the threshing drum in the concave screen.

[0014] Preferably, it also includes an intermediate support plate whose two ends are respectively connected to the middle part of the length direction of the connecting plate, the intermediate support plate extends in parallel with the arc-shaped side plate and has a plurality of support grooves spaced apart from each other formed on the radial inner side, the guide portion is embedded in the support groove and enables the support portion to be supported on the radial inner side of the intermediate support plate.

[0015] A second aspect of the present invention provides a threshing device, comprising the above-mentioned concave screen and a threshing drum rotatably arranged inside the concave screen.

[0016] A third aspect of the present invention provides a harvesting machine including the above-mentioned threshing device.

[0017] Through the above technical solution, the screen bar used in the concave plate screen of the utility model has a non-circular arc shape with concave-convex changes. During the rotation of the threshing drum, the crop straw can be repeatedly rubbed, squeezed and combed, so as to become soft and loose, which is not only conducive to maintaining the integrity of the straw, but also can promote secondary threshing, thereby improving the grain separation rate, while reducing the amount of broken straw and weeds carried in the separated grains. In addition, by extending the screen bar through the narrow slot of the longitudinal partition, the step between the screen bar and the longitudinal partition can be reduced or eliminated, thereby reducing the shear force and impact force on the straw and the grain, avoiding the straw from being torn and broken, and reducing the risk of the grain being broken or surface damage, so as to maintain a low grain breakage rate and loss rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a stereoscopic diagram of a concave plate screen according to a preferred embodiment of the utility model;

[0019] Figure 2 Observed from another perspective Figure 1 A stereoscopic view of a concave plate screen in FIG.

[0020] Figure 3 yes Figure 1 Axial projection view of the concave plate screen in FIG.

[0021] Figure 4 yes Figure 1 A perspective view of the concave screen with the longitudinal partitions and screen bars removed;

[0022] Figure 5 yes Figure 1 A three-dimensional view of the longitudinal partition of the concave plate screen;

[0023] Figure 6 yes Figure 1 The screen bars of the concave screen.

[0024] Description of Reference Numerals

[0025] 1-connecting plate; 11-connecting groove; 2-arc-shaped side plate; 21-positioning groove; 22-fastener mounting hole; 3-longitudinal partition; 31-narrow groove; 32-supporting part; 33-guide part; 4-screen bar; 41-straight section; 42-curved section; 421-ascending section; 422-descending section; 5-middle support plate; 51-support groove. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0027] In the present invention, unless otherwise stated, directional terms such as "upper, lower, left, right" generally refer to the upper, lower, left, and right shown in the accompanying drawings; "inner and outer" refer to the inner and outer relative to the outline of each component itself. In order to clearly describe the relative positional relationship of each component or structure, the present invention adopts directional terms such as "radial", "circumferential" and "longitudinal", which respectively correspond to the radial, circumferential and axial directions (or parallel to the axial direction) of the threshing device with a threshing drum, that is, Figures 1 to 3 As shown, the concave screen is usually formed into a grid shape with a substantially arc-shaped cross section, and the threshing drum can be rotatably arranged on the inner side of the concave screen, whereby the direction passing through the axis of the threshing drum in the radial plane is the "radial direction", the circumferential direction around the axis of the threshing drum is the "circumferential direction", and the extension direction of the axis of the threshing drum or the direction parallel to it is the "longitudinal direction". On this basis, the "radial inner side" refers to the side of the corresponding component facing the axis of the threshing drum, and the corresponding component is arranged at least partially around the axis of the threshing drum or around the axis of the threshing drum.

[0028] Reference Figures 1 to 6As shown, a concave plate screen according to a preferred embodiment of the utility model includes a supporting frame and a plurality of longitudinal partitions 3 and a plurality of screen bars 4 connected to the supporting frame and extending alternately to form a grid, each of the longitudinal partitions 3 is respectively formed with a plurality of narrow grooves 31 spaced apart from each other, each screen bar 4 extends through the narrow groove 31 and the portion between two adjacent narrow grooves 31 protrudes radially inward.

[0029] Thus, the screen bars 4 of the concave screen are formed into a non-circular arc shape with concave and convex variations, such as Figure 6 As shown. During the rotation of the threshing drum, the crop straw can be repeatedly rubbed, squeezed and combed between the threshing drum and the concave screen, thereby becoming soft and loose, which is not only conducive to maintaining the integrity of the straw, but also can promote secondary threshing, thereby improving the grain separation rate, while reducing the amount of broken straw and weeds carried in the separated grains. In addition, by extending the screen bar 4 through the narrow slot 31 of the longitudinal partition 3, the step between the screen bar 4 and the longitudinal partition 3 can be reduced or eliminated, thereby reducing the shear force and impact force on the straw and the grain, avoiding the straw from being torn and broken, and further reducing the amount of broken straw and weeds carried in the separated grains, while reducing the risk of the grains being broken or surface damage, thereby maintaining a low grain breakage rate and loss rate.

[0030] In the illustrated preferred embodiment, the support frame includes a pair of connecting plates 1 and a pair of arc-shaped side plates 2. The connecting plate 1 serves as the main skeleton of the concave plate screen, serves as the supporting base of other parts, and is used to connect the concave plate screen to other parts of the separation system. A pair of connecting plates 1 are arranged parallel to each other, and the arc-shaped side plates 2 are respectively in the shape of arc plates, and are respectively connected to the ends of the connecting plates 1 at their respective ends to form the peripheral frame of the concave plate screen. The inner circumference of the arc-shaped side plate 2 corresponds to the rotation profile of the threshing drum, and the diameter is larger than the rotation profile of the threshing drum, and the crop straw can be transported to the gap between the arc-shaped side plate 2 and the threshing drum. The arc-shaped side plate 2 can also be used to make two or more concave plate screens axially connected to each other, and for this purpose, fastener mounting holes 22 for fasteners such as bolts to pass through can be formed thereon. Both ends of each longitudinal partition 3 are respectively connected to the arc-shaped side plate 2, and each screen bar 4 extends through the longitudinal partition 3 and is respectively connected to the connecting plate 1 at both ends, thereby, the screen bars 4 and the longitudinal partitions 3 are staggered to form a (rectangular) grid to allow the grains falling off the straw to pass through the grid into the cleaning system.

[0031] Combination Figure 6As shown, the screen bar 4 has a plurality of straight segments 41 and a plurality of curved segments 42 which are alternately distributed with each other, wherein the straight segment 41 is embedded in the narrow groove 31 of the longitudinal partition 3, and the curved segment 42 is formed by the portion of the screen bar 4 located between two adjacent narrow grooves 31 protruding toward the radial inside, so as to protrude toward the radial inside (i.e., toward the direction where the threshing drum is located) relative to the straight segment 41 and extend smoothly, i.e., there are no sharp edges on the curved segment 42.

[0032] During the rotation of the threshing drum, the crop straw can be repeatedly rubbed, squeezed and combed between the threshing drum and the concave screen, so as to become soft and loose, which is not only conducive to maintaining the integrity of the straw, but also can promote secondary threshing, thereby improving the grain separation rate, while reducing the amount of broken straw and weeds carried in the separated grains. In addition, by embedding the straight section 41 of the screen bar 4 into the narrow groove 31 of the longitudinal partition 3, the step between the screen bar 4 and the longitudinal partition 3 can be reduced or eliminated, thereby reducing the shear force and impact force on the straw and the grain, avoiding the straw from being torn and broken, further reducing the amount of broken straw and weeds carried in the separated grains, and reducing the risk of the grains being broken or surface damaged, thereby maintaining a low grain breakage rate and loss rate.

[0033] The above-mentioned screen bar 4 can be formed by bending circular cross-section steel, and its concave-convex structure can make the crop straw be kneaded during the circular motion, thereby promoting the separation of grains through repeated squeezing and softening. In a preferred embodiment, the curved section 42 of the screen bar 4 can be divided into an ascending section 421 and a descending section 422, wherein, along the rotation direction of the threshing drum in the concave screen, the ascending section 421 extends from the straight section 41 toward the radial inside, and the descending section 422 extends from the ascending section 421 to another straight section 41 downstream. In the assembled state, the portion between the ascending section 421 and the descending section 422 forms a raised vertex of the curved section 42 that protrudes radially inward. Figure 3 and Figure 6 In the perspective shown, the threshing drum rotates in a counterclockwise direction relative to the concave screen; Figure 1 and Figure 2 In the perspective shown, the threshing drum rotates clockwise relative to the concave screen. The length of the descending section 422 of the screen bar 4 is shorter than the length of the ascending section 421, so that the convex apex of the curved section 42 is closer to another straight section 41 located downstream. Therefore, when the crop straw moves through the relatively gentle ascending section 421, the extrusion force applied thereto can be gradually increased until it passes over the convex apex and softens when passing through the descending section 422, so as to reduce the risk of grains being broken and surface damage, thereby further reducing the grain breakage rate and loss rate.

[0034] In the concave screen of the utility model, the above-mentioned components and the intermediate support plate 5 described later can be welded to each other as a whole. The connecting plate 1 can be bent to have a U-shaped cross-section to have a higher strength and facilitate connection to other parts of the separation system. The inner bending edge of the connecting plate 1 can be formed with a plurality of connecting grooves 11, and the two ends of the screen bar 4 can be embedded in the connecting groove 11 and connected as a whole by welding or the like. In order to reduce the edges and corners on the inner side of the concave screen so as to reduce the risk of grain breakage, the part of the screen bar 4 embedded in the connecting groove 11 is flush with the surface of the connecting plate 1 facing the threshing drum, and the part embedded in the narrow groove 31 (i.e., the straight section 41) is flush with the surface of the longitudinal partition 3 facing the threshing drum (i.e., the top surface of its support portion 32 described later) to jointly constitute the kneading surface of the concave screen.

[0035] Similarly, the inner peripheral edge of the arc-shaped side plate 2 may also be formed with a plurality of positioning grooves 21 spaced apart from each other along the circumferential direction, and both ends of each longitudinal partition 3 are respectively embedded in the positioning grooves 21 and are flush with the radial inner side of the arc-shaped side plate 2. Figure 1 and Figure 3 As shown, on the inner side of the concave screen, except for the curved section 42 of the screen bar 4, the connecting plate 1, the arc-shaped side plate 2, the longitudinal partition plate 3 and the straight section 41 of the screen bar 4 are generally on the same circumferential surface, which significantly reduces the edges and steps that may come into contact with the crop straw, thereby reducing the possibility of the straw and grains being broken, reducing the amount of broken straw and weeds carried in the separated grains, and reducing the risk of the grains being broken or having surface damage, thereby avoiding the crushing and loss of grains caused by the use of non-arc-shaped screen bars 4.

[0036] Typically, the longitudinal partitions 3 may be arranged to extend in a direction parallel to the connecting plate 1 and perpendicular to the sections of the screen bars 4, respectively, so that they are staggered to form a rectangular grid.

[0037] In a more preferred embodiment of the present invention, Figure 1 , Figure 2 and Figure 5 As shown, the longitudinal partition 3 can be formed to include a support portion 32 and a guide portion 33 having an angle with each other, the narrow groove 31 is opened in the support portion 32, and the support portion 32 is bent relative to the guide portion 33 along the rotation direction of the threshing drum in the concave screen. Figure 1 In the perspective shown, the threshing drum rotates clockwise, and the support portion 32 of the longitudinal partition 3 extends from its guide portion 33 to the left side of the figure. Through this arrangement, the grains falling from the straw can be guided to fall downward into the cleaning system without splashing around, thereby further reducing damage to the grains. Among them, the support portion 32 and the guide portion 33 can have an angle of 90°, and the edges adjacent to each other are in a circular arc transition.

[0038] Further, refer to Figure 2 and Figure 4 As shown, the concave plate screen of the present invention may also include an intermediate support plate 5, the two ends of which are respectively connected to the middle part of the length direction of the connecting plate 1, so as to improve the overall strength of the concave plate screen and support the longitudinal partition 3. Among them, the intermediate support plate 5 can be arranged to extend in parallel with the arc-shaped side plate 2, and a plurality of support grooves 51 spaced from each other are formed on the radial inner side. The guide portion 33 of the longitudinal partition 3 can be embedded in the support groove 51, so that the support portion 32 is supported on the radial inner side of the intermediate support plate 5. It can be understood that, although the figure shows only one intermediate support plate 5, the concave plate screen of the present invention can also be arranged to have multiple intermediate support plates 5.

[0039] On this basis, the utility model also provides a threshing device including the above-mentioned concave plate screen and a threshing drum rotatably arranged on the inner side of the concave plate screen. During the operation of the threshing device, the threshing drum drives the mixture of straw and grain to make a circular motion. When the straw passes through the kneading surface and the combing and brushing grid composed of the longitudinal partition 3 and the screen bar 4, it is repeatedly kneaded, squeezed and combed, thereby making the straw soft and loose, which can not only maintain the integrity of the straw as much as possible, but also promote secondary threshing, and also facilitate the separation of grains. Under the action of the guide strips on the drum cover and the roller rod teeth, the straw moves axially along the threshing drum. In this process, the grains and a small amount of broken straw are separated along the sieve grid of the concave plate screen under the action of centrifugal force and enter the cleaning system below; the long straw is finally discharged axially from the threshing device.

[0040] In addition, the utility model also provides a harvesting machine including the above-mentioned threshing device, such as a wheat harvester, a rice harvester or a corn harvester.

[0041] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

[0042] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A concave plate screen, characterized in that: The invention comprises a supporting frame, and a plurality of longitudinal partitions (3) and a plurality of screen bars (4) connected to the supporting frame and extending in an interlaced manner to form a grid, wherein each of the longitudinal partitions (3) is respectively formed with a plurality of narrow grooves (31) spaced apart from each other, and the screen bars (4) extend through the narrow grooves (31) and protrude radially inward at a portion between two adjacent narrow grooves (31).

2. The concave plate screen according to claim 1, characterized in that: The support frame comprises a pair of connecting plates (1) arranged in parallel with each other and a pair of arc-shaped side plates (2) respectively connected to the two ends of the connecting plates (1); the two ends of the longitudinal partition plate (3) are respectively connected to the arc-shaped side plates (2); the two ends of the arc-shaped side plates (2) are respectively connected to the connecting plates (1); the screen bar (4) is formed by bending circular cross-section steel and comprises a plurality of straight line segments (41) embedded in the narrow groove (31); the portion of the screen bar (4) between two adjacent narrow grooves (31) protrudes toward the radial inner side to form a smoothly extending curved segment (42).

3. The concave plate screen according to claim 2, characterized in that: Along the rotation direction of the threshing drum in the concave screen, the curved section (42) comprises an ascending section (421) extending from the straight section (41) toward the radial inside and a descending section (422) extending from the ascending section (421) toward another adjacent straight section (41), wherein the length of the descending section (422) is smaller than the length of the ascending section (421), so that the convex vertex of the curved section (42) is closer to another straight section (41) located downstream.

4. The concave plate screen according to claim 2, characterized in that: The connecting plate (1) has a U-shaped cross section, and the inner bending edge of the connecting plate (1) forms a plurality of connecting grooves (11), and the two ends of the screen bar (4) are respectively embedded in the connecting grooves (11).

5. The concave plate screen according to claim 4, characterized in that: The portion of the screen bar (4) embedded in the connecting groove (11) and the narrow groove (31) is flush with the surface of the connecting plate (1) and the longitudinal partition plate (3) facing the threshing drum.

6. The concave plate screen according to claim 2, characterized in that: A plurality of positioning grooves (21) spaced apart from each other in the circumferential direction are formed on the radial inner side of the arc-shaped side plate (2), and the two ends of the longitudinal partition plate (3) are respectively embedded in the positioning grooves (21) and are flush with the radial inner side of the arc-shaped side plate (2).

7. The concave plate screen according to any one of claims 2 to 6, characterized in that: The longitudinal partition (3) comprises a supporting portion (32) and a guiding portion (33) which are at an angle to each other, the narrow groove (31) is provided in the supporting portion (32), and the supporting portion (32) is bent relative to the guiding portion (33) along the rotation direction of the threshing drum in the concave screen.

8. The concave plate screen according to claim 7, characterized in that: It also includes an intermediate support plate (5) whose two ends are respectively connected to the middle part of the length direction of the connecting plate (1), the intermediate support plate (5) extends in parallel with the arc-shaped side plate (2) and is provided with a plurality of support grooves (51) spaced from each other on the radial inner side, the guide portion (33) is embedded in the support groove (51) and enables the support portion (32) to be supported on the radial inner side of the intermediate support plate (5).

9. A threshing device, characterized in that: The invention comprises the concave plate screen according to any one of claims 1 to 8 and a threshing drum rotatably arranged inside the concave plate screen.

10. A harvesting machine, characterized in that: Comprising the threshing device according to claim 9.

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