Sowing apparatus and unmanned aerial vehicle thereof

Description

Spreading device and drone

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 4, 2023, with application number 202311135940.7 and application name “Spreading device and its drone”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of drones, and more specifically, to a spreading device with a hood brim and a drone thereof. Background Art

[0003] In modern agricultural production, the spreading of materials in granular or powdered form, such as seeds and fertilizers, is often necessary. With the continuous advancement of agricultural modernization and precision agriculture, the development of agricultural machinery has greatly facilitated agricultural modernization. By equipping drones with spreading systems, they can provide efficient and convenient methods for operations such as rice sowing and fertilization.

[0004] Currently, drone spreading systems primarily use centrifugal disks to throw material particles horizontally, creating a parabolic motion. The velocity and angle of the ejected material often result in excessively wide spreads and sparse material, leading to poor spreading results.

[0005] Summary of the Invention

[0006] The present application provides a spreading device and a UAV thereof, which, by setting a brim at a certain angle to the spreading disk, can limit the exit angle of the material, reduce the width, increase the density, and improve the spreading effect.

[0007] In a first aspect, a spreading device is provided, which includes: a material bin for storing materials, the materials being discharged from the material bin through a discharge unit connected to the material bin; a spreading plate located below the discharge unit and configured to rotate on a rotating plane to throw out the materials introduced by the discharge unit through centrifugal force; a driving device connected to the spreading plate and configured to drive the spreading plate to rotate; a brim, arranged above the spreading plate and shaped like a hollow cone, configured to rebound the thrown materials so that the material is spread with a width of R f When the height H of the spreading disc is 3 meters, the angle θ between the inner side of the brim and the horizontal plane conforms to the following relationship: R f =10.409θ 2 -16.058θ+8.9132.

[0008] In combination with the first aspect, in certain implementations of the first aspect, raised guide strips are provided on the spreading disc, and the guide strips are evenly distributed on the spreading disc.

[0009] According to the solution of the present application, the exit angle of the material can be limited, the width can be reduced, the density can be increased, and the spreading effect can be improved.

[0010] In the second aspect, a spreading device is provided, which includes: a material bin for storing materials, and the materials are discharged from the material bin through a discharge unit connected to the material bin; a spreading plate located below the discharge unit, and used to rotate on a rotating plane to throw out the materials introduced by the discharge unit through centrifugal force; a driving device connected to the spreading plate, and used to drive the spreading plate to rotate; a brim, which is arranged above the spreading plate and is shaped like a hollow cone, and is used to rebound the thrown materials so that the material is spread with a width of R f , the height of the spreading disc is H, when the sowing width is R f When the distance is set to 4 meters, the angle θ between the inner side of the brim and the horizontal plane meets the following relationship: H = -7.5195θ 3 +7.7016θ 2 +4.3058θ+0.4412.

[0011] In combination with the second aspect, in certain implementations of the second aspect, raised guide strips are provided on the spreading disc, and the guide strips are evenly distributed on the spreading disc.

[0012] According to a third aspect, a UAV is provided, which includes: a fuselage for providing flight power and controlling flight; a bracket arranged below the fuselage; a spreading device connected to the bracket; wherein the spreading device includes: a material bin for storing materials, the materials being discharged from the material bin through a discharge unit connected to the material bin; a spreading disc located below the discharge unit, for rotating in a rotating plane to throw out the materials introduced by the discharge unit through centrifugal force; a driving device connected to the spreading disc, for driving the spreading disc to rotate; a brim, arranged above the spreading disc, in the shape of a hollow cone, for rebounding the thrown materials so that the material spreading width is R f When the height H of the spreading disc is 3 meters, the angle θ between the inner side of the brim and the horizontal plane conforms to the following relationship: R f =10.409θ 2 -16.058θ+8.9132.

[0013] In combination with the third aspect, in certain implementations of the third aspect, raised guide strips are provided on the spreading disc, and the guide strips are evenly distributed on the spreading disc.

[0014] In a fourth aspect, a drone is provided, comprising: a fuselage for providing flight power and controlling flight; a bracket arranged below the fuselage; a spreading device connected to the bracket; wherein the spreading device comprises: a material bin for storing materials, the materials being discharged from the material bin through a discharge unit connected to the material bin; a spreading disc located below the discharge unit for rotating in a rotating plane to throw out the materials introduced by the discharge unit through centrifugal force; a driving device connected to the spreading disc for driving the spreading disc to rotate; a brim arranged above the spreading disc in the shape of a hollow cone for rebounding the thrown materials so that the material spreading width is R f , the height of the spreading disc is H, when the sowing width is R f When the distance is set to 4 meters, the angle θ between the inner side of the brim and the horizontal plane meets the following relationship: H = -7.5195θ 3 +7.7016θ 2 +4.3058θ+0.4412.

[0015] In combination with the fourth aspect, in certain implementations of the fourth aspect, raised guide strips are provided on the spreading disc, and the guide strips are evenly distributed on the spreading disc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a schematic diagram of a spreading device provided in an embodiment of the present application.

[0017] FIG2 is a schematic diagram of the structure of the brim and spreading plate provided in an embodiment of the present application.

[0018] FIG3 is a schematic diagram of material spreading analysis provided in an embodiment of the present application.

[0019] FIG4 is a schematic diagram of material rebound analysis provided in an embodiment of the present application.

[0020] FIG5 is a schematic diagram of a parabolic analysis of materials provided in an embodiment of the present application.

[0021] FIG6 is a diagram showing a fitting relationship between a hat brim bottom angle and a spreading height provided in an embodiment of the application.

[0022] FIG. 7 is another diagram showing the relationship between the bottom angle of the brim and the spreading height provided in an embodiment of the application. DETAILED DESCRIPTION

[0023] The technical solution in this application will be described below with reference to the accompanying drawings.

[0024] The terms "including" and "having" and any variations thereof in the embodiments of the present application shown below are intended to cover non-exclusive inclusions, for example, a system, product or device comprising a series of units is not necessarily limited to those units explicitly listed, but may include other units not explicitly listed or inherent to these products or devices.

[0025] In the embodiments of this application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations, or descriptions. An embodiment or design described as "exemplarily" or "for example" should not be construed as being more preferred or advantageous than other embodiments or designs. The use of words such as "exemplarily" or "for example" is intended to present related concepts in a concrete manner to facilitate understanding.

[0026] FIG1 is a schematic diagram of a spreading device 100 provided in an embodiment of the present application.

[0027] As shown in FIG1 , the spreading device comprises at least:

[0028] The material warehouse 110 is used to store materials.

[0029] It should be understood that the material can be solid particles such as seeds, fertilizers, feed or pesticides, and this application does not limit this.

[0030] The embodiment of the present application does not limit the shape, size, and material of the material bin 110. Those skilled in the art can select or design according to actual needs. For example, the upper part of the material bin 110 can be barrel-shaped, the bottom can be in the shape of an inverted funnel, and can be made of a plastic material with stable performance, not easy to deform, and light weight. In another example, the upper part of the material bin 110 can be box-shaped, the bottom can be in the shape of an inverted funnel, and the material can be a metal material with high strength and stable performance.

[0031] The unloading unit 120 is connected to the material bin 110 , and the material in the material bin 110 is discharged from the material bin through the unloading unit 120 .

[0032] It should be understood that in some embodiments, the unloading unit can be integrated with the material bin, or it can be arranged as a separate component below the material bin. However, the materials will be discharged from the material bin through the unloading unit, and the specific arrangement of the unloading unit is not limited in the embodiments of the present application.

[0033] In some embodiments, a regulating valve may be provided in the unloading unit, and the regulating valve is used to adjust the amount and speed of the material passing through.

[0034] As shown in FIG2 , the spreading disc 130 is located below the unloading unit 120 and can rotate on a rotation plane to throw out the material introduced by the unloading unit through centrifugal force.

[0035] The spreading disc 130 is provided with raised guide strips which are evenly distributed on the spreading disc.

[0036] For example, the guide strips may be straight protrusions, which are arranged along the radius of the circle of the spreading disc and are evenly distributed around the center of the circle.

[0037] As another example, the guide strips may be curved strip-shaped protrusions that are centrally symmetrically distributed around the center of the spreading disc.

[0038] The driving device 140 is connected to the spreading disc 130 to drive the spreading disc 130 to rotate.

[0039] It should be understood that the driving device can be arranged above or below the spreading disc and connected to the spreading disc through a transmission structure. This application does not limit the location and manner of setting the driving device.

[0040] The rotation of the spreading disc generates centrifugal force, which throws the solid granular material that falls on the spreading disc out of the spreading disc in a centrifugal manner. Due to the gravity of the material itself, the centrifugal force, the upward reaction force of the spreading disc on the particles and the supporting force of the guide strip, the solid material in the spreading disc is thrown out under the action of centrifugal force.

[0041] For example, the material of the spreading disc 130 is not limited, and those skilled in the art can select or design it according to actual needs. In some embodiments, the spreading disc 130 can be disc-shaped and made of metal. In other embodiments, the spreading disc 130 can also be made of plastic.

[0042] It should be understood that the material is thrown out by the spreading disc in a parabolic motion, and the material's ejection speed and angle often result in the material width being too large and the material being sparse. Therefore, this application proposes a spreading device that limits the ejection angle, reduces the width, and increases the spreading density by adding a brim to the spreader.

[0043] The brim 150 is arranged above the spreading plate 130 and is in the shape of a hollow cone, which is used to rebound the thrown material so that the material is spread with a width of R f When the spreading disc height H is 3 meters, the angle θ between the inner side of the brim and the horizontal plane conforms to the following relationship: R f =10.409θ 2 -16.058θ+8.9132.

[0044] The brim can be installed by being clipped onto the bracket, connected to the bracket by bolts, connected to the bracket by hinges, or other connection methods, which are not limited in this application.

[0045] It should be understood that in the embodiments of the present application, the brim may also be referred to as a baffle, a reflector, etc., and the present application does not limit this.

[0046] The bottom angle θ of the brim can be adjusted as needed, which is suitable for situations where frequent adjustments to the sowing width are required. The adjustable brim consists of two parts: one is a bracket fixed around the spinning disc, and the other is the brim that can be adjusted at any time. The sowing width can be controlled by adjusting the angle of the brim.

[0047] Generally speaking, if you want to reduce the sowing width, you can adjust the bottom angle of the brim to a larger angle, thereby limiting the range of material spread by the sowing disc. If you want to increase the sowing width, you can adjust the bottom angle of the brim to a smaller angle, thereby expanding the range of material spread by the sowing disc.

[0048] According to the embodiment provided in the present application, by providing a brim at a certain angle to the spreading disc surface, the exit angle of the material can be limited, the spreading width can be reduced, the spreading density can be increased, and the spreading effect can be improved.

[0049] An embodiment of the present application provides a drone.

[0050] It should be understood that the UAV may be a rotary-wing UAV, a fixed-wing UAV, an unmanned helicopter, or a fixed-wing-rotor hybrid UAV. Rotary-wing UAVs include multi-rotor UAVs. Multi-rotor UAVs include two-rotor UAVs, four-rotor UAVs, six-rotor UAVs, eight-rotor UAVs, ten-rotor UAVs, or twelve-rotor UAVs. The UAV may also communicate wirelessly or wired with a control terminal, thereby enabling control of the UAV via the control terminal.

[0051] The UAV includes a fuselage for providing flight power and controlling flight.

[0052] The bracket is set under the fuselage.

[0053] It should be understood that the fuselage is the structural carrier of the drone, used to install control components such as the flight control motherboard and parts such as batteries, thereby providing flight power and controlling flight direction, angle, and altitude. At the same time, the bracket used to support the drone's takeoff and landing can be fastened to the lower part of the fuselage with screws. The bracket can be a fixed tripod that is open during the drone's flight operation to allow for landing at any time. Other accessories required for the drone can also be fixedly installed on the bracket. This application does not limit the configuration of the drone fuselage and bracket.

[0054] The spreading device is connected to the bracket.

[0055] It should be understood that the spreading device is the spreading device in the above embodiment, and reference may be made to the above description, which will not be repeated here.

[0056] As shown in Figure 3, after the material falls on the spreader, it is pulled by the spreader to make a circular motion. When it leaves the spreader, the motion speed can be decomposed into the tangential speed Vt and the radial speed Vr, and the angle with the tangential direction is α.

[0057] The angular velocity of the spreading disc is ω and the radius is R s , the tangential velocity V of the material leaving the spreading disct : V t =ωR s .

[0058] As shown in Figure 3, the radial velocity is analyzed in a non-inertial system. The material moves radially along the guide strips on the spreading disc. In the tangential direction of the circle, the material is subjected to the Coriolis force F c and the supporting force N of the guide bar, and N=F co In the radial direction, the material is subjected to the centrifugal force F ce The material accelerates in the radial direction due to the friction force f. Assuming that the radius of the point where the material falls on the spreader is r and friction is not considered, the radial velocity of the material when it leaves the spreader is:

[0059] The ejection velocity V of the material leaving the spreading disc is:

[0060] As shown in Figure 4, the material flies out of the spinner and flies towards the brim of the hat, and hits the brim of the hat. The radius of the impact point is R m The angle between the impact velocity and the projection of the normal line of the brim surface on the XY plane can be calculated:

[0061] As shown in Figure 5, when the material bounces off the brim, it will perform parabolic motion with an initial velocity of V and an angle with the horizontal plane of At this time, it falls to the ground under the influence of gravity and air resistance. Corresponding to different initial vertical heights H, different sowing widths R can be obtained. f .

[0062] Let the acceleration due to gravity be g, and assume that the material is spherical with a diameter of d and a density of ρ. Then, the air resistance coefficient at 25°C and standard atmospheric pressure is Then the material trajectory parameter equation can be obtained to calculate the flight trajectory and landing point of the material after rebound:

[0063] The material hits the brim and rebounds. Without considering the energy loss during the rebound process, the reflection speed is equal to the incident speed. The direction of reflection is related to the bottom angle of the brim and the direction of the incident velocity. According to the reflection theorem, the bottom angle θ of the brim should conform to the following formula:

[0064] For example, the radius of the spreading disc is 0.12 meters, and the material is spread at a speed of 1000 revolutions per minute. The material density is 1000 kg / cubic meter, the material radius is 0.002 meters (for example, compound fertilizer), and the spreading height is 3 meters. According to the above method 200, the relationship between the bottom angle of the brim and the material spreading width can be calculated. Some results are listed in Table 1.

[0065] The material spreading width is the horizontal distance from the rebound point of the material on the brim to the ground.

[0066] Table 1. Relationship between the bottom angle of the hat brim and the broadcast width when the height H is 3 meters

[0067] As shown in Figure 6, fitting the data in Table 1, we can get: R f =10.409θ 2 -16.058θ+8.9132.

[0068] As another example, the radius of the spreading disc is 0.12 meters, and the material is spread at a speed of 1000 revolutions per minute. The material density is 1000 kg / cubic meter, the material radius is 0.002 meters (for example, compound fertilizer), and the sowing width is 3 meters. According to the above method 200, the relationship between the bottom angle of the brim and the height of the spreading disc can be calculated. Some results are listed in Table 2.

[0069] Table 2. Relationship between the bottom angle of the cap and the sowing height when the sowing width is 4 meters

[0070] As shown in FIG7 , the data in Table 2 are fitted to obtain: H = -7.5195θ 3 +7.7016θ 2 +4.3058θ+0.4412.

[0071] Therefore, the embodiment of the present application provides another spreading device.

[0072] The spreading device comprises at least:

[0073] Material warehouse, used to store materials.

[0074] It should be understood that the material can be solid particles such as seeds, fertilizers, feed or pesticides, and this application does not limit this.

[0075] The embodiments of the present application do not limit the shape, size, and material of the material bin. Those skilled in the art can select or design according to actual needs. For example, the upper part of the material bin can be barrel-shaped, the bottom can be in the shape of an inverted funnel, and can be made of a plastic material with stable performance, not easy to deform, and light weight. In another example, the upper part of the material bin can be box-shaped, the bottom can be in the shape of an inverted funnel, and the material can be a metal material with high strength and stable performance.

[0076] The unloading unit is connected to the material bin, and the material in the material bin is discharged from the material bin through the unloading unit.

[0077] It should be understood that in some embodiments, the unloading unit can be integrated with the material bin, or it can be arranged as a separate component below the material bin. However, the materials will be discharged from the material bin through the unloading unit, and the specific arrangement of the unloading unit is not limited in the embodiments of the present application.

[0078] In some embodiments, a regulating valve may be provided in the unloading unit, and the regulating valve is used to adjust the amount and speed of the material passing through.

[0079] The spreading disc is located below the unloading unit and can rotate on the rotating plane to throw out the material introduced by the unloading unit through centrifugal force.

[0080] The spreading disc is provided with raised guide strips which are evenly distributed on the spreading disc.

[0081] For example, the guide strips may be straight protrusions, which are arranged along the radius of the circle of the spreading disc and are evenly distributed around the center of the circle.

[0082] As another example, the guide strips may be curved strip-shaped protrusions that are centrally symmetrically distributed around the center of the spreading disc.

[0083] The driving device is connected with the spreading disc and drives the spreading disc to rotate.

[0084] It should be understood that the driving device can be arranged above or below the spreading disc and connected to the spreading disc through a transmission structure. This application does not limit the location and manner of setting the driving device.

[0085] The rotation of the spreading disc generates centrifugal force, which throws the solid granular material that falls on the spreading disc out of the spreading disc in a centrifugal manner. Due to the gravity of the material itself, the centrifugal force, the upward reaction force of the spreading disc on the particles and the supporting force of the guide strip, the solid material in the spreading disc is thrown out under the action of centrifugal force.

[0086] For example, there is no limitation on the material of the spreading disc, and those skilled in the art can select or design it according to actual needs. In some embodiments, the overall shape of the spreading disc can be disc-shaped, and the entire spreading disc can be made of metal. In other embodiments, the spreading disc can also be made of plastic.

[0087] It should be understood that the material is thrown out by the spreading disc in parabolic motion, and the material's ejection speed and angle often result in the material width being too large and the material being sparse. Therefore, this application proposes a spreading device that limits the ejection angle, reduces the width, increases the spreading density, and improves the spreading effect by adding a brim to the spreader.

[0088] The brim is set above the spreading plate and is in the shape of a hollow cone. It is used to rebound the thrown material so that the material's spreading width is R f , when the broadcast width is R f When the distance is 4 meters, the angle θ between the inner side of the brim and the horizontal plane meets the following relationship: H = -7.5195θ 3 +7.7016θ 2 +4.3058θ+0.4412.

[0089] According to the embodiment provided in the present application, when the sowing width is fixed, the bottom angle of the brim can be adjusted according to the sowing height, thereby limiting the exit angle of the material, reducing the width, and increasing the density.

[0090] An embodiment of the present application provides a drone.

[0091] It should be understood that the UAV may be a rotary-wing UAV, a fixed-wing UAV, an unmanned helicopter, or a fixed-wing-rotor hybrid UAV. Rotary-wing UAVs include multi-rotor UAVs. Multi-rotor UAVs include two-rotor UAVs, four-rotor UAVs, six-rotor UAVs, eight-rotor UAVs, ten-rotor UAVs, or twelve-rotor UAVs. The UAV may also communicate wirelessly or wired with a control terminal, thereby enabling control of the UAV via the control terminal.

[0092] The UAV includes a fuselage for providing flight power and controlling flight.

[0093] The bracket is set under the fuselage.

[0094] It should be understood that the fuselage is the structural carrier of the drone, used to install control components such as the flight control motherboard and parts such as batteries, thereby providing flight power and controlling flight direction, angle, and altitude. At the same time, the bracket used to support the drone's takeoff and landing can be fastened to the lower part of the fuselage with screws. The bracket can be a fixed tripod that is open during the drone's flight operation to allow for landing at any time. Other accessories required for the drone can also be fixedly installed on the bracket. This application does not limit the configuration of the drone fuselage and bracket.

[0095] The spreading device is connected to the bracket.

[0096] It should be understood that the spreading device is the spreading device in the above embodiment, and reference may be made to the above description, which will not be repeated here.

[0097] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0098] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0099] It should be understood that different embodiments can be used independently or in combination based on certain internal or external connections, and different implementation methods in the embodiments can be used independently or in combination.

[0100] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A spreading device, characterized in that: include: A material bin, used to store materials, the materials are discharged from the material bin through a material unloading unit connected to the material bin; A spreading plate, located below the material discharging unit, is used to rotate in a rotating plane to throw out the material introduced by the material discharging unit through centrifugal force; A driving device, connected to the spreading disc, and used to drive the spreading disc to rotate; The brim is arranged above the spreading plate and is in the shape of a hollow cone, which is used to rebound the thrown material so that the spreading width of the material is R f , when the height H of the spreading plate is 3 meters, the angle θ between the inner side of the brim and the horizontal plane meets the following relationship: R f =10.409θ 2 -16.058θ+8.9132.

2. The spreading device according to claim 1, characterized in that The spreading disc is provided with raised guide strips, and the guide strips are evenly distributed on the spreading disc.

3. A spreading device, characterized in that: include: A material bin, used to store materials, the materials are discharged from the material bin through a material unloading unit connected to the material bin; A spreading plate, located below the material discharging unit, is used to rotate in a rotating plane to throw out the material introduced by the material discharging unit through centrifugal force; A driving device, connected to the spreading disc, and used to drive the spreading disc to rotate; The brim is arranged above the spreading plate and is in the shape of a hollow cone, which is used to rebound the thrown material so that the spreading width of the material is R f , the height of the spreading disc is H, when the sowing width is R f When the distance is set to 4 meters, the angle θ between the inner side of the brim and the horizontal plane meets the following relationship: H=-7.5195θ 3 +7.7016θ 2 +4.3058θ+0.4412.

4. The spreading device according to claim 3, characterized in that The spreading disc is provided with raised guide strips, and the guide strips are evenly distributed on the spreading disc.

5. A drone, characterized in that: include: The fuselage is used to provide flight power and control flight; A bracket, arranged below the fuselage; a spreading device connected to the support; Wherein, the spreading device comprises: A material bin, used to store materials, the materials are discharged from the material bin through a material unloading unit connected to the material bin; A spreading plate, located below the material discharging unit, is used to rotate in a rotating plane to throw out the material introduced by the material discharging unit through centrifugal force; A driving device, connected to the spreading disc, and used to drive the spreading disc to rotate; The brim is arranged above the spreading plate and is in the shape of a hollow cone, which is used to rebound the thrown material so that the spreading width of the material is R f , when the height H of the spreading plate is 3 meters, the angle θ between the inner side of the brim and the horizontal plane meets the following relationship: R f =10.409θ 2 -16.058θ+8.9132.

6. The drone according to claim 5, characterized in that: The spreading disc is provided with raised guide strips, and the guide strips are evenly distributed on the spreading disc.

7. A drone, characterized in that: include: The fuselage is used to provide flight power and control flight; A bracket, arranged below the fuselage; a spreading device connected to the support; Wherein, the spreading device comprises: A material bin, used to store materials, the materials are discharged from the material bin through a material unloading unit connected to the material bin; A spreading plate, located below the material discharging unit, is used to rotate in a rotating plane to throw out the material introduced by the material discharging unit through centrifugal force; A driving device, connected to the spreading disc, and used to drive the spreading disc to rotate; The brim is arranged above the spreading plate and is in the shape of a hollow cone, which is used to rebound the thrown material so that the spreading width of the material is R f , the height of the spreading disc is H, when the sowing width is R f When the distance is set to 4 meters, the angle θ between the inner side of the brim and the horizontal plane meets the following relationship: H=-7.5195θ 3 +7.7016θ 2 +4.3058θ+0.4412.

8. The drone according to claim 7, characterized in that: The spreading disc is provided with raised guide strips, and the guide strips are evenly distributed on the spreading disc.

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