CN114982456B

CN114982456B - Efficient sweet potato harvester suitable for southern plain soil

Info

Publication number: CN114982456B
Application number: CN202210699933.9A
Authority: CN
Inventors: 宋渊明; 肖兴; 宋明成; 赵英杰
Original assignee: Chongqing Three Gorges University
Current assignee: Chongqing Three Gorges University
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2023-07-07
Anticipated expiration: 2042-06-20
Also published as: CN114982456A

Abstract

The invention discloses a high-efficiency sweet potato harvester suitable for southern flat soil, which comprises a vine cutting mechanism, an excavating mechanism and a collecting mechanism which are arranged in series, wherein the vine cutting mechanism comprises a vine cutting knife, a front travelling wheel and a vine cutting box; the excavating mechanism comprises an excavating knife, an excavating box and a conveying roller; the collecting mechanism comprises an upper storage box, a lower storage box and a rear travelling wheel arranged at the bottom of the lower storage box, wherein the upper storage box and the lower storage box are arranged in a lap joint manner; the rear end of the rattan cutting box is provided with a conveying opening, and the conveying opening is communicated with the upper storage box through a conveying belt; the excavating box is installed between the vine cutting mechanism and the collecting mechanism through a support, the excavating box is obliquely arranged, the bottom end of the excavating knife is lower than the front travelling wheel and the rear travelling wheel, and the rear end of the excavating box is communicated with the lower storage box. According to the invention, the rattan cutting mechanism, the digging mechanism and the collecting mechanism are arranged in series, so that rattan cutting, digging and collecting are integrally designed, classification harvesting and storage of sweet potato vines and tuberous roots are realized, subsequent manual separation is not needed, and the operation efficiency is greatly improved.

Description

Efficient sweet potato harvester suitable for southern plain soil

Technical Field

The invention relates to a high-efficiency sweet potato harvester suitable for southern plain soil, and belongs to the technical field of sweet potato harvesters.

Background

Sweet potato, a perennial herb, has round, oval or spindle-shaped tuberous root in the underground part, is one of the main grains in China, and is planted in most areas of China, such as Chongqing, sichuan, gansu, ningxia, hebei, henan and the like. In recent years, sweet potatoes enter the life of people in a commodity mode, and are sold in large quantities in first-line cities such as North Guangshen and the like. Because edible part of sweet potato buries underground, in the softer region of soil property, peasant can be with its harvesting efficiency higher of pulling out from underground easily, and in the harder region of geology, when pulling out, sweet potato vine is broken easily, and sweet potato still is located underground, need use instrument such as hoe to excavate it, waste time and energy and damage sweet potato easily.

Among them, sweet potato harvesters designed by lockwood corporation in the united states are very successful examples, and are classified into two types according to the design structure, one is a direct loading type harvester: the harvester is characterized in that the loading lifting arm is longer, and the sweet potatoes can be treated very cleanly when being transported for a long time frequently; the other is a van-type sweet potato harvester: a plurality of loading compartments are distributed on both sides of the machine, and the operator can precisely control the various parts and operating parameters. In China, the development of the sweet potato harvester is still in a starting stage, on one hand, planting is not large-scale, the development of the machine is hindered, on the other hand, the existing harvester digs out the tuberous roots and the vines of the sweet potatoes together, only the soil is screened out, and the digged sweet potatoes are required to be processed in batches by workers later, so that the working efficiency is low and the labor input is large.

Disclosure of Invention

The invention aims to provide a high-efficiency sweet potato harvester suitable for southern plain soil, which solves the problems that in the prior art, the sweet potato harvester cannot automatically separate sweet potato tuberous roots and vines, and needs manual separation and has low efficiency.

In order to achieve the above purpose, the invention adopts the following technical scheme: the utility model provides a high-efficient sweet potato harvester suitable for southern plain soil, includes rattan cutting mechanism, excavation mechanism and the collection mechanism that sets up in series, rattan cutting mechanism includes rattan sword, front travelling wheel and rattan case, rattan case front end is uncovered to be set up, rattan sword installs in the open bottom in rattan case front end, front travelling wheel is located rattan case bottom;

the excavating mechanism comprises an excavating knife, an excavating box and conveying rollers, wherein the excavating knife is arranged at the bottom of an opening at the front end of the excavating box, and a plurality of conveying rollers are arranged at the bottom of the excavating box;

the collecting mechanism comprises an upper storage box, a lower storage box and a rear travelling wheel arranged at the bottom of the lower storage box, wherein the upper storage box and the lower storage box are arranged in a lap joint manner;

the rear end of the rattan cutting box is provided with a conveying opening, and the conveying opening is communicated with the upper storage box through a conveying belt;

the excavating box is installed between the vine cutting mechanism and the collecting mechanism through a support, the excavating box is obliquely arranged, the bottom end of the excavating knife is lower than the front travelling wheel and the rear travelling wheel, and the rear end of the excavating box is communicated with the lower storage box.

Further, the rattan cutting knife comprises a fixed knife rest and a movable knife rest which are overlapped, the movable knife rest reciprocates along the length direction of the rattan cutting knife, the fixed knife rest and the movable knife rest are respectively provided with a plurality of blades in an array along the length direction of the rattan cutting knife, and the angle between the blades and the length direction of the rattan cutting knife is alpha, and the angle between the blades and the length direction of the rattan cutting knife is more than 0 degrees and less than 180 degrees.

Further, one end of the movable knife rest is movably inserted into the side wall of the rattan cutting box, the other end of the movable knife rest is provided with a U-shaped bayonet, a rotating shaft is arranged on the rattan cutting box, an annular cam is arranged on the periphery of the rotating shaft and is embedded into the U-shaped bayonet, and an included angle between the annular cam and the axis of the rotating shaft is beta, and 0 degrees is more than or equal to beta and less than 90 degrees, and 90 degrees is more than or equal to beta and less than 180 degrees.

Further, a rattan picking rotating shaft and a rattan crushing rotating shaft are arranged in the rattan cutting box, the rattan picking rotating shaft is located above the rattan cutting knife and circumferentially provided with a plurality of rattan picking levers, the rattan crushing rotating shaft is located above the rattan picking rotating shaft and circumferentially provided with a plurality of rattan crushing knives, and the rattan cutting knife, the rattan picking rotating shaft and the rattan crushing rotating shaft are arranged in a stepped mode.

Further, the rattan lever includes a long lever and a short lever, and the long lever has a joint portion at a front end thereof, the joint portion being curved in a rotational direction.

Further, the conveyer belt, the rotating shaft, the rattan picking rotating shaft and the rattan crushing rotating shaft are connected through a plurality of conveyer belts, and one of the conveyer belt, the rotating shaft, the rattan picking rotating shaft and the rattan crushing rotating shaft is connected with a driving motor.

Further, the bottom of the front end of the excavating box is provided with a plurality of excavating knives which are arranged along the travelling direction of the harvester, and a gap for soil to pass through is reserved between the two excavating knives.

Further, a relief hole for the soil to pass through is reserved among the plurality of conveying rollers.

Further, the plurality of conveying rollers are driven by one linear motor.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the invention is suitable for a high-efficiency sweet potato harvester for southern flat soil, and is designed to integrate vine cutting, digging and collecting through a vine cutting mechanism, a digging mechanism and a collecting mechanism which are arranged in series, vine cutting knives are used for firstly cutting vines, conveying the vines to an upper storage box at the rear for storage through a conveying belt, then digging out a root tuber part without vine tissues through the digging knives, and conveying the root tuber part to a lower storage box, thereby realizing classification harvesting and storage of sweet potato vines and root tuber without subsequent manual separation, and greatly improving the operation efficiency.

2. The invention is suitable for the high-efficiency sweet potato harvester for the southern flat soil, and the annular cam which forms a non-right angle with the rotating shaft of the rotating shaft enables the contact part of the annular cam and the U-shaped bayonet to drive the U-shaped bayonet to reciprocate along the axis direction of the rotating shaft when the annular cam rotates, so that the rattan cutter can cut the rattan uninterruptedly.

3. The invention is suitable for the high-efficiency sweet potato harvester for the soil in the southern plain land, the rattan vine is further crushed by the cooperation of the rattan picking lever and the rattan crushing cutter, the rattan vine is prevented from being blocked on the rattan cutting cutter part, the subsequent use of the rattan cutting cutter is influenced, and meanwhile, the crushed rattan vine can be transmitted towards the direction of the conveying belt, so that the rattan vine harvester is convenient to collect.

4. The invention is suitable for the high-efficiency sweet potato harvester for the southern flat soil, and the soil mixed on the sweet potato tubers can pass through the gap and the abdication holes to separate from the sweet potatoes through the reserved gap between the digging knives and the abdication holes between the conveying rollers, so that the harvesting quality of the sweet potatoes is prevented from being influenced.

5. The invention is suitable for the high-efficiency sweet potato harvester for the southern flat soil, and is connected with the conveyor belt, the vine cutting knife, the vine picking rotating shaft and the vine crushing rotating shaft through the conveyor belt, and the driving motor is used for driving, so that the conveyor belt, the vine cutting knife, the vine picking rotating shaft and the vine crushing rotating shaft can be linked, synchronous work can be realized, the treatment efficiency is improved, the number of motors can be reduced, and the cost is saved.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a high-efficiency sweet potato harvester suitable for southern plain soil;

FIG. 2 is a top view of the vine cutting box portion;

FIG. 3 is a schematic view of the structure at the rotation axis;

fig. 4 is a top view of the excavating mechanism portion.

In the figure: 1. a vine cutting mechanism; 11. a vine cutter; 111. fixing the tool rest; 112. a movable tool rest; 113. a blade; 114. a U-shaped bayonet; 12. a front walking wheel; 13. a rattan cutting box; 131. a transfer port; 132. a rotating shaft; 133. a ring cam; 14. a rattan rotating shaft; 141. a rattan lever; 142. a long rod; 143. a short bar; 144. a picking part; 15. a rattan crushing rotating shaft; 151. rattan knife; 2. an excavating mechanism; 21. a digging knife; 211. a gap; 22. an excavating box; 23. a conveying roller; 231. a relief hole; 232. a linear motor; 3. a collection mechanism; 31. an upper storage box; 32. a lower storage tank; 33. a rear walking wheel; 4. a conveyor belt; 5. a bracket; 6. a transmission belt; 61. and driving the motor.

Detailed Description

Example 1: referring to fig. 1-4, the high-efficiency sweet potato harvester suitable for southern plain soil comprises a rattan cutting mechanism 1, an excavating mechanism 2 and a collecting mechanism 3 which are arranged in series, wherein the rattan cutting mechanism 1 comprises a rattan cutting blade 11, a front travelling wheel 12 and a rattan cutting box 13, the front end of the rattan cutting box 13 is arranged in an open mode, the rattan cutting blade 11 is arranged at the bottom of the front end opening of the rattan cutting box 13, and the front travelling wheel 12 is positioned at the bottom of the rattan cutting box 13;

the excavating mechanism 2 comprises an excavating knife 21, an excavating box 22 and conveying rollers 23, wherein the excavating knife 21 is arranged at the bottom of the front end opening of the excavating box 22, and a plurality of conveying rollers 23 are arranged at the bottom of the excavating box 22;

the collecting mechanism 3 comprises an upper storage box 31, a lower storage box 32 and a rear travelling wheel 33 which are arranged at the bottom of the lower storage box 32 in a lap joint manner;

the rear end of the rattan cutting box 13 is provided with a conveying opening 131, and the conveying opening 131 is communicated with the upper storage box 31 through a conveying belt 4;

the excavating box 22 is installed between the vine cutting mechanism 1 and the collecting mechanism 3 through the support 5, the excavating box 22 is obliquely arranged, the bottom end of the excavating knife 21 is lower than the front travelling wheel 12 and the rear travelling wheel 33, and the rear end of the excavating box 22 is communicated with the lower storage box 32.

The rattan cutter 11 comprises a fixed cutter rest 111 and a movable cutter rest 112 which are overlapped, the movable cutter rest 112 reciprocates along the length direction of the fixed cutter rest 111 and the movable cutter rest 112, a plurality of blades 113 are respectively arranged in an array manner along the length direction of the fixed cutter rest 111 and the movable cutter rest 112, and the angle between the blades 113 and the length direction of the cutter rest is alpha, 0 degrees < alpha < 180 degrees.

One end of the movable knife rest 112 is movably inserted into the side wall of the rattan cutting box 13, the other end of the movable knife rest is provided with a U-shaped bayonet 114, a rotating shaft 132 is arranged on the rattan cutting box 13, an annular cam 133 is arranged on the periphery of the rotating shaft 132, the annular cam 133 is embedded in the U-shaped bayonet 114, and an included angle between the annular cam 133 and the axis of the rotating shaft 132 is beta, wherein beta is more than 0 degrees and less than 90 degrees, and beta is more than 90 degrees and less than 180 degrees.

The rattan cutting box 13 is internally provided with a rattan picking rotating shaft 14 and a rattan crushing rotating shaft 15, the rattan picking rotating shaft 14 is positioned above the rattan cutting knife 11 and is circumferentially provided with a plurality of rattan picking levers 141, the rattan crushing rotating shaft 15 is positioned above the rattan picking rotating shaft 14 and is circumferentially provided with a plurality of rattan crushing knives 151, and the rattan cutting knife 11, the rattan picking rotating shaft 14 and the rattan crushing rotating shaft 15 are arranged in a stepped mode.

The picker lever 141 includes a long lever 142 and a short lever 143, and the long lever 142 has a picker part 144 at a front end thereof, and the picker part 144 is bent in a rotation direction.

Example 2: referring to fig. 1-4, the high-efficiency sweet potato harvester suitable for southern plain soil comprises a rattan cutting mechanism 1, an excavating mechanism 2 and a collecting mechanism 3 which are arranged in series, wherein the rattan cutting mechanism 1 comprises a rattan cutting blade 11, a front travelling wheel 12 and a rattan cutting box 13, the front end of the rattan cutting box 13 is arranged in an open mode, the rattan cutting blade 11 is arranged at the bottom of the front end opening of the rattan cutting box 13, and the front travelling wheel 12 is positioned at the bottom of the rattan cutting box 13;

The bottom of the front end of the digging box 22 is provided with a plurality of digging knives 21, the digging knives 21 are arranged along the travelling direction of the harvester, and a gap 211 for soil to pass through is reserved between the two digging knives 21.

A relief hole 231 for the soil to pass through is reserved among the plurality of conveying rollers 23; the plurality of conveying rollers 23 are driven by one linear motor 232.

Example 3: the utility model provides a high-efficient sweet potato harvester suitable for south plain soil, refer to fig. 1-4, including the rattan mechanism 1 that cuts that sets up in series, excavating mechanism 2 and collection mechanism 3, wherein, cut rattan mechanism 1 and include cut rattan sword 11, preceding walking wheel 12 and cut rattan case 13, the open setting of front end of cut rattan case 13 is in order to hold the front and is cut the rattan, cut rattan sword 11 and install in the open bottom in cut rattan case 13 front end and outstanding cut rattan case 13 and arrange in order to cut, preceding walking wheel 12 is located cut rattan case 13 bottom and through independent motor drive, realize advancing, retreating, the curve etc. of cut rattan mechanism 1 and advance the action.

In order to realize uninterrupted cutting of vines, the vine cutter 11 comprises a fixed cutter holder 111 and a movable cutter holder 112 which are overlapped, the movable cutter holder 112 reciprocates along the length direction of the vine cutter, a plurality of blades 113 are respectively arranged on the fixed cutter holder 111 and the movable cutter holder 112 in an array mode along the length direction of the vine cutter, the angle between the blades 113 and the length direction of the cutter holder is alpha, alpha=90 degrees, the blades 113 are cut on two sides of the blades 113, and the vines positioned in front of the advancing direction can be repeatedly cut by utilizing the cooperation of the movable blades 113 and the fixed blades 113 which reciprocate.

Here, in order to realize the reciprocating motion of the movable knife rest in the length direction, one end of the movable knife rest 112 is movably inserted into the side wall of the rattan cutting box 13, so that the end can slide back and forth along the length direction, in order to avoid the movable knife rest from separating from the rattan cutting box 13, a limiting component can be arranged, the other end of the movable knife rest is provided with a U-shaped bayonet 114, a rotating shaft 132 is arranged on the rattan cutting box 13, an annular cam 133 is arranged on the periphery of the rotating shaft 132, the annular cam 133 is embedded in the U-shaped bayonet 114, the included angle between the annular cam 133 and the axis of the rotating shaft 132 is beta, beta=30°, and the continuously rotating annular cam 133 is utilized to drive the U-shaped bayonet 114 to reciprocate in the length direction of the movable knife rest 112, so that the reciprocating motion of the movable knife rest 112 integrated with the U-shaped bayonet 114 is realized; the key point is that the axis direction of the rotating shaft is parallel to the moving direction of the movable blade holder 112.

When the rattan knife 11 pulverizes rattan, in order to prevent rattan from piling up near the rattan knife 11 and affecting continuous operation thereof, a rattan picking rotating shaft 14 and a rattan crushing rotating shaft 15 are further installed in the rattan cutting box 13, the rattan picking rotating shaft 14 is located above the rattan knife 11 and circumferentially provided with a plurality of rattan crushing levers 141, the rattan crushing rotating shaft 15 is located above the rattan picking rotating shaft 14 and circumferentially provided with a plurality of rattan crushing knives 151, and the rattan cutting knives 11, the rattan picking rotating shaft 14 and the rattan crushing rotating shaft 15 are arranged in a stepwise manner, so that the rattan to be cut is picked up from the rattan cutting knives 11 by the rattan picking lever 141, and the rattan to be picked up falls onto the rattan crushing knives 151, and the rattan to be rotated is further cut and crushed by the rattan crushing knives 151, thereby facilitating collection.

The digging mechanism 2 is used as a harvesting part of sweet potatoes and comprises digging knives 21, digging boxes 22 and conveying rollers 23, wherein the digging knives 21 are arranged at the bottom of the front end of each digging box 22, the number of the digging knives is multiple according to the width of each digging box 22 and are arranged along the advancing direction, the digging of the sweet potatoes in the soil is realized by utilizing advancing kinetic energy, and the digging boxes 22 are obliquely arranged and the lowest point of each digging knife 21 is lower than the bottom end of each advancing wheel so as to contact the soil, and the design of specific digging depth is adjusted according to the operation place, the sweet potato variety and the cultivating depth. And a plurality of conveying rollers 23 are installed at the bottom of the digging box 22, are arranged perpendicular to the travelling direction, and are used for conveying the dug sweet potatoes to the direction of the collecting mechanism, wherein a linear motor 232 is arranged on the outer side wall of the digging box 22 and is used for driving the conveying rollers 23 to rotate.

Because not only sweet potatoes but also additional soil are excavated by the excavating knives 21, in order to clearly obtain a large amount of soil, on one hand, gaps 211 are reserved between the excavating knives 21 to enable the soil to permeate, on the other hand, relief holes 231 are reserved between the conveying rollers 23, the soil is further screened out by rolling in the conveying process, and here, the gaps 211 and the relief holes 231 are designed according to the actual sweet potato variety size, so that the sweet potatoes are not screened out.

In order to collect crushed vines, the collecting mechanism 3 is provided with an upper storage box 31, a conveying opening 131 is formed in the rear end of the vine cutting box 13, the conveying opening 131 is communicated with the upper storage box 31 through a conveying belt 4, one end of the conveying belt 4 extends into the conveying opening 131 and is positioned below the vine crushing knife 151, and the other end of the conveying belt extends upwards to be connected to an opening of the upper section of the upper storage box 31.

Also, in order to collect sweet potatoes, the collection mechanism 3 further comprises a lower storage box 32 below the upper storage box 31, wherein a rear traveling wheel 33 is mounted at the bottom of the lower storage box 32, and the rear traveling wheel 33 can be independently driven or driven. The rear end of the digging box 22 is supported at the opening of the lower storage box 32, and the sweet potatoes transported by the conveying rollers 23 can fall into the lower storage box 32 for storage.

In order to realize connection, the digging box 22 is arranged between the vine cutting mechanism 1 and the collecting mechanism 3 through the bracket 5, the bracket 5 has an up-down fine adjustment function by utilizing an air cylinder, and the digging knife 21 is lifted up, so that the running and transportation of the harvester on a normal road surface are prevented from being influenced.

In addition, the conveyer belt 4, the rotating shaft 132, the rattan picking rotating shaft 14 and the rattan crushing rotating shaft 15 are connected through a plurality of conveyer belts 6, and one of the conveyer belt 4, the rotating shaft 132, the rattan picking rotating shaft 14 and the rattan crushing rotating shaft 15 is connected with a driving motor 61, so that components in the rattan cutting box 13 can be synchronously driven to operate through the driving motor 61, the number of motors is reduced, the cost is reduced, and the efficiency is improved.

Claims

1. The utility model provides a high-efficient sweet potato harvester suitable for southern plain soil, its characterized in that includes rattan mechanism (1), excavation mechanism (2) and collection mechanism (3) of establishing ties, rattan mechanism (1) are including rattan sword (11), front travelling wheel (12) and rattan case (13), rattan case (13) front end is uncovered to be set up, rattan sword (11) are installed in the open bottom in rattan case (13) front end, front travelling wheel (12) are located rattan case (13) bottom;

the excavating mechanism (2) comprises an excavating knife (21), an excavating box (22) and conveying rollers (23), wherein the excavating knife (21) is arranged at the bottom of the front end opening of the excavating box (22), and a plurality of conveying rollers (23) are arranged at the bottom of the excavating box (22);

the collecting mechanism (3) comprises an upper storage box (31), a lower storage box (32) and a rear travelling wheel (33) arranged at the bottom of the lower storage box (32) in a lap joint manner;

the rear end of the rattan cutting box (13) is provided with a conveying opening (131), and the conveying opening (131) is communicated with the upper storage box (31) through a conveying belt (4);

the excavating box (22) is arranged between the vine cutting mechanism (1) and the collecting mechanism (3) through a bracket (5), the excavating box (22) is obliquely arranged, the bottom end of the excavating knife (21) is lower than the front travelling wheel (12) and the rear travelling wheel (33), and the rear end of the excavating box (22) is communicated with the lower storage box (32);

the rattan cutting knife (11) comprises a fixed knife rest (111) and a movable knife rest (112) which are overlapped, the movable knife rest (112) reciprocates along the length direction of the rattan cutting knife, the fixed knife rest (111) and the movable knife rest (112) are respectively provided with a plurality of blades (113) in an array mode along the length direction of the rattan cutting knife, the angle clamped between the blades (113) on the fixed knife rest (111) and the length direction of the fixed knife rest (111) is alpha, and the angle clamped between the blades (113) on the movable knife rest (112) and the length direction of the movable knife rest (112) is alpha, and 0 degree is less than alpha and less than 180 degrees;

one end of the movable knife rest (112) is movably inserted into the side wall of the rattan cutting box (13), the other end of the movable knife rest is provided with a U-shaped bayonet (114), a rotating shaft (132) is arranged on the rattan cutting box (13), an annular cam (133) is arranged on the periphery of the rotating shaft (132), the annular cam (133) is embedded into the U-shaped bayonet (114), and an included angle between the annular cam (133) and the axis of the rotating shaft (132) is beta, wherein beta is smaller than 90 degrees and smaller than 0 degrees;

the rattan cutting device is characterized in that a rattan picking rotating shaft (14) and a rattan crushing rotating shaft (15) are arranged in the rattan cutting box (13), the rattan picking rotating shaft (14) is located above the rattan cutting knife (11) and circumferentially provided with a plurality of rattan picking rods (141), the rattan crushing rotating shaft (15) is located above the rattan picking rotating shaft (14) and circumferentially provided with a plurality of rattan crushing knives (151), and the rattan cutting knife (11), the rattan picking rotating shaft (14) and the rattan crushing rotating shaft (15) are arranged in a step mode.

2. The efficient sweet potato harvester for southern plain soil according to claim 1, wherein the rattan lever (141) comprises a long lever (142) and a short lever (143), the front end of the long lever (142) has a picking portion (144), and the picking portion (144) is curved in a rotation direction.

3. The efficient sweet potato harvester suitable for southern plain soil according to claim 1, wherein the conveyor belt (4), the rotating shaft (132), the rattan picking rotating shaft (14) and the rattan crushing rotating shaft (15) are connected through a plurality of driving belts (6), and one of the conveyor belt (4), the rotating shaft (132), the rattan picking rotating shaft (14) and the rattan crushing rotating shaft (15) is connected with a driving motor (61).

4. The efficient sweet potato harvester suitable for the southern plain soil according to claim 1, wherein a plurality of digging knives (21) are arranged at the bottom of the front end of the digging box (22), the digging knives (21) are arranged along the advancing direction of the harvester, and a gap (211) for soil to pass through is reserved between every two digging knives (21).

5. Efficient sweet potato harvester for southern plain soil according to claim 1, wherein a relief hole (231) for soil to pass through is left between a plurality of said transfer rollers (23).

6. The efficient sweet potato harvester for southern plain soil according to claim 1, wherein the plurality of transfer rollers (23) are driven by one linear motor (232).