CN111699832B

CN111699832B - Dendrobium officinale picking machine

Info

Publication number: CN111699832B
Application number: CN202010582120.2A
Authority: CN
Inventors: 卢志宏; 杨传东; 杨文明; 张学超; 郭利彪; 史红飞
Original assignee: Tongren University
Current assignee: Tongren University
Priority date: 2020-06-23
Filing date: 2020-06-23
Publication date: 2021-06-29
Anticipated expiration: 2040-06-23
Also published as: CN111699832A

Abstract

The invention discloses a dendrobium officinale picking machine which comprises a moving seat, a storage bin, an auxiliary shearing driving assembly, a shearing device and a picking claw assembly, wherein a supporting arm is fixed below the moving seat, and the supporting arm is connected with the auxiliary shearing driving assembly and is used for driving the shearing device to move left and right so as to assist in shearing the root of dendrobium officinale; a picking claw assembly positioned on the left side of the shearing device is further arranged below the auxiliary shearing driving assembly, the picking claw assembly can pick in a shrinkage extrusion shearing mode, and after picking, the picking claw assembly extends, so that the dendrobium officinale is placed on the conveying belt, the picking efficiency is improved, and the damage to the dendrobium officinale stems and branches is reduced; the discharge end of the conveyor belt extends into the storage bin, and the storage bin is fixed at the bottom of the supporting arm.

Description

Dendrobium officinale picking machine

Technical Field

The invention belongs to the technical field of plant picking, and particularly relates to a dendrobium officinale picking machine.

Background

The dendrobium officinale is taken as a traditional Chinese medicine, can extract substances beneficial to human bodies and improve human immunity, so that the dendrobium officinale is more and more concerned, the existing dendrobium officinale picking is mainly carried out in a manual picking mode, particularly for the dendrobium officinale planted in a large scale, the efficiency is low due to the manual picking mode, and the stems and branches of the dendrobium officinale are easily damaged due to the mechanical harvesting;

the intelligent picking device for the dendrobium officinale disclosed in the Chinese patent (application number: 201920819813.1) comprises a crawler-type walking device, image acquisition equipment, a mounting frame and a cutter, wherein a collecting box 8 is mounted on the crawler-type walking device and used for collecting harvested stems, a guide groove 7 is arranged on the collecting box 8, and the end part of the guide groove 7 is positioned below the cutter 4;

the dendrobium officinale picking machine is characterized in that the machine does not stop shearing action, after the dendrobium officinale is sheared, the dendrobium officinale easily falls on a shearing part of the machine and is then taken away, at the moment, the machine cannot stop, the dendrobium officinale can damage stems and branches of the dendrobium officinale, and only the collecting bin is placed below the shearing part, so that the incomplete collecting phenomenon is easily caused.

Disclosure of Invention

In order to achieve the purpose, the invention provides the following technical scheme: a dendrobium officinale picking machine comprises a transverse walking frame, a longitudinal walking frame, a moving seat, a storage bin, an auxiliary shearing driving assembly, a shearing device and a picking claw assembly, wherein the transverse walking frame is transversely paved at the top of a planting bin, the longitudinal walking frame can transversely move along the transverse walking frame, the longitudinal walking frame extends along the longitudinal direction of the planting bin, the moving seat can longitudinally move along the longitudinal walking frame,

a supporting arm is fixed below the moving seat, and an auxiliary shearing driving assembly is connected to the supporting arm and used for driving the shearing device to move left and right so as to assist in shearing the root of the dendrobium officinale;

a picking claw assembly positioned on the left side of the shears is further arranged below the auxiliary shearing driving assembly, the picking claw assembly can pick in a shrinkage extrusion shearing mode, and after picking, the picking claw assembly extends, so that the dendrobium officinale is placed on the conveying belt;

the discharge end of the conveyor belt extends into the storage bin, and the storage bin is fixed at the bottom of the supporting arm.

Further, preferably, the picking claw assembly comprises a mounting seat, a telescopic device, supporting connecting rods, a hinged seat and a picking claw single body, wherein a plurality of supporting connecting rods are fixed on the circumferential array of the bottom of the mounting seat, and a groove-shaped hinged seat is fixed at the other end of each supporting connecting rod;

a telescopic device is fixed above the mounting seat, the telescopic end of the telescopic device is connected with a telescopic rod, and a telescopic column bin and a connecting ball are sequentially fixed at the other end of the telescopic rod;

it is a plurality of it is equallyd divide and to correspond respectively and articulate on connecting the ball to pick the free upper end tip of claw, and is a plurality of it is equallyd divide and to correspond respectively and articulate on articulated seat to pick the free upper end middle part of claw to make and to drive a plurality ofly through connecting the upper and lower displacement of ball pick the claw monomer and carry out shrink and extension motion.

Further, as preferred, the expansion bend includes outlet duct, air inlet plug, telescoping cylinder and reducing post, wherein, the reducing post slides and sets up in the telescoping cylinder, be fixed with the piston on the reducing post, be connected with a plurality of reset spring between the top of piston and telescoping cylinder, the both sides of telescoping cylinder and the below that is located the piston are provided with outlet duct and air inlet plug respectively, the outlet duct is normally open state, and, just, is greater than the air output of outlet duct through the air inlet plug to the air input of aerifing in the telescoping cylinder to make the piston rebound, when stopping admitting air, the piston moves down under reset spring's effect.

Further, as preferred, the air inlet plug is continuous with the end of giving vent to anger of aspirator pump, the end of breathing in of aspirator pump has connected gradually flexible bellows and air extraction rod, the air extraction rod is fixed to stretch into in the flexible post storehouse, flexible post storehouse is linked together with the connecting ball, the connecting ball adopts the hose to be linked together with picking the claw monomer to make the dendrobii officmalis can be adsorbed on picking the claw monomer.

Further, preferably, the picking claw single body is of a cavity structure, the middle part of the inner side of the picking claw single body is fixedly communicated with a limiting rib, and a plurality of adsorption holes are distributed on the inner side of the limiting rib;

the bottom of the picking claw single body is fixedly communicated with an arc-shaped capturing soft body;

picking tool heads are further fixed at the bottom ends of the picking claw bodies.

Preferably, a plurality of adsorption holes are distributed on the inner side of the catching soft body, and the catching soft body has certain variable capacity and supporting force.

Further, preferably, the number of the picking claw monomers is 6-10.

Further, as the preferred, a rotating seat is fixed on one of the supporting connecting rods, the rotating seat is rotatably arranged on the picking arm, and the rotating seat is driven by a forward and reverse rotating motor fixed on the picking arm, so that the dendrobium officinale can be placed on the conveying belt through rotation.

Further, preferably, the auxiliary shearing driving assembly comprises a connecting plate, a lead screw, a sliding rod, a limiting rod and a fixed seat, wherein the connecting plate is fixed on the supporting arm, a transmission bin is fixed at the other end of the connecting plate and can drive the lead screw to rotate, a nut seat is connected to the lead screw in a transmission manner and is fixedly embedded in the sliding rod, the sliding rod penetrates through the fixed seat in a sliding manner, and the fixed seat is connected to the movable seat through an L-shaped auxiliary connecting rod;

a limiting rod which is arranged in the same direction as the lead screw is fixedly connected between the fixing seat and the connecting plate, a limiting seat is arranged on the limiting rod in a sliding manner, and the limiting seat is fixedly connected with the sliding rod;

the end part of the sliding rod is fixedly provided with a first joint, the lower part of the first joint is connected with a cutter through a second joint, and the cutter is an electric cutter.

Preferably, one end of the screw rod is rotatably arranged in the transmission bin, a driven bevel gear is coaxially fixed at the end of the screw rod and meshed with the driving bevel gear, and the driving bevel gear is driven to rotate by a stepping motor fixed outside the transmission bin.

Compared with the prior art, the invention has the beneficial effects that:

1. in this device, be connected with supplementary cutting drive assembly on the support arm, be used for the drive to cut the ware and control, thereby supplementary cutting dendrobium officinale's root, it is not thorough to prevent to pick claw subassembly cutting, thereby realize once picking and can pick completely, the picking claw subassembly that sets up in addition can pick with the mode that the shrink extrusion was cut, and pick the back, it extends to pick claw subassembly, thereby place dendrobium officinale on the conveyer belt, the staff is picked in the imitation, picking efficiency is improved, damage to dendrobium officinale stem branch has been reduced.

2. In this device, adopt the aspirator pump to provide power for the expansion bend, and the end of breathing in of aspirator pump is linked together with picking claw monomer, thereby make the dendrobii officmalis caulis adsorbed by picking claw monomer, reduce its possibility that drops, in addition, the seizure software on picking the claw monomer can be when picking claw monomer closure, reduce two adjacent clearances of picking between the claw monomer, prevent that dendrobii officmalis caulis from scattering in the clearance, and, can take place deformation when the seizure software cross-over that is flexible material overlaps, prevent to pick the unable closure of claw monomer, can also reduce the damage to dendrobii officmalis caulis.

Drawings

Fig. 1 is a schematic plan structure diagram of a dendrobium officinale picking machine;

fig. 2 is a schematic structural diagram of a picking claw assembly in a dendrobium officinale picking machine;

FIG. 3 is a partially enlarged schematic view of FIG. 2;

in the figure: 1. a transverse walking frame; 2. a longitudinal walking frame; 3. a movable seat; 4. a support arm; 5. a storage bin; 6. a conveyor belt; 7. a connecting plate; 8. a transmission bin; 9. a drive bevel gear; 10. a screw rod; 11. a nut seat; 12. a slide bar; 13. a limiting seat; 14. a limiting rod; 15. an auxiliary link; 16. a fixed seat; 17. a first joint; 18. a second joint; 19. a scissor cutter; 20. picking the arm; 21. a rotating seat; 22. a picking claw assembly; 23. a mounting seat; 24. a getter pump; 25. a retractor; 26. a telescopic rod; 27. a telescopic column bin; 28. a connecting ball; 29. a support link; 30. a hinged seat; 31. picking the claw single bodies; 32. limiting ribs; 33. picking a tool bit; 34. capturing software; 35. a suction rod; 36. a flexible bellows; 37. an air outlet pipe; 38. an air inlet plug; 39. a telescopic cylinder; 40. a variable diameter column; 41. a piston.

Detailed Description

Referring to fig. 1 to 3, in the embodiment of the invention, a dendrobium officinale picking machine comprises a transverse walking frame 1, a longitudinal walking frame 2, a moving seat 3, a storage bin 5, an auxiliary cutting driving assembly, a cutter 19 and a picking claw assembly 22, wherein the transverse walking frame 1 is transversely laid on the top of a planting bin, the longitudinal walking frame 2 can transversely move along the transverse walking frame 1, the longitudinal walking frame 2 extends along the longitudinal direction of the planting bin, the moving seat 3 can longitudinally move along the longitudinal walking frame 2, specifically, during picking, the longitudinal walking frame moves along the transverse walking frame 1, after picking of dendrobium officinale in one transverse direction is finished, only the moving seat 3 needs to move along the longitudinal walking frame 2 for one lattice, and then the longitudinal walking frame continues to move along the transverse walking frame 1 to realize picking in the other transverse direction, the following can thus be set: the transverse walking frame 1 is at least one I-shaped steel, the longitudinal walking frame 2 is clamped on the transverse walking frame 1 through a plurality of groups of idler wheels, the longitudinal walking frame 2 can be driven to move through rotation of the idler wheels, the rolling can be driven by a motor, the moving seat 3 is arranged at the bottom of the longitudinal walking frame 2 in a sliding mode, longitudinal displacement of the moving seat 3 is achieved through manual push-pull, and resources are saved to the maximum extent.

A supporting arm 4 is fixed below the moving seat 3, and an auxiliary shearing driving assembly is connected to the supporting arm 4 and used for driving the shearing device 19 to move left and right so as to assist in shearing the root of the dendrobium officinale;

a picking claw component 22 positioned on the left side of the scissor 19 is further arranged below the auxiliary shearing driving component, the picking claw component is mainly adopted to pick the dendrobium officinale in the device, the scissor 19 is used for assisting picking, the picking claw component 22 can pick the dendrobium officinale in a shrinkage extrusion shearing mode, and after picking, the picking claw component extends so as to place the dendrobium officinale on the conveyor belt 6;

the discharge end of the conveyor belt 6 extends into the storage bin 5, and the conveyor belt 6 is supported on the storage bin 5, which is not described herein again, and the storage bin 5 is fixed at the bottom of the support arm 4.

In this embodiment, as shown in fig. 2, the picking claw assembly 22 includes a mounting seat 23, a telescopic device 25, a plurality of support links 29 fixed to a circumferential array at the bottom of the mounting seat 23, a hinge seat 30 and a picking claw single body 31, wherein a groove-shaped hinge seat 30 is fixed to the other end of each support link 29;

an expansion piece 25 is fixed above the mounting seat 23, the expansion end of the expansion piece 25 is connected with an expansion rod 26, and the other end of the expansion rod 26 is sequentially fixed with an expansion column bin 27 and a connecting ball 28;

it is a plurality of the upper end tip of picking claw monomer 31 is equallyd divide and is corresponded respectively and articulate on connecting ball 28, and is a plurality of the upper end middle part of picking claw monomer 31 is equallyd divide and is corresponded respectively and articulate on articulated seat 30 to it can drive a plurality ofly to make through the upper and lower displacement of connecting ball 28 picking claw monomer 31 carries out shrink and extension motion.

As a preferred embodiment, as shown in fig. 3, the telescopic device 25 includes an air outlet pipe 37, an air inlet plug 38, a telescopic cylinder 39 and a variable diameter cylinder 40, wherein the variable diameter cylinder 40 is slidably disposed in the telescopic cylinder 39, a piston 41 is fixed on the variable diameter cylinder 40, a plurality of return springs are connected between the piston 41 and the top of the telescopic cylinder 39, the air outlet pipe 37 and the air inlet plug 38 are respectively disposed on two sides of the telescopic cylinder 39 and below the piston 41, the air outlet pipe 37 is in a normally open state, and an air intake amount of the air inlet plug 38 to the telescopic cylinder 39 is greater than an air outlet amount of the air outlet pipe 37, so that the piston 41 moves upward, thereby driving the picking claw monomers 31 to contract, so as to achieve picking, and when air inlet is stopped, the piston 41 moves downward under the action of the return springs.

In this embodiment, the air inlet plug 38 is connected with the air outlet end of the air suction pump 24, the air suction end of the air suction pump 24 is sequentially connected with the flexible corrugated pipe 36 and the air suction rod 35, the air suction rod 35 is fixedly extended into the telescopic column bin 27, the telescopic column bin 27 is communicated with the connecting ball 28, the connecting ball 28 is communicated with the picking claw single body 31 through a hose, so that the dendrobium officinale can be adsorbed on the picking claw single body 31, and the possibility of falling of the dendrobium officinale is reduced.

In this embodiment, the picking claw unit 31 is a cavity structure, the middle part of the inner side of the picking claw unit is fixedly communicated with a limiting rib 32, and a plurality of adsorption holes are distributed on the inner side of the limiting rib 32;

the bottom of the picking claw single body 31 is fixedly communicated with an arc-shaped capturing soft body 34;

the bottom end of the picking claw single body 31 is also fixed with a picking tool bit 33.

As a preferred embodiment, a plurality of adsorption holes are distributed on the inner side of the capturing soft body 34, the capturing soft body 34 has certain variable capability and supporting force, when a plurality of picking claw single bodies are closed, the capturing soft body 34 can reduce the gap between two adjacent picking claw single bodies 31 to prevent the dendrobium officinale from scattering from the gap, and the capturing soft body made of flexible material can deform when being overlapped in a crossing manner to prevent the picking claw single bodies from being closed, and reduce the damage to the dendrobium officinale.

As a preferred embodiment, the number of the picking claw single bodies is 8.

In this embodiment, a rotating base 21 is fixed on one of the support connecting rods 29, the rotating base 21 is rotatably disposed on the picking arm 20, and the rotation of the rotating base 21 is driven by a forward and reverse rotating motor fixed on the picking arm 20, so that the dendrobium officinale can be placed on the conveyor belt 6 by rotation.

In this embodiment, as shown in fig. 1, the auxiliary shearing driving assembly includes a connecting plate 7, a screw rod 10, a sliding rod 12, a limiting rod 14, and a fixing seat 16, wherein the connecting plate 7 is fixed on the supporting arm 4, and a transmission bin 8 is fixed at the other end of the connecting plate 7, the transmission bin 8 can drive the screw rod 10 to rotate, the screw rod 10 is in transmission connection with a screw seat 11, the screw seat 11 is fixedly embedded in the sliding rod 12, the sliding rod 12 slides through the fixing seat 16, and the fixing seat 16 is connected to the moving seat 3 by using an L-shaped auxiliary connecting rod 15;

a limiting rod 14 which is arranged in the same direction as the lead screw 10 is fixedly connected between the fixed seat 16 and the connecting plate 7, a limiting seat 13 is arranged on the limiting rod 14 in a sliding manner, and the limiting seat 13 is fixedly connected with the sliding rod 12;

a first joint 17 is fixed at the end of the sliding rod 12, a shear 19 is connected below the first joint 17 through a second joint 18, and the shear 19 is an electric shear.

In this embodiment, one end of the screw rod 10 is rotatably disposed in the transmission bin 8, a driven bevel gear is coaxially fixed to an end of the screw rod 10, the driven bevel gear is engaged with the driving bevel gear 9, and the driving bevel gear 9 is driven to rotate by a stepping motor fixed outside the transmission bin 8.

The working principle of the device is as follows: when the dendrobium officinale is picked, the longitudinal walking frame moves along the transverse walking frame 1, after the picking of the dendrobium officinale in one transverse direction is finished, the moving seat 3 only needs to move one grid along the longitudinal walking frame 2, and then the longitudinal walking frame continues to move along the transverse walking frame 1, so that the picking in the other transverse direction is realized;

the specific picking process is as follows: picking claw assembly 22 moves to the position of dendrobium officinale, a cluster of dendrobium officinale enters into the surrounding ring of the picking claw assembly through the gap between adjacent picking claw monomers, at the moment, air suction pump 24 starts to work, the air inlet amount of air charged into telescopic cylinder 39 through air inlet plug 38 is larger than the air outlet amount of air outlet pipe 37, so that piston 41 moves upwards, a plurality of picking claw monomers 31 are driven to contract, picking is realized, the air suction end of air suction pump 24 is communicated with picking claw monomers 31, so that the dendrobium officinale can be adsorbed, the possibility of falling of the dendrobium officinale is reduced, after picking, picking claw assembly 22 is rotated to move above conveyor belt 6, at the moment, the air suction pump stops working, piston 41 moves downwards under the action of reset spring, picking claw assembly extends, so that the dendrobium officinale is placed on conveyor belt 6, the discharge end of conveyor belt 6 extends into storage bin 5, the collection of the dendrobium officinale is realized.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention are equivalent to or changed within the technical scope of the present invention.

Claims

1. The utility model provides a dendrobium officinale picking machine, its includes horizontal walking frame (1), vertical walking frame (2), removes seat (3), storage compartment (5), supplementary cutting drive assembly, cuts ware (19) and picks claw subassembly (22), wherein, horizontal walking frame (1) is transversely laid at the top of planting the storehouse, vertical walking frame (2) can carry out lateral shifting along horizontal walking frame (1), vertical walking frame (2) are along the longitudinal extension of planting the storehouse, it can carry out longitudinal shifting along vertical walking frame (2) to remove seat (3), its characterized in that:

a supporting arm (4) is fixed below the moving seat (3), and an auxiliary shearing driving assembly is connected to the supporting arm (4) and used for driving the shearing device (19) to move left and right so as to assist in shearing the root of the dendrobium officinale;

a picking claw assembly (22) positioned on the left side of the shears (19) is further arranged below the auxiliary shearing driving assembly, the picking claw assembly (22) can pick in a shrinkage extrusion shearing mode, and after picking, the picking claw assembly extends, so that the dendrobium officinale is placed on the conveyor belt (6);

the discharge end of the conveyor belt (6) extends into the storage bin (5), and the storage bin (5) is fixed at the bottom of the supporting arm (4);

the picking claw assembly (22) comprises a mounting seat (23), a telescopic device (25), supporting connecting rods (29), a hinged seat (30) and picking claw single bodies (31), wherein the bottom of the mounting seat (23) is fixed with a plurality of supporting connecting rods (29) in a circumferential array, and the other end of each supporting connecting rod (29) is fixed with a groove-shaped hinged seat (30);

a telescopic device (25) is fixed above the mounting seat (23), the telescopic end of the telescopic device (25) is connected with a telescopic rod (26), and a telescopic column bin (27) and a connecting ball (28) are sequentially fixed at the other end of the telescopic rod (26);

the upper end parts of the picking claw single bodies (31) are respectively and correspondingly hinged on the connecting ball (28), and the middle parts of the upper ends of the picking claw single bodies (31) are respectively and correspondingly hinged on the hinge seats (30), so that the picking claw single bodies (31) can be driven to contract and extend through the up-and-down displacement of the connecting ball (28);

the expansion bend (25) comprises an air outlet pipe (37), an air inlet plug (38), an expansion cylinder (39) and a variable diameter column (40), wherein the variable diameter column (40) is arranged in the expansion cylinder (39) in a sliding mode, a piston (41) is fixed on the variable diameter column (40), a plurality of reset springs are connected between the tops of the piston (41) and the expansion cylinder (39), the air outlet pipe (37) and the air inlet plug (38) are arranged on the two sides of the expansion cylinder (39) and below the piston (41) respectively, the air outlet pipe (37) is in a normally open state, and the air inlet amount of the air filled into the expansion cylinder (39) through the air inlet plug (38) is larger than the air outlet amount of the air outlet pipe (37), so that the piston (41) moves upwards, and when air inlet is stopped, the piston (41) moves downwards under the action of the reset springs.

2. The dendrobium officinale picking machine according to claim 1, characterized in that: the air inlet plug (38) is connected with the air outlet end of the air suction pump (24), the air suction end of the air suction pump (24) is sequentially connected with a flexible corrugated pipe (36) and an air suction rod (35), the air suction rod (35) is fixedly stretched into a telescopic column bin (27), the telescopic column bin (27) is communicated with a connecting ball (28), the connecting ball (28) is communicated with a picking claw monomer (31) through a hose, and therefore the dendrobium officinale can be adsorbed on the picking claw monomer (31).

3. The dendrobium officinale picking machine according to claim 2, characterized in that: the picking claw single body (31) is of a cavity structure, the middle part of the inner side of the picking claw single body is fixedly communicated with a limiting rib (32), and a plurality of adsorption holes are distributed on the inner side of the limiting rib (32);

the bottom of the picking claw single body (31) is fixedly communicated with an arc-shaped capturing soft body (34);

the bottom end of the picking claw single body (31) is also fixed with a picking tool bit (33).

4. The dendrobium officinale picking machine according to claim 3, characterized in that: a plurality of adsorption holes are distributed on the inner side of the catching soft body (34), and the catching soft body (34) has certain variable capacity and supporting force.

5. The dendrobium officinale picking machine according to claim 3, characterized in that: the number of the picking claw monomers is 6-10.

6. The dendrobium officinale picking machine according to claim 1, characterized in that: one of the support connecting rods (29) is fixed with a rotating seat (21), the rotating seat (21) is rotatably arranged on the picking arm (20), and the rotating seat (21) is driven by a forward and reverse rotating motor fixed on the picking arm (20), so that the dendrobium officinale can be placed on the conveyor belt (6) through rotation.

7. The dendrobium officinale picking machine according to claim 1, characterized in that: the auxiliary shearing driving assembly comprises a connecting plate (7), a lead screw (10), a sliding rod (12), a limiting rod (14) and a fixing seat (16), wherein the connecting plate (7) is fixed on the supporting arm (4), the other end of the connecting plate (7) is fixedly provided with a transmission bin (8), the transmission bin (8) can drive the lead screw (10) to rotate, a screw seat (11) is in transmission connection with the lead screw (10), the screw seat (11) is fixedly embedded in the sliding rod (12), the sliding rod (12) penetrates through the fixing seat (16) in a sliding mode, and the fixing seat (16) is connected to the moving seat (3) through an L-shaped auxiliary connecting rod (15);

a limiting rod (14) which is arranged in the same direction as the screw rod (10) is fixedly connected between the fixing seat (16) and the connecting plate (7), a limiting seat (13) is arranged on the limiting rod (14) in a sliding manner, and the limiting seat (13) is fixedly connected with the sliding rod (12);

the end part of the sliding rod (12) is fixed with a first joint (17), the lower part of the first joint (17) is connected with a shear (19) through a second joint (18), and the shear (19) is an electric shear.

8. The dendrobium officinale picking machine according to claim 7, characterized in that: one end of the screw rod (10) is rotatably arranged in the transmission bin (8), a driven bevel gear is coaxially fixed at the end part of the screw rod (10), the driven bevel gear is meshed with the driving bevel gear (9), and the driving bevel gear (9) is driven to rotate by a stepping motor fixed outside the transmission bin (8).