CN206895765U - Magnetic separation grain bulking machine - Google Patents

Abstract

The utility model discloses a kind of magnetic separation grain bulking machine, including support, support is connected with press chamber, and the feed end of press chamber is communicated with feed pipe upwards；Motor, motor connection small belt pulley are provided with front side of support, small belt pulley is connected with big belt pulley by driving belt；Pressing screw assembly is provided with the inner chamber of press chamber；Press chamber rear end is connected with discharging opening, and discharging opening is connected with discharging boot, and discharging boot is provided with hydraulic cylinder, and pressing screw is coaxially set with the main shaft and the two is linked together by connecting screw；Big belt pulley and the main shaft key connection；The utility model favorable sealing property, material stirring are uniform, stable and reliable in work, are capable of the thickness degree of control material, and keep lubricating oil cooling good.

Description

Magnetic separation grain bulking machine

Technical field

It the utility model is related to a kind of grain processing apparatus, more particularly to a kind of magnetic separation grain that expanding treatment is carried out to grain Eat bulking machine.

Background technology

The technology of expansion grain obtains increasingly extensive application in recent years, is applied not only to the dilated food that people eat, and It is widely used in feed processing technology field.

Puffing technique is that grain is placed in puffing apparatus, and grain is heated, pressurizeed, and makes the moisture in grain grain in overheat shape State, grain grain become soft in itself；When reaching certain high pressure, grain by being sent out in expanded container, high pressure quickly becomes normal pressure, this When grain intragranular in the moisture instant vaporization of superheat state so as to occur violent explosion, hydrone is inflatable about 2000 times.Huge The bulbs of pressure have not only broken up the formalness of grain grain, and broken grain intragranular molecular structure, by insoluble long-chain Starch prescinds into water-soluble short-chain starch, dextrin and sugar, and then the insoluble substance in dilated food reduces, water-soluble substances Increase.

Puffing technique serves the effect of amylase, i.e., before food has not been entered into oral cavity, is just split starch Solution preocess, in this sense, bulking equipment are equal to the digestive organs for extending people.This has speeded up human body to food Digestion process, improve the digestibility of dilated food.From this angle, puffing technique is that a kind of preferably grain adds Work technology, it is not only beneficial to people, and when being used for field of feed, can also improve the utilization rate of feed.

Existing grain bulking machine is complicated, and machine head heating seriously causes job insecurity, and lubricating oil is easy in use Leakage is, it is necessary to often overhaul（Sealing condition is such as checked, lubricating oil is added, changes sealing ring etc.）, can not be in separation of material Iron class impurity, use is more inconvenient.

Utility model content

The purpose of this utility model is to provide the magnetic separation grain that a kind of material stirring is uniform, stable and reliable in work expanded Machine, thickness degree, the iron class impurity in separation of material and convenient remove for being capable of control material separate next iron class impurity.

To achieve the above object, magnetic separation grain bulking machine of the present utility model includes support, and support is set by some intervals The support frame put is connected with columnar press chamber, and press chamber one end is feed end and the other end is discharge end；The feed end of press chamber to On be communicated with feed pipe, the top of feed pipe is provided with charging aperture；Using press chamber feed end side as its front side and with press chamber discharge end Side is rear side, and motor is provided with front side of support, and the output shaft of motor is provided with small belt pulley,

Small belt pulley is connected with big belt pulley by driving belt；Pressing screw assembly, pressing screw assembly are provided with the inner chamber of press chamber Including pressing screw in a tubular form, screw rod is equipped with pressing screw, pressing screw outer wall is provided with spiral pushing blade；The spiral pushing blade Pitch be gradually reduced from the front to the back；

Separation seal is fixedly connected with multiple stirring gear sticks for being used to stir material, each stirring gear from the front to the back at the top of press chamber Press chamber is stretched out in the outer end of rod and press chamber is stretched into the inner；With the axially middle part of press chamber for boundary, some stirring gears anterior positioned at press chamber Steam inlet tube is provided with rod, the outer end of steam inlet tube stretches out stirring gear stick and the steam pipework for connecting outside, stirs gear stick The inner is communicated with steam inlet tube and the steam vent of press chamber inner chamber；Thermometer is provided with least one stirring gear stick of press chamber back segment； Press chamber back segment is connected with pressure gauge, and pressure gauge stretches out press chamber upwards；

Press chamber rear end is fixedly connected with discharging opening, and discharging opening is connected with discharging in rear big preceding small toroidal, discharging opening Boot；The pressing screw is coaxially set with the main shaft and the two is linked together by connecting screw, and connecting screw is positioned at master It is threadedly coupled at axle and the axis of pressing screw and with pressing screw；

The outer rim key connection of the centre bore of big belt pulley and the main shaft；Support front end is provided with support, and main shaft passes through bearing It is connected to bearing block on support；

The feed pipe is V-shaped broken pipe, and the tube wall lateral surface of every section of V-shaped feed pipe is equipped with magnetic separation electromagnetism Iron；Feed pipe at magnetic separation electromagnet is provided with residue-removing opening and the clear material baffle plate for closing the residue-removing opening, expects baffle plate clearly By it is be hinged be spirally connected or clamping in a manner of be detachably connected on feed pipe.

The press chamber includes some press chamber sections, is linked together between adjacent press chamber section by flange arrangement；The pressing screw Including some pressing screw sections in a tubular form, snapped connection together between adjacent pressing screw section；The screw rod of wearing runs through all pressing screw sections And it is threadedly coupled with all pressing screw sections.

Pressing screw front end is connected by buckle structure with main shaft, and buckle structure includes the spiral buckle for being arranged on pressing screw front end With the spiral buckle for being arranged on rear-end of spindle, the spiral buckle of rear-end of spindle is mutually adapted with the spiral buckle of pressing screw front end.

The utility model has the following advantages：

1. feed pipe is in the shape of the letter V, material turn back by when speed reduce；Plus the tube wall of every section of V-shaped feed pipe Lateral surface is equipped with magnetic separation electromagnet, is advantageous to magneticly elect more iron class impurity to come.The setting of clear material baffle plate, is easy to clear Except magneticly elect come and adsorb charging tube wall on iron class impurity.Using electromagnet, then clean and inhale after the power-off of convenient electromagnetic iron The tiny iron class impurity being attached on charging tube wall.

2. the pitch of spiral pushing blade is gradually reduced from the front to the back, material is compressed during spiral pushing material in rotation Amount gradually increase, pressure gradually rises, and is advantageous to being smoothed out for puffing process.

3. the setting of thermometer and pressure gauge, it is easy to the temperature and pressure before material is expanded in monitoring work, so as to more smart Quasi- ground adjustment work process, improves expansion effect.

4. connecting screw is located at main shaft and the axis of pressing screw and is threadedly coupled with pressing screw, such connected mode is very just Link together, remove also very convenient in by pressing screw and main shaft.

5. pressing screw front end is connected by buckle structure with main shaft, adapt to transmit the needs of high torque, and very just In connection.Bearing is thrust bearing or pressure bearing, can adapt to axial force larger during work.

Brief description of the drawings

Fig. 1 is structural representation of the present utility model；

Fig. 2 is schematic cross-sectional view of the present utility model；

Fig. 3 is the enlarged drawing at A in Fig. 2；

Fig. 4 is the enlarged drawing at B in Fig. 2；

Fig. 5 is the enlarged drawing at C in Fig. 2；

Fig. 6 is dimensional structure diagram of the present utility model；

Fig. 7 is bearing chamber and the half-section diagram at belt pulley；

Fig. 8 is the half-section diagram of pressing screw assembly；

Fig. 9 is the dimensional structure diagram of pressing screw assembly；

Figure 10 is the structural representation that pressing screw is connected with main shaft using spiral buckle；

Figure 11 is the structural representation that pressing screw is connected with main shaft using eye-splice；

Figure 12 is the schematic diagram for the main shaft that preceding helixseal and rear screw sealing are provided with bearing chamber；

Figure 13 is the structural representation of the heat transfer floor of Y types；

Figure 14 is Figure 13 top view.

Embodiment

Direction shown in arrow in Fig. 7 is pipeline at this（Overflow oil pipe and oil return pipe）The flow direction of middle lubricating oil.

As shown in Fig. 1 to Figure 14, magnetic separation grain bulking machine of the present utility model includes support 1, and support 1 passes through some intervals The support frame 2 of setting is connected with columnar press chamber 3, and the one end of press chamber 3 is feed end and the other end is discharge end；Press chamber 3 is entered Material end is communicated with feed pipe 4 upwards, and the top of feed pipe 4 is provided with charging aperture 5；Using the feed end side of press chamber 3 as its front side（Fig. 1 It is front side of the present utility model with the side of big belt pulley in Fig. 26）And using the discharge end side of press chamber 3 as rear side（In Fig. 1 and Fig. 2 Discharging boot 8 side is rear side of the present utility model）, the front side of support 1 is provided with motor 9, and the output shaft of motor 9 is provided with belt lace Wheel 7.

Small belt pulley 7 is connected with big belt pulley 6 by driving belt；Pressing screw assembly is provided with the inner chamber of press chamber 3, pressing screw is total Into including pressing screw 10 in a tubular form, screw rod 11 is equipped with pressing screw 10, the outer wall of pressing screw 10 is provided with spiral pushing blade 12；It is described The pitch of spiral pushing blade 12 is gradually reduced from the front to the back.As shown in Figure 8 and Figure 9, spiral pushing blade 12 is discontinuous knot Structure.

Separation seal is fixedly connected with multiple stirring gear sticks 13 for being used to stir material to the top of press chamber 3 from the front to the back, respectively stirs The outer end stretching press chamber 3 and the inner for mixing gear stick 13 stretch into press chamber 3；It is some before press chamber 3 with the axially middle part of press chamber 3 for boundary Steam inlet tube 14 is provided with the stirring gear stick 13 in portion, stirring gear stick 13 is stretched out and for connecting outside in the outer end of steam inlet tube 14 Steam pipework, stirring gear stick 13 the inner are communicated with steam inlet tube 14 and the steam vent 15 of the inner chamber of press chamber 3；The back segment of press chamber 3 is at least Thermometer 16 is provided with one stirring gear stick 13；The back segment of press chamber 3 is connected with pressure gauge 17, and pressure gauge 17 stretches out press chamber 3 upwards.

The rear end of press chamber 3 has been bolted to connection discharging opening 18, and discharging opening 18 is in rear big preceding small toroidal, discharging Mouth 18 is connected with discharging boot 8, and the boot 8 that discharges is provided with hydraulic cylinder 19, and the front end of hydraulic cylinder piston rod is provided with big preceding small afterwards Taper type expansion control first 20；The front end external diameter of expansion control first 20 is less than the front inner diameter of discharging opening 18, expansion control First 20 rear end external diameter is more than the front inner diameter of discharging opening 18 and less than the back end inside diameter of discharging opening 18；Expansion control first 20 is stretched into Discharging opening 18 and the tapping channel 21 that annular is formed between the inwall of discharging opening 18.

The front end of pressing screw 10 is connected with main shaft 22, and the pressing screw 10 is coaxially set with the main shaft 22 and the two passes through Connecting screw 23 links together, and connecting screw 23 is located at main shaft 22 and the axis of pressing screw 10 and is threadedly coupled with pressing screw 10； The relation that connecting screw is not threadedly coupled through main shaft and main shaft.The head of connecting screw 23 is crimped on main shaft 22 Front end face on.

The outer rim key connection of the centre bore of big belt pulley 6 and the main shaft 22；The front end of support 1 is provided with cooling heat transferring case 24, The top of cooling heat transferring case 24 is provided with support 25, and main shaft 22 is connected on support 25 by bearing 30 and bearing block 31.

Profit dividing plate 26 is up to provided tiltedly with down afterwards by preceding in cooling heat transferring case 24, and profit dividing plate 26 is by cooling heat transferring case 24 It is divided into oil pocket 34 and water cavity 35；The two sides of the profit dividing plate 26 are uniformly connected with the heat transfer rib that some sections are in Y types respectively Plate, heat transfer floor include some heat transfer connecting plates 27 being connected on profit dividing plate 26, and the free end of heat transfer connecting plate 27, which is connected with, is in The heat sink 28 of V-arrangement；Heat transfer connecting plate 27 is provided with through hole 29；

The front-end and back-end of bearing block 31 are respectively equipped with bearing (ball) cover 32, former and later two bearing (ball) covers 32, bearing block 31 with And main shaft 22 surrounds the bearing chamber for installing the bearing 30, and lubricating oil is marked with bearing chamber；Between bearing chamber and the oil pocket 34 It is connected with and overflows oil pipe 33, overflows the upper end of oil pipe 33 and stretch into bearing chamber and higher than the bottom surface of bearing chamber, the lower end of spilling oil pipe 33 Stretch into the top of oil pocket 34；The lower ending opening of spilling oil pipe 33 is located at the top of a heat transfer connecting plate 27 of top.

The bearing chamber is connected with oil return pipe 36, and oil return pipe 36 is connected with scavenge oil pump 37, the oil inlet pipe 38 of scavenge oil pump 37 to Under stretch into the bottom of the oil pocket 34 and be connected with oil filter 39（It is preferred that using ferrule oil filter 39, filter efficiency is high, structure Simply, maintenance is easy）；The bottom of water cavity 35 is provided with the water inlet 40 for being used for connecting external water inlet pipe, the water cavity 35 Top is provided with the delivery port 41 for being used for connecting external outlet pipe.

Helixseal 42 and rear screw sealing 43, forward and backward spiral shell before being respectively equipped with the main shaft 22 in bearing chamber rear and front end portion Revolve the oppositely oriented of sealing 42,43 and push lubricating oil to direction in the middle part of bearing chamber when main shaft 22 rotates；

The feed pipe 4 is V-shaped broken pipe, and the tube wall lateral surface of every section of V-shaped feed pipe 4 is equipped with magnetic separation electromagnetism Iron 44.

The press chamber 3 includes some press chamber sections, is linked together between adjacent press chamber section by flange arrangement 45, so that It is easy to during installation according to the entire length for being actually needed adjustment press chamber 3.

Feed pipe 4 at magnetic separation electromagnet 44 is provided with residue-removing opening and the clear material baffle plate for closing the residue-removing opening 46, it is clear expect baffle plate 46 by it is be hinged be spirally connected or clamping in a manner of be detachably connected on feed pipe 4.In Fig. 1, Fig. 2 and Fig. 6, clearly Material mouth is blocked by material baffle plate 46 clearly.Clear material baffle plate 46 will be opened during clear material, by residue-removing opening cleaning absorption in feed pipe pipe Iron class impurity on wall.

During charging, magnetic separation electromagnet 44 is powered, and the iron class impurity in material is attracted on the feed pipe 4 of electromagnet 44. Periodically during cleaning and maintenance, clear material baffle plate 46 is opened, iron class impurity is taken out.Absorption is tiny miscellaneous on the tube wall of feed pipe 4 Matter is not easy to be removed, and at this moment can close electromagnet 44, tiny iron class impurity is no longer adsorbed on tube wall, so as to conveniently take Go out.Why do not powered off at the very start for electromagnet 44, be that impurity of the absorption on feed pipe 4 falls on bottom after avoiding power-off With pressing screw assembly junction, so as to cause to be difficult to take out.

Overflow the upper end of oil pipe 33 and stretch into bearing chamber and higher than the bottom surface of bearing chamber, so, the oil level only in bearing chamber During higher than overflowing oil pipe 33, lubricating oil can be just overflowed in the oil pocket 34 of cooling heat transferring case 24 by overflowing oil pipe 33, ensure axle The lubricating oil for holding interior has certain liquid level, lubricates good shape so as to ensure that main shaft 22 and bearing 30 are constantly in State, insufficient lubrication is prevented, phenomena such as producing friction, overheat.

Magnetic separation electromagnet 44（Or permanent magnet）, oil filter 39, flange arrangement 45, spiral buckle and eye-splice etc. be routine Technology, concrete structure are no longer described in detail.

The pressing screw 10 includes some pressing screw sections in a tubular form, is snapped connection together between adjacent pressing screw section；It is described to wear Screw rod 11 is through all pressing screw section threaded connections of all pressing screw Duan Bingyu.

The front end of pressing screw 10 is connected by buckle structure with main shaft 22 to transmit bigger moment of torsion, and buckle structure can be optional Any of following two structures：1. as shown in Figure 10, buckle structure include be arranged on the front end of pressing screw 10 spiral buckle and The spiral buckle of the rear end of main shaft 22 is arranged on, the spiral buckle of the rear end of main shaft 22 is mutually suitable with the spiral buckle of the front end of pressing screw 10 Match somebody with somebody.

2. as shown in figure 11, the front end of pressing screw 10 is connected by buckle structure with main shaft 22 to transmit bigger moment of torsion, card Buckle structure includes the eye-splice for being arranged on the front end of pressing screw 10 and the eye-splice for being arranged on the rear end of main shaft 22, the eye-splice and squeezing of the rear end of main shaft 22 The eye-splice of the front end of spiral shell 10 is mutually adapted.

Pulley cover 47 is covered with the big belt pulley 6 and small belt pulley 7 and driving belt, to protect belt drive Structure.The bearing 30 is thrust bearing 30 or pressure bearing 30.Larger axial force during adapting to work.

Wherein, the water cavity 35 of cooling heat transferring case 24 can be connected on the water supply of factory by its water inlet 40 and delivery port 41 On pipeline（External water inlet pipe now described previously and external outlet pipe are the water supply line of factory）, naturally it is also possible to make into water Mouth 40 is connected on the water supply line of factory（Water supply line is as external water inlet pipe）, and delivery port 41 is connected external draining Pipeline（Drainage pipeline is as external outlet pipe）.Thermometer 16 is used for monitoring the operating temperature in magnetic separation grain bulking machine.Expansion The front end external diameter of control first 20 is less than the front inner diameter of discharging opening 18, and the rear end external diameter of expansion control first 20 is more than discharging opening 18 Front inner diameter and the back end inside diameter for being less than discharging opening 18；So, expansion control first 20 can stretch into tubaeform discharging opening 18.Adjust The front and back position of discharging opening 18 is stretched into section expansion control first 20, can be with the width of tapping channel 21.Referring to accompanying drawing 5, expansion control First 20 position is more forward, and tapping channel 21 is narrower, and more rearward, tapping channel 21 is wider for the position of expansion control first 20. Therefore, by controlling the front and back position of expansion control first 20, the thickness degree after being handled with control material.

The setting of oil pipe is overflowed, can ensure that the lubricating oil in bearing chamber has certain oil level（Highly）, so as to ensure Lubrication is good.The height of oil pipe upper end is overflowed in regulation, can adjust the oil level and oil mass of lubricating oil in bearing room.

Preceding helixseal and rear screw are sealed oppositely oriented and moistened when main shaft rotates to direction push in the middle part of bearing chamber Lubricating oil, the rotation of main shaft at work can be utilized, lubricating oil is brought in the middle part of bearing chamber, prevents lubricating oil from being flowed out along main shaft Bearing chamber, there is better seal effect compared with traditional sealing ring.

The concrete structure of pressing screw, it is easy to assemble, the length of pressing screw can be adjusted as needed（Assembled more pressing screw sections）, Suitable for manufacturing the magnetic separation grain bulking machine of different model.

In use, start motor 9, by material（Such as corn and soybean grain）Put into by charging aperture, material enters along V-shaped Expects pipe 4 falls into press chamber 3 after turning back, passing through electromagnet 44（It is powered during work）When, the iron class impurity in material is by electromagnetism Iron 44 is adsorbed onto on the tube wall of feed pipe 4, prevents iron class impurity from falling into press chamber 3 so as to influence crudy.After motor 9 starts, Pressing screw 10 is driven to rotate by belt transmission, pressing screw 10 drives spiral pushing blade 12 thereon to rotate integrally.

After material falls into press chamber 3, spiral pushing blade 12 promotes material to move from the front to the back in rotation.Because spiral pushes away The pitch of blade 12 is sent to be gradually reduced from the front to the back, therefore the amount that material is compressed during spiral pushing material in rotation gradually increases Greatly, pressure gradually rises, and is advantageous to being smoothed out for puffing process.Material is in moving process, when by stirring gear stick 13 It is stirred gear stick 13 to be stopped, so as to be stirred, material is distributed more uniform, lifts processing quality.

Connecting screw 23 connects pressing screw 10 and main shaft 22 in the axial direction, and buckle structure diametrically connects pressing screw 10 and main shaft 22 so that be suitable to transmit high torque between pressing screw 10 and main shaft 22, be also less likely to be damaged after long-term work.This attachment structure Also it is highly convenient for connecting and dismantling.

After motor 9 starts, start scavenge oil pump 37, the oil in oil pocket 34 passes through oil filter 39, oil inlet pipe 38, the and of scavenge oil pump 37 Enter bearing chamber after oil return pipe 36.When the oil level in bearing chamber higher than overflow oil pipe 33 when, lubricating oil through spilling oil pipe again to Lower inflow oil pocket 34, and when flowing through profit dividing plate 26, heat exchange occurs with the water in water cavity 35 and is cooled.After cooling Lubricating oil is pumped back to bearing chamber by oil return again, so as to prevent the high oil temperature of lubricating oil in bearing chamber from bringing harm.

The setting of thermometer 16 and pressure gauge 17, it is easy to the temperature and pressure before material is expanded in monitoring work, so as to more Accurately adjustment work process, improve expansion effect.When material pushes to discharging opening 18 by spiral pushing blade 12, control is inflated System first 20 is stopped, discharging boot 8 can only be entered by tapping channel 21.When material enters discharging boot 8, pressure drops rapidly It is low, material（Grain grain）It is interior in the moisture instant vaporization of superheat state so as to which violent explosion occur, obtain material expanded.

Above example is only to illustrative and not limiting the technical solution of the utility model, although with reference to above-described embodiment pair The utility model is described in detail, it will be understood by those within the art that：The utility model can still be entered Row modification or equivalent substitution, without departing from any modification or partial replacement of spirit and scope of the present utility model, it all should Cover among right of the present utility model.

Claims (3)

1. magnetic separation grain bulking machine, including support, support is connected with columnar press chamber by some spaced support frames, Press chamber one end is feed end and the other end is discharge end；The feed end of press chamber is communicated with feed pipe upwards, is set at the top of feed pipe There is charging aperture；It is on front side of it and using press chamber discharge end side as rear side using press chamber feed end side, motor is provided with front side of support, The output shaft of motor is provided with small belt pulley, it is characterised in that：

Small belt pulley is connected with big belt pulley by driving belt；Pressing screw assembly is provided with the inner chamber of press chamber, pressing screw assembly includes Pressing screw in a tubular form, screw rod is equipped with pressing screw, pressing screw outer wall is provided with spiral pushing blade；The spiral shell of the spiral pushing blade Away from being gradually reduced from the front to the back；

Separation seal is fixedly connected with multiple stirring gear sticks for being used to stir material from the front to the back at the top of press chamber, each stirring gear stick Press chamber is stretched out in outer end and press chamber is stretched into the inner；With the axially middle part of press chamber for boundary, in some stirring gear sticks anterior positioned at press chamber Provided with steam inlet tube, stirring gear stick and the steam pipework for connecting outside are stretched out in the outer end of steam inlet tube, and stirring gear stick is inner It is communicated with steam inlet tube and the steam vent of press chamber inner chamber；Thermometer is provided with least one stirring gear stick of press chamber back segment；Press chamber Back segment is connected with pressure gauge, and pressure gauge stretches out press chamber upwards；

Press chamber rear end is fixedly connected with discharging opening, and discharging opening is connected with discharging boot in rear big preceding small toroidal, discharging opening； The pressing screw is coaxially set with the main shaft and the two is linked together by connecting screw, and connecting screw is located at main shaft and squeezing It is threadedly coupled at the axis of spiral shell and with pressing screw；

The outer rim key connection of the centre bore of big belt pulley and the main shaft；Support front end is provided with support, and main shaft passes through bearing and axle Bearing is connected on support；

The feed pipe is V-shaped broken pipe, and the tube wall lateral surface of every section of V-shaped feed pipe is equipped with magnetic separation electromagnet；Magnetic It is clear to expect baffle plate be hinged from clear material baffle plate of the feed pipe at electromagnet provided with residue-removing opening and for closing the residue-removing opening Or it is spirally connected or the mode of clamping is detachably connected on feed pipe.

2. magnetic separation grain bulking machine according to claim 1, it is characterised in that：The press chamber includes some press chamber sections, phase Linked together between adjacent press chamber section by flange arrangement；The pressing screw includes some pressing screw sections in a tubular form, adjacent pressing screw section Between snap connection together；The screw rod of wearing is through all pressing screw section threaded connections of all pressing screw Duan Bingyu.

3. magnetic separation grain bulking machine according to claim 1, it is characterised in that：Pressing screw front end passes through buckle structure and main shaft It is connected, buckle structure includes being arranged on the spiral buckle of pressing screw front end and is arranged on the spiral buckle of rear-end of spindle, after main shaft The spiral buckle at end is mutually adapted with the spiral buckle of pressing screw front end.