CN110540390B

CN110540390B - Processing technology for preparing high-strength concrete

Info

Publication number: CN110540390B
Application number: CN201910919773.2A
Authority: CN
Inventors: 李永建
Original assignee: Poyang Hengji Building Materials Co Ltd
Current assignee: Poyang Hengji Building Materials Co ltd
Priority date: 2017-12-25
Filing date: 2017-12-25
Publication date: 2020-08-14
Anticipated expiration: 2037-12-25
Also published as: CN108059398B; CN108059398A; CN110540390A

Abstract

The invention discloses a processing technology for preparing high-strength concrete, which comprises the following steps: (1) preparing raw materials: taking cement, gravel, water, a water reducing agent, phenolic fiber and montmorillonite; the gravel is obtained by crushing the construction waste through a crushing device; (2) dry mixing: putting cement, gravel, a water reducing agent, phenolic fiber and montmorillonite into a mixer for dry material premixing, and uniformly mixing to obtain a mixture A; (3) wet mixing: and putting the mixture A into a stirrer, adding water and fine aggregate into the stirrer, and uniformly stirring to obtain the pasty concrete. According to the invention, dry mixing operation is carried out between wet mixing, so that the mixing uniformity of dry powder materials is higher during mixing, and various materials are guaranteed to be mixed together.

Description

Processing technology for preparing high-strength concrete

Technical Field

The invention belongs to the technical field of buildings, and particularly relates to a processing technology for preparing high-strength concrete.

Background

A large amount of gravels are needed in the preparation process of concrete, and due to shortage of gravels resources, people begin to replace the gravels with the gravels obtained by crushing construction waste materials so as to meet the demand of construction engineering on the gravels. However, the existing crushing method is difficult to realize fine crushing of the construction waste, and generally needs a plurality of crushing procedures to obtain crushed stones with smaller volume, so that the processing time is long, and the working efficiency is low; a plurality of different processing devices are needed, so that the equipment investment cost is high and the energy consumption is large; the finally obtained broken stone has low qualification rate and is difficult to meet the requirement of processing excellent concrete; and the strength of the concrete prepared by the traditional method is lower, so that the firmness degree of the building is influenced.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a processing technology for preparing high-strength concrete, which has high strength of the prepared concrete and saves resources.

In order to achieve the purpose, the invention adopts the following technical scheme: a processing technology for preparing high-strength concrete comprises the following steps:

(1) preparing raw materials: taking cement, gravel, water, a water reducing agent, phenolic fiber and montmorillonite; the sand stone is obtained by crushing the construction waste through a crushing device, and the particle size of the sand stone is 8-10 mm; the water reducing agent comprises the following components in parts by weight: 40-45 parts of polycarboxylic acid mother liquor, 6-10 parts of slump retaining agent, 2.5-3.5 parts of borax, 4-6 parts of plastic retaining agent and 35-40 parts of water;

(2) dry mixing: putting cement, gravel, a water reducing agent, phenolic fiber and montmorillonite into a mixer for dry material premixing, and uniformly mixing to obtain a mixture A; the mixing step of the dry mixing is as follows: firstly, mixing cement, gravel, a water reducing agent and phenolic fibers, and then adding montmorillonite for mixing; the temperature of the mixer in the dry mixing operation is 30-35 ℃, and a spray gun is arranged on the mixer and can spray gas with the temperature of 28-32 ℃ to the materials in the mixer in the working process of the mixer;

(3) wet mixing: putting the mixture A into a stirrer, adding water and fine aggregate into the stirrer, and then uniformly stirring to obtain a pasty concrete raw material, adding quartz sand: after quartz is treated, grinding the quartz to obtain quartz sand, then putting the quartz sand into the concrete raw material, starting a stirrer to continuously stir the material, and obtaining a concrete finished product after the quartz sand and the concrete raw material are uniformly mixed; the specific treatment of the quartzite is as follows:

a: washing with water: cleaning the quartzite with clear water to remove impurities on the surface of the quartzite;

c: and (3) drying: draining after cleaning is finished, and drying the water on the surface of the quartzite by a dryer;

d: grinding: crushing the dried quartzite by using a wheel mill, and sieving the crushed quartzite by using a 100-mesh sieve to obtain quartzite;

the crushing device comprises a rack, a barrel body which is rotatably arranged on the rack, a first driving piece for driving the barrel body to rotate, a first crushing roller and a second crushing roller which are arranged in the barrel body, and a driving part; the driving component comprises a second driving piece for driving the first crushing roller to rotate and a third driving piece for driving the second crushing roller to rotate in the opposite direction of the first crushing roller; the barrel is provided with a discharge hole and an opening and closing door which can be connected outside the barrel in a turnover mode to open or close the discharge hole; a screening device is arranged on the discharge port; the screening device comprises a screening element and a screening assisting component for driving the screening element to vibrate; an elastic swinging structure is arranged between the screening element and the screening assisting element; a first accommodating cavity and a second accommodating cavity are formed in the cylinder body; the first accommodating cavity and the second accommodating cavity are respectively positioned on the left side and the right side of the discharge hole, and are communicated with the discharge hole; the sieve-assisting component is arranged in the first accommodating cavity, and the second accommodating cavity is used for inserting the sieve element into the discharge port; the screening assisting component comprises a vibrating piece and a vibrating seat, the vibrating seat is connected with an output shaft of the vibrating piece, a groove matched with the elastic swing structure is formed in the vibrating seat, and an elastic layer is arranged on the outer wall of the vibrating seat and made of rubber; the elastic swinging structure comprises a transmission seat, a connecting arm and an elastic section; the shape and size of the transmission seat are equal to those of the groove, and the transmission seat is directly clamped in the groove; the connecting arm is made of stainless steel and is arranged between the transmission seat and the screening element; the elastic section is arranged on the connecting arm, and a plurality of arches are uniformly arranged on the connecting arm at intervals to form the elastic section; the first chamber that holds is equipped with positioning element in, this positioning element includes the locating plate, locates flaring board and one end on the locating plate act on the extensible member on the first intracavity wall that holds, the other end of this extensible member acts on the locating plate.

In the invention, the sandstone is directly prepared from the construction waste, so that the resource is effectively saved, the construction waste is fully utilized, the treatment cost of the construction waste is reduced, and the waste is changed into valuable; dry mixing operation is carried out between wet mixing, so that the mixing uniformity of dry powder materials is higher during mixing, and various materials are guaranteed to be mixed together; compared with a mode of directly mixing various materials by wet mixing, the method is not easy to cause caking among the materials or form slurry-like materials at first, so that the materials are difficult to be uniformly mixed together in the later period, the materials are ensured to be uniformly mixed, and the prepared concrete has good performance; the quartz mortar is used as a raw material, so that the acid resistance, the corrosion resistance and the strength of the concrete are effectively enhanced, and the manufactured concrete has the characteristic of good acid corrosion resistance and long service life; the requirement of processing high-quality concrete for the size of the sand particles is met;

the viscosity of the montmorillonite is high, and the montmorillonite is added later, so that the problem that materials are bonded together and cannot be uniformly mixed can be effectively avoided; the temperature is set to be 30-35 ℃, so that the condition that the materials are partially softened and then bonded due to high temperature is avoided, and the uniform mixing effect is ensured; by spraying the gas, the adhered materials can be fully scattered in the mixing process, the materials cannot be uniformly mixed due to adhesion, and the mixing effect is further improved; part of impurities in the quartzite are effectively removed through cleaning, so that the prepared quartzite mortar is purer, and the acid resistance is more excellent; the grinding is carried out by the edge runner mill, and the grinding wheel of the edge runner mill can be made of quartz, so that metal is prevented from being mixed into quartz sand in the grinding process, the purity of the finally prepared quartz stone mortar is further improved, and the strength of the finally prepared concrete is improved; through the setting of sieving and filtering the device, can carry out the choice to the material of ejection of compact, satisfy the material of the rubble size of final needs and can outwards discharge, and unsatisfied will continue to be stayed in the barrel, carry out processing next time, guarantee that discharged material is the certified products.

Different power source drives are ensured between the barrel body and the crushing roller, and the crushing roller and the barrel body can maintain different rotating speeds and rotating frequencies, so that the crushing effect is further improved; through the arrangement of the screening device, the discharged materials can be carefully selected, the materials meeting the final required size of the crushed stones can be discharged outwards, the unsatisfied materials can be continuously left in the cylinder body for next processing, and the discharged materials are all qualified products; through the matching of the sieve-assisting component and the elastic swing structure, the sieve-filtering piece can vibrate during discharging, so that the filtered material can bounce on the sieve-filtering piece, the filtering effect is good, the situation that the sieve-filtering piece is blocked is not easy to occur, and the failure rate is low; the elastic swinging structure is driven to vibrate through the vibration of the vibration seat, so that the vibration amplitude of the elastic swinging structure is increased, the vibration of the screening piece in a larger amplitude range is ensured, and the screening effect is better; the screening element can vibrate in the left and right directions and can move in the up and down directions, and even if materials are clamped into the screening holes, the screening element can be thrown out in the up and down swinging process, so that the possibility of blockage of the screening element is further reduced, the failure rate is reduced, and the service life of equipment is prolonged; through the arrangement of the positioning plate, an overlarge gap is prevented from being formed between the screening element and the inner wall of the accommodating groove, dust is not easy to enter the accommodating cavity, and the damage to the vibrating element is avoided; the positioning plate is connected with the inner wall of the accommodating groove through the telescopic piece, so that the sieving and filtering piece can still float up and down when being matched with the positioning plate, good fitting of the sieving and filtering piece and the positioning plate can be guaranteed, and good sieving and filtering effects can be guaranteed; through the setting of elastic layer, the floating range of effective increase vibration seat, the piece can produce wobbling range is strained in the increase sieve, reduces the jam rate when improving the sieve and strain the effect.

In conclusion, the invention has the following beneficial effects: dry mixing operation is carried out between wet mixing, so that the mixing uniformity of dry powder materials is high during mixing; the building waste is directly crushed to obtain the sandstone, so that waste of non-renewable resources is avoided, and energy conservation and consumption reduction are realized; (ii) a The quartz stone mortar is used as a raw material, so that the acid resistance, the corrosion resistance and the strength of the concrete are effectively enhanced.

Drawings

Fig. 1 is a schematic structural view of the crushing apparatus of the present invention.

Fig. 2 is a cross-sectional view of the cartridge.

Fig. 3 is an enlarged view at B in fig. 2.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

Example 1

A processing technology for preparing high-strength concrete comprises the following steps: (1) preparing raw materials: 500kg of cement, 1000kg of sandstone, 160kg of water, 6kg of water reducing agent, 8kg of phenolic fiber and 60kg of montmorillonite are taken; the building waste is crushed by a crushing device to obtain sand, and the particle size of the sand is 8 mm; the water reducing agent comprises the following components in parts by weight: 40 parts of polycarboxylic acid mother liquor, 6 parts of slump retaining agent, 2.5 parts of borax, 4 parts of plastic retaining agent and 35 parts of water; the slump retaining agent and the plastic retaining agent can be directly purchased on the market, so that the materials are not specifically limited; (2) dry mixing: putting cement, gravel, a water reducing agent, phenolic fiber and montmorillonite into a mixer for dry material premixing, and uniformly mixing to obtain a mixture A; the concrete mixing step is that cement, sand and stone, water reducing agent and phenolic fiber are mixed, and then montmorillonite is added for mixing; keeping the temperature in the mixer at 30 ℃ during mixing; preferably, the mixer is provided with a spray gun which is directly purchased from the market, a nozzle of the spray gun extends into the mixer, and the spray gun is connected with the heater, so that gas with the temperature of 28 ℃ can be sprayed to the materials in the mixer in the working process of the mixer to break up the materials; (3) wet mixing: putting the mixture A into a stirrer, adding water and fine aggregate into the stirrer, and uniformly stirring to obtain a pasty concrete raw material; (4) adding quartz sand: after treating the quartzite, grinding the quartzite to prepare quartz sand; specifically, the specific treatment of the quartzite is as follows: a: washing with water: cleaning the quartzite with clear water to remove impurities on the surface of the quartzite; c: and (3) drying: draining after cleaning is finished, and drying the water on the surface of the quartzite by a dryer; d: grinding: crushing the dried quartzite by using a wheel mill, and sieving the crushed quartzite by using a 100-mesh sieve to obtain quartzite; then adding quartz sand into the concrete raw material, starting a stirrer to continuously stir the material, and obtaining a concrete finished product after the quartz sand and the concrete raw material are uniformly mixed; the mixer and the stirrer are both the prior art and are not repeated.

As shown in fig. 1-3, specifically, the crushing device 3 is used for crushing materials, the stirring device 4 is a free-fall mixer directly purchased from the market, and the crushed materials are uniformly mixed with cement and water by the stirring device to obtain concrete; specifically, the crushing device 3 comprises a frame 31, a cylinder 32, a first driving piece 33, a first crushing roller 34, a second crushing roller 35 and a driving part; the cylinder body is made of stainless steel, and the cylinder body 32 is rotatably arranged on the rack; the first driving part 33 is a motor directly purchased from the market, is fixedly arranged on the rack, and is driven to rotate by the first driving part; the first crushing roller 34 and the second crushing roller 35 are arranged in the cylinder body, the first crushing roller 34 and the second crushing roller 35 are gear rollers directly purchased from the market, and the structure is not repeated; the driving parts comprise a second driving part 36 and a third driving part 37, the second driving part 36 and the third driving part 37 are motors directly purchased from the market, the second driving part 36 is fixedly arranged on the rack, and one end of the first crushing roller 34 penetrates through the barrel body and then is connected with the second driving part, so that the first crushing roller rotates under the driving of the second driving part; the third driving part 37 is fixedly arranged on the frame, and one end of the second crushing roller 35 penetrates through the barrel body and then is connected with the third driving part 37, and is driven by the third driving part 37 to rotate; and the second and

third driving members

36 and 37 are rotated in opposite directions so as to drive the first and second crushing

rollers

34 and 35 to rotate in opposite directions.

The cylinder 32 is provided with a discharge hole 321 and an opening and closing door 322, one end of the opening and closing door 322 is connected outside the cylinder in a turnover way, and the other end is detachably connected with the cylinder through a lock catch, so that the discharge hole can be opened or closed; further, a screening device 5 is arranged on the discharge port 321; the screening device 5 comprises a screening element 51 and a screening assisting element 52 for driving the screening element to vibrate; an elastic swinging structure 6 is arranged between the screening element 51 and the screening assisting element 52; a first accommodating cavity 323 and a second accommodating cavity 324 are arranged in the cylinder body 32; the first accommodating cavity 323 and the second accommodating cavity 324 are respectively positioned on the left side and the right side of the discharge hole, and the first accommodating cavity 323 and the second accommodating cavity 324 are both communicated with the discharge hole 321; the sieve-aid component is arranged in the first accommodating cavity 323, and the second accommodating cavity 324 is used for inserting the sieve element into the discharge port.

The screening piece is a grid plate made of stainless steel, the size of the grid plate is determined according to the size of the material needing to be screened, and the screening piece is not limited specifically; the sieving assisting component 52 comprises a vibrating piece 521 and a vibrating seat 522, the vibrating piece is a vibration exciter directly purchased from the market, and the vibrating seat 522 is connected with an output shaft of the vibrating piece, so that the vibrating piece can vibrate under the driving of the vibrating piece; the vibration seat 522 is provided with a groove 523 matched with the elastic swing structure, preferably, the outer wall of the vibration seat 522 is provided with an elastic layer 524, and the elastic layer is made of rubber; specifically, the elastic swinging structure 6 includes a transmission seat 61, a connecting arm 62 and an elastic segment 63; the shape and size of the transmission seat 61 are equal to those of the groove, and the transmission seat 61 is directly clamped in the groove; the connecting arm 62 is made of stainless steel, is arranged between the transmission seat and the screening element and is used for connecting the transmission seat and the screening element; the elastic section 63 is provided on the connecting arm, and specifically, a plurality of arches 621 are uniformly arranged on the connecting arm 62 at intervals to form the elastic section 63, and the arches can be formed by directly bending the connecting arm.

Preferably, the upper and lower inner walls of the first accommodating groove 323 are respectively provided with a positioning part 7, the positioning part 7 comprises a positioning plate 71 made of plastic, an expansion part 72 and a flaring plate 73 made of plastic, the flaring plate 73 is obliquely connected to one end of the positioning plate close to the discharge port, and the expansion part 72 is a spring and is arranged between the support plate and the inner wall of the first accommodating groove, so that the positioning plate can elastically float; further, a sponge layer 325 is adhered to the bottom surface of the second receiving chamber 324, so that the filter member can move up and down when placed on the sponge layer.

Example 2

A processing technology for preparing high-strength concrete comprises the following steps: (1) preparing raw materials: 500kg of cement, 1000kg of sandstone, 160kg of water, 6kg of water reducing agent, 8kg of phenolic fiber and 60kg of montmorillonite are taken; the building waste is crushed by a crushing device to obtain sand, and the particle size of the sand is 10 mm; the water reducing agent comprises the following components in parts by weight: 45 parts of polycarboxylic acid mother liquor, 10 parts of slump retaining agent, 3.5 parts of borax, 6 parts of plastic retaining agent and 40 parts of water; the slump retaining agent and the plastic retaining agent can be directly purchased on the market, so that the materials are not specifically limited; (2) dry mixing: putting cement, gravel, a water reducing agent, phenolic fiber and montmorillonite into a mixer for dry material premixing, and uniformly mixing to obtain a mixture A; the concrete mixing step is that cement, sand and stone, water reducing agent and phenolic fiber are mixed, and then montmorillonite is added for mixing; keeping the temperature in the mixer at 35 ℃ during mixing; preferably, the mixer is provided with a spray gun which is directly purchased from the market, a nozzle of the spray gun extends into the mixer, and the spray gun is connected with the heater, so that gas with the temperature of 32 ℃ can be sprayed to the materials in the mixer in the working process of the mixer to break up the materials; (3) wet mixing: putting the mixture A into a stirrer, adding water and fine aggregate into the stirrer, and uniformly stirring to obtain a pasty concrete raw material; (4) adding quartz sand: after treating the quartzite, grinding the quartzite to prepare quartz sand; specifically, the specific treatment of the quartzite is as follows: a: washing with water: cleaning the quartzite with clear water to remove impurities on the surface of the quartzite; c: and (3) drying: draining after cleaning is finished, and drying the water on the surface of the quartzite by a dryer; d: grinding: crushing the dried quartzite by using a wheel mill, and sieving the crushed quartzite by using a 100-mesh sieve to obtain quartzite; then adding quartz sand into the concrete raw material, starting a stirrer to continuously stir the material, and obtaining a concrete finished product after the quartz sand and the concrete raw material are uniformly mixed; the mixer and the stirrer are both the prior art and are not repeated.

The structure of the crushing device in this embodiment is the same as that of embodiment 1, and the description thereof is omitted.

Example 3

A processing technology for preparing high-strength concrete comprises the following steps: (1) preparing raw materials: 500kg of cement, 1000kg of sandstone, 160kg of water, 6kg of water reducing agent, 8kg of phenolic fiber and 60kg of montmorillonite are taken; the building waste is crushed by a crushing device to obtain sand, and the particle size of the sand is 8 mm; the water reducing agent comprises the following components in parts by weight: 45 parts of polycarboxylic acid mother liquor, 6 parts of slump retaining agent, 2.5 parts of borax, 6 parts of plastic retaining agent and 40 parts of water; the slump retaining agent and the plastic retaining agent can be directly purchased on the market, so that the materials are not specifically limited; (2) dry mixing: putting cement, gravel, a water reducing agent, phenolic fiber and montmorillonite into a mixer for dry material premixing, and uniformly mixing to obtain a mixture A; the concrete mixing step is that cement, sand and stone, water reducing agent and phenolic fiber are mixed, and then montmorillonite is added for mixing; keeping the temperature in the mixer at 32 ℃ during mixing; preferably, the mixer is provided with a spray gun which is directly purchased from the market, a nozzle of the spray gun extends into the mixer, and the spray gun is connected with the heater, so that gas with the temperature of 30 ℃ can be sprayed to the materials in the mixer in the working process of the mixer to scatter the materials; (3) wet mixing: putting the mixture A into a stirrer, adding water and fine aggregate into the stirrer, and uniformly stirring to obtain a pasty concrete raw material; (4) adding quartz sand: after treating the quartzite, grinding the quartzite to prepare quartz sand; specifically, the specific treatment of the quartzite is as follows: a: washing with water: cleaning the quartzite with clear water to remove impurities on the surface of the quartzite; c: and (3) drying: draining after cleaning is finished, and drying the water on the surface of the quartzite by a dryer; d: grinding: crushing the dried quartzite by using a wheel mill, and sieving the crushed quartzite by using a 100-mesh sieve to obtain quartzite; then adding quartz sand into the concrete raw material, starting a stirrer to continuously stir the material, and obtaining a concrete finished product after the quartz sand and the concrete raw material are uniformly mixed; the mixer and the stirrer are both the prior art and are not repeated.

It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

1. A processing technology for preparing high-strength concrete comprises the following steps:

preparing raw materials: taking cement, gravel, water, a water reducing agent, phenolic fiber and montmorillonite; the sand stone is obtained by crushing the construction waste through a crushing device (3), and the particle size of the sand stone is 8-10 mm; the water reducing agent comprises the following components in parts by weight: 40-45 parts of polycarboxylic acid mother liquor, 6-10 parts of slump retaining agent, 2.5-3.5 parts of borax, 4-6 parts of plastic retaining agent and 35-40 parts of water;

dry mixing: putting cement, gravel, a water reducing agent, phenolic fiber and montmorillonite into a mixer for dry material premixing, and uniformly mixing to obtain a mixture A; the mixing step of the dry mixing is as follows: firstly, mixing cement, gravel, a water reducing agent and phenolic fibers, and then adding montmorillonite for mixing; the temperature of the mixer in the dry mixing operation is 30-35 ℃, and a spray gun is arranged on the mixer and can spray gas with the temperature of 28-32 ℃ to the materials in the mixer in the working process of the mixer;

wet mixing: putting the mixture A into a stirrer, adding water and fine aggregate into the stirrer, and then uniformly stirring to obtain a pasty concrete raw material, adding quartz sand: after quartz is treated, grinding the quartz to obtain quartz sand, then putting the quartz sand into the concrete raw material, starting a stirrer to continuously stir the material, and obtaining a concrete finished product after the quartz sand and the concrete raw material are uniformly mixed; the specific treatment of the quartzite is as follows:

the crushing device (3) comprises a rack (31), a barrel body (32) which is rotatably arranged on the rack, a first driving piece (33) which is used for driving the barrel body to rotate, a first crushing roller (34) and a second crushing roller (35) which are arranged in the barrel body, and a driving part; the driving component comprises a second driving piece (36) for driving the first crushing roller (34) to rotate and a third driving piece (37) for driving the second crushing roller (35) to rotate in the opposite direction of the first crushing roller; the cylinder body (32) is provided with a discharge hole (321) and an opening and closing door (322) which can be connected outside the cylinder body in a turnover mode to open or close the discharge hole; a screening device (5) is arranged on the discharge hole (321); the screening device (5) comprises a screening element (51) and a screening assisting component (52) for driving the screening element to vibrate; an elastic swing structure (6) is arranged between the screening element (51) and the screening assisting component (52); a first accommodating cavity (323) and a second accommodating cavity (324) are arranged in the cylinder body (32); the first accommodating cavity (323) and the second accommodating cavity (324) are respectively positioned on the left side and the right side of the discharge hole, and the first accommodating cavity (323) and the second accommodating cavity (324) are communicated with the discharge hole (321); the sieve-assisting component is arranged in the first accommodating cavity (323), and the second accommodating cavity (324) is used for inserting the sieve element into the discharge port; the sieve-assisting component (52) comprises a vibrating piece (521) and a vibrating seat (522), the vibrating seat (522) is connected with an output shaft of the vibrating piece, a groove (523) matched with the elastic swing structure is arranged on the vibrating seat (522), and an elastic layer (524) is arranged on the outer wall of the vibrating seat (522) and made of rubber; the elastic swing structure (6) comprises a transmission seat (61), a connecting arm (62) and an elastic section (63); the shape and size of the transmission seat (61) are equal to those of the groove, and the transmission seat (61) is directly clamped in the groove; the connecting arm (62) is made of stainless steel and is arranged between the transmission seat and the screening element; the elastic section (63) is arranged on the connecting arm, and a plurality of arches (621) are uniformly arranged on the connecting arm (62) at intervals to form the elastic section (63); a positioning part (7) is arranged in the first accommodating cavity (323), the positioning part (7) comprises a positioning plate (71), a flaring plate (73) arranged on the positioning plate (71) and a telescopic piece (72) with one end acting on the inner wall of the first accommodating cavity (323), and the other end of the telescopic piece (72) acts on the positioning plate (71).