CN112945666A

CN112945666A - High-moisture-content soil vibration triaxial test sample preparation method and sample preparation device

Info

Publication number: CN112945666A
Application number: CN202110134933.XA
Authority: CN
Inventors: 马莎; 刘聪聪; 张润华; 成益洋; 王世帆; 王甲怡; 王欢; 李博
Original assignee: North China University of Water Resources and Electric Power
Current assignee: North China University of Water Resources and Electric Power
Priority date: 2021-02-01
Filing date: 2021-02-01
Publication date: 2021-06-11

Abstract

The invention relates to the technical field of test correlation, and discloses a high-moisture-content soil vibration triaxial test sample preparation method and a sample preparation device. According to the invention, the movable base and the fixed base are convenient to disassemble through the pins, so that the movable base and the fixed base can be disassembled from the characteristic of high-moisture-content soil, the layered compaction of the sample is finally realized, and the problems that the preparation of the weak sample is difficult and the sample is not easy to take out completely are solved.

Description

High-moisture-content soil vibration triaxial test sample preparation method and sample preparation device

Technical Field

The invention relates to the relevant technical field of tests, in particular to a sample preparation method and a sample preparation device for a high-moisture-content soil vibration triaxial test.

Background

The dynamic characteristic of the sand of the railway roadbed engineering is important for the exertion of the roadbed function, the vibration triaxial test is one of the common methods for researching the dynamic characteristic of the soil body, and a scientific test basis is provided for the indoor research on the deformation characteristic and the strength characteristic of the soil body under the action of dynamic load. The method comprises the following steps that an indoor frequently-performed vibration triaxial test comprises a dynamic deformation characteristic test and a dynamic strength test, wherein the dynamic deformation characteristic test is used for researching the relation between dynamic stress and dynamic strain of a soil body and the change rule of dynamic shear modulus and damping ratio; the dynamic strength test is used for researching the development trend of dynamic pore water pressure of a soil body under the action of dynamic load, measuring dynamic cohesion and dynamic internal friction angle of the soil body and providing a solution for the dynamic reaction problem, the dynamic stability problem and the geotechnical anti-seismic and anti-seismic problems of the soil body in the actual engineering.

Before a vibration triaxial test is carried out, a test sample with a corresponding size is prepared, the vibration triaxial test sample is a standard cylindrical test sample, and according to the existing specification 'geotechnical test method standard' (GB/T50123-. According to the section of 'preparation and saturation of a sample' in the current specification, soil samples with different water contents are prepared according to corresponding steps, and the soil samples are compacted in a mould in a layering mode by adopting a compaction method.

The current system appearance device has a lot, sample preparation device commonly used is to lower moisture content, the sample preparation effect of higher dry density is fine, but to preparing the moisture content higher, the sample that dry density is lower, the effect is unsatisfactory, especially to inviscid soil sample, because cohesively between the inviscid soil granule power is very little, appear "fall end" phenomenon easily, be difficult to prepare complete standard cylindrical sample, in addition in sample layering compaction process, easily closely combine together with the sleeve after the compactor is pressed to predetermined position, be difficult to take out the compactor.

Simultaneously, current system appearance equipment is at the in-process of work, in order to guarantee that three lamella moulds are changeed in breaking away from, therefore it is relatively not enough when making three lamella moulds fixed, cause the soil in three lamella moulds after the pressurized, its soil can be followed both ends and run off, simultaneously, three lamella moulds easily take place to empty, thereby influence the shaping of cylinder, meanwhile, at compactor extruded in-process, because there is gas in the loose soil, therefore at the extruded in-process, gaseous condensation can make the compactor after the extrusion, the phenomenon of bounce-back can appear, therefore lead to the phenomenon of its cylinder local cavity to appear at the in-process of preparing.

Disclosure of Invention

Aiming at the defects of the existing triaxial test sample preparation device in the background technology in the using process, the invention provides the high-moisture-content soil vibration triaxial test sample preparation method and the sample preparation device, which have the advantages of difficult preparation of weak samples, difficulty in complete taking out, stable three-petal mold and movable base, installation detection and automatic push-out, increased pressure maintaining capability of a compactor, convenience in taking out of the compactor and adaptability to different types of samples, and solve the technical problems in the background technology.

The invention provides the following technical scheme: the utility model provides a high moisture content soil vibration triaxial test system appearance device, includes unable adjustment base, unable adjustment base surface one side movable mounting have with the movable base of unable adjustment base looks adaptation, and unable adjustment base's both sides respectively movable mounting have the locking stick, unable adjustment base's top both sides respectively swing joint has the pin, and movable base passes through pin and unable adjustment base fixed connection, the inner wall movable mounting of movable base has three lamella moulds, and the top movable mounting of three lamella moulds has the footstock, the both sides movable mounting of footstock has the drive handle, and the top movable mounting of footstock has the compactor, the groove of uncapping has been seted up to the surperficial both sides of footstock, and the both sides of footstock are equipped with the uncapping ware with uncapping groove looks adaptation.

Preferably, unable adjustment base's both sides movable mounting has the locking stick, and the home range of locking stick on unable adjustment base is zero degree to eighty degree, the lateral wall and the movable base swing joint of locking stick, and the top movable mounting of locking stick has the stick that steps up, the movable groove has been seted up respectively to the both sides of footstock, and the inner wall slidable mounting in movable groove has the drive handle, the screw with step up stick looks adaptation is seted up to the bottom of drive handle, the surface movable mounting of footstock has the ejector pin that is arranged in the groove of uncapping, and the top swing joint of the one end of ejector pin and drive handle.

Preferably, the inner wall both sides movable mounting of footstock has the pressure release piece, and the inner chamber of footstock is arranged in on the top of pressure release piece, one side and the drive handle sliding connection of pressure release piece, the top fixed mounting of pressure release piece has the pressure boost piece, and the material of pressure boost piece is soft rubber.

Preferably, one end of the driving handle is L-shaped, and the bent part of one end of the driving handle is provided with a round corner.

Preferably, the ejector rod is L-shaped, and the bottom end of the pressure relief block is provided with an arc matched with the driving handle.

Preferably, the movable base is C-shaped, and an arc groove matched with the locking rod is formed in the middle of one side of the movable base.

A sample preparation method of a high-moisture-content soil vibration triaxial test sample preparation device comprises the following steps:

s1, assembling all the components, connecting the locking rod and the driving handle to realize stable fixation of the movable base and the three-segment mold, dividing the movable base and the three-segment mold into three parts by mixing soil, and adding the three parts into the three-segment mold;

s2, pressing the soil in the three-segment mold from the top seat by selecting a proper compactor, so as to compact the soil in the three-segment mold, and meanwhile, extruding the compaction block through the side wall of the compactor to realize pressure maintaining;

s3, separating the locking rod from the driving handle and separating the locking rod from the driving handle through the pressure relief block to enable the bottom of the compactor to be communicated with external air flow, ejecting the compactor through the ejector rod, and separating the locking rod from the movable base;

and S4, pulling out the pin, so that the movable base is separated from the fixed base and is obliquely taken out of the fixed base through the three-petal mold.

The invention has the following beneficial effects:

1. according to the invention, the movable base and the fixed base are convenient to disassemble through the pins, so that the movable base and the fixed base can be disassembled from the characteristic of high-moisture-content soil, the layered compaction of the sample is finally realized, and the problems that the preparation of the weak sample is difficult and the sample is not easy to take out completely are solved.

2. According to the invention, the locking rods are arranged on two sides of the fixed base, and the driving handles are arranged on two sides of the footstock, so that the locking rods are in threaded connection with the driving handles to enable the three-piece mold to be extruded by the footstock and the fixed base, so that the upper end and the lower end of the three-piece mold are simultaneously stressed in the working process, the phenomenon that soil runs off from two ends is avoided, meanwhile, the movable base is clamped through the locking rods, the movable base can be ensured to stabilize the three-piece mold, and finally the purpose of stabilizing the three-piece mold and the movable base is achieved.

3. The ejector rod is movably arranged on the two sides of the ejector seat, so that the ejector rod can slide up and down on the ejector seat, and the ejector seat is arranged above the driving handle, so that when the driving handle and the locking rod are not tensioned, the ejector rod can be ejected out to enable the compactor to not work, and meanwhile, when the ejector seat is taken out, the compactor can be ejected out through the ejection of the ejector rod, and finally, the purposes of installation detection and automatic ejection are achieved.

4. The inner wall of the top seat is provided with the pressure relief block, so that the pressure relief block can limit the compactor through the driving handle, the compactor is driven to be fixed by the pressurizing block through the extrusion of the driving handle in the closing process of the pressure relief block, the pressure can be maintained after the compactor is pressed to be dead, the phenomenon of a cavity in soil is avoided, meanwhile, the bottom side of the compactor is communicated with external air flow through the pressure relief block in the process of lifting the compactor away from the pressure relief block through the driving handle, the phenomenon that the compactor is not easy to pull out due to negative pressure is avoided, and the purposes of increasing the pressure maintaining capacity of the compactor and facilitating the removal of the compactor are finally achieved.

5. According to the invention, the cover opening groove is formed in the top seat, and the cover opener is arranged at the same time, so that when the compactor is stuck, the cover opener tilts the compactor from the cover opening groove, thereby solving the problem that the compactor is not easy to take out, and ensuring the compactness of the prepared sample.

6. The invention realizes the possibility of preparing different types of samples by the same sample preparation device through the integral detachable design.

Drawings

FIG. 1 is a perspective view of the present invention;

FIG. 2 is an exploded view of the entire structure of the present invention;

FIG. 3 is a schematic cross-sectional view of the entire structure of the present invention;

FIG. 4 is an enlarged view of the point A in FIG. 3;

FIG. 5 is an enlarged view of the point B in FIG. 3 according to the present invention;

FIG. 6 is a schematic cross-sectional view at C-C of structure 3 of the present invention.

In the figure: 1. a fixed base; 2. a movable base; 3. a pin; 4. a locking bar; 5. a tightening rod; 6. three-petal mold; 7. a top seat; 8. a compactor; 9. opening the cover groove; 10. a cap opener; 11. a drive handle; 12. releasing the pressure block; 120. a pressure increasing block; 13. and a push rod.

Detailed Description

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, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

Referring to fig. 1-6, a high moisture content soil vibration triaxial test sample preparation device comprises a fixed base 1, a movable base 2 which is matched with the fixed base 1 is movably installed on one side of the surface of the fixed base 1, locking rods 4 are respectively movably installed on two sides of the fixed base 1, pins 3 are respectively movably connected on two sides of the top end of the fixed base 1, the movable base 2 is fixedly connected with the fixed base 1 through the pins 3, a three-petal mold 6 is movably installed on the inner wall of the movable base 2, a top seat 7 is movably installed on the top end of the three-petal mold 6, driving handles 11 are movably installed on two sides of the top seat 7, a compactor 8 is movably installed on the top end of the top seat 7, cover opening grooves 9 are formed on two sides of the surface of the top seat 7, cover opening devices 10 which are matched with the cover opening grooves 9 are arranged on two sides of the top seat 7, in order to solve the difficult problems of preparation, therefore through fixing its each part through the equipment and with its three lamella moulds 6, meanwhile, through convenient to detach between its movable base 2 and the unable adjustment base 1, make the getting rid of that three lamella moulds 6 can be direct, thereby be convenient for take out the system appearance in three lamella moulds 6, and simultaneously, for make compactor 8 appear blocking dead phenomenon after the suppression, thereby through having seted up uncapping groove 9 in the both sides of footstock 7, and pull in uncapping groove 9 through uncapping ware 10, realize that its compactor 8 breaks away from footstock 7, thereby prevent the dead phenomenon of compactor 8 blocks.

Meanwhile, in the application, the hollow cylinders of the top seat 7 have different diameters, and the diameter of the upper cylinder is larger than that of the compactor 8, so that the compactor 8 can smoothly compact the soil sample in the three-petal mold 6; the diameter of the lower cylinder is larger than that of the upper cylinder, so that the upper part of the three-petal mold 6 can partially extend into the top seat 7, and the purpose is to fix the three-petal mold 6 and prevent the three-petal mold 6 from shaking in the sample preparation process.

Wherein, both sides of the fixed base 1 are movably provided with a locking rod 4, the movable range of the locking rod 4 on the fixed base 1 is zero degree to eighty degree, the side wall of the locking rod 4 is movably connected with the movable base 2, the top end of the locking rod 4 is movably provided with a tightening rod 5, both sides of the footstock 7 are respectively provided with a movable groove, the inner wall of the movable groove is slidably provided with a driving handle 11, the bottom end of the driving handle 11 is provided with a screw hole matched with the tightening rod 5, the surface of the footstock 7 is movably provided with a mandril 13 positioned in the uncovering groove 9, one end of the mandril 13 is movably connected with the top end of the driving handle 11, in order to realize the stable fixation of the movable base 2 and the three-section mould 6, therefore, the locking rod 4 is in threaded connection with the driving handle 11, and the locking rod 4 is continuously tensioned with the driving handle 11, not only the side wall of the locking rod 4 can be tightly pressed, make activity base 2 hug closely its three lamella moulds 6 dead, meanwhile, through the pulling force between drive handle 11 and the locking stick 4, make the pressure between footstock 7 and unable adjustment base 1 increase, make three lamella moulds 6 can be firm fixed, and it, whether in-process fastening in order to detect between drive handle 11 and the locking stick 4 is connected, therefore through being equipped with ejector pin 13 at the inner wall of footstock 7, only fastening between its locking stick 4 and drive handle 11, and drive handle 11 card to minimum through locking stick 4, just can make the whole receipts of ejector pin 13 to the footstock 7, thereby the detection is realized to the length that stretches out of accessible ejector pin 13, when its ejector pin 13 is not all received, its ejector pin 13 can prevent the whereabouts of compactor 8, cause the unable normal position of suppression of compactor 8.

Wherein, the two sides of the inner wall of the top seat 7 are movably provided with the pressure relief block 12, the top end of the pressure relief block 12 is arranged in the inner cavity of the top seat 7, one side of the pressure relief block 12 is connected with the driving handle 11 in a sliding way, the top end of the pressure relief block 12 is fixedly provided with the pressure increasing block 120, the material of the pressure increasing block 120 is soft rubber, in order to realize dredging of the bottom air flow of the compactor 8, the pressure relief block 12 is movably arranged on the side wall of the top seat 7, therefore, in the extrusion process of the compactor 8, soil can be pressed and fastened by loosening, thereby greatly reducing the air flow conveying, further, in the taking-out process of the compactor 8, because the negative pressure factor is not easy to take out, the pressure relief block 12 is arranged, when the compactor 8 is separated, the air flow at the bottom of the compactor 8 is communicated with the outside through the deflection of the pressure relief block 12, meanwhile, in order, therefore, the rubber block is arranged at the top end of the pressure relief block 12, so that the friction factor of the compactor 8 can be clamped to the original position through the rubber block, the pressing work of the soil sample is not influenced through the soft rubber, and meanwhile, when the stress of the driving handle 11 is weakened, the pressure relief block 12 can be pushed out through the pressing of the pressure increasing block 120, so that the purpose of automatically exchanging air flow is realized.

Wherein, the one end of drive handle 11 is L shape, and the one end bending part of drive handle 11 all is equipped with the fillet, in order to restrict the deflection angle of drive handle 11 and move between 0-90 degrees, therefore through its one end of drive handle 11 and lie in the rotation part of drive handle 11 and be equipped with L shape terminal surface, therefore after its drive handle 11 pivoted angle is greater than ninety degrees, its apex angle can contact footstock 7 or pressure release piece 12, thereby prevent drive handle 11 to move once more, thereby make drive handle 11 can be quick ninety degrees lift its footstock 7, be convenient for the installation in zero angle.

Wherein, the shape of ejector pin 13 is L shape, and the bottom of pressure release piece 12 is equipped with the circular arc with drive handle 11 looks adaptation, in order to make ejector pin 13 can be independently follow drive handle 11 and carry out up-and-down reciprocating motion, therefore through being equipped with the fillet with drive handle 11 looks adaptation with the bottom of its ejector pin 13, therefore in drive handle 11 rotation and gliding in-process, its ejector pin 13 can carry out autonomic following.

Wherein, the shape of activity base 2 is C shape, and the arc groove of 4 looks adaptations of locking stick is seted up at one side middle part of activity base 2, does not incline or overturn at the base in order to guarantee the sample at the compact in-process bivalve mould 6, before carrying out the preparation of vibration triaxial sample, makes up activity base 2 and unable adjustment base 1 and fixes it with pin 3, constitutes a base recess that is bigger than bivalve mould 6 to control bivalve mould 6 and do not take place to remove at the system appearance in-process.

s1, assembling all the parts, connecting the locking rod 4 and the driving handle 11 to realize stable fixation of the movable base 2 and the three-petal mould 6, dividing the parts into three parts by mixing soil, and adding the three parts into the three-petal mould 6;

s2, pressing the soil in the three-segment mold 6 from the top seat 7 by selecting a proper compactor 8, and meanwhile, extruding the pressurizing block 120 through the side wall of the compactor 8 to realize pressure maintaining;

s3, the locking rod 4 is separated from the driving handle 11 and separated through the pressure relief block 12, so that the bottom of the compactor 8 is communicated with external air flow, the compactor 8 is ejected through the ejector rod 13, and meanwhile, the locking rod 4 is separated from the movable base 2;

and S4, pulling out the pin 3, so that the movable base 2 is separated from the fixed base 1 and is obliquely taken out from the fixed base 1 through the three-split mold 6.

The using method of the invention has the following working principle:

assembling state: firstly, arranging the three-petal mold 6 on the fixed base 1, secondly, fixing the three-petal mold 6 on the fixed base 1 through the movable base 2, enabling the movable base 2 to be difficult to move through the pin 3, secondly, sleeving the footstock 7 on the three-petal mold 6, and pulling upwards through the locking rod 4 on the fixed base 1, enabling the locking rod 4 to jack the movable base 2, meanwhile, pulling the driving handle 11, connecting the tightening rod 5 with the driving handle 11 through the thread of the tightening rod 5, and continuously screwing the tightening rod 5 into the driving handle 11, so that the driving handle 11 slides downwards on the movable groove on the footstock 7 until the tightening rod 5 cannot be fastened, at the moment, the top end of the mandril 13 is lower than the plane of the footstock 7, and meanwhile, the pressure relief block 12 jacks the pressure relief block 120 to the inner cavity of the footstock 7 due to the side wall of the driving handle 11;

and (3) compacting state: firstly, calculating the mass of a required soil sample and water according to the volume, the dry density and the water content of a sample, evenly mixing the soil sample and the water, evenly dividing the mixture into three parts, compacting the mixture in three times, pouring the soil into a three-petal mould 6 from a top seat 7, sleeving the top seat 7 through a compactor 8 after the mixture is filled, and downwards pressing the soil in the three-petal mould 6, meanwhile, in the process of pressing down the compactor 8, enabling a pressurizing block 120 to be in contact with the side wall of the compactor 8, further extruding the side wall of the pressurizing block 120 through the pressurizing block 120, enabling the compactor 8 to be stopped at the original position after the surface of the top seat 7 is attached to the compactor 8, and realizing the purpose of pressure maintaining, wherein at the moment, the compaction is finished;

the dismounting state: firstly, the tightening rod 5 reversely rotates to separate the driving handle 11 from the locking rod 4, the driving handle 11 is pushed to move upwards in a movable groove on the top seat 7 in the rotating process of the tightening rod 5, then when the tightening rod 5 is completely screwed out, the compactor 8 is jacked up through the jacking rod 13, and under the influence of the pressurizing block 120 squeezing the side wall of the compactor 8, the pressurizing block 120 pushes the pressure releasing block 12 to deflect outwards, so that the airflow at the bottom end of the compactor 8 is communicated with the external airflow, the bottom of the compactor 8 is prevented from generating negative pressure in the pulling process to make the compactor 8 difficult to take out, meanwhile, the driving handle 11 is lifted, the jacking rod 13 completely ejects the compactor 8 under the action of gravity, meanwhile, the top seat 7 is separated from the three-flap mold 6 through the lifting of the driving handle 11, and then the locking rod 4 deflects outwards, the locking rod 4 is separated from the movable base 2, the pin 3 is pulled out, the movable base 2 is taken out, the three-petal mold 6 is slowly taken out from the fixed base 1, and sample preparation is completed;

the blocking state of the compactor 8: when the compactor 8 is forced to be stuck, it is inserted into the lid-opening groove 9 through the lid opener 10 thereof, so that the deflector force generated by the lid opener 10 causes the compactor 8 to be ejected, thereby facilitating the removal of the compactor 8.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a high moisture content soil vibration triaxial test system appearance method and system appearance device, includes unable adjustment base (1), its characterized in that: a movable base (2) matched with the fixed base (1) is movably arranged on one side of the surface of the fixed base (1), and both sides of the fixed base (1) are respectively and movably provided with a locking bar (4), both sides of the top end of the fixed base (1) are respectively and movably connected with a pin (3), the movable base (2) is fixedly connected with the fixed base (1) through a pin (3), the inner wall of the movable base (2) is movably provided with three petals (6), a top seat (7) is movably arranged at the top end of the three-petal mould (6), driving handles (11) are movably arranged at the two sides of the top seat (7), a compactor (8) is movably arranged at the top end of the top seat (7), cover opening grooves (9) are formed in the two sides of the surface of the top seat (7), and two sides of the top seat (7) are provided with a cover opener (10) matched with the cover opening groove (9).

2. The high moisture content soil vibration triaxial test sample preparation device of claim 1, characterized in that: the utility model discloses a locking mechanism, including unable adjustment base (1), lateral wall and movable base (2), the top movable mounting of locking stick (4) on unable adjustment base (1) has locking stick (4), and the home range of locking stick (4) on unable adjustment base (1) is zero degree to eighty degree, the lateral wall and the movable base (2) swing joint of locking stick (4), and the top movable mounting of locking stick (4) has the stick (5) of tightening, movable groove has been seted up respectively to the both sides of footstock (7), and the inner wall slidable mounting in movable groove has drive handle (11), the screw with tightening stick (5) looks adaptation is seted up to the bottom of drive handle (11), the surface movable mounting of footstock (7) has ejector pin (13) that are arranged in groove (9) of uncapping, and the top swing joint of the one end of ejector pin (13) and drive handle (.

3. The high moisture content soil vibration triaxial test sample preparation device of claim 2, characterized in that: inner wall both sides movable mounting of footstock (7) has pressure relief piece (12), and in the inner chamber of footstock (7) was arranged in on the top of pressure relief piece (12), one side and drive handle (11) sliding connection of pressure relief piece (12), the top fixed mounting of pressure relief piece (12) has pressure increasing piece (120), and the material of pressure increasing piece (120) is soft rubber.

4. The high moisture content soil vibration triaxial test sample preparation device of claim 2, characterized in that: one end of the driving handle (11) is L-shaped, and the bent part of one end of the driving handle (11) is provided with a round corner.

5. The high moisture content soil vibration triaxial test sample preparation device of claim 2, characterized in that: the ejector rod (13) is L-shaped, and the bottom end of the pressure relief block (12) is provided with an arc matched with the driving handle (11).

6. The high moisture content soil vibration triaxial test sample preparation device of claim 2, characterized in that: the movable base (2) is C-shaped, and an arc groove matched with the locking rod (4) is formed in the middle of one side of the movable base (2).

7. The sample preparation method of the high-moisture-content soil vibration triaxial test sample preparation device according to any one of claims 1 to 6, characterized by comprising the following steps:

s1, assembling all the components, connecting the locking rod (4) and the driving handle (11) to realize stable fixation of the movable base (2) and the three-piece mold (6), dividing the parts into three parts by mixing soil, and adding the three parts into the three-piece mold (6);

s2, pressing the soil in the three-segment mold (6) from the top seat (7) into the three-segment mold (6) by selecting a proper compactor (8), and meanwhile, extruding the pressurizing block (120) through the side wall of the compactor (8) to realize pressure maintaining;

s3, separating the locking rod (4) by the driving handle (11) and separating the locking rod from the pressing block (12), so that the bottom of the compactor (8) is communicated with external air flow, ejecting the compactor (8) by the ejector rod (13), and separating the locking rod (4) from the movable base (2);

and S4, pulling out the pin (3), so that the movable base (2) is separated from the fixed base (1), and the movable base is obliquely taken out from the fixed base (1) through the three-petal mold (6).