CN111426535A - A device for preparing hollow cylindrical samples by sand rain method with automatic control of drop distance - Google Patents

Abstract

The invention discloses a sand rain method hollow cylindrical sample preparation device with automatic drop distance control, comprising: a frame assembly; a sand storage assembly, the sand storage assembly is used to store the sand particles required by the sample, The assembly has a sand leakage port; a suspension assembly, the suspension assembly is arranged on the frame assembly and connected with the sand storage assembly for hanging the sand storage assembly on the frame assembly; a sample mold, The sample mold is communicated with the sand leakage port, and the sample mold is used for receiving the sand particles leaked from the sand leakage port; an adjustment member, the adjustment member is connected with the sand storage assembly, and the adjustment member In cooperation with the suspension assembly, the height of the sand storage assembly is adjusted in real time, so that the drop distance of the sand leakage at the sand leakage port is constant. According to the sand-rain method hollow cylindrical sample preparation device for automatically controlling the drop distance according to the embodiment of the present invention, the prepared samples have good uniformity, high accuracy and good repeatability.

Description

A device for preparing hollow cylindrical samples by sand rain method with automatic control of drop distance

technical field

The invention relates to the technical field of geotechnical testing instruments, in particular to a sand-rain method hollow cylindrical sample preparation device capable of automatically controlling drop distance.

Background technique

The hollow cylinder torsional shear test can control various stress paths, and can realize a wide range of stress states, and has been widely used. However, at present, there is no unified method for preparing hollow cylindrical samples at home and abroad. Both the sand rain method and the vibrating method are used. The mechanical response of the sample has a great influence. Even under the same loading conditions, the initial state of the sample is slightly different, and the test results will be very different. This error is often unacceptable, especially for dynamic loading studies on soils. when liquefied. At present, the anisotropy of soil has become a hot topic in academic research. When conducting experiments, whether the deposition direction of soil is uniform is the key factor for the quality of the test results.

The sand rain method is one of the important methods for the preparation of samples for indoor geotechnical tests. In theory, it can prepare soil samples with horizontal deposition. However, the sand rain method widely used at home and abroad has many shortcomings: for example, the artificial method of lifting the sand cylinder easily ignores the influence of the sand surface uplift, resulting in uneven samples; The size of the sand outlet cannot be adjusted. For small-sized sand particles, when the sand outlet flow is too large, the sand particles will collide with each other during the falling process, which will affect the deposition effect. The sand surface of the sample does not rise synchronously, the sand surface below the sand falling mouth will be higher than the surrounding area, the sand surface is partially inclined, the sand falling here is not in a horizontal deposition state, and the inclination is too large, which may even cause falling sand particles. Rolling occurs, which destroys the horizontal deposition state of the soil sample; the soil material has no side and no restraint during the falling process, causing the soil material to spill out of the sample mold; in addition, the sample preparation process needs to continuously add soil samples to the funnel, which is cumbersome to operate. This results in uneven sanding, poor repeatability of prepared samples, and room for improvement.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present invention is to provide a sand-rain method hollow cylindrical sample preparation device with automatic drop distance control, so that the sample preparation is simple, the prepared samples are uniform, and the repeatability is high.

According to an embodiment of the present invention, the sand-rain method hollow cylindrical sample preparation device with automatic control of falling distance includes: a frame assembly; The assembly has a sand leakage port; a suspension assembly, the suspension assembly is arranged on the frame assembly and connected with the sand storage assembly for hanging the sand storage assembly on the frame assembly; a sample mold, The sample mold is communicated with the sand leakage port, and the sample mold is used to receive the sand particles leaked from the sand leakage port; an adjustment member, the adjustment member is connected with the sand storage assembly, and the adjustment member In cooperation with the suspension assembly, the height of the sand storage assembly is adjusted in real time, so that the drop distance of the sand leakage at the sand leakage port is constant.

According to the sand rain method hollow cylindrical sample preparation device for automatically controlling the falling distance according to the embodiment of the present invention, by setting the adjusting member connected to the sand storage assembly, the adjusting member can be adjusted in real time when sand leaks from the sand leakage port of the sand storage assembly The height of the sand storage component keeps the distance between the sand leakage port and the upper surface of the sand grains unchanged, so as to avoid the great influence on the test results caused by the increase of the soil sample surface as the sample preparation progresses, and the uniformity of the prepared samples is good. High accuracy and good repeatability.

According to an embodiment of the present invention, the sand-rain method hollow cylindrical sample preparation device for automatically controlling the drop distance, the adjusting member includes: an elastic member, the elastic member is arranged on the frame assembly, and one end of the elastic member is connected to the The suspension assembly is connected, and the other end is connected with the sand storage assembly, and the elastic member adjusts the height of the sand storage assembly according to the sand leaked from the sand leakage port.

Specifically, the cross-sectional area of the sample mold is s, the dry bulk density of the sand grains is γ, and the stiffness of the elastic member is k, where k=γ×s.

According to an embodiment of the present invention, the sand-rain method hollow cylinder sample preparation device with automatic control of drop distance further includes: a drop-out component, the drop-out component is provided between the sand storage component and the sample mold and includes a drop-out component. A sand distributor, which is used for distributing the sand particles of the sand storage component to the sample mold.

Further, the sand separator includes: a sand separator cone, which is arranged directly below the sand leakage opening; a sand bundle cover, which is arranged on the outside of the sand separator cone, and A sand outlet corresponding to the cross-sectional shape of the sample mold is defined between the lower part of the sand distribution cone and the lower part of the sand bundle cover.

Optionally, the sand separator further includes a sand receiving pipe, and the sand receiving pipe is arranged above the sand separating cone, and the sand storage assembly further includes a sand leakage pipe, and the sand leakage pipe is arranged on the sand leakage pipe. Below the sand leakage port, and at least a part of the sand leakage pipe is inserted into the sand receiving pipe.

Optionally, a sand collecting nozzle is provided in the sand receiving pipe, and the center line of the sand collecting nozzle coincides with the center line of the sand dividing cone.

Optionally, the sand collecting nozzle includes a plurality of the sand collecting nozzles, and the plurality of the sand collecting nozzles are arranged at intervals along the extending direction of the sand receiving pipe.

Optionally, the angle between the inner wall surface of the sand dividing cone and the horizontal plane is α, and α is greater than the natural angle of repose of the sand; The included angle between the inner wall surface and the horizontal plane of the sand is α, and α is greater than the natural angle of repose of the sand; and/or, the sand collecting nozzle forms an inverted cone, and the included angle between the inner wall surface and the horizontal plane of the sand collecting nozzle is α, α is greater than the natural angle of repose of the sand.

Optionally, the shakeout assembly further includes: a shakeout cylinder, the shakeout cylinder is arranged between the sand separator and the sample mold, and the shakeout cylinder defines a cross-sectional shape that is the same as that of the sample mold. The dropout cavity corresponding to the sample mold.

Optionally, the shakeout cylinder includes a plurality of shakeout cylinders, and the multiple shakeout cylinders are matched and connected in sequence.

According to an embodiment of the present invention, the sand-rain method hollow cylindrical sample preparation device with automatic control of drop distance further includes: a rotating assembly, which is arranged on the frame assembly and connected to the sand storage assembly, and the rotating assembly for driving the sand storage assembly to rotate.

Specifically, the rotating assembly includes: a casing, which is connected to the adjusting member; a central shaft, which is connected to the sand storage assembly, and is suitable for rotating in the casing. , so as to drive the sand storage assembly to rotate.

Optionally, the rotating component is a rotating spring.

According to the sand-rain method hollow cylindrical sample preparation device for automatically controlling the drop distance according to the embodiment of the present invention, the sand storage assembly includes: a cylindrical section and a funnel section, the cylindrical section is provided at the upper end of the funnel section, and the funnel The sand leakage port is formed at the lower end of the segment, wherein an opening degree control switch is provided at the sand leakage port.

Optionally, the included angle between the inner wall surface of the funnel section and the horizontal plane is α, where α is greater than the natural angle of repose of the sand grains.

According to an embodiment of the present invention, the device for preparing a hollow cylindrical sample by the sand rain method with automatic drop distance control, the suspension assembly includes a suspension wire, and the suspension wire is connected to the sand storage assembly for connecting the sand storage assembly. The assembly is hung on the frame assembly; the wire reel is arranged on the frame assembly, and the wire reel is connected with the suspension wire to drive the suspension wire to extend and retract.

According to the device for preparing a hollow cylindrical sample by the sand rain method with automatic drop distance control, the sample mold includes an outer mold cylinder and an inner mold cylinder, and the outer mold cylinder is sleeved on the outside of the inner mold cylinder, And the accommodating cavity is defined between the outer mold cylinder and the inner mold cylinder.

Optionally, the accommodating cavity is formed in an annular shape, and the sand leakage port is located on the center line of the accommodating cavity.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

1 is a schematic structural diagram of a sample preparation device according to an embodiment of the present invention;

2 is a schematic structural diagram of a sand storage assembly according to an embodiment of the present invention;

3 is a schematic structural diagram of a sand separator according to an embodiment of the present invention;

4 is a schematic structural diagram of a shakeout drum according to an embodiment of the present invention;

5 is a schematic structural diagram of a sample mold according to an embodiment of the present invention;

Reference number:

Sample preparation device 100,

Frame assembly 10, bracket 11, base 12,

Suspension assembly 20, suspension wire 21, reel 22, pulley block 23,

Sand storage assembly 30, sand leakage port 301, cylindrical section 31, funnel section 32, opening control switch 33, sand leakage pipe 34,

Adjustment member 40, rotating assembly 50,

Shafting assembly 60, sand distributor 61, sand receiving pipe 611, sand collecting nozzle 612, sand distribution cone 613, sand beam hood 614, sand outlet 615, shakeout cylinder 62, shakeout chamber 6201, outer cylinder 621, inner cylinder 622,

Sample mold 70 , accommodating cavity 701 , mold outer cylinder 71 , mold inner cylinder 72 , and mold seat 73 .

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, features delimited with "first", "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The following describes an apparatus 100 for preparing a hollow cylindrical sample by the sand-rain method with automatic drop distance control according to an embodiment of the present invention with reference to FIGS. 1 to 5 .

As shown in FIGS. 1-5 , the sand-rain method hollow cylindrical sample preparation device 100 for automatically controlling the drop distance according to an embodiment of the present invention includes: a frame assembly 10 , a sand storage assembly 30 , a suspension assembly 20 and a sample mold 70 , the sand storage assembly 30 is disposed on the frame assembly 10 , the sand storage assembly 30 is used for storing the sand grains required by the sample, and the sand storage assembly 30 has a sand leakage port 301 . The suspension assembly 20 is arranged on the frame assembly 10, and the suspension assembly 20 is connected with the sand storage assembly 30. The suspension assembly 20 is used to hang the sand storage assembly 30 on the frame assembly 10, and the sample mold 70 communicates with the sand leakage port 301. , the sample mold 70 receives the sand leaked from the sand leakage port 301 .

The sample preparation device 100 further includes an adjustment member 40 , which is connected with the sand storage assembly 30 , and the adjustment member 40 cooperates with the suspension assembly 20 to adjust the amount of sand leaked from the sand leakage port 301 or according to the change of the weight of the sand storage assembly 30 . The height of the sand storage assembly 30 is adjusted in real time, so that the drop distance of the sand leakage at the sand leakage port 301 remains unchanged. Wherein, the adjusting member 40 can be installed on the suspension assembly 20, and the adjustment of the falling distance of the sand particles can be realized by the adjustment member being matched with the suspension assembly 20.

According to the sand-rain method hollow cylindrical sample preparation device 100 for automatically controlling the drop distance according to the embodiment of the present invention, by setting the adjusting member 40 connected with the sand storage assembly 30, when the sand leakage port 301 of the sand storage assembly 30 leaks sand, The adjustment member 40 can adjust the height of the sand storage assembly 30 in real time, so that the distance between the sand leakage port 301 and the upper surface of the sand grain remains unchanged, so as to avoid the great influence on the test results due to the progress of the sample preparation and the rise of the soil sample surface. Thus, the prepared samples have good uniformity and high accuracy.

According to an embodiment of the present invention, the adjustment member 40 includes an electronic scale, which is installed on the upper part of the sand storage assembly 30. The electronic scale can measure the quality change of the sand inside the sand storage assembly 30 in real time, and then use a computer-controlled suspension assembly. 20 Lift the sand storage assembly 30, thereby ensuring that the distance between the sand leakage port 301 and the upper surface of the sand grains in the sample mold 70 is always kept constant.

As shown in FIG. 1, according to an embodiment of the present invention, the adjusting member 40 is an elastic member, the elastic member is arranged on the frame assembly 10, one end of the elastic member is connected with the suspension assembly 20, and the other end is connected with the sand storage assembly 30, The elastic member can adjust the height of the sand storage assembly 30 according to the sand leaked from the sand leakage port 301, and the elastic member can be a tension spring with a fixed rigidity.

Specifically, as the sand in the sand storage assembly 30 decreases, the elastic member will gradually shorten, and the height of the sand leakage port 301 will change accordingly. Assuming that the height of the sample is ΔL, then at the end of the sand leakage, the elastic member should be shortened by ΔL. L, and this shortening changes linearly according to the reduction of the sand mass in the sand storage assembly 30, wherein the cross-sectional area of the sample mold 70 is s, the dry bulk density of the sand grains is γ, and the weight of the sample is γ·s ·△L, the stiffness of the elastic part is k, then k·△L=γ·s·△L, that is, k=γ×s. It should be noted that different relative densities correspond to elastic parts with different stiffnesses, and the corresponding elastic parts should be selected according to the specified relative densities during the test.

As shown in FIG. 1 , according to an embodiment of the present invention, the sample preparation device 100 further includes: a shakeout assembly 60 , the shakeout assembly 60 is arranged between the sand storage assembly 30 and the sample mold 70 , and the shakeout assembly 60 includes The sand separator 61 is used to distribute the sand particles of the sand storage assembly 30 to the sample mold 70. By setting the sand separator 61, the sand particles in the sand storage assembly 30 can be uniformly dispersed into the sample mold 70. .

As shown in FIG. 3 , in some examples, the sand separator 61 includes: a sand separation cone 613 and a sand bundle hood 614 , the sand separator cone 613 is provided just below the sand leakage port 301 , and the sand bundle hood 614 is provided on the sand separator 613 The outer side of the sand distribution cone 613 and the lower part of the sand bundle cover 614 define a sand outlet 615. The sand outlet 615 corresponds to the cross-sectional shape of the sample mold 70. For example, the sample mold 70 forms a ring shape, and the sand outlet Port 615 forms an annular sand outlet.

Specifically, the sand dividing cone 613 is a conical surface with its apex facing upward, and its apex and the center of the sand leakage port 301 are on the same vertical line. The sand particles impact on the sand dividing cone 613 and will be evenly dispersed; The lower part of 614 is a part of a conical surface, which is concentric with the sand distribution cone 613. The sand bundle hood 614 is used to constrain the sand particles dispersed by the sand distribution cone 613. The sand particles bounce back and forth between the sand distribution cone 613 and the sand bundle hood 614, and finally are evenly distributed into the sample molds 70 . Among them, the sand distribution cone 613 and the sand bundle cover 614 should be connected, so that the two are integrated, but the projection of the connection on the horizontal plane must be small to reduce the impact on the falling sand.

As shown in FIG. 3 , in some examples, the sand distributor 61 further includes a sand receiving pipe 611 , and the sand receiving pipe 611 is arranged above the sand distributing cone 613 , and the sand storage assembly 30 further includes a sand leakage pipe 34 , and the sand leakage pipe 34 It is arranged below the sand leaking port 301, and at least a part of the sand leaking pipe 34 is inserted into the sand receiving pipe 611, that is, there is an overlapping part between the sand leaking pipe 34 and the sand receiving pipe 611, and the length of this part should be longer than the test pipe 611. The height of the sand grains that can be accommodated in the sample mold 70 is determined to ensure that the sand leaking pipe 34 and the sand receiving pipe 611 still have an overlapping length at the end of sand spreading, so that the sand will not be spilled outside the sand receiving pipe 611 .

As shown in FIG. 3 , in some examples, a sand collecting nozzle 612 is provided in the sand receiving pipe 611 , the center line of the sand collecting nozzle 612 coincides with the center line of the sand distribution cone 613 , the sand collecting nozzle 612 forms an inverted cone, and the large mouth of the sand collecting nozzle 612 is formed. The center of the small mouth of the sand collecting nozzle 612 is on the same vertical line as the apex of the sand dividing cone 613. The sand collecting nozzle 612 can collect the sand bundles caught by the sand receiving pipe 611 into a uniform and continuous sand flow. The sand leaked from the sand leaking pipe 34 falls along the central axis of the sand receiving pipe 611, and is then collected by the sand collecting nozzle 612. The sand particles are facing the apex of the sand dividing cone 613, and the sand particles are evenly distributed along the circumference.

In some examples, the sand collecting nozzles 612 include multiple, and the multiple sand collecting nozzles 612 are arranged at intervals along the extension direction of the sand receiving pipe 611. The distance between the two sand collecting nozzles 612 may be the same or different. By providing multiple sand collecting nozzles 612, so that the bundled sand flow directly rushes to the apex of the sand dividing cone 613, thereby facilitating uniform dispersion.

In some examples, the included angle between the inner wall surface of the sand dividing cone 613 and the horizontal plane is α, and α is greater than the natural angle of repose of the sand grains, thereby preventing the sand grains from remaining in the sand dividing cone 613 and ensuring that the sand grains can be Automatic sliding to ensure the accuracy and reliability of the test.

In some examples, the sand bunching cover 614 forms an inverted cone, and the included angle between the inner wall surface of the sand bunching cover 614 and the horizontal plane is α, and α is greater than the natural angle of repose of the sand grains, thereby preventing the sand grains from remaining in the sand bunching cover 614 It ensures that the sand particles can automatically slide down during the sample preparation process to ensure the accuracy and reliability of the test.

In some examples, the sand collecting nozzle 612 forms an inverted cone shape, and the angle between the inner wall surface of the sand collecting nozzle 612 and the horizontal plane is α, and α is greater than the natural angle of repose of the sand particles, thereby preventing the sand particles from remaining in the sand collecting nozzle 612 and ensuring that During the sample preparation process, the sand particles can slide down automatically to ensure the accuracy and reliability of the test.

As shown in FIG. 4 , in some examples, the shakeout assembly 60 further includes: a shakeout drum 62 disposed between the sand separator 61 and the sample mold 70 , and the shakeout drum 62 defines a cross-section The shape of the shakeout cavity 6201 corresponding to the sample mold 70 and the shakeout cylinder 62 can restrain the sand grains, so that the sand grains fall along the shakeout cavity 6201 . Specifically, the annular shakeout cylinder 62 includes an inner cylinder 622 and an outer cylinder 621. A circular cylindrical shakeout chamber 6201 is formed between the inner cylinder 622 and the outer cylinder 621. The inner cylinder 622 and the outer cylinder 621 are located in the shakeout chamber. There are no connections in the 6201 to ensure that the sand particles are not blocked in the process of falling.

The shakeout cylinder 62 is arranged at the lower part of the sand separator 61, the lower part of the sand separator cone 613 corresponds to the inner cylinder of the shakeout cylinder 62, the lower part of the sand bundle cover 614 corresponds to the outer cylinder of the shakeout cylinder 62, and overlaps slightly to ensure the fixation , no misalignment occurs.

In some examples, the shakeout cylinders 62 include multiple ones, and the multiple shakeout cylinders 62 are matched and connected in sequence. That is, the shakeout cylinders 62 can be segmented, and the length of each segment is determined according to actual needs, and different lengths can be set. different lengths and distances can be assembled. There are various connection forms between the segments, such as threaded connection, plug-in connection or other methods, which are not limited here.

As shown in FIG. 1 , according to an embodiment of the present invention, the sample preparation device 100 further includes: a rotating assembly 50 , the rotating assembly 50 is arranged on the frame assembly 10 and connected to the sand storage assembly 30 , and the rotating assembly 50 is used for driving the sand storage assembly The assembly 30 rotates, and the sand storage assembly 30 is driven to rotate by the rotating assembly 50 , so that the sand leaking port 301 spreads sand in a rotating manner, so that the falling sand flow can be evenly distributed into the sample mold 70 .

In some examples, the rotating assembly 50 includes a casing and a central shaft, the casing is connected with the adjusting member 40 , the central shaft is connected with the sand storage assembly 30 , and the central shaft is adapted to rotate in the casing to drive the sand storage assembly 30 to rotate.

In some specific examples, the rotating assembly 50 may be a rotating spring, the upper part of the sand storage assembly 30 is connected to the rotating spring, and the sand leakage pipe 34 at the lower part of the sand storage assembly 30 extends into the sand receiving pipe 611 of the sand separator 61 . After the rotating spring is fully wound, the central shaft rotates when released, which will drive the lower sand storage assembly 30 to rotate, and the sand leakage pipe 34 will spread the sand in a rotating manner, so that the sand separator 61 can fall more evenly. The grains of sand are evenly distributed into the sample mold 70.

Ideally, the sand flow leaked from the sand leaking pipe 34 falls along the central axis of the sand receiving pipe 611, and is then collected by the sand collecting nozzle 612. However, in actual operation, the sand spilled from the sand leakage pipe 34 does not necessarily fall along the central axis of the sand receiving pipe 611, and there will be a certain deviation. At this time, the sand flow collected by the multiple sand collecting nozzles 612 is relatively concentrated To the vicinity of the central axis, but there are still deviations. In practice, it is found that the sand surface of the produced sample is not raised synchronously, and there will be a slight situation where one side is high and the other is low, and the horizontal deposition state is not ideal. At this time, by setting the rotating assembly 50, the sand leakage pipe 34 is rotated to spread sand, even if the sand flow is eccentric, the sand flow is rotatably sprayed, and this eccentricity will be averaged out in the whole process of sand spreading. Practice has proved that the sand surface produced by rotary sand spraying is raised synchronously, which achieves the purpose of horizontal deposition, and the effect is ideal.

As shown in FIG. 2 , according to an embodiment of the present invention, the sand storage assembly 30 includes: a cylindrical section 31 and a funnel section 32 , the cylindrical section 31 is provided at the upper end of the funnel section 32 , and a sand leakage port 301 is formed at the lower end of the funnel section 32 , wherein, the sand leakage port 301 is provided with an opening degree control switch 33, and the opening degree control switch 33 can adjust the flow rate of the sand leakage according to the size of the sand particle size. For sand with small particle size, reduce the flow rate of sand production to avoid collision of sand particles in the process of falling, which will affect the deposition effect, and ensure that the deposition effect is basically the same as that of typical horizontal deposition.

Among them, the volume contained in the cylindrical section 31 and the funnel section 32 should be able to hold all the sand volume required for one sample. The sand leaking pipe 34 is a slender hollow circular pipe, the sand leaks from the pipe into the sand receiving pipe 611, the lower part of the funnel section 32 also has a sand leaking pipe 34, and the opening control switch 33 is located on the upper part of the sand leaking pipe 34. The flow rate of sand leakage can be adjusted according to the size of the sand particle size.

In some examples, the included angle between the inner wall surface of the funnel section 32 and the horizontal plane is α, where α is greater than the natural angle of repose of the sand grains, thereby preventing the sand grains from remaining in the funnel section 32 and ensuring that the sand grains can be Automatic sliding to ensure the accuracy and reliability of the test.

As shown in FIG. 1 , according to an embodiment of the present invention, the suspension assembly 20 includes: a suspension wire 21 and a reel 22 . The suspension wire 21 is connected to the sand storage assembly 30 for hanging the sand storage assembly 30 on the frame On the assembly 10, the reel 22 is arranged on the frame assembly 10, and the reel 22 is connected with the suspension wire 21 to drive the suspension wire 21 to extend and retract. When the suspension wire 21 is extended, the sand storage assembly 30 can move downward, reducing the sand spraying effect. When the suspension wire 21 is shortened, the sand storage assembly 30 can move upward to increase the drop distance of the sand sprinkler, so that the basic drop distance of the sand sprinkler can be adjusted through the movable reel 22, and the operation is convenient.

Further, the suspension assembly 20 further includes a pulley block 23, the pulley block 23 is fixed on the frame assembly 10, and the suspension wire 21 is arranged on the pulley assembly 23, so that the suspension wire 21 can slide and extend, reduce friction, and improve the stability of the structure.

As shown in FIG. 5 , according to an embodiment of the present invention, the sample mold 70 includes an outer mold cylinder 71 and an inner mold cylinder 72 , the outer mold cylinder 71 is sleeved on the outside of the inner mold cylinder 72 , and the outer mold cylinder 71 and the inner mold cylinder 72 are sleeved. A cavity 701 is defined between the cylinders 72, wherein the shakeout cylinder 62 forms a corresponding ring shape, the outer cylinder 621 of the shakeout cylinder 62 is placed on the outer cylinder 71 of the mold, and the inner cylinder 622 of the shakeout cylinder 62 is placed on the mold The inner cylinder 72 is slightly overlapped to ensure a fixed position without misalignment.

In some examples, the accommodating cavity 701 forms an annular shape, and the sand leakage port 301 is located on the center line of the accommodating cavity 701 . The central axis should be on the same vertical line, so that the falling sand flow can be evenly distributed into the accommodating cavity 701, thereby ensuring the accuracy of the test.

A specific embodiment of the sand-rain method hollow cylindrical sample preparation device 100 for automatically controlling the drop distance according to the present invention will be described below with reference to FIGS. 1 to 5 .

The sample preparation device 100 includes a frame assembly 10, a suspension assembly 20, an adjustment member 40, a rotation assembly 50, a sand storage assembly 30, a shakeout assembly 60 and a sample mold 70. The sample mold 70 includes a mold outer cylinder 71, an inner mold The barrel 72 and the mold seat 73 .

The frame assembly 10 includes a bracket 11 and a base 12. The base 12 is located at the lower part of the whole device, which plays a stabilizing role and provides a platform for sample preparation. The bracket 11 is installed on the base 12, and the suspension assembly 20 is installed on the bracket 11. The assembly 20 includes: a pulley block 23 , a suspension wire 21 , and a reel 22 . One end of the suspension wire 21 is wound on the reel 22, the adjusting member 40 is an elastic member, and the elastic member is installed on the other end of the suspension wire 21; the rotating component 50 is a rotating spring, which is connected below the elastic member.

The sand storage assembly 30 includes: a cylindrical section 31, a funnel section 32, an opening control switch 33, and a sand leakage pipe 34. The funnel section 32 connects the cylindrical section 31 and the sand leakage pipe 34. The volume contained in the cylindrical section 31 and the funnel section 32 should be The total amount of sand required to hold a sample. The opening control switch 33 is located at the upper part of the sand leakage pipe 34, which can adjust the flow rate of the sand leakage according to the size of the sand grains.

The shakeout assembly 60 includes a sand separator 61 and a shakeout cylinder 62. Both the sand separator 61 and the shakeout cylinder 62 are annular. The annular sand separator 61 includes: a sand receiving pipe 611, a sand collecting nozzle 612, a sand separation cone 613, a beam The sand hood 614 and the sand receiving pipe 611 are located on the upper part of the sand bundle hood 614 and the sand dividing cone 613 . The sand collecting nozzles 612 are arranged inside the sand receiving pipe 611, and the number of them can be multiple, and one is arranged at a certain distance. The sand leakage pipe 34 is a slender hollow circular pipe, and there is overlap between the sand leakage pipe 34 and the sand receiving pipe 611. , the sand leaks from the pipe into the sand receiving pipe 611. The sand distribution cone 613 is a conical surface with its apex facing upward, and its vertex and the center of the small hole of the sand collecting nozzle 612 are on the same vertical line. Open; the lower part of the sand beam cover 614 is a part of a conical surface, and the sand distribution cone 613 is concentric.

The annular shakeout cylinder 62 includes an outer cylinder 621 and an inner cylinder 622 . The lower part of the sand dividing cone 613 corresponds to the inner cylinder 622 of the annular shakeout cylinder 62 ; The lower part of the annular shakeout drum 62 is the sample mold 70 .

The angle between the inner wall surface of the sand dividing cone 613 and the horizontal plane is α, the sand bunching cover 614 forms an inverted cone, the included angle between the inner wall surface of the sand bunching cover 614 and the horizontal plane is α, and the sand collecting nozzle 612 forms an inverted cone , the included angle between the inner wall surface of the sand collecting nozzle 612 and the horizontal plane is α, the included angle between the inner wall surface of the funnel section 32 of the sand storage assembly 30 and the horizontal plane is α, and α is greater than the natural angle of repose of the sand, thereby avoiding No grit remains in the sample preparation unit.

First, the relationship between different drop distances and the relative density of the sample should be calibrated, and then according to the relative density required by the test, the corresponding drop distance and the corresponding stiffness of the elastic piece should be selected, where the stiffness of the elastic piece is k=γ×s. After the drop distance is determined, all the sand required for a sample is weighed and poured into the sand storage assembly 30 at one time, and the suspension assembly 20 is adjusted to achieve the specified drop distance. Then, according to the drop distance, an annular shakeout drum 62 with matching lengths is assembled, placed above the sample mold 70, and then an annular sand separator 61 is placed above the annular shakeout drum 62, and the sand leakage pipe 34 of the sand storage assembly 30 is placed Extend into the sand receiving pipe 611 of the annular sand separator 61 to ensure that the overlapping length of the two is greater than the height of the sample. During operation, it is necessary to ensure that the central axes of the sample mold 70, the annular shakeout drum 62, the annular sand separator 61 and the sand storage assembly 30 are on the same vertical line.

Next, turn the mainspring fully, and adjust the opening control switch 33 according to the size of the sample sand grains, so that the falling sand grains form a uniform and continuous sand flow. In the middle, there should be less collision between the sand particles to ensure the state of free fall. During the whole process, the sand storage assembly 30 continues to rotate, the rotating sand flow sprinkled from the sand leakage pipe 34 is evenly distributed into the ring, and the sand particles continuously fall until the deposition of the sample is completed. During the sand spraying process, the sand surface of the sample gradually rises, and the elastic parts gradually shrink to ensure a constant drop distance. During the deposition of the sample, the sand surface is raised synchronously, and the sand particles will not move after falling to the sand surface, which ensures the effect of horizontal deposition.

According to the embodiment of the present invention, in the process of sample preparation, the device will automatically adjust the height of the sand leakage port according to the height of the sand surface in the sample, so as to keep the drop distance constant during the whole process of sample preparation; Form a continuous and stable sand flow, reduce the impact of mutual impact during the sand falling process, and ensure free fall; during the sand spraying process, the sand particles are evenly sprinkled into the annular sample range, and the sand surface of the sample rises synchronously, and the sand particles are not scattered after being sprinkled. Rolling occurs again to ensure the state of horizontal deposition of the soil sample; the sand particles will not fall outside the mold during the sanding process, and the required amount of sand for the entire sample can be added at one time. The operation is simple and the uniformity of the sample is guaranteed. The sample has good uniformity, high accuracy and good repeatability.

Other structures and operations of the sand-rain method hollow cylindrical sample preparation device 100 according to the embodiment of the present invention are known to those of ordinary skill in the art, and will not be described in detail here.

In the description of the present invention, unless otherwise expressly stated and defined, a first feature "above" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features The two features are not in direct contact but through another feature between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, material, or characteristic described by an example or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

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

Claims (19)

1. a sand-rain method hollow cylinder sample preparation device of automatic control drop distance, is characterized in that, comprises: frame components; a sand storage component, the sand storage component is used for storing the sand grains required by the sample, and the sand storage component has a sand leakage port; a suspension assembly, the suspension assembly is arranged on the frame assembly and connected with the sand storage assembly for hanging the sand storage assembly on the frame assembly; a sample mold, the sample mold is communicated with the sand leakage port, and the sample mold is used for receiving the sand particles leaked from the sand leakage port; an adjustment member, the adjustment member is connected with the sand storage assembly, and the adjustment member cooperates with the suspension assembly to adjust the height of the sand storage assembly in real time, so as to make the drop distance of the sand leakage at the sand leakage port constant. 2 . The sand-rain method hollow cylindrical sample preparation device according to claim 1 , wherein the adjusting member is an elastic member, and the elastic member is provided on the frame assembly, and the One end of the elastic member is connected to the suspension assembly, and the other end is connected to the sand storage assembly, and the elastic member adjusts the height of the sand storage assembly according to the sand particles leaked from the sand leakage port. 3. The sand-rain method hollow cylinder sample preparation device of automatic control drop distance according to claim 2 is characterized in that, the cross-sectional area of the sample mold is s, and the dry bulk density of the sand is γ, so The stiffness of the elastic member is k, where k=γ×s. 4. The sand-rain method hollow cylindrical sample preparation device with automatic control of drop distance according to claim 1, characterized in that, further comprising: a shake-out component, wherein the shake-out component is provided in the sand-storage component and the A sand distributor is included between the sample molds, and the sand distributor is used to distribute the sand particles of the sand storage assembly to the sample molds. 5. The sand-rain method hollow cylinder sample preparation device of automatic control drop distance according to claim 4, is characterized in that, described sand separator comprises: a sand dividing cone, the sand dividing cone is arranged just below the sand leaking port; Sand bunching hood, the sand bunching hood is arranged on the outside of the sand dividing cone, and between the lower part of the sand dividing cone and the lower part of the sand bunching hood is defined a shape corresponding to the cross-sectional shape of the sample mold Sand outlet. 6. The sand-rain method hollow cylindrical sample preparation device of automatic control drop distance according to claim 5, characterized in that, the sand separator further comprises a sand receiving pipe, and the sand receiving pipe is provided in the sand separating Above the cone, the sand storage assembly further includes a sand leakage pipe, the sand leakage pipe is arranged below the sand leakage port, and at least a part of the sand leakage pipe is inserted into the sand receiving pipe. 7. The sand-rain method hollow cylindrical sample preparation device with automatic control of falling distance according to claim 6, characterized in that, a sand collecting nozzle is provided in the sand receiving pipe, and the center line of the sand collecting nozzle and the sand separation nozzle are provided. The centerlines of the cones coincide. 8 . The sand-rain method hollow cylindrical sample preparation device with automatic drop distance control according to claim 7 , wherein the sand collecting nozzles comprise a plurality of sand collecting nozzles, and the plurality of sand collecting nozzles extend along the sand receiving pipe. 9 . Orientation spaced. 9. The sand rain method hollow cylinder sample preparation device of automatic control drop distance according to claim 7, is characterized in that, the angle between the inner wall surface of described sand dividing cone and the horizontal plane is α, and α is greater than this sand grain natural angle of repose; and/or, The sand bunching hood forms an inverted cone, and the included angle between the inner wall surface of the sand bunching hood and the horizontal plane is α, and α is greater than the natural angle of repose of the sand; and/or, The sand collecting nozzle forms an inverted cone, and the included angle between the inner wall surface of the sand collecting nozzle and the horizontal plane is α, and α is greater than the natural angle of repose of the sand grains. 10. The sand-rain method hollow cylindrical sample preparation device with automatic control of drop distance according to claim 4, characterized in that, the shake-out assembly further comprises: a shake-out cylinder, the shake-out cylinder is provided in the sub-section. between the sander and the sample mold, and the shakeout cylinder defines a shakeout cavity with a cross-sectional shape corresponding to the sample mold. 11 . The sand-rain method hollow cylindrical sample preparation device with automatic control of drop distance according to claim 10 , wherein the shake-out cylinder comprises a plurality of shake-out cylinders, and the multiple shake-out cylinders are matched and connected in sequence. 12 . 12. The sand-rain method hollow cylinder sample preparation device for automatically controlling the drop distance according to any one of claims 1-11, characterized in that, further comprising: a rotating assembly, the rotating assembly is provided on the frame assembly and is connected with the sand storage assembly, and the rotation assembly is used to drive the sand storage assembly to rotate. 13. The sand-rain method hollow cylinder sample preparation device for automatically controlling drop distance according to claim 12, wherein the rotating assembly comprises: a casing, the casing is connected with the adjusting member; A central shaft, the central shaft is connected with the sand storage assembly, and the central shaft is adapted to rotate in the casing to drive the sand storage assembly to rotate. 14 . The sand-rain method hollow cylinder sample preparation device with automatic drop distance control according to claim 13 , wherein the rotating component is a rotating spring. 15 . 15 . The sand-rain method hollow cylindrical sample preparation device according to any one of claims 1 to 11, wherein the sand storage component comprises: a cylindrical section and a funnel section, the cylindrical The section is arranged at the upper end of the funnel section, and the sand leakage port is formed at the lower end of the funnel section, wherein the sand leakage port is provided with an opening control switch. 16. The sand-rain method hollow cylinder sample preparation device for automatically controlling drop distance according to claim 15, wherein the angle between the inner wall surface of the funnel section and the horizontal plane is α, wherein α is greater than the The natural angle of repose of sand grains. 17. The sand-rain method hollow cylindrical sample preparation device according to any one of claims 1-11, wherein the suspension assembly comprises: a suspension wire, the suspension wire is connected with the sand storage assembly, and is used for hanging the sand storage assembly on the frame assembly; a reel, the reel is arranged on the frame assembly, and the reel is connected to the suspension wire to drive the suspension wire to extend and retract. 18. The sand-rain method hollow cylinder sample preparation device for automatically controlling the drop distance according to any one of claims 1-11, wherein the sample mold comprises a mold outer cylinder and a mold inner cylinder, and the The outer mold cylinder is sleeved on the outer side of the inner mold cylinder, and a cavity for accommodating is defined between the outer mold cylinder and the inner mold cylinder. 19 . The sand-rain method hollow cylindrical sample preparation device with automatic drop distance control according to claim 18 , wherein the accommodating cavity is formed in an annular shape, and the sand leakage port is located on the center line of the accommodating cavity. 20 .

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