Automatic throwing and unloading type frozen soil sample positioning and retaining device

Abstract

The utility model discloses an automatic dumping type frozen soil sample positioning retaining device, which belongs to the technical field of frozen soil mechanics triaxial test auxiliary work, and comprises an upper pressure head, a retainer main body and a lower pressure head, an unlocking ring is arranged on the upper pressure head, the upper pressure head is arranged above the retainer main body, and the lower pressure head is arranged below the retainer main body. The retainer main body is arranged above the lower pressing head, the retainer main body is a cylindrical shell, and an unlocking cavity is formed in the top of the retainer main body. By adopting the automatic throwing and unloading type frozen soil sample positioning and retaining device disclosed by the utility model, the moisture loss and the shape change of the frozen soil sample can be avoided in the early-stage preparation stage of a low-temperature triaxial test, the automatic throwing and unloading of a cylindrical shell can be realized after re-freezing and before the axial pressure starts to be loaded, and the test result is not influenced.

Description

Technical Field

[0001] The utility model relates to the technical field of auxiliary work of triaxial test of frozen soil mechanics, in particular to an automatic dumping type frozen soil sample positioning and holding device. Background Art

[0002] The triaxial test equipment for frozen soil samples usually needs to cool the temperature in the confining pressure chamber to below 0°C through a low-temperature circulation system. Currently, most common low-temperature circulation triaxial test devices maintain low temperatures by circulating low-temperature antifreeze in the confining pressure chamber, which requires the confining pressure chamber to be filled with antifreeze before circulation can begin.

[0003] For large-volume confining pressure cavities, the initial loading process of frozen soil samples and the initial process of inputting liquid into the confining pressure cavity take a long time. In this process, frozen soil with a high ice content at room temperature often melts, collapses and deforms, and ice crystals in the soil melt and then lose a large amount of water, causing the mechanical structure of the sample to change completely, affecting the test results and making the test impossible. Therefore, it is very necessary to develop a device that can keep the cylindrical sample from deforming before the formation of a low-temperature environment, prevent the loss of ice crystals after melting into water, and not affect the normal compression test under triaxial conditions after the sample is re-frozen after the formation of the low-temperature environment. Utility Model Content

[0004] The utility model aims to provide an automatic unloading frozen soil sample positioning and holding device, which can keep the frozen soil sample from losing moisture and changing its shape in the early preparation stage of low-temperature triaxial test, and can realize automatic unloading of the cylindrical shell before the axial pressure starts to load after refrozen, without affecting the test results.

[0005] To achieve the above-mentioned purpose, the utility model provides an automatic unloading frozen soil sample positioning and retaining device, including an upper pressure head, a retainer body and a lower pressure head, the upper pressure head is provided with an unlocking ring, the upper pressure head is arranged above the retainer body, the retainer body is placed above the lower pressure head, the retainer body is a cylindrical shell, and an unlocking cavity is provided on the top of the retainer body.

[0006] Preferably, the number of the unlocking rings is two, the unlocking rings are connected to the upper pressure head via a connecting piece, and the unlocking rings are made of iron wire.

[0007] Preferably, the connecting piece is cylindrical, a reserved hole is provided on the connecting piece, the unlocking ring is inserted through the reserved hole, and a laser positioning point is provided on the connecting piece.

[0008] Preferably, the unlocking cavity is a hollow cavity, and the unlocking cavity matches the shape of the unlocking ring.

[0009] Preferably, the retainer body is divided into two parts, a left part and a right part, and the left and right parts of the retainer body are respectively provided with a latch head and a latch head hole, and the latch head and the latch head hole correspond to each other one by one.

[0010] Preferably, a laser device is provided inside the retainer body.

[0011] Preferably, a reserved inclined surface is provided on the lower pressure head, and a water locking ring is provided on the top of the reserved inclined surface.

[0012] Therefore, the utility model adopts the above-mentioned automatic unloading frozen soil sample positioning and holding device, which can keep the frozen soil sample from losing moisture and changing its shape in the preliminary preparation stage of the low-temperature triaxial test, so that its structure remains basically unchanged, and at the same time, the sample can correspond to the position of the upper pressure head. After the low-temperature circulation system of the triaxial test instrument starts working and the temperature drops below zero, the cylindrical shell can be automatically unloaded before the axial pressure starts to load after refrozen. The refrozen sample is basically the same as the original sample and does not affect the test results.

[0013] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a top view and a front view of the upper pressure head of an embodiment of an automatic dumping type frozen soil sample positioning and holding device of the utility model;

[0015] Figure 2 It is a schematic diagram of a retainer body of an embodiment of an automatic dumping type frozen soil sample positioning and retaining device of the utility model;

[0016] Figure 3 It is a top view of the retainer body of an embodiment of an automatic dumping type frozen soil sample positioning and retaining device of the utility model;

[0017] Figure 4 It is a front view and a top view of the lower pressure head of an embodiment of an automatic dumping type frozen soil sample positioning and holding device of the utility model;

[0018] Figure 5 The utility model is a schematic diagram of the position of the lower pressure head during assembly of an embodiment of an automatic dumping type frozen soil sample positioning and holding device.

[0019] Reference numerals

[0020] 1. Unlocking ring; 2. Laser positioning point; 3. Connector; 4. Unlocking cavity; 5. Plug lock; 6. Plug lock hole; 7. Laser device; 8. Water locking ring; 9. Reserved inclined surface. DETAILED DESCRIPTION

[0021] The technical solution of the utility model is further described below through the accompanying drawings and embodiments.

[0022] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] Embodiment 1

[0024] like Figure 1-5 As shown, the utility model provides an automatic unloading frozen soil sample positioning and retaining device, including an upper pressure head, a retainer body and a lower pressure head, the upper pressure head is arranged above the retainer body, and an unlocking ring 1 is provided on the upper pressure head. The number of the unlocking rings 1 is two, and the unlocking ring 1 is connected to the upper pressure head through a connecting piece 3. The unlocking ring 1 is composed of an iron wire with a certain rigidity.

[0025] The connecting member 3 is cylindrical and has a reserved hole. The unlocking ring 1 is inserted through the reserved hole. The unlocking ring 1 can rotate around the hole. Under the action of gravity, the unlocking ring 1 is Figure 1 The front view in the middle and lower part shows the natural drooping state. A laser positioning point 2 is provided on the connecting member 3, and the laser positioning point 2 is a marking point and has no actual shape.

[0026] The retainer body is a cylindrical shell, and an unlocking cavity 4 is provided on the top of the retainer body. The unlocking cavity 4 is a cavity, and the unlocking cavity 4 matches the shape of the unlocking ring 1. When the upper pressure head is pressed downward by an external device, the unlocking ring 1 is pressed into the unlocking cavity 4, so that the retainer body is separated.

[0027] The retainer body is divided into two parts, a left part and a right part, and a latch head 5 and a latch head hole 6 are respectively provided on the left and right parts of the retainer body. The latch head 5 and the latch head hole 6 correspond to each other one by one. The bite device composed of the latch head 5 and the latch head hole 6 is an arc. The effect of the arc shape is that when it bites, it has a binding force in both the horizontal and vertical directions, so as to maintain the shape of the sample in the cavity of the retainer body, and the bite can only be released when the shell rotates around the point O.

[0028] A laser device 7 is provided inside the retainer body. The laser device 7 has a built-in laser pen commonly found on the market. The laser pen serves to aim at the position of the upper pressure head. The shape and size of the laser pen can be changed without affecting the function.

[0029] The diameter and height of the sample are consistent with the dimensions of the cavity when the retainer body is combined. The sample is placed in the cavity and the locking head 5 is inserted into the locking head hole 6 to engage. The position of the lower pressure head is as follows: Figure 4 As shown, the sample is placed on the pressure head, but the pressure head and the retainer housing are in contact with each other by gravity. The outside of the sample is completely wrapped by a cylindrical latex film, the bottom of the latex film is put on the pressure head, and is tied by a rubber band at the position of the water lock ring 8, so that the water in the sample will not be lost after melting and will continue to remain inside the sample.

[0030] The upper pressure head is not in contact with the other two at the beginning, but is above them with a certain space. The upper pressure head is aligned with the sample and other parts by judging whether the laser point emitted by the laser device 7 falls on the laser positioning point 2. After alignment, the confining pressure chamber falls, and the whole is located in the space invisible to the naked eye in the confining pressure chamber. When the confining pressure chamber is filled with coolant, the low-temperature cycle starts to work, the temperature drops to the target temperature, and the cylindrical sample inside is refrozen, the upper pressure head starts to fall.

[0031] Due to the pre-aiming of the laser device 7, the unlocking ring 1 will be inserted into the unlocking cavity 4 first during the descent of the upper pressure head, and as the descent continues, the unlocking ring 1 will push open the two parts of the retainer shell, and the two parts will rotate around point O at the same time. The bottom of the retainer shell will shrink inward, but the inclined surface 9 is reserved to allow it to move. After descending to a certain extent, the two parts of the retainer shell are completely separated. The existence of the outer wall of the unlocking cavity 4 ensures that the unlocking ring will not be scratched, ensuring the success of the unlocking process.

[0032] After the shell is dumped, the upper pressure head continues to drop until it contacts the sample, and the formal test begins. Since the unlocking ring 1 can rotate around the connector 3, the sample will not be affected by force when it touches the unlocking ring 1 during the test (the force can be ignored and is very small and will not affect the test results).

[0033] Therefore, the utility model adopts the above-mentioned automatic unloading frozen soil sample positioning and holding device, which can keep the frozen soil sample from losing moisture and changing its shape in the preliminary preparation stage of the low-temperature triaxial test, and can realize automatic unloading of the cylindrical shell before the axial pressure starts to load after refrozen, without affecting the test results.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the utility model with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the utility model.

Claims

1. An automatic dumping type frozen soil sample positioning and holding device, characterized in that: It includes an upper pressure head, a retainer body and a lower pressure head, wherein the upper pressure head is provided with an unlocking ring, the upper pressure head is arranged above the retainer body, the retainer body is placed above the lower pressure head, the retainer body is a cylindrical shell, and an unlocking cavity is provided on the top of the retainer body.

2. The automatic dumping type frozen soil sample positioning and holding device according to claim 1 is characterized in that: The number of the unlocking rings is two, and the unlocking rings are connected to the upper pressure head through a connecting piece, and the unlocking rings are made of iron wires.

3. The automatic dumping type frozen soil sample positioning and holding device according to claim 2 is characterized in that: The connecting piece is cylindrical, a reserved hole is arranged on the connecting piece, the unlocking ring is inserted through the reserved hole, and a laser positioning point is arranged on the connecting piece.

4. The automatic dumping type frozen soil sample positioning and holding device according to claim 1 is characterized in that: The unlocking cavity is a hollow cavity, and the unlocking cavity matches the shape of the unlocking ring.

5. The automatic dumping type frozen soil sample positioning and holding device according to claim 1 is characterized in that: The retainer body is divided into two parts, a left part and a right part. The left and right parts of the retainer body are respectively provided with a latch head and a latch head hole, and the latch head and the latch head hole correspond to each other one by one.

6. The automatic dumping type frozen soil sample positioning and holding device according to claim 5 is characterized in that: A laser device is arranged inside the holder body.

7. The automatic dumping type frozen soil sample positioning and holding device according to claim 1 is characterized in that: The lower pressure head is provided with a reserved inclined surface, and the top of the reserved inclined surface is provided with a water locking ring.

Images