CN115508217B - Multifunctional testing machine and method capable of realizing vacuum hot pressing and gas adsorption - Google Patents

Abstract

The invention relates to a multifunctional testing machine and a method capable of realizing vacuum hot pressing and gas adsorption, wherein the multifunctional testing machine comprises a frame, a testing box is fixed on the frame, an inner cavity of the testing box is a testing cavity, the diameter of the testing cavity is larger than that of a sample to be prepared, a plug is arranged at an opening at the top of the testing cavity, an air hole is formed in the plug, a first vertical loading piece mounted on the frame is arranged above the plug, a second vertical loading piece is arranged below the testing box, a loading part of the second vertical loading piece extends into the testing cavity, and the multifunctional testing machine further comprises a testing piece mould capable of being placed into the testing cavity, wherein the inner diameter of the testing piece mould is matched with the outer diameter of the loading part of the second vertical loading piece.

Description

Multifunctional testing machine and method capable of realizing vacuum hot pressing and gas adsorption

Technical Field

The invention relates to the technical field of geotechnical testing equipment, and in particular to a multifunctional testing machine and method capable of realizing vacuum hot pressing and gas adsorption.

Background technique

The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

Since coal-like rock similar material specimens have good homogeneity and isotropy, and match the continuous medium mechanics currently used in research, more and more scholars use coal-like rock similar material specimens to replace raw coal specimens. However, due to the lack of high-end instruments for making coal-like rock similar material specimens, most of them use artificial cold pressing methods, which is not only difficult to demold, has a low success rate, and consumes a lot of manpower and material resources, but also has the disadvantages of high discreteness, low strength, and large differences in properties from raw coal.

At the same time, with the deepening of research on coal and gas outbursts, gas adsorption strength test is becoming more and more extensive. Gas adsorption test has high requirements on the sealing of instruments. The original testing machine cannot meet its test requirements, and it is necessary to re-develop instruments specifically for gas adsorption. Therefore, the use of coal-like rock similar material specimens for gas adsorption strength test is complicated. Generally, two instruments are required: coal-like rock similar material specimen production instrument and gas adsorption strength test instrument, and the test cost is high.

Therefore, many scholars have developed a large number of test instruments for the preparation of coal-like and rock-like material specimens and gas adsorption strength testing. However, the inventors found that there are few studies that can integrate the two test functions into one experimental device, so there is an urgent need for a multifunctional testing machine and test method that can meet the requirements of the preparation of coal-like and rock-like material specimens and the gas adsorption strength testing.

Summary of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a multifunctional testing machine and method capable of realizing vacuum hot pressing and gas adsorption. A set of testing machines can integrate multiple functions of specimen preparation and testing, and the testing cost is low.

To achieve the above purpose, the present invention adopts the following technical solutions

In the first aspect, an embodiment of the present invention provides a multifunctional testing machine that can realize vacuum hot pressing and gas adsorption, including a frame, a test box is fixed to the frame, the internal cavity of the test box is a test cavity, the internal cavity diameter of the test cavity is larger than the diameter of the sample to be prepared, a plug is provided at the open top of the test box, the plug is provided with an air hole, a first vertical loading member installed on the frame is provided above the plug, a second vertical loading member is provided below the test box, a loading component of the second vertical loading member extends into the test cavity, and also includes a specimen mold that can be placed in the test cavity, the inner diameter of the specimen mold matches the outer diameter of the loading component of the second vertical loading member.

Optionally, a sealing ring is provided between the plug and the top surface of the test box, and a dynamic sealing assembly is provided between the loading component of the second vertical loading member and the test chamber.

Optionally, a heating component is disposed inside the side cavity wall of the test box, and the heating component is disposed on the inner surface of the side cavity wall.

Optionally, an upper water storage tray is provided on the top of the side cavity wall of the test chamber, and the upper water storage tray is connected to the external space of the test chamber through a drainage hole. A lower water storage tray is provided on the bottom of the side cavity wall of the test chamber, and the lower water storage tray is connected to the external space of the test chamber through a water inlet hole. A plurality of cooling water channels are provided between the upper water storage tray and the lower water storage tray, and the cooling water channels are provided on the outside of the heating component.

Optionally, the first vertical loading member adopts a servo electric cylinder loading mechanism.

Optionally, the second vertical loading member is a hydraulic cylinder, a cylinder body of the hydraulic cylinder is fixed to the frame, and a piston rod of the hydraulic cylinder extends into the test chamber.

Optionally, the specimen mold includes a first mold member and a second mold member with a semicircular cross-section, and the first mold member and the second mold member can be spliced into a cylindrical structure with an inner diameter equal to the outer diameter of the loading component of the second vertical loading member through a clamp.

In a second aspect, an embodiment of the present invention provides a method for implementing the multifunctional testing machine capable of vacuum hot pressing and gas adsorption as described in the first aspect, comprising the following steps:

The bottom end of the specimen mold is placed on the outer periphery of the loading component of the second vertical loading component to position the specimen in the test cavity;

Add coal-like and rock-like materials into the specimen mold;

The open top of the test box is sealed with a plug, the plug is in contact with the top of the coal-like material and a first set pressure is applied;

Then, the air holes on the plug are used to evacuate the mold and the internal space of the test cavity, and the air holes are closed after the evacuation is completed;

The second vertical loading member works to apply a second set pressure to the coal-like and rock-like material, and maintains the pressure for a set time;

After the coal-rock similar materials are pressurized, open the air holes and remove the plugs;

Take out the specimen mold and the prepared specimen, and after demoulding, put the specimen back into the test cavity for testing.

Optionally, the second vertical loading member works to push the test piece out of the test cavity, and the test piece is loaded by the first vertical loading member to perform a uniaxial compression test.

Optionally, after the test piece is put back into the test chamber, a plug is placed, and a third set pressure is applied to the plug using the first vertical loader, gas is injected into the test chamber through the air hole, and after the set gas adsorption time is reached, the test piece is loaded by the second vertical loader to carry out a strength test.

Beneficial effects of the present invention:

1. The multifunctional testing machine of the present invention has a diameter of the inner cavity of the test chamber that is larger than the diameter of the sample to be prepared, and the plug is provided with air holes. Therefore, when the sample mold is placed in the test chamber, the sample can be prepared by the first vertical loading member and the second vertical loading member. After the sample mold and the prepared sample are taken out and demolded, the sample is put back into the test chamber. The air holes, the first vertical loading member and the second vertical loading member can be used to perform uniaxial compression tests and gas adsorption strength tests. One set of equipment can be used for both sample preparation and sample testing, making full use of the common points of each test. There is no need to use multiple sets of equipment for testing, which reduces the number of instruments used and greatly reduces the test cost.

2. In the multifunctional testing machine of the present invention, the inner diameter of the test piece mold matches the outer diameter of the loading component of the second vertical loader, and the bottom end can be sleeved on the outer periphery of the loading component of the second vertical loader. The loading component is used for positioning in the test cavity, and no additional positioning component is required, which simplifies the structure of the testing machine and reduces the production cost of the testing machine.

3. In the multifunctional testing machine of the present invention, the test piece mold is fixed by two mold components through a clamp, and demoulding is simple and the operation is convenient and quick.

4. In the multifunctional testing machine of the present invention, a heating component is provided on the side cavity wall of the test box, a sealing ring is provided between the plug and the top of the test box, and a dynamic sealing assembly is provided between the loading component of the second vertical loading member and the test cavity, so that the heating and sealing structures are organically combined and unified, reducing the occupied space.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings in the specification, which constitute a part of the present application, are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

FIG1 is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

FIG2 is a schematic cross-sectional view of A in FIG1 of the present invention;

FIG3 is a schematic cross-sectional view of A in FIG1 when the gas adsorption strength test is performed in Example 2 of the present invention;

FIG4 is a schematic cross-sectional view of A in FIG1 during a uniaxial compression test of Example 2 of the present invention;

Among them, 1. upper fixing plate, 2. middle fixing plate, 3. lower fixing plate, 4. reaction column, 5. support column, 6. upper cover of test chamber, 7. lower cover of test chamber, 8. side chamber wall, 9. plug, 10. air hole, 11. servo motor, 12. cylinder body, 13. hydraulic cylinder, 14. piston rod, 15. dynamic sealing assembly, 16. cooling water channel, 17. upper water storage tray, 18. lower water storage tray, 19. drainage hole, 20. water inlet hole, 21. specimen mold, 22. clamp, 23. Muffler, 24. specimen.

Detailed ways

Example 1

This embodiment provides a multifunctional testing machine capable of realizing vacuum hot pressing and gas adsorption, as shown in FIG. 1-FIG . 2 , including a frame, a test chamber, a first vertical loading member, a second vertical loading member, a specimen mold and other components.

The frame serves as a basis for supporting other components, and includes an upper fixing plate 1, a middle fixing plate 2 and a lower fixing plate 3 which are arranged in parallel up and down. The upper fixing plate 1, the middle fixing plate 2 and the lower fixing plate 3 are all rectangular plates.

The upper fixing plate 1 and the middle fixing plate 2 are fixed as a whole through reaction columns 4 located at the four corners thereof, and the middle fixing plate 2 and the lower fixing plate 3 are fixed as a whole through support columns 5 located at the four corners thereof.

A test box is fixed on the middle fixed plate 2, and a test chamber is provided inside the test box. The test box includes a test chamber upper cover 6, a test chamber lower cover 7, and a side chamber wall 8 arranged between the test chamber upper cover and the test chamber lower cover. Both the test chamber upper cover 6 and the test chamber lower cover 7 are provided with openings, and the openings are connected with the test chamber so that the test chamber forms an open-ended structure at both ends.

Sealing rings are provided between the side cavity wall 8 and the test cavity upper cover 6 and the test cavity lower cover 7.

In this embodiment, the test cavity is a cylindrical cavity, and the diameter of the test cavity is larger than the diameter of the test piece to be prepared, so that the test cavity can be placed in the test piece mold.

A plug 9 is provided at the opening of the test chamber upper cover 6, and the plug 9 is used to seal the top open end of the test box. The plug 9 includes a first plugging part and a second plugging part which are coaxially arranged, and the diameter of the first plugging part is larger than the diameter of the second plugging part.

The second plugging part can be inserted into the opening of the test chamber upper cover 6, and the bottom end surface of the first plugging part can contact the upper surface of the test chamber upper cover 6, thereby realizing the positioning and fixation of the plug. A sealing ring is provided between the first plugging part and the test chamber upper cover 6.

A sealing ring is provided on the bottom surface of the first plugging portion, and the first plugging portion contacts the top surface of the test chamber upper cover 6 through the sealing ring, thereby achieving sealing of the top of the test chamber.

The plug 9 is provided with an air hole 10, which is used to evacuate the test chamber or inject gas into the test chamber. The air hole 10 includes a first air hole portion, and the two ends of the first air hole portion extend to the side of the plug. The first air hole portion is connected with the second air hole portion, and the second air hole portion extends to the bottom surface of the second plug portion, so that after the plug is placed on the upper cover of the test chamber, the air hole can connect the test chamber with the external space of the test box.

A first vertical loading member is arranged above the plug 9 , the first vertical loading member is arranged coaxially with the plug 9 , and the first vertical loading member is installed on the upper fixing plate.

In this embodiment, the first vertical loading member adopts a servo electric cylinder loading mechanism with a servo motor 11 as a power source, including a servo motor 11, a cylinder body 12, a screw and other components. The cylinder body 12 is fixed on the top surface of the upper fixed plate 1, and the servo motor 11 drives the screw inside the cylinder body 12 to perform vertical lifting and lowering movements, thereby applying a vertical load to the plug 9.

The servo electric cylinder loading mechanism can adopt existing equipment, and its specific structure will not be described in detail here.

In some other embodiments, the first vertical loading member is a component such as a hydraulic cylinder or a pneumatic cylinder that can output linear motion.

A second vertical loading member is provided below the test box. The second vertical loading member adopts a hydraulic cylinder 13 having an oil inlet and an oil outlet. The cylinder body of the hydraulic cylinder 13 is fixed to the bottom surface of the middle fixed plate 2. The piston rod 14 of the hydraulic cylinder 13, as a loading component, extends into the interior of the test chamber through the opening of the lower cover of the test chamber. In order to seal the bottom of the test chamber, a dynamic sealing assembly 15 is provided between the piston rod 14 of the hydraulic cylinder 13 and the lower cover 7 of the test chamber. The dynamic sealing assembly 15 can adopt an existing dynamic sealing assembly and will not be described in detail herein.

In this embodiment, the diameter of the piston rod 14 of the hydraulic cylinder 13 is 50 mm. When the piston rod of the hydraulic cylinder reaches the maximum retracted length, that is, the piston rod 14 is lowered to the lowest point, the end face of the piston rod 14 is 1-2 mm higher than the upper surface of the lower cover of the test chamber, so that the piston rod 14 extends into the interior of the test chamber. When the piston rod 14 rises to the highest point, its top is flush with the upper surface of the upper cover 6 of the test chamber.

The telescopic movement of the piston rod 14 of the hydraulic cylinder 13 can apply an axial load to the test piece from the bottom.

A heating component 15 is installed on the inner side of the side cavity wall 8 of the test box. The heating component 15 can be an existing heating sleeve for heating the inner space of the test cavity. The heating component 15 can also be an electric heating wire or other heating equipment.

A plurality of cooling water channels 16 are also provided in the side cavity wall 8 of the test chamber. The cooling water channels 16 are arranged along the axial direction of the test chamber. The cooling water channels are arranged on the outside of the heating sleeve. The top end thereof is connected to an upper water storage tray 17 arranged on the top of the side cavity wall of the test chamber, and the bottom end thereof is connected to a lower water storage tray 18 arranged on the bottom of the side cavity wall of the test chamber. The upper water storage tray 17 is connected to a drainage hole 19, and the drainage hole 19 connects the upper water storage tray 17 with the external space of the test chamber for discharging cooling water. The lower water storage tray 18 is connected to a water inlet hole 20, and the water inlet hole 20 connects the lower water storage tray 18 with the external space of the test chamber for introducing cooling water.

By providing the cooling water channel 16, the side cavity wall 8 of the test box can be cooled to avoid burns to test personnel caused by excessive temperature of the side cavity wall 8 when the heating sleeve is working. At the same time, the test cavity can be cooled quickly after heating is completed.

In this embodiment, a heating component is provided on the side cavity wall of the test box, and a sealing ring is provided between the plug 9 and the upper cover 6 of the test chamber, and a dynamic sealing assembly 15 is provided between the loading component of the second vertical loading member and the lower cover 7 of the test chamber, so that the heating and sealing structures are organically combined and unified, the structure is compact, and the space occupied is reduced.

The specimen mold 21 adopts a cylindrical structure, and its inner diameter matches the outer diameter of the piston rod 14 of the hydraulic cylinder, that is, its inner diameter is also 50 mm, which is the same as the outer diameter of the piston rod 14. After the specimen mold 21 is placed in the test cavity, the bottom end of the specimen mold 21 can be sleeved on the outer periphery of the piston rod 14, and the specimen mold 21 is positioned and fixed in the test cavity by using the piston rod 14.

To facilitate demoulding, the specimen mold 21 is formed by fixing a first mold component and a second mold component by a clamp 22. The cross-sections of the first mold component and the second mold component are both semicircular, and the first mold component and the second mold component can be spliced into a cylindrical structure.

When in use, the clamp 22 is removed and the first mold component and the second mold component are separated, so that demoulding can be achieved, and demoulding is convenient and quick.

In this embodiment, in order to facilitate the movement of the entire testing machine, running wheels are installed at the four corners of the bottom surface of the lower fixed plate. The running wheels are Muffle wheels 23, which facilitates the test personnel to move the testing machine.

Example 2

This embodiment provides a method for realizing the multifunctional testing machine of vacuum hot pressing and gas adsorption as described in Embodiment 1, comprising the following steps:

Step 1: Place the specimen mold 21 into the test chamber. The first mold component and the second mold component of the specimen mold are sleeved on the outer periphery of the piston rod 14 of the hydraulic cylinder 13 and fixed with a clamp 22. Add the prepared coal-like rock-like material into the specimen mold 21, and then cover the opening of the test chamber upper cover 6 with a plug 9. Then turn on the switch of the heating sleeve to heat the inside of the test chamber to a predetermined temperature. At the same time, cooling water is introduced into the water inlet 20. The cooling water passes through the lower water storage tray 18, the cooling water channel 16 and the upper water storage tray 17 and then flows out through the drain hole 19 to cool the side cavity wall 8 of the test box.

Step 2: The first vertical loading member works so that its loading component contacts the plug 9 and applies a first set pressure to the plug 9. The first set pressure is the maximum pressure of the specimen loading. Then, the air hole 10 of the plug 9 is connected to the vacuum equipment, and the interior of the specimen mold 21 and the interior space of the test chamber are vacuumed. After the vacuuming is completed, the air hole 10 is closed by closing the valve on the pipeline of the vacuum equipment.

Step 3: The second vertical loader works so that its loading component applies a second set pressure to the coal-like rock similar material. The second set pressure is the pressure required for specimen preparation. The pressure is maintained for a set time. After the pressurization of the coal-like rock similar material specimen is completed, the heating sleeve switch is turned off.

Step 4: After the specimen is cooled, stop injecting cooling water into the cooling water channel 16, lift the loading component of the first vertical loading component to the highest position, open the air hole 10, make the internal pressure of the test chamber equal to the external air pressure, and remove the plug 9.

Step 5: Take out the specimen mold 21 and the prepared specimen 24 in the test cavity, and then loosen the clamp 22 to demould.

Step 6: Place the prepared test piece 24 back into the test chamber and conduct the test.

Specifically, as shown in Figure 4, when a uniaxial compression test is performed, the loading component of the second vertical loading member lifts the specimen 24. After the end of the loading component is flush with the upper surface of the test chamber cover 6, the specimen 24 is pushed out to the top of the outside of the test chamber, and then the first vertical loading member applies pressure to the specimen to perform a uniaxial compression test.

As shown in Figure 3, when conducting a gas adsorption strength test, the opening of the test chamber upper cover 6 is covered with a plug 9, and the first vertical loading component is operated to apply a third set pressure to the plug 9. The third set pressure is greater than the strength of the coal-like rock similar material specimen. The adsorbed gas is injected into the test chamber through the pores 10. After the gas adsorption set time, the specimen is loaded through the second vertical loading component to start the strength test.

If the experimental temperature requires constant temperature, the temperature in the test chamber is controlled by a heating sleeve.

The testing machine of this embodiment makes full use of the common points of various tests, integrates test piece production, gas adsorption and strength testing, reduces the number of test instruments, and reduces the test cost.

At the same time, hot pressing and vacuum forming make demoulding simple, the test piece has a high success rate, high strength, and is similar to the properties of the original coal.

Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that various modifications or variations that can be made by technical personnel in the field without creative work on the basis of the technical solution of the present invention are still within the scope of protection of the present invention.

Claims (6)

1. A method of a multifunctional testing machine capable of realizing vacuum hot pressing and gas adsorption is characterized in that,

The adopted multifunctional testing machine capable of realizing vacuum hot pressing and gas adsorption comprises a frame, wherein the frame is fixedly provided with a testing box, the internal cavity of the testing box is a testing cavity, the diameter of the testing cavity is larger than that of a sample to be prepared, a plug is arranged at an opening at the top of the testing cavity, an air hole is formed in the plug, a first vertical loading piece installed on the frame is arranged above the plug, a second vertical loading piece is arranged below the testing box, a loading part of the second vertical loading piece stretches into the testing cavity, and the multifunctional testing machine also comprises a test piece mould capable of being placed into the testing cavity, and the inner diameter of the test piece mould is matched with the outer diameter of the loading part of the second vertical loading piece;

The heating component is arranged in the side cavity wall of the test box, the heating component is arranged on the inner surface of the side cavity wall of the test box, an upper water storage disc is arranged at the top of the side cavity wall of the test box of the multifunctional tester capable of realizing vacuum hot pressing and gas adsorption, the upper water storage disc is communicated with the outer space of the test cavity through a drain hole, a lower water storage disc is arranged at the bottom of the side cavity wall of the test box, the lower water storage disc is communicated with the outer space of the test cavity through a water inlet hole, a plurality of cooling water channels are arranged between the upper water storage disc and the lower water storage disc, and the cooling water channels are arranged at the outer side of the heating component;

the method comprises the following steps:

Sleeving the bottom end of the test piece die at the periphery of a loading part of the second vertical loading piece, and positioning in the test cavity;

Adding similar materials of coal and rock into a test piece mould;

The heating component is opened to heat the inside of the test cavity to reach a preset temperature, and meanwhile cooling water is introduced into the water inlet hole to cool the side cavity wall of the test box;

plugging the top opening of the test box by using a plug, contacting the plug with the top of the similar material of the coal-like rock and applying a first set pressure;

Then the air holes on the plug are utilized to vacuumize the inner space of the test piece mould and the test cavity, and the air holes are closed after the vacuumization is finished;

The second vertical loading piece works, applies a second set pressure to similar materials of the coal-like rock, and maintains the pressure for a set time;

Opening the air hole after the similar material of the coal-like rock is pressurized, removing the plug, and closing the heating component;

and after the test piece is cooled, closing the cooling water channel, taking out the test piece mould and the prepared test piece, and putting the test piece into the test cavity again for test after demoulding.

2. The method of claim 1, wherein a sealing ring is provided between the plug and the top surface of the test chamber, and a dynamic sealing assembly is provided between the loading component of the second vertical loading element and the test chamber.

3. The method for realizing the vacuum hot pressing and gas adsorption multifunctional testing machine according to claim 1, wherein the first vertical loading piece adopts a servo electric cylinder loading mechanism, the second vertical loading piece adopts a hydraulic cylinder, a cylinder body of the hydraulic cylinder is fixed on the frame, and a piston rod of the hydraulic cylinder extends into the testing cavity.

4. The method of claim 1, wherein the test piece mold comprises a first mold member and a second mold member having a semicircular cross section, the first mold member and the second mold member being capable of being joined by a clip to form a cylindrical structure having an inner diameter equal to an outer diameter of the second vertical loader loading member.

5. The method of a multifunctional testing machine capable of realizing vacuum hot pressing and gas adsorption according to claim 1, wherein the second vertical loading piece works, the test piece is ejected out of the testing cavity, and the first vertical loading piece is used for loading the test piece to perform a uniaxial compression test.

6. The method for realizing the vacuum hot pressing and gas adsorption multifunctional testing machine according to claim 1, wherein after the test piece is put into the testing cavity again, the plug is placed, the first vertical loading piece is utilized to apply a third set pressure to the plug, gas is injected into the testing cavity through the air hole, after the set gas adsorption time is reached, the test piece is loaded through the second vertical loading piece, and the strength test is carried out.