Low-temperature rock wear resistance test device and test method

Abstract

The invention discloses a low-temperature rock wear resistance testing device and testing method, and belongs to the technical field of rock wear resistance testing. The low-temperature rock wear resistance test device comprises a counter-force frame and a drill bit system, and further comprises a sample box for containing a rock sample; the cooling system comprises refrigeration equipment, a low-temperature pipeline and a low-temperature guide head, the refrigeration equipment is communicated with the low-temperature pipeline, the low-temperature pipeline is communicated with the low-temperature guide head, the low-temperature guide head is arranged in the sample box, and the low-temperature guide head is attached to the rock sample; the temperature measuring system is used for detecting the real-time temperature of the rock sample; a temperature is preset in the controller, and the controller compares the real-time temperature with the preset temperature to control the operation of the cooling system, so that the real-time temperature of the rock sample is equal to the preset temperature. According to the low-temperature rock wear resistance testing device, the wear resistance of a frozen rock stratum can be researched, the influence of different low-temperature conditions on the wear resistance of the rock is explored, and the tunneling efficiency of shaft construction under the low-temperature condition is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of rock wear resistance testing, and in particular to a low-temperature rock wear resistance testing device and a testing method. Background Art

[0002] During shaft construction, mechanical tunnel boring machines are required for excavation. Accurately measuring rock wear resistance is an important basis for efficient tunneling. The wear resistance of rock is often determined based on the steel needle method combined with a rock wear tester. The strata traversed by mines in the western region are mainly Jurassic-Cretaceous strata. They are late in diagenesis, poorly cemented, low in strength, and soften when exposed to water. They are weak and unstable rock formations. There are also many porous and fissured aquifers. When the bedrock aquifer has a large amount of water inflow, freezing methods have to be used to stop water and improve the strength of the weak surrounding rock. When the soft rock is frozen in a low-temperature environment, the water inside the rock freezes into ice, the pore structure changes, and the physical and chemical process of water-ice phase transition causes significant changes in the mechanical properties of the rock. In order to understand the excavation efficiency of mechanical tunneling tools in low-temperature rock areas, it is necessary to obtain the rock wear resistance value under low-temperature conditions.

[0003] The core components of traditional rock wear resistance testing instruments include a drill bit and a sample box. The sample box is used to fix the rock sample, and then the drill bit is used to scratch the rock sample in the sample box. The wear resistance of the rock sample is then reflected by measuring the depth of the scratch on the surface of the rock sample. However, traditional rock wear resistance testing instruments can only test rock samples at room temperature and cannot restore the state of rock under simulated low-temperature conditions when it is subjected to stress. It cannot obtain the wear resistance of low-temperature rock and cannot meet the research needs of related construction projects. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems in the prior art and provide a low-temperature rock wear resistance testing device that can study the wear resistance of frozen rock formations, explore the impact of different low-temperature conditions on rock wear resistance, and further improve the excavation efficiency of wellbore construction under low-temperature conditions.

[0005] The present invention provides a low-temperature rock wear resistance test device, comprising a reaction frame and a drill bit system, wherein the drill bit system is arranged on the reaction frame and is used to scratch a rock sample for testing, and further comprises: A sample box is provided below the drill bit system and is used to hold rock samples; A cooling system includes a refrigeration device, a cryogenic pipeline, and a cryogenic guide head. The refrigeration device is connected to the cryogenic pipeline, the cryogenic pipeline is connected to the cryogenic guide head, and the cryogenic guide head is arranged in the sample box and fits the rock sample. A temperature measurement system is provided in the sample box, and is used to detect the real-time temperature of the rock sample; The controller is electrically connected to the cooling system and the temperature measuring system. The controller has a preset temperature. The controller controls the operation of the cooling system based on the comparison between the real-time temperature and the preset temperature so as to make the real-time temperature of the rock sample equal to the preset temperature.

[0006] Preferably, the cooling system includes two low-temperature guide heads, both of which are connected to the low-temperature guide head, and the two low-temperature guide heads are respectively attached to the two sides of the rock sample.

[0007] Preferably, the temperature measuring system includes two groups of temperature measuring plates, both of which are electrically connected to the controller. One group of temperature measuring plates is arranged on the surface of the low-temperature guide head, and the other group of temperature measuring plates is arranged on one side of the upper surface of the rock sample where it is to be scratched.

[0008] Preferably, a slide rail system is provided below the reaction frame, and the slide rail system includes a sliding rail and a driving mechanism. The sliding rail is arranged below the drill bit system, and the length direction of the sliding rail is parallel to the upper surface of the rock sample. The driving mechanism is connected to the slide rail system, and the sample box is connected to the driving mechanism. The driving mechanism is used to drive the sample box to slide on the sliding rail along the length direction of the sliding rail.

[0009] Preferably, a first limiter is provided at one end of the sliding track, and a second limiter is provided at the other end of the sliding track. The first limiter and the second limiter are electrically connected to a controller, and the controller is electrically connected to the motor. During the movement of the sample box on the sliding track, when the sample box contacts the first limiter or the second limiter, the controller controls the motor to stop moving.

[0010] Preferably, the drill system includes a lifting mechanism and a steel needle, the lifting mechanism is connected to the reaction frame, the lifting mechanism is connected to a chuck, the steel needle is clamped on the chuck, and the lifting mechanism is used to drive the steel needle to move in the vertical direction.

[0011] Preferably, a force sensor is connected to the steel needle, and the force sensor is used to detect the real-time pressure value applied by the steel needle to the rock sample. The force sensor is electrically connected to a controller, and the controller is electrically connected to the lifting mechanism. A pressure value is preset in the controller. When the real-time pressure value is equal to the preset pressure value, the controller controls the lifting mechanism to stop moving.

[0012] The method for conducting a test using a low-temperature rock wear resistance test device comprises the following steps: Cooling the rock sample to a target temperature, i.e., a preset temperature, and then placing the rock sample in a sample box; Placing a sample box containing a rock sample under the drill head system, and then controlling the movement of the drill head system so that the drill head system presses against the upper surface of the rock sample and applies a predetermined downward pressure to the upper surface of the rock sample; The temperature measurement system is used to detect the real-time temperature of the rock sample, and the controller controls the cooling system according to the real-time temperature of the rock sample to keep the rock sample at the preset temperature; The test box is then driven to move horizontally, so that the upper surface of the rock sample is scratched using the drill system. By detecting the depth of the scratches on the upper surface of the rock sample, the wear resistance of the rock sample at low temperatures can be determined.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: a low-temperature rock wear resistance test device of the present invention places a sample box containing a rock sample under a drill bit system, and then controls the action of the drill bit system to press the upper surface of the rock sample with the drill bit system and apply a predetermined downward pressure to the upper surface of the rock sample, and uses a temperature measurement system to detect the real-time temperature of the rock sample. The controller controls the action of the cooling system according to the real-time temperature of the rock sample to keep the rock sample at a preset temperature, and then drives the test box to move horizontally, thereby using the drill bit system to scratch the upper surface of the rock sample, and by detecting the depth of the scratch on the upper surface of the rock sample, the wear resistance of the rock sample at low temperature can be learned, so that the wear resistance of the frozen rock layer can be studied, the influence of different low-temperature conditions on the wear resistance of the rock can be explored, and the excavation efficiency of wellbore construction under low-temperature conditions can be further improved.

[0014] By setting up two low-temperature guide heads and using them to cool the rock sample from both sides of the rock sample, the overall temperature distribution of the rock sample can be made more balanced, thereby improving the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the test bench of the present invention; Figure 2 is a schematic diagram of the drill system of the present invention; Figure 3 It is a schematic diagram of a sample box of the present invention; Figure 4 The utility model relates to a pull rod and a clamping block of the present invention.

[0016] Description of reference numerals: 1. Base; 2. Reaction frame; 3. Sliding track; 4. Temperature measuring plate; 5. Pull rod box; 6. First limiter; 7. Second limiter; 8. Roller; 9. Sample box; 10. Clamping block; 11. Pull rod; 12. Screw hole; 13. Screw; 14. Gasket; 15. Rock sample; 16. Wire outlet; 17. Cryogenic pipeline; 18. Cryogenic guide head; 19. Lifting mechanism; 20. Force sensor; 21. Chuck; 22. Steel needle. DETAILED DESCRIPTION

[0017] The following is combined with Figure 1-Figure 4, the specific embodiments of the present invention are described in detail, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] like Figure 1-Figure 4 As shown, the present invention provides a low-temperature rock wear resistance test device, which includes a reaction frame 2 and a drill bit system. The drill bit system is arranged on the reaction frame 2 and is used to scratch the test rock sample 15. It also includes: a sample box 9, a cooling system, a temperature measurement system and a controller. The sample box 9 is arranged below the drill bit system and is used to hold the rock sample 15; the cooling system includes a refrigeration device, a low-temperature pipeline 17 and a low-temperature guide head 18. The refrigeration device is connected to the low-temperature pipeline 17, and the low-temperature pipeline 17 is connected to the low-temperature guide head 18. The low-temperature guide head 18 is arranged in the sample box 9 and fits the rock sample 15; the temperature measurement system is arranged in the sample box 9 and is used to detect the real-time temperature of the rock sample 15; the controller is electrically connected to the cooling system and the temperature measurement system, and a temperature is preset in the controller. The controller compares the real-time temperature with the preset temperature to control the operation of the cooling system so that the real-time temperature of the rock sample 15 is equal to the preset temperature.

[0019] The working principle of the above embodiment is briefly described below: The reaction frame 2 is mounted on the base 1. The sample box 9 is a metal, welded rectangular solid with an open end. The inner wall is padded with plastic. Screw holes 12 are provided on the front and rear sides of the sample box 9. Screws 13 are screwed in through gaskets 14 to secure the rock sample 15 within the inner cavity of the sample box 9. Outlets 16 for cryogenic piping 17 are located on the left and right side walls of the sample box 9. The cryogenic guide 18 in the cooling system is square. During testing, the cryogenic guide 18 adheres closely to the surface of the rock sample 15, delivering low temperatures. The cryogenic piping 17 in the cryogenic system exits through the outlets 16 on the side walls of the sample box 9. The cryogenic piping 17 is flexible and moves with the movement of the sample box 9. During the test, the rock sample 15 is first cooled to a target temperature, i.e., a preset temperature. The rock sample 15 is then placed in a sample box 9 to begin the test. The sample box 9 containing the rock sample 15 is placed below the drill system. The drill system is then controlled to press against the upper surface of the rock sample 15 and apply a predetermined downward pressure to the upper surface of the rock sample 15. The temperature measurement system is used to detect the real-time temperature of the rock sample 15. The controller controls the operation of the cooling system based on the real-time temperature of the rock sample 15 to maintain the preset temperature of the rock sample 15. The test box is then driven to move horizontally, so that the upper surface of the rock sample 15 is scratched by the drill system. By detecting the depth of the scratch on the upper surface of the rock sample 15, the wear resistance of the rock sample 15 at low temperatures is determined.

[0020] The low-temperature rock wear resistance testing device of the present invention can conduct research on the wear resistance of frozen rock formations, explore the influence of different low-temperature conditions on the wear resistance of rocks, and further improve the excavation efficiency of wellbore construction under low-temperature conditions.

[0021] On the basis of the above embodiment, in order to make the overall temperature distribution of the rock sample 15 more balanced, the accuracy of the test results is improved.

[0022] like Figure 2 As shown, the cooling system includes two low-temperature guide heads 18 , both of which are connected to the low-temperature guide head 18 , and the two low-temperature guide heads 18 are respectively attached to both sides of the rock sample 15 .

[0023] By providing two low-temperature guide heads 18 and using the two low-temperature guide heads 18 to cool the rock sample 15 from both sides of the rock sample 15 , the overall temperature distribution of the rock sample 15 can be made more balanced, thereby improving the accuracy of the test results.

[0024] As a preferred solution, Figure 2 As shown, the temperature measurement system includes two sets of temperature measuring plates 4, both of which are electrically connected to the controller. One set of temperature measuring plates 4 is disposed on the surface of the cryogenic guide 18, and the other set of temperature measuring plates 4 is disposed on one side of the location on the upper surface of the rock sample 15 where the scratching is to be performed. One set of temperature measuring plates 4 is disposed on the surface of the cryogenic guide 18, and the other set of temperature measuring plates 4 is disposed on one side of the location on the upper surface of the rock sample 15 where the scratching is to be performed. The two sets of temperature measuring plates 4 are used to respectively detect the real-time temperature of the cryogenic guide 18 and the location on the upper surface of the rock sample 15 where the scratching is to be performed. The real-time temperatures measured by the two sets of temperature measuring plates 4 are compared to verify the set temperature, thereby comparing it with the preset temperature, improving the cooling accuracy of the cooling system, and ensuring the accuracy of the test.

[0025] As a preferred solution, Figure 1 and Figure 3As shown, a slide rail system is provided below the reaction frame 2. The slide rail system includes a sliding track 3 and a drive mechanism. The sliding track 3 is provided below the drill head system, and the length direction of the sliding track 3 is parallel to the upper surface of the rock sample 15. The drive mechanism is connected to the slide rail system, and the sample box 9 is connected to the drive mechanism. The drive mechanism is used to drive the sample box 9 to slide along the length direction of the sliding track 3. By providing the slide rail system, when the drive mechanism drives the sample box 9 to slide on the sliding track 3, since the length direction of the sliding track 3 is parallel to the upper surface of the rock sample 15, the movement trajectory of the drill head system relative to the rock sample 15 in the test box is parallel to the upper surface of the rock sample 15, thereby ensuring that the pressure applied by the drill head system to the upper surface of the rock sample 15 is constant, further ensuring the accuracy of the test results. The base 1 has two rows of rollers 8 to facilitate the left and right sliding of the sample box 9 and reduce the force on the pull rod 11.

[0026] As a preferred solution, Figure 1 、 Figure 3 and Figure 4 As shown, the sliding track 3 and the motor are fixed to the base 1, and a clamping block 10 is welded to the bottom of the sample box 9. The sample box 9 is clamped with a pull rod 11 through the clamping block 10. A groove is provided at one end of the pull rod 11, and a pull rod box 5 is provided at the other end of the pull rod 11. During the test, the clamping block 10 can be embedded in the groove, and finally the sample box 9 is connected to the pull rod 11. When the sample box 9 is on the leftmost side, the pull rod 11 is in the sliding track 3. During the test, the steel needle 22 does not move, and the pull rod box 5 is pulled to move the sample box 9 left and right through the pull rod 11 for testing.

[0027] As a preferred solution, Figure 1 and Figure 3 As shown, one end of the sliding track 3 is provided with a first limiter 6, and the other end of the sliding track 3 is provided with a second limiter 7. The first limiter 6 and the second limiter 7 are electrically connected to a controller, and the controller is electrically connected to the motor. During the movement of the sample box 9 on the sliding track 3, when the sample box 9 contacts the first limiter 6 or the second limiter 7, the controller controls the motor to stop. By providing the first limiter 6 and the second limiter 7, when the motor of the driving mechanism drives the sample box 9 to reciprocate on the sliding track 3, when the sample box 9 contacts the first limiter 6 or the second limiter 7, the controller controls the motor to stop, thereby preventing the sample box 9 from moving beyond the limit and ensuring the normal operation of the entire experimental device.

[0028] As a preferred solution, Figure 1 and Figure 3As shown, the drill system includes a lifting mechanism 19 and a steel needle 22. The lifting mechanism 19 is connected to the reaction frame 2. The lifting mechanism 19 is connected to a chuck 21. The steel needle 22 is clamped on the chuck 21. The lifting mechanism 19 is used to drive the steel needle 22 to move in the vertical direction. When the drill system scratches the upper surface of the rock sample 15, the lifting mechanism 19 drives the chuck 21 to rise and fall, thereby driving the height of the steel needle 22 until the steel needle 22 is pressed against the upper surface of the rock sample 15. At this time, when the sample box 9 moves relative to the steel needle 22, the steel needle 22 can scratch the upper surface of the rock sample 15 in the sample box 9.

[0029] As a preferred solution, Figure 3 As shown, a force sensor 20 is connected to the steel needle 22. The force sensor 20 is used to detect the real-time pressure value applied by the steel needle 22 to the rock sample 15. The force sensor 20 is electrically connected to a controller, which is electrically connected to the lifting mechanism 19. A pressure value is preset in the controller. When the real-time pressure value is equal to the preset pressure value, the controller controls the lifting mechanism 19 to stop the action. By providing the force sensor 20, when the lifting mechanism 19 drives the steel needle 22 to press against the upper surface of the rock sample 15, the force sensor 20 is used to detect the real-time pressure value applied by the steel needle 22 to the upper surface of the rock sample 15. When the real-time pressure value is equal to the preset pressure value, the controller controls the lifting mechanism 19 to stop the action, thereby ensuring the accuracy of the pressure applied by the steel needle 22 to the upper surface of the rock sample 15, thereby ensuring the accuracy of the test results.

[0030] As a preferred solution, Figure 2 As shown, the low temperature is transmitted close to the surface of the rock sample 15, and the low temperature pipeline 17 in the low temperature system passes through the outlet 16 on the sample box 9. The low temperature pipeline 17 is flexible and can move as the sample box 9 moves.

[0031] The present invention also provides a method for conducting a test using the low-temperature rock wear resistance test device, comprising the following steps: Cooling the rock sample 15 to a target temperature, i.e., a preset temperature, and then placing the rock sample 15 in the sample box 9; The sample box 9 carrying the rock sample 15 is placed under the drill head system, and then the drill head system is controlled to press on the upper surface of the rock sample 15 and apply a predetermined downward pressure to the upper surface of the rock sample 15; The temperature measurement system is used to detect the real-time temperature of the rock sample 15, and the controller controls the cooling system according to the real-time temperature of the rock sample 15 to keep the rock sample 15 at a preset temperature; The test box is then driven to move horizontally, so that the upper surface of the rock sample 15 is scratched by the drill system. By detecting the depth of the scratch on the upper surface of the rock sample 15, the wear resistance of the rock sample 15 at low temperature is determined.

[0032] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A low-temperature rock wear resistance test device, comprising a reaction frame (2) and a drill system, wherein the drill system is arranged on the reaction frame (2) and is used to scratch a test rock sample (15), characterized in that: Also includes: A sample box (9) is provided below the drill head system, and the sample box (9) is used to hold a rock sample (15); A cooling system comprising a refrigeration device, a cryogenic pipeline (17) and a cryogenic guide (18), wherein the refrigeration device is in communication with the cryogenic pipeline (17), the cryogenic pipeline (17) is in communication with the cryogenic guide (18), the cryogenic guide (18) is disposed in the sample box (9), and the cryogenic guide (18) is in contact with the rock sample (15); A temperature measurement system is provided in the sample box (9), and the temperature measurement system is used to detect the real-time temperature of the rock sample (15); A controller is electrically connected to the cooling system and the temperature measuring system. A temperature is preset in the controller. The controller compares the real-time temperature with the preset temperature to control the operation of the cooling system so that the real-time temperature of the rock sample (15) is equal to the preset temperature.

2. The low-temperature rock wear resistance testing device according to claim 1, characterized in that: The cooling system comprises two low-temperature guide heads (18), both of which are connected to the low-temperature guide head (18), and the two low-temperature guide heads (18) are respectively attached to both sides of the rock sample (15).

3. The low-temperature rock wear resistance testing device according to claim 1, characterized in that: The temperature measuring system comprises two groups of temperature measuring plates (4), both of which are electrically connected to the controller. One group of temperature measuring plates (4) is arranged on the surface of the low-temperature guide head (18), and the other group of temperature measuring plates (4) is arranged on one side of the upper surface of the rock sample (15) where the area to be inscribed is to be inscribed.

4. The low-temperature rock wear resistance testing device according to claim 1, characterized in that: A slide rail system is provided below the reaction frame (2), the slide rail system comprising a slide rail (3) and a driving mechanism, the slide rail (3) being provided below the drill bit system, the length direction of the slide rail (3) being parallel to the upper surface of the rock sample (15), the driving mechanism being connected to the slide rail system, the sample box (9) being connected to the driving mechanism, and the driving mechanism being used to drive the sample box (9) to slide on the slide rail (3) along the length direction of the slide rail (3).

5. The low-temperature rock wear resistance testing device according to claim 1, characterized in that: The sliding rail (3) and the motor are fixed on the base (1); a clamping block (10) is welded to the bottom of the sample box (9); and the sample box (9) is clamped with a pull rod (11) through the clamping block (10).

6. The low-temperature rock wear resistance testing device according to claim 5, characterized in that: A first stopper (6) is provided at one end of the sliding track (3), and a second stopper (7) is provided at the other end of the sliding track (3). The first stopper (6) and the second stopper (7) are electrically connected to a controller, and the controller is electrically connected to the motor. When the sample box (9) moves on the sliding track (3), when the sample box (9) contacts the first stopper (6) or the second stopper (7), the controller controls the motor to stop.

7. The low-temperature rock wear resistance testing device according to claim 1, characterized in that: The drill system comprises a lifting mechanism (19) and a steel needle (22), wherein the lifting mechanism (19) is connected to the reaction frame (2), the lifting mechanism (19) is connected to a chuck (21), the steel needle (22) is clamped on the chuck (21), and the lifting mechanism (19) is used to drive the steel needle (22) to move in a vertical direction.

8. The low-temperature rock wear resistance testing device according to claim 7, characterized in that: The steel needle (22) is connected to a force sensor (20), and the force sensor (20) is used to detect the real-time pressure value applied by the steel needle (22) to the rock sample (15). The force sensor (20) is electrically connected to a controller, and the controller is electrically connected to the lifting mechanism (19). A pressure value is preset in the controller. When the real-time pressure value is equal to the preset pressure value, the controller controls the lifting mechanism (19) to stop the action.

9. A method for conducting a test using the low-temperature rock wear resistance test device according to claim 1, characterized in that: The following steps are involved: Cooling the rock sample (15) to a target temperature, i.e., a preset temperature, and then placing the rock sample (15) in a sample box (9); Placing a sample box (9) containing a rock sample (15) below a drill head system, and then controlling the movement of the drill head system to press the upper surface of the rock sample (15) with the drill head system and apply a predetermined downward pressure to the upper surface of the rock sample (15); The temperature measurement system is used to detect the real-time temperature of the rock sample (15), and the controller controls the operation of the cooling system according to the real-time temperature of the rock sample (15) so as to keep the rock sample (15) at a preset temperature; Then, the test box is driven to move in a horizontal direction, so that the upper surface of the rock sample (15) is scratched by the drill system, and the wear resistance of the rock sample (15) at low temperature is known by detecting the depth of the scratch on the upper surface of the rock sample (15).

Images