Rock coring device for geotechnical engineering investigation

Abstract

The application provides a rock coring device for geotechnical engineering investigation, and belongs to the field of geotechnical exploration equipment. The rock coring device for geotechnical engineering investigation comprises a drilling cylinder, a cutting part and a sampling cylinder. During drilling, the cutting part is at a working angle, and the reaction force of the cutting edge pushes the cutting part to deflect inward, and the partial limitation of the sampling cylinder to the inward deflection of the cutting part enables the cutting part to be positioned at the working angle; after the sampling cylinder is filled with samples, the sampling cylinder can move axially relative to the drilling cylinder before sampling to release the limitation on the cutting part, and then the cutting part is pushed by the reaction force to deflect inward and cut the root of the sample, thereby weakening the root of the sample, and when the coring device is lifted, the sample is more likely to be broken from the root, the sample is prevented from falling off, and the continuity of the sample is ensured.

Description

Technical Field

[0001] This application belongs to the technical field of geotechnical exploration equipment, and more specifically, relates to a rock core sampling device for geotechnical engineering exploration. Background Technology

[0002] In geotechnical engineering, rock core sampling refers to the process of obtaining rock core samples from underground rock strata using specialized equipment. The extracted rock core samples are used to determine various physical and chemical properties of the rock.

[0003] Currently, rock coring involves drilling with a drill bit equipped with a sampling tube. As the drill bit penetrates deeper into the rock strata, the rock core enters the sampling tube. After the drill bit is withdrawn, the rock core sample can be retrieved from the sampling tube. This process is repeated multiple times to obtain continuous rock core samples.

[0004] However, in actual construction, each time the drill bit is withdrawn, it cannot completely remove the rock core that has entered the sampling tube, and a small portion will always remain in the borehole. When the drill bit is lowered again to continue sampling, it is easy for the drill bit to destroy this remaining part of the rock core, resulting in a missing part of the rock core sample between the two samplings, which affects the sampling quality. Summary of the Invention

[0005] In view of this, the present application provides a rock core sampling device for geotechnical engineering investigation to solve the technical problem that some samples are easily left behind when the sampling drill bit is withdrawn from the borehole in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] On the one hand, a rock core sampling device for geotechnical engineering investigation is provided, comprising:

[0008] Drilling tube;

[0009] The cutting section is rotatably disposed on the side wall at the front end of the drilling barrel; when the cutting section is at the working angle, the cutting edge of the cutting section is tilted outward so that the cutting edge generates an inward reaction force when cutting; the cutting section can rotate inward from the working angle;

[0010] The sampling tube is fitted inside the drilling tube and is axially movable relative to the drilling tube;

[0011] During drilling, the cutting part is at the working angle, and the reaction force of the cutting edge pushes the cutting part to deflect inward. The sampling cylinder partially limits the inward deflection of the cutting part so that the cutting part is positioned at the working angle.

[0012] Before sampling, the sampling cylinder can be moved axially relative to the drilling cylinder to release the restriction on the cutting part, thereby causing the cutting part to be pushed inward by the reaction force and cut the root of the sample.

[0013] In some embodiments, when the cutting part is at the working angle, the cutting edge of the cutting part extends to the front of the front end sidewall of the sampling cylinder in the radial direction of the drilling cylinder, and is supported and limited by the front end sidewall of the sampling cylinder.

[0014] The sampling cylinder can move backward relative to the drilling cylinder to release the restriction on the cutting part.

[0015] In some embodiments, the cutting part is provided with a right-angle notch, the side wall of the front end of the sampling tube is embedded in the right-angle notch, and the front end face and outer side face of the sampling tube respectively abut against the wall surface of the adjacent right-angle notch.

[0016] In some embodiments, the rock core sampling device for geotechnical engineering investigation further includes a triggering mechanism;

[0017] The rear end of the drilling tube is closed by a rear end cap; a sealing fit is formed between the rear end of the sampling tube and the rear end of the drilling tube;

[0018] The triggering mechanism includes:

[0019] A trigger plate is axially slidably disposed inside the sampling cylinder; the trigger plate is sealed to the inner wall of the sampling cylinder to seal the rear end of the drilling cylinder to form a pressure chamber; the rear end cover is provided with a water inlet hole communicating with the pressure chamber;

[0020] A radial slider is slidably disposed on the rear end cover to switch between a support position and a clearance position; the rear end cover is provided with a piston chamber communicating with the water inlet hole, one end of the radial slider forms a piston structure and is inserted into the piston chamber, and is adapted to switch to the support position under the push of the water flow in the piston chamber;

[0021] A first self-locking wedge mechanism is used, wherein the trigger plate drives the radial slider to switch to the avoidance position through the first self-locking wedge mechanism;

[0022] The second self-locking wedge mechanism drives the sampling cylinder to limit the cutting part through the second self-locking wedge mechanism;

[0023] After the water in the inlet reaches the predetermined water pressure, the water flow in the pressure chamber pushes the trigger plate forward, so that the first self-locking wedge mechanism releases the locking of the radial slider in the avoidance position, and then the water flow in the inlet pushes the radial slider to switch to the support position. The second self-locking wedge mechanism drives the sampling cylinder to move forward and maintains the forward support of the sampling cylinder through self-locking.

[0024] When the trigger plate moves backward, the trigger plate drives the radial slider to switch to the avoidance position through the first self-locking wedge mechanism, and the second self-locking wedge mechanism releases the forward support of the sampling cylinder.

[0025] In some embodiments, the rear end cover is provided with a radial sliding groove, and the radial slider is slidably disposed within the sliding groove;

[0026] One end of the sliding groove is connected to the water inlet through the piston chamber, and the other end is provided with a pressure relief hole that communicates with the outside. The groove opening of the sliding groove is connected to the pressure chamber, and the radial slider is connected to the first self-locking wedge mechanism through the groove opening of the sliding groove.

[0027] In some embodiments, the first self-locking wedge mechanism includes:

[0028] The first inclined surface is provided on the radial slider and is inclined away from the piston cavity;

[0029] The first wedge has an inclined surface that slides and fits against the first inclined surface, and is located on the side of the trigger plate facing the pressure chamber.

[0030] In some embodiments, the second self-locking wedge mechanism includes:

[0031] The second wedge is disposed on the radial slider and has an inclined surface that is inclined away from the piston cavity;

[0032] The rear end face of the sampling cylinder sidewall forms a second inclined surface that slides and fits against the inclined surface of the second wedge.

[0033] In some embodiments, the angle between the mating inclined surface of the first self-locking wedge mechanism and the axis of the drill barrel is less than or equal to 30°;

[0034] The angle between the mating inclined surface of the second self-locking wedge mechanism and the axis of the drilling barrel is greater than or equal to 60°.

[0035] In some embodiments, the rock core sampling device for geotechnical engineering investigation further includes a drainage mechanism; the drainage mechanism includes:

[0036] The connecting pipe has a drain port on the side, and one end is connected to the water inlet hole;

[0037] A sealing sleeve is fitted over the connecting pipe; it moves forward to close the drain port and moves backward to open the drain port.

[0038] A limiting structure is further provided between the rear end cover and the trigger plate; the limiting structure includes:

[0039] The connecting rod has one end detachably connected to the trigger plate, and the other end passes through the rear end cover via a through hole and is connected to the sealing sleeve.

[0040] The trigger plate moves forward, causing the sealing sleeve to close the outlet; the trigger plate moves backward, causing the sealing sleeve to avoid the outlet.

[0041] In some embodiments, an ear sleeve is provided on the outside of the closed sleeve, one end of the connecting rod is threaded to the ear sleeve, and the other end is threaded to the trigger plate, with the threads at both ends of the connecting rod having opposite directions.

[0042] The beneficial effects of the rock core sampling device for geotechnical engineering exploration provided in this application embodiment are as follows: Compared with the prior art, the rock core sampling device for geotechnical engineering exploration in this application embodiment, during drilling, partially limits the inward deflection of the cutting part by the sampling tube, so that the cutting part is positioned and smooth drilling is achieved; after the sampling tube is filled with sample, the sampling tube is moved axially relative to the drilling tube, the limitation on the cutting part is released, so that the cutting part is pushed inward by the reaction force and cuts the root of the sample, thereby weakening the root of the sample. When the core sampling device is lifted, the sample is more likely to break off from the root, avoiding sample drop and ensuring the continuity of the sample. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a cross-sectional structural schematic diagram of a rock core sampling device for geotechnical engineering investigation provided in an embodiment of this application. In the figure, the radial slider is in the support position and the cutting part is in the working angle.

[0045] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0046] Figure 3 This is a cross-sectional view of the lower end of the rock core sampling device for geotechnical engineering investigation provided in an embodiment of this application. In the figure, the cutting part is in an inwardly deflected state.

[0047] Figure 4 for Figure 3 A cross-sectional view of the upper end of a rock core sampling device used in geotechnical engineering investigation. In the figure, the radial slider is in the avoidance position.

[0048] Figure 5 A cross-sectional view of the connecting pipe portion of the rock core sampling device for geotechnical engineering investigation provided in the embodiments of this application.

[0049] The following are the labeling elements in the figure:

[0050] 1-Drilling barrel; 11-Rear end cap; 12-Water inlet; 13-Sliding groove; 14-Pressure chamber; 15-Piston chamber; 16-Pressure relief hole; 2-Cutting part; 21-Cutting edge; 22-Right angle notch; 3-Sampling cylinder; 4-Triggering mechanism; 41-Trigger plate; 42-Radial slider; 43-First self-locking wedge mechanism; 431-First inclined plane; 432-First wedge; 44-Second self-locking wedge mechanism; 441-Second wedge; 442-Second inclined plane; 5-Drainage mechanism; 51-Connecting pipe; 511-Drainage port; 52-Sealing sleeve; 521-Ear sleeve; 6-Connecting rod. Detailed Implementation

[0051] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0052] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0053] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0055] Please refer to the following: Figures 1 to 5 The rock core sampling device for geotechnical engineering investigation provided in the embodiments of this application will now be described. A rock core sampling device for geotechnical engineering investigation includes:

[0056] Drilling tube;

[0057] The cutting section is rotatably located on the side wall at the front end of the drill barrel; when the cutting section is at the working angle, the cutting edge of the cutting section is tilted outward so that the cutting edge generates an inward reaction force when cutting; the cutting section can rotate inward from the working angle;

[0058] The sampling tube is fitted inside the drilling tube and can move axially relative to the drilling tube;

[0059] During drilling, the cutting part is at the working angle. The reaction force of the cutting edge pushes the cutting part to deflect inward. The sampling cylinder locally limits the inward deflection of the cutting part so that the cutting part is positioned at the working angle.

[0060] Before sampling, the sampling tube can move axially relative to the drilling tube to release the restriction on the cutting part, thereby causing the cutting part to be pushed inward by the reaction force and cut the root of the sample.

[0061] Compared with the prior art, the rock core sampling device for geotechnical engineering investigation in this application embodiment deflects the cutting part of the sampling tube inward during drilling, positioning the cutting part and achieving smooth drilling. After the sampling tube is filled with sample, the sampling tube is moved axially relative to the drilling tube to release the restriction on the cutting part. This causes the cutting part to be pushed inward by the reaction force and cut the root of the sample, thereby weakening the root of the sample. When the core sampling device is lifted, the sample is more likely to break off from the root, avoiding sample loss and ensuring sample continuity.

[0062] In this embodiment, the drilling tube is cylindrical, and a cutting section is provided at its front end (the lower end in the figure), which is mainly used for drilling.

[0063] The cutting edge is rotatably positioned at the front end of the drill barrel, allowing it to deflect inwards or outwards to a certain extent. It should be noted that inward deflection refers to the cutting edge moving closer to the axis of the drill barrel, while outward deflection refers to the cutting edge moving away from the axis of the drill barrel.

[0064] The sampling tube is also cylindrical, with a smaller diameter than the drilling tube, and is coaxially fitted inside the drilling tube. The sampling tube can move forward (downward in the figure) or backward (upward in the figure) relative to the drilling tube.

[0065] The cutting section is rotatably located at the front end of the drill barrel. The working angle of the cutting section, which is the angle at which the cutting edge can perform normal cutting and allow the rock core sampling device used for geotechnical engineering exploration to drill normally, can be referenced from the cutting edge angle settings of existing drill bit equipment. The working angle can be a fixed angle or an angle range.

[0066] During drilling, the cutting part is at the working angle. The reaction force of the rock being cut on the cutting edge pushes the cutting part to tend to deflect inward. In order to avoid the cutting part deflecting inward and affecting the sample entering the sampling tube and to ensure normal drilling, the inward deflection of the cutting part is locally limited by the sampling tube so that the cutting part is positioned at the working angle.

[0067] Once the sampling tube is filled with sample, control the axial movement of the sampling tube relative to the drilling tube to release the restriction on the cutting part. Then, keep the core sampling device rotating at a low speed, stop drilling or advance slightly to a certain depth, so that the cutting part, which is no longer restricted, deflects inward under the reaction force of cutting the rock, thereby forming a certain degree of cutting on the root of the sample and weakening the root of the sample. Then, when the core sampling device is lifted, the sample is more likely to break off from the root, avoiding sample detachment and ensuring the continuity of the sample.

[0068] The axial movement of the sampling tube can be achieved by a hydraulic or electric actuation mechanism located between the drilling tube and the sampling tube.

[0069] Please see Figure 1 and 3 As a specific embodiment of the rock core sampling device for geotechnical engineering exploration provided in this application, when the cutting part is at the working angle, the cutting edge of the cutting part extends to the front of the front side wall of the sampling tube in the radial direction of the drilling tube and is supported and limited by the front side wall of the sampling tube.

[0070] The sampling tube can be moved backward relative to the drilling tube to release the restriction on the cutting part.

[0071] In this embodiment, the cutting edge of the cutting section can cut the rock in front of the sampling cylinder, reducing drilling resistance. The front sidewall of the sampling cylinder is supported behind the cutting edge, thereby limiting the inward deflection of the cutting section and positioning it at the working angle. Moving the sampling cylinder backward relative to the drilling cylinder releases the limitation on the cutting section.

[0072] Please see Figure 1 and 3As a specific embodiment of the rock core sampling device for geotechnical engineering exploration provided in this application, the cutting part is provided with a right-angle notch in a certain part, the side wall of the front end of the sampling tube is embedded in the right-angle notch, and the front end face and the outer side face of the sampling tube respectively abut against the wall surface of their respective adjacent right-angle notches.

[0073] In this embodiment, the side wall at the front end of the sampling cylinder can limit the cutting part in both inward and outward directions, so that the cutting part can be positioned at a fixed working angle and the cutting part can be prevented from moving around randomly.

[0074] In practice, a right-angle notch is formed behind the end of the cutting edge of the cutting part that is close to the axis of the drilling tube. The front end face of the sampling tube abuts against the wall behind the right-angle notch, and the outer peripheral surface of the sampling tube abuts against the other wall of the right-angle notch.

[0075] Please see Figure 1 , 2 4. As a specific embodiment of the rock core sampling device for geotechnical engineering exploration provided in this application, the rock core sampling device for geotechnical engineering exploration also includes a triggering mechanism.

[0076] The rear end of the drilling tube is sealed by a rear end cap; a sealing fit is formed between the rear end of the sampling tube and the rear end of the drilling tube;

[0077] The triggering mechanism includes:

[0078] A trigger plate is axially slidably disposed inside the sampling tube; the trigger plate is sealed to the inner wall of the sampling tube to seal the rear end of the drilling tube to form a pressure chamber; the rear end cover is provided with a water inlet hole communicating with the pressure chamber;

[0079] A radial slider is slidably disposed on the rear end cover to switch between a support position and a clearance position; the rear end cover is provided with a piston chamber communicating with the water inlet, one end of the radial slider forms a piston structure and is inserted into the piston chamber, and is adapted to switch to the support position under the push of the water flow in the piston chamber;

[0080] The first self-locking wedge mechanism drives the radial slider to switch to the avoidance position via the trigger plate.

[0081] The second self-locking wedge mechanism drives the sampling cylinder limiting cutting part through the radial slider.

[0082] After the water in the inlet reaches the predetermined water pressure, the water flow in the pressure chamber pushes the trigger plate forward, so that the first self-locking wedge mechanism releases the locking of the radial slider in the avoidance position, and then the water flow in the inlet pushes the radial slider to switch to the support position. The second self-locking wedge mechanism drives the sampling cylinder to move forward and supports the sampling cylinder forward by self-locking.

[0083] When the trigger plate moves backward, the trigger plate drives the radial slider to switch to the avoidance position through the first self-locking wedge mechanism, and the second self-locking wedge mechanism releases the forward support of the sampling cylinder.

[0084] In this embodiment, when sampling is performed, once the sampling tube is full of sample, the sampling tube can be automatically driven to move axially through a triggering mechanism to collect the sample without manual operation.

[0085] The rear end of the drilling tube is sealed by a rear end cap, forming a sealed fit between the rear end of the sampling tube and the rear end of the drilling tube. The sampling tube remains sealed even as it slides back and forth relative to the drilling tube. This design ensures that the rear end of the drilling tube has only one channel: the inner cavity of the sampling tube. Specifically, a sealing ring is provided on the outer periphery of the rear end of the sampling tube to seal against the inner wall of the rear end of the drilling tube.

[0086] The trigger plate slides and seals against the inner wall of the sampling tube, sealing the rear end of the drilling tube to form a pressure chamber. The trigger plate can slide back and forth. When water (drilling fluid) enters the pressure chamber through the inlet, it pushes the trigger plate forward (downward in the figure). Specifically, a sealing ring is provided on the outer circumference of the circular trigger plate to achieve a sliding seal with the inner wall of the sampling tube.

[0087] The radial slider is reciprocated between the support position and the avoidance position, and one end of it is inserted into the piston chamber that communicates with the water inlet. When water (drilling fluid) enters the piston chamber through the water inlet, it will push the radial slider to slide to the support position.

[0088] The trigger plate drives the radial slider through the first self-locking wedge mechanism, and conversely, the first self-locking wedge mechanism self-locks, so that the radial slider will not exert a forward (downward) thrust on the trigger plate under the push of the water flow in the piston chamber, thus avoiding pushing out the collected sample.

[0089] The radial slider drives the sampling cylinder through the second self-locking wedge mechanism, and conversely, the second self-locking wedge mechanism self-locks to prevent the sampling cylinder from being pushed back (upward in the figure) by external pressure during drilling, so that the sampling cylinder can support the cutting part.

[0090] In use, the drilling fluid pipe is connected to the water inlet. The drilling fluid enters the pressure chamber and piston chamber through the water inlet, forming a certain pressure in the pressure chamber and piston chamber respectively. The pressure in the pressure chamber causes the trigger plate to move downward, releasing the self-locking of the first self-locking wedge mechanism on the radial slider. Meanwhile, the radial slider in the piston chamber is pushed to switch to the support position. The radial slider drives the sampling cylinder to limit the cutting part through the second self-locking wedge mechanism. Afterwards, normal drilling and sampling begins. As the core sampling device drills in, once the sample fills the sampling cylinder, the sample begins to push the trigger plate backward (upward in the figure), causing the trigger plate to move backward (upward in the figure). Through the first self-locking wedge mechanism, it pushes the radial slider to overcome the pressure in the piston chamber and slide to the avoidance position. At the same time, the radial slider slides to the avoidance position, which drives the second self-locking wedge mechanism to release the limit on the sampling cylinder, so that the sampling cylinder can no longer limit the cutting part. Then, under the action of external pressure, the cutting part deflects inward. As the core sampling device continues to rotate, the inwardly deflected cutting part cuts the outer periphery of the sample root, making it easier for the sample to break off from the root when the core sampling device is lifted, avoiding sample detachment and ensuring sample continuity.

[0091] Please see Figure 2 and 4 As a specific embodiment of the rock core sampling device for geotechnical engineering exploration provided in this application, the rear end cover is provided with a radial sliding groove, and the radial slider is slidably disposed in the sliding groove.

[0092] One end of the sliding groove is connected to the water inlet through the piston chamber, and the other end is provided with a pressure relief hole that communicates with the outside. The groove opening of the sliding groove is connected to the pressure chamber, and the radial slider is connected to the first self-locking wedge mechanism through the groove opening of the sliding groove.

[0093] In this embodiment, the opening of the sliding groove is connected to the pressure chamber, facilitating the connection between the radial slider and the first and second self-locking wedge mechanisms. By providing a pressure relief hole at one end of the sliding groove, the drilling fluid entering the sliding groove is prevented from creating resistance at the end of the radial slider.

[0094] In practical implementation, the rear end cover is circular, and the sliding groove is arranged radially along the rear end cover. When the radial slider is located at the radially outward end of the sliding groove, it is in a supporting position; when the radial slider is located at the radially inward end of the sliding groove, it is in a clearance position.

[0095] Please see Figure 2 and 4 As a specific embodiment of the rock core sampling device for geotechnical engineering investigation provided in this application, the first self-locking wedge mechanism includes:

[0096] The first inclined surface is located on the radial slider and is inclined away from the piston cavity;

[0097] The first wedge has an inclined surface that slides and fits against the first inclined surface, and is located on the side of the trigger plate facing the pressure chamber.

[0098] In a specific implementation, the radial slider has a protrusion facing the trigger plate, and the side of the protrusion facing away from the piston cavity forms a first inclined surface. The first wedge of the trigger plate faces the radial slider, and the inclined surface of the first wedge slides in contact with the first inclined surface.

[0099] Please see Figure 2 and 4 As a specific embodiment of the rock core sampling device for geotechnical engineering investigation provided in this application, the second self-locking wedge mechanism includes:

[0100] The second wedge is located on the radial slider and has an inclined surface that is inclined away from the piston cavity;

[0101] The rear end face of the sampling cylinder sidewall forms a second inclined surface that slides and fits against the inclined surface of the second wedge.

[0102] In a specific implementation, the radial slider has a protrusion facing the sidewall of the sampling cylinder, and the side of the protrusion facing away from the piston chamber forms a second inclined surface. The rear end of the sampling cylinder sidewall faces the radial slider, and the rear end face is inclined and slides in contact with the second inclined surface.

[0103] Please see Figure 2 and 4 As a specific embodiment of the rock core sampling device for geotechnical engineering exploration provided in this application, the angle between the mating inclined surface of the first self-locking wedge mechanism and the axis of the drilling cylinder is less than or equal to 30°.

[0104] The angle between the mating inclined surface of the second self-locking wedge mechanism and the axis of the drilling barrel is greater than or equal to 60°.

[0105] In this embodiment, self-locking is achieved by the angle of the mating inclined surfaces of the first and second self-locking wedge mechanisms. The mating inclined surface is also the inclined surface of the wedge block of the wedge mechanism.

[0106] Please see Figure 1 and 5 As a specific embodiment of the rock core sampling device for geotechnical engineering investigation provided in this application, the rock core sampling device for geotechnical engineering investigation further includes a discharge mechanism; the discharge mechanism includes:

[0107] The connecting pipe has a drain port on the side, and one end is connected to the water inlet.

[0108] A sealing sleeve is fitted over the connecting pipe; moving it forward closes the drain outlet, and moving it backward opens the drain outlet.

[0109] A limiting structure is also provided between the rear cover and the trigger plate; the limiting structure includes:

[0110] The connecting rod has one end detachably connected to the trigger plate, and the other end passes through the through hole, passes through the rear end cover, and is connected to the sealing sleeve.

[0111] The trigger plate moves forward, causing the sealing sleeve to close the outlet; the trigger plate moves backward, causing the sealing sleeve to avoid the outlet.

[0112] In this embodiment, the limiting structure is used to restrict the forward (downward in the figure) movement distance of the trigger plate, preventing the trigger plate from detaching from the sampling cylinder. The venting mechanism is linked with the limiting structure. When the sampling cylinder is filled with sample, the trigger plate drives the sealing sleeve to move backward (upward in the figure) through the connecting rod, thereby opening the vent. After sampling is completed, the drilling fluid can flow out from the vent, releasing the pressure in the pressure chamber. This relieves the pressure of the drilling fluid in the pressure chamber on the trigger plate, preventing the sample in the sampling cylinder from being pushed out.

[0113] In practice, the connecting pipe is fixed at the center of the rear end cap. The connecting pipe has threads on its exterior for connection to the drill pipe of the drilling rig. The connecting pipe serves both power transmission and drilling fluid introduction. Inclined reinforcing ribs can also be provided between the outer periphery of the connecting pipe and the rear end cap to increase the connection strength. Alternatively, the connecting pipe can be fixed at an eccentric position on the rear end cap, solely for drilling fluid introduction, while other connectors are located at the center of the rear end cap for power transmission to the drill pipe.

[0114] The sealing sleeve fits over the connecting pipe and can slide back and forth. The sealing sleeve does not need to be perfectly tight around the drain port, allowing a small amount of drilling fluid to leak out, but sufficient pressure should be maintained in the pressure chamber. The small amount of drilling fluid leaking from the drain port can help cool the rear of the coring unit.

[0115] The trigger plate is connected to the sealing sleeve via a connecting rod. On the one hand, when the trigger plate moves backward (upward in the figure), it can push the sealing sleeve backward (upward in the figure) to open the vent. On the other hand, when the trigger plate moves backward and forward (downward in the figure), it can also cause the sealing sleeve to close the vent, and be limited by the sealing sleeve.

[0116] When it is necessary to remove the sample, the connecting rod is detached from the trigger plate, and the trigger plate can then move forward (downward in the figure) to push the sample out. Specifically, after removing the connecting rod, a long rod is inserted through the through hole on the rear end cover to push the trigger plate forward (downward in the figure).

[0117] Specifically, the connecting rod and the through hole on the rear end cover should fit tightly to form a certain sealing effect and ensure the pressure in the pressure chamber.

[0118] Please see Figure 5 As a specific embodiment of the rock core sampling device for geotechnical engineering exploration provided in this application, the outer side of the closed sleeve is provided with an ear sleeve, one end of the connecting rod is threadedly connected to the ear sleeve, and the other end is threadedly connected to the trigger plate, with the threads at both ends of the connecting rod having opposite directions.

[0119] In this embodiment, the distance between the sealing sleeve and the trigger plate can be adjusted or the two can be separated by rotating the connecting rod.

[0120] In practice, two, three, or four ear tips can be evenly distributed around the outer periphery of the closed sleeve. Each ear tip is equipped with a connecting rod, and the two ends of each connecting rod are connected to the trigger plate and the corresponding ear tip, respectively.

[0121] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A rock core sampling device for geotechnical engineering investigation, characterized in that, include: Drilling tube; The cutting section is rotatably located on the side wall at the front end of the drilling barrel; When the cutting part is at the working angle, the cutting edge of the cutting part is tilted outward so that the cutting edge generates an inward reaction force when cutting; the cutting part can rotate inward from the working angle; The sampling tube is fitted inside the drilling tube and is axially movable relative to the drilling tube; During drilling, the cutting part is at the working angle, and the reaction force of the cutting edge pushes the cutting part to deflect inward. The sampling cylinder partially limits the inward deflection of the cutting part so that the cutting part is positioned at the working angle. Before sampling, the sampling cylinder can move axially relative to the drilling cylinder to release the restriction on the cutting part, thereby causing the cutting part to be pushed inward by the reaction force and cut the root of the sample; When the cutting part is at the working angle, in the radial direction of the drilling barrel, the cutting edge of the cutting part extends to the front of the front end side wall of the sampling barrel and is supported and limited by the front end side wall of the sampling barrel. The sampling cylinder can move backward relative to the drilling cylinder to release the restriction on the cutting part; The rock core sampling device for geotechnical engineering investigation also includes a triggering mechanism; The rear end of the drilling tube is closed by a rear end cap; a sealing fit is formed between the rear end of the sampling tube and the rear end of the drilling tube; The triggering mechanism includes: A trigger plate is axially slidably disposed inside the sampling cylinder; the trigger plate is sealed to the inner wall of the sampling cylinder to seal the rear end of the drilling cylinder to form a pressure chamber; the rear end cover is provided with a water inlet hole communicating with the pressure chamber; A radial slider is slidably disposed on the rear end cover to switch between a support position and a clearance position; the rear end cover is provided with a piston chamber communicating with the water inlet hole, one end of the radial slider forms a piston structure and is inserted into the piston chamber, and is adapted to switch to the support position under the push of the water flow in the piston chamber; A first self-locking wedge mechanism is used, wherein the trigger plate drives the radial slider to switch to the avoidance position through the first self-locking wedge mechanism; The second self-locking wedge mechanism drives the sampling cylinder to limit the cutting part through the second self-locking wedge mechanism; After the water in the inlet reaches the predetermined water pressure, the water flow in the pressure chamber pushes the trigger plate forward, so that the first self-locking wedge mechanism releases the locking of the radial slider in the avoidance position, and then the water flow in the inlet pushes the radial slider to switch to the support position. The second self-locking wedge mechanism drives the sampling cylinder to move forward and maintains the forward support of the sampling cylinder through self-locking. When the trigger plate moves backward, the trigger plate drives the radial slider to switch to the avoidance position through the first self-locking wedge mechanism, and the second self-locking wedge mechanism releases the forward support of the sampling cylinder; The rear end cover is provided with a radial sliding groove, and the radial slider is slidably disposed in the sliding groove; One end of the sliding groove is connected to the water inlet through the piston chamber, and the other end is provided with a pressure relief hole that communicates with the outside. The groove opening of the sliding groove is connected to the pressure chamber. The first self-locking wedge mechanism includes: The first inclined surface is provided on the radial slider and is inclined away from the piston cavity; The first wedge has an inclined surface that slides and fits against the first inclined surface, and is located on the side of the trigger plate facing the pressure chamber; The rock core sampling device for geotechnical engineering investigation further includes a discharge mechanism; the discharge mechanism includes: The connecting pipe has a drain port on the side, and one end is connected to the water inlet hole; A sealing sleeve is fitted over the connecting pipe; it moves forward to close the drain port and moves backward to open the drain port. A limiting structure is further provided between the rear end cover and the trigger plate; the limiting structure includes: The connecting rod has one end detachably connected to the trigger plate, and the other end passes through the rear end cover via a through hole and is connected to the sealing sleeve. The trigger plate moves forward, causing the sealing sleeve to close the outlet; the trigger plate moves backward, causing the sealing sleeve to avoid the outlet.

2. The rock core sampling device for geotechnical engineering investigation as described in claim 1, characterized in that, The cutting part is provided with a right-angle notch, the side wall of the front end of the sampling tube is embedded in the right-angle notch, and the front end face and outer side face of the sampling tube respectively abut against the wall surface of the adjacent right-angle notch.

3. The rock core sampling device for geotechnical engineering investigation as described in claim 1, characterized in that, The second self-locking wedge mechanism includes: The second wedge is disposed on the radial slider and has an inclined surface that is inclined away from the piston cavity; The rear end face of the sampling cylinder sidewall forms a second inclined surface that slides and fits against the inclined surface of the second wedge.

4. The rock core sampling device for geotechnical engineering investigation as described in claim 1, characterized in that, The angle between the mating inclined surface of the first self-locking wedge mechanism and the axis of the drill barrel is less than or equal to 30°; The angle between the mating inclined surface of the second self-locking wedge mechanism and the axis of the drilling barrel is greater than or equal to 60°.

5. The rock core sampling device for geotechnical engineering investigation as described in claim 1, characterized in that, The outer side of the closed sleeve is provided with an ear sleeve. One end of the connecting rod is threaded to the ear sleeve, and the other end is threaded to the trigger plate. The threads at both ends of the connecting rod are in opposite directions.

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