Rock coring device for geotechnical engineering investigation

Abstract

The invention 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 barrel, a cutting part and a sampling barrel. During drilling, the cutting part is at a working angle, the counter-acting force of the cutting edge pushes the cutting part to deflect inwards, and the sampling barrel locally limits the inward deflection of the cutting part, so that the cutting part is positioned at the working angle; after the sampling barrel is filled with samples and before sampling, the sampling barrel can axially move relative to the drilling barrel so as to relieve limiting of the cutting part, then the cutting part is pushed by counter-acting force to deflect inwards and cut the roots of the samples, the roots of the samples are weakened, when the coring device is lifted, the samples are easier to break from the roots, the samples are prevented from falling off, and the sampling efficiency is improved. And the continuity of the sample is ensured.

Description

Technical Field

[0001] The present application belongs to the technical field of geotechnical exploration equipment, and more specifically, relates to a rock coring device for geotechnical engineering investigation. Background Art

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

[0003] At present, rock coring is done by drilling with a drill bit equipped with a sampling tube. As the drill bit goes deeper into the rock layer, the core enters the sampling tube. After the drill bit is withdrawn, the core sample in the sampling tube can be taken out. By repeating this process many times, continuous core samples can be obtained.

[0004] However, in actual construction, each time the drill bit is withdrawn, it cannot completely bring out the core that has entered the sampling tube, and there will always be a small part left in the borehole; and when the drill bit is lowered again to continue sampling, the drill bit will easily destroy the remaining part of the core, resulting in the loss of some core samples between the two samplings, affecting the sampling quality. Summary of the Invention

[0005] In view of this, an embodiment of the present application provides a rock coring device for geotechnical engineering investigation to solve the technical problem in the prior art that part of the sample is easily left behind when the sampling drill bit exits the borehole.

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

[0007] In one aspect, a rock coring device for geotechnical engineering investigation is provided, comprising:

[0008] Drilling tube;

[0009] A cutting portion is rotatably provided on the side wall of the front end of the drilling tube; when the cutting portion is at a working angle, the cutting edge of the cutting portion is inclined outward so that the cutting edge forms an inward reaction force when cutting; the cutting portion is capable of rotating inward from the working angle;

[0010] A sampling barrel is sleeved in the drilling barrel and is capable of axially moving relative to the drilling barrel;

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

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

[0013] In some embodiments, when the cutting portion is at the working angle, in the radial direction of the drilling barrel, the cutting edge of the cutting portion extends to the front of the side wall of the front end of the sampling barrel and is supported and limited by the side wall of the front end of the sampling barrel;

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

[0015] In some embodiments, a right-angled notch is partially provided on the cutting portion, the side wall of the front end of the sampling tube is embedded in the right-angled notch, and the front end face and the outer side face of the sampling tube respectively abut against the wall faces of the adjacent right-angled notch.

[0016] In certain embodiments, the rock coring device for geotechnical engineering investigation further includes a trigger mechanism;

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

[0018] The trigger mechanism comprises:

[0019] A trigger plate is axially slidably disposed in the sampling barrel; the trigger plate is in sealing engagement with the inner wall of the sampling barrel to seal the rear end of the drilling barrel 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 provided on the rear end cover to switch between a support position and an avoidance position; the rear end cover is provided with a piston cavity communicated with the water inlet hole, one end of the radial slider forms a piston structure and is inserted into the piston cavity, and is adapted to switch to the support position under the push of water flow in the piston cavity;

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

[0022] a second self-locking wedge mechanism, wherein the radial slider drives the sampling tube to limit the cutting portion through the second self-locking wedge mechanism;

[0023] After the water in the water inlet hole reaches a 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 lock that keeps the radial slider in the avoidance position, and then the water flow in the water inlet hole pushes the radial slider to switch to the supporting position, and the second self-locking wedge mechanism drives the sampling barrel to move forward and maintains the forward support of the sampling barrel by 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 for the sampling cylinder.

[0025] In some embodiments, the rear end cover is provided with a radial sliding groove, and the radial sliding block is slidably arranged in the sliding groove;

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

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

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

[0029] The first wedge has an inclined surface that is slidably engaged with the first inclined surface and is disposed on a side of the trigger plate facing the pressure chamber.

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

[0031] A second wedge block is provided on the radial slider and has an inclined surface inclined away from the piston cavity;

[0032] The rear end surface of the side wall of the sampling tube forms a second inclined surface that is slidably engaged with the inclined surface of the second wedge block.

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

[0034] The included angle between the matching 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 coring device for geotechnical engineering investigation further includes a flow discharge mechanism; the flow discharge mechanism includes:

[0036] A connecting pipe, with a drain port provided on the side and one end connected to the water inlet;

[0037] A sealing sleeve is sleeved on the outside of the connecting pipe, 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 comprises:

[0039] A connecting rod, one end of which is detachably connected to the trigger plate, and the other end of which passes through the rear end cover through a through hole and is connected to the closing sleeve;

[0040] The trigger plate moves forward, driving the sealing sleeve to close the drain port; the trigger plate moves backward, driving the sealing sleeve to avoid the drain port.

[0041] In some embodiments, an earmuff is provided on the outside of the sealing sleeve, one end of the connecting rod is threadedly connected to the earmuff, and the other end is threadedly connected to the trigger plate, and the threads at both ends of the connecting rod have opposite directions.

[0042] The beneficial effect of the rock coring device for geotechnical engineering investigation provided by the embodiment of the present application is that: compared with the prior art, the rock coring device for geotechnical engineering investigation provided by the embodiment of the present application, during drilling, the local limiting position of the sampling barrel causes the inward deflection of the cutting portion, so that the cutting portion is positioned and smooth drilling is achieved; after the sampling barrel is filled with samples, the sampling barrel is moved axially relative to the drilling barrel to release the limiting position of the cutting portion, so that the cutting portion is pushed inward by the reaction force and cuts the root of the sample, thereby weakening the root of the sample. When the coring device is lifted, the sample is more easily broken from the root, avoiding the sample from falling off and ensuring the continuity of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 This is a schematic cross-sectional view of a rock coring device for geotechnical engineering investigation provided by an embodiment of the present application. In the figure, the radial slider is in a supporting position and the cutting portion is at a working angle;

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

[0046] Figure 3 A cross-sectional view of the lower end of a rock coring device for geotechnical engineering investigation provided in an embodiment of the present application, in which the cutting portion is in an inwardly deflected state;

[0047] Figure 4 for Figure 3 A cross-sectional view of the upper end of a rock coring device for geotechnical engineering investigations, showing the radial slider in the avoidance position;

[0048] Figure 5 A cross-sectional view of the connecting pipe portion of a rock coring device for geotechnical engineering investigation provided in an embodiment of the present application.

[0049] Among them, the reference numerals in the figures are:

[0050] 1-drilling tube; 11-rear end cover; 12-water inlet; 13-sliding groove; 14-pressure chamber; 15-piston chamber; 16-pressure relief hole; 2-cutting part; 21-cutting blade; 22-right-angle notch; 3-sampling tube; 4-trigger mechanism; 41-trigger plate; 42-radial slider; 43-first self-locking wedge mechanism; 431-first inclined plane; 432-first wedge block; 44-second self-locking wedge mechanism; 441-second wedge block; 442-second inclined plane; 5-drainage mechanism; 51-connecting pipe; 511-drainage port; 52-closing sleeve; 521-ear sleeve; 6-connecting rod. DETAILED DESCRIPTION

[0051] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0052] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0053] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" or "several" means two or more, unless otherwise specifically defined.

[0055] Please also refer to Figures 1 to 5 The rock coring device for geotechnical engineering investigation provided in the embodiment of the present application is now described. A rock coring device for geotechnical engineering investigation comprises:

[0056] Drilling tube;

[0057] The cutting part is rotatably arranged on the side wall of the front end of the drilling tube; when the cutting part is at a working angle, the cutting edge of the cutting part is tilted outward so that the cutting edge forms an inward reaction force when cutting; the cutting part can rotate inward from the working angle;

[0058] The sampling tube is sleeved in the drilling barrel and can move axially relative to the drilling barrel;

[0059] During drilling, the cutting part is at a working angle, and the reaction force of the cutting edge pushes the cutting part to deflect inwards. The local part of the sampling tube 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, so that the cutting part is pushed inward by the reaction force and cuts the root of the sample.

[0061] Compared with the prior art, the rock coring device for geotechnical engineering investigation in the embodiment of the present application, during drilling, the local limiting cutting portion of the sampling barrel deflects inward, so that the cutting portion is positioned and smooth drilling is achieved; after the sampling barrel is filled with samples, the sampling barrel is moved axially relative to the drilling barrel to release the limiting of the cutting portion, so that the cutting portion is pushed inward by the reaction force and cuts the root of the sample, thereby weakening the root of the sample. When the coring device is lifted, the sample is more likely to break from the root, avoiding the sample from falling off and ensuring the continuity of the sample.

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

[0063] The cutting portion is rotatably mounted on the front end of the drilling barrel so that it can be deflected inwardly or outwardly to a certain extent. It should be noted that inward deflection refers to the cutting edge being deflected closer to the axis of the drilling barrel, and outward deflection refers to the cutting edge being deflected away from the axis of the drilling barrel.

[0064] The sampling cylinder is also cylindrical, and the diameter of the sampling cylinder is smaller than that of the drilling cylinder, and the sampling cylinder is coaxially sleeved inside the drilling cylinder, and the sampling cylinder can move forward (downward in the figure) or backward (upward in the figure) relative to the drilling cylinder.

[0065] The cutting part is rotationally arranged at the front end of the drilling cylinder, and the working angle of the cutting part, that is, the angle at which the cutting edge can normally cut, is the angle at which the rock coring device for geotechnical investigation can normally drill, and the angle of the cutting edge of the existing drill equipment can be referred to for reference. The working angle can be a certain angle or an angle range.

[0066] During drilling, the cutting part is at the working angle, and the reaction force of the cut rock on the cutting edge pushes the cutting part to form a tendency of inward deflection. In order to avoid the inward deflection of the cutting part affecting the sample into the sampling cylinder and ensure normal drilling, the inward deflection of the cutting part is limited by the local part of the sampling cylinder to position the cutting part at the working angle.

[0067] When the sampling cylinder is filled with samples, the sampling cylinder is controlled to move axially relative to the drilling cylinder, the limiting of the cutting part is released, and then the coring device is kept rotating at a low speed, the drilling is stopped or slightly advances to a certain depth, so that the cutting part that loses the limiting deflects inward under the reaction force of cutting rock, thereby cutting the root of the sample to a certain extent, weakening the root of the sample, and then when the coring device is lifted, the sample is more likely to break from the root, avoiding the sample from falling off and ensuring the continuity of the sample.

[0068] The axial movement of the sampling cylinder can be achieved by a hydraulic or electric pushing mechanism arranged between the drilling cylinder and the sampling cylinder.

[0069] Please refer to Figure 1 and 3 as a specific embodiment of the rock coring device for geotechnical investigation provided in the present application, when the cutting part is at the working angle, in the radial direction of the drilling cylinder, the cutting edge of the cutting part extends to the front of the front side wall of the sampling cylinder and is limited and supported by the front side wall of the sampling cylinder.

[0070] The sampling cylinder can move backward relative to the drilling cylinder to release the limiting of the cutting part.

[0071] In the present embodiment, the cutting edge of the cutting part can cut the rock in front of the sampling cylinder, reduce the drilling resistance, and the front side wall of the sampling cylinder is supported behind the cutting edge, thereby limiting the inward deflection of the cutting part to position the cutting part at the working angle. The sampling cylinder can move backward relative to the drilling cylinder to release the limiting of the cutting part.

[0072] Please refer to Figure 1 and 3As a specific embodiment of the rock coring device for geotechnical engineering investigation provided in the application, a partial straight corner notch is arranged on the cutting part, the side wall of the front end of the sampling cylinder is embedded in the straight corner notch, and the front end face and the outer lateral face of the sampling cylinder are respectively abutted against the wall faces of the respective adjacent straight corner notches.

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

[0074] In the specific implementation, the cutting blade of the cutting part forms a straight corner notch at the rear of the end close to the axis of the drilling cylinder, the front end face of the sampling cylinder is abutted against the wall face of the straight corner notch at the rear of the cutting blade, and the outer peripheral face of the sampling cylinder is abutted against the other wall face of the straight corner notch.

[0075] Please refer to Figure 1 , 2 and 4, as a specific embodiment of the rock coring device for geotechnical engineering investigation provided in the application, the rock coring device for geotechnical engineering investigation further comprises a trigger mechanism.

[0076] The rear end of the drilling cylinder is closed by a rear end cover; and the rear end of the sampling cylinder is sealingly fitted with the rear end of the drilling cylinder;

[0077] The trigger mechanism comprises:

[0078] A trigger plate is axially slidably arranged in the sampling cylinder; the trigger plate is sealingly fitted with the inner wall of the sampling cylinder to close the rear end of the drilling cylinder to form a pressure cavity; and the rear end cover is provided with a water inlet hole in communication with the pressure cavity;

[0079] A radial slider is slidably arranged in the rear end cover to switch between a supporting position and a avoiding position; the rear end cover is provided with a piston cavity in communication with the water inlet hole, one end of the radial slider forms a piston structure and is inserted into the piston cavity, and is adapted to be switched to the supporting position under the pushing of water flow in the piston cavity;

[0080] A first self-locking wedge mechanism is used to drive the radial slider to switch to the avoiding position by the trigger plate;

[0081] A second self-locking wedge mechanism is used to drive the sampling cylinder to limit the cutting part by the radial slider;

[0082] When the water in the water inlet hole reaches a predetermined water pressure, the water flow in the pressure cavity pushes the trigger plate to move forward, so that the first self-locking wedge mechanism releases the locking of the radial slider in the avoiding position, and then the water flow in the water inlet hole pushes the radial slider to switch to the supporting position, and the second self-locking wedge mechanism drives the forward movement of the sampling cylinder and keeps supporting the forward movement of the sampling cylinder 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 for the sampling cylinder.

[0084] In this embodiment, when sampling is performed, after the sample fills the sampling tube, the trigger mechanism can automatically drive the sampling tube to move axially, thereby collecting the sample without manual operation.

[0085] The rear end of the drilling barrel is sealed by a rear end cap, forming a seal between the rear end of the sampling barrel and the rear end of the drilling barrel. This seal is maintained even when the sampling barrel slides back and forth relative to the drilling barrel. This arrangement ensures that the rear end of the drilling barrel has only one access point, the inner cavity of the sampling barrel. Specifically, a sealing ring is provided on the outer periphery of the rear end of the sampling barrel to seal against the rear end inner wall of the drilling barrel.

[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 water inlet, it pushes the trigger plate forward (downward in the figure). Specifically, a sealing ring is provided on the outer periphery of the circular trigger plate to achieve a sliding seal with the inner wall of the sampling tube.

[0087] The radial slider is set to slide back and forth between the support position and the avoidance position, and one end of the radial slider is inserted into the piston cavity connected to the water inlet hole. When water (drilling fluid) enters the piston cavity through the water inlet hole, it pushes 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 vice versa, the first self-locking wedge mechanism self-locks, so that the radial slider will not form a forward thrust (downward in the figure) on the trigger plate under the push of the water flow in the piston chamber, thereby avoiding pushing out the collected sample.

[0089] The radial slider drives the sampling barrel through the second self-locking wedge mechanism. Otherwise, the second self-locking wedge mechanism self-locks to prevent the sampling barrel from retreating backward (upward in the figure) due to external pressure during drilling, so that the sampling barrel can keep supporting the cutting part.

[0090] When in use, the drilling fluid pipe is connected to the water inlet hole, and the drilling fluid enters the pressure chamber and the piston chamber through the water inlet hole, forming a certain pressure in the pressure chamber and the piston chamber respectively. The pressure in the pressure chamber causes the trigger plate to move downward, unlocking the self-locking of the radial slider by the first self-locking wedge mechanism, and the radial slider in the piston chamber is pushed to switch to the supporting position, and the radial slider drives the sampling tube limiting cutting part through the second self-locking wedge mechanism. After that, normal drilling and sampling begins. As the coring device drills, when the sample fills the sampling tube, the sample begins to push the trigger plate backward (upward in the figure), causing the trigger plate to move backward (upward in the figure) and push the radial slider through the first self-locking wedge mechanism to overcome the pressure in the piston chamber and slide to the avoidance position. When the radial slider slides to the avoidance position, it drives the second self-locking wedge mechanism to release the limit on the sampling tube, so that the sampling tube cannot limit the cutting part, and then the cutting part deflects inward under the action of external pressure. As the coring device continues to rotate, the inwardly deflected cutting part cuts the outer periphery of the sample root, so that when the coring device is lifted, the sample is more likely to break from the root, avoiding the sample from falling off and ensuring the continuity of the sample.

[0091] See also Figure 2 and 4 As a specific embodiment of the rock coring device for geotechnical engineering investigation provided by the present application, the rear end cover is provided with a radial sliding groove, and the radial slider is slidably arranged in the sliding groove;

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

[0093] In this embodiment, the notch of the sliding groove communicates with the pressure chamber, facilitating connection of the radial slider with the first and second self-locking wedge mechanisms. A pressure relief hole is provided at one end of the sliding groove to prevent drilling fluid entering the sliding groove from forming resistance at the end of the radial slider.

[0094] In a specific implementation, the rear end cover is circular, and the sliding groove is arranged along the radial direction of 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, and when the radial slider is located at the radially inward end of the sliding groove, it is in a avoiding position.

[0095] See also Figure 2 and 4 As a specific embodiment of the rock coring device for geotechnical engineering investigation provided by this application, the first self-locking wedge mechanism includes:

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

[0097] The first wedge is provided on the side of the trigger plate facing the pressure cavity, and has an inclined surface in sliding fit with the first inclined surface.

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

[0099] Please refer to Figure 2 and 4 , as a specific embodiment of the rock coring device for geotechnical investigation provided in the present application, the second self-locking wedge mechanism comprises:

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

[0101] The rear end surface of the side wall of the sampling cylinder forms a second inclined surface in sliding fit with the inclined surface of the second wedge.

[0102] In a specific implementation, the radial slider is provided with a protrusion facing the sampling cylinder side wall, and the protrusion has a second inclined surface on the side away from the piston cavity. The rear end of the sampling cylinder side wall faces the radial slider, and the rear end surface is inclined and in sliding fit with the second inclined surface.

[0103] Please refer to Figure 2 and 4 , as a specific embodiment of the rock coring device for geotechnical investigation provided in the present application, the included angle between the matching 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 included angle between the matching inclined surface of the second self-locking wedge mechanism and the axis of the drilling cylinder is greater than or equal to 60°.

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

[0106] Please refer to Figure 1 and 5 , as a specific embodiment of the rock coring device for geotechnical investigation provided in the present application, the rock coring device for geotechnical investigation further comprises a flow relief mechanism; the flow relief mechanism comprises:

[0107] The connecting pipe is provided with a flow relief port on the side surface, and one end is in communication with the water inlet hole;

[0108] The closure sleeve is sleeved outside the connecting pipe, and moves forward to close the flow relief port and moves backward to open the flow relief port;

[0109] A limiting structure is further provided between the rear end cover and the trigger plate; the limiting structure comprises:

[0110] The connecting rod is detachably connected with the trigger plate at one end and connected with the closing sleeve through the through hole of the rear end cover at the other end.

[0111] The trigger plate moves forward to drive the closing sleeve to close the flow outlet, and moves backward to drive the closing sleeve to avoid the flow outlet.

[0112] In the embodiment, the limiting structure is used to limit the distance of the forward movement (downward in the figure) of the trigger plate, so as to avoid the trigger plate from being pulled out of the sampling cylinder. The flow outlet mechanism is linked with the limiting structure. When the sample fills the sampling cylinder, the trigger plate drives the closing sleeve to move backward (upward in the figure) through the connecting rod, so as to open the flow outlet. After the sampling is completed, the drilling fluid can flow out of the flow outlet, and the pressure in the pressure chamber is released, so that the trigger plate is no longer pressed by the drilling fluid in the pressure chamber, and the sample in the sampling cylinder is prevented from being pushed out.

[0113] In the specific implementation, the connecting pipe is fixed at the center of the rear end cover, and a thread is arranged outside the connecting pipe for connecting with the drill rod of the drilling machine. The connecting pipe simultaneously functions as power transmission and drilling fluid introduction. An inclined reinforcing rib can be arranged between the outer periphery of the connecting pipe and the rear end cover to increase the connecting strength of the connecting pipe and the rear end cover. Of course, the connecting pipe can also be fixed at the eccentric position of the rear end cover and only used for drilling fluid introduction. Other connecting heads are arranged at the center of the rear end cover for power transmission of the drill rod.

[0114] The closing sleeve is sleeved outside the connecting pipe and can slide forward and backward. The closing sleeve does not need to be particularly tight when closing the flow outlet, and a small amount of drilling fluid is allowed to leak out, but it should be ensured that sufficient pressure is formed in the pressure chamber. The small amount of drilling fluid leaked from the flow outlet can achieve the cooling of the rear part of the coring device.

[0115] The trigger plate is connected with the closing sleeve through the connecting rod. On the one hand, the connecting rod can push the closing sleeve backward (upward in the figure) to open the flow outlet when the trigger plate retreats (upward in the figure), and on the other hand, the connecting rod can also drive the closing sleeve to close the flow outlet when the trigger plate moves forward and backward (downward in the figure) and is limited by the closing sleeve.

[0116] When the sample needs to be taken out, the connecting rod is detached from the trigger plate, and the trigger plate can move forward (downward in the figure) to push out the sample. Specifically, after the connecting rod is removed, a long rod is inserted into the through hole of the rear end cover to push the trigger plate forward (downward in the figure).

[0117] Specifically, the connecting rod and the through hole of the rear end cover should be closely matched to form a certain sealing effect and ensure the pressure in the pressure chamber.

[0118] Please refer to Figure 5As a specific embodiment of the rock coring device for geotechnical engineering investigation provided in this application, an earmuff is provided on the outside of the closing sleeve, one end of the connecting rod is threadedly connected to the earmuff, and the other end is threadedly connected to the trigger plate, and the thread directions at both ends of the connecting rod are opposite.

[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 a specific implementation, two, three or four earmuffs can be evenly distributed on the periphery of the closed sleeve, and a connecting rod is correspondingly provided for each earmuff, and the two ends of each connecting rod are respectively connected to the trigger plate and the corresponding earmuff.

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

Claims

1. A rock coring device for geotechnical engineering investigation, characterized in that: include: Drilling tube; a cutting portion rotatably disposed on the side wall of the front end of the drilling tube; When the cutting portion is at a working angle, the cutting edge of the cutting portion is inclined outward, so that the cutting edge forms an inward reaction force when cutting; the cutting portion can rotate inward from the working angle; A sampling barrel is sleeved in the drilling barrel and is capable of axially moving relative to the drilling barrel; During drilling, the cutting portion is at the working angle, the reaction force of the cutting edge pushes the cutting portion to deflect inward, and the sampling tube partially limits the inward deflection of the cutting portion, so that the cutting portion is positioned at the working angle; Before sampling, the sampling tube can be axially moved relative to the drilling tube to release the restriction on the cutting portion, thereby causing the cutting portion to be pushed inward by the reaction force and cut the root of the sample.

2. The rock coring device for geotechnical engineering investigation according to claim 1, characterized in that: When the cutting portion is at the working angle, in the radial direction of the drilling tube, the cutting edge of the cutting portion extends to the front of the side wall of the front end of the sampling tube and is supported and limited by the side wall of the front end of the sampling tube; The sampling tube can move backward relative to the drilling tube to release the restriction on the cutting part.

3. The rock coring device for geotechnical engineering investigation according to claim 2, characterized in that: A right-angle notch is partially provided on the cutting portion, the side wall of the front end of the sampling tube is embedded in the right-angle notch, and the front end surface and the outer side surface of the sampling tube are respectively against the wall surfaces of the adjacent right-angle notch.

4. The rock coring device for geotechnical engineering investigation according to claim 1, characterized in that: The rock coring device for geotechnical engineering investigation further includes a trigger mechanism; The rear end of the drilling tube is closed by a rear end cover; a sealing fit is formed between the rear end of the sampling tube and the rear end of the drilling tube; The trigger mechanism comprises: A trigger plate is axially slidably disposed in the sampling barrel; the trigger plate is in sealing engagement with the inner wall of the sampling barrel to seal the rear end of the drilling barrel 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 provided on the rear end cover to switch between a support position and an avoidance position; the rear end cover is provided with a piston cavity communicated with the water inlet hole, one end of the radial slider forms a piston structure and is inserted into the piston cavity, and is adapted to switch to the support position under the push of water flow in the piston cavity; a first self-locking wedge mechanism, wherein the trigger plate drives the radial slider to switch to the avoidance position through the first self-locking wedge mechanism; a second self-locking wedge mechanism, wherein the radial slider drives the sampling tube to limit the cutting portion through the second self-locking wedge mechanism; After the water in the water inlet hole reaches a 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 lock that keeps the radial slider in the avoidance position, and then the water flow in the water inlet hole pushes the radial slider to switch to the supporting position, and the second self-locking wedge mechanism drives the sampling barrel to move forward and maintains the forward support of the sampling barrel by 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 for the sampling cylinder.

5. The rock coring device for geotechnical engineering investigation according to claim 4, characterized in that: The rear end cover is provided with a radial sliding groove, and the radial sliding block is slidably arranged in the sliding groove; One end of the sliding groove is connected to the water inlet hole through the piston cavity, and the other end is provided with a pressure relief hole connected to the outside. The notch of the sliding groove is connected to the pressure cavity, and the radial slider is connected to the first self-locking wedge mechanism and the first self-locking wedge mechanism through the notch of the sliding groove.

6. The rock coring device for geotechnical engineering investigation according to claim 4, characterized in that: The first self-locking wedge mechanism comprises: A first inclined surface is provided on the radial slider and is inclined away from the piston chamber; The first wedge has an inclined surface that is slidably engaged with the first inclined surface and is arranged on a side of the trigger plate facing the pressure chamber.

7. The rock coring device for geotechnical engineering investigation according to claim 4, characterized in that: The second self-locking wedge mechanism comprises: A second wedge block is provided on the radial slider and has an inclined surface inclined away from the piston cavity; The rear end surface of the side wall of the sampling tube forms a second inclined surface that is slidably engaged with the inclined surface of the second wedge block.

8. The rock coring device for geotechnical engineering investigation according to claim 4, characterized in that: The included angle between the matching inclined surface of the first self-locking wedge mechanism and the axis of the drilling barrel is less than or equal to 30°; The included angle between the matching inclined surface of the second self-locking wedge mechanism and the axis of the drilling barrel is greater than or equal to 60°.

9. The rock coring device for geotechnical engineering investigation according to claim 4, characterized in that: The rock coring device for geotechnical engineering investigation further includes a discharge mechanism; the discharge mechanism includes: A connecting pipe, with a drain port provided on the side and one end connected to the water inlet; A sealing sleeve is sleeved on the outside of the connecting pipe, 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 comprises: A connecting rod, one end of which is detachably connected to the trigger plate, and the other end of which passes through the rear end cover through a through hole and is connected to the closing sleeve; The trigger plate moves forward, driving the sealing sleeve to close the drain port; the trigger plate moves backward, driving the sealing sleeve to avoid the drain port.

10. The rock coring device for geotechnical engineering investigation according to claim 9, characterized in that: An earmuff is provided on the outside of the sealing sleeve. One end of the connecting rod is threadedly connected to the earmuff, and the other end is threadedly connected to the trigger plate. The thread directions of the two ends of the connecting rod are opposite.

Images