Rock crushing and coring equipment for geotechnical engineering investigation
Through the cooperation of the rotary material holding mechanism and auxiliary material discharge mechanism, the problems of spring fatigue and cylindrical core samples in traditional core extraction equipment are solved, stable cutting of the core and high-fidelity sample acquisition are achieved, and the accuracy of geological analysis is improved.
Patent Information
- Application Number
- CN202511061285.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-09-02
AI Technical Summary
In existing crushing rock core collection equipment, traditional material holding parts are prone to fatigue and temperature drifting by using springs to provide thrust, resulting in pressure attenuation. The core sample taken out is cylindrical, which cannot provide high-fidelity adaptive samples, affecting the accuracy of alternating mineralization research.
The rotary material holding mechanism and auxiliary material discharge mechanism are used to rotate and cut the core into a uniformly recessed ring through the rotary material holding mechanism. The combination of the counterweight ring and the cutting knife is used to ensure that the cutting knife always sticks to the surface of the core, and the secondary crushing is carried out with the conical column and bumps. The gravel is discharged through the blanking valve to achieve in-situ cutting and precise layering.
The stable cutting of the core and high-fidelity sample acquisition are achieved, and high-fidelity alteration mineralization research samples are provided, which avoids the problems of spring fatigue and temperature drift, and improves the accuracy of geological analysis.
Smart Images
Figure CN120575802A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of rock and soil coring, in particular to a rock and soil engineering survey and crushing coring device. Background Art
[0002] Crushed rock coring equipment is an indispensable core equipment in the field of geological exploration. Through the combination of precise mechanical structure and drilling technology, it can penetrate hard or broken strata and extract complete core samples. In deep drilling, continuous cores of tens to thousands of meters can be obtained, providing a complete time-to-space archive for studying stratigraphic sedimentary sequences, tectonic evolution and mineralization, and can also support alteration and mineralization research.
[0003] In the existing technology, the rock coring equipment is first fixed at the exploration point, and the rock core is crushed by rotating the drill bit to enter the inner cavity of the hollow drill bit. The pusher seat is pressed up to avoid it, and the holding component is in an open state. After drilling to the target depth, the core holding component drives the arc-shaped holding plate through a spring to hold the core tightly to prevent it from falling off. The drill bit is lifted by the telescopic cylinder to bring the core out of the ground, and finally the core is automatically pushed out by the pusher spring. However, the current holding components usually use springs to provide thrust, which is prone to pressure attenuation caused by spring fatigue and temperature drift. In addition, the core samples traditionally taken out are usually cylindrical, which cannot provide high-fidelity adaptive samples for alteration and mineralization research, thereby affecting the accuracy of geological analysis. Summary of the Invention
[0004] In order to solve the problem raised in the above background technology that the core samples taken traditionally are usually cylindrical and cannot provide high-fidelity adapted samples for alteration and mineralization research, the present invention provides a rock coring device for geotechnical engineering investigation.
[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a rock coring device for geotechnical engineering investigation and crushing, comprising a drill pipe, a drill bit being threadedly connected to the bottom of the drill pipe, a core pipe being sleeved together in the inner cavity of the drill pipe and the drill bit, a clamping belt being installed at the lower end of the inner cavity of the core pipe, and further comprising: a rotary material holding mechanism, the rotary material holding mechanism being located above the clamping belt and connected to the core pipe; and an auxiliary material discharge mechanism, the core pipe and the drill bit being connected together with the auxiliary material discharge mechanism; Among them, after the core is taken to the designated position, the equipment stops the deep drilling operation and keeps rotating at the current position. The elliptical core is rotated and cut into a uniformly concave layer through the rotary cutting and holding mechanism, and the cut debris is discharged through the auxiliary discharge mechanism; the bottom of the core tube is connected to the top inner cavity of the drill bit through an annular clamp block, which helps to increase the sealing. At the same time, the rotation direction of the drill pipe and drill bit is consistent with the direction of the installed thread groove to ensure that the drill bit will not be separated from the drill pipe during drilling. During operation, the drill bit is aimed at the specific survey point of the rock and soil and drills in. The crushing teeth at the bottom of the drill bit rotate to crush the rock until the core enters the inner cavity of the hollow core tube. During this process, the core is cut into a columnar shape by the drill bit. During the upward movement, the clamping belt is pressed and moves to avoid.
[0006] Preferably, the turning and holding mechanism includes a plurality of holding plates equidistantly connected to the inner cavity at the bottom of the core tube. The shape of the holding plates is a semi-ellipse cut along the short axis, and the arc surface is arranged in the direction of the holding belt. An expansion cavity is opened at the lower end of the core tube, and the plurality of holding plates are all connected at the bottom of the expansion cavity.
[0007] Preferably, the arc-shaped surface of the holding plate is provided with at least two chip grooves, each of which is fixed with a cutter, and the thickness of the cutter is larger than the depth of the chip groove; after drilling to the target depth, the drill pipe and the core tube maintain their current position and continue to rotate, and the cutter always adheres to the surface of the core and rotates the core to cut out a uniformly concave circle.
[0008] Preferably, the chip removal groove and the turning and holding mechanism are both laid on one side of the curved surface of the holding plate in a spirally inclined manner, and both are distributed on the side of the holding plate away from the connection position.
[0009] Preferably, a plurality of conical columns are evenly distributed on the side of the holding plate away from the cutter, and at least one pair of protrusions are evenly fixed to the outer wall of the conical columns; the conical columns cooperate with the protrusions to form a grinding part, which crushes the cut gravel into a smaller particle size for the second time, ensuring that it passes through the blanking valve smoothly without jamming, and the ground gravel is discharged through the blanking valve.
[0010] Preferably, the plurality of conical columns are arranged obliquely relative to the material holding plate, and the size of the conical columns is gradually increased from the end to the connection position of the material holding plate, which is conducive to grinding the bottom gravel accumulation area through larger-sized conical columns, thereby increasing the crushing effect.
[0011] Preferably, the auxiliary discharge mechanism includes a counterweight ring, the outer wall of which is slidably connected to the expansion cavity, and the counterweight ring is in contact with the holding plate; when the holding plate is squeezed and opened by the core, the counterweight ring can be squeezed upward by the inclined conical column until it reaches the top of the holding plate. During the rotary cutting process, the gravity of the counterweight ring can continuously press the holding plate inward to maintain the stability of the incision.
[0012] Preferably, an inner support ring block is fixedly connected to the inner cavity of the drill bit, and the inner support ring block abuts against the outer wall of the lower end of the core tube.
[0013] Preferably, the inner cavity of the inner support ring block is provided with at least a pair of drainage channels, which are connected to the gap space between the core sampling tube and the drill pipe; the core is rotated to cut out a uniformly concave ring layer, and the rotated gravel falls into the aggregate trough, is discharged into the drainage channel through the discharge valve, and is finally discharged out of the device.
[0014] Preferably, a collection trough is provided at the bottom of the expansion cavity, and at least a pair of blanking valves are fixedly connected to the inner cavity edge of the core sampling tube, and the blanking valves are respectively connected to the collection trough and the sewage channel; through the four-level coordination of the holding plate, cutter, counterweight ring and blanking valve, under the premise of ensuring the stability of the core structure, the integrated operation of in-situ cutting to precise stratification and then to automatic slag discharge is realized, providing high-fidelity samples for alteration and mineralization research, and effectively integrating geological analysis needs into the coring equipment.
[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention cooperates with structures such as a holding plate and a cutter, and then rotates the core to cut out a specific shape of an arc-shaped uniformly concave ring layer, which is convenient for studying the alteration rate of the core. After drilling to the target depth, the drill pipe and the core sampling pipe maintain their current position and continue to rotate. The gravity of the counterweight ring allows the cutter on the holding plate to always fit the surface of the core, and the outer ring of the core is rotated and cut off a layer. The rotation is continued to rotate the core to cut out a uniformly concave ring layer. The rotated gravel falls into the aggregate trough, is discharged into the sewage channel through the blanking valve, and finally discharged out of the device. Through the four-level coordination of the holding plate, cutter, counterweight ring and blanking valve, under the premise of ensuring the stability of the core structure, the integrated operation of in-situ cutting to precise stratification and then to automatic slag discharge is realized, providing high-fidelity samples for alteration and mineralization research, and effectively integrating the needs of geological analysis into the coring equipment.
[0016] The present invention facilitates the stable cutting of the core by setting up the coordination of structures such as the counterweight ring and the cutter. The use of the counterweight ring replaces the spring in the prior art to push the holding plate, thereby eliminating the pressure attenuation caused by spring fatigue and temperature drift. When the holding plate is squeezed and opened by the core, the counterweight ring can be squeezed upward by the inclined conical column. During the rotational cutting process, the gravity of the counterweight ring can continuously press the holding plate inward, and the vertical potential energy of the counterweight ring is converted into the radial clamping force of the holding plate, keeping the cutter always in contact with the core, thereby improving the smoothness of the incision. During sampling, the holding plate is in contact with the thin neck section of the core through the cutter, and is stably clamped by the counterweight ring to avoid vibration breakage of the core during the lifting process. The arc-shaped depression layer obtained by stable cutting retains the original micro-crack network, providing real geological parameters for the calculation of the alteration rate.
[0017] The present invention facilitates the discharge of cut gravel by arranging the cooperation of structures such as chip discharge grooves and tapered columns. A tapered column is provided on the back of the holding plate, which cooperates with the protrusions to form a grinding part, so that the cut gravel is crushed to a smaller particle size for the second time, ensuring that it passes through the blanking valve smoothly without getting stuck. The ground gravel is discharged through the blanking valve. When sampling at the end, the drill bit is unscrewed and the sewage channel is flushed to completely remove the accumulated mud and sand. At this time, the core can be pushed to continue to rotate the holding plate, and the cut gravel can easily pass through the blanking valve without being blocked by accumulated gravel. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the present invention; Figure 3 Schematic diagram of the structural coordination relationship between the drill pipe and the core pipe of the present invention; Figure 4 Schematic diagram of the structural coordination relationship between the drill bit and the inner support ring block of the present invention; Figure 5 This is a schematic diagram of the top view of the structure of the present invention; Figure 6 This is a schematic diagram of the structure of the present invention when viewed from above; Figure 7 This is a schematic diagram of the structural coordination relationship between the holding plate and the counterweight ring of the present invention; Figure 8 Schematic diagram of the structural coordination relationship between the tapered column and the cutter of the present invention; Figure 9 Schematic diagram of the structural matching relationship between the tapered column and the bump of the present invention; Figure 10 This is a schematic diagram of the side structure of the holding plate of the present invention; Figure 11 It is a schematic diagram of the structural coordination relationship between the cutter and the chip removal groove of the present invention.
[0019] In the figure: 1. Drill pipe; 2. Coring tube; 3. Drill bit; 4. Holding belt; 5. Turning and holding mechanism; 51. Holding plate; 52. Cutter; 53. Conical column; 54. Expanding cavity; 55. Bump; 56. Chip discharge groove; 6. Auxiliary discharge mechanism; 61. Counterweight ring; 62. Blanking valve; 63. Drain channel; 64. Collecting trough; 65. Inner support ring block. DETAILED DESCRIPTION
[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0021] like Figures 1 to 11 As shown, the present invention provides a rock coring device for geotechnical engineering investigation and crushing, comprising a drill pipe 1, a drill bit 3 being threadedly connected to the bottom of the drill pipe 1, a core pipe 2 being sleeved together in the inner cavity of the drill pipe 1 and the drill bit 3, a clamping belt 4 being installed at the lower end of the inner cavity of the core pipe 2, and further comprising: a rotary material holding mechanism 5, the rotary material holding mechanism 5 being located above the clamping belt 4 and connected to the core pipe 2; and an auxiliary material discharge mechanism 6, the core pipe 2 and the drill bit 3 being connected together with the auxiliary material discharge mechanism 6; Among them, after the core is taken to the specified position, the equipment stops the deep drilling operation and keeps rotating at the current position. The elliptical core is rotated and cut into a uniformly concave layer through the turning and holding mechanism 5, and the cut debris is discharged through the auxiliary discharge mechanism 6.
[0022] The above solution uses an annular clamping block at the bottom of the core tube 2, which is connected to the top inner cavity of the drill bit 3 to enhance sealing. The rotation direction of the drill tube 1 and drill bit 3 aligns with the direction of the threaded groove, ensuring that the drill bit 3 will not detach from the drill tube 1 during drilling. Before using the equipment, first install and secure the equipment body at the survey point. Then check whether the drill tube 1 and drill bit 3 are properly connected to the equipment's drive device. After completing other preparatory work, align the drill bit 3 with the specific survey point in the rock and soil and drill it in. The crushing teeth at the bottom of the drill bit 3 rotate and crush the rock until the core enters the inner cavity of the hollow core tube 2.
[0023] like Figure 2 As shown, the turning and holding mechanism 5 includes a plurality of holding plates 51 equidistantly connected to the inner cavity at the bottom of the core tube 2. The shape of the holding plate 51 is a semi-elliptical shape cut along the short axis, and the arc surface is arranged in the direction of the holding belt 4. An expansion cavity 54 is opened at the lower end of the core tube 2, and the plurality of holding plates 51 are all located at the bottom of the expansion cavity 54 and connected.
[0024] like Figures 9 to 11 As shown, the curved surface of the holding plate 51 is provided with at least two chip grooves 56, and a cutter 52 is fixed in the chip groove 56. The thickness of the cutter 52 is larger than the depth of the chip groove 56; the chip groove 56 and the turning holding mechanism 5 are both laid in a spirally inclined manner on one side of the curved surface of the holding plate 51, and both are distributed on the side of the holding plate 51 away from the connection position.
[0025] like Figures 7 to 9 As shown, a number of conical columns 53 are evenly distributed on the side of the holding plate 51 away from the cutter 52, and at least a pair of protrusions 55 are evenly fixed to the outer wall of the conical columns 53; the multiple conical columns 53 are all inclined relative to the holding plate 51, and the size of the conical columns 53 is gradually increased from the end to the connection position of the holding plate 51.
[0026] The above solution employs a tungsten carbide coating welded on the inner surface of the expansion cavity 54, achieving a hardness ≥ HRA89. This coating provides a lifespan of 1200 hours in highly abrasive rock crushing conditions, such as basalt, and enhances the wear resistance of the expansion cavity 54. The crushing teeth at the bottom of the drill bit 3 rotate and crush the rock until the core enters the hollow coring tube 2. During this process, the core is cut into a columnar shape by the drill bit 3. During upward movement, the weight of the counterweight ring 61 ensures that the cutter 52 on the holding plate 51 maintains contact with the core surface, rotating the core to create a uniform, concave ring. The rock fragments removed from the core are guided into the expansion cavity 54 via a chip flute 56. The tapered columns 53 and bumps 55 on the back of the holding plate 51 break the strips of rock into smaller particles. Because the size of the tapered columns 53 gradually increases from the end to the connection point of the holding plate 51, the larger tapered columns 53 grind the rock at the bottom where it accumulates, enhancing the crushing effect.
[0027] like Figures 2 to 7 As shown, the auxiliary discharge mechanism 6 includes a counterweight ring 61, the outer wall of the counterweight ring 61 is slidably connected to the expansion cavity 54, and the counterweight ring 61 abuts against the material holding plate 51; the inner cavity of the drill bit 3 is fixed with an inner support ring block 65, and the inner support ring block 65 abuts against the outer wall of the lower end of the core tube 2.
[0028] like Figure 2 As shown, the inner cavity of the inner supporting ring block 65 is provided with at least a pair of drainage channels 63, which are connected to the gap space between the core tube 2 and the drill pipe 1; a collection trough 64 is provided at the bottom of the expansion cavity 54, and at least a pair of blanking valves 62 are fixedly connected to the edge of the inner cavity of the core tube 2, and the blanking valves 62 are respectively connected to the collection trough 64 and the drainage channel 63.
[0029] Adopt the above scheme: after reaching the target depth, the drill pipe 1 and the core sampling pipe 2 keep their current position and continue to rotate. The weight of the counterweight ring 61 makes the cutter 52 on the holding plate 51 always fit the surface of the core, and the outer ring of the core is rotated and cut off a layer. The rotation is continued to rotate the core to cut out a uniform concave circle. The crushed stone falls into the collecting trough 64, is discharged into the sewage channel 63 through the discharge valve 62, and finally discharged out of the device. After the core is cut into the specified shape, the position of the holding plate 51 is as follows: Figure 8 As shown, the core is shaped as indicated by the dotted line in the figure. The drill pipe 1 and core sampling tube 2 are then lifted, allowing the gripping band 4 to grip the bottom of the core to prevent it from falling out. The drill bit 3 is then lifted, breaking the bottom of the core and bringing the upper portion of the core to the surface. When the device is lifted, the gripping plate 51, via the cutter 52, abuts the narrow neck of the core. The counterweight ring 61 provides a stable grip, preventing vibration and breakage of the core during the lifting process. The use of the counterweight ring 61 replaces the spring used in the prior art to push against the gripping plate 51, enhancing the durability of the device.
[0030] The working principle and use process of the present invention: First, the equipment body is installed and fixed at the survey point. Then check whether the drill pipe 1 and the drill bit 3 are connected to the drive device of the equipment normally. After other preparations are completed, the drill bit 3 is aimed at the specific survey point of the rock and soil and drilled in. The crushing teeth at the bottom of the drill bit 3 rotate and crush the rock until the core enters the inner cavity of the hollow core tube 2. During this process, the core is cut into a column by the drill bit 3. During the upward movement, the holding belt 4 is pressed and moved to avoid. The core continues to move upward, and then the curved surface of the holding plate 51 first contacts the core, squeezes and rotates, and then moves from the initial Figure 2 Parallel rotation Figure 4 After drilling to the target depth, the drill pipe 1 and the core sampling pipe 2 maintain their current positions and continue to rotate. The weight of the counterweight ring 61 keeps the cutter 52 on the holding plate 51 in contact with the core surface, and the outer ring of the core is rotated and cut off a layer. The rotation continues, and the core is rotated to cut out a uniform concave layer. The crushed stone falls into the collecting trough 64, is discharged into the sewage channel 63 through the discharge valve 62, and finally discharged out of the device. After the core is cut into the specified shape, the position of the holding plate 51 is as shown in FIG. Figure 8 As shown, the core is shaped like the dotted line in this figure. The drill pipe 1 and core sampling tube 2 are then lifted, allowing the gripping band 4 to grip the bottom of the core to prevent it from falling out. The drill bit 3 is then lifted, breaking the bottom of the core and bringing the upper portion of the core to the surface. To obtain a core sample, the drill bit 3 is rotated alone to separate the remaining drill pipes 1. Impurities in the drainage channel 63 are then removed, and the core is pushed in the opposite direction, squeezing the gripping plate 51 further open to push the core sample out. Secondly, when the holding plate 51 is squeezed and opened by the rock core, the weight ring 61 can be squeezed upward by the inclined conical column 53 until it reaches the top of the holding plate 51. During the rotary cutting process, the gravity of the weight ring 61 can continuously press the holding plate 51 inward to maintain the stability of the incision. When the device is lifted, the holding plate 51 is abutted against the thin neck section of the rock core through the cutter 52, and is stably clamped by the weight ring 61 to prevent the rock core from being vibrated and broken during the lifting process. The use of the weight ring 61 replaces the spring in the prior art to push the holding plate 51, thereby enhancing the durability of the device. Finally, the rock fragments removed from the core are directed to the sides through the chip flutes 56 and collected around the expansion chamber 54. At this point, the tapered columns 53 and bumps 55 on the back of the holding plate 51 break up the strips of rock fragments and grind them into smaller particles. Because the size of the tapered columns 53 gradually increases from the end to the connection point of the holding plate 51, the larger tapered columns 53 grind the rock fragments at the bottom where they accumulate, enhancing the crushing effect.
[0031] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.
[0032] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A rock coring device for geotechnical engineering investigation and crushing, comprising a drill pipe (1), a drill bit (3) being threadedly connected to the bottom of the drill pipe (1), a core tube (2) being sleeved together in the inner cavities of the drill pipe (1) and the drill bit (3), a clamping belt (4) being installed at the lower end of the inner cavity of the core tube (2), and characterized in that: Also includes: A turning and holding mechanism (5), the turning and holding mechanism (5) is located above the holding belt (4) and is connected to the core tube (2); An auxiliary discharge mechanism (6), wherein the core tube (2) and the drill bit (3) are connected to the auxiliary discharge mechanism (6); After reaching the designated position of the core, the equipment stops the deep drilling operation and keeps rotating at the current position. The elliptical core is rotated and cut into a uniform concave layer through the rotary cutting and holding mechanism (5), and the cut debris is discharged through the auxiliary discharge mechanism (6).
2. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 1, characterized in that: The turning and holding mechanism (5) comprises a plurality of holding plates (51) equidistantly connected to the inner cavity at the bottom of the core tube (2). The holding plates (51) are in the shape of a semi-ellipse cut along a horizontal plane, and the arcuate surface is arranged in the direction of the holding belt (4). An expansion cavity (54) is provided at the lower end of the core tube (2), and the plurality of holding plates (51) are all connected to the bottom of the expansion cavity (54).
3. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 2, characterized in that: The arc-shaped surface of the holding plate (51) is provided with at least two chip removal grooves (56), each of which is fixed with a cutter (52), and the thickness of the cutter (52) is greater than the depth of the chip removal groove (56).
4. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 3, characterized in that: The chip removal groove (56) and the remaining components of the turning and holding mechanism (5) are all laid on one side of the arc surface of the holding plate (51) in a spirally inclined manner, and are all distributed on the side of the holding plate (51) away from the connection position.
5. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 4, characterized in that: A plurality of conical columns (53) are distributed on a side of the holding plate (51) facing away from the cutter (52), and at least one protrusion (55) is evenly fixed to the outer wall of the conical column (53).
6. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 5, characterized in that: The plurality of tapered columns (53) are all arranged obliquely relative to the holding plate (51), and the size of the tapered columns (53) is arranged to gradually increase from the top end thereof to the connection position of the holding plate (51).
7. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 6, characterized in that: The auxiliary discharge mechanism (6) comprises a counterweight ring (61), the outer wall of the counterweight ring (61) is slidably connected to the expansion cavity (54), and the counterweight ring (61) is in contact with the holding plate (51).
8. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 7, characterized in that: An inner supporting ring block (65) is fixedly connected to the inner cavity of the drill bit (3), and the inner supporting ring block (65) abuts against the outer wall of the lower end of the core tube (2).
9. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 8, characterized in that: The inner cavity of the inner supporting ring block (65) is provided with at least a pair of drainage channels (63), and the drainage channels (63) are connected to the gap space between the core tube (2) and the drill tube (1).
10. The rock crushing and coring equipment for geotechnical engineering investigation according to claim 9, characterized in that: A material collecting trough (64) is provided at the bottom of the expansion cavity (54), and at least one pair of blanking valves (62) are fixedly connected to the lower edge of the inner cavity of the core tube (2), and each blanking valve (62) is connected to the material collecting trough (64) and the sewage channel (63) on both sides.