A hollow torsional shear testing device for rock

Abstract

The application discloses a hollow torsional shear testing device for rock, and belongs to the technical field of rock material mechanics testing devices.The device comprises an upper shear fixing mechanism and a lower shear torsion mechanism, characterized in that the upper shear fixing mechanism is in sliding connection with the lower shear torsion mechanism, and a sample end fixing assembly for clamping and fixing a hollow rock sample is movably arranged on the upper shear fixing mechanism and the lower shear torsion mechanism; two groups of torque applying assemblies are fixed on the lower shear torsion mechanism; and the torque applying assemblies apply torque to the hollow rock sample in the form of a pulley block combining a fixed pulley and a movable pulley.The torsional shear testing device can improve the stability of sample fixing, reduce the loss of torque caused by the slight deformation of the rock sample under the action of torque, and improve the accuracy of applying torque to the rock sample.

Description

Technical Field

[0001] The invention relates to the technical field of rock material mechanics testing devices, in particular to a hollow torsion shear testing device for rocks. Background Art

[0002] Rock masses subjected to torsion and shear during drilling and excavation operations are often subjected to stresses that differ significantly from conventional compression and tension tests of rock mechanics. Therefore, testing the torsion and shear properties of rock is of great significance. Because most rocks are brittle and hard, it is difficult to machine threads or other special shapes that facilitate clamping. Therefore, hollow, circular rock specimens are often used to test their torsion and shear properties to reduce the difficulty of applying torque.

[0003] At present, the torsional shear stress of rocks is usually applied by hydraulic and motor drive. The invention patent application document with application number 201810316676.X discloses a rock hollow cylinder on-site torsional shear test device and method, which applies normal stress to the sample through a normal loading system, applies internal radial pressure to the sample through an internal pressure oil pump, and applies torsional stress to the sample through a shear bolt and a torsional motor that cooperates with it, thereby testing the mechanical properties of rocks under path conditions of complex stress states, but the torsional stress application method is not uniform and stable enough. The invention patent with application number 201710636542.1 discloses a rock torsional shear-compression comprehensive experimental device, which can realize torsional shear and uniaxial pressure at the same time, and can quickly and reliably install or remove samples, but the device is not light enough. Summary of the Invention

[0004] In response to the above-mentioned problems, the present invention aims to provide a hollow torsional shear testing device for rock, which improves the stability of sample fixation by simultaneously clamping the inner and outer walls of the sample with strong glue and round nails; loads torsional stress through a pulley group and a torsional motor, and designs a torque transmission path, thereby reducing the torque loss caused by slight deformation of the rock sample under the action of torque, and improving the accuracy of applying torque to the rock sample.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A hollow torsional shear testing device for rock, comprising an upper shear fixing mechanism and a lower shear torsional mechanism, characterized in that: the upper shear fixing mechanism is slidably connected to the lower shear torsional mechanism, and both the upper shear fixing mechanism and the lower shear torsional mechanism are provided with movable sample end fixing assemblies for clamping and fixing hollow rock samples, and the lower shear torsional mechanism is also fixed with two sets of torque applying assemblies, and the torque applying assemblies use a pulley group combining a fixed pulley and a movable pulley to apply torque to the hollow rock sample.

[0007] Furthermore, the upper shear fixing mechanism includes four retractable supporting legs, and a first mounting plate is fixed on the top of the four supporting legs. A circular first through hole is opened in the center of the first mounting plate, and an octagonal through hole is opened on the top of the first through hole. The inscribed circle diameter of the octagonal through hole is larger than the diameter of the first through hole. The sample end fixing assembly corresponding to the upper shear fixing mechanism is clamped in the octagonal through hole, and the bottom of the sample end fixing assembly passes through the first through hole.

[0008] Furthermore, the sample end fixing assembly includes an octagonal plate corresponding to the octagonal through hole, and two groups of sample outer wall fixing assemblies are slidably provided on the octagonal plate, and each group of the sample outer wall fixing assemblies includes two symmetrically arranged sliding rods, and an arc-shaped clamping ring is fixed to the bottom of each sliding rod, and the connecting line of the four clamping rings is a circular structure, and a number of fixing nails are provided on the inner side of the clamping ring; a sliding limit through hole for sliding of the sliding rod is opened on the octagonal plate, the sliding rod passes through the sliding limit through hole, and the clamping ring is located below the octagonal plate, and two groups of driving assemblies for driving the sliding rod to move are provided between the four sliding rods.

[0009] Furthermore, each group of the drive assemblies includes two mutually perpendicular drive rods, the two drive rods are arranged crosswise up and down, and the two drive rods are connected by a fixed block, both ends of each drive rod are threaded through the corresponding sliding rod, and the end of each drive rod is fixed with external teeth, and the ends of the two corresponding drive rods of the two groups of drive assemblies are connected by an annular toothed belt, and the annular toothed belt is engaged with the external teeth;

[0010] The driving rod includes a first screw rod and a second screw rod with opposite rotation directions. Each of the first screw rod and the second screw rod is fixedly connected via a connecting shaft, and the connecting shaft is rotatably connected to the fixed block.

[0011] Furthermore, a sample inner wall fixing assembly is slidably provided on the octagonal plate, and the structure of the sample inner wall fixing assembly is the same as that of the sample outer wall fixing assembly, but the size is smaller than that of the sample outer wall fixing assembly; and the sliding rod in the sample inner wall fixing assembly and the sliding rod in the sample outer wall fixing assembly are staggered along the circumference, and the fixing pins on the sample inner wall fixing assembly are located on the outer walls of the clamping rings corresponding to each other.

[0012] Furthermore, the lower shear and torsion mechanism includes an intermediate plate and two side plates, the upper shear fixing mechanism is slidably mounted on the intermediate plate, and the two groups of torque applying assemblies are respectively mounted on the two side plates; a support ring is fixed to the top center of the intermediate plate, a torsion disk is rotatably sleeved on the support ring, and a first through hole and an octagonal through hole that are connected to each other up and down are also opened on the torsion disk, the sample end fixing assembly corresponding to the lower shear and torsion mechanism is clamped in the octagonal through hole, and the installation direction of the sample end fixing assembly corresponding to the lower shear and torsion mechanism is opposite to the installation direction of the sample end fixing assembly corresponding to the upper shear fixing mechanism.

[0013] Furthermore, the torsion disk is a circular disk structure that is symmetrically cut off on both sides, and two parallel grooves are provided on the two curved sides of the torsion disk. The two opposite corners of the two curved sides of the torsion disk are fixed with first fixing columns for fixing the slide rope; the two opposite corners of the two side panels are fixed with first support columns for installing the torque application assembly.

[0014] Furthermore, the torque applying assembly includes a bottom mounting block fixedly mounted on the top of the first support column, and an F-shaped support member fixedly mounted on the side panel, the end of the bottom mounting block away from the first support column is fixedly connected to the top of the middle rod of the F-shaped support member; torsion motors are mounted on the left and right sides of the bottom mounting block, the two torsion motors have different heights, and a hollow pulley is mounted on the output shaft of each torsion motor; an inverted Z-shaped support column is also fixedly mounted on the top of the bottom mounting block, a top mounting block is fixedly mounted on the top of the inverted Z-shaped support column, and two second fixed columns of different heights are respectively fixedly mounted between the inverted Z-shaped support column and the bottom mounting block and the top mounting block, and the second fixed column is also used to fix the slide rope; a pulley group for connecting the slide rope is provided between the bottom mounting block, the top mounting block and the F-shaped support member.

[0015] Furthermore, the pulley assembly includes a fixed pulley assembly and a movable pulley assembly, the fixed pulley assembly includes a fixed pulley shaft fixedly arranged between the bottom mounting block and the top mounting block, a fixed pulley sleeve is fixedly sleeved on the fixed pulley shaft, the cross-section of the fixed pulley sleeve is I-shaped, and the fixed pulley sleeve is fixedly provided with two circles of first sliding clasps along the circumferential direction, and the two first sliding clasps are rotatably connected to the hollow pulley;

[0016] The movable pulley assembly includes a movable pulley sleeve slidably arranged between the top rod and the middle rod of the F-shaped support member. The cross-section of the movable pulley sleeve is also I-shaped, and a first sliding groove is provided on both horizontal parts of the I-shaped movable pulley sleeve. A sliding ring is slidably provided in each of the first sliding grooves, and an external hanging protrusion for connecting the sliding rope is fixed on the sliding ring; two circles of second sliding clamps are provided on the vertical section of the I-shaped movable pulley sleeve, and the two second sliding clamps are also rotatably connected to the hollow pulley.

[0017] Furthermore, the pulley assembly is connected to two different types of sliding ropes. The first type of sliding ropes has two ends, one end of which is connected to the external protrusion of the sliding ring, and the other end is connected to the first fixed columns corresponding to each other on the torsion disk, and the two first type of sliding ropes are respectively clamped in the grooves on the side walls of the torsion disk corresponding to each other;

[0018] The second type of pulley also has two ends, one end of which is connected to the hollow pulley installed on the output shaft of the torsion motor, and the other end passes around the hollow pulley installed on the corresponding movable pulley sleeve, and then passes around the hollow pulley installed on the corresponding fixed pulley sleeve, and finally fixed on the corresponding second fixed column.

[0019] The beneficial effects of the present invention are as follows: compared with the prior art, the improvement of the present invention is that:

[0020] 1. The hollow torsional shear testing device for rock in the present invention addresses the problem that current hollow torsional shear performance tests of rock cannot achieve efficient and convenient measurement. The outer wall and inner wall of the sample end are fixed simultaneously through the sample inner wall fixing component structure and the sample outer wall fixing component, and the fixing nails can penetrate into the strong adhesive layer during fixation, thereby improving the reliability of the fixation of the sample end; in addition, the pulley group is used to cooperate with the torsional motor to load the torsional force on the sample. Combined with the design of the torque transmission path, the torque loss caused by the slight deformation of the rock sample under the action of torque is reduced, thereby improving the accuracy of applying torque to the rock sample.

[0021] 2. In the present invention, when fixing the end of the sample, the rock samples of different diameters can be clamped and fixed by moving the two symmetrically arranged sliding rods toward each other or away from each other, and the retractable design of the support legs can adjust the distance between the upper shear fixing mechanism and the lower shear torsion mechanism, which is suitable for rock samples of different lengths; the parallel arrangement of the two sets of drive assemblies can improve the stability of the sliding rods during the sliding process, and the two sets of drive assemblies are connected by an annular toothed belt. Only one drive rod in one set of drive assemblies needs to be rotated to achieve synchronous rotation of the two sets of drive assemblies, which is simple to operate and highly efficient.

[0022] 3. In the present invention, a torsional shear force is applied to the sample through the cooperation of the pulley group and the torsion motor. The fixed pulley sleeve and the hollow pulley rotatably connected thereto form a fixed pulley assembly, which can play a role in fine-tuning the torque. The movable pulley sleeve and the hollow pulley rotatably connected thereto and the sliding ring form a movable pulley assembly. The movable pulley assembly moves along the F-shaped support member, which can play an effect of amplifying the force. Under the constraint of the groove on the outer wall of the torsion disk, the slide cable can be separated from the torsion disk along the tangential direction of the groove. After the sample produces angular deformation due to the torque, the torsion disk deforms with the sample, but the slide cable still moves away from the sample along the tangential direction of the groove. The force arm of the force applied by the slide cable will not change, and the torque applied to the sample will remain unchanged, thereby avoiding the situation where the experimental results are inaccurate due to the change in the actual torque applied to the sample after the sample undergoes angular deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of the hollow torsional shear testing device for rock of the present invention.

[0024] Figure 2 This is an axonometric view of the upper shear fixing mechanism structure of the present invention.

[0025] Figure 3 This is a bottom view of the upper shearing and fixing mechanism structure of the present invention.

[0026] Figure 4 This is an exploded view of the upper shear fixing mechanism structure of the present invention.

[0027] Figure 5 This is an exploded view of the support leg structure of the present invention.

[0028] Figure 6 This is an axonometric view of the specimen end fixing assembly structure of the present invention.

[0029] Figure 7 This is an exploded view of the specimen end fixing assembly structure of the present invention.

[0030] Figure 8This is a schematic diagram of the structure of the sliding rod and clamping ring corresponding to the specimen inner wall fixing assembly of the present invention.

[0031] Figure 9 This is a schematic diagram of the driving rod structure of the present invention.

[0032] Figure 10 This is an axonometric view of the lower shear-torsion mechanism structure of the present invention.

[0033] Figure 11 It is a schematic diagram of the structure of the middle plate and side plates of the present invention.

[0034] Figure 12 It is a structural schematic diagram of the torsion disk of the present invention.

[0035] Figure 13 This is an isometric view of the torque applying assembly structure of the present invention.

[0036] Figure 14 This is an exploded view of the torque applying assembly structure of the present invention.

[0037] Figure 15 This is a schematic diagram of the top and two side structures of the bottom mounting block of the present invention.

[0038] Figure 16 This is an exploded view of the fixed pulley assembly structure of the present invention.

[0039] Figure 17 This is a cross-sectional view of the fixed pulley sleeve structure of the present invention.

[0040] Figure 18 This is an exploded view of the movable pulley assembly structure of the present invention.

[0041] Figure 19 This is a front view of the external structure of the movable pulley assembly of the present invention.

[0042] Among them: 1-sample end fixing assembly, 101-octagonal plate, 1011-sliding limit through hole, 102-sliding rod, 103-clamping ring, 104-fixing nail, 105-driving rod, 1051-first screw, 1052-second screw, 1053-connecting shaft, 106-fixing block, 107-external teeth, 108-annular toothed belt, 2-torque application assembly, 201-bottom mounting block, 202-F-type support, 203-torsion motor, 204-inverted Z-shaped support column, 205-top mounting block, 206-second fixed column, 207-hollow pulley, 208-fixed pulley shaft, 209-fixed pulley sleeve, 210-first sliding clamping ring , 211-movable pulley sleeve, 212-first sliding groove, 213-sliding ring, 214-external protrusion, 215-second sliding clamp, 3-support leg, 301-outer sleeve, 3011-clip sheet, 302-adjusting cap, 303-inner rod, 304-slide plate, 305-ball, 4-first mounting plate, 401-first through hole, 402-octagonal through hole, 5-middle plate, 501-slide groove, 502-baffle, 6-side plate, 601-first support column, 7-support ring, 701-support rod, 8-torsion disk, 801-groove, 802-first fixed column, 100-upper shear fixing mechanism, 200-lower shear torsion mechanism. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0044] Refer to the attached Figure 1-19 The hollow torsional shear testing device for rock shown in the figure includes an upper shear fixing mechanism 100 and a lower shear torsional mechanism 200, wherein the upper shear fixing mechanism 100 is slidingly connected to the lower shear torsional mechanism 200, and both the upper shear fixing mechanism 100 and the lower shear torsional mechanism 200 are movable with a sample end fixing assembly 1 for clamping and fixing the hollow rock sample. The top end of the hollow rock sample can be clamped and fixed by the upper shear fixing mechanism 100, and the bottom end of the hollow rock sample can be clamped and fixed by the lower shear torsional mechanism 200. Two sets of torque applying assemblies 2 are also fixed on the lower shear torsional mechanism 200, and the torque applying assembly 2 uses a pulley group combining a fixed pulley and a movable pulley to apply torque to the hollow rock sample.

[0045] Specifically, the upper shear fixing mechanism 100 includes four retractable supporting legs 3, and a first mounting plate 4 is fixed to the top of the four supporting legs 3. A circular first through hole 401 is opened in the center of the first mounting plate 4, and an octagonal through hole 402 is opened at the top of the first through hole 401. The inscribed circle diameter of the octagonal through hole 402 is larger than the diameter of the first through hole 401. The sample end fixing assembly 1 corresponding to the upper shear fixing mechanism 100 is clamped in the octagonal through hole 402, and the bottom of the sample end fixing assembly 1 passes through the first through hole 401.

[0046] The support leg 3 includes an outer sleeve 301, and four flexible clips 3011 are symmetrically fixed on the top of the outer sleeve 301, and an outer thread is provided on the outer wall of the outer sleeve 301 close to the clips 3011. An inner rod 303 is slidably provided on the top of the outer sleeve 301, and the inner rod 303 is inserted into the four clips 3011 and the outer sleeve 301, and the outer thread of the outer sleeve 301 is connected to the adjustment cap 302, which is a hollow frustum-shaped structure and has a lower inner wall provided with a screw thread. The outer threads on the outer sleeve 301 match the inner threads, and the upper diameter is slightly smaller than the lower diameter. Under the threaded cooperation between the outer sleeve 301 and the adjusting cap 302, the adjusting cap 302 can compress the clamping piece 3011 at the top of the outer sleeve 301 to retract it when moving downward along the outer sleeve 301, thereby clamping and fixing the inner rod 303. By adjusting the length of the inner rod 303 in the outer sleeve 301, the length of the entire support leg 3 can be adjusted, thereby adjusting the height of the first mounting plate 4 to make it suitable for rock samples of different lengths. A slide 304 is fixed between the bottoms of two adjacent support legs 3, and a slide 304 is also fixed between the bottoms of the other two support legs 3. The bottom of each slide 304 is installed with a ball 305. The sliding connection between the upper shear fixing mechanism 100 and the lower shear torsion mechanism 200 is achieved through the rolling connection between the ball 305 and the lower shear torsion mechanism 200.

[0047] The sample end fixing assembly 1 includes an octagonal plate 101 corresponding to the octagonal through hole 402. The mutual cooperation between the octagonal plate 101 and the octagonal through hole 402 can realize the application of rotation constraint on the clamped and fixed sample, so that the sample will not rotate in the direction of the torque when subjected to torque; two groups of sample outer wall fixing assemblies are slidingly provided on the octagonal plate 101, and each group of the sample outer wall fixing assemblies includes two symmetrically arranged sliding rods 102. The two groups of the sample outer wall fixing assemblies are cross-arranged, and the four sliding rods 102 are symmetrically distributed along the circumference. The bottom of each sliding rod 102 is fixed with an arc-shaped clamping ring 103, and the connecting line of the four clamping rings 103 is a circular structure. , a number of fixing pins 104 are provided on the inner side of the clamping ring 103, and the two relative clamping rings 103 can be driven to move toward or away from each other by moving the sliding rod 102. The circular structure formed by the four clamping rings 103 clamps and fixes the sample from the outside of the hollow sample, and since the position of the clamping ring 103 is adjustable, it can be suitable for samples of different diameters; the octagonal plate 101 is provided with a sliding limit through hole 1011 for the sliding of the sliding rod 102, the sliding rod 102 passes through the sliding limit through hole 1011, and the clamping ring 103 is located below the octagonal plate 101, and two groups of driving components for driving the sliding rod 102 to move are provided between the four sliding rods 102.

[0048] Each set of the driving components includes two mutually perpendicular driving rods 105, the two driving rods 105 are arranged crosswise up and down, and the two driving rods 105 are connected by a fixing block 106, and the fixing block 106 is provided with two mutually perpendicular but non-intersecting circular holes, which can serve as a structure for the two mutually perpendicular driving rods 105; both ends of each driving rod 105 are threaded through the corresponding sliding rod 102, and each sliding rod 102 is provided with two threaded holes for the driving rod 105 to pass through. Each of the drive rods 105 is provided with external teeth 107 at its end. The ends of the two corresponding drive rods 105 of the two drive assemblies are connected by an annular toothed belt 108, which meshes with the external teeth 107. The drive rods 105 include a first screw 1051 and a second screw 1052, each of which rotates in opposite directions. Each of the first screw 1051 and the second screw 1052 is fixedly connected by a connecting shaft 1053, which is rotatably connected to the fixed block 106. The ends of the drive rods 105 are provided with hexagonal recesses, and a rotating rod that matches the hexagonal recess can be used to rotate the drive rods 105. When a driving rod 105 in one of the driving components is rotated, the corresponding driving rod 105 in the other driving component can be driven to rotate synchronously through the annular toothed belt 108. When the driving rod 105 rotates, since the rotation directions of the two parts of the driving rod 105 are opposite, and the two corresponding sliding rods 105 are limited by the sliding rod 105 and the sliding limit hole 1011, the two corresponding sliding rods 105 will move closer to or away from each other along the sliding limit hole 1011, thereby adjusting the distance between the two corresponding clamping rings 103 to achieve clamping and fixing of the outer wall of the hollow sample. A fixing nail 104 is provided on the inner wall of the clamping ring 103. When in use, high-strength water is first applied to the outer wall of the sample, and then when the clamping ring 103 is used to clamp and fix it, the fixing nail 104 can penetrate into the high-strength glue layer, thereby increasing the adhesion between the clamping ring 103 and the sample and reducing the loss of torque transmission.

[0049] The octagonal plate 101 is also slidably provided with a sample inner wall fixing component, the structure of the sample inner wall fixing component is the same as that of the sample outer wall fixing component, but the size is smaller than the sample outer wall fixing component, the sample inner wall fixing component is located on the inner side of the sample outer wall fixing component, and the sliding rod 102 in the sample inner wall fixing component and the sliding rod 102 in the sample outer wall fixing component are staggered along the circumference, the fixing pins 104 on the sample inner wall fixing component are located on the outer walls of the clamping rings 103 corresponding to each other, and the inner wall of the hollow sample can be clamped and fixed by the sample inner wall fixing component.

[0050] Furthermore, the lower shear and torsion mechanism 200 includes an intermediate plate 5 and two side plates 6. Both sides of the top of the intermediate plate 5 are provided with sliding grooves 501 that match the ball bearings 305 installed at the bottom of the slide 304. The sliding connection between the upper shear fixing mechanism 100 and the lower shear and torsion mechanism 200 is achieved through the mutual cooperation between the ball bearings 305 and the sliding grooves 501, thereby reducing the friction resistance during the sliding process. Baffles 502 are also fixed on both sides of the intermediate plate 5. The function of the baffles 502 is to transmit the counter torque to the sample through the slide 304 when the sample is subjected to torque, so as to balance the torque of the sample.

[0051] The two groups of torque applying assemblies 2 are respectively mounted on the two side plates 6; a supporting ring 7 is fixed to the top center of the middle plate 5 through four supporting rods 701, and a torsion disk 8 is rotatably sleeved on the supporting ring 7. The torsion disk 8 is also provided with a first through hole 401 and an octagonal through hole 402 that are connected up and down. A circle of sliding grooves that match the supporting ring 7 are provided on the outer periphery of the first through hole 401. The mutual cooperation between the sliding groove and the supporting ring 7 can support the entire torsion disk 8 and ensure the rotation of the torsion disk 8 in the horizontal direction; the sample end fixing assembly 1 corresponding to the lower shear torsion mechanism 200 is clamped on the The specimen is placed in the octagonal through hole 402, and the installation direction of the specimen end fixing assembly 1 corresponding to the lower shear and torsion mechanism 200 is opposite to the installation direction of the specimen end fixing assembly 1 corresponding to the upper shear and torsion mechanism 100; that is, the clamping ring 103 in the specimen end fixing assembly 1 corresponding to the upper shear and torsion mechanism 100 is located below the first mounting plate 4, and the clamping ring 103 in the specimen end fixing assembly 1 corresponding to the lower shear and torsion mechanism 200 is located above the torsion disk 8. When the specimen is placed between the first mounting plate 4 and the torsion disk 8, the two ends of the specimen can be clamped and fixed by the corresponding clamping rings 103 in the two specimen end fixing assemblies 1.

[0052] Furthermore, the torsion disk 8 is a circular disk structure that is symmetrically cut off on both sides, and two parallel grooves 801 are provided on the two curved sides of the torsion disk 8. The two opposite corners of the two curved sides of the torsion disk 8 are fixed with first fixing columns 802 for fixing the slide rope; the two opposite corners of the two side panels 6 are fixed with first support columns 601 for installing the torque application assembly 2.

[0053] The torque application assembly 2 includes a bottom mounting block 201 fixed on the top of the first support column 601, and an F-shaped support member 202 fixed on the side plate 6. The F-shaped support member 202 includes a vertical rod, on which an intermediate rod and a top rod are vertically fixed. The vertical rod, the intermediate rod and the top rod form an F-shaped structure, and the length of the intermediate rod is greater than that of the top rod. A support column is also fixed between the intermediate rod and the top rod to improve the stability of the F-shaped support member 202.

[0054] The end of the bottom mounting block 201 away from the first support column 601 is fixedly connected to the top of the middle rod of the F-shaped support member 202; a torsion motor 203 is installed on the left and right sides of the bottom mounting block 201, and the two torsion motors 203 have different heights (different output shaft lengths), and a hollow pulley 207 is installed on the output shaft of each torsion motor 203, and a wire groove for winding a sling is opened on the outer wall of the hollow pulley 207; an inverted Z-shaped support column 204 is fixed on the top of the bottom mounting block 201, and a top mounting block 205 is fixed on the top of the inverted Z-shaped support column 204. Two second fixing columns 206 of different heights are fixedly provided between the inverted Z-shaped support column 204 and the bottom mounting block 201 and the top mounting block 205, respectively. One of the second fixing columns 206 is located between the inverted Z-shaped support column 204 and the bottom mounting block 201, and the other second fixing column 206 is located between the inverted Z-shaped support column 204 and the top mounting block 205, so that the two second fixing columns 206 have different heights. The second fixing columns 206 are also used to fix the zip line. A pulley set for connecting the zip line is provided between the bottom mounting block 201, the top mounting block 205 and the F-shaped support member 202.

[0055] The pulley block includes a fixed pulley assembly and a movable pulley assembly. The fixed pulley assembly includes a fixed pulley shaft 208 fixedly mounted between the bottom mounting block 201 and the top mounting block 205. A fixed pulley sleeve 209 is fixedly sleeved on the fixed pulley shaft 208. The cross-section of the fixed pulley sleeve 209 is I-shaped, and the fixed pulley sleeve 209 is fixedly provided with two circles of first sliding clasps 210 along the circumferential direction. The two first sliding clasps 210 are rotatably connected to the hollow pulley 207, and the hollow pulley 207 can rotate around the fixed pulley sleeve 209.

[0056] The movable pulley assembly includes a movable pulley sleeve 211 slidably arranged between the top rod and the middle rod of the F-shaped support 202. The top rod and the middle rod of the F-shaped support 202 are both provided with a sliding groove. The top and bottom of the movable pulley sleeve 211 are fixed with sliding columns matching the sliding groove. The movement of the movable pulley sleeve 211 can be achieved through the mutual cooperation of the sliding groove and the sliding column. The cross section of the movable pulley sleeve 211 is also I-shaped, and the two horizontal A first sliding groove 212 is provided on each part, and a sliding ring 213 is slidably provided in each first sliding groove 212. The sliding ring 213 is fixed with an external protrusion 214 for connecting the slide rope; two circles of second sliding clamping rings 215 are provided on the vertical section of the I-shaped movable pulley sleeve 211, and the two second sliding clamping rings 215 are also rotatably connected to the hollow pulley 207, and the sliding ring 213 and the hollow pulley 207 can both rotate around the movable pulley sleeve 211.

[0057] Furthermore, two different types of slip ropes are connected to the pulley assembly. The first type of slip ropes has two ends, one end of which is connected to the external protrusion 214 of the sliding ring 213, and the other end is connected to the first fixed columns 802 corresponding to each other on the torsion disk 8, and the two first type of slip ropes are respectively clamped in the grooves 801 on the side walls of the torsion disk 8 corresponding to each other; the function of the first type of slip rope is to continue to transmit the force transmitted to the movable pulley assembly to the torsion disk 8, and generate torque on the torsion disk 8 through the force applied to the torsion disk 8, which is further transmitted to the sample end fixing assembly 1 and the rock sample; this method of applying torque by using the slip rope to wrap around an arc on the torsion disk 8 effectively reduces the situation where the rock sample is rotated due to the action of the torque, resulting in the loss of applied force. If the rock sample rotates, but due to the characteristics of the slip rope, the angle between the slip rope and the groove 801 in the torsion disk 8 remains unchanged, then the force arm of the force applied by the slip rope to the torsion disk remains unchanged, and the torque remains unchanged;

[0058] The second type of cable also has two ends, one end of which is connected to a hollow pulley 207 mounted on the output shaft of the torsion motor 203, and the other end of which passes around a corresponding hollow pulley 207 mounted on a movable pulley sleeve 211. (The cable between the hollow pulley 207 mounted on the output shaft of the torsion motor 203 and the hollow pulley 207 mounted on the movable pulley sleeve 211 can drive the movable pulley assembly to move when the torsion motor 203 is in operation, thereby driving the first type of cable to transmit force.) The cable then passes around the corresponding hollow pulley 207 mounted on the fixed pulley sleeve 209 to fine-tune the direction of the cable, and is finally fixed to the corresponding second fixed column 206. The two torsion motors 203 are at different heights, connecting two different cables. The parallel connection between the two cables and the movable and fixed pulley assemblies, as well as the torsion disk 8, can improve the stability of the torsion disk 8 during rotation.

[0059] Working principle of the present invention: When the hollow torsional shear test device for rock in the present invention is used, first, strong glue is evenly applied to the inner and outer walls of the two ends of the hollow rock sample to form a glue layer, and then the rock sample is placed between the first mounting plate 4 and the torsion disk 8, and the sample end fixing assemblies 1 corresponding to the upper shear fixing mechanism 100 and the lower shear torsion mechanism 200 are used to fix the two ends of the rock sample respectively, and then the torsion motor 203 is started, and torque is generated on the torsion disk 8 through the connection between the slide rope and the movable pulley assembly and the fixed pulley assembly, and the force is transmitted to the rock sample through the torsion disk 8.

[0060] When fixing the rock sample, the outer wall of the hollow rock sample is placed on the inner side of the four clamping rings 103 corresponding to the outer wall fixing assembly of the sample, and the inner wall of the hollow rock sample is located on the outer side of the four clamping rings 103 corresponding to the inner wall fixing assembly of the sample. Then, the driving rod 105 is rotated by the tool to drive the sliding rod 102 and the clamping ring 103 to slide toward the side close to the outer wall or inner wall of the rock sample, so that the fixing nail 104 is inserted into the corresponding strong glue layer, thereby clamping and fixing the outer wall and inner wall of the rock sample respectively.

[0061] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A hollow torsional shear testing device for rock, comprising an upper shear fixing mechanism (100) and a lower shear torsional mechanism (200), characterized in that: The upper shear fixing mechanism (100) is slidably connected to the lower shear torsion mechanism (200), and both the upper shear fixing mechanism (100) and the lower shear torsion mechanism (200) are provided with a sample end fixing assembly (1) for clamping and fixing the hollow rock sample. The lower shear torsion mechanism (200) is also fixed with two sets of torque applying assemblies (2), and the torque applying assemblies (2) use a pulley group method combining a fixed pulley and a movable pulley to apply torque to the hollow rock sample. The lower shearing and torsion mechanism (200) comprises an intermediate plate (5) and two side plates (6), the upper shearing and torsion mechanism (100) is slidably mounted on the intermediate plate (5), and the two groups of the torque applying assemblies (2) are respectively mounted on the two side plates (6); a support ring (7) is fixedly provided at the top center of the intermediate plate (5), a torsion disk (8) is rotatably sleeved on the support ring (7), and the torsion disk (8) is also provided with a first through hole (401) and an octagonal through hole (402) that are connected up and down, and the sample end fixing assembly (1) corresponding to the lower shearing and torsion mechanism (200) is clamped in the octagonal through hole (402), and the installation direction of the sample end fixing assembly (1) corresponding to the lower shearing and torsion mechanism (200) is opposite to the installation direction of the sample end fixing assembly (1) corresponding to the upper shearing and torsion mechanism (100); first support columns (601) for mounting the torque applying assembly (2) are fixedly provided at two opposite corners of the two side plates (6); The torque applying assembly (2) comprises a bottom mounting block (201) fixedly mounted on the top of the first support column (601), and an F-shaped support member (202) fixedly mounted on the side plate (6), wherein one end of the bottom mounting block (201) away from the first support column (601) is fixedly connected to the top of the middle rod of the F-shaped support member (202); a torsion motor (203) is mounted on both the left and right sides of the bottom mounting block (201), the two torsion motors (203) have different heights, and a hollow pulley (203) is mounted on the output shaft of each torsion motor (203). 07); an inverted Z-shaped support column (204) is fixedly provided on the top of the bottom mounting block (201); a top mounting block (205) is fixedly provided on the top of the inverted Z-shaped support column (204); two second fixing columns (206) of different heights are fixedly provided between the inverted Z-shaped support column (204), the bottom mounting block (201) and the top mounting block (205), respectively; the second fixing columns (206) are also used to fix the sliding rope; a pulley block for connecting the sliding rope is provided between the bottom mounting block (201), the top mounting block (205) and the F-shaped support member (202); The torsion disk (8) is a circular disk structure with two symmetrical cutouts on both sides, and two parallel grooves (801) are provided on the two arc-shaped side surfaces of the torsion disk (8), and first fixing columns (802) for fixing the sliding rope are fixed on the two opposite corners of the two arc-shaped side surfaces of the torsion disk (8); The pulley assembly includes a fixed pulley assembly and a movable pulley assembly, wherein the fixed pulley assembly includes a fixed pulley shaft (208) fixedly arranged between the bottom mounting block (201) and the top mounting block (205), a fixed pulley sleeve (209) fixedly sleeved on the fixed pulley shaft (208), the cross section of the fixed pulley sleeve (209) being I-shaped, and the fixed pulley sleeve (209) being fixedly provided with two circles of first sliding clasps (210) along the circumferential direction, and the two first sliding clasps (210) are both rotatably connected to the hollow pulley (207); The movable pulley assembly includes a movable pulley sleeve (211) slidably arranged between the top rod and the middle rod of the F-shaped support member (202), the cross-section of the movable pulley sleeve (211) is also I-shaped, and first sliding grooves (212) are provided on both horizontal parts of the I-shaped movable pulley sleeve (211), and a sliding ring (213) is slidably provided in each of the first sliding grooves (212), and an external hanging protrusion (214) for connecting a sliding rope is fixed on the sliding ring (213); two circles of second sliding clasps (215) are provided on the vertical section of the I-shaped movable pulley sleeve (211), and the two second sliding clasps (215) are also rotatably connected to the hollow pulley (207); Two different types of sliding ropes are connected to the pulley assembly. The first type of sliding ropes has two ends, one end of which is connected to the external protrusion (214) of the sliding ring (213), and the other end is connected to the first fixed columns (802) corresponding to each other on the torsion disk (8), and the two first type of sliding ropes are respectively clamped in the grooves (801) on the side walls of the torsion disk (8) corresponding to each other; The second type of pulley also has two ends, one end of which is connected to the hollow pulley (207) installed on the output shaft of the torsion motor (203), and the other end passes around the hollow pulley (207) installed on the corresponding movable pulley sleeve (211), and then passes around the hollow pulley (207) installed on the corresponding fixed pulley sleeve (209), and finally fixed to the corresponding second fixed column (206).

2. A hollow torsional shear testing device for rock according to claim 1, characterized in that: The upper shear fixing mechanism (100) comprises four retractable support legs (3), a first mounting plate (4) is fixed on the top of the four support legs (3), a circular first through hole (401) is opened at the center of the first mounting plate (4), an octagonal through hole (402) is opened at the top of the first through hole (401), the inscribed circle diameter of the octagonal through hole (402) is larger than the diameter of the first through hole (401), a sample end fixing assembly (1) corresponding to the upper shear fixing mechanism (100) is clamped in the octagonal through hole (402), and the bottom of the sample end fixing assembly (1) passes through the first through hole (401).

3. The hollow torsional shear testing device for rock according to claim 2, characterized in that: The sample end fixing assembly (1) includes an octagonal plate (101) corresponding to the octagonal through hole (402), two groups of sample outer wall fixing assemblies are slidably provided on the octagonal plate (101), each group of the sample outer wall fixing assemblies includes two symmetrically arranged sliding rods (102), and an arc-shaped clamping ring (103) is fixed to the bottom of each sliding rod (102), and the connecting line of the four clamping rings (103) is a circular structure, and a plurality of fixing pins (104) are provided on the inner side of the clamping ring (103); a sliding limit through hole (1011) for sliding the sliding rod (102) is opened on the octagonal plate (101), the sliding rod (102) passes through the sliding limit through hole (1011), and the clamping ring (103) is located below the octagonal plate (101), and two groups of driving assemblies for driving the sliding rod (102) to move are provided between the four sliding rods (102).

4. The hollow torsional shear testing device for rock according to claim 3, characterized in that: Each group of the driving components includes two mutually perpendicular driving rods (105), the two driving rods (105) are arranged crosswise up and down, and the two driving rods (105) are connected by a fixed block (106), both ends of each driving rod (105) are threaded through the corresponding sliding rod (102), and the end of each driving rod (105) is fixed with external teeth (107), and the ends of the two corresponding driving rods (105) of the two groups of driving components are connected by an annular toothed belt (108), and the annular toothed belt (108) and the external teeth (107) are meshed with each other; The driving rod (105) comprises a first screw rod (1051) and a second screw rod (1052) with opposite rotation directions, each of the first screw rod (1051) and the second screw rod (1052) being fixedly connected via a connecting shaft (1053), and the connecting shaft (1053) is rotationally connected to the fixed block (106).

5. The hollow torsional shear testing device for rock according to claim 3, characterized in that: The octagonal plate (101) is also provided with a sliding sample inner wall fixing assembly, the sample inner wall fixing assembly has the same structure as the sample outer wall fixing assembly, but is smaller in size than the sample outer wall fixing assembly; and the sliding rod (102) in the sample inner wall fixing assembly and the sliding rod (102) in the sample outer wall fixing assembly are staggered along the circumference, and the fixing pins (104) on the sample inner wall fixing assembly are located on the outer walls of the corresponding clamping rings (103).

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