Patent ID: 12203899

Reference signs:1, first positioning stage:2, second positioning stage:3, first support piece:4, second support piece:5, screw drive mechanism:6, cushion block:7, rock mass mounting area:8, first thread segment:9, second thread segment:10, screw:11, nut seat:12, bearing housing:13, slide rail:14, upright post:15, support plate:16, glue blocking mechanism:17, fixed cylinder:18, telescopic rod:19, semicircular positioning plate:20, semicircular rubber sleeve:21, elastic mechanism:22, guide cylinder:23, connecting rod:24, spring:25, operating table:26, positioning cylinder:27, support:28, driving equipment:29, adjusting handwheel:30, screw:31, annular retaining ring:32, self-lubricating guide sleeve:33, leveling leg:34, lifter.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following clearly and completely describes the technical solutions in the embodiments of the present disclosure with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present disclosure.

The purpose of the present disclosure is to provide a sample mounting device for direct tensile test of rock mass to solve the problems in the prior art. The centering and alignment of the rock mass and the cushion block are achieved through the cooperation of the coaxially arranged cushion blocks, the first support piece, and the second support piece, so as to improve the accuracy of the test.

In order to make the above purpose, features and advantages of the present disclosure more apparent and easy to understand, the present disclosure is further described in detail below with reference to the accompanying drawings and embodiments.

As shown inFIGS.1to8, a sample mounting device for direct tensile test of rock mass is provided, which includes a first positioning stage1, a second positioning stage2, a first support piece3, a second support piece4, and a screw drive mechanism5. The second positioning stage2is arranged above the first positioning stage1and capable of moving up and down through an adjusting mechanism, and cushion blocks6for gluing with the rock mass are coaxially and detachably arranged at opposite ends of the first positioning stage1and the second positioning stage2. A diameter of the cushion blocks6is not less than that of the rock mass. Specifically, opposite surfaces of the first positioning stage1and the second positioning stage2are formed with grooves in fit with the cushion blocks6, and the cushion blocks6are inserted into the grooves. By increasing the friction force between the grooves and the cushion blocks6, it is ensured that the upper cushion block6will not detach from the groove under the influence of the gravity. The rock mass mounting area7is formed between the cushion block6of the first positioning stage1and the cushion block6of the second positioning stage2. The upper and lower cushion blocks6are positioned through the second positioning stage2and the first positioning stage1, respectively, making the two cushion blocks6coaxially aligned.

The screw10of the screw drive mechanism5includes a first screw segment8and a second screw segment9with opposite thread directions. The first support piece3is connected with the first screw segment8through the nut seat11, and the second support piece4is connected with the second screw segment9through the nut seat11. Support end surfaces of the first support piece3and the second support piece4are opposite to each other. The first support piece3and the second support piece4are symmetrically arranged on both sides of the rock mass mounting area7. The first support piece3and the second support piece4are driven through the screw10with two opposite thread segments to synchronously move in opposite directions, thus stably support the rock mass between the two cushion blocks6in a clamping manner. As the first support piece3and the second support piece4are symmetrically arranged and move synchronously, the rock mass is just located in the rock mass mounting area7when being supported, achieving the centering and alignment of the rock mass and the cushion blocks6, and conducive to improving the accuracy of the subsequent tensile test.

Each of the first support piece3and the second support piece4includes an upright post14, and a support plate15. The support plate15is horizontally arranged, and an end surface, close to the rock mass mounting area7, of the support plate15is the support end surface. One end of the upright post14is fixedly connected with the nut seat11by a bolt, and another end of the upright post14is connected with the support plate15by a bolt. Compared with welding, the bolt connection method can improve the convenience of assembling and disassembling. In order to improve the clamping and support effect on the rock mass, the support end surface of the support plate15is V-shaped.

The upright post14may be of a cylindrical structure, or a plate-shaped structure, and so on.

Multiple support plates15are arranged on the single upright post14, and the multiple support plates are arranged at intervals from top to bottom, so as to improve the contact area with the rock mass and reduce damage to the rock mass caused by stress concentration.

The multiple support plates15can be jointly welded or bolted to a vertically arranged connection plate to form a module, and the connection plate is further connected with the upright post14by a bolt.

Since the rock mass may be with a certain inclination during initial placement of the rock mass, glue between the rock mass and the cushion block6is partly squeezed out when the rock mass is pressed against the lower cushion block6, such that an upper surface of the whole glue layer is inclined. Therefore, during the rock mass is supported, there may be a movement state in which the lower end of an originally inclined bottom of the rock mass is lifted upward and the higher end of the originally inclined bottom of the rock mass is pressed downward. In such a movement state, a glue-free area is formed at the lower end that is lifted upward, and the glue below the higher end that is pressed downward cannot be filled into the glue-free area completely, which affects the uniformity of glue distribution between the cushion blocks6and the rock mass, and further affects the accuracy of the subsequent tensile test. Therefore, each glue blocking mechanism16is arranged on a corresponding upright post14. The glue blocking mechanism16includes a fixed cylinder17, a telescopic rod18, a semicircular positioning plate19, and a semicircular rubber sleeve20. Both the semicircular positioning plate19and the semicircular rubber sleeve20are made of materials that are not easily bonded to epoxy resin. For example, the semicircular rubber sleeve20is made of silicone rubber, and the semicircular positioning plate19is made of polyethylene, polytetrafluoroethylene, etc. An outer diameter of the telescopic rod18is in fit with an inner diameter of the fixed cylinder17. One end of the telescopic rod18is slidably arranged in the fixed cylinder17, and the other end of the telescopic rod18is fixedly connected with the semicircular positioning plate19. The fixed cylinder17is fixedly connected with the upright post14by a bolt, and the semicircular rubber sleeve20is connected to or integrally formed on the top of the semicircular positioning plate19. One end, away from the telescopic rod18, of the fixed cylinder17is fixedly connected with the upright post14, the glue blocking mechanisms16are symmetrically arranged on the two upright posts14, the two semicircular positioning plates19are jointed to form a cylindrical barrel in fit with the cushion block6, and the two semicircular rubber sleeves20are jointed to form a glue blocking barrel with an inverted frustum-shaped cavity. A small-diameter end of the inverted frustum-shaped cavity is flush with a glued surface of the cushion block6, and a diameter of the small-diameter end of the inverted frustum-shaped cavity is in fit with that of the cushion block6. The working principle is as follows: before support, the telescopic rods18on both sides are controlled to extend to make two semicircular positioning plates19jointed on a peripheral side of the cushion block6. In this case, the inverted frustum-shaped cavity is located on an upper surface of the cushion block6, and then glue is coated on the cushion block6. In the process of placing the rock mass after finishing coating, due to the block of the inverted frustum-shaped cavity, the squeezed glue remains at the bottom of the inverted frustum-shaped cavity instead of losing, such that when a glue-free area is formed in the subsequent support process, the remained glue can be filled into the glue-free area, thus improving the uniformity of the glue layer and improving the accuracy of the subsequent tensile test. As the fixed cylinder17and the telescopic rod18are formed as a freely telescoping structure, a jointing state of the two semicircular positioning plates19cannot be affected during the support movement.

The support plate15is connected with a side wall of the upright post14through an elastic mechanism21. The elastic mechanism21includes a guide cylinder22, a connecting rod23, and a spring24. The connecting rod23is slidably arranged in the guide cylinder22in the axial direction, and one end, away from the connecting rod23, of the guide cylinder22is fixedly connected with the upright post14by a bolt. One end, away from the guide cylinder22, of the connecting rod23is fixedly connected with the support plate15by a bolt, and a spring24is arranged between the connecting rod23and an inner bottom wall of the guide cylinder22. Without support, the spring24is in a normal state. The spring24is provided to ensure that the spring react on the upright post14and the nut seat11while providing the support effect, such that the threads of the nut seat11can be closely attached to the threads of the screw10, thus eliminating the influence of the thread clearance on the support effect.

In order to prevent the connecting rod23from falling out from the guide cylinder22, annular flanges can be arranged at a port of the guide cylinder22, close to the connecting rod23and at a portion of the connecting rod23, located in the guide cylinder22. The annular flange of the guide cylinder22is located on a movement path of the annular flange of the connecting rod23to block the connecting rod23and prevent it from falling off. After the annular flanges are arranged, the annular flange of the connecting rod23needs to fit with the inner diameter of the guide cylinder22.

On the basis of providing multiple support plates15, the connection plate connected with the multiple support plates15is threaded with an end of the connecting rod23, and multiple elastic mechanisms can be arranged between the connecting rod and the upright post14.

In a method of making a pitch of the first thread segment8and the second thread segment9close to a middle of the screw10less than a pitch of the first thread segment8and the second thread segment9close to ends of the screw10, the movement speed at the initial stage of the support movement can be improved, which is helpful to save time and improve efficiency. The change of pitch is gradual, that is, the pitch decreases gradually from the end to the middle.

The sample mounting device for a direct tensile test of rock mass further includes an operating table25. The screw drive mechanism5is horizontally arranged on the operating table25, and the first positioning stage1is fixedly arranged on the operating table25, and arranged corresponding to the middle of the screw10. The second positioning stage2is arranged in the positioning cylinder26and capable of sliding up and down. The positioning cylinder26is fixedly arranged on the operating table25through a support27, and an adjusting mechanism for adjusting a position of the second positioning stage2is arranged on the positioning cylinder26.

The screw drive mechanism5includes a screw10, a nut seat11, a bearing housing12, and a driving equipment28. The screw10is arranged on the operating table25through the bearing housing12, the nut seat11is threaded with the screw10, and the driving equipment28is in drive connection with the screw10. In order to save the cost, the driving equipment28may be selected as a handwheel.

A hole for avoiding the screw10is arranged at the bottom of the first positioning stage1, and through the hole, the first positioning stage is directly buckled to the middle of the screw10.

A slide rail13for guiding the movement of the nut seat11is arranged on the operating table25, and a chute is correspondingly arranged on the nut seat11.

The adjusting mechanism for adjusting the position of the second positioning stage2includes an adjusting handwheel29, and a screw30. A threaded hole is formed in a top of the positioning cylinder26and vertically penetrates through the positioning cylinder26. The screw30is in threaded connection with the threaded hole, the bottom of the screw30is rotatably connected with the second positioning stage, and the top of the screw30is in drive connection with the adjusting handwheel29.

A method of rotary connection between the screw30and the second positioning stage2may be as follows: a bearing is arranged on the top of the second positioning stage2which is rotatably connected with the screw30through the bearing. Alternatively, an annular retaining ring31is fixedly arranged at the bottom of the screw30, and a groove is formed in a side wall of the second positioning stage2. The groove penetrates through the top of the second positioning stage2upwards, and the bottom of the groove is expanded to form a space for accommodating the annular retaining ring31. A width of a notch, corresponding to the top of the second positioning stage2, of the groove is greater than a diameter of the screw30and smaller than an outer diameter of the annular retaining ring31, such that the second positioning stage2can be hung on the screw30by hanging. In order to prevent the screw30from driving the second positioning stage2to rotate synchronously through the annular retaining ring31to affect the uniformity of glue pressing, a vertical strip protrusion can be arranged on a peripheral wall of the second positioning stage2, and a vertical strip slot can be arranged on the positioning cylinder26, and the strip protrusion is arranged in the strip slot and capable of sliding up and down to limit the rotation of the strip slot.

A cover is detachably arranged at the top of the positioning cylinder26. Specifically, the cover at the top is connected with the barrel of the positioning cylinder26by a bolt, thus facilitating the mounting of the second positioning stage2and the screw30.

A self-lubricating guide sleeve32is arranged on an inner wall of the positioning cylinder26to reduce the friction force between the positioning cylinder26and the second positioning stage2.

Leveling legs33are arranged at four corners of a bottom of the operating table25. The leveling legs33can employ bolt legs, and levelness of the whole operating table25can be adjusted by screwing the bolt let at each corner.

A pressure sensor is arranged on the support end surface of the first support piece3or the second support piece4to detect pressure when the rock mass is supported. The pressure sensor is electrically connected with a control system, and the control system is electrically connected with an audible and visual alarm. When the pressure is large, the audible and visual alarm gives an alarm to avoid crushing damage to the rock mass.

During actual application, cushion blocks6are mounted on the first positioning stage1and the second positioning stage2, and glue is coated on the cushion block6of the first positioning stage1, then the rock mass is placed on the cushion block6of the first positioning stage1, the screw10is driven to rotate through the handwheel, and the nut seat11moves synchronously to drive the first support piece3and the second support piece4to clamp and support the rock mass, and the glue is coated on the top of the rock mass or the cushion block6of the second positioning stage2after the support is completed. The adjusting handwheel29is turned to control the second positioning stage2to move downwards till to form a connecting glue layer with the rock mass. Finally, after the glue solidifies, the adjusting handwheel29is turned to control the second positioning stage2to move upwards, and the handwheel is turned to control the first support piece3and the second support piece4to move reversely, thus pulling out the rock mass connected with the cushion block6from the first positioning stage1.

Embodiment 2

As shown inFIG.9, a difference between Embodiment 2 and Embodiment 1 is that the lifter34is arranged on the nut seat11, and the lifter may employ an electric lifter. A lifting end of the lifter34is fixedly connected with the first support piece3or the second support piece4, and a fixed end is fixedly connected with the nut seat11. After the rock mass is clamped by the first support piece3and the second support piece4, the lifter34can control a distance between the rock mass and the cushion block6on the first positioning stage1through the lifting movement, while a distance between the cushion block6on the second positioning stage2and the rock mass can be controlled through the adjusting handwheel29, thus controlling the thickness of the glue layer on both sides of the rock mass.

Adaptive changes made according to actual needs are within the scope of protection of the present disclosure.

It should be noted that it is apparent to those skilled in the art that the present disclosure is not limited to the details of the above exemplary embodiments, and can be realized in other specific forms without departing from the spirit or basic characteristics of the present disclosure. Therefore, the embodiments should be considered as exemplary and non-limiting in all aspects, and the scope of the present disclosure is defined by the appended claims rather than the above description. So it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present disclosure. Any reference signs in the claims should not be regarded as limiting the claims involved.

Specific examples are used in the present disclosure for description of the principles and embodiments of the present disclosure. The description of the above embodiments is merely used to help illustrate the method and its core principles of the present disclosure. Meanwhile, those skilled in the art can make various modifications in terms of specific embodiments and scope of application in accordance with the teachings of the present disclosure. In conclusion, the content of this specification shall not be construed as a limitation to the present disclosure.