Bearing system for rock mechanics test under high temperature and high pressure multi-field coupling in deep earth

A bearing system for rock mechanics test under high temperature and high pressure multi-field coupling includes a force sensor lifting seat and a jack. The force sensor lifting seat includes a connecting disk connected with the jack, a support disk, and an operation channel. A groove dented downwards is arranged on the connecting disk, the support disk is disposed in the groove and freely propped upon the connecting disk; through holes of the connecting disk and the support disk form a control operation channel; and a limiting device is arranged for preventing an MTS triaxial force sensor from disengaging from the support disk. A bolt hole of the force sensor can be aligned with a mounting hole on a solid steel column by rotating the connecting disk for convenient and accurate bolting.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority to Chinese Patent Application No. 201810401506.1, filed on Apr. 28, 2018 the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The invention belongs to the field of rock mechanics test of engineering rock masses, in particular to a bearing system for dismounting and mounting an MTS high temperature and high pressure triaxial force sensor.

BACKGROUND

Rock mechanics triaxial tests at high temperature and high pressure are necessary basic tests for all kinds of rock engineering in deep earth. Therefore, reliable tests are of great significance for rock engineering construction. In practical tests, accuracy and reliability of test results are compromised by inevitable damages to force sensors working as core member in laboratory high temperature and high pressure triaxial tests. Therefore, the force sensors are required be checked, maintained and replaced at a regular interval. The MTS rock mechanics test system is one of the world's most advanced rock mechanics equipment. The high temperature and high pressure force sensor, its core structure, relates to high-precision technology, high price and heavy mass, while the high temperature and high pressure triaxial chamber where the sensor is arranged is special in structure and narrow in space. With the possible unstable suction force between the high temperature and high pressure sensor and the upper connector, and precise row lines (e.g. load, deformation, seepage and temperature) densely arranged on the base of the high temperature and high pressure triaxial chamber there below, it is difficult to dismount and mount the high temperature and high pressure sensor. Improper dismounting and mounting are likely to lead to damages to the sensor and the row lines on the triaxial chamber base, injuries and other major property losses and personal injuries. To address the problem, the conventional method is to manually lift the triaxial force sensor and dismount/mount the sensor with the cooperation of multiple people. The method allows a short time for lifting with lots of labor and the sensor is possibly shaking during the process. Therefore, the method is low in accuracy and slow in the process of dismounting and mounting, and dismounting and mounting risks still exist. Currently, there is no special equipment effectively solving the problem of dismounting and mounting the high temperature and high pressure sensor.

SUMMARY

The technical problem to be solved by the invention is to provide a bearing system for rock mechanics test under high temperature and high pressure multi-field coupling in deep earth, in order to improve mounting and dismounting efficiency, safety and stability of an MTS high temperature and high pressure triaxial force sensor.

The technical solution of the invention is a bearing system for rock mechanics test under high temperature and high pressure multi-field coupling in deep earth, comprising a high temperature and high pressure force sensor lifting seat and a jack propped upon an MTS hydraulic servo table and configured to lift the force sensor lifting seat:

The force sensor lifting seat comprises a connecting disk connected with the jack, a support disk configured to support an MTS triaxial force sensor and an operation channel for dismounting and mounting the MTS triaxial force sensor; a groove dented downwards is arranged above the connecting disk, the support disk is disposed in the groove and freely propped upon the connecting disk, and the support disk is radially limited by side walls of the groove; both the connecting disk and the support disk are in an annular shape with a through hole arranged at the middle, and the through holes of the connecting disk and the support disk form a control operation channel; and a limiting device is arranged to prevent the MTS triaxial force sensor from disengaging from the support disk.

Furthermore, a flange protruding upward is arranged at the middle of the groove in an axial direction thereof, and the flange, an inner wall of the groove and a bottom of the groove are enclosed to form an circular slideway; the flange is peripherally sleeved with a round rod slidable in the slideway (113); and the support disk is freely propped upon the round rod.

Further, the limiting device is a stop collar, and the stop collar is arranged above the connecting disk and detachably connected with the connecting disk; an inner wall of the stop collar and an upper surface of the support disk are enclosed to form an accommodating cavity fitting with the MTS triaxial force sensor; and a locking member is arranged on the stop collar to lock a relative position of the force sensor.

Further, the inner wall of the stop collar extends inwards in the radial direction thereof and protrudes into the groove of the connecting disk; and the support disk is vertically limited by a bottom surface of the protrusion of the stop collar extending inwards.

Further, the locking member is a stop screw radially arranged along the stop collar and running through the stop collar, and the stop screw and the stop collar are in threaded connection.

Further, the jack comprises a bottom pedestal, a top support table and a jacking mechanism arranged therebetween and driving the support table to move up and down; the jacking mechanism comprises four transmission rods, and every two of the four transmission rods form an elbowed transmission member, each of the elbowed transmission members is provided with a connecting lug; two transmission rods of each of the elbowed transmission members are hinged with the connecting lug; the two elbowed transmission members are oppositely arranged to form a parallelogram structure with equal side length, one end of the parallelogram structure is hinged with a bottom lug arranged on the pedestal, and the other end thereof is hinged with a top lug arranged on the support table; a connecting lug is provided for every two of the transmission rods; and a threaded rod is arranged diagonally to the parallelogram structure, and the threaded rod and the connecting lug are in threaded connection to drive the elbowed transmission members to stretch and draw back.

Further, the connecting lug is a grooved member with a groove structure for accommodating the corresponding transmission rod; the bottom lug is a grooved member with a groove structure for accommodating the corresponding transmission rod; and the top lug is also a grooved member with a groove structure for accommodating the corresponding transmission rod.

Further, the support table is connected with the connecting disk by means of a group of support rods; these support rods are threaded, nuts fitting with the threads are fixedly attached to an upper surface and a lower surface of the support table, and the support rods run through the support table and are in threaded connection with the nuts on the upper and lower surfaces of the support table.

Further, a plane mirror is arranged on the upper surface of the support table, and the operation channel and an orthographic projection of the plane mirror on the upper surface of the support table are matched; and the plane mirror is hinged to the support table by means of a spherical hinge.

Further, a locating hole fitting with a central alignment pin of the MTS hydraulic servo table is arranged on the pedestal.

The beneficial effects of the invention are as follows: The invention replaces the conventional dismounting and mounting method for force sensors involving the cooperation of multiple people and manual lifting, improves mechanization degree of the dismounting and mounting, provides stable and powerful support for the force sensor, effectively economizes on manpower and reduces risks of dropping the sensor and secondary damages to the sensor that may occur during manual operation; with the fixing effect generated by the stop collar and the stop screw on the connecting disk, a certain pulling force can be applied to the high temperature and high pressure force sensor through the transmission rods or a built-in loading system of the MTS, so as to effectively solve the problem that the force sensor is difficult to be disengaged from the upper connector when a suction force exists therebetween, and make the dismounting of the force sensor safer; the groove dented downwards is arranged on the connecting disk, the support disk is arranged in the groove and freely propped upon the connecting disk, and the support disk is radially limited by the side walls of the groove, so the support disk can only rotate around the axis thereof; as a result, a bolt hole of the force sensor can be aligned with a mounting hole on a solid steel column by rotating the support disk for convenient and accurate bolting, shortened alignment process and improved mounting efficiency.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention will be further described in combination with drawings and embodiments:

As shown inFIGS. 1 to 3, a bearing system for rock mechanics test under high temperature and high pressure multi-field coupling in deep earth, comprises a force sensor lifting seat1and a jack2propped upon an MTS hydraulic servo table5and configured to lift the force sensor lifting seat1;

The force sensor lifting seat1comprises a connecting disk11connected with the jack2, a support disk12configured to support an MTS triaxial force sensor6and an operation channel13for dismounting and mounting the MTS triaxial force sensor6; a groove111dented downwards is arranged above the connecting disk11, the support disk12is disposed in the groove111and freely propped upon the connecting disk11, and the support disk12is radially limited by side walls of the groove111; both the connecting disk11and the support disk12are in an annular shape with a through hole arranged at the middle, and the through holes of the connecting disk11and the support disk12form a control operation channel13; and a limiting device is arranged to prevent the MTS triaxial force sensor6from disengaging from the support disk12.

According to the invention, the force sensor lifting seat1is configured to lift the force sensor and propped upon the jack2, and the force sensor is lifted to the mounting position by jacking up the force sensor lifting seat1by means of the jack2, or withdrawn from a rigid column of a triaxial chamber by jacking down the force sensor lifting seat1by means of the jack2.

The connecting disk11of the lifting seat1is connected with the jack2, and the support disk12is configured to support the MTS triaxial force sensor6. The support disk12is freely propped upon the connecting disk11, that is, the support disk12is limited by the underneath connecting disk11to prevent the support disk12from falling vertically. However, there is no connector or the like arranged between the support disk12and the connecting disk11, so they can move relatively in the radial direction or rotate in the axial direction. As the support disk12and the connecting disk11can move relatively, the support disk12arranged in a groove111of the connecting disk11can be radially limited by side walls of the groove111, so as to prevent the support disk12from disengaging from the connecting disk11when the support disk12moves in relative to the connecting disk11in the radial direction, thus the radial movement of the support disk12and the connecting disk11is limited, and the support disk12can only rotate around the axis thereof. As a result, a bolt hole of the force sensor can be aligned with a mounting hole on a solid steel column by rotating the support disk12for convenient and accurate bolting. The control operation channel13is formed by through holes of the connecting disk11and the support disk12. An operator can mount and remove screws through the operation channel13to expand operation space for mounting and dismounting, and avoid interference of related members in the force sensor lifting seat1that exists in the perpendicular mounting process, and eliminate deviations from the mounting position due to contact with the force sensor lifting seat1by the operator. Furthermore, the dismounting and mounting of the force sensor with supporting device rather than manual support save both time and labor; the force sensor is supported in a more stable and powerful manner, a certain pulling force can be applied to the force sensor after the force sensor and the support disk12are limited to effectively solve the problem that the force sensor is difficult to be dismounted in the presence of oil suction force, and to prevent the force sensor from accidental drop or damage.

As shown inFIGS. 1 to 3, to reduce frictional resistance between the connecting disk11and the support disk12, a flange112protruding upward is preferably arranged at the middle of the groove111in the axial direction, and the flange112, an inner wall of the groove111and a bottom of the groove111are enclosed to form an circular slideway113; the flange112is peripherally sleeved with a round rod121slidable in the slideway113; and the support disk12is freely propped upon the round rod121.

The round rod121is arranged between the connecting disk11and the support disk12to reduce friction surface and decrease the friction resistance. The round rod121is radially limited by the flange112, so that the round rod121can rotate in the axial direction around the flange112, and the support disk12is freely propped upon the round rod121to facilitate rotation movement of the support disk12.

The limiting device for preventing the MTS triaxial force sensor6from disengaging from the support disk12can be a hoop encircling the force sensor and connected with the connecting disk11. However, the hoop encircling the force sensor can be mounted on or dismounted from the force sensor in the same procedure. As the hoop and the force sensor have large contact area, the probability of damaging the force sensor rises with the increased collision probability when they are mounted and dismounted.

As a preferred embodiment, as shown inFIGS. 1 and 3, the limiting device is a stop collar14, and the stop collar14is arranged above the connecting disk11and detachably connected with the connecting disk11; an inner wall of the stop collar14and an upper surface of the support disk12are enclosed to form an accommodating cavity15fitting with the MTS triaxial force sensor6; and a locking member is arranged on the stop collar14to lock a relative position of the sensor.

To avoid uneven pressure on the support disk12by the force sensor, which leads to an upturned end of the support disk12and deviation of the force sensor axis from the mounting position, the inner wall of the stop collar14preferably extends inwards in the radial direction and protrudes into the groove111of the connecting disk11; and the support disk12is vertically limited by the bottom surface of the protrusion extending inwards of the stop collar14.

The locking member can be a sucker or the like, but sucking stability of the sucker depends on flatness of the force sensor surface and other factors. Preferably, the locking member is a stop screw141radially arranged along the stop collar14and running through the stop collar14, and the stop screw141and the stop collar14are in threaded connection. The stop screw141has characteristics of low cost, easy operation and strong adaptability.

As shown inFIG. 1, the jack2preferably comprises a bottom pedestal21, a top support table22and a jacking mechanism arranged therebetween and driving the support table22to move up and down; the jacking mechanism comprises four transmission rods23, and every two of the four transmission rods23form an elbowed transmission member; each of the elbowed transmission members is provided with a connecting lug24; two transmission rods23of each of the elbowed transmission members are hinged with the connecting lug24; the two elbowed transmission members are oppositely arranged to form a parallelogram structure with equal side length, one end of the parallelogram structure is hinged with a bottom lug25arranged on the pedestal21, and the other end thereof is hinged with a top lug26arranged on the support table22; a connecting lug24is provided for every two of the transmission rods23; and a threaded rod27is arranged diagonally for the parallelogram structure, and the threaded rod27and the connecting lug24are in threaded connection to drive the elbowed transmission members to stretch and draw back.

The force sensor lifting seat1is lifted up and down by rotating the threaded rod27. The operation is simple and easy to be controlled, so the force sensor rises and falls conveniently and efficiently. The threaded rod27can be manually driven or electrically driven.

Preferably, the connecting lug24is a grooved member with a groove structure for accommodating the corresponding transmission rod23; the bottom lug25is a grooved member with a groove structure for accommodating the corresponding transmission rod23; and the top lug26is also a grooved member with a groove structure for accommodating the corresponding transmission rod23. The connecting lug24, the bottom lug25and the top lug26can be members in various shapes, but grooved member provides greater strength.

The support table22is able to be directly connected with the connecting disk11, providing that a specified lifting range is achieved and the specification of the jack meets requirements. Preferably, the support table22is connected with the connecting disk11by means of a group of support rods3; the support rods3are threaded, nuts31fitting with the threads are fixedly attached to an upper surface and a lower surface of the support table22, and the support rods3run through the support table22and are in threaded connection with the nuts31.

The support table22and the connecting disk11are connected by means of the support rod3and the nuts31, so that another lifting structure is formed between the support table22and the connecting disk11. Therefore, the requirements for specification of the jack2can be lowered. Once the support disk12deviates from the horizontal position, it can be centered by slightly adjusting the support rod3and the nuts31.

To conveniently observe positions of a limiting hole and a center hole on the bottom of the force sensor in the triaxial chamber, centering adjustment is directed to simplify the dismounting and mounting of the force sensor. As shown inFIG. 1, a plane mirror4is preferably arranged on the upper surface of the support table22, and the operation channel13and an orthographic projection of the plane mirror4on the upper surface of the support table22are matched; and the plane mirror4is hinged to the support table22by means of a spherical hinge.

The plane mirror4is hinged to the support table22by means of the spherical hinge, so that the plane mirror4can pitch and rotate as required.

To mount the device by using the structure of the MTS test system, as shown inFIG. 1, a locating hole211fitting with a central alignment pin of an MTS hydraulic servo table5is preferably arranged on the pedestal21. When the device aligns with the MTS hydraulic servo table5and is fixed by bolts, on the one hand, the force sensor can be lifted up and down by lifting the device up and down, and on the other hand, the device and the force sensor can be lifted up and down together by a built-in loading system of the MTS if lifting motion of the device is limited.