Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a crack three-way deformation measuring instrument and a using method thereof.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
A crack three-way deformation gauge comprising:
The telescopic stay bar comprises an inner cylinder body and an outer cylinder body which are coaxially sleeved in a sliding manner, a compression spring is arranged between the inner cylinder body and the outer cylinder body, and a pressure sensor for detecting the real-time elasticity of the compression spring is arranged in the outer cylinder body;
The two groups of mounting rods are symmetrically mounted at two ends of the telescopic supporting rod, the middle part of each mounting rod is vertically provided with a mounting shaft, two ends of each mounting rod are bent towards one side deviating from the mounting shaft, and the end parts of each mounting rod are provided with stable supporting mechanisms;
the movable connecting piece is used for connecting the telescopic supporting rod and the mounting rod, so that the mounting rod and the telescopic supporting rod can rotate at any angle;
The installation shaft is internally provided with a limiting mechanism for limiting the activity of the movable connecting piece, and when the movable connecting piece is limited to move, the two groups of installation rods and the telescopic supporting rods form a stable H-shaped structure.
Preferably, the movable connecting piece comprises a connecting sleeve and a connecting rod, the connecting sleeve is coaxially and rotatably connected with the mounting shaft, the connecting rod is coaxially fixed at the end part of the telescopic supporting rod, a first rotating shaft is radially and penetratingly arranged at the end part of the connecting rod, a connecting ring is rotatably connected on the first rotating shaft, a second rotating shaft perpendicular to the first rotating shaft is arranged on the outer wall of the connecting ring, the second rotating shaft is rotatably connected with the connecting sleeve, and the connecting sleeve, the connecting rod and the connecting ring are in a concentric state;
And the first rotating shaft, the second rotating shaft and the connecting sleeve are provided with angle sensors.
Preferably, the outer wall of the inner cylinder body is uniformly distributed with a plurality of guide strips which are axially arranged, and the inner wall of the outer cylinder body is provided with a plurality of guide grooves which are matched with the guide strips.
Preferably, the inner cylinder body is internally provided with an adjusting ring in a rotating way, the inner cylinder body is internally provided with a gasket in a sliding way, one side of the gasket abuts against the compression spring, the other side of the gasket is fixedly connected with a threaded rod, and the threaded rod is in threaded connection with the center of the adjusting ring.
Preferably, the outer peripheral surface of the gasket is provided with a plurality of limit strips, and the inner wall of the inner cylinder body is provided with a plurality of limit grooves matched with the limit strips.
Preferably, the stable supporting mechanism comprises a mounting plate fixedly mounted at the end part of a mounting rod, two sleeves are vertically arranged on the mounting plate, fixing nails are arranged in the sleeves in a sealing sliding manner, two groups of flow channels are arranged in the mounting rod, two ends of the flow channels are respectively connected with the sleeves through guide pipes, and the sleeves at two ends of the same mounting rod and the flow channels form a sealing cavity.
Preferably, the limiting mechanism comprises a rectangular sliding block axially arranged in the mounting shaft in a sliding way, a sliding port is formed in the mounting rod, the sliding port vertically cuts off the flow channel, a plugging block which is sealed and slides with the sliding port is fixedly arranged on the side wall of the rectangular sliding block, and a connecting hole corresponding to the flow channel is formed in the plugging block;
A limiting rod is fixedly arranged on one side, far away from the plugging block, of the rectangular sliding block, hexagonal limiting holes are formed in the centers of the connecting sleeve and the connecting rod, and two limiting blocks respectively corresponding to the connecting sleeve and the connecting rod are arranged on the limiting rod;
The installation shaft is provided with a driving pin for driving the rectangular sliding block to move in a sliding manner, when the rectangular sliding block moves to the limit position on one side of the limit rod, the connecting hole is communicated with the flow channel, the limiting block is clamped with the limit hole, and when the rectangular sliding block moves to the limit position on one side of the plugging block, the connecting hole is misplaced with the flow channel, and the limiting block is separated from the limit hole.
Preferably, the driving pin comprises two vertical parts and an inclined part, the two vertical parts are respectively aligned with the two end faces of the inclined part, a through hole is formed in the rectangular sliding block in a penetrating mode, the driving pin penetrates through the through hole, a first wedge block and a second wedge block are respectively installed on the two inner walls of the through hole, the inclined face of the first wedge block faces upwards, the inclined face of the second wedge block faces downwards, the planes of the first wedge block and the second wedge block coincide, and the distance between the two end parts of the first wedge block and the second wedge block is consistent with the width of the driving pin.
The use method of the crack three-way deformation measuring instrument is that the crack three-way deformation measuring instrument is used for measuring, and the method comprises the following steps:
s1: the instrument is installed, the movable connecting piece is movably limited through the limiting mechanism, so that the two groups of installation rods and the telescopic supporting rod form a stable H-shaped structure, the telescopic supporting rod is compressed to enable the whole instrument to be placed in a crack, the telescopic supporting rod is kept perpendicular to the crack, the telescopic supporting rod is loosened after the instrument is placed in the crack, the compression spring is stretched, the fixing nails at the end parts of the two groups of installation rods are propped against the inner wall of the crack, when the fixing nails are propped against the inner wall of the crack, the fixing nails slide in the sleeve to adapt to the inner wall of the crack, and the limiting mechanism is controlled to release the limitation on the movable connecting piece until all the fixing nails are stably contacted with the inner wall of the crack, and meanwhile, the runner is cut off, so that the fixing nails are kept stable;
And controlling the gasket to move by rotating the adjusting ring, and presetting the reading of the pressure sensor in the state as an initial value.
S2: after the tester is installed, the deformation condition of the crack is analyzed by monitoring the numerical changes of the pressure sensor and each angle sensor through the remote equipment;
S3: and calculating the numerical value, namely obtaining the length change of the telescopic stay rod according to the absolute value of the numerical value change of the pressure sensor and the stiffness coefficient of the compression spring, wherein the numerical value change of the angle sensor can obtain the angle change of the telescopic stay rod in all directions, and obtaining the components of the telescopic amount of the telescopic stay rod in all directions, namely the deformation amount of the corresponding crack in all directions.
Compared with the prior art, the invention has the following advantages:
1. According to the invention, the telescopic stay bars and the mounting bars are arranged, the internal stay type mounting design in the crack is adopted, the deformation data of the crack is monitored, the influence of drilling mounting on a test result is eliminated, and the influence of the new crack on the data when the new crack appears between anchor points is eliminated.
2. According to the invention, the limit mechanism is arranged, so that the mounting rod and the telescopic stay rod are ensured to be in a vertical state when the measuring instrument is mounted, the fixing nails can be telescopic and adapted to the uneven wall surface of the inner wall of the crack, the state of being vertical to the crack when the telescopic stay rod is mounted is ensured, the test accuracy is improved, the comparability of data in a monitoring period is ensured, and the deformation condition of the crack is better captured. After the installation is completed, the limit to the movable connecting piece is canceled, so that the telescopic stay bar can move in any direction, and the deformation of different positions of the crack is monitored. And meanwhile, the position of the fixed needle is locked, so that the influence of the position change of the mounting rod on data monitoring is prevented.
3. According to the invention, through arranging the movable connecting piece, the mounting rod and the telescopic supporting rod can rotate at any angle, the rotation angles between the mounting rod and the telescopic supporting rod are recorded by matching with a plurality of angle sensors, and crack deformation conditions under different conditions can be analyzed. By combining the length change of the telescopic stay rod, the displacement components in all directions can be obtained, and the specific displacement value of the deformation in all directions can be obtained.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.
Referring to fig. 1 to 10, a crack three-way deformation measuring instrument comprises a telescopic stay bar 1, two groups of mounting bars 2 and a movable connecting piece 3.
As shown in fig. 8, the movable connecting piece 3 is used for connecting the telescopic supporting rod 1 and the mounting rod 2, so that the mounting rod 2 and the telescopic supporting rod 1 can rotate by any angle, the telescopic supporting rod 1 is supported in a crack, the mounting rod 2 is propped against the inner wall of the crack and keeps stable, the deformation of the crack acts on the mounting rod 2 and is fed back to the telescopic supporting rod 1, the deformation condition of the crack is reflected through the length change of the telescopic supporting rod 1 and the angle change between the telescopic supporting rod 1 and the mounting rod 2, the deformation data of the crack are monitored by adopting the internal supporting type mounting design in the crack, the influence of the drilling mounting on the test result is eliminated because the drilling mounting is not needed, the distance between the two mounting rods 2 is equal to the gap between the cracks to be detected, and no redundant geological structure exists in the middle, so that the influence of the new crack on the data when the new crack appears between anchor points is eliminated.
The telescopic stay bar 1 comprises an inner cylinder 11 and an outer cylinder 12 which are coaxially sleeved in a sliding manner, a compression spring 13 is arranged between the inner cylinder 11 and the outer cylinder 12, the inner cylinder 11 and the outer cylinder 12 are driven to be separated outwards through the elasticity of the compression spring 13, a supporting force is provided when the telescopic stay bar is installed in a crack, a pressure sensor 17 used for detecting the real-time elasticity of the compression spring 13 is arranged in the outer cylinder 12, when the crack is subjected to tensile deformation, the compression spring 13 is deformed, the inner cylinder 11 and the outer cylinder 12 are controlled to axially slide so as to compensate the displacement of the crack, the numerical value of the pressure sensor 17 can be changed, the reading of the pressure sensor 17 is the elasticity of the compression spring 13 due to the fact that the stiffness coefficient of the compression spring 13 is constant, and the length change of the telescopic stay bar 1 can be reflected according to the reading change of the pressure sensor 17.
Two sets of installation poles 2 symmetry are installed in the both ends of flexible vaulting pole 1, and installation axle 21 is installed perpendicularly in the middle part of installation pole 2, and installation axle 21 is used for dock with swing joint 3, and the both ends of installation pole 2 are crooked to deviating from installation axle 21 one side to be provided with stable supporting mechanism at the tip of installation pole 2, make the tip of installation pole 2 can contact with the crack inner wall and support, and through stable supporting mechanism, adaptation crack's unevenness inner wall when can guaranteeing that installation pole 2 tip and crack inner wall contact.
Referring to fig. 1-4, the stable supporting mechanism comprises a mounting plate fixedly mounted at the end of a mounting rod 2, two sleeves 22 are vertically arranged on the mounting plate, fixing nails 23 are arranged in the sleeves 22 in a sealing sliding manner, two groups of flow passages 24 are arranged in the mounting rod 2, two ends of each flow passage 24 are respectively connected with the corresponding sleeve 22 through a guide pipe, so that the sleeves 22 at two ends of the same mounting rod 2 and the flow passages 24 form a sealed cavity, hydraulic oil is filled in the sealed cavity, when the fixing nails 23 at one end of the mounting rod 2 move in the corresponding sleeve 22, the fixing nails 23 at the other end of the mounting rod 2 are driven to stretch out and draw back through the oil pressure of the hydraulic oil, therefore, when the fracture surface is uneven, the mounting rod 2 is pressed against the inner wall of the fracture in a manner parallel to the fracture, one fixing nail 23 at two ends of the mounting rod 2 is firstly contacted with the protruding part of the inner wall of the fracture, the fixing nails 23 are pushed into the sleeves 22 along with the continuous pushing of the mounting rod 2, the internal pressure of the sealed cavity is increased, the fixing nails 23 are driven to be pushed outwards until the fixing nails 23 at the two fixing nails 23 are both contacted with the inner wall of the fracture, the two fixing nails 23 are tightly support the inner wall, when the extending lengths of the two fixing nails 23 are different, the fracture lengths of the two fixing nails 23 can be offset, the fracture lengths of the fracture is not even, and the continuous crack condition can be accurately detected, and the accurate state is guaranteed, and the following detection is guaranteed.
Referring to fig. 1-4, the movable connector 3 includes a connecting sleeve 31 and a connecting rod 32, the connecting sleeve 31 is coaxially and rotatably connected with the mounting shaft 21, the connecting rod 32 is coaxially fixed at the end of the telescopic supporting rod 1, the end of the connecting rod 32 radially penetrates through and is provided with a first rotating shaft 321, the first rotating shaft 321 is rotatably connected with a connecting ring 33, the outer wall of the connecting ring 33 is provided with a second rotating shaft 331 perpendicular to the first rotating shaft 321, the second rotating shaft 331 is rotatably connected with the connecting sleeve 31, the connecting rod 32 and the connecting ring 33 are in concentric states, the diameter of the connecting sleeve 31 is larger than that of the connecting ring 33, the connecting ring 33 can rotate around the first rotating shaft 321, the connecting sleeve 31 can rotate around the second rotating shaft 331, the telescopic supporting rod 1 and the mounting rod 2 at two ends of the movable connector 3 can rotate in two different directions, and in combination with the two rotating directions, the end point of the mounting shaft 21 can actually rotate to any position within a 90 ° range.
Referring to fig. 1 to 7, in order to ensure the accuracy of the initial position when the measuring instrument is installed, a limiting mechanism 4 for limiting the movement of the movable connecting piece 3 is arranged in the installation shaft 21, and when the movable connecting piece 3 is limited to move, two groups of installation rods 2 and the telescopic supporting rods 1 form a stable H-shaped structure.
The limiting mechanism 4 comprises a rectangular sliding block 41 axially sliding in the mounting shaft 21, a sliding port is formed in the mounting rod 2, the sliding port vertically cuts off the flow channel 24, a blocking block 42 sliding in a sealing manner with the sliding port is fixedly arranged on the side wall of the rectangular sliding block 41, a connecting hole 43 corresponding to the flow channel 24 is formed in the blocking block 42, when the connecting hole 43 corresponds to the flow channel 24, the flow channel 24 is communicated, the fixing nails 23 at two ends of the mounting rod 2 can move relatively, when the connecting hole 43 and the flow channel 24 are misplaced, the flow channel 24 is blocked by the blocking block 42, and the positions of the fixing nails 23 at two ends of the mounting rod 2 are kept stable.
The side that rectangular slide block 41 kept away from shutoff piece 42 is fixed to be provided with gag lever post 44, the spacing hole 45 that is the hexagon has all been seted up at adapter sleeve 31 and connecting rod 32 center, be provided with two stopper 46 that correspond adapter sleeve 31 and connecting rod 32 respectively on the gag lever post 44, when stopper 46 and spacing hole 45 block, one of them stopper 46 restriction adapter sleeve 31 rotates, another stopper 46 makes connecting rod 32 keep with gag lever post 44 coaxial state and spacing go-between 33 rotate, when stopper 46 breaks away from with spacing hole 45, adapter sleeve 31 can freely rotate, and connecting rod 32 and go-between 33 can freely move about.
The mounting shaft 21 is slidably provided with a driving pin 47 for driving the rectangular slider 41 to move, the driving pin 47 is tightly attached to the mounting shaft 21, and a sufficient friction force is provided to keep the driving pin 47 in an original state under the action of no external force, when the rectangular slider 41 moves to the limit lever 44 side to the limit position, the connecting hole 43 is communicated with the flow channel 24, the limit block 46 is engaged with the limit hole 45, and when the rectangular slider 41 moves to the limit position to the block 42 side, the connecting hole 43 is dislocated with the flow channel 24, and the limit block 46 is separated from the limit hole 45.
Referring to fig. 1 to 7, the driving pin 47 includes two vertical portions 471 and an inclined portion 472, the two vertical portions 471 are respectively aligned with two ends of the inclined portion 472, a through hole is formed in the rectangular slider 41 in a penetrating manner, the driving pin 47 is arranged in the through hole, a first wedge 411 and a second wedge 412 are respectively mounted on two inner walls of the through hole, the inclined surface of the first wedge 411 faces upwards, the inclined surface of the second wedge 412 faces downwards, planes of the first wedge 411 and the second wedge 412 coincide, the end intervals of the first wedge 411 and the second wedge 412 coincide with the width of the driving pin 47, in an initial state before mounting, the inclined surface of the first wedge 411 is abutted with the left side surface of the inclined portion 472, the end of the second wedge 412 is abutted with the right side surface of the lower vertical portion 471, in this state, when the connecting hole 43 corresponds to the runner 24, the runner 24 is communicated, the fixing nails 23 at two ends of the mounting rod 2 can move relatively, the limiting block 46 is clamped with the limiting hole 45, the movable connecting piece 3 is limited to move, the H-shaped stable state is kept between the mounting rod 2 and the telescopic supporting rod 1, the mounting is convenient, the state vertical to the crack is ensured when the telescopic supporting rod 1 is mounted when the measuring instrument is mounted, the testing accuracy is improved, the comparability of data in a monitoring period is ensured, the deformation condition of the crack is better captured, after the mounting is completed, the driving pin 47 is pressed, the left side surface of the inclined part 472 is pressed against the wedge block 411, the wedge block 411 is transversely moved leftwards, the inclined surface of the wedge block 412 is gradually attached to the right side surface of the inclined part 472 (as shown in figure 5), at the moment, the connecting hole 43 is misplaced with the runner 24, the runner 24 is blocked by the blocking block 42, the positions of the fixing nails 23 at two ends of the mounting rod 2 are kept stable, and the fixing nails 23 keep the state of stably contacting with the inner wall of the crack, the limiting block 46 is separated from the limiting hole 45, the connecting sleeve 31 can rotate freely, the connecting rod 32 and the connecting ring 33 can move freely, a plurality of angle sensors are matched to record the rotation angle between the mounting rod 2 and the telescopic supporting rod 1, and the crack deformation conditions under different conditions can be analyzed.
Referring to fig. 1-7, an adjusting ring 14 is rotationally arranged in an inner cylinder 11, a gasket 15 is slidably arranged in the inner cylinder 11, one side of the gasket 15 is propped against a compression spring 13, the other side of the gasket 15 is fixedly connected with a threaded rod 16, the threaded rod 16 is in threaded connection with the center of the adjusting ring 14, after the measuring instrument is installed, the position of the gasket 15 can be changed by rotating the adjusting ring 14, the measuring range of the measuring instrument can be effectively improved by adjusting the position of the gasket 15, so that cracks with different sizes can be adapted, the measuring instrument is ensured to have enough telescopic space to monitor the deformation of the cracks, a plurality of limiting strips are arranged on the outer peripheral surface of the gasket 15, and a plurality of limiting grooves matched with the limiting strips are formed in the inner wall of the inner cylinder 11.
As shown in fig. 4, in order to detect the accuracy of the data, taking a ground crack as an example, the first rotating shaft 321 is kept at a position perpendicular to the ground during installation, the second rotating shaft 331 is kept at a position parallel to the ground, the axis of the connecting sleeve 31 is taken as the X axis, the axis of the second rotating shaft 331 is taken as the Y axis, the axis of the first rotating shaft 321 is taken as the Z axis, and the concentric point of the connecting sleeve 31, the connecting rod 32 and the connecting ring 33 in a concentric state is taken as an origin, so as to establish a space coordinate system.
The first rotating shaft 321, the second rotating shaft 331 and the connecting sleeve 31 are all provided with angle sensors, and the angle sensors can detect the rotating angles of the first rotating shaft 321, the second rotating shaft 331 and the connecting sleeve 31.
In the prior art, the three-dimensional deformation measuring instrument can only capture equidistant stretching and shearing deformation of the crack, namely the deformation direction actually measured is the vertical movement condition of the crack in the three-axis direction in a standard coordinate system, but the crack deformation condition is various in types, and the three-dimensional deformation measuring instrument also comprises special deformation conditions such as bending deformation and unequal stretching, so that a plurality of groups of measuring instruments are required to be arranged on the same crack, the detection results of different instruments are compared and then analyzed, the data calculation error is increased, and more equipment investment is caused.
Deformation measurements of unidirectional equidistant stretching of the fracture were first analyzed.
Specific: since the crack is only stretched (compressed) equidistantly along the X-axis direction, no reading occurs to all three angle sensors, and the deformation of the crack along the X-axis can be obtained only by calculating the elongation of the telescopic stay bar 1.
According to the following:
F = kx
Wherein F represents the external force applied to the spring, k represents the stiffness coefficient of the spring, and x represents the length of the spring, so that the following can be obtained:
= k/>
Wherein,Represents the amount of change in the external force (the amount of change in the value of the pressure sensor 17) applied to the compression spring 13, and k represents the stiffness coefficient of the compression spring 13,/>The length change amount of the compression spring 13 (the length change of the expansion brace 1) is shown.
It is apparent that the length change of the expansion brace 1 (the length change of the compression spring 13) is the deformation amount of the slit at the time of the tensile deformation.
And secondly analyzing deformation measurement of shear deformation of the crack.
The initial length L1 of the telescopic strut 1 and the initial width L2 of the crack are recorded by a vernier caliper, wherein the ratio of L2 to L1 isThe three-dimensional rotation angle of the movable connecting piece 3 is obtained through an angle sensor, and the change quantity of the X\Y\Z axis is sequentially expressed as followsWhen one end of the telescopic stay bar 1 is set as the origin of coordinates and the other end is set as (x, y, z), the initial position (x 1, y1, z 1) is set, wherein x1 is L1, y1 is 0, z1 is 0, and after the crack is subjected to shear deformation, the crack passes through/>Numerical value of (1) and post-change length of the telescopic strut (1)/>+L1, the end point coordinates (X2, Y2, Z2) after the change can be obtained by combining a trigonometric function, and the three-way displacement quantities of the end part of the telescopic support rod 1 are respectively X-axis direction deformation X2-L1, Y-axis direction deformation Y2 and Z-axis direction deformation Z2, the telescopic support rod 1 is perpendicular to a crack, the crack change quantity is in direct proportion to the change quantity of the telescopic support rod 1, and the three-way displacement quantities of the obtained cracks are respectively X-axis direction deformation/>* (X 2-L1), Y-axis deformation/>* Y2 and Z-axis deformation/>*z2。
Because of the flexibility of the movable connecting piece 3, the testing range of the measuring instrument is wider, and the measuring instrument can adapt to more kinds of crack deformation types, for example, when the lower opening of a crack is enlarged and the upper opening is reduced, the traditional measuring instrument can only detect simple transverse deformation, and in the measuring instrument of the invention, the condition that the readings of the angle sensors at two corresponding positions are opposite is shown, namely, the rotation directions of the two second rotating shafts 331 are opposite.
When the outer opening of the crack is enlarged and the inner opening is reduced, the traditional measuring instrument can only detect simple transverse deformation, and the condition that the readings of the two angle sensors at corresponding positions are opposite is shown in the measuring instrument of the invention, namely, the rotation directions of the two first rotating shafts 321 are opposite.
In the case of the fracture rotation shear deformation, the conventional measuring instrument may be directly damaged due to the installation problem, and in the measuring instrument of the present invention, it is shown that two angle sensors located on the connecting sleeves 31 have opposite readings, that is, the two connecting sleeves 31 are rotated in opposite directions.
The application method of the crack three-way deformation measuring instrument comprises the following steps:
S1: the instrument is installed, the movable connecting piece 3 is movably limited through the limiting mechanism 4, so that the two groups of mounting rods 2 and the telescopic supporting rod 1 form a stable H-shaped structure, the telescopic supporting rod 1 is compressed, the whole measuring instrument is placed into a crack, the telescopic supporting rod 1 is kept perpendicular to the crack, the telescopic supporting rod 1 is loosened after the measuring instrument is placed in the crack, the compression spring 13 is stretched, the fixing nails 23 at the end parts of the two groups of mounting rods 2 are propped against the inner wall of the crack, the fixing nails 23 slide in the sleeve 22 when propped against the inner wall of the crack so as to adapt to the inner wall of the crack, until after each fixing nail 23 is stably contacted with the inner wall of the crack, the limiting mechanism 4 is controlled to release the limitation of the movable connecting piece 3, meanwhile, the runner 24 is blocked, and the fixing nails 23 are kept stable;
by rotating the adjusting ring 14, the pad 15 is controlled to move, and the reading of the pressure sensor 17 in this state is preset to an initial value.
S2: after the tester is installed, the deformation condition of the crack is analyzed by monitoring the numerical changes of the pressure sensor 17 and each angle sensor through the remote equipment;
S3: numerical calculation, namely, according to the absolute value of the numerical variation of the pressure sensor 17, the length variation of the telescopic stay bar 1 is obtained by combining the stiffness coefficient of the compression spring 13, the angular variation of the telescopic stay bar 1 in all directions can be obtained by the numerical variation of the angle sensor, and the components of the telescopic amount of the telescopic stay bar 1 in all directions are obtained by combining the components, namely, the deformation amounts of corresponding cracks in all directions.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.