Multipurpose circular foundation embedded bolt positioner

Abstract

The utility model discloses a multipurpose round foundation embedded bolt positioner which comprises a positioning shaft, a positioning module, a positioning disc, a prism and a fixing support. The positioning shaft consists of a shaft body and a graduated scale on the shaft body and is horizontally arranged; the prism is arranged above the end side of the shaft body, and the central point of the prism corresponds to the zero graduation line of the graduated scale; the positioning module comprises a positioning plate which is vertically arranged, the top side of the positioning plate is detachably fixed to the shaft body through a fixing block, and the bottom end of the plate body is provided with a tip which is located on the same vertical plane with the central axis of the shaft body. The positioning disc is a horizontally-arranged circular disc body, and angle scale marks are arranged on the positioning disc. The fixed support comprises a base, a length-adjustable supporting column is arranged on the base, a positioning disc, a positioning shaft and a mounting frame are arranged at the top end of the supporting column from bottom to top, the positioning shaft is rotationally arranged, and the positioning disc and the prism are fixedly arranged; the positioner can be used for positioning construction and construction acceptance of various circular foundation embedded bolts, the working efficiency is improved, the construction period is shortened, the rework rate is reduced, and the labor cost is saved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of round foundation construction process control in construction engineering, especially relates to a multipurpose round foundation embedded bolt positioner. BACKGROUND

[0002] In recent years, with the continuous development of construction engineering, various types of engineering projects are increasing. In the construction process, higher requirements are put forward for the construction and installation of round foundation embedded bolts from the aspects of technology, safety and efficiency. According to the experience of previous round foundation embedded bolt construction and installation, the traditional construction method is to use a total station instrument to cooperate with a manual tape measure to measure the plane position, and use a level to measure the elevation position. The control of the plane position and the relative position of the embedded bolt is poor, the embedded bolt rework rate is high, the accuracy of the installation of the upper component in the later stage is not ideal, and the engineering progress and quality are affected. The position of the embedded bolt is determined by the reverse ruler, which has poor effect in actual work, high rework rate and large installation error of the embedded bolt, which greatly affects the installation of the subsequent upper component and delays the overall progress of the construction period. In the current improved construction scheme, although the construction error can be reduced by multiple measurements, the consistency of the construction results is consumed under the premise of a large amount of manpower, and the cost of manpower and material resources is too high. Therefore, in order to improve the construction efficiency and ensure the smooth progress of the construction work, it is necessary to design a multipurpose round foundation embedded bolt positioner. CONTENT OF THE UTILITY MODEL

[0003] The utility model aims at providing a multipurpose round foundation embedded bolt positioner which solves the above technical problems.

[0004] Therefore, the utility model technical scheme is as follows:

[0005] A multipurpose round foundation embedded bolt positioner, comprising a positioning shaft, a positioning module, a positioning disc, a prism and a fixed support, wherein the positioning shaft is horizontally arranged and is composed of a shaft body and a scale; the scale is fixed on the front side wall of the shaft body along the length direction of the shaft body; the prism is arranged above the end side of the shaft body through a mounting frame, and the center point of the prism corresponds to the zero scale line of the scale; the positioning module comprises a vertically arranged positioning plate, the top side of the positioning plate is detachably fixed on the shaft body through a fixed block, the bottom end of the positioning plate is provided with a sharp end, and the end point of the sharp end is located on the same vertical plane as the central axis of the shaft body; the positioning disc is a horizontally arranged circular disc body, and a circle of angle scale lines is uniformly arranged on the top surface edge of the circular disc body in the circumferential direction; the fixed support is composed of a base and a support column which is vertically fixed at the center of the base; the support column is a length-adjustable column body, the positioning shaft, the positioning disc and the mounting frame are arranged from bottom to top at the top end of the support column, the positioning shaft is arranged in a freely rotating manner, and the positioning disc and the prism are fixedly connected with the support column in a coaxial arrangement manner with the support column.

[0006] Further, the shaft body is a cuboid strip, and a guide through slot is centrally formed on the front side wall surface of the shaft body along the length direction; the slot opening width of the guide through slot is smaller than the inner side width of the through slot, so that strip limiting steps are formed on both sides of the slot opening of the guide through slot.

[0007] Further, a mark line is centrally formed on the top surface of the shaft body along the length direction.

[0008] Further, the shaft body is a cuboid strip made of light aluminum alloy, and the length is 0.5m-1.5m.

[0009] Further, a horizontal bubble is horizontally arranged on the top side of the prism and the positioning shaft, so as to ensure that the positioning shaft and the prism are arranged in a horizontal state.

[0010] Further, the fixing block comprises a connecting column, a fixing bolt is radially arranged in the middle of the connecting column and is threadedly connected, the tail end of the fixing bolt is sleeved with and threadedly connected with an embedded block, the size of the embedded block is adapted to the size of the guide through slot, a connecting shaft is vertically fixed on the end face of one end of the connecting column, a positioning plate is sleeved on the connecting shaft on the top side, and the positioning plate is fixed by a second limiting sleeve and a first limiting sleeve which are sleeved and fixed on the connecting shaft.

[0011] Further, a rotating handle is fixed on the nut of the fixing bolt.

[0012] Further, an extension plate is horizontally extended on one side of the positioning plate, and the top surface of the extension plate abuts against the bottom surface of the shaft body, so that the positioning plate is arranged in a vertical state.

[0013] Further, the base comprises a bottom plate arranged horizontally, and a positioning pad is arranged at each top corner of the bottom surface of the bottom plate, and a plurality of high-strength bolts are respectively arranged through the bottom plate and the positioning pad at each top corner of the base, so as to fix the base on the designated ground.

[0014] Further, the supporting column is composed of an outer sleeve and an inner column body, and the inner column body is arranged through and threadedly connected in the outer sleeve; a second connecting column is vertically fixed in the middle of the top surface of the inner column body, so that the positioning disc, the positioning shaft and the mounting frame are arranged from bottom to top on the second connecting column through the mounting hole centrally formed.

[0015] Compared with the prior art, the multipurpose circular foundation pre-buried bolt positioner can be widely applied in the positioning construction and construction acceptance of various circular foundation pre-buried bolts, and the pre-buried position of the bolt can be quickly calibrated by using the positioner in the positioning construction process; whether the pre-buried bolt position and elevation meet the engineering design requirements can be quickly determined by using the positioner in the construction acceptance process; compared with the existing construction scheme, the application of the positioner can greatly improve the overall work efficiency, so as to reduce the process, save the construction period, reduce the rework rate and save the labor cost. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the structure schematic view of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0017] Figure 2 It is the front view structure schematic view of the positioning shaft of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0018] Figure 3 It is the side view structure schematic view of the positioning shaft of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0019] Figure 4 It is the structure schematic view of the positioning disc of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0020] Figure 5 It is the structure schematic view of the support column of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0021] Figure 6 It is the structure schematic view of the base of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0022] Figure 7 It is the structure schematic view of the positioning plate of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0023] Figure 8 It is the front view structure schematic view of the positioning block of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0024] Figure 9 It is the side view structure schematic view of the positioning block of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model.

[0025] Figure 10 It is the use state schematic view of the multipurpose circular foundation pre-buried bolt positioner in the embodiment of the utility model. DETAILED DESCRIPTION

[0026] The utility model will be further explained in connection with the drawings and specific embodiments, but the following embodiments are by no means any limitation on the utility model.

[0027] Referring to Figure 1 The multipurpose circular foundation pre-buried bolt positioner includes the positioning shaft 1, the positioning module, the positioning disc 6 and the prism 7 arranged on the fixed support.

[0028] Referring to Figure 2 And Figure 3The positioning shaft 1 is composed of a shaft body 101 and a scale 102; wherein the shaft body 101 is a cuboid strip body, a guide through slot 1011 is centrally formed on the front side wall surface of the shaft body 101 along the length direction, and the slot width of the guide through slot 1011 is smaller than the inner width of the through slot, so that strip limiting steps are formed on both sides of the slot of the guide through slot 1011; the scale 102 is fixed on the front side wall surface of the shaft body 101 along the length direction of the shaft body 101 and is located on the upper side of the guide through slot 1011, so that in actual application, the scale 102 is used to accurately position the position of the positioning module on the shaft body 101; a mark line 103 is centrally arranged on the top surface of the shaft body 101 along the length direction of the shaft body 101, and corresponds to the central axis of the shaft body 101, so as to be used in cooperation with the positioning disc 6;

[0029] In the embodiment, in order to improve the convenience of construction, the length of the shaft body 101 is 1 m, and the shaft body 101 is made of light aluminum alloy, so that the shaft body 101 can meet the positioning and pre-burying of the bottom pre-burying bolts of the cylindrical structure body with different diameters, and the shaft body 101 can be kept in a horizontal arrangement state at the same time. Figure 1 Based on the direction shown in the figure, the measurement range of the scale 102 is 0 cm~100 cm, the 0 scale line of the scale 102 is located on the left side of the shaft body 101, and the 100 cm scale line of the scale 102 is located on the right side of the shaft body 101; the accuracy of the scale is 1 mm.

[0030] Referring to Figure 1 The prism 7 is a prism matched with the total station, and is fixed on the upper side of the left end of the shaft body 101 through a mounting frame, and the center point of the prism 7 corresponds to the 0 scale line of the scale 102, specifically, the 0 scale line of the scale 102 and the center point of the prism 7 are located on the same vertical plane in the radial direction of the shaft body, so that whether the setting position of the prism 7 is located at the center point of the installation position of the circular foundation structure is determined by cooperating the prism 7 with the total station arranged at the construction site, and then the prism 7 is arranged at the center of the rotating track corresponding to the rotating part of the positioner, so as to accurately position the position of the pre-burying bolt matched with the circular foundation structure by the positioner.

[0031] As a preferred technical solution of the embodiment, a horizontal bubble is arranged on each of the top side of the positioning shaft 1 and the prism 7, so as to ensure that the positioning shaft 1 and the prism 7 are arranged in a horizontal state.

[0032] Referring to Figure 1 The positioning module is composed of a fixed block 2 and a positioning plate 3; wherein,

[0033] Referring to Figure 8 and Figure 9, the fixed block 2 includes a connecting column 201, a connecting shaft 202, a first limiting sleeve 203, a second limiting sleeve 204, an embedded block 205, a fixed bolt 206 and a rotating handle 207; specifically, the connecting shaft 202 is vertically fixed on the end face of one end of the connecting column 201, and the second limiting sleeve 204 and the first limiting sleeve 203 are sequentially sleeved and fixed on the connecting shaft 202; a threaded hole is radially formed in the middle of the connecting column 201, so that the fixed bolt 206 is vertically threaded in the threaded hole and is screwed on the connecting column 201; the embedded block 205 is a block body with a size suitable for the size of the guide groove 1011, which is threaded on the tail end of the fixed bolt 206 through the centrally formed threaded hole and abuts against the side wall of the connecting column 201; the rotating handle 207 is an L-shaped handle body, one end of which is fixed on the nut of the fixed bolt 206, so as to rotate the fixed bolt 206.

[0034] Referring to Figure 7 , the positioning plate 3 includes a strip-shaped plate body 301; wherein, one end of the top side of the plate body 301 extends upward to form a connecting lug plate 302, a through hole with a diameter suitable for the connecting shaft 202 is formed on the connecting lug plate 302, so that in actual application, the positioning plate 3 is sleeved on the connecting shaft 202 through the through hole on the connecting lug plate 302 and is located between the first limiting sleeve 203 and the second limiting sleeve 204, so as to be press-fitted and fixed by the first limiting sleeve 203 and the second limiting sleeve 204; the other end of the top side of the plate body 301 extends to form an extension plate in the horizontal direction, and the longitudinal length of the connecting lug plate 302 is suitable for the distance from the bottom side of the shaft body 101 to the guide groove 1011 thereon, so that the top surface of the extension plate of the positioning plate 3 can abut against the bottom surface of the shaft body 101; the bottom end of the plate body 301 is provided as a sharp end, and the sharp end point is located on the same vertical plane as the mark line 103 drawn on the shaft body 101, that is, is coplanar with the central axis of the shaft body 101, so that in actual application, the sharp end point is used as a positioning end to realize accurate positioning of the bolt embedded position.

[0035] In actual application, the fixed block 2 is slidably embedded into the guide groove 1011 from the end side of the guide groove 1011 through the embedded block 205, and since the slot width of the guide groove 1011 is smaller than the inner width thereof, the embedded block 205 will not be detached from the slot of the guide groove 1011; the rotating handle 207 is rotated to drive the fixed bolt 206 to rotate synchronously, and the length of the tail end of the fixed bolt 206 extending to the outside of the embedded block 205 increases under the thread cooperation between the fixed bolt 206 and the connecting column 201, until it abuts against the groove bottom of the guide groove 1011; the embedded block 205 moves relatively to the slot opening in the guide groove 1011 and abuts against the limiting step of the slot opening of the guide groove 1011, at this time, the fixed block 2 is relatively fixed on the positioning shaft 1, and the top surface of the extension plate of the positioning plate 3 abuts against the bottom surface of the positioning shaft 1.

[0036] Referring to Figure 4The positioning disc 6 is a circular disc body with a through hole in the center, which is horizontally arranged between the positioning shaft 1 and the prism 7, and the central axis of the circular disc body is coincided with the extension line of the zero scale line of the scale 102 on the positioning shaft 1; a circle of angle scale lines is uniformly arranged on the top surface edge of the positioning disc 6 in the circumferential direction, so as to realize the angle range of 0°~360° and the angle positioning accuracy of 1°.

[0037] Referring to Figure 5 and Figure 6 The fixed support is composed of the base 4 and the supporting column 5; wherein,

[0038] The base 4 includes a horizontally arranged triangular bottom plate 401, a screw hole 403 is arranged in the center of the triangular bottom plate 401, and a circular positioning pad 402 is arranged at each of the three top corners of the bottom surface of the triangular bottom plate 401; three high-strength bolts are respectively arranged on the bottom plate 401 and the positioning pad 402 at the three top corners of the base 4, so that the multipurpose circular foundation pre-buried bolt positioner is fixed at the designated position of the construction site through the base 4;

[0039] The supporting column 5 is a length-adjustable column body, the bottom end of which is fixed vertically in the center of the base 4, and the top end of which is connected with the positioning shaft 1, the positioning disc 6 and the prism 7 from bottom to top; in this embodiment, the supporting column 5 is composed of an outer sleeve 501 and an inner column body, and the inner column body is threadedly connected in the outer sleeve 501, so that in actual application, the length adjustment of the inner column body relative to the outer sleeve 501, that is, the length adjustment of the supporting column 5, is realized by rotating the inner column body; a second connecting column 502 is fixed in the center of the top of the inner column body, and a vertical through hole is correspondingly arranged in the left end of the shaft body 101, so that the shaft body 101 and the positioning disc 6 are sequentially sleeved on the second connecting column 502; the second connecting column 502 is provided with external threads at the top end, so that it can be threadedly connected in the through hole arranged in the center of the bottom of the mounting frame of the prism, realizing the relative positioning of the prism and the positioning shaft, and also avoiding the shaft body 101 and the positioning disc 6 sleeved on the second connecting column 502 from being separated from the second connecting column 502; wherein, the positioning disc 6 is horizontally fixed on the bottom surface of the mounting frame, so as to avoid moving with the rotation of the positioning shaft; the bottom end of the outer sleeve 501 is provided with a connecting external thread, which is threadedly connected in the central screw hole 403 of the triangular bottom plate 401, realizing the connection and fixation of the supporting column 5 and the base 4.

[0040] Referring to Figure 10 Taking the mooring column pre-buried part and the pre-buried bolt operation process of this embodiment as an example, the specific operation steps of the positioning construction and construction acceptance process completed by using the multipurpose circular foundation pre-buried bolt positioner are described in detail as follows.

[0041] Step one, installing the multipurpose circular foundation pre-buried bolt positioner at the fixed position of the mooring column:

[0042] At the wharf side, according to the actual engineering construction, the specific installation position of the mooring dolphin is determined, and the outer contour line 8 of the mooring dolphin is drawn on the ground; the multipurpose circular foundation pre-buried bolt positioner is fixed at the center of the outer contour line 8, and after accurate positioning through the prism 7, the base 4 of the positioner is fixed on the ground, and the leveling is performed through the horizontal bubble provided on the prism 7 and the positioning shaft 1.

[0043] Step two, positioning construction:

[0044] In this project, two groups of pre-buried bolts are designed on the bottom surface of the mooring dolphin, each group of pre-buried bolts is composed of eight pre-buried bolts arranged along the circumferential direction, and each group of pre-buried bolts is arranged in one-to-one correspondence; based on this, eight times of positioning along the circumferential direction are required in the construction process, and after each positioning, the specific pre-buried position is determined according to the distance between the two bolts 8 in the radial direction relative to the center position;

[0045] Specifically, first, the length of the support column 5 is adjusted so that the bottom end tip of the positioning plate 3 approaches the ground position, so as to facilitate marking after subsequent positioning; then, the positioning shaft 1 is rotated to the 0° scale line of the positioning disc 6, specifically, the 0° scale line is overlapped with the mark line 103 on the shaft body 101; then, the fixed position of the fixed block 2 on the shaft body 101 is adjusted according to the scale 102, so as to determine whether the position of the positioning plate 3 is consistent with the distance between the first bolt 8 and the center position according to the overlapping position of the scale line on the scale 102 and the positioning plate 3, at this time, the bottom end tip of the positioning plate 3 points to the pre-buried design position center of the bolt 8, and the position is marked; then, the fixed position of the fixed block 2 on the shaft body 101 is adjusted to the pre-buried design position of the second bolt 8 in the same direction, and the position is marked;

[0046] Next, the positioning shaft 1 is rotated by 45°, so that the 45° scale line of the positioning disc 6 is overlapped with the mark line 103 on the shaft body 101; in the same way as described above, the pre-buried design positions of the two bolts 8 are positioned and calibrated by adjusting the position of the fixed block 2 on the shaft body 101;

[0047] The above steps are repeated until the pre-buried design positions of the eight bolts 8 in the two groups of pre-buried bolts are calibrated; the positioner is removed and moved away.

[0048] Step three, pre-buried bolt construction:

[0049] According to the pre-buried design position calibration results of the eight bolts 8 in the two groups of pre-buried bolts in step two, the installation position of the mooring dolphin is pre-buried with bolts.

[0050] Step four, pre-buried bolt construction acceptance:

[0051] Firstly, the positioner is fixed again at the center of the outer contour line 8, and is leveled by the horizontal bubble provided on the prism 7 and the positioning shaft 1; then, according to the length of the embedded bolt 8 exposed above the ground, the length of the supporting column 5 is adjusted so that the bottom end tip of the positioning plate 3 is flush with the top surface of the embedded bolt 8; then, the fixed position of the fixed block 2 on the shaft body 101 is adjusted according to the scale 102, so that the positioning plate 3 is coincident with the scale line on the scale 102, and the distance between the embedded bolt 8 of the inner group and the center position is consistent; the shaft body 101 is rotated at an angle interval of 45° for one turn, and whether the bottom end tip of the positioning plate 3 abuts against the top surface of the embedded bolt 8 and whether it is located at the center of the top surface of the embedded bolt 8 at the specified angle position are observed, so as to determine whether the embedded position of the embedded bolt 8 is consistent with the actual engineering; the embedded bolt 8 of the outer group is detected in the same way as the above method.

[0052] The multipurpose circular foundation embedded bolt positioner can be used in the positioning construction and construction acceptance of the embedded bolt respectively; in the positioning construction process, the positioner can be used to quickly calibrate the embedded position of the bolt; in the construction acceptance process, the positioner can be used to quickly determine whether the embedded bolt position and elevation meet the engineering design requirements; compared with the existing construction scheme, the application of the positioner can greatly improve the overall work efficiency, reduce the process, save the construction period, reduce the rework rate, and save the labor cost; in actual construction operation, the expected overall plane position can be controlled within ±2mm, the relative plane position can be controlled within ±1mm, the embedded bolt one-time acceptance pass rate is more than 95%, the unqualified acceptance and rework conditions are basically eliminated, the labor cost and material cost are reduced, the engineering construction efficiency is improved, and the engineering quality and progress are ensured.

[0053] The above is only a preferred embodiment of the present application, and does not limit the structure of the present application in any form. Any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application still belongs to the technical solution range of the present application.

Claims

1. A multi-purpose circular foundation pre-embedded bolt locator, characterized in that, The system includes a positioning shaft (1), a positioning module, a positioning disk (6), a prism (7), and a fixed support. The positioning shaft (1) is horizontally positioned and consists of a shaft body (101) and a scale (102). The scale (102) is fixed to the front wall of the shaft body (101) along its length. The prism (7) is mounted above the end of the shaft body (101) via a mounting bracket, and its center point corresponds to the zero mark of the scale (102). The positioning module includes a vertically positioned positioning plate (3), whose top side is detachably fixed to the shaft body (101) via a fixing block (2), and whose bottom end has a pointed tip with the tip end aligned with the shaft body (101). The central axis of the shaft (101) is located on the same vertical plane; the positioning plate (6) is a horizontally set circular plate with a ring of angle scale lines evenly distributed along the circumference at the edge of its top surface; the fixed support is composed of a base (4) and a support column (5) vertically fixed at the center of the base (4); the support column (5) is a column with adjustable length, and the positioning shaft (1), positioning plate (6) and mounting bracket are set at the top of the support column (5) from bottom to top. The positioning shaft (1) is set to rotate freely, and the positioning plate (6) and prism (7) are fixedly connected to the support column (5) in a way that is coaxial with the support column (5).

2. The multi-purpose circular foundation embedded bolt locator according to claim 1, characterized in that, The shaft (101) is a cubic strip with a guide groove (1011) centered along the length direction on its front side wall. The width of the guide groove (1011) is smaller than the inner width of the groove, so that strip-shaped limiting steps are formed on both sides of the guide groove (1011).

3. The multi-purpose circular foundation embedded bolt locator according to claim 1, characterized in that, A marking line (103) is provided in the center along the length direction on the top surface of the shaft (101).

4. The multi-purpose circular foundation embedded bolt locator according to claim 1, characterized in that, The shaft (101) is a cubic strip made of lightweight aluminum alloy with a length of 0.5m to 1.5m.

5. The multi-purpose circular foundation embedded bolt locator according to claim 1, characterized in that, A level bubble is horizontally set on the top side of the positioning shaft (1) and the prism (7) to ensure that the positioning shaft (1) and the prism (7) are set in a horizontal state.

6. The multi-purpose circular foundation embedded bolt locator according to claim 2, characterized in that, The fixing block (2) includes a connecting column (201), in which a fixing bolt (206) is threaded through and connected radially in the middle; an insert block (205) is fitted and threaded at the tail end of the fixing bolt (206), and the size of the insert block (205) is adapted to the size of the guide groove (1011); a connecting shaft (202) is vertically fixed on one end face of the connecting column (201), and the top side of the positioning plate (3) is fitted on the connecting shaft (202), and is limited and fixed by the second limiting sleeve (204) and the first limiting sleeve (203) fitted and fixed on the connecting shaft (202).

7. The multi-purpose circular foundation embedded bolt locator according to claim 6, characterized in that, A rotating handle (207) is fixed to the nut of the fixing bolt (206).

8. The multi-purpose circular foundation embedded bolt locator according to claim 1, characterized in that, The positioning plate (3) extends horizontally on one side and forms an extension plate. The top surface of the extension plate abuts against the bottom surface of the shaft (101), so that the positioning plate (3) is kept in a vertical position.

9. The multi-purpose circular foundation embedded bolt locator according to claim 1, characterized in that, The base (4) includes a horizontally set base plate, and positioning pads are set at each of the top corners of its bottom surface. Multiple high-strength bolts are respectively inserted into the base plate and positioning pads at each of the top corners of the base (4) to fix the base (4) on the designated ground.

10. The multi-purpose circular foundation embedded bolt locator according to claim 1, characterized in that, The support column (5) is composed of an outer sleeve (501) and an inner column, and the inner column is threaded through and connected to the outer sleeve (501); a second connecting column (502) is vertically fixed in the center on the top surface of the inner column, so that the positioning plate (6), the positioning shaft (1) and the mounting bracket are set on the second connecting column (502) from bottom to top through the mounting hole opened in the center.

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