Multi-degree-of-freedom steel structure unloading device

Abstract

The utility model discloses a multi-degree-of-freedom steel structure unloading device, and belongs to the technical field of steel structure unloading. The device comprises a bearing supporting table structure and a bearing base plate, the bearing base plate is arranged in the bearing supporting table structure in a sleeved mode, a rotating mechanism is installed at the bottom of the bearing supporting table structure, an XY-axis sliding platform is installed at the bottom of the rotating mechanism, and the interior of the bearing supporting table structure and the outer contour of the bearing base plate are both circular arcs. Under the assistance of the X-axis and Y-axis sliding platform and the rotating mechanism, the load-bearing supporting table structure is subjected to X-axis sliding, Y-axis sliding and horizontal rotating operation, and the arc on the load-bearing base plate is subjected to radial rotation along the arc on the load-bearing supporting table structure; therefore, the horizontal displacement and the horizontal and vertical angular displacement which are generated along with the unloading of the steel structure are released to ensure the smooth unloading and falling of the steel structure. According to the utility model, horizontal displacement and corner displacement which are generated along with unloading of the steel structure can be effectively released, so that smooth unloading and falling of the steel structure are ensured.

Description

Technical Field

[0001] The utility model relates to a multi-freedom steel structure unloading device, belonging to the technical field of steel structure unloading. Background Art

[0002] Steel structure unloading supports are important devices for steel structure construction and installation. They can support and fix various parts of the steel structure during the construction process to ensure that the structure can firmly bear its own weight and various forces during the construction process to ensure the smooth unloading and placement of the steel structure. These supports are usually used in the main arch of large-span steel structures to maintain the stability of the structure during installation and adjustment.

[0003] In general construction, temporary supports are often used that are welded from steel plates. Steel plates (such as Figure 1 As shown in the figure, the positions of the steel plates and supports are fixed by the steel columns on both sides. When the steel structure is unloaded, the workers mainly extract the steel plates under the supports to realize the positioning of the supports and complete the unloading of the steel structure. However, manual operation is difficult and has low safety. When the large-span steel structure is unloaded, uneven settlement is likely to occur at different positions of the steel structure, causing construction errors, which is easy to cause the steel structure to be constrained by the temporary supports (such as Figure 1 As shown, there are steel columns on both sides of the temporary support to constrain the steel plate and the support, which makes the device unable to release the horizontal displacement (△X) and vertical angular displacement (△θ) generated when the steel structure is unloaded. In addition, the steel structure (solid line) represents the initial position of the steel structure, the steel structure (dashed line) represents the position of the steel structure after deflection, and the unloading direction is from top to bottom) and cannot be smoothly placed in place; therefore, there is an urgent need for a multi-degree-of-freedom steel structure unloading support that is convenient for workers to operate and can release constraints. Utility Model Content

[0004] The utility model provides a multi-freedom steel structure unloading device, which solves the problems of difficult operation and low safety caused by manual extraction of steel plates, uneven settlement when unloading large-span steel structures, and failure to smoothly land due to temporary supports constraining the steel structure.

[0005] The technical problem to be solved by the utility model is achieved by adopting the following technical solutions:

[0006] A multi-degree-of-freedom steel structure unloading device comprises a load-bearing support structure and a load-bearing pad, wherein the load-bearing pad is sleeved in the load-bearing support structure, a rotating mechanism is installed at the bottom of the load-bearing support structure, an XY-axis sliding platform is installed at the bottom of the rotating mechanism, the interior of the load-bearing support structure and the exterior contour of the load-bearing pad are both set as circular arcs, which are used for, when the steel structure is unloaded, with the assistance of the XY-axis sliding platform and the rotating mechanism, to make the load-bearing support structure perform X-axis sliding, Y-axis sliding and horizontal rotation operations to release the horizontal displacement and horizontal angular displacement generated when the steel structure is unloaded, and the circular arc on the load-bearing pad is radially rotated along the circular arc on the load-bearing support structure to release the vertical angular displacement, thereby ensuring the smooth unloading and placement of the steel structure.

[0007] It should be noted that before unloading the steel structure, the following operations need to be performed:

[0008] The inner side of the load-bearing pad is grooved to fit the shape of the upper steel structure. The steel structure is hoisted and fixed in the groove of the load-bearing pad. After the overall welding and installation of the steel structure is completed, the steel structure is unloaded.

[0009] As a preferred example, flanges are respectively provided on the outer walls of both end portions of the load-bearing pad, and the flanges radially rotate along the arc within the load-bearing support structure, and are also convenient for installation on the load-bearing support structure.

[0010] As a preferred example, the difference between the depth of the load-bearing support structure and the depth of the load-bearing pad is 5-15 cm, and there is a gap between the flanges on each side of the load-bearing pad and the outer side of the arc on the load-bearing support structure.

[0011] As a preferred example, the rotating mechanism includes a rotating base structure, the bottom of the load-bearing support structure is rotatably sleeved on the rotating base structure, and the bottom of the rotating base structure is slidably mounted on an XY-axis sliding platform.

[0012] Furthermore, the rotating base structure includes a rotating base plate, a rolling groove, a rotating base boss, and a ball bearing, wherein the bottom of the rotating base plate is mounted on the XY axis sliding platform, the rolling groove is opened on the rotating base plate, the bottom of the rotating base boss extends into the rolling groove and is fixed to the rotating base plate, and the ball bearing is mounted in the rolling groove;

[0013] The load-bearing support platform structure includes a load-bearing support platform column and a load-bearing support platform. The load-bearing support platform column is installed on the outer bottom of the load-bearing support platform. The arc on the load-bearing support platform structure is arranged on the weighing support platform. A channel is opened on the load-bearing support platform column. The load-bearing support platform column is sleeved on the rotating base boss through the channel, and the bottom surface of the load-bearing support platform column contacts with the ball in the rolling groove, so that the load-bearing support platform rotates on the rotating base, and the load-bearing pad rotates to release the radial displacement relative to the load-bearing support platform structure caused by unloading of the steel structure.

[0014] As a preferred example, the XY-axis sliding platform includes a Y-direction sliding base plate and an X-direction sliding base plate, and the Y-direction sliding base plate and the X-direction sliding base plate are both provided with sliding tracks, the sliding track on the Y-direction sliding base plate is arranged along the Y-axis on the Y-direction sliding base plate, the sliding track on the X-direction sliding base plate is arranged along the X-axis on the X-direction sliding base plate, and the two ends of the rotating base plate are respectively slidably arranged in the sliding track on the Y-direction sliding base plate, a moving plate is installed at the bottom of the Y-direction sliding base plate, and the two ends of the moving plate are respectively slidably arranged on the sliding track on the X-direction sliding base plate, a limiting structure for limiting the sliding of the rotating base plate is provided on the Y-direction sliding base plate, and a limiting structure for limiting the sliding of the moving plate is also provided on the X-direction sliding base plate.

[0015] Furthermore, the Y-direction sliding bottom plate is provided with a first roller for assisting the rotating bottom plate to slide on the Y-direction sliding bottom plate, and the X-direction sliding bottom plate is provided with a second roller for assisting the moving plate to slide on the X-direction sliding bottom plate.

[0016] As a preferred example, the limiting structure is a limiting bolt, and a plurality of bolt holes are provided at both ends of the two opposite side walls of the Y-direction sliding base plate or at both ends of the two opposite side walls of the X-direction sliding base plate. The limiting bolts are screwed into the bolt holes, and the roots of the limiting bolts limit the movement of the rotating base plate or the movable plate.

[0017] Furthermore, when the limit bolt is installed in the bolt hole, there is a gap between the movable plate or the rotating base plate, which is used to allow the support to release the steel structure to unload, resulting in horizontal displacement in the X direction and horizontal displacement in the Y direction.

[0018] As a preferred example, a steel rib is installed at the bottom of the X-axis sliding base plate through locking bolts, and jacks are installed at the four corners and the middle of the bottom of the steel rib respectively. A load-bearing steel plate is also arranged at the bottom of the steel rib to bear the total pressure of the steel rib and the components on the steel rib after the jack is lifted or lowered.

[0019] As a preferred example, the steel rib is a channel steel, a cross-shaped reinforcement rib is placed in the groove of the channel steel, and the telescopic end of the jack passes through the channel steel and is fixed to the cross-shaped reinforcement rib by bolts.

[0020] The beneficial effects of the utility model are:

[0021] 1. The utility model greatly improves the anti-overturning capacity of the temporary support, and can effectively release the horizontal displacement and angular displacement generated when the steel structure is unloaded, so as to ensure the smooth unloading and placement of the steel structure; wherein, the horizontal displacement includes the X-axis horizontal displacement and the Y-axis horizontal displacement, and the angular displacement includes the horizontal angular displacement and the vertical angular displacement, that is, the horizontal angular displacement is the rotation of the bearing support column on the rotating base structure, which is assisted by the ball on the rotating base structure and is restricted by the rotating base boss, so as to realize the rotation of the bearing support structure, and finally the bearing pad is rotated to form the displacement; the vertical angular displacement is realized by the bearing pad, and the bearing pad can release a certain vertical angular displacement along the arc surface under the premise of ensuring the safety of the steel structure;

[0022] 2. When the jack is lifted, the end of the jack is stuck in the groove under the steel rib. When the steel structure is unstable, multiple jacks are lifted simultaneously to perform more effective and safer support and remedial work. When the jack is stuck in the groove on the steel rib, it abuts against the cross-shaped reinforcement ribs in the groove to improve the safety and stability of the device during lifting work;

[0023] 3. The assembled design makes installation and operation easy, which is conducive to high-altitude lifting operations during construction. While solving the problem of unloading the steel structure, it improves the convenience of construction operations and is suitable for promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a steel plate in the prior art;

[0025] Figure 2 It is a schematic diagram of the structure of the utility model;

[0026] Figure 3 for Figure 2 Schematic diagram of the structure of part A;

[0027] Figure 4 for Figure 2 The structural diagram of part B;

[0028] Figure 5 It is an exploded view between the load-bearing support platform structure and the load-bearing pad in the present invention, wherein the direction of the arrow indicates the moving direction of the load-bearing pad relative to the load-bearing support platform structure;

[0029] Figure 6 It is an exploded view between the load-bearing support structure and the rotating base structure in the utility model;

[0030] Figure 7 It is an exploded view of the cross-shaped reinforcement rib, jack, and locking bolt in the utility model;

[0031] Figure 8It is a structural schematic diagram of the load-bearing pad in the utility model when it is tilted on the load-bearing support platform structure.

[0032] In the figure: steel rib plate 1; sliding track 2; Y-axis sliding base plate 3; rotating base structure 4; rotating base 41; rotating base boss 42; rolling groove 43; ball 44; load-bearing support platform structure 5; load-bearing support platform column 51; load-bearing support platform 52; load-bearing pad 6; jack 7; load-bearing steel plate 8; moving plate 9; limiting bolt 10; convex rafter 11; cross-shaped reinforcement rib 12; locking bolt 13; X-axis sliding base plate 14; first roller 15; second roller 16. DETAILED DESCRIPTION

[0033] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below in conjunction with specific illustrations.

[0034] Before hoisting and welding the steel structure, place the following device above the pedestal at the designated support position, hoist the steel structure onto the structure for welding, and after hoisting and welding the steel structure, unload the steel structure. Use a jack to lift the device, extract a certain number of load-bearing steel plates from below, and then lower the height of the jack to allow the load-bearing steel plates below to bear the load to meet long-term stress requirements. The horizontal sliding and horizontal and vertical rotation of the steel structure can be released through the device, thereby ensuring that the steel structure is not constrained and can be unloaded and placed smoothly. While ensuring the stability of the steel structure, the height of the load-bearing steel plates is gradually reduced, and finally the device is completely removed to complete the unloading of the steel structure.

[0035] When the steel structure becomes unstable during unloading, the jack is used to provide sufficient support to the unstable structure. After the jack is raised, a load-bearing steel plate of sufficient height is placed under the steel ribs and the jack is unloaded. A load-bearing steel plate of sufficient height is used to meet the long-term stable support requirements of the steel structure again.

[0036] like Figure 1-8 As shown, a multi-degree-of-freedom steel structure unloading device includes a load-bearing support platform structure 5 and a load-bearing pad 6, and the load-bearing pad 6 is sleeved in the load-bearing support platform structure 5, and a rotating mechanism is installed at the bottom of the load-bearing support platform structure 5, wherein the rotating mechanism includes a rotating base structure 4, including a rotating base plate 41, a rolling groove 43, a rotating base boss 42, and a ball 44, wherein the bottom of the rotating base plate 41 is installed on the XY-axis sliding platform, the rolling groove 43 is opened on the rotating base plate 41, the bottom of the rotating base boss 42 extends into the rolling groove 43 and is fixed to the rotating base plate 41, and the ball 44 is installed in the rolling groove 43;

[0037] The load-bearing support platform structure 5 includes a load-bearing support platform column 51 and a load-bearing support platform 52. The load-bearing support platform column 51 is installed on the outer bottom of the load-bearing support platform 52. The arc on the load-bearing support platform structure 5 is arranged on the weighing support platform 52. A channel is opened on the load-bearing support platform column 51. The load-bearing support platform column 51 is sleeved on the rotating base boss 42 through the channel, and the bottom surface of the load-bearing support platform column 51 is in contact with the ball 44 in the rolling groove 43, so that the load-bearing support platform 5 rotates on the rotating base 4, and the load-bearing pad 6 rotates to release the radial rotation relative to the load-bearing support platform 5 structure caused by the unloading of the steel structure;

[0038] The XY-axis sliding platform includes a Y-direction sliding base plate 3 and an X-direction sliding base plate 14, and the Y-direction sliding base plate 3 and the X-direction sliding base plate 14 are both provided with sliding rails 2, the sliding rails 2 on the Y-direction sliding base plate 3 are arranged along the Y-axis on the Y-direction sliding base plate 3, the sliding rails 2 on the X-direction sliding base plate 14 are arranged along the X-axis on the X-direction sliding base plate 14, and the two ends of the rotating base plate 41 are respectively slidably arranged in the sliding rails 2 on the Y-direction sliding base plate 3, and the bottom of the Y-direction sliding base plate 3 A moving plate 9 is installed, and the two ends of the moving plate 9 are respectively slidably arranged on the sliding rails 2 located on the X-direction sliding bottom plate 14, and a limiting bolt 10 for limiting the sliding of the rotating bottom plate 41 is provided on the Y-direction sliding bottom plate 3. A plurality of bolt holes are provided at the two ends of the two opposite side walls of the Y-direction sliding bottom plate 3 or the two ends of the two opposite side walls of the X-direction sliding bottom plate 14, and the limiting bolts 10 are screwed into the bolt holes, and the roots of the limiting bolts 10 limit the movement of the rotating bottom plate 41 or the moving plate 9, and when the limiting bolts 10 are installed in the bolt holes, there is a gap between the moving plate 9 or the rotating bottom plate 41, which is used to release the X-direction horizontal displacement and the Y-direction horizontal displacement when the support releases the steel structure to unload, and the X-direction sliding bottom plate 14 is also provided with a limiting structure for limiting the sliding of the moving plate 9; and the Y-direction sliding bottom plate is provided with a first roller for assisting the rotating bottom plate to slide on the Y-direction sliding bottom plate, and the X-direction sliding bottom plate is provided with a second roller for assisting the moving plate to slide on the X-direction sliding bottom plate; A steel rib plate 1 is installed at the bottom of the plate 14 through locking bolts 13, and jacks 7 are installed at the four corners and the middle of the bottom of the steel rib plate 1 respectively, and a load-bearing steel plate 8 is also arranged at the bottom of the steel rib plate 1, which is used for the load-bearing steel plate 8 to bear the total pressure of the steel rib plate 1 and the components on the steel rib plate 1 after the jack 7 is lifted or lowered; the steel rib plate 1 is a channel steel, and a cross-shaped reinforcement rib 12 is placed in the groove of the channel steel, and the telescopic end of the jack 7 passes through the channel steel and is fixed to the cross-shaped reinforcement rib 12 by bolts.

[0039] It should be noted that the inner contour of the load-bearing support structure 5 and the outer contour of the load-bearing pad 6 are both set as arcs, which are used to release the horizontal displacement and horizontal angular displacement caused by the unloading of the steel structure with the assistance of the XY-axis sliding platform and the rotating mechanism, and the arc on the load-bearing pad is radially rotated along the arc on the load-bearing support structure to release the vertical angular displacement, so as to ensure the smooth unloading and placement of the steel structure (it should be noted that before the steel structure is unloaded, the following operations need to be performed:

[0040] The inner side of the load-bearing pad is grooved to fit the shape of the upper steel structure. The steel structure is hoisted and fixed in the groove of the load-bearing pad. After the overall welding and installation of the steel structure is completed, the steel structure is unloaded).

[0041] It ensures that the rectangular cross-section steel structure is evenly stressed, and effectively solves the problem in the existing solution that the rectangular steel structure in vertical rotation will cause stress concentration and damage to the steel structure, thereby ensuring the smooth unloading and placement of the steel structure; flanges 11 are respectively provided on the outer walls of the two end portions of the load-bearing pad 6, and the flanges 11 rotate radially along the arc in the load-bearing support structure 5. The premise of movement is that it can only be achieved under the pressure of the steel structure.

[0042] The arc shape of the load-bearing pad 6 can be adjusted according to the shape of the upper steel structure to make the connection between the support and the steel structure tighter;

[0043] The difference in depth between the load-bearing support structure 5 and the load-bearing pad 6 is 10 cm. There is a gap between the flanges 11 on each side of the load-bearing pad 6 and the outer side of the arc on the load-bearing support structure 5. The purpose is to have a gap between the flanges on both sides and the load-bearing support to facilitate the rotation of the load-bearing pad 6 on the load-bearing support structure 5.

[0044] The load-bearing pad 1, the X-axis sliding base plate 14, the Y-axis sliding base plate 3, the load-bearing support structure 5, the bottom of the rotating base structure 4 and the inside of the rolling groove 43 are all sprayed with a polytetrafluoroethylene layer. The surfaces of the first roller 15, the second roller 16 and the load-bearing support structure 5 can be made of stainless steel. The friction characteristics of the material can greatly reduce the friction force at the horizontal sliding and rotation of the support, making it more convenient to release the horizontal displacement and angular displacement when the steel structure is unloaded.

[0045] The positions and quantities of the bolt holes on the Y-direction sliding base plate 3 and the X-direction sliding base plate 14 are adjusted according to actual engineering needs.

[0046] The utility model greatly improves the anti-overturning capacity of the temporary support, and can effectively release the horizontal displacement and angular displacement caused by the unloading of the steel structure, thereby ensuring the smooth unloading and placement of the steel structure; Figure 2As shown, the horizontal displacement includes the X-axis horizontal displacement and the Y-axis horizontal displacement, and the angular displacement includes the horizontal angular displacement and the vertical angular displacement, that is, Figure 5 As shown, the horizontal angular displacement is the displacement caused by the rotation of the bearing support column under the restriction of the rotating base boss, which is assisted by the ball on the rotating base structure installed in the rolling groove, and finally causes the bearing pad to rotate; Figure 5 and Figure 8 As shown, the vertical angular displacement is realized by the load-bearing pad. Under the premise of ensuring the safety of the steel structure, the load-bearing pad can release a certain vertical angular displacement along the arc surface;

[0047] 2. If Figure 2 and Figure 7 As shown, when the jack is lifted, the end of the jack is stuck in the groove under the steel rib plate. When the steel structure is unstable, multiple jacks are lifted synchronously to perform more effective and safer support and remedial work. When the jack is stuck in the groove on the steel rib plate, it abuts against the cross-shaped reinforcement rib in the groove to improve the safety and stability of the device during lifting work.

[0048] 3. The assembled design makes installation and operation easy, which is conducive to high-altitude lifting operations during construction. While solving the problem of unloading the steel structure, it improves the convenience of construction operations and is suitable for promotion and use.

[0049] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited to the above embodiments. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A multi-degree-of-freedom steel structure unloading device, characterized in that: It includes a load-bearing support structure and a load-bearing pad, and the load-bearing pad is sleeved in the load-bearing support structure. A rotating mechanism is installed at the bottom of the load-bearing support structure, and an XY-axis sliding platform is installed at the bottom of the rotating mechanism. The interior of the load-bearing support structure and the exterior contour of the load-bearing pad are both set as circular arcs. When the steel structure is unloaded, with the assistance of the XY-axis sliding platform and the rotating mechanism, the load-bearing support structure performs X-axis sliding, Y-axis sliding and horizontal rotation operations to release the horizontal displacement and horizontal angular displacement generated when the steel structure is unloaded. The arc on the load-bearing pad is radially rotated along the arc on the load-bearing support structure to release the vertical angular displacement, thereby ensuring the smooth unloading and placement of the steel structure.

2. A multi-degree-of-freedom steel structure unloading device according to claim 1, characterized in that: Flanges are respectively arranged on the outer walls of both ends of the load-bearing pad, and the flanges are radially rotated along the arc in the load-bearing support structure.

3. The multi-degree-of-freedom steel structure unloading device according to claim 1, characterized in that: The difference between the depth of the load-bearing support structure and the depth of the load-bearing pad is 5-15 cm, and there is a gap between the flanges on each side of the load-bearing pad and the outer side of the arc on the load-bearing support structure.

4. The multi-degree-of-freedom steel structure unloading device according to claim 1, characterized in that: The rotating mechanism comprises a rotating base structure, the bottom of the load-bearing support structure is rotatably sleeved on the rotating base structure, and the bottom of the rotating base structure is slidably mounted on the XY axis sliding platform.

5. The multi-degree-of-freedom steel structure unloading device according to claim 4, characterized in that: The rotating base structure includes a rotating base plate, a rolling groove, a rotating base boss, and a ball. The bottom of the rotating base plate is installed on the XY-axis sliding platform. The rolling groove is opened on the rotating base plate. The bottom of the rotating base boss extends into the rolling groove and is fixed to the rotating base plate. The ball is installed in the rolling groove; the load-bearing support platform structure includes a load-bearing support platform column and a load-bearing support platform. The load-bearing support platform column is installed on the outer bottom of the load-bearing support platform. The arc on the load-bearing support platform structure is arranged on the weighing support platform. A channel is opened on the load-bearing support platform column. The load-bearing support platform column is sleeved on the rotating base boss through the channel, and the bottom surface of the load-bearing support platform column contacts with the ball in the rolling groove, which is used for the load-bearing support platform structure to rotate on the rotating base, so that the load-bearing pad rotates to release the radial rotation relative to the load-bearing support platform structure caused by the unloading of the steel structure.

6. The multi-degree-of-freedom steel structure unloading device according to claim 5, characterized in that: The XY-axis sliding platform comprises a Y-direction sliding bottom plate and an X-direction sliding bottom plate, and sliding tracks are provided on the Y-direction sliding bottom plate and the X-direction sliding bottom plate. The sliding track on the Y-direction sliding bottom plate is arranged along the Y-axis on the Y-direction sliding bottom plate, and the sliding track on the X-direction sliding bottom plate is arranged along the X-axis on the X-direction sliding bottom plate, and both ends of the rotating bottom plate are respectively slidably arranged in the sliding track on the Y-direction sliding bottom plate, a moving plate is installed at the bottom of the Y-direction sliding bottom plate, and both ends of the moving plate are respectively slidably arranged on the sliding track on the X-direction sliding bottom plate, a limiting structure for limiting the sliding of the rotating bottom plate is provided on the Y-direction sliding bottom plate, and a limiting structure for limiting the sliding of the moving plate is also provided on the X-direction sliding bottom plate.

7. The multi-degree-of-freedom steel structure unloading device according to claim 6, characterized in that: The limiting structure is a limiting bolt, and a plurality of bolt holes are provided at both ends of the two opposite side walls of the Y-direction sliding base plate or at both ends of the two opposite side walls of the X-direction sliding base plate. The limiting bolts are screwed into the bolt holes, and the roots of the limiting bolts limit the movement of the rotating base plate or the moving plate.

8. The multi-degree-of-freedom steel structure unloading device according to claim 1, characterized in that: A steel rib is installed at the bottom of the X-axis sliding bottom plate through locking bolts, and jacks are installed at the four corners and the middle of the bottom of the steel rib respectively. The steel rib is a channel steel, and a cross-shaped reinforcement rib is placed in the groove of the channel steel. The telescopic end of the jack passes through the channel steel and is fixed to the cross-shaped reinforcement rib by bolts.

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