Impact resistance testing equipment for building curtain wall

Through the retraction and placement of the electromagnet and drive motor drive rope, the automatic control of the impact resistance performance testing equipment of the building curtain wall is realized, solving the problems of cumbersome manual operation and safety hazards, and improving the testing efficiency and safety.

CN223064971UActive Publication Date: 2025-07-04李好来
View PDF 1 Cites 0 Cited by

Patent Information

Application Number
CN202421974068.5
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-08-15
Publication Date
2025-07-04
Estimated Expiration
2034-08-15

AI Technical Summary

Technical Problem

Existing architectural curtain wall impact resistance testing equipment requires frequent manual operation when releasing impact objects, resulting in low working efficiency and safety hazards.

Method used

The electromagnet and driving motor drive rope are used to automatically control the release and fixation of the impact test block, and the automatic operation of the impact test block is achieved through the adsorption and power failure of the electromagnet.

Benefits of technology

It improves testing efficiency, avoids the tedious process of manual operation, reduces the risk of injury to staff, and enhances the safety of tests.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN223064971U_ABST
    Figure CN223064971U_ABST
Patent Text Reader

Abstract

The utility model discloses building curtain wall impact resistance testing equipment which comprises a curtain wall frame and a mounting plate fixedly mounted on one side of the curtain wall frame through bolts, and a testing assembly is mounted on the mounting plate. The testing assembly comprises a supporting plate arranged on one side of the mounting plate, a U-shaped plate fixed on the upper surface of the supporting plate and a first driving motor fixed on one side of the U-shaped plate through a bolt. A worker does not need to release the connection of the impact test block, the operation is time-saving and labor-saving, the working efficiency is improved, and the impact test area does not need to involve the worker, so that the situation that the curtain wall plate is impacted and broken and splashes to injure the worker accidentally is effectively avoided, the operation safety is improved, the use effect is better, and the practicability is high. And actual use requirements are met.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The utility model relates to the technical field of impact resistance testing of building curtain walls, and specifically relates to a testing device for the impact resistance performance of building curtain walls. Background Technique

[0002] At present, curtain wall structures are adopted on the exteriors of many high-rise buildings, including glass curtain walls, stone curtain walls, and metal panel curtain walls, etc. Compared with plastered brick walls, concrete walls, etc., glass curtain walls have the characteristics of light weight and flexible design, and have a modern aesthetic feeling. In addition, they are relatively convenient for updating and maintenance. Stone curtain walls and metal panel curtain walls also play a role in decorating the exterior wall and have an elegant and solemn effect.

[0003] After inquiry, the publication (announcement) number is; CN204286736U, which discloses a testing device for the impact resistance performance of building curtain walls. In this technology, it is disclosed that "including a vertically arranged suspension frame body and a traction frame body, a curtain wall to be tested is vertically installed on the suspension frame body, the top of the suspension frame body is fixedly connected to one end of a suspension rope, the other end of the suspension rope is connected to an impact object, and one end of a connecting rope is also connected to the impact object, and the other end of the connecting rope is detachably connected to a release switch, etc. The technical solutions have the advantages of simple and practical structure, good adaptability, being able to adapt to curtain walls of different sizes, and being very convenient for performance testing. The curtain wall is fixed on the suspension frame body, and the height of the impact object is controlled by a winch. After the impact object is released and falls, an instantaneous impact effect on the curtain wall is achieved, which meets the requirements of the curtain wall impact resistance performance detection standard and ensures the accuracy of the test" and other technical effects.

[0004] When the above design is in use, although it has a simple and practical structure, good adaptability, can adapt to curtain walls of different sizes, and the performance testing is very convenient, ensuring the accuracy of the test, during the release process of the impact object, it is necessary to manually release the release switch frequently. Through multiple tests, it is time-consuming and laborious for the staff, reducing the work efficiency. Moreover, during the impact, it is difficult for the staff to leave this area. When the curtain wall panel breaks during the impact, it is easy to splash and injure the staff, reducing the use effect of the device. Therefore, we propose a testing device for the impact resistance performance of building curtain walls to solve the above existing problems. Content of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the utility model provides a testing device for the impact resistance performance of building curtain walls, which solves the problems of frequent manual release of the release switch and easy splashing and injuring of the staff.

[0006] To achieve the above object, the utility model is realized by the following technical solutions: A building curtain wall impact resistance testing device, including a curtain wall frame and a mounting plate fixedly installed on one side of the curtain wall frame by bolts. A testing component is installed on the mounting plate. The testing component includes a support plate arranged on one side of the mounting plate, a U-shaped plate fixed on the upper surface of the support plate, and a first driving motor fixed on one side of the U-shaped plate by bolts. The output end of the first driving motor is fixed with a rotating shaft, and a winding rod is fixed on the surface of the rotating shaft. A rope is wound around the surface of the winding rod. A collision testing block is arranged below the support plate. One end of the rope is fixed at the center of the upper surface of the collision testing block. An electromagnet one is fixedly installed on the upper surface of the collision testing block. An electromagnet two is fixed on the lower surface of the support plate close to the electromagnet one. A circular hole is opened on the surface of the support plate, and the rope slides in the circular hole opened on the support plate.

[0007] Preferably, the two ends of the rotating shaft are rotatably connected to the U-shaped plate through bearings. The other end of the rope is fixedly connected to the surface of the winding rod. The electromagnet one and the electromagnet two are of opposite magnetic poles.

[0008] Preferably, a rectangular hole is opened on the surface of the support plate close to the U-shaped plate. A support frame is fixed on the side of the support plate close to the rectangular hole. An installation groove is opened on the surface of the support frame, and a pair of symmetrically arranged limiting wheels are arranged in the installation groove. The limiting wheels are rotatably connected to the support frame through rotating shafts. The rope is located between the two limiting wheels.

[0009] Preferably, an annular groove is opened on the inner side of the support plate close to the circular hole. A plurality of groups of equally spaced rolling balls are arranged in the annular groove, and the rolling balls are rotatably installed in the annular groove.

[0010] Preferably, symmetrically arranged limiting pins are fixed on the upper surface of the curtain wall frame. A pressing plate is slidably connected between the two limiting pins. A spring is wound around the surface of the limiting pin. The two ends of the spring are respectively fixedly connected to the limiting pin and the pressing plate. A positioning strip is arranged below the pressing plate. The positioning strip is fixedly connected to the curtain wall frame. A through hole adapted to the limiting pin is opened on the surface of the pressing plate. The pressing plate and the limiting pin are slidably connected through this through hole.

[0011] Preferably, a rectangular groove is opened on the surface of the mounting plate. A pair of symmetrically arranged limiting rods are arranged in the rectangular groove. A moving block is slidably connected between the two limiting rods. A threaded rod is arranged between the two limiting rods. The moving block is threadedly connected to the threaded rod. A second driving motor is fixedly installed on the upper surface of the mounting plate by bolts. The output end of the second driving motor is fixedly connected to one end of the threaded rod. The moving block is fixedly connected to the support plate.

[0012] Preferably, both ends of the limiting rod are fixedly connected to the mounting plate, both ends of the threaded rod are rotatably connected to the mounting plate through bearings, a sliding hole adapted to the limiting rod is formed on the surface of the moving block, and the moving block and the limiting rod are slidably connected through this sliding hole.

[0013] Beneficial effects

[0014] The utility model provides a building curtain wall impact resistance testing device. Compared with the prior art, the following beneficial effects are achieved:

[0015] For this building curtain wall impact resistance testing device, through the testing component, there is no need for staff to release the connection of the impact test block for release operation. This operation saves time and effort and improves work efficiency. Moreover, this impact test area does not involve staff, thus effectively avoiding the situation of splashing and injuring personnel due to the impact and breakage of the curtain wall board, improving the safety of operation, having better use effect, and meeting the actual use requirements. Brief description of the drawings

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 It is a schematic diagram of the connection structure of the limiting rod, threaded rod and other connecting parts of the utility model;

[0018] Figure 3 It is a schematic diagram of the connection structure of the second electromagnet, ball and other connecting parts of the utility model;

[0019] Figure 4 It is a schematic diagram of the connection structure of the limit pin, spring and other connecting parts of the utility model.

[0020] In the figure: 1, curtain wall frame; 2, mounting plate; 3, testing component; 301, support plate; 302, U-shaped plate; 303, winding roller; 304, rope; 305, impact test block; 306, first electromagnet; 307, second electromagnet; 308, ball; 309, first driving motor; 310, support frame; 311, limiting wheel; 312, extrusion plate; 313, limit pin; 314, spring; 315, positioning strip; 316, limiting rod; 317, threaded rod; 318, second driving motor; 319, moving block. Specific embodiments

[0021] Next, the technical solutions in the embodiments of the utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the utility model.

[0022] As Figure 1 shown:

[0023] A building curtain wall impact resistance testing device, comprising a curtain wall frame 1 and a mounting plate 2 fixedly installed on one side of the curtain wall frame 1 by bolts.

[0024] In this implementation: The existing device {publication (announcement) number}: CN204286736U discloses a building curtain wall impact resistance testing device. To solve the technical problems existing in this prior art, as disclosed in the background art above, "When this design is in use, although it is simple and practical in structure, has good adaptability, can adapt to curtain walls of different sizes, and the performance testing is very convenient, ensuring the accuracy of the testing. However, during the release process of the impact object, it is necessary for workers to frequently release the release switch manually. Through multiple tests, it is time-consuming and laborious for workers, reducing work efficiency. Moreover, during the impact, it is difficult for workers to leave this area. When the curtain wall panel breaks upon impact, it is easy to splash and injure workers, reducing the use effect of the device." In combination with the use, this problem is obviously a real and relatively difficult problem to solve. In view of this, to solve this technical problem, a testing component 3 is added to this application document, and all the power equipment involved in this product is powered by an external power supply.

[0025] Furthermore:

[0026] As Figures 1-4 shown:

[0027] A testing component 3 is installed on the mounting plate 2. The testing component 3 includes a support plate 301 arranged on one side of the mounting plate 2, a U-shaped plate 302 fixed on the upper surface of the support plate 301, and a driving motor 309 fixed on one side of the U-shaped plate 302 by bolts. The output end of the driving motor 309 is fixed with a rotating shaft, and a winding rod 303 is fixed on the surface of the rotating shaft. A rope 304 is wound around the surface of the winding rod 303. An impact testing block 305 is arranged below the support plate 301. One end of the rope 304 is fixed at the center of the upper surface of the impact testing block 305. An electromagnet 306 is fixedly installed on the upper surface of the impact testing block 305. An electromagnet 307 is fixed on the lower surface of the support plate 301 near the electromagnet 306. A circular hole is formed on the surface of the support plate 301, and the rope 304 slides in the circular hole formed on the support plate 301. Both ends of the rotating shaft are rotatably connected to the U-shaped plate 302 through bearings. The other end of the rope 304 is fixedly connected to the surface of the winding rod 303. The electromagnet 306 and the electromagnet 307 are of opposite magnetic poles.

[0028] In this embodiment: When the impact resistance test equipment for building curtain walls is in use, first install the curtain wall test piece on the curtain wall frame 1, then start the first driving motor 309, which drives the winding roller 303 to rotate. The rope 304 is wound by the winding roller 303, thereby driving the impact test block 305 and the first electromagnet 306 to move upward synchronously. When the first electromagnet 306 contacts the second electromagnet 307, the external power supply supplies power to the first electromagnet 306 and the second electromagnet 307 at this time. The first electromagnet 306 and the second electromagnet 307 generate magnetism and adsorb each other, fixing the impact test block 305 at the bottom below the support plate 301. Then, reverse-start the first driving motor 309 and drive the winding roller 303 to rotate in the reverse direction, thereby releasing the rope 304 until the released section of the rope 304 is sufficient for the distance where the impact test block 305 contacts the curtain wall test piece box. Stop the operation of the first driving motor 309. Then, cut off the power supply to the first electromagnet 306 and the second electromagnet 307. At this time, the magnetism of the first electromagnet 306 and the second electromagnet 307 disappears. At this time, the impact test block 305 falls due to its own gravity and drives the rope 304 to move downward to conduct an impact test on the curtain wall test piece. Repeat the above operation to conduct multiple impact tests on the curtain wall test piece. Through this operation, there is no need for staff to release the connection of the impact test block 305. This operation saves time and effort and improves work efficiency. Moreover, this impact test area does not involve staff, thus effectively avoiding the situation where the curtain wall panel is broken by impact and splashes to injure people, improving the safety of the operation, having a better use effect, and meeting the actual use requirements.

[0029] Furthermore;

[0030] In an alternative embodiment, a rectangular hole is opened on one side of the surface of the support plate 301 close to the U-shaped plate 302. A support frame 310 is fixed on one side of the support plate 301 close to the rectangular hole. An installation groove is opened on the surface of the support frame 310, and symmetrically arranged limiting wheels 311 are arranged in the installation groove. The limiting wheels 311 are rotationally connected to the support frame 310 through a rotating shaft, and the rope 304 is located between the two groups of limiting wheels 311.

[0031] In this embodiment: Through the setting of the support frame 310 and the limiting wheels 311, the rope 304 can be supported and limited. When the rope 304 is released, the fluffy rope 304 continuously moves downward along the rectangular hole opened on the support plate 301 (in this process, two rope segments fall, one end is at the connection of the two groups of limiting wheels 311, and the other end is at the release point of the winding roller 303). Through this operation, compared with when the rope 304 falls on the upper surface of the support plate 301, due to continuous release and superposition, when the impact test block 305 moves downward due to its own gravity and drives the rope 304 to move downward, the situation of entanglement can be effectively avoided, further improving the use effect of the device.

[0032] Furthermore;

[0033] In an alternative embodiment, an annular groove is formed inside the support plate 301 near one side of the circular hole, and a plurality of groups of equally spaced rolling balls 308 are arranged in the annular groove, and the rolling balls 308 are rotatably installed in the annular groove.

[0034] In this embodiment: when the rope 304 moves in the circular hole formed in the support plate 301, the friction between the rope 304 and the support plate 301 can be reduced by the arrangement of the rolling balls 308.

[0035] Furthermore;

[0036] In an alternative embodiment, symmetrically arranged limit pins 313 are fixed on the upper surface of the curtain wall frame 1, an extrusion plate 312 is slidably connected between the two limit pins 313, a spring 314 is wound around the surface of the limit pin 313, and the two ends of the spring 314 are respectively fixedly connected to the limit pin 313 and the extrusion plate 312. A positioning strip 315 is arranged below the extrusion plate 312, and the positioning strip 315 is fixedly connected to the curtain wall frame 1. Through holes adapted to the limit pins 313 are formed on the surface of the extrusion plate 312, and the extrusion plate 312 and the limit pins 313 are slidably connected through these through holes.

[0037] In this embodiment: the curtain wall test piece is placed on the curtain wall frame 1 and abuts against the surface of the positioning strip 315 at the same time, so as to limit the placement of the curtain wall test piece. Before that, by pulling the extrusion plate 312, it slides on the limit pin 313 and compresses the spring 314. When the placement of the curtain wall test piece is completed, the extrusion plate 312 is released. At this time, the spring 314 rebounds and drives the extrusion plate 312 to move downward to abut and fix the curtain wall test piece, avoiding the situation that the curtain wall test piece moves due to repeated impacts in the later stage, and further improving the use effect of the device.

[0038] Furthermore;

[0039] In an alternative embodiment, a rectangular groove is formed on the surface of the mounting plate 2, symmetrically arranged limit rods 316 are arranged in the rectangular groove, a moving block 319 is slidably connected between the two limit rods 316, a threaded rod 317 is arranged between the two limit rods 316, the moving block 319 is threadedly connected to the threaded rod 317, a second driving motor 318 is fixedly installed on the upper surface of the mounting plate 2 through bolts, the output end of the second driving motor 318 is fixedly connected to one end of the threaded rod 317, the moving block 319 is fixedly connected to the support plate 301, the two ends of the limit rod 316 are respectively fixedly connected to the mounting plate 2, the two ends of the threaded rod 317 are rotatably connected to the mounting plate 2 through bearings, a sliding hole adapted to the limit rod 316 is formed on the surface of the moving block 319, and the moving block 319 and the limit rod 316 are slidably connected through this sliding hole.

[0040] In this embodiment, when it is necessary to adjust the distance between the impact test block 305 and the curtain wall to be tested, and different impact forces are applicable, by starting the second driving motor 318, the threaded rod 317 is driven to rotate. Since the threaded rod 317 is threadedly connected to the moving block 319, the moving block 319 is driven to move, and at the same time, it slides on the limiting rod 316. The limiting rod 316 is used to limit the moving block 319, so that the moving block 319 is more stable during the moving process. With the movement of the moving block 319, the support plate 301 is driven to move, and thus the distance between the impact test block 305 and the curtain wall to be tested can be adjusted, improving the flexibility and practicability of the device.

[0041] The working principle and use process of the utility model are as follows: when using the building curtain wall impact resistance test equipment, firstly, the curtain wall test piece is placed on the curtain wall frame 1, and at the same time, it conflicts with the surface of the positioning strip 315, so as to place and limit the curtain wall test piece. Before that, by pulling the extrusion plate 312, it slides on the limit pin 313 and compresses the spring 314. When the curtain wall test piece is placed, the extrusion plate 312 is released. At this time, the spring 314 rebounds and drives the extrusion plate 312 to move downward to contact and squeeze the curtain wall test piece to fix it, so as to avoid the movement of the curtain wall test piece caused by repeated impact in the later stage, and further improve the use effect of the device. Then, the drive motor 309 is started, and the winding roller 303 is driven to move. The rope 304 is rotated, and the rope 304 is reeled in by the reeling roller 303, thereby driving the impact test block 305 and the electromagnet 1 306 to move upward synchronously, until the electromagnet 1 306 contacts the electromagnet 2 307, at which time the external power supply supplies power to the electromagnet 1 306 and the electromagnet 2 307, and the electromagnet 1 306 and the electromagnet 2 307 generate magnetism and adsorb, and fix the impact test block 305 to the bottom below the support plate 301, and then reversely start the drive motor 1 309, and drive the reeling roller 303 to rotate in the opposite direction, thereby releasing the rope 304, until the released section of the rope 304 is sufficient to contact the impact test block 305 with the curtain wall test piece box, stop the operation of the drive motor 1 309, and then reel in the rope 304. 6 and electromagnet 2 307 are powered off, at which time the magnetism of electromagnet 1 306 and electromagnet 2 307 disappears, and at this time the impact test block 305 falls due to its own gravity, and drives the rope 304 to move downward to perform an impact test on the curtain wall test piece, and repeats the above operation to perform impact tests on the curtain wall test piece for multiple times. Through this operation, there is no need for staff to disconnect and release the impact test block 305, which saves time and effort and improves work efficiency. In addition, there is no need to involve staff in the impact test area, thereby effectively avoiding the curtain wall panel from crashing and breaking and causing splashing and accidentally injuring people, improving the safety of operation, and achieving better use effect, meeting actual use needs. When the rope 304 moves in the circular hole opened in the support plate 301, The setting of the ball bearing 308 can reduce the friction between the rope 304 and the support plate 301. At the same time, the setting of the support frame 310 and the limiting wheel 311 can support and limit the rope 304. When the rope 304 is released, the fluffy rope 304 continues to move down along the rectangular hole opened in the support plate 301 (in this process, two rope segments fall, one end is located at the connection between the two sets of limiting wheels 311, and the other end is the release point of the winding rod 303). Through this operation, when the rope 304 falls on the upper surface of the support plate 301, due to the continuous release and superposition, when the impact test block 305 moves downward due to its own gravity, it also drives the rope 304 to move downward, thereby effectively avoiding entanglement, further improving the use effect of the device.When it is necessary to adjust the distance between the impact test block 305 and the curtain wall to be tested, when different impact forces are applied, by starting the second drive motor 318, the threaded rod 317 is driven to rotate. Since the threaded rod 317 is threadedly connected to the moving block 319, the moving block 319 is driven to move, and at the same time, it slides on the limiting rod 316. The limiting rod 316 is used to limit the moving block 319, so that the moving block 319 is more stable during the moving process. As the moving block 319 moves, the support plate 301 is driven to move, so that the distance between the impact test block 305 and the curtain wall to be tested can be adjusted, improving the flexibility and practicality of the device.

[0042] At the same time, the content not described in detail in this specification belongs to the prior art well known to those skilled in the art.

Claims

1. A building curtain wall impact resistance test device, comprising a curtain wall frame (1) and a mounting plate (2) fixedly installed on one side of the curtain wall frame (1) by bolts, characterized in that, A test component (3) is installed on the mounting plate (2). The test component (3) includes a support plate (301) arranged on one side of the mounting plate (2), a U-shaped plate (302) fixed on the upper surface of the support plate (301), and a first driving motor (309) fixed on one side of the U-shaped plate (302) by bolts. A rotating shaft is fixed to the output end of the first driving motor (309), and a winding rod (303) is fixed on the surface of the rotating shaft. A rope (304) is wound around the surface of the winding rod (303). An impact test block (305) is arranged below the support plate (301). One end of the rope (304) is fixed at the center of the upper surface of the impact test block (305). An electromagnet one (306) is fixedly installed on the upper surface of the impact test block (305). An electromagnet two (307) is fixed on the lower surface of the support plate (301) near the electromagnet one (306). A circular hole is formed on the surface of the support plate (301), and the rope (304) slides in the circular hole formed in the support plate (301).

2. The impact resistance test equipment for building curtain walls according to claim 1, characterized in that: Both ends of the rotating shaft are rotatably connected to the U-shaped plate (302) through bearings. The other end of the rope (304) is fixedly connected to the surface of the winding rod (303). The electromagnet one (306) and the electromagnet two (307) are of opposite magnetic poles.

3. The impact resistance test device for building curtain walls according to claim 2, characterized in that: A rectangular hole is formed on the surface of the support plate (301) near the U-shaped plate (302). A support frame (310) is fixed on one side of the support plate (301) near the rectangular hole. An installation groove is formed on the surface of the support frame (310), and symmetrically arranged limiting wheels (311) are arranged in the installation groove. The limiting wheels (311) are rotatably connected to the support frame (310) through rotating shafts. The rope (304) is located between the two groups of limiting wheels (311).

4. An impact resistance test device for building curtain walls according to claim 3, characterized in that: An annular groove is formed inside the support plate (301) near the circular hole, and multiple groups of equally spaced balls (308) are arranged in the annular groove. The balls (308) are rotatably installed in the annular groove.

5. The impact resistance test device for building curtain walls according to claim 1, wherein: Symmetrically arranged limiting pins (313) are fixed on the upper surface of the curtain wall frame (1). A pressing plate (312) is slidably connected between the two limiting pins (313). A spring (314) is wound around the surface of the limiting pin (313). Both ends of the spring (314) are fixedly connected to the limiting pin (313) and the pressing plate (312) respectively. A positioning strip (315) is arranged below the pressing plate (312). The positioning strip (315) is fixedly connected to the curtain wall frame (1). A through hole adapted to the limiting pin (313) is formed on the surface of the pressing plate (312). The pressing plate (312) and the limiting pin (313) are slidably connected through this through hole.

6. The impact resistance test device for building curtain walls according to claim 1, characterized in that: The surface of the mounting plate (2) is provided with a rectangular groove, and symmetrically arranged limiting rods (316) are arranged in the rectangular groove. A moving block (319) is slidably connected between the two groups of limiting rods (316). A threaded rod (317) is arranged between the two groups of limiting rods (316). The moving block (319) is threadedly connected to the threaded rod (317). The upper surface of the mounting plate (2) is fixedly installed with a second driving motor (318) through bolts. The output end of the second driving motor (318) is fixedly connected to one end of the threaded rod (317). The moving block (319) is fixedly connected to the support plate (301).

7. The impact resistance testing device for building curtain walls according to claim 6, wherein: Both ends of the limiting rod (316) are fixedly connected to the mounting plate (2). The surfaces of both ends of the threaded rod (317) are rotatably connected to the mounting plate (2) through bearings. The surface of the moving block (319) is provided with a sliding hole adapted to the limiting rod (316). The moving block (319) and the limiting rod (316) are slidably connected through this sliding hole.

Citation Information

Patent Citations

  • Equipment for testing impact-resistant performance of curtain wall

    CN204286736U