CN118792955A - A safety hanger device for bridge inspection and maintenance - Google Patents

Abstract

The invention belongs to the technical field of building maintenance and construction, and relates to a safety hanging bracket device for bridge inspection and maintenance; comprises a base; the top of the base is connected with a horizontal rotating assembly, the top of the horizontal rotating assembly is connected with a turnover pushing assembly, the top of the turnover pushing assembly is connected with a lifting assembly, and the lifting assembly is connected with a first support bracket; the first support bracket moves to one side outside the bridge through the horizontal rotating assembly, the lifting assembly and the overturning pushing assembly and is in a vertical state; one end of the first support bracket is rotatably connected with a second rotating box; the second rotating box is hinged with a second support bracket, and the second support bracket can move to be vertical to the first support bracket; according to the invention, the first support bracket can be arranged outside the bridge, and the second support bracket is moved to the bottom surface of the bridge, so that the bottom of the bridge is convenient to overhaul, and the inspection efficiency and the inspection effect are improved.

Description

A safety hanger device for bridge inspection and maintenance

Technical Field

The invention belongs to the technical field of building maintenance construction and relates to a safety hanger device for bridge inspection and maintenance.

Background Art

A bridge refers to a structure built on a body of water, used to connect two banks to facilitate the passage of vehicles and pedestrians. Since bridges bear the pressure of vehicles for a long time, they need to be inspected and maintained regularly to ensure their safety and reliability and to ensure smooth travel for people. When inspecting and repairing bridges, the current practice is to hang a hanging basket on the railing on one side of the bridge, so that people can stand in it to inspect both sides of the bridge. However, this method has safety hazards because the hanging basket is hung on the railing and is not fixed, which may cause the hanging basket to shake during operation. This unstable situation poses a greater safety risk to the installation operation. In addition, the heights of different bridges are different, and the length of the hanging basket hanging on the railing on one side of the bridge will also increase, causing the hanging basket to shake more obviously. When the width of the bridge is large, the middle of its bottom surface is likely to be uninspected, thereby reducing the inspection efficiency. Therefore, improvements need to be made based on the above problems.

Summary of the invention

The present invention overcomes the deficiencies of the prior art and provides a safety hanger device for bridge inspection and maintenance; the present invention is achieved through the following technical solutions.

A safety hanger device for bridge inspection and maintenance, comprising a base; a horizontal rotation assembly is connected to the top of the base, a flip and push assembly is connected to the top of the horizontal rotation assembly, a lifting assembly is connected to the top of the flip and push assembly, and the lifting assembly is connected to a first support bracket; the first support bracket rotates horizontally along the bridge deck under the action of the horizontal rotation assembly, the first support bracket is lifted and lowered along the height direction of the bridge under the action of the lifting assembly, and the first support bracket moves to one side of the outside of the bridge and is in a vertical state under the action of the flip and push assembly;

The flip push-out assembly comprises a first electric push rod and an adjustment box; the two ends of the first electric push rod are respectively hinged with the horizontal rotation assembly and the lifting assembly; one side of the bottom of the lifting assembly is hinged with one side of the adjustment box; a second screw is rotatably connected inside the adjustment box, and one end of the second screw is connected to the output shaft of the first self-locking motor; the outer side of the second screw is threadedly connected to an articulated seat, and the upper end of the articulated seat is movably hinged with a second electric push rod, and the output shaft of the second electric push rod is movably hinged with the bottom surface of the lifting assembly;

One end of the first support bracket is rotatably connected to the second rotating box; the second rotating box is hinged to the second support bracket, and the second support bracket rotates along the hinge axis until it is buckled on the first support bracket or unfolded relative to the first support bracket; the second rotating box is hinged to the third electric push rod, and the output shaft of the third electric push rod is movably hinged to the second support bracket.

Furthermore, the horizontal rotation assembly includes a first rotation box and a mounting seat; the first rotation box is installed on the top surface of the base, and the top surface of the first rotation box is rotatably connected to the mounting seat; the adjustment box is connected to the top surface of the mounting seat.

Furthermore, the lifting assembly includes a rotating plate, a column and a first screw rod; one end of the adjustment box is movably hinged to one end of the rotating plate; the rotating plate is rotatably connected to the first screw rod, and the first supporting bracket is connected to the first screw rod.

Furthermore, columns are installed at the four ends of the top surface of the rotating plate; sliding grooves are opened on the opposite surfaces of the four columns, and guide rods are vertically fixed in the sliding grooves opened by the two columns on one side, and the first screw rods are vertically rotatably connected in the sliding grooves opened by the two columns on the other side, and the upper end of the first screw rod is connected to the output shaft of the first stepper motor.

Furthermore, a moving block is provided at the lower end of the guide rod and the first screw rod, the moving block on the guide rod is slidably connected to the guide rod, and the moving block on the first screw rod is threadedly connected to the first screw; a connecting rod is fixedly connected between the moving block on the guide rod on the same side and the moving block on the first screw rod, connecting plates are fixedly connected at both ends of the two connecting rods, a supporting plate is horizontally fixed between the two connecting plates, and a second self-locking motor is installed on the supporting plate; the second self-locking motor is connected to the third screw rod through a driving mechanism, and both ends of the third screw rod are fixedly connected to the inner wall of the first supporting bracket.

Furthermore, a mounting block is installed on the supporting plate; the driving mechanism includes a driving gear and a driven gear; a mounting opening is provided on the top surface of the mounting block, a driven gear is provided in the mounting opening, the lower end of the driven gear is meshed with the driving gear, and one end of the driving gear is connected to the output shaft of the second self-locking motor; an internal thread opening is provided in the middle of the driven gear, and the third screw passes through the internal thread opening and is threadedly connected to the driven gear; guide rods are provided on both sides of the lower end of the third screw, and the two guide rods respectively pass through both sides of the mounting block, and both ends of the guide rods are fixed to the inner wall of the first supporting bracket.

Furthermore, a third supporting bracket is provided at the other end of the second supporting bracket, and a fourth screw is provided inside the handrails on both sides of the second supporting bracket. One end of the fourth screw is connected to the output shaft of the second stepper motor, and the other end of the fourth screw is threadedly connected to the handrails on both sides of the third supporting bracket.

Furthermore, mounting grooves are provided on both sides of one end of the third supporting bracket away from the second supporting bracket, a fixing rod is vertically installed inside the mounting groove, a spring is sleeved on the outside of the fixing rod, the lower end of the spring abuts against the bottom surface of the mounting groove, and the upper end of the spring is connected to a protective plate, both ends of the protective plate are placed in the mounting grooves on both sides, and both ends of the protective plate are sleeved on the outside of the fixing rod; a protective net is connected between the protective plate and the third supporting bracket.

Furthermore, a first supporting net is installed on the bottom surface of the second supporting bracket, and a second supporting net is installed on the bottom surface of the third supporting bracket.

The beneficial effects of the present invention compared with the prior art are as follows:

The present invention can change the position of the device through the cooperation of the first rotating box and the mounting seat, which is convenient for moving the device and inspecting the bridge; through the cooperation of the adjustment box and the rotating plate, the state of the first support bracket can be adjusted, which is convenient for placing the first support bracket on the outside of the bridge; through the cooperation of the driven gear and the third screw rod, the lifting and lowering of the first support bracket can be controlled, so as to facilitate controlling the lifting and lowering of the first support bracket according to the height of different bridges, and then controlling the height of the second support bracket and the third support bracket, thereby improving the detection efficiency; through the cooperation of the second support bracket and the third support bracket, it is convenient to extend the inspection distance of the bottom surface of the bridge and improve the inspection effect; the device improves the inspection efficiency and inspection effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall three-dimensional structure of the present invention;

FIG2 is a partial cross-sectional structural schematic diagram of the present invention;

FIG3 is a schematic diagram of the three-dimensional structure of a rotating assembly and a part of a lifting assembly of the present invention;

FIG4 is a schematic diagram of the three-dimensional structure of the lifting assembly and the first supporting bracket of the present invention;

FIG5 is a bottom-view three-dimensional structural diagram of the second support bracket and the third support bracket of the present invention;

FIG6 is a schematic diagram of the three-dimensional structure of the second support bracket and the third support bracket of the present invention;

FIG7 is a schematic diagram of a three-dimensional structure of a third supporting bracket of the present invention;

FIG8 is a schematic diagram of the internal cross-sectional structure of the third support bracket of the present invention;

Serial number in the picture:

1. Base; 2. First rotating box; 3. Mounting seat; 4. Adjusting box; 5. Rotating plate; 6. Post; 7. Guide rod; 8. First screw; 9. First stepping motor; 10. Moving block; 11. Connecting rod; 12. Connecting plate; 13. Supporting plate; 14. First electric push rod; 15. Second screw; 16. First self-locking motor; 17. Articulated seat; 18. Second electric push rod; 19. Mounting block; 20. Driven gear; 21. Driving gear; 22. Second self-locking motor; 23. Third screw; 24. Guide rod; 25. First supporting bracket; 26. Second rotating box; 27. Second supporting bracket; 28. First supporting net; 29. Third electric push rod; 30. Third supporting bracket; 31. Fourth screw; 32. Second stepping motor; 33. Second supporting net; 34. Fixed rod; 35. Spring; 36. Protective plate; 37. Protective net.

DETAILED DESCRIPTION

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail in conjunction with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The technical solutions of the present invention are described in detail below in conjunction with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

Referring to Figures 1 to 8, this embodiment proposes a safety hanger device for bridge inspection and maintenance, including a base 1, the top of the base 1 is connected to a horizontal rotation component, the top of the horizontal rotation component is connected to a flip and ejection component, and the top of the flip and ejection component is connected to a lifting component; wherein the horizontal rotation component includes a first rotation box 2 and a mounting seat 3; the flip and ejection component includes a first electric push rod 14 and an adjustment box 4; the lifting component includes a rotating plate 5, a column 6 and a first screw 8.

A first rotating box 2 is installed in the middle of the top surface of the base 1, and the top surface of the first rotating box 2 is rotatably connected to a mounting seat 3. A rotating motor is arranged inside the first rotating box 2, and the output shaft of the rotating motor is connected to the mounting seat 3. The mounting seat 3 can be rotated 360° around its axial direction through the first rotating box 2; an adjusting box 4 is installed in the middle of the top surface of the mounting seat 3, and a rotating plate 5 is arranged on the top surface of the adjusting box 4, and one end of the adjusting box 4 is movably hinged to one end of the rotating plate 5, and the rotating plate 5 can be controlled to rotate along the hinge axis through the adjusting box 4.

A first electric push rod 14 is provided on both sides between the mounting seat 3 and the rotating plate 5. The lower end of the first electric push rod 14 is movably hinged with the mounting seat 3, and the output shaft of the first electric push rod 14 is movably hinged with the bottom surface of the rotating plate 5; a second screw rod 15 is rotatably connected inside the adjustment box 4, and one end of the second screw rod 15 is connected to the output shaft of the first self-locking motor 16, and the first self-locking motor 16 is installed on the outside of the adjustment box 4; the outer side of the second screw 15 is threadedly connected to a hinge seat 17, and the upper end of the hinge seat 17 is movably hinged with a second electric push rod 18, and the output shaft of the second electric push rod 18 is movably hinged with the bottom surface of the rotating plate 5, and the second electric push rod 18 is used to push the rotating plate 5. The first support bracket 25 can be controlled to change from a horizontal state to a vertical state through the rotating plate 5.

The four ends of the top surface of the rotating plate 5 are all installed with columns 6; slide grooves are opened on the opposite sides of the four columns 6, and guide rods 7 are vertically fixedly connected in the slide grooves opened by the two columns 6 on one side, and the first screw rod 8 is vertically rotatably connected in the slide grooves opened by the two columns 6 on the other side. The upper end of the first screw rod 8 is connected with the output shaft of the first stepper motor 9, and the first stepper motor 9 is used to rotate the first screw rod 8; the first stepper motor 9 is installed on the top surface of the column 6; the lower ends of the guide rod 7 and the first screw rod 8 are both provided with a moving block 10, the moving block 10 on the guide rod 7 is slidably connected to the guide rod 7, and the moving block 10 on the first screw 8 is threadedly connected to the first screw 8; a connecting rod 11 is fixedly connected between the moving block 10 on the guide rod 7 on the same side and the moving block 10 on the first screw 8, a connecting plate 12 is fixedly connected between the two connecting rods 11, and a supporting plate 13 is horizontally fixedly connected between the two connecting plates 12, and a mounting block 19 and a second self-locking motor 22 are supported and installed on the supporting plate 13. The supporting plate 13 can be controlled to drive the mounting block 19 and the second self-locking motor 22 to move along the direction of the column 6 .

A mounting opening is provided on the top surface of the mounting block 19, and a driven gear 20 is provided in the mounting opening. A driving gear 21 is meshed and transmitted at the lower end of the driven gear 20. One end of the driving gear 21 is connected to the output shaft of the second self-locking motor 22. The driving gear 21 is rotated by the second self-locking motor 22, thereby driving the driven gear 20 to rotate; an internal threaded opening is provided in the middle part of the driven gear 20, and a third screw rod 23 is horizontally provided inside the driven gear 20. The third screw rod 23 is threadedly connected to the driven gear 20, and guide rods 24 are provided on both sides of the lower end of the third screw 23. The two guide rods 24 respectively pass through both sides of the mounting block 19, and both ends of the third screw 23 and the guide rod 24 are fixedly connected to the inner wall of the first support bracket 25; the third screw 23 is driven to rotate by the rotation of the driven gear 20, thereby driving the first support bracket 25 to move back and forth relative to the mounting block 19.

A second rotating box 26 is provided at one end of the first support bracket 25, and the second rotating box 26 is rotatably connected to the first support bracket 25; the second rotating box 26 is equivalent to a self-rotating motor and can rotate relative to the first support bracket 25. The second rotating box 26 is hinged with a second support bracket 27, and the second support bracket 27 can be rotated to the top of the first support bracket 25 along the hinge axis. The inner wall width of the second support bracket 27 is adapted to the outer wall width of the first support bracket 25, so that the second support bracket 27 can be buckled on the first support bracket 25. The second rotating box 26 is movably hinged with a third electric push rod 29 on both sides, and the output shaft of the third electric push rod 29 is movably hinged with the second support bracket 27. The second support bracket 27 can be unfolded by the action of the third electric push rod 29; the bottom surface of the second support bracket 27 is installed with a first support net 28, and the first support net 28 can reduce the overall weight of the second support bracket 27.

A third support bracket 30 is provided at the other end of the second support bracket 27, and the third support bracket 30 is used to extend the length of the second support bracket 27; the handrails on both sides of the third support bracket 30 are placed inside the handrails on both sides of the second support bracket 27, and a fourth screw 31 is provided inside the handrails on both sides of the second support bracket 27, and the third support bracket 30 is easily moved by the fourth screw 31; one end of the fourth screw 31 is connected to the output shaft of the second stepper motor 32, and the second stepper motor 32 is installed inside the handrail of the second support bracket 27, and the other end of the fourth screw 31 is connected to the output shaft of the third support bracket 3 0The handrails on both sides are threadedly connected, and a second supporting net 33 is installed on the bottom surface of the third supporting bracket 30; the other end of the third supporting bracket 30 is provided with mounting grooves on both sides, and a fixing rod 34 is vertically installed inside the mounting groove, and a spring 35 is sleeved on the outside of the fixing rod 34, and the fixing rod 34 prevents the spring 35 from falling off; the spring 35 is convenient for lifting the protective plate 36; the lower end of the spring 35 abuts against the bottom surface of the mounting groove, and the upper end of the spring 35 is provided with a protective plate 36, and the two ends of the protective plate 36 are placed in the mounting grooves on both sides, and the two ends of the protective plate 36 are sleeved on the outside of the fixing rod 34. A protective net 37 is installed between the protective plate 36 and the third supporting bracket 30, and the upper end of the protective net 37 is installed on the bottom surface of the protective plate 36, and the lower end of the protective net 37 is installed on the bottom surface of the third supporting bracket 30, and the protective net 37 prevents the staff from falling.

Working principle: A method for using a safety hanger device for bridge inspection and maintenance described in this embodiment includes the following steps:

Step 1: First, move the safety hanger device to the designated location on the bridge deck by a vehicle, and fix the base 1 on the bridge deck; then connect all electrical equipment with wires and power on, at this time, the third support bracket 30 shrinks and overlaps with the second support bracket 27, and the second support bracket 27 is buckled on the first support bracket 25. Start the first stepper motor 9, and rotate the first screw 8 through the first stepper motor 9. When the first screw 8 rotates, the two connecting plates 12 are controlled to rise, and then the support plate 13 is controlled to rise. When the support plate 13 rises, the mounting block 19, the driven gear 20, the driving gear 21, the second self-locking motor 22, the third screw 23, the guide rod 24 and the first support bracket 25 arranged thereon are controlled to rise to a position higher than the side railing of the bridge deck.

Step 2: Start the first rotating box 2, and control the upper mounting seat 3 to rotate through the first rotating box 2, thereby controlling the adjustment box 4 to rotate. At this time, the first support bracket 25 rotates from the horizontal direction to the longitudinal direction, that is, perpendicular to the length direction of the bridge deck; then start the first electric push rod 14, the second electric push rod 18 and the first self-locking motor 16, and control the second screw 15 to rotate through the first self-locking motor 16, and the second screw 15 and the articulated seat 17 are threadedly connected to control the movement of the articulated seat 17, and the second electric push rod 18 One end is movably hinged to the hinge seat 17, and the other end is movably hinged to the bottom surface of the rotating plate 5. When the first electric push rod 14, the second electric push rod 18 and the first self-locking motor 16 are started, the rotating plate 5 is movably hinged to the adjustment box 4, thereby controlling the first support bracket 25 to rotate from a horizontal state to a vertical state, and then extending the first support bracket 25, the second support bracket 27 and the third support bracket 30 out of the bridge. At this time, the first support bracket 25, the second support bracket 27 and the third support bracket 30 stand vertically on the outside of the bridge deck.

Step three, when the first support bracket 25, the second support bracket 27 and the third support bracket 30 are extended out of the bridge, the second self-locking motor 22 is turned on, and the driving gear 21 is rotated by the second self-locking motor 22, thereby driving the driven gear 20 to rotate; the driven gear 20 drives the third screw rod 23 to rotate, thereby causing the first support bracket 25 to drop to a specified height; the third electric push rod 29 is started, so that the second support bracket 27 and the third support bracket 30 are moved out from the upper end of the first support bracket 25, and are in a vertical state with the first support bracket 25. At this time, the spring 35 is changed from a compressed state to a relaxed state, thereby pushing the protective plate 36 upward, thereby pulling open the protective net 37, and then starting the second rotating box 26, and controlling the second support bracket 27 and the third support bracket 30 to rotate through the second rotating box 26, so that the second support bracket 27 and the third support bracket 30 are rotated to the lower end of the bridge, which is convenient for the staff to detect and repair the bottom surface of the bridge.

Step four, when the detection distance is not long enough, start the second stepper motor 32, rotate the fourth screw 31 through the second stepper motor 32, and then connect the fourth screw 31 to the handrail thread of the third supporting bracket 30. When the fourth screw 31 rotates, the third supporting bracket 30 is controlled to move outward, thereby increasing the detection distance, facilitating the complete detection of the bottom surface of the bridge and improving the detection efficiency.

The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims (9)

1. A safety hanger device for bridge inspection and maintenance, characterized in that it comprises a base (1); the top of the base (1) is connected to a horizontal rotation component, the top of the horizontal rotation component is connected to a flip and push-out component, the top of the flip and push-out component is connected to a lifting component, and the lifting component is connected to a first support frame (25); the first support frame (25) is horizontally rotated along the bridge deck under the action of the horizontal rotation component, the first support frame (25) is lifted and lowered in the height direction of the bridge under the action of the lifting component, and the first support frame (25) is moved to the side outside the bridge and is in a vertical state under the action of the flip and push-out component; The flip and ejection assembly comprises a first electric push rod (14) and an adjustment box (4); the two ends of the first electric push rod (14) are respectively hinged to the horizontal rotation assembly and the lifting assembly; one side of the bottom of the lifting assembly is hinged to one side of the adjustment box (4); a second screw rod (15) is rotatably connected inside the adjustment box (4), and one end of the second screw rod (15) is connected to the output shaft of the first self-locking motor (16); the outer side of the second screw rod (15) is threadedly connected to a hinge seat (17), the upper end of the hinge seat (17) is movably hinged to a second electric push rod (18), and the output shaft of the second electric push rod (18) is movably hinged to the bottom surface of the lifting assembly; One end of the first support bracket (25) is rotatably connected to a second rotating box (26); the second rotating box (26) is hingedly connected to a second support bracket (27); the second support bracket (27) is rotatably engaged with the first support bracket (25) along a hinge axis or is unfolded relative to the first support bracket (25); the second rotating box (26) is hingedly connected to a third electric push rod (29); an output shaft of the third electric push rod (29) is movably hingedly connected to the second support bracket (27). 2. A safety hanger device for bridge inspection and maintenance according to claim 1, characterized in that the horizontal rotation assembly comprises a first rotation box (2) and a mounting seat (3); the first rotation box (2) is installed on the top surface of the base (1), and the top surface of the first rotation box (2) is rotatably connected to the mounting seat (3); and the adjustment box (4) is connected to the top surface of the mounting seat (3). 3. A safety hanger device for bridge inspection and maintenance according to claim 1, characterized in that the lifting assembly comprises a rotating plate (5), a column (6) and a first screw (8); one end of the adjustment box (4) is movably hinged to one end of the rotating plate (5); the rotating plate (5) is rotatably connected to the first screw (8), and the first support bracket (25) is connected to the first screw (8). 4. A safety hanger device for bridge inspection and maintenance according to claim 3, characterized in that columns (6) are installed at the four ends of the top surface of the rotating plate (5); sliding grooves are opened on the opposite surfaces of the four columns (6), and guide rods (7) are vertically fixed in the sliding grooves opened by two columns (6) on one side, and first screw rods (8) are vertically rotatably connected in the sliding grooves opened by two columns (6) on the other side, and the upper end of the first screw rod (8) is connected to the output shaft of the first stepper motor (9). 5. A safety hanger device for bridge inspection and maintenance according to claim 4, characterized in that a moving block (10) is provided at the lower end of the guide rod (7) and the first screw rod (8), the moving block (10) on the guide rod (7) is slidably connected to the guide rod (7), and the moving block (10) on the first screw rod (8) is threadedly connected to the first screw rod (8); a connecting rod (11) is fixedly connected between the moving block (10) on the guide rod (7) on the same side and the moving block (10) on the first screw rod (8), a connecting plate (12) is fixedly connected between the two connecting rods (11), a supporting plate (13) is horizontally fixedly connected between the two connecting plates (12), and a second self-locking motor (22) is installed on the supporting plate (13); the second self-locking motor (22) is connected to the third screw rod (23) through a driving mechanism, and both ends of the third screw rod (23) are fixedly connected to the inner wall of the first supporting bracket (25). 6. A safety hanger device for bridge inspection and maintenance according to claim 5, characterized in that a mounting block (19) is installed on the supporting plate (13); the driving mechanism includes a driving gear (21) and a driven gear (20); a mounting opening is provided on the top surface of the mounting block (19), a driven gear (20) is provided in the mounting opening, the lower end of the driven gear (20) is meshed and driven with the driving gear (21), and one end of the driving gear (21) is connected to the output shaft of the second self-locking motor (22); an internal thread opening is provided in the middle of the driven gear (20), and the third screw (23) passes through the internal thread opening and is threadedly connected to the driven gear (20); guide rods (24) are provided on both sides of the lower end of the third screw (23), and the two guide rods (24) respectively pass through both sides of the mounting block (19), and both ends of the guide rods (24) are fixed to the inner wall of the first supporting bracket (25). 7. A safety hanger device for bridge inspection and maintenance according to claim 1, characterized in that a third support bracket (30) is provided at the other end of the second support bracket (27), and a fourth screw rod (31) is provided inside the handrails on both sides of the second support bracket (27), one end of the fourth screw rod (31) is connected to the output shaft of the second stepper motor (32), and the other end of the fourth screw rod (31) is threadedly connected to the handrails on both sides of the third support bracket (30). 8. A safety hanger device for bridge inspection and maintenance according to claim 7, characterized in that installation grooves are provided on both sides of one end of the third support bracket (30) away from the second support bracket (27), a fixing rod (34) is vertically installed inside the installation groove, a spring (35) is sleeved on the outside of the fixing rod (34), the lower end of the spring (35) abuts against the bottom surface of the installation groove, and the upper end of the spring (35) is connected to a protective plate (36), both ends of the protective plate (36) are placed in the installation grooves on both sides, and both ends of the protective plate (36) are sleeved on the outside of the fixing rod (34); a protective net (37) is connected between the protective plate (36) and the third support bracket (30). 9. A safety hanger device for bridge inspection and maintenance according to claim 7, characterized in that a first supporting net (28) is installed on the bottom surface of the second supporting bracket (27), and a second supporting net (33) is installed on the bottom surface of the third supporting bracket (30).