A variable height limited door frame

Abstract

The present invention discloses a variable height limit gantry, which belongs to the field of traffic safety protection, and particularly relates to a height limit device that can change the height to restrict the passage of super-high vehicles. It is mainly composed of a foundation, a column, a lifting part, a beam, a control unit, a monitoring center, and a mobile terminal. The column is arranged on the foundation, and the upper end of the column is the lifting part. The lifting part is composed of four guide columns arranged on the top of the column and a plurality of stacked folding arm lifts. The top of the column is a top plate to fix the guide columns to form a guide rail for the up and down movement of the beam. Guide plates are arranged on both ends of the beam, and there are four holes on the guide plates that slide with the four guide columns. The beam can move up and down along the guide columns; the lifting and lowering of the beam can be controlled by the operation panel of the control unit, and the monitoring center and the mobile terminal can remotely control the lifting and lowering of the beam, and adjust the height of the beam as needed to realize the variable height of the height limit gantry.

Description

Technical Field

[0001] The invention relates to the field of traffic safety protection, and in particular to a height limiting device capable of changing the height to restrict the passage of super-height vehicles. Background Art

[0002] Bridges and tunnels on urban roads and highways have certain height limits to ensure the safety of vehicle traffic. Generally, the height limit for urban roads is 4.5m, and the minimum clear height for expressways, first-class highways, and second-class highways is 5.0m. Due to some current conditions, when the clear height of the road under the bridge cannot meet the requirements of the specification, in order to protect the bridge structure from being hit by super-high vehicles, a height limit gantry needs to be set up. Generally, the height limit gantry is of a fixed height. However, there are also some special areas, such as: around schools and hospitals, and dedicated roads entering residential areas, where large vehicles are prohibited from passing, but large vehicles are still allowed to pass in special circumstances, such as firefighting, cargo transportation, and moving. There is also a special road that does not allow large vehicles to pass, such as: flood control roads beside rivers, which can be used as roads for small vehicles to ease the traffic pressure on urban roads. Large vehicles are not allowed to pass at ordinary times, and during the flood season, there will be requirements for large vehicles to transport flood control materials.

[0003] The variable height limit gantry can solve the above problem. Generally, the gantry height adjustment range is 1.0~2.5m. For example, the height limit of a small car is 3.0m. When it is adjusted to the height limit of a large vehicle at 4.5m, the gantry beam needs to be raised and lowered by 1.5m. Most of the variable height limit gantry in the prior art are height adjustment by lifting. The winch located above the beam is used to lift the beam. The upper part of the beam needs to increase the structural height by a large amount to install the winch, and the structure is complicated. There are also hydraulic lifting devices that change the height limit. Hydraulic cylinders are set in the columns at both ends of the gantry. The hydraulic cylinders are driven by a high-pressure oil pump to drive the hydraulic cylinders to lift and lower the beam. The hydraulic cylinders need a large stroke and a large-power oil pump. Under normal circumstances, the height limit gantry is in a low height limit state and is only adjusted when special characteristics are required. The gantry is driven by a winch and a hydraulic cylinder. The deadweight of the beam and the stroke of the power are reversible, that is, the deadweight of the beam can cause the power to move in the opposite direction. When the beam is in a high position, it relies on the brake device of the winch or the hydraulic cylinder oil circuit to close. If the beam is raised to a high position, it will not be lowered to a low position immediately after a large vehicle passes, but will stay in a high position for a period of time. Bolts are needed to fix the beam. When adjusting the height of the beam again, the fixing device needs to be loosened, which is cumbersome. The above-mentioned winch lifting or hydraulic cylinder lifting requires a relatively high-power power supply. In some special sections, such as the aforementioned flood control road beside the river, far away from the urban area, a special power line needs to be set up. Summary of the invention

[0004] The purpose of the present invention is to provide a variable height limited portal frame, which is mainly composed of a foundation, a column, a lifting part, a beam, a control unit, a monitoring center, and a mobile terminal. The column is arranged on the foundation, and the upper end of the column is the lifting part. The lifting part is composed of four guide columns arranged on the top of the column and a plurality of stacked folding arm lifts. The top of the column is a top plate to fix the guide columns to form a guide rail for the up and down movement of the beam. The two ends of the beam are provided with guide plates, and the holes on the guide plates are slidably matched with the guide columns, so that the beam can move up and down along the guide columns. The lifting and lowering of the beam can be controlled by the operation panel of the control unit, and the monitoring center and the mobile terminal can remotely control the lifting and lowering of the beam, and adjust the height of the beam as needed to realize the variable height of the limited portal frame.

[0005] The present invention is realized by the following technologies: a variable height limited gantry, mainly including a foundation 1, a column 2, a lifting part 3, a beam 4, a monitoring system 100, a control center 200, and a mobile terminal 300. The foundation 1, the column 2, the lifting part 3, and the beam 4 constitute the entity part of the gantry, and the monitoring system 100, the control center 200, and the mobile terminal 300 constitute the control part of the gantry. The foundation 1 is symmetrically arranged outside the road on both sides of the road along the transverse direction of the road, the column 2 is installed on the foundation 1, the upper end of the column 2 is the lifting part 3, and the lifting part 3 is composed of four guide columns 5 arranged on the top of the column 2 and a plurality of stacked arm lifts 6. The top of the guide column 5 is a top plate 7, and the top plate 7 fixes the four guide columns 5 to form a guide rail for the up and down movement of the beam 4. The two ends of the beam 4 are provided with guide plates 8, and the guide plates 8 have four holes that slide with the four guide columns 5. The beam 4 can move up and down along the guide columns 5. The lifting and lowering of the beam 4 can be controlled through the operation panel of the monitoring system 100, and the control center 200 and the mobile terminal 300 can remotely control the lifting and lowering of the beam 4, and adjust the height of the beam 4 as needed to achieve variable height of the height-limited gantry.

[0006] Furthermore, the folding arm lift 6 is hingedly provided with a relay plate 9 between the layers, and there are four holes on the relay plate 9 for sliding cooperation with the four guide columns 5. The folding arm lift 6 includes a folding arm 10, a screw 11, a nut plate 12, and a worm gear 13; the upper part of the nut plate 12 of the folding arm lift 6 of the uppermost layer adopts the folding arm 10 to hinge with the guide plate 8 at the lower part of the cross beam 4, and the lower part of the nut plate 12 adopts the folding arm 10 to hinge with the relay plate 9; the lower part of the nut plate 12 of the folding arm lift 6 of the lowermost layer adopts the folding arm 10 to hinge with the top of the column 2, and the upper part adopts the folding arm 10 to hinge with the relay plate 9.

[0007] Furthermore, the plurality of folding arm lifts 6 share a power source, and the motor 14 outputs the rotational power through the worm 15 after deceleration, and the worm 15 is installed between the top of the column 2 and the top plate 7 by a bearing. There are two lead screws 11, and the worm wheel 13 is arranged in the middle of the lead screw 11. The worm wheel 13 is coaxial with the lead screw 11. The worm wheel 13 on each lead screw 11 is arranged on both sides of the worm 15. The teeth of the worm wheel 13 are meshed with the threads of the worm 15. When the worm 15 rotates, the two worm wheels 13 are driven to rotate. The two worm wheels 13 rotate in opposite directions. The threads of the same lead screw 11 at both ends of the worm wheel 13 are opposite. The threads of the two lead screws 11 on the same side of the worm wheel 13 are opposite. When the motor 14 rotates forward, the worm 15 drives The two worm gears 13 rotate, and the mutually opposite threads drive the nut plate 12 to move inward, driving the folding arm 10 to extend, and multiple folding arm lifts 6 are connected through the relay plate 9 to push the crossbeam 4 upward, so that the crossbeam 4 moves to the high limit H1; when the motor 14 reverses, the worm 15 drives the two worm gears 13 to rotate, and the mutually opposite threads drive the nut plate 12 to move outward, driving the folding arm 10 to fold, and multiple folding arm lifts 6 are connected through the relay plate 9 to pull the crossbeam 4 downward, so that the crossbeam 4 moves to the low limit H2.

[0008] Furthermore, a travel detector 16 is installed at the top plate 7 on the upper part of the guide column 5, one is arranged on each side of the door frame, and the travel detector 16 adopts an ultrasonic displacement sensor. The ultrasonic wave emitted by the sensor is reflected by the guide plate 8 on the upper part of the beam 4, and then received by the travel detector 16. The detected ultrasonic signal is transmitted to the monitoring system 100. The monitoring system 100 controls the operation of the motor 14 to control the beam 4 to stop at the high limit H1 or the low limit H2. The monitoring system 100 can set a custom stop height of the beam 4. When the travel detector 16 detects that the beam 4 reaches the custom height, the monitoring system 100 controls the beam 4 to stop.

[0009] Furthermore, the monitoring system 100 controls the operation of the motors 14 on both sides of the gantry respectively. The motors 14 are DC adjustable speed motors. When the gantry beam 4 moves upward or downward, the travel detectors 16 on both sides detect the position of the beam 4. The monitoring system 100 adjusts the speed of the motors 14 on one side or both sides to ensure that the moving positions of both sides of the beam 4 are synchronized.

[0010] A monitoring camera 17 is provided on the top of the top plate 7 for observing passing vehicles when remotely controlling the lifting and lowering of the gantry.

[0011] An electronic height limit sign 18 and an electronic display screen 19 are provided on two sides of the crossbeam 4. The electronic height limit sign 18 displays the height limit in real time according to the height detected by the travel detector 16, and the electronic display screen 19 dynamically displays safety prompts.

[0012] Furthermore, a solar cell panel 20 is provided on the top surface of the crossbeam 4 .

[0013] The present invention is a lifting type variable height limit door frame. Compared with the prior art, the present invention adopts motor reduction to drive the worm and worm wheel, and drives the lead screw to drive the folding arm lift. The beneficial effects are: the multi-stage folding arm lift is stacked, and the lifting height of each folding arm lift is superimposed, and a shorter lead screw stroke can be used to obtain a larger lifting height. The worm and worm wheel drive the lead screw drive, which has a reverse non-reverse self-locking effect, and the crossbeam does not need to be fixed; the motor has a larger transmission ratio through the worm and worm wheel transmission, and the required power is small. Solar energy is used to power the DC motor, and it can be used on roads far away from urban areas without power supply, and it has good adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the high limit front elevation drawing;

[0015] Figure 2 This is the low limit front elevation drawing;

[0016] Figure 3 It is the high limit side elevation;

[0017] Figure 4 It is the low limit side elevation;

[0018] Figure 5 This is the side elevation drawing of the high limit lifting part;

[0019] Figure 6 This is the front elevation drawing of the high limit lifting part;

[0020] Figure 7 This is the side elevation drawing of the low limit lifting part;

[0021] Figure 8 This is the front elevation drawing of the low limit lifting part;

[0022] Fig. 9 Horizontal cross-section of the lifting part;

[0023] Fig.10 Electrical control schematic diagram of the monitoring system.

[0024] In the figure: 1-foundation, 2-column, 3-lifting part, 4-crossbeam, 5-guide column, 6-folding arm lift, 7-top plate, 8-guide plate, 9-relay plate, 10-folding arm, 11 lead screw, 12-nut plate, 13-worm gear, 14-motor, 15-worm, 16-travel detector, 17-surveillance camera, 18-electronic height limit sign, 19-electronic display screen, 20-solar panel, 21-protective cover. DETAILED DESCRIPTION

[0025] In order for those skilled in the art to better understand the present invention, Figures 1 to 10To further illustrate the present invention, the directions or positional relationships indicated by "upper", "lower", "inner", "outer" and the like in the present description are based on the directions or positional relationships shown in the drawings, or are directions or positional relationships commonly understood by those skilled in the art, and are only simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the structure referred to must have a specific direction, be constructed and operated in a specific direction. The structural proportional relationships shown in the drawings are only for illustration, and do not indicate or imply the necessary proportional relationships of the structures referred to, and the contents mentioned in the embodiments are not limitations of the present invention.

[0026] The present invention is a lifting variable height limit gantry. The lifting of the beam 4 can be controlled by the operation panel of the monitoring system 100, the lifting of the beam 4 can be remotely controlled by the control center 200, and the lifting of the beam 4 can be controlled by the mobile terminal 300 (mobile phone APP). In addition to the determined high limit and low limit, the height limit of the beam 4 can also be customized according to needs. The variable height limit gantry mainly includes a foundation 1, a column 2, a lifting part 3, a beam 4, a monitoring system 100, a control center 200, and a mobile terminal 300. The foundation 1, the column 2, the lifting part 3, and the beam 4 constitute the physical part of the gantry, and the monitoring system 100, the control center 200, and the mobile terminal 300 constitute the control part of the gantry. The foundation 1 is symmetrically arranged outside the road on both sides of the road along the transverse direction of the road. The transverse elevation view of the height limit gantry road (i.e., the front elevation view of the height limit gantry) is shown in FIG. Figure 1 , Figure 2 . Figure 1 This is a high-limit front elevation view, which can accommodate large vehicles. Figure 2 This is a low-limit front elevation view, only small vehicles are allowed to pass. Figure 1 , Figure 2 The medium height limit signs of 4.5m and 3.0m are for reference only and are not limitations of the present invention. Figure 3 This is a side elevation view of the high limit position of the height-limited gantry. The crossbeam 4 is located at the high limit position H1, and large vehicles can pass through; Figure 4 This is a side elevation view of the low limit position of the height-limited gantry. The crossbeam 4 is located at the low limit position H2, and only small vehicles are allowed to pass.

[0027] The upper end of the column 2 is a lifting part 3, which is the key technical feature of the present invention that distinguishes it from the prior art. The lifting part 3 is composed of four guide columns 5 arranged on the top of the column 2 and a plurality of stacked arm lifts 6. The top of the guide column 5 is a top plate 7, which fixes the four guide columns 5 to form a guide rail for the up and down movement of the crossbeam 4. The two ends of the crossbeam 4 are provided with guide plates 8. There are four holes on the guide plate 8 that slide with the four guide columns 5. The crossbeam 4 can move up and down along the guide columns 5. The so-called sliding fit means that it can move flexibly without being loose. There is a gap of 1 to 2 mm between the four holes on the guide plate 8 and the guide column 5, and lubricating oil is applied. If the gap is too small, it is easy to get stuck, and if the gap is too large, it is easy to get loose.

[0028] The folding arm lift 6 is similar to the hand-cranked jack equipped with a car. Four folding arms form a parallelogram. Hand-cranked screws are set at the two horizontal corners of the parallelogram. The rotation of the screw drives the folding arm to fold or stretch, and the other two vertical corners rise or fall accordingly. The folding arm lift 6 of the present invention includes a folding arm 10, a lead screw 11, a nut plate 12, and a worm gear 13. Several folding arm lifts 6 are stacked, and the number of layers can be determined according to the lifting height of a folding arm lift 6 and the total lifting height required by the lifting part 3. It is appropriate for the folding arm lift 6 to have 2 to 5 layers, and the lifting height of each layer is preferably 40 to 50 cm. The upper end of the lifting part 3 is connected to the crossbeam 4, and the lower end is connected to the column 2. The folding arm lift 6 is hinged with a relay plate 9 between the layers. There are four holes on the relay plate 9 that slide with the four guide columns 5. The clearance requirements between the holes of the relay plate 9 and the guide columns 5 are the same as those of the guide plate 8. The relay plate 9 can slide on the guide column 5 as the folding arm lift 6 rises and falls. The upper part of the nut plate 12 of the uppermost folding arm lift 6 is hinged to the guide plate 8 at the lower part of the cross beam 4 by the folding arm 10, and the lower part of the nut plate 12 is hinged to the relay plate 9 by the folding arm 10; the lower part of the nut plate 12 of the lowermost folding arm lift 6 is hinged to the top of the column 2 by the folding arm 10, and the upper part is hinged to the relay plate 9 by the folding arm 10. When the folding arm 10 is fully unfolded, the cross beam 4 is at the high limit position. Figure 5 Side elevation drawing of the high limit lifting unit, Figure 6 The front elevation of the high limit lifting part; when the folding arm 10 is fully folded, the crossbeam 4 is at the low limit, see Figure 7 Side elevation drawing of the low limit lifting part, Figure 8 Large-scale drawing of the front elevation of the low-limit lifting section. Figure 5 , Figure 6 , Figure 7 , Figure 8 The three-layer folding arm lift 6 is only an embodiment and is not a limitation of the present invention. The folding arm 10 described above is completely folded, and the nut plate 12 moves to the end of the lead screw 11. The folding arm 10 cannot be folded any further. The folding arm 10 must maintain a certain inclination angle with the horizontal, preferably 10°~30°, otherwise the lead screw 11 needs a lot of force to move the nut plate 12. If the folding arm 10 is in a horizontal state, the lead screw 11 cannot move the nut plate 12. The lead screw 11 of each folding arm lift 6 drives the nut plate 12 to move in the same stroke. Multiple folding arm lifts 6 are stacked and connected through the relay plate 9, and the lifting part 3 can obtain a larger lifting height.

[0029] Several folding arm lifts 6 in the lifting part 3 share a power source. The motor 14 outputs the rotational power through the worm 15 after deceleration. The worm 15 is installed between the top of the column 2 and the top plate 7 with a bearing. The rotational power output by the motor 14 is transmitted to the worm wheel 13 through the worm 15. The worm wheel 13 rotates coaxially with the lead screw 11. The lead screw 11 converts the rotational motion into linear motion through the nut plate 12. The nut plate 12 drives the folding arm 10 to extend or fold. The worm transmission has a larger transmission ratio than that of an ordinary gear transmission. When the helix angle of the worm 15 is very small, the worm 15 can only drive the worm wheel 13 to rotate, while the worm wheel 13 cannot drive the worm 15 to rotate. It has self-locking properties. The lead screw transmission also has self-locking properties. The rotation of the lead screw 11 drives the nut plate 12 to move linearly, while the linear motion of the nut plate 12 cannot drive the lead screw 11 to rotate. In this application, the weight of the crossbeam 4 can be prevented from causing reverse operation. The worm wheel 13 of the present invention is arranged in the middle of the lead screw 11. The worm wheel 13 is coaxial with the lead screw 11. See Figure 5 , Figure 7 There are two lead screws 11, and the worm wheel 13 on each lead screw 11 is arranged on both sides of the worm 15, and the teeth of the worm wheel 13 are engaged with the thread of the worm 15, see Figure 6 , Figure 8 When the worm 15 rotates, it drives the two worm wheels 13 to rotate. The two worm wheels 13 rotate in opposite directions. The threads of the same lead screw 11 at both ends of the worm wheel 13 are opposite. The threads of the two lead screws 11 on the same side of the worm wheel 13 are opposite. When the motor 14 rotates forward, the worm 15 drives the two worm wheels 13 to rotate. The threads in opposite directions drive the nut plate 12 to move inward, driving the folding arm 10 to extend. Fig. 9 The dotted arrow in the figure indicates the direction of turning and moving. Multiple folding arm lifts 6 are connected through relay plates 9 to push the crossbeam 4 upward, so that the crossbeam 4 moves to the high limit H1. Figure 5 , Figure 6 When the motor 14 reverses, the worm 15 drives the two worm wheels 13 to rotate, and the mutually opposite threads drive the nut plate 12 to move outward, driving the folding arm 10 to fold, and multiple folding arm lifts 6 are connected through the relay plate 9 to pull down the beam 4, so that the beam 4 moves to the lower limit H2, see 7, Figure 8 The folding arm lift 6 is raised or lowered, and the worm gear 13 moves on the worm 15 accordingly. Two worm gears 13 are arranged on both sides of the worm 15, sandwiching the worm 15 in the middle to form a moving support for the worm 15. The two worm gears 13 drive the two lead screws 11 to push and pull the nut plates 12, and the two sides of the nut plates 12 drive the folding arm 10 to extend or fold more smoothly.

[0030] The present invention adopts electronic control of the stop position of the beam 4. Compared with the traditional travel switch limit, the stop position of the beam 4 can be arbitrarily set between the high limit and the low limit. For example, the high limit H1 of the height-limited gantry is 4.5m, and the low limit H2 is 3.0m. The travel switch is used to control the beam 4 to stop only at the high limit and the low limit. If it stops at a certain height in the middle, it is necessary to install a travel switch at this position. A travel detector 16 is installed at the top plate 7 on the upper part of the guide column 5 of the present invention, and one is arranged on each side of the gantry. The travel detector 16 adopts an ultrasonic displacement sensor. The ultrasonic wave emitted by the sensor is reflected by the guide plate 8 on the upper part of the beam 4, and then received by the travel detector 16. The detected ultrasonic signal is transmitted to the monitoring system 100. The monitoring system 100 controls the operation of the motor 14 to control the beam 4 to stop at the high limit H1 or the low limit H2. The monitoring system 100 can arbitrarily set the custom stop height of the beam 4. When the travel detector 16 detects that the beam 4 reaches the custom height, the monitoring system 100 controls the beam 4 to stop. The monitoring system 100 controls the operation of the motors 14 on both sides of the gantry respectively. The motors 14 are DC adjustable speed motors. When the gantry beam 4 moves upward or downward, the travel detectors 16 on both sides detect the position of the beam 4. The monitoring system 100 adjusts the rotation speed of the motors 14 on one side or both sides to ensure that the moving positions of both sides of the beam 4 are synchronized.

[0031] The present invention can adjust the height of the gantry through remote control. For example, if a large vehicle carrying goods needs to pass through, it can contact the control center 200 by phone. After confirming that it is allowed to pass, the control center 200 can remotely control the gantry crossbeam 4 to rise. When the vehicle passes and then drops to the lower limit, the control center 200 must observe whether there are large vehicles approaching to avoid collision accidents when the crossbeam 4 drops. Large vehicles that often pass through can operate the gantry to rise through the authorized mobile phone APP mobile terminal 300. When it falls back to the low position after passing, it can be viewed on site, or the on-site conditions can be viewed on the mobile phone APP. A monitoring camera 17 is provided on the top of the top plate 7 of the present application, which is used for the control center 200 and the mobile terminal 300 to observe passing vehicles when remotely controlling the lifting and lowering of the gantry.

[0032] The two sides of the crossbeam 4 of the present invention are provided with an electronic height limit sign 18 and an electronic display screen 19. The electronic height limit sign 18 displays the height limit in real time according to the height detected by the travel detector 16, and the electronic display screen 19 dynamically displays safety tips. The electronic height limit sign 18 and the electronic display screen 19 adopt P10 dual-primary color LED outdoor electronic screens with automatic brightness adjustment function.

[0033] The present invention adopts solar energy for power supply, which is convenient for use on roads far away from power sources. A solar cell panel 20 is arranged on the top surface of the crossbeam 4 , and a storage battery is arranged in the column 2 .

[0034] The present invention is implemented by processing and manufacturing the gantry in the factory and installing it on site. The minimum clear distance between the gantry column 2 and the road curb shall not be less than 500mm. The column 2 is installed on the foundation 1. The gantry needs to resist a large impact force. The foundation 1 is cast with reinforced concrete. The size of the foundation 1 along the direction of vehicle travel is large. Figure 3 , Figure 4 , steel bars are set in the concrete of foundation 1, and the bearing capacity of the foundation needs to be verified. The height-limited portal frame needs to be verified for anti-overturning and anti-slip under the combined action of vehicle impact and wind load. The lower limit height H2 of the height-limited portal frame can be determined according to the actual height of small vehicles passing through. It is advisable to leave a safety distance of 500mm higher than the actual vehicle height, and at least 200mm higher. The upper limit height H1 should meet the standard requirements of 4.5m. Column 2 is welded with steel plates, and beam 4 is welded with steel pipes to form a truss, which has a light weight and high rigidity. All steel parts need to be hot-dip galvanized.

[0035] Each component of the lifting part 3 is manufactured by machining, and the worm wheel 13 and the worm 15 are customized. In the worm gear transmission device, the worm 15 rotates one circle, and the worm wheel 13 rotates one tooth. The number of teeth of the worm wheel 13 is preferably 10 to 20, and the transmission ratio is 1:10 to 20. The screw 11 is also customized and a ball screw is used. The matching nut has a transmission device composed of multiple balls, which runs smoothly and stably. The matching ball nut is fixed on the nut plate 12. The folding arm 10 is made of steel, and brass sleeves are set at both ends of the folding arm 10. The hinged hinge shaft is made of stainless steel. The hinge shaft and the sleeve are matched with each other in a gapless sliding manner, and the sleeve is provided with a lubricating oil filling hole. A protective cover 21 is arranged on the outside of the lifting part 3, see Figure 1 to Figure 8 The dotted outer frame of the middle lifting part 3 and the protective cover 21 of the vertically movable part of the crossbeam 4 are opened, and a roller shutter is provided at the opening.

[0036] The motor 14 uses a 24-48V, 300-500W DC adjustable speed motor. The sensor of the travel detector 16 uses a finished component. The maximum detection distance of the currently available ultrasonic displacement sensor is 5-6m, and the accuracy reaches the millimeter level. The detection distance can be slightly larger than the gantry lifting height.

[0037] The electrical control schematic diagram of the monitoring system is shown in Fig.10 , the detection unit, camera unit, display unit, computing unit, control unit, and communication unit are integrated on a PCB board ( Fig.10 The device box is provided with a control panel for local operation of the height-limiting gantry. A locked door is provided at the position of the control panel on the column 2.

[0038] Embodiment, the variable height limit gantry has a high limit of H1=4.5m, a low limit of H2=3.0, a crossbeam height change of 1.5m, and a height change of the lifting part 3 of 1.5m or more. The folding arm lift 6 has three layers, and the dimensions of each part of the folding arm lift 6 are accurate to mm, and the dimensions are measured in mm. The variable height of a folding arm lift 6 should be greater than or equal to 500mm, the length of the folding arm 10 is 400mm (the center distance of the hinge axis, the same below), the inclination angle of the folding arm 10 to the horizontal is 15° after being folded, the vertical height of a folding arm 10 is sin15°×400=103.527mm, the upper and lower hinge axis distance of the nut plate 12 is 150mm, the height of the folding arm lift 6 in the fully folded state is 2×103.257+150=357.055mm, the hinge axes of the relay plate 9 connecting the upper and lower folding arm lifts 6 are coaxial and do not occupy height, the height of the three-layer folding arm lift 6 in the folded state is 357.055×3=1071.165mm, rounded to 1071mm. The folding arm lift 6 is fully unfolded, and the folding arm 10 is upright. The height of one folding arm lift 6 is 2×400+150=950mm. The height of the three-layer folding arm lift 6 in the unfolded state is 950×3=2850mm. The change height of the three-layer folding arm lift 6 is 2850-1071=1779mm>1500mm, which meets the requirements. The upper and lower travel margins of the beam 4 are left, and the height of the top of the column 2 from the road surface is 1800mm. The height of the column 2 is calculated and determined based on the height difference between the top surface of the foundation 1 and the road surface. The lower limit height of the bottom of the beam 4 from the road surface is 1800+1071=2871mm (2.871m), and the upper limit height from the road surface is 2871+1799=4650mm (4.65m). The monitoring system 100 uses the travel detector 16 to control the upper limit H1 to 4.5m and the lower limit H2 to 3.0m. A travel switch is provided 20 to 50 mm above the upper limit H1 and 20 to 50 mm below the lower limit H2, and is used to control the motor 14 by means of a mechanical limit switch when a travel detector 16 fails.

[0039] The description and drawings of this application are only a specific implementation method and are not restrictive. Under the guidance of this application, technicians in this field can make many forms without departing from the scope of protection of the purpose of this application and the claims, all of which are within the scope of protection of this application.

Claims

1. A variable height limit gantry, mainly comprising a foundation (1), a column (2), a lifting part (3), a crossbeam (4), a monitoring system (100), a control center (200), and a mobile terminal (300); the foundation (1), the column (2), the lifting part (3), and the crossbeam (4) constitute the entity part of the gantry, and the monitoring system (100), the control center (200), and the mobile terminal (300) constitute the control part of the gantry; the foundation (1) is symmetrically arranged outside the road on both sides of the road along the transverse direction of the road, the column (2) is installed on the foundation (1), and the upper end of the column (2) is the lifting part (3), and the characteristics are: The lifting part (3) is composed of four guide pillars (5) arranged on the top of the column (2) and a plurality of stacked folding arm lifts (6). The folding arm lifts (6) are hingedly provided with relay plates (9) between the layers. The relay plates (9) have four holes that are slidably matched with the four guide pillars (5). The folding arm lifts (6) include folding arms (10), lead screws (11), nut plates (12), and worm gears (13). The upper part of the nut plate (12) of the uppermost folding arm lift (6) is hingedly connected to the guide plate (8) at the lower part of the crossbeam (4) by the folding arm (10). The nut plate (12) is hingedly connected to the guide plate (8) at the lower part of the crossbeam (4). 2) The lower part adopts a folding arm (10) and a relay plate (9) to be hinged; the lower part of the nut plate (12) of the folding arm lift (6) of the lowest layer adopts a folding arm (10) and a top of the column (2) to be hinged, and the upper part adopts a folding arm (10) and a relay plate (9) to be hinged; the top of the guide column (5) is a top plate (7), and the top plate (7) fixes the four guide columns (5) to form a guide rail for the vertical movement of the crossbeam (4), and guide plates (8) are arranged at the upper and lower ends of the two ends of the crossbeam (4), and the guide plates (8) have four holes that are slidably matched with the four guide columns (5), so that the crossbeam (4) can move up and down along the guide columns (5); The plurality of folding arm lifts (6) share a common power source, the motor (14) outputs rotational power through the worm (15) after deceleration, the worm (15) being installed between the top of the column (2) and the top plate (7) by means of a bearing; the plurality of lead screws (11) are two, the worm wheel (13) is arranged in the middle of the lead screw (11), the worm wheel (13) is coaxial with the lead screw (11), the worm wheel (13) on each lead screw (11) is arranged on both sides of the worm (15), the teeth of the worm wheel (13) are meshed with the threads of the worm (15), when the worm (15) rotates, the two worm wheels (13) are driven to rotate, the two worm wheels (13) rotate in opposite directions, the threads of the same lead screw (11) at both ends of the worm wheel (13) are opposite, The two lead screws (11) have opposite threads on the same side of the worm wheel (13). When the motor (14) rotates forward, the worm (15) drives the two worm wheels (13) to rotate, and the threads in opposite directions drive the nut plate (12) to move inward, driving the folding arm (10) to extend. The multiple folding arm lifts (6) are connected through the relay plate (9) to push the cross beam (4) upward, so that the cross beam (4) moves to the upper limit H1. When the motor (14) rotates reversely, the worm (15) drives the two worm wheels (13) to rotate, and the threads in opposite directions drive the nut plate (12) to move outward, driving the folding arm (10) to fold. The multiple folding arm lifts (6) are connected through the relay plate (9) to pull the cross beam (4) downward, so that the cross beam (4) moves to the lower limit H2. A travel detector (16) is installed at the top plate (7) on the upper part of the guide column (5), and one is arranged on each side of the door frame. The travel detector (16) adopts an ultrasonic displacement sensor. The ultrasonic wave emitted by the sensor is reflected by the guide plate (8) on the upper part of the beam (4), and then received by the travel detector (16). The detected ultrasonic signal is transmitted to the monitoring system (100). The monitoring system (100) controls the operation of the motor (14) to control the beam (4) to stop at the high limit H1 or the low limit H2. The monitoring system (100) sets a custom beam ( 4) Stop height, when the travel detector (16) detects that the beam (4) reaches the custom height, the monitoring system (100) controls the beam (4) to stop; the monitoring system (100) controls the operation of the motors (14) on both sides of the gantry respectively, the motors (14) adopt a DC adjustable speed motor, when the gantry beam (4) moves upward or downward, the travel detectors (16) on both sides detect the position of the beam (4), and the monitoring system (100) adjusts the speed of the motor (14) on one side or both sides to ensure that the movement positions of both sides of the beam (4) are synchronized; The lifting and lowering of the crossbeam (4) can be controlled through the operation panel of the monitoring system (100); the control center (200) and the mobile terminal (300) can remotely control the lifting and lowering of the crossbeam (4), and adjust the height of the crossbeam (4) as required, thereby achieving a variable height of the height-limited gantry.

2. The variable height limit mast according to claim 1 is characterized in that: A monitoring camera (17) is provided on the top of the top plate (7) for observing passing vehicles when remotely controlling the lifting and lowering of the gantry.

3. The variable height limit mast according to claim 1 is characterized in that: An electronic height limit sign (18) and an electronic display screen (19) are provided on two side surfaces of the crossbeam (4); the electronic height limit sign (18) displays the height limit in real time according to the height detected by the travel detector (16), and the electronic display screen (19) dynamically displays safety prompts.

4. The variable height limit mast according to claim 1 is characterized in that: A solar cell panel (20) is provided on the top surface of the crossbeam (4).

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