A two-stage telescopic boarding ladder and a boarding vehicle

Abstract

The present invention discloses a two-stage telescopic boarding ladder and a boarding vehicle. The boarding ladder includes a fixed ladder, a main telescopic ladder, and an intermediate ladder located between the fixed ladder and the main telescopic ladder. Both the intermediate ladder and the main telescopic ladder are telescopically connected to the fixed ladder through corresponding guide rail pair structures, and the intermediate ladder and the main telescopic ladder have a dragging structure for dragging the intermediate ladder to extend synchronously after the main telescopic ladder extends a set distance. The intermediate ladder is located inside the ladder frame of the fixed ladder, and the intermediate ladder guide rail pair between the intermediate ladder and the fixed ladder is located between the opposite side walls of the fixed ladder frame and the intermediate ladder frame. The boarding vehicle has the aforementioned boarding ladder. The beneficial effects of the present invention are that the boarding ladder has a larger height adjustment range, can adapt to more passenger aircraft models, can reduce airport operation costs, and has a stable structure, a compact layout, reliable functions, and a long service life. The boarding vehicle has the same structural characteristics and excellent properties as the boarding ladder.

Description

Technical Field

[0001] The present invention relates to an airliner boarding ladder, in particular to a two-stage telescopic boarding ladder and a mobile ladder for boarding an aircraft. Background Art

[0002] As an airport facility, the boarding ladder is mainly used in situations where there is no boarding bridge available, such as for aircraft performing special tasks, VIP special aircraft, or when the airport facilities are imperfect, the boarding bridge has not been built or the number of boarding bridge positions is small. The existing boarding ladder is only a single-stage telescopic structure, including a fixed ladder and a telescopic ladder. Fixed steps are provided on both the fixed ladder and the telescopic ladder. A boarding platform is provided at the distal end of the telescopic ladder. When the telescopic ladder is fully retracted, the minimum boarding height can be formed, and when the telescopic ladder is fully extended, the maximum boarding height is formed. The two boarding heights constitute the boarding height adjustment range of the boarding ladder. Obviously, the length of the fixed ladder determines the minimum boarding height, and the length of the telescopic ladder determines the maximum boarding height.

[0003] To ensure the safety of aircraft passengers getting on and off the boarding ladder, the industry has clear specifications for the passage width, guardrail height, slope, step height, step depth, and levelness of the steps of the boarding ladder. To meet the requirements of structural stability, long service life, and safety guarantee, the length of the telescopic ladder and the length of the fixed ladder can only be set within a certain proportional range, and their lengths must be selected according to an integer number of steps. To facilitate the movement of the boarding ladder within the airport, the boarding ladder is usually mounted on a vehicle chassis and is arranged obliquely with the front end higher than the rear end as a whole. The fixed ladder extends obliquely upward from the rear end of the vehicle chassis, and the telescopic ladder is located below the fixed ladder and telescopic longitudinally along the fixed ladder. When the mobile ladder for boarding an aircraft is traveling within the airport, the telescopic ladder needs to be retracted and the front end lowered to meet the vehicle height limit requirements of the airport. Since after the telescopic ladder is retracted in the height direction, the end of the telescopic ladder is located within the acute angle below the fixed ladder. Restricted by the space of the bearing platform and the acute angle part below the fixed ladder, the structure of the steps fixed on the telescopic ladder, and factors such as the lowest boarding height, the number of steps of the telescopic ladder must be less than that of the fixed ladder. As a result, the boarding height adjustment range of the existing single-stage telescopic boarding ladder has great limitations and is usually only suitable for some airliners of existing specifications.

[0004] For large airports, due to the large throughput, variety of aircraft types, and large variation range of boarding heights, usually two or more boarding ladders with different adjustment ranges need to be used to meet the requirements of a large difference in boarding heights, which will inevitably lead to an increase in airport operating costs. Especially when dealing with new airliners whose boarding heights exceed the inherent boarding height adjustment range, only a new boarding ladder can be customized, which will inevitably lead to a decrease in the utilization rate of the existing boarding ladder and further increase the operating costs. Therefore, it is necessary to develop a mobile ladder for boarding an aircraft with a two-stage telescopic ladder. Summary of the Invention

[0005] The first object of the present invention is to provide a two-stage telescopic boarding ladder in view of the deficiency that the existing boarding ladders are limited in adapting to the types of passenger aircraft. The boarding ladder is composed of two-stage telescopic ladders to form a three-stage telescopic structure, so as to increase the adjustment range of the extended height, expand the applicable aircraft types, and form a telescopic connection structure between the two-stage telescopic ladders and the fixed ladder to ensure the stability and safety in use in the extended state. The second object of the present invention is to provide a boarding vehicle with the aforementioned two-stage telescopic boarding ladder.

[0006] To achieve the first object, the present invention adopts the following technical solutions.

[0007] A two-stage telescopic boarding ladder includes a fixed ladder and a main telescopic ladder. A first hinge part is provided at the front end of the fixed ladder, and a lifting machine is hinged to the first hinge part. A second hinge part is provided at the rear end of the fixed ladder; the main telescopic ladder is connected with a main ladder driving oil cylinder; an intermediate ladder is further included between the fixed ladder and the main telescopic ladder. Both the intermediate ladder and the main telescopic ladder form a telescopic connection with the fixed ladder through corresponding guide rail pair structures, and there is a dragging structure for dragging the intermediate ladder to extend synchronously after the main telescopic ladder extends a set distance. The intermediate ladder is located inside the ladder frame of the fixed ladder, and the intermediate ladder guide rail pair between the intermediate ladder and the fixed ladder is located between the opposite side walls of the fixed ladder frame and the intermediate ladder frame.

[0008] The present invention adopting the aforementioned technical solutions forms a three-stage telescopic structure boarding ladder with two-stage telescopic ladders by the main telescopic ladder and the intermediate ladder, and the main telescopic ladder is driven to extend and retract by the main ladder driving oil cylinder. When used for a boarding vehicle, it is hinged to the tail end of the vehicle chassis through the second hinge part at the rear end of the fixed ladder, the lifting machine supports the front end of the fixed ladder, and the lifting machine adjusts the pitching angle, and the main ladder driving oil cylinder adjusts the total length of the boarding ladder. On the premise of meeting the same retracted height, it ensures that its passability in the airport is not reduced, and a wider adjustment range of the boarding height can be obtained to adapt to more types of passenger aircraft, reducing the airport operation cost. At the same time, through the structure that both two-stage telescopic ladders form a telescopic connection with the fixed ladder, the stability and safety in use in the extended state are ensured. Moreover, the intermediate ladder is dragged and extended by the main telescopic ladder, and only a driving device for driving the main telescopic ladder to extend and retract needs to be set, simplifying the structure; the intermediate ladder is arranged inside the ladder frame of the fixed ladder, which can effectively compact the structure layout, save space, reduce the overall volume of the machine, and provide guarantee for the passability in the airport.

[0009] Preferably, the front end of the ladder frame of the fixed ladder is fixedly connected with a support frame, the support frame extends from the side of the ladder frame of the fixed ladder to the back, and there is a space between the support frame and the back of the fixed ladder for the main telescopic ladder to move telescopically; the fixed ladder and the intermediate ladder are both located in the front of the main telescopic ladder; and the upper and lower parts of the support frame are triangular, and the first hinged part is arranged through the support frame and is located at a downward angle of the triangle. The support frame forms a connection relationship with the lift and the main telescopic ladder, and the support frame is used to expand the structural size of the connection part to ensure the reliability of the connection; the intermediate ladder is arranged in the front of the main telescopic ladder, so that the towing structure can be arranged in a hidden manner.

[0010] Further preferably, the guide rail pair between the fixed ladder and the main telescopic ladder is composed of two sub-guide rail pairs; the two sub-guide rail pairs are respectively composed of a load-bearing guide rail pair and a yaw control guide rail pair; and the load-bearing guide rail pair and the yaw control guide rail pair both adopt a rolling guide structure. By decomposing the two functions of the guide rail pair structure into two groups of guide rail pairs, each of which is reinforced according to the relevant function, the two work together to play a better role; at the same time, the rolling guide pair is used to reduce the power consumption of the drive device and extend its service life by taking advantage of its low motion resistance and wear.

[0011] More preferably, the load-bearing guide rail pair and the yaw control guide rail pair both adopt a double roller structure, so as to improve stability through the double roller structure.

[0012] Still further preferably, the two main bearing rollers in the bearing guide pair used to form the double roller structure fit in the groove of the same bearing guide member, the bearing guide member is located at the back of the main telescopic ladder, and the two main bearing rollers are distributed on the support frame in the longitudinal direction of the ladder body; the two sway control rollers in the sway control guide pair used to form the double roller structure fit in the guide grooves of the two sway control guide groove members respectively, and form two sway control guide pairs, the two sway control guide groove members are respectively located at the back and side of the fixed ladder, the two sway control guide pairs are mainly used to control the pitch sway, and the sway control guide pair located at the side is also used to control the left and right sway. By realizing the main functions of a plurality of guide pair structures with different main functions, reliable bearing and sway control can be ensured; wherein, the bearing guide groove and the clearance on both sides of the main bearing roller can be controlled through reasonable structural size design, and auxiliary control of the left and right sway can also be formed.

[0013] It is further preferred that the yaw control roller located on the side of the fixed ladder is arranged through a mounting plate, and a shock-absorbing pad is arranged on the side of the mounting plate facing the support frame. When the main telescopic ladder is fully extended, the shock-absorbing pad eliminates the gap between the opposite sides of the mounting plate and the support frame and absorbs the energy of left and right shaking to ensure the stability of the extended state.

[0014] More preferably, the support frame is further provided with a gap adjustment roller, the gap adjustment roller is located between the two main load-bearing rollers, and the gap adjustment roller applies a force to the main telescopic ladder in the direction of the main load-bearing rollers. The gap adjustment roller is used to adjust the telescopic movement gap of the main telescopic ladder to ensure flexible operation and small pitch and roll, and eliminate or reduce the shaking under the dynamic load condition of passengers getting on and off the ladder.

[0015] Preferably, the dragging structure is composed of a pulling member and a dragging receiving member that can form an abutment, the dragging receiving member is fixed on the intermediate ladder; the pulling member is fixed on the main telescopic ladder. To ensure reliable dragging; at the same time, a retracting push connection structure can be set between the two to ensure the normal retraction of the intermediate ladder, thereby eliminating the hidden danger that the intermediate ladder cannot automatically retract under the action of gravity due to stagnation; obviously, a fall-back limiting member should also be set between the intermediate ladder and the fixed ladder to limit the retraction limit position.

[0016] Preferably, a locking mechanism is provided at the front end of the fixed ladder to prevent the main telescopic ladder from sliding down, and the locking mechanism has a first claw and a second claw driven by a locking oil cylinder, and the two claws correspond to the two travel sections of the main telescopic ladder respectively, so as to form an anti-slip locking for the main telescopic ladder in the two travel sections respectively. By locking the main telescopic ladder, the main telescopic ladder and the intermediate ladder can be simultaneously locked against retreat. In a specific setting, two locking components for locking are provided on the main telescopic ladder, and when one claw locks the corresponding locking component, the other claw has a spatial distance with the corresponding locking component that does not interfere with each other.

[0017] Preferably, the intermediate ladder guide rail pair is composed of a groove of a customized channel steel and an intermediate roller located in the groove; the intermediate roller is arranged on the fixed ladder; the customized channel steel constitutes the side frame edge of the intermediate ladder frame; wherein the roller adopts a composite bearing structure; the groove profile of the customized channel steel is adapted to the generatrix of the two rolling bodies on the composite bearing. The rolling guide rail pair structure of the composite bearing is formed, and the rolling guide rail pair structure is used to ensure that the intermediate ladder is flexible in extension and retraction, and good pitch tilt limitation and left and right yaw limitation effects can be obtained; and the composite bearing products and the matching channel steel profiles can be directly purchased for manufacturing, thereby reducing costs.

[0018] When actually used for boarding vehicles, in order to improve the trafficability of the vehicle, it is best to set the first step of the fixed ladder to a hidden step structure that can be hidden.

[0019] To achieve the second purpose, the present invention adopts the following technical solution.

[0020] A boarding vehicle comprises a self-propelled vehicle chassis and a boarding ladder mounted on the vehicle chassis; the boarding ladder is a two-stage telescopic boarding ladder that realizes the first invention objective.

[0021] The present invention adopting the foregoing solution has a three-section boarding ladder on the boarding vehicle, which is a three-section boarding ladder with two-stage telescopic ladders and has the same structural characteristics and excellent properties as the foregoing boarding ladder.

[0022] The beneficial effects of the present invention are that the boarding ladder has a larger height adjustment range, can adapt to more passenger aircraft models, can reduce airport operation costs, and has a stable structure, a compact layout, reliable functions, and a long service life. The boarding vehicle has the same structural characteristics and excellent properties as the boarding ladder. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the structural schematic axonometric view of the present invention.

[0024] Figure 2 is the structural schematic front view of the present invention.

[0025] Figure 3 is the partial structural schematic axonometric view of the boarding ladder in the present invention.

[0026] Figure 4 is the present invention Figure 3 enlarged view of part A.

[0027] Figure 5 is the partial structural front view of the front end of the fixed ladder in the present invention.

[0028] Figure 6 is the partial structural axonometric view of the front end of the fixed ladder in the present invention.

[0029] Figure 7 is the present invention Figure 6 enlarged view of part B.

[0030] Figure 8 is the partial structural axonometric view of one side of the rear end of the main telescopic ladder in the present invention.

[0031] Figure 9 is the partial structural axonometric view of the other side of the rear end of the main telescopic ladder in the present invention.

[0032] Figure 10 is the structural schematic axonometric view of the intermediate ladder in the present invention.

[0033] Figure 11 is the present invention Figure 10 enlarged view of part C.

[0034] Figure 12 is the present invention Figure 3 enlarged view of part D.

[0035] Figure 13 is the structural schematic axonometric view of the locking mechanism for preventing the main telescopic ladder from slipping in the present invention.

[0036] Figure 14 It is an isometric structural schematic diagram of the hidden step in the extended state in the present invention.

[0037] Figure 15 It is the front elevation structural schematic diagram of the hidden step in the extended state in the present invention.

[0038] Figure 16 It is an isometric structural schematic diagram of the hidden step in the retracted state in the present invention.

[0039] Figure 17 It is the front elevation structural schematic diagram of the hidden step in the retracted state in the present invention.

[0040] Figure 18 It is a partial structural schematic diagram of the hidden step with a second limiting structure in the present invention.

[0041] Figure 19 It is an isometric structural schematic diagram of the fixed ladder in the present invention, wherein the first-level step is in the extended state.

[0042] Figure 20 It is an isometric structural schematic diagram of the fixed ladder in the present invention, wherein the first-level step is in the retracted state.

[0043] Figure 21 It is an isometric partial structural schematic diagram of the boarding platform in the present invention. Detailed implementation mode

[0044] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments described herein.

[0045] Embodiment 1, referring to Figure 1 、 Figure 2 , a two-stage telescopic boarding ladder, comprising a fixed ladder 100 and a main telescopic ladder 200. The front end of the fixed ladder 100 is provided with a first hinge portion, and a lifting machine 600 is hinged to the first hinge portion. The rear end of the fixed ladder 100 is provided with a second hinge portion; the front end of the main telescopic ladder 200 is provided with a boarding platform 500, and the main telescopic ladder 200 is connected with a main ladder driving oil cylinder 220; further comprising an intermediate ladder 300 located between the fixed ladder 100 and the main telescopic ladder 200. Both the intermediate ladder 300 and the main telescopic ladder 200 are telescopically connected to the fixed ladder 100 through corresponding guide rail pair structures, and the intermediate ladder 300 and the main telescopic ladder 200 have a dragging structure for dragging the intermediate ladder 300 to extend synchronously after the main telescopic ladder 200 extends a set distance; in combination with Figure 3 、 Figure 10 、 Figure 11 、 Figure 12, the intermediate ladder 300 is located inside the ladder frame of the fixed ladder 100, and the intermediate ladder guide rail pair between the intermediate ladder 300 and the fixed ladder 100 is located between the opposite side walls of the fixed ladder frame and the intermediate ladder frame 301; an extended length limit block 102 for restricting the extended length of the main telescopic ladder 200 is provided on the fixed ladder 100.

[0046] See Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , a support frame 400 is fixedly connected to the back surface of the front end of the ladder frame of the fixed ladder 100, and there is a space for the main telescopic ladder 200 to telescopically move between the support frame 400 and the fixed ladder 100; both the fixed ladder 100 and the intermediate ladder 300 are located in front of the main telescopic ladder 200. Among them, the guide rail pair between the fixed ladder 100 and the main telescopic ladder 200 is composed of two sub-guide rail pairs; the two sub-guide rail pairs are respectively composed of a load-bearing guide rail pair and a yaw control guide rail pair; and both the load-bearing guide rail pair and the yaw control guide rail pair adopt a rolling guide rail structure. Among them, both the load-bearing guide rail pair and the yaw control guide rail pair adopt a double-roller structure. Specifically, the two main load-bearing rollers 401 in the load-bearing guide rail pair for forming the double-roller structure are fitted in the groove of the same load-bearing guide member 201, the load-bearing guide member 201 is located on the back surface of the main telescopic ladder 200, and the two main load-bearing rollers 401 are longitudinally distributed on the support frame 400 along the ladder body; the two yaw control rollers 202 in the yaw control guide rail pair for forming the double-roller structure are respectively fitted in the guide grooves of the two yaw control guide groove members, and two yaw control guide rail pairs are formed, the two yaw control guide groove members are respectively located on the back surface and the side surface of the fixed ladder 100, the two yaw control guide rail pairs are mainly used to control pitch yaw, and the yaw control guide rail pair located on the side surface is also used to control left-right yaw. At the same time, the extended length limit block 102 is located at the front end of the guide groove of the side yaw control guide groove member 103 on the side surface, and the side yaw control guide groove member 103 is formed by the side frame beam of the ladder frame of the fixed ladder 100, and this side frame beam is made of channel steel, and an angle steel 104 is welded in the groove of this channel steel to make the groove narrower to adapt to the diameter of the corresponding yaw control roller 202; the back yaw control guide groove member 105 located on the back surface of the ladder frame of the fixed ladder 100 is formed by bending a plate and is welded to the channel steel forming the side frame beam of the ladder frame. The yaw control roller 202 located on the side surface of the fixed ladder 100 is arranged through a mounting plate 203, and a shock pad 204 is arranged on the side surface of the mounting plate 203 facing the support frame 400.

[0047] In addition, a gap adjustment roller 402 is provided on the support frame 400, and the gap adjustment roller 402 is located between the two main load-bearing rollers 401. The gap adjustment roller 402 applies a force to the main telescopic ladder 200 in the direction of the main load-bearing rollers 401; the gap adjustment roller 402 is provided on the adjustment bracket 403, and the adjustment bracket 403 is provided on the support frame 400 in an adjustable position. The dragging structure is composed of a pulling member 205 and a dragging receiving member 303 that can form an abutment. The dragging receiving member 303 is fixed on the intermediate ladder frame 301 of the intermediate ladder 300; the pulling member 205 is fixed on the ladder frame longitudinal beam 207 of the main telescopic ladder 200; the yaw control roller 202 of the yaw control guide rail pair located on the back of the fixed ladder 100 is arranged at the end of the ladder frame longitudinal beam 207, and most of it is hidden in the groove of the channel steel constituting the ladder frame longitudinal beam 207, and the top end emerges from the hollow part on the side wall of the channel steel, one end of the roller shaft of the yaw control roller 202 is connected to the bottom wall of the channel steel, and the other end is connected to the sealing plate 208, and the sealing plate 208 is blocked at the notch of the channel steel.

[0048] The intermediate ladder frame 301 forms a rectangular frame structure through the frame edges on both sides and the two end beams, and the intermediate ladder step 302 is fixedly connected to the intermediate ladder frame 301; the frame edges on both sides of the intermediate ladder frame 301 have a rear extension section, and the outer side of the rear extension section and the inner side of the fixed ladder 100 form an intermediate ladder guide rail auxiliary structure; the intermediate ladder frame 301 is also provided with a fall-back limiting member 304, which is used to limit the extreme fall-back position of falling back under the action of gravity. The intermediate ladder frame 301 is provided with a crossbeam corresponding to each intermediate ladder step 302, and the intermediate ladder step 302 at the front end is supported on the front side beam. The intermediate ladder guide rail auxiliary is composed of a groove of a customized channel steel and an intermediate roller 101 located in the groove; the intermediate roller 101 is arranged by being fixedly connected to an intermediate roller seat 106 provided on the fixed ladder 100, and the intermediate roller seat 106 is a long strip plate structure; the customized channel steel constitutes the side frame edge of the intermediate ladder frame 301. The groove of the customized channel steel is adapted to the composite bearing constituting the intermediate roller 101, and the groove profile is adapted to the generatrix of the two rolling elements on the composite bearing. The fall-back limiting member 304 is arranged in the groove of the channel steel, and the fall-back limiting member 304 abuts against the front end of the intermediate roller seat 106 to limit the fall-back limit position of the intermediate ladder 300. A reinforcing rib 305 and a lifting ring 306 are also arranged at the front end of the groove of the channel steel.

[0049] In addition, drag receiving members 303 are provided on both side frame edges of the middle ladder frame 301. The drag receiving members 303 are located on the lower end surfaces of the front ends of the side frame edges. Retraction drive receiving blocks 307 are also provided on both side frame edges of the middle ladder frame 301. The retraction drive receiving blocks 307 are located in front of the drag receiving members 303 and extend outward to form a dislocation in the width and height directions with the drag receiving members 303. A retraction drive block 206 is provided on the ladder frame of the main telescopic ladder 200. The retraction drive block 206 is used to push the middle ladder frame 300 to retract forcibly. The step treads of the middle ladder steps 302 are detachably installed on angle steel brackets. The angle steel brackets are welded and fixed on both side frame edges and supported on the corresponding cross beams or end beams. One side edge of the angle steel bracket is fitted to the side frame edge, and the other side edge is fitted to the step tread.

[0050] See Figure 2 , a locking mechanism for preventing the main telescopic ladder 200 from slipping is provided at the front end of the fixed ladder 100. The locking mechanism has a first claw 702 and a second claw 703 driven by a locking oil cylinder 701. The two claws respectively correspond to two stroke segments of the main telescopic ladder 200 to form an anti-slip locking for the main telescopic ladder 200 within the two stroke segments.

[0051] See Figure 13 , including a locking claw driven by a locking oil cylinder 701; the locking claw is composed of two distributed first claws 702 and second claws 703. The two claws respectively correspond to two lifting stroke segments of the member to be locked to form an anti-slip locking for the main telescopic ladder 200 within the two lifting stroke segments; the locking oil cylinder 701 is composed of two oil cylinders, a first oil cylinder 701A and a second oil cylinder 701B. The bottom ends of the cylinder bodies of the two oil cylinders are fixedly connected together.

[0052] Among them, the first claw 702 is fixedly connected to a claw shaft 704. The claw shaft 704 is rotatably provided on the base member; the second claw 703 is hinged to the base member. A crank-link mechanism is connected between the second claw 703 and the claw shaft 704. Specifically, the crank-link mechanism includes a crank 706 and a connecting rod 407. The crank 706 is fixedly connected to the claw shaft 704; the connecting rod 407 is respectively hinged to the crank 706 and the second claw 703 at both ends. The claw shaft 704 is rotatably connected to a mounting seat 708. The mounting seat 708 is fixedly connected to the support frame 400; a driving arm 709 is also fixedly connected to the claw shaft 704. The free end of the driving arm 709 is hinged to one end of the locking oil cylinder 701. The other end of the locking oil cylinder 701 is hinged to an oil cylinder seat 705. The oil cylinder seat 705 is fixedly connected to the support frame 400.

[0053] Specifically, a first jaw 702 and a second jaw 703 are respectively provided at both ends of the jaw shaft 704. The two first jaws 702 at both ends and the two second jaws 703 at both ends are symmetrically arranged left and right in a one-to-one correspondence; the locking oil cylinder 701 is located on the axis of symmetry of the left-right symmetry. Among them, the main telescopic ladder 200 includes two channel steels 230 with their groove bottoms facing away from each other and arranged at a set distance. A first locking block 231 is fixedly connected to the back of the groove bottom of the channel steel 230. Multiple tooth-shaped locking structures 231a are provided on the first locking block 231. The multiple tooth-shaped locking structures 231a correspond to the first telescopic stroke of the main telescopic ladder 200. The jaw shaft 704 is driven by one of the first oil cylinder 701A or the second oil cylinder 701B to rotate by a small angle. The first jaw 702 forms an extended lock for the main telescopic ladder 200 by combining with the tooth-shaped locking structure 231a, preventing the main telescopic ladder 200 from slipping back during the first telescopic stroke section. During this process, the second jaw 703 never contacts or interferes with the side wall of the channel steel 230. A cross-bar-shaped locking structure 230a is provided on the side wall of the channel steel 230. The cross-bar-shaped locking structure 230a corresponds to the second telescopic stroke of the telescopic ladder. The jaw shaft 704 is driven by the combined action of the first oil cylinder 701A and the second oil cylinder 701B to rotate by a large angle. The second jaw 703 forms an extended lock for the main telescopic ladder 200 by combining with the cross-bar-shaped locking structure 230a, preventing the ladder frame from slipping back during the second telescopic stroke section. During this process, the end of the ladder frame is far from the first jaw 702, and the second jaw 703 never contacts or interferes with the end of the channel steel 230. Among them, the locking oil cylinder 701 can also be an ordinary single-piston rod oil cylinder, or a double-piston rod that extends at both ends simultaneously, or a two-stage oil cylinder, used to replace the combination of the two single-piston rod oil cylinders with superposed strokes mentioned above. When using the aforementioned alternative oil cylinders, a travel switch is used to control the oil cylinder stroke to control the oil cylinder stroke so that it corresponds to the two strokes in the locked component.

[0054] The aforementioned first telescopic stroke mainly corresponds to the anti-slip lock during the self-telescoping of the main telescopic ladder 200 and the partial telescoping of the intermediate ladder 300; the second stroke section corresponds to the anti-slip lock of the last one or two ladder steps of the intermediate ladder 300.

[0055] The cylinder body of the main ladder driving oil cylinder 220 is fixed on the back of the fixed ladder 100, and the front end of the piston rod is hinged on the back of the main telescopic ladder 200. To adapt to the structural feature that the working stroke of the two-stage telescopic ladder structure is greater than the length of the cylinder body, the main ladder driving oil cylinder 220 adopts a two-stage oil cylinder structure, so that the total stroke formed by the sequential telescoping of the two-stage piston rods meets the structural requirement of being greater than the length of the cylinder body.

[0056] To ensure the passing performance of the vehicle when used for boarding locomotives, the first ladder step of the fixed ladder 100 adopts a hidden structure. See Figure 14 、 Figure 15 、 Figure 16 、Figure 17 , Figure 19 , Figure 20 , the hidden step includes a rectangular step body 110 and also includes two bent arms 111 hinged at one end to the inner side of the fixed ladder frame; the step body 110 is in an L shape with a horizontal section longer than a vertical section, and the upper ends of the L-shaped vertical sections on both sides of the step body 110 are respectively hinged to the free ends of the two bent arms 111; a step driving cylinder 112 formed by an electric cylinder is hinged to the upper end at the rear side of the L-shaped vertical section of the step body 110, and the cylinder body of the step driving cylinder 112 is hinged to the ladder frame of the fixed ladder 100; the step driving cylinder 112 pulls the step body 110 by retracting its cylinder rod and drives the free end of the bent arm 111 to swing upward to the upper limit position, and the L-shaped horizontal section of the step body 110 is located at the upper limit position; a first limiting structure is formed between the hinged parts of the step body 110 and the bent arms 111; the step driving cylinder 112 pushes the step body 110 by extending its cylinder rod and drives the free end of the bent arm 111 to swing downward, so that in a state where the two components of the first limiting structure are abutted against each other, the bent arm 111 and the step body 110 are located at the lower limit position.

[0057] Wherein, the first limiting structure includes a frame limiting element 110a, and the frame limiting element 110a is fixedly connected or integrally formed on the step body 110 and is located on the end face of the step body 110. The frame limiting element 110a restricts the L-shaped horizontal section of the step body 110 to the lower limit position by abutting against the side surface of the free end extension section 111a of the bent arm 111. The frame limiting element 110a is in a block structure, and the frame limiting element 110a forms a surface contact connection relationship with the free end extension section 111a of the bent arm 111. The free end extension section 111a extends outward from the hinged part of the bent arm 111 and the step body 110 by the bent arm 111.

[0058] In addition, a tension spring 113 is further provided between the rear side of the L-shaped vertical section of the step body 110 and the ladder frame of the fixed ladder 100, and the connection point of the tension spring 113 on the step body 110 is located at the lower end of the L-shaped vertical section.

[0059] As Figure 15 shown, when the step body 110 is at the lower limit position, the step body 110 is in an extended state, the position of the connection point of the tension spring 113 and the ladder frame is point A, which is higher than the hinge point B of the tension spring 113 and the step body 110 in height; the tension spring 113 slopes downward from point A.

[0060] As Figure 17As shown, when the step body 110 is at the upper limit position, the step body 110 is in a retracted state, and the connection point of the tension spring 113 and the ladder frame is at A, which is lower in height than the hinge point C of the tension spring 113 and the step body 110; the tension spring 113 tilts upward from point A. And when the step body 110 is at the upper limit position, the hinge point D of the cylinder body of the step driving cylinder 112 and the ladder frame, the hinge point E of the bent arm 111 and the step body 110, and the hinge point F of the bent arm 111 and the ladder frame are located on the same straight line.

[0061] In this embodiment, an unlocking elastic member can also be provided above the bent arm 111 at the upper limit position, and the unlocking elastic member elastically abuts against the bent arm 111 to release the dead point state when the step driving cylinder 112 is unloaded, thereby smoothly entering the extension process of the step body 110; the reasonable clearance of the hinged cooperation of the three hinge points can also be used to release the dead point state by gravity when the step driving cylinder 112 is unloaded, wherein, as shown in Figure 4 The three points D, E and F shown are arranged in a gradually rising manner, and the unlocking effect by relying on the deadweight is better.

[0062] In this embodiment, an upper limit position limiting member may also be provided on the ladder frame to prevent the three hinge points from being in the same straight line, thereby avoiding the dead point problem. The step driving cylinder 112 may also be composed of a hydraulic cylinder or a pneumatic cylinder.

[0063] In order to improve the structural stability of the boarding platform, a sub-frame is arranged in the main frame, which is telescopically moved synchronously with the crossbeam, and the sub-frame is hinged to the crossbeam. At the same time, sub-hinges are added on both sides of the front end of the sub-frame, and the sub-frame and sub-hinges are used to increase the position for bearing the pedals, thereby effectively reducing the horizontal hollow size and eliminating or reducing the safety hazard of stepping into the air. The details are as follows.

[0064] See also Figure 21 The boarding platform 500 includes a main frame 501, a crossbeam 502, a main hinge 503 and a sub-frame driving cylinder 504; a sub-frame 505 is arranged inside the main frame 501, and a linear movable guide rail pair is provided between the sub-frame 505 and the main frame 501; the middle part of the front end of the sub-frame 505 is hinged to the crossbeam 502, and sub-hinges 506 are also provided between the two sides of the front end of the sub-frame 505 and the crossbeam 502; the sub-frame driving cylinder 504 is connected between the middle part of the rear end of the sub-frame 505 and the main frame 501.

[0065] Among them, the linear moving guide pair adopts a rolling guide pair structure in which rollers 507 cooperate with a guide groove; the rollers 507 adopt a composite bearing structure; the guide groove is formed by the groove of a customized channel steel, and the contour of the groove is adapted to the generatrices of two rolling elements on the rollers 507; and the customized channel steel also constitutes the longitudinal reinforcing beam of the main frame 501; the rollers 507 are arranged on the frame side beam of the sub-frame 505.

[0066] In addition, a rubber hose 508 is provided on the front side of the cross beam 502. A pressing block is provided inside the rubber hose 508. The rubber hose 508 is fixed to the cross beam 502 by the pressing block, and the front end of the pressing block is arc-shaped. Two compression type travel switches 509 are also provided on the cross beam 502. The contact rod of the compression type travel switch 509 is elastically telescopic and arranged on the cross beam 502. Among them, the two compression type travel switches 509 are arranged side by side at a certain distance in the middle of the cross beam 502, and the front end of the contact rod passes through the rubber hose 508 and is exposed outside.

[0067] A shock absorber 510 is also provided between the sub-frame driving cylinder 504 and the main frame 501. The shock absorber 510 is connected in series at the tail end of the sub-frame driving cylinder 504, and the two are hinged. Among them, the sub-frame driving cylinder 504 is composed of an electric cylinder.

[0068] Example 2, see Figure 18 , the frame limiting element 110a in the hidden step adopts a cylindrical structure, or any cylindrical structure in which the part in contact with the side of the free end extension 111a of the bent arm 111 is an arc surface, so that the first limiting structure forms a position limit through line contact; a second limiting structure is formed between the bent arm 111 and the ladder frame of the fixed ladder 100, and the second limiting structure is used to limit the bent arm 111 to the lower limit position. The second limiting structure includes a bent arm limiting element 114, and the bent arm limiting element 114 is a block structure or a rod structure. The bent arm limiting element 114 is fixedly connected to the ladder frame of the fixed ladder 100, and the bent arm limiting element 114 limits the bent arm 111 to the lower limit position by abutting against the proximal side surface of the bent arm 111.

[0069] Among them, when the bent arm limiting element 114 adopts a limiting block, it is fixed alone inside the longitudinal beam; when adopting a rod-shaped member, it is composed of the reinforcing tie rods at the corresponding positions of the two longitudinal beams, and can also be specially set, and the function of the reinforcing tie rods is strengthened.

[0070] The remaining structures of this embodiment are the same as those of Embodiment 1 or 2, and will not be elaborated here.

[0071] Example 3, see Figure 1 、 Figure 2 , a boarding vehicle, including a self-propelled vehicle chassis 800 and a boarding ladder carried on the vehicle chassis 800; the boarding ladder is composed of the two-stage telescopic boarding ladder of Embodiment 1 or 2.

[0072] Among them, the two-stage telescopic boarding ladder is hinged at the lower end of the fixed ladder 100 to the tail of the vehicle chassis 800. The lift 600 is located at the front close to the cab only. The main telescopic ladder 200 telescopes longitudinally along the vehicle. The boarding platform 500 has a combined movement of lifting and moving forward and backward following the distal end of the main telescopic ladder 200. And in the retracted state of the boarding ladder, the boarding platform 500 is located above the top of the cab.

[0073] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A two-stage telescopic boarding ladder, comprising a fixed ladder (100) and a main telescopic ladder (200). The front end of the fixed ladder (100) is provided with a first hinge portion, and a lifting machine (600) is hinged to the first hinge portion. The rear end of the fixed ladder (100) is provided with a second hinge portion; the main telescopic ladder (200) is connected with a main ladder driving oil cylinder; It is characterized in that, it further comprises an intermediate ladder (300) located between the fixed ladder (100) and the main telescopic ladder (200). Both the intermediate ladder (300) and the main telescopic ladder (200) are telescopically connected to the fixed ladder (100) through corresponding guide rail pair structures, and the intermediate ladder (300) and the main telescopic ladder (200) have a dragging structure for dragging the intermediate ladder (300) to extend synchronously after the main telescopic ladder (200) extends a set distance. The intermediate ladder (300) is located inside the ladder frame of the fixed ladder (100), and the intermediate ladder guide rail pair between the intermediate ladder (300) and the fixed ladder (100) is located between the opposite side walls of the fixed ladder frame and the intermediate ladder frame (301). The guide rail pair between the fixed ladder (100) and the main telescopic ladder (200) is composed of two sub-guide rail pairs; the two sub-guide rail pairs are respectively composed of a load-bearing guide rail pair and a yaw control guide rail pair; and both the load-bearing guide rail pair and the yaw control guide rail pair adopt rolling guide rail structures; and both the load-bearing guide rail pair and the yaw control guide rail pair adopt double-roller structures.

2. The two-stage telescopic boarding ladder according to claim 1, It is characterized in that, a support frame (400) is fixedly connected to the front end of the ladder frame of the fixed ladder (100). The support frame (400) extends from the side surface to the back surface of the fixed ladder frame. There is a telescopic movement space for the main telescopic ladder (200) between the support frame (400) and the back surface of the fixed ladder (100); both the fixed ladder (100) and the intermediate ladder (300) are located in front of the main telescopic ladder (200); and the upper and lower parts of the support frame (400) are triangular, and the first hinge portion is arranged through the support frame (400) and is located at a downward angle in the triangle.

3. The two-stage telescopic boarding ladder according to claim 2, It is characterized in that, two main load-bearing rollers (401) in the load-bearing guide rail pair for forming the double-roller structure are fitted in the grooves of the same load-bearing guiding member (201). The load-bearing guiding member (201) is located on the back surface of the main telescopic ladder (200), and the two main load-bearing rollers (401) are longitudinally distributed on the support frame (400) along the ladder body; two yaw control rollers (202) in the yaw control guide rail pair for forming the double-roller structure are respectively fitted in the guide grooves of two yaw control guiding groove members to form two yaw control guide rail pairs. The two yaw control guiding groove members are respectively located on the back surface and the side surface of the fixed ladder (100). The two yaw control guide rail pairs are mainly used to control pitch yaw, and the yaw control guide rail pair located on the side surface is also used to control left-right yaw.

4. The two-stage telescopic boarding ladder according to claim 3, It is characterized in that, A sway control roller (202) matched with the sway control guide groove component on the side of the fixed ladder (100) is arranged via a mounting plate (203), and a shock absorbing pad (204) is arranged on the side of the mounting plate (203) facing the support frame (400).

5. The two-stage telescopic boarding ladder according to claim 2, It is characterized in that The support frame (400) is also provided with a gap adjustment roller (402), and the gap adjustment roller (402) is located between the two main bearing rollers (401). The gap adjustment roller (402) applies a force on the main telescopic ladder (200) in the direction of the main bearing rollers (401).

6. The two-stage telescopic boarding ladder according to claim 1, It is characterized in that The dragging structure is composed of a pulling member (205) capable of forming an abutment and a dragging receiving member (303); the dragging receiving member (303) is fixed on the intermediate ladder (300); and the pulling member (205) is fixed on the main telescopic ladder (200).

7. A two-stage telescopic boarding ladder according to any one of claims 1 to 6, It is characterized in that A locking mechanism is provided at the front end of the fixed ladder (100) to prevent the main telescopic ladder (200) from sliding down, and the locking mechanism comprises a first clamping claw (702) and a second clamping claw (703) driven by a locking oil cylinder (701), the two clamping claws respectively corresponding to two travel sections of the main telescopic ladder (200), so as to form an anti-slip locking for the main telescopic ladder (200) in the two travel sections.

8. A two-stage telescopic boarding ladder according to any one of claims 1 to 6, It is characterized in that The intermediate ladder guide pair is composed of a groove of a customized channel steel and an intermediate roller (101) located in the groove; the intermediate roller (101) is arranged on the fixed ladder (100); the customized channel steel constitutes the side frame edge of the intermediate ladder frame (301); wherein the roller adopts a composite bearing structure; the groove profile of the customized channel steel is adapted to the generatrix of two rolling bodies on the composite bearing.

9. A boarding vehicle, comprising a self-propelled vehicle chassis (800) and a boarding ladder mounted on the vehicle chassis (800); It is characterized in that The boarding ladder is composed of the two-stage telescopic boarding ladder described in any one of claims 1 to 8.

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