Material transport device and method of using the same

Abstract

The present invention relates to the field of bridge construction, and discloses a material transport device and a method for using the same, comprising a transport vehicle and a carrying bracket arranged on the transport vehicle, wherein the carrying bracket comprises two movable rods and two hydraulic cylinders arranged alternately at four corners in sequence, wherein the movable rod is configured to perform lifting and lowering movements in a vertical direction, and the carrying bracket further comprises a spring, a linkage member and a clamping mechanism, wherein the spring is arranged on the movement path of the movable rod, and the linkage member is connected to the clamping mechanism, and when the movable rod descends to a predetermined position, the movable rod squeezes the spring and triggers the linkage member to drive the clamping mechanism to intermittently clamp the movable rod in a horizontal direction, and by arranging a spring below the movable rod, the spring can play a buffering role on the movable rod; the clamping mechanism uses friction and clamping force to act on the descending movable rod, and can also play a buffering role on it.

Description

Technical Field

[0001] The invention relates to the field of bridge construction, and in particular to a material transport device and a use method thereof. Background Art

[0002] Box beam cutting is usually used in projects such as bridge demolition or maintenance. In the process of box beam cutting, a self-propelled modular flatbed truck is usually used. This truck is a modular heavy-duty carrier. By installing corresponding carrying brackets on the self-propelled modular flatbed truck, it can support or carry the cut and separated box beam.

[0003] In the process of cutting the box beam, in order to shorten the construction time and reduce the impact on the road, the construction party usually tries to reduce the number of cutting times, which means that the cut and separated box beam is large and heavy. In particular, the box beam after cutting and separation of existing large bridges weighs hundreds of tons. The existing technology usually uses the corresponding hydraulic drive mechanism on the carrying bracket to support the cut and separated box beam, and then drives the hydraulic drive mechanism to drive the box beam to descend; because the box beam is too heavy, in order to protect the hydraulic drive mechanism, the descending stroke is usually divided into multiple sections;

[0004] However, when the overall weight of the box girder remains unchanged, when the hydraulic cylinder drives the box girder down to the last section, as the oil in the oil chamber inside the hydraulic cylinder continues to decrease, its supporting performance tends to be unstable. At this time, driving the box girder to descend again will easily cause structural vibration and impact, and further damage the hydraulic drive mechanism. Therefore, it is necessary to provide corresponding protection for the hydraulic cylinder when it descends to the last section. Summary of the invention

[0005] The purpose of this application is to provide a material transport device and a method of using the same to solve the above problems. The specific technical solution is as follows:

[0006] A material transport device includes a transport vehicle and a carrying bracket arranged on the transport vehicle, the carrying bracket includes two movable rods and two hydraulic cylinders alternately arranged at four corners in sequence, the movable rod is configured to perform lifting and lowering movements in a vertical direction, the carrying bracket also includes a spring, a linkage and a clamping mechanism, the spring is arranged on the movement path of the movable rod, the linkage is connected to the clamping mechanism, and when the movable rod descends to a predetermined position, the movable rod squeezes the spring and triggers the linkage to drive the clamping mechanism to intermittently clamp the movable rod in a horizontal direction.

[0007] Preferably, it further comprises a base, a first groove is provided at the center of the top surface of the base and is used to accommodate part of the movable rod, the spring is arranged in the first groove, and an annular protrusion is provided on the side of the movable rod and abuts against the spring.

[0008] Preferably, the movable rod includes a top cover, a main rod and a support rod, the main rod and the support rod are arranged in parallel and are respectively connected to the top cover, the base is provided with a second groove, the second groove is arranged on the side of the first groove, the main rod is arranged in the first groove, and the support rod is arranged in the second groove.

[0009] Preferably, the linkage member is arranged in the second groove, and the linkage member includes a rack, a main gear, a large gear, a pinion and a limit plate. The rack is arranged below the support rod, and the inner wall of the second groove is connected with a rotating shaft that rotates therewith. The main gear and the large gear are coaxially connected to the rotating shaft, and the rack is meshed with the main gear for transmission. The pinion is arranged on the side of the large gear and meshed with it for transmission. The limit plate is provided with a square accommodating groove arranged in the vertical direction, and a rotatable roller is coaxially connected to the pinion, and the roller is arranged in the square accommodating groove, and the clamping mechanism is connected to the limit plate.

[0010] Preferably, the clamping mechanism includes a cross bar and a clamping block arranged in a horizontal direction, the base is provided with a channel connecting the first groove and the second groove to install the cross bar, one end of the cross bar is arranged in the first groove and connected to the clamping block, the other end of the cross bar is arranged in the second groove and connected to the limit plate, a rectangular hole is provided on the cross bar, the channel is connected to the limit column, and the limit column is arranged in the rectangular hole.

[0011] Preferably, the carrying bracket further comprises a scissor-type hydraulic lift, which is arranged on the transport vehicle and connected to the movable rod.

[0012] A method of use, applied to the above-mentioned material transport device, comprises the following steps:

[0013] Step 1: Prepare at least six transport vehicles and install a carrying bracket on each transport vehicle. Three transport vehicles are configured as the first group, two transport vehicles are configured as the second group, and one transport vehicle is configured as the spare group;

[0014] Step 2: Drive the transport vehicle of the first group to the bottom of the bridge to be demolished, park one transport vehicle of the first group under the center of the bridge to be demolished, and the other two transport vehicles of the first group are symmetrically arranged on both sides of the transport vehicle located in the center;

[0015] Step 3: driving the scissor-type hydraulic lift of the transport vehicle of the first group to raise the movable rod to abut against the box beam of the bridge to be demolished, and at the same time driving the hydraulic cylinder of the transport vehicle of the first group to rise to abut against the box beam of the bridge to be demolished;

[0016] Step 4: Cut the box beams of the bridge to be demolished from both sides, so that part of the box beams are cut and separated and carried by the transport vehicle of the first group;

[0017] Step 5: driving the scissor-type hydraulic lift of the transport vehicle of the first group to lower the movable rod once, and driving the hydraulic cylinder of the transport vehicle of the first group to lower once;

[0018] Step 6: Drive the transport vehicle of the second group to the bottom of the partial box girder, and insert a transport vehicle of the second group between two adjacent transport vehicles of the first group;

[0019] Step 7: drive the scissor-type hydraulic lift of the transport vehicle of the second group to raise the movable rod to abut against part of the box beam, and at the same time drive the hydraulic cylinder of the transport vehicle of the second group to rise to abut against part of the box beam, after the transport vehicle of the second group carries part of the box beam, drive the scissor-type hydraulic lift of the transport vehicle of the first group to lower the movable rod, and at the same time drive the hydraulic cylinder of the transport vehicle of the first group to lower, and then drive the transport vehicle of the first group to leave from under the part of the box beam;

[0020] Step 8: driving the scissor-type hydraulic lift of the transport vehicle of the second group to make the movable rod descend for the second time, and at the same time driving the hydraulic cylinder of the transport vehicle of the second group to descend for the second time;

[0021] Step 9: Drive the transport vehicle of the first group to the bottom of the partial box beam, and the parking position of the transport vehicle of the first group is the same as the parking position of the vehicle that is lowered once;

[0022] Step 10: driving the scissor-type hydraulic lift of the transport vehicle of the first group to raise the movable rod to abut against part of the box beam, and driving the hydraulic cylinder of the transport vehicle of the first group to rise to abut against part of the box beam, after the transport vehicle of the first group carries part of the box beam, driving the scissor-type hydraulic lift of the transport vehicle of the second group to lower the movable rod, and driving the hydraulic cylinder of the transport vehicle of the second group to lower, and then driving the transport vehicle of the second group to leave from under the part of the box beam;

[0023] Step 11: Drive the scissor-type hydraulic lift of the first group of transport vehicles to lower the movable rod three times, and at the same time drive the hydraulic cylinder of the first group of transport vehicles to lower three times until the part of the box beam drops to a predetermined height.

[0024] Preferably, during one descent, three transport vehicles are used to adjust part of the box girder to keep it balanced.

[0025] The beneficial effects of the present application are as follows: when the hydraulic cylinder descends to the last section, the present invention assists in supporting the box girder by arranging a movable rod to avoid damage to the hydraulic cylinder due to unstable supporting performance when the hydraulic cylinder descends to the last section; a spring is arranged under the movable rod, and the spring can buffer the movable rod; the clamping mechanism uses friction and clamping force to act on the descending movable rod, which can also have a certain buffering effect; the purpose of using the first group of transport vehicles and the second group of transport vehicles to alternately carry loads is to avoid a single position from being subjected to excessive stress for a long time, thereby reducing the loss and potential damage risk of equipment and bridge structures; through multiple small-amplitude descent operations rather than a large-amplitude descent, the descent process of the box girder can be more accurately controlled to ensure that the box girder finally reaches the predetermined position accurately.

[0026] Additional aspects and advantages of the present invention will be given in part in the description below, and in part will become apparent from the description below, or will be understood through the practice of the present invention. Of course, it is not necessary to achieve all of the advantages described above at the same time to implement any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 It is a structural schematic diagram of the present invention.

[0029] Figure 2 It is a structural schematic diagram of the movable rod of the present invention.

[0030] Figure 3 It is a structural schematic diagram of the clamping mechanism of the present invention.

[0031] Figure 4 It is a structural schematic diagram of the linkage member of the present invention.

[0032] Figure 5 It is another structural schematic diagram of the linkage part of the present invention.

[0033] Figure 6 It is another structural schematic diagram of the linkage part of the present invention.

[0034] Figure 7 It is a schematic diagram of step 2 of the present invention.

[0035] Figure 8 It is a schematic diagram of step seven of the present invention.

[0036] Fig. 9 It is a structural schematic diagram of the piggyback support of the present invention.

[0037] In the figure: 1, transport vehicle, 2, carrying bracket, 3, scissor-type hydraulic lift, 4, base, 5, linkage, 6, clamping mechanism, 7, spring, 21, top cover, 22, main rod, 23, support rod, 221, annular protrusion, 41, first groove, 42, second groove, 51, rack, 52, main gear, 53, large gear, 54, small gear, 55, limit plate, 56, roller, 61, cross bar, 62, clamping block, 611, rectangular hole, 612, limit column, 201, movable rod, 202, hydraulic cylinder. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0040] See also Figure 1-9 The present invention provides a material transport device and a method of using the same, which is mainly used to carry the box beams of large bridges after cutting and separation. The weight of such box beams is generally between 200 and 500 tons, wherein:

[0041] The material transport device includes a transport vehicle 1 and a carrying bracket 2 arranged on the transport vehicle 1. The carrying bracket 2 includes two movable rods 201 and two hydraulic cylinders 202 which are alternately arranged at four corners. The scissor-type hydraulic lift 3 is arranged on the transport vehicle 1 and connected to the movable rod 201. The movable rod 201 is driven to perform lifting and lowering movements in a vertical direction by the scissor-type hydraulic lift 3. The transport vehicle 1 can enter and dock under the bridge by driving the movable rod 201 downward by the scissor-type hydraulic lift 3, and the movable rod 201 can be driven upward by the scissor-type hydraulic lift 3 to make the movable rod 201 abut against the bottom surface of the bridge or the box girder, thereby bearing part of the bridge or the box girder.

[0042] Since the transport vehicle 1 has a strong carrying capacity, each transport vehicle 1 is usually equipped with two carrying brackets 2. In order to improve stability, in some embodiments, two movable rods 201 and two hydraulic cylinders 202 are alternately arranged at four corners, that is, each transport vehicle 1 has four movable rods 201 and four hydraulic cylinders 202 to carry the box beam, ensuring that the box beam can be lowered stably.

[0043] Although the above embodiment can carry a box beam weighing several hundred tons, it is difficult for the scissor-type hydraulic lift 3 to accurately control such a box beam, which easily leads to an unstable descending speed of the box beam. Whether it is stopping after descending too fast or a single descending distance is too long, it is easy to cause structural vibration and impact, thereby damaging the scissor-type hydraulic lift 3. Therefore, the present application also provides a better embodiment as follows:

[0044] See also Figure 2 The carrying bracket 2 of this embodiment further includes a spring 7 and a base 4. The spring 7 is arranged on the moving path of the movable rod 201. The center of the top surface of the base 4 is provided with a first groove 41 and is used to accommodate part of the movable rod 201. The spring 7 is arranged in the first groove 41. The side of the movable rod 201 is provided with an annular protrusion 221. Specifically, the spring 7 is sleeved on the movable rod 201 before compression. When the scissor-type hydraulic lift 3 drives the movable rod 201 to descend to a predetermined height, that is, it descends to the end section of the descending stroke of the hydraulic cylinder 202 (the last third section of the descending stroke of the hydraulic cylinder 202), the annular protrusion 221 abuts against the spring 7. If the movable rod 201 continues to descend, the spring 7 can play a buffering role.

[0045] It should be noted that the material of the spring 7 used in the present application is high carbon steel, the wire diameter d of the spring 7 is 80mm≤d≤95mm, the average diameter D is 650mm≤D≤800mm, the effective number of turns is 10 turns, and the turn spacing P is 70mm≤P≤92mm. Only the spring 7 of the above specifications can meet the buffering effect of the box beam in this application.

[0046] In order to further optimize the buffering effect, the present application also provides a preferred embodiment as follows, please refer to Figure 2 This embodiment also includes a linkage member 5 and a clamping mechanism 6. The linkage member 5 is connected to the clamping mechanism 6. When the movable rod 201 descends to a predetermined position, the movable rod 201 will trigger the linkage member 5 while squeezing the spring 7. The linkage member 5 drives the clamping mechanism 6 to intermittently clamp the movable rod 201 in the horizontal direction. In this process, the clamping mechanism 6 uses friction and clamping force to act on the descending movable rod 201, which can also play a certain buffering role on it.

[0047] See also Figure 2-6In some embodiments, the movable rod 201 includes a top cover 21, a main rod 22 and a support rod 23. The main rod 22 and the support rod 23 are arranged in parallel and are respectively connected to the top cover 21. The base 4 is provided with a second groove 42, and the second groove 42 is arranged on the side of the first groove 41. The main rod 22 is arranged in the first groove 41. The spring 7 is sleeved on the outer side of the bottom of the main rod 22, and the annular protrusion 221 is also integrally formed with the main rod 22. The support rod 23 is arranged in the second groove 42. The support rod 23 is slidably arranged in the second groove 42. One function of the support rod 23 is to assist the main rod 22 in guiding, and another function of the support rod 23 is to trigger the linkage member 5 when it descends;

[0048] The support rod 23 is arranged at the relative top of the second groove 42, and the linkage member 5 is arranged at the relative bottom of the second groove 42. The linkage member 5 includes a rack 51, a main gear 52, a large gear 53, a pinion 54 and a limiting plate 55. The rack 51 is arranged below the support rod 23. The inner wall of the second groove 42 is connected with a rotating shaft that rotates with it. The main gear 52 and the large gear 53 are coaxially connected to the rotating shaft. The rack 51 is meshed with the main gear 52 for transmission. The pinion 54 is arranged on the side of the large gear 53 and meshed with it for transmission. Specifically, in some preferred embodiments, an inner gear ring can also be installed on the outer side of the pinion 54 to cooperate with it, and the inner gear ring plays a limiting role on the pinion 54; and the limiting plate 55 is provided with a square accommodating groove arranged in the vertical direction, and a rotatable roller 56 is coaxially connected to the pinion 54. The roller 56 is arranged in the square accommodating groove, and the clamping mechanism 6 is connected to the limiting plate 55;

[0049] When the support rod 23 descends and pushes the rack 51 to descend, the rack 51 will drive the main gear 52 to rotate, and because the main gear 52 and the large gear 53 are coaxially connected to the rotating shaft, the large gear 53 will also be driven, and the large gear 53 will drive the small gear 54 to rotate. At this time, the small gear 54 rotates on itself and rotates around the large gear 53 at the same time. In the process of rotating around the large gear 53, the small gear 54 will push the limit plate 55 to move forward or backward, thereby driving the clamping mechanism 6 to approach or move away from the movable rod 201, thereby realizing the above-mentioned intermittent clamping of the movable rod 201.

[0050] In some embodiments, the clamping mechanism 6 includes a cross bar 61 and a clamping block 62 arranged in the horizontal direction, wherein the clamping block 62 is made of wear-resistant material, and the base 4 is provided with a channel connecting the first groove 41 and the second groove 42 to install the cross bar 61, that is, the cross bar 61 is slidably installed in the channel, and one end of the cross bar 61 is arranged in the first groove 41 and connected to the clamping block 62, and the other end of the cross bar 61 is arranged in the second groove 42 and connected to the limit plate 55. In addition, a rectangular hole 611 is provided on the cross bar 61, and the channel is connected to the limit column 612, and the limit column 6 12 is arranged in the rectangular hole 611. It can be understood that the above-mentioned channel will limit the cross bar 61 to ensure that the linkage part 5 can operate normally, and the use of the limiting column 612 in conjunction with the rectangular hole 611 can further improve the stability of the operation; it should be noted that the present invention is based on the hydraulic cylinder 202 as the main support, and the movable rod 201 only plays a buffering role at the end of the stroke of the hydraulic cylinder 202, and only after the hydraulic cylinder 202 and the movable rod 201 share most of the load can a more precise mechanical structure be used to assist the spring 7 in playing a buffering role.

[0051] The present application also provides a method for using the above-mentioned material transport device, comprising the following steps:

[0052] Step 1: prepare at least six transport vehicles 1, and install a carrying bracket on each transport vehicle 1, three transport vehicles 1 are configured as a first group, two transport vehicles 1 are configured as a second group, and one transport vehicle 1 is configured as a spare group;

[0053] Step 2: Drive the transport vehicle 1 of the first group to the bottom of the bridge to be demolished, park one transport vehicle 1 of the first group under the center of the bridge to be demolished, and the other two transport vehicles 1 of the first group are symmetrically arranged on both sides of the transport vehicle 1 located in the center;

[0054] Step 3: drive the scissor-type hydraulic lift 3 of the transport vehicle 1 of the first group to raise the movable rod 201 to abut against the box beam of the bridge to be demolished, and at the same time drive the hydraulic cylinder 202 of the transport vehicle 1 of the first group to rise to abut against the box beam of the bridge to be demolished;

[0055] Step 4: cutting the box beams of the bridge to be demolished from both sides thereof, so that part of the box beams are cut and separated and carried by the transport vehicle 1 of the first group;

[0056] Step 5: driving the scissor-type hydraulic lift 3 of the transport vehicle 1 of the first group to make the movable rod 201 descend once, and driving the hydraulic cylinder 202 of the transport vehicle 1 of the first group to descend once;

[0057] Step 6: Drive the transport vehicle 1 of the second group to the bottom of the partial box girder, and insert a transport vehicle 1 of the second group between two adjacent transport vehicles 1 of the first group;

[0058] Step 7: drive the scissor-type hydraulic lift 3 of the transport vehicle 1 of the second group to raise the movable rod 201 to abut against part of the box beam, and at the same time drive the hydraulic cylinder 202 of the transport vehicle 1 of the second group to rise to abut against part of the box beam, after the transport vehicle 1 of the second group carries part of the box beam, drive the scissor-type hydraulic lift 3 of the transport vehicle 1 of the first group to lower the movable rod 201, and at the same time drive the hydraulic cylinder 202 of the transport vehicle 1 of the first group to lower, and then drive the transport vehicle 1 of the first group to leave from under the part of the box beam;

[0059] Step 8: driving the scissor-type hydraulic lift 3 of the transport vehicle 1 of the second group to make the movable rod 201 descend for the second time, and driving the hydraulic cylinder 202 of the transport vehicle 1 of the second group to descend for the second time;

[0060] Step 9: driving the transport vehicle 1 of the first group to the bottom of a part of the box beam, the parking position of the transport vehicle 1 of the first group is the same as the parking position of the vehicle that is lowered once;

[0061] Step 10: drive the scissor-type hydraulic lift 3 of the transport vehicle 1 of the first group to raise the movable rod 201 to abut against part of the box beam, and at the same time drive the hydraulic cylinder 202 of the transport vehicle 1 of the first group to rise to abut against part of the box beam, after the transport vehicle 1 of the first group carries part of the box beam, drive the scissor-type hydraulic lift 3 of the transport vehicle 1 of the second group to lower the movable rod 201, and at the same time drive the hydraulic cylinder 202 of the transport vehicle 1 of the second group to lower, and then drive the transport vehicle 1 of the second group to leave from under the part of the box beam;

[0062] Step 11: drive the scissor-type hydraulic lift 3 of the first group of transport vehicles 1 to lower the movable rod 201 three times, and at the same time drive the hydraulic cylinder 202 of the first group of transport vehicles 1 to lower three times until part of the box beam drops to a predetermined height.

[0063] During the descent process, the purpose of using the first group of transport vehicles 1 and the second group of transport vehicles 1 to carry the load in turns is to detect and adjust the position of the supporting equipment and the bridge in each step of the operation, promptly discover and deal with possible problems, improve the safety of the entire operation process, and avoid accidents; avoid excessive stress at a single position for a long time, thereby reducing the loss and potential damage risk of equipment and bridge structures; through multiple small descent operations rather than a large descent, the descent process of the box girder can be controlled more accurately to ensure that the box girder finally reaches the predetermined position accurately.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A material transport device, comprising a transport vehicle and a carrying bracket arranged on the transport vehicle, characterized in that: The carrying bracket comprises two movable rods and two hydraulic cylinders which are alternately arranged at four corners in sequence, the movable rod is configured to perform lifting movement in the vertical direction, the carrying bracket also comprises a spring, a linkage and a clamping mechanism, the spring is arranged on the movement path of the movable rod, the linkage is connected to the clamping mechanism, when the movable rod descends to a predetermined position, the movable rod squeezes the spring and triggers the linkage to drive the clamping mechanism to intermittently clamp the movable rod in the horizontal direction; It also includes a base, wherein a first groove is provided at the center of the top surface of the base and is used to accommodate part of the movable rod, the spring is arranged in the first groove, and an annular protrusion is provided on the side of the movable rod and abuts against the spring; The movable rod comprises a top cover, a main rod and a support rod, wherein the main rod and the support rod are arranged in parallel and are respectively connected to the top cover, the base is provided with a second groove, the second groove is arranged on the side of the first groove, the main rod is arranged in the first groove, and the support rod is arranged in the second groove; The linkage member is arranged in the second groove, and the linkage member includes a rack, a main gear, a large gear, a pinion and a limit plate. The rack is arranged below the support rod, and the inner wall of the second groove is connected with a rotating shaft that rotates with it. The main gear and the large gear are coaxially connected to the rotating shaft, and the rack is meshed with the main gear for transmission. The pinion is arranged on the side of the large gear and meshed with it for transmission. The limit plate is provided with a square receiving groove arranged in the vertical direction, and a roller is coaxially connected to the pinion, and the roller is arranged in the square receiving groove, and the clamping mechanism is connected to the limit plate; The clamping mechanism includes a cross bar and a clamping block arranged in a horizontal direction. The base is provided with a channel connecting the first groove and the second groove to install the cross bar. One end of the cross bar is arranged in the first groove and connected to the clamping block. The other end of the cross bar is arranged in the second groove and connected to the limit plate. A rectangular hole is provided on the cross bar. The channel is connected to the limit column, and the limit column is arranged in the rectangular hole.

2. A material transport device according to claim 1, characterized in that: The carrying bracket also includes a scissor-type hydraulic lift, which is arranged on the transport vehicle and connected to the movable rod and the hydraulic cylinder.

3. A method of use, applied to a material transport device as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: Prepare at least six transport vehicles and install a carrying bracket on each transport vehicle. Three transport vehicles are configured as the first group, two transport vehicles are configured as the second group, and one transport vehicle is configured as the spare group; Step 2: Drive the transport vehicle of the first group to the bottom of the bridge to be demolished, park one transport vehicle of the first group under the center of the bridge to be demolished, and the other two transport vehicles of the first group are symmetrically arranged on both sides of the transport vehicle located in the center; Step 3: driving the scissor-type hydraulic lift of the transport vehicle of the first group to raise the movable rod to abut against the box beam of the bridge to be demolished, and at the same time driving the hydraulic cylinder of the transport vehicle of the first group to rise to abut against the box beam of the bridge to be demolished; Step 4: Cut the box beams of the bridge to be demolished from both sides, so that part of the box beams are cut and separated and carried by the transport vehicle of the first group; Step 5: driving the scissor-type hydraulic lift of the transport vehicle of the first group to lower the movable rod once, and driving the hydraulic cylinder of the transport vehicle of the first group to lower once; Step 6: Drive the transport vehicle of the second group to the bottom of the partial box girder, and insert a transport vehicle of the second group between two adjacent transport vehicles of the first group; Step 7: drive the scissor-type hydraulic lift of the transport vehicle of the second group to raise the movable rod to abut against part of the box beam, and at the same time drive the hydraulic cylinder of the transport vehicle of the second group to rise to abut against part of the box beam, after the transport vehicle of the second group carries part of the box beam, drive the scissor-type hydraulic lift of the transport vehicle of the first group to lower the movable rod, and at the same time drive the hydraulic cylinder of the transport vehicle of the first group to lower, and then drive the transport vehicle of the first group to leave from under the part of the box beam; Step 8: driving the scissor-type hydraulic lift of the transport vehicle of the second group to make the movable rod descend for the second time, and at the same time driving the hydraulic cylinder of the transport vehicle of the second group to descend for the second time; Step 9: Drive the transport vehicle of the first group to the bottom of the partial box beam, and the parking position of the transport vehicle of the first group is the same as the parking position of the vehicle that is lowered once; Step 10: driving the scissor-type hydraulic lift of the transport vehicle of the first group to raise the movable rod to abut against part of the box beam, and driving the hydraulic cylinder of the transport vehicle of the first group to rise to abut against part of the box beam, after the transport vehicle of the first group carries part of the box beam, driving the scissor-type hydraulic lift of the transport vehicle of the second group to lower the movable rod, and driving the hydraulic cylinder of the transport vehicle of the second group to lower, and then driving the transport vehicle of the second group to leave from under the part of the box beam; Step 11: Drive the scissor-type hydraulic lift of the first group of transport vehicles to lower the movable rod three times, and at the same time drive the hydraulic cylinder of the first group of transport vehicles to lower three times until part of the box beam drops to a predetermined height.

4. A method of use according to claim 3, characterized in that: During a descent, three transport vehicles are used to adjust part of the box girder to keep it balanced.

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