Large-tonnage folding arm type lorry-mounted crane

Abstract

The invention discloses a large-tonnage folding arm type lorry-mounted crane, and belongs to the technical field of cranes, the large-tonnage folding arm type lorry-mounted crane comprises a base, a folding arm, a telescopic assembly, a fixed pulley and a lifting hook, the lifting hook is connected with a steel wire rope, and the steel wire rope bypasses the fixed pulley on the folding arm and is connected with an external winch; the rope bending assembly is arranged on the folding arm and is used for enabling a steel wire rope section between the fixed pulley and the lifting hook to be in a bent state; and the releasing assembly is arranged on the rope bending assembly and is used for enabling the rope bending assembly to be invalid when the lifting hook moves upwards to a fixed position. In the invention, the steel wire rope is bent by the rope bending assembly, and when the top rushing phenomenon occurs, the release assembly triggers the action, so that the rope bending assembly loses efficacy, the bent part of the steel wire rope recovers to a straight line state, the lower end of the steel wire rope moves downwards, and the upward movement amplitude generated by inertia is reduced; and the damage to the crane and the articles in the jacking process is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of cranes, and particularly relates to a large-tonnage folding boom truck-mounted crane. Background Art

[0002] A crane refers to a multi-action hoisting machine that vertically lifts and horizontally transports heavy objects within a certain range. It is also known as an overhead crane, a bridge crane, or a hoist. The main features of a tyre crane are: its driving cab and hoisting control cab are combined into one, and it is evolved from a crawler crane (crawler hoist). The crawler and walking support parts of the walking mechanism are changed into a chassis with tyres, overcoming the disadvantage of the crawler plates of the crawler crane (crawler hoist) damaging the road surface. It belongs to a material handling machine. A bridge crane is a hoisting device that spans over workshops, warehouses, and yards for material hoisting. Since its two ends are located on tall concrete columns or metal brackets, it resembles a bridge. The bridge of the bridge crane runs longitudinally along the tracks laid on the two high racks on both sides, and can make full use of the space under the bridge to hoist materials without being hindered by ground equipment. It is the most widely used and most numerous type of hoisting machine. The working characteristic of the hoisting equipment is intermittent movement, that is, in a working cycle, the corresponding mechanisms for actions such as material taking, transporting, and unloading work alternately. The development and use of cranes in the market are becoming more and more extensive. Due to accidents often occurring during hoisting without outriggers and hoisting while driving, the driving speed is also faster than that of a crawler crane (crawler hoist); the operation is stable, the lifting capacity is large, it can hoist and walk within a specific range, but it is necessary to ensure that the road surface is flat and solid, the tyre pressure meets the requirements, and the lifted height from the ground shall not exceed 50 CM; it is prohibited to walk for a long distance with a load. To ensure operation safety, basically no hoisting operation is allowed without outriggers in China. The wire rope varieties used in supporting cranes include phosphating coated wire ropes, galvanized wire ropes, and bright wire ropes.

[0003] In the prior art, such as a folding boom truck-mounted crane disclosed in the Chinese utility model patent publication No. CN205204682U, which belongs to the technical field of truck-mounted cranes; the technical problem to be solved is to provide a gantry folding boom truck-mounted crane with a simple structure, high reliability, and convenient installation and maintenance; the technical solution adopted is: the bottom end of the column is offset and installed on one side of the base assembly through a slewing drive, the hydraulic oil tank is fixedly installed on the other side of the base assembly, the hydraulic motor is fixedly installed on one side of the slewing drive, the upper end of the column is hinged to one end of the boom assembly, the other end of the boom assembly is hinged to one end of the jib assembly, a hook assembly is installed at the other end of the jib assembly, the cylinder body of the boom cylinder is hinged to the bottom of the column and the end of its piston rod is hinged to the middle of the boom assembly, the cylinder body of the jib cylinder is hinged to the middle of the boom assembly and the end of its piston rod is hinged to the jib assembly, and the electrical system is controlled by a wired remote controller; the present invention adopts column offset, integral slewing, and gantry folding, which simplifies the structure of the crane and improves its reliability.

[0004] When the folding boom crane in the above-mentioned prior art hoists an object, it mainly uses a winch to lift the object, that is, through the cooperation of the winch and the steel wire rope to lift the object. When the winch lifts the object, it is necessary to control the lifting height of the steel wire rope to prevent the phenomenon of over-running. However, the existing cranes mainly use sensors to prevent over-running. In this case, since the steel wire rope has a certain inertia when over-running, especially when lifting relatively light objects, even if the sensor can detect and generate an induction signal, there is still an over-running phenomenon under the action of inertia. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a large-tonnage folding boom truck-mounted crane.

[0006] The technical solution adopted to solve the above technical problem is: a large-tonnage folding boom truck-mounted crane, comprising: A base installed on an external moving vehicle body, a folding boom is installed on the base, and the folding boom is driven to move up and down by a telescopic assembly installed on the base; A fixed pulley installed on the folding boom, a hook is provided below one of the fixed pulleys far from the base, a steel wire rope is connected to the hook, and the steel wire rope bypasses the fixed pulley on the folding boom and is connected to an external winch; A wire bending assembly installed on the folding boom, and the wire bending assembly is used to make the steel wire rope section between the fixed pulley and the hook in a bent state; A release assembly provided on the wire bending assembly, and the release assembly is used to make the wire bending assembly ineffective when the hook moves upward to a fixed position.

[0007] Through the above technical solution, the wire bending assembly bends the steel wire rope. When the over-running phenomenon occurs, the release assembly will trigger an action, thereby making the wire bending assembly ineffective, and then making the bent part of the steel wire rope return to a straight state, so that the lower end of the steel wire rope moves downward, reducing the upward movement amplitude due to inertia, and avoiding damage to the crane and the object during over-running.

[0008] Further, the folding boom includes a main folding boom hinged to the base, a main telescopic boom is hinged to one end of the main folding boom far from the base, and a secondary telescopic boom is telescopically inserted into the main telescopic boom.

[0009] Through the above technical solution, the secondary telescopic boom telescopically slides in the main telescopic boom, so that the hook can move. In addition, the main folding boom can rotate on the base, and the main telescopic boom can rotate on the main folding boom, so that the hook can move up and down.

[0010] Furthermore, the telescopic assembly includes a main driving oil cylinder hingedly installed on the base, the end of the telescopic rod of the main driving oil cylinder is hingedly installed on the main folding arm, a main telescopic oil cylinder is installed on the main telescopic arm, the end of the telescopic rod of the main telescopic oil cylinder is connected to the auxiliary telescopic arm, a secondary driving oil cylinder is hingedly installed on the main folding arm, and the end of the telescopic rod of the secondary driving oil cylinder is hingedly connected to the main telescopic arm.

[0011] Through the above technical solution, the main driving oil cylinder drives the main folding arm to swing up and down along the hinge with the base, and in addition, the secondary driving oil cylinder drives the main telescopic arm to swing, so as to realize the up and down movement of the hook.

[0012] Furthermore, a plurality of the auxiliary telescopic arms are provided, and the plurality of auxiliary telescopic arms are telescopically inserted and connected in sequence. An auxiliary telescopic oil cylinder is installed on the auxiliary telescopic arm, and the end of the telescopic rod of the auxiliary telescopic oil cylinder is connected to an adjacent auxiliary telescopic arm.

[0013] Through the above technical solution, the auxiliary telescopic oil cylinder drives the auxiliary telescopic arm to move linearly, so that the hook can move linearly.

[0014] Furthermore, a connecting rod is fixedly connected to the lower end of the steel wire rope. The lower end of the connecting rod is rotatably connected to a connecting seat. The lower end of the connecting seat is hingedly installed with an adjusting seat. The upper end of the hook is rotatably connected to the bottom of the adjusting seat. A rotation adjusting assembly for driving the hook to rotate in the horizontal plane is provided on the adjusting seat.

[0015] Through the above technical solution, the rotation adjusting assembly drives the hook to rotate in the horizontal plane, so that the hook can more conveniently hook an object, facilitating quick hoisting operations.

[0016] Furthermore, the rotation adjusting assembly includes a motor vertically installed on the inner top wall of the adjusting seat. The upper end of the hook is fixedly connected with a rotating part, and the rotating part is drivingly connected to the motor shaft of the motor.

[0017] Through the above technical solution, the motor shaft of the motor rotates, thereby driving the rotating part to rotate. When the rotating part rotates, it can drive the upper end of the hook to rotate, so that the hook can rotate.

[0018] Further, the bent rope assembly includes a fixed seat fixedly connected to the folding arm. A fixed cylinder extending downward is fixedly connected to the fixed seat. A fixed arm is fixedly connected to the outer wall of the lower end of the fixed cylinder. One end of the fixed arm away from the fixed cylinder extends downward and horizontally penetrates through a sliding arm. The sliding arm is freely slidable on the fixed arm. A bent rope wheel is rotatably connected to one end of the sliding arm away from the fixed arm. The steel wire rope bypasses the bent rope wheel. A pressing unit is provided on the fixed cylinder. The pressing unit is used to drive the sliding arm to move towards the steel wire rope, so that the bent rope wheel generates a lateral pressing force on the steel wire rope, thereby making the steel wire rope in a bent state.

[0019] Through the above technical solution, the pressing unit drives the sliding arm to move away from the fixed cylinder, thereby causing the bent rope wheel to squeeze the steel wire rope, making the steel wire rope in a bent state.

[0020] Further, the pressing unit includes a rack bar fixedly connected to one end of the sliding arm away from the bent rope wheel. A rotating part is rotatably sleeved on the lower end of the fixed cylinder. A gear part is provided on the periphery of the rotating part. The gear part is in an external meshing state with the rack bar. A sliding rod is telescopically inserted and installed in the fixed cylinder. A sliding hole for the sliding rod to freely pass through is provided in the fixed cylinder. A transmission structure is connected between the sliding rod and the rotating part. The transmission structure is used to drive the circumferential rotation of the rotating part when the sliding rod moves vertically. The periphery of the sliding rod is in a key connection with the wall of the sliding hole.

[0021] Through the above technical solution, the sliding rod moves downward, and the transmission structure can drive the rotating part to rotate. When the rotating part rotates, it will drive the sliding arm to move away from the fixed cylinder, thereby causing the bent rope wheel to squeeze the steel wire rope, so that the steel wire rope is in a bent shape.

[0022] Further, the release assembly includes a floating arm horizontally fixedly connected to the lower end of the sliding rod. A rope passing hole for the steel wire rope to freely pass through is provided on the floating arm. A pressing cylinder is vertically installed on the fixed arm. The end of the cylinder rod of the pressing cylinder abuts against the upper surface of the floating arm. The floating arm is used in cooperation with the connecting rod. A guide wheel is installed on the upper surface of the floating arm. After the steel wire rope bypasses the guide wheel, it passes out through the rope passing hole.

[0023] Through the above technical solution, the pressing cylinder generates a downward pressing force on the floating arm, so that the sliding rod cannot move upward. In this way, the transmission structure cannot drive the rotating part to rotate, and the bent rope wheel is in a state of squeezing the steel wire rope, and the steel wire rope is also in a bent state.

[0024] Further, a return spring is vertically installed in the sliding hole, and two ends of the elastic force direction of the return spring elastically abut against the upper end surface of the sliding rod and the inner top wall of the sliding hole respectively.

[0025] Through the above technical solution, the return spring has a downward elastic abutting force on the sliding rod, so that when the hook is in the no-load condition and the cylinder rod of the abutting cylinder is separated from the abutting state with the floating arm, the sliding rod will move downward, and the rotating part will rotate, and then the sliding arm will move away from the fixed cylinder, so that the bending rope wheel can squeeze the steel wire rope.

[0026] The beneficial effects of the present invention are as follows: 1. In the present invention, the bending rope assembly bends the steel wire rope. When the top collision phenomenon occurs, the release assembly will trigger an action, and then the bending rope assembly will fail, and then the bent part of the steel wire rope will return to a straight state, so that the lower end of the steel wire rope will move downward, reducing the upward movement amplitude caused by inertia, and avoiding damage to the crane and the goods during top collision; 2. In the present invention, the abutting cylinder generates a downward squeezing force on the floating arm, so that the sliding rod cannot move upward, so that the transmission structure cannot drive the rotating part to rotate, and the bending rope wheel is in a squeezing state on the steel wire rope, and the steel wire rope is in a bent state at the same time; 3. In the present invention, the return spring has a downward elastic abutting force on the sliding rod, so that when the hook is in the no-load condition and the cylinder rod of the abutting cylinder is separated from the abutting state with the floating arm, the sliding rod will move downward, and the rotating part will rotate, and then the sliding arm will move away from the fixed cylinder, so that the bending rope wheel can squeeze the steel wire rope. Description of the Drawings

[0027] Figure 1 is the overall structural schematic diagram of a large-tonnage folding boom truck-mounted crane in an embodiment of the present invention; Figure 2 is Figure 1 the enlarged schematic diagram of the partial structure at A in Figure 3 is Figure 1 the schematic diagram of the positional relationship from another perspective in Figure 4 is the schematic diagram of the positional relationship after the adjustment seat, the hook and the connecting seat are assembled in the present invention; Figure 5 is the schematic diagram of the positional relationship after the fixed cylinder, the fixed arm and the floating arm are assembled in the present invention; Figure 6 is Figure 5 the schematic diagram of the positional relationship after a part of the structure in Figure 7 is Figure 6 the enlarged schematic diagram of the partial structure at B in Figure 8 It is a schematic structural diagram of the rotating part in the present invention.

[0028] Reference numerals: 1, base; 2, main driving oil cylinder; 3, auxiliary driving oil cylinder; 4, main folding arm; 5, main telescopic arm; 6, main telescopic oil cylinder; 7, auxiliary telescopic oil cylinder; 8, auxiliary telescopic arm; 9, fixed pulley; 10, steel wire rope; 11, return spring; 12, hook; 13, adjusting seat; 14, rotating part; 15, motor; 16, connecting seat; 17, connecting rod; 18, fixed seat; 19, fixed cylinder; 20, pressing cylinder; 21, fixed arm; 22, rope bending pulley; 23, sliding arm; 24, guide pulley; 25, rack bar; 26, floating arm; 27, sliding rod; 28, spiral rolling groove; 29, gear part; 30, rack section; 31, perforation; 32, ball; 33, rotating part; 34, sliding hole. Detailed implementation manners

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] As Figures 1-8 shown, this embodiment provides a large-tonnage folding boom truck crane, including a base 1 installed on an external moving vehicle body. Specifically, the base 1 can be connected to the moving vehicle body by screws or by welding, so that the base 1 can move along with the vehicle. A main folding arm 4 is hingedly installed on the base 1. One end of the main folding arm 4 away from the base 1 is hingedly installed with a main telescopic arm 5. A plurality of auxiliary telescopic arms 8 are telescopically inserted and installed on the main telescopic arm 5. Adjacent two sections of the auxiliary telescopic arms 8 are telescopically inserted and connected. That is, one section of the auxiliary telescopic arm 8 away from the main telescopic arm 5 is telescopically inserted into the adjacent section of the auxiliary telescopic arm 8 close to the main telescopic arm 5, so that the plurality of auxiliary telescopic arms 8 can be telescoped. The main folding arm 4, the main telescopic arm 5 and the plurality of auxiliary telescopic arms 8 are combined into a folding boom; A main driving oil cylinder 2 is hingedly installed on a base 1. The end of the telescopic rod of the main driving oil cylinder 2 is hingedly installed on a main folding arm 4. A main telescopic arm 5 is provided with a main telescopic oil cylinder 6. The end of the telescopic rod of the main telescopic oil cylinder 6 is connected to a secondary telescopic arm 8. A secondary driving oil cylinder 3 is hingedly installed on the main folding arm 4. The end of the telescopic rod of the secondary driving oil cylinder 3 is hinged to the main telescopic arm 5. When the telescopic rod of the main driving oil cylinder 2 extends, it will drive the main folding arm 4 to swing up and down along the hinge with the base 1. When the telescopic rod of the secondary driving oil cylinder 3 extends, it will further drive the main telescopic arm 5 to swing up and down along the hinge with the main folding arm 4. The secondary telescopic arm 8 is provided with a secondary telescopic oil cylinder 7. The end of the telescopic rod of the secondary telescopic oil cylinder 7 is connected to an adjacent secondary telescopic arm 8. When the telescopic rod of the secondary telescopic oil cylinder 7 extends, it will drive a secondary telescopic arm 8 to telescopically slide within another secondary telescopic arm 8; Fixed pulleys 9 are respectively installed on the main telescopic arm 5 and multiple secondary telescopic arms 8. A steel wire rope 10 is wound around the multiple fixed pulleys 9. One end of the steel wire rope 10 is connected to a winch on a moving vehicle body. The winch can pull the steel wire rope 10 to move. The end of the steel wire rope 10 away from the base 1 is fixedly connected to a connecting rod 17. The lower end of the connecting rod 17 is rotatably connected to a connecting seat 16. The lower end of the connecting seat 16 is hingedly installed with an adjusting seat 13. A hook 12 is installed at the bottom of the adjusting seat 13. Specifically, the upper end of the hook 12 is cylindrical and is rotatably connected to the bottom of the adjusting seat 13 through a mounted bearing. The adjusting seat 13 is hollow inside, and a motor 15 is vertically installed on the top wall of the inner cavity of the adjusting seat 13. The upper end of the hook 12 is coaxially fixedly connected with a rotating part 14. The rotating part 14 is drivingly connected to the motor shaft of the motor 15. When the motor shaft of the motor 15 rotates, it will drive the rotating part 14 to rotate, and thus the hook 12 can rotate around the axis of its upper end on a horizontal plane, thereby changing the orientation of the hook 12; A fixing seat 18 is welded on a secondary telescopic arm 8 away from the base 1. A fixing cylinder 19 extending downward is fixedly connected to the fixing seat 18. A fixing arm 21 is fixedly connected to the outer wall of the lower end of the fixing cylinder 19. One end of the fixing arm 21 away from the fixing cylinder 19 extends downward and horizontally penetrates a sliding arm 23. The sliding arm 23 freely slides on the fixing arm 21. One end of the sliding arm 23 away from the fixing arm 21 is rotatably connected to a bending pulley 22. The steel wire rope 10 bypasses the bending pulley 22; One end of the sliding arm 23 away from the bent rope wheel 22 is fixedly connected with a rack bar 25. The lower end of the fixed cylinder 19 is rotatably sleeved with a rotating part 33. A gear part 29 is provided on the periphery of the rotating part 33. The gear part 29 is in an external meshing state with the rack bar 25. Specifically, a rack section 30 is provided on the outer wall of the rack bar 25, and the rack section 30 is in an external meshing state with the gear part 29. A sliding rod 27 is telescopically inserted and installed in the fixed cylinder 19. A sliding hole 34 for the sliding rod 27 to pass through freely is provided in the fixed cylinder 19. A transmission structure is provided between the sliding rod 27 and the rotating part 33. The transmission structure is used to drive the circumferential rotation of the rotating part 33 when the sliding rod 27 moves vertically. The periphery of the sliding rod 27 is in a key connection with the inner cavity wall of the fixed cylinder 19, and a through hole 31 for the sliding rod 27 to pass through freely is provided on the end face of the rotating part 33. Specifically, the transmission structure includes two balls 32 rotatably embedded on the inner wall of the through hole 31 of the rotating part 33, and the two balls 32 are symmetrically arranged along the axial direction of the rotating part 33. A spiral rolling groove 28 for the balls 32 to engage is provided on the periphery of the sliding rod 27. Since the periphery of the sliding rod 27 is in a key connection with the inner wall of the sliding hole 34, when the sliding rod 27 is telescopically inserted in the sliding hole 34 of the fixed cylinder 19, the sliding rod 27 will not rotate circumferentially, and the balls 32 will roll in the spiral rolling groove 28, causing the rotating part 33 to rotate; A floating arm 26 is horizontally fixedly connected to the lower end of the sliding rod 27. A rope passing hole for the steel wire rope 10 to pass through freely is provided on the floating arm 26. A pressing cylinder 20 is vertically installed on the fixed arm 21. The end of the cylinder rod of the pressing cylinder 20 abuts against the upper surface of the floating arm 26. The floating arm 26 is used in cooperation with the connecting rod 17. A guide wheel 24 is installed on the upper surface of the floating arm 26. After the steel wire rope 10 bypasses the guide wheel 24, it passes out through the rope passing hole. A return spring 11 is vertically installed in the sliding hole 34. The two ends of the elastic force direction of the return spring 11 elastically abut against the upper end face of the sliding rod 27 and the inner top wall of the sliding hole 34 respectively. In addition, an induction block (not shown in the figure) is provided on the connecting seat 16, and a sensor (not shown in the figure) is provided on the floating arm 26. The sensor is used in cooperation with the induction block. When the induction block enters the induction range of the sensor, it indicates that the hook 12 may have a topping phenomenon. The sensor generates an induction signal and transmits it to the external control cabinet, and the external control cabinet controls the external hoist to stop working to prevent the steel wire rope 10 from continuing to pull the hook 12 upward.

[0031] The working principle of this embodiment is as follows: When the hook 12 is in the no-load state, the cylinder rod of the pressing cylinder 20 is in the retracted state, that is, the end of the cylinder rod of the pressing cylinder 20 is separated from the state of abutting against the surface of the floating arm 26. At this time, the return spring 11 has a downward elastic abutting force on the sliding rod 27, so that the sliding rod 27 moves downward. It should be noted that the return spring 11 in this embodiment is selected by those skilled in the art, so that the elastic abutting force of the return spring 11 on the sliding rod 27 is greater than the gravity of components such as the connecting seat 16, the hook 12, the motor 15, and the adjusting seat 13. Therefore, it can be ensured that when the return spring 11 elongates downward, the sliding rod 27 can overcome the gravity of components such as the connecting seat 16, the hook 12, the motor 15, and the adjusting seat 13 and move downward. When the sliding rod 27 moves downward, the ball 32 rolls in the spiral rolling groove 28. Since the periphery of the sliding rod 27 is in key connection with the inner wall of the sliding hole 34, when the sliding rod 27 telescopically inserts in the sliding hole 34 of the fixed cylinder 19, the sliding rod 27 will not generate circumferential rotation, and the ball 32 will roll in the spiral rolling groove 28, causing the rotating part 33 to generate a rotational motion. When the rotating part 33 rotates, the gear part 29 on the rotating part 33 will be meshed with the rack section 30 on the rack bar 25, so that the rack bar 25 can drive the sliding arm 23 to move away from the fixed cylinder 19, and the bending rope wheel 22 presses the steel wire rope 10 between the fixed pulley 9 and the hook 12, making the steel wire rope 10 in a bent shape. This is equivalent to increasing the length of the steel wire rope 10 between the fixed pulley 9 (one of the fixed pulleys 9 away from the base 1) and the hook 12; After the steel wire rope 10 is in a bent state, the pressing cylinder 20 is started, the cylinder rod of the pressing cylinder 20 elongates, and the end of the cylinder rod of the pressing cylinder 20 abuts against the floating arm 26 to prevent the floating arm 26 from moving upward. In this way, when the hook 12 hoists an object, due to the increase in gravity, when the steel wire rope 10 generates a lateral force on the bending rope wheel 22, the situation where the sliding arm 23 moves in the reverse direction will not occur; When hoisting an object, first, the telescopic rod of the main driving oil cylinder 2 extends, driving the main folding arm 4 to swing up and down around the hinge with the base 1. The telescopic rod of the auxiliary driving oil cylinder 3 extends, further driving the main telescopic arm 5 to swing up and down around the hinge with the main folding arm 4. An auxiliary telescopic oil cylinder 7 is installed on the auxiliary telescopic arm 8, and the end of the telescopic rod of the auxiliary telescopic oil cylinder 7 is connected to an adjacent auxiliary telescopic arm 8. When the telescopic rod of the auxiliary telescopic oil cylinder 7 extends, it will drive an auxiliary telescopic arm 8 to slide telescopically within another auxiliary telescopic arm 8, so that the hook 12 can move to the object to be hoisted. Then, by starting the motor 15, the motor shaft of the motor 15 rotates, enabling the orientation of the hook 12 to change, and thus enabling the hook 12 to hook the object. In this way, there is no need to manually hang the object on the hook 12. Then, through the extension and retraction of the main driving oil cylinder 2, the auxiliary driving oil cylinder 3, the main telescopic oil cylinder 6, and the auxiliary telescopic oil cylinder 7, the hoisting operation of the hook 12 on the object is realized; If the top - hitting phenomenon occurs, the connecting rod 17 moves upward and makes the induction block move upward, thus entering the sensing range of the sensor. The sensor generates an induction signal and transmits it to the external control cabinet. The external control cabinet controls the external hoist to stop working, preventing the steel wire rope 10 from continuing to pull the hook 12 upward. At the same time, the control cabinet controls the tightening cylinder 20 to start. The cylinder rod of the tightening cylinder 20 retracts and disengages from the floating arm 26. At the same time, if the amplitude of the connecting rod 17 hitting the top is large, the connecting rod 17 will contact the floating arm 26 and make the floating arm 26 move upward. When the floating arm 26 moves upward, it will drive the sliding rod 27 to move upward. Since the periphery of the sliding rod 27 is in key connection with the inner wall of the sliding hole 34, when the sliding rod 27 telescopically inserts into the sliding hole 34 of the fixed cylinder 19, the sliding rod 27 will not rotate circumferentially. The ball 32 will roll in the spiral rolling groove 28, making the rotating part 33 generate a rotational movement. When the rotating part 33 rotates, the gear part 29 on the rotating part 33 will engage with the rack section 30 on the rack rod 25, enabling the rack rod 25 to drive the sliding arm 23 to move towards the fixed cylinder 19, and further enabling the rope - bending wheel 22 to move towards the fixed cylinder 19. In this way, the squeezing state of the rope - bending wheel 22 on the steel wire rope 10 disappears, and the originally bent part of the steel wire rope 10 will be naturally vertical, which is equivalent to increasing the longitudinal distance between the hook 12 and the fixed pulley 9, thereby reducing the distance between the hook 12 and the fixed pulley 9. The potential energy of the hook 12 hitting the top will increase, and thus reducing the distance of inertial movement during top - hitting. Compared with the existing technology that simply uses sensors for detection, it can largely avoid the damage caused by top - hitting. In addition, during the upward movement of the sliding rod 27, it will squeeze the return spring 11, making the return spring 11 generate elastic potential energy, which can buffer the top - hitting of the hook 12; After the anti-overhead protection operation, since the wire rope 10 no longer pulls the hook 12, and the hook 12 and the item are in a static state, at this time, start the winch. The winch slowly pays out the wire rope 10 downward, so that the hook 12 drives the item to move downward. When moving downward, the floating arm 26 will gradually move away from the connecting rod 17. Then, through the coordinated actions of the main drive cylinder 2, the auxiliary drive cylinder 3, the main telescopic cylinder 6, and the auxiliary telescopic cylinder 7, the item is placed in the lifting area and the hook 12 is disengaged from the item. At this time, the hook 12 is in an unloaded state. Then, start the clamping cylinder 20. The cylinder rod of the clamping cylinder 20 extends, and the end of the cylinder rod of the clamping cylinder 20 gradually approaches the floating arm 26. After contacting the floating arm 26, the cylinder rod of the clamping cylinder 20 continues to extend, thereby driving the floating arm 26 to move downward. When the floating arm 26 moves downward, it will drive the sliding rod 27 to move downward. When the sliding rod 27 slides downward in the sliding hole 34, it will cause the ball 32 to roll in the spiral rolling groove 28. As mentioned before, the periphery of the sliding rod 27 is key-connected to the inner wall of the sliding hole 34, that is, the sliding rod 27 can only be in a sliding motion state in the sliding hole 34. Therefore, when the sliding rod 27 moves downward, it will cause the ball 32 to squeeze the inner wall of the spiral rolling groove 28, thereby causing the rotating part 33 to rotate. When the rotating part 33 rotates, the rack section 30 on the rack bar 25 will be in a meshing transmission state with the gear part 29 on the rotating part 33, thereby causing the rack bar 25 to move horizontally. When the rack bar 25 moves horizontally, it will cause the wire rope pulley 22 to move away from the fixed cylinder 19, thereby causing the wire rope pulley 22 to squeeze the wire rope 10 again, making the wire rope 10 bend again. In addition, the release of the elastic potential energy of the return spring 11 can also drive the sliding rod 27 to move downward, which helps the floating arm 26 to move downward and reset quickly, and then perform the next anti-overhead operation.

[0032] The above is only the preferred embodiment of the present invention, and is not used to limit the protection scope of the present invention.

Claims

1. A large-tonnage folding boom truck-mounted crane, characterized in that, Comprising: A base (1) installed on an external moving vehicle body, a folding arm is installed on the base (1), and the folding arm is driven to move up and down by a telescopic assembly installed on the base (1); A fixed pulley (9) installed on the folding arm, a hook (12) is provided below one of the fixed pulleys (9) far from the base (1), a steel wire rope (10) is connected to the hook (12), and the steel wire rope (10) bypasses the fixed pulley (9) on the folding arm and is connected to an external hoist; A bent wire rope assembly installed on the folding arm, and the bent wire rope assembly is used to make the section of the steel wire rope (10) between the fixed pulley (9) and the hook (12) in a bent state; A release assembly provided on the bent wire rope assembly, and the release assembly is used to make the bent wire rope assembly ineffective when the hook (12) moves upward to a fixed position; 2. The telescopic crane according to claim 1, wherein The folding arm includes a main folding arm (4) hinged to the base (1), a main telescopic arm (5) is hinged to one end of the main folding arm (4) far from the base (1), and a secondary telescopic arm (8) is telescopically inserted into the main telescopic arm (5); 3. The articulated boom truck crane according to claim 2, wherein, The telescopic assembly includes a main driving oil cylinder (2) hinged to the base (1), the end of the telescopic rod of the main driving oil cylinder (2) is hinged to the main folding arm (4), a main telescopic oil cylinder (6) is installed on the main telescopic arm (5), the end of the telescopic rod of the main telescopic oil cylinder (6) is connected to the secondary telescopic arm (8), and a secondary driving oil cylinder (3) is hinged to the main folding arm (4), and the end of the telescopic rod of the secondary driving oil cylinder (3) is hinged to the main telescopic arm (5); 4. A large-tonnage folding boom truck crane according to claim 2, characterized in that, There are multiple secondary telescopic arms (8), and the multiple secondary telescopic arms (8) are sequentially telescopically inserted and connected. A secondary telescopic oil cylinder (7) is installed on the secondary telescopic arm (8), and the end of the telescopic rod of the secondary telescopic oil cylinder (7) is connected to an adjacent secondary telescopic arm (8); 5. A large-tonnage folding boom truck crane according to claim 1, characterized in that, A connecting rod (17) is fixedly connected to the lower end of the steel wire rope (10), a connecting seat (16) is rotatably connected to the lower end of the connecting rod (17), an adjusting seat (13) is hinged to the lower end of the connecting seat (16), the upper end of the hook (12) is rotatably connected to the bottom of the adjusting seat (13), and a rotation adjusting assembly for driving the hook (12) to rotate in a horizontal plane is provided on the adjusting seat (13); 6. A large-tonnage folding boom truck-mounted crane according to claim 5, characterized in that, The rotation adjusting assembly includes a motor (15) vertically installed on the inner top wall of the adjusting seat (13), a rotation part (14) is fixedly connected to the upper end of the hook (12), and the rotation part (14) is drivingly connected to the motor shaft of the motor (15).

7. A large-tonnage folding boom truck-mounted crane according to claim 5, characterized in that, The bent rope assembly includes a fixed seat (18) fixedly connected to the folding arm. A fixed cylinder (19) extending downward is fixedly connected to the fixed seat (18). A fixed arm (21) is fixedly connected to the outer wall of the lower end of the fixed cylinder (19). One end of the fixed arm (21) away from the fixed cylinder (19) extends downward and horizontally penetrates a sliding arm (23). The sliding arm (23) slides freely on the fixed arm (21). A bent rope wheel (22) is rotatably connected to one end of the sliding arm (23) away from the fixed arm (21). The steel wire rope (10) bypasses the bent rope wheel (22). A tightening unit is provided on the fixed cylinder (19). The tightening unit is used to drive the sliding arm (23) to move towards the steel wire rope (10), so that the bent rope wheel (22) generates a lateral extrusion force on the steel wire rope (10), thereby making the steel wire rope (10) in a bent state.

8. A large-tonnage folding boom truck crane according to claim 7, characterized in that, The tightening unit includes a rack bar (25) fixedly connected to one end of the sliding arm (23) away from the bent rope wheel (22). A rotating part (33) is rotatably sleeved on the lower end of the fixed cylinder (19). A gear part (29) is provided on the periphery of the rotating part (33). The gear part (29) is in an external meshing state with the rack bar (25). A sliding rod (27) is telescopically inserted and installed in the fixed cylinder (19). A sliding hole (34) for the sliding rod (27) to pass through freely is provided in the fixed cylinder (19). A transmission structure is connected between the sliding rod (27) and the rotating part (33). The transmission structure is used to drive the circumferential rotation of the rotating part (33) when the sliding rod (27) moves vertically. The periphery of the sliding rod (27) is in a key connection with the wall of the sliding hole (34).

9. The telescopic crane with folding boom of large tonnage according to claim 8, characterized in that, The release assembly includes a floating arm (26) horizontally fixedly connected to the lower end of the sliding rod (27). A rope passing hole for the steel wire rope (10) to pass through freely is provided on the floating arm (26). A tightening cylinder (20) is vertically installed on the fixed arm (21). The end of the cylinder rod of the tightening cylinder (20) abuts against the upper surface of the floating arm (26). The floating arm (26) is used in cooperation with the connecting rod (17). A guide wheel (24) is installed on the upper surface of the floating arm (26). After the steel wire rope (10) bypasses the guide wheel (24), it passes out through the rope passing hole.

10. A large-tonnage folding boom truck-mounted crane according to claim 9, characterized in that, A return spring (11) is vertically installed in the sliding hole (34). The two ends of the elastic force direction of the return spring (11) elastically abut against the upper end surface of the sliding rod (27) and the inner top wall of the sliding hole (34) respectively.

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