Telescopic boom extension device for truck mounted crane

Abstract

A telescopic boom extension and retracting device for a truck-mounted crane comprises a first and a second oil cylinder and a basic boom, a second-section boom, a third-section boom, a fourth-section boom and a fifth-section boom which are mutually nested and assembled. The piston rod of the first oil cylinder is connected to the rear of the basic boom, the cylinder body of the first oil cylinder is connected to the rear of the second-section boom and the piston rod of the second oil cylinder, the cylinder body of the second oil cylinder is connected to the rear of the third-section boom, a first cable structure is connected between the front of the third-section boom, the front of the fourth-section boom and the fifth-section boom, a second cable structure is connected between the second-section boom and the fourth-section boom, a third cable structure is connected between the third-section boom and the fifth-section boom, and a trigger assembly for controlling the extension and retracting action of the first and second oil cylinders is arranged between the first oil cylinder and the second oil cylinder. The two oil cylinders of the telescopic boom extension and retracting device for a truck-mounted crane of the present invention can be extended and retracted sequentially, the first oil cylinder is not affected by the eccentric force and can improve the stability of its piston rod, its working control is easy to adjust, the two oil cylinders move stably, the telescopic oil cylinder will not jump when the boom is extended and retracted, the hydraulic control is simple, and the energy consumption is low.

Description

Technical Field

[0001] The invention relates to the technical field of multi-stage oil cylinder control, in particular to a telescopic arm telescopic device of a truck-mounted crane. Background Art

[0002] At present, the telescopic mechanism of the boom of the five-section boom truck crane basically adopts the following three mechanisms:

[0003] 1. One oil cylinder drives three sets of cables and a total of four telescopic boom telescopic mechanisms. The disadvantage of this telescopic mechanism is that it is difficult to arrange the space inside the arm and there are many faults;

[0004] 2. The double cylinder controlled by the mechanical sequential telescopic valve drives two sets of cables, which drive the four-section telescopic arm telescopic mechanism. The two sets of cables used are both single cables. Since the cables are transmitted by bypassing the pulley, the force will double from the top arm. In this way, the safety factor of the four-section arm extension cable is lower than that of the five-section arm extension cable, which limits the capacity of the entire telescopic mechanism. In addition, the piston rod of the second cylinder is installed on the cylinder barrel of the first cylinder. The disadvantages of this telescopic mechanism are: (1) Because the two cylinders cannot move freely, the gap between the sleeves of each section of the arm and the height difference when the cylinder enters and exits the five-section arm will cause the cylinder to jump and cause the mechanical cylinder sequential telescopic control valve to be damaged and unable to work; (2) The force of the second cylinder is directly transmitted to the hinge between the first cylinder and the second cylinder, which will cause the first cylinder to be subjected to eccentric force and reduce the stability of the piston rod of the first cylinder;

[0005] 3. The double cylinders drive two sets of cables and drive a four-section telescopic arm telescopic mechanism. The disadvantages of this telescopic mechanism are: the four-section arm cables are rope rows, which can improve the safety factor of the four-section arm cables, but the oil circuit control is hydraulic control or electro-hydraulic control, with large energy loss and high cost, and the piston rod of the second cylinder is installed on the cylinder barrel of the first cylinder. The two cylinders cannot move freely, which will cause the two cylinders to jump during the telescopic process; the force of the second cylinder is directly transmitted to the hinge between the first cylinder and the second cylinder, which will cause the first cylinder to be subjected to eccentric force and reduce the stability of the piston rod of the first cylinder.

[0006] Therefore, how to design a telescopic arm telescopic device for a truck-mounted crane that can solve the above-mentioned technical problems is a subject that the inventor has devoted himself to studying. Summary of the invention

[0007] The purpose of the present invention is to provide a telescopic boom extension and retraction device for a truck-mounted crane, wherein two oil cylinders can be extended and retracted sequentially, the first oil cylinder is not affected by the eccentric force and the stability of its piston rod can be improved, the working control is easy to adjust, the two oil cylinders move smoothly, the telescopic oil cylinders will not jump when the boom is extended and retracted, the hydraulic control is simple, and the energy consumption is low.

[0008] In order to realize the above scheme, the present invention provides a telescopic arm extension and retraction device of a truck-mounted crane, which includes a first oil cylinder, a second oil cylinder and a basic arm, a two-section arm, a three-section arm, a four-section arm and a five-section arm that are nested and assembled with each other, the piston rod of the first oil cylinder is connected to the rear of the basic arm, the cylinder body of the first oil cylinder is connected to the rear of the two-section arm and the piston rod of the second oil cylinder, the cylinder body of the second oil cylinder is connected to the rear of the three-section arm, a first cable structure is connected between the front of the three-section arm, the four-section arm and the five-section arm, a second cable structure is connected between the two-section arm and the four-section arm, a third cable structure is connected between the three-section arm and the five-section arm, and a trigger component for controlling the extension and retraction action of the first cylinder and the second cylinder is provided between the first oil cylinder and the second oil cylinder.

[0009] The telescopic arm telescopic device of a truck-mounted crane of the present invention, wherein the piston rod of the first oil cylinder and the rear portion of the basic arm are hinged together via a first pin shaft, an articulated frame is provided on the cylinder body of the first oil cylinder, an upper portion of the articulated frame and the rear portion of the second-section arm are hinged together via a second pin shaft, a piston rod of the second oil cylinder, a lower portion of the articulated frame and the rear portion of the second-section arm are hinged together via a third pin shaft, and a cylinder body of the second oil cylinder and the rear portion of the three-section arm are hinged together via a fourth pin shaft.

[0010] The telescopic arm telescopic device of a truck-mounted crane of the present invention, wherein the upper and lower parts of the articulated frame are respectively provided with a first axial hole and a second axial hole, the piston rod and the cylinder body of the second oil cylinder are respectively provided with a third axial hole and a fourth axial hole, the second pin passes through the first axial hole of the articulated frame and the axial hole at the rear of the second-section arm so that the two are hinged together, the third pin passes through the second axial hole of the articulated frame, the axial hole at the rear of the second-section arm and the third axial hole of the second oil cylinder so that the three are hinged together, and the fourth pin passes through the fourth axial hole of the second oil cylinder and the axial hole at the rear of the three-section arm so that the two are hinged together.

[0011] The telescopic arm telescopic device of a truck mounted crane of the present invention, wherein the first shaft hole, the second shaft hole and the fourth shaft hole are all oblong holes.

[0012] The telescopic boom extension and retracting device of the truck-mounted crane of the present invention, wherein the first cable structure includes a five-section boom extension boom cable, the five-section boom extension boom cable passes around a first half pulley arranged at the rear of the five-section boom, two first pulleys arranged at the front of the four-section boom, and then both ends are fixed to the front of the three-section boom.

[0013] The telescopic arm telescopic device of the truck-mounted crane of the present invention, wherein the second cable structure includes a four-section arm extension cable, one end of the four-section arm extension cable is hinged to the rear of the four-section arm through a pin shaft, and the other end is hinged to the rear of the two-section arm through a pin shaft after passing around a bracket pulley on the cylinder bracket arranged at the front of the second oil cylinder.

[0014] The invention discloses a telescopic arm telescopic device for a truck-mounted crane, wherein the trigger assembly comprises a control valve arranged at the front end of a first oil cylinder body and an adjusting striker arranged on the oil cylinder bracket, wherein the adjusting striker and the control valve are arranged front and back relative to each other.

[0015] The telescopic arm telescopic device of a truck-mounted crane of the present invention, wherein the oil cylinder bracket is connected with a mounting plate, and the adjusting striker is mounted on the mounting plate.

[0016] The invention discloses a telescopic arm telescopic device for a truck-mounted crane, wherein the control valve is a mechanical oil cylinder sequential telescopic control valve.

[0017] The telescopic arm telescopic device of the truck-mounted crane of the present invention, wherein the third cable structure includes a telescopic arm cable, after the telescopic arm cable passes around the second half pulley arranged at the front of the five-section arm, the two ends of the telescopic arm cable respectively pass around the second pulley arranged at the rear of the second cylinder body and the third pulley arranged at the front of the first cylinder body, and then are hinged to the rear of the three-section arm through a pin shaft.

[0018] After adopting the above scheme, the telescopic arm telescopic device of the truck-mounted crane of the present invention has the following beneficial effects:

[0019] 1. The present invention adopts a third pin shaft to pass through the third shaft hole on the piston rod of the second oil cylinder and the second shaft hole on the tail of the second boom and the hinge frame to hinge the three together, and the second shaft hole on the hinge frame is designed to have a larger aperture and be an oblong hole. This arrangement allows the thrust of the second oil cylinder to be directly transmitted to the rear of the second boom, and then transmitted from the rear of the second boom to the third pin shaft hinged between the first oil cylinder and the second boom, so that the first oil cylinder is not affected by the eccentric force, thereby improving the stability of the piston rod of the first oil cylinder;

[0020] 2. The first oil cylinder and the second oil cylinder move independently of each other. The first axis hole, the second axis hole and the fourth axis hole on the articulated frame are designed as oblong holes, which can avoid the first oil cylinder and the second oil cylinder from jumping due to the manufacturing gap error of the boom, the assembly error and the height difference when the two oil cylinders enter and exit the five-section boom;

[0021] 3. The four-section boom cable adopts a cast-in-place rope structure with multiple steel wire ropes, which bypass the bracket pulley on the cylinder bracket. This design can improve the carrying capacity of the four-section boom cable;

[0022] 4. The trigger assembly disposed between the first oil cylinder and the second oil cylinder has a simple structure, and the contact size between the adjusting striker of the trigger assembly and the striker of the mechanical oil cylinder sequential telescopic control valve is easy to adjust and ensure;

[0023] 5. The sequential extension and retraction of the first cylinder and the second cylinder is controlled by a mechanical cylinder sequential extension and retraction control valve, which has simple hydraulic control and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the front view of the telescopic arm telescopic device of the truck-mounted crane of the present invention;

[0025] Figure 2 for Figure 1 AA section structural diagram;

[0026] Figure 3 for Figure 1 BB-direction cross-sectional structural diagram;

[0027] Figure 4 for Figure 1 Schematic diagram of the CC-section structure;

[0028] Figure 5 It is a schematic diagram of the main structure of the first telescopic cylinder of the present invention;

[0029] Figure 6 for Figure 5 DD-direction cross-sectional structural diagram;

[0030] Figure 7 It is a schematic diagram of the main structure of the second telescopic cylinder of the present invention;

[0031] Figure 8 for Figure 7 EE section structure schematic diagram. DETAILED DESCRIPTION

[0032] like Figures 1 to 4 As shown, the telescopic boom extension and retracting device of the truck mounted crane of the present invention comprises a first oil cylinder 1, a second oil cylinder 2, and a tubular basic boom 3, a two-section boom 4, a three-section boom 5, a four-section boom 6 and a five-section boom 7 which are nested and assembled with each other.

[0033] refer to Figure 5 , Figure 6 As shown, the piston rod of the first oil cylinder 1 is hinged to the rear of the basic arm 3 through the first pin 8, and the cylinder body of the first oil cylinder 1 is provided with an articulated frame 9, and the upper and lower parts of the articulated frame 9 are respectively provided with a first axis hole 10 and a second axis hole 11, and the first axis hole 10 and the second axis hole 11 are both oblong holes. The articulated frame 9 and the rear part of the second section arm 4 are articulated together through the second pin 12 passing through the first axis hole 10 and the axis hole at the rear of the second section arm 4.

[0034] refer to Figure 7 , Figure 8As shown, the piston rod and cylinder body of the second oil cylinder 2 are respectively provided with a third shaft hole 13 and a fourth shaft hole 14, and the fourth shaft hole 14 is an oblong hole. The piston rod of the second oil cylinder 2, the articulated frame 9 and the rear part of the second section arm 4 are hinged together by a third pin shaft 15 passing through the third shaft hole 13, the second shaft hole 11 and the shaft hole at the rear part of the second section arm 4, and the cylinder body of the second oil cylinder 2 and the rear part of the three-section arm 5 are hinged together by a fourth pin shaft 16 passing through the fourth shaft hole 14 and the shaft hole at the rear part of the three-section arm 5.

[0035] Combination Figure 1 As shown, a first cable structure is connected between the front of the three-section boom 5, the four-section boom 6 and the front of the five-section boom 7. The first cable structure includes a five-section boom extension cable 17. The five-section boom extension cable 17 passes around the first half pulley arranged at the rear of the five-section boom 7 and the two first pulleys 18 arranged at the front of the four-section boom 6, and then the two ends are fixed to the front of the three-section boom 5 by bolts.

[0036] A second cable structure is connected between the second-section boom 4 and the fourth-section boom 6, and the second cable structure includes a four-section boom extension cable 19, one end of which is hinged to the rear of the four-section boom 6 through a pin shaft, and the other end passes around a bracket pulley 21 on a cylinder bracket 20 arranged at the front of the second oil cylinder 2, and is then hinged to the rear of the second-section boom 4 through a pin shaft.

[0037] A third cable structure is connected between the three-section boom 5 and the five-section boom 7, and the third cable structure includes a retractable arm cable 22. After the retractable arm cable 22 passes around the second half pulley set at the front of the five-section boom 7, both ends of the cable pass around the second pulley 23 set at the rear of the cylinder body of the second cylinder 2 and the third pulley 24 set at the front of the cylinder body of the first cylinder 1, and then are hinged to the rear of the three-section boom 5 through a pin shaft.

[0038] A trigger assembly for controlling the telescopic movement of the first oil cylinder 1 and the second oil cylinder 2 is provided between the first oil cylinder 1 and the second oil cylinder 2. The trigger assembly includes a control valve 25 provided at the front end of the cylinder body of the first oil cylinder 1 and an adjusting striker 26 provided on the oil cylinder bracket 20. In this embodiment, the control valve 25 adopts a mechanical oil cylinder sequential telescopic control valve, and the adjusting striker 26 is arranged front and back opposite to the control valve 25. A mounting plate 27 is connected to the oil cylinder bracket 20, and the adjusting striker 26 is installed on the mounting plate 27.

[0039] Boom extension process: the cylinder body of the first cylinder 1 extends outward, driving the second boom 4, the third boom 5, the fourth boom 6 and the fifth boom 7 to extend outward as a whole. After the first cylinder 1 is fully extended, the oil circuit is controlled by the control valve 25 to make the cylinder body of the second cylinder 2 extend outward, pushing the third boom 5 to extend outward. At the same time, the fourth boom extension cable 19 pulls the fourth boom 6, and the fifth boom extension cable 17 pulls the fifth boom 7 to extend synchronously.

[0040] Boom retraction process: the cylinder body of the second cylinder 2 retracts first, the three-section boom 5 is driven to retract by the second cylinder 2, the boom retraction cable 22 pulls the five-section boom 7 to retract, and at the same time, the five-section boom extension cable 17 retracts the four-section boom 6, and the three-section boom 5, the four-section boom 6, and the five-section boom 7 retract synchronously; after the cylinder body of the second cylinder 2 is fully retracted, the oil circuit is controlled by the control valve 25 to retract the cylinder body of the first cylinder 1, driving the two-section boom 4, the three-section boom 5, the four-section boom 6, and the five-section boom 7 to retract.

[0041] The present invention adopts a third pin shaft 15 to pass through the third axial hole 13 on the piston rod of the second oil cylinder 2 and the second axial hole 11 on the tail of the second boom 4 and the articulated frame 9 so that the three are hinged together, and the second axial hole 11 on the articulated frame 9 is designed to have a larger aperture and be an oblong hole. This arrangement can directly transmit the thrust of the second oil cylinder 2 to the rear of the second boom 4, and then transmit it from the rear of the second boom 4 to the third pin shaft 15 on which the first oil cylinder 1 and the second boom 4 are hinged, so that the first oil cylinder 1 is not affected by the eccentric force, thereby improving the stability of the piston rod of the first oil cylinder 1; the first oil cylinder 1 and the second oil cylinder 2 move independently of each other, and the first axial hole 10, the second axial hole 11 and the fourth axial hole 14 on the articulated frame 9 are all designed as oblong holes. It can avoid the first cylinder 1 and the second cylinder 2 from jumping due to the manufacturing gap error of the boom, assembly error and the height difference when the two cylinders enter and exit the five-section boom; the four-section boom extension cable 19 adopts a rope row structure with multiple steel wire ropes cast in parallel, which bypasses the bracket pulley 21 on the cylinder bracket 20. This design can improve the carrying capacity of the four-section boom extension cable 19; the trigger component arranged between the first cylinder 1 and the second cylinder 2 has a simple structure, and the contact size between the adjusting striker 26 of the trigger component and the striker block of the mechanical cylinder sequential telescopic control valve 25 is easy to adjust and ensure; the sequential telescopic movement of the first cylinder 1 and the second cylinder 2 is controlled by the mechanical cylinder sequential telescopic control valve 25, and the hydraulic control is simple and the energy consumption is low.

[0042] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering and technical personnel in the field shall fall within the protection scope of the claims of the present invention.

Claims

1. A telescopic arm extension device for a truck-mounted crane, characterized in that: It comprises a first oil cylinder, a second oil cylinder and a basic arm, a two-section arm, a three-section arm, a four-section arm and a five-section arm which are nested and assembled with each other, the piston rod of the first oil cylinder is connected to the rear part of the basic arm, the cylinder body of the first oil cylinder is connected to the rear part of the two-section arm and the piston rod of the second oil cylinder, the cylinder body of the second oil cylinder is connected to the rear part of the three-section arm, a first cable structure is connected between the front parts of the three-section arm, the four-section arm and the five-section arm, a second cable structure is connected between the two-section arm and the four-section arm, a third cable structure is connected between the three-section arm and the five-section arm, and a trigger component for controlling the telescopic action of the first oil cylinder and the second oil cylinder is provided between the first oil cylinder and the second oil cylinder; The piston rod of the first oil cylinder is hinged to the rear part of the basic arm through a first pin shaft, the cylinder body of the first oil cylinder is provided with an articulated frame, the upper part of the articulated frame and the rear part of the second-section arm are hinged together through a second pin shaft, the piston rod of the second oil cylinder, the lower part of the articulated frame and the rear part of the second-section arm are hinged together through a third pin shaft, and the cylinder body of the second oil cylinder and the rear part of the three-section arm are hinged together through a fourth pin shaft; The upper and lower parts of the articulated frame are respectively provided with a first axial hole and a second axial hole, the piston rod and the cylinder body of the second oil cylinder are respectively provided with a third axial hole and a fourth axial hole, the second pin passes through the first axial hole of the articulated frame and the axial hole at the rear of the second-section arm so that the two are hinged together, the third pin passes through the second axial hole of the articulated frame, the axial hole at the rear of the second-section arm and the third axial hole of the second oil cylinder so that the three are hinged together, and the fourth pin passes through the fourth axial hole of the second oil cylinder and the axial hole at the rear of the three-section arm so that the two are hinged together; The first axial hole, the second axial hole and the fourth axial hole are all oblong holes; The first cable structure comprises a five-section boom extension cable, which passes over a first half pulley arranged at the rear of the five-section boom, two first pulleys arranged at the front of the four-section boom, and two ends of which are fixed to the front of the three-section boom; The second cable structure comprises a four-section boom extension cable, one end of which is hinged to the rear of the four-section boom through a pin shaft, and the other end of which is hinged to the rear of the two-section boom through a pin shaft after passing around a bracket pulley on a cylinder bracket arranged at the front of the second oil cylinder; The trigger assembly includes a control valve arranged at the front end of the first oil cylinder body and an adjusting striker arranged on the oil cylinder bracket, and the adjusting striker and the control valve are arranged front and back oppositely; The third cable structure includes a retractable arm cable. After the retractable arm cable passes around the second half pulley set at the front of the five-section arm, the two ends of the retractable arm cable pass around the second pulley set at the rear of the second cylinder body and the third pulley set at the front of the first cylinder body, and then are hinged to the rear of the three-section arm through a pin shaft.

2. The telescopic arm retracting device of a truck mounted crane according to claim 1, characterized in that: The oil cylinder bracket is connected with a mounting plate, and the adjusting striker is mounted on the mounting plate.

3. The telescopic arm retracting device of a truck mounted crane according to claim 1, characterized in that: The control valve adopts a mechanical oil cylinder sequential telescopic control valve.

Images