A control method of an aerial ladder and the aerial ladder

Abstract

The present application relates to the technical field of engineering machinery, and particularly relates to a control method of a ladder truck and the ladder truck. The control method of the ladder truck is to detect an angle value between an arm frame and a horizontal plane in real time, calculate a target elongation length of the arm frame and a target load of a trolley according to the detected angle value, control an actual elongation length of the arm frame to be not more than the target elongation length, and control an actual load of the trolley to be not more than the target load. By using the control method of the ladder truck provided in the present embodiment, the problem of deformation or fracture of the arm frame caused by overelongation of the arm frame or overloading of the trolley can be avoided, and the safety of the ladder truck during operation is ensured.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to a control method for a ladder truck and the ladder truck itself. Background Technology

[0002] Self-propelled aerial ladder trucks are off-road engineering machinery, mainly composed of a self-propelled off-road chassis and a telescopic boom. The top of the boom must be attached to the material conveying terminal; the boom cannot operate while suspended in the air. Currently, the booms of existing aerial ladder trucks require manual judgment of movement position and load capacity when loading materials, performing boom angle changes, slewing, telescopic movements, lowering of auxiliary ladders, and retraction. While vehicle-mounted aerial ladder trucks generally have skilled operators, overloading and improper operation remain frequent, leading to boom system breakage, deformation, and inability to retract. Since self-propelled aerial ladder trucks are primarily designed for untrained or inexperienced users, these problems need to be thoroughly addressed to ensure the safety of the aerial ladder boom during operation. Summary of the Invention

[0003] The purpose of this invention is to provide a control method and a ladder truck, which can avoid the problem of boom deformation or breakage caused by excessive boom extension or excessive load on the trolley, and ensure the safety of the ladder truck during operation.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A control method for a ladder truck includes real-time detection of the angle between the boom and the horizontal plane, calculation of the target extension length of the boom and the target load capacity of the trolley based on the detected angle, and control of the actual extension length of the boom not exceeding the target extension length and the actual load capacity of the trolley not exceeding the target load capacity.

[0006] As a preferred technical solution for the control method of the aerial ladder truck, multiple preset angle values ​​are set, and the multiple preset angle values ​​are divided into multiple angle intervals. Each angle interval corresponds to a target extension length interval and a target load interval. When the angle value between the boom and the horizontal plane is detected to be within any angle interval, the actual extension length of the boom is controlled to be within the target extension length interval corresponding to that angle interval, and the actual load of the trolley is controlled to be within the target load interval corresponding to that working interval.

[0007] As a preferred technical solution for the control method of the aerial ladder truck, a potentiometer is installed on the lower rotating shaft that is rotatably connected to the luffing cylinder and the chassis. The potentiometer can detect the angle between the boom and the horizontal plane in real time.

[0008] As a preferred technical solution for the control method of the aerial ladder truck, the first telescopic boom of the boom is provided with multiple detection points distributed at intervals along the telescopic direction of the boom, and the fixed boom of the boom is provided with a counting device. When the telescopic boom extends, the counting device can detect the number of extended detection points, thereby calculating the actual extension length of the boom.

[0009] As a preferred technical solution for the control method of the aerial ladder truck, the trolley drive mechanism that drives the trolley to slide on the boom includes a winch, a wire rope, and a fixed pulley. The winch is located on the fixed boom on the opposite side of the trolley and is driven by a motor. The fixed pulley is located on the end telescopic boom section. The wire rope is wound on the winch, and the free end of the wire rope passes over the fixed pulley and is connected to the trolley. The motor is equipped with a pressure sensor for detecting the pressure difference of the motor. By obtaining the pressure difference of the motor and the angle between the boom and the horizontal plane, the target load capacity of the trolley can be calculated.

[0010] As a preferred technical solution for the control method of the aerial ladder truck, when the boom is detected to be overlapping with the working face, the boom is prohibited from rotating.

[0011] As a preferred technical solution for the control method of the aerial ladder truck, when a sudden drop in pressure of the luffing cylinder is detected and the angle between the boom and the horizontal plane does not change, it is determined that the boom is in contact with the working surface.

[0012] As a preferred technical solution for the control method of the aerial ladder truck, when the sliding arm of the boom is detected to be touching the ground, the boom is prohibited from rotating.

[0013] As a preferred technical solution for the control method of the aerial ladder truck, a sliding groove is provided at the end of the sliding arm that touches the ground, a limit switch is provided at the bottom of the sliding groove, and a trigger rod is slidably arranged in the sliding groove. Whether the sliding arm touches the ground is detected by detecting whether the trigger rod triggers the limit switch.

[0014] A ladder truck, employing the ladder truck control method described in any of the above schemes.

[0015] The beneficial effects of this invention are:

[0016] This invention provides a control method for a ladder truck, which detects the angle between the boom and the horizontal plane in real time, calculates the target extension length of the boom and the target load capacity of the trolley based on the detected angle, and controls the actual extension length of the boom and the actual load capacity of the trolley to not exceed the target extension length and the target load capacity. For example, when the actual length of the boom exceeds the target extension length, the system will issue an alarm, prohibit further extension of the boom, and prevent the angle between the boom and the horizontal plane from decreasing further; similarly, when the actual load capacity of the trolley exceeds the target load capacity, the system will issue an alarm and prohibit the trolley from moving. By adopting the control method for the ladder truck provided in this embodiment, problems such as boom deformation or breakage caused by excessive boom extension or excessive trolley load can be avoided, ensuring the safety of the ladder truck during operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the ladder truck provided in an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the boom, trolley, and trolley drive mechanism involved in the embodiments of the present invention;

[0019] Figure 3 This is a flowchart illustrating the control method for the aerial ladder truck provided in this embodiment of the invention. Figure 1 ;

[0020] Figure 4 This is a flowchart illustrating the control method for the aerial ladder truck provided in this embodiment of the invention. Figure 2 ;

[0021] Figure 5 yes Figure 2 A magnified view of a section at point A in the middle;

[0022] Figure 6 This is a structural schematic diagram of the boom, luffing cylinder, and trolley involved in the embodiments of the present invention;

[0023] Figure 7 yes Figure 6 A magnified view of a section at point B in the middle;

[0024] Figure 8 This is a schematic diagram of the telescopic arm, detection point, and counting device involved in the embodiments of the present invention;

[0025] Figure 9 This is a force diagram of the variable amplitude cylinder involved in the embodiment of the present invention.

[0026] In the picture:

[0027] 10. Chassis; 11. Outriggers; 20. Slewing mechanism; 30. Boom; 31. Fixed boom; 32. Telescopic boom; 33. Sliding boom; 331. Sliding groove; 40. Luffing cylinder; 50. Trolley; 51. Trolley luffing mechanism; 61. Winch; 62. Wire rope; 63. Fixed pulley; 70. Potentiometer; 81. Detection point; 82. Counting device; 91. Limit switch; 92. Trigger rod. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0029] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this embodiment, the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0032] like Figures 1 to 2As shown, this embodiment of the invention provides a ladder truck, including a chassis 10, a boom 30, a luffing cylinder 40, a trolley 50, and a trolley drive mechanism. The boom 30 is mounted on the chassis 10 via a slewing mechanism 20, which drives the boom 30 to rotate. The boom 30 includes a fixed boom 31, multiple telescopic boom sections 32, and a sliding boom 33. The multiple telescopic boom sections 32 are connected in sequence, with the first telescopic boom section 32 connected to the upper end of the fixed boom 31, and the sliding boom 33 slidably connected to the lower end of the fixed boom 31. The fixed end of the luffing cylinder 40 is connected to the slewing mechanism 20 via a lower rotating shaft, and the telescopic end of the luffing cylinder 40 is connected to the fixed boom 31 of the boom 30 via an upper rotating shaft. The trolley 50 is slidably connected to the boom 30. The trolley drive mechanism drives the trolley 50 to slide along the extension direction of the boom 30. In this embodiment, the trolley drive mechanism includes a winch 61, a wire rope 62, and a fixed pulley 63. The winch 61 is located on the fixed arm 31 on the opposite side of the trolley 50. The fixed pulley 63 is located on the last telescopic arm 32. The wire rope 62 is wound around the winch 61, and the free end of the wire rope 62 passes around the fixed pulley 63 and is connected to the trolley 50.

[0033] After the ladder truck reaches its destination and is leveled by the outriggers 11, and before carrying heavy loads, it needs to be adjusted to its working state: First, operate the luffing cylinder 40 to raise the boom 30 to an angle basically parallel to the working surface; then operate the slewing mechanism 20 to rotate the boom 30 to a position opposite to the working surface; then operate the telescopic boom 32 drive mechanism to extend the telescopic boom 32; then operate the luffing cylinder 40 again to lower the boom 30 to overlap with the working surface; then operate the sliding boom drive mechanism to slide the sliding boom 33 to contact the ground; finally, adjust the trolley luffing mechanism 51 to luff the trolley 50 until it is parallel to the horizontal plane. After adjustment, heavy loads can be loaded onto the trolley 50, and the trolley drive mechanism will drive the trolley 50 to move along the boom 30 to carry the heavy loads.

[0034] To address the aforementioned adjustment process, embodiments of the present invention provide a control method for a ladder truck, such as... Figure 3As shown, the system continuously monitors the angle between the boom 30 and the horizontal plane, and calculates the target extension length of the boom 30 and the target load capacity of the trolley 50 based on the detected angle. It controls the actual extension length of the boom 30 to not exceed the target extension length, and the actual load capacity of the trolley 50 to not exceed the target load capacity. For example, when the actual length of the boom 30 exceeds the target extension length, the system will issue an alarm, simultaneously prohibiting the boom 30 from extending further and preventing the angle between the boom 30 and the horizontal plane from decreasing further. Similarly, when the actual load capacity of the trolley 50 exceeds the target load capacity, the system will issue an alarm and prohibit the trolley 50 from moving. By adopting the control method for the aerial ladder truck provided in this embodiment, the problem of boom 30 deformation or breakage due to excessive boom extension or excessive load capacity of the trolley 50 can be avoided, ensuring the safety of the aerial ladder truck during operation.

[0035] To simplify the control process, multiple preset angle values ​​are set and divided into multiple angle intervals. Each angle interval corresponds to a target extension length interval and a target load capacity interval. When the angle between the boom 30 and the horizontal plane is detected to be within any angle interval, the actual extension length of the boom 30 is controlled to be within the target extension length interval corresponding to that angle interval, and the actual load capacity of the trolley 50 is controlled to be within the target load capacity interval corresponding to that working interval. This interval division reduces the number of calculations and control operations, making the control process simpler.

[0036] The adjustment of the boom 30's extension length mainly involves two processes. The first process occurs after the boom 30 has risen to its maximum angle. At this point, adjusting the boom 30's extension length is relatively simple; it only requires detecting the angle between the boom 30 and the horizontal plane and calculating the target extension length based on this angle, ensuring that the boom 30's extension length does not exceed this target extension length. The second process occurs during the boom 30's descent to overlap with the working face. During this process, the angle between the boom 30 and the horizontal plane is constantly changing, therefore, the adjustment of the boom 30's extension length is also a dynamic process.

[0037] Furthermore, during the process of the boom 30 descending to overlap with the working face (i.e., the second process mentioned above), the angle between the boom 30 and the horizontal plane continuously decreases. At this time, the angle value and the extension length of the boom 30 are in a dynamic and continuous adjustment process until the target angle range and the target extension length range of the boom 30 are matched. Figure 4 As shown, the specific dynamic adjustment process is as follows:

[0038] S10, operating luffing cylinder 40, driving boom 30 luffing;

[0039] S20. Determine whether the angle between the boom 30 and the horizontal plane is within the target angle range. If yes, proceed to step S30; otherwise, return to step S10.

[0040] S30. Operate the telescopic arm drive mechanism to drive the telescopic arm 32 to extend or retract;

[0041] S40. Determine whether the extension length of the boom 30 is within the target extension length range. If yes, proceed to step S50; otherwise, return to step S30.

[0042] S50, control boom 30 overlaps with the working face;

[0043] S60. Determine whether the angle between the boom 30 and the horizontal plane is within the target angle range. If yes, end the process; otherwise, return to step S10.

[0044] In step S60, after the boom 30 overlaps with the working face, it is determined again whether the angle between the boom 30 and the horizontal plane is within the target range. This is because the angle between the boom 30 and the horizontal plane is constantly decreasing during the overlap process. At the moment of overlap, there may be a situation where the angle between the boom 30 and the horizontal plane jumps from the target angle range to the next angle range. Therefore, by determining whether the angle between the boom 30 and the horizontal plane is within the target range again after the boom 30 overlaps with the working face in step S60, it can be ensured that the target angle range of the boom 30 and the target extension length range are matched. If the angle value jumps, steps S10 to S60 are repeated until the target angle range of the boom 30 matches the target extension length.

[0045] In this embodiment, as Figure 6 and Figure 7 As shown, a potentiometer 70 is installed on the lower rotating shaft connected to the fixed end of the luffing cylinder 40 and the slewing mechanism 20. When the luffing cylinder 40 drives the boom 30 to rise or fall, the lower rotating shaft rotates, and the potentiometer 70 rotates with the lower rotating shaft. Therefore, the potentiometer 70 can detect the angle between the boom 30 and the horizontal plane in real time. The aforementioned preset angle values ​​are stored in the potentiometer 70. Alternatively, in other embodiments, the potentiometer 70 can also be installed on the upper rotating shaft connected to the telescopic end of the luffing cylinder 40 and the boom 30, and is not limited to this embodiment.

[0046] In this embodiment, as Figure 8As shown, the first telescopic boom 32 is provided with multiple detection points 81 spaced apart along the telescopic direction of the boom 30. A counting device 82 is provided on the fixed boom 31. When the telescopic boom 32 extends, the counting device 82 can detect the number of extended detection points 81. Let the initial length of the boom 30 be L0, the number of extended detection points 81 be n, the distance between two connected detection points 81 be s, and the number of sections of the telescopic boom 32 be a. Then, the actual extended length of the boom 30 is obtained as L = L0 + n × s × a. Using the above method, the actual extended length of the boom 30 can be obtained in real time. Alternatively, in other embodiments, the actual extended length of the boom 30 can be obtained by detecting the number of rotations of the winch 61 to calculate the length of the wire rope 62.

[0047] The adjustment of the target load capacity of the trolley 50 mainly occurs after the boom 30 overlaps with the working face. After the boom 30 successfully overlaps with the working face, the angle between the boom 30 and the horizontal plane no longer changes. At this time, the target load capacity of the trolley 50 is calculated based on the detected angle value between the boom 30 and the horizontal plane. When the trolley 50 is running under load, the load capacity of the trolley 50 is ensured to not exceed the target load capacity.

[0048] Specifically, the calculation process for the target load capacity of the trolley 50 is as follows:

[0049] If the angle between the boom 30 and the horizontal plane when the boom 30 overlaps with the working surface is set to θ, then after the material (mass mkg) is placed on the trolley 50, the material pulling force F on the winch 61 is F=m×g×sinθ;

[0050] Let r be the distance between the wire rope 62 and the center of the winch 61. Then the torque T provided by the winch 61 to the wire rope 62 is F × r.

[0051] The pressure difference required for the motor to provide torque to the winch 61 in the hydraulic system is given by , where Vg is the volumetric displacement (cm³) of the motor per revolution. 3 ;

[0052] The relationship between the material weight and the boom angle of 30° can be obtained from the above three formulas:

[0053] Therefore, after detecting the angle between the boom 30 and the horizontal plane, the target load capacity can be calculated according to the above formula. It should also be noted that the motor pressure differential VP can be measured by a pressure sensor.

[0054] Furthermore, when the load capacity of the trolley 50 exceeds the target load capacity, the machine will issue an alarm and prohibit the trolley 50 from moving up or down. These features further enhance the safety of the aerial ladder truck operation.

[0055] Furthermore, the control method for the aerial ladder truck provided in this embodiment also includes prohibiting the boom 30 from rotating after detecting that the boom 30 has overlapped with the working surface, in order to avoid deformation of the boom 30. In this embodiment, as... Figure 9 As shown, the pressure of the variable amplitude cylinder 40, F_cylinder = -(F1·(L1+L2)) / Where F1 is the weight of the boom 30's center of gravity, L1 is the horizontal distance from the center of gravity of the boom 30 to the upper hinge point of the luffing cylinder 40, L2 is the horizontal distance from the upper hinge point of the luffing cylinder 40 to the lower hinge point of the boom 30, and β is the angle between the luffing cylinder 40 and the horizontal plane. After the boom 30 overlaps with the working surface, the angle value detected by the angle sensor remains essentially unchanged, while the pressure value of the luffing cylinder 40 drops sharply. By combining the pressure of the luffing cylinder 40 and the detection value of the angle sensor, it can be determined whether the boom 30 has successfully overlapped with the working surface. Alternatively, in other embodiments, the contact of the boom 30 with the working surface can be mechanically detected by electrical devices such as a limit switch 91 or a proximity sensor.

[0056] The control method for the aerial ladder truck provided in this embodiment further includes prohibiting the boom 30 from rotating after the sliding arm 33 is detected to have touched the ground, in order to prevent deformation of the sliding arm 33. In this embodiment, as... Figure 5 As shown, a sliding groove 331 is provided at the end of the sliding arm 33 that touches the ground. A limit switch 91 is provided at the bottom of the sliding groove 331. A trigger rod 92 is slidably arranged in the sliding groove 331. Whether the sliding arm 33 touches the ground is detected by detecting whether the trigger rod 92 triggers the limit switch 91.

[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A control method for a ladder truck, characterized in that, The angle between the boom (30) and the horizontal plane is detected in real time. The target extension length of the boom (30) and the target load of the trolley (50) are calculated based on the detected angle value. The actual extension length of the boom (30) is controlled to not exceed the target extension length, and the actual load of the trolley (50) is controlled to not exceed the target load. This can prevent the boom (30) from deforming or breaking due to excessive extension or excessive load of the trolley (50). Multiple preset angle values ​​are set, and the multiple preset angle values ​​are divided into multiple angle intervals. Each angle interval corresponds to a target elongation length interval and a target load interval. When the angle value between the boom (30) and the horizontal plane is detected to be within any angle interval, the actual elongation length of the boom (30) is controlled to be within the target elongation length interval corresponding to the angle interval, and the actual load of the trolley (50) is controlled to be within the target load interval corresponding to the angle interval. Once it is detected that the boom (30) has overlapped with the working face, the boom (30) is prohibited from rotating. When a sudden drop in pressure is detected in the luffing cylinder (40) and the angle between the boom (30) and the horizontal plane does not change, it is determined that the boom (30) is in contact with the working surface.

2. The control method for the aerial ladder truck according to claim 1, characterized in that, A potentiometer (70) is installed on the lower rotating shaft that is rotatably connected to the luffing cylinder (40) and the chassis (10). The potentiometer (70) can detect the angle between the boom (30) and the horizontal plane in real time.

3. The control method for the aerial ladder truck according to claim 1, characterized in that, The first telescopic boom (32) of the boom (30) is provided with multiple detection points (81) spaced apart along the telescopic direction of the boom (30). The fixed arm (31) of the boom (30) is provided with a counting device (82). When the telescopic boom (32) extends, the counting device (82) can detect the number of the extended detection points (81), thereby calculating the actual extension length of the boom (30).

4. The control method for the aerial ladder truck according to claim 1, characterized in that, The trolley drive mechanism that drives the trolley (50) to slide on the boom (30) includes a winch (61), a wire rope (62), and a fixed pulley (63). The winch (61) is located on the fixed boom (31) on the opposite side of the trolley (50). The winch (61) is driven by a motor. The fixed pulley (63) is located on the end telescopic boom (32). The wire rope (62) is wound around the winch (61), and the free end of the wire rope (62) passes around the fixed pulley (63) and is connected to the trolley (50). The motor is equipped with a pressure sensor for detecting the pressure difference of the motor. By obtaining the pressure difference of the motor and the angle between the boom (30) and the horizontal plane, the target load of the trolley (50) can be calculated.

5. The control method for the aerial ladder truck according to any one of claims 1-4, characterized in that, Once the sliding arm (33) of the boom (30) is detected to be touching the ground, the boom (30) is prohibited from rotating.

6. The control method for the aerial ladder truck according to claim 5, characterized in that, The sliding arm (33) has a sliding groove (331) at one end that touches the ground. A limit switch (91) is provided at the bottom of the sliding groove (331). A trigger rod (92) is slidably arranged in the sliding groove (331). Whether the sliding arm (33) touches the ground is detected by detecting whether the trigger rod (92) triggers the limit switch (91).

7. A ladder truck, characterized in that, The control method for the aerial ladder truck as described in any one of claims 1-6 is adopted.

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