Ladder fire truck arm device and control method thereof, and ladder fire truck

Abstract

The present invention relates to a boom device for a ladder fire truck and a control method thereof, and a ladder fire truck. The boom device comprises: a plurality of arms, which are nested and two adjacent arms are retractable, wherein the Nth arm (1) located at the end comprises a straight arm section and a curved arm section, and the curved arm section is located inside the N-1st arm (2) when the Nth arm (1) is in a fully retracted state; a first locking structure comprises a first guide groove (4) and a first locking pin (6), wherein the first guide groove (4) is provided on the Nth arm (1), The first locking pin (6) is arranged on the N-1th arm (2), the first guide groove (4) has a first open end (41) and a first closed end (42), and the first locking pin (6) is used to enter and exit the first guide groove (4) from the first open end (41); and a locking detection component (8) is arranged on the N-th arm (1) and is used to detect whether the first locking pin (6) reaches the first closed end (42) to determine whether the N-th arm (1) and the N-1th arm (2) are locked.

Description

Technical Field

[0001] The present disclosure relates to the technical field of fire fighting machinery, and in particular to an aerial ladder fire truck boom device and a control method thereof, and an aerial ladder fire truck. Background Art

[0002] At present, there are two main types of ladder fire trucks: straight arm ladder fire trucks and straight curved arm ladder fire trucks. Among them, the straight curved arm ladder fire truck has a more flexible operation process, and the working platform can achieve leapfrogging rescue through the curved arm action. This type of straight curved arm fire truck can be divided into two types: curved arm external type and curved arm internal type. Each section of the boom is actually in a nested form. This article takes a four-section boom as an example, and adopts the upward offset method of each section of the boom for easy display. The boom may include a first section boom 1a, a second section boom 2a, a third section boom 3a and a fourth section boom 4a.

[0003] like Figure 1 As shown, the curved arm 42a of the external straight curved arm aerial ladder vehicle is connected to the outside of the fourth arm 4a. Due to the overall length limit of the boom, the curved arm 42a at the front end will be limited by the length of the entire vehicle and cannot be designed according to the length of other booms.

[0004] like Figure 2 As shown, the built-in straight-curved arm aerial ladder truck is no different from the straight arm aerial ladder truck in appearance when the vehicle is folded. The fourth arm 4a includes a last straight arm 41a and a curved arm 42a hinged thereto. After the curved arm 42a is extended, the amplitude can be changed. Therefore, it has the common advantages of a straight arm and a curved arm, and can provide faster and more convenient rescue operations for the aerial ladder fire truck.

[0005] Since the built-in straight-bend boom ladder truck adopts asynchronous telescopic method, it is difficult to detect the telescopic state of the boom during the telescopic process, resulting in a higher safety risk when the boom is in motion. Summary of the invention

[0006] The present invention provides a ladder fire truck arm device and a control method thereof, and a ladder fire truck, which can improve the safety of the arm extension and retraction action.

[0007] According to a first aspect of the present disclosure, there is provided an arm device of a ladder fire truck, comprising:

[0008] The multi-section boom is nested and the two adjacent sections are retractable. The Nth section boom located at the end of the boom device includes a straight arm section and a curved arm section. The curved arm section is located inside the N-1th section boom when the Nth section boom is fully retracted.

[0009] A first locking structure, comprising a first guide groove and a first locking pin, the first guide groove being provided on the Nth arm section, the first locking pin being provided on the N-1th arm section, the first guide groove having a first open end and a first closed end, the first locking pin being configured to enter and exit the first guide groove from the first open end; and

[0010] The locking detection component is arranged on the Nth arm and is configured to detect whether the first locking pin reaches the first closed end to determine whether the Nth arm and the N-1th arm are locked.

[0011] In some embodiments, the lock detection component is located at the first closed end.

[0012] In some embodiments, the locking detection component is no higher than the surface with the smallest radial dimension on the (N-1)th arm.

[0013] In some embodiments, the ladder fire truck arm device further includes:

[0014] The controller is configured to stop the extension of the boom device when no detection signal is received from the locking detection component during the boom extension process and the Nth boom exceeds the safe extension length.

[0015] In some embodiments, the ladder fire truck arm device further includes:

[0016] The second locking structure includes a second guide groove and a second locking pin. The second guide groove is arranged on the N-2th arm section, and the second locking pin is arranged on the N-1th arm section. The second guide groove has a second open end and a second closed end. The second locking pin is configured to enter and exit the second guide groove from the second open end, and lock the N-1th arm section with the N-2th arm section when reaching the second closed end.

[0017] In some embodiments, the first locking pin and the second locking pin are arranged side by side along the width direction of the arm device, and when the first locking pin is located at the first open end, the second locking pin is located at the second closed end.

[0018] In some embodiments, the first open end is disposed close to the second closed end, the first closed end and the second open end extend in directions away from each other, and the first guide groove and the second guide groove have opposite bending directions along the width direction of the arm device.

[0019] In some embodiments, the ladder fire truck arm device further includes:

[0020] A connecting block is provided on the N-1th arm section, and the first locking pin and the second locking pin are both provided on the connecting block; and

[0021] A linear drive component has a first end hinged to the connecting block and a second end hinged to the N-1th arm.

[0022] In some embodiments, the ladder fire truck arm device further includes:

[0023] A boom length detection component, disposed at the root region of the first boom section, configured to detect the total length or the extended length of the boom; and / or

[0024] a two-section full retraction detection component, disposed at the root area of ​​the first section boom, configured to detect whether the second section boom is fully retracted relative to the first section boom; and / or

[0025] A fully retracted boom detection component is provided at the head of the Nth boom section and is configured to detect whether the Nth boom section is fully retracted; and / or

[0026] The two-section full extension detection component is arranged between the first section boom and the second section boom and is configured to detect whether the second section boom is fully extended.

[0027] According to a second aspect of the present disclosure, a ladder fire truck is provided, comprising the ladder fire truck boom device of the above embodiment.

[0028] According to a third aspect of the present disclosure, a control method for the ladder fire truck according to the above embodiment is provided, comprising:

[0029] detecting, by a locking detection component, whether the first locking pin reaches the first closed end;

[0030] When the first locking pin reaches the first closed end, it is determined that the Nth arm and the N-1th arm are locked.

[0031] In some embodiments, during the process of the boom extending, the control method further includes:

[0032] When no detection signal from the locking detection component is received and the Nth boom exceeds the safe extension length, the boom device stops extending.

[0033] In some embodiments, during the process of extending the boom, the control method further includes:

[0034] When the extension length of the Nth boom section L2 ≤ L1-L3, the Nth boom section can continue to extend; L1 is the distance from the head of the Nth boom section to the first guide groove, and L3 is the distance from the center of the first locking pin to the head of the Nth boom section when the boom device is fully retracted;

[0035] When the first locking pin reaches the first open end of the first guide groove, the boom safety verification length is set to Ls, where Ls is the maximum extension length allowed for the Nth boom relative to the N-1th boom, Ls=L1-L3+(N-1)*L0, where L0 is the dimension of the first guide groove along the length direction of the boom assembly, and the boom safety extension judgment protection mechanism is implemented.

[0036] In some embodiments, the boom safety extension judgment protection mechanism includes:

[0037] When the boom continues to extend and L1-L3<L2≤Ls, the first and second section full retraction detection components detect whether the second section boom is fully retracted relative to the first section boom. If fully retracted, it is determined that the N-1 section boom and the N-2 section boom are not successfully unlocked, and a boom action error is output, stopping the boom extension action.

[0038] In some embodiments, the boom safety extension judgment protection mechanism includes:

[0039] When the boom continues to extend and L2>Ls+△L1, △L1 is the allowable over-extension length of the boom. The locking detection component detects whether the first locking pin reaches the first closed end of the first guide groove. If no signal is received, it is determined that the N-1th boom and the Nth boom are not successfully locked, and a boom action error is output to stop the boom extension action.

[0040] In some embodiments, during the boom retraction process, the control method further includes:

[0041] When the extended length of the Nth boom L2>Ls-△L2, the 2nd to N-1th booms can continue to be retracted synchronously; Ls is the safety verification length of the boom and Ls=L1-L3+(N-1)*L0, L0 is the dimension of the first guide groove along the length direction of the boom assembly, L1 is the distance from the head of the Nth boom to the first guide groove, L3 is the distance from the center of the first locking pin to the head of the Nth boom when the boom device is fully retracted, and △L2 is the allowable over-retraction length of the boom;

[0042] When the second locking pin reaches the second opening end of the second guide groove, the arm support safety retraction judgment protection mechanism is performed.

[0043] In some embodiments, the boom safety retraction judgment protection mechanism includes:

[0044] When the boom continues to retract and the extended length L1-L3-△L2<L2<Ls-△L2, the first locking structure starts to unlock and the second locking structure starts to lock. The locking detection component detects whether the first locking pin is at the first closed end. If a signal is received, it is determined that there is an unlocking failure between the Nth boom and the N-1th boom, the boom action error is output, and the boom retraction action is stopped.

[0045] In some embodiments, the boom safety retraction judgment protection mechanism includes:

[0046] When the boom continues to retract and L2<L1-L3-△L2, the first and second section full retraction detection components are used to detect whether the second section boom is fully retracted relative to the first section boom. If full retraction is not detected, it is determined that there is a locking fault between the N-2 section boom and the N-1 section boom, the boom action error is output, and the boom retraction action is stopped.

[0047] In some embodiments, the control method further comprises:

[0048] When the boom device is fully extended and the boom length detection component detects that the extended length of the boom has reached the maximum length or the boom full extension detection component detects, the boom extension action is stopped; and / or

[0049] When the boom device is fully retracted into position and the boom length detection component detects that the retracted length of the boom has reached the minimum length or the crank arm fully retracted detection component detects, the boom retraction action is stopped.

[0050] The boom device of the ladder fire truck of the disclosed embodiment is provided with a locking detection component. When the boom device is extended, after the Nth boom is extended into place, it can detect that the Nth boom and the N-1th boom are reliably locked. Only if they are locked can the 2nd to N-1th booms be extended, thereby preventing the Nth boom from overextending. When the boom device is retracted, after the N-1th boom is retracted into place, it can detect that the Nth boom and the N-1th boom are reliably unlocked. Only if they are unlocked can the Nth boom be retracted, thereby preventing the 2nd to N-1th booms from overextending. In this way, the boom device can be prevented from continuing to move in a dangerous direction, thereby reducing safety hazards and improving the safety of the boom device operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0052] Figure 1 The schematic diagram of the boom device of an external straight-boom aerial ladder truck is shown in FIG.

[0053] Figure 2 It is a schematic diagram of the arm device principle diagram of the built-in straight and curved arm aerial ladder truck.

[0054] Figure 3 It is a top view of some embodiments of the boom device of the ladder fire truck disclosed in the present invention.

[0055] Figure 4 It is a bottom view of some embodiments of the boom device of the ladder fire truck disclosed in the present invention.

[0056] Figure 5 The following is a dimensional relationship diagram of some embodiments of the boom device of the ladder fire truck disclosed in the present invention.

[0057] Figure 6 The present invention is a flow chart of some embodiments of a method for controlling a boom device of a ladder fire truck during an extension process.

[0058] Figure 7 The present invention is a flowchart of some embodiments of a method for controlling a boom device of a ladder fire truck during a retraction process.

[0059] Description of Reference Numerals

[0060] 1. Nth boom section; 2. N-1th boom section; 3. N-2th boom section; 3-1. Second boom section; 3-2. First boom section; 3-3. Bracket; 4. First guide groove; 41. First open end; 42. First closed end; 5. Second guide groove; 51. Second open end; 52. Second closed end; 6. First locking pin; 7. Second locking pin; 8. Locking detection component; 9. Linear drive component; 10. Connecting block; 20. Boom length detection component; 30. One or two-section full retraction detection component; 40. Boom full retraction detection component; 50. Two-section full extension detection component; 60. Winch device. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without carrying out creative work are within the scope of protection of the present disclosure.

[0062] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0063] In the description of the present disclosure, it should be understood that the terms "center", "lateral", "longitudinal", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present disclosure.

[0064] In the description of the present disclosure, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0065] Built-in straight-and-curved arm fire truck: a straight-and-curved arm ladder fire truck in which the curved arm part is hinged with the last section of the straight arm ladder and embedded in the second-last section of the arm frame.

[0066] Asynchronous extension and retraction: The extension and retraction of each section of the ladder frame are not synchronized. For embedded straight and curved arm aerial ladder trucks, the ladder frame extension action requires the last section of the ladder to be extended to a certain stroke, and then the rest of the ladder frames are extended synchronously. The ladder frame retraction is the reverse process of the ladder frame extension.

[0067] In the related art, for the safety detection of boom extension, in one scheme, a pull-rope type length detection device is used, which is mainly used for the length detection of ladder fire trucks with synchronous extension and retraction systems, and cannot be used for the length detection of ladder fire trucks with asynchronous extension and retraction systems.

[0068] For ladder fire trucks that use a winch for synchronous and asynchronous extension and retraction of the boom, the boom length can also be calculated by setting an encoder on the winch to calculate the number of winch rotations. Although this detection method can solve the length detection problem of ladder fire trucks with asynchronous extension and retraction systems.

[0069] For this solution, the inventor found that it is unable to determine the abnormal extension and retraction of the boom caused by the failure of the boom locking mechanism to lock or unlock, resulting in over-extension or over-retraction of the boom. If the locking mechanism is abnormal, the boom continues to extend and retract, causing the wire rope to break or the boom to be damaged. The control system will not alarm and cannot restrict the movement, so there is a safety risk in the movement of the boom.

[0070] like Figures 3 to 5 As shown, the present disclosure provides a boom device for a ladder fire truck, which in some embodiments includes:

[0071] The multi-section boom is nested and the two adjacent sections are retractable. The N-th section boom 1 located at the end of the boom device includes a straight section and a curved section. The curved section is located inside the N-1 section boom 2 when the N-th section boom 1 is fully retracted.

[0072] A first locking structure, comprising a first guide groove 4 and a first locking pin 6, wherein the first guide groove 4 is provided on the Nth arm 1 located at the end of the boom device, and the first locking pin 6 is provided on the N-1th arm 2, wherein the first guide groove 4 has a first open end 41 and a first closed end 42, and the first locking pin 6 is configured to enter and exit the first guide groove 4 from the first open end 41; and

[0073] The locking detection component 8 is provided on the Nth arm 1 and is configured to detect whether the first locking pin 6 reaches the first closed end 42 to determine whether the Nth arm 1 and the N-1th arm 2 are locked.

[0074] The multi-section arm includes the first section arm 3-2, the second section arm 3-1, ..., the N-2 section arm 3, the N-1 section arm 2 and the N-1 section arm 1 from the tail to the head, and the cross-sectional area gradually decreases, and the first section arm 3-2 is embedded in the bracket 3-3. For the built-in straight and curved arm ladder truck, the N-th section arm 1 includes a straight arm section and a curved arm section connected to each other. When the arm device is retracted, the straight arm section and the curved arm section are retracted into the N-1 section arm 2.

[0075] After the first locking pin 6 enters the first guide groove 4 from the first open end 41, the N-1th arm 2 and the Nth arm 1 begin to be locked, and the first locking pin 6 slides along the first guide groove 4. When the first locking pin 6 reaches the first closed end 42, the N-1th arm 2 and the Nth arm 1 are completely locked and cannot move relative to each other. When the first locking pin 6 slides from the first closed end 42 toward the first open end 41, the N-1th arm 2 and the Nth arm 1 begin to be unlocked, and the N-1th arm 2 and the Nth arm 1 can start to move relative to each other. After the first locking pin 6 is disengaged from the first guide groove 4, the N-1th arm 2 and the Nth arm 1 are completely unlocked.

[0076] The locking detection component 8 is provided on the Nth arm 1, and can be a contact or non-contact detection component. When the first locking pin 6 reaches the first closed end 42, the locking detection component 8 can send a trigger signal. If the controller receives the trigger signal, it determines that the Nth arm 1 and the N-1th arm 2 are locked. If the trigger signal is not received, it determines that the Nth arm 1 and the N-1th arm 2 are not locked. For example, the locking detection component 8 can be a photoelectric sensor, etc., or can also be a travel switch.

[0077] The boom device of this type of built-in straight-bend aerial ladder truck has the following steps: when the boom is extending, the Nth boom 1 is extended first, and after being extended into place, the Nth boom 1 and the N-1th boom 2 are locked, and at the same time the N-1th boom 2 and the N-2th boom 3 are unlocked, and then the 2nd to N-1th booms are extended synchronously; when the boom is retracting, the Nth boom 1 and the N-1th boom 2 remain locked, and the 2nd to N-1th booms are retracted synchronously, and after being retracted into place, the N-1th boom 2 and the N-2th boom 3 are locked, and at the same time the Nth boom 1 and the N-1th boom 2 are unlocked, and then the Nth boom 1 is retracted.

[0078] In this embodiment, a locking detection component 8 is provided in the boom device of the built-in straight-bend aerial ladder truck. When the boom device is extended, after the first locking pin 6 enters the first guide groove 4 from the first opening end 41, the boom is in the process of locking the Nth section and the N-1th section and unlocking the N-1th section and the N-2th section. During this process, the 2nd to Nth sections of the boom are in a simultaneous extension state. After the Nth section of the boom 1 is extended into place, it can be detected that the Nth section of the boom 1 and the N-1th section of the boom 2 are reliably locked. Only if they are locked can the 2nd to N-1 sections of the boom be extended, thereby preventing the Nth section of the boom 1 from being overextended; when the boom device is retracted, after the N-1th section of the boom 2 is retracted into place, it can be detected that the Nth section of the boom 1 and the N-1th section of the boom 2 are reliably unlocked. Only if they are unlocked can the Nth section of the boom 1 be retracted, thereby preventing the 2nd to N-1 sections of the boom from being over-retracted. In this way, the boom can be prevented from continuing to move in a dangerous direction, wire rope breakage or boom damage can be avoided, safety hazards can be reduced, and the safety of the boom device movement can be improved.

[0079] In some embodiments, the locking detection component 8 is located at the first closed end 42. When the first locking pin 6 reaches the first closed end 42, this structure can detect more accurately.

[0080] In some embodiments, the locking detection component 8 is not higher than the surface with the smallest radial dimension on the N-1th boom 2. The locking detection component 8 can be installed in a planar manner, and the locking detection component 8 will not be affected during the extension and retraction process of the Nth boom 1 relative to the N-1th boom 2.

[0081] In some embodiments, the boom device of the ladder fire truck also includes: a controller, which is configured to stop the extension of the boom device when no detection signal is received from the locking detection component 8 during the boom extension process and the Nth boom section 1 exceeds the safe extension length.

[0082] This embodiment can, when the boom is extended, if the first locking pin 6 does not enter the first guide groove 4, the locking detection component 8 has no sensing signal entering the vehicle controller. At this time, it is judged that there is no interlocking between the Nth boom 1 and the N-1th boom 2. At the same time, the length state of the boom is judged. If it exceeds the safe extension length, the boom extension action is terminated; and an abnormal boom action state alarm is performed to prevent dangerous conditions caused by overextension of the boom, thereby achieving safe control of the boom telescopic action.

[0083] In some embodiments, Figure 3 and Figure 4As shown, the boom device of the ladder fire truck also includes: a second locking structure, including a second guide groove 5 and a second locking pin 7, the second guide groove 5 is arranged on the N-2th arm section 3, the second locking pin 7 is arranged on the N-1th arm section 2, the second guide groove 5 has a second open end 51 and a second closed end 52, the second locking pin 7 is configured to enter and exit the second guide groove 5 from the second open end 51, and when reaching the second closed end 52, the N-1th arm section 2 and the N-2th arm section 3 are locked.

[0084] After the second locking pin 7 enters the second guide groove 5 from the second open end 51, the N-1th arm 2 and the N-2th arm 3 begin to be locked, and the second locking pin 7 slides along the second guide groove 5. When the second locking pin 7 reaches the second closed end 52, the N-1th arm 2 and the N-2th arm 3 are completely locked and cannot move relative to each other. When the second locking pin 7 slides from the second closed end 52 toward the second open end 51, the N-1th arm 2 and the N-2th arm 2 begin to be unlocked, and the N-1th arm 2 and the N-2th arm 3 can start to move relative to each other. After the second locking pin 7 is disengaged from the second guide groove 5, the N-1th arm 2 and the N-2th arm 3 are completely unlocked.

[0085] The working process of extending and retracting the boom device is described below.

[0086] When the boom is extended, the Nth boom 1 is extended first, and the other booms are in a static state. When the telescopic system is extended to a set length (greater than the length of the crank arm section), the locking mechanism is triggered. After the Nth boom 1 is extended to a certain distance, the first locking pin 6 enters the first guide groove 4, and the second locking pin 7 moves out of the second guide groove 5. The Nth boom 1 is locked with the N-1th boom 2, so that the N-2nd boom 3 is unlocked with the N-1st boom 2. Continue to extend the boom, then in the boom device, except that the Nth boom 1 is static relative to the N-1st boom 2, the 2nd to N-2nd booms are all extended synchronously relative to the first boom 3-2.

[0087] When the boom is retracting, the Nth boom 1 and the N-1th boom 2 remain locked, and the 2nd to N-1st booms are synchronously retracted to the set length, triggering the locking mechanism to move, the first locking pin 6 moves out of the first guide slot 4, and the second locking pin 7 enters the second guide slot 5, so that the Nth boom 1 and the N-1st boom 2 are unlocked, and the N-2nd boom 3 and the N-1st boom 2 are locked. In the boom device, except for the Nth boom 1 retracting relative to the N-1st boom 2, the other 2nd to N-2nd booms are stationary relative to the first boom 3-2. Continue the boom retraction operation, and the Nth boom 1 retracts alone to the driving state.

[0088] In some embodiments, Figure 3As shown, the first locking pin 6 and the second locking pin 7 are arranged side by side along the width direction of the arm device and their relative positions are fixed. When the first locking pin 6 is located at the first open end 41 , the second locking pin 7 is located at the second closed end 52 .

[0089] This embodiment can make the second locking pin 7 just move out of the second guide groove 5 to unlock the N-2nd boom 3 and the N-1st boom 2 when the first locking pin 6 just enters the first guide groove 4 to start locking the Nth boom 1 and the N-1th boom 2. This structure can keep other booms in a locked state when a specific boom is in motion, thereby improving the safety of the boom device.

[0090] In some embodiments, the first open end 41 is arranged near the second closed end 52, the first closed end 42 and the second open end 51 extend in directions away from each other, and the first guide groove 4 and the second guide groove 5 have opposite bending directions along the width direction of the arm device. For example, the first open end 41 and the second closed end 52 are arranged in an area of ​​the arm device close to the first side along the width direction, the first closed end 42 and the second open end 51 extend toward an area close to the second side, and the extension path has opposite bending directions. For example, the first guide groove 4 and the second guide groove 5 can be arc-shaped. This structure can meet the path requirements when the first locking pin 6 and the second locking pin 7 move synchronously.

[0091] In some embodiments, the boom device of the ladder fire truck further includes: a connecting block 10, which is arranged on the N-1th arm section 2, and the first locking pin 6 and the second locking pin 7 are both arranged on the connecting block 10; and a linear drive component 9, a first end of which is hinged to the connecting block 10, and a second end of which is hinged to the N-1th arm section 2. For example, the linear drive component 9 can be a gas spring, a cylinder, a hydraulic cylinder, an electric push rod, etc.

[0092] In this embodiment, the linear drive component 9 drives the connecting block 10 to move along the width direction of the arm device, which can simultaneously drive the first locking pin 6 and the second locking pin 7 to move, thereby realizing the linkage control of locking and unlocking.

[0093] In some embodiments, Figure 5 As shown, the arm device of the ladder fire truck also includes:

[0094] The boom length detection component 20 is disposed at the root area of ​​the first boom 3-2 and is configured to detect the total length or the extended length of the boom; for example, the hoisting device 60 drives the telescopic winch to drive the wire rope to move, and the boom length detection component 20 can use a multi-turn encoder to detect and calculate the extended length of the ladder frame; and / or

[0095] The one-two-section full retraction detection component 30 is provided at the root area of ​​the first section boom 3-2 and is configured to detect whether the second section boom 3-1 is fully retracted relative to the first section boom 3-2. When the second section boom 3-1 is fully retracted, the third section boom to the N-2 section boom are also fully retracted. For example, the one-two-section full retraction detection component 30 may be a photoelectric sensor, a travel switch, etc.; and / or

[0096] The fully retracted crank arm detection component 40 is provided at the head of the Nth boom section 1 and is configured to detect whether the Nth boom section 1 is fully retracted. For example, the fully retracted crank arm detection component 40 may be a photoelectric sensor, a travel switch, etc.; and / or

[0097] The two-section full extension detection component 50 is disposed between the first boom 3-2 and the second boom 3-1 and is configured to detect whether the second boom 3-1 is fully extended. The two-section full extension detection component 50 can be used to detect the final stop position when the boom is extended.

[0098] This embodiment, by providing the above-mentioned detection component and the locking detection component 8, can perform composite detection when the boom device is in motion, and judge the working state of the boom device from multiple aspects to achieve safe control of the asynchronous telescopic device.

[0099] Secondly, the present disclosure provides a ladder fire truck, including: the ladder fire truck arm device of the above embodiment.

[0100] Finally, the present disclosure provides a control method for the boom device of a ladder fire truck based on the above embodiment, comprising:

[0101] Detecting whether the first locking pin 6 reaches the first closed end 42 by the locking detection component 8;

[0102] When the first locking pin 6 reaches the first closed end 42 , it is determined that the Nth arm 1 and the N−1th arm 2 are locked.

[0103] In this embodiment, when the boom device is extended, after the Nth boom 1 is extended to the right position, it can detect that the Nth boom 1 and the N-1th boom 2 are reliably locked. Only when they are locked can the 2nd to N-1th booms be extended, thus preventing the Nth boom 1 from over-extending; when the boom device is retracted, after the N-1th boom 2 is retracted to the right position, it can detect that the Nth boom 1 and the N-1th boom 2 are reliably unlocked. Only when they are unlocked can the Nth boom 1 be retracted, thus preventing the 2nd to N-1th booms from over-retracting. In this way, the boom can be prevented from continuing to move in a dangerous direction, wire rope breakage or boom damage can be avoided, safety hazards can be reduced, and the safety of the boom device operation can be improved.

[0104] In some embodiments, during the process of extending the boom, the control method further includes:

[0105] When no detection signal is received from the locking detection component 8 and the Nth boom 1 exceeds the safe extension length, the boom device stops extending.

[0106] This embodiment can, when the boom is extended, if the first locking pin 6 does not enter the first guide groove 4, the locking detection component 8 has no sensing signal entering the vehicle controller. At this time, it is judged that there is no interlocking between the Nth boom 1 and the N-1th boom 2. At the same time, the length state of the boom is judged. If it exceeds the safe extension length, the boom extension action is terminated; and an abnormal boom action state alarm is performed to prevent dangerous conditions caused by overextension of the boom, thereby achieving safe control of the boom telescopic action.

[0107] The following introduces the safety control methods of the boom device during the extension and retraction processes. First, some key dimensional parameters are explained and defined.

[0108] Set the length of the first guide slot 4 to L0, the total length of the boom device to L, the length of the first boom 3-2 (basic boom) to Lb, the extension length of the Nth boom to L2, the distance from the head of the Nth boom to the first guide slot 4 to L1, when the boom is fully retracted, set the distance from the center of the first guide pin 6 to the arm head of the Nth boom to L3, △L1 is the allowable over-extension length of the boom, △L2 is the allowable over-retraction length of the boom, △L1 and △L2 are both relative to the entire boom, N is the number of boom sections, Ls is the boom safety verification length, Ls is the maximum allowable extension length of the Nth boom 1 relative to the N-1th boom 2, then the following relationship exists:

[0109] L2=L-Lb;

[0110] When the first locking pin 6 begins to enter the first guide groove 4, the second locking pin 7 begins to unlock, so the Nth boom 1 and the N-1th boom 2 are locked, the N-1th boom 2 and the N-2nd boom 3 are unlocked, and the 2nd to N-2nd booms are extended at the same time. When the Nth boom 1 is extended relative to the N-1th boom 2 by a distance of L0, the extension length of the boom is in a multiple speed relationship, so the boom safety verification length Ls is as follows:

[0111] Ls=L1-L3+(N-1)*L0;

[0112] Since the boom length detection component 20 is calculated by detecting the number of winch rotations and encoder conversion, the number of encoder rotations is set to n, and the encoder single-turn resolution is S0, the total length L of the detection boom is:

[0113] L==L2+Lb=nS0+Lb.

[0114] In some embodiments, during the process of extending the boom, the control method further includes:

[0115] When the extension length L2 of the Nth boom 1 is less than or equal to L1-L3, the Nth boom 1 can continue to be extended; L1 is the distance from the head of the Nth boom 1 to the first guide groove 4, and L3 is the distance from the center of the first locking pin 6 to the head of the Nth boom 1 when the boom device is fully retracted;

[0116] When the first locking pin 6 reaches the first opening end 41 of the first guide groove 4, the boom safety verification length is set to Ls, Ls=L1-L3+(N-1)*L0, L0 is the dimension of the first guide groove 4 along the length direction of the boom assembly, and the boom safety extension judgment protection mechanism is performed.

[0117] In this embodiment, when the Nth boom 1 is extended to the point where the first locking pin 6 reaches the first open end 41 of the first guide groove 4, the Nth boom 1 and the N-1th boom 2 begin to be locked. However, the locking may not be performed normally at this node, or the controller may not receive a signal normally after locking. At this time, the boom safety extension judgment protection mechanism is activated to improve the safety of the boom when it is extended.

[0118] In some embodiments, the boom safety extension judgment protection mechanism includes:

[0119] When the boom continues to extend and L1-L3<L2≤Ls, the first and second section full retraction detection component 30 detects whether the second section boom 3-1 is fully retracted relative to the first section boom 3-2. If it is fully retracted, it is determined that the unlocking between the N-1 section boom 2 and the N-2 section boom 3 is not successful, and a boom action error is output to stop the boom extension action.

[0120] In this embodiment, when the N-th boom 1 continues to extend to the length of the first locking pin 6 exceeding the first opening end 41 and does not exceed the boom safety verification length Ls, it means that the N-1th boom 2 and the N-2th boom 3 have begun to be unlocked, and the second boom 3-1 to the N-2th boom 3 have been synchronously extended. If the one-two-section full-retraction detection component 30 detects that the second boom 3-1 is still in a fully retracted state relative to the first boom 3-2, it means that the N-1th boom 2 and the N-2th boom 3 have not been successfully unlocked, and the N-1th boom 2 may be overextended, which is equivalent to judging whether the locking component is working normally from another angle. Therefore, stopping the boom from extending can improve the safety of the boom device operation.

[0121] In some embodiments, the boom safety extension judgment protection mechanism includes:

[0122] When the boom continues to extend and L2>Ls+△L1, △L1 is the allowable over-extension length of the boom. The locking detection component 8 detects whether the first locking pin 6 reaches the first closed end 42 of the first guide groove 4. If no signal is received, it is determined that the N-1th boom 2 and the Nth boom 1 are not successfully locked, and a boom action error is output to stop the boom extension action.

[0123] When the extended length of the Nth boom 1 exceeds Ls+△L1, if the boom locking function is normal, the locking detection component 8 will send a detection signal. If not received, it means that the extended length of the Nth boom 1 has reached the limit, and the first locking pin 6 has not yet entered the first guide groove 4. At this time, it is determined that the N-1th boom 2 and the Nth boom 1 are not successfully locked. If they continue to be extended, it will cause dangerous movement of the boom. At this time, stopping the boom extension action can improve the safety of the boom.

[0124] In some embodiments, during the boom retraction process, the control method further includes:

[0125] In the case that the extended length L2 of the Nth boom 1 is greater than Ls-△L2, the 2nd to N-1th booms can continue to be retracted synchronously; Ls is the safety verification length of the boom and Ls=L1-L3+(N-1)*L0, L0 is the dimension of the first guide slot 4 along the length direction of the boom assembly, L1 is the distance from the head of the Nth boom 1 to the first guide slot 4, L3 is the distance from the center of the first locking pin 6 to the head of the Nth boom 1 when the boom device is fully retracted, and △L2 is the over-retraction length allowed for the boom;

[0126] When the second locking pin 7 reaches the second opening end 51 of the second guide slot 5, the arm support safety retraction judgment protection mechanism is performed.

[0127] In this embodiment, when the N-2th boom 3 is retracted until the second locking pin 7 reaches the second open end 51 of the second guide groove 5, the N-2th boom 3 and the N-1th boom 2 begin to be locked. However, it is possible that the locking is not performed normally at this node, or the controller does not normally receive the unlocking signal of the detection component 8 after locking. At this time, the boom safety extension judgment protection mechanism is activated, which can improve the safety of the boom when it is retracted.

[0128] In some embodiments, the boom safety retraction judgment protection mechanism includes:

[0129] When the boom continues to retract and the extended length L1-L3-△L2<L2<Ls-△L2, the first locking structure starts to unlock and the second locking structure starts to lock. The locking detection component 8 detects whether the first locking pin 6 is at the first closed end 42. If a signal is received, it is determined that there is an unlocking failure between the Nth boom 1 and the N-1th boom 2, and the boom action error is output, and the boom retraction action is stopped.

[0130] In this embodiment, when the Nth boom 1 continues to retract to the above-mentioned numerical range, the first locking structure should begin to unlock, that is, the first locking pin 6 is not at the first closed end 42. If the controller receives a signal from the locking detection component 8, it means that the N-1th boom 2 and the Nth boom 1 have not been successfully unlocked. At this time, if the boom continues to retract, the 2nd to N-2nd booms 2 will be over-retracted. At this time, stopping the boom retraction can improve the safety of the boom movement.

[0131] In some embodiments, the boom safety retraction judgment protection mechanism includes:

[0132] When the boom continues to retract and L2<L1-L3-△L2, the first and second section full retraction detection component 30 detects whether the second section boom 3-1 is fully retracted relative to the first section boom 3-2. If full retraction is not detected, it is determined that there is a locking fault between the N-2 section boom 3 and the N-1 section boom 2, the boom action error is output, and the boom retraction action is stopped.

[0133] In this embodiment, after the 2nd to N-2nd boom sections 2 are retracted to make the boom extension amount L2 to the length within L1-L3-△L2, if the boom locking function is normal, the N-2nd boom section 3 and the N-1th boom section 2 are already locked, and the N-1th boom section 2 has been retracted into position. If the one-two-section full-retraction detection component 30 detects that the second boom section 3-1 is not fully retracted relative to the first boom section 3-2, it means that there is a locking fault between the N-2nd boom section 3 and the N-1th boom section 2. If the boom continues to be retracted, the problem of over-retraction will occur, causing dangerous movement of the boom. At this time, stopping the boom retraction action can improve the safety of the boom.

[0134] In some embodiments, the control method of the present disclosure further includes:

[0135] When the boom device is fully extended and the boom length detection component 20 detects that the extended length of the boom has reached the maximum, or the boom full extension detection component 50 detects that the boom extension action is stopped; and / or

[0136] When the boom device is fully retracted and the boom length detection component 20 detects that the retracted length of the boom has reached the minimum amplitude, or the crank arm fully retracted detection component 40 detects, the boom retraction action is stopped.

[0137] This embodiment, based on monitoring the telescopic state of the boom device through the locking detection component 8 and the one-two section full retraction detection component 30, further provides final safety assurance through the maximum extension and maximum retraction ranges, which can further improve the safety of the boom device operation.

[0138] The above-mentioned limiting boom movements are all logical controls designed to prevent boom damage. Under the condition that all detections are normal, when the fully retracted boom detection component 40 sends a detection signal and the detection value of the boom length detection component 20 reaches the minimum detection value, it is considered that the entire boom is fully retracted and the corresponding limiting action after the boom is fully retracted can be performed.

[0139] The present disclosure aims to design an asynchronous telescopic safety locking detection system and its boom safety judgment logic and control method, which can perform corresponding boom length verification and logic judgment through corresponding length and position detection to ensure the safety of the boom telescopic process. It can realize whether the locking state of the Nth boom 1 and the unlocking state of the N-2nd boom 3 are in place during the boom extension process, and whether the unlocking state of the Nth boom 1 and the locking state of the N-2nd boom 3 are in place during the boom retraction process, complete the monitoring of these four fault states and the boom safety action control, avoid the occurrence of wire rope breakage and boom damage caused by the failure of the locking mechanism, and realize the safe and effective operation of the vehicle.

[0140] The present invention adds a locking detection for the locking mechanism of the asynchronous telescopic system. Through corresponding logical control, it can effectively avoid the risk of excessive extension of the boom caused by continuous extension of the boom due to failure of the locking mechanism. At the same time, during the retraction process of the boom, it can effectively avoid the occurrence of damage to the boom caused by continued retraction of the boom by judging the locking device detection, thereby ensuring the safety of the operation of the straight and curved arm ladder fire truck during the retraction process of the asynchronous telescopic system.

[0141] Since the asynchronous telescopic built-in straight-bend boom ladder truck has a different telescopic principle from that of a straight-arm or external straight-bend boom ladder truck, its telescopic principle is that the Nth section arm 1 is first extended to a certain length, and then the 2nd to N-1th sections are extended synchronously. The telescopic and extension are all achieved by stretching the wire rope by the telescopic winch. Simply relying on the length sensor cannot accurately determine whether the ladder frame is extended and retracted according to the setting principle. It is easy for the locking pin to fail to enter the guide groove to lock the boom frame. At the same time, the locking pin cannot effectively exit the guide groove and the unlocking fails. This will cause the boom frame to be over-extended or over-retracted, but the control system will not alarm, which poses a safety hazard. Therefore, the present disclosure proposes a safety locking detection device for this asynchronous telescopic extension, and designs a corresponding composite logic control method to ensure the safety of the telescopic process of the asynchronous telescopic system of the built-in straight-bend boom ladder truck.

[0142] The following is a detailed description of the safety control method during the extension and retraction of the boom device.

[0143] like Figure 6 As shown, in the process of extending the boom, the Nth boom 1 is extended first, which includes the following steps:

[0144] 1. Read the value of the arm length detection component 20 to calculate the number of rotations of the encoder;

[0145] 2. Calculate the boom length L and the extension length L2;

[0146] 3. Determine whether the extended length of the boom satisfies L2>L1-L3, and determine whether the full retraction detection of the first and second sections is in place. If L2>L1-L3 is satisfied and the full retraction detection of the first and second sections is in place, stop the boom movement and end; if L2>L1-L3 is satisfied and the full retraction detection of the first and second sections is not detected to be in place, determine whether the extended length of the boom satisfies L2>Ls. If L2>Ls is not satisfied, the Nth boom 1 is allowed to continue to be extended. If L2>Ls is satisfied, determine whether the locking detection component is detected in place. If the locking detection is in place, the 2~N-1 sections of the boom are extended synchronously. If the locking detection is not in place, determine whether the extended length of the boom satisfies L2<Ls+△L1. If L2<Ls+△L1 is satisfied, the Nth boom 1 is allowed to continue to be extended. If L2<Ls+△L1 is not satisfied, stop the boom extension.

[0147] 4. If the extended length of the boom does not satisfy L2>L1-L3 and the first and second sections are not fully retracted, the boom is stopped from being extended; if the extended length of the boom does not satisfy L2>L1-L3 and the first and second sections are fully retracted, it is determined whether the locking detection component is in place. If it is in place, the boom is stopped from being extended; if it is not in place, the Nth section boom 1 continues to be extended.

[0148] 5. Determine whether the boom is fully extended and reaches the maximum length limit. If so, stop extending the boom.

[0149] like Figure 7 As shown, during the boom retraction process, the 2nd to N-1th boom sections 2 are retracted synchronously first, which includes the following steps:

[0150] 1. Read the value of the arm length detection component 20 to calculate the number of rotations of the encoder;

[0151] 2. Calculate the boom length L and the extension length L2;

[0152] 3. Determine whether the extended length of the boom satisfies L2>Ls-△L2. If L2>Ls-△L2 is satisfied, the boom continues to retract.

[0153] 4. If the extended length of the boom does not satisfy L2>Ls-△L2, determine whether the locking detection is in place. If so, stop the boom movement; if not, determine whether the extended length of the ladder frame satisfies L2<L1-L3-△L2. If not, continue to retract the boom. If L2<L1-L3-△L2 is satisfied, determine whether the one or two sections are fully retracted. If so, continue to retract the boom. If L2<L1-L3-△L2 is satisfied and the one or two sections are fully retracted, stop the boom retraction.

[0154] 5. Determine whether the boom is fully retracted and has reached the minimum length. If so, stop the boom from retracting.

[0155] The above are merely exemplary embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A boom device for a ladder fire truck, characterized in that: include: A multi-section boom is nested and two adjacent sections are retractable, the Nth section boom (1) located at the end of the boom device comprises a straight arm section and a curved arm section, and the curved arm section is located within the N-1th section boom (2) when the Nth section boom (1) is in a fully retracted state; A first locking structure, comprising a first guide groove (4) and a first locking pin (6), wherein the first guide groove (4) is provided on the Nth arm section (1), and the first locking pin (6) is provided on the N-1th arm section (2), the first guide groove (4) having a first open end (41) and a first closed end (42), and the first locking pin (6) is configured to enter and exit the first guide groove (4) from the first open end (41); The second locking structure comprises a second guide groove (5) and a second locking pin (7), wherein the second guide groove (5) is provided on the N-2th arm section (3), and the second locking pin (7) is provided on the N-1th arm section (2), wherein the second guide groove (5) has a second open end (51) and a second closed end (52), and the second locking pin (7) is configured to enter and exit the second guide groove (5) from the second open end (51), and to achieve locking of the N-1th arm section (2) and the N-2th arm section (3) when reaching the second closed end (52); The first locking pin (6) and the second locking pin (7) are arranged side by side along the width direction of the arm support device, and when the first locking pin (6) is located at the first open end (41), the second locking pin (7) is located at the second closed end (52); and when the first locking pin (6) just enters the first guide groove (4) to start locking the Nth arm section (1) and the N-1th arm section (2), the second locking pin (7) just moves out of the second guide groove (5) to start unlocking the N-2th arm section (3) and the N-1th arm section (2); A locking detection component (8) is provided on the Nth arm (1) and is configured to detect whether the first locking pin (6) reaches the first closed end (42) to determine whether the Nth arm (1) and the N-1th arm (2) are locked; and A controller is configured to determine that the Nth arm (1) and the N-1th arm (2) are locked when the first locking pin (6) reaches the first closed end (42); The invention is configured such that, during the process of extending the boom: when the extension length L2 of the Nth boom (1) is less than or equal to L1-L3, the Nth boom (1) is allowed to continue to extend, L1 is the distance from the head of the Nth boom (1) to the first guide groove (4), and L3 is the distance from the center of the first locking pin (6) to the head of the Nth boom (1) when the boom device is fully retracted; when the first locking pin (6) reaches the first opening end (41) of the first guide groove (4), the boom safety verification length is set to Ls, Ls=L1-L3+(N-1)*L0, L0 is the dimension of the first guide groove (4) along the length direction of the boom assembly, and the boom safety extension judgment protection mechanism is performed.

2. The boom device of the ladder fire truck according to claim 1, characterized in that: The locking detection component (8) is located at the location of the first closed end (42).

3. The boom device of the ladder fire truck according to claim 1, characterized in that: The locking detection component (8) is not higher than the surface with the smallest radial dimension on the N-1th arm (2).

4. The boom device of the ladder fire truck according to claim 1, characterized in that: The controller is configured to stop the extension action of the boom device when no detection signal from the locking detection component (8) is received during the boom extension process and the Nth boom section (1) exceeds the safe extension length.

5. The boom device of a ladder fire truck according to claim 1, characterized in that: The first open end (41) is arranged close to the second closed end (52), the first closed end (42) and the second open end (51) extend in directions away from each other, and the first guide groove (4) and the second guide groove (5) have opposite bending directions along the width direction of the arm device.

6. The boom device of a ladder fire truck according to claim 1, characterized in that: Also includes: A connecting block (10) is provided on the N-1th arm (2), and the first locking pin (6) and the second locking pin (7) are both provided on the connecting block (10); and A linear drive component (9) has a first end hinged to the connection block (10) and a second end hinged to the N-1th arm (2).

7. The boom device of a ladder fire truck according to any one of claims 1 to 6, characterized in that: Also includes: A boom length detection component (20) is disposed in the root region of the first boom section (3-2) and is configured to detect the total length or extended length of the boom; and / or a two-section full retraction detection component (30), disposed at the root region of the first section boom (3-2), and configured to detect whether the second section boom (3-1) is fully retracted relative to the first section boom (3-2); and / or A crank arm fully retracted detection component (40) is provided at the head of the Nth boom section (1) and is configured to detect whether the Nth boom section (1) is fully retracted; and / or The two-section full extension detection component (50) is arranged between the first section arm (3-2) and the second section arm (3-1) and is configured to detect whether the second section arm (3-1) is fully extended.

8. A ladder fire truck, characterized in that: include: The boom device of a ladder fire truck according to any one of claims 1 to 7.

9. A control method for the boom device of a ladder fire truck according to any one of claims 1 to 7, characterized in that: include: Detecting, by means of the locking detection component (8), whether the first locking pin (6) has reached the first closed end (42); When the first locking pin (6) reaches the first closed end (42), it is determined that the Nth arm (1) and the N-1th arm (2) are locked; During the process of the boom extending, the control method further includes: When the extension length L2 of the Nth boom (1) is less than or equal to L1-L3, the Nth boom (1) can continue to be extended; L1 is the distance from the head of the Nth boom (1) to the first guide groove (4), and L3 is the distance from the center of the first locking pin (6) to the head of the Nth boom (1) when the boom device is fully retracted; When the first locking pin (6) reaches the first opening end (41) of the first guide slot (4), the boom safety verification length is set to Ls, where Ls=L1-L3+(N-1)*L0, L0 being the dimension of the first guide slot (4) along the length direction of the boom assembly, and the boom safety extension judgment protection mechanism is performed.

10. The control method according to claim 9, characterized in that: During the process of the boom extending, the control method further includes: When no detection signal is received from the locking detection component (8) and the Nth boom (1) exceeds the safe extension length, the boom device stops extending.

11. The control method according to claim 9, characterized in that: The arm safety extension judgment protection mechanism includes: When the boom continues to extend and L1-L3<L2≤Ls, the first and second section full retraction detection component (30) detects whether the second section boom (3-1) is fully retracted relative to the first section boom (3-2). If it is fully retracted, it is determined that the N-1 section boom (2) and the N-2 section boom (3) are not successfully unlocked, and a boom action error is output, stopping the boom extension action.

12. The control method according to claim 9, characterized in that: The arm safety extension judgment protection mechanism includes: When the boom continues to extend and L2>Ls+△L1, △L1 is the over-extension length allowed by the boom, the locking detection component (8) detects whether the first locking pin (6) reaches the first closed end (42) of the first guide groove (4). If no signal is received, it is determined that the N-1th boom (2) and the Nth boom (1) are not successfully locked, and a boom action error is output, stopping the boom extension action.

13. The control method according to claim 9, characterized in that: During the boom retraction process, the control method further includes: In the case where the extended length L2 of the Nth boom (1) is greater than Ls-△L2, the 2nd to N-1th booms can continue to be retracted synchronously; Ls is the boom safety verification length and Ls=L1-L3+(N-1)*L0, L0 is the dimension of the first guide groove (4) along the length direction of the boom assembly, L1 is the distance from the head of the Nth boom (1) to the first guide groove (4), L3 is the distance from the center of the first locking pin (6) to the head of the Nth boom (1) when the boom device is fully retracted, and △L2 is the over-retraction length allowed for the boom; When the second locking pin (7) reaches the second opening end (51) of the second guide groove (5), the arm support safety retraction judgment protection mechanism is performed.

14. The control method according to claim 13, characterized in that: The arm safe retraction judgment protection mechanism includes: When the boom continues to retract and the extended length L1-L3-△L2<L2<Ls-△L2, the first locking structure starts to unlock and the second locking structure starts to lock. The locking detection component (8) detects whether the first locking pin (6) is at the first closed end (42). If a signal is received, it is determined that there is an unlocking fault between the Nth boom section (1) and the N-1th boom section (2), an output boom action error is generated, and the boom retraction action is stopped.

15. The control method according to claim 13, characterized in that: The arm safe retraction judgment protection mechanism includes: When the boom continues to retract and L2 < L1-L3-△L2, the first and second section full retraction detection components (30) detect whether the second section boom (3-1) is fully retracted relative to the first section boom (3-2). If full retraction is not detected, it is determined that there is a locking fault between the N-2 section boom (3) and the N-1 section boom (2), an output boom action error is generated, and the boom retraction action is stopped.

16. The control method according to claim 9, characterized in that: The boom device of the ladder fire truck comprises: a boom length detection component (20) configured to detect the total length or the extended length of the boom; a crank arm full retraction detection component (40) configured to detect whether the Nth boom section (1) is fully retracted; and a second-section full extension detection component (50) configured to detect whether the second boom section (3-1) is fully extended; The control method further comprises: When the boom device is fully extended and the boom length detection component (20) detects that the extended length of the boom has reached the maximum length or the two-section full extension detection component (50) detects, the boom extension action is stopped; and / or When the boom device is fully retracted into position and the boom length detection component (20) detects that the retracted length of the boom has reached a minimum length or the crank arm fully retracted detection component (40) detects, the boom retraction action is stopped.

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