Boom device and fire fighting truck

Abstract

The utility model relates to the technical field of fire fighting, and provides an arm support device and a fire fighting truck, the arm support device comprises a main arm, a first driving mechanism, an offset arm and a second driving mechanism, and the main arm is a telescopic arm; the first driving mechanism is suitable for driving the pitching action of the main arm; the offset arm comprises at least three arm sections, the head end arm section of the offset arm is rotationally connected with the tail end arm section of the main arm, and the head end arm section of the offset arm is a telescopic arm or a folding arm; the second driving mechanism is suitable for driving the bias arm to be switched between the folded state and the unfolded state; in the folded state, the bias arms are located on the side of the main arm, and the bias arms are stacked into at least three layers. According to the arrangement, the offset arm is wholly or partially arranged to be in the structural form of the folding arm, the variable cross-section design of the offset arm is achieved, all the arm sections of the folding arm part of the offset arm are not overlapped in the unfolded state, the lightweight design of the offset arm is facilitated, sidewise bending of the main arm is reduced, and stable operation of the fire fighting truck is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of fire fighting, in particular to an arm device and a fire fighting truck. Background Art

[0002] In various aerial operations and fire rescue operations, operating machinery with foldable and unfoldable boom devices are used. For example, in a fire truck, the boom device is one of the key components that determine the overall operating performance of the fire truck. In order to ensure the rescue height of the fire truck, it is necessary to ensure the unfolded length of its boom device. Therefore, the boom device of the fire truck is gradually developing in the direction of super-long arms.

[0003] In the related art, the super-long boom device is set to a main boom plus an offset arm structure, the main boom is a telescopic boom, and some offset arms are set as a telescopic arm structure. Since the telescopic boom has certain requirements on the overlapping length of each boom section when it is deployed, and the cross-sectional size of each boom section varies relatively little, it is not conducive to lightweight design, resulting in a large weight of the offset arm. After the super-long boom device is deployed, the main boom has severe lateral bending, which is not conducive to stable operation.

[0004] Therefore, how to solve the problem of serious lateral bending of the main arm after unfolding of the super-long boom device in the related art has become an important technical problem to be solved by those skilled in the art. Utility Model Content

[0005] The utility model provides an arm device and a fire truck, which are used to solve the above technical problems.

[0006] The utility model provides an arm support device, comprising:

[0007] A main arm, wherein the main arm is a telescopic arm;

[0008] A first driving mechanism, adapted to drive the pitching action of the main arm;

[0009] An offset arm, the offset arm comprising at least three arm sections, the first end arm section of the offset arm being rotatably connected to the last end arm section of the main arm, the first end arm section of the offset arm being a telescopic arm or a folding arm;

[0010] a second driving mechanism, adapted to drive the biasing arm to switch between a folded state and an unfolded state;

[0011] Wherein, in the folded state, the offset arm is located on the side of the main arm, and the offset arms are stacked in at least three layers.

[0012] According to an arm support device provided by the utility model, along the distribution direction of the offset arm and the main arm, the projection area of ​​the offset arm is located inside the projection area of ​​the main arm or the projection area of ​​the offset arm coincides with the projection area of ​​the main arm.

[0013] According to an arm support device provided by the utility model, the offset arm comprises:

[0014] The first arm section, the second arm section and the third arm section are arranged in sequence and the adjacent two are rotatably connected;

[0015] The second driving mechanism comprises:

[0016] A second driving member is connected to the first arm section and the end arm section of the main arm respectively;

[0017] a third driving member, connected to the head ends of the first arm section and the second arm section respectively;

[0018] The fourth driving member is connected to the head ends of the second arm section and the third arm section respectively.

[0019] According to an arm support device provided by the utility model, when the offset arm is in a folded state, the third arm section is located between the first arm section and the second arm section;

[0020] Alternatively, when the biasing arm is in the folded state, the third arm section is located on a side of the second arm section away from the first arm section.

[0021] According to the utility model, a boom device is provided, which also includes:

[0022] An end head, wherein a first end of the end head is connected to an end of an end arm section of the main arm, and a second end of the end head extends along a distribution direction of the offset arm and the main arm;

[0023] The first end arm section of the offset arm is connected to the lower edge of the second end of the end head, and when the offset arm is in a folded state, the second arm section is located above the first arm section; or, the first end arm section of the offset arm is connected to the upper edge of the second end of the end head, and when the offset arm is in a folded state, the second arm section is located below the first arm section.

[0024] According to a boom device provided by the utility model, the second boom section includes a head end connection part, a tail end connection part and a transition part arranged between the head end connection part and the tail end connection part, and the head end connection part, the transition part and the tail end connection part form an integrated structure;

[0025] The axis of the head end connecting part and the axis of the tail end connecting part are both parallel to the axis of the main arm, the distance between the axis of the head end connecting part and the axis of the main arm is a first distance, and the distance between the axis of the tail end connecting part and the axis of the main arm is a second distance, and the first distance is greater than the second distance.

[0026] According to the arm support device provided by the utility model, the length of the end arm section of the offset arm can be telescopically adjusted.

[0027] According to a boom device provided by the utility model, the end arm section of the offset arm includes:

[0028] The first section and the second section are rotatably connected;

[0029] A fifth driving member is connected to the first section and the second section respectively, and the fifth driving member is suitable for driving the second section to rotate relative to the first section.

[0030] According to the arm device provided by the utility model, the length of the second section can be telescopically adjusted.

[0031] The utility model also provides a fire truck, comprising the above-mentioned arm support device.

[0032] The arm support device provided by the utility model comprises a main arm, a first driving mechanism, an offset arm and a second driving mechanism. The main arm is a telescopic arm, and the first driving mechanism is used to drive the pitching action of the main arm. The offset arm comprises at least three arm sections, and the head arm section of the offset arm is rotatably connected to the end arm section of the main arm, and the head arm section of the offset arm is a telescopic arm or a folding arm. The second driving mechanism is used to drive the offset arm to switch between a folded state and an unfolded state. In the folded state, the offset arm is located on the side of the main arm, and the offset arm is stacked in at least three layers. In this way, by setting the offset arm as a folding arm structure in whole or in part, a variable cross-section design of the offset arm is realized, and there is no requirement for the overlapping length of each arm section of the folding arm part of the offset arm in the unfolded state, and basically there is no overlap, which is conducive to the lightweight design of the offset arm, reduces the lateral bending of the main arm, and is conducive to the stable operation of the fire truck.

[0033] Furthermore, in the fire truck provided by the present invention, since it is provided with the arm device as described above, it also has the various advantages as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present utility model or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a structural schematic diagram of the arm support device provided by the utility model in the unfolded state.

[0036] Figure 2 It is a structural schematic diagram of the first arm support device provided by the utility model in a folded state.

[0037] Figure 3 It is a structural schematic diagram of the second arm support device provided by the utility model in a folded state.

[0038] Figure 4 It is a structural schematic diagram of the third arm support device provided by the utility model in a folded state.

[0039] Figure 5 It is a structural schematic diagram of the fourth boom device provided by the utility model in a folded state.

[0040] Figure 6 It is a structural schematic diagram of the fifth arm support device provided by the utility model in a folded state.

[0041] Figure 7 It is a structural schematic diagram of the sixth arm support device provided by the utility model in a folded state.

[0042] Figure 8 It is a top view of the arm support device provided by the utility model in a folded state.

[0043] Fig. 9 It is a structural schematic diagram of a first end arm section of the offset arm provided by the utility model.

[0044] Fig.10 It is a structural schematic diagram of a second end arm section of the offset arm provided by the utility model.

[0045] Fig.11 It is a structural schematic diagram of a third end arm section of the offset arm provided by the utility model.

[0046] Fig.12 It is a structural schematic diagram of a fourth end arm section of the offset arm provided by the utility model.

[0047] Fig.13It is a structural schematic diagram of the boom device provided by the utility model in an unfolded state (the third boom section is a segmented structure).

[0048] Reference numerals:

[0049] 1. Main arm; 2. First driving mechanism; 3. First arm section; 4. Second arm section; 5. Third arm section; 6. End; 7. First section; 8. Second section; 9. Fifth driving member; 10. End arm section of offset arm; 11. Vehicle body; 12. Water pipeline; 13. Head end connection part; 14. Transition part; 15. Tail end connection part; x, first distance; y, second distance. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0051] Combine the following Figures 1 to 13 The utility model describes the arm support device.

[0052] like Figures 1 to 13 As shown, the arm support device provided by the embodiment of the utility model includes a main arm 1, a first driving mechanism 2, an offset arm and a second driving mechanism.

[0053] Specifically, the main arm 1 is a telescopic arm, and the first driving mechanism 2 is used to drive the pitching action of the main arm 1. The main arm 1 is generally arranged on a slewing platform, and specifically, the first end arm section of the main arm 1 can be rotatably connected to the slewing platform. The first driving mechanism 2 can be, but is not limited to, a hydraulic cylinder.

[0054] The main arm 1 can be, but is not limited to, a six-stage telescopic arm. For an extra-long boom, a six-stage telescopic arm can be preferred.

[0055] In the specific implementation process, the main arm 1 is installed on the vehicle body 11 through a rotating platform, and can be installed at the tail of the vehicle body 11, the middle of the vehicle body 11, or the front of the vehicle body 11. Figure 1 The main arm 1 is installed at the rear of the vehicle body 11. When the arm device is in the folded state, the main arm 1 extends to the front end of the vehicle body 11, so that the main arm 1 is overlapped on the top of the cab of the vehicle body 11, which is beneficial to increase the length of a single arm section of the main arm 1, and can also ensure the extended length of the main arm 1 when the number of stages of the main arm 1 is small.

[0056] The offset arm is a folding arm, and the offset arm includes at least three arm sections, and the first end arm section of the offset arm is rotatably connected to the end arm section of the main arm 1, and the first end arm section of the offset arm is a telescopic arm or a folding arm. The second driving mechanism is used to drive the offset arm to switch between a folded state and an unfolded state.

[0057] In the folded state, the offset arms are located on the sides of the main arm 1, and the offset arms are stacked in at least three layers.

[0058] In this way, by setting the offset arm as a whole or partially in the structural form of a folding arm, a variable cross-section design of the offset arm is achieved, and there is no requirement for the overlapping length of each arm section of the folding arm part of the offset arm in the unfolded state, and there is basically no overlap, which is conducive to the lightweight design of the offset arm, reduces the lateral bending amount of the main arm 1, and is conducive to the stable operation of the fire truck.

[0059] In addition, the main arm 1 is configured as a telescopic arm structure, and after the main arm 1 is unfolded, it can provide a larger height for the offset arm. The offset arm is partially configured as a folding arm structure, so that the arm device has a larger span. The arm device in this embodiment has a stronger ability to cross obstacles.

[0060] It should be noted that the rotation axis of the main arm 1 relative to the slewing platform, the rotation axis of the offset arm relative to the main arm 1, and the rotation axis of each arm section of the offset arm relative to each other are parallel to each other and are parallel to the bearing surface of the vehicle body 11. Generally, when the vehicle body 11 is located on a horizontal plane, the bearing surface of the vehicle body 11 is arranged in the horizontal direction.

[0061] In this embodiment, along the distribution direction of the offset arm and the main arm 1, the projection area of ​​the offset arm is located inside the projection area of ​​the main arm 1 or the two overlap. The setting of the offset arm will not affect the height of the boom device in the folded state, which is conducive to realizing an ultra-long boom structure.

[0062] In this embodiment, the height of the upper edge of the offset arm is less than the height of the upper edge of the main arm 1, while the height of the lower edge of the offset arm is greater than the height of the lower edge of the main arm 1. In other words, the setting of the offset arm will not affect the overall height of the boom device, nor will it occupy the space below the horizontal plane where the lower edge of the main arm 1 is located. Specifically, when the boom device is in a folded state, each arm section of the offset arm can extend substantially in the horizontal direction.

[0063] There is ample space above the vehicle body 11 and below the main arm 1 and the offset arm, which can be used to lay out a water tank and ensure that the water tank has sufficient capacity. When used in a high-pressure fire truck, the fire-fighting efficiency and fire-fighting capability of the high-pressure fire truck can be greatly improved.

[0064] In the embodiment of the utility model, the offset arm includes three arm sections, namely the first arm section 3, the second arm section 4 and the third arm section 5. The first arm section 3, the second arm section 4 and the third arm section 5 are arranged in sequence, and two adjacent ones are connected in rotation. The folding and unfolding of the offset arm can be achieved by the rotation of the first arm section 3 relative to the main arm 1 and the rotation of two adjacent ones of the three arm sections of the offset arm.

[0065] When the offset arm is in a folded state, it is stacked in a three-layer structure, which can take into account the requirement that the full extension length of the offset arm is 30 to 40 meters and the requirement that the height of the entire vehicle is less than 4 meters.

[0066] The second driving mechanism includes a second driving member, a third driving member and a fourth driving member.

[0067] The second driving member is connected to the first arm section 3 and the end arm section of the main arm 1 , and the second driving member can be used to drive the first arm section 3 to rotate relative to the end arm section of the main arm 1 .

[0068] The third driving member is connected to the head ends of the first arm section 3 and the second arm section 4 , and the third driving member can be used to drive the second arm section 4 to rotate relative to the first arm section 3 .

[0069] The fourth driving member is connected to the head ends of the second arm section 4 and the third arm section 5 , and the third arm section 5 can be driven to rotate relative to the second arm section 4 by the fourth driving member.

[0070] The second driving member, the third driving member and the fourth driving member may be, but are not limited to, hydraulic cylinders and rotary motors.

[0071] In order to reduce the height dimension of the offset arm in the folded state as much as possible, it is necessary to increase the relative rotation angle range of adjacent arm sections as much as possible, so that when the offset arm is in the folded state, the adjacent arm sections are parallel to each other, and the arm sections of the offset arm are parallel to the axis of the main arm 1. The following is a specific description taking the second driving member as an example.

[0072] When a telescopic hydraulic cylinder is selected as the second driving member, the cylinder barrel of the telescopic hydraulic cylinder is arranged on the first boom section 3, and the piston rod of the telescopic hydraulic cylinder is connected to the end boom section of the main boom 1 through a connecting rod assembly. The connecting rod assembly can increase the rotation angle range of the first boom section 3 under the driving action of the second driving member, which is conducive to reducing the stroke requirement of the second driving member. The first boom section 3 can be driven to rotate within a range of 180 degrees relative to the main boom 1 through the second driving member.

[0073] It should be noted that the cylinder barrel and the piston rod of the telescopic hydraulic oil cylinder are two parts that can slide relative to each other, and no specific limitation is made here as long as one of them is connected to the first arm section 3 and the other is connected to the end arm section of the main arm 1. Moreover, whether the connecting rod assembly is set on the cylinder barrel of the telescopic hydraulic oil cylinder or on the piston rod of the telescopic hydraulic oil cylinder is not specifically limited.

[0074] When a rotary motor is selected as the second driving member, the rotary motor can be arranged at the rotation connection position between the first arm section 3 and the end arm section of the main arm 1. The rotary motor can drive the first arm section 3 to rotate in a large range relative to the end arm section of the main arm 1.

[0075] In some embodiments, when the offset arm is in the folded state, the third arm section 5 is located between the first arm section 3 and the second arm section 4. Figure 2 and Figure 3 When the bias arm switches to the folded state, it is necessary to first control the third arm section 5 to rotate relative to the second arm section 4, and then control the second arm section 4 to rotate relative to the first arm section 3. When the bias arm switches to the unfolded state, it is necessary to first control the second arm section 4 to rotate relative to the first arm section 3, and then control the third arm section 5 to rotate equivalent to the second arm section 4.

[0076] In some other embodiments, when the offset arm is in the folded state, the third arm section 5 is located on the side of the second arm section 4 away from the first arm section 3, as shown in FIG. Figures 4 to 7 When the biasing arm switches to the folded state and when the biasing arm switches to the unfolded state, the order in which the third arm section 5 rotates relative to the second arm section 4 and the second arm section 4 rotates relative to the first arm section 3 is not restricted.

[0077] In some embodiments, when the offset arm is in the unfolded state, the second drive member, the third drive member, the fourth drive member and each connecting rod assembly are located below the offset arm. With such an arrangement, when the offset arm is in the unfolded state, the second drive member, the third drive member and the fourth drive member are in a compressed state. When the second drive member, the third drive member and the fourth drive member use a telescopic hydraulic cylinder, the rodless chamber of the telescopic hydraulic cylinder bears pressure, the force is better, and the stability of the arm device is better.

[0078] In some other embodiments, when the biasing arm is in the expanded state, the second driving member, the third driving member, the fourth driving member and each connecting rod assembly are all located above the biasing arm.

[0079] In an embodiment of the utility model, the arm device also includes an end head 6, a first end of the end head 6 is connected to the end of the end arm section of the main arm 1, and a second end of the end head 6 extends along the distribution direction of the offset arm and the main arm 1. Specifically, the extension direction of the end head 6 is perpendicular to the axis of the main arm 1.

[0080] In some embodiments, the first end arm section of the offset arm is connected to the lower edge of the second end of the end 6, referring to Figure 2 , Figure 4 and Figure 6, the offset arm is in the folded state, and the second arm section 4 is located above the first arm section 3. In this arrangement, during the deployment of the boom device, the offset arm is located in front of the main arm 1, the center of gravity of the entire boom device is relatively forward, and the stability of the vehicle body 11 is relatively strong.

[0081] In some other embodiments, the first end arm section of the offset arm is connected to the upper edge of the second end of the end 6, referring to Figure 3 , Figure 5 and Figure 7 , the offset arm is in the folded state, and the second arm section 4 is located below the first arm section 3. In this way, during the deployment of the boom device, the main arm 1 can be controlled to move first, and the offset arm can be controlled to deploy first, which makes the control of the boom device more flexible.

[0082] In the embodiment of the utility model, the second arm section 4 includes a head end connection part 13, a tail end connection part 15 and a transition part 14 arranged between the head end connection part 13 and the tail end connection part 15, and the head end connection part 13, the transition part 14 and the tail end connection part 15 form an integrated structure.

[0083] The axis of the head end connection part 13 and the axis of the tail end connection part 15 are both parallel to the axis of the main arm 1. The distance between the axis of the head end connection part 13 and the axis of the main arm 1 is a first distance x, and the distance between the axis of the tail end connection part 15 and the axis of the main arm 1 is a second distance y. The first distance x is greater than the second distance y. Figure 8 .

[0084] It can be understood that there is an angle between the axis of the transition portion 14 and the axis of the main arm 1, and the axis of the transition portion 14 is inclined relative to the axis of the main arm 1. Along the direction from the head end to the tail end of the main arm 1, the distance between the axis of the transition portion 14 and the axis of the main arm 1 gradually decreases, and the second arm section 4 gradually approaches the main arm 1.

[0085] In this way, a space is reserved on the side of the second boom section 4 away from the main boom 1 for installing the water pipeline 12, which is beneficial to reducing the overall width of the boom device. It is also beneficial for the water pipeline 12 to be connected with a hard pipe, which can reduce pressure loss.

[0086] The width dimension of the entire boom device is the dimension of the entire boom device in the horizontal direction perpendicular to the axis of the main boom 1 .

[0087] In some embodiments of the present invention, the length of the end arm section 10 of the offset arm can be telescopically adjusted, such as Fig.10 As shown, by making the end arm section 10 of the offset arm telescopically adjustable, the flexibility of the arm support device can be improved. A firefighting water monitor is installed at the end of the end arm section 10 of the offset arm to increase the fire extinguishing range.

[0088] In other embodiments of the present invention, the end arm section 10 of the offset arm is arranged in a segmented structure, including a first section 7, a second section 8 and a fifth driving member 9, the first section 7 and the second section 8 are arranged in sequence along the direction from the head end to the end of the offset arm, and the second section 8 is rotatably connected to the first section 7, such as Fig.11 and Fig.12 The fifth driving member 9 is connected to the first section 7 and the second section 8 , and the fifth driving member 9 is used to drive the second section 8 to rotate relative to the first section 7 .

[0089] The flexibility of the arm device can also be improved by rotating the second section 8 relative to the first section 7. The fire-fighting water monitor is installed on the second section 8 to increase the fire-fighting range.

[0090] Similar to the above-mentioned second driving member, the fifth driving member 9 can be, but is not limited to, a telescopic hydraulic cylinder, a rotary motor, etc.

[0091] In a further embodiment, the second section 8 can also be configured as a structure whose length can be adjusted telescopically, such as Fig.12 As shown, the flexibility of the boom device and the fire extinguishing range can be further improved.

[0092] It should be noted that the boom device in this embodiment is not limited to application to fire trucks, but can also be applied to cranes, aerial work vehicles, etc.

[0093] On the other hand, the embodiment of the utility model further provides a fire truck, comprising the arm device provided in any of the above embodiments. The arm device provided in any of the above embodiments is conducive to lightweight design, and the lateral bending amount of the main arm 1 is small. Therefore, the fire truck in this embodiment has strong stability. The derivation process of the beneficial effects of the fire truck in the embodiment of the utility model is generally similar to the derivation process of the beneficial effects of the above arm device, so it will not be repeated here.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A boom device, characterized in that: include: A main arm, wherein the main arm is a telescopic arm; A first driving mechanism, adapted to drive the pitching action of the main arm; An offset arm, the offset arm comprising at least three arm sections, the first end arm section of the offset arm being rotatably connected to the last end arm section of the main arm, the first end arm section of the offset arm being a telescopic arm or a folding arm; a second driving mechanism, adapted to drive the biasing arm to switch between a folded state and an unfolded state; Wherein, in the folded state, the offset arm is located on the side of the main arm, and the offset arms are stacked in at least three layers.

2. The boom device according to claim 1, characterized in that: Along the distribution direction of the offset arm and the main arm, the projection area of ​​the offset arm is located inside the projection area of ​​the main arm or the projection area of ​​the offset arm overlaps with the projection area of ​​the main arm.

3. The arm device according to claim 1, characterized in that: The biasing arm comprises: The first arm section, the second arm section and the third arm section are arranged in sequence and the adjacent two are rotatably connected; The second driving mechanism comprises: A second driving member is connected to the first arm section and the end arm section of the main arm respectively; a third driving member, connected to the head ends of the first arm section and the second arm section respectively; The fourth driving member is connected to the head ends of the second arm section and the third arm section respectively.

4. The arm device according to claim 3, characterized in that: When the biasing arm is in a folded state, the third arm section is located between the first arm section and the second arm section; Alternatively, when the biasing arm is in the folded state, the third arm section is located on a side of the second arm section away from the first arm section.

5. The boom device according to claim 3, characterized in that: Also includes: An end head, wherein a first end of the end head is connected to an end of an end arm section of the main arm, and a second end of the end head extends along a distribution direction of the offset arm and the main arm; The first end arm section of the offset arm is connected to the lower edge of the second end of the end head, and when the offset arm is in a folded state, the second arm section is located above the first arm section; or, the first end arm section of the offset arm is connected to the upper edge of the second end of the end head, and when the offset arm is in a folded state, the second arm section is located below the first arm section.

6. The boom device according to claim 3, characterized in that: The second arm section includes a head end connection portion, a tail end connection portion, and a transition portion arranged between the head end connection portion and the tail end connection portion, wherein the head end connection portion, the transition portion, and the tail end connection portion form an integrated structure; The axis of the head end connecting part and the axis of the tail end connecting part are both parallel to the axis of the main arm, the distance between the axis of the head end connecting part and the axis of the main arm is a first distance, and the distance between the axis of the tail end connecting part and the axis of the main arm is a second distance, and the first distance is greater than the second distance.

7. The boom device according to claim 1, characterized in that: The length of the end arm section of the offset arm can be telescopically adjusted.

8. The boom device according to claim 1, characterized in that: The end arm section of the offset arm comprises: The first section and the second section are rotatably connected; A fifth driving member is connected to the first section and the second section respectively, and the fifth driving member is suitable for driving the second section to rotate relative to the first section.

9. The boom device according to claim 8, characterized in that: The length of the second section can be telescopically adjusted.

10. A fire truck, characterized in that: Comprising the arm device according to any one of claims 1 to 9.

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