CN207108310U - Boom system and crane - Google Patents

Abstract

The utility model relates to a jib system and a crane, wherein the jib system includes a base, a main arm, an auxiliary arm, a first luffing mechanism and a second luffing mechanism; the first luffing mechanism is driven and connected to the main arm, and the second A luffing mechanism can drive the main arm to rotate forward relative to the base and place it above the base. The second luffing mechanism is connected to the auxiliary arm by driving. The second luffing mechanism can drive the auxiliary arm to rotate backward relative to the main arm and place it on the above the main arm. The utility model can place the main arm and the auxiliary arm at the hoisting position through the first luffing mechanism and the second luffing mechanism; it can also retract the main arm and place it above the base, and retract the auxiliary arm and place it above the main arm for transportation. There is no need to remove the jib, reducing transportation costs, and after arriving at the construction site, there is no need to use an auxiliary vehicle to install the jib, reducing the installation cost of the jib; moreover, the retraction of the main arm and the jib will not be too long beyond the outside of the car body , can balance the bridge load of the whole car body and improve the safety of driving.

Description

Boom system and crane

technical field

The utility model relates to the field of engineering machinery, in particular to an arm support system and a crane.

Background technique

With the development of construction machinery, the market competition is becoming increasingly fierce. In order to obtain higher profits and enhance the competitiveness of products, the transportation and use costs of cranes are also key factors to measure the quality of cranes.

As shown in Figure 1, the jib system of the existing crane includes the main arm 1', the auxiliary arm 2', the luffing mechanism 3', the pulley block 4', the front support 6', the rear support 7', the first pull plate 8', the second pull plate 9' and the luffing cylinder 12'. The first end of the main arm 1' is set on the turntable of the crane, the second end of the main arm 1' is connected to the first end of the auxiliary arm 2', the first end of the front support 6' and the first end of the rear support 7' are both Connect the first end of the auxiliary arm 2', the second end of the front bracket 6' connects the second end of the rear bracket 7' through the first pull plate 8', and the second end of the front bracket 6' through the second pull plate 9' Attach the second end of the jib 2'. The pulley block 4' is arranged on the rear bracket 7', and the luffing mechanism 3' is installed on the upper turntable, located in the middle of the balance weight, and the luffing mechanism 3' is connected to the pulley block 4' through the wire rope 5'. Lifting cab 10' is positioned at the top loading turntable away from the side of the traveling cab 11', and the traveling cab 11' is located at the front of the chassis (consistent with the forward direction of the normal traveling state of the crane). The luffing hoisting mechanism 3' is close to the driving cab 11' relative to the main arm 1'. The first end of the luffing cylinder 12' is hinged on the turntable in front of the lifting cab 10' (opposite to the front direction of the normal running state of the crane), and the second end of the luffing cylinder 12' is hinged on the main arm 1'.

When the crane is hoisting, operate the luffing cylinder 12' to make the main arm 1' luff up to a certain angle, and then operate the luffing hoisting mechanism 3' to rotate, so that the wire rope is wound on the luffing hoisting mechanism 3', and the wire rope 5' Pull the rear bracket 7' to rotate to the rear side of the main arm 1' through the pulley block 4', and pull the auxiliary arm 2' through the connection of the first pull plate 8', the front bracket 6', the second pull plate 9' and the auxiliary arm 2' The second end moves upward to realize hoisting.

In the jib system of the above-mentioned crane, the auxiliary arm 2' is installed at the second end of the main arm 1', and the part beyond the front of the lifting cab 10' (opposite to the front direction in the normal driving state of the crane) is too long, and the auxiliary arm 2' is heavy, and after it is connected to the second end of the main boom 1', the bridge load on the crane's part of the axle will become very large, making it unsafe to drive on the road. Therefore, in order to avoid uneven bridge load and over-length constraints, Before driving on the road, the jib 2' needs to be removed, and the jib 2' is transported to the work site by a trolley, and then the auxiliary vehicle is used to lift the jib 2' and install it on the second end of the main jib 1' for hoisting work. This leads to higher transportation and installation costs of the vehicle, which reduces the competitiveness of the product.

The technical terms involved in the utility model are explained below.

Jib: The structure is a lattice arm or a box arm, which is connected to the jib head of the main arm of the crane and used to raise the working height of the crane.

Luffing hoisting mechanism: It is composed of luffing winch and corresponding bracket. Through the rotation of luffing winch, the steel wire rope pulls the jib to realize jib luffing.

Pulley block: It is composed of multiple pulleys. Through the connection of multiple pulleys, the pulling force acting on the auxiliary arm can be reduced.

Axle load: The load acting on the axle.

Utility model content

The purpose of the utility model is to provide a jib system and a crane, wherein the jib system can reduce transportation costs and improve transportation safety.

In order to achieve the above purpose, the utility model provides a jib system, which includes a base, a main arm, an auxiliary arm, a first luffing mechanism and a second luffing mechanism; the first luffing mechanism is drivingly connected to the The main arm, the first luffing mechanism can drive the main arm to rotate forward relative to the base and place it above the base, the second luffing mechanism is drivingly connected to the auxiliary arm, the first The second luffing mechanism can drive the auxiliary arm to rotate backward relative to the main arm and to be placed above the main arm.

In a preferred or optional embodiment, the first end of the main arm is hinged to the base, the second end of the main arm is hinged to the first end of the auxiliary arm, and the second end of the auxiliary arm is end is used for hoisting; the first end of the first luffing mechanism is connected to the base, the second end of the first luffing mechanism is connected to the main arm; and the first end of the first luffing mechanism One end is located in front of the first end of the main arm.

In a preferred or optional embodiment, the first luffing mechanism includes a first oil cylinder, the first end of the first oil cylinder is hinged to the base, and the second end of the first oil cylinder is hinged to the main arm.

In a preferred or optional embodiment, the first end of the second amplitude-changing mechanism is connected to the main arm, and the second end of the second amplitude-changing mechanism is connected to the auxiliary arm.

In a preferred or optional embodiment, the second luffing mechanism includes a first support, a second oil cylinder and a lifting mechanism, the first support is connected to the main arm, and the second oil cylinder is drivingly connected to The first bracket can drive the first bracket to extend/retract relative to the main arm, the lifting mechanism is arranged on the first bracket, and the lifting mechanism is connected to the auxiliary arm through a wire rope the lifting end.

In a preferred or optional embodiment, the first end of the second oil cylinder is hinged to the main arm, the second end of the second oil cylinder is hinged to the first bracket, and the first end of the first bracket One end is hinged to the main arm.

In a preferred or optional embodiment, the main arm includes a basic arm and a multi-section telescopic arm, and the first end of the first bracket is hinged to the end of the basic arm.

In a preferred or optional embodiment, the second luffing mechanism includes a first pull plate, the first end of the first pull plate is hinged to the main arm, and the second end of the first pull plate Hinged to the first bracket.

In a preferred or optional embodiment, the second luffing mechanism includes a second bracket, a pulley block and a second pull plate, the second bracket is connected to the main arm, and the second bracket passes through the first The two pull plates are connected to the auxiliary arm, the pulley block is arranged on the second bracket, and the wire rope of the lifting mechanism goes around the pulley block.

In a preferred or optional embodiment, the first end of the second bracket is hinged to the main arm, the first end of the second pull plate is hinged to the second bracket, and the second pull plate The second end of is connected to the hoisting end of the auxiliary arm.

In a preferred or optional embodiment, the main arm includes a basic arm and a multi-section telescopic arm, and the first end of the second bracket is hinged to the end of the last telescopic arm.

In a preferred or optional embodiment, the second luffing mechanism further includes a third oil cylinder, the first end of the third oil cylinder is hinged to the auxiliary arm, and the second end of the third oil cylinder is hinged to the second bracket.

In a preferred or optional embodiment, the boom system includes a positioning device. When the first luffing mechanism drives the main arm to rotate relative to the base to be perpendicular to the base, the positioning device is used to The main arm is positioned with the base.

To achieve the above purpose, the utility model provides a crane, which includes the jib system in any one of the above embodiments.

In a preferred or optional embodiment, the crane includes a driving cab and a lifting cab, the driving cab and the lifting cab are respectively located at two ends of the crane, and the first luffing mechanism and The connecting end of the base is closer to the driving cab relative to the connecting end of the main arm and the base.

Based on the above technical solution, the utility model has at least the following beneficial effects:

The jib system provided by the embodiment of the utility model can make the main arm and the auxiliary arm at the hoisting position through the first luffing mechanism and the second luffing mechanism for hoisting; it can also be hoisted through the first luffing mechanism and the second luffing mechanism The mechanism allows the main arm to be retracted and placed above the base, and the auxiliary arm to be retracted and placed above the main arm for transportation without the need to remove the auxiliary arm, reducing transportation costs, and after arriving at the construction site, there is no need to use an auxiliary vehicle to install the auxiliary arm. Through the luffing mechanism, the jib luffing can be placed in the hoisting position, reducing the transportation and installation costs of the jib; moreover, the retraction of the main arm and the jib will not be too long beyond the outside of the car body, which can balance the bridge load of the entire car body, Improve driving safety.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the utility model and constitute a part of the utility model. The schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an improper limitation of the utility model . In the attached picture:

Fig. 1 is the schematic diagram of the jib system of existing large-tonnage crane;

Fig. 2 is a schematic diagram of the retracted state of the boom system provided by the embodiment of the present invention;

Fig. 3 is a schematic diagram of the initial deployment state of the boom system provided by the embodiment of the present invention;

Fig. 4 is a schematic diagram of the fully expanded state of the boom system provided by the embodiment of the present invention.

Labels in the attached drawings:

1'-Main arm; 2'-Jib; 3'-Luffing hoisting mechanism; 4'-Pulley block; 5'-Wire rope; 6'-Front support; 7'-Rear support; 8'-First pull plate ;9'-the second pull plate; 10'-lifting cab; 11'-traveling cab; 12'-luffing cylinder;

1 - Base;

2 - main arm;

3 - auxiliary arm;

4- the first luffing mechanism;

5-second luffing mechanism; 51-first bracket; 52-second oil cylinder; 53-hoisting mechanism; 531-wire rope; 54-first pull plate; 55-second bracket; The second pull plate; 58- the third oil cylinder;

6- driving cab;

7- Lifting cab.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

In describing the present invention, it should be understood that the terms "central", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal" , "top", "bottom", "inner", "outer" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, rather than indicating 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 construed as limiting the protection scope of the present utility model.

It should be noted that "front" in the utility model refers to the normal driving direction of the crane, and "rear" refers to the reverse direction of the normal driving direction of the crane, or when a driving cab and a lifting cab are arranged at both ends of the crane, "Front" refers to the direction from the lifting cab to the driving cab, and "rear" refers to the direction from the driving cab to the lifting cab.

As shown in Figures 2 to 4, it is a schematic embodiment of the boom system provided by the utility model. In this schematic embodiment, the boom system includes a base 1, a main boom 2, an auxiliary boom 3, a first luffing Mechanism 4 and the second luffing mechanism 5.

The first amplitude-changing mechanism 4 is drivingly connected to the main arm 2. The first amplitude-changing mechanism 4 is used to drive the main arm 2 to rotate relative to the base 1. The first amplitude-changing mechanism 4 can drive the main arm 2 to rotate relative to the base 1. In the hoisting position, the first luffing mechanism 4 can also drive the main arm 2 to rotate forward relative to the base 1 and put it on the base 1 .

The second luffing mechanism 5 is drivingly connected to the auxiliary arm 3, the second luffing mechanism 5 is used to drive the auxiliary arm 3 to rotate relative to the main arm 2, and the second luffing mechanism 5 can drive the auxiliary arm 3 relative to the main arm 2 The rotation is located at the hoisting position, and the second luffing mechanism 5 can also drive the auxiliary arm 3 to rotate backward relative to the main arm 2 and place it above the main arm 2 .

The jib system provided by the above-mentioned embodiments of the present invention can make the main arm 2 and the auxiliary arm 3 in the hoisting position through the first luffing mechanism 4 and the second luffing mechanism 5 for hoisting; it can also be hoisted through the first luffing mechanism 4 and the second luffing mechanism 5 make the main arm 2 retracted and placed above the base 1, and the auxiliary arm 3 retracted and placed above the main arm 2 for transportation without removing the auxiliary arm 3, which reduces transportation costs and can be placed on the crane After arriving at the construction site, there is no need to use an auxiliary vehicle to install the jib 3, and the luffing mechanism can make the jib 3 swing in the hoisting position, reducing the transportation and installation costs of the jib 3; The direction of rotation is retracted above the base 1, and the auxiliary arm 3 is rotated in the direction of the lifting cab 7 and retracted above the main arm 2, so that the main arm 2 and auxiliary arm 3 will not exceed the direction of the lifting cab 7 and the driving cab 6 If the part is too long, it can balance the bridge load of the large-tonnage crane, improve the safety of driving, and enhance the competitiveness of the crane.

In the boom system provided by the embodiment of the utility model, the first end of the main arm 2 can be hinged to the base 1, the second end of the main arm 2 can be hinged to the first end of the auxiliary arm 3, and the second end of the auxiliary arm 3 can be used for For hoisting; the first end of the first luffing mechanism 4 can be connected to the base 1, and the second end of the first luffing mechanism 4 can be connected to the main arm 2; and the first end of the first luffing mechanism 4 is located on the main arm 2 in front of the first end (the first end of the first luffing mechanism 4 is closer to the driving cab 6 relative to the first end of the main arm 2).

In a preferred or optional embodiment, the first luffing mechanism 4 may include a first oil cylinder, the first end of the first oil cylinder may be hinged to the base 1 , and the second end of the first oil cylinder may be hinged to the main arm 2 .

In the jib system provided by the embodiment of the present invention, the first end of the second luffing mechanism 5 can be connected to the main arm 2 , and the second end of the second luffing mechanism 5 can be connected to the sub-arm 3 .

In the above embodiment of the boom system, the second luffing mechanism 5 may include a first bracket 51, a second oil cylinder 52 and a lifting mechanism 53, the first end of the first bracket 51 may be connected to the main arm 2, and the second The oil cylinder 52 can be driven and connected to the first support 51, the second oil cylinder 52 can drive the first support 51 to extend/retract relative to the main arm 2, and the lifting mechanism 53 is arranged between the first end and the second end of the first support 51 Between the positions, the hoisting mechanism 53 is connected to the hoisting end of the jib 3 (the jib head of the jib 3 is also the second end of the jib 3 ) through a wire rope 531 .

In a preferred or optional embodiment, the second luffing mechanism 5 may include two first brackets 51 and two second oil cylinders 52 , and the two first brackets 51 are respectively arranged on two sides of the main arm 2 . The two first brackets 51 are correspondingly driven by a second oil cylinder 52 and can be rotated and extended relative to the main arm 2 , and can also be rotated and retracted at both sides of the main arm 2 .

In a preferred or optional embodiment, the first end of the second oil cylinder 52 can be hinged at the position between the first end and the second end of the main arm 2, and the second end of the second oil cylinder 52 is hinged at the first bracket The first end of the first bracket 51 is hinged to the main arm 2 at the position between the first end and the second end of the first bracket 51 .

Further, the main arm 2 may include a basic arm and a multi-section telescopic arm, the first end of the first bracket 51 may be hinged to the second end of the basic arm, and the first end of the basic arm is hinged to the base 1 .

In the above embodiment of the boom system, the second luffing mechanism 5 may further include a first pull plate 54, the first end of the first pull plate 54 is hinged to the first end of the main arm 2, and the first end of the first pull plate 54 The second end is hinged to the second end of the first bracket 51 .

In the above embodiment of the boom system, the second luffing mechanism 5 may also include a second bracket 55, a pulley block 56 and a second pull plate 57, the second bracket 55 is connected to the main arm 2, and the second bracket 55 passes through the second The pulling plate 57 is connected to the auxiliary arm 3 , the pulley block 56 is arranged at the second end of the second bracket 55 , and the wire rope 531 of the lifting mechanism 53 bypasses the pulley block 56 . After the wire rope 531 of the hoisting mechanism 53 is wound around the hoisting mechanism 53, stretch out a certain length and walk around the pulley block 56 and get back on the hoisting mechanism 53 and fix it.

In a preferred or optional embodiment, the first end of the second bracket 55 is hinged to the second end of the main arm 2, the first end of the second pull plate 57 is hinged to the second end of the second bracket 55, and the second The second end of the pull plate 57 is connected to the hoisting end of the auxiliary arm 3 (arm head of the auxiliary arm 3 ).

Further, the main arm 2 may include a basic arm and a multi-section telescopic arm, and the first end of the second bracket 55 is hinged to the end of the last telescopic arm. Alternatively, the first end of the second bracket 55 is hinged to the first end of the auxiliary arm 3 (the arm tail of the auxiliary arm 3 and the arm head of the auxiliary arm 3 are used for hoisting, which is the hoisting part).

In the above-mentioned embodiment of the boom system, the second luffing mechanism 5 may further include a third oil cylinder 58, and the first end of the third oil cylinder 58 may be hinged at the position between the first end and the second end of the auxiliary arm 3 , the second end of the third oil cylinder 58 is hinged to the position between the first end and the second end of the second bracket 55 .

In the above-mentioned embodiment of the boom system, the boom system may also include a positioning device. When the first luffing mechanism 4 drives the main arm 2 to rotate relative to the base 1 to be perpendicular to the base 1, the positioning device is used to position the main arm 2 Align with base 1.

The operation method of the boom system provided by the embodiment of the utility model is as follows:

1) Operate the first luffing mechanism 4 to make the main arm 2 go up to a certain angle; 2) Operate the second oil cylinder 52 in the second luffing mechanism 5 to drive the first bracket 51 to extend relative to the main arm 2; 3 ) Operate the hoisting mechanism 53 to rotate, wind the wire rope 531, pull the second bracket 55 to rotate counterclockwise and extend relative to the main arm 2 through the pulley block 56;

The jib system provided by the embodiment of the utility model can carry the jib 3 for transportation, so there is no need to use an auxiliary vehicle to install the jib 3 .

The jib system provided by the embodiment of the utility model is suitable for cranes, especially for large-tonnage cranes.

The utility model also provides a schematic embodiment of a crane. In this schematic embodiment, the crane includes the jib system in any one of the above embodiments.

The base 1 in the jib system is fixed on the top turntable of the crane, or the base 1 in the jib system is set as the top turntable of the crane.

The boom system provided by the above-mentioned embodiment of the present invention can include a driving cab 6 and a lifting cab 7, and the driving cab 6 and the lifting cab 7 can be respectively located at two ends of the crane. The first luffing mechanism 4 The connection end with the base 1 is closer to the driving cab 6 than the connection end between the main arm 2 and the base 1 .

The crane provided by the embodiment of the utility model can carry the auxiliary arm 3 when driving, the main arm 2 is rotated counterclockwise and placed above the frame of the crane, the auxiliary arm 3 is placed on the main arm 2 after clockwise rotation, and the auxiliary arm 2 can be placed The arm 3 is connected with the tail of the crane to provide the safety of the crane when traveling.

In the crane provided by the embodiment of the utility model, the auxiliary arm 3 is placed on the upper side of the main arm 2 for transportation, which avoids the limitation of the super length of the crane, and at the same time distributes the weight of the auxiliary arm 3 to all the axles of the crane, thus balancing The bridge load of the crane avoids the problem of inability to travel due to uneven bridge load.

The crane provided by the embodiment of the utility model, by sequentially operating the main arm 2, the luffing mechanism and the lifting mechanism 53 of the crane, realizes the luffing of the jib 3, and can carry the jib 3 for transportation without using an auxiliary vehicle to install the jib 3. Avoid the cost of using auxiliary vehicles, create more benefits for users, and enhance the competitiveness of products.

In the description of the present utility model, it should be understood that the use of words such as "first", "second", and "third" to define components is only for the convenience of distinguishing the above components, and if there is no other statement , the above-mentioned words have no special meaning, and therefore cannot be interpreted as limiting the protection scope of the present utility model.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model and not limit it; although the utility model has been described in detail with reference to the preferred embodiment, those of ordinary skill in the art should understand that: still The specific implementation of the utility model can be modified or some technical features can be equivalently replaced; without departing from the spirit of the technical solution of the utility model, all of them should be included in the scope of the technical solution claimed by the utility model.

Claims (15)

1. A boom system, characterized in that: comprising a base (1), a main arm (2), an auxiliary arm (3), a first luffing mechanism (4) and a second luffing mechanism (5); said The first amplitude-changing mechanism (4) is drivingly connected to the main arm (2), and the first amplitude-changing mechanism (4) can drive the main arm (2) to rotate and retract relative to the base (1) forward Placed above the base (1), the second luffing mechanism (5) is drivingly connected to the auxiliary arm (3), and the second luffing mechanism (5) can drive the auxiliary arm (3) It is rotated backward relative to the main arm (2), retracted and placed above the main arm (2). 2. The boom system according to claim 1, characterized in that: the first end of the main arm (2) is hinged to the base (1), and the second end of the main arm (2) is hinged to The first end of the auxiliary arm (3), the second end of the auxiliary arm (3) is used for hoisting; the first end of the first luffing mechanism (4) is connected to the base (1), The second end of the first luffing mechanism (4) is connected to the main arm (2); and the first end of the first luffing mechanism (4) is located at the first end of the main arm (2). front of the end. 3. The boom system according to claim 1, characterized in that: the first luffing mechanism (4) comprises a first oil cylinder, the first end of the first oil cylinder is hinged to the base (1), The second end of the first oil cylinder is hinged to the main arm (2). 4. The boom system according to claim 1, characterized in that: the first end of the second luffing mechanism (5) is connected to the main arm (2), and the second luffing mechanism (5) ) is connected to the secondary arm (3) at the second end. 5. The boom system according to claim 1, characterized in that: the second luffing mechanism (5) comprises a first bracket (51), a second oil cylinder (52) and a lifting mechanism (53), the The first bracket (51) is connected to the main arm (2), and the second oil cylinder (52) is drivingly connected to the first bracket (51), capable of driving the first bracket (51) relative to the The main arm (2) is extended/retracted, the lifting mechanism (53) is arranged on the first bracket (51), and the lifting mechanism (53) is connected to the auxiliary arm ( 3) The hoisting end. 6. The boom system according to claim 5, characterized in that: the first end of the second oil cylinder (52) is hinged to the main arm (2), and the second end of the second oil cylinder (52) The first end of the first bracket (51) is hinged to the first bracket (51), and the first end of the first bracket (51) is hinged to the main arm (2). 7. The boom system according to claim 6, characterized in that: the main arm (2) comprises a basic arm and a multi-section telescopic arm, and the first end of the first bracket (51) is hinged to the basic arm. end of the arm. 8. The boom system according to claim 5, characterized in that: the second luffing mechanism (5) comprises a first pull plate (54), and the first end of the first pull plate (54) is hinged On the main arm (2), the second end of the first pull plate (54) is hinged to the first bracket (51). 9. The boom system according to claim 5, characterized in that: the second luffing mechanism (5) comprises a second bracket (55), a pulley block (56) and a second pull plate (57), the The second bracket (55) is connected to the main arm (2), the second bracket (55) is connected to the auxiliary arm (3) through the second pull plate (57), and the pulley block (56) It is arranged on the second bracket (55), and the wire rope (531) of the lifting mechanism (53) goes around the pulley block (56). 10. The boom system according to claim 9, characterized in that: the first end of the second bracket (55) is hinged to the main arm (2), and the first end of the second pull plate (57) One end is hinged to the second bracket (55), and the second end of the second pull plate (57) is connected to the lifting end of the auxiliary arm (3). 11. The boom system according to claim 10, characterized in that: the main boom (2) includes a basic boom and a multi-section telescopic boom, and the first end of the second bracket (55) is hinged to the last section the end of the telescopic arm. 12. The boom system according to claim 9, characterized in that: the second luffing mechanism (5) further comprises a third oil cylinder (58), and the first end of the third oil cylinder (58) is hinged on The secondary arm (3), the second end of the third oil cylinder (58) is hinged to the second bracket (55). 13. The boom system according to claim 1, characterized in that it includes a positioning device, and the first luffing mechanism (4) drives the main arm (2) to rotate relative to the base (1) to When perpendicular to the base (1), the positioning device is used to position the main arm (2) and the base (1). 14. A crane, characterized in that it comprises the jib system according to any one of claims 1-13. 15. The crane according to claim 14, characterized in that: comprising a driving cab (6) and a lifting cab (7), the driving cab (6) and the lifting cab (7) are respectively Located at both ends of the crane, the connecting end of the first luffing mechanism (4) and the base (1) is closer to the connecting end of the main arm (2) and the base (1) Travel cab (6).