Boom lifting method and crane

Abstract

The invention discloses an arm lifting method of an arm support and a crane, the arm support comprises a telescopic main arm and an auxiliary arm formed by splicing a plurality of sections, the main arm and the auxiliary arm are connected through a plurality of hinge points, and every two adjacent sections are connected through a plurality of hinge points. The arm lifting method comprises the following steps: disconnecting an upper hinge point between a main arm and an auxiliary arm or between two adjacent sections of the auxiliary arm, enabling part of the sections of the auxiliary arm to form a delayed variable-amplitude section which does not synchronously change amplitude with the main arm, connecting the front section of the delayed variable-amplitude section with the main arm after the amplitude of the main arm is changed to a certain angle, driving the main arm to extend out, and lifting the main arm. And the delay variable-amplitude section forming a certain included angle with the main arm is pushed to straighten. The main arm is used as driving force, so that the delayed variable-amplitude section is restored to be straight, the driving force is improved, the length of the auxiliary arm capable of being pulled up is increased, and the arm lifting length is greatly increased on the premise that the specification of the oil cylinder is not changed.

Description

Technical Field

[0001] The present invention relates to a luffing method, in particular to a method for raising the boom, and also relates to a crane. Background Art

[0002] When a truck crane is operating, the main load-bearing component is the boom system, and the boom system generally includes a main boom and a jib. For super-large-tonnage cranes, to achieve a larger lifting height and lifting capacity, corresponding boom lengths and performances are required. Limited by the length of the main boom, only the method of increasing the length of the jib can be adopted. As the length of the jib increases, the self-weight of the jib also increases, and the load required by the luffing cylinder increases during horizontal boom raising. However, limited by the overall machine space layout such as the overall width or the overall weight of the machine, the luffing cylinder cannot be made larger in size to provide greater boom-raising power, resulting in the inability to raise the boom normally.

[0003] The invention patent application with the publication number CN 114684728 A discloses a method for raising an ultra-long boom. The upper hinge point of the front section 4' of the jib is disengaged, and the boom tip 9 does not leave the ground until the luffing reaches a certain angle. Then, the superlift is used to pull up the pre-disengaged section, and the disengaged hinge point is restored. In the current solution, Figure 1 using the superlift winch as the driving force, the maximum gravity moment of the disengaged section 4' needs to be less than the minimum moment of the superlift winch, otherwise it cannot be pulled up. The superlift pulling force is small, and the length of the jib that can be pulled up is limited; when the section 4' is disengaged, the luffing angle of the jib driven by the luffing cylinder is related to the length of the section 4'. The smaller the length of the section 4', the smaller the luffing angle of the main boom driven by the luffing cylinder, and the contribution to reducing the luffing force is small.

[0004] In the case where the front section is disengaged, only the superlift holds it. The length of the superlift cable is long, and it is difficult to balance the self-weight hanging force of the cable or the pull plate and the gravity of the disengaged part of the front section, resulting in an unstable boom-raising process. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a method for raising the boom to solve the problem that the disengaged length of the jib is limited by the force of the superlift mechanism.

[0006] Technical Solution: In the method for raising the boom of the present invention, the boom includes a telescopic main boom and a jib formed by splicing several sections. Between the main boom and the jib, and between two adjacent sections, they are connected by a plurality of hinge points. The method for raising the boom is as follows: Disconnect the upper hinge point between the main boom and the jib, or between two adjacent sections of the jib, so that a part of the jib forms a delayed luffing section that luffs out of sync with the main boom. The main boom luffs to a certain angle, connect the front section of the delayed luffing section and the main boom, drive the main boom to extend, and push the delayed luffing section that forms a certain angle with the main boom to straighten.

[0007] Preferably, the included angle α formed between the delayed amplitude-changing section and the main boom ranges from 90 < α < 180°.

[0008] Preferably, the front section of the delayed amplitude-changing section is connected to the main boom, and the delayed amplitude-changing section can change its amplitude synchronously with the main boom.

[0009] Preferably, the front section of the delayed amplitude-changing section is connected to the main boom. The delayed amplitude-changing section changes its amplitude synchronously with the main boom, continues to change its amplitude to the working angle, the arm section of the main boom extends, and the delayed amplitude-changing section is pushed to straighten.

[0010] Preferably, a super-lifting mechanism is provided on the main boom. The front section of the delayed amplitude-changing section is connected to the hoist of the super-lifting mechanism. When connecting the front section of the delayed amplitude-changing section to the main boom, the hoist of the super-lifting mechanism is self-locked.

[0011] Preferably, the super-lifting mechanism and the auxiliary boom are connected by a cable, and a mast for supporting the cable is provided on the auxiliary boom.

[0012] Preferably, the disconnected hinge point is located between the main boom and the mast.

[0013] Preferably, after the delayed amplitude-changing section is straightened, the disconnected hinge point is restored.

[0014] A crane adopting the aforementioned boom erection method.

[0015] Preferably, a buffer is provided between the main boom and the auxiliary boom, or between two adjacent segments of the auxiliary boom. When the hinge point is disconnected, the buffer extends.

[0016] Preferably, a switch for detecting whether the hinge point is aligned and detecting the insertion of the shaft is provided on the hinge point.

[0017] Advantageous effects: Compared with the prior art, the present invention has the following remarkable advantages: 1. Increasing the disconnected length of the auxiliary boom: The front section of the delayed amplitude-changing section is connected to the main boom, and the main boom extends, acting as a driving force to make the delayed amplitude-changing section restore to straighten, improving the driving force, increasing the length of the auxiliary boom that can be pulled up, and greatly increasing the erection length without changing the cylinder specifications; 2. The super-lifting mechanism, as a common external attachment structure of the crane, can realize the connection between the delayed amplitude-changing section and the main boom by self-locking, improving the pulling force that can lift the auxiliary boom, without the need to introduce other devices additionally, and can also realize the angle adjustment between the delayed amplitude-changing section and the main boom; 3. Using the mast to support the cable, when the delayed amplitude-changing section is formed, the mast rotates with the disconnected part of the auxiliary boom, increasing the moment formed by the cable, and thus can increase the length of the disconnected auxiliary boom, and can complete the self-erection of a longer boom; 4. Adding a buffer makes the boom erection process smoother. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the boom erection method in the prior art;

[0019] Figure 2 Schematic diagram of the crane structure according to an embodiment of the present invention;

[0020] Figure 3 Schematic diagram of the structure where the main boom and the auxiliary boom form a certain angle according to an embodiment of the present invention;

[0021] Figure 4 Schematic diagram of the structure where the auxiliary boom varies with the main boom according to the second embodiment of the present invention;

[0022] Figure 5 Schematic diagram of the structure where the auxiliary boom is straightened according to the second embodiment of the present invention;

[0023] Figure 6 is Figure 4 Enlarged view of part A in;

[0024] Figure 7 Schematic diagram of the hinge point structure;

[0025] Figure 8 is Figure 5 Enlarged view of part B in;

[0026] Figure 9 is Figure 8 Cross-sectional view taken along the A - A direction in;

[0027] Figure 10 Schematic diagram of the initial force arm of the luffing cylinder;

[0028] Figure 11 Schematic diagram of the force arm of the luffing cylinder when luffed to a certain angle;

[0029] Figure 12 Schematic diagram of the maximum force arm of the luffing cylinder according to an embodiment of the present invention;

[0030] Figure 13 Schematic diagram of the structure according to the third embodiment of the present invention. Detailed implementation manners

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0032] Embodiment 1: This embodiment provides a method for raising the boom of a crane. Among them, as Figure 2 , the crane mainly consists of a vehicle body 8 and a boom. The vehicle body 8 is used for transferring the site. The boom includes a main boom 2, an auxiliary boom 4, a boom head 9, and a luffing cylinder 1 for driving the main boom 2 to luff. The main boom 2 is formed by sleeving a plurality of cylindrical boom sections with gradually decreasing radii. The cylindrical boom sections can be telescoped to reach different lengths. The bottom of the main boom 2 is rotatably connected to the vehicle body 8, and the top is connected to the auxiliary boom 4 through a plurality of hinge points. By disconnecting the hinge points at the upper or lower part of the main boom 2 and the auxiliary boom 4, the auxiliary boom 4 can rotate around the main boom 2 to form a certain angle.

[0033] The auxiliary arm 4 is an additional device added to increase the lifting height. It is composed of several truss structure segments. By changing the number of segments, different lengths can be formed. The end faces of two adjacent segments are connected by multiple hinge points. By disconnecting the hinge points at the upper or lower parts of the two adjacent segments, the two adjacent segments can rotate relative to each other to form a certain angle.

[0034] like Figures 2 to 5 , Figure to Figure 10 , the arm raising method is:

[0035] (1) Disconnect the upper hinge point between the main boom 2 and the auxiliary boom 4, or between two adjacent segments of the auxiliary boom 4, so that part of the auxiliary boom 4 forms a delayed amplitude change section that is asynchronous with the main boom 2. When the main boom 2 changes its amplitude, the top of the delayed amplitude change section is not constrained and can slide along the ground, and the two gradually form an angle α;

[0036] (2) The main boom 2 is adjusted to a certain angle, and the front section 9 of the auxiliary boom 4 and the delayed amplitude adjustment section are connected. The front section 9 of the amplitude adjustment section is constrained to prevent the delayed amplitude adjustment section from rotating clockwise toward the main boom 2. Then, the arm sections of the main boom 2 are driven to extend, and the delayed amplitude adjustment section is pushed to straighten by the arm sections of the main boom 2.

[0037] The delayed luffing section is formed to reduce the load of the luffing cylinder in the initial stage of the boom, but after the boom is raised, the delayed luffing section needs to be stretched back and straightened. The main boom 2 is used as the driving force of the delayed luffing section. Compared with the winch driving force of the super-lifting mechanism 3, the pulling force of the extended luffing section is greatly improved. The angle α between the delayed luffing section and the main boom 1 should be an obtuse angle, that is, 90<α<180°.

[0038] The connection method between the front section of the delayed amplitude variation section and the main boom 2 is not limited. When the main boom 2 is lifted, the delayed amplitude variation section can be pulled from the upper side of the auxiliary arm 4 to prevent the extended amplitude variation section from bending toward the main boom 2. In order to avoid introducing other structures, the front section of the delayed amplitude variation section is connected to the super-lifting mechanism 3 located on the main boom 2, and the super-lifting mechanism 3 is a mechanism of the crane. The super-lifting mechanism can also be replaced by other structures, such as steel ropes. According to the working conditions, a certain length of steel rope is preset between the upper front section of the delayed amplitude variation section and the main boom 2. The length of the steel rope is greater than the distance between the two connection points. Therefore, when the main boom 2 is lifted and lifted, the top of the delayed amplitude variation section can slide along the ground and form a certain angle with the main boom. When the steel rope is straightened, a connection is formed between the main boom 2 and the delayed amplitude variation section.

[0039] Take the super lift mechanism 3 as an example. Figure 2, the super-lifting mechanism 3 is located on the main boom 2. The super-lifting mechanism 3 consists of a bracket, a front pull, a rear pull, and a winch. The super-lifting mechanism 3 is used to reduce the deformation of the main boom 2 when lifting a heavy load. The winch of the super-lifting mechanism 3 is connected to the front end 9 of the front pull 6 and the auxiliary boom 4. The rear pull is connected to the vehicle body 8 or the main boom 2 through a connecting member 7. The super-lifting mechanism 3 is used to connect the front section of the delayed luffing section and the main boom 2, and the angle between them can be controlled in real time, which is beneficial to adjustment. When the delayed luffing section needs to be straightened, the winch of the super-lifting mechanism 3 is self-locked and acts as a driven structure to prevent the delayed luffing section from rotating towards the main boom.

[0040] The delayed luffing section can be restored to a straight state before the main boom 2 is raised to the working angle, or it can be straightened when the main boom 2 reaches the working angle. When it is straightened before being raised to the working angle, the delayed luffing section needs to have passed the horizontal state to reduce the self-gravity moment of the delayed luffing section.

[0041] Taking the example of straightening the delayed luffing section when the main boom 2 reaches the working angle, when the luffing thrust arm of the main boom 2 is small in the horizontal state, a part of the auxiliary boom 4 is lifted to form a certain angle between the delayed luffing section and the main boom 2; before reaching the working angle, when the luffing thrust arm of the main boom 4 has a certain elevation angle and is large, the angle between the delayed luffing section and the main boom 2 is fixed, and the delayed luffing section luffs with the main boom 2. When the main boom 2 reaches the working angle, the boom section of the main boom 2 extends to push the delayed luffing section to straighten. The specific steps are as follows:

[0042] (1) Disconnect the upper hinge point between the auxiliary boom 4 and the main boom 2, so that the auxiliary boom 4 and the main boom 2 form two parts: the first section that always luffs synchronously with the main boom 2, and the second section with a delayed luffing characteristic relative to the first part;

[0043] (2) Start the luffing cylinder 1 to drive the main boom 2 to luff. Start the winch of the super-lifting mechanism 3 to release the towing rope, so that the top of the second section of the delayed luffing is supported on the ground and can slide along the ground, as Figures 10 to 12 , taking the arm of the luffing cylinder 1 in the horizontal state of the main boom 2 as a reference, when the arm of the luffing cylinder 1 is greater than the initial arm, for example, when the real-time arm is more than 1.1 times the initial arm, control the winch of the super-lifting mechanism 3 to stop and self-lock, so as to form a constraint between the second part and the main boom, and the main boom 2 drives the second section to luff synchronously;

[0044] (3) The main boom 2 continues to luff to the working angle, and any boom section of the main boom 2 extends. The second section rotates around the lower hinge point, as Figures 7 to 9 , and the hinge heads 401 and hinge seats 402 of the upper hinge points of the first part and the second part gradually approach, and finally align and pass through the shaft to complete the boom raising.

[0045] Example 2: On the basis of Example 1, the following deformations are also included in this example: As Figure 6, a buffer member 10 is provided between the auxiliary boom 4 and the main boom 2, or between two adjacent segments of the auxiliary boom 4. When the hinge point is disconnected, the buffer member 10 extends. Taking the buffer member 10 between the auxiliary boom 4 and the main boom 2 as an example, the bottom end 1001 of the buffer member 10 is connected to the main boom 2 by hinge, and the top end 1002 is connected to the auxiliary boom 4 through a bracket. The buffer member 10 can be a hydraulic cylinder, an oil cylinder, a spring mechanism or other structures that can provide certain support and have variable length. Manufacturing errors of the main boom 2 and the auxiliary boom 4 are inevitable. Therefore, as Figure 8 , Figure 9 shown, position switches 11 are respectively arranged on the disengaged hinge joint 401 and the hinge point seat 402 to form a hinge point alignment detection point. When the hinge joint 401 and the hinge point seat 402 are close to and detected, the hinge joint 401 and the hinge point seat 402 are basically aligned. At this time, the extension of the boom section slows down or stops. After the hinge point is aligned, the shaft-passing operation needs to be completed. Since the position of the shaft-passing point is relatively high, the shaft-passing is carried out in a remote operation mode, such as hydraulic power shaft-passing, electric power shaft-passing, etc. To ensure the safety of shaft-passing, a position switch 12 is also arranged on the hinge point seat 402 to form a shaft-passing detection point to determine that the pin shaft 403 is completely inserted into the shaft hole, realizing reliable connection between the hinge joint 401 and the hinge point seat 402.

[0046] Embodiment 3: On the basis of Embodiment 2, the following deformation is further provided in this embodiment: As Figure 2 shown, a mast 5 is provided on the upper part of the auxiliary boom 4 for supporting the cable 6. In step (1), the disconnected hinge point is located between the main boom 2 and the mast 5, and the mast 5 rotates with the disconnected part of the auxiliary boom 4 to increase the moment formed by the cable. The position of the mast 5 is determined according to the specific working conditions and the length of the auxiliary boom 4.

Claims

1. A method for raising a boom, wherein the boom comprises a telescopic main boom and a secondary boom formed by splicing a plurality of segments, wherein the main boom and the secondary boom and two adjacent segments are connected by a plurality of hinge points, wherein: The boom raising method is as follows: disconnecting the upper hinge point between the main boom and the auxiliary boom, or between two adjacent segments of the auxiliary boom, so that some segments of the auxiliary boom form a delayed amplitude variation section that varies asynchronously with the main boom, the main boom varies to a certain angle, connecting the front section of the delayed amplitude variation section and the main boom, driving the arm section of the main boom to extend, and pushing the delayed amplitude variation section that forms a certain angle with the main boom to straighten.

2. The boom raising method according to claim 1, characterized in that: The range of the angle α formed between the delayed amplitude variation section and the main arm is 90<α<180°.

3. The arm raising method according to claim 1, characterized in that: The front section of the delayed amplitude variation section is connected to the main boom, and the delayed amplitude variation section can vary the amplitude synchronously with the main boom.

4. The arm raising method according to claim 3, characterized in that: The front section of the delayed amplitude variation section is connected to the main arm. The delayed amplitude variation section varies synchronously with the main arm and continues to vary to a working angle, driving the arm sections of the main arm to extend and pushing the delayed amplitude variation section to straighten.

5. The arm raising method according to claim 3, characterized in that: The main arm is provided with a super-lifting mechanism, the front section of the delayed amplitude variation section is connected to the winch of the super-lifting mechanism, and when the front section of the delayed amplitude variation section and the main arm are connected, the winch of the super-lifting mechanism is self-locking.

6. The arm raising method according to claim 5, characterized in that: The winch and auxiliary arm of the super lifting mechanism are connected by a cable. A mast for supporting the cable is provided on the auxiliary arm, and the disconnected hinge point is located between the main arm and the mast.

7. The arm raising method according to claim 1, characterized in that: After the delayed amplitude variation section is straightened, the disconnected hinge point is restored.

8. A crane using the boom raising method according to any one of claims 1 to 7.

9. The crane according to claim 8, characterized in that A buffer is provided between the main arm and the auxiliary arm, or between two adjacent sections of the auxiliary arm. When the hinge point is disconnected, the buffer extends.

10. The crane according to claim 8, characterized in that The hinge point is provided with a switch for detecting whether the hinge point is aligned and whether the shaft is in place.

Images