JPH0213598A - Level luffing crane - Google Patents

Abstract

PURPOSE:To reduce the inclination of a container suspended at 4 points in the longitudinal direction when it is lifted/lowered by setting a sheave provided for a mast in a position with little undulation irrespective of change in slewing radius in the position of a sheave at the end of a top boom. CONSTITUTION:A link 26 for suspending No.2 sheave 25 from the end of a top boom 8 in such a state where the sheave can freely be shifted in its vertical direction is provided, and a lip boom in the vicinity of a connecting point with a main boom 5 is provided with two No.3 sheaves 29. And a drum 27 is provided for the lower area of a mast, and two ropes 28 drawn from the drum 27 are hung over two No.4 sheaves 69 provided for the mast and No.3 sheave 29 in order, so as to be connected to the link 26. A spreader (hoisting accessory) 50 is mounted with four ropes 25 suspended from No.1 and No.2 sheaves 19, 25 at the end of the top boom 8. Then the spreader 50 can be kept approximately at a level and its inclination can be reduced irrespective of the undulation of a main boom 5 owing to the functions of No.3 and No.4 sheaves 26, 29.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a retraction crane for handling container cargo.

[Conventional technology]

A retractable crane consists of a mast installed on a base, a main boom rotatably attached to the bottom of the mast, a top boom rotatably attached to the tip of this main boom and supporting the suspended load, and this top boom. A tension boom that pulls the other end of the boom toward the mat, a lifting device that is suspended by a hoisting rope wound around a sheave installed at the tip of the top boom, a drum that hoists the hoisting rope, and a main boom. It is equipped with a retraction device that performs extrusion and retraction. Such a retractable crane is, for example, disclosed in Japanese Unexamined Patent Publication No. 1983
-67955, JP-A No. 54-122551, and No. 55-35765.

[Problem to be solved by the invention]

Such retractable cranes are generally used to handle cargo by hanging packets or hooks.

Conventionally, when hoisting a container, a first link is provided below the top boom in parallel, and this first link and h-/
A second link connects the top boom to the top of the top boom, a second sheave is installed at the connection point between the first link and the second link, and two ropes are connected directly from the sheave at the top of the top boom. The other two ropes are suspended from the tip sheave via the second sheave to perform four-point suspension.

On the other hand, when hanging a packet or a hook, four ropes are hung directly from the sheave at the tip, excluding the first link, second link, and second sheave.

A crane whose cargo moves almost horizontally as the main boom is retracted is called a horizontal retraction crane.

The fact that the load moves horizontally means that no energy is required to pull in or push out the load at a constant speed.

However, in order to obtain a perfect horizontal trajectory, the mechanism becomes complicated and is not practical.

Conventionally, an approximately horizontal mechanism has been adopted, but this has not caused any particular problems in packet cargo handling and hook cargo handling.

When four-point lifting is performed during container cargo handling, this trajectory becomes a MW problem because the container is long.

Since the trajectory was not completely horizontal, the position of the point of emphasis of the four-point suspension changed during the retraction operation, causing the container to tilt in the longitudinal direction, which was very dangerous when it took off and landed on the ground.

An object of the present invention is to achieve a perfectly horizontal trajectory to the extent that it does not pose a problem in practice when four-point suspension is performed.

[Failure to solve the problem]

The above purpose is to install a sheave at any position on the mast.
- This is achieved by minimizing changes in the key position even if the turning radius changes due to pulling in or pushing out the main boom. [Function] The position of the sheave installed on the mast is determined so that the position of the sheave at the tip of the top boom will not change much even if the radius changes four times due to the retraction and extrusion of the main boom. Even if the spreader turns and the container takes off and lands in a state where the longitudinal direction of the container coincides with the boom direction, there is no particular problem because the inclination is small.

〔Example〕

Hereinafter, details of the present invention will be explained with reference to an embodiment shown in the drawings.

'M1 In the figure, 1 is the next body placed on the traveling body 2, which rotates on a horizontal plane. The following items are mounted on the revolving body 1. 5 is a main boom, which is rotated by a retraction device 6. The retraction device 6 is attached to the mast 7. A top boom 8 is rotatably attached to the tip of the main boom 5. The rear end of the boom 8 and the mast 7 are connected by a tension boom 9. 1o is a counterweight.

As shown in FIGS. 1 to 6, four ropes 15 are attached to the end of the side of the mast 7 and the rear end and tip of the top boom 8.
Sheaves 16, 17 and 18 and 19 are provided through which a, 15b, 15c and 15d pass, respectively. Sheaves 16, 17 and 18, 19 each consist of four sheaves. Ropes 15a and 15d passing through outer sheaves 19a and 19d are wound around a drum 21. Inner sheave 19b.

The ropes 15b and 15c passing through 19c are wound around the drum η. Reference numeral 5 denotes a sheave suspended from the tip of the top boom 8 by a link, and is operated by a rope path of a drum n installed on the revolving structure 2. The rope path is stretched along the main boom 5 from the sheave 69 installed on the mast 7,
It is connected to the link through the sheave at the tip of the main boom 5. The linkage is coaxially connected to the sheave 5. Sheaves 5° and 69 each consist of two pieces, and are installed vertically below the ropes 15a and 1sd. Drum 21.
22.27 can each be operated independently. drum 21
and Party B can operate in synchronization.

The configuration around the sheave 5 at the tip of the top boom 8 will be explained with reference to FIGS. 7 and 11. Although the following description will be made regarding the sheave 15 a side, the sheave 19 d side also has the same configuration in principle. A link is rotatably installed coaxially with the sheave 19 at the tip of the top boom 8. A sheave 6 and a link section are rotatably installed at the tip of the link. The sheave 5 and the link recess are coaxial. A rope string is connected to the tip of the link chrysanthemum.

As shown in FIG. 11(A), the links are attached to the shaft 31 on both sides of the sheave 15a. The cross section of the link portion is H-shaped.

As shown in FIG. 11(D), the sheave 6 is located at the center of the link, and the links are located on both sides of the link. A plate is inserted into the recess of the shaft and fixed to the link with a bolt 37 to prevent rotation and movement of the shaft I. The link consists of two plates, and the left and right plates are fixed together with bolts 41 via a spacer.

A roller capable of supporting the rope 15a is provided on the upper surface side of the link portion. Roller a is on rope 15 during normal operation.
Although they do not touch each other, they are installed close to each other. As shown in FIGS. 11(0) and 11(D), the length L of the shaft material supporting the roller structure is sufficiently longer than the width l of the link (9). Also, the rollers can be placed inside the left and right plates of the link part.

Rope 15B, 15b, 15c,
At the connecting end of 15 d to the important word, a connecting metal fitting made of, for example, kotsuta and kerato is provided. Reference numeral 15f in FIGS. 2 and 3 indicates a portion connected to the spreader and the bracket of the hanger of the packet 51 via a pin. For the sheave 52 for opening and closing of the packet 51 shown in FIG. 3 and the sheave 52 of the hook-up box shown in FIG. 4, a rope 55 is used to connect the connecting fittings of each rope audience. 15g indicates this connection. The connecting portion 15g is connected by passing a pin through the metal fittings of both ropes.

Cargo handling work in this configuration will be explained.

First, ropes 15a and 15d are suspended from sheaves 19a and 19d to sheaves 25a and 25b. in this case,
・7 As shown in Fig. 11 CB), pass through the link part through the ogo and attach the roller. Connect the rope part to the link (9). Ropes 15b and 15C are suspended from sheaves 19b and 19C.

When suspending the container spreader 50, the rope portion is also wound up on the drum n, and the ropes 15b, 15
Wind up c with drum n and pull it until the spreader is horizontal. Drum n is fixed in that state. Since the sheave 5 is pulled by the rope section, the ropes 15a, 15
d is suspended substantially parallel to the ropes 15b and 15c, and the distance between the black dots for four-point suspension can be maintained.

And drum 21. By operating Z2 in synchronization, the height of the spreader can be adjusted.

By operating the retraction device 6, the spreader is moved approximately horizontally. In this case, if the sheave 4 is provided at the connection point between the top boom 8 and the main boom 5, the spreader will not tilt.

However, it is difficult to install a sheave catcher at the center of rotation of the top boom 8, so as shown in Fig. ), the length of the rope is constant and the spreader slope is sloped.

The sheave 69 is installed at a position where it is structurally easy to install, and the sheave 69 is installed at a position where the amount of inclination of the spreader does not cause any actual damage.

Next, the case of hanging the packet 51 and the hook will be explained. In this case, as shown in FIGS. 3 and 4, the rope portion is sufficiently loosened using a drum γ.

Then, the rope groups for the sheaves 52 and 54 are combined and connected to a hanging tool. Operate the drums 21 and 22 appropriately and tighten the rope 15 so that the packet 51 and the hook are horizontal.
Adjust the length. When the hanging tool is lifted, the ropes 15a, 1
Due to the tension of 5d, the sheave δ moves to the outside of the sheave 19 as shown in FIGS. 9 and 10, and the ropes 15a, 15
d hangs vertically.

When the top boom 8 is set to the minimum radius, as shown in Fig. 10, the sheave 5 is located outside the center line P connecting the sheaves 18 and 19, so the rope section is attached directly to the shaft of the sheave δ. And the rope part is sheave 19a, 19d
or in contact with the sheave 19a.

19b and the top boom 8, damaging the rope row.

For this reason, a link is provided so that the rope row can be connected to the sheave 1.
It is arranged to be located inside of 9.

However, the link (9) is pulled by the rope row and tends to become parallel to the link %. This is because the weight of the link is lighter than that of the rope, and the distance between drum n and sheave 9 is longer than the distance between sheave 4 and sheave 5.

Therefore, the length L of the shaft member is made longer than the width l of the link (material) to prevent the link nod from hitting the shaft member and causing the link portion to become taut. This allows the rope row to move to sheave 19.
It is always located inside.

If the top boom 8 is extended from the inside to the outside (or vice versa) and stopped, the ropes 15a and 15b may come off the sheave 5, and the rollers 4 prevent this. Since the shaft material of the 20 rollers is also used as a stopper for positioning the link, the members can be made with less noise and can be made lightweight and inexpensive.

As described above, the sheave 6 for hanging at four points is attached to the loaf 28.
Therefore, when changing the hanging tool, the ink dots can be changed extremely easily and safely.

In addition, a link recess is provided between the sheave 3 and the rope part, and a stopper (shaft 44) for adjusting the angle of this link part is provided in the link part, so that when a packet or hook is hung, the rope row is This can prevent contact with the sheave 19. Note that the link does not need to be coaxial with the sheave 5. It is also conceivable to provide the stopper with a roller 70 protruding from the rope Z side of the boom 8 as shown in FIG. 8 to prevent the rope portion from contacting the sheave 19.

Of course, a stopper is necessary to prevent the link chrysanthemum from being parallel to the link.

Further, since the stopper is also used as the shaft of the roller for preventing slippage, the cost can be reduced.

, 11.

In the case of two-point hanging using a hook 53 or the like, the sheave 5 can be pulled by a row of ropes, and the ropes from the sheaves 19, 25 to the hanging tool (hook 53) can be arranged diagonally.

Now, since the sheave 69 is installed between the sheave 4 and each drum, the horizontality of the spreader can be kept almost constant no matter what the up-and-down angle of the main boom 5 is. Although the drum n may be provided at the sheave 69, it is practically impossible to provide a large drum n at the sheave 69. Since the sheave 69 is smaller, it can be easily installed in an optimal position.

As is well known, the length of each link of a double-link crane and the trajectory of the lifting equipment are determined by trial and error. The calculation of the optimum position of the sheave 69 is also similar to this.

Other embodiments shown in FIGS. 2, 3, and 4 will be described. The sheaves 69, 69 can be moved in the axial direction by a drive device (for example, a cylinder device i70.70). When placing the spreader 50 on the floor, if the spreader 12 is tilted, the driver must
By driving 0.70 and changing the position of sheave 6 (1, 69), the amount of inclination of the spreader is corrected.

The two drives 70.70 operate simultaneously by the same amount;
The distance between the two sheaves 69, 69 is shortened or separated.

Note that the sheaves 69, 69 may be moved in the radial direction.

〔Effect of the invention〕

According to the present invention, when performing four-point suspension, it is possible to approximate a perfectly horizontal trajectory to the extent that it does not cause any practical problems,
There is little inclination of the container in the longitudinal direction, allowing safe work even when cutting off the ground and landing on the ground.

[Brief explanation of the drawing]

Figure 1 is an overall front view of the retraction crane, Figure 2 is a perspective view showing the arrangement of ropes when hanging a spreader, Figure 3 is a perspective view showing the arrangement of ropes when hanging a packet, and Figure 4 is a perspective view showing the arrangement of ropes when hanging a packet.
The figure is a perspective view showing the arrangement of the rope when hanging a hook, Figure 5 is a front view of the area around the totsubu boom, Figure 6 is a diagram showing the arrangement of the top boom sheave, and Figure 7 is a diagram showing the arrangement when the spreader is hung. Figure 8 is a front view of the top boom tip with the top boom at its maximum radius, Figure 8 is a front view of the top boom tip with the spreader hanging and the top boom is at its minimum radius, and Figure 9 is a front view of the top boom tip with the hook set. Figure 10 is a front view of the tip of the top boom when the hook is suspended and the top boom is set to the maximum radius; Figure 11 is a front view of the tip of the top boom when the hook is suspended and the top boom is set to the minimum radius. The figure is a sectional view taken along line A-B-0 in FIG. 7. 2...Swivel body, 5...Main boom, 6
...Retraction device, 7...Mast, 8...
...Top boom, 9...Tension boom, 15, 15 a, 15 b, 15 c
r15 d----・O-p, 16. 17.18
．． 19.19a, 19b.

Claims (1)

[Claims] 1. A mast, a main boom rotatably attached to the bottom of the mast, a top boom rotatably attached to the tip of the main boom, and a rotatable structure between the rear end of the top boom and the top of the mast. a tension boom attached to the top boom, two first sheaves placed on the left and right of the tip of the top boom, two second sheaves placed on the left and right of the rear end of the first sheave, and two second sheaves placed on the left and right of the rear end of the top boom; In a retractable crane consisting of four ropes for lifting equipment suspended from a second sheave,
a link in which the second sheave is vertically rotatably suspended from the tip of the top boom; two third sheaves installed on the lip boom near a connection point with the main boom; After the two fourth sheaves installed on the mast, the drum installed at the bottom of the mast, and the two ropes fed out from the drum are sequentially applied to the fourth sheave and the third sheave, A retractable crane characterized by being connected to a link.