JPS61206793A - Method of erecting gantry in crane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for raising a gantry in a crane, which is used to raise a gantry that has been laid down during transportation or the like during use.

(Prior art) In crawler type cranes, etc., the boom can generally be divided into upper and lower parts, and the lower end of the lower boom is attached to the front of the crane body, and the gantry installed at the rear of the crane body can be raised and lowered. When the crane is transported, the boom is divided and the gantry is lowered, thereby reducing the amount of protrusion of these parts and lowering the overall height of the vehicle body.

Conventionally, when the gantry of this type of crane is erected, it is usually composed of a compression member 31 that is rotatable around the lower end and a tension member 32 that is extendable or foldable, as shown in FIG. When the gantry 3 that can be raised is in the laid down state, the crane body 1
After assembling the boom 2 by connecting the upper boom 22 and the intermediate boom to the lower boom 21 attached to the The method used was to raise the J stiff gantry 3.

However, with a large crane with a relatively long boom 2,
When transported by a trailer or the like, the upper boom 22 and the like removed from the lower boom 21 may be transported separately. In such a case, in order to efficiently carry out crane assembly work even if the arrival of the upper boom 22, etc. to the site is delayed,
There is a demand for easily erecting the gantry 3 with the upper boom 22 etc. removed, and the above method cannot satisfy this demand. Therefore, as a method to satisfy such requirements, with the upper boom 22 etc. removed, the tip of the boom hoisting line 4 is attached to the upper end of the lower boom 21 as shown by the two-dot chain line in Fig. 7. It is conceivable that the boom hoisting line 4 be hoisted up, but in the past there was a safety problem in this case, so this method could not be adopted.

That is, when the boom hoisting line 4 between the upper end of the gantry 3 and the upper end of the boom 2 (or the upper end of the lower boom 21 when the upper boom 22 etc. are removed) is hoisted by the winch 40. , the weight of the boom 2 (or lower boom 21) is Wl, the equivalent load on the upper end of the gantry 3 is W2, and the horizontal distance from the center of movement of the bottom of the boom 2 to the center of gravity of the boom 2 (or the lower boom 21). a
l, the distance from the rotation center to the boom undulation line 4 is Q2, and the quality of the compression member 31 is f! 3. If the distance from the center of rotation of the lower end of the member 31 to the boom hoisting line 4 is a4, the tension on the boom hoisting line 4 required to raise the boom 2 (or the lower boom 21) is [Wl ・Q1 /Q2], the tension of the boom hoisting line 4 required to raise the gantry 3 is [W2・Q2/Q+1, so Wl ・01/Q2 > W2 ・j23/f! If the condition < is satisfied, the gantry 3 is raised. However, when the upper boom 22 etc. are removed, the lower boom 2
Since the weight of 1 [IWl and the distance 11ρ1 from the lower boom 21 to the center of gravity are relatively small, the above conditions are not satisfied when the lower boom 21 is lying down, so when the boom hoisting line 4 is hoisted, the lower boom first 21 got up,
If the boom hoisting line 4 continues to be hoisted up, the distance ρ4
When the lower boom 21 rises to the point where the above conditions are satisfied, the gantry 3 is raised due to the overlapping of the lower boom 21.
1 will tilt in the direction of collapse, which is extremely dangerous.

For this reason, in the past, it was unavoidable to assemble the boom 2 and
By increasing W1t3 and distance fil and then hoisting the boom hoisting line 4, the boom hoisting line 4 was raised while the boom 2 was laid down, but this caused problems in work efficiency as mentioned in @. There is.

(Purpose of the Invention) In view of the above circumstances, the present invention has been developed in such a manner that the upper boom etc. are removed from the lower boom attached to the crane body! 62 (It-) describes a method for raising guns 1 to 1 in a crane that can safely raise a gantry on an IIN.

(Structure of the Invention) The present invention provides for attaching the lower end of the lower boom, which is composed of a plurality of upper and lower parts that can be divided and connected, to the front part of the crane main body so as to be able to raise and lower the lower end of the boom. A gantry that can be raised and lowered is provided by connecting a rotatable compression member and a telescopic or foldable tension member at the lower end, and the boom is supported by a boom raising and lowering line led out from the winch through the upper end of the gantry. In a crane constructed as shown in FIG. Then, the lower boom is raised to a predetermined angle by winding the boom hoisting line with a winch, and then the lower boom is raised to the predetermined angle 1.
m, the boom hoisting line is roughly wound up to increase the tension of the boom hoisting line between the lower boom and the gantry to erect the gantry, and after the gantry is erected, the gantry is fixed with a locking means. It is something.

In other words, the gantry can be easily raised with only the lower boom attached to the crane body before the boom is assembled, and the lower boom does not tilt in the direction of collapse when raised. .

(Example) FIG. 1 shows an example of a crane to which the method of the present invention is applied. In this figure, reference numeral 1 denotes a crane main body, which is composed of a traveling body 11 and a revolving body 12 rotatably attached to the traveling body 11. A boom 2 is installed at the front of the revolving body 12.
A gantry 3 is installed at the rear, and a counterweight 13 is installed roughly at the rear end.

The boom 2 connects a pre-divided lower boom 21 and an upper boom 22, or connects the lower boom 21 and the upper boom 22.
The lower boom 21 is assembled by further connecting an intermediate boom (not shown) between the upper boom 22 and the upper boom 22, and the lower end of the lower boom 21 is attached to the front part of the revolving body 12 so as to be able to raise and lower. Further, the gantry 3 can be raised and lowered, and is fixed in an upright position when in use.

The boom 2 is supported by this gantry 3 via a boom hoisting line 4.

The boom hoisting line 4 is composed of a boom hoisting row 141 led out from a winch 40 installed on the revolving body 12 through the upper end of the gantry 3, and a spreader 42 attached to the upper end of the gantry 3 and the tip of the line. By passing the boom hoisting row 141 to the side spreader 43, the length can be changed according to the operation of the winch 40. When the crane is in use, the tip end 44 of the boom hoisting line 4 is connected to the upper end of the upper boom 22 via the guy rope 45, so that the boom 2 is supported in a forwardly tilted state so as to be hoistable. When the boom 2 is divided, the tip portion 44 of the boom undulation line 4 can be replaced with the attachment portion 23 of the lower boom 21. A rope 51 led out from a winch 50 is hung on the upper end of the boom 2, and the rope 51 constitutes a hoisting line 5 for lifting and lowering the suspended load.

A backstop 6 is connected between a predetermined location of the revolving body 12 and the tip of the lower boom 21. The backstop 6 extends and contracts as the boom 2 rotates by means of a pair of vibros 1.62 which are slidably fitted into each other and whose respective ends are pivotally connected to the revolving body 12 and the lower boom 21. In addition, when the boom 2 is erected to a state where it is slightly tilted forward from the upright position, the length becomes the minimum, thereby regulating the maximum erecting angle of the boom 2 and preventing the boom 2 from falling backward. I'm trying to prevent it. In the embodiment, as a means for restraining the lower boom 21 at a predetermined angle smaller than the original maximum raising angle when the gantry 3 is raised, the above-mentioned predetermined angle is set as shown in FIG. Sometimes both vibro 1 of backstop 6
．． 62 can be fixed with a pin 63.

FIG. 3 shows the specific structure of the gantry 3.

This gantry 3 includes a compression member 31 and a tension member 32 which are rotatably connected to each other at the upper end.
The tension member 32 has upper and lower parts 3.
2a, 32b, 32C are F! The tension member 3 can be expanded and contracted by fitting together so that it can move.
The lower end of the compression member 31 is rotatably attached to an attachment part 33 at the rear end of the revolving body 12, and the lower end of the compression member 31 is rotatably attached to an attachment part 34 installed at a predetermined location on the revolving body 12. The mounting number is numbered so that it can be moved. In this way, the gantry 3 is in an upright state where the tension member 32 is extended and the compression member 31 protrudes diagonally backward from a predetermined location of the revolving body 12, as shown by the solid line, and in an upright state where the tension member 32 is shortened and the compression member 31 falls backward. The lock bin 35 as a locking means can be raised and lowered, and in the upright state and the laid down state, the lock bin 35 as a locking means is
The upper and lower parts 32a, 32b of the tension member 32,
Gantry 3 can be fixed by fixing 32c.

It's becoming a sea urchin. Guide sheaves 36 and 37 for the boom hoisting lobes 41 are attached to the upper and lower ends of the combo member 31, respectively. Also,
When the boom hoisting line 4 is in the lodging state, the boom hoisting line 4 is connected to the attachment part 34
A lobe receiver 38 is provided near the lower end of the tension member 32 to protrude upward to prevent contact or interference with the tension member 32 and the like. In this example, the tension member 32 is expandable and retractable, but it may also have a foldable structure.

Cranes with the structure described above use boom 2 during transportation, etc.
is divided, and the gantry 3 is lowered. The method of the present invention is used to raise the gantry 3 from this state, and this method will be explained below with reference to FIG. 4 and FIG. 6.

First, as shown in FIG. 4, only the lower boom 27 at the back of the boom 2 is attached to the crane body 1.
The tip of the boom hoisting line 4 is attached to the upper end of the lower boom 21 with the gantry 3 lying forward and backward, and from this state the boom hoisting line 4 is hoisted up by the winch 40. As a result, a tension force is applied to the boom hoisting line 4 between the lower boom 21 and the gantry 3, which tends to cause the lower boom 21 and the gantry 3 to each other, but the tension member is attached to the bin in the contracted position. Since the lower boom 21 is locked, the gantry is not raised and the lower boom 21 is raised first.

In this way, as shown in FIG. 5, the lower boom 21 is raised to a predetermined angle θ while the gantry 3 is laid down, and the hoisting operation is temporarily stopped here. This predetermined angle θ is the maximum angle at which the lower boom tilts in the lowering direction after the gantry is erected and the lower boom is tilted in the lowering direction by overcoming the drag force due to gravity etc. and unwinding the boom hoisting rope. Good. By fixing the backstop 6 with the pin 63 at this predetermined angle θ, the lower boom 21 is restrained from rising any further.

Next, the locking pin of the tension member is removed and the winch 40 is operated again to further hoist the boom hoisting line 4, thereby raising the gantry 3 as shown in FIG. In other words, since the boom hoisting line 4 is hoisted with the lower boom 21 raised and restrained, the front iM 04
Due to the large size, the gantry 3 can be raised with a small force, and the lower boom 21 does not fall forward.

After erecting the gantry 3 in this way, lock bin 35
to fix the gantry 3 in the upright position. After that, Bin 63
The lower boom 21 may be released from being restrained by the backstop 6 by removing the lower boom 21 from the backstop 6.

After the gantry 3 is erected by the above method, the lower boom 21 can be freely raised and lowered, and the upper boom 22 and the like are connected to the lower boom 21, and the boom hoisting line 4 is attached.
) The crane can be easily assembled into the state shown in FIG. 1.

(Effects of the Invention) As described above, the present invention allows the gantry to be erected with the upper boom etc. removed from the lower boom,
By attaching the tip of the boom hoisting line to the lower boom and hoisting the boom hoisting line, the lower boom is first raised to a predetermined angle, and after the boom hoisting line is restrained at this angle, the boom hoisting line is further hoisted. Since I am trying to raise the gantry,
Even if there is a delay in the arrival of the upper boom, etc. to the site, the gantry can be easily erected, and the lower boom does not rotate in the direction of collapse when the gantry is erected, allowing work to be carried out safely. .

[Brief explanation of the drawing]

Fig. 1 is a side view showing an example of a crane to which the method of the present invention is applied, Fig. 2 is an enlarged sectional view showing an example of means for restraining the boom at a predetermined angle, and Fig. 3 does not show the specific structure of the gantry. 4 to 6 are detailed explanatory views of the present invention, and FIG. 7 is a schematic side view for explaining the conventional C method and the problems of the conventional method. 1... Crane body, 2... Boom, 3... Gantry, 31... Compression member, 32...
Tension member, 35...Lock bin, 4...Boom hoisting line, 40...Winch, 6...Backstop, 63...Bin. Patent applicant: Kobe Steel, Ltd. Agent
Patent Attorney Etsushi Kotani Patent Attorney
Long 1) Masamukai Patent Attorney Tomio Itaya Figure 3

Claims (1)

[Claims] 1. Lower part of the boom consisting of multiple upper and lower parts that can be divided and connected The lower end of the boom is attached to the front of the crane body so that it can be raised and lowered, and a compression member is attached to the rear of the crane body that can rotate around the lower end. A crane is provided with a gantry that can be raised and lowered by connecting a telescopic or foldable tension member at its upper end, and the boom is supported by a boom raising and lowering line led from the winch through the upper end of the gantry. Remove the other parts of the boom from the lower boom, lower the lower boom to the front of the crane body, and with the gantry laid down, connect the tip of the boom hoisting line to the upper end of the lower boom, and then The lower boom is raised to a predetermined angle by winding up the hoisting line with a winch, and then, after restraining the lower boom at the predetermined angle, the lower boom and gantry are raised by further winding the boom hoisting line. A method for raising a gantry in a crane, comprising increasing the tension of a boom hoisting line between the cranes to raise the gantry, and after raising the gantry, fixing the gantry with a locking means.