JPH066380U - Counterweight attachment / detachment device for cranes - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To prevent a large bending moment from acting on the boom when installing the counterweight. [Structure] A spreader bracket 23 is provided at the same position as or in the vicinity of the back stopper bracket 21 on the back surface of the boom 7, and the upper spreader 14 is attached to the spreader bracket 23 when the counterweight 3 is attached or detached. At times, the distance between the point of action of the boom erecting force on the boom 7 and the point of boom support by the back stopper 17 is made small (minimum 0).
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Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a crane counterweight attaching / detaching device for attaching / detaching a counterweight of an upper swing body by itself without using a separate crane or the like.

[0002]

[Prior art]

 Conventionally, as a self-attaching / detaching method for a counterweight, the one disclosed in Japanese Utility Model Laid-Open No. 59-190791 has been known.

Explaining this with reference to FIG. 6, a gantry 2 (consisting of a front member 2a having a constant length and a rear member 2b capable of expanding and contracting) installed on the upper swing body 1 serves as a lifting mast for the counterweight 3. The method used, that is, the gantry peak pin 4 at the top of the gantry and the counterweight 3 are connected, and the gantry 2 is raised and lowered in this state, so that the counterweight 3 is attached to the upper revolving structure 1 as a revolving structure. A method of moving between a position on the weight table 5 at the rear end and a position on the ground behind the revolving structure is known.

Since the counterweight 3 and the weight base 5 interfere with each other only by the undulating motion of the gantry 2, the hydraulic cylinder 6 is used as a connecting member for connecting the counterweight 3 and the gantry peak pin 4. The counter weight 3 is vertically moved by the cylinder 6 at the initial stage and the final stage of the weight attachment / detachment.

In this method, the hoisting operation of the gantry 2 is performed by winding and unwinding the boom hoisting rope 8 while the boom 7 is fixed so that it cannot be hoisted. At this time, the boom 7 is fixed by suspending the anchor rope 11 between the boom tip and both crawler frames 10 of the lower traveling body 9.

In the figure, reference numeral 12 is a boom hoisting winch, and a boom hoisting rope 8 pulled out from this winch 12 passes through a gantry sheave 13 provided on a gantry peak pin 4 and both upper and lower spreaders 14, 15 It is hung around in between.

Reference numeral 16 is a guy cable suspended between the upper spreader 13 and the boom tip portion, and 17 is a pair of right and left (only one side is shown in the figure) for restricting the maximum standing angle of the boom 7 and preventing it from rolling. With the back stopper (shown), when the counterweight is attached or detached, the back stopper 17 is fixed to a constant length by a pin 18 to prevent the boom 7 from tilting and turning.

However, according to this method, the anchor rope 11 is required as a dedicated component for attaching / detaching the weight, and the attachment / detachment work of the rope 11 is troublesome.

Therefore, as an alternative method, the anchor rope 11 is omitted, and as shown in FIG. 7, a state in which the hoisting motion of the boom 7 is blocked by a back stopper 17 (which is fixed by a pin 18 so that it cannot be expanded and contracted). A method of winding and unwinding the boom hoisting rope 8 was proposed.

[0010]

[Problems to be solved by the device]

 However, according to this method, when the counterweight is attached / detached, a force in the boom rising direction is applied to the boom tip end, while the boom 7 is prevented from standing upright by the backstop 17, so that the boom tip end is prevented. The distance L between the guy cable attachment point of the section, that is, the force application point A and the boom support point, that is, the back stopper attachment point B of the boom middle section becomes longer.

As a result, since a large bending moment acts on the boom 7, the boom strength must be set higher than the strength required for crane work so as to withstand the bending moment, and as a result, the boom weight is increased. However, there were shortcomings such as increase in cost and cost.

Therefore, the present invention provides a counterweight attaching / detaching device for a crane in which a large bending moment does not act on the boom when attaching / detaching the counterweight.

[0013]

[Means for Solving the Problems]

 According to the invention of claim 1, the upper swing body is mounted on the lower traveling body, and the upper swing body has a detachable counterweight at the rear end, a boom at the front end, and a space between the boom and the counterweight. Each gantry that can be undulated is provided with a back stopper between the rear part of the boom and the upper revolving structure that regulates the maximum boom upright angle. A boom hoisting rope that hoists the boom is hung between both upper and lower spreaders, and the upper spreader is attached to the boom tip via the guy cable, and the lower spreader is set to the above. The gantry has a connecting means which is respectively fixed to the top of the gantry and which connects the counterweight and the top of the gantry when the counterweight is attached and detached. In the lane, at the middle position in the boom length direction on the back side of the boom, at the same position as or near the boom side mounting part of the back stopper, there is provided a spreader mounting part to which the upper spreader is mounted when the counterweight is attached or detached. And a means for removably fixing the upper spreader to the spreader mounting portion.

According to a second aspect of the invention, in the structure of the first aspect, a bracket serving as a boom-side mounting portion and a spreader mounting portion of the backstop is provided on the rear surface of the boom, and the upper spreader is fixed to the bracket. The means comprises a link member, a pin for attaching one end of the link member to the bracket, and a pin for attaching the other end of the link member to the upper spreader.

[0015]

[Action]

 According to the above configuration, when the counterweight is attached or detached, the distance between the action point of the boom raising force of the boom and the boom support point of the back stopper can be made small (minimum 0), so that a large bending moment does not act on the boom. Therefore, the boom strength can be kept lower than in the conventional case.

Further, according to the structure of claim 2, in addition to the above basic operation, the bracket serving as the boom side mounting portion of the back stopper can also be used as the spreader mounting portion, so that the structure is simple and the boom weight is reduced. can do.

[0017]

【Example】

 An embodiment of the present invention will be described with reference to FIGS.

In each of the following embodiments, the same parts as those in the prior art shown in FIGS. 6 and 7 are designated by the same reference numerals, and the duplicate description thereof will be omitted.

First Embodiment (see FIGS. 1 to 3) A bracket mounting plate 20 (shown in FIG. 3) is provided over the entire width of the boom in the longitudinal middle portion on the rear surface of the boom, and this bracket mounting plate 20 is also provided. , A pair of left and right back stopper brackets 21 and 21 serving as backstop mounting portions are provided, and the boom side ends 17a and 17a of the back stopper 17 are attached to the brackets 21 and 21 by pins 22 and 22. .

A pair of left and right spreader brackets 23, 23 as spreader mounting portions are provided outside the brackets 21, 21 at the same position in the boom length direction as the back stopper mounting point on the rear surface of the boom. There is.

On the other hand, the upper spreader 14 is provided with a pair of left and right mounting seats 24, 24 at intervals corresponding to the brackets 23, 23. Denoted at 25 are guide sheaves for the boom hoisting rope 8 provided on the spreader 14.

The mounting seats 24, 24 are pin-connected to one end of the guy cable 16 shown in FIGS. 6 and 7 during crane work, and are attached to the spreader brackets 23, 23 as shown in the drawing when the counterweight is attached and detached. It is mounted coaxially with the stopper mounting pins 22, 22 by means of pins 26, 26.

In this way, the upper spreader 14 is connected to the middle portion of the boom 7 when the counterweight is attached or detached.

When mounting the counterweight 3, the gantry 2 is laid down as shown by the solid line in FIG. 1, and the back stopper 17 is fixed by pins 18 so that it cannot expand and contract to prevent the boom 7 from rising and falling. Wind the boom up and down rope 8 in this state.

In this way, while the rope winding force is applied to the boom 7 as an upright force, the upright rotation of the boom 7 is blocked by the back stopper 17, which causes the gantry to move as shown by the phantom line in FIG. 2 rises and the counterweight 3 is lifted.

In this case, the attachment point of the upper spreader 14 on the boom 7, that is, the point of action of the force that tries to raise the boom 7 and the support point that supports the boom 7 in opposition thereto are in the boom length direction. Since they are at the same position, unlike the conventional technique shown in FIG. 7, no bending moment acts on the boom 7 when the counterweight is attached.

Incidentally, the removal of the counterweight 3 is performed by the reverse procedure.

Second Embodiment (See FIGS. 4 and 5) Explaining only the differences from the first embodiment, the backstop brackets 21 and 21 are also used as spreader brackets in the second embodiment. It is becoming like this.

That is, the upper spreader 14 is provided with a pair of left and right mounting seats 27, 27 at the same intervals as the back stopper brackets 21, 21, and when the counterweight is attached or detached, the connecting seats 27, 27 are respectively connected with the link links. One end of 28, 28 is attached by a pin 29, 29. The boom side end 17 a of the back stopper 17 is attached to the bracket 21 inside the connecting link 28 by a pin 30 common to the link 28.

The other ends of the connecting links 28, 28 are attached to the back stopper brackets 21, 21 by the pins 30, 30.

As a result, the upper spreader 14 is connected to the middle part of the boom via the connecting links 28, 28. In this state, the attaching / detaching operation of the counterweight 3 is performed as in the case of the first embodiment.

According to this embodiment, as compared with the first embodiment, it is not necessary to provide a boom dedicated to the spreader mounting on the boom 7, so that the structure is simple and the boom weight can be reduced.

Other Embodiments In both the first and second embodiments, the hydraulic cylinder 6 is used as means for vertically moving the weight 3 up and down at the initial and final stages of attaching and removing the counterweight. As an alternative vertical elevating means, a rope is pulled out from a winch (for example, a main winding winch) mounted on the upper swing body 1, and the rope is passed through a sheave provided on the gantry peak pin 4 and its terminal is counterweighted. It is also possible to use means for vertically lifting the counterweight 3 by fixing the counterweight 3 to the counterweight 3, winding the winch, and rewinding.

Alternatively, in the case of a crane configured such that the interference between the counterweight 3 and the weight base 5 does not occur when the counterweight is attached or detached, the above vertical lifting means is omitted and the counterweight 3 is replaced by the gantry 2. You may make it move between the ground and the rear end of the rotating body only by the undulating motion of.

On the other hand, the bracket for attaching the upper spreader 14 to the middle portion of the boom 7 when the counterweight is attached or detached is most preferably provided at the same position in the boom length direction as the bracket 21 for the back stopper 17, but it is convenient. Depending on the case, it may be provided at a position near the bracket 21. Even in this case, the bending moment acting on the boom 7 can be remarkably reduced as compared with the case of the conventional technique shown in FIG.

[0036]

[Effect of device]

 As described above, according to the present invention, the spreader mounting portion is provided at the same position as or near the back stopper mounting portion on the rear surface of the boom, and the upper spreader is mounted on this spreader mounting portion when the counterweight is attached or detached. , When the counterweight is attached or detached, the distance between the point of action of the boom erecting force on the boom and the point of boom support by the back stopper can be made small (minimum 0).

Therefore, a large bending moment does not act on the boom, so that the boom strength can be suppressed lower than in the conventional case.

According to the second aspect of the invention, in addition to the above basic effects, the bracket serving as the boom-side mounting portion of the back stopper can also be used as the spreader mounting portion. In comparison, the structure is simple and the boom weight can be reduced.

[Brief description of drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is an enlarged sectional view taken along line III-III of FIG.

FIG. 4 is a view corresponding to FIG. 2 showing a second embodiment of the present invention.

5 is an enlarged sectional view taken along line VV of FIG.

FIG. 6 is a side view of the crane for explaining the related art.

FIG. 7 is a side view of a crane for explaining another conventional technique.

[Explanation of symbols]

1 Upper revolving structure 2 Gantry 4 Gantry peak pin at the top of gantry 3 Counterweight 7 Boom 17 Back stopper 18 Pin as a means for fixing the back stopper to a fixed length state 14 Upper spreader 15 Lower spreader 16 Guy cable 6 Counterweight and gantry Hydraulic cylinder for connecting to the top 21 Bracket for back stopper as a back stopper mounting part of boom 23 Spreader bracket as a spreader mounting part of boom 26 Pin as a means for fixing the upper spreader to the bracket 28 Connecting link (link member) 29 Pin for attaching one end of the connecting link to the upper spreader 30 Pin for attaching the other end of the connecting link to the bracket

Claims (2)

[Scope of utility model registration request] 1. An upper revolving structure is mounted on a lower traveling structure,
This upper revolving structure is provided with a detachable counterweight at the rear end, a boom at the front end, and a gantry capable of undulating between the boom and the counterweight. A back stopper that restricts the maximum upright angle of the boom is provided between the back stopper and a means for fixing the stopper to a constant length state is provided at the back stopper, while a boom hoisting rope that hoists the boom is provided. It is hung between both upper and lower spreaders, the upper spreader is fastened to the boom tip through the guy cable, the lower spreader is fastened to the top of the gantry, and the counterweight and the gantry top are attached and removed when the counterweight is attached and removed. In a crane having connecting means for connecting, in the boom length direction on the back surface of the boom, A spreader mounting portion to which the upper spreader is mounted when the counterweight is mounted and dismounted is provided at the same position as or in the vicinity of the boom-side mounting portion of the back stopper, and the upper spreader can be mounted to and dismounted from the spreader mounting portion. A counterweight attaching / detaching device for a crane, characterized in that it is provided with means for fixing. 2. A bracket serving as a boom-side mounting portion and a spreader mounting portion of a back stopper is provided on a rear surface of the boom, and a means for fixing the upper spreader to the bracket has a link member and one end of the link member. The counterweight attaching / detaching device for a crane according to claim 1, wherein the counterweight attaching / detaching device comprises a pin attached to the bracket and a pin attaching the other end of the link member to the upper spreader.