JP4625163B2 - Mobile crane hoisting cylinder load reduction device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hoisting cylinder load reducing device that reduces the load on the hoisting cylinder during a lifting operation in a mobile crane.
[0002]
[Prior art]
As a conventional technique for reducing the load on the hoisting cylinder during a suspended load operation by a mobile crane, for example, a technique described in Japanese Patent No. 2759692 is known.
[0003]
This is provided with a telescopic boom that is lifted and lowered by a hoisting cylinder on an upper swing body of a crane, and further provided with a winch of a rope that is suspended via the boom head of the telescopic boom on the upper swing body. After hanging from the boom head and hanging around between the hanging hook, the folded end of the rope extends beyond the boom head to the rear side of the upper swing body, and the upper swing body rear side rising part It winds around the sheave provided at the top and the sheave provided at the boom head sequentially, and the folded end is attached to the boom head.
[0004]
As a result, a part of the tension generated in the rope due to the suspended load acts as a bending moment for raising the telescopic boom, and the load acting on the hoisting cylinder can be reduced.
[0005]
[Problems to be solved by the invention]
By the way, in a mobile crane, the operation | work of changing the number of hooks of the rope hung around the hanging load hook suspended from the boom head may be required. That is, since the maximum load that can be applied to one wire is constant, the minimum required number of wires is determined from the weight of the suspended load. On the other hand, an unnecessarily large number of wire hooks slows the lifting / lowering speed of the hanging load hook and causes a reduction in work efficiency. Therefore, the number of hanging hook wire hooks is changed according to the weight of the hanging load at that time. is required.
[0006]
However, in the hoisting cylinder load reducing device of the above-mentioned Japanese Patent No. 2759692, after the rope suspended from the winch of the upper swinging body through the boom head of the telescopic boom is hung around the hanging load hook, The end portion of the rope extends beyond the boom head to the rear side of the upper swing body, and the sheave provided at the top of the upper swing body rear side rising portion and the sheave provided on the boom head in turn. Since the winding end is attached to the boom head, it is extremely difficult to change the number of wire hooks of the hanging load hook. That is, in order to change the number of wire hooks for the hanging load hook, it was necessary to unwind all the wires after extending to the rear side of the upper swing body over the boom head described above once with a winch. . And after changing the number of wire hooks of the hook for hanging loads, it was necessary to route the wire after extending the boom head to the rear side of the upper swing body again.
[0007]
Thus, the present invention can reduce the load acting on the hoisting cylinder in the same manner as the above-described prior art, and reduce the hoisting cylinder load of the mobile crane that can easily change the number of wire hooks of the hanging hook. The device is to be provided.
[0008]
[Means for Solving the Problems]
The invention of claim 1 of the present application is a mobile crane in which a telescopic boom is pivotably supported on a swivel of a mobile crane, and a hoisting cylinder is interposed between the telescopic boom and the swivel. An upper auxiliary sheave is provided at the tip of the base boom of the boom, a lower auxiliary sheave is provided at the upper part of the swivel base, and a wire rope that is fed and unwound from a winch mounted on the swivel base is connected to the upper auxiliary sheave and the lower auxiliary sheave. After hanging around, it is hung through the upper and lower sheaves provided on the boom head of the telescopic boom, and the wire rope is hung between the boom head lower sheave and the hanging load hook. The wire rope end is locked to the boom head or the hanging load hook.
[0009]
With this configuration, the wire rope that is fed and unwound from the winch mounted on the swivel is hung between the upper auxiliary sheave and the lower auxiliary sheave, so a part of the tension generated on the rope due to the suspended load or the like However, it acts as a back moment for raising the telescopic boom, and the load acting on the hoisting cylinder can be reduced. Then, after the wire rope is hung between the boom head lower sheave and the hanging load hook, the end of the wire rope is locked to the boom head or the hanging load hook. Even when changing the number of hooks to be hooked, the wire can be changed by simply releasing the end of the wire rope, so that the work is facilitated.
[0010]
Further, the invention of claim 2 of the present application is a mobile crane in which a telescopic boom is pivotally supported on a swivel of a mobile crane so as to be raised and lowered, and a hoisting cylinder is interposed between the telescopic boom and the swivel. An upper auxiliary sheave is provided at the base boom tip of the telescopic boom, a lower auxiliary sheave is provided at the upper part of the swivel base, and wire ropes fed and unwound from the main winch and sub winch mounted on the swivel base are respectively provided in the upper auxiliary sheave. After hanging between the sheave and the lower auxiliary sheave, it is suspended via the upper and lower sheaves provided on the boom head of the telescopic boom, and further between the boom head lower sheave and the hanging load hook. A wire rope is wound around, and the end of the wire rope is locked to the boom head or the hanging load hook.
[0011]
With this configuration, even in super-heavy work where a main winch and a sub winch are used simultaneously to lift the same suspended load, the wire rope that is fed and unwound from the winch mounted on the swivel is connected to the upper auxiliary sheave and the lower portion. Since it is hung between the auxiliary sheaves, part of the tension generated on the rope due to the suspended load acts as a back moment for raising the telescopic boom, and the load acting on the hoisting cylinder can be reduced. . The wire rope is hung between the boom head lower sheave and the hanging load hook at the end of the wire, and then the wire rope end is locked to the boom head or the hanging load hook. Therefore, even when changing the number of wire hooks of the hanging load hook, the wire can be changed only by releasing the end of the wire rope, so that the operation is facilitated.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a mobile crane 1 equipped with a hoisting cylinder load reducing device according to an embodiment of the present invention. The mobile crane 1 pivotally supports the telescopic boom 3 around the fulcrum 19 of the swivel base 2, and the hoisting cylinder 4 is interposed between the telescopic boom 3 and the swivel base 2. Reference numeral 10 denotes a main winch mounted on the rear part of the swivel base 2, and 11 denotes a sub winch. Reference numeral 6 denotes an upper auxiliary sheave attached to the distal end portion of the base boom 5 of the telescopic boom 3, and a sheave case 15 that is swingable via a pin 12 to a support 7 attached to the distal end portion of the base boom 5. It consists of a plurality of sheaves 13 arranged to freely rotate around the pin 14. Reference numeral 8 denotes a lower auxiliary sheave attached to the upper part of the swivel base 2, and a sheave case that is swingable via a pin 16 on a support 9 attached to the rear part of the winches 10, 11 of the swivel base 2. 17 is composed of a plurality of sheaves 13 arranged to freely rotate around a pin 18.
[0013]
22 is an upper sheave provided on the boom head 21 at the tip of the top boom 20, and 23 is a lower sheave. Reference numeral 26 denotes a hanging load hook. In this embodiment, a hook side additional sheave 25 is connected by a support 35 and is extended above the hanging load hook 26. Reference numeral 24 denotes a boom head side extension sheave that is added to the boom head lower sheave 23 in correspondence with the hook side extension sheave, and is suspended below the boom head lower sheave 23 by a support 30. .
[0014]
Next, a method of wrapping the main wire rope 31 and the sub wire rope 32 that are fed and unwound from the main winch 10 and the sub winch 11 will be described. Here, FIG. 2 is a view taken in the direction of arrow A in FIG. 1 and is a view for explaining the wire rope wrapping between the upper auxiliary sheave 6 and the lower auxiliary sheave 8 as viewed from the back side of the telescopic boom 3. is there. As shown in FIG. 2, in the upper auxiliary sheave 6, a plurality of sheaves 13 are arranged on the left and right sheaves 13 </ b> L and the right sheave 13 </ b> R on the left and right sides of the sheave case 15. Further, with respect to the lower auxiliary sheave 8 as well, a plurality of sheaves 13 are arranged on the left and right sides of the sheave case 17 at the target positions on the left sheave 13L and the right sheave 13R.
[0015]
On the other hand, FIG. 3 is a view as viewed in the direction of arrow B in FIG. 1 and shows the wire rope between the lower sheave 23 of the boom head 21 and the hanging load hook 26 and between the boom head side extension sheave 24 and the hook side extension sheave 25. It is a drawing explaining the wrapping.
[0016]
The main wire rope 31 fed out from the main winch 10 is hung on the lowest sheave of the left sheave 13L of the upper auxiliary sheave 6 and then hung on the lower sheave of the left sheave 13L of the lower auxiliary sheave 8. Is done. After that, the main wire rope 31 is guided to the upper sheave 22 of the boom head 21 after being multiplied between the upper auxiliary sheave 6 and the lower auxiliary sheave 8 by a multiplier corresponding to the number of sheaves. As described above, the main wire rope 31 is wound around the swivel base 2 and the telescopic boom 3 a plurality of times.
[0017]
After the sub-wire rope 32 fed out from the sub-winch 11 is routed between the right sheave 13R of the upper auxiliary sheave 6 and the right sheave 13R of the lower auxiliary sheave 8 as in the case of the main wire rope 31 described above. Then, it is guided to the upper sheave 22 of the boom head 21. That is, the sub wire rope 32 is wound around the swivel base 2 and the telescopic boom 3 a plurality of times.
[0018]
The main wire rope 31 guided to the upper sheave 22 of the boom head 21 is hung between the boom head lower sheave 23 and the sheave 36 of the hanging hook 26 and between the boom head side auxiliary sheave 24 and the hook side auxiliary sheave 25. After that, in the present embodiment, the base boom 5 is connected to the tip support 34 via the rope end 33. Of course, the end portion of the main wire rope 31 may be connected to the tip end portion of the top boom 20 or an appropriate position of the hanging load hook 26.
[0019]
Similarly, the sub-wire rope 32 led to the upper sheave 22 of the boom head 21 passes between the boom head lower sheave 23 and the sheave 36 of the hanging load hook 26 and between the boom head side auxiliary sheave 24 and the hook side auxiliary sheave 25. After being hung, it is connected to the tip of the base boom 5.
[0020]
A hooking wire rope 29 is hung on the hook 27 of the hanging load hook 26, and the hanging load 28 is lifted.
[0021]
As shown in FIG. 1, when the suspended load 28 is grounded, the main wire rope 31 and the sub wire rope 32 are placed between the boom head 21 and the suspended load hook by the weight of the suspended load such as the suspended load 28 and the suspended load hook 26. A tension corresponding to the number of wires is generated. At this time, the same tension is also generated in the main wire rope 31 and the sub wire rope 32 that are hung between the upper auxiliary sheave 6 at the tip of the base boom 5 and the lower auxiliary sheave 8 at the top of the swivel base 2. The tension of the wire rope between the telescopic boom 3 and the swivel base 2 generates a back moment to cause the telescopic boom 3 around the fulcrum 19 with respect to the telescopic boom 3, but as described above, the main wire rope Since 31 and the sub-wire rope 32 are wound around the swivel base 2 and the telescopic boom 3 a plurality of times, respectively, a back moment that is increased according to the multiplying number is generated. As a result, the load on the undulating cylinder 4 is greatly reduced.
[0022]
Generally, the maximum load of the hoisting cylinder of a mobile crane is generated when the maximum rated load is suspended, and the size of the hoisting cylinder is determined by the size of the maximum load. However, in the operation of the mobile crane, although the frequency with which the maximum rated load is suspended is very low, the mobile crane without the hoisting cylinder load reducing device as in the present invention is not necessary for normal work. A undulating cylinder of the size was installed. When the undulation cylinder load reducing device of the present invention is installed, the load of the undulation cylinder can be reduced as compared with the conventional case when suspending the maximum rated load, so that the undulation cylinder of a smaller size can be used and the cost of the undulation cylinder is reduced. In addition, the lifting performance is improved by reducing the weight.
[0023]
The embodiment described above uses the main winch 10 and the sub winch 11 at the same time, and corresponds to the invention described in claim 2, but uses one winch and one wire rope. Of course, the invention of claim 1 constituting the undulating cylinder load reducing device can be implemented in the same manner, and the same effect can be obtained.
[0024]
In the above-described embodiment, the case where the upper auxiliary sheave 6 is provided at the tip of the base boom 5 has been described. However, the upper auxiliary sheave 6 may be provided at the tip of the top boom 20 as a matter of course. Further, of course, the lower auxiliary sheave 8 may be installed on the upper part of the counterweight attached to the rear part of the swivel base 2.
[0025]
【The invention's effect】
Since it is constructed and operated as described above, in the hoisting cylinder load reducing device of the mobile crane of the present invention, the wire rope that is fed and unwound from the winch mounted on the swivel is connected to the upper auxiliary sheave and the lower auxiliary sheave. Since part of the tension generated on the rope due to the suspended load acts as a back moment for raising the telescopic boom, the load acting on the hoisting cylinder can be reduced and the boom can be reduced. After the wire rope is hung between the head lower sheave and the hanging hook, the end of the wire rope is locked to the boom head or the hanging hook. Even when changing the number of hooks, the wire can be changed simply by unlocking the end of the wire rope, which facilitates the work. And is're.
[0026]
Also, in super heavy work where the main winch and the sub winch are used simultaneously to lift the same suspended load, the wire rope that is fed and unwound from the winch mounted on the swivel base is connected to the upper auxiliary sheave and the lower auxiliary sheave. Since a part of the tension generated in the rope due to the suspended load acts as a back moment for raising the telescopic boom, the load acting on the hoisting cylinder can be reduced, After the wire rope is hung between the boom head lower sheave and the hanging hook, the end of the wire rope is locked to the boom head or the hanging hook. Even when changing the number of wires, the wire can be changed simply by unlocking the end of the wire rope. It has become the easy.
[Brief description of the drawings]
FIG. 1 is a side view of a mobile crane equipped with a hoisting cylinder load reducing device according to an embodiment of the present invention.
FIG. 2 is a view taken in the direction of arrow A in FIG.
FIG. 3 is a view taken in the direction of arrow B in FIG. 1;
[Explanation of symbols]
1 Mobile crane, 2 swivel base, 3 telescopic boom, 4 hoisting cylinder, 5 base boom, 6 upper auxiliary sheave, 7 9 support, 8 lower auxiliary sheave, 10 main winch, 11 sub winch, 12 14 16 18 pin, 13 13L 13R sheave, 15 17 sheave case, 19 telescopic boom fulcrum, 20 top boom, 21 boom head, 22 boom head upper sheave, 23 boom head lower sheave, 24 boom head side additional sheave, 25 hook side additional sheave, 26 hanging Load hook, 27 hook, 28 suspended load, 29 sling wire rope, 30 35 support, 31 main wire rope, 32 sub wire rope, 33 cable end, 34 support, 36 sheave for hanging load hook

Claims (2)

A mobile crane in which a telescopic boom is pivotably supported on a swivel of a mobile crane, and a hoisting cylinder is interposed between the telescopic boom and the swivel. A sheave is provided, a lower auxiliary sheave is provided at the upper part of the swivel base, and a wire rope that is fed and unwound from a winch mounted on the swivel base is hung between the upper auxiliary sheave and the lower auxiliary sheave, and then the expansion and contraction is performed. The boom is hung through upper and lower sheaves provided on the boom head of the boom, and the wire rope is hung between the boom head lower sheave and the hanging load hook. A hoisting cylinder load reducing device for a mobile crane, wherein the device is engaged with a hook for hanging load. A mobile crane in which a telescopic boom is pivotably supported on a swivel of a mobile crane, and a hoisting cylinder is interposed between the telescopic boom and the swivel. A sheave is provided, a lower auxiliary sheave is provided at the upper part of the swivel base, and wire ropes that are fed and unwound from the main winch and the sub winch mounted on the swivel base are respectively hung between the upper auxiliary sheave and the lower auxiliary sheave. After that, it is suspended through upper and lower sheaves provided on the boom head of the telescopic boom, and further, the wire rope is hung between the boom head lower sheave and the hanging load hook, and the wire rope end portion A hoisting cylinder load reducing device for a mobile crane, wherein the hoisting cylinder is locked to the boom head or the hanging load hook.

Images