JP5635331B2 - Mobile crane - Google Patents

Description

  The present invention relates to a mobile crane. More specifically, the present invention relates to a mobile crane that improves the lifting ability by suppressing the vertical deflection and lateral deflection of the boom.

The mobile crane which is the object of the present invention is a crane mounted on a traveling vehicle body. Such a mobile crane includes a truck crane using a wheeled vehicle body, a wheel crane, and a crawler using a crawler vehicle body. Type cranes.
Most of them have a structure in which a swivel is mounted on the traveling vehicle body and a boom is mounted on the swivel so that the boom can be swung up and down, but the boom can be raised and lowered without using the swivel. The thing of the structure attached freely is also included.
The boom is of a multi-stage type, and includes a boom whose length can be changed by adding a boom without incorporating a hydraulic cylinder, in addition to a boom that automatically expands and contracts with a hydraulic cylinder. Further, a boom that further extends the boom length by adding a special jib to the tip of the boom is also included.

Mobile cranes have multiple booms to increase the length of expansion and contraction, thereby increasing the lift and enabling unloading from high places and unloading from high places.
Such an increase in the lift of the crane increases the applicability of the crane in construction and other industrial fields.
However, the increase in the number of booms in a mobile crane and the resulting increase in the length of expansion and contraction have brought a limit in terms of the structural strength of the boom.

In crane work, it is possible to work in all directions around the aircraft by turning the boom, and it is possible to work in high places and far away by raising and lowering the boom, in a three-dimensional space. Cargo handling is possible.
However, when the boom is laid down, a vertical bending moment for bending the boom downward is increased, and the boom is easily bent downward.
On the other hand, when the boom is raised, the force that compresses the boom itself increases, and when an external force such as wind or unbalanced load acts on the boom, the lateral bending moment for bending the boom laterally increases. Deflection is likely to occur.

In order to suppress the above-described longitudinal bending moment and lateral bending moment, the conventional techniques of Patent Documents 1 to 3 have been proposed.
In the prior art of Patent Document 1, a gantry is erected on the upper surface of a jib (also called a boom, but the technical meaning is the same), and hung between a hook suspended from the tip of the jib and a winch on a swivel. The rope is also hung from the jib tip to the pulley at the top of the gantry. A rope stretched between the end of the jib and the gantry is provided to provide resistance to the longitudinal bending moment of the jib and to suppress the longitudinal bending of the jib.

The prior art of Patent Document 2 has the same configuration as Patent Document 1 in that a tension base (corresponding to the gantry) is provided on the upper surface of the jib, but in addition, a rope connected to the tip of the jib is stretched. It leads to a winch provided at the base of the tensioning table via a pulley at the top of the table. This rope is different from the rope for cargo handling, and the longitudinal bending of the jib can be effectively suppressed by adjusting the tension with a winch.
In addition, there is a description that lateral stability can be obtained with respect to the jib, and the problem of lateral stability of the jib is also indicated.

The above-mentioned Patent Documents 1 and 2 mainly suppress the vertical deflection of the boom, while Patent Document 3 mainly deals with the prevention of the horizontal deflection of the boom.
That is, in the prior art of Patent Document 3, as shown in FIG. 10, the wire support members 102 and 102 ′ are arranged on the upper surface of the jib 101. The tension wire supports 102 and 102 'are inclined in the lateral direction (angle α), are also inclined in the front-rear direction (angle β), and the inclination angles α and β are adjustable. The ropes 106, 107 and 106 ′, 107 ′ are connected between the free end and the base portion of the jib 101 via the tension wire supports 102, 102 ′. These ropes 106, 107 and 106 ′, 107 ′ suppress lateral deformation of the jib 101.

  By the way, in Patent Document 3, each of the tension wire supports 102 and 102 ′ extends while being inclined obliquely above the main jib 101, but both of them are free ends without being fixed. Therefore, the tension by the suspended load may act, and the jib may bend irregularly due to the ups and downs of the jib or the inertia of the turning. As described above, when the tension support members 102 and 102 'are bent, the ropes 106 and 107 and the ropes 106' and 107 'are loosened in tension and imbalanced in tension, thereby suppressing the lateral deformation of the jib 101. Is reduced.

Japanese Patent Publication No. 56-43995 Japanese Patent Laid-Open No. 57-184092 JP 2001-58791 A

  In view of the above circumstances, an object of the present invention is to provide a mobile crane that can effectively prevent a horizontal deflection of a boom and can have a high lifting capacity.

A mobile crane according to a first aspect of the present invention includes a traveling vehicle body and a telescopic boom attached to the traveling vehicle body so as to be raised and lowered, and the telescopic boom extends from the main boom to the distal end. A mobile crane comprising a sub-boom arranged on the main boom, a tension mast comprising a left mast and a right mast pivotally supported on the base, and the telescopic boom via the tension mast A tension rope stretched between the base end portion and the tip end portion, the left mast is a member extending obliquely to the left with respect to the longitudinal direction of the main boom, and the right mast is A member extending obliquely to the right with respect to the longitudinal direction of the main boom, wherein the left mast and the right mast are both attached to the main boom via a turntable, and the turntable is connected to the main boom. Boom long axis Is rotatable in a vertical line around orthogonal to the tension rope, and left rope is stretched through the left mast made if Toka right rope is stretched over the right mast, wherein An interval holding means for holding an interval between the left mast and the right mast is provided.
The mobile crane of the second invention is characterized in that, in the first invention, the interval holding means is an interval holding stay formed of a bar whose length is invariable.
The mobile crane according to a third aspect is characterized in that, in the first aspect, the gap holding means is a gap holding cylinder constituted by a hydraulic cylinder having a variable length .

According to the first invention, the following effects are obtained.
a) Since the interval holding means for maintaining the interval between each other is arranged between the left mast and the right mast, the left and right masts will not bend even if vertical or horizontal deflection occurs in the telescopic boom. The distance between the tips of each other does not increase or decrease. For this reason, since the front-end | tip position of the right and left mast with respect to an expansion-contraction boom is hold | maintained without fluctuation | variation, the vertical deflection and horizontal deflection of an expansion-contraction boom can be suppressed stably and effectively.
b) The left and right masts can be rotated so as to face each other in the lateral deflection direction of the boom via the turning table. For this reason, the tension of the left and right ropes can be evenly distributed to the boom, and the vertical deflection of the boom can be effectively prevented.
According to the second invention, since the length of the gap holding means is unchanged, the gap between the left and right masts can be held unchanged, and the gap holding means is provided in addition to inheriting the boom vertical deflection and horizontal deflection control effects in the first invention. Since it is a bar, it can be made light weight and does not reduce the lifting ability of the telescopic boom.
According to the third invention, since the distance holding means is a hydraulic cylinder having a variable length, the distance between the left and right masts can be variably adjusted. By reducing the distance, the vertical height from the main boom is increased and the vertical deflection is reduced. By increasing the suppression effect or widening the interval, the width perpendicular to the main boom can be widened to increase the lateral deflection prevention effect .

It is a perspective view of the mobile crane L which concerns on the 1st example of the deflection | deviation prevention theory disclosed to this specification . It is a rear view of the mobile crane L shown by FIG. It is a perspective view of the mobile crane M which concerns on the 2nd example of the deflection | deviation prevention theory disclosed to this specification . FIG. 4 is a rear view of the spacing cylinder 42 shown in FIG. 3. 1 is a side view of a mobile crane N according to a first embodiment of the present invention. It is a rear view of the mobile crane N which concerns on 1st Embodiment shown by FIG. It is explanatory drawing of the side deflection prevention operation | movement of the mobile crane N which concerns on 1st Embodiment . It is a rear view of the tension mast part of the mobile crane P which concerns on the 3rd example of the bending | flexion prevention theory disclosed to this specification . It is explanatory drawing of the side deflection prevention operation | movement of the mobile crane P of a 3rd example . It is explanatory drawing of the prior art of patent document 3. FIG.

Next, an embodiment of the present invention will be described with reference to the drawings.
Hereinafter, the present invention and a first implementation form of application to truck cranes, the first to third example of the deflection preventing theory explained.

(Basic structure of mobile crane)
Also not a, the basic structure of the mobile crane L as truck crane will be described with reference to FIG. Reference numeral 1 denotes a known traveling vehicle body. The traveling vehicle body 1 is provided with a prime mover for driving, a driver's cab, wheels, and an outrigger 2 for ensuring stability during crane operation. A swivel 3 is mounted on the upper surface of the traveling vehicle body 1 so that it can turn 360 ° in a horizontal plane by a hydraulic motor or the like. In addition to the counterweight 4, a crane cab (not shown), a winch, and other equipment are provided on the swivel base 3.

  An extendable boom 5 is attached to the swivel base 3 so as to be raised and lowered. The telescopic boom 5 includes a main boom 5A on the base end side and a plurality of stages of sub-booms 5B, 5C, and 5D that are telescopically inserted into the main boom 5A. In the illustrated example, the number of sub booms 5B to 5D is three, but may be two or less, or four or more. The expansion and contraction of each sub boom 5B to 5D is performed by a hydraulic cylinder.

  A base end portion of the main boom 5A is pivotally supported on the swivel base 3 by a pin 6, and a hoisting cylinder 7 composed of a hydraulic cylinder is attached between the main boom 5A and the swivel base 3. When the hoisting cylinder 7 is extended, the telescopic boom 5 stands up, and when the hoisting cylinder 7 is contracted, the telescopic boom 5 falls.

A wire rope provided with a hook (not shown) is suspended from the tip of the telescopic boom 5, that is, the boom head 5E formed at the tip of the sub boom 5D. And is wound up by a winch (not shown).
By combining the raising and lowering of the hook by the winch and the undulation, turning, and expansion / contraction of the telescopic boom 5, it is possible to unload and unload in the three-dimensional space.

(First example of deflection prevention theory)
Next, a first example of deflection prevention and theory will be described.
As shown in FIGS. 1 and 2, reference numeral 10 denotes a tension mast, which is attached to an upper surface of the main boom 5 </ b> A and an intermediate portion in the longitudinal direction. In the present invention, the attachment position of the tension mast 10 is not limited to the intermediate portion in the longitudinal direction of the main boom 5A, and may be any portion from the proximal end to the distal end in the longitudinal direction.

  The tension mast 10 includes a pair of left and right left masts 10L and 10R. The left and right masts 10L and 10R are both mounted on the upper surface of the main boom 5A via appropriate hinges so that they can be raised and lowered, and a raising / lowering operation is performed by a raising / lowering angle adjusting cylinder described later. The tension mast 10 is a facility for tensioning a tension rope 20 to be described later so as to suppress lateral deflection and vertical deflection of the telescopic boom 5.

A pulley 13 is attached to the upper ends of the left and right masts 10L and 10R of the tension mast 10. On the other hand, a locking hook 15 is provided at the tip of the telescopic boom 5, for example, the tip of the sub boom 5D or the boom head 5E (hereinafter referred to as the boom tip).
A pair of left and right winches 14 are attached to the base of the main boom 5A. The winch 14 may be attached to each mast 10L, 10R.

  The tension rope 20 includes a left rope 20L and a right rope 20R. The ropes 20L and 20R are respectively fed out from the left and right winches 14, are extended to the boom tips via the pulleys 13 at the upper ends of the masts 10L and 10R, and are locked to the locking hooks 15.

  Between the main boom 5A and the mast 10R, an undulation angle adjusting cylinder 36, which is a hydraulic cylinder, is attached. By this undulation angle adjusting cylinder 36, the undulation angle of the mast 10R with respect to the main boom 5A can be variably adjusted. Yes. In other words, it is possible to change the posture between the standing position that stands upward with respect to the main boom 5A and the lying position that has fallen forward so as to be parallel to the main boom 5A.

Between the left mast 10L and the right mast 10R, an interval holding stay 41 made of a bar material as an interval holding means is attached in the vicinity of each upper end. The distance holding stay 41 has an invariable length and holds the upper ends of the left and right masts 10L and 10R so as not to open or narrow.
The interval maintaining stay 41 using this bar is lightweight, has a high effect of preventing the masts 10L and 10R from being bent, and has a feature that the lifting ability of the telescopic boom 5 is not lowered.

In this example , the left and right winches 14 are driven to adjust the lengths of the left and right ropes 20L and 20R in accordance with the boom extension / contraction length and to obtain a necessary tension. That is, when the telescopic boom 5 is extended, the winch 14 is rotated forward so that a certain amount of tension is applied while the ropes 20L and 20R are extended, and when the telescopic boom 5 is contracted, the winch 14 is rotated by the ropes 20L and 20R. While rewinding 20R, reverse so that some tension remains. In such control, the hydraulic motor for driving the winch is always driven to the hoisting side at a low pressure, the rope is pulled out against the driving force when the boom is extended, and the rope is driven at the low driving force when the boom is contracted. It can be realized by winding, and may be realized by feedback control that detects the rope tension and falls within an allowable range, and such a control method is arbitrary.

  By the way, the boom of a crane becomes prominent in vertical deflection in a lying state, and tends to cause lateral deflection in a standing state. For this reason, in the crane work in which the telescopic boom 5 is laid down, the vertical deflection of the boom is suppressed within the allowable range by the tension of the left and right ropes 20L and 20R, and in the crane work in which the telescopic boom 5 is raised, When the lateral deflection of the boom occurs, the lateral deflection resistance can be increased by the tension of the rope on the opposite side of the lateral deflection, and the occurrence of the lateral deflection of the boom can be prevented.

And in the mobile crane L of this example , since the space | interval holding | maintenance stay 41 which hold | maintains a mutual space | interval is arrange | positioned between the left mast 10L and the right mast 10R, a vertical deflection and a horizontal deflection arise in the boom, The left and right masts 10L, 10R receive a force due to the tension of the left and right ropes 20L, 20R, and the gap between the ends of the left and right masts 10L, 10R does not become wider or narrower. For this reason, since the tip positions of the left and right masts 10L, 10R with respect to the telescopic boom 5 are held without fluctuation, the positions of the left and right ropes 20L, 20R with respect to the telescopic boom 5 can also be held without fluctuation, stably and effectively. Both vertical and horizontal deflection of the boom can be suppressed.

(Second example of deflection prevention theory)
A mobile crane M according to a second example of the deflection prevention theory will be described with reference to FIGS.
In this example , as an interval holding means for the left and right masts 10L and 10R constituting the tension mast 10, an interval holding cylinder 42 is configured by a hydraulic cylinder. The distance holding cylinder 42 is different from the distance holding stay 41 of the first embodiment in that the length can be adjusted.

The left and right masts 10L, 10R are attached to the main boom 5A via a joint 30 so that the vertical boom of the telescopic boom 5 and the distance between the left and right masts 10L, 10R can be adjusted. The joint 30 includes a undulation joint and an inclination joint, and the undulation joint is rotatably connected to a fixed bracket 31 fixed to the upper portion of the main boom 5A via a pin 32. The joint for tilting has a structure in which the base of the mast 10R is pivotally supported on the rotating bracket 33 via a pin 34. In addition, the joint 30 having any structure may be used as long as the left and right masts 10 </ b> L and 10 </ b> R can be tilted in the front-rear direction and the lateral direction.
Since the rest of the configuration is substantially the same as in the first embodiment, the same reference numerals are assigned to the same members, and descriptions thereof are omitted.

In this example , since the interval holding means is a hydraulic cylinder having a variable length, the interval between the left and right masts 10L and 10R can be variably adjusted. By reducing the interval, the vertical height from the main boom 5A can be increased, By widening, the width orthogonal to the main boom 5A can be widened. For this reason, the distance between the left and right masts 10L and 10R is reduced when the telescopic boom 5 is in a lying state to increase the vertical deflection restraining drop, and when the telescopic boom 5 is in the standing state, the distance between the left and right masts 10L and 10R is increased. It can be used to increase the effect of preventing lateral deflection.

(First Embodiment)
The mobile crane N of 1st Embodiment which concerns on this invention is demonstrated based on FIG. 5 and FIG.
The present embodiment has the following features in addition to inheriting the technical ideas of the first and second examples of the deflection prevention theory.
In the present embodiment, the left mast 10L and the right mast 10R constituting the tension mast 10 are both attached to the main boom 5A via the turntable 51, and the turntable 51 is the long axis of the main boom 5A. It is rotatable around a vertical line perpendicular to the axis.
Interval holding means may be used apart holding stay 41 shown, although not shown in FIG. 6 may be used apart holding cylinder 42 shown in FIG.

The turning table 51 only needs to be turned on the main boom 5 </ b> A so as to change the direction to the right and left by a certain range of angles, and does not need to be turned completely.
Further, the swivel structure may arbitrarily adopt known technical means such as support by a swivel bearing or the like and forward / reverse rotation by a hydraulic motor.
Since the rest of the configuration is substantially the same as in the first embodiment, the same reference numerals are assigned to the same members, and descriptions thereof are omitted.

In the present embodiment, when lateral deflection occurs in the telescopic boom 5, the left and right masts 10L and 10R can be directly opposed to the laterally bent boom tip.
That is, as shown in FIG. 7, when leftward lateral deflection occurs in the telescopic boom 5, when the left and right masts 10 </ b> L and 10 </ b> R are rotated counterclockwise via the turning table 51, the lateral deflection of the boom is achieved. It is possible to face the direction. Further, when the rightward lateral deflection of the telescopic boom 5 occurs, the left and right masts 10L and 10R can be made to face each other in the lateral deflection direction of the boom by rotating the turning table 51 clockwise.
As described above, when the left and right masts 10L and 10R are aligned in the lateral deflection direction of the telescopic boom 5, the tension of the left and right ropes 10L and 10R can be evenly distributed to the boom, so that the vertical deflection of the boom is effective. Can be prevented.

(Third example of deflection prevention theory)
A third example of the deflection prevention theory will be described with reference to FIGS.
As shown in FIG. 8, the mobile crane P according to the present embodiment has tilt angle adjustment cylinders 37 attached to the left and right masts 10 </ b> L and 10 </ b> R constituting the tension mast 10. The inclination angle adjusting cylinder 37 is mounted between the masts 10L and 10R and the main boom 5A via a known uniaxial mounting bracket. In the illustrated embodiment, the left and right masts 10L, 10R do not undulate in the front-rear direction of the main boom 5A. However, when the undulation angle adjustment cylinder 36 is attached and undulated, the inclination angle adjustment cylinder 37 is provided. May be attached via a spherical bearing or the like.

Between the upper ends of the left and right masts 10L, 10R, a spacing cylinder 42 constituted by a hydraulic cylinder is attached. In addition to following the inclination angle variation of the left and right masts 10L, 10R, the spacing cylinder 42 plays a role of preventing the bending by connecting the tip portions of the left and right masts 10L, 10R opened at every inclination angle.
As shown, the winch 14 may be attached to each of the masts 10L and 10R, or may be installed at the rear end of the main boom 5A.
Although not shown, when the winch 14 is attached to the left and right masts 10 </ b> L and 10 </ b> R, a stay rope or a stay stay for keeping the left and right masts 10 </ b> L and 10 </ b> R so as not to fall forward of the telescopic boom 5 is appropriately attached.
The base ends of the left and right masts 10L, 10R are attached to a common bracket 33 with a common pin 35, but this attachment structure can be used if the masts 10L, 10R are allowed to tilt in the lateral direction. Such a structure may be arbitrarily adopted, and a joint 30 as shown in FIG. 4 may be employed.

Next, a method for preventing the horizontal deflection of the boom according to this example will be described.
As shown in FIG. 9, when the telescopic boom 5 causes lateral deflection to the left side, the right mast 10R, which is the opposite side of the lateral deflection, is tilted so as to lie down sideways. This tilting operation is performed by extending the tilt angle adjusting cylinder 37 of the left mast 10L and contracting the tilt angle adjusting cylinder 37 of the right mast 10R. The crossing angle of the left mast 10L and the right mast 10R is the same as that before and after the tilting operation. And constant.

When the right mast 10R is inclined sideways as described above, as shown in FIG. 9, the crossing angle δL at which the left rope 20L intersects with the line connecting the boom tip in the lateral deflection state and the center of the tension mast 10 The crossing angle δR at which the right rope 20R intersects is different, the right crossing angle δR increases, and the left crossing angle δL decreases.
In this case, since the force to pull back the lateral deflection of the telescopic boom 5 by the right rope 20R is increased, the lateral deflection of the telescopic boom 5 is easily corrected or prevented.
When the telescopic boom 5 is deflected to the right, the left mast 10L may be inclined to the side. In this case, the lateral deflection correction principle is the same as described above.
Thus, in this embodiment, since the horizontal deflection prevention effect of the telescopic boom 5 is high, the lifting capacity of the crane can be improved.

(Other embodiments)
Next, another embodiment of the present invention will be described.
In the first embodiment, the interval holding stay 41 made of a bar is used as the interval holding means, but a rope may be used instead of the bar, and in that case, the upper ends of the left and right masts 10L and 10R are also used. It is possible to prevent each other from opening. For this reason, it is possible to prevent the left and right masts 10L and 10R from being bent and to prevent the lifting ability of the telescopic boom 5 from being lowered.

Prior you facilities embodiment has been described and illustrated only telescopic boom 5 multistage, the boom head 5E of the telescopic boom 5, also a crane equipped with a jib of replenishment only, the present invention can be applied.
Note that the jib dedicated to the extension includes a telescopic type using a hydraulic cylinder and a type whose length is variable by connecting a lattice type jib.
Further, the telescopic boom 5 itself may be of a non-automatic telescopic type in which a boom having a lattice structure is connected in multiple stages, in addition to the automatic telescopic type using a hydraulic cylinder. The meaning of the “sub-boom arranged at a position extending from the main boom to the tip” in the scope of the claims is intended to include non-automatic telescopic connection and non-automatic connection.

Before the mobile crane of you facilities embodiment, both have a swivel base 3, by the turning operation in addition to the stretch-relief of the telescopic boom 5 itself was achieved, thereby loading operation of the omnidirectional However, the object of the present invention includes those that do not have a swivel.
In short, if it is a crane boom that expands and contracts, the tension mast 10 and the tension rope 20 according to each embodiment of the present invention can be arbitrarily applied to improve its lifting ability.

Before you facilities embodiment is a truck crane with the track chassis as the vehicle body 1, but the crane cab (not shown mounted on a swivel base) and traveling cab are provided separately Of course, the present invention can also be applied to a hoist crane having a single cab that performs both crane operation and traveling operation on the same traveling vehicle body. These are wheeled mobile cranes.
A crane using a crawler type traveling vehicle body of a type different from the wheeled type is called a crawler crane, and the tension mast 10 and the tension rope 20 of the present invention can also be applied to the telescopic boom of this crawler crane. .

DESCRIPTION OF SYMBOLS 1 Traveling body 5 Telescopic boom 10 Tension mast 10L Left mast 10R Right mast 20 Tension rope 20L Left rope 20R Right rope 37 Inclination angle adjustment cylinder 41 Spacing holding stay 42 Spacing holding cylinder 51 Turning table

Claims (3)

A traveling vehicle body,
A telescopic boom attached to the traveling vehicle body in an up and down manner,
The telescoping boom is a mobile crane comprising a base-side main boom and a sub-boom arranged at a position extending from the main boom to the tip,
A tension mast consisting of a left mast and a right mast, the base of which is pivotally supported with respect to the main boom,
A tension rope stretched between the proximal end and the distal end of the telescopic boom via the tension mast;
The left mast is a member extending obliquely to the left with respect to the longitudinal direction of the main boom, and the right mast is a member extending obliquely to the right with respect to the longitudinal direction of the main boom,
The left mast and the right mast are both attached to the main boom via a turntable at the base.
The swivel table is rotatable around a vertical line perpendicular to the major axis of the main boom;
The tension rope consists of a left rope stretched through the left mast and a right rope stretched through the right mast,
A mobile crane characterized in that an interval holding means for maintaining an interval between each other is disposed between the left mast and the right mast. The mobile crane according to claim 1, wherein the gap holding means is a gap holding stay made of a bar having an invariable length. The mobile crane according to claim 1, wherein the gap holding means is a gap holding cylinder constituted by a hydraulic cylinder having a variable length .

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