JP2018095432A - Crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crane that can inhibit a load from swinging when lifting the load with a wire rope that is wound down from a boom even when deflection occurs in the boom.SOLUTION: In a crane 1, a control part 100 calculates a force component in a horizontal direction of tensile force in a main wire 21 and a sub-wire 25, respectively, based on the tensile force measured by a tensile force detector 121, a hanging angle measured by an angle detector 122 and a hanging length measured by a length detector 123 before starting lifting a load B up, and then drives a main winch 9 and a sub-winch 19 so as to make each force component in the horizontal direction even.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a crane. Specifically, the present invention relates to a crane that carries a load with a wire rope that is unwound from a boom.

  2. Description of the Related Art Conventionally, a boom, a wire rope spanned from the base end portion to the tip end portion of the boom, and a winch for winding and unwinding the wire rope are provided, and the baggage is lifted and transported by the wire rope. A crane is known.

  Moreover, when lifting a load with a crane, a technique for suppressing the swing of the load is known (see, for example, Patent Document 1 and Patent Document 2). However, since the techniques described in these patent documents are configured to lift a load with a wire rope that is suspended from a trolley, they can be applied to a crane that lifts a load with a wire rope that is suspended from a boom as described above. There wasn't. In addition, in the case of a crane that lifts a load with a wire rope that is unwound from the boom, the swing of the load may occur due to the deflection of the boom.

JP 2000-191275 A Japanese Patent Laid-Open No. 2003-329883

  The present invention has been made in view of the above situation, and the problem to be solved by the present invention is that the boom is deflected due to the swing of the load when the load is lifted by the wire rope suspended from the boom. It is to provide a crane that can be restrained even in the event of an accident.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

The first invention is
The boom,
A first wire rope that is bridged from the base end portion of the boom to the tip end portion and is wound down from the tip end portion;
A first winch for winding and unwinding the first wire rope;
A second wire rope spanned from the base end portion of the boom to the midway portion and wound down from the midway portion;
A second winch for winding and unwinding the second wire rope;
A tension measuring unit for measuring the tension of each of the first wire rope and the second wire rope;
A hanging angle measuring unit for measuring the hanging angle of each of the first wire rope and the second wire rope;
A suspended length measuring unit for measuring the suspended length of each of the first wire rope and the second wire rope;
A control unit for controlling the winding and unwinding of the first wire rope and the second wire rope by the first winch and the second winch,
A crane that lifts one load by the first wire rope and the second wire rope and allows the load to be transported,
Before the control unit starts lifting the luggage,
Based on the tension measured by the tension measurement unit, the suspension angle measured by the suspension angle measurement unit, and the suspension length measured by the suspension length measurement unit, the first wire Calculate the horizontal component of tension in each of the rope and the second wire rope,
The first wire rope by the first winch and the second winch, and the horizontal component of the tension in the first wire rope and the horizontal component of the tension in the second wire rope are equal. The winding and unwinding of the second wire rope are controlled.

The second invention is
When the horizontal component force of the tension in the first wire rope is zero, the control unit uses the second winch so that the minimum suspension length in which the tension in the second wire rope is not generated is obtained. The second wire rope is wound.

  The crane according to the first aspect of the invention can start lifting the load in the state where the horizontal component of the tension in the two wire ropes is equal even when the boom is bent. It is possible to prevent the swing (longitudinal swing) of the luggage.

  The crane which concerns on 2nd invention can start lifting of a load quickly, when the horizontal component of the tension | tensile_strength in the 1st wire rope has not arisen.

It is a side view which shows the crane at the time of lifting work. It is a control block diagram of a crane apparatus. It is a schematic explanatory drawing at the time of the lifting operation of the load when there is no deflection in the boom. It is a schematic explanatory drawing at the time of winding up a main wire at the time of the lifting work of the load | bag when a deflection | deviation arises in a boom. It is a schematic explanatory drawing at the time of winding up a subwire at the time of lifting work of a load when deflection occurs in a boom. It is a control flow figure at the time of the lifting work of a load.

  The technical idea of the present invention is that the crane 1 described below is a crane that lifts and carries a load with a wire rope that is wound from the tip of the boom and a wire rope that is wound from the middle part. The present invention can also be applied to other cranes having different configurations (for example, a crane having only the crane device 3 without the traveling body 2 described later).

  First, the structure of the crane 1 is demonstrated easily using FIG.1 and FIG.2. FIG. 1 shows the crane 1 during the lifting operation. FIG. 2 shows a control block diagram of the crane apparatus 3 in the crane 1.

The crane 1 is mainly configured as a crane vehicle including a traveling body 2 that constitutes a lower portion of the crane 1 and a crane device 3 that constitutes an upper portion.
The traveling body 2 includes a pair of left and right front tires 4 and a rear tire 5. Moreover, the traveling body 2 includes an outrigger 6 that is grounded and stabilized when performing the lifting work. Furthermore, the traveling body 2 includes an engine, a transmission, and the like in addition to the hydraulic actuator for driving them.

  The crane device 3 mainly includes a swivel including a swivel device (not shown), a boom 7 and a cabin 8. The crane apparatus 3 operates by transmitting the power of the engine mounted on the traveling body 2 through a hydraulic system (not shown).

  The boom 7 is disposed at the rear part of the crane device 3 so as to protrude forward. More specifically, the boom 7 can be raised and lowered along a undulation plane perpendicular to the turning plane by driving the undulation cylinder 13 (see FIG. 2). The boom 7 is configured to be extendable and retractable along the longitudinal direction of the boom 7 by driving an extendable cylinder 14 (see FIG. 2).

The crane apparatus 3 includes a cabin 8 on the right side of the boom 7. The cabin 8 has various operation units for controlling the operation of the crane device 3 (for example, various input means such as a main winch lever 109, a sub winch lever 110, a turning lever 112, a hoisting lever 113, an extendable lever 114, etc. See). An operator who has boarded the cabin 8 operates the crane device 3 by operating various operation units.
Further, the crane device 3 includes a main winch 9 and a sub winch 10.

  The tip portion of the boom 7 is mainly composed of a boom head and a plurality of sheaves, and the main wire 21 as the first wire rope is bridged from the base end portion to the tip portion of the boom 7 and is lowered from the tip portion. It is done. Further, the sub-wire 25 as the second wire rope is bridged from the base end portion of the boom 7 to the middle portion, and is unwound from the middle portion of the boom 7 when the boom 7 is extended. A main hook block 22 is hung on the main wire 21. A sub hook block 26 is fixed to the tip of the sub wire 25. The base ends of the main wire 21 and the sub wire 25 are connected to the main winch 9 and the sub winch 10, respectively. The crane apparatus 3 drives the main winch 9 and the sub winch 10 to wind and unwind the main wire 21 and the sub wire 25.

  In the above-described configuration, the crane device 3 is configured so that the main wire 21 and the main winch 9 and the sub winch 10 are engaged with the main hook block 22 and the sub hook block 26 in a state where the load B (see FIGS. 3 to 5) is locked. The baggage B is transported by winding and unwinding the sub-wire 25 and turning the boom 7 by the turning device.

  As shown in FIG. 2, the crane apparatus 3 includes a control unit 100 that controls the operation of the crane apparatus 3. The control unit 100 according to the present embodiment includes a storage unit mainly including a RAM and a ROM, and an arithmetic processing unit including a CPU that executes a program stored in the storage unit. The control unit 100 is electrically connected to output means such as the main winch 9, the sub winch 10, the hoisting cylinder 13, and the telescopic cylinder 14, and each output means is driven based on a signal transmitted from the control unit 100. . That is, the control unit 100 controls the winding and unwinding of the main wire 21 and the sub wire 25 by the main winch 9 and the sub winch 10 and the turning of the boom 7 by the turning device.

  As shown in FIG. 3, the control unit 100 is electrically connected to input means such as a main winch lever 109, a sub winch lever 110, a turning lever 112, a hoisting lever 113, an extendable lever 114, and the like. A signal is input to the control unit 100.

  In addition, the crane device 3 includes a tension detector 121 that is a tension measuring unit that measures the tension (the tensions T1 and T2 illustrated in FIGS. 3 to 5) for the main wire 21 and the subwire 25, and the respective hanging angles. An angle detector 122 that is a hanging angle measuring unit that measures the suspension length, and a length detector 123 that is a hanging length measuring unit that measures each hanging length. As the tension detector 121 in the present embodiment, a load cell provided at the tip of the boom 7 is used. Further, the angle detector 122 is configured by combining two load cells (for example, load cells for detecting respective tensions in the vertical direction and the horizontal direction) provided at the tip of the boom 7. Further, as the length detector 123, a rotation number measuring device for the main winch 9 and the sub winch 10 is used.

  Next, based on the tension measured by the tension detector 121, the suspension angle measured by the angle detector 122, and the suspension length measured by the length detector 123, using FIGS. 3 to 5. A method for lifting the load B from the ground GL by controlling the crane device 3 will be described. In this specification, “lifting the load B” means a state in which the load B is supported only by the main wire 21 and the sub-wire 25 (a state in which the load B is separated from the ground GL).

  3 to 5 schematically show a state in which the main wire 21 is wound from the tip of the boom 7 and the sub-wire 25 is wound from the middle to lift the load B. FIG. 3 is a schematic explanatory view at the time of lifting the luggage B when the boom 7 is not deflected.

  The operator turns the boom 7 so that the main wire 21 is wound down in the vertical direction as shown in FIG. 3 before the lifting of the luggage B is started. That is, when the main wire 21 starts to be wound in this state, the load B is lifted vertically upward as shown in FIG. Further, before starting the lifting of the load B, the control unit 100 starts to wind the main wire 21 by driving the main winch 9 as shown in step S01 in FIG.

  Next, the control unit 100 determines the tension T1 of the main wire 21 measured by the tension detector 121, the hanging angle of the main wire 21 measured by the angle detector 122, and the main wire 21 measured by the length detector 123. The horizontal component force T1x (see FIG. 4) of the tension in the main wire 21 is calculated from the hanging length of the main wire 21.

  Then, as shown in step S02 in FIG. 6, the control unit 100 determines whether or not the horizontal component force T1x of the tension in the main wire 21 is greater than 0 (whether or not the horizontal component force T1x is generated). When the boom 7 is not deflected, the load B is lifted vertically upward by the main wire 21 as indicated by an arrow F1 in FIG. 3, so that no horizontal component force T1x is generated.

  If the control unit 100 determines in step S02 that the horizontal component force T1x is not greater than 0 (the horizontal component force T1x is not generated), the control unit 100 proceeds to step S03 in FIG. In step S03, the control unit 100 sets the sub-wire 25 so that the sub-wire 25 has a minimum suspended length that does not generate tension as shown by a broken line arrow F2 in FIG. 3 (so that no slack or the like occurs in the sub-wire 25). Is carried out, and then the process returns to step S01. Thus, when the horizontal component T1x of the tension in the main wire 21 is zero, Step S01 to Step S03 are repeated. In other words, when there is no deflection of the boom 7 because the weight of the load B is small or the boom 7 is rigid, the load of the load B is lifted only by the main wire 21. Can start.

  On the other hand, when the boom 7 is deflected, the load B is lifted forward and upward by the main wire 21 as indicated by an arrow F1 in FIG. If the control unit 100 determines in step S02 that the horizontal component force T1x is greater than 0 (the horizontal component force T1x is generated), the control unit 100 proceeds to step S04 in FIG.

  The controller 100 starts the winding of the sub-wire 25 by driving the sub-winch 10 as shown in step S04 in FIG.

  Next, the control unit 100 determines the tension T2 of the subwire 25 measured by the tension detector 121, the suspension angle of the subwire 25 measured by the angle detector 122, and the suspension of the subwire 25 measured by the length detector 123. From the length, the horizontal component force T2x of the tension in the sub-wire 25 is calculated. As indicated by an arrow F2 in FIG. 5, the load B is lifted rearward and upward by the sub-wire 25, so that a horizontal component force T2x is generated.

  Then, as shown in step S05 in FIG. 6, the control unit 100 determines whether or not the horizontal component force T2x of the tension in the sub-wire 25 is equal to or greater than the horizontal component force T1x of the tension in the main wire 21.

  When the control unit 100 determines in step S05 in FIG. 6 that the horizontal component T2x is not equal to or greater than the horizontal component T1x (the horizontal component T2x is less than the horizontal component T1x), the control unit 100 returns to step S04. By driving the sub winch 10, the winding of the sub wire 25 is continued.

  When the control unit 100 determines in step S05 in FIG. 6 that the horizontal component force T2x is equal to or greater than the horizontal component force T1x, the control unit 100 proceeds to step S06, and the horizontal component force T2x of the tension in the sub-wire 25 is changed to the main wire 21. It is determined whether or not the tension in the horizontal direction is equal to the horizontal component force T1x. The term “equal” used in the present specification means “the force is the same so that the load B does not move in the horizontal direction”, and the two numerical values do not necessarily coincide with each other. .

  If the controller 100 determines in step S06 in FIG. 6 that the horizontal component T2x is not equal to the horizontal component T1x (the horizontal component T2x is greater than the horizontal component T1x), the control unit 100 returns to step S01. By driving the main winch 9, the winding of the main wire 21 is continued.

  If the control unit 100 determines in step S06 in FIG. 6 that the horizontal component T2x is equal to the horizontal component T1x (the horizontal component T2x is balanced with the horizontal component T1x), step S07 is performed. Then, by driving the main winch 9 and the sub winch 19, the main wire 21 and the sub wire 25 are wound at a constant speed, and the load B is lifted. That is, the control unit 100 starts lifting the load B in a state where the horizontal component force (T1x · T2x) of the tension in each of the main wire 21 and the sub-wire 25 becomes equal.

  According to the crane 1 according to the present embodiment, before starting lifting of the load B as described above, the horizontal component force (T1x · T2x) of the tension in each of the main wire 21 and the sub-wire 25 is equalized. The main winch 9 and the sub winch 19 are driven. As a result, even when the boom 7 is bent when the baggage B is lifted by the two wire ropes 21 and 25 wound down from the boom 7, and the boom 7 is bent, the baggage in the expansion and contraction direction of the boom 7 can be obtained. B swing (longitudinal swing) can be suppressed. Further, according to the present embodiment, since the ground cutting is performed only by the winding control of the two wire ropes 21 and 25, it is not necessary to perform the hoisting operation of the boom 7, and the lifting time of the load B can be shortened. it can.

1 Crane 7 Boom 9 Main winch 10 Sub winch 21 Main wire (first wire rope)
25 Subwire (second wire rope)
B luggage

Claims (2)

The boom,
A first wire rope that is bridged from the base end portion of the boom to the tip end portion and is wound down from the tip end portion;
A first winch for winding and unwinding the first wire rope;
A second wire rope spanned from the base end portion of the boom to the midway portion and wound down from the midway portion;
A second winch for winding and unwinding the second wire rope;
A tension measuring unit for measuring the tension of each of the first wire rope and the second wire rope;
A hanging angle measuring unit for measuring the hanging angle of each of the first wire rope and the second wire rope;
A suspended length measuring unit for measuring the suspended length of each of the first wire rope and the second wire rope;
A control unit for controlling the winding and unwinding of the first wire rope and the second wire rope by the first winch and the second winch,
A crane that lifts one load by the first wire rope and the second wire rope and allows the load to be transported,
Before the control unit starts lifting the luggage,
Based on the tension measured by the tension measurement unit, the suspension angle measured by the suspension angle measurement unit, and the suspension length measured by the suspension length measurement unit, the first wire Calculate the horizontal component of tension in each of the rope and the second wire rope,
The first wire rope by the first winch and the second winch, and the horizontal component of the tension in the first wire rope and the horizontal component of the tension in the second wire rope are equal. A crane that controls winding and unwinding of the second wire rope.   When the horizontal component force of the tension in the first wire rope is zero, the control unit uses the second winch so that the minimum suspension length in which the tension in the second wire rope is not generated is obtained. The crane according to claim 1, wherein the second wire rope is wound.

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