Crane and crane control method

Abstract

To provide a crane and a crane control method capable of fine-adjusting the position of a suspension tool.SOLUTION: A short-side rope group Rx includes a first rope Rx1 connected to a first tilting mechanism J1 through the other first upper sheave Sa1, which is paired with a first upper sheave Sa1, with installed in a trolley through a first lower sheave Sb1 installed in a suspension tool 3 through the first upper sheave Sa1 delivered from a drum 9 to be installed in the trolley, and a second rope Rx2 connected to a second tilting mechanism J2 through the other second upper sheave Sa2, which is paired with a second upper sheave Sa2, installed in the trolley through a second lower sheave Sb2 installed in the suspension tool 3 through a second upper sheave Sa2 delivered from the drum 9 to be installed in the trolley. The first rope Rx1 and the second rope Rx2 laid at tension between the trolley and the suspension tool 3 are tilted in a downward direction for approaching each other in the short-side direction x.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a crane having a hoisting attachment suspended from a trolley by a rope and a method for controlling the crane, and more particularly to a crane and a method for controlling the crane that enable fine adjustment of the position of the hoisting attachment. [Background technology]

[0002] Various cranes have been proposed that have a hoisting device suspended from a trolley by a rope (see, for example, Patent Document 1). The crane described in Patent Document 1 has a configuration in which the rope that is paid out from the drum is directly wound around a lower sheave that is installed on the hoisting device. The rope that is stretched between the drum and the lower sheave is parallel in the vertical direction.

[0003] When controlling the double-headed jack to adjust the position of the hoisting device, resistance is generated from the rope that is parallel to the vertical direction, making it difficult to make fine adjustments to the position of the hoisting device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2015-193462 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a crane and a method for controlling a crane that enable fine adjustment of the position of a hoisting tool. [Means for solving the problem]

[0006] A crane for achieving the above object includes a hoisting device formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view, a trolley arranged above the hoisting device, a drum installed on the trolley and around which a rope is wound, and a pair of short side direction rope groups arranged at an interval in the long side direction which is the extension direction of the long side, in which the short side direction rope group is unwound from the drum as the rope, passes through a first upper sheave installed on the trolley, passes through a first lower sheave installed on the hoisting device, and is installed on the trolley and is paired with the first upper sheave. and a second rope that is unwound from the drum, passes through a second upper sheave installed on the trolley, passes through a second lower sheave installed on the hoisting device, and is connected to the second tilting mechanism via another second upper sheave that is installed on the trolley and pairs with the second upper sheave, and is characterized in that the first rope and the second rope that are stretched between the trolley and the hoisting device are configured to incline in a direction that approaches each other downward in the short side direction, which is the extension direction of the short side.

[0007] A method for controlling a crane to achieve the above object is a method for controlling a crane including a hoisting device formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view, a trolley arranged above the hoisting device, a drum installed on the trolley and around which a rope is wound, a pair of short side direction rope groups arranged at intervals in the long side direction which is the extension direction of the long sides, and a pair of long side direction rope groups arranged at intervals in the short side direction which is the extension direction of the short sides, wherein the short side direction rope groups are a first rope that is unwound from the drum and installed on the trolley as the rope. a first rope that passes through an upper sheave, passes through a first lower sheave that is installed on the hoisting device, and is connected to a first tilting mechanism via another first upper sheave that is installed on the trolley and pairs with the first upper sheave; and a second rope that is unwound from the drum, passes through a second upper sheave that is installed on the trolley, passes through a second lower sheave that is installed on the hoisting device, and is connected to a second tilting mechanism via another second upper sheave that is installed on the trolley and pairs with the second upper sheave, and the first rope and the second rope are stretched between the trolley and the hoisting device. The long side direction rope group includes a third rope that is unwound from the drum, passes through a third upper sheave installed on the trolley, passes through a third lower sheave installed on the hoisting tool, is installed on the trolley, and is connected to a third tilting mechanism via another third upper sheave that is paired with the third upper sheave; and a fourth rope that is unwound from the drum, passes through a fourth upper sheave installed on the trolley, passes through a fourth lower sheave installed on the hoisting tool, and is installed on the trolley. and a fourth rope connected to a fourth tilting mechanism via another fourth upper sheave that is paired with the fourth upper sheave, wherein the third rope and the fourth rope stretched between the trolley and the hoisting device are configured to be inclined in a direction approaching each other downward in the long side direction, and a control mechanism controls the tilting mechanism to increase or decrease the tension of the rope connected to this tilting mechanism, thereby performing a lateral shift control that moves the hoisting device in the short side direction, a skew control that rotates the hoisting device around the up-and-down direction, and a traveling shift control that moves the hoisting device in the long side direction.The present invention is characterized by selectively performing trim control to tilt the hoisting tool around the short side direction. [Effects of the Invention]

[0008] According to the present invention, the rope extending from the trolley to the hoisting device is inclined relative to the vertical direction. This reduces the resistance generated by the rope when adjusting the position of the hoisting device, such as for skew control. This is advantageous for achieving fine adjustment of the position of the hoisting device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram illustrating an outline of a crane. [Figure 2] FIG. 2 is an explanatory diagram illustrating an outline of a rope stretched between a trolley and a hoisting tool. [Figure 3] FIG. 10 is an explanatory diagram illustrating an outline of a short side direction rope group. [Figure 4] FIG. 10 is an explanatory diagram illustrating a side view of a short side direction rope group. [Figure 5] 10A and 10B are explanatory diagrams illustrating modified examples of the tilt mechanism. [Figure 6] FIG. 10 is an explanatory diagram illustrating an outline of a long-side direction rope group. [Figure 7] FIG. 10 is an explanatory diagram illustrating a front view of a long-side direction rope group. [Figure 8] FIG. 10 is an explanatory diagram illustrating an example of a movement direction of a hoisting tool. DETAILED DESCRIPTION OF THE INVENTION

[0010] The crane and the method of controlling the crane will be described below based on the embodiment shown in the drawings. In the drawings, the short side direction, which is the direction in which the short side of the hoisting tool extends, is indicated by arrow x, the long side direction, which is the direction perpendicular to the short side direction x and is also the direction in which the long side of the hoisting tool extends, is indicated by arrow y, and the up and down direction is indicated by arrow z.

[0011] As shown in FIG. 1, the crane 1 is, for example, a quay crane arranged on a quay 2. The crane 1 is equipped with a hoisting device 3 that holds a container C, and a trolley 4 that is arranged above the hoisting device 3. The hoisting device 3 is suspended from the trolley 4 by a rope R. The crane 1 of this embodiment is equipped with an upper trolley 4a that is configured to be able to move laterally along an upper horizontal beam 5a, a lower trolley 4b that is fixed near a lower horizontal beam 5b, and a traverser 6 that is configured to be able to move laterally along the lower horizontal beam 5b.

[0012] The upper trolley 4a moves the container C between the container ship 7 and the traverser 6. The lower trolley 4b moves the container C between the chassis 8 that transports the container C and the traverser 6. The crane 1 is not limited to a quay crane, but may be any crane equipped with a hoisting device 3 and a trolley 4. The crane 1 may be configured as, for example, a gantry crane, an unloader, or an overhead crane. The hoisting device 3 is configured as a spreader that grips the container C and a bucket that loads and unloads bulk cargo such as coal.

[0013] As shown in Figure 2, the hoisting device 3 is suspended from a trolley 4 by multiple ropes R. The trolley 4 is not shown in Figure 2. The hoisting device 3 is formed in a substantially rectangular shape having a pair of long sides 3a and a pair of short sides 3b in a plan view. Multiple lower sheaves Sb are arranged on the hoisting device 3. Multiple upper sheaves Sa are arranged on the trolley 4.

[0014] A drum 9 on which multiple ropes R are wound is installed on the trolley 4. In this embodiment, two drums 9 are installed on the trolley 4. The number of drums 9 installed on the trolley 4 is not limited to two. The number of drums 9 may be one, or three or more. The sling 3 is suspended from the trolley 4 by the ropes R that are paid out from the drum 9.

[0015] The crane 1 is equipped with a pair of narrow side direction rope groups Rx arranged at a distance in the long side direction y. The two narrow side direction rope groups Rx are symmetrical about an imaginary plane that extends in the narrow side direction x and the up-down direction z and passes through the center of the long side 3a. For ease of explanation, part of the imaginary plane that forms the boundary between the two narrow side direction rope groups Rx is shown by a dashed line in Figure 2.

[0016] The crane 1 is equipped with a pair of long side direction rope groups Ry arranged at a distance in the short side direction x. The two long side direction rope groups Ry are symmetrical with respect to a virtual plane extending in the long side direction y and the up-down direction z, and passing through the center of the short side 3b, except for a small portion. For ease of explanation, part of the virtual plane that forms the boundary between the two long side direction rope groups Ry is shown by a dashed line in Figure 2.

[0017] As illustrated in Figures 3 and 4, each short side rope group Rx has a first rope Rx1 and a second rope Rx2 (hereinafter, sometimes collectively referred to as ropes R). For ease of explanation, the first rope Rx1 is shown by a solid line and the second rope Rx2 is shown by a dashed line in Figure 3. For ease of explanation, the long side rope group Ry is omitted in Figures 3 and 4.

[0018] As illustrated in Figure 3, the first rope Rx1 is unwound from the drum 9 and passes through a first upper sheave Sa1 installed on the trolley 4, a first lower sheave Sb1 installed on the hoisting device 3, and another first upper sheave Sa1 installed on the trolley 4 and paired with the first upper sheave Sa1, in that order. An end of the first rope Rx1 is connected to the first tilting mechanism J1. One end of the first rope Rx1 is fixed to the drum 9, and the other end is fixed to the first tilting mechanism J1. The direction of the first rope Rx1 may be changed as needed by another upper sheave Sa installed on the trolley 4 as needed.

[0019] A pair of first upper sheaves Sa1 are installed on the trolley 4. In this embodiment, the pair of first upper sheaves Sa1 are installed relative to a common central axis. It can also be said that the pair of first upper sheaves Sa1 are installed on the trolley 4 with their respective central axes positioned on the same straight line. The placement positions of the pair of first upper sheaves Sa1 are not limited to the above. The pair of first upper sheaves Sa1 only need to be placed in positions that are at least close to each other.

[0020] The second rope Rx2 is tensioned in the same manner as the first rope Rx1. The second rope Rx2 is unwound from the drum 9 and passes through a second upper sheave Sa2 installed on the trolley 4, a second lower sheave Sb2 installed on the hoisting device 3, and another second upper sheave Sa2 installed on the trolley 4 and paired with the second upper sheave Sa2, in that order. An end of the second rope Rx2 is connected to the second tilting mechanism J2.

[0021] The pair of second upper sheaves Sa2 installed on the trolley 4 are also arranged in the same manner as the first upper sheave Sa1. The pair of second upper sheaves Sa2 only need to be arranged at positions at least adjacent to each other.

[0022] 4, the pair of first upper sheaves Sa1 are installed close to each other on the trolley 4. Therefore, in the first rope Rx1 shown by the solid line, the portions (hereinafter sometimes referred to as inclined portions L1) that are respectively stretched from the first lower sheave Sb1 toward the pair of first upper sheaves Sa1 are approximately parallel to each other when viewed in a direction parallel to the long side direction y.

[0023] The pair of second upper sheaves Sa2 are also installed on the trolley 4 in a state where they are close to each other. Therefore, in the second rope Rx2 shown by the dashed line, the portions (hereinafter sometimes referred to as inclined portions L2) that are respectively stretched from the second lower sheave Sb2 toward the pair of second upper sheaves Sa2 are also approximately parallel to each other when viewed in a direction parallel to the long side direction y. It is desirable that the pair of inclined portions L1 and the pair of inclined portions L2 be stretched in a state where they are line-symmetrical with respect to the up-down direction z.

[0024] The inclined portion L extending from one upper sheave Sa to the lower sheave Sb and the inclined portion L extending from the other upper sheave Sa to the lower sheave Sb are tensioned at an angle relative to the vertical direction z. As a result, a force Fx is generated in the first rope Rx1 and the second rope Rx2 in the short side direction x according to the tension. The force Fx generated in the inclined portion L1 and the force Fx generated in the inclined portion L2 are generated toward the center of the hoist 3 in the short side direction x. This is advantageous for improving the vibration-damping effect of the hoist 3, as a force Fx that presses down on the hoist 3 is generated from both sides in the short side direction x. In this specification, the rope R tensioned between the trolley 4 and the hoist 3 refers to the portion of the rope R between the upper sheave Sa and the lower sheave Sb. This portion coincides with the inclined portion L.

[0025] The pair of inclined portions L1 is not limited to being substantially parallel to each other. It is sufficient that the pair of inclined portions L1 are configured to be inclined in at least the same direction with respect to the vertical direction z. The same applies to the pair of inclined portions L2. The inclined portions L1 and L2 are inclined in opposite directions with respect to the vertical direction z.

[0026] The first tilting mechanism J1 and the second tilting mechanism J2 (hereinafter sometimes collectively referred to as tilting mechanisms J) are configured, for example, by telescopic cylinders. The tilting mechanism J is not limited to the above, and may have a configuration that can control the increase or decrease of the tension of the connected rope R. The tilting mechanism J may also be configured, for example, by a link mechanism.

[0027] As shown in Fig. 5, the tilting mechanism J, which is configured as a link mechanism, may include, for example, a link unit 10 to which the rope R is connected, and a motor unit 11 that applies power to the link unit 10. For ease of explanation, Fig. 5 shows a plan view of the tilting mechanism J at the top and a side view of the tilting mechanism J at the bottom. Rotation of the motor unit 11 causes the link unit 10 to move back and forth along the short side direction x. This causes the tension in the rope R to increase or decrease.

[0028] As illustrated in Figure 4, the crane 1 is equipped with a control mechanism 12 installed on the trolley 4. The control mechanism 12 is configured to control the tilting mechanism J. Therefore, the control mechanism 12 can control the increase or decrease of the tension of the rope R via the tilting mechanism J. The control mechanism 12 is connected to the tilting mechanism J by a signal line. For the sake of explanation, the signal line connecting the control mechanism 12 and the tilting mechanisms J1-2 is shown by a dashed line in Figure 4. The signal line connected to the control mechanism 12 is not limited to being wired, but may also be configured wirelessly.

[0029] As illustrated in Figure 4, the distance W1 between the first upper sheave Sa1 and the second upper sheave Sa2 in the short side direction x is set larger than the distance W2 between the first lower sheave Sb1 and the second lower sheave Sb2 in the short side direction x. Therefore, the first rope Rx1 and the second rope Rx2 stretched between the trolley 4 and the hoisting device 3 are inclined in directions approaching each other as they go downward. The first rope Rx1 and the second rope Rx2 are inclined in directions approaching each other in the short side direction x. The inclined portion L1 of the first rope Rx1 and the inclined portion L2 of the second rope Rx2 are inclined in directions approaching each other as they go downward in the short side direction x.

[0030] The rope R (inclined portion L1-2) stretched between the trolley 4 and the hoist 3 is unwound from the upper sheave Sa rather than from the drum 9. By setting the distance W1 between the first upper sheave Sa1 and the second upper sheave Sa2 in the short side direction x relatively large, the inclination θx of the first rope Rx1 and the second rope Rx2 stretched between the trolley 4 and the hoist 3 relative to the vertical direction z can be increased. Here, the inclination θx indicates the inclination of the inclined portion L1 or the inclined portion L2 relative to the vertical direction z when viewed in a direction parallel to the long side direction y. The inclination θx of the rope R can be increased by stretching the rope R from the upper sheave Sa to the lower sheave Sb compared to when the rope R is unwound directly from the drum 9 to the lower sheave Sb. This increases the force Fx generated in the short side direction x, which is advantageous for improving the vibration-damping effect of the hoist 3.

[0031] The rope R stretched between the trolley 4 and the hoisting device 3 is inclined relative to the vertical direction z, making it possible to efficiently perform tilt control, which tilts the hoisting device 3 relative to a predetermined central axis, and shift control, which moves the hoisting device 3 horizontally, using the tilting mechanism J. In the short side direction rope group Rx, there is no portion of the rope R stretched parallel to the vertical direction z between the trolley 4 and the hoisting device 3, so the rope R generates almost no resistance to the movement of the hoisting device 3 during tilt control or shift control. This makes it possible to fine-tune the position of the hoisting device 3. This is particularly advantageous when automating the placement and lifting of containers C using the hoisting device 3.

[0032] When the pair of inclined portions L are approximately parallel to each other, the direction of the force generated from the pair of inclined portions L as the tension of the rope R increases or decreases is approximately the same. This makes it possible to perform tilt control and shift control more efficiently. Because the inclined portions L are tensioned between the lower sheave Sb and the pair of upper sheaves Sa, their position does not fluctuate in the long side direction y. This is advantageous for efficiently performing tilt control, etc. If the rope R were tensioned directly from the drum 9 to the lower sheave Sb, the position of the rope R unwound from the drum 9 would move in the long side direction y depending on the unwound length of the rope R. Because the direction of the force generated from the inclined portions L fluctuates, the efficiency of tilt control, etc. would decrease.

[0033] When a pair of upper sheaves Sa have central axes positioned on the same straight line, it is desirable to set the spacing between a pair of upper sheaves Sa around which a certain rope R is wound equal to the spacing between a pair of upper sheaves Sa around which another rope R is wound. Specifically, the spacing between a pair of first upper sheaves Sa1 and the spacing between a pair of second upper sheaves Sa2 are set equal. This configuration allows the values ​​of the force Fx generated at the inclined portion L1 and the force Fx generated at the inclined portion L2 to match with high precision. By having different magnitudes of the forces Fx in the opposing directions, movement of the hoisting device 3 in the short side direction x can be suppressed. The control mechanism 12 can efficiently perform tilt control and shift control.

[0034] Since the drum 9 is installed on the trolley 4, the overall length of the rope R can be made relatively short. This makes it easier to avoid the problem of the increase or decrease in tension of the rope R caused by the tilting mechanism J being absorbed by the elongation of the rope R.

[0035] It is desirable to arrange a pair of short side direction rope groups Rx on the lower trolley 4b of the crane 1 shown in Figure 1. This allows the position of the hoisting device 3 and container C to be aligned with high precision relative to the stopped chassis 8. This improves the efficiency of loading and unloading the container C onto the chassis 8. A pair of short side direction rope groups Rx may also be arranged on the upper trolley 4a of the crane 1.

[0036] As shown in Figures 6 and 7, each long side direction rope group Ry has a third rope Ry3 and a fourth rope Ry4 (hereinafter, sometimes collectively referred to as ropes R). In Figure 6, for the sake of explanation, one long side direction rope group Ry is shown by a solid line and the other long side direction rope group Ry is shown by a dashed line. Also, for the sake of explanation, in Figures 6 and 7, the short side direction rope group Rx is omitted.

[0037] The third rope Ry3 is unwound from the drum 9 and passes through a third upper sheave Sa3 installed on the trolley 4, a third lower sheave Sb3 installed on the hoisting device 3, and another third upper sheave Sa3 installed on the trolley 4 and paired with the third upper sheave Sa3, in that order. An end of the third rope Ry3 is connected to the third tilting mechanism J3. The direction of the third rope Ry3 may be changed as appropriate by another upper sheave Sa installed on the trolley 4 as appropriate.

[0038] A pair of third upper sheaves Sa3 are installed on the trolley 4. In this embodiment, the pair of third upper sheaves Sa3 are installed relative to a common central axis. It can also be said that the pair of third upper sheaves Sa3 are installed on the trolley 4 with their respective central axes positioned on the same straight line. The positioning of the pair of third upper sheaves Sa3 is not limited to the above. The pair of third upper sheaves Sa3 only need to be positioned in positions that are at least close to each other.

[0039] The fourth rope Ry4 is tensioned in the same manner as the third rope Ry3. The fourth rope Ry4 is unwound from the drum 9 and passes through a fourth upper sheave Sa4 installed on the trolley 4, a fourth lower sheave Sb4 installed on the hoisting device 3, and another fourth upper sheave Sa4 installed on the trolley 4 and paired with the fourth upper sheave Sa4, in that order. An end of the fourth rope Ry4 is connected to the fourth tilting mechanism J4.

[0040] The pair of fourth upper sheaves Sa4 installed on the trolley 4 are also arranged similarly to the third upper sheaves Sa3. The pair of fourth upper sheaves Sa4 only need to be arranged at positions at least adjacent to each other.

[0041] 6, one third tilting mechanism J3 is connected to a third rope Ry3 of one long side direction rope group Ry and another third rope Ry3 of the other long side direction rope group Ry. Similarly, one fourth tilting mechanism J4 is connected to two fourth ropes Ry4.

[0042] 7, the pair of third upper sheaves Sa3 are installed on the trolley 4 in a state where they are close to each other. Therefore, in the third rope Ry3, the portions (hereinafter sometimes referred to as inclined portions L3) that are respectively stretched from the third lower sheave Sb3 toward the pair of third upper sheaves Sa3 are approximately parallel to each other when viewed in a direction parallel to the short side direction x.

[0043] Furthermore, the pair of fourth upper sheaves Sa4 are installed on the trolley 4 in a state where they are close to each other. Therefore, in the fourth rope Ry4, the portions (hereinafter sometimes referred to as inclined portions L4) that are respectively stretched from the fourth lower sheave Sb4 toward the pair of fourth upper sheaves Sa4 are also approximately parallel to each other when viewed in a direction parallel to the short side direction x. It is desirable that the pair of inclined portions L3 and the pair of inclined portions L4 be stretched in a state where they are symmetrical with respect to the up-down direction z.

[0044] The inclined portion L extending from one upper sheave Sa to the lower sheave Sb, and the inclined portion L extending from the other upper sheave Sa to the lower sheave Sb, are tensioned so as to be inclined relative to the vertical direction z. As a result, a force Fy is generated in the long side direction y in response to the tension generated in the third rope Ry3 and the fourth rope Ry4. The force Fy generated in the inclined portion L3 and the force Fy generated in the inclined portion L4 are generated toward the center of the hoisting device 3 in the long side direction y. Because a force Fy is generated that presses down on the hoisting device 3 from both sides in the long side direction y, this is advantageous for improving the vibration-damping effect of the hoisting device 3.

[0045] The pair of inclined portions L3 is not limited to being substantially parallel to each other, as long as the pair of inclined portions L3 are inclined in at least the same direction with respect to the vertical direction z. The same applies to the pair of inclined portions L4.

[0046] As illustrated in Figure 7, the distance W3 between the third upper sheave Sa3 and the fourth upper sheave Sa4 is set larger than the distance W4 between the third lower sheave Sb3 and the fourth lower sheave Sb4. Therefore, the third rope Ry3 and the fourth rope Ry4 stretched between the trolley 4 and the hoisting device 3 are inclined in directions approaching each other as they go downward. The third rope Ry3 and the fourth rope Ry4 are inclined in directions approaching each other in the long side direction y. The inclined portion L3 of the third rope Ry3 and the inclined portion L4 of the fourth rope Ry4 are inclined in directions approaching each other as they go downward in the long side direction y.

[0047] As with the narrow side rope group Rx, in the wide side rope group Ry, the rope R (inclined portion L3-4) extending from the trolley 4 to the hoist 3 is unwound from the upper sheave Sa rather than from the drum 9. By setting the distance W3 between the third upper sheave Sa3 and the fourth upper sheave Sa4 in the wide side direction y relatively large, the inclination θy of the third rope Ry3 and the fourth rope Ry4 stretched between the trolley 4 and the hoist 3 relative to the vertical direction z can be increased. Here, the inclination θy indicates the inclination of the inclined portion L3 or the inclined portion L4 relative to the vertical direction z when viewed in a direction parallel to the narrow side direction x. Since the force Fy generated in the wide side direction y can be increased, this is advantageous for improving the vibration-damping effect of the hoist 3.

[0048] As with the short side direction rope group Rx, in the long side direction rope group Ry, the ropes R tensioned between the trolley 4 and the hoisting device 3 are inclined relative to the vertical direction z, allowing the tilting mechanism J to efficiently control the tilting and shifting of the hoisting device 3. In the long side direction rope group Ry, there is no portion of the rope tensioned between the trolley 4 and the hoisting device 3 in a state parallel to the vertical direction z, so there is almost no resistance to the movement of the hoisting device 3 during tilting and shifting control. This allows the crane 1 to fine-tune the position of the hoisting device 3.

[0049] Similarly to the narrow side direction rope group Rx, in the wide side direction rope group Ry, when a pair of upper sheaves Sa have central axes positioned on the same straight line, it is desirable to set the spacing between a pair of upper sheaves Sa around which a certain rope R is reeled equal to the spacing between a pair of upper sheaves Sa around which another rope R is reeled. Specifically, the spacing between a pair of third upper sheaves Sa3 and the spacing between a pair of fourth upper sheaves Sa4 are set equal. This configuration allows the values ​​of the force Fy generated at the inclined portion L3 and the force Fy generated at the inclined portion L4 to match with high precision. By making the magnitudes of the forces Fy in the opposing directions different, movement of the hoisting device 3 in the wide side direction y can be suppressed. The crane 1 can efficiently perform tilt control and shift control.

[0050] If the rope R (inclined portion L) extending from the trolley 4 to the hoisting device 3 in at least one of the short side direction rope group Rx and the long side direction rope group Ry of the crane 1 is inclined with respect to the up-down direction z, the resistance force generated by the rope R can be suppressed. This is advantageous for realizing fine adjustment of the position of the hoisting device 3. If the rope R between the trolley 4 and the hoisting device 3 in both the short side direction rope group Rx and the long side direction rope group Ry of the crane 1 is inclined with respect to the up-down direction z, the resistance force generated by the rope R can be further suppressed. In this case, there is no portion of the rope R stretched between the trolley 4 and the hoisting device 3 that is approximately parallel to the up-down direction z, and all portions are inclined with respect to the up-down direction z.

[0051] Next, we will explain the control method of the crane 1. The crane 1, which is equipped with the short side direction rope group Rx and the long side direction rope group Ry described above, can fine-tune the position of the hoisting tool 3. The control mechanism 12 controls the tilting mechanism J1-4, thereby adjusting the position of the hoisting tool 3.

[0052] As illustrated in Figure 8, the control mechanism 12 can selectively perform a traveling shift control P1 that moves the hoisting device 3 in the long side direction y, a lateral shift control P2 that moves it in the short side direction x, a skew control P3 that rotates the hoisting device 3 around the up-down direction z, and a trim control P4 that tilts the hoisting device 3 around the short side direction x.

[0053] When the tension in the two third ropes Ry3 illustrated in Fig. 6 is decreased and the tension in the two fourth ropes Ry4 is increased, the hoisting device 3 moves along the long side direction y to the lower right side in Fig. 6. Conversely, when the tension in the two third ropes Ry3 is increased and the tension in the two fourth ropes Ry4 is decreased, the hoisting device 3 moves along the long side direction y to the upper left side in Fig. 6. The control mechanism 12 controls the third tilting mechanism J3 and the fourth tilting mechanism J4 to perform traveling shift control P1 in which the hoisting device 3 moves horizontally along the long side direction y.

[0054] When the tension in the two first ropes Rx1 (solid lines) illustrated in Fig. 3 is decreased and the tension in the two second ropes Rx2 (dashed lines) is increased, the hoisting device 3 moves along the short side direction x to the upper right side of Fig. 3. Conversely, when the tension in the two first ropes Rx1 (solid lines) is increased and the tension in the two second ropes Rx2 (dashed lines) is decreased, the hoisting device 3 moves along the short side direction x to the lower left side of Fig. 3. The control mechanism 12 controls the first tilting mechanism J1 and the second tilting mechanism J2 to perform lateral shift control P2 in which the hoisting device 3 moves horizontally along the short side direction x.

[0055] When the tension of the first rope Rx1 of one short side direction rope group Rx located on the upper left side of Fig. 3 is decreased and the tension of the second rope Rx2 is increased, and when the tension of the first rope Rx1 of the other short side direction rope group Rx located on the lower right side of Fig. 3 is increased and the tension of the second rope Rx2 is decreased, the hoisting device 3 rotates clockwise around the vertical direction z. When the increase and decrease in tension are controlled to be the opposite of the above, the hoisting device 3 rotates counterclockwise around the vertical direction z. The control mechanism 12 controls the first tilting mechanism J1 and the second tilting mechanism J2 to perform skew control P3 in which the hoisting device 3 rotates around the vertical direction z.

[0056] The tension of the first rope Rx1 and the second rope Rx2 of one short side direction rope group Rx located on the upper left side of Figure 3 is increased, and the tension of the two third ropes Ry3 arranged near this short side direction rope group Rx is increased. The tension of the first rope Rx1 and the second rope Rx2 of the other short side direction rope group Rx located on the lower right side of Figure 3 is decreased, and the tension of the two fourth ropes Ry4 arranged near this short side direction rope group Rx is decreased. In Figure 3, the hoisting device 3 rises on the upper left side and descends on the lower right side around the short side direction x. If the tension increase / decrease is controlled to be reversed, the upper left side of the hoisting device 3 descends and the lower right side rises. By controlling the first to fourth tilting mechanisms J1-4, the control mechanism 12 can perform trim control P4, tilting the hoisting device 3 around the short side direction x.

[0057] The tilting mechanism J controls the tension of the ropes R, allowing the crane 1 to perform traveling shift control P1, traverse shift control P2, skew control P3, and trim control P4. When equipped with only the narrow side rope group Rx, the crane 1 can perform traveling shift control P2 and skew control P3. When equipped with only the long side rope group Ry, the crane 1 can perform traveling shift control P1.

[0058] The crane 1 may be equipped with two third tilting mechanisms J3 and two fourth tilting mechanisms J4. In this case, the two third ropes Ry3 illustrated in FIG. 6 are each connected to a different third tilting mechanism J3. The two fourth ropes Ry4 are each connected to a different fourth tilting mechanism J4. As illustrated in FIG. 8, the control mechanism 12 is able to perform list control P5, which tilts the hoisting device 3 about the long side direction y. If list control P5 is not required, it is advantageous to configure the crane 1 to have one third tilting mechanism J3 and one fourth tilting mechanism J4, as this reduces the manufacturing costs of the crane 1.

[0059] The tension of the third rope Ry3 and fourth rope Ry4 of one long side direction rope group Ry, shown by a solid line in the lower left of Figure 6, is reduced, and the tension of the two first ropes Rx1 arranged near this long side direction rope group Ry is reduced. The tension of the third rope Ry3 and fourth rope Ry4 of the other long side direction rope group Ry, shown by a dashed line in the upper right of Figure 6, is increased, and the tension of the two second ropes Rx2 arranged near this long side direction rope group Ry is increased. The hoisting device 3 rises on the upper right side and descends on the lower left side, centered around the long side direction y. When the tension increase / decrease is controlled in the opposite way to the above, the hoisting device 3 descends on the upper right side and ascends on the lower left side. The control mechanism 12 controls the tilting mechanism J1-4 to perform wrist control P5, tilting the hoisting device 3 about the long side direction y.

[0060] Furthermore, when skew control P3 is performed, by controlling the tension of the long side direction rope group Ry in addition to the short side direction rope group Rx, the angle at which the hoisting device 3 swings can be increased by skew control P3. For example, when the tension of the first rope Rx1 of one short side direction rope group Rx located on the upper left side of Fig. 3 is decreased and the tension of the second rope Rx2 is increased, the tension of the third rope Ry3 (solid line) stretched near the first rope Rx1 is decreased and the tension of the third rope Ry3 (dash-dotted line) stretched near the second rope Rx2 is increased. Furthermore, when the tension of the first rope Rx1 of the other short side direction rope group Rx located on the lower right side of Fig. 3 is increased and the tension of the second rope Rx2 is decreased, the tension of the fourth rope Ry4 (solid line) stretched near the first rope Rx1 is increased and the tension of the fourth rope Ry4 (dash-dotted line) stretched near the second rope Rx2 is decreased. In Figure 6, the hoisting tool 3 rotates clockwise around the vertical direction z. When the increase and decrease in tension are controlled to be opposite to that described above, the hoisting tool 3 rotates counterclockwise. By controlling the tilting mechanism J1-4, the control mechanism 12 can perform skew control P3 in which the hoisting tool 3 rotates around the vertical direction z.

[0061] When the hoisting device 3 is in a neutral state, it is desirable that the inclination θx of the first rope Rx1 and the second rope Rx2 and the inclination θy of the third rope Ry3 and the fourth rope Ry4 relative to the vertical direction z are approximately the same. Here, the neutral state of the hoisting device 3 refers to a state in which control by the tilting mechanism J is not being performed, a state in which the hoisting device 3 is not holding a container or other cargo, and a state in which the hoisting device 3 is hoisted up to its highest position. Furthermore, "approximately the same" refers to a state in which the inclination θx and the inclination θy are equal, as well as a state in which the inclination θy is within a range of ±30% of the inclination θx. Specifically, for example, when the inclination θx = 30°, this refers to a state in which 21°≦θy≦39°. It is desirable that the inclination θy be within a range of ±10% of the inclination θx, it is desirable that the inclination θy be within a range of ±3%, and it is even more desirable that the inclination θy be within a range of ±1%. The lower the height of the sling 3 in the vertical direction z, the smaller the values ​​of the inclinations θx and θy. Therefore, if the condition θx × 0.7≦θy≦θx × 1.3 is satisfied when the sling 3 is hoisted up to its highest position, the inclination θy will satisfy the condition of the above formula no matter where the sling 3 is in the vertical direction z.

[0062] By making the inclination θx and the inclination θy approximately equal, the force Fx generated on the inclined portion L1, the force Fx generated on the inclined portion L2, the force Fy generated on the inclined portion L3, and the force Fy generated on the inclined portion L4 can be made approximately equal. The inclination θx and the inclination θy are determined by the installation positions of the upper sheave Sa and the lower sheave Sb. Movement of the hoisting device 3 in the short side direction x and the long side direction y can be suppressed.

[0063] When a pair of upper sheaves Sa have central axes positioned on the same straight line, the spacing between the two paired upper sheaves Sa may all be set equal. Specifically, the spacing between the first upper sheaves Sa1, the spacing between the second upper sheaves Sa2, the spacing between the third upper sheaves Sa3, and the spacing between the fourth upper sheaves Sa4 are set equal. With this configuration, when ropes R of the same length are unwound or reeled in as the drum 9 rotates, the lengths of the ropes R between the trolley 4 and the hoisting device 3 change equally. The hoisting device 3 can move in the vertical direction z while maintaining a horizontal state. Unintentional tilting of the hoisting device 3 due to movement in the vertical direction z can be suppressed. The crane 1 can perform tilt control and shift control with high precision.

[0064] By adopting a configuration in which the spacing between the multiple upper sheaves Sa is equal and the inclinations θx and θy are substantially the same, the accuracy of tilt control and the like can be further improved. With this configuration, the crane 1 can move the hoisting device 3 in the vertical direction z while maintaining a horizontal position without adjusting the rotation amount between the multiple drums 9 or controlling the tilting mechanism J. Since tilt control and shift control using the tilting mechanism J are sufficient for the horizontal hoisting device 3, the hoisting device 3 can be precisely positioned at any position. Furthermore, since it is sufficient to control the horizontal hoisting device 3 toward a desired position, the amount of calculation required to control the tilting mechanism J can be reduced. Because the control mechanism 12 can control the tilting mechanism J based on relatively simple calculations, the crane 1 can precisely position the hoisting device 3 at any position. Since the number of drums 9 and tilting mechanisms J can be reduced, the manufacturing cost of the crane 1 can be reduced.

[0065] It is desirable to install the upper sheave Sa and the lower sheave Sb so that the distance between them is equal in the vertical direction z. Specifically, for example, in the vertical direction z, the distance between the upper sheave Sa1 and the lower sheave Sb1 corresponding to the inclined portion L1 is equal to the distance between the upper sheave Sa2 and the lower sheave Sb2 corresponding to the inclined portion L2. With this configuration, the lengths of the ropes from the corresponding upper sheave Sa to the lower sheave Sb, i.e., the lengths of the inclined portions L1-4, are precisely aligned, thereby improving the accuracy of tilt control, etc. Even if the rope R elongates, the amount of change due to the elongation of the inclined portions L1-4 can be made approximately the same, thereby improving the accuracy of tilt control, etc.

[0066] The configuration in which the spacing between a pair of upper sheaves Sa is equal, the configuration in which the inclination θx and the inclination θy are substantially the same, and the configuration in which the spacing between the upper sheave Sa and the lower sheave Sb in the vertical direction z is equal are not essential constituent elements of the present invention. For example, if the hoisting device 3 tilts as it moves downward, the control mechanism 12 can correct this tilt by adjusting the rotation amount of some of the multiple drums 9. Furthermore, the tilted hoisting device 3 can be placed in any position by performing tilt control or shift control using the tilting mechanism J. In particular, when the crane 1 is operated automatically, the crane 1 acquires the current position of the hoisting device 3 using a sensor installed on the hoisting device 3, etc. The control mechanism 12 controls the tilting mechanism J in a direction that reduces the difference between the current position and a desired position. [Explanation of symbols]

[0067] 1 crane 2. Quay 3 Hanging equipment 3a Long side 3b Short side 4 Trolley 4a Upper trolley 4b Lower trolley 5 horizontal beam 5a Upper horizontal beam 5b Lower horizontal beam 6 Traverser 7. Container ships 8. Chassis 9 Drums 10 Link section 11 Motor section 12 Control Mechanism x Short side direction y Long side direction z Vertical direction R rope Rx Short side direction rope group Rx1 First Rope Rx2 Second Rope Ry Longitudinal rope group Ry3 Third Rope Ry4 Fourth Rope C Container Sa, Sa1-4 upper sheave Sb, Sb1-4 lower sheave J, J1-4 Tilt mechanism L, L1-4 sloped part F, Fx, Fy force W1-4 interval P1 Driving shift control P2 Traverse shift control P3 Skew Control P4 Trim Control P5 List Control

Claims

1. A crane includes a hoisting device formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view, a trolley arranged above the hoisting device, a drum installed on the trolley and around which a rope is wound, and a pair of short side direction rope groups arranged at an interval in the long side direction, which is the extension direction of the long sides. The short side direction rope group The rope is a first rope that is unwound from the drum, passes through a first upper sheave installed on the trolley, passes through a first lower sheave installed on the hoisting tool, and is connected to a first tilting mechanism via another first upper sheave that is installed on the trolley and pairs with the first upper sheave; a second rope that is unwound from the drum, passes through a second upper sheave installed on the trolley, passes through a second lower sheave installed on the hoisting device, passes through another second upper sheave that is installed on the trolley and pairs with the second upper sheave, and is connected to a second tilting mechanism, A crane characterized in that the first rope and the second rope stretched between the trolley and the hoisting device are configured to incline in a direction in which they approach each other downward in the short side direction, which is the extension direction of the short side.

2. A pair of long-side direction rope groups are provided, the long-side direction rope groups being spaced apart in the short-side direction, The long side direction rope group the rope is a third rope that is unwound from the drum, passes through a third upper sheave installed on the trolley, passes through a third lower sheave installed on the hoisting tool, passes through another third upper sheave that is installed on the trolley and pairs with the third upper sheave, and is connected to a third tilting mechanism; a fourth rope that is unwound from the drum, passes through a fourth upper sheave installed on the trolley, passes through a fourth lower sheave installed on the hoisting tool, passes through another fourth upper sheave that is installed on the trolley and pairs with the fourth upper sheave, and is connected to a fourth tilting mechanism, 2. A crane as described in claim 1, wherein the third rope and the fourth rope stretched between the trolley and the lifting device are configured to be inclined downward in the long side direction so as to approach each other.

3. 3. The crane according to claim 1, wherein two portions of the rope stretched from the lower sheave to the pair of upper sheaves are substantially parallel to each other.

4. 3. The crane according to claim 1, wherein the pair of upper sheaves around which the same rope is wound have central axes positioned on the same straight line.

5. a control mechanism for controlling the tilt mechanism to increase or decrease the tension of the rope connected to the tilt mechanism, 3. The crane according to claim 1, wherein the control mechanism performs skew control to rotate the hoisting device about the vertical direction by decreasing the tension of the first rope of one of the short side direction rope groups and increasing the tension of the second rope, and increasing the tension of the first rope of the other short side direction rope group and decreasing the tension of the second rope.

6. a control mechanism for controlling the tilt mechanism to increase or decrease the tension of the rope connected to the tilt mechanism, The control mechanism increases the tension of the first rope and the second rope of one of the short side direction rope groups and increases the tension of the third rope or the fourth rope arranged near one of the short side direction rope groups, 3. The crane according to claim 2, wherein trim control is performed to tilt the hoisting device around the short side direction by reducing the tension of the first rope and the second rope of the other short side direction rope group and reducing the tension of the fourth rope or the third rope arranged in the vicinity of the other short side direction rope group.

7. A method for controlling a crane including a hoisting device formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view, a trolley arranged above the hoisting device, a drum installed on the trolley and around which a rope is wound, a pair of short side direction rope groups arranged at intervals in the long side direction which is the extension direction of the long sides, and a pair of long side direction rope groups arranged at intervals in the short side direction which is the extension direction of the short sides, The short side direction rope group The rope is a first rope that is unwound from the drum, passes through a first upper sheave installed on the trolley, passes through a first lower sheave installed on the hoisting tool, and is connected to a first tilting mechanism via another first upper sheave that is installed on the trolley and pairs with the first upper sheave; a second rope that is unwound from the drum, passes through a second upper sheave installed on the trolley, passes through a second lower sheave installed on the hoisting device, passes through another second upper sheave that is installed on the trolley and pairs with the second upper sheave, and is connected to a second tilting mechanism, The first rope and the second rope stretched between the trolley and the hoisting tool are configured to be inclined downward in the short side direction so as to approach each other, The long side direction rope group the rope is a third rope that is unwound from the drum, passes through a third upper sheave installed on the trolley, passes through a third lower sheave installed on the hoisting tool, passes through another third upper sheave that is installed on the trolley and pairs with the third upper sheave, and is connected to a third tilting mechanism; a fourth rope that is unwound from the drum, passes through a fourth upper sheave installed on the trolley, passes through a fourth lower sheave installed on the hoisting tool, passes through another fourth upper sheave that is installed on the trolley and pairs with the fourth upper sheave, and is connected to a fourth tilting mechanism, The third rope and the fourth rope stretched between the trolley and the hoisting tool are configured to be inclined downward in the long side direction so as to approach each other, A crane control method, characterized in that a control mechanism controls the tilting mechanism to increase or decrease the tension of the rope connected to the tilting mechanism, thereby selectively performing lateral shift control to move the hoisting device in the short side direction, skew control to rotate the hoisting device around the up-and-down direction, traveling shift control to move the hoisting device in the long side direction, and trim control to tilt the hoisting device around the short side direction.

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