JP2022089036A - Suspended load turning apparatus - Google Patents

Abstract

To provide a suspended load turning apparatus capable of reliably limiting turning speed of suspended load even when disturbance such as wind occurs.SOLUTION: There is provided a suspended load turning apparatus 10 comprising a flywheel 11, a flywheel rotating electric motor 12 for driving the flywheel 11, a gimbal 13 for pivotally supporting the flywheel 11, and a gimbal inclining electric motor 14 for driving the gimbal 13, the apparatus causing suspended load 50 to turn by a gyroidal effect generated when the gimbal 13 is inclined while rotating the flywheel 11. The apparatus is provided with turning speed controlling means 15 for suppressing increase in the turning speed of the suspended load 50 by, when an inclination torque T of the gimbal inclining electric motor 14 exceeds a limiting value Tr, holding input current to the gimbal inclining electric motor 14 with the value at that time, and suspending the inclination by the gimbal inclining electric motor 14.SELECTED DRAWING: Figure 1

Description

The present invention relates to a suspended load swivel device for swiveling a suspended load such as a crane.

In cargo handling work using a crane, the suspended load is swiveled (horizontally swiveled) until it is in a predetermined direction and then unloaded at a target location. The turning of the suspended load is usually performed by an assistant standing nearby intervening (pulling or pushing the suspended load). However, when the suspended load is large or heavy, a plurality of assistants must work while communicating with each other, which causes a problem that the work efficiency is significantly lowered. In addition, if a worker is involved near the suspended load, the suspended load during turning may hit the worker and cause an accident such as the worker tipping over.

In view of such an actual situation, a device (suspended load swivel device) for mechanically swiveling a suspended load without human power has been developed, and the device is used in cargo handling work. As the suspended load swivel device, as shown in FIG. 1 of Patent Document 1, a device incorporating a gyro device (see reference numeral 10 in the same figure) is known. As shown in FIG. 2 of Patent Document 1, the gyro device is called a disk-shaped member called a "flywheel" (see reference numeral 10a in the figure) and a "gimbal" that pivotally supports the flywheel. It includes a member (see reference numeral 11 in the figure). This type of suspended load swivel device is interposed between the hook of the crane and the suspended load, and swivels the suspended load by the gyro effect caused by tilting (tilting) the gimbal while rotating the flywheel at high speed.

However, in the above-mentioned suspended load turning device, the gyro effect is continuously exerted from the flywheel to the gimbal while the gimbal is continuously tilted in one direction, and the turning speed of the suspended load continues to increase. Therefore, when the suspended load is a light load, the turning speed of the suspended load becomes too fast, which may lead to danger. In this regard, so far, a suspended load swivel device has been proposed in which the swiveling speed of the suspended load is feedback-controlled. For example, in paragraphs 0022 to 0032 of Patent Document 2 and FIG. 1, in a suspended load attitude control device (suspended load swivel device) that swivels a suspended load by utilizing the gyro effect, the suspended load angular velocity _φ'M (suspended load). It is described that the turning speed) is read by the gyro sensor 101 and controlled by the torque controller 206 so that the deviation between the angular velocity command value φ'and the suspended load angular velocity _φ'M becomes zero.

Japanese Unexamined Patent Publication No. 63-074891 Japanese Unexamined Patent Publication No. 2014-133600

However, in the type of suspended load swivel device that feedback-controls the swiveling speed of the suspended load, the correction process of the swiveling speed of the suspended load is followed up, so if a disturbance such as wind occurs, the correction process catches up. Until then, the suspended load may continue to rotate at a turning speed that exceeds the limit value. Further, it is necessary not only to provide a sensor (gyro sensor or the like) for detecting the turning speed of the suspended load, but also to perform complicated control such as requiring various calculations.

The present invention has been made to solve the above problems, and provides a suspended load turning device capable of reliably limiting the turning speed of a suspended load even when a disturbance such as wind occurs. Is what you do. It is also an object of the present invention to limit the turning speed of the suspended load by a simple method that does not separately use a sensor for detecting the turning speed of the suspended load.

The above issues are
With a flywheel,
A flywheel rotation motor that drives the flywheel to rotate,
The gimbal that supports the flywheel and
Equipped with a gimbal tilting motor that tilts and drives the gimbal,
It is a suspended load swivel device that swivels the suspended load by the gyro effect that occurs when the gimbal is tilted while rotating the flywheel.
When the tilt torque T of the gimbal tilting motor exceeds the limit value _Tr , the input current to the gimbal tilting motor is held at that value, and the tilting by the gimbal tilting motor is stopped to suspend the gimbal. It is solved by providing a suspension swivel device characterized by providing a swivel speed limiting means for limiting the swivel speed of the load (the angular velocity of the swivel of the suspended load; the same shall apply hereinafter).

As already mentioned, in the suspended load swivel device using the gyro effect, the swivel speed of the suspended load continues to increase due to the gyro effect applied from the flywheel to the gimbal while the gimbal continues to tilt in one direction. .. Therefore, when the suspended load starts to turn, a gyro effect is generated by the turning of the suspended load, and the output shaft of the gimbal tilting motor is in the direction opposite to the direction in which the output shaft is rotated (tilted). Torque will be applied. In the following, this torque in the opposite direction is referred to as "torque generated by turning the suspended load", and may be expressed as "torque T'" using the symbol "T'". Further, the torque output to the output shaft by the gimbal tilting motor for tilting the gimbal is called "tilt torque", and may be expressed as "tilt torque T" using the symbol "T".

The torque T'generated by the turning of the suspended load increases as the turning speed of the suspended load increases. The torque T'is a resistance force (resistance torque) when viewed from the tilt torque T of the gimbal tilting motor. Therefore, as the turning speed of the suspended load increases, a large resistance torque (torque T') is applied to the output shaft of the gimbal tilting motor, and the tilt torque T of the gimbal tilting motor increases. .. On the contrary, as the turning speed of the suspended load becomes slower, the resistance torque (torque T') applied to the gimbal tilting motor becomes smaller, and the tilting torque T of the gimbal tilting motor becomes smaller. In this way, the turning speed of the suspended load is directly reflected in the tilting torque T of the cymbal tilting motor.

In this respect, the suspended load turning device of the present invention is a gimbal tilting motor when the tilt torque T of the gimbal tilting motor exceeds the limit value _Tr (when the swing speed of the suspended load is likely to exceed the upper limit). By stopping the tilting due to the above, the turning speed of the suspended load does not increase more than that (the turning speed is limited). By limiting the turning speed of the suspended load based on the tilt torque T that directly reflects the turning speed of the suspended load, the turning speed of the suspended load is the upper limit even when disturbance such as wind occurs. When it is likely to exceed the above, the turning speed of the suspended load can be quickly and surely limited. In addition, it is not necessary to perform complicated calculations, and the turning speed of the suspended load can be limited by a simple method.

In the suspended load turning device of the present invention, the above-mentioned series of operations (operation of limiting the turning speed of the suspended load when the tilt torque T exceeds the limit value Tr) is executed by the turning speed limiting means. As the turning speed limiting means, a current limiting type torque limiter can be mentioned. An inverter device that normally controls the frequency of the AC current input to the gimbal tilting motor is interposed between the gimbal tilting motor (AC motor) and the power supply. This can be achieved by controlling with a device. Therefore, in the suspended load turning device of the present invention, it is not necessary to separately provide a sensor (gyro sensor or the like) for detecting the turning speed of the suspended load. Therefore, the configuration of the suspended load swivel device can be simplified.

Preferably, a suspended load swivel device provided with a limit value adjusting means for adjusting the limit value _Tr is provided.

Preferably, when the tilt torque T of the _gimbal tilting motor becomes less than the limit value Tr, the limitation of the swing speed of the suspended load by the swing speed limiting means is released, the input current of the gimbal tilting motor increases, and the gimbal A suspended load swivel device is provided in which the tilting of the tilting motor is restarted.

As described above, according to the present invention, it is possible to provide a suspended load turning device capable of reliably limiting the turning speed of a suspended load even when a disturbance such as wind occurs. Further, it is possible to limit the turning speed of the suspended load by a simple method that does not separately use a sensor for detecting the turning speed of the suspended load.

It is a perspective view which showed the state that the suspended load of a crane is swiveled by using the suspended load swivel device. It is a flow chart which showed an example of the turning operation of the suspended load by the suspended load turning device. It is a graph which showed the relationship between the energization time to the gimbal tilting motor and the turning speed of a suspended load when the limit value _Tr is changed in the suspended load turning device.

A preferred embodiment of the suspended load swivel device will be described more specifically with reference to the drawings. FIG. 1 is a perspective view showing a state in which the suspended load 50 of a crane is swiveled by using the suspended load swivel device 10. The circled enlarged portion in FIG. 1 is drawn in a state where the internal structure of the suspended load swivel device 10 is seen through.

As shown in FIG. 1, the suspended load swivel device 10 swivels a suspended load 50 suspended from a hook 60 or the like of a crane in the direction of arrow A1 _{about a} vertical axis L1. The suspended load swivel device 10 is provided at a place where the swivel force can be transmitted to the suspended load ₅₀ when it swivels around the vertical axis L1. In the example shown in FIG. 1, the suspended load swivel device 10 is interposed between the suspended load 50 and the hook 60 of the crane, and the suspended load swivel device 10 is attached above the suspended load 50. Even if it is attached to the lower side of the suspended load 50, the suspended load 50 can be swiveled.

The suspended load swivel device 10 houses the flywheel 11, the flywheel rotation motor 12, the gimbal 13, the gimbal tilting motor 14, and the swivel speed limiting means 15 in the housing 16. _The flywheel 11 has a disk shape, and its central portion is pivotally supported by the gimbal 13 in a state where it can rotate in the direction of the arrow _A2 about the axis L2. The flywheel rotation motor 12 rotationally drives the flywheel ₁₁ around the axis L2. The gimbal 13 has a frame shape surrounding the flywheel 11, and both ends thereof are pivotally supported in a state in which the gimbal ₁₃ can be _tilted in the direction of the arrow A3 with the axis L3 as the center. The axis L3, which is the center of tilt of the gimbal 13, and the axis L2 _, which is the center of rotation of the flywheel 11, are non _- parallel (crossed) to each other and are usually orthogonal to each other. The gimbal tilting motor 14 tilts and drives the gimbal ₁₃ around the axis L3. The turning speed limiting means 15 limits the turning speed of the suspended load 50 (the angular velocity of the turning of the suspended load 50).

In the suspended load swivel device 10 of the present embodiment, both the flywheel rotation electric motor 12 and the gimbal tilting electric motor 14 are electric motors. Of these, an inverter device (not shown) that controls the frequency of the AC current input to the gimbal tilting motor 14 is connected to the electric motor (AC motor) that constitutes the gimbal tilting motor 14, and this inverter device is connected. , A current-limited torque limiter is provided. This torque limiter functions as a turning speed limiting means 15 as described later. In a non-operating state in which no current is input to any of the electric motors (flywheel rotation motor 12 and gimbal tilting motor 14), the flywheel ₁₁ can freely rotate around the axis L2. Yes, the gimbal ₁₃ is in a state where it can freely tilt around the axis L3. In this non-operating state, the flywheel 11 and the gimbal 13 are balanced so that the flywheel 11 stands in the vertical direction (the axis L ₂ which is the center of rotation of the flywheel 11 lies horizontally).

When the flywheel rotation motor 12 is driven (starting the input of current to the flywheel rotation motor 12) from the above non-operating state, the flywheel 11 rotates around the axis L ₂ (rotates in the direction of arrow A ₂ ). )Begin to. Further, when the gimbal tilting motor 14 is driven (the input of the current to the gimbal tilting motor 14 is started), the gimbal ₁₃ starts tilting around the axis L3 ₍ tilting in the direction of the arrow A3). In this way, if the gimbal 13 is tilted while the flywheel 11 is rotating, the gyro effect is exerted from the flywheel 11 to the gimbal 13, and the housing 16 of the suspended load swivel device 10 has a gyro effect. A gyro moment around the vertical axis L ₁ is generated. Due to this gyro moment, the suspended load turning device ₁₀ turns around the vertical axis L ₁ (turns in the direction of arrow A1). Since the suspended load 50 is suspended below the suspended load swivel device 10, when the suspended load swivel device 10 swivels around the vertical axis L ₁ , the suspended load 50 also swivels around the vertical axis L ₁ (arrow A ₃ ). Turn in the direction of).

The direction in which the suspended load 50 turns can be reversed by reversing the direction in which the flywheel 11 is rotated or the direction in which the gimbal 13 is tilted. When the suspended load 50 is swiveled to a desired direction, the suspended load swivel device 10 stops the swivel and stops the swivel of the suspended load 50. The suspended load swivel device 10 of this embodiment can be operated by the remote controller 17.

As described above, the suspended load swivel device 10 swivels the suspended load 50 by the gyro effect generated when the gimbal 13 is tilted while rotating the flywheel 11. However, while the gimbal 13 continues to be tilted, the gyro effect continues to be exerted from the flywheel 11 to the gimbal 13, and the turning speed of the suspended load 50 continues to increase. Therefore, if the turning speed of the suspended load 50 is not limited, the turning speed of the suspended load 50 may become too high, which may lead to danger.

In this respect, in the suspended load swivel device 10, the swivel speed limiting means 15 (torque limiter) is used to limit the increase in the swivel speed of the suspended load 50. In the turning speed limiting means 15 (torque limiter), the tilting torque T (torque in which the gimbal tilting motor 14 tilts the gimbal 13 around the axis L ₃ ) of the gimbal tilting motor 14 is a predetermined limit value ( _Tr ). If it exceeds), the input current to the gimbal tilting motor 14 is held at the value at that time, and the tilting by the gimbal tilting motor is stopped.

That is, when the suspended load 50 is swiveling, the output shaft of the gimbal tilting motor 14 is rotated (tilted) in the direction (tilt torque) due to the gyro effect due to the swivel of the suspended load 50. Since the torque T'opposite to the direction of T) is applied, the tilt torque T of the gimbal tilting motor 14 increases. That is, the turning speed of the suspended load 50 is directly reflected in the tilting torque T of the cymbal tilting motor 14. Therefore, the tilt torque T of the gimbal tilting motor 14 is an index of the turning speed of the suspended load 50. Therefore, by limiting the cymbal tilting motor 14, it is possible to limit the increase in the turning speed of the suspended load 50.

FIG. 2 shows an example of a flow chart of the swivel operation of the suspended load 50 by the suspended load swivel device 10. It is assumed that the rotation of the flywheel 11 has already started at a stage prior to step S1 in FIG. As shown in FIG. 2, when the turning operation of the suspended load 50 is started (step S1), the tilting of the gimbal 13 is started (step S2). Specifically, the current input to the gimbal tilting motor 14 is started and the current is increased. Then, the gimbal 13 gradually starts to tilt to one side from the initial position (standing in the vertical direction), and the suspended load 50 is indicated by arrow A1 (FIG. ₁ ) due to the gyro effect caused by the rotation of the flywheel 11. Start turning in the direction. As the tilt angle of the gimbal 13 increases, the turning speed of the suspended load 50 (angular velocity of turning of the suspended load 50) is gradually accelerated.

In this way, when the gimbal 13 is tilted and the suspended load 50 is swiveling, when the swivel stop operation is performed by the remote controller 17 or the like (“YES” in step S3), the gimbal tilting motor The current input to 14 is stopped (step S7). As a result, the gimbal 13 is released from the restraint by the gimbal tilting motor 14 and can be freely tilted in the direction of arrow A3 ₍ FIG. 1). Therefore, the tilting of the gimbal 13 to one side is stopped, and then the gimbal 13 begins to tilt in the opposite direction (the side that returns to the initial position) due to the gyro effect of the suspended load 50 that swivels due to inertia. The turning of the suspended load 50 stops. As a result, the turning operation of the suspended load 50 is completed (step S8).

On the other hand, when the gimbal 13 continues to tilt (“NO” in step S3) without the turning stop operation, the turning speed of the suspended load 50 continues to increase, and the gimbal tilting motor 14 continues to tilt. The rolling torque T continues to increase until the limit value _Tr is reached (“NO” in step S4). On the other hand, when the tilt torque T of the gimbal tilting motor 14 exceeds the limit value _Tr (“YES” in step S4), the tilting of the gimbal 13 is stopped (step S5). Specifically, the input current to the gimbal tilting motor 14 is held at the value at that time (the energized state at that time is held). When the tilting torque T of the gimbal tilting motor 14 is balanced with the torque T'(FIG. 1) due to the gyro effect generated by the turning of the suspended load 50, the tilting of the gimbal 13 is stopped.

When the tilting of the gimbal 13 is stopped, the gyro effect due to the rotation of the flywheel 11 is not exerted on the suspended load 50, so that the increase in the turning speed of the suspended load 50 stops. Even if the tilting of the gimbal 13 is stopped, the suspended load 50 continues to turn due to inertia, but the turning speed gradually decreases due to resistance such as friction. While the tilt torque T of the gimbal tilting motor 14 is larger than the limit value _Tr , the gimbal 13 tilting remains stopped (“NO” in step S6), but the gimbal tilting motor When the tilt torque T of 14 becomes smaller than the limit value _Tr , the tilt of the gimbal 13 is started again (“YES” in step S6).

As described above, by limiting the tilting torque T of the gimbal tilting motor 14 and limiting the turning speed of the suspended load 50, the turning speed of the suspended load 50 can be quickly limited when necessary. can. Therefore, even when a disturbance such as wind occurs, it is possible to surely suppress an increase in the turning speed so that the turning speed does not exceed the upper limit. Further, it is not necessary to perform complicated calculations, and the turning speed of the suspended load 50 can be limited by a simple method. Further, it is not necessary to separately provide a sensor (gyro sensor or the like) for detecting the turning speed of the suspended load 50. Therefore, the configuration of the suspended load swivel device 10 can be simplified.

Furthermore, as shown in step S6 of FIG. 2, when the tilt torque T of the gimbal tilting motor 14 becomes smaller than the limit value _Tr , the tilting of the gimbal tilting motor 14 is restarted. By doing so, it is possible to continue turning the suspended load 50 at the turning speed immediately before the upper limit is exceeded, and it is also possible to improve the efficiency of cargo handling work, such as turning the suspended load 50 in a short time until it reaches the desired direction. Is.

By the way, in the suspended load swivel device 10, as can be seen from the execution of the process of step S4 in FIG. 2, the maximum value (maximum angular velocity) of the swivel speed of the suspended load 50 changes depending on the limit value _Tr . FIG. 3 is a graph showing the relationship between the energization time of the gimbal tilting motor 14 and the turning speed of the suspended load 50 when the limit value _Tr is changed in the suspended load turning device 10. In the graph, the curve A shows the limit value _Tr set to 100% of the rated torque of the gimbal tilting motor 14, and the curve B shows the limit value _Tr set to 70 of the rated torque of the gimbal tilting motor 14. When the value is set to%, the curve C shows the limit value _Tr set to a value of 50% of the rated torque of the gimbal tilting motor 14, and the curve D shows the limit value _Tr set to the gimbal tilting motor. It is shown when it is set to the value of 30% of the rated torque of 14. Looking at FIG. 3, when the limit value _Tr is set to a high value, the maximum value (maximum angular velocity) of the turning speed of the suspended load 50 becomes high, and conversely, when the limit value _Tr is set to a low value, the suspended load is suspended. The maximum value (maximum angular velocity) of the turning speed of 50 is high. The graph in FIG. 3 was obtained by numerical calculation, but it has been confirmed that a result close to this can be obtained even in actual measurement.

In view of such characteristics, it is preferable that the suspended load turning device 10 is provided with a limit value adjusting means (not shown) for adjusting the limit value _Tr that limits the turning speed of the suspended load 50. This makes it possible to adjust the maximum value (maximum angular velocity) of the turning speed of the suspended load 50. Further, the maximum value (maximum angular velocity) of the turning speed of the suspended load 50 changes depending on the load of the suspended load (moment of inertia of turning), but when the suspended load 50 is a light load, the limit value _Tr. Is set low, and if the suspended load 50 is a heavy load, the limit value _Tr may be adjusted according to the load of the suspended load 50, such as setting the limit value _Tr to a high value. It will be possible.

In other words, the limit value _Tr may not be changed from one predetermined value, but the suspended load 50 is a light load with a small moment of inertia in the turning direction to a heavy load with a large load. Up to, various things are assumed. That is, since the turning speed of a lightly-loaded suspended load tends to be faster than that of a heavy-loaded suspended load, if the limit value _Tr is set assuming a heavy-loaded suspended load, the suspended load 50 is lightly loaded. When switching to a small one, the peripheral speed (turning speed) of the suspended load 50 may become too slow. Therefore, by providing the limit value adjusting means 15 (torque limiter) for adjusting the limit value _Tr , the turning speed of the suspended load 50 can be increased within a range where the critical speed is not reached.

In the above-mentioned limit value adjusting means, the limit value adjusting means may adjust the limit value _Tr step by step (a control value _Tr is selected from a plurality of predetermined values). However, the limit value _Tr may be continuously adjusted. Examples of the operation portion in the limit value adjusting means include buttons, switches, dials, levers, touch panels, and the like. These operating portions can also be provided in the remote controller 17 (FIG. 1). This allows the worker 70 to adjust the turning speed of the suspended load 50 at hand.

10 Suspended load swivel device 11 Flywheel 12 Flywheel rotation motor 13 Gimbal 14 Gimbal tilting motor 15 Swing speed limiting means 16 Housing 17 Remote controller 50 Suspended load 60 Hook 70 Worker A ₁ Suspended load turning direction A ₂ Fly Wheel rotation direction A ₃ Gimbal tilt direction L ₁ Vertical axis that is the turning center of the suspended load L ₂ Axis line that is the rotation center of the flywheel L ₃ Axis line that is the tilt center of the gimbal

Claims (3)

With a flywheel,
A flywheel rotation motor that drives the flywheel to rotate,
The gimbal that supports the flywheel and
Equipped with a gimbal tilting motor that tilts and drives the gimbal,
It is a suspended load swivel device that swivels the suspended load by the gyro effect that occurs when the gimbal is tilted while rotating the flywheel.
When the tilt torque T of the gimbal tilting motor exceeds the limit value _Tr , the input current to the gimbal tilting motor is held at that value, and the tilting by the gimbal tilting motor is stopped to suspend the gimbal. A suspended load swivel device provided with a swivel speed limiting means for limiting the swivel speed of a load.
The suspended load swivel device according to claim 1, further comprising a limit value adjusting means for adjusting the limit value _Tr .
When the tilt torque T of the _gimbal tilting motor becomes less than the limit value Tr, the limitation of the turning speed of the suspended load by the turning speed limiting means is released, the input current of the gimbal tilting motor increases, and the gimbal tilting motor The suspended load swivel device according to claim 1 or 2, wherein the tilting of the head is resumed.

Images