JP5640358B2 - Overhead traveling crane - Google Patents

Description

  The present invention relates to a crane apparatus. More specifically, it relates to an overhead crane.

  There is an overhead crane such as a ladle crane as a large-sized moving machine used in the steel industry. A ladle crane is used as a crane for transporting cast iron pans, and has a girder provided so as to pass between a plurality of rails laid on the ceiling of the building, and the girder moves on the rails via wheels. By doing so, the entire crane is configured to move.

The ladle crane is provided with a hook that can be raised and lowered, and a cast iron pan can be hooked on the hook to be lifted and moved. The hook is arranged on the girder via a wire, and the hook can be raised and lowered by winding and unwinding (lowering) the wire.
The winding and unwinding (unwinding) of the wire is performed by a main winding device provided on the girder.

  The main winding device includes an electric motor, a drum, a gear box, and the like, and the wire is wound up by winding the wire around a drum driven by the electric motor. The main winding device is installed in a trolley provided so as to be movable in a direction in which the girder is passed between the rails (hereinafter referred to as “girder width direction”). It is configured to move in the girder width direction.

  As for control of a conventional electric motor of a ladle crane, for example, Patent Document 1 discloses one using secondary resistance control. The concept of motor control using secondary resistance control is shown in FIG. In a conventional ladle crane using such secondary resistance control, a high-voltage wound AC motor is adopted as the motor of the main winding device, and a primary voltage reactor control device and a secondary resistance control device are used to control this. Was used in combination with the motor speed control.

JP-A-8-163842

  However, since the conventional ladle crane is a motor control device that controls the motor by using both the primary voltage control device and the secondary resistance control device as described above, the configuration is complicated. In addition, the configuration of the wound AC motor itself is equipped with external resistors, contactors, etc. in addition to the main body winding, and the system combining the motor and the motor control device has been improved from the standpoint of a large number of parts and reliability. There was a request. In addition, such a complicated configuration has to be expensive.

  One of the reasons for the complicated configuration as described above is a special environment in which the motor control device is arranged on a crane (girder) and the crane moves. That is, it is considered that the installation space is limited and that it must be able to withstand the large vibration unique to the mobile machine, and it has not been possible to obtain another configuration that satisfies this in the past.

  Then, in view of the said problem, this invention makes it a subject to provide an overhead crane provided with the electric motor control apparatus which is simply arrange | positioned and is appropriately arrange | positioned on a crane.

  The present invention will be described below. Here, for ease of understanding, reference numerals in the drawings are described in parentheses, but the present invention is not limited thereto.

The invention according to claim 1 is provided with a girder (20), a main winding device (40) provided on the girder, and a main winding device via wires (32, 32). An electric motor control device (50) provided with a hook (33, 33) that can be moved up and down by winding and rewinding the wire, and installed on the girder to control the speed of winding or rewinding of the wire by the main winding device The motor control device includes a high-voltage inverter (51, 51), the speed control is performed by the high-voltage inverter, and the motor control device is within the range of the center 1/3 with respect to the full width of the girder. The above-mentioned problem is solved by providing an overhead crane (10) that is installed in
Here, the high voltage inverter refers to an inverter used at 600 V or higher. The width of the girder means the size of the handed direction in which the girder is placed between the rails.

The invention according to claim 2 is the overhead crane (10) according to claim 1, wherein the high-voltage inverter is a (51, 51) matrix converter.
Since the matrix converter has a simple structure and can be reduced in size, it is suitable for application to an environment of an overhead crane with a limited installation space.

According to a third aspect of the present invention, in the overhead crane according to the first or second aspect, a plurality of electric motor control devices are provided.
According to a fourth aspect of the present invention, in the overhead crane according to any one of the first to third aspects, the main winding device is provided with a squirrel-cage induction motor.

  ADVANTAGE OF THE INVENTION According to this invention, an overhead crane provided with the electric motor control apparatus with a simple structure and appropriately arrange | positioned on a crane can be provided. Moreover, such an overhead crane has an energy saving effect.

It is a figure explaining the concept of the overhead crane which concerns on one embodiment. It is a conceptual diagram for demonstrating an electric motor control apparatus and a main winding apparatus. It is a conceptual diagram for demonstrating the other example of an electric motor control apparatus and a main winding apparatus. It is a figure which shows the vibration measurement location in an Example. It is a figure showing the chart of vibration in an example. It is a figure for demonstrating the motor control apparatus and main winding apparatus of the conventional ladle crane.

  The above-mentioned operation and gain of the present invention will be clarified from the following embodiments for carrying out the invention. Hereinafter, the present invention will be described based on embodiments shown in the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a diagram schematically illustrating a configuration of a ladle crane 10 according to one embodiment. The ladle crane 10 includes a girder 20 and wheels 21 and 21 arranged at both ends of the girder 20. As can be seen from FIG. 1, the wheels 21, 21 are arranged corresponding to each of the plurality of rails 11, 11 laid in the building, and the girder 20 is installed so as to pass between the rails 11, 11. As a result, the ladle crane 10 can move along the rails 11 and 11 in the back / front direction of FIG.

Moreover, the trolley 30 is installed in the girder 20, and this trolley 30 is comprised so that it can move to the direction orthogonal to the moving direction of the girder 20, which is the direction shown by A in FIG. Yes. A main winding device 40 is disposed on the trolley 30, and the main winding device 40 includes wires 32 and 32 and hooks 33 and 33. Therefore, the hooks 33 and 33 can be moved up and down in the direction indicated by B in FIG. 1 by winding and rewinding the wires 32 and 32 by the main winding device 40. Then, the winding and rewinding of the main winding device 40 and the speed control thereof are performed by an electric motor control device 50 provided on the girder 20.
Hereinafter, the main winding device 40 and the motor control device 50 will be described in detail. FIG. 2 schematically shows configurations and relationships of the main winding device 40 and the motor control device 50.

The main winding device 40 includes electric motors 41 and 41, a gear box 42, a drum 43, and a pulse generator (PG) 44.
The electric motors 41 and 41 are so-called three-phase induction motors, and among them, a squirrel-cage induction motor is preferable. This is because the squirrel-cage induction motor can be reduced in cost because of its simple structure, and is robust and highly reliable. Conventionally, it could hardly be used for an electric motor of a large crane such as a ladle crane from the viewpoint of speed control. However, as described below, the high-voltage inverter, particularly matrix converters 51 and 51 (see FIG. 2) are used as the motor control device 50 of the present embodiment to control the large-sized crane to compensate for the disadvantages. Can now be used. However, the present invention is not limited to this type of electric motor, and a conventional winding induction motor may be used. The squirrel-cage induction motor has been described as a preferred form from the viewpoint of a simpler configuration and improved reliability.

The gear box 42 is a device that converts the rotation of the electric motors 41 and 41 into rotation suitable for winding and rewinding and transmits the rotation to the drum 43, and includes a gear train. A known gear box 42 can be used.
The pulse generator 44 is connected to the gear box 42, and is configured to detect the rotation speed of the gear box 42 by the pulse generator 44 and feed back this to the motor control device 50 to control the rotation speed. . In addition, it is good also as a structure which connects pulse generators 44 'and 44' to each electric motor 41 and 41 and controls rotation speed like FIG.

  The drum 43 is a device that is rotated by the rotational force from the electric motors 41 and 41 transmitted through the gear box 42 and can wind up the wires 32 and 32 by winding the wires 32 and 32 around the outer periphery. . Rewinding can be performed by sequentially detaching the wires 32 and 32 from the drum 43. As the drum 43, a normal drum can be used.

  On the other hand, the electric motor control device 50 is connected to the electric motors 41 and 41, and is a device that performs rotation control of the electric motor such as control at the time of starting the electric motors 41 and 41 and speed control at the time of winding and rewinding. The motor control device 50 includes various switches, a control board, and the like, but includes matrix converters 51 and 51 in addition thereto.

The matrix converters 51 and 51 are power conversion devices that can directly output an AC voltage from an AC power source. Specifically, a circuit configured by PWM control of a bidirectional switch is provided. As a result, the structure can be simplified as compared with the conventional primary voltage control and secondary resistance control, and it is possible to reduce the size, extend the life of the device, reduce the conduction loss, and the like.
By using the matrix converters 51 and 51, the speed control of the squirrel-cage induction motor can be easily performed, and the configuration of the hoisting device 40 and, consequently, the configuration of the overhead crane can be synergistically simplified. It has become possible.

  In addition, if it controls using the matrix converter provided with the regeneration function, it will become possible to make a power regeneration area | region between the rewinding operations of an overhead crane which was difficult by the conventional secondary resistance control. Thereby, although it changes with conditions, such as a magnitude | size of a crane and a use frequency, a big power saving effect, ie, the emission amount reduction of greenhouse gas, can be performed.

  If the motor control device 50 is too large, the degree of freedom of installation on the girder 20 is reduced, so that the motor control device 50 is preferably as compact as possible.

  The motor control device 50 is preferably arranged so that the acceleration of vibration applied to the motor control device 50 when the girder 20 is moving is 1 G or less. Thereby, the electric motor control apparatus 50 is appropriately protected from vibration during crane operation.

  More preferably, as shown in FIG. 1, the motor control device 50 has a center (1 / thickness) with respect to the width L of the girder 20 (the size in the direction in which the girder 20 passes the rails 11, 11) L. 3) It is arranged within the range of L. Conventionally, large overhead cranes were thought to have very large vibrations. However, as shown in the examples below, the crane's center vibration is relatively small and the maximum acceleration is not expected. 1G or less can be secured, and by installing the motor control device 50 at this position, it can be protected from vibration.

  Moreover, the electric motor control apparatus 50 may be arrange | positioned at the girder 20 through vibration-resistant means, such as damping rubber. However, as described above, when installing in the range of (1/3) L in the center in the width direction, it is not necessary to use a special vibration-resistant means, and the equipment can be simplified. However, this does not preclude the provision of vibration-resistant means.

  Further, in the present embodiment, only one motor control device is provided, but the present invention is not necessarily limited to this, and two or more motor control devices may be provided. At this time, both electric motor control devices can be used at the same time so as to reduce the load per one. Alternatively, the specification may be such that the crane can be operated independently, and the crane can be operated on the other side even if a malfunction occurs on one side for some reason.

  With the construction of the overhead crane as described above, the overhead crane can be provided with an electric motor control device that has a simple structure and is appropriately disposed on the crane. Hereinafter, the embodiment will be described in more detail. However, the present invention is not limited to the examples.

  In this example, the vibration received by the motor control device when the girder was moved was measured. The position of the motor control device was changed and the measurement was performed for each. Specifically, the measurement was made at each of the three arrangement positions (P1, P2, P3) shown in FIG. As can be seen from FIG. 4, P <b> 1 was installed within the range of the center (1/3) W with respect to the width W of the girder (e <b> 1). On the other hand, P2 is a position slightly deviated from the center (1/3) W, and P3 is an end position in the width direction of the girder.

  For measurement of vibration, an XYZ three-direction piezoelectric acceleration sensor (model PV-93, Rion Co., Ltd.) was installed on the floor of the girder, and data on operations such as hoisting and rewinding were acquired while the crane was running. Three sensors were installed at each of the positions P1, P2, and P3. Specifically, sensors P11, P12, and P13 for position P1, P21, P22, and P23 for position P2, and sensors P31, P32, and P33 for position P3.

  FIG. 5 is a chart output result of each sensor regarding the vibration state, and t on the horizontal axis is 1 hour. Table 1 shows the maximum acceleration values obtained within a predetermined time in each sensor.

  As can be seen from FIG. 5 and Table 1, vibrations are large at the positions P2 and P3, and the acceleration may exceed 1G. On the other hand, at P1, the acceleration can be maintained at 1G or less. From the viewpoint of vibration, it can be seen that it is preferable that the position of the electric motor control device be within the range of the center (1/3) W with respect to the full width W of the girder.

  Although the present invention has been described in connection with the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein, but is claimed. The overhead crane can be changed as appropriate without departing from the scope or spirit of the invention that can be read from the scope of the present invention and the entire specification, and an overhead crane accompanying such a change must also be understood as being included in the technical scope of the present invention. Don't be.

10 Ladle crane (overhead crane)
11 rail 20 girder 21 wheel 30 trolley 32 wire 33 hook 40 main winding device 41 electric motor 42 gear box 43 drum 44 pulse generator 50 electric motor control device 51 high voltage inverter (matrix converter)

Claims (4)

A girder, and a main winding device provided in the girder;
A hook provided to the main winding device via a wire and capable of moving up and down by winding and unwinding the wire to the main winding device;
An electric motor control device that is installed in the girder and controls the speed of winding or unwinding of the wire by the main winding device;
The motor control device includes a high-voltage inverter, and the speed control is performed by the high-voltage inverter, and the motor control device is installed within a range of a central 1/3 with respect to the full width of the girder. An overhead crane characterized by.   The overhead crane according to claim 1, wherein the high-voltage inverter is a matrix converter. Overhead crane according to claim 1 or 2, wherein the motor control device is provided with a plurality. The overhead crane according to any one of claims 1 to 3, wherein the main winding device includes a squirrel-cage induction motor.